[Animal Modeling]-Experimental study of TGF-β pathway regulated by miR-335-5P mediating insulin resistance and pancreatic β cell secretion in gestational diabetic mice

  Objective: To treat gestational diabetes (GDM) mice with miR-335-5P and transforming factor-β (TGF-β). miR-335-5P regulates the TGF-β pathway and promotes pancreatic secretion and clarification, which enhances β-cells and insulin resistance It opens up a new way for the treatment of GDM patients.

  Method: SPFBalb/c mice were raised in 2 male and female cages, 10 normal pregnant mice were used as the blank group, and 48 mice that successfully constructed the GDM model were randomly selected as the GDM group. . Groups A, B, C, D, E, F, each group contains 8 animals. A group (model group), B group (model group + solvent), C group (model group + miR-335-5P mimic), D group (model group + miR-335-5P inhibitor), E group (model )) group +si-TGF-β), group F (model group + miR-335-5P inhibitor + si-TGF-β). After drug treatment, an oral glucose tolerance test (OGTT) was performed to detect fasting blood glucose (FBG) and fasting insulin (FIRI), and the insulin resistance index (IRI) of the steady-state model was calculated. A hyperglycemia clamp test was performed. Estimation of pancreatic β-cell function to determine glucose infusion rate (GIR); using RT-qPCR, Western blot analysis, and ELISA insulin release to determine the key factors of miR-335-5P and TGF-β pathway mRNA content was determined. Pancreatic beta cells.

  Results: D, F group FBG, FIRI, IRI are lower than before administration, lower than C, E group (P\u003c0.05); D, F group GIR, stage 1 insulin, maximum insulin are all before administration. The E and E of miR-335-5P, TGF-β and c-Myc are lower than the C and E groups (P\u003c0.05); miR-335-5P, TGF-β and c-Myc are expressed in D and F groups Both are lower than the A and B groups (P\u003c0.05). When miR-335-5P expression was detected in pancreatic β cells, TGF-β and c-Myc were expressed in varying degrees. TGF-β is expressed in the cytoplasm of pancreatic β cells, and the expression of TGF-β in groups D and F is higher than that in groups C and C. Group E is higher than group A and group B (P\u003c0.05).

   Conclusion: miR-335-5P up-regulates c-Myc expression in GDM mice, further activates TGF-β pathway, increases insulin resistance, and inhibits pancreatic β-cell secretion.