Surface protein profiling and subtyping of extracellular vesicles in body fluids reveals non-CSF biomarkers of Alzheimer's disease.

Noninvasive and effortless diagnosis of Alzheimer's disease (AD) remains challenging. Here we report the multiplexed profiling of extracellular vesicle (EV) surface proteins at the single EV level in five types of easily accessible body fluids using a proximity barcoding assay (PBA). A total of 183 surface proteins were detected on the EVs from body fluids collected from APP/PS1 transgenic mice and patients with AD. The AD-associated differentially expressed EV proteins could discriminate between the control and AD/AD model samples with high accuracy. Based on machine learning predictive models, urinary EV proteins exhibited the highest diagnostic potential compared to those on other biofluid EVs, both in mice and humans. Single EV analysis further revealed AD-associated EV subpopulations in the tested body fluids, and a urinary EV subpopulation with the signature proteins PLAU, ITGAX and ANXA1 could diagnose patients with AD in blinded datasets with 88% accuracy. Our results suggest that EVs and their subpopulations from noninvasive body fluids, particularly urine, are potential diagnostic biomarkers for AD.

Prevalence and clinical correlates of hyperhomocysteinemia in Chinese urban population with hypertension.

Context: The coexistence of hypertension and elevated homocysteine (Hcy) levels has a mutually reinforcing impact on the susceptibility to cardio-cerebrovascular disease. Objective: The aim was to assess the prevalence, clinical correlation, and demographic characteristics of hyperhomocysteinemia (HHcy) within the Chinese urban population with hypertension. Methods: A cohort of 473 individuals with hypertension were selected from four communities in Shenzhen, China. Demographic attributes, clinical profiles, and lifestyle behaviors were gathered and compared between individuals with and without HHcy. A logistic regression model was employed to examine potential factors associated with the prevalence of HHcy. Correlation between Hcy levels and clinical characteristics was assessed through multiple linear regression analysis. Results: The prevalence of HHcy in the population with hypertension was 31.3%. In comparison to individuals without HHcy, those with HHcy exhibited a higher proportion of males, a higher prevalence of smoking and alcohol consumption, and a higher proportion of cases with the homozygous (TT) genotype at the MTHFR C677T polymorphism. Moreover, individuals with HHcy had lower levels of folic acid (FA), and lower fruit and vitamin B12 intake. Furthermore, the risk factors for HHcy were male (B = 1.430, OR = 4.179) and MTHFR (TT) (B = 1.086, OR = 2.961). In addition, the multiple linear regression analysis revealed a significant association between Hcy levels and gender (B = -2.784, P = 0.004), MTHFR genotypes (B = 1.410, P = 0.005), and FA levels (B = -0.136, P = 0.030). Conclusion: The high prevalence of HHcy among hypertensive patients in this Chinese urban population underscores the necessity for interventions targeting modifiable risk factors such as dietary choices and lifestyle practices.

Alterations in HCN1 expression and distribution during epileptogenesis in rats.

BACKGROUND: The hyperpolarization-activated cyclic nucleotide-gated cation channel (HCN1) is predominantly located in key regions associated with epilepsy, such as the neocortex and hippocampus. Under normal physiological conditions, HCN1 plays a crucial role in the excitatory and inhibitory regulation of neuronal networks. In temporal lobe epilepsy, the expression of HCN1 is decreased in the hippocampi of both animal models and patients. However, whether HCN1 expression changes during epileptogenesis preceding spontaneous seizures remains unclear. OBJECTIVE: The aim of this study was to determine whether the expression of HCN1 is altered during the epileptic prodromal phase, thereby providing evidence for its role in epileptogenesis. METHODS: We utilized a cobalt wire-induced rat epilepsy model to observe changes in HCN1 during epileptogenesis and epilepsy. Additionally, we also compared HCN1 alterations in epileptogenic tissues between cobalt wire- and pilocarpine-induced epilepsy rat models. Long-term video EEG recordings were used to confirm seizures development. Transcriptional changes, translation, and distribution of HCN1 were assessed using high-throughput transcriptome sequencing, total protein extraction, membrane and cytoplasmic protein fractionation, western blotting, immunohistochemistry, and immunofluorescence techniques. RESULTS: In the cobalt wire-induced rat epilepsy model during the epileptogenesis phase, total HCN1 mRNA and protein levels were downregulated. Specifically, the membrane expression of HCN1 was decreased, whereas cytoplasmic HCN1 expression showed no significant change. The distribution of HCN1 in the distal dendrites of neurons decreased. During the epilepsy period, similar HCN1 alterations were observed in the neocortex of rats with cobalt wire-induced epilepsy and hippocampus of rats with lithium pilocarpine-induced epilepsy, including downregulation of mRNA levels, decreased total protein expression, decreased membrane expression, and decreased distal dendrite expression. CONCLUSIONS: Alterations in HCN1 expression and distribution are involved in epileptogenesis beyond their association with seizure occurrence. Similarities in HCN1 alterations observed in epileptogenesis-related tissues from different models suggest a shared pathophysiological pathway in epileptogenesis involving HCN1 dysregulation. Therefore, the upregulation of HCN1 expression in neurons, maintenance of the HCN1 membrane, and distal dendrite distribution in neurons may represent promising disease-modifying strategies in epilepsy.

The association between circulating fatty acids and stroke in hypertensive patients.

BACKGROUND: Stroke is prevalent in hypertensive population. It has been suggested that unsaturated fatty acids (USFA) have protective effect on stroke. The effect of saturated fatty acids (SFAs) on stroke is still unclear. Therefore, we studied the relationship between circulating fatty acids and acute ischemic stroke (AIS) in hypertensive patients. METHODS: Eighty-nine pairs including 100 men and 78 women matched by sex and age were recruited. Each pair included a hypertensive patient within 48h of AIS onset and a hypertensive patient without stroke. Six circulating fatty acids were methylated before concentration determination which was repeated twice with percent recovery estimated. RESULTS: There were differences in educational level (P = 0.002) and occupation (P < 0.001) between stroke and non-stroke participants. All the 6 fatty acid levels were higher in non-stroke participants (P = 0.017 for palmitoleic acid, 0.001 for palmitic acid, <0.001 for linoleic acid, <0.001 for behenic acid, <0.001 for nervonic acid and 0.002 for lignoceric acid). In logistic regression analysis, AIS was inversely associated with fatty acid levels except for lignoceric acid. After adjustment for education and occupation, the palmitoleic acid and palmitic acid levels were no longer inversely associated with AIS. After further adjustment for systolic blood pressure, smoking, drinking, total cholesterol and triglyceride, the inverse associations of linoleic acid (OR = 0.965, 95%CI = 0.942-0.990, P = 0.005), behenic acid (OR = 0.778, 95%CI = 0.664-0.939, P = 0.009), nervonic acid (OR = 0.323, 95%CI = 0.121-0.860, P = 0.024) with AIS remained significant. CONCLUSIONS: Circulating fatty acids except lignoceric acid were inversely associated with AIS. Both USFAs and SFAs may have beneficial effect on stroke prevention in hypertensive population.

Role of m6A RNA Methylation in Ischemic Stroke.

Ischemic stroke is a prominent contributor to global morbidity and mortality rates. The intricate and diverse mechanisms underlying ischemia-reperfusion injury remain poorly comprehended. RNA methylation, an emerging epigenetic modification, plays a crucial role in regulating numerous biological processes, including immunity, DNA damage response, tumorigenesis, metastasis, stem cell renewal, adipocyte differentiation, circadian rhythms, cellular development and differentiation, and cell division. Among the various RNA modifications, N6-methyladenosine (m6A) modification stands as the most prevalent in mammalian mRNA. Recent studies have demonstrated the crucial involvement of m6A modification in the pathophysiological progression of ischemic stroke. This review aims to elucidate the advancements in ischemic stroke-specific investigations pertaining to m6A modification, consolidate the underlying mechanisms implicated in the participation of m6A modification during the onset of ischemic stroke, and deliberate on the potential of m6A modification as a viable therapeutic target for ischemic stroke.

Identification of novel biomarkers and immune infiltration characteristics of ischemic stroke based on comprehensive bioinformatic analysis and machine learning.

Background: Ischemic stroke (IS) is one of most common causes of disability in adults worldwide. However, there is still a lack of effective and reliable diagnostic markers and therapeutic targets in IS. Furthermore, immune cell dysfunction plays an important role in the pathogenesis of IS. Hence, in-depth research on immune-related targets in progressive IS is urgently needed. Methods: Expression profile data from patients with IS were downloaded from the Gene Expression Omnibus (GEO) database. Then, differential expression analysis and weighted gene coexpression network analysis (WGCNA) were performed to identify the significant modules and differentially expressed genes (DEGs). Key genes were obtained and used in functional enrichment analyses by overlapping module genes and DEGs. Next, hub candidate genes were identified by utilizing three machine learning algorithms: least absolute shrinkage and selection operator (LASSO), random forest, and support vector machine-recursive feature elimination (SVM-RFE). Subsequently, a diagnostic model was constructed based on the hub genes, and receiver operating characteristic (ROC) curves were constructed to validate the performances of the predictive models and candidate genes. Finally, the immune cell infiltration landscape of IS was explored with the CIBERSORT deconvolution algorithm. Results: A total of 40 key DEGs were identified based on the intersection of the DEGs and module genes, and we found that these genes were mainly enriched in the regulation of lipolysis in adipocytes, neutrophil extracellular trap formation and complement and coagulation cascades. Based on the results from three advanced machine learning algorithms, we obtained 7 hub candidate genes (ABCA1, ARG1, C5AR1, CKAP4, HMFN0839, SDCBP and TLN1) as diagnostic biomarkers of IS and developed a reliable nomogram with high predictive performance (AUC = 0.987). In addition, immune cell infiltration dysregulation was implicated in IS, and compared with those in the normal group, IS patients had increased fractions of gamma delta T cells, monocytes, M0 macrophages, M2 macrophages and neutrophils and clearly lower percentages of naive B cells, CD8 T cells, CD4+ memory T cells, follicular helper T cells, regulatory T cells (Tregs) and resting dendritic cells. Furthermore, correlation analysis indicated a significant correlation between the hub genes and immune cells in progressive IS. Conclusion: In conclusion, our study identified 7 hub genes as diagnostic biomarkers and established a reliable model to predict the occurrence of IS. Meanwhile, we explored the immune cell infiltration pattern and investigated the relationship between candidate genes and immune cells in the pathogenesis of IS. Hence, our study provides new insights into the diagnosis and treatment of IS.

Post-transfusion severe headache in a patient with thalassemia with superficial siderosis of the central nervous system: a case report and literature review.

BACKGROUND: Patients with severe thalassemia may experience adverse effects from transfusion such as fever, rash, and iron overload after long-term transfusion therapy. Severe headaches as a side effect of blood transfusion in patients with thalassemia are not commonly observed, especially when combined with superficial siderosis of the central nervous system, which is easily misdiagnosed and requires excessive examination and treatment. CASE PRESENTATION: A 31-year-old woman was admitted with severe headache and vomiting over 3 days following blood transfusion. She was diagnosed with intermediate α-thalassemia at 2 years of age and had a history of irregular blood transfusions. Physical examination revealed horizontal nystagmus with no other abnormal neurological signs. Magnetic resonance (MR) imaging, MR venography, MR arteriography, and cerebrospinal fluid analysis were normal. However, susceptibility-weighted imaging showed abnormal signals in the bilateral and fourth ventricles. Initial antibiotics, antivirals, decompression of intracranial pressure, iron chelation, and symptomatic treatments were administered; subsequently, small intermittent blood transfusions were cautiously administered for severe anemia. The patient's headache was gradually relieved, and she was discharged on day 9. At the 5-month follow-up, the patient's headache recurred following another transfusion. CONCLUSIONS: Severe post-transfusion headache in patients with thalassemia has not been fully recognized and is easily misdiagnosed, leading to excessive examination and treatment. Understanding the clinical features of transfusion-related headaches can help identify this complication, but the exact pathophysiological mechanism requires further research.

Effects of intravenous rtPA in patients with minor stroke.

BACKGROUND: Whether minor ischemic stroke (MIS) patients can benefit from intravenous thrombolysis (IVT) remains controversial. The association between the efficacy of IVT and baseline National Institute of Health Stroke Scale (NIHSS) score is unclear in MIS, while the association in moderate and severe stroke is known. This study aimed to explore the effect of IVT in patients with MIS and analyze its efficacy in patients with different baseline NIHSS scores. METHODS: Patients with a NIHSS score ≤5 within 4.5 h of stroke onset were screened in 32 centers. Patients with and without IVT were matched to a ratio of 1:1 with propensity scores. An excellent outcome was defined as a modified Rankin Scale (mRS) score ≤1 at three months after stroke onset. Safety outcomes included mortality and symptomatic intracranial hemorrhage (sICH). Multivariate analysis was used to compute the adjusted odds ratio (OR) for excellent outcomes. The effect of IVT was further analyzed in subgroups according to the baseline NIHSS score. RESULTS: Of the 23,853 screened, 3336 patients with MIS who arrived at the hospital within 4.5 h of onset were included. The 1163 patients treated with IVT were matched with 1163 patients without IVT. IVT in minor strokes generated an adjusted OR of 1.38 (95% CI: 1.09-1.75, p = 0.009) for excellent outcomes. There were no significant differences in mortality (0.17% vs. 0.09%, p = 1.000) and sICH (0.69% vs. 0.86%, p = 0.813) between patients with and without IVT. Subgroup analysis showed that there was no significant effect of IVT in the baseline NIHSS 0-1 or 2-3 subgroups, with adjusted OR of 0.816 (95% CI 0.437-1.53, p = 0.525) and1.22 (95% CI 0.845-1.77, p = 0.287), respectively. In patients with NIHSS score of 4-5, IVT was significantly effective, with an adjusted OR of 1.53 (95% CI 1.02-2.30, p = 0.038). CONCLUSION: IVT can improve MIS outcomes. The risks of sICH and mortality did not increase, especially in patients with NIHSS scores 4 to 5, who could benefit from IVT significantly.

Overall, intravenous thrombolysis can improve the outcomes of patients with minor stroke.Minor stroke patients with a baseline NIHSS score of 4-5 can benefit the most from intravenous thrombolysis.

Emerging roles and mechanism of m6A methylation in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a multifaceted autoimmune disease characterized by systemic inflammation, affecting both articular and extra-articular structures. This condition results in inflammation of joints and synovial membranes, accompanied by the development of systemic comorbidities. Despite extensive research, the precise pathogenic mechanisms responsible for RA have yet to be completely understood. RNA methylation, a burgeoning epigenetic alteration, assumes a pivotal function in the regulation of a myriad of biological phenomena, encompassing immunity, DNA damage response, tumorigenesis, metastasis, stem cell renewal, adipocyte differentiation, circadian rhythms, cellular development and differentiation, and cell division. The N6-methyladenosine (m6A) modification is the most prevalent among the various RNA modifications found in mammalian mRNA. Recent studies have provided evidence of the significant role played by m6A modification in the pathophysiological progression of RA. This review aims to provide a comprehensive analysis of the progress made in research focused on m6A modification in the context of RA, consolidate the underlying mechanisms involved in m6A modification during the initiation of RA and discuss the potential of targeting m6A modification as a viable therapeutic approach for RA.

Case report: GCA like picture-preceding inaugural MOGAD presentation: A patient with a sudden-onset uniocular blindness.

RATIONALE: Myelin oligodendrocyte glycoprotein antibody-associated disorders (MOGAD) represents a demyelinating neurological syndrome characterized by the presence of serum IgG antibodies directed against myelin oligodendrocyte glycoprotein (MOG-IgG). Concurrently, giant cell arteritis (GCA) constitutes a systemic autoimmune vasculitis. PATIENT CONCERNS: In this case, we describe an elderly female patient who presented with the sudden onset of a severe headache, unilateral blindness, and clinical manifestations resembling those of GCA. DIAGNOSIS: Upon conducting a comprehensive analysis of serum antibodies, the diagnosis of MOGAD was established due to the presence of detectable serum MOG-IgG. INTERVENTIONS: Subsequently, the patient was administered intravenous methylprednisolone therapy, commencing 27 days after the initial onset of symptoms. OUTCOMES: It is noteworthy that patients afflicted by MOGAD typically manifest severe visual impairment, which, in many instances, exhibits significant improvement following immunotherapeutic interventions. However, this particular patient did not experience any amelioration in visual function despite glucocorticoid therapy. LESSONS: This unique case illustrates that the clinical presentation resembling GCA may precede the inaugural manifestation of MOGAD. This suggests the possibility of immune-mediated arterial involvement. The significance of glucocorticoid therapy in the context of immune-related diseases warrants further scrutiny, particularly in cases where MOG-IgG screening should be promptly considered.

Examining the Role of GLU/GABA to GLN Metabolic Cycle in the Pathogenesis of Post-Stroke Depressive Disorder and Insomnia.

Objective: This study aims to elucidate the potential links between the GLU/GABA to GLN metabolic cycle disruptions and the onset of depressive and insomnia disorders following a stroke. We particularly focus on understanding if these disorders share a common underlying pathogenic mechanism. Methods: We examined 63 patients with post-stroke insomnia, 62 patients with post-stroke depression, and 18 healthy individuals. The study involved assessing insomnia using the Acute Insomnia Scale (AIS) and depression using the Hamilton Depression Rating Scale. We measured serum concentrations of GLN, GLU, and GABA and analyzed their correlations with AIS and HAMD scores. Results: Our results indicate no significant difference in the serum levels of GLN, GLU, and GABA between the post-stroke insomnia and depression groups. However, these levels were notably lower in both patient groups compared to the healthy control group. A negative correlation between AIS scores and GABA levels was observed in the post-stroke insomnia group, suggesting a potential link between GABAergic disturbances and insomnia. Conversely, no significant correlation was found between Hamilton Depression Rating Scale scores and the levels of GABA, GLU, or GLN in the post-stroke depression group. Conclusion: The study highlights that abnormalities in the GLU/GABA to GLN metabolic cycle, particularly the levels of GLN, GABA, and GAD, might be intricately linked to the pathogenesis of post-stroke insomnia and depression. Our findings suggest that GABAergic imbalances could be indicative of post-stroke insomnia, serving as potential biological markers for differential diagnosis in clinical settings. Further research is warranted to explore these relationships in greater depth, potentially leading to new diagnostic and therapeutic approaches for post-stroke neuropsychiatric disorders.

Near-Infrared Afterglow ONOO--Triggered Nanoparticles for Real-Time Monitoring and Treatment of Early Ischemic Stroke.

Early detection and drug intervention with the appropriate timing and dosage are the main clinical challenges for ischemic stroke (IS) treatment. The conventional therapeutic agents relay fluorescent signals, which require real-time external light excitation, thereby leading to inevitable autofluorescence and poor tissue penetration. Herein, we report endogenous peroxynitrite (ONOO-)-activated BDP-4/Cur-CL NPs that release NIR afterglow signals (λmax 697 nm) for real-time monitoring of the progression of ischemia reperfusion (I/R) brain injury while releasing curcumin for the safe treatment of IS. The BDP-4/Cur-CL NPs exhibited bright NIR afterglow luminescence (maximum 732-fold increase), superb sensitivity (LOD = 82.67 nM), high energy-transfer efficiency (94.6%), deep tissue penetration (20 mm), outstanding antiapoptosis, and anti-inflammatory effects. The activated NIR afterglow signal obtained in mice with middle cerebral artery occlusion (MCAO) showed three functions: (i) the BDP-4/Cur-CL NPs are rapidly activated by endogenous ONOO-, instantly illuminating the lesion area, distinguishing I/R damage from normal areas, which can be successfully used for endogenous ONOO- detection in the early stage of IS; (ii) real-time reporting of in situ generation and dynamic fluctuations of endogenous ONOO- levels in the lesion area, which is of great value in monitoring the evolutionary mechanisms of IS; and (iii) dynamic monitoring of the release of curcumin drug for safe treatment. Indeed, the released curcumin effectively decreased apoptosis, enhanced survival, alleviated neuroinflammation, reduced brain tissue loss, and improved the cognition of MCAO stroke mice. This work is the first example of afterglow luminescence for early diagnosis, real-time reporting, drug tracing, and treatment for IS.

An investigation on the changes of serum CCK-8, substance P, and 5-HT in patients with post-stroke insomnia.

BACKGROUND: At present, the pathogenesis of post-stroke insomnia (PSI) is still inconclusive. OBJECTIVE: To explore the changes and significance of serum cholecystokinin-8 (CCK-8), substance P (SP), and 5-hydroxytryptamine (5-HT) in patients with PSI. METHODS: Ninety-one patients with stroke were selected as the research subjects, and according to the score of the Athens Insomnia Scale (AIS), they were divided into the insomnia group and the non-insomnia group. The serum levels of CCK-8, SP, and 5-HT in the two groups were compared to explore their relationships with PSI. RESULTS: Among the 91 patients, 56 were in the insomnia group and 35 were in the non-insomnia group, and the incidence of insomnia was 61.5%. There was no significant difference in the serum levels of CCK-8, SP, and 5-HT between the two groups (P= 0.696, 0.980, and 0.809, respectively). One-way analysis of variance showed that there was no significant correlation between the serum levels of CCK-8, SP, 5-HT, and the AIS score (P= 0.7393, 0.9581, and 0.5952, respectively). CONCLUSION: The incidence of PSI was relatively high, but it could not be proved that CCK-8, SP, and 5-HT were involved in the pathogenesis of PSI. There might exist other neurotransmitters involved in the pathophysiological process of PSI, which should be further explored.

Circulating microRNAs as diagnostic biomarkers for ischemic stroke: evidence from comprehensive analysis and real-world validation.

Ischemic stroke (IS) is the majority of strokes which remain the second leading cause of deaths in the last two decades. Circulating microRNAs (miRNAs) have been suggested as potential diagnostic and therapeutic tools for IS by previous studies analyzing their differential expression. However, inconclusive and controversial conclusions of these results have to be addressed. In this study, comprehensive analysis and real-world validation were performed to assess the associations between circulating miRNAs and IS. 29 studies with 112 miRNAs were extracted after manual selection and filtering, 12 differentially expressed miRNAs were obtained from our results of meta-analysis. These miRNAs were evaluated in 20 IS patients, compared to 20 healthy subjects. 4 miRNAs (hsa-let-7e-5p, hsa-miR-124-3p, hsa-miR-17-5p, hsa-miR-185-5p) exhibited the significant expression level in IS patient plasma samples. Pathway and biological process enrichment analysis for the target genes of the 4 validated miRNAs identified cellular senescence and neuroinflammation as key post-IS response pathways. The results of our analyses closely correlated with the pathogenesis and implicated pathways observed in IS subjects suggested by the literature, which may provide aid in the development of circulating diagnostic or therapeutic targets for IS patients.

Endothelial CCRL2 induced by disturbed flow promotes atherosclerosis via chemerin-dependent ß2 integrin activation in monocytes.

AIMS: Chemoattractants and their cognate receptors are essential for leucocyte recruitment during atherogenesis, and atherosclerotic plaques preferentially occur at predilection sites of the arterial wall with disturbed flow (d-flow). In profiling the endothelial expression of atypical chemoattractant receptors (ACKRs), we found that Ackr5 (CCRL2) was up-regulated in an endothelial subpopulation by atherosclerotic stimulation. We therefore investigated the role of CCRL2 and its ligand chemerin in atherosclerosis and the underlying mechanism. METHODS AND RESULTS: By analysing scRNA-seq data of the left carotid artery under d-flow and scRNA-seq datasets GSE131776 of ApoE-/- mice from the Gene Expression Omnibus database, we found that CCRL2 was up-regulated in one subpopulation of endothelial cells in response to d-flow stimulation and atherosclerosis. Using CCRL2-/-ApoE-/- mice, we showed that CCRL2 deficiency protected against plaque formation primarily in the d-flow areas of the aortic arch in ApoE-/- mice fed high-fat diet. Disturbed flow induced the expression of vascular endothelial CCRL2, recruiting chemerin, which caused leucocyte adhesion to the endothelium. Surprisingly, instead of binding to monocytic CMKLR1, chemerin was found to activate ß2 integrin, enhancing ERK1/2 phosphorylation and monocyte adhesion. Moreover, chemerin was found to have protein disulfide isomerase-like enzymatic activity, which was responsible for the interaction of chemerin with ß2 integrin, as identified by a Di-E-GSSG assay and a proximity ligation assay. For clinical relevance, relatively high serum levels of chemerin were found in patients with acute atherothrombotic stroke compared to healthy individuals. CONCLUSIONS: Our findings indicate that d-flow-induced CCRL2 promotes atherosclerotic plaque formation via a novel CCRL2-chemerin-ß2 integrin axis, providing potential targets for the prevention or therapeutic intervention of atherosclerosis.

BAG3 Overexpression Attenuates Ischemic Stroke Injury by Activating Autophagy and Inhibiting Apoptosis.

BACKGROUND: The ubiquitin-proteasome system (UPS) and autophagy are 2 major protein degradation pathways in eukaryotic cells. We previously identified a switch from UPS to autophagy with changes in BAG3 (B-cell lymphoma 2-associated-athanogene 3) expression after cerebral ischemia in mice. BAG3 is an antiapoptotic-cochaperone that is directly involved in cellular protein quality control as a mediator for selective macroautophagy. Here, we aimed to investigate the role of BAG3 in ischemic stroke. METHODS: Middle cerebral artery occlusion/reperfusion (MCAO/R) and oxygen-glucose deprivation/reoxygenation were used to mimic cerebral ischemia in vivo and in vitro. The UPS inhibitor MG132 and autophagy inhibitor 3-MA (3-methyladenine) were administered to mice to identify how BAG3 was involved after MCAO/R. Adeno-associated virus and lentiviral vector were used to regulate BAG3 expression in vivo and in vitro, respectively. Behavioral tests, 2,3,5-triphenyltetrazolium chloride staining, and Hematoxylin & Eosin staining were performed to evaluate cerebral injury following MCAO/R, and a Cell Counting kit-8 assay was conducted to assess oxygen-glucose deprivation/reoxygenation-induced injury in cells. Brain tissues and cell lysates were collected and analyzed for UPS activation, autophagy, and apoptosis. RESULTS: The UPS inhibitor alleviated MCAO injury in mice and increased autophagy and BAG3 expression, whereas the autophagy inhibitor exacerbated MCAO/R-induced injury. In addition, BAG3 overexpression significantly improved neurological outcomes, reduced infarct volume in vivo, and enhanced cell survival by activating autophagy and suppressing apoptosis in vitro. CONCLUSIONS: Our findings indicate that BAG3 overexpression activates autophagy and inhibits apoptosis to prevent cerebral ischemia/reperfusion and hypoxia/reoxygenation injury, suggesting a potential therapeutic benefit of BAG3 expression in cerebral ischemia.

Association of beta-2-microglobulin, cystatin C and lipocalin-2 with stroke risk in the general Chinese population.

INTRODUCTION: Beta-2-microglobulin (B2M), cystatin C and lipocalin-2 (LCN-2) are established renal biomarkers, yet their roles in stroke have not been fully evaluated. We aimed to investigate the relationship of B2M, cystatin C, and LCN-2 with stroke risk in a general Chinese population. METHODS: We used ordinal regression to study the relationship between serum B2M, cystatin C, and LCN-2 with stroke risk in 1060 participants (mean age 45.4 ± 10.8 years, 46% male) from the Shenzhen-Hong Kong United Network on Cardiovascular Disease (SHUN-CVD) study. Stroke risk was classified into low-risk, middle-risk and high-risk groups according to the China National Stroke Screening Survey criteria. Serum biomarker levels were measured using immunoturbidimetric assays. Participants with valid data on serum biomarker levels and stroke risk were included in the analysis. RESULTS: The number of participants in the low-risk, middle-risk and high-risk stroke risk groups were 663, 143 and 254 respectively. Elevated serum B2M, cystatin C, and LCN-2 levels were associated with being male, overweight/obesity, hypertension, alcohol consumption and smoking. Serum B2M, cystatin C and LCN-2 levels were significantly associated with stroke risk in the overall population (B2M: ß = 0.595, p < .001; cystatin C: ß = 3.718, p < .001; LCN-2: ß = 0.564, p < .001) after adjustment for age. CONCLUSION: Elevated serum B2M, cystatin C and LCN-2 levels are associated with stroke risk. They may be novel biomarkers for clinicians to assess stroke risk.Key messagesSerum beta-2-microglobulin, cystatin C and lipocalin-2 levels are significantly associated with stroke risk.Beta-2-microglobulin, cystatin C and lipocalin-2 may serve as useful biomarkers for stroke risk stratification in the general population.

In Situ Sprayed Difunctional Gel Avoiding Microenvironments Limitations to Treat Pressure Ulcers.

How to avoid the microenvironment limitations in the therapeutic process of pressure ulcers is still challenging. The development of a functional gel can kill bacteria and scavenge reactive oxygen species (ROS), which is urgently required in the therapeutic process of pressure ulcers. Herein, an in situ sprayed gel is developed with silver nanoparticles (AgNPs) and polydopamine (PDA) NPs (APG) to obviate microenvironment restrictions in treating pressure ulcers. The gel is constructed by spraying sodium alginate solution and CaCl2 solution. AgNPs serve as an antibacterial agent in the formed gel, which can effectively cause bacterial inactivation and show more than 5 log (>99.999%) bacterial killing efficiency against methicillin-resistant S. aureus (MRSA), Staphylococcus aureus (S. aureus), and Escherichia coli (E. coli) in vitro. Meanwhile, PDA NPs serve as the antioxidative agent in the formed gel, which can facilitate the elimination of ROS to address the high ROS problem in wound microenvironment. Based on these features, it is demonstrated through cell and animal experiments that the AgNPs and PDA NPs incorporated gel can realize the effective treatment of MRSA-infected and hydrogen peroxide (H2 O2 )-sensitized pressure ulcers. It is believed that the designed system by a simple spray-coating approach can provide a new therapeutic strategy in biomedical areas.

Estimated Burden of Stroke in China in 2020.

Importance: Stroke is the leading cause of death in China. However, recent data about the up-to-date stroke burden in China are limited. Objective: To investigate the urban-rural disparity of stroke burden in the Chinese adult population, including prevalence, incidence, and mortality rate, and disparities between urban and rural populations. Design, Setting, and Participants: This cross-sectional study was based on a nationally representative survey that included 676 394 participants aged 40 years and older. It was conducted from July 2020 to December 2020 in 31 provinces in mainland China. Main Outcomes and Measures: Primary outcome was self-reported stroke verified by trained neurologists during a face-to-face interviews using a standardized protocol. Stroke incidence were assessed by defining first-ever strokes that occurred during 1 year preceding the survey. Strokes causing death that occurred during the 1 year preceding the survey were considered as death cases. Results: The study included 676 394 Chinese adults (395 122 [58.4%] females; mean [SD] age, 59.7 [11.0] years). In 2020, the weighted prevalence, incidence, and mortality rates of stroke in China were 2.6% (95% CI, 2.6%-2.6%), 505.2 (95% CI, 488.5-522.0) per 100 000 person-years, and 343.4 (95% CI, 329.6-357.2) per 100 000 person-years, respectively. It was estimated that among the Chinese population aged 40 years and older in 2020, there were 3.4 (95% CI, 3.3-3.6) million incident cases of stroke, 17.8 (95% CI, 17.5-18.0) million prevalent cases of stroke, and 2.3 (95% CI, 2.2-2.4) million deaths from stroke. Ischemic stroke constituted 15.5 (95% CI, 15.2-15.6) million (86.8%) of all incident strokes in 2020, while intracerebral hemorrhage constituted 2.1 (95% CI, 2.1-2.1) million (11.9%) and subarachnoid hemorrhage constituted 0.2 (95% CI, 0.2-0.2) million (1.3%). The prevalence of stroke was higher in urban than in rural areas (2.7% [95% CI, 2.6%-2.7%] vs 2.5% [95% CI, 2.5%-2.6%]; P = .02), but the incidence rate (485.5 [95% CI, 462.8-508.3] vs 520.8 [95% CI, 496.3-545.2] per 100 000 person-years; P < .001) and mortality rate (309.9 [95% CI, 291.7-328.1] vs 369.7 [95% CI, 349.1-390.3] per 100 000 person-years; P < .001) were lower in urban areas than in rural areas. In 2020, the leading risk factor for stroke was hypertension (OR, 3.20 [95% CI, 3.09-3.32]). Conclusions and Relevance: In a large, nationally representative sample of adults aged 40 years or older, the estimated prevalence, incidence, and mortality rate of stroke in China in 2020 were 2.6%, 505.2 per 100 000 person-years, and 343.4 per 100 000 person-years, respectively, indicating the need for an improved stroke prevention strategy in the general Chinese population.