Publications by authors named "Kwang Pyo Lee"

The metazoan lifespan is determined in part by a complex signaling network that regulates energy metabolism and stress responses. Key signaling hubs in this network include insulin/IGF-1, AMPK, mTOR, and sirtuins. The Hippo/Mammalian Ste20-like Kinase1 (MST1) pathway has been reported to maintain lifespan in Caenorhabditis elegans, but its role has not been studied in higher metazoans.

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Susceptibility to cartilage degeneration increases in an age-dependent manner and older cartilage exhibits increased catabolic factor expression leading to osteoarthritis (OA). While inhibition of cellular senescence can prevent age-related diseases, the understanding of the regulators governing cartilage senescence and the potential for senolytic intervention remains limited. Here, in vitro and in vivo results are reported, demonstrating for the first time that the transcriptional regulator, ZMIZ1, is upregulated in aged and OA cartilage, and that it acts through GATA4 to accelerate chondrocyte senescence and trigger cartilage deterioration.

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Cells regulate gene expression through various RNA regulatory mechanisms, and this regulation often becomes less efficient with age, contributing to accelerated aging and various age-related diseases. Nonsense-mediated mRNA decay (NMD), a well-characterized RNA surveillance mechanism, degrades aberrant mRNAs with premature termination codons (PTCs) to prevent the synthesis of truncated proteins. While the role of NMD in cancer and developmental and genetic diseases is well documented, its implications in human aging remain largely unexplored.

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Muscle aging is a complex physiological process that leads to the progressive decline in muscle mass and function, contributing to debilitating conditions in the elderly such as sarcopenia. In recent years, non-coding RNAs (ncRNAs) have been increasingly recognized as major regulators of muscle aging and related cellular processes. Here, we comprehensively review the emerging role of ncRNAs, including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), in the regulation of muscle aging.

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Background: Low back pain is a general phenomenon of aging, and surgery is an unavoidable choice to relieve severe back pain. The discarded surgical site during surgery is of high value for muscle and muscle-related research. This study investigated the age-dependent properties of patients' paraspinal muscles at the cellular level.

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Exercise and caloric restriction (CR) significantly increase longevity across a range of species and delay aging-related losses in organ function. Although both interventions enhance skeletal muscle function, the molecular mechanisms underlying these associations are unknown. We sought to identify genes regulated by CR and exercise in muscle, and investigate their relationship with muscle function.

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Despite the introduction of a diagnostic code and acceptance of a diagnostic process for sarcopenia as a new health technology in Korea, many practitioners remain unfamiliar with the evaluation of sarcopenia. Thus, the Korean Working Group on Sarcopenia (KWGS) developed clinical practice guidelines for the diagnosis of sarcopenia in older Korean adults. A two-phase Delphi interview comprising 19 questions was conducted with 40 expert panelists, 22 of whom participated in the first round between June and August 2022.

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Dietary restriction (DR) delays aging and the onset of age-associated diseases. However, it is yet to be determined whether and how restriction of specific nutrients promote longevity. Previous genome-wide screens isolated several Escherichia coli mutants that extended lifespan of Caenorhabditis elegans.

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Skeletal muscle communicates with other organs via myokines, which are secreted by muscle during exercise and exert various effects. Despite much investigation of the exercise, the underlying molecular mechanisms are still not fully understood. Here, we applied an in vitro exercise model in which cultured C2C12 myotubes were subjected to electrical pulse stimulation (EPS), which mimics contracting muscle.

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Objective: Glucagon in mammals and its homolog (adipokinetic hormone [AKH] in ) are peptide hormones which regulate lipid metabolism by breaking down triglycerides. Although regulatory mechanisms of glucagon and AKH expression have been widely studied, post-transcriptional gene expression of glucagon has not been investigated thoroughly. In this study, we aimed to profile proteins binding with messenger RNA (mRNA) in mouse and mRNA in Drosophila.

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Sarcopenia is the age-related loss of muscle mass and function and no pharmacological medication has been approved for its treatment. We established an atrogin-1/MAFbx promoter assay to find drug candidates that inhibit myotube atrophy. Alverine citrate (AC) was identified using high-throughput screening of an existing drug library.

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Sarcopenia is a syndrome characterized by progressive loss of muscle mass and function during aging. Although mitochondrial dysfunction and related metabolic defects precede age-related changes in muscle, their contributions to muscle aging are still not well known. In this study, we used a Drosophila model to investigate the role of lipophorin receptors (LpRs), a Drosophila homologue of the mammalian very low-density lipoprotein receptor (VLDLR), in mitochondrial dynamics and muscle aging.

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Cancer cachexia is a highly debilitating condition characterized by weight loss and muscle wasting that contributes significantly to the morbidity and mortality of pancreatic cancer. The factors that induce cachexia in pancreatic cancer are largely unknown. We previously showed that pancreatic adenocarcinoma upregulated factor (PAUF) secreted by pancreatic cancer cells is responsible for tumor growth and metastasis.

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Sarcopenia is characterized by decreased skeletal muscle mass and function with age. Aged muscles have altered lipid compositions; however, the role and regulation of lipids are unknown. Here we report that FABP3 is upregulated in aged skeletal muscles, disrupting homeostasis via lipid remodeling.

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Gut microbes play diverse roles in modulating host fitness, including longevity; however, the molecular mechanisms underlying their mediation of longevity remain poorly understood. We performed genome-wide screens using 3,792 mutants and identified 44 mutants that modulated longevity. Three of these mutants modulated longevity via the bacterial metabolite methylglyoxal (MG).

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Background: The microRNAs (miRNAs) down-regulated in aged mouse skeletal muscle were mainly clustered within the delta-like homologue 1 and the type III iodothyronine deiodinase (Dlk1-Dio3) genomic region. Although clustered miRNAs are coexpressed and regulate multiple targets in a specific signalling pathway, the function of miRNAs in the Dlk1-Dio3 cluster in muscle aging is largely unknown. We aimed to ascertain whether these miRNAs play a common role to regulate age-related muscle atrophy.

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Muscle fibers are generally formed as multinucleated fibers that are differentiated from myoblasts. Several reports have identified transcription factors and proteins involved in the process of muscle differentiation, but the roles of microRNAs (miRNAs) in myogenesis remain unclear. Here, comparative analysis of the miRNA expression profiles in mouse myoblasts and gastrocnemius (GA) muscle uncovered miR-3074-3p as a novel miRNA showing markedly reduced expression in fully differentiated adult skeletal muscle.

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The blood exhibits a dynamic flux of proteins that are secreted by the tissues and cells of the body. To identify novel aging-related circulating proteins, we compared the plasma proteomic profiles of young and old mice using tandem mass spectrometry. The expression of 134 proteins differed between young and old mice.

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Skeletal muscle is one of the major organs responsible for body movements and metabolism making up approximately 40% of the total body mass. During aging, skeletal muscle exhibits a degenerative age-associated decline in mass and function termed sarcopenia. This age-associated dysfunction of skeletal muscle is a major criterion of morbidity, mortality, and overall declines of quality of life in the elderly people.

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Sarcopenia is a gradual loss of skeletal muscle mass and function with aging. Given that sarcopenia has been recognized as a disease entity, effective molecular biomarkers for early diagnosis are required. We recruited 46 normal subjects and 50 patients with moderate sarcopenia aged 60 years and older.

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Age-associated loss of muscle mass and function is a major cause of morbidity and mortality in the elderly adults. Muscular atrophy can also be induced by disuse associated with long-term bed rest or disease. Although miRNAs regulate muscle growth, regeneration, and aging, their potential role in acute muscle atrophy is poorly understood.

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NADPH oxidase (NOX) generates reactive oxygen species (ROS) and has been suggested to mediate cell proliferation in some cancers. Here, we show that an increase in the expression of NOX5 long form (NOX5-L) is critical for tumor progression in breast tumor tissues. Immunostaining of clinical samples indicated that NOX5 was overexpressed in 41.

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Skeletal muscle mass and power decrease with age, leading to impairment of mobility and metabolism in the elderly. Ca signaling is crucial for myoblast differentiation as well as muscle contraction through activation of transcription factors and Ca-dependent kinases and phosphatases. Ca channels, such as dihydropyridine receptor (DHPR), two-pore channel (TPC) and inositol 1,4,5-triphosphate receptor (ITPR), function to maintain Ca homeostasis in myoblasts.

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The periodontium undergoes age-related cellular and clinical changes, but the involved genes are not yet known. Here, we investigated age-related genetic changes in gingiva at the transcriptomic level. Genes that were differentially expressed between young and old human gingiva were identified by RNA sequencing and verified by real-time PCR.

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Pancreatic cancer is characterized by an immunosuppressive tumor microenvironment (TME) with a profound immune infiltrate populated by a significant number of myeloid-derived suppressor cells (MDSCs). MDSCs have been increasingly recognized for their role in immune evasion and cancer progression as well as their potential as a target for immunotherapy. However, not much is known about the mechanisms regulating their behavior and function in the pancreatic TME.

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