Peripheral blood mononuclear cells: a potential cellular system to understand differential heat shock response across native cattle (Bos indicus), exotic cattle (Bos taurus), and riverine buffaloes (Bubalus bubalis) of India

Abstract

Circulating leukocytes can be used as an effective model to understand the heat stress response of different cattle types and buffaloes. This investigation aimed to determine the temporal profile of HSPs (HSP40, HSP60, HSP70, and HSP90) expression in circulating peripheral blood mononuclear cells (PBMCs) of Murrah buffaloes, Holstein-Friesian (HF), and Sahiwal cows in response to sublethal heat shock at 42 °C. The viability data indicated HF PBMCs to be the most affected to the heat shock, whereas Sahiwal PBMCs were least affected, indicating its better survivability during the heat stress condition. The qRT-PCR expression data showed significant increase in mRNA expression of the analyzed HSPs genes after heat stimuli to the PBMCs under in vitro condition. In each case, the HSPs were most upregulated at 2 h after the heat stress. Among the HSPs, HSP70 was relatively more expressed followed by HSP60 indicating the action of molecular chaperones to stabilize the native conformation of proteins. However, PBMCs from different cattle types and buffaloes showed difference in the extent of transcriptional response. The level of expression of HSPs throughout the time period of heat stress was highest in buffaloes, followed by HF and Sahiwal cows. The higher abundance of HSP70 mRNA at each time point after heat stress showed prolonged effect of heat stress in HF PBMCs. The data presented here provided initial evidence of transcriptional differences in PBMCs of different cattle types and buffaloes and warrant further research.

Fig. 1

Comparative temporal changes in cellular viability of PBMCs across I Murrah buffaloes, II Sahiwal cows, and III HF cows during in vitro heat stress treatment. Abbreviations: CTR control, TRT heat treated/stressed

Fig. 2

Assesment of relative mRNA expression of individual heat shock protein (HSP) genes in heat stressed (TRT) and unstressed (CTR) PBMCs of Murrah buffaloes, Sahiwal cows, and HF cows. I HSP40, II HSP60, III HSP70, and IV HSP90. For all graphs, y-axis represent relative mRNA expression and x-axis represent the time points. Significant differences (p ≤ 0.05); *p < 0.05 and **p < 0.01. CTR control, TRT heat treated/stressed, Bb B. bubalis, Bi B. indicus, Bt B. taurus, h hour

Fig. 3

Overall mRNA abundance of different heat shock protein (HSP) genes in heat stressed (TRT) and unstressed (CTR) PBMCs across Murrah buffaloes, Sahiwal cows, and HF cows. I HSP40, II HSP60, III HSP70, and IV HSP90. For all graphs, y-axis represent relative mRNA expression and x-axis represent the time points. Values with different letters are significantly different (p ≤ 0.05); HF Holstein–Friesian, h hour

Fig. 4

Comparative expression pattern of heat shock protein (HSP) genes in heat stressed (TRT) and unstressed (CTR) PBMCs of I Murrah buffaloes, II Sahiwal, and III HF cows. Abbreviations: CTR control, TRT heat treated/stressed, h hour. Values with different letters are significantly different (p ≤ 0.05)