Transferrin receptor 1 (Tfr1) facilitates cellular iron uptake through receptor-mediated endocytosis of iron-loaded transferrin. It is expressed in the intestinal epithelium but not involved in dietary iron absorption. To investigate its role, we inactivated the Tfr1 gene selectively in murine intestinal epithelial cells. The mutant mice had severe disruption of the epithelial barrier and early death. There was impaired proliferation of intestinal epithelial cell progenitors, aberrant lipid handling, increased mRNA expression of stem cell markers, and striking induction of many genes associated with epithelial-to-mesenchymal transition. Administration of parenteral iron did not improve the phenotype. Surprisingly, however, enforced expression of a mutant allele of Tfr1 that is unable to serve as a receptor for iron-loaded transferrin appeared to fully rescue most animals. Our results implicate Tfr1 in homeostatic maintenance of the intestinal epithelium, acting through a role that is independent of its iron-uptake function.transferrin receptor | intestinal epithelium | epithelial-mesenchymal transition | homeostasis | stem cell

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Public health laboratories (PHLs) provide specialized testing services for programs focused on the prevention and control of communicable diseases, early detection of congenital disorders, testing for antimicrobial resistance, and identification of environmental contaminants, among other responsibilities. Although national public health programs and partners provide some funding support, training, and technical resources to PHLs, no dedicated funding is provided from federal programs to fully support comprehensive PHL services across the United States or the underlying infrastructure needed for PHLs to provide and ensure their core functions and capabilities. Public health laboratories have begun to rely on a “community of practice” approach to addressing various service needs by creating and formalizing regional consortia, which are organized groups of geographically clustered PHLs that share expertise, capacities, and capabilities to enhance PHL services. The number of states participating in these networks increased from 13 to 48 from 2015 to 2020, including participation by multiple local PHLs and a territorial PHL. These consortia have enabled strengthening of partnerships and collaboration among PHLs to address regional priorities and challenges. We explore the background and evolution of regional consortia, outline some of their practices and activities, review lessons learned from these successful collaborations, and discuss the positive effect they have on the national public health system.