LncRNA CYTOR attenuates sepsis-induced myocardial injury via regulating miR-24/XIAP

This work aims to investigate the function and mechanism of long non-coding RNA (lncRNA) cytoskeleton regulator RNA (CYTOR) in myocardial injury induced by sepsis. The sepsis-induced myocardial injury model in mice was established by intraperitoneal injection of LPS (10 mg/kg) in vivo, and cardiomyocyte H9c2 was treated with LPS to mimic sepsis in vitro. CYTOR expression and miR-24 expression were detected by qRT-PCR. After up-regulation or down-regulation of CYTOR and miR-24 expression in the H9c2 cells, and the viability of the cells was detected via MTT assay, and cell apoptosis was detected by TUNEL assay. Western blot was applied to determine the expression level of caspase 3, Bax and X-chromosome-linked inhibitor of apoptosis (XIAP). Interaction between CYTOR and miR-24 was determined by bioinformatics analysis, RT-PCR and dual luciferase reporter assay. Interaction between miR-24 and XIAP was determined through bioinformatics analysis, RT-PCR, western blot and dual luciferase reporter assay. CYTOR was markedly down-regulated. CYTOR interacted with miR-24, and negatively regulated its expression level. Over-expression of CYTOR or transfection of miR-24 inhibitors significantly promoted viability and inhibited apoptosis of H9c2 cells, while the knockdown of CYTOR and transfection of miR-24 mimics had opposite effects. CYTOR suppressed the expression level of apoptosis-related proteins, but miR-24 increased them. miR-24 directly targeted the 3'UTR of XIAP, and suppressed it, and XIAP was modulated indirectly by CYTOR. Down-regulation of CYTOR aggravates sepsis-induced cardiac injury via regulating miR-24 and XIAP.     

Circ_0062491 alleviates LPS-induced apoptosis and inflammation in periodontitis by regulating miR-498/SOCS6 axis

Periodontitis is a prevalent chronic inflammatory disease. Circular RNAs (circRNAs) have been revealed to play roles in the inflammatory response. Hence, this work aimed to explore the role and mechanism of circ_0062491 in periodontitis progression. Human periodontal ligament cells (PDLCs) were isolated from the periodontal ligament (PDL) of the healthy teeth with orthodontic requirement after tooth extraction. In vitro experiments were conducted by cell counting Kit-8 (CCK-8) assay, flow cytometry, Western blot, and ELISA to determine cell viability, apoptosis, and inflammatory response. The binding between miR-498 and circ_0062491 or SOCS6 was confirmed using dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Circ_0062491 expression was decreased in periodontitis and LPS-induced PDLCs. Restoration of circ_0062491 attenuated LPS-induced apoptosis and inflammation in PDLCs in vitro. Mechanistically, circ_0062491 functioned as a sponge for miR-498, and miR-498 directly targeted SOCS6. Rescue experiments showed that miR-498 up-regulation reversed the protective action of circ_0062491 on PDLCs under LPS treatment. Moreover, silencing of miR-498 protected PDLCs from LPS-induced apoptosis and inflammation, which were abolished by SOCS6 knockdown. Circ_0062491 protected PDLCs from LPS-induced apoptosis and inflammation, suggesting a new target for the amelioration of periodontitis patients.     

Unique sequence of a high molecular weight myosin light chain kinase is involved in interaction with actin cytoskeleton

Resolution of neutrophil mediated inflammation is achieved, in part, through induction of neutrophil apoptosis. This constitutively expressed programme can be delayed by inflammatory mediators and induced by ligation of the Fas receptor. However, functional activation of the neutrophil results in resistance to Fas signalled death. We evaluated the effects of Fas antibody engagement on caspase activation and mitochondrial permeability, and the impact of co-stimulation by lipopolysaccharide (LPS) or granulocyte macrophage-colony stimulating factor (GM-CSF) on these events. Fas engagement by an agonistic anti-Fas antibody resulted in enhanced caspase 3 and 8 activity and increased mitochondrial permeability. Studies with pharmacological inhibitors of caspase activity showed that activation of caspase 8 occurred before, and activation of caspase 3 occurred after mitochondrial disruption. The mitochondrial stabilising agent bongkrekic acid also inhibited caspase activation and apoptosis. LPS, GM-CSF and increased glutathione stabilised the mitochondria and inhibited caspase 3. Caspase 8 activity was also inhibited by co-stimulation through a mechanism independent of mitochondrial stabilisation. Glutathione directly inhibited caspase 3 and 8 activity. We conclude inhibition of Fas antibody induced apoptosis by inflammatory proteins is associated with augmented mitochondrial stability and reduced caspase 3 activity that may be glutathione mediated.     

MiR-29b-3p aggravates cardiac hypoxia/reoxygenation injury via targeting PTX3

Our current research aimed to decipher the role and underlying mechanism with regard to miR-29b-3p involving in myocardial ischemia/reperfusion (I/R) injury. In the present study, cardiomyocyte H9c2 cell was used, and hypoxia/reoxygenation (H/R) model was established to mimic the myocardial I/R injury. The expressions of miR-29b-3p and pentraxin 3 (PTX3) were quantified deploying qRT-PCR and Western blot, respectively. The levels of LDH, TNF-α, IL-1β and IL-6 were detected to evaluate cardiomyocyte apoptosis and inflammatory response. Cardiomyocyte viability and apoptosis were examined employing CCK-8 assay and flow cytometry, respectively. Verification of the targeting relationship between miR-29b-3p and PTX3 was conducted using a dual-luciferase reporter gene assay. It was found that miR-29b-3p expression in H9c2 cells was up-regulated by H/R, and a remarkable down-regulation of PTX3 expression was demonstrated. MiR-29b-3p significantly promoted of release of inflammatory cytokines of H9c2 cells, and it also constrained the proliferation and promoted the apoptosis of H9c2 cells. Additionally, PTX3 was inhibited by miR-29b-3p at both mRNA and protein levels, and it was identified as a direct target of miR-29b-3p. PTX3 overexpression could reduce the inflammatory response, increase the viability of H9c2 cells, and inhibit apoptosis. Additionally, PTX3 counteracted the function of miR-29b-3p during the injury of H9c2 cells induced by H/R. In summary, miR-29b-3p was capable of aggravating the H/R injury of H9c2 cells by repressing the expression of PTX3.     

MicroRNA-146 protects A549 and H1975 cells from LPS-induced apoptosis and inflammation injury

Pneumonia is an inflammatory condition affecting the lungs, in which pro-inflammatory cytokines are secreted. It has been shown that microRNA-146 (miR-146) is involved in the regulation of immune and inflammatory responses. The present study explored the protective effects of miR-146 overexpression on lipopolysaccharide (LPS)-mediated injury in A549 and H1975 cells. In this study, A549 and H1975 cells were transfected with miR-146 mimic or inhibitor, and then were subjected with LPS. Thereafter, cell viability, colony formation capacity, apoptosis, the release of proinflammatory factors, Sirt1 expression, and the expression of NF-κB and Notch pathway proteins were respectively assessed. As a result, miR-146 overexpression exerted protective functions on LPS-damaged A549 and H1975 cells, as evidenced by the increases in cell viability and colony number, the decrease in apoptotic cell rate, as well as the down-regulations of IL-1, IL-6, and TNF-α. Sirt1 can be positively regulated by miR-146. Furthermore, miR-146 overexpression blocked NF-κB and Notch pathways, while these blocking effects were abolished when Sirt1 was silenced. The findings in the current study indicated that miR-146 protected A549 and H1975 cells from LPS-induced apoptosis and inflammation injury. miR-146 exerted protective functions might be via up-regulation of Sirt1 and thereby blocking NF-κB and Notch pathways.     

Pulmonary AngII promotes LPS-induced lung inflammation by regulating microRNA-143

Angiotensin converting enzyme 2 (ACE2) is a terminal carboxypeptidase, which cleaves single terminal residues from several bioactive peptides such as Angiotensin II (AngII). Many investigations indicated that ACE2 functions in angiotensin system and plays a crucial role in inflammatory lung diseases. However, the mechanism behind the involvement of ACE2 in inflammatory lung disease has not been fully elucidated. In this study, BEAS-2B cells were treated with gradient concentration of AngII and lipopolysaccharide (LPS) to induce inflammatory condition. Quantitative RT-PCR was performed to detect the level of ACE2 and miR-143-3p. Western blotting and immunofluorescence assays were performed to measure the expression of related proteins. The levels of inflammatory cytokines and cell viability were respectively measured by ELISA and CCK-8 kits. And ACE2 activity was detected by corresponding commercial kits. Bioinformatics methods were employed to predict the potential microRNA targeting ACE2, which was then confirmed by dual luciferase reporter assay. The results showed that ACE2 expression and activity were time-dependently decreased in LPS group for the first 12 h, after which this tendency was reversed. AngII addition enhanced these effects, compared with LPS group. Additionally, the lowest ACE2 activity level was found in both LPS and AngII + LPS groups at 6 h. The number of nuclei and the ACE2 expression were decreased in LPS groups at 6 h and further reduced by addition of AngII, detected by immunofluorescence. Moreover, ACE2 was validated to be a direct target of miR-143-3p. Pretreatment of AngII and LPS regulated the activity of ACE2, increased the expression of proinflammatory cytokines and cell apoptosis and regulated the expression of Bax, Bcl-2 and cleaved caspase-3 in BEAS-2B cells, which could be reversed by transfecting miR-143-3p inhibitor. The results collectively suggest that AngII promotes LPS-induced inflammation by regulating miR-143-3p in BEAS-2B cells. Therefore, miR-143-3p is considered a potential molecular target for the treatment of lung inflammation.     

TanshinoneIIA and Cryptotanshinone Protect against Hypoxia-Induced Mitochondrial Apoptosis in H9c2 Cells

Mitochondrial apoptosis pathway is an important target of cardioprotective signalling. Tanshinones, a group of major bioactive compounds isolated from Salvia miltiorrhiza, have been reported with actions against inflammation, oxidative stress, and myocardial ischemia reperfusion injury. However, the actions of these compounds on the chronic hypoxia-related mitochondrial apoptosis pathway have not been investigated. In this study, we examined the effects and molecular mechanisms of two major tanshonones, tanshinone IIA (TIIA) and cryptotanshinone (CT) on hypoxia induced apoptosis in H9c2 cells. Cultured H9c2 cells were treated with TIIA and CT (0.3 and 3 μΜ) 2 hr before and during an 8 hr hypoxic period. Chronic hypoxia caused a significant increase in hypoxia inducible factor 1α expression and the cell late apoptosis rate, which was accompanied with an increase in caspase 3 activity, cytochrome c release, mitochondria membrane potential and expression of pro-apoptosis proteins (Bax and Bak). TIIA and CT (0.3 and 3 μΜ), in concentrations without affecting the cell viability, significantly inhibited the late apoptosis and the changes of caspase 3 activity, cytochrome c release, and mitochondria membrane potential induced by chronic hypoxia. These compounds also suppressed the overexpression of Bax and reduced the ratio of Bax/Bcl-2. The results indicate that TIIA and CT protect against chronic hypoxia induced cell apoptosis by regulating the mitochondrial apoptosis signaling pathway, involving inhibitions of mitochondria hyperpolarization, cytochrome c release and caspase 3 activity, and balancing anti- and pro-apoptotic proteins in Bcl-2 family proteins.     

Circ_0026579 alleviates LPS-induced WI-38 cells inflammation injury in infantile pneumonia

Circular RNA (circRNA) represents an important regulator in infantile pneumonia progression. To clarify the role of circ_0026579 in this disease, LPS was used to treat WI-38 cells to mimic inflammation injury. The levels of inflammatory factors were determined by ELISA assay. Cell proliferation and apoptosis were measured by MTT assay, EdU staining and flow cytometry. The protein levels of cyclinD1, cleaved-caspase-3 and insulin-like growth factor 2 (IGF2) were examined using Western blot analysis. Cell oxidative stress was assessed by detecting MDA level and SOD activity. The expression of circ_0026579, miR-24-3p and IGF2 were analyzed using quantitative real-time PCR, and the interaction between miR-24-3p and circ_0026579 or IGF2 was confirmed by dual-luciferase reporter assay and RIP assay. LPS induced inflammation in WI-38 cells. Circ_0026579 expression was promoted in LPS-induced WI-38 cells, and its knockdown alleviated LPS-induced WI-38 cells inflammation. MiR-24-3p was sponged by circ_0026579, and its expression was reduced by LPS. MiR-24-3p inhibitor reversed the regulation of circ_0026579 knockdown on LPS-induced WI-38 cells inflammation. IGF2 was targeted by miR-24-3p, and its expression could be enhanced by LPS. MiR-24-3p relieved the inflammation of WI-38 cells which could be abolished by IGF2 overexpression. Circ_0026579 positively regulated IGF2 expression through sponging miR-24-3p. Circ_0026579 knockdown alleviated LPS-induced WI-38 cells inflammation by miR-24-3p/IGF2 axis, suggesting that circ_0026579 might contribute to infantile pneumonia progression.     

MicroRNA-384-5p regulates ischemia-induced cardioprotection by targeting phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit delta (PI3K p110δ)

MicroRNAs (miRNAs) are a novel class of powerful, endogenous regulators of gene expression. This study identified 16 differentially expressed miRNAs in ischemic myocardium of rats using TaqMan Low Density Array. In addition, bioinformatics analyses, such as Gene ontology and Pathway assays, were applied to determine the apoptosis pathway, only regulated by miR-384-5p, and all the associated target genes (PIK3CD, PPP3CA, PPP3CB, PPP3R1, CASP3 and IL1A). These target genes, besides PIK3CB, were shown to be significantly up-regulated by qRT-PCR assay, which further suggested that PIK3CD, PPP3CA, PPP3R1, CASP3, IL1A could be regulated by miR-384-5p. MTT, Western blot, qRT-PCR and luciferase assays were used to investigate the role of miR-384-5p in myocardial ischemia. We found that cleaved caspase3 expression was up-regulated by miR-384-5p and down-regulated by miR-384-5p inhibitor suggesting that apoptosis pathway was regulated by miR-384-5p. We also found that miR-384-5p suppressed cell viability while miR-384-5p inhibitor improved it, confirming H9c2 cell survival was affected by miR-384-5p. In addition, the PIK3CD protein level in H9c2 cells was up-regulated by miR-384-5p inhibitor. We found that miR-384-5p expression level decreased and PIK3CD protein level increased in both ischemic myocardium of rats and hypoxic H9c2 cells, and that miR-384-5p suppress PIK3CD expression through a miR-384-5p binding site within the 3′ untranslational region of PIK3CD. These results show that miR-384-5p, an important protecting factor, plays a significant role in cardioprotection by regulating PIK3CD in myocardial ischemia.     

Diagnostic and mechanistic values of microRNA-130a and microRNA-203 in patients with papillary thyroid carcinoma

This research was determined to unearth the diagnostic values and the effects of microRNA (miR)-130a and miR-203 on cell proliferation and apoptosis of papillary thyroid carcinoma (PTC). Expression of miR-130a and miR-203 were evaluated and were subjected to correlation analysis. The diagnostic values of miR-130a and miR-203 and their associations with clinicopathological characteristics of patients with PTC were measured. The expression levels of miR-130a and miR-203 in K1, IHH4, TPC-1, and BCPAP cells together with Nthy-ori 3-1 cells were measured. Cells were transfected with miR-130a mimics, miR-203 mimics, and coordinate of miR-130a mimics and miR-203 mimics. Cell growth, colony formation, and apoptosis were detected by cell counting kit-8 (CCK-8) assay, colony formation assay, and flow cytometry. PTC tissues had decreased miR-130a and miR-203 relative to adjacent normal tissues and normal thyroid tissue (both P < .05). miR-130a was in positive correlation with miR-203 (r = 0.754, P < .01). miR-130a was related with tumor infiltration and tumor stage while miR-203 was implicated in tumor stage and lymph-node metastasis. The area under the curve (AUC), sensitivity, as well as specificity for miR-130 in predicting PTC was 0.839, 74.5%, and 85.0% and those for miR-203 were 0.818, 73.7%, and 84.0%, respectively. PTC cells had lower expression of miR-130a and miR-203 than that in Nthy-ori 3-1 cells. After transfected miR-130a and miR-203 mimics in BCPAP and TPC-1 cells, both cells had increased miR-130a and miR-203, promoted cell apoptosis rate and decreased cell growth rate, and colony formation ability. After coordinately transfected with miR-130a mimics and miR-203 mimics, the cell growth and colony formation ability of PTC cells were restrained, and apoptosis of PTC cells was elevated (all P < .05). This study highlights that miR-130a and miR-203 have satisfactory diagnostic value in PTC and upregulated miR-130a and miR-203 can inhibit PTC cell growth and promote cell apoptosis.