MiR-125b regulates SFRP5 expression to promote growth and activation of cardiac fibroblasts

Circular PVT1 promotes cardiac fibroblast activation interacting with miR-30a-5p and miR-125b-5p

Circular RNAs (circRNAs) are involved in the pathogenesis of several cardiovascular diseases, including heart failure. In this study, we report that circular PVT1 (circPVT1) was upregulated in the left ventricle of 31 ischemic heart failure patients compared to 11 non-ischemic controls. RNA sequencing analysis following circPVT1 knockdown in immortalized human cardiomyocytes identified differentially expressed genes, mainly involved in fibrosis. Notably, in human cardiac fibroblasts, circPVT1 expression significantly increased after TGF-β1 treatment and circPVT1 silencing attenuated the levels of pro-fibrotic markers induced by TGF-β1. RNA pull-down assays validated the interaction between circPVT1 and two fibrosis-related miRNAs, miR-30a-5p and miR-125b-5p. The levels of these miRNAs were not altered upon circPVT1 knockdown. However, the expression of their mRNA targets was deregulated upon circPVT1 silencing, suggesting that circPVT1 modulates miRNA cellular bioavailability. Accordingly, inhibition of either miR-30a-5p or miR-125b-5p restored the expression of TGF-β1-induced pro-fibrotic markers following circPVT1 silencing, indicating that both miR-30a-5p and miR-125b-5p act as downstream effectors of circPVT1 in cardiac fibroblast activation. In conclusion, these findings highlight a pro-fibrotic role for circPVT1, which can regulate cardiac fibroblast activation interacting with the anti-fibrotic miR-30a-5p and miR-125b-5p. The modulation of circPVT1 expression may represent a potential strategy to reduce cardiac fibrosis and remodeling.

Extracellular vesicles in heart failure

Physiologically, extracellular vesicles (EVs) have been implicated as crucial mediators of immune response, cell homeostasis, angiogenesis, cell differentiation and growth, and tissue repair. In heart failure (HF) they may act as regulators of cardiac remodeling, microvascular inflammation, micro environmental changes, tissue fibrosis, atherosclerosis, neovascularization of plaques, endothelial dysfunction, thrombosis, and reciprocal heart-remote organ interaction. The chapter summaries the nomenclature, isolation, detection of EVs, their biologic role and function physiologically as well as in the pathogenesis of HF. Current challenges to the utilization of EVs as diagnostic and predictive biomarkers in HF are also discussed.

Epigenetic signatures in cardiac fibrosis: Focusing on noncoding RNA regulators as the gatekeepers of cardiac fibroblast identity

Cardiac fibroblasts play a pivotal role in cardiac fibrosis by transformation of fibroblasts into myofibroblasts, which synthesis and secrete a large number of extracellular matrix proteins. Ultimately, this will lead to cardiac wall stiffness and impaired cardiac performance. The epigenetic regulation and fate reprogramming of cardiac fibroblasts has been advanced considerably in recent decades. Non coding RNAs (microRNAs, lncRNAs, circRNAs) regulate the functions and behaviors of cardiac fibroblasts, including proliferation, migration, phenotypic transformation, inflammation, pyroptosis, apoptosis, autophagy, which can provide the basis for novel targeted therapeutic treatments that abrogate activation and inflammation of cardiac fibroblasts, induce different death pathways in cardiac fibroblasts, or make it sensitive to established pathogenic cells targeted cytotoxic agents and biotherapy. This review summarizes our current knowledge in this field of ncRNAs function in epigenetic regulation and fate determination of cardiac fibroblasts as well as the details of signaling pathways contribute to cardiac fibrosis. Moreover, we will comment on the emerging landscape of lncRNAs and circRNAs function in regulating signal transduction pathways, gene translation processes and post-translational regulation of gene expression in cardiac fibroblast. In the end, the prospect of cardiac fibroblasts targeted therapy for cardiac fibrosis based on ncRNAs is discussed.

Noncoding RNAs: Master Regulator of Fibroblast to Myofibroblast Transition in Fibrosis

Myofibroblasts escape apoptosis and proliferate abnormally under pathological conditions, especially fibrosis; they synthesize and secrete a large amount of extracellular matrix (ECM), such as α-SMA and collagen, which leads to the distortion of organ parenchyma structure, an imbalance in collagen deposition and degradation, and the replacement of parenchymal cells by fibrous connective tissues. Fibroblast to myofibroblast transition (FMT) is considered to be the main source of myofibroblasts. Therefore, it is crucial to explore the influencing factors regulating the process of FMT for the prevention, treatment, and diagnosis of FMT-related diseases. In recent years, non-coding RNAs, including microRNA, long non-coding RNAs, and circular RNAs, have attracted extensive attention from scientists due to their powerful regulatory functions, and they have been found to play a vital role in regulating FMT. In this review, we summarized ncRNAs which regulate FMT during fibrosis and found that they mainly regulated signaling pathways, including TGF-β/Smad, MAPK/P38/ERK/JNK, PI3K/AKT, and WNT/β-catenin. Furthermore, the expression of downstream transcription factors can be promoted or inhibited, indicating that ncRNAs have the potential to be a new therapeutic target for FMT-related diseases.

Young fibroblast-derived exosomal microRNA-125b transfers beneficial effects on aged cutaneous wound healing

Aged skin wounds heal poorly, resulting in medical, economic, and social burdens posed by nonhealing wounds. Age-related defects in repair are associated with reduced myofibroblasts and dysfunctional extracellular matrix (ECM) deposition. Bidirectional cell-cell communication involving exosome-borne cargo such as micro RNAs (miRs) has emerged as a critical mechanism for wound healing and aged tissue regeneration. Here we report that at the wound edge, aged fibroblasts display reduced migration and differentiation into myofibroblasts, with impaired ECM deposition, when compared with young tissue. Proper activation of fibroblasts to myofibroblasts may alleviate age-related defects in wound healing. Herein, an exosome-guided cell technique was performed to induce effective wound healing. Supplementing wounds with exosomes isolated from young mouse wound-edge fibroblasts (exosomes^Young) significantly improved the abundance of myofibroblasts and wound healing in aged mice and caused fibroblasts to migrate and transition to myofibroblasts in vitro. To determine the underlying mechanism, we found that exosomal transfer of miR-125b to fibroblasts inhibited sirtuin 7 (Sirt7), thus accelerating myofibroblast differentiation and wound healing in aged mice. Notably, after epidermal inhibition of miR-125b or overexpression of Sirt7 in fibroblasts, migration and myofibroblast transition were perturbed. Our findings thus reveal that miR-125b is transferred through exosomes from young fibroblasts to old fibroblasts contributes to promoting fibroblast migration and transition to counteract aging, suggesting a potential avenue for anti-aging interventions in wound healing.

Circulating miR-499a and miR-125b as Potential Predictors of Left Ventricular Ejection Fraction Improvement after Cardiac Resynchronization Therapy

Cardiac resynchronization therapy represents a therapeutic option for heart failure drug-refractory patients. However, due to the lack of success in 30% of the cases, there is a demand for an in-depth analysis of individual heterogeneity. In this study, we aimed to evaluate the prognostic value of circulating miRNA differences. Responder patients were defined by a composite endpoint of the presence of left ventricular reverse remodelling (a reduction ≥15% in telesystolic volume and an increment ≥10% in left ventricular ejection fraction). Circulating miRNAs signature was analysed at the time of the procedure and at a 6-month follow-up. An expression analysis showed, both at baseline and at follow-up, differences between responders and non-responders. Responders presented lower baseline expressions of miR-499, and at follow-up, downregulation of miR-125b-5p, both associated with a significant improvement in left ventricular ejection fraction. The miRNA profile differences showed a marked sensitivity to distinguish between responders and non-responders. Our data suggest that miRNA differences might contribute to prognostic stratification of patients undergoing cardiac resynchronization therapy and suggest that preimplant cardiac context as well as remodelling response are key to therapeutic success.

MiR-125 Family in Cardiovascular and Cerebrovascular Diseases

Cardiovascular and cerebrovascular diseases are a serious threaten to the health of modern people. Understanding the mechanism of occurrence and development of cardiovascular and cerebrovascular diseases, as well as reasonable prevention and treatment of them, is a huge challenge that we are currently facing. The miR-125 family consists of hsa-miR-125a, hsa-miR-125b-1 and hsa-miR-125b-2. It is a kind of miRNA family that is highly conserved among different species. A large amount of literature shows that the lack of miR-125 can cause abnormal development of the cardiovascular system in the embryonic period. At the same time, the miR-125 family participates in the occurrence and development of a variety of cardiovascular and cerebrovascular diseases, including myocardial ischemia, atherosclerosis, ischemia-reperfusion injury, ischemic stroke, and heart failure directly or indirectly. In this article, we summarized the role of the miR-125 family in the development and maturation of cardiovascular system, the occurrence and development of cardiovascular and cerebrovascular diseases, and its important value in the current fiery stem cell therapy. In addition, we presented this in the form of table and diagrams. We also discussed the difficulties and challenges faced by the miR-125 family in clinical applications.

The Role of Anti-Inflammatory Adipokines in Cardiometabolic Disorders: Moving beyond Adiponectin

The global burden of obesity has multiplied owing to its rapidly growing prevalence and obesity-related morbidity and mortality. In addition to the classic role of depositing extra energy, adipose tissue actively interferes with the metabolic balance by means of secreting bioactive compounds called adipokines. While most adipokines give rise to inflammatory conditions, the others with anti-inflammatory properties have been the novel focus of attention for the amelioration of cardiometabolic complications. This review compiles the current evidence on the roles of anti-inflammatory adipokines, namely, adiponectin, vaspin, the C1q/TNF-related protein (CTRP) family, secreted frizzled-related protein 5 (SFRP5), and omentin-1 on cardiometabolic health. Further investigations on the mechanism of action and prospective human trials may pave the way to their clinical application as innovative biomarkers and therapeutic targets for cardiovascular and metabolic disorders.

Secreted Frizzled-Related Protein 5 Protects Against Cardiac Rupture and Improves Cardiac Function Through Inhibiting Mitochondrial Dysfunction

Background: Secreted frizzled-related protein 5 (Sfrp5) has been suggested to be a protective regulatory protein in coronary heart disease. However, the role of Sfrp5 in regulating ischemic injury and its consequences is not known. The aim of our study was to explore the effects of Sfrp5 on hearts after myocardial infarction (MI) and to investigate the underlying mechanisms.

Methods and Results: We found that Sfrp5 was downregulated over time in the heart tissue of MI mice. To further elucidate the role of Sfrp5 during MI, we established a cardiac overexpression of an Sfrp5 mouse model using the cardiotropic adeno-associated virus serotype 9 (AAV9). Overexpression of Sfrp5 significantly reduced infarct size as demonstrated by a decrease in mortality owing to cardiac rupture. Moreover, cardiac overexpression of Sfrp5 increased left ventricular function and mitochondrial biogenesis, decreased cardiomyocyte apoptosis, suppressed inflammation reaction, inhibited oxidative stress, and ameliorated cardiac remodeling as demonstrated by left ventricular ejection fraction, mitochondrial morphology, heart weight, NADH oxidase activity levels, and myocardial fibrosis at 2 weeks post-MI. At the molecular level, overexpression of Sfrp5 significantly increased the expression of p-AMPK^Thr172 protein with higher expression of mitochondrial fusion protein (MFN1 and MFN2) and lower expression of mitochondrial fission protein (p-Drp1^Ser616/Mid49/MFF/Fis-1). In isolated neonatal rat cardiac myocytes, Sfrp5 treatment attenuated hypoxia-induced mitochondrial dysfunction. Inhibition of AMPK activity with compound C abrogated this benefit.

Conclusions: Sfrp5 overexpression inhibits ischemic injury, reduces risk of cardiac rupture, ameliorates post-MI remodeling, and decreases the progression to heart failure via disrupting mitochondrial dysfunction and partly through normalizing the AMPK activity.

MicroRNAs-The Heart of Post-Myocardial Infarction Remodeling

Myocardial infarction (MI) is one of the most frequent cardiac emergencies, with significant potential for mortality. One of the major challenges of the post-MI healing response is that replacement fibrosis could lead to left ventricular remodeling (LVR) and heart failure (HF). This process involves canonical and non-canonical transforming growth factor-beta (TGF-β) signaling pathways translating into an intricate activation of cardiac fibroblasts and disproportionate collagen synthesis. Accumulating evidence has indicated that microRNAs (miRNAs) significantly contribute to the modulation of these signaling pathways. This review summarizes the recent updates regarding the molecular mechanisms underlying the role of the over 30 miRNAs involved in post-MI LVR. In addition, we compare the contradictory roles of several multifunctional miRNAs and highlight their potential use in pressure overload and ischemia-induced fibrosis. Finally, we discuss their attractive role as prognostic biomarkers for HF, highlighting the most relevant human trials involving these miRNAs.

MiR-125b inhibits cardiomyocyte apoptosis by targeting BAK1 in heart failure

Background

Although miR-125b plays a crucial role in many human cancers. However, its function in heart failure (HF) remains unclear. Our study aimed to investigate its involvement in heart failure.

Methods

In this study, the mouse HF model was successfully constructed through transverse aortic constriction (TAC) operation. Changes in mRNA and protein levels in isolated myocytes and heart tissues were examined using qRT-PCR, Western blot and Immunohistochemical staining and immunofluorescent staining. Changes in cardiac functions were examined using ultrasound. Interactions between miR-125b and BAK1 was analyzed using the luciferase reporter assay. Cardiomyocyte apoptosis was evaluated using the TUNEL staining.

Results

We found that miR-125b expression was significantly downregulated in myocardial tissues of HF mice. Moreover, miR-125b upregulation in HF mice injected with agomir-125b efficiently ameliorated cardiac function. Further, miR-125b upregulation significantly decreased the protein levels of apoptosis-related makers c-caspase 3 and Bax, while increased Bcl-2 expression. In addition, BAK1 was identified as a direct target of miR-125b. As expected, BAK1 overexpression observably reversed the effect of agomir-125b on cardiac function and on the expression of apoptosis-related makers in the heart tissues of HF mice.

Conclusions

Taken together, miR-125b overexpression efficiently attenuated cardiac function injury of HF mice by targeting BAK1 through inhibiting cardiomyocyte apoptosis, suggesting that miR-125b/BAK1 axis might be a potential target for the diagnosis or treatment of HF.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-021-00328-w.

Circle the Cardiac Remodeling With circRNAs

Cardiac remodeling occurs after the heart is exposed to stress, which is manifested by pathological processes such as cardiomyocyte hypertrophy and apoptosis, dendritic cells activation and cytokine secretion, proliferation and activation of fibroblasts, and finally leads to heart failure. Circular RNAs (circRNAs) are recently recognized as a specific type of non-coding RNAs that are expressed in different species, in different stages of development, and in different pathological conditions. Growing evidences have implicated that circRNAs play important regulatory roles in the pathogenesis of a variety of cardiovascular diseases. In this review, we summarize the biological origin, characteristics, functional classification of circRNAs and their regulatory functions in cardiomyocytes, endothelial cells, fibroblasts, immune cells, and exosomes in the pathogenesis of cardiac remodeling.

RETRACTED: Mouse bone marrow derived mesenchymal stem cells-secreted exosomal microRNA-125b-5p suppresses atherosclerotic plaque formation via inhibiting Map4k4

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Concern was raised about the reliability of the Western blot results in Figs. 2D and 4E, which appear to have the same eyebrow shaped phenotype as many other publications tabulated here (https://docs.google.com/spreadsheets/d/149EjFXVxpwkBXYJOnOHb6RhAqT4a2llhj9LM60MBffM/edit#gid=0). The journal requested the corresponding author comment on these concerns and provide the raw data. However the authors were not able to satisfactorily fulfil this request and therefore the Editor-in-Chief decided to retract the article.

Exosomes derived from mmu_circ_0000623-modified ADSCs prevent liver fibrosis via activating autophagy

Prolonged parenchymal cell death leads to activation of fibrogenic cells, extracellular matrix accumulation, and eventually liver fibrosis. Increasing evidence shows that exosomes (Exos) secreted by adipose-derived mesenchymal stem cells (ADSCs) can be used to deliver circular RNAs (circRNAs) to treat liver fibrosis. To explore the uses of circRNA, circRNA expression profiles of hepatic tissue from normal and CCl4-induced mice were analyzed using high-throughput circRNA microarrays. The result showed that mmu_circ_0000623 expression was downregulated in CCl4-induced mice. Bioinformatics analysis and luciferin reporter experiments showed that mmu_circ_0000623 interacted with and regulated miR-125/ATG4D. In vitro and in vivo experiments showed that Exos from ADSCs, especially from mmu_circ_0000623-modified ADSCs, significantly suppressed CCl4-induced liver fibrosis by promoting autophagy activation. Autophagy inhibitor treatment significantly reversed the treatment effects of Exos. Proteins involved in autophagy and autophagy plaques positive for ATG4D expression were regulated by mmu_circ_0000623/miR-125. Our study found that Exos derived from mmu_circ_0000623-modified ADSCs prevented liver fibrosis via activating autophagy.

Sfrp5/Wnt5a and leptin/adiponectin levels in the serum and the periarterial adipose tissue of patients with peripheral arterial occlusive disease

BACKGROUND

Leptin, adiponectin, secreted frizzled-related protein 5 (Sfrp5) and wingless-type family member 5a (Wnt5a) are novel adipokines that are involved in insulin sensitivity and atherosclerosis. The aim of the present study was to investigate the serum and periarterial adipose tissue leptin/adiponectin and Sfrp5/Wnt5a levels in patients with peripheral arterial occlusive disease (PAOD).

METHODS

A total of 75 patients with PAOD and 39 control subjects were recruited. The serum concentrations of leptin, adiponectin, Sfrp5 and Wnt5a were measured by ELISAs, and the leptin, adiponectin, Sfrp5 and Wnt5a levels in the periarterial adipose tissue were observed by western blotting.

RESULTS

The serum Sfrp5 levels were significantly lower in the patients with PAOD than in the control subjects (p < 0.001) and Wnt5a levels were higher in the patients with PAOD (p < 0.001). The serum leptin levels were significantly higher in the patients with PAOD than in the control subjects (p < 0.001), and adiponectin levels were significantly lower in the patients with PAOD (p < 0.001). The serum Sfrp5 levels were associated with ABI (rs = 0.274; p = 0.018), Wnt5a (rs = -0.409; p < 0.001), adiponectin (rs = 0.244; p = 0.035) and Leptin/Adiponetin ratio (rs = -0.244; p = 0.037). The adiponectin and Sfrp5 protein levels were decreased in the periarterial adipose tissue of patients with PAOD compared with control subjects. The leptin and Wnt5a protein levels were increased in the periarterial adipose tissue of patients with PAOD compared with control subjects.

CONCLUSION

We demonstrated that the adiponectin and Sfrp5 levels in the serum and periarterial adipose tissue were significantly lower in the patients with PAOD than in the control subjects. The leptin and Wnt5a levels in the serum and periarterial adipose tissue were significantly higher in the patients with PAOD than in the control subjects.

Prognostic Value of Secreted Frizzled-Related Protein 5 in Heart Failure Patients With and Without Type 2 Diabetes Mellitus

BACKGROUND

Patients with heart failure (HF) with diabetes mellitus have distinct biomarker profiles compared with those without diabetes mellitus. SFRP5 (secreted frizzled-related protein 5) is an anti-inflammatory adipokine with an important suppressing role on the development of type 2 diabetes mellitus (T2DM). This study aimed to evaluate the prognostic value of SFRP5 in patients with HF with and without T2DM.

METHODS

The study included 833 consecutive patients with HF, 312 (37.5%) of whom had T2DM. Blood samples were collected at presentation, and SFRP5 levels were measured. The primary outcome was the composite end points of first occurrence of HF rehospitalization or all-cause mortality during follow-up.

RESULTS

During median follow-up of 2.1 years, 335 (40.2%) patients in the cohort experienced the composite primary outcome. After adjustment for multiple risk factors, each doubling of SFRP5 level was associated with a 21% decreased risk of primary outcomes in the overall study population (P<0.001). Subgroup analyses showed that the association between level of SFPR5 and primary outcomes may be stronger in patients with T2DM (hazard ratio, 0.69 [95% CI, 0.61-0.79]) than in patients without T2DM (hazard ratio, 0.89 [95% CI, 0.79-1.01]; interaction P=0.006). Similar associations were observed when taking SFRP5 as a categorical variable. Addition of SFRP5 significantly improved discrimination and reclassification of the incident primary outcomes beyond clinical risk factors and N-terminal pro-B-type natriuretic peptide in all patients with HF and those with T2DM (all P<0.01).

CONCLUSIONS

SFRP5 is an independent novel biomarker for risk stratification in HF, especially in HF with T2DM.

Wnt signaling pathway in aging-related tissue fibrosis and therapies

Fibrosis is the final hallmark of pathological remodeling, which is a major contributor to the pathogenesis of various chronic diseases and aging-related organ failure to fully control chronic wound-healing and restoring tissue function. The process of fibrosis is involved in the pathogenesis of the kidney, lung, liver, heart and other tissue disorders. Wnt is a highly conserved signaling in the aberrant wound repair and fibrogenesis, and sustained Wnt activation is correlated with the pathogenesis of fibrosis. In particular, mounting evidence has revealed that Wnt signaling played important roles in cell fate determination, proliferation and cell polarity establishment. The expression and distribution of Wnt signaling in different tissues vary with age, and these changes have key effects on maintaining tissue homeostasis. In this review, we first describe the major constituents of the Wnt signaling and their regulation functions. Subsequently, we summarize the dysregulation of Wnt signaling in aging-related fibrotic tissues such as kidney, liver, lung and cardiac fibrosis, followed by a detailed discussion of its involvement in organ fibrosis. In addition, the crosstalk between Wnt signaling and other pathways has the potential to profoundly add to the complexity of organ fibrosis. Increasing studies have demonstrated that a number of Wnt inhibitors had the potential role against tissue fibrosis, specifically in kidney fibrosis and the implications of Wnt signaling in aging-related diseases. Therefore, targeting Wnt signaling might be a novel and promising therapeutic strategy against aging-related tissue fibrosis.

Hypercholesterolemia Interferes with Induction of miR-125b-1-3p in Preconditioned Hearts

Ischemic preconditioning (IPre) reduces ischemia/reperfusion (I/R) injury in the heart. The non-coding microRNA miR-125b-1-3p has been demonstrated to play a role in the mechanism of IPre. Hypercholesterolemia is known to attenuate the cardioprotective effect of preconditioning; nevertheless, the exact underlying mechanisms are not clear. Here we investigated, whether hypercholesterolemia influences the induction of miR-125b-1-3p by IPre. Male Wistar rats were fed with a rodent chow supplemented with 2% cholesterol and 0.25% sodium-cholate hydrate for 8 weeks to induce high blood cholesterol levels. The hearts of normo- and hypercholesterolemic animals were then isolated and perfused according to Langendorff, and were subjected to 35 min global ischemia and 120 min reperfusion with or without IPre (3 × 5 min I/R cycles applied before index ischemia). IPre significantly reduced infarct size in the hearts of normocholesterolemic rats; however, IPre was ineffective in the hearts of hypercholesterolemic animals. Similarly, miR-125b-1-3p was upregulated by IPre in hearts of normocholesterolemic rats, while in the hearts of hypercholesterolemic animals IPre failed to increase miR-125b-1-3p significantly. Phosphorylation of cardiac Akt, ERK, and STAT3 was not significantly different in any of the groups at the end of reperfusion. Based on these results we propose here that hypercholesterolemia attenuates the upregulation of miR-125b-1-3p by IPre, which seems to be associated with the loss of cardioprotection.

Expression of Sfrp5/Wnt5a in human epicardial adipose tissue and their relationship with coronary artery disease

Secreted frizzled-related protein 5 (Sfrp5) primarily acts in combination with wingless-type family member 5a (Wnt5a), to inhibits chronic inflammation and repress atherosclerosis and other metabolic disorders. Epicardial adipose tissue (EAT), surrounding the heart and coronary arteries, has been found to be highly related to the progression of coronary artery disease through adipokines production. However, little is known about EAT-derived Sfrp5 and Wnt5a in humans. We aimed to investigate whether the EAT-derived Sfrp5/Wnt5a levels are altered in patients with CAD. Fifty-eight patients with CAD and 29 patients without CAD who underwent cardiac surgery were enrolled. Serum samples and paired adipose biopsies from EAT and subcutaneous adipose tissue (SAT) were collected, and Sfrp5 and Wnt5a levels were detected. Correlation and multivariate regression analyses were performed to determine the relationship between Sfrp5/Wnt5a expression and CAD and other clinical risk factors. According to the results, the CAD group had lower Sfrp5 and higher Wnt5a levels in EAT and serum (all p < 0.05). Serum Sfrp5 levels were significantly lower in CAD patients with impaired myocardial function. EAT Sfrp5 mRNA levels and serum Sfrp5 levels were both negatively associated with the presence of CAD, after adjustment for known biomarkers, EAT mRNA and serum Wnt5a levels correlated positively with the presence of CAD. Thus, we concluded that low Sfrp5 and high Wnt5a levels are associated with the presence of CAD, independent of other conventional risk factors.

High Serum Secreted Frizzled-Related Protein 5 Levels Associates with Early Improvement of Cardiac Function Following ST-Segment Elevation Myocardial Infarction Treated by Primary Percutaneous Coronary Intervention

AIM

Several members of secreted frizzled-related protein (SFRP) are involved in the process of myocardial ischemia-reperfusion injury. However, little is known about the role of SFRP5 in patients with acute ST-segment elevation myocardial infarction (STEMI).

METHODS

In this cross-sectional study, 85 patients with first-time anterior STEMI who underwent timely primary percutaneous coronary intervention (PCI) and 35 patients without coronary artery disease (CAD) were enrolled. Serum SFRP5 levels were measured using an enzyme-linked immunosorbent assay kit. Patients with STEMI were divided into low-SFRP5 and high-SFRP5 groups according to their median baseline serum SFRP5 levels. To evaluate cardiac function and structure after infarction, the left ventricular ejection fraction (LVEF) and left ventricular end-diastolic volume (LVEDV) were measured using echocardiography. The associations between changes in LVEF and reduced LVEF (≤ 50%) and clinical variables were determined by univariate and multivariate analyses.

RESULTS

Baseline serum SFRP5 levels were significantly higher in patients with STEMI than in those without CAD (23.3 ng/mL vs 19.8 ng/mL, P=0.008), although they decreased over time. Also, baseline serum SFRP5 levels were inversely correlated with peak hypersensitive cardiac troponin I (hs-cTnI) levels (r=-0.234, P=0.025) and peak hypersensitive C-reactive protein (hs-CRP) levels (r=-0.262, P=0.015). A multivariate linear regression model showed that changes in LVEF were positively correlated with serum SFRP5 levels at baseline (β= 0.249, 95% confidence interval (CI) 0.018-0.245, P=0.024) and 24 h after admission (β=0.220, 95% CI 0.003-0.264, P=0.045). At 3 months, LVEF in patients with high SFRP5 levels was significantly improved over baseline [(60.8±7.1) % vs (56.1±7.5) %, P=0.001]. LVEF was also significantly higher in patients with high SFRP5 levels than in those with low at the 3-month follow-up [(60.8±7.1) % vs (56.8±8.9) %, P=0.028]. Consequently, high serum SFRP5 levels at baseline were associated with a decreased risk of reduced LVEF at 3 months, independent of peak hs-cTnI and baseline cardiac function (hazard ratio 0.190, 95% CI 0.036-0.996; P=0.049).

CONCLUSIONS

High serum SFRP5 levels measured during the acute phase of STEMI were significantly associated with promoting myocardial recovery at an early phase following primary PCI, suggesting that SFRP5 is a potential therapeutic target in acute STEMI.

The cross-talk between adipokines and miRNAs in health and obesity-mediated diseases

BACKGROUND

Multiple studies have revealed a direct correlation between obesity and the development of multiple comorbidities, including metabolic diseases, cardiovascular disorders, chronic inflammatory disease, and cancers. However, the molecular mechanism underlying the link between obesity and the progression of these diseases is not completely understood. Adipokines are factors that are secreted by adipocytes and play a key role in whole body homeostasis. Collaboratively, miRNAs are suggested to have key functions in the development of obesity and obesity-related disorders. Based on recently emerging evidence, obesity leads to the dysregulation of both adipokines and obesity-related miRNAs. In the present study, we described the correlations between obesity and its related diseases that are mediated by the mutual regulatory effects of adipokines and miRNAs.

METHODS

We reviewed current knowledge of the modulatory effects of adipokines on miRNAs activity and their relevant functions in pathological conditions and vice versa.

RESULTS

Our research reveals the ability of adipokines and miRNAs to control the expression and activity of the other class of molecules, and their effects on obesity-related diseases.

CONCLUSIONS

This study may help researchers develop a roadmap for future investigations and provide opportunities to develop new therapeutic and diagnostic methods for treating obesity-related diseases.

Sfrp5/Wnt Pathway: A Protective Regulatory System in Atherosclerotic Cardiovascular Disease

Adipose tissue stores energy and is the largest endocrine organ in the body, producing several adipokines. However, among these adipokines, few play a role in the positive metabolism that promotes good health. Secreted frizzled-related protein (Sfrp)-5, an antagonist that directly binds to Wnt, has attracted interest due to its favorable effects on atherosclerotic cardiovascular disease (ASCVD). This review focuses on Sfrp5 biology and the roles of the Sfrp5/Wnt system in ASCVD.

The relevance of microRNA in post-infarction left ventricular remodelling and heart failure

Myocardial infarction and post-infarction left ventricular remodelling involve a high risk of morbidity and mortality. For this reason, ongoing research is being conducted in order to learn the mechanisms of unfavourable left ventricular remodelling following a myocardial infarction. New biomarkers are also being sought that would allow for early identification of patients with a high risk of post-infarction remodelling and dysfunction of the left ventricle. In recent years, there has been ever more experimental data that confirms the significance of microRNA in cardiovascular diseases. It has been confirmed that microRNAs are stable in systemic circulation, and can be directly measured in patients' blood. It has been found that significant changes occur in the concentrations of various types of microRNA in myocardial infarction and heart failure patients. Various types of microRNA are also currently being intensively researched in terms of their usefulness as markers of cardiomyocyte necrosis, and predictors of the post-infarction heart failure development. This paper is a summary of the current knowledge on the significance of microRNA in post-infarction left ventricular remodelling and heart failure.

Tumor-secreted extracellular vesicles promote the activation of cancer-associated fibroblasts via the transfer of microRNA-125b

Tumour cells release large quantities of extracellular vesicles (EVs) to mediate their interactions with other cells in the tumour microenvironment. To identify host cells that naturally take up EVs from tumour cells, we created breast cancer cell lines secreting fluorescent EVs. These fluorescent EVs are taken up most robustly by fibroblasts within the tumour microenvironment. RNA sequencing indicated that miR-125b is one of the most abundant microRNAs secreted by mouse triple-negative breast cancer 4T1 and 4TO7 cells. Treatment with 4T1 EVs leads to an increase in fibroblast activation in isogenic 4TO7 tumours, which is reversed by blocking miR-125b in 4T1 EVs; hence, miR-125b delivery by EVs is responsible for fibroblast activation in mouse tumour models. miR-125b is also secreted by human breast cancer cells and the uptake of EVs from these cells significantly increases cellular levels of miR-125b and expression of multiple cancer-associated fibroblast markers in resident fibroblasts. Overexpression of miR-125b in both mouse and human fibroblasts leads to an activated phenotype similar to the knockdown of established miR-125b target mRNAs. These data indicate that miR-125b is transferred through EVs from breast cancer cells to normal fibroblasts within the tumour microenvironment and contributes to their development into cancer-associated fibroblasts.

Exosomes derived from human umbilical cord mesenchymal stem cells improve myocardial repair via upregulation of Smad7

It has been previously reported that exosomes derived from human umbilical cord mesenchymal stem cells (hucMSC)‑exosomes exhibit cardioprotective effects on the rat acute myocardial infarction (AMI) models and cardiomyocyte hypoxia injury models in vitro, however the exact mechanisms involved require further investigation. The present study aimed to investigate the repair effects of hucMSC‑exosomes on myocardial injury via the regulation of mothers against decapentaplegic homolog 7 (Smad7) expression. Compared with sham or normoxia groups (in vivo and in vitro, respectively), western blotting demonstrated that Smad7 expression was significantly decreased in the borderline area of infraction myocardium and in H9C2(2‑1) cells following hypoxia‑induced injury. Additionally, microRNA (miR)‑125b‑5p expression was markedly increased using reverse transcription‑quantitative polymerase chain reaction, but was reversed by hucMSC‑exosomes. Trypan blue staining and lactate dehydrogenase release detection demonstrated that cell injury was significantly increased in the AMI + PBS and hypoxia group compared with in the sham and normoxia groups and was inhibited by hucMSC‑exosomes. A dual luciferase reporter gene assay confirmed that Smad7 is a target gene of miR‑125b‑5p. In addition, miR‑125b‑5p mimics promoted H9C2(2‑1) cell injury following 48 h exposure to hypoxia. Downregulation of Smad7 expression under hypoxia was increased by miR‑125b‑5p mimics compared with the mimic negative control, and hucMSC‑exosomes partially alleviated this phenomenon. In conclusion, hucMSC‑exosomes may promote Smad7 expression by inhibiting miR‑125b‑5p to increase myocardial repair. The present study may provide a potential therapeutic approach to improve myocardial repair following AMI.

SFRP5 is a target gene transcriptionally regulated by PPARγ in 3T3-L1 adipocytes

Secreted frizzled-related protein 5 (SFRP5) is a newly identified adipokine. SFRP5 expression increases during the differentiation and maturation of adipocytes, but the factors regulating SFRP5 expression during this process remain unclear. This study showed that peroxisome proliferator-activated receptor γ (PPARγ) adenovirus transfection could enhance the SFRP5 expression of 3T3-L1 adipocytes. Three potential binding sites of PPARγ in the SFRP5 promoter domain were found by bioinformatics analysis. Luciferase reporter gene assay demonstrated that PPARγ regulated the activity of the SFRP5 promoter through cis-acting elements at -2,284--1,500bp. Further experiments verified that PPARγ could specifically bind to the SFRP5 promoter at -2,284--2,263bp using chromatin immunoprecipitation and electrophoretic mobility shift assay. These results suggest that SFRP5 be a target gene of PPARγ, and its expression may be under the transcriptional regulation of PPARγ.