The Mongolian sheep, emblematic of the Inner Mongolian grasslands, is renowned for its exceptional stress resistance and adaptability to harsh environments, drawing considerable attention. Recent research has unveiled the novel role of γ-aminobutyric acid (GABA) in combating oxidative stress. This investigation examined how GABA impacts renal-cortex and medulla cells from Mongolian sheep exposed to high-glucose stress conditions, utilizing gene expression analysis and non-targeted metabolomics. Elevated glucose levels significantly reduced the viability of Mongolian sheep renal cells and increased reactive oxygen species (ROS) levels. Conversely, the introduction of GABA notably enhanced cell viability, reduced ROS production, and stimulated the expression of antioxidant genes (e.g., Gpx, SOD, CAT) in the renal cortex. In the renal medulla, CAT expression increased, while Gpx gene expression showed mixed responses. Metabolomics analysis indicated that high-glucose exposure altered various metabolites, whereas GABA alleviated the metabolic stress induced by high glucose through modulating glycolysis and the tricarboxylic acid cycle. In Mongolian sheep renal cells, GABA effectively mitigated oxidative damage triggered by high-glucose stress by upregulating antioxidant genes and regulating metabolic pathways, revealing insights into its potential mechanism for adapting to extreme environments. This finding offers a fresh perspective on understanding the stress resilience of Mongolian sheep and may provide valuable insights for research across diverse disciplines.
14 July 2024 in Comparative Biochemistry and Physiology Part D: Genomics and Proteomics
Sunite sheep are well-adapted to the cold Mongolian steppe, exhibiting robust metabolic flexibility in which adipose tissue contributes significantly to energy homeostasis. Proteomics analysis of scapular fat in Sunite sheep during winter and summer identified 432 upregulated and 493 downregulated differentially expressed proteins (DEPs). These DEPs were notably enriched in essential biological functions such as energy metabolism, lipogenesis, and thermogenesis. Furthermore, they exhibited significant enrichment of signaling pathways such as oxidative phosphorylation and fatty acid metabolism. Meanwhile, the precursor protein of asprosin (ASP),profibrillin-1 (pFBN1), showed a marked decrease during winter. Given that ASP had been demonstrated to exert metabolic regulatory effects promoting lipid synthesis and suppressing thermogenesis in model animals, it was hypothesized that the seasonal downregulation of pFBN1 might drive adaptive thermogenesis through ASP. Therefore, this study focused on functional validation of the ASP-encoding gene FBN1 (fibrillin-1). In Adipose-Derived Mesenchymal Stem Cells (ADMSCs), FBN1 was specifically downregulated through overexpressing of its regulatory factor miR-29b-1. The results indicated that downregulation of the FBN1 led to the inhibition of adipogenesis in ADMSCs. This was reflected by a reduction in the number of lipid droplets, a decrease in the expression of adipogenesis marker genes, and a significant drop in triglyceride levels. Furthermore, the reduction in FBN1 levels enhanced the thermogenic function of differentiated adipocytes derived from ADMSCs, as evidenced by enhanced expression of thermogenic marker genes, along with a notable rise in both uncoupling protein 1 (UCP1) and non-esterified fatty acid (NEFA) levels.
Peste des petits ruminants virus (PPRV) causes a highly fatal disease that severely impacts small ruminant production and global food security. This study aimed to develop a rapid, user-friendly colloidal gold immunochromatographic test strip for detecting PPRV-specific antibodies using a double-antigen sandwich format. Bioinformatic analysis using DNASTAR Protean was performed to predict candidate antigenic regions in the PPRV H and N proteins. Three predicted candidate regions from each protein were selected and incorporated into the design of the recombinant fusion antigen PPRV-H3N3EP. The recombinant antigen was expressed in E. coli, purified, and refolded to obtain a final concentration of 8.52 mg/mL. The strip was assembled with colloidal gold-labeled fusion protein as the detection probe and unlabeled protein coated on the test line, plus an independent mouse IgG/goat anti-mouse IgG control system. Performance evaluation showed that the results were readable within 10–15 min. The strip showed satisfactory analytical sensitivity and cross-reactivity performance, consistent qualitative results in within-batch repeatability testing, and preliminary short-term storage stability. In a comparative evaluation using sheep serum samples and a commercial competitive enzyme-linked immunosorbent assay (ELISA) kit, the overall agreement reached 97.9%. Collectively, the constructed PPRV-H3N3EP antigen enabled a simple, rapid, and reliable strip assay suitable for field detection of PPRV antibodies and post-vaccination monitoring, while also providing a methodological reference for developing antibody tests for other pathogens.
Rising global temperatures lead to a continuous increase in the frequency and intensity of extreme weather events, such as droughts and floods, posing serious threats to terrestrial homeotherms. However, adaptive changes in respiratory metabolism and molecular mechanisms in lung tissues of small mammals under extreme water shortage conditions remain unclear. This study hypothesized that small desert mammals can adapt to extreme water shortage environments by regulating the plasticity of lung tissue gene expression and respiratory metabolism. Using 29 wild-caught Siberian jerboas (Orientallactaga sibirica) as subjects, we implemented a 12-day complete water deprivation protocol to simulate extreme aridity. Body weight, food intake, and daily energy expenditure (DEE) were monitored throughout the experiment. Whole-transcriptome sequencing of lung tissues was performed to profile mRNA, circRNA, and miRNA expression, with competitive endogenous RNA (ceRNA) network analysis to explore molecular mechanisms underlying lung adaptation to water deprivation. Over the 12-day water deprivation (WS) period, Orientallactaga sibirica (O. sibirica) exhibited a 30.3% reduction in body mass and a 68.1% decrease in food intake relative to the baseline level. DEE during the peak activity period at the end of the experiment was 12.6% lower in the WS group compared to the control group. In lung tissue, structural integrity-related genes (Mybl2, Ccnb1) were downregulated. A key finding was that circ_0015576 exhibits a significant positive correlation with the potassium channel gene Kcnk15 and a robust negative correlation with miR-503-5p—suggesting that circ_0015576 functions as a competing endogenous RNA (ceRNA) to sequester miR-503-5p and thereby derepress Kcnk15 expression. Core regulatory genes (ApoA4, Dusp15 etc.) were also coordinately downregulated. Collectively, these results indicate that O. sibirica reduces overall energy expenditure, which may be associated with lung gene expression plasticity, such as those related with lung cell proliferation, pulmonary function, and gas exchange efficiency. This metabolic downregulation facilitates energy conservation under severe water scarcity.