Negative effects of heat stress on ovarian tissue in female rabbit

Abstract

Numerous studies have highlighted the role of miRNA in the deformation and necrosis of cells of ovarian tissue caused by heat stress (HS), which ultimately affects ovarian function. Although the role of small RNAs has been investigated in alterations in ovarian tissue functioning in response to HS, the expression profile of ovarian miRNA has been explored to a lesser extent. In this study, female rabbits were subject to HS treatment by using electrical heater. The current work demonstrated that HS could significantly change physiological performance of female rabbits including body weight, rectal temperature and relative ovary weight, and significantly reduce serum IL-2, IL-8, CAT, and GSH-Px concentrations by enzyme-linked immunosorbent assay (ELISA) technique. As a result, an increase in apoptosis in ovarian cells, as well as unhealthy follicles, were observed by Hematoxylin-eosin (HE) and TUNEL staining. Additionally, small RNA-seq revealed changes in the miRNA expression profile of rabbit ovaries under HS. Five hundred fourteen miRNAs were obtained including known miRNAs 442 and novel miRNAs 72. Among these miRNAs, 23 miRNAs were significantly expressed under HS. Eleven differentially expressed miRNAs (DE miRNAs) and 9 their predicted targets were confirmed by qPCR, which were expected miRNA–mRNA negative regulation pattern. Among the DE miRNAs and targets, miR-141-39 may target COQ6, miR-449a-5p and miR-34c-5p may control RFC5 and RTN2 together, miR-449a-5p may target ACADVL, miR-34c-5p potentially targets Bcl-2 and miR-196b-5p potentially regulates CASK and HOXB6. Thus, the current work suggested the negative effects of HS on the ovarian tissue of female rabbits, and in conclusion these changes could be caused by decreased serum IL-2, IL-8, CAT and GSH-Px levels, increased ovarian apoptosis, and changed the expression of miRNAs.

miR-196a Promotes Proliferation of Mammary Epithelial Cells by Targeting CDKN1B

“…In a previous HS experiment with rabbits, our team identified 23 differentially expressed miRNAs, including miR-196a, between tissues under HS and a control condition [5]. This information suggests that miR-196a, identified in the study, could play a role in modulating cellular physiological changes during HS.…”

“…These findings suggest that miR-196a may play an important regulatory function in the mammary glands of dairy cows. One of our previous studies suggested that miR-196a may be involved in regulating the alteration of the physiology of the animal organism under HS [5]. We established an HS model using BMECs to investigate whether miR-196a regulates the mammary gland's One of our previous studies suggested that miR-196a may be involved in regulating the alteration of the physiology of the animal organism under HS [5].…”

“…One of our previous studies suggested that miR-196a may be involved in regulating the alteration of the physiology of the animal organism under HS [5]. We established an HS model using BMECs to investigate whether miR-196a regulates the mammary gland's One of our previous studies suggested that miR-196a may be involved in regulating the alteration of the physiology of the animal organism under HS [5]. We established an HS model using BMECs to investigate whether miR-196a regulates the mammary gland's physiological response to HS in dairy cows.…”

Ramifications of Heat Stress on Rabbit Production and Role of Nutraceuticals in Alleviating Its Negative Impacts: An Updated Review

“…Several studies documented that a long exposure to thermal stress resulted in oxidative stress, consequently deteriorating rabbit females' endocrine system and ovarian physiological functions [26,62]. It was noted that exposure to HS reduced the relative weight of the ovary [62,63]. Additionally, exposure to HS resulted in the impairment of ovarian granulosa cells' responsiveness, reducing plasma progesterone concentration, destructing the ovarian cell nucleoli, and weakening the responsiveness of ovarian granulosa cells to follicle-stimulating hormone (FSH) in rabbit does [26].…”

“…Moreover, HS increased mortality in both adult mothers and offspring and deteriorated offspring growth [26]. Tang et al [63] pointed out that HS had a negative influence on the physiological performance of female rabbits in terms of ovary weight % and plasma contents of interleukin (IL)-2, IL-8, catalase (CAT), and glutathione peroxidase (GSH-Px), and accelerated ovarian apoptosis and unhealthy follicles, as well as altered miRNAs expression in rabbit does. The CAT and GSH-Px play a vital role as antioxidative enzymes in rabbits' earlier phases of folliculogenesis; therefore, exposure to HS suppressed ovarian folliculogenesis, maturation, and ovulation [64].…”