Parkinson's disease (PD) is frequently associated with a prodromal sensory neuropathy manifesting with sensory loss and chronic pain. We have recently shown that PD-associated sensory neuropathy in ...patients is associated with high levels of glucosylceramides. Here, we assessed the underlying pathology and mechanisms in Pink1
SNCA
double mutant mice.
We studied nociceptive and olfactory behaviour and the neuropathology of dorsal root ganglia (DRGs), including ultrastructure, mitochondrial respiration, transcriptomes, outgrowth and calcium currents of primary neurons, and tissue ceramides and sphingolipids before the onset of a PD-like disease that spontaneously develops in Pink1
SNCA
double mutant mice beyond 15 months of age.
Similar to PD patients, Pink1
SNCA
mice developed a progressive prodromal sensory neuropathy with a loss of thermal sensitivity starting as early as 4 months of age. In analogy to human plasma, lipid analyses revealed an accumulation of glucosylceramides (GlcCer) in the DRGs and sciatic nerves, which was associated with pathological mitochondria, impairment of mitochondrial respiration, and deregulation of transient receptor potential channels (TRPV and TRPA) at mRNA, protein and functional levels in DRGs. Direct exposure of DRG neurons to GlcCer caused transient hyperexcitability, followed by a premature decline of the viability of sensory neurons cultures upon repeated GlcCer application.
The results suggest that pathological GlcCer contribute to prodromal sensory disease in PD mice via mitochondrial damage and calcium channel hyperexcitability. GlcCer-associated sensory neuron pathology might be amenable to GlcCer lowering therapeutic strategies.
Plants and many lower organisms, but not mammals, express alternative oxidases (AOXs) that branch the mitochondrial respiratory chain, transferring electrons directly from ubiquinol to oxygen without ...proton pumping. Thus, they maintain electron flow under conditions when the classical respiratory chain is impaired, limiting excess production of oxygen radicals and supporting redox and metabolic homeostasis. AOX from Ciona intestinalis has been used to study and mitigate mitochondrial impairments in mammalian cell lines, Drosophila disease models and, most recently, in the mouse, where multiple lentivector-AOX transgenes conferred substantial expression in specific tissues. Here, we describe a genetically tractable mouse model in which Ciona AOX has been targeted to the Rosa26 locus for ubiquitous expression. The AOX
mouse exhibited only subtle phenotypic effects on respiratory complex formation, oxygen consumption or the global metabolome, and showed an essentially normal physiology. AOX conferred robust resistance to inhibitors of the respiratory chain in organello; moreover, animals exposed to a systemically applied LD50 dose of cyanide did not succumb. The AOX
mouse is a useful tool to investigate respiratory control mechanisms and to decipher mitochondrial disease aetiology in vivo.
Introduction
The aim of this study was to describe the real-word treatment and associated healthcare resource use (HCRU) of multiple sclerosis (MS) patients, as stratified by different MS subtypes.
...Methods
All patients with MS continuously insured by two German statutory healthcare insurance funds from 2011 to 2015 were enrolled. These patients were categorized into four subgroups according to their MS type as follows: clinically isolated syndrome (CIS); relapsing remittent MS (RRMS); primary progressive MS (PPMS); and secondary progressive MS (SPMS). Sociodemographic characteristics, treatments, and HCRU for 2015 were analyzed. Treatment cascades for treatment-naïve patients were also determined.
Results
A total of 13,333 patients with MS were identified. The largest proportion of patients had RRMS (41.9%), followed by PPMS (17.1%). Mean age of the enrolled patients was 50.2 years, and 70.7% were female. Among all patients, 38.3% of those with CIS, 22.4% with PPMS, 69.6% with RRMS, and 33.9% with SPMS received a prescription of a disease-modifying immunomodulatory agent, with interferon beta-1a being the most frequently prescribed agent. Likewise, 14.5, 18.5, 19.9, and 21.5% of patients with CIS, PPMS, RRMS, and SPMS, respectively, received a flare-up treatment with glucocorticoids. MS-associated overall costs, including indirect costs for MS-associated days absent from work, were € 16,433, with costs related to MS medication (€ 8770; 53.4%) being the main driver of costs in all subgroups. MS-associated costs according to MS subtypes were € 12,427 for CIS patients, € 14,459 for PPMS patients, € 20,583 for RRMS patients, and € 17,554 for SPMS patients.
Conclusion
Among the four MS subtypes, RRMS patients most often received a disease-modifying immunomodulatory treatment. Consequently, healthcare costs were highest for patients with this MS subtype. Contrary to the treatment guideline, a substantial percentage of patients with CIS, RRMS, and SPMS did not receive any disease-modifying immunomodulatory treatment.
Cardiac ischaemia‐reperfusion (I/R) injury has been attributed to stress signals arising from an impaired mitochondrial electron transport chain (ETC), which include redox imbalance, metabolic ...stalling and excessive production of reactive oxygen species (ROS). The alternative oxidase (AOX) is a respiratory enzyme, absent in mammals, that accepts electrons from a reduced quinone pool to reduce oxygen to water, thereby restoring electron flux when impaired and, in the process, blunting ROS production. Hence, AOX represents a natural rescue mechanism from respiratory stress. This study aimed to determine how respiratory restoration through xenotopically expressed AOX affects the re‐perfused post‐ischaemic mouse heart. As expected, AOX supports ETC function and attenuates the ROS load in post‐anoxic heart mitochondria. However, post‐ischaemic cardiac remodelling over 3 and 9 weeks was not improved. AOX blunted transcript levels of factors known to be up‐regulated upon I/R such as the atrial natriuretic peptide (Anp) whilst expression of pro‐fibrotic and pro‐apoptotic transcripts were increased. Ex vivo analysis revealed contractile failure at nine but not 3 weeks after ischaemia whilst label‐free quantitative proteomics identified an increase in proteins promoting adverse extracellular matrix remodelling. Together, this indicates an essential role for ETC‐derived signals during cardiac adaptive remodelling and identified ROS as a possible effector.
To evaluate neurocognitive changes and predict neurocognitive outcome after ventriculoperitoneal shunting for idiopathic normal pressure hydrocephalus (INPH).
Reports of neurocognitive response to ...shunting have been variable and studies that predict cognitive outcomes after shunting are limited. We reviewed our experience with cognitive outcomes for INPH patients who were selected for shunting based on abnormal cerebrospinal fluid (CSF) pressure monitoring and positive response in any of the NPH symptoms following large volume CSF drainage.
Forty-two INPH patients underwent neurocognitive testing and Folstein Mini-Mental State Examination (MMSE) prior to shunting. Neurocognitive testing or MMSEwere performed at least 3 months after shunt insertion. Significant improvement in a neurocognitive subtest was defined as improvement by one standard deviation (1 SD) for the patient's age, sex and education level. Significant improvement in overall neurocognitive outcome was defined as a 4-point improvement in MMSE or improvement by 1 SD in 50% of the administered neurocognitive subtests. Nonparametric tests were used to assess changes. Predictors of outcome were assessed via logistic regression analysis.
Twenty-two patients (52.3%) showed overall neurocognitive improvement, and significant improvement was seen in tests of verbal memory and psychomotor speed. Predictive analysis showed that patients scoring more than 1 SD below mean at baseline on verbal memory immediate recall were fourfold less likely to show overall cognitive improvement, and sixfold less likely if also associated with visuoconstructional deficit or executive dysfunction. Verbal memory scores at baseline were higher in patients who showed overall cognitive improvement.
Shunting INPH patients on the basis of CSF pressure monitoring and drainage response shows a significant rate of cognitive improvement, and baseline neurocognitive test scores may distinguish patients likely to respond to shunt surgery from those who will not.
In eukaryotic cells, maintenance of cellular ATP stores depends mainly on mitochondrial oxidative phosphorylation (OXPHOS), which in turn requires sufficient cellular oxygenation. The crucial role of ...proper oxygenation for cellular viability is reflected by involvement of several mechanisms, which sense hypoxia and regulate activities of respiratory complexes according to available oxygen concentrations. Here, we focus on mouse nitric oxide-associated protein 1 (mNOA1), which has been identified as an important component of the machinery that adjusts OXPHOS activity to oxygen concentrations. mNOA1 is an evolutionary conserved GTP-binding protein that is involved in the regulation of mitochondrial protein translation and respiration. We found that mNOA1 is located mostly in the mitochondrial matrix from where it interacts with several high molecular mass complexes, most notably with the complex IV of the respiratory chain and the prohibitin complex. Knock-down of mNOA1 impaired enzyme activity I+III, resulting in oxidative stress and eventually cell death. mNOA1 is transcriptionally regulated in an oxygen-sensitive manner. We propose that oxygen-dependent regulation of mNOA1 is instrumental to adjusting OXPHOS activity to oxygen availability, thereby controlling mitochondrial metabolism.
We present structure−activity relationships for 43 inhibitors of 1-deoxyxylulose-5-phosphate (DOXP)-reductoisomerase, derived from protein-based docking, ligand-based 3D QSAR, and a combination of ...both approaches as realized by AFMoC (adaptation of fields for molecular comparison). DOXP-reductoisomerase (DXR) is a key enzyme of the non-mevalonate pathway for isoprenoid building blocks. This target has been characterized as having potential in the treatment of malaria with fosmidomycin, an established DXR inhibitor, presently in clinical trials. As part of an effort to optimize the properties of fosmidomycin, analogues have been synthesized and tested to gain further insights into the primary determinants of structural affinity. These data have been used to create a predictive model for DXR inhibition applying data taken from several DXR X-ray structures. These structures still leave the active fosmidomycin conformation and detailed reaction mechanism undetermined. This together with the small inhibitor data set provides a major challenge for presently available docking programs and 3D QSAR tools. To overcome these difficulties we have applied the AFMoC protocol. AFMoC makes more efficient use of available modeling data by tailoring DrugScore knowledge-based potentials specifically toward a given protein using inhibitor potency data. While 3D QSAR methods achieved valid models which lack predictivity, AFMoC was found to provide superior performance, based both on cross-validation runs as well as for inhibitors not considered in the training set. In particular, AFMoC's ability to gradually transform between generally applicable unadapted interaction fields to case specifically adapted ones proved to be of major importance. Using 50% tailored fields was found to permit the precise prediction of binding affinities for related ligands without losing the capability to estimate the affinities of structurally distinct inhibitors.
Cardiac myosin‐binding protein C (cMyBP‐C) regulates actin‐myosin interaction and thereby cardiac myocyte contraction and relaxation. This physiologic function is regulated by cMyBP‐C ...phosphorylation. In our study, reduced site‐specific cMyBP‐C phosphorylation coincided with increased S‐glutathiolation in ventricular tissue from patients with dilated or ischemic cardiomyopathy compared to nonfailing donors. We used redox proteomics, to identify constitutive and disease‐specific S‐glutathiolation sites in cMyBP‐C in donor and patient samples, respectively. Among those, a cysteine cluster in the vicinity of the regulatory phosphorylation sites within the myosin S2 interaction domain C1‐M‐C2 was identified and showed enhanced S‐glutathiolation in patients. In vitro S‐glutathiolation of recombinant cMyBP‐C C1‐M‐C2 occurred predominantly at Cys249, which attenuated phosphorylation by protein kinases. Exposure to glutathione disulfide induced cMyBP‐C S‐glutathiolation, which functionally decelerated the kinetics of Ca2+‐activated force development in ventricular myocytes from wild‐type, but not those from Mybpc3‐targeted knockout mice. These oxidation events abrogate protein kinase‐mediated phosphorylation of cMyBP‐C and therefore potentially contribute to the reduction of its phosphorylation and the contractile dysfunction observed in human heart failure.—Stathopoulou, K., Wittig, I., Heidler, J., Piasecki, A., Richter, F., Diering, S., van der Velden, J., Buck, F., Donzelli, S., Schröder, E., Wijnker, P. J. M., Voigt, N., Dobrev, D., Sadayappan, S., Eschenhagen, T., Carrier, L., Eaton, P., Cuello, F. S‐glutathiolation impairs phosphoregulation and function of cardiac myosin‐binding protein C in human heart failure. FASEB J. 30, 1849–1864 (2016). www.fasebj.org
The long-term and potential rare side effects of new immunomodulating drugs for the treatment of multiple sclerosis (MS) are often not well known. Spontaneous case report systems of adverse drug ...effects are a valuable source in pharmacovigilance, but have several limitations. Primary data collections within registries allow a comprehensive analysis of potential side effects, but face several challenges. This article will outline the chances and challenges of registry-based adverse event reporting, using the example of the German immunotherapeutic registry REGIMS. REGIMS is an observational, clinical multicenter registry that aims to assess the incidence, type, and consequences of side effects of MS immunotherapies. Patients treated with an approved MS medication are recruited by their physicians during routine visits in hospitals, outpatient clinics, and MS-specialized practices. REGIMS incorporates an electronic physician-based documentation in each center and a paper-based patient documentation, both at baseline and regular follow-up visits. By the end of 2019, 43 REGIMS centers were actively recruiting patients and performing follow-up documentations. The majority of the first 1000 REGIMS patients were female (69.3%), had relapse-remitting MS (89.8%), and were treated with a second-line therapy. During the implementation of REGIMS, several logistic and procedural challenges had to be overcome, which are outlined in this paper. Pharmacovigilance registries such as REGIMS provide high-quality primary data from a specific patient population in a real-world care setting and enable pharmacovigilance research that cannot be carried out using secondary data. Despite the logistic and procedural challenges in establishing a multicenter pharmacovigilance registry in Germany, the advantages outweigh the drawbacks.
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