Miruna Nemecz

Background/Objectives: The treatment of patients with advanced peripheral arterial disease, such as chronic limb-threatening ischemia (CLTI), often requires more than the use of conventional vasodilators and revascularization procedures, when these are feasible. Alprostadil is typically administered intravenously to treat these patients. However, existing studies reported conflicting results regarding the efficacy of the aforementioned treatment. It is hypothesized that, based on clinical experience, this therapy may exhibit a benefit for patients with CLTI, promoting ulcer healing, alleviating pain, and improving limb salvage rates. Consequently, the concept of employing blood-circulating microvesicles (MVs) as biomarkers for evaluating treatment effectiveness and estimating clinical prognoses has been proposed. Methods: These were analyzed in a group of patients with CLTI before and during alprostadil treatment, with and without revascularization procedures, to assess their correlation with clinical outcomes. Results: Our data indicated that CLTI results in an increase in circulating levels of MVs, as well as in specific subtypes of plasma MVs—MVs derived from endothelial cells (EMVs), platelets (PMVs), leukocytes (LeMVs), monocytes (MMVs), and erythrocytes (ErMVs)—compared to levels observed in the plasma of healthy individuals. Furthermore, treatment with alprostadil was associated with a significant reduction in plasma levels of total MVs, as well as EMVs, PMVs, LeMVs, and MMVs. In contrast, revascularization procedures do not appear to result in a reduction in circulating MV levels. These results are consistent with the clinical improvements observed in CLTI patients treated with alprostadil. Conclusions: In summary, the findings of this preliminary study suggest that blood-circulating MVs, including specific subtypes such as EMVs, PMVs, LeMVs, and MMVs, may have potential as biomarkers for assessing the response to alprostadil treatment in patients with CLTI.

(1) Background: The present study investigated the effects of extracellular vesicles (EVs), derived from adipose tissue stem cells (ADSCs) and bone marrow mesenchymal stem cells (BMMSCs), on atherosclerosis-associated cardiac hypertrophy. (2) Methodology: The experiments were performed on hamsters divided into the following groups: control (C) fed with a standard diet; hypertensive–hyperlipidemic (HH) generated by combining a diet enriched with 3% cholesterol, 15% butter, and by gavage with 8% NaCl on a daily basis; HH groups injected with EVs (ADSCs) or EVs (BMMSCs), either transfected with Smad2/3 siRNAs or not (HH-EVs (ADSCs), HH-EVs (BMMSCs), HH-EVs (ADSCs) + Smad2/3siRNA, HH-EVs (BMMSCs) + Smad2/3siRNA); and HH group injected with Smad2/3 siRNAs (HH-Smad2/3siRNA). (3) Results: In comparison with the HH group, the findings demonstrated that treatment using EVs (ADSCs or BMMSCs), either with or without Smad2/3 siRNAs, resulted in several significant improvements in the following aspects: the plasma levels of cholesterol, LDL, triglycerides, TGF-β1, and Ang II were decreased; the left ventricular structure and function were recovered; inflammatory markers, ROS, COL1A, α-SMA, Cx43, MIF, ANF, and M1/M2 macrophages, were reduced; the level of key protein NF-κB p50 was diminished. (4) Conclusions: These findings underscore the therapeutic potential of mesenchymal stem cell-derived EVs in atherosclerosis-associated cardiac hypertrophy.

Background: Circulating MicroRNAs (miRNAs) carried by microvesicles (MVs) have various physiological and pathological functions by post-transcriptional regulation of gene expression being considered markers for many diseases including diabetes and dyslipidemia. We aimed to identify new common miRNAs both in MVs and plasma that could be predictive biomarkers for diabetic dyslipidemia evolution. Methods: For this purpose, plasma from 63 participants in the study (17 type 2 diabetic patients, 17 patients with type 2 diabetes and dyslipidemia, 14 patients with dyslipidemia alone and 15 clinically healthy persons without diabetes or dyslipidemia) was used for the analysis of circulating cytokines, MVs, miRNAs and MV-associated miRNAs. Results: The results uncovered three miRNAs, miR-218, miR-132 and miR-143, whose expression was found to be significantly up-regulated in both circulating MVs and plasma from diabetic patients with dyslipidemia. These miRNAs showed significant correlations with important plasma markers, representative of this pathology. Thus, MV/plasma miR-218 was negatively correlated with the levels of erythrocyte MVs, plasma miR-132 was positively connected with MV miR-132 and negatively with uric acid and erythrocyte plasma levels, and plasma miR-143 was negatively related with creatinine levels and diastolic blood pressure. Also, three miRNAs common to MV and plasma, namely miR-21, miR-122, and miR-155, were identified to be down-regulated and up-regulated, respectively, in diabetic dyslipidemia. In addition, MV miR-21 was positively linked with cholesterol plasma levels and plasma miR-21 with TNFα plasma levels, MV miR-122 was negatively correlated with LDL-c levels and plasma miR-122 with creatinine and diastolic blood pressure and positively with MV miR-126 levels, MV miR-155 was positively associated with cholesterol and total MV levels and negatively with HDL-c levels, whereas plasma miR-155 was positively correlated with Il-1β plasma levels and total MV levels and negatively with MV miR-223 levels. Conclusions: In conclusion, miR-218, miR-132, miR-143, and miR-21, miR-122, miR-155 show potential as biomarkers for diabetic dyslipidemia, but there is a need for more in-depth studies. These findings bring new information regarding the molecular biomarkers specific to diabetic dyslipidemia and could have important implications for the treatment of patients affected by this pathology.

Glioblastoma (GB) is the most aggressive and recurrent form of brain cancer in adults. We hypothesized that the identification of biomarkers such as certain microRNAs (miRNAs) and the circulating microvesicles (MVs) that transport them could be key to establishing GB progression, recurrence and therapeutic response. For this purpose, circulating MVs were isolated from the plasma of GB patients (before and after surgery) and of healthy subjects and characterized by flow cytometry. OpenArray profiling and the individual quantification of selected miRNAs in plasma and MVs was performed, followed by target genes’ prediction and in silico survival analysis. It was found that MVs’ parameters (number, EGFRvIII and EpCAM) decreased after the surgical resection of GB tumors, but the inter-patient variability was high. The expression of miR-106b-5p, miR-486-3p, miR-766-3p and miR-30d-5p in GB patients’ MVs was restored to control-like levels after surgery: miR-106b-5p, miR-486-3p and miR-766-3p were upregulated, while miR-30d-5p levels were downregulated after surgical resection. MiR-625-5p was only identified in MVs isolated from GB patients before surgery and was not detected in plasma. Target prediction and pathway analysis showed that the selected miRNAs regulate genes involved in cancer pathways, including glioma. In conclusion, miR-625-5p shows potential as a biomarker for GB regression or recurrence, but further in-depth studies are needed.

Adipose tissue-derived stem cells (ADSCs) are pluripotent mesenchymal stem cells found in relatively high percentages in the adipose tissue and able to self-renew and differentiate into many different types of cells. “Extracellular vesicles (EVs), small membrane vesicular structures released during cell activation, senescence, or apoptosis, act as mediators for long distance communication between cells, transferring their specific bioactive molecules into host target cells”. There is a general consensus on how to define and isolate ADSCs, however, multiple separation and characterization protocols are being used in the present which complicate the results’ integration in a single theory on ADSCs’ and their derived factors’ way of action. Metabolic syndrome and type 2 diabetes mellitus (T2DM) are mainly caused by abnormal adipose tissue size, distribution and metabolism and so ADSCs and their secretory factors such as EVs are currently investigated as therapeutics in these diseases. Moreover, due to their relatively easy isolation and propagation in culture and their differentiation ability, ADSCs are being employed in preclinical studies of implantable devices or prosthetics. This review aims to provide a comprehensive summary of the current knowledge on EVs secreted from ADSCs both as diagnostic biomarkers and therapeutics in diabetes and associated cardiovascular disease, the molecular mechanisms involved, as well as on the use of ADSC differentiation potential in cardiovascular tissue repair and prostheses.

Extracellular vesicles (EVs) are particles released in the extracellular space from all cell types in physiological and pathological conditions and emerge as a new way of cell-cell communication by transferring their biological contents into target cells. The levels and composition of circulating EVs differ from a normal condition to a pathological one, making them real circulating biomarkers. EVs have a very complex contribution in both health and disease, most likely in relationship between diabetes and cardiovascular disease. The involvement of EVs to the development of cardiovascular complications in diabetes remains an open discussion for therapists. Circulating EVs may offer a continuous access path to circulating information on the disease state and a new perspective in finding a correct diagnosis, in estimating a prognosis and also in applying an effective therapy. Besides their role as biomarkers and targets for therapy, EVs can be exploited as biological tools in influencing the different processes affected in diabetic cardiovascular diseases. This chapter will summarize the current knowledge about EVs as biological vectors modulating diabetic cardiovascular diseases, including atherosclerosis, coronary artery disease, and peripheral arterial disease. Finally, we will point out EVs’ considerable value as clinical biomarkers, therapeutic targets, and potential biomedical tools for the discovery of effective therapy in diabetic cardiovascular diseases.

In this study, we aimed to identify the mechanisms underlying the different effects of palmitic acid and oleic acid on human pancreatic beta cell function. To address this problem, the oxidative stress, endoplasmic reticulum stress, inflammation, apoptosis and their mediator molecules have been investigated in the insulin releasing beta cells exposed to palmitic and/or oleic acid. Herein, we have demonstrated that in cultured 1.1B4 beta cells oleic acid promotes neutral lipid accumulation and insulin secretion, whereas palmitic acid is poorly incorporated into triglyceride and it does not stimulate insulin secretion from human pancreatic islets at physiologically glucose concentrations. In addition, palmitic acid caused: (1) oxidative stress through a mechanism involving increases in ROS production and MMP-2 protein expression/gelatinolytic activity associated with down-regulation of SOD2 protein; (2) endoplasmic reticulum stress by up-regulation of chaperone BiP protein and unfolded protein response (UPR) transcription factors (eIF2α, ATF6, XBP1u proteins) and by PTP-1B down-regulation in both mRNA and protein levels; (3) inflammation through enhanced synthesis of proinflammatory cytokines (IL6, IL8 proteins); and (4) apoptosis by enforced proteic expression of CHOP multifunctional transcription factor. Oleic acid alone had opposite effects due to its different capacity of controlling these metabolic pathways, in particular by reduction of the ROS levels and MMP-2 activity, down-regulation of BiP, eIF2α, ATF6, XBP1u, CHOP, IL6, IL8 and by SOD2 and PTP-1B overexpression. The supplementation of saturated palmitic acid with the monounsaturated oleic acid reversed the negative effects of palmitic acid alone regulating insulin secretion from pancreatic beta cells through ROS, MMP-2, ATF6, XBP1u, IL8 reduction and SOD2, PTP-1B activation. Our findings have shown the protective action of oleic acid against palmitic acid on beta cell lipotoxicity through promotion of triglyceride accumulation and insulin secretion and regulation of some effector molecules involved in oxidative stress, endoplasmic reticulum stress, inflammation and apoptosis.