Patrizio Arrigo

Downregulation of microRNA expression in the lungs of rats exposed to cigarette smoke

Although microRNAs have been investigated extensively in cancer research, little is known regarding their response to noxious agents in apparently healthy tissues. We analyzed the expression of 484 miRNAs in the lungs of rats exposed to environmental cigarette smoke (ECS) for 28 days. ECS down‐regulated 126 miRNAs (26.0%) at least 2‐fold and 24 miRNAs more than 3‐fold. We previously demonstrated that 107 of 4858 genes (2.9%) and 50 of 518 proteins (9.7%) were up‐regulated by ECS in the same tissue, which is consistent with the role of microRNAs as negative regulators of gene expression. The most remarkably down‐regulated microRNAs belonged to the families of let‐7, miR‐10, miR‐26, miR‐30, miR‐34, miR‐99, miR‐122, miR‐123, miR‐124, miR‐125, miR‐140, miR‐145, miR‐146, miR‐191, miR‐192, miR‐219, miR‐222, and miR‐223, which regulate stress response, apoptosis, proliferation, an‐giogenesis, and expression of genes. In contrast, miR‐294, an inhibitor of transcriptional repressor genes, was up‐regulated by ECS. There was a strong parallelism in dysregulation of rodent microRNAs and their human homologues, which are often transcribed from genes localized in fragile sites deleted in lung cancer. Five ECS‐down‐regulated microRNAs are known to be affected by single nucleotide polymorphisms. Thus, changes in microRNA expression are an early event following exposure to cigarette smoke.— Izzotti, A., Calin, G. A., Arrigo, P., Steele, V. E., Croce, C. M., De Flora, S. Downregulation of microRNA expression in the lungs of rats exposed to cigarette smoke. FASEB J. 23, 806–812 (2009)

Identification and characterization of a new human cDNA from chromosome 21q22.3 encoding a basic nuclear protein

Congenital heart disease (CHD) affects over 40% of Down syndrome (DS) patients. The region proposed to contain the gene(s) for DS CHD has been restricted to 21q22.2–22.3, from D21S55 to MX1. The identification and functional characterization of the genes mapping to this region is a necessary step to understand the pathogenesis of CHD in DS. In an effort to contribute to the construction of a transcriptional map of the DS CHD region we have performed direct cDNA selection using a YAC contig that maps between ETS2 and D21S15 and cDNAs synthetised from fetal heart structures. Here we describe the identification and characterization of a new gene, WRB, that maps to 21q22.3 between ACTL5 and HMG 14 and appears to be widely expressed in adult and fetal tissues. The new gene encodes a basic protein of unknown function containing a tryptophan-rich carboxyl-terminal region and a potential nuclear localization signal. Immunofluorescence analysis shows a predominant localization in the cell nucleus. The understanding of the biological function of the protein product should clarify the potential role of WRB in the pathogenesis of DS CHD.

Cloning a new human gene from chromosome 21q22.3 encoding a glutamic acid-rich protein expressed in heart and skeletal muscle

Abstract The identification and functional characterization of genes on chromosome 21 is a necessary step to understand the pathogenesis of the various phenotypic anomalies that affect Down syndrome patients. Using direct cDNA selection we have identified a new gene, SH3BGR, that maps to 21q22.3, proximal to HMG14, and is differentially expressed in heart and skeletal muscle. SH3BGR encodes a novel protein that is characterized by the presence of a proline-rich region containing the consensus sequence for a SH3-binding domain and by an acidic carboxyl-terminal region containing a glutamic acid-rich domain predicted to assume a coiled coil. The presence of two functional domains involved in protein-protein interactions suggests that SH3BGR could be part of a multimeric complex. Its overexpression might alter specific functions of muscular tissue and therefore take part in the pathophysiology of muscular hypotonia in Down syndrome.

Beta Caryophyllene and Caryophyllene Oxide, Isolated from Aegle Marmelos, as the Potent Anti-inflammatory Agents against Lymphoma and Neuroblastoma Cells

Aegle marmelos (Indian Bael) is a tree which belongs to the family of Rutaceae. It holds a prominent position in both Indian medicine and Indian culture. We have screened various fractions of Aegle marmelos extracts for their anticancer properties using in vitro cell models. Gas chromatography-Mass spectrometry (GC-MS) was employed to analyze the biomolecules present in the Aegle marmelos extract. Jurkat and human neuroblastoma (IMR-32) cells were treated with different concentrations of the fractionated Aegle marmelos extracts. Flow cytometric analysis revealed that optimal concentration (50 µg/ml) of beta caryophyllene and caryophyllene oxide fractions of Aegle marmelos extract can induce apoptosis in Jurkat cell line. cDNA expression profiling of pro-apoptotic and anti-apoptotic genes was carried out using real time PCR (RT-PCR). Down-regulation of anti-apoptotic genes (bcl-2, mdm2, cox2 and cmyb) and up-regulation of pro-apoptotic genes (bax, bak1, caspase-8, caspase-9 and ATM) in Jurkat and IMR-32 cells treated with the beta caryophyllene and caryophyllene oxide fractions of Aegle marmelos extract revealed the insights of the downstream apoptotic mechanism. Furthermore, in-silico approach was employed to understand the upstream target involved in the induction of apoptosis by the beta caryophyllene and caryophyllene oxide fractions of Aegle marmelos extract. Herein, we report that beta caryophyllene and caryophyllene oxide isolated from Aegle marmelos can act as potent anti-inflammatory agents and modulators of a newly established therapeutic target, 15-lipoxygenase (15-LOX). Beta caryophyllene and caryophyllene oxide can induce apoptosis in lymphoma and neuroblastoma cells via modulation of 15-LOX (up-stream target) followed by the down-regulation of anti-apoptotic and up-regulation of pro-apoptotic genes.

Potentially functional regions of nucleic acids recognized by a Kohonen's self-organizing map

Computer recognition of short functional sites on DNA, such as promoter regions or intron-exon boundaries, has recently attracted much interest. In this paper we have focused our attention on the automatic recognition of relevant features of human nucleic acid sequences by means of an unsupervised artificial neural network model. Sixty messenger RNA and 31 genomic DNA sequences were analysed. The results showed that in mRNA, the minimal similarity 60 base pattern was guanine- and cytosine-rich and located in most sequences in a range of 250 bases from either the middle point of the signal peptide coding region or from the start of the coding region. On DNA sequences a region defined by a cluster of minimal similarity patterns was present in many of the analysed genes. This zone may be related to alternative splicing and DNA methylation.

An integrated genomic and proteomic approach to identify signatures of endosulfan exposure in hepatocellular carcinoma cells

Present study reports the identification of genomic and proteomic signatures of endosulfan exposure in hepatocellular carcinoma cells (HepG2). HepG2 cells were exposed to sublethal concentration (15μM) of endosulfan for 24h. DNA microarray and MALDI-TOF-MS analyses revealed that endosulfan induced significant alterations in the expression level of genes and proteins involved in multiple cellular pathways (apoptosis, transcription, immune/inflammatory response, carbohydrate metabolism, etc.). Furthermore, downregulation of PHLDA gene, upregulation of ACIN1 protein and caspase-3 activation in exposed cells indicated that endosulfan can trigger apoptotic cascade in hepatocellular carcinoma cells. In total 135 transcripts and 19 proteins were differentially expressed. This study presents an integrated approach to identify the alteration of biological/cellular pathways in HepG2 cells upon endosulfan exposure.

Noncoding RNAs: Possible Players in the Development of Fluorosis

Fluorosis is caused by excess of fluoride intake over a long period of time. Aberrant change in the Runt-related transcription factor 2 (RUNX2) mediated signaling cascade is one of the decisive steps during the pathogenesis of fluorosis. Up to date, role of fluoride on the epigenetic alterations is not studied. In the present study, global expression profiling of short noncoding RNAs, in particular miRNAs and snoRNAs, was carried out in sodium fluoride (NaF) treated human osteosarcoma (HOS) cells to understand their possible role in the development of fluorosis. qPCR and in silico hybridization revealed that miR-124 and miR-155 can be directly involved in the transcriptional regulation of Runt-related transcription factor 2 (RUNX2) and receptor activator of nuclear factor κ-B ligand (RANKL) genes. Compared to control, C/D box analysis revealed marked elevation in the number of UG dinucleotides and D-box sequences in NaF exposed HOS cells. Herein, we report miR-124 and miR-155 as the new possible players involved in the development of fluorosis. We show that the alterations in UG dinucleotides and D-box sequences of snoRNAs could be due to NaF exposure.

Different Mutations in Three Prime Repair Exonuclease 1 and Ribonuclease H2 Genes Affect Clinical Features in Aicardi-Goutieres Syndrome

Aicardi-Goutières syndrome is a rare encephalopathy of mutational origin characterized by increased levels of interferon alpha in cerebrospinal fluid. The aim of this study was to explore the influence of different Aicardi-Goutières syndrome genotypes on the clinical course of patients, seeking to identify specific gene expression profiles able to explain Aicardi-Goutières syndrome phenotype differences. We detected the occurrence of Aicardi-Goutières syndrome mutations in 21 patients and compared microarray gene-expression data of cerebrospinal fluid lymphocytes with clinical variables. The levels of interferon alpha in cerebrospinal fluid were high in all patients; we found differences in the expression of genes encoding for Toll-like receptor, endogenous RNases, T lymphocyte activation, angiogenesis inhibition, and peripheral interferon alpha production. These results indicate that further to interferon alpha production in the central nervous system, a variety of other pathogenic mechanisms is activated in Aicardi-Goutières syndrome to various degrees in different patients, thus explaining the interindividual difference in Aicardi-Goutières syndrome course.

Effect of Environmental Chemical Stress on Nuclear Noncoding RNA Involved in Epigenetic Control.

In the last decade the role of noncoding RNAs (ncRNAs) emerges not only as key elements of posttranscriptional gene silencing, but also as important players of epigenetic regulation. New kind and new functions of ncRNAs are continuously discovered and one of their most important roles is the mediation of environmental signals, both physical and chemical. The activity of cytoplasmic short ncRNA is extensively studied, in spite of the fact that their function and role in the nuclear compartment are not yet completely unraveled. Cellular nucleus contains a multiplicity of long and short ncRNAs controlling at different levels transcriptional and epigenetic processes. In addition, some ncRNAs are involved in RNA editing and quality control. In this paper we review the existing knowledge dealing with how chemical stressors can influence the functionality of short nuclear ncRNAs. Furthermore, we perform bioinformatics analyses indicating that chemical environmental stressors not only induce DNA damage but also influence the mechanism of ncRNAs production and control.

Comparative Analysis of Rac1 Binding Efficiency With Different Classes of Ligands: Morpholines, Flavonoids and Imidazoles

The focal adhesion pathway has a great impact on cellular growth and survival. Its disregulation is correlated with the loss of cellular mechanical properties. Such modifications are, in many cases, associated with pathologies such as cancer and cardiovascular diseases. Actin remodeling is a critical reaction cascade embedded in focal adhesion pathway, and Rac1 is one of the proteins involved in actin remodeling. In order to design highly selective pharmacophores against this target, it is necessary to maximize the binding affinity of chemical entities against Rac1. To this purpose we propose an integrative chemo-bioinformatics tool to screen ligand specificity for a target protein. Our integrative workflow includes chemo-informatics data mining (Chemical System), structural bioinformatics and combined exploratory data analysis. We have applied this integrative chemo-bioinformatics workflow to a comparative analysis of three different classes of ligands (morpholines, flavonoids and imidazoles) against the Rac1 protein. Our analysis emphasizes the presence of several ligands that preferentially dock Rac1 in the domain that seems to be responsible for Rac1-phospholipase C gamma 1 interaction. Recent studies have highlighted the Rac1 and PLC interactions in platelet adhesion. Our study has highlighted the role of Rac1-PLC gamma1 interaction in cytoskeleton remodeling associated with cardiovascular diseases. Rac1 PLC interaction is Calcium dependent. This suggest that some of the analysed ligands, could be used to control the Calcium dependent cytoskeleton remodeling since they dock Rac1 in the switch 2 domain. Our results, in a nanotechnology perspective, also endorse the use Rac1s switch 2 domain suitable for new highly specific biosensors.