RETRACTED: Long non-coding RNA NEAT1 plays an important role in sepsis-induced acute kidney injury by targeting miR-204 and modulating the NF-κB pathway

Insights into non-coding RNAS: biogenesis, function and their potential regulatory roles in acute kidney disease and chronic kidney disease

Noncoding RNAs (ncRNAs) have emerged as pivotal regulators of gene expression, and have attracted significant attention because of their various roles in biological processes. These molecules have transcriptional activity despite their inability to encode proteins. Moreover, research has revealed that ncRNAs, especially microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs), are linked to pervasive regulators of kidney disease, including anti-inflammatory, antiapoptotic, antifibrotic, and proangiogenic actions in acute and chronic kidney disease. Although the exact therapeutic mechanism of ncRNAs remains uncertain, their value in treatment has been studied in clinical trials. The numerous renal diseases and the beneficial or harmful effects of NcRNAs on the kidney will be discussed in this article. Afterward, exploring the biological characteristics of ncRNAs, as well as their purpose and potential contributions to acute and chronic renal disease, were explored. This may offer guidance for treating both acute and long-term kidney illnesses, as well as insights into the potential use of these indicators as kidney disease biomarkers.

Long noncoding RNA: An emerging diagnostic and therapeutic target in kidney diseases

Long noncoding RNAs (lncRNAs) have critical roles in the development of many diseases including kidney disease. An increasing number of studies have shown that lncRNAs are involved in kidney development and that their dysregulation can result in distinct disease processes, including acute kidney injury, chronic kidney disease, and renal cell carcinoma. Understanding the roles of lncRNAs in kidney disease may provide new diagnostic and therapeutic opportunities in the clinic. This review provides an overview of lncRNA characteristics, and biological function and discusses specific studies that provide insight into the function and potential application of lncRNAs in kidney disease treatment.

Glomerular injury after trauma, burn, and sepsis

Acute kidney injury development after trauma, burn, or sepsis occurs frequently but remains a scientific and clinical challenge. Whereas the pathophysiological focus has mainly been on hemodynamics and the downstream renal tubular system, little is known about alterations upstream within the glomerulus post trauma or during sepsis. Particularly for the glomerular endothelial cells, mesangial cells, basal membrane, and podocytes, all of which form the glomerular filter, there are numerous in vitro studies on the molecular and functional consequences upon exposure of single cell types to specific damage- or microbial-associated molecular patterns. By contrast, a lack of knowledge exists in the real world regarding the orchestrated inflammatory response of the glomerulus post trauma or burn or during sepsis. Therefore, we aim to provide an overview on the glomerulus as an immune target but also as a perpetrator of the danger response to traumatic and septic conditions, and present major players involved in the context of critical illness. Finally, we highlight research gaps of this rather neglected but worthwhile area to define future molecular targets and therapeutic strategies to prevent or improve the course of AKI after trauma, burn, or sepsis.

Long non-coding RNAs ANRIL, THRIL, and NEAT1 as potential circulating biomarkers of SARS-CoV-2 infection and disease severity

The current outbreak of coronavirus disease 2019 (COVID-19) is a global emergency, as its rapid spread and high mortality rate, which poses a significant threat to public health. Innate immunity plays a crucial role in the primary defense against infections, and recent studies have highlighted the pivotal regulatory function of long non-coding RNAs (lncRNAs) in innate immune responses. This study aims to assess the circulating levels of lncRNAs namely ANRIL, THRIL, NEAT1, and MALAT1 in the blood of moderate and severe SARS-CoV-2 infected patients, in comparison to healthy individuals. Additionally, it aims to explore the potential of these lncRNAs as biomarkers for determining the severity of the disease. The blood samples were collected from a total of 38 moderate and 25 severe COVID-19 patients, along with 30 healthy controls. The total RNA was extracted and qPCR was performed to evaluate the blood levels of the lncRNAs. The results indicate significantly higher expression levels of lncRNAs ANRIL and THRIL in severe patients when compared to moderate patients (P value = 0.0307, P value = 0.0059, respectively). Moreover, the expression levels of lncRNAs ANRIL and THRIL were significantly up-regulated in both moderate and severe patients in comparison to the control group (P value < 0.001, P value < 0.001, P value = 0.001, P value < 0.001, respectively). The expression levels of lncRNA NEAT1 were found to be significantly higher in both moderate and severe COVID-19 patients compared to the healthy group (P value < 0.001, P value < 0.001, respectively), and there was no significant difference in the expression levels of NEAT1 between moderate and severe patients (P value = 0.6979). The expression levels of MALAT1 in moderate and severe patients did not exhibit a significant difference compared to the control group (P value = 0.677, P value = 0.764, respectively). Furthermore, the discriminative power of ANRIL and THRIL was significantly higher in the severe patient group than the moderate group (Area under curve (AUC) = 0.6879; P-value = 0.0122, AUC = 0.6947; P-value = 0.0093, respectively). In conclusion, the expression levels of the lncRNAs ANRIL and THRIL are correlated with the severity of COVID-19 and can be regarded as circulating biomarkers for disease progression.

The ability of long non-coding RNA RP11-284N8.3 to predict the risk, the severity and 28-day mortality of adults with sepsis

In a prior study, we identified a novel sepsis specific long noncoding RNAs (lncRNA) RP11-284N8.3, which may primarily participate in T cell activation and immune response during sepsis. However, the clinical significance of lncRNA RP11-284N8.3 in sepsis remains entirely unknown. This single-center prospective cohort study enrolled 147 adults with sepsis and 74 healthy controls (HCs) with matched age and sex between January 2021 and November 2022 at our hospital. Blood samples and clinical data were collected from HCs at enrollment and from adults with sepsis within 24 hours after admission. lncRNA RP11-284N8.3 expression was detected by RT-qPCR. The relative expression of lncRNA RP11-284N8.3 was significantly decreased in adults with sepsis compared to HCs (P < .0001), in adults with septic shock compared to adults without shock (P = .0012), and in 28-day deaths compared to 28-day survivors (P = .0006). receiver operating characteristic curves of lncRNA RP11-284N8.3 in predicting sepsis severity and 28-day mortality showed an area under the curve of 0.6570 (95% confidence interval [CI]: 0.5701-0.7440) and an area under the curve of 0.6765 (95% CI: 0.5809-0.7721), respectively. Multivariate logistic regression analysis revealed that lncRNA RP11-284N8.3 was an independent risk factor for 28-day mortality in adults with sepsis (odds ratio: 0.1057, 95% CI: 0.0115-0.7746, P = .0328). Low expression of lncRNA RP11-284N8.3 is correlated with increased risk, severity and 28-day mortality in adults with sepsis, and it may function as a potential biomarker to facilitate the diagnosis and management of sepsis.

Long Noncoding RNA and mRNA Expression Profiles in Rats with LPS-induced Myocardial Dysfunction

Background

Sepsis is an uncontrolled systemic inflammatory response. Long noncoding RNAs (lncRNAs) are involved in the pathogenesis of sepsis. However, little is known about the roles of lncRNAs in sepsis-induced myocardial dysfunction.

Objective

We aimed to determine the regulatory mechanism of lncRNAs in sepsis-induced myocardial dysfunction.

Methods

In this study, we analysed the lncRNA and mRNA expression profiles using microarray analysis. Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, protein-protein interaction network, and gene set enrichment analysis were used to evaluate the data. We also constructed coding and noncoding coexpression and competing endogenous RNA networks to investigate the mechanisms.

Results

In vivo lipopolysaccharide -induced sepsis rat model was established. A total of 387 lncRNAs and 1,952 mRNAs were identified as significantly changed in the left ventricle. Kyoto Encyclopedia of Genes and Genomes analysis of mRNAs showed that the upregulated genes were mainly enriched in the "complement and coagulation cascade pathway" and "immune-related biological processes" terms. Eight significantly changed lncRNAs detected by RT-qPCR may be responsible for these processes. A competing endogenous RNA network was generated, and the results indicated that eight lncRNAs were related to the "calcium ion binding" process.

Conclusion

These results demonstrate that crosstalk between lncRNAs and mRNAs may play important roles in the development of sepsis-induced myocardial dysfunction.

LncRNA NEAT1 accelerates renal fibrosis progression via targeting miR-31 and modulating RhoA/ROCK signal pathway

Renal fibrosis is the final pathway for chronic kidney disease to end-stage renal failure. Noncoding RNAs have been reported to play a crucial role in renal fibrosis. Here, the effects of long noncoding RNA (lncRNA) nuclear-enriched abundant transcript 1 (NEAT1) and miR-31 on renal fibrosis and their regulatory mechanism were evaluated. RT-qPCR was used to assess NEAT1, miR-31, and RhoA levels. Western blot was performed to analyze the expression of fibrosis markers, RhoA, rho-related kinase (ROCK1), and connective tissue growth factor (CTGF). RNA immunoprecipitation (RIP), fluorescence in situ hybridization (FISH), and luciferase reporter assays verified the interaction between miR-31 and NEAT1 or RhoA. Renal fibrosis and injury were observed by Masson and hematoxylin and eosin (H&E) staining. The expression level of inflammatory cytokines was detected by ELISA. Immunohistochemistry (IHC) was performed to examine the expression levels of α-smooth muscle actin (α-SMA) and RhoA in renal tissues. We showed that NEAT1 was highly expressed, whereas miR-31 was decreased in renal fibrosis. NEAT1 was found to directly bind miR-31 to positively regulate RhoA expression. Furthermore, NEAT1 silencing inhibited renal fibrosis and inflammation and suppressed the RhoA/ROCK1 signaling pathway. However, knockdown of miR-31 could reverse these effects. NEAT1 silencing or overexpression of miR-31 alleviated renal fibrosis in vivo. In conclusion, NEAT1 accelerates renal fibrosis progression via negative regulation of miR-31 and the activation of RhoA/ROCK1 pathway, thereby upregulating the expression level of CTGF, providing a theoretical basis for treatment and prognostic evaluation of renal fibrosis.

mmu-lncRNA 121686/hsa-lncRNA 520657 induced by METTL3 drive the progression of AKI by targeting miR-328-5p/HtrA3 signaling axis

The pathogenesis of acute kidney injury (AKI) is still not fully understood, and effective interventions are lacking. Here, we explored whether methyltransferase 3 (METTL3) was involved in the progression of AKI via regulation of cell death. We reported that PT（proximal tubule）-METTL3-knockout (KO) noticeably suppressed ischemic-induced AKI via inhibition of renal cell apoptosis. Furthermore, we also found that the expression of mmu-long non-coding RNA (lncRNA) 121686 was upregulated in antimycin-treated Boston University mouse proximal tubule (BUMPT) cells and a mouse ischemia-reperfusion (I/R)-induced AKI model. Functionally, mmu-lncRNA 121686 could promote I/R-induced mouse renal cell apoptosis. Mechanistically, mmu-lncRNA 121686 acted as a competing endogenous RNA (ceRNA) to prevent microRNA miR-328-5p-mediated downregulation of high-temperature requirement factor A 3 (Htra3). PT-mmu-lncRNA 121686-KO mice significantly ameliorated the ischemic-induced AKI via the miR-328-5p/HtrA3 axis. In addition, hsa-lncRNA 520657, homologous with lncRNA 121686, sponged miR-328-5p and upregulated Htra3 to promote I/R-induced human renal cell apoptosis. Interestingly, we found that mmu-lncRNA 121686/hsa-lncRNA 520657 upregulation were dependent on METTL3 via N⁶-methyladenosine (m⁶A) modification. The mmu-lncRNA 121686/miR-328-5p or hsa-lncRNA 520657/miR-328-5p /HtrA3 axis was induced in vitro by METTL3 overexpression; in contrast, this effect was attenuated by METTL3 small interfering RNA (siRNA). Furthermore, we found that PT-METTL3-KO or METTL3 siRNA significantly suppressed ischemic, septic, and vancomycin-induced AKI via downregulation of the mmu-lncRNA 121686/miR-328-5p/HtrA3 axis. Taken together, our data indicate that the METTL3/mmu-lncRNA 121686/hsa-lncRNA 520657/miR-328-5p/HtrA3 axis potentially acts as a therapeutic target for AKI.

Analysis of exosome-derived microRNAs as early biomarkers of lipopolysaccharide-induced acute kidney injury in rats

Sepsis contributes to the high prevalence of acute kidney injury (AKI), which mainly occurs in hospitalized patients. The delay in AKI detection is a risk factor for death and chronicity; thus, early diagnosis is essential for initiating proper treatment strategies. Although serum creatinine is used as biomarker, it is increased in plasma serum creatinine only at late stages of AKI. MicroRNAs (miRNAs), a class of noncoding RNAs responsible for gene regulation, can be found in biological fluids within vesicles such as exosomes and may be promising tools for the early detection of AKI. We aimed to identify potential blood miRNAs that can be used as early biomarkers of sepsis-induced AKI in rats. Adult male Wistar rats received a single dose of lipopolysaccharide (LPS). The earliest significant increase in serum creatinine was detected 4 h after LPS administration. To evaluate whether miRNAs could act as early biomarkers, blood samples were collected before and 2 h after LPS infusion. Serum NGAL levels were used as a comparative marker. Serum miRNAs were derived from exosomes, and their expression were evaluated by the PCR array. miR-181a-5p and miR-23b-3p showed higher expression in LPS-treated rats than in the control animals (p < 0.05). Bioinformatics analysis showed that both miRNAs target molecules associated with transcription factors that regulate genes related to proinflammatory cytokines. Considering that LPS activates transcription factors that lead to the production of proinflammatory cytokines, possible premature changes in the serum levels of miR-181a-5p and miR-23b-3p may be used to identify sepsis-induced AKI earlier.

circ-Katnal1 Enhances Inflammatory Pyroptosis in Sepsis-Induced Liver Injury through the miR-31-5p/GSDMD Axis

Background. Sepsis is a systemic inflammatory response that can elicit organ dysfunction as well as circulatory diseases in serious cases. When inflammatory responses are especially dysregulated, severe complications can arise, including sepsis-induced liver injury. Various microRNAs along with circular (circ) RNAs are involved in inflammatory responses; nevertheless, their functions in regulating sepsis-induced liver injury remain unknown. The cecal ligation and puncture (CLP) procedure can induce liver injury as well as polymicrobial sepsis. Methods. In this study, CLP was used to induce liver injury as well as polymicrobial sepsis. Then, liver function, inflammatory cytokine expression, and hepatic histopathology were evaluated. High-throughput sequencing was employed to investigate the abnormal hepatic circRNA expression after CLP. Raw264.7 cells were utilized to simulation an in vitro sepsis inflammation model with LPS induce. The relative mRNA as well as protein levels of TNF-α, IL-1β, and IL-6 was explored by quantitative polymerase chain reaction (PCR) and enzyme-linked immunosorbent assays. We explored functional connections among circRNAs, miR-31-5p, and gasdermin D (GSDMD) using dual-luciferase reporter assays. Western blot was employed to test GSDMD, caspase-1, and NLRP3 expression in mice and cell models. Results. Our results showed that CLP-induced sepsis promoted liver injury via increasing inflammatory pyroptosis. The abnormal expression of circ-Katnal1 played an important role in CLP-induced sepsis. Downregulating circ-Katnal1 suppressed LPS-induced inflammatory pyroptosis in Raw264.7 cells. Bioinformatics and luciferase reporter results confirmed that miR-31-5p and GSDMD were downstream targets of circ-Katnal1. Inhibiting miR-31-5p or upregulating GSDMD reversed the protective effects of silencing circ-Katnal1. Conclusion. Taken together, circ-Katnal1 enhanced inflammatory pyroptosis in sepsis-induced liver injury through the miR-31-5p/GSDMD axis.

Association of long non-coding RNAs NEAT1, and MALAT1 expression and pathogenesis of Behçet's disease among Egyptian patients

Behçet's disease (BD) is a chronic inflammatory disease. Immunological defects have been shown to play a significant role in the progression of BD. The serum levels of two long non-coding RNAs (lncRNAs), NEAT1 and MALAT1, were examined in patients with BD to identify their role in the disease pathogenesis. Both lncRNAs were mentioned as essential regulators of innate immune responses and have a crucial role in inflammatory diseases. Fifty patients with BD and a similar number of control individuals were involved in our study. At enrollment, data was collected from patients and controls, and the disease severity in active cases was determined using the Behçet's Disease Current Activity Form (BDCAF). Levels of the two studied biomarkers in the serum, NEAT1 and MALAT1, were investigated by quantitative RT-PCR (qRT-PCR). NEAT1 levels were significantly turned down in BD patients (fold changes = 0.77, p = 0.0001) and correlated negatively with the BDCAF (r = −0.41; p = 0.003). On the other hand, the MALAT1 levels were significantly up-regulated in BD patients (fold changes = 2.65, p = 0.003). Serum levels of NEAT1 were significantly decreased in patients with active states than in stationary cases (0.387 versus 1.99, respectively; p = 0.01) and compared with controls (p = 0.001). Also, NEAT1 levels were significantly increased in patients with stationary states compared to controls (p = 0.03). There was a positive association between NEAT1 and MALAT1 levels among BD patients (r = 0.29, p = 0.04). Our findings demonstrate a possible role of NEAT1 and MALAT1 in the pathogenesis of BD.

LncRNA OIP5-AS1 reduces renal epithelial cell apoptosis in cisplatin-induced AKI by regulating the miR-144-5p/PKM2 axis

BACKGROUND

The abnormal expression of long non-coding RNA (lncRNA) Opa-interacting protein 5 antisense RNA 1 (OIP5-AS1) has been observed in many human cancers and the underlying mechanisms have been well studied. However, the function of OIP5-AS1 in acute kidney injury (AKI) remains unclear.

METHODS

To explore the role of OIP5-AS1 in the progression of AKI, the cisplatin-induced AKI mouse and cell model were established. To confirm the potential protective effect of OIP5-AS1 during cisplatin-induced AKI, rescue experiments were performed. Targetscan was used to predict the potential targets of miR-144-5p. To further determine whether the effect of miR-144-5p during cisplatin-induced AKI was mediated by PMK2, the recuse experiments using PMK2 overexpressing vector was applied.

RESULTS

OIP5-AS1 was significantly downregulated both in cisplatin-induced AKI mice and human renal tubular cell line HK-2 cells. Moreover, overexpression of OIP5-AS1 efficiently promoted cell growth and reduced cisplatin-induced apoptosis of HK-2 cells. Furthermore, OIP5-AS1 was identified as a sponge of miR-144-5p, and upregulation of miR-144-5p could significantly reverse overexpression of OIP5-AS1-induced protective effect on the damage of cisplatin to HK-2 cells. In addition, pyruvate kinase M2 (PKM2) was found to be a direct target of miR-144-5p, and overexpression of PKM2 efficiently reversed the effect of miR-144-5p mimics on the damage in cisplatin-stimulated HK-2 cells.

CONCLUSIONS

OIP5-AS1 reduced the apoptosis of cisplatin-stimulated renal epithelial cells by targeting the miR-144-5p/PKM2 axis, which extended the regulatory network of lncRNAs in cisplatin-induced AKI and also provided a novel therapeutic target for AKI treatment.

LncRNA NEAT1/microRNA‑124 regulates cell viability, inflammation and fibrosis in high‑glucose‑treated mesangial cells

Long non-coding RNA (lncRNA) nuclear enriched abundant transcript 1 (NEAT1) has been frequently found to be dysregulated, which contributes to diabetes-related complications. The present study aimed to explore the effect of knockdown on mouse mesangial cell (MMC) viability, apoptosis, inflammation and fibrosis in an in vitro model of diabetic nephropathy (DN). The SV40 MES13 MMC cell line was first cultured with high glucose to establish an in vitro MMC DN cell model. Lnc-NEAT1 shRNA or the negative control shRNA were transfected into MMC DN cells, followed by the measurement of cell viability, apoptosis, inflammation, fibrosis and microRNA (miR)-124 expression, a known target of lnc-NEAT1, using Cell Counting Kit-8, flow cytometry, ELISA, western blotting [Capain1 (capn1), β-catenin (CTNNB1), cleaved caspase 3, cleaved poly-(ADP ribose) polymerase, fibronectin and Collagen] and reverse transcription-quantitative PCR (Capn1, CTNNB1, lnc-NEAT1, fibronectin, collagen and miR-124), respectively. In rescue experiments, the miR-124 and negative control inhibitor were co-transfected into lnc-NEAT1-downregulated cells, following which cell viability, apoptosis, inflammation, fibrosis, capn1 and CTNNB1 expression were measured. Lnc-NEAT1 expression was increased in high glucose-treated cells compared with that in normal glucose-treated cells and osmotic control cells, suggesting that lnc-NEAT1 is overexpressed in the MMC DN cell model. In the MMC DN cell model, lncRNA-NEAT1 knockdown enhanced cell apoptosis but reduced cell viability and the secretion of inflammatory cytokines in the supernatant (IL-1β, IL-8, monocyte chemotactic protein 1 and TNF-α), in addition to reducing the expression of fibrosis markers fibronectin and collagen I in the lysates. Lnc-NEAT1 knockdown increased miR-124 expression. Furthermore, transfection with the miR-124 inhibitor reduced cell apoptosis but increased cell viability, inflammation and fibrosis in lnc-NEAT1-downregulated MMC DN cells. miR-124 inhibitor transfection also increased the expression levels of Capn1 and CTNNB1. Taken together, the findings of the present study demonstrated that lnc-NEAT1 knockdown was able to attenuate MMC viability, inflammation and fibrosis by regulating miR-124 expression and the Capn1/β-catenin signaling pathway downstream. Therefore, Lnc-NEAT1 may serve as a potential therapeutic target for DN.

LncRNA NEAT1 correlates with Th17 cells and proinflammatory cytokines, also reflects stenosis degree and cholesterol level in coronary heart disease patients

BACKGROUND

Long non-coding RNA nuclear enriched abundant transcript 1 (lnc-NEAT1) regulates endothelial cell functions, CD4+ T cell regulation and chronic inflammation related to coronary heart disease (CHD). Then this case-control study measured lnc-NEAT1 expression in CHD patients, aiming to explore its clinical value in CHD management.

METHODS

Totally, 120 documented CHD patients and 120 suspected subjects without CHD diagnosis as controls were enrolled. Plasma lnc-NEAT1 was detected by RT-qPCR in all participants, plasma inflammatory cytokines were assessed by ELISA, T helper (Th) 1, Th2, Th 17 cell proportions in CD4+ T cells were analyzed by flow cytometric analysis in CHD patients, respectively.

RESULTS

Lnc-NEAT1 was higher in CHD patients than in controls (p < 0.001). In CHD patients, lnc-NEAT1 positively associated with Gensini score (r = 0.323, p < 0.001). Besides, lnc-NEAT1 positively correlated with tumor necrosis factor-α (r = 0.271, p = 0.003), interleukin (IL)-1β (r = 0.216, p = 0.018), IL-6 (r = 0.217, p = 0.018) and IL-17 (r = 0.292, p = 0.001); meanwhile, it was positively associated with the percentage of Th 17 cells (r = 0.384, p = 0.002). However, no correlation was found in lnc-NEAT1 with the percentage of Th1 or Th2 cells (all p > 0.05). Moreover, lnc-NEAT1 was correlated with higher hyperuricemia prevalence (p = 0.028), increased total cholesterol (r = 0.263, p = 0.004) and low-density lipoprotein cholesterol (r = 0.261, p = 0.004), but was not associated with other characteristics (all p > 0.05).

CONCLUSION

Lnc-NEAT1 correlates with Th17 cells and proinflammatory cytokines, also reflects stenosis degree and cholesterol level in CHD patients, which potentially improves the management of CHD patients.

The expression patterns of MALAT-1, NEAT-1, THRIL, and miR-155-5p in the acute to the post-acute phase of COVID-19 disease

Introduction

One of the hallmarks of COVID-19 is overwhelming inflammation, which plays a very important role in the pathogenesis of COVID-19. Thus, identification of inflammatory factors that interact with the SARS-CoV-2 can be very important to control and diagnose the severity of COVID-19. The aim of this study was to investigate the expression patterns of inflammation-related non-coding RNAs (ncRNAs) including MALAT-1, NEAT-1, THRIL, and miR-155-5p from the acute phase to the recovery phase of COVID-19.

Methods

Total RNA was extracted from Peripheral Blood Mononuclear Cell (PBMC) samples of 20 patients with acute COVID-19 infection and 20 healthy individuals and the expression levels of MALAT-1, NEAT-1, THRIL, and miR-155-5p were evaluated by real-time PCR assay. Besides, in order to monitor the expression pattern of selected ncRNAs from the acute phase to the recovery phase of COVID-19 disease, the levels of ncRNAs were re-measured 6‒7 weeks after the acute phase.

Result

The mean expression levels of MALAT-1, THRIL, and miR-155-5p were significantly increased in the acute phase of COVID-19 compared with a healthy control group. In addition, the expression levels of MALAT-1 and THRIL in the post-acute phase of COVID-19 were significantly lower than in the acute phase of COVID-19. According to the ROC curve analysis, these ncRNAs could be considered useful biomarkers for COVID-19 diagnosis and for discriminating between acute and post-acute phase of COVID-19.

Discussion

Inflammation-related ncRNAs (MALAT-1, THRIL, and miR-150-5p) can act as hopeful biomarkers for the monitoring and diagnosis of COVID-19 disease.

MALAT1 regulates PCT expression in sepsis patients through the miR‐125b/STAT3 axis

Background

Procalcitonin (PCT) is an important marker in diagnosing sepsis. However, some other diseases can also cause an increase in PCT. PCT still has some limitations in the clinical application of diagnosing sepsis. Therefore, it is of great significance to clarify the regulatory mechanism of PCT expression in sepsis and provide new therapeutic targets for sepsis.

Methods

Blood samples from clinical patients were collected, and peripheral blood monocytes were isolated. Bioinformatics was performed to find the ceRNA regulatory network of STAT3/PCT. MALAT1 and miR‐125b were detected by qRT‐PCR. MALAT1 was located by fluorescence in situ hybridization (FISH) in U937 cells, and the regulatory relationship between MALAT1, miR‐125b, and STAT3 was verified by double luciferase activity report and RNA pull‐down assay. U937 cells were transfected with miR‐125b, and the effects of the MALAT1/miR‐125b/STAT3 pathway on gene and protein secretion levels of PCT were verified by qRT‐PCR, western blot, and ELISA.

Results

In the serum of sepsis patients and lipopolysaccharide(LPS)‐induced U937 cells, MALAT1, STAT3, and PCT gene expression levels were significantly increased, while miR‐125b expression level was decreased. FISH results showed that the MALAT1 transcript was mainly located in the nucleus. The double luciferase activity report and RNA pull‐down assay results suggested a targeted regulatory relationship between MALAT1, miR‐125b, and STAT3. LPS‐induced U937 cells transfection with MALAT1 siRNA decreased STAT3 protein expression and phosphorylation level and the expression of PCT. Co‐transfection with miR‐125b inhibitor effectively reversed this phenomenon.

Conclusions

MALAT1 could upregulate the expressions of STAT3 and PCT by targeted adsorption of miR‐125b.

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.

LncRNA NEAT1 knockdown ameliorates LPS-induced human kidney injury by mediating the miR-330-5p/FOXO3 axis

BACKGROUND

Sepsis is a systemic process with multiple inflammatory responses and organ injuries, particularly in the damage of the kidney. Recently, numerous studies suggest that long non-coding RNAs (lncRNAs) are involved in sepsis-related kidney injury. This study aimed to investigate the functional role and mechanism of lncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) in sepsis-related kidney injury.

METHODS

Cell model of kidney injury was constructed in human kidney 2 (HK-2) cells with the treatment of lipopolysaccharide (LPS). The expression of NEAT1 was measured by quantitative real-time PCR (qRT-PCR). Cell viability was examined using CCK-8 assay. Flow cytometry was performed to detect cell apoptosis, and apoptosis-related proteins were quantified by western blot. The release of proinflammatory cytokines was assessed by ELISA. Oxidative stress was assessed by the levels of SOD and MDA using kits. The putative relationship between miR-330-5p and NEAT1 or FOXO3 was confirmed using dual-luciferase reporter assay, RIP assay and pull-down assay.

RESULT

The expression of NEAT1 was increased in LPS-treated HK-2 cells. LPS exposure promoted apoptotic rate, inflammatory responses and oxidative stress in HK-2 cells, which were largely ameliorated by NEAT1 knockdown. MiR-330-5p was verified as a target of NEAT1, and miR-330-5p inhibition reversed the effects of NEAT1 knockdown in LPS-treated HK-2 cells. Moreover, FOXO3 was a target of miR-330-5p, and miR-330-5p restoration-blocked cell apoptosis, inflammation and oxidative stress in LPS-treated HK-2 cells were recovered by FOXO3 overexpression.

CONCLUSION

NEAT1 downregulation meliorated LPS-induced HK-2 cell injuries partly by regulating the miR-330-5p/FOXO3 pathway.

lncRNA Neat1 regulates neuronal dysfunction post sepsis via stabilization of hemoglobin subunit beta

Sepsis-associated encephalopathy (SAE) is characterized by acute and diffuse brain dysfunction and correlates with long-term cognitive impairments with no targeted therapy. We used a mouse model of sepsis-related cognitive impairment to examine the role of lncRNA nuclear enriched abundant transcript 1 (Neat1) in SAE. We observed that Neat1 expression was increased in neuronal cells from septic mice and that it directly interacts with hemoglobin subunit beta (Hbb), preventing its degradation. The Neat1/Hbb axis suppressed postsynaptic density protein 95 (PSD-95) levels and decreased dendritic spine density. Neat1 knockout mice exhibited decreased Hbb levels, which resulted in increased PSD-95 levels, increased neuronal dendritic spine density, and decreased anxiety and memory impairment. Neat1 silencing via the antisense oligonucleotide GapmeR ameliorated anxiety-like behavior and cognitive impairment post-sepsis. In conclusion, we uncovered a previously unknown mechanism of the Neat1/Hbb axis in regulating neuronal dysfunction, which may lead to a novel treatment strategy for SAE.

Calcium dobesilate alleviates renal dysfunction and inflammation by targeting nuclear factor kappa B (NF-κB) signaling in sepsis-associated acute kidney injury

Acute kidney injury (AKI) is a serious complication of sepsis that increases mortality and the risk of progression to chronic kidney disease. Oxidative stress and apoptosis are reported to exert critical function in the pathogenesis of sepsis-associated AKI. Calcium dobesilate (CaD) was reported to play a protective role in renal diseases. Therefore, we explored the antioxidant effect and potential mechanism of CaD in lipopolysaccharide (LPS)-induced AKI in mice. We evaluated renal function (blood urea nitrogen (BUN) and serum creatinine (SCr)), histopathology, oxidative stress (superoxide dismutase (SOD) and malondialdehyde (MDA)), inflammation cytokines, and apoptosis in kidneys of mice. The effect of CaD on NF-κB signaling was evaluated by Western blot. Our findings showed that CaD alleviated renal dysfunction and kidney injury, and also reversed upregulated MDA concentration and reduced SOD enzyme activity in AKI mice. Moreover, LPS-induced inflammatory response was attenuated by CaD. CaD treatment also reduced the apoptosis evoked by LPS. Additionally, CaD downregulated phosphorylation of nuclear factor kappa B (NF-κB) signaling components in LPS mice. Conclusively, CaD alleviates renal dysfunction and inflammation by targeting NF-κB signaling in sepsis-associated AKI.

The role of long non-coding RNA (lncRNA) nuclear paraspeckle assembly transcript 1 (NEAT1) in chronic periodontitis progression

Long non-coding RNA nuclear paraspeckle assembly transcript 1 (NEAT1) is a novel pro-inflammatory factor in severe human diseases. Since inflammatory plays important roles in periodontitis progression, we aimed to explore the role of NEAT1 in chronic periodontitis (CP) in vitro. We established a periodontitis cell model was established by Porphyromonas gingivalis lipopolysaccharide (Pg-LPS)-induced periodontal ligament cells (PDLCs). Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed to detect the expression of NEAT1, microRNA (miR)-200c-3p, and tumor necrosis factor receptor-associated factor 6 (TRAF6). Cell viability, inflammatory factors, and protein expression of Bcl-2, Bax, and TRAF6 were analyzed by MTT, enzyme-linked immunosorbent assay, and Western blot. The target relationships among NEAT1, miR-200c-3p, and TRAF6 were predicted by the StarBase/TargetScan software, and further validated by dual-luciferase reporter assay. In this research, NEAT1 is up-regulated in CP tissues and periodontitis model group. Silencing of NEAT1 and over-expression of miR-200c-3p enhanced cell viability and repressed apoptosis in the periodontitis model group. NEAT1 targets miR-200c-3p, and miR-200c-3p further targets TRAF6. MiR-200c-3p inhibitor or over-expression of TRAF6 reversed the promoting effect of NEAT1 knockdown on cell viability, and the inhibiting effects on inflammatory cytokines and cell apoptosis. Consequently, the silencing of NEAT1 inhibits inflammation and apoptosis via targeting miR-200c-3p/TRAF6 axis, thereby contributing to alleviate the progression of CP. This finding could provide an underlying target for the treatment of CP.

Elevated lncRNA-UCA1 upregulates EZH2 to promote inflammatory response in sepsis-induced pneumonia via inhibiting HOXA1

Sepsis is characterized by a dysregulated inflammatory response. We aimed to explore the role of the long non-coding RNA urothelial carcinoma associated 1 (lncRNA UCA1)/enhancer of zeste homolog 2 (EZH2)/homeobox A1 (HOXA1) axis in sepsis-induced pneumonia. The sepsis rat models and RLE-6TN cellular sepsis-induced pneumonia models were established using ligation and puncture (CLP) and lipopolysaccharide (LPS). The expression of UCA1, EZH2 and HOXA1 in rat lung tissues and RLE-6TN cells was detected. Then, the CLP rats were respectively treated with UCA1 up-regulation or UCA1 silencing, EZH2 overexpression to measure their roles in the pathology, apoptosis, inflammation and NF-κB mRNA and phosphorylated NF-κB p-65 levels in CLP rat lung tissues. The cells were subjected to same treatment to examine the effects of UCA1, EZH2 and HOXA1 on viability, apoptosis, inflammation and NF-κB mRNA and phosphorylated NF-κB p-65 levels in LPS-induced RLE-6TN cells. The interactions among UCA1, EZH2 and HOXA1 were identified. UCA1 and EZH2 were upregulated while HOXA1 was downregulated in CLP rat lung tissues and LPS-induced RLE-6TN cells. Elevated UCA1 or increased EZH2 aggravated pathology and promoted apoptosis, inflammation and NF-κB mRNA and phosphorylated NF-κB p-65 levels in CLP rat lung tissues, and inhibited viability while facilitated apoptosis, inflammation and NF-κB mRNA and phosphorylated NF-κB p-65 levels in LPS-induced RLE-6TN cells. UCA1 inhibition exerted contrary effects. Silenced EZH2 reversed the effects of UCA1 elevation on sepsis-induced pneumonia. UCA1 targeted EZH2 that interacted with HOXA1. UCA1 overexpression upregulates EZH2 to repress HOXA1 expression, thus aggravating the progression of sepsis-induced pneumonia, which could be alleviated by EZH2 inhibition.

Silencing Long Non-coding RNA Kcnq1ot1 Limits Acute Kidney Injury by Promoting miR-204-5p and Blocking the Activation of NLRP3 Inflammasome

Acute kidney injury (AKI) is a critical clinical disease characterized by an acute decrease in renal function. Long non-coding RNAs (LncRNAs) are important in AKI. This study aimed to explore the mechanism of lncRNA Kcnq1ot1 in AKI by sponging microRNA (miR)-204-5p as a competitive endogenous RNA (ceRNA). AKI mouse model and hypoxia/reoxygenation (H/R) model of human kidney (HK) cells were established. Kcnq1ot1 expression, cell proliferation, and apoptosis were measured. Binding relations among Kcnq1ot1, miR-204-5p, and NLRP3 were verified. Pathological changes and cell apoptosis were detected. The results showed that Kcnq1ot1 was highly expressed in the AKI model in vivo and in vitro. Kcnq1ot1 knockdown promoted cell proliferation and prevented apoptosis and inflammation. Furthermore, Kcnq1ot1 inhibited miR-204-5p expression by competitively binding to miR-204-5p in HK-2 cells. miR-204-5p targeted NLRP3 and NLRP3 overexpression averted the inhibiting effect of miR-204-5p on apoptosis and inflammation in HK-2 cells in vitro. Kcnq1ot1 knockdown in vivo promoted miR-204-5p expression, inhibited NLRP3 inflammasome activation, reduced levels of SCr, BUN, and KIM-1, and thus alleviated AKI and reduced apoptosis. In summary, silencing lncRNA Kcnq1ot1 inhibited AKI by promoting miR-204-5p and inhibiting NLRP3 inflammasome activation.

LncRNA NEAT1 accelerates the proliferation, oxidative stress, inflammation and fibrosis and suppresses the apoptosis via miR-423-5p/GLIPR2 axis in diabetic nephropathy

ABSTRACT

Diabetic nephropathy (DN) is a serious microvascular complication of diabetes. The aim of our study was to investigate the potential mechanism in DN progression. SV40 MES13 cells were exposed to high concentration of glucose (HG: 30 mmol/L) for 48 h to establish DN cell model in vitro. Bioinformatic software StarBase was adopted to establish long non-coding RNA (lncRNA)-microRNA (miRNA)-messenger RNA (mRNA) axis. Dual-luciferase reporter assay, RNA immunoprecipitation (RIP) assay and RNA-pull down assay were performed to verify intermolecular interaction. LncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) was overexpressed in the serum of DN patients. HG time-dependently up-regulated NEAT1 level, and HG promotes cell proliferation, oxidative stress, inflammation and fibrosis and suppressed cell apoptosis in SV40 MES13 cells partly via up-regulating NEAT1. NEAT1 functioned as a molecular sponge of miR-423-5p, and NEAT1 silencing-mediated effects were partly overturned by miR-423-5p interference in HG-induced SV40 MES13 cells. Glioma pathogenesis related-2 (GLIPR2) was a target of miR-423-5p. GLIPR2 overexpression in normal concentration of glucose (NG)-induced SV40 MES13 cells partly simulated HG-induced effects. GLIPR2 overexpression partly reversed NEAT1 interference-induced effects in HG-induced SV40 MES13 cells. LncRNA NEAT1 contributed to HG-induced DN progression via miR-423-5p/GLIPR2 axis in vitro. NEAT1/miR-423-5p/GLIPR2 axis might be potential target for DN treatment.

Resveratrol alleviates sepsis-induced acute kidney injury by deactivating the lncRNA MALAT1/MiR-205 axis

INTRODUCTION

Resveratrol plays a protective role against sepsis development, and the long noncoding RNA (lncRNA) MALAT1 is an inflammation-relevant biomarker. This investigation attempted to reveal whether resveratrol attenuated inflammation of sepsis-induced acute kidney injury (AKI) by regulating MALAT1.

MATERIAL AND METHODS

In total 120 rats were divided into a control group (n = 20), a Sham group (n = 20), a sepsis group (n = 40) and a resveratrol group (n = 40), and serum levels of inflammatory cytokines and AKI biomarkers were determined. An equal number of rats under identical treatments were, additionally, tracked for their survival, and the serum level of lncRNA MALAT1 was measured by RT-PCR. Moreover, septic cell models were constructed by treating HK-2 cells with lipopolysaccharide (LPS), and tumor necrosis factor α (TNF-α), interleukin (IL)-1β, IL-6 levels released by the cells were determined with ELISA.

RESULTS

Resveratrol treatment significantly brought down serum levels of inflammatory cytokines (i.e. TNF-α, IL-1β and IL-6), kidney function indicators (i.e. Scr, blood urea nitrogen [BUN] and Scys C), AKI biomarkers (i.e. NGAL and KIM-1) and MALAT1 in cecal ligation and puncture (CLP)-induced septic model rats (all p < 0.05), and the life span of septic rats was elongated by resveratrol treatment (p < 0.05). Viability and cytokine release of LPS-treated HK2 cells were rescued by resveratrol (p < 0.05), which was accompanied by a marked fall of MALAT1 expression (p < 0.05). In addition, si-MALAT1 diminished viability and suppressed cytokine release of HK2 cells, while pcDNA3.1-MALAT1 hindered the impact of resveratrol on the inflammatory response of HK2 cells (p < 0.05). Ultimately, miR-205, a protective molecule in sepsis-relevant AKI, was down-regulated by resveratrol and si-MALAT1 (p < 0.05).

CONCLUSIONS

Resveratrol relieved sepsis-induced AKI by restraining the lncRNA MALAT1/miR-205 axis.

Acetylation of H3K27 activated lncRNA NEAT1 and promoted hepatic lipid accumulation in non-alcoholic fatty liver disease via regulating miR-212-5p/GRIA3

Non-alcoholic fatty liver disease (NAFLD) was a world-wide health burden. H3K27 acetylation, long non-coding RNA (lncRNA), and miRNA were all implicated in NAFLD regulation, yet the detailed regulatory mechanism was not well understood. LncRNA NEAT1, miR-212-5p, and GRIA3 expression were detected both in high fatty acid-treated hepatocytes cells and NAFLD patients. Lipid droplets were stained and analyzed by oil red O staining. Expression of fatty acid synthase (FASN), acetyl-CoA carboxylase (ACC), and GRIA3 was detected by qRT-PCR and western blot. RNA level of lncRNA NEAT1 and miR-212-5p was analyzed by qRT-PCR. The binding sequences of lncRNA NEAT1/miR-212-5p and miR-212-5p/GRIA3 were predicted bioinformatically and validated through luciferase assay. ChIP was performed to analyze H3K27 acetylation on the promoter of lncRNA NEAT1. LncRNA NEAT1 and GRIA3 was upregulated, while miR-212-5p was downregulated in NAFLD patients. FFA promoted lncRNA NEAT1 and GRIA3 expression while suppressing miR-212-5p and promoted lipid accumulation as indicated by increased oil red O staining and FAS and ACC expression. ChIP indicated enrichment of H3K27 on NEAT1 promoter. Inhibition of H3K27 acetylation suppressed lncRNA NEAT1 level. Luciferase results indicated direct interaction of NEAT1/miR-212-5p (which was confirmed by RIP) and miR-212-5p/GRIA3. LncRNA NEAT1 knockdown upregulated miR-212-5p level and inhibited FFA-induced lipid accumulation while suppressing GRIA3 expression. Such function was antagonized by miR-212-5p inhibition and GRIA3 knockdown counteracted with miR-212-5p inhibition. H3K27 acetylation was enriched within the promoter of lncRNA NEAT1 and promoted lncRNA NEAT1 transcription. LncRNA NEAT1 could then interact with miR-212-5p and suppress its cellular concentration.

Long Non-Coding RNAs as Biomarkers and Therapeutic Targets in Sepsis

Sepsis, an infection-induced systemic inflammatory disorder, is often accompanied by multiple organ dysfunction syndromes with high incidence and mortality rates, and those who survive are often left with long-term sequelae, bringing great burden to social economy. Therefore, novel approaches to solve this puzzle are urgently needed. Previous studies revealed that long non-coding RNAs (lncRNAs) have exerted significant influences on the process of sepsis. The aim of this review is to summarize our understanding of lncRNAs as potential sepsis-related diagnostic markers and therapeutic targets, and provide new insights into the diagnosis and treatment for sepsis. In this study, we also introduced the current diagnostic markers of sepsis and discussed their limitations, while review the research advances in lncRNAs as promising biomarkers for diagnosis and prognosis of sepsis. Furthermore, the roles of lncRNAs in sepsis-induced organ dysfunction were illustrated in terms of different organ systems. Nevertheless, further studies should be carried out to elucidate underlying molecular mechanisms and pathological process of sepsis.

lncRNA NEAT1 aggravates sepsis-induced lung injury by regulating the miR-27a/PTEN axis

Sepsis is an acute inflammatory reaction and a cause of acute respiratory distress syndrome (ARDS). In the present study, we explored the roles and underlying mechanism of the lncRNA Nuclear enriched abundant transcript 1 (NEAT1) in ARDS. The expression levels of genes, proteins and pro-inflammatory cytokines in patients with ARDS, LPS-stimulated cells and septic mouse models were quantified using qPCR, western blotting and ELISA assays, respectively. The molecular targeting relationship was validated by conducting a dual-luciferase reporter assay. Cell proliferation was assessed using the Cell Counting Kit-8 (CCK-8) assay. The cell cycle phase was determined by flow cytometry assay. The expression levels of NEAT1 and pro-inflammatory cytokines were higher in patients with ARDS and septic models than in controls. Knockdown of NEAT1 significantly increased cell proliferation and cycle progression and prolonged mouse survival in vitro and in vivo. Mechanistically, miR-27a was identified as a downstream target of NEAT1 and directly inhibited PTEN expression. Further rescue experiments revealed that inhibition of miR-27a impeded the promoting effects of NEAT1 silence on cell proliferation and cycle progression, whereas inhibition of PTEN markedly weakened the inhibitory effects of NEAT1 overexpression on cell proliferation and cycle progression. Altogether, our study revealed that NEAT1 plays a promoting role in the progression of ARDS via the NEAT1/miR-27a/PTEN regulatory network, providing new insight into the pathologic mechanism behind ARDS.

NEAT1/miR-146a-3p/TrkB/ShcB axis regulates the development and function of chondrocyte

The current study aimed to explored the regulatory effect of Tropomyosin-related kinases B (TrkB) in the development and function of chondrocyte. Correlation between clinicopathological characteristics and osteoarthritis (OA) were analyzed. The expressions of TrkA, brain-derived neurotrophic factor (BDNF), TrkB, Src homolog and collagen homolog B (ShcB), and ShcC in OA cartilage tissue and IL-1β-stimulated chondrocytes from normal cartilage were determined by Western blot/qRT-PCR. After manipulating the expressions of TrkA, shTrkB, ShcB, miR-146a-3p and nuclear paraspeckle assembly transcript 1 (NEAT1), the differentiation-related molecules, and apoptosis-related molecules were examined by Western blot/qRT-PCR, and migration, invasion, proliferation, tube formation, and apoptosis rate in IL-1β-stimulated chondrocyte were examined by scratch, Transwell, colony formation, and tube formation, and flow cytometry assays, respectively. Bioinformatics, dual-luciferase and Spearman were used to analyze the binding and correlation of target genes. The findings showed that OA was related to body mass Index (BMI). The expressions of TrkA, TrkB and ShcB and NEAT1 were up-regulated in OA and IL-1β-stimulated chondrocytes, while miR-146a-3p was donwnregulated and was negatively correlated with TrkB or NEAT1. NEAT1 competed with TrkB in chondrocytes for miR-146a-3p binding. ShTrkB reversed the decrease in expressions of differentiation-related molecules, migration, invasion and proliferation, and the increase in ShcB expression and tube formation, of IL-1β-stimulated chondrocytes. Overexpressed ShcB reversed effect of shTrkB on the functions of IL-1β-stimulated chondrocytes. MiR-146a-3p inhibitor reversed effects of shTrkB on the function and apoptosis-related molecules on IL-1β-stimulated chondrocytes, while NEAT1 reversed role of miR-146a-3p. This paper demonstrated that NEAT1/miR-146a-3p/TrkB/ShcB axis regulates the development and function of chondrocyte.

Silencing CDK6-AS1 inhibits LPS-induced inflammatory damage in HK-2 cells

In this study, we aim to discover the importance of long non-coding RNA cyclin-dependent kinase 6 (CDK6)-AS1 in lipopolysaccharide (LPS)-induced HK-2 cells. We treated the HK-2 cells with LPS and knocked down CDK6-AS1 in HK-2 cells and then analyzed the effects of CDK6-AS1 on the viability of cell, cell apoptosis, the expression of cytokines via MTT, flow cytometry, enzyme-linked immunosorbent assay (ELISA), and qPCR. The results showed that silencing CDK6-AS1 alleviated LPS-induced inhibition of HK-2 cell proliferation, release of IL-1β, IL-8, IL-6, and TNF-α, cell apoptosis, and decrease in mitochondrial membrane potential. In addition, decreasing the level of CDK6-AS1 inhibited the reduction of Bcl-2 levels, the expression of Bax, cleaved caspade-9, and cleaved caspase-3, induced by LPS. In conclusion, lowering CDK6-AS1 level alleviates LPS-induced inflammatory damage in HK-2 cells.

Immunomodulatory Effects of Heme Oxygenase-1 in Kidney Disease

Kidney disease is a general term for heterogeneous damage that affects the function and the structure of the kidneys. The rising incidence of kidney diseases represents a considerable burden on the healthcare system, so the development of new drugs and the identification of novel therapeutic targets are urgently needed. The pathophysiology of kidney diseases is complex and involves multiple processes, including inflammation, autophagy, cell-cycle progression, and oxidative stress. Heme oxygenase-1 (HO-1), an enzyme involved in the process of heme degradation, has attracted widespread attention in recent years due to its cytoprotective properties. As an enzyme with known anti-oxidative functions, HO-1 plays an indispensable role in the regulation of oxidative stress and is involved in the pathogenesis of several kidney diseases. Moreover, current studies have revealed that HO-1 can affect cell proliferation, cell maturation, and other metabolic processes, thereby altering the function of immune cells. Many strategies, such as the administration of HO-1-overexpressing macrophages, use of phytochemicals, and carbon monoxide-based therapies, have been developed to target HO-1 in a variety of nephropathological animal models, indicating that HO-1 is a promising protein for the treatment of kidney diseases. Here, we briefly review the effects of HO-1 induction on specific immune cell populations with the aim of exploring the potential therapeutic roles of HO-1 and designing HO-1-based therapeutic strategies for the treatment of kidney diseases.

Dysregulated lncRNAs are Involved in the Progress of Sepsis by Constructing Regulatory Networks in Whole Blood Cells

Sepsis is a highly heterogeneous syndrome that is caused by an unbalanced host response to an infection. Long noncoding RNAs (lncRNAs) have been reported to exert regulatory roles in a variety of biological processes, and became potential biomarkers and therapeutic targets for diverse diseases. However, current understanding on the roles of lncRNAs in sepsis is extremely limited. Herein, to decipher the underlying functions of lncRNAs, we reexplored the 83 transcriptome datasets from specimens with sepsis, no_sepsis by final diagnosis, and control. The results of differentially expressed genes (DEGs), differentially expressed lncRNA (DElncRNA) analysis, and co-expression analysis of lncRNA–mRNA pairs were obtained. We found that the expression pattern of lncRNAs was significantly activated in sepsis specimens, which was clearly distinguished in sepsis from no_sepsis and control specimens. By performing co-expression analysis, we found DElncRNAs were closely related to T-cell activation and immune response–related terms in sepsis by regulating mRNA expression in the trans manner. The lncRNA–mRNA network and the qRT-PCR test revealed that lncRNAs LINC00861, RP11-284N8.3, and CTB-61M7.2 were significantly correlated with the pathogenesis of sepsis. In addition, weighted gene co-expression analysis (WGCNA) and cis-regulation analysis also revealed sepsis-specific lncRNAs were highly associated with important biological processes correlated with sepsis. In summary, the systematic dysregulation of lncRNAs is tightly involved in the remodeling of gene expression regulatory network in sepsis, and the lncRNA–mRNA expression network may be used to refine biomarker predictions for developing novel therapeutic approaches in sepsis.

Epigenetics in kidney diseases

Epigenetics examines heritable changes in DNA and its associated proteins except mutations in gene sequence. Epigenetic regulation plays fundamental roles in kidney cell biology through the action of DNA methylation, chromatin modification via epigenetic regulators and non-coding RNA species. Kidney diseases, including acute kidney injury, chronic kidney disease, diabetic kidney disease and renal fibrosis are multistep processes associated with numerous molecular alterations even in individual kidney cells. Epigenetic alterations, including anomalous DNA methylation, aberrant histone alterations and changes of microRNA expression all contribute to kidney pathogenesis. These changes alter the genome-wide epigenetic signatures and disrupt essential pathways that protect renal cells from uncontrolled growth, apoptosis and development of other renal associated syndromes. Molecular changes impact cellular function within kidney cells and its microenvironment to drive and maintain disease phenotype. In this chapter, we briefly summarize epigenetic mechanisms in four kidney diseases including acute kidney injury, chronic kidney disease, diabetic kidney disease and renal fibrosis. We primarily focus on current knowledge about the genome-wide profiling of DNA methylation and histone modification, and epigenetic regulation on specific gene(s) in the pathophysiology of these diseases and the translational potential of identifying new biomarkers and treatment for prevention and therapy. Incorporating epigenomic testing into clinical research is essential to elucidate novel epigenetic biomarkers and develop precision medicine using emerging therapies.

The Role of microRNAs in Pulp Inflammation

The dental pulp can be affected by thermal, physical, chemical, and bacterial phenomena that stimulate the inflammatory response. The pulp tissue produces an immunological, cellular, and vascular reaction in an attempt to defend itself and resolve the affected tissue. The expression of different microRNAs during pulp inflammation has been previously documented. MicroRNAs (miRNAs) are endogenous small molecules involved in the transcription of genes that regulate the immune system and the inflammatory response. They are present in cellular and physiological functions, as well as in the pathogenesis of human diseases, becoming potential biomarkers for diagnosis, prognosis, monitoring, and safety. Previous studies have evidenced the different roles played by miRNAs in proinflammatory, anti-inflammatory, and immunological phenomena in the dental pulp, highlighting specific key functions of pulp pathology. This systematized review aims to provide an understanding of the role of the different microRNAs detected in the pulp and their effects on the expression of the different target genes that are involved during pulp inflammation.

LncRNA NEAT1 correlates with Th1 and Th17 and could serve as an assistant biomarker in sepsis

Aim: Investigating correlation of lncRNA NEAT1 with Th1 and Th17 in sepsis, and their associations with inflammation, disease severity and prognosis. Materials & methods: A total of 127 sepsis patients and 50 health subjects were included. LncRNA NEAT1, Th1, Th17 and Th1/Th17-secreted cytokines were detected. Results: LncRNA NEAT1 positively correlated with Th1 and Th17 cell proportions in sepsis patients. LncRNA NEAT1 positively correlated with Th1 and Th17-secreted cytokine levels in sepsis patients. LncRNA NEAT1 and Th17 cell proportion positively correlated with CRP level, acute physiology and chronic health evaluation II score and sequential organ failure assessment score. High lncRNA NEAT1 expression, Th1 and Th17 cell proportions correlated with elevated accumulating mortality. Conclusion: LncRNA NEAT1 positively correlated with Th1 and Th17, and may serve as an assistant biomarker in sepsis patients.

Long noncoding RNAs: A potential target in sepsis-induced cellular disorder

Sepsis, an inflammation-related clinical syndrome, is characterized by disrupted immune homeostasis accompanied by infection and multiple organ dysfunction as determined by the Sequential Organ Failure Assessment (SOFA). Substantial evidence has recently suggested that lncRNAs orchestrate various biological processes in diseases, and lncRNAs play special roles in the diagnosis and management of sepsis. To date, very few reviews have provided clear and comprehensive clues to demonstrate the roles of lncRNAs in the pathogenesis of sepsis. Based on previously published studies, in this review, we summarize the different functions of lncRNAs in sepsis-induced cellular disorders and sepsis-induced organ failure to show the potential roles of lncRNAs in the diagnosis and management of sepsis. We further depict the function of some lncRNAs known to be pivotal regulators in the pathogenesis of sepsis to discuss the underlying molecular events. Additionally, we list and discuss several hotspots in research on lncRNAs, which may be conducive to future lncRNA-targeted therapeutic approaches for sepsis treatment.

LncRNA NEAT1 Promotes Inflammatory Response in Sepsis via the miR-31-5p/POU2F1 Axis

Sepsis is considered to be a systemic inflammatory response, which results in organ dysfunction. LncRNA nuclear-enriched abundant transcript 1 (NEAT1) involved in sepsis progression has been reported. However, the underlying mechanism of NEAT1 in sepsis-induced inflammatory response remains to be revealed. In this study, NEAT1 and POU domain class 2 transcription factor 1 (POU2F1) were highly expressed in LPS-induced septic RAW264.7 cells, opposite to miR-31-5p expression. Furthermore, we found that NEAT1 silencing inhibited LPS-induced inflammatory response and cell proliferation, and promoted cell apoptosis. Subsequently, we found that miR-31-5p interacted with NEAT1 and targeted the 3'UTR of POU2F1, and in LPS-induced RAW264.7 cells, the inhibition of NEAT1 silencing was reversed by miR-31-5p knockdown, while POU2F1 downregulation could cover the functions of miR-31-5p knockdown. In a word, this study indicates that NEAT1 inhibits the LPS-induced progression of sepsis in RAW264.7 cells by modulating miR-31-5p/POU2F1 axis, suggesting that NEAT1 will be the potential therapeutic target for sepsis.

Knockdown of lncRNA MALAT1 ameliorates acute kidney injury by mediating the miR-204/APOL1 pathway

Background

Acute kidney injury (AKI) was characterized by loss of renal function, associated with chronic kidney disease, end‐stage renal disease, and length of hospital stay. Long non‐coding RNAs (lncRNAs) participated in AKI development and progression. Here, we aimed to investigate the roles and mechanisms of lncRNA MALAT1 in AKI.

Methods

AKI serum samples were obtained from 129 AKI patients. ROC analysis was conducted to confirm the diagnostic value of MALAT1 in differentiating AKI from healthy volunteers. After hypoxic treatment on HK‐2 cells, the expressions of inflammatory cytokines, MALAT1, miR‐204, APOL1, p65, and p‐p65, were measured by RT‐qPCR and Western blot assays. The targeted relationship between miR‐204 and MALAT1 or miR‐204 and APOL1 was determined by luciferase reporter assay and RNA pull‐down analysis. After transfection, CCK‐8, flow cytometry, and TUNEL staining assays were performed to evaluate the effects of MALAT1 and miR‐204 on AKI progression.

Results

From the results, lncRNA MALAT1 was strongly elevated in serum samples from AKI patients, with the high sensitivity and specificity concerning differentiating AKI patients from healthy controls. In vitro, we established the AKI cell model after hypoxic treatment. After experiencing hypoxia, we found significantly increased MALAT1, IL‐1β, IL‐6, and TNF‐α expressions along with decreased miR‐204 level. Moreover, the targeted relationship between MALAT1 and miR‐204 was confirmed. Silencing of MALAT1 could reverse hypoxia‐triggered promotion of HK‐2 cell apoptosis. Meanwhile, the increase of IL‐1β, IL‐6, and TNF‐α after hypoxia treatment could be repressed by MALAT1 knockdown as well. After co‐transfection with MALAT1 silencing and miR‐204 inhibition, we found that miR‐204 could counteract the effects of MALAT1 on HK‐2 cell progression and inflammation after under hypoxic conditions. Finally, NF‐κB signaling was inactivated while APOL1 expression was increased in HK‐2 cells after hypoxia treatment, and lncRNA MALAT1 inhibition reactivated NF‐κB signaling while suppressed APOL1 expression by sponging miR‐204.

Conclusions

Collectively, these results illustrated that knockdown of lncRNA MALAT1 could ameliorate AKI progression and inflammation by targeting miR‐204 through APOL1/NF‐κB signaling.

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.

Comprehensive analysis of the long non-coding RNA expression profile and functional roles in a contrast-induced acute kidney injury rat model

Long non-coding RNAs (lncRNAs) have been identified as a class of regulatory RNAs that participate in both physiological and pathological conditions, including acute kidney injury. However, the roles of lncRNA dysregulation in the pathogenesis of contrast-induced acute kidney injury (CI-AKI) are largely unknown. In the present study, the expression profiles of lncRNAs in kidney tissue were compared between rats with CI-AKI and controls using high-throughput RNA sequencing. In total, 910 differentially expressed (DE) lncRNAs (DElncRNAs), including 415 downregulated and 495 upregulated lncRNAs, were identified at 12 h after intra-arterial iodinated contrast medium injection (fold change ≥2; P<0.05). Eight DElncRNAs were further selected and validated using reverse transcription-quantitative polymerase chain reaction. A previous study defined microRNA (miRNA) and mRNA expression changes in the same CI-AKI model. In the present study, a lncRNA-mRNA co-expression network comprising 349 DElncRNAs and 202 DEmRNAs was constructed. The function of these DElncRNAs was mainly associated with oxidative stress and inflammation. Additionally, lncRNA-associated competing endogenous RNA (ceRNA) analysis revealed a network comprising 40 DElncRNA nodes, 5 DEmiRNA nodes and 59 DEmRNA nodes. Among which, the carnosine dipeptidase 1-specific and the transmembrane protein 184B-specific networks were likely to be associated with CI-AKI. The results of the present study revealed the expression profile and potential roles of lncRNAs in CI-AKI, and provide a framework for further mechanistic studies.

miR-204: Molecular Regulation and Role in Cardiovascular and Renal Diseases

The field of microRNA research has evolved from studies aiming to gauge the importance of microRNAs to those focusing on understanding a subset of specific microRNAs that have emerged as potent regulators of molecular systems and pathophysiological conditions. In this article, we review the molecular features and regulation of miR-204 and the growing body of evidence for an important role of miR-204 in the regulation of cardiovascular and renal physiology and pathophysiological processes. miR-204 exhibits a highly tissue-specific expression pattern, and miR-204 abundance is regulated by several transcriptional and posttranscriptional mechanisms. Strong evidence supports a role for miR-204 in attenuating pulmonary arterial hypertension and hypertensive and diabetic renal injury while promoting hypertension and endothelial dysfunction in a wide range of model systems. miR-204 may influence these disease processes by targeting several biological pathways in a tissue-specific manner. miR-204 is dysregulated in patients with cardiovascular and renal diseases. The unequivocal functional roles and clear clinical relevance indicate that miR-204 is a high-value microRNA in cardiovascular and renal diseases.

Circular RNA TLK1 Promotes Sepsis-Associated Acute Kidney Injury by Regulating Inflammation and Oxidative Stress Through miR-106a-5p/HMGB1 Axis

Sepsis is an inflammatory disorder and leads to severe acute kidney injury (AKI). Circular RNAs (circRNAs) have been identified as a critical type of regulatory noncoding RNAs (ncRNAs) that present the important functions in various diseases. In this study, we identified a novel circRNA circTLK1 in the regulation of sepsis-induced AKI. We observed that circTLK1 expression was elevated in the cecal ligation and puncture (CLP) rat model compared with that in the control rats. The urine levels of neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (Kim-1) and the serum levels of creatinine (sCr) and blood urea nitrogen (BUN) were increased by the CLP treatment in the rats but were blocked by the circTLK1 shRNA. The circTLK1 shRNA reduced the CLP-induced kidney injury in the rats. The circTLK1 knockdown repressed oxidation stress, inflammation, and apoptosis in the sepsis-related AKI rat model. Moreover, lipopolysaccharide (LPS) treatment increased the production of TNF-α, IL-1β, and IL-6 in the HK-2 cells, while the circTLK1 shRNA could attenuate the enhancement in the cells. Bax and cleaved caspase-3 expression was upregulated, but Bcl-2 expression was downregulated by the LPS in the HK-2 cells, in which circTLK1 depletion reversed this effect in the cells. The depletion of circTLK1 attenuated the LPS-induced apoptosis in the HK-2 cells. CircTLK1 enhanced HMGB1 expression by sponging miR-106a-5p in the HK-2 cells, and miR-106a-5p and HMGB1 were involved in circTLK1-meidated injury of LPS-treated cells. Therefore, we concluded that circTLK1 contributed to sepsis-associated AKI by regulating inflammation and oxidative stress through the miR-106a-5p/HMGB1 axis. CircTLK1 and miR-106a-5p may be employed as the potential targets for the treatment of AKI.

MicroRNA miR-126 attenuates brain injury in septic rats via NF-κB signaling pathway

The purpose of this study was to investigate the impact and mechanism of microRNA miR-126 on brain injury induced by blood-brain barrier (BBB) damage in septic rats. We used cecal ligation and perforation (CLP) to create a rat model of sepsis. The experimental rats were randomly divided into Control group, CLP group, CLP + miR-NC group, CLP + miR-126 group and CLP + miR-126 + NF-κB pathway agonist (PMA) group. MiR-126 expressed in the brain tissue of CLP rats was down-regulated by qRT-PCR. Upregulation of miR-126 in CLP rats could improve brain injury and BBB marker protein level, reduce brain water content, Evans blue extravasation, inflammation, and excessive oxidative stress. This could also result in an inhibition of NF-κB signaling pathway activity. In conclusion, miR-126 overexpression can prevent brain injury caused by BBB damage via the inhibition of NF-κB signaling pathway activity.

Downregulation of lncRNA NEAT1 Ameliorates LPS-Induced Inflammatory Responses by Promoting Macrophage M2 Polarization via miR-125a-5p/TRAF6/TAK1 Axis

The lncRNA nuclear enriched abundant transcript 1 (NEAT1) promotes sepsis-inflammatory responses and acute kidney injury (AKI), but little known about the underlying mechanisms. This study aims to investigate the roles of NEAT1 in regulating macrophage polarization and its potential for alleviating inflammatory responses during sepsis pathogenesis. Mouse RAW264.7 macrophages were treated with lipopolysaccharide (LPS) as a cellular inflammatory model. NEAT1 shRNA, miR-125a-5p mimics, and TRAF6-overexpressing vector were used to transfect RAW264.7 cells. NEAT1, miR-125a-5p, and mRNA levels of functional genes were detected by quantitative RT-PCR. Protein abundances were analyzed by western blotting. Macrophage polarization was evaluated by flow cytometry. The bindings of miR-125a-5p with NEAT1 or TRAF6 gene were validated by dual luciferase reporter assay. LPS treatment promoted NEAT1 and suppressed miR-125a-5p expression in mouse macrophage cells. NEAT1 silencing by shRNAs promoted macrophage M2 polarization under LPS treatment, which upregulated miR-125a-5p expression, repressed TRAF6 expression and TAK1 protein phosphorylation in macrophages. These cellular and molecular changes induced by NEAT1 shRNAs were abrogated by miR-125a-5p inhibitors. Moreover, miR-125a-5p mimics suppressed TRAF6 expression and TAK1 protein phosphorylation in LPS-treated macrophages, thus causing macrophage M2 polarization under LPS treatment. TRAF6 overexpression abrogated the miR-125a-5p mimics-induced macrophage M2 polarization. miR-125a-5p could directly bind to NEAT1 or TRAF6 gene in macrophages. lncRNA NEAT1 knockdown ameliorates LPS-induced inflammation by promoting macrophage M2 polarization via miR-125a-5p/TRAF6/TAK1 axis.

LncRNA PVT1 accelerates LPS-induced septic acute kidney injury through targeting miR-17-5p and regulating NF-κB pathway

BACKGROUND

Long noncoding RNA PVT1 is associated with diverse human diseases, including acute kidney injury (AKI). However, our understandings of PVT1 on septic AKI are limited.

METHODS

The septic AKI model was constructed through lipopolysaccharide (LPS) treatment. PVT1 and miR-17-5p levels were measured using qRT-PCR analysis. The concentrations of inflammatory cytokines were determined with ELISA kits. Cell viability and apoptosis were assessed using CCK-8 assay and flow-cytometric analysis, respectively. Protein levels were examined using western blot assay. The targeting association between miR-17-5p and PVT1 was verified by dual-luciferase reporter, RIP and RNA pull-down assays.

RESULTS

PVT1 level was elevated and miR-17-5p level was declined in septic AKI patients' serum and LPS-stimulated HK-2 cells. Cell viability was suppressed and cell apoptosis and inflammation were promoted after LPS treatment. PVT1 knockdown or miR-17-5p elevation restored LPS-mediated HK-2 cell injury. MiR-17-5p was sponged by PVT1, and its inhibition weakened the impact of PVT1 deficiency on LPS-mediated injury of HK-2 cells. In addition, PVT1 knockdown inactivated NF-κB pathway mediated by LPS treatment, but miR-17-5p inhibition further reversed this effect.

CONCLUSION

PVT1 knockdown promoted cell viability, suppressed inflammatory response and apoptosis by regulating miR-17-5p expression and NF-κB pathway in LPS-stimulated HK-2 cells.

Non-Coding RNAs in Kidney Diseases: The Long and Short of Them

Recent progress in genomic research has highlighted the genome to be much more transcribed than expected. The formerly so-called junk DNA encodes a miscellaneous group of largely unknown RNA transcripts, which contain the long non-coding RNAs (lncRNAs) family. lncRNAs are instrumental in gene regulation. Moreover, understanding their biological roles in the physiopathology of many diseases, including renal, is a new challenge. lncRNAs regulate the effects of microRNAs (miRNA) on mRNA expression. Understanding the complex crosstalk between lncRNA–miRNA–mRNA is one of the main challenges of modern molecular biology. This review aims to summarize the role of lncRNA on kidney diseases, the molecular mechanisms involved, and their function as emerging prognostic biomarkers for both acute and chronic kidney diseases. Finally, we will also outline new therapeutic opportunities to diminish renal injury by targeting lncRNA with antisense oligonucleotides.

Linc-KIAA1737-2 promoted LPS-induced HK-2 cell apoptosis by regulating miR-27a-3p/TLR4/NF-κB axis

Inflammation and renal cell apoptosis participate in sepsis-induced acute kidney injury. Previous research found the upregulation of long non-coding RNA Linc-KIAA1737–2 in hypoxia- or inflammation-challenged human proximal tubular epithelial cells, but its role in sepsis-induced acute kidney injury is underexplored. In this research, we found that Linc-KIAA1737–2 could be upregulated in HK-2 human proximal tubular epithelial cells by LPS treatment, and knock-down of this lncRNA significantly attenuated LPS-induced apoptosis in HK-2 cells, while its overexpression showed opposite effect. MiR-27a-3p was confirmed to interact with Linc-KIAA1737–2 in HK-2 cells by RNA pull-down and dual-luciferase assay. MiR-27a-3p mimic transfection significantly attenuated LPS-induced HK-2 cell apoptosis by downregulating the protein levels of TLR4 and NF-κB, which was overturned by overexpression of Linc-KIAA1737–2. Our results suggested that Linc-KIAA1737–2 could promote LPS-induced apoptosis in HK-2 cells, and presumably sepsis-induced acute kidney injury, by regulating the miR-27a-3p/TLR4/NF-κB axis.

LncRNA NEAT1 Knockdown Alleviates Lipopolysaccharide-Induced Acute Lung Injury by Modulation of miR-182-5p/WISP1 Axis

Accumulating evidence has demonstrated the vital roles of long non-coding RNAs (lncRNAs) in acute lung injury (ALI). In this study, we aimed to explore the effect of Nuclear Paraspeckle Assembly Transcript 1 (NEAT1) on ALI development. The ALI mice and cell models were constructed using lipopolysaccharide (LPS)-induced method. The concentrations of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) were measured by enzyme-linked immunosorbent assay (ELISA). The levels of TNF-α mRNA, IL-6 mRNA, IL-1β mRNA, NEAT1, miR-182-5p, and WNT-inducible secreted protein 1 (WISP1) mRNA were determined by quantitative real-time polymerase chain reaction (qRT-PCR) assay. Cell viability was evaluated by Cell Counting Kit-8 (CCK-8) assay. The level of lactate dehydrogenase (LDH) and the activity of caspase-3 were measured by specific kits. The interaction between miR-182-5p and NEAT1 or WISP1 was investigated by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Protein levels were measured by Western blot assay. NEAT1 level was elevated in LPS-induced ALI mice and LPS-stimulated MH-S cells. LPS treatment repressed MH-S cell viability and promoted apoptosis and inflammation, while NEAT1 silencing restored the impacts. For mechanism analysis, NEAT1 was identified as the sponge for miR-182-5p to positively regulate WISP1 expression. Moreover, NEAT1 knockdown could accelerate cell viability and inhibit cell apoptosis and inflammation in LPS-induced MH-S cells by elevating miR-182-5p and decreasing WISP1 in LPS-exposed MH-S cells. In addition, NEAT1 deficiency blocked the activation of NF-κB pathway caused by LPS in MH-S cells. NEAT1 overexpression restrained cell viability and facilitated cell apoptosis and inflammation in LPS-exposed MH-S cells through miR-182-5p/WISP1 axis.

Reduced expression of MiR-125a-5p aggravates LPS-induced experimental acute kidney injury pathology by targeting TRAF6

AIMS

Patients with acute kidney injury (AKI) have higher mortality, and sepsis is among its main causes. MicroRNAs (miRNAs) are essential for regulating kidney function and could have curative potential. This study explored the possibility to treat AKI with miR-125a-5p and reveal the possible mechanism.

MATERIALS AND METHODS

LPS-induced mouse model and LPS-induced RAW264.7 cell model of AKI were established and treated with miR-125a-5p mimics or inhibitors. Serum creatinine and blood urea were measured to evaluate kidney function. The pathological changes of kidney tissues were detected by H&E and PAS staining technique, and the infiltration of macrophages were observed by immunohistochemistry. RAW264.7 cell viability, TRAF6 and cytokines expressions under LPS stimulation were measured. The role and therapeutic potential of miR-125a-5p were verified in vivo and in vitro after given miR-125a-5p mimics or inhibitors.

KEY FINDINGS

LPS-induced mice had increasing serum creatinine and urea, and evident pathological changes, including severe tubular dilatation and macrophages infiltration. TRAF6 expression in the kidney was significantly higher, while miR-125a-5p expression was suppressed. MiR-125a-5p targeted TRAF6, and its overexpression deactivated NF-κB signaling pathway, reducing downstream TNF-α, IL-1β and IL-6 expressions. MiR-125a-5p mimics rescued LPS-induced kidney damage and suppressed pro-inflammatory cytokines expression through inhibiting TRAF6/NF-κB axis.

SIGNIFICANCE

We highlighted that miR-125a-5p could inhibit LPS-induced acute inflammation in the kidney through targeting TRAF6/NF-κB axis. These results might contribute to the development of molecular therapy in AKI.