• 운동과학
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• 제26권3호
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• pp.229-237
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• 2017

PURPOSE: This study was to investigate the Glycolysis mediated sarcoplasmic reticulum (SR) $Ca^{2+}$ signal regulates mitochondria $Ca^{2+}$ during skeletal muscle contraction by using glycolysis inhibitor. METHODS: To examine the effect of Glycolysis inhibitor on SR and mitochondria $Ca^{2+}$ content, we used skeletal muscle fiber from gastrocnemius muscle. 2-deoxy glucose and 3-bromo pyruvate used as glycolysis inhibitor, it applied to electrically stimulated muscle contraction experiment. Intracellular $Ca^{2+}$ content, SR, mitochondria $Ca^{2+}$ level and mitochondria membrane potential (MMP) was detected by confocal microscope. Mitochondrial energy metabolism related enzyme, citric acid synthase activity also examined for mitochondrial function during the muscle contraction. RESULTS: Treatment of 2-DG and 3BP decreased the muscle contraction induced SR $Ca^{2+}$ increase however the mitochondria $Ca^{2+}$ level was increased by treatment of inhibitors and showed and overloading as compared with the control group. Glycolysis inhibitor and thapsigargin treatment showed a significant decrease in MPP of skeletal muscle cells compared to the control group. CS activity significantly decreased after pretreatment of glycolysis inhibitor during skeletal muscle contraction. These results suggest that regulation of mitochondrial $Ca^{2+}$ levels by glycolysis is an important factor in mitochondrial energy production during skeletal muscle contraction CONCLUSIONS: These results suggest that mitochondria $Ca^{2+}$ level can be regulated by SR $Ca^{2+}$ level and glycolytic regulation of intraocular $Ca^{2+}$ signal play pivotal role in regulation of mitochondria energy metabolism during the muscle contraction.

• 동의신경정신과학회지
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• 제20권1호
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• pp.147-164
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• 2009

Objectives : We investigated the effects of Sopungsungi-won(Shu!engshunqiyuan) (SSEx1, SSEx2) to treat the metabolic syndrome by the molecular mechanism of regulation of PPAR and modulation of mitochondrial MCAD, VLCAD mRNA expression. Methods : Mouse NMu2Li liver cells and C2C12 skeletal muscle myogenic progenital cells were transiently transfected with expression plasmids for PPAR(PPAR${\alpha}$, PPAR${\delta}$), a luciferase reporter gene construct containing 3 copies of the PPRE from the rat acyl-CoA oxidase gene and ${\beta}$-galactosidase gene. Cells were treated with several concentrated kinds of SSEx1, SSEx2 at the initial time of culture and analyzed PPAR${\alpha}$, PPAR${\delta}$ reporter gene activity using spectrophotometer (405 nm). Total RNA was extracted from SSEx1, SSEx2 and measured mRNA levels of mitochondrial MCAD, VLCAD. Representative RT-PCR bands are shown. Results : 1. SSEx1 increased the expression of PPAR${\alpha}$ reporter gene activities at 0.1 ${\mu}$g/ml (p${\mu}$g/ml (p<0.05), SSEx2 at 0.1 ${\mu}$g/ml (p${\mu}$g/ml (p<0.05) significantly in NMu2Li liver cell lines. 2. SSEx1 increased the expression of PPAR${\alpha}$ reporter gene activities at 1 ${\mu}$g/ml (p${\mu}$g/ml (p${\alpha}$ reporter gene activities in C2C12 skeletal muscle cells. 4. SSEx1 increased the modulation of mitochondrial MCAD mRNA expression (p<0.05) significantly in NMu2Li liver cell lines. 5. SSEx1, SSEx2 both increased the modulation of mitochondrial MCAD mRNA expression (p<0.05) significantly in C2C12 skeletal muscle cells. Conclusions : These results show the SSEx1, SSEx2 can be used as therapeutic agent for metabolic syndrome and it's molecular mechanisms of PPAR more contribute to the activation of PPAR${\alpha}$ then PPAR${\delta}$ reporter gene activities and it's total RNA more contribute to the modulation of mitochondrial MCAD then VLCAD mRNA expression.

• Journal of Korean Neurosurgical Society
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• 제43권2호
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• pp.97-104
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• 2008

Objective: Transient receptor potential vanilloid subfamily type 1 (TRPV1), a most specific marker of the nociceptive primary afferent, is expressed in peptidergic and non-peptidergic primary afferents innervating skin and viscera. However, its expression in sensory fibers to skeletal muscle is not well known. In this study, we studied the neurochemical characteristics of TRPV1-positive primary afferents to skeletal muscles. Methods: Sprague-Dawley rats were injected with total $20{\mu}l$ of 1% fast blue (FB) into the gastrocnemius and erector spinae muscle and animals were perfused 4 days after injection. FB-positive cells were traced in the L4-L5 (for gastrocnemius muscle) and L2-L4 (for erector spinae muscle) dorsal root ganglia. The neurochemical characteristics of the muscle afferents were studied with multiple immunofluorescence with TRPV1, calcitonin gene-related peptide (CGRP) and $P2X_3$. To identify spinal neurons responding to noxious stimulus to the skeletal muscle, 10% acetic acids were injected into the gastrocnemius and erector spinae muscles and expression of phospho extracellular signal-regulated kinase (pERK) in spinal cords were identified with immunohistochemical method. Results: TRPVl was expressed in about 49% of muscle afferents traced from gastrocnemius and 40% of erector spinae. Sixty-five to 60% of TRPV1-positive muscles afferents also expressed CGRP. In contrast, expression of $P2X_3$ immnoreaction in TRPV1-positive muscle afferents were about 20%. TRPV1-positive primary afferents were contacted with spinal neurons expressing pERK after injection of acetic acid into the muscles. Conclusion: It is consequently suggested that nociception from skeletal muscles are mediated by TRPV1-positive primary afferents and majority of them are also peptidergic.

• 현장농수산연구지
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• 제23권1호
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• pp.117-128
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• 2021

한우의 성장단계별 부위 근육발달을 이해하는 것은 도체율 개선에 따른 소득증대와 증체율 증가에 따른 생산효율 향상에 긍정적인 영향을 미친다. 본 연구에서는 한우의 등심과 사태 유래 근육위성세포를 분리 후 세포단위의 발달 및 분화를 비교하여 transcriptome 단위의 작용기전을 제시하였다. 한우의 부위별 근육 유래 근육위성세포의 근섬유의 양은 4일에 가장 높게 나타났고 이후 감소하였다. 한우의 근육위성세포의 발달 단계에 따라 발현되는 총 전사체 유전자의 종류는 사태근육 위성세포에서 높게 나타났다. 등심과 사태 근육 유래 위성세포의 발달단계에 따라 유의적인 차등 유전자 453개를 찾아냈고 이를 이용한 기능유 전체 분석이 필요하다. 등심과 사태유래 근육위성세포를 이용한 동일조건 분화 비교에서 사태유래 근육 위성세포의 분화 시 myosin complex, skeletal muscle contraction, troponin complex, skeletal muscle tissue development 와 같은 근섬유 형성관련 유전자의 발현이 높게 나타나는 것으로 보아 같은 개체의 근육조직에서도 부위별로 차등 발달이 되고 있다는 것을 알 수 있다. 기존 연구에서는 근육의 성장에 대한 이해를 위해 사양과 영양관련 시험이 많이 이루어졌다. 향후 세포단위의 연구들이 많이 이루어져 작용기작에 대한 생물정보 자료를 추가로 적용한다면 한우의 정밀사양을 적용할수 있는 바탕이 마련될 것이다. 또한 근육위성세포의 연구는 추후 동물실험 윤리제도 강화에 따른 비동물 전임상 screening 시험 활용과 대체단백질 산업의 주요 이슈인 배양육 소재 개발 연구와 같이 축산시험연구의 지속적인 확장성에 많은 영향을 미칠 것으로 생각된다.

• 대한본초학회지
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• 제22권2호
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• pp.155-161
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• 2007

Objectives: Evidences suggests that Ginkgo biloba, a widely used traditional medicine, shows a hypoglycemic effect. Thus, we investigatd the effect of G. biloba extract (GB) on glucose uptake in L6 rat skeletal muscle cells. Method : Effect of GB on glucose uptake and phosphatidylinositol (PI) 3-kinase activity were assessed using Glucose uptake assay and PI 3-kinase assay, respectively. Also, AMP-activated protein kinase (AMPK), p38 mitogen activated protein kinase (p38 MAPK) expression were identified by Western blot. Results : Glucose uptake assay revealed that GB increased glucose uptake about 2.5-fold compared to thecontrol. GB stimulated the activity of PI 3-kinase which is a major switch element on the glucose uptake pathway. About a 6.5-fold increase in activity of PI 3-kinase was observed with GB. We then assessed the activity of AMPK, another regulatory molecule on the glucose uptake pathway. The result was that GB increased the phosphorylation level of both AMPK ${\alpha}$l and ${\alpha}$2. The activity of p38 MAPK, a downstream mediator of AMPK, was also increased by CB. Conclusion : These results suggest that GB may stimulate glucose uptake through both PI 3-kinase and AMPK mediated pathways in L6 skeletal muscle cells thereby contributing to glucose homeostasis.

• 생명과학회지
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• 제21권10호
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• pp.1385-1392
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• 2011

SOCS-3와 IGF-I은 근육의 분화 과정 및 근비대 기전에 있어 매우 중요한 조절자 역할을 하는 유전자 및 성장인 자이며, 최근 골격근에서 IGF-I과 SOCS-3 유전자의 상호작용에 관한 연구의 필요성이 제기되고 있다. 본 연구에서는 C2C12 myotube에서 IGF-I이 SOCS-3 유전자 발현에 미치는 영향에 대해 알아보기 위해 4일간 분화시킨 C2C12 myotube에 IGF-I을 다양한 농도(0-200 ng/ml) 및 시간(3-72 시간)에 따라 처리하였다. 그 결과 IGF-I이 SOCS-3 유전자의 단백질 발현을 시간 의존적으로 유의하게 증가시켰으며, 3 시간에서 mRNA 발현을 증가시키고, 시간이 지남에 따라 긴 시간에서는 농도 의존적으로 발현이 감소하였음을 알 수 있었다. 또한 면역형광 염색을 통해 IGF-I이 myotube에서 SOCS-3의 단백질을 발현 시켰음을 뚜렷하게 관찰 할 수 있었다. 위 결과들을 바탕으로 본 연구에서는 IGF-I의 처리가 분화된 근육 세포인 C2C12 myotube에서 SOCS-3 유전자 발현에 유의한 영향을 미쳤음을 증명하였다. 이러한 결과는 선행연구에서 보고한 운동이 SOCS-3 유전자 발현을 증가시킴에 있어서 IGF-I이 중추적인 역할을 한 것으로 생각된다. 그러나 IGF-I에 의한 SOCS-3 유전자 발현 조절 기전에 있어 관련 신호 전달체계 및 골격근 관련 유전자 발현에 미치는 영향에 관한 연구는 보다 더 이루어져야 할 것이라 사료된다.

• 생명과학회지
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• 제26권4호
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• pp.387-397
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• 2016

본 연구는 17-DMAG이 골격근에서 autophagy에 관여하는 가를 조사하기 위해, C2C12세포와 마우스 골격근에서 17-DMAG (Hsp90 억제제/Hsp72 활성제)을 처치하는 그룹과 autophagy 억제제(Bafilomycin 또는 colchicine)를 처치하는 그룹과 처치하지 않는 그룹을 동시에 두고 autophagy flux를 측정하였다. C2C12 배양세포에서 17-DMAG이 Hsp90 억제/hsp72 활성화시켰으며 Akt-mTOR 신호체계를 유의하게 감소시켰지만(p<0.05) autophagy marker 단백질인 LC3 II와 p62를 증가시키지 않았다. in vivo 모델의 경우 17-DMAG 처치가 배양세포에서 발견된 것처럼 Hsp90억제/hsp72를 활성화시켰고 Akt-mTOR 신호체계를 유의하게 감소시켰다(p<0.05). 반면 LC3 II와 p62 단백질 수준은 autophagy 억제제(colchicine) 처치 수준보다 더 높게 증가되었다. 이는 17-DMAG이 골격근에서 autophagy를 증가시키지만 C2C12 배양세포에서는 autophagy의 활성화가 제한적임을 암시한다. 현재 이러한 in vitro와 in vivo 모델에서의 차이는 불분명하다.

• 한국전문물리치료학회지
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• 제14권1호
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• pp.28-36
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• 2007

The aim of this study was to identify the effect of suspension unloading (SU) and electrical stimulation upon the development of neonatal muscular system. For this study, the neonatal rats were randomly divided into three groups: a control group, an experimental group I, and an experimental group II. The SU for experimental group I and II was applied from postnatal day (PD) 5 to PD 30. The electrical stimulation for soleus muscle of experimental group IIwas applied from PD 16 to PD 30 using neuromuscular electrical stimulation (NMES), which gave isometric contraction with 10 pps for 30 minutes twice a day. In order to observe the effect of SU and ES, this study observed myocyte enhancer factor 2C (MEF2C) and vascular endothelial growth factor (VEGF) immunoreactivity in the soleus muscles at PD 15 and PD 30. In addition, the motor behavior test was performed through footprint analysis at PD 30. The following is the result. At PD 15, the soleus muscles of experimental group Iand II had significantly lower MEF2C, VEGF immunoreactivity than the control group. It proved that microgravity conditions restricted the development of the skeletal muscle cells at PD 15. At PD 30, soleus muscles of the control group and experimental group II had significantly higher MEF2C, VEGF, immunoreactivity than experimental group I. It proved that the NMES facilitated the development of the skeletal muscle cells. At PD 30, it showed that SU caused the decrease in stride length of parameter of gait analysis and an increase in toe-out angle, and that the NMES decreased these variations. These results suggest that weight bearing during neonatal developmental period is essential for muscular development. They also reveal that NMES can encourage the development of muscular systems by fully supplementing the effect of weight bearing, which is an essential factor in the neonatal developmental process.

• The Journal of Korean Physical Therapy
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• 제19권4호
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• pp.1-14
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• 2007

Background: It is generally accepted that skeletal muscle contraction is triggered by nerve impulse and intracellular $Ca^{2+}\;([Ca^{2+}]_i)$ released from intracellular $Ca^{2+}$ stores such as sarcoplasmic reticulum (SR). Specifically, this process, called excitation-contraction (E-C) coupling, takes place at intracellular junctions between the plasma membrane, the transverse (T) tubule L-type $Ca^{2+}$ channel (dihydropyridine-sensitive L-rype $Ca^{2+}$ channel, DHPR, also called tetrads), and the SR $Ca^{2+}$ release channel (ryanodine-sensitive $Ca^{2+}$ release channel, RyR, also called feet) of internal $Ca^{2+}$ stores in skeletal muscle cells. Furthermore, it has been reported that the $Ca^{2+-}$ dependent and -independent contraction determine the expression of skeletal muscle genes, thus providing a mechanism for tightly coupling the extent of muscle contraction to regulation of muscle plasticity-related excitation-transcription (E-T) coupling. Purpose: Expression and activity of plasticity-associated enzymes in gastrocnemius muscle strips have not been well studied, however. Methods: Therefore, in this study the expression and phosphorylation of E-C and E-T coupling-related mediators such as protein kinases, ROS(reactive oxygen species)- and apoptosis-related substances, and others in gastrocnemius muscles from rats was examined. Results: I found that expression and activity of MAPKs (mitogen-activated protein kinases, ERK1/2, p38MAPK, and SAPK/JNK), apoptotic proteins (cleaved caspase-3, cytochrome c, Ref-1, Bad), small GTP-binding proteins (RhoA and Cdc42), actin-binding protein (cofilin), PKC (protein kinase C) and $Ca^{2+}$ channel (transient receptor potential channel 6, TRPC6) was observed in rat gastrocnemius muscle strips. Conclusion: These results suggest that MAPKs, ROS- and apoptosis-related enzymes, cytoskeleton-regulated proteins, and $Ca^{2+}$ channel may in part functionally import in E-C and E-T coupling from rat skeletal muscles.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.158-158
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• 2015

Myoblast are myogenic precursors that proliferate, activate, and differentiate on muscle injury to sustain the regenerative capacity of skeletal muscle; The neuronal isoform of nitric oxide synthase (nNOS, termed also NOS-I) is expressed in normal adult skeletal muscle, suggesting important functions for Nitric oxide (NO) in muscle biology1,2,3. However, the expression and subcellular localization of NO in muscle development and myoblast differentiation are largely unknown. In this study, we examined effects of the nitric oxide generated by a microwave plasma torch, on proliferation/differentiation of rat myoblastic L6 cells. Experimental data pertaining to nitric oxide production are presented in terms of the oxygen input in units of cubic centimetres per minute. The various levels of nitric oxide are observed depending on the flow rate of nitrogen gas, the ratio of oxygen gas, and the microwave power4. In order to evaluate the potential of nitric oxide as an activator of cell differentiation, we applied nitric oxide generated from the microwave plasma torch to L6 skeletal muscles. Differentiation of L6 cells into myotubes was significantly enhanced the differentiation after nitric oxide treatment. Nitric oxide treatment also increase the expression of myogenesis marker proteins and mRNA level, such as myogenin and myosin heavy chain (MHC), as well as cyclic guanosine monophosphate (cGMP), However during the myotube differentiation we found that NO activate oxidative stress signaling erks expression. Therefore, these results establish a role of NO and cGMP in regulating myoblast differentiation and elucidate their mechanism of action, providing a direct link with oxidative stress signalling, which is a key player in myogenesis. Based on these findings, nitric oxide generated by plasma can be used as a possible activator of cell differentiation and tissue regeneration.