bims-lorfki Biomed News
on Long non-coding RNA functions in the kidney
Issue of 2020‒11‒15
four papers selected by
Nikita Dewani
Max Delbrück Centre for Molecular Medicine

  1. Life Sci. 2020 Nov 05. pii: S0024-3205(20)31481-8. [Epub ahead of print] 118728
      AIMS: Diabetic nephropathy (DN) is the most frequent complication of diabetes and causes millions of deaths each year. Finding novel therapy to DN is urgent, which requires a good understanding of the pathogenesis. Aims are to investigate the molecular mechanisms of DN by focusing on ANRIL/miR-497/TXNIP axis.MAIN METHODS: Kidney tissues were collected from diagnosed DN patients. High glucose (HG) treatment of human renal tubular epithelial cell cells (HK-2) was used as the cell model of DN. qRT-PCR and Western blotting were performed to measure levels of ANRIL, miR-497, TXNIP, IL-1β, IL-18, caspase-1, and NLRP3. LDH leakage and cell viability were determined with commercial LDH activity kit and MTT assay. ELISA was employed to examine secreted IL-1β and IL-18 levels. Flow cytometry was used to examine caspase-1 activity. Dual luciferase assay was performed to validate interactions of ANRIL/miR-497 and miR-497/TXNIP.
    KEY FINDINGS: ANRIL and TXNIP were elevated in DN kidney tissues and HG-treated HK-2 cells while miR-497 was reduced. ANRIL bound miR-497 while miR-497 directly targeted TXNIP. Knockdown of ANRIL suppressed HG-induced LDH leakage, TXNIP/NLRP3/caspase-1 activation, and increases of IL-1β and IL-18 secreted levels. miR-497 knockdown or TXNIP overexpression reversed the effects of ANRIL knockdown on LDH leakage and pyroptosis-related signaling. miR-497 mimics inhibited caspase-1-dependent pyroptosis while co-overexpression of TXNIP blocked its effects in HG-treated HK-2 cells.
    SIGNIFICANCE: ANRIL promotes pyroptosis and kidney injury in DN via acting as miR-497 sponge to disinhibit TXNIP expression. These results shed light on the mechanisms of DN and provide targets for therapy development.
    Keywords:  ANRIL; Diabetic nephropathy; Pyroptosis; TXNIP; miR-497
  2. Biosci Rep. 2020 Nov 27. pii: BSR20200212. [Epub ahead of print]40(11):
      BACKGROUND: Renal cell carcinoma (RCC) is a common malignant tumor that seriously endangers people's health. In recent years, long non-coding RNAs (lncRNAs) have been discovered to play vital roles in diverse cancers, including RCC. LncRNA lysyl oxidase like 1 antisense RNA 1 (LOXL1-AS1) has been found to exert carcinogenic functions in several cancers, but its role and mechanism in RCC have not been investigated.METHODS: qRT-PCR was utilized for testing RNA expression and Western blot for protein expression in RCC tissues or cells. Then, we assessed cell function by conducting a series of functional experiments, such as 5-ethynyl-2'-deoxyuridine staining, colony formation, flow cytometry, JC-1, Western blot and transwell migration experiments. Following, RNA immunoprecipitation, pull down and luciferase reporter experiments were carried out to explore the regulatory mechanisms of LOXL1-AS1 in RCC.
    RESULTS: LOXL1-AS1 was highly expressed in RCC tissues and cells. Moreover, knockdown of LOXL1-AS1 hampered RCC cell proliferation and migration. Importantly, miR-589-5p that was lowly expressed and worked as a tumor-inhibitor in RCC was found to bind with LOXL1-AS1. Furthermore, chromobox 5 (CBX5) targeted by miR-589-5p could expedite cell proliferation and migration in RCC. Finally, overexpressed CBX5 or inhibited miR-589-5p reversed the repressive impacts of silenced LOXL1-AS1 on RCC malignant phenotypes.
    CONCLUSIONS: LncRNA LOXL1-AS1 sequestered miR-589-5p to augment CBX5 expression in RCC cells, opening a new way for potential development in RCC treatment.
    Keywords:  CBX5; LOXL1-AS1; miR-589-5p; renal cell carcinoma
  3. Front Genet. 2020 ;11 562967
      Clear cell renal cell carcinoma (ccRCC) is the most common subtype of RCC. Compelling evidence has highlighted the crucial role of long non-coding RNA (lncRNA) in ccRCC. Our current study aims to explore the regulatory mechanism of LINC01094 in the development of ccRCC. Dual-luciferase reporter experiment verified the targeting relationship among miR-184, LINC01094, and SLC2A3. Furthermore, the interaction between LINC01094 and miR-184 was confirmed by RNA immunoprecipitation (RIP) and RNA pull-down. Biological behaviors of ccRCC cells were investigated through cell counting kit-8 (CCK8), scratch test, Transwell, and flow cytometry. The effect of SLC2A3 on the tumorigenicity of nude mice was evaluated in vivo. In ccRCC cells and clinical tissues, LINC01094 and SLC2A3 were highly expressed while miR-184 was lowly expressed. Besides, miR-184 was verified to be a direct target of LINC01094. Silencing LINC01094, up-regulating miR-184, or reducing SLC2A3 inhibited the growth, migration, and invasion of ccRCC cells. Tumor growth was suppressed by silenced LINC01215 via reducing the expression of SLC2A3 via miR-184. Taken together, silencing LINC01094 inhibited SLC2A3 expression by up-regulating miR-184, thereby inhibiting the development of ccRCC.
    Keywords:  LINC01094; clear cell renal cell carcinoma; long non-coding RNA; microRNA-184; solute carrier family 2 facilitated glucose transporter member 1
  4. Int Immunopharmacol. 2020 Nov;pii: S1567-5769(20)31727-6. [Epub ahead of print]88 106965
      BACKGROUND: We aimed to study the effects and the underlying mechanisms of Diosmetin (DIOS) in rats with sepsis-induced acute kidney injury (AKI).METHODS: The AKI model in RMCs was induced using LPS, and the cells were then treated with DIOS. Cell viability, apoptosis, inflammatory response, and antioxidant were measured using MTT, Flow cytometry, ELISA, and Lucigenin assay, respectively. The correlation between TUG1 and Nrf2 was confirmed by RNA pull-down and RNA immunoprecipitation. Real-time quantitative PCR and Western blot were performed to detect the expressions of gene and proteins during the development of AKI. The effects of lncRNA-TUG1 silencing and Nrf2 silencing on cell physiological functions were detected. Moreover, a rat sepsis-induced AKI model followed by Hematoxylin & Eosin (H&E) and immunofluorescence staining were performed.
    RESULTS: The experimental concentration of DIOS was determined to be 20 μM. After LPS treatment, the activity of RMCs was decreased, the apoptosis rate, inflammation and oxidative stress damage were increased, moreover, the expression of Nrf2/HO-1 signal axis was inhibited and caspase-3 was activated. However, DIOS significantly reversed these effects caused by LPS treatment, and increased the expression of lncRNA-TUG1, but lncRNA-TUG1 silencing effectively reversed the effects of DIOS. In addition, lncRNA-TUG1 was found to interact with Nrf2. Overexpression of TUG1 could reduce the damage of LPS caused to cell physiological functions, which were reversed by siNrf2. Thus, DIOS treatment could improve the physiological and pathological damages of renal tissues in AKI rats.
    CONCLUSION: DIOS may reduce sepsis-induced AKI through enhancing the TUG1/Nrf2/HO-1 pathway.
    Keywords:  Acute kidney injury; Diosmetin; Nrf2; Sepsis; lncRNA-TUG1