Dermal Fibroblast Function
Brian J. Nickoloff in Dermal Immune System, 2019
In the older medical literature, fibroblasts were thought of solely as having the assigned function of synthesizing components of the connective tissues of the body. Also, the matrix components (e.g., collagens, proteoglycans, and the noncollagenous structural glycoproteins) were thought to provide only structural support functions, giving an organizational framework for body organs and specialized tissues. It is now apparent that these views of fibroblasts and the connective tissue matrix were antiquated and simplistic. This chapter has as its focus a discussion of the current view of the biology and functions of dermal fibroblasts. The effects of cytokines and growth factors on the interaction of fibroblasts with the immune system, as well as their effects on fibroblast functions such as adherence, proliferation, chemotaxis, and synthesis of matrix components and matrix degrading enzymes will be reviewed.
The Immune System in Cutaneous Disease: the Search for a Mouse Model of the Immunopathology of Psoriasis
John P. Sundberg in Handbook of Mouse Mutations with Skin and Hair Abnormalities, 2020
Classical cell-mediated cytotoxicity is involved in delayed-type hypersensitivity, tumor rejection, graft rejection, viral clearance, autoimmune disease, contact hypersensitivity, and responses to intracellular organisms. Various skin cells can become targets of immunologic cellular cytotoxicity.27 The basal KC appears directly damaged in lupus erythematosus, lichen planus, contact dermatitis, and erythema multiforme. The differentiated KC is damaged in the above diseases, as well as pemphigus vulgaris, graft vs. host disease, and atopic dermatitis. Melanocytes are targets in depigmenting disorders, such as vitiligo and post-inflammatory hypopigmentation. Langerhans cells, circulating dermal leukocytes, and dermal macrophages may be targets in some diseases, but documentation has so far been difficult. In some diseases, especially the blistering diseases, the target may be structural proteins of the basement membrane zone rather than cells. Dermal fibroblasts may be targeted in fibrotic diseases, and endothelial cells in the dermis or subcutaneous tissue may be targets in vasculitis, scleroderma, and erythematosus multiforme.
Advanced Glycation Endproducts in Aging Skin
Sara C. Zapico in Mechanisms Linking Aging, Diseases and Biological Age Estimation, 2017
AGEs affect various functions of skin cells in vitro (Table 2). In human dermal fibroblasts, they decrease proliferation, inhibit collagen- and ECM protein synthesis, induce premature senescence and even apoptosis, the latter via activation of RAGE, NF-κB and the caspases-3, -8 and -9 (Alikhani et al. 2005, Ravelojaona et al. 2009). In epidermal keratinocytes, AGEs decrease cell viability and migration, lead to senescence and induce the expression of proinflammatory mediators and MMPs (Zhu et al. 2011, Berge et al. 2007). Glycation of growth factors and their receptors like bFGF and EGFR may partly mediate these effects. Moreover, AGEs seem to potentiate the cytotoxic properties of UV-light, as UVA irradiated fibroblasts (Masaki et al. 1997) and keratinocytes (Wondrak et al. 2002) exhibit decreased viability after exposure to AGEs. Finally, AGEs increase the expression of adhesion molecules like ICAM-1 in vascular endothelial cells, resulting in adhesion and invasion of inflammatory cell in the skin (Schmidt et al. 1995).
The effects of valsartan on scar maturation in an experimental rabbit ear wound model
Published in Journal of Plastic Surgery and Hand Surgery, 2020
Muzaffer Kurt, Funda Akoz Saydam, Mehmet Bozkurt, Merdan Serin, Aysel Caglar
Despite decades of research regarding molecular and cellular processes of pathological scar formation, its exact mechanisms remain unclear [1]. Experimental and clinical studies in the recent years revealed the presence of angiotensin II molecules in hypertrophic scar tissue samples and fibroblast cell cultures [2,3]. Angiotensin II receptor mRNA expression has been shown in human keratinocytes cell cultures with RT-PCR techniques [4]. In addition fibroblast cell cultures from human scar tissues have been shown to contain angiotensin II receptors [5]. Experimental studies in recent years have shown that angiotensin converting enzyme (ACE) inhibitor enalapril leads to a decrease in pathological scar formation. The cytokines which belong to the transforming growth factor (TGF)-β family plays an important role in the wound healing process and hypertrophic scarring. Dermal fibroblasts, which are responsible for the synthesis of collagen type I and extracellular matrix proteins, are stimulated by TGF-β. Angiotensin II increases TGF-β expression so ACE inhibition also inhibits TGF-β stimulation ACE inhibition causes a non-selective decrease of TGF-β including β1, β2 and β3 [6].
Differentiation and plasticity of human vascular wall mesenchymal stem cells, dermal fibroblasts and myofibroblasts: a critical comparison including ultrastructural evaluation of osteogenic potential
Published in Ultrastructural Pathology, 2019
Emanuela Pasanisi, Carmen Ciavarella, Sabrina Valente, Francesca Ricci, Gianandrea Pasquinelli
In this paper, we studied the characteristics of MSCs isolated from human vascular wall, dermal fibroblasts and myofibroblasts, firstly demonstrating that immunophenotype analysis is not per se a safe technique to distinguish among these stromal cells. In fact, the markers we used do not allow distinguishing different cytotypes, as all investigated cells express both CD44 and FSP, two markers considered relatively specific for characterizing mesenchymal stem cells and fibroblasts, respectively. The expression levels of mesenchymal markers CD90 and CD105 were identical between hVW-MSCs and WPMY-1, whereas dermal fibroblasts were completely negative. Thus, we hypothesize that dermal fibroblasts are more aged and differentiated cells. We also observed morphological differences: indeed, hVW-MSCs possess a more elongated and bipolar body when compared to fibroblasts and myofibroblasts, characterized by a more rounded appearance. We then performed specific differentiation assays to evaluate the angiogenic, adipogenic, osteogenic and anti-inflammatory capacities.
Collagen biosynthesis stimulation and anti-melanogenesis of bambara groundnut (Vigna subterranea) extracts
Published in Pharmaceutical Biology, 2020
Romchat Chutoprapat, Waraporn Malilas, Rattikarl Rakkaew, Sarinporn Udompong, Korawinwich Boonpisuttinant
Currently, naturally occurring constituents from plants have received much attention as an alternative source of raw materials for cosmetic products. Phytochemical screening of some of these plants shows the presence of several bioactive compounds including flavonoids, phenols, phenolic glycosides, saponins, tannins, xanthones, alkaloids and terpenoids saponins, justifying their potential use for antioxidants, anti-aging and anti-melanogenesis (Arung et al. 2011; Bourgeois et al. 2016; Kolakul and Sripanidkulchai 2017). Radical oxygen species (ROS) are chemically reactive molecule containing oxygen such as hydroxyl radical, peroxide and superoxide radicals. These molecules can cause severe oxidative damage to dermal collagen and elastic fibres, leading to skin aging. The use of antioxidants can counter those free radicals and retard the skin aging process (Li et al. 2018). In melanogenesis, tyrosinase is a key regulating enzyme that catalyses melanin synthesis within melanocytes (Chang 2012). Thus, the down-regulation of tyrosinase becomes the most prominent approach for anti-melanogenesis. Collagen Type I and Type III play a role in maintaining skin structure. During aging, dermal fibroblasts cannot produce collagen properly, and also can be destroyed by ROS, leading to a decrease in the collagen level; the collagen fibres begin to cross-link, resulting in loss of skin elasticity (Shoulders and Raines 2009). Thus, synthesis of collagen fibres from fibroblasts is essential for healthy and firm skin.
Related Knowledge Centers
- Epidermis
- Epithelium
- Myofibroblast
- Connective Tissue
- Dermis
- Mesenchymal Stem Cell
- Skin
- Extracellular Matrix
- Cell
- Endoplasmic Reticulum