Genome wide association studies have associated single nucleotide polymorphisms within the gene locus encoding protein tyrosine phosphatase non-receptor type 2(PTPN2) with the onset of inflammatory bowel disease(IBD) ...Genome wide association studies have associated single nucleotide polymorphisms within the gene locus encoding protein tyrosine phosphatase non-receptor type 2(PTPN2) with the onset of inflammatory bowel disease(IBD) and other inflammatory disorders. Expression of PTPN2 is enhanced in actively inflamed intestinal tissue featuring a marked up-regulation in intestinal epithelial cells. PTPN2 deficient mice suffer from severe intestinal and systemic inflammation and display aberrant innate and adaptive immune responses. In particular, PTPN2 is involved in the regulation of inflammatory signalling cascades, and critical for protecting intestinal epithelial barrier function, regulating innate and adaptive immune responses, and finally for maintaining intestinal homeostasis. On one hand, dysfunction of PTPN2 has drastic effects on innate host defence mechanisms, including increased secretion of pro-inflammatory cytokines, limited autophagosome formation in response to invading pathogens, and disruption of the intestinal epithelial barrier. On the other hand, PTPN2 function is crucial for controlling adaptive immune functions, by regulating T cell proliferation and differentiation as well as maintaining T cell tolerance. In this way, dysfunction of PTPN2 contributes to the manifestation of IBD. The aim of this review is to present an overview of recent findings on the role of PTPN2 in intestinal homeostasis and the impact of dysfunctional PTPN2 on intestinal inflammation.展开更多
AIM: To elucidate the mechanisms of mesenteric vasodilation in portal hypertension (PHT), with a focus on endothelin signaling. METHODS: PHT was induced in rats by common bile duct ligation (CBDL). Portal pressure (PP...AIM: To elucidate the mechanisms of mesenteric vasodilation in portal hypertension (PHT), with a focus on endothelin signaling. METHODS: PHT was induced in rats by common bile duct ligation (CBDL). Portal pressure (PP) was measured directly via catheters placed in the portal vein tract. The level of endothelin-1 (ET-1) in the mesenteric circulation was determined by radioimmunoassay, and the expression of the endothelin A receptor (ETAR) and endothelin B receptor (ETBR) was assessed by immunofluorescence and Western blot. Additionally, expression of G protein coupled kinase-2 (GRK2) and β-arrestin 2, which influence endothelin receptor sensitivity, were also studied by Western blot. RESULTS: PP of CBDL rats increased significantly (11.89 ± 1.38 mmHg vs 16.34 ± 1.63 mmHg). ET-1 expression decreased in the mesenteric circulation 2 and 4 wk after CBDL. ET-1 levels in the systemic circulation of CBDL rats were increased at 2 wk and decreased at 4 wk. There was no change in ETAR expression in response to CBDL; however, increased expression of ETBR in the endothelial cells of mesenteric arterioles and capillaries was observed. In sham-operated rats, ETBR was mainly expressed in the CD31+ endothelial cells of the arterioles. With development of PHT, in addition to the endothelial cells, ETBR expression was noticeably detectable in the SMA+ smooth muscle cells of arterioles and in the CD31+ capillaries. Following CBDL, increased expression of GRK2 was also found in mesenteric tissue, though there was no change in the level of β-arrestin 2. CONCLUSION: Decreased levels of ET-1 and increased ETBR expression in the mesenteric circulation following CBDL in rats may underlie mesenteric vasodilation in individuals with PHT. Mechanistically, increased GRK2 expression may lead to desensitization of ETAR, as well as other vasoconstrictors, promoting this vasodilatory effect.展开更多
AIM:To explore the alteration of tyrosine phosphatase SHP-2 protein expression in gastric cancer and to assess its prognostic values.METHODS:Three hundred and five consecutive cases of gastric cancer were enrolled int...AIM:To explore the alteration of tyrosine phosphatase SHP-2 protein expression in gastric cancer and to assess its prognostic values.METHODS:Three hundred and five consecutive cases of gastric cancer were enrolled into this study.SHP-2 expression was carried out in 305 gastric cancer specimens,of which 83 were paired adjacent normal gastric mucus samples,using a tissue microarray immunohistochemical method.Correlations were analyzed between expression levels of SHP-2 protein and tumor parameters or clinical outcomes.Serum anti-Helicobacter pylori(H.pylori) immunoglobulin G was detected with enzyme-linked immunosorbent assay.Cox proportional hazards model was used to evaluate prognostic values by compassion of the expression levels of SHP-2 and disease-specific survivals in patients.RESULTS:SHP-2 staining was found diffuse mainly in the cytoplasm and the weak staining was also observed in the nucleus in gastric mucosa cells.Thirty-two point five percent of normal epithelial specimen and 62.6% of gastric cancer specimen were identified to stain with SHP-2 antibody positively(P < 0.001).Though SHP-2 staining intensities were stronger in the H.pylori(+) group than in the H.pylori(-) group,no statistically significant difference was found in the expression levels of SHP-2 between H.pylori(+) and H.pylori(-) gastric cancer(P = 0.40).The SHP-2 expression in gastric cancer was not significantly associated with cancer stages,lymph node metastases,and distant metastasis of the tumors(P = 0.34,P = 0.17,P = 0.52).Multivariate analysis demonstrated no correlation between SHP-2 expression and disease-free survival(P = 0.86).CONCLUSION:Increased expression of SHP-2 protein in gastric cancer specimen suggesting the aberrant upregulation of SHP-2 protein might play an important role in the gastric carcinogenesis.展开更多
Oleanolic acid derivatives act as newer protein tyrosine phosphatase 1B(PTP-1B) inhibitors for type 2 diabetes mellitus(T2DM). In order to understand the structural requirement of PTP-1B inhibitors, 52 oleanolic acid ...Oleanolic acid derivatives act as newer protein tyrosine phosphatase 1B(PTP-1B) inhibitors for type 2 diabetes mellitus(T2DM). In order to understand the structural requirement of PTP-1B inhibitors, 52 oleanolic acid derivatives were divided into a training set(34 compounds) and a test set(18 compounds). The highly reliable and predictive 3D-QSAR models were constructed by CoM FA, CoM SIA and topomer Co MFA methods, respectively. The results showed that the cross validated coefficient(q2) and non-cross-validated coefficient(R^2) were 0.554 and 0.999 in the CoM FA model, 0.675 and 0.971 in the CoM SIA model, and 0.628 and 0.939 in the topomer Co MFA model, which suggests that three models are robust and have good exterior predictive capabilities. Furthermore, ten novel inhibitors with much higher inhibitory potency were designed. Our design strategy was that(i) the electronegative substituents(Cl,-CH_2OH, OH and-CH_2Cl) were introduced into the double bond of ring C,(ii) the hydrogen bond acceptor groups(C≡N and N atom), electronegative groups(C≡N, N atom,-COOH and-COOCH_3) and bulky substituents(C_6H_5N) were connected to the C-3 position, which would result in generating potent and selective PTP-1B inhibitors. We expect that the results in this paper have the potential to facilitate the process of design and to develop new potent PTP-1B inhibitors.展开更多
Mitochondrial dysfunction is a significant pathological alte ration that occurs in Parkinson's disease(PD),and the Thr61lle(T61I)mutation in coiled-coil helix coiled-coil helix domain containing 2(CHCHD2),a crucia...Mitochondrial dysfunction is a significant pathological alte ration that occurs in Parkinson's disease(PD),and the Thr61lle(T61I)mutation in coiled-coil helix coiled-coil helix domain containing 2(CHCHD2),a crucial mitochondrial protein,has been reported to cause Parkinson's disease.FIFO-ATPase participates in the synthesis of cellular adenosine triphosphate(ATP)and plays a central role in mitochondrial energy metabolism.However,the specific roles of wild-type(WT)CHCHD2 and T611-mutant CHCHD2 in regulating F1FO-ATPase activity in Parkinson's disease,as well as whether CHCHD2 or CHCHD2 T61I affects mitochondrial function through regulating F1FO-ATPase activity,remain unclea r.Therefore,in this study,we expressed WT CHCHD2 and T61l-mutant CHCHD2 in an MPP^(+)-induced SH-SY5Y cell model of PD.We found that CHCHD2 protected mitochondria from developing MPP^(+)-induced dysfunction.Under normal conditions,ove rexpression of WT CHCHD2 promoted F1FO-ATPase assembly,while T61I-mutant CHCHD2 appeared to have lost the ability to regulate F1FO-ATPase assembly.In addition,mass spectrometry and immunoprecipitation showed that there was an interaction between CHCHD2 and F1FO-ATPase.Three weeks after transfection with AAV-CHCHD2 T61I,we intraperitoneally injected 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine into mice to establish an animal model of chronic Parkinson's disease and found that exogenous expression of the mutant protein worsened the behavioral deficits and dopaminergic neurodegeneration seen in this model.These findings suggest that WT CHCHD2 can alleviate mitochondrial dysfunction in PD by maintaining F1F0-ATPase structure and function.展开更多
BACKGROUND:Electromagnetic radiation can influence dopamine(DA) synthesis in brain tissues or cells,but electromagnetic frequencies,intensities,and radiation time can produce different effects.In addition,the signal p...BACKGROUND:Electromagnetic radiation can influence dopamine(DA) synthesis in brain tissues or cells,but electromagnetic frequencies,intensities,and radiation time can produce different effects.In addition,the signal pathway by which electromagnetic radiation influences DA synthesis remains controversial.OBJECTIVE:To determine tyrosine hydroxylase(TH) expression in PC12 cells and DA levels in cell culture media after different periods of low-frequency pulsed electric field(LF-PEF) stimulation,and to determine how LF-PEF signaling stimulates TH synthesis using inhibitors.DESIGN,TIME AND SETTING:A parallel,controlled,cell experiment was performed at the Laboratory of Cell Biology,School of Life Science,East China Normal University,between January and October 2006.MATERIALS:PC12 cells were purchased from the Shanghai Institute of Biochemistry and Cell Biology,Chinese Academy of Sciences,China.Nerve growth factor was purchased from PeproTech,USA.The protein kinase A inhibitor,H-89,and mitogen-activated protein kinase kinase inhibitor,U0126,were purchased from Sigma,USA.METHODS:(1) Following routine culture in Dulbecco's modified eagle medium,primary PC12 cells were stimulated under LF-PEF(pulse frequency 50 Hz,pulse width 20 μs,peak field strength 1 V/m) for 5,10,15,20,and 30 minutes.(2) Inhibitors(H-89 or U0126,1 μmol/L) were added 30 minutes before LF-PEF stimulation for 10 minutes.MAIN OUTCOME MEASURES:(1) TH expression was determined by Western blot in PC12 cells at 0.5,1,2,3,and 4 days after LF-PEF stimulation.Similarly,DA was measured by high-performance liquid chromatography in media at 2,3,4,or 5 days after LF-PEF.(2) TH expression was detected 1 day after H-89 or U0126 treatment and LF-PEF.RESULTS:(1) Short-term LF-PEF stimulation(5 and 10 minutes) increased TH expression and media DA levels after short-term culture(2 days)(P<0.01),but both parameters decreased with longer culture(3-4 days)(P<0.01).Long-term LF-PEF stimulation(15,20,or 30 minutes) decreased TH and DA synthesis,followed by a rapid increase(P<0.01).(2) H89 could completely inhibit TH expression in PC12 cells stimulated by LF-PEF for 10 minutes,while the inhibition rate of U0126 was 53.2%.CONCLUSION:Short-term LF-PEF first promotes then inhibits,while long-term LF-PEF first inhibits then promotes,TH and DA synthesis.LF-PEF stimulation regulates TH expression primarily by activating protein kinase A to regulate DA synthesis.展开更多
目的观察柴胡皂苷D对非小细胞肺癌(NSCLC)H460细胞增殖、凋亡的影响,并探讨可能机制。方法取对数期H460细胞,随机分为对照组,实验A、B、C组,对照组常规培养,实验A组加入柴胡皂苷D(20μmol/L),实验B组加入colivelin[Janus蛋白酪氨酸激酶2...目的观察柴胡皂苷D对非小细胞肺癌(NSCLC)H460细胞增殖、凋亡的影响,并探讨可能机制。方法取对数期H460细胞,随机分为对照组,实验A、B、C组,对照组常规培养,实验A组加入柴胡皂苷D(20μmol/L),实验B组加入colivelin[Janus蛋白酪氨酸激酶2(JAK2)/信号转导及转录激活子3(STAT3)通路激活剂](0.5μmol/L),实验C组加入柴胡皂苷D(20μmol/L)与colivelin(0.5μmol/L)。MTT法检测细胞增殖能力;双染法检测细胞凋亡率;实时荧光定量聚合酶链反应(qRT-PCR)法检测细胞白介素-2(IL-2)、白介素-10(IL-10)mRNA表达量;Western blotting法检测细胞p-JAK2、JAK2、p-STAT3、STAT3蛋白表达量。结果与对照组比较,实验A组24、48、72 h MTT实验吸光度值、细胞IL-10 mRNA表达量、p-JAK2/JAK2、p-STAT3/STAT3降低,细胞凋亡率、IL-2 mRNA表达量升高(P<0.05),实验B组24、48、72 h MTT实验吸光度值、细胞IL-10 mRNA表达量、p-JAK2/JAK2、p-STAT3/STAT3升高,细胞凋亡率、IL-2 mRNA表达量降低(P<0.05);与实验A组比较,实验C组24、48、72 h MTT实验吸光度值、细胞IL-10 mRNA表达量、p-JAK2/JAK2、p-STAT3/STAT3升高,细胞凋亡率、IL-2 mRNA表达量降低(P<0.05);与实验B组比较,联合组24、48、72 h MTT实验吸光度值、细胞IL-10 mRNA表达量、p-JAK2/JAK2、p-STAT3/STAT3降低,细胞凋亡率、IL-2 mRNA表达量升高(P<0.05)。结论柴胡皂苷D可抑制NSCLC细胞增殖,促进其凋亡,其作用机制可能与抑制JAK2/STAT3信号通路有关。展开更多
Heat shock proteins (HSPs) serve to correct proteins’ conformation, send the damaged proteins for degradation (quality control function). Heat shock factors (HSFs) are their transcription factors. The protein complex...Heat shock proteins (HSPs) serve to correct proteins’ conformation, send the damaged proteins for degradation (quality control function). Heat shock factors (HSFs) are their transcription factors. The protein complexes mTOR1 and 2 (with the same core mTOR), the phosphoinositide-dependent protein kinase-1 (PDK1), the seine/threonine-specific protein kinase (Akt), HSF1, plus their associated proteins form a network participating in protein synthesis, bio-energy generation, signaling for apoptosis with the help of HSPs. A cancer cell synthesizes proteins at fast rate and needs more HSPs to work on quality control. Shutting down this network would lead to cell death. Thus inhibitors of mTOR (mTORI) and inhibitors of HSPs (HSPI) could drive cancer cell to apoptosis—a “passive approach”. On the other hand, HSPs form complexes with polypeptides characteristic of the cancer cells;on excretion from the cell, they becomes antigens for the immunity cells, eventually leading to maturation of the cytotoxic T cells, forming the basic principle of preparing cancer-specific, person-specific vaccine. Recent finding shows that HSP70 can penetrate cancer cell and expel its analog to extracellular region, giving the hope to prepare a non-person-specific vaccine covering a variety of cancers. Activation of anti-cancer immunity is the “active approach”. On the other hand, mild hyperthermia, with increase of intracellular HSPs, has been found to activate the immunity response, and demonstrate anti-cancer effects. There are certain “mysteries” behind the mechanisms of the active and passive approaches. We analyze the mechanisms involved and provide explanations to some mysteries. We also suggest future research to improve our understanding of these two approaches, in which HSPs play many roles.展开更多
X-linked methyl-CpG binding protein 2 mutations can induce symptoms similar to those of Parkinson's disease and dopamine metabolism disorders, but the specific role of X-linked methyl-CpG binding protein 2 in the ...X-linked methyl-CpG binding protein 2 mutations can induce symptoms similar to those of Parkinson's disease and dopamine metabolism disorders, but the specific role of X-linked methyl-CpG binding protein 2 in the pathogenesis of Parkinson's disease remains unknown. In the present study, we used 6-hydroxydopamine-induced human neuroblastoma cell (SH-SY5Y cells) injury as a cell model of Parkinson's disease. The 6-hydroxydopamine (50 μmol/L) treatment decreased protein levels for both X-linked methyl-CpG binding protein 2 and tyrosine hydroxylase in these cells, and led to cell death. However, overexpression of X-linked methyl-CpG binding protein 2 was able to ameliorate the effects of 6-hydroxydopamine, it reduced 6-hydroxydopamine-induced apoptosis, and increased the levels of tyrosine hydroxylase in SH-SY5Y cells. These findings suggesting that X-linked methyl-CpG binding protein 2 may be a potential therapeutic target for the treatment of Parkinson's disease.展开更多
基金Supported by Grants from the Swiss National Science Foundation(SNF)to MSGrant No.314730-146204 and No.CRSII3_154488/1(to Rogler G)+2 种基金Grant No.310030-120312the Swiss IBD CohortGrant No.3347CO-108792
文摘Genome wide association studies have associated single nucleotide polymorphisms within the gene locus encoding protein tyrosine phosphatase non-receptor type 2(PTPN2) with the onset of inflammatory bowel disease(IBD) and other inflammatory disorders. Expression of PTPN2 is enhanced in actively inflamed intestinal tissue featuring a marked up-regulation in intestinal epithelial cells. PTPN2 deficient mice suffer from severe intestinal and systemic inflammation and display aberrant innate and adaptive immune responses. In particular, PTPN2 is involved in the regulation of inflammatory signalling cascades, and critical for protecting intestinal epithelial barrier function, regulating innate and adaptive immune responses, and finally for maintaining intestinal homeostasis. On one hand, dysfunction of PTPN2 has drastic effects on innate host defence mechanisms, including increased secretion of pro-inflammatory cytokines, limited autophagosome formation in response to invading pathogens, and disruption of the intestinal epithelial barrier. On the other hand, PTPN2 function is crucial for controlling adaptive immune functions, by regulating T cell proliferation and differentiation as well as maintaining T cell tolerance. In this way, dysfunction of PTPN2 contributes to the manifestation of IBD. The aim of this review is to present an overview of recent findings on the role of PTPN2 in intestinal homeostasis and the impact of dysfunctional PTPN2 on intestinal inflammation.
基金Supported by Grant from National Key New Drug Creation Project of China, No. 2009ZX09102
文摘AIM: To elucidate the mechanisms of mesenteric vasodilation in portal hypertension (PHT), with a focus on endothelin signaling. METHODS: PHT was induced in rats by common bile duct ligation (CBDL). Portal pressure (PP) was measured directly via catheters placed in the portal vein tract. The level of endothelin-1 (ET-1) in the mesenteric circulation was determined by radioimmunoassay, and the expression of the endothelin A receptor (ETAR) and endothelin B receptor (ETBR) was assessed by immunofluorescence and Western blot. Additionally, expression of G protein coupled kinase-2 (GRK2) and β-arrestin 2, which influence endothelin receptor sensitivity, were also studied by Western blot. RESULTS: PP of CBDL rats increased significantly (11.89 ± 1.38 mmHg vs 16.34 ± 1.63 mmHg). ET-1 expression decreased in the mesenteric circulation 2 and 4 wk after CBDL. ET-1 levels in the systemic circulation of CBDL rats were increased at 2 wk and decreased at 4 wk. There was no change in ETAR expression in response to CBDL; however, increased expression of ETBR in the endothelial cells of mesenteric arterioles and capillaries was observed. In sham-operated rats, ETBR was mainly expressed in the CD31+ endothelial cells of the arterioles. With development of PHT, in addition to the endothelial cells, ETBR expression was noticeably detectable in the SMA+ smooth muscle cells of arterioles and in the CD31+ capillaries. Following CBDL, increased expression of GRK2 was also found in mesenteric tissue, though there was no change in the level of β-arrestin 2. CONCLUSION: Decreased levels of ET-1 and increased ETBR expression in the mesenteric circulation following CBDL in rats may underlie mesenteric vasodilation in individuals with PHT. Mechanistically, increased GRK2 expression may lead to desensitization of ETAR, as well as other vasoconstrictors, promoting this vasodilatory effect.
基金Supported by National Natural Science Foundation of China,No. 81072369Natural Science Foundation of Jilin Province,China,No. 200905131
文摘AIM:To explore the alteration of tyrosine phosphatase SHP-2 protein expression in gastric cancer and to assess its prognostic values.METHODS:Three hundred and five consecutive cases of gastric cancer were enrolled into this study.SHP-2 expression was carried out in 305 gastric cancer specimens,of which 83 were paired adjacent normal gastric mucus samples,using a tissue microarray immunohistochemical method.Correlations were analyzed between expression levels of SHP-2 protein and tumor parameters or clinical outcomes.Serum anti-Helicobacter pylori(H.pylori) immunoglobulin G was detected with enzyme-linked immunosorbent assay.Cox proportional hazards model was used to evaluate prognostic values by compassion of the expression levels of SHP-2 and disease-specific survivals in patients.RESULTS:SHP-2 staining was found diffuse mainly in the cytoplasm and the weak staining was also observed in the nucleus in gastric mucosa cells.Thirty-two point five percent of normal epithelial specimen and 62.6% of gastric cancer specimen were identified to stain with SHP-2 antibody positively(P < 0.001).Though SHP-2 staining intensities were stronger in the H.pylori(+) group than in the H.pylori(-) group,no statistically significant difference was found in the expression levels of SHP-2 between H.pylori(+) and H.pylori(-) gastric cancer(P = 0.40).The SHP-2 expression in gastric cancer was not significantly associated with cancer stages,lymph node metastases,and distant metastasis of the tumors(P = 0.34,P = 0.17,P = 0.52).Multivariate analysis demonstrated no correlation between SHP-2 expression and disease-free survival(P = 0.86).CONCLUSION:Increased expression of SHP-2 protein in gastric cancer specimen suggesting the aberrant upregulation of SHP-2 protein might play an important role in the gastric carcinogenesis.
基金Supported by the Natural Science Foundation of Guangxi Province(Nos.2013GXNSFAA019019 and 2013GXNSFAA019041)
文摘Oleanolic acid derivatives act as newer protein tyrosine phosphatase 1B(PTP-1B) inhibitors for type 2 diabetes mellitus(T2DM). In order to understand the structural requirement of PTP-1B inhibitors, 52 oleanolic acid derivatives were divided into a training set(34 compounds) and a test set(18 compounds). The highly reliable and predictive 3D-QSAR models were constructed by CoM FA, CoM SIA and topomer Co MFA methods, respectively. The results showed that the cross validated coefficient(q2) and non-cross-validated coefficient(R^2) were 0.554 and 0.999 in the CoM FA model, 0.675 and 0.971 in the CoM SIA model, and 0.628 and 0.939 in the topomer Co MFA model, which suggests that three models are robust and have good exterior predictive capabilities. Furthermore, ten novel inhibitors with much higher inhibitory potency were designed. Our design strategy was that(i) the electronegative substituents(Cl,-CH_2OH, OH and-CH_2Cl) were introduced into the double bond of ring C,(ii) the hydrogen bond acceptor groups(C≡N and N atom), electronegative groups(C≡N, N atom,-COOH and-COOCH_3) and bulky substituents(C_6H_5N) were connected to the C-3 position, which would result in generating potent and selective PTP-1B inhibitors. We expect that the results in this paper have the potential to facilitate the process of design and to develop new potent PTP-1B inhibitors.
基金supported by the National Natural Science Foundation of China(Youth Program),No.81901282(to XC)the National Natural Science Foundation of China,Nos.81401416(to PX),81870992(to PX),81870856(to XC and MZ)+3 种基金Guangdong Basic and Applied Basic Research Foundation the Science Foundation,No.2019A1515011189(to XC)Central Government Guiding Local Science and Technology Development Projects,No.ZYYD2022C17(to PX)Key Project of Guangzhou Health Commission,No.2019-ZD-09(to PX)Science and Technology Planning Project of Guangzhou,Nos.202102020029(to XC),202102010010(to PX)。
文摘Mitochondrial dysfunction is a significant pathological alte ration that occurs in Parkinson's disease(PD),and the Thr61lle(T61I)mutation in coiled-coil helix coiled-coil helix domain containing 2(CHCHD2),a crucial mitochondrial protein,has been reported to cause Parkinson's disease.FIFO-ATPase participates in the synthesis of cellular adenosine triphosphate(ATP)and plays a central role in mitochondrial energy metabolism.However,the specific roles of wild-type(WT)CHCHD2 and T611-mutant CHCHD2 in regulating F1FO-ATPase activity in Parkinson's disease,as well as whether CHCHD2 or CHCHD2 T61I affects mitochondrial function through regulating F1FO-ATPase activity,remain unclea r.Therefore,in this study,we expressed WT CHCHD2 and T61l-mutant CHCHD2 in an MPP^(+)-induced SH-SY5Y cell model of PD.We found that CHCHD2 protected mitochondria from developing MPP^(+)-induced dysfunction.Under normal conditions,ove rexpression of WT CHCHD2 promoted F1FO-ATPase assembly,while T61I-mutant CHCHD2 appeared to have lost the ability to regulate F1FO-ATPase assembly.In addition,mass spectrometry and immunoprecipitation showed that there was an interaction between CHCHD2 and F1FO-ATPase.Three weeks after transfection with AAV-CHCHD2 T61I,we intraperitoneally injected 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine into mice to establish an animal model of chronic Parkinson's disease and found that exogenous expression of the mutant protein worsened the behavioral deficits and dopaminergic neurodegeneration seen in this model.These findings suggest that WT CHCHD2 can alleviate mitochondrial dysfunction in PD by maintaining F1F0-ATPase structure and function.
基金the National Natural Science Foundation of China,No.50677022
文摘BACKGROUND:Electromagnetic radiation can influence dopamine(DA) synthesis in brain tissues or cells,but electromagnetic frequencies,intensities,and radiation time can produce different effects.In addition,the signal pathway by which electromagnetic radiation influences DA synthesis remains controversial.OBJECTIVE:To determine tyrosine hydroxylase(TH) expression in PC12 cells and DA levels in cell culture media after different periods of low-frequency pulsed electric field(LF-PEF) stimulation,and to determine how LF-PEF signaling stimulates TH synthesis using inhibitors.DESIGN,TIME AND SETTING:A parallel,controlled,cell experiment was performed at the Laboratory of Cell Biology,School of Life Science,East China Normal University,between January and October 2006.MATERIALS:PC12 cells were purchased from the Shanghai Institute of Biochemistry and Cell Biology,Chinese Academy of Sciences,China.Nerve growth factor was purchased from PeproTech,USA.The protein kinase A inhibitor,H-89,and mitogen-activated protein kinase kinase inhibitor,U0126,were purchased from Sigma,USA.METHODS:(1) Following routine culture in Dulbecco's modified eagle medium,primary PC12 cells were stimulated under LF-PEF(pulse frequency 50 Hz,pulse width 20 μs,peak field strength 1 V/m) for 5,10,15,20,and 30 minutes.(2) Inhibitors(H-89 or U0126,1 μmol/L) were added 30 minutes before LF-PEF stimulation for 10 minutes.MAIN OUTCOME MEASURES:(1) TH expression was determined by Western blot in PC12 cells at 0.5,1,2,3,and 4 days after LF-PEF stimulation.Similarly,DA was measured by high-performance liquid chromatography in media at 2,3,4,or 5 days after LF-PEF.(2) TH expression was detected 1 day after H-89 or U0126 treatment and LF-PEF.RESULTS:(1) Short-term LF-PEF stimulation(5 and 10 minutes) increased TH expression and media DA levels after short-term culture(2 days)(P<0.01),but both parameters decreased with longer culture(3-4 days)(P<0.01).Long-term LF-PEF stimulation(15,20,or 30 minutes) decreased TH and DA synthesis,followed by a rapid increase(P<0.01).(2) H89 could completely inhibit TH expression in PC12 cells stimulated by LF-PEF for 10 minutes,while the inhibition rate of U0126 was 53.2%.CONCLUSION:Short-term LF-PEF first promotes then inhibits,while long-term LF-PEF first inhibits then promotes,TH and DA synthesis.LF-PEF stimulation regulates TH expression primarily by activating protein kinase A to regulate DA synthesis.
文摘目的观察柴胡皂苷D对非小细胞肺癌(NSCLC)H460细胞增殖、凋亡的影响,并探讨可能机制。方法取对数期H460细胞,随机分为对照组,实验A、B、C组,对照组常规培养,实验A组加入柴胡皂苷D(20μmol/L),实验B组加入colivelin[Janus蛋白酪氨酸激酶2(JAK2)/信号转导及转录激活子3(STAT3)通路激活剂](0.5μmol/L),实验C组加入柴胡皂苷D(20μmol/L)与colivelin(0.5μmol/L)。MTT法检测细胞增殖能力;双染法检测细胞凋亡率;实时荧光定量聚合酶链反应(qRT-PCR)法检测细胞白介素-2(IL-2)、白介素-10(IL-10)mRNA表达量;Western blotting法检测细胞p-JAK2、JAK2、p-STAT3、STAT3蛋白表达量。结果与对照组比较,实验A组24、48、72 h MTT实验吸光度值、细胞IL-10 mRNA表达量、p-JAK2/JAK2、p-STAT3/STAT3降低,细胞凋亡率、IL-2 mRNA表达量升高(P<0.05),实验B组24、48、72 h MTT实验吸光度值、细胞IL-10 mRNA表达量、p-JAK2/JAK2、p-STAT3/STAT3升高,细胞凋亡率、IL-2 mRNA表达量降低(P<0.05);与实验A组比较,实验C组24、48、72 h MTT实验吸光度值、细胞IL-10 mRNA表达量、p-JAK2/JAK2、p-STAT3/STAT3升高,细胞凋亡率、IL-2 mRNA表达量降低(P<0.05);与实验B组比较,联合组24、48、72 h MTT实验吸光度值、细胞IL-10 mRNA表达量、p-JAK2/JAK2、p-STAT3/STAT3降低,细胞凋亡率、IL-2 mRNA表达量升高(P<0.05)。结论柴胡皂苷D可抑制NSCLC细胞增殖,促进其凋亡,其作用机制可能与抑制JAK2/STAT3信号通路有关。
文摘Heat shock proteins (HSPs) serve to correct proteins’ conformation, send the damaged proteins for degradation (quality control function). Heat shock factors (HSFs) are their transcription factors. The protein complexes mTOR1 and 2 (with the same core mTOR), the phosphoinositide-dependent protein kinase-1 (PDK1), the seine/threonine-specific protein kinase (Akt), HSF1, plus their associated proteins form a network participating in protein synthesis, bio-energy generation, signaling for apoptosis with the help of HSPs. A cancer cell synthesizes proteins at fast rate and needs more HSPs to work on quality control. Shutting down this network would lead to cell death. Thus inhibitors of mTOR (mTORI) and inhibitors of HSPs (HSPI) could drive cancer cell to apoptosis—a “passive approach”. On the other hand, HSPs form complexes with polypeptides characteristic of the cancer cells;on excretion from the cell, they becomes antigens for the immunity cells, eventually leading to maturation of the cytotoxic T cells, forming the basic principle of preparing cancer-specific, person-specific vaccine. Recent finding shows that HSP70 can penetrate cancer cell and expel its analog to extracellular region, giving the hope to prepare a non-person-specific vaccine covering a variety of cancers. Activation of anti-cancer immunity is the “active approach”. On the other hand, mild hyperthermia, with increase of intracellular HSPs, has been found to activate the immunity response, and demonstrate anti-cancer effects. There are certain “mysteries” behind the mechanisms of the active and passive approaches. We analyze the mechanisms involved and provide explanations to some mysteries. We also suggest future research to improve our understanding of these two approaches, in which HSPs play many roles.
基金sponsored by the Ph.D.Independent Research Projects of Wuhan University,No.201130302020017a grant from the Science and Technology Bureau of Hubei Province,No.2011CDB511the National Natural Science Foundation of China,No.81170769
文摘X-linked methyl-CpG binding protein 2 mutations can induce symptoms similar to those of Parkinson's disease and dopamine metabolism disorders, but the specific role of X-linked methyl-CpG binding protein 2 in the pathogenesis of Parkinson's disease remains unknown. In the present study, we used 6-hydroxydopamine-induced human neuroblastoma cell (SH-SY5Y cells) injury as a cell model of Parkinson's disease. The 6-hydroxydopamine (50 μmol/L) treatment decreased protein levels for both X-linked methyl-CpG binding protein 2 and tyrosine hydroxylase in these cells, and led to cell death. However, overexpression of X-linked methyl-CpG binding protein 2 was able to ameliorate the effects of 6-hydroxydopamine, it reduced 6-hydroxydopamine-induced apoptosis, and increased the levels of tyrosine hydroxylase in SH-SY5Y cells. These findings suggesting that X-linked methyl-CpG binding protein 2 may be a potential therapeutic target for the treatment of Parkinson's disease.
