MicroRNA-129-1-3p attenuates autophagy-dependent cell death by targeting MCU in granulosa cells of laying hens under H2O2-induced oxidative stress

Quantitative Proteomics Analysis Reveals XDH Related with Ovarian Oxidative Stress Involved in Broodiness of Geese

Studies have demonstrated significant alterations in ovarian oxidative stress levels, ovarian degeneration, and follicular atresia during the broody period in geese. The results of this study showed that during the broody period, geese exhibited degraded ovarian tissues, disrupted follicular development, a thinner granulosa cell layer, and lower levels of ovarian hormones E2, P4, and AMH. Antioxidant activity (GSH, CAT, SOD, T-AOC, and the content of H2O2) and the mRNA expression levels of antioxidant genes (GPX, SOD-1, SOD-2, CAT, COX-2, and Hsp70) were significantly higher in pre-broody geese compared to laying geese, while the expression of apoptosis-related genes (p53, Caspase-3, and Caspase-9) increased and the anti-apoptotic gene Bcl-2 decreased. Additionally, proteomic analysis identified 703 differentially expressed proteins (DEPs), primarily concentrated in the GO categories of the biological process (biological regulation, response to stimulus, etc.) and enriched in the KEGG pathways (PI3K-Akt signaling pathway, etc.). Among them, XDH was central to the regulatory network. Furthermore, Western blotting revealed higher expression of XDH in the ovaries of pre-broody geese than those of laying geese. Pearson correlation analysis indicated a significant correlation between XDH expression and oxidative stress markers in the ovaries of geese (r > 0.75). Overall, these results demonstrated that geese experience ovarian atrophy and remarkably increased oxidative stress during the broody period, suggesting that XDH may be a key driver of broodiness in geese.

miR-317 regulates the proliferation and apoptosis of duck follicle granulosa cells by targeting VIPR1

VIPR1 can specifically bind VIP, a PRL release factor, which promotes the secretion of PRL from the pituitary gland, and participates in the regulation of bird nesting behavior. The purpose of this study was to investigate the effects of miR-317 overexpression or silencing on VIPR1 gene and protein expression in duck follicle granulosa cells. The ovaries of Muscovy ducks were collected during the nesting and laying periods, and histological differences were analyzed via HE staining. Duck primary follicle granulosa cells were isolated and identified by immunofluorescence staining, after which the cells were transfected with miR-317, mimic-NC, miR-317 mimic, inhibitor-NC or miR-317 inhibitor Alterations in cell proliferation were then analyzed by EdU staining, and cell apoptosis was assessed by Annexin-V-FITC flow cytometry and TUNEL staining. Fluorescence quantitative PCR was used to assess the expression level of VIPR1 after miR-317 overexpression or silencing. Total protein was extracted from the follicle granulosa cells, and protein levels were analyzed via Western blotting. The results revealed that the nucleus of the ovarian granule in Muscovy ducks was more concentrated and distinct from the surrounding cells during the brooding period than during the laying period. More than 90 % of the cells were identified as duck follicle granulosa cells by immunofluorescence staining of FSHR and LHR. miR-317 expression was significantly higher in the miR-317 mimic-transfected group than in the miRNA-NC-transfected group (P < 0.01); similarly, miR-317 expression was significantly lower in the inhibitor-transfected group than in the miRNA inhibitor-transfected group (P < 0.01), indicating that miR-317 overexpression and interference vectors were successfully constructed and transfected into duck follicular granulosa cells. EdU staining revealed that the number of EdU-positive cells was significantly greater in the miR-317 mimic-transfected group than in the mimic-NC-transfected group (P < 0.05); after miR-317 silencing or inhibition, cell proliferation decreased, and the number of EdU-positive cells significantly decreased (P < 0.01). TUNEL staining revealed that the proportion of red, TUNEL-positive cells in the miR-317 inhibitor interference group was significantly greater than that in the miR-NC, miR-317 mimic, or inhibitor-NC group (P < 0.05). These results suggest that miR-317 inhibition promoted the apoptosis of duck follicle granulosa cells. Flow cytometry revealed that the percentage of apoptotic cells was 14.23 % and 22.75 % in the inhibitor-NC and miR-317 inhibitor groups, respectively (P < 0.01). Fluorescence quantitative PCR revealed that, compared with that in the corresponding control groups, VIPR1 gene expression was significantly lower in the miR-317 mimic group (P < 0.05) but significantly higher in the miR-317 inhibitor group (P < 0.05). Western blot analysis revealed that VIPR1 levels were significantly lower in the miR-317 mimic group than in the mimic-NC group (P < 0.05) but significantly greater in the miR-317 inhibitor group (P < 0.05). In summary, miR-317 inhibition promoted the apoptosis of duck follicle granulosa cells, and miR-317 overexpression promoted the proliferation of duck follicle granulosa cells and negatively regulated expression of the target gene VIPR1 at the gene and protein levels. This study further reveals the molecular mechanism underlying follicular atresia and serves as a reference for reducing the broodiness of Muscovy ducks.

Supplementation of Chlorogenic Acid Alleviates the Effects of H2O2-Induced Oxidative Stress on Laying Performance, Egg Quality, Antioxidant Capacity, Hepatic Inflammation, Mitochondrial Dysfunction, and Lipid Accumulation in Laying Hens

This research examined the impact of chlorogenic acid (CGA) on laying performance, antioxidant capacity, egg quality, hepatic inflammation, mitochondrial function, and lipid metabolism in hens subjected to hydrogen peroxide (H2O2)-induced oxidative stress (OS). Three hundred sixty healthy 43-wk-old Hy-Line brown hens were randomly assigned to six treatments: a basal diet + 0 (control and H2O2), 600 (600 mg/kg CGA and 600 mg/kg CGA + H2O2), and 800 (800 mg/kg CGA and 800 mg/kg CGA + H2O2) mg/kg CGA for 84 d. On the 64th and 78th days of the trial, hens in groups H2O2, 600 mg/kg CGA + H2O2, and 800 mg/kg CGA + H2O2 were injected intraperitoneally with 10% H2O2. The results demonstrated that 600 and 800 mg/kg CGA significantly improved the egg production rate (EPR) and egg quality and reduced lipid peroxidation compared to the control group. The 800 mg/kg CGA showed greater improvements in the EPR and average egg weight (AEW) compared to the 600 mg/kg dose. Conversely, H2O2 exposure significantly decreased the EPR, AEW, and egg quality and increased feed conversion rate and average daily feed intake. H2O2 exposure significantly decreased serum T-AOC and increased serum MDA levels while reducing hepatic T-SOD, GSH-Px, and CAT activities. Meanwhile, H2O2 exposure significantly elevated liver reactive oxygen species levels, pathological damage, and NF-κB, TNFα, and IL-1β gene expression. Additionally, H2O2 treatment disrupted hepatocyte mitochondrial structure and significantly increased the expression of VDAC1 protein, and IP3R, GRP75, MCU, Fis1, and MFF genes, while downregulating the expression of MFN2 protein and PGC1α gene. Oil Red O staining demonstrated that H2O2 induced significant lipid accumulation in hepatocytes. Concurrently, H2O2 significantly increased serum triglycerides, total cholesterol, and liver triglycerides levels while decreasing serum hepatic lipase activity. This was primarily attributed to the significant upregulation of liver SREBP1, FASN, and ACC genes and the downregulation of the liver CPT1 gene induced by H2O2. Furthermore, CGA pretreatment effectively prevented the degeneration in laying performance and egg quality, as well as OS, liver inflammation, pathological damage, and mitochondrial dysfunction induced by H2O2. CGA inhibited H2O2-induced hepatic lipid accumulation by upregulating fatty acid oxidation-related gene expression and downregulating fatty acid synthesis-related gene expression. These findings indicate that the dietary addition of 800 mg/kg of CGA is the optimum supplementation dose. CGA can enhance laying performance and egg quality while alleviating OS, hepatic inflammation, mitochondrial dysfunction, and lipid accumulation in H2O2-challenged laying hens.

Quail GHRL and LEAP2 gene cloning, polymorphism detection, phylogenetic analysis, tissue expression profiling and its association analysis with feed intake

The GHRL, LEAP2, and GHSR system have recently been identified as important regulators of feed intake in mammals and chickens. However, the complete cloning of the quail GHRL (qGHRL) and quail LEAP2 (qLEAP2) genes, as well as their association with feed intake, remains unclear. This study cloned the entire qGHRL and qLEAP2 cDNA sequence in Chinese yellow quail (Coturnix japonica), including the 5' and 3' untranslated regions. Sanger sequencing analysis revealed no missense mutations in the coding region of qGHRL and qLEAP2. Subsequently, phylogenetic analysis and protein homology alignment were conducted on the qGHRL and qLEAP2 in major poultry species. The findings of this research indicated that the qGHRL and qLEAP2 sequences exhibit a high degree of similarity with those of chicken and turkey. Specifically, the N-terminal 6 amino acids of GHRL mature peptides and all the mature peptide sequence of LEAP2 exhibited consistent patterns across all species examined. The analysis of tissue gene expression profiles indicated that qGHRL was primarily expressed in the proventriculus and brain tissue, whereas qLEAP2 exhibited higher expression levels in the intestinal tissue, kidney, and liver tissue, differing slightly from previous studies conducted on chicken. It is necessary to investigate the significance of elevated expression of qGHRL in brain and qLEAP2 in kidney in the future. Further research has shown that the expression of qLEAP2 can quickly respond to changes in different energy states, whereas qGHRL does not exhibit the same capability. Overall, this study successfully cloned the complete cDNA sequences of qGHRL and qLEAP2, and conducted a comprehensive examination of their tissue expression profiles and gene expression levels in the main expressing organs across different energy states. Our current findings suggested that qLEAP2 is highly expressed in the liver, intestine, and kidney, and its expression level is regulated by feed intake.

Chicken ovarian follicular atresia: interaction network at organic, cellular, and molecular levels

Most of follicles undergo a degenerative process called follicular atresia. This process directly affects the egg production of laying hens and is regulated by external and internal factors. External factors primarily include nutrition and environmental factors. In follicular atresia, internal factors are predominantly regulated at 3 levels; organic, cellular and molecular levels. At the organic level, the hypothalamic-pituitary-ovary (HPO) axis plays an essential role in controlling follicular development. At the cellular level, gonadotropins and cytokines, as well as estrogens, bind to their receptors and activate different signaling pathways, thereby suppressing follicular atresia. By contrast, oxidative stress induces follicular atresia by increasing ROS levels. At the molecular level, granulosa cell (GC) apoptosis is not the only factor triggering follicular atresia. Autophagy is also known to give rise to atresia. Epigenetics also plays a pivotal role in regulating gene expression in processes that seem to be related to follicular atresia, such as apoptosis, autophagy, proliferation, and steroidogenesis. Among these processes, the miRNA regulation mechanism is well-studied. The current review focuses on factors that regulate follicular atresia at organic, cellular and molecular levels and evaluates the interaction network among these levels. Additionally, this review summarizes atretic follicle characteristics, in vitro modeling methods, and factors preventing follicular atresia in laying hens.

MicroRNA-129-1-3p protects chicken granulosa cells from cadmium-induced apoptosis by down-regulating the MCU-mediated Ca2+ signaling pathway

Cadmium (Cd) is known as a female reproductive toxicant. Our previous study has shown that Cd can influence the proliferation and cell cycle of granulosa cells and induce apoptosis. MicroRNAs (miRNAs) play an important role in the regulation of Cd-induced granulosa cell damage in chickens. However, the mechanism remains unclear. In this study, we investigated the mechanisms by which microRNA-129-1-3p (miR-129-1-3p) regulates Cd-induced cytotoxicity in chicken granulosa cells. As anticipated, exposure to Cd resulted in the induction of oxidative stress in granulosa cells, accompanied by the downregulation of antioxidant molecules and/or enzymes of Nrf2, Mn-SOD, Cu-Zn SOD and CAT, and the upregulation of Keap1, GST, GSH-Px, GCLM, MDA, hydrogen peroxide and mitochondrial reactive oxygen species (mtROS). Further studies found that Cd exposure causes mitochondrial calcium ions (Ca2+) overload, provoking mitochondrial damage and apoptosis by upregulating IP3R, GRP75, VDAC1, MCU, CALM1, MFF, caspase 3, and caspase 9 gene and/or protein expressions and mitochondrial Ca2+ levels, while downregulating NCX1, NCLX and MFN2 gene and/or protein expressions and mitochondrial membrane potential (MMP). The Ca2+ chelator BAPTA-AM or the MCU inhibitor MCU-i4 significantly rescued Cd-induced mitochondrial dysfunction, thereby attenuating apoptosis. Additionally, a luciferase reported assay and western blot analysis confirmed that miR-129-1-3p directly target MCU. MiR-129-1-3p overexpression almost completely inhibited protein expression of MCU, increased the gene and protein expressions of NCLX and MFN2 downregulated by Cd, and attenuated mitochondrial Ca2+ overload, MMP depression and mitochondria damage induced by Cd. Moreover, the overexpression of miR-129-1-3p led to a reduction in mtROS and cell apoptosis levels, and a suppression of the gene and protein expressions of caspase 3 and caspase 9. As above, these results provided the evidence that IP3R-MCU signaling pathway activated by Cd plays a significant role in inducing mitochondrial Ca2+ overload, mitochondrial damage, and apoptosis. MiR-129-1-3p exerts a protective effect against Cd-induced granulosa cell apoptosis through the direct inhibition of MCU expression in the ovary of laying hens.