The predictive value of microRNA-21 for sepsis risk and its correlation with disease severity, systemic inflammation, and 28-day mortality in sepsis patients

MicroRNA as Sepsis Biomarkers: A Comprehensive Review

Sepsis, a life-threatening condition caused by the body's dysregulated response to infection, presents a significant challenge in clinical management. Timely and accurate diagnosis is paramount for initiating appropriate interventions and improving patient outcomes. In recent years, there has been growing interest in identifying biomarkers that can aid in the early detection and prognostication of sepsis. MicroRNAs (miRNAs) have emerged as potential biomarkers for sepsis due to their involvement in the regulation of gene expression and their stability in various biological fluids, including blood. MiRNAs are small non-coding RNA molecules that play crucial roles in post-transcriptional gene regulation by binding to target messenger RNAs (mRNAs), leading to mRNA degradation or translational repression. The diagnostic and prognostic potential of miRNAs in sepsis stems from their ability to serve as sensitive and specific biomarkers reflective of the underlying pathophysiological processes. Compared to traditional biomarkers such as C-reactive protein (CRP) and procalcitonin (PCT), miRNAs offer several advantages, including their early and sustained elevation during sepsis, as well as their stability in stored samples, making them attractive candidates for clinical use. However, despite their promise, the clinical translation of miRNAs as sepsis biomarkers faces several challenges. These include the need for standardized sample collection and processing methods, the identification of optimal miRNA panels or signatures for differentiating sepsis from other inflammatory conditions, and the validation of findings across diverse patient populations and clinical settings. In conclusion, miRNAs hold great promise as diagnostic and prognostic biomarkers for sepsis, offering insights into the underlying molecular mechanisms and potential therapeutic targets. However, further research is needed to overcome existing challenges and realize the full clinical utility of miRNAs in improving sepsis outcomes.

miRNA‑21 promotes the progression of acute liver failure via the KLF6/autophagy/IL‑23 signaling pathway

Acute liver failure (ALF) is a complex syndrome characterized by overactivation of innate immunity, and the recruitment and differentiation of immune cells at inflammatory sites. The present study aimed to explore the role of microRNA (miRNA/miR)‑21 and its potential mechanisms underlying inflammatory responses in ALF. Baseline serum miR‑21 was analyzed in patients with ALF and healthy controls. In addition, miR‑21 antagomir was injected via the tail vein into C57BL/6 mice, and lipopolysaccharide/D‑galactosamine (LPS/GalN) was injected into mice after 48 h. The expression levels of miR‑21, Krüppel‑like‑factor‑6 (KLF6), autophagy‑related proteins and interleukin (IL)‑23, and hepatic pathology were then assessed in the liver tissue. Furthermore, THP‑1‑derived macrophages were transfected with a miRNA negative control, miR‑21 inhibitor, miR‑21 mimics or KLF6 overexpression plasmid, followed by treatment with or without rapamycin, and the expression levels of miR‑21, KLF6, autophagy‑related proteins and IL‑23 were evaluated. The results revealed that baseline serum miR‑21 levels were significantly upregulated in patients with ALF. In addition, LPS/GalN‑induced ALF was attenuated in the antagomir‑21 mouse group. KLF6 was identified as a target of miR‑21‑5p with one putative seed match site identified by TargetScan. A subsequent luciferase activity assay demonstrated a direct interaction between miR‑21‑5p and the 3'‑UTR of KLF6 mRNA. Further experiments suggested that miR‑21 promoted the expression of IL‑23 via inhibiting KLF6, which regulated autophagy. In conclusion, in the present study, baseline serum miR‑21 levels were highly upregulated in patients with ALF, antagomir‑21 attenuated LPS/GalN‑induced ALF in a mouse model, and miR‑21 could promote the expression of IL‑23 via inhibiting KLF6.

Role of miRNA dysregulation in sepsis

Background

Sepsis is defined as a state of multisystem organ dysfunction secondary to a dysregulated host response to infection and causes millions of deaths worldwide annually. Novel ways to counteract this disease are needed and such tools may be heralded by a detailed understanding of its molecular pathogenesis. MiRNAs are small RNA molecules that target mRNAs to inhibit or degrade their translation and have important roles in several disease processes including sepsis.

Main body

The current review adopted a strategic approach to analyzing the widespread literature on the topic of miRNAs and sepsis. A pubmed search of “miRNA or microRNA or small RNA and sepsis not review” up to and including January 2021 led to 1140 manuscripts which were reviewed. Two hundred and thirty-three relevant papers were scrutinized for their content and important themes on the topic were identified and subsequently discussed, including an in-depth look at deregulated miRNAs in sepsis in peripheral blood, myeloid derived suppressor cells and extracellular vesicles.

Conclusion

Our analysis yielded important observations. Certain miRNAs, namely miR-150 and miR-146a, have consistent directional changes in peripheral blood of septic patients across numerous studies with strong data supporting a role in sepsis pathogenesis. Furthermore, a large body of literature show miRNA signatures of clinical relevance, and lastly, many miRNAs deregulated in sepsis are associated with the process of endothelial dysfunction. This review offers a widespread, up-to-date and detailed discussion of the role of miRNAs in sepsis and is meant to stimulate further work in the field due to the potential of these small miRNAs in prompt diagnostics, prognostication and therapeutic agency.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-022-00527-z.

Study on the expression of TRIM7 in peripheral blood mononuclear cells of patients with sepsis and its early diagnostic value

Background

The early diagnosis of sepsis is beneficial to put forward a reasonable clinical treatment plan as soon as possible. This study was to explore the expression of Tripartite Motif 7 (TRIM7) in peripheral blood mononuclear cells (PBMCs) of patients with sepsis and its diagnostic value.

Methods

This is a cross-sectional study. A total of 69 patients with infectious diseases were enrolled in the emergency room. They were divided into the sepsis group (34 cases) and the non-sepsis infection group (35 cases). There were 25 healthy subjects who were selected as the control group. The expression of TRIM7 in PBMCs was observed by immunofluorescence staining. The correlation between the expression of TRIM7 mRNA and acute physiology and chronic health evaluation II (APACHE II) score, sequential organ failure assessment (SOFA) score, white blood cell (WBC), C-reactive protein (CRP), procalcitonin (PCT), tumor necrosis factor (TNF)-α and interleukin (IL)-6 was discussed. The receiver operating characteristic (ROC) curve was utilized for evaluating the value of TRIM7 expression for the early diagnosis of sepsis.

Results

The fluorescence intensity representing the expression level of TRIM7 in PBMCs of patients in the sepsis group was the lowest among three groups. The TRIM7 mRNA expression in PBMCs of the sepsis group was greatly decreased in comparison with that of the non-sepsis infection group and control group (P < 0.05). Spearman correlation analysis indicated that TRIM7 mRNA expression was negatively correlated with APACHE II score, SOFA score, WBC, CRP, PCT, TNF-α and IL-6. ROC curve analysis revealed that the area under curve (AUC) of TRIM7 mRNA expression in PBMCs for the diagnosis of sepsis was 0.798, with a 95% confidence interval of 0.691- 0.905, a sensitivity of 73.5%, and a specificity of 77.1%.

Conclusion

The expression of TRIM7 in PBMCs of patients with sepsis is significantly down-regulated, which has certain clinical value for early diagnosis of sepsis.

Correlation of serum miR-127 level with severity and prognosis of sepsis

OBJECTIVE

To investigate the relationship of serum miR-127 level with the severity of sepsis patients and its predictive efficacy for prognosis.

METHODS

A total of 205 healthy individuals who underwent physical examination in Jingzhou Hospital Affiliated to Yangtze University and 205 patients with sepsis who were hospitalized in ICU from January 2021 to March 2022 were recruited in this study, and their serum miR-127 level were measured. The patients were divided into a high-miR-127 group (110 cases) and a low-miR-127 group (95 cases) based on the optimal cut-off value of miR-127 to assess the prognosis. The clinical data and 28-day survival of the two groups were analyzed. The patients were further divided into a death group (57 cases) and a survival group (148 cases) based on their 28-day survival. Factors associated with poor prognosis of sepsis were analyzed by Cox regression.

RESULTS

There were statistically significant differences in heart rate, body temperature, white blood cells (WBC), hemoglobin (Hb), procalcitonin (PCT), C-reactive protein (CRP), alanine aminotransferase (ALT), total bilirubin (TBIL), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), cardiac troponin I (cTnI), blood urea nitrogen (BUN), Prothrombin time (PT), serum creatinine (Scr), fibrinogen (FIB) and miR-127 between sepsis patients and healthy controls (P < 0.05). Compared to those in the low-miR-127 group, PCT, BUN, and SOFA scores in the high-miR-127 group were significantly higher (P < 0.05). The 28-day cumulative survival was lower in the high-miR-127 group (58.20%) than that in the low-miR-127 group (88.40%) (Log Rank χ² =25.598, P < 0.05). Those with high miR-127 still had a higher risk of poor prognosis compared to those with low miR-127 after correcting for SOFA score, APACHE II score and PCT (HR=3.292, 95% CI: 1.663-6.517, P < 0.05). The areas under the ROC curve (AUC) of serum miR-127, SOFA score, and APACHE II score for predicting prognosis of sepsis patients were 0.748 (0.674-0.823), 0.810 (0.742-0.878) and 0.864 (0.811-0.916), respectively.

CONCLUSION

Serum miR-127 is highly expressed in sepsis and related to the severity of sepsis. Those with high miR-127 level have a higher risk of poor prognosis.

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.

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 non-coding RNA growth arrest-specific 5 and its targets, microRNA-21 and microRNA-140, are potential biomarkers of allergic rhinitis

Objective

Long non‐coding RNA growth arrest‐specific 5 (lnc‐GAS5) and its targets (microRNA [miR]‐21 and miR‐140) are involved in the development and progression of allergic rhinitis (AR). However, the correlation of lnc‐GAS5 with miR‐21 and miR‐140 and their associations with disease risk, symptom severity, and Th1/Th2 cytokines in AR remain unclear. Thus, this study aimed to investigate this topic.

Methods

In total, 120 patients with AR and 60 controls were recruited. Nasal‐mucosa tissues were collected from all participants. Lnc‐GAS5, its targets (miR‐21 and miR‐140), interferon (IFN)‐γ, interleukin (IL)‐2, IL‐4, and IL‐10 were detected by reverse‐transcription quantitative polymerase chain reaction.

Results

Lnc‐GAS5 was elevated, while miR‐21 and miR‐140 was downregulated in AR patients than in controls (p < 0.001). In AR patients, lnc‐GAS5 was negatively correlated with miR‐21 (p < 0.001), miR‐140 (p < 0.001), IFN‐γ (p = 0.019), and IL‐2 (p = 0.039) and positively correlated with IL‐4 (p = 0.004) and IL‐10 (p < 0.001), individual nasal symptom scores (INSSs) for itching, sneezing, and congestion (p < 0.05), and total nasal symptom score (TNSS) (p < 0.001). Moreover, miR‐21 and miR‐140 were negatively correlated with some INSSs, total TNSS score, and IL‐10 and positively correlated with IFN‐γ and IL‐2 (p < 0.05).

Conclusion

Lnc‐GAS5 is negatively correlated with that of its targets (miR‐21 and miR‐140) in AR; meanwhile, lnc‐GAS5, miR‐21, and miR‐140 are correlated with disease risk, symptom severity, and Th1/Th2 imbalance in AR, suggesting the potential of these biomarkers in the development and progression of AR.

Diagnostic Value of miR-103 in Patients with Sepsis and Noninfectious SIRS and Its Regulatory Role in LPS-Induced Inflammatory Response by Targeting TLR4

Background

Sepsis is a life-threatening condition and a systemic inflammatory response syndrome (SIRS) driven by infection. This study aimed at investigating the expression of microRNA-103 (miR-103) in sepsis patients, evaluating its diagnostic value, and exploring the regulatory effect of miR-103 on LPS-induced inflammation in monocytes.

Methods

Expression of miR-103 was measured using quantitative real-time PCR. A receiver operating characteristics curve was plotted to evaluate the diagnostic vale of miR-103. Serum and cell supernatant levels of proinflammatory cytokines were analyzed using ELISA. The interaction between miR-103 and Toll-like receptors 4 (TLR4) was analyzed using luciferase reporter assay. The effect of miR-103 on inflammation was examined in LPS-treated monocytes.

Results

Serum expression of miR-103 was decreased in noninfectious SIRS and sepsis patients compared with healthy controls, and the lowest expression value was observed in sepsis patients (all P < 0.05). Serum levels of miR-103 have considerable diagnostic accuracy in distinguishing sepsis patients from SIRS patients and healthy controls. A negative correlation was found between miR-103 and inflammatory responses in sepsis patients. TLR4 was demonstrated to be a direct target of miR-103 and was negatively regulated by miR-103 in monocytes. The promoted inflammatory responses by LPS in monocytes were reversed by the overexpression of miR-103.

Conclusion

All the data revealed that serum decreased miR-103 in sepsis patients serves as a promising noninvasive diagnostic biomarker and may be involved in the pathogenesis of sepsis by regulating inflammatory responses via targeting TLR4.

Clinical significance of miR-19b-3p in patients with sepsis and its regulatory role in the LPS-induced inflammatory response

Background

MicroRNAs (miRNAs) play important roles in the development and progression of sepsis. This study investigated the clinical value of miR-19b-3p in sepsis patients, and explored its role in regulating inflammatory responses in HUVECs cells.

Methods

103 patients with sepsis and 98 healthy individuals were recruited. qRT-PCR was used for the measurement of miR-19b-3p level. Cell viability was evaluated using CCK-8. The protein levels of TNF-α and IL-6 were measured using ELISA. Receiver operating characteristic (ROC) curve and logistic regression analysis were constructed to evaluate the diagnostic and prognostic values of miR-19b-3p in sepsis patients.

Results

MiR-19b-3p level was significantly reduced in the serum from patients with sepsis compared with healthy controls (P < 0.001). Sepsis patients in the survival group had significantly high miR-19b-3p levels compared with the non-survival group (P < 0.001). MiR-19b-3p was of a good value in predicting sepsis risk, and was an independent prognostic factor for 28-day survival in sepsis patients (OR = 3.226, 95% CI 1.076–9.670, P = 0.037). MiR-19b-3p level was negatively associated with serum levels of IL-6 (r = − 0.852, P < 0.001) and TNF-α (r = − 0.761, P < 0.001). Overexpression of miR-19b-3p alleviated LPS-induced inflammatory response of HUVECs, which was reflected by the decrease of the levels of IL-6 and TNF-α induced by LPS treatment (P < 0.001).

Conclusion

MiR-19b-3p might be a potential biomarker for the early diagnosis and prognosis of sepsis patients. Overexpression of miR-19b-3p alleviated sepsis-induced inflammatory responses.

The predictive value of microRNA-21 for sepsis risk and its correlation with disease severity, systemic inflammation, and 28-day mortality in sepsis patients

Background

This study aimed to investigate the value of microRNA (miR)‐21 for predicting sepsis risk and its correlation with inflammation, disease severity as well as 28‐day mortality in sepsis patients.

Methods

Totally, 219 sepsis patients and 219 healthy controls (HCs) were recruited. Plasma samples were obtained from sepsis patients within 24 hours after admission and from HCs at the enrollment to detect miR‐21 expressions by real‐time quantitative polymerase chain reaction. Besides, the clinical characteristics of sepsis patients were recorded and the 28‐day mortality of sepsis patients was evaluated.

Results

MiR‐21 expression was decreased in sepsis patients compared with HCs, and further receiver operating characteristic (ROC) curve analysis revealed that miR‐21 was of a good value in predicting sepsis risk (area under the curve [AUC]: 0.801, 95% CI: 0.758‐0.844). Besides, miR‐21 expression was negatively associated with acute pathologic and chronic health evaluation II (APACHE II) and sequential organ failure assessment (SOFA) score in sepsis patients. Furthermore, miR‐21 expression was negatively correlated with serum creatinine, C‐reactive protein, tumor necrosis factor‐α, interleukin (IL)‐1β, IL‐6, and IL‐17, while positively correlated with albumin in sepsis patients. However, there was no correlation of miR‐21 expression with white blood cell, smoke, or comorbidities in sepsis patients. Additionally, ROC curve analysis displayed that miR‐21 exhibited a poor predictive value for 28‐day mortality risk in sepsis patients (AUC: 0.588, 95% CI: 0.505‐0.672).

Conclusion

MiR‐21 might serve as a potential biomarker for the development and progression of sepsis, while not for prognosis prediction in sepsis patients.