Talin variant P229S compromises integrin activation and associates with multifaceted clinical symptoms.

Adhesion of cells to the extracellular matrix (ECM) must be exquisitely coordinated to enable development and tissue homeostasis. Cell-ECM interactions are regulated by multiple signalling pathways that coordinate the activation state of the integrin family of ECM receptors. The protein talin is pivotal in this process, and talin's simultaneous interactions with the cytoplasmic tails of the integrins and the plasma membrane are essential to enable robust, dynamic control of integrin activation and cell-ECM adhesion. Here, we report the identification of a de novo heterozygous c.685C>T (p.Pro229Ser) variant in the TLN1 gene from a patient with a complex phenotype. The mutation is located in the talin head region at the interface between the F2 and F3 domains. The characterization of this novel p.P229S talin variant reveals the disruption of adhesion dynamics that result from disturbance of the F2-F3 domain interface in the talin head. Using biophysical, computational and cell biological techniques, we find that the variant perturbs the synergy between the integrin-binding F3 and the membrane-binding F2 domains, compromising integrin activation, adhesion and cell migration. Whilst this remains a variant of uncertain significance, it is probable that the dysregulation of adhesion dynamics we observe in cells contributes to the multifaceted clinical symptoms of the patient and may provide insight into the multitude of cellular processes dependent on talin-mediated adhesion dynamics.

Impacts of Post Critical Incident Seminar on emergency service personnel: The critical incident-related experiences and psychological state.

INTRODUCTION: Post Critical Incident Seminar (PCIS) is an intervention originally developed by the Federal Bureau of Investigation (FBI) for supporting law enforcement officers who have faced critical incidents (CIs) at work. In Finland, police forces have arranged modified PCIS regularly since 2012, but the first PCIS for emergency service personnel was organized in 2020. PCIS consists of psychoeducation, peer support, and mental health professional support/Eye Movement Desensitization and Reprocessing (EMDR). Previous international studies of PCIS are scarce. Our research question was this: After 6 months, how do emergency service personnel who have participated in the PCIS describe the impacts of PCIS on experiences and psychological state evoked by the CI that was the reason to apply for it? METHODS: The data consisted of individual interviews 6 months after attending the PCIS. The number of participants in this study was 15 (94%). The data was analyzed qualitatively with inductive content analysis. RESULTS: The impacts of PCIS on incident-related experiences and state 6 months afterward were divided into five main categories: social changes, new perspectives and sensations, incident-related components, future-oriented processes, and new abilities and actions. CONCLUSIONS: PCIS can have multilevel impacts on the experiences and psychological state caused by a CI. These impacts are reflected, for example, in their inner experience, choices, emotions, actions, and relationships with others in different areas of life. As a result of PCIS, the emergency service personnel's relationship with CIs in the past and the ability to function in the future can change. Further study is needed to investigate the long-term impacts of the PCIS.

Toward Xeno-Free Differentiation of Human Induced Pluripotent Stem Cell-Derived Small Intestinal Epithelial Cells.

The small intestinal epithelium has an important role in nutrition, but also in drug absorption and metabolism. There are a few two-dimensional (2D) patient-derived induced pluripotent stem cell (iPSC)-based intestinal models enabling easy evaluation of transcellular transport. It is known that animal-derived components induce variation in the experimental outcomes. Therefore, we aimed to refine the differentiation protocol by using animal-free components. More specifically, we compared maturation of 2D-cultured iPCSs toward small intestinal epithelial cells when cultured either with or without serum, and either on Geltrex or on animal-free, recombinant laminin-based substrata. Differentiation status was characterized by qPCR, immunofluorescence imaging, and functionality assays. Our data suggest that differentiation toward definitive endoderm is more efficient without serum. Both collagen- and recombinant laminin-based coating supported differentiation of definitive endoderm, posterior definitive endoderm, and small intestinal epithelial cells from iPS-cells equally well. Small intestinal epithelial cells differentiated on recombinant laminin exhibited slightly more enterocyte specific cellular functionality than cells differentiated on Geltrex. Our data suggest that functional small intestinal epithelial cells can be generated from iPSCs in serum-free method on xeno-free substrata. This method is easily converted to an entirely xeno-free method.

Supporting emergency service workers to cope with critical incidents that can lead to psychological burden at work - developing skills in the Post Critical Incident Seminar: a qualitative interview study.

BACKGROUND: Emergency service workers face critical incidents causing psychological burden. This qualitative study investigates how attending a Post Critical Incident Seminar could affect the skills of emergency service workers to overcome incidents that can cause psychological burden at work and their consequences with the following research questions: (1) How did attending the Post Critical Incident Seminar impact the skills to overcome work incidents that can lead to psychological burden? and (2) How have these skills been manifested since attending the Post Critical Incident Seminar? METHODS: The data consists of individual interviews with fifteen emergency services workers who attended a Post Critical Incident Seminar in April 2021 in Finland. The interviews were conducted six months after the Post Critical Incident Seminar and analysed using inductive content analysis. RESULTS: The results of the first research question formed two main categories: improved performance abilities and improved self-regulation abilities. From the results of the second research question two main categories were created: new kind(s) of well-being and readiness to help. Several upper categories and sub-categories were discovered. CONCLUSIONS: Based on the results, attending a Post Critical Incident Seminar may be effective in developing skills to overcome critical incidents that can lead to psychological burden. Further follow-up studies should investigate how acquired skills from the Post Critical Incident Seminar practically affect emergency service workers and their well-being in the longer term.

The Effect of Substrate Stiffness on Elastic Force Transmission in the Epithelial Monolayers over Short Timescales.

Purpose: The importance of mechanical forces and microenvironment in guiding cellular behavior has been widely accepted. Together with the extracellular matrix (ECM), epithelial cells form a highly connected mechanical system subjected to various mechanical cues from their environment, such as ECM stiffness, and tensile and compressive forces. ECM stiffness has been linked to many pathologies, including tumor formation. However, our understanding of the effect of ECM stiffness and its heterogeneities on rapid force transduction in multicellular systems has not been fully addressed. Methods: We used experimental and computational methods. Epithelial cells were cultured on elastic hydrogels with fluorescent nanoparticles. Single cells were moved by a micromanipulator, and epithelium and substrate deformation were recorded. We developed a computational model to replicate our experiments and quantify the force distribution in the epithelium. Our model further enabled simulations with local stiffness gradients. Results: We found that substrate stiffness affects the force transduction and the cellular deformation following an external force. Also, our results indicate that the heterogeneities, e.g., gradients, in the stiffness can substantially influence the strain redistribution in the cell monolayers. Furthermore, we found that the cells' apico-basal elasticity provides a level of mechanical isolation between the apical cell-cell junctions and the basal focal adhesions. Conclusions: Our simulation results show that increased ECM stiffness, e.g., due to a tumor, can mechanically isolate cells and modulate rapid mechanical signaling between cells over distances. Furthermore, the developed model has the potential to facilitate future studies on the interactions between epithelial monolayers and elastic substrates. Supplementary Information: The online version of this article (10.1007/s12195-023-00772-0) contains supplementary material, which is available to authorized users.

Human enterovirus 71 strains in the background population and in hospital patients in Finland.

BACKGROUND: Human enterovirus 71 (HEV71) is a common cause of severe outbreaks of hand-foot- and mouth disease, aseptic meningitis and encephalitis in Asian populations but has not caused such epidemics in all populations. OBJECTIVES: To analyze the frequency of HEV71 in the background childhood population in Finland by screening in stool and serum samples and by measuring neutralizing antibodies against HEV71 in serum and to compare the genetic relationship of virus strains detected in asymptomatic children and those causing severe illness in Finland to the strains found in other countries. STUDY DESIGN: 4185 stool samples and 5686 serum samples were collected and clinical symptoms recorded from children who were observed from birth. Additional stool samples were available from four children hospitalized due to EV71 infection. Samples were screened for the presence of RNA of human enteroviruses using RT-PCR and HEV71 amplicons were identified by sequencing. Phylogenetic analyses were carried out to study genetic relationships between different virus strains. Neutralizing antibodies against HEV71 were screened from 522 children. RESULTS: A total of 0.3% of stool samples and two serum samples from healthy children were positive for HEV71 genome. 1.6% of the children had neutralizing antibodies against HEV71. Most infections were asymptomatic or mild in contrast to the clear symptoms in the children hospitalized due to HEV71. All viruses were C strains. CONCLUSIONS: HEV71 is circulating in Finland but it is rare. No clear difference was seen between strains circulating in the Finnish background population and those found in hospitalized patients or those causing severe outbreaks worldwide.