Dataset Information

ALKBH5-mediated m⁶ A demethylation of TIRAP mRNA promotes radiation-induced liver fibrosis and decreases radiosensitivity of hepatocellular carcinoma.

ABSTRACT:

Background

Radiation-induced hepatic stellate cell (HSC) activation promotes radiation-induced liver fibrosis (RILF), a complication for hepatocellular carcinoma (HCC) radiotherapy. The demethylase alpha-ketoglutarate-dependent dioxygenase alkB homolog 5 (ALKBH5) decreases N6-methyladenylate methylation (m⁶ A) modification of RNA, while its role in regulating RILF pathogenesis and HCC radiosensitivity remains unknown.

Methods

Methylated RNA immunoprecipitation sequencing (MeRIP-seq) and RNA-sequencing (RNA-seq) were used to screen target genes regulated by ALKBH5. HSC with altered ALKBH5 expression was used to assess irradiation-induced HSC activation and the effect of HSC on recruitment and polarisation of monocytes. Key cytokines in medium from irradiated HSC-educated monocytes were identified by cytokine array detection. The effects of blocking ALKBH5 and key cytokines on RILF and HCC radiosensitivity were also evaluated.

Results

Radiation-induced ALKBH5 expression in HSC mediated m⁶ A demethylation of toll-interleukin 1 receptor domain containing adaptor protein (TIRAP) mRNA and activated its downstream NF-κB and JNK/Smad2 pathways to promote HSC activation. Additionally, ALKBH5 regulated CCL5 secretion by irradiated HSC to promote monocyte recruitment and M2 macrophage polarisation. Notably, polarised monocytes secreted CCL20 to up-regulate ALKBH5 expression in HSC, and reduce HCC radiosensitivity by activating ALKBH5/TIRAP axis in HCC cells. ALKBH5 knockdown-combined CCR6 (CCL20 receptor) inhibitor significantly alleviated RILF and improved HCC radiosensitivity in mice. HCC patients with high ALKBH5 and TIRAP expression were prone to radiation-induced liver injury and poor tumour response to radiotherapy.

Conclusions

Collectively, irradiation up-regulates ALKBH5 in HSC to mediate monocyte recruitment and M2 polarisation and form positive feedback to promote RILF and reduce HCC radiosensitivity. The dual roles of ALKBH5 as a microenvironmental regulator and radiosensitisation target provide new ideas for RILF prevention and radiosensitisation of HCC.

SUBMITTER: Chen Y

PROVIDER: S-EPMC9931500 | biostudies-literature | 2023 Feb

REPOSITORIES: biostudies-literature

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Publications

ALKBH5-mediated m<sup>6</sup> A demethylation of TIRAP mRNA promotes radiation-induced liver fibrosis and decreases radiosensitivity of hepatocellular carcinoma.

Chen Yuhan Y Zhou Peitao P Deng Yixun Y Cai Xinni X Sun Mingrui M Sun Yining Y Wu Dehua D

Clinical and translational medicine 20230201 2

<h4>Background</h4>Radiation-induced hepatic stellate cell (HSC) activation promotes radiation-induced liver fibrosis (RILF), a complication for hepatocellular carcinoma (HCC) radiotherapy. The demethylase alpha-ketoglutarate-dependent dioxygenase alkB homolog 5 (ALKBH5) decreases N6-methyladenylate methylation (m<sup>6</sup> A) modification of RNA, while its role in regulating RILF pathogenesis and HCC radiosensitivity remains unknown.<h4>Methods</h4>Methylated RNA immunoprecipitation sequencin ...[more]

PMID: 36792369

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Project description:BackgroundElevated extracellular matrix (ECM) accumulation is a major contributing factor to the pathogenesis of fibrotic diseases. Recent studies have indicated that N6-methyladenosine (m6A) RNA modification plays a pivotal role in modulating RNA stability and contribute to the initiation of various pathological conditions. Howbeit, the precise mechanism by which m6A influences ECM deposition remains unclear.MethodsIn this study, we used hypertrophic scars (HTSs) as a paradigm to investigate ECM-related diseases. We focused on the role of ALKBH5-mediated m6A demethylation within the pathological progression of HTSs and examined its correlation with clinical stages. The effects of ALKBH5 ablation on ECM components were studied both in vivo and in vitro. Downstream targets of ALKBH5, along with their underlying mechanisms, were identified using integrated high-throughput analysis, RNA-binding protein immunoprecipitation and RNA pull-down assays. Furthermore, the therapeutic potential of exogenous ALKBH5 overexpression was evaluated in fibrotic scar models.ResultsALKBH5 was decreased in fibroblasts derived from HTS lesions and was negatively correlated with their clinical stages. Importantly, ablation of ALKBH5 promoted the expression of COL3A1, COL1A1, and ELN, leading to pathological deposition and reconstruction of the ECM both in vivo and in vitro. From a therapeutic perspective, the exogenous overexpression of ALKBH5 significantly inhibited abnormal collagen deposition in fibrotic scar models. As determined by integrated high-throughput analysis, key ECM components including COL3A1, COL1A1, and ELN are direct downstream targets of ALKBH5. By means of its mechanism, ALKBH5 inhibits the expression of COL3A1, COL1A1, and ELN by removing m6A from mRNAs, thereby decreasing their stability in a YTHDF1-dependent manner.ConclusionsOur study identified ALKBH5 as an endogenous suppressor of pathological ECM deposition, contributing to the development of a reprogrammed m6A-targeted therapy for HTSs.

Dataset Information

ALKBH5-mediated m⁶ A demethylation of TIRAP mRNA promotes radiation-induced liver fibrosis and decreases radiosensitivity of hepatocellular carcinoma.

Background

Methods

Results

Conclusions

Publications

ALKBH5-mediated m<sup>6</sup> A demethylation of TIRAP mRNA promotes radiation-induced liver fibrosis and decreases radiosensitivity of hepatocellular carcinoma.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Dataset Information

ALKBH5-mediated m6 A demethylation of TIRAP mRNA promotes radiation-induced liver fibrosis and decreases radiosensitivity of hepatocellular carcinoma.

Background

Methods

Results

Conclusions

Publications

ALKBH5-mediated m<sup>6</sup> A demethylation of TIRAP mRNA promotes radiation-induced liver fibrosis and decreases radiosensitivity of hepatocellular carcinoma.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

ALKBH5-mediated m⁶ A demethylation of TIRAP mRNA promotes radiation-induced liver fibrosis and decreases radiosensitivity of hepatocellular carcinoma.