Disrupted adipokine secretion and inflammatory responses in human adipocyte hypertrophy

Adipocyte hypertrophy is a critical contributor to obesity-induced inflammation and insulin resistance. This study employed a human adipocyte hypertrophy model to investigate the adipokine release, inflammatory responses, and the intracellular singling pathways. Hypertrophic adipocytes exhibited increased lipid content and lipolysis, a decline of anti-inflammatory adipokine adiponectin release and an increase of pro-inflammatory adipokine leptin release compared to mature adipocytes. Moreover, TNFα and LPS exacerbated the decrease in adiponectin secretion by hypertrophic adipocytes while promoting the secretion of leptin, MCP-1 and IL-6, which is associated with impaired activation of p38 and JNK MAPK and persistent activation of ERK and IκBα in hypertrophic adipocytes. These altered adipokine secretions and inflammatory responses within hypertrophic adipocytes may contribute to adipocyte dysfunction in human obesity.

Bidirectional causality of physical exercise in retinal neuroprotection

Physical exercise is recognized as an effective intervention to improve mood, physical performance, and general well-being. It achieves these benefits through cellular and molecular mechanisms that promote the release of neuroprotective factors. Interestingly, reduced levels of physical exercise have been implicated in several central nervous system diseases, including ocular disorders. Emerging evidence has suggested that physical exercise levels are significantly lower in individuals with ocular diseases such as glaucoma, age-related macular degeneration, retinitis pigmentosa, and diabetic retinopathy. Physical exercise may have a neuroprotective effect on the retina. Therefore, the association between reduced physical exercise and ocular diseases may involve a bidirectional causal relationship whereby visual impairment leads to reduced physical exercise and decreased exercise exacerbates the development of ocular disease. In this review, we summarize the evidence linking physical exercise to eye disease and identify potential mediators of physical exercise-induced retinal neuroprotection. Finally, we discuss future directions for preclinical and clinical research in exercise and eye health.

Roseburia hominis improves host metabolism in diet-induced obesity

Next-generation live biotherapeutics are promising to aid the treatment of obesity and metabolic diseases. Here, we reported a novel anti-obesity probiotic candidate, Roseburia hominis, that was depleted in stool samples of obese subjects compared with lean controls, and its abundance was negatively correlated with body mass index and serum triglycerides. Supplementation of R. hominis prevented body weight gain and disorders of glucose and lipid metabolism, prevented fatty liver, inhibited white adipose tissue expansion and brown adipose tissue whitening in mice fed with high-fat diet, and boosted the abundance of lean-related species. The effects of R. hominis could be partially attributed to the production of nicotinamide riboside and upregulation of the Sirtuin1/mTOR signaling pathway. These results indicated that R. hominis is a promising candidate for the development of next-generation live biotherapeutics for the prevention of obesity and metabolic diseases.

Evolving perspectives on evaluating obesity: from traditional methods to cutting-edge techniques

Objective: This review examines the evolution of obesity evaluation methods, from traditional anthropometric indices to advanced imaging techniques, focusing on their clinical utility, limitations, and potential for personalized assessment of visceral adiposity and associated metabolic risks.

Methods: A comprehensive analysis of existing literature was conducted, encompassing anthropometric indices (BMI, WC, WHR, WHtR, NC), lipid-related metrics (LAP, VAI, CVAI, mBMI), and imaging technologies (3D scanning, BIA, ultrasound, DXA, CT, MRI). The study highlights the biological roles of white, brown, and beige adipocytes, emphasizing visceral adipose tissue (VAT) as a critical mediator of metabolic diseases.

Conclusion: Although BMI and other anthropometric measurements are still included in the guidelines, indicators that incorporate lipid metabolism information can more accurately reflect the relationship between metabolic diseases and visceral obesity. At the same time, the use of more modern medical equipment, such as ultrasound, X-rays, and CT scans, allows for a more intuitive assessment of the extent of visceral obesity.

Bioinformatics analysis identifies key secretory protein-encoding differentially expressed genes in adipose tissue of metabolic syndrome

The objective of this study was to identify key secretory protein-encoding differentially expressed genes (SP-DEGs) in adipose tissue in female metabolic syndrome, thus detecting potential targets in treatment. We examined gene expression profiles in 8 women with metabolic syndrome and 7 healthy, normal body weight women. A total of 143 SP-DEGs were screened, including 83 upregulated genes and 60 downregulated genes. GO analyses of these SP-DEGs included proteolysis, angiogenesis, positive regulation of endothelial cell proliferation, immune response, protein processing, positive regulation of neuroblast proliferation, cell adhesion and ER to Golgi vesicle-mediated transport. KEGG pathway analysis of the SP-DEGs were involved in the TGF-beta signalling pathway, cytokine‒cytokine receptor interactions, the hippo signalling pathway, Malaria. Two modules were identified from the PPI network, namely, Module 1 (DNMT1, KDM1A, NCoR1, and E2F1) and Module 2 (IL-7 R, IL-12A, and CSF3). The gene DNMT1 was shared between the network modules and the WGCNA brown module. According to the single-gene GSEA results, DNMT1 was significantly positively correlated with histidine metabolism and phenylalanine metabolism. This study identified 7 key SP-DEGs in adipose tissue. DNMT1 was selected as the central gene in the development of metabolic syndrome and might be a potential therapeutic target.

Characteristics of lipid accumulation induced by high-altitude environment improve the total antioxidant capacity of Ophiocordyceps sinensis

Ophiocordyceps sinensis is a traditional Chinese herbal medicine and nutritional supplement, which is rich in functional components beneficial to health. The biosynthesis of these components is affected by environment factors, especially lipids. This study analyzed the lipid mass spectrometry characteristics and total antioxidant capacity (TAC) of O. sinensis in 5 different altitude environments and explored the important contributions of environmental factors. The pathway of glycerophospholipid metabolism and biosynthesis of secondary metabolites in O. sinensis was activated by altitude (AM) and mean annual temperature (MAT) at high altitudes. This stimulated the degradation of triglycerides (TG) and the biosynthesis of phosphatidylcholine (PC), and phosphatidylethanolamine (PE), promoted the accumulation of free radical scavenging (FRS) abilities and antioxidant components (AC), and increased its TAC. This study reflects the important role of high altitude environment on lipid metabolism and the formation of bioactive components in O. sinensis and provides a scientific basis for exploring its medicinal value and nutritional value.

Emerging roles for fatty acid oxidation in cancer

Fatty acid oxidation (FAO) denotes the mitochondrial aerobic process responsible for breaking down fatty acids (FAs) into acetyl-CoA units. This process holds a central position in the cancer metabolic landscape, with certain tumor cells relying primarily on FAO for energy production. Over the past decade, mounting evidence has underscored the critical role of FAO in various cellular processes such as cell growth, epigenetic modifications, tissue-immune homeostasis, cell signal transduction, and more. FAO is tightly regulated by multiple evolutionarily conserved mechanisms, and any dysregulation can predispose to cancer development. In this view, we summarize recent findings to provide an updated understanding of the multifaceted roles of FAO in tumor development, metastasis, and the response to cancer therapy. Additionally, we explore the regulatory mechanisms of FAO, laying the groundwork for potential therapeutic interventions targeting FAO in cancers within the metabolic landscape.

Caloric restriction alters NCOA2 splicing to regulate lipid metabolism in subcutaneous white adipose tissue

Caloric restriction (CR) promotes longevity and metabolic health by modulating gene expression and cellular processes. However, the role of alternative mRNA splicing in CR-induced metabolic adaptation remains underexplored. In this study, we analyzed RNA sequencing data from the subcutaneous white adipose tissue of CR mice. We identified 6058 differentially expressed genes, with significant upregulation of lipid metabolism pathway genes, such as Elovl6, Fasn, and Srebp1c. We also detected 400 CR-associated alternative splicing events, with the skipped exon and retained intron events predominantly affecting lipid biosynthesis and energy metabolism. Among these events, Ncoa2, a nuclear receptor coactivator involved in lipid metabolism, exhibited increased exon 13 inclusion under CR, favoring the expression of the full-length isoform. Functional assays revealed that full-length NCOA2 enhanced PPARγ-mediated transcriptional activation, while the truncated Δ-NCOA2 isoform exhibited altered coactivator activity. Δ-NCOA2 was found to lack an LXXL motif critical for nuclear receptor interactions, potentially modifying its function. Taken together, these findings indicate that CR-induced alternative splicing fine-tunes metabolic and transcriptional networks, thereby contributing to lipid homeostasis and energy adaptation. Our study highlights a novel regulatory layer by which CR modulates metabolism through coordinated transcriptional and splicing alterations, offering new insights into the molecular mechanisms underlying the beneficial effects of CR on aging and metabolic health. Further investigations are warranted to determine the tissue-specificity of the CR-induced splicing changes and their potential implications for metabolic disorders and lifespan extension.

Luteolin modulates the TGFB1/PI3K/PTEN axis in hormone-induced uterine leiomyomas: Insights from a rat model

Uterine leiomyomas (UL), or fibroids, are non-cancerous tumors of the uterine smooth muscle, affecting approximately 70% of women of reproductive age. They are the most prevalent solid tumors in the gynecological tract and a major indication for hysterectomy. The pathogenesis of UL involves uterine inflammation, uncontrolled cell division, and suppressed apoptosis. This study evaluated the protective effects of luteolin, a flavonoid known for its anti-inflammatory and antioxidant properties, against diethylstilbestrol and progesterone-induced UL in female rats. Twenty-four female Wistar rats were divided into four groups: (1) control, (2) luteolin (10 mg/kg, PO), (3) UL (diethylstilbestrol 1.35 mg/kg + progesterone 1 mg/kg, SC), and (4) UL + luteolin (10 mg/kg). The treatment duration was five weeks. Histological analyses were performed using hematoxylin and eosin (H&E) staining and Masson's Trichrome staining to evaluate uterine architecture and fibrosis. Histological results demonstrated normal uterine architecture in the control and luteolin groups, with marked neoplastic cell proliferation and fibrosis in the UL group, significantly mitigated by luteolin treatment. Luteolin reduced uterine weights and exhibited antioxidant, anti-inflammatory, pro-apoptotic, and anti-proliferative effects. Immunohistochemical analysis revealed that luteolin significantly reduced α-SMA protein expression, suggesting its role in modulating fibrotic pathways by inhibiting TGF-β1 and PI3K and enhancing PTEN production. These findings highlight luteolin's potential as a non-invasive therapeutic option for UL and suggest the need for further clinical studies to establish its efficacy, optimize dosage, and evaluate its safety profile in humans.

Irisin alleviates steroid-induced vascular dysfunction by regulating the αVβ5-c-Abl-Caveolin-1 signaling pathway

Steroid-induced avascular necrosis of the femoral head (SANFH) is a progressive degenerative disease of the hip, primarily due to glucocorticoid (GC)-induced endothelial cell (EC) injury and compromised blood supply. Irisin is an EC-protective mytokine whose receptor is the integrin αVβ5. Caveolin-1 (CAV-1)， a major component of caveolae, causes endothelial dysfunction when phosphorylated. However, the role of irisin and CAV-1 in SANFH remains unclear. In our study, irisin levels decreased but CAV-1 phosphorylation increased in human and mouse SANFH samples. Intraperitoneal irisin injection (250 μg/kg daily) notably reduced GC-induced osteonecrosis, vascular abnormalities, and CAV-1 phosphorylation in SANFH mice. In cultured ECs, GC induced CAV-1 phosphorylation by activating c-Abl via the glucocorticoid receptor, and irisin inhibited GC-induced phosphorylation of c-Abl and CAV-1 via the integrin αVβ5. Inhibition of integrin αVβ5 also abolished the protective effects of irisin on ERK and eNOS signalling, viability, angiogenesis, and migration in ECs. Therefore, our findings indicate that irisin has a protective role against vascular dysfunction in SANFH, possibly mediated by the inhibition of GC-triggered c-Abl-CAV-1 phosphorylation through integrin αVβ5. These findings provide insights into the potential therapeutic applications of irisin in SANFH.

Fatty Acylcarnitine Metabolism in Brown/Beige and White Fats by 13C HRMAS NMR Spectroscopy With Metabolic Interventions

White adipose tissue (WAT) and brown adipose tissue (BAT) have distinct structural and physiological characteristics and serve opposing functions in the body. WAT primarily stores energy, whereas BAT is metabolically active and positively influences metabolic health, contributing to energy expenditure, reduced fat accumulation and enhanced mitochondrial metabolism. Recently, both classical BAT and beige fat (or inducible/recruitable BAT) that arises from the browning of WAT have attracted clinical interest as potential targets for improving mitochondrial metabolism and managing obesity-related metabolic disorders. Currently, there is a lack of specific metabolic biomarkers for characterizing classical BAT and beige fat tissues, which are essential for evaluating mitochondrial oxidative metabolism and screening browning agents for therapeutic use. In this study, we investigated the potential metabolic biomarker fatty acylcarnitine in interscapular BAT (iBAT) from the interscapular region and beige adipose tissue from the inguinal region of the animal using ex vivo 13C high-resolution magic angle spinning (HRMAS) NMR spectroscopy. We examined how mitochondrial oxidative metabolism was altered in response to a high-fat diet (HFD) and how it was restored through iBAT activation using stimuli such as cold exposure and β3-adrenergic receptor (β3-AR) agonist, CL-316,243 treatment. We identified fatty acylcarnitine as a potential metabolic marker present in iBAT and beige tissues, whereas it was absent in iWAT. The concentration of fatty acylcarnitine significantly decreased in HFD-fed animals due to impaired lipolysis resulting in inefficient shuttling of fatty acids for mitochondrial β oxidation. However, its concentration increased or was restored in response to iBAT activation through either β3-AR agonist treatment or cold exposure, indicating a high-energy metabolic state with enhanced mitochondrial metabolism in iBAT. Fatty acylcarnitine shows promise as a biomarker for evaluating mitochondrial metabolism and for screening potential browning agents and nutraceuticals capable of inducing the browning of WAT.

Potential role of tanycyte-derived neurogenesis in Alzheimer's disease

Tanycytes, specialized ependymal cells located in the hypothalamus, play a crucial role in the generation of new neurons that contribute to the neural circuits responsible for regulating the systemic energy balance. The precise coordination of the gene networks controlling neurogenesis in naive and mature tanycytes is essential for maintaining homeostasis in adulthood. However, our understanding of the molecular mechanisms and signaling pathways that govern the proliferation and differentiation of tanycytes into neurons remains limited. This article aims to review the recent advancements in research into the mechanisms and functions of tanycyte-derived neurogenesis. Studies employing lineage-tracing techniques have revealed that the neurogenesis specifically originating from tanycytes in the hypothalamus has a compensatory role in neuronal loss and helps maintain energy homeostasis during metabolic diseases. Intriguingly, metabolic disorders are considered early biomarkers of Alzheimer's disease. Furthermore, the neurogenic potential of tanycytes and the state of newborn neurons derived from tanycytes heavily depend on the maintenance of mild microenvironments, which may be disrupted in Alzheimer's disease due to the impaired blood-brain barrier function. However, the specific alterations and regulatory mechanisms governing tanycyte-derived neurogenesis in Alzheimer's disease remain unclear. Accumulating evidence suggests that tanycyte-derived neurogenesis might be impaired in Alzheimer's disease, exacerbating neurodegeneration. Confirming this hypothesis, however, poses a challenge because of the lack of long-term tracing and nucleus-specific analyses of newborn neurons in the hypothalamus of patients with Alzheimer's disease. Further research into the molecular mechanisms underlying tanycyte-derived neurogenesis holds promise for identifying small molecules capable of restoring tanycyte proliferation in neurodegenerative diseases. This line of investigation could provide valuable insights into potential therapeutic strategies for Alzheimer's disease and related conditions.

Adipose-targeted nanohybrid as a browning inducer for synergistic hyperthermia-pharmacotherapy of obesity

Inducing adipose browning to increase energy expenditure has recently emerged as a promising approach for antiobesity treatment. However, its therapeutic efficacy is often limited by poor adipose-targeted drug delivery and suboptimal browning efficiency. To address these challenges, an adipose-targeting aptamer (Apt8) and browning agent resveratrol (Res) were used to construct an Apt-modified and Res-loaded degradable mesoporous silica-coated Au nanorods nanocarriers (NC), termed Res@NC@Apt8, achieving adipose-targeted hyperthermia-pharmacotherapy. Upon internalization by adipocytes, laser irradiation induces mild local hyperthermia (LHT) via Res@NC@Apt8, triggering calcium ion (Ca2+) influx. Simultaneously, the interaction of the nanohybrid with local glutathione (GSH) releases Res. The dual mechanisms activate the adenosine 5'-monophosphate-activated protein kinase (AMPK) pathway, reduce the lipid droplet content, enhance mitochondrial biogenesis, and accelerate metabolism, thereby synergistically promoting adipose browning. Intravenous Res@NC@Apt8 administration in obese mice significantly drives adipose reduction and further achieves excellent antiobesity therapeutic efficacy. This synergistic treatment achieves a superior weight reduction of 17.2% compared with 6.9% and 10.6% achieved using LHT and pharmacotherapy alone, respectively. This study introduces a novel strategy for achieving activatable LHT and drug release for synergetic obesity treatment.

Irisin prevents visceral hypersensitivity and colonic hyperpermeability in a rat model of irritable bowel syndrome

Visceral hypersensitivity and impaired gut barrier function, accompanied by minor inflammation, are crucial components of the pathophysiology of irritable bowel syndrome (IBS). Research has demonstrated that corticotropin-releasing factor (CRF) and toll-like receptor 4 (TLR4) signaling mutually activate to produce proinflammatory cytokines, which modulate these gastrointestinal changes. Irisin, a myokine, has been shown to inhibit TLR4-proinflammatory cytokine signaling, thereby improving inflammation driven by obesity and metabolic syndrome. Based on this, we hypothesized that irisin could improve visceral hypersensitivity and impaired gut barrier function induced by lipopolysaccharide (LPS) or CRF (IBS rat models), and tested this hypothesis. The visceral pain threshold, triggered by colonic balloon distention, was assessed by electrophysiologically monitoring abdominal muscle contractions in male Sprague-Dawley rats. Colonic permeability was evaluated by measuring the amount of Evans blue dye absorbed within the colonic tissue. Intraperitoneal irisin prevented LPS-induced visceral hypersensitivity and colonic hyperpermeability in a dose-dependent manner. Irisin also prevented CRF-induced gastrointestinal alterations. The beneficial effects of irisin in the LPS model were reversed by compound C, an AMP-activated protein kinase (AMPK) inhibitor; NG-nitro-L-arginine methyl ester, a nitric oxide (NO) synthesis inhibitor; sulpiride or domperidone, a dopamine D2 receptor antagonist; atropine and intracisternal injection of SB-334867, a selective orexin 1 receptor antagonist. Overall, these findings suggest that irisin improves visceral sensation and colonic barrier function through AMPK, NO and dopamine D2, cholinergic and brain orexin signaling in IBS model. Thus, irisin may be a promising therapeutic agent for treating IBS.

Therapeutic potential of exercise-hormone irisin in Alzheimer's disease

Irisin is a myokine that is generated by cleavage of the membrane protein fibronectin type III domain-containing protein 5 (FNDC5) in response to physical exercise. Studies reveal that irisin/FNDC5 has neuroprotective functions against Alzheimer's disease, the most common form of dementia in the elderly, by improving cognitive function and reducing amyloid-β and tau pathologies as well as neuroinflammation in cell culture or animal models of Alzheimer's disease. Although current and ongoing studies on irisin/FNDC5 show promising results, further mechanistic studies are required to clarify its potential as a meaningful therapeutic target for alleviating Alzheimer's disease. We recently found that irisin treatment reduces amyloid-β pathology by increasing the activity/levels of amyloid-β-degrading enzyme neprilysin secreted from astrocytes. Herein, we present an overview of irisin/FNDC5's protective roles and mechanisms against Alzheimer's disease.

Proteomics reveals genetic mechanisms of cold resistance in Hezuo pig liver tissue

Cold stress poses a significant challenge to pig farming in northern China, leading to reduced productivity and, in severe cases, even mortality. However, the mechanisms underlying cold resistance in pigs are not well understood. To explore the genetic mechanism of cold resistance in pigs under low-temperature conditions, the cold-tolerant Hezuo pig was selected as a model. DIA proteomics analysis was performed on liver tissues from Hezuo pigs after 24 h of exposure to low-temperature treatments. The results showed that approximately 149 differential abundance proteins (DAPs) were detected (95 up-regulated and 54 down-regulated). GO analysis showed that these DAPs were mainly associated with lipid metabolism, vesicle fusion, and membrane function. KEGG analysis showed that these DAPs were primarily enriched in lipid metabolism-related pathways such as cholesterol metabolism and vitamin digestion and absorption. Comprehensive analysis identified APOA4, APOA2, SREBF2, ATP23, STX2, USO1, ETFA, RAB11FIP1, ETNPPL, and SGMS1 as potential key proteins involved in cold resistance mechanisms. The mRNA expression of the genes for two key candidate proteins (APOA4 and SREBF2), which are involved in lipid metabolism, was analyzed using qRT-PCR, revealing a significant up-regulation after low-temperature treatment. These findings provide significant insights into the mechanisms of cold resistance in animals and may serve as candidate markers for further studies on cold tolerance. SIGNIFICANCE: Cold resistance is one of the key traits in pigs and involves multiple complex coordinated regulatory mechanisms. However, its genetic mechanisms are not completely understood. In this study, a DIA proteomics approach was used to identify proteins and pathways associated with cold resistance in the liver of low-temperature-treated Hezuo pigs. These findings offer novel candidate proteins and key pathways for investigating the molecular mechanisms of cold resistance in Hezuo pigs, providing a base for further elucidating the mechanisms of cold tolerance in pigs.

Potentials of peroxisome proliferator-activated receptor (PPAR) α, β/δ, and γ: An in-depth and comprehensive review of their molecular mechanisms, cellular Signalling, immune responses and therapeutic implications in multiple diseases

Peroxisome proliferator-activated receptors (PPARs), ligand-activated transcription factors, have emerged as a key regulator of various biological processes, underscoring their relevance in the pathophysiology and treatment of numerous diseases. PPARs are primarily recognized for their critical role in lipid and glucose metabolism, which underpins their therapeutic applications in managing type 2 diabetes mellitus. Beyond metabolic disorders, they have gained attention for their involvement in immune modulation, making them potential targets for autoimmune-related inflammatory diseases. Furthermore, PPAR's ability to regulate proliferation, differentiation, and apoptosis has positioned them as promising candidates in oncology. Their anti-inflammatory and anti-fibrotic properties further highlight their potential in dermatological and cardiovascular conditions, where dysregulated inflammatory responses contribute to disease progression. Recent advancements have elucidated the molecular mechanisms of different PPAR isoforms, including their regulation of key signalling pathways such as NF-κB and MAPK, which are crucial in inflammation and cellular stress responses. Additionally, their interactions with co-factors and post-translational modifications further diversify their functional roles. The therapeutic potential of various PPAR agonists has been extensively explored, although challenges related to side effects and target specificity remain. This growing body of evidence underscores the significance of PPARs in understanding the molecular basis of diseases and advancing therapeutic interventions, paving way for targeted treatment approach across a wide spectrum of medical conditions. Here, we provide a comprehensive and detailed perspective of PPARs and their potential across different health conditions to advance our understanding, elucidate underlying mechanisms, and facilitate the development of potential treatment strategies.

Obesity prevention by different exercise protocols (HIIT or MICT) involves beige adipocyte recruitment and improved mitochondrial dynamics in high-fat-fed mice

AIM

This study evaluated the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on UCP1-dependent and UCP1-independent thermogenic and mitochondrial dynamics markers in the inguinal sWAT of high-fat-fed mice.

METHODS

Sixty male C57BL/6 mice (3 months old) were divided into six experimental groups: control diet (C), C + HIIT (C-HIIT), C + MICT (C-MICT), high-fat diet (HF), HF + HIIT (HF-HIIT) and HF + MICT (HF-MICT). The diet and exercise protocols started simultaneously and lasted ten weeks.

RESULTS

HIIT and MICT prevented body mass gain and fat pad expansion, improved insulin sensitivity, and induced browning in C-fed and HF-fed animals. Chronic intake of a HF diet caused adipocyte hypertrophy with a proinflammatory adipokine profile and impaired the expression of thermogenic and mitochondrial dynamics markers. However, both exercise intensities increased anti-inflammatory adipokine concentrations and improved gene markers of mitochondrial dynamics, resulting in sustained UCP1-dependent and UCP1-independent thermogenic markers and maintenance of the beige phenotype in inguinal sWAT. The principal component analysis placed all trained groups opposite the HF group and near the C group, ensuring the effectiveness of HIIT and MICT to prevent metabolic alterations.

CONCLUSIONS

This study provides reliable evidence that, regardless of intensity, exercise is a strategy to prevent obesity by reducing body fat accumulation and inducing browning. The anti-inflammatory adipokine profile and the increased expression of UCP1-dependent and UCP1-independent thermogenic markers sustained active beige adipocytes and mitochondrial enhancement to halt metabolic disturbances due to HF-feeding in exercised mice.

Distinct signalling dynamics of BMP4 and BMP9 in brown versus white adipocytes

Adipocyte dysfunction contributes to lipotoxicity and cardiometabolic diseases. Bone morphogenetic protein 4 (BMP4) is expressed in white adipocytes and remodels white adipose tissue, while liver-derived BMP9, a key circulating BMP, influences adipocyte lipid metabolism. The gene sets regulated by BMP4 and BMP9 signalling in mature adipocytes remain unclear. Here, we directly compare BMP4 and BMP9 signalling in mature brown and white adipocytes. While both BMPs showed comparable potency across adipocyte types, RNA sequencing analysis revealed extensive gene regulation, with many more differentially expressed genes and suppression of critical metabolic pathways in white adipocytes. Although BMP4 and BMP9 induced inhibitors of BMP and GDF signalling in both adipocytes, they selectively upregulated several TGF-β family receptors and BMP4 expression only in white adipocytes. These findings underscore a central role of BMP signalling in adipocyte homeostasis and suggest both BMP4 and BMP9 as regulators of white adipocyte plasticity with potential therapeutic implications.

Exercise-Stimulated Resolvin Biosynthesis in the Adipose Tissue Is Abrogated by High-Fat Diet-Induced Adrenergic Deficiency

BACKGROUND

Diet-induced white adipose tissue inflammation is associated with insulin resistance and metabolic perturbations. Conversely, exercise protects against the development of diet-induced chronic inflammation and insulin resistance independent of weight loss; however, the mechanisms remain largely unknown. We have recently shown that through adrenergic stimulation of macrophages, exercise promotes resolution of acute peritoneal inflammation by enhancing the biosynthesis of specialized proresolving lipid mediators. In this study, we sought to determine whether exercise stimulates proresolving pathways in adipose tissue and whether this response is modified by diet. Specifically, we hypothesized that exercise stimulates proresolving pathways by adrenergic signaling, which is inhibited by high-fat diet, priming the development of chronic inflammation in the adipose tissue.

METHODS

To explore the dietary dependence of the proresolving effects of exercise, mice were fed either a control or high-fat diet for 2 weeks before, and throughout, a 4-week period of daily treadmill running. Glucose handling, body weight and composition, lipemia, and exercise performance were evaluated at the end of the feeding and exercise interventions. Likewise, changes in catecholamines and their biosynthetic enzymes were measured along with adipose tissue specialized proresolving lipid mediator levels and macrophage phenotype and abundance.

RESULTS

When compared with sedentary controls, macrophages isolated from mice exposed to 4 weeks of exercise display elevated expression of the specialized proresolving lipid mediator biosynthetic enzyme Alox15, while adipose tissue specialized proresolving lipid mediator levels and anti-inflammatory CD301+ M2 macrophages increased. These changes were dependent upon diet as 6 weeks of feeding with high-fat diet abrogated the proresolving effect of exercise when compared with control diet-fed animals. Interestingly, exercise-induced epinephrine production was inhibited by high-fat diet, which diminished the expression of the epinephrine biosynthetic enzyme PNMT (phenylethanolamine N-methyltransferase) in adrenal glands.

CONCLUSIONS

Taken together, these results suggest that a diet high in fat diminishes the proresolving effects of exercise in the adipose tissue via decreasing the biosynthesis of catecholamines.

Study on the comorbid mechanisms of sarcopenia and late-life depression

The increasing global aging population has brought greater focus to age-related diseases, particularly muscle-brain comorbidities such as sarcopenia and late-life depression. Sarcopenia, defined by the gradual loss of muscle mass and function, is notably prevalent among older individuals, while late-life depression profoundly affects their mental health and overall well-being. Epidemiological evidence suggests a high co-occurrence of these two conditions, although the precise biological mechanisms linking them remain inadequately understood. This review synthesizes the existing body of literature on sarcopenia and late-life depression, examining their definitions, prevalence, clinical presentations, and available treatments. The goal is to clarify the potential connections between these comorbidities and offer a theoretical framework for the development of future preventive and therapeutic strategies.

Mechanisms through which laparoscopic sleeve gastrectomy mitigates atherosclerosis risk: a focus on visceral adipose tissue

Bariatric surgery is currently considered the key treatment method for patients with obesity and related complications. Among the various surgeries, laparoscopic sleeve gastrectomy (LSG) is the most widely used. Obesity is a multifactor chronic disease characterized by the accumulation of visceral adipose tissue (VAT), leading to susceptibility to cardiac metabolic diseases. Many mechanisms, including abnormal lipid metabolism, insulin resistance, inflammation, endothelial dysfunction, adipocytokine imbalance and inflammasome activation, have been identified as the basis for the relationship between obesity and atherosclerosis. Bariatric surgery, such as LSG, reduces the risk of atherosclerosis in people living with obesity by reducing energy intake, disrupting energy balance and reducing the secretion of intestinal hormones to intervene in these risk factors. This review explores the current understanding of how LSG affects VAT and its impact on the risk of atherosclerosis.

Nuclear IL-1α Triggers Pyroptosis in Porcine Intramuscular Preadipocytes

Pigs are vital for meat production, and their intramuscular fat content significantly impacts pork quality and flavor. Using single-cell RNA sequencing (scRNA-seq) on porcine intramuscular fat, we found that adipose progenitor cells express highly inflammatory genes, including IL-1α, during adipogenic differentiation. IL-1α, a pro-inflammatory cytokine present in various cell types, can translocate to the nucleus via its nuclear localization sequence (NLS), yet its nuclear function remains unclear. By constructing an inactivated NLS carrier for IL-1α, we discovered that nuclear IL-1α promotes pyroptosis in porcine intramuscular adipocytes through the IRF2-NOCT-ROS pathway. This study reveals a novel role of nuclear IL-1α in pyroptosis regulation, providing insights into enhancing the intramuscular fat content and improving pork quality.

Ceramide-induced FGF13 impairs systemic metabolic health

Ceramide accumulation impairs adipocytes' ability to efficiently store and utilize nutrients, leading to energy and glucose homeostasis deterioration. Using a comparative transcriptomic screen, we identified the non-canonical, non-secreted fibroblast growth factor FGF13 as a ceramide-regulated factor that impairs adipocyte function. Obesity robustly induces FGF13 expression in adipose tissue in mice and humans and is positively associated with glycemic indices of type 2 diabetes. Pharmacological or genetic inhibition of ceramide biosynthesis reduces FGF13 expression. Using mice with loss and gain of function of FGF13, we demonstrate that FGF13 is both necessary and sufficient to impair energy and glucose homeostasis independent of ceramides. Mechanistically, FGF13 exerts these effects by inhibiting mitochondrial content and function, metabolic elasticity, and caveolae formation, which cumulatively impairs glucose utilization and thermogenesis. These studies suggest the therapeutic potential of targeting FGF13 to prevent and treat metabolic diseases.

Brain donation rules in Italy and worldwide: overview of a cutting-edge topic for human brain research

Neuropathological examination of the brain and its biochemical analyses are fundamental to neuroscience studies and public health decisions, but are dependent on the effectiveness of regulations and operational protocols. The article discusses opportunities and limits of Italian regulation on body donation in relation to the specific requirements of neuropathology and brain sciences, in comparison with the regulations of other countries. Some crucial issues emerge, widely shared in the various regulatory contexts. The main aspect is the willingness to donate, consciously expressed by the subject by signing an informed consent or through the formulation of advanced directives. The donation of a single organ, the brain in particular, does not necessarily imply the donation of the entire body, which should be considered separately. In the specific case of the brain, particular attention is given to reducing the post-mortem interval, in order to obtain tissues suitable for research. Consequently, the centres that deal with the brain and brain banking must have experience and expertise in handling nervous tissue, and do not necessarily have to deal with the management of the entire body. These aspects, still little addressed in Italy, are the basis to develop an effective brain banking activity, which can only develop by integrating post-mortem body donation with specific rules for brain banking without which Italian neuroscience will be penalised in the coming years.

Calf circumference predicts changes of bone mineral density in postmenopausal osteoporotic women receiving denosumab

BACKGROUND

Aging is associated with deterioration of muscle and bone health, resulting in increased fragility fracture risk. It is not known whether muscle mass and strength could impact the osteoporosis pharmacological response.

AIM

The aim of this study was to analyze the association between muscle mass and strength with the response to denosumab in osteoporosis.

METHODS

Postmenopausal women at high fracture risk receiving denosumab (60 mg subcutaneously administered every 6 months) were considered. The likelihood of sarcopenia was estimated by administering the SARC-F questionnaire, muscle mass and performance were assessed by measuring calf circumference (CC) and hand grip strength, respectively. Bone mineral density (BMD) was measured by dual energy X-ray absorptiometry.

RESULTS

130 women (age 70.2 ± 9.4 years) were recruited. Baseline BMD T-score values were - 2.6 ± 1.1 SD and - 2.3 ± 0.7 SD at lumbar spine and femoral neck, respectively; while CC and grip strength were 31.9 ± 2.9 cm and 22.7 ± 6.7 kg, respectively. The SARC-F score was associated with the 10-year probability of major osteoporotic fracture (r = 0.21, p < 0.05). The CC was positively associated with the T-score values of both lumbar spine (r = 0.262, p = 0.034) and femoral neck (r = 0.359, p = 0.004). Denosumab administration (treatment duration 43 months), lead to BMD improvement by + 9.6% at the lumbar spine and + 7.3% at the femoral neck (pall < 0.05). After adjustment for comorbidities, fracture risk and treatment duration, the CC (β = 1.76, SE = 0.82, p = 0.03) and the baseline femoral BMD (β = - 94.19, SE = 26.09, p = 0.0009) were independently associated with femoral BMD gain over time.

CONCLUSION

In postmenopausal osteoporotic women, the CC was positively and independently associated with denosumab treatment response.

Are breast milk and serum irisin levels affected by the BMI and nutritional status? A prospective observational study

The influence of maternal nutritional status and anthropometric measurements on breast milk and serum irisin levels remains unclear. This study is the first to explore this relationship. This study aims to investigate the association between maternal BMI and nutritional status in the first month postpartum and their impact on breast milk and serum irisin levels. Forty-five mothers and their infants participated. Anthropometric measurements were taken at one month postpartum, maternal dietary intake was recorded over three days, and breast milk and serum irisin levels were analyzed. Overweight and obese mothers had lower breast milk irisin levels but higher serum irisin levels. A positive correlation was observed between breast milk irisin levels and infant birth weight. Additionally, serum irisin levels were positively associated with infant weight and height at one month. Maternal fiber intake was positively correlated with breast milk irisin levels, whereas fat intake showed a negative correlation. Moreover, higher folate, B12, and zinc intake were linked to increased breast milk and serum irisin levels.

CONCLUSION

Maternal BMI and nutritional status significantly influence breast milk and serum irisin levels. Promoting healthy eating habits and maintaining an optimal body weight before and after pregnancy may enhance irisin levels, potentially supporting infant growth and metabolic health.

WHAT IS KNOWN

• Irisin is a myokine involved in energy metabolism and insulin sensitivity, and breast milk composition is influenced by maternal BMI and nutritional status. • The effect of maternal obesity on breast milk irisin levels remains insufficiently understood.

WHAT IS NEW

• This is the first study to evaluate the association between maternal BMI, nutritional status, and both breast milk and serum irisin levels. • Overweight and obese mothers exhibit lower breast milk irisin but higher serum irisin levels, and maternal intake of fiber, fat, folate, vitamin B12, and zinc is significantly associated with irisin levels.

TBC1D15 protects alcohol-induced liver injury in female mice through PLIN5-mediated mitochondrial and lipid droplet contacting

OBJECTIVE

Alcohol-induced hepatic steatosis and mitochondrial dysfunction are progressive conditions contributing to the development of alcoholic liver disease (ALD), often leading to cirrhosis and hepatocellular carcinoma. TBC1D15, a Rab7 GTPase-activating protein (GAP), has been implicated in mitochondrial homeostasis, however, its role in ALD remains elusive. This study aimed to investigate the functional role of TBC1D15 in ALD and elucidate the underlying mechanisms.

METHODS

Female TBC1D15flox/flox mice and hepatocyte-specific overexpression of TBC1D15 mice were fed a Lieber-DeCarli ethanol diet, which progressively increasing ethanol dosages over 8 weeks. Liver tissues were assessed using histology, transmission electron microscopy, immunofluorescence, immunoblotting, and real-time PCR techniques.

RESULTS

TBC1D15 levels were markedly decreased in human ALD samples and primary hepatocytes exposed to ethanol. Hepatocyte-specific TBC1D15 overexpression attenuated alcohol-induced body weight loss, improved survival, and alleviated liver injury, lipid droplet (LD) accumulation, and hepatocyte apoptosis. TBC1D15 overexpression also protected against alcohol-induced mitochondrial dysfunction and enhanced mitochondrial fatty acid β-oxidation (FAO) by promoting interactions between mitochondria and LDs in the face of alcohol exposure. Mechanistically, TBC1D15 was translocated to mitochondrial membranes in hepatocytes in response to alcohol exposure, where it recruited PLIN5 through its 10-180 aa domain. This interaction promoted mitochondria-LD contacts and facilitated PKA-induced nuclear translocation of PLIN5. Furthermore, TBC1D15 upregulated protein levels of PPARα, PGC1α and CPT1α in hepatocytes following alcohol challenge, an effect that was nullified by PKA inhibition.

CONCLUSION

TBC1D15 plays a promising protective role in ALD injury by enhancing mitochondrial function and FAO, potentially through its interaction with PLIN5 and modulation of mitochondria-LD contacts via PKA-mediated nuclear translocation of PLIN5. These findings identify TBC1D15 as a potential therapeutic target for ALD.

Irisin suppressed the progression of TBI via modulating AMPK/MerTK/autophagy and SYK/ROS/inflammatory signaling

Irisin is a hormone-like peptide secreted by muscle tissues and generated by hydrolysis of type III fibronectin domain-containing protein 5 by proteolytic hydrolases. Whether Irisin has a potential protective role in traumatic brain injury (TBI). In this study, we will investigate the relevant research progress of Irisin's protective role in traumatic brain injury (TBI) in recent years in terms of attenuating oxidative stress, inhibiting pyroptosis, suppressing inflammatory response, and improving autophagy, with the aim of providing valuable references for the diagnosis and treatment of traumatic brain injury (TBI). Utilize bioinformatics analysis to study the interactions between genes in TBI (Traumatic Brain Injury). Construct a TBI mouse model to observe the effects of Irisin on TBI. The Morris water maze test is used to assess the learning and spatial memory abilities of mice, TUNEL fluorescence is used to detect cell apoptosis, Nissl staining is employed to observe the survival of hippocampal neurons in mice, and HE staining is used to observe the extent of brain injury in mice. Western blot is used to detect protein expression in both in vivo and in vitro experiments. Q-PCR is employed to detect the levels of proteins related to autophagy/pyroptosis/inflammation. Irisin promotes MerTK overexpression by enhancing AMPK activation. Irisin can increase the expression of LC3I and Beclin-1 proteins, indicating the promotion of autophagic response. Additionally, Irisin reduces ROS levels and decreases SYK expression, thereby inhibiting the inflammatory response. Irisin improves the learning and spatial memory abilities of TBI mice and reduces cell apoptosis, as well as decreases hippocampal neuron death. HE staining shows that the brain injury in mice treated with Irisin is significantly alleviated. Irisin can enhance the expression of phosphorylated AMPK and phosphorylated MerTK proteins, promote autophagic response, and inhibit pyroptosis/inflammatory response. Correction experiments confirmed that after stimulation with an AMPK agonist, the expression of phosphorylated MerTK protein is significantly increased, autophagic response is enhanced, and pyroptosis/inflammatory response is weakened. When treated with a MerTK inhibitor during AMPK agonist stimulation, the autophagic response is weakened while pyroptosis/inflammatory response is enhanced. Irisin can inhibit the progression of traumatic brain injury by regulating AMPK/MerTK/autophagy and SYK/ROS/inflammatory signaling.

Single-cell transcriptomics reveals extracellular matrix remodeling and collagen dynamics during lactation in sheep mammary gland

The mammary gland is a dynamic organ with diverse cell populations that maintain glandular homeostasis, particularly during lactation. However, the cellular architecture and molecular mechanisms underlying lactational remodeling in the sheep mammary gland remain incompletely understood. Given similarities in mammary stromal structure, sheep serve as a valuable model for studying lactational changes relevant to the human breast, which experiences collagen loss and sagging during lactation. Utilizing single-cell transcriptomics (scRNA-seq), we mapped the sheep mammary gland's cellular landscape at postpartum days 60 and 150, identifying seven major cell types, including six distinct epithelial clusters. These clusters revealed differentiation among luminal progenitors, hormone-sensing, and myoepithelial cells across peak and late lactation stages. Transcriptomic analysis highlighted pivotal roles for epithelial integrity and ECM remodeling, with myoepithelial cells centrally involved in these processes. We observed significant collagen remodeling driven by fibroblast-epithelial crosstalk and ECM reorganization during late lactation. Comparative analysis with human mammary epithelial cells showed conserved basal and myoepithelial cell populations, while luminal cells diverged across species. This study provides insights into lactation biology and ECM remodeling, offering a framework to inform future studies on lactational adaptation and its implications for human health.

Spot-14 and its paralog Spot-14R regulate expression of metabolic and thermogenic pathway genes in murine brown and beige adipocytes

Spot 14 (S14), encoded by Thrsp, is a thyroid hormone-responsive transcriptional activator that regulates lipogenesis, though its mechanisms remain unclear. We aimed to study the role of S14 on gene expression in adipocytes. We analyzed Thrsp and its paralog Mid1ip1 in brown (EB5), beige (EB7), and white (F442A) adipocytes. Thrsp expression was higher in EB5 and EB7 than in F442A and increased with thyroid hormone T3 in EB5 and EB7 but decreased in F442A. Mid1ip1 expression rose moderately in EB5 and EB7, influencing lipid metabolism genes. Silencing Thrsp upregulated Mid1ip1 in EB7 and reduced thermogenic gene expression in EB5 and EB7. These findings underscore the roles of Thrsp and Mid1ip1 in metabolic and thermogenic pathways, highlighting the responsiveness of S14 to thyroid hormones and nutrient signals. Impact statement This study reveals that Thyroid Hormone-Induced Protein 8 (THRSP), also known as Spot-14, and its paralog Spot-14R, regulate metabolic and thermogenic gene expression differently in brown and beige adipocytes. These findings provide insights into adipocyte metabolism, offering potential targets for obesity and metabolic disorder treatments.

Sestrin2 is a central regulator of mitochondrial stress responses in disease and aging

Mitochondria supply most of the energy for cellular functions and coordinate numerous cellular pathways. Their dynamic nature allows them to adjust to stress and cellular metabolic demands, thus ensuring the preservation of cellular homeostasis. Loss of normal mitochondrial function compromises cell survival and has been implicated in the development of many diseases and in aging. Although exposure to continuous or severe stress has adverse effects on cells, mild mitochondrial stress enhances mitochondrial function and potentially extends health span through mitochondrial adaptive responses. Over the past few decades, sestrin2 (SESN2) has emerged as a pivotal regulator of stress responses. For instance, SESN2 responds to genotoxic, oxidative, and metabolic stress, promoting cellular defense against stress-associated damage. Here, we focus on recent findings that establish SESN2 as an orchestrator of mitochondrial stress adaptation, which is supported by its involvement in the integrated stress response, mitochondrial biogenesis, and mitophagy. Additionally, we discuss the integral role of SESN2 in mediating the health benefits of exercise as well as its impact on skeletal muscle, liver and heart injury, and aging.

TREM2 as a regulator of obesity-induced cardiac remodeling: mechanisms and therapeutic insights

Obesity and type 2 diabetes mellitus (T2DM) are global health challenges that significantly increase the risk of cardiovascular diseases (CVD). Advances in immunometabolism have identified triggering receptor expressed on myeloid cells 2 (TREM2) as a key regulator of macrophage function, lipid metabolism, and inflammation resolution. Although extensively studied in neurodegenerative diseases, TREM2's role in metabolic disorders and cardiovascular health is an emerging area of research. This review explores TREM2's molecular structure and functions, emphasizing its contributions to immunometabolic regulation in obesity and T2DM. Evidence from preclinical models demonstrates that TREM2 modulates macrophage-driven inflammatory responses, lipid clearance, plaque stability, fibrosis, and myocardial remodeling. Translational findings suggest that TREM2 expression correlates with cardiometabolic outcomes, underscoring its potential as a therapeutic target. Key knowledge gaps include TREM2's temporal dynamics during disease progression, sex-specific effects, and interactions with recruited or resident macrophage activation in obesity and T2DM. Integrating mechanistic and translational insights is critical to harness TREM2's immunoregulatory potential for improving CVD outcomes in metabolic disorders.

Dental outcomes after gastric bypass and sleeve gastrectomy: a register-based study

BACKGROUND

Bariatric surgery has been shown to cause a negative impact on oral health, as reflected by postsurgical increase of caries-related dental interventions.

OBJECTIVES

The aim of this study was to compare dental intervention rates after Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG).

SETTING

Nationwide and register-based (Sweden).

METHODS

This 2-staged matched cohort study included all adults who underwent RYGB (n = 26,594) or SG (n = 3416) between 2011 and 2015, registered in the Scandinavian Obesity Surgery Register. Propensity score matching was used to match SG patients to RYGB patients, based on several covariates. The follow-up time was 3 years after surgery. The dental variables were collected from the Dental Health Register, including tooth extractions, restorative interventions (dental fillings), and endodontic interventions (root canal treatment).

RESULTS

In total, 3317 RYGB and 3317 SG patients were included. Both groups showed increased dental event rates postoperatively. RYGB patients had significantly higher event rates compared with SG postoperatively regarding all interventions, restorative and endodontic interventions.

CONCLUSIONS

The negative effect on dental outcomes in terms of dental fillings and tooth extractions were higher after RYGB than after SG. The reasons are not clear. More research is needed to replicate these findings, to understand the mechanisms, and further delineate the significance of the surgical method.

Activation of Gut Microbiota-HIF1α Axis Effectively Restores Resistance to Aeromonas veronii Caused by Improper Administration of AiiO-AIO6

BACKGROUND

Feeding adult zebrafish a diet supplemented with quenching enzyme AiiO-AIO6 (AIO6) for 3 wk improved the growth performance and disease resistance. However, when the feeding period was extended to 8 wk, zebrafish's disease resistance to Aeromonas veronii decreased.

OBJECTIVES

We investigated the mechanisms of the reduced disease resistance of zebrafish induced by feeding on an AIO6 supplemented diet for a long term (8 wk) and assessed the effectiveness of feed additives in restoring the low disease resistance.

METHODS

One-month-old (adult) zebrafish were fed with a basal diet and the basal diet supplemented with AIO6 (10 U/g) for 8 wk (experiment 1). Furthermore, the zebrafish larvae model (experiment 2) was developed and used to study the mechanisms of how AIO6 affected disease resistance (experiment 3). We also investigated the effectiveness of selected prebiotic tributyrin, β-glucan or mannan in activating gut microbiota- HIF1α to restore the low disease resistance of adult zebrafish fed with AIO6 for 8 wk (experiment 4). Lastly, the effects of Bacillus subtilis in activating the gut microbiota-HIF1α and improving the low disease resistance of zebrafish larvae induced by AIO6 were examined (experiment 5).

RESULTS

Feeding adult zebrafish with AIO6 for 8 wk promoted growth but disordered the gut microbiota and reduced disease resistance. The zebrafish larvae model confirmed that feeding AIO6 for 2 d increased disease resistance, whereas 7 d decreased the resistance by suppressing HIF1α. Using a germ-free zebrafish larvae model, we also demonstrated that AIO6-induced gut microbiota mediated inhibition of HIF1α. Furthermore, zebrafish fed on the AIO6-containing diet supplement with tributyrin, β-glucan, mannan, or Bacillus subtilis activated the gut microbiota-HIF1α axis to reverse the low resistance caused by AIO6.

CONCLUSIONS

Activating the gut microbiota-HIF1α axis has a vital role in improving intestinal health and restores the low resistance to Aeromonas veronii caused by improper administration of dietary AIO6 in zebrafish.

Natural products alleviate atrial fibrillation by modulating mitochondrial quality control

BACKGROUND

Atrial fibrillation (AF), one of the most common cardiac arrhythmias, is associated with high mortality rates and significant healthcare burdens. Mitochondrial homeostasis has recently emerged as a critical factor in AF pathogenesis but remains at the experimental stage. Current drug and surgical treatments for AF often involve side effects and require ongoing treatment plan evaluation and adjustment. In contrast, natural products (NPs), which have been utilized in China for over 2,000 years, show remarkable efficacy in treating AF and are receiving growing attention.

PURPOSE

We aimed to investigate the regulatory effects of NPs on mitochondrial quality control (MQC) and their impact on AF occurrence and progression. By constructing a novel NP-mitochondria-AF axis, we propose a framework to translate experimental findings into clinical practice and identify potential therapeutic strategies for AF.

METHODS

Databases such as PubMed, Web of Science, and China National Knowledge Infrastructure were searched (up to October 2024) using the following keywords: "atrial fibrillation," "traditional Chinese medicine," "mitochondrial biogenesis," "mitochondrial dynamics," "mitophagy," "apoptosis," "oxidative stress," "inflammation," and "Ca2+ concentration." NP targets were identified using the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform, while disease targets were retrieved from Online Mendelian Inheritance in Man, GeneCards, and Therapeutic Target Database. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was performed using the Metascape database. Protein-protein interactions were analyzed using the STRING database, and core monomers and hub genes were identified using Cytoscape 3.7.2.

RESULTS

We found a strong relationship between mitochondrial homeostasis and AF development. KEGG pathway analysis indicated that commonly used NPs regulate mitochondrial homeostasis, affecting AF progression through various hub genes, including protein kinase B-alpha (AKT1), jun proto-oncogene (JUN), and tumor necrosis factor (TNF). Molecular docking analysis revealed that NP core monomers exhibited binding affinities to hub genes below -5 kcal/mol and to transforming growth factor-β (TGF-β) below -7 kcal/mol.

CONCLUSION

NPs, including traditional Chinese medicine (TCM) compounds, TCM monomers, and traditional Chinese patent medicines, alleviate AF by modulating MQC with minimal side effects and high efficacy. These findings highlight the therapeutic potential of NPs as promising candidates for AF treatment and further underscore the importance of MQC in AF pathogenesis.

Metabolaging: a new geroscience perspective linking aging pathologies and metabolic dysfunction

With age, our metabolic systems undergo significant alterations, which can lead to a cascade of adverse effects that are implicated in both metabolic disorders, such as diabetes, and in the body's ability to respond to acute stress and trauma. To elucidate the metabolic imbalances arising from aging, we introduce the concept of "metabolaging." This framework encompasses the broad spectrum of metabolic disruptions associated with the hallmarks of aging, including the functional decline of key metabolically active organs, like the adipose tissue. By examining how these organs interact with essential nutrient-sensing pathways, "metabolaging" provides a more comprehensive view of the systemic metabolic imbalances that occur with age. This concept extends to understanding how age-related metabolic disturbances can influence the response to acute stressors, like burn injuries, highlighting the interplay between metabolic dysfunction and the ability to handle severe physiological challenges. Finally, we propose potential interventions that hold promise in mitigating the effects of metabolaging and its downstream consequences.

Alpha-aminobutyric acid administration suppressed visceral obesity and modulated hepatic oxidized PUFA metabolism via gut microbiota modulation

BACKGROUND

High-fat diet (HFD) is associated with visceral obesity due to disruption in the lipid metabolism and gut dysbiosis. These symptoms may contribute to hepatic steatosis and the formation of oxidized polyunsaturated fatty acids (PUFAs). Alpha-aminobutyric acid (ABA) is an amino-acid derived metabolite, and its concentration has been correlated with several metabolic conditions and gut microbiome diversity while its direct effects on visceral obesity, lipid metabolism and the gut microbiota are not well understood. This study was designed to investigate the effect of physiological dose of ABA on diet-induced visceral obesity and lipid metabolism dysregulation by examining the fatty acids and oxidized PUFAs profile in the liver as well as the gut microbiota.

RESULTS

ABA administration reduced visceral obesity by 28 % and lessened adipocyte hypertrophy. The expression of liver Cd36 was lowered by more than 50 % as well as the saturated and monounsaturated FA concentration. Notably, the desaturation index for C16 and C18 FAs that are correlated with adiposity were reduced. The concentration of several DHA-derived oxidized PUFAs were also enhanced. Faecal metagenomics sequencing revealed enriched abundance of Leptogranulimonas caecicola and Bacteroides sp. ZJ-18 and were positively correlated with several DHA- and ALA-derived oxidized PUFAs in ABA group.

CONCLUSION

Our study revealed the modulatory effect of physiological dose of ABA on attenuating visceral obesity, reducing hepatic steatosis, and promoting the production of anti-inflammatory oxidized PUFAs that were potentially mediated by the gut microbiota.

Regulation of the terminal complement cascade in adipose tissue for control of its volume, cellularity, and fibrosis

White adipose tissue (WAT) is a reservoir for various pathogens and their products, such as lipopolysaccharides. Therefore, it must be equipped with a defense mechanism connected with the activation of innate immunity. This explains the phenomenon that adipocytes express components of the classical and alternative complement pathways, which can be activated even in the absence of opportunistic pathogens. Terminal stages of the complement pathway are related to the production of membrane attack complexes and, thus, can cause lysis of pathogens, as well as autolysis of host adipocytes, contributing to the regulation of the cellularity in WAT. Complement-induced autolysis of adipocytes is counteracted by a number of cellular defense mechanisms. This versatility of activation and suppression processes enables a broad range of adaptability to physiological contexts, ranging from the development of hypertrophic WAT to lipodystrophy. Pathogen-induced activation of the complement pathway in WAT also induces a profibrotic phenotype. These processes may also be involved in the regulation of insulin resistance in adipocytes. This explains the dual immune/metabolic role of the complement pathway in WAT: the pathway is an integral part of the immune response but also potently involved in the control of volume and cellularity of WAT under both physiological and pathological conditions.

Enhancing adipose tissue plasticity: progenitor cell roles in metabolic health

Adipose tissue demonstrates considerable plasticity and heterogeneity, enabling metabolic, cellular and structural adaptations to environmental signals. This adaptability is key for maintaining metabolic homeostasis. Impaired adipose tissue plasticity can lead to abnormal adipose tissue responses to metabolic cues, which contributes to the development of cardiometabolic diseases. In chronic obesity, white adipose tissue undergoes pathological remodelling marked by adipocyte hypertrophy, chronic inflammation and fibrosis, which are linked to local and systemic insulin resistance. Research data suggest that the capacity for healthy or unhealthy white adipose tissue remodelling might depend on the intrinsic diversity of adipose progenitor cells (APCs), which sense and respond to metabolic cues. This Review highlights studies on APCs as key determinants of adipose tissue plasticity, discussing differences between subcutaneous and visceral adipose tissue depots during development, growth and obesity. Modulating APC functions could improve strategies for treating adipose tissue dysfunction and metabolic diseases in obesity.

Pyroptosis: A spoiler of peaceful coexistence between cells in degenerative bone and joint diseases

BACKGROUND

As people age, degenerative bone and joint diseases (DBJDs) become more prevalent. When middle-aged and elderly people are diagnosed with one or more disorders such as osteoporosis (OP), osteoarthritis (OA), and intervertebral disc degeneration (IVDD), it often signals the onset of prolonged pain and reduced functionality. Chronic inflammation has been identified as the underlying cause of various degenerative diseases, including DBJDs. Recently, excessive activation of pyroptosis, a form of programed cell death (PCD) mediated by inflammasomes, has emerged as a primary driver of harmful chronic inflammation. Consequently, pyroptosis has become a potential target for preventing and treating DBJDs.

AIM OF REVIEW

This review explored the physiological and pathological roles of the pyroptosis pathway in bone and joint development and its relation to DBJDs. Meanwhile, it elaborated the molecular mechanisms of pyroptosis within individual cell types in the bone marrow and joints, as well as the interplay among different cell types in the context of DBJDs. Furthermore, this review presented the latest compelling evidence supporting the idea of regulating the pyroptosis pathway for DBJDs treatment, and discussed the potential, limitations, and challenges of various therapeutic strategies involving pyroptosis regulation.

KEY SCIENTIFIC CONCEPTS OF REVIEW

In summary, an interesting identity for the unregulated pyroptosis pathway in the context of DBJDs was proposed in this review, which was undertaken as a spoiler of peaceful coexistence between cells in a degenerative environment. Over the extended course of DBJDs, pyroptosis pathway perpetuated its activity through crosstalk among pyroptosis cascades in different cell types, thus exacerbating the inflammatory environment throughout the entire bone marrow and joint degeneration environment. Correspondingly, pyroptosis regulation therapy emerged as a promising option for clinical treatment of DBJDs.

Therapeutic Effects of Different Ultrasound Intensity Stimulation on Brown Adipose Tissue for the Treatment of Type 2 Diabetes

Type 2 diabetes (T2D) is a persistent illness that has a high incidence rate. Still, there is no conclusive evidence on effectively improving blood sugar levels in patients through physical therapy. This study examined the regulatory effects of different intensities of low-intensity pulsed ultrasound (LIPUS) on T2D by stimulating brown adipose tissue (BAT). Eight-week-old C57BL/6J mice were divided into six groups (n = 10 per group): Control sham (C-Sham), Control-LIPUS (C-LIPUS), T2D-sham (T2D-Sham), T2D groups treated with LIPUS at spatial average-temporal-average intensity (Isata) of 60mW/cm² (T2D-L-60), 80mW/cm² (T2D-L-80), and 100mW/cm² (T2D-L-100). T2D models were induced by intraperitoneal injection of 40 mg/kg streptozotocin (STZ) three times after 12 wks of high-fat diet (HFD). The T2D-LIPUS group received LIPUS stimulation for 20 minutes per day for 6 weeks. The LIPUS stimulation had a duty cycle of 20%, a frequency of 1 MHz, and Isata of 60mW/cm², 80mW/cm², 100mW/cm². Subsequently, glucose tolerance tests (GTT) and insulin tolerance tests (ITT) were performed, and body fat content in mice was analyzed using nuclear magnetic resonance (NMR). Metabolic changes were monitored using metabolic cages. The results indicated that 80mW/cm² intensity level significantly improved glucose tolerance, insulin sensitivity, and metabolic function after LIPUS exposure. Significant reductions in body fat content and enhanced thermogenesis were observed, highlighting the potential of LIPUS in T2D management. This provides the basis for the dose study of LIPUS in the treatment of T2D.

Photoperiod influences visceral adiposity and the adipose molecular clock independent of temperature in wild-derived Peromyscus leucopus

Physiology is closely synchronized to daily and seasonal light/dark cycles. Humans artificially extend daylight and experience irregular light schedules, resulting in dysregulation of metabolism and body mass. In rodents, winter-like conditions (cold and short photoperiod) can alter energy balance and adipose tissue mass. To determine if photoperiod alone, independent of temperature, is a strong enough signal to regulate adiposity, we compared the effects of long and short photoperiod at thermoneutrality on adiposity and WAT gene expression in photoperiod-sensitive, F1 generation wild-derived adult male white-footed mice (Peromyscus leucopus). Mice were housed in long-day (16:8 light:dark) or short-day (8:16 light:dark) photoperiod conditions at thermoneutrality (27°C) for 4 weeks with the extended light being provided through artificial lighting. Photoperiod did not impact body weight or calorie consumption. However, mice housed in long photoperiod with extended artificial light selectively developed greater visceral WAT mass without changing subcutaneous WAT or interscapular BAT mass. This was accompanied by a decrease in Adrβ3 and Ucp1 mRNA expression in visceral WAT with no change in Pgc1a, Lpl, or Hsl. Expression of Per1, Per2, and Nr1d1 mRNA in visceral WAT differed between long and short photoperiods over time when aligned to circadian time but not onset of darkness, indicating alterations in clock gene expression with photoperiod. These findings suggest that extended photoperiod through artificial light can promote visceral fat accumulation alone, independent of temperature, supporting that artificial light may play a role in obesity.

No UCP1 in the kidney

OBJECTIVES

Several recent studies have indicated the presence of UCP1 in the kidney, challenging the paradigm that UCP1 is only found in brown and beige adipocytes and broadening the (patho)physiological significance of UCP1. The kidney localization has been the direct result of immunohistochemical investigations and an inferred outcome from multiple lines of reporter mice. These findings require confirmation and further physiological characterization.

METHODS

We examined UCP1 expression in the kidney using immunohistochemistry and qPCR. Transversal sections through or near the kidney hilum, consistently including perirenal brown fat and adjacent kidney tissue, were analyzed with four UCP1 antibodies.

RESULTS

In addition to detecting UCP1 in perirenal adipose tissue, we observed distinct immunopositive structures in the kidney with our in-house UCP1-antibody, 'C10', in apparent agreement with earlier reports. To corroborate this, we tested the C10-antibody on kidney sections from UCP1-ablated mice but found equal reactivity in these UCP1-negative tissues. We then tested the widely used antibody ab10983, previously employed in kidney studies. Also here, the positive signal persisted in UCP1-ablated mice, clearly invalidating earlier findings. UCP1 qPCR studies also failed to detect UCP1 mRNA above background. Finally, two highly specific antibodies, E9Z2V and EPR20381, accurately detected UCP1 in perirenal adipose tissue but showed no signal in the kidney.

CONCLUSIONS

When appropriate controls are implemented, there is no evidence for the presence of UCP1 in the kidney. Consequently, this conclusion also implies that the results from UCP1 reporter mice, specifically regarding kidney expression of the UCP1 gene - though possibly applicable to other tissues - require reconfirmation before being accepted as evidence for the presence of UCP1 in non-adipose tissues.

Semaglutide and bariatric surgery induce distinct changes in the composition of mouse white adipose tissue

Adipose tissue is a central player in energy balance and glucose homeostasis, expanding in the face of caloric overload in order to store energy safely. If caloric overload continues unabated, however, adipose tissue becomes dysfunctional, leading to systemic metabolic compromise in the form of insulin resistance and type 2 diabetes. Changes in adipose tissue during the development of metabolic disease are varied and complex, made all the more so by the heterogeneity of cell types within the tissue. Here we present detailed comparisons of atlases of murine WAT in the setting of diet-induced obesity, as well as after weight loss induced by either vertical sleeve gastrectomy (VSG) or treatment with the GLP-1 receptor agonist semaglutide. We focus on identifying populations of cells that return to a lean-like phenotype versus those that persist from the obese state, and examine pathways regulated in these cell types across conditions. These data provide a resource for the study of the cell type changes in WAT during weight loss, and paint a clearer picture of the differences between adipose tissue from lean animals that have never been obese, versus those that have.

Systemic effect of combined functional overload and endurance-type swimming exercise on whole body metabolism in mice

In this study, we examined the effects of concurrent functional overload and endurance exercise on muscle hypertrophy, mitochondrial function, and systemic adaptations in male mice. The mice were assigned to three groups: Sham (Sham), overload-induced hypertrophy (OL), and overload with concurrent 60-min free swimming (5 times/wk) (OL + Swim), for 4 wk. Although OL promoted muscle hypertrophy and protein synthesis through the Akt/mammalian/mechanistic target of rapamycin (mTOR) signaling pathway, the addition of swimming (OL + Swim) attenuated these effects, resulting in less pronounced muscle growth and a smaller increase in myofiber cross-sectional area. Notably, the OL + Swim group exhibited enhanced mitochondrial activity and glycogen content compared with the OL group. Both the OL and OL + Swim groups showed elevated rates of protein synthesis, with a significant upregulation of AMP-activated kinase (AMPK) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) in the OL + Swim group, suggesting enhanced mitochondrial biogenesis and adaptation. Concurrent training also resulted in systemic benefits, including reduced inguinal and epididymal white adipocyte size, improved mitochondrial enzyme activities in adipose and liver tissues, and higher levels of fibronectin type III domain containing protein 5 (FNDC5), fibroblast growth factor 21 (FGF21), and brain-derived neurotrophic factor (BDNF) in serum, which contributed to enhanced muscle protein synthesis in cultured muscle cells. These results highlight the trade-offs between muscle hypertrophy and metabolic health in mice and underscore the importance of balanced training regimens to optimize overall metabolic health and muscle function. Our results provide further insight into how concurrent strength and endurance training can be optimized for health and performance benefits.NEW & NOTEWORTHY This study provides novel insights into the mechanisms underlying the interference effect that occurs in concurrent training, highlighting the potential systemic benefits of combining resistance and endurance exercises. Despite a reduction in muscle hypertrophy, concurrent training enhances metabolic adaptations and systemic health markers and offers a comprehensive approach to improving both muscle and metabolic fitness.

Cytoskeleton regulates lipid droplet fusion and lipid storage by controlling lipid droplet movement

Lipid droplets (LDs) are highly dynamic organelles that maintain cellular lipid homeostasis through size and number control. In adipose tissue, CIDEC plays a crucial role in LD fusion and lipid homeostasis. However, the regulatory factors and mechanisms of LD fusion remain largely unknown. Here, we established a high-throughput LD phenotypic screen on a compound library consisting of 2010 small molecules, and identified 11 cytoskeleton inhibitors that negatively regulate LD size. Using specific inhibitors against each of the three types of cytoskeleton, our data showed that the disruption of microtubules and microfilaments but not intermediate filaments limits CIDEC-mediated LD fusion and growth by reducing LD movement and LD-LD contact. The collective effect of microtubule inhibitors results in a small LD phenotype which favors lipolysis upon activation of cAMP-PKA pathway in adipocytes. Our findings demonstrate that cytoskeleton is involved in the process of LD fusion and growth, indicating their role in lipid storage metabolism. One-Sentence Summary: Cytoskeleton regulates lipid droplet fusion and lipid storage.

Lactucin and lactucopicrin ameliorate obesity in high-fat diet fed mice by promoting white adipose tissue browning through the activation of the AMPK/SIRT1/PGC-1α pathway

Lactucin and lactucopicrin are the characteristic lipid-lowering active components found in Cichorium glandulosum. However, their effects and underlying mechanisms in obesity remain unclear. In the present study, C57BL/6J mice were simultaneously subjected to a high-fat diet (HFD) and treated with drugs to investigate the impacts of lactucin and lactucopicrin on HFD-induced obese mice. The results demonstrated that in HFD obese mice, lactucin and lactucopicrin significantly decreased body weight and the weights of adipose tissues, improved serum metabolic parameters, and increased the content of irisin. Regarding the intermediate metabolites of intestinal flora, which are closely associated with white adipose tissue (WAT) browning, lactucin and lactucopicrin treatment led to a reduction in the levels of 12-α-OH/non-12-α-OH bile acids (BAs) and also tended to enhance the levels of short-chain fatty acids (SCFAs). qRT-PCR results indicated that lactucin and lactucopicrin treatment elevated the expression levels of genes related to beige fat markers, thermogenesis, mitochondrial biogenesis, and lipolysis in WAT, as well as those of thermogenesis and lipolysis genes in brown adipose tissue (BAT). Western blot analysis revealed that lactucin and lactucopicrin up-regulated the expression of uncoupling protein 1 (UCP1), the core protein in thermogenesis, in both WAT and BAT. Moreover, they also up-regulated the expression levels of AMP-activated kinase (AMPK), sirtuin 1 (SIRT1), and PPARγ coactivator 1-alpha (PGC-1α), which are key pathway proteins involved in WAT browning. Furthermore, 16S rRNA sequencing results showed that in HFD obese mice, lactucin and lactucopicrin improved the composition and function of the intestinal microbiota. In conclusion, lactucin and lactucopicrin may promote WAT browning by activating the AMPK/SIRT1/PGC-1α pathway, thereby ameliorating obesity in HFD mice.