CARMAL Is a Long Non-coding RNA Locus That Regulates MFGE8 Expression

Area of Science:

• Genetics
• Molecular Biology
• Cardiovascular Disease Research

Background:

• Genome-wide association studies link non-protein coding regions to coronary artery disease (CAD).
• The CAD Associated Region between MFGE8 and ABHD2 (CARMA) is an 18 kb haplotype regulating nearby genes.
• A long non-coding RNA locus, CARMAL, adjacent to the CARMA region warrants further investigation.

Purpose of the Study:

• To investigate the function of the CARMAL long non-coding RNA.
• To determine if CARMAL expression is influenced by CAD-associated variants.
• To explore CARMAL's role in regulating gene expression, particularly MFGE8.

Main Methods:

• Expression-genotype correlation analyses using public databases.
• Gene targeting approaches in HEK293T cells: CRISPRa, CRISPRi, CRISPR-mediated knock-out, antisense, and overexpression.
• Integrative bioinformatic analyses of transcriptomes from CARMAL-deleted cells.

Main Results:

• CARMAL expression is influenced by CAD-associated variants, suggesting potential cardioprotective functions.
• CARMAL deletion or reduced expression via CRISPRi increased MFGE8 levels.
• CARMAL appears to repress MFGE8 expression under basal conditions.
• Transcriptome analysis of CARMAL-deleted cells suggests roles in leucine metabolism, splicing, and transcriptional regulation.

Conclusions:

• CARMAL is a long non-coding RNA potentially involved in regulating MFGE8 expression.
• CARMAL may possess cardioprotective functions, warranting further mechanistic studies.
• The CARMAL locus is implicated in broader cellular processes including metabolism and gene regulation.