Alzheimer s disease,among the most common neurodegenerative disorders,is chara cterized by progressive cognitive impairment.At present,the Alzheimer’s disease main risk remains genetic ris ks,but major environmental ...Alzheimer s disease,among the most common neurodegenerative disorders,is chara cterized by progressive cognitive impairment.At present,the Alzheimer’s disease main risk remains genetic ris ks,but major environmental fa ctors are increasingly shown to impact Alzheimer’s disease development and progression.Microglia,the most important brain immune cells,play a central role in Alzheimer’s disease pathogenesis and are considered environmental and lifestyle"sensors."Factors like environmental pollution and modern lifestyles(e.g.,chronic stress,poor dietary habits,sleep,and circadian rhythm disorde rs)can cause neuroinflammato ry responses that lead to cognitive impairment via microglial functioning and phenotypic regulation.However,the specific mechanisms underlying interactions among these facto rs and microglia in Alzheimer’s disease are unclear.Herein,we:discuss the biological effects of air pollution,chronic stress,gut micro biota,sleep patterns,physical exercise,cigarette smoking,and caffeine consumption on microglia;consider how unhealthy lifestyle factors influence individual susceptibility to Alzheimer’s disease;and present the neuroprotective effects of a healthy lifestyle.Toward intervening and controlling these environmental risk fa ctors at an early Alzheimer’s disease stage,understanding the role of microglia in Alzheimer’s disease development,and to rgeting strategies to to rget microglia,co uld be essential to future Alzheimer’s disease treatments.展开更多
Interferon regulatory factor 7 plays a crucial role in the innate immune response.However,whether interferon regulatory factor 7-mediated signaling contributes to Parkinson's disease remains unknown.Here we report...Interferon regulatory factor 7 plays a crucial role in the innate immune response.However,whether interferon regulatory factor 7-mediated signaling contributes to Parkinson's disease remains unknown.Here we report that interferon regulatory factor 7 is markedly up-regulated in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced mouse model of Parkinson's disease and co-localizes with microglial cells.Both the selective cyclic guanosine monophosphate adenosine monophosphate synthase inhibitor RU.521 and the stimulator of interferon genes inhibitor H151 effectively suppressed interferon regulatory factor 7 activation in BV2 microglia exposed to 1-methyl-4-phenylpyridinium and inhibited transformation of mouse BV2 microglia into the neurotoxic M1 phenotype.In addition,si RNA-mediated knockdown of interferon regulatory factor 7 expression in BV2 microglia reduced the expression of inducible nitric oxide synthase,tumor necrosis factorα,CD16,CD32,and CD86 and increased the expression of the anti-inflammatory markers ARG1 and YM1.Taken together,our findings indicate that the cyclic guanosine monophosphate adenosine monophosphate synthase-stimulator of interferon genes-interferon regulatory factor 7 pathway plays a crucial role in the pathogenesis of Parkinson's disease.展开更多
BACKGROUND Oncostatin M(OSM)is a pleiotropic cytokine which is implicated in the path-ogenesis of inflammatory bowel disease(IBD).AIM To evaluate the prognostic role of OSM in IBD patients.METHODS Literature search wa...BACKGROUND Oncostatin M(OSM)is a pleiotropic cytokine which is implicated in the path-ogenesis of inflammatory bowel disease(IBD).AIM To evaluate the prognostic role of OSM in IBD patients.METHODS Literature search was conducted in electronic databases(Google Scholar,Embase,PubMed,Science Direct,Springer,and Wiley).Studies were selected if they reported prognostic information about OSM in IBD patients.Outcome data were synthesized,and meta-analyses were performed to estimate standardized mean differences(SMDs)in OSM levels between treatment responders and non-res-ponders and to seek overall correlations of OSM with other inflammatory bio-markers.RESULTS Sixteen studies(818 Crohn’s disease and 686 ulcerative colitis patients treated with anti-tumor necrosis factor-based therapies)were included.OSM levels were associated with IBD severity.A meta-analysis found significantly higher OSM levels in non-responders than in responders to therapy[SMD 0.80(0.33,1.27);P=0.001],in non-remitters than in remitters[SMD 0.75(95%CI:0.35 to 1.16);P<0.0001]and in patients with no mucosal healing than in those with mucosal heal-ing[SMD 0.63(0.30,0.95);P<0.0001].Area under receiver operator curve values showed considerable variability between studies but in general higher OSM levels were associated with poor prognosis.OSM had significant correlations with Simple Endoscopic Score of Crohn’s disease[r=0.47(95%CI:0.25 to 0.64);P<0.0001],Mayo Endoscopic Score[r=0.35(95%CI:0.28 to 0.41);P<0.0001],fecal calprotectin[r=0.19(95%CI:0.08 to 0.3);P=0.001],C-reactive protein[r=0.25(95%CI:0.11 to 0.39);P<0.0001],and platelet count[r=0.28(95%CI:0.17 to 0.39);P<0.0001].CONCLUSION OSM is a potential candidate for determining the severity of disease and predicting the outcomes of anti-tumor necrosis factor-based therapies in IBD patients.展开更多
BACKGROUND Ménétrier’s disease is a rare condition characterized by enlarged gastric folds,usually located in the whole body and fundus of the stomach.This report presents an unusual case of localized M...BACKGROUND Ménétrier’s disease is a rare condition characterized by enlarged gastric folds,usually located in the whole body and fundus of the stomach.This report presents an unusual case of localized Ménétrier’s disease elevated by a submucosal lipoma and thus looking like a polypoid mass and causing an episode of upper gastrointestinal bleeding.The mass was successfully removed with endoscopic submucosal dissection.CASE SUMMARY Esophagogastroduodenoscopy was performed on a 76-year-old male patient after an episode of upper gastrointestinal bleeding,manifesting as fatigue and melena.A large polypoid mass(4 cm×1 cm)with enlarged mucosal folds was found in the body of the stomach,between the lesser curvature and posterior wall.A small ulcer at the distal end of the mass was identified as the source of the bleeding.Biopsy was negative for neoplasia.Computed tomography showed a submucosal lesion beneath the affected mucosa,most likely a lipoma.The mass was removed en bloc with tunneling endoscopic submucosal dissection.Final pathology determined that the mass included Ménétrier’s disease and a submucosal lipoma.The patient was scheduled for follow-up esophagogastroduodenoscopy.CONCLUSION Localized Ménétrier’s disease can coexist with a submucosal lipoma creating a polypoid mass with risk of bleeding.展开更多
TMEM16F is involved in many physiological processes such as blood coagulation,cell membrane fusion and bone mineralization.Activation of TMEM16F has been studied in various central nervous system diseases.High TMEM16F...TMEM16F is involved in many physiological processes such as blood coagulation,cell membrane fusion and bone mineralization.Activation of TMEM16F has been studied in various central nervous system diseases.High TMEM16F level has been also found to participate in microglial phagocytosis and transformation.Microglia-mediated neuroinflammation is a key factor in promoting the progression of Alzheimer’s disease.However,few studies have examined the effects of TMEM16F on neuroinflammation in Alzheimer’s disease.In this study,we established TMEM16F-knockdown AD model in vitro and in vivo to investigate the underlying regulatory mechanism about TMEM16F-mediated neuroinflammation in AD.We performed a Morris water maze test to evaluate the spatial memory ability of animals and detected markers for the microglia M1/M2 phenotype and NLRP3 inflammasome.Our results showed that TMEM16F was elevated in 9-month-old APP/PS1 mice.After TMEM16F knockdown in mice,spatial memory ability was improved,microglia polarization to the M2 phenotype was promoted,NLRP3 inflammasome activation was inhibited,cell apoptosis and Aβplaque deposition in brain tissue were reduced,and brain injury was alleviated.We used amyloid-beta(Aβ_(25-35))to stimulate human microglia to construct microglia models of Alzheimer’s disease.The levels of TMEM16F,inducible nitric oxide synthase(iNOS),proinflammatory cytokines and NLRP3 inflammasome-associated biomarkers were higher in Aβ_(25-35) treated group compared with that in the control group.TMEM16F knockdown enhanced the expression of the M2 phenotype biomarkers Arg1 and Socs3,reduced the release of proinflammatory factors interleukin-1,interleukin-6 and tumor necrosis factor-α,and inhibited NLRP3 inflammasome activation through reducing downstream proinflammatory factors interleukin-1βand interleukin-18.This inhibitory effect of TMEM16F knockdown on M1 microglia was partially reversed by the NLRP3 agonist Nigericin.Our findings suggest that TMEM16F participates in neuroinflammation in Alzheimer’s disease through participating in polarization of microglia and activation of the NLRP3 inflammasome.These results indicate that TMEM16F inhibition may be a potential therapeutic approach for Alzheimer’s disease treatment.展开更多
Background: The aim of this study was to identify the prevalence of tinnitus in a sample of people with early stages of Ménière’s disease. Material and methods: A postal survey was sent to 256 patients all ...Background: The aim of this study was to identify the prevalence of tinnitus in a sample of people with early stages of Ménière’s disease. Material and methods: A postal survey was sent to 256 patients all judged to fulfil the criteria of early unilateral Ménière’s disease established by the American Academy of Otolaryngology Committee on Hearing and Equilibrium. Of these 256 patients, 136 had probable Ménière’s disease and 120 had early possible Ménière’s disease. The same questionnaire was mailed and administered to 60 control subjects with no history of vestibular dysfunction. A total of 158 subjects completed the questionnaire. Results: Tinnitus was found in 54 (63%) of the 72 members of the final unilateral vestibular Ménière’s disease group and 61 (85 %) of the 72 members of the final unilateral probable Ménière’s disease group. Conclusion: The prevalence of tinnitus as determined by a questionnaire survey was significantly greater in patients with probable Ménière’s disease than in patients with early vestibular Ménière’s disease or in control subjects. However, the prevalence of tinnitus as determined by a questionnaire survey was significantly greater in patients with early vestibular Ménière’s disease than in control subjects.展开更多
AIM:To evaluate the clinical value of the newly modified Simple Endoscopic Score for Crohn's disease(m SES-CD).METHODS:Seventy-six Crohn's disease(CD) patients who underwent transanal double balloon endoscopy(...AIM:To evaluate the clinical value of the newly modified Simple Endoscopic Score for Crohn's disease(m SES-CD).METHODS:Seventy-six Crohn's disease(CD) patients who underwent transanal double balloon endoscopy(DBE) in our hospital between 2003 and 2012 were retrospectively reviewed. DBE is defined as small intestinal endoscopy using two attached balloons. We included patients with stenosis which hampered passage of the scope and those who underwent DBE with observation for at least 80 cm from the ileocecal valve. Our new m SES-CD assesses the endoscopic activity of two consecutive small intestinal segments located 0-40 cm and 40-80 cm from the ileocecal valve by DBE,in addition to the activity of four colorectal segments. To compare the usefulness of m SES-CD with SES-CD,we similarly divided the patients into two groups according to total m SES-CD score(low disease activity group,< 4; high disease activity group,≥ 4). The clinical value of m SES-CD in predicting clinical outcome in patients with CD was evaluated using the occurrence of surgery after DBE as an endpoint.RESULTS:Median age of the 76 CD patients was 36 years(range,16-71). Thirty-nine patients had stenosis which hampered passage of the DBE to 80 cm on the proximal side from the ileocecal valve. Median evaluable length of small intestine by DBE was 80 cm(range,3-200). A total of 74 patients had one or more small intestinal lesions detected by DBE,of which 62(83.8%) were within 80 cm of the ileocecal valve on the proximal side. Only two patients(2.7%) with proximal-side lesions more than 80 cm from the ileocecal valve did not have lesions within 80 cm. Patients with high m SES-CD scores showed significantly shorter surgeryfree survival than those with low scores(P < 0.05). In contrast,surgery-free survival did not significantly differ between the low and high SES-CD groups(P > 0.05). Multivariate analysis by a Cox proportional hazards model identified m SES-CD as an independent factor for surgery-free survival.CONCLUSION:m SES-CD is useful in evaluating the risk of surgery-free survival in patients with CD.展开更多
This study looked into the efficacy of a modified titration protocol of intratympanic gentamicin injection（ITG） in the patients with unilateral intractable Ménière＇s disease（MD）. Modified titration prot...This study looked into the efficacy of a modified titration protocol of intratympanic gentamicin injection（ITG） in the patients with unilateral intractable Ménière＇s disease（MD）. Modified titration protocol of ITG at a low dose（20 mg/m L） was administered to 10 patients with definite unilateral intractable MD. After initial first two fixed ITGs on weekly basis,the patients might or might not be given any more injections,depending on the appearance of unilateral vestibular loss（UVL）. ITG was terminated if the patients satisfied the criteria of UVL. All patients were followed-up for at least two years. The effects of ITG on the vertigo attack,functional level scores and postural balance were evaluated. Of the 10 cases,8 showed the sign of UVL after receiving initial two ITGs and were not given any more intratympanic injections,and the other 2 patients were administered three ITGs. A two-year follow-up revealed that complete and substantial vertigo control was achieved in 9 cases,and limited vertigo control in 1 patient. Hearing level was lowered in 2 patients. The posture stability and functional level scores were improved. Our study showed that the modified titration protocol of ITG at a low dose could effectively control vertigo in patients with unilateral intractable MD.展开更多
Ménière's disease(MD) is a common cause of recurrent vertigo. Its pathophysiology is still unclear and controversial. The most common histological finding in postmortem temporal bone studies of patients ...Ménière's disease(MD) is a common cause of recurrent vertigo. Its pathophysiology is still unclear and controversial. The most common histological finding in postmortem temporal bone studies of patients is endolymphatic hydrops(EH). However, not all cases of hydrops are associated with MD and it may represent the end point of various etiologies. The diagnostic criteria for MD have undergone changes during the past few decades. A recent collaboration among specialty societies in United States, Europe and Japan has given rise to a new set of guidelines for the diagnosis and classification of MD. The aim is to develop international consensus criteria for MD that would help improve the quality of data collected from patients. The diagnosis of MD can be difficult in some cases as there is no gold standard for testing. Previous use of audiometric data and electrocochleography are poorly sensitive as screening tools. Recently magnetic resonance imaging as a diagnostic tool for identifying EH has gained popularity in Asia and Europe. Vestibular evoked myogenic potentials are also used but lack specificity. Finally, the treatment for MD has improved with the introduction of intratympanic treatments with steroids and gentamicin as well as less invasive treatment with the Meniett device.展开更多
The diagnosis of inflammatory bowel disease(IBD) depends on direct endoscopic visualization of the colonic and ileal mucosa and the histological study of the obtained samples.Radiological and scintigraphic methods are...The diagnosis of inflammatory bowel disease(IBD) depends on direct endoscopic visualization of the colonic and ileal mucosa and the histological study of the obtained samples.Radiological and scintigraphic methods are mainly used as an adjunct to endoscopy.In this review,we focus on the diagnostic potential of nuclear medicine procedures.The value of all radiotracers is described with special reference to those with greater experience and more satisfactory results.Tc-99m hexamethylpropylene amine oxime white blood cells remain a widely acceptable scintigraphic method for the diagnosis of IBD,as well as for the evaluation of disease extension and severity.Recently,pentavalent Tc-99m dimercaptosuccinic acid has been recommended as an accurate variant and a complementary technique to endoscopy for the follow-up and assessment of disease activity.Positron emission tomography alone or with computed tomography using fluorine-18 fluorodeoxyglucose appears to be a promising method of measuring inflammation in IBD patients.展开更多
AIM: To investigate variants of immunity-related GT-Pase family M (IRGM) and NKX2-3 genes and genotype-phenotype in Eastern European patients with inflammatory bowel disease (IBD).METHODS: We analyzed 1707 Hungarian a...AIM: To investigate variants of immunity-related GT-Pase family M (IRGM) and NKX2-3 genes and genotype-phenotype in Eastern European patients with inflammatory bowel disease (IBD).METHODS: We analyzed 1707 Hungarian and Czech subjects with Crohn’s disease (CD) (n = 810, age: 37.1 ± 12.6 years, duration: 10.7 ± 8.4 years) and ulcerative colitis (UC) (n = 428, age: 43.7 ± 15.0 years, duration: 12.6 ± 9.9 years), as well as 469 healthy controls. IRGM rs13361189, NKX2-3 rs10883365 and ECM1 rs13294 polymorphisms were tested by LightCy-cler allele discrimination. Detailed clinical phenotypes were determined by reviewing the medical charts. RESULTS: NKX2-3 rs10883365 variant allele was as-sociated with increased risk for CD (P = 0.009, OR = 1.24, 95% CI = 1.06-1.48) and UC (P = 0.001, OR = 1.36, 95% CI = 1.13-1.63), whereas variant IRGM allele increased risk for CD (P = 0.029, OR = 1.36, 95% CI = 1.03-1.79). In contrast, ECM1 rs13294 was not associat-ed with either CD or UC. In CD, the variant IRGM allele was associated with a colon-only location (P = 0.02, OR = 1.62, 95% CI = 1.07-2.44), whereas in UC, the ECM1 variant was associated with cutaneous manifestations (P = 0.002, OR = 3.36, 95% CI = 1.48-7.63). Variant alleles did not predict resistance to steroids or azathio-prine, efficacy of infliximab, or need for surgery. CONCLUSION: NKX2-3 and IRGM are susceptibility locifor IBD in Eastern European patients. Further studies are needed to confirm the reported phenotype-genotype associations.展开更多
BACKGROUND Adult-onset Ménétrier’s disease is strongly associated with Helicobacter pylori(H.pylori)infection and an elevated risk of carcinogenesis.Cases of early-stage gastric cancer developed in H.pylori...BACKGROUND Adult-onset Ménétrier’s disease is strongly associated with Helicobacter pylori(H.pylori)infection and an elevated risk of carcinogenesis.Cases of early-stage gastric cancer developed in H.pylori-negative Ménétrier’s disease are extremely rare.We report a case of early gastric cancer in H.pylori-negative Ménétrier’s disease that was curatively resected with endoscopic submucosal dissection(ESD).CASE SUMMARY A 60-year-old woman was referred to our hospital after her medical examination detected anemia.Contrast-enhanced upper gastrointestinal(UGI)radiography revealed translucency of the nodule-aggregating surface with giant rugae.Blood tests showed hypoproteinemia and were negative for serum H.pylori immunoglobulin G antibodies.The 99mTc-DTPA-human serum albumin scintigraphy showed protein loss from the stomach.UGI endoscopy showed a 40-mm protruding erythematous lesion on giant rugae of the greater curvature of lower gastric body,suggesting early-stage gastric cancer due to Ménétrier’s disease.En bloc resection with ESD was performed for diagnosis and treatment.Histology of ESD showed well-differentiated tubular adenocarcinoma.The cancer was confined to the mucosa,and complete curative resection was achieved.Foveolar hyperplasia and atrophy of the gastric glands were observed in non-tumor areas,histologically corresponding to Ménétrier’s disease.Three years after ESD,gastric cancer had not recurred,and Ménétrier’s disease remained in remission with spontaneous regression of giant gastric rugae.CONCLUSION Complete curative resection was achieved through ESD in a patient with earlystage gastric cancer and H.pylori-negative Ménétrier’s disease.展开更多
The timely and efficient elimination of aberrant proteins and damaged organelles, formed in response to various genetic and environmental stressors, is a vital need for all cells of the body. Recent lines of evidence ...The timely and efficient elimination of aberrant proteins and damaged organelles, formed in response to various genetic and environmental stressors, is a vital need for all cells of the body. Recent lines of evidence point out several non-classical strategies employed by ocular tissues to cope with aberrant constituents generated in the retina and in the retinal pigmented epithelium cells exposed to various stressors. Along with conventional strategies relying upon the intracellular degradation of aberrant constituents through ubiquitin-proteasome and/or lysosome-dependent autophagy proteolysis, two non-conventional mechanisms also contribute to proteostasis maintenance in ocular tissues. An exosome-mediated clearing and a myelinosome-driven secretion mechanism do not require intracellular degradation but provide the export of aberrant constituents and “waste proteins” outside of the cells. The current review is centered on the non-degradative myelinosome-driven secretion mechanism, which operates in the retina of transgenic Huntington’s disease R6/1 model mice. Myelinosome-driven secretion is supported by rare organelles myelinosomes that are detected not only in degenerative Huntington’s disease R6/1 retina but also in various pathological states of the retina and of the retinal pigmented epithelium. The intra-retinal traffic and inter-cellular exchange of myelinosomes was discussed in the context of a dual role of the myelinosome-driven secretion mechanism for proteostasis maintenance in different ocular compartments. Special focus was made on the interplay between degradative and non-degradative strategies in ocular pathophysiology, to delineate potential therapeutic approaches to counteract several vision diseases.展开更多
Objective:To better understand the clinical phenotype of Méenière’s disease(MD),we examined family history,thyroid disorder,migraine,and associated disorders in complaints of people living with MD.Method:We...Objective:To better understand the clinical phenotype of Méenière’s disease(MD),we examined family history,thyroid disorder,migraine,and associated disorders in complaints of people living with MD.Method:We designed the study as a retrospective and examined data gathered from 912 participants with MD.Their data were originally collected by the Finnish M′eni`ere Federation(FMF).The survey data included individual case histories for environmental factors,comorbidities,disease-specific complaints,impact-related questions,cognitive complaints,health-related quality of life(HRQoL),and sense of coherence(SOC).Results:We observed significant differences between those with and without sporadic occurrence,family history,thyroid disorder,and migraine-associated complaints.Family history explained 20%of variability in patient complaints.Patients with a family history of MD whose disease started at younger age experienced balance problems,more severe vertigo spells,more severe vestibular drop attacks(VDA),and less nausea,although they had good SOC.Thyroid disorder explained 14%of variability in patient complaints.MD patients with a thyroid disorder comorbidity suffered more often from constant dizziness,balance problems,greater impact of hearing problems,cognitive complaints,and poor HRQoL.Migraine explained 12%of variability in patients’complaints and was associated with poor SOC and cognitive balance problems.MD patients with both thyroid disorder and migraine used antidepressants more often than other groups.Logistic regression analysis showed comorbidities of ischemic brain disorder(among 7.1%),kidney insufficiency(among 1.2%),and diabetes(among 7.3%)had statistically significant but restricted association with balance and gait problems,VDA,and reduced HRQoL.Conclusions:Family history of MD and thyroid disorder or migraine comorbidities in MD influence the complaint pattern and partially explain complex symptom profiles,including symptoms of cognitive problems.Confounders play a minimal role in complaint profile and impact of MD whereas comorbidities influence the complaint structure and partly explain the complex symptom profile in MD.展开更多
To discover new lead compounds for M1 agonists. Ten typical M1 agonists were superimposed to build a M1 agonists 3D-pharmacophore model using distance-comparisons （DISCO） method without the previous knowledge of the...To discover new lead compounds for M1 agonists. Ten typical M1 agonists were superimposed to build a M1 agonists 3D-pharmacophore model using distance-comparisons （DISCO） method without the previous knowledge of the three-dimensional structure of M1 receptor. Virtual screening strategy was used to analyze the Available Chemicals Directory-Screening Compounds （ACD-SC） to identify possible new hits. Twenty-two compounds which fit the pharmacophore model well and are not similar with known M1 agonists were purchased in order to evaluate their M1 receptor agonist activity. One of them shows M1 receptor agonist activity with EC50 of 4.90 μmol/L and maximum response. Multiple of 10.0 which shows it worthy of further study as a new lead compound for M1 agonists.展开更多
Lycium barbarum(LB)is a traditional Chinese medicine that has been demonstrated to exhibit a wide variety of biological functions,such as antioxidation,neuroprotection,and immune modulation.One of the main mechanisms ...Lycium barbarum(LB)is a traditional Chinese medicine that has been demonstrated to exhibit a wide variety of biological functions,such as antioxidation,neuroprotection,and immune modulation.One of the main mechanisms of Alzheimer’s disease is that microglia activated by amyloid beta(Aβ)transform from the resting state to an M1 state and release pro-inflammatory cytokines to the surrounding environment.In the present study,immortalized microglial cells were pretreated with L.barbarum extract for 1 hour and then treated with oligomeric Aβfor 23 hours.The results showed that LB extract significantly increased the survival of oligomeric Aβ-induced microglial cells,downregulated the expression of M1 pro-inflammatory markers(inducible nitric oxide synthase,tumor necrosis factorα,interleukin-6,and interleukin-1β),and upregulated the expression of M2 anti-inflammatory markers(arginase-1,chitinase-like protein 3,and interleukin-4).LB extract also inhibited the oligomeric Aβ-induced secretion of tumor necrosis factorα,interleukin-6,and interleukin-1βin microglial cells.The results of in vitro cytological experiments suggest that,in microglial cells,LB extract can inhibit oligomeric Aβ-induced M1 polarization and concomitant inflammatory reactions,and promote M2 polarization.展开更多
Astrocytes protect neurons by modulating neuronal function and survival.Astrocytes support neurons in several ways.They provide energy through the astrocyte-neuron lactate shuttle,protect neurons from excitotoxicity,a...Astrocytes protect neurons by modulating neuronal function and survival.Astrocytes support neurons in several ways.They provide energy through the astrocyte-neuron lactate shuttle,protect neurons from excitotoxicity,and internalize neuronal lipid droplets to degrade fatty acids for neuronal metabolic and synaptic support,as well as by their high capacity for glutamate uptake and the conversion of glutamate to glutamine.A recent reported astrocyte system for protection of dopamine neurons against the neurotoxic products of dopamine,such as aminochrome and other o-quinones,were generated under neuromelanin synthesis by oxidizing dopamine catechol structure.Astrocytes secrete glutathione transferase M2-2 through exosomes that transport this enzyme into dopaminergic neurons to protect these neurons against aminochrome neurotoxicity.The role of this new astrocyte protective mechanism in Parkinson´s disease is discussed.展开更多
基金supported by the National Natural Science Foundation of China,Nos.82071190 and 82371438(to LC)Innovative Strong School Project of Guangdong Medical University,No.4SG21230G(to LC)Scientific Research Foundation of Guangdong Medical University,No.GDMUM2020017(to CL)。
文摘Alzheimer s disease,among the most common neurodegenerative disorders,is chara cterized by progressive cognitive impairment.At present,the Alzheimer’s disease main risk remains genetic ris ks,but major environmental fa ctors are increasingly shown to impact Alzheimer’s disease development and progression.Microglia,the most important brain immune cells,play a central role in Alzheimer’s disease pathogenesis and are considered environmental and lifestyle"sensors."Factors like environmental pollution and modern lifestyles(e.g.,chronic stress,poor dietary habits,sleep,and circadian rhythm disorde rs)can cause neuroinflammato ry responses that lead to cognitive impairment via microglial functioning and phenotypic regulation.However,the specific mechanisms underlying interactions among these facto rs and microglia in Alzheimer’s disease are unclear.Herein,we:discuss the biological effects of air pollution,chronic stress,gut micro biota,sleep patterns,physical exercise,cigarette smoking,and caffeine consumption on microglia;consider how unhealthy lifestyle factors influence individual susceptibility to Alzheimer’s disease;and present the neuroprotective effects of a healthy lifestyle.Toward intervening and controlling these environmental risk fa ctors at an early Alzheimer’s disease stage,understanding the role of microglia in Alzheimer’s disease development,and to rgeting strategies to to rget microglia,co uld be essential to future Alzheimer’s disease treatments.
基金supported by the National Natural Science Foundation of China,Nos.82171429,81771384a grant from Wuxi Municipal Health Commission,No.1286010241190480(all to YS)。
文摘Interferon regulatory factor 7 plays a crucial role in the innate immune response.However,whether interferon regulatory factor 7-mediated signaling contributes to Parkinson's disease remains unknown.Here we report that interferon regulatory factor 7 is markedly up-regulated in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced mouse model of Parkinson's disease and co-localizes with microglial cells.Both the selective cyclic guanosine monophosphate adenosine monophosphate synthase inhibitor RU.521 and the stimulator of interferon genes inhibitor H151 effectively suppressed interferon regulatory factor 7 activation in BV2 microglia exposed to 1-methyl-4-phenylpyridinium and inhibited transformation of mouse BV2 microglia into the neurotoxic M1 phenotype.In addition,si RNA-mediated knockdown of interferon regulatory factor 7 expression in BV2 microglia reduced the expression of inducible nitric oxide synthase,tumor necrosis factorα,CD16,CD32,and CD86 and increased the expression of the anti-inflammatory markers ARG1 and YM1.Taken together,our findings indicate that the cyclic guanosine monophosphate adenosine monophosphate synthase-stimulator of interferon genes-interferon regulatory factor 7 pathway plays a crucial role in the pathogenesis of Parkinson's disease.
文摘BACKGROUND Oncostatin M(OSM)is a pleiotropic cytokine which is implicated in the path-ogenesis of inflammatory bowel disease(IBD).AIM To evaluate the prognostic role of OSM in IBD patients.METHODS Literature search was conducted in electronic databases(Google Scholar,Embase,PubMed,Science Direct,Springer,and Wiley).Studies were selected if they reported prognostic information about OSM in IBD patients.Outcome data were synthesized,and meta-analyses were performed to estimate standardized mean differences(SMDs)in OSM levels between treatment responders and non-res-ponders and to seek overall correlations of OSM with other inflammatory bio-markers.RESULTS Sixteen studies(818 Crohn’s disease and 686 ulcerative colitis patients treated with anti-tumor necrosis factor-based therapies)were included.OSM levels were associated with IBD severity.A meta-analysis found significantly higher OSM levels in non-responders than in responders to therapy[SMD 0.80(0.33,1.27);P=0.001],in non-remitters than in remitters[SMD 0.75(95%CI:0.35 to 1.16);P<0.0001]and in patients with no mucosal healing than in those with mucosal heal-ing[SMD 0.63(0.30,0.95);P<0.0001].Area under receiver operator curve values showed considerable variability between studies but in general higher OSM levels were associated with poor prognosis.OSM had significant correlations with Simple Endoscopic Score of Crohn’s disease[r=0.47(95%CI:0.25 to 0.64);P<0.0001],Mayo Endoscopic Score[r=0.35(95%CI:0.28 to 0.41);P<0.0001],fecal calprotectin[r=0.19(95%CI:0.08 to 0.3);P=0.001],C-reactive protein[r=0.25(95%CI:0.11 to 0.39);P<0.0001],and platelet count[r=0.28(95%CI:0.17 to 0.39);P<0.0001].CONCLUSION OSM is a potential candidate for determining the severity of disease and predicting the outcomes of anti-tumor necrosis factor-based therapies in IBD patients.
文摘BACKGROUND Ménétrier’s disease is a rare condition characterized by enlarged gastric folds,usually located in the whole body and fundus of the stomach.This report presents an unusual case of localized Ménétrier’s disease elevated by a submucosal lipoma and thus looking like a polypoid mass and causing an episode of upper gastrointestinal bleeding.The mass was successfully removed with endoscopic submucosal dissection.CASE SUMMARY Esophagogastroduodenoscopy was performed on a 76-year-old male patient after an episode of upper gastrointestinal bleeding,manifesting as fatigue and melena.A large polypoid mass(4 cm×1 cm)with enlarged mucosal folds was found in the body of the stomach,between the lesser curvature and posterior wall.A small ulcer at the distal end of the mass was identified as the source of the bleeding.Biopsy was negative for neoplasia.Computed tomography showed a submucosal lesion beneath the affected mucosa,most likely a lipoma.The mass was removed en bloc with tunneling endoscopic submucosal dissection.Final pathology determined that the mass included Ménétrier’s disease and a submucosal lipoma.The patient was scheduled for follow-up esophagogastroduodenoscopy.CONCLUSION Localized Ménétrier’s disease can coexist with a submucosal lipoma creating a polypoid mass with risk of bleeding.
基金supported by the National Natural Science Foundation of China,No.82072941(to QHX)Liaoning Province Key R&D Program Guidance Project,No.2020JH2/10300044Science and Technology Plan Project of Shenyang,No.20-205-4-050(both to XHS)。
文摘TMEM16F is involved in many physiological processes such as blood coagulation,cell membrane fusion and bone mineralization.Activation of TMEM16F has been studied in various central nervous system diseases.High TMEM16F level has been also found to participate in microglial phagocytosis and transformation.Microglia-mediated neuroinflammation is a key factor in promoting the progression of Alzheimer’s disease.However,few studies have examined the effects of TMEM16F on neuroinflammation in Alzheimer’s disease.In this study,we established TMEM16F-knockdown AD model in vitro and in vivo to investigate the underlying regulatory mechanism about TMEM16F-mediated neuroinflammation in AD.We performed a Morris water maze test to evaluate the spatial memory ability of animals and detected markers for the microglia M1/M2 phenotype and NLRP3 inflammasome.Our results showed that TMEM16F was elevated in 9-month-old APP/PS1 mice.After TMEM16F knockdown in mice,spatial memory ability was improved,microglia polarization to the M2 phenotype was promoted,NLRP3 inflammasome activation was inhibited,cell apoptosis and Aβplaque deposition in brain tissue were reduced,and brain injury was alleviated.We used amyloid-beta(Aβ_(25-35))to stimulate human microglia to construct microglia models of Alzheimer’s disease.The levels of TMEM16F,inducible nitric oxide synthase(iNOS),proinflammatory cytokines and NLRP3 inflammasome-associated biomarkers were higher in Aβ_(25-35) treated group compared with that in the control group.TMEM16F knockdown enhanced the expression of the M2 phenotype biomarkers Arg1 and Socs3,reduced the release of proinflammatory factors interleukin-1,interleukin-6 and tumor necrosis factor-α,and inhibited NLRP3 inflammasome activation through reducing downstream proinflammatory factors interleukin-1βand interleukin-18.This inhibitory effect of TMEM16F knockdown on M1 microglia was partially reversed by the NLRP3 agonist Nigericin.Our findings suggest that TMEM16F participates in neuroinflammation in Alzheimer’s disease through participating in polarization of microglia and activation of the NLRP3 inflammasome.These results indicate that TMEM16F inhibition may be a potential therapeutic approach for Alzheimer’s disease treatment.
文摘Background: The aim of this study was to identify the prevalence of tinnitus in a sample of people with early stages of Ménière’s disease. Material and methods: A postal survey was sent to 256 patients all judged to fulfil the criteria of early unilateral Ménière’s disease established by the American Academy of Otolaryngology Committee on Hearing and Equilibrium. Of these 256 patients, 136 had probable Ménière’s disease and 120 had early possible Ménière’s disease. The same questionnaire was mailed and administered to 60 control subjects with no history of vestibular dysfunction. A total of 158 subjects completed the questionnaire. Results: Tinnitus was found in 54 (63%) of the 72 members of the final unilateral vestibular Ménière’s disease group and 61 (85 %) of the 72 members of the final unilateral probable Ménière’s disease group. Conclusion: The prevalence of tinnitus as determined by a questionnaire survey was significantly greater in patients with probable Ménière’s disease than in patients with early vestibular Ménière’s disease or in control subjects. However, the prevalence of tinnitus as determined by a questionnaire survey was significantly greater in patients with early vestibular Ménière’s disease than in control subjects.
文摘AIM:To evaluate the clinical value of the newly modified Simple Endoscopic Score for Crohn's disease(m SES-CD).METHODS:Seventy-six Crohn's disease(CD) patients who underwent transanal double balloon endoscopy(DBE) in our hospital between 2003 and 2012 were retrospectively reviewed. DBE is defined as small intestinal endoscopy using two attached balloons. We included patients with stenosis which hampered passage of the scope and those who underwent DBE with observation for at least 80 cm from the ileocecal valve. Our new m SES-CD assesses the endoscopic activity of two consecutive small intestinal segments located 0-40 cm and 40-80 cm from the ileocecal valve by DBE,in addition to the activity of four colorectal segments. To compare the usefulness of m SES-CD with SES-CD,we similarly divided the patients into two groups according to total m SES-CD score(low disease activity group,< 4; high disease activity group,≥ 4). The clinical value of m SES-CD in predicting clinical outcome in patients with CD was evaluated using the occurrence of surgery after DBE as an endpoint.RESULTS:Median age of the 76 CD patients was 36 years(range,16-71). Thirty-nine patients had stenosis which hampered passage of the DBE to 80 cm on the proximal side from the ileocecal valve. Median evaluable length of small intestine by DBE was 80 cm(range,3-200). A total of 74 patients had one or more small intestinal lesions detected by DBE,of which 62(83.8%) were within 80 cm of the ileocecal valve on the proximal side. Only two patients(2.7%) with proximal-side lesions more than 80 cm from the ileocecal valve did not have lesions within 80 cm. Patients with high m SES-CD scores showed significantly shorter surgeryfree survival than those with low scores(P < 0.05). In contrast,surgery-free survival did not significantly differ between the low and high SES-CD groups(P > 0.05). Multivariate analysis by a Cox proportional hazards model identified m SES-CD as an independent factor for surgery-free survival.CONCLUSION:m SES-CD is useful in evaluating the risk of surgery-free survival in patients with CD.
基金supported by the National Science&Technology Pillar Program during the 12th Five-year Plan of China(No.2012BAI12B02)the 11th Five-year Plan of China(No.2007BAI18B13)National Natural Science Foundation of China(No.30872865)
文摘This study looked into the efficacy of a modified titration protocol of intratympanic gentamicin injection（ITG） in the patients with unilateral intractable Ménière＇s disease（MD）. Modified titration protocol of ITG at a low dose（20 mg/m L） was administered to 10 patients with definite unilateral intractable MD. After initial first two fixed ITGs on weekly basis,the patients might or might not be given any more injections,depending on the appearance of unilateral vestibular loss（UVL）. ITG was terminated if the patients satisfied the criteria of UVL. All patients were followed-up for at least two years. The effects of ITG on the vertigo attack,functional level scores and postural balance were evaluated. Of the 10 cases,8 showed the sign of UVL after receiving initial two ITGs and were not given any more intratympanic injections,and the other 2 patients were administered three ITGs. A two-year follow-up revealed that complete and substantial vertigo control was achieved in 9 cases,and limited vertigo control in 1 patient. Hearing level was lowered in 2 patients. The posture stability and functional level scores were improved. Our study showed that the modified titration protocol of ITG at a low dose could effectively control vertigo in patients with unilateral intractable MD.
文摘Ménière's disease(MD) is a common cause of recurrent vertigo. Its pathophysiology is still unclear and controversial. The most common histological finding in postmortem temporal bone studies of patients is endolymphatic hydrops(EH). However, not all cases of hydrops are associated with MD and it may represent the end point of various etiologies. The diagnostic criteria for MD have undergone changes during the past few decades. A recent collaboration among specialty societies in United States, Europe and Japan has given rise to a new set of guidelines for the diagnosis and classification of MD. The aim is to develop international consensus criteria for MD that would help improve the quality of data collected from patients. The diagnosis of MD can be difficult in some cases as there is no gold standard for testing. Previous use of audiometric data and electrocochleography are poorly sensitive as screening tools. Recently magnetic resonance imaging as a diagnostic tool for identifying EH has gained popularity in Asia and Europe. Vestibular evoked myogenic potentials are also used but lack specificity. Finally, the treatment for MD has improved with the introduction of intratympanic treatments with steroids and gentamicin as well as less invasive treatment with the Meniett device.
文摘The diagnosis of inflammatory bowel disease(IBD) depends on direct endoscopic visualization of the colonic and ileal mucosa and the histological study of the obtained samples.Radiological and scintigraphic methods are mainly used as an adjunct to endoscopy.In this review,we focus on the diagnostic potential of nuclear medicine procedures.The value of all radiotracers is described with special reference to those with greater experience and more satisfactory results.Tc-99m hexamethylpropylene amine oxime white blood cells remain a widely acceptable scintigraphic method for the diagnosis of IBD,as well as for the evaluation of disease extension and severity.Recently,pentavalent Tc-99m dimercaptosuccinic acid has been recommended as an accurate variant and a complementary technique to endoscopy for the follow-up and assessment of disease activity.Positron emission tomography alone or with computed tomography using fluorine-18 fluorodeoxyglucose appears to be a promising method of measuring inflammation in IBD patients.
基金Supported by An unrestricted research grant from Abbott Labora-toriesan OTKA postdoctoral fellowship (PF63953) (to Andrikov-ics H)+2 种基金the Bolyai Janos Postdoctoral Scholarship of the Hungar-ian Academy of Sciences (to Lakatos PL)No. NR/9219-3/2007 of the Internal Grant Agency of the Czech Ministry of Health (to Lukas M)Generation of the Czech IBD as well as control data-bases was enabled by the support of a grant given by the Czech Ministry of Education No. 2B06155
文摘AIM: To investigate variants of immunity-related GT-Pase family M (IRGM) and NKX2-3 genes and genotype-phenotype in Eastern European patients with inflammatory bowel disease (IBD).METHODS: We analyzed 1707 Hungarian and Czech subjects with Crohn’s disease (CD) (n = 810, age: 37.1 ± 12.6 years, duration: 10.7 ± 8.4 years) and ulcerative colitis (UC) (n = 428, age: 43.7 ± 15.0 years, duration: 12.6 ± 9.9 years), as well as 469 healthy controls. IRGM rs13361189, NKX2-3 rs10883365 and ECM1 rs13294 polymorphisms were tested by LightCy-cler allele discrimination. Detailed clinical phenotypes were determined by reviewing the medical charts. RESULTS: NKX2-3 rs10883365 variant allele was as-sociated with increased risk for CD (P = 0.009, OR = 1.24, 95% CI = 1.06-1.48) and UC (P = 0.001, OR = 1.36, 95% CI = 1.13-1.63), whereas variant IRGM allele increased risk for CD (P = 0.029, OR = 1.36, 95% CI = 1.03-1.79). In contrast, ECM1 rs13294 was not associat-ed with either CD or UC. In CD, the variant IRGM allele was associated with a colon-only location (P = 0.02, OR = 1.62, 95% CI = 1.07-2.44), whereas in UC, the ECM1 variant was associated with cutaneous manifestations (P = 0.002, OR = 3.36, 95% CI = 1.48-7.63). Variant alleles did not predict resistance to steroids or azathio-prine, efficacy of infliximab, or need for surgery. CONCLUSION: NKX2-3 and IRGM are susceptibility locifor IBD in Eastern European patients. Further studies are needed to confirm the reported phenotype-genotype associations.
文摘BACKGROUND Adult-onset Ménétrier’s disease is strongly associated with Helicobacter pylori(H.pylori)infection and an elevated risk of carcinogenesis.Cases of early-stage gastric cancer developed in H.pylori-negative Ménétrier’s disease are extremely rare.We report a case of early gastric cancer in H.pylori-negative Ménétrier’s disease that was curatively resected with endoscopic submucosal dissection(ESD).CASE SUMMARY A 60-year-old woman was referred to our hospital after her medical examination detected anemia.Contrast-enhanced upper gastrointestinal(UGI)radiography revealed translucency of the nodule-aggregating surface with giant rugae.Blood tests showed hypoproteinemia and were negative for serum H.pylori immunoglobulin G antibodies.The 99mTc-DTPA-human serum albumin scintigraphy showed protein loss from the stomach.UGI endoscopy showed a 40-mm protruding erythematous lesion on giant rugae of the greater curvature of lower gastric body,suggesting early-stage gastric cancer due to Ménétrier’s disease.En bloc resection with ESD was performed for diagnosis and treatment.Histology of ESD showed well-differentiated tubular adenocarcinoma.The cancer was confined to the mucosa,and complete curative resection was achieved.Foveolar hyperplasia and atrophy of the gastric glands were observed in non-tumor areas,histologically corresponding to Ménétrier’s disease.Three years after ESD,gastric cancer had not recurred,and Ménétrier’s disease remained in remission with spontaneous regression of giant gastric rugae.CONCLUSION Complete curative resection was achieved through ESD in a patient with earlystage gastric cancer and H.pylori-negative Ménétrier’s disease.
文摘The timely and efficient elimination of aberrant proteins and damaged organelles, formed in response to various genetic and environmental stressors, is a vital need for all cells of the body. Recent lines of evidence point out several non-classical strategies employed by ocular tissues to cope with aberrant constituents generated in the retina and in the retinal pigmented epithelium cells exposed to various stressors. Along with conventional strategies relying upon the intracellular degradation of aberrant constituents through ubiquitin-proteasome and/or lysosome-dependent autophagy proteolysis, two non-conventional mechanisms also contribute to proteostasis maintenance in ocular tissues. An exosome-mediated clearing and a myelinosome-driven secretion mechanism do not require intracellular degradation but provide the export of aberrant constituents and “waste proteins” outside of the cells. The current review is centered on the non-degradative myelinosome-driven secretion mechanism, which operates in the retina of transgenic Huntington’s disease R6/1 model mice. Myelinosome-driven secretion is supported by rare organelles myelinosomes that are detected not only in degenerative Huntington’s disease R6/1 retina but also in various pathological states of the retina and of the retinal pigmented epithelium. The intra-retinal traffic and inter-cellular exchange of myelinosomes was discussed in the context of a dual role of the myelinosome-driven secretion mechanism for proteostasis maintenance in different ocular compartments. Special focus was made on the interplay between degradative and non-degradative strategies in ocular pathophysiology, to delineate potential therapeutic approaches to counteract several vision diseases.
文摘Objective:To better understand the clinical phenotype of Méenière’s disease(MD),we examined family history,thyroid disorder,migraine,and associated disorders in complaints of people living with MD.Method:We designed the study as a retrospective and examined data gathered from 912 participants with MD.Their data were originally collected by the Finnish M′eni`ere Federation(FMF).The survey data included individual case histories for environmental factors,comorbidities,disease-specific complaints,impact-related questions,cognitive complaints,health-related quality of life(HRQoL),and sense of coherence(SOC).Results:We observed significant differences between those with and without sporadic occurrence,family history,thyroid disorder,and migraine-associated complaints.Family history explained 20%of variability in patient complaints.Patients with a family history of MD whose disease started at younger age experienced balance problems,more severe vertigo spells,more severe vestibular drop attacks(VDA),and less nausea,although they had good SOC.Thyroid disorder explained 14%of variability in patient complaints.MD patients with a thyroid disorder comorbidity suffered more often from constant dizziness,balance problems,greater impact of hearing problems,cognitive complaints,and poor HRQoL.Migraine explained 12%of variability in patients’complaints and was associated with poor SOC and cognitive balance problems.MD patients with both thyroid disorder and migraine used antidepressants more often than other groups.Logistic regression analysis showed comorbidities of ischemic brain disorder(among 7.1%),kidney insufficiency(among 1.2%),and diabetes(among 7.3%)had statistically significant but restricted association with balance and gait problems,VDA,and reduced HRQoL.Conclusions:Family history of MD and thyroid disorder or migraine comorbidities in MD influence the complaint pattern and partially explain complex symptom profiles,including symptoms of cognitive problems.Confounders play a minimal role in complaint profile and impact of MD whereas comorbidities influence the complaint structure and partly explain the complex symptom profile in MD.
基金National Natural Science Foundation of China (Grant No. 30271538)985 program,Ministry of Education of China
文摘To discover new lead compounds for M1 agonists. Ten typical M1 agonists were superimposed to build a M1 agonists 3D-pharmacophore model using distance-comparisons （DISCO） method without the previous knowledge of the three-dimensional structure of M1 receptor. Virtual screening strategy was used to analyze the Available Chemicals Directory-Screening Compounds （ACD-SC） to identify possible new hits. Twenty-two compounds which fit the pharmacophore model well and are not similar with known M1 agonists were purchased in order to evaluate their M1 receptor agonist activity. One of them shows M1 receptor agonist activity with EC50 of 4.90 μmol/L and maximum response. Multiple of 10.0 which shows it worthy of further study as a new lead compound for M1 agonists.
基金supported by Midstream Research Program for UniversitiesHong Kong Special Administrative Region,China,No.MRP-092-17X。
文摘Lycium barbarum(LB)is a traditional Chinese medicine that has been demonstrated to exhibit a wide variety of biological functions,such as antioxidation,neuroprotection,and immune modulation.One of the main mechanisms of Alzheimer’s disease is that microglia activated by amyloid beta(Aβ)transform from the resting state to an M1 state and release pro-inflammatory cytokines to the surrounding environment.In the present study,immortalized microglial cells were pretreated with L.barbarum extract for 1 hour and then treated with oligomeric Aβfor 23 hours.The results showed that LB extract significantly increased the survival of oligomeric Aβ-induced microglial cells,downregulated the expression of M1 pro-inflammatory markers(inducible nitric oxide synthase,tumor necrosis factorα,interleukin-6,and interleukin-1β),and upregulated the expression of M2 anti-inflammatory markers(arginase-1,chitinase-like protein 3,and interleukin-4).LB extract also inhibited the oligomeric Aβ-induced secretion of tumor necrosis factorα,interleukin-6,and interleukin-1βin microglial cells.The results of in vitro cytological experiments suggest that,in microglial cells,LB extract can inhibit oligomeric Aβ-induced M1 polarization and concomitant inflammatory reactions,and promote M2 polarization.
基金supported by ANID-FONDECYT 1170033(to JSA)ANID-STINT-CONICYT CS2018-7940(to JSA,IN,JI,MV)Swedish Research Council grant 2015-04222 to BM.
文摘Astrocytes protect neurons by modulating neuronal function and survival.Astrocytes support neurons in several ways.They provide energy through the astrocyte-neuron lactate shuttle,protect neurons from excitotoxicity,and internalize neuronal lipid droplets to degrade fatty acids for neuronal metabolic and synaptic support,as well as by their high capacity for glutamate uptake and the conversion of glutamate to glutamine.A recent reported astrocyte system for protection of dopamine neurons against the neurotoxic products of dopamine,such as aminochrome and other o-quinones,were generated under neuromelanin synthesis by oxidizing dopamine catechol structure.Astrocytes secrete glutathione transferase M2-2 through exosomes that transport this enzyme into dopaminergic neurons to protect these neurons against aminochrome neurotoxicity.The role of this new astrocyte protective mechanism in Parkinson´s disease is discussed.
