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.Effect of Shenkang Injection on Podocyte Apoptosis and GRP78/CHOP Signaling Pathway in db/db Mice with Diabetic Kidney Disease Based on Endoplasmic Reticulum Stress
Yanmo CAI ; Sitong WANG ; Xin ZHOU ; Ge JIN ; Kaidong ZHOU ; Yunhua LIU ; Fengfeng ZHANG ; Xinxue ZHANG ; Zongjiang ZHAO
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(12):81-90
ObjectiveTo investigate the mechanism of Shenkang injection in delaying diabetic kidney disease by regulating endoplasmic reticulum stress and attenuating podocyte apoptosis through the Glucose regulated protein 78 ( GRP78 ) / transcription factor C / EBP homologous protein ( CHOP ) signaling pathway (GRP78/CHOP) signaling pathway. MethodsFor the animal experiment, 10 12-week-old db/m mice were selected as a normal group, and 30 12-week-old db/db mice were randomly divided into a model group, a Shenkang injection group (15.6 mL·kg-1), and a dapagliflozin group (1.6 mg·kg-1). To observe the general condition of mice, fasting blood glucose, urinary albumin/urine creatinine (ACR), and 24 h urine protein quantification were detected in each group before drug administration. After 12 weeks of drug treatment, mice were tested for fasting blood glucose, total cholesterol (TC), triglyceride (TG), low-density cholesterol (LDL), ACR, 24 h urine protein quantification, blood creatinine (SCr), and blood urea (UREA). Hematoxylin-eosin (HE) staining, periodic acid-Schiff (PAS) staining, and transmission electron microscopy were used to observe the pathologic morphology in renal tissue. Immunohistochemistry was used to detect the expressions of nephroprotective marker protein (Nephrin), glucose-regulated protein 78 (GRP78), CCAAT/enhancer-binding protein homologous protein (CHOP), B-cell lymphoma-2 (Bcl-2), and Bcl-2-associated X protein (Bax) in renal tissue. Western blot was used to detect the expressions of GRP78, CHOP, Bcl-2, Bax, and Nephrin proteins, and Real-time polymerase chain reaction (Real-time PCR) was employed to detect the expressions of Nephrin, GRP78, CHOP, Bcl-2, and Bax mRNAs in renal tissue. ResultsBefore drug administration, compared with those in the normal group, the body mass of db/db mice was significantly increased, and blood glucose, 24 h urine protein quantification, and ACR were significantly elevated in the Shenkang injection group and Dapagliflozin group (P<0.01). After 12 weeks of administration, compared with those in the model group, the general state of mice in the Shenkang injection group was significantly improved, and the body mass was decreased. The blood glucose was significantly reduced (P<0.01), and blood lipids TC, TG, and LDL were significantly decreased (P<0.05, P<0.01). The 24 h urine protein quantification and ACR were significantly decreased (P<0.05), and SCr and UREA were significantly reduced (P<0.01). Compared with those of the model group, the pathologic results of the Shenkang injection group showed that proliferation of mesangial cells, reduction of inflammatory cell infiltration, and alleviation of renal tubular vacuolization and podocyte damage were observed in renal tissue of mice. Electron microscopy showed that fusion of the pedicle protruding and thickening of the basement membrane were reduced. Immunohistochemistry results showed that the expressions of GRP78, CHOP, and Bax proteins were significantly reduced (P<0.01), and the expressions of Nephrin and Bcl-2 proteins were significantly increased (P<0.01) in renal tissue of the Shenkang injection group. Western blot results showed that the expressions of Nephrin and Bcl-2 in the Shenkang injection group were significantly increased (P<0.05, P<0.01), and the expressions of GRP78, CHOP, and Bax proteins were significantly decreased (P<0.05, P<0.01). Real-time PCR results showed that the expressions of GRP78, CHOP, and Bax mRNAs were down regulated in the Shenkang injection group (P<0.01), and the expressions of Nephrin and Bcl-2 mRNAs were up regulated (P<0.01). ConclusionShenkang injection inhibits endoplasmic reticulum stress response and podocyte apoptosis by regulating the GRP78/CHOP signaling pathway, which in turn ensures the integrity of glomerular filtration barrier, reduces the occurrence of proteinuria, improves renal function, and thus delays the progression of diabetic kidney disease.
3.Effect of Shenkang Injection on Podocyte Apoptosis and GRP78/CHOP Signaling Pathway in db/db Mice with Diabetic Kidney Disease Based on Endoplasmic Reticulum Stress
Yanmo CAI ; Sitong WANG ; Xin ZHOU ; Ge JIN ; Kaidong ZHOU ; Yunhua LIU ; Fengfeng ZHANG ; Xinxue ZHANG ; Zongjiang ZHAO
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(12):81-90
ObjectiveTo investigate the mechanism of Shenkang injection in delaying diabetic kidney disease by regulating endoplasmic reticulum stress and attenuating podocyte apoptosis through the Glucose regulated protein 78 ( GRP78 ) / transcription factor C / EBP homologous protein ( CHOP ) signaling pathway (GRP78/CHOP) signaling pathway. MethodsFor the animal experiment, 10 12-week-old db/m mice were selected as a normal group, and 30 12-week-old db/db mice were randomly divided into a model group, a Shenkang injection group (15.6 mL·kg-1), and a dapagliflozin group (1.6 mg·kg-1). To observe the general condition of mice, fasting blood glucose, urinary albumin/urine creatinine (ACR), and 24 h urine protein quantification were detected in each group before drug administration. After 12 weeks of drug treatment, mice were tested for fasting blood glucose, total cholesterol (TC), triglyceride (TG), low-density cholesterol (LDL), ACR, 24 h urine protein quantification, blood creatinine (SCr), and blood urea (UREA). Hematoxylin-eosin (HE) staining, periodic acid-Schiff (PAS) staining, and transmission electron microscopy were used to observe the pathologic morphology in renal tissue. Immunohistochemistry was used to detect the expressions of nephroprotective marker protein (Nephrin), glucose-regulated protein 78 (GRP78), CCAAT/enhancer-binding protein homologous protein (CHOP), B-cell lymphoma-2 (Bcl-2), and Bcl-2-associated X protein (Bax) in renal tissue. Western blot was used to detect the expressions of GRP78, CHOP, Bcl-2, Bax, and Nephrin proteins, and Real-time polymerase chain reaction (Real-time PCR) was employed to detect the expressions of Nephrin, GRP78, CHOP, Bcl-2, and Bax mRNAs in renal tissue. ResultsBefore drug administration, compared with those in the normal group, the body mass of db/db mice was significantly increased, and blood glucose, 24 h urine protein quantification, and ACR were significantly elevated in the Shenkang injection group and Dapagliflozin group (P<0.01). After 12 weeks of administration, compared with those in the model group, the general state of mice in the Shenkang injection group was significantly improved, and the body mass was decreased. The blood glucose was significantly reduced (P<0.01), and blood lipids TC, TG, and LDL were significantly decreased (P<0.05, P<0.01). The 24 h urine protein quantification and ACR were significantly decreased (P<0.05), and SCr and UREA were significantly reduced (P<0.01). Compared with those of the model group, the pathologic results of the Shenkang injection group showed that proliferation of mesangial cells, reduction of inflammatory cell infiltration, and alleviation of renal tubular vacuolization and podocyte damage were observed in renal tissue of mice. Electron microscopy showed that fusion of the pedicle protruding and thickening of the basement membrane were reduced. Immunohistochemistry results showed that the expressions of GRP78, CHOP, and Bax proteins were significantly reduced (P<0.01), and the expressions of Nephrin and Bcl-2 proteins were significantly increased (P<0.01) in renal tissue of the Shenkang injection group. Western blot results showed that the expressions of Nephrin and Bcl-2 in the Shenkang injection group were significantly increased (P<0.05, P<0.01), and the expressions of GRP78, CHOP, and Bax proteins were significantly decreased (P<0.05, P<0.01). Real-time PCR results showed that the expressions of GRP78, CHOP, and Bax mRNAs were down regulated in the Shenkang injection group (P<0.01), and the expressions of Nephrin and Bcl-2 mRNAs were up regulated (P<0.01). ConclusionShenkang injection inhibits endoplasmic reticulum stress response and podocyte apoptosis by regulating the GRP78/CHOP signaling pathway, which in turn ensures the integrity of glomerular filtration barrier, reduces the occurrence of proteinuria, improves renal function, and thus delays the progression of diabetic kidney disease.
4.Yishen Huashi Granules Protect Kidneys of db/db Mice via p38 MAPK Signaling Pathway
Kaidong ZHOU ; Sitong WANG ; Ge JIN ; Yanmo CAI ; Xin ZHOU ; Yunhua LIU ; Xinxue ZHANG ; Min ZHANG ; Zongjiang ZHAO
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(3):58-68
ObjectiveTo explore the mechanism of Yishen Huashi granules in alleviating renal tubular epithelial cell injury and relieving diabetic kidney disease by regulating the mitogen-activated protein kinase (MAPK) signaling pathway. MethodsThe db/db mice of 12 weeks old were randomly assigned into model , dapagliflozin (1.6 mg·kg-1), and Yishen Huashi granules (4.7 g·kg-1), and db/m mice were used as the control group. The general conditions of mice were observed, and fasting blood glucose and 24-h urinary protein and albumin-to-creatinine ratio (ACR) were measured at weeks 0 and 12 of administration. After 12 weeks of treatment, the levels of serum creatinine (SCr), blood urea (UREA), triglycerides (TG), total cholesterol (TC), and low density lipoprotein (LDL) were measured. The pathological changes in the renal tissue were observed by hematoxylin-eosin (HE) staining, Periodic acid-Schiff (PAS) staining, Mallory staining, and transmission electron microscopy. Real-time PCR was employed to determine the mRNA levels of monocyte chemotactic protein-1 (MCP-1) and CC chemokine receptor-2 (CCR2) in the renal tissue of mice. The immunohistochemical assay was employed to examine the expression of p38, phospho-p38 (p-p38), MCP-1, and CCR2 in the renal tissue of mice. Western blotting was employed to measure the protein levels of p-p38, p38, MCP-1, and CCR2 in the renal tissue of mice.HK-2 cells cultured in vitro were grouped as follows: negative control, high glucose(30 mmol·L-1), Yishen Huashi granule-containing serum, and SB203580. After 48 h of cell culture in each group, RNA were extracted and the levels of MCP-1, and CCR2 mRNA were determined by Real-time PCR,proteins were extracted and the levels of p38, p-p38, MCP-1, and CCR2 were determined by Western blot. ResultsThe in vivo experiments showed that before treatment, other groups had higher body weight, blood glucose level, 24 h urinary protein, and ACR than the control group (P<0.05,P<0.01). After 12 weeks of treatment, compared with the model group, the Yishen Huashi granules group showed improved general conditions, a decreasing trend in body weight, lowered levels of blood glucose, 24-h urinary protein, and ACR (P<0.01), reduced SCr and UREA (P<0.01), and declined levels of TC, TG, and LDL (P<0.05,P<0.01). Compared with the model group, the Yishen Huashi granules group showed alleviated damage and interstitial fibrosis in the renal tissue as well as reductions in glomerular foot process fusion and basement membrane thickening. Moreover, the Yishen Huashi granules group showed down-regulated mRNA levels of MCP-1 and CCR2 (P<0.01), reduced positive expression of p-p38, MCP-1, and CCR2 (P<0.01), and down-regulated protein levels of p-p38/p38, MCP-1, and CCR2 (P<0.05) in the renal tissue. The cell experiment showed that compared with the high glucose group, the Yishen Huashi granule-containing serum group showcased down-regulated mRNA levels of MCP-1 and CCR2 (P<0.01) and down-regulated protein levels of p-p38/p38, MCP-1, and CCR2(P<0.05,P<0.01). ConclusionYishen Huashi granules can regulate glucose-lipid metabolism, reduce 24 h urinary protein and ACR, improve the renal function, alleviate the renal tubule injury caused by high glucose, and protect renal tubule epithelial cells in db/db mice by reducing MCP-1/CCR2 activation via the p38 MAPK signaling pathway.
5.Research progress on the mechanism of action of rosmarinic acid in the prevention of cardiovascular diseases
Ke CAI ; Sheng-ru HUANG ; Fang-fang GAO ; Xiu-juan PENG ; Sheng GUO ; Feng LIU ; Jin-ao DUAN ; Shu-lan SU
Acta Pharmaceutica Sinica 2025;60(1):12-21
With the rapid development of social economy and the continuous improvement of human living standard, the incidence, fatality and recurrence rates of cardiovascular disease (CVD) are increasing year by year, which seriously affects people's life and health. Conventional therapeutic drugs have limited improvement on the disability rate, so the search for new therapeutic drugs and action targets has become one of the hotspots of current research. In recent years, the therapeutic role of the natural compound rosmarinic acid (RA) in CVD has attracted much attention, which is capable of preventing CVD by modulating multiple signalling pathways and exerting physiological activities such as antioxidant, anti-apoptotic, anti-inflammatory, anti-platelet aggregation, as well as anti-coagulation and endothelial function protection. In this paper, the role of RA in the prevention of CVD is systematically sorted out, and its mechanism of action is summarised and analysed, with a view to providing a scientific basis and important support for the in-depth exploration of the prevention value of RA in CVD and its further development as a prevention drug.
6.A novel intracoronary hypothermia device reduces myocardial reperfusion injury in pigs
Zhiqiang PEI ; Jin QIU ; Yongchao ZHAO ; Shuai SONG ; Rui WANG ; Wei LUO ; Xingxing CAI ; Bin LIU ; Han CHEN ; Jiasheng YIN ; Xinyu WENG ; Yizhe WU ; Chenguang LI ; Li SHEN ; Junbo GE
Chinese Medical Journal 2024;137(20):2461-2472
Background::Hypothermia therapy has been suggested to attenuate myocardial necrosis; however, the clinical implementation as a valid therapeutic strategy has failed, and new approaches are needed to translate into clinical applications. This study aimed to assess the feasibility, safety, and efficacy of a novel selective intracoronary hypothermia (SICH) device in mitigating myocardial reperfusion injury.Methods::This study comprised two phases. The first phase of the SICH was performed in a normal porcine model for 30 minutes ( n = 5) to evaluate its feasibility. The second phase was conducted in a porcine myocardial infarction (MI) model of myocardial ischemia/reperfusion which was performed by balloon occlusion of the left anterior descending coronary artery for 60 minutes and maintained for 42 days. Pigs in the hypothermia group ( n = 8) received hypothermia intervention onset reperfusion for 30 minutes and controls ( n = 8) received no intervention. All animals were followed for 42 days. Cardiac magnetic resonance analysis (five and 42 days post-MI) and a series of biomarkers/histological studies were performed. Results::The average time to lower temperatures to a steady state was 4.8 ± 0.8 s. SICH had no impact on blood pressure or heart rate and was safely performed without complications by using a 3.9 F catheter. Interleukin-6 (IL-6), tumor necrosis factor-α, C-reactive protein (CRP), and brain natriuretic peptide (BNP) were lower at 60 min post perfusion in pigs that underwent SICH as compared with the control group. On day 5 post MI/R, edema, intramyocardial hemorrhage, and microvascular obstruction were reduced in the hypothermia group. On day 42 post MI/R, the infarct size, IL-6, CRP, BNP, and matrix metalloproteinase-9 were reduced, and the ejection fraction was improved in pigs that underwent SICH.Conclusions::The SICH device safely and effectively reduced the infarct size and improved heart function in a pig model of MI/R. These beneficial effects indicate the clinical potential of SICH for treatment of myocardial reperfusion injury.
7.Longitudinal analysis of perioperative serum inflammatory factors in patients with HICH and correlation with prognosis
Jing LIU ; Jin WANG ; Wenyan LIU ; Xinwang CAI ; Xiang XU
Chinese Journal of Geriatric Heart Brain and Vessel Diseases 2024;26(8):902-905
Objective To longitudinally analyze the perioperative serum levels of inflammatory fac-tors in patients with hypertensive intracerebral hemorrhage(HICH),and to explore their correla-tion with prognosis.Methods A total of 173 HICH patients admitted to our hospital from Febru-ary 2021 to January 2023 were consecutively enrolled.Their serum levels of inflammatory factors were measured before operation,and in 6,12,24,48 and 72 h after operation.All of them were fol-lowed up for 6 months,and according to their prognosis,they were divided into good prognosis group(116 patients)and poor prognosis group(57 patients).Multivariate logistic regression anal-ysis was applied to analyze the correlation of the perioperative serum inflammatory factors with HICH prognosis.Results In these HICH patients,IL-6 and IL-1β were increased continuously within 72 h after operation,and the TNF-α level reached its peak at 48 h after operation.The poor prognosis group had significantly longer time from bleeding to admission(6.32±1.50 h vs 5.14±2.00 h),larger hematoma[35.50(24.50,46.00)ml vs 30.00(21.00,41.50)ml],and higher ratio of hematoma breaking into ventricles(28.07%vs 2.59%),and lower GCS score at admission(10.07±1.32 vs 11.00±0.85)when compared with the good prognosis group(P<0.05,P<0.01).Multivariate logistic regression analysis showed that the levels of IL-6,IL-1β and TNF-α at different postoperative time points were independent influencing factors for poor prognosis of HICH patients(P<0.05,P<0.01).Conclusion Serum levels of inflammatory factors IL-6,IL-1βand TNF-α are all elevated in HIGH patients during perioperative period,and their increments at different time points are correlated with the increased risk of adverse prognosis in the patients within 6 months after operation.
8.Extraperitoneal robot-assisted laparoscopic modified Y-V plasty for the treatment of refractory bladder neck contracture
Jin-Dong LI ; Chong ZHANG ; Cai LÜ ; Zhen-Xiang LIU ; Zhi-Ming BAI ; Xue-Jun SHANG
National Journal of Andrology 2024;30(9):798-802
Objective:To investigate the clinical effect of extraperitoneal robot-assisted laparoscopic modified Y-V plasty(LMYVP)in the treatment of refractory bladder neck contracture(BNC).Methods:We retrospectively analyzed the clinical data on 10 cases of refractory BNC after transurethral resection of the prostate between September 2020 and January 2023,all with a history of recurrent urethral dilatation and at least two failures in transurethral surgical treatment of scarring.After definite diagnosis and re-moval of some of the scar tissues to flatten the elevated bladder neck under the cystoscope,we performed robot-assisted LMYVP using the da Vinci Si robotic system and a four-port extraperitoneal approach.The surgical procedure involved an inverted T-shaped incision in the bladder neck and urethral stricture ring,an inverted V-shaped excision of the scar area at the 3-9 o'clock position on the ventral side of the prostatic urethra,continuous full-layer suturing of the bladder neck and inverted V-shaped urethra with 3-0 barbed thread,and indwelling of an F20 silicone catheter for 2 weeks.At 3 months after surgery,we performed cystoscopic examination,measured the maximum urinary flow rate(Qmax),and obtained the IPSS and quality of life(QOL)scores of the patients.Results:Operations were successfully completed in all the cases.At 3 months after surgery,the patients showed significantly increased Qmax([3.65±1.27]vs[20.3±1.77]ml/s,P<0.05),IPSS(5.9±2.02 vs 30±1.15,P<0.05)and QOL score(1.3±0.95 vs 5.2±0.79,P<0.05)compared with the baseline.Cystoscopy revealed a wide and flat bladder neck with good survival and hemody-namics of the bladder flap.All the patients met the criteria for clinical cure at a median follow-up of 13.2 months.Conclusion:Extraper-itoneal robot-assisted LMYVP provides a new strategy for urinary tract reconstruction in the management of refractory BNC,with the ad-vantages of minimal invasiveness,high efficiency and high success rate.
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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