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Skin Sections (skin + section)
Selected AbstractsTransforming growth factor-beta 1, 2, 3 and receptor type I and II in diabetic foot ulcersDIABETIC MEDICINE, Issue 6 2002E. B. Jude Abstract Aims To study the distribution of transforming growth factor-beta (TGF-,) 1, 2 and 3, and TGF-, receptor types I and II in diabetic foot ulcers, diabetic skin and normal skin by immunohistochemistry, immunofluorescence and Western blotting. We also compared the TGF-,s with those of chronic venous ulcers. Methods Skin biopsies were obtained from the leg or the foot of non-diabetic and diabetic subjects, and from the edge of diabetic foot ulcers and chronic venous ulcers. Distribution (by immunofluorescence and immunocytochemistry) of TGF-, 1, 2 and 3 and TGF-, receptors (RI and RII) was done by staining 8-µm skin sections using appropriate antibodies. Protein levels of TGF-, were measured by Western blot analysis. Results TGF-,3 expression was increased in the epithelium at the edge of diabetic foot ulcers, being more intense than diabetic and normal skin (P = 0.03, 0.02, respectively), as was its expression in venous ulcers compared with normal skin. However, TGF-,1 expression was not increased in diabetic foot ulcers and chronic venous ulcers, and was comparable to diabetic and normal skin. There was also no increase for the receptors in diabetic foot ulcers. Conclusion The lack of TGF-,1 up-regulation in both diabetic foot ulcers and venous ulcers may explain the impaired healing in these chronic wounds, and could represent a general pattern for chronicity. [source] Absence of lymphatic vessels in human dental pulp: a morphological studyEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 2 2010Renato Gerli Gerli R, Secciani I, Sozio F, Rossi A, Weber E, Lorenzini G. Absence of lymphatic vessels in human dental pulp: a morphological study. Eur J Oral Sci 2010; 118: 110,117. © 2010 The Authors. Journal compilation © 2010 Eur J Oral Sci Few and controversial data are available in the literature regarding the presence of lymphatic vessels in the human dental pulp. The present study was designed to examine morphologically the existence of a lymph drainage system in human dental pulp. Human dental pulp and skin sections were immunohistochemically stained with specific antibodies for lymphatic endothelium (D2-40, LYVE-1, VEGFR-3 [vascular endothelial growth factor receptor-3], and Prox-1), with the pan-endothelial markers CD31 and von Willebrand factor (vWF), and with the blood-specific marker CD34. Several blood vessels were identified in human pulps and skin. Lymphatic vessels were found in all human skin samples but in none of the pulps examined. Western blotting performed on human dermis and on pulps treated with collagenase (to remove odontoblasts) confirmed these results. Transmission electron microscopy indicated that vessels which, by light microscopy, appeared to be initial lymphatic vessels had no anchoring filaments or discontinuous basement membrane, both of which are typical ultrastructural characteristics of lymphatic vessels. These results suggest that under normal conditions human dental pulp does not contain true lymphatic vessels. The various theories about dental pulp interstitial fluid circulation should be revised accordingly. [source] Insulin receptor substrate 1 (IRS-1) plays a unique role in normal epidermal physiology,JOURNAL OF CELLULAR PHYSIOLOGY, Issue 2 2007Marianna Sadagurski Insulin receptor substrate (IRS) proteins play a central role in insulin signaling. Previously we have demonstrated that insulin is essential for normal skin development and function. In the present study we investigated the involvement of the IRS-1 and IRS-2 proteins in skin physiology and in mediating insulin action in skin. For this purpose we have investigated the effects of inactivation of each of the IRSs on skin, studying skin sections and primary skin cells derived from IRS-1 or IRS-2 null mice. We have demonstrated that while the skin of the IRS-2 null mice appeared normal, the skin of the IRS-1 null mice was thinner and translucent. Histological analysis revealed that the thinning of the IRS-1 null skin was a consequence of the thinning of the spinous compartment, consisting of fewer layers. Proliferation of the IRS-1 and IRS-2 null skin epidermal cells was normal. However, the differentiation process of the IRS-1 skin and skin cells was impaired. There was a marked decrease in the induction of the expression of K1, the marker of advanced stages of skin differentiation. In contrary, IRS-2 inactivation had no effects on skin differentiation. In conclusion, we have shown for the first time that IRS-1 but not IRS-2 has an effect on skin formation and development, being one of the main activators of the differentiation process in skin keratinocytes. Furthermore, we suggest that IRS-1 and IRS-2 have distinct roles in skin physiology. J. Cell. Physiol. 213: 519,527, 2007. © 2007 Wiley-Liss, Inc. [source] Decapeptide with fibroblast growth factor (FGF)-5 partial sequence inhibits hair growth suppressing activity of FGF-5JOURNAL OF CELLULAR PHYSIOLOGY, Issue 2 2003Chikako Ito Earlier studies demonstrated that knock-out of fibroblast growth factor-5 gene (Fgf-5) prolonged anagen VI phase of hair cycle, resulting long hairs in the mice. We showed the activities on hair growth of the two Fgf-5 gene products, one of which, FGF-5 suppressed hair growth by inhibiting anagen proceeding and inducing the transition from anagen to catagen, and FGF-5S, a shorter polypeptide with FGF-5-antagonizing activity translated from alternatively spliced mRNA, suppressed this activity of FGF-5. As the results suggested that FGF-5 antagonist would increase hair growth, we synthesized various peptides having partial sequences of human FGF-5 and FGF-5S and determined their FGF-5 antagonist activity. Among them, a decapeptide designated P3 (95-VGIGFHLQIY-104) that aligns with receptor binding sites of FGF-1 and FGF-2 suppressed FGF-5-induced proliferation of BALB/3T3 A31 and NIH/3T3 murine fibroblasts, and FGF receptor-1c (FGFR-1c)-transfected Ba/F3 cell line (FR-Ba/F3 cells). IC50s of this peptide on these cell proliferations were 64, 28, 146 ,M, respectively. On the other hand, IC50 of this peptide on binding of FGF-5 to the FGFR-1(IIIc)/Fc chimera was 483 ,M. Examination in dorsal depilated mice revealed that the P3 peptide reduced the activity of FGF-5 to recover hair pigmentation and hair follicle lengths. The classification of histologically observed skin sections showed FGF-5-induced delations of anagen procedure had reduced by the P3 peptide. The anti-Ki67 antibody staining of hair follicles was inhibited by administration of FGF-5, and this inhibition by FGF-5 was recovered by administration of the P3 peptide. The P3 peptide alone did not affect hair follicle length and hair cell proliferation. These results indicate that the decapeptide antagonized FGF-5 activity in vivo, and reduced the inhibition of FGF-5 in hair growth, confirming that FGF-5 inhibitors are promising substances against hair loss and/or for promoting hair growth. J. Cell. Physiol. 197: 272,283, 2003. © 2003 Wiley-Liss, Inc. [source] MicroRNA-29, a key regulator of collagen expression in systemic sclerosisARTHRITIS & RHEUMATISM, Issue 6 2010Britta Maurer Objective To investigate the role of microRNA (miRNA) as posttranscriptional regulators of profibrotic genes in systemic sclerosis (SSc). Methods MicroRNA, which target collagens, were identified by in silico analysis. Expression of miRNA-29 (miR-29) was determined by TaqMan real-time polymerase chain reaction analysis of skin biopsy and fibroblast samples from SSc patients and healthy controls as well as in the mouse model of bleomycin-induced skin fibrosis. Cells were transfected with precursor miRNA (pre-miRNA)/anti-miRNA of miR-29 using Lipofectamine. Collagen gene expression was also studied in luciferase reporter gene assays. For stimulation, recombinant transforming growth factor , (TGF,), platelet-derived growth factor B (PDGF-B), or interleukin-4 (IL-4) was used. The effects of inhibiting PDGF-B and TGF, signaling on the levels of miR-29 were studied in vitro and in the bleomycin model. Results We found that miR-29a was strongly down-regulated in SSc fibroblasts and skin sections as compared with the healthy controls. Overexpression in SSc fibroblasts significantly decreased, and accordingly, knockdown in normal fibroblasts increased, the levels of messenger RNA and protein for type I and type III collagen. In the reporter gene assay, cotransfection with pre-miR-29a significantly decreased the relative luciferase activity, which suggests a direct regulation of collagen by miR-29a. TGF,, PDGF-B, or IL-4 reduced the levels of miR-29a in normal fibroblasts to those seen in SSc fibroblasts. Similar to human SSc, the expression of miR-29a was reduced in the bleomycin model of skin fibrosis. Inhibition of PDGF-B and TGF, pathways by treatment with imatinib restored the levels of miR-29a in vitro and in the bleomycin model in vivo. Conclusion These data add the posttranscriptional regulation of collagens by miR-29a as a novel aspect to the fibrogenesis of SSc and suggest miR-29a as a potential therapeutic target. [source] The transcription factor Fra-2 regulates the production of extracellular matrix in systemic sclerosisARTHRITIS & RHEUMATISM, Issue 1 2010Nicole Reich Objective Fra-2 belongs to the activator protein 1 family of transcription factors. Mice transgenic for Fra-2 develop a systemic fibrotic disease with vascular manifestations similar to those of systemic sclerosis (SSc). The aim of the present study was to investigate whether Fra-2 plays a role in the pathogenesis of SSc and to identify the molecular mechanisms by which Fra-2 induces fibrosis. Methods Dermal thickness and the number of myofibroblasts were determined in skin sections from Fra-2,transgenic and wild-type mice. The expression of Fra-2 in SSc patients and in animal models of SSc was analyzed by real-time polymerase chain reaction and immunohistochemistry. Fra-2, transforming growth factor , (TGF,), and ERK signaling in SSc fibroblasts were inhibited using small interfering RNA, neutralizing antibodies, and small-molecule inhibitors. Results Fra-2,transgenic mice developed a skin fibrosis with increases in dermal thickness and increased myofibroblast differentiation starting at age 12 weeks. The expression of Fra-2 was up-regulated in SSc patients and in different mouse models of SSc. Stimulation with TGF, and platelet-derived growth factor (PDGF) significantly increased the expression of Fra-2 in SSc fibroblasts and induced DNA binding of Fra-2 in an ERK-dependent manner. Knockdown of Fra-2 potently reduced the stimulatory effects of TGF, and PDGF and decreased the release of collagen from SSc fibroblasts. Conclusion We demonstrate that Fra-2 is overexpressed in SSc and acts as a novel downstream mediator of the profibrotic effects of TGF, and PDGF. Since transgenic overexpression of Fra-2 causes not only fibrosis but also vascular disease, Fra-2 might be an interesting novel candidate for molecular-targeted therapies for SSc. [source] Effect of solute lipophilicity on penetration through canine skinAUSTRALIAN VETERINARY JOURNAL, Issue 12 2003PC MILLS Objective To investigate the effect of lipophilicity on the percutaneous penetration of a homologous series of alcohols through canine skin Design Skin harvested from Greyhound thorax was placed in Franz-type diffusion cells and the in vitro passage of radio-labelled (14C) alcohols (ethanol, butanol, hexanol and octanol (Log P 0.19 - 3.0)) through separate skin sections was measured in replicates of five. Permeability coefficient (kP, cm/h), maximum flux (Jmax, mol/cm2/h) and residue remaining within the skin were determined. Results The kP increased with increasing lipophilicity (6.2 times 10 -4± 1.6 times 10 -4 cm/h for ethanol to 1.8 times 10 -2± 3.6 times 10 -3 cm/h for octanol). Alcohol residues remaining within each skin sample followed a similar pattern. An exponential decrease in Jmax with increasing lipophilicity was observed. Conclusion Changes in canine skin permeability occur with increasing alcohol lipophilicity. This finding has practical consequences for the design of topical formulations and optimisation of drug delivery through animal skin. [source] Proapoptotic and antiapoptotic markers in cutaneous T-cell lymphoma skin infiltrates and lymphomatoid papulosisBRITISH JOURNAL OF DERMATOLOGY, Issue 6 2001H. Nevala Background In cutaneous T-cell lymphoma (CTCL) lesions, both reactive T cells and malignant T cells intermingle. The disease progression is mostly slow. Recent evidence suggests that even if clinical remission is reached, malignant cells persist and a relapse follows sooner or later. To what extent tumour cell apoptosis occurs in the skin lesions either due to the reactive T cells or to therapeutic efforts is not known. Objectives To determine the extent of tumour cell apoptosis and the expression of proapoptotic and antiapoptotic markers in serial skin lesion samples from patients with CTCL, and to compare the findings with those in patients with lymphomatoid papulosis (LyP). Methods Thirty-four skin samples were obtained from 12 patients with CTCL at the time of diagnosis and at a mean of 1·6, 3 and 6 years later. The patients received psoralen plus ultraviolet A (PUVA), electron beam or cytostatic treatments. In addition, fresh post-treatment samples from three patients with CTCL undergoing PUVA therapy were obtained. For comparison, skin biopsies of five patients with LyP were studied. Immunohistochemical demonstration of the expression of the following markers was performed on formalin-fixed skin sections: Fas (CD95), Fas ligand (FasL), bcl-2, granzyme B, the tumour-suppressor protein PTEN and the effector caspase, caspase-3. The malignant cells were identified morphologically, and apoptotic cells were identified with the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling method on parallel sections. Results In untreated CTCL lesions, apoptotic lymphocytes were extremely rare, and no increase in the number of apoptotic cells was observed after any of the treatments used. In LyP, apoptotic cells were more frequent, comprising on average 5% of the infiltrate. The apoptosis-associated markers Fas, FasL, caspase-3 and granzyme B were expressed by morphologically neoplastic cells in CTCL and by large atypical cells in LyP, with no significant differences. However, only a few reactive cells in CTCL infiltrates expressed granzyme B while about 10% of the corresponding cells were positive in LyP. The expression of antiapoptotic bcl-2 was more frequent in CTCL than in LyP, while PTEN expression was high in both instances. The number of bcl-2+ cells tended to decrease after therapy. When comparing the findings between the first and the last samples, a decrease in the number of bcl-2+ cells and an increase in Fas+ cells was associated with disease progression, despite therapy, while the opposite was true for remissions. Conclusions Apoptosis was found to be a rare event in CTCL lesions irrespective of preceding therapy. During patient follow-up, no significant differences in the expression of apoptotic markers was observed while in most cases a lower level of antiapoptotic bcl-2 expression was observed after all types of therapies and in association with disease progression when compared with high expression in the untreated lesions. The absence of apoptosis and high expression of bcl-2 together with a low expression of apoptosis-inducing granzyme B in the reactive lymphocytes in CTCL could explain the chronic nature of the disease and the poor response to therapy, while the more frequent occurrence of granzyme B and apoptosis together with a lower level of expression of bcl-2 by the large atypical cells in LyP could contribute to the favourable outcome of the latter. [source] | ||||||||||