Iron overload (IO) is associated with cardiovascular diseases, including heart failure. Our study’s aim was to examine the mechanism by which IO triggers cell death in H9c2 cells. IO caused accumulation of intracellular and mitochondrial iron as shown by the use of iron-binding fluorescent reporters, FerroOrange and MitoFerroFluor. Expression of cytosolic and mitochondrial isoforms of Ferritin was also induced by IO. IO-induced iron accumulation and cellular ROS was rapid and temporally linked. ROS accumulation was detected in the cytosol and mitochondrial compartments with CellROX, DCF-DA and MitoSOX fluorescent dyes and partly reversed by the general antioxidant N-acetyl cysteine or the mitochondrial antioxidant SkQ1. Antioxidants also reduced the downstream activation of apoptosis and lytic cell death quantified by Caspase 3 cleavage/activation, mitochondrial Cytochrome c release, Annexin V/Propidium iodide staining and LDH release of IO-treated cells. Finally, overexpression of MitoNEET, an outer mitochondrial membrane protein involved in the transfer of Fe-S clusters between mitochondrial and cytosol, was observed to lower iron and ROS accumulation in the mitochondria. These alterations were correlated with reduced IO-induced cell death by apoptosis in MitoNEET-overexpressing cells. In conclusion, IO mediates H9c2 cell death by causing mitochondrial iron accumulation and subsequent general and mitochondrial ROS upregulation.

Adiponectin has been shown to mediate cardioprotective effects and levels are typically reduced in patients with cardiometabolic disease. Hence, there has been intense interest in developing adiponectin-based therapeutics. The aim of this translational research study was to examine the functional significance of targeting adiponectin signaling with the adiponectin receptor agonist ALY688 in a mouse model of heart failure with reduced ejection fraction (HFrEF), and the mechanisms of cardiac remodeling leading to cardioprotection. Wild-type mice were subjected to transverse aortic constriction (TAC) to induce left ventricular pressure overload (PO), or sham surgery, with or without daily subcutaneous ALY688-SR administration. Temporal analysis of cardiac function was conducted via weekly echocardiography for 5 weeks and we observed that ALY688 attenuated the PO-induced dysfunction. ALY688 also reduced cardiac hypertrophic remodeling, assessed via LV mass, heart weight to body weight ratio, cardiomyocyte cross sectional area, ANP and BNP levels. ALY688 also attenuated PO-induced changes in myosin light and heavy chain expression. Collagen content and myofibroblast profile indicated that fibrosis was attenuated by ALY688 with TIMP1 and scleraxis/periostin identified as potential mechanistic contributors. ALY688 reduced PO-induced elevation in circulating cytokines including IL-5, IL-13 and IL-17, and the chemoattractants MCP-1, MIP-1β, MIP-1alpha and MIP-3α. Assessment of myocardial transcript levels indicated that ALY688 suppressed PO-induced elevations in IL-6, TLR-4 and IL-1β, collectively indicating anti-inflammatory effects. Targeted metabolomic profiling indicated that ALY688 increased fatty acid mobilization and oxidation, increased betaine and putrescine plus decreased sphingomyelin and lysophospholipids, a profile indicative of improved insulin sensitivity. These results indicate that the adiponectin mimetic peptide ALY688 reduced PO-induced fibrosis, hypertrophy, inflammation and metabolic dysfunction and represents a promising therapeutic approach for treating HFrEF in a clinical setting.

Nonalcoholic steatohepatitis (NASH) is severe liver metabolic disorder, however, there are still no effective and safe drugs for its treatment. Previous clinical trials used various therapeutic approaches to target individual pathological mechanisms, but these approaches were unsuccessful because of the complex pathological causes of NASH. Combinatory therapy in which two or more drugs are administered simultaneously to patients with NASH, however, it carries the risk of side effects associated with each individual drug. To solve this problem, we identified gossypetin as an effective dual-targeting agent that activates AMP-activated protein kinase (AMPK) and decreases oxidative stress. Administration of gossypetin decreased hepatic steatosis, lobular inflammation and liver fibrosis in the liver tissue of mice with CDHFD and MCD diet-induced NASH. Gossypetin functioned directly as anti-oxidant agents, decreasing hydrogen peroxide and palmitate-induced oxidative stress in the AML12 cells and liver tissue of MCD diet fed mice without regulating the antioxidant response factors. In addition, gossypetin acted as a novel AMPK activator by binding to the allosteric drug and metabolite (ADaM) site, which stabilizes the activated structure of AMPK. Our findings demonstrate that gossypetin has the potential to serve as a novel therapeutic agent for NAFLD/NASH. Significance Statement This study demonstrates that gossypetin has preventive effect to progression of NASH as a novel AMPK activator and antioxidants. Our findings implicate that simultaneous activation of AMPK and oxidative stress using gossypetin has the potential to serve as a novel therapeutic approach for NAFLD/NASH patients.

Extracellular vesicles (EV) are emerging regulators of metabolic homeostasis through their bioactive cargo. This study first investigated the lipidomic profile and functional effects of plasma EV derived from adiponectin‐knockout (KO) mice to identify EV‐associated lipid signatures linked to metabolic dysfunction. Lipidomic profiling revealed that KO EV were enriched in sphingolipids and polyunsaturated phospholipids compared to wild‐type (WT) EV. To evaluate functional consequences, recipient cell assays were conducted using macrophages, skeletal muscle cells, and pancreatic beta cells. KO EV showed an increased uptake in RAW 264.7 macrophages and induced elevated reactive oxygen species (ROS) and activation of NF‐κB and IRF inflammatory pathways. In L6 skeletal muscle cells, WT EV increased ATP production, while KO EV failed to elicit this effect. Furthermore, KO EV impaired glucose‐stimulated insulin secretion in INS‐1 pancreatic beta cells. These findings suggested that altered lipid composition in EV from KO mice contributes to oxidative stress, inflammation, and impaired metabolic regulation in recipient cells. Next, translational relevance was established by documenting that plasma EV from patients with metabolic syndrome exhibited lipidomic remodeling features in parallel to the murine KO phenotype, in particular enriched PUFA‐containing lipids. Together, these findings identify a conserved adiponectin‐EV lipid composition axis regulating oxidative stress, inflammation, and impaired metabolic regulation. The new knowledge presented in this study has implications for biomarker discovery and therapeutic targeting in metabolic disease.

High-fructose corn syrup (HFCS) consumption is a risk factor for obesity and diabetes, yet the underlying mechanisms, especially at the specific organ level, are incompletely understood. Catabolism of dietary fructose primarily occurs in the small intestine and liver, with fructose breakdown in the liver being pathological, while small intestinal fructose clearance protects the liver. Here, we report that inhibition of fructose catabolism specifically in the murine small intestine unexpectedly mitigates fructose-induced obesity and insulin resistance. Such phenotypes are attributed to decreased dietary fat absorption by the shortening of ileal lacteals. Fecal transplantation experiments revealed that the microbiome altered by blunted host intestinal fructose catabolism decreases ileal macrophages essential for lacteal growth. Thus, altered intestinal lacteal architecture likely contributes to the synergistic effects of high fat and sugar on metabolic disorders. It may also be relevant to the clinical evidence that pharmacologic suppression of fructose catabolism mitigates diet-induced obesity.

Background/Objectives: Numerous studies have documented cardioprotective effects of adiponectin in animal models of cardiometabolic disease (CMD). Adiponectin receptor agonist ALY688 has demonstrated functional significance against pressure overload-induced cardiac remodeling events in a mouse model of heart failure with reduced ejection fraction (HFrEF), potentially through modulation of the systemic metabolome. However, the specific metabolites and their pathophysiological contribution to cardioprotection in cardiac hypertrophy or heart failure remain unclear. This study aimed to characterize systemic metabolic alterations across five tissues in HFrEF and determine how ALY688 modifies these pathways to mediate cardioprotection in the transverse aortic constriction (TAC) model. Methods: Targeted metabolic profiling was performed on heart, liver, muscle, epididymal white adipose tissue (eWAT), and serum collected five weeks post-surgery from wild-type male C57BL/6 mice. Mice underwent either Sham or TAC-induced left ventricular pressure overload, with or without daily subcutaneous ALY688 administration. Metabolites were quantified using liquid chromatography–tandem mass spectrometry (LC–MS/MS) and statistically analyzed at the tissue level. Results: Consistent with pathological cardiac remodeling, the comprehensive metabolomic analysis revealed that TAC induced widespread disruption of systemic metabolic homeostasis. ALY688 treatment significantly modified several key metabolite classes, including triglycerides (TGs) and glycosylceramides (HexCer). Notably, ALY688 also altered multiple gut-derived metabolites, including trimethylamine N-oxide (TMAO), 5-aminovaleric acid (5-AVA), and glycodeoxycholic acid (GDCA), highlighting a potential gut–liver–heart axis mediating its cardioprotective effects. Conclusions: These findings demonstrate that ALY688 mitigates TAC-induced metabolic dysregulation across multiple tissues. The identified metabolic signatures suggest that ALY688 exerts cardioprotective effects, at least in part, through restoration of systemic metabolic homeostasis and engagement of a gut–liver–heart metabolic axis. These results provide mechanistic insight into adiponectin receptor agonism and support further exploration of ALY688 as a potential therapeutic strategy for HFrEF.