miR‑214 ameliorates sepsis‑induced acute kidney injury via PTEN/AKT/mTOR‑regulated autophagy

miR-16-5p aggravates sepsis-associated acute kidney injury by inducing apoptosis

Sepsis-associated acute kidney injury (S-AKI) is a common disease in pediatric intensive care units (ICU) with high morbidity and mortality. The newly discovered results indicate that microRNAs (miRNAs) play an important role in the diagnosis and treatment of S-AKI and can be used as markers for early diagnosis. In this study, the expression level of miR-16-5p was found to be significantly upregulated about 20-fold in S-AKI patients, and it also increased by 1.9 times in the renal tissue of S-AKI mice. Receiver operating characteristic (ROC) curve analysis showed that miR-16-5p had the highest predictive accuracy in the diagnosis of S-AKI (AUC = 0.9188). In vitro, the expression level of miR-16-5p in HK-2 cells treated with 10 μg/mL lipopolysaccharide (LPS) increased by more than 2 times. In addition, LPS-exposed renal tissue and HK-2 cells lead to upregulation of inflammatory cytokines IL-6, IL-1β, TNF-a, and kidney damage molecules kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL). However, inhibition of miR-16-5p significantly mitigated LPS expose-mediated kidney injury and inflammation. Furthermore, LPS-exposed HK-2 cells increased more than 1.7-fold the expression levels of Bax and caspase-3, decreased 3.2-fold the expression level of B-cell lymphoma-2 (Bcl-2), and significantly promoted the occurrence of apoptosis. MiR-16-5p mimic further increased LPS-induced apoptosis in HK-2 cells. Nevertheless, inhibition of miR-16-5p significantly attenuated this effect. In summary, up-regulation of miR-16-5p expression can significantly aggravate renal injury and apoptosis in S-AKI, which also proves that miR-16-5p can be used as a potential biomarker to promote early identification of S-AKI.

Research progress on miR-124-3p in the field of kidney disease

MicroRNAs (miRNAs) are 18-25 nucleotides long, single-stranded, non-coding RNA molecules that regulate gene expression. They play a crucial role in maintaining normal cellular functions and homeostasis in organisms. Studies have shown that miR-124-3p is highly expressed in brain tissue and plays a significant role in nervous system development. It is also described as a tumor suppressor, regulating biological processes like cancer cell proliferation, apoptosis, migration, and invasion by controlling multiple downstream target genes. miR-124-3p has been found to be involved in the progression of various kidney diseases, including diabetic kidney disease, calcium oxalate kidney stones, acute kidney injury, lupus nephritis, and renal interstitial fibrosis. It mediates these processes through mechanisms like oxidative stress, inflammation, autophagy, and ferroptosis. To lay the foundation for future therapeutic strategies, this research group reviewed recent studies on the functional roles of miR-124-3p in renal diseases and the regulation of its downstream target genes. Additionally, the feasibility, limitations, and potential application of miR-124-3p as a diagnostic biomarker and therapeutic target were thoroughly investigated.

Corylin alleviated sepsis-associated cardiac dysfunction via attenuating inflammation through downregulation of microRNA-214-5p

Background

Corylin, a natural flavonoid, is isolated from the fruit of Psoralea corylifolia L. Nevertheless, the effect of corylin on sepsis-associated cardiac dysfunction is still unclear. The purpose of this study is to determine the role and mechanism of corylin in sepsis related cardiac dysfunction.

Methods

Experiments were carried out on mice with lipopolysaccharide (LPS) or sepsis induced by cecal ligation and puncture (CLP) or myocardial cell sepsis induced by LPS.

Results

Administration of corylin improved cardiac dysfunction induced by LPS or CLP in mice. Corylin inhibited the increases of interleukin-1 (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α in the heart of mice with LPS or CLP. LPS elevated the levels of IL-1β, IL-6 and TNF-α in cardiomyocytes, which were inhibited by corylin treatment. Corylin attenuated the increases of microRNA (miRNA)-214-5p in the heart of mice with LPS, CLP, LPS-treated NRCMs, H9c2 and AC16 cells. Administration of miRNA-214-5p agomiR reversed the improving effects of corylin on the damaged cardiac function and the increases of IL-1β, IL-6 and TNF-α in mice treated with LPS.

Conclusion

These outcomes indicated that corylin improved sepsis-associated cardiac dysfunction by inhibiting inflammation. And corylin inhibited inflammation of sepsis by decreasing miRNA-214-5p. Downregulation of miRNA-214-5p improved sepsis-associated cardiac dysfunction and inhibited inflammatory factors.

miRNA-29-3p targets PTEN to regulate follicular development through the PI3K/Akt/mTOR signaling pathway

Granulosa cells play a pivotal role in growth, development and ovulation of ovarian follicle. Simultaneously, autophagy and apoptosis processes are crucial determinants in the destiny of granulosa cells. Within this context, miR-29-3p, known to regulate a broad spectrum of biological processes and critical for tumor detection, prognosis, and treatment, is poised to clarify its roles in both autophagy and apoptosis. To enhance the understanding of the influence of miR-29-3p on follicular development, our study primarily delved into the realms autophagy and apoptosis. We employed a well-established chicken follicular atrophy model achieved through subcutaneous injection of tamoxifen (TMX) into hens. qPCR analysis revealed a significant decrease in the expression of miR-29-3p within the atrophic follicles. In our in vitro experiments with cultured chicken primary granulosa cells, miR-29-3p emerged as a novel microRNA capable of impeding autophagy and apoptosis when transfected with miR-29-3p mimics and inhibitors. Results from luciferase reporter assays corroborated that PTEN is a legitimate target of miR-29-3p. Unlike miR-29-3p, PTEN appeared to foster autophagy and apoptosis in chicken granulosa cells. Moreover, our findings uncovered that miR-29-3p facilitates the phosphorylation of Akt and mTOR proteins by targeting PTEN in chicken granulosa cells. In conclusion, the findings of this study suggest that miR-29-3p, through its targeting of PTEN via the Akt/mTOR signaling pathway, exerts inhibitory effects on autophagy and apoptosis. These effects may hold significant importance in the context of follicular development.

METTL3-mediated N6-methyladenosine modification stimulates mitochondrial damage and ferroptosis of kidney tubular epithelial cells following acute kidney injury by modulating the stabilization of MDM2-p53-LMNB1 axis

N6-methyladenosine (m6A) and MELLT3 assume a role in the development of acute kidney injury (AKI). However, their mechanism in AKI remains under-explored. On this basis, this study explored the mechanism of MELLT3 in mitochondrial damage and ferroptosis of kidney tubular epithelial cells after AKI. HK-2 cells were induced by lipopolysaccharide (LPS) to simulate AKI, followed by gain and loss of function of genes, detection of mitochondrial damage and ferroptosis indicators, and analysis of gene interactions. An AKI mouse model was developed using the cecal ligation and puncture (CLP) method to investigate the effect of METTL3 knockdown on kidney injury. MDM2 and LMNB1 were upregulated and p53 was downregulated in LPS-treated HK-2 cells. Mechanistically, the E3 ubiquitin ligase MDM2 increased p53 ubiquitination to activate LMNB1. METTL3 knockdown decreased m6A methylation of MDM2, thus diminishing YTHDF1-mediated MDM2 mRNA stability and translation in LPS-treated HK-2 cells. Knockdown of LMNB1, MDM2, or METTL3 reduced NO, MDA, iron ion, and ROS levels as well as mitochondrial damage and raised SOD, GSH, XCT, GPX4, FPN1, and TFR1 levels in LPS-treated HK-2 cells. The in vivo results showed that METTL3 knockdown reduced renal injury and ferroptosis in CLP mice. METTL3 knockdown prevents mitochondrial damage and ferroptosis of kidney tubular epithelial cells after AKI via the MDM2-p53-LMNB1 axis.

MicroRNAs as Biomarkers and Therapeutic Targets for Acute Kidney Injury

Acute kidney injury (AKI) is a clinical syndrome where a rapid decrease in kidney function and/or urine output is observed, which may result in the imbalance of water, electrolytes and acid base. It is associated with poor prognosis and prolonged hospitalization. Therefore, an early diagnosis and treatment to avoid the severe AKI stage are important. While several biomarkers, such as urinary L-FABP and NGAL, can be clinically useful, there is still no gold standard for the early detection of AKI and there are limited therapeutic options against AKI. miRNAs are non-coding and single-stranded RNAs that silence their target genes in the post-transcriptional process and are involved in a wide range of biological processes. Recent accumulated evidence has revealed that miRNAs may be potential biomarkers and therapeutic targets for AKI. In this review article, we summarize the current knowledge about miRNAs as promising biomarkers and potential therapeutic targets for AKI, as well as the challenges in their clinical use.

Roles of noncoding RNAs in septic acute kidney injury

Septic acute kidney injury (SAKI) is one of the most common and life-threatening complications of sepsis. Patients with SAKI have increased mortality. However, the underlying pathogenesis is unclear, and the treatment targeting SAKI is unsatisfactory. Thus, identifying optimal biomarkers for SAKI diagnosis and treatment is an urgent requisite. Accumulating evidence indicates that noncoding RNAs (ncRNAs) are involved in the occurrence and progression of SAKI. In the present review, we summarized the studies of ncRNAs in SAKI, including microRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs). The ncRNAs are divided into protective and damage factors according to their role in SAKI, and their expression patterns, functions, and molecular mechanisms were elaborated. Next, we proposed that ncRNAs have the potential to be diagnostic and prognostic biomarkers for SAKI and as new therapeutic targets. This review aimed to provide a comprehensive overview of ncRNAs in SKAI and explored the clinical value of ncRNAs as ideal biomarkers of SAKI.

miR-506-3p induces autophagy of renal tubular epithelial cells in sepsis through targeting PI3K pathway

OBJECTIVE

To explore the effect of micro ribonucleic acid (miR)-506-3p on autophagy of renal tubular epithelial cells in sepsis and its mechanism.

METHODS

It was found through bioinformatics analysis that phosphatidylinositol 3-kinase catalytic subunit alpha (PIK3CA) was expressed at a low level in sepsis, and miR-506-3p had a targeted regulatory effect on PIK3CA. 40 8-week-old male C57BL/6 mice were randomly divided into control miR-506-3p NC group, control miR-506-3p OE group, sepsis miR-506-3p NC group, sepsis miR-506-3p OE group and sepsis miR-506-3p KD group. The pathological changes in kidney tissues of mice in each group were observed by hematoxylin-eosin (HE) staining and TUNEL staining, and mitochondria and autophagosomes were visualized by transmission electron microscopy. CCK8 assay was performed to detect the effect of miR-506-3p on the proliferation capacity of renal tubular epithelial cells. The changes in the expression of PI3K-Akt pathway proteins, mTOR and autophagy proteins were tested by Western blotting.

RESULTS

The injury and apoptotic positive cells were suppressed and decreased in miR-506-3p OE mice vs. NC group. miR-506-3p could increase the number of mitochondria and autophagosomes in kidney tissues. After introduction of exogenous miR-506-3p OE into renal tubular epithelial cells, the expressions of PI3K pathway proteins were significantly inhibited, while the expressions of autophagy proteins were significantly enhanced. After 740Y-P was added, the expressions of associated proteins had no significant changes in each group.

CONCLUSION

Overexpression of miR-506-3p can enhance the autophagy of renal tubular epithelial cells in sepsis through inhibiting the PI3K signaling pathway.

Guizhi Fuling Wan inhibits autophagy of granulosa cells in polycystic ovary syndrome mice via H19/miR-29b-3p

OBJECTIVE

To investigate the potential molecular mechanism of traditional Chinese medicine Guizhi Fuling Wan (GZFLW) inhibiting granulosa cells (GCs) autophagy in polycystic ovary syndrome (PCOS).

METHODS

Control GCs and model GCs were cultured and treated with blank serum or GZFLW-containing serum. The levels of H19 and miR-29b-3p in GCs were detected using qRT-PCR, target genes of miR-29b-3p were identified using luciferase assay. The protein expressions of Phosphatase and tensin homolog (PTEN), Matrix Metalloproteinase (MMP)-2, and Bax were measured using western blot. The level of autophagy was detected via MDC staining, the degree of autophagosomes and autophagic polymers was observed using dual fluorescence-tagged mRFP-eGFP-LC3.

RESULTS

GZFLW intervention reduced the expression of autophagy-related proteins PTEN, MMP-2 and Bax, by upregulating the expression of miR-29b-3p and downregulated the expression of H19 (p < .05 or p < .01). The number of autophagosomes and autophagy polymers was significantly decreased by GZFLW treatment. However, the inhibition of miR-29b-3p and overexpression of H19 induced a significant increase in the number of autophagosomes and autophagic polymers, which attenuated the inhibitory effect of GZFLW on autophagy (p < .05 or p < .01). In addition, inhibition of miR-29b-3p or overexpression of H19 can attenuate the effect of GZFLW on the expression of PTEN, MMP-2 and Bax proteins (p < .05 or p < .01).

CONCLUSION

Our study found that GZFLW inhibits autophagy in PCOS GCs via H19/miR-29b-3p pathway.

Epigenetic dysregulation of autophagy in sepsis-induced acute kidney injury: the underlying mechanisms for renoprotection

Sepsis-induced acute kidney injury (SI-AKI), a common critically ill, represents one of the leading causes of global death. Emerging evidence reveals autophagy as a pivotal modulator of SI-AKI. Autophagy affects the cellular processes of renal lesions, including cell death, inflammation, and immune responses. Herein, we conducted a systematic and comprehensive review on the topic of the proposed roles of autophagy in SI-AKI. Forty-one relevant studies were finally included and further summarized and analyzed. This review revealed that a majority of included studies (24/41, 58.5%) showed an elevation of the autophagy level during SI-AKI, while 22% and 19.5% of the included studies reported an inhibition and an elevation at the early stage but a declination of renal autophagy in SI-AKI, respectively. Multiple intracellular signaling molecules and pathways targeting autophagy (e.g. mTOR, non-coding RNA, Sirtuins family, mitophagy, AMPK, ROS, NF-Kb, and Parkin) involved in the process of SI-AKI, exerting multiple biological effects on the kidney. Multiple treatment modalities (e.g. small molecule inhibitors, temsirolimus, rapamycin, polydatin, ascorbate, recombinant human erythropoietin, stem cells, Procyanidin B2, and dexmedetomidine) have been found to improve renal function, which may be attributed to the elevation of the autophagy level in SI-AKI. Though the exact roles of autophagy in SI-AKI have not been well elucidated, it may be implicated in preventing SI-AKI through various molecular pathways. Targeting the autophagy-associated proteins and pathways may hint towards a new prospective in the treatment of critically ill patients with SI-AKI, but more preclinical studies are still warranted to validate this hypothesis.

Role of microRNAs in programmed cell death in renal diseases: A review

MicroRNAs (miRNAs) regulate gene expression involving kidney morphogenesis and cell proliferation, apoptosis, differentiation, migration, invasion, immune evasion, and extracellular matrix remodeling. Programmed cell death (PCD) is mediated and regulated by specific genes and a wealth of miRNAs, which participate in various pathological processes. Dysregulation of miRNAs can disrupt renal development and induce the onset and progression of various renal diseases. An in-depth understanding of how miRNAs regulate renal development and diseases is indispensable to comprehending how they can be used in new diagnostic and therapeutic approaches. However, the mechanisms are still insufficiently investigated. Hence, we review the current roles of miRNA-related signaling pathways and recent advances in PCD research and aim to display the potential crosstalk between miRNAs and PCD. The prospects of miRNAs as novel biomarkers and therapeutic targets are also described, which might provide some novel ideas for further studies.

Identification of potential biomarkers and pathways for sepsis using RNA sequencing technology and bioinformatic analysis

Long non-coding RNAs (lncRNAs) has been proven by many to play a crucial part in the process of sepsis. To obtain a better understanding of sepsis, the molecular biomarkers associated with it, and its possible pathogenesis, we obtained data from RNA-sequencing analysis using serum from three sepsis patients and three healthy controls (HCs). Using edgeR (one of the Bioconductor software package), we identified 1118 differentially expressed mRNAs (DEmRNAs) and 1394 differentially expressed long noncoding RNAs (DElncRNAs) between sepsis patients and HCs. We identified the biological functions of these disordered genes using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway analyses. The GO analysis showed that the homophilic cell adhesion via plasma membrane adhesion molecules was the most significantly enriched category. The KEGG signaling pathway analysis indicated that the differentially expressed genes (DEGs) were most significantly enriched in retrograde endocannabinoid signaling. Using STRING, a protein-protein interaction network was also created, and Cytohubba was used to determine the top 10 hub genes. To examine the relationship between the hub genes and sepsis, we examined three datasets relevant to sepsis that were found in the gene expression omnibus (GEO) database. PTEN and HIST2H2BE were recognized as hub gene in both GSE4607, GSE26378, and GSE9692 datasets. The receiver operating characteristic (ROC) curves indicate that PTEN and HIST2H2BE have good diagnostic value for sepsis. In conclusion, this two hub genes may be biomarkers for the early diagnosis of sepsis, our findings should deepen our understanding of the pathogenesis of sepsis.

Downregulation of miR-527 alleviates sepsis-induced acute kidney injury via targeting Beclin1

BACKGROUND

Sepsis-induced acute kidney injury (AKI) is known to result from the inflammatory responses. MiRNAs participate in the development of sepsis-induced AKI. Nevertheless, the function of miR-527 in sepsis-induced AKI remains unclear.

METHODS

Cell viability was evaluated by CCK8 assay, and TUNEL staining was applied to assess cell apoptosis. Pro-inflammatory cytokine (TNF-α, IL-6 and IL-1β) levels were evaluated by ELISA. Meanwhile, the relation among miR-527 and Beclin1 was detected by dual luciferase report assay. Western blot and RT-qPCR were used to examine the protein and mRNA levels, respectively. Furthermore, an in vivo model was constructed to assess the function of miR-527 in sepsis-induced AKI.

RESULTS

MiR-527 downregulation significantly alleviated the symptoms of sepsis-induced AKI in mice. MiR-527 level in HK-2 cells was significantly upregulated by LPS, and downregulation of miR-527 notably reversed LPS-induced inhibition of HK-2 cell viability by inhibiting apoptosis. In addition, LPS greatly increased TNF-α, IL-6 and IL-1β levels in supernatant of HK-2 cells, while miR-527 inhibitor partially restored this phenomenon. Meanwhile, Beclin1 was found to be the downstream mRNA of miR-527, and miR-527 inhibitor notably upregulated the level of LC3. MiR-527 downregulation reversed LPS-induced HK-2 cell injury through suppression of TGF-β pathway.

CONCLUSION

Downregulation of miR-527 alleviated sepsis-induced AKI via targeting Beclin1. Thus, miR-527 might act as a vital mediator in sepsis-induced AKI.

Roles of circular RNAs in regulating the development of glioma

BACKGROUND

Glioma is the most common malignant tumor in the central nervous system. In patients with glioma, the prognosis is poor and median survival is only 12-15 months. With the recent development of sequencing technology, important roles of noncoding RNAs are being discovered in cells, especially those of circular RNAs (circRNAs). Because circRNAs are stable, abundant, and highly conserved, they are regarded as novel biomarkers in the early diagnosis and prognosis of diseases.

PURPOSE

In this review, roles and mechanisms of circRNAs in the development of glioma are summarized.

METHODS

This paper collects and reviews relevant PubMed literature.

CONCLUSION

Several classes of circRNAs are highly expressed in glioma and are associated with malignant biological behaviors of gliomas, including proliferation, migration, invasion, apoptosis, angiogenesis, and drug resistance. Further studies are needed to clarify the roles of circRNAs in glioma and to determine whether it is possible to increase therapeutic effects on tumors through circRNA intervention.

Probiotic Potential of the Marine Isolate Enterococcus faecium EA9 and In Vivo Evaluation of Its Antisepsis Action in Rats

This study aims to obtain a novel probiotic strain adapted to marine habitats and to assess its antisepsis properties using a cecal ligation and puncture (CLP) model in rodents. The marine Enterococcus faecium EA9 was isolated from marine shrimp samples and evaluated for probiotic potential after phenotypical and molecular identification. In septic animals, hepatic and renal tissues were histologically and biochemically evaluated for inflammation and oxidative stress following the probiotic treatment. Moreover, gene expressions of multiple signaling cascades were determined using RT-PCR. EA9 was identified and genotyped as Enterococcus faecium with a 99.88% identity. EA9 did not exhibit any signs of hemolysis and survived at low pH and elevated concentrations of bile salts. Moreover, EA9 isolate had antibacterial activity against different pathogenic bacteria and could thrive in 6.5% NaCl. Septic animals treated with EA9 had improved liver and kidney functions, lower inflammatory and lipid peroxidation biomarkers, and enhanced antioxidant enzymes. The CLP-induced necrotic histological changes and altered gene expressions of IL-10, IL-1β, INF-γ, COX-2, SOD-1, SOD-2, HO-1, AKT, mTOR, iNOS, and STAT-3 were abolished by the EA9 probiotic in septic animals. The isolate Enterococcus faecium EA9 represents a promising marine probiotic. The in vivo antisepsis testing of EA9 highlighted its potential and effective therapeutic approach.

MicroRNAs in septic acute kidney injury

Sepsis is a potentially fatal complication of burns and trauma that can cause acute kidney injury (AKI) with substantial morbidity and mortality, but this disease is poorly understood. Despite medical advances, effective therapeutic regimens for septic AKI remain uncommon. MicroRNAs (miRNAs) are endogenous non-coding RNAs that influence the translation of target messenger RNAs in a variety of biological processes. Emerging evidence has shown that miRNAs are intimately associated with septic AKI. The goal of this review was to summarize recent advances in the profound understanding of the functional role of miRNAs in septic AKI, as well as to provide new insights into miRNAs as feasible biomarkers and therapeutic targets for septic AKI.

The Sphingosine Kinase 2 Inhibitor Opaganib Protects Against Acute Kidney Injury in Mice

Introduction

Acute kidney injury (AKI) is a common multifactorial adverse effect of surgery, circulatory obstruction, sepsis or drug/toxin exposure that often results in morbidity and mortality. Sphingolipid metabolism is a critical regulator of cell survival and pathologic inflammation processes involved in AKI. Opaganib (also known as ABC294640) is a first-in-class experimental drug targeting sphingolipid metabolism that reduces the production and activity of inflammatory cytokines and, therefore, may be effective to prevent and treat AKI.

Methods

Murine models of AKI were used to assess the in vivo efficacy of opaganib including ischemia-reperfusion (IR) injury induced by either transient bilateral occlusion of renal blood flow (a moderate model) or nephrectomy followed immediately by occlusion of the contralateral kidney (a severe model) and lipopolysaccharide (LPS)-induced sepsis. Biochemical and histologic assays were used to quantify the effects of oral opaganib treatment on renal damage in these models.

Results

Opaganib suppressed the elevations of creatinine and blood urea nitrogen (BUN), as well as granulocyte infiltration into the kidneys, of mice that experienced moderate IR from transient bilateral ligation. Opaganib also markedly decreased these parameters and completely prevented mortality in the severe renal IR model. Additionally, opaganib blunted the elevations of BUN, creatinine and inflammatory cytokines following exposure to LPS.

Conclusion

The data support the hypotheses that sphingolipid metabolism is a key mediator of renal inflammatory damage following IR injury and sepsis, and that this can be suppressed by opaganib. Because opaganib has already undergone clinical testing in other diseases (cancer and Covid-19), the present studies support conducting clinical trials with this drug with surgical or septic patients at risk for AKI.

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.

MicroRNAs in kidney injury and disease

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression by degrading or repressing the translation of their target messenger RNAs. As miRNAs are critical regulators of cellular homeostasis, their dysregulation is a crucial component of cell and organ injury. A substantial body of evidence indicates that miRNAs are involved in the pathophysiology of acute kidney injury (AKI), chronic kidney disease and allograft damage. Different subsets of miRNAs are dysregulated during AKI, chronic kidney disease and allograft rejection, which could reflect differences in the physiopathology of these conditions. miRNAs that have been investigated in AKI include miR-21, which has an anti-apoptotic role, and miR-214 and miR-668, which regulate mitochondrial dynamics. Various miRNAs are downregulated in diabetic kidney disease, including the miR-30 family and miR-146a, which protect against inflammation and fibrosis. Other miRNAs such as miR-193 and miR-92a induce podocyte dedifferentiation in glomerulonephritis. In transplantation, miRNAs have been implicated in allograft rejection and injury. Further work is needed to identify and validate miRNAs as biomarkers of graft function and of kidney disease development and progression. Use of combinations of miRNAs together with other molecular markers could potentially improve diagnostic or predictive power and facilitate clinical translation. In addition, targeting specific miRNAs at different stages of disease could be a promising therapeutic strategy.

The Potential of miR-370-3p and miR-495-3p Serving as Biomarkers for Sepsis-Associated Acute Kidney Injury

Objective

This study is aimed at evaluating the miR-370-3p and miR-495-3p expression in the urine of patients with sepsis-associated acute kidney injury (SA-AKI) and exploring its diagnosis value in for SA-AKI.

Methods

184 sepsis invalids were collected and divided two groups (non-AKI group or AKI group) according to whether they had acute kidney injury. RT-qPCR was utilized to measure miR-370-3p and miR-495-3p expressions. ROC curve was performed to evaluate the diagnostic value of miR-370-3p and miR-495-3p for SA-AKI. Patients diagnosed with SA-AKI were followed up for 28 days to record survival time. The prognostic performance of miR-370-3p and miR-495-3p for SA-AKI was evaluated by survival curves.

Results

Compared with non-AKI invalids, miR-370-3p and miR-495-3p expressions were obviously lower in the urine of AKI invalids. miR-370-3p and miR-495-3p expressions were markedly negatively correlated with biomarkers of renal injury. Furthermore, the area under the curve (AUC) of miR-370-3p and miR-495-3p for diagnosing sepsis SA-AKI was 0.896 and 0.814, respectively. The higher 28 days-survival rate was observed in patients with high miR-370-3p and miR-495-3p expressions.

Conclusions

A novel biomarker for the early diagnosis of SA-AKI may be miR-370-3p and miR-495-3p, which was clearly reduced in the urine of SA-AKI patients.

Clinical value of serum miR-320-3p expression in predicting the prognosis of sepsis-induced acute kidney injury

BACKGROUND

For investigating the expression of miR-320-3p in children with sepsis-induced acute kidney injury (AKI) and its prognostic value.

METHODS

A total of 142 patients were grouped into a survival group (n = 95) and death group (n = 47), which was based on their 28-day survival. Serum degrees of miR-320-3p, neutrophil gelatinase-associated lipid carrier protein (NGAL) and kidney injury molecule-1 (KIM-1) were detected. The Acute Physiology and Chronic Health scoring system Ⅱ (APACHE Ⅱ) marks were recorded. Target gene forecast and functional enrichment discussion of miR-320-3p were performed, and a protein-protein interaction (PPI) network diagram was plotted by applying bioinformatics methods. Multivariate logistic regression, ROC curve and Pearson correlation analysis were applied.

RESULTS

The death group showed greatly higher serum levels of miR-320-3p, KIM-1 and APACHE Ⅱ scores than the survival group (p < 0.01). Multivariate logistic regression analysis showed that levels of miR-320-3p, NGAL, KIM-1 and APACHE Ⅱ scores were independent risk elements for death in sepsis children with AKI (p < 0.01). According to ROC curve analysis, the region under the curve (0.963, 95% CI: 0.908-0.996) of miR-320-3p, NGAL, KIM-1 levels and APACHE Ⅱ scores combined to forecast the death of kids suffering from sepsis and AKI were the biggest. According to correlation analysis, the expression degree of serum miR-320-3p in the death group was positively correlated with NGAL, KIM-1 and APACHE Ⅱ scores (all p < 0.01).

CONCLUSIONS

The expression level of serum miR-320-3p in children with sepsis-induced AKI was significantly increased, and the combination of NGAL, KIM-1 and APACHE Ⅱ scores has good value for prognosis prediction in children.

Non-Coding RNAs in Sepsis-Associated Acute Kidney Injury

Sepsis is a systemic inflammatory response caused by a severe infection that leads to multiple organ damage, including acute kidney injury (AKI). In intensive care units (ICU), the morbidity and mortality associated with sepsis-associated AKI (SA-AKI) are gradually increasing due to lack of effective and early detection, as well as proper treatment. Non-coding RNAs (ncRNAs) exert a regulatory function in gene transcription, RNA processing, post-transcriptional translation, and epigenetic regulation of gene expression. Evidence indicated that miRNAs are involved in inflammation and programmed cell death during the development of sepsis-associated AKI (SA-AKI). Moreover, lncRNAs and circRNAs appear to be an essential regulatory mechanism in SA-AKI. In this review, we summarized the molecular mechanism of ncRNAs in SA-AKI and discussed their potential in clinical diagnosis and treatment.

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.