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Biomedical subjects

E A Voroteliak

Publications and source records attributed to E A Voroteliak.

15 recordsLinked to original sources
PubMed1998

[Production of recombinant human keratinocyte growth factor in Escherichia coli cells].

Here we describe the synthesis of the gene encoding human keratinocyte growth factor (hKGF) and the construction of vectors for cytoplasmic production of hKGF in Escherichia coli cells. The level of recombinant protein expression was 1-1.5% of the total cell protein. hKGF was purified to homogeneity by three-step ion-exchange and affinity chromatography. The protein is biologically active: it stimulates dose-dependent protein synthesis in cultured human epidermal keratinocytes.

Amino Acid Sequence↗
PubMedDate not supplied

[Simulation of the migration process of human epidermal keratinocytes over three-dimensional collagen gel].

We developed a novel model for studying migration of keratinocyte colonies over 3D collagen gel. It was shown that keratinocytes previously cultured on plastic and then seeded on the surface of collagen gel proliferate more actively than the primary cells. The gel density could significantly affect the morphology and migration of keratinocyte colonies. Modification of collagen gel by fibronectin-like protein or poly-L-lysine altered the morphometric parameters of colonies without significant changes in the velocity of migration.

Cell Culture Techniques↗
PubMedDate not supplied

[Fibroblasts stimulate epithelialization of collagen gel].

We studied the influence of human embryonic fibroblasts on epithelialisation of collagen gel. Introduction of the fibroblasts into the gel stimulates proliferation of keratinocytes plated on the gel surface. The presence of fibroblasts in the gel also affects the pattern of keratinocyte migration on the gel and induces pronounced polarization of the migrating colonies.

Animals↗
PubMedDate not supplied

[Structural-functional units of epidermis].

The available data suggest that epidermis is organized in discrete structural and functional units (SFUs) reproduced both in vivo and in vitro. SFUs are formed in a culture of epidermal keratinocytes by self-organization of the forming cellular elements. SFUs are capable of self-sustaining and form a niche for the stem cells. At the same time, due to the maintained asymmetric kinetics of the stem cell proliferation, SFUs serve as a barrier for their uncontrolled replication.

Animals↗
PubMedDate not supplied

[Population structure of in vitro cultured keratinocytes].

Analysis of behavior of isolated epidermal keratinocytes demonstrated two dominant processes within the first two days of cultivation: formation of cell aggregates and their adhesion to the substrate. Keratinocyte spreading increased in the attached aggregates, where densely packed and well spread cells could be recognized in the aggregate center and periphery, respectively. Cell spreading and proliferation was observed in the following days. Randomly distributed p63-positive cells amounted to 35% in the studied 2-3-day keratinocyte cultures. The process of epidermal cell aggregation was reproduced in the population of basal keratinocytes, where Ki-67-expressing cells amounted to about 20%. Single cells expressing keratin 19 were observed during cell aggregation in the secondary culture. We believe that the aggregation of cultured keratinocytes reflects the formation of structural-functional units (SFUs) in vivo. Disaggregated epidermal keratinocytes maintained the information relevant for self-assembly of three-dimensional structures capable of SFU formation after transplantation into the body.

Cell Adhesion↗
PubMedDate not supplied

[The modelling of in-vitro epidermal regeneration: the joint action of serum and epidermal growth factor].

A population of basal keratinocytes was obtained by removing suprabasal cells from multilayered cultures of human epidermal keratinocytes after their incubation in medium 199 without Ca2+, serum, and mitogens (insulin, EGF, and isoproterenol). The addition of EGF (10 ng/ml) to fresh DMEM: F12 medium with cultured basal keratinocytes stimulated [3H]thymidine incorporation into cells. Serum added to the medium also stimulated this process. However, the addition of both serum and EGF did not result in any further increase in label incorporation. It was also shown that serum promotes stratification of cultures and differentiation of basal keratinocytes, whereas EGF counteracts this effect.

Cells, Cultured↗
PubMedDate not supplied

[Alpha-fetoprotein suppresses keratinocyte proliferation in vitro].

The influence of alpha-fetoprotein (AFP) on the proliferation of human epidermal keratinocytes in vitro has been studied. AFP (1p microgram/ ml) inhibits the proliferation of keratinocytes cultivated in a serum-free medium. The addition of fetal bovine serum significantly enhances the effect of AFP in this culture. A similar effect of AFP is observed in a medium with a low content of calcium ions.

Cell Division↗
PubMedDate not supplied

[Electron microscopic study of migrating keratinocyte colonies].

Structural investigation of human migrating keratinocyte colonies in culture demonstrated cell heterogeneity in colony regions. The leading edge of the colony is surrounded by several layers of highly differentiated cells. The basal cells in the middle and front regions interplay with the help of long processes and form lamellipodia along the direction of the colony migration. Formation of the lamellipodia may be the driving force of migration. The suprabasal highly differentiated cells are elongated and flattened and form numerous desmosomes. Preserved cell contacts provide for movement of the colony as a united epithelium layer. Studies of migration of epidermal keratinocyte colonies bring light to understanding cell mechanisms of wound epithelialization and morphogenetic processes.

Cell Differentiation↗
PubMedDate not supplied

[Cell proliferation in migrating colonies of epidermoid carcinoma A-431 cells in culture].

Migrating colonies of asymmetrical shape are formed in the culture of human epidermoid carcinoma A-431 at a low density of plating. Antiproliferative factors arrest migration, thus suggesting a certain correlation between cell migration and proliferation in this culture. However, under these conditions, a certain level of proliferation can be retained upon complete suppression of migration. Radioautographic studies did not reveal unequal distribution of the labelled cells were also in migrating colonies. Upon suppression and subsequent stimulation of migration, the labelled cells were also distributed equally in most colonies. Thus, the capacity of colonies for migration does not depend on cell proliferation in a certain part of the colony, but is determined by the proliferative potential of the entire colony. The influence of cell position in the colony on the cell cycle length remains unclear. Actively migrating colonies are capable of DNA synthesis, thus suggesting that proliferation and migration are fully compatible in individual cells.

Autoradiography↗
PubMedDate not supplied

[The action of epidermal growth factor on the migration of A-431 cells].

It has been demonstrated that the epidermal growth factor (EGF) stimulates migration of A-431 cells into the wound created in a monolayer in the absence of any significant effect on the incorporation of labeled thymidine into cells. The effect of EGF on migration is stimulated by the simultaneous addition of insulin. Cell treatment with mitomycin C completely eliminates the stimulating effect of EGF, without, however, affecting baseline level of cell migration, which is independent on growth stimulants. These results lead to the conclusion that the effect of EGF on cell migration and cell proliferation in A-431 culture can be partially separated.

Antibiotics, Antineoplastic↗