Epigenetic deregulation of lamina-associated domains in Hutchinson-Gilford progeria syndrome

BACKGROUND

Hutchinson-Gilford progeria syndrome (HGPS) is a progeroid disease characterized by the early onset of age-related phenotypes including arthritis, loss of body fat and hair, and atherosclerosis. Cells from affected individuals express a mutant version of the nuclear envelope protein lamin A (termed progerin) and have previously been shown to exhibit prominent histone modification changes.

METHODS

Here, we analyze the possibility that epigenetic deregulation of lamina-associated domains (LADs) is involved in the molecular pathology of HGPS. To do so, we studied chromatin accessibility (Assay for Transposase-accessible Chromatin (ATAC)-see/-seq), DNA methylation profiles (Infinium MethylationEPIC BeadChips), and transcriptomes (RNA-seq) of nine primary HGPS fibroblast cell lines and six additional controls, two parental and four age-matched healthy fibroblast cell lines.

RESULTS

Our ATAC-see/-seq data demonstrate that primary dermal fibroblasts from HGPS patients exhibit chromatin accessibility changes that are enriched in LADs. Infinium MethylationEPIC BeadChip profiling further reveals that DNA methylation alterations observed in HGPS fibroblasts are similarly enriched in LADs and different from those occurring during healthy aging and Werner syndrome (WS), another premature aging disease. Moreover, HGPS patients can be stratified into two different subgroups according to their DNA methylation profiles. Finally, we show that the epigenetic deregulation of LADs is associated with HGPS-specific gene expression changes.

CONCLUSIONS

Taken together, our results strongly implicate epigenetic deregulation of LADs as an important and previously unrecognized feature of HGPS, which contributes to disease-specific gene expression. Therefore, they not only add a new layer to the study of epigenetic changes in the progeroid syndrome, but also advance our understanding of the disease's pathology at the cellular level.

[Constellations of findings and derived treatment interventions in telemedical monitoring of patients with heart failure, cardiac arrhythmia or increased risk for sudden cardiac death : Recommendations of the working group 33 telemonitoring of the German Cardiac Society]

The specification of standard operating procedures (SOPs) is a basic requirement for a successful implementation of telemonitoring with implanted cardiac devices and with external measuring devices in patients with heart failure, cardiac arrhytmia or increased risk of sudden cardiac death. The following article summarizes the possibilities of telemonitoring from a technical and organizational point of view and descibes basic requirements on SOPs. these basic requirements should be further specified and anchored in the organizational structure of the individual telemonitoring concept. Moreover, they should de understood as a basic guideline fpr the actions of telemonitoring center (TMC) employees.

DNA Methylation in Epidermal Differentiation, Aging, and Cancer

The formation and maintenance of the epidermis depend on epidermal stem cell differentiation and must be tightly regulated. Epigenetic mechanisms such as DNA methylation allow the precise gene expression cascade needed during cellular differentiation. However, these mechanisms become deregulated during aging and tumorigenesis, where cellular function and identity become compromised. Here we provide a review of this rapidly developing field. We discuss recent discoveries related to epidermal homeostasis, aging, and cancer, including the functional role of DNA methyltransferases, the methylation clock, and the determination of tumor cells-of-origin. Finally, we focus on future advances, greatly influenced by single-cell sequencing technologies.

[Incidental finding of mucinous neoplasia of the appendix : Treatment strategies]

Tumors of the appendix are not a uniform group but differ significantly in terms of their origin/histology and metastatic behavior. Furthermore, tumors of the appendix are often diagnosed as incidental findings after appendectomy for acute appendicitis. A subgroup of these neoplasms are low-grade appendiceal mucinous neoplasms (LAMN). These are mucus-forming tumors of the appendiceal lumen, which can lead to rupture of the appendix and seeding into the abdominal cavity. Therefore LAMN are considered precursors of pseudomyxoma peritonei (PMP). It is essential to clearly differentiate the subgroups of LAMN as well as the resection status. According to this it is determined whether (radical) appendectomy is a sufficient therapy or further treatment, such as ileocecal resection with hyperthermic intraperitoneal chemotherapy (HIPEC) or cytoreductive surgery (CRS) is necessary. There is no standardized concept regarding the follow-up after resection of LAMN. Generally, it is recommended to perform a computed tomography (CT) scan of the abdomen and determination of tumor markers 6 months postoperatively and then once a year. A recommendation regarding the duration of follow-up is difficult as there are case reports in which PMP has occurred more than 15 years after removal of LAMN.

Initial Characterization of Transgenic Mice Overexpressing Human Histamine H2 Receptors

In an integrative approach, we studied the role of histamine H₂ receptors in the mouse heart. We noted that histamine, added cumulatively to the organ bath, failed to affect the force of contraction in left atrial preparations and did not change spontaneous heart rate in right atrial preparations from wild-type mice. By contrast, in the same preparations from mice that overexpressed the human H₂ receptor in a cardiac-specific way, histamine exerted concentration- and time-dependent positive inotropic and positive chronotropic effects. Messenger RNA of the human H₂ receptor was only detected in transgenic mice. Likewise, immunohistology and autoradiography only gave signals in transgenic but not in wild-type cardiac preparations. Similarly, a positive inotropic and positive chronotropic effect was observed with histamine in echocardiography of living transgenic mice and isolated perfused hearts (Langendorff preparation). Phosphorylation of phospholamban was increased in atrial and ventricular preparations from transgenic mice, but not in wild-type animals. The effects of histamine were mimicked by dimaprit and amthamine and antagonized by cimetidine. In summary, we generated a new model to study the physiologic and pathophysiologic cardiac role of the human H₂ receptor.

Abstract 5333: Methylation profiling identifies two subclasses of cutaneous squamous cell carcinoma related to distinct cell types of origin

Cutaneous squamous cell carcinoma (cSCC) is the second most common skin cancer type and arises from keratinocytes. Most cSCC progress from a UV-induced precancerous lesion termed actinic keratosis (AK). Despite various efforts to characterize these lesions molecularly, the etiology of AK and its progression to cSCC remain only partially understood. Here we have used Infinium MethylationEPIC BeadChips to interrogate the DNA methylation status of about 850.000 CpGs in epidermis samples from healthy skin, AK and cSCC. Importantly, we found that the premalignant AK samples displayed classical features of cancer methylomes and were highly similar to cSCC methylomes. Further analysis identified typical features of stem cell methylomes, such as a reduced DNA methylation age, non-CpG methylation and stem cell-related keratin and enhancer methylation patterns. Interestingly, this signature was detected only in one half of the AK and cSCC samples, while the other half showed keratin and enhancer methylation patterns that were more closely related to the control epidermis. These findings suggest the existence of two distinct subclasses of AK and cSCC that originate from distinct keratinocyte differentiation stages.

Citation Format: Manuel Rodríguez Paredes, Felix Bormann, Günter Raddatz, Julian Gutekunst, Carlota Lucena-Porcel, Florian Köhler, Elisabeth Wurzer, Katrin Schmidt, Joachim Röwert-Huber, Evgeniya Denisova, Lars Feuerbach, Esther Herpel, Ingo Nindl, Thomas G. Hofmann, Marc Winnefeld, Frank Lyko. Methylation profiling identifies two subclasses of cutaneous squamous cell carcinoma related to distinct cell types of origin [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5333.

Methylation profiling identifies two subclasses of squamous cell carcinoma related to distinct cells of origin

Cutaneous squamous cell carcinoma (cSCC) is the second most common skin cancer and usually progresses from a UV-induced precancerous lesion termed actinic keratosis (AK). Despite various efforts to characterize these lesions molecularly, the etiology of AK and its progression to cSCC remain partially understood. Here, we use Infinium MethylationEPIC BeadChips to interrogate the DNA methylation status in healthy, AK and cSCC epidermis samples. Importantly, we show that AK methylation patterns already display classical features of cancer methylomes and are highly similar to cSCC profiles. Further analysis identifies typical features of stem cell methylomes, such as reduced DNA methylation age, non-CpG methylation, and stem cell-related keratin and enhancer methylation patterns. Interestingly, this signature is detected only in half of the samples, while the other half shows patterns more closely related to healthy epidermis. These findings suggest the existence of two subclasses of AK and cSCC emerging from distinct keratinocyte differentiation stages.

[The telemedical service centre as an essential element of the conceptual approach for telemonitoring of cardiac patients : Requirements on the service, quality, and technical realization of telemonitoring]

Telemonitoring as part of a treatment strategy supports and facilitates the monitoring, disease management and education of patients with heart failure and cardiac arrhythmias. Therefore, telemonitoring affects quality and success of the therapy. Thus, meeting the needs of the patients and of the involved health care professionals is important for the success of the telemonitoring service. Moreover, a high quality of the service has to be ensured. The following article describes several configuration options for telemonitoring services considering technical as well as quality- and service-related aspects.

Repetitive centromeric satellite RNA is essential for kinetochore formation and cell division

SAT III RNA binds to the kinetochore component CENP-C and is required for correct assembly and function of the kinetochore at centromeres.

Chromosome segregation requires centromeres on every sister chromatid to correctly form and attach the microtubule spindle during cell division. Even though centromeres are essential for genome stability, the underlying centromeric DNA is highly variable in sequence and evolves quickly. Epigenetic mechanisms are therefore thought to regulate centromeres. Here, we show that the 359-bp repeat satellite III (SAT III), which spans megabases on the X chromosome of Drosophila melanogaster, produces a long noncoding RNA that localizes to centromeric regions of all major chromosomes. Depletion of SAT III RNA causes mitotic defects, not only of the sex chromosome but also in trans of all autosomes. We furthermore find that SAT III RNA binds to the kinetochore component CENP-C, and is required for correct localization of the centromere-defining proteins CENP-A and CENP-C, as well as outer kinetochore proteins. In conclusion, our data reveal that SAT III RNA is an integral part of centromere identity, adding RNA to the complex epigenetic mark at centromeres in flies.

g Factor of lithiumlike silicon 28Si11+

The g factor of lithiumlike silicon (28)Si(11+) has been measured in a triple-Penning trap with a relative uncertainty of 1.1×10(-9) to be g(exp)=2.000 889 889 9(21). The theoretical prediction for this value was calculated to be g(th)=2.000 889 909(51) improving the accuracy to 2.5×10(-8) due to the first rigorous evaluation of the two-photon exchange correction. The measured value is in excellent agreement with the theoretical prediction and yields the most stringent test of bound-state QED for the g factor of the 1s(2)2s state and the relativistic many-electron calculations in a magnetic field.

The growth and electronic structure of azobenzene-based functional molecules on layered crystals

In situ ultraviolet photoelectron spectroscopy is used to study the growth of ultrathin films of azobenzene-based functional molecules (azobenzene, Disperse Orange 3 and a triazatriangulenium platform with an attached functional azo-group) on the layered metal TiTe(2) and on the layered semiconductor HfS(2) at liquid nitrogen temperatures. Effects of intermolecular interactions, of the substrate electronic structure, and of the thermal energy of the sublimated molecules on the growth process and on the adsorbate electronic structure are identified and discussed. A weak adsorbate-substrate interaction is particularly observed for the layered semiconducting substrate, holding the promise of efficient molecular photoswitching.

Pedometer accuracy in patients with chronic heart failure

This study assesses the accuracy of the Omron HJ-720ITC pedometer at low walking intensities in patients with chronic heart failure. Step accuracy was assessed by visual observation on the treadmill and during free walking at 40, 50, 60, 70, 80 m/min, as well as during self paced walking using the 6 min walk test. A total of ninety-seven patients with heart failure (mean age: 61+/-13, NYHA I, N=30; NYHA II, N=32; NYHA III, N=35) participated in the study. At predefined walking speeds, a statistically significant % error in pedometer accuracy was evident at 60 m/min (p=0.039), and% error increased markedly below this threshold. Highest% error in pedometer accuracy was seen at 40 m/min (mean bias (% error): 28.3+/-9.0%; 95% CI: 21.8-34.7; p<0.001). During self paced walking (6MWT) the absolute% error in pedometer readings was largest in patients with strongest functional limitations and 6 MWT distances <400 m (mean bias (% error): 10.7+/-13.6%; CI 5.6-15.4, p<0.001). The Omron HJ-720ITC pedometer is accurate for monitoring activity in individuals with normal walking behaviour, but seems unsuitable for chronically ill patients characterised by slow walking gaits.

Quantitative trait loci for white blood cell numbers in swine

Differential white blood cell counts are essential diagnostic parameters in veterinary practice but knowledge on the genetic architecture controlling variability of leucocyte numbers and relationships is sparse, especially in swine. Total leucocyte numbers (Leu) and the differential leucocyte counts, i.e. the fractions of lymphocytes (Lym), polymorphonuclear leucocytes [neutrophils (Neu), eosinophils (Eos) and basophils (Bas)] and monocytes (Mon) were measured in 139 F(2) pigs from a Meishan/Pietrain family, before and after challenge with the protozoan pathogen Sarcocystis miescheriana for genome-wide quantitative trait loci (QTL) analysis. After infection, the pigs passed through three stages representing acute disease, reconvalescence and chronic disease. Nine genome-wide significant and 29 putative, single QTL controlling leucocyte traits were identified on 15 chromosomes. Because leucocyte traits varied with health and disease status, QTL influencing the leucocyte phenotypes showed specific health/disease patterns. Regions on SSC1, 8 and 12 contained QTL for baseline leucocyte traits. Other QTL regions reached control on leucocyte traits only at distinct stages of the disease model. Two-thirds of the QTL have not been described before. Single QTL explained up to 19% of the phenotypic variance in the F(2) animals. Related traits were partly under common genetic influence. Our analysis confirms that leucocyte trait variation is associated with multiple chromosomal regions.

Quantitative trait loci for red blood cell traits in swine

Haematological traits are essential diagnostic parameters in veterinary practice but knowledge on the genetic architecture controlling variability of erythroid traits is sparse, especially in swine. To identify QTL for erythroid traits in the pig, haematocrit (HCT), haemoglobin (HB), erythrocyte counts (RBC) and mean corpuscular haemoglobin content (MCHC) were measured in 139 F(2) pigs from a Meishan/Pietrain family, before and after challenge with the protozoan pathogen Sarcocystis miescheriana. The pigs passed through three stages representing acute disease, reconvalescence and chronic disease. Forty-three single QTL controlling erythroid traits were identified on 16 chromosomes. Twelve of the QTL were significant at the genome-wide level while 31 were significant at a chromosome-wide level. Because erythroid traits varied with health and disease status, QTL influencing the erythroid phenotypes showed specific health/disease patterns. Regions on SSC5, 7, 8, 12 and 13 contained QTL for baseline erythroid traits, while the other QTL regions affected distinct stages of the disease model. Single QTL explained 9-17% of the phenotypic variance in the F(2) animals. Related traits were partly under common genetic influence. Our analysis confirms that erythroid trait variation differs between Meishan and Pietrain breeds and that this variation is associated with multiple chromosomal regions.

Mapping of quantitative trait loci affecting resistance/susceptibility to Sarcocystis miescheriana in swine

The outcome of infectious diseases in vertebrates is under genetic control at least to some extent. In swine, e.g., marked differences in resistance/susceptibility to Sarcocystis miescheriana have been shown between Chinese Meishan and European Pietrain pigs, and these differences are associated with high heritabilities. A first step toward the identification of genes and polymorphisms causal for these differences may be the mapping of quantitative trait loci (QTLs). Considering clinical, immunological, and parasitological traits in the above model system, this survey represents the first QTL study on parasite resistance in pigs. QTL mapping was performed in 139 F(2) pigs of a Meishan/Pietrain family infected with S. miescheriana. Fourteen genome-wide significant QTLs were mapped to several chromosomal areas. Among others, major QTLs were identified for bradyzoite numbers in skeletal muscles (F = 17.4; p < 0.001) and for S. miescheriana-specific plasma IgG(2) levels determined 42 days p.i. (F = 20.9; p < 0.001). The QTLs were mapped to different regions of chromosome 7, i.e., to the region of the major histocompatibility complex (bradyzoites) and to an immunoglobulin heavy chain cluster, respectively. These results provide evidence for a direct and causal role for gene variants within these gene clusters (cis-acting) in differences in resistance to S. miescheriana.

Downregulation of Apaf-1 and caspase-3 by RNA interference in human glioma cells: Consequences for erucylphosphocholine-induced apoptosis

Erucylphosphocholine (ErPC) exerts strong anticancer activity in vivo and in vitroand induces apoptosis even in chemoresistant glioma cell lines. We investigated the contribution of Apaf-1 and caspase-3 to the apoptotic response to ErPC using RNA interference (RNAi) in human glioblastoma cells. We could demonstrate that human glioma cell lines are susceptible to RNAi. Apaf-1 and caspase-3 are amenable to specific small interfering RNA (siRNA)-induced degradation resulting in a reduction of protein levels to 8-33% (Apaf-1) and to 30-50% (caspase-3). Transfection of siRNA directed to Apaf-1 and caspase-3 specifically reduced caspase-3 processing induced by ErPC treatment and yielded a reduction in cells that undergo ErPC-induced apoptosis to 17-33% (Apaf-1) and to 38-50% (caspase-3). The caspase-3 siRNA experiments were corroborated in caspase-3-deficient and -reconstituted MCF-7 breast cancer cells. Survival assays and morphological observations revealed that caspase-3 reconstitution significantly sensitized MCF-7 cells to ErPC. Exploring the caspase cascade responsible for ErPC-induced apoptosis MCF-7 cells provided evidence that caspase-3 is required for the activation of caspases-2, -6 and -8 and also participates in a feedback amplification loop. Our results provide evidence that Apaf-1 and caspase-3 are major determinants of ErPC-induced apoptosis and the possible use of ErPC in a clinical setting is discussed.

[The Estonian Genome Project in the context of European genome research]

It is the aim of the Estonian Genome Project to establish a database which compiles phenotype and genotype data of a large part of the Estonian population. The Gene Bank will only be used for scientific and public health research. Researchers hope that it will help identify disease genes and prepare the ground for the personalized medicine of the future. Additionally, the project will improve Estonian's international competitiveness in high technology and have a strong educational effect on the population. The legal framework, the Human Genes Research Act, was passed by the Estonian parliament in December 2000. It had been drafted by a group of experts who took into account all available international guidance documents on genetic research. With the pilot project involving three selected regions successfully finished, the main project has now started.

Femtosecond formation of coupled phonon-plasmon modes in InP: Ultrabroadband THz experiment and quantum kinetic theory

The ultrafast transition of an optical phonon resonance to a coupled phonon-plasmon system is studied. After 10-fs photoexcitation of i-InP, the buildup of coherent beats of the emerging hybrid modes is directly monitored via ultrabroadband THz spectroscopy. The anticrossing is mapped out as a function of time and density. A quantum kinetic theory of microscopic carrier-carrier and carrier-LO-phonon interactions explains the delayed formation of the collective modes. The buildup time is quantitatively reproduced to scale with the oscillation cycle of the upper branch of the coupled resonance.

[Health telematics/telemedicine in the republic of Estonia]

The people of Estonia, who until their independence had been systematically deprived of all forms of information, have shown a ready acceptance of the use of information technology in all areas of life. This environment and an excellent IT infrastructure have since the beginning of the new century provided favourable conditions for developing various individual projects in telemedicine. At the core of current telemedical applications in Estonia is the BITNET Project (in neurology, general medicine), built up with Swedish cooperation, and three German-Estonian projects (in telecardiology and telepathology). These projects are accompanied by studies of their cost-effectiveness. They constitute the basis for the plan that routine telemedical services be taken over by the Estonian health insurance. Differing from the situation in the Scandinavian countries, which have had an effective national telemedical service for over ten years, the special feature of telematrics in Estonia is its international networking with foreign centres of excellence. This has its origin in the aim of Estonian health policy to ensure medical services within its own country in all branches of medicine.

[Interventional cardiology in Latvia from 1993 to 2003]

A nationale programme for combatting cardiovascular diseases is being implemented in Letvia. A milestone was reached in 1993 with the establishment of a Letvian Centre for Cardiology. Within 10 years the only cardiac catheterization unit in the country has developed into a centre of excellence. But to meet the cardiological needs for all of Letvia requires at least three additional units for left heart catheterization and one for paediatric a cardiac catheterization.