Biology subjects

Ogrodnik, M.

Publications and source records attributed to Ogrodnik, M..

3 recordsLinked to original sources

bioRxiv2022

The p-rpS6-zone delineates wounding response and the healing process

It is unknown what the spatial boundaries of tissue response to wounding are. Here we show that in mammals the ribosomal protein S6 (rpS6) is phosphorylated in response to skin injury forming a zone of activation surrounding the region of the initial insult. This p-rpS6-zone forms within minutes after wounding and is present until healing is complete. The zone encapsulates markers of the healing process, including proliferation, senescence, and angiogenesis in wounded skin. A mouse model unable to phosphorylate rpS6 shows an initial acceleration of wound closure, but results in disrupted healing. Finally, the p-rpS6-zone accurately reports on the status of dermal vasculature and the effectiveness of healing. In summary, the zone divides an otherwise homogenous tissue into regions with distinct properties.

physiology↗

bioRxiv2020

A Mental Health Paradox: Mental health was both a motivator and barrier to physical activity during the COVID-19 pandemic

The COVID-19 pandemic has impacted the mental health, physical activity, and sedentary behavior of citizens worldwide. Using an online survey with 1669 respondents, we sought to understand why and how by querying about perceived barriers and motivators to physical activity that changed because of the pandemic, and how those changes impacted mental health. Consistent with prior reports, our respondents were less physically active (aerobic activity, -11%, p <0.05; strength-based activity, -30%, p<0.01) and more sedentary (+11%, p<0.01) during the pandemic as compared to 6-months before. The pandemic also increased psychological stress (+22%, p <0.01) and brought on moderate symptoms of anxiety and depression. Respondents whose mental health deteriorated the most were also the ones who were least active (depression r = -.21, p<0.01; anxiety r = -.12, p<0.01). The majority of respondents were unmotivated to exercise because they were too anxious (+8%, p <0.01), lacked social support (+6%, p =<0.01), or had limited access to equipment (+23%, p <0.01) or space (+41%, p <0.01). The respondents who were able to stay active reported feeling less motivated by physical health outcomes such as weight loss (-7%, p<0.01) or strength (-14%, p<0.01) and instead more motivated by mental health outcomes such as anxiety relief (+14%, p <0.01). Coupled with previous work demonstrating a direct relationship between mental health and physical activity, these results highlight the potential protective effect of physical activity on mental health and point to the need for psychological support to overcome perceived barriers so that people can continue to be physically active during stressful times like the pandemic.

scientific communication and education↗

bioRxiv2018

Length-independent telomere damage drives cardiomyocyte senescence

Ageing is the biggest risk factor for cardiovascular health and is associated with increased incidence of cardiovascular disease. Cellular senescence, a process driven in part by telomere shortening, has been implicated in age-related tissue dysfunction. Here, we address the question of how senescence is induced in rarely dividing/post-mitotic cardiomyocytes and investigate if clearance of senescent cells attenuates age related cardiac dysfunction. During ageing, human and murine cardiomyocytes acquire a senescent-like phenotype characterised by persistent DNA damage at telomere regions that can be driven by mitochondrial dysfunction, and crucially can occur independently of cell-division and telomere length. Length-independent telomere damage in cardiomyocytes activates the classical senescence-inducing pathways, p21CIP and p16INK4a and results in a non-canonical senescence-associated secretory phenotype. Pharmacological or genetic clearance of senescent cells in mice alleviates myocardial hypertrophy and fibrosis, detrimental features of cardiac ageing, and promotes cardiomyocyte regeneration. Our data describes a mechanism by which senescence can occur and contribute to ageing in post-mitotic tissues.

cell biology↗