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Results for “Human dermal fibroblasts”

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PubMed1978

Development and differentiation of dermal cells in man.

Development and differentiation of the single free cells of mesenchyme and dermis of human embryos and fetuses from week 6 to term is described. From week 6 to week 14, three cell types are present: stellate general mesenchymal cells with long processes, phagocytic macrophages of probable yolk-sac origin, and a granule-secretory type of cell, which could be either a melanoblast or a mast stem cell. From week 14 to week 21, fibroblasts are numerous and active, and perineurial cells, pericytes, melanoblasts, mast cells, and Merkel cells can be individually identified. There is also present another cell type, possible of bone marrow origin, that may be ancestral to the Langerhans cell and that may be carried over into postanal dermis as the "histiocyte" or fixed dermal macrophage. From week 24 to term there is little change apart from the development of fat cells in the deeper dermis. Neither lymphocyte nor plasma cell was observed at any stage of development. These observations were used in the specification and identification of cells of fully developed postnatal dermis.

Cell Differentiation↗
PubMed1977

Differentiation in human amniotic fluid cell cultures: I: Collagen production.

The collagen produced by differentiated cells cultured from human amniotic fluid was characterized in two ways. By chain composition and by 4-hydroxyproline:3-hydroxyproline isomer ratio, the collagen synthesized by F-type (fibroblast) cells was indistinguishable from that made by cultured fetal dermal fibroblasts. The predominant cells in young amniotic fluid cultures, termed AF-type, produced collagen with a lower isomer ratio, resembling that of basement membrane collage. The chain composition, as determined by chromatography on carboxymethyl cellulose, varied for different cultures of the AF-type, but the major pattern was consistent with that of basement membrane collagen. On the basis of these characteristics, F cells are of fibroblast origin, whereas most AF cells are of a different origin either endothelial or epithelial. Other evidence (Megaw et al., 1977) suggests an epithelial origin for AF cells.

Amniotic Fluid↗
PubMed2026

Generation of an induced pluripotent stem cell line, LGMi002-A, from a Bardet-Biedl Syndrome patient with a BBS5 homozygous pathogenic variant.

The human induced pluripotent stem cell (iPSC) line, iPSC-BBS5stbg1, derived from a patient with a Bardet-Biedl Syndrome (BBS) phenotype and carrying a BBS5 homozygous pathogenic variant: c.123delA, p.Gly42Glufs*11 is described. The reprogramming of the patient's dermal fibroblasts was achieved using the non-integrative Sendai virus system delivering the OCT4, SOX2, KLF4 and c-MYC (OSKM) transcription factors. The established iPSC line iPSC-BBS5stbg1 displays typical iPSC morphology, maintains genomic stability, and demonstrates the ability to differentiate into cell types representative of the three embryonic germ layers. This iPSC line constitutes robust and relevant cellular model for studying BBS-associated disease mechanisms and ciliary dysfunction.

Humans↗
PubMed1978

Enzymatic liberation of viable cells of human skin.

To obtain viable cells from normal human skin, clostridial collagenase was used. Crude collagenase digestion of collagen fibres and basal lamina results in free dermal cells and sheets of epidermis. The collagenase was tested at various concentrations, solvents and incubation periods. The specimens digested were either split or full thickness skin of varying size. The optimal result was obtained by using small (3mm across) split skin pieces incubated in 2 mg/ml collagenase. The choice of solvent MEM, MEM supplemented with serum, and Tris buffer, was less important. 3 hours' incubation the epidermis was peeled off in sheets and finally dissociated by trypsin-EDTA. The corium was completely digested after 6 hours. After 6 hours' incubation no viable cells could be seen. The epidermal cells appeared mainly as polygonal cells of various sizes and a few little dendritic cells. The dermal cells had a heterogeneous morphology during the first weeks of cultivation. After 2 weeks the cells appeared as fibroblast-like cells.

Cell Separation↗
PubMed1978

Cytochemistry of the skin of patients with mucopolysaccharidoses.

The distribution of complex carbohydrates has been investigated at the light and electron microscope levels in sweat glands of normal subjects and patients with Hurler's or Hunter's disease. Normal sweat glands examined with a battery of light microscopic histochemical methods revealed sulphated complex carbohydrate in secretory granules of the dark cells. These granules lacked affinity for dialysed iron (DI) at the light and electron microscope levels. The DI method demonstrated acid complex carbohydrates ultrastructurally on the surface of the intercellular canaliculi and central lumen in normal sweat glands. DI-reactive acidic material, presumably of mucopolysaccharide nature, surrounded and extended between collagen bundles in the stroma of normal skin, but was absent from the band which ensheathed the sweat gland and consisted of individual rather than bundled collagen fibrils. DI-reactive mucopolysaccharide lined and partially filled vacuoles of dark cells showing a laminar distribution in vacuoles of clear cells in sweat glands of a Hunter patient. The DI method also visualized mucopolysaccharide distributed throughout vacuoles in fibroblasts of this patient. DI-reactive acid material covered the luminal surface of the sweat gland, coated collagen bundles in the stroma and spared the periglandular collagenous sheath in skin from Hurler and Hunter patients as in that from normal controls. Acid phosphatase was localized ultrastructually in vacuoles and nearby cytoplasm and on plasmalemmae of clear cells, dark cells and myoepithelial cells of sweat glands from Hurler and Hunter patients. Vacuoles of dermal fibroblasts and Schwann cells in these specimens also exhibited strong acid phosphatase activity.

Female↗
PubMed1979

Recent advances in epidermal cell cultures.

Among the many skin culture systems, three have been selected in this short review because of their specific potentials in dermatological research. H. Green cultures newborn human forsekin keratinocytes on a mouse 3T3 feeder layer. Keratinocytes grow and keratinize. The feeder cells release factor(a) which allows serial propagation of keratinocytes to be achieved. The cell yield is further increased by adding epidermal grohth factor. This system has already proved to be a potent tool for the study of keratinization at the molecular level. A. Freeman has described a system in which explants of adult human skin are cultured on the dermal aspect of dead split-thickness pig skin. Keratinocytes can be passaged several times. Their differentiation is remarkable: it includes the production of keratohyaline, membrane coating granules, pemphigus as well as pemphigoid antigens. This system is interesting in the study of epidermal morphogenesis and may be applicable to the treatment of burns. The culture of epidermal cells from adult guinea pig ear in comparison with that of dermal fibroblasts is being used to study the specificity of action of pharmacological compounds on growth and keratinization of epidermal cells. Furthermore, the isolation (and culture) of pure populations of basal cells appears as a promising approach to the study of the mechanisms which moderate epidermal cell proliferation.

Animals↗
PubMed1977

Connective tissue synthesis by cultured scleroderma fibroblasts. II. Incorporation of 3h-glucosamine and synthesis of glycosaminoglycans.

Fibroblasts from normal and scleroderma skin, grown tissue culture, were incubated with 3H-glucosamine for 24 hours. No definite trends could be established in 3H-glucosamin incorporation or glycosaminoglycan synthesis. Over 90% of the total 3H activity as well as the glycosaminoglycans synthesized were secreted into the medium. Characterization of glycosaminoglycans showed that in both the medium and cells, hyaluronic acid ins the major glycosaminoglycan in normal and scleroderma fibroblasts. In the medium, hyaluronic acid represented 87% of the total glycosaminoglycans; it was slightly decreased in the cells. Fibroblasts were compared from the upper and lower areas of the affected dermis and an uninvolved dermal area of the same scleroderma patients.

Adult↗
PubMed2002

Distinct involvement of the Jun-N-terminal kinase and NF-kappaB pathways in the repression of the human COL1A2 gene by TNF-alpha.

We used a gene knockout approach to elucidate the specific roles played by the Jun-N-terminal kinase (JNK) and NF-kappaB pathways downstream of TNF-alpha in the context of alpha(2) type I collagen gene (COL1A2) expression. In JNK1-/--JNK2-/- (JNK-/-) fibroblasts, TNF-alpha inhibited basal COL1A2 expression but had no effect on TGF-beta-driven gene transactivation unless jnk1 was introduced ectopically. Conversely, in NF-kappaB essential modulator-/- (NEMO-/-) fibroblasts, lack of NF-kappaB activation did not influence the antagonism exerted by TNF-alpha against TGF-beta but prevented repression of basal COL1A2 gene expression. Similar regulatory mechanisms take place in dermal fibroblasts, as evidenced using transfected dominant-negative forms of MKK4 and IKK-alpha, critical kinases upstream of the JNK and NF-kappaB pathways, respectively. These results represent the first demonstration of an alternate usage of distinct signaling pathways by TNF-alpha to inhibit the expression of a given gene, COL1A2, depending on its activation state.

Animals↗
PubMed1979

Fibrous papule of the face. An electron-microscopic study of two cases.

Fibrous papules on the nose from two patients were examined by electron microscopy. In each, the large characteristic dermal cells had ultrastructural features of fibroblasts, and there was no evidence of either melanocytic or Schwann cell differentiation. Banded structures (long-spacing collagen) were present in one case.

Female↗
PubMed1977

Preponderance of lysosomal bodies in cultured fibroblasts from patients with recessive epidermolysis bullosa dystrophica. An electron microscopic study.

Fibroblasts of skin explants from three normal men and six patients with recessive epidermolysis bullosa dystrophica (EBD-R) were cultured in Dulbecco's medium, grown to confluence, sectioned and studied with the electron microscope. The normal control fibroblasts from the 6th to 13th passage (secretory phase) showed irregular or lobed nuclei with centrally scattered chromatin. They also had prominent RER, Golgi complexes, variously shaped mitochondria and cytoskeletal microfibrils. Their peripheral cytoplasm exhibited many vacuoles and a small number of these were autophagic lysosomes. In addition to the ultrastructural features described in the control fibroblasts, the EBD-R cells from the 6th passage contained remarkable numbers of strongly electron dense lysosomal bodies through their entire cytoplasm with very few empty vacuoles. It is speculated that the accumulation of these lysosomes may be connected with a primary metabolic cellular defect in the dermal fibroblasts of patients with EBD-R akin to that described in mucopolysaccharide storage diseases.

Adult↗
PubMed1978

Origin of cells in human amniotic fluid cultures: ultrastructural features.

Two classes of cells can be subcultured from human amniotic fluid (F and AF). Ultrastructural features of these cultrued cells were determined using scanning and transmission electron microscopy with particular attention to extracellular material. Results obtained from these two cell types are compared to one another and to cultured human dermal fïbroblasts. The F-type cultures have an abundance of extracellular type i collagen fïbers, identical with cultured human dermal fïbroblasts. No type I collagen fïbers are seen in cultures of AF cells. Instead, fïne fïlamentous material is admixed with amorphous material adjacent to cell membranes where epithelial basement membrane glycoprotein has been localized. By scanning electron microscopy parallel arrays of cells are present at confluency of F cultures, typical of cultured dermal fïbroblasts. AF cultures show a much looser growth pattern at confluency. On the basis of accumulated evidence, we believe that F-type cells arise from fïbrous connective tissue and are fïbroblasts, whereas AF cells, the predominant type in early cultures used for prenatal genetic diagnosis, arise from fetal membranes and retain features of trophoblast.

Amniotic Fluid↗
PubMed1979

[Ultrastructural study in four cases of cutaneous xanthomas in children (author's transl)].

Three cases are associated with a Reclinghausen disease. Histological findings show typical xanthoma. Electron microscopical study indicates: --numerous intracytoplasmic lipid inclusions of various type (droplets, crystals, concentric lamellar bodies, ceroid granules) in dermal cells (histiocytic foam cells, endothelial cells, Schwann cells, fibroblasts and most cells); --large intranuclear inclusions in some histiocytes containing few lipids droplets; these figures could be compared to a slice of "petrified wood"; their significance is as yet unknown (Liesegang rings?).

Cell Nucleus↗
PubMed2026

Generation of a hiPSC from a patient with an ITSN1-associated neurodevelopmental disorder spectrum carrying biallelic c.2893_2894insA (p.Tyr965Ter) genetic variant.

De novo truncating variants in ITSN1 are implicated in neurodevelopment disorders spectrum, however, biallelic variants in ITSN1 have not been previously identified. Here we present a hiPSC line generated from a patient dermal fibroblast carrying biallelic variant, c.2893_2894insA (p.Tyr965Ter). The hiPSC line expresses core stemness markers, mycoplasma free with normal karyotype and demonstrate trilineage differentiation capacity. The hiPSC line provides a valuable in-vitro model system to investigate its role in early brain development and neurodevelopmental disorders.

Humans↗
PubMed1978

A convenient method of establishing permanent lines of xeroderma pigmentosum cells.

Nine lymphoblastoid cell lines were established after transformation by Epstein-Barr virus of peripheral lymphocytes from four xeroderma pigmentosum (XP) patients, the parents of one XP patient, and three normal donors. All these cell lines proliferate as suspension in Roswell Park Memorial Institute Medium 1640 supplemented with 20% fetal bovine serum, without detectable release of infectious Epstein-Barr virus. Some characteristics of these cell lines, such as growth rates, chromosome numbers, UV sensitivities, and activities of unscheduled DNA syntheses induced by UV, 4-nitroquinoline 1-oxide, and N-methyl-N'-nitro-N-nitrosoguanidine, were determined. Results confirm that the properties related to XP are not altered by transformation with Epstein-Barr virus and are the same in degrees of defect as are those of dermal fibroblasts from the respective individuals. These XP and normal lymphoblastoid cell lines should be especially useful for biochemical studies on the mechanism of DNA repair, because they are easy to grow in mass culture.

Autoradiography↗
PubMed1978

Actinic elastosis in black skin. A light- and electronmicroscopic study.

In 9 otherwise dermatologically normal South African Balck volunteers (1--72 years old), sunlight-exposed and non-exposed skin has been examined by light- and electronmicroscopy with special references to age-dependent and actinic alteration of dermal structures. Two 72 year old Blacks exhibited typical dermal elastosis: in 1 case to a marked extent and already detectable by lightmicroscopy, in the other case only to a mild degree. In contrast, only age-related elastic fibers were revealed in the lower dermis of sunlight-exposed skin and in all dermal layers of unexposed skin. These observations are contradictory to the general view that actinic elastosis does not occur in Blacks. The elastotic material is obviously a de-novo synthesized and secreted pathological product of chronically UV-altered fibroblasts.

Adolescent↗
PubMed1976

[Structural and biochemical alterations of human diabetic dermis studied by H-lysine incorporation and microscopy].

The alteration of the structural organization of dermal connective tissue was studied by light and electron microscopy and by biochemical techniques in normal human and in diabetic patients using skin biopsies. Part of the tissue was used for light and electron microscopy, the rest was incubated in the presence of 3H-lysine for four hours. The 3H-lysine labelled biopsies were submitted to a sequential extraction procedure in order to obtain representative macromolecular fractions containing the matrix macromolecules. The extracts were analyzed for their chemical composition and radioactivity. Electron microscopy revealed ultrastructural modifications of the fibroblasts, of the collagen and elastic fibers in the diabetic dermis. Fibroblasts contained an increased amount of electron dense deposits in the cytoplasm and dilated endoplasmic reticulum. The collagen bundles were dissociated. Elastic fibers under the epithelial basal laminae were fragmented or absent. The incorporation pattern of 3H-lysine into these macromolecular fractions was different in the normal and diabetic skin biopsies. The percentage of total radioactivity incorporated increased significantly in the 1M CaCl2 extractable fraction an in the 6M urea extractable fraction and decreased significantly in the collagenase and elastase extracts in diabetic skin biopsy. These results demonstrate the existence of morphological and biochemical alterations in diabetic connective tissue (dermis) reflecting alterations in the relative rates of synthesis and/or degradation of the intercellular matrix macromolecules as well as of their microarchitectural arrangement.

Adolescent↗