A miRNA-101-3p/Bim axis as a determinant of serum deprivation-induced endothelial cell apoptosis

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.

A Newly Developed Chemically Defined Serum-Free Medium Suitable for Human Primary Keratinocyte Culture and Tissue Engineering Applications

In our experience, keratinocytes cultured in feeder-free conditions and in commercially available defined and serum-free media cannot be as efficiently massively expanded as their counterparts grown in conventional bovine serum-containing medium, nor can they properly form a stratified epidermis in a skin substitute model. We thus tested a new chemically defined serum-free medium, which we developed for massive human primary keratinocyte expansion and skin substitute production. Our medium, named Surge Serum-Free Medium (Surge SFM), was developed to be used alongside a feeder layer. It supports the growth of keratinocytes freshly isolated from a skin biopsy and cryopreserved primary keratinocytes in cultured monolayers over multiple passages. We also show that keratin-19-positive epithelial stem cells are retained through serial passaging in Surge SFM cultures. Transcriptomic analyses suggest that gene expression is similar between keratinocytes cultured with either Surge SFM or the conventional serum-containing medium. Additionally, Surge SFM can be used to produce bilayered self-assembled skin substitutes histologically similar to those produced using serum-containing medium. Furthermore, these substitutes were grafted onto athymic mice and persisted for up to six months. In conclusion, our new chemically defined serum-free keratinocyte culture medium shows great promise for basic research and clinical applications.

Non-coding RNAs in Kawasaki disease: Molecular mechanisms and clinical implications

Kawasaki disease (KD) is an acute self-limiting vasculitis with coronary complications, usually occurring in children. The incidence of KD in children is increasing year by year, mainly in East Asian countries, but relatively stably in Europe and America. Although studies on KD have been reported, the pathogenesis of KD is unknown. With the development of high-throughput sequencing technology, growing number of regulatory noncoding RNAs (ncRNAs) including microRNA (miRNA), long noncoding RNA (lncRNA), and circular RNA (circRNA) have been identified to involved in KD. However, the role of ncRNAs in KD has not been comprehensively elucidated. Therefore, it is significative to study the regulatory role of ncRNA in KD, which might help to uncover new and effective therapeutic strategies for KD. In this review, we summarize recent studies on ncRNA in KD from the perspectives of immune disorders, inflammatory disorders, and endothelial dysfunction, and highlight the potential of ncRNAs as therapeutic targets for KD.

MicroRNAs as Biomarkers for Ionizing Radiation Injury

Accidental radiation exposures such as industrial accidents and nuclear catastrophes pose a threat to human health, and the potential or substantial injury caused by ionizing radiation (IR) from medical treatment that cannot be ignored. Although the mechanisms of IR-induced damage to various organs have been gradually investigated, medical treatment of irradiated individuals is still based on clinical symptoms. Hence, minimally invasive biomarkers that can predict radiation damage are urgently needed for appropriate medical management after radiation exposure. In the field of radiation biomarker, finding molecular biomarkers to assess different levels of radiation damage is an important direction. In recent years, microRNAs have been widely reported as several diseases’ biomarkers, such as cancer and cardiovascular diseases, and microRNAs are also of interest to the ionizing radiation field as radiation response molecules, thus researchers are turning attention to the potential of microRNAs as biomarkers in tumor radiation response and the radiation toxicity prediction of normal tissues. In this review, we summarize the distribution of microRNAs, the progress on research of microRNAs as markers of IR, and make a hypothesis about the origin and destination of microRNAs in vivo after IR.

Autophagy Induced by a Novel Triazol Derivative Promotes Angiogenesis Through Decreasing Interferon-Inducible Protein 10 Level in Vascular Endothelial Cells

ABSTRACT

Autophagy plays an important role in angiogenesis, whereas the mechanisms of vascular endothelial cell (VEC) autophagy associated with angiogenesis remain unclear. In this study, we identified a novel triazol derivative (JL025) that significantly promoted angiogenesis both in vitro and in vivo. Moreover, JL025 had no effects on cell proliferation but dramatically increased the autophagy level of VEC. The suppression of autophagy inhibited JL025-induced angiogenesis in vitro and in vivo, suggesting that JL025-induced angiogenesis was dependent on the enhanced autophagy. Mechanistic studies indicated that JL025-induced VEC autophagy was related to the Protein Kinase B/mTOR signaling pathway. Meanwhile, JL025 decreased the antiangiogenic chemokine interferon-inducible protein 10 (IP10) protein level in human VECs. Importantly, the suppression of autophagy inhibited JL025-induced decrease of IP10 protein level, indicating that autophagy mediated the degradation of IP10. Taken together, our findings provide new insights into the relationship of VEC autophagy with angiogenesis, and JL025 may have a therapeutic potential in related diseases.

CD36 Ectodomain Detects Apoptosis in Mammalian Cells

The cells that undergo apoptosis show phosphatidylserine (PS) on the cell membrane. The fluorescently labeled hCD36_ecto is staining and detecting apoptotic cells in a flow-based assay with several advantages over Annexin V. The human CD36 ectodomain (hCD36_ecto) is stable for a range of temperatures and experimental conditions and doesn't require Ca²⁺ for detecting apoptosis and specific towards PS compared to other lipids. The blocking with unlabeled hCD36_ecto reduces the staining of Annexin V-FITC for apoptotic cells, whereas R63A does not affect the binding of Annexin V- FITC to apoptotic cells. It indicates the role of CD36-PS interaction in detecting apoptotic cells. Dual-staining with hCD36_ecto-FITC/PI is universally detecting apoptosis in different nucleated cells or eryptosis in non-nucleated RBCs. Hence, our study highlights the utility of CD36 as a probe to detect apoptosis in mammalian cells. It might be a robust, economical reagent for the scientific community to facilitate their research.

MicroRNA expression profiling involved in doxorubicin-induced cardiotoxicity using high-throughput deep-sequencing analysis

MicroRNAs (miRNAs/miRs) are sensitive biomarkers and endogenous repressors of gene expression by decreasing mRNA stability and interfering with mRNA translation. Despite a number of investigations revealing the dysregulation of miRNA expression associated with cardiotoxicity induced by doxorubicin (Dox), perturbation of miRNAs directly resulting from Dox at early stage in cardiomyocytes and the target gene interaction remain largely unknown. In the present study, high-throughput deep-sequencing was used to analyze changes in global miRNA expression in H9c2 cardiomyocytes exposed to 5 µg/ml Dox for 0, 12 or 24 h. Compared with the 0-h time point, the expression levels of 386 unique miRNAs were altered. Based on miRNA expression and fold-change, the target genes of 76 selected miRNAs were further analyzed using gene interaction networks and pathway enrichment analysis. These miRNAs were involved in the regulation of different pathways, whose functions included apoptosis, cell proliferation, extracellular matrix remodeling, oxidative stress and lipid metabolism. These differentially expressed miRNAs included let-7 family, miR-29b-3p, miR-378-3/5p, miR-351-3p, miR-664-3p, miR-455-3p, miR-298-3p, miR-702-5p, miR-128-1-5p, miR-671 and miR-421-5p. The present data indicated that global wide miRNA profiling in Dox-induced cardiomyocytes may provide a novel mechanistic insight into understanding Dox-induced heart failure and cardiotoxicity, as well as novel biomarkers and therapeutic targets.

Melatonin upregulates DNA-PKcs to suppress apoptosis of human umbilical vein endothelial cells via inhibiting miR-101 under H2O2-induced oxidative stress

Melatonin has been implicated in inhibiting oxidative stress-induced apoptosis of endothelial cells. However, the underlying mechanism remains poorly understood. In this study, we examined the effect of melatonin on apoptosis of human umbilical vein endothelial cells (HUVECs) induced by H2O2 and explored the underlying mechanisms. Our results demonstrated that DNA-dependent protein kinase catalytic subunit (DNA-PKcs) upregulation contributed to the protective role of melatonin in HUVECs under oxidative stress with H2O2. Further study showed that melatonin treatment led to a decreased level of miRNA-101, which could be responsible for DNA-PKcs upregulation and DNA-PKcs-mediated apoptosis inhibition in HUVECs under oxidative stress with H2O2. Our results also showed that melatonin increased the activity of PI3K/AKT and DNA-PKcs knockdown in melatonin-treated HUVECs that lead to inactivation of PI3K/AKT signaling under oxidative stress with H2O2. Furthermore, blockade of PI3K/AKT signal with LY294002 significantly reduced melatonin-induced apoptosis inhibition in H2O2-treated HUVECs. Taken together, our findings identify a miR-101/DNA-PKcs/PI3K/AKT signaling pathway in melatonin-induced endothelial cell apoptosis inhibition under oxidative stress with H2O2.

Upregulation of miR-200c-3p induced by NaF promotes endothelial apoptosis by activating Fas pathway

Fluoride has been considered as a risk factor of cardiovascular disease due to its endothelial toxicology. However, the mechanism underlying the endothelial toxicity of fluoride has not been clearly illustrated. MiR-200c-3p was strongly linked with endothelial function and its level is increased in serum of fluorosis patients, but it is unclear the role of miR-200c-3p in the fluoride induced endothelial dysfunction. In this study, we confirmed that fluoride exposure induced the apoptosis of endothelial cells both in established rats model and cultured human umbilical vein endothelial cells (HUVECs). And miR-200c-3p was found to be upregulated in NaF treated HUVECs. Fluoride stimulation increased caspase-dependent apoptosis through miR-200c-3p upregulation, with repressing expression of its target gene Fas-associated phosphatase 1 (Fap-1), which functioned as Fas inhibitor. This resulted in activation of Fas-associated extrinsic apoptosis via interaction with increased Fas, Fadd, Cleaved Caspase-8 and Cleaved Caspase-3. The activation of Fas-associated extrinsic apoptosis was abrogated by miR-200c-3p inhibitor. Furthermore, the antiapoptotic effect of downregulated miR-200c-3p was restored by Fap-1 siRNA. These results suggested a determinant role of the miR-200c-3p/Fap-1 axis in fluoride induced endothelial apoptosis.

NLRP3 inflammasome in endothelial dysfunction

Inflammasomes are a class of cytosolic protein complexes. They act as cytosolic innate immune signal receptors to sense pathogens and initiate inflammatory responses under physiological and pathological conditions. The NLR-family pyrin domain-containing protein 3 (NLRP3) inflammasome is the most characteristic multimeric protein complex. Its activation triggers the cleavage of pro-interleukin (IL)-1β and pro-IL-18, which are mediated by caspase-1, and secretes mature forms of these mediators from cells to promote the further inflammatory process and oxidative stress. Simultaneously, cells undergo pro-inflammatory programmed cell death, termed pyroptosis. The danger signals for activating NLRP3 inflammasome are very extensive, especially reactive oxygen species (ROS), which act as an intermediate trigger to activate NLRP3 inflammasome, exacerbating subsequent inflammatory cascades and cell damage. Vascular endothelium at the site of inflammation is actively involved in the regulation of inflammation progression with important implications for cardiovascular homeostasis as a dynamically adaptable interface. Endothelial dysfunction is a hallmark and predictor for cardiovascular ailments or adverse cardiovascular events, such as coronary artery disease, diabetes mellitus, hypertension, and hypercholesterolemia. The loss of proper endothelial function may lead to tissue swelling, chronic inflammation, and the formation of thrombi. As such, elimination of endothelial cell inflammation or activation is of clinical relevance. In this review, we provided a comprehensive perspective on the pivotal role of NLRP3 inflammasome activation in aggravating oxidative stress and endothelial dysfunction and the possible underlying mechanisms. Furthermore, we highlighted the contribution of noncoding RNAs to NLRP3 inflammasome activation-associated endothelial dysfunction, and outlined potential clinical drugs targeting NLRP3 inflammasome involved in endothelial dysfunction. Collectively, this summary provides recent developments and perspectives on how NLRP3 inflammasome interferes with endothelial dysfunction and the potential research value of NLRP3 inflammasome as a potential mediator of endothelial dysfunction.

Crosstalk of MicroRNAs and Oxidative Stress in the Pathogenesis of Cancer

Oxidative stress refers to an imbalance between reactive oxygen species (ROS) generation and body's capability to detoxify the reactive mediators or to fix the relating damage. MicroRNAs are considered to be important mediators that play essential roles in the regulation of diverse aspects of carcinogenesis. Growing studies have demonstrated that the ROS can regulate microRNA biogenesis and expression mainly through modulating biogenesis course, transcription factors, and epigenetic changes. On the other hand, microRNAs may in turn modulate the redox signaling pathways, altering their integrity, stability, and functionality, thus contributing to the pathogenesis of multiple diseases. Both ROS and microRNAs have been identified to be important regulators and potential therapeutic targets in cancers. However, the information about the interplay between oxidative stress and microRNA regulation is still limited. The present review is aimed at summarizing the current understanding of molecular crosstalk between microRNAs and the generation of ROS in the pathogenesis of cancer.

MicroRNA-202-3p Targets Brain-Derived Neurotrophic Factor and Is Involved in Depression-Like Behaviors

BACKGROUND

Brain-derived neurotrophic factor (BDNF) and microRNA (miRNA) play crucial roles in the etiology of depression. However, the molecular mechanisms underlying this disease are not fully understood. The primary objective of this study was to investigate the relationship between miR-202-3p and BDNF in a chronic unpredictable mild stress (CUMS) model.

METHODS

Depression model was established with chronic mild unpredictable mild stimulation (CUMS) combined with solitary feeding. The expression levels of miR-202-3p and BDNF in rat hippocampus were measured by qRT-PCR. The novelty inhibition feeding test (NSFT), sucrose preference test (SPT), and forced swimming test (FST) were used to evaluate the functions of miR-202-3p and BDNF. Target gene prediction and screening and luciferase reporter assay were used to verify the target of miR-202-3p. The expression levels of BNDF, CREB1 and p-CREB1 were detected by Western blot.

RESULTS

Upregulation of miR-202-3p was associated with decreased expression of BDNF in the hippocampus of the CUMS model. Antidepressant was observed when LV-BDNF or LV-si-miR-202-3p was injected into the hippocampus. In addition, in the rat hippocampus and cultured nerve cells, the expression levels of BDNF and cyclic AMP response element binding protein 1 (CREB1), which is a target gene of BDNF, were reduced after LV-miR-202-3p injection. Overexpression of miR-202-3p aggravated depressive behavior and decreased the expression levels of BDNF. Luciferase reporter assay also confirmed that BDNF was a target of miR-202-3p.

CONCLUSION

Silencing miR-202-3p can reduce the damage to hippocampal nerve in CUMS rats; the mechanism may be related to the upregulation of BNDF expression. miR-202-3p may be an effective target for the treatment of depression.

MicroRNA-24-3p inhibition prevents cell growth of vascular smooth muscle cells by targeting Bcl-2-like protein 11

Numerous reports have shown that dysfunction of vascular smooth muscle cells (VSMCs) serves a critical function in the development of cardiovascular disease, including coronary heart disease (CHD). microRNAs (miRNAs/miRs) have been reported to play important roles in regulating the function of VSMCs. The present study aimed to determine the role of miR-24-3p in VSMCs and to uncover the underlying mechanism. The expression of miR-24-3p in the peripheral blood samples of CHD patients was measured by reverse transcription-quantitative (RT-q)PCR. It was found that the level of miR-24-3p in the peripheral blood of patients with CHD was significantly upregulated compared with that in healthy controls. A dual luciferase reporter assay was performed to determine whether Bcl-2-like protein 11 (Bcl-2L11) was a target gene of miR-24-3p, and it was identified that Bcl-2L11 was a direct target of miR-24-3p. The mRNA level and protein expression of Bcl-2L11 in the peripheral blood of patients with CHD were measured by RT-qPCR and western blotting, respectively. The findings suggested that Bcl-2L11 was downregulated in the peripheral blood of patients with CHD. In addition, it was found that downregulation of miR-24-3p suppressed VSMC proliferation and promoted VSMC apoptosis, while the effects of the miR-24-3p inhibitor on cell viability and apoptosis were reversed by Bcl-2L11-small interfering (si)RNA. Additionally, downregulation of miR-24-3p increased the levels of Bcl-2L11, caspase-3 and Bax, and decreased Bcl-2 expression in VSMCs; these changes were abolished by Bcl-2L11-siRNA. In conclusion, the aforementioned results indicated that miR-24-3p was an important regulator in VSMC proliferation and apoptosis by targeting Bcl-2L11, which suggested that miR-24-3p might be a potential therapeutic target for the treatment of CHD.

Radiation Exposure of Peripheral Mononuclear Blood Cells Alters the Composition and Function of Secreted Extracellular Vesicles

Normal tissue toxicity is a dose-limiting factor in radiation therapy. Therefore, a detailed understanding of the normal tissue response to radiation is necessary to predict the risk of normal tissue toxicity and to development strategies for tissue protection. One component of normal tissue that is continuously exposed during therapeutic irradiation is the circulating population of peripheral blood mononuclear cells (PBMC). PBMCs are highly sensitive to ionizing radiation (IR); however, little is known about how IR affects the PBMC response on a systemic level. It was the aim of this study to investigate whether IR was capable to induce changes in the composition and function of extracellular vesicles (EVs) secreted from PBMCs after radiation exposure to different doses. Therefore, whole blood samples from healthy donors were exposed to X-ray radiation in the clinically relevant doses of 0, 0.1, 2 or 6 Gy and PBMC-secreted EVs were isolated 72 h later. Proteome and miRNome analysis of EVs as well as functional studies were performed. Secreted EVs showed a dose-dependent increase in the number of significantly deregulated proteins and microRNAs. For both, proteome and microRNA data, principal component analysis showed a dose-dependent separation of control and exposed groups. Integrated pathway analysis of the radiation-regulated EV proteins and microRNAs consistently predicted an association of deregulated molecules with apoptosis, cell death and survival. Functional studies identified endothelial cells as an efficient EV recipient system, in which irradiation of recipient cells further increased the uptake. Furthermore an apoptosis suppressive effect of EVs from irradiated PBMCs in endothelial recipient cells was detected. In summary, this study demonstrates that IR modifies the communication between PBMCs and endothelial cells. EVs from irradiated PBMC donors were identified as transmitters of protective signals to irradiated endothelial cells. Thus, these data may lead to the discovery of biomarker candidates for radiation dosimetry and even more importantly, they suggest EVs as a novel systemic communication pathway between irradiated normal, non-cancer tissues.

miR-101-3p induces vascular endothelial cell dysfunction by targeting tet methylcytosine dioxygenase 2

Endothelial cell (EC) dysfunction represents an early key event in atherosclerosis. Recently, MicroRNAs have been demonstrated to regulate EC function. miR-101-3p has been discovered to regulate cell apoptosis and proliferation in cardiovascular diseases. Therefore, the aim of the current study was to clarify whether miR-101-3p regulates the dysfunction of vascular endothelial cells. In this study, the transfection of human umbilical vein endothelial cells (HUVECs) with miR-101-3p mimic induced reactive oxygen species (ROS) production, EC dysfunction, and activated nuclear factor-κB (NF-κB), whereas transfection with miR-101-3p inhibitor alleviated these events. The antioxidant N-acetylcysteine alleviated miR-101-3p-induced EC dysfunction. Moreover, we observed that miR-101-3p inhibited the expression of tet methylcytosine dioxygenase 2 (TET2) at the posttranscriptional level, resulting in increased ROS production and activated NF-κB. TET2 overexpression inhibited ROS production, EC dysfunction, and NF-κB activation in miR-101-3p-transfected HUVECs. These results indicate that miR-101-3p induces EC dysfunction by targeting TET2, which regulates ROS production, EC dysfunction, and NF-κB activation. Taken together, our current study reveals a novel pathway associated with EC dysfunction. The modulation of miR-101-3p and TET2 expression levels may serve as a potential target for therapeutic strategies for atherosclerosis.

An acute lytic cell death induced by xanthohumol obstructed ROS detecting in HL-60 cells

Serum is an important component in cell culture medium. It also possesses potent antioxidant properties. Therefore, the conventional protocols for detecting reactive oxygen species (ROS) in cultured cells with fluorescent probes include washing and suspending cells with serum-free buffers, such as PBS. This transient serum deprivation is essential for the ROS detecting. Unfortunately, it may also cause unexpected results, which push us to choose more optimal experiment conditions. In the present study, we found an acute lytic cell death induced by xanthohumol (XN), which obstructed ROS detecting in human leukemia cell line HL-60 cells. XN induced ROS burst, caused cell swelling, membrane permeability increase, LDH release, and ultimately an acute lytic cell death and cell rupture. These effects could be alleviated by the antioxidant N-Acetyl-L-cysteine (NAC). Apoptosis, pyroptosis or necroptosis were not observed in this process. Results also indicated that 2% serum addition had already completely scavenged ROS induced by 10 μM XN. Taken together, it is strongly suggested to detecting ROS in a serum-free medium when studying where and how ROS generated in cells. The concentration at the ROS maximum point (10 μM XN in this study) can be selected as the optimal concentration.

miRNA‑101‑3p.1 as an independent diagnostic biomarker aggravates chronic obstructive pulmonary disease via activation of the EGFR/PI3K/AKT signaling pathway

Exploring independent biomarkers and delineating pathogenic mechanisms could improve the early diagnosis and treatment of chronic obstructive pulmonary disease (COPD). In the present study, a study was conducted to determine the diagnostic potential of miRNA‑101‑3p.1 in identifying stable COPD (SCOPD) and acute exacerbation of COPD (AECOPD) patients and to reveal the molecular mechanism by which miRNA‑101‑3p.1 regulates COPD progression. miRNA‑101‑3p.1 profiles in peripheral blood mononuclear cells of COPD patients were evaluated. Subsequently, receiver operating characteristic curves were created to demonstrate the diagnostic accuracy of miRNA‑101‑3p.1 in discriminating SCOPD and AECOPD. Finally, the molecular mechanism by which miRNA‑101‑3p.1 regulates COPD progression was explored. The present study revealed that patients with COPD, and especially patients with AECOPD, had significantly increased levels of miRNA‑101‑3p.1 and the level of miRNA‑101‑3p.1 was closely correlated with CAT score and FEV1% predicted. Notably, miRNA‑101‑3p.1 accurately discriminated SCOPD and AECOPD. Furthermore, increasing miRNA‑101‑3p.1 promoted cell proliferation and induced the expression of inflammatory cytokines. Mechanistic investigations revealed that miRNA‑101‑3p.1 inhibited the expression of von Hippel‑Lindau tumor suppressor (pVHL) and ubiquitin conjugating enzyme E2 D1 (UBE2D1). pVHL and UBE2D1 co‑upregulated HIF‑1α, and HIF‑1α mediated activation of the EGFR/PI3K/AKT signaling pathway. The present results collectively demonstrated that miRNA‑101‑3p.1 could act as an independent biomarker for the diagnosis of SCOPD and AECOPD, and that miRNA‑101‑3p.1 facilitates COPD progression by activating the EGFR/PI3K/AKT signaling pathway.

The upregulation of miR-101 promotes vascular endothelial cell apoptosis and suppresses cell migration in acute coronary syndrome by targeting CDH5

MicroRNAs (miRNAs) have been reported to be of great importance in a wide range of physiological and pathological processes, including acute coronary syndrome (ACS). However, the exact role of miRNAs in the pathogenesis of ACS has not been fully elucidated. In this study, we found that miR-101 was significantly upregulated in the serum samples of patients with acute coronary syndrome compared with healthy controls. In human umbilical vein endothelial cells (HUVECs), the overexpression of miR-101 drastically promoted cell apoptosis and inhibited cell migration. Mechanistically, miR-101 repressed the expression of CHD5 by targeting its 3'-untranslated region (3'UTR). The silencing of CHD5 also induced cell apoptosis and suppressed cell migration in HUVECs. Taken together, our findings suggest that the miR-101-CHD5 axis may play an important role in the biological behaviors of endothelial cells during the pathogenesis of ACS and may afford an effective diagnostic marker and a powerful therapy for this disease.

Human PBMCs fight or flight response to starvation stress: Increased T-reg, FOXP3, and TGF-β1 with decreased miR-21 and Constant miR-181c levels

Regulatory T-lymphocytes play a prominent role in autoimmunity, allergy, and cancer. In some conditions such as inflammation and tumor, immune cells are encountered with metabolic stress. Emerging evidence indicates the contribution of microRNAs in both metabolism and immune regulation. Herewith, we have examined the in vitro effects of serum starvation for 16, 48, 72 and 96 h on the expression of T-reg differentiation markers (CD4, CD25, CD127, and FOXP3) as well as on the Transforming Growth Factor-β1 (TGF-β1) and some microRNAs (miR-21,-29a,-31,146a,-155,-181a and -181c) levels in human Peripheral Blood Mononuclear Cells (PBMCs). The percentage of CD4⁺CD25⁺CD127low/-FOXP3⁺ T-regs, as well as FOXP3 expression, was increased in starved lymphocytes (p < 0.01). 96 h-starved PBMCs had the lowest T-eff/T-reg ratio (p < 0.05). All the studied miRNAs except miR-181c were significantly down-regulated in those cells (p < 0.05), in particular, miR-29a and miR-155 were sharply declined in 48h-starved PBMCs (p < 0.01). There was a negative correlation between time of starvation and microRNAs expression, except for miR-181c (r-value = -0. 61 to -0.9 and p-value = 0.037 to 0). The percentage of T-reg was inversely correlated with all miRNAs levels except for miR-31 and miR-181c (r-value = -0.68 to -0.78 and p-value = 0.015 to 0.003). FOXP3 expression exhibited a same degree of negative correlation with miR-31 and miR-155 expression levels (r = -0.57 and p =  0.05, for both). Increasing starvation duration led to a rise inTGF-β1 protein levels (p<0.01), especially its active form (P<0.001). This study introduced the serum starvation as a tool for immunoregulation which acts probably through increasing TGF-β1 production and inducing some alterations in microRNAs expression.

High PGAM5 expression induces chemoresistance by enhancing Bcl-xL-mediated anti-apoptotic signaling and predicts poor prognosis in hepatocellular carcinoma patients

Hepatocellular carcinoma (HCC) is the one of most common and deadly cancers, and is also highly resistant to conventional chemotherapy treatments. Mitochondrial phosphoglycerate mutase/protein phosphatase (PGAM5) regulates mitochondrial homeostasis and cell death, however, little is known about its roles in cancer. The aim of this study was to explore the clinical significance and potential biological functions of PGAM5 in hepatocellular carcinoma. For the first time, our results show that PGAM5 is significantly upregulated in HCC compared with corresponding adjacent noncancerous hepatic tissues and high PGAM5 expression is an independent predictor of reduced survival times in both univariate and multivariate analyses. Additionally, in vivo and in vitro studies showed that depleting PGAM5 expression inhibited tumor growth and increased the 5-fluorouracil sensitivity of HCC cells. Conversely, restoring PGAM5 expression in PGAM5-knockdown cells dramatically enhanced HCC cell resistance to 5-fluorouracil. Importantly, we demonstrated that the mechanism of 5-fluorouracil resistance conferred to HCC cells by PGAM5 was via inhibiting BAX- and cytochrome C-mediated apoptotic signaling by interacting and stabilizing Bcl-xL. Consistently, in the same cohorts of HCC patient tissues, Bcl-xL expression was positively correlated with PGAM5, and together predicted poor prognoses. In Conclusion, Our data highlight the molecular etiology and clinical significance of PGAM5 in HCC. Targeting the novel signaling pathway mediated by PGAM5/Bcl-xL may represent a new therapeutic strategy to improve the survival outcomes of HCC patients.

Advances in stroke pharmacology

Stroke occurs when a cerebral blood vessel is blocked or ruptured, and it is the major cause of death and adult disability worldwide. Various pharmacological agents have been developed for the treatment of stroke either through interrupting the molecular pathways leading to neuronal death or enhancing neuronal survival and regeneration. Except for rtPA, few of these agents have succeeded in clinical trials. Recently, with the understanding of the pathophysiological process of stroke, there is a resurrection of research on developing neuroprotective agents for stroke treatment, and novel molecular targets for neuroprotection and neurorestoration have been discovered to predict or offer clinical benefits. Here we review the latest major progress of pharmacological studies in stroke, especially in ischemic stroke; summarize emerging potential therapeutic mechanisms; and highlight recent clinical trials. The aim of this review is to provide a panorama of pharmacological interventions for stroke and bridge basic and translational research to guide the clinical management of stroke therapy.

miR-5591-5p regulates the effect of ADSCs in repairing diabetic wound via targeting AGEs/AGER/JNK signaling axis

Advanced glycation end products/advanced glycation end products receptor (AGEs/AGER) interaction triggers reactive oxygen species (ROS) generation and activates downstream signal pathways and induces apoptosis in endothelial progenitor cells. A number of studies have revealed the involvement of microRNAs (miRNAs) in regulating intracellular ROS production and apoptosis. However, few studies explore the role of miRNAs in regulating the effect of adipose tissue-derived stem cells (ADSCs) in repairing diabetic wound and the associated cellular mechanisms remain unclear. In this study, ADSCs were exposed to AGEs, then siRNA for AGER was transfected into ADSCs. We found that AGEs/AGER axis induced ROS generation and apoptosis in ADSCs. AGEs treatment downregulated miR-5591-5p in ADSCs, which directly targeted AGER. miR-5591-5p suppressed AGEs/AGER axis-mediated ROS generation and apoptosis in ADSCs in vitro. In addition, miR-5591-5p promoted cell survival and enhanced the ability of ADSCs for repairing cutaneous wound in vivo. Furthermore, we confirmed that c-jun kinase (JNK) signal was involved in the inhibitory effect of miR-5591-5p on AGEs/AGER axis-induced ROS generation and apoptosis in ADSCs. Thus, these results indicated that miR-5591-5p targeting AGEs/AGER/JNK signaling axis possibly regulates the effect of ADSCs in repairing diabetic wound.

miR-126 in Peripheral Blood Mononuclear Cells Negatively Correlates with Risk and Severity and is Associated with Inflammatory Cytokines as well as Intercellular Adhesion Molecule-1 in Patients with Coronary Artery Disease

OBJECTIVES

The aim of this study was to evaluate the association of miR-126 with risk and severity of coronary artery disease (CAD) as well as its correlation with inflammatory cytokines and endothelial related proteins.

METHODS

In total, 215 patients suspected of CAD who underwent coronary angiography were enrolled in this case control study and were divided into a CAD group (n = 119) and control group (n = 96). miR-126 relative expression was assessed by real-time polymerase chain reaction.

RESULTS

The relative expression of miR-126 decreased in CAD patients compared to controls (p < 0.001), and the receiver operating characteristic curve showed a good diagnostic value of miR-126 for CAD risk with an area under the curve of 0.801 (95% CI 0.740-0.861). Additionally, miR-126 was negatively correlated with high-sensitivity C-reactive protein levels (p < 0.001) and reversely associated with TNF-α (p = 0.008) and IL-6 (p < 0.001) levels, while it was positively correlated with the IL-10 level (p < 0.001). In addition, miR-126 was negatively associated with intercellular adhesion molecule-1 (ICAM-1) levels (p = 0.001), and no association of miR-126 with vascular endothelial growth factor was detected (p = 0.142). Meanwhile, the miR-126 relative level was negatively associated with the Gensini score (p < 0.001).

CONCLUSIONS

Peripheral blood mononuclear cell miR-126 predicts risk and severity and correlates with inflammatory cytokines as well as ICAM-1 in patients with CAD.

MALAT1/miR-101-3p/MCL1 axis mediates cisplatin resistance in lung cancer

In this study, we investigated the mechanism by which lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) mediates cisplatin resistance in lung cancer. Lung cancer patients with high MALAT1 levels were associated with cisplatin resistance and low overall survival. Moreover, cisplatin-resistant A549/DDP cells showed higher MALAT1 expression than cisplatin-sensitive lung cancer cells (A549, H460, H1299 and SPC-A1). Dual luciferase reporter and RNA immunoprecipitation assays showed direct binding of miR-101-3p to MALAT1. MALAT1 knockdown in lung cancer cells resulted in miR-101-3p upregulation and increased cisplatin sensitivity. In addition, miR-101-3p decreased myeloid cell leukemia 1 (MCL1) expression by binding to the 3’-untranslated region (3’-UTR) of its mRNA. These results demonstrate that MALAT1/miR-101-3p/MCL1 signaling underlies cisplatin resistance in lung cancer.

In vitro transfection of anti-tumor miR-101 induces BIM, a pro-apoptotic protein, expression in acute myeloid leukemia (AML)

Acute myeloid leukemia (AML) frequently relapses after initial treatment, though it is possible that drug resistance occurs. Hence, it seems necessary to develop novel therapies such as gene therapy specifically via miRNA transfection. MicroRNA-101 has been considered as a tumor suppressor in different types of cancer. It is demonstrated that exogenous miR-101 transfection is associated with decreased viability in AML in this paper. Besides, the increase of pro-apoptotic protein BIM expression in both mRNA and protein level has been illustrated. The recent findings provide an insight into the novel function of miR-101 in AML by activating BIM as an important mediator in intrinsic apoptosis pathways. Generally, miR-101 has been considered as a therapeutic target in our data and might have a valuable role in AML.

The caspase-8/Bid/cytochrome c axis links signals from death receptors to mitochondrial reactive oxygen species production

Ligation of the death receptors for TNF-α, FasL, and TRAIL triggers two common pathways, caspase-dependent intrinsic apoptosis and intracellular reactive oxygen species (ROS) generation. The apoptotic pathway is well characterized; however, a signaling linker between the death receptor and ROS production has not been clearly elucidated. Here, we found that death receptor-induced ROS generation was strongly inhibited by mitochondrial complex I and II inhibitors, but not by inhibitors of NADPH oxidase, lipoxygenase, cyclooxygenase or xanthine oxidase, indicating that ROS are mostly generated by the impairment of the mitochondrial respiratory chain. ROS generation was accompanied by caspase-8 activation, Bid cleavage, and cytochrome c release; it was blocked in FADD- and caspase-8-deficient cells, as well as by caspase-8 knockdown and inhibitor. Moreover, Bid knockdown abrogated TNF-α- or TRAIL-induced ROS generation, whereas overexpression of truncated Bid (tBid) or knockdown of cytochrome c spontaneously elevated ROS production. In addition, p53-overexpressing cells accumulated intracellular ROS via cytochrome c release mediated by the BH3-only protein Noxa induction. In a cell-free reconstitution system, caspase-8-mediated Bid cleavage and recombinant tBid induced mitochondrial cytochrome c release and ROS generation, which were blocked by Bcl-xL and antioxidant enzymes. These data suggest that anti-apoptotic Bcl-2 proteins play an important role in mitochondrial ROS generation by preventing cytochrome c release. These data provide evidence that the FADD/caspase-8/Bid/cytochrome c axis is a crucial linker between death receptors and mitochondria, where they play a role in ROS generation and apoptosis.