• BMB Reports
• /
• 제49권6호
• /
• pp.303-304
• /
• 2016

Myoblast fusion is important for skeletal muscle formation. Even though the knowledge of myoblast fusion mechanism has accumulated over the years, the initial signal of fusion is yet to be elucidated. Our study reveals the novel function of a phosphatidylserine (PS) receptor, stabilin-2 (Stab2), in the modulation of myoblast fusion, through the recognition of PS exposed on myoblasts. During differentiation of myoblasts, Stab2 expression is higher than other PS receptors and is controlled by calcineurin/NFAT signaling on myoblasts. The forced expression of Stab2 results in an increase in myoblast fusion; genetic ablation of Stab2 in mice causes a reduction in muscle size, as a result of impaired myoblast fusion. After muscle injury, muscle regeneration is impaired in Stab2-deficient mice, resulting in small myofibers with fewer nuclei, which is due to reduction of fusion rather than defection of myoblast differentiation. The fusion-promoting role of Stab2 is dependent on its PS-binding motif, and the blocking of PS-Stab2 binding impairs cell-cell fusion on myoblasts. Given our previous finding that Stab2 recognizes PS exposed on apoptotic cells for sensing as an "eat-me" signal, we propose that PS-Stab2 binding is required for sensing of a "fuse-me" signal as the initial signal of myoblast fusion.

• Molecules and Cells
• /
• 제25권1호
• /
• pp.1-6
• /
• 2008

Osteoarthritis (OA), one of the most common skeletal disorders characterized by cartilage degradation and osteophyte formation in joints, is induced by accumulated mechanical stress; however, little is known about the underlying molecular mechanism. Several experimental OA models in mice by producing instability in the knee joints have been developed to apply approaches from mouse genetics. Although proteinases like matrix metalloproteinases and aggrecanases have now been proven to be the principal initiators of OA progression, clinical trials of proteinase inhibitors have not been successful for the treatment, turning the interest of researchers to the upstream signals of proteinase induction. These signals include undegraded and fragmented matrix proteins like type II collagen or fibronection that affects chondrocytes through distinct receptors. Another signal is proinflammatory factors that are produced by chondrocytes and synovial cells; however, recent studies that used mouse OA models in knockout mice did not support that these factors have a role in the central contribution to OA development. Our mouse genetic approaches found that the induction of a transcriptional activator Runx2 in chondrocytes under mechanical stress contributes to the pathogenesis of OA through chondrocyte hypertrophy. In addition, chondrocyte apoptosis has recently been identified as being involved in OA progression. We hereby propose that these endochondral ossification signals may be important for the OA progression, suggesting that the related molecules can clinically be therapeutic targets of this disease.

• Nutrition Research and Practice
• /
• 제7권1호
• /
• pp.15-21
• /
• 2013

Leaf of Sasa borealis, a species of bamboo, has been reported to exhibit anti-hyperglycemic effect. However, its antidiabetic mechanism is not fully understood. In this study, we examined whether an extract of S. borealis activates AMP-activated protein kinase (AMPK) and exerts anti-hyperglycemic effects. Treatment with the S. borealis extract increased insulin signaling and phosphorylation of AMPK and stimulated the expression of its downstream targets, including $PPAR{\alpha}$, ACO, and CPT-1 in C2C12 cells and $PPAR{\alpha}$ in HepG2 cells. However, inhibition of AMPK activation attenuated insulin signaling and prevented the stimulation of AMPK target genes. The S. borealis extract increased glucose uptake in C2C12 cells and suppressed expression of the gluconeogenic gene, PEPCK in HepG2 cells. The extract significantly reduced blood glucose and triglyceride levels in STZ-induced diabetic mice. The extract enhanced AMPK phosphorylation and increased Glut-4 expression in the skeletal muscle of the mice. These findings demonstrated that the S. borealis extract exerts its anti-hyperglycemic effect through activation of AMPK and enhancement of insulin signaling.

• Journal of mucopolysaccharidosis and rare diseases
• /
• 제1권2호
• /
• pp.44-48
• /
• 2015

Body fat distribution in patients with Prader-Willi syndrome (PWS) is characterized by reduce lean body mass (LBM), increased total body fat mass (FM), and lower percentage of visceral adipose tissue (VAT). Individuals with PWS seem to have a lower risk for insulin resistance with high levels of adiponectin, an anti-atherogenic adipocytokine that is decreased in visceral fat hypertrophy subjects compared to simple obese subjects, both in children and in adults. The mechanism of the reduction in visceral adiposity in PWS is still unclear. It might be related to qualitative intrinsic characteristics of adipocyte or novel genetic influences on the control of fat distribution. However, obesity remains a critical problem, and obesity status plays a crucial role in individual metabolic risk clustering and development of metabolic syndrome (Mets) in PWS children and adults. Long-term growth hormone (GH) treatment after cessation of skeletal growth improved body composition, with an increase in lean body mass and a reduction in total body fat and subcutaneous and visceral fat in PWS adults. Thus, the role of GH is important after childhood because it might attenuate obesity and Mets in PWS adult by adipocyte modification.

• 생약학회지
• /
• 제47권2호
• /
• pp.172-178
• /
• 2016

Using high-fat diet-induced obese (DIO) mice, the mechanism of anti-adiposity and anti-obesity actions produced by Inonotus obliquus water extract (IOE) was investigated. Significant reduction in body weight in DIO mice orally administrated with IOE for 8 weeks compared to IOE-non-treated control mice was observed, which was attributed to the reduction of epididymal and mesenteric adipose tissue, but not the liver and skeletal muscle. Adiponectin synthesis in epididymal adipose tissue (EAT) and AMPK phosphorylation in the liver were significantly increased in IOE-treated DIO mice. Gene expression analysis showed that IOE-treated DIO mice had higher expression levels of lipogenic genes in EAT and fatty-acid oxidative genes in the liver, but lower expression levels of hepatic pro-inflammatory cytokines compared to IOE-non-treated controls. Our findings confirm a therapeutic potential of Inonotus obliquus for reducing adiposity and ameliorating hyperlipidemia to treat metabolic disorders.

• 대한기계학회논문집A
• /
• 제28권8호
• /
• pp.1237-1244
• /
• 2004

The orthodontic surgery including lingual orthodontics has recently attracted a person's attention due to its functional and esthetic appreciation. The skeletal anchorage with the miniscrew is newly adopted in the lingual orthodontics to assist the upholding ability. The appliciation needs to understand the mechanism of the orthodontic appliance and its related orthodontic correction for optimal orthodontic treatment. There is, however, few information about the qualitative and quantitative effect of the orthodontic appliance with the miniscrew has not been well identified. In this paper, three dimensional finite element analysis is introduced to the lingual orthodontics in order to investigate the effect of the anterior retraction force on the miniscrew and transpalatal arch wire. The analysis determines the adequate location of the miniscrew and the point of force application of the anchorage system in the lingual orthodontics. The analysis results demonstrate the effect of the position of the miniscrew and the transpalatal arch wire on the lingual orthodontics.

• 한국한의학연구원논문집
• /
• 제14권2호
• /
• pp.75-80
• /
• 2008

Background: Qigong is one energy-healing intervention used to prevent and cure ailments and to improve health through regular practice. Although Qigong-neither itself nor its postulated mechanism of action-are within the paradigm of modern Western medical science. effects on the human body could be possible. Objectives: This study aims to review the bibliography, biological responses and therapeutic effects of Qigong. In the process, this review grasp trends in this field of studies and direct further researches into the right direction. Method: The computerized Korean databases were searched from their respective inception up to January 2008. The search terms used were 'Qi', 'Qigong', 'Doin', 'training', 'bioenergy', 'life nurturing' and random or Korean language terms related to qigong. Several specialized journals were also manually searched for relevant articles. Result: Since the 1990s, Qigong papers in the Korean Literature have been increased. Clinical research studies are among the most control design study. Research subjects are less patient than the general public. The most common treatment disease was Musculo-skeletal disorder. Conclusions: The depth study for the each Qigong is needed. Specifically, I think it should be a clinical studies and qualified research methods for evaluation are needed.

• Journal of Animal Science and Technology
• /
• 제54권3호
• /
• pp.219-226
• /
• 2012

Gender specificity in muscle growth and development is well known. Genesis of muscle is dependent on proliferation and differentiation potential of resident myogenic satellite cells (MSCs) present in muscle fibers. Multipotential capacity of forming myocyte, osteocyte, and adipocyte like cell makes MSCs a unique stem cell. To understand the molecular mechanism involved in determination of muscle quality due to difference in hormone concentration of different gender of animals, MSCs were isolated from bovine skeletal muscle and cultured in male, female, and castrated serum supplemented media. DNA microarray used consisted of 24,000 spots with 70 mer oligo in each spot. A total of 88 genes were up-regulated and 551 genes were down-regulated by more than two fold. Among up-regulated gene, 33, 34, and 21 genes were found up-regulated in cells grown in male, female, and castrated serum, respectively. Interestingly, male serum showed 4, female 11 and castrated male showed 4 genes expressed highly in each gender. Further study on the highly up-regulated gene may unfold the mystery of gender specificity found in muscle development. Also, the identification of differentially expressed genes in gender-specific serum will add information on infrastructure of bovine genome research.

• 한국산학기술학회논문지
• /
• 제5권1호
• /
• pp.34-37
• /
• 2004

소성 온도에 따른 수소 이동 속도가 반응 속도에 미치는 영향을 조사하였다. 반응 온도 증가에 따른 Pt/HxMoO₃/SiO₂시료의 1-butene의 이성질화 반응의 수율, 전화율 및 선택도를 측정하였다. 소성 조건 변화에 따른 수소 이동 현상이 반응에 참여하는 반응 기구를 조사하였다. 반응 온도 증가에 따라 전화율은 감소하지만, i-butene의 수율은 증가하는 것으로 나타났다. 반응 온도 증가에 따른 선택도의 변화로부터 2가지 반응 기구가 존재하는 것으로 추정되었다.

• 대한의생명과학회지
• /
• 제18권1호
• /
• pp.49-55
• /
• 2012

Numerous biochemical molecules have been implicated in the development of muscular atrophy. However, control mechanisms associated with muscular disease are not clear. The present study was conducted to investigate gene expression profiles of rat muscle during the denervation to atrophy transition processes. We isolated total RNA from rats suffering from partial muscle atrophy (P) and electromyostimulated atrophy (PE) and synthesized cDNA using annealing control primers. Using 20 ACPs for PCR, we cloned 18 DEGs using TOPO TA cloning vector, sequenced, and analyzed their identities using BLAST search. Sequences of 14 clones significantly matched database entries, while one clone was ESTs, and 3 clones were unidentified. Different expression profiles of selected DEGs between P and PE were confirmed. The troponin T, Fkbp1a, RGD1307554, Phtf1, Atp1a1 and Commd3 were highly expressed genes in the P and PE groups, while Krox-25 and TCOX2 were only expressed genes in the P group, the Sv2b and Marcks were only expressed genes in PE group. also, Cox8h was highly expressed genes in PE groups. The ASPH, ND1, and ARPL1 were highly expressed genes in the P and PE groups. List of genes obtained from the present study might provide an insight for the study of mechanism regulating muscle atrophy and electrostimulated muscle atrophy transitions. These data suggest that troponin T, Fkbp1a, RGD1307554, Phtf1, Atp1a1, and Commd3 are potentially useful as clinical biomarkers of age-related muscle atrophy and dysfunction.