Hypoxic Preconditioning Effects on the Expression of Intracellular Heat Shock Protein (HSP) 27, HSP 70 and HSP 90 in Cultured Adipocyte-Derived Mesenchymal Stem Cell (AMSCs)
Author : A. F. Ghaznawie, I.G. Rurus Suryawan, Andrianto
Upload Date : 19-04-2018
Background: Mesenchymal stem cells (MSC) transplantation has been limited by difficulties in maintaining stem cells survival in a pro-apoptotic microenvironment as in myocardial infarction. Hypoxic preconditioning (HPC) is a strategy to optimize cell survival potency by inducing intracellular upregulation of Heat Shock Proteins (HSP), which have central roles in cytoprotection and preventing apoptosis.
Objective: To analyze the expression of intracellular HSP 27, HSP 70 and HSP 90 in AMSCs preconditioned with HPC (1% O2) as compared to normoxia (21% O2) in vitro.
Methods: This study is an in vitro true experimental randomized post-test design study. AMSCs were isolated from adipose tissue and cultured until 4 passages. The characteristics of AMSCs were identified by immunocytochemistry and flowcytometry using CD 90+, CD 105+ and CD 45-. The samples were divided into 2 groups, hypoxia (O2 1%) for 24 hours and normoxia (O2 21%). Immunocytofluoresence techniques were used to evaluate the expression of HSP 27, HSP 70 and HSP 90.
Results: AMSCs identification showed positive expression of CD 90+, CD 105+ and negative expression of CD45-. Our study showed all parameters studied (HSP 27, HSP 70 and HSP 90) demonstrated a significant higher expression in the hypoxia group compared to normoxia group (272,00 ± 92,225 vs 86,19 ± 26,362 p<0.0001; 130,88 ± 45,416 vs 120,75 ± 97,113 p<0.05; 165,75 ± 58,930 vs 96,81 ± 22,578). Furthermore, HSP 27 expressed higher than HSP 70 and HSP 90, presumably because HSP 27 is an ATP independent chaperone, while HSP 70 and HSP 90 are both dependent ATP chaperones.
Conclusion : Hypoxia preconditioning in AMSCs significantly increased the expression of HSP 27, HSP 70 and HSP 90 therefore, it could be expected to increase cell survival potency of the stem cells.
KEYWORDS : Adipocyte-derived Mesenchymal Stem Cells, Heat Shock Proteins, Hypoxic preconditioning