Circulating exosome-like vesicles of humans with nondiabetic obesity impaired islet β-cell proliferation, which was associated with decreased Omentin-1 protein cargo

Omentin-1 and diabetes: more evidence but far from enough

AIMS AND BACKGROUND

Omentin-1 (oment-1) is a type of adipokines that is mainly expressed in visceral fat tissue. Based on accumulating evidence, oment-1 is closely related to diabetes and its complications. However, so far data about oment-1 and diabetes is fragmented. In this review, we focus on the role of oment-1 on diabetes, including its possible signalling pathways, the correlation of circulating omens-1 levels with diabetes and its complications.

METHODS

The web of PubMed was searched for articles of relevant studies published until February, 2023.

RESULTS AND CONCLUSIONS

Oment-1 might exert its effects by inhibiting the NF-κB pathway and activating the Akt and AMPK-dependent pathways. The level of circulating oment-1 is negatively correlated with the occurrence of type 2 diabetes and some complications, including diabetic vascular disease, cardiomyopathy, and retinopathy, which can be affected by anti-diabetic therapies. Oment-1 could be a promising marker for screening and targeted therapy for diabetes and its complications; however, more studies are still needed.

miR-486-5p-rich extracellular vesicles derived from patients with olanzapine-induced insulin resistance negatively affect glucose-regulating function

A high risk of glucometabolic disorder severely disturbs compliance and limits the clinical application of olanzapine. MicroRNAs (miRNAs) in extracellular vesicles (EVs) have been reported as emerging biomarkers in glucolipid metabolic disorders. A total of 81 individuals with continuous olanzapine treatment over 3 months were recruited in this study, and plasma EVs from these individuals were isolated and injected into rats via the tail vein to investigate the glucose-regulating function in vivo. Moreover, we performed a miRNA profiling assay by high through-put sequencing to clarify the differentiated miRNA profiles between two groups of patients who were either susceptible or not susceptible to olanzapine-induced insulin resistance (IR). Finally, we administered antagomir and cocultured them with adipocytes to explore the mechanism in vitro. The results showed that individual insulin sensitivity varied in those patients and in olanzapine-administered rats. Furthermore, treatment with circulating EVs from patients with olanzapine-induced IR led to the development of metabolic abnormalities in rats and adipocytes in vitro through the AKT-GLUT4 pathway. Deep sequencing illustrated that the miRNAs of plasma EVs from patients showed a clear difference based on susceptibility to olanzapine-induced IR, and miR-486-5p was identified as a notable gene. The adipocyte data indicated that miR-486-5p silencing partially reversed the impaired cellular insulin sensitivity. Collectively, this study confirmed the function of plasma EVs in the interindividual differences in olanzapine-induced insulin sensitivity.

The Role of Extracellular Vesicles in Metabolic Diseases

Extracellular vesicles represent a group of structures with the capacity to communicate with different cells and organs. This complex network of interactions can regulate multiple physiological processes in the organism. Very importantly, these processes can be altered during the appearance of different diseases including cancer, metabolic diseases, etc. In addition, these extracellular vesicles can transport different cargoes, altering the initiation of the disease, driving the progression, or even accelerating the pathogenesis. Then, we have explored the implication of these structures in different alterations such as pancreatic cancer, and in different metabolic alterations such as diabetes and its complications and non-alcoholic fatty liver disease. Finally, we have explored in more detail the communication between the liver and the pancreas. In summary, extracellular vesicles represent a very efficient system for the communication among different tissues and permit an efficient system as biomarkers of the disease, as well as being involved in the extracellular-vesicle-mediated transport of molecules, serving as a potential therapy for different diseases.

A Pilot Study on the Proteomics Profile of Serum Exosome-Enriched Extracellular Vesicles from Normal versus Individuals with Obesity-Related Insulin Resistance

OBJECTIVE

Circulating exosome-enriched extracellular vesicles (EVs) have drawn considerable importance in obesity-related insulin-resistance (IR). We sought to compare the proteomics profile of serum exosomes from normal individuals and those with obesity and IR.

METHODS

We isolated serum exosomes from male subjects with obesity and insulin resistance (Ob-IR, HOMA-IR > 2.0) and lean/overweight insulin-sensitive (Normal (N), HOMA-IR < 2.0) individuals. The differential protein expression between the two groups was detected by a label-free quantitative mass spectrometry analysis followed by GO annotation and ingenuity pathway analysis (IPA).

RESULTS

We identified 23 upregulated and 46 downregulated proteins between Ob-IR and N groups. Some of these proteins are involved in altering insulin signaling (VPS13C, TBC1D32, TTR, and ADIPOQ), inflammation (NFκB and CRP), and B-cell proliferation/activation (IGLV4-69, IGKV1D-13, and IGHV4-28). GO analysis revealed that the differentially expressed proteins (DEPs) are mainly involved in regulating immune cell activation and are located in extracellular space. IPA analysis showed that top molecules mediating IR, inflammation and B-cell activation were upregulated in Ob-IR subjects compared to N subjects.

CONCLUSIONS

Serum exosomal proteins can be used as biomarkers to identify the future risk of diabetes and a therapeutic target to prevent or slow down the progression of diabetes in high-risk individuals.

Omentin: A Key Player in Glucose Homeostasis, Atheroprotection, and Anti-Inflammatory Potential for Cardiovascular Health in Obesity and Diabetes

Omentin is an adipokine mainly produced by visceral fat tissue. It has two isoforms, omentin-1 and omentin-2. Omentin-1 is predominantly secreted by visceral adipose tissue, derived specifically from the stromal vascular fraction cells of white adipose tissue (WAT). Levels of omentin-1 are also expressed in other WAT depots, such as epicardial adipose tissue. Omentin-1 exerts several beneficial effects in glucose homeostasis in obesity and diabetes. In addition, research has suggested that omentin-1 may have atheroprotective (protective against the development of atherosclerosis) and anti-inflammatory effects, potentially contributing to cardiovascular health. This review highlights the potential therapeutic targets of omentin-1 in metabolic disorders.

An Overview of Inter-Tissue and Inter-Kingdom Communication Mediated by Extracellular Vesicles in the Regulation of Mammalian Metabolism

Obesity and type 2 diabetes are associated with defects of insulin action in different tissues or alterations in β-cell secretory capacity that may be triggered by environmental challenges, inadequate lifestyle choices, or an underlying genetic predisposition. In addition, recent data shows that obesity may also be caused by perturbations of the gut microbiota, which then affect metabolic function and energy homeostasis in the host. Maintenance of metabolic homeostasis in complex organisms such as mammals requires organismal-level communication, including between the different organs and the gut microbiota. Extracellular vesicles (EVs) have been identified in all domains of life and have emerged as crucial players in inter-organ and inter-kingdom crosstalk. Interestingly, EVs found in edible vegetables or in milk have been shown to influence gut microbiota or tissue function in mammals. Moreover, there is a multidirectional crosstalk mediated by EVs derived from gut microbiota and body organs that has implications for host health. Untangling this complex signaling network may help implement novel therapies for the treatment of metabolic disease.