α-Synucleinopathies are characterized by autonomic dysfunction and motor impairments. In the pure autonomic failure (PAF), α-synuclein (α-Syn) pathology is confined within the autonomic nervous ...system with no motor features, but mouse models recapitulating PAF without motor dysfunction are lacking. Here, we show that in TgM83
mice, inoculation of α-Syn preformed fibrils (PFFs) into the stellate and celiac ganglia induces spreading of α-Syn pathology only through the autonomic pathway to both the central nervous system (CNS) and the autonomic innervation of peripheral organs bidirectionally. In parallel, the mice develop autonomic dysfunction, featured by orthostatic hypotension, constipation, hypohidrosis and hyposmia, without motor dysfunction. Thus, we have generated a mouse model of pure autonomic dysfunction caused by α-Syn pathology. This model may help define the mechanistic link between transmission of pathological α-Syn and the cardinal features of autonomic dysfunction in α-synucleinopathy.
Animal studies implicate meningeal lymphatic dysfunction in the pathogenesis of neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease (PD). However, there is no direct ...evidence in humans to support this role
. In this study, we used dynamic contrast-enhanced magnetic resonance imaging to assess meningeal lymphatic flow in cognitively normal controls and patients with idiopathic PD (iPD) or atypical Parkinsonian (AP) disorders. We found that patients with iPD exhibited significantly reduced flow through the meningeal lymphatic vessels (mLVs) along the superior sagittal sinus and sigmoid sinus, as well as a notable delay in deep cervical lymph node perfusion, compared to patients with AP. There was no significant difference in the size (cross-sectional area) of mLVs in patients with iPD or AP versus controls. In mice injected with α-synuclein (α-syn) preformed fibrils, we showed that the emergence of α-syn pathology was followed by delayed meningeal lymphatic drainage, loss of tight junctions among meningeal lymphatic endothelial cells and increased inflammation of the meninges. Finally, blocking flow through the mLVs in mice treated with α-syn preformed fibrils increased α-syn pathology and exacerbated motor and memory deficits. These results suggest that meningeal lymphatic drainage dysfunction aggravates α-syn pathology and contributes to the progression of PD.
The locus for familial cortical myoclonic tremor with epilepsy (FCMTE) has long been mapped to 8q24 in linkage studies, but the causative mutations remain unclear. Recently, expansions of intronic ...TTTCA and TTTTA repeat motifs within
were found to be involved in the pathogenesis of FCMTE in Japanese pedigrees. We aim to identify the causative mutations of FCMTE in Chinese pedigrees.
We performed genetic linkage analysis by microsatellite markers in a five-generation Chinese pedigree with 55 members. We also used array-comparative genomic hybridisation (CGH) and next-generation sequencing (NGS) technologies (whole-exome sequencing, capture region deep sequencing and whole-genome sequencing) to identify the causative mutations in the disease locus. Recently, we used low-coverage (~10×) long-read genome sequencing (LRS) on the PacBio Sequel and Oxford Nanopore platforms to identify the causative mutations, and used repeat-primed PCR for validation of the repeat expansions.
Linkage analysis mapped the disease locus to 8q23.3-24.23. Array-CGH and NGS failed to identify causative mutations in this locus. LRS identified the intronic TTTCA and TTTTA repeat expansions in
as the causative mutations, thus corroborating the recently published results in Japanese pedigrees.
We identified the pentanucleotide repeat expansion in
as the causative mutation in Chinese FCMTE pedigrees. Our study also suggested that LRS is an effective tool for molecular diagnosis of genetic disorders, especially for neurological diseases that cannot be positively diagnosed by conventional clinical microarray and NGS technologies.
Mesenchymal stem cell (MSC) transplantation is a promising treatment strategy for spinal cord injury, but immunological rejection and possible tumor formation limit its application. The therapeutic ...effects of MSCs mainly depend on their release of soluble paracrine factors. Exosomes are essential for the secretion of these paracrine effectors. Bone marrow mesenchymal stem cell-derived exosomes (BMSC-EXOs) can be substituted for BMSCs in cell transplantation. However, the underlying mechanisms remain unclear. In this study, a rat model of T10 spinal cord injury was established using the impact method. Then, 30 minutes and 1 day after spinal cord injury, the rats were administered 200 μL exosomes via the tail vein (200 μg/mL; approximately 1 × 106 BMSCs). Treatment with BMSC-EXOs greatly reduced neuronal cell death, improved myelin arrangement and reduced myelin loss, increased pericyte/endothelial cell coverage on the vascular wall, decreased blood-spinal cord barrier leakage, reduced caspase 1 expression, inhibited interleukin-1β release, and accelerated locomotor functional recovery in rats with spinal cord injury. In the cell culture experiment, pericytes were treated with interferon-γ and tumor necrosis factor-α. Then, Lipofectamine 3000 was used to deliver lipopolysaccharide into the cells, and the cells were co-incubated with adenosine triphosphate to simulate injury in vitro. Pre-treatment with BMSC-EXOs for 8 hours greatly reduced pericyte pyroptosis and increased pericyte survival rate. These findings suggest that BMSC-EXOs may protect pericytes by inhibiting pyroptosis and by improving blood-spinal cord barrier integrity, thereby promoting the survival of neurons and the extension of nerve fibers, and ultimately improving motor function in rats with spinal cord injury. All protocols were conducted with the approval of the Animal Ethics Committee of Zhengzhou University on March 16, 2019.
MicroRNAs (miRNAs) regulate protein expression by antagonizing the translation of mRNAs and are effective regulators of normal nervous system development, function, and disease. MicroRNA-29b ...(miR-29b) plays a broad and critical role in brain homeostasis. In this study, we tested the function of miR-29b in animal and cell models by inhibiting miR-29b expression. Mouse models of middle cerebral artery occlusion were established using the modified Zea-Longa suture method. Prior to modeling, 50 nmol/kg miR-29b antagomir was injected via the tail vein. MiR-29b expression was found to be abnormally increased in ischemic brain tissue. The inhibition of miR-29b expression decreased the neurological function score and reduced the cerebral infarction volume and cell apoptosis. In addition, the inhibition of miR-29b significantly decreased the malondialdehyde level, increased superoxide dismutase activity, and Bcl-2 expression, and inhibited Bax and Caspase3 expression. PC12 cells were treated with glutamate for 12 hours to establish in vitro cell models of ischemic stroke and then treated with the miR-29 antagomir for 48 hours. The results revealed that miR-29b inhibition in PC12 cells increased Bcl-2 expression and inhibited cell apoptosis and oxidative damage. These findings suggest that the inhibition of miR-29b inhibits oxidative stress and cell apoptosis in ischemic stroke, producing therapeutic effects in ischemic stroke. This study was approved by the Laboratory Animal Care and Use Committee of the First Affiliated Hospital of Zhengzhou University (approval No. 201709276S) on September 27, 2017.
Highlights ► miR-195 can bind to 3′-UTR of BACE1 mRNA. ► miR-195 was decreased whereas BACE1 increased in AD animal model. ► pre-miR-195 transfection decreased the BACE1 expression in N2a cells. ► ...pre-miR-195 transfection decreased Aβ production.
Objective
Perivascular spaces (PVS), components of the glymphatic system in the brain, have been known to be important conduits for clearing metabolic waste, and this process mainly increases during ...sleep. Sleep disruption might result in PVS dysfunction and cognitive impairment. In this study, we aim to explore whether MRI-visible enlarged perivascular spaces (EPVS) could be imaging markers to predict cognitive impairment in chronic insomnia patients.
Method
We obtained data from 156 patients with chronic insomnia and 79 age-matched healthy individuals. Using T2-weighted MRI images, visible EPVS in various brain regions were measured and analyzed. The associations between EPVS numbers and cerebrospinal fluid (CSF) β-amyloid 42 (Aβ42), total tau (t-tau), and phosphorylated tau (p-tau) level in chronic insomnia patients were evaluated.
Result
Our results showed that MRI-visible EPVS in the frontal cortex, centrum semiovale, basal ganglia, and hippocampus of chronic insomnia patients with impaired cognition (ICG) significantly increased than that in normal cognition (NCG) patients. The increased MRI-visible EPVS in the frontal cortex, centrum semiovale, and basal ganglia were also associated with the increased CSF Aβ42, t-tau, and p-tau level in ICG patients. MRI-visible EPVS in the basal ganglia and centrum semiovale had high sensitivity and specificity in distinguishing ICG chronic insomnia patients from those with NCG.
Conclusion
Our study indicated that MRI-visible EPVS in the basal ganglia and centrum semiovale might be valuable imaging markers to predict cognitive impairment in chronic insomnia patients. It will be meaningful to discern those cognitive decline patients in preclinical stage and take some measures to prevent disease progression.
Key Points
• Increased MRI-visible EPVS were associated with the increased CSF Aβ42, t-tau, and p-tau level in older chronic insomnia patients with impaired cognition.
Traffic oscillation is a very important phenomenon in traffic flow studies and its characteristics are usually used to validate the developed traffic flow models and theories. In this paper, we ...firstly conduct an empirical study based on floating car data, focusing on the characteristic of traffic oscillations in terms of the overall amplitude and the spectrum of speed/acceleration as well as the relation between the characteristic quantities. It is found that the amplitude of both speed oscillations and acceleration oscillations grows with the increase of traffic speed. The spectrum analysis shows that the most energy would concentrate on a narrower band with the increase of standard deviation of speed/acceleration, and the periodicity in the speed oscillation is more salient than that in the corresponding acceleration oscillation. Then, three typical car-following models are tested: one is the deterministic model, while the other two are the stochastic models with different mechanisms of stochasticity. The simulation results indicate that the two stochastic models outperform the deterministic model in reproducing the observed oscillation characteristics qualitatively and quantitatively.
•The collected floating car data with high accuracy provides pinpoint evidence for the characteristic of traffic oscillations.•The IDM fails to reproduce qualitatively observed oscillations, while the 2D-IDM and SSAM could.•The formation and propagation of oscillations might be due to the stochasticity in car following.
The purpose of this study was to investigate the effect of Egr2 and Egr4 upregulation on ischemic stroke recovery of rats.
In this study, Sprague Dawley (SD) rats assigned at random into control, ...sham and MCAO (middle cerebral artery occlusion) group were treated accordingly to build MCAO models. The neurological severity scores (NSS) test was applied to assess rats' behavior. Triphenyltetrazolium chloride (TTC) staining reflected infarct areas while Nissl staining revealed the number of neurons. Levels of pro-inflammatory cytokines (interleukin IL-1β, IL-6 and tumor necrosis factor TNF-α) were judged by enzyme-linked immunosorbent assay (ELISA) in brain and serum tissues. We applied western blot to check the expression of Egr2, Egr4 and JNK/c-JUN (c-Jun N-terminal kinase) pathway. Further grouping of rats were based on various transfection, requiring control, sham, MCAO, MCAO + Egr2 cDNA (complementary DNA), MCAO + Egr4 cDNA, MCAO + Egr2 cDNA + Egr4 cDNA group to observe difference in MCAO recovery and JNK/c-JUN-pathway-related protein expression.
Under successful modeling of MCAO, western blot results suggested down-regulation of Egr2 and Egr4 and overexpression of pro-inflammatory cytokines. The JNK/c-JUN pathway was activated. On upregulation of Egr2 and Egr4 in infarct areas, neurological function of SD rats recovered along with repressed JNK/c-JUN pathway activation and increased neuron number.
Upregulation of Egr2 and Egr4 could demote the activation of JNK/c-JUN pathway and the expression of pro-inflammatory cytokines in MCAO rats, so that Egr2 and Egr4 might be potential targets for ischemic stroke in future.
•The purpose of this study was to investigate the effect of Egr2 and Egr4 upregulation on ischemic stroke recovery of rats.•Upregulation of Egr2 and Egr4 could demote the activation of JNK/c-JUN pathway.•Upregulation of Egr2 and Egr4 demote the expression of pro-inflammatory cytokines in MCAO rats.
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