Biochemical and molecular study on serum miRNA-16a and miRNA- 451 as neonatal sepsis biomarkers

Diagnostic capacity of miRNAs in neonatal sepsis: a systematic review and meta-analysis

BACKGROUND

Neonatal sepsis is the third leading cause of mortality during the neonatal period, with manifestations atypical and obscure. But the gold standard-blood culture test, requiring 3-5 days, makes it difficult to unveil the final pathogen and leads to the increasing ratio of false-negative results. The empirical method is consulting traditional biomarkers, such as procalcitonin (PCT), C-reactive protein (CRP), and white blood cell count. However, they are not specific for neonate in diagnostic capacity, especially for infants within three days after delivery, so more novel biomarkers are urgently needed to assist diagnosing neonatal sepsis. microRNAs (miRNAs) have been widely studied in recent years for their diagnostic and prognostic values in different diseases and we conducted a meta-analysis of miRNAs on the topic that whether they are potentially novel biomarkers in early detection of neonatal sepsis.

OBJECTIVES

The purpose of the study was to assess whether circulating miRNAs could be used as potential biomarkers for neonatal sepsis, including early and late-onset neonatal sepsis, then calculate their overall accuracy (OA) via meta-analysis.

METHODS

PubMed, Cochrane Library, Embase, Web of Science, Scopus, and Ovid databases were retrieved; data cutoff for this analysis was 15 January 2023. Methodological quality assessment of included studies was performed through the Quality in Prognostic Studies tool. Corresponding 95% confidence interval (95%CI) was calculated to present miRNAs' diagnostic value including the pooled sensitivity (Sen), specificity (Spe), positive or negative likelihood ratios (PLR or NLR), diagnostic odds ratio (DOR), and area under the curve (AUC). Differences in OA between the septic group and non-septic group were compared using Chi-square test.

RESULTS

After identification, 16 records out of 11 selected articles were eligible for systematic review of miRNAs and four records for PCT; the case group for miRNAs included 945 neonatal sepsis cases; contrast group included 190 respiratory tract infections or pneumonia cases, 60 systemic inflammatory response syndrome (SIRS) cases and 559 healthy neonates. The pooled Sen, Spe, and DOR of miRNAs were 0.87 (95%CI 0.81-0.91), 0.79 (95%CI 0.71-0.85), and 24 (95%CI 12-50), respectively. The pooled Sen, Spe, and DOR of PCT were 0.92 (95%CI 0.83-0.96), 0.64 (95%CI 0.56-0.70), and 20 (95%CI, 7-56), respectively. The OA value of miRNAs was 80.38% and that of PCT was 77.36%, which were not statistically significant difference (p = .13) after the Chi-square test. In addition, no significant publication bias was indicated (p = .92).

CONCLUSIONS

Circulating miRNA levels could be applied as diagnostic biomarkers in neonatal sepsis.

MicroRNA Expression Profile in Patients Admitted to ICU as Novel and Reliable Approach for Diagnostic and Therapeutic Purposes

The ability to detect early metabolic changes in patients who have an increased mortality risk in the intensive care units (ICUs) could increase the likelihood of predicting recovery patterns and assist in disease management. Markers that can predict the disease progression of patients in the ICU might also be beneficial for improving their medical profile. Although biomarkers have been used in the ICU more frequently in recent years, the clinical use of most of them is limited. A wide range of biological processes are influenced by microRNAs (miRNAs) that modulate the translation and stability of specific mRNAs. Studies suggest that miRNAs may serve as a diagnostic and therapeutic biomarker in ICUs by profiling miRNA dysregulation in patient samples. To improve the predictive value of biomarkers for ICU patients, researchers have proposed both investigating miRNAs as novel biomarkers and combining them with other clinical biomarkers. Herein, we discuss recent approaches to the diagnosis and prognosis of patients admitted to an ICU, highlighting the use of miRNAs as novel and robust biomarkers for this purpose. In addition, we discuss emerging approaches to biomarker development and ways to improve the quality of biomarkers so that patients in ICU get the best outcomes possible.

Application of Advanced Molecular Methods to Study Early-Onset Neonatal Sepsis

Early-onset sepsis (EOS) is a global health issue, considered one of the primary causes of neonatal mortality. Diagnosis of EOS is challenging because its clinical signs are nonspecific, and blood culture, which is the current gold-standard diagnostic tool, has low sensitivity. Commonly used biomarkers for sepsis diagnosis, including C-reactive protein, procalcitonin, and interleukin-6, lack specificity for infection. Due to the disadvantages of blood culture and other common biomarkers, ongoing efforts are directed towards identifying innovative molecular approaches to diagnose neonates at risk of sepsis. This review aims to gather knowledge and recent research on these emerging molecular methods. PCR-based techniques and unrestricted techniques based on 16S rRNA sequencing and 16S-23S rRNA gene interspace region sequencing offer several advantages. Despite their potential, these approaches are not able to replace blood cultures due to several limitations; however, they may prove valuable as complementary tests in neonatal sepsis diagnosis. Several microRNAs have been evaluated and have been proposed as diagnostic biomarkers in EOS. T2 magnetic resonance and bioinformatic analysis have proposed potential biomarkers of neonatal sepsis, though further studies are essential to validate these findings.

Macrophage-derived exosomal miRNA-141 triggers endothelial cell pyroptosis by targeting NLRP3 to accelerate sepsis progression

Sepsis, critical condition marked by severe organ dysfunction from uncontrolled infection, involves the endothelium significantly. Macrophages, through paracrine actions, play a vital role in sepsis, but their mechanisms in sepsis pathogenesis remain elusive. Objective: We aimed to explore how macrophage-derived exosomes with low miR-141 expression promote pyroptosis in endothelial cells (ECs). Exosomes from THP-1 cell supernatant were isolated and characterized. The effects of miR-141 mimic/inhibitor on apoptosis, proliferation, and invasion of Human Umbilical Vein Endothelial Cells (HUVECs) were assessed using flow cytometry, CCK-8, and transwell assays. Key pyroptosis-related proteins, including caspase-1, IL-18, IL-1β, NLR Family Pyrin Domain Containing 3 (NLRP3), ASC, and cleaved-GSDMD, were analyzed via Western blot. The interaction between miR-141 and NLRP3 was studied using RNAhybrid v2.2 and dual-Luciferase reporter assays. The mRNA and protein level of NLRP3 after exosomal miR-141 inhibitor treatment was detected by qPCR and Western blot, respectively. Exosomes were successfully isolated. miR-141 mimic reduced cell death and pyroptosis-related protein expression in HUVECs, while the inhibitor had opposite effects, increasing cell death, and enhancing pyroptosis protein expression. Additionally, macrophage-derived exosomal miR-141 inhibitor increased cell death and pyroptosis-related proteins in HUVECs. miR-141 inhibits NLRP3 transcription. Macrophages facilitate sepsis progression by secreting miR-141 decreased exosomes to activate NLRP3-mediated pyroptosis in ECs, which could be a potentially valuable target of sepsis therapy.

Urinary microRNAs in sepsis function as a novel prognostic marker

Renal dysfunction is a common complication of sepsis. Early diagnosis and prompt treatment of sepsis with renal insufficiency are crucial for improving patient outcomes. Diagnostic markers can help identify patients at risk for sepsis and AKI, allowing for early intervention and potentially preventing the development of severe complications. The aim of the present study was to investigate the expression difference of urinary microRNAs (miRNAs/miRs) in elderly patients with sepsis and secondary renal insufficiency, and to evaluate their diagnostic value in these patients. In the present study, RNA was extracted from urine samples of elderly sepsis-related acute renal damage patients and the expression profiles of several miRNAs were analyzed. In order to evaluate the expression profile of several miRNAs, urine samples from elderly patients with acute renal damage brought on by sepsis were obtained. RNA extraction and sequencing were then performed on the samples. Furthermore, multiple bioinformatics methods were used to analyze miRNA profiles, including differential expression analysis, and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis of different miRNA target genes, to further explore miRNAs that are suitable for utilization as biomarkers. A total of four miRNAs, including hsa-miR-31-5p, hsa-miR-151a-3p, hsa-miR-142-5p and hsa-miR-16-5p, were identified as potential biological markers and were further confirmed in sepsis using reverse transcription-quantitative PCR. The results of the present study demonstrated that the four urinary miRNAs were differentially expressed and may serve as specific markers for prediction of secondary acute kidney injury in elderly patients with sepsis.

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.

MicroRNA as an Early Biomarker of Neonatal Sepsis

Sepsis is a major cause of lethality in neonatal intensive care units. Despite significant advances in neonatal care and growing scientific knowledge about the disease, 4 of every 10 infants born in developed countries and suffering from sepsis die or experience considerable disability, including substantial and permanent neurodevelopmental impairment. Pharmacological treatment strategies for neonatal sepsis remain limited and mainly based upon early initiation of antibiotics and supportive treatment. In this context, numerous clinical and serum-based markers have been evaluated for diagnosing sepsis and evaluating its severity and etiology. MicroRNAs (miRNAs) do not encode for proteins but regulate gene expression by inhibiting the translation or transcription of their target mRNAs. Recently, it was demonstrated in adult patients that miRNAs are released into the circulation and that the spectrum of circulating miRNAs is altered during various pathologic conditions, such as inflammation, infection, and sepsis. Here, we summarize current findings on the role of circulating miRNAs in the diagnosis and staging of neonatal sepsis. The conclusions point to substantial diagnostic potential, and several miRNAs have been validated independently by different teams, namely miR-16a, miR-16, miR-96-5p, miR-141, miR-181a, and miR-1184.

Diagnosis of neonatal sepsis: the past, present and future

Sepsis remains a significant cause of neonatal mortality and morbidity, especially in low- and middle-income countries. Neonatal sepsis presents with nonspecific signs and symptoms that necessitate tests to confirm the diagnosis. Early and accurate diagnosis of infection will improve clinical outcomes and decrease the overuse of antibiotics. Current diagnostic methods rely on conventional culture methods, which is time-consuming, and may delay critical therapeutic decisions. Nonculture-based techniques including molecular methods and mass spectrometry may overcome some of the limitations seen with culture-based techniques. Biomarkers including hematological indices, cell adhesion molecules, interleukins, and acute-phase reactants have been used for the diagnosis of neonatal sepsis. In this review, we examine past and current microbiological techniques, hematological indices, and inflammatory biomarkers that may aid sepsis diagnosis. The search for an ideal biomarker that has adequate diagnostic accuracy early in sepsis is still ongoing. We discuss promising strategies for the future that are being developed and tested that may help us diagnose sepsis early and improve clinical outcomes. IMPACT: Reviews the clinical relevance of currently available diagnostic tests for sepsis. Summarizes the diagnostic accuracy of novel biomarkers for neonatal sepsis. Outlines future strategies including the use of omics technology, personalized medicine, and point of care tests.