Oksidacijski i antioksidacijski status i ekspresija sirtuina nakon ronjenja s komprimiranim zrakom

doctoral thesis

• Title (english): Effect of scuba diving on the oxidant/antioxidant status and sirtuins expression
• Author: Antonija Perović
• Mentor: Jerka Dumić (mentor)
• Mentor: Sandra Sobočanec (komentor)
• Committee member: Tihana Žanić-Grubišić (predsjednik povjerenstva)
• Committee member: Tihomir Balog (član povjerenstva)
• Committee member: Danica Galešić-Ljubanović (član povjerenstva)
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of biochemistry and molecular biology); Zagreb
• Defense date and country: 2018-07-24, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Medical Biochemistry
• Universal decimal classification (UDC): 615 - Pharmacology. Therapeutics. Toxicology

Abstract

Ronjenje s komprimiranim zrakom predstavlja poseban oblik oksidacijskog stresa izazvanog vježbanjem jer je
poveano stvaranje reaktivnih kisikovih spojeva (ROS) posljedica ne samo zahtjevne fizike aktivnosti, ve i
hiperoksije, koja nastaje uslijed disanja kisika pod povišenim tlakom. Smatra se da bi uinkovitost
antioksidacijskih enzima mogla ovisiti o aktivnosti sirtuina (SIRT), molekula osjetljivih na poveanu produkciju
ROS-a, koje imaju sposobnost poveati ekspresiju i aktivnost antioksidacijskih enzima. Cilj je ovog rada bio
ispitati oksidacijski/antioksidacijski status i ekspresiju gena SIRT1 i SIRT3 nakon zarona s komprimiranim
zrakom kod rekreacijskih ronilaca koji nisu ronili tijekom zimskog razdoblja.
U istraživanje je bilo ukljueno 17 ronilaca, muškog spola, raspona životne dobi od 30 do 52 godine. Uzimanje
krvi bilo je provedeno neposredno prije i nakon ronjenja na 30 metara dubine u trajanju od 30 minuta te 3 i 6 sati
nakon ronjenja. U uzorcima krvi odreeni su parametri kompletne krvne slike, u eritrocitima i plazmi praeni su
biljezi oksidacijskog ošteenja lipida i proteina, mjerenjem koncentracije tiobarbiturnih reaktivnih supstanci
(TBARS) i proteinskih karbonila, dok su aktivnosti antioksidacijskih enzima katalaze (CAT), ukupne superoksid
dismutaze (SOD) te izoformi SOD1 i SOD2, kao i ekspresija gena CAT, SOD1 i SOD2 te SIRT1 i SIRT3 bili
praeni u mononuklearnim stanicama krvi.
Rezultati ovog rada pokazali su da poveanje broja leukocita te smanjenje broja eritrocita, hemoglobina i
hematokrita nakon ronjenja nisu kliniki znaajne promjene. Zapažen porast aktivnosti CAT, SOD2 i SOD
neposredno nakon ronjenja nije bio dovoljan da sprijei porast eritrocitnih TBARS vrijednosti. Budui da
promjene TBARS vrijednosti u plazmi, kao ni promjene proteinskih karbonila u plazmi i eritrocitima nisu
naene nakon ronjenja, lipidna peroksidacija u eritrocitima pokazala se najosjetljivijim ispitivanim parametrom
oksidacijskog stresa. Poveanje aktivnosti ispitivanih antioksidacijskih enzima nije bilo praeno porastom
njihove genske ekspresije. Smanjenje ekspresije gena SIRT1 izazvano zaronom, doseglo je bazalnu vrijednost 6
sati nakon ronjenja, kada je uoen porast ekspresije gena SIRT3.
Ovo je istraživanje pokazalo da zaron na 30 metara dubine, nakon razdoblja ne ronjenja, uzrokuje oksidacijsko
ošteenje dajui dobru osnovu za daljnja usmjerena istraživanja u podruju rekreacijskog ronjenja koja bi mogla
biti korisna u formiranju smjernica za rekreacijske ronioce. Uz to, opažen porast ekspresije gena SIRT3 pridonosi
razumijevanju pretpostavljenog adaptacijskog antioksidacijskog mehanizma i hormeznog odgovora na poveanu
produkciju ROS-a.

Abstract (english)

SCUBA diving represents a special form of exercise-induced oxidative stress since the increased production of
reactive oxygen species (ROS) is a result not only of a demanding physical activity, but also of hyperoxia, which
occurs due to breathing oxygen under increased pressure. It is believed that the effectiveness of antioxidant
defense enzymes could be dependent on the activity of sirtuins (SIRT), molecules sensitive to the increased
production of ROS, which have the ability to increase the expression and activation of antioxidant enzymes. The
aim of this study was to examine the effects of scuba diving on oxidative/antioxidative status, as well as SIRT1
and SIRT3 gene expressions in recreational divers after a winter non-dive period.
The study included 17 male recreational divers median age (range) 41 (30-52) years. Blood samples were taken
before and immediately after diving at a depth of 30 m for 30 min, 3 h and 6 h after diving. The changes of the
following parameters were examined: complete blood counts, oxidative damage markers of lipids and proteins in
erythrocytes and plasma, by measuring the formation of thiobarbituric reactive substances (TBARS) and protein
carbonyl derivatives (PCD), while the activities of antioxidant enzymes; catalase (CAT), total superoxide
dismutase (SOD), and isoforms SOD1 and SOD2, as well as CAT, SOD1, SOD2, SIRT1 and SIRT3 gene
expression were monitored in peripheral blood mononuclear cells (PBMCs).
The increase of leukocyte count and the decrease of erythrocyte count, hemoglobin and hematocrit observed
after diving did not show clinical significance. The elevation of CAT, SOD2 and SOD activities observed after
diving was not sufficient to prevent the increase in erythrocyte TBARS values. Since we found no difference for
plasma TBARS level and also for carbonylated proteins level in either plasma or erythrocytes, peroxidative
damage in erythrocytes appears to be the most pronounced response to oxidative stress. Elevation of the
antioxidant enzymes activities was not accompanied by the increase of their gene expression. The decrease of
SIRT1 gene expression induced by diving, reached its basal level 6 h after the dive, when the increase of SIRT3
gene expression was observed.
This study showed that the first dive to 30 m after a non-dive season causes oxidative damage, providing a good
basis for further research in the field of recreational diving, which could be useful for forming the diving
recommendations. In addition, the observed increase of SIRT3 gene expression contributes to the understanding
of the assumed adaptation antioxidant mechanism and the hormesis response to increased ROS production.

• Keywords: ronjenje; hiperoksija; oksidacijski stres; sirtuin 1; sirtuin 3
• Keywords (english): diving; hyperoxia; oxidative stress; sirtuin 1; sirtuin 3
• Language: croatian
• URN:NBN: urn:nbn:hr:163:794420
• Study programme: Title: Pharmacy and biochemistry; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor znanosti (doktor znanosti)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2019-04-08 07:12:10