ABSTRACT
The transcriptional mechanisms driving lineage specification during development are still largely unknown, as the interplay of multiple transcription factors makes it difficult to dissect these molecular events. Using a cell-based differentiation platform to probe transcription function, we investigated the role of the key paraxial mesoderm and skeletal myogenic commitment factors-mesogenin 1 (Msgn1), T-box 6 (Tbx6), forkhead box C1 (Foxc1), paired box 3 (Pax3), Paraxis, mesenchyme homeobox 1 (Meox1), sine oculis-related homeobox 1 (Six1), and myogenic factor 5 (Myf5)-in paraxial mesoderm and skeletal myogenesis. From this study, we define a genetic hierarchy, with Pax3 emerging as the gatekeeper between the presomitic mesoderm and the myogenic lineage. By assaying chromatin accessibility, genomic binding and transcription profiling in mesodermal cells from mouse and human Pax3-induced embryonic stem cells and Pax3-null embryonic day (E)9.5 mouse embryos, we identified conserved Pax3 functions in the activation of the skeletal myogenic lineage through modulation of Hedgehog, Notch, and bone morphogenetic protein (BMP) signaling pathways. In addition, we demonstrate that Pax3 molecular function involves chromatin remodeling of its bound elements through an increase in chromatin accessibility and cooperation with sine oculis-related homeobox 4 (Six4) and TEA domain family member 2 (Tead2) factors. To our knowledge, these data provide the first integrated analysis of Pax3 function, demonstrating its ability to remodel chromatin in mesodermal cells from developing embryos and proving a mechanistic footing for the transcriptional hierarchy driving myogenesis.
Subject(s)
Chromatin Assembly and Disassembly , DNA-Binding Proteins/genetics , Homeodomain Proteins/genetics , Mesoderm/metabolism , Muscle Cells/metabolism , Muscle Development/genetics , PAX3 Transcription Factor/genetics , Trans-Activators/genetics , Transcription Factors/genetics , Animals , Basic Helix-Loop-Helix Transcription Factors/genetics , Basic Helix-Loop-Helix Transcription Factors/metabolism , Cell Differentiation , Cell Line , DNA-Binding Proteins/metabolism , Embryo, Mammalian , Embryonic Stem Cells/cytology , Embryonic Stem Cells/metabolism , Forkhead Transcription Factors/genetics , Forkhead Transcription Factors/metabolism , Gene Expression Regulation, Developmental , Homeodomain Proteins/metabolism , Humans , Mesoderm/cytology , Mesoderm/growth & development , Mice , Mice, Transgenic , Muscle Cells/cytology , Muscle, Skeletal/cytology , Muscle, Skeletal/growth & development , Muscle, Skeletal/metabolism , Myogenic Regulatory Factor 5/genetics , Myogenic Regulatory Factor 5/metabolism , PAX3 Transcription Factor/metabolism , Signal Transduction , T-Box Domain Proteins , TEA Domain Transcription Factors , Trans-Activators/metabolism , Transcription Factors/metabolismABSTRACT
OBJECTIVE: As surgical residents continue in their training, they are expected to not only take part in more complicated procedures, but to also serve as leaders in their respective care teams. While surgical skills are intensively taught in surgical residency programs, leadership is often learned informally, to the detriment of residents. Our curriculum was developed and implemented to provide foundational knowledge for surgical residents as they take on senior roles so that they may successfully act as leaders. This educational workshop was effective and efficient and can be applied at other residency programs that seek to improve the leadership skills of their residents. DESIGN: Implementation of a 3-day program focused on leadership, surgical skills, and career development to provide rising PGY-4 surgical residents with the abilities necessary for successful training. SETTING: This program was implemented at the University of Minnesota General Surgery residency program. PARTICIPANTS: Rising PGY-4 general surgery residents. RESULTS: The program consisted of a 3-day workshop which all rising PGY-4 residents participating in before transitioning into their respective roles. The program was led by the general surgery faculty. CONCLUSIONS: Curricula focused on developing leadership skills in residents can be effectively applied in a time-efficient manner that can benefit the residents as they move into official leadership roles on the care team.
ABSTRACT
OBJECTIVES: To investigate the effect of a restrictive blood product utilization protocol on blood product utilization and clinical outcomes. DESIGN: We retrospectively reviewed all adult extracorporeal membrane oxygenation (ECMO) patients from January 2019 to December 2021. The restrictive protocol, implemented in March 2020, was defined as transfusion of blood products for a hemoglobin level less than 7, platelet levels less than 50, and/or fibrinogen levels less than 100. Subgroup analysis was performed based on the mode of ECMO received: venoarterial ECMO, venovenous ECMO, and ECMO support following extracorporeal cardiopulmonary resuscitation (ECPR). SETTING: M Health Fairview University of Minnesota Medical Center. PATIENTS: The study included 507 patients. INTERVENTIONS: One hundred fifty-one patients (29.9%) were placed on venoarterial ECMO, 70 (13.8%) on venovenous ECMO, and 286 (56.4%) on ECPR. MEASUREMENTS AND MAIN RESULTS: For patients on venoarterial ECMO (48 [71.6%] vs. 52 [63.4%]; p = 0.374), venovenous ECMO (23 [63.9%] vs. 15 [45.5%]; p = 0.195), and ECPR (54 [50.0%] vs. 69 [39.2%]; p = 0.097), there were no significant differences in survival on ECMO. The last recorded mean hemoglobin value was also significantly decreased for venoarterial ECMO (8.10 [7.80-8.50] vs. 7.50 [7.15-8.25]; p = 0.001) and ECPR (8.20 [7.90-8.60] vs. 7.55 [7.10-8.88]; p < 0.001) following implementation of the restrictive transfusion protocol. CONCLUSIONS: These data suggest that a restrictive transfusion protocol is noninferior to ECMO patient survival. Additional, prospective randomized trials are required for further investigation of the safety of a restrictive transfusion protocol.