Systemic sclerosis without antinuclear antibodies or Raynaud's phenomenon: a multicentre study in the prospective EULAR Scleroderma Trials and Research (EUSTAR) database

Objective. To assess patients with SSc who present without circulating ANAs or RP. Methods. Five thousand three hundred and ninety patients who fulfilled the ACR criteria for SSc and were enrolled in the EULAR Scleroderma Trials and Research (EUSTAR) database were screened for the absence of both RP and circulating ANA. To differentiate SSc from its mimics, additional information was gathered using a standardized questionnaire. Results. Five thousand three hundred and seventy-eight (99.8%) of the 5390 SSc patients in the EUSTAR database had either detectable ANA or a history of RP. Twelve (0.2%) patients lacked both circulating ANA and RP. Details of the medical history could be obtained for seven patients. Three cases were compatible with ANA-negative and RP-negative SSc and were not typical of any known SSc mimic. Four patients had a malignancy: two had breast cancer, one had multiple myeloma with possible scleromyxoedema and one had bladder carcinoma. There was no temporal relationship between the onset of skin fibrosis and that of the tumour. Although no patient with confirmed nephrogenic systemic fibrosis was identified among the cases of ANA-negative and RP-negative SSc, the presentation of one patient could be compatible with that of nephrogenic systemic fibrosis other than for the absence of chronic kidney disease or of known prior gadolinium exposure. Conclusion. We have identified a very small subgroup of SSc patients who lack both circulating ANA and RP, none of whom fulfils the diagnostic criteria for any known SSc mimic. Prospective studies are needed to elucidate the clinical presentation, evolution and outcome of such patient

Orexin receptors exert a neuroprotective effect in Alzheimer's disease (AD) via heterodimerization with GPR103

Orexins are neuropeptides that regulate the sleep-wake cycle and feeding behaviour. QRFP is a newly discovered neuropeptide which exerts similar orexigenic activity, thus playing an important role in energy homeostasis and regulation of appetite. The exact expression and signalling characteristics and physiological actions of QRFP and its receptor GPR103 are poorly understood. Alzheimerâ €™ s disease (AD) patients experience increased nocturnal activity, excessive daytime sleepiness, and weight loss. We hypothesised therefore that orexins and QRFP might be implicated in the pathophysiology of AD. We report that the down-regulation of hippocampal orexin receptors (OXRs) and GPR103 particularly in the cornu ammonis (CA) subfield from AD patients suffering from early onset familial AD (EOFAD) and late onset familial AD (LOAD). Using an in vitro model we demonstrate that this downregulation is due to to Aβ-plaque formation and tau hyper-phosphorylation. Transcriptomics revealed a neuroprotective role for both orexins and QRFP. Finally we provide conclusive evidence using BRET and FRET that OXRs and GPR103 form functional hetero-dimers to exert their effects involving activation of ERK 1/2. Pharmacological intervention directed at the orexigenic system may prove to be an attractive avenue towards the discovery of novel therapeutics for diseases such as AD and improving neuroprotective signalling pathways

Gut Microbiome Signatures of Risk and Prodromal Markers of Parkinson Disease

Objective Alterations of the gut microbiome in Parkinson disease (PD) have been repeatedly demonstrated. However, little is known about whether such alterations precede disease onset and how they relate to risk and prodromal markers of PD. We investigated associations of these features with gut microbiome composition. Methods Established risk and prodromal markers of PD as well as factors related to diet/lifestyle, bowel function, and medication were studied in relation to bacterial alpha-/beta-diversity, enterotypes, and differential abundance in stool samples of 666 elderly TREND (Tubingen Evaluation of Risk Factors for Early Detection of Neurodegeneration) study participants. Results Among risk and prodromal markers, physical activity, occupational solvent exposure, and constipation showed associations with alpha-diversity. Physical activity, sex, constipation, possible rapid eye movement sleep behavior disorder (RBD), and smoking were associated with beta-diversity. Subthreshold parkinsonism and physical activity showed an interaction effect. Among other factors, age and urate-lowering medication were associated with alpha- and beta-diversity. Physical inactivity and constipation were highest in individuals with theFirmicutes-enriched enterotype. Constipation was lowest and subthreshold parkinsonism least frequent in individuals with thePrevotella-enriched enterotype. Differentially abundant taxa were linked to constipation, physical activity, possible RBD, smoking, and subthreshold parkinsonism. Substantia nigra hyperechogenicity, olfactory loss, depression, orthostatic hypotension, urinary/erectile dysfunction, PD family history, and the prodromal PD probability showed no significant microbiome associations. Interpretation Several risk and prodromal markers of PD are associated with gut microbiome composition. However, the impact of the gut microbiome on PD risk and potential microbiome-dependent subtypes in the prodrome of PD need further investigation based on prospective clinical and (multi)omics data in incident PD cases. ANN NEUROL 2020Peer reviewe

Transcriptome pathways unique to dehydration tolerant relatives of modern wheat

Among abiotic stressors, drought is a major factor responsible for dramatic yield loss in agriculture. In order to reveal differences in global expression profiles of drought tolerant and sensitive wild emmer wheat genotypes, a previously deployed shock-like dehydration process was utilized to compare transcriptomes at two time points in root and leaf tissues using the Affymetrix GeneChip(R) Wheat Genome Array hybridization. The comparison of transcriptomes reveal several unique genes or expression patterns such as differential usage of IP(3)-dependent signal transduction pathways, ethylene- and abscisic acid (ABA)-dependent signaling, and preferential or faster induction of ABA-dependent transcription factors by the tolerant genotype that distinguish contrasting genotypes indicative of distinctive stress response pathways. The data also show that wild emmer wheat is capable of engaging known drought stress responsive mechanisms. The global comparison of transcriptomes in the absence of and after dehydration underlined the gene networks especially in root tissues that may have been lost in the selection processes generating modern bread wheats

Parkinson’s disease: evolution of cognitive impairment and CSF Aβ₁−₄₂ profiles in a prospective longitudinal study

OBJECTIVE: To evaluate the evolution of cognitive impairment in relation to cerebrospinal fluid (CSF) profiles of amyloid-β (Aβ), total-Tau and phosphorylated-Tau in Parkinson’s disease (PD). METHODS: Prospective, longitudinal, observational study up to 10 years with follow-up every 2  years. We assessed CSF profiles in 415 patients with sporadic PD (median age 66; 63% men) and 142 healthy controls (median age 62; 43% men). RESULTS: Patients with PD with low CSF Aβ₁−₄₂ levels at baseline were more often cognitively impaired than patients with intermediate and high Aβ₁−₄₂ levels. Sixty-seven per cent of the patients with low Aβ₁−₄₂ levels at baseline and normal cognition developed cognitive impairment during follow-up, compared with 41% and 37% of patients having intermediate and high CSF Aβ₁−₄₂ levels. Kaplan-Meier survival curves and Cox regression revealed that patients with low CSF Aβ₁−₄₂ levels at baseline developed cognitive impairment more frequently and earlier during follow-up. CONCLUSION: We conclude that in patients with sporadic PD, low levels of Aβ₁−₄₂ are associated with a higher risk of developing cognitive impairment earlier in the disease process at least in a subgroup of patients

cAMP responsive element-binding protein phosphorylation is necessary for perirhinal long-term potentiation and recognition memory

We established the importance of phosphorylation of cAMP responsive element-binding protein (CREB) to both the familiarity discrimination component of long-term recognition memory and plasticity within the perirhinal cortex of the temporal lobe. Adenoviral transduction of perirhinal cortex (and adjacent visual association cortex) with a dominant-negative inhibitor of CREB impaired the preferential exploration of novel over familiar objects at a long (24 h) but not a short (15 min) delay, disrupted the normal reduced activation of perirhinal neurons to familiar compared with novel pictures, and impaired long-term potentiation of synaptic transmission in perirhinal slices. The consistency of these effects across the behavioral, systems, and cellular levels of analysis provides strong evidence for involvement of CREB phosphorylation in synaptic plastic processes within perirhinal cortex necessary for long-term recognition memory

A mathematical model of aging-related and cortisol induced hippocampal dysfunction

<p>Abstract</p> <p>Background</p> <p>The hippocampus is essential for declarative memory synthesis and is a core pathological substrate for Alzheimer's disease (AD), the most common aging-related dementing disease. Acute increases in plasma cortisol are associated with transient hippocampal inhibition and retrograde amnesia, while chronic cortisol elevation is associated with hippocampal atrophy. Thus, cortisol levels could be monitored and managed in older people, to decrease their risk of AD type hippocampal dysfunction. We generated an in silico<it/>model of the chronic effects of elevated plasma cortisol on hippocampal activity and atrophy, using the systems biology mark-up language (SBML). We further challenged the model with biologically based interventions to ascertain if cortisol associated hippocampal dysfunction could be abrogated.</p> <p>Results</p> <p>The in silico<it/>SBML model reflected the in vivo<it/>aging of the hippocampus and increased plasma cortisol and negative feedback to the hypothalamic pituitary axis. Aging induced a 12% decrease in hippocampus activity (HA), increased to 30% by acute and 40% by chronic elevations in cortisol. The biological intervention attenuated the cortisol associated decrease in HA by 2% in the acute cortisol simulation and by 8% in the chronic simulation.</p> <p>Conclusion</p> <p>Both acute and chronic elevations in cortisol secretion increased aging-associated hippocampal atrophy and a loss of HA in the model. We suggest that this first SMBL model, in tandem with in vitro<it/>and in vivo<it/>studies, may provide a backbone to further frame computational cortisol and brain aging models, which may help predict aging-related brain changes in vulnerable older people.</p

A novel hybrid promoter responsive to pathophysiological and pharmacological regulation

The aim of this study was to construct a promoter containing DNA motifs for an endogenous transcription factor associated with inflammation along with motifs for pharmacological regulation factors. We demonstrate in transfected cells that expression of a gene of interest is induced by hypoxic conditions or through pharmacological induction, and also show pharmacological repression. In vivo studies utilised electroporation of plasmid to mouse paws, a delivery method shown to be effective by bioluminescence imaging. For gene therapy, the promoter was used to drive expression of IL-1Ra in a paw inflammation model with therapeutic effect observed which was further enhanced when the promoter was additionally induced with a pharmacological activator. One of the most important observations from this study was that promoter induction by hypoxia or inflammation could be prevented by the pharmacological repressor in the absence of doxycycline. These studies demonstrate that hybrid promoters enable pharmacological adjustment to the pathophysiological level of gene expression and, importantly, that they allow termination of gene expression even in the presence of pathophysiological stimuli

Response to Therapeutic Sleep Deprivation: A Naturalistic Study of Clinical and Genetic Factors and Post-treatment Depressive Symptom Trajectory

Research has shown that therapeutic sleep deprivation (SD) has rapid antidepressant effects in the majority of depressed patients. Investigation of factors preceding and accompanying these effects may facilitate the identification of the underlying biological mechanisms. This exploratory study aimed to examine clinical and genetic factors predicting response to SD and determine the impact of SD on illness course. Mood during SD was also assessed via visual analogue scale. Depressed inpatients (n = 78) and healthy controls (n = 15) underwent ~36 h of SD. Response to SD was defined as a score of ≤ 2 on the Clinical Global Impression Scale for Global Improvement. Depressive symptom trajectories were evaluated for up to a month using self/expert ratings. Impact of genetic burden was calculated using polygenic risk scores for major depressive disorder. In total, 72% of patients responded to SD. Responders and non-responders did not differ in baseline self/expert depression symptom ratings, but mood differed. Response was associated with lower age (p = 0.007) and later age at life-time disease onset (p = 0.003). Higher genetic burden of depression was observed in non-responders than healthy controls. Up to a month post SD, depressive symptoms decreased in both patients groups, but more in responders, in whom effects were sustained. The present findings suggest that re-examining SD with a greater focus on biological mechanisms will lead to better understanding of mechanisms of depression