Survival Improvement of Human Adipocyte Mesenchymal Stem Cell by Hypoxic Preconditioning

Tóm tắt

Background: Contributing factors for improved survival of human adipocytes mesenchymal stem cells (h-AMSCs) cultured through hypoxia preconditioning, in example apoptosis inhibition involving BCL2 and HSP27 expression, trigger signal expression (VEGF), SCF expression, OCT-4 expression, and CD44+ expression. Objective: to explain the mechanism and role of hypoxic preconditioning and the optimal duration of hypoxic preconditioning exposure to improve survival of h-AMSCs so that could it could be used as a benchmark for h-AMSCs culture strategy before transplantation.

Methods: This study was an experimental laboratory explorative study (in vitro study) with hypoxic preconditioning in human-adipose mesenchymal stem cells (h-AMSCs) cultures. This research was conducted through 4 stages. First,  Isolation and h-AMSCs culture from adipose tissue of patient (human). Second is the characterization of h-AMSCs from adipose tissue by phenotype (Flowcytometry) through CD44+, CD90+ and CD45-expression before being pre-conditioned for hypoxic treatment. Third, the hypoxic preconditioning in h-AMSCs culture (in vitro) was performed with an oxygen concentration of 1% for 24, 48 and 72 hours. Fourth, observation of survival from h-AMSCs culture was tested on the role of CD44 +, VEGF, SCF, OCT-4, BCL2, HSP27 with Flowcytometry method and apoptotic inhibition by Tunnel Assay method.

Results: The result of regression test showed that time difference had an effect on VEGF expression (p=0,000;β=-0,482) and hypoxia condition also influenced VEGF expression (p= 0,000; β=0,774). The result of path analysis showed that SCF had an effect on OCT-4 expression (p=0,000; β=0,985). The regression test results showed that time effects on HSP27 expression (p=0.000; β=0.398) and hypoxia precondition also affects HSP27 expression (p=0.000; β=0.847). Pathway analysis showed that BCL2 expression inhibited apoptosis (p=0.030; β=-0.442) and HSP27 expression also inhibited apoptosis (p=0,000; β=-0.487).

Conclusion: In conclusion, hypoxic preconditioning of h-AMSC culture has proven to increase the expression of VEGF, SCF, OCT-4, and BCL2 and HSP27. This study demonstrated and explained the existence of a new mechanism of increased h-AMSC survival in cultures with hypoxic preconditioning (O2 1%) via VEGF, SCF, OCT-4, BCL2, and HSP 27. But CD 44+ did not play a role in the mechanism of survival improvement of human AMSC survival.