AIM: To examine the expression of SphK1, an oncogenic kinase that produces sphingosine 1-phosphate (S1P), and its correlation with the expression of LPAR2, a major lysophosphatidic acid (LPA) receptor overexpressed in...AIM: To examine the expression of SphK1, an oncogenic kinase that produces sphingosine 1-phosphate (S1P), and its correlation with the expression of LPAR2, a major lysophosphatidic acid (LPA) receptor overexpressed in various cancers, in human colorectal cancer.METHODS: Real-time reverse-transcription polymerase chain reaction was used to measure the mRNA expression of SphK1, LPAR2, and the three major S1P receptors in 27 colorectal cancer samples and corresponding normal tissue samples. We also examined the correlation between the expression of SphK1 and LPAR2.RESULTS: Colorectal cancer tissue in 22 of 27 patients had higher levels of SphK1 mRNA than in normal tissue. In two-thirds of the samples, SphK1 mRNA expression was more than two-fold higher than in normal tissue. Consistent with previous reports, LPAR2 mRNA expression in 20 of 27 colorectal cancer tissue samples was higher compared to normal tissue samples. Expression profiles of all three major S1P receptors, S1PR1, S1PR2, and S1PR3, varied without any trend, with no significant difference in expression between cancer and normal tissues. A highly significant positive correlation was found between SphK1 and LPAR2 expression [Pearson’s correlation coefficient (r) = 0.784 and P < 0.01]. The mRNA levels of SphK1 and LPAR2 did not correlate with TNM stage.CONCLUSION: Our findings suggest that S1P and LPA may play important roles in the development of colorectal cancer via the upregulation of SphK1 and LPAR2, both of which could serve as new therapeutic targets in the treatment of colorectal cancer.展开更多
AIM： To examine whether lysophosphatidic acid （LPA） induces phosphorylation of c-Met and epidermal growth factor receptor （EGFR）, both of which have been proposed as prognostic markers of colorectal cancer, and w...AIM： To examine whether lysophosphatidic acid （LPA） induces phosphorylation of c-Met and epidermal growth factor receptor （EGFR）, both of which have been proposed as prognostic markers of colorectal cancer, and whether LPA induces cyclooxygenase-2 （COX-2） expression in human colon cancer cells. METHODS： Using a human colon cancer cell line, LoVo cells, we performed immunoprecipitation analysis, followed by Western blot analysis. We also examined whether LPA induced COX-2 expression, by Western blot analysis. RESULTS： Immunoprecipitation analysis revealed that 10 μmol/L LPA induced tyrosine phosphorylation of c-Met and EGFR in LoVo cells within a few minutes. We found that c-Met tyrosine phosphorylation induced by LPA was not attenuated by pertussis toxin or a matrix metalloproteinase inhibitor, in marked contrast to the results for EGFR. In addition, 0.2-40 IJmol/L LPA induced COX-2 expression in a dose-dependent manner. CONCLUSION： Our results suggest that LPA acts upstream of various receptor tyrosine kinases （RTKs） and COX-2, and thus may act as a potent stimulator of colorectal cancer. 2005 The WJG Press and Elsevier Inc. All rights reserved.展开更多
Objective The present study aimed to explore the role of P2Y1 receptor in glial fibrillary acidic protein （GFAP） production and glial cell line-derived neurotrophic factor （GDNF） secretion of astrocytes under isch...Objective The present study aimed to explore the role of P2Y1 receptor in glial fibrillary acidic protein （GFAP） production and glial cell line-derived neurotrophic factor （GDNF） secretion of astrocytes under ischemic insult and the related signaling pathways. Methods Using transient right middle cerebral artery occlusion （tMCAO） and oxygen-glucose-serum deprivation for 2 h as the model of ischemic injury in vivo and in vitro, immunofluorescence, quantitative real-time reverse transcription-polymerase chain reaction （RT-PCR）, Western blotting, enzyme linked immunosorbent assay （ELISA） were used to investigate location of P2Y1 receptor and GDNF, the expression of GFAP and GDNF, and the changes of signaling molecules. Results Blockage of P2Y1 receptor with the selective antagonist N^6-methyl-2′-deoxyadenosine 3′,5′-bisphosphate diammonium （MRS2179） reduced GFAP production and increased GDNF production in the antagonist group as compared with simple ischemic group both in vivo and in vitro. Oxygen-glucose-serum deprivation and blockage of P2Y1 receptor caused elevation of phosphorylated Akt and cAMP response element binding protein （CREB）, and reduction of phosphorylated Janus kinase2 （JAK2） and signal transducer and activator of transcription3 （STAT3, Ser727）. After blockage of P2Y1 receptor and deprivation of oxygen-glucose-serum, AG490 （inhibitor of JAK2） reduced phosphorylation of STAT3 （Ser727） as well as expression of GFAP; LY294002, an inhibitor of phosphatidylinositol 3-kinase （PI3-K）, decreased phosphorylation of Akt and CREB; the inhibitor of mitogen-activated protein kinase kinase 1/2 （MEK 1/2） U0126, an important molecule of Ras/extracellular signal- regulated kinase （ERK） signaling pathway, decreased the phosphorylation of JAK2, STAT3 （Ser727）, Akt and CREB. Conclusion These results suggest that P2Y1 receptor plays a role in the production of GFAP and GDNF in astrocytes under transient ischemic condition and the related signaling pathways may be JAK2/STAT3 and PI3-K/Akt/CREB, respectively, and that crosstalk probably exists between them.展开更多
The transient receptor potential melastatin 2 is a calcium-permeable cation channel member of the TRP family. Also known as an oxidative stress-activated channel, the transient receptor potential melastatin 2 gating m...The transient receptor potential melastatin 2 is a calcium-permeable cation channel member of the TRP family. Also known as an oxidative stress-activated channel, the transient receptor potential melastatin 2 gating mechanism is dependent on reactive oxygen species. In pathological conditions, transient receptor potential melastatin 2 is overactivated, leading to a Ca~(2+) influx that alters cell homeostasis and promotes cell death. The role of transient receptor potential melastatin 2 in neurodegenerative diseases, including Alzheimer's disease and ischemia, has already been described and reviewed. However, data on transient receptor potential melastatin 2 involvement in Parkinson's disease pathology has emerged only in recent years and the issue lacks review studies that focus specifically on this topic. The present review aims to elucidate the role of the transient receptor potential melastatin 2 channel in Parkinson's disease by reviewing, summarizing, and discussing the in vitro, in vivo, and human studies published until August 2022. Here we describe fourteen studies that evaluated the transient receptor potential melastatin 2 channel in Parkinson's disease. The Parkinson's disease model used, transient receptor potential melastatin 2 antagonist and genetic approaches, and the main outcomes reported were discussed. The studies described transient receptor potential melastatin 2 activation and enhanced expression in different Parkinson's disease models. They also evidenced protective and restorative effects when using transient receptor potential melastatin 2 antagonists, knockout, or silencing. This review provides a literature overview and suggests where there is a need for more research. As a perspective point, this review shows evidence that supports transient receptor potential melastatin 2 as a pharmacological target for Parkinson's disease in the future.展开更多
Breast cancer brain metastasis(BCBrM)is a crucial and hard area of research which guarantees an urgent need to understand the underlying molecular mechanisms.A recent study by Li et al.[1]published in Military Medical...Breast cancer brain metastasis(BCBrM)is a crucial and hard area of research which guarantees an urgent need to understand the underlying molecular mechanisms.A recent study by Li et al.[1]published in Military Medical Research investigated the role of retinoic acid receptor responder 2(RARRES2)in regulating lipid metabolism in BCBrM,highlighting the clinical relevance of alterations in lipid metabolites,such as phosphatidylcholine(PC)and triacylglycerols(TAGs),by RARRES2 through the modulation of phosphatase and tensin homologue(PTEN)-mammalian target of rapamycin(mTOR)-sterol regulatory element-binding protein 1(SREBP1)signaling pathway.This commentary aims to elaborate on the key findings and their relevance to the field.展开更多
Objective To study the effect of chronic noise exposure on expression of N-methyI-D-aspartic acid receptor 2B （NR2B） and tau phosphorylation in hippocampus of rats. Methods Twenty-four male SD rats were divided in c...Objective To study the effect of chronic noise exposure on expression of N-methyI-D-aspartic acid receptor 2B （NR2B） and tau phosphorylation in hippocampus of rats. Methods Twenty-four male SD rats were divided in control group and chronic noise exposure group. NR2B expression and tau phosphorylation in hippocampus of rats were detected after chronic noise exposure （100 dB SPL white noise, 4 h/dx30d） and their mechanisms underlying neuronal apoptosis in hippocampus of rats with TUNEL staining. Results The NR2B expression decreased significantly after chronic noise exposure which resulted in tau hyperphosphorylation and neural apoptosis in hippocampus of rats. Immunohistochemistry showed that the tau hyperphosphorylation was most prominent in dentate gyrus （DG） and CA1 region of rat hippocampus. Conclusion The abnormality of neurotransmitter system, especially Glu and NR2B containing NMDA receptor, and tau hyperphosphorylation in hippocampus of rats, may play a role in chronic noise-induced neural apoptosis and cognition impairment.展开更多
BACKGROUND Colorectal cancer(CRC)is a worldwide problem,which has been associated with changes in diet and lifestyle pattern.As a result of colonic fermentation of dietary fibres,short chain free fatty acids are gener...BACKGROUND Colorectal cancer(CRC)is a worldwide problem,which has been associated with changes in diet and lifestyle pattern.As a result of colonic fermentation of dietary fibres,short chain free fatty acids are generated which activate free fatty acid receptors(FFAR)2 and 3.FFAR2 and FFAR3 genes are abundantly expressed in colonic epithelium and play an important role in the metabolic homeostasis of colonic epithelial cells.Earlier studies point to the involvement of FFAR2 in colorectal carcinogenesis.AIM To understand the role of short chain FFARs in CRC.METHODS Transcriptome analysis console software was used to analyse microarray data from CRC patients and cell lines.We employed short-hairpin RNA mediated down regulation of FFAR2 and FFAR3 genes,which was validated using quantitative real time polymerase chain reaction.Assays for glucose uptake and cyclic adenosine monophosphate(cAMP)generation was done along with immunofluorescence studies to study the effects of FFAR2/FFAR3 knockdown.For measuring cell proliferation,we employed real time electrical impedancebased assay available from xCELLigence.RESULTS Microarray data analysis of CRC patient samples showed a significant down regulation of FFAR2 gene expression.This prompted us to study the FFAR2 in CRC.Since,FFAR3 shares significant structural and functional homology with FFAR2,we knocked down both these receptors in CRC cell line HCT 116.These modified cell lines exhibited higher proliferation rate and were found to have increased glucose uptake as well as increased level of glucose transporter 1.Since,FFAR2 and FFAR3 signal through G protein subunit(Gαi),knockdown of these receptors was associated with increased cAMP.Inhibition of protein kinase A(PKA)did not alter the growth and proliferation of these cells indicating a mechanism independent of cAMP/PKA pathway.CONCLUSION Our results suggest role of FFAR2/FFAR3 genes in increased proliferation of colon cancer cells via enhanced glucose uptake and exclude the role of PKA mediated cAMP signalling.Alternate pathways could be involved that would ultimately result in increased cell proliferation as a result of down regulated FFAR2/FFAR3 genes.This study paves the way to understand the mechanism of action of short chain FFARs in CRC.展开更多
Objective: The molecular mechanism of prostate cancer is poorly understood. The aim of the study was to investigate the prevalence and prognostic value of promoter hypermethylation of retinoic acid receptor beta (RARB...Objective: The molecular mechanism of prostate cancer is poorly understood. The aim of the study was to investigate the prevalence and prognostic value of promoter hypermethylation of retinoic acid receptor beta (RARB) and p16 among benign prostatic hyperplasia (BPH) and prostate cancer patients. Methods: In this case-control study, 63 patients were included in three groups; 21 with BPH as the control group, 21 with prostate cancer and good prognostic factors (based on prostate-specific antigen, Gleason score and stage) as good prognosis group, and 21 with prostate cancer and poor prognostic features as poor prognosis group. The prostate biopsy specimen of each individual was examined for hypermethylation of RARB and p16 promoters by methylation specific PCR (MSPCR). Results: Seven (33.3%) patients with good prognosis and 15 (71.4%) patients with poor prognosis were positive for RARB methylation, which were significantly higher than controls (P <0.0001). p16 promoter methylation was shown in 19.0% and 47.6% patients with good and poor prognosis, respectively. The RARB and p16 promoter methylation in the poor prognosis group was significantly higher than that in the good prognosis group (P =0.02 for RARB and P<0.0001 for p16). Conclusion: Hypermethylation of RARB and p16 promoters may predict prognosis in prostate cancer.展开更多
Spinal dorsal horn N-Methyl-D-aspartic acid receptor 2B （NR2B） overexpression plays an important role in the production and maintenance of neuropathic pain. Because small interfering RNA （siRNA） can inhibit NR2B e...Spinal dorsal horn N-Methyl-D-aspartic acid receptor 2B （NR2B） overexpression plays an important role in the production and maintenance of neuropathic pain. Because small interfering RNA （siRNA） can inhibit NR2B expression, siRNA may provide a novel approach to treat neuropathic pain and possibly nerve injury. However, an efficient and safe vector for NR2B siRNA has not been discovered. This study shows that a water soluble lipopolymer （WSLP） comprised of low molecular weight polyethyleneimine （PEI） and cholesterol can deliver siRNA targeting NR2B for the treatment of neuropathic pain. Results show that intrathecal injection of WSLP/siRNA complexes for 3 days inhibit NR2B gene expression with reductions in mRNA and protein levels by 59% and 54%, respectively, compared with control rats （P 〈 0.01）. Injection of WSLP complexed with scrambled siRNA, or PEI with siRNA did not show this inhibitory effect. Moreover, injection of WSLP/siRNA complexes significantly relieved neuropathic pain at 3, 7, 12, and 21 days, while injection of WSLP with scrambled siRNA or PEI with siRNA did not. These results demonstrate that WSLP can efficiently deliver siRNA targeting NR2B in vivo and relieve neuropathic pain.展开更多
The γ-aminobutyric acid neurotransmitter in the spinal cord dorsal horn plays an important role in pain modulation through primary afferent-mediated presynaptic inhibition. The weakening of γ-aminobutyric acid-media...The γ-aminobutyric acid neurotransmitter in the spinal cord dorsal horn plays an important role in pain modulation through primary afferent-mediated presynaptic inhibition. The weakening of γ-aminobutyric acid-mediated presynaptic inhibition may be an important cause of neuropathic pain. γ-aminobutyric acid-mediated presynaptic inhibition is related to the current strength of γ-aminobutyric acid A receptor activation. In view of this, the whole-cell patch-clamp technique was used here to record the change in muscimol activated current of dorsal root ganglion neurons in a chronic constriction injury model. Results found that damage in rat dorsal root ganglion neurons following application of muscimol caused concentration-dependent activation of current, and compared with the sham group, its current strength and γ-aminobutyric acid A receptor protein expression decreased. Immunofluorescence revealed that γ-aminobutyric acid type A receptor α2 subunit protein expression decreased and was most obvious at 12 and 15 days after modeling. Our experimental findings confirmed that the y-aminobutyric acid type A receptor α2 subunit in the chronic constriction injury model rat dorsal root ganglion was downregulated, which may be one of the reasons for the reduction of injury in dorsal root ganglion neurons following muscimol-activated currents.展开更多
BACKGROUND： Studies have demonstrated that in vitro cultured cortical neurons from embryonic rats can produce spontaneous recurrent epileptiform discharges following transient Mg^2＋-free extracellular solution cultu...BACKGROUND： Studies have demonstrated that in vitro cultured cortical neurons from embryonic rats can produce spontaneous recurrent epileptiform discharges following transient Mg^2＋-free extracellular solution culture. OBJECTIVE： To explore gammaminobutyric acid A receptor （GABAAR）γ 2 subunit expression following Mg^2＋-free-induced seizures in cultured developing neurons. DESIGN, TIME AND SETTING： Cellular and molecular biology. The in vitro experiment was performed at the Department of Pediatrics, Second Xiangya Hospital of Central Southern University between January 2007 and February 2008. MATERIALS： Cortical neurons of Wistar rats on gestational days 16-17 were used. Normal extracellular solution （pH 7.3） consisted of NaCl 145 mmol/L, KCl 2.5 mmol/L, HEPES l0 mmol/L, MgC12 1 mmol/L, CaC12 2 mmol/L, glucose 10 mmol/L, and glycine 0.01 mmol/L. In addition, there was no MgCl2 in the Mg^2＋-free extracellular solution. METHODS： Cortical neurons cultured for 6 days were exposed to normal extracellular solution （control group） and Mg^2＋-free media （Mg^2＋-free group） respectively for 3 hours, followed by continuous culture in DMEM solution. MAIN OUTCOME MEASURES： On days 1, 7 and 12 after Mg^2＋-free treatment, real-time RT-PCR, immunochemistry, and flow cytometry were used to detect GABAAR 3/2 subunit expression. RESULTS： Compared with the control group, GABAAR γ-positive cells decreased significantly on days 1 and 7 after Mg^2＋-free treatment （P 〈 0.01）, but significantly increased on day 12 （P 〈 0.01 ）. GABAAR γ2 subunit mRNA expression decreased significantly at 7 days Mg^2＋-free treatment when measured by real-time RT-PCR compared with the control group （P 〈 0.05）. CONCLUSION： GABAAR γ2 subunit expression is modified following Mg-free-induced seizures in cultured developing neurons. This indicates the possibility that abnormal GABAA receptor expression might play an important role in development of neuronal injury.展开更多
Estrogen affects the generation and transmission of neuropathic pain,but the specific regulatory mechanism is still unclear.Activation of the N-methyl-D-aspartate acid receptor 1（NMDAR1） plays an important role in t...Estrogen affects the generation and transmission of neuropathic pain,but the specific regulatory mechanism is still unclear.Activation of the N-methyl-D-aspartate acid receptor 1（NMDAR1） plays an important role in the production and maintenance of hyperalgesia and allodynia.The present study was conducted to determine whether a relationship exists between estrogen and NMDAR1 in peripheral nerve pain.A chronic sciatic nerve constriction injury model of chronic neuropathic pain was established in rats.These rats were then subcutaneously injected with 17β-estradiol,the NMDAR1 antagonist D（-）-2-amino-5-phosphonopentanoic acid（AP-5）,or both once daily for 15 days.Compared with injured drug na？ve rats,rats with chronic sciatic nerve injury that were administered estradiol showed a lower paw withdrawal mechanical threshold and a shorter paw withdrawal thermal latency,indicating increased sensitivity to mechanical and thermal pain.Estrogen administration was also associated with increased expression of NMDAR1 immunoreactivity（as assessed by immunohistochemistry） and protein（as determined by western blot assay） in spinal dorsal root ganglia.This 17β-estradiol-induced increase in NMDAR1 expression was blocked by co-administration with AP-5,whereas AP-5 alone did not affect NMDAR1 expression.These results suggest that 17β-estradiol administration significantly reduced mechanical and thermal pain thresholds in rats with chronic constriction of the sciatic nerve,and that the mechanism for this increased sensitivity may be related to the upregulation of NMDAR1 expression in dorsal root ganglia.展开更多
P2X4 and P2X7 receptors play an important role in neuropathic pain after spinal cord injury. Regulation of P2X4 and P2X7 receptors can obviously reduce pain hypersensitivity after injury. To investigate the role of ne...P2X4 and P2X7 receptors play an important role in neuropathic pain after spinal cord injury. Regulation of P2X4 and P2X7 receptors can obviously reduce pain hypersensitivity after injury. To investigate the role of neural stem cell transplantation on P2X receptor-mediated neuropathic pain and explore related mechanisms, a rat model of spinal cord injury was prepared using the free-falling heavy body method with spinal cord segment 10 as the center. Neural stem cells were injected into the injured spinal cord segment using a micro-syringe. Expression levels of P2X4 and P2X7 receptors, neurofilament protein, and glial fibrillary acidic protein were determined by immunohistochemistry and western blot assay. In addition, sensory function was quantitatively assessed by current perception threshold. The Basso-Beattie-Bresnahan locomotor rating scale was used to assess neuropathological pain. The results showed that 4 weeks after neural stem cell transplantation, expression of neurofilament protein in the injured segment was markedly increased, while expression of glial fibrillary acidic protein and P2X4 and P2X7 receptors was decreased. At this time point, motor and sensory functions of rats were obviously improved, and neuropathic pain was alleviated. These findings demonstrated that neural stem cell transplantation reduced overexpression of P2X4 and P2X7 receptors, activated locomotor and sensory function reconstruction, and played an important role in neuropathic pain regulation after spinal cord injury. Therefore, neural stem cell transplantation is one potential option for relieving neuropathic pain mediated by P2X receptors.展开更多
This study examined the effects of ω-3 polyunsaturated fatty acid（ω-3PUFA） on the expression of toll-like receptor 2（TLR2）,toll-like receptor 4（TLR4） and some related inflammatory factors in peripheral blood m...This study examined the effects of ω-3 polyunsaturated fatty acid（ω-3PUFA） on the expression of toll-like receptor 2（TLR2）,toll-like receptor 4（TLR4） and some related inflammatory factors in peripheral blood mononuclear cells（PBMCs） of patients with early-stage severe multiple trauma.Thirty-two patients who were admitted to the Department of Traumatic Surgery,Tongji Hospital（Wuhan,China） between May 2010 and November 2010,and diagnosed as having severe multiple trauma with a injury severity score（ISS） no less than 16,were enrolled in the study and divided into two groups at random（n=16 in each）：ω-3PUFA group and control group in which routine parenteral nutrition supplemented with ω-3PUFA or not was administered to the patients in two groups for consecutive 7 days.Peripheral blood from these patients was collected within 2 h of admission（day 0）,and 1,3,5 and 7 days after the nutritional support.PBMCs were isolated and used for detection of the mRNA and protein expression of TLR2 and TLR4 by using real-time PCR and flow cytometry respectively,the levels of NF-κB by quantum dots-based immunofluorescence assay,the levels of TNF-α,IL-2,IL-6 and COX-2 by ELISA,respectively.The results showed that the mRNA and protein expression of TLR2 and TLR4 in PBMCs was significantly lower in ω-3PUFA group than in control group 5 and 7 days after nutrition support（both P0.05）.The levels of TNF-α,IL-2,IL-6 and COX-2 were found to be substantially decreased in PBMCs in ω-3PUFA group as compared with control group at 5th and 7th day（P0.05 for all）.It was concluded that ω-3PUFA can remarkably decrease the expression of TLR2,TLR4 and some related inflammatory factors in NF-κB signaling pathway in PBMCs of patients with severe multiple trauma,which suggests that ω-3PUFA may suppress the excessive inflammatory response meditated by the TLRs/NF-κB signaling pathway.展开更多
Type 1 diabetes can be classified into immune-mediated diabetes (type 1A) and idiopathic diabetes, which lacks immunological evidence for beta cell autoimmunity (type 1B). Type 1A diabetes is characterized by the pres...Type 1 diabetes can be classified into immune-mediated diabetes (type 1A) and idiopathic diabetes, which lacks immunological evidence for beta cell autoimmunity (type 1B). Type 1A diabetes is characterized by the presence of the anti-glutamic acid decarboxylase antibody (anti-GADab). Fulminant type 1 diabetes is classified as type 1B diabetes, and characterized by the absence of anti-GADab, flu-like symptoms, and elevated serum exocrine pancreatic enzymes. We report a type 1 diabetic patient who showed flu-like symptoms, elevated serum exocrine pancreatic enzymes, and an extremely high-titer of anti-GADab, manifesting the characteristics of both type 1A and fulminant type 1 diabetes.展开更多
基金Supported by Grant 2010 from Tokyo MetropolisJapan
文摘AIM: To examine the expression of SphK1, an oncogenic kinase that produces sphingosine 1-phosphate (S1P), and its correlation with the expression of LPAR2, a major lysophosphatidic acid (LPA) receptor overexpressed in various cancers, in human colorectal cancer.METHODS: Real-time reverse-transcription polymerase chain reaction was used to measure the mRNA expression of SphK1, LPAR2, and the three major S1P receptors in 27 colorectal cancer samples and corresponding normal tissue samples. We also examined the correlation between the expression of SphK1 and LPAR2.RESULTS: Colorectal cancer tissue in 22 of 27 patients had higher levels of SphK1 mRNA than in normal tissue. In two-thirds of the samples, SphK1 mRNA expression was more than two-fold higher than in normal tissue. Consistent with previous reports, LPAR2 mRNA expression in 20 of 27 colorectal cancer tissue samples was higher compared to normal tissue samples. Expression profiles of all three major S1P receptors, S1PR1, S1PR2, and S1PR3, varied without any trend, with no significant difference in expression between cancer and normal tissues. A highly significant positive correlation was found between SphK1 and LPAR2 expression [Pearson’s correlation coefficient (r) = 0.784 and P < 0.01]. The mRNA levels of SphK1 and LPAR2 did not correlate with TNM stage.CONCLUSION: Our findings suggest that S1P and LPA may play important roles in the development of colorectal cancer via the upregulation of SphK1 and LPAR2, both of which could serve as new therapeutic targets in the treatment of colorectal cancer.
基金Supported by a Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan and a grant from the Ministry of Health, Labour and Welfare of Japan
文摘AIM： To examine whether lysophosphatidic acid （LPA） induces phosphorylation of c-Met and epidermal growth factor receptor （EGFR）, both of which have been proposed as prognostic markers of colorectal cancer, and whether LPA induces cyclooxygenase-2 （COX-2） expression in human colon cancer cells. METHODS： Using a human colon cancer cell line, LoVo cells, we performed immunoprecipitation analysis, followed by Western blot analysis. We also examined whether LPA induced COX-2 expression, by Western blot analysis. RESULTS： Immunoprecipitation analysis revealed that 10 μmol/L LPA induced tyrosine phosphorylation of c-Met and EGFR in LoVo cells within a few minutes. We found that c-Met tyrosine phosphorylation induced by LPA was not attenuated by pertussis toxin or a matrix metalloproteinase inhibitor, in marked contrast to the results for EGFR. In addition, 0.2-40 IJmol/L LPA induced COX-2 expression in a dose-dependent manner. CONCLUSION： Our results suggest that LPA acts upstream of various receptor tyrosine kinases （RTKs） and COX-2, and thus may act as a potent stimulator of colorectal cancer. 2005 The WJG Press and Elsevier Inc. All rights reserved.
基金the National Natural Science Foundation of China (No. 30500189)
文摘Objective The present study aimed to explore the role of P2Y1 receptor in glial fibrillary acidic protein （GFAP） production and glial cell line-derived neurotrophic factor （GDNF） secretion of astrocytes under ischemic insult and the related signaling pathways. Methods Using transient right middle cerebral artery occlusion （tMCAO） and oxygen-glucose-serum deprivation for 2 h as the model of ischemic injury in vivo and in vitro, immunofluorescence, quantitative real-time reverse transcription-polymerase chain reaction （RT-PCR）, Western blotting, enzyme linked immunosorbent assay （ELISA） were used to investigate location of P2Y1 receptor and GDNF, the expression of GFAP and GDNF, and the changes of signaling molecules. Results Blockage of P2Y1 receptor with the selective antagonist N^6-methyl-2′-deoxyadenosine 3′,5′-bisphosphate diammonium （MRS2179） reduced GFAP production and increased GDNF production in the antagonist group as compared with simple ischemic group both in vivo and in vitro. Oxygen-glucose-serum deprivation and blockage of P2Y1 receptor caused elevation of phosphorylated Akt and cAMP response element binding protein （CREB）, and reduction of phosphorylated Janus kinase2 （JAK2） and signal transducer and activator of transcription3 （STAT3, Ser727）. After blockage of P2Y1 receptor and deprivation of oxygen-glucose-serum, AG490 （inhibitor of JAK2） reduced phosphorylation of STAT3 （Ser727） as well as expression of GFAP; LY294002, an inhibitor of phosphatidylinositol 3-kinase （PI3-K）, decreased phosphorylation of Akt and CREB; the inhibitor of mitogen-activated protein kinase kinase 1/2 （MEK 1/2） U0126, an important molecule of Ras/extracellular signal- regulated kinase （ERK） signaling pathway, decreased the phosphorylation of JAK2, STAT3 （Ser727）, Akt and CREB. Conclusion These results suggest that P2Y1 receptor plays a role in the production of GFAP and GDNF in astrocytes under transient ischemic condition and the related signaling pathways may be JAK2/STAT3 and PI3-K/Akt/CREB, respectively, and that crosstalk probably exists between them.
基金funded by Coordination for the Improvement of Higher Education Personnel (CAPES,Brazil-Finance Code 001,to LRB)the S?o Paulo Research Foundation(FAPESP,Brazil,project#2018/07366-4)+1 种基金The National Council for Scientific and Technological Development (CNPq,Brazil,project#303006/2018-8,to LRB)a PhD fellowship from FAPESP under Grant Agreement No 2020/02109-3。
文摘The transient receptor potential melastatin 2 is a calcium-permeable cation channel member of the TRP family. Also known as an oxidative stress-activated channel, the transient receptor potential melastatin 2 gating mechanism is dependent on reactive oxygen species. In pathological conditions, transient receptor potential melastatin 2 is overactivated, leading to a Ca~(2+) influx that alters cell homeostasis and promotes cell death. The role of transient receptor potential melastatin 2 in neurodegenerative diseases, including Alzheimer's disease and ischemia, has already been described and reviewed. However, data on transient receptor potential melastatin 2 involvement in Parkinson's disease pathology has emerged only in recent years and the issue lacks review studies that focus specifically on this topic. The present review aims to elucidate the role of the transient receptor potential melastatin 2 channel in Parkinson's disease by reviewing, summarizing, and discussing the in vitro, in vivo, and human studies published until August 2022. Here we describe fourteen studies that evaluated the transient receptor potential melastatin 2 channel in Parkinson's disease. The Parkinson's disease model used, transient receptor potential melastatin 2 antagonist and genetic approaches, and the main outcomes reported were discussed. The studies described transient receptor potential melastatin 2 activation and enhanced expression in different Parkinson's disease models. They also evidenced protective and restorative effects when using transient receptor potential melastatin 2 antagonists, knockout, or silencing. This review provides a literature overview and suggests where there is a need for more research. As a perspective point, this review shows evidence that supports transient receptor potential melastatin 2 as a pharmacological target for Parkinson's disease in the future.
文摘Breast cancer brain metastasis(BCBrM)is a crucial and hard area of research which guarantees an urgent need to understand the underlying molecular mechanisms.A recent study by Li et al.[1]published in Military Medical Research investigated the role of retinoic acid receptor responder 2(RARRES2)in regulating lipid metabolism in BCBrM,highlighting the clinical relevance of alterations in lipid metabolites,such as phosphatidylcholine(PC)and triacylglycerols(TAGs),by RARRES2 through the modulation of phosphatase and tensin homologue(PTEN)-mammalian target of rapamycin(mTOR)-sterol regulatory element-binding protein 1(SREBP1)signaling pathway.This commentary aims to elaborate on the key findings and their relevance to the field.
基金supported by a grant from the National Natural Science Foundation of China (No. 81001237)
文摘Objective To study the effect of chronic noise exposure on expression of N-methyI-D-aspartic acid receptor 2B （NR2B） and tau phosphorylation in hippocampus of rats. Methods Twenty-four male SD rats were divided in control group and chronic noise exposure group. NR2B expression and tau phosphorylation in hippocampus of rats were detected after chronic noise exposure （100 dB SPL white noise, 4 h/dx30d） and their mechanisms underlying neuronal apoptosis in hippocampus of rats with TUNEL staining. Results The NR2B expression decreased significantly after chronic noise exposure which resulted in tau hyperphosphorylation and neural apoptosis in hippocampus of rats. Immunohistochemistry showed that the tau hyperphosphorylation was most prominent in dentate gyrus （DG） and CA1 region of rat hippocampus. Conclusion The abnormality of neurotransmitter system, especially Glu and NR2B containing NMDA receptor, and tau hyperphosphorylation in hippocampus of rats, may play a role in chronic noise-induced neural apoptosis and cognition impairment.
文摘BACKGROUND Colorectal cancer(CRC)is a worldwide problem,which has been associated with changes in diet and lifestyle pattern.As a result of colonic fermentation of dietary fibres,short chain free fatty acids are generated which activate free fatty acid receptors(FFAR)2 and 3.FFAR2 and FFAR3 genes are abundantly expressed in colonic epithelium and play an important role in the metabolic homeostasis of colonic epithelial cells.Earlier studies point to the involvement of FFAR2 in colorectal carcinogenesis.AIM To understand the role of short chain FFARs in CRC.METHODS Transcriptome analysis console software was used to analyse microarray data from CRC patients and cell lines.We employed short-hairpin RNA mediated down regulation of FFAR2 and FFAR3 genes,which was validated using quantitative real time polymerase chain reaction.Assays for glucose uptake and cyclic adenosine monophosphate(cAMP)generation was done along with immunofluorescence studies to study the effects of FFAR2/FFAR3 knockdown.For measuring cell proliferation,we employed real time electrical impedancebased assay available from xCELLigence.RESULTS Microarray data analysis of CRC patient samples showed a significant down regulation of FFAR2 gene expression.This prompted us to study the FFAR2 in CRC.Since,FFAR3 shares significant structural and functional homology with FFAR2,we knocked down both these receptors in CRC cell line HCT 116.These modified cell lines exhibited higher proliferation rate and were found to have increased glucose uptake as well as increased level of glucose transporter 1.Since,FFAR2 and FFAR3 signal through G protein subunit(Gαi),knockdown of these receptors was associated with increased cAMP.Inhibition of protein kinase A(PKA)did not alter the growth and proliferation of these cells indicating a mechanism independent of cAMP/PKA pathway.CONCLUSION Our results suggest role of FFAR2/FFAR3 genes in increased proliferation of colon cancer cells via enhanced glucose uptake and exclude the role of PKA mediated cAMP signalling.Alternate pathways could be involved that would ultimately result in increased cell proliferation as a result of down regulated FFAR2/FFAR3 genes.This study paves the way to understand the mechanism of action of short chain FFARs in CRC.
文摘Objective: The molecular mechanism of prostate cancer is poorly understood. The aim of the study was to investigate the prevalence and prognostic value of promoter hypermethylation of retinoic acid receptor beta (RARB) and p16 among benign prostatic hyperplasia (BPH) and prostate cancer patients. Methods: In this case-control study, 63 patients were included in three groups; 21 with BPH as the control group, 21 with prostate cancer and good prognostic factors (based on prostate-specific antigen, Gleason score and stage) as good prognosis group, and 21 with prostate cancer and poor prognostic features as poor prognosis group. The prostate biopsy specimen of each individual was examined for hypermethylation of RARB and p16 promoters by methylation specific PCR (MSPCR). Results: Seven (33.3%) patients with good prognosis and 15 (71.4%) patients with poor prognosis were positive for RARB methylation, which were significantly higher than controls (P <0.0001). p16 promoter methylation was shown in 19.0% and 47.6% patients with good and poor prognosis, respectively. The RARB and p16 promoter methylation in the poor prognosis group was significantly higher than that in the good prognosis group (P =0.02 for RARB and P<0.0001 for p16). Conclusion: Hypermethylation of RARB and p16 promoters may predict prognosis in prostate cancer.
基金the Natural Science Foundation of Guangdong Province,No.07000059the Science and Technology Development Program of Guangzhou,No.2010Y1-C301the Science and Technology Development Program of Guangdong Province,No.2010B031600123
文摘Spinal dorsal horn N-Methyl-D-aspartic acid receptor 2B （NR2B） overexpression plays an important role in the production and maintenance of neuropathic pain. Because small interfering RNA （siRNA） can inhibit NR2B expression, siRNA may provide a novel approach to treat neuropathic pain and possibly nerve injury. However, an efficient and safe vector for NR2B siRNA has not been discovered. This study shows that a water soluble lipopolymer （WSLP） comprised of low molecular weight polyethyleneimine （PEI） and cholesterol can deliver siRNA targeting NR2B for the treatment of neuropathic pain. Results show that intrathecal injection of WSLP/siRNA complexes for 3 days inhibit NR2B gene expression with reductions in mRNA and protein levels by 59% and 54%, respectively, compared with control rats （P 〈 0.01）. Injection of WSLP complexed with scrambled siRNA, or PEI with siRNA did not show this inhibitory effect. Moreover, injection of WSLP/siRNA complexes significantly relieved neuropathic pain at 3, 7, 12, and 21 days, while injection of WSLP with scrambled siRNA or PEI with siRNA did not. These results demonstrate that WSLP can efficiently deliver siRNA targeting NR2B in vivo and relieve neuropathic pain.
基金supported by the Youth Science and Technology Innovation Special Foundation of Xinjiang Production and Construction Corps, China, No. 2010JC33
文摘The γ-aminobutyric acid neurotransmitter in the spinal cord dorsal horn plays an important role in pain modulation through primary afferent-mediated presynaptic inhibition. The weakening of γ-aminobutyric acid-mediated presynaptic inhibition may be an important cause of neuropathic pain. γ-aminobutyric acid-mediated presynaptic inhibition is related to the current strength of γ-aminobutyric acid A receptor activation. In view of this, the whole-cell patch-clamp technique was used here to record the change in muscimol activated current of dorsal root ganglion neurons in a chronic constriction injury model. Results found that damage in rat dorsal root ganglion neurons following application of muscimol caused concentration-dependent activation of current, and compared with the sham group, its current strength and γ-aminobutyric acid A receptor protein expression decreased. Immunofluorescence revealed that γ-aminobutyric acid type A receptor α2 subunit protein expression decreased and was most obvious at 12 and 15 days after modeling. Our experimental findings confirmed that the y-aminobutyric acid type A receptor α2 subunit in the chronic constriction injury model rat dorsal root ganglion was downregulated, which may be one of the reasons for the reduction of injury in dorsal root ganglion neurons following muscimol-activated currents.
基金the National Natural Science Foundation of China,No.30400483
文摘BACKGROUND： Studies have demonstrated that in vitro cultured cortical neurons from embryonic rats can produce spontaneous recurrent epileptiform discharges following transient Mg^2＋-free extracellular solution culture. OBJECTIVE： To explore gammaminobutyric acid A receptor （GABAAR）γ 2 subunit expression following Mg^2＋-free-induced seizures in cultured developing neurons. DESIGN, TIME AND SETTING： Cellular and molecular biology. The in vitro experiment was performed at the Department of Pediatrics, Second Xiangya Hospital of Central Southern University between January 2007 and February 2008. MATERIALS： Cortical neurons of Wistar rats on gestational days 16-17 were used. Normal extracellular solution （pH 7.3） consisted of NaCl 145 mmol/L, KCl 2.5 mmol/L, HEPES l0 mmol/L, MgC12 1 mmol/L, CaC12 2 mmol/L, glucose 10 mmol/L, and glycine 0.01 mmol/L. In addition, there was no MgCl2 in the Mg^2＋-free extracellular solution. METHODS： Cortical neurons cultured for 6 days were exposed to normal extracellular solution （control group） and Mg^2＋-free media （Mg^2＋-free group） respectively for 3 hours, followed by continuous culture in DMEM solution. MAIN OUTCOME MEASURES： On days 1, 7 and 12 after Mg^2＋-free treatment, real-time RT-PCR, immunochemistry, and flow cytometry were used to detect GABAAR 3/2 subunit expression. RESULTS： Compared with the control group, GABAAR γ-positive cells decreased significantly on days 1 and 7 after Mg^2＋-free treatment （P 〈 0.01）, but significantly increased on day 12 （P 〈 0.01 ）. GABAAR γ2 subunit mRNA expression decreased significantly at 7 days Mg^2＋-free treatment when measured by real-time RT-PCR compared with the control group （P 〈 0.05）. CONCLUSION： GABAAR γ2 subunit expression is modified following Mg-free-induced seizures in cultured developing neurons. This indicates the possibility that abnormal GABAA receptor expression might play an important role in development of neuronal injury.
基金supported by the Youth Shihezi University Applied Basic Research Project of China,No.2015ZRKYQ-LH19
文摘Estrogen affects the generation and transmission of neuropathic pain,but the specific regulatory mechanism is still unclear.Activation of the N-methyl-D-aspartate acid receptor 1（NMDAR1） plays an important role in the production and maintenance of hyperalgesia and allodynia.The present study was conducted to determine whether a relationship exists between estrogen and NMDAR1 in peripheral nerve pain.A chronic sciatic nerve constriction injury model of chronic neuropathic pain was established in rats.These rats were then subcutaneously injected with 17β-estradiol,the NMDAR1 antagonist D（-）-2-amino-5-phosphonopentanoic acid（AP-5）,or both once daily for 15 days.Compared with injured drug na？ve rats,rats with chronic sciatic nerve injury that were administered estradiol showed a lower paw withdrawal mechanical threshold and a shorter paw withdrawal thermal latency,indicating increased sensitivity to mechanical and thermal pain.Estrogen administration was also associated with increased expression of NMDAR1 immunoreactivity（as assessed by immunohistochemistry） and protein（as determined by western blot assay） in spinal dorsal root ganglia.This 17β-estradiol-induced increase in NMDAR1 expression was blocked by co-administration with AP-5,whereas AP-5 alone did not affect NMDAR1 expression.These results suggest that 17β-estradiol administration significantly reduced mechanical and thermal pain thresholds in rats with chronic constriction of the sciatic nerve,and that the mechanism for this increased sensitivity may be related to the upregulation of NMDAR1 expression in dorsal root ganglia.
基金financially supported by the Natural Science Foundation of Shandong Province of China,No.ZR2014HM046(to ZCZ),ZR2015HL113(to XJD),and ZR2014HL101(to XYW)the Science and Technology Development Project of Taian City of China,No.2015NS2183(to XJD)
文摘P2X4 and P2X7 receptors play an important role in neuropathic pain after spinal cord injury. Regulation of P2X4 and P2X7 receptors can obviously reduce pain hypersensitivity after injury. To investigate the role of neural stem cell transplantation on P2X receptor-mediated neuropathic pain and explore related mechanisms, a rat model of spinal cord injury was prepared using the free-falling heavy body method with spinal cord segment 10 as the center. Neural stem cells were injected into the injured spinal cord segment using a micro-syringe. Expression levels of P2X4 and P2X7 receptors, neurofilament protein, and glial fibrillary acidic protein were determined by immunohistochemistry and western blot assay. In addition, sensory function was quantitatively assessed by current perception threshold. The Basso-Beattie-Bresnahan locomotor rating scale was used to assess neuropathological pain. The results showed that 4 weeks after neural stem cell transplantation, expression of neurofilament protein in the injured segment was markedly increased, while expression of glial fibrillary acidic protein and P2X4 and P2X7 receptors was decreased. At this time point, motor and sensory functions of rats were obviously improved, and neuropathic pain was alleviated. These findings demonstrated that neural stem cell transplantation reduced overexpression of P2X4 and P2X7 receptors, activated locomotor and sensory function reconstruction, and played an important role in neuropathic pain regulation after spinal cord injury. Therefore, neural stem cell transplantation is one potential option for relieving neuropathic pain mediated by P2X receptors.
基金supported by a grant from the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry of China (No. 2009-1001)
文摘This study examined the effects of ω-3 polyunsaturated fatty acid（ω-3PUFA） on the expression of toll-like receptor 2（TLR2）,toll-like receptor 4（TLR4） and some related inflammatory factors in peripheral blood mononuclear cells（PBMCs） of patients with early-stage severe multiple trauma.Thirty-two patients who were admitted to the Department of Traumatic Surgery,Tongji Hospital（Wuhan,China） between May 2010 and November 2010,and diagnosed as having severe multiple trauma with a injury severity score（ISS） no less than 16,were enrolled in the study and divided into two groups at random（n=16 in each）：ω-3PUFA group and control group in which routine parenteral nutrition supplemented with ω-3PUFA or not was administered to the patients in two groups for consecutive 7 days.Peripheral blood from these patients was collected within 2 h of admission（day 0）,and 1,3,5 and 7 days after the nutritional support.PBMCs were isolated and used for detection of the mRNA and protein expression of TLR2 and TLR4 by using real-time PCR and flow cytometry respectively,the levels of NF-κB by quantum dots-based immunofluorescence assay,the levels of TNF-α,IL-2,IL-6 and COX-2 by ELISA,respectively.The results showed that the mRNA and protein expression of TLR2 and TLR4 in PBMCs was significantly lower in ω-3PUFA group than in control group 5 and 7 days after nutrition support（both P0.05）.The levels of TNF-α,IL-2,IL-6 and COX-2 were found to be substantially decreased in PBMCs in ω-3PUFA group as compared with control group at 5th and 7th day（P0.05 for all）.It was concluded that ω-3PUFA can remarkably decrease the expression of TLR2,TLR4 and some related inflammatory factors in NF-κB signaling pathway in PBMCs of patients with severe multiple trauma,which suggests that ω-3PUFA may suppress the excessive inflammatory response meditated by the TLRs/NF-κB signaling pathway.
文摘Type 1 diabetes can be classified into immune-mediated diabetes (type 1A) and idiopathic diabetes, which lacks immunological evidence for beta cell autoimmunity (type 1B). Type 1A diabetes is characterized by the presence of the anti-glutamic acid decarboxylase antibody (anti-GADab). Fulminant type 1 diabetes is classified as type 1B diabetes, and characterized by the absence of anti-GADab, flu-like symptoms, and elevated serum exocrine pancreatic enzymes. We report a type 1 diabetic patient who showed flu-like symptoms, elevated serum exocrine pancreatic enzymes, and an extremely high-titer of anti-GADab, manifesting the characteristics of both type 1A and fulminant type 1 diabetes.
