bioRxiv Science⌕ Search

bioRxiv · 10.1101/2022.02.18.481057

Genomewide m6A mapping uncovers dynamic changes in the m6A epitranscriptome of cisplatin-treated apoptotic HeLa cells

Abstract

Cisplatin, which is a traditional cancer therapeutic drug, induces apoptosis by modulating a diverse array of gene regulatory mechanisms. However, cisplatin-mediated changes in the m6A methylome is unknown. We employed m6A miCLIP-seq to investigate the effect of m6A methylation events under cisplatin-mediated apoptotic conditions in HeLa cells. Our high-resolution approach revealed numerous m6A marks on 972 target mRNAs with an enrichment on 132 apoptotic mRNAs. Following validation of site-specific m6A events on candidate RNAs, we tracked the fate of candidate mRNAs under METTL3 knockdown and cisplatin treatment conditions. We detected perturbations in the translational efficiency of PMAIP1 and PHLDA1 transcripts based on the polysome profile analyses. Congruently, PMAIP1 and p53 amounts were dependent on METTL3. Additionally, cisplatin-mediated apoptosis was sensitized by METTL3 knockdown. These results suggest that apoptotic pathways are modulated by m6A methylation events and METTL3-p53-PMAIP1 axis modulates cisplatin-mediated apoptosis in HeLa cells.

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Akcaoz, A., Tuncel, O., Gelmez, A. B., Saglam, B., Vatansever, I. E., Akgul, B.. 2022-02-19. Genomewide m6A mapping uncovers dynamic changes in the m6A epitranscriptome of cisplatin-treated apoptotic HeLa cells. https://doi.org/10.1101/2022.02.18.481057

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Sequence context and partner availability specify divergent cell fates from a single transcription factor

Transcription factors drive the gene regulatory networks that control developmental transitions, yet which of their many targets a cell uses remains unresolved. Expressing Cebp, Cebp{beta} or Cebp{delta} identically, alone or with Oct4, Sox2, Klf4 and cMyc, gave four outcomes: adipocyte from fibroblasts and neural stem cells, trophectoderm from embryonic stem cells, and myeloid from B cells. Raising Cebp levels changed how many sites it reached, not which sequence it read: clustered motifs maintained somatic enhancers, while spillover onto low-copy sites created de novo enhancers carrying composites of Cebp and cell-type-restricted partners. In fibroblasts, Cebp also redistributed Oct4, Sox2 and Klf4 from early targets, blocking iPSC formation. Supplying the predicted partners rewrote the output: Spi1 redirected Cebp into parallel adipogenic and myeloid programs, via a transient PpargCD45 state using separate enhancers for each; TFAP2C abolished adipogenic conversion. Motif density and partner composites therefore assemble a factor's instructive output in the receiving cell.

cell biology↗

High-content screening identifies FDA-approved activators of mitophagy

Mitochondrial diseases are highly heterogeneous disorders caused by defects in oxidative phosphorylation, for which only limited therapeutic options are available. The elimination of dysfunctional mitochondria via mitophagy activation is an attractive strategy to treat several mitochondrial diseases, irrespective of the underlying genetic defect. To identify pharmacological activators of this pathway, we performed a high-content screening of 1,971 FDA-approved compounds using cellular reporters of TFEB nuclear translocation and mitophagy. This screening identified 294 compounds that promoted TFEB translocation, nine of which increased the number of mitolysosomes without compromising cell viability or damaging mitochondria. Among the selected compounds, Meptazinol and Ponatinib emerged as the top-ranked mitophagy inducers in fibroblasts from patients with complex I and IV deficiency, respectively, and were prioritised for further characterisation. However, they did not rescue the bioenergetic defect, suggesting that the stimulation of mitophagy per se is not sufficient to ameliorate the OXPHOS defect in mitochondrial diseases. Overall, our findings establish a scalable platform for the identification of pharmacological activators of TFEB and identify candidate compounds for therapeutic modulation of mitophagy.

cell biology↗

Matrix Gla Protein deficiency reveals a previously unrecognized mucosal calcification in the mouse airways

Tracheal calcification is a common finding that is considered to have limited clinical significance when detected most often in elderly individuals. Despite its frequent occurrence, the cellular and molecular mechanisms at the origin of tracheal calcification remain largely unexplored. In this context, we aimed to characterize the development of tracheal calcification, and to determine the role of matrix Gla protein (MGP), a major inhibitor of ectopic calcification whose genetic or pharmacologic deficiency is associated with premature tracheal calcification in humans. We found that wild-type mice undergo an unexpected early physiologic calcification of the tracheal cartilage rings beginning around one month after birth. This calcification progresses in a dynamic rostro-caudal sequence through a process involving terminal differentiation of tracheal chondrocytes. These findings challenge the prevailing view that tracheal cartilage is a permanent hyaline cartilage and instead reveals an early and highly organized physiologic calcification process. Furthermore, our findings further identify MGP as a key regulator of calcification within the respiratory tract. Indeed, MGP deficiency not only markedly accelerates tracheal cartilage calcification through a similar pattern and mechanism but also induces a previously unrecognized calcification of the tracheal mucosa, a lesion absent in wild-type mice. These alterations could partly explain the respiratory manifestations observed in MGP-deficient patients having Keutel syndrome, which include dyspnea, cough, stridor, and recurrent infections, symptoms previously being mainly attributed to calcification of the tracheal cartilage rings.

cell biology↗