Fabio D'Amico

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.

Detection of BRAF Gene Mutation in Primary Choroidal Melanoma Tissue

Numerous BRAF mutations have been detected in melanoma biopsy specimens and cell lines. In contrast, several studies report lack of BRAF mutations in uveal melanoma including primary and metastatic choroidal and ciliary body melanomas. To our knowledge, for the first time, here we report a case of choroidal melanoma harboring the BRAF mutation (V600E). The activation of RAF/MEK/ERK pathway, although independent of BRAF mutation, was reported in uveal melanoma. The presence of V600E mutation indicates that the RAF/MEK/ERK pathway, in addition to cutaneous melanoma progression, may play a role in the choroidal melanoma development.

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.

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.

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.

Obesity, Type 1 Diabetes, and Psoriasis: An Autoimmune Triple Flip.

Obesity, type 1 diabetes, and psoriasis are wide-ranging health problems. Genetics, epigenetics, and environmental factors together with immune disturbances are involved in these diseases. The white adipose tissue is an active endocrine organ, secreting a wide variety of soluble mediators called adipokines that have a central role in the relationship between adipose tissue and immune system. Inflammatory cytokines, including the IL-23/IL-17 and IL-18 axes, and microRNAs are involved in many processes, including immunity and inflammation, thus having a major role in the onset of these three diseases. In this review, we present an overview of the roles of adipokines, cytokines, and microRNAs in the pathogenesis and the progression of these three diseases.

FOXP3, ICOS and ICOSL gene polymorphisms in systemic sclerosis: FOXP3 rs2294020 is associated with disease progression in a female Italian population

Systemic sclerosis (SSc), an autoimmune disorder, is characterized by vasculopathy, inflammation, progressive perivascular and interstitial fibrosis. Its pathogenesis is largely unknown, however strong evidences suggest that genetic predisposition may contribute to SSc development. Several gene polymorphisms involved in regulatory T cell function have been identified in many autoimmune diseases, including SSc. Moreover, dysregulation of co-stimulatory and/or co-inhibitory signals, including ICOS signalling, can lead to autoimmunity. The aim of the present study was to investigate the association of the FOXP3 rs2294020, ICOS rs6726035 and ICOSL rs378299 SNPs with both the susceptibility and the progression to SSc in an Italian case-series of patients. SNP genotyping results were successfully obtained from a total of 350 subjects including 166 individuals with SSc and 184 healthy controls. Although analysis tests did not show any significant associations between the SNPs under study and susceptibility to SSc, the occurrence of FOXP3 rs2294020 in female patients was associated with decreased time to progression from early to definite SSc (allelic model: HR=1.43; CI=1.03-1.99; p=0.03; dominant model: HR=1.54; CI=1.04-2.28; p=0.03). The inclusion of presence of ACA autoantibodies in the model did not significantly change the estimates. No conclusions can be drawn for the susceptibility to the disease or the time to progression in men due to the low statistical power. This study provides evidence of the association of rs2294020 with SSc evolution in female patients, modulating the time of progression from the diagnosis of early SSc to the diagnosis of definite SSc, while no effect on SSc susceptibility per se was found. rs2294020 may be considered a disease-modifying gene-variant rather than a disease-susceptibility SNP in SSc.