PhD Scientific Days 2025

Poster Session III. - P: Health Sciences

Fibroblasts promote osmotic surveillance by wound-induced unique calcium patterns

Name of the presenter

Fazekas László

Institute/workplace of the presenter

Department of Physiology

Authors

László Fazekas^1,2,3, Diána Kaszás^1,2,3, Szimonetta Xénia Tamás^1,2,3, Boldizsár Vámosi^1,3, Al-Sheraji Nada Mohamed^1,3, Tamás Szöllősi¹, Vivien Mihályi¹, Paulovits Barnabás¹, Fabian Gregor Dehne^1,2,3, Klaudia Vágó-Kiss^1,2,3, Benoit Thomas Roux^1,3, Balázs Enyedi^1,2,3

1: Department of Physiology, Semmelweis University, Faculty of Medicine, Tűzoltó utca 37-47, H-1094, 7 Budapest, Hungary
2: MTA-SE Lendület Tissue Damage Research Group, Hungarian Academy of Sciences and Semmelweis 9 University, H-1094 Budapest, Hungary
3: HCEMM-SE Inflammatory Signaling Research Group, Department of Physiology, Semmelweis University, 11 H-1094 Budapest, Hungary

Text of the abstract

Effective wound healing depends on the coordinated action of multiple cell types, including fibroblasts, which are key players in tissue remodeling during the later stages of repair. However, studying fibroblast function in zebrafish has been hampered by the lack of robust, cell-type-specific genetic tools.
Here, we developed a novel fibroblast-specific promoter by combining the zebrafish integrin α11a (itga11a) promoter with the murine cFos minimal promoter. Establishing this itga11a-cFos promoter in the QF2-QUAS binary expression system allowed us to evaluate tissue-damage induced signaling pathways in fibroblasts using genetically encoded biosensors.
By expressing the GCaMP7s calcium sensor in fibroblasts we identified distinct Ca²⁺ signaling events triggered by injury and hypotonic conditions. In response to tissue damage, we observed that subcutaneous fibroblasts also actively respond to osmotic changes, displaying significantly different calcium signaling patterns compared to epithelial cells. Unlike epithelial cells, which display rapid, oscillatory calcium transients, fibroblasts respond with sustained intracellular calcium elevations, suggesting different functional roles in the wound response. While epithelial cells may initiate immediate repair mechanisms, fibroblasts likely integrate signals over longer timescales to regulate gene expression and tissue remodeling.
Furthermore, we also show that tissue damage results in the activation of the cPla2-mediated shape-sensing and nuclear swelling dependent pathway in fibroblasts.
Together, our results establish Tg(itga11a-cFos:QF2) as a powerful tool for fibroblast-specific manipulation and imaging in vivo, enabling new insights into the roles of fibroblasts during tissue damage and repair.
This research was supported by New National Excellence Program of the Ministry for Culture and Innovation of Hungary from the source of the National Research, Development and Innovation Fund (EKÖP-2024-267).