Treatment with glatiramer acetate in APPswe/PS1dE9 mice at an early stage of Alzheimer's disease prior to amyloid-beta deposition delays the disease's pathological development and ameliorates cognitive decline.

Background: Alzheimer's disease (AD) is characterized by neuroinflammation, which is frequently accompanied by immune system dysfunction. Although the mechanism of neurodegenerative lesions is unclear, various clinical trials have highlighted that early intervention in AD is crucial to the success of treatment. In order to explore the potential of immunotherapy in the early period of AD, the present study evaluated whether application of glatiramer acetate (GA), an immunomodulatory agent approved for remitting-relapsing multiple sclerosis (RRMS), in the early stages of AD prior to amyloid beta (Aß) deposition altered the Aß pathology and cognitive impairments in APPswe/PSEN1dE9 (APP/PS1) transgenic mice. Methods: We treated two cohorts of pre-depositing and amyloid-depositing (2- and 6-month-old) APP/PS1 mice with weekly-GA subcutaneous injection over a 12-week period. We then tested spatial learning and memory using the Morris water maze (MWM) and the Y maze. Immunohistochemistry staining was utilized to analyze Aß burden in the brain as well as activated microglia. Furthermore, the inflammatory cytokine milieu within brains was estimated by quantitative real-time polymerase chain reaction, and the peripheral CD4+CD25+Foxp3+ regulatory T cells (Tregs) in the spleen were measured by flow cytometry. Results: We found that early GA administration reduced Aß burden and ameliorated cognitive decline. Meanwhile, the immune microenvironment had changed in the brain, with an increase in the production of anti-inflammatory cytokines and a decrease in microglial activation. Interestingly, early GA administration also modulated the peripheral immune system through the amplification of Tregs in the spleen. Conclusion: Overall, our findings revealed that GA treatment might enhance the central and peripheral immune systems' protective capabilities in the early stages of AD, eventually improving cognitive deficits. Our research supports the advantages of immunomodulatory treatments for AD at an early stage.

Distribution, connection and function of ALDH1A1+/TH+ neurons in substantia nigra pars reticulata of mouse.

The massive cell death of dopaminergic neurons (DANs) in substantia nigra pars compacta (SNC) is associated with motor diseases, such as Parkinson's disease. Moreover, as a subtype of DANs in SNC, ALDH1A1+ neurons show better resistance to PD related neurotoxin. DANs can also be found in the substantia nigra pars reticulata (SNR), however, whether they are ALDH1A1+ neurons are rarely reported, as well as their projection, function, and reaction in the PD pathology. We studied the distribution of ALDH1A1+ neurons and track their projection by injecting pAAV. We figured out that, in SNR, 87 % neurons are ALDH1A1+/TH+ in ALDH1A1+ cluster averagely, while ALDH1A1+/TH+: TH+ is 52 % averagely. There are two enrichment regions of ALDH1A1+/TH+ neurons at brgma -3.40 mm and brgma -3.70 mm in the SNR of the nTg mice. Nevertheless, in one type of PD-liked mice model, the proportion of ALDH1A1+/TH+: ALDH1A1+ neurons are 98 % averagely, while ALHD1A1+/TH+: TH+ is 57 %. Intriguingly, neuro-tracing discovered that there may be a previously unreported connection between SNR and anterior dorsal thalamus (ADT). The mouse received MPTP stereotactic injection to destroy TH+ neurons in SNR showed depression behavior, indicated the DANs death in SNR may contribute to depression behavior.

Three nervous system-specific expressed genes are potential biomarkers for the diagnosis of sporadic amyotrophic lateral sclerosis through a bioinformatic analysis.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is the most common neurodegenerative disease in adults. However, ALS, especially sporadic ALS (sALS), is difficult to diagnose due to the lack of biomarkers. RESULTS: We used the bioinformatics technology to find the potential biomarker and we found that two hundred seventy-four DEGs were identified and enrichment analysis showed DEGs were involved in nervous system activity, like axon_guidance and the neurotrophin_signaling_pathway. Five nervous system-specific expressed hub genes were further validated by three GEO datasets. APP, LRRK2, and PSEN1 might be potential diagnostic and prognostic biomarkers of sALS, and NEAT1-miR-373-3p/miR-302c-3p/miR-372-3p-APP, circ_0000002-miR-302d-3p/miR-373-3p-APP and XIST-miR-9-5p/miR-30e-5p/miR-671-5p might be potential ceRNA regulatory pathways. APP SNP analysis showed subjects harboring the minor G allele of rs463946, minor G allele of rs466433 and minor C allele of rs364048 had an increased risk of sALS development. CONCLUSIONS: Our results identified three nervous system-specific expressed hub genes that might be diagnostic and prognostic markers of sALS and APP might be a genetic susceptibility factor contributing to sALS development.

Gene Expression Analysis Reveals Age and Ethnicity Signatures Between Young and Old Adults in Human PBMC.

Human immune system functions over an entire lifetime, yet how and why the immune system becomes less effective with age are not well understood. Here, we characterize peripheral blood mononuclear cell transcriptome from 132 healthy adults with 21-90 years of age using the weighted gene correlation network analyses. In our study, 113 Caucasian from the 10KIP database and RNA-seq data of 19 Asian (Chinese) are used to explore the differential co-expression genes in PBMC aging. These two dataset reveal a set of insightful gene expression modules and representative gene biomarkers for human immune system aging from Asian and Caucasian ancestry, respectively. Among them, the aging-specific modules may show an age-related gene expression variation spike around early-seventies. In addition, we find the top hub genes including NUDT7, CLPB, OXNAD1, and MLLT3 are shared between Asian and Caucasian aging related modules and further validated in human PBMCs from different age groups. Overall, the impact of age and race on transcriptional variation elucidated from this study may provide insights into the transcriptional driver of immune aging.

Tau knockout exacerbates degeneration of parvalbumin-positive neurons in substantia nigra pars reticulata in Parkinson's disease-related α-synuclein A53T mice.

α-Synuclein (α-syn)-induced neurotoxicity has been generally accepted as a key step in the pathogenesis of Parkinson's disease (PD). Microtubule-associated protein tau, which is considered second only to α-syn, has been repeatedly linked with PD in association studies. However, the underlying interaction between these two PD-related proteins in vivo remains unclear. To investigate how the expression of tau affects α-syn-induced neurodegeneration in vivo, we generated triple transgenic mice that overexpressed α-syn A53T mutation in the midbrain dopaminergic neurons (mDANs) with different expression levels of tau. Here, we found that tau had no significant effect on the A53T α-syn-mediated mDANs degeneration. However, tau knockout could modestly promote the formation of α-syn aggregates, accelerate the severe and progressive degeneration of parvalbumin-positive (PV+) neurons in substantia nigra pars reticulata (SNR), accompanied with anxiety-like behavior in aged PD-related α-syn A53T mice. The mechanisms may be associated with A53T α-syn-mediated specifically successive impairment of N-methyl-d-aspartate receptor subunit 2B (NR2B), postsynaptic density-95 (PSD-95) and microtubule-associated protein 1A (MAP1A) in PV+ neurons. Our study indicates that MAP1A may play a beneficial role in preserving the survival of PV+ neurons, and that inhibition of the impairment of NR2B/PSD-95/MAP1A pathway, may be a novel and preferential option to ameliorate α-syn-induced neurodegeneration.

Endovascular recanalization for symptomatic subacute and chronically occluded internal carotid artery: feasibility, safety, a modified radiographic classification system, and clinical outcomes.

PURPOSE: To evaluate the feasibility and safety of endovascular recanalization for symptomatic subacute and chronic internal carotid artery occlusion (ICAO); to propose a newly modified radiographic classification of ICAO that can rigorously identify suitable candidates for endovascular ICAO treatment. METHODS: We included 42 consecutive patients who had ICAO with ischaemic symptoms refractory to medical therapy. We examined the symptomatology, complications, follow-up results and radiographic images of ICAO receiving attempted endovascular treatment. We attempted to stratify all radiographic images into categories based on morphological occlusion patterns, occlusion segments and distal ICA reconstitution on digital subtraction angiography (DSA). RESULTS: Four types (A-D) of radiographic ICAO were identified. We redefined type B as having a tapered stump but no distal lumen. The rate of successful recanalization was 83.33% (35/42 ICAOs; type A, 18/20; type B, 7/10; type C, 10/11; type D, 0/1). The perioperative complication rate was 11.90% (5/42), including 3 asymptomatic distal embolisms, 1 symptomatic cerebral infarction and 1 asymptomatic carotid artery dissection. None of these technique-related complications led to severe neurological damage or death. Modified Rankin Scale (mRS) scores after 1-20 months of follow-up were significantly decreased in successfully revascularized patients (P < 0.001). There was no significant change in mRS scores in the 7 patients in whom recanalization failed (P > 0.05). CONCLUSIONS: Endovascular recanalization seems to achieve technical success and clinical improvement for symptomatic subacute and chronic ICAO. Additionally, our newly modified radiographic classification of ICAO may be valuable in assessing the technical feasibility and safety of procedures in symptomatic ICAO patients.

The adoptive transfer of BCG-induced T lymphocytes contributes to hippocampal cell proliferation and tempers anxiety-like behavior in immune deficient mice.

We previously have reported that neonatal Bacillus Calmette-Guerin (BCG) vaccination improves neurogenesis and behavior in early life through affecting the neuroimmune milieu in the brain, but it is uncertain whether activation phenotypes and functional changes in T lymphocytes shape brain development. Here, we studied the effects of BCG vaccination via the adoptive transfer of T lymphocytes from the BALB/c wild-type mice into naive mice. Our results show that mice adoptive BCG-induced lymphocytes (BCG->naive mice) showed anxiolytic and antidepressant-like performance when completing an elevated plus maze (EPM) test. Meanwhile, BCG->naive mice possess more cell proliferation and newborn neurons than PBS->naive and nude mice in the hippocampus. IFN-γ and IL-4 levels in the serum of BCG->naive mice also increased, while TNF-α and IL-1ß levels were reduced relative to those of PBS->naive and nude mice. We further found that BCG->naive mice showed different repartition of CD4+ and CD8+ T cell to naive (CD62L+CD44low), effector memory (CD62L-CD44hi), central memory (CD62L+CD44hi) and acute/activated effector (CD62L-CD44low) cells in the spleen. Importantly, the adoptive transfer of BCG-induced T lymphocytes infiltrated into the dura mater and brain parenchyma of the nude mice. Activation phenotypes and functional changes in T lymphocytes are very likely to affect the neuroimmune milieu in the brain, and alterations in ratios of splenic CD4+ and CD8+ memory T cells may affect the expression of correlative cytokines in the serum, accounting for our behavioral results. We conclude thus that the adoptive transfer of BCG-induced T lymphocytes contributes to hippocampal cell proliferation and tempers anxiety-like behavior in immune deficient mice. Our work shows that BCG vaccination improves hippocampal cell proliferation outcomes and behaviors, likely as a result of splenic effector/memory T lymphocytes regulating the neuroimmune niche in the brain.

Mild Cognitive Impairment Patients Have Higher Regulatory T-Cell Proportions Compared With Alzheimer's Disease-Related Dementia Patients.

Objectives: The role of neuroinflammation in the pathogenesis of Alzheimer's disease (AD) has attracted much attention recently. Regulatory T-cells (Tregs) play an important role in modulating inflammation. We aimed to explore the Treg-related immunosuppression status at different stages of AD. Methods: Thirty healthy control (HC) subjects, 26 patients with mild cognitive impairment (MCI), 30 patients with mild probable AD-related dementia, and 28 patients with moderate-to-severe probable AD-related dementia underwent detailed clinical history taking, structural MRI scanning, and neuropsychological assessment. Peripheral blood samples were taken to measure the percentage of CD4+CD25+CD127low/- Tregs by flow cytometry and the levels of interleukin (IL-10), interleukin (IL-35), and transforming growth factor ß (TGF-ß) by ELISA. Results: The percentage of Tregs in the blood of MCI patients was the highest (9.24%); there was a significant difference between patients with MCI and patients with probable AD-related dementia. The level of TGF-ß in patients with MCI (47.02 ng/ml) was significantly increased compared with patients with AD-related dementia. There were positive correlations between Treg percentage, IL-35, and Mini-mental state evaluation scores in patients with MCI and probable AD-related dementia. Conclusions: Patients with MCI have stronger Treg-related immunosuppression status compared with patients with probable AD-related dementia.

Immediate and late outcomes of stenting for severe extracranial internal carotid artery stenosis in octogenarian patients.

Background: Multiple studies suggest that internal carotid artery stenting can be performed safely in octogenarians with low periprocedural complication rates. However, great concern still exists as to whether these patients will gain long-term benefits from this procedure given their advanced age and uncertain life expectancy. We decided to conduct a retrospective study to determine short-and long-term clinical outcomes and to analyze survival duration in this population. Methods and Results: Sixty-nine consecutive elderly patients with either symptomatic or asymptomatic stenosis ≥70% underwent 86 procedures. Immediate and late outcomes, as well as survival data, were analyzed retrospectively. Mean age was 83.1 ± 2.7 years. Mean survival was 49.3 ± 10.1 months. A complete neurological assessment was obtained at 1 and 2 years in 100% of patients, at 3 years in 90.7% of patients and at 5 years in 84.8% of patients. Two major and one minor ischemic strokes occurred during the periprocedural period. No death, myocardial infarction or intracranial hemorrhage was recorded. The mean follow-up period was 55.4 ± 24.6 months. Four patients experienced a minimum of 1 year of follow-up, and the longest is 8 years. Among the patients with the longest follow-up time, 6 had ischemic strokes, of which 2 were fatal. In total, 17 deaths occurred. Four patients experienced dementia without stroke. Survival at 3 and 5 years was estimated to be 90% and 73%, respectively. Conclusion: This study demonstrated that stenting in octogenarians was safe and effective during the periprocedural period. Long-term follow-up showed a low rate of fatal and nonfatal stroke, and patients survived long enough to benefit from the procedure. However, it was associated with a relatively high rate of long-term event. Though carotid artery stenting is a minimally invasive procedure, it should still be performed with great caution and only in carefully selected patients. The present study suggested that in this age population, carotid artery stenting might be considered as a revascularization option.

Cystatin C promotes tau protein phosphorylation and causes microtubule instability by inhibiting intracellular turnover of GSK3ß in neurons.

In Alzheimer's disease (AD) tau protein hyperphosphorylation causes neurofibrillary tangle formation, microtubule instability and neurodegeneration. Determining the mechanism of tau hyperphosphorylation will provide a better understanding of AD pathology. Cystatin C (CysC) is a risk factor for late-onset AD and its level is upregulated in the brains of AD patients. The role of CysC is AD pathogenesis is not known. In this study, we found that CysC level is upregulated in 3xTg-AD mouse brain. We demonstrate that CysC does not affect cellular Aß production. However, when overexpressed in neuron (NGF-differentiated PC12 cells), CysC inhibits turnover of GSK3ß, promotes GSK3ß-catalyzed tau phosphorylation at Ser396/404 and causes microtubule instability. Our data provide a novel insight into the role of CysC in AD pathogenesis.

Tau Deficiency Down-Regulated Transcription Factor Orthodenticle Homeobox 2 Expression in the Dopaminergic Neurons in Ventral Tegmental Area and Caused No Obvious Motor Deficits in Mice.

Tau protein participates in microtubule stabilization, axonal transport, and protein trafficking. Loss of normal tau function will exert a negative effect. However, current knowledge on the impact of tau deficiency on the motor behavior and related neurobiological changes is controversial. In this study, we examined motor functions and analyzed several proteins implicated in the maintenance of midbrain dopaminergic (DA) neurons (mDANs) function of adult and aged tau+/+, tau+/-, tau-/- mice. We found tau deficiency could not induce significant motor disorders. However, we discovered lower expression levels of transcription factors Orthodenticle homeobox 2 (OTX2) of mDANs in older aged mice. Compared with age-matched tau+/+ mice, there were 54.1% lower (p = 0.0192) OTX2 protein (OTX2-fluorescence intensity) in VTA DA neurons of tau+/- mice and 43.6% lower (p = 0.0249) OTX2 protein in VTA DA neurons of tau-/- mice at 18 months old. Combined with the relevant reports, our results suggested that tau deficiency alone might not be enough to mimic the pathology of Parkinson's disease. However, OTX2 down-regulation indicates that mDANs of tau-deficient mice will be more sensitive to toxic damage from MPTP.

Baicalein blocks α-synuclein secretion from SN4741 cells and facilitates α-synuclein polymerization to big complex.

The secretion of α-synuclein (α-syn) acts as an essential driver in the propagation of synucleinopathies in brain. The clearance of extracellular α-syn or blockade of the cell-to-cell transmission of α-syn is a promising approach to prohibiting synucleinopathies propagation. Baicalein (BAI), a flavonoid from Chinese herb, has been reported to bind covalently to α-syn to inhibit α-syn fibrillation and degrade its fibrils. However, whether BAI inhibits α-syn secretion is unclear. Here we showed that BAI reduced α-syn in the media of dopaminergic cell lines (SN4741) overexpressing wild-type α-syn (W-syn) or A53T mutant type α-syn (A53T-syn), while increased α-syn expression in cell lysates, upregulated the cell viability and increased the ratio of LC3 II/LC3 I, the latter is an indicator reflects the macroautophagic level. Intriguingly, BAI did not clear extracellular α-syn directly but facilitated α-syn polymerization to big complex (over 72kDa), which revealed that BAI probably reduced α-syn transmission by facilitating α-syn polymerization to big complex. Taken together, BAI could be a potential drug to inhibit α-syn propagation among the neurons.

Changes in methylation patterns of multiple genes from peripheral blood leucocytes of Alzheimer's disease patients.

BACKGROUND: Efforts aiming at identifying biomarkers and corresponding methods for early diagnosis of Alzheimer's disease (AD) might be the most appropriate strategy to initiate promising new treatments and/or prevention of AD OBJECTIVE: The aim of our study is to assess the association of DNA methylation pattern of various leucocyte genes with AD pathogenesis in order to find potential biomarkers and corresponding methods for molecular diagnosis of AD. METHODS: DNA methylation level of various genes in AD patients and normal population were compared by bisulphite sequencing PCR and methylation-specific PCR (MSP). Furthermore, real-time PCR was used to explore the effects of DNA methylation on the expression of target genes. RESULTS: Results showed significant hypermethylation of mammalian orthologue of Sir2 (SIRT1) gene in AD patients compared with normal population. Meanwhile, changes in methylation level of SIRT1 gene between different severities of AD were also found. Specific primers were designed from the SIRT1 CpG islands to differentiate AD and control group by MSP method. Besides, significant demethylation of ß-amyloid precursor protein (APP) gene was observed in AD patients, whereas no difference was observed in other AD-related genes. Moreover, significant decrease in expression of SIRT1 gene and increase in expression of APP gene were also found in AD patients. In addition, the expression level of SIRT1/APP genes was associated with the severity, but not with the age or gender, of AD patients. CONCLUSION: SIRT1 and APP might be the interesting candidate biomarkers and valuable for clinical diagnosis or treatment of AD.

White matter damage of patients with Alzheimer's disease correlated with the decreased cognitive function.

Increasing evidence demonstrates that there is marked damage and dysfunction in the white matter in Alzheimer's disease (AD). The present study investigates the nature of white matter damage of patients with Alzheimer's disease with diffusion tensor magnetic resonance imaging (DTI) and analyses the relationship between the white matter damage and the cognition function. DTI, as well as T1 fluid attenuated inversion recovery (FLAIR) and T2-FLAIR, was performed on probable patients of Alzheimer's disease, and sex and age matched healthy volunteers to measure the fractional anisotropy (FA) and mean diffusivity (MD) in the genu and splenium of the corpus callosum, anterior and posterior limbs of the internal capsule, and the white matter of frontal, temporal, parietal, and occipital lobes. FA was lower in the splenium of corpus callosum, as well as in the white matter of the frontal, temporal, and parietal lobes from patients with Alzheimer's disease than in the corresponding region from healthy controls and was strongly positive correlated with MMSE scores, whereas FA appeared no different in the anterior and posterior limbs of internal capsule, occipital lobes white matter, and the genu of corpus callosum between the patients and healthy controls. MD was significantly higher in the splenium of corpus callosum and parietal lobes white matter from patients than in that those from healthy controls and was strongly negative correlated with MMSE scores, whereas MD in the anterior and posterior limbs of internal capsule, as well as in frontal, temporal, occipital lobes white matter and the genu of corpus callosum, was not different between the patients and healthy controls. The most prominent alteration of FA and MD was in the splenium of corpus callosum. Our results suggested that white matter of patients with Alzheimer's disease was selectively impaired and the extent of damage had a strong correlation with the cognitive function, and that selective impairment reflected the cortico-cortical and cortico-subcortical disconnections in the pathomechanism of Alzheimer's disease. The values of FA and MD in white matter, especially in the splenium of corpus callosum in AD patients, might be a more appropriate surrogate marker for monitoring the disease progression.