An Unbiased High Throughput Screen to Identify Novel Effectors that Impact on Cardiomyocyte Aggregate Levels
Rationale: Post-mitotic cells such as cardiomyocytes appear to be particularly susceptible to proteotoxic stimuli, and large, proteinaceous deposits are characteristic of the Desmin Related Cardiomyopathies and crystallin cardiomyopathic diseases. Increased activity of protein clearance pathways in the cardiomyocyte such as proteasomal degradation and autophagy have proven to be beneficial in maintaining cellular and cardiac function in the face of multiple proteotoxic insults, holding open the possibility of targeting these processes for the development of effective therapeutics.
Objective: Here we undertake an unbiased, total genome screen for RNA transcripts and their protein products that impact on aggregate accumulations in the cardiomyocytes.
Methods and Results: Primary mouse cardiomyocytes that accumulate aggregates as a result of a mutant αB crystallin causative for human Desmin Related Cardiomyopathy, were used for a total genome-wide screen to identify gene products that impacted on aggregate formation. We infected cardiomyocytes using a short hairpin RNA lentivirus library in which the mouse genome was represented. The screen identified multiple candidates in a number of cell signaling pathways that were able to mediate significant decreases in aggregate levels.
Conclusions: Subsequent validation of one of these candidates, Janus kinase 1 (Jak1), a tyrosine kinase of the non-receptor type, confirmed the usefulness of this approach in identifying previously unsuspected players in proteotoxic processes.
- heart failure
- Janus kinase
- cardiovascular research
- heart defect
- Received March 6, 2017.
- Revision received June 23, 2017.
- Accepted June 26, 2017.