This work documents the first case of idiopathic AA amyloidosis in humans caused by mutation in the promoter region of SAA1 gene. Knowledge of the mechanism of the disease may be an indication for targeted treatment in the future. Mutations in the SAA1 promoter should be considered in all cases of idiopathic forms of AA amyloidosis in which neither the immune nor the inflammatory component of the disease are clearly present.

Tesis por compendio / [ES] Los ácidos grasos de cadena muy larga (VLC-FA; >C24), aunque presentes en pequeñas cantidades, juegan un importante papel para el correcto desarrollo y funcionalidad de los tejidos neurales en vertebrados, especialmente durante su desarrollo temprano. Sin embargo, a pesar de su aparente importancia, los estudios sobre estos compuestos en peces son escasos. La biosíntesis de los VLC-FA se lleva a cabo mediante las denominadas proteínas de elongación de los ácidos grasos de cadena muy larga 4 (Elovl4) y, en consecuencia, la dotación y la función de estas enzimas determinan la capacidad endógena que una determinada especie tiene para satisfacer las demandas fisiológicas de VLC-FA, especialmente durante su desarrollo temprano. Además, esta producción endógena de los ácidos grasos poliinsaturados de cadena muy larga (VLC-PUFA) es dependiente de los sustratos. Así, para su biosíntesis se requiere de ácidos grasos más cortos, es decir ácidos grasos poliinsaturados de cadena larga (LC-PUFA; C20-24) que actúen como precursores, los cuales son incorporados principalmente a través de la dieta. Teniendo esto en mente, el presente trabajo de investigación tuvo como objetivos caracterizar los genes elovl4 en dorada (Sparus aurata) y en lenguado senegalés (Solea senegalensis), determinar la función de sus correspondientes proteínas codificadas, así como analizar el patrón de expresión tisular de elovl4. Además, se ha investigado la regulación nutricional de los genes implicados en la biosíntesis de VLC-PUFA (elovl4a, elovl4b) y LC-PUFA (fads2, elovl5) durante las primeras etapas del ciclo de vida de ambas especies (larvas y poslarvas), mediante el uso de dietas adaptadas a cada etapa del desarrollo. Los resultados confirmaron que ambas especies de peces poseen dos genes elovl4 distintos, denominados elovl4a y elovl4b según su homología con sus ortólogos de pez cebra. Asimismo, los ensayos funcionales de sus correspondientes proteínas, llevados a cabo en levaduras, indicaron que tanto Elovl4a como Elovl4b tienen la capacidad de elongar los ácidos grasos precursores (C20-24) hasta VLC-FA en ambas especies. Sin embargo, Elovl4b mostró mayor actividad que Elovl4a para elongar todos los ácidos grasos poliinsaturados a productos de cadena más larga, especialmente de la serie n-3. Además, los resultados de expresión génica indicaron que, aunque fueron detectados transcritos de elovl4 en la mayoría de los tejidos analizados, ambos genes elovl4 se expresaron más intensamente en los tejidos neurales de ambas especies, como el cerebro y los ojos, que mostraron los niveles de expresión más altos de elovl4a y elovl4b, respectivamente. Además, los resultados procedentes de los ensayos de regulación nutricional indicaron que los genes fads2, elovl5, elovl4a y elovl4b pueden ser regulados a través del contenido en LC-PUFA presente en la dieta. Es importante destacar que elovl4a y elovl4b fueron regulados de manera distinta según las hipotéticas necesidades de VLC-PUFA asociadas, de manera específica, con cada etapa del desarrollo temprano y dependiendo de disponibilidad dietaria de LC-PUFA. Estos hallazgos pueden contribuir a alcanzar una mejor comprensión de la vía biosintética de los VLC-FA en los teleósteos marinos, resaltando así el papel crucial que los productos de Elovl4 desempeñan para el correcto desarrollo y mantenimiento de las funciones neurofisiológicas durante las primeras etapas del desarrollo de los peces. Asimismo, estos resultados pueden ayudar a esclarecer el mecanismo molecular que controla la biosíntesis de VLC-PUFA, así como a establecer sus requerimientos específicos a lo largo del desarrollo de los teleosteos marinos en función de la especie. De esta manera, se abre la posibilidad de incorporar con éxito fuentes lipídicas alternativas a través de una programación nutricional temprana que estimule la biosíntesis de los VLC-PUFA durante las primeras etapas de alimentación exógena. / [CA] Els àcids grassos de cadena molt llarga (VLC-FA; >C24), encara que presents en petites quantitats, juguen un important paper per al correcte desenvolupament i funcionalitat dels teixits neurals en vertebrats, especialment durant el seu desenvolupament inicial. No obstant, malgrat la seua aparent importància, els estudis sobre aquests compostos en peixos son escassos. La biosíntesi dels VLC-FA es porta a terme mitjançant les denominades proteïnes d'elongació dels àcids grassos de cadena molt llarga 4 (Elovl4) i, en conseqüència, la dotació i la funció d'aquests enzims determinen la capacitat endògena que una determinada espècie té per a satisfer les demandes fisiològiques de VLC-FA, especialment durant el seu desenvolupament inicial. A més, aquesta producció endògena dels àcids grassos poliinsaturats de cadena molt llarga (VLC-PUFA) és depenent dels substrats. Així, per a la seua biosíntesi es requereix d'àcids grassos més curts, és a dir àcids grassos poliinsaturats de cadena llarga (LC-PUFA; C20-24) que actuen com a precursors, els quals són incorporats principalment a través de la dieta. Tenint això en compte, el present treball de recerca va tindre com a objectius caracteritzar els gens elovl4 en orada (Sparus aurata) i llenguado (Solea senegalensis), determinar la funció de les seues corresponents proteïnes codificades, així com analitzar el patró d'expressió tissular de elovl4. A més, es va investigar la regulació nutricional dels gens implicats en la biosíntesi de VLC-PUFA (elovl4a, elovl4b) i LC-PUFA (fads2, elovl5), durant les primeres etapes del cicle de vida d'ambdues espècies (larves i poslarves), mitjançant l'ús de dietes adaptades a cada etapa del desenvolupament. Els resultats van confirmar que totes dues espècies de peixos posseeixen dos gens elovl4 diferents, denominats elovl4a i elovl4b segons la seua homologia amb els seus ortòlegs en peix zebra. Així mateix, els assajos funcionals de les corresponents proteïnes, duts a terme en llevats, van indicar que tant Elovl4a com Elovl4b tenen la capacitat d'elongar els àcids grassos precursors (C20-24) fins a VLC-FA en totes dues espècies. No obstant això, Elovl4b va mostrar major activitat que Elovl4a per a elongar tots els àcids grassos poliinsaturats (substrats) fins a productes de cadena més llarga, especialment de la sèrie n-3. A més, els resultats d'expressió gènica van indicar que, encara que van ser detectats trànscrits de elovl4 en la majoria dels teixits analitzats, tots dos gens elovl4 es van expressar més en teixits neurals de totes dues espècies, com el cervell i els ulls, que van mostrar els nivells d'expressió més alts d'elovl4a i elovl4b, respectivament. A més, els resultats procedents dels assajos de regulació nutricional van indicar que els gens fads2, elovl5, elovl4a i elovl4b poden ser regulats a través del contingut en LC-PUFA present en la dieta. És important destacar que elovl4a i elovl4b van ser regulats de manera diferent segons les hipotètiques necessitats de VLC-PUFA associades, de manera específica, amb cada etapa del desenvolupament inicial i depenent de la disponibilitat dietaria de LC-PUFA. Aquestes troballes poden contribuir a tenir una millor comprensió de la via biosintètica dels VLC-FA en els teleostis marins, ressaltant així el paper crucial que els productes d'Elovl4 exerceixen en el correcte desenvolupament i manteniment de les funcions neurofisiològiques durant les primeres etapes del desenvolupament dels peixos. De la mateixa forma, aquests resultats poden ajudar a esclarir el mecanisme molecular que controla la síntesi endògena de VLC-PUFA, així com a establir els requisits específics de cada espècie al llarg del desenvolupament dels teleostis marins. D'aquesta manera, s'obri la possibilitat d'incorporar amb èxit fonts lipídiques alternatives a través d'una programació nutricional inicial que estimuli la biosíntesi de VLC-PUFA durant les primeres etapes d'alimentació exògena. / [EN] Very long-chain fatty acids (VLC-FA; >C24), although present in small amounts, play important roles for the correct development and functionality of neural tissues, especially during early development of vertebrates. However, despite their putative importance, their study in fish is scarce. Biosynthesis of VLC-FA is carried out by the so-called elongation of very long-chain fatty acid 4 (Elovl4) proteins and, consequently, the complement and function of these enzymes determine the endogenous capacity that a given species has for satisfying the physiological demands for VLC-FA, especially during its early development. Moreover, this endogenous production of very long-chain polyunsaturated fatty acid (VLC-PUFA) is substrate-dependent. Therefore, shorter fatty acid precursors, i.e. long-chain polyunsaturated fatty acids (LC-PUFA; C20-24), are required. These nutrients are mostly incorporated by the diet and their bioavailability can influence the capacity of Elovl4 for satisfying the physiological VLC-PUFA demands in marine fish. Thus, nutritional regulation of elovl4, as well as other elongase and desaturase genes involved in LC-PUFA biosynthesis (elovl5, fads2) has been proposed as a strategy to enhance endogenous production of LC-PUFA and VLC-PUFA in fish farming. The present thesis aimed to characterize elovl4 genes from the marine teleosts Sparus aurata and Solea senegalensis, to determine the function of the corresponding encoded proteins, and to analyze the tissue expression pattern of these genes. Moreover, we investigated the nutritional regulation of genes involved in the biosynthesis of the VLC-PUFA (elovl4a, elovl4b) and the LC-PUFA (fads2, elovl5) in early life-cycle stages (larvae and post-larvae) of both fish species fed diets adapted to each development stage. Live preys were supplied to larvae (early and late larvae) and microdiets for post-larvae, with a variable content in VLC-PUFA precursors, i.e. LC-PUFA. The results confirmed that both fish species possess two distinct elovl4 genes termed as elovl4a and elovl4b based on their homology to the zebrafish orthologs. Functional assays of the corresponding proteins in yeast denoted that Elovl4a and Elovl4b from both species have the capability to elongate C20-24 fatty acid precursors to VLC-FA products. However, Elovl4b appeared to have a higher activity than Elovl4a elongating all the polyunsaturated fatty acid substrates assayed to longer chain polyunsaturated products, especially those of the n-3 series. Moreover, gene expression results indicated that, although elovl4 transcripts were detected in most of the tissues analyzed, elovl4 genes were more strongly expressed in the neural tissues of both species, such as brain and eyes, which showed the highest expression levels of elovl4a and elovl4b, respectively. Furthermore, the results from nutritional regulation assays denoted that fads2, elovl5, elovl4a and elovl4b genes could be regulated by the dietary LC-PUFA content. It is important to highlight that elovl4a and elovl4b genes were differently regulated according to the species-specific VLC-PUFA putative needs, associated with each early life-stage and the LC-PUFA dietary availability. Importantly, these findings can contribute to a better understanding of the VLC-FA biosynthetic pathway in marine teleosts, highlighting the crucial role that the Elovl4 products carry out for the correct development and maintenance of neurophysiological functions during early stages of the fish development. Therefore, these results can help to elucidate the molecular mechanism controlling the VLC-PUFA biosynthesis and their species-specific requirements along the marine fish development, opening the possibility to incorporate successfully alternative lipid sources, through an early nutritional programming that stimulates the VLC-PUFA biosynthesis during the first exogenous feeding stages. / Para desarrollarel trabajo de investigación descrito en esta memoria, Miguel Torres Rodríguez recibió una beca predoctoral de la Excma. Diputación de Castellón. / Torres Rodríguez, M. (2021). Estudio de los patrones de expresión de genes implicados en la síntesis de ácidos grasos de cadena muy larga durante el desarrollo de la dorada y el lenguado, y su regulación nutricional [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/166619 / Compendio

Tuberculosis (TB) is an infectious and fatal disease that ranks as the second leading killer worldwide. It is caused by Mycobacterium tuberculosis (Mtb) which is an obligate intracellular parasite that colonizes the alveolar macrophages of the immune system. The major health concern associated with TB is its co-infection with HIV and the development of strains with multi-drug resistance. The elimination of TB has been hindered due to the lack of understanding of the survival strategies used by this pathogen. Thus, research towards discovering new effective antibacterial drugs is necessary and a group of Mtb kinase enzymes were targeted in this study because these enzymes are crucial for metabolism, pathogenesis and, hence, the survival of Mtb. Kinases are a group of structurally distinct and diverse proteins that catalyze the transfer of the phosphate group from high energy donor molecules such as ATP (or GTP) to a substrate. The phosphorylation of proteins modifies the activity of specific proteins which is subsequently used to control complex cellular processes within Mtb. The starting point of this research targeted eight specific Mtb kinases namely; Nucleoside diphosphokinase, Homoserine kinase, Acetate kinase, Glycerol kinase, Thiamine monophosphate kinase, Ribokinase, Aspartokinase and Shikimate kinase. The aim of this project was to subclone the gene sequences for these eight recombinant Mtb kinases and express them in Escherichia coli, to purify the proteins and determine their activity. In the effort to find new lead compounds, the final stage of this study focused on the basic screening of the TB kinases against an extract prepared from Pelargonium sidoides, a medicinal plant, to identify any inhibitory effects. Although this traditional medicinal plant has been broadly researched and extensively used to treat TB, there is still a lack of understanding of this plant’s scientific curative effect. Various molecular and biochemical methods were used to achieve the aims of this project. The putative gene sequence was obtained from the annotated genome of H37Rv, deposited at NCBI as NC_000962.2. The genes encoding the kinases were successfully PCR-amplified from genomic DNA, cloned into an expression vector in-frame with a C- or N-terminal 6-histidine-tag and expressed in E. coli BL21 (DE3). The purification of the protein was complex, but various different methods and techniques were explored to obtain sufficient amounts of protein. The functional characterization of the kinases involved an HPLC enzyme assay that showed that the recombinant kinases were active. These enzymes were then screened against the potential inhibitory compounds in P. sidoides using enzyme assays to generate dose-response curves. This allowed an effective comparison not only of the Mtb kinases’ activity under normal conditions but also the kinases’ activity in the presence of a potential inhibitor. Overall, the inhibition of the enzymes required the presence of higher concentrations of the P. sidoides extract. However, the SK enzyme results presented a significantly higher inhibition and the lowest IC50 value, in comparison to the other kinases, which makes this kinase an attractive potential drug target against TB. In summation, cloning and purification of SK was successful, resulting in a concentration of 2030 μg/ml of purified enzyme and its activity analysis demonstrated enzyme functionality. This activity was reduced to zero in the presence of 1 x 102 mg/ml dilution of P. sidoides plant extract. This research conducted has extended the quality of information available in this field of study. These interesting results, proposing and identifying SK as a suitable potential target can be a starting point to significantly contribute and progress in this field of research, with the eventual goal of developing a drug to combat this fatal disease. / Life Sciences / M. Sc. (Life Sciences)

Tuberculosis (TB) is an infectious and fatal disease that ranks as the second leading killer worldwide. It is caused by Mycobacterium tuberculosis (Mtb) which is an obligate intracellular parasite that colonizes the alveolar macrophages of the immune system. The major health concern associated with TB is its co-infection with HIV and the development of strains with multi-drug resistance. The elimination of TB has been hindered due to the lack of understanding of the survival strategies used by this pathogen. Thus, research towards discovering new effective antibacterial drugs is necessary and a group of Mtb kinase enzymes were targeted in this study because these enzymes are crucial for metabolism, pathogenesis and, hence, the survival of Mtb. Kinases are a group of structurally distinct and diverse proteins that catalyze the transfer of the phosphate group from high energy donor molecules such as ATP (or GTP) to a substrate. The phosphorylation of proteins modifies the activity of specific proteins which is subsequently used to control complex cellular processes within Mtb. The starting point of this research targeted eight specific Mtb kinases namely; Nucleoside diphosphokinase, Homoserine kinase, Acetate kinase, Glycerol kinase, Thiamine monophosphate kinase, Ribokinase, Aspartokinase and Shikimate kinase. The aim of this project was to subclone the gene sequences for these eight recombinant Mtb kinases and express them in Escherichia coli, to purify the proteins and determine their activity. In the effort to find new lead compounds, the final stage of this study focused on the basic screening of the TB kinases against an extract prepared from Pelargonium sidoides, a medicinal plant, to identify any inhibitory effects. Although this traditional medicinal plant has been broadly researched and extensively used to treat TB, there is still a lack of understanding of this plant’s scientific curative effect. Various molecular and biochemical methods were used to achieve the aims of this project. The putative gene sequence was obtained from the annotated genome of H37Rv, deposited at NCBI as NC_000962.2. The genes encoding the kinases were successfully PCR-amplified from genomic DNA, cloned into an expression vector in-frame with a C- or N-terminal 6-histidine-tag and expressed in E. coli BL21 (DE3). The purification of the protein was complex, but various different methods and techniques were explored to obtain sufficient amounts of protein. The functional characterization of the kinases involved an HPLC enzyme assay that showed that the recombinant kinases were active. These enzymes were then screened against the potential inhibitory compounds in P. sidoides using enzyme assays to generate dose-response curves. This allowed an effective comparison not only of the Mtb kinases’ activity under normal conditions but also the kinases’ activity in the presence of a potential inhibitor. Overall, the inhibition of the enzymes required the presence of higher concentrations of the P. sidoides extract. However, the SK enzyme results presented a significantly higher inhibition and the lowest IC50 value, in comparison to the other kinases, which makes this kinase an attractive potential drug target against TB. In summation, cloning and purification of SK was successful, resulting in a concentration of 2030 μg/ml of purified enzyme and its activity analysis demonstrated enzyme functionality. This activity was reduced to zero in the presence of 1 x 102 mg/ml dilution of P. sidoides plant extract. This research conducted has extended the quality of information available in this field of study. These interesting results, proposing and identifying SK as a suitable potential target can be a starting point to significantly contribute and progress in this field of research, with the eventual goal of developing a drug to combat this fatal disease. / Life Sciences / M. Sc. (Life Sciences)