Age-related hearing loss (ARHL) is one of the most prevalent types of sensory decline in a superaging society. Although various studies have focused on the effect of oxidative stress on the inner ear as an inducer of ARHL, there are no effective preventive approaches for ARHL. Recent studies have suggested that oxidative stress-induced DNA damage responses (oxidative DDRs) drive cochlear cell senescence and contribute to accelerated ARHL, and autophagy could function as a defense mechanism against cellular senescence in auditory cells.
View Article and Find Full Text PDFThe active form of vitamin D, 1α,25-dihydroxyvitamin D [1,25(OH)D], is a principal regulator of calcium homeostasis through activation of the vitamin D receptor (VDR). Previous studies have shown that 2α-(3-hydroxypropyl)-1,25D (O1C3) and 2α-(3-hydroxypropoxy)-1,25D (O2C3), vitamin D derivatives resistant to inactivation enzymes, can activate VDR, induce leukemic cell differentiation, and increase blood calcium levels in rats more effectively than 1,25(OH)D. In this study, to further investigate the usefulness of 2α-substituted vitamin D derivatives, we examined the effects of O2C3, O1C3, and their derivatives on VDR activity in cells and mouse tissues and on osteoblast differentiation of dedifferentiated fat (DFAT) cells, a cell type with potential therapeutic application in regenerative medicine.
View Article and Find Full Text PDFThere is no straightforward method to visualize the intracellular distribution of nuclear receptors, such as retinoid X receptors (RXRs), which are trafficked between the cytosol and nucleus. Here, in order to develop a simple fluorescence labeling method for RXRs, we designed and synthesized compound , consisting of an RXR-selective antagonist, CBTF-EE (), linked via an ether bond to the fluorophore nitrobenzoxadiazole (NBD). Compound is nonfluorescent, but the ether bond (-O-NBD) reacts with biothiols such as cysteine and homocysteine to generate a thioether (-S-NBD), followed by intramolecular Smiles rearrangement with an amino group such as that of lysine to form a fluorescent secondary amine (-NH-NBD) adjacent to the binding site.
View Article and Find Full Text PDFTo clarify the mechanism underlying the development and poor prognosis of combined hepatocellular-cholangiocarcinoma (cHCC-CCA), we characterized liver cancer driver mutations and poor prognostic markers in both the HCC and intrahepatic CCA (iCCA) components of a cHCC-CCA tumor. The telomerase reverse transcriptase () promoter mutation C228T was quantified by digital polymerase chain reaction using DNA from multiple microdissected cancer components of a single cHCC-CCA nodule. The protein expression of cancer-related markers, including TERT, was examined by serial thin-section immunohistochemistry and double-staining immunofluorescence.
View Article and Find Full Text PDFThe active form of vitamin D, 1α,25-dihydroxyvitamin D [1,25(OH)D], is a major regulator of calcium homeostasis through activation of the vitamin D receptor (VDR). We have previously synthesized vitamin D derivatives with large adamantane (AD) rings at position 24, 25, or 26 of the side chain to study VDR agonist and/or antagonist properties. One of them-ADTK1, with an AD ring and 23,24-triple bond-shows a high VDR affinity and cell-selective VDR activity.
View Article and Find Full Text PDFBile acids are major components of bile; they emulsify dietary lipids for efficient digestion and absorption and act as signaling molecules that activate nuclear and membrane receptors. The vitamin D receptor (VDR) is a receptor for the active form of vitamin D and lithocholic acid (LCA), a secondary bile acid produced by the intestinal microflora. Unlike other bile acids that enter the enterohepatic circulation, LCA is poorly absorbed in the intestine.
View Article and Find Full Text PDFBackground And Objectives: The potential role of the transcription factor Differentiated embryo-chondrocyte 2 (Dec2) in the progression of inflammatory diseases such as periodontitis has been unclear. Here, the effect of Dec2 on the expression of RANKL and on osteoclastogenesis was determined.
Material And Methods: Wild-type (WT) and Dec2 knockout (KO) mice as a model for periodontitis were used to assess alveolar bone resorption by microcomputed tomography (CT).
Ess2, also known as Dgcr14, is a transcriptional co-regulator of CD4 T cells. Ess2 is located in a chromosomal region, the loss of which has been associated with 22q11.2 deletion syndrome (22q11DS), which causes heart defects, skeletal abnormalities, and immunodeficiency.
View Article and Find Full Text PDFBackground: Gastrointestinal bleeding is one of the major gastrointestinal diseases. In this study, our objective was to compare Glasgow-Blatchford score (GBS), AIMS65 score, MAP score, Modified GBS, and Iino score as outcome measures for upper gastrointestinal bleeding. In addition, we extracted factors associated with hemostatic procedures including endoscopy, and proposed a new robust score model.
View Article and Find Full Text PDFBile acids (BAs) are a group of amphiphilic molecules consisting of a rigid steroid core attached to a hydroxyl group with a varying number, position, and orientation, and a hydrophilic side chain. While BAs act as detergents to solubilize lipophilic nutrients in the small intestine during digestion and absorption, they also act as hormones. Farnesoid X receptor (FXR) is a nuclear receptor that forms a heterodimer with retinoid X receptor α (RXRα), is activated by BAs in the enterohepatic circulation reabsorbed via transporters in the ileum and the colon, and plays a critical role in regulating gene expression involved in cholesterol, BA, and lipid metabolism in the liver.
View Article and Find Full Text PDFBackground: Cholesterol loaded macrophage foam cells are a prominent feature of atherosclerotic plaques. Single-cell RNA sequencing has identified foam cells as TREM2 (triggering receptor expressed on myeloid cells 2) positive populations with low expression of inflammatory genes, resembling the TREM2 positive microglia of neurodegenerative diseases. Cholesterol loading of macrophages in vitro results in activation of LXR (liver X receptor) transcription factors and suppression of inflammatory genes.
View Article and Find Full Text PDFSodium fluoride (NaF) is widely used in clinical dentistry. However, the administration of high or low concentrations of NaF has various functions in different tissues. Understanding the mechanisms of the different effects of NaF will help to optimize its use in clinical applications.
View Article and Find Full Text PDF1α,25-Dihydroxyvitamin D [1α,25(OH)D, ] is an active form of vitamin D and regulates various biological phenomena, including calcium and phosphate homeostasis, bone metabolism, and immune response via binding to and activation of vitamin D receptor (VDR). Lithocholic acid (LCA, ) was identified as a second endogenous agonist of VDR, though its potency is very low. However, the lithocholic acid derivative () is a more potent agonist than 1α,25(OH)D, (), and its carboxyl group has similar interactions to the 1,3-dihydroxyl groups of with amino acid residues in the VDR ligand-binding pocket.
View Article and Find Full Text PDFBenzo[a]pyrene (BaP) is an environmental pollutant produced by combustion processes and is present in grilled foods as well as in tobacco smoke. BaP acts as an agonist for the aryl hydrocarbon receptor (AHR), and is metabolized by AHR-inducing enzymes. BaP metabolism can result in either detoxification or metabolic activation, the latter leads to an increased risk of disease, particularly lung cancer and cardiovascular disease, in a context-dependent manner.
View Article and Find Full Text PDFCheckpoint kinase 1 (CHK1) plays a key role in genome surveillance and integrity throughout the cell cycle. Selective inhibitors of CHK1 (CHK1i) are undergoing clinical evaluation for various human malignancies, including neuroblastoma. In this study, one CHK1i-sensitive neuroblastoma cell line, CHP134, was investigated, which characteristically carries MYCN amplification and a chromosome deletion within the 10q region.
View Article and Find Full Text PDFThe nuclear receptors liver X receptor α (LXRα) and LXRβ are lipid sensors that regulate lipid metabolism and immunity. Natural killer T (NKT) cells, a T cell subset expressing surface markers of both natural killer cells and T lymphocytes and involved in antitumor immunity, are another abundant immune cell type in the liver. The potential function of the metabolic regulators LXRα/β in hepatic NKT cells remains unknown.
View Article and Find Full Text PDFBackground: Zinc is a mineral that is essential for biological molecules, such as transcription factors, and is involved in the maintenance of intestinal homeostasis. Vitamin D signaling is mediated by vitamin D receptor (VDR) activated by 1α,25-dihydroxyvitamin D [1,25(OH)D] and is also important in intestinal functions, such as calcium absorption and epithelial barrier maintenance. However, the crosstalk between vitamin D signaling and zinc signaling in intestinal cells remains poorly understood.
View Article and Find Full Text PDFPeriodontal inflammation is a common inflammatory disease associated with chronic inflammation that can ultimately lead to alveolar attachment loss and bone destruction. Understanding autophagy and pyroptosis has suggested their significant roles in inflammation. In recent years, studies of differentiated embryo-chondrocyte expressed genes 1 and 2 (Dec1 and Dec2) have shown that they play important functions in autophagy and in pyroptosis, which contribute to the onset of periodontal inflammation.
View Article and Find Full Text PDFKlotho is one of the known anti-aging genes, and functions as an inhibitor of the insulin-like growth factor 1(IGF-1) pathway. However, the clinical significance of Klotho expression in cancer tissues have not been elucidated yet. In this study, we aimed to investigate the clinical significance of Klotho expression in breast cancer patients.
View Article and Find Full Text PDFDecreasing the partition coefficient (LogP) by the introduction of a hydrophilic group is the conventional approach for improving the aqueous solubility of drug candidates, but is not always effective. Since melting point is related to aqueous solubility, we and other groups have developed alternative strategies to improve solubility by means of chemical modification to weaken intermolecular interaction in the solid state, thereby lowering the melting point and increasing the solubility. Here, we show that converting the symmetrical molecular structure of the clinically used estrogen receptor (ER) antagonist cyclofenil (1) into asymmetrical form by introducing an alkyl group enhances the aqueous solubility.
View Article and Find Full Text PDFBackground And Objectives: Periodontal pathogens initiate various diseases and induce inflammatory host responses. The activation of inflammasomes triggers caspase-1 and interleukin (IL)-1β-mediated pyroptosis via gasdermin D (GSDMD). Differentiated embryo chondrocyte 2 (Dec2) is a transcription repressor that controls the expression of genes involved in innate immune and inflammatory responses.
View Article and Find Full Text PDFPeriodontal ligament fibroblasts (PDLFs) are integral to the homeostasis of periodontal tissue. The transcription factor Dec1 functions to modulate Porphyromonas gingivalis-induced periodontal inflammation. Here, we aimed to characterize the Dec1-mediated autophagy in PDLFs under inflammatory conditions.
View Article and Find Full Text PDF