Jong-Hee Kim

• PhD
• Professor (Associate) at Hanyang University

Duchenne muscular dystrophy (DMD) is a common and devastating type of childhood-onset muscular dystrophy, attributed to an X-linked defect in the gene that encodes dystrophin. Myopathy with DMD is most pronounced in the diaphragm muscle and fast-twitch limb muscles and is dependent upon susceptibility to damage, inflammatory cell infiltration, and...

Aging is characterized by a progressive loss of muscle mass and impaired contractility (e.g., decline in force, velocity, and power). Although the slowing of contraction speed in aging muscle is well described, the underlying molecular mechanisms responsible for the decrement in speed are unknown. Myosin heavy chain (MHC) isoforms are the primary m...

Background: Pure frailty and obese frailty are common types of frailty syndrome. However, the overlapping and distinct characteristics between pure frailty and obese frailty remain unclear. This study aims to reveal the overlapping/distinct physical and biological phenotypes of pure frailty and obese frailty, providing theoretical support for their...

Background Obesity is a significant global health issue and a risk factor for numerous diseases. Ferroptosis, an iron-dependent regulated cell death, is triggered by iron overload and the excessive accumulation of lipid peroxidation mediated by reactive oxygen species. Recent research has identified a strong association between ferroptosis and obes...

Background Obesity causes metabolic dysregulation and contributes to various diseases, with autophagy playing a pivotal role in this process. Autophagy, a cellular recycling mechanism, is influenced by factors beyond obesity, like caloric restriction (CR) and CR combined with exercise (CR+Ex), which modulate autophagy in obesity management. However...

Background Aging-induced frailty syndrome leads to significant functional decline in skeletal muscle. The specific histological changes in skeletal muscle due to frailty syndrome are not well-defined. While the positive effects of exercise on skeletal muscle histology are documented, its preventive impact on frailty syndrome requires further explor...

Background Obesity is a significant global health issue and a risk factor for numerous diseases. Ferroptosis, an iron-dependent regulated cell death, is triggered by iron overload and the excessive accumulation of lipid peroxidation mediated by reactive oxygen species. Studies has identified a strong association between ferroptosis and obesity. Add...

Background: Ferroptosis is a recently discovered mode of cell death that results from lipid peroxidation. Many studies have found that obesity, calorie restriction, and exercise can affect oxidative stress, which can have an impact on the activity of ferroptosis regulatory proteins. Although the ferroptosis regulatory proteins in other organs and/o...

Background: Autophagy is a complex degradation process responsible for maintaining the metabolic homeostasis of skeletal muscle. The influence of obesity on autophagy regulation in skeletal muscle remains a topic of debate. Both calorie restriction and exercise have shown beneficial effects on obesity. However, despite the ongoing debate, several s...

Background: High-fat diet-induced obesity brings challenges to modern society. Obesity leads to a reduced physical performance, in part, due to compromised aerobic capacity, strength, and power in skeletal muscle. Evidence suggests that obesity-related morphological adaptation such as decreased muscle fiber size and fiber number, and increased extr...

Cycling is a popular sport, and the cycling population and prevalence of related injuries and diseases increase simultaneously. Iliotibial band friction syndrome is a common chronic overuse injury caused by repetitive knee use in cycling. Self-myofascial release using foam rollers is an effective intervention for this syndrome; however, studies rep...

Background：It is well known that age and gender have a great influence on the constitution of exercise capacity and body composition. Differences in aging and gender have both independent and interactive effects on exercise capacity and body composition. Exercise capacity and body composition are highly correlated and can influence each other. Endu...

Background: Aging leads to a loss of skeletal muscle mass and strength, termed sarcopenia. Obesity, accompanying sarcopenia, is commonly preceded by overweight. The purpose of this study was to investigate the changes in morphology in different muscles with age and examine the effect of endurance exercise (EE) on sarcopenic overweight.

This study aimed to investigate the effect of a treadmill exercise on hematological and serum biochemical parameters and the expression of immune-related cytokine genes in leukocytes. For the experiment, six healthy adult dogs were divided into exercise and control groups. The exercise group performed an endurance exercise three times a week for fo...

PURPOSE Frailty is a geriatric syndrome that impairs the health and quality of life of older adults. While unintended weight loss is known to be a primary risk factor for frailty, obesity has also been closely associated with frailty. Combined exercise is thought to be an effective way of resolving obesity and frailty, but studies demonstrating the...

Exercise has been suggested as a powerful intervention for health care and fitness management in humans; however, few studies have demonstrated the benefits of exercise training in dogs. The purpose of this study was to examine the effects of exercise training on heart rate (HR), bone mineral density (BMD), muscle volume (MV), and hematological and...

There are growing attention and interdisciplinary efforts for One Health to attain optimal health and well-being for humans and animals. Exercise has been suggested as a powerful intervention for health care and fitness management in humans; however, few studies have demonstrated the beneficial effect of exercise on dogs. The purpose of this study...

Purpose: Exercise is a fundamental way to maintain and improve health and physical fitness. Many human studies have demonstrated the beneficial effects of exercise on various biological parameters. However, studies investigating the effects of exercise in dogs are limited. This review summarized the current data from studies that examined the effe...

Duchenne muscular dystrophy (DMD) is a severe muscle-wasting disease. Although the lack of dystrophin protein is the primary defect responsible for the development of DMD, secondary disease complications such as persistent inflammation contribute greatly to the pathogenesis and the time-dependent progression of muscle destruction. The immunoproteas...

Purpose: The NLRP3 inflammasome is a critical player in vascular pathology as it regulates caspase-1-mediated interleukin (IL)-1β processing. Physical activity ameliorate obesity-induced inflammation and vascular dysfunction, but the mechanisms responsible for these positive changes are incompletely understood. Here, the protective effect of physi...

Although proper exercise training induces positive physiological effects, improper exercise can lead to injury, fatigue, and poor performance. The frequency, intensity, time/duration, type, volume, and progression (FITT-VP) are the essential components of exercise training to maintain or improve physical fitness and health. The purpose of this stud...

Purpose The purpose of this study was to investigate changes of the cardiovascular system by comparing heart rate (HR) and blood responses to exercise in younger and older adult dogs and to verify the value of dogs as aging model in exercise science research. Methods A total of 11 healthy beagles were divided into 2 groups according to age: younger...

Purpose: The purpose of this study was to identify the relationships between muscle mass, muscle strength, and physical and cognitive functions and to examine the effects of resistive Theraband® exercise on sarcopenia-associated variables in the older population. Methods: A total of 28 elderly women (age: 69.90 ± 0.8 years) participated in this...

Disuse induces adaptations in skeletal muscle, which lead to muscle deterioration. Hindlimb-unloading (HU) is a well-established model to investigate cellular mechanisms responsible for disuse-induced skeletal muscle dysfunction. In myosin heavy chain (MHC) type IIB fibers HU induces a reduction in contraction speed (Vo) and a reduction in the rela...

Percent of MLC3f/MLC1f (A), MLC3f/MLC2f (B), and MLC3f/(MLC1f+MLC3f) (C) in single MHC type IIB fibers from SM muscles following HU (7days) and a 3.75 x 1011 ifu/ml rAd-MLC3f injection. Experimental groups include: CON, (n = 74); HU, (n = 44); HUM-1D, the rAd-MLC3f injection was administered one-day before the initiation of HU (eight-day before sac...

Percent of MLC3f/MLC1f (A), MLC3f/MLC2f (B), and MLC3f/(MLC1f+MLC3f) (C) in single MHC type IIB fibers from SM muscles following HU (7days) and a 5 x 1011 ifu/ml rAd-MLC3f injection. Experimental groups include: CON, (n = 74); HU, (n = 44); HUM-1D, the rAd-MLC3f injection was administered one-day before the initiation of HU (eight-day before sacrif...

Percent of MLC3f/MLC1f (A), MLC3f/MLC2f (B), and MLC3f/(MLC1f+MLC3f) (C) in single MHC type IIB fibers from SM muscles following HU (7days) and a 2.50 x 1011 ifu/ml rAd-MLC3f injection. Experimental groups include: CON, (n = 74); HU, (n = 44); HUM-1D, the rAd-MLC3f injection was administered one-day before the initiation of HU (eight-day before sac...

Introduction: We aimed to evaluate the relationship between the VDR expression in the muscle cell and the muscle mass in women with a distal radius fracture (DRF). Methods: We prospectively recruited 45 women over 50 years of age (mean age, 66 years) with DRF and acquired biopsy of the forearm flexor muscle. The muscle cross-sectional area (CSA)...

PURPOSE The purpose of this study was to examine the effect of trampoline exercise on functional performance in persons with chronic ankle instability. METHODS A total of 24 college students were assigned to one of three groups: control (CON), ankle sprained without chronic ankle instability (NAI), and ankle sprained with chronic ankle instability...

Many basic movements of living organisms are dependent on muscle function. Muscle function allows for the coordination and harmonious integrity of movement that is necessary for various biological processes. Gross and fine motor skills are both regulated at the micro-level (single muscle fibre level), controlled by neuronal regulation, and it is th...

Endoplasmic reticulum (ER) stress, which is highly associated with cardiovascular disease, is triggered by a disturbance in ER function because of protein misfolding or an increase in protein secretion. Prolonged disruption of ER causes ER stress and activation of the unfolded protein response (UPR) and leads to various diseases. Eukaryotic cells r...

[Purpose] The purpose of this review is to discuss current views regarding the acute effects of phytochemicals, exercise, and exercise plus phytochemicals on fatty acid oxidation. [Methods] Data acquired from human and animal studies were comprehensively assessed to determine the single and combined effects of phytochemicals and exercise on fatty...

Fibrosis of the aging heart impedes cardiac function and increases the risk of arrhythmias and heart disease. Previously, we demonstrated that exercise-induced reduction of collagen I in the aging heart was linked to a suppression of oxidative stress and transforming growth factor-beta (TGF-ß). The renin-angiotensin II system (RAS) increases oxidat...

Apoptosis plays an important role in atrophy and sarcopenia in skeletal muscle. Recent evidence suggests that insufficient heat shock proteins (HSPs) may contribute to apoptosis and muscle wasting. In addition, long-term caloric restriction (CR) and lifelong wheel running exercise (WR) with CR provide significant protection against caspase-dependen...

Quantification of key outcome measures in animal models of aging is an important step preceding intervention testing. One such measurement, skeletal muscle power generation (force * velocity), is critical for dynamic movement. Prior research focused on maximum power (P max), which occurs around 30–40 % of maximum load. However, movement occurs over...

Contractility of the heart is impaired with advancing age via mechanical remodeling, as myocytes are lost through apoptosis and collagenous fibers accumulate. Exercise training confers protection against fibrosis and apoptosis in the aging heart, but the mechanisms remain poorly understood. We recently reported that exercise training elevates Mn is...

We tested the hypothesis that non-weightbearing-induced muscle weakness (i.e. specific force) results from decreases in myosin protein quantity (i.e., myosin content per half-sarcomere and the ratio of myosin to actin) and quality (i.e., force per half-sarcomere and population of myosin heads in the strong-binding state during muscle contraction) i...

Developing a scoring system based on physiological and functional measurements is critical to test the efficacy of potential interventions for sarcopenia and frailty in aging animal models; therefore, the aim of this study was to develop a neuromuscular healthspan scoring system (NMHSS). We examined three ages of male C57BL/6 mice: adults (6-7 mont...

Aging results in accumulation of extracellular matrix proteins and impairment of cardiac function. Oxidative stress is a potential mechanism in age‐associated cardiac fibrosis. We have previously show exercise training reduces fibrosis and expression of transforming growth factor‐beta (TGF‐ß1) in the aging heart, concomitant with a reduction in oxi...

The purpose of this study was to examine how non‐weightbearing (NWB) alters power generation of myosin heavy chain (MHC) IIB, IIXB, and IIX fibers from the plantaris (PL), tibialis anterior (TA), extensor digitorum longus (EDL) muscles and MHCI fibers from the soleus (SOL) muscle. NWB was achieved in rats by the hindlimb suspension technique (1 to...

Duchenne muscular dystrophy (DMD) is a degenerative skeletal muscle disease that makes walking and breathing difficult. DMD is caused by an X-linked (Xp21) mutation in the dystrophin gene. Dystrophin is a scaffolding protein located in the sarcolemmal cytoskeleton, important in maintaining structural integrity and regulating muscle cell (muscle fib...

We examined the effects of mild therapeutic exercise during a period of inactivity on size and contractile functions of myosin heavy chain (MHC) type I (n=204) and type II (n=419) single fibers from the medial gastrocnemius in three age groups. Young adult (5-12mo.), middle-aged (24-31mo.) and old (32-37mo.) F344BNF1 rats were assigned to one of th...

The purpose of this study was to investigate the effects of mild therapeutic exercise (treadmill) in preventing the inactivity-induced alterations in contractile properties (e.g., power, force, and velocity) of type I soleus single fibers in three different age groups. Young adult (5- to 12-mo-old), middle-aged (24- to 31-mo-old), and old (32- to 4...

Extreme disuse and spaceflight elicit rapid skeletal muscle atrophy, accompanied by elevated proinflammatory signaling and impaired stress response proteins (e.g., heat shock proteins (HSP), insulin-like growth factor 1 (IGF-1)). Recovery of muscle mass is delayed during the early stage of reloading after prolonged unloading, with a concomitant imp...

Extraocular muscle (EOM) myofibers do not fit the traditional fiber typing classifications normally used in noncranial skeletal muscle, in part, due to the complexity of their individual myofibers. With single skinned myofibers isolated from rectus muscles of normal adult rabbits, force and shortening velocity were determined for 220 fibers. Each f...

Duchenne muscular dystrophy (DMD) elicits damage and inflammation in respiratory (e.g., diaphragm) and limb muscles, and is a caused by an x‐linked mutation in the gene encoding for dystrophin, a scaffolding protein of the dystroglycan complex (DGC). While reactive oxygen species (ROS) amplify damage and inflammation, mechanistic links remain elusi...

Fibrosis in the aging heart impedes diastolic filling and increases arrhythmias. Previously, we demonstrated that exercise training (ET) reduced collagen I fibrosis and oxidative stress in the aging heart. Recent studies show that NAD(P)H oxidases (Nox) could be an important source of oxidative stress during the aging process, activated by renin‐an...

Aging impairs function in the nonischemic heart and is associated with mechanical remodeling. This process includes accumulation of collagen (i.e., fibrosis) and dysregulation of active matrix metalloproteinases (MMPs). Exercise training (ET) improves cardiac function, but the pathways of protection remain poorly understood. Young (3 mo) and old (3...

INTRODUCTION:: Extreme disuse and spaceflight elicit rapid skeletal muscle atrophy, accompanied by elevated pro-inflammatory signaling and impaired stress response proteins (e.g., heat shock proteins, IGF-1). Recovery of muscle mass is delayed during the early stage of reloading after prolonged unloading, with a concomitant impairment of HSP70 and...

Previous reports indicate that reactive oxygen species (ROS) may modulate contractility in skeletal muscle. Although Ca(2+)-sensitivity of the contractile apparatus appears to be a primary site of regulation, dihydropyridine receptor (DHPR or L-type Ca(2+) channels) and calcium efflux in isolated sarcoplasmic reticulum (SR) vesicles appear to be re...

The effects of exercise training on the nitric oxide synthase (NOS) isoform profile in aging fast-twitch (white gastrocnemius [WG]) and slow-twitch (soleus [SOL]) muscle have not been investigated. Six-month and 27-month male Fischer-344 rats were divided into the following groups: young sedentary (YS), young treadmill exercise trained for 12 weeks...

While the stress response to heat and exercise is limited in the heart with progressive aging, recent data indicate that acute or short-term exercise upregulates the Mn isoform of superoxide dismutase (MnSOD), which may provide protection against ischemia-reperfusion injury and cell death by reducing oxidative stress. Growing evidence indicates tha...

Aging is characterized by a progressive loss of muscle mass and muscle fiber atrophy or ¡°sarcopenia.¡ ±Although the molecular mechanisms responsible for sarcopenia have not been completely understood, recent literature indicates that mitochondrial dysfunction and apoptosis play critical roles in sarcopenia. Regular exercise and caloric restriction...

Exercise may reduce oxidative stress, mitochondrial dysfunction, and mitochondrial caspase‐dependent apoptosis with age. However, it is unclear whether the caspase‐independent apoptosis via EndonucleaseG (EndoG) and Apoptosis Inducing Factor (AIF) is affected by exercise in aging skeletal muscle. We hypothesize that exercise will attenuate apoptosi...

Duchenne muscular dystrophy (DMD) is characterized by devastating muscle degeneration associated with oxidative stress, loss of contractile tissue, muscle atrophy, muscle weakness and increased fibrosis in respiratory and locomotor muscles. We tested the hypothesis that protection against oxidative stress via the catalase/superoxide dismutase mimet...

Long duration spaceflight missions cause skeletal muscle atrophy in astronauts. We hypothesize that neuronal Nitric Oxide Synthase (nNOS) and dystrophin translocate from the sarcolemma to the sarcoplasm following 48‐hrs of simulated microgravity as compared to ground controls. Eight Fisher‐344 rats underwent 48‐hour simulated microgravity using the...

Aging is associated with a progressive increase in collagen (i.e., fibrosis) in the aging heart. Fibrosis is associated with a stiffening of the heart and a decrease in heart function. Previous data (Kwak, 2008) showed that matrix metalloproteinase (MMP) activity in the aging heart is decreased linked to an elevation TIMP-1 (tissue inhibitor of MMP...

Exercise may have protective factors in reducing oxidative stress, mitochondrial dysfunction and mitochondrial caspase-dependent apoptosis with aging. It is presently unclear whether the caspase-independent apoptosis via EndonucleaseG (EndoG) and Apoptosis Inducing Factor (AIF) translocation from the mitochondria to the nucleosome is effected by ex...

Duchenne muscular dystrophy (DMD) is characterized by devastating muscle degeneration that includes oxidative stress, loss of contractile tissue, muscle weakness and increased fibrosis in respiratory muscles (e.g., diaphragm). The mdx mice diaphragm undergoes a progressive degeneration similar to that occurring in patients with DMD. We showed that...

Muscle atrophy is a highly prevalent condition among older adults, and results from reduced muscle mass and fiber cross-sectional area. Resistive exercise training and moderate (30-40%) caloric restriction may reduce the rate of sarcopenia in animal models. We tested the hypothesis that lifelong, voluntary exercise combined with mild (8%) caloric r...

Duchenne muscular dystrophy (DMD) is the most devastating type of MD resulting in oxidative stress, muscle damage, weakness, and wasting in locomotor and respiratory (e.g., diaphragm) muscle. Previously, we showed that apocynin, a NAD(P)H oxidase inhibitor, protects against reduction in diaphragm mass, oxidative capacity, and apoptosis in 3–4 week...

Previously our laboratory demonstrated that exercise training (ET) attenuated age‐induced muscle fiber atrophy, caspase‐3 cleavage, and pro‐apoptotic Bcl‐2 signaling in the rat white gastrocnemius. However, cleavage of caspase‐3 and apoptosis may also be stimulated by inflammatory cytokines (e.g. TNF‐α), the fas/cytokine pathway, and ER/Ca ²⁺ stres...

It is now a widely accepted belief that oxidative stress and apoptosis contribute to muscle atrophy in a number of pathologies including severe disuse (e.g., hindlimb unloading (HU), mechanical ventilation), denervation, and congestive heart failure. Severe disuse induces skeletal muscle atrophy through activation of caspase‐3, apoptosis, calpains,...

Recently, we showed that in the rat heart exercise training (ET) reduces age‐induced oxidative stress, apoptosis, caspase‐3 cleavage, and upstream modulation of mitochondrial Bcl‐2 signaling by increasing anti‐apoptotic Bcl‐2 and decreasing pro‐apoptotic Bax. BAG‐4 and thioredoxin‐2 (Trx2) are mitochondrial survival proteins that promote protection...