Mutations of the TMEM70 gene disrupt the biogenesis of the ATP synthase and represent the most frequent cause of autosomal recessive encephalo-cardio-myopathy with neonatal onset. Patient tissues show isolated defects in the ATP synthase, leading to the impaired mitochondrial synthesis of ATP and insufficient energy provision. In the current study, we tested the efficiency of gene complementation by using a transgenic rescue approach in spontaneously hypertensive rats with the targeted Tmem70 gene (SHR-Tmem70ko/ko), which leads to embryonic lethality. We generated SHR-Tmem70ko/ko knockout rats expressing the Tmem70 wild-type transgene (SHR-Tmem70ko/ko,tg/tg) under the control of the EF-1α universal promoter. Transgenic rescue resulted in viable animals that showed the variable expression of the Tmem70 transgene across the range of tissues and only minor differences in terms of the growth parameters. The TMEM70 protein was restored to 16-49% of the controls in the liver and heart, which was sufficient for the full biochemical complementation of ATP synthase biogenesis as well as for mitochondrial energetic function in the liver. In the heart, we observed partial biochemical complementation, especially in SHR-Tmem70ko/ko,tg/0 hemizygotes. As a result, this led to a minor impairment in left ventricle function. Overall, the transgenic rescue of Tmem70 in SHR-Tmem70ko/ko knockout rats resulted in the efficient complementation of ATP synthase deficiency and thus in the successful genetic treatment of an otherwise fatal mitochondrial disorder.

• Klíčová slova
• ATP synthase deficiency, TMEM70 factor, gene therapy, mitochondria disease, transgenic rescue,
• Publikační typ
• časopisecké články MeSH

Hypertension, dyslipidemia, and insulin resistance in the spontaneously hypertensive rat (SHR) can be alleviated by rescuing CD36 fatty acid translocase. The present study investigated whether transgenic rescue of CD36 in SHR could affect mitochondrial function and activity of selected metabolic enzymes in the heart. These analyses were conducted on ventricular preparations derived from SHR and from transgenic strain SHR-Cd36 that expresses a functional wild-type CD36. Our respirometric measurements revealed that mitochondria isolated from the left ventricles exhibited two times higher respiratory activity than those isolated from the right ventricles. Whereas, we did not observe any significant changes in functioning of the mitochondrial respiratory system between both rat strains, enzyme activities of total hexokinase, and both mitochondrial and total malate dehydrogenase were markedly decreased in the left ventricles of transgenic rats, compared to SHR. We also detected downregulated expression of the succinate dehydrogenase subunit SdhB (complex II) and 70 kDa peroxisomal membrane protein in the left ventricles of SHR-Cd36. These data indicate that CD36 may affect in a unique fashion metabolic substrate flexibility of the left and right ventricles.

• Klíčová slova
• CD36, Heart, Left and right ventricles, Mitochondria, OXPHOS, SHR,
• MeSH
• ABC transportéry genetika   metabolismus   MeSH
• antigeny CD36 genetika   metabolismus   MeSH
• exprese genu MeSH
• hexokinasa genetika   metabolismus   MeSH
• hypertenze enzymologie   genetika   patofyziologie   MeSH
• inzulinová rezistence MeSH
• kardiomyocyty enzymologie   patologie   MeSH
• krysa rodu Rattus MeSH
• malátdehydrogenasa genetika   metabolismus   MeSH
• mitochondrie enzymologie   patologie   MeSH
• oxidativní fosforylace MeSH
• potkani inbrední SHR MeSH
• potkani transgenní MeSH
• primární buněčná kultura MeSH
• regulace genové exprese MeSH
• spotřeba kyslíku genetika   MeSH
• srdeční komory enzymologie   patologie   MeSH
• sukcinátdehydrogenasa genetika   metabolismus   MeSH
• transgeny * MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• ABC transportéry MeSH
• Abcd3 protein, rat MeSH Prohlížeč
• antigeny CD36 MeSH
• hexokinasa MeSH
• malátdehydrogenasa MeSH
• sukcinátdehydrogenasa MeSH

The β-adrenergic signaling pathways and antioxidant defence mechanisms play important roles in maintaining proper heart function. Here, we examined the effect of chronic normobaric hypoxia (CNH, 10% O2, 3 weeks) on myocardial β-adrenergic signaling and selected components of the antioxidant system in spontaneously hypertensive rats (SHR) and in a conplastic SHR-mtBN strain characterized by the selective replacement of the mitochondrial genome of SHR with that of the more ischemia-resistant Brown Norway strain. Our investigations revealed some intriguing differences between the two strains at the level of β-adrenergic receptors (β-ARs), activity of adenylyl cyclase (AC) and monoamine oxidase A (MAO-A), as well as distinct changes after CNH exposure. The β2-AR/β1-AR ratio was significantly higher in SHR-mtBN than in SHR, apparently due to increased expression of β2-ARs. Adaptation to hypoxia elevated β2-ARs in SHR and decreased the total number of β-ARs in SHR-mtBN. In parallel, the ability of isoprenaline to stimulate AC activity was found to be higher in SHR-mtBN than that in SHR. Interestingly, the activity of MAO-A was notably lower in SHR-mtBN than in SHR, and it was markedly elevated in both strains after exposure to hypoxia. In addition to that, CNH markedly enhanced the expression of catalase and aldehyde dehydrogenase-2 in both strains, and decreased the expression of Cu/Zn superoxide dismutase in SHR. Adaptation to CNH intensified oxidative stress to a similar extent in both strains and elevated the IL-10/TNF-α ratio in SHR-mtBN only. These data indicate that alterations in the mitochondrial genome can result in peculiar changes in myocardial β-adrenergic signaling, MAO-A activity and antioxidant defence and may, thus, affect the adaptive responses to hypoxia.

• Klíčová slova
• Adenylyl cyclase, Antioxidant defence, Chronic hypoxia, Mitochondrial genome, Monoamine oxidase A, Myocardium, SHR, β-adrenergic receptors,
• MeSH
• adenylátcyklasy metabolismus   MeSH
• beta-adrenergní receptory metabolismus   MeSH
• hypoxie metabolismus   MeSH
• krysa rodu Rattus MeSH
• malondialdehyd metabolismus   MeSH
• monoaminoxidasa metabolismus   MeSH
• myokard metabolismus   MeSH
• potkani inbrední SHR MeSH
• signální transdukce fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adenylátcyklasy MeSH
• beta-adrenergní receptory MeSH
• malondialdehyd MeSH
• monoaminoxidasa MeSH

We previously mapped hypertension-related insulin resistance quantitative trait loci (QTLs) to rat chromosomes 4, 12 and 16 using adipocytes from F2 crosses between spontaneously hypertensive (SHR) and Wistar Kyoto (WKY) rats, and subsequently identified Cd36 as the gene underlying the chromosome 4 locus. The identity of the chromosome 12 and 16 genes remains unknown. To identify whole-body phenotypes associated with the chromosome 12 and 16 linkage regions, we generated and characterised new congenic strains, with WKY donor segments introgressed onto an SHR genetic background, for the chromosome 12 and 16 linkage regions. We found a >50% increase in insulin sensitivity in both the chromosome 12 and 16 strains. Blood pressure and left ventricular mass were reduced in the two congenic strains consistent with the congenic segments harbouring SHR genes for insulin resistance, hypertension and cardiac hypertrophy. Integrated genomic analysis, using physiological and whole-genome sequence data across 42 rat strains, identified variants within the congenic regions in Upk3bl, RGD1565131 and AABR06087018.1 that were associated with blood pressure, cardiac mass and insulin sensitivity. Quantitative trait transcript analysis across 29 recombinant inbred strains showed correlation between expression of Hspb1, Zkscan5 and Pdgfrl with adipocyte volume, systolic blood pressure and cardiac mass, respectively. Comparative genome analysis showed a marked enrichment of orthologues for human GWAS-associated genes for insulin resistance within the syntenic regions of both the chromosome 12 and 16 congenic intervals. Our study defines whole-body phenotypes associated with the SHR chromosome 12 and 16 insulin-resistance QTLs, identifies candidate genes for these SHR QTLs and finds human orthologues of rat genes in these regions that associate with related human traits. Further study of these genes in the congenic strains will lead to robust identification of the underlying genes and cellular mechanisms.

• Klíčová slova
• Congenic, Genomic, Hypertension, Insulin resistance, Rat,
• MeSH
• celogenomová asociační studie MeSH
• energetický metabolismus genetika   MeSH
• genomika * MeSH
• homeostáza MeSH
• hypertenze genetika   patofyziologie   MeSH
• inzulin farmakologie   MeSH
• inzulinová rezistence genetika   MeSH
• játra účinky léků   metabolismus   MeSH
• jednonukleotidový polymorfismus genetika   MeSH
• kalorimetrie MeSH
• kardiomegalie genetika   patofyziologie   MeSH
• kosterní svaly účinky léků   metabolismus   MeSH
• krevní tlak účinky léků   MeSH
• lidé MeSH
• lokus kvantitativního znaku genetika   MeSH
• potkani inbrední SHR MeSH
• regulace genové exprese účinky léků   MeSH
• savčí chromozomy genetika   MeSH
• srdeční komory účinky léků   patologie   MeSH
• stravovací zvyklosti účinky léků   MeSH
• tělesná hmotnost účinky léků   MeSH
• triglyceridy metabolismus   MeSH
• velikost orgánu účinky léků   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• inzulin MeSH
• triglyceridy MeSH

Dysfunction or abnormalities in the regulation of fatty acid translocase Cd36, a multifunctional membrane protein participating in uptake of long-chain fatty acids, has been linked to the development of heart diseases both in animals and humans. We have previously shown that the Cd36 transgenic spontaneously hypertensive rat (SHR-Cd36), with a wild type Cd36, has higher susceptibility to ischemic ventricular arrhythmias when compared to spontaneously hypertensive rat (SHR) carrying a mutant Cd36 gene, which may have been related to increased β-adrenergic responsiveness of these animals (Neckar et al., 2012 Physiol. Genomics 44:173-182). The present study aimed to determine whether the insertion of the wild type Cd36 into SHR would affect the function of myocardial G protein-regulated adenylyl cyclase (AC) signaling. β-Adrenergic receptors (β-ARs) were characterized by radioligand-binding experiments and the expression of selected G protein subunits, AC, and protein kinase A (PKA) was determined by RT-PCR and Western blot analyses. There was no significant difference in the amount of trimeric G proteins, but the number of β-ARs was higher (by about 35 %) in myocardial preparations from SHR-Cd36 as compared to SHR. Besides that, transgenic rats expressed increased amount (by about 20 %) of the dominant myocardial isoforms AC5/6 and contained higher levels of both nonphosphorylated (by 11 %) and phosphorylated (by 45 %) PKA. Differently stimulated AC activity in SHR-Cd36 significantly exceeded (by about 18-30 %) the enzyme activity in SHR. Changes at the molecular level were reflected by higher contractile responses to stimulation by the adrenergic agonist dobutamine. In summary, it can be concluded that the increased susceptibility to ischemic arrhythmias of SHR-Cd36 is attributable to upregulation of some components of the β-AR signaling pathway, which leads to enhanced sensitization of AC and increased cardiac adrenergic responsiveness.

• MeSH
• adenylátcyklasy genetika   metabolismus   MeSH
• agonisté beta-1-adrenergních receptorů farmakologie   MeSH
• antigeny CD36 genetika   metabolismus   MeSH
• beta-adrenergní receptory metabolismus   MeSH
• dobutamin farmakologie   MeSH
• kontrakce myokardu MeSH
• krysa rodu Rattus MeSH
• myokard metabolismus   MeSH
• potkani inbrední SHR MeSH
• potkani transgenní MeSH
• proteinkinasy závislé na cyklickém AMP metabolismus   MeSH
• proteiny vázající GTP metabolismus   MeSH
• signální transdukce * MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adenylátcyklasy MeSH
• agonisté beta-1-adrenergních receptorů MeSH
• antigeny CD36 MeSH
• beta-adrenergní receptory MeSH
• dobutamin MeSH
• proteinkinasy závislé na cyklickém AMP MeSH
• proteiny vázající GTP MeSH

The present study was undertaken to evaluate the effects of chronic treatment with c-AUCB {cis-4-[4-(3-adamantan-1-ylureido)cyclohexyl-oxy]benzoic acid}, a novel inhibitor of sEH (soluble epoxide hydrolase), which is responsible for the conversion of biologically active EETs (epoxyeicosatrienoic acids) into biologically inactive DHETEs (dihydroxyeicosatrienoic acids), on BP (blood pressure) and myocardial infarct size in male heterozygous TGR (Ren-2 renin transgenic rats) with established hypertension. Normotensive HanSD (Hannover Sprague-Dawley) rats served as controls. Myocardial ischaemia was induced by coronary artery occlusion. Systolic BP was measured in conscious animals by tail plethysmography. c-AUCB was administrated in drinking water. Renal and myocardial concentrations of EETs and DHETEs served as markers of internal production of epoxygenase metabolites. Chronic treatment with c-AUCB, which resulted in significant increases in the availability of biologically active epoxygenase metabolites in TGR (assessed as the ratio of EETs to DHETEs), was accompanied by a significant reduction in BP and a significantly reduced infarct size in TGR as compared with untreated TGR. The cardioprotective action of c-AUCB treatment was completely prevented by acute administration of a selective EETs antagonist [14,15-epoxyeicosa-5(Z)-enoic acid], supporting the notion that the improved cardiac ischaemic tolerance conferred by sEH inhibition is mediated by EETs actions at the cellular level. These findings indicate that chronic inhibition of sEH exhibits antihypertensive and cardioprotective actions in this transgenic model of angiotensin II-dependent hypertension.

• MeSH
• angiotensin II fyziologie   MeSH
• antihypertenziva farmakologie   MeSH
• benzoáty farmakologie   MeSH
• epoxid hydrolasy antagonisté a inhibitory   MeSH
• hypertenze farmakoterapie   genetika   metabolismus   MeSH
• ikosanoidy metabolismus   moč   MeSH
• infarkt myokardu farmakoterapie   patologie   MeSH
• kardiotonika farmakologie   MeSH
• krevní tlak MeSH
• krysa rodu Rattus MeSH
• močovina analogy a deriváty   farmakologie   MeSH
• potkani Sprague-Dawley MeSH
• potkani transgenní MeSH
• srdeční arytmie farmakoterapie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• 4-(4-(3-adamantan-1-ylureido)cyclohexyloxy)benzoic acid MeSH Prohlížeč
• angiotensin II MeSH
• antihypertenziva MeSH
• benzoáty MeSH
• epoxid hydrolasy MeSH
• ikosanoidy MeSH
• kardiotonika MeSH
• močovina MeSH