1.Accuracy of multivariate discriminant analysis versus fibrosis-4 in evaluating the liver fibrosis degree in patients with chronic HBV infection
Hongyu LIU ; Xiaoting LI ; Jianning JIANG ; Chao JIN ; Cailian CAI ; Keshan WANG ; Fangpeng LING ; Bingling FAN ; Minghua SU
Journal of Clinical Hepatology 2025;41(4):677-683
ObjectiveTo investigate the accuracy of multiple discriminant analysis (MDA) versus fibrosis-4 (FIB-4) in assessing liver fibrosis degree in patients with HBV infection, as well as the possibility of MDA as an indicator for disease progression. MethodsA total of 263 patients with HBV infection who underwent liver biopsy in The First Affiliated Hospital of Guangxi Medical University from April 2010 to April 2024 were included, and their clinical data were collected. According to the results of pathological examination, they were divided into non-significant fibrosis group (F<2) with 126 patients and significant fibrosis group (F≥2) with 137 patients. The correlation of MDA and FIB-4 with liver fibrosis degree was analyzed, and MDA and FIB-4 were compared in terms of their accuracy in assessing significant liver fibrosis. A total of 62 patients completed follow-up, and according to the presence or absence of progression to liver cirrhosis at the last follow-up visit, they were divided into progressive group with 21 patients and non-progressive group with 41 patients; the efficacy of MDA and FIB-4 in diagnosing disease progression was analyzed and compared. The independent-samples t test was used for comparison of normally distributed continuous data between groups, and the Mann-Whitney U test was used for comparison of non-normally distributed continuous data between groups; the Kruskal-Wallis H test was used for comparison between multiple groups, and the Bonferroni method was used for further comparison between two groups. The chi-square test was used for comparison of categorical data. The Spearman’s correlation coefficient was used for correlation analysis. The Wilcoxon signed rank sum test was used for the analysis of baseline data and data at the end of follow-up, and the binary Logistic regression analysis was used to investigate the influencing factors for progression to liver cirrhosis. The receiver operating characteristic (ROC) curve was used to investigate the diagnostic efficacy of indicators, the Z-test was used for comparison of the area under the ROC curve (AUC), and the paired chi-square test was used for comparison of the sensitivity, specificity, and accuracy of the two indicators. ResultsThe correlation coefficient between FIB-4 and liver fibrosis degree was 0.378, while the correlation coefficient between MDA and liver fibrosis degree was -0.325 (both P<0.001). FIB-4 had an AUC of 0.688, a sensitivity of 64.96%, a specificity of 68.87%, a positive predictive value of 67.42%, a negative predictive value of 63.36%, an accuracy of 65.40%, and a cut-off value of 1.01, while MDA had an AUC of 0.653, a sensitivity of 52.55%, a specificity of 78.57%, a positive predictive value of 72.73%, a negative predictive value of 60.37%, an accuracy of 65.02%, and a cut-off value of 0.29, suggesting that compared with FIB-4, MDA had a lower sensitivity (P=0.004) and a higher specificity (P=0.001). The progressive group had a significantly higher age than the non-progressive group at baseline (t=2.611, P=0.011). For the progressive group, there was an increase in FIB-4 and a reduction in MDA from baseline to the end of follow-up (both P<0.001), while the non-progressive group showed no significant changes (both P>0.05). The multivariate Logistic regression analysis showed that aspartate aminotransferase (odds ratio [OR]=0.940, 95% confidence interval [CI]: 0.885 — 0.998, P<0.05) and MDA (OR=0.445, 95%CI: 0.279 — 0.710, P<0.001) were independent influencing factors for disease progression. MDA had an AUC of 0.893 and an optimal cut-off value of -0.01 in diagnosing the disease progression of liver cirrhosis. ConclusionMDA has a comparable accuracy to FIB-4 in the diagnosis of significant liver fibrosis, and MDA<-0.01 has a high accuracy in diagnosing the progression of liver fibrosis to liver cirrhosis, which can help to reduce the need for liver biopsy in clinical practice.
2.Progress in the regulation of mammalian embryonic development and reproduction by bone morphogenetic proteins.
Hongyu JIA ; Honghong HE ; Peng WANG ; Xiaoxiao HUANG ; Wenyi CAI ; Yaying WANG ; Jian LI ; Daoliang LAN ; Huizhu ZHANG
Chinese Journal of Biotechnology 2025;41(7):2534-2544
Bone morphogenetic proteins (BMPs) are multifunctional growth factors of the transforming growth factor β (TGF-β) superfamily. They regulate steroid secretion from mammalian granulosa cells, promote granulosa cell survival and proliferation, and inhibit follicular atresia, luteinization, and granulosa cell apoptosis, thereby promoting the development and maturation of mammalian follicles. At the same time, BMPs play an important role in embryonic morphogenesis, induction of uterine receptivity, and blastocyst attachment. This paper describes the effects of BMPs on mammalian follicular and embryonic development and the roles of BMPs in female reproduction, focusing on the process in which BMPs promote follicular maturation by regulating steroid secretion from granulosa cells during mammalian oocyte maturation. This review aims to provide a reference for further research on mammalian oocyte culture and improvement of reproductive efficiency in female animals.
Animals
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Embryonic Development/drug effects*
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Female
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Bone Morphogenetic Proteins/pharmacology*
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Reproduction/physiology*
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Humans
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Granulosa Cells/cytology*
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Oocytes
3.Effectiveness of fibrosis-4 versus aspartate aminotransferase-to-platelet ratio index in evaluating liver fibrosis degree in patients with chronic HBV infection
Xiaoting LI ; Bobin HU ; Hongyu LIU ; Chao JIN ; Cailian CAI ; Keshan WANG ; Yanchun WEI ; Jianning JIANG ; Minghua SU
Journal of Clinical Hepatology 2024;40(12):2424-2429
ObjectiveTo investigate the performance of fibrosis-4 (FIB-4) versus aspartate aminotransferase-to-platelet ratio index (APRI) in predicting advanced liver fibrosis and disease progression in patients with chronic HBV infection. MethodsA total of 497 patients with chronic HBV infection who underwent liver biopsy in The First Affiliated Hospital of Guangxi Medical University from February 2013 to December 2022 were enrolled, among whom 404 were enrolled in a retrospective study and 75 were enrolled in a prospective study. Related indicators were collected, including demographic features (sex and age), biochemical indices (alanine aminotransferase [ALT] and aspartate aminotransferase [AST]), and platelet count, and FIB-4 and APRI were calculated. The Mann-Whitney U test was used for comparison of non-normally distributed continuous data between two groups, and the Kruskal-Wallis H test was used for comparison between multiple groups; the chi-square test was used for comparison of categorical data between groups. The area under the ROC curve (AUC) was used to assess the ability of APRI and FIB-4 in evaluating liver fibrosis degree and disease progression in patients with chronic HBV infection. ResultsIn the retrospective analysis, compared with the FIB-4<2.67 group, the FIB-4≥2.67 group had a significantly higher proportion of the patients who were diagnosed with liver cirrhosis or hepatocellular carcinoma (66.19% vs 47.54%, χ²=12.75, P<0.001). The medians of FIB-4 and APRI increased significantly with liver fibrosis degree from F0 to F4 (H=42.5 and 35.9, both P<0.001). As for the fibrosis stage of F0-F4, the median of FIB-4 was significantly higher than that of APRI in the patients with the same fibrosis stage (H=59.71, P<0.001). FIB-4 and APRI had a similar AUC for predicting stage F3 fibrosis (0.67 vs 0.65, Z=0.71, P=0.480), while FIB-4 had a higher AUC for predicting stage F4 fibrosis than APRI (0.72 vs 0.64, Z=10.50, P<0.001). In the prospective study cohort, FIB-4 and APRI showed an increasing trend over time in predicting disease progression (chronic hepatitis B to liver cirrhosis), with an AUC of 0.718 (95% confidence interval [CI]: 0.476 — 0.760) and 0.555 (95%CI: 0.408 — 0.703), respectively, and FIB-4 had a significantly higher accuracy than APRI in predicting disease progression (χ2=12.44, P<0.001). ConclusionFIB-4 and APRI can be used to evaluate advanced liver fibrosis (F3 and F4) and predict disease progression, and FIB-4 is superior to APRI in certain aspects.
4.Mechanism of astragaloside IV promoting bone marrow EPCs mobilization in diabetic ulcer rats
Luyao ZHANG ; Shimin CAI ; Xi ZHANG ; Xiaoqin SONG ; Xiaoling ZOU ; Yuting XIAO ; Ying YANG ; Yang WEI ; Hongyu HUANG ; Wu XIONG
Journal of Chinese Physician 2024;26(3):376-381
Objective:To investigate the effect of astragaloside IV (AS-IV) regulating the signal axis of stromal cell-derived factor-1α (SDF-1α)/CXC chemokine receptor 4 (CXCR4) on the mobilization of bone marrow endothelial progenitor cells (EPCs) to peripheral blood in diabetes skin ulcer (DSU) rats.Methods:Twenty four SPF grade male Sprague Dawley (SD) rats were selected to make the model of type 2 diabetes rats by intraperitoneal injection of 30 mg/kg 1% (plastid ratio) streptozotocin, and then round full-thickness skin with a diameter of 2 cm was cut on both sides of the waist and back to make the skin ulcer model of diabetes rats. After that, they were randomly divided into AS-IV group (50 mg/kg AS-IV), blocker group (50 mg/kg AS-IV+ 5 mg/kg AMD3100) and model group. At the same time, a blank group ( n=8) was set up, The drug was administered via intraperitoneal injection, and the model group and blank group were treated with 0.9% NaCl of equal volume. On the 10th day, peripheral blood, femoral bone marrow, and wound neovascularization tissues of rats were collected. The number of EPCs in peripheral blood of each group of rats was measured by flow cytometry, and the protein expression of SDF-1α and CXCR4 in peripheral blood, femoral bone marrow, and wound neovascularization tissues of rats was detected by enzyme-linked immunosorbent assay (ELISA); At the same time, the wound healing rates of each group were tested. Results:On the 10th and 21st day after modeling, the wound healing rate of each group of rats was compared. The blank group healed the fastest, while the model group healed the slowest. The AS-IV group had better healing than the model group and the blocker group, and the difference was statistically significant (all P<0.05). On the 10th day after modeling, the positive rates of peripheral blood EPCs in the white group, AS-IV group, and blocker group were significantly higher than those in the model group (all P<0.05), while the positive rates of peripheral blood EPCs in the blocker group were significantly lower than those in the AS-IV group (all P<0.05). On the 10th day after modeling, the protein expression of SDF-1α and CXCR4 in the wound, serum, and bone marrow of the model group was the lowest, while the protein expression in the blank group was the highest (all P<0.05). The protein expression of SDF-1α and CXCR4 in the wound, serum, bone marrow of the AS-IV group was significantly higher than that of the blocker group and model group, and the difference was statistically significant (all P<0.05). Conclusions:Astragaloside IV can promote the mobilization and migration of endothelial progenitor cells from bone marrow to peripheral blood in diabetes ulcer rats by regulating SDF-1α/CXCR4 signal axis, and can participate in angiogenesis of diabetes ulcer wounds as seed cells to promote the healing of diabetes skin ulcers.
5.Analysis of risk factors for death after acute Stanford type A aortic dissection compli-cated with organ malperfusion
Haiyan XIE ; Hongyu LI ; Juan CHEN ; Yanli DENG ; Chun CAI ; Wuyun JIANG
Chinese Journal of Arteriosclerosis 2024;32(3):217-227
Aim To investigate the risk factors of death after acute Stanford type A aortic dissection(ATAAD)complicated with malperfusion syndrome(MPS).Methods 244 patients with ATAAD complicated with MPS who ad-mitted to Nanchong Central Hospital from June 2020 to June 2023 were selected as the study objects.The postoperative survival of the patients was followed up and they were classified into survival group(156 cases)and death group(88 ca-ses).After propensity score matching(PSM)was applied in 1 ∶1 matching,there were 54 cases in both groups.Uni-variate and Logistic regression analysis was performed to analyze the risk factors of postoperative death in patients with ATA-AD complicated with MPS.Area under curve(AUC)of receiver operating characteristics(ROC)was used to analyze the prognosis of ATAAD complicated with MPS.The prediction model was established by using the regression equation y=1-1/(1+e-z)and the stability of the model was verified by cross-checking method.Results After matching,compared with the survival group(n=54),in the death group(n=54),the proportion of sex(male),the proportion of alcohol con-sumption,acute physiology and chronic health status Ⅱ(APACHE Ⅱ)score,sequential organ failure(SOFA)score,al-anine aminotransferase(ALT),aspartate aminotransferase(AST),total serum bilirubin(TSB),cholinesterase,serum creatinine(SCr),blood urea nitrogen(BUN),N-terminal pro-brain natriuretic peptide(NT-proBNP),D-dimer(D-D),white blood cell(WBC),neutrophile granulocyte(NEU),fibrinogen degradation product(FDP),platelet(PLT),fi-brinogen(FIB),C-reactive protein(CRP),hypersensitive troponin,operation time,ICU stay time,ventilator stay time,hospital stay,distal extremity hypoperfusion,renal hypoperfusion were significantly increased(P<0.05).Logistic analy-sis displayed that gender(male),history of drinking,NT-proBNP ≥271.86 ng/L,D-D≥0.74 mg/L and NEU≥13.06× 109 L-1 were independent risk factors in ATAAD patients complicated with MPS for postoperative death(P<0.05).The combination of NT-proBNP,D-D,gender(male),alcohol drinking history and NEU(referred to as"five factors")had the highest value in predicting ATAAD patients with MPS.The AUC of its ROC curve was 0.979(95%CI:0.937~0.984),the sensitivity was 94.3%,and the specificity was 91.8%,which was higher than the independent predictor.The best critical value predicted by the five factors was 5.02.The survival rate of the group>5.02 was significantly high-er than that of the group ≤5.02.Log Rank test P<0.01.A prediction model was established based on the important factors of postoperative death in ATAAD patients with MPS.The results showed that the model had good prediction accu-racy.Conclusion NT-proBNP≥271.86 ng/L,D-D≥0.74 mg/L,gender(male),history of alcohol consumption,and NEU≥×109 L-1 were independent risk factors for long-term prognosis in patients with ATAAD combined with MPS,and their combined application could effectively increase the accuracy of prognosis assessment.
6.Comparative study of multi-modal MRI automatic post-processing software based on multicenter data with patients of acute ischemic stroke
Mingming WANG ; Hongyu GAO ; Zhenying CAI ; Yuan RAO ; Shuangxing HOU ; Yu LUO ; Qi YANG
Chinese Journal of Radiology 2024;58(6):633-639
Objective:To investigate the consistency of domestic F-STROKE, NeuBrainCARE MRI automatic post-processing software and RAPID MRI automatic post-processing software in the output of infarction core area volume, time-to-maximum volume and ischemic penumbra volume in patients with acute ischemic stroke.Methods:The research was cross-sectional. The clinical and imaging data of patients with acute ischemic stroke from January 2016 to March 2021 were retrospectively collected, including 149 cases from Shanghai Fourth People′s Hospital Affiliated to Tongji University (Center 1), 120 cases from Langfang Changzheng Hospital of Hebei Province (Center 2), and 45 cases from Wuzhou Workers Hospital (Center 3). All patients underwent diffusion weighted imaging (DWI) and dynamic magnetic sensitivity contrast-perfusion weighted imaging (DSC-PWI). RAPID, F-STROKE and NeuBrainCARE automatic post-processing software were used to perform automatic post-processing analysis of MRI images of all patients with acute ischemic stroke. The infarct core (apparent diffusion coefficient<620×10 -6 mm 2/s) volume, time-to-maximum (T max>6 s) volume and the ischemic penumbra (PWI-DWI mismatch) volume were output. The Wilcoxon test was used to analyze the difference between F-STROKE, NeuBrainCARE, and RAPID software outputs of infarct core volume, time to maximum peak volume, and ischemic penumbra volume. Bland-Altman and intraclass correlation coefficient ( ICC) were used to analyze the consistency of the infarct core volume, time-to-maximum volume and ischemic penumbra volume output by F-STROKE, NeuBrainCARE and RAPID software. Results:There were statistically significant differences in the core infarct volume between F-STROKE and RAPID software, NeuBrainCARE and RAPID software ( Z=-10.17, -5.43, both P<0.001). There were significant differences in the time-to-maximum volume between F-STROKE and RAPID software, NeuBrainCARE and RAPID software ( Z=-3.17, -5.51, both P<0.05). There was no significant difference in the ischemic penumbra volume between F-STROKE software and RAPID software ( Z=-1.43, P=0.153), and there was significant difference in the ischemic penumbra volume between NeuBrainCARE software and RAPID software ( Z=-6.45, P<0.05). Bland-Altman analysis showed that the values within the limits of agreement accounted for more than 93.31% of all point values. ICC analysis showed high agreement between F-STROKE, NeuBrainCARE, and RAPID software outputs of infarct core volume, time to maximum peak volume, and ischemic penumbra volume ( ICC>0.6). Conclusion:Domestic F-STROKE software, NeuBrainCARE software and RAPID software have good consistency in evaluating the infarct core volume, time-to-maximum volume and ischemic penumbra volume in patients with acute ischemic stroke, which is worthy of clinical promotion.
7.JNK/CCl2 pathway induces macrophage recruitment and promotes allergic airway inflammation in juvenile rats induced by PM(2.5)particulate matter exposure
Hongxia CEN ; Siming CAI ; Hongyu JIANG ; Zhaomei LIAO
Chinese Journal of Immunology 2024;40(4):720-725
Objective:To investigate the role and mechanism of PM(2.5)exposure on airway inflammation in juvenile rats based on macrophage recruitment induced by JNK/CCl2 signaling pathway.Methods:A total of 50 juvenile SD rats were randomly divided into 5 groups(n=10).The control group received no treatment,the PM(2.5)group received PM(2.5)particulate matter expo-sure,and the PM(2.5)+Anisomycin group received PM(2.5)exposure and Anisomycin,an activator of JNK,intravenously.Rats in the PM(2.5)+SP600125 group received PM(2.5)exposure and intravenous administration of the JNK inhibitor SP600125,and rats in the PM(2.5)+Pirfenidone group received PM(2.5)exposure and intravenous administration of Pirfenidone,a CCl2 inhibitor.The rats were euthanized and lung tissue was harvested.JNK,phosphorylated JNK(p-JNK)and CCl2 protein expressions were detected by Western blot.Hematoxylin-eosin(HE)staining was used to detect the pathological changes of lung airway tissue and score the pulmo-nary bronchial inflammation.The number of macrophages in alveolar lavage fluid was analyzed by flow cytometry.The levels of IL-6,IL-1β,and TNF-α in alveolar lavage fluid were determined by ELISA.Results:The expression levels of JNK,p-JNK,and CCl2 among all groups(F=205.296,950.408,260.019;all P<0.001)and macrophage content(F=48.414;P<0.001),pulmonary bronchial inflammation score(F=101.703;P<0.001)and IL-6(H=44.890;P<0.001),IL-1β(H=42.071;P<0.001),TNF-α(F=297.154;P<0.001)were statistically significant.Compared with the control group,the expressions of JNK/CCl2 pathway proteins JNK,p-JNK,and CCl2 in PM(2.5)group were significantly up-regulated(all P<0.05),while the content of macrophages was increased(P<0.05),and the pulmonary and bronchial inflammation score was significantly increased(P<0.05).The levels of IL-6,IL-1β,and TNF-α were up-regulated(all P<0.05).Compared with PM(2.5)group,the content of macrophages in PM(2.5)+Anisomycin group was sig-nificantly increased(P<0.05),the pulmonary bronchial inflammation score was significantly increased(P<0.05),and the levels of IL-6,IL-1β,and TNF-α were increased(all P<0.05).The expression levels of JNK,p-JNK,and CCl2 were increased(all P<0.05).Compared with PM(2.5)group,the content of macrophages in PM(2.5)+SP600125 group and PM(2.5)+Pirfenidone group were signifi-cantly decreased(P<0.05),and the pulmonary bronchial inflammation score was significantly decreased(P<0.05).In addition,the levels of IL-6,IL-1β,and TNF-α were significantly decreased(all P<0.05).Compared with PM(2.5)group,the expression levels of JNK,p-JNK,and CCl2 in PM(2.5)+SP600125 group were down-regulated(all P<0.05),and the expression level of CCl2 in PM(2.5)+Pirfenidone group was down-regulated(all P<0.05).Conclusion:JNK/CCl2 pathway induces macrophage recruitment and pro-motes allergic airway inflammation induced by PM(2.5)particulate matter exposure in juvenile rats.
8.PDZD8 Augments Endoplasmic Reticulum-Mitochondria Contact and Regulates Ca2+ Dynamics and Cypd Expression to Induce Pancreatic β-Cell Death during Diabetes
Yongxin LIU ; Yongqing WEI ; Xiaolong JIN ; Hongyu CAI ; Qianqian CHEN ; Xiujuan ZHANG
Diabetes & Metabolism Journal 2024;48(6):1058-1072
Background:
Diabetes mellitus (DM) is a chronic metabolic disease that poses serious threats to human physical and mental health worldwide. The PDZ domain-containing 8 (PDZD8) protein mediates mitochondria-associated endoplasmic reticulum (ER) membrane (MAM) formation in mammals. We explored the role of PDZD8 in DM and investigated its potential mechanism of action.
Methods:
High-fat diet (HFD)- and streptozotocin-induced mouse DM and palmitic acid (PA)-induced insulin 1 (INS-1) cell models were constructed. PDZD8 expression was detected using immunohistochemistry, quantitative real-time polymerase chain reaction (qRT-PCR), and Western blotting. MAM formation, interactions between voltage-dependent anion-selective channel 1 (VDAC1) and inositol 1,4,5-triphosphate receptor type 1 (IP3R1), pancreatic β-cell apoptosis and proliferation were detected using transmission electron microscopy (TEM), proximity ligation assay (PLA), terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, immunofluorescence staining, and Western blotting. The mitochondrial membrane potential, cell apoptosis, cytotoxicity, and subcellular Ca2+ localization in INS-1 cells were detected using a JC-1 probe, flow cytometry, and an lactate dehydrogenase kit.
Results:
PDZD8 expression was up-regulated in the islets of HFD mice and PA-treated pancreatic β-cells. PDZD8 knockdown markedly shortened MAM perimeter, suppressed the expression of MAM-related proteins IP3R1, glucose-regulated protein 75 (GRP75), and VDAC1, inhibited the interaction between VDAC1 and IP3R1, alleviated mitochondrial dysfunction and ER stress, reduced the expression of ER stress-related proteins, and decreased apoptosis while increased proliferation of pancreatic β-cells. Additionally, PDZD8 knockdown alleviated Ca2+ flow into the mitochondria and decreased cyclophilin D (Cypd) expression. Cypd overexpression alleviated the promoting effect of PDZD8 knockdown on the apoptosis of β-cells.
Conclusion
PDZD8 knockdown inhibited pancreatic β-cell death in DM by alleviated ER-mitochondria contact and the flow of Ca2+ into the mitochondria.
9.PDZD8 Augments Endoplasmic Reticulum-Mitochondria Contact and Regulates Ca2+ Dynamics and Cypd Expression to Induce Pancreatic β-Cell Death during Diabetes
Yongxin LIU ; Yongqing WEI ; Xiaolong JIN ; Hongyu CAI ; Qianqian CHEN ; Xiujuan ZHANG
Diabetes & Metabolism Journal 2024;48(6):1058-1072
Background:
Diabetes mellitus (DM) is a chronic metabolic disease that poses serious threats to human physical and mental health worldwide. The PDZ domain-containing 8 (PDZD8) protein mediates mitochondria-associated endoplasmic reticulum (ER) membrane (MAM) formation in mammals. We explored the role of PDZD8 in DM and investigated its potential mechanism of action.
Methods:
High-fat diet (HFD)- and streptozotocin-induced mouse DM and palmitic acid (PA)-induced insulin 1 (INS-1) cell models were constructed. PDZD8 expression was detected using immunohistochemistry, quantitative real-time polymerase chain reaction (qRT-PCR), and Western blotting. MAM formation, interactions between voltage-dependent anion-selective channel 1 (VDAC1) and inositol 1,4,5-triphosphate receptor type 1 (IP3R1), pancreatic β-cell apoptosis and proliferation were detected using transmission electron microscopy (TEM), proximity ligation assay (PLA), terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, immunofluorescence staining, and Western blotting. The mitochondrial membrane potential, cell apoptosis, cytotoxicity, and subcellular Ca2+ localization in INS-1 cells were detected using a JC-1 probe, flow cytometry, and an lactate dehydrogenase kit.
Results:
PDZD8 expression was up-regulated in the islets of HFD mice and PA-treated pancreatic β-cells. PDZD8 knockdown markedly shortened MAM perimeter, suppressed the expression of MAM-related proteins IP3R1, glucose-regulated protein 75 (GRP75), and VDAC1, inhibited the interaction between VDAC1 and IP3R1, alleviated mitochondrial dysfunction and ER stress, reduced the expression of ER stress-related proteins, and decreased apoptosis while increased proliferation of pancreatic β-cells. Additionally, PDZD8 knockdown alleviated Ca2+ flow into the mitochondria and decreased cyclophilin D (Cypd) expression. Cypd overexpression alleviated the promoting effect of PDZD8 knockdown on the apoptosis of β-cells.
Conclusion
PDZD8 knockdown inhibited pancreatic β-cell death in DM by alleviated ER-mitochondria contact and the flow of Ca2+ into the mitochondria.
10.PDZD8 Augments Endoplasmic Reticulum-Mitochondria Contact and Regulates Ca2+ Dynamics and Cypd Expression to Induce Pancreatic β-Cell Death during Diabetes
Yongxin LIU ; Yongqing WEI ; Xiaolong JIN ; Hongyu CAI ; Qianqian CHEN ; Xiujuan ZHANG
Diabetes & Metabolism Journal 2024;48(6):1058-1072
Background:
Diabetes mellitus (DM) is a chronic metabolic disease that poses serious threats to human physical and mental health worldwide. The PDZ domain-containing 8 (PDZD8) protein mediates mitochondria-associated endoplasmic reticulum (ER) membrane (MAM) formation in mammals. We explored the role of PDZD8 in DM and investigated its potential mechanism of action.
Methods:
High-fat diet (HFD)- and streptozotocin-induced mouse DM and palmitic acid (PA)-induced insulin 1 (INS-1) cell models were constructed. PDZD8 expression was detected using immunohistochemistry, quantitative real-time polymerase chain reaction (qRT-PCR), and Western blotting. MAM formation, interactions between voltage-dependent anion-selective channel 1 (VDAC1) and inositol 1,4,5-triphosphate receptor type 1 (IP3R1), pancreatic β-cell apoptosis and proliferation were detected using transmission electron microscopy (TEM), proximity ligation assay (PLA), terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, immunofluorescence staining, and Western blotting. The mitochondrial membrane potential, cell apoptosis, cytotoxicity, and subcellular Ca2+ localization in INS-1 cells were detected using a JC-1 probe, flow cytometry, and an lactate dehydrogenase kit.
Results:
PDZD8 expression was up-regulated in the islets of HFD mice and PA-treated pancreatic β-cells. PDZD8 knockdown markedly shortened MAM perimeter, suppressed the expression of MAM-related proteins IP3R1, glucose-regulated protein 75 (GRP75), and VDAC1, inhibited the interaction between VDAC1 and IP3R1, alleviated mitochondrial dysfunction and ER stress, reduced the expression of ER stress-related proteins, and decreased apoptosis while increased proliferation of pancreatic β-cells. Additionally, PDZD8 knockdown alleviated Ca2+ flow into the mitochondria and decreased cyclophilin D (Cypd) expression. Cypd overexpression alleviated the promoting effect of PDZD8 knockdown on the apoptosis of β-cells.
Conclusion
PDZD8 knockdown inhibited pancreatic β-cell death in DM by alleviated ER-mitochondria contact and the flow of Ca2+ into the mitochondria.

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