Vpliv dodatnih nevroloških motenj na kocentracijo modificiranih nukleozidov v urinu otrok z motnjami avtističnega spektra

Celjer, Valentina (avtor), Osredkar, Joško (mentor)

Motnje avtističnega spektra (MAS) uvrščamo med pervazivne motnje v nevrološkem razvoju. Gre za motnje z zelo širokim spektrom kliničnih značilnosti, ki se začnejo kazati že v zgodnjih letih razvoja, in sicer pri 1–2 % otrok. Najpogostejše in najizrazitejše značilnosti so omejena zmožnost socialnega komuniciranja, verbalne in neverbalne interakcije ter razvijanje medsebojnih odnosov. Zaradi kompleksnosti motnje še ni veljavnega zanesljivega testa, s katerim bi lahko diagnosticirali bolezen. Trenutno se v ta namen uporablja diagnostični algoritem, ki združuje psihološke in klinične ocene specifičnih lastnosti. Glavna aktualna etiološka teorija temelji na kompleksni kombinaciji in interakciji genetskih in epigenetskih sprememb, kjer se kot dejavniki tveganja in vzroki za razvoj bolezni prepletajo genetski, epigenetski in okoljski dejavniki. V povezavi z boleznijo so bile dokazane tudi spremembe delovanja imunskega sistema, mitohondrijev, metilacijskih mehanizmov, metabolizma aminokislin in oksidativnega stresa. Na osnovi teh spoznanj o spremembah določenih biokemijskih poti je bilo objavljenih več izsledkov raziskav o odkrivanju ustreznih bioloških označevalcev, s katerimi bi lahko diagnosticirali bolnike z MAS. Razvoj je bil usmerjen v odkrivanje specifičnih genetskih sprememb in določanje koncentracij specifičnih analitov, vključenih v kritične biokemijske poti. V nalogi smo se na podlagi dosedanjih raziskav odločili preveriti možnost uporabe določenih modificiranih nukleozidov kot bioloških označevalcev MAS. Zanje je bilo dokazano, da naj bi se njihova koncentracija spreminjala ob prisotnosti določenih patoloških procesov v telesu. Izbrali smo 6 analitov, O-metilgvanozin, 3-metiladenin, 1-metilgvanin, 1-metiladenozin, 7-metilgvanin in 8-hidroksi-2'deoksigvanozin, ki naj bi bili glavni fiziološki katabolni produkti človeškega metabolizma purinov in pirimidinov. Koncentracije analitov so bile določene iz urinskega vzorca z metodo tekočinske kromatografije visoke ločljivosti, sklopljene z masno spektrometrijo. Rezultate smo primerjali glede na s kontrolno skupino in glede na težo postavljene diagnoze ter prisotnost dodatnih diagnoz nevrološkega izvora. Z analizo zbranih podatkov smo potrdili nekatera stalna in značilna odstopanja v koncentracijah analitov pri preiskovancih z MAS glede na kontrolno skupino. Ugotovili smo tudi, da se tako s težo kot tudi številom oz. prisotnostjo dodatnih diagnoz odstopanja od kontrolne skupine povečujejo. Dokazali smo statistično značilno razliko v koncentracijah analitov med kontrolno skupino in vsako izmed primerjanih skupin, torej skupino preiskovancev z MAS, skupino z MAS in dodatnimi diagnozami nevrološkega izvora, skupinama z blago in zmerno obliko MAS ter skupino z MAS in dodatno diagnozo duševne manjrazvitosti. Na drugi strani pa kljub opaženim razlikam v koncentracijah analitov nismo mogli dokazati statistično značilne razlike med skupino preiskovancev, ki imajo le MAS, in skupino z MAS in dodatnimi diagnozami nevrološkega izvora. Glede na izsledke raziskave bi bilo v prihodnje smiselno vpeljati nukleozidne biološke označevalce v diagnostični algoritem MAS.

• Jezik: Slovenski jezik
• Ključne besede: Motnje avtističnega spektra, metilacija, nukleozidi, biološki označevalci, krivulje ROC
• Vrsta gradiva: Magistrsko delo/naloga
• Organizacija: FFA - Fakulteta za farmacijo
• Leto izida: 2021
• PID: 20.500.12556/RUL-131608
• Datum objave v RUL: 30.09.2021

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: The influence of additional diagnoses of neurological disorders on the concentrations of modified nucleosides in the urine of children with autism spectrum disorder

Izvleček

Autism spectrum disorder is classified as a pervasive neurodevelopmental disorder. It refers to a group of complex disorders with a very wide range of clinical features, which in 1-2% of children begin to be expressed in the early years of development. The most common and most pronounced characteristics are limited social communication, difficulties with verbal and nonverbal interactions as well as poor ability to develop interpersonal relationships. Due to the complexity of the disorder, a definitive clinical test to diagnose the disease has not been developed. Currently, a diagnostic algorithm that involves a combination of psychological and clinical assessments of specific traits is used. The main current etiological theory is based on a complex combination and interaction of genetic and epigenetic changes, where genetic, epigenetic and environmental factors are intertwined as risk factors and causes of disease development. Changes in the functioning of the immune system, mitochondria, methylation mechanisms, amino acid metabolism and oxidative stress have also been confirmed in association with the disease. Based on the findings of changes in certain biochemical pathways, studies have begun to identify appropriate biological markers that could be used to diagnose patients with autism spectrum disorder. Development is taking place in the direction of detecting specific genetic changes, as well as determining the concentrations of specific analytes involved in critical biochemical pathways. Based on previous research, we decided to examine the possibility of using certain methylated nucleosides as biological markers of autism spectrum disorder. They have been proven to change their concentration in the presence of certain pathological processes in the body. Since they are said to represent the major physiological catabolic products of human purine and pyrimidine metabolism, six analytes have been selected, namely, O-methylguanosine, 3-methyladenine, 1-methylguanine, 1-methyladenosine, 7-methylguanine and 8-hydroxy-2'-deoxyguanosine. Analyte concentrations were determined from a urine sample by high performance liquid chromatography coupled by mass spectrometry. The results were compared with the control group and also according to the severity of the diagnosis and the presence of additional diagnoses of neurological origin. The analysis of the collected data confirmed that in patients with autism spectrum disorders there are some constant and characteristic deviations in analyte concentrations according to the control group. What is more, deviations from the control group increase with weight, as well as the presence of additional diagnoses. Based on the results, it would therefore make sense to continue the development of the diagnostic methods by introducing nucleoside biomarkers into the diagnostic algorithm of autism spectrum disorder.

• Ključne besede: Autism spectrum disorder, methylation, nucleosides, biomarkers, ROC curves