CircRNA TGFBR2/MiR-25-3p/TWIST1 axis regulates osteoblast differentiation of human aortic valve interstitial cells

Emerging biological functions of Twist1 in cell differentiation

Twist1 is required for embryonic development and expresses after birth in mesenchymal stem cells derived from mesoderm, where it governs mesenchymal cell development. As a well-known regulator of epithelial-mesenchymal transition or embryonic organogenesis, Twist1 is important in a variety of developmental systems, including mesoderm formation, neurogenesis, myogenesis, cranial neural crest cell migration, and differentiation. In this review, we first highlight the physiological significance of Twist1 in cell differentiation, including osteogenic, chondrogenic, and myogenic differentiation, and then detail its probable molecular processes and signaling pathways. On this premise, we summarize the significance of Twist1 in distinct developmental disorders and diseases to provide a reference for studies on cell differentiation/development-related diseases.

Long non-coding RNA FGD5 antisense RNA 1 targets Baculovirus inhibitor 5 via microRNA-497-5p to alleviate calcific aortic valve disease

Calcific aortic valve disease (CAVD) is featured by thickening and calcification of the aortic valve. Osteoblast differentiation is a crucial step in valve calcification. Long non-coding RNAs (LncRNAs) participate in the osteogenic differentiation of mesenchymal cells. However, the character of lncRNA FGD5 antisense RNA 1 (FGD5-AS1) in CAVD is uncertain. After collection of human aortic valve tissue samples, detection of FGD5-AS1, microRNA (miR)-497-5p and Baculovirus inhibitor 5 (BIRC5) was conducted. Valve mesenchymal cells were isolated from CAVD patients and induced to differentiate to osteoblasts, and transfected with FGD5-AS1, miR-497-5p and BIRC5 plasmids. Detection of the alkaline phosphatase activity was after osteogenic induction of human aortic valve interstitial cells (hAVICs); Detection of the degree of calcium nodules and osteoblast differentiation markers (RUNX2 and OPN) was conducted. After establishment of a mouse model of CAVD, detection of the thickness of aortic valve leaflets, and the degree of calcification of the valve leaflets, and evaluation of echocardiographic parameters were implemented. Experimental data manifested in CAVD patients, lncRNAFGD5-AS1 and BIRC5 were reduced, but miR-497-5p was elevated; Enhancing lncRNA FGD5-AS1 or repressing miR-497-5p mitigated CAVD by restraining osteogenic differentiation; LncRNA FGD5-AS1 sponged miR-497-5p to target BIRC5; Repressive BIRC5 turned around the therapeutic action of elevated FGD5-AS1 or depressed miR-497-5p on hAVICs; Enhancive FGD5-AS1 in vivo was available to reduce ApoE-/- mouse CAVD induced via high cholesterol diet. All in all, lncRNAFGD5-AS1 targets BIRC5 via miR-497-5p to alleviate CAVD.

Differentiation of osteoblasts: the links between essential transcription factors

Osteoblasts, cells derived from mesenchymal stem cells (MSCs) in the bone marrow, are cells responsible for bone formation and remodeling. The differentiation of osteoblasts from MSCs is triggered by the expression of specific genes, which are subsequently controlled by pro-osteogenic pathways. Mature osteoblasts then differentiate into osteocytes and are embedded in the bone matrix. Dysregulation of osteoblast function can cause inadequate bone formation, which leads to the development of bone disease. Various key molecules are involved in the regulation of osteoblastogenesis, which are transcription factors. Previous studies have heavily examined the role of factors that control gene expression during osteoblastogenesis, both in vitro and in vivo. However, the systematic relationship of these transcription factors remains unknown. The involvement of ncRNAs in this mechanism, particularly miRNAs, lncRNAs, and circRNAs, has been shown to influence transcriptional factor activity in the regulation of osteoblast differentiation. Here, we discuss nine essential transcription factors involved in osteoblast differentiation, including Runx2, Osx, Dlx5, β-catenin, ATF4, Ihh, Satb2, and Shn3. In addition, we summarize the role of ncRNAs and their relationship to these essential transcription factors in order to improve our understanding of the transcriptional regulation of osteoblast differentiation. Adequate exploration and understanding of the molecular mechanisms of osteoblastogenesis can be a critical strategy in the development of therapies for bone-related diseases.Communicated by Ramaswamy H. Sarma.

The Role of MicroRNAs in Aortic Stenosis-Lessons from Recent Clinical Research Studies

Aortic stenosis (AS) is the most prevalent primary valve lesion demanding intervention. Two main treatment options are surgical aortic valve replacement or transcatheter aortic valve implantation. There is an unmet need for biomarkers that could predict treatment outcomes and become a helpful tool in guiding Heart Team in the decision-making process. Micro-ribonucleic acids (microRNAs/miRs) have emerged as potential biomarkers thoroughly studied in recent years. In this review, we aimed to summarize the current knowledge about the role of miRNAs in AS based on human subject research. Much research investigating miRNAs' role in AS has been conducted so far. We included 32 original human subject research relevant to the discussed field. Most of the presented miRNAs were studied only by a single research group. Nevertheless, several miRNAs appeared more than once, sometimes with high consistency between different studies but sometimes with apparent discrepancies. The molecular aspects of diseases are doubtlessly exciting and provide invaluable insights into the pathophysiology. Nevertheless, translating these findings, regarding biomarkers such as miRNAs, into clinical practice requires much effort, time, and further research with a focus on validating existing evidence.

Bioinformatics-Based Identification of CircRNA-MicroRNA-mRNA Network for Calcific Aortic Valve Disease

Background

Calcific aortic valve disease (CAVD) is the most common native valve disease. Valvular interstitial cell (VIC) osteogenic differentiation and valvular endothelial cell (VEC) dysfunction are key steps in CAVD progression. Circular RNA (circRNAs) is involved in regulating osteogenic differentiation with mesenchymal cells and is associated with multiple disease progression, but the function of circRNAs in CAVD remains unknown. Here, we aimed to investigate the effect and potential significance of circRNA-miRNA-mRNA networks in CAVD.

Methods

Two mRNA datasets, one miRNA dataset, and one circRNA dataset of CAVD downloaded from GEO were used to identify DE-circRNAs, DE-miRNAs, and DE-mRNAs. Based on the online website prediction function, the common mRNAs (FmRNAs) for constructing circRNA-miRNA-mRNA networks were identified. GO and KEGG enrichment analyses were performed on FmRNAs. In addition, hub genes were identified by PPI networks. Based on the expression of each data set, the circRNA-miRNA-hub gene network was constructed by Cytoscape (version 3.6.1).

Results

32 DE-circRNAs, 206 DE-miRNAs, and 2170 DE-mRNAs were identified. Fifty-nine FmRNAs were obtained by intersection. The KEGG pathway analysis of FmRNAs was enriched in pathways in cancer, JAK-STAT signaling pathway, cell cycle, and MAPK signaling pathway. Meanwhile, transcription, nucleolus, and protein homodimerization activity were significantly enriched in GO analysis. Eight hub genes were identified based on the PPI network. Three possible regulatory networks in CAVD disease were obtained based on the biological functions of circRNAs including: hsa_circ_0026817-hsa-miR-211-5p-CACNA1C, hsa_circ_0007215-hsa-miR-1252-5p-MECP2, and hsa_circ_0007215-hsa-miR-1343-3p- RBL1.

Conclusion

The present bionformatics analysis suggests the functional effect for the circRNA-miRNA-mRNA network in CAVD pathogenesis and provides new targets for therapeutics.

Antidepressant-like effects of geniposide in chronic unpredictable mild stress-induced mice by regulating the circ_0008405/miR-25-3p/Gata2 and Oip5os1/miR-25-3p/Gata2 networks

Evidence exists suggesting the anti-depressive activities of geniposide (GP), a major compound in Gardenia jasminoides Ellis. Accordingly, the present study attempts to explore the anti-depressive mechanism of GP in chronic unpredictable mild stress (CUMS)-induced depression-like behaviors of mice. CUMS-induced mice were given GP daily and subjected to behavioral tests to observe the effect of GP on the depression-like behaviors. It was noted that GP administration reduced depression-like behaviors in CUMS mice. Transcriptome sequencing was conducted in three control and three CUMS mice. Differentially expressed circRNAs, lncRNAs and mRNAs were then screened by bioinformatics analyses. Intersection analysis of the transcriptome sequencing results with the bioinformatics analysis results was followed to identify the candidate targets. We found that Gata2 alleviated depression-like behaviors via the metabolism- and synapse-related pathways. Gata2 was a target of miR-25-3p, which had binding sites to circ_0008405 and Oip5os1. circ_0008405 and Oip5os1 competitively bound to miR-25-3p to release the expression of Gata2. GP administration ameliorated depression-like behaviors in CUMS mice through regulation of the circ_0008405/miR-25-3p/Gata2 and Oip5os1/miR-25-3p/Gata2 crosstalk networks. Taken together, GP may exert a potential antidepressant-like effect on CUMS mice, which is ascribed to regulation of the circ_0008405/miR-25-3p/Gata2 and Oip5os1/miR-25-3p/Gata2 crosstalk networks.

The SIK1/CRTC2/CREB1 and TWIST1/PI3K/Akt/GSK3β signaling pathways mediated by microRNA-25-3p are altered in the schizophrenic rat brain

Schizophrenia is a group of severe mental disorders. MiR-25-3p was shown to be involved in various neuropsychiatric diseases and can regulate SIK1 and TWIST1. The CRTC2/CREB1 and PI3K/Akt/GSK3β signaling pathways are downstream pathways of SIK1 and TWIST1, respectively. This study investigated whether miR-25-3p-mediated SIK1/CRTC2/CREB1 and TWIST1/PI3K/Akt/GSK3β signaling pathways are present in an animal model relevant to schizophrenia. A schizophrenic rat model was established by using sub-chronic MK-801 administration. An RNA-seq test was performed to examine the differentially expressed genes (DEGs) in the rat prefrontal cortex (PFC). The mRNA levels of miR-25-3p, SIK1, and TWIST in the PFC and caudate putamen (CPu) were assessed by qRT-PCR. Phosphorylation of the SIK1/CRTC2/CREB1 and TWIST1/PI3K/Akt/GSK3β pathways in the two brain regions was examined by Western blots. The RNA-seq data revealed down-regulated miR-25-3p expression and up-regulated SIK1 and TWIST1 mRNA expression induced by MK-801. Additionally, SIK1 and TWIST1 were shown to be possible downstream responders of miR-25-3p in previous studies. qRT-PCR confirmed the changes of miR-25-3p, SIK1, and TWIST1 induced by MK-801 in both brain regions, which, however, was reversed by risperidone. Furthermore, the phosphorylation of the SIK1/CRTC2/CREB1 pathway was repressed by MK-801, whereas the phosphorylation of the TWIST1/PI3K/Akt/GSK3β pathway was increased by MK-801 in either of the two brain regions. Moreover, the altered phosphorylation of these two signaling pathways induced by MK-801 can be restored by risperidone. In conclusion, this study suggests that altered SIK1/CRTC2/CREB1 and TWIST1/PI3K/Akt/GSK3β signaling pathways mediated by miR-25-3p is very likely to be associated with schizophrenia, revealing potential targets for the treatment and clinical diagnosis of schizophrenia.

circ-CCND1 regulates the CCND1/P53/P21 pathway through sponging miR-138-5p in valve interstitial cells to aggravate aortic valve calcification

To discuss the effect and mechanism of circular-CCND1 (circ-CCND1) on the regulation of calcified aortic valve disease (CAVD). Differentially expressed circRNAs were screened through the GSE155119 data set and biological prediction. Subsequently, the miR-138-5p, CCND1, and circ-CCND1 expression were detected in the non-calcified and calcified aortic valve. Then Pearson correlation analysis was performed to analyze the correlation between the above expression, and dual luciferase and RNA-pull down assays for verifying the target relationship. Porcine aortic valve interstitial cells (AVICs) were isolated and transfected with pcDNA-circ-CCND1, miR-138-5p inhibitor, and miR-138-5p mimics. The alkaline phosphatase (ALP) activity was quantitatively analyzed by ALP staining, and alizarin-red staining was to check the calcium nodules formation. Finally, Western blot was applied to detect the expression of proteins associated with osteogenic differentiation (Runx2, Osterix, OPN) and CCND1/P53/P21 pathway proteins. Circ-CCND1 was highly expressed in calcific aortic valves. After inhibiting circ-CCND1 expression, a significant reduction was shown in ALP activity, the degree of ossification and the formation of calcium nodules in AVICs, and osteogenic differentiation-related protein expression and CCND1/P53/P21 pathway protein expression. By contrast, inhibition of miR-138-5p and circ-CCND1 together promoted the calcification of AVICs and expression of CCND1/P53/P21 pathway proteins. P53 inhibitor (PFT-α) could significantly reduce activation of CCND1/P53/P21 pathway protein expression by circ-CCND1 overexpression. However, P53 activator (Nutlin-3) significantly restored the suppression of the above pathway-related protein expression by downregulation of circ-CCND1. Circ-CCND1 sponges miR-138-5p to regulate CCND1 expression, thereby promoting the calcification of AVICs.

microRNA-25-3p suppresses osteogenic differentiation of BMSCs in patients with osteoporosis by targeting ITGB3

This study was conducted to investigate the impact of the microRNA (miR)-25-3p/ITGB3 axis on the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) from patients with osteoporosis (OP). BMSCs isolated from the bone marrow of healthy controls and OP patients were identified by flow cytometry, in which ITGB3 mRNA and miR-25-3p expression was detected by RT-qPCR and ITGB3, Runx2, OPN, ALP, and OSX protein expression by western blot. The binding between ITGB3 and miR-25-3p was assessed by dual-luciferase reporter gene and Ago2-RIP assays. BMSC osteogenic differentiation was observed by alizarin red staining and ALP activity. The differentiation of BMSCs to adipocytes and chondrocytes was measured by oil red O staining and alcian blue staining, respectively. BMSCs were successfully isolated from the bone marrow of healthy controls (normal-BMSCs) and OP patients (OP-BMSCs). ITGB3, Runx2, OPN, ALP, and OSX expression was poorer and miR-25-3p expression was higher in OP-BMSCs than in normal-BMSCs. Mechanistically, ITGB3 was negatively targeted by miR-25-3p. After osteogenic, adipogenic, and chondrogenic differentiation of BMSCs were successfully induced, adipogenic differentiation increased and osteogenic and chondrogenic differentiation decreased in OP-BMSCs compared with normal-BMSCs. Overexpression of ITGB3 facilitated mineralized nodule formation and elevated ALP activity and Runx2, OPN, and ALP expression in OP-BMSCs. miR-25-3p upregulation diminished mineralized nodule formation, ALP activity, and Runx2, OPN, and ALP expression in OP-BMSCs and normal-BMSCs, which was annulled by additional ITGB3 overexpression. miR-25-3p targets ITGB3, thereby suppressing osteogenic differentiation of BMSCs from OP patients.

Epigenetic regulation in cardiovascular disease: mechanisms and advances in clinical trials

Epigenetics is closely related to cardiovascular diseases. Genome-wide linkage and association analyses and candidate gene approaches illustrate the multigenic complexity of cardiovascular disease. Several epigenetic mechanisms, such as DNA methylation, histone modification, and noncoding RNA, which are of importance for cardiovascular disease development and regression. Targeting epigenetic key enzymes, especially the DNA methyltransferases, histone methyltransferases, histone acetylases, histone deacetylases and their regulated target genes, could represent an attractive new route for the diagnosis and treatment of cardiovascular diseases. Herein, we summarize the knowledge on epigenetic history and essential regulatory mechanisms in cardiovascular diseases. Furthermore, we discuss the preclinical studies and drugs that are targeted these epigenetic key enzymes for cardiovascular diseases therapy. Finally, we conclude the clinical trials that are going to target some of these processes.

Immunomodulatory Properties of Human Breast Milk: MicroRNA Contents and Potential Epigenetic Effects

Infants who are exclusively breastfed in the first six months of age receive adequate nutrients, achieving optimal immune protection and growth. In addition to the known nutritional components of human breast milk (HBM), i.e., water, carbohydrates, fats and proteins, it is also a rich source of microRNAs, which impact epigenetic mechanisms. This comprehensive work presents an up-to-date overview of the immunomodulatory constituents of HBM, highlighting its content of circulating microRNAs. The epigenetic effects of HBM are discussed, especially those regulated by miRNAs. HBM contains more than 1400 microRNAs. The majority of these microRNAs originate from the lactating gland and are based on the remodeling of cells in the gland during breastfeeding. These miRNAs can affect epigenetic patterns by several mechanisms, including DNA methylation, histone modifications and RNA regulation, which could ultimately result in alterations in gene expressions. Therefore, the unique microRNA profile of HBM, including exosomal microRNAs, is implicated in the regulation of the genes responsible for a variety of immunological and physiological functions, such as FTO, INS, IGF1, NRF2, GLUT1 and FOXP3 genes. Hence, studying the HBM miRNA composition is important for improving the nutritional approaches for pregnancy and infant's early life and preventing diseases that could occur in the future. Interestingly, the composition of miRNAs in HBM is affected by multiple factors, including diet, environmental and genetic factors.

Emerging Roles of Extracellular Vesicle-Delivered Circular RNAs in Atherosclerosis

Atherosclerosis (AS) is universally defined as chronic vascular inflammation induced by dyslipidaemia, obesity, hypertension, diabetes and other risk factors. Extracellular vesicles as information transmitters regulate intracellular interactions and their important cargo circular RNAs are involved in the pathological process of AS. In this review, we summarize the current data to elucidate the emerging roles of extracellular vesicle-derived circular RNAs (EV-circRNAs) in AS and the mechanism by which EV-circRNAs affect the development of AS. Additionally, we discuss their vital role in the progression from risk factors to AS and highlight their great potential for use as diagnostic biomarkers of and novel therapeutic strategies for AS.

circ-Iqsec1 induces bone marrow-derived mesenchymal stem cell (BMSC) osteogenic differentiation through the miR-187-3p/Satb2 signaling pathway

BACKGROUND

Bone marrow-derived mesenchymal stem cells (BMSCs) are general progenitor cells of osteoblasts and adipocytes and they are characterized as a fundamental mediator for bone formation. The current research studied the molecular mechanisms underlying circRNA-regulated BMSC osteogenic differentiation.

METHODS

Next-generation sequencing (NGS) was employed to study abnormal circRNA and mRNA expression in BMSCs before and after osteogenic differentiation induction. Bioinformatics analysis and luciferase reporting analysis were employed to confirm correlations among miRNA, circRNA, and mRNA. RT-qPCR, ALP staining, and alizarin red staining illustrated the osteogenic differentiation ability of BMSCs.

RESULTS

Data showed that circ-Iqsec1 expression increased during BMSC osteogenic differentiation. circ-Iqsec1 downregulation reduced BMSC osteogenic differentiation ability. The present investigation discovered that Satb2 played a role during BMSC osteogenic differentiation. Satb2 downregulation decreased BMSC osteogenic differentiation ability. Bioinformatics and luciferase data showed that miR-187-3p linked circ-Iqsec1 and Satb2. miR-187-3p downregulation or Satb2 overexpression restored the osteogenic differentiation capability of BMSCs post silencing circ-Iqsec1 in in vivo and in vitro experiments. Satb2 upregulation restored osteogenic differentiation capability of BMSCs post miR-187-3p overexpression.

CONCLUSION

Taken together, our study found that circ-Iqsec1 induced BMSC osteogenic differentiation through the miR-187-3p/Satb2 signaling pathway.

Hsa_circ_0000437 upregulates and promotes disease progression in rheumatic valvular heart disease

Background

Currently, the diagnosis and outcome of rheumatic valvular heart disease (RVHD) are less than ideal, and there are no accurate biomarkers. Circular RNA (circRNA) might participate in the occurrence and development of RVHD.

Materials and methods

We use circRNA microarray to filter out the target has_circ_0000437. qRT‐PCR was used to measure the expression levels of hsa_circ_0000437 in RVHD plasma samples. We assessed the diagnostic value of hsa_circ_0000437 in RVHD. Cell function in vitro experiment was to explore the effect of has_circ_0000437 on RVHD.

Results

Has_circ_0000437 is highly expressed in RVHD (p < 0.001). has_circ_0000437 has the diagnostic value in RVHD. In RVHD, hsa_circ_0000437 can promote cell proliferation and migration but inhibits its apoptosis. This may be due to the combination of has_circ_0000437 and target miRNA in the cytoplasm that affects the progress of RVHD.

Conclusions

Has_circ_0000437 can promote the process of RVHD and may be a potential for the diagnosis and treatment of RVHD.