Loss of the glycosyltransferase Galnt11 affects vitamin D homeostasis and bone composition.

O-glycosylation is a conserved posttranslational modification that impacts many aspects of organismal viability and function. Recent studies examining the glycosyltransferase Galnt11 demonstrated that it glycosylates the endocytic receptor megalin in the kidneys, enabling proper binding and reabsorption of ligands, including vitamin D-binding protein (DBP). Galnt11-deficient mice were unable to properly reabsorb DBP from the urine. Vitamin D plays an essential role in mineral homeostasis and its deficiency is associated with bone diseases such as rickets, osteomalacia, and osteoporosis. We therefore set out to examine the effects of the loss of Galnt11 on vitamin D homeostasis and bone composition. We found significantly decreased levels of serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D, consistent with decreased reabsorption of DBP. This was accompanied by a significant reduction in blood calcium levels and a physiologic increase in parathyroid hormone (PTH) in Galnt11-deficient mice. Bones in Galnt11-deficient mice were smaller and displayed a decrease in cortical bone accompanied by an increase in trabecular bone and an increase in a marker of bone formation, consistent with PTH-mediated effects on bone. These results support a unified model for the role of Galnt11 in bone and mineral homeostasis, wherein loss of Galnt11 leads to decreased reabsorption of DBP by megalin, resulting in a cascade of disrupted mineral and bone homeostasis including decreased circulating vitamin D and calcium levels, a physiological increase in PTH, an overall loss of cortical bone, and an increase in trabecular bone. Our study elucidates how defects in O-glycosylation can influence vitamin D and mineral homeostasis and the integrity of the skeletal system.

Polymers with controlled assembly and rigidity made with click-functional peptide bundles.

The engineering of biological molecules is a key concept in the design of highly functional, sophisticated soft materials. Biomolecules exhibit a wide range of functions and structures, including chemical recognition (of enzyme substrates or adhesive ligands1, for instance), exquisite nanostructures (composed of peptides2, proteins3 or nucleic acids4), and unusual mechanical properties (such as silk-like strength3, stiffness5, viscoelasticity6 and resiliency7). Here we combine the computational design of physical (noncovalent) interactions with pathway-dependent, hierarchical 'click' covalent assembly to produce hybrid synthetic peptide-based polymers. The nanometre-scale monomeric units of these polymers are homotetrameric, α-helical bundles of low-molecular-weight peptides. These bundled monomers, or 'bundlemers', can be designed to provide complete control of the stability, size and spatial display of chemical functionalities. The protein-like structure of the bundle allows precise positioning of covalent linkages between the ends of distinct bundlemers, resulting in polymers with interesting and controllable physical characteristics, such as rigid rods, semiflexible or kinked chains, and thermally responsive hydrogel networks. Chain stiffness can be controlled by varying only the linkage. Furthermore, by controlling the amino acid sequence along the bundlemer periphery, we use specific amino acid side chains, including non-natural 'click' chemistry functionalities, to conjugate moieties into a desired pattern, enabling the creation of a wide variety of hybrid nanomaterials.

Quantitative Analysis and Molecular Docking Simulation of Flavonols from Eruca sativa Mill. and Their Effect on Skin Barrier Function.

Eruca sativa is a commonly used edible plant in Italian cuisine. E. sativa 70% ethanol extract (ES) was fractionated with five organic solvents, including n-hexane (EHex), chloroform (ECHCl3), ethyl acetate (EEA), n-butyl alcohol (EBuOH), and water (EDW). Ethyl acetate fraction (EEA) had the highest antioxidant activity, which was correlated with the total polyphenol and flavonoid content. ES and EEA acted as PPAR-α ligands by PPAR-α competitive binding assay. EEA significantly increased cornified envelope formation as a keratinocyte terminal differentiation marker in HaCaT cells. Further, it significantly reduced nitric oxide and pro-inflammatory cytokines (IL-6 and TNF-α) in lipopolysaccharide-stimulated RAW 264.7 cells. The main flavonol forms detected in high amounts from EEA are mono-and di-glycoside of each aglycone. The main flavonol form of EEA is the mono-glycoside of each aglycone detected, and the most abundant flavonol mono-glycoside is kaempferol 3-glucoside 7.4%, followed by quercetin-3-glucoside 2.3% and isorhamnetin 3-glucoside 1.4%. Flavonol mono-glycosides were shown to be a potent PPAR-α ligand using molecular docking simulation and showed the inhibition of nitric oxide. These results suggest that the flavonol composition of E. sativa is suitable for use in improving skin barrier function and inflammation in skin disorders, such as atopic dermatitis.

Clinical correlates of pareidolias and color discrimination deficits in idiopathic REM sleep behavior disorder and Parkinson's disease.

Visuoperceptual dysfunction is common in Parkinson's disease (PD) and is also reported in its prodromal phase, isolated REM sleep behavior disorder (iRBD). We aimed to investigate color discrimination ability and complex visual illusions known as pareidolias in patients with iRBD and PD compared to healthy controls, and their associating clinical factors. 46 iRBD, 43 PD, and 64 healthy controls performed the Farnsworth-Munsell 100 hue test and noise pareidolia tests. Any relationship between those two visual functions and associations with prodromal motor and non-motor manifestations were evaluated, including MDS-UPDRS part I to III, Cross-Cultural Smell Identification Test, sleep questionnaires, and comprehensive neuropsychological assessment. iRBD and PD patients both performed worse on the Farnsworth-Munsell 100 hue test and had greater number of pareidolias compared to healthy controls. No correlations were found between the extent of impaired color discrimination and pareidolia scores in either group. In iRBD patients, pareidolias were associated with frontal executive dysfunction, while impaired color discrimination was associated with visuospatial dysfunction, hyposmia, and higher MDS-UPDRS-III scores. Pareidolias in PD patients correlated with worse global cognition, whereas color discrimination deficits were associated with frontal executive dysfunction. Color discrimination deficits and pareidolias are frequent but does not correlate with each other from prodromal to clinically established stage of PD. The different pattern of clinical associates with the two visual symptoms suggests that evaluation of both color and pareidolias may aid in revealing the course of neurodegeneration in iRBD and PD patients.

Progression of clinical markers in prodromal Parkinson's disease and dementia with Lewy bodies: a multicentre study.

The neurodegenerative synucleinopathies, including Parkinson's disease and dementia with Lewy bodies, are characterized by a typically lengthy prodromal period of progressive subclinical motor and non-motor manifestations. Among these, idiopathic REM sleep behaviour disorder is a powerful early predictor of eventual phenoconversion, and therefore represents a critical opportunity to intervene with neuroprotective therapy. To inform the design of randomized trials, it is essential to study the natural progression of clinical markers during the prodromal stages of disease in order to establish optimal clinical end points. In this study, we combined prospective follow-up data from 28 centres of the International REM Sleep Behavior Disorder Study Group representing 12 countries. Polysomnogram-confirmed REM sleep behaviour disorder subjects were assessed for prodromal Parkinson's disease using the Movement Disorder Society criteria and underwent periodic structured sleep, motor, cognitive, autonomic and olfactory testing. We used linear mixed-effect modelling to estimate annual rates of clinical marker progression stratified by disease subtype, including prodromal Parkinson's disease and prodromal dementia with Lewy bodies. In addition, we calculated sample size requirements to demonstrate slowing of progression under different anticipated treatment effects. Overall, 1160 subjects were followed over an average of 3.3 ± 2.2 years. Among clinical variables assessed continuously, motor variables tended to progress faster and required the lowest sample sizes, ranging from 151 to 560 per group (at 50% drug efficacy and 2-year follow-up). By contrast, cognitive, olfactory and autonomic variables showed modest progression with higher variability, resulting in high sample sizes. The most efficient design was a time-to-event analysis using combined milestones of motor and cognitive decline, estimating 117 per group at 50% drug efficacy and 2-year trial duration. Finally, while phenoconverters showed overall greater progression than non-converters in motor, olfactory, cognitive and certain autonomic markers, the only robust difference in progression between Parkinson's disease and dementia with Lewy bodies phenoconverters was in cognitive testing. This large multicentre study demonstrates the evolution of motor and non-motor manifestations in prodromal synucleinopathy. These findings provide optimized clinical end points and sample size estimates to inform future neuroprotective trials.

Prodromal dementia with Lewy bodies in REM sleep behavior disorder: A multicenter study.

INTRODUCTION: Isolated/idiopathic rapid eye movement sleep behavior disorder (iRBD) is a powerful early predictor of dementia with Lewy bodies (DLB) and Parkinson's disease (PD). This provides an opportunity to directly observe the evolution of prodromal DLB and to identify which cognitive variables are the strongest predictors of evolving dementia. METHODS: IRBD participants (n = 754) from 10 centers of the International RBD Study Group underwent annual neuropsychological assessment. Competing risk regression analysis determined optimal predictors of dementia. Linear mixed-effect models determined the annual progression of neuropsychological testing. RESULTS: Reduced attention and executive function, particularly performance on the Trail Making Test Part B, were the strongest identifiers of early DLB. In phenoconverters, the onset of cognitive decline began up to 10 years prior to phenoconversion. Changes in verbal memory best differentiated between DLB and PD subtypes. DISCUSSION: In iRBD, attention and executive dysfunction strongly predict dementia and begin declining several years prior to phenoconversion. HIGHLIGHTS: Cognitive decline in iRBD begins up to 10 years prior to phenoconversion. Attention and executive dysfunction are the strongest predictors of dementia in iRBD. Decline in episodic memory best distinguished dementia-first from parkinsonism-first phenoconversion.

Monoaminergic Degeneration and Ocular Motor Abnormalities in De Novo Parkinson's Disease.

BACKGROUND: Evaluating eye movements in Parkinson's disease (PD) provides valuable insights into the underlying pathophysiological changes. OBJECTIVE: The aim was to investigate the relationship between monoaminergic degeneration and ocular motor abnormalities in de novo PD. METHODS: Drug-naive PD patients who underwent N-(3-[18 F]fluoropropyl)-2-carbomethoxy-3-(4-iodophenyl) nortropane positron emission tomography scans and video-oculography at diagnosis were eligible. Measurements of saccadic accuracy, latency, and smooth pursuit gain and square wave jerk frequency were collected. Patients underwent Movement Disorders Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) and detailed cognitive tests. We investigated the associations between ocular motor measurements and specific tracer uptake ratios (SUR) in the caudate nucleus, anterior and posterior putamen, thalamus, and dorsal raphe nuclei, along with motor and cognitive symptoms. RESULTS: One-hundred twenty-four subjects were included in this study. Saccadic accuracy was positively associated with parkinsonian motor severity expressed as Hoehn and Yahr stages, MDS-UPDRS Part III scores, and subscores for bradykinesia and rigidity but not with tremor scores (PFDR < 0.05). Saccadic accuracy correlated with poor performances in the Rey-Complex-Figure copy, and latency with the Digit Symbol Coding and the Montreal Cognitive Assessment scores (PFDR < 0.05). Prolonged saccadic latency correlated with reduced thalamic SUR, whereas decreased saccadic accuracy correlated with reduced SUR in the anterior and posterior putamen (PFDR < 0.05). Reduced smooth pursuit gain showed associations with reduced SUR in the dorsal raphe, a serotonin-predominant region, but did not correlate with parkinsonism severity scores. CONCLUSION: Defective dopaminergic and nondopaminergic neural systems may discretely influence ocular motor function in de novo PD patients. © 2023 International Parkinson and Movement Disorder Society.

Sex differences in gastrointestinal dysfunction among patients with Parkinson's disease.

BACKGROUND AND OBJECTIVE: Sex differences in gastrointestinal dysfunction have not been systematically analyzed in patients with Parkinson's disease (PD). This study was aimed to investigate the sex differences in gastrointestinal dysfunctions among the patients with PD using a multicenter trial dataset. METHODS: We analyzed the baseline data of prospectively enrolled set of patients with gastrointestinal dysfunctions. Possible sex differences in gastrointestinal symptoms assessed on the Nepean Dyspepsia Index-Korean Version (NDI-K), gastrointestinal symptom diary, and Bristol stool scale were analyzed in association with clinical PD severity and antiparkinsonian drug dosages by multiple linear regression models. We also performed post hoc analysis of the dyspepsia symptom sub-items, adjusting for multiple comparisons. RESULTS: Sixty-six of the 144 participants were female (45.8%). There were no differences in age, PD duration, Hoehn and Yahr stage, and daily dopaminergic medication dosages between sexes. NDI-K symptom and dyspepsia scores were correlated with the activity of daily living in females but not in males. In the multiple regression analysis controlling for all possible variables, female patients were shown to have worse gastrointestinal symptoms than males. When we performed post hoc analysis of the dyspepsia symptoms, inability to finish a regular meal and nausea were significantly worse in female patients. Gastrointestinal symptom diary supported that female patients more frequently complained of early fullness and bloating in the upper abdomen after meals than males, and burning pain in upper abdomen was more severe in female patients. CONCLUSION: Gastrointestinal dysfunctions may differentially affect female and male PD patients.

Validation of the REM behaviour disorder phenoconversion-related pattern in an independent cohort.

BACKGROUND: A brain glucose metabolism pattern related to phenoconversion in patients with idiopathic/isolated REM sleep behaviour disorder (iRBDconvRP) was recently identified. However, the validation of the iRBDconvRP in an external, independent group of iRBD patients is needed to verify the reproducibility of such pattern, so to increase its importance in clinical and research settings. The aim of this work was to validate the iRBDconvRP in an independent group of iRBD patients. METHODS: Forty iRBD patients (70 ± 5.59 years, 19 females) underwent brain [18F]FDG-PET in Seoul National University. Thirteen patients phenoconverted at follow-up (7 Parkinson disease, 5 Dementia with Lewy bodies, 1 Multiple system atrophy; follow-up time 35 ± 20.56 months) and 27 patients were still free from parkinsonism/dementia after 62 ± 29.49 months from baseline. We applied the previously identified iRBDconvRP to validate its phenoconversion prediction power. RESULTS: The iRBDconvRP significantly discriminated converters from non-converters iRBD patients (p = 0.016; Area under the Curve 0.74, Sensitivity 0.69, Specificity 0.78), and it significantly predicted phenoconversion (Hazard ratio 4.26, C.I.95%: 1.18-15.39). CONCLUSIONS: The iRBDconvRP confirmed its robustness in predicting phenoconversion in an independent group of iRBD patients, suggesting its potential role as a stratification biomarker for disease-modifying trials.

Aggresomal sequestration and STUB1-mediated ubiquitylation during mammalian proteaphagy of inhibited proteasomes.

The 26S proteasome, a self-compartmentalized protease complex, plays a crucial role in protein quality control. Multiple levels of regulatory systems modulate proteasomal activity for substrate hydrolysis. However, the destruction mechanism of mammalian proteasomes is poorly understood. We found that inhibited proteasomes are sequestered into the insoluble aggresome via HDAC6- and dynein-mediated transport. These proteasomes colocalized with the autophagic receptor SQSTM1 and cleared through selective macroautophagy, linking aggresomal segregation to autophagic degradation. This proteaphagic pathway was counterbalanced with the recovery of proteasomal activity and was critical for reducing cellular proteasomal stress. Changes in associated proteins and polyubiquitylation on inhibited 26S proteasomes participated in the targeting mechanism to the aggresome and autophagosome. The STUB1 E3 Ub ligase specifically ubiquitylated purified human proteasomes in vitro, mainly via Lys63-linked chains. Genetic and chemical inhibition of STUB1 activity significantly impaired proteasome processing and reduced resistance to proteasomal stress. These data demonstrate that aggresomal sequestration is the crucial upstream event for proteasome quality control and overall protein homeostasis in mammals.

Brain Metabolic Correlates of Dopaminergic Denervation in Prodromal and Early Parkinson's Disease.

BACKGROUND: It remains unclear how brain metabolic activities transform in response to dopamine deficiency in the prodromal and early phases of Parkinson's disease (PD). OBJECTIVE: To investigate the relationship between nigrostriatal dopaminergic denervation and brain glucose metabolism in patients with isolated rapid eye movement sleep behavior disorder (iRBD) and early PD. METHODS: This cohort study included 28 patients with polysomnography-confirmed iRBD, 24 patients with de novo PD with probable rapid eye movement sleep behavior disorder (denovo PD), and 28 healthy controls (HCs) who underwent two positron emission tomography scans with 18 F-fluorodeoxyglucose (all participants) and 18 F-N-3-fluoropropyl-2ß-carboxymethoxy-3ß-(4-iodophenyl)-nortropane (except for one denovo PD patient and 15 HCs). We analyzed striatal and voxel-wise whole-brain glucose metabolism in relation to nigrostriatal dopaminergic integrity and comparatively investigated the whole-brain metabolic connectivity among the groups. We also assessed longitudinal metabolic changes against progressive dopaminergic denervation over 4 years in the iRBD group. RESULTS: From HCs to iRBD and finally to the denovo PD, dopaminergic integrity positively correlated with metabolic activity in the caudate, whereas a negative correlation was observed in the posterior putamen. In the iRBD group, there was a metabolic increase in the inferior orbitofrontal cortex against putaminal dopaminergic denervation at baseline, but negative correlations were newly observed in the superior orbitofrontal cortex and superior frontal gyrus at the 4-year follow-up. The denovo PD group showed negative correlations in the cerebellum and fusiform gyrus. Intra- and inter-regional metabolic connectivities in the parieto-occipital cortices were enhanced in the iRBD group compared with the denovo PD and HC groups. In the iRBD group, overall metabolic connectivity was strengthened along with enhanced basal ganglia-frontal connection by advancing dopaminergic denervation. CONCLUSIONS: Our findings suggest diverse trajectories of metabolic responses associated with dopaminergic denervation between individual brain areas in the prodromal and early PD stages. © 2022 International Parkinson and Movement Disorder Society.

Structural implication of substrate binding by peptidoglycan remodeling enzyme MepS.

Constant remodeling is necessary for bacterial cell growth and bacterial morphogenesis; peptidoglycan (PG) is a crucial component in this process. Murein DD-endopeptidase (MepS), initially annotated as Spr from E. coli K12, is a NlpC/P60 family endopeptidase, which cleaves the meso-diaminopimelate (DAP)-D-Ala peptide bond of PG. The Cys68, His119, His131 triad form the active site residues. MepS has autolytic activity, which is strictly regulated by a periplasmic degradation system comprising the NlpI/Prc protease complex. MepS is essential for maintaining the cell viability, and therefore, it is a potential target for developing antibiotics. This study aimed to understand the structural basis of substrate recognition and degradation. We determined the high-resolution structures of MepS, after mutating Cys68 to serine (MepS-C68S) to improve stability. We further found that citrate and L-malate molecules bind to the active site of MepS-C68S; this is in line with the recurrent observation of organic acids binding to PG endopeptidases. The presence of conserved residues on the surface revealed the potential peptide binding sites of MepS. We modelled a cross-linked peptide model of meso-DAP-D-Ala-meso-DAP, bound to the active site groove of MepS-C68S. Two conserved tyrosine residues, Tyr56 and Tyr147 appeared to be essential for the recognition of peptides. Our structural discoveries could provide insights for the design of novel antibiotics targeting MepS.

Longitudinal Changes in Isolated Rapid Eye Movement Sleep Behavior Disorder-Related Metabolic Pattern Expression.

BACKGROUND: It remains unclear whether and how the isolated rapid eye movement (REM) sleep behavior disorder (iRBD)-related metabolic pattern (RBDRP) changes with disease progression in iRBD. OBJECTIVE: To examine longitudinal changes in RBDRP expression in iRBD patients and to explore trajectories of relative metabolic activities of individual brain regions constituting RBDRP. METHODS: In this cohort study, 25 iRBD patients (mean age [±standard deviation], 69.2 ± 5.3 years; 12 [48%] patients were men) and 24 age-matched healthy controls were included. The patients underwent at least two 18 F-fluorodeoxyglucose positron emission tomography scans at baseline and at the 2-year and/or 4-year follow-ups. We measured the RBDRP expression of the patients and controls which was validated by reproduction in a separate iRBD cohort (n = 13). RESULTS: At baseline, the RBDRP expression discriminated iRBD patients from healthy controls. However, the RBDRP expression z scores tended to decrease over time in the patients, especially with longer follow-ups, and this tendency was observed even in patients with high-risk of phenoconversion. Furthermore, the degree of RBDRP expression at baseline did not predict the disease conversion. The RBDRP breakdown was mainly provoked by the attenuation of relative hypermetabolism in the frontal cortex including premotor areas and relative hypometabolism in the occipital cortex. The putaminal metabolic activity increased steadily with the disease progression. CONCLUSIONS: The RBDRP expression in iRBD patients was altered significantly over time. Some of the brain metabolic changes seem to represent attempted functional compensation against ongoing neurodegeneration. The RBDRP expression measurement at one time point may not be a reliable biomarker for predicting disease conversion. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Erythropoietin signaling in osteoblasts is required for normal bone formation and for bone loss during erythropoietin-stimulated erythropoiesis.

Erythropoietin (EPO) regulates erythropoiesis by binding to erythropoietin receptor (Epor) on erythroid progenitor cells. Epor is also expressed on bone forming osteoblasts and bone loss accompanies EPO-stimulated erythropoiesis in mice. Mice with Epor restricted to erythroid tissue exhibit reduced bone and increased marrow adipocytes; in contrast, transgenic mice (Tg) with osteoblastic-specific deletion of Epor exhibit reduced trabecular bone with age without change in marrow adipocytes. By 12 weeks, male Tg mice had 22.2% and female Tg mice had 29.6% reduced trabecular bone volume (BV) compared to controls. EPO administration (1200 U/kg) for 10 days reduced trabecular bone in control mice but not in Tg mice. There were no differences in numbers of osteoblasts, osteoclasts, and marrow adipocytes in Tg mice, suggesting independence of EPO signaling in mature osteoblasts, osteoclasts, and adipocytes. Female Tg mice had increased number of dying osteocytes and male Tg mice had a trend for more empty lacunae. Osteogenic cultures from Tg mice had reduced differentiation and mineralization with reduced Alpl and Runx2 transcripts. In conclusion, endogenous EPO-Epor signaling in osteoblasts is important in bone remodeling, particularly trabecular bone and endogenous Epor expression in osteoblasts is required for bone loss accompanying EPO-stimulated erythropoiesis.

Cognitive signature of brain FDG PET based on deep learning: domain transfer from Alzheimer's disease to Parkinson's disease.

PURPOSE: Although functional brain imaging has been used for the early and objective assessment of cognitive dysfunction, there is a lack of generalized image-based biomarker which can evaluate individual's cognitive dysfunction in various disorders. To this end, we developed a deep learning-based cognitive signature of FDG brain PET adaptable for Parkinson's disease (PD) as well as Alzheimer's disease (AD). METHODS: A deep learning model for discriminating AD from normal controls (NCs) was built by a training set consisting of 636 FDG PET obtained from Alzheimer's Disease Neuroimaging Initiative database. The model was directly transferred to images of mild cognitive impairment (MCI) patients (n = 666) for identifying who would rapidly convert to AD and another independent cohort consisting of 62 PD patients to differentiate PD patients with dementia. The model accuracy was measured by area under curve (AUC) of receiver operating characteristic (ROC) analysis. The relationship between all images was visualized by two-dimensional projection of the deep learning-based features. The model was also designed to predict cognitive score of the subjects and validated in PD patients. Cognitive dysfunction-related regions were visualized by feature maps of the deep CNN model. RESULTS: AUC of ROC for differentiating AD from NC was 0.94 (95% CI 0.89-0.98). The transfer of the model could differentiate MCI patients who would convert to AD (AUC = 0.82) and PD with dementia (AUC = 0.81). The two-dimensional projection mapping visualized the degree of cognitive dysfunction compared with normal brains regardless of different disease cohorts. Predicted cognitive score, an output of the model, was highly correlated with the mini-mental status exam scores. Individual cognitive dysfunction-related regions included cingulate and high frontoparietal cortices, while they showed individual variability. CONCLUSION: The deep learning-based cognitive function evaluation model could be successfully transferred to multiple disease domains. We suggest that this approach might be extended to an objective cognitive signature that provides quantitative biomarker for cognitive dysfunction across various neurodegenerative disorders.

Retina thickness as a marker of neurodegeneration in prodromal lewy body disease.

OBJECTIVES: We investigated retinal change and its relationship with neurodegeneration markers in a prodromal Parkinson cohort. METHODS: A total of 30 patients with idiopathic rapid eye movement sleep behavior disorder were recruited. Participants underwent olfactory testing, macular optical coherence tomography, microperimetry, contrast sensitivity test, and brain N-(3-[18 F]fluoropropyl)-2-carbomethoxy-3-(4-iodophenyl) nortropane positron emission tomography. We measured the ganglion cell complex thicknesses and investigated its correlation with olfactory function and striatal dopamine transporter availability. A linear mixed-effect model was applied with adjustment for multiple comparisons. RESULTS: The parafoveal ganglion-cell-complex thickness in this cohort lay between our healthy control and drug-naïve Parkinson's disease group data. Idiopathic rapid eye movement sleep behavior disorder patients also had contrast sensitivity impairment as in Parkinson's disease with a nonsignificant change in macular sensitivities. Macular ganglion cell complex thickness correlated with olfactory scores and with striatal dopamine transporter availabilities. CONCLUSIONS: Macular ganglion cell complex thinning may be a marker of neurodegeneration in prodromal Parkinson's disease. © 2019 International Parkinson and Movement Disorder Society.

Double-Blind, Randomized, Placebo-Controlled Trial of DA-9701 in Parkinson's Disease: PASS-GI Study.

OBJECTIVES: This study aimed to assess the efficacy of DA-9701 on gastrointestinal symptom-related quality of life in patients with Parkinson's disease on stable dopaminergic medications. METHODS: This multicenter, double-blind, placebo-controlled, phase 4 trial included a total of 144 patients with Parkinson's disease with gastrointestinal dysfunctions based on predefined criteria. Participants were randomized to take either DA-9701 or placebo for 4 weeks, and then both groups were administered DA-9701 for an additional 8 weeks while antiparkinsonian medications were unchanged. The primary outcome measure was gastrointestinal symptoms and related quality-of-life changes assessed on the Korean Nepean dyspepsia index after 4 and 12 weeks of therapy. We also evaluated the impact of DA-9701 therapy on parkinsonian motor symptoms at each time point. RESULTS: The gastrointestinal symptom-related quality-of-life score significantly improved in the DA-9701-treated group compared with the placebo-treated group after 4weeks (adjusted P = 0.012 by linear mixed effect model analysis). The overall gastrointestinal symptom and dyspepsia sum scores improved at 12 weeks after intervention in the DA-9701-first treated group (adjusted P = 0.002 and 0.014, respectively) and also in the placebo-first treated group (adjusted P = 0.019 and 0.039) compared with the baseline. Parkinsonian motor severity was not significantly affected by DA-9701 treatment in both groups at 4 and 12 weeks after intervention. There were no drug-related serious adverse events throughout the trial. CONCLUSIONS: DA-9701 therapy improved gastrointestinal symptom-related quality of life, and 12 weeks of daily administration can relieve the overall severity of gastrointestinal symptoms in patients with Parkinson's disease without affecting motor symptoms. (Clinical trial identifier: NCT02775591.) © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Contrast sensitivity impairment in drug-naïve Parkinson's disease patients associates with early cognitive decline.

OBJECTIVES: To investigate the contrast sensitivity function in drug-naïve Parkinson's disease (PD) patients and its predictive value with longitudinal follow-up data. METHODS: We included newly diagnosed non-demented PD patients who performed contrast sensitivity test between 2013 and 2014. Contrast sensitivity function at drug-naïve state in PD patients was compared with age-matched normal control data of our center. Correlation between contrast sensitivity function and parkinsonian motor and non-motor features including the Mini-Mental State Exam (MMSE) score at the time of diagnosis were analyzed by linear regression. With longitudinal follow-up data after initiating anti-parkinsonian therapy, the risk conferred on subsequent visual hallucinations and cognitive impairment requiring anti-dementia drugs was analyzed by dichotomizing PD group based on the initial contrast sensitivity function. RESULTS: Forty-eight patients were finally included, and mean follow-up periods were 43 months. Contrast sensitivity function in drug-naïve PD patients was significantly worse than controls. Contrast sensitivity function correlated with sleep disturbance (p = 0.001) and global cognitive status reflected by the MMSE score (p = 0.020). It also associated with further decline in the MMSE during the follow-ups (p = 0.029). Patients with below average contrast sensitivity function at the time of diagnosis showed higher risk of cognitive decline requiring anti-dementia drugs (adjusted odds ratio = 4.68, p = 0.04) and of visual hallucinations (adjusted odds ratio = 12.54, p = 0.04) than those above average function during the follow-up. CONCLUSION: Contrast sensitivity impairment in drug-naïve PD patients associates with clinical demand for therapeutic intervention of cognitive decline as well as development of visual hallucinations in the early course of the disease.

Late-life falling and depressive symptoms associated with the risk of Parkinson's disease: a nationwide cohort data analysis.

BACKGROUND: This study aimed to evaluate the relationship between the history of late-life falling and the development of Parkinson's disease (PD) and investigate whether depressive symptoms interact with falling to increase PD risk. METHODS: We identified 1,223,726 subjects without PD who underwent the National Screening Program for Transitional Age at 66 years between 2009 and 2013 using the National Health Cohort database. In this program, every participant was assessed whether they experienced falling for the past six months. Depressive symptoms were evaluated with a three-item questionnaire extracted from the Geriatric Depression Scale. Incident PD was traced for a mean 4.23 ± 1.50 years. Cox proportional hazard regression models were used to assess the risk of PD by falling history with and without depressive symptoms after adjusting for other confounding variables. RESULTS: In this cohort, the PD incidence rate was 1.30 and 1.03 cases per 1000 person-years in groups with and without falling and 1.34 and 1.00 cases per 1000 person-years in groups with and without depressive symptoms. The predictive risk of PD was increased by either a history of falling (HR = 1.24; 95% CI 1.11-1.40) or the presence of depressive symptoms (HR = 1.31; 95% CI 1.21-1.42) after adjusting for possible confounding variables. For individuals with both falling and depressive symptoms, PD risk increased further (HR = 1.66; 95% CI 1.40-1.97), but with sex-differences. The two factors increased PD risk in a sub-additive manner in men, whereas synergistically in women. CONCLUSIONS: This national cohort database shows that late-life depressive symptoms accompanied by a falling event pose an increase in the risk of PD in older adults.

Structure and substrate specificity of ß-ketoacyl-acyl carrier protein synthase III from Acinetobacter baumannii.

Originally annotated as the initiator of fatty acid synthesis (FAS), ß-ketoacyl-acyl carrier protein synthase III (KAS III) is a unique component of the bacterial FAS system. Novel variants of KAS III have been identified that promote the de novo use of additional extracellular fatty acids by FAS. These KAS III variants prefer longer acyl-groups, notably octanoyl-CoA. Acinetobacter baumannii, a clinically important nosocomial pathogen, contains such a multifunctional KAS III (AbKAS III). To characterize the structural basis of its substrate specificity, we determined the crystal structures of AbKAS III in the presence of different substrates. The acyl-group binding cavity of AbKAS III and co-crystal structure of AbKAS III and octanoyl-CoA confirmed that the cavity can accommodate acyl groups with longer alkyl chains. Interestingly, Cys264 formed a disulfide bond with residual CoA used in the crystallization, which distorted helices at the putative interface with acyl-carrier proteins. The crystal structure of KAS III in the alternate conformation can also be utilized for designing novel antibiotics.