Insulin Signaling Research Articles

Comparative transcriptomic and metabolomic analysis of FTO knockout and wild-type porcine iliac artery endothelial cells.

The fat mass and obesity associated (FTO) gene, previously identified as a pivotal genetic locus associated with adiposity, has recently been linked to various cancers. In this study, we established an FTO knockout (KO) cell line in porcine iliac artery endothelial cells (PIECs) utilizing CRISPR/Cas9 technology to systematically investigate the gene's function and effect through transcriptomic and metabolomic analysis. Our results revealed significant gene expression and metabolic profiles differences between the FTO KO and wild-type (WT) cells. Furthermore, enrichment analysis highlighted the involvement of differentially expressed genes in metabolic processes, cellular components, and molecular functions, as well as in complement and coagulation cascades, mineral absorption, glutathione metabolism, insulin signaling, fluid shear stress, and atherosclerosis pathways. The metabolomic profiling revealed clear distinctions between the FTO KO and WT cells, indicating profound modifications in cellular metabolism. Correlation analysis of transcriptomic and metabolomic data revealed a significant association between six metabolites and twenty genes, with melatonin showing specific correlations with the expression of several genes, indicating a complex regulatory network between gene expression and metabolic changes. This study provides a foundation for further research on the FTO gene's role in cellular processes and molecular mechanisms underlying physiological and pathological conditions.

Friend or foe: the paradoxical roles of MG53 in diabetes mellitus.

MG53 is predominantly expressed in striated muscles. The role of MG53 in diabetes mellitus has been gradually elucidated but is still full of controversy. Some reports have indicated that MG53 is upregulated in animal models with metabolic disorders, and that muscle-specific MG53 upregulation is sufficient to induce whole-body insulin resistance and metabolic syndrome through targeting both the insulin receptor (IR) and IR substrate-1 (IRS-1) for ubiquitin-dependent degradation. Additionally, MG53 has been identified as a myokine/cardiokine that is secreted from striated muscles into the bloodstream and circulating MG53 has further been shown to trigger insulin resistance by binding to the extracellular domain of the IR, thereby allosterically inhibiting insulin signaling. Conversely, other studies have reported findings that contradict these results. Specifically, no significant change in MG53 expression in striated muscles or serum has been observed in diabetic models, and the MG53-mediated degradation of IRS-1 may be insufficient to induce insulin resistance due to the compensatory roles of other IRS subtypes. Furthermore, sustained elevation of MG53 levels in serum or systemic administration of recombinant human MG53 (rhMG53) has shown no impact on metabolic function. In this review, we will fully characterize these two disparate views, strive to provide critical insights into their contrasts and propose several specific experimental approaches that may yield additional evidence. Our goal is to encourage the scientific community to elucidate the effects of MG53 on metabolic diseases and the molecular mechanisms involved, thereby providing the theoretical basis for the treatment of metabolic diseases and the applications of rhMG53.

Abstract 4138745: Blockade of Mineralocorticoid Receptor by Esaxerenone Improves Insulin Sensitivity in Obese Mice

Background: Aldosterone regulates blood pressure and electrolyte balance. However, overactivation of the mineralocorticoid receptor (MR) and elevated aldosterone levels are implicated in the pathogenesis of cardiometabolic disorders, though the underlying mechanisms are not fully understood. In this study, we investigated whether a novel, non-steroidal selective MR blocker, esaxerenone, ameliorates the development of metabolic disorders in obese mice models and examined the underlying mechanism. Methods: Esaxerenone (3 mg/kg/day) was orally administered to high-fat diet (HFD)-fed C57BL/6J or normal chow-fed db/db mice. Metabolic parameters, tissue morphology, and effects of esaxerenone on insulin sensitivity were assessed. Gene expression and insulin signaling, determined by Akt phosphorylation, were examined using quantitative RT-PCR and western blotting, respectively. In in-vitro experiments, insulin targets cell lines such as 3T3-L1 adipocytes, HepG2 cells, and C2C12 myotubes were used. Insulin-responsive cells were treated with 10 nM or 100 nM esaxerenone or eplerenone for 30 minutes before 4-hour 1000 nM aldosterone stimulation. Insulin signaling was assessed 15 minutes after stimulation with 17 nM insulin. Results: Esaxerenone improved insulin sensitivity (P<0.05) without altering metabolic parameters in HFD-induced obese and db/db mice. Esaxerenone suppressed fat accumulation, adipocyte size, and liver lipid droplets compared with the vehicle-treated group (P<0.01). In adipose tissue, esaxerenone reduced macrophage infiltration (P<0.01) and the expression of inflammatory molecules (P<0.05). In in-vitro experiments, aldosterone significantly decreased the expression levels of PPARγ and adiponectin in 3T3-L1 adipocytes. Moreover, aldosterone attenuated insulin-induced Akt phosphorylation in 3T3-L1 adipocytes, HepG2 cells, and C2C12 myotubes in a dose-dependent manner (P<0.01). Pretreatment with esaxerenone reversed the effect of aldosterone, whereas eplerenone, an MR antagonist, did not show a similar effect at the same dose. Conclusion: Inhibition of MR by esaxerenone improved insulin sensitivity in HFD-induced obese and genetically diabetic mice. The reduction of inflammation and fat accumulation and enhancement of insulin signaling were suggested to be underlying mechanisms. Esaxerenone might be a beneficial therapeutic approach for managing metabolic disorders.

Abstract 4145829: Fatty Acid Binding Protein 4 as Potential Indicator for Gestational Diabetes Mellitus-Induced Fetal Endothelial Dysfunction

Introduction/Background: Gestational diabetes mellitus (GDM) is the most common complication during pregnancy. GDM is leading to an elevated risk for the development of cardiovascular diseases both in the mother and the child in later life. Previous studies have identified fatty acid-binding protein 4 (FABP4) as a prime candidate involved in the pathophysiology of GDM. Indeed, women with GDM exhibit elevated blood levels of FABP4, suggesting its potential role as a biomarker for endothelial dysfunction and cardiovascular risk assessment in GDM. Research Question/Hypothesis: Does FABP4 affect the function of human endothelial cells from patients with GDM? Goals/Aim: Our aim is a better understanding of the role of FABP4 in fetal endothelial dysfunction of patients with GDM and the development of potential therapeutic strategies. Methods/Approach: Primary human umbilical vein endothelial cells (HUVECs) were isolated from umbilical cords obtained from normoglycemic and GDM pregnancies. Total mRNA from HUVECs was used for bulk RNA sequencing to compare gene expression pattern. HUVECs were subjected to functional analyses assessing proliferation, migration, NO and insulin signaling. Finally, human endothelial cells were exposed to high laminar flow (30 dyn/cm 2 ) or simvastatin (10 nM) treatment to investigate their impact on FABP4 expression and endothelial function. Results/Data: Bulk RNA sequencing data analysis revealed FABP4 as a gene overexpressed in GDM HUVECs compared to normoglycemic controls. Gene set enrichment analysis showed in addition an enrichment of genes involved in angiogenesis and Notch signaling pathways in human endothelial cells from GDM patients. GDM HUVECs had a significantly higher wound healing capacity compared to normoglycemic controls. The PI3K/AKT/mTOR pathway was enriched in GDM HUVECs. GDM HUVECs displayed impaired activation of AKT and eNOS (expression and phosphorylation) after stimulation with insulin, suggesting a possible insulin resistance. Finally, subjecting HUVECs to high laminar shear stress or simvastatin treatment caused a reduction of FABP4 mRNA expression and an increase of eNOS expression, indicating potential therapeutic strategies to improve endothelial function. Conclusions: We provided evidence that FABP4 could be involved in fetal GDM-induced endothelial dysfunction. High laminar shear stress and medications activating eNOS signaling could protect the endothelium against the negative impact of FABP4 in GDM.

Hepatic SerpinA1 improves energy and glucose metabolism through regulation of preadipocyte proliferation and UCP1 expression.

Lipodystrophy and obesity are associated with insulin resistance and metabolic syndrome accompanied by fat tissue dysregulation. Here, we show that serine protease inhibitor A1 (SerpinA1) expression in the liver is increased during recovery from lipodystrophy caused by the adipocyte-specific loss of insulin signaling in mice. SerpinA1 induces the proliferation of white and brown preadipocytes and increases the expression of uncoupling protein 1 (UCP1) to promote mitochondrial activation in mature white and brown adipocytes. Liver-specific SerpinA1 transgenic mice exhibit increased browning of adipose tissues, leading to increased energy expenditure, reduced adiposity and improved glucose tolerance. Conversely, SerpinA1 knockout mice exhibit decreased adipocyte mitochondrial function, impaired thermogenesis, obesity, and systemic insulin resistance. SerpinA1 forms a complex with the Eph receptor B2 and regulates its downstream signaling in adipocytes. These results demonstrate that SerpinA1 is an important hepatokine that improves obesity, energy expenditure and glucose metabolism by promoting preadipocyte proliferation and activating mitochondrial UCP1 expression in adipocytes.

Research progress in molecular mechanism of acupuncture for diabetes mellitus

This paper discusses the mechanism of acupuncture for diabetes mellitus from the perspective of molecular biology, aiming to reveal the potential rules of restoring the balance in the body and fighting against diabetes mellitus (DM). By searching the basic research literature of acupuncture treatment for DM, it is found that the molecular biological mechanism of acupuncture treatment for DM is closely related to the regulation of insulin signaling pathway, the modulation of inflammatory response, the protection and regeneration of islet β-cells, fat metabolism and energy balance. It points out that there are few studies of acupuncture on the type 1 diabetes mellitus and the large-scale randomized controlled trials, as well as the studies on the upstream regulation mechanism, the specific cellular molecules and the interaction mechanism of various molecules. It needs to deepen the multi-level, multi-target and multi-dimensional exploration on the molecular biological mechanism of acupuncture for diabetes mellitus.

Mapping Protein Conformational Landscapes from Crystallographic Drug Fragment Screens.

Proteins are dynamic macromolecules. Knowledge of a protein's thermally accessible conformations is critical to determining important transitions and designing therapeutics. Accessible conformations are highly constrained by a protein's structure such that concerted structural changes due to external perturbations likely track intrinsic conformational transitions. These transitions can be thought of as paths through a conformational landscape. Crystallographic drug fragment screens are high-throughput perturbation experiments, in which thousands of crystals of a drug target are soaked with small-molecule drug precursors (fragments) and examined for fragment binding, mapping potential drug binding sites on the target protein. Here, we describe an open-source Python package, COnformational LAndscape Visualization (COLAV), to infer conformational landscapes from such large-scale crystallographic perturbation studies. We apply COLAV to drug fragment screens of two medically important systems: protein tyrosine phosphatase 1B (PTP1B), which regulates insulin signaling, and the SARS CoV-2 Main Protease (MPro). With enough fragment-bound structures, we find that such drug screens enable detailed mapping of proteins' conformational landscapes.

Association between selenium biomarkers and insulin resistance in women with obesity: A case-control study.

Although literature demonstrates controversial results regarding the association between selenium and glucose metabolism, no studies have specifically targeted a population with obesity even though this group is vulnerable to insulin resistance. To evaluate the association between selenium biomarkers and insulin resistance in women with obesity. This case-control study recruited 84 women with obesity and 129 with healthy weight (control). Selenium intake was assessed by 3-day food record. Selenium concentration in plasma, erythrocyte, and urine was assessed by inductively coupled plasma optical emission spectrometry. Serum glucose, insulin, and glycated hemoglobin (HbA1c) were assessed in a fasting blood sample. Homeostasis Model Assessment of Beta Cell Function (HOMA-β) and Homeostasis Model Assessment of Insulin Resistance were calculated according to standard methods. Women with obesity had higher dietary selenium intake in comparison to the control group (p < 0.001). Further, the plasma and erythrocyte concentrations were lower in individuals with obesity (p < 0.001), while selenium in urine was higher (p < 0.001) than in controls. No significant differences in insulin resistance markers were observed between groups. Selenium intake was positively associated with HOMA-β in both groups. In women with obesity, selenium intake was also positively associated with insulin and HbA1c, while in the controls the clearance of selenium was negatively associated with insulin and HbA1c. There was a positive correlation between dietary selenium intake, fasting insulin, HbA1c, and HOMA-β (p < 0.05). Women with obesity present impaired selenium metabolism. Further, we observed an association between dietary selenium and markers of insulin resistance, which may reflect the possible negative action of selenium on insulin signaling.

Omentin increases glucose uptake, but not insulin sensitivity in human myotubes dependent on extracellular lactotransferrin.

Omentin (intelectin-1) is an adipokine produced by the stromal vascular fraction of visceral adipose tissue and has been positively associated with insulin sensitivity. The underlying mechanism of action, however, is largely unknown. It has been described that omentin may increase insulin sensitivity and glucose uptake of adipocytes, but effects on other insulin-sensitive tissues such as skeletal muscle are unexplored. We therefore investigated effects of omentin on insulin sensitivity and metabolism of primary human myotubes. Primary human myotubes were treated with 0.5 or 2 µg/mL omentin and subsequently protein detection, glucose uptake assay, lactate assay and lipidomics analysis were performed. Omentin did not affect skeletal muscle insulin signaling, as assessed by basal and insulin-stimulated phosphorylation of IRS1 and AKT. Omentin increased basal, but not insulin-stimulated glucose uptake. While increased glycolytic activity was confirmed by elevated lactate release after omentin treatment, effects on cellular lipid composition were limited to an increase in total triacylglycerol concentration. Increased glucose uptake by omentin was counteracted by addition of extracellular lactotransferrin, which can bind to omentin. Overall, increased basal glucose uptake in skeletal muscle cells suggests differential effects of omentin on insulin-sensitive tissues. Moreover, an involvement of lactotransferrin in omentin's mechanism of action may partially explain contradictory results of epidemiological studies on the role of omentin in different diseases.

Expression profile of tsRNAs in white adipose tissue of vitamin D deficiency young male mice with or without obesity

The expression of tsRNA in white adipose tissue (WAT) of VD deficiency male mice with obesity has not been reported. The healthy male C57BL/6J mice aged 4-6 weeks were divided into 4 groups according to the VD3 and fat energy supplement in daily diets. The qPCR verification further demonstrated that tRF5-20-HisGTG-3 were significantly up-regulated and mt-tRF3a-ProTGG was significantly down-regulated not only in HFVDD vs HFVDS, but aslo in HFVDD vs ConVDS. tRF5-22-CysGCA-27 were significantly up-regulated and mt-5'tiRNA-32-SerTGA, mt-5'tiRNA-33-SerTGA and mt-5'tiRNA-33-AlaTGC was significantly down-regulated only in HFVDD vs ConVDS. Enrichment analysis of the qPCR verified DE tsRNAs showed that the 3 up-regulated tsRNAs seemed to be associated with FoxO signaling pathway, GnRH secretion, 2−Oxocarboxylic acid metabolism, Autophagy-animal, Glucagon and insulin signaling pathway, while 4 down-regulated tsRNA seemed to be associated with cell communication, primary metabolic process, metabolic process, response to stimulus, multicellular organismal process, cellular metabolic process, cellular process and biological regulation. The tsRNAs were differentially expressed in VD deficiency with obesity, especially tRF5-20-HisGTG-3, tRF5-22-CysGCA-27, tRF3a-GlyGCC-1, mt-5'tiRNA-33-AlaTGC, mt-5'tiRNA-33-SerTGA, mt-5'tiRNA-32-SerTGA and mt-tRF3a-ProTGG. These tsRNAs seemed to be associated with FoxO signaling pathway, GnRH secretion, 2−oxocarboxylic acid metabolism, autophagy, glucagon and insulin signaling pathway, metabolic process and biological regulation.

Generation of Functioning Platelets from Mature Megakaryocytes Derived from CD34+ Umbilical Cord Blood Cells.

Clinically patients with thrombocytopenia are in urgent need of platelet transfusion, thus it is necessary to produce the platelets in large scale in vitro to meet the clinical needs. In this study, we developed efficient protocol to generate functioning platelets by differentiating umbilical cord blood (CB)-derived CD34+ cells into mature megakaryocytes. Under our condition, up to 85% of mature megakaryocytes were generated from CB-derived CD34+ cells, and over 75% CD42b+CD62p+ platelets were produced. The megakaryocytes at day 12 after the differentiation had the similar gene expression pattern to natural mature megakaryocytes, and AMPK and insulin signal pathway were activated to inhibit the apoptosis and benefit platelet release. There were up to 72% of the platelets that could bind with PAC1, which is the highest rate of CB CD34+ cell-derived platelets to play function in vitro to date. The recovery of hemostasis and coagulation was similar in thrombocytopenia mice injected with CB CD34+ cell-derived platelets and with human blood-derived platelets, respectively, and it is the first time to demonstrate that human CB CD34+ cell-derived platelets were functional invivo. Therefore, our findings open a new avenue to provide an in vitro efficient approach to generate functional platelets for clinical applications.

Avenanthramides Ameliorate Insulin Resistance by Modulating Gluconeogenesis and Glycogen Synthesis in HepG2 Cells.

Diabetes mellitus (DM) is a multifaceted metabolic condition, mainly defined by elevated blood glucose levels. A feature of type 2 DM includes insulin resistance (IR), which involves impairments within the insulin signaling pathways. Avenanthramides (AVNs) are phenolic alkaloids found in Avena sativa L. The major AVNs are AVN A, AVN B, and AVN C. They have been reported to offer benefits in preventing inflammation, cancer, and cardiovascular diseases. However, the effects of AVNs on the liver glucose metabolism pathways remain unknown. This study examined the effects and underlying mechanisms through which AVNs alleviate IR induced by free fatty acid (FFA) in HepG2 cells. The results indicated that FFA treatment significantly decreased glucose consumption by 34.54% compared to the control. However, treatments with AVN A, B, and C at 100 μM increased glucose uptake by 57.93%, 58.28%, and 53.10%, respectively, compared to FFA treatment alone. This effect occurs through the increased expression of glucose transporter 4. Furthermore, AVNs significantly enhanced the glycogen content. AVNs induced increased phosphorylation of insulin receptor substrate-1 (IRS-1), phosphatidylinositol-3-kinase (PI3K), and protein kinase B (Akt). AVNs treatment decreased the levels of phosphoenolpyruvate carboxykinase and glucose-6-phosphatase in HepG2 cells. This effect was attributed to AMP-activated protein kinase activation and inhibition of forkhead box protein O1. Collectively, these results suggest that AVNs regulate glucose metabolism by activating the IRS-1/PI3K/Akt pathway, which is related to glycogen synthesis, and by inhibiting key molecules that promote gluconeogenesis.

Impact of high-fructose diet and metformin on histomorphological and molecular parameters of reproductive organs and vaginal microbiota of female rat

There are limited data on the effects of a high-fructose diet on the female reproductive system. Although metformin has some functional effects on female fertility, its reproductive outcome on high fructose diet-induced metabolic syndrome is unclear. The aim of the present study is to evaluate the impact of a high fructose diet on histomorphological and molecular parameters of the reproductive organs and vaginal microbiota as well as the treatment potential of metformin. Wistar albino rats were used in the study. The metabolic syndrome model was induced by a high-fructose diet in rats for 15 weeks. Metformin was orally administered once a day for the last 6 weeks. The high-fructose diet increased blood glucose, triglycerides, insulin, and ovarian testosterone levels; however, it reduced ovarian aromatase levels and follicle numbers and caused uterine inflammation. The high-fructose diet-induced molecular abnormalities on ovarian tissue were demonstrated by the downregulation of ovarian insulin signaling pathway proteins and dysregulation of ovarian mitogenic and apoptotic pathway proteins. A high-fructose diet caused vaginal dysbiosis, metformin increased probiotic bacteria in the vaginal microbiota. Our results revealed that metformin improves ovarian impairments by modulating hormonal balance, insulin level, mapk, and apoptotic signaling molecules, as well as regulating the vaginal microbiota.

β2-Chimaerin, a GTPase-Activating Protein for Rac1, Is a Novel Regulator of Hepatic Insulin Signaling and Glucose Metabolism

Glucose homeostasis is a complex process regulated by multiple organs and hormones, with insulin playing a central role. Recent evidence underscores the role of small GTP-binding proteins, particularly Rac1, in regulating insulin secretion and glucose uptake. However, the role of Rac1-regulatory proteins in these processes remains largely unexplored. In this study, we investigated the role of β2-chimaerin, a Rac1-specific GTPase-activating protein (GAP), in glucose homeostasis using whole-body β2-chimaerin knockout mice. Our data revealed that β2-chimaerin deficiency results in improved glucose tolerance and enhanced insulin sensitivity in mice. These metabolic effects were associated with increased insulin-induced AKT phosphorylation in the liver and activation of downstream pathways that regulate gluconeogenesis and glycogen synthesis. We show that insulin activates Rac1 in the liver. However, β2-chimaerin deletion did not significantly alter Rac1 activation in this organ, suggesting that β2-chimaerin regulates insulin signaling via a Rac1-independent mechanism. These findings expand our understanding of Rac1 regulation in glucose metabolism, and identify β2-chimaerin as a novel modulator of hepatic insulin signaling, with potential implications for the development of insulin resistance and diabetes.

Microbial metabolism disrupts cytokine activity to impact host immune response

Host-pathogen interactions are shaped by the metabolic status of both the host and pathogen. The host must regulate metabolism to fuel the immune response, while the pathogen must extract metabolic resources from the host to enable its own survival. In this study, we focus on the metabolic interactions of Mycobacterium abscessus with Drosophila melanogaster. We identify MAB_1132c as an asparagine transporter required for pathogenicity in M. abscessus. We show that this requirement is specifically associated with damage to the host: flies infected with MAB_1132c knockout bacteria, or with wild-type bacteria grown in asparagine-restricted conditions, are longer lived without showing a significant change in bacterial load. This is associated with a reduction in the host innate immune response, demonstrated by the decreased transcription of antimicrobial peptides as well as a significant reduction in the ability of the infection to disrupt systemic insulin signaling. Much of the increase in host survival during infection with asparagine-limited M. abscessus can be attributed to alterations in unpaired cytokine signaling. This demonstrates that asparagine transport in M. abscessus prior to infection is not required for replicative fitness in vivo but does significantly influence the interaction with the host immune responses.

Network transformation-based analysis of biochemical systems.

A dynamical system obtains a wide variety of kinetic realizations, which is advantageous for the analysis of biochemical systems. A reaction network, derived from a dynamical system, may or may not possess some properties needed for a thorough analysis. We improve and extend the work of Johnston and Hong et al. on network translations to network transformations, where the network is modified while preserving the dynamical system. These transformations can shrink, extend, or retain the stoichiometric subspace. Here, we show that a positive dependent network can be translated to a weakly reversible network. Using the kinetic realizations of (1) calcium signaling in the olfactory system and (2) metabolic insulin signaling, we demonstrate the benefits of transformed systems with positive deficiency for analyzing biochemical systems. Furthermore, we present an algorithm for a network transformation of a weakly reversible non-complex factorizable kinetic (NFK) system to a weakly reversible complex factorizable kinetic (CFK) system, thereby enhancing the Subspace Coincidence Theorem for NFK systems of Nazareno et al. Finally, using the transformed kinetic realization of monolignol biosynthesis in Populus xylem, we study the structural and kinetic properties of transformed systems, including the invariance of concordance and variation of injectivity and mono-/multi-stationarity under network transformation.

Chebulagic Acid Ameliorates Oxidative Stress and Inflammation via Regulation of Insulin Signaling Pathway in High-Fat Diet/Streptozotocin-Induced Diabetic Rats

Chebulagic Acid Ameliorates Oxidative Stress and Inflammation via Regulation of Insulin Signaling Pathway in High-Fat Diet/Streptozotocin-Induced Diabetic Rats

Microvascular insulin resistance with enhanced muscle glucose disposal in CD36 deficiency.

Microvascular dysfunction contributes to insulin resistance. CD36, a fatty acid transporter and modulator of insulin signalling, is abundant in microvascular endothelial cells. Humans carrying the minor allele (G) of CD36 coding variant rs3211938 have 50% reduced CD36 expression and show endothelial dysfunction. We aimed to determine whether G allele carriers have microvascular resistance to insulin and, if so, how this affects glucose disposal. Our multi-disciplinary approach included hyperinsulinaemic-euglycaemic clamps in Cd36-/- and wild-type mice, and in individuals with 50% CD36 deficiency, together with control counterparts, in addition to primary human-derived microvascular endothelial cells with/without CD36 depletion. Insulin clamps showed that Cd36-/- mice have enhanced insulin-stimulated glucose disposal but reduced vascular compliance and capillary perfusion. Intravital microscopy of the gastrocnemius showed unaltered transcapillary insulin flux. CD36-deficient humans had better insulin-stimulated glucose disposal but insulin-unresponsive microvascular blood volume (MBV). Human microvascular cells depleted of CD36 showed impaired insulin activation of Akt, endothelial NO synthase and NO generation. Thus, in CD36 deficiency, microvascular insulin resistance paradoxically associated with enhanced insulin sensitivity of glucose disposal. CD36 deficiency was previously shown to reduce muscle/heart fatty acid uptake, whereas here we showed that it reduced vascular compliance and the ability of insulin to increase MBV for optimising glucose and oxygen delivery. The muscle and heart respond to these energy challenges by transcriptional remodelling priming the tissue for insulin-stimulated glycolytic flux. Reduced oxygen delivery activating hypoxia-induced factors, endothelial release of growth factors or small intracellular vesicles might mediate this adaptation. Targeting NO bioavailability in CD36 deficiency could benefit the microvasculature and muscle/heart metabolism. Clinicaltrials.gov NCT03012386 DATA AVAILABILITY: The RNAseq data generated in this study have been deposited in the NCBI Gene Expression Omnibus ( www.ncbi.nlm.nih.gov/geo/ ) under accession code GSE235988 ( https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE235988 ).

Insulin Resistance Is a Modifying Factor for Parkinson's Disease.

Parkinson's disease (PD) is the second most common, and the fastest-growing neurodegenerative disorder with unclear etiology in most cases. Therefore, the identification of non-genetic risk factors for PD pathology is crucial to develop effective preventative or therapeutic strategies. An increasing number of evidence suggests that central insulin resistance might have an essential role in PD pathology. Nevertheless, it is not clear whether insulin resistance arises from external factors/lifestyle, comorbidities such as type 2 diabetes or it can occur in a PD patient's brain independently from peripheral insulin resistance. We aimed to investigate insulin resistance and its role in GBA1mutation-associated PD pathogenesis and phenotype severity. Midbrain organoids, generated from induced pluripotent stem cells (iPSCs) of PD patients carrying the GBA1-N370S heterozygous mutation (GBA-PD) and healthy donors, were exposed to different insulin concentrations to modify insulin signaling function. Transcriptomics analysis was performed to explore insulin signaling gene expression patterns in GBA-PD and to find a potential target for GBA-PD-associated phenotype rescue. The insulin signaling pathway genes show dysregulation in GBA-PD. Particularly, we highlight that a knockdown of FOXO1 mitigates the loss of dopaminergic neurons and cellular death in GBA-PD. Additionally, our findings suggest a promising therapeutic potential of the anti-diabetic drug Pioglitazone in decreasing dopaminergic neuron loss associated with GBA-PD. Local insulin signaling dysfunction plays a substantial role in GBA-PD pathogenesis, exacerbating dopaminergic neuron death. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Exploring the Molecular Mechanisms underlying SADI-S Improves Glucose Metabolism in Type 2 Diabetic Rats through Liver Transcriptomics and Proteomics Analysis.

Metabolic surgery could improve or even reverse type 2 diabetes mellitus (T2DM). Single-anastomosis duodenal-ileal bypass with sleeve gastrectomy (SADI-S) is one of the most effective metabolic surgeries for T2DM. However, the molecular mechanisms behind the SADI-S-induced T2DM improvement are not fully understood.Here,T2DM rats received SADI-S and were sacrificed after 8 weeks; the controls received sham surgery; Liver tissues were collected for transcriptomics and proteomics analysis to identify differentially expressed genes (DEGs) and proteins (DEPs). Parallel reaction monitoring (PRM) was performed to validate the accuracy of the proteomics results.SADI-S significantly improved glucose metabolism in T2DM rats.A total of 120 genes/proteins(e.g., phosphoenolpyruvate carboxykinase (Pck1) and pyruvate kinase (Pklr)) exhibited consistent expression trends at both mRNA and protein levels. Among the upregulated genes/proteins involved in glucose metabolic pathways, enrichment was observed in pathways such as the pyruvate metabolic pathway, insulin signaling pathway, glycolysis/gluconeogenesis biological processes, glucagon signaling pathway, and AMPK signaling pathway. Downregulated genes/proteins were enriched in the pyruvate metabolic pathway. The above-mentioned signaling pathways are implicated in glucose metabolism, suggesting a potential mechanism for SADI-S-mediated alleviation of T2DM. The PRM validation results indicated that all selected proteins showed consistent trends between PRM and proteomics data. This consistency suggests the reliability of the proteomics results.