Acyl-CoA binding protein (ACBP) in Siberian sturgeon (Acipenser baerii Brandt): Characterization, synthesis and orexigenic function

Acyl-CoA binding protein (ACBP) exhibits the activity of autophagy and lipid metabolism regulation in mammals, but its indispensable role in appetite regulation has received great attention in recent years. However, its feeding regulation function in fish is unclear. In this study, we cloned the acbp gene of Siberian Sturgeon (Abacbp) which possesses high homology with those of other vertebrate species and extremely high expression in duodenum and hypothalamus. Interestingly, Abacbp mRNA was significantly increased by short-term fasting but decreased after long-term fasting and recovered after refeeding, suggesting its latent ability in appetite regulation and compensatory growth (CG). Moreover, intraperitoneal injection of Siberian sturgeon ACBP protein (AbACBP) promoted food intake and the expressions of anorexigenic factors were down-regulated and the orexigenic factors were up-regulated. In addition, the specific receptor of ACBP regulating feeding has yet to be identified. Still, our present study found that peripheral AbACBP caused the upregulation of cb1r and the inhibition of the PI3K-AKT-mTOR-S6k signal pathway in the hypothalamus. In conclusion, the research first explored the appetite-stimulating function and mechanism of ACBP. It is of great value to construct the expression strain to produce the appetite-promoting protein ACBP in large quantities for promoting the appetite of farmed animals.

The Role of Ion-Transporting Proteins on Crosstalk Between the Skeletal Muscle and Central Nervous Systems Elicited by Physical Exercise

A paradigm shift in the understanding of bidirectional interactions between peripheral and central nervous systems is essential for development of rehabilitation and preventive interventions based on physical exercise. Although a causal relationship has not been completely established, modulation of voltage-dependent ion channels (Ca2+, Cl-, K+, Na+, lactate-, H+) in skeletal and neuronal cells provides opportunities to maintain force production during exercise and reduce the risk of disease. However, there are caveats to consider when interpreting the effects of physical exercise on this bidirectional axis, since exercise protocol details (e.g., duration and intensity) have variable effects on this crosstalk. Therefore, an integrative perspective of the skeletal muscle and brain's communication pathway is discussed, and the role of physical exercise on such communication highway is explained in this review.

A dual-purification system to isolate mitochondrial subpopulations

Mitochondria perform diverse functions, including producing ATP through oxidative phosphorylation, synthesizing macromolecule precursors, maintaining redox balance among many others. Given this diversity of functions, we and others have hypothesized that cells maintain specialized subpopulations of mitochondria. To begin addressing this hypothesis, we developed a new dual-purification system to isolate subpopulations of mitochondria for chemical and biochemical analyses. We used APEX2 proximity labeling such that mitochondria were biotinylated based on proximity to another organelle. All mitochondria were isolated by an elutable MitoTag-based affinity precipitation system. Biotinylated mitochondria were then purified using immobilized avidin. We used this system to compare the proteomes of endosome- and lipid droplet-associated mitochondria in U-2 OS cells, which demonstrated that these subpopulations were indistinguishable from one another but were distinct from the global mitochondria proteome. Our results suggest that this purification system could aid in describing subpopulations that contribute to intracellular mitochondrial heterogeneity, and that this heterogeneity might be more substantial than previously imagined.

The relationship between amino acid intake patterns and both general and central obesity

BACKGROUND

Obesity is a threat to public health. Dietary protein and certain amino acids (AAs) have been associated with obesity; however, the association of AAs patterns with excess body weight has not been considered, yet. We aimed to examine the relationship between patterns of AA intake and obesity.

METHODS

This cross-sectional study was conducted on 3197 individuals aged 35 to 70 years. Sociodemographic, medical, physical activity, and anthropometric data were collected. Energy and AAs intake were obtained by food frequency questionnaire (FFQ). Factor analysis was utilized to determine the AA patterns. Using multiple logistic regression analysis, the odds ratio (OR) of obesity was calculated among individuals categorized into tertiles of the AAs patterns.

RESULTS

In this study, three AA patterns were identified. The aromatic pattern consists of phenylalanine, tryptophan, proline, glutamic acid, cysteine, serine, and leucine. Five essential AAs plus tyrosine, aspartic acid, arginine, and glycine were the components of the mixed pattern, and finally, the alanine pattern with high loadings for alanine and histidine was the third one. After adjusting for confounders, individuals in the highest tertile (T3) of the aromatic pattern had lower odds of central obesity compared to those in the lowest tertile (T1) (OR = 0.72, 95% CI: 0.58-0.89; p = 0.003), whereas this association was not observed in the alanine pattern. On the contrary, general obesity showed a positive association in T3 of the alanine pattern in comparison with T1 (OR = 1.65, 95% CI: 1.02-2.67; p = 0.039). Mixed pattern was not associated with any of the obesity types.

CONCLUSIONS

The aromatic pattern intake may have an inverse association with central obesity, and following the alanine pattern my contribute to higher odds of general obesity. However, the elaborate relationship between AAs and adiposity warrants further investigation.

Irisin Is a Potential Novel Biomarker and Therapeutic Target Against Kidney Diseases

Kidney diseases, characterized by renal dysfunction, are the leading causes of death worldwide. It is crucial to prevent and treat kidney diseases to reduce their associated morbidity and mortality. Moderate physical exercise has been recognized to be advantageous for kidney health. Irisin is an exercise-induced myokine that was identified in 2012. It plays an important role in energy and bone metabolism, oxidative stress reduction, anti-inflammatory processes, cell death inhibition, and cardiovascular protection. However, the relationship between irisin and kidney diseases have not been fully elucidated. This review explores the role of irisin as a biomarker for kidney disease diagnosis and its associated complications, as well as the mechanisms through which it participates in various cell death pathways, such as apoptosis, autophagy, pyroptosis, and ferroptosis. Furthermore, irisin secretion levels were discussed to provide a basis for kidney disease prevention and treatment avenues, as well as therapeutic guidance for developing new and promising intervention strategies. Clinical Trial Registration: None.

The choice of diet is determinative for the manifestation of UCP1-dependent diet-induced thermogenesis

The existence of the phenomenon of diet-induced thermogenesis-and its possible mediation by UCP1 in brown adipose tissue-has long been, and is presently, an important metabolic controversy. Particularly, several recent studies have failed to observe the hallmark of the phenomenon: augmentation of diet-induced obesity (i.e., fat mass) in UCP1-ablated mice, thus further casting doubt on the possible importance of this thermogenesis, for example in human metabolic control. However, scrutiny of the experimental details revealed important procedural differences between experiments that did not show or did show this augmentation of diet-induced obesity. Particularly, there were notable differences between the commercial diets used (Research Diets or Ssniff). We, therefore, tested to what degree these differences would suffice to explain the absence of a UCP1 effect. Wild-type mice fed Research Diets high-fat diet became obese, but UCP1-ablated mice became even more obese, as expected if UCP1-dependent diet-induced thermogenesis exists. Mice fed the Ssniff high-fat diet became less obese than those on the Research Diets food-and, importantly, no effect of UCP1 ablation was seen. The result with the Research Diets diet was fully due to differences in total fat mass and not explainable by differences in food intake. The two diets are different in carbohydrate (sucrose) and lipid (lard vs. palm oil) composition and in texture and taste. Probably some of these factors explain the difference, but the important conclusion is that when an appropriate diet was offered, the body weight manifestation of the phenomenon of UCP1-dependent diet-induced thermogenesis was a reproducible phenomenon, the existence of which may have significance also for human metabolic control.NEW & NOTEWORTHY A main reason for the present interest in brown adipose tissue in humans is the possibility that this tissue mediates diet-induced thermogenesis, i.e., the ability to combust some of the foods eaten, thus lessening the burden of obesity. However, several recent papers have queried the existence of diet-induced thermogenesis. We demonstrate that these negative observations are explainable by the types of diet offered, and diet-induced thermogenesis thus remains a potentially important contributor to metabolic equilibrium.

Sarcopenia in Peritoneal Dialysis: Prevalence, Pathophysiology, and Management Strategies

Sarcopenia, defined as the loss of skeletal muscle mass, strength, and function, is a significant complication in patients with chronic kidney disease, particularly those undergoing peritoneal dialysis (PD). This review explores the prevalence, pathophysiology, diagnostic challenges, and management strategies of sarcopenia in the PD population. The multifactorial etiology of sarcopenia in PD, including protein-energy wasting, chronic inflammation, insulin resistance, and hormonal imbalances, underscores the complexity of its management. The prevalence of sarcopenia in patients treated with PD is influenced by age, duration of dialysis, and comorbid conditions, presenting a considerable variation across studies due to differing diagnostic criteria. Diagnostic challenges arise from fluid overload and the PD process, affecting the accuracy of muscle mass measurements. Intervention strategies focusing on nutritional supplementation and physical exercise have shown promise; however, the need for PD-specific diagnostic criteria and treatment protocols remains. This review highlights the critical effect of sarcopenia on functional status and survival in patients treated with PD, emphasizing the importance of addressing this condition to improve patient outcomes. Future directions call for comprehensive, longitudinal studies to better understand sarcopenia's progression in patients treated with PD and the development of tailored interventions.

Potential protective role of Lycium ruthenicum Murray polysaccharides against lipopolysaccharide-induced liver injury via mitochondrial biogenesis

Acute liver injury (ALI), which manifests as abnormal liver function and hepatocyte damage, lacks effective treatment modalities and is associated with a high mortality rate. Recent studies have revealed that hepatoprotection is related to polysaccharide components. In this study, we examined the effect and mechanism of Lycium ruthenicum Murray polysaccharides (LRMP) on liver injury induced by lipopolysaccharide (LPS). Male ICR mice were pre-administered LRMP (100 and 400 mg/kg BW) once daily for 21 days. A single injection of LPS (10 mg/kg BW) was administered on day 21 to induce ALI. The difference between the groups indicated that LRMP supplementation had no adverse effect on body weight. LRMP administration considerably alleviated liver injury, as evidenced by the decreased levels of aspartate transaminase and alanine transaminase, increased levels of albumin, and preservation of liver structural integrity. Moreover, LRMP reduced oxidative stress and inflammatory responses in the liver, maintained mitochondrial structure, regulated mitochondrial apoptotic pathway, and upregulated Sirtuin 1/peroxisome proliferator-activated receptor γ coactivator-1α signalling pathway involved in mitochondrial biogenesis. This study suggests the potential therapeutic application of LRMP in liver-related diseases, which will provide a basis for innovative strategies.

Low molecular weight protein tyrosine phosphatase: A driver of lipid metabolic remodeling in Caenorhabditis elegans

As a member of the class II cysteine-based protein tyrosine phosphatases, low molecular weight protein tyrosine phosphatase (LMWPTP) plays a pivotal role in animal physiology, particularly in signaling transduction, but its specific function in lipid metabolism remains poorly understood. Herein, the structure and metabolic functions of LMWPTP were investigated using the Caenorhabditis elegans (C. elegans) as a convenient model. The nematode LMWPTP was found to be highly conserved in sequence, functional domains, and tertiary structure compared to its mammalian homologs. Through RNA interference (RNAi) targeting lmwptp, we observed a modest increase in lipid accumulation in nematodes, evidenced by higher triglyceride levels, enlarged lipid droplets, and an increase in total fatty acid content, despite no changes in body size. Mechanistically, lmwptp RNAi promoted adipogenesis by modulating the insulin-like growth factor 1 signaling pathway, facilitating the nuclear translocation of DAF-16, which in turn upregulated fat-7 expression. Furthermore, increased ROS levels were associated with enhanced lipogenesis. The knockdown of lmwptp also attenuated lipolysis and lipophagy via modulation of the AMPK pathway. Despite these alterations, key physiological functions related to energy metabolism were preserved, and lifespan was extended with delayed aging markers. These findings highlight LMWPTP's significant role in lipid regulation, offering new insights and potential therapeutic targets for human lipid metabolism disorders.

Brd9 antagonism induces beige adipocytes in white adipose tissues and protects against diet-induced obesity

OBJECTIVE

Thermogenic beige adipocytes emerge in white adipose tissue (WAT) under certain physiological and pathological conditions, leading to increased energy expenditure, insulin sensitivity, and glucose tolerance. The induction of beige adipocyte formation represents a promising therapeutic approach for obesity and associated chronic diseases; however, the mechanisms controlling WAT beiging remain incompletely understood.

METHODS

We conducted a genome-wide knockout screening in the white adipose progenitors of mice to identify lineage repressors of beige adipocyte formation. We further investigated the metabolic effects and gene expression alterations upon Brd9 antagonism in obesity mouse models.

RESULTS

An unbiased genetic screen identified the following four lineage repressors of beige adipocytes: Brd9; Ankib1; Cacng1; and Cfap20. Knockout of each gene individually promoted beige adipocyte differentiation in vitro and WAT beiging in vivo. In diet-induced obesity mouse models, oral administration of Brd9 inhibitors induced beige adipocytes within subcutaneous and visceral WAT, enhanced thermogenic gene expression in brown adipose tissue, and suppressed gluconeogenic gene expression in the liver. These beneficial effects were concomitant with augmented whole-body energy expenditure, reduced body weight/adiposity, and improved endurance and glucose metabolism.

CONCLUSIONS

Antagonism of Brd9 and other beige lineage repressors may have significant implications for therapeutic induction of WAT beiging and thermogenesis to treat obesity and its associated chronic diseases.

Human umbilical cord mesenchymal stem cells improve bone marrow hematopoiesis through regulation of bone marrow adipose tissue

Bone marrow adipose tissue (BMAT) exhibits a multitude of biological functionalities and influences hematopoiesis. The adiposity status of the bone marrow may play a role in the decline of hematopoietic function. Mesenchymal stem cells (MSCs) constitute crucial regulators within the bone marrow microenvironment; however, their precise role in modulating BMAT and the subsequent implications for hematopoiesis remain poorly understood. We conducted in vivo studies to observe the effects of human umbilical cord mesenchymal stem cells (hucMSCs) on BMAT accumulation and restoration of hematopoietic function in mice with drug-induced hematopoietic impairment. Concurrently, in vitro co-culture experiments were used to investigate the impact of hucMSCs on preadipocytes and mature adipocytes, and the potential subsequent consequences for hematopoietic cells. Moreover, we explored the potential mechanisms underlying these interactions. Our findings reveal that hucMSCs concomitantly mitigate BMAT accumulation and facilitate the recovery of hematopoietic function in mouse models with drug-induced hematopoietic impairment. In vitro, hucMSCs potentially impede adipogenic differentiation of 3T3-L1 preadipocytes through interference with the JAK2/STAT3 signaling pathway and affect the functionality of mature adipocytes, thus mitigating the detrimental effects of adipocytes on hematopoietic stem cells (HSCs). Furthermore, we demonstrate that hucMSCs may protect hematopoietic cells from adipocyte-induced damage by protecting antioxidative mechanisms. These results suggest that hucMSCs exhibit an inhibitory effect on the excessive expansion of adipose tissue and modulate adipose tissue function, which may potentially contribute to the regulation of the bone marrow microenvironment and favorably influence hematopoietic function improvement.

Repression of peroxisome proliferation-activated receptor γ coactivator-1α by p53 after kidney injury promotes mitochondrial damage and maladaptive kidney repair

Maladaptive kidney repair after injury is associated with a loss of mitochondrial homeostasis, but the underlying mechanism is largely unknown. Moreover, it remains unclear whether this mitochondrial change contributes to maladaptive kidney repair or the development of chronic kidney problems after injury. Here, we report that the transcriptional coactivator peroxisome proliferation-activated receptor γ coactivator-1α (PGC1a), a master regulator of mitochondrial biogenesis, was persistently downregulated during maladaptive kidney repair after repeated low-dose cisplatin nephrotoxicity or unilateral ischemia/reperfusion injury. Administration of the PGC1α activator ZLN005 after either kidney injury not only preserved mitochondria but also attenuated kidney dysfunction, tubular damage, interstitial fibrosis, and inflammation. PGC1α downregulation in these models was associated with p53 activation. Notably, knockout of p53 from proximal tubules prevented PGC1α downregulation, attenuated chronic kidney pathologies and minimized functional decline. Inhibition of p53 with pifithrin-α, a cell permeable p53 inhibitor, had similar effects. Mechanistically, p53 bound to the PGC1α gene promoter during maladaptive kidney repair, and this binding was suppressed by pifithrin-α. Together, our results indicate that p53 is induced during maladaptive kidney repair to repress PGC1α transcriptionally, resulting in mitochondrial dysfunction for the development of chronic kidney problems. Activation of PGC1α and inhibition of p53 may improve kidney repair after injury and prevent the development of chronic kidney problems.

The Therapeutic Potential of Theobromine in Obesity: A Comprehensive Review

Obesity, characterized by chronic low-grade inflammation, is a significant health concern. Phytochemicals found in plants are being explored for therapeutic use, particularly in combating obesity. Among these, theobromine, commonly found in cocoa and chocolate, shows promise. Although not as extensively studied as caffeine, theobromine exhibits positive effects on human health. It improves lipid profiles, aids in asthma treatment, lowers blood pressure, regulates gut microbiota, reduces tumor formation, moderates blood glucose levels, and acts as a neuroprotective agent. Studies demonstrate its anti-obesity effects through mechanisms such as browning of white adipose tissue, activation of brown adipose tissue, anti-inflammatory properties, and reduction of oxidative stress. This study aims to suggest theobromine as a potential therapeutic agent against obesity-related complications.

Role of Perivascular Adipose Tissue in Vein Remodeling

Perivascular adipose tissue (PVAT) plays a crucial, yet underexplored, role in vein remodeling, which occurs after bypass surgery using a venous graft or creation of arteriovenous fistulae for hemodialysis access. PVAT exhibits significant heterogeneity in phenotype and tissue composition depending on the vascular bed, as well as its anatomic location within the vasculature. Through the excretion of adipokines, cytokines, and chemokines, PVAT can shape the vascular response to local and systemic perturbations. Moreover, the active exchange of cells reinforces the bidirectional cross talk between the vessel wall and PVAT. In this review, we describe the role of PVAT in relation to postinterventional vein remodeling, specifically focusing on the effect of surgery on the PVAT phenotype. Moreover, we discuss the pathophysiological mechanisms that ultimately affect clinical outcomes and highlight the therapeutic potential of PVAT to improve vein remodeling.

Cardiac energy metabolism in diabetes: emerging therapeutic targets and clinical implications

Patients with diabetes are at an increased risk for developing diabetic cardiomyopathy and other cardiovascular complications. Alterations in cardiac energy metabolism in patients with diabetes, including an increase in mitochondrial fatty acid oxidation and a decrease in glucose oxidation, are important contributing factors to this increase in cardiovascular disease. A switch from glucose oxidation to fatty acid oxidation not only decreases cardiac efficiency due to increased oxygen consumption but it can also increase reactive oxygen species production, increase lipotoxicity, and redirect glucose into other metabolic pathways that, combined, can lead to heart dysfunction. Currently, there is a lack of therapeutics available to treat diabetes-induced heart failure that specifically target cardiac energy metabolism. However, it is becoming apparent that part of the benefit of existing agents such as GLP-1 receptor agonists and sodium-glucose cotransporter 2 inhibitors may be related to their effects on cardiac energy metabolism. In addition, direct approaches aimed at inhibiting cardiac fatty acid oxidation or increasing glucose oxidation hold future promise as potential therapeutic approaches to treat diabetes-induced cardiovascular disease.

CIDEB promotes lipid deposition in goat intramuscular adipocytes

OBJECTIVE

Cell death-inducing DNA fragmentation factor alpha-like effector B (CIDEB), a family member of Cell death-inducing DFF45-like effectors (CIDEs), is well known as a crucial regulator for lipid metabolic signaling pathways in various metabolic tissues and secretory glands. However, its role in regulating intramuscular fat (IMF) deposition in goat remains unclear.

METHODS

The expression vector pcDNA3.1-CIDEB was constructed and transfected into goat intramuscular preadipocytes; the overexpression and interference efficiency and expression of genes related to lipid metabolism were measured by Real-time polymerase chain reaction; the effect of overexpression of CIDEB and interfering with CIDEB on lipid droplet formation was observed by Oil Red O staining and glycerol phosphate oxidase-Trinder enzymatic reaction. Then RNA-Seq was used to investigate the metabolic pathway of CIDEB affecting adipocyte deposition in goat intramuscular preadipocytes.

RESULTS

Overexpression of CIDEB significantly promoted the lipid droplets accumulation and the triglyceride deposition, and significantly upregulated the expression of genes related to lipid metabolism. After overexpression of CIDEB in goat intramuscular preadipocytes, 171 differentially expressed genes (DEGs) were found, including 122 up-regulated and 49 down-regulated DEGs, and the top three significantly changed pathways filtered by Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were Cocaine addiction, Amphetamine addiction and Malaria pathways. Conversely, the silencing of CIDEB significantly reduced lipid accumulation in goat intramuscular preadipocytes, meanwhile changing the expression of lipid metabolism genes. For CIDEB silencing, a total of 2140 DEGs were found, including 1252 up-regulated and 888 down-regulated DEGs, and the top three significantly changed pathways filtered by KEGG analysis were Ribosome, Thyroid hormone signaling pathway and Alzheimer disease.

CONCLUSION

The expression of CIDEB can significantly promote lipid deposition of intramuscular adipocytes in goats, and these results provide important data to support further clarifying the mechanism of CIDEB gene on the regulation of intramuscular adipogenesis, and the IMF formation in goats.

(+)-Terrein exerts anti-obesity and anti-diabetic effects by regulating the differentiation and thermogenesis of brown adipocytes in mice fed a high-fat diet

OBJECTIVE

(+)-Terrein, a low-molecular-weight secondary metabolite from Aspergillus terreus, inhibits adipocyte differentiation in vitro. However, the precise mechanisms underlying the effects of (+)-terrein on adipocytes remain unclear. We hypothesized that (+)-terrein modulates adipogenesis and glucose homeostasis in obesity and diabetes via anti-inflammatory action and regulation of adipocyte differentiation. Hence, in this study, we aimed to investigate the in vivo anti-diabetic and anti-obesity effects of (+)-terrein.

METHODS

Male C57BL/6 J mice were fed normal chow or high-fat (HF) diet and administered (+)-terrein (180 mg/kg) via intraperitoneal injection. Glucose and insulin tolerance tests, serum biochemical assays, and histological analyses were also performed. Rat brown preadipocytes, mouse brown preadipocytes (T37i cells), and inguinal white adipose tissue (ingWAT) preadipocytes were exposed to (+)-terrein during in vitro adipocyte differentiation. Molecular markers associated with thermogenesis and differentiation were quantified using real-time polymerase chain reaction and western blotting.

RESULTS

(+)-Terrein-treated mice exhibited improved insulin sensitivity and reduced serum lipid and glucose levels, irrespective of the diet. Furthermore, (+)-terrein suppressed body weight gain and mitigated fat accumulation by activating brown adipose tissue in HF-fed mice. (+)-Terrein facilitated the in vitro differentiation of rat brown preadipocytes, T37i cells, and ingWAT preadipocytes by upregulating peroxisome proliferator-activated receptor-γ (PPARγ). This effect was synergistic with that of a PPARγ agonist.

CONCLUSION

This study demonstrated that (+)-terrein effectively induces PPARγ expression and brown adipocyte differentiation, leading to reduced weight gain and improved glucose and lipid profiles in HF-fed mice. Thus, (+)-terrein is a potent novel agent with potential anti-obesity and anti-diabetic properties.

Enhanced Metabolic Syndrome Management Through Cannabidiol-Loaded PLGA Nanoparticles: Development and In Vitro Evaluation

Cannabidiol (CBD) holds promise for managing metabolic diseases, yet enhancing its oral bioavailability and efficacy remains challenging. To address this, we developed polymeric nanoparticles (NPs), using poly(lactic-co-glycolic acid) (PLGA), encapsulating CBD using nanoprecipitation, aiming to create an effective CBD-nanoformulation for metabolic disorder treatment. These NPs (135-265 nm) demonstrated high encapsulation efficiency (EE% ≈ 100%) and sustained release kinetics. Their therapeutic potential was evaluated in an in vitro metabolic syndrome model employing sodium palmitate-induced HepG2 cells. Key assessment parameters included cell viability (MTT assay), glucose uptake, lipid accumulation (Oil Red O staining), triglycerides, cholesterol, HDL-c levels, and gene expression of metabolic regulators. Results showed an IC50 of 9.85 μg/mL for free CBD and 11.26 μg/mL for CBD-loaded NPs. CBD-loaded NPs significantly enhanced glucose uptake, reduced lipid content, lowered triglycerides and total cholesterol, and increased HDL-c levels compared to free CBD. Gene analysis indicated reduced gluconeogenesis via downregulation of PPARγ, FOXO-1, PEPCK, and G6Pase and enhanced fatty acid oxidation through CPT-1 upregulation. These findings suggest that CBD-loaded NPs may serve as a novel therapeutic strategy for the management of metabolic disorders, warranting further in vivo studies.

Insulin‑like growth factor 2 in spermatogenesis dysfunction (Review)

Spermatogenesis dysfunction is characterized by abnormal morphology, destruction, atrophy of seminiferous tubules, blocked differentiation of spermatogenic cells, decreased sperm count and increased sperm abnormalities. Inflammation, oxidative stress, endoplasmic reticulum stress and obesity are important factors leading to spermatogenesis dysfunction. It has been demonstrated that insulin‑like growth factor 2 (IGF2) is closely related to the aforementioned factors. In the present review, the relationship between IGF2 and inflammation, oxidative stress, ER stress and obesity was investigated, providing theoretical and experimental evidence on the role of IGF2 in the prevention and treatment of spermatogenesis dysfunction of male infertility.

Polystyrene-microplastics and Emamectin Benzoate co-exposure induced lipid remodeling by suppressing PPARα signals to drive ACSL4-dependent ferroptosis and carp splenic injury

Microplastics (MPs) and Emamectin Benzoate (EMB) were identified as hazardous environmental pollutants, frequently coexisting in aquatic ecosystems, posing potential risk in the immune system of human and animal. However, the hazards of concurrent exposed to MPs and EMB on the carp spleen, and the specific mechanisms remain unclear. Here, we employed MPs and EMB-exposed carp models, and cultured splenocytes in vitro, to demonstrate that PPARα signals suppression underlay MPs and EMB-induced carp spleen injury, based on transcriptomics and lipomics analysis. This suppression exacerbated the buildup of polyunsaturated fatty acid (PUFA), and promoted ACSL4 expression, resulting in increased lipid peroxidation. Further studies found that the accumulation of lipid peroxides predominantly occurred in the mitochondria, which evoked mitochondrial homeostasis imbalance and compromised mitochondrial function, thereby initiating ferroptosis. Additionally, enhancing PPARα signaling, inhibiting ACSL4, or scavenging mitochondrial ROS was favor of mitigating accumulation of lipid peroxides, reducing mitochondrial damage and inhibiting ferroptosis. Notably, MPs and EMB co-exposure caused more severe damage than single exposure. These findings uncovered a potential mechanism, involving PPARα signaling inhibition by MPs and EMB co-exposure, which evoked lipid remodeling and increased ACSL4, to drive ferroptosis and carp splenic injury. This study highlighted the potential hazards to the aquaculture environments where co-exposure of MPs and EMB and provided reference for environmental toxicology research and the sustainable development of the aquaculture industry.

EPA but not DHA prevents lipid metabolism disorders by regulating myogenic IL-6 in high-fat fed mice

Lipid metabolism disorder serve as a critical starting point for the development of chronic non-communicable diseases (NCDs). Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA) are known for their lipid-lowering properties, but few studies have revealed their differences from the perspective of skeletal muscle endocrinology. Myogenic IL-6 has garnered significant attention for its role in energy distribution. The primary aim of this study was to investigate the effects and mechanisms of EPA and DHA on myogenic IL-6 and lipid metabolism disorders in mice, and to clarify the association between the alleviation of lipid metabolism disorders and myogenic IL-6 mediated by EPA/DHA. We found that EPA and DHA not only prevented high-fat diet-induced lipid metabolism disorders, but also up-regulated the expression of myogenic IL-6 by activating TRPV1/Ca2+ signaling in skeletal muscle. However, the lipid metabolism prevention effect mediated by EPA was weakened after knockout gene of myogenic IL-6, with its body weight and body fat increased and a large amounts of lipid deposited in the blood, liver, and adipocytes. Meanwhile, there no significantly differences of AMPK/STAT3 signaling in adipose tissue between groups after knockout gene of myogenic IL-6. Based on the results above, we concluded that EPA and DHA can stimulate the production of myogenic IL-6 through TRPV1/Ca2+ signaling in skeletal muscle. The prevention effect of lipid metabolism disorders by EPA, but not DHA, relies on myogenic IL-6, with the underlying mechanism may involving the enhancement of AMPK/STAT3 signaling mediated by myogenic IL-6 in adipose tissues.

Recent advances in targeting obesity, with a focus on TGF-β signaling and vagus nerve innervation

Over a third of the global population is affected by obesity, fatty liver disease (Metabolic Dysfunction-Associated Steatotic Liver Disease, MASLD), and its severe form, MASH (Metabolic Dysfunction-Associated Steatohepatitis), which can ultimately progress to hepatocellular carcinoma (HCC). Recent advancements include therapeutics such as glucagon-like peptide 1 (GLP-1) agonists and neural/vagal modulation strategies for these disorders. Among the many pathways regulating these conditions, emerging insights into transforming growth factor-β (TGF-β) signaling highlight potential future targets through its role in pathophysiological processes such as adipogenesis, inflammation, and fibrosis. Vagus nerve innervation in the gastrointestinal tract is involved in satiety regulation and energy homeostasis, and vagus nerve stimulation has been applied in weight loss and diabetes. This review explores clinical trials in obesity, novel therapeutic targets, and the role of TGF-β signaling and vagus nerve modulation in obesity-related liver diseases and HCC.

Comparative effect of high intensity interval training and moderate intensity continuous training on metabolic improvements and regulation of Cidea and Cidec in obese C57BL/6 mice

Obesity is a chronic disease associated with increased risk of cardiovascular disease, diabetes, metabolic dysfunction associated steatotic liver disease and certain cancers. High intensity interval training (HIIT) and moderate intensity continuous training (MICT) are effective in preventing and managing obesity. However, the comparative effects of these modalities on metabolic disorders need to be better mechanistically explored. This study aimed to comprehensively assess the effects of MICT and HIIT on key metabolic organs and underlying mechanisms. C57BL/6 mice were randomized to receive either a chow diet or high fat diet for 12 weeks, followed by random assignment of high-fat-fed mice to no exercise, MICT or HIIT groups for additional 5 weeks. At the end, both HIIT and MICT significantly alleviated high-fat-induced weight gain and lipids disorder and impaired liver function. HIIT was more effective in enhancing insulin sensitivity, ameliorating hepatic steatosis, reducing adipocyte hypertrophy. Additionally, HIIT restored the high-fat-induced downregulation of Cidea, Cidec and Atgl in inguinal white adipose tissue and liver. Furthermore, HIIT resulted in upregulation of interleukin 6 (Il-6) in skeletal muscle. The exogenous addition of Il-6 to primary white adipocytes significantly downregulated Cidec, and up-regulated Atgl expression. In conclusion, HIIT is superior to MICT in improving metabolic dysfunction, likely mediated through Il-6-induced downregulation of Cidea and Cidec, thereby promoting lipolysis.

Cytochrome P450 2E1 aggravates DXR-induced myocardial injury through imbalanced mitochondrial OPA1

BACKGROUND

Cytochrome P450 2E1 (CYP2E1), a drug metabolism enzyme, is linked to multiple pathophysiological states in the myocardium and may act as a sensor of heart diseases. However, the exact mechanisms of CYP2E1 in myocardial injury, particularly in chemotherapeutic agent-induced myocardial damage such as doxorubicin-induced cardiotoxicity, remain unclear.

METHODS

Using multiple animal models of cardiomyopathy and heart failure, we observed CYP2E1 expression in myocardial mitochondria. Myocardium-specific CYP2E1 overexpression and knockout rat models were employed to study its effects on myocardial injury, assessed via echocardiography and histopathology. Mechanistic insights were derived from transcriptome analysis, mass spectrometry, co-immunoprecipitation, signal transduction analysis, and molecular biology techniques.

RESULTS

CYP2E1 overexpression accelerated, while CYP2E1 knockout inhibited, myocardial injury in DXR-induced cardiomyopathy and isoprenaline-induced hypertrophic cardiomyopathy. Mechanistically, CYP2E1 was upregulated specifically in myocardial mitochondria during heart disease. This upregulation resulted in mitochondrial fragmentation and dysfunction under DXR-induced stress. CYP2E1 interacted with optic atrophy 1 (OPA1) in the inner mitochondrial membrane, leading to an imbalance between long and short OPA1 isoforms.

CONCLUSIONS

CYP2E1 disrupts OPA1-mediated mitochondrial dynamics, causing mitochondrial fragmentation and apoptosis, which aggravate myocardial injury. Targeting CYP2E1 may offer a therapeutic strategy to mitigate myocardial damage, particularly in chemotherapeutic drug-induced cardiotoxicity.

PPARα regulates ER-lipid droplet protein Calsyntenin-3β to promote ketogenesis in hepatocytes

Ketogenesis requires fatty acid flux from intracellular (lipid droplets) and extrahepatic (adipose tissue) lipid stores to hepatocyte mitochondria. However, whether interorganelle contact sites regulate this process is unknown. Recent studies have revealed a role for Calsyntenin-3β (CLSTN3β), an endoplasmic reticulum-lipid droplet contact site protein, in the control of lipid utilization in adipose tissue. Here, we show that Clstn3b expression is induced in the liver by the nuclear receptor PPARα in settings of high lipid utilization, including fasting and ketogenic diet feeding. Hepatocyte-specific loss of CLSTN3β in mice impairs ketogenesis independent of changes in PPARα activation. Conversely, hepatic overexpression of CLSTN3β promotes ketogenesis in mice. Mechanistically, CLSTN3β affects LD-mitochondria crosstalk, as evidenced by changes in fatty acid oxidation, lipid-dependent mitochondrial respiration, and the mitochondrial integrated stress response. These findings define a function for CLSTN3β-dependent membrane contacts in hepatic lipid utilization and ketogenesis.

Evaluating obesity and fat cells as possible important metabolic players in childhood leukemia

INTRODUCTION

The prevalence of overweight and obesity in childhood is a health challenge. This condition induces alterations in adipose tissue and metabolic disorders such as diabetes, dyslipidemia, and hypertension even in childhood and may also be associated with cancer development. Underlying mechanisms related to childhood cancer, such as leukemia and obesity, are not entirely understood.

CONTENT

Considering this scenario, a systematic literature review was performed on the PubMed library. Studies that evaluate the association between overweight or obesity at diagnosis of childhood leukemia and the outcomes associated with this condition were included.

SUMMARY

In some studies, a worse prognosis was observed in obese children compared to non-obese, which begs the question of how the adipose tissue environment may be involved with leukemia progression and its outcomes such as relapse, overall and event-free survival and infections.

OUTLOOK

Obesity in children diagnosed with leukemia may be associated with poor outcomes during disease progression as reported in some studies. The remodeling and composition of adipose tissue, alterations in adipocytokines secretion, such as leptin, and inflammation that may trigger awakened oncogenes seem to be important players in cancer development and outcomes during treatment. Understanding if there is any relationship between adipose tissue and the development of childhood leukemia and its prognosis, as well as the biological mechanisms of this scenario, is important to contribute to improving the treatment protocols and survival, especially in obese children.

The Evolving Role of Macrophage Metabolic Reprogramming in Obesity

Recent research has extensively explored the critical role of energy metabolism in shaping the inflammatory response and polarization of macrophages in obesity. This rapidly growing field emphasizes the need to understand the connection between metabolic processes that support macrophage polarization in obesity. While most published research in this area has focused on glucose and fatty acids, how the flux through other metabolic pathways (such as ketone and amino acid oxidation) in macrophages is altered in obesity is not well defined. This review summarizes the main alterations in uptake, storage, and oxidation of oxidative substrates (glucose, fatty acids, ketone bodies and amino acids) in macrophages and how these alterations are linked to macrophage polarization and contribution to augmented inflammatory markers in obesity. The review also discusses how oxidative substrates could modulate macrophage energy metabolism and inflammatory responses via feeding into other non-oxidative pathways (such as the pentose phosphate pathway, triacylglycerol synthesis/accumulation), via acting as signalling molecules, or via mediating post-translational modifications (such as O-GlcNAcylation or β-hydroxybutyrylation). The review also identifies several critical unanswered questions regarding the characteristics (functional and metabolic) of macrophages from different origins (adipose tissue, skeletal muscle, bone marrow) in obesity and how these characteristics contribute to early vs late phases of obesity. We also identified a number of new therapeutic targets that could be evaluated in future investigations. Targeting macrophage metabolism in obesity is an exciting and active area of research with significant potential to help identify new treatments to limit the detrimental effects of inflammation in obesity.

Exercise-mediated muscle-hypothalamus crosstalk: Improvement for cognitive dysfunction caused by disrupted circadian rhythm

In contemporary societal evolution, the increasing disruption of the natural sleep-wake cycle, attributable to factors such as shift work and overexposure to artificial light, has been paralleled by a marked escalation in the incidence of cognitive impairments and the prevalence of neurodegenerative diseases. Current management strategies for cognitive impairments include pharmacological and non-pharmacological interventions. Pharmacological interventions for cognitive impairments typically involve medications to manage cognitive symptoms and improve neurological functions. However, these drugs show limited long-term efficacy in slowing disease progression and may cause side effects. Given the widespread occurrence of cognitive dysfunction, it is crucial to develop accessible non-pharmacological interventions. Physical activity and exercise have emerged as pivotal lifestyle determinants known to exert a modulatory effect on the risk profile for cognitive dysfunction caused by disrupted circadian rhythms. The skeletal muscle, a dynamic tissue, undergoes a profound morphological and metabolic reconfiguration in response to physical exertion, along with the secretion of myokines. Additionally, the hypothalamus, particularly the ventromedial nuclei, arcuate nuclei, and the suprachiasmatic nucleus, have crucial functions in regulating physical activity, influencing energy metabolism, and managing circadian cycles. Nevertheless, the communication between the hypothalamus and skeletal muscle during exercise is not fully understood. This narrative review integrates current knowledge on the interaction between the hypothalamus and skeletal muscle during exercise, emphasizing its neuroendocrine effects and potential therapeutic implications for alleviating cognitive dysfunction associated with disrupted circadian rhythms.

Lipid droplets: Emerging therapeutic targets for age-related metabolic diseases

Lipids metabolism is crucial in regulating aging and metabolic diseases. Lipid droplets (LDs) are dynamic, complex organelles responsible for the storage and release of neutral lipids, essential for maintaining lipid homeostasis and energy metabolism. Aging accelerates the accumulation of LDs, functional deterioration, and metabolic disorders, thereby inducing age-related metabolic diseases (ARMDs). This review examines published datasets on the association between LDs and ARMDs, focusing on the structure and function of LDs, their interactions with other organelles, and associated proteins. Furthermore, we explore the potential mechanisms by which LDs mediate the onset of ARMDs, including Alzheimer's disease (AD), sarcopenia, metabolic cardiomyopathy, non-alcoholic fatty liver disease (NAFLD), and cancer. Lastly, we discuss intervention strategies aimed at targeting LDs to improve outcomes in ARMDs, including exercise, dietary, and pharmacological interventions.

The metabolic underpinnings of sebaceous lipogenesis

Sebaceous glands synthesize and secrete sebum, a mélange of lipids and other cellular products that safeguards the mammalian integument. Differentiating sebocytes delaminate from the basal membrane and dislodge towards the gland's middle, where they eventually undergo a poorly understood death mode in which the whole cell becomes a secretion product (holocrine secretion). Supported by recent transcriptomics data, this review examines the idea that peripheral sebocytes have a remarkable ability to draw nutrients from the blood and become committed to unrestrainedly invest all available resources into synthetic processes for accomplishing sebum synthesis, thereby exploiting core metabolic fluxes as glycogen turnover, glutamine-directed anaplerosis, the pentose phosphate pathway and de novo lipogenesis. Finally, we propose that metabolic-driven processes are an important mechanistic component of holocrine secretion. A deeper understanding of these metabolic adaptations could indicate novel strategies for modulating sebum synthesis, a key pathogenic factor in acne and other skin diseases.

Modes of Mitochondrial Reactive Oxygen Species Production in Inflammation

Background: Inflammation is one of the most important pathways in innate immunity and its relationship with redox biology is becoming increasingly clear in the last decades. However, the specific redox modes and pathways by which inflammation is produced are not yet well defined. Significance: In this review, we provide a general explanation of the reactive oxygen species (ROS) production and quenching modes occurring in mammalian mitochondria, as well as a summary of the most recent advances in mitochondrial redox biology and bioenergetics regarding sodium (Na+) homeostasis. In addition, we provide a collection of examples in which several inflammatory pathways have been associated with specific modes of either mitochondrial ROS production or quenching. Innovation: The role of Na+ in mitochondrial biology is being developed. Since its discovery as a second messenger, the research of its role in the immune system has emerged. Now, the role of Na+ in mitochondrial bioenergetics has recently been identified, which owns unprecedented applications. The potential implication of Na+ in inflammatory mechanisms grows as its role does not only cover ROS production and respiration but also the control through the management of mitochondrial membrane potential. Future directions: Na+ is becoming relevant for mitochondrial biology. Thus, processes regarding mitochondrial bioenergetics, redox state, or metabolism may probably need to include the study of Na+ in their road map. Some of these pathways are involved in inflammation and more are possibly to come. This review is expected to serve as a bridge between both fields. Antioxid. Redox Signal. 00, 000-000.

PGC-1α role in rescuing ferroptosis in cerebral ischemia/reperfusion injury through promoting mitochondrial biogenesis and UCP2 expression

Cerebral ischemia/reperfusion injury (CIRI) is a critical factor leading to adverse outcomes in acute ischemic stroke with reperfusion therapy. The occurrence of CIRI involves several cell death pathways, such as ferroptosis. Peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) a vital role in mitochondrial biogenesis and induces several crucial reactive oxygen species (ROS) detoxifying enzymes. Nonetheless, the role of activated PGC-1α in CIRI is still unclear. In this research, we utilized a PGC-1α agonist (ZLN005) in both in vitro and in vivo models of CIRI and found that ZLN005 ameliorates neurologic deficits, reduces infarct volume, and inhibits neuronal ferroptosis in CIRI. Furthermore, CIRI led to a decrease in neuronal mitochondrial quantity and downregulation of uncoupling protein 2 (UCP2) expression. Treatment with ZLN005 activated PGC-1α, promoted neuronal mitochondrial biogenesis, and upregulated UCP2 expression, thereby reducing mitochondrial oxidative stress. The application of the mitochondria-targeted antioxidant Mito-TEMPO inhibited ferroptosis, while UCP2 silencing induced mitochondrial oxidative stress and weakened ZLN005 inhibitory effect of ferroptosis, confirming the dependency of ferroptosis on mitochondrial oxidative stress in CIRI. According to these findings, targeting PGC-1α may offer an effective therapeutic strategy for CIRI by regulating mitochondrial homeostasis and protecting neurons from ferroptotic damage.

Pituitary folliculo-stellate cells modulate tumor vasculature and extracellular matrix composition in experimental lactosomatotropinomas

Folliculo-stellate cells (FSCs) constitute 5-10 % of the adenohypophysis and have been proposed as paracrine regulators of pituitary cells. However, their participation in pituitary tumor development remains unclear. We generated a lacto-somatotropic tumor model by subcutaneous injection of GH3 (lacto-somatotrophs) and the FSCs TtT/GF, isolated or combined, in immunodeficient mice, to study the role of the FSCs on tumor formation, hormone secretion, vascularization and extra-cellular matrix involvement. The co-culture of both cell lines let us gain insight into the proliferative and secretory action of FSC in pituitary tumor modulation. Our results showed that initially GH3:TtT/GF tumors had an earlier onset, but lately, TtT/GF cells restrained GH3:TtT/GF tumor growth and their Prl synthesis, although no differences were observed in the proliferative potential of tumor cells in vivo. Instead, TtT/GF cells exerted a direct mitogenic action on GH3 cells in vitro. Moreover, GH3 tumors had fewer irrigating vessels, lower vascular area and a higher VEGF/bFGF ratio that correlated with Hif1a expression, consistent with the tissue hypoxia and hemorrhage. These features were downregulated in their co-injected counterparts, which interestingly showed an increased deposition of collagens, glycoproteins and mucopolysaccharides extra-cellular matrix (EMC) components. Isolated TtT/GF injected cells did not generate tumors, but they developed fibrous masses characterized by collagen and high bFGF production. In conclusion, our results demonstrate that FSCs are dual regulators of pituitary tumor growth, with a mitogenic action on tumor cells but also a restrictive tumor effect on the cancer processes angiogenesis, hypoxia, and ECM remodeling.

GREM1 deficiency induced bone marrow adipose niche promotes B-cell acute lymphoblastic leukemia disease progression

Relapse and disease progression are the primary causes of treatment failure and subsequent mortality in children with B-cell acute lymphocytic leukemia (B-ALL). At diagnosis and during treatment, dyslipidemia and the bone marrow adipose microenvironment are commonly observed in pediatric leukemia. However, the intricate connection between these factors and disease progression remains largely unexplored. We found that abnormal triglyceride accumulation increased the risk of death. Further investigation into the adipogenic potential of BM-MSCs revealed a correlation between higher adipogenicity and elevated serum TG levels, which subsequently led to the rapid proliferation of leukemia cells and heightened the risk of post-relapse mortality. Through RNA sequencing, Gremlin1 (GREM1) was identified as an important factor affecting adipogenicity. Silencing of GREM1 in BM-MSCs induced adipogenic differentiation, partly through the BMP/SMAD signaling pathway. In an in vitro co-culture model, shGREM1-MSCs promoted B-ALL cell proliferation and induced drug resistance to dexamethasone, while increasing sensitivity to L-asparaginase. Furthermore, GREM1-deficient BM-MSCs promoted B-ALL disease progression in xenograft models. This study provides new insights into overcoming drug resistance, relapse, and death by elucidating the novel mechanism by which GREM1 deficiency induces adipogenic differentiation of BM-MSCs and promotes B-ALL disease progression.

Meat and fish consumption, genetic risk and risk of severe metabolic-associated fatty liver disease: a prospective cohort of 487,875 individuals

BACKGROUND

Diet, specifically meat consumption, has been implicated as a modifiable risk factor in the development of metabolic-associated fatty liver disease (MAFLD). This study aimed to investigate the associations between various types of meat intake and the risk of severe MAFLD and to examine whether genetic risk influences these associations.

METHODS

This research utilized data from the UK Biobank, which initially enrolled over 500,000 participants between 2006 and 2010, of whom 487,875 were eligible for our analyses. Meat intake, including unprocessed red meat, processed meat, poultry, and fish, was evaluated through a validated touchscreen questionnaire. Cox proportional hazards models were used to analyze the relationship between meat consumption and severe MAFLD risk, adjusting for potential confounders. Genetic risk scores (GRS) were calculated using five MAFLD-associated SNPs, allowing for analyses of gene-diet interactions.

RESULTS

During a follow-up period totaling 6,036,554 person-years (mean duration: 12.1 years), 5,731 new cases of severe MAFLD were identified. High intakes of total meat, processed meat, unprocessed red meat and poultry were associated with increased MAFLD risk, with adjusted hazard ratios (HR) of 1.76 (95% CI: 1.33-2.33), 1.19 (1.02-1.40), 1.34 (1.17-1.53), and 1.21 (0.98-1.49), respectively, for the highest versus lowest intake categories. In contrast, oily fish intake showed a protective association (HR: 0.72; 95% CI: 0.53-0.97). No significant interaction was observed between meat intake and GRS for any meat subtype, suggesting that the associations were independent of genetic predisposition.

CONCLUSIONS

High consumption of red and processed meat was associated with an increased risk of severe MAFLD, while oily fish intake showed an inverse association with the risk of MAFLD. These effects were consistent across genetic risk levels for MAFLD. Our findings reinforce dietary recommendations to limit red and processed meat and encourage oily fish intake for MAFLD prevention, irrespective of individual genetic risk.

Obesity: pathophysiology and therapeutic interventions

Over the past few decades, obesity has transitioned from a localized health concern to a pressing global public health crisis affecting over 650 million adults globally, as documented by WHO epidemiological surveys. As a chronic metabolic disorder characterized by pathological adipose tissue expansion, chronic inflammation, and neuroendocrine dysregulation that disrupts systemic homeostasis and impairs physiological functions, obesity is rarely an isolated condition; rather, it is frequently complicated by severe comorbidities that collectively elevate mortality risks. Despite advances in nutritional science and public health initiatives, sustained weight management success rates and prevention in obesity remain limited, underscoring its recognition as a multifactorial disease influenced by genetic, environmental, and behavioral determinants. Notably, the escalating prevalence of obesity and its earlier onset in younger populations have intensified the urgency to develop novel therapeutic agents that simultaneously ensure efficacy and safety. This review aims to elucidate the pathophysiological mechanisms underlying obesity, analyze its major complications-including type 2 diabetes mellitus (T2DM), cardiovascular diseases (CVD), non-alcoholic fatty liver disease (NAFLD), obesity-related respiratory disorders, obesity-related nephropathy (ORN), musculoskeletal impairments, malignancies, and psychological comorbidities-and critically evaluate current anti-obesity strategies. Particular emphasis is placed on emerging pharmacological interventions, exemplified by plant-derived natural compounds such as berberine (BBR), with a focus on their molecular mechanisms, clinical efficacy, and therapeutic advantages. By integrating mechanistic insights with clinical evidence, this review seeks to provide innovative perspectives for developing safe, accessible, and effective obesity treatments.

Single-nucleus RNA sequencing defines adipose tissue subpopulations that contribute to Tibetan pig cold adaptation

BACKGROUND

Thermogenic beige adipocyte displays a remarkable ability in mammals to adapt to cold environments, but the underlying cellular mechanisms remain unclear, especially in pigs that lack functional UCP1.

RESULTS

Multilocular beige adipocytes were observed in both Tibetan pigs (cold-tolerant) and Bama pigs (cold-sensitive) after short-term cold exposure (4 ℃ for 3 days). Through single-nucleus RNA sequencing of adipose tissues, including subcutaneous inguinal adipose tissues (IAT) and perirenal adipose tissues (PAT), from both pig breeds at room temperature and cold treatment conditions, we discovered two cell subpopulations specific to Tibetan pigs, PDGFRα+EBF2High in IAT and ADIPOQ+HIF1AHigh in both depots. PDGFRα+EBF2High cells were characterized as potential beige precursors, while ADIPOQ+HIF1AHigh cells were found to express highly thermogenic-related genes. Despite the decrease of the lipogenic subpopulation and the increase of the lipolytic and the thermogenic subpopulations observed in both pig breeds upon cold treatment, Tibetan pigs exhibited stronger cellular and molecular responses compared to Bama pigs. Remarkably, cold-induced de novo beige adipogenesis and white adipocyte browning, likely occurred in Tibetan pigs, while Bama pigs relied more heavily on white browning. Moreover, BMP7, which was highly expressed in the PDGFRα+EBF2High subpopulation, positively regulates porcine beige thermogenic capacity.

CONCLUSIONS

Our data offers a comprehensive and unprecedented perspective on the heterogeneity and plasticity of adipose tissues of pigs and broadens the understanding of beige fat biology in mammals.

Keto Acids Attenuate Skeletal Muscle Atrophy in Chronic Kidney Disease via Inhibiting Pyroptosis and Upregulating Irisin Precursor FNDC5 Expression

It is widely accepted that keto acids supplementation can protect skeletal muscle from atrophy. Pyroptosis has been considered to be one of the new mechanisms of muscle atrophy. This study aimed to explore the effects and mechanisms of keto acids supplementation on chronic kidney disease (CKD)-induced skeletal muscle atrophy. In vitro, C2C12 myoblast cells were treated with indoxyl sulfate (IS, 1 mM) and leucine (Leu, 0 ng/mL, 50 ng/mL or 100 ng/mL). In animal experiment, animals were divided into four groups: normal control (NC) group (wildtype mice), CKD group (wildtype mice with CKD modeling), keto acids (KAs) group (CKD wildtype mice treated with KA), and FNDC5-/- group (Fndc5 (irisin precursor) gene knockout mice with CKD modeling and KA treatment). Results showed that leucine improved IS-induced myotube atrophy, decreased percentage of Propidium Iodide (PI)-positive cells, upregulated FNDC5 expression levels, and downregulated the pyroptosis-related protein levels, such as NLRP3, cleaved CASP1, and GSDMD-N. KA supplementation improved renal function and skeletal muscle atrophy. Furthermore, KA supplementation suppressed the expression of pyroptosis-related proteins and increased the expression of FNDC5. However, Fndc5 gene knockout partially reversed the protective effects of keto acids in CKD. In conclusion, our results showed for the first time that KA supplementation improves CKD-induced skeletal muscle atrophy by inhibiting pyroptosis and increasing expression of irisin/FNDC5. Our findings provide a novel insight into the treatment of the CKD-induced skeletal muscle atrophy.

NOTCH Signaling Networks in Perivascular Adipose Tissue

Over a hundred years ago, mutants were detected in Drosophila melanogaster that led to a NOTCH in the wing tip. This original phenotype was reflected in the nomenclature of the gene family that was later cloned and characterized in the 1980s and found to be conserved across metazoans. NOTCH signaling relies on transmembrane ligands and receptors that require cellular contact for receptor activation, reflecting its role in multicellular organisms as an intercellular signaling strategy. In humans, mutations in genes encoding NOTCH and their ligands have been shown to promote human disease; these aspects have been extensively reviewed. Notch signaling plays important roles in vascular development (vasculogenesis and angiogenesis) and homeostasis. NOTCH signaling is also active in adipose tissue and contributes to adipocyte differentiation. In addition, NOTCH activity regulates functions of other metabolic organs. This review focuses on NOTCH activity in perivascular adipose tissue within the vascular microenvironment as defined by mouse studies and summarizes expression and potential signaling of the NOTCH signaling network in human perivascular adipose tissue. Due to the strong activity of NOTCH in regulation of metabolic function, activation of the NOTCH network in specific cell types in perivascular adipose tissue has implications for signaling to the underlying blood vessel and control of vascular health and disease.

Using chanarin-dorfman syndrome patient fibroblasts to explore disease mechanisms and new treatment avenues

BACKGROUND

Chanarin-Dorfman syndrome (CDS) is a multisystemic autosomal recessive rare disorder. CDS is caused by variants in the abhydrolase domain containing 5 (ABHD5) encoding gene (CGI-58), which ultimately leads to excessive lipid storage, and therefore a high abundance of cellular lipid droplets (LDs). Although the molecular etiology of the disease was described many years ago, no treatment for CDS is currently available.

RESULTS

To further characterize the molecular basis of the disease and to uncover new treatment avenues, we used skin fibroblasts originating from a young patient diagnosed with CDS due to a homozygous nonsense mutation. We show that dysfunctional ABHD5 does not only affect LDs, but also influences other metabolic-related organelles; the mitochondria and peroxisomes. Additionally, we found that expressing functional ABHD5 in CDS patient cells reduced LD number. Finally, we developed and applied a high content-based drug repurposing screen based on a collection of ∼2500 FDA approved compounds, yielding several compounds that affected LD total area and size.

CONCLUSIONS

Our findings enhance the understanding of the dysfunction underlying CDS and propose new avenues for the treatment of CDS patients.

Secreted spermidine synthase reveals a paracrine role for PGC1α-induced growth suppression in prostate cancer

Prostate cancer is the fifth cause of death by cancer worldwide, second in incidence in the male population. The definition of the molecular basis of its development and the oncogenic signals driving lethality continue to be important objectives in prostate cancer research. Prior work from others and us has demonstrated that loss of PGC1α expression results in a metabolic, signaling and transcriptional reprogramming that supports the development of metastatic disease. However, we do not fully understand the spectrum of tumor suppressive effects regulated by this co-regulator. Here we show that PGC1α governs non-cell autonomous paracrine tumor suppression in prostate cancer. A systematic analysis of the transcriptional landscapes associated to PGC1α loss of expression revealed that PGC1α alters the expression of genes encoding for secreted proteins. Cell secretome studies corroborated that PGC1α-dependent ERRα regulation in prostate cancer cells suppresses the growth of tumor cells exposed to their conditioned media, independently of androgen receptor status. The integration of in vitro and in vivo secretomics data and genetic perturbation assays revealed spermidine synthase as a transcriptional target of PGC1α and mediator of the paracrine metabolic growth suppressive effect. Moreover, the activity of the regulatory axis PGC1α-ERRα-SRM was reflected in patients and had prognostic value. Altogether, this work provides unprecedented evidence of the non-cell autonomous suppressive role of PGC1α, which broadens the view of this co-regulator as a multifactorial tumor suppressor in prostate cancer.

TNF-α/NF-κB mediated upregulation of Dectin-1 in hyperglycemic obesity: implications for metabolic inflammation and diabetes

BACKGROUND

Dectin-1, a key innate immune receptor, plays a critical role in cellular responses and is implicated in chronic inflammation and metabolic syndromes. This study addresses a pivotal gap in elucidating the regulatory mechanism governing Dectin-1 expressionin obesity and diabetes, hypothesizing that hyperglycemia and TNF-α synergistically upregulate Dectin-1 in adipose tissue (AT), thereby exacerbating inflammatory responses and contributing to metabolic dysfunction.

METHODS

The study included 95 overweight and obese Kuwaiti individuals, categorized into prediabetic (HbA1c < 6.5%) and diabetic (HbA1c ≥ 6.5%) groups. Anthropometric and clinical measurements were recorded. AT biopsies were obtained for RNA extraction and immunohistochemistry. Pre-adipocytes from lean and obese individuals were cultured, differentiated into adipocytes, and treated with TNF-α under normal or high-glucose conditions to assess Dectin-1 expression. Chromatin immunoprecipitation (ChIP) assays analyzed NF-κB binding to the Dectin-1 promoter. Wildtype and TNF-α-/- mice were used to evaluate TNF-α's effect on Dectin-1 expression in AT.

RESULTS

Our data demonstrate that hyperglycemic obesity significantly induces Dectin-1 expression in AT through the TNF-α/NF-κB signaling pathway. In a cohort of 95 obese individuals, subdivided into prediabetics (HbA1c < 6.5%, n = 49) and diabetics (HbA1c ≥ 6.5%, n = 46), a strong positive correlation was observed between AT Dectin-1 transcripts and plasma HbA1c levels exclusively in diabetic participants, underscoring the specificity of Dectin-1 upregulation in hyperglycemic conditions. Elevated Dectin-1 expression was consistently associated to increased inflammation markers. Immunohistochemical analysis revealed co-localization and concurrent upregulation of Dectin-1 and TNF-α proteins in hyperglycemic AT. Functional assays in TNF-α deficient mice and human adipocytes further validated that TNF-α and hyperglycemia act cooperatively to regulate Dectin-1 expression. Mechanistically, we demonstrated that NF-κB directly binds to the Dectin-1 promoter, mediating its transcriptional activation in response to glucose and TNF-α.

CONCLUSION

This study significantly advances the understanding of upregulation Dectin-1 in metabolic inflammation, filling a crucial niche in diabetes research and suggesting new therapeutic targets for obesity-related metabolic disorders.

β-Cell Dedifferentiation in HOMA-βlow and HOMA-βhigh Subjects

CONTEXT

β-Cell dedifferentiation ratio is increased in type 2 diabetes; but its direct link to in vivo β-cell function in human remains unclear.

OBJECTIVE

The present study was designed to investigate whether β-cell dedifferentiation in situ was closely associated with β-cell function in vivo and to identify targets crucial for β-cell dedifferentiation/function in human.

METHODS

We acquired homeostasis model assessment of β-cell function (HOMA-β) values, calculated the number of hormone-negative endocrine cells, and evaluated important markers and novel candidates for β-cell dedifferentiation/function on paraneoplastic pancreatic tissues from 13 patients with benign pancreatic cystic neoplasm or intrapancreatic accessory spleen.

RESULTS

Both the β-cell dedifferentiation ratio and the dedifferentiation marker (Aldh1a3) were inversely related to in vivo β-cell function (HOMA-β) and in situ β-cell functional markers Glut2 and Ucn3 in humans. Moreover, the islets from HOMA-βlow subjects were manifested as (1) increased β-cell dedifferentiation ratio, (2) enriched dedifferentiation maker Aldh1a3, and (3) lower expression of Glut2 and Ucn3 compared with those from HOMA-βhigh subjects. We found that basic leucine zipper transcription factor 2 (Bach2) expression was significantly induced in islets from HOMA-βlow patients and was positively correlated with the ratio of β-cell dedifferentiation in humans.

CONCLUSION

Our findings emphasize the contribution of β-cell dedifferentiation to β-cell dysfunction in humans. Bach2 induction in β-cells with higher frequency of dedifferentiation observed in HOMA-βlow subjects reinforces its distinctive role as a pharmaceutical target of β-cell dedifferentiation for the treatment of people with diabetes.

Sleep Duration Alters Overfeeding-mediated Reduction in Insulin Sensitivity

CONTEXT

Weight gain and sleep restriction both reduce insulin sensitivity. However, it is not known if sleep duration alters glucose metabolism in response to overfeeding.

OBJECTIVE

To examine the effect of sleep duration on overfeeding-mediated alterations in carbohydrate metabolism and insulin sensitivity.

METHODS

Retrospective exploratory analysis of a longitudinal overfeeding study in healthy participants (n = 28, age: 26.9 ± 5.5 years, body mass index: 25.74 ± 2.45 kg/m2). After providing baseline study measures, participants were overfed 40% above weight maintenance calorie requirements for 8 weeks. Insulin sensitivity was determined by a 2-step hyperinsulinemic-euglycemic clamp. Baseline habitual sleep duration was estimated by accelerometry, and sleep groups were created based on median sleep duration (5.2 hours/night).

RESULTS

Overfeeding led to an average body weight gain of 7.3 ± .4 kg. Habitual sleep duration did not alter overfeeding-mediated body weight gain, fat gain, and fat distribution (all P > .15). Compared to participants with more sleep, fasting insulin (P = .01) and homeostatic model assessment for insulin resistance (P = .02) increased while fasting glucose remained unchanged (P = .68) with overfeeding in participants with shorter sleep duration. Glucose infusion rate during high insulin dose was reduced with overfeeding in participants with short sleep duration but not in participants with more sleep (P < .01).

CONCLUSION

Overfeeding mediated weight gain reduced liver, adipose, and whole-body insulin sensitivity prominently in individuals with short sleep duration but not in individuals with longer sleep duration. This suggests that promoting adequate sleep during short periods of overeating may prevent detrimental effects on glucose metabolism.

Weight Gain With Advancing Age Is Controlled by the Muscarinic Acetylcholine Receptor M4 in Male Mice

Obesity is characterized by the excessive accumulation of adipose tissue, and it is a serious global health issue. Understanding the pathology of obesity is crucial for developing effective interventions. In this study, we investigated the role of muscarinic acetylcholine receptor M4 (mAChR-M4) in the regulation of obesity in Chrm4-knockout (M4-KO) mice. Male M4-KO mice showed higher weight gain and accumulation of white adipose tissue (WAT) with advancing age than the wild-type mice. The M4-KO mice also showed increased leptin expression at both the transcription and the translation levels. RNA sequencing and quantitative reverse transcription polymerase chain reaction analyses of subcutaneous adipose tissues revealed that the expression of WAT marker genes was significantly enhanced in the M4-KO mice. In contrast, the expression levels of brown adipose tissue/beige adipose tissue markers were strongly decreased in the M4-KO mice. To identify the Chrm4-expressing cell types, we generated Chrm4-mScarlet reporter mice and examined the localization of the mScarlet fluorescent signals in subcutaneous tissues. Fluorescent signals were prominently detected in WAT and mesenchymal stem cells. Additionally, we also found that choline acetyltransferase was expressed in macrophages, suggesting their involvement in acetylcholine (ACh) secretion. Corroborating this notion, we were able to quantitatively measure the ACh in subcutaneous tissues by liquid chromatography tandem mass spectrometry. Collectively, our findings suggest that endogenous ACh released from macrophages maintains the homeostasis of adipose cell growth and differentiation via mAChR-M4 in male mice. This study provides new insights into the molecular mechanisms underlying obesity and potential targets for therapeutic interventions.

Rethinking fat Browning: Uncovering new molecular insights into the synergistic roles of fasting, exercise, and cold exposure

The global obesity epidemic highlights the need to understand the molecular mechanisms that regulate energy metabolism. Among emerging research areas, fat browning-the transformation of white adipose tissue into beige fat-has gained significant attention. This review explores the molecular pathways involved in fat browning triggered by fasting, physical exercise, and cold exposure, emphasizing both shared and distinct regulatory mechanisms. These stimuli consistently induce physiological responses such as lipolysis, mitochondrial biogenesis, and improved insulin sensitivity. Notably, PGC-1α and SIRT3 are upregulated across all three conditions, underscoring their central roles in mitochondrial function and energy metabolism and identifying them as promising therapeutic targets. In contrast, UCP1 and PRDM16 exhibit condition-specific regulation, suggesting they may not be universally essential for fat browning. In addition, the review discusses species-specific differences in brown adipose tissue (BAT) activation, particularly between rodents and humans, highlighting the challenges of translating animal model findings to human therapies. Future research should aim to develop selective pharmacological activators of PGC-1α and SIRT3 to enhance therapeutic outcomes while minimizing adverse effects. This review also proposes that integrating fasting, exercise, and cold exposure could provide innovative strategies to promote metabolic health.

Brown fat thermogenesis and cold adaptation in humans

Brown adipose tissue (BAT) is a site of non-shivering thermogenesis (NST) in mammals. Since the rediscovery of BAT in adult humans, there has been a remarkable advance in human BAT researches, revealing the significant roles of this thermogenic tissue in cold-induced NST and cold adaptation. Cold stress influences BAT in various time spans: acute cold exposure promptly activates BAT to induce NST, which contributes to immediate maintenance of body temperature. Prolonged cold exposure recruits BAT, resulting in increased capacity of NST and improved cold tolerance. Such BAT adaptation not only occurs in the exposed individual but also is passed on to the next generation, probably via the paternal lineage. As such, BAT plays a role in acute, chronic, and transgenerational adaptation to cold environment in humans.

Effects of Quercetin Metabolites on Glucose-Dependent Lipid Accumulation in 3T3-L1 Adipocytes

The aim of the study was to assess the effects of quercetin metabolites (QMs) on lipid accumulation in adipocytes under high-glucose and physiological-glucose concentrations and to elucidate the mechanisms involved. 3T3-L1 mature adipocytes were exposed to a physiological glucose concentration, as a model of caloric restriction (CR), or high glucose (control), with and without QMs (quercetin-3-glucuronide [Q3G] and isorhamnetin [ISOR]). Cells were treated with Q3G (0.3 and 0.6 µmol/L) and ISOR (0.2 and 0.4 µmol/L) for 48 h. Lipid accumulation (Oil Red O staining) and Δ glucose level (HPLC) were assessed. Under high glucose, Q3G and ISOR reduced lipid accumulation (-10.8% and -10.4%; p < 0.01) and Δ glucose level (-13.6% and -14.2%; p < 0.05). Under CR, QMs increased Δ glucose level (+21.6% for Q3G and +21% for ISOR; p < 0.05). ISOR increased pAMPK levels under high glucose (+1.4-fold; p < 0.05). Under CR, Q3G and ISOR increased pAMPK (+1.4- and +1.5-fold; p < 0.05), while ISOR upregulated SIRT1 and PGC-1α (+2.3- and +1.5-fold; p < 0.05). Findings support, for the first time, the potential contribution of QMs, especially ISOR, in the regulation of lipid metabolism in vitro, possibly via AMPK activation. Further studies, including in vivo, are encouraged to strengthen evidence of the mechanisms observed.

Canagliflozin potentially promotes renal protection against glycerol-induced acute kidney injury by activating the AMPK/SIRT1/FOXO-3a/PGC-1α and Nrf2/HO-1 pathways

The reno-protective potential of canagliflozin (Cana), an inhibitor of the sodium glucose-linked co-transporter-2 (SGLT-2), has been demonstrated in different models of kidney injury. However, its potential role in preventing glycerol (Gly)-induced acute kidney injury (AKI) remains to be divulged. Therefore, the aim of this study is to investigate the potential reno-protective effect of Cana and its underlying mechanism in a rat model of Gly-induced AKI. Rats were randomly allocated into five groups: normal, Gly, Gly pretreated with 10 mg/kg Cana, Gly pretreated with Cana 25 mg/kg, and normal pretreated with Cana 25 mg/kg for 14 consecutive days. Pretreatment with Cana improved renal structure and enhanced kidney functions manifested by reducing serum creatinine and blood urea nitrogen, as well as renal contents of neutrophil gelatinase-associated lipocalin and kidney injury molecule. Moreover, Cana signified its anti-inflammatory effect by reducing the Gly-induced elevation in renal contents of nuclear factor-κB and interleuκin-6. Additionally, Cana augmented the defense enzymatic antioxidants superoxide dismutase (SOD), manganese-SOD, and heme oxygenase-1, besides increasing the protein expression of the antioxidant transcription factor nuclear factor erythroid 2-related factor 2 to point for its ability to correct redox balance. Cana also upregulated the protein expression of the 5' adenosine monophosphate-activated protein kinase (AMPK), Sirtuin1 (SIRT1), Forkhead box protein O3 (FOXO-3a), and peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC-1α), as well as the transcriptional activity of growth arrest and DNA damage-inducible protein alpha (GAAD45a). In conclusion, Cana demonstrated potentially novel reno-protective mechanisms and mitigated the consequences of AKI through its antioxidant and anti-inflammatory properties, partially by activating the AMPK/SIRT1/FOXO-3a/PGC-1α pathway.

Royal jelly reduced non-rapid eye movement sleep fragmentation and restored sleep stability in diet-induced obese mice

Royal jelly (RJ) is recognized due to its high nutritional value and potential health benefits. Previous research showed that RJ supplementation decreased fat accumulation, resulting in weight loss and improvements in hyperglycemia and insulin resistance in high-fat diet (HFD)-induced obese mice. To expand the weight-reducing properties of RJ, this study aimed to investigate the effects of RJ supplementation on HFD-induced obese mice with impaired sleep stabilization. Over a 20-week period, the C57BL/6J mice were divided into the following dietary groups: normal diet (ND), ND supplemented with 5% lyophilized RJ powder (ND+RJ), HFD, and HFD supplemented with 5% lyophilized RJ powder (HFD+RJ) groups. Compared with the HFD group, the HFD+RJ group exhibited a significant reduction in body weight via a decrease in fat mass. Moreover, much like the ND group, the HFD+RJ group demonstrated improvements in the fragmentation of non-rapid eye movement (NREM) sleep and wakefulness. These processes contributed to the reestablishment of sleep/wake continuity and restored the overall stability of sleep. In contrast, the ND+RJ and ND groups exhibited a similar sleep/wake architecture. Thus, RJ supplementation in the ND demonstrated no substantial effect on sleep/wake. According to these findings, dietary RJ improves the sleep/wake architecture and restores sleep stability. Hence, RJ is a promising dietary component for addressing obesity and restoring sleep stability.