Adipocyte-derived Extracellular Vesicles Research Articles

Visceral Adipocyte-Derived Extracellular Vesicle miR-27a-5p Elicits Glucose Intolerance by Inhibiting Pancreatic β-Cell Insulin Secretion.

Pancreatic β-cell dysfunction caused by obesity can be associated with alterations in the levels of microRNAs (miRNAs). However, the role of miRNAs in such processes remains elusive. Here, we show that pancreatic islet miR-27a-5p, which is markedly increased in obese mice and impairs insulin secretion, is mainly delivered by visceral adipocyte-derived extracellular vesicles (EVs). Depleting miR-27a-5p significantly improves insulin secretion and glucose intolerance in db/db mice. Supporting the function of EVs' miR-27a-5p as a key pathogenic factor, intravenous injection of miR-27a-5p-containing EVs shows their distribution in mouse pancreatic islets. Tracing the injected AAV-miR-27a-5p (AAV-miR-27a) or AAV-FABP4-miR-27a-5p (AAV-FABP4-miR-27a) in visceral fat results in upregulating miR-27a-5p in EVs and serum, and elicits mouse pancreatic β-cell dysfunction. Mechanistically, miR-27a-5p directly targets L-type Ca2+ channel subtype CaV1.2 (Cacna1c) and reduces insulin secretion in β-cells. Overexpressing mouse CaV1.2 largely abolishes the insulin secretion injury induced by miR-27a-5p. These findings reveal a causative role of EVs' miR-27a-5p in visceral adipocyte-mediated pancreatic β-cell dysfunction in obesity-associated type 2 diabetes mellitus.

MicroRNA Profile of Mouse Adipocyte-Derived Extracellular Vesicles.

The post-transcriptional control of gene expression is a complex and evolving field in adipocyte biology, with the premise that the delivery of microRNA (miRNA) species to the obese adipose tissue may facilitate weight loss. Cells shed extracellular vesicles (EVs) that may deliver miRNAs as intercellular messengers. However, we know little about the miRNA profile of EVs secreted by adipocytes during postnatal development. Here, we defined the miRNA cargo of EVs secreted by mouse adipocytes in two distinct phases of development: on postnatal day 6, when adipocytes are lipolytic and thermogenic, and on postnatal day 56, when adipocytes have active lipogenesis. EVs were collected from cell culture supernatants, and their miRNA profile was defined by small RNA sequencing. The most abundant miRNA of mouse adipocyte-derived EVs was mmu-miR-148a-3p. Adipocyte EVs on postnatal day 6 were hallmarked with mmu-miR-98-5p, and some miRNAs were specific to this developmental stage, such as mmu-miR-466i-5p and 12 novel miRNAs. Adipocytes on postnatal day 56 secreted mmu-miR-365-3p, and 16 miRNAs were specific to this developmental stage. The miRNA cargo of adipocyte EVs targeted gene networks of cell proliferation, insulin signaling, interferon response, thermogenesis, and lipogenesis. We provided here a database of miRNAs secreted by developing mouse adipocytes, which may be a tool for further studies on the regulation of gene networks that control mouse adipocyte development.

Extracellular vesicles in tumor-adipose tissue crosstalk: key drivers and therapeutic targets in cancer cachexia

Cancer cachexia is a complex metabolic syndrome characterized by unintentional loss of skeletal muscle and body fat. This syndrome is frequently associated with different types of cancer and negatively affects the prognosis and outcome of these patients. It involves a dynamic interplay between tumor cells and adipose tissue, where tumor-derived extracellular vesicles (EVs) play a crucial role in mediating intercellular communication. Tumor cells release EVs containing bioactive molecules such as hormones (adrenomedullin, PTHrP), pro-inflammatory cytokines (IL-6), and miRNAs (miR-1304-3p, miR-204-5p, miR-155, miR-425-3p, miR-146b-5p, miR-92a-3p), which can trigger lipolysis and induce the browning of white adipocytes contributing to a cancer cachexia phenotype. On the other hand, adipocyte-derived EVs can reprogram the metabolism of tumor cells by transporting fatty acids and enzymes involved in fatty acid oxidation, resulting in tumor growth and progression. These vesicles also carry leptin and key miRNAs (miR-155-5p, miR-10a-3p, miR-30a-3p, miR-32a/b, miR-21), thereby supporting tumor cell proliferation, metastasis formation, and therapy resistance. Understanding the intricate network underlying EV-mediated communication between tumor cells and adipocytes can provide critical insights into the mechanisms driving cancer cachexia. This review consolidates current knowledge on the crosstalk between tumor cells and adipose tissue mediated by EVs and offers valuable insights for future research. It also addresses controversial topics in the field and possible therapeutic approaches to manage cancer cachexia and ultimately improve patient outcomes and quality of life.

Increased secretion of adipocyte-derived extracellular vesicles is associated with adipose tissue inflammation and the mobilization of excess lipid in human obesity

BackgroundObesity is a worldwide epidemic characterized by adipose tissue (AT) inflammation. AT is also a source of extracellular vesicles (EVs) that have recently been implicated in disorders related to metabolic syndrome. However, our understanding of mechanistic aspect of obesity’s impact on EV secretion from human AT remains limited.MethodsWe investigated EVs from human Simpson Golabi Behmel Syndrome (SGBS) adipocytes, and from AT as well as plasma of subjects undergoing bariatric surgery. SGBS cells were treated with TNFα, palmitic acid, and eicosapentaenoic acid. Various analyses, including nanoparticle tracking analysis, electron microscopy, high-resolution confocal microscopy, and gas chromatography–mass spectrometry, were utilized to study EVs. Plasma EVs were analyzed with imaging flow cytometry.ResultsEVs from mature SGBS cells differed significantly in size and quantity compared to preadipocytes, disagreeing with previous findings in mouse adipocytes and indicating that adipogenesis promotes EV secretion in human adipocytes. Inflammatory stimuli also induced EV secretion, and altered EV fatty acid (FA) profiles more than those of cells, suggesting the role of EVs as rapid responders to metabolic shifts. Visceral AT (VAT) exhibited higher EV secretion compared to subcutaneous AT (SAT), with VAT EV counts positively correlating with plasma triacylglycerol (TAG) levels. Notably, the plasma EVs of subjects with obesity contained a higher number of adiponectin-positive EVs than those of lean subjects, further demonstrating higher AT EV secretion in obesity. Moreover, plasma EV counts of people with obesity positively correlated with body mass index and TNF expression in SAT, connecting increased EV secretion with AT expansion and inflammation. Finally, EVs from SGBS adipocytes and AT contained TAGs, and EV secretion increased despite signs of less active lipolytic pathways, indicating that AT EVs could be involved in the mobilization of excess lipids into circulation.ConclusionsWe are the first to provide detailed FA profiles of human AT EVs. We report that AT EV secretion increases in human obesity, implicating their role in TAG transport and association with adverse metabolic parameters, thereby emphasizing their role in metabolic disorders. These findings promote our understanding of the roles that EVs play in human AT biology and metabolic disorders.

The association between the size of adipocyte-derived extracellular vesicles and fasting serum triglyceride-glucose index as proxy measures of adipose tissue insulin resistance in a rat model of early-stage obesity.

Obesity is a complex disease that predisposes individuals to cardiometabolic alterations. It leads to adipose tissue (AT) dysfunction, which triggers insulin resistance (IR). This suggests that people with obesity develop local IR first and systemic IR later. AT secretes extracellular vesicles, which may be physiopathologically associated with the development of IR. Our aim was to evaluate the effect of a high-fat diet on different parameters of adiposity in a rat model of early-stage obesity and to determine if these parameters are associated with markers of systemic IR. In addition, we sought to explore the relationship between fasting blood measures of IR (Triglycerides/High Density Lipoprotein-cholesterol [TAG/HDL-c] and Triglycerides-Glucose Index [TyG Index]) with the size of adipocyte-derived extracellular vesicles (adEV). We used a model of diet-induced obesity for ten weeks in Wistar rats exposed to a high-fat diet. Final weight gain was analyzed by Dual X-ray absorptiometry. Visceral obesity was measured as epididymal AT weight. IR was evaluated with fasting TyG Index & TAG/HDL-c, and adEV were isolated from mature adipocytes on ceiling culture. In the high-fat diet group, glucose and triglyceride blood concentrations were higher in comparison to the control group (Log2FC, 0.5 and 1.5 times higher, respectively). The values for TyG Index and adEV size were different between the control animals and the high-fat diet group. Multiple linear regression analyses showed that adEV size can be significantly associated with the TyG Index value, when controlling for epididymal AT weight. Our results show that lipid and glucose metabolism, as well as the size and zeta potential of adEV are already altered in early-stage obesity and that adEV size can be significantly associated with liver and systemic IR, estimated by TyG Index.

Concentration and Composition of Circulating Adipocyte-Derived Extracellular Vesicles in Patients with Colonic Polyps and Colorectal Cancer

Concentration and Composition of Circulating Adipocyte-Derived Extracellular Vesicles in Patients with Colonic Polyps and Colorectal Cancer

Adipose Tissue Dysfunction and the Role of Adipocyte-Derived Extracellular Vesicles in Obesity and Metabolic Syndrome.

Obesity is a major public health issue that is associated with metabolic diseases including diabetes mellitus type 2 and metabolic syndrome. This pathology leads to detrimental cardiovascular health and secondary effects, such as lipotoxicity, inflammation, and oxidative stress. Recently, extracellular vesicles (EVs) have been highlighted as novel players participating in human physiology and pathophysiology. In obesity, adipose tissue is related to the active shedding of adipocyte-derived extracellular vesicles (AdEVs). The current review explores and highlights the role of AdEVs and their cargo in obesity and metabolic syndrome. AdEVs are proposed to play an important role in obesity and its comorbidities. AdEVs are biological nanoparticles mainly shed by visceral and subcutaneous adipose tissue, acting in physiological and pathophysiological conditions, and also carrying different cargo biomolecules, such as RNA, microRNA (miRNA), proteins, and lipids, among others. RNA and miRNA have local and systemic effects affecting gene expression in target cell types via paracrine and endocrine actions. State of the art analyses identified some miRNAs, such as miR-222, miR-23b, miR-4429, miR-148b, and miR-4269, that could potentially affect cell pathways involved in obesity-related comorbidities, such as chronic inflammation and fibrosis. Similarly, AdEVs-proteins (RBP4, perilipin-A, FABP, mimecan, TGFBI) and AdEVs-lipids (sphingolipids) have been linked to the obesity pathophysiology. The current knowledge about AdEVs along with further research would support and reveal novel pathways, potential biomarkers, and therapeutic options in obesity.

Proteomic profiling points to the significance of adipocyte-derived extracellular vesicles in diet-induced obesity

Extracellular vesicles (EVs) are lipid-bilayer membrane-enclosed vesicles well known to mediate cell-cell communication to maintain normal physiological functions. The diverse cargo of EVs encompassing proteins, lipids and miRNAs represent potential biomarkers and therapeutic targets. However, the role of adipocyte-derived EVs (AdEVs) in obesity is still unknown. To address this, we performed proteomic profiling of AdEVs isolated from the C57BL/6 male mice that were fed either a normal chow diet (NCD) or a high-fat high-sucrose diet (HFHSD) for 12 weeks starting at 4 weeks of age. AdEVs were obtained, through ultracentrifugation, from the conditioned media of cultured adipocytes derived from gonadal adipose tissue. Nanoparticle tracking analysis (NTA) of AdEVs showed that adipocytes from mice fed HFHSD tended to release more AdEVs despite the comparable size of AdEVs relative to those of mice fed NCD. Subsequently, proteins were isolated, digested and labeled with TMTpro16-plex for proteomic analysis. Raw data were processed in Scaffold, and a general bioinformatic and functional analysis conducted in Ingenuity Pathway Analysis Qiagen (IPA) ( https://digitalinsights.qiagen.com/explore/ga-ipa?utm_source=QDI_GA_SA_IPA_1122_PF&cmpid=QDI_GA_IPA ) and Srplot identified over 1100 proteins in AdEVs (protein threshold: 99%, minim peptide:2, peptide threshold: 95%, 0.00% FDR). Of these, 58 proteins were identified as upregulated while 41 proteins were downregulated in HFHSD-fed mice (Fold Change > 2, adjusted p < 0.05). With IPA analysis, the top 3 influenced pathways including mitochondrial dysfunction (27%), Sirtuin signaling pathway (22%), and Granzyme A signaling (38%) are predicted to be activated while the oxidative phosphorylation (47%), estrogen receptor signaling (15%) and neutrophil extracellular trap signaling pathway (14%) are predicted to be inhibited. The Gene Oncology (GO) functional enrichment analysis in Srplot revealed the involvement of identified differentially expressed proteins in various biological processes such as lipid metabolism, catabolic process processes, and cellular respiration. Experiments are underway to validate specific proteins involved in these biological processes. Furthermore, analysis of cellular components highlighted three notable terms including myelin sheath, collagen-containing extracellular matrix and organelle inner membrane. In conclusion, the present study elucidates the significance of AdEVs in the context of diet-induced obesity and underscores the potential role of mitochondrial dysfunction in the initiation and progression of obesity and its associated diseases. NIH Veterans Affairs. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Abstract 6969: Determining the role of obesity in breast cancer progression

Abstract Breast cancer, especially triple negative breast cancer, impacts a large proportion of the female population. Approximately ten to fifteen percent of all breast cancer diagnoses will be triple negative. Triple negative breast cancer lacks receptors that are used as therapeutic targets for other forms of breast cancer and has the poorest prognosis. Notably, the age of onset has also decreased, which correlates with the rise in prevalence of obesity. In addition, past studies revealed that maintaining a high BMI from childhood correlates with higher cancer mortality in adulthood. However, the mechanisms by which obesity contributes to cancer progression are not clear. Adipose tissue from different locations (visceral vs. subcutaneous, abdominal vs. femoral) and from patients with obesity from childhood rather than as adults could have different molecular characteristics. Further, depending on the genetic background, different profiles may be more susceptible to environmental cues that could drive their progression. To address this, we are using conditioned media collected from tissues that reflect these differences and determining how they affect TNBC cell lines with distinct genetic profiles. Preliminary data revealed that adipose tissue from both the abdominal and femoral regions of high BMI individuals caused an increase in the proliferation rate of TNBC cell lines. To determine if the adipocytes vs. other cell types in the adipose tissue drive this growth, we are co-culturing mature adipocytes from these tissues with the TNBC cell lines. Recent studies by other groups showed that adipocyte-derived extracellular vesicles could drive the expression of EMT genes in cancer cells. We will purify EVs from the adipocytes and characterize differences in their molecular signatures for different patients to determine which factors cause the change in TNBC progression and correlate this with different fat depots and/or age of onset. We will also measure the effect of adipose tissue and/or adipocytes on other cancer hallmarks including metastasis (migration and invasion) and changes in metabolism. These studies should reveal how adipocytes confer changes in TNBC progression, and how to consider obesity in different treatment regimes. Citation Format: Alexandra Perlman, Alisa Piekny, Elena Kuzmin, Sylvia Santosa. Determining the role of obesity in breast cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6969.

Abstract 293: Distinctive roles of mammary adipomes in breast cancer progression: Insights from functional analysis and differential gene expression

Abstract Breast Cancer (BC) is a heterogeneous disease that impacts treatment response. This is due in part to the tumor microenvironment (TME), which contributes significantly to BC pathogenesis, including metastasis. Women with higher breast density and reduced breast fat face an increased BC risk across multiple tumor subtypes. This is exemplified by the correlation between increased tumor progression, the appearance of fibrosis and the loss of mature adipocytes. While the role of adipokines in this process has been studied extensively, the contribution of adipocyte-derived extracellular vesicles (EV) or "adipomes" in tumorigenesis and metastasis remains poorly understood. To address this question, we developed a novel technique for isolating intact adipomes from normal mammary fat (MF) obtained from wild-type C57BL/6 mice as well as from tumor-associated MF (TAMF) obtained from mice inoculated orthotopically with EO771 mammary tumor cells. Adipome isolation involved high-speed centrifugation to separate macro- and micro-vesicles, purification using the ExoQuick EV isolation system, and immunomagnetic capture of adipomes. Characterization of adipomes by transmission electron microscopy revealed two adipome populations, large L-adipomes of ~350 nm, and small S-adipomes of ~40 nm. Notably, the quantity of L-adipomes in tumor-associated mammary fat (TAMF) was 10-fold greater than the amount of L-adipomes in the MF of non-tumor-bearing mice. To identify possible functional roles of L-adipomes in the pathogenesis of BC, lipidomic profiling was undertaken. L-Adipomes from TAMF showed significantly altered lipid species in comparison to MF-derived L-adipomes. Adipomes were further characterized by treating EO771 cells for 72 hr with TAMF- or MF-derived adipomes at a cell to adipome ratio of 1:10, followed by RNAseq analysis. Differentially upregulated genes in TAMF-derived L-adipomes included Esr1, Erbb2, Tgfb1, Bcl2, MMP2, and Notch associated with fibrosis, EMT, angiogenesis and invasion and downregulation of genes linked to tumor suppression, apoptosis, and mitochondrial metabolism. Overall, our study illustrates the importance of tumor-associated adipomes in regulating gene expression in tumor cells, which emphasizes the specificity of adipome content relating to the cell-of-origin and the host's pathologic and metabolic state and in modulating signaling pathways involved in BC progression. Citation Format: Hariprasad Thangavel, Kezia Lizardo, Robert I. Glazer, Jyothi F. Nagajyothi. Distinctive roles of mammary adipomes in breast cancer progression: Insights from functional analysis and differential gene expression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 293.

Neonatal adiposity is associated with microRNAs in adipocyte-derived extracellular vesicles in maternal and cord blood, a discovery analysis.

Maternal body size, nutrition, and hyperglycemia contribute to neonatal body size and composition. There is little information on maternal-fetal transmission of messages which influence fetal growth. We analyzed adipocyte-derived small extracellular vesicular (ADsEV) microRNAs in maternal and cord blood to explore their adipogenic potential. There were 279 mother-neonate pairs with all phenotypic data (normal glucose tolerant NGT = 148, gestational diabetes mellitus GDM = 131). Neonates with adiposity were those in the highest tertile (T3) of sex-specific sum of skinfolds and those without adiposity (lean) in the lowest tertile T1 of NGT pregnancies. We studied ADsEV miRNAs in 76 and 51 neonates with and without adiposity respectively and their mothers based on power calculations (68 NGT and 59 GDM pregnancies). ADsEV miRNAs from maternal and cord blood plasma samples were profiled on Agilent 8*60 K microarray. Differential expression (DE) of ADsEV miRNAs in adipose vs. lean groups was studied before and after adjustment for maternal GDM, adiposity, and vitamin B12-folate status. Multiple miRNAs were common in maternal and cord blood and positively correlated. We identified 24 maternal and 5 cord blood miRNAs differentially expressed (discovery p ≤ 0.1) in the adipose group in unadjusted, and 19 and 26, respectively, in the adjusted analyses. Even though DE miRNAs were different in maternal and cord blood, they targeted similar adipogenic pathways (e.g., the forkhead box O (FOXO) family of transcription factors, mitogen‑activated protein kinase (MAPK) pathway, transforming growth factor beta (TGF-β) pathway). Maternal GDM and adiposity were associated with many DE ADsEV miRNAs. Our results suggest that the ADsEV miRNAs in mothers are potential regulators of fetal adiposity. The expression and functionality of miRNAs appear to be influenced by maternal adiposity, hyperglycemia, and micronutrient status during pregnancy.

Understanding the Consequences of Fatty Bone and Fatty Muscle: How the Osteosarcopenic Adiposity Phenotype Uncovers the Deterioration of Body Composition.

Adiposity is central to aging and several chronic diseases. Adiposity encompasses not just the excess adipose tissue but also body fat redistribution, fat infiltration, hypertrophy of adipocytes, and the shifting of mesenchymal stem cell commitment to adipogenesis. Bone marrow adipose tissue expansion, inflammatory adipokines, and adipocyte-derived extracellular vesicles are central to the development of osteopenic adiposity. Adipose tissue infiltration and local adipogenesis within the muscle are critical in developing sarcopenic adiposity and subsequent poorer functional outcomes. Ultimately, osteosarcopenic adiposity syndrome is the result of all the processes noted above: fat infiltration and adipocyte expansion and redistribution within the bone, muscle, and adipose tissues, resulting in bone loss, muscle mass/strength loss, deteriorated adipose tissue, and subsequent functional decline. Increased fat tissue, typically referred to as obesity and expressed by body mass index (the latter often used inadequately), is now occurring in younger age groups, suggesting people will live longer with the negative effects of adiposity. This review discusses the role of adiposity in the deterioration of bone and muscle, as well as adipose tissue itself. It reveals how considering and including adiposity in the definition and diagnosis of osteopenic adiposity, sarcopenic adiposity, and osteosarcopenic adiposity will help in better understanding the pathophysiology of each and accelerate possible therapies and prevention approaches for both relatively healthy individuals or those with chronic disease.

Vitamin D Modulates Lipid Composition of Adipocyte-Derived Extracellular Vesicles Under Inflammatory Conditions.

Adipocyte-derived extracellular vesicles (AdEVs) convey lipids that can play a role in the energy homeostasis. Vitamin D (VD) has been shown to limit the metabolic inflammation as it decreases inflammatory markers expression in adipose tissue (AT). However, VD effect on adipocytes-derived EVs has never been investigated. Thus, the aim of this study is to evaluate the AdEVs lipid composition by LC-MS/MS approach in 3T3-L1 cells treated with VD or/and pro-inflammatory factor (tumor necrosis factor α[TNFα]). Among all lipid species, four are highlighted (glycerolipids, phospholipids, lysophospholipids, and sphingolipids) with a differential content between small (sEVs) and large EVs (lEVs). This study also observes that VD alone modulates EV lipid species involved in membrane fluidity and in the budding of membrane. EVs treated with VD under inflammatory conditions have different lipid profiles than the control group, which is more pronounced in lEVs. Indeed, 25 lipid species are significantly modulated in lEVs, compared with only seven lipid species in sEVs. This study concludes that VD, alone or under inflammatory conditions, is associated with specific lipidomic signature of sEVs and lEVs. These observations reinforce current knowledge on the anti-inflammatory effect of VD.

Adipocyte-Derived Extracellular Vesicles: Small Vesicles with Big Impact.

While increasing numbers of studies have established that adipose tissue plays a vital role in balancing energy intake and energy expenditure as both an energy and an endocrine organ, the detailed functions of adipose tissue remain unclear. Adipose tissues are complex, with multiple resident cell populations that communicate to diverse cells and organs via local and systemic metabolic, thermal, and inflammatory signaling. In normal physiology, adipose tissue-derived extracellular vesicles mediate the regulation of energy storage/consumption in adipose tissue, liver, and muscle. In a pathological sense, fat-derived extracellular vesicles can promote the progression of obesity, endocrine diseases, cancer, and reproductive system disorders. In this review, we demonstrate that adipocyte-derived extracellular vesicles function not only in physiological balance but also in the pathological process. We aim to illustrate the impact of adipocyte-derived extracellular vesicles and their value in understanding both homeostasis and disorders.

Delivery of SIRT1 by cancer-associated adipocyte-derived extracellular vesicles regulates immune response and tumorigenesis of ovarian cancer cells.

This study intends to investigate the possible molecular mechanism of immune response and tumorigenesis in ovarian cancer cells, mediated by sirtuin 1 (SIRT1)-containing extracellular vesicles (EVs) derived from cancer-associated adipocytes (CAAs) (CAA-EVs). Differentially expressed genes in EVs from CAAs were screened by RNA transcriptome sequencing, and the downstream pathway was predicted in silico. The binding between SIRT1 and CD24 was investigated by luciferase activity and ChIP-PCR assays. EVs were extracted from human ovarian cancer tissue-isolated CAAs, and the internalization of CCA-EVs by ovarian cancer cells was characterized. The ovarian cancer cell line was injected into mice to establish an animal model. Flow cytometry was performed to analyze the proportions of M1 and M2 macrophages, CD8+ T, T-reg, and CD4+ T cells. TUNEL staining was used to detect cell apoptosis in the mouse tumor tissues. ELISA detection was performed on immune-related factors in the serum of mice. CAA-EVs could deliver SIRT1 to ovarian cancer cells, thereby affecting the immune response of ovarian cancer cells in vitro and promoting tumorigenesis in vivo. SIRT1 could transcriptionally activate the expression of CD24, and CD24 could up-regulate Siglec-10 expression. CAA-EVs-SIRT1 activated the CD24/Siglec-10 axis and promoted CD8+ T cell apoptosis, thereby promoting tumorigenesis in mice. CAA-EVs-mediated transfer of SIRT1 regulates the CD24/Siglec-10 axis to curb immune response and promote tumorigenesis of ovarian cancer cells.

Differential expression of adipocyte and myotube extracellular vesicle miRNA cargo in chronic binge alcohol-administered SIV-infected male macaques.

Our studies in chronic binge alcohol (CBA) -treated simian immunodeficiency virus (SIV)-infected macaques and in people living with HIV (PLWH) show significant alterations in metabolic homeostasis. CBA promotes a profibrotic phenotype in adipose tissue and skeletal muscle (SKM) and decreases adipose-derived stem cell and myoblast differentiation, making adipose and SKM potential drivers in metabolic dysregulation. Furthermore, we have shown that the differential expression of microRNAs (miRs) in SKM contributes to impaired myoblast differentiation potential. Beyond modulation of intracellular responses, miRs can be transported in extracellular vesicles (EVs) to mediate numerous cellular responses through intercellular and interorgan communication. This study tested the hypothesis that CBA alters concentration and miR cargo of EVs derived from adipocytes and myotubes isolated from SIV-infected male macaques. Fourteen male rhesus macaques received either CBA (2.5g/kg/day) or sucrose (VEH) for 14.5 months. Three months following the initiation of CBA/VEH, all animals were infected with SIVmac251 and 2.5 months later were initiated on antiretroviral therapy. SKM and adipose tissue samples were collected at the study endpoint (blood alcohol concentration=0mM). EVs were isolated by ultracentrifugation of myotube and adipocyte cell culture supernatant. Nanoparticle tracking revealed no differences in concentration or size of particles between VEH and CBA groups. Adipocyte-derived EVs from CBA animals showed decreased miR-let-7a expression (p=0.03). Myotube-derived EVs from CBA animals had decreased miR-16 (p=0.04) and increased miR-133a and miR-133b (both p=0.04) expression. These results indicate that CBA administration differentially regulates EV miR content but does not alter the number of EVs from adipocytes or myotubes. Future studies are warranted to determine the functional relevance of CBA-altered EV miR cargo and their role in intercellular and interorgan communication and metabolic dysregulation.

Role of adipocyte-derived extracellular vesicles during the progression of liver inflammation to hepatocellular carcinoma.

Extracellular vesicles are membrane-bound cargos that vary in size and are stably transported through various bodily fluids. Extracellular vesicles communicate information between the cells and organs. Extracellular vesicles from the diseased cells alter cellular responses of the recipient cells contributing to disease progression. In obesity, adipocytes become hypertrophic and the extracellular vesicles from these dysfunctional adipocytes showed altered cargo contents instigating pathophysiological response leading to chronic liver diseases. In this review, the role of adipocyte-derived extracellular vesicles on the progression of liver inflammation, fibrosis, cirrhosis,and hepatocellular carcinoma are extensively discussed. Newer approaches are crucial to take advantage of extracellular vesicles and their content as biomarkers to diagnose initial liver inflammation before reaching to an irreversible liver failure stage.

Exploring Adipose Tissue Functions.

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Adipocyte-derived extracellular vesicles increase insulin secretion through transport of insulinotropic protein cargo

Adipocyte-derived extracellular vesicles (AdEVs) are membranous nanoparticles that convey communication from adipose tissue to other organs. Here, to delineate their role as messengers with glucoregulatory nature, we paired fluorescence AdEV-tracing and SILAC-labeling with (phospho)proteomics, and revealed that AdEVs transfer functional insulinotropic protein cargo into pancreatic β-cells. Upon transfer, AdEV proteins were subjects for phosphorylation, augmented insulinotropic GPCR/cAMP/PKA signaling by increasing total protein abundances and phosphosite dynamics, and ultimately enhanced 1st-phase glucose-stimulated insulin secretion (GSIS) in murine islets. Notably, insulinotropic effects were restricted to AdEVs isolated from obese and insulin resistant, but not lean mice, which was consistent with differential protein loads and AdEV luminal morphologies. Likewise, in vivo pre-treatment with AdEVs from obese but not lean mice amplified insulin secretion and glucose tolerance in mice. This data suggests that secreted AdEVs can inform pancreatic β-cells about insulin resistance in adipose tissue in order to amplify GSIS in times of increased insulin demand.

Adipocyte-Derived Extracellular Vesicles: Caveolin Matters.

Adipocyte-Derived Extracellular Vesicles: Caveolin Matters.