Role of protease-activated receptor-2 in inflammation, and its possible implications as a putative mediator of periodontitis

Proteinase-activated receptor-2 (PAR2) belongs to a novel subfamily of G-protein-coupled receptors with seven-transmembrane domains. This receptor is widely distributed throughout the body and seems to be importantly involved in inflammatory processes. PAR2 can be activated by serine proteases such as trypsin, mast cell tryptase, and bacterial proteases, such as gingipain produced by Porphyromonas gingivalis. This review describes the current stage of knowledge of the possible mechanisms that link PAR2 activation with periodontal disease, and proposes future therapeutic strategies to modulate the host response in the treatment of periodontitis.

Polymorphisms of toll-like receptor 2 and 4 genes in Chagas disease

The aim of this study was to test the possible implication of toll-like receptor 2 (TLR2) and TLR4 gene polymorphisms in determining the susceptibility to Chagas' disease. Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism in 475 individuals from Colombia, 143 seropositive with chagasic cardiomyopathy, 132 seropositive asymptomatic and 200 seronegative. The TLR2 arginine to glutamine substitution at residue 753(Arg753Gln) polymorphism was absent in the groups analyzed. The TLR4 Asp299Gly and Thr399Ile polymorphisms are in linkage disequilibrium and we observed a very low frequency of these polymorphisms in our study population (2.6% and 1.8% respectively). The overall TLR2 and TLR4 alleles and genotype distribution in seronegative and seropositive were not significantly different. We compared the frequencies between asymptomatic patients and those with chagasic cardiomyopathy and we did not observe any significant differences in the distribution of alleles or genotypes. In summary, this study corroborates the low frequency of TLR2 and TLR4 polymorphisms observed in other populations and suggest that these do not play an important role in Chagas' disease. The validation of these findings in independent cohorts is needed to firmly establish a role for TLR2 and TLR4 variants in Chagas' disease.

Genetic polymorphisms in vitamin D receptor, vitamin D-binding protein, Toll-like receptor 2, nitric oxide synthase 2, and interferon-γ genes and its association with susceptibility to tuberculosis

Mycobacterium tuberculosis kills more people than any other single pathogen, with an estimated one-third of the world's population being infected. Among those infected, only 10% will develop the disease. There are several demonstrations that susceptibility to tuberculosis is linked to host genetic factors in twins, family and associated-based case control studies. In the past years, there has been dramatic improvement in our understanding of the role of innate and adaptive immunity in the human host defense to tuberculosis. To date, attention has been paid to the role of genetic host and parasitic factors in tuberculosis pathogenesis mainly regarding innate and adaptive immune responses and their complex interactions. Many studies have focused on the candidate genes for tuberculosis susceptibility ranging from those expressed in several cells from the innate or adaptive immune system such as Toll-like receptors, cytokines (TNF-α, TGF-β, IFN-γ, IL-1b, IL-1RA, IL-12, IL-10), nitric oxide synthase and vitamin D, both nuclear receptors and their carrier, the vitamin D-binding protein (VDBP). The identification of possible genes that can promote resistance or susceptibility to tuberculosis could be the first step to understanding disease pathogenesis and can help to identify new tools for treatment and vaccine development. Thus, in this mini-review, we summarize the current state of investigation on some of the genetic determinants, such as the candidate polymorphisms of vitamin D, VDBP, Toll-like receptor, nitric oxide synthase 2 and interferon-γ genes, to generate resistance or susceptibility to M. tuberculosis infection.

Diagnosis of iron deficiency anemia in children of Northeast Brazil

OBJECTIVE: To diagnose iron deficiency anemia in children. METHODS: The study was conducted with a sample of 301 children aged six to 30 months attending public daycare centers in the city of Recife, Northeast Brazil, in 2004. The diagnoses of anemia were based on a combination of different hematological and biochemical parameters: hemoglobin, mean corpuscular volume, ferritin, C-reactive protein, transferrin saturation and transferrin receptor. The chi-square test and ANOVA were used in the statistical analysis. RESULTS: Of all children studied, 92.4% had anemia (Hb <110 g/L) and 28.9% had moderate/severe anemia (Hb <90 g/L). Lower levels of hemoglobin were found in children aged 6-17 months. Iron deficiency was found in 51.5% of children using ferritin (<12 μg/L) as parameter. Taking into consideration the combination of hemoglobin level, ferritin and transferrin receptor, 58.1% had anemia with iron deficiency, 34.2% had anemia without iron deficiency and 2.3% had iron deficiency without anemia. Mean ferritin concentration was significantly higher in children with high C-reactive protein when compared with those with normal levels (22.1 vs. 14.8 µg/L). CONCLUSIONS: The use of several biochemical and hematological parameters allowed to diagnosing iron deficiency anemia in two thirds of children, suggesting a need to identify other determinants of anemia without iron deficiency.

TOLL-LIKE RECEPTORS (TLR) 2 AND 4 EXPRESSION OF KERATINOCYTES FROM PATIENTS WITH LOCALIZED AND DISSEMINATED DERMATOPHYTOSIS

There are few studies on the role of innate immune response in dermatophytosis. An investigation was conducted to define the involvement of Toll-Like Receptors (TLRs) 2 and 4 in localized (LD) and disseminated (DD) dermatophytosis due to T. rubrum. Fifteen newly diagnosed patients, eight patients with LD and seven with DD, defined by involvement of at least three body segments were used in this study. Controls comprised twenty skin samples from healthy individuals undergoing plastic surgery. TLR2 and TLR4 were quantified in skin lesions by immunohistochemistry. A reduced expression of TLR4 in the lower and upper epidermis of both LD and DD patients was found compared to controls; TLR2 expression was preserved in the upper and lower epidermis of all three groups. As TLR4 signaling induces the production of inflammatory cytokines and neutrophils recruitment, its reduced expression likely contributed to the lack of resolution of the infection and the consequent chronic nature of the dermatophytosis. As TLR2 expression acts to limit the inflammatory process and preserves the epidermal structure, its preserved expression may also contribute to the persistent infection and limited inflammation that are characteristic of dermatophytic infections.

Expression of TLR2 and TLR4 in lesions of patients with tegumentary american leishmaniasis

OBJECTIVES: The aim of this study was to describe the pattern of expression of Toll-like receptor 2 (TLR2) and Toll-like receptor 4 (TLR4) in skin biopsies of patients with American tegumentary leishmaniasis (ATL) caused by Leishmania braziliensis. METHODS: This prospective study evaluated 12 patients with ATL caused by Leishmania braziliensis confirmed by polymerase chain reaction. Immunohistochemistry was performed to determine the expression of TLR2 and TLR4. The number of NK cells, dendritic cells and macrophages in the tissue were calculated. The cytokine expression was determined using the anti-TNF-α, anti-IFN-Γ, anti-IL-1 and anti-IL-6. Double immunostaining reactions were used to determine the cell expressing TLR2 and TLR4. RESULTS: The numbers of cells expressing TLR2 and TLR4 were 145.48 ± 82.46 cell/mm² and 3.26 ± 4.11 cell/mm² respectively (p < 0.05). There was no correlation of TLR2 and TLR4 with the amount of cytokines and the number of NK cells, dendritic cells or macrophages. The double immunostaining revealed that TLR2 was expressed by macrophages. CONCLUSION: In human cutaneous leishmaniasis caused by Leishmania braziliensis, TLR2 is the most common TLR expressed during active disease, mainly by macrophages although without correlation with the amount of cytokines and number of cells.

Increased hepcidin expression in multibacillary leprosy

Iron is essential for all organisms and its availability can control the growth of microorganisms; therefore, we examined the role of iron metabolism in multibacillary (MB) leprosy, focusing on the involvement of hepcidin. Erythrograms, iron metabolism parameters, pro-inflammatory cytokines and urinary hepcidin levels were evaluated in patients with MB and matched control subjects. Hepcidin expression in MB lesions was evaluated by quantitative polymerase chain reaction. The expression of ferroportin and hepcidin was evaluated by immunofluorescence in paucibacillary and MB lesions. Analysis of hepcidin protein levels in urine and of hepcidin mRNA and protein levels in leprosy lesions and skin biopsies from healthy control subjects showed elevated hepcidin levels in MB patients. Decreases in haematologic parameters and total iron binding capacity were observed in patients with MB leprosy. Moreover, interleukin-1 beta, ferritin, soluble transferrin receptor and soluble transferrin receptor/log ferritin index values were increased in leprosy patients. Hepcidin was elevated in lepromatous lesions, whereas ferroportin was more abundant in tuberculoid lesions. In addition, hepcidin and ferroportin were not colocalised in the biopsies from leprosy lesions. Anaemia was not commonly observed in patients with MB; however, the observed changes in haematologic parameters indicating altered iron metabolism appeared to result from a mixture of anaemia of inflammation and iron deficiency. Thus, iron sequestration inside host cells might play a role in leprosy by providing an optimal environment for the bacillus.

Comparison of nuclear grade and immunohistochemical features in situ and invasive components of ductal carcinoma of breast

PURPOSE:To compare the prognostic and predictive features between in situ and invasive components of ductal breast carcinomas. METHODS:We selected 146 consecutive breast samples with ductal carcinoma in situ (DCIS) associated with adjacent invasive breast carcinoma (IBC). We evaluated nuclear grade and immunohistochemical expression of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), cytokeratin 5/6 (CK5/6), and epidermal growth factor receptor (EGFR) in both components, in situ and invasive, and the Ki-67 percentage of cells in the invasive part. The DCIS and IBC were classified in molecular surrogate types determined by the immunohistochemical profile as luminal (RE/PR-positive/ HER2-negative), triple-positive (RE/RP/HER2-positive), HER2-enriched (ER/PR-negative/HER2-positive), and triple-negative (RE/RP/HER2-negative). Discrimination between luminal A and luminal B was not performed due to statistical purposes. Correlations between the categories in the two groups were made using the Spearman correlation method. RESULTS:There was a significant correlation between nuclear grade (p<0.0001), expression of RE/RP (p<0.0001), overexpression of HER2 (p<0.0001), expression of EGFR (p<0.0001), and molecular profile (p<0.0001) between components in situ and IBC. CK 5/6 showed different distribution in DCIS and IBC, presenting a significant association with the triple-negative phenotype in IBC, but a negative association among DCIS. CONCLUSIONS: Our results suggest that classical prognostic and predictive features of IBC are already determined in the preinvasive stage of the disease. However the role of CK5/6 in invasive carcinoma may be different from the precursor lesions.

Chromogenic in situ hybridization compared with other approaches to evaluate HER2/neu status in breast carcinomas

Human epidermal growth factor receptor 2 (HER2) has been evaluated in breast cancer patients to identify those most likely to benefit from herceptin-targeted therapy. HER2 amplification, detected in 20-30% of invasive breast tumors, is associated with reduced survival and metastasis. The most frequently used technique for evaluating HER2 protein status as a routine procedure is immunohistochemistry (IHC). HER2 copy number alterations have also been evaluated by fluorescence in situ hybridization (FISH) in moderate immunoexpression (IHC 2+) cases. An alternative procedure to evaluate gene amplification is chromogenic in situhybridization (CISH), which has some advantages over FISH, including the correlation between HER2 status and morphological features. Other methodologies have also been used, such as silver-enhanced in situ hybridization (SISH) and quantitative real-time RT-PCR, to determine the number of HER2 gene copies and expression, respectively. Here we will present a short and comprehensive review of the current advances concerning HER2 evaluation in human breast cancer.

Structure-function relationships for the interleukin 2 receptor system

Receptors for interleukin 2 (IL-2) esit in at least three forms which differ in their subunit compositio, their affinity for ligand and their ability to mediate a cellular reponse. Type I receptors occur following cellular acitivation and consist of the 55,000 m. w. glycoprotein Tac. These receptors bind IL-2 with a low affinity, do not internalize ligand and have not been definitively associated with any response. Type II receptors, on the other hand, conssit of one or more glycoproteins of 70,000 m. w. which have been termed "beta ([beta]) chains." They bind IL-2 with an intermediate affinity and rapidly internalize the ligand. [Beta] proteins mediate many cellular IL-2-dependent reponses, including the short-term activation of natural killer cells and the induction of Tac protein expression. Type III receptors consist of a ternary complex of the Tac protein, the [beta] chain(s) and IL-2. They are characterized by a paricularly high affinity for ligand association. Type III receptors also internalize ligand and mediate IL-2-dependent responses at low factor concentrations. The identification of two independent IL-2-binding molecules, Tac and [beta], thus provides the elusive molecular explanation for the differences in IL-2 receptor affinity and suggests the potential for selective therapeutic manipulation of IL-2 reponses.

Inhibition of rotavirus ECwt infection in ICR suckling mice by N-acetylcysteine, peroxisome proliferator-activated receptor gamma agonists and cyclooxygenase-2 inhibitors

Live attenuated vaccines have recently been introduced for preventing rotavirus disease in children. However, alternative strategies for prevention and treatment of rotavirus infection are needed mainly in developing countries where low vaccine coverage occurs. In the present work, N-acetylcysteine (NAC), ascorbic acid (AA), some nonsteroidal anti-inflammatory drugs (NSAIDs) and peroxisome proliferator-activated receptor gamma (PPARγ) agonists were tested for their ability to interfere with rotavirus ECwt infectivity as detected by the percentage of viral antigen-positive cells of small intestinal villi isolated from ECwt-infected ICR mice. Administration of 6 mg NAC/kg every 8 h for three days following the first diarrhoeal episode reduced viral infectivity by about 90%. Administration of AA, ibuprofen, diclofenac, pioglitazone or rosiglitazone decreased viral infectivity by about 55%, 90%, 35%, 32% and 25%, respectively. ECwt infection of mice increased expression of cyclooxygenase-2, ERp57, Hsc70, NF-κB, Hsp70, protein disulphide isomerase (PDI) and PPARγ in intestinal villus cells. NAC treatment of ECwt-infected mice reduced Hsc70 and PDI expression to levels similar to those observed in villi from uninfected control mice. The present results suggest that the drugs tested in the present work could be assayed in preventing or treating rotaviral diarrhoea in children and young animals.

Indicadores de Prognóstico em Câncer de Mama com Axila Negativa: Receptor de Estrógeno e Expressão de P53 e de c-erbB-2

Objetivo: avaliar o valor prognóstico do receptor de estrógeno e da expressão das proteínas p53 e c-erbB-2 no câncer de mama com axila negativa. Métodos: foi realizado estudo imuno-histoquímico em material incluido em parafina, do arquivo do Instituto de Pesquisas Cito-Oncológicas (IPCO) da Fundação Faculdade Federal de Ciências Médicas de Porto Alegre (FFFCMPA), de 50 casos de câncer de mama sem comprometimento dos linfonodos axilares, em mulheres menopausadas, tratadas na Irmandade da Santa Casa de Porto Alegre (ISCMPA) e no Hospital Santa Rita de Porto Alegre (HSR) de janeiro 1990 a dezembro de 1994. Para análise estatística foram utilizados os testes de c² com correção de Yates, teste exato de Fisher e curvas de sobrevida pelo método de Kaplan-Meier comparados pelo teste log rank. O seguimento médio das pacientes foi de 3,6 anos (3,1-4,5). Dos 50 casos, 14 apresentaram recidiva no período observado. Resultados: a média de idade foi 61 anos (variação de 46 a 78 anos). A mastectomia radical modificada (MRM) foi realizada em 35 pacientes (70%) e 15 (30%) foram submetidas a setorectomia com esvaziamento axilar e posterior radioterapia. Metade das pacientes que apresentaram recidiva apresentaram-na nos três primeiros anos após o diagnóstico. O tamanho médio do tumor foi 2,8 cm (1,98-3,13) e o tipo histológico mais freqüente foi o carcinoma ductal infiltrante de tipo histológico não-especial (92%), conforme a graduação histológica de Bloom e Richardson, sendo 3 grau I (6,6%), 35 grau II (76%) e 8 grau III (17,4%); nos tumores que recidivaram não houve nenhum grau I, 9 (25,7%) eram grau II e 3 (37,5%) eram grau III. Em relação ao prognóstico, a taxa de intervalo livre de doença foi menor quando da associação de tumor pouco diferenciado (grau III) com receptor de estrógeno negativo (p = 0,006), p53 positivo (p = 0,006) e c-erbB-2 positivo (p = 0,001). Conclusão: mulheres menopausadas com câncer de mama sem comprometimento dos linfonodos axilares tem pior prognóstico, em relação ao intervalo livre de doença, quando apresentam associação de tumor pouco diferenciado com RE negativo, p53 positivo e c-erbB-2 positivo.

A novel polymorphism in the coding region of the vasopressin type 2 receptor gene

Nephrogenic diabetes insipidus (NDI) is a rare disease characterized by renal inability to respond properly to arginine vasopressin due to mutations in the vasopressin type 2 receptor (V2(R)) gene in affected kindreds. In most kindreds thus far reported, the mode of inheritance follows an X chromosome-linked recessive pattern although autosomal-dominant and autosomal-recessive modes of inheritance have also been described. Studies demonstrating mutations in the V2(R) gene in affected kindreds that modify the receptor structure, resulting in a dys- or nonfunctional receptor have been described, but phenotypically indistinguishable NDI patients with a structurally normal V2(R) gene have also been reported. In the present study, we analyzed exon 3 of the V2(R) gene in 20 unrelated individuals by direct sequencing. A C®T alteration in the third position of codon 331 (AGC®AGT), which did not alter the encoded amino acid, was found in nine individuals, including two unrelated patients with NDI. Taken together, these observations emphasize the molecular heterogeneity of a phenotypically homogeneous syndrome