Regulation of CLK1 Isoform Expression by Alternative Splicing in Activated Human Monocytes Contributes to...

Area of Science:

• Immunology
• Molecular Biology
• Cell Biology

Background:

• Alternative splicing is crucial for immune regulation.
• The role of CDC-like kinase 1 (CLK1) in monocyte function is not well understood.

Purpose of the Study:

• To investigate CLK1 alternative splicing in human monocytes.
• To determine the functional consequences of CLK1 isoform switching in response to lipopolysaccharide (LPS).

Main Methods:

• Long-read and short-read RNA sequencing to identify and quantify CLK1 isoforms.
• RT-qPCR and Western blot analysis to confirm splicing changes and protein expression.
• Pharmacological inhibition of CLK1 to assess its role in TNFα production.

Main Results:

• Human monocytes express distinct CLK1 isoforms, with a truncated form (CLK1Δ4) predominant in resting cells.
• LPS stimulation shifts expression to the full-length CLK1 isoform (CLK1+4), increasing transcript stability and protein levels.
• CLK1 inhibition selectively reduces TNFα production, indicating its role in pro-inflammatory signaling.

Conclusions:

• Monocyte activation involves a stimulus-dependent switch in CLK1 splicing.
• Differential CLK1 isoform expression modulates inflammatory responses.
• Targeting CLK1 splicing represents a potential therapeutic strategy for immune-related diseases involving activated monocytes.