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Abstract: The experimental work of this thesis was performed at the International Centre for Genetic Engineering and Biotechnology (ICGEB) in the Human Molecular Genetics Group, under the scientific direction of Prof. Franco Pagani. The project was developed during the academic years 2014-2017. Modified U1 RNAs, also named Exon Specific U1s (ExSpeU1s) represent a novel class of small RNA-based molecules that correct exons splicing defects. To evaluate their therapeutic potential focused on Familial Dysautonomia (FD), a rare autosomal recessive disorder characterized by progressive degeneration of the sensory and autonomic nervous system. More than 99% of patients are homozygous for the T to C transition in position 6 of the IKBKAP intron 20 (c.2204+6T>C). This substitution modifies the exon 20 5’ splice site (5’ss) inducing exon skipping in a tissue-specific manner and reducing the total amount of IKAP protein. The molecular mechanisms underlying the IKBKAP mis-splicing are not completely clear and there are no effective treatments. In this thesis, I investigated the therapeutic potential of ExSpeU1s and the role of cis- and trans-acting factors that regulates IKBKAP splicing. Using a splicing functional assay, I identified ExSpeU1s that bind to intron 20 sequences and rescue the exon 20 skipping defect. Interestingly, their rescue activity was modulated by several splicing factors and requires a critical exonic splicing enhancer element. Transfection experiment showed the involvement of both enhancing (TIA1, PTBP1 and PTB4) and inhibitory (SRSF3, hnRNPA1, FOX and FUS) splicing factors in IKBKAP splicing. To better evaluate the ExSpeU1s therapeutic efficacy, I transduced FD patient’s fibroblasts with a lentiviral vector expressing the most active ExSpeU1. This resulted in a complete rescue of the exon skipping defect and improvement in IKAP protein expression. Most importantly, intraperitoneal delivery of ExSpeU1s by AAV9 into a transgenic mouse model, that recapitulates the tissue-specific mis-splicing seen in FD patients, corrected the aberrant splicing patterns in several tissues increasing the amount of the corresponding IKAP protein. All together, these results identify novel regulatory splicing factors involved in the IKBKAP exon 20 regulation and provide the proof of principle that ExSpeU1s delivered in vivo by AAV vectors represent a novel therapeutic strategy for FD.
Keywords: Familial Dysautonomia, IKBKAP, IKAP, splicing, splicing defects, ExSpeU1, U1 snRNA, mouse model, AAV
Published in RUNG: 26.03.2018; Views: 4391; Downloads: 124
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Abstract: In the thermal lens experimental set-up we replaced the commonly employed pump laser by a halogen lamp, combined with an interference lter, providing a tuneable, nearly monochromatic pump source over the range of wavelengths 430–710 nm. Counter-propagating pump and probe beams are used and a 1 mm path-length sam- ple cell together with the interference lter makes an optical cavity, providing ampli cation of the thermal lens signal, which leads to enhancement of the measurement sensitivity, and enables detection of absorbances on the order of 5×10− 6. Ampli ed thermal lens signal allows us to replace the typical lock-in ampli er and digital os- cilloscope with a silicon photodetector, Arduino board, and a personal computer, offering the possibility for a compact, robust and portable device, useful for in- eld absorption measurements in low concentration or weakly absorbing species. The use of a white light source for optical pumping, an interference lter for wavelength selection and direct diagnostic of the thermal lens signal increase the versatility of the instrument and simpli- es substantially the experimental setup. Determination of Fe(II) concentrations at parts per billion levels was performed by the described white-light thermal lens spectrophotometer and the absorption spectrum for 50μg/ L Fe(II)-1,10-phenanthroline was well reproduced with an average measurement precision of 4%. The obtained limits of detection and quantitation of Fe(II) determination at 510nm are 3μgL− 1 and 11μgL− 1, respectively. The calibration curve was linear in the concentration range of LOQ-500μgL− 1 with reproducibility between 2% and 6%, con rming that this instrument provides good spectrometric capabilities such as high sensitivity, tune- ability and good reproducibility. In addition, the versatility of the instrument was demonstrated by recording the photothermal spectrum of gold nanostructured material and determination of excitation wavelength with most ef cient optical to thermal energy conversion, which differs considerably (cca 100 nm) from the absorption maximum of the investigated sample.
Keywords: thermal lens spectrometry, Fe(II) determination, photothermal technique, multi-wavelength excitation
Published in RUNG: 21.02.2018; Views: 4126; Downloads: 0
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Abstract: In this work, new analytical approaches for determination of biogenic amines in wines were developed. For the first time, we studied the derivatization of BAs in wines with naphthalene- 2,3-dicarboxaldehyde (NDA) and with dabsyl chloride (DBS) and analysis of derivatized BAs by HPLC coupled to fluorescence (HPLC-NDA-FL) and thermal lens spectrometry (HPLC-DBS-TLS) detectors. The sensitivity of the two methods (LODs HPLC-NDA-FL in the range 27-73 μg/L; LODs HPLC-DBS-TLS in the range 3.4-11 μg/L) was higher than that of the official method for biogenic amines in wines, OIV-MA-AS315-18 (60-77 μg/L). For its best performances, the HPLC-DBS-TLS technique was applied to the analysis of putrescine, cadaverine, histamine and tyramine in two white wine samples. Additionally, exploiting the Berthelot reaction, the TLS fast screening of biogenic amines in wines, following the release of ammonia by transglutaminase, was also proposed. This approach allowed us to determine total biogenic amount content in concentrations below 0.1 mg/L, expressed as equivalents of histamine.
Keywords: biogenic amines, NDA, liquid chromatography, TLS, fluorescence, wine
Published in RUNG: 02.11.2017; Views: 4457; Downloads: 270
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Abstract: A novel, one-pot method was developed to synthesize gold nanoparticle composite from cellulose (CEL), wool keratin (KER) and chloroauric acid. Two ionic liquids, butylmethylimmidazolium chloride and ethylmethylimmidazolium bis(trifluoromethylsulfonyl)imide were used to dissolve CEL, KER and HAuCl4. X-ray diffraction and X-ray photoelectron results show that Au3+ was completely reduced to Au0NPs with size of (5.5 ± 1) nm directly in the composite with NaBH4. Spectroscopy and imaging results indicate that CEL and KER remained chemically intact and were homogeneously distributed in the com- posites with Au0NPs. Encapsulating Au0NPs into [CEL+KER] composite made the composite fully biocom- patible and their bactericidal capabilities were increased by the antibacterial activity of Au0NPs. Specifically, the [CEL+KER+Au0NPs] composite exhibited up to 97% and 98% reduction in growth of antibi- otic resistant bacteria such as vancomycin resistant Enterococcus faecalis and methicillin resistant Staphylococcus aureus, and was not cytotoxic to human fibroblasts. While [CEL+KER] composite is known to possess some antibacterial activity, the enhanced antibacterial observed here was due solely to added Au0NPs. These results together with our previous finding that [CEL+KER] composites can be used for con- trolled delivery of drugs clearly indicate that the [CEL+KER+Au0NPs] composites possess all required properties for successful use as dressing to treat chronic ulcerous infected wounds.
Keywords: Ionic liquid Green Sustainable Polysaccharide Keratin Wound dressing Gold nanoparticles Antibiotic-resistant bacteria
Published in RUNG: 27.09.2017; Views: 4407; Downloads: 0
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Keywords: AMPLIEFIED THERMAL LENS SPECTROMETRY, Fe2+
Published in RUNG: 30.08.2017; Views: 4380; Downloads: 0
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