This study confirms the previous suggestion of an association between SPINK5 and AD.
The extracellular matrix (ECM) was long thought to be merely a structural tissue support and ⁄ or a filter. However, recent studies have suggested that ECM proteins regulate many intracellular and extracellular events, including cell growth, cell adhesion, cell division, cell movement, and apoptosis. They do so through activation of several families of cell surface receptor, including the integrins and syndecans. The focus of this review is on two laminin isoforms expressed in the skin. Laminins are an important molecular component of the basement membranes in a variety of tissue types. They have a cruciform shape, and are composed of three chains-a, b, and c. Keratinocytes of the skin secrete numerous laminin isoforms, including laminin-511 and laminin-332. The latter are known to affect the behaviour of keratinocytes through binding to membrane-penetrating receptors (outside-in signal transduction). Conversely, the expression, secretion and assembly of lamininrich matrices is regulated by cell surface receptors through inside-out signal transduction. We will review how integrins regulate laminin matrix assembly and the signals elicited by laminins that support either migration or stable adhesion of keratinocytes. We will also discuss recent data indicating that laminins plays key regulatory roles in the development of skin appendages and contribute to the pathogenesis of skin cancer.
Stimulation of human neutrophils with tumor necrosis factor-α (TNF), granulocyte-macrophage colony-stimulating factor (GM-CSF), or granulocyte CSF (G-CSF) resulted in decreased fluorescence intensity of FITC-phalloidin (actin depolymerization) and morphological changes. Cytokine-induced actin depolymerization was dependent on the concentration of cytokines used as stimuli. The maximal changes were detected at 10 min after stimulation with TNF or GM-CSF and at 20 min after stimulation with G-CSF. Cytokine-induced actin depolymerization was sustained for at least 30 min after stimulation. In contrast, N-formyl-methionyl-leucyl-phenylalanine (FMLP) rapidly (within 45 s) induced an increase in the fluorescence intensity of FITC-phalloidin (actin polymerization) and morphological changes. TNF- and GM-CSF-induced actin depolymerization and morphological changes, but not FMLP-induced responses, were partially inhibited by either PD-98059, an inhibitor of mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) kinase, or SB-203580, an inhibitor of p38 MAPK, and were almost completely abolished by these inhibitors in combination. G-CSF-induced responses were almost completely abolished by PD-98059 and were unaffected by SB-203580. These findings are consistent with the ability of these cytokines to activate the distinct MAPK subtype cascade in human neutrophils. Phosphorylated ERK and p38 MAPK were not colocalized with F-actin in neutrophils stimulated by cytokines or FMLP. Furthermore, FMLP-induced polarization and actin polymerization were prevented by cytokine pretreatment. These findings suggest that TNF, GM-CSF, and G-CSF induce actin depolymerization and morphological changes through activation of ERK and/or p38 MAPK and that cytokine-induced actin reorganization may be partly responsible for the inhibitory effect of these cytokines on neutrophil chemotaxis.
Hochu-ekki-to is a traditional herbal (Kampo) medicine that has been shown to be effective for patients with Kikyo (delicate, easily fatigable, or hypersensitive) constitution. Previous case reports have suggested that this herbal drug was effective for a certain subgroup of patients with atopic dermatitis (AD). We aimed to evaluate the efficacy and safety of Hochu-ekki-to in the long-term management of Kikyo patients with AD. In this multicenter, double blind, randomized, placebo-controlled study, 91 Kikyo patients with AD were enrolled. Kikyo condition was evaluated by a questionnaire scoring system. All patients continued their ordinary treatments (topical steroids, topical tacrolimus, emollients or oral antihistamines) before and after their protocol entry. Hochu-ekki-to or placebo was orally administered twice daily for 24 weeks. The skin severity scores, total equivalent amount (TEA) of topical agents used for AD treatment, prominent efficacy (cases with skin severity score = 0 at the end of the study) rate and aggravated rate (more than 50% increase of TEA of topical agents from the beginning of the study) were monitored and evaluated. Seventy-seven out of 91 enrolled patients completed the 24-week treatment course (Hochu-ekki-to: n = 37, placebo: n = 40). The TEA of topical agents (steroids and/or tacrolimus) was significantly (P < 0.05) lower in the Hochu-ekki-to group than in the placebo group, although the overall skin severity scores were not statistically different. The prominent efficacy rate was 19% (7 of 37) in the Hochu-ekki-to group and 5% (2 of 40) in the placebo group (P = 0.06). The aggravated rate was significantly (P < 0.05) lower in the Hochu-ekki-to group (3%; 1 of 37) than in the placebo group (18%; 7 of 39). Only mild adverse events such as nausea and diarrhea were noted in both groups without statistical difference. This placebo-controlled study demonstrates that Hochu-ekki-to is a useful adjunct to conventional treatments for AD patients with Kikyo constitution. Use of Hochu-ekki-to significantly reduces the dose of topical steroids and/or tacrolimus used for AD treatment without aggravating AD.
For many years, extracellular matrix (ECM) was considered to function as a tissue support and filler. However, we now know that ECM proteins control many cellular events through their interaction with cell-surface receptors and cytoplasmic signaling pathways. For example, they regulate cell proliferation, cell division, cell adhesion, cell migration, and apoptosis. We focus in this review on a laminin isoform, laminin-332 (formerly termed laminin-5), a major component of the basement membrane (BM) of skin and other epithelial tissues. It is composed of 3 subunits (α3, β3, and γ2) and interacts with at least two integrin receptors expressed by epithelial cells (α3β1 and α6β4 integrin). Mutations in either laminin-332 or integrin α6β4 result in junctional epidermolysis bullosa, a blistering skin disease, while targeting of laminin-332 by autoantibodies in cicatricial pemphigoid leads to dysadhesion of epithelial cells from their underlying connective tissue. Abnormal expression of laminin-332 and its integrin receptors is also a hallmark of certain tumor types and is believed to promote invasion of colon, breast and skin cancer cells. Moreover, there is emerging evidence that laminin-332 and its protease degradation products are not only found at the leading front of several tumors but also likely induce and/or promote tumor cell migration. Thus, in this review, we focus specifically on the role of laminin-332 and its integrin receptors in adhesion, proliferation, and migration/invasion of cancer cells. Finally, we discuss strategies for the development of laminin-332-based antagonists for the treatment of malignant tumors.
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