SIRT1 regulates inflammation response of macrophages in sepsis mediated by long noncoding RNA

Overview of pro-inflammatory and pro-survival components in neuroinflammatory signalling and neurodegeneration

Neurodegenerative diseases (NDDs) are identified by the progressive deterioration of neurons and a subsequent decline in cognitive function, creating an enormous burden on the healthcare system globally. Neuroinflammation is an intricate procedure that initiates the immune response in the central nervous system (CNS) and significantly impacts the expansion of NDDs. This study scrutinizes the complicated interaction between neuronal degeneration and neuroinflammation, with an appropriate emphasis on their reciprocal impacts. It also describes how neuroinflammatory reactions in NDDs are controlled by activating certain pro-inflammatory transcription factors, including p38 MAPK, FAF1, Toll-like receptors (TLRs), and STAT3. Alternatively, it evaluates the impact of pro-survival transcription factors, such as the SOCS pathway, YY1, SIRT1, and MEF2, which provide neuroprotective protection against damage triggered by neuroinflammation. Moreover, we study the feasibility of accommodating drug repositioning as a therapeutic approach for treating neuroinflammatory disorders. This suggests the use of existing medications for novel utilization in the treatment of NDDs. Furthermore, the study intends to reveal novel biomarkers of neuroinflammation that contribute fundamental observation for the initial detection and diagnosis of these disorders. This study aims to strengthen therapy interference and augment patient outcomes by combining ongoing data and evaluating novel therapeutic and diagnostic approaches. The goal is to devote the growth of an effective strategy to reducing the impact of neuroinflammation on neuronal protection in NDDs.

Trained immunity-inducing vaccines: Harnessing innate memory for vaccine design and delivery

While the efficacy of many current vaccines is well-established, various factors can diminish their effectiveness, particularly in vulnerable groups. Amidst emerging pandemic threats, enhancing vaccine responses is critical. Our review synthesizes insights from immunology and epidemiology, focusing on the concept of trained immunity (TRIM) and the non-specific effects (NSEs) of vaccines that confer heterologous protection. We elucidate the mechanisms driving TRIM, emphasizing its regulation through metabolic and epigenetic reprogramming in innate immune cells. Notably, we explore the extended protective scope of vaccines like BCG and COVID-19 vaccines against unrelated infections, underscoring their role in reducing neonatal mortality and combating diseases like malaria and yellow fever. We also highlight novel strategies to boost vaccine efficacy, incorporating TRIM inducers into vaccine formulations to enhance both specific and non-specific immune responses. This approach promises significant advancements in vaccine development, aiming to improve global public health outcomes, especially for the elderly and immunocompromised populations.

Resveratrol mitigates miR-212-3p mediated progression of diesel exhaust-induced pulmonary fibrosis by regulating SIRT1/FoxO3

BACKGROUND

Diesel exhaust (DE) exposure contributes to the progression of chronic respiratory diseases and is associated with dysregulation of microRNA expression. The present study aims to investigate the involvement of miRNAs and target genes in DE-induced lung fibrosis.

METHODS

C57BL/6 mice were divided into three groups. Group 1 mice were exposed to filtered air (Control). Group 2 mice were exposed to DE for 30 min per day, 5 days per week, for 8 weeks (DE). Group 3 mice received DE exposure along with resveratrol on alternate days for the last 2 weeks (DE + RES). Mice were sacrificed to isolate RNA from lung tissue for miRNA microarray profiling. Bronchoalveolar lavage fluid and lung tissues were collected for cell count and biochemical analysis.

RESULTS

DE exposure resulted in differential expression of 28 miRNAs with fold change >2 (p < 0.05). The upregulated miR-212-3p was selected for further analysis. Consensus analysis revealed enrichment of SIRT1 in the FoxO pathway, along with a co-annotation of reduced body weight (p < 0.05). A549 cells transfected with a miR-212-3p inhibitor showed a dose-dependent increase in SIRT1 expression, indicating SIRT1 as a direct target. Treatment with resveratrol restored SIRT1 and miR-212-3p expression and led to a reduction in inflammatory cytokines (p < 0.05). The modulation of SIRT1 correlated negatively with macrophage infiltration, confirming its role in regulating cellular infiltration and lung inflammation. Fibronectin, alpha-SMA, and collagen levels were significantly decreased in DE + RES compared to DE group suggesting modulation of cellular functions and resolution of lung fibrosis. Furthermore, a significant decrease in FoxO3a and TGF-β gene expressions was observed upon resveratrol administration thereby downregulating pro-fibrotic pathway.

CONCLUSIONS

The present study demonstrates resveratrol treatment stabilizes SIRT1 gene expression by attenuating miR-212-3p in DE-exposed mice, leading to downregulation of TGF-β and FoxO3a expressions. The study highlights the therapeutic role of resveratrol in the treatment of DE-induced pulmonary fibrosis.

RNF7 Induces Skeletal Muscle Cell Apoptosis and Arrests Cell Autophagy via Upregulation of THBS1 and Inactivation of the PI3K/Akt Signaling Pathway in a Rat Sepsis Model

Recently, long noncoding RNAs (lncRNAs) have been highlighted for extensive functionality in sepsis. In this study, we aimed to explore the role of RNF7 in the progression of sepsis. We initially established a rat model of sepsis through cecal ligation and puncture induction, whereupon RNF7 expression was determined by RT-qPCR. Following adenovirus infection, the role of RNF7 in muscle injury, skeletal muscle protein metabolism, oxidative stress, and inflammation in sepsis rats was analyzed. Then, downstream mechanisms of RNF7 were identified and validated. Further, lipopolysaccharide was applied to treat myoblast to further demonstrate the in vitro role of RNF7. Our results showed that RNF7 expression was upregulated during sepsis. Overexpression of RNF7 worsened the sepsis-induced skeletal muscle injury, induced skeletal muscle protein metabolism, oxidative stress, and inflammation in sepsis rats. Meanwhile, overexpression of RNF7 elevated thrombospondin-1 (THBS1) expression. Silencing of RNF7 inhibited THBS1 and activated the PI3K/Akt signaling pathway, arresting the release of inflammatory factors and oxidative stress levels in skeletal muscle cells. Altogether, RNF7 may promote skeletal muscle cell apoptosis while simultaneously inhibiting cell autophagy through the promotion of THBS1 and inactivation of the PI3K/Akt signaling pathway.

SIRT1 pathway in Parkinson's disease: a faraway snapshot but so close

Silent information regulator (SIRT) has distinctive enzymatic activities and physiological functions to control cell-cycle progression, gene expression, and DNA stability by targeting histone and non-histone proteins. SIRT1 enhances synaptic formation and synaptic activity, and therefore, can reduce the progression of various degenerative brain diseases including Parkinson's disease (PD). SIRT1 activity is decreased by aging with a subsequent increased risk for the development of degenerative brain diseases. Inhibition of SIRT1 promotes inflammatory reactions since SIRT1 inhibits transcription of nuclear factor kappa B (NF-κB) which also inhibits SIRT1 activation via activation of microRNA and miR-34a which reduce NAD synthesis. SIRT1 is highly expressed in microglia as well as neurons, and has antioxidant and anti-inflammatory effects. Therefore, this review aimed to find the possible role of SIRT1 in PD neuropathology. SIRT1 has neuroprotective effects; therefore, downregulation of SIRT1 during aging promotes p53 expression and may increase the vulnerability of neuronal cell deaths. PD neuropathology is linked with the sequence of inflammatory changes and the release of pro-inflammatory cytokines due to the activation of inflammatory signaling pathways. In addition, oxidative stress, inflammatory disorders, mitochondrial dysfunction, and apoptosis contribute mutually to PD neuropathology. Thus, SIRT1 and SIRT1 activators play a crucial role in the mitigation of PD neuropathology through the amelioration of oxidative stress, inflammatory disorders, mitochondrial dysfunction, apoptosis, and inflammatory signaling pathways.

Suppression of lncRNA GAS6-AS2 alleviates sepsis-related acute kidney injury through regulating the miR-136-5p/OXSR1 axis in vitro and in vivo

Acute kidney injury (AKI) is a common complication of sepsis and increase morbidity and mortality. Long non-coding RNA (LncRNA) GAS6-AS2 was related to inflammation and apoptosis in different diseases by regulating miRNAs and downstream genes, but its role in AKI remains unclear. Thus, we speculated that GAS6-AS2 might function in sepsis-related AKI via regulating target genes. Here, LPS or CLP was used to establish in vitro or in vivo sepsis-related AKI model. The interactions between GAS6-AS2 and miR-136-5p, and miR-136-5p and OXSR1, were validated by luciferase reporter assay, RNA pull-down, or RIP assay. Cell apoptosis was determined by flow cytometry, Western blotting, or IHC. The kidney injury was evaluated by H&E staining. The expression of GAS6-AS2, miR-136-5p, and OXSR1 was determined by qRT-PCR or Western blotting. We found that GAS6-AS2 was up-regulated in LPS-treated HK2 cells and the CLP-induced rat model. In vitro, GAS6-AS2 knockdown decreased cleaved caspase-3 and bax expression and increased bcl-2 expression. The levels of TNF-α, IL-1β, and IL-6 were reduced by GAS6-AS2 down-regulation. GAS6-AS2 knockdown ameliorated oxidative stress in the cells, as indicated by the reduced ROS and MDA levels and the elevated SOD level. In vivo, GAS6-AS2 down-regulation decreased urinary NGAL and Kim-1 levels and serum sCr and BUN levels, and H&E proved that the kidney injury was alleviated. GAS6-AS2 knockdown also reduced apoptosis, inflammation, and oxidation induced by CLP in vivo. Mechanically, GAS6-AS2 sponged miR-136-5p which targeted OXSR1. Overall, lncRNA GAS6-AS2 knockdown has the potential to ameliorate sepsis-related AKI, and the mechanism is related to miR-136-5p/OXSR1 axis.

Connections between metabolism and epigenetics: mechanisms and novel anti-cancer strategy

Cancer cells undergo metabolic adaptations to sustain their growth and proliferation under several stress conditions thereby displaying metabolic plasticity. Epigenetic modification is known to occur at the DNA, histone, and RNA level, which can alter chromatin state. For almost a century, our focus in cancer biology is dominated by oncogenic mutations. Until recently, the connection between metabolism and epigenetics in a reciprocal manner was spotlighted. Explicitly, several metabolites serve as substrates and co-factors of epigenetic enzymes to carry out post-translational modifications of DNA and histone. Genetic mutations in metabolic enzymes facilitate the production of oncometabolites that ultimately impact epigenetics. Numerous evidences also indicate epigenome is sensitive to cancer metabolism. Conversely, epigenetic dysfunction is certified to alter metabolic enzymes leading to tumorigenesis. Further, the bidirectional relationship between epigenetics and metabolism can impact directly and indirectly on immune microenvironment, which might create a new avenue for drug discovery. Here we summarize the effects of metabolism reprogramming on epigenetic modification, and vice versa; and the latest advances in targeting metabolism-epigenetic crosstalk. We also discuss the principles linking cancer metabolism, epigenetics and immunity, and seek optimal immunotherapy-based combinations.

SIRT1 ameliorated septic associated-lung injury and macrophages apoptosis via inhibiting endoplasmic reticulum stress

BACKGROUND

The inappropriate apoptosis of macrophages plays an important role in the pathogenesis of sepsis-induced acute lung injury, however, the detailed regulatory mechanisms remain largely unknown. As an endogenous apoptosis pathway, endoplasmic reticulum (ER) stress plays an important role in cell damage in patients with sepsis. Clarifying the ER stress response and its effect on macrophages during the development of sepsis is helpful to explore new strategies for the prevention and treatment of ALI in sepsis.

METHODS

The mouse model and the RAW264.7 inflammation model were stimulated with LPS to establish in vivo and in vitro. We explored the effects of different expression levels of silent information regulator factor 2-related enzyme 1 (SIRT1) on the ER stress response and apoptosis of macrophages in the sepsis-related injury model.

RESULTS

Our studies found that the increased expression of SIRT1 can significantly improve sepsis-related lung injury and relieve lung inflammation. SRT1720, a SIRT1 activator, can significantly inhibit the ER stress response of lung tissue and macrophages, inhibit the expression of pro-apoptotic proteins, promote the expression of anti-apoptotic proteins, and reduce macrophages of apoptosis. While the EX527, an inhibitor of SIRT1, had the opposite effect.

CONCLUSION

SIRT1 can significantly improve sepsis-associated lung injury and LPS-induced macrophage apoptosis. This protective effect is closely related to its inhibition of the ER stress response via the PERK/eIF2-α/ATF4/CHOP pathway.

LncRNA small nucleolar RNA host gene 16 reduces sepsis-induced myocardial damage by regulating miR-421/suppressor of cytokine signaling 5 axis

Currently, sepsis-induced cardiomyopathy (SIC) remains as one of the most critical clinical syndromes in terminally ill patients. Noncoding RNAs (including microRNAs and long noncoding RNAs) are implicated in both the onset and development of SIC. We herein investigated the functional role and molecular target of long noncoding RNA small nucleolar RNA host gene 16 (SNHG16) in an in vitro SIC model of H9c2 myocardial cells. We used lipopolysaccharide (LPS) as endotoxin to treat H9c2 cells to mimic SIC damages. Cell Counting Kit 8 and apoptosis assay were performed to assess cell proliferation and cell death. Quantitative real-time-PCR and Western blot were employed to examine gene expression level at mRNA and protein level. Dual luciferase assay is used to validate the functional interactions between SNHG16/mi-R421 and miR-421/suppressor of cytokine signaling 5 (SOCS5). Inflammatory cytokines were measured by ELISA. Superoxide dismutase and malondialdehyde measurement was performed to assess oxidative stress, which was further confirmed by 2',7'-dichlorofluorescin diacetate staining. Our data demonstrated that in the LPS-induced sepsis model of myocardial cells, SNHG16 overexpression downregulated the expression level of miR-421, which sustained the expression of SOCS5 to alleviate the adverse effects of LPS, such as apoptosis, pro-inflammatory cytokines, and oxidative stress. Our data suggest that SNHG16 functions as a ceRNA to maintain SOCS5 level by targeting miR-421, thereby attenuating LPS-induced myocardial cell damages. Targeting miR-421 or modulating lncRNA SNHG16 level may be leveraged as a beneficial strategy against sepsis-induced cellular damage in cardiomyocytes.

lncRNA GMDS‑AS1 upregulates IL‑6, TNF‑α and IL‑1β, and induces apoptosis in human monocytic THP‑1 cells via miR‑96‑5p/caspase 2 signaling

Long non-coding RNA (lncRNA) is considered a crucial modulator of the initiation and progression of several diseases. However, the roles of lncRNA in sepsis have yet to be fully elucidated. Thus, the aim of the present study was to investigate the effects of the lncRNA GDP-mannose 4,6-dehydratase antisense 1 (GMDS-AS1) and its target in order to understand its role in the pathogenesis of sepsis. An in vitro sepsis model was established by lipopolysaccharide (LPS) induction. Reverse transcription-quantitative PCR analysis was applied to detect the expression of inflammatory cytokines and the levels of GMDS-AS1, microRNA (miR)-96-5p and caspase-2 (CASP2). Flow cytometry was used to quantify the rate of apoptosis. In addition, the interaction between miR-96-5p and CASP2 was verified using a luciferase reporter assay. Western blot analysis was performed to assess the protein levels of CASP2 following alterations in GMDS-AS1 and miR-96-5p expression using transfection. The levels of interleukin (IL)-6, tumor necrosis factor-α and IL-1β were increased by LPS treatment in THP-1 cells, whereas miR-96-5p expression was downregulated. miR-96-5p overexpression inhibited LPS-induced inflammatory responses and apoptosis. In addition, GMDS-AS1 expression increased, and upregulation of GMDS-AS1 inhibited, the expression of miR-96-5p in the in vitro sepsis model. Moreover, CASP2 was confirmed to be a direct target of miR-96-5p. Therefore, the lncRNA GMDS-AS1 regulated inflammatory responses and apoptosis by modulating CASP2 and sponging miR-96-5p in LPS-induced THP-1 cells. In summary, the findings of the present study demonstrated that lncRNA GMDS-AS1 could promote the development of sepsis by targeting miR-96-5p/CASP2, indicating that the GMDS-AS1/miR-96-5p/CASP2 axis may be a new therapeutic target and potential research direction for sepsis therapy.

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.

Long Noncoding RNAs Regulate the Inflammatory Responses of Macrophages

Long noncoding RNAs (lncRNAs) are defined as transcripts with more than 200 nucleotides that have little or no coding potential. In recent years, due to the development of next-generation sequencing (NGS), a large number of studies have revealed that lncRNAs function as key regulators to maintain immune balance and participate in diverse physiological and pathological processes in the human body. Notably, overwhelming evidence suggests that lncRNAs can regulate innate immune responses, the differentiation and development of immune cells, inflammatory autoimmune diseases, and many other immunological processes with distinct regulatory mechanisms. In this review, we summarized the emerging roles of lncRNAs in macrophage development and polarization. In addition, the potential value of lncRNAs as diagnostic biomarkers and novel therapeutic targets for the treatment of aberrant immune responses and inflammatory diseases are discussed.

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 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.

Identification of inflammation related lncRNAs and Gm33647 as a potential regulator in septic acute lung injury

Sepsis is commonly complicated by acute lung injury (ALI). We aimed to determine the long non-coding RNAs (lncRNAs) and mRNAs expression profiles. Septic acute lung injury mouse model was established by cecal ligation and puncture. LPS was applied to induce inflammation in mouse alveolar macrophages (MH-s). Besides, LPS/Nigericin sodium salt was used to activate inflammasome in MH-s. LncRNA and mRNA profiles were detected using an Agilent microarray and identified by qPCR. Bioinformatic analyses were employed to analyze the expression profiles and multiple biological functions. Inflammation-related mRNAs were selected according to KEGG pathways and GO terms including inflammation response, immune response and cytokine activity. A network of inflammation related mRNAs and co-expressed lncRNAs was conducted. Finally, Gm33647 was identified as potential regulator in septic acute lung injury. Gm33647 was knock-downed via siRNA to explore functions. The results showed 353 differentially expressed lncRNAs and 3116 differentially expressed mRNAs were identified. Co-expression networks of lncRNA-mRNA showed Gm33647 was a hub gene. Cis- and trans-regulation analyses revealed Gm41442, Gm38850 and Gm36841 could function as a network in septic ALI. LncRNA Gm33647 was reduced by LPS and increased by inflammasome activation in MH-s. Silencing Gm33647 up-regulated IL-6, IL10 and TNF-α in MH-s. When inflammasome was activated by LPS/Nigericin sodium salt, IL-1β, IL-18 and Caspase 1 were increased by silencing Gm33647 in MH-s. These results identified inflammation related lncRNAs and Gm33647 as potential regulators in septic ALI.

Inorganic material based macrophage regulation for cancer therapy: basic concepts and recent advances

Macrophages with the M1 phenotype are a type of immune cell with exciting prospects for cancer therapy; however, when these macrophages infiltrate into tumours, many of them are induced by the tumour microenvironment to transform into the M2 type, which can enable tumour defence against external therapeutic strategies, assisting in tumour development. Macrophages have strong plasticity and functional heterogeneity, and their phenotypic transformation is complex and still poorly understood in relation to cancer therapy. Recent material advances in inorganic nanomaterials, especially inorganic elements in vivo, have accelerated the development of macrophage regulation-based cancer treatments. This review summarizes the basics of recent research on macrophage phenotype transformation and discusses the current challenges in macrophage type regulation. Then, the current achievements involving inorganic material-based macrophage regulation and the related anticancer effects of induced macrophages and their extracellular secretions are reviewed systematically. Importantly, inorganic nanomaterial-based macrophage phenotype regulation is flexible and can be adapted for different types of cancer therapies, presenting a possible novel approach for the generation of immune materials for cancer therapy.

Long noncoding RNAs in bacterial infection

Infectious and inflammatory diseases remain major causes of mortality and morbidity worldwide. To combat bacterial infections, the mammalian immune system employs a myriad of regulators, which secure the effective initiation of inflammatory responses while preventing pathologies due to overshooting immunity. Recently, the human genome has been shown to be pervasively transcribed and to generate thousands of still poorly characterized long noncoding RNAs (lncRNAs). A growing body of literature suggests that lncRNAs play important roles in the regulatory circuitries controlling innate and adaptive immune responses to bacterial pathogens. This review provides an overview of the roles of lncRNAs in the interaction of human and rodent host cells with bacterial pathogens. Further decoding of the lncRNA networks that underlie pathological inflammation and immune subversion could provide new insights into the host cell mechanisms and microbial strategies that determine the outcome of bacterial infections. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications.

lncRNA GAS5‑mediated miR‑23a‑3p promotes inflammation and cell apoptosis by targeting TLR4 in a cell model of sepsis

Sepsis is a syndrome characterized by organ dysfunction and an abnormal immune response to infection. A growing body of research has shown the importance of long non-coding RNAs (lncRNAs) in tumorigenesis, virus replication, inflammatory injury and other pathological processes. The aim of the present study was to explore the role and potential mechanism of the lncRNA growth arrest-specific 5 (GAS5) in the lipopolysaccharide (LPS)-induced inflammation and apoptosis of THP-1 cells. An in vitro sepsis model was established by treating THP-1 cells with LPS. Apoptosis was detected by flow cytometry. The expression levels of IL-6, IL-1β and TNF-α were detected using reverse transcription-quantitative PCR (RT-qPCR) and ELISA, and those of GAS5, microRNA (miR)-23a-3p and Toll-like receptor 4 (TLR4) were detected by RT-qPCR. The changes in the biological activity of THP-1 cells induced by the silencing of GAS5 and overexpression of miR-23a-3p and TLR4 were investigated. The relationships among GAS5, miR-23a-3p and TLR4 were analyzed using luciferase reporter assays. The results revealed that LPS increased the expression of GAS5 in THP-1 cells, and GAS5 knockdown effectively inhibited inflammation and cell apoptosis in the LPS-induced sepsis model. In addition, the results of the luciferase reporter assays indicated that both GAS5 and TLR4 directly target miR-23a-3p. The expression of miR-23a-3p was downregulated whereas that of TLR4 was upregulated in the septic cells. Further experiments showed that the overexpression of TLR4 attenuated the suppressive effects of miR-23a-3p overexpression and GAS5 knockdown on LPS-induced inflammation and apoptosis. In conclusion, the present study indicates that GAS5 strengthens LPS-induced inflammation and apoptosis via the miR-23a-3p/TLR4 pathway.

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.

LncRNA: A Potential Research Direction in Intestinal Barrier Function

Long non-coding RNAs (lncRNAs) are transcripts longer than 200 nucleotides and play important roles in a variety of diseases. LncRNAs are involved in many biologic processes including cell differentiation, development, and apoptosis. The intestinal barrier is considered one of the most important protective barriers in humans. Severe damage or dysfunction of the intestinal barrier may be associated with the occurrence and development of many diseases, such as inflammatory bowel disease and ulcerative colitis. LncRNAs have been found to be associated with intestinal barrier function in some studies, which are at an early stage. In this review, we introduce the roles of LncRNAs in the intestinal barrier and investigate the possibility of lncRNAs as a research field in the intestinal barrier.

Targeting STAT3: A crucial modulator of sepsis

Signal transducer and activator of transcription 3 (STAT3) is a cellular signal transcription factor that has recently attracted a great deal of attention. It can trigger a variety of genes transcription in response to cytokines and growth factors stimulation, which plays an important role in many cellular biological processes involved in anti/proinflammatory responses. Sepsis is a life-threatening organ dysfunction resulting from dysregulated host responses to infection. As a converging point of multiple inflammatory responses pathways, accumulating studies have presented the elaborate network of STAT3 in sepsis pathophysiology; these results generally indicate a promising therapeutic application for targeting STAT3 in the treatment of sepsis. In the present review, we evaluated the published literature describing the use of STAT3 in the treatment of experimental and clinical sepsis. The information presented here may be useful for the design of future studies and may highlight the potential of STAT3 as a future biomarker and therapeutic target for sepsis.

Targeting Sirtuin 1 signaling pathway by ginsenosides

ETHNOPHARMACOLOGICAL RELEVANCE

Ginseng is a kind of traditional Chinese herbal medicine, known as "king of herbs" and widely used in China, South Korea, and other Asian countries. Ginsenosides are one of active components of Panax ginseng Meyer, which have many pharmacological effects, such as enhancing memory, improving immunity and cardiovascular system, delaying aging, and preventing cancer.

AIMS OF THE REVIEW

This review aims to summarize the recent findings for ginsenosides targeting Sirtuin 1 (SIRT1) signaling pathway for the prevention and treatment of a series of diseases.

MATERIALS AND METHODS

An up-to-August 2020 search was carried out in databases such as PubMed, ScienceDirect, Google Scholar, China National Knowledge Infrastructure, and classic books of traditional Chinese medicine using the keywords: "SIRT1", and/or paired with "ginseng", and "ginsenosides".

RESULTS

SIRT1 is a class-III histone deacetylase (HDAC), a nicotinamide adenine dinucleotide (NAD⁺)-dependent enzyme, which is deeply involved in a series of pathological processes. Based on specific intracellular localization, SIRT1 has various cytoplasmic and nuclear targets and plays a potential role in energy metabolism, oxidative stress, inflammation, tumorigenesis, and aging. Ginsenosides are generally classified into three groups and microbially transformed to final metabolites. Among of them, most ginsenosides have been reported as SIRT1 activators, especially those ginsenosides with two glucopyranosyl groups on the C-3 position. Importantly, many ginsenosides can be used to prevent and treat oxidative stress, inflammation, aging, tumorigenesis, depression, and others by targeting SIRT1 signaling pathway.

CONCLUSIONS

This paper reviews recent evidences of ginsenosides targeting SIRT1 for the first time, which could provide new insights on the preclinical and clinical researches for ginsenosides against multiple disorders.

Recent advances in the regulation of ABCA1 and ABCG1 by lncRNAs

Coronary heart disease (CHD) with atherosclerosis is the leading cause of death worldwide. ABCA1 and ABCG1 promote cholesterol efflux to suppress foam cell generation and reduce atherosclerosis development. Long noncoding RNAs (lncRNAs) are emerging as a unique group of RNA transcripts that longer than 200 nucleotides and have no protein-coding potential. Many studies have found that lncRNAs regulate cholesterol efflux to influence atherosclerosis development. ABCA1 is regulated by different lncRNAs, including MeXis, GAS5, TUG1, MEG3, MALAT1, Lnc-HC, RP5-833A20.1, LOXL1-AS1, CHROME, DAPK1-IT1, SIRT1 AS lncRNA, DYNLRB2-2, DANCR, LeXis, LOC286367, and LncOR13C9. ABCG1 is also regulated by different lncRNAs, including TUG1, GAS5, RP5-833A20.1, DYNLRB2-2, ENST00000602558.1, and AC096664.3. Thus, various lncRNAs are associated with the roles of ABCA1 and ABCG1 on cholesterol efflux in atherosclerosis regulation. However, some lncRNAs play dual roles in ABCA1 expression and atherosclerosis, and the functions of some lncRNAs in atherosclerosis have not been investigated in vivo. In this article, we review the roles of lncRNAs in atherosclerosis and focus on new insights into lncRNAs associated with the roles of ABCA1 and ABCG1 on cholesterol efflux and the potential of these lncRNAs as novel therapeutic targets in atherosclerosis.

Profiles of differentially expressed long noncoding RNAs and messenger RNAs in the myocardium of septic mice

Background

Sepsis is the primary cause of mortality in the intensive care unit (ICU), mainly due to sepsis-induced dysfunction of essential organs such as the heart and lungs. This study investigated the myocardium's epigenetic characterization from septic mice to identify potential treatment targets for septic myocardial dysfunction.

Methods

Cecal ligation and puncture (CLP) was used to induce sepsis in male C57BL/6 mice. Hearts were collected 24 h after surgery to determine the expression profiles of long noncoding RNAs (lncRNAs) and messenger RNAs (mRNAs) by microarray. To validate the reliability of microarray results, we randomly chose six differentially expressed lncRNAs for qRT-PCR. Functional mapping of differentially expressed mRNAs was annotated with gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses; lncRNA-mRNA co-expression network was constructed to reveal connections between lncRNAs and mRNAs.

Results

Microarray analysis indicated that 1,568 lncRNAs and 2,166 mRNAs were differentially expressed in the myocardium from septic mice, which was further confirmed by qRT-PCR. KEGG pathway analysis showed that numerous differentially expressed mRNAs were relevant to tumor necrosis factor (TNF) and phosphatidylinositol-3-kinase/protein kinase B (PI3K/Akt) signaling pathways. Moreover, according to the lncRNA-mRNA co-expression network constructed by the above six lncRNAs and their interacting mRNAs, the co-expression network profiles had 57 network nodes and 134 connections, including 76 positive interactions and 58 negative interactions.

Conclusions

In mouse hearts, sepsis resulted in differential expression of lncRNAs and mRNAs related to TNF and PI3K-Akt signaling pathways, suggesting that lncRNAs and their interacting mRNAs may participate in the pathogenesis of septic myocardial dysfunction by regulating TNF and PI3K-Akt signaling pathways.

Long Noncoding RNA THAP9-AS1 and TSPOAP1-AS1 Provide Potential Diagnostic Signatures for Pediatric Septic Shock

Background

Sepsis is a systemic inflammatory syndrome caused by infection with a high incidence and mortality. Although long noncoding RNAs have been identified to be closely involved in many inflammatory diseases, little is known about the role of lncRNAs in pediatric septic shock.

Methods

We downloaded the mRNA profiles GSE13904 and GSE4607, of which GSE13904 includes 106 blood samples of pediatric patients with septic shock and 18 health control samples; GSE4607 includes 69 blood samples of pediatric patients with septic shock and 15 health control samples. The differentially expressed lncRNAs were identified through the limma R package; meanwhile, GO terms and KEGG pathway enrichment analysis was performed via the clusterProfiler R package. The protein-protein interaction (PPI) network was constructed based on the STRING database using the targets of differently expressed lncRNAs. The MCODE plug-in of Cytoscape was used to screen significant clustering modules composed of key genes. Finally, stepwise regression analysis was performed to screen the optimal lncRNAs and construct the logistic regression model, and the ROC curve was applied to evaluate the accuracy of the model.

Results

A total of 13 lncRNAs which simultaneously exhibited significant differences in the septic shock group compared with the control group from two sets were identified. According to the 18 targets of differentially expressed lncRNAs, we identified some inflammatory and immune response-related pathways. In addition, several target mRNAs were predicted to be potentially involved in the occurrence of septic shock. The logistic regression model constructed based on two optimal lncRNAs THAP9-AS1 and TSPOAP1-AS1 could efficiently separate samples with septic shock from normal controls.

Conclusion

In summary, a predictive model based on the lncRNAs THAP9-AS1 and TSPOAP1-AS1 provided novel lightings on diagnostic research of septic shock.

Silencing of lncRNA MIAT alleviates LPS-induced pneumonia via regulating miR-147a/NKAP/NF-κB axis

Purpose: Pneumonia is a respiratory disease with an increasing incidence in recent years. More and more studies have revealed that lncRNAs can regulate the transcriptional expression of target genes at different stage. Herein, we aimed to explore the effect of lncRNA MIAT in LPS-induced pneumonia, and further illuminate the possible underlying mechanisms.

Method and results: Mice were intraperitoneally injected with LPS, and the lung inflammation was evaluated. Microarray showed lncRNA MIAT was up-regulated in LPS-induced pulmonary inflammation. And qRT-PCR and FISH assay indicated that MIAT was increased in mice with LPS injection. Functional analysis showed sh-MIAT inhibited LPS-induced inflammation response, inhibited apoptosis level and protected lung function. As well, si-MIAT removed the injury of LPS on mouse lung epithelial TC-1 cells, and inhibited the activation of NF-κB signaling. Furthermore, MIAT acted as a sponge of miR-147a, and miR-147a directly targeted NKAP. Functionally, AMO-147a or NKAP remitted the beneficial effects of si-MIAT on LPS-induced inflammation response of TC-1 cells.

Conclusion: Deletion of MIAT protected against LPS-induced lung inflammation via regulating miR-147a/NKAP, which might provide new insight for pneumonia treatment.

The Intersection of Epigenetics and Metabolism in Trained Immunity

The last few years have witnessed an increasing body of evidence that challenges the traditional view that immunological memory is an exclusive trait of the adaptive immune system. Myeloid cells can show increased responsiveness upon subsequent stimulation with the same or a different stimulus, well after the initial challenge. This de facto innate immune memory has been termed "trained immunity" and is involved in infections, vaccination and inflammatory diseases. Trained immunity is based on two main pillars: the epigenetic and metabolic reprogramming of cells. In this review we discuss the latest insights into the epigenetic mechanisms behind the induction of trained immunity, as well as the role of different cellular metabolites and metabolic networks in the induction, regulation and maintenance of trained immunity.

The role of lncRNAs in innate immunity and inflammation

The innate immune system relies on a germ-line-encoded repertoire of pattern recognition receptors (PRRs), activated by deeply conserved pathogen signatures, such as bacterial cell wall components or foreign nucleic acids. To enable effective defence against invading pathogens and prevent from deleterious inflammation, PRR-driven immune responses are tightly controlled by a dense network of nuclear and cytoplasmic regulators. Long non-coding RNAs (lncRNAs) are increasingly recognized as important components of these regulatory circuitries, providing positive and negative control of PRR-induced innate immune responses. The present review provides an overview of the presently known roles of lncRNAs in human and murine innate antiviral and antibacterial immunity. The emerging roles in host defence and inflammation suggest that further mechanistic insights into the cellular functions of lncRNAs will decisively advance our molecular understanding of immune-associated diseases and open new avenues for therapeutic intervention.

Shikonin Ameliorates LPS-Induced Cardiac Dysfunction by SIRT1-Dependent Inhibition of NLRP3 Inflammasome

Shikonin (SHI) is an anti-inflammatory agent extracted from natural herbs. It is still unknown whether SHI ameliorates lipopolysaccharide (LPS)-induced cardiac dysfunction. This study aims to explore the protective effects of SHI on LPS-induced myocardial injury and its mechanism. The LPS-induced cardiac dysfunction mouse model was employed to investigate the protective effects of SHI. In the present study, we found that SHI treatment improved the survival rate and cardiac function and remarkably ameliorated the release of inflammatory cytokines and macrophage infiltration in heart tissue of LPS-treated mice. SHI also reduced lactate dehydrogenase (LDH) and cardiac troponin (cTn) release, cell inflammation, and apoptosis in LPS plus adenosine triphosphate (ATP)-treated H9c2 cells. In addition, SHI significantly upregulated silent information regulator 1 (SIRT1) expression and suppressed the upregulation of NOD-like receptor protein 3 (NLRP3), cleaved caspase-1, and caspase-1 activity in heart tissues induced by LPS. Meanwhile, we got the same results in LPS plus ATP-treated H9c2 cells in vitro. Further, SIRT1 inhibitor or siRNA partially blocked SHI-mediated upregulation of SIRT1 expression and downregulation of NLRP3, cleaved caspase-1, and caspase-1 activity in heart tissues induced by LPS. Therefore, we conclude that SHI ameliorates LPS-induced cardiac dysfunction by inhibiting SIRT1-dependent activation of NLRP3 inflammasomes and might be a promising therapeutic strategy for the treatment of LPS-induced cardiac dysfunction.

Involvement of lncRNAs and Macrophages: Potential Regulatory Link to Angiogenesis

Macrophages are involved in angiogenesis, an essential process for organ growth and tissue repair, and could contribute to the pathogenesis of angiogenesis-related diseases such as malignant tumors and diabetic retinopathy. Recently, long noncoding RNAs (lncRNAs) have been proved to be important in cell differentiation, organismal development, and various diseases of pathological angiogenesis. Moreover, it has been indicated that numerous lncRNAs exhibit different functions in macrophage infiltration and polarization and regulate the secretion of inflammatory cytokines released by macrophages. Therefore, the focus of macrophage-related lncRNAs could be considered to be a potential method in therapeutic targeting angiogenesis-related diseases. This review mainly summarizes the roles played by lncRNAs which associated with macrophages in angiogenesis. The possible mechanisms of the regulatory link between lncRNAs and macrophages in various angiogenesis-related diseases were also discussed.

LncRNA KCNQ1OT1 attenuates sepsis-induced myocardial injury via regulating miR-192-5p/XIAP axis

Myocardial dysfunction is a prime cause of death in sepsis. This study is to delve into the function of lncRNA KCNQ1OT1 in myocardial injury induced by sepsis. Sepsis-induced myocardial injury model in rat was initiated by intraperitoneally injecting of LPS (10 mg/kg) in vivo, and cardiomyocyte H9c2 was treated with LPS to mimic sepsis in vitro. KCNQ1OT1 and miR-192-5p expressions were detected by qRT-PCR. The cell viability was probed with CCK-8 experiment and the apoptosis of the cardiomyocytes was tested using flow cytometry analysis. Western blot was operated to determine apoptosis-related proteins expressions. ELISA was used to evaluate the levels of TNF-α, IL-6, and IL-1β. Bioinformatics analysis, RT-PCR, dual luciferase reporter assay, and RNA immunoprecipitation experiment were utilized to detect the interrelation of genes. Herein, we proved that KCNQ1OT1 was considerably down-regulated, whereas miR-192-5p was markedly increased in myocardial tissues of septic rats. KCNQ1OT1 interrelated with miR-192-5p, and negatively modulated its expression levels. Overexpression of KCNQ1OT1 or the transfection of miR-192-5p inhibitors greatly facilitated the viability and impeded the apoptosis of H9c2 cardiomyocytes. miR-192-5p paired with the 3ʹUTR of XIAP, and repressed its protein expression, and XIAP was modulated positively by KCNQ1OT1. In conclusion, our work indicates that down-regulation of KCNQ1OT1 advances cardiac injury through regulating miR-192-5p/XIAP axis during sepsis.

Impact statement

Sepsis-induced cardiomyopathy remains to be a major challenge to health care systems around the globe. There are no known therapies currently available that can cure the disease. This study provides convincing evidence that KCNQ1OT1 could attenuate sepsis-mediated myocardial injury. We further demonstrate that the beneficial function of KCNQ1OT1 was achieved by regulating the miR-192-5p/XIAP axis. We therefore found a new mechanism of cardioprotective effect of KCNQ1OT1, one which also offers a novel theoretical basis for the therapy of sepsis-induced cardiomyopathy.

Long noncoding RNA colorectal neoplasia differentially expressed alleviates sepsis-induced liver injury via regulating miR-126-5p

In this study, we intended to determine the detailed function and mechanism of long noncoding RNA (lncRNA) colorectal neoplasia differentially expressed (CRNDE) in liver injury induced by sepsis. Cecal ligation and perforation (CLP) models were adopted to induce sepsis in vivo with rats, and hepatic epithelial cells L02 were treated with lipopolysaccharide (LPS) to mimic sepsis in vitro. Enzyme-linked immunosorbent assay was conducted to detect the levels of tumor necrosis factor (TNF-α), interleukin-6 (IL-6), interleukin-10 (IL-10), and interferon-γ (IFN-γ) in the serum of rats. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to measure the expressions of CRNDE and microRNA-126-5p (miR-126-5p). Flow cytometry analysis and Cell Counting Kit-8 (CCK-8) method were carried out followed by the up- or downregulation of CRNDE and miR-126-5p to monitor the proliferation and apoptosis of L02 cells, respectively. Western blot was then applied to determine the expressions of cysteinyl aspartate specific proteinase 3 (caspase 3), poly(ADP-ribose)polymerase (PARP), cytochrome c, and BCL2-like 2 (BCL2L2). The interactions between CRNDE with miR-126-5p and miR-126-5p with BCL2L2 were determined through bioinformatics, qRT-PCR, dual luciferase reporter assay, and RNA immunoprecipitation assay. CRNDE was significantly decreased in liver tissues and hepatic cells in sepsis models. Upregulation of CRNDE promoted the viability of L02 cells and inhibited their apoptosis, while downregulation of CRNDE had opposite effects. The expression of CRNDE in liver tissues of septic rats was correlated with the expression miR-126-5p. It was also demonstrated that the transfection of miR-126-5p mimics reversed the inhibitory effect induced by CRNDE on apoptosis of L02 cells. CRNDE could specifically bind to miR-126-5p and reduce its expression, in turn promote the expression of BCL2L2. Additionally, CRNDE overexpression in rats ameliorated liver injury induced by sepsis. Downregulated CRNDE aggravates hepatic injury via regulating miR-126-5p and BCL2L2 during sepsis.

Down-regulation of LncRNA CRNDE aggravates kidney injury via increasing MiR-181a-5p in sepsis

Long non-coding RNA (lncRNA) colorectal neoplasia differentially expressed (CRNDE) is reported to be linked to inflammation and cell apoptosis. However its role in sepsis induced kidney injury remains unclear. This study aims to explore the possible mechanism of CRNDE in kidney injury induced by sepsis. In vivo urine-derived sepsis (US) rat model and in vitro LPS-induced HK-2 and HEK293 cells were established. Kidney function was measured in rats from different groups. Relative levels of tumor necrosis factor-α (TNF-α) and interleukin-1β(IL-1β) in kidney tissue were detected via Enzyme-linked immune sorbent assay (ELISA). Then we up- or down-regulated CRNDE and miRNA-181a-5p expression in the cells. The biological influence of CRNDE and miR-181a-5p on cells was studied using CCK-8 assay and Annexin V assay. Interaction between CRNDE and miR-181a-5p was determined by bioinformatics analysis, RT-PCR, and dual luciferase reporter assay. Peroxisome proliferator-activated receptor-α (PPARα) and cell apoptosis related molecules were detected by western blot. We demonstrated that CRNDE was markedly down-regulated while miR-181a-5p was significantly up-regulated in sepsis models. CRNDE interacted with miR-181a-5p, and negatively regulated its expression level. CRNDE knockdown in rats increased the urea nitrogen and serum creatinine in plasma. Knockdown of CRNDE or transfection of miR-181a-5p significantly inhibited proliferation and promoted apoptosis of HK-2 and HEK293 cells, while overexpression of CRNDE and transfection of miR-181a-5p inhibitors had opposite effects. For mechanism, miR-181a-5p directly targeted the 3' untranslated region of PPARα, and depressed its protein level, and PPARα was regulated indirectly by CRNDE. We concluded that CRNDE protected renal cell from sepsis-induced injury via miR-181a-5p/PPARα pathway.

Long non-coding RNA MALAT1 promotes angiogenesis and immunosuppressive properties of HCC cells by sponging miR-140

Hepatocellular carcinoma (HCC) is the most prevalent primary liver cancer in adults. Previous studies in our laboratory found that long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) was upregulated in HCC cells, which could affect the metastasis and invasion of HCC. However, the underlying mechanism remains unknown. Herein, we studied the interaction between MALAT1 and miR-140 on the regulation of angiogenesis and immunosuppressive properties. We revealed that the expression of MALAT1 and VEGF-A was significantly increased in HCC cells. Knockdown of MALAT1 in HCC cells suppressed the production of VEGF-A, impaired the angiogenesis of HUVECs, and facilitated the polarization of macrophage toward the M1 subset. Mechanistically, the interaction between MALAT1 and miR-140 or between miR-140 and VEGF-A was confirmed by multiple assays. Besides, a negative correlation between MALAT1 and miR-140 was found in HCC tissues. Furthermore, miR-140 inhibition significantly increased VEGF-A expression, promoted angiogenesis of HUVECs, and redirected the polarization of macrophages toward the M2 subset. In addition, in vivo studies also verified the regulatory network of the MALAT1/miR-140 axis on VEGF-A in HCC progression. In summary, this study revealed the mechanism that MALAT1 worked as a putative HCC promotor via inhibiting miR-140. Therefore, targeting MALAT1 or miR-140 might alleviate the progression of HCC in the future.

LncRNA SOX2OT Mediates Mitochondrial Dysfunction in Septic Cardiomyopathy

Researches establish an indispensable role of mitochondrial dysfunction in septic cardiomyopathy. We aimed to investigate the effects of long noncoding RNA (LncRNA) SOX2 overlapping transcript (SOX2OT) on mitochondrial dysfunction in septic cardiomyopathy. We observed an obvious overexpression of SOX2OT in septic hearts and cardiomyocytes. Knockdown of SOX2OT in mice recovered the reduced cardiac function, and improved the mitochondrial membrane potential impaired by lipopolysaccharide (LPS). SOX2OT overexpressed mice showed the opposite situation. In parallel, knockdown of SOX2OT in cardiomyocytes restored the mitochondrial membrane potential, along with reduced mitochondrial reactive oxygen species production induced by LPS, while overexpression of SOX2OT reversed these effects. Mechanistically, SOX2OT could regulate mitochondrial dysfunction in septic cardiomyopathy via SOX2. In general, SOX2OT contributed to mitochondrial dysfunction progression via inhibiting SOX2 expression in septic cardiomyopathy, which may provide a new insight for treatment of septic cardiomyopathy.

Long non-coding RNA expressed in macrophage co-varies with the inflammatory phenotype during macrophage development and polarization

Advances in microarray, RNA‐seq and omics techniques, thousands of long non‐coding RNAs (lncRNAs) with unknown functions have been discovered. LncRNAs have presented a diverse perspective on gene regulation in diverse biological processes, especially in human immune response. Macrophages participate in the whole phase of immune inflammatory response. They are able to shape their phenotype and arouse extensive functional activation after receiving physiological and pathological stimuli. Emerging studies indicated that lncRNAs participated in the gene regulatory network during complex biological processes of macrophage, including macrophage‐induced inflammatory responses. Here, we reviewed the existing knowledges of lncRNAs in the processes of macrophage development and polarization, and their roles in several different inflammatory diseases. Specifically, we focused on how lncRNAs function in macrophage, which might help to discover some potential therapeutic targets and diagnostic biomarkers.

Aging, Melatonin, and the Pro- and Anti-Inflammatory Networks

Aging and various age-related diseases are associated with reductions in melatonin secretion, proinflammatory changes in the immune system, a deteriorating circadian system, and reductions in sirtuin-1 (SIRT1) activity. In non-tumor cells, several effects of melatonin are abolished by inhibiting SIRT1, indicating mediation by SIRT1. Melatonin is, in addition to its circadian and antioxidant roles, an immune stimulatory agent. However, it can act as either a pro- or anti-inflammatory regulator in a context-dependent way. Melatonin can stimulate the release of proinflammatory cytokines and other mediators, but also, under different conditions, it can suppress inflammation-promoting processes such as NO release, activation of cyclooxygenase-2, inflammasome NLRP3, gasdermin D, toll-like receptor-4 and mTOR signaling, and cytokine release by SASP (senescence-associated secretory phenotype), and amyloid-β toxicity. It also activates processes in an anti-inflammatory network, in which SIRT1 activation, upregulation of Nrf2 and downregulation of NF-κB, and release of the anti-inflammatory cytokines IL-4 and IL-10 are involved. A perhaps crucial action may be the promotion of macrophage or microglia polarization in favor of the anti-inflammatory phenotype M2. In addition, many factors of the pro- and anti-inflammatory networks are subject to regulation by microRNAs that either target mRNAs of the respective factors or upregulate them by targeting mRNAs of their inhibitor proteins.

Ginsenoside Rg1 Regulates SIRT1 to Ameliorate Sepsis-Induced Lung Inflammation and Injury via Inhibiting Endoplasmic Reticulum Stress and Inflammation

Objectives

To investigate the protective effect of ginsenoside Rg1 on relieving sepsis-induced lung inflammation and injury in vivo and in vitro.

Methods

Cultured human pulmonary epithelial cell line A549 was challenged with LPS to induce cell injury, and CLP mouse model was generated to mimic clinical condition of systemic sepsis. Rg1 was applied to cells or animals at indicated dosage. Apoptosis of cultured cells was quantified by flow cytometry, along with ELISA for inflammatory cytokines in supernatant. For septic mice, lung tissue pathology was examined, plus ELISA assay for serum cytokines. Western blotting was used to examine the activation of inflammatory pathways and ER stress marker proteins in both cells and mouse lung tissues. Reactive oxygen species (ROS) level was quantified by DCFDA kit.

Results

Ginsenoside Rg1 treatment remarkably suppressed apoptosis rate of LPS-induced A549 cells, relieved mouse lung tissue damage, and elevated survival rate. Rg1 treatment also rescued cells from LPS-induced intracellular ROS. In both A549 cells and mouse lung tissues, further study showed that Rg1 perfusion significantly suppressed the secretion of inflammatory cytokines including tumor necrosis factor- (TNF-) alpha and interleukin- (IL-) 6 and relieved cells from ER stress as supported by decreased expression of marker proteins via upregulating sirtuin 1 (SIRT1).

Conclusion

Our results showed that ginsenoside Rg1 treatment effectively relieved sepsis-induced lung injury in vitro and in vivo, mainly via upregulating SIRT1 to relieve ER stress and inflammation. These findings provide new insights for unrevealing potential candidate for severe sepsis accompanied with lung injury.

Histone Deacetylation Inhibitors as Therapy Concept in Sepsis

Sepsis is characterized by dysregulated gene expression, provoking a hyper-inflammatory response occurring in parallel to a hypo-inflammatory reaction. This is often associated with multi-organ failure, leading to the patient’s death. Therefore, reprogramming of these pro- and anti-inflammatory, as well as immune-response genes which are involved in acute systemic inflammation, is a therapy approach to prevent organ failure and to improve sepsis outcomes. Considering epigenetic, i.e., reversible, modifications of chromatin, not altering the DNA sequence as one tool to adapt the expression profile, inhibition of factors mediating these changes is important. Acetylation of histones by histone acetyltransferases (HATs) and initiating an open-chromatin structure leading to its active transcription is counteracted by histone deacetylases (HDACs). Histone deacetylation triggers a compact nucleosome structure preventing active transcription. Hence, inhibiting the activity of HDACs by specific inhibitors can be used to restore the expression profile of the cells. It can be assumed that HDAC inhibitors will reduce the expression of pro-, as well as anti-inflammatory mediators, which blocks sepsis progression. However, decreased cytokine expression might also be unfavorable, because it can be associated with decreased bacterial clearance.

Melatonin and inflammation-Story of a double-edged blade

Melatonin is an immune modulator that displays both pro- and anti-inflammatory properties. Proinflammatory actions, which are well documented by many studies in isolated cells or leukocyte-derived cell lines, can be assumed to enhance the resistance against pathogens. However, they can be detrimental in autoimmune diseases. Anti-inflammatory actions are of particular medicinal interest, because they are observed in high-grade inflammation such as sepsis, ischemia/reperfusion, and brain injury, and also in low-grade inflammation during aging and in neurodegenerative diseases. The mechanisms contributing to anti-inflammatory effects are manifold and comprise various pathways of secondary signaling. These include numerous antioxidant effects, downregulation of inducible and inhibition of neuronal NO synthases, downregulation of cyclooxygenase-2, inhibition of high-mobility group box-1 signaling and toll-like receptor-4 activation, prevention of inflammasome NLRP3 activation, inhibition of NF-κB activation and upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2). These effects are also reflected by downregulation of proinflammatory and upregulation of anti-inflammatory cytokines. Proinflammatory actions of amyloid-β peptides are reduced by enhancing α-secretase and inhibition of β- and γ-secretases. A particular role in melatonin's actions seems to be associated with the upregulation of sirtuin-1 (SIRT1), which shares various effects known from melatonin and additionally interferes with the signaling by the mechanistic target of rapamycin (mTOR) and Notch, and reduces the expression of the proinflammatory lncRNA-CCL2. The conclusion on a partial mediation by SIRT1 is supported by repeatedly observed inhibitions of melatonin effects by sirtuin inhibitors or knockdown.

LncRNA SNHG16 reverses the effects of miR-15a/16 on LPS-induced inflammatory pathway

Nowadays, neonatal sepsis has gradually become a global problem for its high incidence and increasing mortality. Previous studies have reported that miR-15a and miR-16 are two important modulators in neonatal sepsis. However, the upstream molecular mechanism of miR-15a/16 cluster is still mysterious. This study aims to explore a lncRNA can bind with miR-15a/16 in neonatal sepsis. Microarray analysis helped us found top ten lncRNAs which were downregulated in neonatal sepsis serum. Among these ten lncRNAs, SNHG16 was uncovered to significantly downregulated both miR-15a and miR-16. According to the result of subcellular fractionation assay, SNHG16 was mainly located in the cytoplasm of RAW264.7 cell, indicating the potential ceRNA role of SNHG16. Mechanism investigations revealed that SNHG16 could act as a ceRNA to upregulate TLR4 which is the target mRNA of miR-15a/16 cluster. At last, rescue assays demonstrated that SNHG16 reversed the effects of miR-15a/16 on LPS-induced inflammatory pathway. In summary, SNHG16 can act as a ceRNA to modulate miR-15a/16 cluster, thereby affecting LSP-induced inflammatory pathway which was downregulated by miR-15a/16 cluster.

Emerging role of lncRNAs in the normal and diseased intestinal barrier

OBJECTIVE

A significant effort has been made to understand the intestinal barrier, but the effective means to prevent, reduce, and restore intestinal mucosal damage remains unclear. Recently, a few of studies have explained the mechanism of the intestinal barrier in long noncoding RNAs (lncRNAs). This review aims to summarize recent views on the function of lncRNAs in the intestinal barrier and discuss the emerging role of lncRNAs in intestinal barrier diseases caused by inflammatory diseases.

METHODS

Observations led us to believe that lncRNAs participate in inflammatory responses, cell proliferation, and control microbial susceptibility. In view of these, lncRNAs have been proved to involve in the intestinal barrier.

RESULTS

lncRNAs directly or indirectly affect TJ mRNA translation and intestinal epithelial cells (IECs) paracellular permeability, as well as IECs proliferation and susceptibility to apoptosis, to modulate the function of the intestinal barrier. miRNAs play a pivotal role in this process.

CONCLUSIONS

lncRNAs have been shown to be fundamentally involved in intestinal mucosal regeneration, protection, and epithelial barrier function. It may emerge as new and potential factors to be evaluated in the intestinal barrier diseases caused by acute pancreatitis, inflammatory bowel diseases, and imbalance of intestinal flora.

Long non-coding RNAs regulating macrophage functions in homeostasis and disease

Non-coding RNAs, once considered "genomic junk", are now known to play central roles in the dynamic control of transcriptional and post-transcriptional gene expression. Long non-coding RNAs (lncRNAs) are an expansive class of transcripts broadly described as greater than 200 nucleotides in length. While most lncRNAs are species-specific, their lack of conservation does not imbue a lack of function. LncRNAs have been found to regulate numerous diverse biological functions, including those central to macrophage differentiation and activation. Through their ability to form RNA-DNA, RNA-protein and RNA-RNA interactions, lncRNAs have been implicated in the regulation of myeloid lineage determination, and innate and adaptive immune functions, among others. In this review, we discuss recent advances, current challenges and future opportunities in understanding the roles of lncRNAs in macrophage functions in homeostasis and disease.