Embryonic stem cells can be instructed to form gastruloids, an efficient four-dimensional model for studying some aspects of post-implantation embryonic patterning, which undergo gastrulation-like pro Show more
Embryonic stem cells can be instructed to form gastruloids, an efficient four-dimensional model for studying some aspects of post-implantation embryonic patterning, which undergo gastrulation-like processes, illustrating their robust self-organizing capacity to form embryo-like patterns. Here, we study the molecular and cellular mechanisms underlying this remarkable property and report that self-organization competence is associated with a cell-specific coordination of a cadherin switch. E-cadherin repression by Snai1 is indeed critical for this process, with Snai1 triggering the cell-specific pace of pluripotency exit, thus allowing a coordinated transition from E- to N-cadherin to occur. In contrast, we find that N-cadherin inactivation unleashes gastruloids' morphogenetic competence, for it leads to the formation of embryo-like structures with proper rostro-caudal somite patterning without requiring any addition of extracellular matrix. Altogether, this work establishes a molecular mechanism that integrates the exit from pluripotency and the pace of cell differentiation, leading to the self-organizing potential of gastruloids. Show less
Hypothermic-oxygenated-machine-perfusion (HOPE) allows assessment/reconditioning of livers procured from high-risk donors before transplantation. Graft referral to HOPE mostly depends on surgeons' sub Show more
Hypothermic-oxygenated-machine-perfusion (HOPE) allows assessment/reconditioning of livers procured from high-risk donors before transplantation. Graft referral to HOPE mostly depends on surgeons' subjective judgment, as objective criteria are still insufficient. We investigated whether analysis of effluent fluids collected upon organ flush during static-cold-storage can improve selection criteria for HOPE utilization. Effluents were analyzed to determine cytolysis enzymes, metabolites, inflammation-related mediators, and damage-associated-molecular-patterns. Molecular profiles were assessed by unsupervised cluster analysis. Differences between "machine perfusion (MP)-yes" vs. "MP-no"; "brain-death (DBD) vs. donation-after-circulatory-death (DCD)"; "early-allograft-dysfunction (EAD)-yes" vs. "EAD-no" groups, as well as correlation between effluent variables and transplantation outcome, were investigated. Livers assigned to HOPE ( Show less