• Asian-Australasian Journal of Animal Sciences
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• v.32 no.3
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• pp.350-356
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• 2019

Objective: To examine the regulatory effects of exercise on myokine expression in horse skeletal muscle cells, we compared the expression of several myokine genes (interleukin 6 [IL-6], IL-8, chemokine [C-X-C motif] ligand 2 [CXCL2], and chemokine [C-C motif] ligand 4 [CCL4]) after a single bout of exercise in horses. Furthermore, to establish in vitro systems for the validation of exercise effects, we cultured horse skeletal muscle cells and confirmed the expression of these genes after treatment with hydrogen peroxide. Methods: The mRNA expression of IL-6, IL-8, CXCL2, and CCL4 after exercise in skeletal muscle tissue was confirmed using quantitative-reverse transcriptase polymerase chain reactions (qRT-PCR). We then extracted horse muscle cells from the skeletal muscle tissue of a neonatal Thoroughbred. Myokine expression after hydrogen peroxide treatments was confirmed using qRT-PCR in horse skeletal muscle cells. Results: IL-6, IL-8, CXCL2, and CCL4 expression in Thoroughbred and Jeju horse skeletal muscles significantly increased after exercise. We stably maintained horse skeletal muscle cells in culture and confirmed the expression of the myogenic marker, myoblast determination protein (MyoD). Moreover, myokine expression was validated using hydrogen peroxide ($H_2O_2$)-treated horse skeletal muscle cells. The patterns of myokine expression in muscle cells were found to be similar to those observed in skeletal muscle tissue. Conclusion: We confirmed that several myokines involved in inflammation were induced by exercise in horse skeletal muscle tissue. In addition, we successfully cultured horse skeletal muscle cells and established an in vitro system to validate associated gene expression and function. This study will provide a valuable system for studying the function of exercise-related genes in the future.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.4
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• pp.397-410
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• 2000

Skeletal class III had been classified by the position of the maxilla, the mandible, the maxillary alveolus, the mandibular alveolus and vertical development. This morphologic approach is simple and useful for clinical use, but it is insufficient to permit understanding of the pathophysiology of dysmorphoses. The author hypothesizes that there are different patterns of mutual relation of the skeletal components which have contributed pathologic equilibrium of skeletal class III. The purpose of this study are threefold: 1) to classify skeletal class III in subgroups, which can show the architectural characteristics of the deformity, 2) to analyse the craniofacial architecture of each subgroup on etio-pathogenic basis, and 3) to characterize and visualize the pattern as a prototype. Materials used in this study were lateral cephalograms of 106 skeletal class III adults, which were analysed with modified Delaire's architectural and structural analysis. Linear and angular measurements of the individual subject were obtained and cluster analysis was used for the subgrouping. Data were evaluated for verification of the statistical significances. The following results were obtained. 1. By the modified Delaire's architectural and structural analysis and cluster analysis, skeletal class III adults were classified into 7 clusters and presented as prototypes, which could show the pathophysiology of the skeletal architecture 2. There was significant relationship in measurement variables of each cluster, which could reflect characteristics of the skeletal pattern of growth. 3. The flexure of cranial base had a close relationship to the anterior rotational growth of the maxilla and contributes to understand the etio-pathology of skeletal class III. 4. The proportion of craniospinal area in cranial depth, craniocervical angle and vertical position of point Om had a close relationship to rotational growth of the mandible and direction of condylar growth. They contribute to understand the etio-pathology of skeletal class III. In summary, the cranium and the craniocervical area must be considered in diagnosis and treatment planning of dentofacial deformity. And the occlusal plane can be considered as a representative which shows the mutual relationships of the skeletal components.

• The korean journal of orthodontics
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• v.20 no.1
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• pp.157-168
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• 1990

This study was undertaken to investigate the interrelationships between the degrees of skeletal maturity of cervical vertebrae and the hand-and-wrist in skeletal Class III malocclusions. In 185 skeletal Class III malocclusions (male 62, female 123) having the lateral cephalogram and hand-wrist radiogram which were taken on the same day, 6 skeletal maturity stages of cervical vertebrae were compared with 11 skeletal maturity indicators of the hand-and-wrist. On the basis of findings of this study, the following results were obtained: 1. The stages of cervical vertebral maturity are one of the methods possible to assess the individual maturity. 2. Mean ages of male and female were obtained in each cervical vertebral stage. 3. Cervical vertebral stages 1 and 2 are considered to the accelerative growth phase, cervical vertebral stages 3 and 4 are corresponded to the peak height velocity, and cervical vertebral stages 5 and 6 were observed to occur during the decelerative phase of growth after peak height velocity in both sexes. 4. In cervical vertebral stages 1, 2, 3, 4, and 5, the degrees of skeletal maturity of cervical vertebrae in males were more retarded than females. 5. There was the high correlation between the degrees of skeletal maturity of cervical vertebrae and hand-and-wrist.

• Molecules and Cells
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• v.24 no.2
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• pp.177-184
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• 2007

Approximately 200 individual skeletal elements, which differ in shape and size, are the building blocks of the vertebrate skeleton. Various features of the individual skeletal elements, such as their location, shape, growth and differentiation rate, are being determined during embryonic development. A few skeletal elements, such as the lateral halves of the clavicle and parts of the skull are formed by a process called intramembranous ossification, whereby mesenchymal cells differentiate directly into osteoblasts, while the majority of skeletal elements are formed via endochondral ossification. The latter process starts with the formation of a cartilaginous template, which eventually is being replaced by bone. This requires co-regulation of differentiation of the cell-types specific for cartilage and bone, chondrocytes and osteoblasts, respectively. In recent years it has been demonstrated that Wnt family members and their respective intracellular pathways, such as non-canonical and the canonical $Wnt/{\beta}$-catenin pathway, play important and diverse roles during different steps of vertebrate skeletal development. Based on the recent discoveries modulation of the canonical Wnt-signaling pathway could be an interesting approach to direct stem cells into certain skeletal lineages.

• Integrative Medicine Research
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• v.2 no.4
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• pp.131-138
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• 2013

The skeletal muscle in our body is a major site for bioenergetics and metabolism during exercise. Carbohydrates and fats are the primary nutrients that provide the necessary energy required to maintain cellular activities during exercise. The metabolic responses to exercise in glucose and lipid regulation depend on the intensity and duration of exercise. Because of the increasing prevalence of obesity, recent studies have focused on the cellular and molecular mechanisms of obesity-induced insulin resistance in skeletal muscle. Accumulation of intramyocellular lipid may lead to insulin resistance in skeletal muscle. In addition, lipid intermediates (e.g., fatty acyl-coenzyme A, diacylglycerol, and ceramide) impair insulin signaling in skeletal muscle. Recently, emerging evidence linking obesity-induced insulin resistance to excessive lipid oxidation, mitochondrial overload, and mitochondrial oxidative stress have been provided with mitochondrial function. This review will provide a brief comprehensive summary on exercise and skeletal muscle metabolism, and discuss the potential mechanisms of obesity-induced insulin resistance in skeletal muscle.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.4
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• pp.992-996
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• 2006

The study examined clinical effect of the 'Sexiang Shuhuo Jing' on serum CK and LDH activities and skeletal muscle ${\alpha}-actin$ mRNA expression concentration 140days after skeletal muscle injury in rats. The clinical research consisted of observing and measuring the serum CK, LDH activities and skeletal muscle ${\alpha}-actin$ mRNA expression, at the time of injury and during recovery. All experimental data were analyzed by repeated measurement with ANOVA on of SPSS(11.5v), accepting level for all significances was above ${\alpha}\;=.05.$ The results were as follows: That skeletal muscle injury in rats there existed a substantial increase serum CK, LDH activities and expression of skeletal muscle ${\alpha}-actin$ mRNA And Sexiang Shuhuo Jing treatment group's serum CK, LDH activities lower and faster recovery than control group. The 1 st day after skeletal muscle injury, Sexiang Shuhuo Jing treatment group's skeletal muscle ${\alpha}-actin$ mRNA expression was much more higher than control group, after 2 day's faster recovery normal level than control group. There existed a substantial increase again serum CK, LDH activities and skeletal muscle ${\alpha}-actin$ mRNA expression 3rd days after injury in control group. But in Sexiang Shuhuo Jing treatment group's can't be found that.

• Biomedical Science Letters
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• v.17 no.4
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• pp.283-289
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• 2011

Our previous study demonstrated that the Korean traditional medicine Gyeongshingangjeehwan (GGEx) activates AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor ${\alpha}$ ($PPAR{\alpha}$) critical for fatty acid oxidation in skeletal muscle and C2C12 skeletal muscle cells. Thus, we examined whether GGEx can reduce lipid accumulation in these cells and tissues. After obese and type 2 diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats were treated with GGEx, we studied the effects of GGEx on skeletal muscle lipid accumulation. The effects of GGEx and/or the AMPK inhibitor compound C on lipid accumulation and expression of AMPK and $PPAR{\alpha}$ were measured in C2C12 skeletal muscle cells. Compared with lean Long-Evans Tokushima Otsuka rats, obese OLETF rats had increased triglyceride droplets. However, administration of GGEx to OLETF rats for 8 weeks significantly decreased triglyceride droplets in skeletal muscle. Consistent with the $in$ $vivo$ data, GGEx inhibited lipid accumulation, the degree of which was comparable to Wy14,643, the potent activator of $PPAR{\alpha}$. GGEx also increased skeletal muscle mRNA levels of AMPK${\alpha}1$, AMPK${\alpha}2$, and $PPAR{\alpha}$. However, compound C inhibited these effects in C2C12 cells. These results suggest that GGEx suppresses skeletal muscle lipid accumulation and this process may be mediated by AMPK and $PPAR{\alpha}$ activation.

• Journal of the Korean Society of Visualization
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• v.20 no.2
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• pp.70-77
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• 2022

Skeletal muscle tissues feature cellular heterogeneity, including differentiated myofibers, myoblasts, and satellite cells. Thanks to the presence of undifferentiated myoblasts and satellite cells, skeletal muscle tissues can self-regenerate after injury. In skeletal muscle regeneration, the collective motions among these cell types must play a significant role, but little is known about the dynamic collective behavior during the regeneration. In this study, we constructed in vitro platform to visualize the migration behavior of skeletal muscle cells in specific conditions that mimic the biochemical environment of injured skeletal muscles. We then visualized the spatiotemporal distribution of stresses arising from the differential collectiveness in the cellular clusters under different conditions. From these analyses, we identified that the heterogeneous population of muscle cells exhibited distinct collective migration patterns in the injury-mimicking condition, suggesting selective activation of a specific cell type by the biochemical cues from the injured skeletal muscles.

• Endocrinology and Metabolism
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• v.37 no.3
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• pp.408-414
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• 2022

Skeletal muscle is now regarded as an endocrine organ based on its secretion of myokines and exerkines, which, in response to metabolic stimuli, regulate the crosstalk between the skeletal muscle and other metabolic organs in terms of systemic energy homeostasis. This conceptual basis of skeletal muscle as a metabolically active organ has provided insights into the potential role of physical inactivity and conditions altering muscle quality and quantity in the development of multiple metabolic disorders, including insulin resistance, obesity, and diabetes. Therefore, it is important to understand human muscle physiology more deeply in relation to the pathophysiology of metabolic diseases. Since monolayer cell lines or animal models used in conventional research differ from the pathophysiological features of the human body, there is increasing need for more physiologically relevant in vitro models of human skeletal muscle. Here, we introduce recent studies on in vitro models of human skeletal muscle generated from adult myogenic progenitors or pluripotent stem cells and summarize recent progress in the development of three-dimensional (3D) bioartificial muscle, which mimics the physiological complexity of native skeletal muscle tissue in terms of maturation and functionality. We then discuss the future of skeletal muscle 3D-organoid culture technology in the field of metabolic research for studying pathological mechanisms and developing personalized therapeutic strategies.

• The korean journal of orthodontics
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• v.20 no.1
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• pp.111-122
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• 1990

To investigate the relationship of skeletal maturity among the normal occlusion group and each malocclusion groups, the author used hand and wrist X-ray of 133 Korean 13 year old boys (normal occlusion 30, Class I malocclusion 35, Class II malocclusion 35 and Class III malocclusion 33) and assessed their skeletal maturity. In this study, fourteen skeletal maturity stages were selected from; Radius, Hamate, Pisiform, Ulnar sesamoid of the metacarpophalangeal joint of the first thumb, proximal phalanges of the first, second and third finger, middle and distal phalanx of the third finger. The difference of skeletal maturity of each malocclusion groups in relative to normal occlusion group and that of each malocclusion groups were analyzed. The findings of this study can be summerized as follows: 1. Average skeletal maturity stage of each groups were MP3cap stage in normal occlusion group, H-2 stage in Class I malocclusion group, midstage between S and H-2 stage in Class II malocclusion group, MP3cap stage in Class III malocclusion group. 2. There was no significant difference in skeletal maturity of Class I malocclusion and Class III malocclusion groups in relative to normal occlusion group. 3. There was significant retardation of skeletal maturity in Class II malocclusion group in relative to normal occlusion group. 4. There was no significant difference in skeletal maturity between Class I and Class II malocclusion groups. 5. There was no significant difference in skeletal maturity between Class I and Class III malocclusion groups. 6. There was significant retardation of skeletal maturity in Class II malocclusion group in relative to Class III malocclusion group.