Tendinopathy is a complex disorder involving inflammation, oxidative stress, extracellular matrix damage, and changes in cellular metabolism. Cuproptosis is a type of regulated cell death that depends on copper and is associated with mitochondrial protein lipoylation and proteotoxic stress. This study investigated whether IL-1β-induced dysfunction of tendon progenitor cells (TPCs) is accompanied by changes in cuproptosis-associated genes and whether pharmacological modulation of copper availability alters this phenotype. Rat TPCs were stimulated with IL-1β, exposed to copper chloride (CuCl2) and the copper ionophore elesclomol (ES), and cotreated with the copper chelator tetrathiomolybdate (TTM). Cellular metabolic activity, gene expression, and reactive oxygen species (ROS) production were assessed. Bulk RNA-sequencing data from IL-1β-treated rat TPCs (GSE253913) and single-cell RNA-sequencing data from cultured human tendon-derived progenitor cells (GSE150482) were analyzed. In rats, transcriptomic analysis showed mainly an inflammatory response to IL-1β, with only slight changes in genes associated with copper and mitochondrial functions. IL-1β decreased TPC metabolic activity and the expression of tenogenic markers such as Scx, Col1a1, and Col3a1, while it increased inflammatory and catabolic markers, ROS production, and the expression of Dld and Lipt1. TTM attenuated these effects, restoring metabolic activity and some tenogenic markers, and reducing ROS, Dld, and Lipt1 levels. Exposure to ES + Cu triggered a TTM-sensitive phenotype characterized by reduced metabolic activity, decreased expression of tenogenic genes, increased ROS levels, and altered expression of cuproptosis-related genes. The human single-cell dataset analysis also revealed condition-dependent changes in mitochondrial lipoylation genes, including DLAT and DLST. Overall, these findings suggest that inflammatory TPC dysfunction is linked to copper-sensitive mitochondrial stress and gene changes related to cuproptosis pathways.
Background: With its steadily rising global prevalence posing a profound public health challenge, obesity represents a complex disorder sustained by reciprocal disturbances in energy partitioning, glycemic control, adipokine–neuroendocrine signaling, cellular redox equilibrium, and organ integrity. The aim of this study was to evaluate the dose-dependent therapeutic effects of Garcinia mangostana pericarp extract (GME) in a high-fat-diet (HFD)-induced obesity model, focusing on adipokine patterns, redox balance, organ injury, and hepatic Nrf2/HO-1 levels. Methods: Sixty-four male Wistar albino rats were allocated into a 16-week 2 × 4 factorial design (n = 8/group): standard basal diet or 60%-kcal fat HFD, each concurrently administered vehicle or GME via daily oral gavage at 100, 200, or 300 mg/kg. Somatic growth parameters and fasting glycometabolic indices (glucose, insulin, HOMA-IR) were quantified. Circulating lipids, hepatorenal injury enzymes, regulatory peptides (spexin, asprosin, adiponectin, BDNF, irisin, GLP-1), and systemic/tissue redox markers (TAS, TOS, OSI, MDA, 4-HNE, 8-OHdG, enzymatic antioxidants) were determined via automated clinical chemistry analyzers, spectrophotometry, and specific ELISA kits. Hepatorenal histopathology, epididymal adipocyte morphometry, and hepatic nuclear Nrf2 and HO-1 abundance were quantitatively analyzed. Statistical evaluations were conducted using two-way factorial ANOVA assessing diet, treatment, and diet-by-treatment interactions, followed by Tukey’s post hoc test for multiplicity-adjusted comparisons (p < 0.05). Results: HFD feeding significantly increased final body weight, energy intake, fasting glucose, and marked insulin resistance (HOMA-IR: 7.89 vs. 1.69; p < 0.001), precipitating atherogenic dyslipidemia and hepatorenal injury relative to controls. This pathophysiology coincided with elevated circulating asprosin, alongside marked depletion of spexin, adiponectin, BDNF, enzymatic antioxidant defenses (SOD, CAT, GPx; all p < 0.001), and Nrf2/HO-1 levels. GME produced dose-dependent improvements across these metabolic disturbances (diet × treatment interaction: p < 0.001 for all primary outcomes). Relative to HFD controls, the 300 mg/kg dose reduced final body weight by 15.3% (p < 0.05), HOMA-IR by 69.5% (p < 0.001), triglycerides by 47.6% (p < 0.001), serum MDA by 55.4% (p < 0.001), and adipocyte diameter by 49.1% (p < 0.001), providing the most prominent improvements in hepatic steatosis, renal injury scores, and upregulation of nuclear Nrf2 (3.81-fold) and liver HO-1 (4.74-fold). Conversely, the 200 mg/kg dose was distinguished by maximizing neurotrophic support (peak BDNF elevation, +84.8% vs. HFD controls; p < 0.05) and effectively restoring circulating metabolic peptides (spexin and adiponectin) toward physiological levels. Conclusions: These findings indicate that GME supplementation dose-dependently attenuates high-fat-diet-induced metabolic dysfunction, a response accompanied in part by a concomitant reduction in daily energy intake. Among the evaluated regimens, the 300 mg/kg dose exhibited the most potent efficacy in improving glycemic control (HOMA-IR), circulating lipid profiles (triglycerides, total cholesterol, LDL-C), and parenchymal organ injury (hepatic steatosis and renal vacuolation). In contrast, the 200 mg/kg dose was distinguished by optimizing neurotrophic support and restoring suppressed adipokines toward physiological concentrations. Consequently, GME is anticipated and considered to provide valuable support to medical nutrition therapy and clinical dietetic management as a promising functional nutraceutical for counteracting diet-induced metabolic abnormalities; prospective clinical trials remain necessary to establish safety, bioavailability, and therapeutic dosing.
Houttuynia cordata is commonly consumed as an herb and traditional medicinal ingredient in Asian regions. Although fermented products of H. cordata are gaining popularity as natural health products, their effects in experimental models of colitis remain unclear. This study investigated the protective effects of fermented H. cordata extract (FHE) and fermented H. cordata juice (FHJ) in dextran sulfate sodium (DSS)-induced colitis mice. The bioactive compounds in FHE and FHJ were analyzed via HPLC, confirmed via MS, and compared with those in non-fermented H. cordata extract. The fermented products contained higher levels of gallic acid, quercetin, isoquercitrin, and organic acids, including lactic, glucuronic, butyric, and acetic acids, whereas their caffeic acid, rutin, total phenolic, and total flavonoid contents were lower. In an animal study, male C57BL/6 mice were administered 500 or 1000 mg/kg of FHE and 200 or 400 mg/kg of FHJ as low and high doses for 23 days, with 2.5% DSS in the drinking water on days 15–21 followed by drinking water without DSS on days 22–23. Pretreatment with FHE and FHJ ameliorated the severity of the induced colitis, as indicated by reduced weight loss, decreased disease activity index, restored colon length (8.82 ± 0.29 cm with FHJ 400 mg/kg versus 7.53 ± 0.08 cm in the DSS group, p < 0.001), and protection against histopathological injury, most evidently with the FHE 500 mg/kg and FHJ 400 mg/kg treatments. Intestinal barrier integrity was maintained as shown by decreased permeability to FITC-dextran (570 ± 56 ng/mL with FHJ 400 mg/kg versus 1963 ± 183 ng/mL with DSS group, p < 0.001), elevated levels of colonic Muc2 mRNA (with FHJ at both doses), and upregulation of the tight junction proteins ZO-1 (with FHE at 1000 mg/kg) and claudin-1 (with FHE at both doses and FHJ at 400 mg/kg). Moreover, pretreatment with both FHE and FHJ diminished colonic mRNA expression of TNF-α and IL-1β, whereas IL-6 was reduced under the FHE treatment only, accompanied by reduced colonic TLR4 expression with FHE at 1000 mg/kg and with FHJ at both doses. The phosphorylated-total ratios of IκB-α and NF-κB p65 did not differ significantly between groups. FHE and FHJ played protective roles against DSS-induced colitis, which is associated with the preservation of gut barrier function and reduced colonic TLR4 expression.
Diabetic retinopathy (DR) is a metabolic disease of the neurovascular unit, in which retinal microvascular dysfunction and neurodegeneration are interconnected processes that contribute to disease progression. Oxidative stress is a major pathogenic driver of DR; however, whether reactive oxygen species (ROS)-mediated microvascular leakage directly contributes to retinal neurodegeneration remains unclear. Here, we investigated whether targeting ROS-mediated microvascular leakage through inhibition of the ROS–transglutaminase 2 (TGase2) pathway can ameliorate hyperglycemia-induced retinal neurodegeneration in human retinal endothelial cells (HRECs) and diabetic mice. In HRECs, ROS-dependent activation of TGase2 was required for endothelial hyperpermeability. In diabetic mouse retinas, hyperglycemia induced TGase2 activation, stress fiber formation, vascular endothelial-cadherin disassembly, and microvascular leakage, all of which were effectively suppressed by pharmacological inhibition of the ROS-TGase2 pathway or TGase2-specific siRNA. Consistently, diabetic TGase2-null mice exhibited complete protection against retinal microvascular leakage. In contrast, pharmacological inhibition or genetic deletion of TGase2 failed to suppress hyperglycemia-induced inflammatory responses, reactive gliosis, retinal ganglion cell apoptosis, or retinal thinning in diabetic mice. These findings reveal that oxidative stress induces distinct downstream responses in the retinal vasculature and neural retina. TGase2 is a critical effector of ROS-dependent microvascular leakage but is dispensable for hyperglycemia-induced retinal neurodegeneration. Thus, suppression of ROS–TGase2-mediated microvascular dysfunction alone is insufficient to prevent retinal neurodegeneration, indicating that vascular leakage and neurodegeneration are mechanistically dissociable consequences of oxidative stress in DR.
Atorvastatin, a widely prescribed HMG-CoA reductase inhibitor, causes statin-associated muscle symptoms and, less commonly, hepatic and renal toxicity, effects attributed to mitochondrial dysfunction and oxidative stress; strategies to prevent this multisystem injury are needed. This study evaluated whether N-acetylcysteine (NAC) and coenzyme Q10 (CoQ10), alone and in combination, protect against atorvastatin-induced toxicity in male BALB/c mice and C2C12 myoblasts. Mice (n = 30) received, by oral gavage once daily for 14 days, vehicle, atorvastatin (100 mg/kg/day), atorvastatin plus NAC (200 mg/kg/day), atorvastatin plus CoQ10 (100 mg/kg/day), or the triple combination. Outcomes included survival, body weight, rotarod performance, serum creatine kinase, erythrocyte oxidative-stress markers, semi-quantitative histopathology, TUNEL apoptosis, and VEGF immunohistochemistry in liver, kidney, and skeletal muscle, complemented by in vitro atorvastatin cytotoxicity and antioxidant cytoprotection assays in C2C12 myoblasts (atorvastatin 50–200 µg/mL; CoQ10 12.5–50 µg/mL; NAC 100–400 µg/mL). Atorvastatin produced significant histopathological injury and increased apoptotic and VEGF immunoreactivity in all three tissues (p < 0.0001–0.005), effects markedly attenuated by combined NAC plus CoQ10. Glutathione peroxidase activity was significantly reduced by atorvastatin and restored by combination therapy (p < 0.05); catalase, malondialdehyde, and superoxide dismutase showed non-significant favorable trends. In C2C12 myoblasts, atorvastatin produced concentration-dependent cytotoxicity (IC50 ≈ 65 µg/mL), substantially reversed by NAC plus CoQ10 (≈89% viability restoration, p = 0.0025). These findings indicate that combined NAC and CoQ10 confer structural, apoptotic, and cytoprotective protection against atorvastatin-induced toxicity, supporting further mechanistic and translational investigation of combined antioxidant strategies in this high-dose supratherapeutic model; extrapolation to routine clinical statin intolerance will require confirmation at clinically relevant exposures.
