• Animal Bioscience
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• v.37 no.8
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• pp.1345-1354
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• 2024

Objective: The objective of this study was to identify candidate genes that play important roles in skeletal muscle development in ducks. Methods: In this study, we investigated the transcriptional sequencing of embryonic pectoral muscles from two specialized lines: Liancheng white ducks (female) and Cherry valley ducks (male) hybrid Line A (LCA) and Line C (LCC) ducks. In addition, prediction of target genes for the differentially expressed mRNAs was conducted and the enriched gene ontology (GO) terms and Kyoto encyclopedia of genes and genomes signaling pathways were further analyzed. Finally, a protein-to-protein interaction network was analyzed by using the target genes to gain insights into their potential functional association. Results: A total of 1,428 differentially expressed genes (DEGs) with 762 being up-regulated genes and 666 being down-regulated genes in pectoral muscle of LCA and LCC ducks identified by RNA-seq (p<0.05). Meanwhile, 23 GO terms in the down-regulated genes and 75 GO terms in up-regulated genes were significantly enriched (p<0.05). Furthermore, the top 5 most enriched pathways were ECM-receptor interaction, fatty acid degradation, pyruvate degradation, PPAR signaling pathway, and glycolysis/gluconeogenesis. Finally, the candidate genes including integrin b3 (Itgb3), pyruvate kinase M1/2 (Pkm), insulin-like growth factor 1 (Igf1), glucose-6-phosphate isomerase (Gpi), GABA type A receptor-associated protein-like 1 (Gabarapl1), and thyroid hormone receptor beta (Thrb) showed the most expression difference, and then were selected to verification by quantitative real-time polymerase chain reaction (qRT-PCR). The result of qRT-PCR was consistent with that of transcriptome sequencing. Conclusion: This study provided information of molecular mechanisms underlying the developmental differences in skeletal muscles between specialized duck lines.

• IMMUNE NETWORK
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• v.5 no.2
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• pp.78-88
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• 2005

Background: Collagen-induced arthritis (CIA) in mice is animal model of autoimmune disease known as rheumatic arthritis in human. We investigated CII-specific CD4+ T cell receptor usage in CIA mice. Methods: In CIA model, draining lymph node (dLN) CD4+ T cells and splenocytes at $3^{rd},\;5^{th},\;8^{th}$ week, we investigated CII-specific T cell proliferation, production of IL-17, IFN-${\gamma}$, TNF-${\alpha}$, IL-4 and IL-10. And we also performed anti-CII IgG Ab measurements in serum level, TCRV ${\beta}$ usage and T cell clonality with RT-PCR-SSCP analysis. Also, we performed proliferative response against CII when CII-specific T cell subset is deleted. Results: CIA mice showed more increase in the serum level of anti-CII IgG than normal mice after induction of arthritis. And the level of anti-CII IgG2a in CIA mice was increased after $3^{rd}$ week after primary immunization, while anti-CII IgG1 was decreased. Draining LN CD4+ T cells have proliferated against CII stimulation at $3^{rd}$ week after $1^{st}$immunization. CD4+T cells derived from dLN of CIA mice produced proinflammatory cytokine IFN-${\gamma}$, IL-17 etc. Draining LN CD4 T cells of CIA presented higher proportion of CD4+V ${\beta}3$+subset compared to those of normal mice at $3^{rd}$ week after $1^{st}$ immunization, and they were increased in proportion by CII stimulation. Draining LN CD4+ T cells without TCRV ${\beta}3+/V{\beta}8.1/8.2+/V{\beta}$10b+cells were not responsive against CII stimulation. But, CII-reactive response of TCRV ${\beta}3-/V{\beta}8.1/8.2-/V{\beta}$10b- T cells was recovered when $V{\beta}3+$ T cells were added in culture. Conclusion: Our results indicate that CD4+$V{\beta}3+$ T cells are selectively expanded in dLN of CIA mice, and their recovery upon CII re-stimulation in vitro, as well as the production Th1-type cytokines, may play pivotal role in CIA pathogenesis.

• Journal of Nutrition and Health
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• v.56 no.6
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• pp.602-614
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• 2023

Purpose: The balance between synthesis and degradation of proteins plays a critical role in the maintenance of skeletal muscle mass. Mitochondrial dysfunction has been closely associated with skeletal muscle atrophy caused by aging, cancer, and chemotherapy. Polygalacin D is a saponin derivative isolated from Platycodon grandiflorum (Jacq.) A. DC. This study aimed to investigate the effects of polygalacin D on myoblast differentiation and muscle atrophy in association with mitochondrial function in in vitro and in zebrafish models in vivo. Methods: C2C12 myoblasts were cultured in differentiation media containing different concentrations of polygalacin D, followed by the immunostaining of the myotubes with myosin heavy chain (MHC). The mRNA expression of markers related to myogenesis, muscle atrophy, and mitochondrial function was determined by real-time quantitative reverse transcription polymerase chain reaction. Wild type AB^* zebrafish (Danio rerio) embryos were treated with 5-fluorouracil, leucovorin, and irinotecan (FOLFIRI) with or without polygalacin D, and immunostained to detect slow and fast types of muscle fibers. The Tg(Xla.Eef1a1:mitoEGFP) zebrafish expressing mitochondria-targeted green fluorescent protein was used to monitor mitochondrial morphology. Results: The exposure of C2C12 myotubes to 0.1 ng/mL of polygalacin D increased the formation of MHC-positive multinucleated myotubes (≥ 8 nuclei) compared with the control. Polygalacin D significantly increased the expression of MHC isoforms (Myh1, Myh2, Myh4, and Myh7) involved in myoblast differentiation while it decreased the expression of atrophic markers including muscle RING-finger protein-1 (MuRF1), mothers against decapentaplegic homolog (Smad)2, and Smad3. In addition, polygalacin D promoted peroxisome proliferator-activated receptor-gamma coactivator (Pgc1α) expression and reduced the level of mitochondrial fission regulators such as dynamin-1-like protein (Drp1) and mitochondrial fission 1 (Fis1). In a zebrafish model of FOLFIRI-induced muscle atrophy, polygalacin D improved not only mitochondrial dysfunction but also slow and fast muscle fiber atrophy. Conclusion: These results demonstrated that polygalacin D promotes myogenesis and alleviates chemotherapy-induced muscle atrophy by improving mitochondrial function. Thus, polygalacin D could be useful as nutrition support to prevent and ameliorate muscle wasting and weakness.