Investigation of Metabolome Underlying the Biological Mechanisms of Acute Heat Stressed Granulosa Cells.

Qing Xu,Shanjiang Zhao,Yajing Wang,Abdul Sammad,Saqib Umer,Adnan Khan,Lirong Hu,Zaheer Abbas,Yachun Wang,Hanpeng Luo,Huabin Zhu

doi:10.3390/ijms23042146

Abstract

Heat stress affects granulosa cells and the ovarian follicular microenvironment, ultimately resulting in poor oocyte developmental competence. This study aims to investigate the metabo-lomics response of bovine granulosa cells (bGCs) to in vitro acute heat stress of 43 °C. Heat stress triggers oxidative stress-mediated apoptosis in cultured bGCs. Heat-stressed bGCs exhibited a time-dependent recovery of proliferation potential by 48 h. A total of 119 metabolites were identified through LC–MS/MS-based metabolomics of the spent culture media, out of which, 37 metabolites were determined as differentially involved in metabolic pathways related to bioenergetics support mechanisms and the physical adaptations of bGCs. Multiple analyses of metabolome data identified choline, citric acid, 3-hydroxy-3-methylglutaric acid, glutamine, and glycocyamine as being upregulated, while galactosamine, AICAR, ciliatine, 16-hydroxyhexadecanoic acid, lysine, succinic acid, uridine, xanthine, and uraconic acid were the important downregulated metabolites in acute heat stress. These differential metabolites were implicated in various important metabolic pathways directed towards bioenergetics support mechanisms including glycerophospholipid metabolism, the citrate cycle (TCA cycle), glyoxylate and dicarboxylate metabolism, and serine, threonine, and tyrosine metabolism. Our study presents important metabolites and metabolic pathways involved in the adaptation of bGCs to acute heat stress in vitro.

Highlights

Heat stress deserves more attention as a climate change impact of unregulated global warming [1] and presents an important challenge to food security [2], public health [3], and sustainable dairy farming [4,5]
Heat stress effects on granulosa cells cause alterations in hormone secretions and disturbs the molecular signaling needed for oocyte development
This study provided evidence of transient acute heat stress characterized by high ROS production, increased rate of apoptosis, diminished progesterone concentration, and time-dependent recovery of cell proliferation in bovine granulosa cells under in vitro culture conditions

Summary

Introduction

Heat stress deserves more attention as a climate change impact of unregulated global warming [1] and presents an important challenge to food security [2], public health [3], and sustainable dairy farming [4,5]. Increased rates of granulosa cells apoptosis are associated with diminished ovarian reserves and poor fertility outcomes [20]. Heat stress triggers a series of energetic metabolism changes in the body [25], high non-esterified fatty acids, ketone bodies, induction of inflammatory cytokines, and dynamic role of different metabolites can alter the ovarian follicular biochemical profile [10,23,26–29]. This is why heat stress-mediated alterations of the follicular biochemical profile have been associated with granulosa cell dysfunction and poor oocyte developmental competence [25,30–33]. This study selected 43 ◦C for a duration of 2 h to confirm the consistency of the physical insult to the granulosa cells (with the mentioned previous studies) and collect samples for further investigation

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Results

Discussion

Conclusion