1.Surveillance results of respiratory syncytial virus outbreaks in kindergarten and school in Shenzhen, 2017-2023
WANG Xin, FANG Shisong, WU Weihua, LIU Hui, SUN Ying, ZOU Xuan, TANG Xiujuan
Chinese Journal of School Health 2025;46(3):435-437
Objective:
To analyze respiratory syncytial virus(RSV) outbreaks surveillance results and the epidemiological characteristics in kindergarten and school in Shenzhen during 2017-2023 , so as to provide a scientific reference for control and prevention of RSV.
Methods:
Epidemiological data and surveillance results of RSV outbreaks in kindergarten and school from 2017 to 2023 were collected for descriptive analyses.
Results:
A total of 31 RSV outbreaks were identified in kindergarten and school in 2017-2023 in Shenzhen, 346 cases were reported, the average incidence rate was 22.02%. The most annual RSV outbreaks were reported in 2020 with 14 outbreaks, followed by 8 outbreaks in 2023. A total of 64.52% of RSV outbreaks were identified in kindergarten with rest occurring in primary school or middle school. The greatest monthly count of outbreak was 18 (58.06%) in September, followed by 3 outbreaks (9.68%) in March and October. A total of 244 swab samples were collected, 169 samples were positive for respiratory viruses, the positive rate was 69.26%, 121 samples were positive for RSV,from 31 respiratory syncytical virus outbreaks 57 and samples were positive for other respiratory viruses(9 samples were positive for two respiratory viruses). A toral of 14(45.16%) outbreaks are caused by RSV alone, 17 outbreaks (54.84%) were caused by RSV and other respiratory viruses.
Conclusions
Most RSV outbreaks in kindergarten and school are reported after 2020 in Shenzhen, most RSV outbreaks occur in kindergarten, peak seasons of RSV outbreaks are autumn and spring.
2.Application of task-driven approach combined with "7E" learning cycle in nurse refresher training on endoscopic retrograde cholangiopancreatography
Li LIU ; Xiujuan LIU ; Qun LUO ; Xia OU ; Lei LIU ; Li WANG
Chinese Journal of Medical Education Research 2024;23(4):512-516
Objective:To explore the application of the task-driven method combined with the "7E" learning cycle mode in nurse refresher training on endoscopic retrograde cholangiopancreatography (ERCP).Methods:We assigned 54 nurses who received refresher training on ERCP in the Department of Hepatobiliary Surgery of The First Affiliated Hospital of Army Medical University from January 2019 to December 2022 into control group (28 nurses from January 2019 to December 2020) to shadow and practice ERCP in a traditional way or experimental group (26 nurses from January 2021 to December 2022) to be taught using the task-driven method combined with the "7E" learning cycle method. At the end of training, the two groups undertook a theoretical and practical examination and a questionnaire survey. SPSS 25.0 was used to perform the t test, Wilcoxon test, chi-square test, and Fisher's exact test. Results:After training, compared with the control group, the experimental group had significantly higher scores of theory [87.50 (85, 90) vs. 90.51 (89, 92), P<0.05], and practice [84.11 (82.75, 85) vs. 90.52 (89, 92), P<0.05]. The proportions of trainees rating teaching methods excellent in the experimental group and control group were 76.92% ( n=20) and 42.86% ( n=12), respectively, and the proportions of teachers rating teaching effects excellent in the experimental group and control group were 84.62% ( n=22) and 42.86% ( n=12), respectively, both showing significant between-group differences (both P<0.05). Conclusions:The combination of the task-driven method and the "7E" learning cycle mode can mobilize learning initiative and enthusiasm, improve collaboration ability, promote learning interest and comprehensive practical ability for ERCP in nurses, which is suitable for ERCP training and teaching.
3.Effect of Angelica polysaccharides on Th17/T-regulatory cell balance and expression of related inflammatory factor proteins in bone marrow of mice with aplastic anemia
Xiubao CHEN ; Fei XU ; Xi YIN ; Weida CHEN ; Xing CUI ; Xiujuan LIU ; Zetao CHEN
Chinese Journal of Comparative Medicine 2024;34(8):1-9
Objective To investigate the effect of Angelica polysaccharides on the balance of Th17/T-regulatory(Treg)cells and the expression of related inflammatory factor proteins in the bone marrow of mice with aplastic anemia.Methods 50 male BALB/c mice were randomly divided into a normal group,model group,cyclosporine A(CsA)group,and angelica polysaccharide low-(APS-L)and high-dose(APS-H)groups.A mouse model of aplastic anemia was prepared by combining irradiation with allogeneic lymphocyte infusion.After modeling,the mice were orally administered with corresponding drugs for 28 days.The general condition,weight changes,and spleen index of the mice were observed.Blood samples were taken to test for changes in basic hematological parameters of peripheral blood,and hematoxylin and eosin staining was used to evaluate the pathological changes in mouse bone marrow tissue.An ELISA method was applied to detect bone marrow TGF-β1.The expression levels of proteins such as IL-10,IL-17A,and IL-6 were analyzed,and flow cytometry was used in detecting the bone marrow Th17/Treg cell ratio.Results Compared with the normal group,the model group mice showed clumsiness during activity;lethargy;pale eyelids,lips,and ears;and reduced food and water intake.Both body weight and spleen index were significantly decreased.Peripheral red blood cell,white blood cell,and platelet counts and hemoglobin concentration were significantly reduced.A disordered bone marrow tissue structure and significantly reduced proliferation of hematopoietic tissue were seen.The expression of IL-17A and IL-6 proteins was significantly upregulated,and the expression of TGF-β1 and IL-10 protein was significantly downregulated.The proportion of Th17 cells in bone marrow significantly increased,the proportion of Treg cells significantly decreased,and the ratio of Th17/Treg cells significantly increased(P<0.01).Compared with the model group,the general condition of the APS-L and APS-H groups improved,showing an increase in food and water intake;a significant increase in body weight and spleen index;a significant increase in peripheral red blood cells,white blood cells,platelets,and hemoglobin concentration(P<0.05);an improvement in bone marrow tissue structure;and an increase in hematopoietic tissue proliferation(P<0.05).The expression of IL-17A and IL-6 proteins was significantly downregulated.The expression of TGF-β1 and IL-10 protein was significantly upregulated(P<0.05 or P<0.01).The proportion of Th17 cells in bone marrow significantly decreased,the proportion of Treg cells significantly increased,and the ratio of Th17/Treg cells significantly decreased(P<0.01).Conclusions Angelica polysaccharides can improve bone marrow hematopoietic function in aplastic anemia mice,and its mechanism of action may include the regulation of Th17/Treg cell balance.
4.Effect of Xuebijing injection on acute gastrointestinal injury in patients with sepsis: a retrospective cohort study
Zhigang ZUO ; Liu PEI ; Yanmin ZHANG ; Tianzhi LIU ; Xiujuan LIU ; Zhenjie HU
Chinese Critical Care Medicine 2024;36(9):943-949
Objective:To observe the effect of Xuebijing injection on sepsis combined with acute gastrointestinal injury (AGI), and analyze the risk factors of sepsis combined with AGI.Methods:A retrospective cohort study was conducted. Patients with non-gastrointestinal origin admitted to the department of intensive care medicine of the First Hospital of Qinhuangdao from May 1, 2021 to October 30, 2023 were enrolled. The baseline data, source of sepsis infection, vital signs, acute physiology and chronic health evaluationⅡ(APACHEⅡ), sequential organ failure assessment (SOFA), laboratory tests, comorbidities, interventions during treatment, and the 28-day prognosis were collected. The patients were divided into Xuebijing group and non-Xuebijing group according to whether Xuebijing injection was used or not. According to whether AGI was merged or not, patients were divided into merged AGI group and non-merged AGI group. The main observational indexes were the difference in the incidence of AGI between the Xuebijing group and non-Xuebijing group and the difference in the magnitude of the decline in procalcitonin (PCT), C-reactive protein (CRP), and white blood cell count (WBC) at 7 days after admission, and the difference in the 28-day morbidity and mortality. Risk factors for AGI in septic patients were explored by univariate analysis, and statistically significant indicators were screened and included in binary Logistic regression analysis to determine independent risk factors.Results:A total of 129 patients with sepsis of non-gastrointestinal origin were enrolled, including 57 patients in the Xuebijing group and 72 patients in the non-Xuebijing group. Among 129 patients, 80 patients in the merged AGI group and 49 patients in the non-merged AGI group. There were no statistically significant differences between Xuebijing group and non-Xuebijing group in gender, age, body mass index (BMI), underlying disease, source of infection, vital sign, APACHEⅡscore, SOFA score, and clinical intervention, and there were no statistically significant differences in laboratory tests except for aspartate aminotransferase (AST) and blood urea nitrogen (BUN). The incidence of AGI was significantly lower in the Xuebijing group than that in the non-Xuebijing group [50.87% (29/57) vs. 70.83% (51/72), P < 0.05], and the 28-day mortality was slightly lower than that in the non-Xuebijing group [24.56% (14/57) vs. 30.56% (22/72), P > 0.05]. In the Xuebijing group, the decreases in CRP, PCT and WBC at 7 days after admission were greater than those in the non-Xuebijing group, with statistically significant differences in the decreases of CRP and PCT [CRP (mg/L): 47.12±67.34 vs. 7.76±111.03, PCT (μg/L): 14.08 (-1.22, 50.40) vs. 2.94 (-1.27, 14.80), all P < 0.05]. Univariate analysis showed that the use of acid suppressants, the use of analgesic sedation, the non-use of Xuebijing injections, pulmonary infections, and urinary tract infections were the risk factors for the development of AGI in patients with sepsis. Binary Logistic regression analysis further showed that the use of acid suppressants [odds ratio ( OR) = 2.450, 95% confidence interval (95% CI) was 1.021-5.883, P = 0.045], use of analgesic sedatives ( OR = 2.521, 95% CI was 1.074-5.918, P = 0.034), and urinary tract infection ( OR = 4.011, 95% CI was 1.085-14.831, P = 0.037) were independent risk factors for sepsis combined with AGI, in which the use of Xuebijing injection was a protective factor ( OR = 0.315, 95% CI was 0.137-0.726, P = 0.007). Conclusions:Xuebijing injection reduced the incidence of AGI in patients with non-gastrointestinal sepsis. PCT and CRP decreased more markedly than in patients who did not use Xuebijing injection. The use of acid-suppressing agents, analgesic and sedative agents, and urinary tract infections were independent risk factors for sepsis in combination with AGI, while the use of Xuebijing injection is a protective factor.
5.Clinical characteristics of patients with chronic obstructive pulmonary disease and positive specific IgE
Qinglin CHEN ; Xiujuan YAO ; Xiaofang LIU ; Ran LI ; Yuhong WANG ; Xichun ZHANG
Chinese Journal of Health Management 2024;18(5):339-346
Objective:To investigate the clinical features of patients with chronic obstructive pulmonary disease (COPD) and serum-positive specific IgE (SIgE).Methods:This study was a retrospective cohort study. A total of 105 stable COPD patients with allergic features and completed serum SIgE testing were included, and all of them were from Capital Medical University, Beijing Tong Ren Hospital from September 2022 to October 2023. Those with at least one positive result of SIgE testing were classified as positive SIgE COPD group, and those with negative SIgE were classified as negative SIgE COPD group. There were 32 cases (30.5%) in the positive SIgE COPD group and 73 cases (69.5%) in the negative SIgE COPD group. Differences in laboratory tests, pulmonary function, chronic obstructive pulmonary symptom scores, incidence of severe acute exacerbation events in the past year, and drug therapy were compared between the two groups. The risk factors for positive SIgE COPD were analyzed, and the best predictive value for the diagnosis of positive SIgE COPD was analyzed using the area under the curve (AUC) of receiver operating characteristic (ROC).Results:Compared with the negative SIgE COPD group, the percentage of positive SIgE COPD group with rhinitis, sinusitis, sinusitis with nasal polyps, eczema, and a history of drug or food allergy were higher (all P<0.05) and the percentage of those who had quit smoking were higher ( P<0.05); the percentage of IgE above normal thresholds, the level of IgE, the percentage of peripheral blood eosinophil (EOS%), the count of EOS, and fractional exhaled nitric oxide (FeNO) were higher (all P<0.05), and the percentage of those who had severe and above severe Global Strategy for the Diagnosis, Management, and Prevention of COPD (GOLD) pulmonary function classification were higher, while the percentage of forced expiratory volume in one second (FEV 1% predicted), 25% maximal expiratory flow (MEF 25%) and MEF 75/25% were lower, and FEV 1/FVC was higher (all P<0.05). The positive SIgE COPD group had higher modified British medical research council (mMRC) scores and COPD assessment test (CAT) scores, and a higher incidence of severe acute exacerbation events over the past year (all P<0.05), and the use of short-acting β 2 receptor agonists (SABA) or short-acting muscarinic antagonist (SAMA), inhaled corticosteroid (ICS), theophylline and oral hormone therapy were more frequent (all P<0.05). EOS% ( OR=1.252, 95% CI: 1.039-1.508) was a risk factor for SIgE positivity in COPD ( P<0.05), and having quit smoking ( OR=0.385, 95% CI: 0.197-0.751) was a protective factor ( P<0.05). The AUC value of the ROC curve of EOS%>2.5% for the diagnosis of SIgE positivity was 0.647 (95% CI: 0.543-0.752), with a sensitivity and specificity of 52.8% and 73.1%, respectively. Conclusions:Positive SIgE COPD has sever clinical symptoms, high risk of acute exacerbation and deficiencies in treatment. The elevate of EOS% is a risk factor for the development of positive SIgE in COPD patients; positive SIgE COPD meets the diagnostic criteria for allergic COPD phenotype, and EOS% over 2.5% is suggestive of the clinical detection of allergic COPD phenotype.
6.Effect of macrophage-derived exosomes on the morphological transformation of Candida albicans
Shuo LI ; Yuanyuan SUN ; Ruiying HAO ; Yanyan XU ; Zhao LIU ; Tingting JING ; Xiaojing LI ; Xiujuan ZHANG
Chinese Journal of Dermatology 2024;57(6):539-546
Objective:To investigate the effect of macrophage-derived exosomes on the morphological transformation of Candida albicans (CA), and to explore the underlying mechanisms.Methods:In vitro cultured human acute monocytic leukemia cell line THP-1 was induced and differentiated into M0 macrophages using the phorbol ester PMA. CA was activated and prepared as the fungal suspension. M0 macrophages were infected with the CA suspension, and the process of cell phagocytosis was observed under a high-content imaging analysis system. M0 macrophage-derived exosomes (exosome group) and CA-infected M0 macrophage-derived exosomes (CA exosome group) were extracted by differential centrifugation; transmission electron microscopy, nanoparticle tracking analysis, and Western blot analysis were performed to identify and compare exosomes in the two groups. The exosomes from the two groups were separately co-cultured with CA (exosome-treated group and CA exosome-treated group), and independently cultured CA served as the blank control group; the morphological changes of CA were observed under an inverted microscope, the intracellular cyclic adenosine monophosphate (cAMP) contents were detected by the enzyme-linked immunosorbent assay (ELISA), and the expression levels of cAMP-related genes, RAS1 and CDC35 (also known as Cyr1), were detected by real-time quantitative PCR (RT-qPCR) . Results:Western blot analysis showed that exosomes from the exosome group and CA exosome group both expressed the tumor susceptibility gene 101 protein (TSG101, an exosome marker), and did not express calnexin (a negative marker) ; transmission electron microscopy and nanoparticle tracking analysis showed no significant differences in the morphology or size of the exosomes between the two groups. Compared with the blank control group, the exosome-treated group and CA exosome-treated group both showed obvious inhibition of the yeast-to-mycelial phase transition of CA, with a noticeable reduction in the length of the hyphae under the inverted microscope. ELISA revealed that the intracellular cAMP content in CA significantly decreased in the exosome-treated group and CA exosome-treated group (16.70 ± 0.84 pmol/ml, 16.82 ± 0.87 pmol/ml, respectively) compared with the blank control group (21.82 ± 1.08 pmol/ml; t = 6.45, 6.23, respectively, both P = 0.003). RT-qPCR revealed that the expression of the cAMP-related genes, RAS1 and CDC35, was down-regulated in the exosome-treated group and CA exosome-treated group compared with the blank control group (all P < 0.01), and the RAS1 mRNA expression was significantly lower in the CA exosome-treated group than in the exosome-treated group ( t = 7.43, P = 0.002) . Conclusion:Both M0 macrophage-derived exosomes and CA-infected M0 macrophage-derived exosomes could effectively inhibit the mycelial growth of CA, and the latter one exhibited a stronger inhibitory effect, possibly by down-regulating cAMP in the cAMP/protein kinase A pathway.
7.Correlation between functional striatal abnormalities scores and symptoms and cognitive function in patients with schizophrenia
Zheng LI ; Qing LIU ; Xiaoge GUO ; Xiujuan WANG ; Xi SU ; Yongfeng YANG ; Wenqiang LI ; Luxian LYU
Journal of Xinxiang Medical College 2024;41(7):640-644
Objective To explore the correlation between functional striatal abnormalities(FSA)scores and symptoms and cognitive function in patients with schizophrenia.Methods A total of 92 patients with schizophrenia admitted to the Second Affiliated Hospital of Xinxiang Medical University from July 2021 to February 2022 were selected as the research subjects,15 patients were excluded due to excessive interference with head movement during image data analysis,and 77 patients were finally included in the statistical analysis.The cognitive function of the patients before treatment and after 8 weeks of treatment was evaluated through a set of cognitive function tests.The severity of symptoms before treatment and after 8 weeks of treatment was evaluated according to the positive and negative symptom scale(PANSS).The patients were divided into the ineffective group(PANSS<50%,n=33)and the effective group(PANSS ≥ 50%,n=44)according to the PANSS reduction rate.Before treatment and 8 weeks after treatment,the resting-state functional magnetic resonance imaging scans were performed,and FSA scores were calculated.Results There was no significant difference in FSA scores of patients between the effective group and the ineffective group before treatment(P>0.05).After 8 weeks of treatment,the FSA scores of patients in the two groups were significantly higher than those before treatment(P<0.05).After 8 weeks of treatment,there was no significant difference in FSA scores of patients between the effective group and the ineffective group(P>0.05).Before treatment and after 8 weeks of treatment,there was no significant correlation between the FSA scores and the total PANSS scores,positive factor scores,negative factor scores and pathological factor scores in the two groups(P>0.05).There was no significant corre-lation between the pre-treatment FSA scores and the differences in positive factor scores,negative factor scores and pathological factor scores before and after treatment in both groups(P>0.05).In the effective group,the FSA score was significantly nega-tively correlated with the spatial span score(P<0.05)and significantly positively correlated with the category fluency score(P<0.05)before treatment;however,there was no significant correlation between the pre-treatment FSA score and the scores of trail making,symbol coding,word learning,maze solving,visuospatial memory,2-digit continuous performance,3-digit continuous performance and 4-digit continuous performance(P>0.05).In the ineffective group,there was a significant negative correlation between the pre-treatment FSA score and the spatial span and 4-digit continuous performance scores(P<0.05),while there was no significant correlation between the pre-treatment FSA score and the scores of trail making,symbol coding,word learning,maze solving,visuospatial memory,category fluency,2-digit continuous performance and 3-digit continuous performance(P>0.05).There was no significant correlation between the FSA score and cognitive function scores after treat-ment in the effective group(P>0.05).There was a significant positive correlation between the FSA score and the trail making score after treatment in the ineffective group(P<0.05),but there was no significant correlation between the FSA score and the scores of symbol coding,word learning,spatial span,maze solving,visuospatial memory,category fluency,2-digit continuous performance,3-digit continuous performance and 4-digit continuous performance(P>0.05).Conclusion FSA scores in patients with schizophrenia increase significantly after treatment.FSA scores may not be related to the severity of symptoms or treatment response,but are correlated with the cognitive function of information processing speed.
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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