Publications by authors named "Jihye Kwak"

Human papillomavirus (HPV) infection has emerged as an etiologic factor of squamous papilloma (SP). The oropharynx and larynx are common sites of SP, but studies on the prevalence of HPV infection in these sites are lacking. This study aimed to evaluate and compare the prevalence and characteristics of HPV infection in oropharyngeal SP (OPSP) and laryngeal SP (LSP).

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Mesenchymal stem cells (MSCs) have garnered attention for their regenerative and immunomodulatory capabilities in clinical trials for various diseases. However, the effectiveness of MSC-based therapies, especially for conditions like graft-versus-host disease (GvHD), remains uncertain. The cytokine interferon (IFN)-γ has been known to enhance the immunosuppressive properties of MSCs through cell-to-cell interactions and soluble factors.

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Studies on human papillomavirus (HPV) infection in oropharyngeal squamous papilloma (OPSP) are lacking, although HPV infection has been recognized as the primary cause of oropharyngeal cancer for several decades. This study aimed to evaluate the prevalence and characteristics of HPV infections in patients with OPSP. We retrospectively enrolled patients with histologically confirmed OPSP in whom the presence of HPV infections and p16 expression were evaluated.

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Mesenchymal stem cells (MSCs) are one of the most extensively studied stem cell types owing to their capacity for differentiation into multiple lineages as well as their ability to secrete regenerative factors and modulate immune functions. However, issues remain regarding their further application for cell therapy. Here, to demonstrate the superiority of the improvement of MSCs, we divided umbilical cord blood-derived MSCs (UCB-MSCs) from 15 donors into two groups based on efficacy and revealed donor-dependent variations in the anti-inflammatory effect of MSCs on macrophages as well as their immunoregulatory effect on T cells.

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Background: Posterior reversible encephalopathy syndrome (PRES) manifests many neurological symptoms with typical features on neuroimaging studies and has various risk factors. Cyclophosphamide is one of the therapeutic agents for anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis. Cyclophosphamide as the sole cause of PRES has been reported in only a few cases.

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Article Synopsis
  • The study highlights the unique challenges in treating autism spectrum disorders (ASD) due to their diverse causes and emphasizes the need for individualized research approaches.
  • Using human-induced pluripotent stem cell (iPSC) technology, researchers created neuron-like cells from an ASD patient with a mutation in the DSCAM gene, finding significant reductions in DSCAM levels and associated synaptic function genes.
  • The findings indicate that the DSCAM mutation may lead to ASD symptoms by impairing NMDA receptor function, confirmed by observations in both iN cells and a mouse model with similar genetic alterations.
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Autophagy is a lysosomal degradation pathway that regulates cellular homeostasis. It is constitutively active in neurons and controls the essential steps of neuronal development, leading to its dysfunction in neurodevelopmental disorders. Although mTOR-associated impaired autophagy has previously been reported in neurodevelopmental disorders, there is lack of information about the dysregulation of mTOR-independent autophagy in neurodevelopmental disorders.

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CCCTC-binding factor (CTCF), a zinc finger protein, is a transcription factor and regulator of chromatin structure. Forebrain excitatory neuron-specific CTCF deficiency contributes to inflammation via enhanced transcription of inflammation-related genes in the cortex and hippocampus. However, little is known about the long-term effect of CTCF deficiency on postnatal neurons, astrocytes, or microglia in the hippocampus of adult mice.

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Umbilical cord blood (UCB) is used as a source of donor cells for hematopoietic stem cell (HSC) transplantation. The success of transplantation is dependent on the quality of cord blood (CB) units for maximizing the chance of engraftment. Improved outcomes following transplantation are associated with certain factors of cryopreserved CB units: total volume and total nucleated cell (TNC) count, mononuclear cell (MNC) count, and CD34+ cell count.

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Successfully navigating dynamic environments requires balancing the decision to stay at an optimal choice with that to switch to an alternative to acquire new knowledge. However, the genetic factors and cellular activity shaping this "stay or switch" action decision remains largely unidentified. Here we find that mice carrying a deletion of the exchange protein directly activated by cAMP 2 (Epac2) gene, a putative autism locus, exhibit perseverative "stay" behavior in a dynamic foraging task.

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CCCTC-binding factor (CTCF) is a genome organizer that regulates gene expression through transcription and chromatin structure regulation. CTCF also plays an important role during the developmental and adult stages. Cell-specific CTCF deletion studies have shown that a reduction in CTCF expression leads to the development of distinct clinical features and cognitive disorders.

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Cohen syndrome (CS), a rare autosomal recessive disorder, has been associated with genetic mutations in the gene, which regulates vesicle-mediated protein sorting and transport. However, the cellular mechanism underlying CS pathogenesis in patient-derived human neurons remains unknown. We identified a novel compound heterozygous mutation, due to homozygous variation of biparental origin and heterozygous variation inherited from the father, in the gene in a 20-month-old female patient.

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Conventional therapeutic applications of mesenchymal stromal cells (MSCs) focus on cell replacement and differentiation; however, increasing evidence suggests that most of their therapeutic effects are carried out by their various secretions. This study investigated the application of conditioned medium (CM) from human umbilical cord blood-derived MSCs (hUCB-MSCs) to improve hair growth and developed a method to reliably produce this optimized CM. Primed MSC-derived CM (P-CM) with combinations of TGF-β1 and LiCl was optimized by comparing its effects on the cell viability of dermal papilla cells (DPCs).

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Acute kidney injury (AKI) is the most common condition in hospitalized patients. As ischemia/reperfusion-induced AKI (IR-AKI) is as a major contributor to end-stage disease, an effective therapeutic intervention for IR-AKI is imperative. Erythropoietin (EPO) is a potent stimulator of erythroid progenitor cells and is significantly upregulated during hypoxia.

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Significant clinical symptoms of Cohen syndrome (CS), a rare autosomal recessive disorder, include intellectual disability, facial dysmorphism, postnatal microcephaly, retinal dystrophy, and intermittent neutropenia. CS has been associated with mutations in the VPS13B (vacuolar protein sorting 13 homolog B) gene, which regulates vesicle-mediated protein sorting and transport; however, the cellular mechanism underlying CS pathogenesis in patient-derived neurons remains uncertain. This report states that autophagic vacuoles accumulate in CS fibroblasts and the axonal terminals of CS patient-specific induced pluripotent stem cells (CS iPSC)-derived neurons; additionally, autophagic flux was significantly increased in CS-derived neurons compared to control neurons.

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Human mesenchymal stem cells (hMSCs), including human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs), which have high proliferation capacity and immunomodulatory properties, are considered to be a good candidate for cell-based therapies. hMSCs show enhanced therapeutic effects via paracrine secretion or cell-to-cell contact that modulates inflammatory or immune reactions. Here, treatment with cobalt chloride (CoCl) was more effective than naïve hUCB-MSCs in suppressing inflammatory responses in a coculture system with phytohemagglutinin- (PHA-) activated human peripheral blood mononuclear cells (hPBMCs).

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Breast cancer stem cells (BCSCs) have been shown to contribute to tumor growth, metastasis, and recurrence. They are also markedly resistant to conventional cancer treatments, such as chemotherapy and radiation. Recent studies have suggested that hypoxia is one of the prominent micro-environmental factors that increase the self-renewal ability of BCSCs, partially by enhancing CSC phenotypes.

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Background: Guanine nucleotide exchange factors (GEFs) activate small GTPases that are involved in several cellular functions. cAMP-guanine nucleotide exchange factor II (cAMP-GEF II) acts as a target for cAMP independently of protein kinase A (PKA) and functions as a GEF for Rap1 and Rap2. Although cAMP-GEF II is expressed abundantly in several brain areas including the cortex, striatum, and hippocampus, its specific function and possible role in hippocampal synaptic plasticity and cognitive processes remain elusive.

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Article Synopsis
  • * Wnt/β-catenin signaling is crucial for maintaining the self-renewal and differentiation abilities of MSCs, and it appears to play a role in the aging process of these cells, as its expression decreases with prolonged subculture.
  • * Activating Wnt signaling through specific treatments can delay cellular senescence in MSCs, while inhibiting Wnt can promote it; therefore, manipulating this signaling pathway may offer new strategies for enhancing the longevity and
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Among the members of the fibroblast growth factor (FGF) family that affect the growth, differentiation, migration, and survival of many cell types, FGF2 is the most abundant in the central nervous system. Because of its wound healing effects, FGF2 has potential as a therapeutic agent. The protein is also added to the culture media to maintain stem cells.

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WNT inhibitory factor-1 (WIF1) is an antagonist of the WNT signaling pathway. We investigated the relationship between WIF1 promoter methylation and regulation of the WNT/β-catenin signaling pathway, tumor grade, and survival in patients with astrocytoma. This study included 86 cases of astrocytoma, comprising 20 diffuse astrocytomas and 66 glioblastomas.

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