Hypoxic Preconditioning Prevents Oxidative Stress-Induced Cell Death in Human Hair Follicle Stem Cells

Abstract

Objectives: This study investigated the impact of hypoxic preconditioning on the survival and oxidative stress tolerance of nestin-expressing hair follicle stem cells (hHFSCs) and SH-SY5Y neuroblastoma cells, two crucial cell types for central nervous system therapies. The study also examined the relative expression of three key genes, HIF1α, BDNF, and VEGF following hypoxic preconditioning.

Materials and methods: hHFSCs were isolated from human hair follicles, characterized, and subjected to hypoxia for up to 72 hours. SH-SY5Y cells were similarly preconditioned for up to 72 hours. Cell viability under hypoxic conditions and oxidative stress was assessed. The relative expression of key genes was evaluated using qRT-PCR.

Results: hHFSCs exhibited remarkable resilience to hypoxic conditions, while SH-SY5Y cells displayed lower tolerance. Hypoxic preconditioning improved the viability of both cell types under oxidative stress. HIF1α mRNA was significantly downregulated, and VEGF transcripts increased after preconditioning, suggesting adaptations to prolonged hypoxia.

Conclusion: Hypoxic preconditioning enhances the survival and oxidative stress resilience of hHFSCs and SH-SY5Y cells, offering potential benefits for central nervous system cell therapy. The differential responses observed emphasize the need for tailored preconditioning strategies for specific cell types. These findings underscore the importance of hypoxic preconditioning and warrant further research into the underlying mechanisms, bringing us closer to effective neurological disorder treatments.

Keywords: EPI-NCSCs; HAP stem cells; Hypoxia; Priming.

Figure 1

Migration and characterization of human hair follicle stem cells (HFSCs). Using skin punch to obtain human pubic skin A). Migration of stem cells from the hair follicles B and C). Expression of nestin D) and SOX10 (E) by in vitro cultured HFSCs.

Figure 2

Surface marker expression by human hair follicle stem cells (HFSCs). Expression of CD29, CD44, CD73, CD90 but not CD34 and CD45 surface markers by in vitro cultured HFSCs.

Figure 3

Effects of normoxic and hypoxic conditions on the viability of human hair follicle stem cells (HFSCs). Using propidium iodide (PI, red), fluorescein diacetate (FDA, green), and Hoechst 33342 (blue) to stain HFSCs cultured under either normoxic conditions (upper part) or hypoxic conditions (lower part).

Figure 4

Effects of normoxic and hypoxic conditions on the viability of SH-SY5Y neuroblastoma cell line. Using propidium iodide (PI, red), fluorescein diacetate (FDA, green), and Hoechst 33342 (blue) to stain SH-SY5Y neuroblastoma cells cultured under either normoxic conditions (upper part) or hypoxic conditions (lower part).

Figure 5

Effects of normoxic and hypoxic preconditioning on the viability of human hair follicle stem cells (HFSCs) and SH-SH5Y cells exposed to H₂O₂. Viability of normoxic and hypoxic preconditioned HFSCs and SH-SY5Y cells following exposure to varying concentrations of H₂O₂. *P<0.05, **P<0.01 and ***P<0.001.

Figure 6

Expression levels of HIF1α, BDNF, and VEGF in normoxic and hypoxic preconditioned human hair follicle stem cells (HFSCs) and SH-SY5Y cells. Relative expression levels of hypoxia-inducible factor 1-alpha (HIF1α), brain-derived neurotrophic factor (BDNF), and vascular endothelial growth factor (VEGF) in hypoxic preconditioned HFSCs (upper part), and the SH-SY5Y neuroblastoma cell line (lower part) compared to normoxic cultured cells. **P&0.01 and ****P&0.001; ns: non-significant.