The calcium-triggered molecular scenario underlying mutant ACTG2-caused defective contraction

Experimental evidence points out that CIPO-related mutations of ACTG2 induce a defect in cell contraction. This was also highlighted by experimental tests performed in our laboratory on primary cell cultures carrying the p.R257C or p.R38H mutations in ACTG2, known to cause CIPO. In order to identify the pathogenic molecular mechanism related to mutated ACTG2, in the present project we propose to induce contraction in vitro on intestinal smooth muscle cell lines, and to observe the resulting biochemical cascade, both in non-mutated cells and in cells presenting mutations associated to different degrees of severity of CIPO pathology. For this purpose, we will evaluate both the dynamics of calcium release, which is the second messenger activated in the biological process of contraction, and the post-contraction cellular transcription profile, to identify the genes involved in the immediate and tardive responses to the stimulus. The comparison of the data obtained from a non-mutated cell line with those carrying mutated ACTG2 will allow identifying the molecular effects on the cell contraction process of ACTG2 mutations responsible for CIPO.