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Purpose: Our purpose was to investigate the role of recombinant protein flagellin A N/C (FlaA N/C) protein-mediated pyroptosis inhibition and related miRNA in radiation protection.Methods and Materials: Mice received 10 Gy irradiation after FlaA N/C pretreatment, IRAK-1/4 Inhibitor I treatment, or pyrrolidine dithiocarbamate treatment. Human intestinal epithelial cells (HIEC) received 10 Gy irradiation after FlaA N/C pretreatment, overexpressed miR-142a-3p with miR-142a-3p mimics, or inhibited miR-142a-3p with miR-142a-3p inhibitor. Mouse & Rat miRNA OneArray determined the change in relevant miRNA after FlaA N/C pretreatment; real-time polymerase chain reaction detected IRAK1 and miR-142a-3p expression; a CCK-8 assay evaluated cell viability; LDH release analyzed cytotoxicity; caspase-1 activity assay, interleukin-1β level, and flow cytometry analyzed pyroptosis in cells; hematoxylin-eosin staining evaluated the damage to intestinal tissue; CO-IP detected the inflammation activation; immunohistochemistry, Western blot analysis, and immunofluorescence analyzed activation of pyroptosis-related proteins and the activation of NF-kB signaling pathways; and luciferase reporter assay and fluorescence in situ hybridization detected the interaction between miR-142a-3p and IRAK1.Results: FlaA N/C reduced radiation-induced pyroptosis in vivo and in vitro, and miR-142a-3p expression increased after FlaA N/C pretreatment. Upregulating the expression of miR-142a-3p inhibited radiation-induced pyroptosis in HIEC, and downregulating the expression of miR-142a-3p led to radiation-induced pyroptosis in HIEC after FlaA N/C pretreatment. IRAK1 was a direct target of miR-142a-3p and played an important role in radiation-induced pyroptosis in HIEC. Inhibiting IRAK1 reduced radiation-mediated pyroptosis in mice intestines. miR-142a-3p downregulated IRAK1 and suppressed the NF-kB pathway. Inhibiting the NF-kB signaling pathway can reduce radiation-mediated pyroptosis in mice intestines.Conclusions: Our findings indicated this new radioprotectant protein regulates miR-142a-3p, effectively inhibiting radiation-induced pyroptosis mediated by the IRAK1/NF-κB signaling pathway in intestinal cells. [ABSTRACT FROM AUTHOR]

Scutellarin is used to treat brain ischaemia. However, its underlying mechanism of action remains unclear. This study aimed to elucidate the potential mechanism of action of scutellarin in brain ischaemia through network pharmacology and experimental verification. The JAK2/STAT3 signalling pathway was identified and experimentally verified. Expression of JAK2/STAT3 signalling related proteins in TNC-1 astrocytes with BV-2 microglia-conditioned medium (CM), CM + lipopolysaccharide (LPS) (CM + L), and CM pretreated with scutellarin + LPS (CM + SL) was analysed by Western Blot and immunofluorescence staining. Expression levels of JAK2, p-JAK2, STAT3, and p-STAT3 were evaluated in astrocytes pre-treated with AG490. Middle cerebral artery occlusion (MCAO) in rats was performed in different experimental groups to detect expression of the above biomarkers. Network pharmacology suggested that the JAK2/STAT3 signalling pathway is one of the mechanisms by which scutellarin mitigates cerebral ischaemic damage. In TNC-1 astrocytes, p-JAK2 and p-STAT3 expression were significantly up-regulated in the CM + L group. Scutellarin promoted the up-regulation of various markers and AG490 neutralised the effect of scutellarin. In vivo, up-regulation of p-JAK2 and p-STAT3 after ischaemia is known. These results are consistent with previous reports. Scutellarin further enhanced this upregulation at 1, 3, and 7 d after MCAO. Scutellarin exerts its therapeutic effects on cerebral ischaemia by activating the astrocyte JAK2/STAT3 signalling, which provides a firm experimental basis for its clinical application. [ABSTRACT FROM AUTHOR]

Background: Previous studies have shown that the N6-methyladenosine (m6A) modification enhances the binding ability of mRNAs/long noncoding RNAs (lncRNAs) to microRNAs (miRNAs), but the impact of this modification on the competitive endogenous RNA (ceRNA) function of circular RNAs (circRNAs) is unclear. Methods: We used a human circRNA microarray to detect the expression profiles of circRNAs in 3 pairs of cancer and paracancerous tissues from patients with colorectal cancer (CRC) and 3 pairs of peripheral blood specimens from patients with CRC and healthy individuals. The circRNAs highly expressed in both peripheral blood and tumour tissues of patients with CRC, including circALG1, were screened. A quantitative reverse-transcription polymerase chain reaction (qRT-PCR) analysis of an expanded sample size was performed to detect the expression level of circALG1 in peripheral blood and tumour tissues of patients with CRC and determine its correlation with clinicopathological features, and circRNA loop-forming validation and stability assays were then conducted. Transwell assays and a nude mouse cancer metastasis model were used to study the function of circALG1 in CRC and the role of altered m6A modification levels on the regulation of circALG1 function. qRT-PCR, western blot (WB), Transwell, RNA-binding protein immunoprecipitation (RIP), RNA antisense purification (RAP), and dual-luciferase reporter gene assays were performed to analyse the ceRNA mechanism of circALG1 and the effect of the m6A modification of circALG1 on the ceRNA function of this circRNA. Results: CircALG1 was highly expressed in both the peripheral blood and tumour tissues of patients with CRC and was closely associated with CRC metastasis. CircALG1 overexpression promoted the migration and invasion of CRC cells, and circALG1 silencing and reduction of the circALG1 m6A modification level inhibited CRC cell migration and invasion. In vivo experiments further confirmed the prometastatic role of circALG1 in CRC. Further mechanistic studies showed that circALG1 upregulated the expression of placental growth factor (PGF) by binding to miR-342-5p and that m6A modification enhanced the binding of circALG1 to miR-342-5p and promoted its ceRNA function. Conclusion: M6A modification enhances the binding ability of circALG1 to miR-342-5p to promote the ceRNA function of circALG1, and circALG1 could be a potential therapeutic target in and a prognostic marker for CRC. [ABSTRACT FROM AUTHOR]

C. qRT-PCR and WB assays were performed to detect the interference and overexpression efficiency of PGF in HCT116 circALG1 overexpression and SW480 sh-circALG1 cells. F. qRT-PCR and WB assays were performed to assess the overexpression efficiency of PGF in HCT116 cells. [Extracted from the article]