Metabolomic Analysis of SCD during Goose Follicular Development: Implications for Lipid Metabolism

Synergistic transcriptomic and metabolomic analyses in Zi geese ovaries with different clutch lengths

The clutch is defined as consecutive days of oviposition. Clutch length is an index that reflects ovulation persistence, and is highly correlated with egg production in birds. To identify the genetic markers associated with clutch length in geese, two consecutive experiments were conducted. In the first experiment, 200 Zi geese were selected, all 230 days old, were selected from the same batch and raised individually in the same environment. Data of egg-laying and clutch traits were recorded. After the laying period, three geese with the longest clutch lengths were selected to form the length clutch group (LCG) and three geese with the shortest clutch lengths were formed the short clutch group (SCG). In the second experiment, the ovaries of six geese were collected for transcriptomic and metabolomic analyses. The results showed that large clutch length (LCL) and average clutch length (ACL) were positively correlated with egg number (EN) (P < 0.01; r = 0.63 and 0.60, respectively). Large clutch number (LCN) was significantly correlated with the peak egg number (PEN) (r = 0.58, P < 0.01) and EN (r = 0.60, P < 0.01). EN, LCN, LCL, and ACL showed significant differences (P < 0.01) between the two clutch length groups. Transcriptomic analysis identified 424 differentially expressed genes (DEGs). Functional enrichment analysis revealed that these DEGs were mainly involved in neuroactive ligand-receptor interactions, ovarian steroidogenesis, and calcium signaling pathways. Further, AVPR1A, FGF14, and LHCGR were predicted as the key genes regulating LCL. Metabolomic analysis identified 349 differential metabolites (DMs) in both the positive and negative ion modes. Pyruvate, isocitric acid, D/L‑serine, 3-phospho-d-glycerate, succinate, glycine, and glutamic acid were identified as the key metabolites mainly enriched in the signaling pathways of the TCA cycle. Integration of transcriptomic and metabolomic data revealed critical gene-metabolite pairs, including ACSL4-phosphoenolpyruvate, implicated in LCL regulation. In summary, this study provides new insights into the genes and molecular markers affecting LCL in Zi geese.

Advance in the application of metabolomics technology in poultry

Metabolomics is a science that takes small molecular metabolites in organisms as the research object and determines the dynamic changes of metabolites at the overall level through a variety of modern analytical techniques. At present, metabolomics technology has been widely used in biological significance interpretation, food safety and quality, breeding, disease diagnosis, functional compound identification, and other fields. Its application in poultry science has also become the focus of widespread attention. With the sustainable development of analytical techniques, metabolomics has great potential in the application of poultry science. In this paper, the research progress of metabolomics in poultry growth and development, genetics and breeding, egg quality, meat quality, and disease is reviewed and concluded, which is expected to provide scientific ideas for the research of metabolomics in poultry.

miR-24-3p inhibits lipid synthesis and progesterone secretion in chicken granulosa cells via ERK1/2 signaling pathway

Normal follicular development is the basis for ovulation in poultry. Our previous sequencing analysis revealed a high expression of miR-24-3p in chicken follicles from degenerated ovaries, suggesting that miR-24-3p may modulate follicular development. Hence, this study investigated the specific mechanisms of miR-24-3p in regulating chicken follicular development. The results revealed that the proliferation, lipid synthesis, and progesterone secretion were significantly inhibited after miR-24-3p overexpression in chicken granulosa cells, vice versa by miR-24-3p knockdown. Dual-specificity phosphatase 16 (DUSP16) and thousand and one amino acid kinase 1 (TAOK1) were identified as potential target genes of miR-24-3p. Further validation revealed that knockdown of DUSP16 and TAOK1 suppressed proliferation, lipid synthesis, and progesterone secretion in chicken granulosa cells. Moreover, we observed that miR-24-3p, along with knockdown of DUSP16 and TAOK1, increased the phosphorylation levels of extracellular signal-regulated kinases 1 and 2 (ERK1/2). Our previous study proved that activation of ERK1/2 inhibited lipid synthesis and progesterone secretion of chicken granulosa cells. In summary, we demonstrated that miR-24-3p targeting DUSP16 and TAOK1 disrupts lipid synthesis and progesterone secretion via ERK1/2 signaling pathway in chicken granulosa cells in vitro. These results may provide a new theoretical basis for resolving miRNAs regulation on reproductive performance of chickens.

Ovary metabolome and cecal microbiota changes in aged laying hens supplemented with vitamin E

This study was aimed to evaluate the effect of vitamin E (VE) on laying performance, VE deposition, antioxidant capacity, immunity, follicle development, estrogen secretion, ovary metabolome, and cecal microbiota of laying hens. One hundred and twenty XinYang Black-Feathered laying hens (70 wk old) were randomly assigned to 2 groups (6 replicates of 20 birds), and fed a basal diet (containing 20 mg/kg VE, control (CON) group) and a basal diet supplemented with 20 mg/kg VE (VE group). The experiment lasted for 10 wk. Results showed that VE supplementation increased laying performance, antioxidant capacity, and immunity, as evidenced by increased (P < 0.05) performance (laying rate), antioxidant (glutathione peroxidase, total superoxide dismutase, total antioxidant capacity, and catalase) and immune (immunoglobulins) parameters, and decreased (P < 0.05) feed/egg ratio and malondialdehyde. Meanwhile, VE group had higher (P < 0.05) pregrade follicles, ovary index and serum estrogen levels than CON group. 16S rRNA sequencing showed that VE supplementation altered the cecal microbiota composition by increasing Bacteroides, Rikenellaceae_RC9_gut_group, Prevotellaceae_UCG-001 and Megamonas abundances and reducing Christensenellaceae_R-7_group abundance (at genus level), which are mainly associated with the production of short-chain fatty acids. Metabolomic profiling of the ovary revealed that the major metabolites altered by VE supplementation were mainly related to follicle development, estrogen secretion, anti-inflammatory, antioxidant, phototransduction, bile acid synthesis, and nutrient transport. Furthermore, changes in cecal microbiota (at genus level) and ovary metabolites were highly correlated with laying performance, antioxidant, and immune parameters. In summary, VE contributed to the laying performance of aged laying hens by enhancing antioxidant, immune, and ovarian functions, promoting follicle development and estrogen secretion, and regulating gut microbiota and ovary metabolites. These findings will provide a new perspective on the mechanisms of egg production in aged poultry ovaries.

Transcriptomic and metabolomic analyses of the ovaries of Taihe black-bone silky fowls at the peak egg-laying and nesting period

The poor reproductive performance of most local Chinese chickens limits the economic benefits and output of related enterprises. As an excellent local breed in China, Taihe black-bone silky fowl is in urgent need of our development and utilization. In this study, we performed transcriptomic and metabolomic analyses of the ovaries of Taihe black-bone silky fowls at the peak egg-laying period (PP) and nesting period (NP) to reveal the molecular mechanisms affecting reproductive performance. In the transcriptome, we identified five key differentially expressed genes (DEGs) that may affect the reproductive performance of Taihe black-bone silky fowl: BCHE, CCL5, SMOC1, CYTL1, and SCIN, as well as three important pathways: the extracellular region, Neuroactive ligand-receptor interaction and Cytokine-cytokine receptor interaction. In the metabolome, we predicted three important ovarian significantly differential metabolites (SDMs): LPC 20:4, Bisphenol A, and Cortisol. By integration analysis of transcriptome and metabolome, we identified three important metabolite-gene pairs: "LPC 20:4-BCHE", "Bisphenol A-SMOC1", and "Cortisol- SCIN". In summary, this study contributes to a deeper understanding of the regulatory mechanism of egg production in Taihe black-bone silky fowl and provides a scientific basis for improving the reproductive performance of Chinese local chickens.

The oxidative aging model integrated various risk factors in type 2 diabetes mellitus at system level

Background

Type 2 diabetes mellitus (T2DM) is a chronic endocrine metabolic disease caused by insulin dysregulation. Studies have shown that aging-related oxidative stress (as "oxidative aging") play a critical role in the onset and progression of T2DM, by leading to an energy metabolism imbalance. However, the precise mechanisms through which oxidative aging lead to T2DM are yet to be fully comprehended. Thus, it is urgent to integrate the underlying mechanisms between oxidative aging and T2DM, where meaningful prediction models based on relative profiles are needed.

Methods

First, machine learning was used to build the aging model and disease model. Next, an integrated oxidative aging model was employed to identify crucial oxidative aging risk factors. Finally, a series of bioinformatic analyses (including network, enrichment, sensitivity, and pan-cancer analyses) were used to explore potential mechanisms underlying oxidative aging and T2DM.

Results

The study revealed a close relationship between oxidative aging and T2DM. Our results indicate that nutritional metabolism, inflammation response, mitochondrial function, and protein homeostasis are key factors involved in the interplay between oxidative aging and T2DM, even indicating key indices across different cancer types. Therefore, various risk factors in T2DM were integrated, and the theories of oxi-inflamm-aging and cellular senescence were also confirmed.

Conclusion

In sum, our study successfully integrated the underlying mechanisms linking oxidative aging and T2DM through a series of computational methodologies.

Mechanism of SCD Participation in Lipid Droplet-Mediated Steroidogenesis in Goose Granulosa Cells

Stearoyl-CoA desaturase (SCD) is a key enzyme catalyzing the rate-limiting step in monounsaturated fatty acids (MUFAs) production. There may be a mechanism by which SCD is involved in lipid metabolism, which is assumed to be essential for goose follicular development. For this reason, a cellular model of SCD function in goose granulosa cells (GCs) via SCD overexpression and knockdown was used to determine the role of SCD in GC proliferation using flow cytometry. We found that SCD overexpression induced and SCD knockdown inhibited GCs proliferation. Furthermore, ELISA analysis showed that SCD overexpression increased the total cholesterol (TC), progesterone, and estrogen levels in GCs, while SCD knockdown decreased TC, progesterone, and estrogen levels (p < 0.05). Combining these results with those of related multi-omics reports, we proposed a mechanism of SCD regulating the key lipids and differentially expressed gene (DEGs) in glycerophospholipid and glycerolipid metabolism, which participate in steroidogenesis mediated by the lipid droplet deposition in goose GCs. These results add further insights into understanding the lipid metabolism mechanism of goose GCs.

Comparative transcriptome analysis of MDBK cells reveals that BoIFN-γ augmented host immune responses to bovine herpesvirus 1 infection

Bovine herpesvirus 1 (BoHV-1) is an alphaherpesvirus that causes infectious bovine rhinotracheitis and infectious pustular vulvovaginitis in cattle. Ιnterferon-gamma (IFN-γ) is a pleiotropic cytokine with antiviral activity that modulates the innate and adaptive immune responses. In this study, we prepared high-purity bovine interferon gamma (BoIFN-γ) dimer protein using prokaryotic expression system and affinity chromatography. We subsequently investigated the effect of BoIFN-γ on BoHV-1 infection in Madin-Darby bovine kidney (MDBK) cells. The results showed that BoIFN-γ pre-treament not only decreased the production of BoHV-1 but also reduced the cytopathic effect of the virus. Differential gene expression profiles of BoHV-1 infected MDBK cells were then analysed through high-throughput RNA sequencing. The data showed that BoIFN-γ pre-treatment reduced lipid metabolism disorder and DNA damage caused by BoHV-1 infection. Furthermore, BoIFN-γ treatment upregulated the transcription of interferon regulatory transcription factors (IRF1 and GBP5) and interferon-stimulated genes (ISGs) of MDBK cells. Additionally, BoIFN-γ promotes expression of cellular protein involved in complement activation and coagulation cascades response as well as antigen processing and presentation process, while BoHV-1 infection dramatically downregulates transcription of these immune components including C3, C1r, C1s, PLAT, ITGB2, PROCR, BoLA, CD74, B2M, PA28, BoLA-DRA, and TAPBP. Collectively, our findings revealed that BoIFN-γ pre-treatment can improve host resistance to BoHV-1 infection and regulate transcription or expression of host protein associated with cellular metabolism and innate immune response. This provides insights into the development of prophylactic agents for prevention and control of BoHV-1 infection.

Transcriptomics and Metabolomics Analysis of the Ovaries of High and Low Egg Production Chickens

Simple Summary

The ovarian tissues of different breeds of hens during egg production were investigated through transcriptomics and metabolomics to provide a more comprehensive understanding of the molecular mechanisms of the ovary during egg production. Four genes involved in egg production were predicted by the transcriptome, including P2RX1, INHBB, VIPR2, and FABP3, and several close metabolites associated with reproduction were identified in the metabolome, including 17α-hydroxyprogesterone, iloprost, spermidine and adenosine. Correlation analysis of specific differential genes and differential metabolites identified important gene-metabolite pairs VIPR2–Spermidine and P2RX1–Spermidine in the reproductive process.

Abstract

Egg production is a pivotal indicator for evaluating the fertility of poultry, and the ovary is an essential organ for egg production and plays an indispensable role in poultry production and reproduction. In order to investigate different aspects of egg production mechanisms in different poultry, in this study we performed a metabolomic analysis of the transcriptomic combination of the ovaries of two chicken breeds, the high-production Ninghai indigenous chickens and the low-production Wuliangshan black-boned chickens, to analyze the biosynthesis and potential key genes and metabolic pathways in the ovaries during egg production. We predicted four genes in the transcriptomic that are associated with egg production, namely P2RX1, INHBB, VIPR2, and FABP3, and identified three important pathways during egg production, “Calcium signaling pathway”, “Neuroactive ligand–receptor interaction” and “Cytokine–cytokine receptor interaction”, respectively. In the metabolomic 149 significantly differential metabolites were identified, 99 in the negative model and 50 in the positive model, of which 17α-hydroxyprogesterone, iloprost, spermidine, and adenosine are important metabolites involved in reproduction. By integrating transcriptomics and metabolomics, the correlation between specific differential genes and differential metabolites identified important gene-metabolite pairs “VIPR2-Spermidine” and “P2RX1-Spermidine” in egg production. In conclusion, these data provide a better understanding of the molecular differences between the ovaries of low- and high-production hens and provide a theoretical basis for further studies on the mechanics of poultry egg production.

Expression of Oocyte Vitellogenesis Receptor Was Regulated by C/EBPα in Developing Follicle of Wanxi White Goose

Yolk precursor was synthesized under regulation of hormone secretion, while the mechanism of its incorporation into follicle is still unknown. The reproductive hormones, oocyte vitellogenesis receptor (OVR) expression at pre-, early-, peak- and ceased-laying period, and localization of Wanxi White goose were determined in this study. The results showed that the concentration of LH was lowest in serum at peak laying period compared to the other periods (p < 0.01). Moreover, the concentration of E2 was highest (p < 0.01) in serum at early laying period than that of other periods. Moreover, the gene expression level of OVR was highest at ceased laying period compared to other periods (p = 0.014) and was higher in developing follicles than other follicles (p < 0.01). The OVR was distributed in the granular cell layer and decreased with the maturation of follicles. Five transcription factors were predicted in the promoter of OVR, then were screened and verified by overexpression in granulosa cells. C/EBPα and MF3 significantly stimulated the expression of OVR. The combined overexpression of C/EBPα and OVR significantly stimulated the transportation of lipid from culture medium to cytoplasm. In conclusion, C/EBPα is the key transcription factor promoting OVR expression in goose follicle granulosa cells.

Lipidomics profiling of goose granulosa cell model of stearoyl-CoA desaturase function identifies a pattern of lipid droplets associated with follicle development

Background

Despite their important functions and nearly ubiquitous presence in cells, an understanding of the biology of intracellular lipid droplets (LDs) in goose follicle development remains limited. An integrated study of lipidomic and transcriptomic analyses was performed in a cellular model of stearoyl-CoA desaturase (SCD) function, to determine the effects of intracellular LDs on follicle development in geese.

Results

Numerous internalized LDs, which were generally spherical in shape, were dispersed throughout the cytoplasm of granulosa cells (GCs), as determined using confocal microscopy analysis, with altered SCD expression affecting LD content. GC lipidomic profiling showed that the majority of the differentially abundant lipid classes were glycerophospholipids, including PA, PC, PE, PG, PI, and PS, and glycerolipids, including DG and TG, which enriched glycerophospholipid, sphingolipid, and glycerolipid metabolisms. Furthermore, transcriptomics identified differentially expressed genes (DEGs), some of which were assigned to lipid-related Gene Ontology slim terms. More DEGs were assigned in the SCD-knockdown group than in the SCD-overexpression group. Integration of the significant differentially expressed genes and lipids based on pathway enrichment analysis identified potentially targetable pathways related to glycerolipid/glycerophospholipid metabolism.

Conclusions

This study demonstrated the importance of lipids in understanding follicle development, thus providing a potential foundation to decipher the underlying mechanisms of lipid-mediated follicle development.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13578-021-00604-6.