Guiding cell adhesion and motility by modulating cross-linking and topographic properties of microgel arrays

Biomaterial-driven modulation of cell adhesion and migration is a challenging aspect of tissue engineering. Here, we investigated the impact of surface-bound microgel arrays with variable geometry and adjustable cross-linking properties on cell adhesion and migration. We show that cell migration is inversely correlated with microgel array spacing, whereas directionality increases as array spacing increases. Focal adhesion dynamics is also modulated by microgel topography resulting in less dynamic focal adhesions on surface-bound microgels. Microgels also modulate the motility and adhesion of Sertoli cells used as a model for cell migration and adhesion. Both focal adhesion dynamics and speed are reduced on microgels. Interestingly, Gas2L1, a component of the cytoskeleton that mediates the interaction between microtubules and microfilaments, is dispensable for the regulation of cell adhesion and migration on microgels. Finally, increasing microgel cross-linking causes a clear reduction of focal adhesion turnover in Sertoli cells. These findings not only show that spacing and rigidity of surface-grafted microgels arrays can be effectively used to modulate cell adhesion and motility of diverse cellular systems, but they also form the basis for future developments in the fields of medicine and tissue engineering

GAR22β regulates cell migration, sperm motility, and axoneme structure

© 2016 Gamper et al. Spatiotemporal cytoskeleton remodeling is pivotal for cell adhesion and migration. Here we investigated the function of Gas2-related protein on chromosome 22 (GAR22β), a poorly characterized protein that interacts with actin and microtubules. Primary and immortalized GAR22β-/- Sertoli cells moved faster than wild-type cells. In addition, GAR22β-/- cells showed a more prominent focal adhesion turnover. GAR22β overexpression or its reexpression in GAR22β-/- cells reduced cell motility and focal adhesion turnover. GAR22β-actin interaction was stronger than GAR22β-microtubule interaction, resulting in GAR22β localization and dynamics that mirrored those of the actin cytoskeleton. Mechanistically, GAR22β interacted with the regulator of microtubule dynamics end-binding protein 1 (EB1) via a novel noncanonical amino acid sequence, and this GAR22β-EB1 interaction was required for the ability of GAR22β to modulate cell motility. We found that GAR22β is highly expressed in mouse testes, and its absence resulted in reduced spermatozoa generation, lower actin levels in testes, and impaired motility and ultrastructural disorganization of spermatozoa. Collectively our findings identify GAR22β as a novel regulator of cell adhesion and migration and provide a foundation for understanding the molecular basis of diverse cytoskeleton-dependent processes

Surface Topography Guides Morphology and Spatial Patterning of Induced Pluripotent Stem Cell Colonies

The relevance of topographic cues for commitment of induced pluripotent stem cells (iPSCs) is largely unknown. In this study, we demonstrate that groove-ridge structures with a periodicity in the submicrometer range induce elongation of iPSC colonies, guide the orientation of apical actin fibers, and direct the polarity of cell division. Elongation of iPSC colonies impacts also on their intrinsic molecular patterning, which seems to be orchestrated from the rim of the colonies. BMP4-induced differentiation is enhanced in elongated colonies, and the submicron grooves impact on the spatial modulation of YAP activity upon induction with this morphogen. Interestingly, TAZ, a YAP paralog, shows distinct cytoskeletal localization in iPSCs. These findings demonstrate that topography can guide orientation and organization of iPSC colonies, which may affect the interaction between mechanosensors and mechanotransducers in iPSCs

Guidelines for DC preparation and flow cytometry analysis of mouse nonlymphoid tissues

This article is part of the Dendritic Cell Guidelines article series, which provides a collection of state-of-the-art protocols for the preparation, phenotype analysis by flow cytometry, generation, fluorescence microscopy and functional characterization of mouse and human dendritic cells (DC) from lymphoid organs and various nonlymphoid tissues. DC are sentinels of the immune system present in almost every mammalian organ. Since they represent a rare cell population, DC need to be extracted from organs with protocols that are specifically developed for each tissue. This article provides detailed protocols for the preparation of single-cell suspensions from various mouse nonlymphoid tissues, including skin, intestine, lung, kidney, mammary glands, oral mucosa and transplantable tumors. Furthermore, our guidelines include comprehensive protocols for multiplex flow cytometry analysis of DC subsets and feature top tricks for their proper discrimination from other myeloid cells. With this collection, we provide guidelines for in-depth analysis of DC subsets that will advance our understanding of their respective roles in healthy and diseased tissues. While all protocols were written by experienced scientists who routinely use them in their work, this article was also peer-reviewed by leading experts and approved by all coauthors, making it an essential resource for basic and clinical DC immunologists

Characteristics, management, and outcomes of patients with left‐sided infective endocarditis complicated by heart failure: a substudy of the ESC‐EORP EURO‐ENDO (European infective endocarditis) registry

International audienc

Predictors of embolism and death in left-sided infective endocarditis: the European Society of Cardiology EURObservational Research Programme European Infective Endocarditis registry

International audienceBackground and Aims Even though vegetation size in infective endocarditis (IE) has been associated with embolic events (EEs) and mortality risk, it is unclear whether vegetation size associated with these potential outcomes is different in left-sided IE (LSIE). This study aimed to seek assessing the vegetation cut-off size as predictor of EE or 30-day mortality for LSIE and to determine risk predictors of these outcomes. Methods The European Society of Cardiology EURObservational Research Programme European Infective Endocarditis is a prospective, multicentre registry including patients with definite or possible IE throughout 2016–18. Cox multivariable logistic regression analysis was performed to assess variables associated with EE or 30-day mortality. Results There were 2171 patients with LSIE (women 31.5%). Among these affected patients, 459 (21.1%) had a new EE or died in 30 days. The cut-off value of vegetation size for predicting EEs or 30-day mortality was >10 mm [hazard ratio (HR) 1.38, 95% confidence interval (CI) 1.13–1.69, P = .0015]. Other adjusted predictors of risk of EE or death were as follows: EE on admission (HR 1.89, 95% CI 1.54–2.33, P < .0001), history of heart failure (HR 1.53, 95% CI 1.21–1.93, P = .0004), creatinine >2 mg/dL (HR 1.59, 95% CI 1.25–2.03, P = .0002), Staphylococcus aureus (HR 1.36, 95% CI 1.08–1.70, P = .008), congestive heart failure (HR 1.40, 95% CI 1.12–1.75, P = .003), presence of haemorrhagic stroke (HR 4.57, 95% CI 3.08–6.79, P < .0001), alcohol abuse (HR 1.45, 95% CI 1.04–2.03, P = .03), presence of cardiogenic shock (HR 2.07, 95% CI 1.29–3.34, P = .003), and not performing left surgery (HR 1.30 95% CI 1.05–1.61, P = .016) (C-statistic = .68). Conclusions Prognosis after LSIE is determined by multiple factors, including vegetation size