RELATIONSHIP BETWEEN POLYMORPHISMS OF TAS2R38 BITTER TASTE RECEPTOR AND CHRONIC UPPER AIRWAY INFECTIONS

1Department of Neuroscience, ENT Section, “Federico II” University of Naples, Italy 2Department of Translational Medical Sciences, European Laboratory for Food Induced Diseases, Napoli, Italy The presence of taste receptors in extra-oral tissues may suggest additional roles apart from taste perception. Recently, an increasing number of reports demonstrated that the bitter taste G-protein coupled receptors family T2R, expressed in ciliated epithelial cells of the respiratory tract, are able to detect bacterial products and to stimulate innate immune defense against pathogens. Most microbial agents, secretes chemical signals known as quorum-sensing molecules that regulate the expression of genes involved in biofilm formation, virulence and other vital processes for microorganisms. Among the quorum-sensing molecules, the AHLs produced by P. aeruginosa, activate the receptor for bitter T2R38 expressed in ciliated epithelial cells of the respiratory tract, whereas mutants of P. aeruginosa lacking the AHL are not able to activate it. The activation of the receptor results in an increase of the Ca2+ flow and the ciliary beat frequency, as well as stimulating the production of NO which acts as a bactericide against the pathogen. The Caucasian population express three common polymorphisms (Pro49Ala, Ala262Val, Val296Ile) for TAS2R38 that lead to two major haplotypes PAV and AVI. The expression of either haplotype gives respectively 2 forms of receptors ̶ functional or non-functional ̶ i.e. unable to respond to specific agonists such phenylthiocarbamide and propylthiouracil (PROP). The two haplotypes PAV and AVI segregate into two major phenotypic classes: the "functional", sensitive to bitter, are homo- or heterozygous for the allele PAV, the "non-functional", are homozygous for the allele AVI. The genetic variations of the receptor TAS2R38 that affect sensitivity to bitter taste can help determine individual differences in susceptibility to bacterial infections of the respiratory tract allowing to plan a “target therapy”. Cellular cultures from homozygous PAV/PAV individuals showed a more effective NO production, mucociliary clearance and bactericide effect than cultures from AVI/PAV or AVI/AVI individuals. As a consequence it is reasonable to assume that patients with genotype AVI/PAV or AVI/AVI are at greater risk of contracting infections from gram-negative, compared with homozygous PAV. Some authors have studied the correlation between genotype and microbiological results TAS2R38 tissue of respiratory mucosa. The result of this analysis proved to be very interesting, because it showed a significant difference in the frequency of non-functional (AVI) than functional (PAV) among patients whose cultures were positive for Gram-negative bacteria, including P. aeruginosa. The aim of the study was to characterize phenotypically the sensitivity to PROP and the receptor polymorphisms of TAS2R38, in patients with chronic or recurrent infections of the upper respiratory tract to identify high risk patients. The identification of high-risk individuals would allow to draw up protocols for specific follow-up and appropriate “target therapy”

Characterization of Two Transposable Elements and an Ultra-Conserved Element Isolated in the Genome of Zootoca vivipara (Squamata, Lacertidae)

: Transposable elements (TEs) constitute a considerable fraction of eukaryote genomes representing a major source of genetic variability. We describe two DNA sequences isolated in the lizard Zootoca vivipara, here named Zv516 and Zv817. Both sequences are single-copy nuclear sequences, including a truncation of two transposable elements (TEs), SINE Squam1 in Zv516 and a Tc1/Mariner-like DNA transposon in Zv817. FISH analyses with Zv516 showed the occurrence of interspersed signals of the SINE Squam1 sequence on all chromosomes of Z. vivipara and quantitative dot blot indicated that this TE is present with about 4700 copies in the Z. vivipara genome. FISH and dot blot with Zv817 did not produce clear hybridization signals. Bioinformatic analysis showed the presence of active SINE Squam 1 copies in the genome of different lacertids, in different mRNAs, and intronic and coding regions of various genes. The Tc1/Mariner-like DNA transposon occurs in all reptiles, excluding Sphenodon and Archosauria. Zv817 includes a trait of 284 bp, representing an amniote ultra-conserved element (UCE). Using amniote UCE homologous sequences from available whole genome sequences of major amniote taxonomic groups, we performed a phylogenetic analysis which retrieved Prototheria as the sister group of Metatheria and Eutheria. Within diapsids, Testudines are the sister group to Aves + Crocodylia (Archosauria), and Sphenodon is the sister group to Squamata. Furthermore, large trait regions flanking the UCE are conserved at family level

Head and Neck squamocellular carcinomas: E-cadherin and Keratin 5 as biomolecular markers

E- Cadherin is a transmembranar protein that plays an important role in the cellular adhesion and insure the connection of the tissue cells; it is present in the epithelial cells and its aberrant expression is correlated with different kinds of head and neck squamocellular carcinoma. Keratin 5 (K5) is present in the basal layer of a stratified squamous keratinized and non keratinized epithe-lium. The purpose of the present study was to identify the expression particularities of E-cadherin and Keratin 5 in rapport with the localization and the differentiation of various head and neck squamocellular carcinomas (larynx, pharynx, hard palate, tongue, submandibular, lip, gingival sulcus, nasal pyramid, maxillary, zygomatic). Immunoreactions for E-cadherin in the tumoral cells were examined according to the this score: 0 (0% positive cells), 1 (30%). The presence of maximum score (value 3) of E-cadherin was found in well-differentiated squamocellular carcinomas of laryngeal, tongue, lip, nasal pyramid, zygomatic area origin. A lower value of the score was present in the less differentiated histopathological type. The role of E-cadherin in the squamocellular carcinomas is far from being clarified. It seems that the trials to estimate a prognosis in this clinical entity should include a combination between the molecular markers, the histopathological data and clinical parameters. K5 expression was observed in all squamocellular carcinomas included in the present study with scores between 1 and 3. For well and moderately differentiated histopathological types, a maximum score of 3 was recorded for all of the cases, not including the laryngeal area, which presented a score of 2. The following scores were identified in the regions of the poorly differentiated carcinomas: Jaw, 3; gingival sulcus, 2; and tongue and submandibular area, 1. The present study confirms the role of K5 in the definition of the differentiation of squamocellular carcinoma of head and neck revealing a differential expression depending on the anatomic site of the primary tumor. These observations may aid with an improved stratification of head and neck squamocellular carcinoma, thus improving the diagnosis and treatment strategies for this type of cancer

Karyological and genetic variation in Middle Eastern lacertid lizards, Lacerta laevis and the Lacerta kulzeri complex: a case of chromosomal allopatric speciation

Abstract Karyological (standard and C, Ag-NOR and Alu-I banding methods) and mtDNA analyses (cytochrome b and 12S rRNA) were conducted on specimens from eight allopatric populations of the Lacerta kulzeri complex. Parallel analyses were performed for comparison on Lacerta laevis specimens. Karyological and molecular studies support the morphological and ethological evidence indicating the speci¢c separation between Lacerta laevis and Lacerta kulzeri. In the Lacerta kulzeri complex, chromosomal analysis substantiated an interpopulation di¡erentiation roughly along a north^south trend, mainly regarding the sex chromosome morphology and heterochromatin. The cytochrome b and 12S rRNA gene analyses showed minor genetic di¡erences that were considerably smaller than those commonly found in genetically isolated populations. The L. kulzeri populations from Barouk, Druze and Hermon show a mean genetic distance that, in other saurians, characterises subspecies. The conditions found in L. laevis and L. kulzeri are reminiscent of King's model of chromosomal primary allopatry and support the hypothesis that in these lacertid lizards chromosome variations can become ¢xed before the accumulation of the genetic mutations

Anatomia Comparata

Anatomia comparata: alla ricerca dell’antenato comune. L’obiettivo primo dello studio anatomico comparativo è la ricostruzione della filogenesi, dei caratteri informativi di un’ascendenza comune, per acquisire le conoscenze sulla morfologia descrittiva e funzionale e per valutare i passaggi evolutivi per i diversi sistemi: in tre parole, forma, funzione ed evoluzione. Il volume presenta peculiari caratteristiche che lo rendono unico nel panorama editoriale: è nuovo e accattivante, per il linguaggio semplice e preciso; è duttile, perché risulta leggero senza essere superficiale, approfondito, ma mai ostico; è coinvolgente, perché la straordinaria eloquenza delle immagini, realizzate appositamente per l'opera, tocca livelli mai raggiunti in un testo di anatomia comparata; è aggiornato all’attualità delle conoscenze scientifiche. Un’altra caratteristica fondamentale dell’opera risiede nei contenuti digitali cui può accedere sia lo studente sia il docente. Sono disponibili filmati, lezioni on line, esperienze di laboratorio e un ampio database di domande a disposizione dei docenti e degli studenti. Inoltre, il docente potrà avere accesso a tutte le immagini in formato elettronico