Interpretation of Post-operative Distal Humerus Radiographs After Internal Fixation: Prediction of Later Loss of Fixation

PURPOSE

Stable fixation of distal humerus fracture fragments is necessary for adequate healing and maintenance of reduction. The purpose of this study was to measure the reliability and accuracy of interpretation of postoperative radiographs to predict which implants will loosen or break after operative treatment of bicolumnar distal humerus fractures. We also addressed agreement among surgeons regarding which fracture fixation will loosen or break and the influence of years in independent practice, location of practice, and so forth.

METHODS

A total of 232 orthopedic residents and surgeons from around the world evaluated 24 anteroposterior and lateral radiographs of distal humerus fractures on a Web-based platform to predict which implants would loosen or break. Agreement among observers was measured using the multi-rater kappa measure.

RESULTS

The sensitivity of prediction of failure of fixation of distal humerus fracture on radiographs was 63%, specificity was 53%, positive predictive value was 36%, the negative predictive value was 78%, and accuracy was 56%. There was fair interobserver agreement (κ = 0.27) regarding predictions of failure of fixation of distal humerus fracture on radiographs. Interobserver variability did not change when assessed for the various subgroups.

CONCLUSIONS

When experienced and skilled surgeons perform fixation of type C distal humerus fracture, the immediate postoperative radiograph is not predictive of fixation failure. Reoperation based on the probability of failure might not be advisable.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic III.

Safety and Clinical Effects of Mesenchymal Stem Cells Secreting Neurotrophic Factor Transplantation in Patients With Amyotrophic Lateral Sclerosis: Results of Phase 1/2 and 2a Clinical Trials

IMPORTANCE

Preclinical studies have shown that neurotrophic growth factors (NTFs) extend the survival of motor neurons in amyotrophic lateral sclerosis (ALS) and that the combined delivery of these neurotrophic factors has a strong synergistic effect. We have developed a culture-based method for inducing mesenchymal stem cells (MSCs) to secrete neurotrophic factors. These MSC-NTF cells have been shown to be protective in several animal models of neurodegenerative diseases.

OBJECTIVE

To determine the safety and possible clinical efficacy of autologous MSC-NTF cells transplantation in patients with ALS.

DESIGN, SETTING, AND PARTICIPANTS

In these open-label proof-of-concept studies, patients with ALS were enrolled between June 2011 and October 2014 at the Hadassah Medical Center in Jerusalem, Israel. All patients were followed up for 3 months before transplantation and 6 months after transplantation. In the phase 1/2 part of the trial, 6 patients with early-stage ALS were injected intramuscularly (IM) and 6 patients with more advanced disease were transplanted intrathecally (IT). In the second stage, a phase 2a dose-escalating study, 14 patients with early-stage ALS received a combined IM and IT transplantation of autologous MSC-NTF cells.

INTERVENTIONS

Patients were administered a single dose of MSC-NTF cells.

MAIN OUTCOMES AND MEASURES

The primary end points of the studies were safety and tolerability of this cell therapy. Secondary end points included the effects of the treatment on various clinical parameters, such as the ALS Functional Rating Scale-Revised score and the respiratory function.

RESULTS

Among the 12 patients in the phase 1/2 trial and the 14 patients in the phase 2a trial aged 20 and 75 years, the treatment was found to be safe and well tolerated over the study follow-up period. Most of the adverse effects were mild and transient, not including any treatment-related serious adverse event. The rate of progression of the forced vital capacity and of the ALS Functional Rating Scale-Revised score in the IT (or IT+IM)-treated patients was reduced (from -5.1% to -1.2%/month percentage predicted forced vital capacity, P < .04 and from -1.2 to 0.6 ALS Functional Rating Scale-Revised points/month, P = .052) during the 6 months following MSC-NTF cell transplantation vs the pretreatment period. Of these patients, 13 (87%) were defined as responders to either ALS Functional Rating Scale-Revised or forced vital capacity, having at least 25% improvement at 6 months after treatment in the slope of progression.

CONCLUSIONS AND RELEVANCE

The results suggest that IT and IM administration of MSC-NTF cells in patients with ALS is safe and provide indications of possible clinical benefits, to be confirmed in upcoming clinical trials.

TRIAL REGISTRATION

clinicaltrials.gov Identifiers: NCT01051882 and NCT01777646.

Amputation in patients with complex regional pain syndrome: a comparative study between amputees and non-amputees with intractable disease

AIMS

Amputation in intractable cases of complex regional pain syndrome (CRPS) remains controversial. The likelihood of recurrent Complex Regional Pain Syndrome (CRPS), residual and phantom limb pain and persistent disability after amputation is poorly described in the literature. The aims of this study were to compare pain, function, depression and quality of life between patients with intractable CRPS who underwent amputation and those in whom amputation was considered but not performed.

PATIENTS AND METHODS

There were 19 patients in each group, with comparable demographic details. The amputated group included 14 men and five women with a mean age of 31 years (sd 12) at the time of CRPS diagnosis. The non-amputated group consisted of 12 men and seven women and their mean age of 36.8 years (sd 8) at CRPS diagnosis. The mean time from CRPS diagnosis to (first) amputation was 5.2 years (sd 4.3) and the mean time from amputation to data collection was 6.6 years (sd 5.8). All participants completed the following questionnaires: Short-Form (SF) 36, Short Form McGill Pain questionnaire (SF-MPQ), Pain Disability Index (PDI), the Beck Depression Inventory (BDI) and a clinical demographic questionnaire.

RESULTS

The amputation group showed consistently better results compared to the non-amputation group in the following parameters: median pain intensity (VAS): 80 (inter-quartile range (IQR) 13 to 92) vs 91 (IQR 85 to 100); p = 0.007; median SF-MPQ score 28 (IQR 9 to 35) vs 35 (IQR 31 to 38), p = 0.025; median PDI: 42 (IQR 11 to 64) vs 58 (IQR 50 to 62), p = 0.031; median BDI: 19 (IQR 5 to 28) vs 27 (IQR 21 to 32), p = 0.061 (borderline significant) and in six of the eight SF-36 domains.

TAKE HOME MESSAGE

Amputation should be considered as a form of treatment for patients with intractable CRPS.

Beneficial effect of levodopa therapy on stooped posture in Parkinson's disease

OBJECTIVE

This study was designated to quantitatively evaluate the effect of levodopa on spinal posture in patients with PD using a computer-assisted handheld SpinalMouse device.

METHODS

Prospective case-study involving 48 patients with definite PD. All patients were recruited between September 2011 and September 2013 and included 22 dopa-naïve, evaluated before and 3 months after initiation of treatment, and 26 patients with response fluctuations studied during the "off" and "on" states. The SpinalMouse instrument, a computer-assisted mechanical hand-held device, designed to noninvasively assess the curvature of the spine was guided along the midline of the vertebral column in upright, full flexion, and full extension positions to objectively assess spinal posture.

RESULTS

In the dopa-naïve patients, spinal incline in the upright position was 12.4±1.2° before and 7.6±1.3° after treatment; p=0.002. Corresponding area-under-the-curve (AUC) values were 131.7±8.0 cm(2) and 87.1±7.3 cm(2); p<0.0001. In the response fluctuations patients, spinal incline was 13.3±1.3° in the "off" and 9.3±1.2° in the "on" period; p=0.015. Corresponding AUC values were 144.6±9.2 cm(2) and 103.1±8.2 cm(2); p<0.0001.

CONCLUSIONS

This is the first study that objectively measured and quantified abnormalities of spinal posture in patients with PD. Findings suggest that levodopa does have a beneficial effect on anterior flexion of the thoracolumbar spine, and thus indicate that the disorder of stooped posture in PD is mediated, at least in part, by dopamine deficiency.

Perspective: Identification of genetic variants associated with dopaminergic compensatory mechanisms in early Parkinson's disease

Parkinson's disease (PD) is slowly progressive, and heterogeneity of its severity among individuals may be due to endogenous mechanisms that counterbalance the striatal dopamine loss. In this perspective paper, we introduce a neuroimaging-genetic approach to identify genetic variants, which may contribute to this compensation. First, we briefly review current known potential compensatory mechanisms for premotor and early disease PD, located in the striatum and other brain regions. Then, we claim that a mismatch between mild symptomatic disease, manifested by low motor score on the Unified PD Rating Scale (UPDRS), and extensive Nigro-Striatal (NS) degeneration, manifested by reduced uptake of [¹²³I]FP-CIT, is indicative of compensatory processes. If genetic variants are associated with the severity of motor symptoms, while the level of striatal terminals degeneration measured by ligand uptake is taken into account and controlled in the analysis, then these variants may be involved in functional compensatory mechanisms for striatal dopamine deficit. To demonstrate feasibility of this approach, we performed a small “proof of concept” study (candidate gene design) in a sample of 28 Jewish PD patients, and preliminary results are presented.

Knocking out DJ-1 attenuates astrocytes neuroprotection against 6-hydroxydopamine toxicity

Astrocytes are the most abundant glial cell type in the brain. Impairment in astrocyte functions can critically influence neuronal survival and leads to neurodegeneration. Parkinson's disease (PD) is a common neurodegenerative disorder, characterized by motor dysfunction that results from progressive neuronal loss. Astrocytic dysfunction was demonstrated in human samples and in experimental models of PD. Mutations in DJ-1 (PARK7) leading to loss of functional protein cause familial PD and enhance sensitivity to oxidative insults. Recently, an increase in DJ-1's expression was found in reactive astrocytes in various neurodegenerative disorders. Here we show that lack of DJ-1 attenuates astrocytes' ability to support neuronal cells, thereby leading to accelerated neuronal damage. DJ-1 knockout mice demonstrated increased vulnerability in vivo to 6-hydroxydopamine (6-OHDA) hemiparkinsonian PD model. Astrocytes isolated from DJ-1 knockout mice showed an inferior ability to protect human neuroblastoma cells against 6-OHDA insult both by co-culture and through their conditioned media, as compared to wild-type astrocytes. DJ-1 knockout astrocytes showed blunted ability to increase the expression of cellular protective mechanisms against oxidative stress mediated via Nrf-2 and HO-1 in response to exposure to 6-OHDA. These experiments demonstrated that lack of DJ-1 impairs astrocyte-mediated neuroprotection.

The natural history of multiple system atrophy: a prospective European cohort study

BACKGROUND

Multiple system atrophy (MSA) is a fatal and still poorly understood degenerative movement disorder that is characterised by autonomic failure, cerebellar ataxia, and parkinsonism in various combinations. Here we present the final analysis of a prospective multicentre study by the European MSA Study Group to investigate the natural history of MSA.

METHODS

Patients with a clinical diagnosis of MSA were recruited and followed up clinically for 2 years. Vital status was ascertained 2 years after study completion. Disease progression was assessed using the unified MSA rating scale (UMSARS), a disease-specific questionnaire that enables the semiquantitative rating of autonomic and motor impairment in patients with MSA. Additional rating methods were applied to grade global disease severity, autonomic symptoms, and quality of life. Survival was calculated using a Kaplan-Meier analysis and predictors were identified in a Cox regression model. Group differences were analysed by parametric tests and non-parametric tests as appropriate. Sample size estimates were calculated using a paired two-group t test.

FINDINGS

141 patients with moderately severe disease fulfilled the consensus criteria for MSA. Mean age at symptom onset was 56·2 (SD 8·4) years. Median survival from symptom onset as determined by Kaplan-Meier analysis was 9·8 years (95% CI 8·1-11·4). The parkinsonian variant of MSA (hazard ratio [HR] 2·08, 95% CI 1·09-3·97; p=0·026) and incomplete bladder emptying (HR 2·10, 1·02-4·30; p=0·044) predicted shorter survival. 24-month progression rates of UMSARS activities of daily living, motor examination, and total scores were 49% (9·4 [SD 5·9]), 74% (12·9 [8·5]), and 57% (21·9 [11·9]), respectively, relative to baseline scores. Autonomic symptom scores progressed throughout the follow-up. Shorter symptom duration at baseline (OR 0·68, 0·5-0·9; p=0·006) and absent levodopa response (OR 3·4, 1·1-10·2; p=0·03) predicted rapid UMSARS progression. Sample size estimation showed that an interventional trial with 258 patients (129 per group) would be able to detect a 30% effect size in 1-year UMSARS motor examination decline rates at 80% power.

INTERPRETATION

Our prospective dataset provides new insights into the evolution of MSA based on a follow-up period that exceeds that of previous studies. It also represents a useful resource for patient counselling and planning of multicentre trials.

DJ-1 protects against dopamine toxicity: implications for Parkinson's disease and aging

Parkinson's disease (PD) is a common age-related neurodegenerative disorder. Dopamine neurotoxicity, mediated through oxidative stress, is implicated in disease pathogenesis. The vesicular monoamine transporter-2 (VMAT2) transfers dopamine into synaptic vesicles preparing it for exocytotic release and preventing its cytoplasmic oxidation. DJ-1 mutations cause early-onset familial PD. Here, we show that DJ-1 protects dopaminergic neurons and controls the vesicular sequestration of dopamine by upregulating VMAT2. Overexpression of DJ-1 protected cells against dopamine toxicity, reduced oxidative stress, and increased VMAT2 expression and function. Reduced DJ-1 levels resulted in opposite effects. Dopamine vesicular sequestration and its release upon depolarization were dependent on DJ-1 levels. Transcriptional regulation of VMAT2 expression by DJ-1 was confirmed by chromatin immunoprecipitation assay. The results were corroborated in vivo using 6-hydroxydopamine hemiparkinsonian mouse model and transgenic DJ-1 knockout mice. Our experimental data point to a novel potential protective function of DJ-1, which could be used as a therapeutic tool.

Wnt signaling enhances neurogenesis and improves neurological function after focal ischemic injury

Stroke potently stimulates cell proliferation in the subventricular zone of the lateral ventricles with subsequent neuroblast migration to the injured striatum and cortex. However, most of the cells do not survive and mature. Extracellular Wnt proteins promote adult neurogenesis in the neurogenic niches. The aim of the study was to examine the efficacy of Wnt signaling on neurogenesis and functional outcome after focal ischemic injury. Lentivirus expressing Wnt3a-HA (LV-Wnt3a-HA) or GFP (LV-GFP) was injected into the striatum or subventricular zone of mice. Five days later, focal ischemic injury was induced by injection of the vasoconstrictor endothelin-1 into the striatum of the same hemisphere. Treatment with LV-Wnt3a-HA into the striatum significantly enhanced functional recovery after ischemic injury and increased the number of BrdU-positive cells that differentiated into mature neurons in the ischemic striatum by day 28. Treatment with LV-Wnt3a-HA into the subventricular zone significantly enhanced functional recovery from the second day after injury and increased the number of immature neurons in the striatum and subventricular zone. This was accompanied by reduced dissemination of the neuronal injury. Our data indicate that Wnt signaling appears to contribute to functional recovery after ischemic injury by increasing neurogenesis or neuronal survival in the striatum.

Transplantation of placenta-derived mesenchymal stem cells in the EAE mouse model of MS

Stem cell-based regenerative medicine raises great hope for the treatment of multiple sclerosis (MS). Bone marrow-derived mesenchymal stem cells (BM-MSCs) are being tested in clinical trials. Bone marrow is the traditional source of human MSCs, but human term placenta appears to be an excellent alternative because of its availability, without ethical issues. In this study, the therapeutic effect of human placental MSCs (PL-MSCs) was evaluated in experimental autoimmune encephalomyelitis (EAE), the mice model of MS. EAE mice were transplanted intra-cerebrally with PL-MSCs or with the vehicle saline 5 or 10 days after first MOG injection. The mice were monitored for a month after therapy. A daily EAE score revealed a decrease in disease severity in the transplanted animals when compared to saline. Survival was significantly higher in the transplanted animals. In vitro experiments demonstrated that conditioned media from LPS-activated astrocytes stimulated PL-MSCs to express the gene TNF-α-stimulated gene/protein 6 (TSG-6). The same mRNA expression was obtained when PL-MSCs were exposed to TNF-α or IL1-β. These results demonstrate that PL-MSCs have a therapeutic effect in the EAE mice model. We assume that this effect is caused by reduction of the anti-inflammatory protein, TSG-6, of the inflammatory damage.

Therapeutic effect of myogenic cells modified to express neurotrophic factors in a rat model of sciatic nerve injury

Sciatic nerve injury may cause neurological deficits, particularly muscle weakness. Previous studies have shown that administration of neurotrophic factors (NTFs), naturally occurring proteins that support the development and survival of neurons, partially protected the damaged motor neuron in the injured sciatic nerve. In the current study, we have examined whether the administration of various combinations of transfected muscle progenitor cells (MPCs) populations, each expressing a single NTF (BDNF, GDNF, IGF-1 or VEGF) or conditioned media of such culture are capable of rescuing motor neurons in culture or in vivo. We have found that the mixture of conditioned media collected from cultured myogenic cells (MPCs- MIX⁺) alleviated the toxic effect of exposure of the motor neuron cell line NSC34 to hypoxic environment. Furthermore, NTFs secreting cells transplantation, protected motor neurons in a unilateral rat sciatic nerve injury model: One day after the crush, rats underwent transplantation at the lesion site with rat myogenic cells expressing one of the four NTFs; a mixture of cells expressing all four NTFs (MPCs- MIX⁺), MPCs-GFP or PBS. We found that in rats injected with MPCs- MIX⁺ the motor function was markedly preserved, compared to groups injected with cells secreting a single NTF, GFP or PBS. Transplantation of the MPCs- MIX⁺ significantly inhibited the degeneration of the neuromuscular junctions and enhanced the survival of the myelinated motor axons. The injection of MPCs- MIX⁺ preserved the compound muscle action potential (CMAP) as was demonstrated by motor nerve conduction studies. Our findings suggest that MPCs induced to secrete several NTFs can synergistically alleviate symptoms of sciatic nerve injury and perhaps other motor neuron disorders..

Contribution of genetic variants to pain susceptibility in Parkinson disease

BACKGROUND

Pain is a one of the most disturbing non-motor symptoms of Parkinson disease (PD). The susceptibility to pain varies substantially among patients with PD. The aim of this study was to assess a potential association of genetic variants to PD-related pain.

METHODS

We analysed 20 candidate SNPs from 12 genes previously reported to be associated with various pain phenotypes in a homogeneous group of 229 Israeli Jewish PD patients, with and without pain (n = 165 and 64, respectively).

RESULTS

The statistical analysis accounted for the potential influence of demographic and clinical factors. The non-synonymous rs6746030 single nucleotide polymorphism (SNP) of the SCN9A gene, which alters the coding sequence of the sodium channel Nav1.7 (arginine to tryptophan), was nominally associated with PD-related pain susceptibility (p = 0.037), as well as with central and musculoskeletal pain subtypes independently. The synonymous rs324419 SNP of the FAAH gene which encodes fatty acid amide hydrolase, a cannabinoid metabolizing enzyme, was associated with PD-related pain (p = 0.006) and specifically with the musculoskeletal subtype. The FAAH haplotype of rs324419 and rs2295633 SNPs, which was previously associated with the variability in pain response in humans, was also associated with PD-related pain (p = 0.012) and specifically with PD-related musculoskeletal pain.

CONCLUSIONS

Variants within in the SCN9A and FAAH genes were associated with the risk of pain in PD patients. These findings may contribute to our understanding of pain mechanisms of PD and to direct future therapies.

Cell replacement therapy for Parkinson's disease: how close are we to the clinic?

Cell replacement therapy (CRT) offers great promise as the future of regenerative medicine in Parkinson´s disease (PD). Three decades of experiments have accumulated a wealth of knowledge regarding the replacement of dying neurons by new and healthy dopaminergic neurons transplanted into the brains of animal models and affected patients. The first clinical trials provided the proof of principle for CRT in PD. In these experiments, intrastriatal transplantation of human embryonic mesencephalic tissue reinnervated the striatum, restored dopamine levels and showed motor improvements. Sequential controlled studies highlighted several problems that should be addressed prior to the wide application of CRT for PD patients. Moreover, owing to ethical and practical problems, embryonic stem cells require replacement by better-suited stem cells. Several obstacles remain to be surpassed, including identifying the best source of stem cells for A9 dopaminergic neuron generation, eliminating the risk of tumor formation and the development of graft-induced dyskinesias, and standardizing dopaminergic cell production in order to enable clinical application. In this article, we present an update on CRT for PD, reviewing the research milestones, various stem cells used and tailored differentiation methods, and analyze the information gained from the clinical trials.

Differentiated mesenchymal stem cells for sciatic nerve injury

Sciatic nerve injury is common and may cause neurological deficits. Previous studies showed that administration of neurotrophic factors (NTFs), naturally occurring proteins that support the development and survival of neurons, preserved and protected damaged motor neuron in the injured sciatic nerve. We have been successful in converting bone marrow-derived mesenchymal stem cells into astrocyte-like cells that produce and secrete NTFs (NTF(+) cells). These cells demonstrate typical astrocyte morphology, express characteristic astrocyte markers and secrete high levels of NTFs. We have already shown that these cells and their conditioned media can protect neurons in culture and in animal models of neurodegenerative diseases. In the current study we examined whether NTF(+) cells are capable of rescuing motor neurons in a rat sciatic nerve injury model, where the right hind limb sciatic nerve was crushed. Rats were transplanted with NTF(+) cells, MSCs or PBS into the lesion site. In rats injected with the NTF(+) cells motor function was markedly preserved. Moreover, NTF(+) cells significantly inhibited the degeneration of the neuromuscular junctions and preserved the myelinated motor axons. Our findings suggest that autologous therapeutic approach can alleviate signs of sciatic nerve injury and probably other neurological disorders.

Placental mesenchymal stromal cells induced into neurotrophic factor-producing cells protect neuronal cells from hypoxia and oxidative stress

BACKGROUND AIMS

Mesenchymal stromal cells (MSC) may be useful in a range of clinical applications. The placenta has been suggested as an abundant, ethically acceptable, less immunogenic and easily accessible source of MSC. The aim of this study was to evaluate the capacity of induced placental MSC to differentiate into neurotrophic factor-producing cells (NTF) and their protective effect on neuronal cells.

METHODS

MSC were isolated from placentas and characterized by fluorescence-activated cell sorting (FACS). The cells underwent an induction protocol to differentiate them into NTF. Analysis of the cellular differentiation was done using polymerase chain reactions (PCR), immunocytochemical staining and enzyme-linked immunosorbent assays (ELISA). Conditioned media from placental MSC (PL-MSC) and differentiated MSC (PL-DIFF) were collected and examined for their ability to protect neural cells.

RESULTS

The immunocytochemical studies showed that the cells displayed typical MSC membrane markers. The cells differentiated into osteoblasts and adipocytes. PCR and immunohistology staining demonstrated that the induced cells expressed typical astrocytes markers and neurotrophic factors. Vascular endothelial growth factor (VEGF) levels were higher in the conditioned media from PL-DIFF compared with PL-MSC, as indicated by ELISA. Both PL-DIFF and PL-MSC conditioned media markedly protected neural cells from oxidative stress induced by H(2)O(2) and 6-hydroxydopamine. PL-DIFF conditioned medium had a superior effect on neuronal cell survival. Anti-VEGF antibodies (Bevacizumab) reduced the protective effect of the conditioned media from differentiated and undifferentiated MSC.

CONCLUSIONS

This study has demonstrated a neuroprotective effect of MSC of placental origin subjected to an induction differentiation protocol. These data offer the prospect of using placenta as a source for stem cell-based therapies.

Mesenchymal stem cells stimulate endogenous neurogenesis in the subventricular zone of adult mice

Mammalian neurogenesis has been demonstrated in the subventricular zone (SVZ) of the lateral ventricles and the subgranular zone (SGZ) of the dentate gyrus in the hippocampus. However, the low rate and the restricted long term survival of newborn cells limit the restorative ability of this process. Adult bone marrow derived mesenchymal stem cells (MSCs) have been extensively studied due to their wide therapeutic potential. The aim of this study was to determine if MSC transplantation to the normally restrictive SVZ of mice housed in an enriched environment stimulates endogenous neurogenesis. In the presented study 30 C57BL/6 female mice were divided into 3 groups: standard environment injected with phosphate buffered saline (PBS) and enriched environment injected with either PBS or MSCs. Bromodeoxyuridine was injected for 6 days, and 3 weeks later the mice were sacrificed and the brain tissue analyzed immunohistochemically. PBS-treated mice housed in enriched cages showed augmented neurogenesis in the SGZ but not the SVZ. MSC transplantation was associated with increased proliferation and neuronal differentiation of neural progenitors within the SVZ and an increase in the proportion of the newborn neurons out of the total proliferating cells. Histological analysis confirmed the survival of a significant amount of the transplanted cells at least 3 weeks after transplantation, and the presence of brain-derived neurotrophic factor expression. To our knowledge, this is the first study to show that MSCs might interfere with the tight regulation of the SVZ, independent of the induced brain lesion.

VPS35 mutations in Parkinson disease

The identification of genetic causes for Mendelian disorders has been based on the collection of multi-incident families, linkage analysis, and sequencing of genes in candidate intervals. This study describes the application of next-generation sequencing technologies to a Swiss kindred presenting with autosomal-dominant, late-onset Parkinson disease (PD). The family has tremor-predominant dopa-responsive parkinsonism with a mean onset of 50.6 ± 7.3 years. Exome analysis suggests that an aspartic-acid-to-asparagine mutation within vacuolar protein sorting 35 (VPS35 c.1858G>A; p.Asp620Asn) is the genetic determinant of disease. VPS35 is a central component of the retromer cargo-recognition complex, is critical for endosome-trans-golgi trafficking and membrane-protein recycling, and is evolutionarily highly conserved. VPS35 c.1858G>A was found in all affected members of the Swiss kindred and in three more families and one patient with sporadic PD, but it was not observed in 3,309 controls. Further sequencing of familial affected probands revealed only one other missense variant, VPS35 c.946C>T; (p.Pro316Ser), in a pedigree with one unaffected and two affected carriers, and thus the pathogenicity of this mutation remains uncertain. Retromer-mediated sorting and transport is best characterized for acid hydrolase receptors. However, the complex has many types of cargo and is involved in a diverse array of biologic pathways from developmental Wnt signaling to lysosome biogenesis. Our study implicates disruption of VPS35 and retromer-mediated trans-membrane protein sorting, rescue, and recycling in the neurodegenerative process leading to PD.

A double-blind, delayed-start trial of rasagiline in Parkinson's disease (the ADAGIO study): prespecified and post-hoc analyses of the need for additional therapies, changes in UPDRS scores, and non-motor outcomes

BACKGROUND

The ADAGIO study investigated whether rasagiline has disease-modifying effects in Parkinson's disease. Rasagiline 1 mg per day, but not 2 mg per day, was shown to be efficacious in the primary analysis. Here, we report additional secondary and post-hoc analyses of the ADAGIO study.

METHODS

ADAGIO was a placebo-controlled, double-blind, multicentre, delayed-start study, in which 1176 patients with untreated early Parkinson's disease were randomly assigned to receive rasagiline 1 mg or 2 mg per day for 72 weeks (early-start groups) or placebo for 36 weeks followed by rasagiline 1 mg or 2 mg per day for 36 weeks (delayed-start groups). We assessed the need for additional antiparkinsonian therapy and changes in non-motor experiences of daily living and fatigue scales (prespecified outcomes) and changes in unified Parkinson's disease rating scale (UPDRS) scores and subscores in placebo and active groups (post-hoc outcomes). The ADAGIO study is registered with ClinicalTrials.gov, number NCT00256204.

FINDINGS

The need for additional antiparkinsonian therapy was reduced with rasagiline 1 mg (25 of 288 [9%] patients) and 2 mg (26 of 293 [9%]) versus placebo (108 of 593 [18%]; odds ratio for 1 mg rasagiline vs placebo 0·41, 95% CI 0·25-0·65, p=0·0002; 2 mg rasagiline vs placebo 0·41, 0·26-0·64, p=0·0001). At week 36, both doses significantly improved UPDRS motor subscores compared with placebo (1 mg rasagiline mean difference -1·88 [SE 0·35]; 2 mg rasagiline -2·18 [0·35]; both p<0·0001) and activities of daily living subscores (ADL; 1 mg rasagiline -0·86 [0·18]; 2 mg rasagiline -0·88 [0·18]; both p<0·0001), and 1 mg rasagiline significantly improved UPDRS mentation subscore (-0·22 [0·08]; p=0·004). At week 72, the only significant difference between early-start and delayed-start groups was for ADL subscore with the 1 mg dose (-0·62 [0·29]; p=0·035). When assessed for the effect on non-motor symptoms at week 36, both doses showed benefits on the Parkinson fatigue scale versus placebo (1 mg rasagiline mean difference -0·14 [SE 0·05], p=0·0032; 2 mg rasagiline -0·19 [0·05], p<0·0001), and the 1 mg dose showed benefits on the scale for non-motor experiences of daily living compared with placebo (mean difference -0·33 [0·17]; p=0·049). The rate of progression of total UPDRS score for patients in the placebo group was 4·3 points [SE 0·3] over 36 weeks, with extrapolation to about 6 units per year. In the placebo group, patients with the lowest quartile of baseline UPDRS scores (≤14; n=160) progressed more slowly than did those with highest scores (>25·5; n=145; mean difference -3·46 [SE 0·77]; p<0·0001).

INTERPRETATION

These findings show that rasagiline delayed the need for symptomatic antiparkinsonian drugs and emphasise the contribution of the UPDRS ADL in the response of the rasagiline 1 mg per day early-start versus delayed-start group. The rate of UPDRS deterioration was less than was anticipated from previous studies and correlated with baseline severity. Understanding of the pattern of UPDRS deterioration is essential to assess disease modification.

FUNDING

Teva Pharmaceutical Industries and H Lundbeck A/S.

High prevalence of malignant melanoma in Israeli patients with Parkinson's disease

The risk of melanoma is higher in patients with Parkinson's disease (PD) than in the general population. Whether the association is disease related or treatment related is unclear. The objective of this study was to assess melanoma prevalence in PD patients in Israel using active dermatologic screening. Consecutive patients with idiopathic PD were recruited by 12 Israeli centers. A movement disorder specialist assessed the severity of PD and obtained a medical, neurological, and medication history. Subsequently, a dermatologist assessed melanoma risk factors, recorded a dermatologic history, proactively performed a whole-body skin examination, and biopsied suspicious skin lesions. Of the enrolled patients (n = 1,395, mean age 69.5 ± 10.6 years, mean PD duration 7.3 ± 6.0 years), 95.3% were treated with dopaminergic agents. Biopsies revealed 8 patients with melanoma in situ and 1 with invasive malignant melanoma; 14 patients reported a melanoma prior to enrollment. The observed 5-year limited duration prevalence of melanoma in PD patients was 4.4 times greater (95% CI 2.6-7.6) than expected from melanoma prevalence in an age- and sex-matched cohort from the Israel National Cancer Registry. The increase was accounted for by an elevated prevalence of melanoma in situ [relative risk 12.5 (95% CI 6.7-23.2)]. Occurrence of melanoma did not correlate with levodopa therapy or time of onset of PD. Melanoma prevalence in PD patients was higher than expected in the general Israeli population. This was not related to levodopa treatment. PD patients should be actively screened for melanoma on a routine basis.

Wnt signaling pathway overcomes the disruption of neuronal differentiation of neural progenitor cells induced by oligomeric amyloid β-peptide

Neural stem cells give rise to new hippocampal neurons throughout adulthood. Defects in neurogenesis are associated with cognitive dysfunctions, such as Alzheimer disease (AD). Our understanding of the signals controlling this process is limited. The present in vitro study explored the manner in which the Wnt signaling pathway regulates the differentiation of hippocampal progenitors (HPs) into neurons under the influence of amyloid β(42) (Aβ(42) ). The results showed that oligomeric Aβ(42) reduced neuronal differentiation. This process was accompanied by a reduction in active β-catenin levels and proneural gene expression. The addition of Wnt3a increased the neuronal differentiation of Aβ(42) -treated HPs, at the expense of astrocyte differentiation. The effect of Wnt signaling was attributable to progenitor cell differentiation to the neuronal lineage, and not to increased proliferation or rescue of neurons. The interruption of Wnt signaling by oligomeric Aβ(42) may have clinical implications for the treatment of impaired neurogenesis in AD.

Intravitreal injections of neurotrophic factors secreting mesenchymal stem cells are neuroprotective in rat eyes following optic nerve transection

PURPOSE

To evaluate the neuroprotective effect of intravitreal injections of neurotrophic factors secreting mesenchymal stem cells (NTF-SCs) on the survival of retinal ganglion cells (RGCs) in rat eyes after optic nerve transection (ONT).

METHODS

Rat and human bone marrow-derived mesenchymal stem cells (MSCs) were induced to secrete high levels of NTF. The neuroprotective effect from intravitreally injected untreated MSCs or NTF-SCs was compared with that from PBS injections using an ONT model in 146 rats. RGCs were labeled by applying rhodamine dextran to the orbital optic nerve or by injecting Fluorogold into the superior colliculus. Cell- and saline-treated eyes were compared 8 days after ONT. For tracking, MSCs and NTF-SCs were labeled with PKH26 and analyzed at 2 hours and at 10, 17, and 24 days using immunohistochemistry and RT-PCR.

RESULTS

Mean RGC survival at 8 days after transection increased significantly after intravitreal injections of human NTF-SCs (69% ± 3%) or of untreated human MSCs (66% ± 5%) versus PBS (46% ± 3%; P = 0.0005 and P = 0.03, respectively). In an additional set of experiments, human NTF-SCs versus PBS were significantly neuroprotective, but bone marrow-derived rat NTF-SCs were not (P = 0.001 and P = 0.1, respectively). Immunohistochemistry demonstrated that human-derived MSCs, human NTF-SCs, and rat-derived NTF-SCs survived at least 24 days after intravitreal injection.

CONCLUSIONS

Bone marrow-derived MSCs can deliver NTFs by intravitreal injection and can be neuroprotective after ONT. This approach might be further studied to deliver NTFs by autotransplantation in glaucomatous eyes.

Recent advances in amyotrophic lateral sclerosis research: perspectives for personalized clinical application

Treatment of amyotrophic lateral sclerosis (ALS) has been fueled, in part, by frustration over the shortcomings of the symptomatic drugs available, since these do not impede the progression of this disease. Currently, over 150 different potential therapeutic agents or strategies have been tested in preclinical models of ALS. Unfortunately, therapeutic modifiers of murine ALS have failed to be successfully translated into strategies for patients, probably because of differences in pharmacokinetics of the therapeutic agents, route of delivery, inefficiency of the agents to affect the distinct pathologies of the disease or inherent limitations of the available animal models. Given the multiplicity of the pathological mechanisms implicated in ALS, new therapies should consider the simultaneous manipulation of multiple targets. Additionally, a better management of ALS therapy should include understanding the interactions between potential risk factors, biomarkers and heterogeneous clinical features of the patients, aiming to manage their adverse events or personalize the safety profile of these agents. This review will discuss novel pharmacological approaches concerning adjusted therapy for ALS patients: iron-binding brain permeable multimodal compounds, genetic manipulation and cell-based treatment.

Introducing transcription factors to multipotent mesenchymal stem cells: making transdifferentiation possible

Multipotent mesenchymal stem cells (MSCs) represent a promising autologous source for regenerative medicine. Because MSCs can be isolated from adult tissues, they represent an attractive cell source for autologous transplantation. A straightforward therapeutic strategy in the field of stem cell-based regenerative medicine is the transplantation of functional differentiated cells as cell replacement for the lost or defective cells affected by disease. However, this strategy requires the capacity to regulate stem cell differentiation toward the desired cell fate. This therapeutic approach assumes the capability to direct MSC differentiation toward diverse cell fates, including those outside the mesenchymal lineage, a process termed transdifferentiation. The capacity of MSCs to undergo functional transdifferentiation has been questioned over the years. Nonetheless, recent studies support that genetic manipulation can serve to promote transdifferentiation. Specifically, forced expression of certain transcription factors can lead to reprogramming and alter cell fate. Using such a method, fully differentiated lymphocytes have been reprogrammed to become macrophages and, remarkably, somatic cells have been reprogrammed to become embryonic stem-like cells. In this review, we discuss the past and current research aimed at transdifferentiating MSCs, a process with applications that could revolutionize regenerative medicine.

Longitudinal MRI and MRSI characterization of the quinolinic acid rat model for excitotoxicity: peculiar apparent diffusion coefficients and recovery of N-acetyl aspartate levels

Quinolinic acid (QA) induced striatal lesion is an important model for excitotoxicity that is also used for efficacy studies. To date, the morphological and spectroscopic indices of this model have not been studied longitudinally by MRI; therefore the objectives of this study were aimed at following the lesion progression and changes in N-acetyl aspartate (NAA) as viewed by MRI and MRSI, respectively, in-vivo over a period of 49 days. We found that the affected areas exhibited both high and low apparent diffusion coefficients (ADC) even 49 days post QA injection in three of the six tested animals. MRI-guided histological analysis correlated areas characterized by high ADCs on day 49 with cellular loss, while areas characterized by lower ADCs were correlated with macrophage infiltration (CD68 positive stain). Our MRSI study revealed an initial reduction of NAA levels in the lesioned striatum, which significantly recovered with time, although not to control levels. Total-striatum normalized NAA levels recovered from 0.67 +/- 0.15 (of the contralateral row) on day 1 to 0.90 +/- 0.12 on day 49. Our findings suggest that NAA should be considered as a marker for neuronal dysfunction, in addition to neuronal viability. Some behavioral indices could be correlated to permanent neuronal damage while others demonstrated a spontaneous recovery parallel to the NAA recovery. Our findings may have implications in efficacy-oriented studies performed on the QA model.

Bone-marrow-derived mesenchymal stem cell therapy for neurodegenerative diseases

BACKGROUND

Stem-cell-based therapy is a promising new approach to handling neurodegenerative diseases. One of the most promising cellular sources is bone-marrow-derived mesenchymal stem cells (MSCs) also termed multipotent stromal cells. MSCs represent an autologous source and are abundant and non-tumorigenic. Additionally, MSCs possess the useful characteristics of homing and chemokine secretion.

OBJECTIVE/METHODS

Since neurodegenerative diseases have many pathological processes in common, a specific therapeutic agent could potentially ameliorate the symptoms of several distinct neurodegenerative diseases. In this review we demonstrate the wide variety of mechanisms by which MSCs can influence neurodegenerative processes.

RESULTS/CONCLUSIONS

The mechanisms by which transplanted MSCs influence neurodegenerative diseases can be broadly classified as cellular replacement or paracrine secretion, with the latter subdivided into trophic factor secretion or immunomodulation by cytokines. Emerging research suggests that genetic manipulations before transplantation could enhance the therapeutic potential of MSCs. Such manipulation could turn the cells into a 'Trojan horse', to deliver specific proteins, or promote reprogramming of the MSCs into the neural lineage. Clinical trials testing MSC-based therapies for familial amyotrophic lateral sclerosis and multiple sclerosis are in progress.

Protective effects of neurotrophic factor-secreting cells in a 6-OHDA rat model of Parkinson disease

Stem cell-based therapy is a promising treatment for neurodegenerative diseases. In our laboratory, a novel protocol has been developed to induce bone marrow-derived mesenchymal stem cells (MSC) into neurotrophic factors- secreting cells (NTF-SC), thus combining stem cell-based therapy with the NTF-based neuroprotection. These cells produce and secrete factors such as brain-derived neurotrophic factor (BDNF) and glial cell-derived neurotrophic factor. Conditioned medium of the NTF-SC that was applied to a neuroblastoma cell line (SH-SY5Y) 1 h before exposure to the neurotoxin 6-hydroxydopamine (6-OHDA) demonstrated marked protection. An efficacy study was conducted on the 6-OHDA-induced lesion, a rat model of Parkinson's disease. The cells, either MSC or NTF-SC, were transplanted on the day of 6-OHDA administration and amphetamine-induced rotations were measured as a primary behavior index. We demonstrated that when transplanted posterior to the 6-OHDA lesion, the NTF-SC ameliorated amphetamine-induced rotations by 45%. HPLC analysis demonstrated that 6-OHDA induced dopamine depletion to a level of 21% compared to the untreated striatum. NTF-SC inhibited dopamine depletion to a level of 72% of the contralateral striatum. Moreover, an MRI study conducted with iron-labeled cells, followed by histological verification, revealed that the engrafted cells migrated toward the lesion. In a histological assessment, we found that the cells induced regeneration in the damaged striatal dopaminergic nerve terminal network. We therefore conclude that the induced MSC have a therapeutic potential for neurodegenerative processes and diseases, both by the NTFs secretion and by the migratory trait toward the diseased tissue.

Intracerebroventricular transplantation of human mesenchymal stem cells induced to secrete neurotrophic factors attenuates clinical symptoms in a mouse model of multiple sclerosis

Stem cell-based therapy holds great potential for future treatment of multiple sclerosis (MS). Bone marrow mesenchymal stem cells (MSCs) were previously reported to ameliorate symptoms in mouse MS models (experimental autoimmune encephalomyelitis, EAE). In this study, we induced MSCs to differentiate in vitro into neurotrophic factor-producing cells (NTFCs). Our main goal was to examine the clinical use of NTFCs on EAE symptoms. The NTFCs and MSCs were transplanted intracerebroventricularly (ICV) to EAE mice. We found that NTFCs transplantations resulted in a delay of symptom onset and increased animal survival. Transplantation of MSCs also exerted a positive effect but to a lesser extent. In vitro analysis demonstrated the NTFCs' capacity to suppress mice immune cells and protect neuronal cells from oxidative insult. Our results indicate that NTFCs-transplanted ICV delay disease symptoms of EAE mice, possibly via neuroprotection and immunomodulation, and may serve as a possible treatment to MS.

A double-blind, delayed-start trial of rasagiline in Parkinson's disease

BACKGROUND

A therapy that slows disease progression is the major unmet need in Parkinson's disease.

METHODS

In this double-blind trial, we examined the possibility that rasagiline has disease-modifying effects in Parkinson's disease. A total of 1176 subjects with untreated Parkinson's disease were randomly assigned to receive rasagiline (at a dose of either 1 mg or 2 mg per day) for 72 weeks (the early-start group) or placebo for 36 weeks followed by rasagiline (at a dose of either 1 mg or 2 mg per day) for 36 weeks (the delayed-start group). To determine a positive result with either dose, the early-start treatment group had to meet each of three hierarchical end points of the primary analysis based on the Unified Parkinson's Disease Rating Scale (UPDRS, a 176-point scale, with higher numbers indicating more severe disease): superiority to placebo in the rate of change in the UPDRS score between weeks 12 and 36, superiority to delayed-start treatment in the change in the score between baseline and week 72, and noninferiority to delayed-start treatment in the rate of change in the score between weeks 48 and 72.

RESULTS

Early-start treatment with rasagiline at a dose of 1 mg per day met all end points in the primary analysis: a smaller mean (+/-SE) increase (rate of worsening) in the UPDRS score between weeks 12 and 36 (0.09+/-0.02 points per week in the early-start group vs. 0.14+/-0.01 points per week in the placebo group, P=0.01), less worsening in the score between baseline and week 72 (2.82+/-0.53 points in the early-start group vs. 4.52+/-0.56 points in the delayed-start group, P=0.02), and noninferiority between the two groups with respect to the rate of change in the UPDRS score between weeks 48 and 72 (0.085+/-0.02 points per week in the early-start group vs. 0.085+/-0.02 points per week in the delayed-start group, P<0.001). All three end points were not met with rasagiline at a dose of 2 mg per day, since the change in the UPDRS score between baseline and week 72 was not significantly different in the two groups (3.47+/-0.50 points in the early-start group and 3.11+/-0.50 points in the delayed-start group, P=0.60).

CONCLUSIONS

Early treatment with rasagiline at a dose of 1 mg per day provided benefits that were consistent with a possible disease-modifying effect, but early treatment with rasagiline at a dose of 2 mg per day did not. Because the two doses were associated with different outcomes, the study results must be interpreted with caution. (ClinicalTrials.gov number, NCT00256204.)

Comparative characterization of bone marrow-derived mesenchymal stromal cells from four different rat strains

BACKGROUND AIMS

Bone marrow (BM) multipotent mesenchymal stromal cells (MSC) hold great potential for cell-based regenerative medicine. Because of the growing use of autologous rat MSC transplantation in various rat models, there is a need to establish minimal criteria for rat MSC characterization independent of the specific strain employed in each study. We aimed to compare the phenotypic and functional traits of BM MSC from the four strains of rats commonly used in research: Fisher, Lewis, Sprague-Dawley and Wistar.

METHODS

Rat MSC were isolated from the BM of the four different rat strains in an identical fashion. Cells were characterized for their cell-surface phenotype in early and late passage. Functional mesenchymal differentiation capacities were examined following adipogenic and osteogenic inductions. Population doubling times were determined across the four strains throughout 10 passages. In vitro proliferation assays of immune cells were conducted following co-culture of spleen cells and MSC of the four different strains.

RESULTS

We found that rat MSC from different strains exhibited similar cell-surface phenotype. Expansion rates and differentiation capacities of the MSC were also similar across the different strains. Co-culture of rat MSC with spleen cells obtained from rats of a different strain did not induce proliferation of immune cells.

CONCLUSIONS

Our findings suggest that BM-derived MSC from different strains share similar characteristics, in contrast to the variations previously described in the characterization of mice MSC from different strains.

Lesions outside the CNS in Parkinson's disease

Parkinson's disease (PD) is not a simple movement disorder induced just by loss of dopaminergic neurons in the substantia nigra pars compacta. Apparently, the substantia nigra is not the only or the first brain region damaged in PD. Moreover, older and recent studies have shown that the degenerative process in PD is much more extensive and affects not only the central nervous system (CNS) but also the peripheral autonomic nervous system and the organs outside the brain that the latter innervates. These include mainly the gastrointestinal tract, the heart, kidneys, urogenital system, and skin. Additional extra-CNS organs that are involved in PD include the eye and the adrenal gland. This article reviews the anatomical, physiological, and clinical features of extracerebral manifestations of PD, and describes their relevance to the etiology and pathogenesis of the disease. It establishes this illness as a systemic CNS and peripheral disorder that warrants new hypotheses regarding its causation and progression.