The effect of metformin on the metabolism of human vascular smooth muscle cells in high glucose conditions.

OBJECTIVES: Metformin is widely used in type 2 diabetic patients as an antihyperglycemic drug. The aim of this study was to investigate the effect of metformin on the metabolism of vascular smooth muscle cells in high glucose conditions. MATERIALS AND METHODS: The vascular smooth muscle cells were cultured in DMEM F12 containing glucose as high as 25 mM. The preconditioned cells were then treated with metformin in doses of 1, 5, and 7 mM for 24 h. MTT method was used to determine cell viability. Biochemical parameters including lactate, glucose, total protein, creatinine, and triglyceride were measured in the cell culture after the treatment with metformin. Oil Red O staining method was used to stain the lipids in the cells. RESULTS: Metformin reduced significantly (p<0.001) VSMC proliferation in a concentration-dependent manner. With the increase of glucose uptake by VSMCs, the cell lipid deposition was not changed. Other biochemical parameters such as lactate, triglyceride, total protein, and creatinine were significantly changed in the cell culture (p<0.05). CONCLUSIONS: Metformin increased the glucose uptake impacting metabolic pathways in VSMCs. It also increased the lactate efflux and protein metabolism without the change in cellular lipid deposition in high glucose conditions.

Non-coding RNAs are correlated to TGF-ß receptor type 2 in patients with colorectal cancer.

BACKGROUND: Multiple molecular expression alterations, particularly in non-coding RNAs, play fundamental roles in the regulations of cellular processes and may relate to the occurrence and progression of colorectal cancer (CRC). In the present study, we investigated the associations between TGFBR2, miR20a-5p and long non-coding RNA (lncRNA) LAMTOR5-AS1 in CRC patients. METHODS: Colorectal cancer and adjacent normal tissue samples (n = 34) were prepared from CRC patients. The associations between TGFBR2, miR20a-5p and lncRNA LAMTOR5-AS1 were predicted using bioinformatics tools. The expression levels of TGFBR2, miR20a-5p and lncRNA LAMTOR5-AS1 were measured using a quantitative real-time polymerase chain reaction technique. The TGFBR2 protein values were measured by western blotting. The clinical importance of lncRNA LAMTOR5-AS1 was assessed using receiver operating characteristic curve. RESULTS: The up-regulated levels of TGFBR2 (p = 0.02), TGFBR2 protein (p = 0.008) and lncRNA LAMTOR5-AS1 (p = 0.02) were significantly observed in CRC tissues compared to the adjacent normal tissues. The miR20a-5p expression level (p = 0.009) was downregulated in CRC tissues. In addition, the miR20a-5p expression level was inversely correlated to the TGFBR2 gene (r2  = 0.88, p < 0.0001), protein (r2  = 0.95, p < 0.0001) and lncRNA LAMTOR5-AS1 gene (r2  = 0.93, p < 0.0001) expression levels. Based on the area under curve, the increase of lncRNA LAMTOR5-AS1 expression level with a sensitivity of 64.52% and specificity of 65.52% was considered in CRC patients. CONCLUSIONS: We propose that miR20a-5p is inversely related to long non-coding RNA (lncRNA) LAMTOR5-AS, such that it may be involved in the regulation of TGFBR2 expression level in CRC patients.

Dexamethasone suppresses the proliferation and migration of VSMCs by FAK in high glucose conditions.

BACKGROUND: High glucose conditions cause some changes in the vessels of diabetes through the signal transduction pathways. Dexamethasone and other corticosteroids have a wide range of biological effects in immunological events. In the present study, the effects of dexamethasone were investigated on the VSMC (vascular smooth muscle cell) proliferation, and migration based on the FAK gene and protein changes in high glucose conditions. METHODS AND MATERIALS: The vascular smooth muscle cells were cultured in DMEM and were treated with dexamethasone (10-7 M, 10-6 M, and 10-5 M) for 24, and 48 h in high glucose conditions. The cell viability was estimated by MTT method. The FAK gene expression levels and pFAK protein values were determined by RT-qPCR and western blotting techniques, respectively. A scratch assay was used to evaluate cellular migration. RESULTS: The FAK gene expression levels decreased significantly dependent on dexamethasone doses at 24 and 48 h. The pFAK protein values decreased significantly with a time lag at 24- and 48-h periods as compared with gene expression levels. CONCLUSION: The results showed that the inhibition of VSMC proliferation and migration by dexamethasone in the high glucose conditions may be related to the changes of FAK.

Focal adhesion kinase-related pathways may be suppressed by metformin in vascular smooth muscle cells in high glucose conditions.

INTRODUCTION: Cardiovascular diseases are known as one of the important causes of death in patients with diabetes mellitus. Metformin is used as an oral medication for reducing blood sugar. In this study, the effects of metformin were investigated on the FAK gene expression levels, pFAK protein values, cell viability and migration rate of VSMCs in high glucose conditions. MATERIALS AND METHODS: The FAK gene expression levels and pFAK protein values were evaluated in VSMCs treated with different doses of metformin (1, 5 and 7 mM), based on cell viability using RT-qPCR, western blotting and MTT techniques. The cellular migration was evaluated by scratch assay. RESULTS: The FAK gene expression levels reduced significantly in metformin-treated VSMCs at 24 h and 48 h periods (p < .0008 and p < .0001, respectively). The pFAK protein values reduced significantly at 24 h (5 mM and 7 mM metformin doses) and 48 h periods (p < .001). In agreement with pFAK protein values, cellular migration reduced significantly at 24 h and 48 h periods (p < .001). CONCLUSION: The results showed that metformin may suppress the proliferation and migration of VSMCs via FAK-related pathways and may retard the progression of vessel stenosis in diabetes.