This study aims to investigate the molecular mechanism by which naringin alleviates cerebral ischemia/reperfusion(CI/R) injury through DRP1/LRRK2/MCU signaling axis. A total of 60 SD rats were randomly divided into the sham group, the model group, the sodium Danshensu group, and low-, medium-, and high-dose(50, 100, and 200 mg·kg~(-1)) naringin groups, with 10 rats in each group. Except for the sham group, a transient middle cerebral artery occlusion/reperfusion(tMCAO/R) model was established in SD rats using the suture method. Longa 5-point scale was used to assess neurological deficits. 2,3,5-Triphenyl tetrazolium chloride(TTC) staining was used to detect the volume percentage of cerebral infarction in rats. Hematoxylin-eosin(HE) staining and Nissl staining were employed to assess neuronal structural alterations and the number of Nissl bodies in cortex, respectively. Western blot was used to determine the protein expression levels of B-cell lymphoma-2 gene(Bcl-2), Bcl-2-associated X protein(Bax), cleaved cysteine-aspartate protease-3(cleaved caspase-3), mitochondrial calcium uniporter(MCU), microtubule-associated protein 1 light chain 3(LC3), and P62. Mitochondrial structure and autophagy in cortical neurons were observed by transmission electron microscopy. Immunofluorescence assay was used to quantify the fluorescence intensities of MCU and mitochondrial calcium ion, as well as the co-localization of dynamin-related protein 1(DRP1) with leucine-rich repeat kinase 2(LRRK2) and translocase of outer mitochondrial membrane 20(TOMM20) with LC3 in cortical mitochondria. The results showed that compared with the model group, naringin significantly decreased the volume percentage of cerebral infarction and neurological deficit score in tMCAO/R rats, alleviated the structural damage and Nissl body loss of cortical neurons in tMCAO/R rats, inhibited autophagosomes in cortical neurons, and increased the average diameter of cortical mitochondria. The Western blot results showed that compared to the sham group, the model group exhibited increased levels of cleaved caspase-3, Bax, MCU, and the LC3Ⅱ/LC3Ⅰ ratio in the cortex and reduced protein levels of Bcl-2 and P62. However, naringin down-regulated the protein expression of cleaved caspase-3, Bax, MCU and the ratio of LC3Ⅱ/LC3Ⅰ ratio and up-regulated the expression of Bcl-2 and P62 proteins in cortical area. In addition, immunofluorescence analysis showed that compared with the model group, naringin and positive drug treatments significantly decreased the fluorescence intensities of MCU and mitochondrial calcium ion. Meanwhile, the co-localization of DRP1 with LRRK2 and TOMM20 with LC3 in cortical mitochondria was also decreased significantly after the intervention. These findings suggest that naringin can alleviate cortical neuronal damage in tMCAO/R rats by inhibiting DRP1/LRRK2/MCU-mediated mitochondrial fragmentation and the resultant excessive mitophagy.
Animals ; Rats, Sprague-Dawley ; Reperfusion Injury/genetics* ; Flavanones/administration & dosage* ; Rats ; Dynamins/genetics* ; Male ; Brain Ischemia/genetics* ; Protein Serine-Threonine Kinases/genetics* ; Signal Transduction/drug effects* ; Humans ; Drugs, Chinese Herbal/administration & dosage*

OBJECTIVE: To examine the mechanism of action of tanshinone II A (Tan II A) in promoting chemosensitization of osteosarcoma cells to cisplatin (DDP). METHODS: The effects of different concentrations of Tan II A (0-80 µ mol/L) and DDP (0-2 µ mol/L) on the proliferation of osteosarcoma cell lines (U2R, U2OS, 143B, and HOS) at different times were examined using the cell counting kit-8 and colony formation assays. Migration and invasion of U2R and U2OS cells were detected after 24 h treatment with 30 µ mol/L Tan II A, 0.5 µ mol/L DDP alone, and a combination of 10 µ mol/L Tan II A and 0.25 µ mol/L DDP using the transwell assay. After 48 h of treatment of U2R and U2OS cells with predetermined concentrations of each group of drugs, the cell cycle was analyzed using a cell cycle detection kit and flow cytometry. After 48 h treatment, apoptosis of U2R and U2OS cells was detected using annexin V-FITC apoptosis detection kit and flow cytometry. U2R cells were inoculated into the unilateral axilla of nude mice and then the mice were randomly divided into 4 groups of 6 nude mice each. The 4 groups were treated with equal volume of Tan II A (15 mg/kg), DDP (3 mg/kg), Tan II A (7.5 mg/kg) + DDP (1.5 mg/kg), and normal saline, respectively. The body weight of the nude mice was weighed, and the tumor volume and weight were measured. Cell-related gene and signaling pathway expression were detected by RNA sequencing and Kyoto Encyclopedia of Genes and Genomes pathway analysis. p38 MAPK signaling pathway proteins and apoptotic protein expressions were detected by Western blot. RESULTS: In vitro studies have shown that Tan II A, DDP and the combination of Tan II A and DDP inhibit the proliferation, migration and invasion of osteosarcoma cells. The inhibitory effect was more pronounced in the Tan II A and DDP combined treatment group (P<0.05 or P<0.01). Osteosarcoma cells underwent significantly cell-cycle arrest and cell apoptosis by Tan II A-DDP combination treatment (P<0.05 or P<0.01). In vivo studies demonstrated that the Tan II A-DD combination treatment group significantly inhibited tumor growth compared to the Tan II A and DDP single drug group (P<0.01). Additionally, we found that the combination of Tan II A and DDP treatment enhanced the p38 MAPK signaling pathway. Western blot assays showed higher p-p38, cleaved caspase-3, and Bax and lower caspase-3, and Bcl-2 expressions with the combination of Tan II A and DDP treatment compared to the single drug treatment (P<0.01). CONCLUSION Tan II A synergizes with DDP by activating the p38/MAPK pathway to upregulate cleaved caspase-3 and Bax pro-apoptotic gene expressions, and downregulate caspase-3 and Bcl-2 inhibitory apoptotic gene expressions, thereby enhancing the chemosensitivity of osteosarcoma cells to DDP.
Abietanes/therapeutic use* ; Osteosarcoma/enzymology* ; Cisplatin/therapeutic use* ; Humans ; Cell Line, Tumor ; Animals ; Apoptosis/drug effects* ; Mice, Nude ; Cell Proliferation/drug effects* ; Cell Movement/drug effects* ; p38 Mitogen-Activated Protein Kinases/metabolism* ; MAP Kinase Signaling System/drug effects* ; Bone Neoplasms/enzymology* ; Cell Cycle/drug effects* ; Xenograft Model Antitumor Assays ; Mice ; Drug Resistance, Neoplasm/drug effects* ; Neoplasm Invasiveness ; Mice, Inbred BALB C

ObjectiveProtein arginine methyltransferases (PRMTs) play pivotal roles in numerous cellular biological processes. However, the precise regulatory effects of PRMTs on the fate determination of mesenchymal stromal/stem cells (MSCs) remain elusive. Our previous studies have shed light on the regulatory role and molecular mechanism of PRMT5 in MSC osteogenic differentiation. This study aims to clarify the role and corresponding regulatory mechanism of PRMT7 during the adipogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs). Methods(1) Human bone marrow-derived mesenchymal stem cells (hBMSCs) were cultured in a medium that induces adipogenesis. We used qRT-PCR and Western blot to monitor changes in PRMT7 expression during adipogenic differentiation. (2) We created a cell line with PRMT7 knocked down and assessed changes in PRMT7 expression and adipogenic capacity using Oil Red O staining, qRT-PCR and Western blot. (3) We implanted hBMSCs cell lines mixed with a collagen membrane subcutaneously into nude mice and performed Oil Red O staining to observe ectopic lipogenesis in vivo. (4) A cell line overexpressing PRMT7 was generated, and we examined changes in PRMT7 expression using qRT-PCR and Western blot. We also performed Oil Red O staining and quantitative analysis after inducing the cells in lipogenic medium. Additionally, we assessed changes in PPARγ expression. (5) We investigated changes in insulin-like growth factor 1 (IGF-1) expression in both PRMT7 knockdown and overexpressing cell lines using qRT-PCR and Western blot, to understand PRMT7’s regulatory effect on IGF-1 expression. siIGF-1 was transfected into the PRMT7 knockdown cell line to inhibit IGF-1 expression, and knockdown efficiency was confirmed. Then, we induced cells from the control and knockdown groups transfected with siIGF-1 in lipogenic medium and performed Oil Red O staining and quantitative analysis. Finally, we assessed PPARγ expression to explore IGF-1’s involvement in PRMT7’s regulation of adipogenic differentiation in hBMSCs. Results(1) During the adipogenesis process of hBMSCs, the expression level of PRMT7 was significantly reduced (P<0.01). (2) The adipogenic differentiation ability of PRMT7 knockdown group was significantly stronger than that of control group (P<0.001). (3) The ectopic adipogenic differentiation ability of PRMT7 knockdown group was significantly stronger than that of control group. (4) The adipogenic differentiation ability of the PRMT7 overexpression group was significantly weaker than that of the control group (P<0.01). (5) The expression level of IGF-1 increased after PRMT7 knockdown (P<0.000 1). The expression level of IGF-1 decreased after PRMT7 overexpression (P<0.000 1), indicating that PRMT7 regulates the expression of IGF-1. After siIGF-1 transfection, the expression level of IGF-1 in all cell lines decreased significantly (P<0.001). The ability of adipogenic differentiation of knockdown group transfected with siIGF-1 was significantly reduced (P<0.01), indicating that IGF-1 affects the regulation of PRMT7 on adipogenic differentiation of hBMSCs. ConclusionIn this investigation, our findings elucidate the inhibitory role of PRMT7 in the adipogenic differentiation of hBMSCs, as demonstrated through both in vitro cell-level experiments and in vivo subcutaneous transplantation experiments conducted in nude mice. Mechanistic exploration revealed that PRMT7’s regulatory effect on the adipogenic differentiation of hBMSCs operates via modulation of IGF-1 signaling pathway. These collective findings underscore PRMT7 as a potential therapeutic target for fatty metabolic disorders, thereby offering a novel avenue for leveraging PRMT7 and hBMSCs in the therapeutic landscape of relevant diseases.

Objective To explore the effect of scutellarin on lipopolysaccharide(LPS)induced neuroinflammation in BV-2 microglia cells.Methods BV-2 microglia were cultured and randomly divided into 6 groups:control group(Ctrl),cyclic GMP-AMP synthetase(cGAS)inhibitor RU320521 group(RU.521 group),LPS group,LPS+RU.521 group,LPS+scutellarin pretreatment group(LPS+S)and LPS+S+RU.521 group.The expressions of cGAS,stimulator of interferon gene(STING),nuclear factor kappa B(NF-κB),phosphorylated NF-κB(p-NF-κB),neuroinflammatory factors PYD domains-containing protein 3(NLRP3)and tumor necrosis factor α(TNF-α)in BV-2 microglia were detected by Western blotting and immunofluorescent double staining(n= 3).Results Western blotting and immunofluorescent double staining showed that compared with the control group,the expression of cGAS,STING,p-NF-κB,NLRP3 and TNF-α in BV-2 microglia increased significantly after LPS induction(P<0.05),while the expression of cGAS,STING,p-NF-κB,NLRP3 and TNF-α in LPS+S group were significantly lower than those in LPS group(P<0.05).Treatment with cGAS pathway inhibitor RU.521 showed similar effects as the pre-treatment group with scutellarin.In addition,the change of NF-κB in each group was not statistically significant(P>0.05).Conclusion Scutellarin inhibits the neuroinflammation mediated by BV-2 microglia cells,which may be related to cGAS-STING signaling pathway.

Objective To observe the effect of Anchang Formula(mainly composed of Agrimoniae Herba,Sanguisorbae Radix,Poria,Pulsatillae Radix,Atractylodis Macrocephalae Rhizoma,and fried Paeoniae Radix Alba)combined with Aluminum Phosphate Gel on inflammatory factors,immune function and intestinal flora in patients with radiation enteritis caused by radiotherapy for cervical cancer.Methods Seventy-eight patients with radiation enteritis caused by radiotherapy for cervical cancer were randomly divided into combined group(41 cases)and reference group(37 cases).The reference group was treated with Aluminum Phosphate Gel,and the combined group was treated with Anchang Formula combined with Aluminum Phosphate Gel.The course of treatment for the two groups lasted for 15 days.The changes of traditional Chinese medicine(TCM)syndrome scores,serum interleukin 2(IL-2),procalcitonin(PCT),T lymphocyte subsets CD4+,CD8+,CD4+/CD8+ levels and intestinal flora in the two groups were observed before and after treatment.After treatment,the clinical efficacy of the two groups was evaluated.Results(1)After 15 days of treatment,the total effective rate of the combined group was 90.24%(37/41),and that of the reference group was 70.27%(26/37).The intergroup comparison showed that the clinical efficacy of the combined group was significantly superior to that of the reference group(P＜0.05).(2)After treatment,the scores of TCM symptoms of mucopurulent bloody stool,diarrhea,tenesmus and abdominal pain in the two groups were lower than those before treatment(P＜0.05),and the decrease in the combined group was significantly superior to that in the reference group(P＜0.01).(3)After treatment,the levels of serum inflammatory factors of IL-2 and PCT in the two groups were lower than those before treatment(P＜0.05),and the decrease in the combined group was more obvious than that in the reference group(P＜0.01).(4)After treatment,the levels of immune function indicators of T lymphocyte subsets CD4+ and CD4+/CD8+ in the two groups were higher than those before treatment(P＜0.05),and the level of CD8+ was lower than that before treatment(P＜0.05).The increase of CD4+ and CD4+/CD8+ levels and the decrease of CD8+ levels in the combined group were more obvious than those in the reference group(P＜0.01).(5)After treatment,the levels of intestinal flora of Lactobacillus,Bifidobacterium and Escherichia coli in the two groups were higher than those before treatment(P＜0.05),and the increase in the combined group was more obvious that in the reference group(P＜0.01).Conclusion Anchang Formula combined with Aluminum Phosphate Gel exerts significant efficacy for the treatment of patients with radiation enteritis caused by radiotherapy for cervical cancer.The combined therapy can effectively relieve the clinical symptoms of patients,reduce the inflammatory reaction,improve the immune function,and balance the intestinal flora.

Objective To explore the effect of gastrodin(GAS)on the polarization of M2 microglia under oxygen and glucose deprivation(OGD)and the effect of p38 MAPK inhibition on the polarization status of microglia.Methods BV2 microglia was divided into the control group(Ctrl),p38 MAPK inhibitor SB203580 group(Ⅰ),OGD group(OGD),OGD+I group,gastrodin treatment group(G+OGD),and G+OGD+Ⅰ group.The expressions of p38 MAPK,phosphorylated p38 MAPK(p-p38 MAPK),M2 microglia marker arginase-1(Arg-1)and chitinase like protein 1/2(YM1/2)were detected by immunofluorescent staining and Western blotting.Results Immunofluorescent staining results showed that the pretreatment with gastrodin reduced the fluorescence expression of p-p38 MAPK in OGD induced BV2 microglia,enhanced the fluorescence expressions of Arg-1 and YM1/2.After pretreatment with SB203580,the fluorescence expressions of p-p38 MAPK further decreased,the fluorescence expressions of Arg-1 and YM1/2 further increased,both were significantly different from the G+OGD group(n=3,P＜0.05).The fluorescence expressions of p38 MAPK in each group was not statistically significant(n=3,P＞0.05).Western blotting results showed that the protein expressions of p-p38 MAPK,Arg-1 and YM1/2 in the OGD group enhanced,compared with that in the control group(n=3,P＜0.05).After the pretreatment with gastrodin,the protein expression of p-p38 MAPK was reduced significantly,the protein expressions of Arg-1 and YM1/2 was enhanced obviously,both were significantly different from the OGD group(n=3,P＜0.05).After pretreatment with SB203580,the protein expressions of p-p38 MAPK was further reduced,the protein expression of Arg-1 and YM1/2 were further enhanced,both were significantly different from the G+OGD group(n=3,P＜0.05).In addition,there was no significant change in p38 MAPK protein expression among groups(n=3,P＞0.05).Conclusion Gastrodin inhibits p38 MAPK signaling activation to promote BV2 microglial polarization towards the M2 phenotype,reducing inflammatory responses and exerting a protective effect.

Objective: To investigate the antimicrobial resistance of food-borne diarrheagenic Escherichia coli (DEC) and the prevalence of mcr genes that mediates mobile colistin resistance in parts of China, 2020. Methods: For 91 DEC isolates recovered from food sources collected from Fujian province, Hebei province, Inner Mongolia Autonomous Region and Shanghai city in 2020, Vitek2 Compact biochemical identification and antimicrobial susceptibility testing platform was used for the detection of antimicrobial susceptibility testing (AST) against to 18 kinds of antimicrobial compounds belonging to 9 categories, and multi-polymerase chain reaction (mPCR) was used to detect the mcr-1-mcr-9 genes, then a further AST, whole genome sequencing (WGS) and bioinformatics analysis were platformed for these DEC isolates which were PCR positive for mcr genes. Results: Seventy in 91 isolates showed different antimicrobial resistance levels to the drugs tested with a resistance rate of 76.92%. The isolates showed the highest antimicrobial resistance rates to ampicillin (69.23%, 63/91) and trimethoprim-sulfamethoxazole (59.34%, 54/91), respectively. The multiple drug-resistant rate was 47.25% (43/91). Two mcr-1 gene and ESBL (extended-spectrum beta-lactamase) positive EAEC (enteroaggregative Escherichia coli) strains were detected. One of them was identified as serotype of O11:H6, which showed a resistance profile to 25 tested drugs referring to 10 classes, and 38 drug resistance genes were predicted by genome analysis. The other one was O16:H48 serotype, which was resistant to 21 tested drugs belonging to 7 classes and carried a new variant of mcr-1 gene (mcr-1.35). Conclusion: An overall high-level antimicrobial resistance was found among foodborne DEC isolates recovered from parts of China in 2020, and so was the MDR (multi-drug resistance) condition. MDR strains carrying multiple resistance genes such as mcr-1 gene were detected, and a new variant of mcr-1 gene was also found. It is necessary to continue with a dynamic monitoring on DEC contamination and an ongoing research into antimicrobial resistance mechanisms.
Humans ; Colistin/pharmacology* ; Anti-Bacterial Agents/pharmacology* ; Escherichia coli Infections/epidemiology* ; Escherichia coli Proteins/genetics* ; Drug Resistance, Bacterial/genetics* ; China/epidemiology* ; Escherichia coli ; Plasmids/genetics* ; Microbial Sensitivity Tests

Objective: Compare and analyze the results of the domestic Lanyi AH600 glycated hemoglobin analyzer and other different detection systems to understand the comparability of the detection results of different detectors, and establish the best cut point of Lanyi AH600 determination of haemoglobin A1c (HbA1c) in the diagnosis of diabetes. Methods: Multi center cohort study was adopted. The clinical laboratory departments of 18 medical institutions independently collected test samples from their respective hospitals from March to April 2022, and independently completed comparative analysis of the evaluated instrument (Lanyi AH600) and the reference instrument HbA1c. The reference instruments include four different brands of glycosylated hemoglobin meters, including Arkray, Bio-Rad, DOSOH, and Huizhong. Scatter plot was used to calculate the correlation between the results of different detection systems, and the regression equation was calculated. The consistency analysis between the results of different detection systems was evaluated by Bland Altman method. Consistency judgment principles: (1) When the 95% limits of agreement (95% LoA) of the measurement difference was within 0.4% HbA1c and the measurement score was≥80 points, the comparison consistency was good; (2) When the measurement difference of 95% LoA exceeded 0.4% HbA1c, and the measurement score was≥80 points, the comparison consistency was relatively good; (3) The measurement score was less than 80 points, the comparison consistency was poor. The difference between the results of different detection systems was tested by paired sample T test or Wilcoxon paired sign rank sum test; The best cut-off point of diabetes was analyzed by receiver operating characteristic curve (ROC). Results: The correlation coefficient R² of results between Lanyi AH600 and the reference instrument in 16 hospitals is≥0.99; The Bland Altman consistency analysis showed that the difference of 95% LoA in Nanjing Maternity and Child Health Care Hospital in Jiangsu Province (reference instrument: Arkray HA8180) was -0.486%-0.325%, and the measurement score was 94.6 points (473/500); The difference of 95% LoA in the Tibetan Traditional Medical Hospital of TAR (reference instrument: Bio-Rad Variant II) was -0.727%-0.612%, and the measurement score was 89.8 points; The difference of 95% LoA in the People's Hospital of Chongqing Liang Jiang New Area (reference instrument: Huizhong MQ-2000PT) was -0.231%-0.461%, and the measurement score was 96.6 points; The difference of 95% LoA in the Taihe Hospital of traditional Chinese Medicine in Anhui Province (reference instrument: Huizhong MQ-2000PT) was -0.469%-0.479%, and the measurement score was 91.9 points. The other 14 hospitals, Lanyi AH600, were compared with 4 reference instrument brands, the difference of 95% LoA was less than 0.4% HbA1c, and the scores were all greater than 95 points. The results of paired sample T test or Wilcoxon paired sign rank sum test showed that there was no statistically significant difference between Lanyi AH600 and the reference instrument Arkray HA8180 (Z=1.665,P=0.096), with no statistical difference. The mean difference between the measured values of the two instruments was 0.004%. The comparison data of Lanyi AH600 and the reference instrument of all other institutions had significant differences (all P<0.001), however, it was necessary to consider whether it was within the clinical acceptable range in combination with the results of the Bland-Altman consistency analysis. The ROC curve of HbA1c detected by Lanyi AH600 in 985 patients with diabetes and 3 423 patients with non-diabetes was analyzed, the area under curve (AUC) was 0.877, the standard error was 0.007, and the 95% confidence interval 95%CI was (0.864, 0.891), which was statistically significant (P<0.001). The maximum value of Youden index was 0.634, and the corresponding HbA1c cut point was 6.235%. The sensitivity and specificity of diabetes diagnosis were 76.2% and 87.2%, respectively. Conclusion: Among the hospitals and instruments currently included in this study, among these four hospitals included Nanjing Maternity and Child Health Care Hospital in Jiangsu Province (reference instrument: Arkray HA8180), Tibetan Traditional Medical Hospital of TAR (reference instrument: Bio-Rad Variant Ⅱ), the People's Hospital of Chongqing Liang Jiang New Area (reference instrument: Huizhong MQ-2000PT), and the Taihe Hospital of traditional Chinese Medicine in Anhui Province (reference instrument: Huizhong MQ-2000PT), the comparison between Lanyi AH600 and the reference instruments showed relatively good consistency, while the other 14 hospitals involved four different brands of reference instruments: Arkray, Bio-Rad, DOSOH, and Huizhong, Lanyi AH600 had good consistency with its comparison. The best cut point of the domestic Lanyi AH600 for detecting HbA1c in the diagnosis of diabetes is 6.235%.
Pregnancy ; Child ; Humans ; Female ; Glycated Hemoglobin ; Cohort Studies ; Diabetes Mellitus/diagnosis* ; Sensitivity and Specificity ; ROC Curve

Objective: To analyze the spatial and temporal distribution characteristics of seasonal A(H3N2) influenza [influenza A(H3N2)] in China and to provide a reference for scientific prevention and control. Methods: The influenza A(H3N2) surveillance data in 2014-2019 was derived from China Influenza Surveillance Information System. A line chart described the epidemic trend analyzed and plotted. Spatial autocorrelation analysis was conducted using ArcGIS 10.7, and spatiotemporal scanning analysis was conducted using SaTScan 10.1. Results: A total of 2 603 209 influenza-like case sample specimens were detected from March 31, 2014, to March 31, 2019, and the influenza A(H3N2) positive rate was 5.96%(155 259/2 603 209). The positive rate of influenza A(H3N2) was statistically significant in the north and southern provinces in each surveillance year (all P<0.05). The high incidence seasons of influenza A (H3N2) were in winter in northern provinces and summer or winter in southern provinces. Influenza A (H3N2) clustered in 31 provinces in 2014-2015 and 2016-2017. High-high clusters were distributed in eight provinces, including Beijing, Tianjin, Hebei, Shandong, Shanxi, Henan, Shaanxi, and Ningxia Hui Autonomous Region in 2014-2015, and high-high clusters were distributed in five provinces including Shanxi, Shandong, Henan, Anhui, and Shanghai in 2016-2017. Spatiotemporal scanning analysis from 2014 to 2019 showed that Shandong and its surrounding twelve provinces clustered from November 2016 to February 2017 (RR=3.59, LLR=9 875.74, P<0.001). Conclusion: Influenza A (H3N2) has high incidence seasons with northern provinces in winter and southern provinces in summer or winter and obvious spatial and temporal clustering characteristics in China from 2014-2019.
Humans ; Influenza, Human/epidemiology* ; China/epidemiology* ; Influenza A Virus, H3N2 Subtype ; Seasons ; Cluster Analysis

Objective: To explore the effect and mechanism of small GTP-binding protein GDP dissociation stimulator (SmgGDS) on the development of obesity. Methods: (1) 8-week-old C57BL/6J mice were randomly assigned to normal diet and high fat diet group, with 6 mice in each group. They were fed regular feed and a high fat diet containing 60% fat for 4 months, respectively. The expression of SmgGDS in epididymal adipose tissue (eWAT), liver, and skeletal muscle were measured using Western-blot. (2) 6-week-old wild-type (WT) and SmgGDS knockdown (KD) mice were divided into four groups, each receiving high fat diet for 4 months (7 in each group) and 7 months (9 in each group). Glucose tolerance test (GTT) and insulin tolerance test (ITT) were conducted; The weight, adipose tissue, and liver weight of mice were recorded; HE staining examined adipose tissue structural changes; Western-blot determined extracellular signal-regulated kinase (ERK) 1/2 phosphorylation levels in eWAT; Real time fluorescence quantitative polymerase chain reaction (RT-qPCR) was used to detect mRNA levels of CCAAT/enhancer binding protein α (C/EBPα), C/EBPβ and peroxisome proliferator activated receptor γ (PPARγ) in eWAT. (3) Mouse embryonic fibroblasts (MEFs) extracted from WT and KD mice were induced for differentiation. Oil red O staining and Western-blot were used to detect lipid droplet and expression of SmgGDS and phospho-ERK; C/EBPα, C/EBPβ and PPARγ mRNA levels were measured using RT-qPCR. (4) 10-week-old C57BL/6J mice were randomly assigned into two groups, with 7 mice in each group. Mice were infected with SmgGDS overexpressing adeno-associated virus (AAV-SmgGDS) or empty vector intraperitoneally, then fed with high fat diet. After 4 weeks, performed GTT and ITT; Recorded the weight and adipose tissue weight of mice; HE staining was used to analyze structural changes of eWAT; Western-blot was used to detect the phosphorylation level of ERK in eWAT. Results: (1) The expression of SmgGDS was significantly upregulated in eWAT of high fat diet fed mice (normal diet group: 0.218±0.037, high fat diet group:0.439±0.072, t=2.74, P=0.034). (2) At 4 months of high fat diet intervention, the glucose tolerance (60 minutes after glucose injection, WT group: 528 mg/dl±21 mg/dl, KD group: 435 mg/dl±17 mg/dl, t=3.47, P=0.030; 90 minutes, WT group: 463 mg/dl±24 mg/dl, KD group: 366 mg/dl±18 mg/dl, t=3.23, P=0.047;120 minutes, WT group: 416 mg/dl±21 mg/dl, KD group: 297 mg/dl±16 mg/dl, t=4.49, P=0.005) and insulin sensitivity (15 minutes after insulin injection, WT group: 77.79%±3.45%, KD group: 54.30%±2.92%, t=3.49, P=0.005; 30 minutes, WT group: 62.27%±5.31%, KD group: 42.25%±1.85%, t=2.978, P=0.024; 90 minutes, WT group: 85.69%±6.63%, KD group: 64.71%±5.41%, t=3.120, P=0.016) of KD mice were significantly improved compared to the WT group, with an increase in eWAT weight ratio (WT: 4.19%±0.18%, KD: 5.12%±0.37%, t=2.28, P=0.042), but a decrease in average adipocyte area (WT group: 5221 μm²±241 μm², KD group: 4410 μm²±196 μm², t=2.61, P=0.026). After 7 months of high fat diet, the eWAT weight ratio of KD mice decreased (WT: 5.02%±0.20%, KD: 3.88%±0.21%, t=3.92, P=0.001) and adipocyte size decreased (WT group: 6 783 μm²±390 μm², KD group: 4785 μm²±303 μm², t=4.05, P=0.002). The phospho-ERK1 in eWAT increased (WT group: 0.174±0.056, KD group: 0.588±0.147, t=2.64, P=0.025), and mRNA level of PPARγ significantly decreased (WT group: 1.018±0.128, KD group: 0.029±0.015, t=7.70, P=0.015). (3) The expression of SmgGDS was significantly increased in differentiated MEF (undifferentiated: 6.789±0.511, differentiated: 10.170±0.523, t=4.63, P=0.010); SmgGDS knock-down inhibited lipid droplet formation in MEF (WT group: 1.00±0.02, KD group: 0.88±0.02, t=5.05, P=0.007) and increased ERK1 (WT group: 0.600±0.179, KD group: 1.325±0.102, t=3.52, P=0.025) and ERK2 (WT group: 2.179±0.687, KD group: 5.200±0.814, t=2.84, P=0.047) activity, which can be reversed by ERK1/2 inhibitor. (4) SmgGDS over expression resulted in weight gain, increased eWAT weight (control group: 3.29%±0.36%, AAV-SmgGDS group: 4.27%±0.26%, t=2.20, P=0.048) and adipocyte size (control group: 3525 μm²±454 μm², AAV-SmgGDS group: 5326 μm²±655 μm², t=2.26, P=0.047), impaired insulin sensitivity(30 minutes after insulin injection, control group: 44.03%±4.29%, AAV-SmgGDS group: 62.70%±2.81%, t=3.06, P=0.019), and decreased ERK1 (control group: 0.829±0.077, AAV-SmgGDS group: 0.326±0.036, t=5.96, P=0.001)and ERK2 (control group: 5.748±0.287, AAV-SmgGDS group: 2.999±0.845, t=3.08, P=0.022) activity in eWAT. Conclusion: SmgGDS knockdown improves obesity related glucose metabolism disorder by inhibiting adipogenesis and adipose tissue hypertrophy, which is associated with ERK activation.