ADAR1 Alleviates Inflammation in a Murine Sepsis Model via the ADAR1-miR-30a-SOCS3 Axis

RNA editing in host lncRNAs as potential modulator in SARS-CoV-2 variants-host immune response dynamics

Both host and viral RNA editing plays a crucial role in host's response to infection, yet our understanding of host RNA editing remains limited. In this study of in-house generated RNA sequencing (RNA-seq) data of 211 hospitalized COVID-19 patients with PreVOC, Delta, and Omicron variants, we observed a significant differential editing frequency and patterns in long non-coding RNAs (lncRNAs), with Delta group displaying lower RNA editing compared to PreVOC/Omicron patients. Notably, multiple transcripts of UGDH-AS1 and NEAT1 exhibited high editing frequencies. Expression of ADAR1/APOBEC3A/APOBEC3G and differential abundance of repeats were possible modulators of differential editing across patient groups. We observed a shift in crucial infection-related pathways wherein the pathways were downregulated in Delta compared to PreVOC and Omicron. Our genomics-based evidence suggests that lncRNA editing influences stability, miRNA binding, and expression of both lncRNA and target genes. Overall, the study highlights the role of lncRNAs and how editing within host lncRNAs modulates the disease severity.

Integrated Network Pharmacology and Molecular Docking to Elucidate the Efficacy and Potential Mechanisms of Tea Ingredients in Sepsis Treatment

Sepsis, a critical health condition induced by an overactive innate immune response and reactive oxygen species (ROS)-driven host damage through apoptosis and ferroptosis, continues to pose a significant mortality risk. Despite accumulating evidence of the potential therapeutic properties of tea ingredients, their specific anti-sepsis potential remains inadequately explored. This study comprehensively investigates the targeted genes of tea ingredients, notably epigallocatechin 3-gallate (EGCG), and their correlation with sepsis signature genes. Our findings elucidate that tea ingredients, especially EGCG, exhibit substantial potential in mitigating inflammation and sepsis-induced damage. Through the inhibition of the MAPK cascade and macrophage activation and by impeding the transcriptional activity of RELA (transcription factor p65) in sepsis, EGCG demonstrates significant anti-sepsis efficacy. Molecular docking analysis further underpins this by revealing the close proximity of EGCG and (-)-catechin gallate binding sites to that of RELA on DNA. Subsequent in vitro assays illuminated EGCG's instrumental role in modulating macrophage M2 polarization, balancing M1 and M2 differentiation of bone marrow-derived macrophages (BMDMs), curtailing inflammatory factor secretion, and inhibiting ROS production. Moreover, EGCG effectively suppresses the expression of ferroptosis/apoptosis markers in LPS-induced macrophages during their early stages. Our study advances our understanding of sepsis prevention and treatment strategies, suggesting that tea ingredients such as EGCG could play a pivotal role in developing future sepsis therapies due to their protective effects.

MicroRNA-30a inhibits cell proliferation in a sepsis-induced acute kidney injury model by targeting the YAP-TEAD complex

Background

Acute kidney injury (AKI) is a primary feature of renal complications in patients with sepsis. MicroRNA (miRNA/miR)-30a is an essential regulator of cardiovascular diseases, tumors, phagocytosis, and other physical processes, but whether it participates in sepsis-induced AKI (sepsis-AKI) is unknown. We aimed to elucidate the functions and molecular mechanism underlying miR-30a activity in sepsis-AKI.

Methods

The classical cecal ligation and puncture (CLP) method and lipopolysaccharide (LPS)-induced Human Kidney 2 (HK-2) cells were used to establish in vivo and in vitro sepsis-AKI models. Specific pathogen-free and mature male Sprague-Dawley (SD) rats, aged 6-8 weeks (weight 200-250 g), were randomly divided into five-time phase subgroups. Fluid resuscitation with 30 mL/kg 37 °C saline was administered after the operation, without antibiotics. Formalin-fixed, paraffin-embedded kidney sections were stained with hematoxylin and eosin. SD rat kidney tissue samples were collected for analysis by real-time quantitative polymerase chain reaction and enzyme-linked immunosorbent assay. HK-2 cells were transfected with hsa-miR-30a-3p mimics or inhibitors, and compared with untreated normal controls. RNA, protein, and cell viability were evaluated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR), western blot, and cell counting kit-8 methods. A Dual-Luciferase Assay Kit (Promega) was used to measure luciferase activity 48 h after transfection with miR-30a-3p mimics.

Results

Expression levels of miR-30a-3p and miR-30a-5p in renal tissues of the sepsis group were significantly reduced at 12 h and 24 h (P <0.05). Tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were significantly increased in renal tissue 3 h after the operation in rats (P <0.05), and gradually decreased 6 h, 12 h, and 24 h after CLP. Levels of miR-30a-5p and miR-30a-3p were significantly down-regulated at 3 h after LPS treatment (P <0.05), and gradually decreased in HK-2 cells. One hour after LPS (10 µg/mL) treatment, TNF-α and IL-1β levels in HK-2 cells were significantly up-regulated (P < 0.05), and they were markedly down-regulated after 3 h (P <0.05). IL-6 expression levels began to rise after LPS treatment of cells, peaked at 6 h (P <0.05), and then decreased to the initial level within a few hours. Stimulation with 10 µg/mL LPS promoted HK-2 cells proliferation, which was inhibited after miR-30a-3p-mimic transfection. Bioinformatics prediction identified 37 potential miR-30a-3p target genes, including transcriptional enhanced associate domain 1 (TEAD1). After transfection of HK-2 cells with miR-30a-3p mimics and miR-30a-3p inhibitor, TEAD1 transcript was significantly up- and down-regulated, respectively (both P <0.05). After LPS treatment (24 h), expression of TEAD1 in the inhibitors group was significantly increased (P <0.01), while that in the mimics group was significantly suppressed (P <0.01). In the dual luciferase reporter experiment, miR-30a-3p overexpression decreased fluorescence intensity (P <0.01) from TEAD1-wt-containing plasmids, but did not influence fluorescence intensity from TEAD1-muta-containing plasmids. LPS may promote HK-2 cells proliferation through the miR-30a-3p/TEAD1 pathway.

Conclusion

In a background of expression of inflammatory factors, including TNF-α, IL-1β, and IL-6, which were transiently increased in the sepsis-AKI model, miR-30a was down-regulated. Down-regulated miR-30a-3p may promote cell proliferation by targeting TEAD1 in LPS-induced HK-2 cells, demonstrating its potential as a biomarker for early sepsis-AKI diagnosis.

ADAR1 protects pulmonary macrophages from sepsis-induced pyroptosis and lung injury through miR-21/A20 signaling

Acute lung injury is a serious complication of sepsis with high morbidity and mortality. Pyroptosis is a proinflammatory form of programmed cell death that leads to immune dysregulation and organ dysfunction during sepsis. We previously found that adenosine deaminase acting on double-stranded RNA 1 (ADAR1) plays regulatory roles in the pathology of sepsis, but the mechanism of ADAR1 in sepsis-induced pyroptosis and lung injury remains unclear. Here, we mainly investigated the regulatory effects and underlying mechanism of ADAR1 in sepsis-induced lung injury and pyroptosis of pulmonary macrophages through RNA sequencing of clinical samples, caecal ligation and puncture (CLP)-induced septic mouse models, and in vitro cellular experiments using RAW264.7 cells with lipopolysaccharide (LPS) stimulation. The results showed that pyroptosis was activated in peripheral blood mononuclear cells (PBMCs) from patients with sepsis. In the CLP-induced septic mouse model, pyroptosis was mainly activated in pulmonary macrophages. LPS-stimulated RAW264.7 cells showed significantly increased activation of the NLRP3 inflammasome. ADAR1 was downregulated in PMBCs of patients with sepsis, and overexpression of ADAR1 alleviated CLP-induced lung injury and NLRP3 inflammasome activation. Mechanistically, the regulatory effects of ADAR1 on macrophage pyroptosis were mediated by the miR-21/A20/NLRP3 signalling cascade. ADAR1 attenuated sepsis-induced lung injury and hindered the activation of pyroptosis in pulmonary macrophages in sepsis through the miR-21/A20/NLRP3 axis. Our study highlights the role of ADAR1 in protecting pulmonary macrophages against pyroptosis and suggests targeting ADAR1/miR-21 signalling as a therapeutic opportunity in sepsis-related lung injury.

ADAR1 exacerbates ischemic brain injury via astrocyte-mediated neuron apoptosis

Astrocytes affect stroke outcomes by acquiring functionally dominant phenotypes. Understanding molecular mechanisms dictating astrocyte functional status after brain ischemia/reperfusion may reveal new therapeutic strategies. Adenosine deaminase acting on RNA (ADAR1), an RNA editing enzyme, is not normally expressed in astrocytes, but highly induced in astrocytes in ischemic stroke lesions. The expression of ADAR1 steeply increased from day 1 to day 7 after middle cerebral artery occlusion (MCAO) for 1 h followed by reperfusion. ADAR1 deficiency markedly ameliorated the volume of the cerebral infarction and neurological deficits as shown by the rotarod and cylinder tests, which was due to the reduction of the numbers of activated astrocytes and microglia. Surprisingly, ADAR1 was mainly expressed in astrocytes while only marginally in microglia. In primary cultured astrocytes, ADAR1 promoted astrocyte proliferation via phosphatidylinositol 3-kinase (PI3K)/Akt pathway. Furthermore, ADAR1 deficiency inhibited brain cell apoptosis in mice with MCAO as well as in activated astrocyte-conditioned medium-induced neurons in vitro. It appeared that ADAR1 induces neuron apoptosis by secretion of IL-1β, IL-6 and TNF-α from astrocytes through the production of reactive oxygen species. These results indicated that ADAR1 is a novel regulator promoting the proliferation of the activated astrocytes following ischemic stroke, which produce various inflammatory cytokines, leading to neuron apoptosis and worsened ischemic stroke outcome.

Electroacupuncture-driven endogenous circulating serum exosomes as a potential therapeutic strategy for sepsis

BACKGROUND

Sepsis poses a serious threat to human life and health, with limited options for current clinical treatments. Acupuncture plays an active role in treating sepsis. However, previous studies have focused on the neuromodulatory effect of acupuncture, neglecting its network modulatory effect. Exosomes, as a new way of intercellular communication, may play an important role in transmitting acupuncture information. This paper explores the possibility of electroacupuncture-driven endogenous circulating serum exosomes and their carried miRNAs as a potential treatment for sepsis.

METHODS

The sepsis mouse model was established by intraperitoneal injection of lipopolysaccharide (LPS) (12 mg/kg, 24 mg/kg), and EA (continuous wave, 10 Hz, intensity 5) or intraperitoneal injection of Acupuncture Exosomes (Acu-exo) were performed before the model establishment. The therapeutic effect was evaluated by survival rate, ELISA, H&E staining and lung wet/dry weight ration (W/D). In vivo imaging of small animals was used to observe the accumulation of Acu-exo in various organs of sepsis mice. LPS was used to induce macrophages in cell experiments, and the effect of Acu-exo on macrophage inflammatory cytokines was observed. In addition, The miRNA sequencing method was further used to detect the serum exosomes of normal and EA-treated mice, and combined with network biology analysis methods to screen possible key targets.

RESULTS

EA and Acu-exo reduced the W/D and lung tissue damage in sepsis mice, down-regulated the expression of serum inflammatory cytokines TNF-α and IL-6, and increased the survival rate of sepsis mice. In vivo imaging of small animals found that Acu-exo were accumulated in the lungs of sepsis mice. Cell experiments proved that Acu-exo down-regulated the expression of inflammatory cytokines TNF-α, IL-6 and IL-1β to alleviate the inflammatory response induced by LPS in macrophages. MiRNA sequencing revealed 53 differentially expressed miRNAs, and network biology analysis revealed the key targets of Acu-exo in sepsis treatment.

CONCLUSION

Electroacupuncture-driven endogenous circulating serum exosomes and their carried miRNAs may be a potential treatment for sepsis.

circVMA21 combining with TAF15 stabilizes SOCS3 mRNA to relieve septic lung injury through regulating NF-κB activation

BACKGROUND

Lung injury is a severe complication of sepsis, which brings great threats and challenges to human health. CircVMA21 has exhibited powerful anti- inflammation capacity. However, its underlying molecule mechanism remains blurry.

METHODS

Lipopolysaccharide (LPS) was used to treat mice and WI-38 cells to establish models of lung injury caused by sepsis. Lung injury was evaluated using HE staining. Cell apoptosis was tested by TUNEL and flow cytometry. Levels of inflammatory cytokines were detected using ELISA assay. CircVMA21 and SOCS3 expression was measured using RT-qPCR. The ROS, MDA, SOD and GSH production were monitored by commercial kits. The protein expression was examined with western blot. The correlations among circVMA21, SOCS3 and TAF15 were confirmed using RIP and RNA-pull down.

RESULTS

The expression of circVMA21 and SOCS3 was downregulated in LPS-induced lung injury of mice and WI-38 cells. Overexpressing circVMA21 or SOCS3 assuaged LPS-induced cell injury through repressing the levels of inflammatory factors, oxidative stress and cell apoptosis. NF-κB signaling pathway was inactivated by circVMA21 or SOCS3 overexpression. circVMA21 enhanced the stabilization of SOCS3 mRNA via interplaying with TAF15. SOCS3 knockdown destroyed the beneficial impacts of circVMA21 overexpression on LPS-induced cell injury.

CONCLUSION

CircVMA21 suppressed LPS-induced the levels of inflammatory factors, oxidative stress and cell apoptosis and improved LPS-induced lung injury by mediating TAF15/SOCS3/NF-κB axis.

Identification of novel biomarkers in septic cardiomyopathy via integrated bioinformatics analysis and experimental validation

Purpose: Septic cardiomyopathy (SCM) is an important world public health problem with high morbidity and mortality. It is necessary to identify SCM biomarkers at the genetic level to identify new therapeutic targets and strategies.

Method: DEGs in SCM were identified by comprehensive bioinformatics analysis of microarray datasets (GSE53007 and GSE79962) downloaded from the GEO database. Subsequently, bioinformatics analysis was used to conduct an in-depth exploration of DEGs, including GO and KEGG pathway enrichment analysis, PPI network construction, and key gene identification. The top ten Hub genes were identified, and then the SCM model was constructed by treating HL-1 cells and AC16 cells with LPS, and these top ten Hub genes were examined using qPCR.

Result: STAT3, SOCS3, CCL2, IL1R2, JUNB, S100A9, OSMR, ZFP36, and HAMP were significantly elevated in the established SCM cells model.

Conclusion: After bioinformatics analysis and experimental verification, it was demonstrated that STAT3, SOCS3, CCL2, IL1R2, JUNB, S100A9, OSMR, ZFP36, and HAMP might play important roles in SCM.

Brain Epitranscriptomic Analysis Revealed Altered A-to-I RNA Editing in Septic Patients

Recent studies suggest that RNA editing is associated with impaired brain function and neurological and psychiatric disorders. However, the role of A-to-I RNA editing during sepsis-associated encephalopathy (SAE) remains unclear. In this study, we analyzed adenosine-to-inosine (A-to-I) RNA editing in postmortem brain tissues from septic patients and controls. A total of 3024 high-confidence A-to-I RNA editing sites were identified. In sepsis, there were fewer A-to-I RNA editing genes and editing sites than in controls. Among all A-to-I RNA editing sites, 42 genes showed significantly differential RNA editing, with 23 downregulated and 19 upregulated in sepsis compared to controls. Notably, more than 50% of these genes were highly expressed in the brain and potentially related to neurological diseases. Notably, cis-regulatory analysis showed that the level of RNA editing in six differentially edited genes was significantly correlated with the gene expression, including HAUS augmin-like complex subunit 2 (HAUS2), protein phosphatase 3 catalytic subunit beta (PPP3CB), hook microtubule tethering protein 3 (HOOK3), CUB and Sushi multiple domains 1 (CSMD1), methyltransferase-like 7A (METTL7A), and kinesin light chain 2 (KLC2). Furthermore, enrichment analysis showed that fewer gene functions and KEGG pathways were enriched by edited genes in sepsis compared to controls. These results revealed alteration of A-to-I RNA editing in the human brain associated with sepsis, thus providing an important basis for understanding its role in neuropathology in SAE.

Regulatory Role of Non-Coding RNAs on Immune Responses During Sepsis

Sepsis is resulted from a systemic inflammatory response to bacterial, viral, or fungal agents. The induced inflammatory response by these microorganisms can lead to multiple organ system failure with devastating consequences. Recent studies have shown altered expressions of several non-coding RNAs such as long non-coding RNAs (lncRNAs), microRNAs (miRNAs) and circular RNAs (circRNAs) during sepsis. These transcripts have also been found to participate in the pathogenesis of multiple organ system failure through different mechanisms. NEAT1, MALAT1, THRIL, XIST, MIAT and TUG1 are among lncRNAs that participate in the pathoetiology of sepsis-related complications. miR-21, miR-155, miR-15a-5p, miR-494-3p, miR-218, miR-122, miR-208a-5p, miR-328 and miR-218 are examples of miRNAs participating in these complications. Finally, tens of circRNAs such as circC3P1, hsa_circRNA_104484, hsa_circRNA_104670 and circVMA21 and circ-PRKCI have been found to affect pathogenesis of sepsis. In the current review, we describe the role of these three classes of noncoding RNAs in the pathoetiology of sepsis-related complications.

miR-30a-5p inhibits osteogenesis and promotes periodontitis by targeting Runx2

BACKGROUND

Periodontitis is the most extensive chronic inflammatory bone resorption disease. MiRNAs offer a potential way for potential therapy. Indeed, miR-30a-5p had an increasing expression in periodontitis gingivae, but whether it promotes osteogenesis and inhibits inflammation remains unknown.

METHODS

Periodontitis model was exhibited by wire ligation and verified by micro-CT and HE staining; qPCR was used to detect the expression of miR-30a-5p; miR-30a-5p inhibitors and mimics were transfected into MC3T3-E1 cell line by lipofectamine 3000; The dual luciferase reporter gene experiment and RIP experiment were used to detect the relationship between miR-30a-5p and Runx2; Rescue experiment was used to verify the relationship between miR-30a-5p and Runx2.

RESULTS

Periodontitis model was exhibited successfully and miR-30a-5p was overexpressed at the bone and gingival tissues of this model. miR-30a-5p inhibitors not only promoted the osteogenesis but also relieved inflammation. Runx2 is a target of miR-30a-5p by dual luciferase reporter gene experiment and RIP experiment. Rescue experiments revealed that miR-30a-5p inhibitors would promote osteogenesis and relieve inflammation by targeting Runx2 in inflammation of MC3T3-E1 cell line.

CONCLUSIONS

That all suggested that miR-30a-5p-mediated-Runx2 provided a novel understanding of mechanism of periodontitis.

Circular RNA PUM1 (CircPUM1) attenuates trophoblast cell dysfunction and inflammation in recurrent spontaneous abortion via the MicroRNA-30a-5p (miR-30a-5p)/JUNB axis

Recurrent spontaneous abortion (RSA) is a threat to human reproductive health worldwide. CircPUM1 has been reported to participate in the pathogenesis of various diseases. However, there has been no report on its association with RSA yet. In this study, gene expressions were examined by RT-qPCR. Protein levels of JUNB and cleaved caspases-3 were detected by Western blotting. ELISA was used to detect TNF-α, IL-6, and IL-8 levels. Cell viability, migration, invasion, and apoapsis were analyzed using CCK-8, transwell, and flow cytometry assays. The association between miR-30a-5p and circPUM1 or JUNB was identified by bioinformatics analysis, dual-luciferase reporter assay, and RIP assay. Herein, we found circPUM1 was significantly downregulated in RSA placental samples. CircPUM1 knockdown induced decreased proliferation, migration, and invasion, but increased apoptosis, pro-apoptotic protein (cleaved caspases-3) level, and proinflammatory factor (TNF-α, IL-6, and IL-8) secretion in trophoblast cells. Furthermore, we confirmed that circPUM1 was a sponge for miR-30a-5p, and JUNB was directly targeted by miR-30a-5p. It was demonstrated that miR-30a-5p inhibition could reverse trophoblast cell dysfunction and inflammation induced by circPUM1 knockdown. In addition, we found that JUNB expression was negatively modulated by miR-30a-5p and positively regulated by circPUM1. Moreover, circPUM1 inhibition exacerbated dysfunction and inflammation in trophoblast cells via targeting JUNB. To sum up, our study indicated that circPUM1 could impair RSA occurrence and development by facilitating trophoblast cellular processes and protecting against inflammation via the miR-30a-5p/JUNB axis, providing a new target for the improvement of RSA diagnosis and treatment.

lncRNA SNHG17 promotes pancreatic carcinoma progression via cross-talking with miR-942

OBJECTIVE

Long non-coding RNA (lncRNA) SNHG17 has been shown to modulate the biological behavior of multiple cancers (e.g., colorectal and lung cancers). However, its involvement in pancreatic cancer (PC) has not been explored; therefore, in the present study, we sought to examine this involvement.

METHODS

First, the mRNA expression levels of various genes were quantified in PC tissues and cell lines using quantitative reverse-transcription PCR (qRT-PCR). The interaction between SNHG17 and miR-942 was explored by bioinformatics prediction as well as a dual luciferase reporter assay. The proliferation and viability of pancreatic carcinoma cells were examined using cell counting kit-8 and MTT assays, respectively. Cellular migratory and invasive properties were evaluated using transwell migration and wound healing assays. Cell death was measured using flow cytometry. Protein expression was quantified by western blotting.

RESULTS

SNHG17 expression was markedly higher in human PC specimens and cell lines than in normal healthy tissues and pancreatic epithelial cells. MiR-942 expression displayed the opposite trend. Bioinformatics prediction and a dual luciferase reporter assay confirmed that SNHG17 serves as a sponge for miR-942. Loss-of-function assay revealed that SNHG17 silencing reduced the proliferation and viability of PC cells, impaired their migratory and invasive capacities, and led to their apoptosis. All these changes could be reversed by miR-942 inhibition. Further mechanical studies showed that SNHG17 silencing decreased the expression of several tumor modulators, including XXX, and this decrease was countered by miR-942 inhibition.

CONCLUSION

Our study provides experimental evidence for an interaction between SNHG17 and miR-942, which may unveil a new approach for PC pharmacotherapy.

A Comprehensive miRNome Analysis of Macrophages Isolated from db/db Mice and Selected miRNAs Involved in Metabolic Syndrome-Associated Cardiac Remodeling

Cardiac macrophages are known from various activities, therefore we presume that microRNAs (miRNAs) produced or released by macrophages in cardiac tissue have impact on myocardial remodeling in individuals with metabolic syndrome (MetS). We aim to assess the cardiac macrophage miRNA profile by selecting those miRNA molecules that potentially exhibit regulatory functions in MetS-related cardiac remodeling. Cardiac tissue macrophages from control and db/db mice (an animal model of MetS) were counted and sorted with flow cytometry, which yielded two populations: CD45+CD11b+CD64+Ly6Chi and CD45+CD11b+CD64+Ly6Clow. Total RNA was then isolated, and miRNA expression profiles were evaluated with Next Generation Sequencing. We successfully sequenced 1400 miRNAs in both macrophage populations: CD45+CD11b+CD64+Ly6Chi and CD45+CD11b+CD64+Ly6Clow. Among the 1400 miRNAs, about 150 showed different expression levels in control and db/db mice and between these two subpopulations. At least 15 miRNAs are possibly associated with MetS pathology in cardiac tissue due to direct or indirect regulation of the expression of miRNAs for proteins involved in angiogenesis, fibrosis, or inflammation. In this paper, for the first time we describe the miRNA transcription profile in two distinct macrophage populations in MetS-affected cardiac tissue. Although the results are preliminary, the presented data provide a foundation for further studies on intercellular cross-talk/molecular mechanism(s) involved in the regulation of MetS-related cardiac remodeling.