c-myb Proto-Oncogene Is Expressed by Quiescent Scleroderma Fibroblasts and, Unlike B-myb Gene, Does Not Correlate With Proliferation

Systemic sclerosis (scleroderma) is characterized by excessive deposition of extracellular matrix constituents. Although it has been proposed that tissue fibrosis is due to increased fibroblast synthesis of various collagen polypeptides, there is some experimental evidence that patients with systemic sclerosis have a defect in the control of fibroblast growth. The myb family of genes includes, among others, the c-myb proto-oncogene and the structurally related gene, B-myb, which are both implicated in the regulation of differentiation and/or proliferation of hematopoietic and nonhematopoietic cells. To elucidate the molecular basis responsible for scleroderma fibroblast proliferation, we therefore elected to investigate the expression of c-myb and B-myb genes in scleroderma and control cells. Using the reverse transcriptase polymerase chain reaction technique, we detected c-myb transcripts in scleroderma skin fibroblasts rendered quiescent by serum deprivation. Under the game experimental conditions, c-myb message was not found in normal skin fibroblasts, but, after serum stimulation, c-myb RNA was clearly evident from 3 to 72h in both normal and pathologic cells. Treatment of these cells with c-myb antisense oligonucleotides caused downregulation of c-myb expression, and the inhibition of scleroderma fibroblast proliferation was 42%, whereas in normal fibroblasts the inhibition was weaker (22%). In contrast to c-myb, in normal and scleroderma fibroblasts the level of expression of B-myb correlated with cell proliferation assessed by cell count, and densitometric analysis showed that B-myb message was 1.5–5 times higher in most of pathologic cells studied. The antisense B-myb oligonucleotides had a weaker antiproliferative effect compared with antisense c-myb, inhibiting scleroderma and normal fibroblasts by 23% and 13%, respectively. These data suggest that the B-myb and c-myb genes may play a role in scleroderma fibroblast proliferation and function

Monocytes of Patients with Systemic Sclerosis (Scleroderma) Spontaneously Release In Vitro Increased Amounts of Superoxide Anion

It has been suggested that toxic oxygen free radicals can be involved in the pathogenesis of systemic sclerosis (scleroderma) (SSc). Because the cells that contribute to the generation of free radicals are not known, our aim was (i) to evaluate the ability of unmanipulated and phorbol 12-myristate 13-acetate-stimulated monocytes and polymorphonucleate neutrophils of SSc patients to generate superoxide anion (O2·–); and (ii) to investigate whether the O2·– produced by these cells involved the activation of nicotinamide-adenine dinucleotide diphosphate oxidase biochemical pathway. Employing the superoxide dismutase-inhibitable reduction of cytochrome c to evaluate the generation of O2·–, unmanipulated monocytes of SSc patients generated more O2·– than primary Raynaud’s phenomenon patients and normal control monocytes (p= 0.0001), and the release was higher in patients with diffuse cutaneous involvement and 5 y or less disease duration (p = 0.02). The involvement of nicotinamide-adenine dinucleotide diphosphate oxidase in the enhanced O2·– production was demonstrated by the finding that the cytosolic components of the enzyme, p47phox and p67phox, were both translocated to the plasma membrane of enriched but otherwise unmanipulated monocytes of SSc patients. The involvement of mitochondrial oxidases was excluded by the lack of inhibition of O2·– production when monocytes were incubated in the presence of rotenone, a mitochondrial oxidase inhibitor. Upon stimulation with phorbol 12-myristate 13-acetate, monocytes of SSc patients produced more O2·– than controls. In SSc patients untreated polymorphonucleate neutrophils generated significantly less O2·– than monocytes (p = 0.0001) and only slightly more than polymorphonucleate neutrophils of primary Raynaud’s phenomenon patients and normal controls (p = 0.03). In conclusion, we demonstrate that in patients with scleroderma, unmanipulated and phorbol 12-myristate 13-acetate-stimulated monocytes release in vitro increased amounts of superoxide anion through the activation of nicotinamide-adenine dinucleotide diphosphate oxidase and, thus, contribute to the oxidative stress found in this disease

Fas Signalling Promotes Intercellular Communication in T Cells

Cell-to-cell communication is a fundamental process for development and maintenance of multicellular organisms. Diverse mechanisms for the exchange of molecular information between cells have been documented, such as the exchange of membrane fragments (trogocytosis), formation of tunneling nanotubes (TNTs) and release of microvesicles (MVs). In this study we assign to Fas signalling a pivotal role for intercellular communication in CD4+ T cells. Binding of membrane-bound FasL to Fas expressing target cells triggers a well-characterized pro-apoptotic signalling cascade. However, our results, pairing up flow cytometric studies with confocal microscopy data, highlight a new social dimension for Fas/FasL interactions between CD4+ T cells. Indeed, FasL enhances the formation of cell conjugates (8 fold of increase) in an early time-frame of stimulation (30 min), and this phenomenon appears to be a crucial step to prime intercellular communication. Our findings show that this communication mainly proceeds along a cytosolic material exchange (ratio of exchange >10, calculated as ratio of stimulated cells signal divided by that recorded in control cells) via TNTs and MVs release. In particular, inhibition of TNTs genesis by pharmacological agents (Latruculin A and Nocodazole) markedly reduced this exchange (inhibition percentage: >40% and >50% respectively), suggesting a key role for TNTs in CD4+ T cells communication. Although MVs are present in supernatants from PHA-activated T cells, Fas treatment also leads to a significant increase in the amount of released MVs. In fact, the co-culture performed between MVs and untreated cells highlights a higher presence of MVs in the medium (1.4 fold of increase) and a significant MVs uptake (6 fold of increase) by untreated T lymphocytes. We conclude that Fas signalling induces intercellular communication in CD4+ T cells by different mechanisms that seem to start concomitantly with the main pathway (programmed cell death) promoted by FasL

Comprehensive Cancer-Predisposition Gene Testing in an Adult Multiple Primary Tumor Series Shows a Broad Range of Deleterious Variants and Atypical Tumor Phenotypes.

Multiple primary tumors (MPTs) affect a substantial proportion of cancer survivors and can result from various causes, including inherited predisposition. Currently, germline genetic testing of MPT-affected individuals for variants in cancer-predisposition genes (CPGs) is mostly targeted by tumor type. We ascertained pre-assessed MPT individuals (with at least two primary tumors by age 60 years or at least three by 70 years) from genetics centers and performed whole-genome sequencing (WGS) on 460 individuals from 440 families. Despite previous negative genetic assessment and molecular investigations, pathogenic variants in moderate- and high-risk CPGs were detected in 67/440 (15.2%) probands. WGS detected variants that would not be (or were not) detected by targeted resequencing strategies, including low-frequency structural variants (6/440 [1.4%] probands). In most individuals with a germline variant assessed as pathogenic or likely pathogenic (P/LP), at least one of their tumor types was characteristic of variants in the relevant CPG. However, in 29 probands (42.2% of those with a P/LP variant), the tumor phenotype appeared discordant. The frequency of individuals with truncating or splice-site CPG variants and at least one discordant tumor type was significantly higher than in a control population (χ2 = 43.642; p ≤ 0.0001). 2/67 (3%) probands with P/LP variants had evidence of multiple inherited neoplasia allele syndrome (MINAS) with deleterious variants in two CPGs. Together with variant detection rates from a previous series of similarly ascertained MPT-affected individuals, the present results suggest that first-line comprehensive CPG analysis in an MPT cohort referred to clinical genetics services would detect a deleterious variant in about a third of individuals.JW is supported by a Cancer Research UK Cambridge Cancer Centre Clinical Research Training Fellowship. Funding for the NIHR BioResource – Rare diseases project was provided by the National Institute for Health Research (NIHR, grant number RG65966). ERM acknowledges support from the European Research Council (Advanced Researcher Award), NIHR (Senior Investigator Award and Cambridge NIHR Biomedical Research Centre), Cancer Research UK Cambridge Cancer Centre and Medical Research Council Infrastructure Award. The University of Cambridge has received salary support in respect of EM from the NHS in the East of England through the Clinical Academic Reserve. The views expressed are those of the authors and not necessarily those of the NHS or Department of Health. DGE is an NIHR Senior Investigator and is supported by the all Manchester NIHR Biomedical Research Centre

Biologic Therapy in Inflammatory Eye Conditions (Ophtalmology): Safety Profile

Non-infectious uveitis can be a potentially sight threatening disease. Very recently, therapeutic strategies have turned towards a new methodology, which includes biologic agents. The introduction of biologic drugs has started a Copernican revolution in ophthalmology: biologic therapies represent a revolutionary option for those patients who present non-responder, sight threatening uveitis. The availability of these therapies has improved the uveitis outcome. The present review shows the most relevant medical literature on biologic agents in ophthalmology, such as tumor necrosis factor blockers, anti-interleukins and other related biologics. Several papers reported the efficacy of biologic agents in a large number of refractory uveitides, which suggest a promising role of biologic drugs for selected cases. On the other hand, the medical literature does not have consistent numbers yet, which hopefully will validate the promising preliminary results. Biologic agents are not only promising drugs for the treatment of non-responder uveitis, but also they show an apparently favourable safety profile, although several topics remain unsolved: it is still not clear when commence the treatment, which agent to choose, and the length of biologic therapy. Moreover, the high costs and the still not clear safety profile have very often limited their use only for severe, non-responder uveitis in highly specialized uveitis centres