A pharmacy liaison-patient navigation intervention to reduce inpatient and emergency department utilization among primary care patients in a Medicaid accountable care organization: A pragmatic trial protocol.

OBJECTIVE: To determine whether employing the services of a pharmacy liaison to promote medication adherence (usual care), relative to a pharmacy liaison with training in motivational interviewing and as a patient navigator who systematically screens for health-related social needs and provides targeted navigation services to connect patients with appropriate community resources in partnership with a community-based organization (enhanced usual care), will reduce inpatient hospital admissions and emergency department visits among patients who are members of a Medicaid ACO and receive primary care at a large urban safety-net hospital. BACKGROUND: Prior studies have demonstrated only modest effects in reducing utilization among safety-net patient populations. Interventions that address health-related social needs have the potential to reduce utilization in these populations. DESIGN/METHODS: Assignment to treatment condition is by medical record number (odd vs. even) and is unblinded (NCT03919084). Adults age 18-64 within the 3rd to 10th percentile for health care utilization and cost among Medicaid Accountable Care Organization membership attending a primary care visit in the general internal medicine practice at Boston Medical Center enrolled. DISCUSSION: Our study will advance the field in two ways: 1) by providing evidence about the effectiveness of pharmacy liaisons who also function as patient navigators; and 2) by de-implementing patient navigators. Patients in the enhanced usual care arm will no longer receive the services of a clinic-based patient navigator. In addition, our study includes a novel collaboration with a community-based organization, and focuses on an intermediate-cost patient population, rather than the most costly patient population.

BMPs: from bone to body morphogenetic proteins.

The family of bone morphogenetic proteins (BMPs) comprises approximately 30 secreted cytokines that signal through transmembrane serine/threonine kinase receptors. The BMP signaling pathways are fine-tuned on multiple levels: Extracellular antagonists modify ligand activity; several co-receptors enhance or inhibit downstream signaling events through multiple mechanisms; and intracellular molecules further regulate the signaling outcome and mediate crosstalk with other pathways. BMPs affect structures and processes throughout the entire body, ranging from embryonic patterning and development through stem cells and their niches, to tissue homeostasis and regeneration. This comprehensive involvement in various tissues had not been expected by Marshall Urist, who initially discovered the ability of an unknown factor in bone to induce bone growth in muscle and subsequently suggested the name "bone morphogenetic protein." Today, recombinant BMPs are used in clinical practice for the treatment of bone and kidney disorders, and new genetically modified BMPs are emerging as promising tools in regenerative medicine and tissue engineering. Clearly, the functions of BMPs within the body are more versatile than initially suspected. To discuss modern trends in BMP signaling, leaders in the field met for the First International BMP Workshop in Berlin in September 2009. Here, we summarize new insights on the roles of BMPs in various tissues and highlight recent findings in cell, structural, and developmental biology as well as the therapeutic potential of BMPs. Finally, we conclude that BMPs today deserve to be called body morphogenetic proteins.

Recent advances in BMP receptor signaling.

Bone Morphogenetic Proteins (BMPs) play an important role during organ development and during regeneration after tissue damage. BMPs signal via transmembrane serine/threonine kinase receptors. From our current understanding heteromeric complexes of type I and type II receptors are required for signal propagation. Presently, three type I and three type II receptors are known to bind BMPs with different affinities. Ligands and receptors eventually oligomerize via defined modes into signaling complexes. Co-receptors recruit into these complexes to either inhibit or to promote signaling. The Smad pathway, initiated by phosphorylation through the activated type I receptors, results in transcriptional regulation of early target genes. However, on its way to the nucleus, Smads represent signaling platforms for other pathways, which eventually finetune BMP signal transduction. We also describe BMP-induced signaling cascades leading to cytoskeletal rearrangements, non-transcriptional and non-Smad pathways. BMPs induce a plethora of different cellular effects ranging from stem cell maintenance, migration, differentiation, proliferation to apoptosis. The molecular mechanism, by which the same ligand induces these manifold effects, depends on the cellular context. Here we try to give a current picture of the most important players in regulating and directing BMP signaling towards the desired cellular outcome. Examples of BMP action during development, but also physiological and pathophysiological conditions in the adult organism are presented.

Biochemical and functional characterization of the Ror2/BRIb receptor complex.

Ror2 belongs to the Ror family of receptor tyrosine kinases. Two distinct human disorders result from mutations in Ror2 suggesting a role in cartilage formation, chondrocyte differentiation, and joint formation. We have previously demonstrated functional and physical association of Ror2 with the BMP receptor type Ib (BRIb). The interaction site was mapped to the extracellular CRD domain of Ror2. Here we show specific association with and transphosphorylation by BRIb, but not BMP receptors Ia or II. This association is independent of N-glycosylation, excluding the possibility that the interaction is mediated by carbohydrate moieties present in the CRD region of Ror2. The Ror2/BRIb complex proved very stable under high ionic and reducing conditions, yet it appeared sensitive to SDS-treatment. Besides we provide evidence that the Ror2/BRIb complex forms in distinct microdomains at the plasma membrane (DRMs), indicating that Ror2 may interfere with BMP signaling complexes within these membrane domains.

Monomeric and dimeric GDF-5 show equal type I receptor binding and oligomerization capability and have the same biological activity.

Growth and differentiation factor 5 (GDF-5) is a homodimeric protein stabilized by a single disulfide bridge between cysteine 465 in the respective monomers, as well as by three intramolecular cysteine bridges within each subunit. A mature recombinant human GDF-5 variant with cysteine 465 replaced by alanine (rhGDF-5 C465A) was expressed in E. coli, purified to homogeneity, and chemically renatured. Biochemical analysis showed that this procedure eliminated the sole interchain disulfide bond. Surprisingly, the monomeric variant of rhGDF-5 is as potent in vitro as the dimeric form. This could be confirmed by alkaline phosphatase assays and Smad reporter gene activation. Furthermore, dimeric and monomeric rhGDF-5 show comparable binding to their specific type I receptor, BRIb. Studies on living cells showed that both the dimeric and monomeric rhGDF-5 induce homomeric BRIb and heteromeric BRIb/BRII oligomers. Our results suggest that rhGDF-5 C465A has the same biological activity as rhGDF-5 with respect to binding to, oligomerization of and signaling through the BMP receptor type Ib.

Modulation of GDF5/BRI-b signalling through interaction with the tyrosine kinase receptor Ror2.

The brachydactylies are a group of inherited disorders of the hands characterized by shortened digits. Mutations in the tyrosine kinase receptor Ror2 cause brachydactyly type B (BDB). Mutations in GDF5, a member of the BMP/TGF-beta ligand family, cause brachydactyly type C (BDC) whereas mutations in the receptor for GDF5, BRI-b, cause brachydactyly type A2 (BDA2). There is considerable degree of phenotypic overlap between the subtypes BDB, BDC and BDA2. Here we demonstrate that all three components are involved in GDF5 induced regulation of chondrogenesis. We show that Ror2 (tyrosine kinase receptor) and BRI-b (serine/threonine kinase receptor) form a ligand independent heteromeric complex. The frizzled-like-CRD domain of Ror2 is required for this complex. Within that complex Ror2 gets transphosphorylated by BRI-b. We show that Ror2 modulates GDF5 signalling by inhibition of Smad1/5 signalling and by activating a Smad-independent pathway. Both pathways however, are needed for chondrogenic differentiation as demonstrated in ATDC5 cells. The functional interaction of Ror2 with GDF5 and BRI-b was genetically confirmed by the presence of epistatic effects in crosses of Ror2, BRI-b and Gdf5 deficient mice. These results indicate for the first time a direct interaction of Ser/Thr- and Tyr-Kinase receptors and provide evidence for modulation of the Smad-pathway and GDF5 triggered chondrogenesis.