Study on the mechanism of long non-coding RNA AI662270 regulating insulin resistance in adipocytes in aging mice
10.11855/j.issn.0577-7402.0251.2025.0319
- VernacularTitle:长链非编码RNA AI662270调控衰老小鼠脂肪细胞胰岛素抵抗的机制研究
- Author:
Yi-Fan ZHANG
1
;
Ya-Qi HU
;
Rui WANG
;
Shu-Wen WANG
;
Cheng-Fu YUAN
Author Information
1. 国家中医药管理局中药药理(肿瘤)科研三级实验室,湖北宜昌 443002;三峡大学基础医学院,湖北宜昌 443002;海安市人民医院病理科,江苏南通 226600
- Keywords:
aging;
epididymal white adipose tissue;
insulin resistance;
long non-coding RNA AI662270
- From:
Medical Journal of Chinese People's Liberation Army
2025;50(8):999-1007
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the mechanism by which long non-coding RNA(lncRNA)AI662270 regulates insulin resistance in adipocytes in aging mice.Methods(1)Twenty male C57BL/6 mice were randomly divided into youth(4-month-old)group and aged(18-month-old)group(n=10).Mice in youth group were raised to 4 months of age and euthanized by orbital exsanguination under urethane anesthesia,while aged mice were euthanized at 18 months using the same sacrifice method.Epididymal white adipose tissue(eWAT)and liver tissue were rapidly dissected.Western blotting was employed to detect the protein expression levels of tumor suppressor gene 1(p16ink4a)and cyclin-dependent kinase inhibitor p21(p21kip1),RT-qPCR was used to measure the expression of 4 differentially expressed lncRNAs(C4a,AI662270,BATE1 and Gm29719).Mouse embryonic fibroblasts(3T3-L1)were cultured and divided into a normal control group(no treatment after induced differentiation into mature adipocytes)and a senescence model group[doxorubicin(ADR)-treated group;0.2 μmol/L ADR was used to induce senescent adipocytes].β-galactosidase staining was performed to assess adipocyte senescence.RT-qPCR was applied to evaluate the expression of AI662270 and senescence markers(p16ink4a,p21kip1,p53),while Western blotting was utilized to detect the expression levels of phosphorylated H2A histone family member X(γ-H2AX),p16ink4a,and p21kip1 proteins.(2)Hexokinase method was adopted to measure glucose content in mouse serum and 3T3-L1 adipocyte culture medium.RT-qPCR was performed to analyze mRNA expression levels of insulin sensitivity-related gene protein kinase B(Akt),insulin receptor substrate 1(IRS1),phosphatidylinositol 3 kinase(PI3K)and glucose transporter 4(GLUT4)in mouse eWAT and adipocytes.Western blotting was conducted to determine the protein expression levels of IRS 1,PI3K,Akt,and p-Akt.(3)Spearman correlation analysis was applied to examine the correlation between AI662270 expression levels and IRS1/PI3K mRNA expression levels.A low-expression model of AI662270 in senescent adipocytes was constructed,and RT-qPCR was used to verify the knockdown efficiency.Hexokinase method was employed to assess glucose content in the cell culture medium of senescent adipocytes after AI662270 knockdown.RT-qPCR was performed to measure the mRNA expressions of Akt,IRS1,IRS2,and PI3K,while Western blotting was utilized to detect the expressions levels of Akt and p-Akt proteins.(4)Bioinformatics analysis was performed to predict downstream target genes of AI662270 and their binding sites.RT-qPCR and Western blotting were subsequently applied to validate the expression of these downstream target genes following AI662270 knockdown.Results(1)Compared with youth group,the protein expression levels of p16ink4a and p21kip1 in eWAT of aged mice were significantly increased(P＜0.05).Additionally,the expression levels of C4a,AI662270,BATE1,and Gm29719 in both eWAT and liver tissues were significantly increased in aged group(P＜0.05).β-galactosidase staining revealed enhanced blue-green coloration and enlarged,flattened cellular morphology in ADR-treated senescent adipocytes compared with normal control group.Compared with normal control group,ADR-treated senescent adipocytes significantly increased the mRNA expression levels of AI662270,p16ink4a,and p21kip1,and significantly elevated protein expression levels of γ-H2AX,p16ink4a,and p21kip1(P＜0.05).(2)Serum glucose content was significantly higher in aged group mice compared with youth group(P＜0.01),and glucose content in the adipocyte culture medium in ADR group was significantly increased(P＜0.05).The expression levels of IRS1 and PI3K in eWAT in aged group were significantly reduced compared with youth group(P＜0.01).Compared with normal control group,the expression levels of IRS 1 and PI3K in adipocytes in ADR-treated group were also significantly reduced(P＜0.05).(3)Spearman correlation analysis demonstrated that the expression level of AI662270 was negatively correlated with the mRNA expression levels of IRS1 and PI3K(P＜0.05).RT-qPCR showed that AI662270 expression level was significantly reduced in the siAI662270-transfected senescent adipocytes compared with siNC group(P＜0.05),indicating the low expression model of aged adipocytes AI662270 was successfully constructed.Hexokinase assay results showed that glucose content in the cell culture medium was significantly reduced after the AI662270 was knocked down by senescent adipocytes(P＜0.05).Furthermore,the mRNA expression levels of IRS1,IRS2 and PI3K(P＜0.05)and the p-Akt/Akt ratio in senescent adipocytes was significantly increased after knockdown of AI662270(P＜0.01).(4)Bioinformatics analysis predicted miR-3073b-3p as a downstream target gene of AI662270,and heme oxygenase 1(Hmox1)was identified as a target molecule of miR-3073b-3p.The expression level of miR-3073b-3p in senescent adipocytes in siAI662270 group was significantly increased,while the mRNA and protein expression level of Hmox1 were significantly decreased compared with siNC group(P＜0.01).Conclusions Aging significantly increases the expression of AI662270 in eWAT of mice,and the expression of AI662270 was negatively correlated with insulin sensitivity.AI662270 knockdown can reduce glucose content in senescent adipocyte culture medium,upregulate the expression of IRS1 and PI3K,and increase insulin sensitivity in senescent adipocytes,which may be mediated through the AI662270/miR-3073b-3p/Hmox1 pathway.
