Interleukin-10 inhibits IgE-mediated nitric oxide synthase induction and cytokine synthesis in normal human keratinocytes

Human keratinocytes (HK) generate nitric oxide (NO) and proinflammatory mediators following activation with either IgE/anti-IgE immune complexes or a combination of lipopolysaccharide (LPS) and interferon-γ (IFN-γ). Recently, interleukin-10 (IL-10) has been shown to down-regulate various inflammatory responses and to be secreted by lymphocytes and dendritic cells during skin inflammatory reactions. We show here that IL-10 down-regulates the production of tumor necrosis factor (TNF)-α and IL-6 by activated HK. Also, induction of inducible nitric oxide synthase (iNOS) expression in HK by IgE/anti-IgE or LPS/IFN-γ is significantly reduced by the addition of IL-10. This effect is dose dependent and correlates with reduction of iNOS mRNA production and enzyme level. Therefore, IL-10 down-regulates NO-mediated HK inflammatory responses and may thus participate in the regulation of the skin immune network.     

Loss-of-function mutations in caspase recruitment domain-containing protein 14 (CARD14) are associated with a severe variant of atopic dermatitis

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皮肤角质形成细胞的无血清培养方法

目的探索建立少量成年自体皮肤角质形成细胞体外无血清培养体系,为自体组织工程皮肤的构建与移植奠定物质基础。方法:无菌条件下,取2cm×2cm 兔耳皮肤组织块,Dispase 消化,分离真表皮,表皮以胰蛋白酶+EDTA 消化获得角质形成细胞,以含钙和不含钙的角质形成细胞培养液(K-SFM),按不同细胞密度接种于24孔板,观察细胞生长状况;免疫组化鉴定,MTT 法测定不同血清浓度对角质形成细胞增殖分化的影响。结果:在适当的 Ca~(2+)浓度下,少量自体角质形成细胞能够在无血清培养液 k-SFM 中培养扩增,最多可传4～6代。添加血清后可明显加速细胞分化。结论:无血清培养体系适用于少量成年自体角质形成细胞的体外连续培养扩增,培养的细胞可用于自体组织工程皮肤的构建。     

Tissue engineered artificial skin composed of dermis and epidermis

Abstract: We made an artificial skin comprised of a stratified layer of keratinocytes and a dermal matrix with a type I collagen containing fibroblasts. In this work, we showed keratinocyte behavior under primary culture, gel contractions varying with concentration of collagen solution, and cell growth plots in the collagen gel. The optimum behavior of dermal equivalent could be obtained using 3.0 mg/ml collagen solution and attached gel culture. The attached gel culture had a jumping effect of growth factor on cell growth at the lag phase. To develop the artificial skin, 1× 10⁵ cells/cm² of keratinocytes were cultured on the dermal equivalent at air-liquid interface. Finally, to overcome the problem that artificial skin of collagen gel was torn easily during suturing of grafting, we prepared histocompatible collagen mesh and attached the mesh to the bottom of the gel. Cultured artificial skins were successfully grafted onto rats.     

Wound healing potential of a dimeric InlB variant analyzed by in vitro experiments on re-epithelialization of human skin models

A constitutively dimeric truncated variant of internalin B (InlB₃₂₁-CD), acting as stimulator of the receptor tyrosine kinase MET, was tested for dermal wound-healing potential. Due to a lack of the endogenous MET agonist HGF/SF in chronic wounds, HGF/SF substitution by an InlB₃₂₁-CD-loaded hydrogel might be beneficial in chronic wound therapy.In this study, InlB₃₂₁-CD in solution and incorporated in a hydrogel was tested for mitogenic effects on immortalized human dermal keratinocytes (HaCaT) with an MTT assay. Cell migration was investigated with a scratch assay on primary keratinocytes (PHK) and on HaCaT. For the latter, scratching needed to be mitomycin C-controlled. InlB₃₂₁-CD effects on a model of human skin were analyzed histologically with respect to viability.InlB₃₂₁-CD led to dose-dependent proliferative effects on HaCaT cells whereas the equimolar dose of monomeric InlB₃₂₁ did not. Upon hydrogel incorporation of InlB₃₂₁-CD its mitogenic activity for HaCaT cells was maintained thus confirming the hydrogel as a promising drug delivery system. Motogenic effects were shown on both HaCaT and PHK cells. InlB₃₂₁-CD neither possesses cytotoxic effects on the viability of a human skin model nor alters its organotypic cell morphology.     

Cells of origin and tumor-initiating cells for nonmelanoma skin cancers

The epidermis of the skin is a multilayered stratified epithelium whose primary function is to provide a barrier against our external environment. As a result, cells in the epidermis are subject to constant assault from environmental pathogens, many of which can cause deleterious mutations. However, most of these mutations do not lead to skin cancer. One explanation is that most genetic hits are sustained by mature or transit cells with limited proliferative capacity and only stem cells that acquire genetic alterations have the potential to propagate a frank tumor. In this mini-review we will discuss recent studies that provide some of the first genetic evidence to support a stem cell origin for a number of skin cancer types.     

Programmed cell death 1 (PD-1) regulates the effector function of CD8 T cells via PD-L1 expressed on target keratinocytes

Programmed cell death 1 (PD-1) is an inhibitory molecule expressed by activated T cells. Its ligands (PD-L1 and -L2; PD-Ls) are expressed not only by a variety of leukocytes but also by stromal cells. To assess the role of PD-1 in CD8 T cell-mediated diseases, we used PD-1-knockout (KO) OVA-specific T cell-receptor transgenic (Tg) CD8 T cells (OT-I cells) in a murine model of mucocutaneous graft-versus-host disease (GVHD). We found that mice expressing OVA on epidermal keratinocytes (K14-mOVA mice) developed markedly enhanced GVHD-like disease after transfer of PD-1-KO OT-I cells as compared to those mice transferred with wild-type OT-I cells. In addition, K14-mOVA × OT-I double Tg (DTg) mice do not develop GVHD-like disease after adoptive transfer of OT-I cells, while transfer of PD-1-KO OT-I cells caused GVHD-like disease in a Fas/Fas-L independent manner. These results suggest that PD-1/PD-Ls-interactions have stronger inhibitory effects on pathogenic CD8 T cells than does Fas/Fas-L-interactions. Keratinocytes from K14-mOVA mice with GVHD-like skin lesions express PD-L1, while those from mice without the disease do not. These findings reflect the fact that primary keratinocytes express PD-L1 when stimulated by interferon-γ in vitro. When co-cultured with K14-mOVA keratinocytes for 2 days, PD-1-KO OT-I cells exhibited enhanced proliferation and activation compared to wild-type OT-I cells. In addition, knockdown of 50% PD-L1 expression on the keratinocytes with transfection of PD-L1-siRNA enhanced OT-I cell proliferation. In aggregate, our data strongly suggest that PD-L1, expressed on activated target keratinocytes presenting autoantigens, regulates autoaggressive CD8 T cells, and inhibits the development of mucocutaneous autoimmune diseases.     

骨髓来源间充质干细胞培养上清液减轻脂多糖诱导的小鼠急性肺损伤

 目的:观察经尾静脉输注骨髓间充质干细胞培养上清液（MSCs CdM）对脂多糖(LPS)诱导的小鼠急性肺损伤的治疗作用及其机制。方法:采用全骨髓培养法分离纯化骨髓间充质干细胞,传至第3代时观察细胞形态,流式细胞术检测细胞表面标志,并且收集上清液用超滤离心管进行离心。30只BALB/c小鼠随机分为对照组、 LPS模型组和MSCs CdM治疗组。对照组腹腔内注射生理盐水（0.01 mL/g）,LPS组和MSCs CdM治疗组腹腔内注射LPS（5 mg/kg,0.01 mL/g）制备急性肺损伤模型。造模1 h后经尾静脉输注MSCs CdM（MSCs  CdM治疗组）或生理盐水 （LPS组或对照组）300 μL。6 h后处死小鼠,留取标本检测肺组织病理形态学、肺组织湿干重比（W/D）、支气管肺泡灌洗液（BALF）中蛋白含量、血清及BALF中细胞因子水平和肺组织中髓过氧化物酶(MPO)的活性。结果:与对照组比较,LPS处理后肺组织病理损伤严重,BALF中蛋白、血清肿瘤坏死因子α(TNF-α)和白细胞介素6(IL-6)含量、肺组织中MPO活性及肺组织湿干重比均显著升高。与LPS组比较,MSCs CdM治疗组肺组织病理损伤程度减轻,BALF中蛋白、血清TNF-α和IL-6含量、肺组织中MPO活性及肺组织湿干重比均显著降低,而BALF中白细胞介素10（IL-10）和角质细胞生长因子（KGF）水平显著高于LPS组和对照组。结论:骨髓间充质干细胞培养上清液可有效减轻LPS诱导的急性肺损伤,其作用机制可能与其调节肺部TNF-α、IL-6、IL-10和KGF的水平有关。     

CCN2 is transiently expressed by keratinocytes during re-epithelialization and regulates keratinocyte migration in vitro by the ras-MEK-ERK signaling pathway

Background

CCN2 (previously known as connective tissue growth factor) is a multifunctional matricellular protein that has numerous effects on cell life and cell interactions with the connective tissue. Although the importance of CCN2 for the fibrotic process in wound healing has been well studied, the involvement of CCN2 in keratinocyte function has not yet been explored. Therefore, the aim of the present study was to investigate the role of CCN2 in the epidermis during wound healing.

Materials and methods

Immunohistochemistry was done on sections from full-thickness porcine wounds. The effect of CCN2 on the migration of cultured human keratinocytes exposed to scratch wounds, the effect on phosphorylation of extracellular signal-related kinases (ERK), and the effect of adding inhibitors to the ERK/mitogen-activated protein kinase pathway to human keratinocytes were studied.

Results

The CCN2 protein was transiently expressed in vivo at the leading keratinocyte edge during re-epithelialization of full-thickness porcine wounds. In vitro, exogenous addition of CCN2 to human keratinocyte cultures regulated keratinocyte migration and resulted in phosphorylation of ERK. The addition of inhibitors of ERK/mitogen-activated protein kinase counteracted the effect of CCN2 on migration.

Conclusions

CCN2 was transiently expressed at the leading keratinocyte edge in vivo. The biologic importance of this was supported in vitro, because CCN2 regulated human keratinocyte migration through activation of the Ras-mitogen-activated protein kinase kinase-ERK signal transduction pathway.