RETRACTED: LncRNA MALAT1 regulates sepsis-induced cardiac inflammation and dysfunction via interaction with miR-125b and p38 MAPK/NFκB

Effect of standard intravenous immunoglobulin therapy on Kawasaki disease predicted by long non-coding ribonucleic acid small nucleolar RNA host gene 5 and microRNA-27a

BACKGROUND

Kawasaki disease, an acute systemic small- and medium-vessel vasculitis, is mostly detected in children under 5 years old.

OBJECTIVE

We aimed to explore the predictive value of long non-coding ribonucleic acid small nucleolar RNA host gene 5 (SNHG5) and microRNA (miRNA)-27a for the effect of standard intravenous immunoglobulintherapy on children with Kawasaki disease.

METHODS

The study included 182 children undergoing standard intravenous immunoglobulin therapy for Kawasaki disease and another 182 healthy children receiving physical examinations as a control group. LncRNA SNHG5 and miRNA-27a expression levels were determined at admission.

RESULTS

The ineffective group had higher levels of interleukin-6, C-reactive protein, procalcitonin, lncRNA SNHG5, and miRNA-27a and Kobayashi score than those of the effective group (P < 0.05). Multivariate regression analysis showed that Kobayashi score, interleukin-6, C-reactive protein, procalcitonin, lncRNA SNHG5, and miRNA-27a were associated with the treatment outcomes (P < 0.05). LncRNA SNHG5 and miRNA-27a levels were positively correlated with Kobayashi score, interleukin-6, receiver operating characteristic and procalcitonin levels (r > 0, P < 0.05). High Kobayashi score and levels of interleukin-6, c-reactive roe, procalcitonin, lncRNA SNHG5, and miRNA-27a were influencing factors for treatment failure (odds ratio > 1, P < 0.05). The areas under the curves of lncRNA SNHG5, miRNA-27a, and their combination were 0.757, 0.766, and 0.831, respectively.

CONCLUSION

LncRNA SNHG5 and miRNA-27a are highly expressed in children with Kawasaki disease, and their levels are closely correlated with the efficacy of standard immunoglobulin therapy.

Simulating the clinical manifestations and disease progression of human sepsis: A monobacterial injection approach for animal modeling

Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection, with great clinical heterogeneity, high morbidity, and high mortality. At the same time, there are many kinds of infection sources, the pathophysiology is very complex, and the pathogenesis has not been fully elucidated. An ideal animal model of sepsis can accurately simulate clinical sepsis and promote the development of sepsis-related pathogenesis, treatment methods, and prognosis. The existing sepsis model still uses the previous Sepsis 2.0 modelling standard, which has some problems, such as many kinds of infection sources, poor repeatability, inability to take into account single-factor studies, and large differences from clinical sepsis patients. To solve these problems, this study established a new animal model of sepsis. The model uses intravenous tail injection of a single bacterial strain, simplifying the complexity of multibacterial infection, and effectively solving the above problems.

LncRNA MALAT1 signaling pathway and clinical applications in overcome on cancers metastasis

In spite of its high mortality rate and difficulty in finding a cure, scientific advancements have contributed to a reduction in cancer-related fatalities. Aberrant gene expression during carcinogenesis emphasizes the importance of targeting the signaling networks that control gene expression in cancer treatment. Long noncoding RNAs (lncRNAs), which are transcribed RNA molecules that play a role in gene expression regulation, are a recent innovative therapeutic approach for diagnosing and treating malignancies. MALAT1, a well-known lncRNA, functions in gene expression, RNA processing, and epigenetic control. High expression levels of MALAT1 are associated with several human disorders, including metastasis, invasion, autophagy, and proliferation of cancer cells. MALAT1 affects various signaling pathways and microRNAs (miRNAs), and this study aims to outline its functional roles in cancer metastasis and its interactions with cellular signaling pathways. Moreover, MALAT1 and its interactions with signaling pathways can be promising target for cancer treatment.

LncRNA NEAT-2 regulate the function of endothelial progenitor cells in experimental Sepsis model

BACKGROUND

Sepsis is a life-threatening disease with a limited effectiveness and the potential mechanism remains unclear. LncRNA NEAT-2 is reported to be involved in the regulation of cardiovascular disease. This study aimed to investigate the function of NEAT-2 in sepsis.

METHODS

We built sepsis animal model with Male Balb/C mice induced by cecal ligation and puncture (CLP). A total of 54 mice were randomly assigned into eight groups: sham operation group (n = 18), CLP group (n = 18), CLP plus si-control group (n = 3), CLP plus si-NEAT2 group (n = 3), CLP plus mimic control group (n = 3), CLP plus miR-320 group (n = 3), CLP plus normal saline group (n = 3), and normal control group (n = 3). The number of peripheral endothelial progenitor cells (EPCs), the expression level of NEAT-2 and miR-320 were detected during progression of sepsis, as well as the number of peripheral EPCs and level of TNF-α, IL-6, VEGF, ALT, AST and Cr. In addition, the function of EPCs was evaluated after NEAT-2 knockdown and miR-320 overexpression in vitro.

RESULTS

The number of circulating EPCs increased significantly in sepsis. NEAT-2 expression was significantly increased in the progress of sepsis, accompanied with miR-320 downregulated. NEAT-2 knockdown and miR-320 overexpression attenuated hepatorenal function and increased cytokines in sepsis. Moreover, NEAT-2 knockdown and miR-320 overexpression decreased the proliferation, migration and angiogenesis of endothelial progenitor cells in vitro.

CONCLUSIONS

LncRNA-NEAT2 regulated the number and function of endothelial progenitor cells via miR-320 in sepsis, which may contribute to the development of novel potential clinical therapy for sepsis.

m6A-mediated upregulation of miRNA-193a aggravates cardiomyocyte apoptosis and inflammatory response in sepsis-induced cardiomyopathy via the METTL3/ miRNA-193a/BCL2L2 pathway

The impact of N6-methyladenosine (m6A) modification on pri-miRNA in sepsis-induced cardiomyopathy (SICM), and its underlying regulatory mechanism, have not been fully elucidated. We successfully constructed a SICM mice model through cecal ligation and puncture (CLP). In vitro, a lipopolysaccharide (LPS)-induced HL-1 cells model was also established. The results showed that sepsis frequently resulted in excessive inflammatory response concomitant with impaired myocardial function in mice exposed to CLP, as indicated by decreases in ejection fraction (EF), fraction shortening (FS), and left ventricular end diastolic diameters (LVDd). miR-193a was enriched in CLP mice heart and in LPS-treated HL-1 cells, while overexpression of miR-193a significantly increased the expression levels of cytokines. Sepsis-induced enrichment of miR-193a significantly inhibited cardiomyocytes proliferation and enhanced apoptosis, while this was reversed by miR-193a knockdown. Furthermore, under our experimental conditions, enrichment of miR-193a in SICM could be considered excessively maturated on pri-miR-193a by enhanced m6A modification. This modification was catalyzed by sepsis-induced overexpression of methyltransferase-like 3 (METTL3). Moreover, mature miRNA-193a bound to a predictive sequence within 3'UTRs of a downstream target, BCL2L2, which was further validated by the observation that the BCL2L2-3'UTR mutant failed to decrease luciferase activity when co-transfected with miRNA-193a. The interaction between miRNA-193a and BCL2L2 resulted in BCL2L2 downregulation, subsequently activating the caspase-3 apoptotic pathway. In conclusion, sepsis-induced miR-193a enrichment via m6A modification plays an essential regulatory role in cardiomyocyte apoptosis and inflammatory response in SICM. The detrimental axis of METTL3/m6A/miR-193a/BCL2L2 is implicated in the development of SICM.

Parecoxib attenuates inflammation injury in septic H9c2 cells by regulating the MAPK signaling pathway

Parecoxib, a non-steroidal anti-inflammatory drug, has been reported to possess protective effects against sepsis. However, its detailed role and underlying mechanisms in septic cardiomyopathy remain unclear. Therefore, the goal of the present study was to clarify the function and to investigate the mechanisms of parecoxib in lipopolysaccharide (LPS)-treated H9c2 rat cardiomyocytes. TNF-α, IL-1β and IL-6 expression levels in parecoxib-treated H9c2 cells stimulated with LPS were assessed using ELISA. Parecoxib-treated H9c2 cells stimulated with LPS were tested for viability using the Cell Counting Kit-8 assay. Western blotting analysis and 5-ethynyl-2'-deoxyuridine were used to evaluate cell proliferation. Apoptosis was assessed using TUNEL and western blotting. To assess the protein expression of the MAPK signaling pathway, western blotting was performed. The data showed that parecoxib significantly and dose-dependently reduced the inflammatory responses of LPS-treated H9c2 cells. Parecoxib also significantly and dose-dependently increased the proliferation and inhibited the apoptosis of LPS-treated H9c2 cells. In addition, parecoxib significantly suppressed the activation of the MAPK (p38, JNK and ERK) signaling pathway. The current study indicated that parecoxib could be a viable therapeutic option for septic cardiomyopathy.

Circulatory long noncoding RNAs (circulatory-LNC-RNAs) as novel biomarkers and therapeutic targets in cardiovascular diseases: Implications for cardiovascular diseases complications

Cardiovascular diseases (CVDs) are a group of disorders with major global health consequences. The prevalence of CVDs continues to grow due to population-aging and lifestyle modifications. Non-coding RNAs (ncRNAs) as key regulators of cell signaling pathways have gained attention in the occurrence and development of CVDs. Exosomal-lncRNAs (exos-lncRNAs) are emerging biomarkers due to their high sensitivity and specificity, stability, accuracy and accessibility in the biological fluids. Recently, circulatory and exos-based-lncRNAs are emerging and novel bio-tools in various pathogenic conditions. It is worth mentioning that dysregulation of these molecules has been found in different types of CVDs. In this regard, we aimed to discuss the knowledge gaps and suggest research priorities regarding circulatory and exos-lncRNAs as novel bio-tools and therapeutic targets for CVDs.

Long Noncoding RNA: A Novel Insight into the Pathogenesis of Acute Lung Injury

Acute lung injury (ALI) and its severe form, acute respiratory distress syndrome (ARDS), represent an acute stage of lung inflammation where the alveolar epithelium loses its functionality. ALI has a devastating impact on the population as it not only has a high rate of incidence, but also has high rates of morbidity and mortality. Due to the involvement of multiple factors, the pathogenesis of ALI is complex and is not fully understood yet. Long noncoding RNAs (lncRNAs) are a group of non-protein-coding transcripts longer than 200 nucleotides. Growing evidence has shown that lncRNAs have a decisive role in the pathogenesis of ALI. LncRNAs can either promote or hinder the development of ALI in various cell types in the lungs. Mechanistically, current studies have found that lncRNAs play crucial roles in the pathogenesis of ALI via the regulation of small RNAs (e.g., microRNAs) or downstream proteins. Undoubtedly, lncRNAs not only have the potential to reveal the underlying mechanisms of ALI pathogenesis but also serve as diagnostic and therapeutic targets for the therapy of ALI.

LncRNA-mRNA expression profile and functional network of vascular dysfunction in septic rats

BACKGROUND

We used microarrays to analyse the changes in long non-coding RNAs (lncRNAs) and mRNAs in aorta tissue in model rats with lipopolysaccharide-induced sepsis and determined the lncRNA-mRNA and lncRNA-miRNA-mRNA functional networks.

METHODS

Wistar rats were intraperitoneally injected with lipopolysaccharide, and the lncRNA and mRNA expression profiles in the aorta were evaluated using microarrays. The functions of the differentially expressed mRNAs were analysed using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses. We then constructed coding/non-coding co-expression and competing endogenous RNA networks to study the mechanisms related to sepsis in rats.

RESULTS

We identified 503 differentially expressed lncRNAs and 2479 differentially expressed mRNAs in the model rats with lipopolysaccharide-induced sepsis. Mitochondrial fission process 1 (MTFP1) was the most significantly down-regulated mRNA. Bioinformatics analysis showed that the significantly down-regulated mRNAs in the sepsis models were in pathways related to mitochondrial structure, function, and energy metabolism. Coding/non-coding co-expression and competing endogenous RNA analyses were conducted using 12 validated lncRNAs in combination with all mRNAs. The coding/non-coding co-expression analysis showed that the 12 validated lncRNAs were mainly regulatory factors for abnormal energy metabolism, including mitochondrial structure damage and aberrant mitochondrial dynamics. The competing endogenous RNA analysis revealed that the potential functions of these 12 lncRNAs might be related to the inflammatory response.

CONCLUSION

We determined the differentially expressed lncRNAs and mRNAs in the aorta of septic rats using microarrays. Further studies on these lncRNAs will help elucidate the mechanism of sepsis at the genetic level and may identify potential therapeutic targets.

Salidroside protects against intestinal barrier dysfunction in septic mice by regulating IL‑17 to block the NF‑κB and p38 MAPK signaling pathways

Sepsis is a systemic inflammatory response syndrome, mainly caused by infection or suspected infectious factors. The intestine is not only one of the most easily involved organs in the course of sepsis, but also the dynamic organ for the course of sepsis. The present study investigated the protective effect and mechanism of salidroside on intestinal barrier dysfunction of septic mice. Briefly, C57BL/6 mice were used to establish a septic model and then administered with salidroside. The ileum tissues of mice were examined by histopathological examination. Fluorescein isothiocyanate-dextran concentration was measured. IL-17, IL-6, IL-13 and TNF-α levels in ileum tissues and NF-κB and p38 MAPK activations were detected by ELISA and the expressions of NF-κB p65 and p38 MAPK protein with their phosphorylation and intestinal tight junction proteins were gauged by western blotting. The above assays were performed again to investigate the effect of anti-IL-17A and salidroside (160 mg/kg) alone or in combination. The septic model induced the ileum tissue injury, increased intestinal permeability and TNF-α, IL-17 and IL-6 levels, activated NF-κB and p38 MAPK pathways, promoted the expressions of NF-κB p65 and p38 MAPK and their phosphorylation, while suppressing the levels of IL-13 and intestinal tight junction proteins. Salidroside and anti-IL-17A partially reversed the above effects of septic model, which in combination further strengthened the reversing effect. Collectively, salidroside protected against intestinal barrier dysfunction in septic mice by downregulating IL-17 level to inhibit NF-κB and p38 MAPK signaling pathways, thus providing a new treatment direction.

Current understanding on long non-coding RNAs in immune response to COVID-19

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global pandemic threatening the lives and health of people worldwide. Currently, there are no effective therapies or available vaccines for COVID-19. The molecular mechanism causing acute immunopathological diseases in severe COVID-19 is being investigated. Long noncoding RNAs (lncRNAs) have been proven to be involved in many viral infections, such as hepatitis, influenza and acquired immune deficiency syndrome. Many lncRNAs present differential expression between normal tissue and virus-infected tissue. However, the role of lncRNAs in SARS-CoV-2 infection has not been fully elucidated. This study aimed to review the relationship between lncRNAs and viral infection, interferon and cytokine storms in COVID-19, hoping to provide novel insights into promising targets for COVID-19 treatment.

Are Antisense Long Non-Coding RNA Related to COVID-19?

Fighting external pathogens relies on the tight regulation of the gene expression of the immune system. Ferroptosis, which is a distinct form of programmed cell death driven by iron, is involved in the enhancement of follicular helper T cell function during infection. The regulation of RNA is a key step in final gene expression. The present study aimed to identify the expression level of antisense lncRNAs (A2M-AS1, DBH-AS1, FLVCR1-DT, and NCBP2AS2-1) and FLVCR1 in COVID-19 patients and its relation to the severity of the disease. COVID-19 patients as well as age and gender-matched healthy controls were enrolled in this study. The expression level of the antisense lncRNAs was measured by RT-PCR. Results revealed the decreased expression of A2M-AS1 and FLVCR1 in COVID-19 patients. Additionally, they showed the increased expression of DBH-AS1, FLVCR1-DT, and NCBP2AS2. Both FLVCR1-DT and NCBP2AS2 showed a positive correlation with interleukin-6 (IL-6). DBH-AS1 and FLVCR1-DT had a significant association with mortality, complications, and mechanical ventilation. A significant negative correlation was found between A2M-AS1 and NCBP2AS2-1 and between FLVCR1 and FLVCR1-DT. The study confirmed that the expression level of the antisense lncRNAs was deregulated in COVID-19 patients and correlated with the severity of COVID-19, and that it may have possible roles in the pathogenesis of this disease.

LNC-ZNF33B-2:1 gene rs579501 polymorphism is associated with organ dysfunction and death risk in pediatric sepsis

Background: Sepsis is a severe systemic reaction disease induced by bacteria and virus invading the bloodstream and subsequently causing multiple systemic organ dysfunctions. For example, the kidney may stop producing urine, or the lungs may stop taking in oxygen. Recent studies have shown that long non-coding RNAs (lncRNAs) are related to the dysfunction of organs in sepsis. This study aims to screen and validate the sepsis-associated lncRNAs and their functional single nucleotide polymorphisms (SNPs).

Result: Unconditional multiple logistic regression based on the recessive model (adjusted odds ratio = 2.026, 95% CI = 1.156–3.551, p = 0.0136) showed that patients with the CC genotype of rs579501 had increased risk of sepsis. Stratification analysis by age and gender indicated that patients with the rs579501 CC genotype had higher risk of sepsis among children aged &lt;12 months (adjusted odds ratio = 2.638, 95% CI = 1.167–5.960, p = 0.0197) and in male patients (adjusted odds ratio = 2.232, 95% CI = 1.127–4.421, p = 0.0213). We also found a significant relationship between rs579501 and severe sepsis risk (CC versus AA/AC: adjusted odds ratio = 2.466, 95% CI = 1.346–4.517, p = 0.0035). Stratification analysis for prognosis and number of organ dysfunctions demonstrated that the rs579501 CC genotype increased non-survivors’ risk (adjusted odds ratio = 2.827, 95% CI = 1.159–6.898, p = 0.0224) and one to two organs with dysfunction risk (adjusted odds ratio = 2.253, 95% CI = 1.011–5.926, p = 0.0472).

Conclusion: Our findings showed that the lnc-ZNF33B-2:1 rs579501 CC genotype increases the susceptibility to sepsis. From the medical perspective, the lnc-ZNF33B-2:1 rs579501 CC genotype could be serving as a biochemical marker for sepsis.

Nonalcoholic Fatty Liver Hepatocyte-Derived lncRNA MALAT1 Aggravates Pancreatic Cell Inflammation via the Inhibition of Autophagy by Upregulating YAP

Background

Acute pancreatitis (AP) is one of the most common gastrointestinal disorders, which causes death with a high mortality rate of about 30%. The study aims to identify whether the nonalcoholic fatty liver disease (NAFLD)-derived lncRNA MALAT1 participates in the inflammation of pancreatic cell and its potential mechanism.

Methods

The NAFLD cell model was constructed by treating HepG2 cells with FFA. The in vitro model of acute pancreatitis (AP) was established by the administration of caerulein on AR42J cells. MALAT1 and si-MALAT1 were transfected into pancreatic cells, and then exosomes were collected from the NAFLD cell model and then were cocultured with AR42J cells. Transmission electron microscopy was used to observe the morphology of exosomes. Oil Red O staining was applied to reveal the lipid deposition. The triglyceride, IL-6, and TNF-α levels were detected using ELISA. The MALAT1 level in exosomes was detected by qRT-PCR. The CD9, CD63, CD81, and CYP2E1, LC3II, and LC3I levels were detected by western blot.

Results

MALAT1 was upregulated in NAFLD-derived exosomes and increased the levels of IL-6 and TNF-α in pancreatic cells. NAFLD-derived exosomes inhibited YAP phosphorylation, decreased the levels of IL-6 and TNF-α, and reduced the ratio of LC3II/LC3I protein in pancreatic cells. Silencing MALAT1 significantly returned the inhibitory effect of NAFLD on hippo-YAP pathway. YAP1 signal transduction inhibitor CA3 reversed the decrease of LC3II/LC3I expression and the increase of IL-6 and TNF-α levels induced by MALAT1 in the AP cell model.

Conclusions

NAFLD-derived MALAT1 exacerbates pancreatic cell inflammation via inhibiting autophagy by upregulating YAP.

The human long noncoding RNAs CoroMarker, MALAT1, CDR1as, and LINC00460 in whole blood of individuals after controlled short-term exposure with ultrafine metal fume particles at workplace conditions, and in human macrophages in vitro

BACKGROUND

Short-term inhalation of occupationally relevant ultrafine zinc/copper (Zn/Cu) containing welding fumes has been shown to induce subclinical systemic inflammation, associated with an elevated risk for cardiovascular diseases. The involvement of noncoding RNAs (lncRNAs) in this setting is currently unknown. However, lncRNAs have been reported to fulfill essential roles in, e.g., cardiovascular diseases, inflammation, infectious diseases, and pollution-related lung disorders.

METHODS

In this study, the specific lncRNAs levels of the 4 lncRNAs CoroMarker, MALAT1, CDR1as and LINC00460 were determined by RT-qPCR in THP-1 macrophages exposed to Zn/Cu metal fume suspensions for 1, 2, and 4 hours in vitro. Furthermore, 14 subjects were exposed to Zn/Cu containing welding fumes (at 2.5 mg/m3) for 6 hours. Before, 6, 10, and 29 hours after exposure start, whole blood cell lncRNAs levels were determined by RT-qPCR.

RESULTS

In THP-1 macrophages, we observed a 2.3-fold increase of CDR1as at 1 h (Wilcoxon p = 0.03), a non-significant increase of CoroMarker at 1 h, and an increase of LINC00460 at 2 h (p = 0.03) and at 4 h (p = 0.06). In whole blood cells, we determined a non-significant upregulation of CDR1as at 6 h (p = 0.2), a significant downregulation of CoroMarker at 6 h (p = 0.04), and a significant upregulation of LINC00460 levels at 10 h (p = 0.04) and 29 h (p = 0.04). MALAT-1 remained unchanged in both settings.

CONCLUSION

The orientation of regulation of the lncRNAs is (except for CoroMarker) similar in the in vitro and in vivo experiments and in line with their described functions. Therefore, these results, e.g. the upregulation of the potential risk marker for cardiovascular diseases, CDR1as, contribute to understanding the underlying mechanisms of Zn/Cu-induced subclinical inflammation in metal workers.

Molecular Mechanism of Sevoflurane Preconditioning Based on Whole-transcriptome Sequencing of Lipopolysaccharide-induced Cardiac Dysfunction in Mice

ABSTRACT

Sevoflurane, a widely used inhalation anesthetic, has been shown to be cardioprotective in individuals with sepsis and myocardial dysfunction. However, the exact mechanism has not been completely explained. In this study, we performed whole-transcriptome profile analysis in the myocardium of lipopolysaccharide-induced septic mice after sevoflurane pretreatment. RNA transcriptome sequencing showed that 97 protein coding RNAs (mRNAs), 64 long noncoding RNAs (lncRNAs), and 27 microRNAs (miRNAs) were differentially expressed between the lipopolysaccharide and S_L groups. Functional enrichment analysis revealed that target genes for the differentially expressed mRNAs between the 2 groups participated in protein processing in the endoplasmic reticulum, antigen processing and presentation, and the mitogen-activated protein kinase signaling pathway. The bioinformatics study of differentially expressed mRNAs revealed that 13 key genes including Hsph1, Otud1, Manf, Gbp2b, Stip1, Gbp3, Hspa1b, Aff3, Med12, Kdm4a, Gatad1, Cdkn1a, and Ppp1r16b are related to the heart or inflammation. Furthermore, the competing endogenous RNA network revealed that 3 of the 13 key genes established the lncRNA-miRNA-mRNA network (ENSMUST00000192774 --- mmu-miR-7a-5p --- Hspa1b, TCONS_00188587 --- mmu-miR-204-3p --- Aff3 and ENSMUST00000138273 --- mmu-miR-1954 --- Ppp1r16b) may be associated with cardioprotection in septic mice. In general, the findings identified 11 potential essential genes (Hsph1, Otud1, Manf, Gbp2b, Stip1, Gbp3, Hspa1b, Aff3, Med12, Kdm4a, Gatad1, Cdkn1a, and Ppp1r16b) and mitogen-activated protein kinase signaling pathway involved in sevoflurane-induced cardioprotection in septic mice. In particular, sevoflurane may prevent myocardial injury by regulating the lncRNA-miRNA-mRNA network, including (ENSMUST00000192774-mmu-miR-7a-5p-Hspa1b, TCONS_00188587-mmu-miR-204-3p-Aff3, and ENSMUST00000138273-mmu-miR-1954-Ppp1r16b networks), which may be a novel mechanism of sevoflurane-induced cardioprotection.

Protective Role of lncRNA TTN-AS1 in Sepsis-Induced Myocardial Injury Via miR-29a/E2F2 Axis

OBJECTIVE

Approximately 50% of patients with sepsis encounter myocardial injury. The mortality of septic patients with cardiac dysfunction (approx. 70%) is much higher than that of patients with sepsis only (20%). A large number of studies have suggested that lncRNA TTN-AS1 promotes cell proliferation in a variety of diseases. This study delves into the function and mechanism of TTN-AS1 in sepsis-induced myocardial injury in vitro and in vivo.

METHODS

LPS was used to induce sepsis in rats and H9c2 cells. Cardiac function of rats was assessed by an ultrasound system. Myocardial injury was revealed by hematoxylin-eosin (H&E) staining. Gain and loss of function of TTN-AS1, miR-29a, and E2F2 was achieved in H9c2 cells before LPS treatment. The expression levels of inflammatory cytokines and cTnT were monitored by ELISA. The expression levels of cardiac enzymes as well as reactive oxygen species (ROS) activity and mitochondrial membrane potential (MMP) were measured using the colorimetric method. The expression levels of TTN-AS1, miR-29a, E2F2, and apoptosis-related proteins were measured by RT-qPCR and/or western blotting. The proliferation and apoptosis of H9c2 cells were separately detected by CCK-8 and flow cytometry. Luciferase reporter assay was used to verify the targeting relationships among TTN-AS1, miR-29a and E2F2, and RIP assay was further used to confirm the binding between miR-29a and E2F2.

RESULTS

TTN-AS1 was lowly expressed, while miR-29a was overexpressed in the cell and animal models of sepsis. Overexpression of TTN-AS1 or silencing of miR-29a reduced the expression levels of CK, CK-MB, LDH, TNF-B, IL-1B, and IL-6 in the supernatant of LPS-induced H9c2 cells, attenuated mitochondrial ROS activity, and enhanced MMP. Consistent results were observed in septic rats injected with OE-TTN-AS1. Knockdown of TTN-AS1 or overexpression of miR-29a increased LPS-induced inflammation and injury in H9c2 cells. TTN-AS1 regulated the expression of E2F2 by targeting miR-29a. Overexpression of miR-29a or inhibition of E2F2 abrogated the suppressive effect of TTN-AS1 overexpression on myocardial injury.

CONCLUSION

This study indicates TTN-AS1 attenuates sepsis-induced myocardial injury by regulating the miR-29a/E2F2 axis and sheds light on lncRNA-based treatment of sepsis-induced cardiomyopathy.

LncRNA MALAT1 promotes tenogenic differentiation of tendon-derived stem cells via regulating the miR-378a-3p/MAPK1 axis

Tendinopathy is a type of chronic injury caused by repeated pulling. Previous studies have reported that long non-coding RNA MALAT1 (MALAT1) regulates a variety of genes affecting bone metabolism. This study aimed to explore the role of the MALAT1 in tendon injury in vivo and in vitro. Human tendon-derived stem cells (TDSCs) were treated with TGF β1. Eighteen Sprague-Dawley rats were used to establish the tendinopathy animal model. Sirius Red staining and colorimetric assays were conducted to analyze the collagen content. RT-qPCR was performed to measure the mRNA levels. Western blotting was performed to measure the MAPK1 protein levels. Additionally, hematoxylin and eosin (HE) and immunohistochemical staining were used to analyze the cell number and the content of collagen type 1 and Thbs, respectively. MALAT1 expression was upregulated in TGF β1 treated TDSCs, and MALAT1 knockdown downregulated Scleraxis, Mohawk homeobox, Collagen 1A1, Fibromodulin, Matrix metallopeptidase 3, and Thrombospondin 4 in TGF β1 treated TDSCs. Bioinformatics analysis showed that miR-378a-3p was the target of MALAT1 and MAPK1, and dual-luciferase reporter assay indicated that both MALAT1 and MAPK1 could bind to miR-378a-3p. Furthermore, miR-378a-3p knockdown reversed the effect of si-MALAT1, whereas overexpression of MAPK1 reversed the effect of the miR-378a-3p mimic. Finally, MALAT1 expression was downregulated in tendinopathy rats, and MALAT1 overexpression healed tendon injury in them. MALAT1 regulated the tenogenic differentiation of TDSCs by regulating the miR-378a-3p/MAPK1 axis. Our results therefore indicate that targeting the MALAT1/miR-378a-3p/MAPK1 axis may be a promising avenue for the treatment of tendinopathy.

LncRNA OIP5-AS1 inhibits the lipopolysaccharide-induced inflammatory response and promotes osteogenic differentiation of human periodontal ligament cells by sponging miR-92a-3p

Periodontitis is a chronic infectious disease that affects the oral health of adults. Long non-coding RNA OIP5 antisense RNA 1 (OIP5-AS1) has been reported to downregulated in the periodontal tissue of patients with periodontitis. Therefore, the study sought to look at the possible functions of OIP5-AS1 in periodontitis and the associated underlying mechanisms. In the present study, the expression level of OIP5-AS1 and microRNA-92a-3p were analyzed using reverse transcription-quantitative PCR. The levels of osteogenic proteins were determined using western blotting and inflammatory cytokines and oxidative stress were also examined. The proliferation of human periodontal ligament stem cells (hPDLSCs) was evaluated using MTT assays. Assay of osteogenic differentiation was undertaken by means of Alkaline phosphatase staining. The possible association between OIP5-AS1 and miR-92a-3p was determined applying dual-luciferase reporter assays and verified by RNA immunoprecipitation assay. We found that OIP5-AS1 was expressed at low levels in lipopolysaccharide (LPS)-stimulated hPDLSCs. OIP5-AS1 overexpression promoted proliferation and osteogenic differentiation ability and reduced LPS-induced inflammation in hPDLSCs. Furthermore, OIP5-AS1 directly targeted and reduced miR-92a-3p expression. The overexpression of miR-92a-3p partly abolished the effects of OIP5-AS1 on LPS-induced cell proliferation and osteogenic differentiation as well as inflammation in hPDLSCs. Collectively, the results indicated that OIP5-AS1 overexpression inhibited the LPS-induced inflammatory response and promoted the osteogenic differentiation of hPDLSCs by sponging miR-92a-3p. Thus, OIP5-AS1 is probably an essential objective for research during periodontitis treatment.

Polydatin Improves Sepsis-Associated Encephalopathy by Activating Sirt1 and Reducing p38 Phosphorylation

INTRODUCTION

Our previous study confirmed that polydatin (PD) can alleviate sepsis-induced multiorgan dysfunction (in the vascular endothelium, kidney, and small intestine) by activating Sirt1 and that PD protects against traumatic brain injury in rats via increased Sirt1 and inhibition of the p38-mediated mitogen-activated protein kinase (MAPK) pathway. We aim to investigate whether PD may also attenuate sepsis-associated encephalopathy (SAE).

METHODS

In this study, we constructed an SAE mouse model by cecal ligation and puncture (CLP) and measured Sirt1 protein activity, p38 phosphorylation, brain tissue pathological damage, pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6), mitochondrial function (mitochondrial membrane potential, ATP content, and reactive oxygen species), neurological function, and animal survival time. Sirt1 selective inhibitor Ex527 and p38 inhibitor SB203580 were used to explore the possible mechanism of PD in SAE.

RESULTS

We confirmed that PD inhibits neuroinflammation evidenced by reduced proinflammatory cytokines. In addition, PD protects mitochondria as demonstrated by restored mitochondrial membrane potential and adenosine triphosphate (ATP) content, and decreased reactive oxygen species (ROS) level. As we expected, p38 inhibition reduces neuroinflammation and mitochondrial damage. In contrast, Sirt1 inhibition aggravates cerebral cortex mitochondrial damage and neuroinflammation and promotes phosphorylation of p38. Mechanistically, PD treatment suppressed p38 phosphorylation and consequently reduced the neuroinflammatory response, and these effects were blocked by the Sirt selective inhibitor Ex527.

CONCLUSIONS

This study, to the best of our knowledge, is the first to demonstrate that PD alleviates SAE, at least partially, by upregulating Sir1-mediated neuroinflammation inhibition and mitochondrial function protection.

MALAT1 regulates PCT expression in sepsis patients through the miR‐125b/STAT3 axis

Background

Procalcitonin (PCT) is an important marker in diagnosing sepsis. However, some other diseases can also cause an increase in PCT. PCT still has some limitations in the clinical application of diagnosing sepsis. Therefore, it is of great significance to clarify the regulatory mechanism of PCT expression in sepsis and provide new therapeutic targets for sepsis.

Methods

Blood samples from clinical patients were collected, and peripheral blood monocytes were isolated. Bioinformatics was performed to find the ceRNA regulatory network of STAT3/PCT. MALAT1 and miR‐125b were detected by qRT‐PCR. MALAT1 was located by fluorescence in situ hybridization (FISH) in U937 cells, and the regulatory relationship between MALAT1, miR‐125b, and STAT3 was verified by double luciferase activity report and RNA pull‐down assay. U937 cells were transfected with miR‐125b, and the effects of the MALAT1/miR‐125b/STAT3 pathway on gene and protein secretion levels of PCT were verified by qRT‐PCR, western blot, and ELISA.

Results

In the serum of sepsis patients and lipopolysaccharide(LPS)‐induced U937 cells, MALAT1, STAT3, and PCT gene expression levels were significantly increased, while miR‐125b expression level was decreased. FISH results showed that the MALAT1 transcript was mainly located in the nucleus. The double luciferase activity report and RNA pull‐down assay results suggested a targeted regulatory relationship between MALAT1, miR‐125b, and STAT3. LPS‐induced U937 cells transfection with MALAT1 siRNA decreased STAT3 protein expression and phosphorylation level and the expression of PCT. Co‐transfection with miR‐125b inhibitor effectively reversed this phenomenon.

Conclusions

MALAT1 could upregulate the expressions of STAT3 and PCT by targeted adsorption of miR‐125b.

Exosome-Derived lncRNA NEAT1 Exacerbates Sepsis-Associated Encephalopathy by Promoting Ferroptosis Through Regulating miR-9-5p/TFRC and GOT1 Axis

Sepsis can cause sepsis-associated encephalopathy (SAE), but whether SAE was induced or exacerbated by ferroptosis remains unknown. In this study, the rat sepsis model was constructed using the cecal ligation and puncture method. The blood-brain barrier (BBB) permeability was measured by Evans blue dye (EBD) in vivo. The levels of ROS, Fe ion, MDA, GSH, and GPX4 were assessed by enzyme-linked immunosorbent assay (ELISA). The exosomes isolated from serum were cultured with bEnd.3 cells for the in vitro analysis. Moreover, bEnd.3 cells cultured with 100 μM FeCl3 (iron-rich) were to simulate ferroptosis stress. The cell viability was evaluated by Cell Counting Kit-8 (CCK-8) assay. A dual-luciferase reporter gene assay was performed to confirm the relationship between miR-9-5p with NEAT1, TFRC, and GOT1. In vivo, it is found that BBB permeability was damaged in model rats. Level of ROS, Fe ion, and MDA was increased, and level of GSH and GPX4 was decreased, which means ferroptosis was induced by sepsis. Exosome-packaged NEAT1 in serum was significantly upregulated in model rats. In vitro, it is found that NEAT1 functions as a ceRNA for miR-9-5p to facilitate TFRC and GOT1 expression. Overexpression of NEAT1 enhanced ferroptosis stress in bEnd.3 cells. Increased miR-9-5p alleviated sepsis-induced ferroptosis by suppressing the expression of TFRC and GOT1 both in vivo and in vitro. In conclusion, these findings suggest that sepsis induced high expression of serous exosome-derived NEAT1, and it might exacerbate SAE by promoting ferroptosis through regulating miR-9-5p/TFRC and GOT1 axis.

Long non-coding RNA growth arrest specific 5 is downregulated in sepsis-ALI and inhibits apoptosis by up-regulating miR-146a

Long non-coding RNA (lncRNA) growth arrest specific 5 (GAS5) and microRNA (miR)-146a both have inhibitory effects on LPS-induced inflammation, suggesting the crosstalk between them. In this study, the expression of GAS5 and miR-146a in patients with sepsis-induced acute lung injury (sepsis-ALI), sepsis patients without obvious complications (sepsis) and healthy controls were studied by RT-qPCR. The role of GAS5 in the expression and methylation of miR-146a in human bronchial epithelial cells (HBEpCs) were studied by RT-qPCR and methylation-specific PCR (MSP), respectively. Cell apoptosis was analyzed by flow cytometry. We found that GAS5 and miR-146a were downregulated in sepsis-ALI and the expression of these two were correlated. LPS induced the downregulation of GAS5 and miR-146a in HBEpCs. In HBEpCs, overexpression of GAS5 increased the expression levels of miR-146a and reduced the methylation of miR-146a gene. Under lipopolysaccharide (LPS) treatment, overexpression of GAS5 and miR-146a decreased the apoptotic rate of HBEpCs. Moreover, the combined overexpression of GAS5 and miR-146a showed stronger effects. Therefore, GAS5 is downregulated in sepsis-ALI and inhibits cell apoptosis by up-regulating the expression of miR-146a.

microRNA-124-3p attenuates myocardial injury in sepsis via modulating SP1/HDAC4/HIF-1α axis

Sepsis-induced cardiac dysfunction can lead to death in sepsis. In this case, we targeted to explore in detail the relative mechanism of microRNA (miR)-124-3p in sepsis-induced myocardial injury via the specific protein 1/histone deacetylase 4/hypoxia-inducing factor 1α (SP1/HDAC4/HIF-1α) axis. Septic rats were modeled by cecal ligation puncture while in vitro septic cardiomyocyte H9C2 were induced by lipopolysaccharide (LPS). miR-124-3p/SP1/HDAC4/HIF-1α expression levels in myocardial tissues of septic rats and LPS-treated H9C2 cells were measured. miR-124-3p overexpression and SP1 silencing assays were implemented on LPS-treated H9C2 cells to explore theirs actions in inflammation, oxidative stress and cell apoptosis. The interactions of miR-124-3p, SP1, and HDAC4 were testified. miR-124-3p was lowly expressed while SP1, HDAC4, and HIF-1α were highly expressed in sepsis. Upregulation of miR-124-3p ameliorated inflammation, oxidative stress, and apoptosis of LPS-treated H9C2 cells. Silencing SP1 improved LPS-induced damage to cardiomyocytes. miR-124-3p targeted SP1 and HDAC4 interacted with SP1. SP1 overexpression antagonized miR-124-3p upregulation-induced improvements in LPS-induced cardiomyocyte damage. This study illustrates that miR-124-3p improves myocardial injury in septic rats through targeted regulation of SP1 to mediate HDAC4/HIF-1α.

Long non-coding RNA muscleblind like splicing regulator 1 antisense RNA 1 (LncRNA MBNL1-AS1) promotes the progression of acute myocardial infarction by regulating the microRNA-132-3p/SRY-related high-mobility-group box 4 (SOX4) axis

Long non-coding RNA muscleblind like splicing regulator 1 antisense RNA 1 (LncRNA MBNL1-AS1) exerts vital role in various physiological processes. However, its functions in acute myocardial infarction (AMI) are not elucidated. AMI model was constructed using Wistar rats and it was found that LncRNA MBNL1-AS1 was upregulated in AMI model according to the quantitative real-time polymerase chain reaction (qRT-PCR) results. The left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LVEDP) and maximum rate of rise/fall of left ventricle pressure (±dp/dt max) were detected through hemodynamics test, which showed that knockdown of MBNL1-AS1 improved cardiac function in AMI model. Next, the myocardial infarction area was estimated by triphenyltetrazole chloride (TTC) staining, and the levels of cardiac troponin I (cTn-I) and creatine kinase-MB (CK-MB) were detected by enzyme-linked immunosorbent assay (ELISA) kit. The results revealed that silencing MBLN1-AS1 alleviated myocardial injury in AMI model. Additionally, MBNL1-AS1 knockdown inhibited apoptosis of myocardial cells and reduced the expression of apoptotic proteins. According to DIANA database and luciferase reporter assay, miR-132-3p was the direct target of MBNL1-AS1 and was negatively regulated by MBNL1-AS1. Furthermore, Targetscan database predicted that SRY-related high-mobility-group box 4 (SOX4) was the direct target of miR-132-3p and was regulated by MBNL1-AS1 through miR-132-3p. Moreover, overexpression of SOX4 partially eliminated effects of MBNL1-AS1 on myocardial cells. In conclusion, this investigation for the first time revealed that LncRNA MBNL1-AS1 was the potential target for treating AMI and expounded the underlying mechanisms of it.

The Anti-Inflammatory and Antiapoptotic Effects of Nicorandil in Antisepsis Cardiomyopathy

Objective

To observe the effect of nicorandil on septic rats and explore the possible mechanism of its myocardial protection, so as to provide theoretical basis for the treatment of septic cardiomyopathy.

Methods

Sixty male clean SD rats were selected as the research objects and randomly divided into 3 groups by random number method: sham operation group (sham group), cecal ligation and perforation group (CLP group), nicorandil treatment group (nicorandil+CLP group). After the operation, the nicorandil group was pumped with nicorandil diluent 1 ml/h (2 mg/kg/h) with a micropump for 6 hours. The sham group and CLP group were pumped with the same amount of normal saline 1 ml/h for a total of 6 hours. After 24 hours, the survival of the rats in each group was observed. The expression of troponin I (cTnI), tumor necrosis factor α (TNF-α), and interleukin-1β (IL-1β) in the serum was detected. Then, the ventricle was harvested for the observation of the pathological changes of myocardium. Quantitative real-time polymerase chain reaction and immunostaining were used to detect myocardial tissue apoptosis, and Western blot methods were used to detect protein expression changes in nuclear factor-κB (NF-κB) pathways.

Results

24 hours after operation, the survival rate of the rats in the CLP group was 60%. There was a large amount of necrosis of myocardial cells and inflammatory cell infiltration. The survival rate of rats in the nicorandil+CLP group was 75%. Compared with the CLP group, the necrosis of myocardial cells was reduced, and there was still a small amount of inflammatory cell infiltration. In the CLP group, myocardial inflammation and apoptosis were significant, and NF-κB pathway was activated. On the contrary, the NF-κB pathway in the nicorandil+CLP group was inhibited, and the expression of inflammatory factors and apoptosis factors was inhibited.

Conclusion

Nicorandil can reduce the release of inflammatory factors in septic rats, improve the inflammatory response, reduce myocardial damage, and play a myocardial protective effect. Its mechanism may be related to the inhibition of the activation of NF-κB signaling pathway.

Ginsenoside Rg3 alleviates septic liver injury by regulating the lncRNA TUG1/miR-200c-3p/SIRT1 axis

BACKGROUND

Studies have shown that ginsenoside R3 (Rg3) plays a protective role in sepsis-induced organ injuries and mitochondrial dysfunction. Long noncoding RNA (lncRNA) taurine-upregulated gene 1 (TUG1) is regarded as a regulator in sepsis. However, the association between TUG1 and Rg3 remains elusive.

METHODS

A sepsis mouse model was established by caecal ligation and puncture (CLP), and liver injury was induced by haematoxylin-eosin (H&E) staining. Lipopolysaccharide (LPS) was used to induce hepatocyte damage. The expression levels of TUG1, microRNA (miR)-200a-3p, and silencing information regulator 1 (SIRT1) were examined by quantitative real-time polymerase chain reaction (qRT-PCR) assays. Cell viability was monitored using the Cell Counting Kit-8 (CCK-8) assay. MitoSOX Red staining and CBIC2 (JC-1) dye were employed to detect mitochondrial reactive oxygen species (ROS) and mitochondrial transmembrane potential (MTP) levels, respectively. The interaction between miR-200a-3p and TUG1 or SIRT1 was confirmed via dual-luciferase reporter or RNA immunoprecipitation (RIP) assay.

RESULTS

Rg3 upregulated TUG1 expression in liver tissues of CLP mice and LPS-induced hepatocytes. Rg3 could activate autophagy to improve mitochondrial dysfunction in LPS-treated hepatocytes, which was partially reversed by TUG1 depletion or miR-200a-3p overexpression. Importantly, TUG1 targeted miR-200a-3p to activate the SIRT1/AMP-activated protein kinase (AMPK) pathway in LPS-treated hepatocytes. Moreover, gain of TUG1 ameliorated mitochondrial dysfunction in LPS-treated hepatocytes by sequestering miR-200a-3p.

CONCLUSION

Our study revealed that Rg3 increased TUG1 expression and reduced miR-200a-3p expression to stimulate the SIRT1/AMPK pathway, thereby enhancing autophagy to improve sepsis-induced liver injury and mitochondrial dysfunction.

LncRNA MALAT1-deficiency restrains lipopolysaccharide (LPS)-induced pyroptotic cell death and inflammation in HK-2 cells by releasing microRNA-135b-5p

Long non-coding RNAs (LncRNAs) participate in the regulation of chronic kidney disease (CKD), and acute kidney injury (AKI) is identified as an important risk factor for CKD. This study investigated the involvement of a novel LncRNA MALAT1 in regulating lipopolysaccharide (LPS)-induced cell pyroptosis and inflammation in the human renal tubular epithelial HK-2 cells. Here, the HK-2 cells were subjected to LPS (2 μg/mL) treatment to establish cellular AKI models in vitro, and we validated that LPS triggered NLRP3-mediated pyroptotic cell death, promoted cell apoptosis and inflammation-associated cytokines secretion to induce HK-2 cell injury. Then, a novel LncRNA MALAT1/miRNA (miRNA)-135b-5p axis was verified to rescue cell viability in LPS treated HK-2 cells by targeting NLRP3. Mechanistically, miRNA-135b-5p bound to LncRNA MALAT1, and LncRNA MALAT1 positively regulated NLRP3 through acting as RNA sponger for miRNA-135b-5p. Further gain- and loss-of-function experiments evidenced that both LncRNA MALAT1 ablation and miRNA-135b-5p overexpression reversed LPS-induced cell pyroptosis, apoptosis, and inflammation in the HK-2 cells, and the protective effects of LncRNA MALAT1 knock-down on LPS-treated HK-2 cells were abrogated by silencing miRNA-135b-5p. In general, our study firstly investigated the role of the LncRNA MALAT1/ miRNA-135b-5p/NLRP3 signaling cascade in regulating LPS-induced inflammatory death in HK-2 cells.

Assessment of Sumatriptan on Sepsis-Induced Kidney injury in the Cecal Ligation and Puncture Mice Model

Sepsis is a severe systemic inflammatory response with high mortality rate resulting from different microorganisms. Cytokines activation is essential for the immune response, but in painful conditions like sepsis, cytokines act as a double-edged sword and dysregulate immune response which is life-threatening owing to multiple organ dysfunction. The abnormality in 5-HT function is involved in pathological conditions like irritable bowel syndrome, inflammation, myocardial ischemia, itch and renal injury. Sumatriptan, a 5-HT_1B/1D agonist, has anti-inflammatory and anti-oxidative stress effects on animal models. This study was aimed to assess the effects of sumatriptan on kidney injury, the levels of pro-inflammatory cytokines and the percentage of survival in (CLP)-induced sepsis were examined.Cecal ligation and puncture (CLP) model was done on adult C57BL/6 male mice to induce Polymicrobial sepsis. Sumatriptan was injected intraperitoneally 1 h after the sepsis induction by CLP at doses of 0.1, 0.3, and 1 mg/kg in 3 treatment groups. To study the effect of sumatriptan on short-term survival, septic animals were detected 72 h after CLP. Serum levels of TNF-α, IL-1β, IL-6 and IL-10 were evaluated. To study sepsis-induced acute renal failure, kidney functional biomarkers and histopathological alterations were evaluated.Sumatriptan (0.3 mg/kg) administration significantly enhanced survival rate (P<0.01) compared to the CLP group. The beneficial effects of sumatriptan were related to a significant decrease in the pro-inflammatory cytokines and elevated level of IL-10. Sumatriptan presented protective effects on kidney biomarkers and histopathology assay.Anti-inflammatory effects of sumatriptan lead to decrease mortality rate and inflammatory cytokines in CLP induction sepsis in C57BL/6 mice.

LncRNA-Cox2 regulates macrophage polarization and inflammatory response through the CREB-C/EBPβ signaling pathway in septic mice

LncRNA-Cox2 has been reported to regulate macrophage polarization, and the activation of macrophages is a major participant in the pathogenesis of sepsis. Therefore, we explored whether lncRNA-Cox2 was involved in the progression of sepsis. In this study, we established a cecal ligation and puncture (CLP) mouse model and found that silencing lncRNA-Cox2 in CLP mice improved the 7-day survival rate, and alleviated the increase of blood bacterial burdens, systemic inflammatory response, and pulmonary dysfunction induced by CLP. Besides, interference with lncRNA-Cox2 declined the percentage of M1 macrophages and increased the percentage of M2 macrophages in the spleens of CLP mice. In vitro, the knockdown of lncRNA-Cox2 suppressed LPS-induced inflammation and M1 macrophage marker expression, and promoted M2 macrophage marker expression in primary peritoneal macrophages and RAW264.7 cells. Moreover, lncRNA-Cox2 induced CREB phosphorylation by binding to CREB, and increased phosphorylated-CREB enrichment in the C/EBPβ promoter region, so as to promote C/EBPβ transcription, thereby activating the CREB-C/EBPβ cascade. In addition, overexpressing lncRNA-Cox2 enhanced the effect of LPS on inflammation and macrophage polarization, which was reversed by treatment with 666-15 (an inhibitor of CREB). In conclusion, silencing lncRNA-Cox2 restrained the progression of sepsis in mice by modulating macrophage polarization and inflammatory response through suppressing CREB-C/EBPβ pathway.

Long noncoding RNA MAPKAPK5-AS1 promoted lipopolysaccharide-induced inflammatory damage in the myocardium by sponging microRNA-124-3p/E2F3

BACKGROUND

Myocardial dysfunction caused by sepsis (SIMD) leads to high mortality in critically ill patients. We investigated the function and mechanism of long non-coding RNA MAPKAPK5-AS1 (lncRNA MAPKAPK-AS1) on lipopolysaccharide (LPS)-induced inflammation response in vivo and in vitro.

METHOD

Male SD rats were utilized for in vivo experiments. Rat cardiomyocytes (H9C2) were employed for in vitro experiments. Western blotting was employed to measure protein expression, and RT-PCR was performed to measure mRNA expression of inflammation factors. TUNEL and flow cytometry were carried out to evulate cell apoptosis.

RESULT

The results showed that the expression of MAPKAPK5-AS1 was increased, while the expression of miR-124-3p was decreased in the inflammatory damage induced by LPS in vivo and in vitro. Knockdown of MAPKAPK5-AS1 reduced LPS-induced cell apoptosis and inflammation response, while overexpression of miR-124-3p weakened the effects of MAPKAPK5-AS1 knockdown on LPS-induced cell apoptosis and inflammation response. Moreover, miR-124-3p was identified as a downstream miRNA of MAPKAPK5-AS1, and E2F3 was a target of miR-214-3p. MAPKAPK5-AS1 knockdown increased the expression of miR-124-3p, while miR-124-3p overexpression reduced the expression of MAPKAPK5-AS1. In addition, miR-124-3p was found to downregulate E2F3 expression in H9C2 cells.

CONCLUSION

MAPKAPK5-AS1/miR-124-3p/E2F3 axis regulates LPS-related H9C2 cell apoptosis and inflammatory response.

Resveratrol alleviates sepsis-induced acute kidney injury by deactivating the lncRNA MALAT1/MiR-205 axis

INTRODUCTION

Resveratrol plays a protective role against sepsis development, and the long noncoding RNA (lncRNA) MALAT1 is an inflammation-relevant biomarker. This investigation attempted to reveal whether resveratrol attenuated inflammation of sepsis-induced acute kidney injury (AKI) by regulating MALAT1.

MATERIAL AND METHODS

In total 120 rats were divided into a control group (n = 20), a Sham group (n = 20), a sepsis group (n = 40) and a resveratrol group (n = 40), and serum levels of inflammatory cytokines and AKI biomarkers were determined. An equal number of rats under identical treatments were, additionally, tracked for their survival, and the serum level of lncRNA MALAT1 was measured by RT-PCR. Moreover, septic cell models were constructed by treating HK-2 cells with lipopolysaccharide (LPS), and tumor necrosis factor α (TNF-α), interleukin (IL)-1β, IL-6 levels released by the cells were determined with ELISA.

RESULTS

Resveratrol treatment significantly brought down serum levels of inflammatory cytokines (i.e. TNF-α, IL-1β and IL-6), kidney function indicators (i.e. Scr, blood urea nitrogen [BUN] and Scys C), AKI biomarkers (i.e. NGAL and KIM-1) and MALAT1 in cecal ligation and puncture (CLP)-induced septic model rats (all p < 0.05), and the life span of septic rats was elongated by resveratrol treatment (p < 0.05). Viability and cytokine release of LPS-treated HK2 cells were rescued by resveratrol (p < 0.05), which was accompanied by a marked fall of MALAT1 expression (p < 0.05). In addition, si-MALAT1 diminished viability and suppressed cytokine release of HK2 cells, while pcDNA3.1-MALAT1 hindered the impact of resveratrol on the inflammatory response of HK2 cells (p < 0.05). Ultimately, miR-205, a protective molecule in sepsis-relevant AKI, was down-regulated by resveratrol and si-MALAT1 (p < 0.05).

CONCLUSIONS

Resveratrol relieved sepsis-induced AKI by restraining the lncRNA MALAT1/miR-205 axis.

Diagnostic value and significance of serum miR-132 combined with miR-223 for sepsis-induced cardiomyopathy

In previous studies, miR-132 and miR-223 were considered to be involved in cellular and pathological processes of diseases. However, the role of early diagnosis and prognosis evaluation in sepsis-induced cardiomyopathy (SIC) remains unknown. The present study aimed to explore the diagnostic value of combined detection of miR-132 and miR-223 for SIC and their correlation with creatine kinase-MB (CK-MB), cardiac troponin I (cTnI), tumor necrosis factor α (TNF-α), and interleukin-6 (IL)-6. SIC patients (n=80) admitted to Tianjin Medical University General Hospital were assigned to the research group (RG), while 60 healthy participants receiving physical examinations at the same period were assigned to the control group (CG). Serum expression profiles of miR-132 and miR-223 were detected by the RT-qPCR. CK-MB and cTnI were assessed using chemiluminescence assay, and TNF-α and IL-6 by enzyme-linked immunosorbent assay (ELISA). Serum miR-132 and miR-223 levels were significantly lower in the RG than in the CG (P<0.001). The sensitivity and specificity for the diagnosis of SIC were 82.50 and 71.67% for miR-132, 95.00 and 61.67% for miR-223, as well as 86.25 and 86.67% for miR-132 combined with miR-223. Serum miR-132 and miR-223 levels were significantly higher in the survivor group than in the deceased group (P<0.001). The sensitivity and specificity for the prognosis of SIC were 85.96 and 65.22% for miR-132 combined with miR-223. Serum miR-132 and miR-223 were negatively correlated with serum CK-MB, cTnI, TNF-α, and IL-6 (P<0.001). miR-132 combined with miR-223 can be used for early diagnosis and prognostic evaluation of SIC, and the two are correlated with CK-MB, cTnI, TNF-α, and IL-6.

MALAT1 Maintains the Intestinal Mucosal Homeostasis in Crohn's Disease via the miR-146b-5p-CLDN11/NUMB Pathway

BACKGROUND AND AIMS

Intestinal homeostasis disorder is critical for developing Crohn's disease [CD]. Maintaining mucosal barrier integrity is essential for intestinal homeostasis, preventing intestinal injury and complications. Among the remarkably altered long non-coding RNAs [lncRNAs] in CD, we aimed to investigate whether metastasis-associated lung adenocarcinoma transcript 1 [MALAT1] modulated CD and consequent disruption of intestinal homeostasis.

METHODS

Microarray analyses on intestinal mucosa of CD patients and controls were performed to identify dysregulated lncRNAs. MALAT1 expression was investigated via qRT-PCR and its distribution in intestinal tissues was detected using BaseScope. Intestines from MALAT1 knockout mice with colitis were investigated using histological, molecular, and biochemical approaches. Effects of intestinal epithelial cells, transfected with MALAT1 lentiviruses and Smart Silencer, on monolayer permeability and apical junction complex [AJC] proteins were analysed. MiR-146b-5p was confirmed as a critical MALAT1 mediator in cells transfected with miR-146b-5p mimic/inhibitor and in colitis mice administered agomir-146b-5p/antagomir-146b-5p. Interaction between MALAT1 and miR-146b-5p was predicted via bioinformatics and validated using Dual-luciferase reporter assay and Ago2-RIP.

RESULTS

MALAT1 was aberrantly downregulated in the intestine mucosa of CD patients and mice with experimental colitis. MALAT1 knockout mice were hypersensitive to DSS-induced experimental colitis. MALAT1 regulated the intestinal mucosal barrier and regained intestinal homeostasis by sequestering miR-146b-5p and maintaining the expression of the AJC proteins NUMB and CLDN11.

CONCLUSIONS

Downregulation of MALAT1 contributed to the pathogenesis of CD by disrupting AJC. Thus, a specific MALAT1-miR-146b-5p-NUMB/CLDN11 pathway that plays a vital role in maintaining intestinal mucosal homeostasis may serve as a novel target for CD treatment.

Dexmedetomidine Suppressed the Biological Behavior of HK-2 Cells Treated with LPS by Down-Regulating ALKBH5

Dexmedetomidine inhibits the release of inflammatory cytokines and exerts a systemic anti-inflammatory effect and has potential protective effects on vital organs such as lung, heart, and kidneys. The aim of this study was to investigate the effect of dexmedetomidine on LPS-treated HK-2 cells in vitro and explore the potential mechanisms. The HK-2 cells were pretreated with dexmedetomidine before LPS induction. CCK-8, flow cytometry, ELISA, or qRT-PCR was performed to detect cell proliferation, apoptosis, and proinflammatory cytokine expression. The levels of MALAT1 in HK-2 cells under different stimulation were measured by qRT-PCR. Then, m6A RNA immunoprecipitation was performed to detect methylated MALAT1 in HK-2 cells. The results showed dexmedetomidine suppressed cell viability, induced cell apoptosis, and reduced inflammation cytokine production of LPS-treated HK-2 cells. Besides, dexmedetomidine reduced the expression of MALAT1 in HK-2 cells under LPS stimulation. In addition, ALKBH5 could up-regulate MALAT1 expression by demethylation. Furthermore, dexmedetomidine inhibited the expression of ALKBH5 in LPS-treated HK-2 cells. ALKBH5 knockdown inhibited cell viability, induced cell apoptosis, and decreased inflammation cytokine production of LPS-treated HK-2 cells. In short, dexmedetomidine suppressed the biological behavior of HK-2 cells treated with LPS by inhibiting the expression of ALKBH5 in vitro, which may provide potential targets for the prevention and treatment of sepsis-induced kidney injury.

Silencing CDK6-AS1 inhibits LPS-induced inflammatory damage in HK-2 cells

In this study, we aim to discover the importance of long non-coding RNA cyclin-dependent kinase 6 (CDK6)-AS1 in lipopolysaccharide (LPS)-induced HK-2 cells. We treated the HK-2 cells with LPS and knocked down CDK6-AS1 in HK-2 cells and then analyzed the effects of CDK6-AS1 on the viability of cell, cell apoptosis, the expression of cytokines via MTT, flow cytometry, enzyme-linked immunosorbent assay (ELISA), and qPCR. The results showed that silencing CDK6-AS1 alleviated LPS-induced inhibition of HK-2 cell proliferation, release of IL-1β, IL-8, IL-6, and TNF-α, cell apoptosis, and decrease in mitochondrial membrane potential. In addition, decreasing the level of CDK6-AS1 inhibited the reduction of Bcl-2 levels, the expression of Bax, cleaved caspade-9, and cleaved caspase-3, induced by LPS. In conclusion, lowering CDK6-AS1 level alleviates LPS-induced inflammatory damage in HK-2 cells.

Clinical Significance of the Serum lncRNA NORAD Expression in Patients with Neonatal Sepsis and Its Association with miR-410-3p

Purpose

Neonatal sepsis (NS) is one of the most crucial causes of death in newborns. This investigation aimed to validate the expression level of NORAD and the probable mechanism underlying the function of NORAD in NS.

Patients and Methods

The expression of NORAD and miR-410-3p was identified by qRT-PCR. The diagnostic sensitivity and specificity of NORAD were examined by the ROC curve. The NS cell models were established by the treatment of lipopolysaccharide (LPS) in the macrophage RAW264.7 cells. The luciferase report assay was performed to detect the target relationship between NORAD and miR-410-3p and the association between them was revealed by Pearson correlation.

Results

The expression of NORAD was at a higher level in the NS group than in the pneumonia controls. The levels of NORAD could sever as a diagnostic marker on discriminating NS patients from pneumonia neonates. The expression of IL-6, IL-8, and TNF-α was enhanced in the macrophage cells under LPS circumstances, while NORAD knockdown reversed the overexpression of these pro-inflammatory cytokines. Besides, miR-410-3p was a possible ceRNA of NORAD by the finding that the luciferase activity fell in the co-transfection of miR-410-3p mimics and WT-NORAD group. In vitro, LPS management could inhibit the expression of miR-410-3p, while silenced NORAD ameliorated the suppressed miR-410-3p levels. Decreased expression of miR-410-3p was discovered in NS patients and the changes of miR-410-3p expression were correlated with the levels of NORAD in the NS patients.

Conclusion

We found a raised level of NORAD in the NS patients and it might be a diagnostic indicator for NS patients. NORAD elimination meliorated the inflammation actions steered by LPS. MiR-410-3p was a target of NORAD and lowly expressed in the NS patients.

A Novel Regulatory Player in the Innate Immune System: Long Non-Coding RNAs

Long non-coding RNAs (lncRNAs) represent crucial transcriptional and post-transcriptional gene regulators during antimicrobial responses in the host innate immune system. Studies have shown that lncRNAs are expressed in a highly tissue- and cell-specific- manner and are involved in the differentiation and function of innate immune cells, as well as inflammatory and antiviral processes, through versatile molecular mechanisms. These lncRNAs function via the interactions with DNA, RNA, or protein in either cis or trans pattern, relying on their specific sequences or their transcriptions and processing. The dysregulation of lncRNA function is associated with various human non-infectious diseases, such as inflammatory bowel disease, cardiovascular diseases, and diabetes mellitus. Here, we provide an overview of the regulation and mechanisms of lncRNA function in the development and differentiation of innate immune cells, and during the activation or repression of innate immune responses. These elucidations might be beneficial for the development of therapeutic strategies targeting inflammatory and innate immune-mediated diseases.

The lncRNA XIST/miR-150-5p/c-Fos axis regulates sepsis-induced myocardial injury via TXNIP-modulated pyroptosis

Myocardial injury is a severe complication of sepsis and contributes substantially to the death of critically ill patients. Long non-coding RNAs (lncRNAs) participate in the pathogenesis of sepsis-induced myocardial injury. In this study, we investigated the role of lncRNA X-inactive specific transcript (XIST) in septic myocardial injury and explored its mechanism. Lipopolysaccharide (LPS)-stimulated H9C2 cells and rats subjected to cecal ligation and puncture (CLP) were used as the in vitro and in vivo models. After exposure to LPS, XIST and c-Fos levels were upregulated, but miR-150-5p was downregulated in H9C2 cardiomyocytes and myocardial tissues. XIST affected viability, apoptosis, and pyroptosis in LPS-challenged H9C2 cells. Moreover, XIST knockdown attenuated LPS-induced injury in H9C2 cells by targeting the miR-150-5p/c-Fos axis. c-Fos could bound to the promoter of the TXNIP/XIST gene and enhanced TXNIP/XIST expression. Silencing of XIST improved cardiac function and survival rate and reduced apoptosis and pyroptosis by regulating the miR-150-5p/c-Fos axis in septic rats in vivo. Taken together, our data show that XIST/miR-150-5p/c-Fos axis affected septic myocardial injury, which may indicate a novel therapeutic strategy for sepsis-induced myocardial injury.

Non-coding RNAs: update on mechanisms and therapeutic targets from the ESC Working Groups of Myocardial Function and Cellular Biology of the Heart

Vast parts of mammalian genomes are actively transcribed, predominantly giving rise to non-coding RNA (ncRNA) transcripts including microRNAs, long ncRNAs, and circular RNAs among others. Contrary to previous opinions that most of these RNAs are non-functional molecules, they are now recognized as critical regulators of many physiological and pathological processes including those of the cardiovascular system. The discovery of functional ncRNAs has opened up new research avenues aiming at understanding ncRNA-related disease mechanisms as well as exploiting them as novel therapeutics in cardiovascular therapy. In this review, we give an update on the current progress in ncRNA research, particularly focusing on cardiovascular physiological and disease processes, which are under current investigation at the ESC Working Groups of Myocardial Function and Cellular Biology of the Heart. This includes a range of topics such as extracellular vesicle-mediated communication, neurohormonal regulation, inflammation, cardiac remodelling, cardio-oncology as well as cardiac development and regeneration, collectively highlighting the wide-spread involvement and importance of ncRNAs in the cardiovascular system.

LncRNA-ENST00000421645 promotes T cells to secrete IFN-γ by sponging PCM1 in neurosyphilis

Aim: Neurosyphilis patients exhibited significant expression of long noncoding RNA (lncRNA) in peripheral blood T lymphocytes. In this study, we further clarified the role of lncRNA-ENST00000421645 in the pathogenic mechanism of neurosyphilis. Methods: lncRNA-ENST00000421645 was transfected into Jurkat-E6-1 cells, namely lentivirus (Lv)-1645 cells. RNA pull-down assay, flow cytometry, RT-qPCR, ELISA (Neobioscience Technology Co Ltd, Shenzhen, China) and RNA immunoprecipitation chip assay were used to analyze the function of lncRNA-ENST00000421645. Results: The expression of IFN-γ in Lv-1645 cells was significantly increased compared to that in Jurkat-E6-1 cells stimulated by phorbol-12-myristate-13-acetate (PMA). Then, it was suggested that lncRNA-ENST00000421645 interacts with PCM1 protein. Silencing PCM1 significantly increased the level of IFN-γ in Lv-1645 cells stimulated by PMA. Conclusion: This study revealed that lncRNA-ENST00000421645 mediates the production of IFN-γ by sponging PCM1 protein after PMA stimulation.

Long noncoding RNAs: A potential target in sepsis-induced cellular disorder

Sepsis, an inflammation-related clinical syndrome, is characterized by disrupted immune homeostasis accompanied by infection and multiple organ dysfunction as determined by the Sequential Organ Failure Assessment (SOFA). Substantial evidence has recently suggested that lncRNAs orchestrate various biological processes in diseases, and lncRNAs play special roles in the diagnosis and management of sepsis. To date, very few reviews have provided clear and comprehensive clues to demonstrate the roles of lncRNAs in the pathogenesis of sepsis. Based on previously published studies, in this review, we summarize the different functions of lncRNAs in sepsis-induced cellular disorders and sepsis-induced organ failure to show the potential roles of lncRNAs in the diagnosis and management of sepsis. We further depict the function of some lncRNAs known to be pivotal regulators in the pathogenesis of sepsis to discuss the underlying molecular events. Additionally, we list and discuss several hotspots in research on lncRNAs, which may be conducive to future lncRNA-targeted therapeutic approaches for sepsis treatment.

Role of non-coding RNAs as biomarkers of deleterious cardiovascular effects in sepsis

The mechanisms occurring during sepsis that produce an increased risk of cardiovascular (CV) disease (CVD) are poorly understood. Even less information exists regarding CV dysfunction as a complication of sepsis, particularly for sepsis-induced cardiomyopathy. However, recent research has demonstrated that non-coding RNAs, including microRNAs, long non-coding RNAs, and circular RNAs, play a crucial role in genetic reprogramming, gene regulation, and inflammation during the development of CVD. Here we describe experimental findings showing the importance of non-coding RNAs mediating relevant mechanisms underlying CV dysfunction after sepsis, so contributing to sepsis-induced cardiomyopathy. Importantly, non-coding RNAs are critical novel regulators of CVD risk factors. Thus, they are potential candidates to improve diagnostics and prognosis of sepsis-induced cardiomyopathy and other CVD events occurring after sepsis and set the basis to design novel therapeutic strategies.

LncRNA CASC2 Alleviates Sepsis-induced Acute Lung Injury by Regulating the miR-152-3p/PDK4 Axis

Background: Acute lung injury (ALI) is an early complication of sepsis and it is also considered as an important cause of high mortality in sepsis patients. This research aimed to explore the potential role and mechanism of long non-coding RNA (lncRNA) cancer susceptibility candidate 2 (CASC2) in sepsis-induced ALI. Methods: The levels of CASC2, microRNA-152-3p (miR-152-3p) and pyruvate dehydrogenase kinase 4 (PDK4) in sepsis patients and LPS-treated HPAEpiC were detected by quantitative real-time PCR and western blot. Cell viability and apoptosis were assessed by Counting Kit-8 (CCK-8) assay and flow cytometry. The concentrations of inflammatory factors were tested by Enzyme-linked immunosorbent assay. Oxidative stress was evaluated by the levels of reactive oxygen species and superoxide dismutase using corresponding commercial kits. The targeting relationship between miR-152-3p and CASC2 or PDK4 was verified by dual-luciferase reporter, RNA immunoprecipitation (RIP) and RNA pull-down assays.Results: CASC2 and PDK4 were down-regulated, while miR-152-3p was up-regulated in sepsis patients and LPS-stimulated HPAEpiC. Overexpression of CASC2 relieved the LPS-resulted cell viability inhibition, apoptosis promotion, inflammatory and oxidative damages in HPAEpiC. In addition, miR-152-3p was a miRNA target of CASC2 and CASC2 alleviated cell injury in LPS-disposed HPAEpiC by sponging miR-152-3p. Moreover, miR-152-3p directly targeted PDK4 and CASC2 increased the PDK4 expression by depending on the sponge effect on miR-152-3p. Meanwhile, inhibition of miR-152-3p attenuated LPS-triggered HPAEpiC injury by upregulating the level of PDK4.Conclusion: These results suggested that CASC2 ameliorated the LPS-induced injury in HPAEpiC via regulating miR-152-3p/PDK4 pathway.

Circular RNA circACSL1 aggravated myocardial inflammation and myocardial injury by sponging miR-8055 and regulating MAPK14 expression

Myocarditis (MC) is a common, potentially life-threatening inflammatory disease of the myocardium. A growing body of evidence has shown that mitogen-activated protein kinase 14 (MAPK14) participates in the pathogenesis of MC. However, the upstream regulators of MAPK14 remain enigmatic. Circular RNAs (circRNAs) have been identified to play vital roles in the pathophysiology of cardiovascular diseases. Nevertheless, the clinical significance, biological function, and regulatory mechanisms of circRNAs in MC remain poorly understood. In this study, we determined a novel circRNA, circACSL1 (ID: hsa_circ_0071542), which was significantly upregulated in the acute phase of MC, and its dynamic change in expression was related to the progression of MC. We used lipopolysaccharide (LPS) to induce the inflammatory responses in the human cardiomyocytes (HCM) line for in vitro and in cellulo experiments. The pro-inflammatory factors (IL-1β, IL-6, and TNF-α), myocardial injury markers (cTnT, CKMB, and BNP), cell viability, and cell apoptosis were measured to evaluate the extent of myocardial inflammation and myocardial injury level. Functional experiments, including gain-of-function and loss-of-function, were then performed to investigate the pro-inflammatory roles of circACSL1. The results revealed that circACSL1 could aggravate inflammation, myocardial injury, and apoptosis in HCM. Mechanistically, circACSL1 acted as a sponge for miR-8055-binding sites to regulate the downstream target MAPK14 expression. Furthermore, overexpression of miR-8055 rescued the pro-inflammatory effects of circACSL1 on HCM, and the upregulation of MAPK14 induced by circACSL1 was attenuated by miR-8055 overexpression. Knockdown of circACSL1 or overexpression of miR-8055 reduced myocardial inflammation and myocardial injury level and these effects were rescued by overexpression of MAPK14. In summary, our study demonstrated that circACSL1 could aggravate myocardial inflammation and myocardial injury through competitive absorption of miR-8055, thereby upregulating MAPK14 expression. Moreover, circACSL1 may represent a potential novel biomarker for the precise diagnosis of MC and offer a promising therapeutic target for MC treatment.

Long Noncoding RNA: Regulatory Mechanisms and Therapeutic Potential in Sepsis

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection and is characterized by a hyperinflammatory state accompanied by immunosuppression. Long noncoding RNAs (lncRNAs) are noncoding RNAs longer than 200 nucleotides and have important roles in mediating various biological processes. Recently, lncRNAs were found to exert both promotive and inhibitory immune functions in sepsis, thus participating in sepsis regulation. Additionally, several studies have revealed that lncRNAs are involved in sepsis-induced organ dysfunctions, including cardiovascular dysfunction, acute lung injury, and acute kidney injury. Considering the lack of effective biomarkers for early identification and specific treatment for sepsis, lncRNAs may be promising biomarkers and even targets for sepsis therapies. This review systematically highlights the recent advances regarding the roles of lncRNAs in sepsis and sheds light on their use as potential biomarkers and treatment targets for sepsis.

The Role of Long Non-coding RNAs in Sepsis-Induced Cardiac Dysfunction

Sepsis is a syndrome with life-threatening organ dysfunction induced by a dysregulated host response to infection. The heart is one of the most commonly involved organs during sepsis, and cardiac dysfunction, which is usually indicative of an extremely poor clinical outcome, is a leading cause of death in septic cases. Despite substantial improvements in the understanding of the mechanisms that contribute to the origin and responses to sepsis, the prognosis of sepsis-induced cardiac dysfunction (SICD) remains poor and its molecular pathophysiological changes are not well-characterized. The recently discovered group of mediators known as long non-coding RNAs (lncRNAs) have presented novel insights and opportunities to explore the mechanisms and development of SICD and may provide new targets for diagnosis and therapeutic strategies. LncRNAs are RNA transcripts of more than 200 nucleotides with limited or no protein-coding potential. Evidence has rapidly accumulated from numerous studies on how lncRNAs function in associated regulatory circuits during SICD. This review outlines the direct evidence of the effect of lncRNAs on SICD based on clinical trials and animal studies. Furthermore, potential functional lncRNAs in SICD that have been identified in sepsis studies are summarized with a proven biological function in research on other cardiovascular diseases.

MIR210HG Aggravates Sepsis-Induced Inflammatory Response of Proximal Tubular Epithelial Cell via the NF-κB Signaling Pathway

PURPOSE

Acute kidney injury (AKI) is a serious complication of sepsis and is characterized by inflammatory response. MicroRNA-210 host gene (MIR210HG) is upregulated in human proximal tubular epithelial cells under treatment of inflammatory cytokines. This study aimed to explore the role of MIR210HG in sepsis-induced AKI.

MATERIALS AND METHODS

Cell viability was detected by a cell counting kit 8 assay. The levels of proinflammatory cytokines were detected by enzyme-linked immunosorbent assay kits. The protein levels of p65, IκBα, and p-IκBα were examined by western blot analysis. The nuclear translocation of nuclear factor kappa B (NF-κB) was detected by immunofluorescence assay. The histological changes of kidneys were analyzed by hematoxylin and eosin staining assay.

RESULTS

Lipopolysaccharide (LPS) treatment significantly inhibited cell viability and increased productions of proinflammatory cytokines in proximal tubular epithelial cells (HKC-8). Additionally, MIR210HG levels in HKC-8 cells were increased by LPS treatment. MIR210HG silencing inhibited the LPS-induced cell inflammatory response. MIR210HG activated the NF-κB signaling pathway by promoting the phosphorylation of IκBα and nuclear translocation of p65. Rescue assays revealed that the MIR210HG-induced increase of cytokines levels and decline of cell viability were rescued by QNZ treatment. Knockdown of MIR210HG decreased blood urea nitrogen, serum creatinine, and proinflammatory cytokine levels in AKI rats. Moreover, the knockdown of MIR210HG protected against AKI-induced histological changes of kidneys in rats.

CONCLUSION

MIR210HG promotes sepsis-induced inflammatory response of HKC-8 cells by activating the NF-κB signaling pathway. This novel discovery may be helpful for the improvement of sepsis-induced AKI.

Long non-coding RNA pairs to assist in diagnosing sepsis

Background

Sepsis is the major cause of death in Intensive Care Unit (ICU) globally. Molecular detection enables rapid diagnosis that allows early intervention to minimize the death rate. Recent studies showed that long non-coding RNAs (lncRNAs) regulate proinflammatory genes and are related to the dysfunction of organs in sepsis. Identifying lncRNA signature with absolute abundance is challenging because of the technical variation and the systematic experimental bias.

Results

Cohorts (n = 768) containing whole blood lncRNA profiling of sepsis patients in the Gene Expression Omnibus (GEO) database were included. We proposed a novel diagnostic strategy that made use of the relative expressions of lncRNA pairs, which are reversed between sepsis patients and normal controls (eg. lncRNA_i > lncRNA_j in sepsis patients and lncRNA_i < lncRNA_j in normal controls), to identify 14 lncRNA pairs as a sepsis diagnostic signature. The signature was then applied to independent cohorts (n = 644) to evaluate its predictive performance across different ages and normalization methods. Comparing to common machine learning models and existing signatures, SepSigLnc consistently attains better performance on the validation cohorts from the same age group (AUC = 0.990 & 0.995 in two cohorts) and across different groups (AUC = 0.878 on average), as well as cohorts processed by an alternative normalization method (AUC = 0.953 on average). Functional analysis demonstrates that the lncRNA pairs in SepsigLnc are functionally similar and tend to implicate in the same biological processes including cell fate commitment and cellular response to steroid hormone stimulus.

Conclusion

Our study identified 14 lncRNA pairs as signature that can facilitate the diagnosis of septic patients at an intervenable point when clinical manifestations are not dramatic. Also, the computational procedure can be generalized to a standard procedure for discovering diagnostic molecule signatures.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-021-07576-4.