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Author Spotlight: Dendritic Cells Maturation Using Sialidases-Based Enzymatic Treatment of the Cell Surface
Published on: October 20, 2023
Sialylation regulates myofibroblast differentiation of human skin fibroblasts
Norihiko Sasaki1, Yoko Itakura1, Masashi Toyoda2
1Research Team for Geriatric Medicine (Vascular Medicine), Tokyo Metropolitan Institute of Gerontology, Sakaecho 35-2, Itabashi-ku, Tokyo, 173-0015, Japan.
Background:
Fibroblasts are key players in maintaining skin homeostasis and in orchestrating physiological tissue repair and skin regeneration. Dysfunctions in fibroblasts that occur with aging and the senescent process lead to the delayed healing observed in elderly people. The molecular mechanisms leading to fibroblast dysfunction during aging and the senescent process have not yet been clarified. Previously, changes in patterns of glycosylation were observed in fibroblasts in aging and the senescent process, but the effect of these changes on the function of fibroblasts has not been well documented. Here, we investigated whether changes in glycosylation during the process to senescence may have functional effects on fibroblasts.
Methods:
The changes in cell surface glycans on skin fibroblasts during the process to senescence were examined in early-passage (EP) and late-passage (LP) skin fibroblasts by fluorescence-activated cell sorting analysis using lectins. The contributors to the changes in cell surface glycans were examined by real-time polymerase chain reaction or Western blot analysis. The effects of changes in glycosylation on proliferation, migration, induction of cellular senescence, and myofibroblast differentiation induced by transforming growth factor (TGF)-β1 stimulation were examined in EP fibroblasts. The changes in glycosylation were performed by GalNAc-α-O-benzyl or sialidase treatment.
Results:
A decrease in sialylation of glycoproteins and an increase in sialidase NEU1 were observed in LP fibroblasts. The reduction of sialylation did not have any effect on proliferation, migration, or induction of cellular senescence. On the other hand, myofibroblast differentiation was inhibited by the reduction of sialylation, indicating that sialylation is important for myofibroblast differentiation. The localization of CD44 in lipid rafts, which is required for myofibroblast differentiation, was inhibited by the reduction of sialylation. Furthermore, reduced myofibroblast differentiation in LP fibroblasts was restored by a sialidase inhibitor.
Conclusions:
Desialylation of CD44 with increased sialidase during the process to senescence reduced the localization of CD44 in lipid rafts after TGF-β1 stimulation, leading to the inhibition of myofibroblast differentiation. Thus, regulation of sialylation may be an attractive strategy for the prevention and regenerative therapy of age-related skin diseases, cosmetic skin alterations, and chronic wounds caused by delayed healing in elderly people.
Insights
Aging reduces skin fibroblast sialylation, inhibiting myofibroblast differentiation. Restoring sialylation may offer therapeutic strategies for age-related skin conditions and wound healing.
Area of Science:
- Biochemistry
- Dermatology
- Cell Biology
Background:
- Fibroblasts are crucial for skin homeostasis, repair, and regeneration.
- Aging-associated fibroblast dysfunction contributes to delayed wound healing in the elderly.
- Molecular mechanisms of age-related fibroblast dysfunction, particularly glycosylation changes, remain unclear.
Purpose of the Study:
- To investigate the functional impact of glycosylation changes on skin fibroblasts during senescence.
- To determine if altered glycosylation affects fibroblast proliferation, migration, senescence, and myofibroblast differentiation.
Main Methods:
- Compared cell surface glycans in early-passage (EP) and late-passage (LP) skin fibroblasts using fluorescence-activated cell sorting and lectins.
- Analyzed glycan changes using real-time PCR and Western blot.
- Assessed functional effects on EP fibroblasts via proliferation, migration, senescence induction, and transforming growth factor (TGF)-β1-induced myofibroblast differentiation, manipulating glycosylation with GalNAc-α-O-benzyl or sialidase treatment.
Main Results:
- Late-passage fibroblasts showed decreased sialylation and increased sialidase NEU1.
- Reduced sialylation did not affect proliferation, migration, or senescence induction.
- Myofibroblast differentiation was inhibited by reduced sialylation, linked to impaired CD44 localization in lipid rafts.
- Sialidase inhibition restored myofibroblast differentiation in late-passage fibroblasts.
Conclusions:
- Desialylation of CD44 in senescent fibroblasts impairs TGF-β1-induced myofibroblast differentiation by affecting CD44 localization.
- Sialylation regulation presents a potential therapeutic avenue for age-related skin diseases, cosmetic concerns, and chronic wound healing.
