Differentiation capacity of stromal fibroblast-like cells from human bone marrow, adipose tissue, hair follicle dermal papilla and derma

We compared the morphology and differentiation capacity of human stromal cells derived from bone marrow (BMSC), adipose tissue (ATSC), hair follicle dermal papilla (DPC) and dermal fibroblasts (DFb). All cells have fibroblast-like morphology. ATSC and DPC cells expressed stem cell the surface markers CD105, CD49d, and STRO-1, which were revealed immunocytochemically. CD49d was not found on BMSC. The low expression of CD49d and STRO-1 was registered in the DFb population. ATSC, BMSC, and DPC have similar capacities for adipo- and osteogenic differentiation. These cells, cultured in appropriate induction media, alter the phenotype and synthesize specific proteins. However, the expression of differentiation in the DPC population is lower than in ATSC and BMSC cultures. We propose that these cell populations have primitive progenitor cells with properties of mesenchymal stem cells.     

Capability of cultivated human hair-follicle cells to integrate with skin structure in vivo

In the present work, we labeled human epidermal keratinocytes and dermal papilla cells in order to study their behavior after intradermal transplantation. The cells were transduced by lentiviral vectors that bore a marker gene that encodes green fluorescent protein (copGFP) or red fluorescent protein (DsRed). A portion of the transgene expressing cells was evaluated by flow cytometry. The proposed genetic constructions have allowed one to achieve high efficiency (>95%) of the transduction of hair follicle cells. The in vitro transduced cells were injected under epidermis of human skin fragments, after which these fragments were transplanted under the skin of immunodeficient mice. The injected epidermal keratinocytes were found mainly in hair follicles and partially in the zone of interfollicular epidermis, while dermal papilla cells were found in the papilla of the derma. The results of the present study have shown that the chosen genetic constructions obtained based on human immunodeficiency lentivirus are capable of the effective and stable transduction of human skin cells. The injected cells survived and were found in the corresponding skin structures.     

Structural–Functional Units of Epidermis

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

Population Structure of <Emphasis Type="Italic">in Vitro</Emphasis> 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.     

Dopamine disorganizes direct intercellular interactions in keratinocytes cultures: A comparison to hepatocytes

Dopamine in the concentration 0.4 μg/mL abolishes protein synthesis rhythm in HaCaT keratinocytes and hepatocytes unlike noradrenaline or melatonin, which synchronize direct intercellular interactions and organize protein synthesis rhythm. Experiments with D2 dopamine receptors blocking agent metoclopramide (tserukal) in the concentration 2 μg/mL show that a disorganizing effect of dopamine is driven by the activation of D2 receptors, which block adenylyl cyclase and the efflux of calcium ions from internal depos according to the literature. It is shown that tserukal does not activate serotonin receptors in our experimental settings. Cellular interactions’ recovery during or after dopamine action is carried out by melatonin in the concentration 0.001 μg/mL. A recommendation to inject melatonin before dopamine administration for different medical indications is discussed.     

Wal Mutant Mice Have a Mutation Associated with Autism Spectrum Disorders

Doklady Biological Sciences - The waved alopecia (wal) mutation arose spontaneously in mice. Phenotypically, the wal mutation in a homozygous recessive state is manifested by a wavy coat. Over...