Variation in epidermal housekeeping gene expression in different pathological states

Area of Science:

• Molecular biology
• Dermatology
• Gene expression analysis

Background:

• Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and PolyA+ RNA are commonly used as control genes in gene expression studies.
• Previous research on non-epidermal cell types indicated potential variability in control gene expression.

Purpose of the Study:

• To investigate the expression stability of GAPDH and PolyA+ RNA in normal and psoriatic human skin.
• To assess the impact of noxious stimuli on GAPDH expression in the epidermis.
• To evaluate the suitability of GAPDH as a reliable control gene for epidermal gene expression studies.

Main Methods:

• Non-radioactive in situ hybridization was employed.
• Expression of GAPDH and PolyA+ RNA was analyzed in both normal and psoriatic skin samples.
• GAPDH expression was further examined in epidermis subjected to various noxious stimuli (UV radiation, tape stripping, irritants).

Main Results:

• The expression of GAPDH and PolyA+ RNA was found to be variable in human skin.
• Expression levels of these control genes were not constant across different skin conditions and after stimuli application.
• This variability was consistent with findings in non-epidermal cell cultures.

Conclusions:

• The use of GAPDH as a control gene in Northern blotting or RT-PCR of epidermal samples may introduce errors.
• Researchers should exercise caution when interpreting gene expression data using GAPDH or similar control genes in epidermal studies.
• Further validation of control genes is recommended for accurate gene expression analysis in skin research.