Proteomic and Functional Studies Reveal Detyrosinated Tubulin as Treatment Target in Sarcomere Mutation-Induced Hypertrophic Cardiomyopathy

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is the most common genetic heart disease. While ≈50% of patients with HCM carry a sarcomere gene mutation (sarcomere mutation-positive, HCMSMP), the genetic background is unknown in the other half of the patients (sarcomere mutation-negative, HCMSMN). Genotype-specific differences have been reported in cardiac function. Moreover, HCMSMN patients have later disease onset and a better prognosis than HCMSMP patients. To define if genotype-specific derailments at the protein level may explain the heterogeneity in disease development, we performed a proteomic analysis in cardiac tissue from a clinically well-phenotyped HCM patient group. METHODS: A proteomics screen was performed in cardiac tissue from 39 HCMSMP patients, 11HCMSMN patients, and 8 nonfailing controls. Patients with HCM had obstructive cardiomyopathy with left ventricular outflow tract obstruction and diastolic dysfunction. A novel MYBPC32373insG mouse model was used to confirm functional relevance of our proteomic findings. RESULTS: In all HCM patient samples, we found lower levels of metabolic pathway proteins and higher levels of extracellular matrix proteins. Levels of total and detyrosinated α-tubulin were markedly higher in HCMSMP than in HCMSMN and controls. Higher tubulin detyrosination was also found in 2 unrelated MYBPC3 mouse models and its inhibition with parthenolide normalized contraction and relaxation time of isolated cardiomyocytes. CONCLUSIONS: Our findings indicate that microtubules and especially its detyrosination contribute to the pathomechanism of patients with HCMSMP. This is of clinical importance since it represents a potential treatment target to improve cardiac function in patients with HCMSMP, whereas a beneficial effect may be limited in patients with HCMSMN

Are physical symptoms among survivors of a disaster presented to the general practitioner? A comparison between self-reports and GP data

<p>Abstract</p> <p>Background</p> <p>Most studies examining medically unexplained symptoms (MUS) have been performed in primary or secondary care and have examined symptoms for which patients sought medical attention. Disasters are often described as precipitating factors for MUS. However, health consequences of disasters are typically measured by means of questionnaires, and it is not known whether these self-reported physical symptoms are presented to the GP. It is also not known if the self-reported symptoms are related to a medical disorder or if they remain medically unexplained. In the present study, three research questions were addressed. Firstly, were self-reported symptoms among survivors presented to the GP? Secondly, were the symptoms presented to the GP associated with a high level of functional impairment and distress? Thirdly, what was the GP's clinical judgment of the presented symptoms, i.e. were the symptoms related to a medical diagnosis or could they be labeled MUS?</p> <p>Methods</p> <p>Survivors of a man-made disaster (N = 887) completed a questionnaire 3 weeks (T1) and 18 months (T2) post-disaster. This longitudinal health survey was combined with an ongoing surveillance program of health problems registered by GPs.</p> <p>Results</p> <p>The majority of self-reported symptoms was not presented to the GP and survivors were most likely to present persistent symptoms to the GP. For example, survivors with stomachache at both T1 and T2 were more likely to report stomachache to their GP (28%) than survivors with stomachache at only T1 (6%) or only T2 (13%). Presentation of individual symptoms to the GP was not consistently associated with functional impairment and distress. 56 – 91% of symptoms were labeled as MUS after clinical examination.</p> <p>Conclusion</p> <p>These results indicate that the majority of self-reported symptoms among survivors of a disaster are not presented to the GP and that the decision to consult with a GP for an individual symptom is not dependent on the level of impairment and distress. Also, self-reported physical symptoms such as headache, back pain and shortness of breath are likely to remain medically unexplained after the clinical judgment of a GP.</p

Multi-omics integration identifies key upstream regulators of pathomechanisms in hypertrophic cardiomyopathy due to truncating MYBPC3 mutations

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is the most common genetic disease of the cardiac muscle, frequently caused by mutations in MYBPC3. However, little is known about the upstream pathways and key regulators causing the disease. Therefore, we employed a multi-omics approach to study the pathomechanisms underlying HCM comparing patient hearts harboring MYBPC3 mutations to control hearts. RESULTS: Using H3K27ac ChIP-seq and RNA-seq we obtained 9310 differentially acetylated regions and 2033 differentially expressed genes, respectively, between 13 HCM and 10 control hearts. We obtained 441 differentially expressed proteins between 11 HCM and 8 control hearts using proteomics. By integrating multi-omics datasets, we identified a set of DNA regions and genes that differentiate HCM from control hearts and 53 protein-coding genes as the major contributors. This comprehensive analysis consistently points toward altered extracellular matrix formation, muscle contraction, and metabolism. Therefore, we studied enriched transcription factor (TF) binding motifs and identified 9 motif-encoded TFs, including KLF15, ETV4, AR, CLOCK, ETS2, GATA5, MEIS1, RXRA, and ZFX. Selected candidates were examined in stem cell-derived cardiomyocytes with and without mutated MYBPC3. Furthermore, we observed an abundance of acetylation signals and transcripts derived from cardiomyocytes compared to non-myocyte populations. CONCLUSIONS: By integrating histone acetylome, transcriptome, and proteome profiles, we identified major effector genes and protein networks that drive the pathological changes in HCM with mutated MYBPC3. Our work identifies 38 highly affected protein-coding genes as potential plasma HCM biomarkers and 9 TFs as potential upstream regulators of these pathomechanisms that may serve as possible therapeutic targets

The role of schools in the spread of mumps among unvaccinated children: a retrospective cohort study

Contains fulltext : 98461.pdf (publisher's version ) (Open Access)BACKGROUND: In the Netherlands, epidemics of vaccine preventable diseases are largely confined to an orthodox protestant minority with religious objections to vaccination. The clustering of unvaccinated children in orthodox protestant schools can foster the spread of epidemics. School closure has nevertheless not been practiced up until now. A mumps epidemic in 2007-2008 gave us an opportunity to study the role of schools in the spread of a vaccine preventable disease in a village with low vaccination coverage. METHODS: A retrospective cohort study was conducted among the students in four elementary schools and their siblings. The following information was collected for each child: having had the mumps or not and when, school, age, MMR vaccination status, household size, presence of high school students in the household, religious denomination, and home village. The spread of mumps among unvaccinated children was compared for the four schools in a Kaplan-Meier analysis using a log-rank test. Cox proportional hazard analyses were performed to test for the influence of other factors. To correct for confounding, a univariate Cox regression model with only school included as a determinant was compared to a multivariate regression model containing all possible confounders. RESULTS: Out of 650 households with children at the schools, 54% completed a questionnaire, which provided information on 1191 children. For the unvaccinated children (N = 769), the Kaplan-Meier curves showed significant differences among the schools in their cumulative attack rates. After correction for confounding, the Cox regression analysis showed the hazard of mumps to be higher in one orthodox protestant school compared to the other (hazard ratio 1.43, p < 0.001). Household size independently influenced the hazard of mumps (hazard ratio 1.44, p < 0.005) with children in larger households running a greater risk. CONCLUSION: If and when unvaccinated children got mumps was determined by the particular school the children and their siblings attended, and by the household size. This finding suggests that school closure can influence the spread of an epidemic among orthodox protestant populations, provided that social distancing is adhered to as well. Further research on the effects of school closure on the final attack rate is nevertheless recommended

Segregation of myoblast fusion and muscle-specific gene expression by distinct ligand-dependent inactivation of GSK-3β

Myogenic differentiation involves myoblast fusion and induction of muscle-specific gene expression, which are both stimulated by pharmacological (LiCl), genetic, or IGF-I-mediated GSK-3β inactivation. To assess whether stimulation of myogenic differentiation is common to ligand-mediated GSK-3β inactivation, myoblast fusion and muscle-specific gene expression were investigated in response to Wnt-3a. Moreover, crosstalk between IGF-I/GSK-3β/NFATc3 and Wnt/GSK-3β/β-catenin signaling was assessed. While both Wnt-3a and LiCl promoted myoblast fusion, muscle-specific gene expression was increased by LiCl, but not by Wnt-3a or β-catenin over-expression. Furthermore, LiCl and IGF-I, but not Wnt-3a, increased NFATc3 transcriptional activity. In contrast, β-catenin-dependent transcriptional activity was increased by Wnt-3a and LiCl, but not IGF-I. These results for the first time reveal a segregated regulation of myoblast fusion and muscle-specific gene expression following stimulation of myogenic differentiation in response to distinct ligand-specific signaling routes of GSK-3β inactivation

Lonely but avoidant—the unfortunate juxtaposition of loneliness and self-disgust

Loneliness is prevalent worldwide and is a known risk factor for numerous physical and mental health outcomes. The health consequences of chronic loneliness coupled with the cost on public health care has necessitated the development of interventions and campaigns to end loneliness globally. According to a recent meta-analysis, such interventions focus on improving social skills, increasing opportunities for social contact/support (i.e., reducing social isolation) or addressing maladaptive cognition (e.g., irrational thoughts, self-defeating, and self-blame thoughts). The results showed that changing maladaptive thoughts offer “the best chance” for alleviating feelings of loneliness. In accordance with the latter approach, this paper proposes a new paradigm in understanding and treating loneliness that takes into account self-disgust, an aversive self-conscious affective state that reflects disgust directed towards the self. Based on findings from published and unpublished data, it is argued that interventions against loneliness that focus exclusively on improving social skills and increasing opportunities for social contact may be ineffective because lonelier people experience more self-disgust, which makes them more socially inhibited and reluctant to connect with other people. Future interventions should consider self-disgust in the treatment of loneliness and explore ways to counter feelings of self-disgust

The copper-transporting capacity of ATP7A mutants associated with Menkes disease is ameliorated by COMMD1 as a result of improved protein expression

Menkes disease (MD) is an X-linked recessive disorder characterized by copper deficiency resulting in a diminished function of copper-dependent enzymes. Most MD patients die in early childhood, although mild forms of MD have also been described. A diversity of mutations in the gene encoding of the Golgi-resident copper-transporting P1B-type ATPase ATP7A underlies MD. To elucidate the molecular consequences of the ATP7A mutations, various mutations in ATP7A associated with distinct phenotypes of MD (L873R, C1000R, N1304S, and A1362D) were analyzed in detail. All mutants studied displayed changes in protein expression and intracellular localization parallel to a dramatic decline in their copper-transporting capacity compared to ATP7A the wild-type. We restored these observed defects in ATP7A mutant proteins by culturing the cells at 30°C, which improves the quality of protein folding, similar to that which as has recently has been demonstrated for misfolded ATP7B, a copper transporter homologous to ATP7A. Further, the effect of the canine copper toxicosis protein COMMD1 on ATP7A function was examined as COMMD1 has been shown to regulate the proteolysis of ATP7B proteins. Interestingly, in addition to adjusted growth temperature, binding of COMMD1 partially restored the expression, subcellular localization, and copper-exporting activities of the ATP7A mutants. However, no effect of pharmacological chaperones was observed. Together, the presented data might provide a new direction for developing therapies to improve the residual exporting activity of unstable ATP7A mutant proteins, and suggests a potential role for COMMD1 in this process

Co-morbidity and visual acuity are risk factors for health-related quality of life decline: five-month follow-up EQ-5D data of visually impaired older patients

<p>Abstract</p> <p>Background</p> <p>Co-morbidity is a common phenomenon in the elderly and is considered to be a major threat to quality of life (QOL). Knowledge of co-existing conditions or patient characteristics that lead to an increased QOL decline is important for individual care, and for public health purposes. In visually impaired older adults, it remains unclear which co-existing conditions or other characteristics influence their health-related QOL. Our aim was to present a risk profile of characteristics and conditions which predict deterioration of QOL in visually impaired older patients.</p> <p>Methods</p> <p>Analyses were performed on data from an observational study among 296 visually impaired older patients from four Dutch hospitals. QOL was measured with the EuroQol-5D (EQ-5D) at baseline and at five-month follow-up. Nine co-existing condition categories (musculoskeletal; diabetes; heart; hypertension; chronic obstructive pulmonary disease (COPD) or asthma; hearing impairment; stroke; cancer; gastrointestinal conditions) and six patient characteristics (age; gender; visual acuity; social status; independent living; rehabilitation type) were tested in a linear regression model to determine the risk profile. The model was corrected for baseline EQ-5D scores. In addition, baseline EQ-5D scores were compared with reference scores from a younger visually impaired population and from elderly in the general population.</p> <p>Results</p> <p>From the 296 patients, 50 (16.9%) were lost to follow-up. Patients who reported diabetes, COPD or asthma, consequences of stroke, musculoskeletal conditions, cancer, gastrointestinal conditions or higher logMAR Visual Acuity values, experienced a lower QOL. After five months, visual acuity, musculoskeletal conditions, COPD/asthma and stroke predicted a decline in QOL (R²= 0.20). At baseline, the visually impaired older patients more often reported moderate or severe problems on most EQ-5D dimensions than the two reference groups.</p> <p>Conclusion</p> <p>In visually impaired older patients, visual acuity, musculoskeletal conditions, COPD/asthma and stroke predicted a relatively rapid decline in health-related QOL. With this risk profile, a specific referral by the ophthalmologist to another sub-specialty may have a beneficial effect on the patient's health-related QOL. A referral by the ophthalmologist or optometrist to a multidisciplinary rehabilitation service seems appropriate for some patients with co-morbidity. The current results need to be confirmed in studies using pre-structured questionnaires to assess co-morbidity.</p

Primary care nurses: effects on secondary care referrals for diabetes

Background: Primary care nurses play an important role in diabetes care, and were introduced in GP-practice partly to shift care from hospital to primary care. The aim of this study was to assess whether the referral rate for hospital treatment for diabetes type II (T2DM) patients has changed with the introduction of primary care nurses, and whether these changes were related to the number of diabetes-related contacts in a general practice. Methods: Healthcare utilisation was assessed for a period of 365 days for 301 newly diagnosed and 2124 known T2DM patients in 2004 and 450 and 3226 patients in 2006 from general practices that participated in the Netherlands Information Network of General Practice (LINH). Multilevel logistic and linear regression analyses were used to analyse the effect of the introduction of primary care nurses on referrals to internists, ophthalmologists and cardiologists and diabetes-related contact rate. Separate analyses were conducted for newly diagnosed and known T2DM patients. Results: Referrals to internists for newly diagnosed T2DM patients decreased between 2004 and 2006 (OR:0.44; 95%CI:0.22-0.87) in all practices. For known T2DM patients no overall decrease in referrals to internists was found, but practices with a primary care nurse had a lower trend (OR:0.59). The number of diabetes-related contacts did not differ between practices with and without primary care nurses. Cardiologists’ and ophthalmologists’ referral rate did not change. Conclusions: The introduction of primary care nurses seems to have led to a shift of care from internists to primary care for known diabetes patients, while the diabetes-related contact rate seem to have remained unchanged.