• Biomedical Science Letters
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• v.13 no.4
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• pp.251-261
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• 2007

A myofiber of skeletal muscle is composed of myofibrils, sarcolemma (plasma membrane), and constameres, which anchor the myofibrils to the sarcolemma. Achvillin is a recently identified F-actin binding muscle protein, co-isolates with dystrophin and caveolin-3 in low-density sarcolemma of striated muscle, and colocalizes with dystrophin at costameres, the specialized adhesion sites in muscle. Archvillin also binds to nebulin and localizes at myofibrillar Z-discs, the lateral boundaries of the sarcomere in muscle. However other roles of archvillin on the dynamics of myofibrillogenesis remain to be defined. The goal of this study is, by using siRNA-mediated gene silencing technique, to investigate the effect of archvillin on the dynamics of myofibrillogenesis in cell culture of a mouse skeletal myogenic cell line (C2C12), where presumptive myoblasts withdraw from the cell cycle, fuse, undergo de novo myofibrillogenesis, and differentiate into mature myotubes. The roles of archvillin in the assembly and maintenance of myofibril and during the progression of myofibrillogenesis induced in skeletal myoblast following gene silencing in the cell culture were investigated. Fluorescence microscopy demonstrated that the distribution of archvillin was changed along the course of myofibril assembly with nebulin, vinculin and F-actin and then located at Z-lines with nebulin. Fluorescence microscopy demonstrated that knockdown of mouse archvillin expression led to an impaired assembly of new myofibrillar clusters and delayed fusion and myofibrillogenesis although the mouse archvillin siRNA did not affect those expressions of archvillin binding proteins, such as nebulin and F-actin. This result is corresponded with that of RT-PCR and western blots. When the perturbed archvillin was rescued by co-transfection with GFP or Red tagged human archvillin construct, the inhibited cell fusion and myotube formation was recovered. By using siRNA technique, archvillin was found to be involved in early stage of myofibrillogenesis. Therefore, the current data suggest the idea that archvillin plays critical roles on cell fusion and dynamic myofibril assembly.

• Biomedical Science Letters
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• v.10 no.3
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• pp.259-262
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• 2004

The aim of present study was to examine the effect of carrageenan on the tendon of skeletal muscle of rat. The tendon damage was induced by injection of carrageenan into skeletal hind muscle of rats. Rats were killed on 48 hours after carrageenan injection. The resulting tendons were fixed with 10％ neutral buffered formalin (NBF), dehydrated, embedded, sectioned by 4 μm, and stained by phosphotungstic acid hematoxylin (PTAH) or hematoxylin-eosin (H-E). Carrageenan induced the segregation of tendon fibers, intratendinous cleft, segregation of muscle cell group, wave arrangement of tendon fiber. The results suggest that carrageenan induced tendon damage of rat's skeletal muscle by morphological changes.

• Anatomy and Cell Biology
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• v.56 no.3
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• pp.401-403
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• 2023

This case report describes a variation of the flexor digitorum brevis (FDB) with a separated muscle belly and tendon at the fifth toe. The narrow tendon and muscle belly for the fifth toe arose from the intermuscular septum between the FDB and abductor digiti minimi adjacent to the arising fibers of the FDB, separating from its other fibers. The tendon and muscle belly for the fifth toe became wider at the base of the metatarsal bones and narrower as it coursed toward the toes in a fusiform shape. The tendon and muscle belly for the fifth toe became thin at the midfoot and coursed just beneath the flexor digitorum longus tendon and entered the digital tendinous sheath. FDB variations including that described herein should be considered when performing various surgical procedures and evaluating the biomechanics of the foot.

• Anatomy and Cell Biology
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• v.57 no.3
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• pp.459-462
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• 2024

The current cadaveric report aims to present a coexistence of two uncommon variants of the posterior leg compartment. The variations were detected, during classical dissection in an 84-year-old donated male cadaver. On the left lower limb, the gastrocnemius muscle was identified as having a third head that was attached to the lateral head. This variant is known as gastrocnemius tertius muscle and was bilaterally identified. The left-sided plantaris muscle had two distinct heads that fused into a common tendon that was inserted into the calcaneal tuberosity. Knowledge of these variants is important, due to their close relationship with the popliteal neurovascular bundle. Clinicians should be aware, to avoid pitfalls and take them into account in their differential diagnosis.

• The Journal of Korean Physical Therapy
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• v.14 no.4
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• pp.87-94
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• 2002

Low intensity laser irradiation is potential physical agent that triggers the muscle regeneration by previous study. In muscle regeneration, a number of growth factors also promotes that is triggered in response to muscle damage. The transforming growth factor(TGF)-$\beta$ is involved in the activation of cell proliferation and the inhibition of cell differentiation in muscle regeneration. This is secreted not only autocrine system but also paracrine and endocrine. Therefore, We investigated that effects of Gallium aluminum arsenide(GaAlAs) diode laser for the expression of TGF-$\beta$ on lumbar spinal cord after extensor digitorum muscle crush injury. After laser irradiation, the immunoreactivity of TGF-$\beta$ was increased bilaterally in gray mater of spinal cord. Especially, in 1 day, experimental group was highed than control, and in 3 day, lateral motor nucleus were storong immunoreactivy of TGF-$\beta$. Also, in 1 and 2 day, TGF-$\beta$ was showed in white mater as well as gray mater, but in 3 day, only showed in gray mater. These data may suggests to the establishment of laser irradiation on spinal cord for skeletal muscle injury.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.1
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• pp.3-12
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• 2018

Objective: DNA methylation plays a major role in regulating the expression of genes related to traits of economic interest (e.g., weight gain) in livestock animals. This study characterized and investigated the functional inferences of genome-wide DNA methylome in the loin (longissimus dorsi) muscle (LDM) of swine. Methods: A total of 8.99 Gb methylated DNA immunoprecipitation sequence data were obtained from LDM samples of eight Duroc pigs (four pairs of littermates). The reference pig genome was annotated with 78.5% of the raw reads. A total of 33,506 putative methylated regions (PMR) were identified from methylated regions that overlapped at least two samples. Results: Of these, only 3.1% were commonly observed in all eight samples. DNA methylation patterns between two littermates were as diverse as between unrelated individuals (p = 0.47), indicating that maternal genetic effects have little influence on the variation in DNA methylation of porcine LDM. The highest density of PMR was observed on chromosome 10. A major proportion (47.7%) of PMR was present in the repeat regions, followed by introns (21.5%). The highest conservation of PMR was found in CpG islands (12.1%). These results show an important role for DNA methylation in species- and tissue-specific regulation of gene expression. PMR were also significantly related to muscular cell development, cell-cell communication, cellular integrity and transport, and nutrient metabolism. Conclusion: This study indicated the biased distribution and functional role of DNA methylation in gene expression of porcine LDM. DNA methylation was related to cell development, cell-cell communication, cellular integrity and transport, and nutrient metabolism (e.g., insulin signaling pathways). Nutritional and environmental management may have a significant impact on the variation in DNA methylation of porcine LDM.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.2
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• pp.141-150
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• 2019

Despite increased evidence of bio-activity following far-infrared (FIR) radiation, susceptibility of cell signaling to FIR radiation-induced homeostasis is poorly understood. To observe the effects of FIR radiation, FIR-radiated materials-coated fabric was put on experimental rats or applied to L6 cells, and microarray analysis, quantitative real-time polymerase chain reaction, and wound healing assays were performed. Microarray analysis revealed that messenger RNA expressions of rat muscle were stimulated by FIR radiation in a dose-dependent manner in amount of 10% and 30% materials-coated. In 30% group, 1,473 differentially expressed genes were identified (fold change [FC] > 1.5), and 218 genes were significantly regulated (FC > 1.5 and p < 0.05). Microarray analysis showed that extracellular matrix (ECM)-receptor interaction, focal adhesion, and cell migration-related pathways were significantly stimulated in rat muscle. ECM and platelet-derived growth factor (PDGF)-mediated cell migration-related genes were increased. And, results showed that the relative gene expression of actin beta was increased. FIR radiation also stimulated actin subunit and actin-related genes. We observed that wound healing was certainly promoted by FIR radiation over 48 h in L6 cells. Therefore, we suggest that FIR radiation can penetrate the body and stimulate PDGF-mediated cell migration through ECM-integrin signaling in rats.

• Anatomy and Cell Biology
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• v.57 no.2
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• pp.278-287
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• 2024

Striated muscle insertions into the skin and mucosa are present in the head, neck, and pelvic floor. We reexamined the histology of these tissues to elucidate their role in transmission of the force. We examined histological sections of 25 human fetuses (gestational ages of ~11-19 weeks and ~26-40 weeks) and 6 cadavers of elderly individuals. Facial muscle insertion or terminal almost always formed as an interdigitation with another muscle or as a circular arrangement in which muscle fiber insertions were sandwiched and mechanically supported by other muscle fibers (like an in-series muscle). Our examination of the face revealed some limited exceptions in which muscle fibers that approached the dermis were always in the nasalis and mentalis muscles, and often in the levator labii superioris alaeque nasi muscle. The buccinator muscle was consistently inserted into the basement membrane of the oral mucosa. Parts of the uvulae muscle in the soft palate and of the intrinsic vertical muscle of the tongue were likely to direct toward the mucosa. In contrast, the pelvic floor did not contain striated muscle fibers that were directed toward the skin or mucosa. Although 'cutaneous muscle' is a common term, the actual insertion of a muscle into the skin or mucosa seemed to be very rare. Instead, superficial muscle insertion often consisted of interdigitated muscle bundles that had different functional vectors. In this case, the terminal of one muscle bundle was sandwiched and fixed mechanically by other bundles.

• Biomolecules & Therapeutics
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• v.19 no.2
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• pp.187-194
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• 2011

Atherosclerosis and post-angiography restenosis are associated with intimal thickening and concomitant vascular smooth muscle cell (VSMC) proliferation. Obovatol, a major biphenolic component isolated from the Magnolia obovata leaf, is known to have anti-inflammatory and anti-tumor activities. The goal of the present study was to enhance the inhibitory effects of obovatol to improve its potential as a preventive or therapeutic agent in atherosclerosis and restenosis. Platelet-derived growth factor (PDGF)-BB-induced proliferation of rat aortic smooth muscle cells (RASMCs) was examined in the presence or absence of a newly synthesized obovatol derivative, OD78. The observed anti-proliferative effect of OD78 was further investigated by cell counting and [$^3H$]-thymidine incorporation assays. Treatment with 1-4 ${\mu}M$ OD78 dose-dependently inhibited the proliferation and DNA synthesis of 25 ng/ml PDGF-BB-stimulated RASMCs. Accordingly, OD78 blocked PDGF-BB-induced progression from the $G_0/G_1$ to S phase of the cell cycle in synchronized cells. OD78 decreased the expression levels of CDK4, cyclin E, and cyclin D1 proteins, as well as the phosphorylation of retinoblastoma protein and proliferating cell nuclear antigen; however, it did not change the CDK2 expression level. In addition, OD78 inhibited downregulation of the cyclin-dependent kinase inhibitor (CKI) $p27^{kip1}$. However, OD78 did not affect the CKI $p21^{cip1}$ or phosphorylation of early PDGF signaling pathway. These results suggest that OD78 may inhibit PDGF-BB-induced RASMC proliferation by perturbing cell cycle progression, potentially through $p27^{kip1}$ pathway activation. Consequently, OD78 may be developed as a potential anti-proliferative agent for the treatment of atherosclerosis and angioplasty restenosis.

• The Journal of the Korean bone and joint tumor society
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• v.19 no.2
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• pp.87-91
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• 2013

Diffuse-type giant cell tumor is relatively rare than localized giant cell tumor. Moreover, diffuse type giant cell tumor is common in intraarticular area, rarely occurs at intramuscular or subcutaneous layer. We experienced 1 case of giant cell tumor within the deltoid muscle. So we report this case with review of the literatures.