Long RNA Sequencing and Ribosome Profiling of Inflamed β-Cells Reveal an Extensive Translatome Landscape

Area of Science:

• Immunology
• Molecular Biology
• Endocrinology

Background:

• Type 1 diabetes (T1D) is an autoimmune disease targeting insulin-producing pancreatic beta-cells.
• Beta-cells may contribute to their own destruction by producing neoantigens via aberrant protein synthesis.
• Previous research linked ribosomal infidelity under stress to neoantigen generation in beta-cells.

Purpose of the Study:

• To investigate the diversity of the beta-cell translatome under inflammatory conditions.
• To identify novel polypeptides arising from noncanonical translation events in human beta-cells.
• To explore the role of nonconventional translation in Type 1 diabetes autoimmunity.

Main Methods:

• Employed transcriptome-wide profiling to map translation initiation start sites.
• Analyzed human beta-cells under standard and inflammatory conditions.
• Identified polypeptides from noncanonical start sites and long noncoding RNA translation.

Main Results:

• Discovered a novel set of polypeptides generated from noncanonical translation initiation sites.
• Revealed translation initiation within long noncoding RNAs in human beta-cells.
• Highlighted the extensive diversity of the beta-cell translatome, particularly under inflammatory stress.

Conclusions:

• Nonconventional translation events significantly expand the repertoire of beta-cell proteins.
• Aberrant protein production from noncanonical sites may contribute to Type 1 diabetes pathogenesis.
• These findings may lead to new biomarkers for beta-cell distress, T1D prediction, and therapeutic targets.