Multicellular regulation of miR-196a-5p and miR-425-5 from adipose stem cell-derived exosomes and cardiac repair

MiR-196a-5p hinders vascular smooth muscle cell proliferation and vascular remodeling via repressing BACH1 expression

Hyperproliferation of vascular smooth muscle cells (VSMCs) is a driver of hypertensive vascular remodeling. This study aimed to uncover the mechanism of BTB and CNC homology 1 (BACH1) and microRNAs (miRNAs) in VSMC growth and hypertensive vascular remodeling. With the help of TargetScan, miRWalk, miRDB, and miRTarBase online database, we identified that BACH1 might be targeted by miR-196a-5p, and overexpressed in VSMCs and aortic tissues from spontaneously hypertensive rats (SHRs). Gain- and loss-of-function experiments demonstrated that miR-196a-5p suppressed VSMC proliferation, oxidative stress and hypertensive vascular remodeling. Double luciferase reporter gene assay and functional verification showed that miR-196a-5p cracked down the transcription and translation of BACH1 in both Wistar Kyoto rats (WKYs) and SHRs. Silencing BACH1 mimicked the actions of miR-196a-5p overexpression on attenuating the proliferation and oxidative damage of VSMCs derived from SHRs. Importantly, miR-196a-5p overexpression and BACH1 knockdown cooperatively inhibited VSMC proliferation and oxidative stress in SHRs. Furthermore, miR-196a-5p, if knocked down in SHRs, aggravated hypertension, upregulated BACH1 and promoted VSMC proliferation, all contributing to vascular remodeling. Taken together, targeting miR-196a-5p to downregulate BACH1 may be a promising strategy for retarding VSMC proliferation and hypertensive vascular remodeling.

Recent advances in the use of extracellular vesicles from adipose-derived stem cells for regenerative medical therapeutics

Adipose-derived stem cells (ADSCs) are a subset of mesenchymal stem cells (MSCs) isolated from adipose tissue. They possess remarkable properties, including multipotency, self-renewal, and easy clinical availability. ADSCs are also capable of promoting tissue regeneration through the secretion of various cytokines, factors, and extracellular vesicles (EVs). ADSC-derived EVs (ADSC-EVs) act as intercellular signaling mediators that encapsulate a range of biomolecules. These EVs have been found to mediate the therapeutic activities of donor cells by promoting the proliferation and migration of effector cells, facilitating angiogenesis, modulating immunity, and performing other specific functions in different tissues. Compared to the donor cells themselves, ADSC-EVs offer advantages such as fewer safety concerns and more convenient transportation and storage for clinical application. As a result, these EVs have received significant attention as cell-free therapeutic agents with potential future application in regenerative medicine. In this review, we focus on recent research progress regarding regenerative medical use of ADSC-EVs across various medical conditions, including wound healing, chronic limb ischemia, angiogenesis, myocardial infarction, diabetic nephropathy, fat graft survival, bone regeneration, cartilage regeneration, tendinopathy and tendon healing, peripheral nerve regeneration, and acute lung injury, among others. We also discuss the underlying mechanisms responsible for inducing these therapeutic effects. We believe that deciphering the biological properties, therapeutic effects, and underlying mechanisms associated with ADSC-EVs will provide a foundation for developing a novel therapeutic approach in regenerative medicine.

New insights of acylation stimulating protein in modulating the pathological progression of metabolic syndromes

Obesity is associated with insulin resistance, hypertension, and coronary artery diseases which are grouped as metabolic syndrome. Rather than being a storage for energy, the adipocytes could synthesis and secret diverse hormones and molecules, named as adipokines. Under obese status, the adipocytes are dysfunctional with excessively producing the inflammatory related cytokines, such as interleukin 1 (IL-1), IL-6, and tumor necrosis factor α (TNF-α). Concerning on the vital role of adipokines, it is proposed that one of the critical pathological factors of obesity is the dysfunctional adipocytic pathways. Among these adipokines, acylation stimulating protein, as an adipokine synthesized by adipocytes during the process of cell differentiation, is shown to activate the metabolism of triglyceride (TG) by regulating the catabolism of glucose and free fatty acid (FFA). Recent attention has paid to explore the underlying mechanism whereby acylation stimulating protein influences the biological function of adipocyte and the pathological development of obesity. In the present review, we summarized the progression of acylation stimulating protein in modulating the physiological and hormonal catabolism which affects fat distribution. Furthermore, the potential mechanisms which acylation stimulating protein regulates the metabolism of adipose tissue and the process of metabolic syndrome were also summarized.

Nascent shifts in renal cellular metabolism, structure, and function due to chronic empagliflozin in prediabetic mice

Sodium-glucose cotransporter, type 2 inhibitors (SGLT2i) are emerging as the gold standard for treatment of type 2 diabetes (T2D) with renal protective benefits independent of glucose lowering. We took a high-level approach to evaluate the effects of the SGLT2i, empagliflozin (EMPA) on renal metabolism and function in a prediabetic model of metabolic syndrome. Male and female 12-wk-old TallyHo (TH) mice, and their closest genetic lean strain (Swiss-Webster, SW) were treated with a high-milk-fat diet (HMFD) plus/minus EMPA (@0.01%) for 12-wk. Kidney weights and glomerular filtration rate were slightly increased by EMPA in the TH mice. Glomerular feature analysis by unsupervised clustering revealed sexually dimorphic clustering, and one unique cluster relating to EMPA. Periodic acid Schiff (PAS) positive areas, reflecting basement membranes and mesangium were slightly reduced by EMPA. Phasor-fluorescent life-time imaging (FLIM) of free-to-protein bound NADH in cortex showed a marginally greater reliance on oxidative phosphorylation with EMPA. Overall, net urine sodium, glucose, and albumin were slightly increased by EMPA. In TH, EMPA reduced the sodium phosphate cotransporter, type 2 (NaPi-2), but increased sodium hydrogen exchanger, type 3 (NHE3). These changes were absent or blunted in SW. EMPA led to changes in urine exosomal microRNA profile including, in females, enhanced levels of miRs 27a-3p, 190a-5p, and 196b-5p. Network analysis revealed "cancer pathways" and "FOXO signaling" as the major regulated pathways. Overall, EMPA treatment to prediabetic mice with limited renal disease resulted in modifications in renal metabolism, structure, and transport, which may preclude and underlie protection against kidney disease with developing T2D.NEW & NOTEWORTHY Renal protection afforded by sodium glucose transporter, type 2 inhibitors (SGLT2i), e.g., empagliflozin (EMPA) involves complex intertwined mechanisms. Using a novel mouse model of obesity with insulin resistance, the TallyHo/Jng (TH) mouse on a high-milk-fat diet (HMFD), we found subtle changes in metabolism including altered regulation of sodium transporters that line the renal tubule. New potential epigenetic determinants of metabolic changes relating to FOXO and cancer signaling pathways were elucidated from an altered urine exosomal microRNA signature.

Defining the activity of pro-reparative extracellular vesicles in wound healing based on miRNA payloads and cell type-specific lineage mapping

Small extracellular vesicles (EVs) are released by cells and deliver biologically active payloads to coordinate the response of multiple cell types in cutaneous wound healing. Here we used a cutaneous injury model as a donor of pro-reparative EVs to treat recipient diabetic obese mice, a model of impaired wound healing. We established a functional screen for microRNAs (miRNAs) that increased the pro-reparative activity of EVs and identified a down-regulation of miR-425-5p in EVs in vivo and in vitro associated with the regulation of adiponectin. We tested a cell type-specific reporter of a tetraspanin CD9 fusion with GFP to lineage map the release of EVs from macrophages in the wound bed, based on the expression of miR-425-5p in macrophage-derived EVs and the abundance of macrophages in EV donor sites. Analysis of different promoters demonstrated that EV release under the control of a macrophage-specific promoter was most abundant and that these EVs were internalized by dermal fibroblasts. These findings suggested that pro-reparative EVs deliver miRNAs, such as miR-425-5p, that stimulate the expression of adiponectin that has insulin-sensitizing properties. We propose that EVs promote intercellular signaling between cell layers in the skin to resolve inflammation, induce proliferation of basal keratinocytes, and accelerate wound closure.

The role of inflammasomes in human diseases and their potential as therapeutic targets

Inflammasomes are large protein complexes that play a major role in sensing inflammatory signals and triggering the innate immune response. Each inflammasome complex has three major components: an upstream sensor molecule that is connected to a downstream effector protein such as caspase-1 through the adapter protein ASC. Inflammasome formation typically occurs in response to infectious agents or cellular damage. The active inflammasome then triggers caspase-1 activation, followed by the secretion of pro-inflammatory cytokines and pyroptotic cell death. Aberrant inflammasome activation and activity contribute to the development of diabetes, cancer, and several cardiovascular and neurodegenerative disorders. As a result, recent research has increasingly focused on investigating the mechanisms that regulate inflammasome assembly and activation, as well as the potential of targeting inflammasomes to treat various diseases. Multiple clinical trials are currently underway to evaluate the therapeutic potential of several distinct inflammasome-targeting therapies. Therefore, understanding how different inflammasomes contribute to disease pathology may have significant implications for developing novel therapeutic strategies. In this article, we provide a summary of the biological and pathological roles of inflammasomes in health and disease. We also highlight key evidence that suggests targeting inflammasomes could be a novel strategy for developing new disease-modifying therapies that may be effective in several conditions.

Exploring the therapeutic potential of Sirt6-enriched adipose stem cell-derived exosomes in myocardial ischemia-reperfusion injury: unfolding new epigenetic frontiers

BACKGROUND

The management of myocardial ischemia-reperfusion injury (MIRI) presents continuous therapeutic challenges. NAD-dependent deacetylase Sirtuin 6 (Sirt6) plays distinct roles in various disease contexts and is hence investigated for potential therapeutic applications for MIRI. This study aimed to examine the impact of Sirt6-overexpressing exosomes derived from adipose stem cells (S-ASC-Exo) on MIRI, focusing on their influence on AIM2-pyroptosis and mitophagy processes. The sirtuin family of proteins, particularly Sirtuin 6 (Sirt6), play a pivotal role in these processes. This study aimed to explore the potential therapeutic effects of Sirt6-enriched exosomes derived from adipose stem cells (S-ASC-Exo) on regulating MIRI.

RESULTS

Bioinformatic analysis revealed a significant downregulation of Sirt6 in MIRI subjected to control group, causing a consequential increase in mitophagy and pyroptosis regulator expressions. Therefore, our study revealed that Sirt6-enriched exosomes influenced the progression of MIRI through the regulation of target proteins AIM2 and GSDMD, associated with pyroptosis, and p62 and Beclin-1, related to mitophagy. The introduction of S-ASC-Exo inhibited AIM2-pyroptosis while enhancing mitophagy. Consequently, this led to a significant reduction of GSDMD cleavage and pyroptosis in endothelial cells, catalyzing a deceleration in the progression of atherosclerosis. Extensive in vivo and in vitro assays were performed to validate the expressions of these specific genes and proteins, which affirmed the dynamic modulation by Sirt6-enriched exosomes. Furthermore, treatment with S-ASC-Exo drastically ameliorated cardiac functions and limited infarct size, underlining their cardioprotective attributes.

CONCLUSIONS

Our study underscores the potential therapeutic role of Sirt6-enriched exosomes in managing MIRI. We demonstrated their profound cardioprotective effect, evident in the enhanced cardiac function and attenuated tissue damage, through the strategic modulation of AIM2-pyroptosis and mitophagy. Given the intricate interplay between Sirt6 and the aforementioned processes, a comprehensive understanding of these pathways is essential to fully exploit the therapeutic potential of Sirt6. Altogether, our findings indicate the promise of Sirt6-enriched exosomes as a novel therapeutic strategy in treating ischemia-reperfusion injuries and cardiovascular diseases at large. Future research needs to underscore optimizing the balance of mitophagy during myocardial ischemia to avoid potential loss of normal myocytes.

Advances in the study of exosomes in cardiovascular diseases

BACKGROUND

Cardiovascular disease (CVD) has been the leading cause of death worldwide for many years. In recent years, exosomes have gained extensive attention in the cardiovascular system due to their excellent biocompatibility. Studies have extensively researched miRNAs in exosomes and found that they play critical roles in various physiological and pathological processes in the cardiovascular system. These processes include promoting or inhibiting inflammatory responses, promoting angiogenesis, participating in cell proliferation and migration, and promoting pathological progression such as fibrosis.

AIM OF REVIEW

This systematic review examines the role of exosomes in various cardiovascular diseases such as atherosclerosis, myocardial infarction, ischemia-reperfusion injury, heart failure and cardiomyopathy. It also presents the latest treatment and prevention methods utilizing exosomes. The study aims to provide new insights and approaches for preventing and treating cardiovascular diseases by exploring the relationship between exosomes and these conditions. Furthermore, the review emphasizes the potential clinical use of exosomes as biomarkers for diagnosing cardiovascular diseases.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Exosomes are nanoscale vesicles surrounded by lipid bilayers that are secreted by most cells in the body. They are heterogeneous, varying in size and composition, with a diameter typically ranging from 40 to 160 nm. Exosomes serve as a means of information communication between cells, carrying various biologically active substances, including lipids, proteins, and small RNAs such as miRNAs and lncRNAs. As a result, they participate in both physiological and pathological processes within the body.

Cardiac-to-adipose axis in metabolic homeostasis and diseases: special instructions from the heart

Adipose tissue is essential for maintaining systemic metabolic homeostasis through traditional metabolic regulation, endocrine crosstalk, and extracellular vesicle production. Adipose dysfunction is a risk factor for cardiovascular diseases. The heart is a traditional pump organ. However, it has recently been recognized to coordinate interorgan cross-talk by providing peripheral signals known as cardiokines. These molecules include specific peptides, proteins, microRNAs and novel extracellular vesicle-carried cargoes. Current studies have shown that generalized cardiokine-mediated adipose regulation affects systemic metabolism. Cardiokines regulate lipolysis, adipogenesis, energy expenditure, thermogenesis during cold exposure and adipokine production. Moreover, cardiokines participate in pathological processes such as obesity, diabetes and ischemic heart injury. The underlying mechanisms of the cardiac-to-adipose axis mediated by cardiokines will be further discussed to provide potential therapeutic targets for metabolic diseases and support a new perspective on the need to correct adipose dysfunction after ischemic heart injury.

The beneficial effects of mesenchymal stem cells and their exosomes on myocardial infarction and critical considerations for enhancing their efficacy

Mesenchymal stem cells (MSCs) are multipotent stromal cells with regenerative, anti-inflammatory, and immunomodulatory properties. MSCs and their exosomes significantly improved structural and functional alterations after myocardial infarction (MI) in preclinical studies and clinical trials. By reprograming intracellular signaling pathways, MSCs attenuate inflammatory response, oxidative stress, apoptosis, pyroptosis, and endoplasmic reticulum (ER) stress and improve angiogenesis, mitochondrial biogenesis, and myocardial remodeling after MI. MSC-derived exosomes contain a mixture of non-coding RNAs, growth factors, anti-inflammatory mediators, and anti-fibrotic factors. Although primary results from clinical trials were promising, greater efficacies can be achieved by controlling several modifiable factors. The optimum timing of transplantation, route of administration, origin of MSCs, number of doses, and number of cells per dose need to be further investigated by future studies. Newly, highly effective MSC delivery systems have been developed to improve the efficacy of MSCs and their exosomes. Moreover, MSCs can be more efficacious after being pretreated with non-coding RNAs, growth factors, anti-inflammatory or inflammatory mediators, and hypoxia. Similarly, viral vector-mediated overexpression of particular genes can augment the protective effects of MSCs on MI. Therefore, future clinical trials must consider these advances in preclinical studies to properly reflect the efficacy of MSCs or their exosomes for MI.

Exosomal Non-Coding RNA Mediates Macrophage Polarization: Roles in Cardiovascular Diseases

Extracellular vesicles (EVs) or exosomes are nanosized extracellular particles that contain proteins, DNA, non-coding RNA (ncRNA) and other molecules, which are widely present in biofluids throughout the body. As a key mediator of intercellular communication, EVs transfer their cargoes to target cells and activate signaling transduction. Increasing evidence shows that ncRNA is involved in a variety of pathological and physiological processes through various pathways, particularly the inflammatory response. Macrophage, one of the body's "gatekeepers", plays a crucial role in inflammatory reactions. Generally, macrophages can be classified as pro-inflammatory type (M1) or anti-inflammatory type (M2) upon their phenotypes, a phenomenon termed macrophage polarization. Increasing evidence indicates that the polarization of macrophages plays important roles in the progression of cardiovascular diseases (CVD). However, the role of exosomal ncRNA in regulating macrophage polarization and the role of polarized macrophages as an important source of EV in CVD remains to be elucidated. In this review, we summarize the role and molecular mechanisms of exosomal-ncRNA in regulating macrophage polarization during CVD development, focusing on their cellular origins, functional cargo, and their detailed effects on macrophage polarization. We also discuss the role of polarized macrophages and their derived EV in CVD as well as the therapeutic prospects of exosomal ncRNA in the treatment of CVD.

Extracellular Vesicles in Adipose Tissue Communication with the Healthy and Pathological Heart

Adipose tissue and its diverse cell types constitute one of the largest endocrine organs. With multiple depot locations, adipose tissue plays an important regulatory role through paracrine and endocrine communication, particularly through the secretion of a wide range of bioactive molecules, such as nucleic acids, proteins, lipids or adipocytokines. Over the past several years, research has uncovered a myriad of interorgan communication signals mediated by small lipid-derived nanovesicles known as extracellular vesicles (EVs), in which secreted bioactive molecules are stably transported as cargo molecules and delivered to adjacent cells or remote organs. EVs constitute an essential part of the human adipose secretome, and there is a growing body of evidence showing the crucial implications of adipose-derived EVs in the regulation of heart function and its adaptative capacity. The adipose tissue modifications and dysfunction observed in obesity and aging tremendously affect the adipose-EV secretome, with important consequences for the myocardium. The present review presents a comprehensive analysis of the findings in this novel area of research, reports the key roles played by adipose-derived EVs in interorgan cross-talk with the heart and discusses their implications in physiological and pathological conditions affecting adipose tissue and/or the heart (pressure overload, ischemia, diabetic cardiomyopathy, etc.).

Additional improvement in regional myocardial ischemia after intracardiac injection of bone marrow cells during CABG surgery

Background

Post-procedure residual ischemia is associated with worse prognosis in patients with coronary artery diasease (CAD).

Objective

We evaluated whether autologous bone marrow-derived cells (BMC) contribute to additional reduction in regional stress-induced myocardial ischemia (SIMI) in patients undergoing incomplete coronary artery bypass graft surgery (CABG).

Methods

In a double-blind, randomized, placebo-controlled trial, we enrolled 143 patients (82% men, 58 ± 11 years) with stable CAD and not candidates for complete CABG. They received 100 million BMC (n = 77) or placebo (n = 66) injected into ischemic non-revascularized segments during CABG. The primary outcome was improvement on SIMI quantified as the area at risk in injected segments assessed by cardiovascular magnetic resonance (CMR) 1, 6, and 12 months after CABG.

Results

The reduction in global SIMI after CABG was comparable (p = 0.491) in both groups indicating sustained beneficial effects of the surgical procedure over 12 month period. In contrast, we observed additional improvement in regional SIMI in BMC treated group (p = 0.047). Baseline regional SIMI values were comparable [18.5 (16.2-21.0) vs. 18.5 (16.5-20.7)] and reached the lowest values at 1 month [9.74 (8.25; 11.49) vs. 12.69 (10.84; 14.85)] for BMC and placebo groups, respectively. The ischemia's improvement from baseline represented a 50% difference in regional SIMI in favor of the BMC transplanted group at 30 days. We found no differences in clinical and LVEF% between groups during the 12 month follow-up period. The 1 month rate of major adverse cerebral and cardiovascular events (MACCE) (p = 0.34) and all-cause mortality (p = 0.08) did not differ between groups 1 month post intervention.

Conclusion

We provided evidence that BMC leads to additional reduction in regional SIMI in chronic ischemic patients when injected in segments not subjected to direct surgical revascularization. This adjuvant therapy deserves further assessment in patients with advanced CAD especially in those with microcirculation dysfunction.

Clinical trial registration

https://clinicaltrials.gov/, identifier NCT01727063.

Time-regulated transcripts with the potential to modulate human pluripotent stem cell-derived cardiomyocyte differentiation

Background

Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) are a promising disease model, even though hiPSC-CMs cultured for extended periods display an undifferentiated transcriptional landscape. MiRNA–target gene interactions contribute to fine-tuning the genetic program governing cardiac maturation and may uncover critical pathways to be targeted.

Methods

We analyzed a hiPSC-CM public dataset to identify time-regulated miRNA–target gene interactions based on three logical steps of filtering. We validated this process in silico using 14 human and mouse public datasets, and further confirmed the findings by sampling seven time points over a 30-day protocol with a hiPSC-CM clone developed in our laboratory. We then added miRNA mimics from the top eight miRNAs candidates in three cell clones in two different moments of cardiac specification and maturation to assess their impact on differentiation characteristics including proliferation, sarcomere structure, contractility, and calcium handling.

Results

We uncovered 324 interactions among 29 differentially expressed genes and 51 miRNAs from 20,543 transcripts through 120 days of hiPSC-CM differentiation and selected 16 genes and 25 miRNAs based on the inverse pattern of expression (Pearson R-values < − 0.5) and consistency in different datasets. We validated 16 inverse interactions among eight genes and 12 miRNAs (Person R-values < − 0.5) during hiPSC-CMs differentiation and used miRNAs mimics to verify proliferation, structural and functional features related to maturation. We also demonstrated that miR-124 affects Ca²⁺ handling altering features associated with hiPSC-CMs maturation.

Conclusion

We uncovered time-regulated transcripts influencing pathways affecting cardiac differentiation/maturation axis and showed that the top-scoring miRNAs indeed affect primarily structural features highlighting their role in the hiPSC-CM maturation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-03138-x.