Long noncoding RNA growth arrest-specific transcript 5 alleviates renal fibrosis in diabetic nephropathy by downregulating matrix metalloproteinase 9 through recruitment of enhancer of zeste homolog 2

Diabetic nephropathy (DN) is a frequently occurred microvascular complication associated with type I and type II diabetes mellitus. The participation of long noncoding RNAs (lncRNAs) in diabetes-related microvascular complications has been reported extensively. We attempted to unveil the possible regulatory mechanism of lncRNA growth arrest-specific transcript 5 (GAS5) and matrix metalloproteinase 9 (MMP9), an important inflammatory protein, in the progression of DN. A rat DN model was induced by streptozocin (STZ). The low expression of GAS5 and high expression of MMP9 in DN rats with DN was then determined by RT-qPCR and western blot analysis, and lentivirus-mediated GAS5 overexpression was shown to ameliorate STZ-induced renal interstitial fibrosis (RIF) and inflammatory reaction in the kidney of DN rats. Moreover, MMP9 was found to be upregulated in STZ-induced DN, while MMP9 silencing induced by lentivirus expressing shRNA against MMP9 reduced RIF and suppressed inflammation in the kidney of DN rats. RIP, RNA pull-down, and ChIP assays demonstrated that GAS5 downregulated MMP9 via recruiting enhancer of zeste homolog 2 (EZH2) in the promoter region of MMP9. Overall, our study reveals that GAS5 downregulates MMP9 expression through recruiting EZH2 to MMP9 promoter region and alleviates the progression of renal fibrosis in DN rats, which sheds new light on the therapeutic potential of GAS5-targeted therapies in combating that disease.

The relationships of genetic polymorphisms of the long noncoding RNA growth arrest-specific transcript 5 with uterine cervical cancer

The purposes of the investigation were to examine the implications of long noncoding RNA growth arrest-specific transcript 5 (GAS5) in progression and clinicopathological factors of uterine cervical cancer, and patient survival in Taiwan. Genotypic distributions of two GAS5 genetic variants rs145204276 and rs55829688 were detected in 208 patients including 111 patients with invasive cancer, 97 with precancerous lesions as well as 307 control women using real-time polymerase chain reaction. It explored that patients with cervical precancerous lesion had lower rate of AGGCA deletion (Del) in both alleles (Del/Del) of GAS5 rs145204276 as compared with control women. Patients with invasive cancer did not exhibit higher rate of Del/Del. Meanwhile, there were no different genotypic distributions in rs55829688 among patients with cervical invasive cancer and those with precancerous lesions as well as control women. Moreover, cervical cancer patients with Ins (insertion, AGGCA)/Del and Del/Del (-/-) in GAS5 rs55829688 tended to have poorer hazard ratio (HR) of 5 years survival. In addition, lymph node metastasis status exerted the most significantly predictive of 5 years survival rate. Conclusively, GAS5 polymorphism rs145204276 is probably applicable to predict 5 years survival HR of cervical cancer patients. However, the mechanism elucidating the methylation status and transcription function of rs145204276 in uterine cervical cancer needs to be delineated for its unique implication in uterine cervical cancer.