Model systems for regeneration: Xenopus.

Understanding how to promote organ and appendage regeneration is a key goal of regenerative medicine. The frog, Xenopus, can achieve both scar-free healing and tissue regeneration during its larval stages, although it predominantly loses these abilities during metamorphosis and adulthood. This transient regenerative capacity, alongside their close evolutionary relationship with humans, makes Xenopus an attractive model to uncover the mechanisms underlying functional regeneration. Here, we present an overview of Xenopus as a key model organism for regeneration research and highlight how studies of Xenopus have led to new insights into the mechanisms governing regeneration.

Foxm1 regulates neural progenitor fate during spinal cord regeneration.

Xenopus tadpoles have the ability to regenerate their tails upon amputation. Although some of the molecular and cellular mechanisms that globally regulate tail regeneration have been characterised, tissue-specific response to injury remains poorly understood. Using a combination of bulk and single-cell RNA sequencing on isolated spinal cords before and after amputation, we identify a number of genes specifically expressed in the spinal cord during regeneration. We show that Foxm1, a transcription factor known to promote proliferation, is essential for spinal cord regeneration. Surprisingly, Foxm1 does not control the cell cycle length of neural progenitors but regulates their fate after division. In foxm1-/- tadpoles, we observe a reduction in the number of neurons in the regenerating spinal cord, suggesting that neuronal differentiation is necessary for the regenerative process. Altogether, our data uncover a spinal cord-specific response to injury and reveal a new role for neuronal differentiation during regeneration.

Exploring key informants' perceptions of Covid-19 vaccine hesitancy in a disadvantaged urban community in Ireland: Emergence of a '4Cs' model.

AIM: The aim of this study was to explore key informants' views on and experiences with Covid-19 vaccine hesitancy in a Dublin community with a high concentration of economic and social disadvantage and to identify feasible, community-centred solutions for improving vaccination acceptance and uptake. METHODS: Qualitative, semi-structured interviews were carried out at a local community-centre and a central hair salon. Twelve key informants from the target community were selected based on their professional experience with vulnerable population groups: the unemployed, adults in recovery from addiction, the elderly, and Irish Travellers. Inductive thematic framework analysis was conducted to identify emergent themes and sub-themes. RESULTS: Drivers of vaccine hesitancy identified by key informants largely fell under the WHO '3Cs' model of hesitancy: lack of confidence in the vaccine and its providers, complacency towards the health risks of Covid-19, and inconvenient access conditions. Covid-19 Communications emerged as a fourth 'C' whereby unclear and negative messages, confusing public health measures, and unmet expectations of the vaccine's effectiveness exacerbated anti-authority sentiments and vaccine scepticism during the pandemic. Community-specific solutions involve the provision of accurate and accessible information, collaborating with community-based organizations to build trust in the vaccine through relationship building and ongoing dialogue, and ensuring acceptable access conditions. CONCLUSIONS: The proposed Confidence, Complacency, Convenience, Covid-19 Communications ('4Cs') model provides a tool for considering vaccine hesitancy in disadvantaged urban communities reacting to the rapid development and distribution of a novel vaccine. The model and in-depth key informants' perspectives can be used to compliment equitable vaccination efforts currently underway by public health agencies and non-governmental organizations.