Background: The human gastrointestinal tract harbors a complex microbiota that plays a vital role in metabolic health. Dysbiosis of the gut microbiome has been linked to metabolic syndrome (MetS), a growing health concern characterized by obesity, hypertension, and dyslipidemia, all of which are strongly associated with insulin resistance and low-grade inflammation. This study aimed to analyze changes in gut microbiome composition and metabolic parameters in individuals with MetS following a 3-month shared medical appointment program driven by a patient-centered agenda with an emphasis on lifestyle pillars of diet, activity, sleep, and stress management. Methods: Thirty-six individuals with MetS were recruited. Of these, 14 completed a structured metabolic health program with facilitated group appointments, including personalized dietary adjustments, increased physical activity, stress management, and clinical monitoring, while 22 served as an untreated group. Fecal samples were collected for full-length 16S rRNA sequencing. Clinical and biochemical parameters, including body weight, blood pressure, HbA1c, triglycerides, and liver enzymes, were assessed. Microbiome data were analyzed for alpha and beta diversity and differential abundance. Correlations between microbial genera and clinical parameters were evaluated using Spearman correlation. Results: Post-intervention, significant improvements were observed in body weight (p = 0.0061), HbA1c (p = 0.033), triglycerides (p = 0.047), AST (p = 0.016), and systolic blood pressure (p = 0.020). Alpha and beta diversity of the gut microbiome showed no significant changes. However, differential abundance analysis revealed increased levels of butyrate-producing and anti-inflammatory genera including Duncaniella, Megasphaera, Pseudoruminococcus, and Oliverpabstia. Conclusions: A 3-month lifestyle intervention in individuals with MetS was associated with marked improvements in metabolic health and beneficial shifts in gut microbiota composition. These findings suggest that even small lifestyle modifications may be a potential therapeutic target for metabolic syndrome management, highlighting the need for personalized approaches in future research.

Metabolic syndrome (MetS) associated with Osteoarthritis (OA) is an increasingly recognised entity. Whilst the degenerative pattern in cuff-tear arthropathy (CTA) has been well documented, the biological processes behind primary shoulder OA and CTA remain less understood. This study investigates transcriptomic differences in these conditions, alongside the impact of MetS in patients undergoing total shoulder replacement. In a multi-centre study, 20 OA patients undergoing total shoulder replacement were included based on specific treatment indications for OA and cuff-tear arthropathy as well as 25 patients undergoing rotator cuff repair (RCR) as a comparator group. Tissues from subchondral bone, capsule (OA and RCR), and synovium were biopsied, and RNA sequencing was performed using Illumina platforms. Differential gene expression was conducted using DESeq2, adjusting for demographic factors, followed by pathway enrichment using the mitch package. Gene expressions in CTA and primary OA was differentially affected. CTA showed mitochondrial dysfunction, GATD3A downregulation, and increased cartilage degradation, while primary OA was marked by upregulated inflammatory and catabolic pathways. The effect of MetS on these pathologies was further shown. MetS further disrupted WNT/β-catenin signalling in CTA, and in OA. Genes such as ACAN, PANX3, CLU, and VAT1L were upregulated, highlighting potential biomarkers for early OA detection. This transcriptomic analysis reveals key differences between end-stage CTA and primary glenohumeral OA. CTA shows heightened metabolic/protein synthesis activity with less immune-driven inflammation. Under MetS, mitochondrial dysfunction (including GATD3A downregulation) and altered Wnt/β-catenin signalling intensify cartilage and bone damage. In contrast, primary OA features strong complement activation, inflammatory gene expression, and collagen remodelling. MetS worsens both conditions via oxidative stress, advanced glycation end products, and ECM disruption—particularly, increased CS/DS degradation. These distinctions support targeted treatments, from antioxidants and Wnt modulators to aggrecanase inhibitors or clusterin augmentation. Addressing specific molecular disruptions, especially those amplified by MetS, may preserve shoulder function, delay surgical intervention, and improve long-term patient outcomes.

The protein kinase D (PKD) family of three highly homologous isoforms (PKD1, PKD2, and PKD3) is implicated as nutrient sensing signaling kinases that regulate the response of adipose and other tissues to the nutrient environment. However, the physiological role of adipose tissue PKD and its downstream cellular signaling targets are not well characterized. Here, we used phosphoproteomics that was performed to elucidate signaling events downstream of PKD activation in differentiated 3T3-L1 adipocytes using a triple isoform siRNA knockdown model. This revealed PKD-regulated pathways including insulin and cAMP signaling, which control metabolic responses in adipose tissue. An adipose tissue-specific and inducible dominant negative PKD (atDNPKD) mouse model that achieves functional inhibition of all three PKD isoforms was generated to assess the function of adipose PKD on whole body metabolism in vivo in both male and female mice. Insulin-stimulated suppression of lipolysis was blunted in male, but not in female, atDNPKD mice compared with control mice. Female, but not male, atDNPKD mice had higher fasting insulin but normal insulin action. Male atDNPKD mice showed greater sensitivity to the β3-adrenergic receptor agonist CL316,243 on measures of lipolysis and energy expenditure and displayed greater fat oxidation during fasting. During refeeding, male atDNPKD mice consumed less food and took longer to regain body weight that was lost during fasting. These effects were not observed in female mice. These findings indicate that PKD provides sex-dependent fine-tuning control of cAMP signaling in adipose tissue which is important for the coordination of energy balance during fasting and refeeding. NEW & NOTEWORTHY The protein kinase D (PKD) family is a target for the treatment of obesity-related disorders. However, the physiological role of PKD in adipose tissue remains to be resolved. Using phosphoproteomics and an adipose tissue PKD loss-of-function mouse model, results demonstrate that PKD provides fine-tuning of metabolic signaling in adipose tissue and metabolic responses to fasting and refeeding challenges, via coordination of feeding behavior and regulation of body weight.

BACKGROUND:Rotator cuff tears are a leading cause of shoulder pain and dysfunction, with variable healing after rotator cuff repair. Predicting tendon healing remains challenging, with failure rates reaching 21% at 2 years. This study employs transcriptomic analysis to identify gene pathways associated with tendon healing, with clinical and radiological correlation at 2 years postoperatively. METHODS:A prospective multicenter laboratory-based and clinical study of 25 patients undergoing arthroscopic rotator cuff repair was conducted. Intraoperative biopsies were taken from the torn rotator cuff tendon, RNA sequencing was performed, and differential gene expression was analyzed using DESeq2. Functional pathway enrichment was assessed via Reactome and the mitch Bioconductor package. Patient-reported outcome measures, including Oxford Shoulder Score, Quick Disabilities of the Arm, Shoulder and Hand score, and EuroQol Visual Analog Scale, were collected at baseline, 3 months, 12 months, and 2 years. At 2 years, tendons were classified as intact or torn based on standardized gray scale ultrasound, interpreted by experienced musculoskeletal sonographers. Intact tendons showed no visible discontinuity, cleft, or delamination. RESULTS:Both intact (67%) and torn groups (33%) showed significant patient-reported outcome measure improvements, with no statistically significant differences between groups. The torn group experienced an early decline in EuroQol Visual Analog Scale scores, recovering by 12 months and stabilizing by 2 years, while the intact group maintained stable scores. Transcriptomic analysis revealed distinct differences: intact tendons showed increased activity in DNA repair and extracellular matrix (ECM) stabilization pathways, alongside reduced inflammation and enhanced metabolism. In contrast, torn tendons exhibited ongoing inflammation and impaired ECM remodeling. CONCLUSION:Rotator cuff healing involves suppression of inflammation and activation of reparative transcriptional, metabolic, and ECM pathways. Nonhealing tendons display persistent stress, disrupted fibrinolysis, and epigenetic dysregulation. Key molecular signals, including forkhead box O, histone demethylases, zinc transport, matrix metalloproteinases, and SERPINE1, represent promising biomarker candidates for risk stratification and targeted therapy. While transcriptomics remains investigational, these findings support a precision surgery approach, with future integration of molecular diagnostics to personalize treatment and reduce retear risk.

The glucose transporter GLUT4 is integral for optimal skeletal muscle performance during exercise, as well as for metabolic health. Physiological regulation of GLUT4 translocation during exercise and increased GLUT4 expression following exercise involves multiple, redundant signalling pathways. These include effects of reactive oxygen species (ROS). ROS contribute to GLUT4 translocation that increases skeletal muscle glucose uptake during exercise and stimulate signalling pathways that increase GLUT4 expression. Conversely, ROS can also inhibit GLUT4 translocation and expression in metabolic disease states. The opposing roles of ROS in GLUT4 regulation are ultimately linked to the metabolic state of skeletal muscle and the intricate mechanisms involved give insights into pathways critical for exercise performance and implicated in metabolic health and disease.

Excessive body weight is associated with many chronic metabolic diseases and weight loss, so far, remains the gold standard treatment. However, despite tremendous efforts exploring optimal treatments for obesity, many individuals find losing weight and maintaining a healthy body weight difficult. Weight loss is often not sustainable resulting in weight regain and subsequent efforts to lose weight. This cyclic pattern of weight loss and regain is termed “yoyo dieting” and predisposes individuals to obesity and metabolic comorbidities. How yoyo dieting might worsen obesity complications during the weight recurrence phase remains unclear. In particular, there is limited data on the role of the gut microbiome in yoyo dieting. Gut health distress, especially gut inflammation and microbiome perturbation, is strongly associated with metabolic dysfunction and disturbance of energy homeostasis in obesity. In this review, we summarise current evidence of the crosstalk between the gastrointestinal system and energy balance, and the effects of yoyo dieting on gut inflammation and gut microbiota reshaping. Finally, we focus on the potential effects of post-dieting weight loss in improving gut health and identify current knowledge gaps within the field, including gut-derived peptide hormones and their potential suitability as targets to combat weight regain, and how yoyo dieting and associated changes in the microbiome affect the gut barrier and the enteric nervous system, which largely remain to be determined.

Obesity causes a range of tissue dysfunctions that increases the risk for morbidity and mortality. Protein kinase D (PKD) represents a family of stress-activated intracellular signalling proteins that regulate essential processes such as cell proliferation and differentiation, cell survival, and exocytosis. Evidence suggests that PKD regulates the cellular adaptations to the obese environment in metabolically important tissues and drives the development of a variety of diseases. This review explores the role that PKD plays in tissue dysfunction in obesity, with special consideration of the development of obesity-mediated cardiomyopathy, a distinct cardiovascular disease that occurs in the absence of common comorbidities and leads to eventual heart failure and death. The downstream mechanisms mediated by PKD that could contribute to dysfunctions observed in the heart and other metabolically important tissues in obesity, and the predicted cell types involved are discussed to suggest potential targets for the development of therapeutics against obesity-related disease.

Cyclic weight loss and subsequent regain after dieting and non-dieting periods, a phenomenon termed yoyo dieting, places individuals at greater risk of metabolic complications and alters gut microbiome composition. Resistant starch (RS) improves gut health and systemic metabolism. This study aimed to investigate the effect of yoyo dieting and RS on the metabolism and gut microbiome. C57BL/6 mice were assigned to 6 diets for 20 weeks, including control, high fat (HF), yoyo (alternating HF and control diets every 5 weeks), control with RS, HF with RS, and yoyo with RS. Metabolic outcomes and microbiota profiling using 16S rRNA sequencing were examined. Yoyo dieting resulted in short–term weight loss, which led to improved liver health and insulin tolerance but also a greater rate of weight gain compared to continuous HF feeding, as well as a different microbiota profile that was in an intermediate configuration between the control and HF states. Mice fed HF and yoyo diets supplemented with RS gained less weight than those fed without RS. RS supplementation in yoyo mice appeared to shift the gut microbiota composition closer to the control state. In conclusion, yoyo dieting leads to obesity relapse, and increased RS intake reduces weight gain and might help prevent rapid weight regain via gut microbiome restoration.

Abstract Objective Osteoarthritis (OA) is a disease impacting the synovial joint complex, yet transcriptional changes specific to shoulder OA remain underexplored. This study aims to profile transcriptomic changes in periarticular tissues from patients undergoing shoulder replacement for OA. By correlating these profiles with QuickDASH scores—a validated measure of worsening shoulder function—this research seeks to understand the gene expression changes associated with clinical decline. Capsular tissue biopsies from shoulder OA patients were compared with those from a control group undergoing shoulder stabilization for recurrent instability. This investigation forms part of a larger transcriptomic analysis of painful shoulder conditions which will address the current gap in knowledge regarding the molecular and genetic underpinnings of shoulder OA, rotator cuff tears and cuff-tear arthropathy. Results The analysis revealed that genes most strongly associated with increasing QuickDASH scores across tissues were linked to inflammation and stress response. Key pathways involved interleukins, chemokines, complement components, nuclear response factors, and immediate early response genes, reflecting a balance between pro- and anti-inflammatory signalling. Additionally, this study identified unique gene expression patterns in shoulder OA not previously observed in hip and knee OA, along with novel genes implicated in shoulder OA, highlighting areas for future targeted investigation. Trial registration This investigation has been registered with the Australian New Zealand Clinical Trials Registry (ANZCTR), registered on the 26th of March 2018, registration number: 12618000431224, accessible from: https://anzctr.org.au/Trial/Registration/TrialReview.aspx?id=374665&isReview=true

There are epidemiological associations between obesity and type 2 diabetes, cardiovascular disease and Alzheimer’s disease. The role of amyloid beta 42 (Aβ 42 ) in these diverse chronic diseases is obscure. Here we show that adipose tissue releases Aβ 42 , which is increased from adipose tissue of male mice with obesity and is associated with higher plasma Aβ 42 . Increasing circulating Aβ 42 levels in male mice without obesity has no effect on systemic glucose homeostasis but has obesity-like effects on the heart, including reduced cardiac glucose clearance and impaired cardiac function. The closely related Aβ 40 isoform does not have these same effects on the heart. Administration of an Aβ-neutralising antibody prevents obesity-induced cardiac dysfunction and hypertrophy. Furthermore, Aβ-neutralising antibody administration in established obesity prevents further deterioration of cardiac function. Multi-contrast transcriptomic analyses reveal that Aβ 42 impacts pathways of mitochondrial metabolism and exposure of cardiomyocytes to Aβ 42 inhibits mitochondrial complex I. These data reveal a role for systemic Aβ 42 in the development of cardiac disease in obesity and suggest that therapeutics designed for Alzheimer’s disease could be effective in combating obesity-induced heart failure.

Development of OA (OA) is multifactorial and is strongly associated with risk factors such as aging, trauma, metabolic disorders, and obesity. Metabolic Syndrome (MetS)-associated OA, collectively coined MetS-OA, is an increasingly recognized entity in which metabolic disorders and low-grade inflammation play a key mechanistic role in the disruption of joint homeostasis and cartilage degradation. Although there have been enormous efforts to discover biomarkers of MetS and OA, studies investigating a pathophysiological link between MetS and OA are relatively limited, and no serum blood marker has proved diagnostic so far. OA biomarkers that are necessary to discriminate and diagnose early disease remain to be elicited, explained in part by limited prospective studies, and therefore limited tools available to utilize in any prognostic capacity. Biomarker validation projects have been established by the Biomarker Consortium to determine biochemical markers demonstrating predictive validity for knee OA. Given that the metabolic constituents of MetS are treatable to varying extents, it stands to reason that treating these, and monitoring such treatment, may help to mitigate deleterious links with OA development. This narrative review will describe the current state of biomarker identification and utility in OA associated with MetS. We discuss the pathophysiological mechanisms of disease according to constituent pathologies of MetS and how identification of biomarkers may guide future investigation of novel targets.

Lipotoxicity, the accumulation of lipids in non-adipose tissues, alters the metabolic transcriptome and mitochondrial metabolism in skeletal muscle. The mechanisms involved remain poorly understood. Here we show that lipotoxicity increased histone deacetylase 4 (HDAC4) and histone deacetylase 5 (HDAC5), which reduced the expression of metabolic genes and oxidative metabolism in skeletal muscle, resulting in increased non-oxidative glucose metabolism. This metabolic reprogramming was also associated with impaired apoptosis and ferroptosis responses, and preserved muscle cell viability in response to lipotoxicity. Mechanistically, increased HDAC4 and 5 decreased acetylation of p53 at K120, a modification required for transcriptional activation of apoptosis. Redox drivers of ferroptosis derived from oxidative metabolism were also reduced. The relevance of this pathway was demonstrated by overexpression of loss-of-function HDAC4 and HDAC5 mutants in skeletal muscle of obese db/db mice, which enhanced oxidative metabolic capacity, increased apoptosis and ferroptosis and reduced muscle mass. This study identifies HDAC4 and HDAC5 as repressors of skeletal muscle oxidative metabolism, which is linked to inhibition of cell death pathways and preservation of muscle integrity in response to lipotoxicity.

XLS file 72K, Table describing the 300 genes whose mRNA expression were most significantly changed by vemurafenib treatment in A375 cells

OBJECTIVES:The aim of this study was to repurpose a drug for the treatment of bipolar depression.METHODS:A gene expression signature representing the overall transcriptomic effects of a cocktail of drugs widely prescribed to treat bipolar disorder was generated using human neuronal-like (NT2-N) cells. A compound library of 960 approved, off-patent drugs were then screened to identify those drugs that affect transcription most similar to the effects of the bipolar depression drug cocktail. For mechanistic studies, peripheral blood mononuclear cells were obtained from a healthy subject and reprogrammed into induced pluripotent stem cells, which were then differentiated into co-cultured neurons and astrocytes. Efficacy studies were conducted in two animal models of depressive-like behaviours (Flinders Sensitive Line rats and social isolation with chronic restraint stress rats).RESULTS:The screen identified trimetazidine as a potential drug for repurposing. Trimetazidine alters metabolic processes to increase ATP production, which is thought to be deficient in bipolar depression. We showed that trimetazidine increased mitochondrial respiration in cultured human neuronal-like cells. Transcriptomic analysis in induced pluripotent stem cell-derived neuron/astrocyte co-cultures suggested additional mechanisms of action via the focal adhesion and MAPK signalling pathways. In two different rodent models of depressive-like behaviours, trimetazidine exhibited antidepressant-like activity with reduced anhedonia and reduced immobility in the forced swim test.CONCLUSION:Collectively our data support the repurposing of trimetazidine for the treatment of bipolar depression.

PDF file 658K, Supplementary Methods

PDF file 3260K, Supplementary figures and tables

A deficiency in hydrogen sulfide has been implicated in the development and progression of diabetic chronic kidney disease. The purpose of this study was to determine the effect of diabetes on the H2S system in early-stage diabetic kidney disease. We characterised gene and protein expression profile of the enzymes that regulate H2S production and degradation, and H2S production capacity, in the kidney from 10-week-old C57BL6Jdb/db mice (n = 6), in age-matched heterozygous controls (n = 7), and in primary endothelial cells (HUVECs) exposed to high glucose. In db/db mice, renal H2S levels were significantly reduced (P = 0.009). Protein expression of the H2S production enzymes was differentially affected by diabetes: cystathionine β-synthase (CBS) was significantly lower in both db/db mice and high glucose-treated HUVECs (P < 0.0001; P = 0.0318) whereas 3-mercatopyruvate sulfurtransferase (3-MST) expression was higher in the db/db kidney (P < 0.0001), yet lower in the HUVECs (P = 0.0001). Diabetes had no effect on the expression of cystathionine γ-lyase (CSE) in the db/db kidney (P = ns) but was associated with reduced expression in the HUVECs (P = 0.0004). Protein expression of degradation enzyme sulfide quinone reductase (SQOR) was significantly higher in db/db kidney (P = 0.048) and lower in the high glucose-treated HUVECs (P = 0.008). Immunofluorescence studies revealed differential localisation of the H2S enzymes in the kidney, including both tubular and vascular localisation, suggestive of functionally distinct actions in the kidney. The results of this study provide foundational knowledge for future research looking at the H2S system in both kidney physiology and the aetiology of chronic diabetic kidney disease.

Schizophrenia (SCZ) is a complex neuropsychiatric disorder associated with altered bioenergetic pathways and mitochondrial dysfunction. Antipsychotic medications, both first and second-generation, are commonly prescribed to manage SCZ symptoms, but their direct impact on mitochondrial function remains poorly understood. In this study, we investigated the effects of commonly prescribed antipsychotics on bioenergetic pathways in cultured neurons. We examined the impact of risperidone, aripiprazole, amisulpride, and clozapine on gene expression, mitochondrial bioenergetic profile, and targeted metabolomics after 24-h treatment, using RNA-seq, Seahorse XF24 Flux Analyser, and gas chromatography–mass spectrometry (GC–MS), respectively. Risperidone treatment reduced the expression of genes involved in oxidative phosphorylation, the tricarboxylic acid cycle, and glycolysis pathways, and it showed a tendency to decrease basal mitochondrial respiration. Aripiprazole led to dose-dependent reductions in various mitochondrial function parameters without significantly affecting gene expression. Aripiprazole, amisulpride and clozapine treatment showed an effect on the tricarboxylic acid cycle metabolism, leading to more abundant metabolite levels. Antipsychotic drug effects on mitochondrial function in SCZ are multifaceted. While some drugs have greater effects on gene expression, others appear to exert their effects through enzymatic post-translational or allosteric modification of enzymatic activity. Understanding these effects is crucial for optimising treatment strategies for SCZ. Novel therapeutic interventions targeting energy metabolism by post-transcriptional pathways might be more effective as these can more directly and efficiently regulate energy production.

XLS file 118K, Table listing gene sets identified by GSEA as significantly enriched in control versus vemurafenib treated A375 cells (FDR>0.25)

Altered protein synthesis has been implicated in the pathophysiology of several neuropsychiatric disorders, particularly schizophrenia. Ribosomes are the machinery responsible for protein synthesis. However, there remains little information on whether current psychotropic drugs affect ribosomes and contribute to their therapeutic effects. We treated human neuronal-like (NT2-N) cells with amisulpride (10 µM), aripiprazole (0.1 µM), clozapine (10 µM), lamotrigine (50 µM), lithium (2.5 mM), quetiapine (50 µM), risperidone (0.1 µM), valproate (0.5 mM) or vehicle control for 24 h. Transcriptomic and gene set enrichment analysis (GSEA) identified that the ribosomal pathway was altered by these drugs. We found that three of the eight drugs tested significantly decreased ribosomal gene expression, whilst one increased it. Most changes were observed in the components of cytosolic ribosomes and not mitochondrial ribosomes. Protein synthesis assays revealed that aripiprazole, clozapine and lithium all decreased protein synthesis. Several currently prescribed psychotropic drugs seem to impact ribosomal gene expression and protein synthesis. This suggests the possibility of using protein synthesis inhibitors as novel therapeutic agents for neuropsychiatric disorders.