Let-7d modulates the proliferation, migration, tubulogenesis of endothelial cells

Transcoronary Gradients of Mechanosensitive MicroRNAs as Predictors of Collateral Development in Chronic Total Occlusion

Background and Objectives: In this present study, we investigated the impact of mechanosensitive microRNAs (mechano-miRs) on the collateral development in 126 chronic total occlusion (CTO) patients, selected from 810 undergoing angiography. Materials and Methods: We quantified the collateral blood supply using the collateral flow index (CFI) and assessed the transcoronary mechano-miR gradients. Results: The patients with favorable collaterals had higher CFI values (0.45 ± 0.02) than those with poor collaterals (0.38 ± 0.03, p < 0.001). Significant differences in transcoronary gradients were found for miR-10a, miR-19a, miR-21, miR-23b, miR-26a, miR-92a, miR-126, miR-130a, miR-663, and let7d (p < 0.05). miR-26a and miR-21 showed strong positive correlations with the CFI (r = 0.715 and r = 0.663, respectively), while let7d and miR-663 were negatively correlated (r = -0.684 and r = -0.604, respectively). The correlations between cytokine gradients and mechano-miR gradients were also significant, including Transforming Growth Factor Beta with miR-126 (r = 0.673, p < 0.001) and Vascular Endothelial Growth Factor with miR-10a (r = 0.602, p = 0.002). A regression analysis highlighted the hemoglobin level, smoking, beta-blocker use, miR-26a, and miR-663 as significant CFI determinants, indicating their roles in modulating the collateral vessel development. Conclusions: These findings suggest mechanosensitive microRNAs as predictive biomarkers for collateral circulation, offering new therapeutic perspectives for CTO patients.

miR-328a-3p modulates the proliferative and migratory abilities of Schwann cells in peripheral nerves

MicroRNAs (miRNAs) modulate Schwann cell phenotype. Here miR-328a-3p amounts after peripheral nerve damage were determined in injury stumps of the sciatic nerve in rats administered surgical crush. Quantitative real-time reverse transcription-polymerase chain reaction was performed to assess miR-328a-3p levels 0, 1, 4, 7 and 14 days post-sciatic nerve damage. The results showed miR-328a-3p was upregulated after nerve damage. CCK8 and EdU assays revealed elevated miR-328a-3p amounts suppressed Schwann cell viability and proliferation, respectively. Next, the migratory potential of cells was assessed by the Transwell chamber and wound healing assays. We found elevated miR-328a-3p amounts also suppressed Schwann cell migration. Conversely, low miR-328a-3p amounts promoted Schwann cell migration. The possible miR-328a-3p targets were predicted by bioinformatics. The 15 target genes retrieved provided insights into miR-328a-3p's effects on Schwann cells and expanded the understanding of miR-328a-3p's biological functions in the peripheral nervous system. Collectively, these findings revealed miR-328a-3p's effects on Schwann cells and provided further insights into the functions of miRNAs in peripheral nerves.

miR-140-3p suppresses the proliferation and migration of macrophages

Macrophages benefit myelin debris removal, blood vessel formation, and Schwann cell activation following peripheral nerve injury. Identifying factors that modulate macrophage phenotype may advantage the repair and regeneration of injured peripheral nerves. microRNAs (miRNAs) are important regulators of many physiological and pathological processes, including peripheral nerve regeneration. Herein, we investigated the regulatory roles of miR-140-3p, a miRNA that was differentially expressed in injured rat sciatic nerves, in macrophage RAW264.7 cells. Observations from EdU proliferation assay demonstrated that elevated miR-140-3p decreased the proliferation rates of RAW264.7 cells while suppressed miR-140-3p increased the proliferation rates of RAW264.7 cells. Transwell-based migration assay showed that up-regulated and down-regulated miR-140-3p led to elevated and reduced migration abilities, respectively. However, the abundances of numerous phenotypic markers of M1 and M2 macrophages were not significantly altered by miR-140-3p mimic or inhibitor transfection. Bioinformatic analysis and miR-140-3p-induced gene suppression examination suggested that Smad3 might be the target gene of miR-140-3p. These findings illuminate the inhibitory effects of miR-140-3p on the proliferation and migration of macrophages and contribute to the cognition of the essential roles of miRNAs during peripheral nerve regeneration.

Cerebrovascular microRNA Expression Profile During Early Development of Alzheimer's Disease in a Mouse Model

BACKGROUND

Emerging evidence demonstrates association of Alzheimer's disease (AD) with impaired delivery of blood oxygen and nutrients to and throughout the brain. The cerebral circulation plays multiple roles underscoring optimal brain perfusion and cognition entailing moment-to-moment blood flow control, vascular permeability, and angiogenesis. With currently no effective treatment to prevent or delay the progression of AD, cerebrovascular microRNA (miRNA) markers corresponding to post-transcriptional regulation may distinguish phases of AD.

OBJECTIVE

We tested the hypothesis that cerebrovascular miRNA expression profiles indicate developmental stages of AD pathology.

METHODS

Total RNA was isolated from total brain vessel segments of male and female 3xTg-AD mice [young, 1-2 mo; cognitive impairment (CI), 4-5 mo; extracellular amyloid-β plaques (Aβ), 6-8 mo; plaques+neurofibrillary tangles (AβT), 12-15 mo]. NanoString technology nCounter miRNA Expression panel for mouse was used to screen for 599 miRNAs.

RESULTS

Significant (p < 0.05) downregulation of various miRNAs indicated transitions from young to CI (e.g., let-7g & miR-1944, males; miR-133a & miR-2140, females) and CI to Aβ (e.g., miR-99a, males) but not from Aβ to AβT. In addition, altered expression of select miRNAs from overall Pre-AD (young + CI) versus AD (Aβ+ AβT) were detected in both males (let-7d, let-7i, miR-23a, miR-34b-3p, miR-99a, miR-126-3p, miR-132, miR-150, miR-151-5p, miR-181a) and females (miR-150, miR-539). Altogether, at least 20 cerebrovascular miRNAs effectively delineate AD versus Pre-AD pathology.

CONCLUSION

Using the 3xTg-AD mouse model, these data demonstrate that cerebrovascular miRNAs pertaining to endothelial function, vascular permeability, angiogenesis, inflammation, and Aβ/tau metabolism can track early development of AD.

miR-328a-3p stimulates endothelial cell migration and tubulogenesis

Endothelial cells have important biological roles after peripheral nerve injury by forming blood vessels within the nerve gap and guiding Schwann cell migration. MicroRNAs (miRNAs/miRs) affect cellular behavior and regulate a wide variety of physiological and pathological activities, including peripheral nerve regeneration. Emerging studies have identified the essential roles of miRNAs in the phenotype modulation of Schwann cells, while the effects of miRNAs on endothelial cells have remained to be thoroughly investigated. miR-328a-3p was differentially expressed in peripheral nerve stumps after nerve injury. In the present study, the effects of miR-328a-3p on biological functions of endothelial cells were determined by transfecting cultured human umbilical vein endothelial cells (HUVECs) with miR-328a-3p mimics or inhibitor. Transfection with miR-328a-3p mimics led to slightly decreased HUVEC proliferation and robustly increased HUVEC migration and tubulogenesis, while transfection with miR-328a-3p inhibitor led to opposite results. Using bioinformatics analysis, potential regulators and effectors of miR-328a-3p were further discovered and a miR-328a-3p-centered competing endogenous RNA network was constructed. Collectively, the present study demonstrated that dysregulated miR-328a-3p after peripheral nerve injury may affect the migration and angiogenesis of endothelial cells and contribute to peripheral nerve regeneration.

Endothelial-derived cardiovascular disease-related microRNAs elevated with prolonged sitting pattern among postmenopausal women

Time spent sitting is positively correlated with endothelial dysfunction and cardiovascular disease risk. The underlying molecular mechanisms are unknown. MicroRNAs contained in extracellular vesicles (EVs) reflect cell/tissue status and mediate intercellular communication. We explored the association between sitting patterns and microRNAs isolated from endothelial cell (EC)-derived EVs. Using extant actigraphy based sitting behavior data on a cohort of 518 postmenopausal overweight/obese women, we grouped the woman as Interrupted Sitters (IS; N = 18) or Super Sitters (SS; N = 53) if they were in the shortest or longest sitting pattern quartile, respectively. The cargo microRNA in EC-EVs from the IS and SS women were compared. MicroRNA data were weighted by age, physical functioning, MVPA, device wear days, device wear time, waist circumference, and body mass index. Screening of CVD-related microRNAs demonstrated that miR-199a-5p, let-7d-5p, miR-140-5p, miR-142-3p, miR-133b level were significantly elevated in SS compared to IS groups. Group differences in let-7d-5p, miR-133b, and miR-142-3p were validated in expanded groups. Pathway enrichment analyses show that mucin-type O-glycan biosynthesis and cardiomyocyte adrenergic signaling (P < 0.001) are downstream of the three validated microRNAs. This proof-of-concept study supports the possibility that CVD-related microRNAs in EC-EVs may be molecular transducers of sitting pattern-associated CVD risk in overweight postmenopausal women.

Circ_0068087 Silencing Ameliorates Oxidized Low-Density Lipoprotein-Induced Dysfunction in Vascular Endothelial Cells Depending on miR-186-5p-Mediated Regulation of Roundabout Guidance Receptor 1

Background: Circular RNAs (circRNAs) are endogenous non-coding RNAs involved in the progression of atherosclerosis (AS). We investigated the role of circ_0068087 in AS progression and its associated mechanism.

Methods: The 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay, flow cytometry, and enzyme-linked immunosorbent assay (ELISA) were performed to analyze the viability, apoptosis, and inflammatory response of HUVECs, respectively. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and the Western blot assay were performed to measure the expression of RNA and protein. Cell oxidative stress was analyzed using commercial kits. The dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were conducted to verify the interaction between microRNA-186-5p (miR-186-5p) and circ_0068087 or roundabout guidance receptor 1 (ROBO1).

Results: Oxidized low-density lipoprotein (ox-LDL) exposure upregulated the circ_0068087 level in HUVECs. ox-LDL-induced dysfunction in HUVECs was largely attenuated by the silence of circ_0068087. Circ_0068087 negatively regulated the miR-186-5p level by interacting with it in HUVECs. Circ_0068087 knockdown restrained ox-LDL-induced injury in HUVECs partly by upregulating miR-186-5p. ROBO1 was a downstream target of miR-186-5p in HUVECs. Circ_0068087 positively regulated ROBO1 expression by sponging miR-186-5p in HUVECs. MiR-186-5p overexpression exerted a protective role in ox-LDL-induced HUVECs partly by downregulating ROBO1.

Conclusion: Circ_0068087 interference alleviated ox-LDL-induced dysfunction in HUVECs partly by reducing ROBO1 expression via upregulating miR-186-5p.

Intercellular Communication by Vascular Endothelial Cell-Derived Extracellular Vesicles and Their MicroRNAs in Respiratory Diseases

Respiratory diseases and their comorbidities, such as cardiovascular disease and muscle atrophy, have been increasing in the world. Extracellular vesicles (EVs), which include exosomes and microvesicles, are released from almost all cell types and play crucial roles in intercellular communication, both in the regulation of homeostasis and the pathogenesis of various diseases. Exosomes are of endosomal origin and range in size from 50 to 150 nm in diameter, while microvesicles are generated by the direct outward budding of the plasma membrane in size ranges of 100-2,000 nm in diameter. EVs can contain various proteins, metabolites, and nucleic acids, such as mRNA, non-coding RNA species, and DNA fragments. In addition, these nucleic acids in EVs can be functional in recipient cells through EV cargo. The endothelium is a distributed organ of considerable biological importance, and disrupted endothelial function is involved in the pathogenesis of respiratory diseases such as chronic obstructive pulmonary disease, pulmonary hypertension, and acute respiratory distress syndrome. Endothelial cell-derived EVs (EC-EVs) play crucial roles in both physiological and pathological conditions by traveling to distant sites through systemic circulation. This review summarizes the pathological roles of vascular microRNAs contained in EC-EVs in respiratory diseases, mainly focusing on chronic obstructive pulmonary disease, pulmonary hypertension, and acute respiratory distress syndrome. Furthermore, this review discusses the potential clinical usefulness of EC-EVs as therapeutic agents in respiratory diseases.

Transcriptomic analysis reveals essential microRNAs after peripheral nerve injury

Studies have shown that microRNAs (miRNAs) mediate posttranscriptional regulation of target genes and participate in various physiological and pathological processes, including peripheral nerve injury. However, it is hard to select key miRNAs with essential biological functions among a large number of differentially expressed miRNAs. Previously, we collected injured sciatic nerve stumps at multiple time points after nerve crush injury, examined gene changes at different stages (acute, sub-acute, and post-acute), and obtained mRNA expression profiles. Here, we jointly analyzed mRNAs and miRNAs, and investigated upstream miRNAs of differentially expressed mRNAs using Ingenuity Pathway Analysis bioinformatic software. A total of 31, 42, 30, and 23 upstream miRNAs were identified at 1, 4, 7, and 14 days after rat sciatic nerve injury, respectively. Temporal expression patterns and biological involvement of commonly involved upstream miRNAs (miR-21, let-7, miR-223, miR-10b, miR-132, miR-15b, miR-127, miR-29a, miR-29b, and miR-9) were then determined at multiple time points. Expression levels of miR-21, miR-132, miR-29a, and miR-29b were robustly increased after sciatic nerve injury. Biological processes involving these miRNAs include multicellular organismal response to stress, positive regulation of the epidermal growth factor receptor signaling pathway, negative regulation of epithelial cell differentiation, and regulation of myocardial tissue growth. Moreover, we constructed mechanistic networks of let-7, miR-21, and miR-223, the most significantly involved upstream miRNAs. Our findings reveal that multiple upstream miRNAs (i.e., let-7, miR-21, and miR-223) were associated with gene expression changes in rat sciatic nerve stumps after nerve injury, and these miRNAs play an important role in peripheral nerve regeneration. This study was approved by the Experimental Animal Ethics Committee of Jiangsu Province of China (approval No. 20190303-18) on March 3, 2019.

Inflammatory state of lymphatic vessels and miRNA profiles associated with relapse in ovarian cancer patients

Lymphogenic spread is associated with poor prognosis in epithelial ovarian cancer (EOC), yet little is known regarding roles of non-peri-tumoural lymphatic vessels (LVs) outside the tumour microenvironment that may impact relapse. The aim of this feasibility study was to assess whether inflammatory status of the LVs and/or changes in the miRNA profile of the LVs have potential prognostic and predictive value for overall outcome and risk of relapse. Samples of macroscopically normal human lymph LVs (n = 10) were isolated from the external iliac vessels draining the pelvic region of patients undergoing debulking surgery. This was followed by quantification of the inflammatory state (low, medium and high) and presence of cancer-infiltration of each LV using immunohistochemistry. LV miRNA expression profiling was also performed, and analysed in the context of high versus low inflammation, and cancer-infiltrated versus non-cancer-infiltrated. Results were correlated with clinical outcome data including relapse with an average follow-up time of 13.3 months. The presence of a high degree of inflammation correlated significantly with patient relapse (p = 0.033). Cancer-infiltrated LVs showed a moderate but non-significant association with relapse (p = 0.07). Differential miRNA profiles were identified in cancer-infiltrated LVs and those with high versus low inflammation. In particular, several members of the let-7 family were consistently down-regulated in highly inflamed LVs (>1.8-fold, p<0.05) compared to the less inflamed ones. Down-regulation of the let-7 family appears to be associated with inflammation, but whether inflammation contributes to or is an effect of cancer-infiltration requires further investigation.