Serine biosynthesis as a novel therapeutic target for dilated cardiomyopathy.

Aims: Genetic dilated cardiomyopathy (DCM) is a leading cause of heart failure. Despite significant progress in understanding the genetic aetiologies of DCM, the molecular mechanisms underlying the pathogenesis of familial DCM remain unknown, translating to a lack of disease-specific therapies. The discovery of novel targets for the treatment of DCM was sought using phenotypic sceening assays in induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) that recapitulate the disease phenotypes in vitro.

Generation of a dual edited human induced pluripotent stem cell Myl7-GFP reporter line with inducible CRISPRi/dCas9.

Temporal regulation of CRISPRi activity is critical for genetic screens. Here, we present an inducible CRISPRi platform enabling selection of iPSC-derived cardiomyocytes and reversible gene knockdown. We targeted a doxycycline-inducible dCas9-KRAB-mCherry cassette into the AAVS1 locus in an MYL7-mGFP reporter iPSC line.

Generation of AAVS1 integrated doxycycline-inducible CRISPR-Prime Editor human induced pluripotent stem cell line.

Prime editing uses the Cas9 nickase fused to a reverse transcriptase to copy a DNA sequence into a specific locus from a 'prime editing' guide RNA (pegRNA), eliminating the need for double-stranded DNA breaks and donor DNA templates. To facilitate prime editing in human induced pluripotent stem cells (iPSCs), we integrated a doxycycline-inducible Prime Editor protein (PE2) into the AAVS1 genomic safe harbor locus. Prime editing of iPSCs resulted in precise insertion of three nucleotides in HEK3 locus with high efficiency, demonstrating the utility of this approach.

Unfolded Protein Response as a Compensatory Mechanism and Potential Therapeutic Target in PLN R14del Cardiomyopathy.

Background: Phospholamban (PLN) is a critical regulator of calcium cycling and contractility in the heart. The loss of arginine at position 14 in PLN (R14del) is associated with dilated cardiomyopathy with a high prevalence of ventricular arrhythmias. How the R14 deletion causes dilated cardiomyopathy is poorly understood, and there are no disease-specific therapies.

A Novel Recessive Mutation in SPEG Causes Early Onset Dilated Cardiomyopathy.

Dilated cardiomyopathy (DCM) is a common cause of heart failure and sudden cardiac death. It has been estimated that up to half of DCM cases are hereditary. Mutations in more than 50 genes, primarily autosomal dominant, have been reported.