Subjective recovery from pregnancy-related pelvic girdle pain the first 6 weeks after delivery: a prospective longitudinal cohort study.

PURPOSE: The purpose of this study was to investigate the subjective recovery from pregnancy-related pelvic girdle pain (PGP) during the first 6 weeks after delivery and to detect possible risk factors for a poor recovery. METHODS: The participants were included in this study at the routine ultrasound examination at 18 weeks of pregnancy. The women received a weekly SMS with the question "How many days during the last week has your PGP been bothersome?" The SMS-track from the final 10 weeks of pregnancy and first 6 weeks after delivery were assessed and sorted, based on individual graphs. A total of 130 women who reported PGP during pregnancy and met for clinical examination 6 weeks after delivery were included in the study. RESULTS: In all, 83% of the women experienced substantial recovery from severe or moderate PGP within 6 weeks after delivery. Of these, 44% reported a substantial recovery already within 2 weeks after delivery. More multiparous women, women reporting PGP the year before pregnancy, and women with high pain intensity during pregnancy had a poor recovery. CONCLUSIONS: The prognosis following PGP in pregnancy is good and the majority of women recovered substantially from severe and moderate pregnancy-related PGP within 6 weeks after delivery. For many women, a subjective substantial recovery occurred within 2 weeks after delivery. Predictors for a poor recovery were multiparity, PGP the year before pregnancy and a high pain intensity during pregnancy. These slides can be retrieved under Electronic Supplementary Material.

DJ-1 is a redox sensitive adapter protein for high molecular weight complexes involved in regulation of catecholamine homeostasis.

DJ-1 is an oxidation sensitive protein encoded by the PARK7 gene. Mutations in PARK7 are a rare cause of familial recessive Parkinson's disease (PD), but growing evidence suggests involvement of DJ-1 in idiopathic PD. The key clinical features of PD, rigidity and bradykinesia, result from neurotransmitter imbalance, particularly the catecholamines dopamine (DA) and noradrenaline. We report in human brain and human SH-SY5Y neuroblastoma cell lines that DJ-1 predominantly forms high molecular weight (HMW) complexes that included RNA metabolism proteins hnRNPA1 and PABP1 and the glycolysis enzyme GAPDH. In cell culture models the oxidation status of DJ-1 determined the specific complex composition. RNA sequencing indicated that oxidative changes to DJ-1 were concomitant with changes in mRNA transcripts mainly involved in catecholamine metabolism. Importantly, loss of DJ-1 function upon knock down (KD) or expression of the PD associated form L166P resulted in the absence of HMW DJ-1 complexes. In the KD model, the absence of DJ-1 complexes was accompanied by impairment in catecholamine homeostasis, with significant increases in intracellular DA and noraderenaline levels. These changes in catecholamines could be rescued by re-expression of DJ-1. This catecholamine imbalance may contribute to the particular vulnerability of dopaminergic and noradrenergic neurons to neurodegeneration in PARK7-related PD. Notably, oxidised DJ-1 was significantly decreased in idiopathic PD brain, suggesting altered complex function may also play a role in the more common sporadic form of the disease.

Adding Chiropractic Treatment to Individual Rehabilitation for Persistent Pelvic Girdle Pain 3 to 6 Months After Delivery: A Pilot Randomized Trial.

OBJECTIVE: The purpose of this study was to investigate the feasibility of conducting a study examining the influence of individualized rehabilitation and chiropractic treatment, compared with individualized rehabilitation alone, in women with persistent dominating 1-sided pelvic girdle pain (PGP) 3 to 6 months after delivery. METHODS: Women were recruited from an outpatient clinic at Stavanger University Hospital, Norway and in a private chiropractic clinic in Stavanger. Those with persistent, dominating 1-sided PGP were included in this pilot study. Those who met inclusion criteria were randomized into 2 groups, one group received individualized rehabilitation and chiropractic treatment and the other group women received individualized rehabilitation alone. Treatment was measured for 20 weeks. RESULTS: Of 330 consenting women who were recruited who reported pelvic pain during pregnancy, 68 reported PGP or low back pain, and 63 consented to fill in a questionnaire. Forty-seven women underwent a clinical examination 3 to 6 months after delivery. During the examination, the women were diagnosed into subgroups for PGP. After exclusion of the women with low back pain only, a total of 13 women were diagnosed with dominating 1-sided PGP and thus included in this study. Six were randomized to the individualized rehabilitation and chiropractic treatment group and 5 to the individualized rehabilitation alone group. After 20 weeks of intervention, both groups reported improvement in disability and pain, but not in general health status. No serious or long-lasting adverse events were registered after treatment or training. CONCLUSION: We found that a study of this nature is feasible. However, the conditions of patient recruitment need to be considered carefully. We learned that a trial to investigate the effect of chiropractic treatment for PGP pain should include all subgroups of PGP to reach an acceptable sample size.

Development and validation of prognostic survival models in newly diagnosed Parkinson's disease.

OBJECTIVE: The objective of this study was to develop valid prognostic models to predict mortality, dependency, and "death or dependency" for use in newly diagnosed Parkinson's disease (PD). METHODS: The models were developed in the Parkinsonism Incidence in North-East Scotland study (UK, 198 patients) and validated in the ParkWest study (Norway, 192 patients), cohorts that attempted to identify and follow-up all new PD cases in the study area. Dependency was defined using the Schwab & England scale. We selected variables measured at time of diagnosis to include in the models. Internal validation and external validation were performed by calculating C-statistics (discrimination) and plotting observed versus predicted risk in quantiles of predicted risk (calibration). RESULTS: Older age, male sex, increased severity of axial features, and Charlson comorbidity index were independent prognostic factors in the mortality model. Increasing age, higher smoking history, increased severity of axial features, and lower MMSE score were independent predictors in the models of dependency and "death or dependency." Each model had very good internal calibration and very good or good discrimination (internal and external C-statistics for the models were 0.73-0.75 and 0.68-0.78, respectively). Although each model clearly separated patients into groups according to risk, they tended to overestimate risk in ParkWest. The models were recalibrated to the baseline risk in the ParkWest study and then calibrated well in this cohort. CONCLUSIONS: We have developed prognostic models for predicting medium-term risk of important clinical outcomes in newly diagnosed PD. These models have validity for use for stratification of randomization, confounder adjustment, and case-mix correction, but they are inadequate for individualized prognostication. © 2017. The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Association of glucocerebrosidase polymorphisms and mutations with dementia in incident Parkinson's disease.

INTRODUCTION: Both polymorphisms and mutations in glucocerebrosidase (GBA) may influence the development of dementia in patients with Parkinson's disease. METHODS: Four hundred forty-two patients and 419 controls were followed for 7 years. Dementia was diagnosed using established criteria. Participants were analyzed for GBA genetic variants, including E326K, T369M, and L444P. Associations between GBA carrier status and dementia were assessed with Cox survival analysis. RESULTS: A total of 12.0% of patients with Parkinson's disease carried a GBA variant, and nearly half (22/53) of them progressed to dementia during follow-up. Carriers of deleterious GBA mutations (adjusted hazard ratio 3.81, 95% confidence interval 1.35 to 10.72; P = .011) or polymorphisms (adjusted hazard ratio 1.79; 95% confidence interval 1.07 to 3.00; P = .028) progressed to dementia more rapidly than noncarriers. DISCUSSION: GBA variants are of great clinical relevance for the development of dementia in Parkinson's disease, especially due to the relatively higher frequency of these alleles compared with other risk alleles.

Familial aggregation of Parkinson's disease may affect progression of motor symptoms and dementia.

BACKGROUND: Familial aggregation has been described in PD of both early and late onset, but has not been studied in a true population-based sample. Moreover, little is known about its association with disease progression and endophenotypes. OBJECTIVES: The objectives of this work were to determine familial aggregation of idiopathic PD in a population-based cohort and study the association with clinical endophenotypes and disease progression. METHODS: We examined family history data from the Norwegian ParkWest study, a well-characterized, population-based cohort of incident PD patients and age-matched healthy controls. Family data were collected at baseline with a simplified questionnaire (192 cases and 193 controls) and after 3 years of longitudinal follow-up using an extended questionnaire (172 cases and 171 controls). RESULTS: Compared to the controls, the PD patients had an increased relative risk of having a first-degree relative with PD when using the extended questionnaire (relative risk = 1.988; P = 0.036), but not when using the simplified questionnaire (relative risk = 1.453; P = 0.224). There was no significant difference in age of onset or motor subtype (P = 0.801). However, cases with a family history of PD had reduced progression over 7 years as measured by UPDRS II (P = 0.008) and smaller rate of decrease of MMSE (P = 0.046). CONCLUSIONS: Our findings confirm familial aggregation in a population-based cohort of idiopathic PD. Moreover, we show that positive family history of PD in patients is associated with a slower progression of PD symptoms and cognitive decline. © 2016 International Parkinson and Movement Disorder Society.

Validation of a new assay for α-synuclein detection in cerebrospinal fluid.

BACKGROUND: Abnormal α-synuclein aggregation and deposition is the pathological hallmark of Parkinson's disease (PD) and dementia with Lewy bodies (DLB), but is also found in Alzheimer disease (AD). Therefore, there is a gaining interest in α-synuclein in cerebrospinal fluid (CSF) as potential biomarker for these neurodegenerative diseases. To broaden the available choices of α-synuclein measurement in CSF, we developed and validated a new assay for detecting total α-synuclein. METHODS: This novel ELISA uses commercially available antibodies and is based on electrochemiluminescence technology. The assay protocol is straightforward, with short and simple incubation steps, and requires only small amounts of CSF. We validated this assay for precision, parallelism, dilution linearity, specificity, and spike recovery. We further compared it to the newly validated α-synuclein assay from BioLegend by analyzing a set of 50 CSF samples with both assays. RESULTS: The new assay quantifies α-synuclein in CSF with a lower limit of detection of 36.3 pg/mL and shows no cross-reactivity with human ß- and γ-synuclein. Results of dilution linearity, parallelism, spike recovery, and precision classify this assay as well suited for α-synuclein detection in human CSF samples. CONCLUSIONS: We present a novel assay based on freely available components to quantify total α-synuclein in CSF as an additional method for α-synuclein as a biomarker in neurodegenerative diseases. The assay convinces with its simple and convenient protocol paired with high sensitivity.

Chiropractic management of dominating one-sided pelvic girdle pain in pregnant women; a randomized controlled trial.

BACKGROUND: The aim of this study was to investigate the outcome of chiropractic management for a subgroup of pregnant women with dominating one-sided pelvic girdle pain (PGP). METHODS: The study population was recruited from a prospective longitudinal cohort study of pregnant women. Women reporting pelvic pain (PP), and who were diagnosed with dominating one-sided PGP after a clinical examination, were invited to participate in the intervention study. Recruitment took place either at 18 weeks, or after an SMS-tracking up to week 29. The women were randomized into a treatment group or a control group. The treatment group received chiropractic treatment individualized to each woman with regards to treatment modality and number of treatments. The control group was asked to return to conventional primary health care. The primary outcome measure was new occurrence of full time and/or graded sick leave due to PP and/or low back pain. Secondary outcome measures were self-reported PP, physical disability and general health status. Proportion of women reporting new occurrence of sick leave were compared using Chi squared tests. Differences in secondary outcome measures were estimated using linear regression analyses. RESULTS: Fifty-Six women were recruited, and 28 of them were randomized into the treatment group, and 28 into the control group. There was no statistically significant difference in sick leave, PP, disability or general health status between the two groups during pregnancy or after delivery. CONCLUSION: The study did not demonstrate superiority of chiropractic management over conventional care for dominating one-sided PGP during pregnancy. However, the analyses revealed wide confidence intervals containing both positive and negative clinically relevant effects. TRIAL REGISTRATION: The study was registered in ClinicalTrials.gov ( NCT01098136 ; 22/03/2010).

microRNAs as neuroregulators, biomarkers and therapeutic agents in neurodegenerative diseases.

The last decade has experienced the emergence of microRNAs as a key molecular tool for the diagnosis and prognosis of human diseases. Although the focus has mostly been on cancer, neurodegenerative diseases present an exciting, yet less explored, platform for microRNA research. Several studies have highlighted the significance of microRNAs in neurogenesis and neurodegeneration, and pre-clinical studies have shown the potential of microRNAs as biomarkers. Despite this, no bona fide microRNAs have been identified as true diagnostic or prognostic biomarkers for neurodegenerative disease. This is mainly due to the lack of precisely defined patient cohorts and the variability within and between individual cohorts. However, the discovery that microRNAs exist as stable molecules at detectable levels in body fluids has opened up new avenues for microRNAs as potential biomarker candidates. Furthermore, technological developments in microRNA biology have contributed to the possible design of microRNA-mediated disease intervention strategies. The combination of these advancements, with the availability of well-defined longitudinal patient cohort, promises to not only assist in developing invaluable diagnostic tools for clinicians, but also to increase our overall understanding of the underlying heterogeneity of neurodegenerative diseases. In this review, we present a comprehensive overview of the existing knowledge of microRNAs in neurodegeneration and provide a perspective of the applicability of microRNAs as a basis for future therapeutic intervention strategies.

Impact of exercise programs among helicopter pilots with transient LBP.

BACKGROUND: Flight related low back pain (LBP) among helicopter pilots is frequent and may influence flight performance. Prolonged confined sitting during flights seems to weaken lumbar trunk (LT) muscles with associated secondary transient pain. Aim of the study was to investigate if structured training could improve muscular function and thus improve LBP related to flying. METHODS: 39 helicopter pilots (35 men and 4 women), who reported flying related LBP on at least 1 of 3 missions last month, were allocated to two training programs over a 3-month period. Program A consisted of 10 exercises recommended for general LBP. Program B consisted of 4 exercises designed specifically to improve LT muscular endurance. The pilots were examined before and after the training using questionnaires for pain, function, quality of health and tests of LT muscular endurance as well as ultrasound measurements of the contractility of the lumbar multifidus muscle (LMM). RESULTS: Approximately half of the participants performed the training per-protocol. Participants in this subset group had comparable baseline characteristics as the total study sample. Pre and post analysis of all pilots included, showed participants had marked improvement in endurance and contractility of the LMM following training. Similarly, participants had improvement in function and quality of health. Participants in program B had significant improvement in pain, function and quality of health. CONCLUSIONS: This study indicates that participants who performed a three months exercise program had improved muscle endurance at the end of the program. The helicopter pilots also experienced improved function and quality of health. TRIAL REGISTRATION: Identifier: NCT01788111 Registration date; February 5th, 2013, verified April 2016.

LRRK2 knockdown in zebrafish causes developmental defects, neuronal loss, and synuclein aggregation.

Although mutations in the leucine-rich repeat kinase 2 (LRRK2) gene are the most common cause of genetic Parkinson's disease, their function is largely unknown. LRRK2 is pleiotropic in nature, shown to be involved in neurodegeneration and in more peripheral processes, including kidney functions, in rats and mice. Recent studies in zebrafish have shown conflicting evidence that removal of the LRRK2 WD40 domain may or may not affect dopaminergic neurons and/or locomotion. This study shows that ∼50% LRRK2 knockdown in zebrafish causes not only neuronal loss but also developmental perturbations such as axis curvature defects, ocular abnormalities, and edema in the eyes, lens, and otic vesicles. We further show that LRRK2 knockdown results in significant neuronal loss, including a reduction of dopaminergic neurons. Immunofluorescence demonstrates that endogenous LRRK2 is expressed in the lens, brain, heart, spinal cord, and kidney (pronephros), which mirror the LRRK2 morphant phenotypes observed. LRRK2 knockdown results further in the concomitant upregulation of ß-synuclein, PARK13, and SOD1 and causes ß-synuclein aggregation in the diencephalon, midbrain, hindbrain, and postoptic commissure. LRRK2 knockdown causes mislocalization of the Na(+) /K(+) ATPase protein in the pronephric ducts, suggesting that the edema might be linked to renal malfunction and that LRRK2 might be associated with pronephric duct epithelial cell differentiation. Combined, our study shows that LRRK2 has multifaceted roles in zebrafish and that zebrafish represent a complementary model to further our understanding of this central protein. © 2016 Wiley Periodicals, Inc.

Pelvic girdle pain 3-6 months after delivery in an unselected cohort of Norwegian women.

PURPOSE: Persistent pelvic girdle pain (PGP) after delivery is considered uncommon. The aim of this study was to assess the frequency of persistent PGP after delivery in an unselected population, its influence on the women's daily life, and potential risk factors. METHODS: The study population was drawn from a previous retrospective study of pelvic pain (PP) during pregnancy. The women were followed until 3-6 months after delivery in a prospective cohort study. All women were contacted by telephone and those with persistent PP were invited to fill in questionnaires and undergo a clinical examination. RESULTS: 68 of 330 women reported persistent pain in the pelvic area 3-6 months after delivery. 47 underwent a clinical examination, after which 36 women were diagnosed with either PGP alone (n = 25), or PGP combined with low back pain (LBP) (n = 11). Affected women reported a poor subjective health status, but the pain did not have a major impact on their daily life activities. Women with 3 independent risk factors: age ≥30 years, a moderate or high Oswestry Disability Index in pregnancy, and combined PP and LBP during pregnancy, had a 27-fold increased risk for persistent PGP compared with women without these risk factors. CONCLUSION: 16 % of women that reported PP during pregnancy were found to have persistent PGP 3-6 months after the delivery. Women with risk factors for persistent PGP should be identified while pregnant, and offered a follow-up examination 3 months after delivery.

Long-Term Mortality and Its Risk Factors in Stroke Survivors.

BACKGROUND: Stroke is one of the leading causes of mortality worldwide. Understanding the risk factors associated with stroke mortality is important to improve patient management. Few studies have examined long-term mortality and its associated predictive risk factors. METHODS: We examined long-term mortality in 1137 patients with acute stroke and compared it to a geographically age- and sex-matched, stroke-free control group. We followed the stroke patients for as long as 16.4 years. In 1018 of these patients we assessed the effect of demographic, clinical, and hematological factors on mortality. RESULTS: At the end of the study period, 51.7% of the patients and 32.7% of the stroke-free control individuals had died (hazard ratio 2.2, confidence interval 1.9-2.5, P < .001). A total of 72.5% of the patients and 53% of the controls with 12 years' follow-up (n = 570) had died (P < .001). Regression analyses indicate that, in addition to known risk factors such as age, diabetes, and stroke severity, both low cholesterol (P < .001) and hemoglobin (P < .002), hyperhomocysteinemia (P = .005), and elevated serum creatinine (P < .001) at index stroke are associated with increased long-term mortality. CONCLUSIONS: Stroke patients surviving the first year after stroke have a markedly increased mortality rate as seen in long-term follow-up. Furthermore, the results from this study indicate that changes in creatinine, homocysteine, and hemoglobin should be followed more carefully as standard practice after acute stroke.

Progressive degeneration of dopaminergic neurons through TRP channel-induced cell death.

Progressive neurodegenerative diseases are among the most frequently occurring aging-associated human pathologies. In a screen for Caenorhabditis elegans mutant animals that lack their normal complement of dopaminergic neurons, we identified two strains with progressive loss of dopaminergic neurons during postembryonic life. Through whole-genome sequencing we show that both strains harbor dominant (d), gain-of-function mutations in the Transient Receptor Potential (TRP) mechanosensory channel trp-4, a member of the invertebrate and vertebrate TRPN-type of the TRP family channels. Gain-of-function mutations in TRP channels have not been previously implicated in dopaminergic neuronal degeneration. We show that trp-4(d) induces cell death in dopamine neurons through a defined, calcium-related downstream pathway.

Arabidopsis AtPARK13, which confers thermotolerance, targets misfolded proteins.

Mutations in HTRA2/Omi/PARK13 have been implicated in Parkinson disease (PD). PARK13 is a neuroprotective serine protease; however, little is known about how PARK13 confers stress protection and which protein targets are directly affected by PARK13. We have reported that Arabidopsis thaliana represents a complementary PD model, and here we demonstrate that AtPARK13, similar to human PARK13 (hPARK13), is a mitochondrial protease. We show that the expression/accumulation of AtPARK13 transcripts are induced by heat stress but not by other stress conditions, including oxidative stress and metals. Our data show that elevated levels of AtPARK13 confer thermotolerance in A. thaliana. Increased temperatures accelerate protein unfolding, and we demonstrate that although AtPARK13 can act on native protein substrates, unfolded proteins represent better AtPARK13 substrates. The results further show that AtPARK13 and hPARK13 can degrade the PD proteins α-synuclein (SNCA) and DJ-1/PARK7 directly, without autophagy involvement, and that misfolded SNCA and DJ-1 represent better substrates than their native counterparts. Comparative proteomic profiling revealed AtPARK13-mediated proteome changes, and we identified four proteins that show altered abundance in response to AtPARK13 overexpression and elevated temperatures. Our study not only suggests that AtPARK13 confers thermotolerance by degrading misfolded protein targets, but it also provides new insight into possible roles of this protease in neurodegeneration.

Fine mapping and resequencing of the PARK16 locus in Parkinson's disease.

The PARK16 locus, spanning five genes on chromosome 1, was among the first genetic regions to show genome-wide association in Parkinson's disease (PD). Subsequent investigations have found variability in PARK16 top-hits and association patterns across populations, and the implicated genes and mechanisms are currently unclear. In the present study, we aimed to explore the contribution of PARK16 variability to PD risk in a Scandinavian population. We genotyped 17 single-nucleotide polymorphisms in a case-control sample set of 2570 individuals from Norway and Sweden to fine map the locus. Targeted resequencing of the full coding regions of SLC45A3, NUCKS1, RAB7L1, SLC41A1 and PM20D1 was performed in DNA pools from a subset of 387 patient samples. We find evidence for an association with PD for rs1775143 as well as a haplotype located around the 5' region of RAB7L1, implicating variants which are not in high linkage disequilibrium with the strongest signal from a recent large meta-analysis in Caucasians. We also provide suggestive support for epistasis between RAB7L1 and LRRK2 as previously hypothesized by others. Comparing our results with previous work, allelic heterogeneity at PARK16 appears likely, and further studies are warranted to disentangle the complex patterns of association and pinpoint the functionally relevant variants.

The association between pelvic girdle pain and sick leave during pregnancy; a retrospective study of a Norwegian population.

BACKGROUND: The incidence of pelvic girdle pain (PGP) in pregnancy is wide ranged depending on definition, the utilised diagnostic means, and the design of the studies. PGP during pregnancy has negative effects on activities of daily living and causes long sick leave, which makes it a major public health issue. Our objectives were to explore the frequency of sick leave in pregnancy due to PGP, assess the relationship between different types of pain-related activities of daily living, examine physical workload, type of work in relation to sick leave, and to explore factors that make women less likely to take sick leave for PGP. METHODS: All women giving birth at the maternity ward of Stavanger University Hospital, Norway, were asked to participate and complete a questionnaire on demographic features, PGP, pain-related activities of daily living, sick leave in general and for PGP, frequency of exercising before and during pregnancy. Drawings of pelvic girdle and low back area were used for the localization of pain. PGP intensity was then rated retrospectively on a numerical rating scale. Non-parametric tests, multinomial logistic regression and sequential linear regression analysis were used in the statistical analysis. RESULTS: PGP is a frequent and major cause of sick leave during pregnancy among Norwegian women, which is also reflected in activities of daily living as measured with scores on all Oswestry disability index items. In the multivariate analysis of factors related to sick leave and PGP we found that work satisfaction, problems with lifting and sleeping, and pain intensity were risk factors for sick leave. In addition, women with longer education, higher work satisfaction and fewer problems with sitting, walking and standing, were less likely to take sick leave in pregnancy, despite the same pain intensity as women being on sick leave. CONCLUSIONS: A coping factor in pregnant women with PGP was discovered, most likely dependant on education, associated with work situation and/or work posture, which decreases sick leave. We recommend these issues to be further examined in a prospective longitudinal study since it may have important implications for sick leave frequency during pregnancy.

Parkinson disease protein DJ-1 binds metals and protects against metal-induced cytotoxicity.

The progressive loss of motor control due to reduction of dopamine-producing neurons in the substantia nigra pars compacta and decreased striatal dopamine levels are the classically described features of Parkinson disease (PD). Neuronal damage also progresses to other regions of the brain, and additional non-motor dysfunctions are common. Accumulation of environmental toxins, such as pesticides and metals, are suggested risk factors for the development of typical late onset PD, although genetic factors seem to be substantial in early onset cases. Mutations of DJ-1 are known to cause a form of recessive early onset Parkinson disease, highlighting an important functional role for DJ-1 in early disease prevention. This study identifies human DJ-1 as a metal-binding protein able to evidently bind copper as well as toxic mercury ions in vitro. The study further characterizes the cytoprotective function of DJ-1 and PD-mutated variants of DJ-1 with respect to induced metal cytotoxicity. The results show that expression of DJ-1 enhances the cells' protective mechanisms against induced metal toxicity and that this protection is lost for DJ-1 PD mutations A104T and D149A. The study also shows that oxidation site-mutated DJ-1 C106A retains its ability to protect cells. We also show that concomitant addition of dopamine exposure sensitizes cells to metal-induced cytotoxicity. We also confirm that redox-active dopamine adducts enhance metal-catalyzed oxidation of intracellular proteins in vivo by use of live cell imaging of redox-sensitive S3roGFP. The study indicates that even a small genetic alteration can sensitize cells to metal-induced cell death, a finding that may revive the interest in exogenous factors in the etiology of PD.

PARK13 regulates PINK1 and subcellular relocation patterns under oxidative stress in neurons.

Parkinson's disease (PD) is a progressive and irreversible neurodegenerative disorder coupled to selective degeneration of dopamine-producing neurons in the substantia nigra. The majority of PD incidents are sporadic, but monogenic cases account for 5-10% of cases. Mutations in PINK1 cause autosomal recessive forms of early-onset PD, and PINK1 stimulates Omi/HtrA2/PARK13 protease activity when both proteins act as neuroprotective components in the same stress pathway. Studies on PINK1 and PARK13 have concentrated on phosphorylation-dependent PINK1-mediated activation of PARK13 and mitochondrial functions, because both proteins are classically viewed as mitochondrial. Although PARK13-mediated protective mechanisms are at least in part regulated by PINK1, little is known concerning how these two proteins are regulated in different subcellular compartments or, indeed, the influence of PARK13 on PINK1 characteristics. We show that PARK13 localizes to a variety of subcellular locations in neuronal cells and that PINK1, although more restrictive, also localizes to locations other than those previously reported. We demonstrate that PARK13 accumulation leads to a concomitant accumulation of PINK1 and that the increase in PINK1 levels is compartmental specific, indicating a correlative relationship between the two proteins. Moreover, we show that PARK13 and PINK1 protein levels accumulate in response to H2 O2 and L-DOPA treatments in a subcellular fashion and that both proteins show relocation to the cytoskeleton in response to H2 O2 . This H2 O2 -mediated relocation is abolished by PARK13 overexpression. This study shows that PARK13 and PINK1 are subcellular-specific, but dynamic, proteins with a reciprocal molecular relationship providing new insight into the complexity of PD.