Non-alcoholic fatty liver disease (NAFLD) frequently coexists with type 2 diabetes mellitus (T2DM), posing a significant metabolic disorder with limited dietary intervention options. Cordycepin, a food‑derived nucleoside from the edible fungus Cordyceps militaris, exhibits hypoglycemic and hypolipidemic effects, but its role in T2DM combined with NAFLD remains unknown. Here, we established a mouse model of T2DM combined with NAFLD in male KM mice using high-fructose and high‑fat diet, and streptozotocin. Both cordycepin (COR) and Cordyceps militaris water extract (CWE) attenuated glucose intolerance, dyslipidemia, hepatic steatosis, liver injury, inflammatory response and oxidative stress, with cordycepin showing superior efficacy. Multi‑omics analysis revealed that cordycepin uniquely reshaped the gut microbiota by significantly enriching the c__Clostridia, including g__Acetatifactor, g__Anaerovorax, g__Monoglobus, s__Acutalibacter_muris, and further affected liver metabolism, which was characterized by enrichment of bile acid metabolism-related pathways. Targeted bile acid metabolomics demonstrated that cordycepin specifically promoted the production of cholic acid‑7‑sulfate (CA7S), a gut‑restricted secondary bile acid, through activation of the hepatic PXR/Sult2a1 pathway. Notably, integrated correlation analysis revealed a significant positive association between CA7S and c__Clostridia (e.g., g__Monoglobus, g__Lachnoclostridium, and g__Anaerovorax), suggesting that cordycepin enhances CA7S production by enriching these Clostridia members. And CA7S activated TGR5 to stimulate glucagon‑like peptide‑1 (GLP‑1) secretion, thereby improving glucose and lipid homeostasis. Therefore, these findings demonstrate that dietary cordycepin improves T2DM combined with NAFLD by modulating gut microbiota, particularly Clostridia, and affecting the PXR/Sult2a1/CA7S/GLP‑1 pathway, thereby exerting beneficial effects on glucose and lipid homeostasis.
BACKGROUND:Chronic kidney disease (CKD) is characterized by renal fibrosis as a key pathological feature. Total flavonoids extracted from Astragalus complanatus can effectively alleviate renal fibrosis. However, the anti-fibrotic effect and the underlying specific mechanisms of its main active component, Complanatuside (CPT), remain unclear. This study aims to investigate the role of CPT on apoptosis and fibrosis of kidney in CKD, and the underlying mechanism. METHODS:The protective effects of CPT against CKD were investigated using mouse and cell models of CKD, and its key targets and mechanisms were identified. RESULTS:The results showed that CPT ameliorated renal fibrosis in UUO mice and TGF-β1-induced fibrosis in HK2 cells. Notably, our single-cell RNA sequencing analysis revealed that CPT significantly reduced failed-repair tubular cells and inhibited apoptosis, accompanied by marked activation of KLK1 gene expression. We found that CPT binds to KLK1, activates its expression, reduces PTEC apoptosis, and thereby attenuates renal fibrosis. In line with this, in vitro studies showed that overexpressing KLK1 reduced TGF-β1-induced fibrosis and apoptosis, whereas knocking down KLK1 reversed CPT's renal protective effect. Further bioinformatics analysis indicated that KLK1 promotes BDKRB2 expression. Knocking down BDKRB2 exacerbated TGF-β1-induced fibrosis and apoptosis. Additionally, when investigating the relationship between KLK1 and BDKRB2, we found a direct interaction between them. Furthermore, downregulation of BDKRB2 counteracted the inhibitory effects of KLK1 overexpression on cell apoptosis and renal fibrosis. CONCLUSION:This study reveals that CPT binds to KLK1, promotes BDKRB2 expression, thereby reducing PTEC apoptosis and improving renal fibrosis.
Aging is characterized by progressive cognitive decline and metabolic dysregulation, contributing to increased vulnerability to age-related disorders. β-position palmitic acid -containing structured lipids (sn-2 palmitate), naturally enriched in human milk fat, have been reported to modulate inflammation and lipid metabolism. However, whether sn-2 palmitate-rich lipids exert beneficial effects beyond early development, particularly in the context of aging-related decline, remains unclear; further, its effects in aged populations or senescence models remain largely unknown. Therefore, we investigated the potential anti-aging effects of sn-2 palmitate-enriched lipid in senescence-accelerated mouse prone 8 (SAMP8)-a model of age-related functional decline. Eight-week-old SAMP8 mice were fed a sn-2 palmitate-enriched lipid supplemented diet for eight weeks. Behavioral tests, hippocampal biochemical analyses, and histological assessments were performed. sn-2 palmitate-enriched lipid supplementation significantly improved cognitive performance and reduced hippocampal expression of senescence markers (p16, p21) and pro-inflammatory cytokines (IL-6, TNF-α). Furthermore, sn-2 palmitate enhanced NAD⁺/NADH ratios and increased Sirt1/3 deacetylase activities, accompanied by upregulation of mitochondrial biogenesis-related factors (PGC-1α, NRF1, TFAM). These findings suggest that sn-2 palmitate-enriched lipid may attenuate aging-associated cognitive and physiological decline through modulation of NAD⁺ metabolism and mitochondrial function.
The effects of docosahexaenoic acid (DHA) on seizures and epilepsy remain controversial and appear to depend on the specific context. In this study, we investigated the effects of maternal DHA intake on febrile seizures and post-febrile seizure susceptibility. Mice exposed to DHA during pregnancy showed considerably higher brain DHA and 17β-estradiol (E2) levels than controls, along with a marked delay in the onset of febrile seizures. These effects were abolished by letrozole, an inhibitor of cytochrome P450 family 19 subfamily A, suggesting that the DHA-induced increase in E2 reduces susceptibility to febrile seizures. Maternal DHA intake also suppressed neuroinflammation after febrile seizures and reduced seizure susceptibility later in life following pentylenetetrazol treatment. These protective effects also required E2 synthesis, as they were abolished by letrozole, indicating that the DHA-induced increase in E2 reduces long-term seizure susceptibility even after febrile seizures have occurred. In children with febrile seizures, serum DHA and E2 levels were markedly lower than those in controls. In addition, serum interleukin-1 beta levels were inversely correlated with serum E2 concentrations. Together, DHA can delay febrile seizure onset and attenuate inflammation in an E2-dependent manner. Maternal DHA intake during pregnancy may therefore contribute to healthy brain development in children.
The enzyme 3-hydroxyacyl-CoA-dehydratase 3 (HACD3) is involved in fatty acid synthesis, but its systemic role in metabolism is unknown. This study investigated the physiological function of HACD3 in energy homeostasis. Systemic HACD3 deficiency protected mice from diet-induced obesity by increasing energy expenditure and activating adipose thermogenesis. Conversely, deleting HACD3 specifically in leptin receptor-expressing neurons caused obesity, hyperphagia, and leptin resistance. In adipocytes, HACD3 cell-autonomously repressed thermogenesis by forming a complex with Keratin 1 (KRT1), which sequestered thermogenic transcription factors and maintained repressive chromatin. HACD3 ablation disrupted this complex, enabling nuclear translocation of PPARγ/PGC-1α and increasing transcription of thermogenic genes. In neurons, HACD3 is required for leptin receptor stability and signalling. HACD3 acts as a critical, tissue-specific regulator that simultaneously governs both sides of the energy balance equation-suppressing energy expenditure in adipose tissue while facilitating anorexigenic signalling in the brain. This dual function identifies HACD3 as a novel, multifaceted target for therapeutic intervention in metabolic disorders.
Osteoporosis is becoming one of the major global health concerns with accelerating of the aging population and there is an urgent need for novel countermeasures. Salidroside (SAL) and Apigenin (AP) are compounds identified in Ligustri Lucidi Fructus (LLF), a dietary herb that has historically been used and is currently used in osteoporosis management. However, their effects on bone loss remain largely unexplored. To this end, ovariectomized (OVX) mice and osteoclasts differentiated from RAW 264.7 were used to establish the osteoporotic model in vivo and in vitro. We found that SAL and AP treatments reduce the numbers of TRAP-positive cells, F-actin rings and bone resorption pits, and suppress the expression levels of c-Fos, Nfatc1 and Ctsk in osteoclasts. In addition, SAL and AP can improve bone quality and decrease serum levels of CTX-1 and TRAP-5b in OVX mice. These compounds further increase the expression levels of Sema3A, Nrp1 and PlexinA1 in osteoclasts and osteoporotic animals. In conclusion, SAL and AP limit osteoclastic bone resorption to ameliorate bone quality via upregulation of the Sema3A/Nrp1/PlexinA1 signaling pathway, providing a novel strategy for osteoporosis management.
Polyphenols are metabolites derived from plant-based sources studied in cancer research for their anti-inflammatory, antioxidant, and antiproliferative properties. While previous studies have focused more on their impact on gastrointestinal diseases like inflammatory bowel disease and malignancies such as colon cancer, there is less attention on their role in neurological diseases and malignancies more distant from the gastrointestinal tract, like brain cancer. Recent work indicates potential for polyphenols to beneficially modulate the gut microbiome and improve neurological disorders through the gut-brain axis. Glioblastoma (GBM), classified as a grade 4 brain tumor by the World Health Organization, poses significant challenges with inefficient conventional treatments that yield a low five-year survival rate. Recent meta-analyses demonstrate the potential of various plant foods to reduce the risk of glioma. However, specific dietary recommendations for brain cancer remain elusive, and the mechanisms of action of plant foods and their compounds, as well as their impact through the gut-brain axis, must still be explored. This review will discuss the impact of polyphenols on the gut-brain axis and analyze the potential benefits of implementing them as preventive and therapeutic GBM interventions with relation to the gut microbiome.
High-grain diets widely applied in intensive ruminant farming frequently induce subacute ruminal acidosis, accompanied by intestinal inflammation and barrier damage, while the underlying molecular mechanisms remain unclear. Given the central role of the cGAS-STING cascade in inflammatory injury, this work explored its function in high-grain-induced colonic damage using lactating Hu sheep. In vivo, 12 healthy sheep were randomly divided into two equal groups, fed with either a low-grain (grain:forage=3:7, LG) or high-grain (grain:forage=7:3, HG) diet for 8 weeks, followed by comprehensive detection of ruminal pH, serum inflammatory profiles, colonic histopathological changes, and the expression of key molecules in the cGAS-STING pathway. To further validate the underlying mechanism, an in vitro inflammatory model was established by LPS stimulation of colonic epithelial cells. Mechanistically, ethidium bromide (EB)-mediated mtDNA depletion assay and specific cGAS/STING inhibitors were used to verify that mtDNA release acts as the essential upstream trigger for cGAS-STING pathway activation. This study revealed that HG diet reduced rumen pH below 5.6 for over 3 h daily, successfully establishing the subacute ruminal acidosis model. HG diet elevated LPS levels in rumen fluid, blood, and colon contents, and increased the cytoplasmic mtDNA/nDNA ratio in colon tissue, which further activated the cGAS‑STING/NF‑κB pathway and consequently triggered colonic inflammation and intestinal barrier dysfunction. In vitro assays further validated that EB or cGAS/STING inhibitors alleviated LPS-triggered inflammation and barrier impairment. Collectively, the cGAS-STING pathway is a key therapeutic target for maintaining ruminant intestinal homeostasis and preventing high-grain-related enteric disorders.
Both diet and aging shape the gut microbiota, yet how their combined remodeling propagates across microbial function to host barrier and brain outcomes remains poorly understood. Despite abundant links between Short-chain fatty acids (SCFAs) and intestinal health, integrative studies that connect community ecology with SCFA linked metabolism, epithelial signaling, systemic inflammation, behavior, and test causal reversibility are limited. In this study, we assessed gut microbiota and function alongside host tissues and behavior. In mice fed a high-fat diet (HFD), particularly in the 12-month-old cohort, we observed hippocampal-dependent cognitive and locomotor deficits (longer escape latency, fewer platform crossings, reduced target-quadrant time; lower distance, speed and center time), accompanied by systemic inflammation, with serum lipopolysaccharide (LPS) and cytokines (IL-6 and TNF-α) elevated and associated with adiposity. We then profiled the gut microbiota and its functions alongside host tissues and behavior, finding that HFD and age reduced α-diversity and shifted β-diversity, with a selective depletion of Muribaculaceae and depressed SCFA-linked pathways. Muribaculaceae abundance positively correlated with predicted SCFA-related pathways, while qRT-PCR of microbial fermentation genes supported concurrent functional alterations. In the colon, ELISA-measured butyrate level, SCFA receptors Ffar2, Ffar3 and tight-junction genes Tjp1 and Ocln were downregulated, with ZO-1 and occludin mislocalization, while serum LPS and inflammatory cytokines increased and associated with adiposity. Notably, an intervention arm showed that sodium butyrate supplementation attenuated cytokinemia, restored Ffar2, Ffar3 and tight-junction expression, improved ZO-1 and occludin integrity, and rescued behavioral performance. Collectively, these findings support an association between Muribaculaceae depletion, reduced SCFA-related functional signatures, impaired barrier associated markers, systemic inflammation, and behavioral deficits under HFD and age-associated conditions. In an intervention setting, butyrate supplementation partially ameliorated inflammatory and barrier-related readouts and improved behavioral performance.
Early-life maternal high-saturated fat (HSF) exposure increases offspring susceptibility to type 2 diabetes, but mechanisms linking it to β-cell dysfunction remain poorly defined. This study aimed to identify key miRNAs mediating this programming and evaluate their therapeutic potential. Female mice were fed control, high-lard, or high-palm oil diets during gestation and lactation. Islets from adult male offspring were isolated for miRNA sequencing to identify candidates. β-cell-specific overexpression of miR-1a-3p was achieved via AAV8-Ins1 vector. Proteomics analysis was performed to screen its downstream targets. miR-1a-3p was the only miRNA showing interactive effects between maternal and offspring diets. It was upregulated in male offspring islets, further exacerbated by late-adulthood HFD re-exposure. Functionally, miR-1a-3p overexpression increased fasting glucose, impaired glucose and insulin tolerance, reduced ATP production and mitochondrial membrane potential, without affecting apoptosis. NBR1 was confirmed as a direct target of miR-1a-3p. NBR1 silencing mimicked miR-1a-3p's detrimental effects on β-cell mitochondria and function. Inhibition of miR-1a-3p alleviated HFD-induced β-cell dysfunction. miR-1a-3p mediates β-cell dysfunction programmed by early-life maternal HSF exposure through targeting NBR1 and disrupting mitochondrial function, representing a potential therapeutic strategy for preventing type 2 diabetes transmission.
This study aimed to synthesize and quantitatively assess the available evidence on the effects of phytosterol supplementation on hepatic lipid metabolism and obesity-related metabolic outcomes in obese rodent models, integrating biochemical, histological, and molecular evidence. A systematic search was conducted in electronic databases (PubMed, EMBASE, and Web of Science). Data on study design, population, intervention, outcomes, and risk of bias were extracted and analyzed. A quantitative meta-analysis was performed. Meta-analysis showed reductions in body weight, serum triglycerides, total cholesterol, LDL-C, VLDL-C, glucose, liver weight, hepatic cholesterol, hepatic triglycerides, and nonalcoholic fatty liver disease activity score. No significant changes were observed for adiposity index, HDL-C, insulin, or hepatic expression of PPARα, FAS, and SREBP1c. Conversely, CPT1A expression was significantly increased following PS supplementation. Subgroup analyses indicated that the beneficial effects on lipid and hepatic outcomes were generally consistent across rodent species (mice, rats, and hamsters), obesity induction models, and routes of administration, although the magnitude of responses varied between strains, with C57BL/6 mice showing more pronounced metabolic improvements. Additional analyses suggested that treatment duration and phytosterol composition may modulate specific outcomes, whereas dose-response meta-regression identified dose-dependent associations for serum and hepatic cholesterol, and PPARα expression in dietary supplementation studies. Overall, the available preclinical evidence suggests that phytosterol supplementation may improve several metabolic and hepatic outcomes in rodent models of obesity. However, the substantial heterogeneity across studies highlights the need for standardized experimental protocols and future clinical studies before these findings can be translated to human health.
Ruminant epithelia preferentially catabolize butyrate to fuel metabolism, yet the mechanism by which the rumen epithelium establishes this preference remains unclear. Here, we identify ACSF2 as a mitochondrial acyl‑CoA synthetase (ACS) that catalyzes the activation of butyrate to butyryl‑CoA, thereby enabling rumen butyrate preference. We found that ACSF2 is markedly enriched in the forestomachs across ovine organs, with expression far exceeding other ACSs in the rumen epithelium, and it is rising during postnatal establishment of fermentative function. Single‑cell transcriptomics and immunostaining localize ACSF2 to the mitochondria‑rich layers, where it is co‑expressed in mitochondria with ketogenesis genes, notably the rate‑limiting enzyme HMGCS2. Further gain‑ and loss‑of‑function experiments show that ACSF2 activates butyrate to butyryl‑CoA, enhances butyrate‑supported growth, and is required for efficient butyrate consumption, cell fitness, and ketogenesis under butyrate‑dependent conditions. These findings define ACSF2 as a key mitochondrial gatekeeper for butyrate utilization in the rumen epithelium, providing a molecular mechanism for butyrate‑biased energy metabolism during rumen maturation.
Maternal protein restriction during gestation in rodents is widely used as a model of developmental programming; however, its metabolic effects in offspring are often modest. In humans, protein deficiency is frequently accompanied by deficiencies in essential micronutrients. This study examined whether maternal choline insufficiency, an essential micronutrient whose deficiency in adult rodents induces metabolic dysfunction-associated steatotic liver disease, modifies the metabolically restrained hepatic phenotype conferred by maternal protein restriction in offspring. Pregnant ICR mice were fed a control, a protein-restricted diet (8% of total energy from protein), or a protein- and choline-restricted diet (25% of the standard choline content, w/w) from gestational day 1. Male offspring were weaned onto a high-fat, high-sucrose diet, as a standardized metabolic challenge, and hepatic histology, biochemical parameters, and metabolic- and oxidative stress-related gene and protein expression were analyzed. Maternal protein restriction alone did not induce hepatic steatosis in offspring and was associated with reduced expression of lipid metabolism-related genes (Apoa4) and decreased hepatic activity of xanthine oxidoreductase (XOR), a key enzyme involved in reactive oxygen species production. In contrast, maternal choline insufficiency combined with protein restriction induced hepatic steatosis compared with maternal protein restriction alone, accompanied by lipid droplet hypertrophy, increased expression of inflammatory genes (Il1b and Il18), and reactivation of hepatic XOR activity, together with restoration of metabolic gene expression toward control levels, in the offspring. Together, these findings demonstrate that maternal choline insufficiency abolishes the metabolically restrained hepatic phenotype induced by gestational protein restriction and promotes progression to hepatic steatosis in offspring.
Cyanidin-3-O-galactoside (C3G) has a variety of biological activities. Pulmonary fibrosis (PF) is a fatal interstitial lung disease. To define its pathogenic networks, we performed transcriptomic sequencing of lung tissues from five mouse groups: WT_Control, WT_Model, WT_Model_C3G, Control_Ccl3-/-, Model_Ccl3-/-. Comprehensive assessment of immune infiltration, weighted gene co-expression network, and functional enrichment verified that PF is tightly linked to immune microenvironment dysregulation. Seven machine learning algorithms identified five core immune-related targets: Ccl3, Xcl1, Pyy, Il31ra, Ppbp. Subsequent analysis prioritized Ccl3 and Ppbp as the key core pathogenic genes. Molecular docking clarified their binding modes and key interaction sites with C3G. Histopathological and biochemical assessments showed that the WT_Model group exhibited elevated expressions of Ccl3 and Ppbp, accompanied by marked inflammatory infiltration and collagen deposition. C3G intervention significantly ameliorated these PF phenotypes. Ccl3 knockout improved survival and ameliorated fibrotic pathology. Interaction modeling and correlation analyses identified Slc2a3 as a key Ccl3 downstream target. Western blot (WB) and immunohistochemical validation revealed reduced expression of Ccl3, Slc2a3, and α-SMA proteins in Model_Ccl3-/- compared to WT_Model, which suggested Ccl3 may positively regulate the expression of Slc2a3. Through transcriptome and external metabolome verification, it was found that Slc2a3 can regulate PF through metabolic pathways. In conclusion, this study confirmed the potential role of C3G in regulating Ccl3-related inflammation and metabolic pathways in bleomycin-induced PF, which is expected to become a new strategy for targeted therapy of PF and provide a theoretical basis for the development of clinical treatment.
Metabolic dysfunction-associated fatty liver disease (MASLD) is a major global health challenge characterized by metabolic imbalance, inflammation, and oxidative stress, yet effective targeted therapies remain limited. Lipoprotein-associated phospholipase A2 (Lp-PLA2) has emerged as a potential regulator of metabolic disorders, but its role and therapeutic relevance in MASLD remain unclear. Integrative bioinformatics analysis of human liver transcriptomic datasets combined with virtual screening, network pharmacology, and molecular docking identified chebulinic acid (CA) as a potential Lp-PLA2-targeting compound. The therapeutic effects and underlying mechanisms of CA were investigated using high-fat diet (HFD)-induced MASLD mouse models and free fatty acid (FFA)-treated Huh7 hepatocytes using metabolic profiling, histological analysis, Seahorse bioenergetic assessment, adeno-associated virus (AAV)-mediated gene overexpression, and cellular thermal shift assay. Lp-PLA2 was identified as a key regulator associated with MASLD progression and metabolic pathway dysregulation. CA exhibited strong binding affinity to Lp-PLA2 and significantly ameliorated metabolic dysfunction, hepatic steatosis, inflammation, and oxidative stress in both in vivo and in vitro models. Mechanistically, CA restored mitochondrial respiration and glycolytic capacity while reducing abnormal HK2 expression. HK2 overexpression abolished the protective effects of CA, indicating that excessive HK2 expression contributes to metabolic imbalance under metabolic stress conditions. Furthermore, CA - binding to Lp-PLA2 through the Glu304 residue was required for its metabolic protective effects and was associated with regulation of the Lp-PLA2-HK2-associated pathway. This study identifies Lp-PLA2-associated HK2 dysregulation as a potential contributor to MASLD metabolic dysfunction and demonstrates that CA improves hepatic metabolic homeostasis through modulation of Lp-PLA2 signaling.
Leptin resistance is a hallmark of obesity. It is characterized by diminished responsiveness to leptin and disrupts energy homeostasis. While multiple pathways contribute to leptin resistance, the transcriptional repression of the leptin receptor (LepRb) is a critical defect that impairs downstream signal transduction. Despite the established metabolic benefits of intermittent fasting, whether fasting directly influences leptin signaling and the underlying mechanisms remains unclear. Here, we investigated whether alternate-day fasting (ADF), a form of intermittent fasting, restores central leptin signaling by upregulating hypothalamic LepRb expression. In male C57BL/6J mice with diet-induced obesity, ADF significantly enhanced leptin-induced reductions in food intake and body weight, while increasing hypothalamic STAT3 phosphorylation, a key downstream mediator of leptin signaling. These metabolic improvements occurred independent of changes in body weight and adiposity, indicating a direct effect of fasting on leptin signaling. Mechanistically, ADF selectively reduced repressive H3K27 methylation at the LepRb promoter, leading to increased LepRb expression in hypothalamic nuclei critical for energy homeostasis. This epigenetic shift was associated with induction of the histone demethylase Jumonji Domain-Containing Protein three (JMJD3). To establish causality, we utilized stereotaxic injection of AAV-shRNA targeting Jmjd3 into the mediobasal hypothalamus. Knockdown of Jmjd3 abolished ADF-induced H3K27 demethylation, prevented LepRb upregulation, and attenuated the metabolic effects of ADF. Collectively, these findings identify JMJD3-dependent epigenetic regulation as a link between ADF and improved leptin signaling. Our study establishes histone modification and chromatin remodeling as a fundamental mechanism by which intermittent fasting reverses leptin resistance, providing a novel framework for leptin-based obesity therapies.
Linarin, a natural flavonoid, has been reported to exert antioxidant and anti-diabetic effects. However, its role in obesity-related cognitive dysfunction remains unclear. Here, we investigated whether linarin protects against high-fat diet (HFD)-induced cognitive impairment by restoring hippocampal insulin signaling and synaptic plasticity. HFD-fed mice were orally administered linarin at 100 mg/kg/d, and an insulin-resistance (IR)-like model was established in primary hippocampal neurons. Linarin reduced blood glucose and plasma free fatty acid levels in HFD-fed mice and restored hippocampal insulin levels. In parallel, linarin increased the phosphorylation of IRS-1, Akt, and GSK-3β in the hippocampus, accompanied by improved spatial memory, restored hippocampal long-term potentiation, increased dendritic spine density in the CA1 region, and elevated expression of synapse-related proteins, including PSD95, GluN1, and GluN2B. In primary hippocampal neurons exposed to IR conditions, linarin at 7.5 µM restored insulin signaling, promoted neurite outgrowth, and improved dendritic spine morphology. Furthermore, pharmacological inhibition of IRS/Akt/GSK-3β signaling with LY294002 attenuated the protective effects of linarin on dendritic spine morphology in IR neurons. Collectively, these findings suggest that linarin alleviates HFD-induced cognitive dysfunction, at least in part, by improving hippocampal insulin sensitivity and facilitating synaptic function, indicate linarin could be a possibly therapeutic agent against obesity-associated cognitive impairment.
Riboflavin metabolism governs a myriad of redox-driven biochemical processes fundamental to energy production, cellular signaling, and biosynthesis. Flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN) act as obligatory prosthetic groups for a plethora of regulatory enzymes of key metabolic pathways, correlating riboflavin status directly to cellular energy flux and redox balance. Oxidative stress may disturb physiological activities of riboflavin metabolizing machineries. Chronic stress induces surge in levels of circulatory catecholamines including adrenaline which subsequently undergo auto-oxidation generating free radicals. Cardio-protective efficacy of melatonin is well-documented against cardiovascular diseases. In this study, subcutaneous administration of adrenaline in rats for 10 consecutive days induces an oxidative stress milieu in heart, mimicking a chronic stress model. Adrenaline precipitates antioxidant imbalance, tissue-morphological alterations and disruption of mitochondrial membrane potential accompanied by alterations in tissue riboflavin, FMN and FAD levels and prominent reductions in the activities of riboflavin metabolizing enzymes. Altered levels of these co-factors also disrupt cardiac energy metabolism. However, melatonin protects against these deleterious repercussions of adrenaline. Melatonin safeguards cardiac tissue from inflammation by restraining the surge in interleukin-1 beta, tumor necrosis factor-alpha and interleukin-10 and also from apoptosis by suppression of Caspase-8 and Caspase-3 levels. Intriguingly, isothermal titration calorimetric study revealed spontaneous binding of adrenaline with FAD and FMN. Melatonin also exhibits strong binding affinity for adrenaline. 1H-NMR spectroscopic studies unveiled fascinating findings concerning the site of interactions of adrenaline with FAD, FMN, and melatonin. Findings suggest that melatonin may impede binding of adrenaline with flavin co-enzymes plausibly by potential encounter and sequestration of adrenaline, FMN or FAD by melatonin.
Ergothioneine (ERG) is a dietary thiol that is selectively accumulated in mammalian tissues via a specific transporter and may protect the cells against oxidative and inflammatory burden. In this study, we investigated the protective effects of ERG on high-fat diet (HFD)-induced cardiac fibrosis in the spontaneously hypertensive rats (SHR). ERG treatment (50 mg/kg daily, for 10 weeks) attenuated cardiac remodeling, as evidenced by reduced levels of the fibrosis markers hydroxyproline, α-smooth muscle actin, and galectin-3 increased by HFD. HFD induced obesity and altered plasma concentrations of metabolic hormones (thyroxine, leptin, and FGF21) and these changes were not affected by ERG. ERG suppressed SMAD-2 expression, indicating inhibition of TGFβ-driven profibrotic signaling, and favorably modulated extracellular matrix composition by reducing the collagen I content as well as the collagen I/collagen III ratio. In parallel, ERG enhanced antioxidant defense, as shown by upregulated expression of Sod2, which encodes mitochondrial superoxide dismutase, and reduced expression of the profibrotic Nox4, thereby demonstrating protective actions in the heart. ERG supplementation prevented the HFD-induced increase in the neutrophil-to-lymphocyte ratio, which is a biomarker of the stress response and immune burden. In summary, ERG attenuated HFD-induced maladaptive cardiac remodeling in SHR rats by modulating extracellular matrix composition and reducing fibrosis markers, likely by mitigating the pro-oxidative state. These findings suggest that ERG supplementation could serve as an adjunctive strategy to prevent cardiovascular disease in individuals with hypertension who consume a Western-type diet.
Accumulating evidence links branched-chain amino acids (BCAAs, including leucine, isoleucine, and valine) to obesity, diabetes, and related metabolic disorders; however, their role in metabolic dysfunction-associated steatohepatitis (MASH) remains unclear. Interrogation of human and mouse transcriptomic datasets (GSE147304, GSE263770) revealed suppressed hepatic BCAAs catabolic gene expression in MASH. In a murine model of MASH induced by a methionine- and choline-deficient (MCD) diet, BCAAs catabolic gene expression was suppressed in the liver, accompanied with the accumulation of branched-chain keto acids (BCKAs), the products of BCAAs. Furthermore, MASH was exacerbated in the PP2Cm knockout mice in which BCAAs catabolism was impaired and BCAAs and BCKAs accumulated. Dietary supplementation with BCAAs also exacerbated MCD-induced steatohepatitis with elevated BCAAs and BCKAs abundance in the liver. Mechanistically, BCKAs promoted cell-autonomous inflammatory responses in hepatocytes and macrophages, respectively, and amplified the pro-inflammatory positive feedback loop between these two types of cells. Finally, pharmacological enhancement of BCAAs catabolism with the small molecule BT2 reduced BCKAs abundances and ameliorated liver injury and fibrosis in MASH. Together, this study reveals that the disruption of BCAAs homeostasis exacerbated inflammation and fibrosis in MCD-induced steatohepatitis, at least partially through mutually reinforcing inflammatory responses in hepatocytes and macrophages. The vicious cycle amplified by the dysregulated BCAAs homeostasis provides potential pharmacological and nutritional therapeutic strategies for MASH.
