Lipid composition and synthesis of HaCaT cells, an immortalized human keratinocyte line, in comparison with normal human adult keratinocytes

Abstract

Cultured keratinocytes are frequently employed for studies of epidermal lipid metabolism. Interpretation of experimental data may be complicated by donor to donor variability, the relatively short culture lifetime and variations between passages, problems that are not encountered to the same extent with immortalized cell lines. The present study was undertaken to compare the lipid composition and synthesis of normal human adult keratinocytes (NHAK) with HaCaT cells, a long-lived, spontaneously immortalized human keratinocyte line, in relation to proliferation and differentiation. No differences between the two cell types were observed: a) in total lipid content; b) in the distribution of major lipid classes during growth at 50%, 75% and 100% confluence; c) in cultures grown at 0.6 mM calcium, at which differentiation is retarded, or at 1.6 mM calcium, at which some differentiation takes place; d) in the incorporation of [14C] acetate into cellular lipids at confluence, or e) in the fatty acid composition of major cellular lipid classes. At 100% confluence NHAK and HaCaT cells differ in their cholesterol metabolism. At all stages of growth, cholesterol synthesis in HaCaT cells is more LDL-dependent than in NHAK. Furthermore, NHAK become less LDL-dependent at confluence whereas HaCaT cells do not. HaCaT cells also revealed a significantly larger fraction of phosphatidyl-ethanolamine, -serine and -inositol at 0.6 mM calcium concentration than NHAK. These findings suggest that HaCaT cells do not differentiate as well as NHAK in vitro and may therefore serve as a model for the study of lipid metabolism in cells defective in terminal differentiation.

Consistency of the Proteome in Primary Human Keratinocytes With Respect to Gender, Age, and Skin Localization

“…HaCaT cells are frequently mentioned in studies concerning cell cycle/apoptosis and lipid metabolism, as is apparent from the automated literature search. In line with previous studies, we found little alterations related to lipid metabolism (61). Similarly, protein groups related to cell cycle or apoptosis did not appear significantly regulated in our analyses, and HaCaT cells responded to H 2 O 2 treatment comparable to keratinocytes.…”

Oligo- and polysaccharides exhibit a structure-dependent bioactivity on human keratinocytes in vitro

“…It was interesting to see that exogenous polysaccharides exerted effects on the keratinocyte physiology, but that these effects were not necessarily the same between the cell line and the primary cells. This is explainable by the variances in cellular metabolism between the primary cells and keratinocytes of the cell line (Schürer et al, 1993), which for example were detected for cytokine response to irritation, too (Marionnet et al, 1997). For the same reason investigations for differentiation were only carried out with NHK; under the present culture conditions HaCaTs weren't able to differentiate.…”

Arabinogalactans from Mimosa tenuiflora (Willd.) Poiret bark as active principles for wound-healing properties: Specific enhancement of dermal fibroblast activity and minor influence on HaCaT keratinocytes

“…Further it has to be pointed out that primary cells were used in the case of fibroblasts, while HaCaT keratinocytes originated from an immortalized cell line. Differences in cell metabolism regarding to this fact were shown in recently published data (Schürer et al, 1993;Törmä et al, 1999).…”