Heart failure after pressure overload in autosomal-dominant desminopathies: Lessons from heterozygous DES-p.R349P knock-in mice

Background Mutations in the human desmin gene (DES) cause autosomal-dominant and -recessive cardiomyopathies, leading to heart failure, arrhythmias, and AV blocks. We analyzed the effects of vascular pressure overload in a patient-mimicking p.R349P desmin knock-in mouse model that harbors the orthologue of the frequent human DES missense mutation p. R350P. Methods and results Transverse aortic constriction (TAC) was performed on heterozygous (HET) DES-p.R349P mice and wild-type (WT) littermates. Echocardiography demonstrated reduced left ventricular ejection fraction in HET-TAC (WT-sham: 69.5 ± 2.9%, HET-sham: 64.5 ± 4.7%, WTTAC: 63.5 ± 4.9%, HET-TAC: 55.7 ± 5.4%; p<0.01). Cardiac output was significantly reduced in HET-TAC (WT sham: 13088 ± 2385 μl/min, HET sham: 10391 ± 1349μl/min, WT-TAC: 8097 ± 1903μl/min, HET-TAC: 5793 ± 2517μl/min; p<0.01). Incidence and duration of AV blocks as well as the probability to induce ventricular tachycardias was highest in HET-TAC. We observed reduced mtDNA copy numbers in HET-TAC (WT-sham: 12546 ± 406, HET-sham: 13526 ± 781, WT-TAC: 11155 ± 3315, HET-TAC: 8649 ± 1582; p = 0.025), but no mtDNA deletions. The activity of respiratory chain complexes I and IV showed the greatest reductions in HET-TAC. Conclusion Pressure overload in HET mice aggravated the clinical phenotype of cardiomyopathy and resulted in mitochondrial dysfunction. Preventive avoidance of pressure overload/arterial hypertension in desminopathy patients might represent a crucial therapeutic measure

Design, Construction, and Functional Characterization of a tRNA Neochromosome in Yeast

Here we report the design, construction and characterization of a tRNA neochromosome, a designer chromosome that functions as an additional, de novo counterpart to the native complement of Saccharomyces cerevisiae. Intending to address one of the central design principles of the Sc2.0 project, the ∼190 kb tRNA neochromosome houses all 275 relocated nuclear tRNA genes. To maximize stability, the design incorporated orthogonal genetic elements from non-S. cerevisiae yeast species. Furthermore, the presence of 283 rox recombination sites enable an orthogonal SCRaMbLE system capable of adjusting tRNA abundance. Following construction, we obtained evidence of a potent selective force once the neochromosome was introduced into yeast cells, manifesting as a spontaneous doubling in cell ploidy. Furthermore, tRNA sequencing, transcriptomics, proteomics, nucleosome mapping, replication profiling, FISH and Hi-C were undertaken to investigate questions of tRNA neochromosome behavior and function. Its construction demonstrates the remarkable tractability of the yeast model and opens up new opportunities to directly test hypotheses surrounding these essential non-coding RNAs

Design, construction, and functional characterization of a tRNA neochromosome in yeast

Here, we report the design, construction, and characterization of a tRNA neochromosome, a designer chromosome that functions as an additional, de novo counterpart to the native complement of Saccharomyces cerevisiae. Intending to address one of the central design principles of the Sc2.0 project, the ∼190-kb tRNA neochromosome houses all 275 relocated nuclear tRNA genes. To maximize stability, the design incorporates orthogonal genetic elements from non-S. cerevisiae yeast species. Furthermore, the presence of 283 rox recombination sites enables an orthogonal tRNA SCRaMbLE system. Following construction in yeast, we obtained evidence of a potent selective force, manifesting as a spontaneous doubling in cell ploidy. Furthermore, tRNA sequencing, transcriptomics, proteomics, nucleosome mapping, replication profiling, FISH, and Hi-C were undertaken to investigate questions of tRNA neochromosome behavior and function. Its construction demonstrates the remarkable tractability of the yeast model and opens up opportunities to directly test hypotheses surrounding these essential non-coding RNAs

Design, construction, and functional characterization of a tRNA neochromosome in yeast

Here, we report the design, construction, and characterization of a tRNA neochromosome, a designer chromosome that functions as an additional, de novo counterpart to the native complement of Saccharomyces cerevisiae. Intending to address one of the central design principles of the Sc2.0 project, the ∼190-kb tRNA neochromosome houses all 275 relocated nuclear tRNA genes. To maximize stability, the design incorporates orthogonal genetic elements from non-S. cerevisiae yeast species. Furthermore, the presence of 283 rox recombination sites enables an orthogonal tRNA SCRaMbLE system. Following construction in yeast, we obtained evidence of a potent selective force, manifesting as a spontaneous doubling in cell ploidy. Furthermore, tRNA sequencing, transcriptomics, proteomics, nucleosome mapping, replication profiling, FISH, and Hi-C were undertaken to investigate questions of tRNA neochromosome behavior and function. Its construction demonstrates the remarkable tractability of the yeast model and opens up opportunities to directly test hypotheses surrounding these essential non-coding RNAs

Microcalcification-associated breast cancer: presentation, successful first excision, long-term recurrence and survival rate

INTRODUCTION: In this study we evaluated mammographic, histological and immunohistochemical findings for microcalcification-associated breast cancer with regards to breast-conserving therapy, recurrence and survival rate. PATIENTS AND METHODS: We retrospectively analyzed 99 consecutive, non-palpable and microcalcification-associated breast cancers (94 women) that were treated surgically between January 2002 and December 2003 at a national academic breast cancer center. Calcifications were classified according to the Breast Imaging Reporting and Data System (BI-RADS). Descriptors, surgical outcome and histological findings were assessed. Recurrences and survival rates were evaluated based on medical records, standardized patient questionnaires and/or contacting the physician. RESULTS: 42 of the 99 lesions (42.4%) were invasive carcinomas, 57 (57.6%) were pure ductal carcinoma in situ (DCIS). 6 out of 99 (6.1%) lesions were triple negative, and 29 (29.3%) were HER2/neu positive. Successful first excision rate was 76/99 lesions (76.8%). Breast conservation was achieved in 73.7% (73/99). 10 women showed local recurrences without negatively impacting survival. The recurrences included round/punctate, amorphous, fine pleomorphic, and fine linear or fine-linear branching descriptors. The breast cancer-specific long-term survival rate was 91/94 (96.8%) for a mean follow-up of 81.4 months. The 3 patients who died due to breast carcinoma showed fine pleomorphic calcifications, and had nodal-positive invasive carcinoma at diagnosis. CONCLUSION: Microcalcification-associated breast cancers are frequently treated with breast-conserving therapy. Continuous clinical and mammographic follow-up is recommended for all descriptors

Prehabilitation in patients awaiting elective coronary artery bypass graft surgery – effects on functional capacity and quality of life: a randomized controlled trial

Objective: To determine the impact of an exercise-based prehabilitation (EBPrehab) program on preand postoperative exercise capacity, functional capacity (FC) and quality of life (QoL) in patients awaiting elective coronary artery bypass graft surgery (CABG). Design: A two-group randomized controlled trail. Setting: Ambulatory prehabilitation. Subjects: Overall 230 preoperative elective CABG-surgery patients were randomly assigned to an intervention (IG, n=88; n=27 withdrew after randomization) or control group (CG, n=115). Intervention: IG: two-week EBPrehab including supervised aerobic exercise. CG: usual care. Main measures: At baseline (T1), one day before surgery (T2), at the beginning (T3) and at the end of cardiac rehabilitation (T4) the following measurements were performed: cardiopulmonary exercise test, six-minute walk test (6MWT), Timed-Up-and-Go Test (TUG) and QoL (MacNew questionnaire). Results: A total of 171 patients (IG, n=81; CG, n=90) completed the study. During EBPrehab no complications occurred. Preoperatively FC (6MWTIG: 443.0±80.1m to 493.5±75.5m, P=0.003; TUGIG: 6.9±2.0 s to 6.1±1.8 s, P=0.018) and QoL (IG: 5.1±0.9 to 5.4±0.9, P<0.001) improved significantly more in IG compared to CG. Similar effects were observed postoperatively in FC (6MWDIG: Δ-64.7m, pT1–T3=0.013; Δ+47.2m, pT1–T4<0.001; TUGIG: Δ+1.4s, pT1–T3=0.003). Conclusions: A short-term EBPrehab is effective to improve perioperative FC and preoperative QoL in patients with stable coronary artery disease awaiting CABG-surgery

Data-collection strategy for challenging native SAD phasing

Recent improvements in data-collection strategies have pushed the limits of native SAD (single-wavelength anomalous diffraction) phasing, a method that uses the weak anomalous signal of light elements naturally present in macromolecules. These involve the merging of multiple data sets from either multiple crystals or from a single crystal collected in multiple orientations at a low X-ray dose. Both approaches yield data of high multiplicity while minimizing radiation damage and systematic error, thus ensuring accurate measurements of the anomalous differences. Here, the combined use of these two strategies is described to solve cases of native SAD phasing that were particular challenges: the integral membrane diacylglycerol kinase (DgkA) with a low Bijvoet ratio of 1% and the large 200 kDa complex of the CRISPR-associated endonuclease (Cas9) bound to guide RNA and target DNA crystallized in the low-symmetry space group C2. The optimal native SAD data-collection strategy based on systematic measurements performed on the 266 kDa multiprotein/multiligand tubulin complex is discussed

Malignant cardiac phenotype after pressure overload in autosomal-dominant desminopathies: Lessons from heterozygous R349P desmin knock-in mice

Mutations of the human desmin gene on chromosome 2q35 cause autosomal-dominant and -recessive myopathies and ardiomyopathies. For pathophysiological and therapeutic studies, we generated a R349P desmin knock-in mouse strain, which serves as patient-mimicking disease model for desminopathies. Here, we investigated the influence of pressure overload on cardiac function in heterozygous R349P desmin knock-in mice. Young, non-operated heterozygous R349P desmin knock-in mice do not show obvious signs of cardiomyopathy. When subjected to pressure overload by TAC operation, these mice develop marked signs of cardiomyopathy with accompanying arrhythmias and atrioventricular blocks. The cardiac disease manifestations are associated with reductions in mitochondrial respiratory chain complex activities and mitochondrial DNA copy numbers. Preventive avoidance of pressure overload, i.e. arterial hypertension, to the heart may thus represent a crucial therapeutic measure. Heterozygous R349P desmin knock-in mice and their wild-type siblings were used. Transverse aortic constriction (TAC) operation was performed to induce pressure overload. Cardiac function was analyzed by left heart catheterization, electrophysiological investigation, and echocardiography. Moreover, mitochondrial respiratory complex activities, mtDNA copy number, and mtDNA integrity were investigated

The prevalence and impact of sarcopenia in older cardiac patients undergoing inpatient cardiac rehabilitation – results from a prospective, observational cohort pre-study

Abstract Background The prevalence of sarcopenia and its impact in older patients undergoing inpatient cardiac rehabilitation (iCR) after cardiac procedure has been insufficiently studied. The main aim of this study was to evaluate the prevalence of sarcopenia and quantify the functional capacity of older sarcopenic and non-sarcopenic patients participating in iCR. Methods Prospective, observational cohort study within the framework of the ongoing multicenter prehabilitation study “PRECOVERY”. A sample of 122 patients ≥75 years undergoing iCR after cardiac procedure were recruited in four German iCR facilities and followed up 3 months later by telephone. At iCR (baseline), the Strength, Assistance with walking, Rise from a chair, Climb stairs and Falls (SARC-F) questionnaire was used to identify sarcopenic patients. In addition, Katz-Index, Clinical Frailty Scale (CFS), handgrip strength (HGS), Short Physical Performance Battery (SPPB) and 6-minute walk distance (6MWD) measured functional capacity and frailty at baseline. Outcomes were prevalence of sarcopenia and the correlation of sarcopenia to functional capacity and frailty at baseline as well as the SARC-F score at follow-up. The Wilcoxon test was applied for pre-post-test analysis. Correlation between sarcopenia and 6MWD, SPPB score and HGS was tested with the eta coefficient with one-way ANOVA. Results Complete assessments were collected from 101 patients (79.9 ± 4.0 years; 63% male). At baseline, the mean SARC-F score was 2.7 ± 2.1; 35% with sarcopenia. Other baseline results were Katz-Index 5.7 ± 0.9, CFS 3.2 ± 1.4, HGS 24.9 ± 9.9 kg, SPPB score 7.5 ± 3.3 and 6MWD 288.8 ± 136.5 m. Compared to baseline, fewer patients were sarcopenic (23% versus 35%) at follow-up. In the subgroup of sarcopenic patients at baseline (n = 35), pre-post comparison resulted in a significant SARC-F improvement (p = 0.017). There was a significant correlation between sarcopenia measured by SARC-F and poor results in the assessments of functional capacity (p  0.546). Conclusions The prevalence of sarcopenia in older patients at iCR after cardiac procedure is high (35%) and remains high at follow-up (23%). Sarcopenia screening is important since the diagnosis of sarcopenia in these patients correlates significantly with poor functional capacity. The results indicate that these patients may benefit from prehabilitation aimed at improving perioperative outcomes, increasing functional capacity and mitigating adverse effects. Trial registration German Clinical Trials Register (DRKS; http://www.drks.de ; DRKS00032256). Retrospectively registered on 13 July 2023