Evangelia Skarmoutsou

State of the art in antigen retrieval for immunohistochemistry

The masking effects of antigens by chemical fixation, processing, embedding media interactions, represent a serious problem for immunohistochemical purposes. Fortunately, different approaches in antigen retrieval exist. These techniques are relatively recent and continuously expanding. This review focuses on the present state of the art in antigen retrieval methods for immunohistochemistry in light and electron microscopy. Moreover, a brief discussion on the chemical aspects of fixation, mechanism of retrieval, as well as its efficacy, is given.

Genetic polymorphisms of FOXP3 in Italian patients with systemic sclerosis.

A case control study to evaluate the possible influence of FOXP3 polymorphisms (rs3761548 and rs2280883) in the susceptibility of systemic sclerosis in an Italian Caucasian population. Subgroup analysis was also performed to test association between these SNPs and specific disease phenotypes. The study groups consisted of 467 individuals: 228 patients (194 with limited cutaneous form and 34 with diffuse cutaneous form of the disease) and 239 healthy control subjects. Genotyping was performed by high resolution melting analysis. Genotype distribution and allele frequency of the FOXP3 polymorphisms were analyzed statistically, using χ(2) or Fisher exact test. Single-marker analysis of allelic and genotype frequencies revealed that SNP rs3761548 was not associated with systemic sclerosis susceptibility. Analysis of genotype and allele distributions of the rs2280883 genetic variant was associated, only in female subjects with systemic sclerosis, its limited subtype, and anti-centromere autoantibodies. Although these findings require replication in a larger set and other populations, FOXP3 rs2280883 may represent a novel susceptibility locus for systemic sclerosis in female subjects.

Expression and localisation of osteopontin and prominin-1 (CD133) in patients with endometriosis

In this study, we investigated the expression and localisation of the proteins, osteopontin (OPN) and prominin-1 (CD133), as well as the plasma OPN levels in the endometrium of patients with endometriosis. Samples of ectopic endometriotic lesions and normal endometrium were obtained from 31 women with endometriosis and 28 healthy control subjects. The mRNA and protein expression of OPN and CD133 was analysed by real-time RT-PCR and immunohistochemistry. The plasma levels of OPN were determined by ELISA. Our results revealed that OPN mRNA and protein expression, as well as its release in the blood, was significantly increased in the endometriotic lesions in comparison to normal tissue. Although the presence of CD133+ cells was detected in the normal endometrium, as well as in the endometriosis specimens, a significant quantitative variation of this protein was not demonstrated in the patients with endometriosis. In conclusion, our data indicate that OPN is involved in the development of endometriosis by enhancing the invasiveness, proliferation and survival of endometrial cells in ectopic lesions. CD133 cannot be used as a disease marker for endometriosis, although an involvement of this protein in the pathogenesis of endometriosis cannot be excluded.

The sex bias in systemic sclerosis: on the possible mechanisms underlying the female disease preponderance.

Systemic sclerosis is a multifactorial and heterogeneous disease. Genetic and environmental factors are known to interplay in the onset and progression of systemic sclerosis. Sex plays an important and determinant role in the development of such a disorder. Systemic sclerosis shows a significant female preponderance. However, the reason for this female preponderance is incompletely understood. Hormonal status, genetic and epigenetic differences, and lifestyle have been considered in order to explain female preponderance in systemic sclerosis. Sex chromosomes play a determinant role in contributing to systemic sclerosis onset and progression, as well as in its sex-biased prevalence. It is known, in fact, that X chromosome contains many sex- and immuno-related genes, thus contributing to immuno tolerance and sex hormone status. This review focuses mainly on the recent progress on epigenetic mechanisms—exclusively linked to the X chromosome—which would contribute to the development of systemic sclerosis. Furthermore, we report also some hypotheses (dealing with skewed X chromosome inactivation, X gene reactivation, acquired monosomy) that have been proposed in order to justify the female preponderance in autoimmune diseases. However, despite the intensive efforts in elucidating the mechanisms involved in the pathogenesis of systemic sclerosis, many questions remain still unanswered.

Evaluation of circulating CD4+CD25+ and liver-infiltrating Foxp3+ cells in HCV-associated liver disease

In hepatitis C virus (HCV)-associated liver disease, the immune system is unable to clear the viral infection. Previous studies have raised the possibility of an involvement of regulatory T cells (Tregs). In this study, we analysed the peripheral blood from 30 patients with HCV-associated chronic liver disease and 20 healthy controls by flow cytometry for the evaluation of the Treg population [CD4⁺CD25hi forkhead box protein 3 (Foxp3)⁺], as well as the activated/effector CD4⁺ T cells (CD4⁺CD25low) and IFN-γ-secreting cells. We also analysed liver biopsies of the patients by immunohistochemical evaluation of Foxp3⁺ cells. Our results showed higher proportions of CD4⁺CD25low and IFN-γ⁺ cells in the patients than in the controls. By contrast, the proportions of peripheral CD4⁺CD25hi cells did not significantly differ. The 11 patients displaying Foxp3⁺ cells in the liver infiltrates showed significantly higher proportions of peripheral CD4⁺CD25low cells. Moreover, we found lower serum transaminase levels in the patients than in the controls, as shown by Foxp3⁺ immunohistochemistry, although these results were only statistically significant as regards alanine transaminase (ALT). In conclusion, these data suggest that the presence of Tregs infiltrating the liver is associated with high levels of activated/effector T cells in the peripheral blood and lower activity of hepatitis. Therefore, liver-infiltrating Tregs may play a role in limiting tissue damage and may thus support an effective immune response against HCV.

Liver immunolocalization and plasma levels of MMP-9 in non-alcoholic steatohepatitis (NASH) and hepatitis C infection

Non-alcoholic steatohepatitis (NASH) is a progressive fibrotic disease. Many issues related to the pathogenesis of this disease remain unresolved. Because of NASH association with the activation of liver fibrogenesis, we examined the plasma levels and liver immunolocalization of matrix metalloprotease-9 (MMP-9), a molecule involved in the remodelling processes of fibrogenesis. In addition, patients with chronic hepatitis C (HCV) were analyzed. Plasma concentrations of MMP-9 were determined by ELISA from peripheral blood and immunohistochemistry of the same protein was carried out in formalin-fixed and paraffin wax-embedded liver specimens. The mean value of circulating concentrations of MMP-9 in healthy controls was 39.7 ng/ml (SD: +/-4.6). In NASH and HCV-infected patients, MMP-9 concentrations were higher: 69.0 ng/ml (SD: +/-14.5) and 61.7 ng/ml (SD: +/-11.0), respectively. In NASH livers, MMP-9 was mainly immunolocalized on neutrophils, whereas in HVC-infected livers it was mainly localized over biliary canaliculi, bile ducts and hepatocyte cytoplasm. The different MMP-9 immunolocalization patterns in the examined diseases suggest the presence of a different pathophysiological involvement of this protease in the fibrogenesis underlying these diseases.

Insight into the role of microRNAs in brain tumors (Review)

MicroRNAs (MiRNAs) are small non-coding RNAs able to regulate gene expression at a posttranscriptional level. Recent evidence indicates that they play a crucial role in the initiation and progression of human cancers. In this review we briefly describe microRNA biogenesis and function, giving a more detailed account of the current state of knowledge concerning the role of microRNAs in brain tumors and stem-like tumor cells. MicroRNAs control brain tumor development by regulating multiple biological characteristics such as proliferation, invasion, differentiation and angiogenesis. Research in this field is rapidly spreading and encourages potential applications of microRNAs as diagnostic and prognostic tools, in addition to therapeutic targets and tools, to grant clinical benefits to patients suffering of brain tumors.

Analysis of matrix metalloproteinase-9 gene polymorphism -1562 C/T in patients suffering from systemic sclerosis with and without ulcers

The objective of this study was to determine whether the matrix metalloproteinase-9 (MMP-9) rs3918242 single nucleotide polymorphism may confer susceptibility to systemic sclerosis (SSc) with and without ulcers in an Italian Caucasian population. The MMP-9 rs3918242 functional polymorphism was genotyped in 461 subjects of Italian Caucasian origin: 228 patients with SSc (92 with and 136 without ulcers) and 233 unrelated healthy individuals. The SNP under study was in Hardy-Weinberg equilibrium in the control population. Genotype and allele distributions between SSc patients, with or without ulcers, were not statistically significant (p>0.05). A significant increase of the genotype C/T was observed in male SSc patients without ulcers when compared to patients with ulcers (P=0.04). The MMP-9 rs3918242 functional polymorphism is not associated with susceptibility to SSc. However, the presence of the polymorphism may have a protective effect on the development of ulcers in SSc male patients.

Effects of adalimumab, etanercept and ustekinumab on the expression of psoriasin (S100A7) in psoriatic skin

BACKGROUND Psoriasis is a chronic inflammatory skin disease. It is characterized by immune cell activation and altered epidermal differentiation. S100A7 (psoriasin) is overexpressed in psoriasis, suggesting a determinant role of this protein in inflammation and keratinocyte differentiation. OBJECTIVE The purpose of this study was to investigate the expression of S100A7 in the skin from psoriatic patients undergoing biological therapy with adalimumab, etanercept or ustekinumab. METHODS S100A7 expression and distribution were analyzed by immunohistochemistry. RESULTS S100A7, overexpressed in epidermal keratinocytes of psoriatic lesions, was downregulated, under the biological therapy with adalimumab, etanercept or ustekinumab, only in patients achieving a PASI score<15. CONCLUSIONS Dysregulation of S100A7 may represent a non-negligible player in the maintenance of psoriasis and the relative epidermal changes. Blockage of S100A7 may represent an additional therapeutic approach in the treatment of psoriasis.

Association of TIMP-1 +372 SNP with digital ulcer manifestation in female systemic sclerosis patients.

A candidate gene for TIMP-1 gene located on the X-chromosome (rs4898) was selected for a control case study to investigate a possible association of this SNP with the susceptibility to systemic sclerosis and its digit ulcer manifestation. A total of 461 individuals of Italian Caucasian origin (228 SSc patients and 233 healthy control subjects) were genotyped for TIMP-1 +372 T/C single nucleotide polymorphism rs4898. Subgroups were analyzed according to the presence or absence of digital ulcers. The CC genotype and C allele frequencies were significantly lower in female SSc patients than in controls (OR 0.53, CI 0.29-0.96, p=0.03 and OR 0.72, CI 0.53-0.98 p=0.04, respectively). CC genotypes frequency was lower also in female patients with ulcers than those without ulcers (OR 0.37, CI 0.14-1.00, p=0.03). Furthermore, CC genotype and C allele frequencies were lower also in female patients with ulcers in comparison to female healthy control subjects (OR 0.27, CI 0.10-0.70, p=0.004; OR 0.60, CI 0.40-0.89, p=0.01, respectively). The TIMP-1 rs4898 polymorphism may play a protective role in the susceptibility to SSC in females, and in particular to digital ulcer formation.