Conventional aryl hydrocarbon receptor (AhR) antagonists, which play a critical role in modulating tumor immune evasion, have shown limited clinical translation due to poor solubility, restricted systemic exposure, and dose-limiting toxicities. To overcome these limitations, we developed SB5794, a phosphate prodrug of the potent AhR antagonist SB2617, designed to improve aqueous solubility and pharmacokinetic properties. SB5794 exhibited markedly enhanced solubility and achieved more than six-fold higher systemic exposure in mice compared with SB2617, while fully retaining its in vitro AhR antagonistic activity. In syngeneic tumor models, SB5794 significantly inhibited tumor growth, and its combination with anti–PD-1 therapy further enhanced antitumor efficacy. However, repeated-dose studies revealed dose-dependent histopathological changes in the gastrointestinal tract, liver, and immune organs. Collectively, these findings demonstrate that SB5794 possesses improved drug-like properties and strong immunomodulatory activity, supporting its potential as a next-generation AhR-targeted immunotherapeutic candidate.

Drug resistance in cancer cells remains a major obstacle limiting the clinical efficacy of current anticancer therapies. The induction of ferroptosis, an iron-dependent, regulated form of cell death, may offer an alternative therapeutic strategy to overcome such resistance. The generation of reactive oxygen species (ROS) has been implicated in this process, and depending on the cellular context, ROS can be either detrimental or beneficial. Ferroptosis can be effectively triggered in drug-resistant cancer cells in which ROS levels are often highly elevated. Key signaling pathways, including receptor tyrosine kinase (RTK), mitogen-activated protein kinase (MAPK), and nuclear factor erythroid 2-related factor 2 (NRF2), are promising targets for modulating ROS homeostasis and sensitizing cancer cells to ferroptosis. In this review, we discuss the molecular mechanisms governing ferroptosis, the interplay between ROS and ferroptosis resistance, and emerging therapeutic approaches designed to enhance ferroptosis induction in drug-resistant cancer cells. Altogether, a combination of ferroptosis inducers and conventional treatments may improve the therapeutic efficacy and help overcome resistance mechanisms.

X-linked ichthyosis (XLI) is an inherited disorder of keratinization resulting from a deficiency of steroid sulfatase (STS), for which no effective therapy is currently available. E-cadherin, a key upstream regulator of keratinocyte differentiation, has been found to be markedly overexpressed in STS-deficient HaCaT cells, suggesting its potential as a therapeutic target in XLI. To investigate the functional role of E-cadherin and explore its therapeutic potential, we introduced mutations into the N-terminal region of Ecadherin and examined the resulting effects on keratinocyte differentiation. In addition, a microRNA (miR-6766) and a rationally designed gapmer antisense oligonucleotide (gASO) targeting the same E-cadherin mRNA sequence were employed to modulate E-cadherin expression in HaCaT cells. Mutations within the N-terminal region of E-cadherin significantly reduced keratin 1 expression, underscoring the critical role of this domain in regulating keratinocyte differentiation. Treatment with miR-6766 led todownregulation of both early and terminal differentiation markers. Building on this, the gASO modified with 2′-O-methoxyethyl andphosphorothioate linkages exhibited enhanced potency and stability, resulting in stronger suppression of E-cadherin and keratin 1 expression compared with miR-6766 (maintained 37.7% greater inhibition of E-cadherin at 96 h and 35.7% greater inhibition of keratin 1 at 96 h). Furthermore, gASO treatment induced a concentration-dependent reduction in early (keratin 1 and keratin 10) and terminal (transglutaminase 1, involucrin, and loricrin) differentiation markers. These findings demonstrate that an E-cadherin– targeting gASO effectively suppresses abnormal keratinocyte differentiation and may serve as a promising therapeutic strategy for X-linked ichthyosis.

Skeletal muscle atrophy is a major complication associated with aging, chronic disease, and chemotherapy. Doxorubicin (Dox), a widely used anticancer agent, accelerates muscle wasting; however, the underlying cellular mechanisms remain poorly understood. In this study, we examined the effects of Dox on myogenic differentiation, senescence, and lipid metabolism using C2C12 myoblasts. Dox exposure impaired myotube formation without causing overt cytotoxicity. Mechanistically, Dox disrupted myogenic differentiation by inhibiting protein kinase B/mammalian target of rapamycin (AKT/mTOR) signaling, thereby de-repressing forkhead box O1/3 (FOXO1/3) and upregulating the muscle-specific ubiquitin ligases muscle atrophy F-box (MAFbx) and muscle RING finger 1 (MuRF1), which promote proteolysis. Dox also decreased glycogen synthase kinase 3β (GSK3β) phosphorylation while paradoxically increasing total and phosphorylated β-catenin, indicating dysregulated Wnt/β-catenin signaling. These alterations were accompanied by a senescence-like phenotype, characterized by elevated senescence-associated β-galactosidase (SA-β-gal) activity, increased phosphorylated histone variant γH2AX, and activation of the p53–p21 axis. Notably, cellular senescence coincided with excessive lipid accumulation in myotubes. Dox reduced phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) while enhancing expression of key lipogenic regulators, thereby creating a metabolic environment favoring lipid storage. Collectively, these findings demonstrate that Dox not only suppresses myogenic differentiation but also induces premature senescence and metabolic reprogramming toward lipid accumulation. Targeting these pathways through AMPK activation, FOXO inhibition, or senolytic interventions may offer therapeutic strategies to preserve skeletal muscle integrity in patients undergoing chemotherapy.

Genetic variation in the leptin receptor (LEPR) gene has been implicated in metabolic regulation, while the gut microbiome and circulating metabolites are increasingly recognized as mediators of host metabolic phenotype. However, the systems-level interactions among LEPR genotypes, gut microbial composition, and serum metabolomic profiles remain poorly understood, particularly in healthy individuals. We conducted a cross-sectional study involving 37 healthy Korean adults. Three LEPR single nucleotide polymorphisms (rs1137101, rs1173100, rs790419) were genotyped. Untargeted metabolomics of fasting serum was performed using gas chromatography–time-of-flight mass spectrometry, and gut microbiome composition was profiled by 16S rRNA gene sequencing. Statistical analysis included principal component analysis, Mann–Whitney U tests, and Spearman correlations. Network analysis integrating microbiome, metabolomic, and clinical phenotype data was conducted using Cytoscape. A total of 54 serum metabolites were identified. LEPR genotypes, particularly rs1137101 and rs1173100, were associated with differences in metabolites such as pimelic acid, malonic acid, and 2,4-dihydroxybutyric acid. Firmicutes negatively correlated with saturated fatty acids and organic acids, whereas Actinobacteria positively correlated with cholesterol and amino acids. Network analysis revealed indole-3-acetate and cholesterol as central nodes linking microbial taxa with body mass index and leptin levels. However, no direct molecular pathways connecting leptin or its receptor were identified. LEPR genetic variation is associated with distinct serum metabolomic patterns and microbiome–host networks in healthy adults. Although no direct leptin signaling links were found, network-level associations suggest indirect genetic influences on metabolic states through microbiome–metabolome interactions.These findings advance understanding of personalized metabolic regulation and gene–microbiome interplay.

Age-related macular degeneration (AMD) is a leading cause of blindness in people over 65 years old. Anti-vascular endothelial growth factor (VEGF) therapy is the first-line treatment for neovascular AMD (nAMD); however, fibrosis remains an unmet medical need due to the lack of effective medications. This study evaluated eight natural products from Celastrus orbiculatus, which has been reported to have anti-inflammatory effects, for their effects on the fibrotic pathological process as well as choroidal neovascularization (CNV). We investigated the half-maximal inhibitory concentration (IC 50) values of these compounds on VEGF and alphasmooth muscle actin (α-SMA, a fibrosis marker) expression-induced by human acute monocytic cell (THP-1) conditioned media in retinal pigment epithelium cells (ARPE-19). Four compounds reduced both VEGF and α-SMA at 10 μM, with three—Celafolin A-1, COFH5645, and COFH543435—showing the highest potency. Intravitreal injections of the compound in a mouse model of CNV induced by laser photocoagulation confirmed its efficacy. Celafolin A-1 significantly reduced α-SMA and VEGF expression and decreased hyper-reflective lesions and CNV areas. Binding affinity measurements using biolayer interferometry identified an interaction between Celafolin A-1 and crystallin alpha B (Cryab), a protein involved in stress responses and fibrosis. Celafolin A-1 reduced the expression levels of Cryab as well as its phosphorylated form at Ser45, indicating that its mechanism involves the regulation of Cryab phosphorylation. Taken together, Celafolin A-1 exhibits dual inhibitory effects on VEGF and fibrosis, suggesting it as a candidate for the treatment of nAMD.

Replicative senescence in endothelial cells is characterized by an irreversible cell cycle arrest and impaired endothelial function, contributing to vascular aging and cardiovascular disease. Natural compounds are being actively studied for their potential to delay cellular senescence and protect vascular health. Among them, rice bran has demonstrated several vascular benefits that are mainly attributed to gamma-oryzanol (γ-Orz), a major bioactive component in rice bran. However, its role in regulating endothelial replicative senescence and the underlying molecular mechanisms remain unclear. This study aimed to explore the protective effects of rice bran extract (RBE) and γ-Orz on replicative senescence in porcine coronary artery endothelial cells (PCAECs). Replicative senescence was modeled in PCAECs by serial passaging from P1 to P3 with varying concentrations of RBE and γ-Orz.Senescence was evaluated by measuring senescence-associated β-galactosidase (SA-β-gal) activity, cell proliferation, oxidative stress, and the expression of cell cycle regulatory proteins. RBE and γ-Orz significantly reduced SA-β-gal activity, improved proliferation, and decreased oxidative stress in P3 cells, along with downregulation of senescence-related proteins p53, p21, and p16. Additionally, γ-Orz suppressed sodium-glucose co-transporter 2 expression, reduced NADPH oxidase overexpression, and restored eNOS levels. These findings indicate that RBE and γ-Orz delay endothelial senescence by alleviating oxidative stress, highlighting their potential to reduce cardiovascular disease risk associated with endothelial senescence.

Mutations in p53 have been implicated in poor prognosis and reduced sensitivity to 5-fluorouracil (5-FU) treatment in colon cancer.While p53-dependent mechanisms have been widely studies, less is known about how p53 deficiency reshapes cellular signaling and contributes to 5-FU resistance. In this study, we aimed to profile proteomic alterations associated with p53 loss by comparing colon cancer cells with and without p53 expression. Differentially expressed proteins (DEPs) related to cell cycle regulation were of particular interest, as 5-FU treatment induced G1 phase arrest in HCT116 p53 wild-type (WT) cells, whereas p53 knockout (KO) cells predominantly showed S phase arrest. We identified several DEPs in p53 deficient cells following 5-FU treatment. Notably, F3 expression was increased, while aldehyde dehydrogenase family 1 member A4 (ALDH1A3), histone deacetylase 2 (HDAC2), and protein S100-A4 (S100A4) were decreased. The expression levels of these genes were associated with overall survival in patients with colon cancer. These findings highlight proteomic alterations linked to p53 deficiency and support a proposed model in which differential regulation of specific proteins may be associated with reduced sensitivity to 5-FU, providing a basis for future mechanistic and functional studies.

Alzheimer’s disease (AD) is increasingly recognized as a disorder with significant vascular involvement, with microvascular damage and thromboinflammation often preceding classical amyloid pathology by several years. Elevated levels of prothrombin and thrombin, along with aberrant platelet activation, have been reported in individuals with AD. We hypothesized that platelet hyperactivity in AD results from an exaggerated response to thrombin in the presence of elevated amyloid beta 1-40 (Aβ₁₋₄₀), a peptide that accumulates during the early stages of AD. Platelet activation in response to Aβ₁₋₄₀ and thrombin was assessed using aggregation assays with an aggregometer, adhesion measurements by confocal microscopy, and spreading via both confocal microscopy and scanning electron microscopy. Reactive oxygen species (ROS) production and integrin α IIbβ 3 activation were quantified by flow cytometry. The roles of NADPH oxidase (NOX), ROS, and integrin signaling were examined using selective inhibitors. Aβ₁₋₄₀ significantly enhanced thrombin-induced platelet adhesion, aggregation, and spreading via NOX-derived ROS and integrin α IIbβ 3 activation. Aβ₁₋₄₀ also promoted platelet binding to fibrinogen and cerebrovascular endothelial cells, accompanied by distinct morphological changes. Inhibition of NOX or integrin α IIbβ 3 significantly reduced these effects. These findings identify a novel Aβ₁₋₄₀–NOX–ROS–integrin α IIbβ 3 axis that drives platelet hyperactivation and cerebrovascular interactions in AD.Targeting this pathway with antithrombotic or antioxidative strategies may offer therapeutic potential in mitigating AD-associated vascular pathology.

Sleep deprivation (SD) disrupts homeostatic regulation and increases vulnerability to stress and mood disorders. This study investigated the duration-dependent effects of SD and elucidated the distinct roles of adenosine A1 receptors (A1R) and A2A receptors (A2AR) in behavioral and molecular alterations induced by 24, 48, and 72 h of SD in mice. SD for 48 h and 72 h, but not 24 h, significantly increased immobility time in the tail suspension test (TST) and forced swim test (FST), accompanied by elevated plasma corticosterone (CORT) levels, indicating a duration-dependent stress response. Hippocampal A1R mRNA expression was significantly reduced, whereas A2AR mRNA expression was markedly increased at 48 h and 72 h of SD. Pharmacological blockade of either A1R (DPCPX) or A2AR (SCH 58261) significantly attenuated SD-induced depression-like behaviors and CORT elevation, whereas activation of A1R with the agonist CPA exacerbated depression-like behavior at 24 h and 48 h of SD. These findings suggest that A2AR upregulation may represent a pathological response to prolonged SD, whereas A1R downregulation may reflect compensatory adaptation to sustained receptor activation. Taken together, our results demonstrate that A1R and A2AR play distinct roles in SD-induced depression-like behaviors.