Antisense overlapping long non-coding RNA regulates coding arachidonate 12-lipoxygenase gene by translational...

Area of Science:

• Molecular Biology
• Gene Regulation
• Lipid Metabolism

Background:

• The arachidonate 12-lipoxygenase (ALOX12) enzyme is crucial for generating bioactive lipid mediators involved in various biological processes and diseases.
• The human genome reveals the ALOX12 gene overlaps with an antisense non-coding gene, ALOX12-antisense 1 (ALOX12-AS1).

Purpose of the Study:

• To investigate if ALOX12-AS1 long non-coding RNA (lncRNA) interacts with ALOX12 mRNA to form an antisense-sense duplex.
• To determine if this interaction mediates a novel regulatory mechanism controlling cellular ALOX12 content.

Main Methods:

• RNA-FISH to determine lncRNA expression and localization in human tissues and cell types.
• Treatment of THP-1 cells with phorbol ester to induce lncRNA translocation.
• Validation of sense/antisense duplex formation and association with ribosomal proteins in HEK293 cells.

Main Results:

• Two major isoforms of ALOX12-AS1 lncRNA are ubiquitously expressed and show cell-type-specific localization (cytosolic, nuclear, nucleolar).
• Phorbol ester treatment caused ALOX12-AS1 translocation, reducing ALOX12 protein without affecting mRNA levels.
• Sense/antisense duplex formation and its association with ribosomal proteins were confirmed.

Conclusions:

• ALOX12-AS1 functions as an antisense lncRNA to downregulate ALOX12 translation via a sense/antisense duplex mechanism.
• This study uncovers a new regulatory pathway for ALOX12, impacting bioactive lipid mediator modulation in health and disease.