Low expression of microRNA-328 can predict sepsis and alleviate sepsis-induced cardiac dysfunction and inflammatory response

MicroRNA-specific therapeutic targets and biomarkers of apoptosis following myocardial ischemia-reperfusion injury

MicroRNAs are single-stranded non-coding RNAs that participate in post-transcriptional regulation of gene expression, it is involved in the regulation of apoptosis after myocardial ischemia-reperfusion injury. For example, the alteration of mitochondrial structure is facilitated by MicroRNA-1 through the regulation of apoptosis-related proteins, such as Bax and Bcl-2, thereby mitigating cardiomyocyte apoptosis. MicroRNA-21 not only modulates the expression of NF-κB to suppress inflammatory signals but also activates the PI3K/AKT pathway to mitigate ischemia-reperfusion injury. Overexpression of MicroRNA-133 attenuates reactive oxygen species (ROS) production and suppressed the oxidative stress response, thereby mitigating cellular apoptosis. MicroRNA-139 modulates the extrinsic death signal of Fas, while MicroRNA-145 regulates endoplasmic reticulum calcium overload, both of which exert regulatory effects on cardiomyocyte apoptosis. Therefore, the article categorizes the molecular mechanisms based on the three classical pathways and multiple signaling pathways of apoptosis. It summarizes the targets and pathways of MicroRNA therapy for ischemia-reperfusion injury and analyzes future research directions.

Neutrophils and the Systemic Inflammatory Response Syndrome (SIRS)

We are not entirely able to understand, assess, and modulate the functioning of the immune system in clinical situations that lead to a systemic inflammatory response. In the search for diagnostic and treatment strategies (which are still far from perfect), it became very important to study the pathogenesis and participation of endogenous inflammation mediators. This study attempts to more precisely establish the role of neutrophils in individual phenomena occurring during an inflammatory and anti-inflammatory reaction, taking into account their cidal, immunoregulatory, and reparative abilities. Pro- and anticoagulatory properties of endothelium in systemic inflammatory response syndrome (SIRS) are emphasised, along with the resulting clinical implications (the application of immunotherapy using mesenchymal stem/stromal cells (MSCs) or IL-6 antagonists in sepsis and COVID-19 treatment, among others). Special attention is paid to reactive oxygen species (ROS), produced by neutrophils activated during "respiratory burst" in the course of SIRS; the protective and pathogenic role of these endogenous mediators is highlighted. Moreover, clinically useful biomarkers of SIRS (neutrophil extracellular traps, cell-free DNA, DAMP, TREMs, NGAL, miRNA, selected cytokines, ROS, and recognised markers of endothelial damage from the group of adhesins by means of immunohistochemical techniques) related to the neutrophils are presented, and their role in the diagnosing and forecasting of sepsis, burn disease, and COVID-19 is emphasised. Finally, examples of immunomodulation of sepsis and antioxidative thermal injury therapy are presented.

Emerging roles of microRNAs in septic cardiomyopathy

As one of the serious complications of sepsis, septic cardiomyopathy has gained more and more attention, because of its high morbidity and mortality. With the in-depth study of septic cardiomyopathy, several methods have been adopted clinically but have poor therapeutic effects due to failure to find precise therapeutic targets. In recent years, microRNAs have been found to be related to the pathogenesis, diagnosis, and treatment of septic cardiomyopathy via regulating immunity and programmed cell death. This paper reviews the role of microRNAs in septic cardiomyopathy, aiming to provide new targets for the diagnosis and treatment of septic cardiomyopathy.

Inflammatory mechanisms and intervention strategies for sepsis-induced myocardial dysfunction

Sepsis-induced myocardial dysfunction (SIMD) is the leading cause of death in patients with sepsis in the intensive care units. The main manifestations of SIMD are systolic and diastolic dysfunctions of the myocardium. Despite our initial understanding of the SIMD over the past three decades, the incidence and mortality of SIMD remain high. This may be attributed to the large degree of heterogeneity among the initiating factors, disease processes, and host states involved in SIMD. Previously, organ dysfunction caused by sepsis was thought to be an impairment brought about by an excessive inflammatory response. However, many recent studies have shown that SIMD is a consequence of a combination of factors shaped by the inflammatory responses between the pathogen and the host. In this article, we review the mechanisms of the inflammatory responses and potential novel therapeutic strategies in SIMD.

Diagnostic significance of microRNAs in sepsis

BACKGROUND

Sepsis is a life-threatening condition that induce tens of million death each year, yet early diagnosis remains a formidable challenge. Many studies have focused on the diagnostic accuracy of microRNAs (miRNAs) for sepsis in recent years, particularly miR-155-5p, miR-21, miR-223-3p, miR-146a, and miR-125a. Thus, we conducted this meta-analysis to explore if miRNAs may be used as a biomarker for sepsis detection.

METHODS

We searched PubMed, the Cochrane Central Register of Controlled Trials, EMBASE, and China National Knowledge Infrastructure through May 12, 2022. This meta-analysis was conducted using Meta-disc 1.4 and STATA 15.1 in a fixed/random-effect model.

RESULTS

The analysis included a total of 50 relevant studies. The overall performance of total miRNAs detection was: pooled sensitivity, 0.76 (95% confidence interval [CI], 0.75 to 0.77); pooled specificity, 0.77 (95%CI, 0.75 to 0.78); and area under the summary receiver operating characteristic curves value (SROC), 0.86. The subgroup analysis suggested that detection in miR-155-5p group had the highest area under the curve (AUC) of SROC among all miRNAs: pooled sensitivity, 0.71 (95%CI, 0.67 to 0.75); pooled specificity, 0.82 (95%CI, 0.76 to 0.86); and SROC, 0.85. MiR-21, miR-223-3p, miR-146a, and miR-125a had SROC values of 0.67, 0.78, 0.69, and 0.74, respectively. The specimen type was found to be a source of heterogeneity in the meta-regression study. The SROC of serum was higher than that of plasma (0.87 and 0.83, respectively).

CONCLUSIONS

Our meta-analysis revealed that miRNAs, specifically miR-155-5p, could be useful biomarkers for detecting sepsis. A clinical serum specimen is also indicated for diagnostic purposes.

REGULATORY ROLE OF NONCODING RNA IN SEPSIS AND SEPSIS-ASSOCIATED ORGAN DYSFUNCTION: AN UPDATED SYSTEMATIC REVIEW

ABSTRACT

Background: The exact molecular mechanisms underlying sepsis remain unclear. Accumulating evidence has shown that noncoding RNAs (ncRNAs) are involved in sepsis and sepsis-associated organ dysfunction (SAOD). Methods: We performed this updated systematic review focusing mainly on research conducted in the last 5 years regarding ncRNAs associated with sepsis and SAOD. The following medical subject headings were used in the PubMed database from October 1, 2016, to March 31, 2022: "microRNA," "long noncoding RNA," "circular RNA," "sepsis," and/or "septic shock." Studies investigating the role of ncRNAs in the pathogenesis of sepsis and as biomarkers or therapeutic targets in the disease were included. Data were extracted in terms of the role of ncRNAs in the pathogenesis of sepsis and their applicability for use as biomarkers or therapeutic targets in sepsis. The quality of the studies was assessed using a modified guideline from the Systematic Review Center for Laboratory Animal Experimentation. Results: A total of 537 original studies investigated the potential roles of ncRNAs in sepsis and SAOD. Experimental studies in the last 5 years confirmed that long ncRNAs have important regulatory roles in sepsis and SAOD. However, studies on circular RNAs and sepsis remain limited, and more studies should be conducted to elucidate this relationship. Among the included studies, the Systematic Review Center for Laboratory Animal Experimentation scores ranged from 3 to 7 (an average score of 3.78). Notably, 94 ncRNAs were evaluated as potential biomarkers for sepsis, and selective reporting of the sensitivity, specificity, and receiver operating characteristic curve was common. A total of 117 studies demonstrated the use of ncRNAs as potential therapeutic targets in sepsis and SAOD. At a molecular level, inflammation-related pathways, mitochondrial dysfunction, cell apoptosis, and/or oxidative stress were the most extensively studied. Conclusion: This review suggests that ncRNAs could be good biomarkers and therapeutic candidates for sepsis and SAOD. Prospective, large-scale, and multicenter cohort studies should be performed to evaluate specific ncRNAs as biomarkers and test the organ-specific delivery of these regulatory molecules when used as therapeutic targets.

Expression of MicroRNAs in Sepsis-Related Organ Dysfunction: A Systematic Review

Sepsis is a critical condition characterized by increased levels of pro-inflammatory cytokines and proliferating cells such as neutrophils and macrophages in response to microbial pathogens. Such processes lead to an abnormal inflammatory response and multi-organ failure. MicroRNAs (miRNA) are single-stranded non-coding RNAs with the function of gene regulation. This means that miRNAs are involved in multiple intracellular pathways and thus contribute to or inhibit inflammation. As a result, their variable expression in different tissues and organs may play a key role in regulating the pathophysiological events of sepsis. Thanks to this property, miRNAs may serve as potential diagnostic and prognostic biomarkers in such life-threatening events. In this narrative review, we collect the results of recent studies on the expression of miRNAs in heart, blood, lung, liver, brain, and kidney during sepsis and the molecular processes in which they are involved. In reviewing the literature, we find at least 122 miRNAs and signaling pathways involved in sepsis-related organ dysfunction. This may help clinicians to detect, prevent, and treat sepsis-related organ failures early, although further studies are needed to deepen the knowledge of their potential contribution.

Modes of action and diagnostic value of miRNAs in sepsis

Sepsis is a clinical syndrome defined as a dysregulated host response to infection resulting in life-threatening organ dysfunction. Sepsis is a major public health concern associated with one in five deaths worldwide. Sepsis is characterized by unbalanced inflammation and profound and sustained immunosuppression, increasing patient susceptibility to secondary infections and mortality. microRNAs (miRNAs) play a central role in the control of many biological processes, and deregulation of their expression has been linked to the development of oncological, cardiovascular, neurodegenerative and metabolic diseases. In this review, we discuss the role of miRNAs in sepsis pathophysiology. Overall, miRNAs are seen as promising biomarkers, and it has been proposed to develop miRNA-based therapies for sepsis. Yet, the picture is not so straightforward because of the versatile and dynamic features of miRNAs. Clearly, more research is needed to clarify the expression and role of miRNAs in sepsis, and to promote the use of miRNAs for sepsis management.

Non-Coding RNA Networks as Potential Novel Biomarker and Therapeutic Target for Sepsis and Sepsis-Related Multi-Organ Failure

According to “Sepsis-3” consensus, sepsis is a life-threatening clinical syndrome caused by a dysregulated inflammatory host response to infection. A rapid identification of sepsis is mandatory, as the extent of the organ damage triggered by both the pathogen itself and the host’s immune response could abruptly evolve to multiple organ failure and ultimately lead to the death of the patient. The most commonly used therapeutic strategy is to provide hemodynamic and global support to the patient and to rapidly initiate broad-spectrum empiric antibiotic therapy. To date, there is no gold standard diagnostic test that can ascertain the diagnosis of sepsis. Therefore, once sepsis is suspected, the presence of organ dysfunction can be assessed using the Sepsis-related Organ Failure Assessment (SOFA) score, although the diagnosis continues to depend primarily on clinical judgment. Clinicians can now rely on several serum biomarkers for the diagnosis of sepsis (e.g., procalcitonin), and promising new biomarkers have been evaluated, e.g., presepsin and adrenomedullin, although their clinical relevance in the hospital setting is still under discussion. Non-codingRNA, including long non-codingRNAs (lncRNAs), circularRNAs (circRNAs) and microRNAs (miRNAs), take part in a complex chain of events playing a pivotal role in several important regulatory processes in humans. In this narrative review we summarize and then analyze the function of circRNAs-miRNA-mRNA networks as putative novel biomarkers and therapeutic targets for sepsis, focusing only on data collected in clinical settings in humans.

Chrysophanol exerts a protective effect against sepsis-induced acute myocardial injury through modulating the microRNA-27b-3p/Peroxisomal proliferating-activated receptor gamma axis

Sepsis, a leading contributor to the death of inpatients, results in severe organ dysfunction as complications. The heart is one of the major organs attacked by sepsis, and the effective control of the inflammatory cascade reaction in sepsis is of great significance in alleviating sepsis-associated acute myocardial injury (S-AMI). Chrysophanol, a natural anthraquinone, has been discovered to carry anti-inflammatory effects. The aim of this paper is to probe the impact of Chrysophanol on S-AMI. An S-AMI model was engineered in rats via CLP. Pathological alterations in the myocardial tissues of rats were monitored. qRT-PCR, ELISA, and western blot measured the profiles of miR-27b-3p, Peroxisomal proliferating-activated receptor gamma (PPARG), inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-8), and inflammatory response proteins (NF-κB-p65, MAPK-p38, JNK1/2). Besides, miR-27b-3p mimics were transfected into cardiomyocytes, and the proliferation and apoptosis of cardiomyocytes were examined through MTT and flow cytometry. As evidenced by the experimental outcomes, chrysophanol suppressed sepsis-mediated acute myocardial injury and LPS-mediated apoptosis in myocardial cells and lessened the release of pro-inflammatory cytokines and inflammatory response proteins. Moreover, chrysophanol cramped miR-27b-3p expression and heightened PPARG expression. miR-27b-3p targeted PPARG and restrained its expression. On the other hand, the PPARG agonist (RGZ) partially eliminated the apoptosis and pro-inflammatory responses of myocardial cells elicited by LPS. Therefore, this study revealed that Chrysophanol guarded against sepsis-mediated acute myocardial injury through dampening inflammation and apoptosis via the miR-27b-3p-PPARG axis, adding to the references for treating sepsis-AMI.

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.

MicroRNA-381-3p signatures as a diagnostic marker in patients with sepsis and modulates sepsis-steered cardiac damage and inflammation by binding HMGB1

Immune response imbalance and cardiac dysfunction caused by sepsis are the main reasons for death in sepsis. This study aimed to confirm the expression and diagnostic possibility of microRNA-381-3p (miR-381-3p) and its mechanism in sepsis. Quantitative real-time PCR (qRT-PCR) and receiver operating characteristic (ROC) were used to reveal the levels and clinical significance of miR-381-3p. Pearson correlation was conducted to provide the correlations between miR-381-3p and several indexes of sepsis. The H9c2 cell models were constructed by lipopolysaccharide (LPS), and cecal ligation and puncture (CLP) was applied to establish the Sprague-Dawley (SD) rat models. Cell Counting Kit-8 (CCK-8) and flow cytometry were the methods to detect the cell viability and death rate of H9c2. Enzyme-linked immunosorbent assay (ELISA) was performed to evaluate the concentration of inflammatory cytokines. The target gene of miR-381-3p was validated via the luciferase report system. The low expression of miR-381-3p was found in the serum of patients with sepsis. The lessened miR-381-3p could be a marker in the discrimination of sepsis patients. Overexpression of miR-381-3p could repress the mRNA expression of HMGB1, inhibit the cell apoptosis and inflammatory response, and motivate the viability of sepsis cells. At the same time, enhanced miR-381-3p promoted the inhibition of inflammation and cardiac dysfunction in the rat model of sepsis. Collectively, reduced levels of serum miR-381-3p can be used as an index to detect sepsis patients. MiR-381-3p restored the inflammatory response and myocardial dysfunction caused by sepsis via HMGB1.

Clinical application of non-coding RNAs in sepsis

PURPOSE OF REVIEW

Studies indicating that non-coding RNAs (ncRNAs) play a regulatory role in sepsis are increasing rapidly. This present review summarizes recent publications on the role of microRNAs and long non-coding RNAs (lncRNAs) in sepsis.

RECENT FINDINGS

MicroRNAs (miRNAs) and lncRNAs are being identified as potential sepsis biomarkers and therapeutic targets. Experimental studies have examined the biological mechanisms that might underpin the regulatory role of these ncRNAs in sepsis.

SUMMARY

Clinical applications of miRNAs and lncRNAs in sepsis are on the horizon. These data could lead to the identification of novel treatments or indeed support the repurposing of existing drugs for sepsis. Validation of the findings from these preliminary studies and crucially integration of multiomics datasets will undoubtedly revolutionize the clinical management of sepsis.

Multi-Omics Analysis of Key microRNA-mRNA Metabolic Regulatory Networks in Skeletal Muscle of Obese Rabbits

microRNAs (miRNAs), small non-coding RNA with a length of about 22 nucleotides, are involved in the energy metabolism of skeletal muscle cells. However, their molecular mechanism of metabolism in rabbit skeletal muscle is still unclear. In this study, 16 rabbits, 8 in the control group (CON-G) and 8 in the experimental group (HFD-G), were chosen to construct an obese model induced by a high-fat diet fed from 35 to 70 days of age. Subsequently, 54 differentially expressed miRNAs, 248 differentially expressed mRNAs, and 108 differentially expressed proteins related to the metabolism of skeletal muscle were detected and analyzed with three sequencing techniques (small RNA sequencing, transcriptome sequencing, and tandem mass tab (TMT) protein technology). It was found that 12 miRNAs and 12 core genes (e.g., CRYL1, VDAC3 and APIP) were significantly different in skeletal muscle from rabbits in the two groups. The network analysis showed that seven miRNA-mRNA pairs were involved in metabolism. Importantly, two miRNAs (miR-92a-3p and miR-30a/c/d-5p) regulated three transcription factors (MYBL2, STAT1 and IKZF1) that may be essential for lipid metabolism. These results enhance our understanding of molecular mechanisms associated with rabbit skeletal muscle metabolism and provide a basis for future studies in the metabolic diseases of human obesity.

MicroRNAs and Sepsis-Induced Cardiac Dysfunction: A Systematic Review

Sepsis is a severe condition characterized by systemic inflammation. One of the most involved organs in sepsis is the heart. On the other hand, heart failure and dysfunction are some of the most leading causes of death in septic patients. miRNAs are short single-strand non-coding ribonucleic acids involved in the regulation of gene expression on a post-transcriptional phase, which means they are a part of the epigenetic process. Recently, researchers have found that miRNA expression in tissues and blood differs depending on different conditions. Because of this property, their use as serum sepsis biomarkers has also been explored. A narrative review is carried out to gather and summarize what is known about miRNAs' influence on cardiac dysfunction during sepsis. When reviewing the literature, we found at least 77 miRNAs involved in cardiac inflammation and dysfunction during sepsis. In the future, miRNAs may be used as early sepsis-induced cardiac dysfunction biomarkers or as new drug targets. This could help clinicians to early detect, prevent, and treat cardiac damage. The potential role of miRNAs as new diagnostic tools and therapeutic strategies worth deepening the complex network between non-coding RNA and biological pathways. Additional studies are needed to further investigate their role in sepsis-induced myocardium injury.