One functional variant in the 3′‐untranslated region of TLR4 is associated with the elevated risk of ventilator‐associated pneumonia in the patients with chronic obstructive pulmonary disease

Abstract

The aim of this study was to identify the association polymorphism (rs11536889) in the 3′‐untranslated region (3′‐UTR) of Toll‐like receptors 4 (TLR4) and the risk for ventilator‐associated pneumonia (VAP). miRNA database online and luciferase assays were used to validate TLR4 as the target gene of miR‐1236. Enzyme‐linked immunosorbent assay analysis and western blot were used to analyze the level of TLR4 in different genotype groups. In the present study, miR‐1236 was predicted to bind to the rs11536889 G allele rather than the rs11536889 C allele, which was further confirmed by the luciferase activity suppressed by a fragment of 3′‐UTR containing the rs11536889 G allele induced by lipopolysaccharide (LPS) and interleukin‐6 (IL‐6). Bronchial epithelial cells isolated from participants genotyped as GG, GC, and CC, with no remarkable difference in TLR4 messenger RNA (mRNA) levels were observed among these genotype groups. After stimulating by LPS, a TLR4 ligand, the CC‐genotyped cells expressed higher levels of IL‐8, IL‐6, and tumor necrosis factor alpha (TNF‐α) on their surfaces than cells with the other genotypes. Finally, the western blot analysis results showed that the expression level of IL‐8, IL‐6, and TNF‐α protein was much higher in the CC group than the GC and GG groups subsequent to stimulation by LPS, and the IL‐8, IL‐6, and TNF‐α protein levels in the GC were grouped much lower compared with the GG group. These findings indicated the regulatory association of miR‐1236 with TLR4 and the abnormal expression of TLR4 caused by the presence of rs11536889 in the 3′‐UTR of mRNA, which interfere with its interaction with the miR‐1236, contributing to the risk of VAP.

An alternative miRISC targets a cancer‐associated coding sequence mutation in FOXL2

“…In this study, miR‐1236 selectively targeted the mutated 402C>G locus in the FOXL2 CDS, without affecting WT FOXL2 mRNA expression. Preferential targeting of the mutated “G” allele by miR‐1236 was also reported in recent single‐nucleotide polymorphism (SNP) studies: specific miR‐1236 binding to the G allele over the C allele (rs11536889) in the 3′‐UTR of Toll‐like receptor 4 (Zhao et al , 2019) and specific miR‐1236 targeting of the G allele over the T allele (rs4246215) in the 3′‐UTR of Flap endonuclease 1 (Nanda et al , 2018). Furthermore, our in vivo and in vitro analysis of the phenotypes of miR‐1236 KO cells collectively showed that miR‐1236 acted as an oncomiR in AGCT cells by mainly causing selective variant FOXL2 mRNA degradation (Figs 6 and 7).…”

An alternative miRISC targeting a coding mutation site inFOXL2links to granulosa cell tumor

“…In this study, miR-1236 selectively targeted the mutated 402C>G locus in the FOXL2 CDS, without affecting WT FOXL2 mRNA expression. Preferential targeting of the mutated 'G' allele by miR-1236 was also reported in recent single-nucleotide polymorphism (SNP) studies: specific miR-1236 binding to the G allele over the C allele (rs11536889) in the 3′-UTR of Toll-like receptor 4 (Zhao, Feng et al, 2019) and specific miR-1236 targeting of the G allele over the T allele (rs4246215) in the 3′-UTR of Flap endonuclease 1 (Nanda, Kumar et al, 2018). Furthermore, our in vivo and in vitro analysis of the phenotypes of miR-1236 KO cells collectively showed that miR-1236 acted as an oncomiR in AGCT cells by causing selective variant FOXL2 mRNA degradation (Fig 6 and 7).…”

Incidence Rates, Risk Factors, and Mortality Rates of Ventilator-Associated Pneumonia: A systematic Review and Meta-analysis

“…Recent research on VAP risk factors reported some new findings. Six et al [36] suggested that hyperoxemia was a potential risk factor for VAP. Excess oxygen administration can damage tissues through the production of reactive oxygen species (ROS) [53].…”

“…The full texts of 69 potentially eligible studies were then strictl y assessed. Sixteen studies [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] were included in the systematic review. Finally, 12 studies [23][24][25][26][27][28][29][30][31][32][33][34] were included in the present meta-analysis (…”