Zinc sulfate contributes to promote telomere length extension via increasing telomerase gene expression, telomerase activity and change in the TERT gene promoter CpG island methylation status of human adipose-derived mesenchymal stem cells

Abstract

The use of mesenchymal stem cells (MSCs) for cell therapy and regenerative medicine has received widespread attention over the past few years, but their application can be complicated by factors such as reduction in proliferation potential, the senescent tendency of the MSCs upon expansion and their age-dependent decline in number and function. It was shown that all the mentioned features were accompanied by a reduction in telomerase activity and telomere shortening. Furthermore, the role of epigenetic changes in aging, especially changes in promoter methylation, was reported. In this study, MSCs were isolated from the adipose tissue with enzymatic digestion. In addition, immunocytochemistry staining and flow cytometric analysis were performed to investigate the cell-surface markers. In addition, alizarin red-S, sudan III, toluidine blue, and cresyl violet staining were performed to evaluate the multi-lineage differentiation of hADSCs. In order to improve the effective application of MSCs, these cells were treated with 1.5 × 10−8 and 2.99 × 10−10 M of ZnSO4 for 48 hours. The length of the absolute telomere, human telomerase reverse transcriptase (hTERT) gene expression, telomerase activity, the investigation of methylation status of the hTERT gene promoter and the percentage of senescent cells were analyzed with quantitative real-time PCR, PCR-ELISA TRAP assay, methylation specific PCR (MSP), and beta-galactosidase (SA-β-gal) staining, respectively. The results showed that the telomere length, the hTERT gene expression, and the telomerase activity had significantly increased. In addition, the percentage of senescent cells had significantly decreased and changes in the methylation status of the CpG islands in the hTERT promoter region under treatment with ZnSO4 were seen. In conclusion, it seems that ZnSO4 as a proper antioxidant could improve the aging-related features due to lengthening of the telomeres, increasing the telomerase gene expression, telomerase activity, decreasing aging, and changing the methylation status of hTERT promoter; it could potentially beneficial for enhancing the application of aged-MSCs.

Deregulation of the imprinted DLK1-DIO3 locus ncRNAs is associated with replicative senescence of human adipose-derived stem cells

“…Culture of hMSCs at lower concentrations (3–5%) of [O 2 ] revealed a significant increase in culture lifespan and better cellular quality, which was associated with a favorable metabolic state of increased glycolysis and decreased oxidative phosphorylation, resulting in reduced levels of oxidative stress [ 3 – 8 ]. In agreement with these observations are the results of several studies using ex vivo treatments with antioxidants (reviewed in [ 9 ]); for example, short-term treatment of hADSCs with physiological concentrations of zinc sulphate promotes telomere length extension. It is important to note while low [O 2 ] is usually referred to as hypoxia, low O 2 tensions are considered normoxic in several organs [ 10 , 11 ].…”

“…The main pathways activated in senescent cells are Rb/p16 and p53/21, leading to progressive cell cycle blockade and cell growth arrest. In line with this, the positive effects on hADSCs by short-term treatment with zinc sulphate are mediated by modulation of the methylation status of the promoter of TERT, the telomerase catalytic subunit [ 9 ]. Many studies consider senescence as a tumor suppressor network mechanism (reviewed in [ 15 ]).…”

The positive effect of chick embryo and nutrient mixture on bone marrow- derived mesenchymal stem cells from aging rats

“…Farahzadi R et al . reported that Zinc sulfate promoted telomere length extension via increasing telomerase gene expression 28 . Furthermore, the dietary antioxidants supported the maintenance of telomere length, particularly vitamin and soybean phospholipid 29 .…”

Gene expression analysis of human adipose tissue-derived stem cells during the initial steps of in vitro osteogenesis

“…Samples were obtained after signed informed consent was provided by the donors or their legal representatives, in accordance with guidelines for research involving human subjects and with the approval of the Ethics Committee of Fundação Oswaldo Cruz, Brazil (approval number 419/07). hASCs were isolated and expanded as previously described elsewhere 51 with modifications. Briefly, 200 ml of adipose tissue were digested with 1 mg/ml collagenase type I (GIBCO) solution for 30 min at 37 °C, 5% CO 2 under constant shaking.…”