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.

The determination of sex in mammals is established and controlled by various complex mechanisms. In contrast, sex control in poultry remains an unresolved issue. In this study, RNA-sequencing was conducted for male gonads and ovarian tissues in chicken embryos of up to 18.5 days to identify metabolic factors influencing male and female sex differentiation, as well as gonadal development. Our results reveal that PKM2, a critical glycolysis-related protein, plays a significant role in chicken sex differentiation via PPARG, a crucial hormone gene. We propose that our discoveries bolster the notion that glycolysis and oxidative phosphorylation function as antecedent contributors to sexual phenotypic development and preservation.

Background: The Jun proto-oncogene (JUN), also referred to as C-JUN, is an integral component of the JNK signaling pathway, which is crucial for the formation and differentiation of spermatogonial stem cells (SSCs). Investigations into the transcriptional regulation of chicken JUN can offer a molecular foundation for elucidating its mechanistic role in SSCs. Methods: In this study, we successfully cloned a 2000 bp upstream sequence of the JUN transcription start site and constructed a series of pGL3 recombinant vectors containing JUN promoters of varying lengths. Results: We verified the promoter activity of the 2000 bp upstream sequence by assessing the fluorescence intensity of DF-1 and identified the promoter activities of different regions via dual-luciferase assays. The transcription of JUN and its promoter region spanning −700 to 0 bp was modulated by an activator of the JNK signaling pathway. Bioinformatics analysis revealed that this −700 to 0 bp region was highly conserved among avian species and predicted the presence of binding sites for Wilms tumor 1 (WT1) and CCAAT/enhancer binding protein alpha (CEBPA). The JNK signaling pathway activator was found to upregulate the expression of these transcription factors in DF-1 cells. Through the deletion of binding sites and the overexpression of WT1 and CEBPA, we demonstrated that WT1 inhibited the transcription of JUN, while CEBPA promoted it. Conclusions: In conclusion, the −700 to 0 bp region is the key region of the JUN promoter, with WT1 inhibiting JUN transcription. The results of the study not only provide ideas for exploring the regulatory mechanism of JUN in chicken SSCs, but also lay an important foundation for the study of avian SSCs.

Background: Histone deacetylase 4 (HDAC4) is a member of the class II histone deacetylase family, whose members play a crucial role in various biological processes. An in-depth investigation of the transcriptional characteristics of chicken HDAC4 can provide fundamental insights into its function. Methods: We examined HDAC4 expression in chicken embryonic stem cells (ESC) and spermatogonial stem cells (SSC) and cloned a 444 bp fragment from upstream of the chicken HDAC4 transcription start site. Subsequently, we constructed pEGFP-HDAC4 and a series of 5′-deletion luciferase reporter constructs, which we transfected into DF-1 cells to measure their transcriptional activity. The regulatory mechanisms of chicken HDAC4 expression were investigated by performing trichostatin A (TSA) treatment, deleting putative transcription factor binding sites, and altering transcription factor expression levels. Results: HDAC4 exhibited higher expression in SSC than in ESC. We confirmed that the upstream region from −295 bp to 0 bp is the core transcriptional region of HDAC4. TSA effectively inhibited HDAC4 transcription, and bioinformatics analysis indicated that the chicken core HDAC4 promoter sequence exhibits high homology with those of other avian species. The myelocytomatosis viral oncogene homolog (MYC) and hypoxia-inducible factor 1 α (HIF1A) transcription factors were predicted to bind to this core region. Treatment with TSA for 24 h resulted in the upregulation of MYC and HIF1A, which repressed HDAC4 transcription. Conclusions: Our results provide a basis for subsequent investigations into the regulation of HDAC4 expression and biological function.

The journal retracts the article “Analysis of the Molecular Mechanism of Energy Metabolism in the Sex Differentiation of Chickens Based on Transcriptome Sequencing”