All anthracyclines, including doxorubicin (DOXO), the most common and still indispensable drug, exhibit cardiotoxicity with inherent risk of irreversible cardiomyopathy leading to heart failure with reduced ejection fraction (HFrEF). Current pharmacological strategies are clearly less effective for this type of HFrEF, hence an urgent need for new therapeutic approaches. The prerequisite for success is thorough understanding of pathophysiology of this HFrEF form, which requires an appropriate animal model of the disease. The aim of this study was to comprehensively characterise a novel model of HF with cardiorenal syndrome, i.e. DOXO-induced HFrEF with nephrotic syndrome, in which DOXO was administered to Ren-2 transgenic rats (TGR) via five intravenous injections in a cumulative dose of 10 mg/kg of body weight (BW). Our analysis included survival, echocardiography, as well as histological examination of the heart and kidneys, blood pressure, but also a broad spectrum of biomarkers to evaluate cardiac remodelling, fibrosis, apoptosis, oxidative stress and more. We have shown that the new model adequately mimics the cardiac remodelling described as "eccentric chamber atrophy" and myocardial damage typical for DOXO-related cardiotoxicity, without major damage of the peritoneum, lungs and liver. This pattern corresponds well to a clinical situation of cancer patients receiving anthracyclines, where HF develops with some delay after the anticancer therapy. Therefore, this study may serve as a comprehensive reference for all types of research on DOXO-related cardiotoxicity, proving especially useful in the search for new therapeutic strategies.
- MeSH
- antibiotika antitumorózní škodlivé účinky MeSH
- doxorubicin * škodlivé účinky MeSH
- krysa rodu rattus MeSH
- ledviny účinky léků patofyziologie MeSH
- modely nemocí na zvířatech * MeSH
- nefrotický syndrom * chemicky indukované farmakoterapie patofyziologie MeSH
- oxidační stres účinky léků MeSH
- potkani transgenní * MeSH
- srdeční selhání * chemicky indukované patofyziologie MeSH
- tepový objem * účinky léků MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Publikační typ
- abstrakt z konference MeSH
Anthracyclines, such as doxorubicin (adriamycin), daunorubicin, or epirubicin, rank among the most effective agents in classical anticancer chemotherapy. However, cardiotoxicity remains the main limitation of their clinical use. Topoisomerase IIβ has recently been identified as a plausible target of anthracyclines in cardiomyocytes. We examined the putative topoisomerase IIβ selective agent XK469 as a potential cardioprotective and designed several new analogs. In our experiments, XK469 inhibited both topoisomerase isoforms (α and β) and did not induce topoisomerase II covalent complexes in isolated cardiomyocytes and HL-60, but induced proteasomal degradation of topoisomerase II in these cell types. The cardioprotective potential of XK469 was studied on rat neonatal cardiomyocytes, where dexrazoxane (ICRF-187), the only clinically approved cardioprotective, was effective. Initially, XK469 prevented daunorubicin-induced toxicity and p53 phosphorylation in cardiomyocytes. However, it only partially prevented the phosphorylation of H2AX and did not affect DNA damage measured by Comet Assay. It also did not compromise the daunorubicin antiproliferative effect in HL-60 leukemic cells. When administered to rabbits to evaluate its cardioprotective potential in vivo, XK469 failed to prevent the daunorubicin-induced cardiac toxicity in either acute or chronic settings. In the following in vitro analysis, we found that prolonged and continuous exposure of rat neonatal cardiomyocytes to XK469 led to significant toxicity. In conclusion, this study provides important evidence on the effects of XK469 and its combination with daunorubicin in clinically relevant doses in cardiomyocytes. Despite its promising characteristics, long-term treatments and in vivo experiments have not confirmed its cardioprotective potential.
- MeSH
- antibiotika antitumorózní toxicita MeSH
- antracykliny * toxicita terapeutické užití MeSH
- chinoxaliny * MeSH
- daunomycin toxicita terapeutické užití MeSH
- DNA-topoisomerasy typu II metabolismus terapeutické užití MeSH
- doxorubicin toxicita MeSH
- inhibitory topoisomerasy II * toxicita terapeutické užití MeSH
- kardiotoxicita MeSH
- králíci MeSH
- krysa rodu rattus MeSH
- poškození DNA MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Background: Anthracycline cardiotoxicity is a well-known complication of cancer treatment, and miRNAs have emerged as a key driver in the pathogenesis of cardiovascular diseases. This study aimed to investigate the expression of miRNAs in the myocardium in early and late stages of chronic anthracycline induced cardiotoxicity to determine whether this expression is associated with the severity of cardiac damage. Method: Cardiotoxicity was induced in rabbits via daunorubicin administration (daunorubicin, 3 mg/kg/week; for five and 10 weeks), while the control group received saline solution. Myocardial miRNA expression was first screened using TaqMan Advanced miRNA microfluidic card assays, after which 32 miRNAs were selected for targeted analysis using qRT-PCR. Results: The first subclinical signs of cardiotoxicity (significant increase in plasma cardiac troponin T) were observed after 5 weeks of daunorubicin treatment. At this time point, 10 miRNAs (including members of the miRNA-34 and 21 families) showed significant upregulation relative to the control group, with the most intense change observed for miRNA-1298-5p (29-fold change, p < 0.01). After 10 weeks of daunorubicin treatment, when a further rise in cTnT was accompanied by significant left ventricle systolic dysfunction, only miR-504-5p was significantly (p < 0.01) downregulated, whereas 10 miRNAs were significantly upregulated relative to the control group; at this time-point, the most intense change was observed for miR-34a-5p (76-fold change). Strong correlations were found between the expression of multiple miRNAs (including miR-34 and mir-21 family and miR-1298-5p) and quantitative indices of toxic damage in both the early and late phases of cardiotoxicity development. Furthermore, plasma levels of miR-34a-5p were strongly correlated with the myocardial expression of this miRNA. Conclusion: To the best of our knowledge, this is the first study that describes alterations in miRNA expression in the myocardium during the transition from subclinical, ANT-induced cardiotoxicity to an overt cardiotoxic phenotype; we also revealed how these changes in miRNA expression are strongly correlated with quantitative markers of cardiotoxicity.
- Publikační typ
- časopisecké články MeSH
Tinnitus je popisován jako nepříjemný sluchový vjem bez externího zdroje zvuku, jedná se o příznak, nikoliv samostatnou diagnózu. Jedná se o relativně častý příznak a udává se, že až 10 % světové populace trpí chronickým tinnitem, v České republice je s tímto příznakem sledováno zhruba 700 000 pacientů. Mezi příčiny tinnitu řadíme mechanické poškození sluchového aparátu, infekce, neurologická, metabolická a psychiatrická onemocnění, hypertenzi a mnoho dalších. Právě hypertenze bývá zejména u dětí hlavně sekundární etiologie a je nutné pátrat po její příčině. Jednou z nich může být i sekretoricky aktivní tumor produkující katecholaminy, jakým je paragangliom nebo feochromocytom. U těchto vzácných typů nádorů je nutné molekulárně genetické vyšetření k vyloučení genetické predispozice, která by pro pacienta znamenala celoživotní sledování.
Tinnitus is described as an unpleasant auditory sensation without an external source, it is a symptom, not a clinical diagnosis. It is a relatively common symptom and it is reported that up to 10% of the world's population suffers from chronic tinnitus, in the Czech Republic about 700,000 patients are complaining of tinnitus. The causes of tinnitus include mechanical damage to the hearing system, infections, neurological, metabolic and psychiatric diseases, hypertension and many others. Etiology of hypertension is especially in children mainly secondary and it is necessary to search for its underlying cause. One of them may be a secretory active tumour producing catecholamines such as paraganglioma or pheochromocytoma. In these rare types of tumours, molecular genetic testing is necessary to rule out a genetic predisposition syndrome that would require lifelong follow-up for the patient.
- MeSH
- anamnéza MeSH
- genetická predispozice k nemoci MeSH
- hypertenze etiologie MeSH
- karcinom z renálních buněk * diagnostické zobrazování genetika komplikace MeSH
- lidé MeSH
- mladiství MeSH
- paragangliom * diagnostické zobrazování genetika komplikace MeSH
- rodokmen MeSH
- tinnitus etiologie MeSH
- zárodečné mutace MeSH
- Check Tag
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
This was a prospective cohort study of eighteen patients with large and debilitating vascular malformations with one or more major systemic complications. In all patients, we discovered activating alterations in either TEK or PIK3CA. Based on these findings, targeted treatment using the PI3K inhibitor alpelisib was started with regular check-ups, therapy duration varied from 6 to 31 months. In all patients, marked improvement in quality of life was observed. We observed radiological improvement in fourteen patients (two of them being on combination with either propranolol or sirolimus), stable disease in 2 patients. For 2 patients, an MRI scan was not available as they were shortly on treatment, however, a clinically visible response in size reduction or structure regression, together with pain relief was observed. In patients with elevated D-dimer levels before alpelisib administration, a major improvement was noted, suggesting its biomarker role. We observed overall very good tolerance of the treatment, documenting a single patient with grade 3 hyperglycemia. Patients with size reduction were offered local therapies wherever possible. Our report presents a promising approach for the treatment of VMs harboring different targetable TEK and PIK3CA gene mutations with a low toxicity profile and high efficacy.
- Publikační typ
- abstrakt z konference MeSH
