• Animal Bioscience
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• v.34 no.9
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• pp.1514-1524
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• 2021

Objective: This study investigated the meat quality characteristics, endogenous proteolytic enzymes, collagen content, and myosin heavy chain (MyHC) isoforms of different muscles of Thai native cattle (TNC). Methods: Infraspinatus (IF), Longissimus thoracis (LT), and Supraspinatus (SS) muscles were obtained from two TNC breeds, Kho-Lan (KL, n = 7) and Kho-Isaan (KI, n = 7). The muscle and meat characteristics of TNC breeds and their relationship with MyHC expression were examined. Results: Three MyHC isoforms namely MyHC I, MyHC IIa, and MyHC IIx were detected in the muscles. The KL had higher (p<0.05) MyHC IIx than the KI. The IF muscle had higher (p<0.05) MyHC I compared to other muscles. The LT muscle had the least MyHC I. The LT had higher (p<0.05) MyHC IIx than the IF and SS muscles. The IF presented the least MyHC IIx. The KL had higher (p<0.05) lightness and moisture content and lower crude protein, redness, cooking loss, shear force, and calpastatin than the KI. The glycogen, total collagen, soluble collagen, crude protein, ash contents, and troponin T degradation product of IF and SS were lower (p<0.05) than that of LT. Ether extract in LT was lower (p<0.05) than that of IF and SS. The percentage of MyHC I, MyHC IIa, and MyHC IIx were significantly correlated with muscle and meat characteristics of TNC. Conclusion: These results suggest that the differences in the MyHC isoforms may partly account for the variation in meat quality between breeds and among muscles of TNC.

• BMB Reports
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• v.51 no.7
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• pp.350-355
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• 2018

HnRNPK is a multifunctional protein that participates in chromatin remodeling, transcription, RNA splicing, mRNA stability and translation. Here, we uncovered the function of hnRNPK in regulating the proliferation and differentiation of myoblasts. hnRNPK was mutated in the C2C12 myoblast cell line using the CRISPR/Cas9 system. A decreased proliferation rate was observed in hnRNPK-mutated cells, suggesting an impaired proliferation phenotype. Furthermore, increased G2/M phase, decreased S phase and increased sub-G1 phase cells were detected in the hnRNPK-mutated cell lines. The expression analysis of key cell cycle regulators indicated mRNA of Cyclin A2 was significantly increased in the mutant myoblasts compared to the control cells, while Cyclin B1, Cdc25b and Cdc25c were decreased sharply. In addition to the myoblast proliferation defect, the mutant cells exhibited defect in myotube formation. The myotube formation marker, myosin heavy chain (MHC), was decreased sharply in hnRNPK-mutated cells compared to control myoblasts during differentiation. The deficiency in hnRNPK also resulted in the repression of Myog expression, a key myogenic regulator during differentiation. Together, our data demonstrate that hnRNPK is required for myoblast proliferation and differentiation and may be an essential regulator of myoblast function.

• The Korea Journal of Herbology
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• v.35 no.3
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• pp.9-16
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• 2020

Objectives : Sarcopenia is a disease that leads to a decrease in skeletal muscle, and the importance of prevention and treatment thereof is increasing in an aging society. However, there is a definite limitation of exercise therapy for sarcopenia, and thus, there is an urgent need for a pharmacologic research to the treatment of sarcopenia. Methods : 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) assay was performed to confirm the antioxidant efficacy of water extract of Lacca Sinica Exsiccata (WELSE). To determine the effect of WELSE on myoblast activity, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay was performed. To confirm the effect of WELSE on the differentiation of myoblast into myotubes, protein expression levels of myosin heavy chain 3 (Myh3) and paired box 3/7 (pax3/7) were confirmed by immunoblot analysis. In addition, immunofluorescence microscopy was performed to confirm the effect on myotube formation of WELSE. Results : It was confirmed that WELSE had high antioxidant activity and showed no cytotoxicity to myoblast up to 200 ㎍/㎖ concentration. Myoblast was treated with WELSE at a concentration of 100 ㎍/㎖ and differentiated for 5 days. The expression of Myh3, which forms myotubes, was promoted and the morphology of myotubes was changed and Increasing the thickness. Conclusions : In this paper, we confirmed the excellent antioxidant efficacy of WELSE and positive effects on muscle differentiation and myotube formation. These results suggest valuable as a material for pharmaceutical research on the prevention and treatment of sarcopenia.

• Animal cells and systems
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• v.1 no.2
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• pp.355-361
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• 1997

We have screened available chromosomal deficiencies on the X chromosome for genetic loci whose zygotic expression is required for body-wall muscle development during embryogenesis in Caenorhabditis elegans. Previously, it had been reported that no sign of muscle development was detected in nullo-X embryos arrested at an early stage of embryogenesis. Based on this observation, it has been suggested that genetic loci exist on the X chromosome whose zygotic expression is essential for body-wall muscle formation. In order to identify such myogenic loci, 9 chromosomal deficiencies covering approximately 45% of the X chromosome have been tested. Homozygous embryos from these deficiency strains were collected and terminal phenotypes of arrested embryos were observed by Nomarski microscopy. As a secondary assay, monoclonal antibodies against two myosin heavy chain (MHC) isoforms, the products of the myo-3 and unc-54 genes, were used to detect body-wall muscle differentiation. All the homozygous deficiency embryos were positively stained with both MHC antibodies and muscle twitching movement was observed in most cases. Combined with previously analyzed deficiencies, our deficiency screen has covered approximately 70% of the X chromosome. We conclude that the regions covered by the available deficiencies on the X chromosome do not include any myogenic locus required for body-wall muscle formation. Alternatively, the possibility that nullo-X embryo may not form body-wall muscle due to a general failure to differentiate during embryogenesis remains to be tested.

• Fisheries and Aquatic Sciences
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• v.19 no.3
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• pp.12.1-12.8
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• 2016

Roe is the term used to describe fish eggs (oocytes) gathered in skeins and is one of the most valuable food products from fishery sources. Thus, means of processing are required to convert the underutilized yellowfin tuna roes (YTR) into more marketable and acceptable forms as protein concentrate. Roe protein concentrates (RPCs) were prepared by cooking condition (boil-dried concentrate, BDC and steam-dried concentrate, SDC, respectively) and un-cooking condition (freeze-dried concentrate, FDC) from yellowfin tuna roe. The yield of RPCs was in the range from 22.2 to 25.3 g/100 g of roe. RPCs contained protein (72.3-77.3 %), moisture (4.3-5.6 %), lipid (10.6-11.3 %) and ash (4.3-5.7 %) as the major constituents. The prominent amino acids of RPCs were aspartic acid, 8.7-9.2, glutamic acid, 13.1-13.2, and leucine, 8.5-8.6 g/100 g of protein. Major differences were not observed in each of the amino acid. K, S, Na, and P as minerals were the major elements in RPCs. No difference noted in sodium dodecyl sulfate polyacrylamide gel electrophoresis protein band (15-100 K) possibly representing partial hydrolysis of myosin. Therefore, RPCs from YTR could be use potential protein ingredient for human food and animal feeds.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.9
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• pp.1507-1515
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• 2018

Objective: In the poultry industry, the most important economic traits are meat quality and carcass yield. Thus, many studies were conducted to investigate the regulatory pathways during muscle differentiation. To gain insight of muscle differentiation mechanism during growth period, we identified and validated calcium-related genes which were highly expressed during muscle differentiation through mRNA sequencing analysis. Methods: We conducted next-generation-sequencing (NGS) analysis of mRNA from undifferentiated QM7 cells and differentiated QM7 cells (day 1 to day 3 of differentiation periods). Subsequently, we obtained calcium related genes related to muscle differentiation process and examined the expression patterns by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). Results: Through RNA sequencing analysis, we found that the transcription levels of six genes (troponin C1, slow skeletal and cardiac type [TNNC1], myosin light chain 1 [MYL1], MYL3, phospholamban [PLN], caveolin 3 [CAV3], and calsequestrin 2 [CASQ2]) particularly related to calcium regulation were gradually increased according to days of myotube differentiation. Subsequently, we validated the expression patterns of calcium-related genes in quail myoblasts. These results indicated that TNNC1, MYL1, MYL3, PLN, CAV3, CASQ2 responded to differentiation and growth performance in quail muscle. Conclusion: These results indicated that calcium regulation might play a critical role in muscle differentiation. Thus, these findings suggest that further studies would be warranted to investigate the role of calcium ion in muscle differentiation and could provide a useful biomarker for muscle differentiation and growth.

• BMB Reports
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• v.34 no.6
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• pp.509-516
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• 2001

A genomic DNA fragment that contains the gene, which codes for a novel extracellular serine protease in Burkholderia pseudomallei, was cloned by using pQE40 as a vector. It was maintained in Escherichia coli JM109. The expression of the gene(s) resulted in the production of a 52 kDa protease. The recombinant protease was purified from the culture filtrate via ammonium sulfate fractionation, gel filtration, and anion-exchange chromatography. The purified protease had an optimum pH and temperature of pH 8.9 and $38^{\circ}C$, respectively. The protease activity was inhibited by EGTA, EDTA, and PMSF, but not 1,10-phenanthroline. The first 11 amino acid residues from the N-terminus of the purified protease were identified as LAPNDPYYYGY. PNDPYY was found to show homology to the Bacillus cereus microbial serine protease and B. subtilis PD498 serine protease. These results indicate that the protease that was purified in this study is an extracellular calcium-dependent serine protease. The purified protease was able to digest the human serum 19A, IgG, albumin, and transferrin, as well as bovine muscle actin and myosin. Furthermore, it was able to promote or cause dermonecrosis in experimental rabbits. These results propose the possible role of a novel B. pseudomallei extracellular calcium-dependent serine protease in the virulence of the pathogen.

• Natural Product Sciences
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• v.26 no.1
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• pp.71-78
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• 2020

The plant Dendropanax morbifera Léveille is effective folk medicines for the treatment of several conditions, such as infectious diseases, skin diseases, and other illnesses. Although the inhibitory effects of D. morbifera on the proliferation and migration of vascular smooth muscle cells (VSMCs) have been shown in our previous study, its effects in vivo remain to be elucidated. In this study, we aimed to investigate the protective effects of the extracts from D. morbifera (EDM) on neointimal hyperplasia of rat carotid artery and explore the underlying mechanisms. We observed that the ratio of intima to media thickness (I/M) was significantly decreased in the EDM-treated groups by ~80% compared to that of the control. The expression of Ki-67 and proliferating cell nuclear antigen was decreased by ~70% in the EDM-treated groups compared to that of the control. In addition, matrix metalloproteinase (MMP)2 and MMP9 significantly reduced in the neointimal layer of the EDM-treated groups. Moreover, the decreased levels of contractile phenotypic markers of VSMCs, such as α-smooth muscle actin, myocardin, and smooth muscle-myosin heavy chain, were successfully restored by EDM treatment. Furthermore, the levels of synthetic phenotypic markers, cellular retinal binding protein 1 and connexin 43 were also restored to normal levels. These results suggest that EDM inhibits vascular neointimal hyperplasia induced by balloon injury in rats via phenotypic modulation of VSMCs. Therefore, EDM may be a potential drug candidate for the prevention of restenosis.

• Archives of Pharmacal Research
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• v.29 no.8
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• pp.657-665
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• 2006

We recently reported that dimethylsphingosine (DMS), a metabolite of sphingolipids, increased intracellular pH and $Ca^{2+}$ concentration in U937 human monocytes. In the present study, we found that dimethylphytosphingosine (DMPH) induced the above responses more robustly than DMS. However, phytosphingosine, monomethylphytosphingosine or trimethylsphingosine showed little or no activity. Synthetic C3 deoxy analogues of sphingosine did show similar activities, with the C16 analogue more so than C18. The following structure-activity relationships were observed between DMS derivatives and the intracellular pH and $Ca^{2+}$ concentrations in U937 monocytes; 1) dimethyl modification is important for the DMS-induced increase of intracellular pH and $Ca^{2+}$, 2) the addition of an OH group on C4 enhances both activities, 3) the deletion of the OH group on C3 has a negligible effect on the activities, and 4) C16 appears to be more effective than C18. We also found that W-7, a calmodulin inhibitor, blocked the DMS-induced pH increase, whereas, KN-62, ML9, and MMPX, specific inhibitors for calmodulin-dependent kinase II, myosin light chain kinase, and $Ca^{2+}$-calmodulin-dependent phosphodiesterase, respectively, did not affect DMS-induced increases of pH in the U937 monocytes.

• Food Science of Animal Resources
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• v.39 no.2
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• pp.229-239
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• 2019

The objectives of this study were to determine the interaction between porcine myofibrillar proteins and various gelatins (bovine hide, porcine skin, fish skin, and duck skin gelatins) and their impacts on gel properties of porcine myofibrillar proteins. Porcine myofibrillar protein was isolated from pork loin muscle (M. longissimus dorsi thoracis et lumborum). Control was prepared with only myofibrillar protein (60 mg/mL), and gelatin treatments were formulated with myofibrillar protein and each gelatin (9:1) at the same protein concentration. The myofibrillar protein-gelatin mixtures were heated from $10^{\circ}C$ to $75^{\circ}C$ ($2^{\circ}C/min$). Little to no impacts of gelatin addition on pH value and color characteristics of heat-induced myofibrillar protein gels were observed (p>0.05). The addition of gelatin slightly decreased cooking yield of heat-induced myofibrillar protein gels, but the gels showed lower centrifugal weight loss compared to control (p<0.05). The addition of gelatin significantly decreased hardness, cohesiveness, gumminess, and chewiness of heat-induced myofibrillar gels. Further, sodium dodecyl poly-acrylamide gel electrophoresis (SDS-PAGE) showed no interaction between myofibrillar proteins and gelatin under non-thermal conditions. Only a slight change in the endothermic peak (probably myosin) of myofibrillar protein-gelatin mixtures was found. The results of this study show that the addition of gelatin attenuated the water-holding capacity and textural properties of heat-induced myofibrillar protein gel. Thus, it could be suggested that well-known positive impacts of gelatin on quality characteristics of processed meat products may be largely affected by the functional properties of gelatin per se, rather than its interaction with myofibrillar proteins.