ATP11B Modulates Microglial Lipid Metabolism and Alleviates Alzheimer's Disease Pathology

Abnormal lipid metabolism in microglia leads to the formation of pathological lipid droplets (LDs), a phenomenon also observed in neurodegenerative diseases such as Alzheimer's disease (AD). The abnormal accumulation of LDs disrupts normal cellular function and exacerbates the pathological process of AD. ATP11B is a P4-ATPase and the expression of Atp11b changes in the brain of patients with AD and diseases of lipid metabolism. The present study aimed to explore the regulatory role of ATP11B in microglial lipid metabolism and assess the potential of ATP11B as a therapeutic target for AD. Atp11b deficiency caused excessive fatty acid uptake and activated the PPAR signaling pathway, resulting in abnormal synthesis of neutral lipids and mitochondrial energy metabolism in microglia. Further results showed that Atp11b deficiency led to the accumulation of pathological LDs in microglia and AD mice. Conversely, overexpression of Atp11b alleviated exploratory behavior impairment, learning and memory impairment, LD accumulation, beta-amyloid (Aβ) deposition, and inflammatory response in the brain of AD mice. These findings provide important clues for a better understanding of the pathogenesis of AD and for developing novel therapeutic strategies.

Nutrigenetic and Epigenetic Mechanisms of Maternal Nutrition-Induced Glucolipid Metabolism Changes in the Offspring

Maternal nutrition during pregnancy regulates the offspring's metabolic homeostasis, including insulin sensitivity and the metabolism of glucose and lipids. The fetus undergoes a crucial period of plasticity in the uterus; metabolic changes in the fetus during pregnancy caused by maternal nutrition not only influence fetal growth and development but also have a long-term or even life-long impact for the offspring. Epigenetic modifications, such as DNA methylation, histone modification, and non-coding RNAs, play important roles in intergenerational and transgenerational effects. In this context, this narrative review comprehensively summarizes and analyzes the molecular mechanisms underlying how maternal nutrition, including a high-fat diet, polyunsaturated fatty acid diet, methyl donor nutrient supplementation, feed restriction, and protein restriction during pregnancy, impacts the genes involved in glucolipid metabolism in the liver, adipose tissue, hypothalamus, muscle, and oocytes of the offspring in terms of the epigenetic modifications. This will provide a foundation for the further exploration of nutrigenetic and epigenetic mechanisms for integrative mother-child nutrition and promotion of the offspring's health through the regulation of maternal nutrition during pregnancy. Note: This paper is part of the Nutrition Reviews Special Collection on Precision Nutrition.

The role of adipogenic niche resident cells in colorectal cancer progression in relation to obesity

Colorectal cancer (CRC) is the third most common cancer worldwide and has one of the highest mortality rates. Considering its nonlinear etiology, many risk factors are associated with CRC formation and development, with obesity at the forefront. Obesity is regarded as one of the key environmental risk determinants for the pathogenesis of CRC. Excessive food intake and a sedentary lifestyle, together with genetic predispositions, lead to the overgrowth of adipose tissue along with a disruption in the number and function of its building cells. Adipose tissue-resident cells may constitute part of the CRC microenvironment. Alterations in their physiology and secretory profiles observed in obesity may further contribute to CRC progression, and despite similar localization, their contributions are not equivalent. They can interact with CRC cells, either directly or indirectly, influencing various processes that contribute to tumorigenesis. The main aim of this review is to provide insights into the diversity of adipose tissue resident cells, namely, adipocytes, adipose stromal cells, and immunological cells, regarding the role of particular cell types in co-forming the CRC microenvironment. The scope of this study was also devoted to the abnormalities in adipose tissue physiology observed in obesity states and their impact on CRC development.

Antioxidant and Anti-Inflammatory Defenses in Huntington's Disease: Roles of NRF2 and PGC-1α, and Therapeutic Strategies

Huntington's disease (HD) is a detrimental neurodegenerative disease caused by the expansion of a CAG triplet in the HTT gene. This mutation leads to the production of mutant Huntingtin (Htt) protein with toxic gain-of-function. The mHtt is responsible in several ways for the establishment of an intricate pathogenetic scenario in affected cells, particularly in HD neurons. Among the features of HD, oxidative stress plays a relevant role in the progression of the disease at the cellular level. Mitochondrial dysfunction, bioenergetic deficits, Reactive Oxygen Species (ROS) production, neuroinflammation, and general reduction of antioxidant levels are all involved in the promotion of a toxic oxidative environment, eventually causing cell death. Nonetheless, neuronal cells exert antioxidant molecules to build up defense mechanisms. Key components of these defensive mechanisms are the nuclear factor erythroid 2-related factor 2 (NRF2) and peroxisome proliferator-activated receptor gamma coactivator-1 α (PGC-1α). Thus, this review aims to describe the involvement of oxidative stress in HD by exploring the roles of NRF2 and PGC-1α, crucial actors in this play. Finally, antioxidant therapeutic strategies targeting such markers are discussed.

The importance of thiamine availability in the thermogenic competency of human adipocytes

Brown and beige adipocytes express uncoupling protein 1 (UCP1), which is located in the inner mitochondrial membrane and facilitates the dissipation of excess energy as heat. The activation of thermogenic adipocytes is a potential therapeutic target for treating type 2 diabetes mellitus, obesity, and related co-morbidities. Therefore, identifying novel approaches to stimulate the function of these adipocytes is crucial for advancing therapeutic strategies. Currently, there are limited amount of human adipocyte cell line models available to study the regulatory mechanisms of browning and key players in thermogenesis. The Simpson-Golabi-Behmel syndrome (SGBS) preadipocyte cell line has been proven as a valuable model to investigate human adipocyte biology. In this study, we investigated how excess thiamine (vitamin B1), and the inhibition of thiamine transporters affect the expression of thermogenic markers and functional parameters during adrenergic stimulation in SGBS adipocytes. We found that limiting thiamine availability by pharmacological inhibitors impeded the dibutyryl-cAMP (db-cAMP)-dependent induction of thiamine transporter 1 and 2 (encoded by SLC19A2 and SLC19A3), UCP1, PGC1a, and other browning markers, as well as proton leak respiration which is associated with UCP1-dependent heat generation. Contrarily, excess thiamine enhanced the db-cAMP-dependent induction of thiamine transporters, while UCP1, PGC1a, and other browning markers were upregulated. In addition, abundant amounts of thiamine increased the basal, unstimulated coupled and uncoupled respiration, and the expression of mitochondrial complex subunits. Our study highlights the critical role of excess thiamine in the thermogenic activation of SGBS adipocytes and its potential to enhance thermogenesis.

Myokines and interorgan crosstalk: bridging exercise to health promotion and disease prevention

Exercise is known to promote physical health and reduce the risk of various diseases. During exercise, skeletal muscle actively contracts to perform movements and secretes hormone-like molecules termed myokines. The beneficial effects of exercise have been assessed with respect to myokine production, and those of irisin on bone, adipose tissue, and the brain have been well documented. Irisin, through its interactions with the integrin αV family, plays a crucial role in bone maintenance, metabolic regulation, and cognitive function. Building on the established understanding of irisin, this discussion will examine the functions and effects of other myokines as key secretory factors in exercise, emphasizing their broader roles in health promotion and the potential for new therapeutic strategies in disease prevention and treatment.

The Complex Interplay of Irisin Levels, Low Birth Weight, and Blood Pressure in Prepubescent Children

BACKGROUND

Irisin regulates various metabolic, inflammatory, and oxidative stress processes. It has been considered a promising target in the context of the development and maintenance of cardiovascular diseases. We conducted a study to evaluate the levels of plasma irisin in prepubertal children, examining its relationship with birth weight, anthropometric parameters, biochemical profile, and blood pressure levels.

METHODS

A cross-sectional study was conducted involving 136 prepubertal children aged 6 to 11 years, with 27.9% born at a low weight. Anthropometric parameters, blood pressure, and biochemical profiles were assessed.

RESULTS

Children with low birth weight had significantly lower irisin levels compared to those with normal birth weight (p < 0.001). Birth weight was negatively correlated with blood pressure levels (systolic: r = -0.213, p = 0.013; diastolic: r = -0.223, p = 0.009) and positively correlated with irisin levels (p < 0.001). Irisin levels were positively associated with systolic blood pressure, even after adjusting for birth weight, BMI, and physical activity (p < 0.001). The linear regression analysis indicated that low birth weight and high plasma levels of irisin were recognized as predictive factors of elevated blood pressure levels.

CONCLUSION

The positive correlation observed between circulating irisin and systolic blood pressure levels in children with low birth weight, despite their lower irisin levels, suggests a complex interplay between birth weight, irisin, cardiovascular regulation, and metabolic function. Understanding this relationship may require considering that irisin may play dual roles in different tissues, compensatory mechanisms, and the broader context of cardiometabolic programming in children with low birth weight.

Live yeast (Saccharomyces cerevisiae) improves growth performance and liver metabolic status of lactating Hu sheep

Yeast, a natural starter culture, is widely used to improve digestion function in ruminants. However, whether yeast affects the physiological state of the liver in ruminants is currently unknown. The aim of this study was to investigate the effects of yeast on liver metabolic status and physiological functions of Hu sheep during lactation. A total of 24 lactating Hu sheep were randomly divided into 4 groups with 6 sheep in each group: the control group (normal diet) and the low-, medium-, and high-dose groups, in which each sheep was fed an additional 0.5 g, 1 g, and 2 g yeast per morning, respectively. Blood, liver, small intestine samples were collected for subsequent analysis, and milk production and BW were recorded during the experimental period. The results showed that dietary yeast supplementation mitigated BW loss, enhanced liver function, and increased milk protein and lactose contents in Hu sheep during lactation. Compared with the normal diet, dietary yeast supplementation reduced the content of lipid droplets in the liver, significantly upregulated the expression of lipid β-oxidation-related enzymes (PPARA and CPT1A), and significantly decreased the expression of lipid synthesis-related enzymes (FASN, PPARγ, DGAT1, and DGAT2) in the liver without affecting the capacity of the small intestine to absorb foodborne lipids. In addition, dietary yeast supplementation significantly decreased blood nonesterified free fatty acid content and increased blood glucose and liver expression of key enzymes involved in gluconeogenesis (PCK1α, FBP, and G6PC). These results suggest that dietary yeast supplementation may alleviate weight loss and enhance milk quality in Hu sheep during lactation. Furthermore, it can improve liver metabolic adaptability and protect liver health by regulating lipid metabolism and metabolic glucose homeostasis in the liver. Notably, adding 1 g or 2 g of yeast to the daily diet yields superior effects.

Lipid metabolism, remodelling and intercellular transfer in the CNS

Lipid metabolism encompasses the catabolism and anabolism of lipids, and is fundamental for the maintenance of cellular homeostasis, particularly within the lipid-rich CNS. Increasing evidence further underscores the importance of lipid remodelling and transfer within and between glial cells and neurons as key orchestrators of CNS lipid homeostasis. In this Review, we summarize and discuss the complex landscape of processes involved in lipid metabolism, remodelling and intercellular transfer in the CNS. Highlighted are key pathways, including those mediating lipid (and lipid droplet) biogenesis and breakdown, lipid oxidation and phospholipid metabolism, as well as cell-cell lipid transfer mediated via lipoproteins, extracellular vesicles and tunnelling nanotubes. We further explore how the dysregulation of these pathways contributes to the onset and progression of neurodegenerative diseases, and examine the homeostatic and pathogenic impacts of environment, diet and lifestyle on CNS lipid metabolism.

The Role of Exerkines in the Treatment of Knee Osteoarthritis: From Mechanisms to Exercise Strategies

With the increasing prevalence of knee osteoarthritis (KOA), the limitations of traditional treatments, such as their limited efficacy in halting disease progression and their potential side effects, are becoming more evident. This situation has prompted scientists to seek more effective strategies. In recent years, exercise therapy has gained prominence in KOA treatment due to its safety, efficacy, and cost-effectiveness, which are underpinned by the molecular actions of exerkines. Unlike conventional therapies, exerkines offer specific advantages by targeting inflammatory responses, enhancing chondrocyte proliferation, and slowing cartilage degradation at the molecular level. This review explores the potential mechanisms involved in and application prospects of exerkines in KOA treatment and provides a comprehensive analysis of their role. Studies show that appropriate exercise not only promotes overall health, but also positively impacts KOA by stimulating exerkine production. The effectiveness of exerkines, however, is influenced by exercise modality, intensity, and duration of exercise, making the development of personalized exercise plans crucial for KOA patients. Based on these insights, this paper proposes targeted exercise strategies designed to maximize exerkine benefits, aiming to provide novel perspectives for KOA prevention and treatment.

Cytokine response to resistance exercise in children with excess adiposity and Prader-Willi syndrome

Interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), and irisin (cytokines) are affected by excess body fat (obesity), skeletal muscle, and resistance exercise (RE). The purpose of this study is to determine whether Prader-Willi Syndrome (PWS), a genetic cause for obesity (OB), or non-syndromic OB influences these cytokine responses to RE. Nine children with PWS (11.4 ± 3.3 years, 45.6 ± 5.2% BF), 11 children without OB (9.2 ± 1.4 years, 18.6 ± 5.0% BF), and 12 children with OB (9.6 ± 1.3 years, 40.4 ± 5.4% BF) participated. Children stepped onto an elevated platform wearing a weighted vest for 6 sets of 10 repetitions per leg separated by 1 min of rest. Blood samples were obtained before exercise (pre), immediately post (IP), and during recovery (+15 and +60 min). There were no group-by-time interactions for any cytokine; and neither time nor group effects for TNF-α or irisin (p ≥ 0.378). For IL-6, 60+ was higher than pre, IP, and +15 (p < 0.001). Children with PWS and OB had increased IL-6 than children without OB (p ≤ 0.038). Neither PWS nor OB affected IL-6, TNF-α or irisin responses to RE. However, excess body fat was associated with higher IL-6 concentrations.

Subcutaneous adipose tissue and skeletal muscle mitochondria following weight loss

Obesity is a major global health issue with various metabolic complications. Both bariatric surgery and dieting achieve weight loss and improve whole-body metabolism, but vary in their ability to maintain these improvements over time. Adipose tissue and skeletal muscle metabolism are crucial in weight regulation, and obesity is linked to mitochondrial dysfunction in both tissues. The impact of bariatric surgery versus dieting on adipose tissue and skeletal muscle mitochondrial metabolism remains to be elucidated. Understanding the molecular pathways that modulate tissue metabolism following weight loss holds potential for identifying novel therapeutic targets in obesity management. This narrative review summarizes current knowledge on mitochondrial metabolism following bariatric surgery and diet-induced weight loss in adipose tissue and skeletal muscle, and sheds light on their respective effects.

Systemic aging fuels heart failure: Molecular mechanisms and therapeutic avenues

Systemic aging influences various physiological processes and contributes to structural and functional decline in cardiac tissue. These alterations include an increased incidence of left ventricular hypertrophy, a decline in left ventricular diastolic function, left atrial dilation, atrial fibrillation, myocardial fibrosis and cardiac amyloidosis, elevating susceptibility to chronic heart failure (HF) in the elderly. Age-related cardiac dysfunction stems from prolonged exposure to genomic, epigenetic, oxidative, autophagic, inflammatory and regenerative stresses, along with the accumulation of senescent cells. Concurrently, age-related structural and functional changes in the vascular system, attributed to endothelial dysfunction, arterial stiffness, impaired angiogenesis, oxidative stress and inflammation, impose additional strain on the heart. Dysregulated mechanosignalling and impaired nitric oxide signalling play critical roles in the age-related vascular dysfunction associated with HF. Metabolic aging drives intricate shifts in glucose and lipid metabolism, leading to insulin resistance, mitochondrial dysfunction and lipid accumulation within cardiomyocytes. These alterations contribute to cardiac hypertrophy, fibrosis and impaired contractility, ultimately propelling HF. Systemic low-grade chronic inflammation, in conjunction with the senescence-associated secretory phenotype, aggravates cardiac dysfunction with age by promoting immune cell infiltration into the myocardium, fostering HF. This is further exacerbated by age-related comorbidities like coronary artery disease (CAD), atherosclerosis, hypertension, obesity, diabetes and chronic kidney disease (CKD). CAD and atherosclerosis induce myocardial ischaemia and adverse remodelling, while hypertension contributes to cardiac hypertrophy and fibrosis. Obesity-associated insulin resistance, inflammation and dyslipidaemia create a profibrotic cardiac environment, whereas diabetes-related metabolic disturbances further impair cardiac function. CKD-related fluid overload, electrolyte imbalances and uraemic toxins exacerbate HF through systemic inflammation and neurohormonal renin-angiotensin-aldosterone system (RAAS) activation. Recognizing aging as a modifiable process has opened avenues to target systemic aging in HF through both lifestyle interventions and therapeutics. Exercise, known for its antioxidant effects, can partly reverse pathological cardiac remodelling in the elderly by countering processes linked to age-related chronic HF, such as mitochondrial dysfunction, inflammation, senescence and declining cardiomyocyte regeneration. Dietary interventions such as plant-based and ketogenic diets, caloric restriction and macronutrient supplementation are instrumental in maintaining energy balance, reducing adiposity and addressing micronutrient and macronutrient imbalances associated with age-related HF. Therapeutic advancements targeting systemic aging in HF are underway. Key approaches include senomorphics and senolytics to limit senescence, antioxidants targeting mitochondrial stress, anti-inflammatory drugs like interleukin (IL)-1β inhibitors, metabolic rejuvenators such as nicotinamide riboside, resveratrol and sirtuin (SIRT) activators and autophagy enhancers like metformin and sodium-glucose cotransporter 2 (SGLT2) inhibitors, all of which offer potential for preserving cardiac function and alleviating the age-related HF burden.

PAX translocations remodel mitochondrial metabolism through altered leucine usage in rhabdomyosarcoma

Alveolar rhabdomyosarcoma (ARMS) patients harboring paired-box fusion proteins (PAX3/7-FOXO1) exhibit a greater incidence of tumor relapse, metastasis, and poor survival outcome, thereby underscoring the urgent need to develop effective therapies to treat this subtype of childhood cancer. To uncover mechanisms that contribute to tumor initiation, we develop a muscle progenitor model and use epigenomic approaches to unravel genome rewiring events mediated by PAX3/7 fusion proteins. Among the key targets of PAX3/7 fusion proteins, we identify a cohort of oncogenes, fibroblast growth factor (FGF) receptors, tRNA-modifying enzymes, and genes essential for mitochondrial metabolism and protein translation, which we successfully targeted in preclinical trials. We identify leucine usage as a key factor driving the growth of aggressive PAX-fusion tumors, as limiting its bioavailability impaired oxidative phosphorylation and mitochondrial metabolism, delaying tumor progression and improving survival in vivo. Our data provide a compelling list of actionable targets and suggest promising new strategies to treat this tumor.

Intermittent cold stimulation acclimates broilers to acute cold stress by affecting cardiac lipid metabolism

OBJECTIVE

This study aimed to investigate whether intermittent cold stimulation can induce adaptation in broilers to acute cold stress (ACS) by regulating the lipid metabolism of hearts.

METHODS

CS0 were kept at normal rearing temperature, while CS3 and CS5 were exposed to 3°C for 3 and 5 hours, respectively, on alternate days lower than CS0 from 15d to 35d. On 50d, broilers in three groups were exposed to ACS at 10°C for 12 hours (Y12). The levels of corticosterone (CORT) and liothyronine (T3), mRNA and protein levels of heart adenosine monophosphate (AMP)-activated protein kinase/mammalian target of rapamycin (AMPK/mTOR) pathway genes were assessed at 36 d, 50 d and Y12.

RESULTS

At 36d, mRNA levels of AMPKα, acyl-CoA oxidase (ACO), mTOR, sterolregulatory element binding protein (SREBP), stearoyl-coA desaturase (SCD), acetyl-coA carboxylase (ACC), fatty acid synthase (FAS) and protein level of peroxisome proliferatorsactivated receptor α (PPARα) in CS3 and CS5 were significantly lower than those in CS0 (p<0.05). At 50d, compared to CS0, mRNA levels of PPARα, carnitine palmitoyltransferase1 (CPT1), ACO, tuberous sclerosis complex (TSC), SREBP and SCD, as well as protein levels of p-AMPKα/AMPKα, PPARα and SREBP were significantly increased in CS5 (p<0.05). At Y12, the levels of T3 in CS3 and CS5 were significantly higher than those in CS0 (p<0.05), mRNA levels of CPT1, ACO, SREBP, SCD and protein levels of p-AMPKα/AMPKα, SREBP, and FAS were significantly higher in CS5 than in CS0 and CS3 (p<0.05). However, compared to 50d, at Y12, mRNA levels of AMPKα, CPT1 and ACO in CS3 and CS5 significantly decreased (p<0.05), while protein levels of p-AMPKα/AMPKα significantly increased (p<0.05).

CONCLUSION

This study suggested that intermittent cold stimulation at 3°C lower than normal rearing temperature for 5h could help broilers adapt to the ACS by promoting heart lipid metabolism.

Fatty acid uptake activates an AXL-CAV1-β-catenin axis to drive melanoma progression

Interaction between the tumor microenvironment and cancer cell plasticity drives intratumor phenotypic heterogeneity and underpins disease progression and nongenetic therapy resistance. Phenotype-specific expression of the AXL receptor tyrosine kinase is a pivotal player in dormancy, invasion, and resistance to treatment. However, although the AXL ligand GAS6 is present within tumors, how AXL is activated in metastasizing cells remains unclear. Here, using melanoma as a model, we reveal that AXL is activated by exposure to human adipocytes and to oleic acid, a monounsaturated fatty acid abundant in lymph and in adipocytes. AXL activation triggers SRC-dependent formation and nuclear translocation of a β-catenin-CAV1 complex required for melanoma invasiveness. Remarkably, only undifferentiated AXLHigh melanoma cells engage in symbiosis with human adipocytes, in part by triggering WNT5a-mediated lipolysis, leading to AXL-dependent, but FATP-independent, fatty acid uptake and nuclear localization of the β-catenin-CAV1 complex. Significantly, human melanomas in the vicinity of adipocytes exhibit high levels of nuclear CAV1. The results unveil an AXL- and CAV1-dependent mechanism through which a nutritional input drives phenotype-specific activation of a prometastasis program. Given the key role of AXL in a broad range of cancers, the results offer major insights into the mechanisms of cancer cell dormancy and therapy resistance.

Maternal obesity associates with altered humoral immunity in blood and colostrum

Maternal obesity is a condition with increasing prevalence worldwide, that correlates with negative infant outcomes. Here we performed an observational cross-sectional study, where peripheral blood and colostrum samples from 37 mothers with BMI between 18.5-25 or > 30 kg/m2 (21 and 16 mothers, respectively) were collected 24-48 h postpartum. B lymphocyte subpopulations were investigated using flow cytometry. IgG, IgA, and IgM concentrations, and antibody production from colostrum-resident B cells were quantified. Overall, naïve B lymphocytes were the most abundant subtype in peripheral blood, while CD27-IgD- double-negative B cells were the most frequent in colostrum. The colostrum from mothers with BMI > 30 kg/m2 contained significantly more IgG-secreting colostrum-resident B cells, more total IgG, and less total IgA. Mothers with BMI > 30 kg/m2 who had been vaccinated with the Pfizer BioNTech bivalent vaccine during the third trimester of pregnancy (n = 8) did not show higher IgA or IgG antibody responses against SARS-CoV-2 RBD in either tissue types compared to unvaccinated mothers, contrasting with mother of BMI between 18.5-25 kg/m2 (n = 7). This is the first characterization of B lymphocyte subpopulations and antibodies in the colostrum of mothers with obesity. This work uncovers maternal obesity as a possible modifier of humoral immune components in colostrum.

Chromatin landscape in paired human visceral and subcutaneous adipose tissue and its impact on clinical variables in obesity

BACKGROUND

Obesity is a global health challenge and adipose tissue exhibits distinct depot-specific characteristics impacting differentially on the risk of metabolic comorbidities.

METHODS

Here, we integrate chromatin accessibility (ATAC-seq) and gene expression (RNA-seq) data from intra-individually paired human subcutaneous (SAT) and omental visceral adipose tissue (OVAT) samples to unveil depot-specific regulatory mechanisms.

FINDINGS

We identified twice as many depot-specific differentially accessible regions (DARs) in OVAT compared to SAT. SAT-specific regions showed enrichment for adipose tissue enhancers involving genes controlling extracellular matrix organization and metabolic processes. In contrast, OVAT-specific regions showed enrichment in promoters linked to genes associated with cardiomyopathies. Moreover, OVAT-specific regions were enriched for bivalent transcription start site and repressive chromatin states, suggesting a "lingering" regulatory state. Motif analysis identified CTCF and BACH1 as most significantly enriched motifs in SAT and OVAT-specific DARs, respectively. Distinct gene sets correlated with important clinical variables of obesity, fat distribution measures, as well as insulin, glucose, and lipid metabolism.

INTERPRETATION

We provide an integrated analysis of chromatin accessibility and transcriptional profiles in paired human SAT and OVAT samples, offering new insights into the regulatory landscape of adipose tissue and highlighting depot-specific mechanisms in obesity pathogenesis.

FUNDING

SS received EU-Scientia postdoctoral Fellowship and project funding from the European Union's Horizon 2020 Research and Innovation program under the Marie Skłodowska-Curie Grant, (agreement No. 801133). LlCP and TR were supported by Helse Sør-Øst grants to Y.B (ID 2017079, ID 278908). MB received funding from grants from the DFG (German Research Foundation)-Projekt number 209933838-SFB 1052 (project B1) and by Deutsches Zentrum für Diabetesforschung (DZD, Grant: 82DZD00601).

RGFP966 inhibits palmitic acid induced VSMCs phenotypic transition by targeting ATGL

BACKGROUND

The phenotypic switch of vascular smooth muscle cells (VSMCs) underlies the pathology of many cardiovascular diseases. Histone deacetylase 3 (HDAC3) is reported to upregulate in several cardiovascular diseases. RGFP966 is a highly selective HDAC3 inhibitor. This study aimed to explore the effects of RGFP966 on the phenotypic switch of VSMCs.

METHOD

First, we conducted an analysis of HDAC3 expression utilizing pertinent Gene Expression Omnibus (GEO) datasets. Then CCK-8, Edu, and wound healing assays were used to explore the effects of RGFP966 on the proliferation and migration of VSMCs and potential mechanisms at the cellular level.

RESULTS

Our results showed that palmitic acid (PA) induced the accumulation of lipid droplets in VSMCs, downregulated Adipose triglyceride lipase (ATGL), and increased VSMC viability and migration, which were significantly reversed by RGFP966. Additionally, siRNA targeting ATGL dramatically enhanced the VSMCs injury induced by PA. The autophagy inhibitor 3-Methyladenine (3-MA) partially reversed the decreased ATGL expression caused by PA. Furthermore, the p-mTOR/mTOR ratio decreased under PA induction and rebounded after administration of RGFP966.

CONCLUSION

RGFP966 has a protective effect against VSMCs phenotype transitions, potentially related to the regulation of ATGL.

PGC-1α mediates migrasome secretion accelerating macrophage-myofibroblast transition and contributing to sepsis-associated pulmonary fibrosis

Sepsis-associated pulmonary fibrosis (SAPF) is a critical pathological stage in the progression of sepsis-induced acute respiratory distress syndrome. While the aggregation and activation of lung fibroblasts are central to the initiation of pulmonary fibrosis, the macrophage-myofibroblast transition (MMT) has recently been identified as a novel source of fibroblasts in this context. However, the mechanisms driving MMT remain inadequately understood. Given the emerging role of migrasomes (novel extracellular vesicles mediating intercellular communication), we investigated their involvement in pulmonary fibrosis. Here we utilized a lipopolysaccharide-induced SAPF mouse model and an in vitro co-culture system of fibroblasts and macrophages to observe the MMT process during SAPF. We found that lipopolysaccharide exposure suppresses PGC-1α expression in lung fibroblasts, resulting in mitochondrial dysfunction and the accumulation of cytosolic mitochondrial DNA (mtDNA). This dysfunction promotes the secretion of mtDNA-containing migrasomes, which, in turn, initiate the MMT process and contribute to fibrosis progression. Notably, the activation of PGC-1α mitigates mitochondrial dysfunction, reduces mtDNA-migrasome release, inhibits MMT and alleviates SAPF. In conclusion, our study identifies the suppression of PGC-1α in lung fibroblasts and the subsequent release of mtDNA migrasomes as a novel mechanism driving MMT in SAPF. These findings suggest that targeting the crosstalk between fibroblasts and immune cells mediated by migrasomes could represent a promising therapeutic strategy for SAPF.

Irisin protects against cerebral ischemia reperfusion injury in a SIRT3-dependent manner

Background

Cerebral ischemia-reperfusion (CIR) injury critically impacts stroke prognosis, yet effective therapeutic strategies remain limited. Irisin, an exercise-induced myokine, exhibits neuroprotective effects against cerebral ischemia. SIRT3, a mitochondrial deacetylase, is similarly implicated in mitigating ischemia-reperfusion injury. Given that irisin exerts protection via AMPK/PGC-1α pathway activation and SIRT3 acts downstream of PGC-1α , we hypothesized that SIRT3 mediates irisin's neuroprotection in CIR injury.

Methods

In vivo cerebral ischemia-reperfusion injury was modeled by inducing transient middle cerebral artery occlusion (MCAO) in mice, while in vitro CIR conditions were replicated using oxygen-glucose deprivation (OGD) in PC12 neuronal cultures. To elucidate the mechanistic role of SIRT3, targeted interventions were implemented: SIRT3 expression was silenced via transfection with small interfering RNA (siRNA), and its enzymatic activity was pharmacologically inhibited using 3-TYP, a selective SIRT3 inhibitor. Apoptotic were systematically evaluated through TUNEL staining, Western blot analysis of caspase-3, Bax and Bcl-2. Oxidative stress parameters, including malondialdehyde (MDA) levels and glutathione (GSH) content, were measured using colorimetric assays. Neurological function in mice was quantified using the modified Neurological Severity Score (mNSS).

Results

Our results demonstrated that irisin mitigates apoptosis and oxidative stress by dose-dependently activating SIRT3 signaling. At the optimal dosage, irisin effectively restored SIRT3 expression levels, reduced neuronal damage, and improved neurological recovery in CIR injury models. Notably, the therapeutic effects of irisin were significantly attenuated by 3-TYP, a specific SIRT3 inhibitor. Further validation through in vitro experiments revealed that SIRT3 overexpression synergistically enhanced irisin-mediated protection against OGD-induced injury, whereas SIRT3 knockout substantially diminished its efficacy.

Conclusion

Our data shown that irisin exerted a protective role in CIR injury, at least in part, through SIRT3 activation. This study establishes the irisin/SIRT3 as a novel therapeutic target for ischemic stroke, providing mechanistic insights for future interventions.

Inhibition of ATGL alleviates MASH via impaired PPARα signalling that favours hydrophilic bile acid composition in mice

BACKGROUND & AIMS

Adipose triglyceride lipase (ATGL) is an attractive therapeutic target in insulin resistance and metabolic dysfunction-associated steatotic liver disease (MASLD). This study investigated the effects of pharmacological ATGL inhibition on the development of metabolic dysfunction-associated steatohepatitis (MASH) and fibrosis in mice.

METHODS

Streptozotocin-injected male mice were fed a high-fat diet to induce MASH. Mice receiving the ATGL inhibitor atglistatin (ATGLi) were compared to controls using liver histology, lipidomics, metabolomics, 16s rRNA, and RNA sequencing. Human ileal organoids, HepG2 cells, and Caco2 cells treated with the human ATGL inhibitor NG-497, HepG2 ATGL knockdown cells, gel-shift, and luciferase assays were analysed for mechanistic insights. We validated the benefits of ATGLi on steatohepatitis and fibrosis in a low-methionine choline-deficient mouse model.

RESULTS

ATGLi improved serum liver enzymes, hepatic lipid content, and histological liver injury. Mechanistically, ATGLi attenuated PPARα signalling, favouring hydrophilic bile acid (BA) synthesis with increased Cyp7a1, Cyp27a1, Cyp2c70, and reduced Cyp8b1 expression. Additionally, reduced intestinal Cd36 and Abca1, along with increased Abcg5 expression, were consistent with reduced levels of hepatic triacylglycerol species containing polyunsaturated fatty acids, like linoleic acid, as well as reduced cholesterol levels in the liver and plasma. Similar changes in gene expression associated with PPARα signalling and intestinal lipid transport were observed in ileal organoids treated with NG-497. Furthermore, HepG2 ATGL knockdown cells revealed reduced expression of PPARα target genes and upregulation of genes involved in hydrophilic BA synthesis, consistent with reduced PPARα binding and luciferase activity in the presence of the ATGL inhibitors.

CONCLUSIONS

Inhibition of ATGL attenuates PPARα signalling, translating into hydrophilic BA composition, interfering with dietary lipid absorption, and improving metabolic disturbances. Validation with NG-497 opens a new therapeutic perspective for MASLD.

IMPACT AND IMPLICATIONS

Despite the recent approval of drugs novel mechanistic insights and pathophysiology-oriented therapeutic options for MASLD (metabolic dysfunction-associated steatotic liver disease) are still urgently needed. Herein, we show that pharmacological inhibition of ATGL, the key enzyme in lipid hydrolysis, using atglistatin (ATGLi), improves MASH (metabolic dysfunction-associated steatohepatitis), fibrosis, and key features of metabolic dysfunction in mouse models of MASH and liver fibrosis. Mechanistically, we demonstrated that attenuation of PPARα signalling in the liver and gut favours hydrophilic bile acid composition, ultimately interfering with dietary lipid absorption. One of the drawbacks of ATGLi is its lack of efficacy against human ATGL, thus limiting its clinical applicability. Against this backdrop, we could show that ATGL inhibition using the human inhibitor NG-497 in human primary ileum-derived organoids, Caco2 cells, and HepG2 cells translated into therapeutic mechanisms similar to ATGLi. Collectively, these findings reveal a possible new avenue for MASLD treatment.

Physical exercise, systemic inflammation and adult-onset asthma: a 12-year follow-up study

Objective: Physical exercise in treatment of asthma is scarcely studied with no clear exercise guidelines for asthmatics. We aimed to investigate the associations between physical exercise frequency, systemic inflammation and asthma control. This has not been previously studied in adult-onset asthma.

Methods: This study is part of Seinäjoki Adult Asthma Study (SAAS), where 203 patients with adult-onset asthma were evaluated in 2012-2013. Exercise frequency was recorded with a structured lifestyle questionnaire. Study population was divided into two categories by exercise frequency: Low-frequency group exercised ≤2 times/week and high frequency group >2 times/week. Blood inflammatory markers were measured and IL-6 > 1.55 pg/ml and hs-CRP > 4.12 mg/l indicated systemic inflammation.

Results: High-exercise frequency group had lower levels of hs-CRP (p = 0.007), IL-6 (p = 0.015), suPAR (p = 0.008) and adipsin (p = 0.031) and higher levels of adiponectin (p = 0.010) than low-exercise frequency group. In logistic multivariate regression models, higher-exercise frequency lowered odds for elevated hs-CRP (OR = 0.37, 95% CI 0.15-0.94) and IL-6 levels (OR = 0.43, 95% CI 0.20-0.91), after adjusting for possible confounding factors. There was no difference in lung function tests, asthma control test or airways questionnaire 20 scores between the exercise frequency groups. However, differences were found in single symptom questions; high-exercise frequency group had less symptoms during light housework and laughing but experienced more limitation of activity in self-reports.

Conclusions: Higher-exercise frequency is associated with lower level of systemic inflammation in patients with adult-onset asthma but no clear association was found to asthma outcomes. Exercise frequency may be associated with lesser amount of some individual asthma symptoms.

Retinoic acid signaling and metabolism in heart failure

Nearly 70 years after studies first showed that the offspring of vitamin A (retinol, ROL)-deficient rats exhibit structural cardiac defects and over 20 years since the role of vitamin A's potent bioactive metabolite hormone, all-trans retinoic acid (ATRA), was elucidated in embryonic cardiac development, the role of the vitamin A metabolites, or retinoids, in adult heart physiology and heart and vascular disease, remains poorly understood. Studies have shown that low serum levels of retinoic acid correlate with higher all-cause and cardiovascular mortality, though the relationship between circulating retinol and ATRA levels, cardiac tissue ATRA levels, and intracellular cardiac ATRA signaling in the context of heart and vascular disease has only begun to be addressed. We have recently shown that patients with idiopathic dilated cardiomyopathy show a nearly 40% decline of in situ cardiac ATRA levels, despite adequate local stores of retinol. Moreover, we and others have shown that the administration of ATRA forestalls the development of heart failure (HF) in rodent models. In this review, we summarize key facets of retinoid metabolism and signaling and discuss mechanisms by which impaired ATRA signaling contributes to several HF hallmarks including hypertrophy, contractile dysfunction, poor calcium handling, redox imbalance, and fibrosis. We highlight unresolved issues in cardiac ATRA metabolism whose pursuit will help refine therapeutic strategies aimed at restoring ATRA homeostasis.

Curcumin supplementation combined with high intensity interval training modulates serum irisin and lipid profile in obese women: "A randomized double-blind clinical trial"

Background

Curcumin is the most widely known active substance of turmeric extract, which attributed numerous functional properties, including anti-inflammatory and cardioprotective properties. Inactivity and changes in lifestyle and subsequent overweight/obesity are becoming major health risk factors.

Objective

the aim of this study was to determine the effect of curcumin supplementation combined with high intensity interval trainings (HIIT) exercise on serum irisin and lipid profile in obese women.

Methods

40 inactive women (aged 30-35 years, and body mass index 30 and above) allocated in four groups (10 in each) as followed; curcumin (C), exercise plus curcumin (EC), placebo (P), and exercise plus placebo (EP). All subjects completed an eight-week HIIT program. The C and EC groups received one capsule containing 80 mg curcumin nanomicelle daily throughout study. Blood samples were taken in the beginning and after eight weeks to measure changes in the study variables (irisin and lipid profile). The ANCOVA and Bonferroni's post hoc test was used to compare variables between 4 groups and pairwise at a significance level of ≤0.05 using SPSS-22.

Results

The results revealed that mean serum irisin (p = 0.023), cholesterol (p = 0.019), triglyceride (p = 0.022), high-density lipoprotein (p = 0.009) and low-density lipoprotein (p = 0.011) were significantly changed in all intervention groups compared to the placebo group.

Conclusion

Based on these results, it can be concluded that HIIT training with curcumin consumption has a greater significancy on obesity reduction in women; Therefore, curcumin and HIIT exercise can be considered as a therapeutic approach to reduce the negative outcomes of obesity.

Clinical trial registry number

IRCT20141004019397N2, link.

Statement of significance

This study investigated the effects of curcumin supplementation combined with high-intensity interval training (HIIT) on human serum Irisin levels for the first time, in a clinical randomized trial. This suggests that HIIT training alongside curcumin consumption may be a promising therapeutic approach to reduce the negative health consequences of obesity in women.

Resinacein S, a novel triterpenoid from functional mushroom Ganoderma resinaceum, curbs obesity by regulating thermogenesis and energy metabolism

Ganoderma mushrooms are popularly used as dietary supplements to promote health around the world. However, their potential applications for the prevention and treatment of obesity needs to be further investigated. In this study, we isolated a novel triterpenoid from Ganoderma resinaceum, Resinacein S (Res S), and determined its absolute configuration. We reported that Res S treatment significantly inhibited the high-fat HF diet-induced body weight gain though increased thermogenesis and energy metabolism. Specifically, treatment with Res S promoted brown adipose tissue activation and browning of inguinal white adipose tissue, improving whole-body glucose and lipid homeostasis. Mechanistically, Res S treatment induced the expression of thermogenic genes and related protein, for example, uncoupling protein 1 and mitochondrial biogenesis in a cell-autonomous manner by activating the AMPK-PGC1α signaling pathway. These findings identify Res S as a potential therapeutic alternative for obesity in the setting of its increasingly high prevalence. HIGHLIGHTS: Resinacein S (Res S) exhibited potent anti-obesity effects in high-fat diet-fed mice; Res S treatment significantly promoted brown adipose tissue activation and browning of inguinal white adipose tissue; Res S treatment stimulated UCP1 expression and enhanced mitochondrial function; Res S induced adipocyte thermogenic activity through activating the AMPK-PGC1α axis.

Growth, fusion and degradation of lipid droplets: advances in lipid droplet regulatory protein

Context: An adequate supply of energy is essential for the proper functioning of all life activities in living organisms. As organelles that store neutral lipids, lipid droplets (LDs) are involved in the synthesis and metabolism of lipids in cells and are also an important source of energy supply.

Methods and mechanisms: A comprehensive summary of the literature was first carried out to screen for relevant proteins affecting the morphological size of LDs. The size of milk fat globules (MFGs) is directly influenced by the morphological size of LDs, which also controls the energy storage capacity of LDs. In this review, we detail the progress of research into the role of some protein in regulating the morphological size of LDs.

Conclusion: It has been discovered that the number of protein are involved in the control of LD growth and degradation, such as Rab18-mediated local synthesis of triacylglycerol (TAG), cell death-inducing DFF45-like effector family proteins (CIDEs)-mediated atypical fusion between LDs, Stomatin protein-mediated LD fusion and autophagy-related proteins (ATGs)-mediated autophagic degradation of LDs. However, more studies are needed in the future to enrich the network of mechanisms that regulate the morphological size of LDs.

rhCC16 Suppresses Cellular Senescence and Ameliorates COPD-Like Symptoms by Activating the AMPK/Sirt1-PGC-1-α-TFAM Pathway to Promote Mitochondrial Function

Chronic obstructive pulmonary disease (COPD) is a widespread lung disease marked by alveolar wall damage, leading to inflammation and fibrosis. Key risk factors include age, smoking, sex, and education, with smoking being the most crucial. These factors are globally consistent and linked with aging. Club cell secretory protein 16 (CC16), primarily secreted by non-ciliated bronchial epithelial cells, is crucial for pulmonary health, offering anti-inflammatory and antioxidant benefits. CC16 levels are notably reduced in COPD, suggesting its enhancement as a potential treatment. In this study, cellular senescence of BEAS-2B cells was stimulated using cigarette smoke extract (CSE) and the function of recombinant human CC16 protein (rhCC16) in cellular senescence was assessed by detecting the levels of β-galactosidase, p16, p21, ROS and the underlined mechanism was revealed by measuring mitochondrial biogenesis and metabolism. Additionally, COPD mice were prepared, and rhCC16's role on the cellular senescence of lung tissues was examined. Our findings showed that rhCC16 ameliorated cellular senescence in BEAS-2B cells and lung tissues of COPD mice accompanied by lower levels of β-galactosidase, p16, p21 and ROS. Mechanically, rhCC16 mitigated senescence via triggering PGC-1α expression through the AMPK/SIRT1 pathway and fostering mitochondrial biogenesis and metabolism to reduce the levels of ROS. Furthermore, the results also indicated that rhCC16 exerted its effect via both integrin α4β1 and clathrin-mediated endocytosis. Collectively, rhCC16 suppresses cellular senescence and ameliorates COPD-like symptoms by activating the AMPK/Sirt1-PGC-1-α-TFAM pathway to foster mitochondrial function.

Adipocyte-derived shed Syndecan-4 suppresses lipolysis contributing to impaired adipose tissue browning and adaptive thermogenesis

Lipolysis in white adipose tissue (WAT) provides fatty acids as energy substrates for thermogenesis to increase energy expenditure. Syndecan-4 (Sdc4) is a transmembrane proteoglycan bearing heparan sulfate chains. Although single nucleotide polymorphisms (SNPs) of the Sdc4 gene have been identified linking to metabolic syndromes, its specific function in adipose tissue remains obscure. Here, we show that Sdc4 serves as a regulator of lipid metabolism and adaptive thermogenesis. Sdc4 expression and shedding are elevated in the white adipose tissue (WAT) of diet-induced obese mice. Adipocyte-specific deletion of Sdc4 promotes lipolysis and WAT browning, thereby raising whole-body energy expenditure to protect against diet-induced obesity. Mechanistically, fibroblast growth factor 2 (FGF2) is a paracrine factor that maintains energy homeostasis. Elevated shed Sdc4 concentrates and delivers FGF2 to fibroblast growth factor receptor 1 (FGFR1) on adipocytes, which in turn suppresses lipolysis by reducing hormone-sensitive lipase (HSL) activity, thus exaggerating adipose tissue dysfunction upon high-fat diet induction. Sdc4-deficient adipocytes show higher lipolytic and thermogenic capacity by enhancing HSL phosphorylation and UCP1 expression. Overall, our study reveals that adipocyte-derived shed Sdc4 is a novel suppressor of lipolysis, contributing to decreased energy expenditure, thus exaggerating obesity. Targeting shed Sdc4 is a potential therapeutic strategy for obesity.

A specific metabolomic and lipidomic signature reveals the postpartum resolution of gestational diabetes mellitus or its evolution to type 2 diabetes in rat

Gestational diabetes mellitus (GDM) represents a major public health concern due to adverse maternal postpartum and long-term outcomes. Current strategies to manage GDM fail to reduce the maternal risk to develop later impaired glucose tolerance (IGT) and type 2 diabetes (T2D). In a rodent model of diet-induced GDM without obesity, we explored the perinatal metabolic adaptations in dams with gestational IGT followed by either persistent or resolved postpartum IGT. Female Sprague-Dawley rats were fed a high-fat high-sucrose (HFHS) or a chow [control group (CTL)] diet, 1 wk before mating and throughout gestation (G). Following parturition, HFHS dams were randomized to two subgroups: one switched to a chow diet and the other one maintained on an HFHS diet throughout lactation (L). Oral glucose tolerance tests (OGTTs) were performed, and plasma metabolome-lipidome were characterized at G12 and L12. We found that 1) in GDM-pregnant dams, IGT was associated with incomplete fatty acid oxidation (FAO), enhanced gluconeogenesis, altered insulin signaling, and oxidative stress; 2) improved glucose tolerance postpartum seemed to restore complete FAO along with elevation of nervonic acid-containing sphingomyelins, assumed to impart β-cell protection; and 3) persistence of IGT after delivery was associated with metabolites known to predict the early onset of insulin and leptin resistance, with maintained liver dysfunction. Our findings shed light on the impact of postpartum IGT evolution on maternal metabolic outcome after an episode of GDM. They suggest innovative strategies, implemented shortly after delivery and targeted on these biomarkers, should be explored to curb or delay the transition from GDM to T2D in these mothers.NEW & NOTEWORTHY Specific metabolomic/lipidomic features are associated with GDM postpartum outcomes. GDM-pregnant dams exhibit partial fatty acid oxidation and boosted gluconeogenesis. Resolution of postpartum IGT relies on nervonic acid-sphingomyelin, a β-cell protector. Postpartum IGT persistence suggests muscle insulin resistance and liver dysfunction.

Expression of p53 in human adipose tissue correlates positively with FAS and BMI

Activation of Fas (CD95) in adipocytes inhibits browning and may contribute to body weight gain in mice. Moreover, Fas expression in white adipose tissue (WAT) correlates positively with body mass index (BMI) in humans. However, molecular pathways involved in the inhibitory effect of Fas on energy metabolism remain incompletely understood. Herein, we report that protein levels of the tumor suppressor p53 were reduced in primary white adipocytes of adipocyte-specific Fas-knockout mice. Moreover, Fas ligand (FasL) treatment increased p53 concentrations in cultured adipocytes and decreased mitochondrial oxygen consumption in control but not in p53-depleted cells, indicating that Fas activation reduces energy expenditure in a p53-dependent manner. In line, in differentiated human mesenchymal stem cells and WAT derived from different anatomical depots, FAS expression was positively associated with p53. Furthermore, p53 expression in human subcutaneous and visceral WAT correlated positively with BMI, whereas its expression in visceral WAT was inversely associated with insulin sensitivity (as assessed by hyperinsulinemic-euglycemic clamp). Taken together, our data suggest that Fas regulates p53 expression in adipocytes, and may thereby affect body weight gain and insulin sensitivity.

An Overview of Sarcopenia: Focusing on Nutritional Treatment Approaches

Sarcopenia is a syndrome characterized by the progressive and generalized loss of skeletal muscle mass and strength. This condition is associated with physical disability, decreased quality of life, and increased mortality. Therefore, reducing the prevalence of sarcopenia could significantly lower healthcare costs. Sarcopenia can be classified into primary and secondary sarcopenia. The former is related to aging and begins after the fourth decade of life; after that, there is a muscle loss of around 8% per decade until age 70 years, which subsequently increases to 15% per decade. On the other hand, secondary sarcopenia can affect all individuals and may result from various factors including physical inactivity, malnutrition, endocrine disorders, neurodegenerative diseases, inflammation, and cachexia. Understanding the multiple mechanisms involved in the onset and progression of sarcopenia allows for us to develop strategies that can prevent, treat, or at least mitigate muscle loss caused by increased protein breakdown. One potential treatment of sarcopenia is based on nutritional interventions, including adequate caloric and protein intake and specific nutrients that support muscle health. Such nutrients include natural food rich in whey protein and omega-3 fatty acids as well as nutritional supplements like branched-chain amino acids, β-hydroxy-β-methylbutyrate, and vitamin D along with food for special medical purposes. It is important to emphasize that physical exercises, especially resistance training, not only promote muscle protein synthesis on their own but also work synergistically with nutritional strategies to enhance their effectiveness.

Insights into dentatorubral-pallidoluysian atrophy from a new Drosophila model of disease

Dentatorubral-pallidoluysian atrophy (DRPLA) is a neurodegenerative disorder that presents with ataxia, dementia and epilepsy. As a member of the polyglutamine family of diseases, DRPLA is caused by abnormal CAG triplet expansion beyond 48 repeats in the protein-coding region of ATROPHIN 1 (ATN1), a transcriptional co-repressor. To better understand DRPLA, we generated new Drosophila lines that can be induced to express full-length, human ATN1 with a normal (Q7) or pathogenic (Q88) repeat in a variety of cells, including neuronal, glial or any other type of tissue. Expression of ATN1 is toxic, with the polyglutamine-expanded version being consistently more problematic than wild-type ATN1. Fly motility, longevity and internal structures are negatively impacted by pathogenic ATN1. RNA-seq identified altered protein quality control and immune pathways in the presence of pathogenic ATN1. Based on these data, we conducted genetic experiments that confirmed the role of protein quality control components that ameliorate or exacerbate ATN1 toxicity. Hsc70-3, a chaperone, arose as a likely suppressor of toxicity. VCP (a proteasome-related AAA ATPase), Rpn11 (a proteasome-related deubiquitinase) and select DnaJ proteins (co-chaperones) were inconsistently protective, depending on the tissues where they were expressed. Lastly, informed by RNA-seq data that exercise-related genes may also be involved in this model of DRPLA, we conducted short-term exercise, which improved overall fly motility. This new model of DRPLA will prove important to understanding this understudied disease and will help to identify therapeutic targets for it.

Chaihuang Yishen Granule ameliorates mitochondrial homeostasis by upregulating PRDX5/TFAM axis to inhibit renal fibrosis in CKD

BACKGROUND

Chaihuang Yishen Granules (CHYS) has been clinically proven to be effective for the treatment of chronic kidney disease (CKD), yet its underlying molecular mechanisms remain largely unexplored.

OBJECTIVE

To explore the innovative mechanisms by which CHYS alleviates CKD, focusing on its role in modulating PRDX5/TFAM-mediated mitochondrial homeostasis in renal cells.

METHODS

In this study, CKD mouse model was established by unilateral ureteral obstruction (UUO) and adenine (Ade) diet. Treatment interventions were administered by gavage with CHYS at doses of 3.8g/kg (low dose) and 7.6g/kg (high dose). The ameliorative effects of CHYS on CKD were evaluated by changes in renal function, kidney tissue structure, renal fibrosis, and mitochondrial dysfunction markers. Tert‑butyl hydroperoxide (t-BHP)-induced oxidative stress in TCMK1 cells was used to simulate CKD renal fibrosis induced by mitochondrial dysfunction in vitro.

RESULTS

CHYS significantly improves renal function and mitigates fibrosis while restoring mitochondrial homeostasis. Notably, PRDX5 expression, which is markedly reduced in CKD patients and mouse models, is substantially upregulated following CHYS treatment. Meanwhile, we demonstrate that ultrasound microbubble-mediated in situ overexpression of PRDX5 confers considerable renal protection in the UUO model. In vitro data show that CHYS effectively prevents t-BHP-induced mtDNA leakage in renal tubular cells, preserving mitochondrial function and stability, an effect compromised by PRDX5 knockdown. Moreover, our protein binding assays uncover a previously unreported interaction between PRDX5 and TFAM, with TFAM knockdown reversing the mitochondrial functional and fibrotic improvements achieved through PRDX5 overexpression and CHYS intervention.

CONCLUSION

These findings introduce a pioneering perspective on CHYS's mechanism of action. CHYS enhance TFAM activation through PRDX5 upregulation, counteract ROS-induced mitochondrial damage, and restoring mitochondrial homeostasis, and alleviates the progression of renal fibrosis in CKD, highlighting the innovative therapeutic potential of CHYS in mitochondrial-related renal pathologies.

Examining a role for irisin in treating cerebral ischemia

Stroke is a leading cause of death and disability, with ischemic stroke representing most cases. Age is the most significant nonmodifiable risk factor for stroke, and with an aging population, there is an urgent need for effective prevention and treatment strategies. Physical inactivity is a strong risk factor for stroke, and exercise has long been held as a promising approach to improve poststroke outcomes. During exercise, the myokine irisin is released as a product of a type 1 membrane protein cleavage that is encoded by the fibronectin type III domain containing 5 (FNDC5) gene. This review summarizes recent literature on irisin's role in ischemic stroke, examining central effects, stroke risk, poststroke functional outcomes, and exogenous administration. Irisin has value as a prognostic marker for risk stratification. Low levels of irisin correlate with worse outcomes and higher mortality in patients with ischemic stroke. Irisin may also be a key to the benefits of exercise, particularly for high-intensity resistance training, which significantly increases irisin levels. Beyond exercise, exogenous irisin is neuroprotective in murine models, reducing brain edema, inflammation, and apoptosis, and increasing blood-brain barrier integrity and brain-derived neurotrophic factor levels. This underscores irisin's potential to mitigate ischemic damage and promote recovery. Human trials are necessary to validate these findings and explore the feasibility of irisin-based interventions in acute stroke care. This review lays a foundation for future research to clarify irisin's therapeutic benefits, establish optimal exercise protocols, and explore exogenous irisin as a novel intervention for ischemic stroke.

Mechanisms of Lipid-Associated Macrophage Accrual in Metabolically Stressed Adipose Tissue

Adipose tissue (AT) inflammation, a hallmark of the metabolic syndrome, is triggered by overburdened adipocytes sending out immune cell recruitment signals during obesity development. An AT immune landscape persistent throughout weight loss and regain constitutes an immune-obesogenic memory that hinders long-term weight loss management. Lipid-associated macrophages (LAMs) are emerging as major players in diseased, inflamed metabolic tissues and may be key contributors to an obesogenic memory in AT. Our previous study found that LAM abundance increases with weight loss via intermittent fasting (IF) in obese mice, which is driven by adipocyte p53 signalling. However, the specific signals causing LAM accumulation in AT under IF remain unknown. In this piece, we hypothesise on a range of adipocyte-secreted signals that can harbor immune-attractive features upon fasting/refeeding cycles. We highlight possible mechanisms including cell death signalling, matrikines, and other damage-associated molecular patterns (DAMPs), as well as adipo(-cyto)kines, lipid mediators, metabolites, extracellular vesicles, and epigenetic rewiring. Finally, we consider how advances in mechanisms of AT LAM recruitment gleaned from preclinical models might be translatable to long-term weight management in humans. Thus, we provide vantage points to study signals driving monocyte recruitment, polarisation towards LAMs, and LAM retention, to harness the therapeutic potential of modulating AT LAM levels by impacting the immune-obesogenic memory in metabolic disease.

Z-Spectral MRI Quantifies the Mass and Metabolic Activity of Adipose Tissues With Fat-Water-Fraction and Amide-Proton-Transfer Contrasts

BACKGROUND

Brown adipose tissue (BAT) is metabolically activatable and plays an important role in obesity and metabolic diseases. With reduced fat-water-fraction (FWF) compared with white adipose tissue (WAT), BAT mass and its functional activation may be quantified with Z-spectra MRI, with built-in FWF and the metabolic amide proton transfer (APT) contrasts.

PURPOSE

To investigate if Z-spectral MRI can quantify the mass and metabolic activity of adipose tissues.

STUDY TYPE

Prospective.

SUBJECTS

Seven groups of 8-week-old male rats, including two groups (n = 7 per group) for in vivo MRI study and five groups (n = 5 per group) for ex vivo validation; 12 young and healthy volunteers with 6 male and 6 female.

FIELD STRENGTH/SEQUENCE

The 7 T small animal and 3 T clinical systems, T2-weighted imaging, Rapid Acquisition with Relaxation Enhancement (RARE) readout based chemical exchange saturation transfer (CEST) Z-spectral MRI sequence.

ASSESSMENT

Quantified FWF and APT from Z-spectra in rats before and after norepinephrine (NE) stimulation and in healthy human subjects; ex vivo measurements of total proteins in BAT from rats.

STATISTICAL TESTS

Two-tailed unpaired Student's t-tests and repeated measures ANOVA. P-value <0.05 was considered significant.

RESULTS

Decreased FWF (from 39.6% ± 7.2% before NE injection to 16.4% ± 7.2% 120 minutes after NE injection, P < 0.0001) and elevated APT (from 1.1% ± 0.5% before NE injection to 2.9% ± 0.5% 120 minutes after NE injection, P < 0.0001) signals in BAT were observed with in vivo Z-spectral MRI in rats injected with NE at 7 T MRI. At clinical 3 T, Z-spectral MRI was used to quantify the FWF (58.5% ± 7.2% in BAT and 73.7% ± 6.5% in WAT with P < 0.0001) and APT (2.6% ± 0.8% in BAT and 0.9% ± 0.3% in WAT with P < 0.0001) signals in healthy volunteers. APT signals of BAT were negatively correlated with the BMI in humans (r = 0.71).

DATA CONCLUSION

Endogenous Z-spectral MRI was demonstrated to simultaneously quantify BAT mass and function based on its FWF and APT contrasts.

LEVEL OF EVIDENCE: 2

TECHNICAL EFFICACY STAGE

1.

Transcriptional Intermediary Factor 1γ-Induced Irisin in Skeletal Muscle Attenuates Renal Fibrosis in Diabetic Nephropathy

BACKGROUND

Transcriptional intermediary factor 1γ (TIF1γ) is a negative regulator of TGF-β1 signalling and has been associated with patient survival in renal cell carcinoma. However, its role in diabetes mellitus (DM), particularly in diabetic nephropathy (DN), remains unclear. DN is the leading cause of chronic kidney disease (CKD). We investigated the potential role of TIF1γ in mitigating multiple DM-related complications.

METHODS

Mice were divided into four groups: db/m+, db/db and db/db mice treated with cytomegalovirus- or TGF-TIF1γ plasmids (40 μg/mouse; intraperitoneally weekly for 16 weeks). Renal injury, fibrosis, function and gene expression related to fibrosis and epithelial-mesenchymal transition (EMT) in the kidneys were assessed. Muscle atrophy, regeneration markers, myokine levels and exercise capacity were evaluated. C2C12 cells were exposed to palmitate with or without TIF1γ transfection, and irisin expression and secretion were measured. Muscle-kidney crosstalk was analysed using conditioned media (CM) from TIF1γ-transfected C2C12 cells in palmitate-treated human kidney (HK)-2 cells. Additionally, HK-2 cells were incubated in CM from fibronectin type III domain-containing protein (FNDC)5-knockdown C2C12 cells to confirm irisin-mediated kidney crosstalk by TIF1γ.

RESULTS

TIF1γ treatment in db/db mice resulted in a significant attenuation of renal tubulointerstitial fibrosis (1.5-fold decrease), glomerular injury (1.8-fold improvement), tubular injury (1.6-fold improvement), renal dysfunction (1.7-fold improvement) and a reduction in EMT-related factors (1.8-fold decrease) (p < 0.05). The levels of administered TIF1γ plasmids were higher in skeletal muscle than in renal tissues. TIF1γ expression was significantly elevated in the skeletal muscle of db/db mice treated with TIF1γ plasmids (6.5-fold) (p < 0.05). Mice receiving both plasmids exhibited a 1.8-fold reduction in pathological muscle morphology and atrophy-related gene expression, a 3.0-fold increase in regeneration-related gene expression and a 1.6-fold improvement in muscle function (p < 0.05). Irisin expression increased by 2.1-fold in skeletal muscle and serum (p < 0.05). In TIF1γ-transfected C2C12 cells, irisin secretion was elevated by 1.5-fold (p < 0.05). CM from TIF1γ-transfected C2C12 cells attenuated EMT in palmitate-treated HK-2 cells, compared with medium from nontransfected C2C12 cells (1.9-fold improvement [p < 0.05]). Conversely, FNDC5 knockdown in C2C12 cells accelerated EMT in palmitate-treated HK-2 cells, as evidenced by decreased bone morphogenetic protein-7 (1.6-fold) and increased EMT-related factors (2.1-fold) (p < 0.05), compared with palmitate alone and small interfering RNA control.

CONCLUSIONS

Our findings emphasize the potential of TIF1γ as a multitargeted therapeutic agent for DN, mitigating both renal and muscular complications through direct fibrosis inhibition and indirect myokine-mediated inter-organ crosstalk.

Bdyof is a Y-chromosome-specific gene required for male development in Bactrocera dorsalis

BACKGROUND

In many organisms, the Y chromosome contains important genes associated with sex determination and male reproductive development. However, there have been few studies of Y-chromosome-specific genes in non-model species due to the incomplete information of Y chromosome genome and difficulty in sequencing. Here, we screened 90 candidate Y-specific sequences in a constructed transcriptome assembly library by using the chromosome quotient method, among which 11 were unreported sequences associated with male reproductive development, including Bactrocera dorsalis Y-specific Oligozoospermia factor (Bdyof) with the highest expression in the testis.

RESULTS

CRISPR/Cas9-mediated knockout of Bdyof resulted in abnormal testis development, significantly reduced sperm count, and obviously lower egg hatching rate in homozygous mutant flies. In addition, Bdyof knockout decreased the expression of dsx-M.

CONCLUSION

This results provides new insights into the biological processes related to male reproductive development controlled by the Y-chromosome-specific gene Bdyof, thus providing a promising molecular target for the study of agricultural pests. © 2024 Society of Chemical Industry.

Homeobox C4 Transcription Factor Promotes Adipose Tissue Thermogenesis

ARTICLE HIGHLIGHTS

Homeobox C4 (HOXC4) links metabolic pathways and correlates inversely with mouse body weight and positively with Ucp1 expression in mouse adipose tissue. Gain- and loss-of-function experiments in mice demonstrated HOXC4's essential role in promoting adipose thermogenesis and providing metabolic benefits. HOXC4 interacts with the nuclear receptor coactivator 1 cofactor via its hexapeptide motif to activate Ucp1 transcription, revealing a novel mechanism of thermogenic gene regulation.

Aging: A struggle for beneficial to overcome negative factors made by muscle and bone

Musculoskeletal health is strongly influenced by regulatory interactions of bone and muscle. Recent discoveries have identified a number of key mechanisms through which soluble factors released during exercise by bone exert positive effects on muscle and by muscle on bone. Although exercise can delay the negative effects of aging, these beneficial effects are diminished with aging. The limited response of aged muscle and bone tissue to exercise are accompanied by a failure in bone and muscle communication. Here, we propose that exercise induced beneficial factors must battle changes in circulating endocrine and inflammatory factors that occur with aging. Furthermore, sedentary behavior results in the release of negative factors impacting the ability of bone and muscle to respond to physical activity especially with aging. In this review we report on exercise responsive factors and evidence of modification occurring with aging.

Thermogenesis and Energy Metabolism in Brown Adipose Tissue in Animals Experiencing Cold Stress

Cold exposure is a regulatory biological functions in animals. The interaction of thermogenesis and energy metabolism in brown adipose tissue (BAT) is important for metabolic regulation in cold stress. Brown adipocytes (BAs) produce uncoupling protein 1 (UCP1) in mitochondria, activating non-shivering thermogenesis (NST) by uncoupling fuel combustion from ATP production in response to cold stimuli. To elucidate the mechanisms underlying thermogenesis and energy metabolism in BAT under cold stress, we explored how cold exposure triggers the activation of BAT thermogenesis and regulates overall energy metabolism. First, we briefly outline the precursor composition and function of BA. Second, we explore the roles of the cAMP- protein kinase A (PKA) and adenosine monophosphate-activated protein kinase (AMPK) signaling pathways in thermogenesis and energy metabolism in BA during cold stress. Then, we analyze the mechanism by which BA regulates mitochondria homeostasis and energy balance during cold stress. This research reveals potential therapeutic targets, such as PKA, AMPK, UCP1 and PGC-1α, which can be used to develop innovative strategies for treating metabolic diseases. Furthermore, it provides theoretical support for optimizing cold stress response strategies, including the pharmacological activation of BAT and the genetic modulation of thermogenic pathways, to improve energy homeostasis in livestock.

Histological Analysis of Biological Width and Collagen Fibers Orientation Around Screw-Less, Morse Taper, Hemispherical Base Abutments 8 and 16 Weeks After Implant Uncovering: An Observational Clinical Trial

Objectives: This study aimed to histologically evaluate, in humans, the orientation of collagen fibers around screw-less, Morse taper, hemispherical base abutments. Methods: This study was designed as an observational, case-control, clinical trial to evaluate the histological orientation of collagen fibers around implants. Biopsies of the peri-implant tissue were performed 8 (group A, control) or 16 (group B, test) weeks of implant uncovering, and histologically analyzed under optical microscope using Hematoxylin and Eosin, Masson, and Picro Sirius histochemical staining and a scanning electron microscope. Results: Eight patients were enrolled in this study and 16 biopsies were performed. All the biopsies were correctly analyzed. The histological examination of cross-sectional portions of the tissue taken 8 weeks after implant uncovering showed the almost complete absence of epithelial lining, while the connective tissue bundles in the superficial portion showed a lower circular pattern. The histochemical cross-section examination of the tissue taken 16 weeks after implant uncovering showed the partial presence of non-keratinizing epithelial lining at the implant site and the collagen bundles showed a greater organization, with a circumferential course around the abutment. At 8 weeks, the final histological analysis showed an average height of 1.01 mm for the keratinized epithelium, 0.83 mm for the non-keratinized epithelium, and 1.39 mm for the connective tissue. While, at 16 weeks, the values were 1.20 mm, 0.48 mm, and 1.11 mm, respectively. No statistically significant differences were found between the groups (p > 0.05). Conclusions: Histologically, there were not any differences in the height and profile of the gingiva between 8 and 16 weeks of healing after prosthesis delivery. Greater organization of the collagen fibers with a circumferential course around the abutment was found in the test group (16 weeks) compared with the control group (8 weeks).

Targeting mitochondria-regulated ferroptosis: A new frontier in Parkinson's disease therapy

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the progressive loss of dopaminergic neurons in the substantial nigra. Mitochondrial dysfunction and mitochondrial oxidative stress are central to the pathogenesis of PD, with recent evidence highlighting the role of ferroptosis - a type of regulated cell death dependent on iron metabolism and lipid peroxidation. Mitochondria, the central organelles for cellular energy metabolism, play a pivotal role in PD pathogenesis through the production of Reactive oxygen species (ROS) and the disruption of iron homeostasis. This review explores the intricate interplay between mitochondrial dysfunction and ferroptosis in PD, focusing on key processes such as impaired electron transport chain function, tricarboxylic acid (TCA) cycle dysregulation, disruption of iron metabolism, and altered lipid peroxidation. We discuss key pathways, including the role of glutathione (GSH), mitochondrial ferritin, and the regulation of the mitochondrial labile iron pool (mLIP), which collectively influence the susceptibility of neurons to ferroptosis. Furthermore, this review emphasizes the importance of mitochondrial quality control mechanisms, such as mitophagy and mitochondrial biogenesis, in mitigating ferroptosis-induced neuronal death. Understanding these mechanisms linking the interplay between mitochondrial dysfunction and ferroptosis may pave the way for novel therapeutic approaches aimed at preserving mitochondrial integrity and preventing neuronal loss in PD.

Adipose Tissue in Chagas Disease: A Neglected Component of Pathogenesis

Chagas disease (CD), caused by the protozoan T. cruzi, is a serious public health issue with high morbidity and mortality rates. Approximately 7 million people are infected, mostly in Latin America. The pathogenesis is multifactorial and poorly elucidated, particularly regarding the role of adipose tissue (AT). This review aims to explore the complex relationship between T. cruzi and AT, focusing on the possible role of this tissue in CD, as well as to explore the impact of diet on the progression of the disease. T. cruzi infects adipocytes, affecting their function. Chronic infection alters adipose physiology, contributing to systemic inflammation and metabolic disturbances. Adipokines are dysregulated, while markers of inflammation and oxidative stress increase within AT during CD. Additionally, the immune response and clinical aspects of CD may be influenced by the host's diet. High-fat diets (HFDs) impact parasite burden and cardiac pathology in murine models. The complex interaction among T. cruzi infection, AT dysfunction, and dietary factors underscore the complexity of CD pathogenesis. Despite accumulating evidence suggesting the role of AT in CD, further research is needed to elucidate its clinical implications. Understanding the bidirectional relationship between AT and T. cruzi infection may offer insights into disease progression and potential therapeutic targets, highlighting the importance of considering adipose physiology in CD management strategies.

Neuroprotective mechanisms of exercise and the importance of fitness for healthy brain ageing

Ageing is a scientifically fascinating and complex biological occurrence characterised by morphological and functional changes due to accumulated molecular and cellular damage impairing tissue and organ function. Ageing is often accompanied by cognitive decline but is also the biggest known risk factor for Alzheimer's disease, the most common form of dementia. Emerging evidence suggests that sedentary and unhealthy lifestyles accelerate brain ageing, while regular physical activity, high cardiorespiratory fitness (CRF), or a combination of both, can mitigate cognitive impairment and reduce dementia risk. The purpose of this Review is to explore the neuroprotective mechanisms of endurance exercise and highlight the importance of CRF in promoting healthy brain ageing. Key findings show how CRF mediates the neuroprotective effects of exercise via mechanisms such as improved cerebral blood flow, reduced inflammation, and enhanced neuroplasticity. We summarise evidence supporting the integration of endurance exercise that enhances CRF into public health initiatives as a preventive measure against age-related cognitive decline. Additionally, we address important challenges such as lack of long-term studies with harmonised study designs across preclinical and clinical settings, employing carefully controlled and repeatable exercise protocols, and outline directions for future research.

Proinflammatory cytokines sensitise mesenchymal stromal cells to apoptosis

Mesenchymal stromal cells (MSCs) exert broad therapeutic effects across a range of inflammatory diseases. Their mechanism of action has largely been attributed to paracrine signalling, orchestrated by an array of factors produced by MSCs that are collectively termed the "secretome". Strategies to enhance the release of these soluble factors by pre-exposure to inflammatory cytokines, a concept known as "licensing", is thought to provide a means of enhancing MSC efficacy. Yet, recent evidence shows that intravenously infused MSCs entrapped within the lungs undergo apoptosis, and their subsequent clearance by host phagocytes is essential for their therapeutic efficacy. We therefore sought to clarify the mechanisms governing regulated cell death in MSCs and how exposure to inflammatory cytokines impacts this process. Our results show that MSCs are relatively resistant to cell death induced via the extrinsic pathway of apoptosis, as well as stimuli that induce necroptosis, a form of regulated inflammatory cell death. Instead, efficient killing of MSCs required triggering of the mitochondrial pathway of apoptosis, via inhibition of the pro-survival proteins MCL-1 and BCL-XL. Apoptotic bodies were readily released by MSCs during cell disassembly, a process that was inhibited in vitro and in vivo when the apoptotic effectors BAK and BAX were genetically deleted. Licensing of MSCs by pre-exposure to the inflammatory cytokines TNF and IFN-γ increased the sensitivity of MSCs to intrinsic apoptosis in vitro and accelerated their in vivo clearance by host cells within the lungs after intravenous infusion. Taken together, our study demonstrates that inflammatory "licensing" of MSCs facilitates cell death by increasing their sensitivity to triggers of the intrinsic pathway of apoptosis and accelerating the kinetics of apoptotic cell disassembly.

Variable surface antigen expression, virulence, and persistent infection by Plasmodium falciparum malaria parasites

SUMMARYThe human malaria parasite Plasmodium falciparum is known for its ability to maintain lengthy infections that can extend for over a year. This property is derived from the parasite's capacity to continuously alter the antigens expressed on the surface of the infected red blood cell, thereby avoiding antibody recognition and immune destruction. The primary target of the immune system is an antigen called PfEMP1 that serves as a cell surface receptor and enables infected cells to adhere to the vascular endothelium and thus avoid filtration by the spleen. The parasite's genome encodes approximately 60 antigenically distinct forms of PfEMP1, each encoded by individual members of the multicopy var gene family. This provides the parasite with a repertoire of antigenic types that it systematically cycles through over the course of an infection, thereby maintaining an infection until the repertoire is exhausted. While this model of antigenic variation based on var gene switching explains the dynamics of acute infections in individuals with limited anti-malarial immunity, it fails to explain reports of chronic, asymptomatic infections that can last over a decade. Recent field studies have led to a re-evaluation of previous conclusions regarding the prevalence of chronic infections, and the application of new technologies has provided insights into the molecular mechanisms that enable chronic infections and how these processes evolved.

Hydroxytyrosol as a Mitochondrial Homeostasis Regulator: Implications in Metabolic Syndrome and Related Diseases

Hydroxytyrosol (HT), a principal bioactive phytochemical abundant in Mediterranean dietary sources, has emerged as a molecule of significant scientific interest owing to its multifaceted health-promoting properties. Accumulating evidence suggests that HT's therapeutic potential in metabolic disorders extends beyond conventional antioxidant capacity to encompass mitochondrial regulatory networks. This review synthesizes contemporary evidence from our systematic investigations and the existing literature to delineate HT's comprehensive modulatory effects on mitochondrial homeostasis. We systematically summarized the impact of HT on mitochondrial dynamics (fusion/fission equilibrium), biogenesis and energy metabolism, mitophagy, inter-organellar communication with the endoplasmic reticulum, and microbiota-mitochondria crosstalk. Through this multidimensional analysis, we established HT as a mitochondrial homeostasis modulator with potential therapeutic applications in metabolic syndrome (MetS) and its related pathologies including type 2 diabetes mellitus, obesity-related metabolic dysfunction, dyslipidemia, non-alcoholic steatohepatitis, and hypertension-related complications. Moreover, we further discussed translational challenges in HT research, emphasizing the imperative for direct target identification, mitochondrial-targeted delivery system development, and combinatorial therapeutic strategies. Collectively, this review provides a mechanistic framework for advancing HT research and accelerating its clinical implementation in MetS and its related diseases.

Variant-to-function approaches for adipose tissue: Insights into cardiometabolic disorders

Genome-wide association studies (GWASs) have identified thousands of genetic loci associated with cardiometabolic disorders. However, the functional interpretation of these loci remains a daunting challenge. This is particularly true for adipose tissue, a critical organ in systemic metabolism and the pathogenesis of various cardiometabolic diseases. We discuss how variant-to-function (V2F) approaches are used to elucidate the mechanisms by which GWAS loci increase the risk of cardiometabolic disorders by directly influencing adipose tissue. We outline GWAS traits most likely to harbor adipose-related variants and summarize tools to pinpoint the putative causal variants, genes, and cell types for the associated loci. We explain how large-scale perturbation experiments, coupled with imaging and multi-omics, can be used to screen variants' effects on cellular phenotypes and how these phenotypes can be tied to physiological mechanisms. Lastly, we discuss the challenges and opportunities that lie ahead for V2F research and propose a roadmap for future studies.