Pulmonary microRNA expression profiling in an immature piglet model of cardiopulmonary bypass-induced acute lung injury

Bone mesenchymal stromal cell-derived small extracellular vesicles inhibit inflammation and ameliorate sepsis via delivery of microRNA-21a-5p

BACKGROUND AIMS

Sepsis is a potentially life-threatening disease that results from a severe systemic inflammatory response due to infection. Mesenchymal stromal cell-derived small extracellular vesicles (MSC sEVs) are able to transfer bioactive molecules and have been demonstrated to play an important role in the pathophysiological process of sepsis. Herein the authors aimed to investigate the potential role and downstream molecular mechanism of MSC sEVs in sepsis.

METHODS

MSC sEVs were acquired by ultracentrifugation and then injected into a cecal ligation and puncture mouse model. The efficacy of MSC sEVs in both in vitro and in vivo models of sepsis was evaluated.

RESULTS

MSC sEV therapy improved survival, reduced sepsis-induced inflammation, attenuated pulmonary capillary permeability and improved liver and kidney function in septic mice. In addition, the authors found that microRNA-21a-5p (miR-21a-5p) was highly enriched in MSC sEVs, could be transferred to recipient cells, inhibited inflammation and increased survival in septic mice. Furthermore, the authors demonstrated that MSC sEV miR-21a-5p suppressed inflammation by targeting toll-like receptor 4 and programmed cell death 4. The therapeutic efficacy of MSC sEVs was partially abrogated by transfection with miR-21a-5p inhibitors.

CONCLUSIONS

Collectively, the authors' data suggest that miR-21a-5p-bearing MSC sEVs may be a prospective and effective sepsis therapeutic strategy.

microRNA-145-5p attenuates acute lung injury via targeting ETS2

The protective effect of microRNA (miR)-145-5p in acute lung injury (ALI) has been discovered previously. Thus, in this study, we attempted to further investigate the mechanism of miR-145-5p in ALI through the downstream E26 transformation-specific proto-oncogene 2 (ETS2)/transforming growth factor β1 (TGF-β1)/Smad pathway. A lipopolysaccharide (LPS)-induced ALI rat model was established. The expression of miR-145-5p in ALI rat lung tissues was up-regulated. Afterward, pathological damage in the lung tissue, the wet/dry (W/D) ratio, apoptosis, and serum inflammatory factor contents were observed. miR-145-5p, ETS2, TGF-β1, Smad2/3, and phosphorylated Smad2/3 levels were measured in rats. miR-145-5p expression was down-regulated, ETS2 expression was up-regulated, and the TGF-β1/Smad pathway was activated in LPS-exposed rats. Overexpression of miR-145-5p inactivated the TGF-β1/Smad pathway and attenuated ALI, as reflected by relieved pathological damage, a decreased W/D ratio, reduced apoptosis, and suppressed inflammatory response. In contrast, loss of miR-145-5p or elevated ETS2 levels worsened ALI and activated the TGF-β1/Smad pathway. Moreover, elevation of ETS2 diminished miR-145-5p-mediated protection against ALI. Evidently, miR-145-5p negatively regulates ETS2 expression and inactivates the TGF-β1/Smad pathway to ameliorate ALI in rats.

MicroRNA-21 protects against sepsis-induced acute lung injury by targeting phosphatase and tensin homolog in mice

Introduction: Sepsis can cause acute lung injury (ALI), one of the leading causes of death in critically ill patients. The underlying mechanisms of sepsis-induced acute lung injury include excessive inflammation, oxidative stress, cell apoptosis, pulmonary edema, and lung tissue dysfunction. Recent studies have shown that miRNA-21 (miR-21) plays a vital role in sepsis-induced acute kidney injury. Relatively few studies have focused on the protective effects of ALI. This study aimed to determine the potential role of miR-21 in sepsis-induced ALI.

Methods: We performed quantitative real-time polymerase chain reaction in a septic mouse model induced by cecal ligation and puncture (CLP) and found that miR-21 expression was upregulated. We then transfected the miR-21 precursor to upregulate miR-21 expression and miR-21 inhibitor to downregulate miR-21 expression. The sham group was exposed only to the cecum. ALI was induced by CLP, and the pre-miR-21+ALI and anti-miR-21+ALI groups were treated with miR-21 precursor or miR-21 inhibitor in the caudal vein before CLP. Pre-miR-21+ALI+PTEN inhibition (Pre-miR-21+ALI+PI) and anti-miR-21+ALI+PTEN inhibition (Anti-miR-21+ALI+PI) groups were treated with PTEN inhibition into the caudal vein after miR-21 transfection. Inflammatory cytokines, oxidative stress indicators, lung tissue cell apoptosis, oxygenation index (OI), lung wet/dry weight ratio, and lung pathological changes in the lung were observed in each group.

Results: Compared with ALI mice, inflammatory response, oxidative stress indicators, lung tissue cell apoptosis, and the degree of lung injury were remarkably alleviated in Pre-miR-21+ALI mice and aggravated in Anti-miR-21+ALI mice. Western blot analysis showed that phosphatase and tensin homolog (PTEN) protein expression was decreased in CLP-treated mics. PTEN protein expression was decreased in the Pre-miR-21+ALI group but increased in the Anti-miR-21+ALI group. Moreover, the effect of miR-21 on anti-inflammatory, anti-oxidative stress, and anti-apoptosis enhanced after PTEN inhibition.

Conclusion: This study revealed that miR-21 has a protective effect in sepsis-induced ALI by regulating PTEN in mice.

LncRNA NEAT1 aggravates lipopolysaccharide-induced acute lung injury by regulating the miR-98-5p/TLR4 axis

Although long noncoding RNA nuclear paraspeckle assembly transcript 1 (NEAT1) was reported to be associated with acute lung injury (ALI), its specific mechanism has not been well studied. Mouse and cell ALI models were constructed by lipopolysaccharide (LPS). Cell viability was evaluated by 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di- phenytetrazoliumromide assay. Cell death was evaluated by lactate dehydrogenase release (LDH) detection kit and flow cytometry. The levels of cytokines in lung tissues lysates were detected by quantitative real-time PCR (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA). The expression of apoptosis-related markers was detected by Western blot. The relationship between NEAT1, miR-98-5p, and toll-like receptor 4 (TLR4) was determined by bioinformatics prediction, luciferase reporter assay, and RNA immunoprecipitation (RIP) assay. Rescue experiments were performed to determine the role of NEAT1/miR-98-5p/TLR4 in ALI. NEAT1 was significantly upregulated during ALI both in vitro and in vivo. NEAT1 knockdown efficiently attenuated LPS-induced ALI and reduced LPS-induced elevation of cytokines both in vitro and in vivo. NEAT1 negatively regulated miR-98-5p by directly sponging it, and TLR4 was a target of miR-98-5p. MiR-98-5p inhibition or TLR4 overexpression could obviously attenuate the protective effects of NEAT1 knockdown in LPS-treated A549 cells. Our study demonstrated that NEAT1 knockdown alleviated LPS-induced ALI by targeting the miR-98-5p/TLR4 axis.

Prospects for miR-21 as a Target in the Treatment of Lung Diseases

MicroRNA (miRNA/miR) is a class of small evolutionarily conserved non-coding RNA, which can inhibit the target gene expression at the post-transcriptional level and serve as significant roles in cell differentiation, proliferation, migration and apoptosis. Of note, the aberrant miR-21 has been involved in the generation and development of multiple lung diseases, and identified as a candidate of biomarker, therapeutic target, or indicator of prognosis. MiR-21 relieves acute lung injury via depressing the PTEN/Foxo1-TLR4/NF-κB signaling cascade, whereas promotes lung cancer cell growth, metastasis, and chemo/radio-resistance by decreasing the expression of PTEN and PDCD4 and promoting the PI3K/AKT transduction. The purpose of this review is to elucidate the potential mechanisms of miR-21 associated lung diseases, with an emphasis on its dual regulating effects, which will trigger novel paradigms in molecular therapy.

lncRNA CASC2 inhibits lipopolysaccharide‑induced acute lung injury via miR‑27b/TAB2 axis

Long non-coding RNA (lncRNA) cancer susceptibility candidate 2 (CASC2) has been reported to exert an important role in acute lung injury (ALI). The present study aimed to investigate the potential underlying mechanism of CASC2 in ALI progression. Reverse transcription-quantitative PCR was conducted to examine the expression of CASC2, microRNA (miR/miRNA)-27b and TGF-β activated kinase 1 and MAP3K7-binding protein 2 (TAB2) in A549 cells. Cell viability and apoptosis were analyzed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and flow cytometry. Enzyme-linked immunosorbent assay was used to measure the levels of inflammatory-related cytokines to assess the inflammatory response, including interleukin-1β (IL-1β), IL-6 and tumor necrosis factor α (TNF-α). The binding sites of miR-27b in CASC2 or TAB2 were predicted using LncBase or microT-CDS software, following which dual-luciferase reporter and RNA binding protein immunoprecipitation assays were performed to confirm the target relationship between miR-27b and CASC2 or TAB2. The protein expression of TAB2 was detected by western blotting. The decreased viability, and increased apoptosis and inflammatory responses were attenuated by the accumulation of CASC2 in lipopolysaccharide (LPS)-stimulated A549 cells. CASC2 could directly bind to miR-27b in A549 cells. CASC2 protected A549 cells from LPS-triggered injury by downregulating miR-27b. TAB2 was a target of miR-27b in A549 cells. The influence of miR-27b depletion was reversed by the silencing of TAB2 in an ALI cell model. CASC2 could increase the expression of TAB2 by serving as a competing endogenous RNA of miR-27b in A549 cells. Collectively, the results suggested that CASC2 attenuated LPS-induced injury in the ALI cell model by modulating the miR-27b/TAB2 axis.

Inhibition of miR-155 potentially protects against lipopolysaccharide-induced acute lung injury through the IRF2BP2-NFAT1 pathway

Sepsis-induced lung injury is a lethal complication with no effective treatment options, affecting millions of people worldwide. Oroxylin A (OroA) is a natural flavonoid with potent anticancer effects, but its modulating effect on inflammation through microRNAs (miRs) is not apparent. In this report, we investigated the target genes of the miR pathway mediated by OroA and assessed the potential for novel treatments of septic lung injury. An miR array screening and quantitative polymerase chain reaction identified that miR-155-5p could be a candidate regulated by OroA. Bioinformatics analysis indicated that interferon regulatory factor-2-binding protein-2 (IRF2BP2) might be a target of miR-155-5p, and this hypothesis was verified through reporter assays. In addition, an immunoprecipitation assay demonstrated that OroA increased the binding activity of IRF2BP2 to the nuclear factor of activated T-cells 1 (NFAT1), causing inducible nitric oxide synthase to cause an inflammatory reaction. Finally, the direct injection of short hairpin RNA (shRNA)-miR-155-5p into the bone marrow of mice ameliorated LPS-induced acute lung injury and inflammation in mice. Our results provide new mechanistic insights into the role of the OroA-induced miR-155-5p-IRF2BP2-NFAT1 axis in sepsis, demonstrating that direct bone marrow injection of lentivirus containing shRNA-155-5p could prove to be a potential future clinical application in alleviating sepsis-induced acute lung injury.

miR-21-KO Alleviates Alveolar Structural Remodeling and Inflammatory Signaling in Acute Lung Injury

Acute lung injury (ALI) is characterized by enhanced permeability of the air–blood barrier, pulmonary edema, and hypoxemia. MicroRNA-21 (miR-21) was shown to be involved in pulmonary remodeling and the pathology of ALI, and we hypothesized that miR-21 knock-out (KO) reduces injury and remodeling in ALI. ALI was induced in miR-21 KO and C57BL/6N (wildtype, WT) mice by an intranasal administration of 75 µg lipopolysaccharide (LPS) in saline (n = 10 per group). The control mice received saline alone (n = 7 per group). After 24 h, lung function was measured. The lungs were then excised for proteomics, cytokine, and stereological analysis to address inflammatory signaling and structural damage. LPS exposure induced ALI in both strains, however, only WT mice showed increased tissue resistance and septal thickening upon LPS treatment. Septal alterations due to LPS exposure in WT mice consisted of an increase in extracellular matrix (ECM), including collagen fibrils, elastic fibers, and amorphous ECM. Proteomics analysis revealed that the inflammatory response was dampened in miR-21 KO mice with reduced platelet and neutrophil activation compared with WT mice. The WT mice showed more functional and structural changes and inflammatory signaling in ALI than miR-21 KO mice, confirming the hypothesis that miR-21 KO reduces the development of pathological changes in ALI.

Inhibition of miR-221 alleviates LPS-induced acute lung injury via inactivation of SOCS1/NF-κB signaling pathway

The role of inflammation response has been well documented in the development of acute lung injury (ALI). However, little is known about the functions of miRNAs in the regulation of inflammation in ALI. The aim of this study was to explore the effects of miRNAs in the regulation of inflammation in ALI and to elucidate the biomolecular mechanisms responsible for these effects. The expression profiles of miRNAs in lung tissues from lipopolysaccharide (LPS)-induced ALI mice model were analyzed using a microarray. It was observed that microRNA-221-3p (miR-221) was significantly increased in lung tissues in ALI mice. The inhibition of miR-221 attenuated lung injury including decreased lung W/D weight ratio and lung permeability and survival rates of ALI mice, as well as apoptosis, whereas its agomir-mediated upregulation exacerbated the lung injury. Concomitantly, miR-221 inhibition significantly reduced LPS-induced pulmonary inflammation, while LPS-induced pulmonary inflammation was aggravated by miR-221 upregulation. Of note, suppressor of cytokine signaling-1 (SOCS1), an effective suppressor of the NF-κB signaling pathway, was found to be a direct target of miR-221 in RAW264.7 cells. Overexpression of SOCS1 by pcDNA-SOCS1 plasmids markedly reversed the miR-221 inhibition-mediated inhibitory effects on inflammation and apoptosis in LPS-treated RAW264.7 cells. Finally, it was found that miR-221 inhibition suppressed LPS induced the activation of the NF-κB signaling pathway, as demonstrated by downregulation of phosphorylated-IκBα, p-p65 and upregulation of IκBα, whilst miR-221 overexpression had an opposite result in ALI mice. Our findings demonstrate that inhibition of miR-221 can alleviate LPS-induced inflammation via inactivation of SOCS1/NF-κB signaling pathway in ALI mice.

Downregulated microRNA-27b attenuates lipopolysaccharide-induced acute lung injury via activation of NF-E2-related factor 2 and inhibition of nuclear factor κB signaling pathway

Acute lung injury (ALI) is a life-threatening, diffuse heterogeneous lung injury characterized by acute onset, pulmonary edema, and respiratory failure. Lipopolysaccharide (LPS) is a leading cause for ALI and when administered to a mouse it induces a lung phenotype exhibiting some of the clinical characteristics of human ALI. This study focused on investigating whether microRNA-27b (miR-27b) affects ALI in a mouse model established by LPS-induction and to further explore the underlying mechanism. After model establishment, the mice were treated with miR-27b agomir, miR-27b antagomir, or D-ribofuranosylbenzimidazole (an inhibitor of nuclear factor-E2-related factor 2 [Nrf2]) to determine levels of miR-27b, Nrf2, nuclear factor kappa-light-chain-enhancer of activated B cells nuclear factor κB (NF-κB), p-NF-κB, and heme oxygenase-1 (HO-1). The levels of interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) in bronchoalveolar lavage fluid (BALF) were determined. The results of luciferase activity suggested that Nrf2 was a target gene of miR-27b. It was indicated that the Nrf2 level decreased in lung tissues from ALI mice. The downregulation of miR-27b decreased the levels of IL-1β, IL-6, and TNF-α in BALF of ALI mice. Downregulated miR-27b increased Nrf2 level, thus enhancing HO-1 level along with reduction of NF-κB level as well as the extent of NF-κB phosphorylation in the lung tissues of the transfected mice. Pathological changes were ameliorated in LPS-reduced mice elicited by miR-27b inhibition. The results of this study demonstrate that downregulated miR-27b couldenhance Nrf2 and HO-1 expressions, inhibit NF-κB signaling pathway, which exerts a protective effect on LPS-induced ALI in mice.

MicroRNA dysregulation in lung injury: the role of the miR-26a/EphA2 axis in regulation of endothelial permeability

MicroRNAs (miRNAs) are noncoding RNAs that regulate gene expression in many diseases, although the contribution of miRNAs to the pathophysiology of lung injury remains obscure. We hypothesized that dysregulation of miRNA expression drives the changes in key genes implicated in the development of lung injury. To test our hypothesis, we utilized a model of lung injury induced early after administration of intratracheal bleomycin (0.1 U). Wild-type mice were treated with bleomycin or PBS, and lungs were collected at 4 or 7 days. A profile of lung miRNA was determined by miRNA array and confirmed by quantitative PCR and flow cytometry. Lung miR-26a was significantly decreased 7 days after bleomycin injury, and, on the basis of enrichment of predicted gene targets, it was identified as a putative regulator of cell adhesion, including the gene targets EphA2, KDR, and ROCK1, important in altered barrier function. Lung EphA2 mRNA, and protein increased in the bleomycin-injured lung. We further explored the miR-26a/EphA2 axis in vitro using human lung microvascular endothelial cells (HMVEC-L). Cells were transfected with miR-26a mimic and inhibitor, and expression of gene targets and permeability was measured. miR-26a regulated expression of EphA2 but not KDR or ROCK1. Additionally, miR-26a inhibition increased HMVEC-L permeability, and the disrupted barrier integrity due to miR-26a was blocked by EphA2 knockdown, shown by VE-cadherin staining. Our data suggest that miR-26a is an important epigenetic regulator of EphA2 expression in the pulmonary endothelium. As such, miR-26a may represent a novel therapeutic target in lung injury by mitigating EphA2-mediated changes in permeability.

MicroRNA-21 inhibits lipopolysaccharide-induced acute lung injury by targeting nuclear factor-κB

Acute lung injury (ALI) is a frequent, but severe complication following sepsis in patients with critical illness. The present study aimed to investigate the potential role of microRNA-21 (miR-21) in the regulation of inflammation in the ALI induced by lipopolysaccharide (LPS) in vitro and in vivo. The levels of inflammatory cytokines, tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β and IL-10, and the level of miR-21 expression were measured in the lungs of LPS-induced ALI rats and NR8383 alveolar macrophages (AMs). To confirm the regulatory effect of miR-21 in the inflammatory reactions of ALI, NR8383 cells were transfected with a mimic of miR-21 or an anti-miR-21 inhibitor, and the subsequent changes of the miR-21 level and the levels of inflammatory cytokines were detected. The underlying molecular mechanism was also investigated. LPS-induced ALI in rats resulted in significant overexpression of pro-inflammatory cytokines, TNF-α, IL-6 and IL-1β, and miR-21, but reduced the expression of the anti-inflammatory cytokine IL-10. LPS treatment also led to a higher expression level of miR-21 and increased secretion of pro-inflammatory cytokines in NR8383 cells in a time-dependent manner. Manipulation with the miR-21 mimic significantly suppressed the LPS-mediated induction of TNF-α, IL-6 and IL-1β in NR8383 cells, while that induction was upregulated when miR-21 expression was silenced via transfection with the anti-miR-21 inhibitor. Further mechanism experiments revealed that miR-21 regulates LPS-induced inflammation responses via the Toll-like receptor 4 and nuclear factor-κB (Nf-κB) signaling pathway. miR-21 negatively regulates inflammatory responses in LPS-induced ALI by targeting the NF-κB signaling pathway, providing further insight into the molecular mechanism of ALI progression.

Increased Atrial β-Adrenergic Receptors and GRK-2 Gene Expression Can Play a Fundamental Role in Heart Failure After Repair of Congenital Heart Disease with Cardiopulmonary Bypass

Surgeries to correct congenital heart diseases are increasing in Brazil and worldwide. However, even with the advances in surgical techniques and perfusion, some cases, especially the more complex ones, can develop heart failure and death. A retrospective study of patients who underwent surgery for correction of congenital heart diseases with cardiopulmonary bypass (CPB) in a university tertiary-care hospital that died, showed infarction in different stages of evolution and scattered microcalcifications in the myocardium, even without coronary obstruction. CPB is a process routinely used during cardiac surgery for congenital heart disease. However, CPB has been related to increased endogenous catecholamines that can lead to major injuries in cardiomyocytes. The mechanisms involved are not completely understood. The aim of this study was to evaluate the alterations induced in the β-adrenergic receptors and GRK-2 present in atrial cardiomyocytes of infants with congenital heart disease undergoing surgical repair with CPB and correlate the alterations with functional and biochemical markers of ischemia/myocardial injury. The study consisted of right atrial biopsies of infants undergoing surgical correction in HC-FMRPUSP. Thirty-three cases were selected. Atrial biopsies were obtained at the beginning of CPB (group G1) and at the end of CPB (group G2). Real-time PCR, Western blotting, and immunofluorescence analysis were conducted to evaluate the expression of β₁, β₂-adrenergic receptors, and GRK-2 in atrial myocardium. Cardiac function was evaluated by echocardiography and biochemical analysis (N-terminal pro-brain natriuretic peptide (NT-ProBNP), lactate, and cardiac troponin I). We observed an increase in serum lactate, NT-proBNP, and troponin I at the end of CPB indicating tissue hypoxia/ischemia. Even without major clinical consequences in cardiac function, these alterations were followed by a significant increase in gene expression of β₁ and β₂ receptors and GRK-2, suggesting that this is one of the mechanisms responsible for the exacerbated response of cardiomyocytes to circulating catecholamines. These alterations could explain the irreversible myocardial damage and lipid peroxidation of membranes classically attributed to catecholamine excess, observed in some infants who develop heart failure and postoperative death. Although other factors may be involved, this study confirms that CPB acts as a potent inducer of increased gene expression of β- adrenergic receptors and GRK-2, making the myocardium of these infants more susceptible to the effects of circulating endogenous catecholamines, which may contribute to the development of irreversible myocardial damage and death.

Serum TNF-α levels in children with congenital heart disease undergoing cardiopulmonary bypass: A cohort study in China and a meta-analysis of the published literature

OBJECTIVE

To investigate the changes in tumor necrosis factor alpha (TNF-α) serum levels after cardiopulmonary bypass (CPB) in children with congenital heart disease (CHD), followed by a meta-analysis to analyze the clinical value of TNF-α in CPB.

METHODS

Our cohort study enrolled 67 CHD children, assigned into off-pump group (n=32) and CPB group (n=35). The TNF-α serum levels in two groups were detected by ELISA before the operation (T1), at the end of the operation (0 hour, T2), and after 24 hours of the operation (T3). For meta-analysis, literature search was conducted to identify published case-control articles about the changes of TNF-α serum levels with CPB of CHD.

RESULTS

The TNF-α levels in CPB group were lower than that in the off-pump group at T3 (P=.006). TNF-α level at T3 was significantly lower than that at T1 and T2 (all P<.05). Meta-analysis results further confirmed that the TNF-α levels of CHD children were dramatically decreased at T3 as compared to that at T1 and T2 (both P<.001).

CONCLUSION

The TNF-α serum levels showed a transient and dramatic decline after 24 hours of CPB, and it may act as an important biological indicator for monitoring the efficacy of CPB in CHD children.

Artificial Organs 2015: A Year in Review

In this Editor's Review, articles published in 2015 are organized by category and briefly summarized. We aim to provide a brief reflection of the currently available worldwide knowledge that is intended to advance and better human life while providing insight for continued application of technologies and methods of organ Replacement, Recovery, and Regeneration. As the official journal of The International Federation for Artificial Organs, The International Faculty for Artificial Organs, the International Society for Rotary Blood Pumps, the International Society for Pediatric Mechanical Cardiopulmonary Support, and the Vienna International Workshop on Functional Electrical Stimulation, Artificial Organs continues in the original mission of its founders "to foster communications in the field of artificial organs on an international level." Artificial Organs continues to publish developments and clinical applications of artificial organ technologies in this broad and expanding field of organ Replacement, Recovery, and Regeneration from all over the world. We take this time also to express our gratitude to our authors for providing their work to this journal. We offer our very special thanks to our reviewers who give so generously of their time and expertise to review, critique, and especially provide meaningful suggestions to the author's work whether eventually accepted or rejected. Without these excellent and dedicated reviewers, the quality expected from such a journal could not be possible. We also express our special thanks to our Publisher, John Wiley & Sons for their expert attention and support in the production and marketing of Artificial Organs. We look forward to reporting further advances in the coming years.

MicroRNA-7 Deficiency Ameliorates the Pathologies of Acute Lung Injury through Elevating KLF4

Recent evidence showed that microRNA-7 (miR-7) played an important role in the pathologies of lung-related diseases. However, the potential role of miR-7 in acute lung injury (ALI) still remains poorly understood. Here, we assessed the effect of miR-7 deficiency on the pathology of ALI. We, first, found that the expression of miR-7 was upregulated in lung tissue in murine LPS-induced ALI model. Notably, we generated miR-7 knock down mice by using miRNA-Sponge technique and found that miR-7 deficiency could ameliorate the pathologies of lung as evidenced by accelerated body weight recovery, reduced level of bronchoalveolar lavage (BAL) proinflammatory cytokines and decreased number of BAL cells in ALI mice. Moreover, the proportion and number of various immune cells in BAL, including innate immune cell F4/80⁺ macrophages, γδT cells, NK1.1⁺ T cells, and CD11c⁺DCs, as well as adaptive immune cell CD4⁺ T cells and CD8⁺ T cells, also significantly changed, respectively. Mechanistic evidence showed that KLF4, a target molecule of miR-7, was upregulated in lung tissues in ALI model, accompanied by altered transduction of NF-κB, AKT, and ERK pathway. These data provided a previously unknown role of miR-7 in pathology of ALI, which could ultimately aid the understanding of development of ALI and the development of new therapeutic strategies against clinical inflammatory lung diseases.

Airway smooth muscle inflammation is regulated by microRNA-145 in COPD

Chronic obstructive pulmonary disease (COPD) is a common, highly debilitating disease of the airways, primarily caused by smoking. Chronic inflammation and structural remodelling are key pathological features of this disease, in part caused by the aberrant function of airway smooth muscle (ASM) cells under the regulation of transforming growth factor (TGF)-β. miRNA are short, noncoding gene transcripts involved in the negative regulation of specific target genes, through their interactions with mRNA. Previous studies have proposed that mRNA-145 (miR-145) may interact with SMAD3, an important downstream signalling molecule of the TGF-β pathway. TGF-β was used to stimulate primary human ASM cells isolated from healthy nonsmokers, healthy smokers and COPD patients. This resulted in a TGF-β-dependent increase in CXCL8 and IL-6 release, most notably in the cells from COPD patients. TGF-β stimulation increased SMAD3 expression, only in cells from COPD patients, with a concurrent increased miR-145 expression. Regulation of miR-145 was found to be negatively controlled by pathways involving the MAP kinases, MEK-1/2 and p38 MAPK. Subsequent, overexpression of miR-145 (using synthetic mimics) in ASM cells from patients with COPD suppressed IL-6 and CXCL8 release, to levels comparable to the nonsmoker controls. Therefore, this study suggests that miR-145 negatively regulates pro-inflammatory cytokine release from ASM cells in COPD by targeting SMAD3.

Characteristics of microRNAs and their potential relevance for the diagnosis and therapy of the acute respiratory distress syndrome: from bench to bedside

Acute respiratory distress syndrome (ARDS) is a complex disease associated with high morbidity and mortality. Biomarkers and specific pharmacologic treatment of the syndrome are lacking. MicroRNAs (miRNAs) are small (∼ 19-22 nucleotides) noncoding RNA molecules whose function is the regulation of gene expression. Their uncommon biochemical characteristics (eg, their resistance to degradation because of extreme temperature and pH fluctuations, freeze-thaw cycles, long storage times in frozen conditions, and RNAse digestion) and their presence in a wide range of different biological fluids and the relatively low number of individual miRNAs make these molecules good biomarkers in different clinical conditions. In addition, miRNAs are suitable therapeutic targets as their expression can be modulated by different available strategies. The aim of the present review is to offer clinicians a global perspective of miRNA, covering their structure and nomenclature, biogenesis, effects on gene expression, regulation of expression, and features as disease biomarkers and therapeutic targets, with special attention to ARDS. Because of the early stage of research on miRNAs applied to ARDS, attention has been focused on how knowledge sourced from basic and translational research could inspire future clinical studies.

MicroRNA Regulation of Acute Lung Injury and Acute Respiratory Distress Syndrome

The acute respiratory distress syndrome (ARDS), a severe form of acute lung injury (ALI), is a very common condition associated with critically ill patients, which causes substantial morbidity and mortality worldwide. Despite decades of research, effective therapeutic strategies for clinical ALI/ARDS are not available. In recent years, microRNAs (miRNAs), small non-coding molecules have emerged as a major area of biomedical research as they post-transcriptionally regulate gene expression in diverse biological and pathological processes, including ALI/ARDS. In this context, this present review summarizes a large body of evidence implicating miRNAs and their target molecules in ALI/ARDS originating largely from studies using animal and cell culture model systems of ALI/ARDS. We have also focused on the involvement of miRNAs in macrophage polarization, which play a critical role in regulating the pathogenesis of ALI/ARDS. Finally, the possible future directions that might lead to novel therapeutic strategies for the treatment of ALI/ARDS are also reviewed. J. Cell. Physiol. 231: 2097-2106, 2016. © 2016 Wiley Periodicals, Inc.

Synbiotics suppress the release of lactate dehydrogenase, promote non-specific immunity and integrity of jejunum mucosa in piglets

The aim of our experiment was to study how synbiotics are able to deal with the problems of post‐weaning piglets. Lactobacillus plantarum – Biocenol^TM LP96 (CCM 7512), Lactobacillus fermentum – Biocenol^TM LF99 (CCM 7514) and flaxseed (rich in n‐3 polyunsaturated fatty acids) were administered to 36 conventional piglets from a problematic breed with confirmed presence of enterotoxigenic Escherichia coli and Coronavirus. The experimental piglets were supplied with probiotic cheeses and crushed flax‐seed in the period starting 10 days before weaning and lasting up to 14 days post‐weaning. Piglets in the control group were supplied only control cheese. The impact of such additives on the release of lactate dehydrogenase (LDH; spectroscopic and electrophoretic assay), alteration of immunity (index of metabolic activity), jejunum histology (light microscopy), and health of conventional piglets from a problematic breed (monitoring of hematology, consistency and moisture of feces and body temperature) were examined. We found significant decrease in LDH leakage in the blood serum and tissue extracts, indicating better cell membrane integrity in the individual organs of animals. Probiotics and flaxseed applied together seem to be a good source of nutrients to improve the immune status and the integrity of jejunum mucosa during infection. © 2015 Japanese Society of Animal Science