scholarly journals Regulation of epithelial–mesenchymal IL-1 signaling by PPARβ/δ is essential for skin homeostasis and wound healing

2009 ◽  
Vol 184 (6) ◽  
pp. 817-831 ◽  
Author(s):  
Han Chung Chong ◽  
Ming Jie Tan ◽  
Virginie Philippe ◽  
Siew Hwey Tan ◽  
Chek Kun Tan ◽  
...  

Skin morphogenesis, maintenance, and healing after wounding require complex epithelial–mesenchymal interactions. In this study, we show that for skin homeostasis, interleukin-1 (IL-1) produced by keratinocytes activates peroxisome proliferator–activated receptor β/δ (PPARβ/δ) expression in underlying fibroblasts, which in turn inhibits the mitotic activity of keratinocytes via inhibition of the IL-1 signaling pathway. In fact, PPARβ/δ stimulates production of the secreted IL-1 receptor antagonist, which leads to an autocrine decrease in IL-1 signaling pathways and consequently decreases production of secreted mitogenic factors by the fibroblasts. This fibroblast PPARβ/δ regulation of the IL-1 signaling is required for proper wound healing and can regulate tumor as well as normal human keratinocyte cell proliferation. Together, these findings provide evidence for a novel homeostatic control of keratinocyte proliferation and differentiation mediated via PPARβ/δ regulation in dermal fibroblasts of IL-1 signaling. Given the ubiquitous expression of PPARβ/δ, other epithelial–mesenchymal interactions may also be regulated in a similar manner.

2001 ◽  
Vol 154 (4) ◽  
pp. 799-814 ◽  
Author(s):  
Liliane Michalik ◽  
Béatrice Desvergne ◽  
Nguan Soon Tan ◽  
Sharmila Basu-Modak ◽  
Pascal Escher ◽  
...  

We show here that the α, β, and γ isotypes of peroxisome proliferator–activated receptor (PPAR) are expressed in the mouse epidermis during fetal development and that they disappear progressively from the interfollicular epithelium after birth. Interestingly, PPARα and β expression is reactivated in the adult epidermis after various stimuli, resulting in keratinocyte proliferation and differentiation such as tetradecanoylphorbol acetate topical application, hair plucking, or skin wound healing. Using PPARα, β, and γ mutant mice, we demonstrate that PPARα and β are important for the rapid epithelialization of a skin wound and that each of them plays a specific role in this process. PPARα is mainly involved in the early inflammation phase of the healing, whereas PPARβ is implicated in the control of keratinocyte proliferation. In addition and very interestingly, PPARβ mutant primary keratinocytes show impaired adhesion and migration properties. Thus, the findings presented here reveal unpredicted roles for PPARα and β in adult mouse epidermal repair.


1999 ◽  
Vol 112 (12) ◽  
pp. 1843-1853 ◽  
Author(s):  
N. Maas-Szabowski ◽  
A. Shimotoyodome ◽  
N.E. Fusenig

Epithelial-mesenchymal interactions play an important role in regulating tissue homeostasis and repair. For skin, the regulatory mechanisms of epidermal-dermal interactions were studied in cocultures of normal human epidermal keratinocytes (NEK) and dermal fibroblasts (HDF) rendered postmitotic by alpha-irradiation (HDFi). The expression kinetics of different cytokines and their receptors with presumed signalling function in skin were determined at the RNA and protein level in mono- and cocultured NEK and HDFi. In cocultured HDFi, mRNA and protein synthesis of keratinocyte growth factor (KGF) (FGF-7) was strongly enhanced, whereas in cocultured keratinocytes interleukin (IL)-1alpha and -1beta mRNA expression increased compared to monocultures. Thus we postulated that IL-1, which had no effect on keratinocyte proliferation, induced in fibroblasts the expression of factors stimulating keratinocyte proliferation, such as KGF. The functional significance of this reciprocal modulation was substantiated by blocking experiments. Both IL-1alpha and -1beta-neutralizing antibodies and IL-1 receptor antagonist significantly reduced keratinocyte proliferation supposedly through abrogation of KGF production, because IL-1 antibodies blocked the induced KGF production. These data indicate a regulation of keratinocyte growth by a double paracrine mechanism through release of IL-1 which induces KGF in cocultured fibroblasts. Thus IL-1, in addition to its proinflammatory function in skin, may play an essential role in regulating tissue homeostasis.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Bénédicte Oulès ◽  
Christina Philippeos ◽  
Joe Segal ◽  
Matthieu Tihy ◽  
Matteo Vietri Rudan ◽  
...  

Abstract Although acne is the most common human inflammatory skin disease, its pathogenic mechanisms remain incompletely understood. Here we show that GATA6, which is expressed in the upper pilosebaceous unit of normal human skin, is down-regulated in acne. GATA6 controls keratinocyte proliferation and differentiation to prevent hyperkeratinisation of the infundibulum, which is the primary pathological event in acne. When overexpressed in immortalised human sebocytes, GATA6 triggers a junctional zone and sebaceous differentiation program whilst limiting lipid production and cell proliferation. It modulates the immunological repertoire of sebocytes, notably by upregulating PD-L1 and IL10. GATA6 expression contributes to the therapeutic effect of retinoic acid, the main treatment for acne. In a human sebaceous organoid model GATA6-mediated down-regulation of the infundibular differentiation program is mediated by induction of TGFβ signalling. We conclude that GATA6 is involved in regulation of the upper pilosebaceous unit and may be an actionable target in the treatment of acne.


2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Maria del R. Ramos-Jerz ◽  
Socorro Villanueva ◽  
Gerold Jerz ◽  
Peter Winterhalter ◽  
Alexandra M. Deters

Methanolic avocado (Persea americanaMill., Lauraceae) seed extracts were separated by preparative HSCCC. Partition and HSCCC fractions were principally characterized by LC-ESI-MS/MS analysis. Theirin vitroinfluence was investigated on proliferation, differentiation, cell viability, and gene expression on HaCaT and normal human epidermal keratinocytes (NHEK) and normal human dermal fibroblasts (NHDF). The methanol-water partition (M) from avocado seeds and HSCCC fraction 3 (M.3) were mostly composed of chlorogenic acid and its isomers. Both reduced NHDF but enhanced HaCaT keratinocytes proliferation. HSCCC fractionM.2composed of quinic acid among chlorogenic acid and its isomers inhibited proliferation and directly induced differentiation of keratinocytes as observed on gene and protein level. Furthermore,M.2increased NHDF proliferation via upregulation of growth factor receptors. Salidrosides and ABA derivatives present in HSCCC fractionM.6increased NHDF and keratinocyte proliferation that resulted in differentiation. The residual solvent fractionM.7contained among low concentrations of ABA derivatives high amounts of proanthocyanidins B1 and B2 as well as an A-type trimer and stimulated proliferation of normal cells and inhibited the proliferation of immortalized HaCaT keratinocytes.


2012 ◽  
Vol 21 (11) ◽  
pp. 2441-2454 ◽  
Author(s):  
Vassilia-Ismini Alexaki ◽  
Despoina Simantiraki ◽  
Marianna Panayiotopoulou ◽  
Olga Rasouli ◽  
Maria Venihaki ◽  
...  

Epidermal organization and homeostasis are regulated by mesenchymal influences through paracrine actions. Until today, dermal fibroblasts (DFs) are used in the “dermal” layer to support keratinocyte growth in vitro in dermal and skin substitutes. In the present work, we used human adipose tissue-derived mesenchymal cells (ADMCs) as a support of keratinocyte growth in vitro (in monolayer culture and in 3D skin cell culture models) and in vivo (mouse wound healing models) and compared our findings with those obtained using dermal fibroblasts. ADMCs induce reepithelialization during wound healing more efficiently than DFs, by enhancing keratinocyte proliferation through cell cycle progression, and migration. This effect is mediated (at least partially) by a paracrine action of KGF-1 and PDGF-BB, which are more prominently expressed in ADMCs than in DFs. Furthermore, replacement of DFs by ADMCs in the dermal compartment of organotypic skin cultures leads to an artificial epidermis resembling to that of normal skin, concerning the general histology, although with a higher expression of cytokeratins 5 and 19. In Rag1 knockout mice, ADMCs induced a more rapid reepithelialization and a more effective wound healing, compared to dermal fibroblasts. In conclusion, we provide evidence that ADMCs can serve as supportive cells for primary keratinocyte cultures. In addition, because of their abundance and the great cell yield achieved during ADMC isolation, they represent an interesting cell source, with potential aspects for clinical use.


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