Cardiovascular Risk Factors and Differential Transcriptomic Profile of the Subcutaneous and Visceral Adipose Tissue and Their Resident Stem Cells

Unlocking the Cardiovascular Benefits of Walnuts: Insights on Molecular Mechanism From Animal Studies

The health-promoting benefits of walnut consumption are substantially ascribed to its fatty acid (FA) profile, which is rich in polyunsaturated FA with an exceptionally high n-3 to n-6 ratio. There are also phytonutrients in walnuts that are linked to health welfare. This review article integrates all studies on the effects of walnuts on the cardiovascular system performed on experimental animals, and thus is a source of data on the mechanisms underlying the observed effects. These studies, which are very diverse in experimental design, indicate that a diet enriched with walnuts or treating animals with walnut extract or chemical constituents of walnuts, has many favorable effects on heart and vascular system function. The cardiovascular effect of walnuts depends on the metabolic status of the organism. Among the cardiovascular effects of walnuts is that they improve the FA profile in the circulation and heart in favor of n-3 polyunsaturated FAs. In addition, a favorable effect on triglyceride and cholesterol status, which reduces cardiovascular disease risk, is observed. Intake of walnuts promotes FA catabolism and has anti-inflammatory, antioxidant, and antiarrhythmic effects. Walnuts also have a beneficial effect on vascular tone, accompanied by a decrease in blood pressure and reduced risk for atherosclerosis. In conclusion, studies on experimental animals encourage the consumption of walnuts as a simple, convenient approach to improve cardiovascular health.

Exploring differential miRNA expression profiles in muscular and visceral adipose tissue of patients with severe obesity

BACKGROUND

This study aims to investigate the differential miRNA expression profile between the visceral white adipose tissue and the skeletal muscle of people with obesity undergoing bariatric surgery.

METHODS

Skeletal muscle and visceral adipose tissue samples of 10 controls and 38 people with obesity (50% also with type 2 diabetes) undergoing bariatric surgery were collected. miRNA expression profiles were analyzed using Next-Generation Sequencing and subsequently validated using RT-PCR.

RESULTS

Approximately 69% of miRNAs showed similar expression in both tissues, however, 55 miRNAs were preferentially expressed in visceral adipose tissue and 53 in skeletal muscle. miR-122b-5p was uniquely identified in skeletal muscle, while miR-1-3p and miR-206 were upregulated in skeletal muscle. Conversely, miR-224-5p and miR-335-3p exhibited upregulation in visceral adipose tissue. Notably, distinctions related to the presence of type 2 diabetes were observed solely in the expression of miR-1-3p and miR-206 in visceral adipose tissue.

CONCLUSIONS

This is the first study unveiling distinct miRNA expression profiles in paired samples of visceral adipose tissue and skeletal muscle in humans. The identification of obesity-specific miRNAs in these tissues opens up promising avenues for research into potential biomarkers for obesity diagnosis and treatment.

Microarray Analysis of Visceral Adipose Tissue in Obese Women Reveals Common Crossroads Among Inflammation, Metabolism, Addictive Behaviors, and Cancer: AKT3 and MAPK1 Cross Point in Obesity

Background: Visceral adipose tissue (VAT) abnormalities are directly associated with obesity-associated disorders. The underlying mechanisms that confer increased pathological risk to VAT in obesity have not been fully described. Methods: A case-control study was conducted that included 10 women with obesity (36.80 ± 7.39 years, BMI ≥ 30 kg/m2) and 10 women of normal weight (32.70 ± 9.45 years, BMI < 24.9 kg/m2). RNA was extracted from greater omentum biopsies, and, using a DNA microarray, differential transcriptomic expression of VAT in women with obesity was evaluated taking as a reference that of women with normal weight. The differentially expressed genes (DEGs) were classified into functional biological processes and signaling pathways; moreover, the protein-protein interaction (PPI) networks were integrated for a deeper analysis of the pathways and genes involved in the central obesity-associated disorders. The expression of TNF-α, MAPK, and AKT proteins was also quantified in VAT. Results: The VAT of women with obesity had 3808 DEGs, mainly associated with the cellular process of inflammation and carbohydrates and lipid metabolism. Overexpressed genes were associated with inflammatory, metabolic, hormonal, neuroendocrine, carcinogenic, and infectious pathways. Cellular processes related to addictive behaviors were notable. MAPK and PI3K-AKT pathways were overexpressed, and Mapk1 and Akt3 genes were common crossing points among obesity-associated disorders' pathways. The increased expression of MAPK, AKT, and TNF proteins was confirmed in the VAT of women with obesity. Conclusion: VAT confers a complex and blended pathogenic transcriptomic profile in obese patients, where abnormal processes are mainly controlled by activating intracellular signaling pathways that exhibit a high degree of redundancy. Identifying shared cross points between those pathways could allow specific targeting treatments to exert a widespread effect over multiple pathogenic processes.

Crosstalk of human coronary perivascular adipose-derived stem cells with vascular cells: role of tissue factor

The coronary perivascular adipose tissue (cPVAT) has been associated to the burden of cardiovascular risk factors and to the underlying vessel atherosclerotic plaque severity. Although the "outside to inside" hypothesis of PVAT-derived-adipokine regulation of vessel function is currently accepted, whether the resident mesenchymal stem cells (ASCs) in PVAT have a regulatory role on the underlying vascular arterial smooth muscle cells (VSMCs) is not known. Here, we investigated the interactions between resident PVAT-ASCs and VSMCs. ASCs were obtained from PVAT overlying the left anterior descending (LAD) coronary artery of hearts removed at heart transplant operations. PVAT was obtained both from patients with non-ischemic and ischemic heart disease as the cause of heart transplant. ASCs were isolated from PVAT, phenotypically characterized by flow cytometry, functionally tested for proliferation, and differentiation. Crosstalk between ASCs and VSMCs was investigated by co-culture studies. ASCs were detected in the adventitia of the LAD-PVAT showing differentiation capacity and angiogenic potential. ASCs obtained from PVAT of non-ischemic and ischemic hearts showed different tissue factor (TF) expression levels, different VSMCs recruitment capacity through the axis ERK1/2-ETS1 signaling and different angiogenic potential. Induced upregulation of TF in ASCs isolated from ischemic PVAT rescued their angiogenic capacity in subcutaneously implanted plugs in mice, whereas silencing TF in ASCs decreased the proangiogenic capacity of non-ischemic ASCs. The results indicate for the first time a novel mechanism of regulation of VSMCs by PVAT-ASCs in angiogenesis, mediated by TF expression in ASCs. Regulation of TF in ASCs may become a therapeutic intervention to increase cardiac protection.

Differentiation of Adipose Tissue Mesenchymal Stem Cells into Endothelial Cells Depends on Fat Depot Conditions: Regulation by miRNA

The development of obesity is associated with substantial modulation of adipose tissue (AT) structure. The plasticity of the AT is reflected by its remarkable ability to expand or reduce in size throughout the adult lifespan, which is linked to the development of its vasculature. This increase in AT vasculature could be mediated by the differentiation of adipose tissue-derived stem cells (ASCs) into endothelial cells (ECs) and form new microvasculature. We have already shown that microRNA (miRNA)-145 regulates the differentiation of ASCs into EC-like (ECL) cells. Here, we investigated whether ASCs-differentiation into ECs is governed by a miRNAs signature that depends on fat depot location and /or the metabolic condition produced by obesity. Human ASCs, which were obtained from white AT by surgical procedures from lean and obese patients, were induced to differentiate into ECL cells. We have identified that miRNA-29b-3p in both subcutaneous (s)ASCs and visceral ASCs and miRNA-424-5p and miRNA-378a-3p in subcutaneous (s)ASCs are involved in differentiation into EC-like cells. These miRNAs modulate their pro-angiogenic effects on ASCs by targeting FGFR1, NRP2, MAPK1, and TGF-β2, and the MAPK signaling pathway. We show for the first time that miRNA-29b-3p upregulation contributes to ASCs' differentiation into ECL cells by directly targeting TGFB2 in both sASCs and visceral ASCs. Moreover, our results reveal that, independent of sASCs' origin (obese/lean), the upregulation of miRNA-378a-3p and the downregulation of miRNA-424-5p inhibit MAPK1 and overexpress FGFR1 and NRP2, respectively. In summary, both the adipose depot location and obesity affect the differentiation of resident ASCs through the expression of specific miRNAs.

Adipose Tissue Exosome circ_sxc Mediates the Modulatory of Adiposomes on Brain Aging by Inhibiting Brain dme-miR-87-3p

Aging of the brain usually leads to the decline of neurological processes and is a major risk factor for various neurodegenerative diseases, including sleep disturbances and cognitive decline. Adipose tissue exosomes, as adipocyte-derived vesicles, may mediate the regulatory processes of adipose tissue on other organs, including the brain; however, the regulatory mechanisms remain unclear. We analyzed the sleep-wake behavior of young (10 days) and old (40 days) Drosophila and found that older Drosophila showed increased sleep fragmentation, which is similar to mammalian aging characteristics. To investigate the cross-tissue regulatory mechanisms of adiposity on brain aging, we extracted 10-day and 40-day Drosophila adipose tissue exosomes and identified circRNAs with age-dependent expression differences by RNA-seq and differential analysis. Furthermore, by combining data from 3 datasets of the GEO database (GSE130158, GSE24992, and GSE184559), circ_sxc that was significantly downregulated with age was finally screened out. Moreover, dme-miR-87-3p, a conserved target of circ_sxc, accumulates in the brain with age and exhibits inhibitory effects in predicted binding relationships with neuroreceptor ligand genes. In summary, the current study showed that the Drosophila brain could obtain circ_sxc by uptake of adipose tissue exosomes which crossed the blood-brain barrier. And circ_sxc suppressed brain miR-87-3p expression through sponge adsorption, which in turn regulated the expression of neurological receptor ligand proteins (5-HT1B, GABA-B-R1, Rdl, Rh7, qvr, NaCP60E) and ensured brain neuronal synaptic signaling normal function of synaptic signaling. However, with aging, this regulatory mechanism is dysregulated by the downregulation of the adipose exosome circ_sxc, which contributes to the brain exhibiting sleep disturbances and other "aging" features.

Role of obesity in pathogenesis of acute pancreatitis

Acute pancreatitis (AP) is one of the most common digestive disorders that cause hospitalization. While most of patients with AP have a mild to moderate disease and recover rapidly, about 20% of patients with AP have a severe disease and experience substantial morbidity and mortality from local and/or systemic compli-cations. The incidence of obesity has increased worldwide, and its epidemiological characteristics and rising trend are consistent with those of AP. Therefore, obesity has probably contributed to the increase in the incidence and severity of AP. However, previous studies have generated conflicting results, and some studies demonstrated that obesity is a protective factor in patients with AP. Here we discuss the role of obesity in the pathogenesis of AP and the underlying mechanisms based on clinically relevant studies.

Adipose-Derived Stem Cells to Treat Ischemic Diseases: The Case of Peripheral Artery Disease

Critical limb ischemia incidence and prevalence have increased over the years. However, there are no successful treatments to improve quality of life and to reduce the risk of cardiovascular and limb events in these patients. Advanced regenerative therapies have focused their interest on the generation of new blood vessels to repair tissue damage through the use of stem cells. One of the most promising sources of stem cells with high potential in cell-based therapy is adipose-derived stem cells (ASCs). ASCs are adult mesenchymal stem cells that are relatively abundant and ubiquitous and are characterized by a multilineage capacity and low immunogenicity. The proangiogenic benefits of ASCs may be ascribed to: (a) paracrine secretion of proangiogenic molecules that may stimulate angiogenesis; (b) secretion of microvesicles/exosomes that are also considered as a novel therapeutic prospect for treating ischemic diseases; and (c) their differentiation capability toward endothelial cells (ECs). Although we know the proangiogenic effects of ASCs, the therapeutic efficacy of ASCs after transplantation in peripheral artery diseases patients is still relatively low. In this review, we evidence the potential therapeutic use of ASCs in ischemic regenerative medicine. We also highlight the main challenges in the differentiation of these cells into functional ECs. However, significant efforts are still needed to ascertain relevant transcription factors, intracellular signaling and interlinking pathways in endothelial differentiation.

Predictive importance of the visceral adiposity index and atherogenic index of plasma of all-cause and cardiovascular disease mortality in middle-aged and elderly Lithuanian population

Background

Two indices: visceral adiposity index (VAI) and atherogenic index of plasma (AIP) during several recent years were implemented into epidemiological studies for predicting of cardiovascular diseases (CVD) and mortality risk. Our study aimed to evaluate the association of VAI and AIP with the risk of all-cause and CVD mortality among the Lithuanian urban population aged 45–72 years.

Methods

In the baseline survey (2006–2008), 7,115 men and women 45–72 years of age were examined within the framework of the international study Health, Alcohol and Psychosocial Factors in Eastern Europe (HAPIEE). Six thousand six hundred and seventy-one participants (3,663 women and 3,008 men) were available for statistical analysis (after excluding 429 respondents with the missed information on study variables) and for them, VAI and AIP were calculated. The questionnaire evaluated lifestyle behaviors, including smoking and physical activity. All participants in the baseline survey were followed up for all-cause and CVD mortality events until December 31st, 2020. Multivariable Cox regression models were applied for statistical data analysis.

Results

After accounting for several potential confounders, higher levels of VAI (compared 5th quintile to 1st quintile) were associated with significantly higher CVD mortality in men [Hazards ratio (HR) = 1.38] and all-cause mortality in women (HR = 1.54) after 10-year follow-up. CVD mortality significantly increased in men with 0 the highest AIP quintile compared with that for the lowest quintile (HR = 1.40). In women, all-cause mortality was significantly higher for the 4th quintile of AIP as compared with the 1st quintile (HR = 1.36).

Conclusions

High-risk VAI levels were statistically significantly associated with all-cause mortality risk in men and women groups. The higher AIP level (5th quintile vs. 1st quintile—in men and 4th quintile vs. 1st quintile—in women) was significantly associated with increased mortality from CVD in the men group and increased all-cause mortality in the women group.

The Effects of Shear Force-Based Processing of Lipoaspirates on White Adipose Tissue and the Differentiation Potential of Adipose Derived Stem Cells

Autologous lipotransfer is a promising method for tissue regeneration, because white adipose tissue contains a heterogeneous cell population, including mesenchymal stem cells, endothelial cells, immune cells, and adipocytes. In order to improve the outcome, adipose tissue can be processed before application. In this study, we investigated changes caused by mechanical processing. Lipoaspirates were processed using sedimentation, first-time centrifugation, shear-force homogenization, and second-time centrifugation. The average adipocyte size, stromal vascular cell count, and adipocyte depot size were examined histologically at every processing step. In addition, the adipose derived stem cells (ADSCs) were isolated and differentiated osteogenically and adipogenically. While homogenization causes a disruption of adipocyte depots, the shape of the remaining adipocytes is not changed. On average, these adipocytes are smaller than the depot adipocytes, they are surrounded by the ECM, and therefore mechanically more stable. The volume loss of adipocyte depots leads to a significant enrichment of stromal vascular cells such as ADSCs. However, the mechanical processing does not change the potential of the ADSCs to differentiate adipogenically or osteogenically. It thus appears that mechanically processed lipoaspirates are promising for the reparation of even mechanically stressed tissue as that found in nasolabial folds. The changes resulting from the processing correspond more to a filtration of mechanically less stable components than to a manipulation of the tissue.

Visceral adiposity index and atherogenic index of plasma as useful predictors of risk of cardiovascular diseases: evidence from a cohort study in Iran

Background

Visceral adiposity index (VAI) and atherogenic index of plasma (AIP) are relatively new indicators for predicting non-communicable diseases (NCDs). Therefore, the present study was done to assess the association of AIP and VAI with risk of cardiovascular diseases (CVDs).

Methods

This cross-sectional study was conducted on 7,362 individuals aged between 35 and 65 years old participated in Ravansar non-communicable diseases (RaNCD) cohort study. AIP was calculated based on levels of triglyceride and high -density lipoprotein cholesterol (HDL-C). VAI was calculated using values of body mass index (BMI), waist circumference (WC), triglyceride, and HDL-C. Logistic regression models were used to assess the association of AIP and VAI with risk of CVDs.

Results

Mean values of anthropometric indices, lipid profile, AIP, and VAI were significantly higher in patients with CVDs than individuals without CVDs (P < 0.001). Mean values of anthropometric indices, lipid profile, and NCDs including hypertension, dyslipidemia, diabetes, metabolic syndrome (MetS), and CVDs in the third tertile of AIP and VAI were significantly increased compared to the first tertile (P < 0.001). After adjusting confounding factors, risk of CVDs in the third tertile of AIP was (OR = 1.32, 95 % CI: 1.03, 1.69) significantly increased compared to the first tertile. Risk of CVDs in the third tertile of VAI was (OR = 1.48, 95 % CI: 1.12, 1.97) significantly increased compared to the first tertile.

Conclusions

According to the findings, AIP and VAI were positively associated with risk of CVDs. Therefore, AIP and VAI can be useful in identifying high-risk subgroups of CVDs in general population.

Impact of Diabetes Mellitus on the Potential of Autologous Stem Cells and Stem Cell-Derived Microvesicles to Repair the Ischemic Heart

Ischemic heart disease remains the leading cause of morbidity and mortality worldwide. Despite the advances in medical management and catheter-based therapy, mortality remains high, as does the risk of developing heart failure. Regenerative therapies have been widely used as an alternative option to repair the damaged heart mainly because of their paracrine-related beneficial effects. Although cell-based therapy has been demonstrated as feasible and safe, randomized controlled trials and meta-analyses show little consistent benefit from treatments with adult-derived stem cells. Mounting evidence from our group and others supports that cardiovascular risk factors and comorbidities impair stem cell potential thus hampering their autologous use. This review aims to better understand the influence of diabetes on stem cell potential. For this purpose, we will first discuss the most recent advances in the mechanistic understanding of the effects of diabetes on stem cell phenotype, function, and molecular fingerprint to further elaborate on diabetes-induced alterations in stem cell extracellular vesicle profile. Although we acknowledge that multiple sources of stem or progenitor cells are used for regenerative purposes, we will focus on bone marrow hematopoietic stem/progenitor cells, mesenchymal stem cells residing in the bone marrow, and adipose tissue and briefly discuss endothelial colony-forming cells.