Loss of function of the carbon catabolite repressor CreA leads to low but inducer-independent expression from the feruloyl esterase B promoter in Aspergillus niger

Microbial Biotechnolog

Biallelic variants in FLII cause pediatric cardiomyopathy by disrupting cardiomyocyte cell adhesion and myofibril organization

Pediatric cardiomyopathy (CM) represents a group of rare, severe disorders that affect the myocardium. To date, the etiology and mechanisms underlying pediatric CM are incompletely understood, hampering accurate diagnosis and individualized therapy development. Here, we identified biallelic variants in the highly conserved flightless-I (FLII) gene in 3 families with idiopathic, early-onset dilated CM. We demonstrated that patient-specific FLII variants, when brought into the zebrafish genome using CRISPR/Cas9 genome editing, resulted in the manifestation of key aspects of morphological and functional abnormalities of the heart, as observed in our patients. Importantly, using these genetic animal models, complemented with in-depth loss-of-function studies, we provided insights into the function of Flii during ventricular chamber morphogenesis in vivo, including myofibril organization and cardiomyocyte cell adhesion, as well as trabeculation. In addition, we identified Flii function to be important for the regulation of Notch and Hippo signaling, crucial pathways associated with cardiac morphogenesis and function. Taken together, our data provide experimental evidence for a role for FLII in the pathogenesis of pediatric CM and report biallelic variants as a genetic cause of pediatric CM

Coupling 3D Printing and Novel Replica Molding for In House Fabrication of Skeletal Muscle Tissue Engineering Devices

The transition from 2D to 3D engineered tissue cultures is changing the way biologists can perform in vitro functional studies. However, there has been a paucity in the establishment of methods required for the generation of microdevices and cost-effective scaling up. To date, approaches including multistep photolithography, milling and 3D printing have been used that involve specialized and expensive equipment or time-consuming steps with variable success. Here, a fabrication pipeline is presented based on affordable off-the-shelf 3D printers and novel replica molding strategies for rapid and easy in-house production of hundreds of 3D culture devices per day, with customizable size and geometry. This pipeline is applied to generate tissue engineered skeletal muscles in vitro using human induced pluripotent stem cell-derived myogenic progenitors. These production methods can be employed in any standard biomedical laboratory.</p