IL-33 regulates adipogenesis via Wnt/ß-catenin/PPAR-γ signaling pathway in preadipocytes.

Interleukin-33 (IL-33), an emerging cytokine within the IL-1 family, assumes a pivotal function in the control of obesity. However, the specific mechanism of its regulation of obesity formation remains unclear. In this study, we found that the expression level of IL-33 increased in visceral adipose tissue in mice fed with a high-fat diet (HFD) compared with that in mice fed with a normal diet (ND). In vitro, we also found the expression level of IL-33 was upregulated during the adipogenesis of 3T3-L1 cells. Functional test results showed that knockdown of IL-33 in 3T3-L1 cells differentiation could promote the accumulation of lipid droplets, the content of triglyceride and the expression of adipogenic-related genes (i.e. PPAR-γ, C/EBPα, FABP4, LPL, Adipoq and CD36). In contrast, overexpression of IL-33 inhibits adipogenic differentiation. Meanwhile, the above tests were repeated after over-differentiation of 3T3-L1 cells induced by oleic acid, and the results showed that IL-33 played a more significant role in the regulation of adipogenesis. To explore the mechanism, transcriptome sequencing was performed and results showed that IL-33 regulated the PPAR signaling pathway in 3T3-L1 cells. Further, Western blot and confocal microscopy showed that the inhibition of IL-33 could promote PPAR-γ expression by inhibiting the Wnt/ß-catenin signal in 3T3-L1 cells. This study demonstrated that IL-33 was an important regulator of preadipocyte differentiation and inhibited adipogenesis by regulating the Wnt/ß-catenin/PPAR-γ signaling pathway, which provided a new insight for further research on IL-33 as a new intervention target for metabolic disorders.

Effect of immunization against OPN5 on the reproductive performance in Shan Partridge ducks under different photoperiods.

Photoperiod is an important environmental factor that influences seasonal reproduction behavior in birds. Birds translate photoperiodic information into neuroendocrine signals through deep brain photoreceptors (DBPs). OPN5 has been considered candidate DBPs involved in regulating seasonal reproduction in birds. We found that OPN5 could mediate light to regulate the follicle development in ducks. In this study, we further verified the effect of OPN5 on follicular development in Shan Partridge ducks by immunizing against the extracellular domain (ECD) of OPN5. We investigated the specific regulatory mechanism of photoperiod mediated by OPN5 on the reproductive activity of ducks. The trial randomly divided 120 Shan Partridge ducks into 3 groups with different treatments: the immunization of OPN5 group was done at d0, d15, d30, and d40 with 1 mL of vaccine containing OPN5 protein (thus containing 1, 1, 0.5, and 0.5 mg of OPN5-KLH protein), and the control group (CS and CL groups) was injected at the same time with the same dose of OPN5-uncontained blank vaccine. The group of CS (900 lux), OPN5 (600 lux), and CL (600 lux) lasted for 40 d in 12 L:12 D photoperiods, respectively. Then, the groups of CS, OPN5, and CL subsequently received 12 L:12 D, 12 L:12 D, and 17 L:7 D light treatments for 33 d, respectively. The ducks were caged in 3 constant rooms with the same feeding conditions for each group, free water, and limited feeding (150 g per duck each day). Duck serum and tissue samples were collected at d 40, d 62, and d 73 (n = 12). It was found that before prolonged light, the group of immunization (group OPN5) and the group of strong light intensity (group CS) were higher than the group of CL in egg production. Subsequent to prolonged light, the group CL in egg production rose about the same as the group immunization, while the strong light group (group CS) was lower. Group OPN5 increased the ovarian index of ducks, and both the immunization of group OPN5 and group CL (extended light) increased the thickness of the granular layer and promoted the secretion of E2, P4, LH, and PRL hormones. Compared with group CS, group CL and OPN5 increased the mRNA level and protein expression of OPN5 in the hypothalamus on d 62 and d 73 (P < 0.05). The gene or protein expression patterns of GnRH, TRH, TSHß, DIO2, THRß, VIP, and PRL were positively correlated with OPN5, whereas the gene expression patterns of GnIH and DIO3 were negatively correlated with OPN5. The results showed that immunization against OPN5 could activate the corresponding transmembrane receptors to promote the expression of OPN5, up-regulate the expression of TSHß and DIO2, and then regulate the HPG axis-related genes to facilitate the follicular development of Shan Partridge ducks. In addition, in this experiment, prolonging the photoperiod or enhancing the light intensity could also enhance follicle development, but the effect was not as significant as immunizing against OPN5. Our results will offer beneficial data and more supportive shreds of evidence in favor of elucidating the role of OPN5 in relation to photoperiods and reproduction.

Polysaccharide of Atractylodes macrocephala Koidz alleviates LPS-induced proliferation, differentiation inhibition and excessive apoptosis in chicken embryonic myogenic cells.

BACKGROUND: Lipopolysaccharide (LPS) can induce systemic inflammation and affect the growth and development of poultry. As a kind of traditional Chinese medicine, polysaccharide of Atractylodes macrocephala Koidz (PAMK) can effectively improve the growth performance of animals and improve the immunity of animal bodies. OBJECTIVES: The purpose of this study was to investigate the effects of PAMK on LPS-induced inflammatory response, proliferation, differentiation and apoptosis of chicken embryonic myogenic cells. METHODS: We used chicken embryonic myogenic cells as a model by detecting EdU/MYHC immunofluorescence, the expression of inflammation, proliferation, differentiation-related genes and proteins and the number of apoptotic cells in the condition of adding LPS, PAMK, belnacasan (an inhibitor of Caspase1) or their combinations. RESULTS: The results showed that LPS stimulation increased the expression of inflammatory factors, inhibited proliferation and differentiation, and excessive apoptosis in chicken embryonic myogenic cells, and PAMK alleviated these adverse effects induced by LPS. After the addition of belnacasan (inhibitor of Caspase1), apoptosis in myogenic cells was inhibited, and therefore, the number of apoptotic cells and the expression of pro-apoptotic genes Caspase1 and Caspase3 were increased. In addition, belnacasan inhibited the increased expression of inflammatory factors, inhibited proliferation, differentiation and excessive apoptosis in chicken embryonic myogenic cells induced by LPS. CONCLUSIONS: This study provides a theoretical basis for further exploring the mechanism of action of PAMK and exogenous LPS on chicken embryonic myogenic cells and lays the foundation for the development and application of green feed additives in animal husbandry industry.

Effects of stocking density on the homeostasis of uric acid and related liver and kidney functions in ducks.

Objective: Stocking density (SD) is an important issue in the poultry industry, which is related to the production performance, intestinal health and immune status. In the present study, the effects of SD on the metabolism and homeostasis of uric acid as well as the related functions of the liver and kidney in ducks were examined. Methods: A total of 360 healthy 56-day-old Shan-ma ducks were randomly divided into the low stocking density (LSD; n = 60, density = 5 birds/m2), medium stocking density (MSD; n = 120, density = 10 birds/m2) and high stocking density groups (HSD; n = 180, density = 15 birds/m2). Samples were collected in the 3rd, 6th and 9th weeks of the experiment for analysis. Results: The serum levels of uric acid, LPS and inflammatory cytokines (IL-1ß, IL-8 and TNF-α) were increased significantly in the HSD group. Serious histopathological lesions could be seen in both the livers and kidneys in the HSD group in the 9th week. The mRNA expression levels of inflammatory cytokines (IL-8 and TNF-α) and related pathway components (TLR-4, MyD88 and NF-κB) were increased significantly in both the livers and kidneys in the HSD group. The mRNA expression levels of enzymes (ADA, XOD, PRPPAT and PRPS1) related to the synthesis of uric acid increased significantly in the livers in the HSD group. However, the mRNA expression level of SLC2A9, which plays an important role in the excretion of uric acid by the kidney, was decreased significantly in the kidneys in the HSD group. Conclusion: These results indicated that a higher SD could cause tissue inflammatory lesions in the liver and kidney and subsequently affect the metabolism and homeostasis of uric acid, and is helpful for guiding decisions related to the breeding and production of ducks.

Transcriptome and lipidome integration unveils mechanisms of fatty liver formation in Shitou geese.

Geese evolved from migratory birds, and when they consume excessive high-energy feed, glucose is converted into triglycerides. A large amount of triglyceride deposition can induce incomplete oxidation of fatty acids, leading to lipid accumulation in the liver and the subsequent formation of fatty liver. In the Chaoshan region of Guangdong, China, Shitou geese develop a unique form of fatty liver through 24 h overfeeding of brown rice. To investigate the mechanisms underlying the formation of fatty liver in Shitou geese, we collected liver samples from normally fed and overfed geese. The results showed that the liver size in the treatment group was significantly larger, weighing 3.5 times more than that in the control group. Extensive infiltration of lipid droplets was observed in the liver upon staining of tissue sections. Biochemical analysis revealed that compared to the control group, the treatment group showed significantly elevated levels of total cholesterol (T-CHO), triglycerides (TG), and glycogen in the liver. However, no significant differences were observed in the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), which are common indicators of liver damage. Furthermore, we performed a combined transcriptomic and lipidomic analysis of the liver samples and identified 1,510 differentially expressed genes (DEGs) and 1,559 significantly differentially abundant metabolites (SDMs). The enrichment analysis of the DEGs revealed their enrichment in metabolic pathways, cellular process-related signaling pathways, and specific lipid metabolism pathways. We also conducted KEGG enrichment analysis of the SDMs and compared them with the enriched signaling pathways obtained from the DEGs. In this study, we identified 3 key signaling pathways involved in the formation of fatty liver in Shitou geese, namely, the biosynthesis of unsaturated fatty acids, glycerol lipid metabolism, and glycerophospholipid metabolism. In these pathways, genes such as glycerol-3-phosphate acyltransferase, mitochondrial (GPAM), 1-acylglycerol-3-phosphate O-acyltransferase 2 (AGPAT2), diacylglycerol O-acyltransferase 2 (DGAT2), lipase, endothelial (LIPG), lipoprotein lipase (LPL), phospholipase D family member 4 (PLD4), and phospholipase A2 group IVF (PLA2G4F) may regulate the synthesis of metabolites, including triacylglycerol (TG), phosphatidate (PA), 1,2-diglyceride (DG), phosphatidylethanolamine (PE), and phosphatidylcholine (PC). These genes and metabolites may play a predominant role in the development of fatty liver, ultimately promoting the accumulation of TG in the liver and leading to the progression of fatty liver.

Drp1 regulated PINK1-dependent mitophagy protected duck follicular granulosa cells from acute heat stress injury.

The mitochondrial quality control system is crucial in maintaining cellular homeostasis during environmental stress. Granulosa cells are the main cells secreting steroid hormones, and mitochondria are the key organelles for steroid hormone synthesis. The impact of the mitochondrial quality control system on granulosa cells' steroid hormone synthesis and survival under heat stress is still unclear. Here, we showed that acute heat stress induces mitochondrial damage and significantly increases the number of mitophagy-like vesicles in the cytoplasm of duck ovary granulosa cells at the ultra-structural level. Meanwhile, we also found heat stress significantly increased mitochondrial fission and mitophagy-related protein expression levels both in vivo and in vitro. Furthermore, by confocal fluorescence analysis, we discovered that LC3 was distributed spot-like manner near the nucleus in the heat treatment group, and the LC3 spots and lysosomes were colocalized with Mito-Tracker in the heat treatment group. We further detected the mitophagy-related protein in the cytoplasm and mitochondria, respectively. Results showed that the PINK1 protein was significantly increased both in cytoplasm and mitochondria, while the LC3-Ⅱ/LC3-Ⅰ ratio increase only occurred in mitochondrial. In addition, the autophagy protein induced by acute heat treatment was effectively inhibited by the mitophagy inhibitor CysA. Finally, we demonstrated that the alteration of cellular mitophagy by siRNA interference with Drp1 and PINK1 inhibited the steroid synthesis of granulosa cells and increased cell apoptosis. Study provides strong evidence that the Drp1 regulated PINK1-dependent mitophagy pathway protects follicular granulosa cells from acute heat stress-induced injury.

Association between co-infection with Chlamydia trachomatis or Mycoplasma genitalium and cervical lesions in HPV-positive population in Hunan, China: a cross-sectional study.

OBJECTIVES: The aim of this study was to determine the prevalence of Chlamydia trachomatis (CT) and Mycoplasma genitalium (MG) among HPV-positive women undergoing colposcopy at the Second Xiangya Hospital of Central South University, Hunan, China. Additionally, we aimed to assess the impact of C. trachomatis or M. genitalium co-infection with HPV on the severity of cervical lesions. METHODS: We collected HPV data, cervical cytology results, and demographic information from 439 women attending colposcopy. Cervical swabs were obtained for simultaneous amplification testing (SAT) of C. trachomatis and M. genitalium. Multivariate logistic regression analyses were performed to examine the association between sexually transmitted pathogens and cervical lesions. RESULTS: Among the participants, C. trachomatis was detected in 17 (3.87%) individuals, and M. genitalium in 16 (3.64%) individuals. There was no co-infection of C. trachomatis and M. genitalium. The highest prevalence of M. genitalium was observed in women aged 19-30 years (10.20%; 95% CI, 1.41-18.99%), with a subsequent decline in prevalence with increasing age (Ptrend = 0.014). The most common HPV subtype in our study was HPV52 (30.79%), followed by HPV16 (18.62%), HPV58 (16.95%), and HPV53 (10.02%). Infection with HPV16 (OR = 3.43, 95% CI, 2.13-5.53), HPV31 (OR = 3.70, 95% CI, 1.44-9.50), and HPV33 (OR = 3.71, 95% CI, 1.43-9.67) was associated with an increased severity of cervical lesions, while HPV53 infection was not likely to lead to advanced cervical lesions (OR = 0.45, 95% CI, 0.23-0.89). The leukocyte level in vaginal secretions (P = 0.042) and cervical cytology results (P < 0.001) showed associations with the degree of cervical lesions. However, there was no significant association between C. trachomatis or M. genitalium infection and the severity of cervical lesions, nor with their co-infection with HPV16. CONCLUSIONS: There was no correlation between co-infection of Chlamydia trachomatis or Mycoplasma genitalium and the degree of cervical lesions in HPV-positive population in Hunan, China. Our findings emphasized the need to pay more attention to M. genitalium infection among young women. Increased levels of leukocytes in vaginal secretions may be linked to cervical lesions. HPV16, HPV31, and HPV33 in Hunan province, China, may exhibit higher cervical pathogenicity.

Endocrine and molecular regulation mechanisms of follicular development and egg-laying in quails under different photoperiods.

Photoperiod is a key environmental factor in regulating bird reproduction and induces neuroendocrine changes through the hypothalamic-pituitary-gonadal (HPG) axis. OPN5, as a deep-brain photoreceptor, transmits light signals to regulate follicular development through TSH-DIO2/DIO3. However, the mechanism among OPN5, TSH-DIO2/DIO3, and VIP/PRL in the HPG axis underlying the photoperiodic regulation of bird reproduction is unclear. In this study, 72 laying quails with 8-week-old were randomly divided into the long-day (LD) group [16 light (L): 8 dark (D)] and the short-day (SD) group (8 L:16 D), and then samples were collected on d 1, d 11, d 22, and d 36 of the experiment. The results showed that compared with the LD group, the SD group significantly inhibited follicular development (P < 0.05), decreased the P4, E2, LH, and PRL in serum (P < 0.05), downregulated the expression of GnRHR, VIP, PRL, OPN5, DIO2, and LHß (P < 0.05), reduced the expression of GnRH and TSHß (P > 0.05), and promoted DIO3, GnIH gene expression (P < 0.01). The short photoperiod downregulates OPN5, TSHß, and DIO2 and upregulates DIO3 expression to regulate the GnRH/GnIH system. The downregulation of GnRHR and upregulation of GnIH resulted in a decrease in LH secretion, which withdrew the gonadotropic effects on ovarian follicles development. Slow down of follicular development and egg laying may also arise from lack of PRL potentiation to small follicle development under short days.

DNA Demethylation of Myogenic Genes May Contribute to Embryonic Leg Muscle Development Differences between Wuzong and Shitou Geese.

Skeletal muscle development from embryonic stages to hatching is critical for poultry muscle growth, during which DNA methylation plays a vital role. However, it is not yet clear how DNA methylation affects early embryonic muscle development between goose breeds of different body size. In this study, whole genome bisulfite sequencing (WGBS) was conducted on leg muscle tissue from Wuzong (WZE) and Shitou (STE) geese on embryonic day 15 (E15), E23, and post-hatch day 1. It was found that at E23, the embryonic leg muscle development of STE was more intense than that of WZE. A negative correlation was found between gene expression and DNA methylation around transcription start sites (TSSs), while a positive correlation was observed in the gene body near TTSs. It was also possible that earlier demethylation of myogenic genes around TSSs contributes to their earlier expression in WZE. Using pyrosequencing to analyze DNA methylation patterns of promoter regions, we also found that earlier demethylation of the MyoD1 promoter in WZE contributed to its earlier expression. This study reveals that DNA demethylation of myogenic genes may contribute to embryonic leg muscle development differences between Wuzong and Shitou geese.

Transcriptome analysis reveals a potential regulatory mechanism of the lnc-5423.6/IGFBP5 axis in the early stages of mouse thymic involution.

Age-related thymic involution is one of the significant reasons for induced immunity decline. Recent evidence has indicated that lncRNAs are widely involved in regulating organ development. However, the lncRNA expression profiles in mouse thymic involution have not been reported. In this study, we collect mouse thymus at the ages of 1 month, 3 months, and 6 months for sequencing to observe the lncRNA and gene expression profiles in the early stages of thymic involution. Through bioinformatics analysis, a triple regulatory network of lncRNA-miRNA-mRNA that contains 29 lncRNAs, 145 miRNAs and 12 mRNAs that may be related to thymic involution is identified. Among them, IGFBP5 can reduce the viability, inhibit proliferation and promote apoptosis of mouse medullary thymic epithelial cell line 1 (MTEC1) cells through the p53 signaling pathway. In addition, miR-193b-3p can alleviate MTEC1 cell apoptosis by targeting IGFBP5. Notably, lnc-5423.6 can act as a molecular sponge of miR-193b-3p to regulate the expression of IGFBP5. In summary, lnc-5423.6 enhances the expression of IGFBP5 by adsorption of miR-193b-3p, thereby promoting MTEC1 cell apoptosis.

GSDMD-mediated pyroptosis restrains intracellular Chlamydia trachomatis growth in macrophages.

Pyroptosis, a type of programmed necrosis associated with inflammatory, is a host defense mechanism against microbial infections. Although Chlamydia has been shown to induce pyroptosis, whether pyroptosis directly impacts the growth of Chlamydia has not been demonstrated. In this study, we found that C. trachomatis L2 infection of the mouse macrophage RAW 264.7 cells induced pyroptosis by monitoring the ultrastructural changes under transmission electron microscopy and the release of LDH and IL-1ß. More importantly, this C. trachomatis-triggered pyroptosis with activation of caspase-1 and caspase-11 was also accompanied by gasdermin D (GSDMD) activation. Suppression of these two inflammatory caspases inhibited GSDMD activation. Interestingly, the C. trachomatis-triggered pyroptosis significantly inhibited the intracellular growth of C. trachomatis since inactivation of either GSDMD or caspase-1/11 significantly rescued infectious C. trachomatis yields, which suggests pyroptosis response can be utilized as an intrinsic mechanism to restrict C. trachomatis intracellular infection in addition to the well- documented extrinsic mechanisms by recruiting and enhancing inflammatory responses. This study may reveal novel targets for attenuating C. trachomatis infectivity and/or pathogenicity.

Polysaccharide of Atractylodes macrocephala Koidz(PAMK) protects against DEHP-induced apoptosis in grass carp hepatocytes.

Di(2-ethylhexyl) phthalate (DEHP) is a new environmental pollutant, which is widely used in plastic additives. DEHP and its metabolites pollute surface water and threaten the survival of fish. In order to investigate the mechanism of DEHP-induced apoptosis on grass carp hepatocytes, we treated grass carp hepatocytes with DEHP, and selected Atractylodes macrocephala Koidz (PAMK) to study its inhibitory effect on DEHP. The results showed that after DEHP exposure, apoptosis related proteins expression were increased significantly, leading to hepatocytes apoptosis. Moreover, AO/EB staining and Hoechst staining also showed that the number of apoptotic cells increased after DEHP exposure. It should be noted that PAMK simultaneous treatment could alleviate apoptosis induced by DEHP. The innovation of this study is that the application of Chinese herbal medicine (PAMK) to antagonize the damage of DEHP in fish was investigated for the first time. This study indicated that traditional Chinese medicine can also be used in fish production to reduce the accumulation of food-derived drugs.

Polysaccharide of Atractylodes macrocephala Koidz alleviate lipopolysaccharide-induced liver injury in goslings via the p53 and FOXO pathways.

Lipopolysaccharide (LPS) can affect the immune system of geese by inducing liver injury. The polysaccharide of Atractylodes macrocephala Koidz (PAMK) have obvious immune-enhancing effects. Accordingly, this experiment investigated the effect of PAMK on LPS-induced liver injury in goslings. Two hundred 1-day-old goslings were randomly divided into the control group, LPS group, PAMK group, and PAMK+ LPS group, and the PAMK and PAMK+ LPS groups were fed the basal diet with 400 mg/kg PAMK, while the control and LPS groups were fed the basal diet. On D 21, 23, and 25 of the formal trial, the goslings in the LPS and PAMK+LPS groups were injected intraperitoneally with 2 mg/kg LPS, and goslings in the control and PAMK groups were injected intraperitoneally with the same amount of saline. Livers were collected on D 25. HE-stained sections showed that PAMK could effectively alleviate the LPS-induced indistinct hepatic cord structure, loss of cytoplasmic contents of hepatocytes, and dilatation of hepatic sinusoids. The biochemical parameters of liver tissues showed that PAMK could alleviate the LPS-induced upregulation of alanine aminotransferase and aspartate aminotransferase. To further investigate the mechanism of the mitigating effect of PAMK on LPS-induced injury, livers from the LPS and PAMK+LPS groups were selected for transcriptome sequencing. The sequencing results showed that there were 406 differentially expressed genes (DEGs) in the livers of LPS and PAMK+LPS goslings, of which 242 upregulated and 164 downregulated. The Kyoto Encyclopedia of Genes and Genome (KEGG) analysis showed that DEGs were significantly enriched in immune signal transduction, cell cycle, and cell metabolism. Besides, protein‒protein interaction analysis showed that 129 DEGs were associated with each other, including 7 DEGs enriched in the p53 and FOXO signaling pathway. In conclusion, PAMK may alleviate LPS-induced liver injury in gosling through the p53 and FOXO signaling pathway. These results provide a basis for further development of PAMK as an immunomodulator.

Surveillance of the Antimicrobial Susceptibility and Molecular Characteristics of Neisseria gonorrhoeae Isolates Collected in Changsha, China from 2016 to 2021.

Antibiotic treatment is critical for individuals infected with gonorrhea and preventing disease transmission. This study aimed to analyze the antimicrobial susceptibility and molecular epidemiological characteristics of Neisseria gonorrhoeae isolates in Changsha, China. A total of 271 N.gonorrhoeae isolates collected from the clinical laboratories of two hospitals between 2016 and 2021 were analyzed for antimicrobial susceptibility using the agar dilution method. N. gonorrhoeae multi-antigen sequence typing (NG-MAST) was conducted for genotyping, and phylogenetic analysis was performed using the porB and tbpB sequences. The results showed that antimicrobial resistance against ciprofloxacin, tetracycline, and penicillin was high, and these drugs are no longer recommended for the treatment of gonorrhea. All isolates were susceptible to spectinomycin. However, in 2016-2021, a total of 15 (5.5%) ceftriaxone (CRO)-resistant strains and 31 (11.4%) isolates with decreased susceptibility to CRO were found, and the resistance rate to azithromycin had reached 7.1% in 2016-2017. Epidemiologically, the mosaic penA allele was identified in all CRO-resistant isolates. Based on NG-MAST, ST5061 was the most prevalent ST. Phylogenetic analysis suggested that the resistant isolates did not cluster independently. Despite focus on the local situation, this study raises the need for better gonorrhea medication and highlights that CRO may not be adequate as first-line treatment for gonorrhea in Changsha.

Polysaccharide of Atractylodes macrocephala Koidz alleviate lipopolysaccharide-stimulated liver inflammation injury of goslings through miR-223/NLRP3 axis.

Lipopolysaccharide (LPS) infection could cause severe liver inflammation and lead to liver damage, even death. Previous studies have shown that polysaccharide of Atractylodes macrocephala Koidz (PAMK) could protect liver from inflammation caused by LPS in mice. However, whether PAMK could alleviate liver inflammatory injury in other animals with LPS is still unknown. For evaluating whether PAMK could alleviate liver inflammatory injury in goslings with LPS, a total of 80 healthy 1-day old Magang goslings were randomly divided into 4 groups (control group, PAMK group, LPS group, and PAMK+LPS group). Goslings in control group and LPS group were fed with basal diet, and goslings in PAMK group and PAMK+LPS group were fed basal diet supplemented with 400 mg/kg PAMK to the end of trial. On 24 d of age, goslings in the control group and PAMK group were intraperitoneal injected 0.5 mL normal saline, and goslings in LPS and PAMK+LPS groups were intraperitoneal injected with LPS at 5 mg/kg BW. The serum and liver samples were collected for further analysis after treatment of LPS at 6, 12, 24, and 48 h. Furthermore, the hepatocytes were extracted from goose embryo to measure the expression of the key genes of miR-223/NLRP3 axis. The results showed that PAMK pretreatment could maintain normal cell morphology of liver, alleviate the enhanced levels of biochemical indexes ALT and AST, decrease the levels of IL-1ß and IL-18, increase the relative mRNA expression of miR-223, and decrease the expression of NLRP3, Caspase-1, and cleaved Caspase-1 in liver and hepatocytes of goslings induced by LPS. These results indicated that PAMK could relieve inflammatory liver tissue damage after LPS treatment and downregulate the level of inflammation factors via miR-223/NLRP3 axis, thus playing a liver protective role in liver inflammation injury in goslings.

Characterization of circular RNA expression profiles in the age-related thymic involution of Magang goose.

The thymus is a vital immune organ, but its function gradually declines with age. Circular RNAs (circRNAs) are related to the development of tissues and organs. In this study, bioinformatics analysis showed that 1329, 755, and 417 circRNAs were differentially expressed between the comparison groups of 6-month age (M6) and 20-embryo age (E20), 3-day post-hatch (P3), and 3-month age (M3) Magang geese, respectively. Among them, 167 circRNAs were differentially co-expressed between thymic development (E20, P3, and M3) and involution (M6). Functional analysis showed significant enrichment of phosphorylation and positive regulation of GTPase activity. Furthermore, pathway analysis has shown that glycerolipid metabolism and the Wnt signaling pathway are critical pathways in the thymic involution process. Finally, we constructed the competitive endogenous RNA (ceRNA) network. The results of this study suggest that circRNAs may be involved in the age-related thymic involution of the Magang goose.

Non-coding RNA regulation of Magang geese skeletal muscle maturation via the MAPK signaling pathway.

Skeletal muscle is a critical component of goose meat and a significant economic trait of geese. The regulatory roles of miRNAs and lncRNAs in the maturation stage of goose skeletal muscle are still unclear. Therefore, this study conducted experiments on the leg muscles of Magang geese at two stages: 3-day post-hatch (P3) and 3 months (M3). Morphological observations revealed that from P3 to M3, muscle fibers mainly underwent hypertrophy and maturation. The muscle fibers became thicker, nuclear density decreased, and nuclei moved towards the fiber edges. Additionally, this study analyzed the expression profiles of lncRNAs, miRNAs, and mRNAs during the skeletal muscle fiber maturation stage, identifying 1,949 differentially expressed mRNAs (DEMs), 21 differentially expressed miRNAs (DEMIs), and 172 differentially expressed lncRNAs (DELs). Furthermore, we performed enrichment analyses on DEMs, cis-regulatory genes of DELs, and target DEMs of DEMIs, revealing significant enrichment of signaling pathways including MAPK, PPAR, and mTOR signaling pathways. Among these, the MAPK signaling pathway was the only pathway enriched across all three types of differentially expressed RNAs, indicating its potentially more significant role in skeletal muscle maturation. Finally, this study integrated the targeting relationships between DELs, DEMs, and DEMIs from these two stages to construct a ceRNA regulatory network. These findings unveil the potential functions and mechanisms of lncRNAs and miRNAs in the growth and development of goose skeletal muscle and provide valuable references for further exploration of the mechanism underlying the maturation of Magang geese leg muscle.

Polysaccharide of Atractylodes macrocephala Koidz Alleviates Cyclophosphamide-Induced Thymus Ferroptosis in Gosling.

The present study aimed to explore the mechanism by which PAMK alleviates cyclophosphamide (CTX)-induced ferroptosis in thymocytes. One-day-old goslings were divided into four groups (10 goslings/group). The CON and CTX groups were fed a basic diet. The PAMK and CTX + PAMK groups were fed the basic diet mixed with PAMK (400 mg/kg). Moreover, the CTX and CTX + PAMK groups were given a daily injection of 40 mg/kg BW of CTX (at 19, 20, and 21 days of age). On the other hand, the CON and PAMK groups were given 0.5 mL of sterilized saline into the leg muscle (at 19, 20, and 21 days of age). The goslings were fed for 28 days. The ferroptosis pathway was enriched in transcriptome sequencing. Compared to the CON group, the thymus in the CTX group underwent injury, and the mitochondria of thymocytes showed features of ferroptosis. PAMK treatment alleviated ferroptosis in thymocytes and thymus injury, and CTX-induced elevated levels of oxidative stress and iron content restored GPX4 protein expression (p < 0.05) and inhibited the CTX-induced activation of the ferroptosis pathway (p < 0.05). Conclusively, PAMK could reduce thymus injury by alleviating CTX-induced thymocyte ferroptosis in gosling to alleviate the immunosuppression caused by CTX in the organism.

Expression of GnIH and its effects on follicle development and steroidogenesis in quail ovaries under different photoperiods.

Photoperiod is an important environmental factor that influence seasonal reproduction behavior in bird and GnIH can play a function in this process through the reproductive axis, and some studies suggest that GnIH may have a direct role at the gonadal level. To investigate the expression of GnIH and its effects on follicle development and steroidogenesis in quail ovaries under different photoperiods, 72 healthy laying quails of 8-wk-old were randomly divided into long day (LD) group [16 light (L): 8 dark (D)] (n = 36) and short day (SD) group (8L:16D) (n = 36). Samples were collected from each group on d1, d11, d22, and d36 of the experiment. The result showed that short day treatment upregulated the level of GnIH in the gonads (P < 0.05), decreased the expression level of CYP19A1,3ß-HSD, StAR, LHR, and FSHR and increased the expression level of AMH, AMHR2, GDF9, and BMP15 to inhibit follicle development and ovulation, thus affecting the egg production performance of quails. In vitro culture of quail granulosa cells and treatment with different concentrations of GnIH (0, 1, 10, and 100 ng/mL) for 24 h. Result showed that GnIH inhibited the levels of FSHR, LHR, and steroid synthesis pathways in granulosa cells, upregulated the levels of AMHR2, GDF9, and BMP15. The results suggest that the inhibition of follicle development and reduced egg production in quail by short day treatment is due to GnIH acting at the gonadal level, and GnIH affected the steroid synthesis by inhibiting gonadotropin receptors.

Lipopolysaccharide Promotes the Proliferation and Differentiation of Goose Embryonic Myoblasts by Promoting Cytokine Expression and Appropriate Apoptosis Processes.

Lipopolysaccharide (LPS) can trigger a series of immune reactions, leading to the occurrence of disease and a decrease in the growth performance of geese. However, the mechanisms of LPS in geese muscle development have not been reported. This study aimed to investigate the effects and mechanisms of LPS on proliferation and differentiation of goose embryonic myoblasts. Embelin and belnacasan combined with LPS were used to explore these effects. Our results demonstrated that LPS significantly induced inflammatory cytokine production in both proliferation and differentiation stages. LPS and embelin treatment significantly improved the proliferation ability (p < 0.05), while LPS reduced the differentiation ability of goose embryonic myoblasts. By adding embelin, the differentiation ability of myoblasts was enhanced, while by adding belnacasan, LPS treatment led to a lower differentiation ability. Combined with the correlation of the expression levels of myogenic, cell cycle, and inflammatory-related genes and proteins, it is speculated that one of the reason for the decrease of differentiation ability of goose embryo myoblasts induced by LPS is the increase of the expression levels of pro-inflammatory factors. Moreover, LPS, embelin and belnacasan, and LPS treatments could significantly increase the apoptosis rate of goose embryonic myoblasts. Taken together, these findings suggest that LPS promotes the proliferation and differentiation of goose embryonic myoblasts by promoting cytokine expression and appropriate apoptosis processes. These findings lay a foundation for the study of the mechanisms of LPS in goose muscle development.