Whole-genome CRISPR screen identifies RAVER1 as a key regulator of RIPK1-mediated inflammatory cell death, PANoptosis

Area of Science:

• Immunology
• Cell Biology
• Genetics

Background:

• Transforming Growth Factor-β-Activated Kinase 1 (TAK1) is crucial for innate immunity and homeostasis.
• Pathogens often inhibit TAK1, prompting host cells to initiate PANoptosis, an inflammatory cell death pathway, as a defense mechanism.
• Understanding the regulation of TAK1 inhibition-induced cell death is vital due to PANoptosis's role in pathological inflammation.

Purpose of the Study:

• To identify novel regulators of TAK1 inhibition-induced cell death using a genome-wide CRISPR screen.
• To elucidate the molecular mechanisms by which identified regulators control PANoptosis.
• To explore the therapeutic potential of targeting these regulators.

Main Methods:

• Conducted a genome-wide CRISPR-Cas9 screen in macrophages to identify regulators of TAK1 inhibition-induced cell death.
• Utilized genetic depletion and manipulation of identified regulators.
• Analyzed RIPK1-mediated inflammasome activation and PANoptosis.

Main Results:

• The CRISPR screen identified polypyrimidine tract-binding protein 1 (PTBP1) and RAVER1 as key regulators of TAK1 inhibition-induced cell death.
• RAVER1 was found to regulate the alternative splicing of RIPK1.
• Genetic depletion of RAVER1 suppressed TAK1 inhibition-induced RIPK1-mediated inflammasome activation and PANoptosis.

Conclusions:

• Genome-wide CRISPR screens are effective for dissecting complex cell death pathways in myeloid cells.
• RAVER1 is a novel regulator of PANoptosis, acting via RIPK1 alternative splicing.
• The findings offer potential therapeutic targets for modulating inflammatory cell death pathways.