Membrane-associated collagens with interrupted triple-helices (MACITs):evolution from a bilaterian common ancestor and functional conservation <i>in C. elegans</i>

Protein sequence alignment of human collagens XIII, XXIII, XXV and six alternative spliced variants of COL-99. The protein sequence of the newly identified COL-99f was compared with the other COL-99 variants and human collagens XIII, XXIII and XXV. Putative furin cleavage residues in these proteins and the peptides for producing the COL-99 antibodies AB5625.11 and AB693 are highlighted in the sequence. (PDF 22 kb

Toward understanding scarless skin wound healing and pathological scarring

The efficient healing of skin wounds is crucial for securing the vital barrier function of the skin, but pathological wound healing and scar formation are major medical problems causing both physiological and psychological challenges for patients. A number of tightly coordinated regenerative responses, including haemostasis, the migration of various cell types into the wound, inflammation, angiogenesis, and the formation of the extracellular matrix, are involved in the healing process. In this article, we summarise the central mechanisms and processes in excessive scarring and acute wound healing, which can lead to the formation of keloids or hypertrophic scars, the two types of fibrotic scars caused by burns or other traumas resulting in significant functional or aesthetic disadvantages. In addition, we discuss recent developments related to the functions of activated fibroblasts, the extracellular matrix and mechanical forces in the wound environment as well as the mechanisms of scarless wound healing. Understanding the different mechanisms of wound healing is pivotal for developing new therapies to prevent the fibrotic scarring of large skin wounds.publishedVersio

Haavan paraneminen - diabetes sekä muut esteet ja hidasteet

Krooniset haavat ja haavan paranemisen pitkittyminen ovat merkittäviä kliinisiä ongelmia. Haavan paraneminen on monimutkainen biologinen prosessi, joka voidaan jakaa neljään vaiheeseen: verenvuodon tyrehtymiseen sekä sitä seuraaviin tulehdus-, korjaus- ja kypsymisvaiheisiin, joita säätelevät paikalliset olosuhteet. Haavan paranemiseen vaikuttaa myös yksilön yleistila kaikkine sairauksineen ja lääkityksineen. Paikallisista tekijöistä muun muassa tulehdusreaktiovaiheen pitkittyminen ja huono verenkierto edistävät haavojen kroonistumista. Diabetekseen liittyy huonontunut haavojen paranemistaipumus. Hyperglykemia heikentää haavan paranemista useilla eri mekanismeilla, joista yksi keskeinen perustuu hyperglykemian seurauksena kudoksiin ylimäärin kertyneiden, ei-entsymaattisesti liikaglykosyloituneiden molekyylien (advanced glycosylation end-products, AGE) käynnistämiin solubiologisiin häiriöihin. Paras keino estää hyperglykemian haitallinen vaikutus on tavoitella suositusten mukaista verenglukoosipitoisuutta

Complement Component C3 and Complement Factor B Promote Growth of Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma (cSCC) is one of the most common metastatic skin cancers with increasing incidence. We examined the roles of complement component C3 and complement factor B (CFB) in the growth of cSCC. Analysis of cSCC cell lines (n = 8) and normal human epidermal kerati-nocytes (n = 11) with real-time quantitative PCR and Western blotting revealed up-regulation of C3 and CFB expression in cSCC cells. Immunohistochemical staining revealed stronger tumor cell specific Labeling for C3 and CFB in invasive cSCCs (n = 71) and recessive dystrophic epidermolysis bullosa-associated cSCCs (n = 11) than in cSCC in situ (n = 69), actinic keratoses (n = 63), and normal skin (n = 5). Significant up-regulation of C3 and CFB mRNA expression was noted in chemically induced mouse cSCCs, compared to benign papillomas. Knockdown of C3 and CFB expression inhibited migration and proliferation of cSCC cells and resulted in potent inhibition of extracellular signal regulated kinase 1/2 activation. Knockdown of C3 and CFB markedly inhibited growth of human cSCC xenograft tumors in vivo. These results provide evidence for the rotes of C3 and CFB in the development of cSCC and identify them as biomarkers and potential therapeutic targets in this metastatic skin cancer.Peer reviewe

Elevated VEGF-D Modulates Tumor Inflammation and Reduces the Growth of Carcinogen-Induced Skin Tumors

Vascular endothelial growth factor D (VEGF-D) promotes the lymph node metastasis of cancer by inducing the growth of lymphatic vasculature, but its specific roles in tumorigenesis have not been elucidated. We monitored the effects of VEGF-D in cutaneous squamous cell carcinoma (cSCC) by subjecting transgenic mice overexpressing VEGF-D in the skin (K14-mVEGF-D) and VEGF-D knockout mice to a chemical skin carcinogenesis protocol involving 7,12-dimethylbenz[a] anthracene and 12-O-tetradecanoylphorbol-13-acetate treatments. In K14-mVEGF-Dmice, tumor lymphangiogenesis was significantly increased and the frequency of lymph node metastasis was elevated in comparison with controls. Most notably, the papillomas regressed more often in K14-mVEGF-D mice than in littermate controls, resulting in a delay in tumor incidence and a remarkable reduction in the total tumor number. Skin tumor growth and metastasis were not obviously affected in the absence of VEGF-D; however, the knockout mice showed a trend for reduced lymphangiogenesis in skin tumors and in the untreated skin. Interestingly, K14-mVEGF-D mice showed an altered immune response in skin tumors. This consisted of the reduced accumulation of macrophages, mast cells, and CD4(+) T-cells and an increase of cytotoxic CD8(+) T-cells. Cytokine profiling by flow cytometry and quantitative real time PCR revealed that elevated VEGF-D expression results in an attenuated Th2 response and promotes M1/Th1 and Th17 polarization in the early stage of skin carcinogenesis, leading to an anti-tumoral immune environment and the regression of primary tumors. Our data suggest that VEGF-D may be beneficial in early-stage tumors since it suppresses the pro-tumorigenic inflammation, while at later stages VEGF-D-induced tumor lymphatics provide a route for metastasis.Peer reviewe

Type XVIII collagen degradation products in acute lung injury

Introduction: In acute lung injury, repair of the damaged alveolar-capillary barrier is an essential part of recovery. Endostatin is a 20 to 28 kDa proteolytic fragment of the basement membrane collagen XVIII, which has been shown to inhibit angiogenesis via action on endothelial cells. We hypothesised that endostatin may have a role in inhibiting lung repair in patients with lung injury. The aims of the study were to determine if endostatin is elevated in the plasma/bronchoalveolar lavage fluid of patients with acute lung injury and ascertain whether the levels reflect the severity of injury and alveolar inflammation, and to assess if endostatin changes occur early after the injurious lung stimuli of one lung ventilation and lipopolysaccharide (LPS) challenge. Methods: Endostatin was measured by ELISA and western blotting. Results: Endostatin is elevated within the plasma and bronchoalveolar lavage fluid of patients with acute lung injury. Lavage endostatin reflected the degree of alveolar neutrophilia and the extent of the loss of protein selectivity of the alveolar-capillary barrier. Plasma levels of endostatin correlated with the severity of physiological derangement. Western blotting confirmed elevated type XVIII collagen precursor levels in the plasma and lavage and multiple endostatin-like fragments in the lavage of patients. One lung ventilation and LPS challenge rapidly induce increases in lung endostatin levels. Conclusions: Endostatin may adversely affect both alveolar barrier endothelial and epithelial cells, so its presence within both the circulation and the lung may have a pathophysiological role in acute lung injury that warrants further evaluation

Novel pathogenic mutations and skin biopsy analysis in Knobloch syndrome

Purpose: To facilitate future diagnosis of Knobloch syndrome (KS) and better understand its etiology, we sought to identify not yet described COL18A1 mutations in KS patients. In addition, we tested whether mutations in this gene lead to absence of the COL18A1 gene product and attempted to better characterize the functional effect of a previously reported missense mutation. Methods: Direct sequencing of COL18A1 exons was performed in KS patients from four unrelated pedigrees. We used immunofluorescent histochemistry in skin biopsies to evaluate the presence of type XVIII collagen in four KS patients carrying two already described mutations: c. 3277C>T, a nonsense mutation, and c. 3601G>A, a missense mutation. Furthermore, we determined the binding properties of the mutated endostatin domain p.A1381T (c.3601G>A) to extracellular matrix proteins using ELISA and surface plasmon resonance assays. Results: We identified four novel mutations in COL18A1, including a large deletion involving exon 41. Skin biopsies from KS patients revealed lack of type XVIII collagen in epithelial basement membranes and blood vessels. We also found a reduced affinity of p.A1381T endostatin to some extracellular matrix components. Conclusions: COL18A1 mutations involved in Knobloch syndrome have a distribution bias toward the coding exons of the C-terminal end. Large deletions must also be considered when point mutations are not identified in patients with characteristic KS phenotype. We report, for the first time, lack of type XVIII collagen in KS patients by immunofluorescent histochemistry in skin biopsy samples. As a final point, we suggest the employment of this technique as a preliminary and complementary test for diagnosis of KS in cases when mutation screening either does not detect mutations or reveals mutations of uncertain effect, such as the p.A1381T change.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) - CEPIDConselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq

EphB2 Promotes Progression of Cutaneous Squamous Cell Carcinoma

Keratinocyte-derived skin cancer, cutaneous squamous cell carcinoma (cSCC), is the most common metastatic skin cancer. We have examined the role of Eph/ephrin signaling in the progression of cSCC. Analysis of the expression of EPH and EFN families in cSCC cells and normal epidermal keratinocytes revealed overexpression of EPHB2 mRNA in cSCC cells and cSCC tumors in vivo. Tumor cell–specific overexpression of EphB2 was detected in human cSCCs and in chemically induced mouse cSCCs with immunohistochemistry, whereas the expression of EphB2 was low in premalignant lesions and normal skin. Knockdown of EphB2 expression in cSCC cells suppressed growth and vascularization of cSCC xenografts in vivo and inhibited proliferation, migration, and invasion of cSCC cells in culture. EphB2 knockdown downregulated expression of genes associated with biofunctions cell viability, migration of tumor cells, and invasion of tumor cells. Among the genes most downregulated by EphB2 knockdown were MMP1 and MMP13. Moreover, activation of EphB2 signaling by ephrin-B2-Fc enhanced production of invasion proteinases matrix metalloproteinase-13 (MMP13) and MMP1, and invasion of cSCC cells. These findings provide mechanistic evidence for the role of EphB2 in the early progression of cSCC to the invasive stage and identify EphB2 as a putative therapeutic target in this invasive skin cancer

Stromal integrin α11 regulates PDGFRβ signaling and promotes breast cancer progression

Cancer-associated fibroblasts (CAFs) are key actors in modulating the progression of many solid tumors, such as breast cancer (BC). Herein, we identify an integrin alpha 11/PDGFR beta-positive CAF subset displaying tumor-promoting features in BC. In the preclinical MMTV-PyMT mouse model, integrin alpha 11 deficiency led to a drastic reduction of tumor progression and metastasis. A clear association between integrin alpha 11 and PDGFR beta was found at both transcriptional and histological levels in BC specimens. High stromal integrin alpha 11/PDGFR beta expression was associated with high grades and poorer clinical outcome in human BC patients. Functional assays using 5 CAF subpopulations (1 murine, 4 human) revealed that integrin alpha 11 promotes CAF invasion and CAF-induced tumor cell invasion upon PDGF-BB stimulation. Mechanistically, the proinvasive activity of integrin alpha 11 relies on its ability to interact with PDGFR beta in a ligand-dependent manner and to promote its downstream JNK activation, leading to the production of tenascin C, a proinvasive matricellular protein. Pharmacological inhibition of PDGFR beta and JNK impaired tumor cell invasion induced by integrin alpha 11 CAFs. Collectively, our study uncovers an integrin alpha 11 subset of protumoral CAFs that exploits the PDGFR beta/JNK signaling axis to promote tumor invasiveness in BC