Exosomes as the source of biomarkers of metabolic diseases

Chromatographic purification of small extracellular vesicles using an affinity column for phospholipid membranes

OBJECTIVES

This study aimed to investigate whether chromatography using an ExoPUA column, an affinity column for phospholipid membranes, could potentially serve as an efficient, rapid, scalable, and reproducible method for purifying small extracellular vesicles (sEVs).

RESULTS

We used the ExoPUA column connected to a fast-performance liquid chromatography system. One-step chromatographic purification of sEVs from culture supernatant using the ExoPUA protocol resulted in an 82 ± 16-fold increase in purity with a yield of 38 ± 5% of sEVs. The purified sEVs contained CD9, CD63, TSG101, and miRNA (miR-21), but not the endoplasmic reticulum protein Calnexin. Transmission electron microscopy indicated that the purified sEVs were intact. The purification performance of the ExoPUA protocol showed superior results in terms of yield compared to that of the differential ultracentrifugation method, the most commonly used method for purifying sEVs in laboratories, and purity compared to that of the DEAE chromatography protocol.

CONCLUSION

The sEVs were effectively purified in the bind-elute mode and the ExoPUA column can be refreshed and sterilized with sodium hydroxide (NaOH), having high potential for multiple sEV purification in a scalable and industrial manner.

Exosomal microRNAs and long noncoding RNAs: as novel biomarkers for endometriosis

Endometriosis is a gynecological inflammatory disorder characterized by the development of endometrial-like cells outside the uterine cavity. This disease is associated with a wide range of clinical presentations, such as debilitating pelvic pain and infertility issues. Endometriosis diagnosis is not easily discovered by ultrasound or clinical examination. Indeed, difficulties in noninvasive endometriosis diagnosis delay the confirmation and management of the disorder, increase symptoms, and place a significant medical and financial burden on patients. So, identifying specific and sensitive biomarkers for this disease should therefore be a top goal. Exosomes are extracellular vesicles secreted by most cell types. They transport between cells' bioactive molecules such as noncoding RNAs and proteins. MicroRNAs and long noncoding RNAs which are key molecules transferred by exosomes have recently been identified to have a significant role in endometriosis by modulating different proteins and their related genes. As a result, the current review focuses on exosomal micro-and-long noncoding RNAs that are involved in endometriosis disease. Furthermore, major molecular mechanisms linking corresponding RNA molecules to endometriosis development will be briefly discussed to better clarify the potential functions of exosomal noncoding RNAs in the therapy and diagnosis of endometriosis.

Placental Exosomes as Biomarkers for Maternal Diseases: Current Advances in Isolation, Characterization, and Detection

Serving as the interface between fetal and maternal circulation, the placenta plays a critical role in fetal growth and development. Placental exosomes are small membrane-bound extracellular vesicles released by the placenta during pregnancy. They contain a variety of biomolecules, including lipids, proteins, and nucleic acids, which can potentially be biomarkers of maternal diseases. An increasing number of studies have demonstrated the utility of placental exosomes for the diagnosis and monitoring of pathological conditions such as pre-eclampsia and gestational diabetes. This suggests that placental exosomes may serve as new biomarkers in liquid biopsy analysis. This review provides an overview of the current understanding of the biological function of placental exosomes and their potential as biomarkers of maternal diseases. Additionally, this review highlights current barriers and the way forward for standardization and validation of known techniques for exosome isolation, characterization, and detection. Finally, microfluidic devices for exosome research are discussed.

Mesenchymal Stem Cell-Derived Extracellular Vesicles: The Novel Therapeutic Option for Regenerative Dentistry

Dental mesenchymal stem cells (MSCs) are characterized by unlimited self-renewal ability and high multidirectional differentiation potential. Since dental MSCs can be easily isolated and exhibit a high capability to differentiate into odontogenic cells, they are considered as attractive therapeutic agents in regenerative dentistry. Recently, MSC-derived extracellular vesicles (MSC-EVs) have attracted widespread attention as carriers for cell-free therapy due to their potential functions. Many studies have shown that MSC-EVs can mediate microenvironment at tissue damage site, and coordinate the regeneration process. Additionally, MSC-EVs can mediate intercellular communication, thus affecting the phenotypes and functions of recipient cells. In this review, we mainly summarized the types of MSCs that could be potentially applied in regenerative dentistry, the possible molecular cargos of MSC-EVs, and the major effects of MSC-EVs on the therapeutic induction of osteogenic differentiation.

Extracellular vesicles biogenesis, isolation, manipulation and genetic engineering for potential in vitro and in vivo therapeutics: An overview

The main goals of medicine consist of early detection and effective treatment of different diseases. In this regard, the rise of exosomes as carriers of natural biomarkers has recently attracted a lot of attention and managed to shed more light on the future of early disease diagnosis methods. Here, exosome biogenesis, its role as a biomarker in metabolic disorders, and recent advances in state-of-art technologies for exosome detection and isolation will be reviewed along with future research directions and challenges regarding the manipulation and genetic engineering of exosomes for potential in vitro and in vivo disease diagnosis approaches.

Protein Farnesylation on Nasopharyngeal Carcinoma, Molecular Background and Its Potential as a Therapeutic Target

Simple Summary

Nasopharyngeal carcinoma is distinguished from other head and neck carcinomas by the association of its carcinogenesis with the Epstein–Barr virus. It is highly metastatic, and a novel therapeutic modality for metastatic nasopharyngeal carcinoma is keenly awaited. Protein farnesylation is a C-terminal lipid modification of proteins and was initially investigated as a key process in activating the RAS oncoprotein through its association with the cellular membrane structure. Since then, more and more evidence has accumulated to indicate that proteins other than RAS are also farnesylated and have significant roles in carcinogenesis. This review delineates molecular pathogenesis through protein farnesylation in the context of nasopharyngeal carcinoma and discusses the potential of farnesylation as a therapeutic target.

Abstract

Nasopharyngeal carcinoma (NPC) is one of the Epstein–Barr virus (EBV)-associated malignancies. NPC is highly metastatic compared to other head and neck carcinomas, and evidence has shown that the metastatic features of NPC are involved in EBV infection. The prognosis of advanced cases, especially those with distant metastasis, is still poor despite advancements in molecular research and its application to clinical settings. Thus, further advancement in basic and clinical research that may lead to novel therapeutic modalities is needed. Farnesylation is a lipid modification in the C-terminus of proteins. It enables proteins to attach to the lipid bilayer structure of cellular membranes. Farnesylation was initially identified as a key process of membrane association and activation of the RAS oncoprotein. Farnesylation is thus expected to be an ideal therapeutic target in anti-RAS therapy. Additionally, more and more molecular evidence has been reported, showing that proteins other than RAS are also farnesylated and have significant roles in cancer progression. However, although several clinical trials have been conducted in cancers with high rates of ras gene mutation, such as pancreatic carcinomas, the results were less favorable than anticipated. In contrast, favorable outcomes were reported in the results of a phase II trial on head and neck carcinoma. In this review, we provide an overview of the molecular pathogenesis of NPC in terms of the process of farnesylation and discuss the potential of anti-farnesylation therapy in the treatment of NPC.

Exosomal miR-29b found in aqueous humour mediates calcium signaling in diabetic patients with cataract

AIM

To investigate the role of exosomal miR-29b and Ca²⁺ in regulating the function of human lens epithelial cells (HLECs).

METHODS

Exosomes were isolated from human aqueous humour (AH) by ultracentrifugation, and visualized by nanoparticle tracking and transmission electron microscopy. Exosomal miRNA sequencing was performed to identify differentially expressed miRNAs between diabetes with cataracts (DMC) group and age-related cataracts (ARC) group. TargetScan was used to predict potential target of certain miRNA. The expression of CACNA1C mRNA was determined by quantitative real-time polymerase chain reaction and CACNA1C protein was determined by Western blotting. Concentration of Ca²⁺ in human AH and the culture supernatant of cells were detected by the calcium assay kit. Cell counting kit-8 was used to determine cell viability.

RESULTS

Exosomes were isolated from human AH, which had a typical cup-shaped phenotype and a particle size distribution in accordance with micro extracellular vesicles. Exosomal miRNA sequencing revealed that miR-29b was significantly downregulated in DMC group compared with ARC. Ca²⁺ concentration of human AH in DMC was higher than that in ARC. The culture supernatant of cells transfected with miR-29b inhibitors had a higher concentration of Ca²⁺ than that transfected with miR-29b mimics. miR-29b reduced the viability of HLECs by upregulating CACNA1C expression.

CONCLUSION

Exosomes isolated from human AH contains abundant miRNAs. A significantly expressed miRNA, miR-29b, can affect the concentration of Ca²⁺ and regulate HLEC processes by upregulating CACNA1C.

Identification of amyloid beta in small extracellular vesicles via Raman spectroscopy

One of the hallmarks of Alzheimer's disease (AD) pathogenesis is believed to be the production and deposition of amyloid-beta (Aβ) peptide into extracellular plaques. Existing research indicates that extracellular vesicles (EVs) can carry Aβ associated with AD. However, characterization of the EVs-associated Aβ and its conformational variants has yet to be realized. Raman spectroscopy is a label-free and non-destructive method that is able to assess the biochemical composition of EVs. This study reports for the first time the Raman spectroscopic fingerprint of the Aβ present in the molecular cargo of small extracellular vesicles (sEVs). Raman spectra were measured from sEVs isolated from Alzheimer's disease cell culture model, where secretion of Aβ is regulated by tetracycline promoter, and from midbrain organoids. The averaged spectra of each sEV group showed considerable variation as a reflection of the biochemical content of sEVs. Spectral analysis identified more intense Raman peaks at 1650 cm^-1 and 2930 cm^-1 attributable to the Aβ peptide incorporated in sEVs produced by the Alzheimer's cell culture model. Subsequent analysis of the spectra by principal component analysis differentiated the sEVs of the Alzheimer's disease cell culture model from the control groups of sEVs. Moreover, the results indicate that Aβ associated with secreted sEVs has a α-helical secondary structure and the size of a monomer or small oligomer. Furthermore, by analyzing the lipid content of sEVs we identified altered fatty acid chain lengths in sEVs that carry Aβ that may affect the fluidity of the EV membrane. Overall, our findings provide evidence supporting the use of Raman spectroscopy for the identification and characterization of sEVs associated with potential biomarkers of neurological disorders such as toxic proteins.

LPS-enriched small extracellular vesicles from metabolic syndrome patients trigger endothelial dysfunction by activation of TLR4

BACKGROUND

Metabolic syndrome (MetS) is characterized by a cluster of interconnected risk factors -hyperglycemia, dyslipidemia, hypertension and obesity- leading to an increased risk of cardiovascular events. Small extracellular vesicles (sEVs) can be considered as new biomarkers of different pathologies, and they are involved in intercellular communication. Here, we hypothesize that sEVs are implicated in MetS-associated endothelial dysfunction.

METHODS

Circulating sEVs of non-MetS (nMetS) subjects and MetS patients were isolated from plasma and characterized. Thereafter, sEV effects on endothelial function were analyzed by measuring nitric oxide (NO) and reactive oxygen species (ROS) production, and mitochondrial dynamic proteins on human endothelial aortic cells (HAoECs).

RESULTS

Circulating levels of sEVs positively correlated with anthropometric and biochemical parameters including visceral obesity, glycaemia, insulinemia, and dyslipidemia. Treatment of HAoECs with sEVs from MetS patients decreased NO production through the inhibition of the endothelial NO-synthase activity. Injection of MetS-sEVs into mice impaired endothelium-dependent relaxation induced by acetylcholine. Furthermore, MetS-sEVs increased DHE and MitoSox-associated fluorescence in HAoECs, reflecting enhanced cytosolic and mitochondrial ROS production which was not associated with mitochondrial biogenesis or dynamic changes. MetS patients displayed elevated circulating levels of LPS in plasma, and, at least in part, it was associated to circulating sEVs. Pharmacological inhibition and down-regulation of TLR4, as well as sEV-carried LPS neutralization, results in a substantial decrease of ROS production induced by MetS-sEVs.

CONCLUSION

These results evidence sEVs from MetS patients as potential new biomarkers for this syndrome, and TLR4 pathway activation by sEVs provides a link between the endothelial dysfunction and metabolic disturbances described in MetS.

Proteomic Profile of Urinary Extracellular Vesicles Identifies AGP1 as a Potential Biomarker of Primary Aldosteronism

CONTEXT

Primary aldosteronism (PA) represents 6% to 10% of all essential hypertension patients and is diagnosed using the aldosterone-to-renin ratio (ARR) and confirmatory studies. The complexity of PA diagnosis encourages the identification of novel PA biomarkers. Urinary extracellular vesicles (uEVs) are a potential source of biomarkers, considering that their cargo reflects the content of the parent cell.

OBJECTIVE

We aimed to evaluate the proteome of uEVs from PA patients and identify potential biomarker candidates for PA.

METHODS

Second morning spot urine was collected from healthy controls (n = 8) and PA patients (n = 7). The uEVs were isolated by ultracentrifugation and characterized. Proteomic analysis on uEVs was performed using LC-MS Orbitrap.

RESULTS

Isolated uEVs carried extracellular vesicle markers, showed a round shape and sizes between 50 and 150 nm. The concentration of uEVs showed a direct correlation with urinary creatinine (r = 0.6357; P = 0.0128). The uEV size mean (167 ± 6 vs 183 ± 4nm) and mode (137 ± 7 vs 171 ± 11nm) was significantly smaller in PA patients than in control subjects, but similar in concentration. Proteomic analysis of uEVs from PA patients identified an upregulation of alpha-1-acid glycoprotein 1 (AGP1) in PA uEVs, which was confirmed using immunoblot. A receiver operating characteristic curve analysis showed an area under the curve of 0.92 (0.82 to 1; P = 0.0055).

CONCLUSION

Proteomic and further immunoblot analyses of uEVs highlights AGP1 as potential biomarker for PA.

Nanoelectrical characterization of individual exosomes secreted by Aβ42-ingested cells using electrostatic force microscopy

Quantifying the physical properties of individual exosomes containing amyloid-β₄₂ (Aβ₄₂) is crucial for a better understanding of an underpinning mechanism of Alzheimer's disease expression which is associated with the Aβ₄₂ transfer. Because of the lack of proper tools, however, there have been very few studies on how the amount of Aβ₄₂ affects the physical properties of exosomes. To answer the question, we investigated the physical properties of exosomes secreted by neuroblastoma by probing individual exosomes using electrostatic force microscopy. Interestingly, we observed that when the higher concentration of Aβ₄₂ oligomers was fed to cells, the higher surface charge of the exosomes appeared. This result indicates that the exosomes contain more Aβ₄₂ with the increase in Aβ₄₂ concentration in cell media, implying that they serve as transport vesicles for Aβ₄₂. Our approach could help to better understand how the neuronal exosomes are related to the propagation of neurodegenerative diseases and to seek how to make an early diagnosis of those diseases.

Roles of Exosomes and Exosomal MicroRNAs in Postoperative Sleep Disturbance

Postoperative sleep disturbance (PSD) often occurs in elderly patients after major surgery and exerts harmful effects on postoperative recovery. PSD may increase the incidence of postoperative fatigue, severe anxiety and depression, pain sensitivity, and cognitive dysfunction, which can cause or aggravate neurodegenerative diseases via amyloid aggregation and tau accumulation. Exosomes are important carriers that mediate the transfer of active substances and genetic information among cells. Recent evidence has shown that exosomes are involved in the pathogenesis of end-organ morbidity caused by sleep disorders via increasing amyloid plaque formation, transmitting tau protein, regulating neuroinflammation, and increasing blood-brain barrier permeability. Additionally, exosomes may be useful for delivering therapeutic genetic materials, such as microRNAs (miRNAs) and proteins, to exert neuroprotective effects and reduce cognitive impairment. However, the molecular mechanisms underlying this process remain to be fully elucidated. This review focuses on exosome-related pathways and the modulatory role of exosomal miRNAs on the pathogenesis of sleep disturbance and neurodegeneration. Moreover, we discuss the advantages of reducing neurotoxic proteins via exosomal intervention and miRNA regulation. Future research in exosome administration may offer new insights into PSD-related pathomechanisms and therapeutics.

Application of peptides with an affinity for phospholipid membranes during the automated purification of extracellular vesicles

Extracellular vesicles (EVs), such as exosomes, have garnered increasing interest because of their potential clinical applications that range from diagnostics to therapeutics. The development of an automated and reproducible EV purification platform would therefore aid the introduction of EV biomarkers and therapies into the clinic. Here, we demonstrate that K8- as well as K-16 peptides (containing 8 and 16 lysine residues with dissociation constants of 102 nM and 11.6 nM for phosphatidylserine, respectively) immobilized on magnetic beads can capture small EVs (< 0.2 µm) from culture supernatants of MCF7 human breast cancer cells. Importantly, the bound EVs could be dissociated from the beads under mild conditions (e.g. 0.5 M NaCl), and the isolated EVs had the typical shapes of EVs under SEM and TEM with a mean particle size of 99 nm. Using the peptide-immobilized beads, we adapted a pre-existing bench top instrument for magnetic separation to perform automated EV purification with higher purity and yield than that obtained using the standard ultracentrifugation method.

The Potential of Liquid Biopsy of the Brain Using Blood Extracellular Vesicles: The First Step Toward Effective Neuroprotection Against Neurodegenerative Diseases

Early diagnosis and biomarker-based ante-mortem tests are essential in efforts against the development of neurodegenerative diseases and can be considered primary neuroprotective measures. Blood is the ideal biofluid for a routine ante-mortem screening test. However, biomarker discovery in the blood is particularly difficult because of interference from factors both intrinsic and extrinsic to blood with the detection of hallmark neurodegenerative biomarkers, such as the pathological prion protein, amyloid-β, and others. Blood extracellular vesicles (EVs), such as exosomes, are cell-derived vesicles released into the blood from all parts of the body (including the brain and spinal cord). They are an enriched source of neural-derived EVs containing neurodegenerative biomarkers that mirror (in the blood) the condition present in the brain. The feasibility of using, and the reliability of, neural-derived blood EVs (NDBEVs) as a method of diagnosing Alzheimer disease and other neurodegenerative diseases has been assessed in strong proof-of-concept studies. Results from these studies strongly suggest that NDBEVs might represent the right strategy for specific, reliable, and early diagnosis of neurodegenerative diseases. Based on these results, NDBEVs might enable the creation of an ante-mortem blood test (liquid biopsy of the brain) for neurodegenerative diseases. This would enormously accelerate the therapy of neurodegenerative diseases. This review highlights the powerful potential of liquid biopsy of the brain using NDBEVs for early diagnosis and treatment of neurodegenerative diseases, and the challenges and limitations related to the identification of clinically applicable EV (exosomal) biomarkers using blood are discussed.

Exosomal miRNA Analysis of Aqueous Humour of Diabetes and Cataract Patients

BACKGROUND

The mechanism of diabetes and cataracts is complicated. Considering our increasing acknowledge of exosomes, exosomal miRNAs isolated from aqueous humour (AH) may play an important role in the mechanism of diabetes and cataracts. Our study aimed to isolate exosomes from human aqueous humour and study the functions of exosomal miRNAs on human lens epithelial cells (HLECs).

RESULTS

MiRNA sequencing revealed that 295 miRNAs were upregulated and 138 miRNAs were downregulated in exosomes of the diabetes and cataracts group (DMC) compared with the age-related cataracts group (ARC), among which miR-551b was highly expressed with a log2 fold change of 5.99. GO and KEGG analyses indicated that the predicted genes were mainly involved in cadherin binding, proteoglycans in cancer and AGE-RAGE signalling pathway in diabetic complications. We then examined the function of miR-551b and found that miR-551b reduced the viability and increased the apoptosis of HLECs by downregulating CRYAA expression.

CONCLUSIONS

Exosomes isolated from human aqueous humour contained abundant miRNAs. A highly expressed miRNA, miR-551b, could regulate the functions of HLEC by targeting CRYAA.

METHODS

We pooled all the aqueous humour of each group into one sample and isolated exosomes from human aqueous humour by ultracentrifugation, measured the size and concentration of exosomes by nanoparticle tracking analysis (NTA), observed the morphology of exosomes by transmission electron microscopy (TEM), and sequenced exosomal miRNAs. We performed bioinformatic analysis of the sequencing results, including GO analysis and KEGG pathway enrichment. We then examined CRYAA mRNA expression levels and protein levels by quantitative real-time PCR and Western blot. Cell Counting Kit-8 and flow cytometry were applied to examine cell viability, proliferation and apoptosis.

Exosomes: Cell-Free Therapy for Cardiovascular Diseases

Cardiovascular diseases (CVDs) are an important cause of death and disease worldwide. Because injured cardiac tissue cannot be repaired itself, it is urgent to develop other alternate therapies. Stem cells can be differentiated into cardiomyocytes, endothelial cells, and vascular smooth muscle cells for the treatment of CVDs. Therefore, cell therapy has recently been considered a viable treatment option that can significantly improve cardiac function. Nonetheless, implanted stem cells rarely survive in the recipient heart, suggesting that the benefits of stem cell therapy may involve other mechanisms. Exosomes derived from stem cells have a myocardial protection function after myocardial injury, and may be a promising and effective therapy for CVDs. Here, we discuss the application and mechanism of exosomes derived from stem cells in the diagnosis and treatment of CVDs and provide evidence for the application of exosomes in CVDs. Graphical Abstract.

Altered levels of MALAT1 and H19 derived from serum or serum exosomes associated with type-2 diabetes

Environmental, genetic and epigenetic risk factors have been closely related to the development of type-2 diabetes (T2D). It has been reported that the expression in H19 and MALAT1 are related to metabolic diseases. To analyze the relationship between the expression of H19 and MALAT1 lncRNAs with diabetic patients. A study was conducted in subjects with T2D and nondiabetic controls, residents of Mexico City. Anthropometric measurements were made, and serum concentrations of glucose, glycosylated hemoglobin, total cholesterol, triglycerides, high- and low-density lipoprotein cholesterol were analyzed. Total RNA was extracted from serum and serum exosomes. The H19 and MALAT1 expression levels were quantified by RT-qPCR. A significant reduction in the expression of MALAT1 from serum or serum exosomes were found in patients with T2D, metabolic syndrome and low levels of HDL-c. Significant increase in H19 levels was found in diabetic subjects with poor glycemic control. Additionally, the principal component analyzes showed that serum MALAT1 expression was associated with total cholesterol and HDL-c levels, and the exosomes H19 expression was associated with waist circumference. The results obtained suggest that MALAT1 expression levels could be an epigenetic biomarker of diabetes risk or of its comorbidities.

Circulating exosomes may identify biomarkers for cows at risk for metabolic dysfunction

Disease susceptibility of dairy cows is greatest during the transition from pregnancy to lactation. Circulating exosomes may provide biomarkers to detect at-risk cows to enhance health and productivity. From 490 cows, animals at high- (n = 20) or low-risk (n = 20) of transition-related diseases were identified using plasma non-esterified fatty acid and β-hydroxybutyrate concentrations and liver triacylglyceride concentrations during the two weeks post-calving. We isolated circulating exosomes from plasma of dairy cows at low-risk (LR-EXO) and high-risk (HR-EXO), and analyzed their proteome profiles to determine markers for metabolic dysfunction. We evaluated the effects of these exosomes on eicosanoid pathway expression by bovine endometrial stromal (bCSC) and epithelial (bEEL) cells. HR-EXO had significantly lower yield of circulating exosomes compared with LR-EXO, and unique proteins were identified in HR-EXO and LR-EXO. Exposure to LR-EXO or HR-EXO differentially regulated eicosanoid gene expression and production in bCSC and bEEL cells. In bCSC, LR-EXO exposure increased PGE₂ and PGD₂ production, whereas HR-EXO exposure increased PTGS2 gene expression. In bEEL, HR-EXO exposure caused a decrease in PGE_2, PGF_2α, PGD₂, PGFM and TXB₂ production. The unique presence of serpin A3-7, coiled-coil domain containing 88A and inhibin/activin β A chain in HR-EXO, indicates potential biomarkers for cows at-risk for metabolic diseases. Our results are in line with the health status of the cow indicating a potential diagnostic role for exosomes in enhancing cows’ health and fertility.

The potential of exosomes in the therapy of the cartilage and bone complications; emphasis on osteoarthritis

Osteoarthritis is a prevalent worldwide joint disease, which demonstrates a remarkable adverse effect on the patients' life modality. Medicinal agents, exclusively nonsteroidal anti-inflammatory drugs (NSAIDs), have been routinely applied in the clinic. But, their effects are restricted to pain control with insignificant effects on cartilage renovation, which would finally lead to cartilage destruction. In the field of regenerative medicine, many researchers have tried to use stem cells to repair tissues and other human organs. However, in recent years, with the discovery of extracellular microvesicles, especially exosomes, researchers have been able to offer more exciting alternatives on the subject. Exosomes and microvesicles are derived from different types of bone cells such as mesenchymal stem cells, osteoblasts, and osteoclasts. They are also recognized to play substantial roles in bone remodeling processes including osteogenesis, osteoclastogenesis, and angiogenesis. Specifically, exosomes derived from a mesenchymal stem cell have shown a great potential for the desired purpose. Exosomal products include miRNA, DNA, proteins, and other factors. At present, if it is possible to extract exosomes from various stem cells effectively and load certain products or drugs into them, they can be used in diseases, such as rheumatoid arthritis, osteoarthritis, bone fractures, and other diseases. Of course, to achieve proper clinical use, advances have to be made to establish a promising regenerative ability for microvesicles for treatment purposes in the orthopedic disorders. In this review, we describe the exosomes biogenesis and bone cell derived exosomes in the regenerate process of bone and cartilage remodeling.

Adipose-specific knockdown of Sirt1 results in obesity and insulin resistance by promoting exosomes release

Sirtuin1 (SIRT1) has recently emerged as a pivotal regulator of glucose metabolism and insulin sensitivity. However, the underlying mechanism has not been fully elucidated. In this study, we investigated the role of SIRT1 in the development of obesity and insulin resistance by generating mice with adipose-specific ablation of Sirt1 (Ad-Sirt1^-/- mice). Ad-Sirt1^-/- mice exhibited increased fat mass, impaired glucose tolerance, attenuated insulin sensitivity, and increased exosomes, whereas the administration of exosomes inhibitor effectively ameliorated the impaired metabolic profile in Ad-Sirt1^-/- mice. Moreover, the increased exosomes were proved to be a result of defective autophagy activity in Ad-Sirt1^-/- mice and restoration of SIRT1 activity efficiently improved metabolic profiles in vitro. Further study demonstrated that Sirt1 deficiency-induced exosomes modulated insulin sensitivity at least partially via the TLR4/NF-κB signaling pathway. Therefore, our findings implicated SIRT1 as a key factor in metabolic regulation, and adipose Sirt1 deficiency could exert an effect on the development of obesity and insulin resistance by promoting exosome release.

Exosomal miR-214 from endometrial stromal cells inhibits endometriosis fibrosis

STUDY QUESTION

Is it possible to improve fibrosis in endometriosis by microRNA-214 delivery in exosomes?

SUMMARY ANSWER

Upregulation of miR-214 may inhibit fibrogenesis and its delivery by exosomes derived from ectopic endometrial stromal cells (ESCs), offers an alternative therapeutic approach for endometriosis fibrosis.

WHAT IS KNOWN ALREADY

Fibrosis is the primary pathological feature of endometriosis. MiR-214 plays an important role in fibrotic disease. Connective tissue growth factor (CTGF) is a critical fibrogenic mediator of miR-214. The expression of miR-214 is decreased in ectopic ESCs compared with normal ESCs. miRNAs are a natural cargo of exosomes and these could be exploited as carriers of miRNA in replacement therapy.

STUDY DESIGN, SIZE, DURATION

Paired eutopic and ectopic endometrial tissue samples were obtained from 10 women with ovarian endometrioma. ESCs and epithelial cells from both were cultured in vitro. RT-PCR, western blot and immunohistochemistry were used to study the effect of transfection with miR-214 mimics on CTGF expression and fibrogenesis respectively, with and without TGFβ stimulation. Exosomes were isolated from ectopic ESCs and Endometrioma tissue was isolated from four patients, dispersed an injected (ip) into nude mice and allowed to implant. The mice were treated with miR-214-enriched exosomes or controls to confirm the effect of inhibiting CTGF overexpression on endometriosis fibrosis.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The primary ectopic ESCs were transfected with miR-214 mimics. The levels of miR-214, CTGF and fibrotic markers were measured by RT-PCR and Immunohistochemistry. A mouse model of endometriosis was established by ip injection of human ectopic endometrial tissues into nude mice. MiR-214-enriched exosomes were injected into the mice and endometriotic lesions were measured on Day 28. Changes in fibrosis of the endometriotic implants were studied by histopathological staining.

MAIN RESULTS AND THE ROLE OF CHANCE

CTGF and fibrotic markers upregulation in endometriosis is associated with a reciprocal down-regulation of miR-214. By using miR-214 mimics and antagomirs to investigate expression of fibrotic markers, we found that increased production of miR-214 reduced Collagen αI and CTGF expression in endometriosis stromal and endometrial epithelial cells in response to fibrosis-inducing stimuli (P < 0.001 versus non-treatment). Ectopic ESCs yielded nano-sized exosomes which expressed miR-214. Loading exosomes with miR-214 mimics and injecting them into an experimental endometriosis mouse model resulted in a decrease in the expression of fibrosis-associated proteins (P < 0.001 versus PBS control group).

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

We only isolated exosomes from ectopic ESCs, whether this is the optimum source requires further study.

WIDER IMPLICATIONS OF THE FINDINGS

Upregulation of miRNA-214 potentially offers an alternative therapeutic approach for endometriosis fibrosis.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by grants from the National Natural Science Foundation of China (Grant no. 81771549 Jinwei Miao). The authors declare that there is no conflict of interest.

Serum miR-17 levels are downregulated in obese, African American women with elevated HbA1c

Purpose

Type 2 diabetes is heterogeneous disease characterized by several conditions including hyperglycemia. It is estimated that over 350 million people worldwide are suffering from type 2 diabetes and this number is expected to rise. According to the CDC, African Americans were observed to have a 40% higher incidence of diabetes compared to European Americans. Epigenetic modulating mechanisms such as microRNAs (miRNAs), have recently been established as a massive regulatory machine in metabolic syndrome, obesity and type 2 diabetes. In the present study, we aimed to investigate the serum levels of circulating miRNA 17 (miR-17) of obese, African American women with elevated HbA_1c.

Methods

We investigated miR-17 serum levels using qPCR. Then we used Pairwise Pearson Correlation Test to determine the relationship between clinical metabolic parameters and miR-17 serum levels.

Results

The results indicated that participants with elevated HbA_1c exhibited a down regulation of serum miR-17 levels compared to participants with normal HbA_1c. MiR-17 was also correlated with serum calcium in participants with normal HbA_1c.

Conclusions

The results suggest that serum miR-17 is involved in the regulation of glucose and calcium homeostasis, which may contribute to the development of type 2 diabetes.

Exosome and Macrophage Crosstalk in Sleep-Disordered Breathing-Induced Metabolic Dysfunction

Obstructive sleep apnea (OSA) is a highly prevalent worldwide public health problem that is characterized by repetitive upper airway collapse leading to intermittent hypoxia, pronounced negative intrathoracic pressures, and recurrent arousals resulting in sleep fragmentation. Obesity is a major risk factor of OSA and both of these two closely intertwined conditions result in increased sympathetic activity, oxidative stress, and chronic low-grade inflammation, which ultimately contribute, among other morbidities, to metabolic dysfunction, as reflected by visceral white adipose tissue (VWAT) insulin resistance (IR). Circulating extracellular vesicles (EVs), including exosomes, are released by most cell types and their cargos vary greatly and reflect underlying changes in cellular homeostasis. Thus, exosomes can provide insights into how cells and systems cope with physiological perturbations by virtue of the identity and abundance of miRNAs, mRNAs, proteins, and lipids that are packaged in the EVs cargo, and are secreted from the cells into bodily fluids under normal as well as diseased states. Accordingly, exosomes represent a novel pathway via which a cohort of biomolecules can travel long distances and result in the modulation of gene expression in selected and targeted recipient cells. For example, exosomes secreted from macrophages play a critical role in innate immunity and also initiate the adaptive immune response within specific metabolic tissues such as VWAT. Under normal conditions, phagocyte-derived exosomes represent a large portion of circulating EVs in blood, and carry a protective signature against IR that is altered when secreting cells are exposed to altered physiological conditions such as those elicited by OSA, leading to emergence of IR within VWAT compartment. Consequently, increased understanding of exosome biogenesis and biology should lead to development of new diagnostic biomarker assays and personalized therapeutic approaches. Here, the evidence on the major biological functions of macrophages and exosomes as pathophysiological effectors of OSA-induced metabolic dysfunction is discussed.

lncRNA-HEIH in serum and exosomes as a potential biomarker in the HCV-related hepatocellular carcinoma

BACKGROUND

Chronic hepatitis C (CHC) is a contagious liver disease that results from infection with the hepatitis C virus (HCV). The most serious consequence of CHC is HCV-related hepatocellular carcinoma (HCC).

OBJECTIVE

To illustrate the clinical significance of lncRNA HEIH expression in serum and exosomes in the development of HCV-related HCC.

METHODS

Thirty-five CHC, twenty-two HCV-induced cirrhosis and ten HCV-related HCC patients in Huzhou Central Hospital from January 2016 to September 2016 were recruited in the present study. Basic patient information, clinical serological indicators, and clinical imaging data were investigated and analyzed. Serum samples were collected from patients after receiving informed consent. Exosomes were extracted from the serum, and electron microscopy was used to observe the ultrastructure of exosomes. Quantitative PCR was used to detect lncRNA HEIH gene expression in serum and exosomes.

RESULTS

The changes in the ALT, GGT, HDL, INR, Alb and AFP levels in the patients with HCV-induced cirrhosis and HCV-related HCC were statistically significant. In patients with HCV-related HCC, lncRNA-HEIH expression in serum and exosomes was increased, but the ratio of lncRNA-HEIH expression in serum versus exosomes was decreased compared to patients with CHC.

Exosomes and regenerative medicine: state of the art and perspectives

Exosomes have attracted the attention of the scientific community in recent years due to their widespread distribution, their possible functions as biomarkers of disease, and their great potential to be applied as therapeutic agents. Exosomes carry proteins and nucleic acids that can facilitate their uptake by distant target cells through endocytosis, such that exosomes could be targeted to a specific cell or cells to enhance or interfere with specific biological processes. This review will mainly focus on their roles in tissue repair and regenerative processes. Exosomal engineering and their potential applications in tissue regeneration are also reviewed here as an outlook for future research.

Liquid biopsy in pancreatic cancer: the beginning of a new era

With dismal survival rate pancreatic cancer remains one of the most aggressive and devastating malignancy. Predominantly, due to the absence of a dependable methodology for early identification and limited therapeutic options for advanced disease. However, it takes over 17 years to develop pancreatic cancer from initiation of mutation to metastatic cancer; therefore, if diagnosed early; it may increase overall survival dramatically, thus, providing a window of opportunity for early detection. Recently, genomic expression analysis defined 4 subtypes of pancreatic cancer based on mutated genes. Hence, we need simple and standard, minimally invasive test that can monitor those altered genes or their associated pathways in time for the success of precision medicine, and liquid biopsy seems to be one answer to all these questions. Again, liquid biopsy has an ability to pair with genomic tests. Additionally, liquid biopsy based development of circulating tumor cells derived xenografts, 3D organoids system, real-time monitoring of genetic mutations by circulating tumor DNA and exosome as the targeted drug delivery vehicle holds lots of potential for the treatment and cure of pancreatic cancer. At present, diagnosis of pancreatic cancer is frantically done on the premise of CA19-9 and radiological features only, which doesn't give a picture of genetic mutations and epigenetic alteration involved. In this manner, the current diagnostic paradigm for pancreatic cancer diagnosis experiences low diagnostic accuracy. This review article discusses the current state of liquid biopsy in pancreatic cancer as diagnostic and therapeutic tools and future perspectives of research in the light of circulating tumor cells, circulating tumor DNA and exosomes.

Summary of the ISEV workshop on extracellular vesicles as disease biomarkers, held in Birmingham, UK, during December 2017

This report summarises the presentations and activities of the ISEV Workshop on extracellular vesicle biomarkers held in Birmingham, UK during December 2017. Among the key messages was broad agreement about the importance of biospecimen science. Much greater attention needs to be paid towards the provenance of collected samples. The workshop also highlighted clear gaps in our knowledge about pre-analytical factors that alter extracellular vesicles (EVs). The future utility of certified standards for credentialing of instruments and software, to analyse EV and for tracking the influence of isolation steps on the structure and content of EVs were also discussed. Several example studies were presented, demonstrating the potential utility for EVs in disease diagnosis, prognosis, longitudinal serial testing and stratification of patients. The conclusion of the workshop was that more effort focused on pre-analytical issues and benchmarking of isolation methods is needed to strengthen collaborations and advance more effective biomarkers.

Proteomic content of circulating exosomes in dairy cows with or without uterine infection

In the past few decades, there has been a global decrease in dairy cow reproductive performance. An activated inflammatory system, due to uterine infection, has been associated with decreased cow fertility and as such, there is a need to detect uterine disease earlier. Early detection could be achieved by identifying biomarkers for uterine disease. Exosomes are small nanovesicles known to package and deliver protein, mRNA, and miRNAs to near and distant sites. Therefore, the content of circulating exosomes may have the potential to carry biomarkers for earlier diagnosis of disease. We hypothesized that circulating exosomes from cows with and without uterine infection may contain information representative of endometrial health or disease. We compared the proteomic content of circulating exosomes derived from plasma of dairy cows with (n = 10) or without (n = 10) induced uterine infection, using high-performance liquid chromatography tandem mass spectrometry (HPLC MS/MS). Our results demonstrate that there were a total of 103 bovine and 9 Trueperella pyogenes proteins found in plasma exosomes derived from infected cows (infected exosomes), and 90 bovine and 5 T. pyogenes proteins found in exosomes derived from plasma of non-infected cows (non-infected exosomes). 71 bovine proteins were found to be unique to the infected exosomes while only 4 bovine proteins were found to be unique to the non-infected exosomes. 8 unique T. pyogenes proteins were identified in infected exosomes and 4 were found to be unique to the non-infected exosomes. Pathway analysis showed that infected exosomes had more proteins involved in structural molecule activity and immune system processes than non-infected exosomal protein. Additionally, proteins from infected exosomes were involved in unique pathways: angiogenesis and integrin signaling pathway. Our data provide preliminary evidence of a potential role for exosomes in the early diagnosis of uterine infection in dairy cows.

Exosomes: Nanocarriers of Biological Messages

Cell-cell communication is crucial to maintain homeostasis in multicellular organism. Cells communicate each other by direct contact or by releasing factors that, soluble or packaged in membrane vesicles, can reach different regions of the organism. To date numerous studies highlighted the existence of several types of extracellular vesicles that, differing for dimension, origin and contents, play a role in physiological and/or pathological processes. Among extracellular vesicles, exosomes are emerging as efficient players to modulate target cells phenotype and as new non-invasive diagnostic and prognostic tools in multiple diseases. They, in fact, strictly reflect the type and functional status of the producing cells and are able to deliver their contents even over a long distance. The results accumulated in the last two decades and collected in this chapter, indicated that exosomes, can carry RNAs, microRNAs, long non-coding RNAs, DNA, lipids, metabolites and proteins; a deeper understanding of their contents is therefore needed to get the most from this incredible cell product.

Exosomes: Outlook for Future Cell-Free Cardiovascular Disease Therapy

Cardiovascular diseases are the number one cause of death globally with an estimated 7.4 million people dying from coronary heart disease. Studies have been conducted to identify the therapeutic utility of exosomes in many diseases, including cardiovascular diseases. It has been demonstrated that exosomes are immune modulators, can be used to treat cardiac ischemic injury, pulmonary hypertension and many other diseases, including cancers. Exosomes can be used as a biomarker for disease and cell-free drug delivery system for targeting the cells. Many studies suggest that exosomes can be used as a cell-free vaccine for many diseases. In this chapter, we explore the possibility of future therapeutic potential of exosomes in various cardiovascular diseases.

C-Terminal Farnesylation of UCH-L1 Plays a Role in Transport of Epstein-Barr Virus Primary Oncoprotein LMP1 to Exosomes

Exosomes are small vesicles that cells secrete into the extracellular space, and there is increasing evidence that they have pivotal roles in cell-to-cell communication in malignancy. It is reported also that EBV-associated malignant cells, including those derived from nasopharyngeal carcinoma (NPC) and B-cell lymphoma, secrete exosomes. These EBV-related exosomes may contain viral products such as latent membrane protein 1 (LMP1) and may contribute to cancer progression. The aim of this study was to investigate the mechanism by which those viral products are loaded in exosomes. In this study, we show for the first time that ubiquitin C-terminal hydrolase-L1 (UCH-L1) and its C-terminal farnesylation, a posttranslational lipid modification, contribute to this mechanism. Our results also suggest that inhibition of UCH-L1 farnesylation is a potential therapeutic target against cancer metastasis and invasion.

Increasing evidence shows that exosomes are key regulators in cancer cell-to-cell communication. Several reports on Epstein-Barr virus (EBV)-related malignancies demonstrate that latent membrane protein 1 (LMP1) secreted by exosomes derived from EBV- or LMP1-positive cells can promote cancer progression and metastasis. However, the mechanism by which LMP1 is loaded into exosomes is still poorly understood. Here, we examined whether the process of LMP1 loading into exosomes is linked to the multifunctional molecule of the ubiquitin system—ubiquitin C-terminal hydrolase-L1 (UCH-L1). For the first time, we demonstrate that LMP1 is physically associated with UCH-L1 and that directing of LMP1 to exosomes is mediated by C-terminal farnesylation of UCH-L1. Additionally, we found that the FTI-277 farnesyltransferase inhibitor reduces motility- and anchorage-independent growth of EBV-positive cells in functional assays. On the basis of our results, we conclude that C-terminal farnesylation of UCH-L1 is one of the key mechanisms by which LMP1 is sorted to exosomes. We hypothesize that inhibition of farnesylation with specific small-molecule inhibitors blocks exosome-mediated transfer of prometastatic molecules such as LMP1 during cancer cell-to-cell communications and thereby impedes the process of cancer invasion.

IMPORTANCE Exosomes are small vesicles that cells secrete into the extracellular space, and there is increasing evidence that they have pivotal roles in cell-to-cell communication in malignancy. It is reported also that EBV-associated malignant cells, including those derived from nasopharyngeal carcinoma (NPC) and B-cell lymphoma, secrete exosomes. These EBV-related exosomes may contain viral products such as latent membrane protein 1 (LMP1) and may contribute to cancer progression. The aim of this study was to investigate the mechanism by which those viral products are loaded in exosomes. In this study, we show for the first time that ubiquitin C-terminal hydrolase-L1 (UCH-L1) and its C-terminal farnesylation, a posttranslational lipid modification, contribute to this mechanism. Our results also suggest that inhibition of UCH-L1 farnesylation is a potential therapeutic target against cancer metastasis and invasion.

Placental exosomes: A proxy to understand pregnancy complications

Exosomes (30- to 150-nm particles), originating from multivesicular bodies by the invagination of the endosomal membrane, are communication channels between cells. Exosomes are released by various cell types and cargo proteins, lipids, and nucleic acids reflecting the physiologic status of their cells of origin and cause functional changes in recipient cells, which are likely dependent on their quantity and/or cargo contents. Recently, placental exosomes, produced by various placental cell types, have been isolated from maternal blood using the placental protein-specific marker, placental alkaline phosphatase (PLAP). PLAP-positive exosomes are seen in maternal blood as early as the first trimester of pregnancy and increase as gestation progresses, with maximum numbers seen at term. Although the functional relevance of placental exosomes is still under investigation, several studies have linked placental exosomes changes (quantity and cargo) reflecting placental dysfunctions associated with adverse pregnancy events. As placental exosomes can be isolated from maternal blood, they are liquid biopsies reflecting placental functions. Hence, they are useful as biomarkers of placental functions and dysfunctions obtainable through non-invasive approaches. This review summarizes the biogenesis, release, and functions of exosomes and specifically expounds the role of placental-specific exosomes and their significance associated with pregnancy complications.

Lipidomic and proteomic analysis of exosomes from mouse cortical collecting duct cells

Exosomes are endosome-derived nanovesicles that are involved in cellular communication and signaling. Exosomes are produced by epithelial cells and are found in biologic fluids including blood and urine. The packaged material within exosomes includes proteins and lipids, but the molecular comparison within exosome subtypes is largely unknown. The purpose of this study was to investigate differences between exosomes derived from the apical plasma membrane and basolateral plasma membrane of polarized murine cortical collecting duct principal cells. Nanoparticle tracking analysis showed that the size and concentration of apical and basolateral exosomes remained relatively stable across 3 different temperatures (23, 37, and 42°C). Liquid chromatography-tandem mass spectrometry analysis revealed marked differences between the proteins packaged within the two types of exosomes from the same cells. Several proteins expressed at the inner leaflet of the plasma membrane, including α-actinin-1, moesin, 14-3-3 protein ζ/δ, annexin A1/A3/A4/A5/A6, clathrin heavy chain 1, glyceraldehyde-3-phosphate dehydrogenase, α-enolase, filamin-A, and heat shock protein 90, were identified in samples of apical plasma membrane-derived exosomes, but not in basolateral plasma membrane exosomes from mouse cortical collecting duct cells. In addition to differences at the protein level, mass spectrometry-based shotgun lipidomics analysis showed significant differences in the lipid classes and fatty acid composition of the two types of exosomes. We found higher levels of sphingomyelin and lower levels of cardiolipin, among other phospholipids in the apical plasma membrane compared to the basolateral plasma membrane exosomes. The molecular analyses of exosome subtypes presented herein will contribute to our understanding of exosome biogenesis, and the results may have potential implications for biomarker discovery.-Dang, V. D., Jella, K. K., Ragheb, R. R. T., Denslow, N. D., Alli, A. A. Lipidomic and proteomic analysis of exosomes from mouse cortical collecting duct cells.

Emerging MS-based platforms for the characterization of tumor-derived exosomes isolated from human biofluids: challenges and promises of MudPIT

INTRODUCTION

Exosomes are small extracellular vesicles of endosomal origin that are produced and released by several type of cells. These vesicles contain different macromolecules: proteins, mRNA, miRNA, mitochondrial DNA, and lipids. Exosomes play an important role in cell-to-cell communication, also promoting cancer progression. Areas covered: Various proteomic approaches have been applied to study exosomes isolated from different human biofluids in search of possible cancer biomarkers. The results of these studies are reported, and pros and cons of each employed technique are described. Gel-free and gel-based mass spectrometry systems are discussed, giving particular emphasis on the innovative multidimensional protein identification technology (MudPIT). Expert commentary: Proteomic studies on exosomes as candidate cancer biomarkers from urine and other body fluids in cancer have shown the potential of MS-based techniques. In particular, MudPIT is a promising tool to be applied in clinical proteomics of cancer.

Exosomes derived from pancreatic cancer cells induce insulin resistance in C2C12 myotube cells through the PI3K/Akt/FoxO1 pathway

Prospective epidemiological studies have consistently suggested that pancreatic cancer-associated new-onset diabetes mellitus (PC-DM) represents a potential platform for early diagnose of pancreatic cancer (PC). Despite the studies performed, the mechanism behind this phenomenon remains ambiguous. In this study, we explored the effects of two types of exosomes released by murine pancreatic cancer and ductal epithelial cells on murine skeletal muscle cells. The results show that PC-derived exosomes can readily enter C2C12 myotubes, triggering lipidosis and glucose intake inhibition. We also demonstrate that PC-derived exosomes can inhibit insulin and PI3K/Akt signalling, in which insulin-induced FoxO1 nuclear exclusion is preserved and Glut4 trafficking is impaired. Microarray and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses show that exosomal microRNAs (miRNAs) probably play key roles in this process, an assumption that is corroborated by in vitro studies. These results confirm that the insulin resistance (IR) of skeletal muscle cells is governed by PC-derived exosomes through the insulin and PI3K/Akt/FoxO1 signalling pathways, where exosomal miRNAs potentially contribute to this phenomenon. These novel findings pave the way towards a comprehensive understanding of the cancer theories: "metabolic reprogramming" and "metabolic crosstalk".

A Systematic Study of Dysregulated MicroRNA in Type 2 Diabetes Mellitus

MicroRNAs (miRNAs) are small noncoding RNAs that modulate the cellular transcriptome at the post-transcriptional level. miRNA plays important roles in different disease manifestation, including type 2 diabetes mellitus (T2DM). Many studies have characterized the changes of miRNAs in T2DM, a complex systematic disease; however, few studies have integrated these findings and explored the functional effects of the dysregulated miRNAs identified. To investigate the involvement of miRNAs in T2DM, we obtained and analyzed all relevant studies published prior to 18 October 2016 from various literature databases. From 59 independent studies that met the inclusion criteria, we identified 158 dysregulated miRNAs in seven different major sample types. To understand the functional impact of these deregulated miRNAs, we performed targets prediction and pathway enrichment analysis. Results from our analysis suggested that the altered miRNAs are involved in the core processes associated with T2DM, such as carbohydrate and lipid metabolisms, insulin signaling pathway and the adipocytokine signaling pathway. This systematic survey of dysregulated miRNAs provides molecular insights on the effect of deregulated miRNAs in different tissues during the development of diabetes. Some of these miRNAs and their mRNA targets may have diagnostic and/or therapeutic utilities in T2DM.