MiR-222-3p Promotes Cell Proliferation and Inhibits Apoptosis by Targeting PUMA (BBC3) in Non-Small Cell Lung Cancer

Exosomal hsa-miR-151a-3p and hsa-miR-877-5p are potential novel biomarkers for predicting bone metastasis in lung cancer

Exosomal miRNAs (exo-miRNAs) have arisen as novel diagnostic biomarkers for various cancers. However, few reports on exo-miRNAs related to bone metastasis (BM) in lung cancer exist. This study aims to screen out key exo-miRNAs and estimate their prognostic values for predicting BM in lung cancer. The differentially expressed exo-miRNAs between the highly-metastatic (95D) and lowly-metastatic (A549) human lung cancer cell lines were comprehensively analyzed using high-throughput sequencing followed by bioinformatic analyses. 29 candidate exo-miRNAs were identified, and 101 BM-related target genes were predicted. Enrichment analysis revealed that these target genes were mainly involved in regulating transcription and pathways in cancer. An exosomal miRNA-mRNA regulatory network consisting of 7 key miRNAs and 10 hub genes was constructed. Further function analysis indicated that these 10 hub genes were mainly enriched in regulating cancer's apoptosis and central carbon metabolism. The survival analysis indicated that 7 of 10 hub genes were closely related to prognosis. Mutation analysis showed that lung cancer patients presented certain genetic alterations in the 7 real hub genes. GSEA for a single hub gene suggested that 6 of 7 real hub genes had close associations with lung cancer development. Finally, ROC analysis revealed that hsa-miR-151a-3p and hsa-miR-877-5p provided high diagnostic accuracy in discriminating patients with bone metastasis (BM+) from patients without bone metastasis (BM-). These findings provided a comprehensive analysis of exo-miRNAs and target genes in the regulatory network of BM in lung cancer. In particular, hsa-miR-151a-3p and hsa-miR-877-5p may be novel biomarkers for predicting BM in lung cancer.

Maternal MicroRNA Profile Changes When LH Is Added to the Ovarian Stimulation Protocol: A Pilot Study

While the use of follicle-stimulating hormone (FSH) in ovarian stimulation for in vitro fertilization (IVF) is an established practice, the use of luteinizing hormone (LH) remains debatable. MicroRNAs (miRNAs) are short, endogenous, non-coding transcripts that control a variety of cellular functions, such as gonadotrophin production and follicular development. The goal of this pilot study was to investigate whether the employment of recombinant LH (rLH) in ovarian stimulation protocols results in changes in the miRNA profiles in human oocytes. Patients were divided into two groups: seven received recombinant FSH (rFSH, 225 IU), and six received rFSH (150 IU) plus rLH (75 IU). MiRNA predesigned panels and real-time PCR technology were used to analyze the oocytes retrieved from the follicular ovarian retrieval. Among the miRNAs evaluated, a series of them evidenced upregulation or downregulation in their expression in the FSH plus LH group compared to the FSH group. Considering the results obtained from the functional and network analysis, the different maternal miRNA profiles in the two groups revealed a differential modulation of pathways involved in numerous biological functions. Overall, based on the pathways associated with most of these maternal miRNAs, the presence of LH may result in a different modulation of pathways regulating survival under the control of a Tp53-related mechanism. Interestingly, among the miRNAs differentially expressed in oocytes of the two groups, we have found miRNAs already investigated at ovarian, follicular, oocyte, and embryonic levels: hsa-miR-484, hsa-miR-222, hsa-miR-520d-5p, hsa-miRNA-17, hsa-miR-548, and hsa-miR-140. Thus, investigation into the role of these miRNAs in oocyte molecular pathways may help determine how LH affects oocyte competence and eventually leads to the clinical improvement of IVF.

Dynamic Changes in miRNA Expression during the Generation of Expanded and Activated NK Cells

Therapies based on allogenic Natural Killer (NK) cells are becoming increasingly relevant, and our laboratory has produced expanded and activated NK (eNK) cells that are highly cytotoxic against several hematological cancers when used alone or in combination with currently approved therapeutic monoclonal antibodies. In order to produce eNK cells, healthy human donor NK cells undergo a 20-day expansion protocol with IL-2, IL-15 and Epstein-Barr virus (EBV)-transformed lymphoblastoid feeder cells. In order to produce an even more potent eNK-based therapy, we must elucidate the changes our protocol produces within healthy NK cells. To understand the post-transcriptional changes responsible for the increased cytolytic abilities of eNK cells, we performed microRNA (miRNA) expression analysis on purified NK cells from day 0 and day 20 of the protocol using quantitative reverse transcription PCR (RT-qPCR). Of the 384 miRNAs profiled, we observed changes in the expression of 64 miRNAs, with especially significant changes in 7 of them. The up-regulated miRNAs of note were miRs-146a, -124, -34a, and -10a, which are key in the regulation of cell survival through the modulation of pro-apoptotic genes such as PUMA. The down-regulation of miRs-199a, -223, and -340 was also detected and is associated with the promotion of NK cell cytotoxicity. We validated our analysis using immunoblot and flow cytometry studies on specific downstream targets of both up- and down-regulated miRNAs such as PUMA and Granzyme B. These results corroborate the functional importance of the described miRNA expression patterns and show the wide variety of changes that occur in eNK cells at day 20.

miR‑222-3p reduces neuronal cell apoptosis and alleviates spinal cord injury by inhibiting Bbc3 and Bim

Spinal cord injury (SCI) is a severe traumatic event, but without any established effective treatment because of the irreversible neuronal death. Here, we investigated the role of miR-222-3p in neuronal apoptosis following SCI. Rat SCI models and neuron hypoxia models were accordingly established. The Bbc3, Bim, Bcl-2, Bax, cleaved-caspase 3, cleaved-caspase 9, Cytochrome c, and miR-222-3p expression levels were examined by Western blotting and real-time reverse transcription polymerase chain reaction (RT-qPCR). The possible association between miR-222-3p and Bbc3/Bim was analyzed by dual-luciferase assay. The neuron viability was assessed by Cell Counting Kit-8 assay and Nissl's staining. Live cell staining was performed to detect the mitochondrial membrane potential and neuronal apoptosis. Rat locomotor function was assessed using the Basso-Beattie-Bresnahan scores. Cytochrome c was outflowed from the mitochondria after SCI or hypoxia treatment, and Bbc3, Bim, Bax, cleaved-caspase 9, and cleaved-caspase 3 were significantly upregulated, while Bcl-2 and miR-222-3p were decreased remarkably. Meanwhile, neuronal cell viability was significantly inhibited. Treatment of miR-222-3p significantly suppressed the Cytochrome c efflux and neuronal apoptosis and improved neuronal cell viability and motor function in SCI rats. Moreover, we found that Bbc3 and Bim were the direct targets of miR-222-3p. Overall, our data suggest that miR-222-3p could alleviate the mitochondrial pathway-mediated apoptosis and motor dysfunction in rats after SCI by targeting Bbc3 and Bim.

Circulating plasma miR222-3P status and its potential diagnostic performance in prostate cancer

BACKGROUND

Although studies suggest that miR222-3p is dysregulated in prostate cancer (PC) cells and tissues, the possible changes in the level of miR222-3p in the plasma samples of PC patients remained unclear. The present study aimed to evaluate the diagnostic value of the plasma miR222-3p expression level as a potential biomarker in PC, benign prostatic hyperplasia (BPH) and healthy people.

METHODS

Blood samples were collected from 100 adult males (54 patients with PC, 27 patients with BPH and 19 healthy individuals) referred to our affiliated hospital. The expression level of miR222-3p was evaluated using a quantitative reverse transcription-polymerase chain reaction. Receiver operating characteristic curves were used to evaluate miR222-3p diagnostic accuracy for discriminating between the PC, BPH and healthy individuals.

RESULTS

The expression level of miR222-3p was significantly higher in PC patients compared to healthy individuals as a fold change of 5.3 (p = 0.009), but not for BPH individuals. The diagnostic value of the plasma miR222-3p for discrimination of the PC patients from healthy individuals was reasonable [cut-off value (fold change relative to miR16-5p) = 1.69, area under the curve = 0.73, sensitivity = 0.75 and specificity = 0.74].

CONCLUSIONS

Circulating plasma miR-222-3p significantly upregulated in PC patients, but not in BPH ones. Besides these preliminary results showed that miR222-3p has the potential to discriminate PC patients from healthy ones. Addittional studies with a larger sample size are required to confirm these data.

miR-100-5p Promotes Epidermal Stem Cell Proliferation through Targeting MTMR3 to Activate PIP3/AKT and ERK Signaling Pathways

Skin epidermal stem cells (EpSCs) play a critical role in wound healing and are ideal seed cells for skin tissue engineering. Exosomes from human adipose-derived stem cells (ADSC-Exos) promote human EpSC proliferation, but the underlying mechanism remains unclear. Here, we investigated the effect of miR-100-5p, one of the most abundant miRNAs in ADSC-Exos, on the proliferation of human EpSCs and explored the mechanisms involved. MTT and BrdU incorporation assays showed that miR-100-5p mimic transfection promoted EpSC proliferation in a time-dependent manner. Cell cycle analysis showed that miR-100-5p mimic transfection significantly decreased the percentage of cells in the G1 phase and increased the percentage of cells in the G2/M phase. Myotubularin-related protein 3 (MTMR3), a lipid phosphatase, was identified as a direct target of miR-100-5p. Knockdown of MTMR3 in EpSCs by RNA interference significantly enhanced cell proliferation, decreased the percentage of cells in the G1 phase and increased the percentage of cells in the S phase. Overexpression of MTMR3 reversed the proproliferative effect of miR-100-5p on EpSCs, indicating that miR-100-5p promoted EpSC proliferation by downregulating MTMR3. Mechanistic studies showed that transfection of EpSCs with miR-100-5p mimics elevated the intracellular PIP3 level, induced AKT and ERK phosphorylation, and upregulated cyclin D1, E1, and A2 expression, which could be attenuated by MTMR3 overexpression. Consistently, intradermal injection of ADSC-Exos or miR-100-5p-enriched ADSC-Exos into cultured human skin tissues significantly reduced MTMR3 expression and increased the thickness of the epidermis and the number of EpSCs in the basal layer of the epidermis. The aforementioned effect of miR-100-5p-enriched ADSC-Exos was stronger than that of ADSC-Exos and was reversed by MTMR3 overexpression. Collectively, our findings indicate that miR-100-5p promotes EpSC proliferation through MTMR3-mediated elevation of PIP3 and activation of AKT and ERK. miR-100-5p-enriched ADSC-Exos can be used to treat skin wound and expand EpSCs for generating epidermal autografts and engineered skin equivalents.

Enhancer of zeste homolog 2 exerts functions in gastric cancer development via modulating microRNA-222-3p methylation and WEE1 expression

OBJECTIVE

Enhancer of zeste homolog 2 (EZH2) has been studied in gastric cancer (GC), while the role of EZH2 in GC via binding to microRNA (miR)-222-3p remains obscure. This research aims to unravel the regulatory mechanism of EZH2 in GC progression via the modulation of miR-222-3p/WEE1 axis.

METHODS

Initially, EZH2, miR-222-3p and WEE1 levels in GC cells and tissues were examined. Thereafter, vectors altering EZH2, miR-222-3p or WEE1 expression were transfected into GC cells to determine the malignant behaviors involved in tumorigenesis of GC cells. Finally, the targeting relations among EZH2, miR-222-3p and WEE1 were validated.

RESULTS

EZH2 and WEE1 were up-regulated while miR-222-3p was down-regulated in GC tissues and cells. The decreased EZH2, silenced WEE1, or restored miR-222-3p constrained the malignant behaviors involved in tumorigenesis of GC cells. Deletion of miR-222-3p could reverse the effect of silenced EZH2 on suppressing the biological functions of GC cells. EZH2 could bind to the promoter of miR-222-3p, and there was a targeting relationship between miR-222-3p and WEE1.

CONCLUSION

Our study demonstrates that EZH2 promotes GC development via the modulation of miR-222-3p/WEE1 axis, thus providing promising therapeutic targets for GC therapy.

Cinobufagin induces FOXO1-regulated apoptosis, proliferation, migration, and invasion by inhibiting G9a in non-small-cell lung cancer A549 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Bufonis (VB), an animal drug called Chansu in China, is the product of the secretion of Bufo gargarizans Cantor or B. melanostictus Schneider. As a traditional Chinese medicine (TCM) for a long time, it has been widely used in the treatment of heart failure, ulcer, pain, and various cancers. Cinobufaginn (CNB), the cardiotonic steroid or bufalene lactone extracted from VB, has the effects of detoxification, detumescence, and analgesia.

AIM OF THE STUDY

The present study aimed to define the effects of CNB on non-small-cell lung cancer (NSCLC) and identify the potential molecular mechanisms.

MATERIALS AND METHODS

A549 cells were treated with cinobufagin and cell viability, apoptosis, migration, and invasion were then evaluated using Cell Counting Kit-8 (CCK8) assays, flow cytometry, and Transwell assays, respectively. Moreover, the levels of proliferating cell nuclear antigen (PCNA), cytokeratin8 (CK8), poly ADP-ribose polymerase (PARP), Caspase3, Caspase8, B-cell lymphoma/lewkmia-2(Bcl-2), Bcl2-Associated X(Bax), forkhead box O1 (FOXO1), and euchromatic histone-lysine N-methyltransferase2 (G9a, EHMT2) in A549 cells were evaluated using qRT-PCR and/or Western blot analysis (WB), Co-IP, immunofluorescence, and immunohistochemistry. An in vivo imaging system, TUNEL, Immunofluorescence, and immunohistochemistry were also used to detect proliferating cell nuclear antigen(PCNA), Ki67, E-Cadherin(E-Cad), FOXO1, and G9a in mouse xenograft model experiments.

RESULTS

CNB suppressed cell proliferation, migration, and invasion but promoted apoptosis in A549 cells in a dose- and time-dependent manner, while cinobufagin had no cytotoxic effect on BEAS-2B cells. In vivo, cinobufagin inhibited the proliferation, migration, and invasion of A549 cells and promoted their apoptosis. The occurrence of the above phenomena was accompanied by an increase in FOXO1 expression and a decrease in G9a expression. In A549 cells, CNB did not reverse the changes in the proliferation, migration, invasion, and apoptosis of A549 cells after FOXO1 was successfully silenced.

CONCLUSION

Our study provides the first evidence that cinobufagin suppresses the malignant biological behaviours of NSCLC cells in vivo and in vitro and suggests that mechanistically, this effect may be achieved by inhibiting the expression of the histone methyltransferase G9a and activating the tumour suppressor gene FOXO1. Taken together, our findings provide important insights into the molecular mechanism underlying cinobufagin's anticancer activity, and suggest that cinobufagin could be a candidate for targeted cancer therapy.

Curcumin Inhibits the Growth and Metastasis of Melanoma via miR-222-3p/SOX10/Notch Axis

Background

The aim of this study was to investigate the effect of curcumin on melanoma and its mechanism.

Methods

Curcumin (0, 0.125, 0.25, or 0.5 mg/ml) was utilized to treat A375 and HT144 cell lines. The MTT analysis was used to confirm the proliferation ability. Wound healing and transwell analysis showed the migration and invasion ability. Immunofluorescence assay was used to demonstrate the effect of curcumin on SOX10 expression. Multiple bioinformatic analysis to confirm the SOX10 associated miRNA. The correlation of miR-222-3p and SOX10 was detected by Luciferase reporter assays. qRT-PCR showed the miR-222-3p level. Western blot analyzed the expression of SOX10, Notch1, and HES1 in melanoma cell treated with or without miR-222-3p inhibitor.

Results

Curcumin could inhibit the proliferation, migration, and invasion of melanoma cells. Furthermore, curcumin repress the expression of SOX10, Notch1, and HES-1, and increase the expression of miR-222-3p. And the miR-222-3p could directly target to SOX10 mRNA to inhibit its expression. In addition, inhibition of miR-222-3p expression reversed the inhibitory effect of curcumin the growth of melanoma cells.

Conclusion

Curcumin enhances the miR-222-3p level to reduce SOX10 expression, and ultimately inactivates the Notch pathway in repressing melanoma proliferation, migration, and invasion.

MicroRNA-Based Risk Score for Predicting Tumor Progression Following Radioactive Iodine Ablation in Well-Differentiated Thyroid Cancer Patients: A Propensity-Score Matched Analysis

Simple Summary

The three-tiered American Thyroid Association (ATA) risk stratification helps clinicians tailor decisions regarding follow-up modalities and the need for postoperative radioactive iodine (RAI) ablation and radiotherapy. However, a significant number of well-differentiated thyroid cancers (DTC) progress after treatment. Current follow-up modalities have also been proposed to detect disease relapse and recurrence but have failed to be sufficiently sensitive or specific to detect, monitor, or determine progression. Therefore, we assessed the predictive accuracy of the microRNA-based risk score in DTC with and without postoperative RAI. We confirm the prognostic role of triad biomarkers (miR-2f04, miR-221, and miR-222) with higher sensitivity and specificity for predicting disease progression than the ATA risk score. Compared to indolent tumors, a higher risk score was found in progressive samples and was associated with shorter survival. Consequently, our prognostic microRNA signature and nomogram provide a clinically practical and reliable ancillary measure to determine the prognosis of DTC patients.

Abstract

To identify molecular markers that can accurately predict aggressive tumor behavior at the time of surgery, a propensity-matching score analysis of archived specimens yielded two similar datasets of DTC patients (with and without RAI). Bioinformatically selected microRNAs were quantified by qRT-PCR. The risk score was generated using Cox regression and assessed using ROC, C-statistic, and Brier-score. A predictive Bayesian nomogram was established. External validation was performed, and causal network analysis was generated. Within the eight-year follow-up period, progression was reported in 51.5% of cases; of these, 48.6% had the T1a/b stage. Analysis showed upregulation of miR-221-3p and miR-222-3p and downregulation of miR-204-5p in 68 paired cancer tissues (p < 0.001). These three miRNAs were not differentially expressed in RAI and non-RAI groups. The ATA risk score showed poor discriminative ability (AUC = 0.518, p = 0.80). In contrast, the microRNA-based risk score showed high accuracy in predicting tumor progression in the whole cohorts (median = 1.87 vs. 0.39, AUC = 0.944) and RAI group (2.23 vs. 0.37, AUC = 0.979) at the cutoff >0.86 (92.6% accuracy, 88.6% sensitivity, 97% specificity) in the whole cohorts (C-statistics = 0.943/Brier = 0.083) and RAI subgroup (C-statistic = 0.978/Brier = 0.049). The high-score group had a three-fold increased progression risk (hazard ratio = 2.71, 95%CI = 1.86–3.96, p < 0.001) and shorter survival times (17.3 vs. 70.79 months, p < 0.001). Our prognostic microRNA signature and nomogram showed excellent predictive accuracy for progression-free survival in DTC.

The roles of microRNAs played in lung diseases via regulating cell apoptosis

MicroRNAs (miRNAs) are a type of endogenous non-coding short-chain RNA, which plays a crucial role in the regulation of many essential cellular functions, including cellular migration, proliferation, invasion, autophagy, oxidative stress, apoptosis, and differentiation. The lung can be damaged by pathogenic microorganisms, as well as physical or chemical factors. Research has confirmed that miRNAs and lung cell apoptosis can affect the development and progression of several lung diseases. This article reviews the role of miRNAs in the development of lung disease through regulating host cell apoptosis.

Inhibition of miR-185-3p Confers Erlotinib Resistance Through Upregulation of PFKL/MET in Lung Cancers

Erlotinib (ER), as an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), has a significant therapeutic effect in lung cancers. However, EGFR TKI resistance inevitably occurs after treatment for approximately 12 months, which weakens its antitumor effect. Here, we identified miR-185-3p as a significantly downregulated microRNA responsible for acquired EGFR TKI resistance in cells and patients with lung cancer. qRT-PCR and Western Blot were performed to determine the relative expression of miR-185-3p in ER-resistant tumor tissues and cells. The viability and apoptosis of lung cancer cells were evaluated by Cell Counting Kit-8 (CCK8) assay and flow cytometry, respectively. The binding between miR-185-3p and liver-type phosphofructokinase (PFKL) was verified by dual luciferase assay. It was found that overexpression of miR-185-3p conferred ER sensitivity in lung cancer cell lines. MiR-185-3p was downregulated in ER-resistant lung cancer cells (H1299/ER and A549/ER). MiR-185-3p inhibited proliferation and induced cell apoptosis in ER-resistant cells. Mechanistically, miR-185-3p downregulation contributed to ER resistance through upregulating the PFKL. Moreover, Mesenchymal to epithelial transition (MET) oncoprotein promoted EGFR-TKI resistance by regulating miR-185-3p and PFKL. These findings revealed a novel mechanism in which downregulation of miR-185-3p may induce overexpression of PFKL and MET and confer ER resistance in lung cells. Combination of PFKL/MET inhibitors and EGFR TKIs could be a rational therapeutic approach for lung cancer patients with EGFR mutation.

The Impact of lncRNAs and miRNAs on Apoptosis in Lung Cancer

Apoptosis is a coordinated cellular process that occurs in several physiological situations. Dysregulation of apoptosis has been documented in numerous pathological situations, particularly cancer. Non-coding RNAs regulate apoptosis via different mechanisms. Lung cancer is among neoplastic conditions in which the role of non-coding RNAs in the regulation of apoptosis has been investigated. Non-coding RNAs that regulate apoptosis in lung cancer have functional interactions with PI3K/Akt, PTEN, GSK-3β, NF-κB, Bcl-2, Bax, p53, mTOR and other important cancer-related pathways. Globally, over-expression of apoptosis-blocking non-coding RNAs has been associated with poor prognosis of patients, while apoptosis-promoting ones have the opposite effect. In the current paper, we describe the impact of lncRNAs and miRNAs on cell apoptosis in lung cancer.

MiR-222-3p induced by hepatitis B virus promotes the proliferation and inhibits apoptosis in hepatocellular carcinoma by upregulating THBS1

This study aimed to explore the role of miR-222-3p in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). MiR-222-3p expression in tumor tissues of HBV (+) or HBV (-) HCC patients and corresponding cell lines was detected by quantitative reverse transcription PCR (qRT-PCR). Cell proliferation was assessed by cell counting kit-8 (CCK-8) and colony formation assays. Cell apoptosis was evaluated by flow cytometry. The potential targets of miR-222-3p were predicted by Targetscan, and the binding relationship between miR-222-3p and thrombospondin-1 (THBS1) was determined by luciferase reporter assay and RNA immunoprecipitation (RIP) assay. MiR-222-3p was significantly upregulated in HCC tissues and cell lines and further elevated by HBV infection. MiR-222-3p downregulation effectively inhibited the proliferation and induced the apoptosis of HBV (-) HepG2 cells, HBV (+) HepG2.2.15 cells, Huh7-V cells, and Huh7-HBV cells. In addition, miR-222-3p overexpression enhanced the proliferation of these cell lines but exhibited no obvious effect on their apoptosis. Mechanistically, miR-222-3p was directly bound to the 3'-UTR of THBS1 and acted as its competing endogenous RNA (ceRNA). Interestingly, THBS1 silencing attenuated the inhibitory effect of miR-222-3p downregulation on the proliferation of these cell lines in vitro. Our results revealed that HBV infection further increased miR-222-3p expression and promoted HCC progression via miR-222-3p-mediated THBS1 downregulation. Our findings suggest that miR-222-3p might be a potential diagnostic and therapeutic target for HCC and HBV-related HCC.

LncRNA NEAT1 Promotes High Glucose-Induced Mesangial Cell Hypertrophy by Targeting miR-222-3p/CDKN1B Axis

Glomerular hypertrophy is an early morphological alteration in diabetic nephropathy. Cyclin-Dependent Kinases have been shown to be required for high glucose (HG)-induced hypertrophy; however, the upstream regulators of CDKN1B in glomerular hypertrophy remain unclear. Herein we describe a novel pathway in which Long noncoding RNA (lncRNA) NEAT1 regulates the progression of mesangial cell hypertrophy via a competing endogenous RNA (ceRNA) mechanism. Real-time PCR was performed to detect the relative NEAT1 and miR-222-3p expressions and further confirmed the relationship between NEAT1 and miR-222-3p. Cell cycle was evaluated by flow cytometry. The related mechanisms were explored by Western blot, RNA immunoprecipitation and chromatin immunoprecipitation assay. We show that NEAT1 forms double stranded RNA (dsRNA) with miR-222-3p, thus limiting miR-222-3p's binding with CDKN1B. This release of CDKN1B mRNA leads to elevated CDKN1B protein expression, resulting in hypertrophy. In addition, we demonstrated that STAT3 which is activated by HG induces the transcription of NEAT1 by binding to its promoter. Our findings underscore an unexpected role of lncRNAs on gene regulation and introduce a new mode of proliferation regulation in mesangial cells.

Knockdown of long non-coding RNA LEF1-AS1 attenuates apoptosis and inflammatory injury of microglia cells following spinal cord injury

BACKGROUND

Spinal cord injury (SCI) is associated with health burden both at personal and societal levels. Recent assessments on the role of lncRNAs in SCI regulation have matured. Therefore, to comprehensively explore the function of lncRNA LEF1-AS1 in SCI, there is an urgent need to understand its occurrence and development.

METHODS

Using in vitro experiments, we used lipopolysaccharide (LPS) to treat and establish the SCI model primarily on microglial cells. Gain- and loss of function assays of LEF1-AS1 and miR-222-5p were conducted. Cell viability and apoptosis of microglial cells were assessed via CCK8 assay and flow cytometry, respectively. Adult Sprague-Dawley (SD) rats were randomly divided into four groups: Control, SCI, sh-NC, and sh-LEF-AS1 groups. ELISA test was used to determine the expression of TNF-α and IL-6, whereas the protein level of apoptotic-related markers (Bcl-2, Bax, and cleaved caspase-3) was assessed using Western blot technique.

RESULTS

We revealed that LncRNA LEF1-AS1 was distinctly upregulated, whereas miR-222-5p was significantly downregulated in LPS-treated SCI and microglial cells. However, LEF1-AS1 knockdown enhanced cell viability, inhibited apoptosis, as well as inflammation of LPS-mediated microglial cells. On the contrary, miR-222-5p upregulation decreased cell viability, promoted apoptosis, and inflammation of microglial cells. Mechanistically, LEF1-AS1 served as a competitive endogenous RNA (ceRNA) by sponging miR-222-5p, targeting RAMP3. RAMP3 overexpression attenuated LEF1-AS1-mediated protective effects on LPS-mediated microglial cells from apoptosis and inflammation.

CONCLUSION

In summary, these findings ascertain that knockdown of LEF1-AS1 impedes SCI progression via the miR-222-5p/RAMP3 axis.