CAN THE AGEING SCALP DERMAL FIBROBLAST INFLAMMATORY PHENOTYPE BE REVERSED?
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Presented by: Richard Baker
We have previously reported significant age-related changes in situ in female scalp, as well as significant changes in dermal fibroblasts (DF) cultured from the same donors, including an altered secretome. In ageing scalp, the switch to a more inflammatory DF population may compromise the dermal environment, significantly impacting on hair follicle maintenance and growth. Here, we have expanded our proteomic analysis, comparing the proteome of DFs cultured from female scalp of young (under 30 years) and older cohorts (over 50 years). We have assessed their inflammatory profile and investigated if the aged phenotype is reversed via the secretome of younger DFs.
Scalp DFs were isolated from female donors aged 20-29 years (n=4) and 53-57 years (n=4). Cellular lysates were evaluated by LC-MS proteomics and compared by MS1 precursor intensities using PEAKS software, to compare changes in the proteome with age. DF conditioned medium was collected for each donor and used to treat older DFs (n=4) for 14 days to establish the impact of young vs. old secretome on their inflammatory profile. After a 14-day exposure to conditioned medium, DF cell lysates were pooled and relative expression of 105 different cytokine markers simultaneously quantitated with a Proteome Profiler Human XL Cytokine Array Kit (R&D systems).
Proteomic analysis of the two different DF cohorts detected a significant difference (Quant threshold at 5% FDR = Significance >31.49) in 11 proteins with age. Nine of these were significantly higher in the older cohort, while two were significantly lower in the older cohort. Cultured DFs also displayed an altered inflammatory profile with age, demonstrating an increased expression of 13 inflammatory proteins. When older DFs (n=4) were treated with conditioned medium originating from younger DFs (n=4), expression of two of these 13 proteins reverted to the lower levels seen in the young cohort. However, incubation of the same DFs with conditioned medium collected from the older cohort (n=4) induced an increase in the expression of six of these proteins above that expressed in the older DFs incubated with the control, non-conditioned medium.
This data provides further evidence that ageing female scalp DFs exhibit significant differences in their proteome and specific inflammatory proteins correlated with aging-associated signaling pathways, e.g., TGF-β, thrombin/SERPIN and MMPs. Some age-related inflammatory changes were partly reversible via the secretome of younger cells. Further studies investigating how these changes impact hair follicle fibroblasts and the dermal hair follicle environment will be important to further our understanding hair ageing.
Scalp DFs were isolated from female donors aged 20-29 years (n=4) and 53-57 years (n=4). Cellular lysates were evaluated by LC-MS proteomics and compared by MS1 precursor intensities using PEAKS software, to compare changes in the proteome with age. DF conditioned medium was collected for each donor and used to treat older DFs (n=4) for 14 days to establish the impact of young vs. old secretome on their inflammatory profile. After a 14-day exposure to conditioned medium, DF cell lysates were pooled and relative expression of 105 different cytokine markers simultaneously quantitated with a Proteome Profiler Human XL Cytokine Array Kit (R&D systems).
Proteomic analysis of the two different DF cohorts detected a significant difference (Quant threshold at 5% FDR = Significance >31.49) in 11 proteins with age. Nine of these were significantly higher in the older cohort, while two were significantly lower in the older cohort. Cultured DFs also displayed an altered inflammatory profile with age, demonstrating an increased expression of 13 inflammatory proteins. When older DFs (n=4) were treated with conditioned medium originating from younger DFs (n=4), expression of two of these 13 proteins reverted to the lower levels seen in the young cohort. However, incubation of the same DFs with conditioned medium collected from the older cohort (n=4) induced an increase in the expression of six of these proteins above that expressed in the older DFs incubated with the control, non-conditioned medium.
This data provides further evidence that ageing female scalp DFs exhibit significant differences in their proteome and specific inflammatory proteins correlated with aging-associated signaling pathways, e.g., TGF-β, thrombin/SERPIN and MMPs. Some age-related inflammatory changes were partly reversible via the secretome of younger cells. Further studies investigating how these changes impact hair follicle fibroblasts and the dermal hair follicle environment will be important to further our understanding hair ageing.