1.Threshold of kurtosis on occupational hearing loss associated with non-steady noise
Yang LI ; Haiying LIU ; Linjie WU ; Jinzhe LI ; Jiarui XIN ; Hua ZOU ; Xin SUN ; Wei QIU ; Changyan YU ; Meibian ZHANG
Journal of Environmental and Occupational Medicine 2025;42(7):779-785
Background Kurtosis reflecting noise's temporal structure is an effective metric for evaluating noise-induced hearing loss (NIHL), and its threshold is still unclear. Objective To explore the energy range of kurtosis and the threshold of NIHL induced by kurtosis in this energy rangeMethods Using cross-sectional design,
2.Roles of A- and C-weighted kurtosis adjustment for equivalent sound level in evaluating occupational hearing loss
Haiying LIU ; Linjie WU ; Yang LI ; Jinzhe LI ; Jiarui XIN ; Hua ZOU ; Wei QIU ; Tong SHEN ; Meibian ZHANG
Journal of Environmental and Occupational Medicine 2025;42(7):793-799
Background Temporal kurtosis (without frequency weighting, i.e., Z-weighted kurtosis) can evaluate noise-induced hearing loss (NIHL). However, few studies have considered the function of frequency weighting (A- or C-weighted) kurtosis on NIHL. Objective To study the significance of A- and C-weighted kurtosis adjustment for equivalent sound level (L'EX,8 h) in evaluating occupational hearing loss. Methods A cross-sectional survey was used to select 973 noise-exposed workers in seven industries as the subjects. The noise exposure of all workers was assessed by distributions of A-, C-, and Z-weighted kurtosis (e.g., KA, KC, and KZ) and respective adjusted equivalent sound level (e.g., L'EX,8 h-KA, L'EX,8 h-KC, and L'EX,8 h-KZ). The significance of A- and C-weighted kurtosis in evaluating NIHL was evaluated by correlations between three types of L'EX,8 h and NIHL, and improvement of noise-induced permanent threshold shift (NIPTS) underestimation predicted by the ISO prediction model (Acoustics—Estimation of noise-induced hearing loss, ISO 1999-2013). Results The median KA, KC, and KZ were 68.33, 28.22, and 19.82, respectively. The binary logistic regression showed that LEX, 8 h-KA, LEX, 8 h-KC, and L'EX, 8 h-KZ were risk factors for NIHL (OR>1, P<0.001). The receiver operating characteristic (ROC) curve showed that when the outcome variable was noise-induced hearing impairment (NIHI), the areas under the curves corresponding to L'EX,8 h-KA, L'EX,8 h-KC, and L'EX,8 h-KZ were 0.625, 0.628, and 0.625, respectively. When the outcome variable was high-frequency noise-induced hearing loss (HFNIHL), the areas under the curves corresponding to L'EX,8 h-KA, L'EX, 8 h-KC, and L'EX,8 h-KZ were 0.624, 0.623, and 0.622, respectively (P<0.05). The order of underestimation improvement values predicted by L'EX,8 h for NIPTS1234 was: L'EX,8 h-KA (4.68 dB HL)>L'EX,8 h-KC (4.38 dB HL)>L'EX,8 h-KZ (4.28 dB HL) (P<0.001). The order of underestimation improvement values predicted by L'EX,8 h-K for NIPTS346 was: L'EX,8 h-KA (7.20 dB HL)>L'EX,8 h-KC (6.83 dB HL)>L'EX,8 h-KZ (6.71 dB HL) (P<0.001). Conclusion The adjustment of A- and C-weighted kurtosis to equivalent sound level LEX,8 h can effectively improve the accuracy of the ISO 1999 prediction model in NIPTS prediction, and compared with the C-weighted, the A-weighted kurtosis can improve the result of the ISO 1999 prediction model in terms of underestimating NIPTS.
3.A preliminary study on developing statistical distribution table of hearing threshold deviation for otologically normal Chinese adults
Linjie WU ; Yang LI ; Haiying LIU ; Anke ZENG ; Jinzhe LI ; Wei QIU ; Hua ZOU ; Meng YE ; Meibian ZHANG
Journal of Environmental and Occupational Medicine 2025;42(7):800-807
background Current assessment of noise-induced hearing loss relies on the hearing threshold statistical distribution table of ISO 7029-2017 standard (ISO 7029), which is based on foreign population data and lacks a hearing threshold distribution table derived from pure-tone audiometry data of the Chinese population, hindering accurate evaluation of hearing loss in this group. Objective To establish a statistical distribution table of hearing threshold level (HTL) for otologically normal Chinese adults and to provide a scientific basis for revising the diagnostic criteria of occupational noise-induced deafness in China. Methods A total of
4.Triglyceride-glucose index and homocysteine in association with the risk of stroke in middle-aged and elderly diabetic populations
Xiaolin LIU ; Jin ZHANG ; Zhitao LI ; Xiaonan WANG ; Juzhong KE ; Kang WU ; Hua QIU ; Qingping LIU ; Jiahui SONG ; Jiaojiao GAO ; Yang LIU ; Qian XU ; Yi ZHOU ; Xiaonan RUAN
Shanghai Journal of Preventive Medicine 2025;37(6):515-520
ObjectiveTo investigate the triglyceride-glucose (TyG) index and the level of serum homocysteine (Hcy) in association with the incidence of stroke in type 2 diabetes mellitus (T2DM) patients. MethodsBased on the chronic disease risk factor surveillance cohort in Pudong New Area, Shanghai, excluding those with stroke in baseline survey, T2DM patients who joined the cohort from January 2016 to October 2020 were selected as the research subjects. During the follow-up period, a total of 318 new-onset ischemic stroke patients were selected as the case group, and a total of 318 individuals matched by gender without stroke were selected as the control group. The Cox proportional hazards regression model was used to adjust for confounding factors and explore the serum TyG index and the Hcy biochemical indicator in association with the risk of stroke. ResultsThe Cox proportional hazards regression results showed that after adjusting for confounding factors, the risk of stroke in T2DM patients with 10 μmol·L⁻¹
5.Health risk assessment of per- and polyfluoroalkyl substances contamination in animal-derived foods in Shanghai
Chenlin GU ; Jingjin YANG ; Baozhang LUO ; Danping QIU ; Hong LIU ; Hua CAI
Shanghai Journal of Preventive Medicine 2025;37(7):556-561
ObjectiveTo analyze the current status of per⁃ and polyfluoroalkyl substances (PFASs) contamination in animal⁃derived foods in Shanghai and to assess the risk of dietary exposure among local residents, thereby providing a scientific basis for future dietary safety and risk management. MethodsA total of 300 commonly consumed animal⁃derived food samples were collected in Shanghai in 2023 and tested for 17 types of PFASs. Based on local dietary consumption data, the weekly exposure intake (EWI) of four representative PFASs was calculated using the exposure assessment model recommended by Food and Agriculture Organization (FAO) and the World Health Organization (WHO). The calculated EWI was compared with the tolerable weekly intake (TWI) set by the European Food Safety Authority (EFSA) to assess the health risks associated with dietary intake of PFASs. ResultsThe predominant PFASs detected in aquatic products were PFUnDA (98.67%), PFTrDA (98.00%), and PFOS (95.33%), with PFUnDA having the highest median mass fraction (0.378 ng·g-1). In meat samples, PFBA (54.17%), PFOA (20.83%), and PFOS (18.33%) were mainly detected, with PFBA showing the highest median mass fraction (0.027 ng·g-1). In egg samples, the most frequently detected compounds were PFBA (90.00%), PFOA (63.33%), PFOS (50.00%), PFDA (50.00%), PFNA (50.00%), and PFHxDA (50.00%), with PFBA again having the highest median mass fraction (0.068 ng·g-1). The median mass fractions of the four key PFASs (PFOA, PFOS, PFNA, and PFHxS) in aquatic products were significantly higher than those in meat products and eggs (all P<0.001), and there were statistically significant differences in the median mass fractions of the four PFASs among different types of aquatic products (all P<0.05). The EWI of the four PFASs was 2.970 ng·kg-1 for the mean consumption group and 6.676 ng·kg-1 for the high consumption group (P95), with females having higher EWI values than males. ConclusionPFOS, PFOA, and PFBA are the major PFAS contaminants in animal⁃derived foods consumed by Shanghai residents, with aquatic products having the highest levels of contamination. The EWIs of four PFASs among Shanghai residents did not exceed EFSA’s recommended TWI at average consumption levels. However, the EWIs for high⁃consumption populations exceeded the EFSA⁃recommended TWI, posing potential health risks to these populations. Aquatic products contribute the most to dietary PFAS exposure. It is necessary to strengthen PFAS monitoring in aquatic products and conduct targeted risk assessments for high⁃consumption groups.
6.Analysis of T7 RNA Polymerase: From Structure-function Relationship to dsRNA Challenge and Biotechnological Applications
Wei-Chen NING ; Yu HUA ; Hui-Ling YOU ; Qiu-Shi LI ; Yao WU ; Yun-Long LIU ; Zhen-Xin HU
Progress in Biochemistry and Biophysics 2025;52(9):2280-2294
T7 RNA polymerase (T7 RNAP) is one of the simplest known RNA polymerases. Its unique structural features make it a critical model for studying the mechanisms of RNA synthesis. This review systematically examines the static crystal structure of T7 RNAP, beginning with an in-depth examination of its characteristic “thumb”, “palm”, and “finger” domains, which form the classic “right-hand-like” architecture. By detailing these structural elements, this review establishes a foundation for understanding the overall organization of T7 RNAP. This review systematically maps the functional roles of secondary structural elements and their subdomains in transcriptional catalysis, progressively elucidating the fundamental relationships between structure and function. Further, the intrinsic flexibility of T7 RNAP and its applications in research are also discussed. Additionally, the review presents the structural diagrams of the enzyme at different stages of the transcription process, and through these diagrams, it provides a detailed description of the complete transcription process of T7 RNAP. By integrating structural dynamics and kinetics analyses, the review constructs a comprehensive framework that bridges static structure to dynamic processes. Despite its advantages, T7 RNAP has a notable limitation: it generates double-stranded RNA (dsRNA) as a byproduct. The presence of dsRNA not only compromises the purity of mRNA products but also elicits nonspecific immune responses, which pose significant challenges for biotechnological and therapeutic applications. The review provides a detailed exploration of the mechanisms underlying dsRNA formation during T7 RNAP catalysis, reviews current strategies to mitigate this issue, and highlights recent progress in the field. A key focus is the semi-rational design of T7 RNAP mutants engineered to minimize dsRNA generation and enhance catalytic performance. Beyond its role in transcription, T7 RNAP exhibits rapid development and extensive application in fields, including gene editing, biosensing, and mRNA vaccines. This review systematically examines the structure-function relationships of T7 RNAP, elucidates the mechanisms of dsRNA formation, and discusses engineering strategies to optimize its performance. It further explores the engineering optimization and functional expansion of T7 RNAP. Furthermore, this review also addresses the pressing issues that currently need resolution, discusses the major challenges in the practical application of T7 RNAP, and provides an outlook on potential future research directions. In summary, this review provides a comprehensive analysis of T7 RNAP, ranging from its structural architecture to cutting-edge applications. We systematically examine: (1) the characteristic right-hand domains (thumb, palm, fingers) that define its minimalistic structure; (2) the structure-function relationships underlying transcriptional catalysis; and (3) the dynamic transitions during the complete transcription cycle. While highlighting T7 RNAP’s versatility in gene editing, biosensing, and mRNA vaccine production, we critically address its major limitation—dsRNA byproduct formation—and evaluate engineering solutions including semi-rationally designed mutants. By synthesizing current knowledge and identifying key challenges, this work aims to provide novel insights for the development and application of T7 RNAP and to foster further thought and progress in related fields.
7.Deoxynivalenol contamination in cereals and bakery products in Shanghai and dietary exposure assessment in pregnant women
Kailin LI ; Baozhang LUO ; Renjie QI ; Hua CAI ; Xia SONG ; Jingjin YANG ; Danping QIU ; Zhenni ZHU ; Yi HE ; Hong LIU
Journal of Environmental and Occupational Medicine 2025;42(10):1170-1176
Background Deoxynivalenol (DON), a priority contaminant for food safety risk monitoring, is produced by Fusarium spp. infesting crops, and its common derivatives are 3-acetyl-DON (3A-DON) and 15-acetyl-DON (15A-DON), which have been shown to possess gastrointestinal toxicity, immunotoxicity, reproductive toxicity, and cytotoxicity. Due to the stable physicochemical properties of the DON family of toxins (DONs), they cannot be effectively removed during food processing, thus following the food chain, entering the human body, and posing health risks. Objective To understand the contamination status of DONs in commercial foods (cereals and bakery products) in Shanghai in 2022–2023, and to assess the exposure risk of DONs in pregnant women by combining their dietary consumption data. Methods Liquid chromatography tandem mass spectrometry (LC-MS/MS) was used to determine the contamination level of DONs in 1 100 food samples (cereals and baked goods) collected in 2022 and 944 samples collected in 2023 from Shanghai. The dietary monitoring data of pregnant women in Shanghai from 2016 to 2017 were adopted. The monitoring employed the food frequency questionnaire distributed among pregnant women through a combination of online telephone enquiry and offline on-site face-to-face survey to estimate their food consumption levels. An exposure assessment model was established to calculate the exposure level to DONs, and the probability distribution of the DONs exposure level in the pregnant women group in Shanghai was obtained by applying @Risk 7.5 software and simulating the calculation according to the Monte Carlo principle. With reference to the tolerable daily intake (TDI) of DONs [1.00 µg·(kg·d)−1] proposed by the Joint FAO/WHO Expert Committee on Food Additives, the risk of exposure to DONs from commercial cereals and bakery products in pregnant women in Shanghai was assessed. Results DONs were detected in cereal and bakery samples collected in 2022 and 2023 with different levels of contamination. The level of DONs in cereal foods in 2023 (mean: 36.33 µg·kg−1) decreased compared to 2022 (mean: 23.64 µg·kg−1). However, the positive rate (71.67%) and level (mean: 51.22 µg·kg−1) of DONs in bakery products increased significantly compared with 2022 (positive rate: 10.00%, mean: 24.39 µg·kg−1). The mean consumption of cereals in 783 pregnant women was 222.48 g·d−1 and the mean consumption of bakery products was 36.07 g·d−1, and there was no statistically significant difference in the intake of all types of cereals and bakery products across the early, middle, and late stages of pregnancy. The modelled intakes of DONs via commercial cereals and bakery products for pregnant women in Shanghai were calculated to be 0.20 and 0.57 µg·(kg·d)−1 in 2022 for the mean level and the 95th percentile level, respectively, and 0.16 µg·(kg·d)−1 and 0.35 µg·(kg·d)−1 in 2023, respectively. The results of the health risk assessment showed that pregnant women in Shanghai had 2.6% and 1.4% probability of exposure to DONs from cereal consumption in 2022 and 2023, respectively. Conclusion The risk of exposure of pregnant women in Shanghai to DONs via commercial cereals and bakery products is relatively low (1.4%-2.6%). However, considering the physical sensitivity of pregnant women, they should avoid consuming moldy grains and appropriately reduce intake of bakery products.
8.Antibacterial activity of the antifungal peptide Mt6 - 21DLeu derived from Musca domestica against Acinetobacter baumannii and the underlying mechanisms
Xuan HUA ; Tong QIU ; Xuyuan WANG ; Renxian TANG ; Delong KONG
Chinese Journal of Schistosomiasis Control 2025;37(5):482-493
Objective To investigate the antibacterial activity of the antifungal peptide Mt6-21DLeu derived from Musca domestica against Acinetobacter baumannii (AB) and unravel its underlying mechanisms, so as to provide insights into development of novel agents against AB. Methods The minimum inhibitory concentrations (MICs) of Mt6-21DLeu, M. domestica-derived antifungal peptide-1 (MAF-1A), and polymyxin B were determined against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and AB using the broth microdilution assay, and the antibacterial activity of Mt6-21DLeu and polymyxin B was dynamically assessed against AB over 24 hours with time-kill curves. The inhibitory effects of Mt6-21DLeu and polymyxin B on biofilm formation in AB at concentrations of 1/4 × MIC, 1/2 × MIC and MIC, and the eradication effects of Mt6-21DLeu and polymyxin B on mature biofilms in AB at concentrations of MIC, 2 × MIC, and 4 × MIC were evaluated using crystal violet staining. Structural changes in the cell membrane of AB were observed 3 hours post-exposure to Mt6-21DLeu at concentrations of MIC and 2 × MIC using scanning electron microscopy, and alterations in the cell membrane permeability of AB were analyzed 3 hours post-treatment with Mt6-21DLeu at concentrations of MIC and 2 × MIC by means of fluorescence microscopy and propidium iodide (PI) staining. Intracellular reactive oxygen species (ROS) levels in AB were measured 3 hours post-treatment with Mt6-21DLeu at concentrations of MIC, 2 × MIC, and 4 × MIC using flow cytometry. The survival of Caenorhabditis elegans exposed to Mt6-21DLeu at concentrations of MIC, 2 × MIC, and 4 × MIC was monitored for 7 consecutive days, and survival curves were plotted to evaluate the in vivo toxicity of Mt6-21DLeu. In addition, C. elegans infected with AB and treated with Mt6-21DLeu at a concentration of 4 × MIC served as the treatment group, and uninfected C. elegans served as the control group, while infected but untreated C. elegans served as the infection group. The in vivo antibacterial efficacy of Mt6-21DLeu at a concentration of 4 × MIC was evaluated by comparing the survival curves and bacterial load among the three groups. Results The MICs of MAF-1A were all >128 μg/mL against S. aureus, B. subtilis, E. coli, K. pneumoniae, P. aeruginosa, and AB. In contrast, the MICs of Mt6-21DLeu were >128, 32, 8, 8, 16, and 4 μg/mL against these strains, respectively, and the MIC of Mt6-21DLeu against AB was close to that of polymyxin B (2 μg/mL). Time-kill curve analysis showed that both Mt6-21DLeu at concentrations of MIC and 2 × MIC and polymyxin B at a concentration of MIC inhibited AB growth over the 24-hour study period. The biofilm biomass in AB was (52.38 ± 6.92)%, (40.88 ± 9.17)% and (14.77 ± 6.00)% post-exposure with Mt6-21DLeu at concentrations of 1/4 × MIC, 1/2 × MIC and MIC, (61.58 ± 7.35)%, (47.42 ± 5.51)% and (20.85 ± 10.48)% post-treatment with polymyxin B at concentrations of 1/4 × MIC, 1/2 × MIC and MIC, and (100.00 ± 15.92)% in the control group (only bacterial suspension), respectively (F = 68.38, P < 0.001), and pairwise comparisons indicated that Mt6-21DLeu and polymyxin B at all concentrations significantly inhibited biofilm formation as compared to the control group (all P values < 0.001). The mature biofilm biomass in AB was (73.44 ± 11.41)%, (72.56 ± 13.08)% and (49.65 ± 9.23)% post-exposure to Mt6-21DLeu at concentrations of MIC, 2 × MIC, and 4 × MIC, (84.38 ± 8.60)%, (72.31 ± 9.63)% and (58.85 ± 4.96)% post-treatment with polymyxin B at concentrations of MIC, 2 × MIC, and 4 × MIC, and (100.00 ± 6.36)% in the control group (F = 35.63, P < 0.001), and pairwise comparisons revealed that Mt6-21DLeu at all concentrations significantly eradicated biofilm biomass (all P values < 0.05); however, polymyxin B showed no clear-cut eradication effect at a concentration of MIC (P > 0.05). Scanning electron microscopy revealed pore formation and content leakage in the cell membrane of AB 3 hours post-treatment with Mt6-21DLeu at concentrations of MIC and 2 × MIC. Fluorescence microscopy showed that the proportions of PI-stained AB were (24.79 ± 11.51)% and (68.44 ± 15.80)% post-treatment with Mt6-21DLeu at concentrations of MIC and 2 × MIC, and (0.96 ± 0.94)% in the phosphate-buffered saline (PBS) treatment group (F = 105.90, P < 0.001), with the highest proportion of PI-stained AB seen post-treatment with Mt6-21DLeu at a concentration of 2 × MIC (P < 0.05). Flow cytometry revealed that the relative intracellular ROS levels in AB were (652.00 ± 141.90), (694.33 ± 14.19), and (974.33 ± 160.02) 3 hours post-treatment with Mt6-21DLeu at concentrations of MIC, 2 × MIC and 4 × MIC, and (403.67 ± 86.56) in the PBS treatment group, respectively (F = 12.27, P < 0.05), with the highest intracellular ROS level measured following treatment with Mt6-21DLeu at a concentration of 4 × MIC (P < 0.05). Survival curve analysis revealed that Mt6-21DLeu posed no impact on C. elegans survival at concentrations of MIC (χ2 = 0.02, P > 0.05), 2 × MIC (χ2 = 0.06, P > 0.05) or 4 × MIC (χ2 = 0.16, P > 0.05), and there was a significant difference in the survival period of C. elegans among the control group, the infection group, and the treatment group (χ2 = 82.66, P < 0.05), with a significantly longer survival period in the treatment group than in the infection group (χ2 = 45.00, P < 0.05). In addition, the log-transformed bacterial colony counts in C. elegans were (0.00 ± 0.00), (5.46 ± 0.03), and (3.91 ± 0.47) CFU/mL in the control group, the infection group, and the treatment group, respectively (F = 324.80, P < 0.001), and the log-transformed bacterial colony counts in C. elegans were significantly lower in the treatment group than in the infection group (P < 0.05). Conclusions Mt6-21DLeu exerts potent antibacterial effects through disrupting the cell membrane integrity of AB and promoting intracellular ROS accumulation in AB, and exhibits promising potential for treatment of AB infections both in vivo and in vitro, which may serve as a candidate drug molecule against multidrug-resistant AB infections.
9.Safety of teriflunomide in Chinese adult patients with relapsing multiple sclerosis: A phase IV, 24-week multicenter study.
Chao QUAN ; Hongyu ZHOU ; Huan YANG ; Zheng JIAO ; Meini ZHANG ; Baorong ZHANG ; Guojun TAN ; Bitao BU ; Tao JIN ; Chunyang LI ; Qun XUE ; Huiqing DONG ; Fudong SHI ; Xinyue QIN ; Xinghu ZHANG ; Feng GAO ; Hua ZHANG ; Jiawei WANG ; Xueqiang HU ; Yueting CHEN ; Jue LIU ; Wei QIU
Chinese Medical Journal 2025;138(4):452-458
BACKGROUND:
Disease-modifying therapies have been approved for the treatment of relapsing multiple sclerosis (RMS). The present study aims to examine the safety of teriflunomide in Chinese patients with RMS.
METHODS:
This non-randomized, multi-center, 24-week, prospective study enrolled RMS patients with variant (c.421C>A) or wild type ABCG2 who received once-daily oral teriflunomide 14 mg. The primary endpoint was the relationship between ABCG2 polymorphisms and teriflunomide exposure over 24 weeks. Safety was assessed over the 24-week treatment with teriflunomide.
RESULTS:
Eighty-two patients were assigned to variant ( n = 42) and wild type groups ( n = 40), respectively. Geometric mean and geometric standard deviation (SD) of pre-dose concentration (variant, 54.9 [38.0] μg/mL; wild type, 49.1 [32.0] μg/mL) and area under plasma concentration-time curve over a dosing interval (AUC tau ) (variant, 1731.3 [769.0] μg∙h/mL; wild type, 1564.5 [1053.0] μg∙h/mL) values at steady state were approximately similar between the two groups. Safety profile was similar and well tolerated across variant and wild type groups in terms of rates of treatment emergent adverse events (TEAE), treatment-related TEAE, grade ≥3 TEAE, and serious adverse events (AEs). No new specific safety concerns or deaths were reported in the study.
CONCLUSION:
ABCG2 polymorphisms did not affect the steady-state exposure of teriflunomide, suggesting a similar efficacy and safety profile between variant and wild type RMS patients.
REGISTRATION
NCT04410965, https://clinicaltrials.gov .
Humans
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Crotonates/adverse effects*
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Toluidines/adverse effects*
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Nitriles
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Hydroxybutyrates
;
Female
;
Male
;
Adult
;
ATP Binding Cassette Transporter, Subfamily G, Member 2/genetics*
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Middle Aged
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Multiple Sclerosis, Relapsing-Remitting/genetics*
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Prospective Studies
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Young Adult
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Neoplasm Proteins/genetics*
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East Asian People
10.The regulation and mechanism of apolipoprotein A5 on myocardial lipid deposition.
Xiao-Jie YANG ; Jiang LI ; Jing-Yuan CHEN ; Teng-Teng ZHU ; Yu-Si CHEN ; Hai-Hua QIU ; Wen-Jie CHEN ; Xiao-Qin LUO ; Jun LUO
Acta Physiologica Sinica 2025;77(1):35-46
The current study aimed to clarify the roles of apolipoprotein A5 (ApoA5) and milk fat globule-epidermal growth factor 8 (Mfge8) in regulating myocardial lipid deposition and the regulatory relationship between them. The serum levels of ApoA5 and Mfge8 in obese and healthy people were compared, and the obesity mouse model induced by the high-fat diet (HFD) was established. In addition, primary cardiomyocytes were purified and identified from the hearts of suckling mice. The 0.8 mmol/L sodium palmitate treatment was used to establish the lipid deposition cardiomyocyte model in vitro. ApoA5-overexpressing adenovirus was used to observe its effects on cardiac function and lipids. The expressions of the fatty acid uptake-related molecules and Mfge8 on transcription or translation levels were detected. Co-immunoprecipitation was used to verify the interaction between ApoA5 and Mfge8 proteins. Immunofluorescence was used to observe the co-localization of Mfge8 protein with ApoA5 or lysosome-associated membrane protein 2 (LAMP2). Recombinant rMfge8 was added to cardiomyocytes to investigate the regulatory mechanism of ApoA5 on Mfge8. The results showed that participants in the simple obesity group had a significant decrease in serum ApoA5 levels (P < 0.05) and a significant increase in Mfge8 levels (P < 0.05) in comparison with the healthy control group. The adenovirus treatment successfully overexpressed ApoA5 in HFD-fed obese mice and palmitic acid-induced lipid deposition cardiomyocytes, respectively. ApoA5 reduced the weight of HFD-fed obese mice (P < 0.05), shortened left ventricular isovolumic relaxation time (IVRT), increased left ventricular ejection fraction (LVEF), and significantly reduced plasma levels of triglycerides (TG) and cholesterol (CHOL) (P < 0.05). In myocardial tissue and cardiomyocytes, the overexpression of ApoA5 significantly reduced the deposition of TG (P < 0.05), transcription of fatty acid translocase (FAT/CD36) (P < 0.05), fatty acid-binding protein (FABP) (P < 0.05), and fatty acid transport protein (FATP) (P < 0.05), and protein expression of Mfge8 (P < 0.05), while the transcription levels of Mfge8 were not significantly altered (P > 0.05). In vitro, the Mfge8 protein was captured using ApoA5 as bait protein, indicating a direct interaction between them. Overexpression of ApoA5 led to an increase in co-localization of Mfge8 with ApoA5 or LAMP2 in cardiomyocytes under lipid deposition status. On this basis, exogenous added recombinant rMfge8 counteracted the improvement of lipid deposition in cardiomyocytes by ApoA5. The above results indicate that the overexpression of ApoA5 can reduce fatty acid uptake in myocardial cells under lipid deposition status by regulating the content and cellular localization of Mfge8 protein, thereby significantly reducing myocardial lipid deposition and improving cardiac diastolic and systolic function.
Animals
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Humans
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Mice
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Myocytes, Cardiac/metabolism*
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Obesity/physiopathology*
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Male
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Apolipoprotein A-V/blood*
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Lipid Metabolism/physiology*
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Milk Proteins/blood*
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Myocardium/metabolism*
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Diet, High-Fat
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Antigens, Surface/physiology*
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Mice, Inbred C57BL
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Cells, Cultured
;
Female

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