Osteoporosis(OP)is a prevalent metabolic bone disease.While drug therapy is essential to prevent bone loss in osteoporotic patients,current treatments are limited by side effects and high costs,necessitating the devel...Osteoporosis(OP)is a prevalent metabolic bone disease.While drug therapy is essential to prevent bone loss in osteoporotic patients,current treatments are limited by side effects and high costs,necessitating the development of more effective and safer targeted therapies.Utilizing a zebrafish(Danio rerio)larval model of osteoporosis,we explored the influence of the metabolite spermine on bone homeostasis.Results showed that spermine exhibited dual activity in osteoporotic zebrafish larvae by increasing bone formation and decreasing bone resorption.Spermine not only demonstrated excellent biosafety but also mitigated prednisolone-induced embryonic neurotoxicity and cardiotoxicity.Notably,spermine showcased protective attributes in the nervous systems of both zebrafish embryos and larvae.At the molecular level,Rac1 was identified as playing a pivotal role in mediating the antiosteoporotic effects of spermine,with P53 potentially acting downstream of Rac1.These findings were confirmed using mouse(Mus musculus)models,in which spermine not only ameliorated osteoporosis but also promoted bone formation and mineralization under healthy conditions,suggesting strong potential as a bonestrengthening agent.This study underscores the beneficial role of spermine in osteoporotic bone homeostasis and skeletal system development,highlighting pivotal molecular mediators.Given their efficacy and safety,human endogenous metabolites like spermine are promising candidates for new anti-osteoporotic drug development and daily bone-fortifying agents.展开更多
The retina of zebrafish can regenerate completely after injury.M ultiple studies have demonstrated that metabolic alte rations occur during retinal damage;however to date no study has identified a link between metabol...The retina of zebrafish can regenerate completely after injury.M ultiple studies have demonstrated that metabolic alte rations occur during retinal damage;however to date no study has identified a link between metabolites and retinal regeneration of zebrafish.Here,we performed an unbiased metabolome sequencing in the N-methyl-D-aspartic acid-damaged retinas of zebrafish to demonstrate the metabolomic mechanism of retinal regeneration.Among the differentially-ex pressed metabolites,we found a significant decrease in p-aminobenzoic acid in the N-methyl-D-aspartic acid-damaged retinas of zebrafish.Then,we investigated the role of p-aminobenzoic acid in retinal regeneration in adult zebrafish.Impo rtantly,p-aminobenzoic acid activated Achaetescute complex-like 1a expression,thereby promoting Müller glia reprogramming and division,as well as Müller glia-derived progenitor cell proliferation.Finally,we eliminated folic acid and inflammation as downstream effectors of PABA and demonstrated that PABA had little effect on Müller glia distribution.Taken together,these findings show that PABA contributes to retinal regeneration through activation of Achaetescute complex-like 1a expression in the N-methyl-Daspartic acid-damaged retinas of zebrafish.展开更多
[Objectives]Using wild-type AB strain of zebrafish as experimental animal,this study investigated the damaging effect of Wufang Babu Ointment on skin cells,in order to evaluate the skin toxicity of Wufang Babu Ointmen...[Objectives]Using wild-type AB strain of zebrafish as experimental animal,this study investigated the damaging effect of Wufang Babu Ointment on skin cells,in order to evaluate the skin toxicity of Wufang Babu Ointment.[Methods]Wild-type AB strain of zebrafish with an age of 2 d were taken and fed in different concentrations of Wufang Babu Ointment solution for 24 h.The number of deaths in each group of zebrafish was recorded,and the mortality rate was calculated.Using Origin 8.0 software,the maximum non lethal concentration(MNLC)was simulated.Zebrafish raised in different concentrations of Wufang Babu Ointment solution for 24 h were placed under an anatomical microscope for taking photos,to analyze and calculate the incidence of skin damage in zebrafish.Based on the statistical analysis results of this indicator,the skin toxicity of Wufang Babu Ointment was evaluated.[Results]The MNLC of Wufang Babu Ointment on zebrafish was 671μg/mL;Wufang Babu Ointment can induce skin damage at the concentrations of 224μg/mL(1/3 MNLC)and 671μg/mL(MNLC).[Conclusions]Wufang Babu Ointment had certain skin toxicity to zebrafish.展开更多
Stearyl coenzyme A desaturase(SCD), also known as delta-9 desaturase, catalyzes the rate-limiting step in the formation of monounsaturated fatty acids.In mammals, depletion or inhibition of SCD activity generally lead...Stearyl coenzyme A desaturase(SCD), also known as delta-9 desaturase, catalyzes the rate-limiting step in the formation of monounsaturated fatty acids.In mammals, depletion or inhibition of SCD activity generally leads to a decrease in triglycerides and cholesteryl esters. However, the endogenous role of scd in teleost fish remains unknown. Here, we generated a zebrafish scd mutant(scd-/-) to elucidate the role of scd in lipid metabolism and sexual development. Gas chromatography-mass spectrometry(GC-MS) showed that the scd-/- mutants had increased levels of saturated fatty acids C16:0 and C18:0, and decreased levels of monounsaturated fatty acids C16:1 and C18:1. The mutant fish displayed a short stature and an enlarged abdomen during development. Unlike Scd-/ -mammals, the scd-/- zebrafish showed significantly increased fat accumulation in the whole body,especially in the liver, leading to hepatic mitochondrial dysfunction and severe cell apoptosis.Mechanistically, srebf1, a gene encoding a transcriptional activator related to adipogenesis,acc1 and acaca, genes involved in fatty acid synthesis, and dgat2, a key gene involved in triglyceride synthesis, were significantly upregulated in mutant livers to activate fatty acid biosynthesis and adipogenesis. The scd-/- males exhibited defective natural mating behavior due to defective genital papillae but possessed functional mature sperm. All defects in the scd-/- mutants could be rescued by ubiquitous transgenic overexpression of scd. In conclusion, our study demonstrates that scd is indispensable for maintaining lipid homeostasis and development of secondary sexual characteristics in zebrafish.展开更多
Temperature tolerance restricts the distribution of a species. However, the molecular and cellular mechanisms that set the thermal tolerance limits of an organism are poorly understood. Here, we report on the function...Temperature tolerance restricts the distribution of a species. However, the molecular and cellular mechanisms that set the thermal tolerance limits of an organism are poorly understood. Here, we report on the function of dual-specificity phosphatase 1(DUSP1) in thermal tolerance regulation. Notably, we found that dusp1-/- zebrafish grew normally but survived within a narrowed temperature range. The higher susceptibility of these mutant fish to both cold and heat challenges was attributed to accelerated cell death caused by aggravated mitochondrial dysfunction and over-production of reactive oxygen species in the gills. The DUSP1-MAPK-DRP1 axis was identified as a key pathway regulating these processes in both fish and human cells. These observations suggest that DUSP1 may play a role in maintaining mitochondrial integrity and redox homeostasis. We therefore propose that maintenance of cellular redox homeostasis may be a key mechanism for coping with cellular thermal stress and that the interplay between signaling pathways regulating redox homeostasis in the most thermosensitive tissue(i.e., gills) may play an important role in setting the thermal tolerance limit of zebrafish.展开更多
Axonal regeneration in the central nervous system is an energy-intensive process.In contrast to mammals,adult zebrafish can functionally recover from neuronal injury.This raises the question of how zebrafish can cope ...Axonal regeneration in the central nervous system is an energy-intensive process.In contrast to mammals,adult zebrafish can functionally recover from neuronal injury.This raises the question of how zebrafish can cope with this high energy demand.We previously showed that in adult zebrafish,subjected to an optic nerve crush,an antagonistic axon-dendrite interplay exists wherein the retraction of retinal ganglion cell dendrites is a prerequisite for effective axonal repair.We postulate a‘dendrites for regeneration’paradigm that might be linked to intraneuronal mitochondrial reshuffling,as ganglion cells likely have insufficient resources to maintain dendrites and restore axons simultaneously.Here,we characterized both mitochondrial distribution and mitochondrial dynamics within the different ganglion cell compartments(dendrites,somas,and axons)during the regenerative process.Optic nerve crush resulted in a reduction of mitochondria in the dendrites during dendritic retraction,whereafter enlarged mitochondria appeared in the optic nerve/tract during axonal regrowth.Upon dendritic regrowth in the retina,mitochondrial density inside the retinal dendrites returned to baseline levels.Moreover,a transient increase in mitochondrial fission and biogenesis was observed in retinal ganglion cell somas after optic nerve damage.Taken together,these findings suggest that during optic nerve injury-induced regeneration,mitochondria shift from the dendrites to the axons and back again and that temporary changes in mitochondrial dynamics support axonal and dendritic regrowth after optic nerve crush.展开更多
Axon regeneration of central neurons is a complex process that is tightly regulated by multiple extrinsic and intrinsic factors.The expression levels of distinct genes are changed after central neural system(CNS)injur...Axon regeneration of central neurons is a complex process that is tightly regulated by multiple extrinsic and intrinsic factors.The expression levels of distinct genes are changed after central neural system(CNS)injury and affect axon regeneration.A previous study identified dusp2 as an upregulated gene in zebrafish with spinal cord injury.Here,we found that dual specificity phosphatase 2(DUSP2)is a negative regulator of axon regeneration of the Mauthner cell(M-cell).DUSP2 is a phosphatase that mediates the dephosphorylation of JNK.In this study,we knocked out dusp2 by CRISPR/Cas9 and found that M-cell axons of dusp2(-/-)zebrafish had a better regeneration at the early stage after birth(within 8 days after birth),while those of dusp2^(+/-)zebrafish did not.Overexpression of DUSP2 in Tg(Tol 056)zebrafish by single-cell electroporation retarded the regeneration of M-cell axons.Western blotting results showed that DUSP2 knockout slightly increased the levels of phosphorylated JNK.These findings suggest that knocking out DUSP2 promoted the regeneration of zebrafish M-cell axons,possibly through enhancing JNK phosphorylation.展开更多
The transcription factor Sox11 plays important roles in retinal neurogenesis during vertebrate eye development.However,its function in retina regeneration remains elusive.Here we report that Sox11 b,a zebrafish Sox11 ...The transcription factor Sox11 plays important roles in retinal neurogenesis during vertebrate eye development.However,its function in retina regeneration remains elusive.Here we report that Sox11 b,a zebrafish Sox11 homolog,regulates the migration and fate determination of Müller glia-derived progenitors(MGPCs)in an adult zebrafish model of mechanical retinal injury.Following a stab injury,the expression of Sox11 b was induced in proliferating MGPCs in the retina.Sox11 b knockdown did not affect MGPC formation at 4 days post-injury,although the nuclear morphology and subsequent radial migration of MGPCs were alte red.At 7 days post-injury,Sox11 b knockdown res ulted in an increased proportion of MGPCs in the inner retina and a decreased propo rtion of MGPCs in the outer nuclear layer,compared with controls.Furthermore,Sox11 b knockdown led to reduced photoreceptor regeneration,while it increased the numbe rs of newborn amacrines and retinal ganglion cells.Finally,quantitative polymerase chain reaction analysis revealed that Sox11 b regulated the expression of Notch signaling components in the retina,and Notch inhibition partially recapitulated the Sox11 b knockdown phenotype,indicating that Notch signaling functions downstream of Sox11 b.Our findings imply that Sox11 b plays key roles in MGPC migration and fate determination during retina regeneration in zebrafish,which may have critical im plications for future explorations of retinal repair in mammals.展开更多
Background: The prevalence of Parkinson’s disease (PD), a chronic and progressive neurodegenerative disorder, is projected to increase twofold by 2030. Leucine-rich repeat kinase 2 (LRRK2) is the most commonly observ...Background: The prevalence of Parkinson’s disease (PD), a chronic and progressive neurodegenerative disorder, is projected to increase twofold by 2030. Leucine-rich repeat kinase 2 (LRRK2) is the most commonly observed gene in both familial and sporadic PD cases. Notably, there is a substantial augmentation in motor activity during both larval and adult stages of zebrafish lacking the lrrk2 gene. Nevertheless, the precise genetic abnormalities accountable for eliciting these phenotypes in zebrafish are yet to be elucidated. Methods: Real-time polymerase chain reaction (PCR) was conducted on zebrafish larvae at 6 days post fertilization (dpf) belonging to both the wild-type and lrk2(-/-) groups. Guide RNA was designed and subsequently employed in the PCR process. Electrophoresis was performed to facilitate identification. Results: The expression of CNTF mRNA was significantly diminished in lrrk2(-/-), in comparison to the wildtype zebrafish larvae. This finding implies that CNTF may have crucial implications in the regulated functioning of lrrk2, which is widely acknowledged as the predominant genetic factor contributing to hereditary PD. The primers for CNTF DNA were meticulously designed, and the electrophoresis results of the PCR product were subsequently presented. The wild type zebrafish embryos were meticulously prepared for micro-injection, and the resulting efficiency identification displayed the presence of the mutant PCR product, which exhibited the presence of several debris. Conclusions: The present study demonstrates the successful generation of CNTF mutant zebrafish using the CRISPR/Cas9 genome editing technique. Further investigations are necessary to deepen our understanding of the exogenous CNTF gene’s functionality.展开更多
[Objectives]To study the effect of Huanglian Jiedu Decoction on the behavior of zebrafish with Alzheimer's disease caused by AlCl 3.[Methods]Each portion of Huanglian Jiedu Decoction was prepared according to the ...[Objectives]To study the effect of Huanglian Jiedu Decoction on the behavior of zebrafish with Alzheimer's disease caused by AlCl 3.[Methods]Each portion of Huanglian Jiedu Decoction was prepared according to the proportion of Coptis chinensis∶Phellodendron chinense Rupr.∶Scutellaria baicalensis Georgi∶Gardenia jasminoides Ellis=63 g∶42 g∶42 g∶63 g.After that,each portion of Huanglian Jiedu Decoction was soaked in 6.3 L water for 30 min and boiled twice at 100℃.The extracts were combined twice and filtered,then concentrated to 308 g/L and put into refrigerator for later use.Before training,zebrafishes were put into T-maze to adapt for 2 d,and then behavioral training was carried out for 7 d.After video recording,the behavior of zebrafish was analyzed by Smart 3.0,and qualified zebrafishes were selected for follow-up experiments.Then 60 successfully trained zebrafishes were randomly divided into control group,model group,positive group,low-dose group,medium-dose group and high-dose group of Huanglian Jiedu Decoction.Except for the control group,all the other groups were exposed to 100μg/L AlCl 3 for 7 d.After that,video was recorded,and behavioral analysis was carried out with behavioral record and analysis software Smart 3.0.And then the zebrafishes in the other four groups except the model group were treated with Huperzine A(4μg/L)and Huanglian Jiedu Decoction(154,308,616 mg/L)for 6 d,respectively.After that,it was recorded and the behavior of each group was analyzed.[Results]There was a significant difference in the time spent in the left area and the percentage of time in the left area between the control group and the model group(P<0.001).The time spent in the left area and the percentage of time in the left area in the model group and positive group,low,medium and high dose groups of Huanglian Jiedu Decoction decreased significantly(P<0.05,P<0.01,P<0.001).The swimming distance in the left area and the percentage of swimming distance in the left area in the model group were significantly higher than those in the control group(P<0.001).There was a significant difference in swimming distance between model group and positive group,low,medium and high dose groups of Huanglian Jiedu Decoction(P<0.01,P<0.001).In the percentage of swimming distance in the left area,there was a significant difference between the model group and the low and high dose groups of Huanglian Jiedu Decoction(P<0.01,P<0.001).[Conclusions]Huanglian Jiedu Decoction can improve the behavior of zebrafish with Alzheimer's disease.展开更多
AIM To evaluate the effects of chronic exposure to ethanol in the liver and the expression of inflammatory genesin zebrafish.METHODS Zebrafish(n = 104),wild type,adult,male and female,were divided into two groups:Cont...AIM To evaluate the effects of chronic exposure to ethanol in the liver and the expression of inflammatory genesin zebrafish.METHODS Zebrafish(n = 104),wild type,adult,male and female,were divided into two groups:Control and ethanol(0.05 v/v).The ethanol was directly added into water;tanks water were changed every two days and the ethanol replaced.The animals were fed twice a day with fish food until satiety.After two and four weeks of trial,livers were dissected,histological analysis(hematoxilineosin and Oil Red staining) and gene expression assessment of adiponectin,adiponectin receptor 2(adipor2),sirtuin-1(sirt-1),tumor necrosis factor-alpha(tnf-a),interleukin-1b(il-1b) and interleukin-10(il-10) were performed.Ultrastructural evaluations were conducted at fourth week.RESULTS Exposing zebrafish to 0.5% ethanol developed intense liver steatosis after four weeks,as demonstrated by oil red staining.In ethanol-treated animals,the main ultrastructural changes were related to cytoplasmic lipid particles and droplets,increased number of rough endoplasmic reticulum cisterns and glycogen particles.Between two and four weeks,hepatic mR NA expression of il-1b,sirt-1 and adipor2 were upregulated,indicating that ethanol triggered signaling molecules which are key elements in both hepatic inflammatory and protective responses.Adiponectin was not detected in the liver of animals exposed and not exposed to ethanol,and il-10 did not show significant difference.CONCLUSION Data suggest that inflammatory signaling and ultrastructural alterations play a significant role during hepatic steatosis in zebrafish chronically exposed to ethanol.展开更多
Objective:The aim of the present study was to isolate the anti-MRSA(Methicillin Resistant Staphylococcus aureus)molecule from the Mangrove symbiont Streptomyces and its biomedical studies in Zebrafish embryos.Methods:...Objective:The aim of the present study was to isolate the anti-MRSA(Methicillin Resistant Staphylococcus aureus)molecule from the Mangrove symbiont Streptomyces and its biomedical studies in Zebrafish embryos.Methods:MRSA was isolated from the pus samples of Colachal hospitals and confirmed by amplification of mecA gene.Anti-MRSA molecule producing strain was identified by!6s rRNA gene sequencing.Anti-MRSA compound production was optimized by Solid State Fermentation(SSF)and the purification of the active molecule was carried out by TLC and RP-HPLC.The inhibitory concentration and LC_(50)were calculated using Statistical software SPSS.The Biomedical studies including the cardiac assay and organ toxicity assessment were carried out in Zebraiish.Results:The bioactive anti-MRSA small molecule A,was purified by TLC with Rf value of 0.37 with 1.389 retention time at RP-HPLC.The Inhibitory Concentration of the purified molecule A_2 was 30μg/mL but,the inhibitory concentration of the MRSA in the infected embryo was 32-34μg/mL for TLC purified molecule A,with LC_(50)mean value was61.504μg/mL.Zebrafish toxicity was assessed in 48-60μg/mL by observing the physiological deformities and the heart beat rates(HBR)of embryos for anti MRSA molecule showed the mean of 41.33-41.67 HBR/15 seconds for 40μg/mL and control was 42.33-42.67 for 15 seconds which significantly showed that the anti-MRSA molecule A_2 did not affected the HBR.Conclusions:Anti-MRSA molecule from Streptomyces sp PVRK-I was isolated and biomedical studies in Zebrafish model assessed that the molecule was non toxic at the minimal inhibitory concentration of MRSA.展开更多
AIM: To investigate the impact of titanium dioxide nanoparticles(Ti O2NPs) on embryonic development and retinal neurogenesis.METHODS: The agglomeration and sedimentation of Ti O2 NPs solutions at different dilutions w...AIM: To investigate the impact of titanium dioxide nanoparticles(Ti O2NPs) on embryonic development and retinal neurogenesis.METHODS: The agglomeration and sedimentation of Ti O2 NPs solutions at different dilutions were observed,and the ultraviolet-visible spectra of their supernatants were measured. Zebrafish embryos were experimentally exposed to Ti O2 NPs until 72 h postfertilization(hpf). The retinal neurogenesis and distribution of the microglia were analyzed by immunohistochemistry and whole mount in situ hybridization.RESULTS: The 1 mg/L was determined to be an appropriate exposure dose. Embryos exposed to Ti O2 NPs had a normal phenotype. The neurogenesis was initiated on time, and ganglion cells, cones and rods were well differentiated at 72 hpf. The expression of fms m RNA and the 4C4 antibody, which were specific to microglia in the central nervous system(CNS), closely resembled their endogenous profile.CONCLUSION: These data demonstrate that short-term exposure to Ti O2 NPs at a low dose does not lead to delayed embryonic development or retinal neurotoxicity.展开更多
AIM: To establish a model of retinal neurodegeneration induced by N-Methyl-D-aspartic acid(NMDA) in adult zebrafish.METHODS: We compared the effects of three different NMDA delivery methods on retinal neurodegeneratio...AIM: To establish a model of retinal neurodegeneration induced by N-Methyl-D-aspartic acid(NMDA) in adult zebrafish.METHODS: We compared the effects of three different NMDA delivery methods on retinal neurodegeneration in adult zebrafish: immersion(I.M.), intravitreal injection(I.V.), and intraperitoneal injection(I.P.), and examined retinal pathology and degeneration by hematoxylin and eosin and TUNEL staining in the treated zebrafish. Effects of the NMDA receptor antagonist MK-801 and the natural product resveratrol on NMDA-induced retinal neurodegeneration were also assessed.RESULTS: The thickened inner retina was seen in histology with 100 μmol/L NMDA by I.M. administration. Significant apoptosis in the retinal ganglion cell layer and retinal thickness reduction occurred in 0.5 mol/L NMDA I.P. administration group.Seizure-like behavioral changes, but no retinal histological alteration occurred in 16 mg/kg NMDA I.P. administration group. Resveratrol and MK-801 prevented NMDA-induced retinal neurodegeneration in the zebrafish. CONCLUSION: Among the three drug administration methods, I.V. injection of NMDA is the most suitable for establishment of an acute retinal damage model inzebrafish. I.M. with NMDA is likely the best for use as a chronic retinal damage model. I.P. treatment with NMDA causes brain damage. Resveratrol and MK801 may be a clinically valuable treatment for retinal neurodegeneration.展开更多
AIM: To investigate the role of tumor necrosis factoralpha(TNF-α) in zebrafish retinal development and myelination.METHODS: Morpholino oligonucleotides(MO), which are complementary to the translation start site of th...AIM: To investigate the role of tumor necrosis factoralpha(TNF-α) in zebrafish retinal development and myelination.METHODS: Morpholino oligonucleotides(MO), which are complementary to the translation start site of the wild-type embryonic zebrafish TNF-α m RNA sequence,were synthesized and injected into one- to four-cell embryos. The translation blocking specificity was verified by Western blotting using an anti-TNF-α antibody,whole-mount in situ hybridization using a hepatocyte-specific m RNA probe ceruloplasmin(cp), and co-injection of TNF-α MO and TNF-α m RNA. An atonal homolog 7(atoh7) m RNA probe was used to detect neurogenesis onset. The retinal neurodifferentiation was analyzed by immunohistochemistry using antibodies Zn12, Zpr1, and Zpr3 to label ganglion cells, cones, and rods, respectively. Myelin basic protein(mbp) was used as a marker to track and observe the myelination using whole-mount in situ hybridization.RESULTS: Targeted knockdown of TNF-α resulted in specific suppression of TNF-α expression and a severely underdeveloped liver. The co-injection of TNF-α MO and m RNA rescued the liver development. Retinal neurogenesis in TNF-α morphants was initiated on time.The retina was fully laminated, while ganglion cells,cones, and rods were well differentiated at 72 hours post-fertilization(hpf). mbp was expressed in Schwann cells in the lateral line nerves and cranial nerves from 3days post-fertilization(dpf) as well as in oligodendrocytes linearly along the hindbrain bundles and the spinal cord from 4 dpf, which closely resembled its endogenous profile.CONCLUSION: TNF-α is not an essential regulator for retinal neurogenesis and optic myelination.展开更多
A potential treatment for retinal diseases is to induce an endogenous Müller glia(MG)-derived regenerative response to replace damaged neurons.In contrast to mammalian MG,zebrafish MG are capable of mediating spo...A potential treatment for retinal diseases is to induce an endogenous Müller glia(MG)-derived regenerative response to replace damaged neurons.In contrast to mammalian MG,zebrafish MG are capable of mediating spontaneous regeneration.We seek to define the mechanisms that enable retina regeneration in zebrafish in order to identify therapeutic targets to induce mammalian retina regeneration.We previously used pharmacological and genetic methods to inhibit gamma aminobutyric acid A(GABAA)receptors in undamaged zebrafish retinas and showed that such inhibition could induce initiation of retina regeneration,as measured by the dedifferentiation of MG and the appearance of MG-derived proliferating progenitor cells.Here,we show that inhibition of a pharmacologically distinct subset of GABAA receptors(GABAA-ρ)can also induce retina regeneration.Dual inhibition of both GABA receptor subtypes led to enhanced retina regeneration.Gene expression analyses indicate that inhibition of GABAA-ρreceptors induces a canonical retinal regenerative response.Our results support a model in which decreased levels of GABA,such as would occur after retinal cell death or damage,induce dedifferentiation of MG and the generation of proliferating progenitor cells during zebrafish retina regeneration.Animal experiments were approved by the Vanderbilt's Institutional Animal Care and Use Committee(Protocol M1800200)on January 29,2019.展开更多
Photodynamic therapy(PDT) employs accumulation of photosensitizers(PSs) in malignant tumor tissue followed by the light-induced generation of cytotoxic reactive oxygen species to kill the tumor cells. The success of P...Photodynamic therapy(PDT) employs accumulation of photosensitizers(PSs) in malignant tumor tissue followed by the light-induced generation of cytotoxic reactive oxygen species to kill the tumor cells. The success of PDT depends on optimal PS dosage that is matched with the ideal power of light. This in turn depends on PS accumulation in target tissue and light administration time and period.As theranostic nanomedicine is driven by multifunctional therapeutics that aim to achieve targeted tissue delivery and image-guided therapy, fluorescent PS nanoparticle(NP)accumulation in target tissues can be ascertained through fluorescence imaging to optimize the light dose and administration parameters. In this regard, zebrafish larvae provide a unique transparent in vivo platform to monitor fluorescent PS bio-distribution and their therapeutic efficiency. Using fluorescent PS NPs with unique aggregation-induced emission characteristics, we demonstrate for the first time the real-time visualization of polymeric NP accumulation in tumor tissue and, more importantly, the best time to conduct PDT using transgenic zebrafish larvae with inducible liver hyperplasia as an example.展开更多
Poor recovery of neuronal functions is one of the most common healthcare challenges for patients with different types of brain injuries and/or neurodegenerative diseases.Therapeutic interventions face two major challe...Poor recovery of neuronal functions is one of the most common healthcare challenges for patients with different types of brain injuries and/or neurodegenerative diseases.Therapeutic interventions face two major challenges:(1)How to generate neurons de novo to replenish the neuronal loss caused by injuries or neurodegeneration(restorative neurogenesis)and(2)How to prevent or limit the secondary tissue damage caused by long-term accumulation of glial cells,including microglia,at injury site(glial scar).In contrast to mammals,zebrafish have extensive regenerative capacity in numerous vital organs,including the brain,thus making them a valuable model to improve the existing therapeutic approaches for human brain repair.In response to injuries to the central nervous system(CNS),zebrafish have developed specific mechanisms to promote the recovery of the lost tissue architecture and functionality of the damaged CNS.These mechanisms include the activation of a restorative neurogenic program in a specific set of glial cells(ependymoglia)and the resolution of both the glial scar and inflammation,thus enabling proper neuronal specification and survival.In this review,we discuss the cellular and molecular mechanisms underlying the regenerative ability in the adult zebrafish brain and conclude with the potential applicability of these mechanisms in repair of the mammalian CNS.展开更多
Background: The zebrafish(Danio rerio) has recently been shown to be an ideal model to study bone disease including osteoporosis. The zebrafish osteoporosis model could be induced by glucocorticoid treatment with chem...Background: The zebrafish(Danio rerio) has recently been shown to be an ideal model to study bone disease including osteoporosis. The zebrafish osteoporosis model could be induced by glucocorticoid treatment with chemical staining for reflecting the level of bone mineralization. However, this methodology was unstable.Here, we developed a novel methodology to directly evaluate the bone mass and density.Methods: We generated and used the bone of transgenic zebrafish Tg(ola.sp7:nlsGFP) to evaluate the bone mass and density by measuring the areal extent and the integrated optical density(IOD) of enhanced green fluorescent protein(eGFP).This methodology was further compared with the traditional chemically stained method showing the bone mineralization. Furthermore, genes related to zebrafish osteoporosis were analyzed by quantitative reverse transcription-polymerase chain reaction(qRT-PCR).Results: Our results of new methods were consistent with those from chemically stained fish, following glucocorticoid-induction or epimedium flavonoid(FE)-rescue treatments. q RT-PCR analyses on mRNA levels revealed that glucocorticoid induces osteoporosis by downregulating the expression of osteoblast-related factors osterix,osteocalcin, and osteopontin, and upregulating the expression of osteoclast-related factor tartrate-resistant acid phosphatase. In FE-rescued fish, the expression of osteogenic factors osterix, osteocalcin, and osteopontin were increased.Conclusion: Compared to the traditional chemical staining methods, the new osteoporosis model using Tg(ola.sp7:nlsGFP) is more convenient and efficient for studying osteoporosis in vivo, and especially for high-throughput anti-osteoporosis drug screening.展开更多
基金supported by the National Natural Science Foundation of China (81921002,81900970,82130027)Innovative Research Team of High-Level Local Universities in Shanghai (SHSMUZLCX20212400)+1 种基金Young Physician Innovation Team Project (QC202003)of Ninth People’s Hospital affiliated to Shanghai Jiao Tong University School of MedicineShanghai“Rising Stars of Medical Talent”Youth Development Program is also acknowledged。
文摘Osteoporosis(OP)is a prevalent metabolic bone disease.While drug therapy is essential to prevent bone loss in osteoporotic patients,current treatments are limited by side effects and high costs,necessitating the development of more effective and safer targeted therapies.Utilizing a zebrafish(Danio rerio)larval model of osteoporosis,we explored the influence of the metabolite spermine on bone homeostasis.Results showed that spermine exhibited dual activity in osteoporotic zebrafish larvae by increasing bone formation and decreasing bone resorption.Spermine not only demonstrated excellent biosafety but also mitigated prednisolone-induced embryonic neurotoxicity and cardiotoxicity.Notably,spermine showcased protective attributes in the nervous systems of both zebrafish embryos and larvae.At the molecular level,Rac1 was identified as playing a pivotal role in mediating the antiosteoporotic effects of spermine,with P53 potentially acting downstream of Rac1.These findings were confirmed using mouse(Mus musculus)models,in which spermine not only ameliorated osteoporosis but also promoted bone formation and mineralization under healthy conditions,suggesting strong potential as a bonestrengthening agent.This study underscores the beneficial role of spermine in osteoporotic bone homeostasis and skeletal system development,highlighting pivotal molecular mediators.Given their efficacy and safety,human endogenous metabolites like spermine are promising candidates for new anti-osteoporotic drug development and daily bone-fortifying agents.
基金supported by the National Natural Science Foundation of China,Nos.81974134(to XX)and 82000895(to HL)National Key Research and Development Program of China,Nos.2021YFA1101200&2021YFA1101202National Natural Science Foundation of Hunan Province,China,No.2022JJ30071(to HL)。
文摘The retina of zebrafish can regenerate completely after injury.M ultiple studies have demonstrated that metabolic alte rations occur during retinal damage;however to date no study has identified a link between metabolites and retinal regeneration of zebrafish.Here,we performed an unbiased metabolome sequencing in the N-methyl-D-aspartic acid-damaged retinas of zebrafish to demonstrate the metabolomic mechanism of retinal regeneration.Among the differentially-ex pressed metabolites,we found a significant decrease in p-aminobenzoic acid in the N-methyl-D-aspartic acid-damaged retinas of zebrafish.Then,we investigated the role of p-aminobenzoic acid in retinal regeneration in adult zebrafish.Impo rtantly,p-aminobenzoic acid activated Achaetescute complex-like 1a expression,thereby promoting Müller glia reprogramming and division,as well as Müller glia-derived progenitor cell proliferation.Finally,we eliminated folic acid and inflammation as downstream effectors of PABA and demonstrated that PABA had little effect on Müller glia distribution.Taken together,these findings show that PABA contributes to retinal regeneration through activation of Achaetescute complex-like 1a expression in the N-methyl-Daspartic acid-damaged retinas of zebrafish.
基金Supported by Guangxi Key R&D Plan(GUIKE AB20297010)Guangxi Science and Technology Base and Talent Special Project(GUIKE AD23023011)the National Natural Science Foundation of China(81960889).
文摘[Objectives]Using wild-type AB strain of zebrafish as experimental animal,this study investigated the damaging effect of Wufang Babu Ointment on skin cells,in order to evaluate the skin toxicity of Wufang Babu Ointment.[Methods]Wild-type AB strain of zebrafish with an age of 2 d were taken and fed in different concentrations of Wufang Babu Ointment solution for 24 h.The number of deaths in each group of zebrafish was recorded,and the mortality rate was calculated.Using Origin 8.0 software,the maximum non lethal concentration(MNLC)was simulated.Zebrafish raised in different concentrations of Wufang Babu Ointment solution for 24 h were placed under an anatomical microscope for taking photos,to analyze and calculate the incidence of skin damage in zebrafish.Based on the statistical analysis results of this indicator,the skin toxicity of Wufang Babu Ointment was evaluated.[Results]The MNLC of Wufang Babu Ointment on zebrafish was 671μg/mL;Wufang Babu Ointment can induce skin damage at the concentrations of 224μg/mL(1/3 MNLC)and 671μg/mL(MNLC).[Conclusions]Wufang Babu Ointment had certain skin toxicity to zebrafish.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA24010108)National Natural Science Foundation of China(31872554,32172952)Project from the State Key Laboratory of Freshwater Ecology and Biotechnology(2019FBZ05)。
文摘Stearyl coenzyme A desaturase(SCD), also known as delta-9 desaturase, catalyzes the rate-limiting step in the formation of monounsaturated fatty acids.In mammals, depletion or inhibition of SCD activity generally leads to a decrease in triglycerides and cholesteryl esters. However, the endogenous role of scd in teleost fish remains unknown. Here, we generated a zebrafish scd mutant(scd-/-) to elucidate the role of scd in lipid metabolism and sexual development. Gas chromatography-mass spectrometry(GC-MS) showed that the scd-/- mutants had increased levels of saturated fatty acids C16:0 and C18:0, and decreased levels of monounsaturated fatty acids C16:1 and C18:1. The mutant fish displayed a short stature and an enlarged abdomen during development. Unlike Scd-/ -mammals, the scd-/- zebrafish showed significantly increased fat accumulation in the whole body,especially in the liver, leading to hepatic mitochondrial dysfunction and severe cell apoptosis.Mechanistically, srebf1, a gene encoding a transcriptional activator related to adipogenesis,acc1 and acaca, genes involved in fatty acid synthesis, and dgat2, a key gene involved in triglyceride synthesis, were significantly upregulated in mutant livers to activate fatty acid biosynthesis and adipogenesis. The scd-/- males exhibited defective natural mating behavior due to defective genital papillae but possessed functional mature sperm. All defects in the scd-/- mutants could be rescued by ubiquitous transgenic overexpression of scd. In conclusion, our study demonstrates that scd is indispensable for maintaining lipid homeostasis and development of secondary sexual characteristics in zebrafish.
基金supported by the National Key Research and Development Program of China(2018YFD0900601)National Natural Science Foundation of China(32130109)。
文摘Temperature tolerance restricts the distribution of a species. However, the molecular and cellular mechanisms that set the thermal tolerance limits of an organism are poorly understood. Here, we report on the function of dual-specificity phosphatase 1(DUSP1) in thermal tolerance regulation. Notably, we found that dusp1-/- zebrafish grew normally but survived within a narrowed temperature range. The higher susceptibility of these mutant fish to both cold and heat challenges was attributed to accelerated cell death caused by aggravated mitochondrial dysfunction and over-production of reactive oxygen species in the gills. The DUSP1-MAPK-DRP1 axis was identified as a key pathway regulating these processes in both fish and human cells. These observations suggest that DUSP1 may play a role in maintaining mitochondrial integrity and redox homeostasis. We therefore propose that maintenance of cellular redox homeostasis may be a key mechanism for coping with cellular thermal stress and that the interplay between signaling pathways regulating redox homeostasis in the most thermosensitive tissue(i.e., gills) may play an important role in setting the thermal tolerance limit of zebrafish.
基金financially supported by the Katholieke Universiteit Leuven Research Council (C14/18/053)the research foundation Flanders (FWO) (G082221N)+1 种基金a personal L’Oréal/UNESCO (For Women in Science) fellowshipa personal FWO fellowship
文摘Axonal regeneration in the central nervous system is an energy-intensive process.In contrast to mammals,adult zebrafish can functionally recover from neuronal injury.This raises the question of how zebrafish can cope with this high energy demand.We previously showed that in adult zebrafish,subjected to an optic nerve crush,an antagonistic axon-dendrite interplay exists wherein the retraction of retinal ganglion cell dendrites is a prerequisite for effective axonal repair.We postulate a‘dendrites for regeneration’paradigm that might be linked to intraneuronal mitochondrial reshuffling,as ganglion cells likely have insufficient resources to maintain dendrites and restore axons simultaneously.Here,we characterized both mitochondrial distribution and mitochondrial dynamics within the different ganglion cell compartments(dendrites,somas,and axons)during the regenerative process.Optic nerve crush resulted in a reduction of mitochondria in the dendrites during dendritic retraction,whereafter enlarged mitochondria appeared in the optic nerve/tract during axonal regrowth.Upon dendritic regrowth in the retina,mitochondrial density inside the retinal dendrites returned to baseline levels.Moreover,a transient increase in mitochondrial fission and biogenesis was observed in retinal ganglion cell somas after optic nerve damage.Taken together,these findings suggest that during optic nerve injury-induced regeneration,mitochondria shift from the dendrites to the axons and back again and that temporary changes in mitochondrial dynamics support axonal and dendritic regrowth after optic nerve crush.
基金granted by the National Natural Science Foundation of China,No.82071357Ministry of Science and Technology of China,No.2019YFA0405600(both to BH).
文摘Axon regeneration of central neurons is a complex process that is tightly regulated by multiple extrinsic and intrinsic factors.The expression levels of distinct genes are changed after central neural system(CNS)injury and affect axon regeneration.A previous study identified dusp2 as an upregulated gene in zebrafish with spinal cord injury.Here,we found that dual specificity phosphatase 2(DUSP2)is a negative regulator of axon regeneration of the Mauthner cell(M-cell).DUSP2 is a phosphatase that mediates the dephosphorylation of JNK.In this study,we knocked out dusp2 by CRISPR/Cas9 and found that M-cell axons of dusp2(-/-)zebrafish had a better regeneration at the early stage after birth(within 8 days after birth),while those of dusp2^(+/-)zebrafish did not.Overexpression of DUSP2 in Tg(Tol 056)zebrafish by single-cell electroporation retarded the regeneration of M-cell axons.Western blotting results showed that DUSP2 knockout slightly increased the levels of phosphorylated JNK.These findings suggest that knocking out DUSP2 promoted the regeneration of zebrafish M-cell axons,possibly through enhancing JNK phosphorylation.
基金supported by the National Key Research and Development Project of China,Nos.2017YFA0104100(to JL),2017YFA0701304(to HX)National Natural Science Foundation of China Nos.81970820(to HX),31930068(to JL)。
文摘The transcription factor Sox11 plays important roles in retinal neurogenesis during vertebrate eye development.However,its function in retina regeneration remains elusive.Here we report that Sox11 b,a zebrafish Sox11 homolog,regulates the migration and fate determination of Müller glia-derived progenitors(MGPCs)in an adult zebrafish model of mechanical retinal injury.Following a stab injury,the expression of Sox11 b was induced in proliferating MGPCs in the retina.Sox11 b knockdown did not affect MGPC formation at 4 days post-injury,although the nuclear morphology and subsequent radial migration of MGPCs were alte red.At 7 days post-injury,Sox11 b knockdown res ulted in an increased proportion of MGPCs in the inner retina and a decreased propo rtion of MGPCs in the outer nuclear layer,compared with controls.Furthermore,Sox11 b knockdown led to reduced photoreceptor regeneration,while it increased the numbe rs of newborn amacrines and retinal ganglion cells.Finally,quantitative polymerase chain reaction analysis revealed that Sox11 b regulated the expression of Notch signaling components in the retina,and Notch inhibition partially recapitulated the Sox11 b knockdown phenotype,indicating that Notch signaling functions downstream of Sox11 b.Our findings imply that Sox11 b plays key roles in MGPC migration and fate determination during retina regeneration in zebrafish,which may have critical im plications for future explorations of retinal repair in mammals.
文摘Background: The prevalence of Parkinson’s disease (PD), a chronic and progressive neurodegenerative disorder, is projected to increase twofold by 2030. Leucine-rich repeat kinase 2 (LRRK2) is the most commonly observed gene in both familial and sporadic PD cases. Notably, there is a substantial augmentation in motor activity during both larval and adult stages of zebrafish lacking the lrrk2 gene. Nevertheless, the precise genetic abnormalities accountable for eliciting these phenotypes in zebrafish are yet to be elucidated. Methods: Real-time polymerase chain reaction (PCR) was conducted on zebrafish larvae at 6 days post fertilization (dpf) belonging to both the wild-type and lrk2(-/-) groups. Guide RNA was designed and subsequently employed in the PCR process. Electrophoresis was performed to facilitate identification. Results: The expression of CNTF mRNA was significantly diminished in lrrk2(-/-), in comparison to the wildtype zebrafish larvae. This finding implies that CNTF may have crucial implications in the regulated functioning of lrrk2, which is widely acknowledged as the predominant genetic factor contributing to hereditary PD. The primers for CNTF DNA were meticulously designed, and the electrophoresis results of the PCR product were subsequently presented. The wild type zebrafish embryos were meticulously prepared for micro-injection, and the resulting efficiency identification displayed the presence of the mutant PCR product, which exhibited the presence of several debris. Conclusions: The present study demonstrates the successful generation of CNTF mutant zebrafish using the CRISPR/Cas9 genome editing technique. Further investigations are necessary to deepen our understanding of the exogenous CNTF gene’s functionality.
基金Supported by National Natural Science Foundation of China(82160832)Natural Science Foundation of Guangxi Zhuang Autonomous Region(2017GXNSFAA198255,2018GXNSFBA138028)+2 种基金the Open Project Program of Guangxi Key Laboratory of Brain and Cognitive Neuroscience,Guilin Medical University(GKLBCN-202206-02,GKLBCN-202206-05)2022 Annual Scientific Research Project of Guangdong Provincial Administration of Traditional Chinese Medicine(20222138)the Fourth Training Plan for Thousands of Young and Mid-aged Mainstay Teachers in Guangxi Colleges and Universities,and the Innovation and Entrepreneurship Training Program for College Students in Guilin Medical University in 2022(202210601214).
文摘[Objectives]To study the effect of Huanglian Jiedu Decoction on the behavior of zebrafish with Alzheimer's disease caused by AlCl 3.[Methods]Each portion of Huanglian Jiedu Decoction was prepared according to the proportion of Coptis chinensis∶Phellodendron chinense Rupr.∶Scutellaria baicalensis Georgi∶Gardenia jasminoides Ellis=63 g∶42 g∶42 g∶63 g.After that,each portion of Huanglian Jiedu Decoction was soaked in 6.3 L water for 30 min and boiled twice at 100℃.The extracts were combined twice and filtered,then concentrated to 308 g/L and put into refrigerator for later use.Before training,zebrafishes were put into T-maze to adapt for 2 d,and then behavioral training was carried out for 7 d.After video recording,the behavior of zebrafish was analyzed by Smart 3.0,and qualified zebrafishes were selected for follow-up experiments.Then 60 successfully trained zebrafishes were randomly divided into control group,model group,positive group,low-dose group,medium-dose group and high-dose group of Huanglian Jiedu Decoction.Except for the control group,all the other groups were exposed to 100μg/L AlCl 3 for 7 d.After that,video was recorded,and behavioral analysis was carried out with behavioral record and analysis software Smart 3.0.And then the zebrafishes in the other four groups except the model group were treated with Huperzine A(4μg/L)and Huanglian Jiedu Decoction(154,308,616 mg/L)for 6 d,respectively.After that,it was recorded and the behavior of each group was analyzed.[Results]There was a significant difference in the time spent in the left area and the percentage of time in the left area between the control group and the model group(P<0.001).The time spent in the left area and the percentage of time in the left area in the model group and positive group,low,medium and high dose groups of Huanglian Jiedu Decoction decreased significantly(P<0.05,P<0.01,P<0.001).The swimming distance in the left area and the percentage of swimming distance in the left area in the model group were significantly higher than those in the control group(P<0.001).There was a significant difference in swimming distance between model group and positive group,low,medium and high dose groups of Huanglian Jiedu Decoction(P<0.01,P<0.001).In the percentage of swimming distance in the left area,there was a significant difference between the model group and the low and high dose groups of Huanglian Jiedu Decoction(P<0.01,P<0.001).[Conclusions]Huanglian Jiedu Decoction can improve the behavior of zebrafish with Alzheimer's disease.
基金FIPE HCPA(Fundo de Incentivo à Pesquisa Hospital de Clínicas de Porto Alegre)CNPq(National Counsel of Technological and Scientific Development) for financial support
文摘AIM To evaluate the effects of chronic exposure to ethanol in the liver and the expression of inflammatory genesin zebrafish.METHODS Zebrafish(n = 104),wild type,adult,male and female,were divided into two groups:Control and ethanol(0.05 v/v).The ethanol was directly added into water;tanks water were changed every two days and the ethanol replaced.The animals were fed twice a day with fish food until satiety.After two and four weeks of trial,livers were dissected,histological analysis(hematoxilineosin and Oil Red staining) and gene expression assessment of adiponectin,adiponectin receptor 2(adipor2),sirtuin-1(sirt-1),tumor necrosis factor-alpha(tnf-a),interleukin-1b(il-1b) and interleukin-10(il-10) were performed.Ultrastructural evaluations were conducted at fourth week.RESULTS Exposing zebrafish to 0.5% ethanol developed intense liver steatosis after four weeks,as demonstrated by oil red staining.In ethanol-treated animals,the main ultrastructural changes were related to cytoplasmic lipid particles and droplets,increased number of rough endoplasmic reticulum cisterns and glycogen particles.Between two and four weeks,hepatic mR NA expression of il-1b,sirt-1 and adipor2 were upregulated,indicating that ethanol triggered signaling molecules which are key elements in both hepatic inflammatory and protective responses.Adiponectin was not detected in the liver of animals exposed and not exposed to ethanol,and il-10 did not show significant difference.CONCLUSION Data suggest that inflammatory signaling and ultrastructural alterations play a significant role during hepatic steatosis in zebrafish chronically exposed to ethanol.
基金Supported by Xpression Biotek Ltd.and International Centre for Nanobiotechnology(ICN).Manonmaniam Sundaranar University
文摘Objective:The aim of the present study was to isolate the anti-MRSA(Methicillin Resistant Staphylococcus aureus)molecule from the Mangrove symbiont Streptomyces and its biomedical studies in Zebrafish embryos.Methods:MRSA was isolated from the pus samples of Colachal hospitals and confirmed by amplification of mecA gene.Anti-MRSA molecule producing strain was identified by!6s rRNA gene sequencing.Anti-MRSA compound production was optimized by Solid State Fermentation(SSF)and the purification of the active molecule was carried out by TLC and RP-HPLC.The inhibitory concentration and LC_(50)were calculated using Statistical software SPSS.The Biomedical studies including the cardiac assay and organ toxicity assessment were carried out in Zebraiish.Results:The bioactive anti-MRSA small molecule A,was purified by TLC with Rf value of 0.37 with 1.389 retention time at RP-HPLC.The Inhibitory Concentration of the purified molecule A_2 was 30μg/mL but,the inhibitory concentration of the MRSA in the infected embryo was 32-34μg/mL for TLC purified molecule A,with LC_(50)mean value was61.504μg/mL.Zebrafish toxicity was assessed in 48-60μg/mL by observing the physiological deformities and the heart beat rates(HBR)of embryos for anti MRSA molecule showed the mean of 41.33-41.67 HBR/15 seconds for 40μg/mL and control was 42.33-42.67 for 15 seconds which significantly showed that the anti-MRSA molecule A_2 did not affected the HBR.Conclusions:Anti-MRSA molecule from Streptomyces sp PVRK-I was isolated and biomedical studies in Zebrafish model assessed that the molecule was non toxic at the minimal inhibitory concentration of MRSA.
基金Supported by the National Natural Science Foundation of China (No.81301080)the National Key Technology R&D Program of China (2012BAI08B06)the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry
文摘AIM: To investigate the impact of titanium dioxide nanoparticles(Ti O2NPs) on embryonic development and retinal neurogenesis.METHODS: The agglomeration and sedimentation of Ti O2 NPs solutions at different dilutions were observed,and the ultraviolet-visible spectra of their supernatants were measured. Zebrafish embryos were experimentally exposed to Ti O2 NPs until 72 h postfertilization(hpf). The retinal neurogenesis and distribution of the microglia were analyzed by immunohistochemistry and whole mount in situ hybridization.RESULTS: The 1 mg/L was determined to be an appropriate exposure dose. Embryos exposed to Ti O2 NPs had a normal phenotype. The neurogenesis was initiated on time, and ganglion cells, cones and rods were well differentiated at 72 hpf. The expression of fms m RNA and the 4C4 antibody, which were specific to microglia in the central nervous system(CNS), closely resembled their endogenous profile.CONCLUSION: These data demonstrate that short-term exposure to Ti O2 NPs at a low dose does not lead to delayed embryonic development or retinal neurotoxicity.
基金Supported by the National Natural Science Foundation of China (No.81271425 No.81260148+5 种基金 No.31400988 No.81160144 No.31171044)the Jiangxi Provincial Natural Science Foundation (No.20181ACG70010)the Natural Science Foundation of Jiangxi (No.20151BBG70243 No.20122BCB23007)
文摘AIM: To establish a model of retinal neurodegeneration induced by N-Methyl-D-aspartic acid(NMDA) in adult zebrafish.METHODS: We compared the effects of three different NMDA delivery methods on retinal neurodegeneration in adult zebrafish: immersion(I.M.), intravitreal injection(I.V.), and intraperitoneal injection(I.P.), and examined retinal pathology and degeneration by hematoxylin and eosin and TUNEL staining in the treated zebrafish. Effects of the NMDA receptor antagonist MK-801 and the natural product resveratrol on NMDA-induced retinal neurodegeneration were also assessed.RESULTS: The thickened inner retina was seen in histology with 100 μmol/L NMDA by I.M. administration. Significant apoptosis in the retinal ganglion cell layer and retinal thickness reduction occurred in 0.5 mol/L NMDA I.P. administration group.Seizure-like behavioral changes, but no retinal histological alteration occurred in 16 mg/kg NMDA I.P. administration group. Resveratrol and MK-801 prevented NMDA-induced retinal neurodegeneration in the zebrafish. CONCLUSION: Among the three drug administration methods, I.V. injection of NMDA is the most suitable for establishment of an acute retinal damage model inzebrafish. I.M. with NMDA is likely the best for use as a chronic retinal damage model. I.P. treatment with NMDA causes brain damage. Resveratrol and MK801 may be a clinically valuable treatment for retinal neurodegeneration.
基金Supported by the National Natural Science Foundation of China (No.81301080)the Tianjin Natural Science Foundation (No.15JCYBJC24400, No.15JCQNJC10900)the Scientific Research Foundation for the Returned Overseas Chinese Scholars (No.2012-1707)
文摘AIM: To investigate the role of tumor necrosis factoralpha(TNF-α) in zebrafish retinal development and myelination.METHODS: Morpholino oligonucleotides(MO), which are complementary to the translation start site of the wild-type embryonic zebrafish TNF-α m RNA sequence,were synthesized and injected into one- to four-cell embryos. The translation blocking specificity was verified by Western blotting using an anti-TNF-α antibody,whole-mount in situ hybridization using a hepatocyte-specific m RNA probe ceruloplasmin(cp), and co-injection of TNF-α MO and TNF-α m RNA. An atonal homolog 7(atoh7) m RNA probe was used to detect neurogenesis onset. The retinal neurodifferentiation was analyzed by immunohistochemistry using antibodies Zn12, Zpr1, and Zpr3 to label ganglion cells, cones, and rods, respectively. Myelin basic protein(mbp) was used as a marker to track and observe the myelination using whole-mount in situ hybridization.RESULTS: Targeted knockdown of TNF-α resulted in specific suppression of TNF-α expression and a severely underdeveloped liver. The co-injection of TNF-α MO and m RNA rescued the liver development. Retinal neurogenesis in TNF-α morphants was initiated on time.The retina was fully laminated, while ganglion cells,cones, and rods were well differentiated at 72 hours post-fertilization(hpf). mbp was expressed in Schwann cells in the lateral line nerves and cranial nerves from 3days post-fertilization(dpf) as well as in oligodendrocytes linearly along the hindbrain bundles and the spinal cord from 4 dpf, which closely resembled its endogenous profile.CONCLUSION: TNF-α is not an essential regulator for retinal neurogenesis and optic myelination.
基金grants from the NIH R01EY024354-S1 and UO1 EY027265 to JGPand T32 EY021453additional support from the Stevenson family and Gisela Mosig endowments to Vanderbilt University。
文摘A potential treatment for retinal diseases is to induce an endogenous Müller glia(MG)-derived regenerative response to replace damaged neurons.In contrast to mammalian MG,zebrafish MG are capable of mediating spontaneous regeneration.We seek to define the mechanisms that enable retina regeneration in zebrafish in order to identify therapeutic targets to induce mammalian retina regeneration.We previously used pharmacological and genetic methods to inhibit gamma aminobutyric acid A(GABAA)receptors in undamaged zebrafish retinas and showed that such inhibition could induce initiation of retina regeneration,as measured by the dedifferentiation of MG and the appearance of MG-derived proliferating progenitor cells.Here,we show that inhibition of a pharmacologically distinct subset of GABAA receptors(GABAA-ρ)can also induce retina regeneration.Dual inhibition of both GABA receptor subtypes led to enhanced retina regeneration.Gene expression analyses indicate that inhibition of GABAA-ρreceptors induces a canonical retinal regenerative response.Our results support a model in which decreased levels of GABA,such as would occur after retinal cell death or damage,induce dedifferentiation of MG and the generation of proliferating progenitor cells during zebrafish retina regeneration.Animal experiments were approved by the Vanderbilt's Institutional Animal Care and Use Committee(Protocol M1800200)on January 29,2019.
基金financial support from National Research Foundation Investigatorship (R279-000-444-281)National University of Singapore (R279-000-482-133)
文摘Photodynamic therapy(PDT) employs accumulation of photosensitizers(PSs) in malignant tumor tissue followed by the light-induced generation of cytotoxic reactive oxygen species to kill the tumor cells. The success of PDT depends on optimal PS dosage that is matched with the ideal power of light. This in turn depends on PS accumulation in target tissue and light administration time and period.As theranostic nanomedicine is driven by multifunctional therapeutics that aim to achieve targeted tissue delivery and image-guided therapy, fluorescent PS nanoparticle(NP)accumulation in target tissues can be ascertained through fluorescence imaging to optimize the light dose and administration parameters. In this regard, zebrafish larvae provide a unique transparent in vivo platform to monitor fluorescent PS bio-distribution and their therapeutic efficiency. Using fluorescent PS NPs with unique aggregation-induced emission characteristics, we demonstrate for the first time the real-time visualization of polymeric NP accumulation in tumor tissue and, more importantly, the best time to conduct PDT using transgenic zebrafish larvae with inducible liver hyperplasia as an example.
基金Supported by the German Research foundation(DFG),No.SFB 870
文摘Poor recovery of neuronal functions is one of the most common healthcare challenges for patients with different types of brain injuries and/or neurodegenerative diseases.Therapeutic interventions face two major challenges:(1)How to generate neurons de novo to replenish the neuronal loss caused by injuries or neurodegeneration(restorative neurogenesis)and(2)How to prevent or limit the secondary tissue damage caused by long-term accumulation of glial cells,including microglia,at injury site(glial scar).In contrast to mammals,zebrafish have extensive regenerative capacity in numerous vital organs,including the brain,thus making them a valuable model to improve the existing therapeutic approaches for human brain repair.In response to injuries to the central nervous system(CNS),zebrafish have developed specific mechanisms to promote the recovery of the lost tissue architecture and functionality of the damaged CNS.These mechanisms include the activation of a restorative neurogenic program in a specific set of glial cells(ependymoglia)and the resolution of both the glial scar and inflammation,thus enabling proper neuronal specification and survival.In this review,we discuss the cellular and molecular mechanisms underlying the regenerative ability in the adult zebrafish brain and conclude with the potential applicability of these mechanisms in repair of the mammalian CNS.
基金National Natural Science Foundation of China,Grant/Award Number:31771628Initial Program of Excellent Young High School Teachers,Guangdong,China,Grant/Award Number:Yue Jiaoshi Han [2016]6:YQ2015081Guangdong Natural Science Fund for Distinguished Young Scholars,Grant/Award Number:2017A030306024
文摘Background: The zebrafish(Danio rerio) has recently been shown to be an ideal model to study bone disease including osteoporosis. The zebrafish osteoporosis model could be induced by glucocorticoid treatment with chemical staining for reflecting the level of bone mineralization. However, this methodology was unstable.Here, we developed a novel methodology to directly evaluate the bone mass and density.Methods: We generated and used the bone of transgenic zebrafish Tg(ola.sp7:nlsGFP) to evaluate the bone mass and density by measuring the areal extent and the integrated optical density(IOD) of enhanced green fluorescent protein(eGFP).This methodology was further compared with the traditional chemically stained method showing the bone mineralization. Furthermore, genes related to zebrafish osteoporosis were analyzed by quantitative reverse transcription-polymerase chain reaction(qRT-PCR).Results: Our results of new methods were consistent with those from chemically stained fish, following glucocorticoid-induction or epimedium flavonoid(FE)-rescue treatments. q RT-PCR analyses on mRNA levels revealed that glucocorticoid induces osteoporosis by downregulating the expression of osteoblast-related factors osterix,osteocalcin, and osteopontin, and upregulating the expression of osteoclast-related factor tartrate-resistant acid phosphatase. In FE-rescued fish, the expression of osteogenic factors osterix, osteocalcin, and osteopontin were increased.Conclusion: Compared to the traditional chemical staining methods, the new osteoporosis model using Tg(ola.sp7:nlsGFP) is more convenient and efficient for studying osteoporosis in vivo, and especially for high-throughput anti-osteoporosis drug screening.
