LCP1 preferentially binds clasped αMß2 integrin and attenuates leukocyte adhesion under flow.

Integrins are α/ß heterodimers that interconvert between inactive and active states. In the active state the α/ß cytoplasmic domains recruit integrin-activating proteins and separate the transmembrane and cytoplasmic (TMcyto) domains (unclasped TMcyto). Conversely, in the inactive state the α/ß TMcyto domains bind integrin-inactivating proteins, resulting in the association of the TMcyto domains (clasped TMcyto). Here, we report the isolation of integrin cytoplasmic tail interactors using either lipid bicelle-incorporated integrin TMcyto domains (α5, αM, αIIb, ß1, ß2 and ß3 integrin TMcyto) or a clasped, lipid bicelle-incorporated αMß2 TMcyto. Among the proteins found to preferentially bind clasped rather than the isolated αM and ß2 subunits was L-plastin (LCP1, also known as plastin-2), which binds to and maintains the inactive state of αMß2 integrin in vivo and thereby regulates leukocyte adhesion to integrin ligands under flow. Our findings offer a global view on cytoplasmic proteins interacting with different integrins and provide evidence for the existence of conformation-specific integrin interactors.

Proceedings from the CIHLMU 2022 Symposium: "Availability of and Access to Quality Data in Health".

Data is an essential tool for valid and reliable healthcare management. Access to high-quality data is critical to ensuring the early identification of problems, the design of appropriate interventions, and the effective implementation and evaluation of health intervention outcomes. During the COVID-19 pandemic, the need for strong information systems and the value of producing high-quality data for timely response and tracking resources and progress have been very evident across countries. The availability of and access to high-quality data at all levels of the health systems of low and middle-income countries is a challenge, which is exacerbated by multiple parallels and poorly integrated data sources, a lack of data-sharing standards and policy frameworks, their weak enforcement, and inadequate skills among those handling data. Completeness, accuracy, integrity, validity, and timeliness are challenges to data availability and use. "Big Data" is a necessity and a challenge in the current complexities of health systems. In transitioning to digital systems with proper data standards and policy frameworks for privacy protection, data literacy, ownership, and data use at all levels of the health system, skill enhancement of the staff is critical. Adequate funding for strengthening routine information systems and periodic surveys and research, and reciprocal partnerships between high-income countries and low- and middle-income countries in data generation and use, should be prioritized by the low- and middle-income countries to foster evidence-based healthcare practices.

Molecular-scale visualization of sarcomere contraction within native cardiomyocytes.

Sarcomeres, the basic contractile units of striated muscle, produce the forces driving muscular contraction through cross-bridge interactions between actin-containing thin filaments and myosin II-based thick filaments. Until now, direct visualization of the molecular architecture underlying sarcomere contractility has remained elusive. Here, we use in situ cryo-electron tomography to unveil sarcomere contraction in frozen-hydrated neonatal rat cardiomyocytes. We show that the hexagonal lattice of the thick filaments is already established at the neonatal stage, with an excess of thin filaments outside the trigonal positions. Structural assessment of actin polarity by subtomogram averaging reveals that thin filaments in the fully activated state form overlapping arrays of opposite polarity in the center of the sarcomere. Our approach provides direct evidence for thin filament sliding during muscle contraction and may serve as a basis for structural understanding of thin filament activation and actomyosin interactions inside unperturbed cellular environments.

Proceedings from the CIH-LMU 2021 Symposium: "Global Health Perspectives: Climate Change & Migration".

Climate change shapes human migration through the interaction of environmental changes with political, social, economic, and demographic drivers of mobility. Low-and middle-income countries bear the brunt of the health impacts of climate change and migration, despite their overall low contribution to greenhouse gas emissions. The CIHLMU Symposium 2021 aimed to explore the complex interconnections between climate change, migration and health from diverse global perspectives. A number of themes, such as the relationship between climate and trade, the role of technology, and the issue of responsibility were tackled. The speakers also highlighted the need for climate resilient health-systems, gender mainstreaming in climate strategies, collaboration between the Global North and South and urgently defining the 'climate refugee'. It is crucial that the narrative around climate change moves from an environmental framing to encompass human health and migration within climate discussions and strategies.

Design of a Chemical Probe for the Bromodomain and Plant Homeodomain Finger-Containing (BRPF) Family of Proteins.

The bromodomain and plant homeodomain finger-containing (BRPF) family are scaffolding proteins important for the recruitment of histone acetyltransferases of the MYST family to chromatin. Here, we describe NI-57 (16) as new pan-BRPF chemical probe of the bromodomain (BRD) of the BRPFs. Inhibitor 16 preferentially bound the BRD of BRPF1 and BRPF2 over BRPF3, whereas binding to BRD9 was weaker. Compound 16 has excellent selectivity over nonclass IV BRD proteins. Target engagement of BRPF1B and BRPF2 with 16 was demonstrated in nanoBRET and FRAP assays. The binding of 16 to BRPF1B was rationalized through an X-ray cocrystal structure determination, which showed a flipped binding orientation when compared to previous structures. We report studies that show 16 has functional activity in cellular assays by modulation of the phenotype at low micromolar concentrations in both cancer and inflammatory models. Pharmacokinetic data for 16 was generated in mouse with single dose administration showing favorable oral bioavailability.