ABSTRACT
OBJECTIVE: To identify Cald1 as a novel regulator of Linggui Zhugan decoction for improving insulin resistance in vivo and in vitro. METHODS: Sprague-Dawley rats were randomly assigned to 3 groups that were received a normal rat chow diet, high-fat diet (HFD), and an HFD plus LGZGD, respectively. The homeostatic model assessment (HOMA)-insulin resistance (IR) index was used to determine IR. Gene microarray methodology was used to identify differentially expressed genes (DEGs) in the three groups of rats. The DEGs associated with IR were confirmed by quantitative real-time polymerase chain reaction. Additionally, Mouse 3T3-L1 pre-adipocytes were differentiated into mature 3T3-L1 adipocytes, which were then treated with tumor necrosis factor (TNF)-α to induce cellular IR. Lipid accumulations were identified by Oil Red O staining. Glucose uptake was assessed using the 3 H-2-DG test. RESULTS: In this study, we found Cald1 was further screened to validate its biological function in 3T3-L1 adipocytes induced to develop IR. In vitro experiments showed that insulin-stimulated 3H2-DG uptake by IR 3T3-L1 adipocytes was increased after LGZGD intervention, which was associated with a down-regulation of Cald1 expression. CONCLUSION: LGZGD ameliorates HFD-induced IR in rats and TNF-α induced IR in adipocytes by down-regulating Cald1 expression.
Subject(s)
Insulin Resistance , 3T3-L1 Cells , Adipocytes/metabolism , Animals , Glucose/metabolism , Insulin , Insulin Resistance/genetics , Mice , Rats , Rats, Sprague-DawleyABSTRACT
BACKGROUND: Substantial studies have demonstrated that fasting therapy (FT) can inhibit the inflammatory response and improve insulin resistance (IR); however, the underlying mechanisms are still unclear. This study aimed to explore the related mechanisms of intermittent FT for the treatment of IR. METHODS: A rat IR model was established through collaboration of a high-fat diet with streptozotocin (STZ) injection. 8 rats were treated with intermittent FT. A positive control group was treated with metformin (MET). Mouse 3T3-L1 pre-adipocytes were cultured and induced into adipocytes in vitro, and were used as the cellular IR model. Blood insulin, glucose, and homeostatic model assessment (HOMA)-IR index were determined. Enzyme-linked immunosorbent assay (ELISA) and western blotting were used to detect inflammatory markers. Oil Red O staining determined the lipid accumulation. An NLRP3 inflammasome agonist served to investigate the effects of FT on IR in 3T3-L1 adipocytes. RESULTS: The high levels of blood insulin, glucose, and HOMA-IR induced by high-fat diet and STZ were significantly decreased by FT. The FT also reduced the level of C-reactive protein (CRP), interleukin (IL)-1ß, IL-18, caspase-1, and increased the expression of glucose transporter 1 (GLUT1), insulin receptor substrate 1 (IRS1), and IRS2 in both the rat models and 3T3-L1 adipocytes. In addition, FT significantly relieved lipid accumulation in the liver of rats. Application of NLRP3 inflammasome agonist weakened the effect of FT on IR in the IR 3T3-L1 adipocytes. CONCLUSIONS: These results suggest that FT can ameliorate the high-fat diet-and STZ-induced IR in rats through inhibition of NLRP3 inflammasome.
Subject(s)
Diabetes Mellitus, Experimental , Insulin Resistance , Animals , Diabetes Mellitus, Experimental/drug therapy , Fasting , Inflammasomes , Mice , NLR Family, Pyrin Domain-Containing 3 Protein , RatsABSTRACT
Objective Transdifferentiation exists between stromal cells or between stromal cells and cancer cells. Evodiamine and berberine are predominant pharmacological components of Zuojin pill, a prescription of Traditional Chinese Medicine, playing crucial functions in remolding of tumor microenvironment. This study aimed to explore the effect of combination of evodiamine with berberine (cBerEvo) on the phenotypic transition of colon epithelial cells induced by tumor-associated fibroblasts, as well as the involved mechanisms.Methods Human normal colon epithelial cell line HCoEpiC cells were treated with the prepared conditioned medium of CCD-18Co, a human colon myofibroblast line, to induce epithelial-mesenchymal transition. Phase contrast microscope was used to observe the morphological changes. Epithelial-mesenchymal transition markers including E-cadherin, vimentin and alpha-smooth muscle actin (α-SMA) were observed with immunofluorescence microscopy. Migration was assessed by wound healing assay. Western blotting was used to detect the expressions of E-cadherin, vimentin, α-SMA, Snail, ZEB1 and Smads. Results In contrast to the control, the tumor-associated fibroblasts-like CCD-18Co cells induced down-regulation of E-cadherin and up-regulation of vimentin, α-SMA, Snail and ZEB1 (P<0.05), and promoted migration of HCoEpiCs (P<0.05), with over expression of Smads including Smad2, p-Smad2, Smad3, p-Smad3 and Smad4 (P<0.05), which were abolished by a transforming growth factor-ß (TGF-ß) receptor inhibitor LY364947 and by cBerEvo in a concentration dependent manner. In addition, cBerEvo-inhibited ratios of p-Smad2/Smad2 and p-Smad3/Smad3 were also dose dependent.Conclusion The above results suggest that cBerEvo can regulate the differentiation of colon epithelial cells induced by CCD-18Co through suppressing activity of TGF-ß/Smads signaling pathway.
