Resumen de Heat stress induced in vitro affects cell viability and gene expression of dermal fibroblasts from bovine and buffalo

Natasha P. Borges, Eduardo B. Souza, Simone S. D. Santos, Otávio M. Ohashi, Priscila P. B. Santana, Ednaldo Silva-Filho

• Aim of study: To evaluate the response of dermal fibroblasts to heat stress and different time exposures on the cell survival and gene expression.

  Area of study: Belém city, Pará state. Brazil.

  Material and methods: Fibroblasts were isolated from ear skin of bovine (n= 4) and buffalo (n= 4), cultured in vitro until the 3rd passage and submitted to heat stress at 42°C for 3, 6 and 12 h, except for the negative control (38.5°C for 24 h). Cell survival was measured using Trypan blue, and RNA isolation was performed using Trizol method following qRT-PCR to quantify the relative expression of the inducible heat shock protein HSPA1A, the pro-apoptotic BAX and pro-inflammatory IFN-γ genes.

  Main results: Heat stress induced in vitro affected the cell viability and gene expression in a time-dependent manner. Gene expression was relatively lower in buffalo (p<0.05) than in bovine. Until 3 h of heat stress, HSPA1A showed a slight increase in both bovine and buffaloes, and BAX was 5.82-fold greater in bovine (p<0.05). After 6 h, HSPA1A was 75.81-fold (p<0.0001) and INF-γ was 20.15-fold greater (p<0.05) in bovine than buffalo. Only after 6 h the cell viability started to decrease significantly (p<0.05) in both species.

  Research highlights: Dermal fibroblasts of buffaloes and bovine were sensitive to heat stress induced in vitro, which was most detrimental to cell survival after 6 h. The expression of HSPA1A, BAX and INF-γ genes in response to heat stress indicate a slight sensibility of the dermal fibroblasts of bovine compared to their buffalo counterpart.