Publications by authors named "Hyojong Lee"

Background: Diabetic retinopathy (DR), a major blindness cause in developed countries, is intricately linked to diabetes management and its duration. Here, we demonstrate that HDAC6 mediates NLRP3 inflammasome activation under diabetic conditions, leading to retinal inflammation and degeneration.

Methods: This study demonstrated the therapeutic effects of HDAC6 genetic ablation, pharmacological inhibition, and HDAC6-deficient bone marrow transplantation in a diabetes model induced by streptozotocin and a high-fat diet.

View Article and Find Full Text PDF

The human gut microbiota significantly influences various physiological systems, including immune, nervous, and metabolic systems. Recent studies suggest that gut microbiota may affect sleep quality with certain bacteria and metabolites being linked to sleep patterns. However, the underlying chemical signaling pathway remains unclear.

View Article and Find Full Text PDF

The behavior of gases within subsurface pores determines the oil and gas recovery and CO storage in the region. In this study, we report a novel method based on Raman spectroscopy for observing the distributions of CH and CO gases in the pores of sandstone reservoirs. First, we designed a pressure-cell to inject gases into a sample.

View Article and Find Full Text PDF

Monocrystalline chalcogenide thin films in freestanding forms are very much needed in advanced electronics such as flexible phase change memories (PCMs). However, they are difficult to manufacture in a scalable manner due to their growth and delamination challenges. Herein, we report a viable strategy for a wafer-scale epitaxial growth of monocrystalline germanium telluride (GeTe) membranes and their deterministic integrations onto flexible substrates.

View Article and Find Full Text PDF

and are fish gut bacteria that have been isolated from the guts of and , respectively. A total of 22 compounds (-) were isolated from these two bacteria; 16 compounds (-) from and 6 compounds (-) from . Their chemical structures were elucidated by spectroscopic and spectrometric data analysis and chemical synthesis.

View Article and Find Full Text PDF
Article Synopsis
  • A family of pyrazinone metabolites were studied from the ATCC 29971 strain, featuring six compounds that are hydroxylated or methoxylated.
  • These metabolites are hypothesized to form through a unique noncatalytic oxa-Michael addition involving water or methanol, with isopropyl alcohol also serving as a donor in the reaction.
  • Notably, both the metabolites and their synthetic precursor demonstrated significant inhibition of breast cancer cell migration.
View Article and Find Full Text PDF

Photorhabdus luminescens is a gram-negative bioluminescent bacterium known as an intestinal bacterium that coexists in the digestive tract of insect-pathogenic nematodes. As part of our ongoing exploration to identify bioactive compounds from diverse natural resources, the chemical analysis of the cultures of P. luminescens KACC 12254 via LC/MS and TLC-based analyses enabled the isolation and identification of a major fluorescent compound.

View Article and Find Full Text PDF
Article Synopsis
  • - Chronic obstructive pulmonary disease (COPD) arises from unresolved inflammation due to toxic environmental factors, with particulate matter (PM) being a major risk factor, but the mechanism was previously unclear.
  • - In experiments using a mouse model, repeated exposure to PM led to chronic inflammation driven by macrophages and decreased levels of certain enzymes involved in NAD synthesis, caused by changes in how genes are regulated.
  • - Resveratrol, a natural compound that activates SIRT1, was shown to reduce PM-induced inflammation and COPD progression, suggesting that targeting metabolic and epigenetic shifts in macrophages may offer new treatments for COPD.
View Article and Find Full Text PDF

Single allelic mutations in the gene encoding the forebrain-specific transcription factor FOXG1 lead to FOXG1 syndrome (FS). Patient-specific animal models are needed to understand the etiology of FS, as FS patients show a wide spectrum of symptoms correlated with location and mutation type in the FOXG1 gene. Here we report the first patient-specific FS mouse model, Q84Pfs heterozygous (Q84Pfs-Het) mice, mimicking one of the most predominant single nucleotide variants in FS.

View Article and Find Full Text PDF

Panax ginseng, also known as Korean ginseng, is a traditional remedy widely used in Asian countries. Its major active compounds are ginsenosides, specifically triterpenoid saponins. Among them, one notable ginsenoside called Re has shown various biological effects, including anti-cancer and anti-inflammatory properties.

View Article and Find Full Text PDF

The renin-angiotensin (RA) system has been implicated in lung tumorigenesis without detailed mechanistic elucidation. Here, we demonstrate that exposure to the representative tobacco-specific carcinogen nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) promotes lung tumorigenesis through deregulation of the pulmonary RA system. Mechanistically, NNK binding to the nicotinic acetylcholine receptor (nAChR) induces Src-mediated signal transducer and activator of transcription 3 (STAT3) activation, resulting in transcriptional upregulation of angiotensinogen (AGT) and subsequent induction of the angiotensin II (AngII) receptor type 1 (AGTR1) signaling pathway.

View Article and Find Full Text PDF

Antibiotic resistance is one of the world's most urgent public health problems, and novel antibiotics to kill drug-resistant bacteria are needed. Natural product-derived small molecules have been the major source of new antibiotics. Here we describe a family of antibacterial metabolites isolated from a probiotic bacterium, .

View Article and Find Full Text PDF

Background: Cancer stem-like cells (CSCs) play a pivotal role in lung tumor formation and progression. Nerve injury-induced protein 1 (Ninjurin1, Ninj1) has been implicated in lung cancer; however, the pathological role of Ninj1 in the context of lung tumorigenesis remains largely unknown.

Methods: The role of Ninj1 in the survival of non-small cell lung cancer (NSCLC) CSCs within microenvironments exhibiting hazardous conditions was assessed by utilizing patient tissues and transgenic mouse models where Ninj1 repression and oncogenic Kras or carcinogen-induced genetic changes were induced in putative pulmonary stem cells (SCs).

View Article and Find Full Text PDF

Ninjurin1 (Ninj1), an adhesion molecule, regulates macrophage function in hyaloid regression, multiple sclerosis, and atherosclerosis. However, its biological relevance and the mechanism underlying its function in vascular network integrity have not been studied. In this study, we investigated the role of Ninj1 in physiological (postnatal vessel formation) and pathological (endotoxin-mediated inflammation and diabetes) conditions and developed a strategy to regulate Ninj1 using specific micro (mi)RNAs under pathological conditions.

View Article and Find Full Text PDF

Cristacarpin is a novel prenylated pterocarpan that reportedly exhibits broad anti-cancer activity by enhancing endoplasmic reticulum stress. However, whether and how cristacarpin affects in-flammatory processes remain largely unknown. In the present study, the anti-inflammatory effect of cristacarpin on lipopolysaccharide (LPS)-induced inflammation was investigated using zebrafish embryos, RAW 264.

View Article and Find Full Text PDF

Mammalian claudin-5 (cldn5), a zebrafish cldn5a homolog, is essential to blood-brain barrier (BBB) integrity. Previously, the existence of an endothelial tight junction-based BBB with cldn5a expression in the cerebral microvessels was reported in zebrafish. However, the role of cldn5a in the cerebral microvessels of developing zebrafish has not been elucidated.

View Article and Find Full Text PDF

Background: Artemisia capillaris is among the most abundantly used traditional medicines, utilized in East Asia to treat diverse illnesses, including gastrointestinal tract diseases. We previously reported that an aqueous extract of A. capillaris (AEAC) inhibited gastric inflammation induced by HCl/ethanol via reactive oxygen species scavenging and NF-κB downregulation.

View Article and Find Full Text PDF
Article Synopsis
  • - The study explores the protective effects of α-humulene, a compound found in many fragrant plants, on gastric injuries caused by hydrochloric acid (HCl) and ethanol in both rat models and human mast cells (HMC-1).
  • - Findings show that α-humulene reduces gastric lesions and acid secretion while decreasing harmful substances like reactive oxygen species and malondialdehyde, likely by enhancing certain protective compounds in the body.
  • - The results suggest that α-humulene not only lowers histamine levels and reduces inflammation by inhibiting a specific signaling pathway but also promotes protective factors in the stomach, indicating its potential as a treatment for gastritis linked to stress or alcohol.
View Article and Find Full Text PDF
Article Synopsis
  • *Melatonin has anti-angiogenic properties but its effectiveness is limited due to poor absorption and short duration in the body.
  • *A new compound, NB-5-MT, was developed to better target HIF-1α, showing significant anti-cancer effects by reducing tumor growth and angiogenesis, making it a promising candidate for cancer therapy.
View Article and Find Full Text PDF

Kushen (Radix ) is used to treat ulcerative colitis, tumors, and pruritus. Recently, phaseolin, formononetin, matrine, luteolin, and quercetin, through a network pharmacology approach, were tentatively identified as five bioactive constituents responsible for the anti-inflammatory effects of . However, the role of phaseolin (one of the primary components of ) in the direct regulation of inflammation and inflammatory processes is not well known.

View Article and Find Full Text PDF
Article Synopsis
  • Scientists found that slow-cycling cancer cells (SCCs) can make cancer come back and resist treatment, but it's hard to study them.
  • They discovered a specific group of SCCs in lung cancer that survive tough conditions by using a special gene called RGS2.
  • By blocking RGS2 or using certain medications like Viagra, they can make these cells die, suggesting a new way to help lung cancer patients after chemotherapy.
View Article and Find Full Text PDF

Background: Under hypoxia, mouse embryonic stem cells (mESCs) lose the ability to self-renew and begin to differentiate through down-regulation of LIFR-STAT3 pathway via hypoxia-inducible factor-1α (HIF-1α). However, it remains largely unknown what kinds of factors are involved in hypoxia-induced differentiation of mESCs.

Purpose: This study aims to identify the differentially expressed genes (DEGs) in early differentiation of mESCs under hypoxia.

View Article and Find Full Text PDF

Slow-cycling cancer cells (SCCs) with a quiescence-like phenotype are believed to perpetrate cancer relapse and progression. However, the mechanisms that mediate SCC-derived tumor recurrence are poorly understood. Here, we investigated the mechanisms underlying cancer recurrence after chemotherapy, focusing on the interplay between SCCs and the tumor microenvironment.

View Article and Find Full Text PDF

Quiescent cancer cells are believed to cause cancer progression after chemotherapy through unknown mechanisms. We show here that human non-small cell lung cancer (NSCLC) cell line-derived, quiescent-like, slow-cycling cancer cells (SCC) and residual patient-derived xenograft (PDX) tumors after chemotherapy experience activating transcription factor 6 (ATF6)-mediated upregulation of various cytokines, which acts in a paracrine manner to recruit fibroblasts. Cancer-associated fibroblasts (CAF) underwent transcriptional upregulation of COX2 and type I collagen (Col-I), which subsequently triggered a slow-to-active cycling switch in SCC through prostaglandin E (PGE)- and integrin/Src-mediated signaling pathways, leading to cancer progression.

View Article and Find Full Text PDF