Molecular genetics of inherited cystic kidney diseases: new diagnostic approaches

Background. Hhereditary cystic kidney diseases are a heterogeneous spectrum of disorders leading to renal failure. Clinical features and family history can help to distinguish the recessive from dominant diseases but the differential diagnosis is difficult due the phenotypic overlap. The molecular diagnosis is often the only way to characterize the different forms. A conventional molecular screening is suitable for small genes but is expensive and time-consuming for large size genes. Next Generation Sequencing (NGS) technologies enables massively parallel sequencing of nucleic acid fragments. Purpose. The first purpose was to validate a diagnostic algorithm useful to drive the genetic screening. The second aim was to validate a NGS protocol of PKHD1 gene. Methods. DNAs from 50 patients were submitted to conventional screening of NPHP1, NPHP5, UMOD, REN and HNF1B genes. 5 patients with known mutations in PKHD1 were submitted to NGS to validate the new method and a not genotyped proband with his parents were analyzed for a diagnostic application. Results. The conventional molecular screening detected 8 mutations: 1) the novel p.E48K of REN in a patient with cystic nephropathy, hyperuricemia, hyperkalemia and anemia; 2) p.R489X of NPHP5 in a patient with Senior Loken Syndrome; 3) pR295C of HNF1B in a patient with renal failure and diabetes.; 4) the NPHP1 deletion in 3 patients with medullar cysts; 5) the HNF1B deletion in a patient with medullar cysts and renal hypoplasia and in a diabetic patient with liver disease. The NGS of PKHD1 detected all known mutations and two additional variants during the validation. The diagnostic NGS analysis identified the patient’s compound heterozygosity with a maternal frameshift mutation and a paternal missense mutation besides a not transmitted paternal missense mutation. Conclusions. The results confirm the validity of our diagnostic algorithm and suggest the possibility to introduce this NGS protocol to clinical practice.

Anomalie cerebellari fetali: confronto tra ecografia e risonanza magnetica prenatale e follow up a distanza

Cerebellar malformation are increasingly diagnosed in utero. To assess the effectiveness of ultrasound and fetal magnetic resonance in the antenatal prediction of long term neurodevelopmental delay. STUDY DESIGN: We collected 105 cases of cerebellum malformation in the period 2000-2010 in Bologna and Bari University. Classification included cystic anomalies of posterior fossa and cerebellar hypoplasia. RESULTS: The greater group included Blake’s pouch cysts and mega cisterna magna cases (58/105). These cases seemed to have a good prognosis with a good outcome both in association with other anomalies and isolated. In cases of Dandy Walker malformation, vermis hypoplasia and cerebellum hypoplasia there were few survivors, so it was so difficult to outline some conclusion for child outcome. Despite great neuroimaging advances, in our study, ultrasound and MR reached a similar sensitivity (62-63%) for the diagnosis of posterior fossa anomalies, but the number of MR was lower compared with ultrasonography. CONCLUSION: Ultrasonography remains the screening method of choice for evaluation of cerebellum anatomy but probably MR imaging can improve some details expecially in the third trimester. Despite the data on Dandy Walker, vermis hypoplasia and cerebellum hypoplasia were conflicting and uncertain, for Blake and mega cisterna magna we can considered a rather good outcome.

Timing per l'inserimento in lista dei pazienti affetti da fibrosi cistica che necessitano di trapianto polmonare: casistica di un centro regionale di riferimento

Timing of waiting list entrance for patients with cystic fibrosis in need of pulmonary transplant: the experience of a regional referral centre Objective: Evaluation of parameters that can predict a rapid decay of general conditions of patients affected by Cystic Fibrosis (CF) with no specific criteria to be candidate to pulmonary transplant. Material and methods: Fifteen patients with CF who died for complications and 8 who underwent lung transplantation in the 2000-2010 decade, were enrolled. Clinical data 2 years before the event (body max index, FEV1%, number of EV antibiotic treatments per year, colonization with Methicillin-resistant Staphylococcus aureus (MRSA), pseudomonas aeruginosa mucosus, burkholderia cepacia, pulmonary allergic aspergilosis) were compared among the 2 groups. Results: Mean FEV1% was significantly higher and mean number of antibiotic treatment was lower in deceased than in the transplanted patients (p<0.002 and p<0.001 respectively). Although in patients who died there were no including criteria to enter the transplant list 2 years before the exitus, suggestive findings such as low BMI (17.3), high incidence of hepatic pathology (33.3%), diabetes (50%), and infections with MRSA infection (25%), Pseudomonas aeruginosa (83.3%) and burkholderia cepacia (8.3%) were found with no statistical difference with transplanted patients, suggesting those patients were at risk of severe prognosis. In patients who died, females were double than males. Conclusion: While evaluating patients with CF, negative prognostic factors such as the ones investigated in this study, should be considered to select individuals with high mortality risk who need stricter therapeutical approach and follow up. Inclusion of those patients in the transplant waiting list should be taken into account.

Effect of estrogen suppression on lung function in pulmonary Lymphangioleiomyomatosis

Background: Lymphangioleiomyomatosis (LAM), a rare progressive disease, is characterized by the proliferation of abnormal smooth muscle cells (LAM cells) in the lung, which leads to cystic parenchymal destruction and progressive respiratory failure. Estrogen receptors are present in LAM cells. LAM affects almost exclusively women of childbearing age. These findings, along with reports of disease progression during pregnancy or treatment with exogenous estrogens, have led to the assumption that hormonal factors play an important role in the pathogenesis of LAM. So, various therapies aim at preventing estrogen receptors (ER) by lowering circulating estrogen levels, by trying to block ER activity, or by attempting to lower ER expression in LAM. Prior experience have yielded conflicting results. Objective: The goal of this study was to evaluate, retrospectively, the effect of estrogen suppression in 21 patients with LAM. Design: We evaluated hormonal assays, pulmonary function tests and gas-exchange at baseline and after 12, 24 and 36 months after initiating hormonal manipulation. Results: The mean yearly rates of decline in FEV1 and DLCO are lower than those observed in prior studies and just DLCO decline was statistically significant. We also found an improvement of mean value of FVC and PaO2. Conclusions: Estrogen suppression appears to prevent decline in lung function in LAM.

Sintesi di molecole biologicamente attive con tecniche chemoenzimatiche:beta-lattami, profeni e alfa-amminoacidi non naturali

Il progetto di ricerca di questa tesi è stato focalizzato sulla sintesi di tre classi di molecole: β-lattami, Profeni e α-amminonitrili, utilizzando moderne tecniche di sintesi organica, metodologie ecosostenibili e strategie biocatalitiche. I profeni sono una categoria di antiinfiammatori molto diffusa e in particolare abbiamo sviluppato e ottimizzato una procedura in due step per ottenere (S)-Profeni da 2-arilpropanali raceme. Il primo step consiste in una bioriduzione delle aldeidi per dare i relativi (S)-2-Aril Propanoli tramite un processo DKR mediato dall’enzima Horse Liver Alcohol Dehydrogenase. Il secondo, l’ossidazione a (S)-Profeni, è promossa da NaClO2 e TEMPO come catalizzatore. Con lo scopo di migliorare il processo, in collaborazione con il gruppo di ricerca di Francesca Paradisi all’University College Dublino abbiamo immobilizzato l’enzima HLADH, ottenendo buone rese e una migliore enantioselettività. Abbiamo inoltre proposto un interessante approccio enzimatico per l’ossidazione degli (S)-2-Aril Propanoli utilizzando una laccasi da Trametes Versicolor. L’anello β-lattamico è un eterociclo molto importante, noto per essere un interessante farmacoforo. Abbiamo sintetizzato nuovi N-metiltio beta-lattami, che hanno mostrato un’attività antibatterica molto interessante contro ceppi resistenti di Staphilococcus Aureus prelevati da pazienti affetti da fibrosis cistica. Abbiamo poi coniugato gruppi polifenolici a questi nuovi β-lattami ottenendo molecule antiossidanti e antibatteriche, cioè con attività duale. Abbiamo poi sintetizzato un nuovo ibrido retinoide-betalattame che ha indotto differenziazione si cellule di neuroblastoma. Abbiamo poi sfruttato la reazione di aperture dell’anello monobattamico tramite enzimi idrolitici, con lo scopo di ottenere β-amminoacidi chirali desimmetrizzati come il monoestere dell’acido β–amminoglutammico. Per quando riguarda gli α-amminonitrili, è stato sviluppato un protocollo di Strecker. Le reazioni sono state molto efficienti utilizzando come fonte di cianuro l’acetone cianidrina in acqua, utilizzando differenti aldeidi e chetoni, ammine primarie e secondarie. Per mettere a punto una versione asimmetrica del protocollo, abbiamo usato ammine chirali con lo scopo di ottenere nuovi α-amminonitrili chirali.

Il ruolo dell’ecografia prenatale nella diagnosi precoce delle anomalie fetali della fossa cranica posteriore

Obiettivo: Valutare il ruolo brainstem-vermis angle (BV angle) a 16-18 settimane per la diagnosi precoce delle anomalie cistiche della fossa cranica posteriore. Metodi: Uno studio prospettico, multicentrico, osservazionale. Volumi ecografici tridimensionali della testa fetale sono stati acquisiti in feti a 16-18 settimane. Tre operatori di simile esperienza hanno misurato il BV angle nel piano sagittale come precedentemente descritto1,2 e hanno annotato se il quarto ventricolo era aperto sul piano assiale. Un follow-up dettagliato è stato ottenuto in tutti i casi. Risultati: Tra novembre 2009 e marzo 2011, 150 volumi sono stati acquisiti ad un’epoca gestazionale media di 16 settimane. A causa di una scarsa qualità delle immaginai, 49 volumi sono stati esclusi, con una popolazione finale di 101 casi. Di questi, 6 hanno ricevuto successivamente una diagnosi di malformazione di Dandy-Walker (DWM) e 2 di cisti della tasca di Blake (BPC), gli altri erano normali. In tutti i feti con anomalie cistiche della fossa cranica posteriore, il BV angle è risultato significativamente più ampio rispetto ai controlli (57.3+23.0° vs 9.4+7.7°, U-Mann Whitney test p<0.000005). Nel 90.3% dei feti normali, il BV angle era <20° e il quarto ventricolo era chiuso sul piano assiale. In 9 feti normali e nei casi con BPC, l’angolo era >20° ma <45° (25.8+5.6°) e il quarto ventricolo era aperto posteriormente sul piano assiale, ma solo utilizzando una scansione non convenzionale. In tutti i feti con DWM, il BV angle era >45° (67.9+13.9°) e il quarto ventricolo era aperto anche sul piano assiale standard. Conclusioni: Fino ad ora la diagnosi di anomalie cistiche della fossa cranica posteriore è stata consideratea difficile o impossibile prima di 20 settimane, a causa del presunto sviluppo tardivo del verme cerebellare. La nostra esperienza suggerisce che la misurazione del BV angle consente un’identificazione precisa di queste condizioni già a 16 settimane.

Synthesis of new bioactive β-lactam compounds

New biologically active β-lactams were designed and synthesized, developing novel antibiotics and enzymatic inhibitors directed toward specific targets. Within a work directed to the synthesis of mimetics for RGD (Arg-Gly-Asp) sequence able to interact with αvβ3 and α5β1-type integrins, new activators were developed and their Structure-Activity Relationships (SAR) analysis deepened, enhancing their activity range towards the α4β1 isoform. Moreover, to synthesize novel compounds active both against bacterial infections and pulmonary conditions of cystic fibrosis patients, new β-lactam candidates were studied. Among the abundant library of β-lactams prepared, mainly with antioxidant and antibacterial double activities, it was identified a single lead to be pharmacologically tested in vivo. Its synthesis was optimized up to the gram-scale, and pretreatment method and HPLC-MS/MS analytical protocol for sub-nanomolar quantifications were developed. Furthermore, replacement of acetoxy group in 4-acetoxy-azetidinone derivatives was studied with different nucleophiles and in aqueous media. A phosphate group was introduced and the reactivity exploited using different hydroxyapatites, obtaining biomaterials with multiple biological activities. Following the same kind of reactivity, a small series of molecules with a β-lactam and retinoic hybrid structure was synthesized as epigenetic regulators. Interacting with HDACs, two compounds were respectively identified as an inhibitor of cell proliferation and a differentiating agent on steam cells. Additionally, in collaboration with Professor L. De Cola at ISIS, University of Strasbourg, some new photochemically active β-lactam Pt (II) complexes were designed and synthesized to be used as bioprobes or theranostics. Finally, it was set up and optimized the preparation of new chiral proline-derived α-aminonitriles through an enantioselective Strecker reaction, and it was developed a chemo-enzymatic oxidative method for converting alcohols to aldehydes or acid in a selective manner, and amines to relative aldehydes, amides or imines. Moreover, enzymes and other green chemistry methodologies were used to prepare Active Pharmaceutical Ingredients (APIs).

Simkania negevensis: clinical and laboratory studies in the population of hemodialized and kidney transplanted patients.

Simkania negevensis is a bacterium belonging to the order Chlamydiales but with certain biological characteristics different from those of chlamydia, according to which it was classified in the family Simkaniaceae. It is widespread in the environment, due to its ability to survive in amoebae also in phase cystic, for which it was hypothesized a possible transmission after contact with water in which they are present amoebae. So far it is known its role in diseases of the lower respiratory tract, such as childhood bronchiolitis and pneumonia in adults of the community, following its transmission through infected aerosols. A recent American study showed, by PCR, a high prevalence of S. negevensis in patients with lung transplant than other transplant recipients, assuming an association between the presence of the bacterium in these patients, and transplant rejection, were more frequent in lung transplant recipients infected compared to uninfected. There are no data so far analyzed in Italy relative to the population of dialysis and kidney transplant recipients relative to simkania negevensis why this study was undertaken in order to start a specific location and evaluate the scientific implications. Because its ability to assume persistent forms of infection, which may lead to a prolonged inflammatory response, Simkania negevensis, similar to other persistent bacteria or viruses, may be ivolved in pathologic complication. Sn may be a factor in graft rejection in mmunesuppressed lung transplant recipients, and further studies are planned to explore the posible association of Sn infections with various in vivo pathologies.