TY - JOUR
T1 - p16Ink4a-induced senescence in cultured mast cells as a model for ageing reveals significant morphological and functional changes
AU - Kleeblatt, Elisabeth
AU - Lazki-Hagenbach, Pia
AU - Nabet, Ellon
AU - Cohen, Reli
AU - Bahri, Rajia
AU - Rogers, Nicholas
AU - Langton, Abigail
AU - Bulfone-Paus, Silvia
AU - Frenkel, Dan
AU - Sagi-Eisenberg, Ronit
N1 - Publisher Copyright:
© The Author(s) 2024.
PY - 2024/12
Y1 - 2024/12
N2 - Background: Mast cells (MCs) are tissue resident cells of the immune system, mainly known for their role in allergy. However, mounting evidence indicates their involvement in the pathology of age-related diseases, such as Alzheimer’s disease, Parkinson’s disease, and cancer. MC numbers increase in aged tissues, but how ageing affects MCs is poorly understood. Results: We show that MC ageing is associated with the increased expression of the cell cycle inhibitor p16 Ink4a, a marker and inducer of cellular senescence. Relying on this observation and the tight association of ageing with senescence, we developed a model of inducible senescence based on doxycycline-induced expression of p16Ink4a in cultured bone marrow derived MCs (BMMCs). Using this model, we show that senescent MCs upregulate IL-1β, TNF-α and VEGF-A. We also demonstrate that senescence causes marked morphological changes that impact MC function. Senescent MCs are larger, contain a larger number of secretory granules (SGs) and have less membrane protrusions. Particularly striking are the changes in their SGs, reflected in a significant reduction in the number of electron dense SGs with a concomitant increase in lucent SGs containing intraluminal vesicles. The changes in SG morphology are accompanied by changes in MC degranulation, including a significant increase in receptor-triggered release of CD63-positive extracellular vesicles (EVs) and the exteriorisation of proteoglycans, as opposed to a gradual inhibition of the release of β-hexosaminidase. Conclusions: The inducible expression of p16Ink4a imposes MC senescence, providing a model for tracking the autonomous changes that occur in MCs during ageing. These changes include both morphological and functional alterations. In particular, the increased release of small EVs by senescent MCs suggests an enhanced ability to modulate neighbouring cells.
AB - Background: Mast cells (MCs) are tissue resident cells of the immune system, mainly known for their role in allergy. However, mounting evidence indicates their involvement in the pathology of age-related diseases, such as Alzheimer’s disease, Parkinson’s disease, and cancer. MC numbers increase in aged tissues, but how ageing affects MCs is poorly understood. Results: We show that MC ageing is associated with the increased expression of the cell cycle inhibitor p16 Ink4a, a marker and inducer of cellular senescence. Relying on this observation and the tight association of ageing with senescence, we developed a model of inducible senescence based on doxycycline-induced expression of p16Ink4a in cultured bone marrow derived MCs (BMMCs). Using this model, we show that senescent MCs upregulate IL-1β, TNF-α and VEGF-A. We also demonstrate that senescence causes marked morphological changes that impact MC function. Senescent MCs are larger, contain a larger number of secretory granules (SGs) and have less membrane protrusions. Particularly striking are the changes in their SGs, reflected in a significant reduction in the number of electron dense SGs with a concomitant increase in lucent SGs containing intraluminal vesicles. The changes in SG morphology are accompanied by changes in MC degranulation, including a significant increase in receptor-triggered release of CD63-positive extracellular vesicles (EVs) and the exteriorisation of proteoglycans, as opposed to a gradual inhibition of the release of β-hexosaminidase. Conclusions: The inducible expression of p16Ink4a imposes MC senescence, providing a model for tracking the autonomous changes that occur in MCs during ageing. These changes include both morphological and functional alterations. In particular, the increased release of small EVs by senescent MCs suggests an enhanced ability to modulate neighbouring cells.
KW - Ageing
KW - Exosomes
KW - Mast cells
KW - Secretory granules
KW - Senescence
KW - p16
UR - http://www.scopus.com/inward/record.url?scp=85210167901&partnerID=8YFLogxK
U2 - 10.1186/s12979-024-00478-5
DO - 10.1186/s12979-024-00478-5
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C2 - 39529115
AN - SCOPUS:85210167901
SN - 1742-4933
VL - 21
JO - Immunity and Ageing
JF - Immunity and Ageing
IS - 1
M1 - 77
ER -