Publications by authors named "Jin-Ho Chung"

In optical networks, designing optical orthogonal codes (OOCs) with appropriate parameters is essential for enhancing the overall system performance. They are divided into two categories, constant-weight OOCs (CW-OOCs) and variable-weight OOCs (VW-OOCs), based on the number of distinct Hamming weights present in their codewords. This paper introduces a method for constructing VW-OOCs of length kp by using the structure of an integer ring and the Chinese Remainder Theorem.

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Osteopontin (OPN) is a pro-inflammatory protein that influences bone remodelling, wound healing, angiogenesis, allergic inflammation, and skin diseases such as psoriasis, contact dermatitis and skin cancer. However, the role of OPN in the skin remains unclear. Therefore, this study aimed to investigate the role of OPN in the skin, particularly in the context of ultraviolet (UV) irradiation-induced inflammation.

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Background: Overexposure to ultraviolet (UV) radiation accelerates skin aging, resulting in wrinkle formation, reduced skin elasticity, and hyperpigmentation. UV irradiation induces increased matrix metalloproteinases (MMPs) that degrade collagen in the extracellular matrix. Skin aging is also accompanied by epigenetic alterations such as promoter methylation by DNA methyltransferases, leading to the activation or suppression of gene expression.

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Background: ABO blood group antigens (ABH antigens) are carbohydrate chains glycosylated on epithelial and red blood cells. Recent findings suggest reduced ABH expression in psoriasis and atopic dermatitis, a chronic inflammatory skin disease with retained scale. H antigen, a precursor for A and B antigens, is synthesized by fucosyltransferase 1 (FUT1).

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Numerous recent evidence highlights epidemiological connections between rosacea and metabolic disorders. However, the precise path through which metabolic factors impact rosacea risk is still unclear. Therefore, this study aims to investigate the role of adiponectin, a crucial adipokine that regulates metabolic homeostasis, in the pathogenesis of rosacea.

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The presence of the blood group H2 antigen on the membrane of red blood cells determines blood type O in individuals and this H2 antigen serves as a precursor to the A and B antigens expressed in blood types A and B, respectively. However, the specific involvement of ABH antigens in skin diseases is unknown. Therefore, we aim to investigate the expression of ABH antigens in skin tissue of patients with atopic dermatitis (AD) and MC903-induced AD-like mice.

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The effects of ultraviolet (UV) radiation on brain function have previously been investigated; however, the specific neurotransmitter-mediated mechanisms responsible for UV radiation-induced neurobehavioral changes remain elusive. In this study, we aimed to explore the mechanisms underlying UV radiation-induced neurobehavioral changes. In a mouse model, we observed that UV irradiation of the skin induces deficits in hippocampal memory, synaptic plasticity, and adult neurogenesis, as well as increased dopamine levels in the skin, adrenal glands, and brain.

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UV irradiation of the human skin downregulates lipid synthesis and adipokine production in subcutaneous fat. Recent evidence has suggested that UV exposure limits body weight gain in mouse models of obesity. However, the relationship between norepinephrine and UV irradiation has not been previously reported.

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Mitochondria are essential organelles in cellular energy metabolism and other cellular functions. Mitochondrial dysfunction is closely linked to cellular damage and can potentially contribute to the aging process. The purpose of this study was to investigate the subcellular structure of mitochondria and their activities in various cellular environments using super-resolution stimulated emission depletion (STED) nanoscopy.

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Article Synopsis
  • Nummular eczema, a chronic skin condition marked by coin-shaped lesions, has unclear underlying mechanisms despite being recognized since 1857.
  • A study analyzing skin samples from affected and healthy individuals revealed that the desquamation process, which is essential for skin renewal, is impaired in nummular eczema due to disorganization and increased expression of certain skin proteins.
  • The research also indicated that higher levels of an inhibitor (Kazal-type-related inhibitor-1) in affected skin might prevent the normal breakdown of structures that facilitate skin shedding, contributing to delayed desquamation and symptom persistence.
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Heat shock protein 47 (HSP47), also known as , functions as a collagen-specific molecular chaperone protein essential for the formation and stabilization of the collagen triple helix. Here, we delved into the regulatory pathways governed by HSP47, shedding light on collagen homeostasis. Our investigation revealed a significant reduction in mRNA levels in the skin tissue of older mice as compared to their younger counterparts.

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Psoriasis is a multifaceted chronic inflammatory skin disease; however, its underlying molecular mechanisms remain unclear. In this study, we explored the role of fucosylation in psoriasis using an imiquimod-induced psoriasis-like mouse model. ABH antigen and fucosyltransferase 1 (Fut1) expression was reduced in the granular layer of lesional skin of patients with psoriasis.

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Brain ageing, the primary risk factor for cognitive impairment, occurs because of the accumulation of age-related neuropathologies. Identifying effective nutrients that increase cognitive function may help maintain brain health. Tomatoes and lemons have various bioactive functions and exert protective effects against oxidative stress, ageing and cancer.

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Skin photoaging induced by ultraviolet (UV) irradiation contributes to the formation of thick and coarse wrinkles. Humans are exposed to UV light throughout their lives. Therefore, it is crucial to determine the time-sequential effects of UV on the skin.

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Aging is accompanied by impaired mitochondrial function and accumulation of senescent cells. Mitochondrial dysfunction contributes to senescence by increasing the levels of reactive oxygen species and compromising energy metabolism. Senescent cells secrete a senescence-associated secretory phenotype (SASP) and stimulate chronic low-grade inflammation, ultimately inducing inflammaging.

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Leucine-rich alpha-2-glycoprotein 1 (LRG1) mediates skin repair and fibrosis by stimulating the transforming growth factor-beta (TGF-β) signaling pathway. In the present study, we investigated the effect of LRG1 on extracellular matrix (ECM) integrity in fibroblasts, as well as on skin aging. The treatment of dermal fibroblasts with purified recombinant human LRG1 increased type I collagen secretion and decreased matrix metalloproteinase-1 secretion.

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The matricellular secreted protein acidic and rich in cysteine (SPARC; also known as osteonectin), is involved in the regulation of extracellular matrix (ECM) synthesis, cell-ECM interactions, and bone mineralization. We found decreased SPARC expression in aged skin. Incubating foreskin fibroblasts with recombinant human SPARC led to increased type I collagen production and decreased matrix metalloproteinase-1 (MMP-1) secretion at the protein and mRNA levels.

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Purpose: Pseudognaphalium affine (P. affine), a medicinal plant, has long been used to treat various diseases due to its astringent and vulnerary effects. These therapeutic benefits are largely attributed to high contents of phytochemicals, such as flavonoids and polyphenols, that have anti-inflammatory and tissue-protective activities.

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We recently reported that exposure of skin to ultraviolet B (UVB) irradiation for 2 weeks induces stress and accelerates skin aging. Interestingly, aldosterone synthase is known to be crucial in generating UVB-induced stress-related responses, suggesting that drugs that regulate its activity can be used as skin antiaging agents. Through extensive drug screening, we have identified 20-hydroxyecdysone (20E), a steroidal prohormone secreted by the prothoracic glands of insects, as a potent inhibitor of UVB-induced aging.

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Abnormalities in the extracellular matrix (ECM) caused by ultraviolet (UV) radiation are mediated by epigenetic mechanisms. Enhancer of zeste homolog 2 (EZH2) is a histone methyltransferase that is implicated in inflammation, immune regulation, and senescence. However, its role in controlling UV-induced ECM alterations in the skin remains elusive.

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Keloids are skin tumours caused by aberrant growth of dermal fibroblasts. Cellular senescence contributes to aging and various pathological conditions, including cancer, atherosclerosis, and fibrotic diseases. However, the effects of cellular senescence and senolytic drugs on keloids remain largely unknown.

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