Background:Hyperglycemia is a typical symptom of diabetes.High glucose induces apoptosis of isletβcells.While autophagy functions in cytoprotection and autophagic cell death.The interaction between autophagy and apop...Background:Hyperglycemia is a typical symptom of diabetes.High glucose induces apoptosis of isletβcells.While autophagy functions in cytoprotection and autophagic cell death.The interaction between autophagy and apoptosis is important in the modulation of the function of isletβcells.Vitamin B3 can induce autophagy and inhibit isletβapoptosis.Method:The mechanism of vitamin B3-mediated protective effect on the function of isletβcells was explored by the method of western blot,immunofluorescence and flow cytometry.Results:In the present study,high glucose stress increased the apoptosis rate,while vitamin B3 reduced the apoptosis rate.The effect of vitamin B3 on autophagy flux under normal and high glucose stress was also investigated.Vitamin B3 increased the number of autophagosomes and increased the light chain(LC)3-II/LC3-I ratio.In contrast,vitamin B3 decreased sequestosome 1(SQSTM1)/p62 protein expression and inhibited the phosphorylation of mammalian ribosomal protein S6 kinaseβ-1(p70S6K/S6K1),which was a substrate of mammalian target of rapamycin(mTOR)under normal and high glucose stress.To further verify the protective effect of vitamin B3 on apoptosis,we treated isletβcell RIN-m5F with autophagy inhibitor 3-methyladenine(3-MA).Vitamin B3 decreased the apoptosis rate under high glucose stress,while the inhibition of apoptosis by vitamin B3 was blocked after adding 3-MA.Conclusion:Our data suggested that vitamin B3 reduced the apoptosis rate ofβcells,possibly through inducing autophagy under high glucose stress.展开更多
Dioxins are among the common persistent organic pollutants in crabs.To clarify the potential risk of dioxins pollution in Chinese mitten crab,eight types of samples were collected in the South Dongting Lake area for t...Dioxins are among the common persistent organic pollutants in crabs.To clarify the potential risk of dioxins pollution in Chinese mitten crab,eight types of samples were collected in the South Dongting Lake area for the analysis of 17 PCDD/Fs and 12 dl-PCBs.The results indicate that the concentration ofΣPCDD/Fs andΣdl-PCBs in crabs was between 0.993–10.8 and 35.0–282 pg/g w.w.,respectively.The mean WHO-TEQ value ofΣPCDD/Fs in crabs was 0.248±0.205 pg TEQ/g w.w.,and the mean WHO-TEQ value ofΣPCDD/Fs+dl-PCBs in crabs was 0.359±0.280 pg TEQ/g w.w.The total toxic equivalent of bottom sediment,surrounding soil,crab brown meat and juvenile crab were relatively high,which were 2.88,2.67,1.50 and 1.30 pg TEQ/g w.w.,respectively.In the case of 99th percentile,the WHO-TEQ values ofΣPCDD/Fs andΣPCDD/Fs+dl-PCBs in crab white meat were all within the maximum permitted levels as specified in commission regulation(EU)2023/915.The HQ values of 99th percentile ofΣPCDD/Fs+dl-PCBs were 0.0783,0.00703 and 0.0853 for eating brown meat products,eating white meat products and eating whole crabs,respectively.The coordinate points of the samples are connected to the origin by a straight line in the correspondence analysis map.The angle formed by the straight lines of crab brown meat/crab white meat and juvenile crab was acute angle,as did the feed.The angles between the straight line of bottom sediment/surrounding soil and that of other samples were all obtuse angles.In conclusion,although the dioxins of bottom sediment and surrounding soil are obvious,the dioxins of adult crabs are mainly related to that of the juvenile crabs and feed.At present,the intake of dioxins from Chinese mitten crab by Chinese residents is at a safe level because of low annual consumption.It is recommended that adults limit their weekly crab consumption to 1–4 crabs,or only 23.1–105 g of crab brown meat per week,or solely 435–1242 g of crab white meat per week.展开更多
基金supported by the National-Natural Science Foundation of China(32072334),the General Project of the Education Department of Hunan Province(20C0959)the Changsha Natural Science Foundation(kq2007020).
文摘Background:Hyperglycemia is a typical symptom of diabetes.High glucose induces apoptosis of isletβcells.While autophagy functions in cytoprotection and autophagic cell death.The interaction between autophagy and apoptosis is important in the modulation of the function of isletβcells.Vitamin B3 can induce autophagy and inhibit isletβapoptosis.Method:The mechanism of vitamin B3-mediated protective effect on the function of isletβcells was explored by the method of western blot,immunofluorescence and flow cytometry.Results:In the present study,high glucose stress increased the apoptosis rate,while vitamin B3 reduced the apoptosis rate.The effect of vitamin B3 on autophagy flux under normal and high glucose stress was also investigated.Vitamin B3 increased the number of autophagosomes and increased the light chain(LC)3-II/LC3-I ratio.In contrast,vitamin B3 decreased sequestosome 1(SQSTM1)/p62 protein expression and inhibited the phosphorylation of mammalian ribosomal protein S6 kinaseβ-1(p70S6K/S6K1),which was a substrate of mammalian target of rapamycin(mTOR)under normal and high glucose stress.To further verify the protective effect of vitamin B3 on apoptosis,we treated isletβcell RIN-m5F with autophagy inhibitor 3-methyladenine(3-MA).Vitamin B3 decreased the apoptosis rate under high glucose stress,while the inhibition of apoptosis by vitamin B3 was blocked after adding 3-MA.Conclusion:Our data suggested that vitamin B3 reduced the apoptosis rate ofβcells,possibly through inducing autophagy under high glucose stress.
基金supported by the Key Research and Development Program of Hunan Province(2024JK2159)the Risk Assessment of Typical Persistent Organic Pollutants in Aquatic Products(14195211)+1 种基金the Hunan Provincial Natural Science Foundation of China(2024JJ5226)the Innovation Project of Hunan Academy of Agricultural Sciences(2023CX74).
文摘Dioxins are among the common persistent organic pollutants in crabs.To clarify the potential risk of dioxins pollution in Chinese mitten crab,eight types of samples were collected in the South Dongting Lake area for the analysis of 17 PCDD/Fs and 12 dl-PCBs.The results indicate that the concentration ofΣPCDD/Fs andΣdl-PCBs in crabs was between 0.993–10.8 and 35.0–282 pg/g w.w.,respectively.The mean WHO-TEQ value ofΣPCDD/Fs in crabs was 0.248±0.205 pg TEQ/g w.w.,and the mean WHO-TEQ value ofΣPCDD/Fs+dl-PCBs in crabs was 0.359±0.280 pg TEQ/g w.w.The total toxic equivalent of bottom sediment,surrounding soil,crab brown meat and juvenile crab were relatively high,which were 2.88,2.67,1.50 and 1.30 pg TEQ/g w.w.,respectively.In the case of 99th percentile,the WHO-TEQ values ofΣPCDD/Fs andΣPCDD/Fs+dl-PCBs in crab white meat were all within the maximum permitted levels as specified in commission regulation(EU)2023/915.The HQ values of 99th percentile ofΣPCDD/Fs+dl-PCBs were 0.0783,0.00703 and 0.0853 for eating brown meat products,eating white meat products and eating whole crabs,respectively.The coordinate points of the samples are connected to the origin by a straight line in the correspondence analysis map.The angle formed by the straight lines of crab brown meat/crab white meat and juvenile crab was acute angle,as did the feed.The angles between the straight line of bottom sediment/surrounding soil and that of other samples were all obtuse angles.In conclusion,although the dioxins of bottom sediment and surrounding soil are obvious,the dioxins of adult crabs are mainly related to that of the juvenile crabs and feed.At present,the intake of dioxins from Chinese mitten crab by Chinese residents is at a safe level because of low annual consumption.It is recommended that adults limit their weekly crab consumption to 1–4 crabs,or only 23.1–105 g of crab brown meat per week,or solely 435–1242 g of crab white meat per week.
