Evaluation of ferritin and TfR level in plasma neural-derived exosomes as potential markers of Parkinson's disease.

Introduction: Early diagnosis of Parkinson's disease (PD) remains challenging. It has been suggested that abnormal brain iron metabolism leads to excessive iron accumulation in PD, although the mechanism of iron deposition is not yet fully understood. Ferritin and transferrin receptor (TfR) are involved in iron metabolism, and the exosome pathway is one mechanism by which ferritin is transported and regulated. While the blood of healthy animals contains a plentiful supply of TfR-positive exosomes, no studies have examined ferritin and TfR in plasma neural-derived exosomes. Methods: Plasma exosomes were obtained from 43 patients with PD and 34 healthy controls. Neural-derived exosomes were isolated with anti-human L1CAM antibody immunoabsorption. Transmission electron microscopy and western blotting were used to identify the exosomes. ELISAs were used to quantify ferritin and TfR levels in plasma neural-derived exosomes of patients with PD and controls. Receivers operating characteristic (ROC) curves were applied to map the diagnostic accuracy of ferritin and TfR. Independent predictors of the disease were identified using logistic regression models. Results: Neural-derived exosomes exhibited the typical exosomal morphology and expressed the specific exosome marker CD63. Ferritin and TfR levels in plasma neural-derived exosomes were significantly higher in patients with PD than controls (406.46 ± 241.86 vs. 245.62 ± 165.47 ng/µg, P = 0.001 and 1728.94 ± 766.71 vs. 1153.92 ± 539.30 ng/µg, P < 0.001, respectively). There were significant positive correlations between ferritin and TfR levels in plasma neural-derived exosomes in control group, PD group and all the individuals (rs = 0.744, 0.700, and 0.752, respectively). The level of TfR was independently associated with the disease (adjusted odds ratio 1.002; 95% CI 1.000-1.003). ROC performances of ferritin, TfR, and their combination were moderate (0.730, 0.812, and 0.808, respectively). However, no relationship was found between the biomarkers and disease progression. Conclusion: It is hypothesized that ferritin and TfR in plasma neural-derived exosomes may be potential biomarkers for PD, and that they may participate in the mechanism of excessive iron deposition in PD.

Corrigendum: Evaluation of ferritin and TfR level in plasma neural-derived exosomes as potential markers of Parkinson's disease.

[This corrects the article DOI: 10.3389/fnagi.2023.1216905.].

Association between plasma immunoproteasome and 90-day prognosis after first-ever ischemic stroke.

Many blood biomarkers are reportedly helpful for predicting post-stroke cognitive impairment (PSCI), but no biomarkers are widely used in clinical practice. The purpose of this study was to investigate the association between the plasma immunoproteasome and patients' 90-day prognosis after first-ever acute ischemic stroke. In our prospective, single-center study, 259 patients with first-ever acute ischemic stroke were enrolled from the Department of Neurology, Fujian Provincial Hospital, China, from March to September 2014. Of these, 27 patients (10.4%) had unfavorable outcomes as assessed by the Modified Rankin Scale (scores of 3-6). The National Institutes of Health Stroke Scale score on admission, plasma N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) levels, and immunopro-teasome subunit (low molecular mass peptide [LMP]2, LMP5, and LMP7) levels were significantly higher in the unfavorable outcome group than in the favorable outcome group. To predict unfavorable outcomes, the optimal cutoff points were National Institutes of Health Stroke Scale score > 12, NT-pro-BNP level > 1883.5 pg/mL, and LMP2 level > 841.4 pg/mL. Of the 193 patients that were able to complete the Mini-Mental State Examination at 90 days post-stroke, 66 patients (34.2%) had PSCI. Plasma levels of NT-pro-BNP and LMP2 were higher in patients with PSCI than in those without PSCI. To predict PSCI, the optimal cutoff values were age > 70.5 years and LMP2 level > 630.5 pg/mL. These findings indicate that plasma LMP2 may serve as a new prognostic biomarker of poor outcome and PSCI at 90 days after stroke. This study was approved by the Ethics Committee of Fujian Provincial Hospital, Provincial Clinical Medical College of Fujian Medical University (approval No. K2014-01-003) on January 15, 2014.

Inhibition of the immunoproteasome LMP2 ameliorates ischemia/hypoxia-induced blood-brain barrier injury through the Wnt/ß-catenin signalling pathway.

BACKGROUND: Disruption of the blood-brain barrier (BBB) after a stroke can lead to brain injury and neurological impairment. Previous work confirmed the involvement of the immunoproteasome subunit of low molecular mass peptide 2 (LMP2) in the pathophysiology of ischemia stroke. However, the relationship between the immunoproteasome LMP2 and the BBB remains unclear. METHODS: Adult male Sprague-Dawley rats were subjected to transient middle cerebral artery occlusion/reperfusion (MCAO/R). Three days before MCAO, the rats were treated with lentivirus-mediated LMP2 shRNA preparations by stereotactical injection into the ipsilateral hemispheric region. The rat brain microvascular endothelial cell (RBMVEC) line was exposed to oxygen-glucose deprivation/reperfusion (OGD/R) to mimic ischemic conditions in vitro. The RNA interference-mediated knockdown of LMP2 or ß-catenin was analysed in vivo and in vitro. Analysis of the quantity of extravasated Evans blue (EB) and cerebral fluorescent angiography were performed to evaluate the integrity of the BBB. Immunofluorescence and Western blotting were employed to detect the expression of target proteins. Cell migration was evaluated using a scratch migration assay. The results of immunofluorescence, Western blotting and cell migration were quantified using the software ImageJ (Version 1.53m). Parametric data from different groups were compared using one-way ANOVA followed by the least significant difference (LSD) test. RESULTS: Cerebral ischemia led to lower levels of structural components of the BBB such as tight junction proteins (occludin, claudin-1 and ZO-1) in the MCAO/R group compared with the sham group (P < 0.001). However, inhibition of the immunoproteasome LMP2 restored the expression of these proteins, resulting in higher levels of occludin, claudin-1 and ZO-1 in the LMP2-shRNA group compared with the control-shRNA group (P < 0.001). In addition, inhibition of the immunoproteasome LMP2 contributed to higher microvascular density and decreased BBB permeability [e.g., the quantity of extravasated EB: LMP2-shRNA group (58.54 ± 7.37) µg/g vs. control-shRNA group (103.74 ± 4.32) µg/g, P < 0.001], and promoted the upregulation of Wnt-3a and ß-catenin proteins in rats following MCAO/R. In vitro experiments, OGD/R induced marked upregulation of LMP2, proapoptotic protein Bax and cleaved caspase-3, and downregulation of occludin, claudin-1, ZO-1 and Bcl-2, as well as inhibition of the Wnt/ß-catenin pathway Wnt-3a and ß-catenin proteins in RBMVECs, compared with the control group under normal culture conditions (P < 0.001). However, silencing of LMP2 gene expression reversed these protein changes and promoted proliferation and migration of RBMVECs following OGD/R. Silencing of ß-catenin by transfection of RBMVECs with ß-catenin-siRNA aggravated the downregulation of tight junction proteins, and reduced the proliferation and migration of RBMVECs following OGD/R, compared with the control-siRNA group (P < 0.001). LMP2-siRNA and ß-catenin-siRNA co-transfection partly counteracted the beneficial effects of silencing LMP2-siRNA on the levels of tight junction proteins in RBMVECs exposed to OGD/R. CONCLUSION: This study suggests that inhibition of the immunoproteasome LMP2 ameliorates ischemia/hypoxia-induced BBB injury, and that the molecular mechanism involves the immunoproteasome-regulated activation of the Wnt/ß-catenin signalling pathway under ischemic conditions.

Human urinary kallidinogenase in acute ischemic stroke: A single-arm, multicenter, phase IV study (RESK study).

AIMS: Human urinary kallidinogenase (HUK) has shown favorable efficacies in acute ischemic stroke (AIS) treatment. We sought confirmation of the safety and efficacy of HUK for AIS in a large population. METHODS: RESK study enrolled patients with AIS of anterior circulation to receive HUK infusion. The primary endpoint was the incidence of treatment-emergent adverse events (AEs). Secondary endpoints assessed neurological and functional improvements and stroke recurrent rate. RESULTS: Of 1206 eligible patients, 1202 patients received at least one dose of HUK infusion and 983 (81.5%) completed the study. The incidence of treatment-emergent AEs and serious AEs were 55.99% and 2.41%, respectively. Pre-specified AEs of special interest occurred in 21.71% of patients, but the majority were mild and unrelated to therapy. Hypertension, age, treatment time, and drug combination were identified to be associated with drug-related blood pressure reduction. Neurological and functional evaluations revealed favorable outcomes from baseline to post-treatment assessment. The cumulative recurrence rate of stroke was 2.50% during the 90-day assessment. CONCLUSION: HUK had an acceptable safety and tolerability profile in AIS patients. Besides, HUK demonstrated the neurological and functional improvements in AIS, further confirming its clinical efficacy in a real-world large population.

A Chinese pedigree with a novel mutation in GJB1 gene and a rare variation in DHTKD1 gene for diverse Charcot­Marie­Tooth diseases.

Charcot­Marie­Tooth (CMT) disease is a group of motor and sensory neuropathies with a high degree of pathological and genetic heterogenicity. The present study described 2 patients with CMT in a Chinese Han pedigree. The proband exhibited the classic manifestation of CMT with slowly progressing muscular atrophy and weakness. Electrophysiological examination highlighted axonal and demyelinating features. His mother did not have any symptoms, but did exhibit abnormal electrophysiological results. Next­generation sequencing technology was employed to screen mutations in the genes associated with inherited motor never diseases. A novel mutation, c.528_530delAGT, in the gap junction protein beta 1 (GJB1) gene for CMTX, and a rare variation, c.2369C>T, in the dehydrogenase E1 and transketolase domain containing 1 (DHTKD1) gene for CMT disease type 2Q (CMT2Q), were identified in the proband and his mother. The results were verified by Sanger sequencing. Although the in silico analysis predicted no change in the 3­dimensional structure, the clinical and electrophysiological presentation in the pedigree and the high evolutionary conservation of the affected amino acid supported the hypothesis that the c.528_530delAGT mutation in the GJB1 gene may be pathogenic in this pedigree. In silico analysis and high evolutionary conservation suggested the pathogenicity of the c.2369C>T mutation in the DHTKD1 gene; however, the clinical and electrophysiological performances of the proband and his mother did not conform to those of CMT2Q caused by the DHTKD1 gene. The present study provided additional information concerning the range of mutations of the GJB1 gene, which facilitated the understanding of the genotype­phenotype association of CMT.

Increased DJ-1 and α-Synuclein in Plasma Neural-Derived Exosomes as Potential Markers for Parkinson's Disease.

The diagnosis of PD might be in difficulty, especially in the early stages. Therefore, the identification of novel biomarkers is imperative for the diagnosis and monitoring disease progression in PD. DJ-1 and α-synuclein, are two proteins that are critically involved in the pathogenesis of PD, and they have been examined as disease biomarkers in studies. However, no study exists regarding DJ-1 in plasma neural-derived exosomes. In the present study, the levels of DJ-1 and α-synuclein in plasma neural-derived exosomes were studied together in order to investigate novel biomarkers for PD. DJ-1 and α-synuclein in plasma and plasma neural-derived exosomes of the patients with PD and controls were quantified by ELISAs. The data revealed that the levels of DJ-1 and α-synuclein in plasma neural-derived exosomes and the ratio of plasma neural-derived exosomal DJ-1 to total DJ-1 were significantly higher in patients with PD, compared with controls, while levels of the two proteins in plasma exhibited no difference between the patients with PD and controls. However, no relationship was identified between biomarkers and disease progression. In addition, significant positive correlations between DJ-1 and α-synuclein in plasma neural-derived exosomes were found in the patients with PD and in healthy individuals. We hypothesize that DJ-1 in plasma neural-derived exosomes may be used as a potential biomarker as α-synuclein in PD and they might participate in the mechanism of PD together.

Interactions between ACYP2 genetic polymorphisms and environment factors with susceptibility to ischemic stroke in a Han Chinese Population.

AIMS: To investigate the association of several single nucleotide polymorphisms (SNPs) within ACYP2 gene and additional gene- environment interaction with ischemic stroke (IS) risk in a Chinese population. RESULTS: IS risk was significantly higher in carriers with the G allele of rs11896604 than those with CC genotype (CG or GG versus CC), adjusted OR (95%CI) =1.60 (1.18-2.20), and higher in carriers with the A allele of rs12615793 than those with GG genotype (GA or AA versus GG), adjusted OR (95%CI) = 1.66 (1.24-2.15). GMDR model shown a significant two-locus model (p = 0.0010) involving rs11896604 and alcohol drinking, and a significant two-locus model (p = 0.0010) involving rs12615793 and smoking. Current smokers with rs12615793- GA or AA genotype have the highest IS risk, compared to never- smokers with rs12615793-GG genotype, OR (95%CI) = 2.72 (1.64-3.86); current drinkers with rs11896604-CG or GG genotype have the highest IS risk, compared to never- drinkers with rs11896604-CC genotype, OR (95%CI) = 2.51 (1.70-3.40). MATERIALS AND METHODS: A total of 1202 participants (660 males, 542 females) were selected, including 600 IS patients and 602 control participants. The mean age of all participants was 68.2 ± 15.8 years. Generalized multifactor dimensionality reduction (GMDR) was used to screen the best interaction combination. Logistic regression was performed to investigate the impact of 4 SNPs within ACYP2 gene, additional gene-smoking or drinking interaction on IS risk. CONCLUSIONS: We found that the G allele of rs11896604 and the A allele of rs12615793 within ACYP2 gene, rs12615793- smoking interaction, and rs11896604-alcohol drinking interaction were all associated with increased IS risk.

Matrix metalloproteinase 9 level as an indicator for restenosis following cervical and intracranial angioplasty and stenting.

Cervical and intracranial angioplasty and stenting is an effective and safe method of reducing the risk of ischemic stroke, but it may be affected by in-stent restenosis. The present study investigated serum level of matrix metalloproteinase 9 as a predictor of restenosis after 40 patients underwent cervical and/or intracranial angioplasty and stenting. Results showed that restenosis occurred in 30% (3/10) of patients when the serum level of matrix metalloproteinase 9 at 3 days after surgery was 2.5 times higher than preoperative level. No restenosis occurred when the serum level of matrix metalloproteinase 9 at 3 days after surgery was not 2.5 times higher than preoperative level. Restenosis occurred in 12% (2/17) of patients when the serum level of matrix metalloproteinase 9 was higher than preoperative level for more than 30 days after surgery, but only occurred in 4% (1/23) of patients when the serum level of matrix metalloproteinase 9 was higher than preoperative level for less than 30 days after surgery. However, the differences observed were not statistically significant (P > 0.05). Experimental findings indicate that when the serum level of matrix metalloproteinase 9 is 2.5 times higher than preoperative level at 3 days after cervical and intracranial angioplasty and stenting, it may serve as a predictor of in-stent restenosis.

[Prevalence of dementia among rural elderly in Gushan township, Fuzhou].

OBJECTIVE: To study the prevalence of dementia and its related risk factors in people aged 65 years and older in Gushan township. METHODS: People aged 65 years or older in 22 villages of Gushan township were screened, from July 2007 to November 2007. Face to face interview with mini-mental state examination, and followed by clinical assessment. A series of neuropsychological examination was done on selected subjects based on the results of the screening tests. Clinical diagnosis on dementia was made according to the Diagnosis and Statistical Manual of Mental Disorder Fourth Edition. RESULTS: Out of the 2913 people 2696 aged 65 years or older, were enrolled. Among the participants, 197 were confirmed of having dementia, accounting for the overall rate as 7.3%. The prevalence rate of dementia was 5.1% in males and 8.9% in females. Prevalence of dementia in the highly educated intellectuals was 9.2%, followed by 5.2%, 3.9% and 2.5% in those having received primary, junior high or senior high school education. Results from logistic regression analysis showed that the major risk factors which influencing the prevalence of dementia would include age, activies of daily living, marital status, monthly income, frequency in watching TV/movie/field show, poker player or tress and taking care of the family etc. CONCLUSION: The prevalence rate of dementia went up along with age. Factors as watching TV/movie/field show or playing poker/chess more frequently, as well as taking good care on families tend to help reduce or postpone the development of dementia.