Title Utjecaj tirosola i kvercetina na indikatore starenja i redoks statusa u timeless cirkadijalnih mutanata Drosophille Title (english) Effects of tyrosol and quercetin on indicators of ageing and redox status in Drosophilla timeless circadian mutant Author Tamara Žic Mentor Rozi Andretić Waldowski (mentor)Committee member Rozi Andretić Waldowski (predsjednik povjerenstva)Committee member Sandra Kraljević Pavelić (član povjerenstva)Committee member Karlo Wittine (član povjerenstva)Granter University of Rijeka Defense date and country 2016-10-20, Croatia Scientific / art field, BIOTECHNICAL SCIENCES Abstract Ciklusi svjetla i mraka utječu na cirkadijalne gene koji su bitni za kontrolu homeostaze te su važan faktor koji utječu na fizičke i bihevioralne promjene u 24 satnom periodu. Geni koji reguliraju cirkadijalni ritam bitni su za regulaciju metabolizma i imaju veliki utjecaj na mehanizme starenja. Starenje je kompleksan proces kojega opisuju velike promjene u organizmu kao što su smanjenje funkcija stanica, veća podložnost bolestima i na kraju smrt. Jedna od teorija starenja povezuje starenje s nakupljanjem oksidacijskog oštećenja, a oksidativne promjene povezane su s regulacijom cirkadijalnih gena. Oksidacijski stres u obliku reaktivnih kisikovih vrsta utječe na oštećenje proteina, lipida i DNK koje onda dovodi do starenja. Pokazano je da mutacije u cirkadijalnom genu period (per) mogu dovesti do ubrzanog starenja, stoga smo testirali da li mutacija u tim01 genu, dimerizacijskom partneru per gena, kod Drosophile melanogaster dovodi do ubrzanih procesa starenja. Ispitali smo kako dodatak polifenola, kvercetina i tirosola, u prehranu ima utjecaj na procese starenja kod wt i tim01 mušica.
Mjerili smo bihevioralne fenotipove: negativnu geotaksiju, količinu aktivnosti i spavanja, otpornost na strest izgladnjivanja, isušivanja, dužinu životnog vijeka, prosječnu težinu. Ova mjerenja korelirali smo s biokemijskim parametrima: aktivnošću katalaze i superoksid dismutaze, AGE akumulacijom, količinom mono-di-tri glicerida i reduktivnih šećera. Ispitivanja su provedena na oba spola.
Dobiveni rezultati pokazali su da polifenoli imaju pozitivne utjecaje na dužinu života te su isto tako pospješili motoričku sposobnost okomitog penjanja koje starenjem opada. Polifenoli su se također pokazali uspješnim prilikom fizioloških stresova gdje su tretirane mušice u usporedbi s netretiranim duže preživjele bez hrane i vode. Starenjem dolazi do akumulacije AGE produkata koje smo zabilježili u wt mušica dok kod tim mušica nisu uočene. Polifenoli nisu pokazali veća smanjenja u AGE nakupljanju kod wt i tim mušica. Polifenoli su smanjili aktivnost katalaze i kod wt i tim mušica oba spola, dok je njihovo djelovanje na superoksid dismutazu bilo spolno, starosno i genotipno specifično. Polifenoli nisu pokazali značajne utjecaje na količinu aktivnosti i spavanja, prosječnu težinu, ukupnu količinu mono-di-tri glicerida i reduktivnih šećera.
Dobiveni rezultati pokazuju da polifenoli djeluju na mehanizme starenja, ali nije potpuno jasno na koji način. Jedno objašnjenje naših rezultata je da polifenoli
djeluju na smanjivanju razine reaktivnih kisikovih vrsta te tako dovode do smanjenja oksidativnog oštećenja. Ne znamo da li je taj ujecaj direktan (antioksidativna aktivnost polifenola) ili indirektan preko djelovanja na aktivnosti endogenih antioksidativnih enzima. Daljnja istraživanja trebala bi razjasniti interakciju polifenola s cirkadijalnim genima i procesom starenja.
Abstract (english) Light-dark cycle have effects on circadian genes which regulate homeostasis regulation and physical and behavioral changes during 24 hour period. Circadian genes regulate circadian rhythmicity, metabolism and influence mechanisms on aging. Aging is a complex that involves changes in organism: reduction in the function of cells, larger susceptibility for disease and eventually death. One aging theory connects aging with accumulation of oxidative damages, which are usually connected with circadian genes regulation. Process of aging is associated with oxidative stress as a result of reactive oxygen species damaging proteins, lipids and DNA. It has been shown that mutations in circadian period (per) gene can lead to accelerated aging, therefore we tested whether mutation in tim01 gene, dimerisation partner of per gene product, has effects on accelerated aging of Drosophila melanogaster. We tested if addition of polyphenols, quercetin and tyrosol, in the food have effects on aging of wt and tim01 flies.
We measured behavioral phenotypes: negative geotaxis, amount of activity and sleep, resistance to starvation and dehydration stress, longevity and average weight. This measurments were correlated with biochemical measurments: catalase and superoxide dismutase activity, AGE accumulation, mono-di-tri-glycerides and reductive sugars quantity. Tests were conducted on both sexes.
Results showed positive effects of polyphenols on longevity and they improved motor skills of horizontal climbing which normally decreases with aging. Polyphenols also showed positive effect to physiological stress (starvation and dehydration) where treated flies lived longer compared to not treated flies. Accumulation of AGE products were shown in wt flies but not in tim01 flies. Polyphenols did not affect AGE accumulation in wt and tim flies. Polyphenols decreased catalase activity of wt and tim flies of both genders, while their effect on superoxide dismutase were gender, age and genotype specific. Polyphenols showed no significant effects on total amount of activity and sleep, average weight, amount of mono-di-tri-glycerides and reductive sugars.
Results showed that polyphenols have effects on aging mechanism, but it is not yet clear in which way. One explanation of our results is that polyphenols decrease
levels of reactive oxygen species and in that way they decrease oxidative damages. We don't know if that influence is direct (antioxidant activity of polyphenols) or indirect through action on endogenous antioxidant enzymes. Further research should clarify interactions of polyphenols with circadian genes and aging process.
Keywords
cirkadijalni geni
Drosophila melanogaster
starenje
polifenoli
Keywords (english)
circadian genes
Drosophila melanogaster
aging
polyphenols
Language croatian URN:NBN urn:nbn:hr:193:293222 Study programme Title: Drug research and development Type of resource Text File origin Born digital Access conditions Closed access Terms of use Created on 2016-11-18 08:32:30
