Functional Characterization and Comparison of Intercellular Communication in Stem Cell-Derived Cardiomyocytes

One novel treatment strategy for the diseased heart focuses on the use of pluripotent stem cell-derived cardiomyocytes (SC-CMs) to overcome the heart's innate deficiency for self-repair. However, targeted application of SC-CMs requires in-depth characterization of their true cardiogenic potential in terms of excitability and intercellular coupling at cellular level and in multicellular preparations. In this study, we elucidated the electrical characteristics of single SC-CMs and intercellular coupling quality of cell pairs, and concomitantly compared them with well-characterized murine native neonatal and immortalized HL-1 cardiomyocytes. Firstly, we investigated the electrical properties and Ca2+ signaling mechanisms specific to cardiac contraction in single SC-CMs. Despite heterogeneity of the new cardiac cell population, their electrophysiological activity and Ca2+ handling were similar to native cells. Secondly, we investigated the capability of paired SC-CMs to form an adequate subunit of a functional syncytium and analyzed gap junctions and signal transmission by dye transfer in cell pairs. We discovered significantly diminished coupling in SC-CMs compared with native cells, which could not be enhanced by a coculture approach combining SC-CMs and primary CMs. Moreover, quantitative and structural analysis of gap junctions presented significantly reduced connexin expression levels compared with native CMs. Strong dependence of intercellular coupling on gap junction density was further confirmed by computational simulations. These novel findings demonstrate that despite the cardiogenic electrophysiological profile, SC-CMs present significant limitations in intercellular communication. Inadequate coupling may severely impair functional integration and signal transmission, which needs to be carefully considered for the prospective use of SC-CMs in cardiac repair.

Improving Communication in Adolescent Cancer Care: A Multiperspective Study.

BACKGROUND Professionals treating adolescents with cancer must communicate well with them and their parents. Evidence suggests that the communication needs of this population are rarely met. Skills training can improve professional communication, but has been criticized for not being based on the experience of the participants in the clinical encounter. We took a multiperspective approach, drawing on perspectives of former adolescents with cancer, patients' parents, physicians, and nurses with the aim to provide suggestions for improvement in communication in adolescent cancer care. METHODS Adolescent cancer survivors (n = 16), parents (n = 8), pediatric oncologists (n = 12), and pediatric oncology nurses (n = 18) participated in 11 focus groups. They discussed their experiences communicating with each other. Transcripts were analyzed by thematic analysis. RESULTS We identified themes within the following sections: (1) The framework in which professionals communicate with adolescents with cancer (regression in a time of detachment, adolescents' perception and knowledge of illness, cognitive versus legal maturity, "lost in transition" between pediatric and adult oncology); (2) communication difficulties between professionals and patients and parents (professionals and patients/parents identified the other party as the source of difficulties), and (3) effective professional communication (there was some overlap on how doctors and nurses should communicate, along with substantially different expectations for the two professions). CONCLUSIONS The framework within which professionals communicate, the different perspectives on the factors that make communication difficult, and the different expectations regarding good communication by doctors and nurses should be considered when communication skills training courses are developed for professionals who work in adolescent oncology.

Communication in troubled waters: responses of fish communication systems to changing environments

Fish populations are increasingly being subjected to anthropogenic changes to their sensory environments. The impact of these changes on inter- and intra-specific communication, and its evolutionary consequences, has only recently started to receive research attention. A disruption of the sensory environment is likely to impact communication, especially with respect to reproductive interactions that help to maintain species boundaries. Aquatic ecosystems around the world are being threatened by a variety of environmental stressors, causing dramatic losses of biodiversity and bringing urgency to the need to understand how fish respond to rapid environmental changes. Here, we discuss current research on different communication systems (visual, chemical, acoustic, electric) and explore the state of our knowledge of how complex systems respond to environmental stressors using fish as a model. By far the bulk of our understanding comes from research on visual communication in the context of mate selection and competition for mates, while work on other communication systems is accumulating. In particular, it is increasingly acknowledged that environmental effects on one mode of communication may trigger compensation through other modalities. The strength and direction of selection on communication traits may vary if such compensation occurs. However, we find a dearth of studies that have taken a multimodal approach to investigating the evolutionary impact of environmental change on communication in fish. Future research should focus on the interaction between different modes of communication, especially under changing environmental conditions. Further, we see an urgent need for a better understanding of the evolutionary consequences of changes in communication systems on fish diversity.