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
The differences in nitrogen/phosphorus(N/P)ratios of different functional groups in ecology are more helpful in explaining species competition and community dynamics.Based on the functional groups of plant growth type...The differences in nitrogen/phosphorus(N/P)ratios of different functional groups in ecology are more helpful in explaining species competition and community dynamics.Based on the functional groups of plant growth type,carbon metabolism pathway,root type and phylogenetic type,we analyzed characteristics of leaf N/P ratios of 77 species in Sanggendalai(typical grassland zone)of Zhenglan Banner,Inner Mongolia,China and 91 species in the Habahu National Nature Reserve(desertified grassland zone)in Yanchi County of Ningxia,China.The results show that the N/P ratio(16.91)of C3 plants in the desertified steppe was significantly larger than that(12.72)in the typical steppe,but there was no significant difference between the N/P ratios of C4 plants in the two zones.There was no significant difference in N/P ratios between C3 plants and C4 plants in the same zone.Similarly,the N/P ratio(16.60)of dicotyledons in desertified steppe were significantly higher than that(12.98)in typical steppe,while differences in N/P ratios between monocotyledonous plants of the two zones was not significant,and there existed no significant difference in N/P ratios between dicotyledonous and monocotyledonous plants in the same zone.The N/P ratio had significant difference between gramineous and non-gramineous plants in the typical steppe but not in the desertified steppe,but there existed no significant difference in N/P ratios among different root types of perennial herbaceous plants in the same type of steppe or between two types of steppe.Thus,different features on the N/P ratios of C3 plants and dicotyledonous plants between typical steppe and desertified steppe may lead to different growth status of plants,and the N/P ratio stoichiometric of the same plant functional group may be a foundation of the changes of a plant community.展开更多
Background:Parkinson’s disease(PD)is a chronic,progressive and debilitating disease,which affects over 2.5 million people in China.PD is characterized clinically by resting tremor,muscular rigidity,bradykinesia and p...Background:Parkinson’s disease(PD)is a chronic,progressive and debilitating disease,which affects over 2.5 million people in China.PD is characterized clinically by resting tremor,muscular rigidity,bradykinesia and postural instability.As the disease progresses,additional complications can arise such as non-motor and neurobehavioral symptoms.Pharmacological treatment and surgical intervention for PD have been implemented in China.Until 10 years ago,there was lack of standardization for the management of PD in different regions and among different physicians,leading to different treatment levels in different regions and different physicians.Since then,the Chinese Parkinson’s Disease and Movement Disorder Society have published three versions of guidelines for the management of PD in China,in 2006,2009 and 2014,respectively.Correspondingly,the overall level of treatment for PD in China improved.Objectives:To update the treatment guidelines based on current foreign and domestic practice guidelines and clinical evidence,and to improve the treatment options available to physicians in the management of PD.Summary:A variety of treatment recommendations in the treatment guidelines have been proposed,including physical activity and disease-modifying medication,which should be initiated at the early-stage of the disease.The principles of dosage titration should be followed to avoid acute adverse reactions to the drugs,to achieve a satisfactory clinical effect with a low dose and to reduce the incidence of long-term motor complications.Moreover,different treatment strategies should be considered at different stages of the disease.Importantly,treatment guidelines and personalized treatments should be valued equally.A set of treatment recommendations has been developed to assist physicians to improve and optimize clinical outcomes for patients with PD in China.展开更多
In this study, we conducted a clinical analysis of lymphocyte subtypes in 268 patients with Parkinson's disease(PD) to assess their clinical impact as a potential marker of advanced PD in Chinese patients. The par...In this study, we conducted a clinical analysis of lymphocyte subtypes in 268 patients with Parkinson's disease(PD) to assess their clinical impact as a potential marker of advanced PD in Chinese patients. The participants comprised 268 sporadic PD patients and 268 healthy controls. The numbers of natural killer(NK) cells and CD3+, CD3+CD4+, CD3+CD8+, and CD19+ lymphocytes from peripheral blood were determined by immunostaining and flow cytometric analysis and the percentages of these CD+ T cells were calculated. The ratio of regulatory T(Treg)/helper T 17(Th17) lymphocytes from 64 PD patients and 46 controls was determined by flow cytometric analysis.The results showed that the percentage of NK cells was higher in advanced PD patients than in controls(22.92% ±10.08% versus 19.76% ± 10.09%, P = 0.006), while CD3+ T cells are decreased(62.93% ± 9.27% versus65.75% ± 9.13%, P = 0.005). The percentage of CD19+B cells in male patients was lower(P = 0.021) than in female patients, whereas NK cells were increased(P \ 0.0001). The scores on the Unified Parkinson's Disease Rating Scale(UPDRS) and the Non-Motor Symptoms Scale in late-onset PD patients were significantly higher than those in earlyonset patients(P = 0.024 and P = 0.007, respectively). The percentage of CD19+ B cells in patients with UPDRS scores[24 was lower than in those with scores \24(10.17% ±4.19% versus 12.22% ± 5.39%, P = 0.009). In addition, the Treg/Th17 ratio in female patients was higher than that in female controls(13.88 ± 6.32 versus 9.94 ± 4.06, P =0.042). These results suggest that the percentages of NK cells,CD3+ T cells, and CD19+ B cells along with the Treg/Th17 ratio in peripheral blood may be used to predict the risk of PD in Chinese individuals and provide fresh avenues for novel diagnostic biomarkers and therapeutic designs.展开更多
Parkinson’s disease(PD)is referring to the multi-systemicα-synucleinopathy with Lewy bodies deposited in midbrain.In ageing,the environmental and genetic factors work together and overactive major histocompatibility...Parkinson’s disease(PD)is referring to the multi-systemicα-synucleinopathy with Lewy bodies deposited in midbrain.In ageing,the environmental and genetic factors work together and overactive major histocompatibility complex pathway to regulate immune reactions in central nerve system which resulting in neural degeneration,especially in dopaminergic neurons.As a series of biomarkers,the human leukocyte antigen genes with its related proteomics play cortical roles on the antigen presentation of major histocompatibility complex molecules to stimulate the differentiation of T lymphocytes and i-proteasome activities under their immune response to the PD-related environmental alteration and genetic variation.Furthermore,dopaminergic drugs change the biological characteristic of T lymphatic cells,affect theα-synuclein presentation pathway,and inhibit T lymphatic cells to release cytotoxicity in PD development.Taking together,the serum inflammatory factors and blood T cells are involved in the immune dysregulation of PD and inspected as the potential clinic biomarkers for PD prediction.展开更多
Background:Wnt/β-catenin signal has been reported to exert cytoprotective effects in cellular models of several diseases,including Parkinson’s disease(PD).This study aimed to investigate the neuroprotective effects ...Background:Wnt/β-catenin signal has been reported to exert cytoprotective effects in cellular models of several diseases,including Parkinson’s disease(PD).This study aimed to investigate the neuroprotective effects of actived Wnt/β-catenin signal by Wnt3a on SH-SY5Y cells treated with 6-hydroxydopamine(6-OHDA).Methods:Wnt3a-conditioned medium(Wnt3a-CM)was used to intervene dopaminegic SH-SY5Y cells treated with 6-OHDA.Cell toxicity was determined by cell viability and lactate dehydrogenase leakage(LDH)assay.The mitochondria function was measured by the mitochondrial membrane potential,while oxidative stress was monitored with intracellular reactive oxygen species(ROS).Western blot analysis was used to detect the expression of GSK3β,β-catenin as well as Akt.Results:Our results showed that 100μM 6-OHDA treated for 24 h significantly decreased cell viability and mitochondrial transmembrane potential,reduced the level ofβ-catenin and p-Akt,increased LDH leakage,ROS production and the ratio of p-GSK3β(Tyr216)to p-GSK3β(Ser9).However,Wnt3a-conditioned medium reversing SH-SY5Y cells against 6-OHDA-induced neurotoxicity by reversing these changes.Conclusions:Activating of Wnt/β-catenin pathway by Wnt3a-CM attenuated 6-OHDA-induced neurotoxicity significantly,which related to the inhibition of oxidative stress and maintenance of normal mitochondrial function.展开更多
Background:Parkinson’s disease(PD)is the second most common neurodegenerative disease after Alzheimer’s dementia.Mitochondrial dysfunction is involved in the pathology of PD.Coiled-coil-helix-coiled-coil-helix domai...Background:Parkinson’s disease(PD)is the second most common neurodegenerative disease after Alzheimer’s dementia.Mitochondrial dysfunction is involved in the pathology of PD.Coiled-coil-helix-coiled-coil-helix domain-containing 2(CHCHD2)was identified as associated with autosomal dominant PD.However,the mechanism of CHCHD2 in PD remains unclear.Methods:Short hairpin RNA(ShRNA)-mediated CHCHD2 knockdown or lentivirus-mediated CHCHD2 overexpression was performed to investigate the impact of CHCHD2 on mitochondrial morphology and function in neuronal tumor cell lines represented with human neuroblastoma(SHSY5Y)and HeLa cells.Blue-native polyacrylamide gel electrophoresis(PAGE)and two-dimensional sodium dodecyl sulfate-PAGE analysis were used to illustrate the role of CHCHD2 in mitochondrial contact site and cristae organizing system(MICOS).Co-immunoprecipitation and immunoblotting were used to address the interaction between CHCHD2 and Mic10.Serotype injection of adeno-associated vector-mediated CHCHD2 and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)administration were used to examine the influence of CHCHD2 in vivo.Results:We found that the overexpression of CHCHD2 can protect against methyl-4-phenylpyridinium(MPP+)-induced mitochondrial dysfunction and inhibit the loss of dopaminergic neurons in the MPTP-induced mouse model.Furthermore,we identified that CHCHD2 interacted with Mic10,and overexpression of CHCHD2 can protect against MPP+-induced MICOS impairment,while knockdown of CHCHD2 impaired the stability of MICOS.Conclusion:This study indicated that CHCHD2 could interact with Mic10 and maintain the stability of the MICOS complex,which contributes to protecting mitochondrial function in PD.展开更多
Previous studies suggest that the reduction of SMAD3(mothers against decapentaplegic homolog 3)has a great impact on tumor development,but its exact pathological function remains unclear.In this study,we found that th...Previous studies suggest that the reduction of SMAD3(mothers against decapentaplegic homolog 3)has a great impact on tumor development,but its exact pathological function remains unclear.In this study,we found that the protein level of SMAD3 was greatly reduced in human-grade IV glioblastoma tissues,in which LAMP2A(lysosome-associated membrane protein type 2A)was significantly up-regulated.LAMP2A is a key ratelimiting protein of chaperone-mediated autophagy(CMA),a lysosome pathway of protein degradation that is activated in glioma.We carefully analyzed the amino-acid sequence of SMAD3 and found that it contained a pentapeptide motif biochemically related to KFERQ,which has been proposed to be a targeting sequence for CMA.In vitro,we confirmed that SMAD3 was degraded in either serum-free or KFERQ motif deleted condition,which was regulated by LAMP2A and interacted with HSC70(heat shock cognate 71 kDa protein).Using isolated lysosomes,amino-acid residues 75 and 128 of SMAD3 were found to be of importance for this process,which affected the CMA pathway in which SMAD3 was involved.Similarly,down-regulating SMAD3 or up-regulating LAMP2A in cultured glioma cells enhanced their proliferation and invasion.Taken together,these results suggest that excessive activation of CMA regulates glioma cell growth by promoting the degradation of SMAD3.Therefore,targeting the SMAD3-LAMP2Amediated CMA-lysosome pathway may be a promising approach in anti-cancer therapy.展开更多
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supported by the National Key Research and Development Program of China (2016YFC0500706)
文摘The differences in nitrogen/phosphorus(N/P)ratios of different functional groups in ecology are more helpful in explaining species competition and community dynamics.Based on the functional groups of plant growth type,carbon metabolism pathway,root type and phylogenetic type,we analyzed characteristics of leaf N/P ratios of 77 species in Sanggendalai(typical grassland zone)of Zhenglan Banner,Inner Mongolia,China and 91 species in the Habahu National Nature Reserve(desertified grassland zone)in Yanchi County of Ningxia,China.The results show that the N/P ratio(16.91)of C3 plants in the desertified steppe was significantly larger than that(12.72)in the typical steppe,but there was no significant difference between the N/P ratios of C4 plants in the two zones.There was no significant difference in N/P ratios between C3 plants and C4 plants in the same zone.Similarly,the N/P ratio(16.60)of dicotyledons in desertified steppe were significantly higher than that(12.98)in typical steppe,while differences in N/P ratios between monocotyledonous plants of the two zones was not significant,and there existed no significant difference in N/P ratios between dicotyledonous and monocotyledonous plants in the same zone.The N/P ratio had significant difference between gramineous and non-gramineous plants in the typical steppe but not in the desertified steppe,but there existed no significant difference in N/P ratios among different root types of perennial herbaceous plants in the same type of steppe or between two types of steppe.Thus,different features on the N/P ratios of C3 plants and dicotyledonous plants between typical steppe and desertified steppe may lead to different growth status of plants,and the N/P ratio stoichiometric of the same plant functional group may be a foundation of the changes of a plant community.
基金This work was supported by the National Key Basic Research Program of China[grant numbers G1999054008,2006cb500706,2011CB504104]the National Natural Science Foundation of China[grant number 81430022]the Shanghai Science and Technology Fund[grant number 10411954500].
文摘Background:Parkinson’s disease(PD)is a chronic,progressive and debilitating disease,which affects over 2.5 million people in China.PD is characterized clinically by resting tremor,muscular rigidity,bradykinesia and postural instability.As the disease progresses,additional complications can arise such as non-motor and neurobehavioral symptoms.Pharmacological treatment and surgical intervention for PD have been implemented in China.Until 10 years ago,there was lack of standardization for the management of PD in different regions and among different physicians,leading to different treatment levels in different regions and different physicians.Since then,the Chinese Parkinson’s Disease and Movement Disorder Society have published three versions of guidelines for the management of PD in China,in 2006,2009 and 2014,respectively.Correspondingly,the overall level of treatment for PD in China improved.Objectives:To update the treatment guidelines based on current foreign and domestic practice guidelines and clinical evidence,and to improve the treatment options available to physicians in the management of PD.Summary:A variety of treatment recommendations in the treatment guidelines have been proposed,including physical activity and disease-modifying medication,which should be initiated at the early-stage of the disease.The principles of dosage titration should be followed to avoid acute adverse reactions to the drugs,to achieve a satisfactory clinical effect with a low dose and to reduce the incidence of long-term motor complications.Moreover,different treatment strategies should be considered at different stages of the disease.Importantly,treatment guidelines and personalized treatments should be valued equally.A set of treatment recommendations has been developed to assist physicians to improve and optimize clinical outcomes for patients with PD in China.
基金supported by the National Key R&D Program of China (2016YFC1306600)the National Natural Science Foundation of China (81471292, U1603281, U1503222, 81430021)+2 种基金the Science Foundation of Guangdong Province, China (2015A030311021)a Technology Project of Guangzhou Municipality, China (201504281820463)a Science and Technology Planning Project of Guangdong Province, China (2016A050502025)
文摘In this study, we conducted a clinical analysis of lymphocyte subtypes in 268 patients with Parkinson's disease(PD) to assess their clinical impact as a potential marker of advanced PD in Chinese patients. The participants comprised 268 sporadic PD patients and 268 healthy controls. The numbers of natural killer(NK) cells and CD3+, CD3+CD4+, CD3+CD8+, and CD19+ lymphocytes from peripheral blood were determined by immunostaining and flow cytometric analysis and the percentages of these CD+ T cells were calculated. The ratio of regulatory T(Treg)/helper T 17(Th17) lymphocytes from 64 PD patients and 46 controls was determined by flow cytometric analysis.The results showed that the percentage of NK cells was higher in advanced PD patients than in controls(22.92% ±10.08% versus 19.76% ± 10.09%, P = 0.006), while CD3+ T cells are decreased(62.93% ± 9.27% versus65.75% ± 9.13%, P = 0.005). The percentage of CD19+B cells in male patients was lower(P = 0.021) than in female patients, whereas NK cells were increased(P \ 0.0001). The scores on the Unified Parkinson's Disease Rating Scale(UPDRS) and the Non-Motor Symptoms Scale in late-onset PD patients were significantly higher than those in earlyonset patients(P = 0.024 and P = 0.007, respectively). The percentage of CD19+ B cells in patients with UPDRS scores[24 was lower than in those with scores \24(10.17% ±4.19% versus 12.22% ± 5.39%, P = 0.009). In addition, the Treg/Th17 ratio in female patients was higher than that in female controls(13.88 ± 6.32 versus 9.94 ± 4.06, P =0.042). These results suggest that the percentages of NK cells,CD3+ T cells, and CD19+ B cells along with the Treg/Th17 ratio in peripheral blood may be used to predict the risk of PD in Chinese individuals and provide fresh avenues for novel diagnostic biomarkers and therapeutic designs.
基金This review was supported by research grants from the State Key Development Program for Basic Research of China(2011CB510000)the National Natural Science Foundation of China(81271428,81471292,U1503222 and 81430021)+2 种基金the keypoint Science Foundation of Guangdong of China(2015A030311021)a grant supported by technology project of Guangzhou(201604020152)a grant supported by assisting research project of science and technology for Xinjiang(201591160).
文摘Parkinson’s disease(PD)is referring to the multi-systemicα-synucleinopathy with Lewy bodies deposited in midbrain.In ageing,the environmental and genetic factors work together and overactive major histocompatibility complex pathway to regulate immune reactions in central nerve system which resulting in neural degeneration,especially in dopaminergic neurons.As a series of biomarkers,the human leukocyte antigen genes with its related proteomics play cortical roles on the antigen presentation of major histocompatibility complex molecules to stimulate the differentiation of T lymphocytes and i-proteasome activities under their immune response to the PD-related environmental alteration and genetic variation.Furthermore,dopaminergic drugs change the biological characteristic of T lymphatic cells,affect theα-synuclein presentation pathway,and inhibit T lymphatic cells to release cytotoxicity in PD development.Taking together,the serum inflammatory factors and blood T cells are involved in the immune dysregulation of PD and inspected as the potential clinic biomarkers for PD prediction.
基金by Nature Science Foundation of China(81401058,81401645,81271428 and 81471292)a grant from the State Key Development Program for Basic Research of China(2011CB510000)+1 种基金a grant from Medical Scientific Research Foundation of Guangdong Province(B2014139)a grant supported by assisting research project of science and technology for Xinjiang(201591160).
文摘Background:Wnt/β-catenin signal has been reported to exert cytoprotective effects in cellular models of several diseases,including Parkinson’s disease(PD).This study aimed to investigate the neuroprotective effects of actived Wnt/β-catenin signal by Wnt3a on SH-SY5Y cells treated with 6-hydroxydopamine(6-OHDA).Methods:Wnt3a-conditioned medium(Wnt3a-CM)was used to intervene dopaminegic SH-SY5Y cells treated with 6-OHDA.Cell toxicity was determined by cell viability and lactate dehydrogenase leakage(LDH)assay.The mitochondria function was measured by the mitochondrial membrane potential,while oxidative stress was monitored with intracellular reactive oxygen species(ROS).Western blot analysis was used to detect the expression of GSK3β,β-catenin as well as Akt.Results:Our results showed that 100μM 6-OHDA treated for 24 h significantly decreased cell viability and mitochondrial transmembrane potential,reduced the level ofβ-catenin and p-Akt,increased LDH leakage,ROS production and the ratio of p-GSK3β(Tyr216)to p-GSK3β(Ser9).However,Wnt3a-conditioned medium reversing SH-SY5Y cells against 6-OHDA-induced neurotoxicity by reversing these changes.Conclusions:Activating of Wnt/β-catenin pathway by Wnt3a-CM attenuated 6-OHDA-induced neurotoxicity significantly,which related to the inhibition of oxidative stress and maintenance of normal mitochondrial function.
基金supported by research grants from the National Natural Science Foundation of China(Nos.81901282,81870992,82071444)the Nature Science Foundation of Guangdong Province(Nos.2019A1515011189,2020A1515010985)the Technology Project of Guangzhou(Nos.202102020029,2019ZD09).
文摘Background:Parkinson’s disease(PD)is the second most common neurodegenerative disease after Alzheimer’s dementia.Mitochondrial dysfunction is involved in the pathology of PD.Coiled-coil-helix-coiled-coil-helix domain-containing 2(CHCHD2)was identified as associated with autosomal dominant PD.However,the mechanism of CHCHD2 in PD remains unclear.Methods:Short hairpin RNA(ShRNA)-mediated CHCHD2 knockdown or lentivirus-mediated CHCHD2 overexpression was performed to investigate the impact of CHCHD2 on mitochondrial morphology and function in neuronal tumor cell lines represented with human neuroblastoma(SHSY5Y)and HeLa cells.Blue-native polyacrylamide gel electrophoresis(PAGE)and two-dimensional sodium dodecyl sulfate-PAGE analysis were used to illustrate the role of CHCHD2 in mitochondrial contact site and cristae organizing system(MICOS).Co-immunoprecipitation and immunoblotting were used to address the interaction between CHCHD2 and Mic10.Serotype injection of adeno-associated vector-mediated CHCHD2 and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)administration were used to examine the influence of CHCHD2 in vivo.Results:We found that the overexpression of CHCHD2 can protect against methyl-4-phenylpyridinium(MPP+)-induced mitochondrial dysfunction and inhibit the loss of dopaminergic neurons in the MPTP-induced mouse model.Furthermore,we identified that CHCHD2 interacted with Mic10,and overexpression of CHCHD2 can protect against MPP+-induced MICOS impairment,while knockdown of CHCHD2 impaired the stability of MICOS.Conclusion:This study indicated that CHCHD2 could interact with Mic10 and maintain the stability of the MICOS complex,which contributes to protecting mitochondrial function in PD.
基金supported by the National Key R&D Program of China(2016YFC1306601 and 2017YFC1306002)the National Natural Science Foundation of China(82071416,81870992,81870856,U1603281,81903958,81901282,and 82004459)+3 种基金the Natural Science Foundation of Guangdong Province(2020A1515010986,2019A1515011189,and 2018A030310521)a Science and Technol-ogy Planning Project of Guangdong Province(A2018315)a Tech-nology Project of Guangzhou(2018-1202-SF-0019 and 2019ZD09)and a China Postdoctoral Science Foundation Grant(2019M662873)。
文摘Previous studies suggest that the reduction of SMAD3(mothers against decapentaplegic homolog 3)has a great impact on tumor development,but its exact pathological function remains unclear.In this study,we found that the protein level of SMAD3 was greatly reduced in human-grade IV glioblastoma tissues,in which LAMP2A(lysosome-associated membrane protein type 2A)was significantly up-regulated.LAMP2A is a key ratelimiting protein of chaperone-mediated autophagy(CMA),a lysosome pathway of protein degradation that is activated in glioma.We carefully analyzed the amino-acid sequence of SMAD3 and found that it contained a pentapeptide motif biochemically related to KFERQ,which has been proposed to be a targeting sequence for CMA.In vitro,we confirmed that SMAD3 was degraded in either serum-free or KFERQ motif deleted condition,which was regulated by LAMP2A and interacted with HSC70(heat shock cognate 71 kDa protein).Using isolated lysosomes,amino-acid residues 75 and 128 of SMAD3 were found to be of importance for this process,which affected the CMA pathway in which SMAD3 was involved.Similarly,down-regulating SMAD3 or up-regulating LAMP2A in cultured glioma cells enhanced their proliferation and invasion.Taken together,these results suggest that excessive activation of CMA regulates glioma cell growth by promoting the degradation of SMAD3.Therefore,targeting the SMAD3-LAMP2Amediated CMA-lysosome pathway may be a promising approach in anti-cancer therapy.
