Biology subjects

Croci, S.

Publications and source records attributed to Croci, S..

3 recordsLinked to original sources

bioRxiv2023

Senescent cells in Giant Cell Arteritis have inflammatory phenotype participating in tissue injury via IL-6 dependent pathways

ObjectivesAge is the strongest risk factor of Giant Cell Arteritis (GCA), implying a possible pathogenetic role of cellular senescence. To address this question, we applied an established senescence specific multi-marker algorithm in tissue artery biopsies (TABs) of GCA patients. MethodsSeventy five positive TABs from GCA patients and 22 negative from patients with Polymyalgia Rheumatica (PMR) were retrospectively retrieved and analyzed. Senescent cells and their histologic origin were identified with specific cellular markers; IL-6 and MMP-9 were investigated as components of the senescent associated secretory phenotype (SASP) by triple co-staining. GCA or PMR artery culture supernatants were applied to primary skin fibroblasts with or without IL-6 blocking agent to explore the induction of IL-6 associated cellular senescence. ResultsSenescent cells were mainly present in GCA arteries at higher proportion compared to PMR (9.50% vs 2.66% respectively, p<0.0001) and were mainly originated from fibroblasts, macrophages and endothelial cells. IL-6 was expressed by senescent fibroblasts and macrophages while MMP-9 by fibroblasts only. IL-6 positive senescent cells were associated with the extension of vascular inflammation (adventitial limited disease vs transmural inflammation: 10.02% vs 4.37% respectively, p<0.0001). GCA but not PMR artery culture supernatant could induce IL-6-associated senescence that was partially inhibited by IL-6 blockade. ConclusionsSenescent cells with inflammatory phenotype are present in GCA arteries and are associated with the tissue inflammatory bulk. These findings might suggest a potential implication in disease pathogenesis by perpetuating inflammation and affecting vascular remodeling via IL-6 dependent mechanisms.

cell biology↗

bioRxiv2023

Shifts in colour morph frequencies along an urbanisation gradient in the ground beetle Pterostichus madidus

Cities impose strong ecological constraints on many species. It is often difficult to know whether phenotypic responses to urbanisation are due to (adaptive) evolutionary responses, as opposed to e.g. plastic responses. A solution is to focus on traits for which variation is only or mostly genetic in origin, since changes are then likely to reflect evolutionary processes. For this purpose, we studied the leg-colour polymorphism of a common carabid beetle, Pterostichus madidus, along an urbanisation gradient. We observed that black-legged individuals were more frequent than red-legged individuals in urban areas. Whether these changes result from natural selection or non-selective evolutionary forces is uncertain. However, if this phenotypic change is adaptive in nature, higher urban temperatures are likely to be the driver. Specifically, our results are consistent with previous data showing that black-legged individuals have a behavioural advantage in warmer (micro)climates, and contradict the thermal melanism hypothesis that predicts they would experience stronger negative effects of higher temperatures in cities.

evolutionary biology↗

bioRxiv2021

Dispersal syndrome and landscape fragmentation in the salt-marsh specialist spider Erigone longipalpis

Dispersal and its evolution play a key role for population persistence in fragmented landscapes where habitat loss and fragmentation increase the cost of between-habitat movements. In such contexts, it is important to know how variation in dispersal and other traits is structured, and whether responses to landscape fragmentation are aligned with underlying dispersal-trait correlations, or dispersal syndromes. We therefore studied trait variation in Erigone longipalpis, a European spider species specialist of (often patchy) salt marshes. We collected spiders in two salt-marsh landscapes differing in habitat availability. We then reared lab-born spiders for two generations in controlled conditions, and measured dispersal and its association with various key traits. E. longipalpis population densities were lower in the more fragmented landscape. Despite this, we found no evidence of differences in dispersal, or any other trait we studied, between the two landscapes. While a dispersal syndrome was present at the among-individual level (dispersers were more fecund and faster growing, among others), there was no indication it was genetically driven: among-family differences in dispersal were not correlated with differences in other traits. Instead, we showed that the observed phenotypic covariations were mostly due to within-family correlations. We hypothesize that the dispersal syndrome is the result of asymmetric food access among siblings, leading to variation in development rates and carrying over to adult traits. Our results show we need to better understand the sources of dispersal variation and syndromes, especially when dispersal may evolve rapidly in response to environmental change.

ecology↗