Neuro-ophthalmological and electrophysiological characterization of mitochondrial diseases.

Aims and methods: 1) characterization of patients with Dominant Optic Atrophy (DOA) associated with mutations in AFG3L2 and ACO2 genes in comparison with classical OPA1-DOA; 2) characterization of patients with mtDNA mutations causing MELAS and MERRF syndromes and correlation with heteroplasmy; 3) longitudinal evaluation of subacute m.11778G>A/MTND4 Leber’s Hereditary Optic Neuropathy (LHON) patients co-treated with rAAV2/2-ND4 gene therapy and idebenone. We performed a comprehensive neuro-ophthalmological assessment coupled with electrophysiological examination. Results: 1) We described and compared 23 ACO2 and 13 AFG3L2 patients with 72 OPA1 patients. All patients presented temporally predominant optic atrophy, with ACO2 showing higher RNFL and GCL thicknesses at OCT, while AFG3L2 was virtually-indistinguishable from OPA1. 2) Retinopathy was the most common manifestation in 17/33 MELAS patients, conversely, optic atrophy was the most common finding in 7/8 MERRF patients. Correlation of heteroplasmy with neuro-ophthalmological parameters failed to disclose any significance in MELAS, while it negatively correlated with OCT parameters in MERRF. 3) We compared modifications in visual acuity, OCT and electrophysiological parameters at 3 timepoints in 9 LHON patients. We observed significant decrease of RNFL thickness and reduction of PhNR amplitude. Visual acuity improved of about -0.37 LogMAR, correlating significantly with time from onset and from injection, but not with idebenone therapy duration. Discussion: 1) ACO2 seems associated to better preservation of retinal ganglion cells, depending on a different pathogenic mechanism involving mtDNA maintenance, as opposed to AFG3L2 which is involved in OPA1 processing. 2) MELAS and MERRF patients presented with a clearly distinct ocular phenotype, possibly reflecting a selective susceptibility of different retinal cell types to global energy defect or oxidative stress. 3) Follow up of LHON patients treated with gene therapy confirmed the deterioration in OCT and electrophysiological parameters, while the amount of visual improvement was similar to the one observed in recent clinical trials.

Effetto dell' ormone tiroideo (T3) durante ex vivo lung perfusion (EVLP) sul polmone di ratto: valutazione dell'azione protettiva nel danno da ischemia riperfusione.

La perfusione polmonare extracorporea (EVLP) è una tecnica utilizzata dal 2010 per valutare e migliorare la qualità dell'organo da trapiantare e il danno da ischemia-ripefusione (IRI). Tale perfusione utilizza la soluzione di Steen, la cui composizione è solo parzialmente nota. Lo scopo è quello di identificare gli effetti di T3 su IRI polmonare ex vivo, in un modello di ratto di donatore a cuore non battente. Animali (40) randomizzati in otto gruppi e il protocollo EVLP sono stati standardizzati nel nostro centro. Sono state valutate la funzione polmonare, PEEP, la resistenza vascolare polmonare totale a 45, 60, 120 e 180 minuti di EVLP per eseguire analisi di gas, dosaggio del mediatore di infiammazione, mitocondriale libero DNA, freeT3 e freeT4. Alla fine dei campioni di tessuto polmonare sono stati congelati dal dosaggio ATP, espressione genica, DNA mitocondriale, T3. Non date le concentrazioni del produttore, abbiamo analizzato gli acidi grassi liberi, vitamine, ormoni e composizione della soluzione Steen. Risultati La soluzione di steen contiene albumina umana x2 nel siero umano (7,5-8 g/dl): le concentrazioni di ft4 e ft3 sono x2 quelle nel siero umano e vengono rilasciati dall'albumina. La concentrazione di ft4 e ft3 non è cambiata durante l'EVLP. La Steen ha alta fluorescenza per l'alta concentrazione delle molecole aromatiche (ormoni) mai descritto in precedenza. NADH e mtDNA nel perfused aumenta con danno ischemico e nel gruppo trattato con T3 Conclusione Il modello EVLP è già convalidato nella perfusione nel trapianto polmonare, ma è necessario approfondire l'effetto della Steen in termini di ormoni e analiti. L'effetto sull'IRI dell'EVLP sembra essere influenzato negativamente da un T3 troppo alto in Steen, cosa che descriviamo per la prima volta. L'ulteriore aggiunta di T3 provoca disfunzione mitocondriale e infiammazione.

Applied genomics to monitor the genetic diversity and integrity of honey bee (Apis mellifera) populations and define sustainable strategies to benefit the beekeeping sector

Honey bees are considered keystone species in ecosystem, the effect of harmful pesticides for the honey bees, the action of extreme climatic waves and their consequence on honey bees health can cause the loss of many colonies which could contribute to the reduction of the effective population size and incentive the use of non-autochthonous queens to replace dead colonies. Over the last decades, the use of non-ligustica bee subspecies in Italy has increased and together with the mentioned phenomena exposed native honey bees to hybridization, laeding to a dramatic loss of genetic erosion and admixture. Healthy genetic diversity within honey bee populations is critical to provide tolerance and resistance to current and future threatening. Nowadays it is urgent to design strategies for the conservation of local subspecies and their valorisation on a productive scale. In this Thesis we applied genomics tool for the analysis of the genetic diversity and the genomic integrity of honey bee populations in Italy are described. In this work mtDNA based methods are presented using honey bee DNA or honey eDNA as source of information of the genetic diversity of A. mellifera at different level. Taken together, the results derived from these studies should enlarge the knowledge of the genetic diversity and integrity of the honey bee populations in Italy, filling the gap of information necessary to design efficient conservation programmes. Furthermore, the methods presented in these works will provide a tool for the honey authentication to sustain and valorise beekeeping products and sector against frauds.