Effect of Metformin and Simvastatin in Inhibiting Proadipogenic Transcription Factors.

Jelena Jakab,Nikola Volarić,Ivan Tušek,Vesna Ćosić,Milorad Zjalić,Aleksandar Včev,Blaženka Miškić,Dario Nakić,Štefica Mikšić

doi:10.3390/cimb43030144

Abstract

Obesity is a multifactorial chronic disease characterized by the excessive accumulation of fat in adipose tissue driven by hypertrophy and hyperplasia of adipocytes through adipogenesis. Adipogenesis plays a key role in the development of obesity and related metabolic disorders, which makes it potential target for the therapeutic approach to obesity. An increasing number of studies confirm the pleiotropic action of the combined treatment with metformin and statins, suggesting their anti-hypertensive, anti-inflammatory, and anti-adipogenic effect. The aim of this study was to analyze the effect of different doses of metformin (MET) and simvastatin (SIM) on the expression of key transcription factors of adipogenesis. Mouse 3T3-L1 preadipocytes were induced to differentiation in adipogenic medium with sustained MET and SIM treatment to assess the effect on adipogenesis. Nine days after initiating adipogenesis, the cells were prepared for further experiments, including Oil Red O staining, RT-PCR, Western blotting, and immunocytochemistry. Treating the cells with the combination of MET and SIM slightly reduced the intensity of Oil Red O staining compared with the control group, and down-regulated mRNA and protein expression of PPARγ, C/EBPα, and SREBP-1C. In conclusion, the inhibitory effect of MET and SIM on adipocyte differentiation, as indicated by decreased lipid accumulation, appears to be mediated through the down-regulation of adipogenic transcription factors, peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer binding pro-tein α (C/EBPα), and sterol regulatory element-binding protein 1 (SREBP-1C).

Highlights

MTT assay results showed that neither metformin nor simvastatin produced a toxic effect in all three concentrations, even when used as a combined treatment (Figure 1)
We examined whether MET and SIM affected the mRNA levels of adipogenic transcription factors peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer binding pro-tein α (C/EBPα), and SREBP-1C during adipocyte differentiation
2 μM, H = cells treated with the combination of metformin 200 μM and simvastatin 100 nM, I = cells treated with the combination of metformin 2 mM and simvastatin 1 μM, J = cells treated with the combination of metformin 4 mM and simvastatin 2 μM, PPARγ = peroxisome proliferator-activated receptor γ, C/EBPα = CCAAT/enhancer binding protein α, SREBP-1C = sterol regulatory elementbinding protein 1, GAPDH = Glyceraldehyde 3-phosphate dehydrogenase

Summary

Introduction

Obesity is a multifactorial chronic disease characterized by the excessive accumulation of fat in adipose tissue and chronic inflammation with no visible infection or known autoimmune process [1]. It is a risk factor for the development of metabolic syndrome, cardiovascular disease (CVD), type 2 diabetes mellitus (T2DM), hypertension, dyslipidemia, and malignancies [2]. Adipose tissue is the main regulator of energy balance and glucose homeostasis in a healthy body [3]. Excessive expansion of white adipose tissue (WAT)

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