Transkriptom leve komore srca pacova sa doksorubicinskom kardiomiopatijom
Left ventricular transcriptome in doxorubicin-induced cardiomyopathy in rats
Докторанд
Pajović, VladislavМентор
Japundžić-Žigon, NinaЧланови комисије
Srebro, DraganaĐukić, Ljiljana
Pavlica-Bajić, Dragana
Метаподаци
Приказ свих података о дисертацијиСажетак
Kardiomiopatija predstavlja najozbiljnije neželjeno dejstvo doksorubicina, citostatika koji ima
široku upotrebu. Nažalost, trenutno ne postoji dovoljno efikasna terapija za kardiomiopatiju
indukovanu doksorubicnom. Cilj ovog istraživanja je potvrda modela doksorubicinske
kardiotoksičnosti, identifikovanje fenotipova i njihovo povezivanje sa ekspresijom gena u srčanom
tkivu. Mužjacima Wistar pacova je ugrađen radiotelemetrijski transmiter, a zatim su nasumično
raspoređeni u eksperimentalnu (5 mg/0,5 mL/kg, I.V. doksorubicin; n=18) i kontrolnu grupu (0,5
mL/kg I.V. fiziološki rastvor; n=6). Ehokardiografsko merenje, procena autonomnih spektralnih
markera i funkcije barorefleksa su rađeni pre tretmana i na samom kraju protokola. Krv je sakupljana
po završetku protokola. Tkiva srca, bubrega i jetre su histološki analizirani posle smrti jedinki.
Ehokardiografski, biohemijski i autonomni parametri su korišćeni za identifikovanje fenotipova
fenomapiranjem metodom mašinskog učenja. Ekspresija ...gena je merena RT-qPCR metodom.
Identifikovana su dva glavna fenotipa kod jedinki koje su razvile doksorubicinsku kardiomiopatiju.
Fenotip 1 karakteriše pad ejekcione frakcije leve komore, dilatacija leve komore, stanjenje zida leve
komore, pad srčane frekvence, povećanje senzitivnosti barorefleksa i NT-proBNP-a. Fenotip 2
karakteriše očuvana ejekciona frakcija leve komore, hipetrofija i povećanje mase leve komore,
očuvane vrednosti srčane frekvence, povećanje senzitivnosti barorefleksa i umereno povećanje NT-
proBNP-a. U obe grupe je primećen pad ekspresije gena za MYH6, odnosa MYH6 i MYH7, APLN,
APLNR, COL1A1, TTN, MYBPC3 i VACM1, odnosno porast ekspresije gena za MYH7 i CTFG.
Ipak, između grupa nije bilo razlike u ekspresiji gena, te nije bilo moguće identifikovanje dva
genotipa.
Cardiomyopathy is the most serious adverse effect of doxorubicin (dox), widely used cytostatic
drug. Unfortunately, at present, there is no efficient treatment for doxorubicin-induced
cardiomyopathy (DCM). The aim of the present work was to affirm the experimental model of DCM
in rats, to distinct phenotypes and associate them to the changes in cardiac transcriptome. Male Wistar
rats equipped with radiotelemetry device, were randomized in DOX group (5 mg/0,5 mL/kg, IV dox;
n=18) and CONT group (0,5 mL/kg IV saline; n=6). Echocardiography, autonomic spectral markers
and baroreceptor reflex evaluation was performed prior to, and after treatment. Blood samples were
collected at the end of experimentation. Cardiac, renal and hepatic tissues were histologically
analysed post-mortem. Echocardiografic, biochemical and cardiovascular autonomic spectral
parameters were used to identified phenotypes by phenomapping, machine learning method. Changes
in expression of cardiac genes affected by dox ...were assessed by RT-qPCR. The results emphasize
the existence of two major phenotypes of DCM with comparably high mortality rates. Phenotype 1
is characterized by reduced left ventricular ejection fraction (LVEF), LV dilatation, thinning of LV
posterior wall, decreased heart rate (HR), increased baroreceptor reflex sensitivity (BRS) and
increased NT-proBNP. Phenotype 2 is characterized by preserved LVEF, LV hypertrophy, increased
LV mass, no changes in HR, increased BRS and moderate NT-proBNP increase. Both phenotypes
exhibited a decreased gene expression for MYH6, MYH6 and MYH7 ratio, APLN, APLNR,
COL1A1, TTN, MYBPC3 and VACM1 and increased gene expression for MYH7 and CTFG.
However, due to no difference in gene expression between those phenotypes, we could not identify
two genotypes.