bims-lorfki Biomed News
on Long non-coding RNA functions in the kidney
Issue of 2020‒08‒02
five papers selected by
Nikita Dewani
Max Delbrück Centre for Molecular Medicine

  1. Front Oncol. 2020 ;10 705
    Qiu L, Ma Y, Yang Y, Ren X, Wang D, Jia X.
      Clear cell renal cell carcinoma (ccRCC) represents the most common type of renal cell carcinoma (RCC) in adults, in addition to the worst prognosis among the common epithelial kidney tumors. Inflammation and angiogenesis seem to potentiate tumor growth and metastasis of the malignancy. The current study explored the contributions of the lncRNA MCM3AP-AS1 in tumor-associated inflammation and angiogenesis in ccRCC with a specific focus on its transcriptional regulation and its interactions with transcription factor E2F1 and DPP4. Tumor tissues and matched adjacent non-tumor tissues were collected from 78 ccRCC patients. Methylation-specific PCR and ChIP assays were applied to detect the methylation at the promoter region of MCM3AP-AS1. Dual-luciferase reporter assay, RIP, RNA pull-down, and ChIP assays were employed to confirm the interactions between MCM3AP-AS1, E2F1, and DPP4. Nude mice were subcutaneously xenografted with human ccRCC cells. Cell proliferation was evaluated by CCK-8 assays and EDU staining in ccRCC cells in vitro and by immunohistochemical staining of Ki67 in vivo. Inflammation was examined by detecting the secretion of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6). Pro-angiogenic ability of ccRCC cells was assessed by the co-culture with human umbilical vein endothelial cells (HUVEC) in vitro and by microvessel density (MVD) measurements and angiogenesis in the chicken chorioallantoic membrane. MCM3AP-AS1 was highly-expressed in ccRCC and associated with poor patient survival. Demethylation of MCM3AP-AS1 was noted in ccRCC tissues and cells. Over-expression of MCM3AP-AS1 enhanced cell proliferation, the release of pro-inflammatory cytokines, and the tube formation of HUVECs in cultured human Caki-1 and 786-O cells. MCM3AP-AS1 was shown to enhance the E2F1 enrichment at the DPP4 promoter, to further increase the expression of DPP4. Knockdown of DPP4 could abate pro-angiogenic and pro-inflammatory abilities of MCM3AP-AS1 in ccRCC cells. Pro-angiogenic and pro-inflammatory abilities of MCM3AP-AS1 in vivo were confirmed in mice subcutaneously xenografted with human ccRCC cells. Our findings demonstrate a novel mechanism by which lncRNA MCM3AP-AS1 exerts pro-angiogenic and pro-inflammatory effects, highlighting the potential of MCM3AP-AS1 as a promising target for treating ccRCC.
    Keywords:  E2F transcription factor 1; MCM3AP-AS1; clear cell renal cell carcinoma; dipeptidyl peptidase-4; long non-coding RNA
  2. Aging (Albany NY). 2020 Jul 27. 12
    Liu Y, Gou X, Wei Z, Yu H, Zhou X, Li X.
      BACKGROUND: Papillary renal cell carcinoma (pRCC) was the 2nd most common subtype, accounting for approximately 15% incidence of renal cell carcinoma (RCC). Immune related long non-coding RNAs (IR-lncRs) plentiful in immune cells and immune microenvironment (IME) are potential in evaluating prognosis and assessing the effects of immunotherapy. A completed and meaningful IR-lncRs analysis based on abundant pRCC gene samples from The Cancer Genome Atlas (TCGA) will provide insight in this field.RESULTS: 17 IR-lncRs were selected by Pearson correlation analysis of immune score and the lncRNA expression level, and 5 sIRlncRs were significantly correlated with the OS of pRCC patients. 4 sIRlncRs (AP001267.3, AC026471.3, SNHG16 and ADAMTS9-AS1) with the most remarkable prognostic values were identified to establish the IRRS model and the OS of the low-risk group was longer than that in the high-risk group. The IRRS was certified as an independent prognosis factor and correlated with the OS. The high-risk group and low-risk group showed significantly different distributions and immune status through PCA and GSEA. In addition, we further found the expression levels of SNHG16 was remarkably enhanced in female patients with more advanced T-stages, but ADAMTS9-AS1 showed the opposite results.
    CONCLUSION: The IRRS model based on the identified 4 sIRlncRs showed the significant values on forecasting prognoses of pRCC patients, with the longer OS in the low-risk group.
    METHODS: We integrated the expression profiles of LncRNA and overall survival (OS) in the 322 pRCC patients based on the TCGA dataset. The immune scores calculated on account of the expression level of immune-related genes were used to verify the most relevant IR-lncRs. Survival-related IR-lncRs (sIRlncRs) were estimated by COX regression analysis in pRCC patients. The high-risk group and low-risk group were identified by the median immune-related risk score (IRRS) model established by the screened sIRlncRs. Functional annotation was displayed by gene set enrichment analysis (GSEA) and principal component analysis (PCA), and the immune composition and purity of the tumor were evaluated through microenvironment cell count records. The expression levels of sIRlncRs of pRCC samples were verified by real-time quantitative PCR.
    Keywords:  immune; long non-coding RNAs; papillary renal cell carcinoma; prognosis; risk score
  3. Med Sci Monit. 2020 Jul 29. 26 e921906
    Gao C, Zou X, Chen H, Shang R, Wang B.
      BACKGROUND Long non-coding RNAs (lncRNAs) play key roles in the development and progression of diseases, including sepsis. Therefore, this study aimed to clarify the role and underlying molecular mechanisms of lncRNA NEAT1 in sepsis. MATERIAL AND METHODS We used real-time quantitative polymerase chain reaction (RT-qPCR) to analyze the expression of lncRNA nuclear paraspeckle assembly transcript 1 (NEAT1), let-7b-5p, and tumor necrosis factor receptor-associated factor 6 (TRAF6). Western blot assay was used to measure the protein expression levels. After treatment with lipopolysaccharide (LPS), the biological behaviors of human renal tubular epithelial cells (HK-2), such as proliferation and apoptosis, were determined using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazol-3-ium bromide (MTT) and flow cytometry assays, respectively. The interaction relationship among NEAT1, TRAF6, and let-7b-5p was analyzed by the bioinformatics starBase database and dual-luciferase reporter assay. RESULTS lncRNA NEAT1 was expressed at higher levels in kidney tissues from sepsis patients than in healthy kidney tissues. Interestingly, LPS induced high expression of lncRNA NEAT1 in HK-2 cells in a time- and dose-dependent manner. Furthermore, silencing of NEAT1 weakened LPS-induced apoptosis, inflammation, and inhibition of proliferation, which was overturned by silencing of let-7b-5p. In addition, overexpression of TRAF6 abolished the overexpression of let-7b-5p-induced effects on apoptosis, inflammation, and growth of HK-2 cells exposed to LPS. In summary, NEAT1 regulated TRAF6 expression by sponging let-7b-5p in HK-2 cells, which promotes LPS-induced injury and inflammation in HK-2 cells. CONCLUSIONS Our data show that the lower expression of NEAT1 impeded sepsis development and LPS-induced injury inflammation by targeting let-7b-5p/TRAF6 axis, and NEAT1 may be a target for treatment of sepsis patients.
  4. J Cell Sci. 2020 Jul 31. pii: jcs.244020. [Epub ahead of print]
    Gong A, Zhao X, Pan Y, Qi Y, Li S, Huang Y, Guo Y, Qi X, Zheng W, Jia L.
      Long noncoding RNAs (lncRNAs) have emerged as important regulators of cancer progression. Abnormal sialylation leads to renal cell cancer (RCC) malignancy. However, the mechanism of lncRNA maternally expressed gene 3 (MEG3) mediates RCC progression by regulating ST3Gal1 transcription and EGFR sialylation is still unrevealed. Here, we found that the expression of MEG3 was higher in adjacent tissues than that in RCC tissues, as well as downregulated in RCC cell lines than that in normal renal cells. The proliferation, migration and invasion of RCC cell transfected with MEG3 were decreased, while the MEG3-knockdown cells showed the reversed results. The proliferative and metastatic ability in vivo were concordant to the behavior in vitro ST3Gal1 was dysregulated and positively correlated to MEG3. By applying bioinformatics, c-Jun was identified as a transcription factor of ST3Gal1, while altered MEG3 regulated c-Jun expression. Furthermore, ST3Gal1 modulated EGFR sialylation to inhibit EGFR phosphorylation, which affected the PI3K/AKT pathway activation. Taken together, our study provided a novel mechanism to elucidate the role of MEG3/ST3Gal1/EGFR axis in RCC progression.
    Keywords:  EGFR; MEG3; Renal cell carcinoma; ST3Gal1
  5. Kidney Blood Press Res. 2020 ;45(4): 589-602
    Zhan JF, Huang HW, Huang C, Hu LL, Xu WW.
      INTRODUCTION: Diabetic nephropathy (DN) is a serious complication of diabetes mellitus and is considered to be a sterile inflammatory disease. Increasing evidence suggest that pyroptosis and subsequent inflammatory response play a key role in the pathogenesis of DN. However, the underlying cellular and molecular mechanisms responsible for pyroptosis in DN are largely unknown.METHODS: The rat models of DN were successfully established by single 65 mg/kg streptozotocin treatment. Glomerular mesangial cells were exposed to 30 mmol/L high glucose media for 48 h to mimic the DN environment in vitro. Gene and protein expressions were determined by quantitative real-time PCR and Western blot. Cell viability and pyroptosis were measured by MTT assay and flow cytometry analysis, respectively. The relationship between lncRNA NEAT1, miR-34c, and Nod-like receptor protein-3 (NLRP3) was confirmed by luciferase reporter assay.
    RESULTS: We found that upregulation of NEAT1 was associated with the increase of pyroptosis in DN models. miR-34c, as a target gene of NEAT1, mediated the effect of NEAT1 on pyroptosis in DN by regulating the expression of NLRP3 as well as the expressions of caspase-1 and interleukin-1β. Either miR-34c inhibition or NLRP3 overexpression could reverse the accentuation of pyroptosis and inflammation by sh-NEAT1 transfection in the in vitro model of DN.
    CONCLUSIONS: Our findings suggested NEAT1 and its target gene miR-34c regulated cell pyroptosis via mediating NLRP3 in DN, providing new insights into understanding the molecular mechanisms of pyroptosis in the pathogenesis of DN.
    Keywords:  Inflammation; NEAT1; NLRP3; Pyroptosis; miR-34c