Background Craniofacial anomalies involve defective pharyngeal arch development and neural crest function. Copy number variation at 1p35, containing histone deacetylase 1 (Hdac1), or 6q21-22, containing Hdac2, are implicated in patients with craniofacial defects, suggesting an important role in guiding neural crest development. However, the roles of Hdac1 and Hdac2 within neural crest cells remain unknown. Results The neural crest and its derivatives express both Hdac1 and Hdac2 during early murine development. Ablation of Hdac1 and Hdac2 within murine neural crest progenitor cells cause severe hemorrhage, atrophic pharyngeal arches, defective head morphogenesis, and complete embryonic lethality. Embryos lacking Hdac1 and Hdac2 in the neural crest exhibit decreased proliferation and increased apoptosis in both the neural tube and the first pharyngeal arch. Mechanistically, loss of Hdac1 and Hdac2 upregulates cyclin-dependent kinase inhibitors Cdkn1a, Cdkn1b, Cdkn1c, Cdkn2b, Cdkn2c, and Tp53 within the first pharyngeal arch. Conclusions Our results show that Hdac1 and Hdac2 function redundantly within the neural crest to regulate proliferation and the development of the pharyngeal arches via repression of cyclin-dependent kinase inhibitors.

Hedgehog signaling regulates neurogenesis in the larval and adult zebrafish hypothalamus 2. Abbreviated Title (50 character maximum) Hedgehog signaling and hypothalamic neurogenesis 3. List all Author Names and Affiliations in order as they would appear in the published article

Objective: In this study, we evaluated the feasibility of monthly insulin dose adjustments for students with type 1 diabetes mellitus (T1DM) through collaboration between pediatric diabetes clinic and school nurses. Methods: We conducted a single-arm adaptive feasibility trial with 30 students from a culturally diverse low-income community. School nurses were trained to download glucose meters and insulin pumps. Outcomes measures included the rate of glucose meter/insulin pump downloads occurred versus planned. We conducted 2 focus groups (N = 23) to seek feedback from school and clinic nurses on the collaboration and used content analysis to identify common themes. Results: The rate of glucose meter/insulin pump downloads was 27%. Feasibility obstacles were grounded in lack of time for nurses and psychosocial stressors in the community. We found a trend toward better diabetes control during the school year versus summer. We identified better communication between the school and clinic nurses and ongoing diabetes education for school nurses as strengths of the pilot. Conclusion: We propose shared clinic visits, care coordination, and behavioral health support as directions for future programs. Our findings provide directions for policy development to strengthen school nurse collaboration with diabetes clinics and improve care of students with T1DM from culturally diverse low-income communities.