1.Circadian mechanisms underlying cardiometabolic dysfunction induced by chronic PM2.5 exposure
Wenqing ZHANG ; Biao WU ; Jianshu GUO ; Dongxia FAN ; Ge WANG ; Lu YU ; Chihang ZHANG ; Xianying LIAO ; Xihao DU ; Yuquan XIE ; Jinzhuo ZHAO
Journal of Environmental and Occupational Medicine 2026;43(8):926-935
Background Long-term exposure to ambient fine particulate matter (PM2.5) is a significant risk factor for cardiometabolic disorders. However, the mechanisms of its interaction with the endogenous circadian system remain incompletely understood. Objective To investigate whether chronic PM2.5 exposure interferes with the rhythmic expression of the cardiac circadian clock, thereby disrupting downstream antioxidant defenses and metabolic homeostasis, and ultimately driving cardiometabolic dysfunction. Methods Seventy-two male C57BL/6 mice were randomly divided into a PM2.5 exposure group (PM group) and a filtered air control group (FA group). Whole-body exposure was conducted for 8 weeks in a meteorological environmental animal exposure system. Samples were collected at six distinct zeitgeber time (ZT) points post-exposure. The 24 h ambulatory blood pressure and serum lipid profiles were monitored. Rhythm parameters were derived via cosinor analysis to compare differences in Midline statistic of rhythm (Mesor), amplitude, and phase between the two groups. The rhythmic expression of core circadian clock genes and antioxidant genes in the myocardium was detected by quantitative polymerase chain reaction (qPCR). Myocardial reactive oxygen species (ROS) levels and downstream pathway protein expression were analyzed by immunofluorescence and Western blot (WB), respectively. The expression changes of the clock gene retinoic acid receptor-related orphan receptor α (RORα) were assessed at both the mRNA and protein levels. Finally, Spearman correlation analysis was used to explore the relationships among myocardial RORα expression, lipid profiles, and oxidative stress indicators. Results Compared to the FA group, mice in the PM group exhibited a blunted circadian rhythm in blood pressure, characterized by sustained elevation throughout the day. Chronic PM2.5 exposure showed a significant interaction with ZT on systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) (F-interaction=9.11, 5.70, and 6.02, respectively; P<0.05), as well as on serum triglycerides (TG), total cholesterol (T-CHO), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) (F-interaction=16.32, 11.12, 15.39, and 28.09, respectively; P<0.05). Cosinor analysis further revealed that the Mesor values of T-CHO, TG, and LDL-C were significantly increased (P<0.05), while that of HDL-C was significantly decreased in the PM group (P<0.05). The oscillation amplitudes of SBP, DBP, and MAP showed a decreasing trend, whereas those of TG and LDL-C were significantly increased (P<0.05). Furthermore, SBP, T-CHO, and HDL-C all exhibited a significant phase delay (P<0.05). Mechanistically, PM2.5 exposure significantly suppressed the expression of the positive circadian regulator RORα in the myocardium, leading to disordered rhythmic expression of core clock genes (Bmal1, Clock, Per1/2, and Cry1/2). This exposure also inhibited the rhythmic expression of antioxidant genes (GPX1, SOD2, and CAT), resulting in increased ROS generation and elevated expression of calcium/calmodulin-dependent protein kinase II (CaMKII) and reduced nicotinamide adenine dinucleotide phosphate (NADPH) proteins. Correlation analysis further revealed that myocardial RORα expression level was negatively correlated with T-CHO, TG, and LDL-C (r=−0.55, −0.63, and −0.51, respectively; P<0.001), and positively correlated with HDL-C (r=0.37, P=0.010), and antioxidant genes GPX1, SOD2, and CAT expression (r=0.34, 0.35, and 0.56, respectively; P < 0.001). Conclusion Chronic PM2.5 exposure induces cardiometabolic dysfunction by suppressing myocardial RORα expression. This suppression disrupts the cardiac circadian clock and the diurnal balance of oxidative stress, triggering oxidative damage and elevating expression of CaMKII/NADPH pathway proteins. Collectively, these alterations precipitate the loss of cardiac metabolic rhythms and subsequent functional impairment.
2.Value of 18F-PSMA-1007 PET/MR and diffusion kurtosis imaging in the diagnosis of prostate cancer and prostatic hyperplasia
Yu ZHANG ; Xinyun HUANG ; Fan FU ; Xiaozhu LIN ; Jin WANG ; Biao LI ; Miao ZHANG ; Hongping MENG
Chinese Journal of Nuclear Medicine and Molecular Imaging 2025;45(7):400-404
Objective:To investigate the value of diffusion kurtosis imaging (DKI) and 18F-prostate specific membrane antigen (PSMA)-1007 in the differential diagnosis of prostate cancer (PCa) and benign prostatic hyperplasia (BPH) by using PET/MR imaging. Methods:From June 2019 to December 2022, a retrospective analysis was conducted on 134 patients ((65.5±10.0) years) with prostate diseases who underwent 18F-PSMA-1007 PET/MR whole-body examination at Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, with the prostate specific antigen (PSA) level continuously rising to >4μg/L within 1 month and not yet receiving treatment. Patients were divided into 2 groups (PSA<10μg/L and PSA≥10μg/L). The PET/MR examination included high b-value diffusion imaging, and the ROI was delineated based on the prostate diffusion weighted imaging (DWI) high-signal area and apparent diffusion coefficient (ADC) low-signal area by the professional radiology physician. The SUV max, mean kurtosis (MK), and mean diffusivity (MD) were obtained. Spearman rank correlation analysis was performed, and ROC curve was used to analyze the diagnostic efficacy. Results:Of 134 patients, 72 were with PSA<10μg/L and 62 were with PSA≥10μg/L. There were 68 patients who obtained biopsy results, including 37 cases of BPH and 31 cases of PCa. In PSA<10μg/L group, there were no significant correlations between MK and SUV max, MK and PSA ( rs values: 0.22, 0.06, P values: 0.065, 0.603). In the PSA≥10μg/L group, there were positive correlations between MK and SUV max, MK and PSA ( rs values: 0.52, 0.40, P values: 0.008, 0.005). In the PSA<10μg/L group, SUV max, MK, and MD showed no diagnostic value (AUCs: 0.44-0.67, all P>0.05), while the AUC for combined diagnosis using these three parameters was 0.78( P=0.008). In the PSA≥10μg/L group, the AUCs of SUV max, MK, and MD were 0.81( P=0.001), 0.84( P<0.001) and 0.72( P=0.023) respectively, and the AUC for combined diagnosis using these three parameters was 0.91( P<0.001). Conclusion:The combination of MK, MD and SUV max improves the diagnostic efficacy of PCa in PET/MR examination.
3.Value of 18F-PSMA-1007 PET/MR and diffusion kurtosis imaging in the diagnosis of prostate cancer and prostatic hyperplasia
Yu ZHANG ; Xinyun HUANG ; Fan FU ; Xiaozhu LIN ; Jin WANG ; Biao LI ; Miao ZHANG ; Hongping MENG
Chinese Journal of Nuclear Medicine and Molecular Imaging 2025;45(7):400-404
Objective:To investigate the value of diffusion kurtosis imaging (DKI) and 18F-prostate specific membrane antigen (PSMA)-1007 in the differential diagnosis of prostate cancer (PCa) and benign prostatic hyperplasia (BPH) by using PET/MR imaging. Methods:From June 2019 to December 2022, a retrospective analysis was conducted on 134 patients ((65.5±10.0) years) with prostate diseases who underwent 18F-PSMA-1007 PET/MR whole-body examination at Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, with the prostate specific antigen (PSA) level continuously rising to >4μg/L within 1 month and not yet receiving treatment. Patients were divided into 2 groups (PSA<10μg/L and PSA≥10μg/L). The PET/MR examination included high b-value diffusion imaging, and the ROI was delineated based on the prostate diffusion weighted imaging (DWI) high-signal area and apparent diffusion coefficient (ADC) low-signal area by the professional radiology physician. The SUV max, mean kurtosis (MK), and mean diffusivity (MD) were obtained. Spearman rank correlation analysis was performed, and ROC curve was used to analyze the diagnostic efficacy. Results:Of 134 patients, 72 were with PSA<10μg/L and 62 were with PSA≥10μg/L. There were 68 patients who obtained biopsy results, including 37 cases of BPH and 31 cases of PCa. In PSA<10μg/L group, there were no significant correlations between MK and SUV max, MK and PSA ( rs values: 0.22, 0.06, P values: 0.065, 0.603). In the PSA≥10μg/L group, there were positive correlations between MK and SUV max, MK and PSA ( rs values: 0.52, 0.40, P values: 0.008, 0.005). In the PSA<10μg/L group, SUV max, MK, and MD showed no diagnostic value (AUCs: 0.44-0.67, all P>0.05), while the AUC for combined diagnosis using these three parameters was 0.78( P=0.008). In the PSA≥10μg/L group, the AUCs of SUV max, MK, and MD were 0.81( P=0.001), 0.84( P<0.001) and 0.72( P=0.023) respectively, and the AUC for combined diagnosis using these three parameters was 0.91( P<0.001). Conclusion:The combination of MK, MD and SUV max improves the diagnostic efficacy of PCa in PET/MR examination.
4.Chemical constituents from Anaphalis margaritacea and their antioxidant activity
Bing-qian LIU ; Biao LI ; Jian-feng CHEN ; Xiao-qin YU ; Cheng-xiong LIU ; Kun ZOU ; Fan CHENG
Chinese Traditional Patent Medicine 2025;47(11):3651-3660
AIM To study the chemical constituents of Anaphalis margaritacea(L.)Benth.& Hook.f.and their antioxidant activities.METHODS Separation and purification were performed using silica gel,Sephadex LH-20 and semi-preparative HPLC,then the structures of obtained compounds were identified by physicochemical properties and spectral data.The antioxidant activity was determined by DPPH method and ABTS method.RESULTS Twenty-three compounds were isolated and identified as trans-tilidroside(1),4'-hydroxydehydrokawain(2),apigenin(3),3-O-kaempferol-3-O-acetyl-6-O-(p-coumamoyl)-α-D-glucopyranoside(4),kaempferol(5),quercetin-3-O-β-D-(6-O-Z-p-coumamoyl)-glucopyranoside(6),tiliroside(7),kaempferol-3-O-β-D-glucoside(8),3,5-dihydroxy-7,8-dimethoxyflavone(9),bis(2-ethylhexyl)adipate(10),3,5-dihydroxy-6,7,8-trimethoxyflavone(11),stigmasterol(12),myriophylloside B(13),1-hexadecanol(14),chlorogenic acid(15),4-hydroxy-N-{ 4-[3-(4-hydroxyphenyl)-E-acryloylamino]-butyl}-benzamide(16),3,6-dimethylpiperazine-2,5-dione(17),β-adenosine(18),5,6-dehydrokawain(19),kaempferol-3-O-(2",6"-di-O-E-p-coumaroyl)-β-D-glucopyranoside(20),kaempferol-3-O-(3"-O-E-p-coumaroyl)-(6"-O-E-feruloyl)-β-D-glucopyranoside(21),4,5-di-caffeoylquinic acid butyl ester(22),3,4-di-caffeoylquinic acid butyl ester(23).The IC50 values of compounds 1,7,22-23 against DPPH free radicals were(24.67±1.63)-(53.41±1.61)μmol/L,and the IC50 values of compounds 8,21-23 against ABTS+free radicals were(15.22±0.89)-(41.66±6.29)μmol/L.CONCLUSION Compounds 9,19-23 are isolated from genus Anaphalis for the first time,and 2,10,13,14,16,17,19-23 are first isolated from this plant.Compounds 1,7-8,21-23 have strong antioxidant activity.
5.Chemical constituents from Anaphalis margaritacea and their antioxidant activity
Bing-qian LIU ; Biao LI ; Jian-feng CHEN ; Xiao-qin YU ; Cheng-xiong LIU ; Kun ZOU ; Fan CHENG
Chinese Traditional Patent Medicine 2025;47(11):3651-3660
AIM To study the chemical constituents of Anaphalis margaritacea(L.)Benth.& Hook.f.and their antioxidant activities.METHODS Separation and purification were performed using silica gel,Sephadex LH-20 and semi-preparative HPLC,then the structures of obtained compounds were identified by physicochemical properties and spectral data.The antioxidant activity was determined by DPPH method and ABTS method.RESULTS Twenty-three compounds were isolated and identified as trans-tilidroside(1),4'-hydroxydehydrokawain(2),apigenin(3),3-O-kaempferol-3-O-acetyl-6-O-(p-coumamoyl)-α-D-glucopyranoside(4),kaempferol(5),quercetin-3-O-β-D-(6-O-Z-p-coumamoyl)-glucopyranoside(6),tiliroside(7),kaempferol-3-O-β-D-glucoside(8),3,5-dihydroxy-7,8-dimethoxyflavone(9),bis(2-ethylhexyl)adipate(10),3,5-dihydroxy-6,7,8-trimethoxyflavone(11),stigmasterol(12),myriophylloside B(13),1-hexadecanol(14),chlorogenic acid(15),4-hydroxy-N-{ 4-[3-(4-hydroxyphenyl)-E-acryloylamino]-butyl}-benzamide(16),3,6-dimethylpiperazine-2,5-dione(17),β-adenosine(18),5,6-dehydrokawain(19),kaempferol-3-O-(2",6"-di-O-E-p-coumaroyl)-β-D-glucopyranoside(20),kaempferol-3-O-(3"-O-E-p-coumaroyl)-(6"-O-E-feruloyl)-β-D-glucopyranoside(21),4,5-di-caffeoylquinic acid butyl ester(22),3,4-di-caffeoylquinic acid butyl ester(23).The IC50 values of compounds 1,7,22-23 against DPPH free radicals were(24.67±1.63)-(53.41±1.61)μmol/L,and the IC50 values of compounds 8,21-23 against ABTS+free radicals were(15.22±0.89)-(41.66±6.29)μmol/L.CONCLUSION Compounds 9,19-23 are isolated from genus Anaphalis for the first time,and 2,10,13,14,16,17,19-23 are first isolated from this plant.Compounds 1,7-8,21-23 have strong antioxidant activity.
6.Construction of CRISPR/Cas9 knock-in system for tardigrade damage suppressor gene Dsup and its effect on HEK 293T cell proliferation
Yuting GAO ; Biao ZHANG ; Yali JIA ; Haiyang WANG ; Tao FAN ; Jiafei XI ; Wen YUE ; Quan ZENG ; Junnian ZHOU
Military Medical Sciences 2024;48(8):586-593
Objective To construct HEK 293T cells that express tardigrade Dsup protein fused with green fluorescent protein copGFP in order to study the effect of Dsup protein on proliferation of HEK 293T cells.Methods The CRISPR/Cas9 gene knock-in system was constructed.The target gene fragments of Dsup,copGFP,EF1α and puromycin were amplified by PCR and inserted into pAAVS1-SFFV to construct the fusion vector of Dsup and copGFP,which was known as pAAVS1-SFFV-Dsup-copGFP-EF1α-Puro.pAAVS1-SFFV-Dsup-copGFP-EF1 α-Puro and pAAVS1-CRISPR-Cas9 vector were co-transfected into HEK 293T cells before Dsup gene was inserted into the AAVS1 region of HEK 293T cells via homologous recombination.The HEK 293T cells expressing Dsup gene were obtained following puromycin selection,flow cytometry sorting and genome identification.The expression of Dsup at mRNA and protein levels and proliferation-related genes(MCM2,MCM4,PCNA,Ki-67)were examined to investigate the effects of Dsup gene on the proliferation of HEK 293T-Dsup-copGFP cells.Results The pAAVS1-SFFV-Dsup-copGFP-EF1α-Puro recombinant vector was constructed,and the HEK 293T-Dsup-copGFP cells with Dsup gene inserted in the AAVS1 region were obtained,where both Dsup mRNA and protein were expressed.The cell proliferation rate of HEK 293T-Dsup-copGFP was higher than that of HEK 293T-Control-copGFP(P<0.001).Further investigation revealed that the expressions of Ki-67 and MCM4 protein in HEK 293T-Dsup-copGFP were significantly higher than in the control group,indicating that the knock in of Dsup gene might enhance the proliferation ability of human cells by promoting the expression of Ki-67 and MCM4 protein.Conclusion A gene editing vector is constructed,and stable cell line HEK 293T-Dsup-copGFP for Dsup fusion expression with copGFP is established.The expression of Dsup gene in HEK 293T cells can promote cell proliferation,possibly by upregulating the expressions of Ki-67 and MCM4 protein.
7.Study of acetyl-11-keto-3-boswellic acid inhibiting oral squamous cell carcinoma
Xin-Bang HUANG ; Yu WANG ; Qian YU ; Yong LI ; Biao-Dong LI ; Hai-Lei HE ; Kun CHEN ; Ling-Fan ZHAO
The Chinese Journal of Clinical Pharmacology 2024;40(20):2993-2997
Objective To investigate the mechanism of apoptosis induced by acetyl-11-keto-3-boswellic acid(AKBA)in oral squamous cell carcinoma(OSCC)cells.Methods CAL27 were randomly divided into control group(conventional culture),low-dose group(40.00 μmol·L-1 AKBA),middle-dose group(80.00 μmol·L-1 AKBA),high-dose group(120.00 μmol·L-1 AKBA),3-methyladenine(3-MA)group(120.00 μmol·L-1 AKBA+2 mmol·L-1 autophagy inhibitor 3-MA).5-ethynyl-2'-deoxyuridine(Edu)assay was used to detect cell proliferation;Western blot assay was used to detect protein expression;flow cytometry was used to detect apoptosis.Mice were randomly divided into model group(construct OSCC mouse model),AKBA-L group(10.00 mg·kg-1 AKBA after modeling),AKBA-H group(20.00 mg·kg-1 AKBA after modeling),10 animals per group.After 28 days of continuous administration,weight were detected;and the expression of related proteins were detected by Western blot assay.Results The Edu positive cell rates in control group,high-dose group were(40.18±2.53)%,(12.08±0.93)%,respectively;the protein levels of autophagy associated microtubule associated protein 1 light chain 3(LC3)Ⅱ/LC3 Ⅰ in control group,high-dose group and 3-MA group were 0.33±0.05,2.93±0.39,0.56±0.07,respectively;phosphorylated adenylate activated protein kinase catalytic subunit alpha subunit 1(p-PRKAA1)protein levels were 0.34±0.04,1.03±0.07,0.99±0.09,respectively;the apoptosis rates were(4.65±0.39)%,(25.75±2.29)%,(14.92±1.49)%,respectively.The above indexes in hige-dose group were significantly different from those in the control group(all P<0.05).The above indexes in 3-MA group were significantly different from those in high-dose group(all P<0.05).The tumor weight of model group,AKBA-L group and AKBA-H group were(0.96±0.08),(0.55±0.06),(0.43±0.05)g,respectively;the protein levels of LC3 Ⅱ/LC3 Ⅰ were 0.47±0.09,0.94±0.21 and 1.69±0.34,respectively.The above indexes in AKBA-L group and AKBA-H group were significantly different from those in model group(all P<0.05).Conclusion AKBA can induce cytotoxic autophagy related apoptosis and inhibit CAL27 cell proliferation,which may be related to activation of AMPK signal.
8.Application of miniprobe endoscopic ultrasound in endoscopic surgery of small-diameter and low-grade rectum neuroendocrine neoplasm
Jian-Jun LI ; Chao-Qiang FAN ; Xin YANG ; Xue PENG ; Hao LIN ; Xu-Biao NIE ; Shi-Ming YANG ; Qiu-Jian QIAO ; Jian-Ying BAI
Journal of Regional Anatomy and Operative Surgery 2024;33(1):59-62
Objective To evaluate the value of miniprobe endoscopic ultrasound(EUS)in guiding endoscopic treatment of small-diameter(maximum diameter less than 1 cm)and low-grade(G1 grade)rectum neuroendocrine neoplasm(R-NEN),and to provide evidence and clues for its clinical application and further research.Methods The clinical data of 85 cases of low-grade(G1 grade)R-NEN with a maximum diameter of less than 1 cm who underwent endoscopic treatment in our center from January 2014 to December 2020 were retrospectively analyzed.The patients were divided into the EUS group(37 cases)and control group(48 cases)according to whether EUS was performed before endoscopic treatment.The positive rate of incision margin,the incidence of complications,the recurrence rate,the hospital stay,the cost of hospitalization and endoscopic therapy were compared between the two groups.Results The positive rate of incision margin in the EUS group was significantly lower than that in control group(P<0.05).There was no significant difference in the incidence of complications,tumor recurrence rate,hospital stay or hospital costs between the two groups(P>0.05).There was statistically significant difference in the endoscopic therapy between the two groups(P<0.05).Conclusion Evaluating the lesion depth of small-diameter and low-grade(G1 grade)R-NEN before surgery by miniprobe EUS and selecting endoscopic surgery according to its results of can significantly reduce the residual risk of resection margin tumors.
9.Molecular mechanism of adipose tissue inflammation induced by acute exposure to cooking oil fumes
Ge WANG ; Biao WU ; Jianshu GUO ; Dongxia FAN ; Lu YU ; Chihang ZHANG ; Lan MI ; Lina WANG ; Jinzhuo ZHAO
Journal of Environmental and Occupational Medicine 2024;41(4):349-355
Background Cooking oil fumes are closely related to immune response, and adipose tissue also plays an important role in immune regulation. At present, the biological effect and mechanism of inflammation of adipose tissue induced by oil fume exposure are not clear yet. Objective To investigate the inflammatory effect of different exposure duration of cooking fumes on adipose tissue in mice and explore the role of Nod-like receptor pyrin domain 3 (NLRP3)/cysteinyl aspartate specific proteinase 1 (Caspase 1)/interleukin (IL)-1β signaling pathway. Methods Forty 8-week-old female C57BL/6J mice were randomly divided into 3-day control group (CON3 group), 7-day control group (CON7 group), 3-day oil fume exposure group (COF3 group), and 7-day oil fume exposure group (COF7 group), with 10 mice in each group. The mice were exposed to oil fumes in a cooking oil fume formation and exposure equipment (COFFEE) for 20 min, followed by a 10-min pause, 1 h a day for consecutive 3 d or 7 d. General condition of mice was observed and body weight was measured every day. After exposure, blood was sampled from the eyeball. Serum levels of IL-6, IL-27, and IL-1β were detected by enzyme-linked immunosorbent assay (ELISA). The adipose tissue of mice was collected and observed after hematoxylin-eosin (HE) staining. The percentages of CD4+ and CD8+T cells in adipose tissue were detected by flow cytometry. Real-time quantitative PCR (RT-qPCR) was used to detect the expression levels of nuclear factor-κB (NF-κB), NLRP3, Caspase 1, and IL-1β in adipose tissue. Western blot was used to detect the expression levels of NLRP3, Caspase 1, and IL-1β in adipose. Results Compared with the corresponding control group, serum IL-6, IL-27, and IL-1β contents in the COF3 group and the COF7 group were significantly increased (P<0.05) except IL-6 in the COF3 group, and the levels in the COF7 group were significantly higher than those in the COF3 group (P<0.05). Vacuolar lipid droplets in adipocytes decreased, cytoplasm shrank, and inflammatory cells infiltrated in the COF7 group after HE staining. The flow cytometry results showed that the proportions of CD4+ and CD8+T cells in adipocytes of the COF3 group and the COF7 group were increased compared to the corresponding control group, with a significant increase in the COF7 group (P<0.05), and the CD4+/CD8+T ratio also significantly increased progressively in the two groups (P<0.05). The results of RT-qPCR showed that compared with the corresponding control group, the mRNA expression levels of NF-κB, NLRP3, Caspase 1, and IL-1β in adipose tissue of mice in the COF3 group and the COF7 group were significantly increased (P<0.05, P<0.01). The mRNA expression levels of mice in each exposure group gradually increased over time. The Western blot results showed that compared with the corresponding control group, the protein expressions of NLRP3 and Caspase 1 in the COF3 group were significantly increased (P<0.01), and the expression of IL-1β protein also increased but without statistical significance. The protein expressions of NLRP3, Caspase 1, and IL-1β in the COF7 group were significantly higher than those in the CON7 group (P<0.05, P<0.01). Conclusion Acute exposure to cooking oil fumes can induce significant inflammatory response in adipose tissue, and the effect gradually increases with the extension of exposure time. The mechanism of action may be related to the activation of NLRP3 inflammasome signaling pathway.
10.Effects of PM2.5 and heat/cold exposure on AKT/GLUT4 pathway in mouse skeletal muscle and white adipose tissue
Biao WU ; Dongxia FAN ; Jia ZHANG ; Jianshu GUO ; Ge WANG ; Lu YU ; Chihang ZHANG ; Jinzhuo ZHAO
Journal of Environmental and Occupational Medicine 2024;41(4):356-361
Background It is unclear if there is any combined effect of air pollutants and non-optimal temperature on metabolic syndrome, or any molecular mechanisms of related signaling pathways in the process, which requires urgent systematic research. Objective To observe the effects of combined exposure to PM2.5 and non-optimal temperature on metabolic damage at gene and protein levels in mice, and elucidate the role of related signaling pathway in crucial organs. Methods A total of 60 six-week-old male C57BL/6J mice were randomly divided into six groups: a normal temperature-filter air group (TN-FA), a normal temperature-concentrated PM2.5 group (TN-PM), a heat-filter air group (TH-FA), a heat-concentrated PM2.5 group (TH-PM), a cold-filter air group (TC-FA), and a cold-concentrated PM2.5 group (TC-PM). The Shanghai Meteorological and Environmental Animal Exposure System (Shanghai-METAS) was used to provide combined exposure settings of air types [concentrated PM2.5 and filter air (FA)] and temperatures [normal (22°C), cold (4°C), and heat (30°C)] for 4 weeks. Skeletal muscle and white adipose tissue (WAT) of the mice were sampled at the end of exposure, and transcriptomics and Western blot (WB) assay were adopted to observe selected gene and protein expression levels in the samples respectively. Results The transcriptomics results indicated that the PM2.5 exposure enhanced the number of differentially expressed genes. Specifically, 4820 genes were differentially expressed in the TN-PM mice compared to the TN-FA mice at normal temperature, and 1143 genes were differentially expressed in the Tc-PM mice compared to the Tc-FA mice in the cold environment. The phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway and the endoplasmic reticulum protein processing pathway were identified as the most significant pathways in metabolic injury resulting from combined exposure to PM2.5 and non-optimal temperature exposure. The WB results showed that exposure to PM2.5 in the normal temperature and the cold environments led to a significant increase in the expression of p-AKT in WAT (P<0.01, P<0.05) and a significant decrease in the expression of GLUT4 (P<0.05, P<0.01). In skeletal muscle, exposure to PM2.5 led to a significant decrease in GLUT4 (P<0.05) in all environments, with a consistent trend of change as observed in WAT. Conclusion Cold/heat exposure might promote PM2.5-induced metabolic disorder through suppression of the AKT/GLUT4 pathway, aggravating metabolic damage.

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