BACKGROUND： Diffusion tensor imaging （DTI） is one of the noninvasive methods to study the morphological structure of brain white matter fibrous bands in vivo, and it has been applied primarily in clinic. DTI is ack...BACKGROUND： Diffusion tensor imaging （DTI） is one of the noninvasive methods to study the morphological structure of brain white matter fibrous bands in vivo, and it has been applied primarily in clinic. DTI is acknowledged as the more effective imaging method to diagnose ultra-acute and/or acute cerebral infarction.OB_3ECTIVE： To observe the anisotropic characters of cerebral white matter fibrous bands in patients with ischemic stroke by using DTI, and investigate the correlation between the damage of corticospinal tract and muscle strength in patients with ischemic stroke at acute period.DESIGN： A case-control observationSEFIING： Department of Medical Imaging, Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA.PARTICIPANTS： Nine inpatients with injury of motor function induced by acute ischemic stroke （patient group） at 6 hours to 2 weeks after the attack were selected from the Department of Neurology, Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA from September 2005 to March 2006, and they all accorded with the present diagnostic standard for cerebrovascular disease in China. There were 5 males and 4 females, aged 16-87 years. At the same time, nine healthy right-handed physical examinees matched by age and sex with the patients were taken as the control group, and they all had no nervous disease, mental diseases, cerebrovascular abnormalities and injury history, etc. All the subjects were informed with the detected items and agreed to participate in the study.METHODS： All the 9 patients with ischemic stroke at acute period and 9 healthy subjects were examined with MRI, T1 weighted imaging, T2 weighted imaging and DTI. And the data were processed offline with dTV.II software, the images of fractional anisotropy and directional encoded color （DEC） were obtained, and the three-dimensional fibrous band images of bilateral corticospinal tracts were reconstructed. In the control group, the values of fractional anisotropy of main white matter fibrous bands were measured in the region of interest （ROI） of the anterior limb, knee and posterior limb of internal capsule. In the patient group, the values of fractional anisotropy of white matter were measured in the infarcted sites and corresponding contralateral sites of the patients. The ROI was set in bilateral cerebral peduncles to reconstruct three-dimensionally the bilateral corticospinal tracts. The muscle strength of the affected hand was assessed with Brunnstorm standard in the stroke patients.MAIN OUTCOME MEASURES ： The characters of DTI and images of the value of fractional anisotropy, and the manifestations of three-dimensional corticospinal tracts were observed in the two groups.RESULTS： All the data from the 9 patients and 9 healthy volunteers were involved in the analysis of results. In the control group, the white matter and gray matter could be distinguished clearly in the image of fractional anisotropic values, the fibers of different directions were shown by different colors in DEC picture, which clearly demonstrated the normal anatomic structure and direction of white matter fibers. In the patient group, the infarctions occurred in the gray matter or white matter could be distinguished in the images of fractional anisotropic values, DEC picture could clearly show the direct influence of the infarcted site on the white matter fibers. The fractional anisotropic values in different white matter structure of the same side were significantly different in the control group （t=-3.12, P 〈 0.05）, and the reconstructed images fractional anisotropic values and DEC picture could show most of the main white matter fibrous bands. The fractional anisotropic values of the infarcted sites were significantly lower than the contralateral ones in the patient group （t=-5.570, P 〈 0.01）. ② The reconstructed bilateral corticospinal tracts showed that the anatomic forms of the contralateral corticospinal tract of the patients were almost identical to those of normal people, it started from precentral gyrus, downward to the nternal capsule, and extended to pontine and medulla oblongata, each fibrous band was continuous, and the form had good consistency. Because of the involvement of infarction of different severity, the ipsilateral corticospinal tract manifested as continuous interruption and the loss of consistent anatomic structural form. The involved severity of corticospinal tract had significant correlation with that of muscle strength of the ipsilateral hand （r=-1.30, P 〈 0.01）.CONCLUSION： ① DTI can display the direction and distribution of cerebral white matter fibrous bands.② DTI images of fractional anisotropic values and DEC can show the directions and anisotropic degree of white matter fibers in the infarcted sites of stroke patients. ③ The three-dimensional images of fibrous bands can show the conditions of pyramidal tracts more directly. ④ The damaged severity of corticospinal tracts is correlated with that of muscle strength.展开更多
BACKGROUND： About more than three fourth of patients with stroke have motor dysfunction at different degrees, especially hand motor dysfunction. Functional magnetic resonance imaging （fMRI） provides very reliable v...BACKGROUND： About more than three fourth of patients with stroke have motor dysfunction at different degrees, especially hand motor dysfunction. Functional magnetic resonance imaging （fMRI） provides very reliable visible evidence for studying central mechanism of motor dysfunction after stroke, and has guiding and applicable value for clinical therapy. OBJECTIVE： To observe the activation of motor-related cortex of patients with acute ischemic stroke with functional magnetic resonance imaging, and analyze the relationship between brain function reconstruction and motor restoration after stroke. DESIGN ： A contrast observation SETTING： Medical Imaging Center, Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA. PARTICIPANTS ： Nine patients with acute ischemic stroke who suffered from motor dysfunction and received the treatment in the Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA between August and December 2005 were recruited, serving as experimental group. The involved patients including 5 male and 4 female, aged 16 to 87 years, all met the diagnostic criteria of cerebrovascular disease revised by The Fourth National Conference on Cerebrovascular Disease, mainly presenting paralysis in clinic, and underwent fMRI. Another 9 right handed persons matched in age and gender who simultaneously received healthy body examination were recruited, serving as control group. All the subjects were informed of the detected items. METHODS ： ①Muscular strength of patients of the experimental group was evaluated according to Brunnstrom grading muscular strength （Grade Ⅰ -Ⅳ）. ②Passive finger to finger motion was used as the mission （alternate style of quiescence, left hand motion and quiescence, nght hand motion was repeated 3 times, serving as 1 sequence, 20 s per block and 20 s time interval. The whole process of scanning was 260 s）, and subjects of 2 groups were given Bold-fMRI examination with GEl .5T double gradient 16-channel magnetic resonance imaging system. All the data were given off-line management, and fMRI was treated with SPM2 softwere. The activation of passive finger-to-finger motion-related cortex of subjects in 2 groups was observed. ③ Results of fMRI of subjects in 2 groups were compared. The size of activation region of brain and signal intensity were measured and unilateral index was calculated. The data of activation region of cerebral hemisphere of different sides at finger motion were given statistical analysis of unilateral index. Differences among unilateral indexes at hand motion were compared between intact and affected hands of patients in experimental group. The relationship between unilateral index and muscular strength of affected hands at affected hand motion in patients of the experimental group was performed Spearman correlation analysis. MAIN OUTCOME MEASURES： ① The activation of motion-related cortex passive finger-to-finger motion between handedness and non-handedness was detected with functional magnetic resonance imaging of subjects in 2 groups. ②Relationship between unilateral index and muscular strength of subjects of experimental group at affected hand motion. RESULTS： Nine patients with ischemic stroke and 9 controls all participated in the final result analysis. ① Passive fMRI detection results between handedness and non-handedness of controls： Right-handed finger-to-finger motion of subjects of control group mainly activated contralateral sensonmotor cortex, and left-handed finger-to-finger motion not only activated above-mentioned brain region, but also activated supplementary motor area （SMA） of contralateral brain region; ②In the experimental group, sensorimotor cortex of contralateral hemisphere was activated at affected hand motion, and homolateral posterior parietal cortex （PPC）was also obviously activated. Bilateral sensonmotor cortex was activated at affected hand motion in 2 patients, and homolateral activation area was larger than contralateral one. At intact hand motion, contralateral sensorimotor cortex was activated, but no obvious homolateral activation area was found. ③ Correlation of unilateral index with muscular strength： Passive finger-to-finger fMRI （ between affected and intact hands of subjects of experimental group： Unilateral index at passive single finger motion of affected and intact hand of subjects of experimental group was -0.018±0.01 and 0.319±0.187, respectively, with significant difference （t=4.059, P 〈 0.01 ）. Unilateral index was significantly positively correlated with the muscular strength of affected hand at affected hand motion（r=0.834, P 〈 0.05）.CONCLUSION ： ①fMRI can objectively shows different activation states of motor cortex between patients with ischemic stroke and healthy controls, and brain functional compensation and recombination exist. Both primary sensorimotor cortex and SMA of bilateral hemispheres participant in affected hand motion, at the same time, parietal lobe and cortex of intact side also obviously participant in the affected hand motion. ②Correlation analysis of unilateral index and muscular strength of affected hand performed through fMRI can be used as an effective means to investigate the relationship between motion rehabilitation and brain functional recombination after stroke.展开更多
Fatty acyl reductases(FARs)are key enzymes that participate in sex pheromone biosynthesis by reducing fatty acids to fatty alcohols.Lepidoptera typically harbor numerous FAR gene family members.Although FAR genes are ...Fatty acyl reductases(FARs)are key enzymes that participate in sex pheromone biosynthesis by reducing fatty acids to fatty alcohols.Lepidoptera typically harbor numerous FAR gene family members.Although FAR genes are involved in the biosynthesis of sex pheromones in moths,the key FAR gene of Spodoptera litura remains unclear.In this work,we predicted 30 FAR genes from the S.litura genome and identified a domain duplication within gene SlitFAR3,which exhibited high and preferential expression in the sexually mature female pheromone glands(PGs)and a rhythmic expression pattern during the scotophase of sex pheromone production.The molecular docking of SlitFAR3,as predicted using a 3D model,revealed a co-factor NADPH binding cavity and 2 substrate binding cavities.Functional expression in yeast cells combined with comprehensive gas chromatography indicated that the SlitFAR3 gene could produce fatty alcohol products.This study is the first to focus on the special phenomenon of FAR domain duplication,which will advance our understanding of biosynthesis-related genes from the perspective of evolutionary biology.展开更多
Objective:In recent years,diffusion tensor imaging (DTI) has emerged as a promising tool to study ischemic stroke. The aim of this study is to evaluate the anisotropic changes of cerebral white matter tracks in patien...Objective:In recent years,diffusion tensor imaging (DTI) has emerged as a promising tool to study ischemic stroke. The aim of this study is to evaluate the anisotropic changes of cerebral white matter tracks in patients with ischemic stroke using DTI,and investigate the correlation between corticospinal tract damage and muscle strength in such patients during acute ischemia.Method:9 patients with acute ischemic stroke and 9 healthy subjects were examined with T1 weighted magnetic resonance imaging (MRI),T2 weighted MRI and DTI. Fractional anisotropy (FA) was measured and the three-dimensional fibrous band images of bilateral corticospinal tracts were reconstructed. The muscle strength of the affected hand was assessed by Brunnstorm standard[1],which is an internationally recognized measure of movement in hemiplegic patients.Results:①In the control group,there was no significant difference in FA between the bilateral corticospinal tracts,but FA in different white matter structure of the same side was significantly different (t=3.12,P < 0.05). FA of posterior limb of internal capsule was higher than that of knee and anterior limb of internal capsule,FA of anterior limb of internal capsule was the lowest. while in the patient group,FA of the infarcted sites was significantly lower than the contralateral ones (t=5.570,P < 0.01). ②The ipsilateral corticospinal tract demonstrated continuous interruption and the loss of consistent anatomic structure. The involved severity of corticospinal tract had significant correlation with that of muscle strength of the ipsilateral hand (r=0.83,P < 0.01).Conclusion:This study shows that DTI can be used to investigate ischemic stroke and assess ischemic stroke-induced damage. The damaged severity of corticospinal tracts is correlated with that of muscle strength.展开更多
Background and Aims:Recognition of excessive activa-tion of hepatic stellate cells(HSCs)in liver fibrosis prompt-ed us to investigate the regulatory mechanisms of HSCs.We aimed to examine the role of O-GlcNAcylation m...Background and Aims:Recognition of excessive activa-tion of hepatic stellate cells(HSCs)in liver fibrosis prompt-ed us to investigate the regulatory mechanisms of HSCs.We aimed to examine the role of O-GlcNAcylation modifica-tion of alanine,serine,cysteine transporter 2(ASCT2)in HSCs and liver fibrosis.Methods:The expression of O-Glc-NAcylation modification in fibrotic mice livers and activated HSCs was analyzed by western blotting.Immunoprecipita-tion was used to assess the interaction of ASCT2 and O-Glc-NAc transferase(OGT).In addition,ASCT2 protein stability was assayed after cycloheximide(CHX)treatment.The O-GlcNAcylation site of ASCT2 was predicted and mutated by site-directed mutagenesis.Real-time PCR,immunofluores-cence,kit determinations and Seahorse assays were used to clarify the effect of ASCT2 O-GlcNAcylation on HSC glu-taminolysis and HSC activation.Western blotting,immuno-chemistry,and immunohistofluorescence were used to ana-lyze the effect of ASCT2 O-GlcNAcylation in vivo.Results:We observed significantly increased O-GlcNAcylation modi-fication of ASCT2.ASCT2 was found to interact with OGT to regulate ASCT2 stability.We predicted and confirmed that O-GlcNAcylation of ASCT2 at Thr122 site resulted in HSCs activation.We found Thr122 O-GlcNAcylation of ASCT2 me-diated membrane trafficking of glutamine transport and attenuated HSC glutaminolysis.Finally,we validated the expression and function of ASCT2 O-GlcNAcylation after in-jection of AAV8-ASCT2 shRNA in CCl4-induced liver fibrosis mice in vivo.Conclusions:Thr122 O-GlcNAcylation regu-lation of ASCT2 resulted in stability and membrane traf-ficking-mediated glutaminolysis in HSCs and liver fibrosis.Further studies are required to assess its role as a putative therapeutic target.展开更多
文摘BACKGROUND： Diffusion tensor imaging （DTI） is one of the noninvasive methods to study the morphological structure of brain white matter fibrous bands in vivo, and it has been applied primarily in clinic. DTI is acknowledged as the more effective imaging method to diagnose ultra-acute and/or acute cerebral infarction.OB_3ECTIVE： To observe the anisotropic characters of cerebral white matter fibrous bands in patients with ischemic stroke by using DTI, and investigate the correlation between the damage of corticospinal tract and muscle strength in patients with ischemic stroke at acute period.DESIGN： A case-control observationSEFIING： Department of Medical Imaging, Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA.PARTICIPANTS： Nine inpatients with injury of motor function induced by acute ischemic stroke （patient group） at 6 hours to 2 weeks after the attack were selected from the Department of Neurology, Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA from September 2005 to March 2006, and they all accorded with the present diagnostic standard for cerebrovascular disease in China. There were 5 males and 4 females, aged 16-87 years. At the same time, nine healthy right-handed physical examinees matched by age and sex with the patients were taken as the control group, and they all had no nervous disease, mental diseases, cerebrovascular abnormalities and injury history, etc. All the subjects were informed with the detected items and agreed to participate in the study.METHODS： All the 9 patients with ischemic stroke at acute period and 9 healthy subjects were examined with MRI, T1 weighted imaging, T2 weighted imaging and DTI. And the data were processed offline with dTV.II software, the images of fractional anisotropy and directional encoded color （DEC） were obtained, and the three-dimensional fibrous band images of bilateral corticospinal tracts were reconstructed. In the control group, the values of fractional anisotropy of main white matter fibrous bands were measured in the region of interest （ROI） of the anterior limb, knee and posterior limb of internal capsule. In the patient group, the values of fractional anisotropy of white matter were measured in the infarcted sites and corresponding contralateral sites of the patients. The ROI was set in bilateral cerebral peduncles to reconstruct three-dimensionally the bilateral corticospinal tracts. The muscle strength of the affected hand was assessed with Brunnstorm standard in the stroke patients.MAIN OUTCOME MEASURES ： The characters of DTI and images of the value of fractional anisotropy, and the manifestations of three-dimensional corticospinal tracts were observed in the two groups.RESULTS： All the data from the 9 patients and 9 healthy volunteers were involved in the analysis of results. In the control group, the white matter and gray matter could be distinguished clearly in the image of fractional anisotropic values, the fibers of different directions were shown by different colors in DEC picture, which clearly demonstrated the normal anatomic structure and direction of white matter fibers. In the patient group, the infarctions occurred in the gray matter or white matter could be distinguished in the images of fractional anisotropic values, DEC picture could clearly show the direct influence of the infarcted site on the white matter fibers. The fractional anisotropic values in different white matter structure of the same side were significantly different in the control group （t=-3.12, P 〈 0.05）, and the reconstructed images fractional anisotropic values and DEC picture could show most of the main white matter fibrous bands. The fractional anisotropic values of the infarcted sites were significantly lower than the contralateral ones in the patient group （t=-5.570, P 〈 0.01）. ② The reconstructed bilateral corticospinal tracts showed that the anatomic forms of the contralateral corticospinal tract of the patients were almost identical to those of normal people, it started from precentral gyrus, downward to the nternal capsule, and extended to pontine and medulla oblongata, each fibrous band was continuous, and the form had good consistency. Because of the involvement of infarction of different severity, the ipsilateral corticospinal tract manifested as continuous interruption and the loss of consistent anatomic structural form. The involved severity of corticospinal tract had significant correlation with that of muscle strength of the ipsilateral hand （r=-1.30, P 〈 0.01）.CONCLUSION： ① DTI can display the direction and distribution of cerebral white matter fibrous bands.② DTI images of fractional anisotropic values and DEC can show the directions and anisotropic degree of white matter fibers in the infarcted sites of stroke patients. ③ The three-dimensional images of fibrous bands can show the conditions of pyramidal tracts more directly. ④ The damaged severity of corticospinal tracts is correlated with that of muscle strength.
文摘BACKGROUND： About more than three fourth of patients with stroke have motor dysfunction at different degrees, especially hand motor dysfunction. Functional magnetic resonance imaging （fMRI） provides very reliable visible evidence for studying central mechanism of motor dysfunction after stroke, and has guiding and applicable value for clinical therapy. OBJECTIVE： To observe the activation of motor-related cortex of patients with acute ischemic stroke with functional magnetic resonance imaging, and analyze the relationship between brain function reconstruction and motor restoration after stroke. DESIGN ： A contrast observation SETTING： Medical Imaging Center, Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA. PARTICIPANTS ： Nine patients with acute ischemic stroke who suffered from motor dysfunction and received the treatment in the Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA between August and December 2005 were recruited, serving as experimental group. The involved patients including 5 male and 4 female, aged 16 to 87 years, all met the diagnostic criteria of cerebrovascular disease revised by The Fourth National Conference on Cerebrovascular Disease, mainly presenting paralysis in clinic, and underwent fMRI. Another 9 right handed persons matched in age and gender who simultaneously received healthy body examination were recruited, serving as control group. All the subjects were informed of the detected items. METHODS ： ①Muscular strength of patients of the experimental group was evaluated according to Brunnstrom grading muscular strength （Grade Ⅰ -Ⅳ）. ②Passive finger to finger motion was used as the mission （alternate style of quiescence, left hand motion and quiescence, nght hand motion was repeated 3 times, serving as 1 sequence, 20 s per block and 20 s time interval. The whole process of scanning was 260 s）, and subjects of 2 groups were given Bold-fMRI examination with GEl .5T double gradient 16-channel magnetic resonance imaging system. All the data were given off-line management, and fMRI was treated with SPM2 softwere. The activation of passive finger-to-finger motion-related cortex of subjects in 2 groups was observed. ③ Results of fMRI of subjects in 2 groups were compared. The size of activation region of brain and signal intensity were measured and unilateral index was calculated. The data of activation region of cerebral hemisphere of different sides at finger motion were given statistical analysis of unilateral index. Differences among unilateral indexes at hand motion were compared between intact and affected hands of patients in experimental group. The relationship between unilateral index and muscular strength of affected hands at affected hand motion in patients of the experimental group was performed Spearman correlation analysis. MAIN OUTCOME MEASURES： ① The activation of motion-related cortex passive finger-to-finger motion between handedness and non-handedness was detected with functional magnetic resonance imaging of subjects in 2 groups. ②Relationship between unilateral index and muscular strength of subjects of experimental group at affected hand motion. RESULTS： Nine patients with ischemic stroke and 9 controls all participated in the final result analysis. ① Passive fMRI detection results between handedness and non-handedness of controls： Right-handed finger-to-finger motion of subjects of control group mainly activated contralateral sensonmotor cortex, and left-handed finger-to-finger motion not only activated above-mentioned brain region, but also activated supplementary motor area （SMA） of contralateral brain region; ②In the experimental group, sensorimotor cortex of contralateral hemisphere was activated at affected hand motion, and homolateral posterior parietal cortex （PPC）was also obviously activated. Bilateral sensonmotor cortex was activated at affected hand motion in 2 patients, and homolateral activation area was larger than contralateral one. At intact hand motion, contralateral sensorimotor cortex was activated, but no obvious homolateral activation area was found. ③ Correlation of unilateral index with muscular strength： Passive finger-to-finger fMRI （ between affected and intact hands of subjects of experimental group： Unilateral index at passive single finger motion of affected and intact hand of subjects of experimental group was -0.018±0.01 and 0.319±0.187, respectively, with significant difference （t=4.059, P 〈 0.01 ）. Unilateral index was significantly positively correlated with the muscular strength of affected hand at affected hand motion（r=0.834, P 〈 0.05）.CONCLUSION ： ①fMRI can objectively shows different activation states of motor cortex between patients with ischemic stroke and healthy controls, and brain functional compensation and recombination exist. Both primary sensorimotor cortex and SMA of bilateral hemispheres participant in affected hand motion, at the same time, parietal lobe and cortex of intact side also obviously participant in the affected hand motion. ②Correlation analysis of unilateral index and muscular strength of affected hand performed through fMRI can be used as an effective means to investigate the relationship between motion rehabilitation and brain functional recombination after stroke.
基金China Agriculture Research System of MOF and MARA(CARS-24-C-03)National Key R&D Program of China(Grant no.2019YFD1002100).
文摘Fatty acyl reductases(FARs)are key enzymes that participate in sex pheromone biosynthesis by reducing fatty acids to fatty alcohols.Lepidoptera typically harbor numerous FAR gene family members.Although FAR genes are involved in the biosynthesis of sex pheromones in moths,the key FAR gene of Spodoptera litura remains unclear.In this work,we predicted 30 FAR genes from the S.litura genome and identified a domain duplication within gene SlitFAR3,which exhibited high and preferential expression in the sexually mature female pheromone glands(PGs)and a rhythmic expression pattern during the scotophase of sex pheromone production.The molecular docking of SlitFAR3,as predicted using a 3D model,revealed a co-factor NADPH binding cavity and 2 substrate binding cavities.Functional expression in yeast cells combined with comprehensive gas chromatography indicated that the SlitFAR3 gene could produce fatty alcohol products.This study is the first to focus on the special phenomenon of FAR domain duplication,which will advance our understanding of biosynthesis-related genes from the perspective of evolutionary biology.
文摘Objective:In recent years,diffusion tensor imaging (DTI) has emerged as a promising tool to study ischemic stroke. The aim of this study is to evaluate the anisotropic changes of cerebral white matter tracks in patients with ischemic stroke using DTI,and investigate the correlation between corticospinal tract damage and muscle strength in such patients during acute ischemia.Method:9 patients with acute ischemic stroke and 9 healthy subjects were examined with T1 weighted magnetic resonance imaging (MRI),T2 weighted MRI and DTI. Fractional anisotropy (FA) was measured and the three-dimensional fibrous band images of bilateral corticospinal tracts were reconstructed. The muscle strength of the affected hand was assessed by Brunnstorm standard[1],which is an internationally recognized measure of movement in hemiplegic patients.Results:①In the control group,there was no significant difference in FA between the bilateral corticospinal tracts,but FA in different white matter structure of the same side was significantly different (t=3.12,P < 0.05). FA of posterior limb of internal capsule was higher than that of knee and anterior limb of internal capsule,FA of anterior limb of internal capsule was the lowest. while in the patient group,FA of the infarcted sites was significantly lower than the contralateral ones (t=5.570,P < 0.01). ②The ipsilateral corticospinal tract demonstrated continuous interruption and the loss of consistent anatomic structure. The involved severity of corticospinal tract had significant correlation with that of muscle strength of the ipsilateral hand (r=0.83,P < 0.01).Conclusion:This study shows that DTI can be used to investigate ischemic stroke and assess ischemic stroke-induced damage. The damaged severity of corticospinal tracts is correlated with that of muscle strength.
基金the Leading Talent Project of Ji-angsu Province Traditional Chinese Medicine(SLJ0216)the National Natural Science Foundation of China(82073914,81870423)+2 种基金the Major Project of the Natural Science Research of Jiangsu Higher Education Institutions(19KJA310005)the Postgraduate Research&Practice Innovation Program of Jiangsu Province,Grant/Award Number:KYCX20_1493the Joint Project of Jiangsu Key Laboratory for Pharmacol-ogy and Safety Evaluation of Chinese Materia Medica and Yangtze River Pharmaceutical(JKLPSE202005)。
文摘Background and Aims:Recognition of excessive activa-tion of hepatic stellate cells(HSCs)in liver fibrosis prompt-ed us to investigate the regulatory mechanisms of HSCs.We aimed to examine the role of O-GlcNAcylation modifica-tion of alanine,serine,cysteine transporter 2(ASCT2)in HSCs and liver fibrosis.Methods:The expression of O-Glc-NAcylation modification in fibrotic mice livers and activated HSCs was analyzed by western blotting.Immunoprecipita-tion was used to assess the interaction of ASCT2 and O-Glc-NAc transferase(OGT).In addition,ASCT2 protein stability was assayed after cycloheximide(CHX)treatment.The O-GlcNAcylation site of ASCT2 was predicted and mutated by site-directed mutagenesis.Real-time PCR,immunofluores-cence,kit determinations and Seahorse assays were used to clarify the effect of ASCT2 O-GlcNAcylation on HSC glu-taminolysis and HSC activation.Western blotting,immuno-chemistry,and immunohistofluorescence were used to ana-lyze the effect of ASCT2 O-GlcNAcylation in vivo.Results:We observed significantly increased O-GlcNAcylation modi-fication of ASCT2.ASCT2 was found to interact with OGT to regulate ASCT2 stability.We predicted and confirmed that O-GlcNAcylation of ASCT2 at Thr122 site resulted in HSCs activation.We found Thr122 O-GlcNAcylation of ASCT2 me-diated membrane trafficking of glutamine transport and attenuated HSC glutaminolysis.Finally,we validated the expression and function of ASCT2 O-GlcNAcylation after in-jection of AAV8-ASCT2 shRNA in CCl4-induced liver fibrosis mice in vivo.Conclusions:Thr122 O-GlcNAcylation regu-lation of ASCT2 resulted in stability and membrane traf-ficking-mediated glutaminolysis in HSCs and liver fibrosis.Further studies are required to assess its role as a putative therapeutic target.
