MiR-199a-5p promotes migration and tube formation of human cytomegalovirus-infected endothelial cells through downregulation of SIRT1 and eNOS

miR-199a-5p modulates choroidal neovascularization by regulating Wnt7b/Wnt/β-catenin signaling pathway

Choroidal neovascularization (CNV) can be seen in many fundus diseases, and lead to fundus exudation, bleeding, or vision loss. miRNAs are vital regulator in CNV. miR-199a-5p has been proved to be involved in regulating vascular formation of endothelial cells, but its role in CNV remains unclear. This study aims to study the role of miR-199a-5p in CNV. Laser irradiation was used to induce CNV model. The lesion area of CNV was calculated by high-resolution angiography with fluorescein isothiocyanate-dextran. Wnt family member 7b (Wnt7b), β-catenin, and Wnt pathway proteins was measured by western blot. Immunofluorescence was performed to test Wnt7b, β-catenin, CD31, and p-p65. miR-199a-5p and Wnt7b mRNA were tested by reverse transcription real-time polymerase chain reaction. Cell count kit-8, wound healing, Transwell, tube formation, and flow cytometry were used to detect the function of miR-199a-5p and Wnt7b on human retinal microvascular endothelial cells (HRMEC). TargetScan database and dual-luciferase reporter assay verified the interaction between miR-199a-5p and Wnt7b. The results revealed that Wnt7b increased in CNV rats. Knocking down Wnt7b repressed cell proliferation, migration, invasion, and angiogenesis, and accelerated cell apoptosis of HRMEC. Dual-luciferase reporter assay verified that miR-199a-5p targeted Wnt7b. Overexpression of miR-199a-5p inhibited the angiogenesis of HRMEC and promoted cell apoptosis by inhibiting Wbt7b. In vivo experiment found that Wnt7b rescued the promotion of miR-199a-5p inhibition on CNV lesion of rats. In addition, Wnt7b positively regulated Wnt/β-catenin signaling pathway and promoted the angiogenesis of HRMEC. In conclusion, overexpression of miR-199a-5p inhibited the angiogenesis of HRMEC by regulating Wnt7b/Wnt/β-catenin signaling pathway, which may serve as a promising therapy target of CNV.

Atherosclerosis-associated endothelial dysfunction is promoted by miR-199a-5p/SIRT1 axis regulated by circHIF1ɑ

BACKGROUND AND AIMS

Atherosclerosis (AS) is a chronic inflammatory disease that damages the arterial wall as a result of hyperlipidemia and causes endothelial cell dysfunction, which increases the risk of atherothrombotic events. Multiple pathological conditions have shown ectopic miR-199a-5p levels to cause endothelial injury, but its role in the AS competitive endogenous RNA (CeRNA) network is still unknown.

METHODS AND RESULTS

The high-fat diet (HFD) apoE-/- mouse model was constructed in vivo, and ECs were cultured under ox-LDL treatment to induce EC injury in vitro. Immunohistochemistry and immunofluorescence staining were used to assess the effect of miR-199a-5p on the macrophage, SMC, collagen content, and endothelial coverage in the artery wall of mouse model. miR-199a-5p level was validated to be overexpression in the aorta tissue of HFD apoE-/- mice and in the ox-LDL-treated ECs, and even in the plasma EVs of the patients with cerebral AS. Silencing of miR-199a-5p significantly attenuated atherosclerotic progress in HFD apoE-/- mice, and the gain/loss-of-function assay indicated that miR-199a-5p overexpression aggravated ox-LDL-induced disabilities of endothelial proliferation, motility, and neovascularization based on cell counting kit-8 assay, transwell assay and matrigel assay. Mechanistically, miR-199a-5p prevented EC activation by activating the FOXO signaling pathway by targeting SIRT1. Additionally, circular RNA (circRNA) circHIF1ɑ was identified as having a low expression in the ox-LDL-treated EC and mediated SIRT1 expression via sponging miR-199a-5p to rescue ox-LDL-induced EC injury.

CONCLUSIONS

Our study demonstrated the vital role of miR-199a-5p/SIRT1 axis regulated by circHIF1ɑ in AS pathogenesis and provided novel effective targets for AS treatment.

Human Cytomegalovirus Induced Aberrant Expression of Non-coding RNAs

Human cytomegalovirus (HCMV) is a β-herpesvirus whose genome consists of double stranded linear DNA. HCMV genome can generate non-coding RNAs (ncRNAs) through transcription in its host cells. Besides that, HCMV infection also changes the ncRNAs expression profile of the host cells. ncRNAs play a key role in maintaining the normal physiological activity of cells, and the disorder of ncRNAs expression has numerous adverse effects on cells. However, until now, the relationship between ncRNAs and HCMV-induced adverse effects are not summarized in detail. This review aims to give a systematic summary of the role of HCMV infection in ncRNAs expression while providing insights into the molecular mechanism of unnormal cellular events caused by ncRNAs disorder. ncRNAs disorder induced by HCMV infection is highly associated with cell proliferation, apoptosis, tumorigenesis, and immune regulation, as well as the development of cardiovascular diseases, and the potential role of biomarker. We summarize the studies on HCMV associated ncRNAs disorder and suggest innovative strategies for eliminating the adverse effects caused by HCMV infection.

The Basis and Advances in Clinical Application of Cytomegalovirus-Specific Cytotoxic T Cell Immunotherapy for Glioblastoma Multiforme

A high percentage of malignant gliomas are infected by human cytomegalovirus (HCMV), and the endogenous expression of HCMV genes and their products are found in these tumors. HCMV antigen expression and its implications in gliomagenesis have emerged as a promising target for adoptive cellular immunotherapy (ACT) strategies in glioblastoma multiforme (GB) patients. Since antigen-specific T cells in the tumor microenvironments lack efficient anti-tumor immune response due to the immunosuppressive nature of glioblastoma, CMV-specific ACT relies on in vitro expansion of CMV-specific CD8+ T cells employing immunodominant HCMV antigens. Given the fact that several hurdles remain to be conquered, recent clinical trials have outlined the feasibility of CMV-specific ACT prior to tumor recurrence with minimal adverse effects and a substantial improvement in median overall survival and progression-free survival. This review discusses the role of HCMV in gliomagenesis, disease prognosis, and recent breakthroughs in harnessing HCMV-induced immunogenicity in the GB tumor microenvironment to develop effective CMV-specific ACT.

Regulation of miRNAs by Natural Antioxidants in Cardiovascular Diseases: Focus on SIRT1 and eNOS

Cardiovascular diseases (CVDs) are the most common cause of morbidity and mortality worldwide. The potential benefits of natural antioxidants derived from supplemental nutrients against CVDs are well known. Remarkably, natural antioxidants exert cardioprotective effects by reducing oxidative stress, increasing vasodilation, and normalizing endothelial dysfunction. Recently, considerable evidence has highlighted an important role played by the synergistic interaction between endothelial nitric oxide synthase (eNOS) and sirtuin 1 (SIRT1) in the maintenance of endothelial function. To provide a new perspective on the role of natural antioxidants against CVDs, we focused on microRNAs (miRNAs), which are important posttranscriptional modulators in human diseases. Several miRNAs are regulated via the consumption of natural antioxidants and are related to the regulation of oxidative stress by targeting eNOS and/or SIRT1. In this review, we have discussed the specific molecular regulation of eNOS/SIRT1-related endothelial dysfunction and its contribution to CVD pathologies; furthermore, we selected nine different miRNAs that target the expression of eNOS and SIRT1 in CVDs. Additionally, we have summarized the alteration of miRNA expression and regulation of activities of miRNA through natural antioxidant consumption.

Calcium dobesilate mediates renal interstitial fibrosis and delay renal peritubular capillary loss through Sirt1/p53 signaling pathway

Calcium dobesilate (Cad), a protective agent, protects against microvascular damage, and diseases such as diabetic retinopathy and diabetic nephropathy. However, these vascular protective effects have not been demonstrated in chronic kidney disease (CKD). In this study, we aimed to determine the ability of Cad to protect against renal interstitial fibrosis induced by unilateral ureteral obstruction (UUO) and identify the underlying therapeutic mechanisms of Cad during hypoxia/serum deprivation (H/SD) in human umbilical vein endothelial cells (HUVECs). A total of 36 male mice were randomly assigned into 3 groups (12 mice in each group): the Sham-operated group (Sham), the saline solution-treated UUO mice group (UUO), and the Cad administration (intragastrically) group (Cad). The mice in Cad group were administered Cad (100 mg/kg) daily by oral gavage and slaughtered on the 7th and 14th days post-surgery. Six mice from each group were sacrificed by sodium pentobarbital injection on the 7th and 14th day after surgery. Tissue hypoxia, cell apoptosis and fibrotic lesions were detected by Immunostaining and Western blot. Peritubular capillaries (PTCs) injury was measured by a novel technique of fluorescent microangiography (FMA). Endothelial cell-to-mesenchymal transition (EndMT) were identified by immunofluorescence and Western blot. HUVECs proliferation was measured via Cell Counting Kit‑8 assays and Edu staining. Sirt1 and its downstream gene in Cad regulation of endothelial were detected. Hematoxylin-eosin (HE), Masson-trichrome stains and Histological findings showed that Cad administration markedly reduced hypoxia and renal interstitial fibrosis at each time point in UUO. Meanwhile, Cad protect against EndMT process of PTCs by increasing CD31 expression and decreasing α-smooth muscle actin and fibronectin expression. in vitro studies showed that there was a proliferative response of the HUVECs incubated with Cad (10 μM) in H/SD. Sirt1 was suppressed after small interfering RNA (siRNA) was transfected in HUVECs. Mechanistically, Cad enhanced Sirt1 signaling, which was accompanied by increased levels of p53 acetylation (ac-p53). Meanwhile, protein expression of Bcl-2, and VE-cadherin were downregulated, Bax, and α-SMA were upregulated. In summary, the therapeutic effect of Cad in obstructive nephropathy were likely through suppressing EndMT progression and promoting anti-apoptotic effects after via activating the Sirt1/p53 signaling pathway.

Exosomes derived from GDNF-modified human adipose mesenchymal stem cells ameliorate peritubular capillary loss in tubulointerstitial fibrosis by activating the SIRT1/eNOS signaling pathway

Mesenchymal stem cells (MSCs) have emerged as ideal cell-based therapeutic candidates for the structural and functional restoration of the diseased kidney. Glial cell line-derived neurotrophic factor (GDNF) has been demonstrated to promote the therapeutic effect of MSCs on ameliorating renal injury. The mechanism may involve the transfer of endogenous molecules via paracrine factors to salvage injured cells, but these factors remain unknown.

Methods: GDNF was transfected into human adipose mesenchymal stem cells via a lentiviral transfection system, and exosomes were isolated (GDNF-AMSC-exos). Using the unilateral ureteral obstruction (UUO) mouse model and human umbilical vein endothelial cells (HUVECs) against hypoxia/serum deprivation (H/SD) injury models, we investigated whether GDNF-AMSC-exos ameliorate peritubular capillary (PTC) loss in tubulointerstitial fibrosis and whether this effect is mediated by the Sirtuin 1 (SIRT1) signaling pathway. Additionally, by using SIRT1 activators or siRNAs, the roles of the candidate mRNA and its downstream gene in GDNF-AMSC-exo-induced regulation of endothelial cell function were assessed. PTC characteristics were detected by fluorescent microangiography (FMA) and analyzed by the MATLAB software.

Results: The green fluorescent PKH67-labeled exosomes were visualized in the UUO kidneys and colocalized with CD81. GDNF-AMSC-exos significantly decreased PTC rarefaction and renal fibrosis scores in mice with UUO. In vitro studies revealed that GDNF-AMSC-exos exerted cytoprotective effects on HUVECs against H/SD injury by stimulating migration and angiogenesis as well as conferring apoptosis resistance. Mechanistically, GDNF-AMSC-exos enhanced SIRT1 signaling, which was accompanied by increased levels of phosphorylated endothelial nitric oxide synthase (p-eNOS). We also confirmed the SIRT1-eNOS interaction in HUVECs by immunoprecipitation. Furthermore, we observed a correlation of the PTC number with the SIRT1 expression level in the kidney in vivo.

Conclusion: Our study unveiled a mechanism by which exosomes ameliorate renal fibrosis: GDNF-AMSC-exos may activate an angiogenesis program in surviving PTCs after injury by activating the SIRT1/eNOS signaling pathway.

MicroRNA-199a-3p inhibits angiogenesis by targeting the VEGF/PI3K/AKT signalling pathway in an in vitro model of diabetic retinopathy

BACKGROUND

Diabetic retinopathy (DR) is a major inducer of blindness and visual impairment. As a critical cause for DR, hyperglycaemia is able to trigger multiple biochemical alterations. MiRNAs, which contain various functions, can effectively regulate blood glucose levels. This research aims to confirm the roles of miRNA-199a-3p in the progression of angiogenesis in an in vitro model of DR.

METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) was carried to determine the expression levels of miR-199a-3p and VEGF in both hRMECs and APRE-19 cells. The luciferase reporter assay was used to study the interaction between miR-199a-3p and VEGF. Western blot assay was conducted to examine the expression levels of VEGF and the PI3K/AKT signalling pathway. The cell proliferation capacity was detected via the CCK-8 test. The impact of miR-199a-3p on migration was determined using Transwell and wound healing assays. A Matrigel tube formation assay was employed to determine the vascular formation of hRMECs. Flow cytometry was used to determine cell apoptosis in the presence of LY294002 as a PI3K inhibitor.

RESULTS

Our results showed that high glucose (HG) decreased the relative expression level of miR-199a-3p but increased VEGF expression in hRMECs and APRE-19 cells. MiR-199a-3p inhibitor augmented cell growth, migration and angiogenesis of hRMECs. Moreover, upregulation of miR-199a-3p evidently alleviated the increases in cell proliferation, migration and angiogenesis caused by HG. In addition, the luciferase reporter assay indicated that miR-199a-3p directly targeted VEGF. The overexpression of miR-199a-3p obviously restrained the HG-stimulated PI3K/AKT signalling pathway and angiogenesis, which could be further inhibited by LY294002. Moreover, LY294002 could slightly ameliorate the miR-199a-3p inhibitor-stimulated PI3K/AKT signalling pathway and angiogenesis.

CONCLUSION

MiR-199a-3p upregulation ameliorated HG-stimulated angiogenesis of hRMECs by modulating the PI3K/AKT pathway through inhibiting VEGF. Although retinal neovascularization in vivo has not been studied, these in vitro findings provide more evidence for the role of miR-199a-3p upregulation against HG-induced angiogenesis.

Curcumin inhibits the formation of atherosclerosis in ApoE-/- mice by suppressing cytomegalovirus activity in endothelial cells

BACKGROUND

Curcumin (Cur) is a hydrophobic polyphenol compound derived from the rhizome of the herb Curcuma longa. Cur has a wide spectrum of biological and pharmacological activities. It has been shown that human cytomegalovirus (HCMV) infection was an important risk factor for atherosclerosis (AS) and Cur exhibited an outstanding anti-HCMV effect. However, anti-AS effects of Cur remain unclear when HCMV infected endothelial cells.

AIMS

This study will investigate the anti-AS activities and mechanism of Cur,when HCMV infected in vivo and in vitro.

MATERIALS AND METHODS

Cur (0.5, 1, and 2 μM) was used to explore the anti-AS activities and mechanism after HCMV infected endothelial cells in vitro. ApoE^-/- mice were fed a high fat and cholesterol diet (HD) and given 4000,000 copies/mouse MCMV infection by intraperitoneal and treated with ganciclovir (5 mg/kg/d), Cur (25, 15 mg/kg/d) for 10 weeks in vivo.

KEY FINDINGS

As our results showed that Cur inhibited CMV replication and proliferation, reduced the intracellular ROS overproduction, decreased the release of inflammatory cytokines, down-regulated the level of HMGB1-TLRS-NF-κB signaling pathway-related proteins in vitro experiments. Cur reduced the serum levels of LDL-C, TC and TG, significantly decreased the formation of atherosclerotic plaque in the aorta, reduced the lipid deposition in liver and inflammatory damage in heart, lung and kidney in vivo experiments.

SIGNIFICANCE

This study showed that Cur prevent AS progression by inhibiting CMV activity and CMV-induced HMGB1-TLRS-NF-κB signaling pathway.

Human cytomegalovirus infection is correlated with atherosclerotic plaque vulnerability in carotid artery

BACKGROUND

Several studies have suggested that human cytomegalovirus (CMV) infection is closely related to the pathogenesis of atherosclerosis. The present study aimed to investigate the association between human CMV infection and carotid atherosclerotic plaque vulnerability in a Chinese population.

METHODS

In total, 42 patients with carotid atherosclerosis (observation group) and 30 healthy volunteers (control group) were recruited in our study from October 2016 to January 2018. Statistical analysis was carried out to calculate the infection rate of CMV in subjects. Spearman's rank analysis was performed to evaluate the correlation between CMV infection and atherosclerotic plaque vulnerability.

RESULTS

The positive rate of CMV was significantly higher in the observation group compared to the control group, and matrix metalloproteinase 9 (MMP-9), tumor necrosis factor-α (TNF-α) and lectin-like oxidized low density lipoprotein receptor-1 (LOX-1) expression levels were also elevated in the observation group compared to those in the control group. In carotid atherosclerotic patients, the detection rate of unstable plaques and the Crouse scores in vulnerable plaque were significantly higher in the CMV-positive group compared to those in the CMV-negative group. As revealed by correlation analysis, CMV infection was significantly positively correlated with plaque vulnerability and expression levels of MMP-9, TNF-α and LOX-1 in carotid atherosclerotic patients.

CONCLUSIONS

Human CMV infection might be a potential risk factor for increased plaque vulnerability in patients with carotid atherosclerosis.

ROR2 suppresses metastasis of prostate cancer via regulation of miR-199a-5p-PIAS3-AKT2 signaling axis

Bones are the most common metastatic sites for prostate cancer (PCa). Receptor tyrosine kinase-like orphan receptor 2 (ROR2), a noncanonical Wnt receptor, plays crucial roles in skeletal morphogenesis, osteoblast differentiation, and bone formation. The role of ROR2 in PCa metastasis is unclear. We analyzed online datasets from Oncomine as well as using IHC staining on tissue array to determine the relationship between ROR2 expression level and disease outcome of PCa. To investigate how ROR2 regulates migration and invasion of PCa cells, we performed transwell assay and orthotopic xenograft model in nude mice. We then applied the Micro-Western Array (MWA), a high-throughput western blotting platform to analyze the downstream signaling pathways being regulated by ROR2. Compared with nonmalignant PZ-HPV-7 and RWPE-1 cells, PCa cell lines express lower level of ROR2 protein. Constitutive expression of ROR2 in PC-3, DU-145, or C4-2B PCa cells significantly suppressed the cell migration, invasion, and epithelial-mesenchymal transition (EMT) proteins. MWA, western blotting, and microRNA analysis showed that elevation of ROR2 suppressed the expression of miR-199a-5p, which in turn increased the expression of PIAS3. The upregulation of PIAS3 then decreased AKT2 and the phosphorylation of AKT, resulting in the inhibition of migration and invasion of PCa cells both in vitro and in orthotopic xenograft mice model. IHC staining of tissue array and Oncomine datasets analysis indicated that the gene and protein level of ROR2 is much lower in metastatic prostate tumors as compared with primary tumors or adjacent normal prostate tissues. Low level of ROR2 correlated to poor survival and high recurrent frequency in PCa patients. In conclusion, we discovered that ROR2 suppresses PCa metastasis via regulation of PIAS3-PI3K-AKT2 signaling axis.

The role of human cytomegalovirus in atherosclerosis: a systematic review

Atherosclerosis is a progressive vascular disease with increasing morbidity and mortality year by year in modern society. Human cytomegalovirus (HCMV) infection is closely associated with the development of atherosclerosis. HCMV infection may accelerate graft atherosclerosis and the development of transplant vasculopathy in organ transplantation. However, our current understanding of HCMV-associated atherosclerosis remains limited and is mainly based on clinical observations. The underlying mechanism of the involvement of HCMV infection in atherogenesis remains unclear. Here, we summarized current knowledge regarding the multiple influences of HCMV on a diverse range of infected cells, including vascular endothelial cells, vascular smooth muscle cells, monocytes, macrophages, and T cells. In addition, we described potential HCMV-induced molecular mechanisms, such as oxidative stress, endoplasmic reticulum stress, autophagy, lipid metabolism, and miRNA regulation, which are involved in the development of HCMV-associated atherogenesis. Gaining an improved understanding of these mechanisms will facilitate the development of novel and effective therapeutic strategies for the treatment of HCMV-related cardiovascular disease.

A pilot study of circulating microRNAs as potential biomarkers of Fabry disease

Patients suffering from Fabry disease (FD), a lysosomal storage disorder, show a broad range of symptoms and the diagnosis followed by the therapeutic decision remains a great challenge. The biomarkers available today have not proven to be useful for predicting the evolution of the disease and for assessing response to therapy in many patients. Here, we used high-throughput microRNA profiling methodology to identify a specific circulating microRNA profile in FD patients. We discovered a pattern of 10 microRNAs able to identify FD patients when compared to healthy controls. Notably, two of these: the miR199a-5p and the miR-126-3p are able to discriminate FDs from the control subjects with left ventricular hypertrophy, a frequent but non-specific FD symptom. These same microRNAs are also sensitive to enzyme replacement therapy showing variation in the subjects under treatment. Furthermore, two other microRNAs of the profile, the miR-423-5p and the miR-451a, seem useful to highlight cardiac involvement in FD patients. A literature and database search revealed that miR-199a-5p, miR-126-3p, miR-423-5p and miR-451a are known to be linked to pathological states that occur during the FD development. In particular, miR-199a-5p, and miR-126-3p are involved in endothelial dysfunction and miR-423-5p and miR-451a in myocardial remodeling. In conclusion, in this study we identified a common plasma microRNA profile in FD patients, useful not only for the correct classification of Fabry patients regardless of sex and age, but also to evaluate the response to therapy. Furthermore, our observations suggest that some microRNAs of this profile demonstrate prognostic qualities.

Deep Sequencing of Small RNAs in Blood of Patients with Brain Arteriovenous Malformations

BACKGROUND

Deregulation of circulating microRNAs (miRNAs) is always associated with development and progression of human diseases. We aimed to assess whether patients with brain arteriovenous malformations (BAVMs) possess a distinct miRNA signature compared with healthy subjects.

METHODS

Three patients with unruptured BAVMs and 3 normal control subjects were recruited as case and control groups. Peripheral blood was collected, and miRNA signature was obtained by next-generation sequencing, followed by comparative, functional, and network analyses. Quantitative reverse transcription polymerase chain reaction was performed to validate expression of specific miRNAs.

RESULTS

Deep sequencing detected 246 differentially expressed miRNAs in blood samples of patients with BAVMs compared with normal control subjects. For the top 5 miRNAs, 946 target genes were predicted, and a BAVM-specific miRNA-target gene regulatory network was constructed. Functional annotation suggested that 15 of the predicted miRNA-targeted genes were involved in vascular endothelial growth factor signaling, in which 3 critical miRNAs were involved: miR-7-5p, miR-199a-5p, and miR-200b-3p.

CONCLUSIONS

We explored the miRNA expression signature of BAVMs, which will provide an important foundation for future studies on the regulation of miRNAs involved in BAVMs.

NF-κB Activity Initiates Human ESC-Derived Neural Progenitor Cell Differentiation by Inducing a Metabolic Maturation Program

Human neural development begins at embryonic day 19 and marks the beginning of organogenesis. Neural stem cells in the neural tube undergo profound functional, morphological, and metabolic changes during neural specification, coordinated by a combination of exogenous and endogenous cues. The temporal cell signaling activities that mediate this process, during development and in the postnatal brain, are incompletely understood. We have applied gene expression studies and transcription factor-activated reporter lentiviruses during in vitro neural specification of human pluripotent stem cells. We show that nuclear factor κB orchestrates a multi-faceted metabolic program necessary for the maturation of neural progenitor cells during neurogenesis.

Plasma miR-199a-5p is increased in neutrophilic phenotype asthma patients and negatively correlated with pulmonary function

Objective

We investigated the relationship between plasma miRNAs levels and inflammatory characteristics in asthmatic patients.

Methods

Eligible adults with untreated asthma (n = 35) underwent a clinical assessment, sputum induction, and assessment of pulmonary function test and Asthma Control Test (ACT) scores. Asthma phenotypes were defined using the sputum cell count. miR-199a-5p expression was measured using quantitative real-time polymerase chain reaction (qPCR). Lipopolysaccharide (LPS) stimulation was used to detect miR-199a-5p secretion from peripheral blood-derived neutrophil, lymphocyte, macrophage and BEAS-2B cells. The correlation of miR-199a-5p expression with clinical parameters was analyzed using multiple linear regression analysis. In silico analysis predicted the target genes and signaling pathway of miR-199a-5p. Transfection of miR-199a-5p mimics in human airway smooth muscle cells (HASMCs) was performed in vitro.

Results

The miRNA-199a-5p levels in plasma and sputum increased significantly in patients with neutrophilic asthma compared to healthy subjects (ps = 0.014 and 0.006, respectively). Expression of miR-199a-5p in the plasma of asthmatic patients positively correlated with sputum miR-199a-5p expression (r = 0.511, p = 0.021). The miR-199a-5p level was only elevated with LPS stimulation in neutrophils but not macrophages, lymphocytes, or epithelial cells from healthy controls (p < 0.01). miR-199a-5p expression increased in response to LPS (p = 0.005) and LPS combined with IL-4 (p = 0.003), but not IL-4 alone. However, peripheral neutrophils from eosinophilic asthma patients did not respond to LPS with increased miR-199a-5p expression (n = 5, p > 0.05) in contrast to the significant response from neutrophilic patients (n = 4, p < 0.0001). miR-199a-5p negatively correlated with FEV_1, FVC and PEF (r = -0.377, p = 0.026; r = -0.419, p = 0.012; and r = -0.392, p = 0.024, respectively). Multivariate correlation analysis confirmed that the plasma miR-199a-5p levels negatively correlated with FEV₁ in patients with asthma (Adjusted R² = 0.164, p = 0.015). In silico analysis suggested that the WNT signaling pathway participates in miR-199a-5p mediation of smooth muscle cell hypertrophy. In vitro experiment, miR-199a-5p mimics inhibited the protein expressions of WNT2 and WNT4, decreased the c-myc expression and dramatically increased the Sm-MHC expression in HASMCs.

Conclusion

Plasma miR-199a-5p was increased in neutrophilic asthma and negatively correlated with pulmonary function, which suggests that miR-199a-5p actively contributes to disease pathogenesis by modulating the inflammatory process and transferring the signal from inflammatory cells to structure cells.

Who watches the watchmen? Regulation of the expression and activity of sirtuins

Sirtuins (SIRT1-7) are a family of nicotine adenine dinucleotide (NAD⁺)-dependent enzymes that catalyze post-translational modifications of proteins. Together, they regulate crucial cellular functions and are traditionally associated with aging and longevity. Dysregulation of sirtuins plays an important role in major diseases, including cancer and metabolic, cardiac, and neurodegerative diseases. They are extensively regulated in response to a wide range of stimuli, including nutritional and metabolic challenges, inflammatory signals or hypoxic and oxidative stress. Each sirtuin is regulated individually in a tissue- and cell-specific manner. The control of sirtuin expression involves all the major points of regulation, including transcriptional and post-translational mechanisms and microRNAs. Collectively, these mechanisms control the protein levels, localization, and enzymatic activity of sirtuins. In many cases, the regulators of sirtuin expression are also their substrates, which lead to formation of intricate regulatory networks and extensive feedback loops. In this review, we highlight the mechanisms mediating the physiologic and pathologic regulation of sirtuin expression and activity. We also discuss the consequences of this regulation on sirtuin function and cellular physiology.-Buler, M., Andersson, U., Hakkola, J. Who watches the watchmen? Regulation of the expression and activity of sirtuins.

Vascular microRNA-204 is remotely governed by the microbiome and impairs endothelium-dependent vasorelaxation by downregulating Sirtuin1

Gut microbiota promotes atherosclerosis, and vascular endothelial dysfunction, signalled by impaired endothelium-dependent vasorelaxation, is an early marker of atherosclerosis. Here we show that vascular microRNA-204 (miR-204) expression is remotely regulated by the microbiome, and impairs endothelial function by targeting the Sirtuin1 lysine deacetylase (Sirt1). MiR-204 is downregulated, while Sirt1 is upregulated, in aortas of germ-free mice. Suppression of gut microbiome with broad-spectrum antibiotics decreases miR-204, increases Sirt1 and bioavailable vascular nitric oxide, and improves endothelium-dependent vasorelaxation in mouse aortas. Antibiotics curtail aortic miR-204 upregulation, and rescue decline of aortic Sirt1 and endothelium-dependent vasorelaxation, triggered by high-fat diet feeding. Improvement of endothelium-dependent vasorelaxation by antibiotics is lost in mice lacking endothelial Sirt1. Systemic antagonism of miR-204 rescues impaired endothelium-dependent vasorelaxation and vascular Sirt1, and decreases vascular inflammation induced by high-fat diet. These findings reveal a gut microbe-vascular microRNA–Sirtuin1 nexus that leads to endothelial dysfunction.

Commensal bacteria, the vast majority of which reside in the gut, are involved in development of many diseases, including atherosclerotic vascular disease. Here the authors show that these bacteria remotely increase expression of vascular microRNA-204, which targets Sirt1 in the endothelium to impair endothelial function.

MiRNA-199a-5p influences pulmonary artery hypertension via downregulating Smad3

MicroRNAs (miRNAs) play important roles in pulmonary artery hypertension (PAH). Recently, it has been reported that miR-199a-5p participates in the progression of chronic obstructive pulmonary disease, ventricular hypertrophy and heart failure. However, the roles of miR-199a-5p in PAH are still unclear. In the present study, miR-199a-5p was investigated in PAH rat models and in human pulmonary artery smooth muscle cells (HPASMCs) and endothelial cells (HPAECs). The expression of miR-199a-5p was significantly increased following PAH induction, and anti-miR-199a-5p could increase the nitric oxide (NO) level and decrease the PAH-induced upregulation of pulmonary artery pressure and right ventricular hypertrophy. Moreover, in HPASMCs and HPAECs, miR-199a-5p overexpression could inhibit the level of NO and promote the concentration of Ca(2+), but anti-miR-199a-5p showed opposite results. Further analysis demonstrated that miR-199a-5p attenuated the expression of Smad3. Importantly, Smad3 was confirmed to be the target gene of miR-199a-5p using dual-luciferase reporter assay. Mechanism analyses revealed that the downregulation of NO and the upregulation of Ca(2+) caused by miR-199a-5p were all reversed by Smad3 overexpression in HPASMCs and HPAECs. Moreover, in PAH model, Smad3, p-Smad3 and Smad4 were all downregulated in lung tissues, and SIS3 (Smad3 inhibitor) could reverse the effects of anti-miR-199a-5p in PAH rats. Our date suggest that miR-199a-5p may function as a regulator of PAH by targeting Smad3, indicating a novel therapeutic strategy for patients with PAH.

microRNA deregulation in keloids: an opportunity for clinical intervention?

Keloids are defined as benign dermal scars invading adjacent healthy tissue, characterized by aberrant fibroblast dynamics and overproduction of extracellular matrix. However, the aetiology and molecular mechanism of keloid production remain poorly understood. Recent discoveries have shed new light on the involvement of a class of non-coding RNAs known as microRNAs (miRNA), in keloid formation. A number of miRNAs have differential expression in keloid tissues and keloid-derived fibroblasts. These miRNAs have been characterized as novel regulators of cellular processes pertinent to wound healing, including extracellular matrix deposition and fibroblast proliferation. Delineating the functional significance of miRNA deregulation may help us better understand pathogenesis of keloids, and promote development of miRNA-directed therapeutics against this condition.

MicroRNA expression in circulating microvesicles predicts cardiovascular events in patients with coronary artery disease

Background

Circulating microRNAs (miRNAs) are differentially regulated and selectively packaged in microvesicles (MVs). We evaluated whether circulating vascular and endothelial miRNAs in patients with stable coronary artery disease have prognostic value for the occurrence of cardiovascular (CV) events.

Methods and Results

Ten miRNAs involved in the regulation of vascular performance—miR‐126, miR‐222, miR‐let7d, miR‐21, miR‐20a, miR‐27a, miR‐92a, miR‐17, miR‐130, and miR‐199a—were quantified in plasma and circulating MVs by reverse transcription polymerase chain reaction in 181 patients with stable coronary artery disease. The median duration of follow‐up for major adverse CV event–free survival was 6.1 years (range: 6.0–6.4 years). Events occurred in 55 patients (31.3%). There was no significant association between CV events and plasma level of the selected miRNAs. In contrast, increased expression of miR‐126 and miR‐199a in circulating MVs was significantly associated with a lower major adverse CV event rate. In univariate analysis, above‐median levels of miR‐126 in circulating MVs were predictors of major adverse CV event–free survival (hazard ratio: 0.485 [95% CI: 0.278 to 0.846]; P=0.007) and percutaneous coronary interventions (hazard ratio: 0.458 [95% CI: 0.222 to 0.945]; P=0.03). Likewise, an increased level of miR‐199a in circulating MVs was associated with a reduced risk of major adverse CV events (hazard ratio: 0.518 [95% CI: 0.299 to 0.898]; P=0.01) and revascularization (hazard ratio: 0.439 [95% CI: 0.232 to 0.832]; P=0.01) in univariate analysis. miRNA expression analysis in plasma compartments revealed that miR‐126 and miR‐199a are present mainly in circulating MVs. MV‐sorting experiments showed that endothelial cells and platelets were found to be the major cell sources of MVs containing miR‐126 and miR‐199a, respectively.

Conclusion

MVs containing miR‐126 and miR‐199a but not freely circulating miRNA expression predict the occurrence of CV events in patients with stable coronary artery disease.

The use of microRNA by human viruses: lessons from NK cells and HCMV infection

Depending on ethnicity and on social conditions, between 40 and 90 % of the population is infected with human cytomegalovirus (HCMV). In immunocompetent patients, the virus may cause an acute disease and then revert to a state of latency, which enables its coexistence with the human host. However, in cases of immunosuppression or in neonatal infections, HCMV can cause serious long-lasting illnesses. HCMV has developed multiple mechanisms in order to escape its elimination by the immune system, specifically by two killer cell types of the adaptive and the innate immune systems; cytotoxic T lymphocytes (CTL) and natural killer (NK) cells, respectively. Another fascinating aspect of HCMV is that like other highly developed herpesviruses, it expresses its own unique set of microRNAs. Here, we initially describe how the activity of NK cells is regulated under normal conditions and during infection. Then, we discuss what is currently known about HCMV microRNA-mediated interactions, with special emphasis on immune modulation and NK cell evasion. We further illustrate the significant modulation of cellular microRNAs during HCMV infection. Although, the full target spectrum of HCMV microRNAs is far from being completely elucidated, it can already be concluded that HCMV uses its "multitasking" microRNAs to globally affect its own life cycle, as well as important cellular and immune-related pathways.

MicroRNA-217 promotes angiogenesis of human cytomegalovirus-infected endothelial cells through downregulation of SIRT1 and FOXO3A

Human cytomegalovirus(HCMV) infection has been shown to contribute to vascular disease through the induction of angiogenesis. However, the role of microRNA in angiogenesis induced by HCMV infection remains unclear. The present study was thus designed to explore the potential effect of miR-1217 on angiogenesis and to disclose the underlying mechanism in endothelial cells. We found that HCMV infection of endothelial cells(ECs) enhanced expression of miR-217 and reduced SIRT1 and FOXO3A protein level in 24 hours post infection(hpi). Transfection of miR-217 inhibitor not only depressed cellular migration and tube formation induced by HCMV infection, but also enhanced SIRT1 and FOXO3A protein expression. Additionally, luciferase assay confirmed that miR-217 directly targeted FOXO3A mRNA 3`UTR. Furthermore, pretreatment with resveratrol depressed motility and tube formation of HCMV-infected ECs, which could be reversed by SIRT1 siRNA. Similarly, delivery of FOXO3A overexpression lentivirus suppressed proliferative rate, migration and tube formation of HCMV-infected ECs, which reversed by transfection of FOXO3A siRNA. In summary, HCMV infection of endothelial cells induces angiogenesis by both of miR-217/SIRT1 and miR-217/FOXO3A axis.