Matrix metalloproteinases in the restorative proctocolectomy pouch of pediatric ulcerative colitis.

AIM: To investigate matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) in pouch mucosa of pediatric onset ulcerative colitis (UC). METHODS: In this cross-sectional study, 28 patients with pediatric onset UC underwent ileal pouch biopsy 13 years (median) after proctocolectomy. Expression of MMPs-3, -7, -8, -9, -12 and -26 and TIMPs-1, -2 and -3 in samples was examined using immunohistochemichal methods, and another biopsy was used to evaluate the grade of histological inflammation. Two investigators independently graded the immunohistochemical specimens in a semiquantitative fashion, using a scale marking staining intensity as follows: 0 = less than 20 positive cells; 1 = 20-50 positive cells; 2 = 50-200 positive cells; 3 = over 20 positive cells. Fecal calprotectin and blood inflammatory markers [serum C-reactive protein (CRP) and erythrocyte sedimentation rate] were determined during a follow-up visit to examine correlations between these markers and the expression of MMPs and TIMPs. RESULTS: Of the 28 patients with pediatric onset UC, nine had not experienced pouchitis, whereas thirteen reported a single episode, and six had recurrent pouchitis (≥ 4 episodes). At the time of the study, six patients required metronidazole. In all of the others, the most recent episode of pouchitis had occurred over one month earlier, and none were on antibiotics. Only four samples depicted no sign of inflammation, and these were all from patients who had not had pouchitis. Two samples were too small to determine the grade of inflammation, but both had suffered pouchitis, the other recurrent. No sample depicted signs of colonic metaplasia. Most pouch samples showed expression of epithelial (e) and stromal (s) MMP-3 (e, n = 22; s, n = 20), MMP-7 (e, n = 28; s, n = 27), MMP-12 (e, n = 20; s, n =24), TIMP-2 (e, n = 23; s, n = 23) and MMP-3 (e, n = 23; s, n = 28) but MMP-8 (e, n = 0; s, n = 1), MMP-9 (e, n = 0; s, n = 9) and MMP-26 (e, n = 0; s, n = 3) and TIMP-1 (n = 0, both) were lacking. In samples with low grade of inflammatory activity, the epithelial MMP-3 and MMP-7 expression was increased (r = -0.614 and r = -0.472, respectively, P < 0.05 in both). MMPs and TIMPs did not correlate with the markers of inflammation, fecal calprotectin, erythrocyte sedimentation rate, or CRP, with the exception of patients with low fecal calprotectin (< 100 µg/g) in whom a higher expression of epithelial MMP-7 was found no differences in MMP- or TIMP-profiles were seen in patients with a history of pouchitis compared to ones with no such episodes. Anastomosis with either straight ileoanal anastomosis or ileoanal anastomosis with J-pouch did depict differences in MMP- or TIMP-expression. CONCLUSION: The expression of MMPs pediatric UC pouch in the long-term shares characteristics with inflammatory bowel disease, but inflammation cannot be classified as a reactivation of the disease.

IL-33 and ST2 in atopic dermatitis: expression profiles and modulation by triggering factors.

In the acute phase of atopic dermatitis (AD), T-helper type 2 (Th2) cytokines characterize the inflammatory response in the skin. IL-33 is a new tissue-derived cytokine, which is mainly expressed by cells of barrier tissues, and is known to activate Th2 lymphocytes, mast cells, and eosinophils. IL-33 signals through a receptor complex consisting of IL-33-specific receptor ST2 and a co-receptor IL-1RAcP. As IL-33 is known to promote Th2-type immunity, we examined expression profiles of IL-33 and its receptor components in human AD skin, in the murine model of AD, and in various cell models. We found increased expression of IL-33 and ST2 in AD skin after allergen or staphylococcal enterotoxin B (SEB) exposure, as well as in the skin of 22-week-old filaggrin-deficient mice. In addition, skin fibroblasts, HaCaT keratinocytes, primary macrophages, and HUVEC endothelial cells efficiently produced IL-33 in response to the combined stimulation of tumor necrosis factor-α and IFN-γ, which was further enhanced by a mimetic of double-stranded RNA. Finally, the increased expression of IL-33 and ST2 caused by irritant, allergen, or SEB challenge was suppressed by topical tacrolimus treatment. These results suggest an important role for IL-33-ST2 interaction in AD and highlight the fact that bacterial and viral infections may increase the production of IL-33.

Matrix metalloproteinase-ß19 expressed in cerebral amyloid angiopathy.

BACKGROUND: Cerebral amyloid angiopathy (CAA) is a frequent finding in the brains of patients with Alzheimer's disease (AD). CAA may be complicated with CAA-associated intracerebral haemorrhage (CAAH). Previous studies have revealed matrix metalloproteinase (MMP) expression in a mouse model of CAA and in human intracerebral haemorrhage. Here we studied the involvement of MMPs in human CAA and CAAH. MATERIAL AND METHODS: To investigate the putative expression of MMPs in human CAA and CAAH (Step 1), immunohistochemistry (IHC) against MMPs-1, -2, -7, -9, -19 and -26 was applied on tissue microarray (TMA) constructed of cerebral samples from 29 individuals with AD, 15 with CAAH and 2 controls. The findings in TMA were confirmed (Step 2) in tissue samples from 64 individuals, 45 presenting with CAA (including 36 with CAAH) and 19 without CAA (including 11 with hypertensive cerebral haemorrhage). RESULTS: In Step 1, immunoreactivity against MMPs-19 and -26 was detected in cerebral blood vessels in CAA. The results were confirmed in Step 2, where CAA (p<0.001) and intracerebral haemorrhage (p=0.045) were associated with vascular immunoreactivity against MMP-19. Multivariate analysis showed that the association between vascular MMP-19 and intracerebral haemorrhage was dependent from CAA. MMP-26 associated with CAA (p=0.021) but not with intracerebral haemorrhage. CONCLUSION: This is the first human study showing local MMP-19 immunoreactivity in the Aß-amyloid-laden blood vessels in CAA, suggesting that MMPs may be involved in CAA.

Polymorphisms of the ITGAM gene confer higher risk of discoid cutaneous than of systemic lupus erythematosus.

BACKGROUND: Lupus erythematosus (LE) is a heterogeneous disease ranging from mainly skin-restricted manifestations (discoid LE [DLE] and subacute cutaneous LE) to a progressive multisystem disease (systemic LE [SLE]). Genetic association studies have recently identified several strong susceptibility genes for SLE, including integrin alpha M (ITGAM), also known as CD11b, whereas the genetic background of DLE is less clear. PRINCIPAL FINDINGS: To specifically investigate whether ITGAM is a susceptibility gene not only for SLE, but also for cutaneous DLE, we genotyped 177 patients with DLE, 85 patients with sporadic SLE, 190 index cases from SLE families and 395 population control individuals from Finland for nine genetic markers at the ITGAM locus. SLE patients were further subdivided by the presence or absence of discoid rash and renal involvement. In addition, 235 Finnish and Swedish patients positive for Ro/SSA-autoantibodies were included in a subphenotype analysis. Analysis of the ITGAM coding variant rs1143679 showed highly significant association to DLE in patients without signs of systemic disease (P-value  = 4.73×10(-11), OR  = 3.20, 95% CI  = 2.23-4.57). Significant association was also detected to SLE patients (P-value  = 8.29×10(-6), OR  = 2.14, 95% CI  = 1.52-3.00), and even stronger association was found when stratifying SLE patients by presence of discoid rash (P-value  = 3.59×10(-8), OR  = 3.76, 95% CI  = 2.29-6.18). SIGNIFICANCE: We propose ITGAM as a novel susceptibility gene for cutaneous DLE. The risk effect is independent of systemic involvement and has an even stronger genetic influence on the risk of DLE than of SLE.

Ultraviolet B radiation regulates cysteine-rich protein 1 in human keratinocytes.

BACKGROUND: Cysteine-rich protein 1 (CRP1) is a growth-inhibitory cytoskeletal protein that is induced by ultraviolet (UV) C radiation radiation in fibroblasts. Our aim was to investigate the effects of UV radiation on CRP1 in keratinocytes, the main cell type subjected to UV radiation in the human body. METHODS: The effects of physiologically relevant doses of UVB radiation on CRP1 protein levels were studied in cultured primary keratinocytes and transformed cell lines (HaCaT, A-431) by immunoblotting. UVB-induced keratinocyte apoptosis was assessed by flow cytometry and monitoring caspase activity. Expression of CRP1 in human skin in vivo was studied by immunohistochemistry in samples of normal skin, actinic keratosis (AK) representing UV-damaged skin and squamous cell carcinoma (SCC), a UV-induced skin cancer. RESULTS: CRP1 expression increased by UVB radiation in primary but not in immortalized keratinocytes. Upon high, apoptosis-inducing doses of UV radiation, CRP1 was cleaved in a caspase-dependent manner. In normal skin, CRP1 was expressed in smooth muscle cells, vasculature, sweat glands, sebaceous glands and hair root sheath, but very little CRP1 was present in keratinocytes. CRP1 expression was elevated in basal cells in AK but not in SCC. CONCLUSION: CRP1 expression is regulated by UVB in human keratinocytes, suggesting a role for CRP1 in the phototoxic responses of human skin.

Expression profiles of matrix metalloproteinases and their inhibitors in colonic inflammation related to pediatric inflammatory bowel disease.

OBJECTIVE: The differential diagnosis of chronic colitis in inflammatory bowel disease (IBD) is challenging and a distinction between Crohn's disease (CD) and ulcerative colitis (UC) is not always possible. Matrix metalloproteinases (MMPs) cleave components of the extracellular matrix and their dysregulation leads to damage to the mucosa. They are involved in inflammation in IBD, as well as in eventual tissue repair. We aimed to examine putative differences in the profiles of MMPs and their tissue inhibitors [tissue inhibitors of metalloproteinase (TIMPs)] in pediatric IBD to find better tools for differential diagnosis of various IBD subgroups at the tissue level in the colon. MATERIAL AND METHODS: Expression of MMPs -1, -7, -8, -9, -10, -12 and -26 and TIMPs -1 and -3 was studied by immunohistochemistry in colonic tissue samples of 32 pediatric patients with IBD and 11 non-IBD cases. RESULTS: In the colon, expression of MMP-7 in epithelium was greater in CD samples compared to UC samples (1.09 versus 0.33; P = 0.010). Furthermore, epithelial MMP-10 expression was elevated in CD and UC samples compared to non-IBD samples (1.55 versus 1.00; P = 0.041 and 1.58 versus 1.00; P = 0.025, respectively). TIMP-3 expression in the stroma was higher in both the CD and UC groups when compared to non-IBD samples (2.18 versus 1.36; P = 0.026 and 2.50 versus 1.36; P = 0.002, respectively), but differences between UC and CD could not be observed. CONCLUSIONS: Increased expression of epithelial MMP-10 and stromal TIMP-3 could serve as histological indicators of IBD etiology. Epithelial MMP-7 expression, on the other hand, could help to differentiate between CD-related colitis and UC.

Tyrosine kinase 2 and interferon regulatory factor 5 polymorphisms are associated with discoid and subacute cutaneous lupus erythematosus.

Lupus erythematosus (LE) is a heterogeneous disease ranging from skin-restricted manifestations to a progressive multisystem disease. The specific skin lesions include chronic cutaneous, subacute cutaneous and acute cutaneous LE. Both genetic and environmental factors are involved in the development of LE. However, reports on the genetic background of cutaneous lupus erythematosus (CLE) forms, namely discoid (DLE) and subacute cutaneous lupus erythematosus (SCLE), are sparse. We investigated whether the known systemic LE (SLE) susceptibility genes also predispose to CLE. Altogether, 219 Finnish patients with DLE or SCLE and 356 healthy controls were recruited. Single nucleotide polymorphisms tagging reported risk genes were genotyped. Tyrosine kinase 2 (TYK2) rs2304256 was associated with increased risk of DLE (P = 0.012, OR = 1.47, 95% CI = 1.01-1.98). Expression of TYK2 was demonstrated by immunohistochemistry in macrophage-like cells and neutrophils and interferon regulatory factor 5 (IRF5) in macrophage- and fibroblast-like cells of DLE, SCLE and SLE skin. IRF5 rs10954213 showed association with DLE (P = 0.017, OR = 1.40, 95% CI = 1.06-1.86) and SCLE (P = 0.022, OR = 1.87, 95% CI = 1.09-3.21). A haplotype of cytotoxic T-lymphocyte-associated protein 4 (CTLA4) showed association with DLE (P = 0.0065, OR = 2.51, 95% CI = 1.25-5.04). Our results show that the TYK2, IRF5 and CTLA4 genes previously associated with SLE also confer risk for DLE and SCLE, suggesting that different LE subphenotypes may share pathogenetic pathways.

Identification of MAMDC1 as a candidate susceptibility gene for systemic lupus erythematosus (SLE).

BACKGROUND: Systemic lupus erythematosus (SLE) is a complex autoimmune disorder with multiple susceptibility genes. We have previously reported suggestive linkage to the chromosomal region 14q21-q23 in Finnish SLE families. PRINCIPAL FINDINGS: Genetic fine mapping of this region in the same family material, together with a large collection of parent affected trios from UK and two independent case-control cohorts from Finland and Sweden, indicated that a novel uncharacterized gene, MAMDC1 (MAM domain containing glycosylphosphatidylinositol anchor 2, also known as MDGA2, MIM 611128), represents a putative susceptibility gene for SLE. In a combined analysis of the whole dataset, significant evidence of association was detected for the MAMDC1 intronic single nucleotide polymorphisms (SNP) rs961616 (P -value = 0.001, Odds Ratio (OR) = 1.292, 95% CI 1.103-1.513) and rs2297926 (P -value = 0.003, OR = 1.349, 95% CI 1.109-1.640). By Northern blot, real-time PCR (qRT-PCR) and immunohistochemical (IHC) analyses, we show that MAMDC1 is expressed in several tissues and cell types, and that the corresponding mRNA is up-regulated by the pro-inflammatory cytokines tumour necrosis factor alpha (TNF-alpha) and interferon gamma (IFN-gamma) in THP-1 monocytes. Based on its homology to known proteins with similar structure, MAMDC1 appears to be a novel member of the adhesion molecules of the immunoglobulin superfamily (IgCAM), which is involved in cell adhesion, migration, and recruitment to inflammatory sites. Remarkably, some IgCAMs have been shown to interact with ITGAM, the product of another SLE susceptibility gene recently discovered in two independent genome wide association (GWA) scans. SIGNIFICANCE: Further studies focused on MAMDC1 and other molecules involved in these pathways might thus provide new insight into the pathogenesis of SLE.

Expression of MMP-10, MMP-21, MMP-26, and MMP-28 in Merkel cell carcinoma.

Merkel cell carcinoma (MCC) is an aggressive cutaneous tumor with poor outcome and increasing incidence. We examined by immunohistochemistry the expression of three novel matrix metalloproteinases (MMPs)-MMP-21, MMP-26, and MMP-28-in 44 primary MCC tumors and six lymph node metastases while MMP-10 served as a positive control. Their mRNA expression was also studied in the UISO MCC cell line basally and after various stimulations using quantitative real-time PCR. MMP-28 was observed in tumor cells of 15/44 samples especially in tumors <2 cm in diameter (p = 0.015) while 21/44 specimens showed MMP-28 in the tumor stroma. Expression of MMP-21 was demonstrated in tumor cells of 13/43 samples. MMP-26, instead, was positive in stromal cells (17/44) and its expression associated with tumors >or=2 cm in diameter (p = 0.006). Stromal expression of MMP-10 was the most frequent finding of the studied samples (31/44), but MMP-10 was detected also in tumor cells (17/44). Most of the metastatic lymph nodes expressed MMP-10 and MMP-26. MMP-10, MMP-21, and MMP-28 mRNAs were basally expressed by the UISO cells, and the corresponding proteins were detectable by immunostaining of cultured cells. IFN-alpha and TNF-alpha downregulated MMP-21 and MMP-28 expression. Our results suggest that novel MMPs may have a role in MCC pathogenesis: especially that MMP-26 expression in stroma is associated with larger tumors with poor prognosis. Expression of MMP-21 and MMP-28 seems to associate with the tumors of lesser malignant potential. We also confirm the previous finding on the role of MMP-10 in MCC pathogenesis.

Matrix metalloproteinase-26 is present more frequently in squamous cell carcinomas of immunosuppressed compared with immunocompetent patients.

BACKGROUND: Skin cancers are the most frequent malignancies in organ transplant recipients (OTRs). Squamous cell carcinomas (SCCs) occur 65-250 times more frequently in OTRs and tend to be aggressive in behavior. Because matrix metalloproteinases (MMPs) have a central role in tumorigenesis and invasion, we investigated the epithelial and stromal MMP and tissue inhibitor of MMP (TIMP) expression profile in SCCs of immunosuppressed (IS) compared with immunocompetent (IC) patients to determine if differences could explain the more aggressive behavior of SCCs in OTRs. METHODS: Matched pairs from 20 SCCs of IS and IC patients were studied using immunohistochemistry for MMP-1, MMP-7, MMP-8, MMP-9, MMP-13 and MMP-26 and TIMP-1 and TIMP-3. RESULTS: Among all MMPs studied, only staining for MMP-26 was significantly more intense in cancer cells of the post-transplant group compared with the IC group (p = 0.01), whereas MMP-9 expression was more abundant in stromal macrophages surrounding SCCs of IC patients (p = 0.02). MMP-26 expression in cancer cells (p = 0.04) and that of MMP-9 in neutrophils (p = 0.005) were more abundant in SCCs of patients using cyclosporine. CONCLUSIONS: We conclude that MMP-26 and MMP-9 may contribute to the more aggressive behavior of SCCs in OTRs.

Changes in matrix metalloproteinase (MMP) and tissue inhibitors of metalloproteinases (TIMP) expression profile in Crohn's disease after immunosuppressive treatment correlate with histological score and calprotectin values.

BACKGROUND: Matrix metalloproteinases (MMPs) constitute a family of enzymes capable of degrading various extracellular matrices (ECM) and basement membrane components playing a role in ECM turnover. They activate and degrade signaling molecules, such as cytokines and chemokines. MMPs are involved in inflammation and have been implicated in tissue degradation and repair occurring in inflammatory bowel disease. The aim of this study was to investigate the MMP profile of intestinal Crohn's disease (CD) patients before and after immunosuppressive treatment (anti-TNF-alpha agents or corticosteroids and conventional immunosuppressants azathioprine or methotrexate) to learn more about the therapeutic pathways for immunosuppressive agents. METHODS: Expression of MMP-1, MMP-7, MMP-9, MMP-10, and MMP-26 and tissue inhibitors of metalloproteinases (TIMP)-1 and TIMP-3 was studied by immunohistochemistry in pretreatment and post-treatment tissue samples. Semiquantitative immunohistochemical scores were tested for correlations with fecal and serum inflammation markers as well as endoscopic and clinical disease activity scores. RESULTS: Neutrophil MMP-9 (p = 0.039) and MMP-26 (p = 0.030) and stromal TIMP-1 (p = 0.041) and TIMP-3 (p = 0.029) decreased along with treatment. However, expression of TIMP-3 by enterocytes tended to increase. Total histological score demonstrated positive correlation with neutrophil MMP-9 (p = 0.000), MMP-26 (p = 0.014), and macrophage TIMP-1 (p = 0.001). Calprotectin followed a similar pattern with stromal MMP-26 (p = 0.011), TIMP-1 (p = 0.000), and TIMP-3 (p = 0.001). Crohn's disease endoscopic index of severity (CDEIS) value correlated positively with macrophage TIMP-1 (p = 0.007) and stromal TIMP-3 (p = 0.005). Epithelial TIMP-3 presented with negative correlations with CDEIS (p = 0.006) and C-reactive protein values (p = 0.004). CONCLUSIONS: Our results suggest that immunosuppressive drugs modulate disease activity in CD by downregulation of MMP-9 and MMP-26 positive neutrophils and stromal TIMP-1 and TIMP-3.

MMP-10 (Stromelysin-2) and MMP-21 in human and murine squamous cell cancer.

The squamous cell cancers (SCC) of renal transplant recipients are more aggressive and metastasize earlier than those of the non-immunocompromised population. Matrix metalloproteinases (MMPs) have a central role in tumor initiation, invasion and metastasis. Our aim was to compare the expression of MMPs-10, -12 and -21 in SCCs from immunosuppressed (IS) and control patients and the contribution of MMPs-10 and -21 to SCC development in the FVB/N-Tg(KRT5-Nfkbia)3Rto mouse line. Immunohistochemical analysis of 25 matched pairs of SCCs, nine of Bowen's disease and timed back skin biopsies of mice with selective inhibition of Rel/NF-kappaB signalling were performed. Semiquantitatively assessed stromal MMP-10 expression was higher (P = 0.009) in the control group when compared with IS patients. Tumor cell-derived MMP-10, -12 and -21 expression did not differ between the groups but stromal fibroblasts of the control SCCs tended to express MMP-21 more abundantly. MMP-10 expression was observed already in Bowen's disease while MMP-21 was absent. MMP-10 and -21 were present in inflammatory or stromal cells in ageing mice while dysplastic keratinocytes and invasive cancer were negative. Our results suggest that MMP-10 may be important in the initial stages of SCC progression and induced in the stroma relating to the general host-response reaction to skin cancer. MMP-21 does not associate with invasion of SCC but may be involved in keratinocyte differentiation.

Evidence for genetic association and interaction between the TYK2 and IRF5 genes in systemic lupus erythematosus.

OBJECTIVE: Several candidate genes have been implicated in susceptibility for systemic lupus erythematosus (SLE), a complex autoimmune disease. The proposed genes include members of the type I interferon (IFN) pathway and genes involved in immunological defense functions. Our aim was to systematically replicate 6 such genes, TYK2, IRF5, CTLA4, PDCD1, FCGR2A, and NOD2. METHODS: Single-nucleotide polymorphisms in TYK2, IRF5, CTLA4, PDCD1, FCGR2A, and NOD2 were genotyped in 277 SLE patients and 356 healthy controls from Finland, giving a power of 42%-70% for different genes at published allele frequencies. RESULTS: Significant association was seen for rs2304256 (p = 0.0001) and rs12720270 (p = 0.0031) in TYK2 and rs10954213 (p = 0.0043) in IRF5 in our samples, but not for the other genes. We found evidence for genetic interaction (p = 0.014) between rs2304256 in TYK2 and rs10954213 in IRF5, both members of the type I IFN pathway, strengthening the role of the type I IFN pathway in the pathogenesis of SLE. CONCLUSION: The IFN pathway genes IRF5 and TYK2 may act epistatically in increasing risk for SLE, but our lack of replication does not exclude effects of the other genes studied.

CCHCR1 is up-regulated in skin cancer and associated with EGFR expression.

Despite chronic inflammation, psoriatic lesions hardly ever progress to skin cancer. Aberrant function of the CCHCR1 gene (Coiled-Coil alpha-Helical Rod protein 1, HCR) within the PSORS1 locus may contribute to the onset of psoriasis. As CCHCR1 is expressed in certain cancers and regulates keratinocyte (KC) proliferation in a transgenic mouse model, we studied its relation to proliferation in cutaneous squamous cell cancer (SCC) cell lines by expression arrays and quantitative RT-PCR and in skin tumors by immunohistochemistry. CCHCR1 protein was detected in the pushing border of SCC and lining basal cell carcinoma islands. Different from psoriasis, Ki67 had a similar expression pattern as CCHCR1. The most intense CCHCR1 staining occurred in areas positive for epidermal growth factor receptor (EGFR). Expression of CCHCR1 mRNA was upregulated 30-80% in SCC lines when compared to normal KCs and correlated positively with Ki67 expression. The most aggressive and invasive tumor cell lines (RT3, FaDu) expressed CCHCR1 mRNA less than non-tumorigenic HaCaT cells. Moreover, the tumor promoters okadaic acid and menadione downregulated CCHCR1 mRNA. We conclude that both in psoriasis and the early stages of KC transformation, CCHCR1 may function as a negative regulator of proliferation, but beyond a certain point in oncogenesis cannot control this phenomenon any longer.

Stromelysin-1 and macrophage metalloelastase expression in the intestinal mucosa of Crohn's disease patients treated with infliximab.

BACKGROUND AND AIMS: The mechanism by which anti-tumor necrosis factor (TNF)-alpha therapy promotes rapid closure of fistulas and mucosal wound healing in Crohn's disease (CD) remains unclear. An ex-vivo model of gut T-cell mediated injury indicated that TNF-alpha blockade prevents tissue damage concomitant with matrix metalloproteinase (MMP) inhibition. We, therefore, hypothesized that the chimeric anti-TNF-alpha antibody infliximab facilitates wound healing in CD by downregulating tissue degrading MMPs. We focused on MMP-3 (stromelysin-1) and MMP-12 (macrophage metalloelastase) as these two enzymes have been linked to connective tissue destruction in CD. METHODS: Endoscopic biopsies were taken from 10 CD patients immediately before and after 10 weeks of treatment with infliximab. Before treatment, biopsies were taken from macroscopically inflamed areas, and after treatment were collected from the same locations as before treatment. The degree of mucosal damage was assessed by using a histological scoring system. MMP transcripts were detected by in-situ hybridization on paraffin sections. MMP proteins were determined by immunoblotting on mucosal homogenates. RESULTS: Six out of 10 patients had a clinical response to infliximab. MMP-3 and MMP-12 transcripts and proteins, which were highly expressed in CD inflamed mucosa, decreased after treatment in those patients who responded to infliximab. MMP-3 and MMP-12 downregulation was accompanied by a concomitant improvement of the histologic score. No change in MMP expression was found in nonresponders. CONCLUSION: The downregulation of tissue degrading MMPs in CD mucosa may explain the wound repair capacity of infliximab in healing fistulas and ulcers.

IL23R in the Swedish, Finnish, Hungarian and Italian populations: association with IBD and psoriasis, and linkage to celiac disease.

BACKGROUND: Association of the interleukin-23 receptor (IL23R) with inflammatory bowel disease (IBD) has been confirmed in several populations. IL23R also associates with psoriasis, suggesting that the gene may be an important candidate for many chronic inflammatory diseases. METHODS: We studied association of single-nucleotide variants in IL23R with IBD in Swedish patients, in both Crohn's disease (CD) and ulcerative colitis (UC) subsets. The same genetic variants were also studied in Finnish patients with psoriasis or celiac disease, and in Hungarian and Italian patients with celiac disease. RESULTS: Association of IL23R with IBD was replicated in our Swedish patients, and linkage and association of the IL23R region with psoriasis was found in the Finnish population. The IL23R region was also linked to celiac disease in Finnish families, but no association of IL23R variants with celiac disease was found in the Finnish, Hungarian or Italian samples. CONCLUSION: Our study is the first to demonstrate association of IL23R with CD and UC in Swedish patients with IBD. It is also the first study to report linkage and association of the IL23R region with psoriasis in the Finnish population. Importantly, this is the first report of linkage of the IL23R region to celiac disease, a chronic inflammatory condition in which IL23R has not been previously implicated.

Association of psoriasis to PGLYRP and SPRR genes at PSORS4 locus on 1q shows heterogeneity between Finnish, Swedish and Irish families.

A susceptibility locus for psoriasis, PSORS4, has been mapped to chromosome 1q21 in the region of the epidermal differentiation complex. The region has been refined to a 115 kb interval around the loricrin (LOR) gene. However, no evidence of association between polymorphisms in the LOR gene and psoriasis has been found. Therefore, we have analysed association to three candidate gene clusters of the region, the S100, small proline-rich protein (SPRR) and PGLYRP (peptidoglycan recognition protein) genes, which all contain functionally interesting psoriasis candidate genes. In previous studies, the SPRR and S100 genes have shown altered expression in psoriasis. Also polymorphisms in the PGLYRP genes have shown to be associated with psoriasis. We genotyped altogether 29 single nucleotide polymorphisms (SNPs) in 255 Finnish psoriasis families and analysed association with psoriasis using transmission disequilibrium test. A five-SNP haplotype of PGLYRP SNPs associated significantly with psoriasis. There was also suggestive evidence of association to SPRR gene locus in Finnish families. To confirm the putative associations, selected SNPs were genotyped also in a family collection of Swedish and Irish patients. The families supported association to the two gene regions, but there was also evidence of allelic heterogeneity.

Matrix metalloproteinase-21 expression is associated with keratinocyte differentiation and upregulated by retinoic acid in HaCaT cells.

In the skin, expression of several matrix metalloproteinases (MMPs) occurs in response to tissue injury, tumorigenesis, angiogenesis, apoptosis, and inflammation. The recently cloned MMP-21 has been implicated in skin development and various epithelial cancers. In this study, we found that it is also expressed by differentiated keratinocytes (KCs) in various benign skin disorders, in which it was not associated with KC apoptosis or proliferation, and in organotypic cultures. Furthermore, MMP-21 was induced in keratinocytes in association with increased calcium and presence of the differentiation marker filaggrin. In stably transfected A431 and HEK293 cell lines, MMP-21 increased invasion of cells but did not associate with increased apoptosis, proliferation, or epithelial-to-mesenchymal transition. Of various agents tested in HaCaT cell cultures, only retinoic acid (10(-6) M) and staurosporine (2.5 x 10(-8) M) upregulated MMP-21 mRNA and protein expression, whereas tumor promoters, hormones, or dexamethasone were without effect. Our results suggest that MMP-21 may be an important protease in the terminal differentiation of keratinocytes.

The PSORS1 locus gene CCHCR1 affects keratinocyte proliferation in transgenic mice.

The CCHCR1 gene (Coiled-Coil alpha-Helical Rod protein 1) within the major psoriasis susceptibility locus PSORS1 is a plausible candidate gene for the risk effect. We have previously generated transgenic mice overexpressing either the psoriasis-associated risk allele CCHCR1*WWCC or the normal allele of CCHCR1. All transgenic CCHCR1 mice appeared phenotypically normal, but exhibited altered expression of genes relevant to the pathogenesis of psoriasis, including upregulation of hyperproliferation markers keratins 6, 16 and 17. Here, we challenged the skin of CCHCR1 transgenic mice with wounding or 12-O-tetradecanoyl-13-acetate (TPA), treatments able to induce epidermal hyperplasia and proliferation that both are hallmarks of psoriasis. These experiments revealed that CCHCR1 regulates keratinocyte proliferation. Early wound healing on days 1 and 4 was delayed, and TPA-induced epidermal hyperproliferation was less pronounced in mice with the CCHCR1*WWCC risk allele than in mice with the normal allele or in wild-type animals. Finally, we demonstrated that overexpression of CCHCR1 affects basal keratinocyte proliferation in mice; CCHCR1*WWCC mice had less proliferating keratinocytes than the non-risk allele mice. Similarly, keratinocytes isolated from risk allele mice proliferated more slowly in culture than wild-type cells when measured by BrdU labeling and ELISA. Our data show that CCHCR1 may function as a negative regulator of keratinocyte proliferation. Thus, aberrant function of CCHCR1 may lead to abnormal keratinocyte proliferation which is a key feature of psoriatic epidermis.

Differential expression of stromal MMP-1, MMP-9 and TIMP-1 in basal cell carcinomas of immunosuppressed patients and controls.

Matrix metalloproteinases (MMPs) have an important role in the initiation, growth, and invasion of malignant tumors. Basal cell cancer (BCC) is the most common human malignancy. The risk of BCC is 10-16 times higher among organ transplant recipients compared with the nontransplanted population. The aim of this study was to compare the expression of several MMPs and their tissue inhibitors (TIMPs) in BCCs from kidney transplant recipients and controls. Expression of MMPs-1, -7, -8, -9, -10, -13, -26, and TIMPs-1 and -3 was evaluated by immunohistochemistry in 25 samples of BCC of kidney transplant recipients and 25 matched controls representing superficial and nodular subtypes. No significant differences were detected in MMP expression of BCC tumor cells between immunocompetent and immunodeficient patients. However, MMPs-1 and -9 and TIMP-1 were expressed more frequently in stromal macrophages in the BCCs of immunocompetent patients. When tumor subtypes were compared irrespective of the patient group, more MMP-1-positive fibroblasts and MMP-9-positive neutrophils were detected in the superficial subtype, while stromal MMP-10 expression was more abundant in nodular tumors. Our results suggest that abundant peritumoral expression of TIMP-1 in non-immunocompromised patients limits ECM degradation permissive for cancer cell migration.