Effects of combined aerobic and resistance exercise on sarcopenia in elderly patients with type 2 diabetes mellitus
Aerobic exercise and resistance exercise have been shown to improve sarcopenia. However, whether combining aerobic and resistance exercise could alleviate sarcopenia symptoms in patients with type 2 diabetes mellitus (T2DM) complicated with sarcopenia remains unclear. This 12-week randomized controlled trial enrolled older patients with T2DM and sarcopenia, diagnosed by grip strength, appendicular skeletal muscle mass index (ASMI), and the Short Physical Performance Battery (SPPB). Participants were randomized to an exercise group (aerobic plus resistance training) or a control group receiving health education. Physical function was evaluated with the 6-minute walk and Timed Up-and-Go tests. Serum 25(OH)D3 was measured by liquid chromatography-tandem mass spectrometry, and irisin by enzyme-linked immunosorbent assay. Before the intervention, there were no differences in baseline characteristics between the non-intervention and intervention groups. However, grip strength and ASMI significantly increased in patients in the intervention group after receiving combined aerobics and resistance exercise. Moreover, functional physical fitness also improved in the intervention group after the intervention. Additionally, the sarcopenia-associated factors, including Irisin and 25(OH)D3, increased significantly in patients with T2DM complicated with sarcopenia following the intervention. Overall, combined aerobics and resistance exercise may help alleviate sarcopenia in patients with T2DM.
Seven days of strength training reprogram the hydroxymethylation in visceral adipose tissue of obese Swiss mice
Excessive accumulation of visceral adipose tissue induced by a high-fat diet promotes epigenetic modifications in DNA, increasing Nfkb transcription and pro-inflammatory cytokine synthesis. This study evaluated the epigenetic effects of obesity and seven days of strength exercise on DNA demethylation in the Nfkb transcription region. Swiss mice were divided into three groups: lean controls (CT = 6), obese sedentary (OB = 6), and obese strength training (OBexT = 6). OB and OBexT received a high-fat diet (59% lipids) for fourteen weeks; OBexT performed daily climbing sessions for seven days. OB animals showed higher pro-inflammatory cytokine expression and NFKB protein content in mesenteric adipose (mean ± SD: OB = 4.35 ± 3.37; OBexT = 0.59 ± 0.28; CT = 1.00 ± 0.70), with significant reduction after training (p < 0.05; η2 = 0.502). Pairwise comparison revealed a large effect size between OB and OBexT (d = 1.57). Demethylation in adipose tissue was elevated in OB mice, increasing gene availability and Nfkb transcription (OB = 4.01 ± 1.23; OBexT = 1.70 ± 1.06; CT = 0.99 ± 0.22), with a strong reduction post-exercise (p < 0.01; η2 = 0.6546; d = 2.01). This reduction limited gene accessibility for Nfkbp65 phosphorylation, highlighting epigenetic modulation. These results demonstrate, for the first time, that only seven sessions of strength training can reprogram epigenetic marks in mesenteric adipose tissue, attenuating transcription of inflammatory mediators during an obesogenic state. Collectively, our findings support strength training as an effective short-term epigenetic regulator of inflammatory gene expression in adipose tissue.
PTEN regulation by miR-486-5p contributes to the amelioration of polycystic ovary syndrome
This research intended to identify the genes related to PCOS (polycystic ovary syndrome) and verify the regulatory function of miR-486-5p as well as its target PTEN in granulosa cells (GCs). RT-qPCR was used to detect the expression of miR-486-5p in the serum, follicular fluid (FF), and GCs of PCOS patients and normal subjects. ROC curve analysis indicated strong diagnostic performance. Bioinformatic analysis via miRDB and ENCORI databases predicted PTEN as a potential target of miR-486-5p; this prediction was validated through dual-luciferase reporter gene assays. Meanwhile, a series of functional assays were performed. Cellular proliferation capacity was quantitatively assessed using the CCK8 assay, while flow cytometry was used to determine cell apoptosis ratio. The secretion of pro-inflammatory mediators was quantitatively measured employing an ELISA kit. miR-486-5p was found to be reduced in serum from patients, as well as in patient FF and GCs. The enhanced expression of miR-486-5p strengthened the proliferation of GCs and suppressed apoptotic activity, while concurrently attenuating pro-inflammatory cytokine secretion. Conversely, miR-486-5p inhibitor yielded opposing effects. Further investigation revealed that PTEN functioned as a negative regulatory factor of miR-486-5p. The increase of miR-486-5p caused a significant down-regulation of PTEN mRNA expression. Forced expression of PTEN reversed the cellular effects induced by miR-486-5p, including the enhanced proliferation rate, suppressed apoptosis, and attenuated inflammatory response. miR-486-5p can inhibit cell apoptosis and secretion of inflammatory factors by negatively regulating the expression of target gene PTEN, suggesting that miR-486-5p may be a potential target for PCOS.
Pathomechanisms, genetic insights, and therapeutics in diabetes-associated dementia
Type 2 diabetes (T2DM) significantly increases the risk of dementia due to overlapping metabolic, molecular, and genetic factors. This review comprehensively analyzes the pathophysiological links between diabetes and cognitive decline, focusing on chronic hyperglycemia, insulin resistance, oxidative stress, mitochondrial dysfunction, neuroinflammation, and cerebrovascular complications. Key genetic and epigenetic contributors to diabetes-associated dementia (DAD), including variations in APOE, PICALM, SORL1, and GSK3B, are discussed. The roles of pathological proteins such as amyloid-beta (Aβ) and hyperphosphorylated tau in neurodegeneration are also highlighted. Preclinical and clinical evidence supports targeting insulin signaling pathways, oxidative damage, and inflammatory responses as potential therapeutic strategies. Promising therapies, including GLP-1 receptor agonists, SGLT2 inhibitors, DPP-4 inhibitors, and anti-inflammatory drugs, are reviewed alongside emerging approaches such as gene therapy, stem cell therapy, and immunomodulation. Despite encouraging advances, the clinical translation of these therapies remains challenging due to the complexity of DAD pathogenesis. This review aims to advance understanding of diabetes-induced cognitive impairment and guide the development of personalized dementia therapies by integrating molecular, genetic, and clinical insights. Future research should focus on elucidating the precise molecular mechanisms of DAD progression and on developing targeted, patient-specific therapeutic interventions to overcome translational barriers.
Estrogenic prevention of luteinizing hormone releasing hormone agonist-induced bone loss
Prostate cancer is a leading cause of death. As a hormone-driven cancer, prostate cancer is often treated with drugs (luteinizing hormone receptor agonists; LHRHa) or surgical approaches (orchidectomy; ORX) with the goal of reducing androgens. These approaches cause side effects such as bone loss. It is unclear if the side effects of these approaches are due to loss of androgens or loss of estrogens, as these approaches reduce both. We seek to evaluate if LHRHa and ORX have equivalent effects on bone, if the bone loss can be ameliorated by estrogen supplementation, and if estrogen supplementation alone is sufficient to improve bone mass while reducing androgen production. Herein, we evaluated bone microarchitecture, mechanical properties, and the cellular mechanism of LHRHa with subsequent hormone add-back on bone. We find that LHRHa negatively affects bone microarchitecture but has more mild effects on bone than ORX. Estrogen supplementation - but not androgen supplementation - improves bone mass and strength in mice treated with LHRHa. Estrogen supplementation alone is also sufficient to improve bone mass and strength while also reducing androgen production. However, estrogen supplementation also increases osteoblast and osteoclast activity, which may promote prostate cancer metastasis in bone. Future studies should evaluate estrogen as a modulator of the metastatic niche.
ERRATUM: Effects of dipeptidyl peptidase-4 inhibitor in insulin-resistant rats with myocardial infarction
Thyroxine does not improve skeletal muscle regeneration after injury in aged mice
Thyroid hormone levels decrease with aging, and low thyroxine levels are correlated to sarcopenia development. While thyroid hormone stimulates myogenesis in young subjects, its effect on aged muscle regeneration is unclear. We aimed to investigate the impact of a low dose of thyroxine (T4) replacement therapy (7.5 ng/g body weight) on tibial anterior regeneration seven days after injury by 1.2% BaCl2 injection in 24-27-month-old male mice. Our primary data suggest that regenerating aged skeletal muscle exhibits local resistance to thyroid hormone action without altering myogenic regulatory factors expression. However, T4 treatment decreases the number of central nuclei, indicative of newformed fibers. Also, we observed decrease in cross-sectional area and increases myonuclei domain, cell death and laminin expression in T4 treatment injured muscles. Rather than improving regeneration, T4 replacement therapy appears to induce atrophy and tissue remodelling. Our data highlight the need to understand aging physiology since thyroid hormones are crucial for muscle regeneration in young animals, although T4 replacement therapy does not improve muscle regeneration post-injury in elderly mice. This research may support clinical recommendations against treating sarcopenic patients with subclinical hypothyroidism, especially following fall-related injuries.
Triptolide impedes high glucose-induced cell function in HK2 cells through PRKN-mediated ubiquitination of ACSL1
Triptolide (TP), a bioactive compound, demonstrates efficacy in ameliorating diabetic nephropathy (DN). This study aimed to investigate the role of TP in renal tubular injury during DN and elucidate the underlying mechanism involving acyl-CoA synthetase long-chain family member 1 (ACSL1) and parkin (PRKN). DN model was induced in HK2 cells by high glucose (HG, 30 mmol/L). Cell counting kit-8, EdU assay, flow cytometry were used to assess cell viability, proliferation, and apoptosis. Inflammatory cytokines were measured via enzyme-linked immunosorbent assay. Ferroptosis was assessed by detecting reactive oxygen species (ROS), lipid peroxidation (MDA), Fe2+, and glutathione (GSH) using kits. The mRNA and protein examination was performed by real-time quantitative PCR and western blotting. Co-immunoprecipitation assay was conducted for protein interaction and ubiquitination detection. DN in mice was established by high-fat diet and streptozocin injection. The effects of TP on mice were analyzed by histopathology analysis, biochemical analysis, and protein detection. TP mitigated HG-induced apoptosis, inflammation, and ferroptosis in HK2 cells. The protective effects of TP against HG-induced injury in HK2 cells were mediated by the inhibition of ACSL1. PRKN promoted ubiquitination of ACSL1 to reduce the protein level of ACSL1. PRKN/ACSL1 inhibited HG-induced HK2 cell dysfunction. The protective effect of TP in HG-stimulated HK2 cells was mediated by the upregulation of PRKN. TP activated anti-ferroptosis NRF2/SLC7A11/GPX4 pathway by targeting ACSL1. TP could ameliorate kidney injury in DN mice through modulating PRKN, ACSL1, and NRF2/SLC7A11/GPX4 pathway. All these discoveries suggested that TP protected HK2 cells from HG-triggered kidney injury through upregulating PRKN that further promoted ubiquitination of ACSL1.
Phenotypic variations in polycystic ovary syndrome: metabolic risks and emerging biomarkers
Polycystic ovary syndrome (PCOS) is a heterogeneous endocrine disorder with diverse clinical manifestations and metabolic risks. The 2012 NIH phenotypic classification, based on the presence of hyperandrogenism (HA), ovulatory dysfunction, and polycystic ovarian morphology (PCOM), has enabled more nuanced characterization of PCOS into four phenotypes (A-D). Phenotypes A and B, both hyperandrogenic and anovulatory, are consistently associated with the highest metabolic risk, including insulin resistance, dyslipidemia, and increased prevalence of metabolic syndrome. Phenotype C, though ovulatory, still exhibits metabolic abnormalities due to androgen excess. In contrast, phenotype D, lacking hyperandrogenism, generally shows the mildest hormonal and metabolic profiles. This review outlines the evolving diagnostic landscape of PCOS, including the potential use of anti-Müllerian hormone (AMH) as a surrogate marker for PCOM. It explores hormonal and metabolic biomarkers, such as total and free testosterone, SHBG, LH/FSH ratio, HOMA-IR, and lipid parameters, in phenotype differentiation. Furthermore, emerging adipokines (e.g., adiponectin, chemerin, and ZAG) and inflammatory markers (e.g., CRP, IL-6, and TNF-α) provide additional insight into the metabolic heterogeneity of PCOS beyond obesity. Genetic and genomic studies have identified over 19 susceptibility loci involved in gonadotropin regulation, steroidogenesis, and insulin signaling, with distinct gene clusters aligning with adiposity, insulin resistance, and reproductive traits. MicroRNA signatures also show potential as phenotype-specific biomarkers. Recognizing phenotype-specific variations in PCOS is critical for individualized risk assessment and therapeutic strategies. Future research should prioritize standardized diagnostic criteria and large, diverse cohorts to validate emerging biomarkers and improve long-term outcomes for women with PCOS.
Developmental regulation of fetal mitochondrial respiratory function towards term: the role of glucocorticoid and thyroid hormones
Mitochondria are unique intracellular organelles that have their own DNA and are inherited intact in the oocyte. They have multiple functions, the most important of which is producing energy in the form of ATP by oxidative phosphorylation (OXPHOS) using a range of metabolic substrates. As energy requirements increase with intrauterine growth and the onset of new postnatal functions at birth, mitochondria develop structurally and functionally in utero to meet these energy demands. In part, the developmental and prepartum maturational changes in mitochondrial OXPHOS capacity depend on the endocrine environment and the natural rise in the fetal concentrations of hormones, such as cortisol and tri-iodothyronine (T3), towards term. This review discusses the development of mitochondrial respiratory function during late gestation with an emphasis on tissue OXPHOS capacity. It considers the role of cortisol and thyroid hormones, in particular, in the intrauterine development and prepartum maturation of mitochondrial OXPHOS capacity in preparation for extrauterine life. Finally, it briefly examines the potential longer-term consequences of abnormal hormonal exposure before birth on mitochondrial OXPHOS function later in postnatal life. Endocrine regulation of mitochondrial OXPHOS in the fetus is shown to be multifactorial, dynamic and tissue specific with a central role in determining functional development. It optimises energetics for survival both in utero and at birth and has implications for adult metabolic fitness and the inheritance of mitochondrial phenotype.
Lactobacillus johnsonii N6.2 improves glycemia and reduces diabetes-induced organ injury in the db/db mice model
Diabetes mellitus is a complex metabolic disorder characterized by hyperglycemia and the associated comorbidities. Type 2 diabetes is also associated with the dysfunction of liver, kidney and nervous system. In addition, an altered microbiota is frequently observed in subjects with type 2 diabetes. In this study, a db/db (diabetic) mouse model of type 2 diabetes was used to elucidate the beneficial effects of the probiotic Lactobacillus johnsonii N6.2. To evaluate metabolic effects, we performed metabolomics on liver samples, and RNA-seq from the liver and visceral adipose tissue, followed by qRT-PCR validation. Using L. johnsonii N6.2 extracellular vesicles, we evaluated lipid accumulation in hepatocytes. Finally, the gut microbiome of db/db mice was profiled using 16S rRNA sequencing. We observed that administration of the probiotic improved glycemic levels and decreased diabetes scores and type 2 diabetes-associated injury to the pancreas, liver and kidneys. Liver metabolomic and transcriptome analyses identified biomarkers of L. johnsonii N6.2 activity, including modulation of the vitamin K pathway, upregulation of FGF21, a key regulator of glucose and lipid metabolism, and alternations in selected circadian genes. This study elucidates the beneficial effects of L. johnsonii N6.2, against the common symptoms of type 2 diabetes, highlighting its potential as an adjuvant therapeutic agent.
A TIMELESS link to dedifferentiation in thyroid cancer
TIMELESS is considered a molecular hinge linking circadian rhythms and the cell cycle. We recently identified TIMELESS as one of the upregulated core circadian clock genes during thyroid cancer dedifferentiation, but its expression and significance in thyroid cancer remain unclear. To address this, we assessed TIMELESS expression in thyroid neoplasms using bioinformatics analysis, immunoblotting, and immunohistochemistry. TIMELESS expression progressively increased from normal thyroid tissue to differentiated thyroid cancer and then to anaplastic thyroid cancer. Silencing TIMELESS expression in thyroid cancer cells reduced clonogenicity and spheroid formation, induced G2/M cell cycle arrest, and impeded xenograft growth in NOD SCID mice. In The Cancer Genome Atlas, TIMELESS expression was negatively correlated with recombination proficiency scores. Knocking down TIMELESS increased sensitivity to doxorubicin in thyroid cancer cells and upregulated the mRNA expression of NKX2-1 and SLC5A5. In conclusion, the overexpression of TIMELESS is associated with thyroid cancer dedifferentiation and may serve as a potential target for combination therapies.
Single-cell analysis of oxidative phosphorylation protein expression in pancreatic islets in type 2 diabetes
Mitochondrial dysfunction is a key feature of type 2 diabetes and is closely linked to ageing, a major risk factor for the disease. This study investigated islet cell composition and mitochondrial oxidative phosphorylation protein expression in pancreatic tissue from older donors (≥62 years) with and without type 2 diabetes, matched for age, sex, and BMI. Fixed human pancreatic tissue sections were immunolabelled for insulin, glucagon, NDUFB8 (complex I), MTCO1 (complex IV), and VDAC1 (a mitochondrial mass marker) to quantify islet composition and mitochondrial protein levels. A machine learning-based single-cell segmentation pipeline enabled high-resolution profiling of individual cell populations within islets. In type 2 diabetes, islets exhibited an increased alpha:beta cell ratio, altered spatial organisation with fewer beta-beta and more alpha-alpha interactions, and a significantly higher proportion of bi-hormonal cells co-expressing insulin and glucagon. Within beta cells, we observed significant changes in mitochondrial protein expression, including reduced complex I and elevated complex IV levels. Unsupervised clustering of mitochondrial expression patterns identified three distinct beta cell expression clusters. Donors with type 2 diabetes showed a marked shift in the distribution of beta cells across clusters, with increased proportions of beta cells exhibiting low complex I and high complex IV expression. These results highlight significant alterations in islet architecture and mitochondrial protein expression associated with type 2 diabetes, providing new insights into the mechanisms underlying type 2 diabetes.
Ambient Temperature Modulates the Effects of Peripheral Y1R Antagonism on Diet-induced Obesity and Glucose Intolerance
The neuropeptide Y1 receptor (Y1R) plays a key role in metabolic regulation, and its peripheral antagonism has shown promise in promoting weight loss and improving glucose metabolism. However, most studies are conducted at room temperature (RT, 21-22°C), where mild cold stress stimulates sympathetic nervous system (SNS) activation. The impact of Y1R blockade under thermoneutral (TN, 30°C) conditions, which eliminate cold stress, remains unclear. In this study, we investigated the effects of BIBO3304 on body weight, energy expenditure (EE), and glucose metabolism in chow- and high-fat diet (HFD)-fed mice housed at TN and compared the results with RT. We found that at RT, BIBO3304 significantly reduced body weight gain and fat mass while increasing EE and fat oxidation. These effects were abolished under TN, where SNS activation is minimized, leading to no changes in body composition or EE. Despite this, BIBO3304 improved glucose tolerance at TN, particularly in the early phase (week 2), independent of insulin sensitivity. However, these glucose-lowering effects diminished by week 6, suggesting a potential SNS-dependent mechanism for long-term benefits. TN-housed mice exhibited greater glucose excursions and reduced insulin sensitivity compared to RT-housed mice, highlighting the impact of ambient temperature on metabolic regulation. In summary, these findings suggest that BIBO3304's effects on energy balance are SNS-dependent, whereas its glucose-lowering benefits persist transiently at TN. This highlights the need to consider environmental temperature in the evaluation of pharmacological interventions for obesity and diabetes, with potential implications for climate-adjusted dosing strategies.
In vivo effects of cadmium on signaling and secretion of pituitary gonadotrophs in male mice are time-dependent
Cadmium is a heavy metal found widely in the environment, originating from industrial emissions, mining activities, phosphate fertilizers, and cigarette smoke. It is an endocrine-disrupting chemical that mimics essential metals such as calcium and zinc, interfering with hormone signaling. Due to its long biological half-life, cadmium bioaccumulates in organisms, raising concerns about its long-term effects on endocrine and reproductive health. Cadmium's reproductive toxicity is well documented, with studies highlighting its impact on gonadotropin regulation and testicular function. However, its specific effects on calcium (Ca2+) signaling in gonadotrophs remain poorly understood. This study aims to determine whether cadmium disrupts Ca2+-dependent signaling mechanisms essential for gonadotropin secretion. To address this, we used an adult male mouse model to assess pituitary cadmium accumulation, gonadotroph responsiveness to GnRH, and alterations in Ca2+ mobilization patterns. Our results show that cadmium exposure leads to pituitary bioaccumulation, prolonged endocrine disruption, and gonadotroph hyperplasia. Initially, gonadotroph responsiveness to GnRH declines, but over time, altered Ca2+ oscillation patterns and increased gonadotropin secretion emerge. A transition from normal oscillatory Ca2+ signaling to biphasic responses was observed, along with sustained phospholipase C-β (PLCβ) activation, suggesting persistent intracellular signaling disruptions. In addition, cadmium exposure resulted in testicular atrophy, increased apoptosis, and reduced sperm count. Testosterone levels declined, while the gonadotroph population increased, highlighting an imbalance in endocrine regulation. These findings suggest that cadmium induces reproductive toxicity through a combination of direct testicular damage and disruption of gonadotroph calcium signaling and hormone secretion, leading to testicular dysfunction that is relevant to public health.
RISING STARS: Effects of a GLP-1 receptor polymorphism on responses to liraglutide
The rs6923761 (Gly168Ser) missense variant in the glucagon-like peptide-1 receptor (GLP-1R) has been associated with favorable anthropometric and metabolic parameters in individuals with obesity but decreased responsiveness to incretin-based therapies. Here, we performed a pre-specified analysis of a randomized-controlled trial in individuals with obesity and pre-diabetes comparing treatment with the GLP-1R agonist liraglutide, the dipeptidyl peptidase 4 inhibitor sitagliptin or hypocaloric diet, and evaluated the effects of the rs6923761 variant on outcomes. We found significantly greater weight loss to liraglutide with each copy of the variant allele present, indicating a gene dose effect. In addition, individuals with the variant allele exhibited a significant reduction in the pro-thrombotic and pro-inflammatory factor plasminogen activator inhibitor-1 after liraglutide treatment. There was no effect of genotype on fasting glucose after liraglutide treatment, yet individuals with the variant allele exhibited decreased responsiveness to liraglutide and hypocaloric diet in measurements of fasting insulin, C-peptide, glucagon, and HOMA-IR. In conclusion, we found that the GLP-1R rs6923761 variant exerts a dual impact on liraglutide efficacy-enhancing weight loss while diminishing metabolic benefits. The observed associations could be consistent with the constitutive activation of the GLP-1R in the presence of this variant with reduced activation/signaling in response to pharmacologic agents, a pattern that has been observed with the rs10305492 variant in animal models. Future studies are needed to investigate the molecular mechanisms of associations with the rs6923761 variant.
Intrauterine triclosan exposure disrupts hypothalamus-pituitary-thyroid axis function in offspring rats
Triclosan (TCS), an antimicrobial agent widely used in personal care products, has been associated with impaired thyroid function and reduced thyroid hormone (TH) levels. However, its potential role in the developmental programming of thyroid dysfunction remains unclear. This study investigated the long-term effects of intrauterine TCS exposure on the hypothalamic-pituitary-thyroid (HPT) axis in adult rat offspring. Pregnant Wistar rats received oral doses of corn oil (control) or TCS (10 or 30 mg/kg/day) throughout gestation. Offspring rats were euthanized on postnatal day 90 (PND90), and tissues from the hypothalamus, pituitary, thyroid, liver, and serum were collected for analysis. Gene and protein expression were evaluated by RT-qPCR and Western blotting; thyroid histology was assessed morphologically; global DNA methylation was measured by ELISA; and serum TSH and THs were quantified through immunoassays. TCS exposure altered hypothalamic TRH content, reduced Gh mRNA expression in the pituitary, and decreased serum TSH levels. In the thyroid, Slc5a5, Tg, Tpo, Tshr, Pax8, and Nkx2.1 were downregulated, accompanied by reduced NIS and TPO protein expression and decreased circulating T4 levels. Histological analyses revealed reduced follicular diameter in both sexes. Epigenetic changes included increased global DNA methylation and H3 histone methylation in both sexes, along with reduced H3 acetylation in males. In addition, TCS exposure altered hepatic enzymes involved in TH metabolism, indicating systemic endocrine disruption. Collectively, these findings demonstrate that intrauterine TCS exposure increases susceptibility to thyroid hypofunction in adulthood, highlighting its potential role as a developmental thyroid disruptor.
Muscle-bone biochemical crosstalk in osteosarcopenia: focusing on mechanisms and potential therapeutic strategies
Osteosarcopenia (OS) is a syndrome defined by the concurrent presence of sarcopenia and osteoporosis in the elderly population, which markedly elevates the risk of falls, fractures, and mortality. Recent studies demonstrate that disruption of muscle-bone biochemical crosstalk emerges as a key driver of OS pathogenesis, and that targeting pivotal mediators and pathways can concurrently restore musculoskeletal homeostasis. However, the precise molecular mechanisms and targeted therapeutic strategies remain inadequately explored. This review systematically summarizes the epidemiological risk factors and pathophysiological mechanisms underpinning OS, with emphasis on the interplay within musculoskeletal metabolism among myokines (e.g., fibroblast growth factors 21, FGF21, and irisin), osteokines (e.g., osteocalcin, OCN, receptor activator of nuclear factor-κB ligand, RANKL, and sclerostin, SOST), adipokines, and shared signaling pathways such as mitochondria-associated axes, Wnt/β-catenin, and nuclear factor-κB (NF-κB), as well as discusses the potential efficacy of direct and indirect interventions targeting these factors and biochemical signals, which provides innovative strategies and prospective research directions for developing precision-targeted therapies against OS and other degenerative musculoskeletal disorders. In addition, we propose that precise modulation of muscle-bone signaling constitutes a promising approach to treat OS. Future efforts should prioritize standardizing diagnostic criteria and advancing the development of therapies targeting critical muscle-bone biochemical interaction nodes to optimize the management of musculoskeletal comorbidities in the aging population.
CL316,243 and skeletal muscle metabolism: role of sex and estrogen receptor beta
CL316,243 (CL), a beta 3 adrenergic receptor (B3-AR) agonist, has 'exercise mimetic' effects in adipose tissue. CL may also positively affect skeletal muscle (SM), yet the role of estrogen receptor beta (ERβ) in mediating SM-specific effects of CL is not known. We investigated the effects of CL on SM metabolism, as well as the role played by ERβ. High-fat diet-fed male and female wild-type (WT) and ERβ DBD knockout (KO) mice were administered CL daily for 2 weeks. Quadriceps SM protein markers of fatty acid oxidation (FatOx), protein synthesis, and protein catabolism were assessed. CL increased relative lean mass in both sexes (P = 0.012). In females, CL increased FatOx in WT, yet reduced FatOx in KO, while among males, CL reduced FatOx independent of genotype (P = 0.04). Uncoupling protein 2 (UCP2) and fatty acid synthase (FASN) abundance were higher in females (P = 0.004 and 0.037, respectively), and in both sexes, KO mice had higher SM UCP2 abundance (P = 0.022). CL increased phosphorylated acetyl-CoA carboxylase in males, yet reduced it in females (P = 0.015). Similarly, CL affected p706S kinase abundance (indicative of anabolic signaling) in a sexually dimorphic manner, increasing in males and decreasing in females. CL robustly increased SM FASN across sexes and genotypes (P < 0.001). In summary, the most salient finding was that CL increased SM FASN content independent of sex and ERβ genomic activity; additional novel sex-divergent effects of CL on SM metabolism were identified, some of which were affected by ERβ genomic activity.
Dysbiosis in the upper airway and gut, and altered urine metabolome in Malaysian diabetic patients
Gut dysbiosis and an increased risk of respiratory infection in type 2 diabetes have been well recognised. However, the relationship between the gut and respiratory pathobiont carriage rates in the type 2 diabetic Malaysian population is understudied. To address the knowledge gap, we profiled the gut and upper respiratory tract (URT) microbial composition, and the urine metabolome of 31 type 2 diabetic adults and 14 non-diabetic adults. We showed a higher prevalence of opportunistic URT pathogens in diabetes patients. A higher abundance of pro-inflammatory bacteria Escherichia coli was detected in the gut of the diabetic subjects. This coincided with the higher levels of sorbitol and taurine in the urine. The former is produced by aldose reductase, an enzyme strongly associated with airway inflammation, while the latter is a substrate for bacterial antioxidants (i.e. H2S). Despite a small sample size, our study revealed the potential relationship between the carriage rates of URT pathobionts with the gut microbial and urine metabolomic profiles of diabetes patients.
Effects of metformin and Denosumab on bone and glucose metabolism in postmenopausal women with OP and OA
Diabetic osteoporosis is a metabolic disease that seriously endangers human health and Previous studies have found that denosumab and metformin have certain effects on bone metabolism and glucose metabolism, respectively. However, there is still a lack of relevant research on the effect of the combined use of two drugs. In this study, we sought to analyze the therapeutic effect of these two drugs combined on the glycemic and bone metabolic parameters in the treatment of type 2 diabetes with postmenopausal osteoporosis. A prospective cohort study was designed to include 537 cases of patients with type 2 diabetes with postmenopausal osteoporosis. Patients were treated with placebo alone (placebo, n=135), metformin alone (MET, n=132), denosumab alone (DEN, n=136), and the combination group (n=134) for 30 months. Baseline data at 10 months, 20 months, and 30 months, Dual Energy X-ray Absorptiometry (DEXA), and pQCT were used to identify spine and tibia bone microstructures, respectively. The combination therapy group demonstrated significantly greater improvements in bone mineral density (tibia, radius, spine, and whole body) and bone microstructure (tibia and radius) compared to MET or DEN monotherapy (P<0.05). Bone absorption markers such as CTX and ALP were decreased, the level of bone formation markers was further increased, and the progression of glucose metabolism was improved significantly (P<0.05) compared to DEN alone or using MET alone. Denosumab monotherapy (DEN) ameliorated bone loss while exerting modest effects on glucose metabolism progression. In contrast, metformin monotherapy (MET) significantly improved glycemic control but demonstrated limited efficacy against bone loss. Crucially, the metformin-denosumab combination synergistically mitigated bone loss in diabetic postmenopausal osteoporosis patients.
