MicroRNA-29 regulates myocardial microvascular endothelial cells proliferation and migration in association with IGF1 in type 2 diabetes

The various role of microRNAs in breast cancer angiogenesis, with a special focus on novel miRNA-based delivery strategies

After skin malignancy, breast cancer is the most widely recognized cancer detected in women in the United States. Breast cancer (BCa) can happen in all kinds of people, but it's much more common in women. One in four cases of cancer and one in six deaths due to cancer are related to breast cancer. Angiogenesis is an essential factor in the growth of tumors and metastases in various malignancies. An expanded level of angiogenesis is related to diminished endurance in BCa patients. This function assumes a fundamental part inside the human body, from the beginning phases of life to dangerous malignancy. Various factors, referred to as angiogenic factors, work to make a new capillary. Expanding proof demonstrates that angiogenesis is managed by microRNAs (miRNAs), which are small non-coding RNA with 19-25 nucleotides. MiRNA is a post-transcriptional regulator of gene expression that controls many critical biological processes. Endothelial miRNAs, referred to as angiomiRs, are probably concerned with tumor improvement and angiogenesis via regulation of pro-and anti-angiogenic factors. In this article, we reviewed therapeutic functions of miRNAs in BCa angiogenesis, several novel delivery carriers for miRNA-based therapeutics, as well as CRISPR/Cas9 as a targeted therapy in breast cancer.

MiR-29a regulates cardiomyocyte apoptosis by targeting Bak1 in diabetic cardiomyopathy

This study sought to investigate the association between microRNA-29a (miR-29a) and cardiomyocyte apoptosis in diabetic cardiomyopathy (DCM). DCM rat model was established by treating rats with streptozotocin (STZ), followed by injection of NC or miR-29a-3p mimics into the myocardium of rats. High glucose (HG)-treated H9c2 cells were transfected with NC and miR-29a-3p mimics. DCM rats presented elevated levels of blood glucose, HbA1c, and blood pressure and urine output and decreased body weight and cardiac contractile function after modeling. MiR-29a was lowly expressed in STZ-treated rats and HG-treated H9c2 cells. Upregulation of miR-29a improved cardiac structure and function and attenuated, alleviated myocardial histological abnormalities and fibrosis, and lowered cardiomyocyte apoptosis in DCM rats. Meanwhile, HG promoted H9c2 cell apoptosis, while miR-29a overexpression attenuated the function of HG. Compared with control group, the protein expression of Bax, cleaved-caspase3 and Bak1 in DCM and HG group were significantly upregulated, and the expression of Bcl-2 and Mcl-1 were downregulated, while miR-29a overexpression exerted opposite effect. Bioinformatics prediction method and western blot revealed that miR-29a directly targeted Bak1 and downregulated Bak1 expression. Overall, miR-29a regulated STZ- and HG-induced cardiomyocyte apoptosis by targeting Bak1, providing a novel understanding of the pathogenesis of DCM.

Long non-coding RNAs and microRNAs as crucial regulators in cardio-oncology

Cancer is one of the leading causes of morbidity and mortality worldwide. Significant improvements in the modern era of anticancer therapeutic strategies have increased the survival rate of cancer patients. Unfortunately, cancer survivors have an increased risk of cardiovascular diseases, which is believed to result from anticancer therapies. The emergence of cardiovascular diseases among cancer survivors has served as the basis for establishing a novel field termed cardio-oncology. Cardio-oncology primarily focuses on investigating the underlying molecular mechanisms by which anticancer treatments lead to cardiovascular dysfunction and the development of novel cardioprotective strategies to counteract cardiotoxic effects of cancer therapies. Advances in genome biology have revealed that most of the genome is transcribed into non-coding RNAs (ncRNAs), which are recognized as being instrumental in cancer, cardiovascular health, and disease. Emerging studies have demonstrated that alterations of these ncRNAs have pathophysiological roles in multiple diseases in humans. As it relates to cardio-oncology, though, there is limited knowledge of the role of ncRNAs. In the present review, we summarize the up-to-date knowledge regarding the roles of long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) in cancer therapy-induced cardiotoxicities. Moreover, we also discuss prospective therapeutic strategies and the translational relevance of these ncRNAs.

Quercetin‑conjugated superparamagnetic iron oxide nanoparticles modulate glucose metabolism-related genes and miR-29 family in the hippocampus of diabetic rats

Quercetin (QC) is a dietary bioflavonoid that can be conjugated with nanoparticles to facilitate its brain bioavailability. We previously showed that quercetin-conjugated superparamagnetic iron oxide nanoparticles (QCSPIONs) reduced the level of blood glucose in diabetic rats. Glucose transporters (GLUTs), insulin-like growth factor-1 (IGF-1), and microRNA-29 (miR-29) play a critical role in brain glucose homeostasis. In the current study, we examined the effects of QCSPION on the expression of glucose metabolism-related genes, and the miR-29 family as a candidate regulator of glucose handling in the hippocampus of diabetic rats. Our in silico analyses introduce the miR-29 family as potential regulators of glucose transporters and IGF-1 genes. The expression level of the miR-29 family, IGF-1, GLUT1, GLUT2, GLUT3, and GLUT4 were measured by qPCR. Our results indicate that diabetes significantly results in upregulation of the miR-29 family and downregulation of the GLUT1, 2, 3, 4, and IGF-1 genes. Interestingly, QCSPIONs reduced miR-29 family expression and subsequently enhanced GLUT1, 2, 3, 4, and IGF-1expression. In conclusion, our findings suggest that QCSPION could regulate the expression of the miR-29 family, which in turn increases the expression of glucose transporters and IGF-1, thereby reducing diabetic complications.

MicroRNA‑29‑3p regulates the β‑catenin pathway by targeting IGF1 to inhibit the proliferation of prolactinoma cells

The present study aimed to analyze the effects and underlying mechanisms of microRNA (miR)-29-3p on the proliferation and secretory abilities of prolactinoma cells by targeting insulin-like growth factor (IGF)-1/β-catenin. The relationship between miR-29a-3p and the survival of prolactinoma cells was analyzed with the Kaplan-Meier method in reference to The Cancer Genome Atlas. The expression levels of miR-29a-3p and IGF-1 in MMQ and GH3 cells were detected. A dual-luciferase reporter gene assay was performed to verify the combination of miR-29a-3p and IGF-1. Cells were transfected with a miR-29a-3p mimic and/or IGF-1 pcDNA3.1 to analyze the effects on the proliferation, apoptosis and secretion of prolactin (PRL) and growth hormone (GH) of prolactinoma cells. The effects on β-catenin in the cytoplasm and nucleus were investigated by western blot analysis. The results showed that miR-29a-3p expression was low in MMQ and GH3 cells. Overexpression miR-29a-3p inhibited IGF-1 mRNA and protein expression. miR-29a-3p inhibited cell proliferation and PRL and GH expression, and promoted apoptosis by inhibiting IGF-1. Increasing the expression of miR-29a-3p increased β-catenin levels in the cytoplasm, whereas IGF-1 promoted β-catenin activation and entry into the nucleus, and reversed the inhibitory effects of miR-29a-3p on β-catenin. To conclude, miR-29a-3p inhibited the proliferation and secretory abilities of prolactinoma cells by inhibiting nuclear translocation of β-catenin via a molecular mechanism that is inseparable from IGF-1.

miR-142-5p regulates the progression of diabetic retinopathy by targeting IGF1

As one of leading causes of blindness, diabetic retinopathy (DR) is a progressive microvascular complication of diabetes mellitus (DM). Despite significant efforts have been devoted to investigate DR over the years, the molecular mechanisms still remained unclear. Emerging evidences demonstrated that microRNAs (miRNAs) were tightly associated with pathophysiological development of DR. Hence, this study was aimed to illustrate the role and molecular mechanisms of miR-412-5p in progression of DR. Streptozotocin (STZ) treatment in rats and human retinal endothelial cell (HREC) models were used to simulate DR conditions in vivo and in vitro. Hematoxylin-eosin (HE) staining was used to demonstrate the morphology of retinal tissues of rats. Qualitative real-time polymerase chain reaction (qRT-PCR) detected miR-142-5p and vascular endothelial growth factor (VEGF) expression levels. Cell counting kit-8 (CCK8) assay and immunofluorescence (IF) measured the cell proliferation rates. Western blot tested the expression status of IGF1/IGF1R-mediated signaling pathway. Dual-luciferase reporter assays demonstrated the molecular mechanism of miR-142-5p. miR-142-5p level was down-regulated in retinal tissues of DR rats and high glucose (HG)-treated HRECs. Insulin-like growth factor 1 (IGF1) was identified as a direct target of miR-142-5p. The reduced miR-142-5p level enhanced HRECs proliferation via activating IGF/IGF1R-mediated signaling pathway including p-PI3K, p-ERK, p-AKT, and VEGF activation, ultimately giving rise to cell proliferation. Either miR-142-5p overexpression or IGF1 knockdown alleviated the pathological effects on retinal tissues in DR rats. Collectively, miR-142-5p participated in DR development by targeting IGF1/p-IGF1R signaling pathway and VEGF generation. This miR-142-5p/IGF1/VEGF axis provided a novel therapeutic target for DR clinical treatment.

A Comprehensive miRNome Analysis of Macrophages Isolated from db/db Mice and Selected miRNAs Involved in Metabolic Syndrome-Associated Cardiac Remodeling

Cardiac macrophages are known from various activities, therefore we presume that microRNAs (miRNAs) produced or released by macrophages in cardiac tissue have impact on myocardial remodeling in individuals with metabolic syndrome (MetS). We aim to assess the cardiac macrophage miRNA profile by selecting those miRNA molecules that potentially exhibit regulatory functions in MetS-related cardiac remodeling. Cardiac tissue macrophages from control and db/db mice (an animal model of MetS) were counted and sorted with flow cytometry, which yielded two populations: CD45+CD11b+CD64+Ly6Chi and CD45+CD11b+CD64+Ly6Clow. Total RNA was then isolated, and miRNA expression profiles were evaluated with Next Generation Sequencing. We successfully sequenced 1400 miRNAs in both macrophage populations: CD45+CD11b+CD64+Ly6Chi and CD45+CD11b+CD64+Ly6Clow. Among the 1400 miRNAs, about 150 showed different expression levels in control and db/db mice and between these two subpopulations. At least 15 miRNAs are possibly associated with MetS pathology in cardiac tissue due to direct or indirect regulation of the expression of miRNAs for proteins involved in angiogenesis, fibrosis, or inflammation. In this paper, for the first time we describe the miRNA transcription profile in two distinct macrophage populations in MetS-affected cardiac tissue. Although the results are preliminary, the presented data provide a foundation for further studies on intercellular cross-talk/molecular mechanism(s) involved in the regulation of MetS-related cardiac remodeling.

miR-29 family: A potential therapeutic target for cardiovascular disease

Cardiovascular disease (CVD), including heart failure, myocardial fibrosis and myocardial infarction, etc, remains one of the leading causes of mortality worldwide. Evidence shows that miRNA plays an important role in the pathogenesis of CVD. miR-29 family is one of miRNA, and over the past decades, many studies have demonstrated that miR-29 is involved in maintaining the integrity of arteries and in the regulation of atherosclerosis, especially in the process of myocardial fibrosis. Besides, heart failure, myocardial fibrosis and myocardial infarction are inseparable from the regulatory role of miR-29. Here, we comprehensively review recent studies regarding miR-29 and CVD, illustrate the possibility of miR-29 as a potential marker for prevention, treatment and prognostic observation.

BMSC-Derived Exosomal miR-29a Promotes Angiogenesis and Osteogenesis

Angiogenesis and osteogenesis are tightly coupled during bone modeling and remodeling processes. Here we reported that bone marrow mesenchymal stem cell (BMSC)-derived exosomal miR-29a promotes angiogenesis and osteogenesis in vitro and in vivo. BMSC-derived exosomes (BMSCs-Exos) can be taken up by human umbilical vein endothelial cells (HUVECs) and promote the proliferation, migration, and tube formation of HUVECs. MiRNA-29a level was high in BMSCs-Exos and can be transported into HUVECs to regulate angiogenesis. VASH1 was identified as a direct target of miR-29a, mediating the effects of BMSC-derived exosomal miR-29a on angiogenesis. More interestingly, miR29a-loaded exosomes from engineered BMSCs (miR-29a-loaded BMSCs-Exos) showed a robust ability of promoting angiogenesis and osteogenesis in vivo. Taken together, these findings suggest that BMSC-derived exosomal miR-29a regulates angiogenesis and osteogenesis, and miR-29a-loaded BMSCs-Exos may serve as a potential therapeutic target for osteoporosis.

Downregulated miR-204 Promotes Skeletal Muscle Regeneration

Skeletal muscle is the most abundant and a highly plastic tissue of the mammals, especially when it comes to regenerate after trauma, but there is limited information about the mechanism of muscle repair and its regeneration. In the present study, we found that miR-204 is downregulated after skeletal muscle injury. In vitro experiments showed that over-expression of miR-204 by transfecting with miR-204 mimics suppressed C2C12 cell proliferation, migration, and blocked subsequent differentiation, whereas inhibition of miR-204 by transfecting with miR-204 inhibitor showed the converse effects. Furthermore, through the dual luciferase reporter system, we demonstrated that miR-204 can target the 3'UTR regions of Pax7, IGF1, and Mef2c and inhibit their expression. Taken together, our results suggest that Pax7, IGF1, and Mef2c are the target genes of miR-204 in the process of myoblasts proliferation, cell migration, and differentiation, respectively, and may contribute to mouse skeletal muscle regeneration. Our results may provide new ideas and references for the skeletal muscle study and may also provide therapeutic strategies of skeletal muscle injury.

Coronary vascular growth matches IGF-1-stimulated cardiac growth in fetal sheep

As loss of contractile function in heart disease could often be mitigated by increased cardiomyocyte number, expansion of cardiomyocyte endowment paired with increased vascular supply is a desirable therapeutic goal. Insulin-like growth factor 1 (IGF-1) administration increases fetal cardiomyocyte proliferation and heart mass, but how fetal IGF-1 treatment affects coronary growth and function is unknown. Near-term fetal sheep underwent surgical instrumentation and were studied from 127 to 134 d gestation (term = 147 d), receiving either IGF-1 LR3 or vehicle. Coronary growth and function were interrogated using pressure-flow relationships, an episode of acute hypoxia with progressive blockade of adenosine receptors and nitric oxide synthase, and by modeling the determinants of coronary flow. The main findings were that coronary conductance was preserved on a per-gram basis following IGF-1 treatment, adenosine and nitric oxide contributed to hypoxia-mediated coronary vasodilation similarly in IGF-1-treated and Control fetuses, and the relationships between coronary flow and blood oxygen contents were similar between groups. We conclude that IGF-1-stimulated fetal myocardial growth is accompanied by appropriate expansion and function of the coronary vasculature. These findings support IGF-1 as a potential strategy to increase cardiac myocyte and coronary vascular endowment at birth.

MiR-486-5p inhibits the hyperproliferation and production of collagen in hypertrophic scar fibroblasts via IGF1/PI3K/AKT pathway

Background: This study explored the function and mechanism of miR-486-5p in HSFBs.Methods: Qualitative real-time-polymerase chain reaction (qRT-PCR) was performed to detect the expression of miR-486-5p in HS and hypertrophic scar fibroblasts (HSFBs). Viability, migration, invasion ability, apoptosis, and expressions of Collagen I, Collagen III, α-SMA and Cleaved caspase-3 in HSFBs after transfection with miR-486-5p mimic or inhibitor were measured by CCK-8, wound-healing, transwell, and Western blot, respectively. Interaction between miR-486-5p and IGF1 was predicted by Targetscan version 7.2 and further confirmed by dual-luciferase assay, and functional rescue experiments were conducted to verify the predicted molecular mechanism. The activation of PI3K/AKT pathway was also analyzed by Western blot.Results: MiR-486-5p was low-expressed in HS and HSFBs, and that overexpression of miR-486-5p suppressed the viability, migration, invasion, and expressions of Collagen I, Collagen III, and α-SMA of HSFBs, meanwhile, it also promoted apoptosis and Cleaved caspase-3 expression in HSFBs. Moreover, IGF1 was targeted by miR-486-5p, and increased viability, migration, invasion, and collagens expressions, the activation of PI3K/Akt pathway, and decreased apoptosis and Cleaved caspase-3 induced by miR-486-5p inhibitor could be partly alleviated by siIGF1.Conclusions: Overexpressed miR-486-5p inhibited the hyperproliferation and excessive production of collagen in HSFBs via IGF1/PI3K/AKT pathway.

A therapeutic approach towards microRNA29 family in vascular diabetic complications: A boon or curse?

Diabetes Mellitus (DM) is one of the major metabolic disorders and its severity leads to death. Enhancement in hyperglycaemic conditions of DM gives rise to endothelial impairment in small and large blood vessels contributing towards microvascular and macrovascular complications respectively. The pathogenesis of diabetic complications is associated with interruption of various signal transduction pathways due to epigenetic modifications such as aberrant histone modifications, DNA methylation and expression of miRNAs along with the long non-coding RNAs (lncRNAs). Amongst these epigenetic alterations, modulated expressions of miRNAs confer to apoptosis and endothelial dysfunction of organs that gives rise to vascular complications. In this review, we principally focussed on physiological role of miR29 family in DM and have discussed crosstalk between miR29 family and numerous genes involved in signal transduction pathways of Diabetic vascular complications. Incidences of diabetic retinopathy exploiting the role of miR29 in regulation of EMT process, differential expression patterns of miR29 and promising therapeutic role of miR29 have been discussed. We have summarised the therapeutic role of miR29 in podocyte impairment and how miR29 regulates the expressions of profibrotic, inflammatory and ECM encoding genes in renal fibrosis under diabetic conditions. We have also highlighted impact of miR29 expression patterns in cardiac angiopathy, cardiomyocyte's apoptosis and cardiac fibrosis. Additionally, we have also presented the contradictory actions of miR29 family in amelioration as well as in enhancement of diabetic complications.

MiRNA-575 suppresses angiogenesis by targeting Rab5-MEK-ERK pathway in endothelial cells

Hypertension is a major risk factor for the development of atherosclerosis. Increased carotid intima-media thickness (CIMT) is generally considered as an early marker of atherosclerosis. Recently, circulating miRNAs have been implicated both as sensitive biomarkers and key regulators in the development of atherosclerosis. However, the biological functions and molecular regulatory mechanisms for miR-575 on angiogenesis remain unknown. In our study, we first identified up-regulation of circulating miR-575 in plasma of essential hypertensive patients with increased CIMT (iCIMT) compared with those patients with normal CIMT (nCIMT). Furthermore, the overexpression of miR-575 in human umbilical vein endothelial cells (HUVECs) by its mimics significantly inhibited migration and proliferation as well as induction of apoptosis of HUVECs. Inhibition of miR-575 performed the reverse effects of HUVECs. We further suggested Rab5B was the downstream target of miR-575 and knockdown of Rab5B significantly inhibited migration and proliferation of HUVECs. Overexpression of Rab5B largely rescued the miR-575-mediated impairment of angiogenesis processes including: cell proliferation, migration, and apoptosis as well as activation of mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK-ERK) signaling. Therefore, our results uncover a novel role of miR-575 in endothelial cells, implying a potential biomarker and clinical target for atherosclerosis in hypertensive patients.

The regulatory role of microRNAs in angiogenesis-related diseases

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression at a post-transcriptional level via either the degradation or translational repression of a target mRNA. They play an irreplaceable role in angiogenesis by regulating the proliferation, differentiation, apoptosis, migration and tube formation of angiogenesis-related cells, which are indispensable for multitudinous physiological and pathological processes, especially for the occurrence and development of vascular diseases. Imbalance between the regulation of miRNAs and angiogenesis may cause many diseases such as cancer, cardiovascular disease, aneurysm, Kawasaki disease, aortic dissection, phlebothrombosis and diabetic microvascular complication. Therefore, it is important to explore the essential role of miRNAs in angiogenesis, which might help to uncover new and effective therapeutic strategies for vascular diseases. This review focuses on the interactions between miRNAs and angiogenesis, and miRNA-based biomarkers in the diagnosis, treatment and prognosis of angiogenesis-related diseases, providing an update on the understanding of the clinical value of miRNAs in targeting angiogenesis.

FMRP regulates endothelial cell proliferation and angiogenesis via the miR-181a-CaM-CaMKII pathway

RNA binding proteins (RBPs) and microRNAs have emerged as crucial post-transcriptional regulators of gene expression. Although the role of Fragile X mental retardation protein (FMRP) has been well studied in the brain, the function of FMRP in endothelial cells remains unknown. In our study, we showed that FMRP controlled human umbilical vein endothelial cells (HUVECs) proliferation and angiogenesis via the miR-181a-mediated calmodulin (CaM)/CaMKII pathway. The knockdown of FMRP induced miR-181a expression and contributed to endothelial cell proliferation and angiogenesis. Furthermore, we identified CaM as a downstream target of miR-181a in endothelial cells. Additionally, tumor necrosis factor-ɑ (TNF-ɑ) treatment specifically decreased the activity of the CaM/CaMKII pathway through the dephosphorylation of FMRP and upregulation of miR-181a. Finally, the overexpression of constitutively phosphorylated FMRP rescued the TNF-ɑ-impaired endothelial cell proliferation and angiogenesis by activating the CaM/CaMKII pathway and downregulating miR-181a, which suggested there was a pivotal role of FMRP in vascular integrity in response to inflammatory stimuli. Thus, our study supports a novel function and mechanism involving FMRP and the miR-181a-CaM-CaMKII pathway may be a therapeutic target for protecting against inflammation-induced vascular diseases.

miR-29c plays a suppressive role in breast cancer by targeting the TIMP3/STAT1/FOXO1 pathway

Background

miR-29c has been associated with the progression of many cancers. However, the function and mechanism of miR-29c have not been well investigated in breast cancers.

Methods

Real-time quantitative PCR was used to assess expression of miR-29c and DNMT3B mRNA. Western blot and immunochemistry were used to examine the expression of DNA methyltransferase 3B (DNMT3B) protein in breast cancer cells and tissues. The functional roles of miR-29c in breast cancer cells such as proliferation, migration, invasion, colony formation, and 3D growth were evaluated using MTT, transwell chambers, soft agar, and 3D Matrigel culture, respectively. In addition, the luciferase reporter assay was used to check if miR-29c binds the 3'UTR of DNMT3B. The effects of miR-29c on the DNMT3B/TIMP3/STAT1/FOXO1 pathway were also examined using Western blot and methyl-specific qPCR. The specific inhibitor of STAT1, fludarabine, was used to further check the mechanism of miR-29c function in breast cancer cells. Studies on cell functions were carried out in DNMT3B siRNA cell lines.

Results

The expression of miR-29c was decreased with the progression of breast cancers and was closely associated with an overall survival rate of patients. Overexpression of miR-29c inhibited the proliferation, migration, invasion, colony formation, and growth in 3D Matrigel while knockdown of miR-29c promoted these processes in breast cancer cells. In addition, miR-29c was found to bind 3'UTR of DNMT3B and inhibits the expression of DNMT3B, which was elevated in breast cancers. Moreover, the protein level of TIMP3 was reduced whereas methylation of TIMP3 was increased in miR-29c knockdown cells compared to control. On the contrary, the protein level of TIMP3 was increased whereas methylation of TIMP3 was reduced in miR-29c-overexpressing cells compared to control. Knockdown of DNMT3B reduced the proliferation, migration, and invasion of breast cancer cell lines. Finally, our results showed that miR-29c exerted its function in breast cancers by regulating the TIMP3/STAT1/FOXO1 pathway.

Conclusion

The results suggest that miR-29c plays a significant role in suppressing the progression of breast cancers and that miR-29c may be used as a biomarker of breast cancers.