Ugotavljanje povezanosti lipidnega statusa in polimorfizmov provnetnih genov z dolžino telomerov pri bolnikih s sladkorno boleznijo tipa 2

Plesničar, Tjaša (author), Trebušak Podkrajšek, Katarina (mentor), Klen, Jasna (comentor)

Sladkorna bolezen tipa 2 je metabolična in vnetna bolezen, katere pojavnost v zadnjih letih izrazito narašča. Zanjo je poleg hiperglikemije značilen tudi pojav dislipidemije. Slednja v telesu povečuje vnetno stanje ter oksidativni stres. Na to kako buren bo vnetni odziv, vpliva tudi izražanje provnetnih genov, na katero pa vplivajo genetske spremembe v regulatornih ali kodirajočih področjih genov. Vnetje in oksidativni stres sta dejavnika, ki pospešujeta krajšanje telomerov, kompleksov deoksiribonukleinske kisline in proteinov, ki se nahajajo na koncih kromosomov ter so sestavljeni iz dolgih tandemskih ponovitev deoksiribonukleinske kisline. Njihova vloga je zaščita genoma pred poškodbami. Namen magistrskega dela je bil ugotoviti, ali je lipidni status povezan s pospešenim krajšanjem dolžine telomerov pri bolnikih s sladkorno boleznijo tipa 2 ter ali na dolžino telomerov pri teh bolnikih vpliva genetska variabilnost provnetnih genov IL6, TNF in IL1B. V raziskavo smo vključili 150 bolnikov starih med 41 in 75 let s sladkorno boleznijo tipa 2 ter z zelo veliko srčno žilno ogroženostjo, ki je bila ocenjena glede na smernice Evropskega kardiološkega združenja za preventivo srčno-žilnih bolezni iz leta 2016 ter slovenske prilagoditve iz leta 2012. Bolnikom smo določili, ali imajo povišane/normalne vrednosti celokupnega holesterola, povišane/normalne vrednosti holesterola lipoproteinov nizke gostote ter triacilglicerolov in znižane/normalne vrednosti holesterola lipoproteinov visoke gostote. Za posameznega bolnika smo z modificirano Cawthonovo metodo verižne reakcije s polimerazo v realnem času določili relativne dolžine telomerov ter s kompetitivno alelno specifično verižno reakcijo s polimerazo določili polimorfizme genov IL1B (rs16944), IL6 (rs1800795) in TNF (rs1800629). S statistično analizo podatkov nismo uspeli dokazati povezave med dolžino telomerov ter lipidnim statusom pri bolnikih s sladkorno boleznijo tipa 2. Analizo smo tudi prilagodili na starost, spol, zdravljenje s statini ter trajanje sladkorne bolezni, t. j. dejavniki, ki bi lahko dodatno vplivali na dolžino telomerov, vendar povezave tudi v tem primeru nismo odkrili. Z dolžino telomerov prav tako nismo povezali polimorfizmov provnetnih genov IL6, TNF in IL1B pri omenjenih bolnikih. Povezave ni bilo prisotne tudi po prilagoditvi na starost, spol, zdravljenje s statini ter prisotnost povišanih oz. normalnih vrednosti celokupnega holesterola. Za dokončno pojasnitev zastavljenega raziskovalnega problema bi bile potrebne nadaljnje raziskave, predvsem na večjem številu bolnikov.

• Language: Slovenian
• Keywords: sladkorna bolezen tipa 2, dolžina telomerov, dislipidemija, vnetje, polimorfizmi provnetnih genov
• Work type: Master's thesis/paper
• Organization: FFA - Faculty of Pharmacy
• Year: 2020
• PID: 20.500.12556/RUL-121251
• Publication date in RUL: 02.10.2020

Secondary language

• Language: English
• Title: Evaluation of association between the lipid status and polymorphisms of proinflammatory genes, and telomere length in type 2 diabetic patients

Abstract

Type 2 diabetes is an inflammatory and metabolic disease, with significant increase in incidence over the past years. Besides hyperglycemia, type 2 diabetes is also characterised with dyslipidemia, which increases inflammatory state and oxidative stress of the body. Inflammatory response is dependent on expression of proinflammatory genes, while their expression is influenced by genetic changes in regulatory and coding parts of genes. Inflammation and oxidative stress are two factors, associated with accelerated shortening of telomeres. Telomeres are deoxyribonucleic acid–protein complexes located at the end of chromosomes with typical long tandem repeats of deoxyribonucleic acid. Their primal role is protection of the genome from deoxyribonucleic acid damage. The goal of this master’s thesis was evaluation of the association of lipid state and accelerated shortening of telomere length of type 2 diabetes patients and evaluation of association of telomere length and genetic variability of inflammatory genes IL6, TNF, IL1B in these patients. We included 150 patients aged between 41 and 75 with type 2 diabetes and very high cardiovascular risk, as evaluated according to the 2016 European Society of Cardiology Guidelines on cardiovascular disease prevention and 2012 Slovenian adjustments. We determined, whether patients have elevated/normal levels of total cholesterol, elevated/normal levels of low-density lipoprotein cholesterol and triacylglycerols or decreased/normal levels of high-density lipoprotein cholesterol. For each patient, we had used modified Cawthon real-time polymerase chain reaction method to determine relative telomere length and competitive specific allele polymerase chain reaction, to determine gene polymorphism variants IL1B (rs16944), IL6 (rs1800795) and TNF (rs1800629). Using statistical analysis, we could not have proven the association between telomere length and lipid state of type 2 diabetes patients. We have adjusted the analysis regarding age, sex, statin treatment and the duration of diabetes, e.g. factors, that could additionally influence telomere length, but found no association. In our cohort of patients, the telomere length was not associated with polymorphisms of inflammatory genes IL6, TNF and IL1B. There was no association even after adjustment of age, sex, statin treatment and having elevated/normal values of total cholesterol. To get final elucidation of the scientific questions posted in this study, further research is required, preferably on larger group of patients.

• Keywords: type 2 diabetes, telomere length, dyslipidemia, inflammation, polymorphisms of proinflammatory genes