bims-lorfki Biomed News
on Long non-coding RNA functions in the kidney
Issue of 2021–07–11
five papers selected by
Nikita Dewani, Max Delbrück Centre for Molecular Medicine



  1. J Clin Lab Anal. 2021 Jul 09. e23881
       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.
    Keywords:  APOL1; acute kidney injury; inflammation; lncRNA MALAT1; miR-204
    DOI:  https://doi.org/10.1002/jcla.23881
  2. Mol Med. 2021 Jul 08. 27(1): 71
       BACKGROUND: Accumulating evidences have demonstrated that long non-coding RNAs (lncRNAs) are involved in the pathophysiology of diabetic nephropathy (DN). lncRNA SOX2OT plays an essential role in many diseases, including diabetes. Herein, we aim to investigate the underlying mechanism of lncRNA SOX2OT in DN pathogenesis.
    METHODS: Streptozotocin-induced DN mouse models and high glucose-induced mouse mesangial cells were constructed to examine the expression pattern of lncRNA SOX2OT. The activation of autophagy was evaluated using immunohistochemistry, immunofluorescence and western blot analysis, respectively. SOX2OT overexpressing plasmid was applied to further verify the functional role of SOX2OT in DN pathogenesis. CCK-8 and EDU assays were performed to the proliferation of mesangial cells. Additionally, rapamycin, the inhibitor of mTOR signaling, was used to further clarify whether SOX2OT controls DN development through Akt/mTOR pathway.
    RESULTS: lncRNA SOX2OT was markedly down-regulated both in streptozotocin-induced DN mice and high glucose-induced mouse mesangial cells. Moreover, overexpression of lncRNA SOX2OT was able to diminish the suppression of autophagy and alleviate DN-induced renal injury. Functionally, CCK-8 and EDU assays indicated that lncRNA SOX2OT overexpression significantly suppressed the proliferation and fibrosis of mesangial cells. Additionally, an obvious inhibition of Akt/mTOR was also observed with lncRNA SOX2OT overexpression, which was then further verified in vivo.
    CONCLUSION: In summary, we demonstrated that lncRNA SOX2OT alleviates the pathogenesis of DN via regulating Akt/mTOR-mediated autophagy, which may provide a novel target for DN therapy.
    Keywords:  Akt; Autophagy; Diabetic nephropathy; MTOR; SOX2OT
    DOI:  https://doi.org/10.1186/s10020-021-00310-6
  3. J Healthc Eng. 2021 ;2021 3533608
      Renal cell carcinoma (RCC) accounts for about 2% to 3% of adult malignancies, and clear cell renal cell carcinoma (ccRCC) is the most common and aggressive type of kidney cancer. It accounts for 75% of all kidney tumors. Although new targeted drugs continue to appear, they are still not suitable for all patients. Therefore, an in-depth study of the molecular mechanism of the development of ccRCC and exploration of new targets for the treatment of ccRCC will help to achieve precise treatment for ccRCC. With the development of molecular research, the study of long noncoding RNA (LncRNA) has given us a new understanding of tumors. Although LncRNA does not encode proteins, it directly interacts with proteins in various signaling pathways and affects cell functions. Therefore, it is of great significance to study the mechanism of LncRNA in ccRCC. The expression level of Linc00472 in ccRCC tissues is significantly lower than adjacent normal tissues, and its low expression is closely related to Furman's high grade. The low expression of Linc00472 is associated with poor prognosis in patients with ccRCC. The results of protein interaction and functional enrichment analysis indicate that genes upregulated in renal clear cell carcinoma may play a major role. Analysis of target gene prediction results showed that Linc00472 may be used as ceRNA in the miR-24-3p-HLA-DPB1 pathway, miR-24-3p-CXCL9 pathway, miR-221-3p-C3aR1-VEGFR2 pathway, miR-17-5p-HLA-DQA1/HLA-DQB1 pathway, and miR-17-5p-C3aR1/C5aR1-VEGFR2 pathway which play important functions. In addition, the regulatory relationship between miR-24-3p and TNFR2 (TNFRSF1B), CD36, and COL4A1 should also be noted. The value of Linc00472 in the diagnosis and treatment of ccRCC is worthy of further study.
    DOI:  https://doi.org/10.1155/2021/3533608
  4. Cell Death Dis. 2021 Jul 03. 12(7): 672
      Over the last decade, more than 10 independent SNPs have been discovered to be associated with the risk of renal cell carcinoma among different populations. However, the biological functions of them remain poorly understood. In this study, we performed eQTL analysis, ChIP-PCR, luciferase reporter assay, and Cox regression analysis to identify the functional role and underlying mechanism of rs67311347 in RCC. The ENCORI database, which contains the lncRNA-miRNA-mRNA interactions, was used to explore the possible target miRNA of ENTPD3-AS1. The results showed that the G > A mutation of rs67311347 created a binding motif of ZNF8 and subsequently upregulated ENTPD3-AS1 expression by acting as an enhancer. The TCGA-KIRC and our cohorts both confirmed the downregulation of ENTPD3-AS1 in RCC tissues and demonstrated that increased ENTPD3-AS1 expression was associated with good OS and PFS. Furthermore, ENTPD3-AS1 interacted with miR-155-5p and activated the expression of HIF-1α, which was an important tumor suppressor gene in the development of RCC. The functional experiments revealed that overexpression of ENTPD3-AS1 inhibited cell proliferation in RCC cell lines and the effect could be rescued by knocking down HIF-1α. Our findings reveal that SNP-mediated lncRNA-ENTPD3-AS1 upregulation suppresses renal cell carcinoma via miR-155/HIF-1α signaling.
    DOI:  https://doi.org/10.1038/s41419-021-03958-4
  5. Biomed Res Int. 2021 ;2021 5589101
       Aim: This study is aimed at constructing the competing endogenous RNA (ceRNA) network in chromophobe renal cell carcinoma (ChRCC).
    Methods: Clinical and RNA sequence profiles of patients with ChRCC, including messenger RNAs (mRNAs), microRNAs (miRNAs), and long noncoding RNAs (lncRNAs), were obtained from The Cancer Genome Atlas (TCGA) database. "edgeR" and "clusterProfiler" packages were utilized to obtain the expression matrices of differential RNAs (DERNAs) and to conduct gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Weighted gene coexpression network analysis (WGCNA) was performed to screen the highly related RNAs, and miRcode, StarBase, miRTarBase, miRDB, and TargetScan datasets were used to predict the connections between them. Univariate and multivariate Cox proportional hazards regressions were performed in turn to elucidate prognosis-related mRNAs in order to construct the ceRNA regulatory network.
    Results: A total of 1628 DElncRNAs, 104 DEmiRNAs, and 2619 DEmRNAs were identified. WGCNA showed significant correlation in 1534 DElncRNAs, 98 DEmiRNAs, and 2543 DEmRNAs, which were related to ChRCC. Fourteen DEmiRNAs, 113 DElncRNAs, and 43 DEmRNAs were screened. Nine mRNAs (ALPL, ARHGAP29, CADM2, KIT, KLRD1, MYBL1, PSD3, SFRP1, and SLC7A11) significantly contributed to the overall survival (OS) of patients with ChRCC (P < 0.05). Furthermore, two mRNAs (CADM2 and SFRP1) appeared to be independent risk factors for ChRCC.
    Conclusion: The findings revealed the molecular mechanism of ChRCC and potential therapeutic targets for the disease.
    DOI:  https://doi.org/10.1155/2021/5589101