Določanje relativne dolžine telomer v levkocitih in njen pomen pri dializnih bolnikih

Somi, Simona (author), Ostanek, Barbara (mentor), Pajek, Jernej (comentor)

Telomere so nukleoproteinske strukture, ki ščitijo konce kromosomov in ohranjajo stabilnost genoma. Z vsako celično delitvijo se telomere skrajšajo zaradi problema podvajanja koncev, dokler ne postanejo kritično kratke in izgubijo svojo zaščitno vlogo. Na skrajševanje telomer vpliva še veliko drugih dejavnikov, med katere spadata tudi oksidativni stres in vnetje, ki sta značilna za dializne bolnike. Namen naloge je bil preučiti pomen relativne dolžine telomer v levkocitih pri dializnih bolnikih. S tem namenom smo iz vzorcev polne krvi 82 dializnih bolnikov in 112 zdravih kontrol izolirali DNA in s pomočjo kvantitativne verižne reakcije s polimerazo v realnem času določili relativno dolžino telomer v levkocitih. Dolžino telomer smo primerjali med skupinama dializnih bolnikov in zdravih kontrol, pri dializnih bolnikih pa smo preverili še povezanost relativne dolžine telomer v levkocitih s starostjo, trajanjem dializnega zdravljenja in vnetjem. Med skupinama dializnih bolnikov in zdravih kontrol nam ni uspelo dokazati statistično značilne razlike v relativni dolžini telomer v levkocitih (p = 0,720). Statistično značilne razlike med dializnimi bolniki in zdravimi kontrolami nismo ugotovili niti, kadar smo preiskovance razdelili v pet starostnih skupin (p > 0,05). Pri preverjanju povezanosti relativne dolžine telomer v levkocitih dializnih bolnikov z izbranimi dejavniki smo statistično značilno povezavo našli le s kronološko starostjo (Spearmanov koeficient korelacije = –0,535; p < 0,001), povezanost z vnetjem je bila mejno statistično značilna (Spearmanov koeficient korelacije = –0,207; p = 0,070), povezanost s trajanjem dializnega zdravljenja pa ni bila statistično značilna (Spearmanov koeficient korelacije = –0,132; p > 0,05). Z uporabo modelov multiple linearne regresije smo ugotovili, da na relativno dolžino telomer v levkocitih izmed vseh izbranih spremenljivk statično značilno vpliva samo kronološka starost (p = 0,007; skupina dializnih bolnikov). V naši raziskavi so sodelovali le dializni bolniki, ki se zdravijo s hemodializo, zato bi lahko v nadaljnje raziskave vključili še bolnike na peritonealni dializi in preverili razliko med obema oblikama nadomestnega zdravljenja končne odpovedi ledvic. Ker se dolžina telomer spreminja, bi lahko v prihodnje raziskali še hitrost skrajševanja dolžine telomer v levkocitih dializnih bolnikov.

• Language: Slovenian
• Keywords: relativna dolžina telomer v levkocitih, dializni bolniki, končna odpoved ledvic, kronična ledvična bolezen, kvantitativna verižna reakcija s polimerazo v realnem času
• Work type: Master's thesis/paper
• Organization: FFA - Faculty of Pharmacy
• Year: 2021
• PID: 20.500.12556/RUL-131738
• Publication date in RUL: 02.10.2021

Secondary language

• Language: English
• Title: Measurement of relative leukocyte telomere length and its relevance in dialysis patients

Abstract

Telomeres are nucleoprotein structures that protect the ends of chromosomes and maintain genome stability. With each cell division, telomeres shorten due to the end replication problem, until they become critically short and lose their protective role. Telomere shortening is influenced by many other factors, including oxidative stress and inflammation, which are present in dialysis patients. The aim of our research was to study the relevance of relative leukocyte telomere length in dialysis patients. For this purpose, we isolated the DNA from whole blood samples of 82 dialysis patients and 112 healthy controls, and measured the relative leukocyte telomere length using real-time polymerase chain reaction. We compared the relative leukocyte telomere lengths between dialysis patients and healthy controls, and we examined the association of relative leukocyte telomere length with chronological age, duration of dialysis treatment and inflammation in dialysis patients. We were unable to demonstrate a statistically significant difference in relative leukocyte telomere length between groups of dialysis patients and healthy controls (p = 0,720). There were no statistically significant differences between dialysis patients and healthy controls even when the subjects were divided into five age groups (p > 0,05). When we examined the correlation of relative leukocyte telomere length of dialysis patients with the selected factors, we found a statistically significant association only with chronological age (Spearman’s Correlation Coefficient = –0,535; p < 0,001), the association with inflammation was borderline statistically significant (Spearman’s Correlation Coefficient = –0,207; p = 0,070), and the association with the duration of dialysis treatment was not statistically significant (Spearman’s Correlation Coefficient = –0,132; p > 0,05). Using different linear regression models, we found that only chronological age has a statistically significant effect on relative leukocyte telomere length (p = 0,007; dialysis patients). Only haemodialysis patients were included in our study, so patients on peritoneal dialysis could be included in further studies and the difference between the two forms of renal replacement therapy could be examined. As telomere length varies, the rate of leukocyte telomere length shortening in dialysis patients could be investigated in the future.

• Keywords: relative leukocyte telomere length, dialysis patients, end-stage renal disease, chronic kidney disease, real-time polymerase chain reaction