Young Skin or when the Cell Nucleus can communicate with the Cytoplasm (Cytosol)

• The nuclear membrane separates the nucleus from the cytosol (cytoplasm)
  • several proteins shape are part of its different layers.
  • its role is to maintain mRNA and protein trafficking
  • Lamin A and C are 2 of the main proteins. Its coding gene LMNA is mutated in the premature aging syndrome called the Hutchinson-Gilford progeria syndrome

• Progerin (mutated lamin A) is present in intrinsically aged skin and in UVA-irradiated fibroblasts. Its expression is influenced by  mechanical stress (gravity, physical activity, daily facial expression)

• Results show:
  • increased progerin expression as well as fibroblasts with an abnormal nuclear shape (using stretched collagen-coat silicon membrane flexible chamber).
  • Upregulation of MMP 1, 2 , 3, 11 and 15
  • disturbed nuclear function as proteins regulating exportation of proteins from the nucleus (Nuclear pore complex proteins, TPR and NUP153) were aggregated (fluorescence after immunohistochemistry)
  • Increased Accumulation of NFkB
  • Moreover, areas exposed to mechanical stress such as Crow’s feet showed increase TNF alpha expression and CD15 positive inflammatory cells (immunohistochemistry)

The authors conclude by suggesting the relationship between skin aging and an abnormal nuclear membrane.

Contributors

Dr Christophe Hsu – dermatologist. Geneva, Switzerland

Source of information: P03-09 Takeuchi H et al. Mechanical stress-induced nuclear dysfunction, exacerbating inflammatory response against external stimuli in human dermal fibroblasts. JSID Annual Meeting (Japanese Society of Investigative Dermatology, 日本研究皮膚科学会) 2014 – Osaka, Japan