Genetic factors strongly contribute to the pathogenesis of sporadic Alzheimer's disease (AD). Nevertheless, genome-wide association studies only yielded single nucleotide polymorphism loci of moderate importance. In contrast, microsatellite repeats are functionally less characterized structures within our genomes. Previous work has shown that endothelin-converting enzyme-1 (ECE-1) is able to reduce amyloid β content. Here we demonstrate that a CpG-CA repeat within the human ECE-1c promoter is highly polymorphic, harbors transcriptional start sites, is able to recruit the transcription factors poly(ADP-ribose) polymerase-1 and splicing factor proline and glutamine-rich, and is functional regarding haplotype-specific promoter activity. Furthermore, genotyping of 403 AD patients and 444 controls for CpG-CA repeat length indicated shifted allelic frequency distributions. Sequencing of 245 haplotype clones demonstrated that the overall CpG-CA repeat composition of AD patients and controls is distinct. Finally, we show that human and chimpanzee [CpG] m –[CA] n ECE-1c promoter repeats are genetically and functionally distinct. Our data indicate that a short genomic repeat structure constitutes a novel core promoter element, coincides with human evolution, and contributes to the pathogenesis of AD.
Prevention of diabetes represents an important therapeutic goal in current cardiovascular risk reduction strategies. Blockade of the renin–angiotensin system has been shown to markedly reduce the incidence of new-onset diabetes in different patient populations. Recent results from three large clinical endpoint trials with the angiotensin-II receptor blocker telmisartan regarding new-onset diabetes, atrial fibrillation, and left ventricular hypotrophy will be discussed.
We have recently shown that exercise-induced cardiac hypertrophy is regulated in a sex-specific manner. In accordance with increased exercise-mediated hypertrophic responses, female mice showed inc...
Background Successful reduction of body weight (BW) is often followed by recidivism to obesity. BW-changes including BW-loss and -regain is associated with marked alterations in energy expenditure (EE) and adipose tissue (AT) metabolism. Since these processes are sex-specifically controlled, we investigated sexual dimorphisms in metabolic processes during BW-dynamics (gain-loss-regain). Research Design Obesity was induced in C57BL/6J male (m) and female (f) mice by 15 weeks high-fat diet (HFD) feeding. Subsequently BW was reduced (-20%) by caloric restriction (CR) followed by adaptive feeding, and a regain-phase. Measurement of EE, body composition, blood/organ sampling were performed after each feeding period. Lipolysis was analyzed ex-vivo in gonadal AT. Results Male mice exhibited accelerated BW-gain compared to females (relative BW-gain m:140.5±3.2%; f:103.7±6.5%; p<0.001). In consonance, lean mass-specific EE was significantly higher in females compared to males during BW-gain. Under CR female mice reached their target-BW significantly faster than male mice (m:12.2 days; f:7.6 days; p<0.001) accompanied by a sustained sex-difference in EE. In addition, female mice predominantly downsized gonadal AT whereas the relation between gonadal and total body fat was not altered in males. Accordingly, only females exhibited an increased rate of forskolin-stimulated lipolysis in AT associated with significantly higher glycerol concentrations, lower RER-values, and increased AT expression of adipose triglyceride lipase (ATGL) and hormone sensitive lipase (HSL). Analysis of AT lipolysis in estrogen receptor alpha (ERα)–deficient mice revealed a reduced lipolytic rate in the absence of ERα exclusively in females. Finally, re-feeding caused BW-regain faster in males than in females. Conclusion The present study shows sex-specific dynamics during BW-gain-loss-regain. Female mice responded to CR with an increase in lipolytic activity, and augmented lipid-oxidation leading to more efficient weight loss. These processes likely involve ERα-dependent signaling in AT and sexual dimorphic regulation of genes involved in lipid metabolism.
