Enhanced VEGF secretion and blood-brain barrier disruption: Radiation-mediated inhibition of astrocyte autophagy via PI3K-AKT pathway activation.

Radiation-induced damage to the blood-brain barrier (BBB) is the recognized pathological basis of radiation-induced brain injury (RBI), a side effect of head and neck cancer treatments. There is currently a lack of therapeutic approaches for RBI due to the ambiguity of its underlying mechanisms. Therefore, it is essential to identify these mechanisms in order to prevent RBI or provide early interventions. One crucial factor contributing to BBB disruption is the radiation-induced activation of astrocytes and oversecretion of vascular endothelial growth factor (VEGF). Mechanistically, the PI3K-AKT pathway can inhibit cellular autophagy, leading to pathological cell aggregation. Moreover, it acts as an upstream pathway of VEGF. In this study, we observed the upregulation of the PI3K-AKT pathway in irradiated cultured astrocytes through bioinformatics analysis, we then validated these findings in animal brains and in vitro astrocytes following radiation exposure. Additionally, we also found the inhibition of autophagy and the oversecretion of VEGF in irradiated astrocytes. By inhibiting the PI3K-AKT pathway or promoting cellular autophagy, we observed a significant amelioration of the inhibitory effect on autophagy, leading to reductions in VEGF oversecretion and BBB disruption. In conclusion, our study suggests that radiation can inhibit autophagy and promote VEGF oversecretion by upregulating the PI3K-AKT pathway in astrocytes. Blocking the PI3K pathway can alleviate both of these effects, thereby mitigating damage to the BBB in patients undergoing radiation treatment.

Neutralization of interleukin-9 ameliorates experimental stroke by repairing the blood-brain barrier via down-regulation of astrocyte-derived vascular endothelial growth factor-A.

Astrocytes mediate the destruction of the blood-brain barrier (BBB) during ischemic stroke (IS). IL-9 is a pleiotropic cytokine that we previously found to be highly expressed in peripheral blood mononuclear cells from patients with IS, and the presence of IL-9 receptors on astrocytes has been reported in the literature. Here, we detected the effect of IL-9 on astrocytes using an anti-IL-9-neutralizing antibody to treat rats with experimental stroke. Supernatants from astrocytes treated with or without oxygen-glucose deprivation and/or IL-9 were incubated with bEnd.3 cell monolayers after blocking the IL-9 receptor on the endothelium. Immunofluorescence staining and Western blot analyses were conducted to observe the change in tight junction proteins (TJPs) in bEnd.3 cells as well as the level of VEGF-A and possible signal pathways in astrocytes. We also applied middle cerebral artery occlusion (MCAO) models to determine the effect of anti-IL-9-neutralizing antibodies on IS. As a result, astrocyte-conditioned medium treated with IL-9 aggravated the disruption of the BBB accomplished by the degradation of TJPs in endothelial cells. In addition, IL-9 increased the level of VEGF-A in astrocytes, and blocking the effect of VEGF-A reversed the breakdown of the BBB. In the MCAO model, anti-IL-9-neutralizing antibody reduced the infarct volume and BBB destruction. Mechanistically, the anti-IL-9-neutralizing antibody repaired the damaged TJPs (zonula occludens 1, occludin, and claudin-5) and induced a decrease in VEGF-A expression in ischemic lateral brain tissue. In contrast, a local injection of recombinant murine IL-9 to the brain resulted in a marked up-regulation of VEGF-A in the striatum. In conclusion, anti-IL-9-neutralizing antibody can reduce the severity of IS partially by alleviating the destruction of the BBB via down-regulation of astrocyte-derived VEGF-A. This finding suggests that targeting IL-9 or VEGF-A could provide a new direction for the treatment of IS.-Tan, S., Shan, Y., Lin, Y., Liao, S., Zhang, B., Zeng, Q., Wang, Y., Deng, Z., Chen, C., Hu, X., Peng, L., Qiu, W., Lu, Z. Neutralization of IL-9 ameliorates experimental stroke by repairing the blood-brain barrier via down-regulation of astrocyte-derived vascular endothelial growth factor-A.

The glucagon-like peptide-1 receptor agonist reduces inflammation and blood-brain barrier breakdown in an astrocyte-dependent manner in experimental stroke.

BACKGROUND: Preserving the integrity of the blood-brain barrier (BBB) is beneficial to avoid further brain damage after acute ischemic stroke (AIS). Astrocytes, an important component of the BBB, promote BBB breakdown in subjects with AIS by secreting inflammatory factors. The glucagon-like peptide-1 receptor (GLP-1R) agonist exendin-4 (Ex-4) protects the BBB and reduces brain inflammation from cerebral ischemia, and GLP-1R is expressed on astrocytes. However, the effect of Ex-4 on astrocytes in subjects with AIS remains unclear. METHODS: In the present study, we investigated the effect of Ex-4 on astrocytes cultured under oxygen-glucose deprivation (OGD) plus reoxygenation conditions and determined whether the effect influences bEnd.3 cells. We used various methods, including permeability assays, western blotting, immunofluorescence staining, and gelatin zymography, in vitro and in vivo. RESULTS: Ex-4 reduced OGD-induced astrocyte-derived vascular endothelial growth factor (VEGF-A), matrix metalloproteinase-9 (MMP-9), chemokine monocyte chemoattractant protein-1 (MCP-1), and chemokine C-X-C motif ligand 1 (CXCL-1). The reduction in astrocyte-derived VEGF-A and MMP-9 was related to the increased expression of tight junction proteins (TJPs) in bEnd.3 cells. Ex-4 improved neurologic deficit scores, reduced the infarct area, and ameliorated BBB breakdown as well as decreased astrocyte-derived VEGF-A, MMP-9, CXCL-1, and MCP-1 levels in ischemic brain tissues from rats subjected to middle cerebral artery occlusion. Ex-4 reduced the activation of the JAK2/STAT3 signaling pathway in astrocytes following OGD. CONCLUSION: Based on these findings, ischemia-induced inflammation and BBB breakdown can be improved by Ex-4 through an astrocyte-dependent manner.

Exacerbation of oxygen-glucose deprivation-induced blood-brain barrier disruption: potential pathogenic role of interleukin-9 in ischemic stroke.

Interleukin (IL)-9 exerts a variety of functions in autoimmune diseases. However, its role in ischemic brain injury remains unknown. The present study explored the biological effects of IL-9 in ischemic stroke (IS). We recruited 42 patients newly diagnosed with IS and 22 age- and sex-matched healthy controls. The expression levels of IL-9 and percentages of IL-9-producing T cells, including CD3+CD4+IL-9+ and CD3+CD8+IL-9+ cells, were determined in peripheral blood mononuclear cells (PBMCs) obtained from patients and control individuals. We also investigated the effects of IL-9 on the blood-brain barrier (BBB) following oxygen-glucose deprivation (OGD) and the potential downstream signaling pathways. We found that patients with IS had higher IL-9 expression levels and increased percentages of IL-9-producing T cells in their PBMCs. The percentages of CD3+CD4+IL-9+ and CD3+CD8+IL-9+ T cells were positively correlated with the severity of illness. In in vitro experiments using bEnd.3 cells, exogenously administered IL-9 exacerbated the loss of tight junction proteins (TJPs) in cells subjected to OGD plus reoxygenation (RO). This effect was mediated via activation of IL-9 receptors, which increased the level of endothelial nitric oxide synthase (eNOS), as well as through up-regulated phosphorylation of signal transducer and activator of transcription 1 and 3 and down-regulated phosphorylated protein kinase B/phosphorylated phosphatidylinositol 3-kinase signaling. These results indicate that IL-9 has a destructive effect on the BBB following OGD, at least in part by inducing eNOS production, and raise the possibility of targetting IL-9 for therapeutic intervention in IS.

Distinct Expression of Various Angiogenesis Factors in Mice Brain After Whole-Brain Irradiation by X-ray.

Radiation-induced brain injury (RBI) is the most serious complication after radiotherapy. However, the etiology of RBI remains elusive. In order to evaluate the effect of X-rays on normal brain tissue, adult male BALB/C mice were subjected to whole-brain exposure with a single dose of 10 Gy or sham radiation. The structure and number of mice brain vessels were investigated 1, 7, 30, 90 and 180 days after irradiation by H&E staining and immune-fluorescence staining. Compared with sham control mice, in addition to morphological changes, a significant reduction of microvascular density was detected in irradiated mice brains. Whole-brain irradiation also caused damage in tight junction (TJ). Increased expression of glial fibrillary acidic protein (GFAP) and vascular endothelial growth factor (VEGF) was observed in irradiated mouse brains showed by Western Blot. Immune-fluorescence staining results also verified the co-labeling of GFAP and VEGF after whole-brain irradiation. Furthermore, the protein expression levels of other angiogenesis factors, angiopoietin-1 (Ang-1), endothelial-specific receptor tyrosine kinase (Tie-2), and angiopoietin-2 (Ang-2) in brain were determined by Western Blot. Increased expression of Ang-2 was shown in irradiated mouse brains. In contrast, whole-brain irradiation significantly decreased Ang-1 and Tie-2 expression. Our data indicated that X-rays induced time-dependent microvascular injury and activation of astrocytes after whole-brain irradiation in mouse brain. Distinct regulation of VEGF/Ang2 and Ang-1/Tie-2 are closely associated with RBI, suggesting that angiogenesis interventions might be beneficial for patients with RBI.

[Expression changes of Ang-1, Ang-2, Tie-2 and VEGF in co-culturing of endothelial cells and astrocytes after irradiation by X-ray and their significances].

OBJECTIVE: To explore the possible relationship between angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2), Tie-2 and vascular endothelial growth factor (VEGF) and radiation brain injury (RBI) and detect the expressions of VEGF, Ang-1, Ang-2 and Tie-2 in co-cultured endothelial cells and astrocytes after an irradiation of X-ray. METHODS: Murine brain microvascular endothelial cells bEnd.3 and astrocytes were co-cultured in a Transwell culture plate and then exposed to X-ray at various doses (5, 10, 20 and 30 Gy) and cultured for 24 hours. The group without radiation acted as a control. Western blot was used to detect the expressions of VEGF, Ang-1, Ang-2 and Tie-2. RESULTS: As compared with the control group, the expression of VEGF increased in 5, 10, 20 and 30 Gy dose groups [(1.71 ± 0.11), (2.03 ± 0.05), (2.20 ± 0.06), (2.19 ± 0.08) vs (1.26 ± 0.10), P < 0.05]; the expression of Ang-1 decreased in 5, 10, 20 and 30 Gy dose groups [(2.27 ± 0.07), (2.28 ± 0.06), (2.01 ± 0.05), (1.54 ± 0.08) vs (2.46 ± 0.04), P < 0.05]; the expression of Tie-2 decreased in 5, 10, 20 and 30 Gy dose groups [(2.40 ± 0.10), (2.47 ± 0.06), (1.05 ± 0.09), (1.00 ± 0.08)vs(4.80 ± 0.07), P < 0.05]; the expression of Ang-2 increased in 5 Gy and 10 Gy dose groups [(2.10 ± 0.07), (2.43 ± 0.08)vs (1.69 ± 0.05), P < 0.05] while decreased in 20 Gy and 30 Gy dose groups [(1.12 ± 0.10), (1.21 ± 0.04)vs(1.69 ± 0.05), P < 0.05]. CONCLUSION: X-ray could differentially affect the expressions of VEGF, Ang-1, Ang-2 and Tie-2 in co-cultured endothelial cells and astrocytes. And the differential expressions of VEGF, Ang-1, Ang-2 and Tie-2 may be related with microvascular injury in RBI.

FGIN-1-27 Mitigates Radiation-induced Mitochondrial Hyperfunction and Cellular Hyperactivation in Cultured Astrocytes.

Radiation-induced brain injury (RBI) poses a significant challenge in the context of radiotherapy for intracranial tumors, necessitating a comprehensive understanding of the cellular and molecular mechanisms involved. While prior investigations have underscored the role of astrocyte activation and excessive vascular endothelial growth factor production in microvascular damage associated with RBI, there remains a scarcity of studies examining the impact of radiation on astrocytes, particularly regarding organelles such as mitochondria. Thus, our study aimed to elucidate alterations in astrocyte and mitochondrial functionality following radiation exposure, with a specific focus on evaluating the potential ameliorative effects of translocator protein 18 kDa(TSPO) ligands. In this study, cultured astrocytes were subjected to X-ray irradiation, and their cellular states and mitochondrial functions were examined and compared to control cells. Our findings revealed that radiation-induced astrocytic hyperactivation, transforming them into the neurotoxic A1-type, concomitant with reduced cell proliferation. Additionally, radiation triggered mitochondrial hyperfunction, heightened the mitochondrial membrane potential, and increased oxidative metabolite production. However, following treatment with FGIN-1-27, a TSPO ligand, we observed a restoration of mitochondrial function and a reduction in oxidative metabolite production. Moreover, this intervention mitigated astrocyte hyperactivity, decreased the number of A1-type astrocytes, and restored cell proliferative capacity. In conclusion, our study has unveiled additional manifestations of radiation-induced astrocyte dysfunction and validated that TSPO ligands may serve as a promising therapeutic strategy to mitigate this dysfunction. It has potential clinical implications for the treatment of RBI.

Directed natural evolution generates a next-generation oncolytic virus with a high potency and safety profile.

Oncolytic viruses (OVs) represent a type of encouraging multi-mechanistic drug for the treatment of cancer. However, attenuation of virulence, which is generally required for the development of OVs based on pathogenic viral backbones, is frequently accompanied by a compromised killing effect on tumor cells. By exploiting the property of viruses to evolve and adapt in cancer cells, we perform directed natural evolution on refractory colorectal cancer cell HCT-116 and generate a next-generation oncolytic virus M1 (NGOVM) with an increase in the oncolytic effect of up to 9690-fold. The NGOVM has a broader antitumor spectrum and a more robust oncolytic effect in a range of solid tumors. Mechanistically, two critical mutations are identified in the E2 and nsP3 genes, which accelerate the entry of M1 virus by increasing its binding to the Mxra8 receptor and antagonize antiviral responses by inhibiting the activation of PKR and STAT1 in tumor cells, respectively. Importantly, the NGOVM is well tolerated in both rodents and nonhuman primates. This study implies that directed natural evolution is a generalizable approach for developing next-generation OVs with an expanded scope of application and high safety.

Low serum 25-hydroxyvitamin D3 levels and late delayed radiation-induced brain injury in patients with nasopharyngeal carcinoma: A case-control study.

BACKGROUND AND PURPOSE: Inflammatory reaction plays a critical role in the pathogenesis of late delayed radiation-induced brain injury (RBI). Low vitamin D levels are closely associated with various immuno-inflammatory diseases, but the relationship with late delayed RBI remains unknown. Here, we aimed to determine the association of serum vitamin D levels with clinical parameters in late delayed RBI patients with nasopharyngeal carcinoma. METHODS: 25-Hydroxyvitamin D3 levels and clinical and cerebrospinal fluid parameters were evaluated in 21 patients with RBI and compared with 90 age-, sex-, and season-matched healthy controls. RESULTS: 25-(OH)D3 levels were lower in patients with RBI compared to controls (40.39 ± 22.11 vs. 64.54 ± 19.89 nmol/L, p < .001), especially for aged ≥60 years (vs. <60 years, p = .038), females (vs. males, p = .012), short latency (<5 years) (vs. ≥5 years, p = .015), and severe impairment (LENT/SOMA score ≥3) (vs. LENT/SOMA score <3, p = .010). Serum 25-(OH)D3 levels were associated with age (r = -.464, p = .015), Latency of RBI (r = .416, p = .031) and LENT/SOMA Scale (r = -.488, p = .010). CONCLUSIONS: Our data showed that serum 25-(OH)D3 levels were reduced in late delayed RBI patients with nasopharyngeal carcinoma.

Endothelial progenitor cell transplantation restores vascular injury in mice after whole-brain irradiation.

Vascular damage plays an important role in the pathogenesis of radiation-induced brain injury (RBI). Endothelial progenitor cells (EPCs) are responsible for maintaining and repairing endothelial function, and have become a promising method for the treatment of cerebrovascular diseases. However, whether EPC transplantation plays a protective role in RBI has not been fully elucidated. Therefore, the present study investigated the effects of bone marrow-derived EPC transplantation in a whole-brain irradiation (WBI) mouse model. Mice were divided into the three groups: control group, irradiation group and EPCs group. Phosphate buffered saline or EPCs were intravenously injected into mice one week after irradiation, and brains were analyzed eight weeks after injection. Flow cytometry demonstrated that irradiation led to a significant reduction in the peripheral blood EPC count; however, EPC transplantation led to a significant increase in the circulating EPCs. Intravital two-photon imaging and western blotting demonstrated that EPC transplantation reversed the effects of irradiation by decreasing blood-brain barrier permeability and increasing the expression of tight junction proteins in the brain. Additionally, immunofluorescence staining revealed that the brain microvascular density was higher in the EPCs group than the irradiation group. Therefore, EPC transplantation may restore damage caused by WBI to the blood-brain barrier, tight junctions, and cerebral capillary density. These results highlight the potential beneficial effects of EPC transplantation on vascular damage induced by RBI.

Astrocyte-derived VEGF increases cerebral microvascular permeability under high salt conditions.

Excess salt (NaCl) intake is closely related to a variety of central nervous system (CNS) diseases characterized by increased cerebral microvascular permeability. However, the link between a high salt diet (HSD) and the breakdown of tight junctions (TJs) remains unclear. In the present study, we found that high salt does not directly influence the barrier between endothelial cells, but it suppresses expression of TJ proteins when endothelial cells are co-cultured with astrocytes. This effect is independent of blood pressure, but depends on the astrocyte activation via the NFκB/MMP-9 signaling pathway, resulting in a marked increase in VEGF expression. VEGF, in turn, induces disruption of TJs by inducing phosphorylation and activation of ERK and eNOS. Correspondingly, the HSD-induced disruption of TJ proteins is attenuated by blocking VEGF using the specific monoclonal antibody Bevacizumab. These results reveal a new axis linking a HSD to increased cerebral microvascular permeability through a VEGF-initiated inflammatory response, which may be a potential target for preventing the deleterious effects of HSD on the CNS.

Astrocytes-derived VEGF exacerbates the microvascular damage of late delayed RBI.

Overexpression of vascular endothelial growth factor (VEGF) is considered the most critical factor in radiation-induced brain injury (RBI). To investigate the role of VEGF and the mechanism underlying microvascular damage in RBI, wild type mice, and transgenic mice overexpressing VEGF derived from astrocytes, were separately and randomly exposed to whole-brain or sham irradiation. Pathophysiologic changes in the brain tissue were detected 90 days after irradiation. Compared with wild type mice, the secretion of VEGF and angiopoietin-2 (Ang-2) was up-regulated in transgenic mice, whether irradiated or not, while elevated expression of VEGF, Ang-2, and glial fibrillary acidic protein (GFAP) was detected after whole-brain irradiation using western blotting. Impairment of the blood-brain barrier (BBB) was demonstrated by the leakage of dyes observed using two-photon imaging and decreased expression of zonula occludens-1 (ZO-1) and Occludin. Hematoxylin-eosin (HE) staining revealed obvious structural damage in the irradiated brains. Furthermore, damage to the BBB and histopathology in the transgenic mice were worse than those of wild type mice in the irradiated groups. There was a positive correlation among VEGF and Ang-2 expression and RBI severity. These data reveal that VEGF and Ang-2 expression is closely associated with the microvascular injury in RBI. Further, overexpression of VEGF can cause up-regulation of Ang-2 and exacerbation of RBI. Therefore, Ang-2 might be the cytokine that acts as a mediator between VEGF and microvascular injury, and is likely a new intervention target for RBI.

Overexpression of PRR11 promotes tumorigenic capability and is associated with progression in esophageal squamous cell carcinoma.

INTRODUCTION: Esophageal squamous cell carcinoma (ESCC) is one of the most common malignancies of gastrointestinal tract in the world, and the long-term prognosis for ESCC patients still remains dismal due to the lack of effective early diagnosis biomarkers. MATERIALS AND METHODS: Western blot and immunochemistry were used to determine the expression of PRR11 in 201 clinicopathologically characterized ESCC specimens. The effects of PRR11 on stem cell-like traits and tumorigenicity were examined by tumor sphere formation assay and SP assays in vitro and by a tumorigenesis model in vivo. The mechanism by which PRR11 mediated Wnt/ß-catenin signaling was explored using luciferase reporter, immuno-chemistry, and real time-PCR (RT-PCR) assays. RESULTS: We found that PRR11 was markedly upregulated, at the level of both transcription and translation, in ESCC cell lines as compared with normal esophageal epithelial cells (NECCs). Immunohistochemical analysis showed that 69.2% paraffin-embedded archival ESCC specimens exhibited high levels of PRR11 expression, and multivariate analysis revealed that PRR11 upregulation might be an independent prognostic indicator for the survival of patients with ESCC. Furthermore, overexpression of PRR11 dramatically enhanced, whereas inhibition of PRR11 reduced the capability of cancer stem cell (CSC)-like phenotypes and tumorigenicity of ESCC cells both in vitro and in vivo. Mechanically, we demonstrated PRR11-enhanced tumorigenicity of ESCC cells via activating Wnt/ß-catenin signaling, and PRR11 expression is found to be significantly correlated with ß-catenin nuclear location in ESCC. CONCLUSION: Our findings suggest that the PRR11 might represent a novel and valuable prognostic marker for ESCC progression and play a role during the development and progression of this malignancy.

TRIM31 promotes glioma proliferation and invasion through activating NF-κB pathway.

BACKGROUND: Glioma is the most lethal primary brain tumor, the survival rate still isn't improved in the past decades. It's essential to study the regulatory mechanism of glioma progression, hoping to find new therapy targets or methods. The family of tripartite motif (TRIM) containing proteins are E3 ubiquitination ligases, which play critical role in various tumor progression. METHODS: Cell proliferation and invasion were analyzed by colony formation assay, soft agar growth assay, BrdU incorporation assay and transwell invasion assay. Luciferase reporter analysis was used to analyze NF-κB pathway activity. RESULTS: We found TRIM31 was upregulated in glioma cells and tissues, its overexpression significantly promoted glioma cell proliferation and invasion, while its knockdown significantly inhibited glioma cell proliferation and invasion. Mechanism analysis found TRIM31 promoted NF-κB pathway activity and increased its targets expression. NF-κB inhibition reversed the phenotype caused by TRIM31, confirming TRIM31 promoted glioma progression through activating NF-κB pathway. Using clinical specimens found TRIM31 expression was positively correlative with NF-κB activity. CONCLUSION: This study found TRIM31 promoted glioma proliferation and invasion through activating NF-κB activity.

Different Mechanisms of Two Subtypes of Perforating Artery Infarct in the Middle Cerebral Artery Territory: A High-Resolution Magnetic Resonance Imaging Study.

Purpose: Perforating Artery Infarcts (PAIs) can be divided into two subtypes based on their etiologies: branch Atheromatous Disease (BAD) and Lacunar Infarct (LI). Recent studies have shown that while both subtypes can be caused by large artery lesions, the different mechanisms that underlie their development are not clear. This study was designed to use High-Resolution Magnetic Resonance Imaging (HRMRI) to explore the differences that contribute to the occurrence of these two subtypes in large artery lesions in the anterior circulation. Methods: Fifty patients with an acute PAI in the anterior circulation were enrolled (32 BAD and 18 LI patients). The ipsilateral middle cerebral artery (MCA) was scanned with HRMRI to analyze the atherosclerosis plaques. Artery remodeling and plaque characteristics of MCA lesions were compared between the two subtypes. Results: The rate of MCA lesions was significantly higher in BAD and substantially lower in LI (P = 0.033). LAs for the lumen areas in Bad, they were smaller than LI (P < 0.001), Additionally, the plaque area (P = 0.001) and plaque burden (P < 0.001) were superior in the BAD group. Most BAD patients displayed non-positive remodeling, while the great majority of LI patients showed positive remodeling (P < 0.001). Conclusion: In the anterior circulation, a considerable amount of BAD and LI share similarities with atherosclerotic plaques in large arteries. BAD patients mainly showed relatively large and stable atherosclerotic plaques in large arteries, while LI patients mainly exhibited relatively small and unstable atherosclerotic plaques. Clinical Trial Registration: This clinical trial is a retrospective study and therefore does not require registration.

Correlation of gene polymorphisms of CD36 and ApoE with susceptibility of Alzheimer disease: A case-control study.

This research was aimed to explore correlation of gene polymorphisms of CD36 and ApoE with susceptibility of Alzheimer disease (AD).This study was a case-control study. Two hundred eleven AD hospitalized patients were selected as the AD group and 241 subjects were selected as the control group. PCR-RFLP was used to detect three loci (rs7755, rs3211956, and rs10499859) of CD36 gene and ApoE genotype. Chi-square test and univariate nonconditional logistic regression analysis were used to calculate the odds ratio (OR) and 95% confidence interval (95% CI). The haplotypes were constructed using SHEsis online software and the correlation between haplotypes and AD was analyzed. Meanwhile, differences of 3 alleles of ApoE and 6 genotypes (E2/E2, E2/E3, E2/E4, E3/E3, E3/E4, E4/E4) were compared between AD and control groups.The frequencies of rs7755 genotype (χ = 10.780, P = .005) and allele (χ = 10.549, P = .001) were statistically different between 2 groups. The genotype frequency of rs3211956 was statistically different between AD and control groups (χ = 10.119, P = .006). For the rs7755 locus, GG genotype (OR: 2.013, 95% CI: 1.098-3.699) was an independent risk factor for AD compared with AA genotype. In the dominant model, the risk to develop AD in AG/GG genotype was 1.686 times higher than AA genotype. For the rs3211956 locus, compared with TT genotype, GT genotype (OR: 0.536, 95% CI: 0.340-0.846) was a protective factor for AD after adjusting various physiological and biochemical factors. In the dominant model, the risk of GT/GG genotype to develop AD was reduced by 41.6%. For ApoE gene, the distribution differences of E2/E3 (χ = 9.216, P = .002), E3/E4 (χ = 7.728, P = .005), and E4/E4 had statistical significance between the 2 groups. The frequencies of allele E2 (χ = 9.359, P = .002) and E4 (χ = 13.995, P < .001) were statistically significant between AD and control groups.The rs7755 and rs3211956 loci polymorphisms of CD36 gene and genotype E2/E3, E3/E4, E4/E4 of ApoE gene, and E2 and E4 alleles were statistically related with AD.

Targeted homing of CCR2-overexpressing mesenchymal stromal cells to ischemic brain enhances post-stroke recovery partially through PRDX4-mediated blood-brain barrier preservation.

Rationale: Mesenchymal stromal cells (MSCs) are emerging as a novel therapeutic strategy for the acute ischemic stroke (AIS). However, the poor targeted migration and low engraftment in ischemic lesions restrict their treatment efficacy. The ischemic brain lesions express a specific chemokine profile, while cultured MSCs lack the set of corresponding receptors. Thus, we hypothesize that overexpression of certain chemokine receptor might help in MSCs homing and improve therapeutic efficacy. Methods: Using the middle cerebral artery occlusion (MCAO) model of ischemic stroke, we identified that CCL2 is one of the most highly expressed chemokines in the ipsilateral hemisphere. Then, we genetically transduced the corresponding receptor, CCR2 to the MSCs and quantified the cell retention of MSCCCR2 compared to the MSCdtomato control. Results: MSCCCR2 exhibited significantly enhanced migration to the ischemic lesions and improved the neurological outcomes. Brain edema and blood-brain barrier (BBB) leakage levels were also found to be much lower in the MSCCCR2-treated rats than the MSCdtomato group. Moreover, this BBB protection led to reduced inflammation infiltration and reactive oxygen species (ROS) generation. Similar results were also confirmed using the in vitro BBB model. Furthermore, genome-wide RNA sequencing (RNA-seq) analysis revealed that peroxiredoxin4 (PRDX4) was highly expressed in MSCs, which mainly contributed to their antioxidant impacts on MCAO rats and oxygen-glucose deprivation (OGD)-treated endothelium. Conclusion: Taken together, this study suggests that overexpression of CCR2 on MSCs enhances their targeted migration to the ischemic hemisphere and improves the therapeutic outcomes, which is attributed to the PRDX4-mediated BBB preservation.

High salt-induced activation and expression of inflammatory cytokines in cultured astrocytes.

Salt (sodium chloride, NaCl) accumulation in the brain is associated with various diseases of central nervous system (CNS). Activation of astrocytes is an important manifestation of pathophysiological processes in the CNS. However, the direct impact of high salt (HS) environment on astrocytes is unclear. In the current study, we found that high salt treatment can induce activation of astrocytes both in vivo and in vitro, manifested as morphological alteration coupled with increased expression of glial fibrillary acidic protein (GFAP). Additionally, HS upregulated the expression of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1ß (IL-1ß) and vascular endothelial growth factor (VEGF); however, its effects on transforming growth factor-ß (TGF-ß) expression were not evident. Furthermore, HS treatment induced increased phosphorylation of signal transducer and activator transcription 3 (STAT 3). Inhibition of Janus kinase 2 (JAK 2) by specific pharmacological antagonists, AG490, attenuated the activation of JAK2/STAT3 pathway and induction of GFAP and other pro-inflammatory factors, respectively. The results suggest that the aforementioned multiple inflammatory cytokines and mediators that may be linked to the HS induced pathogenesis of CNS via the JAK2/STAT3 signaling pathways.

Risk Factors and Clinical Manifestations of Juxtacortical Small Lesions: A Neuroimaging Study.

BACKGROUND AND OBJECTIVE: White matter hyperintensities can be easily identified by brain imaging. Juxtacortical small lesion (JCSL) is a special type of white matter lesion, defined as no greater than 5 mm in diameter and adjacent to the cerebral cortex in location. We notice lately that JCSLs alone may be associated to various neurological symptoms. Here, we design the present study to determine the risk factors for JCSLs and their clinical manifestations in patients in our neurology clinic. METHODS: 206 participants suffered from neurological disorders and completed magnetic resonance imaging (MRI) examinations were divided into two groups: patients with JCSLs and patients without lesions on MRI. Meanwhile, 129 age- and sex-matched healthy volunteers were also recruited. Laboratory examinations and the phenotypes and distributions of the symptoms of the three groups were compared. RESULTS: The serum levels of apoB and homocysteine (HCY) were independently related to the appearance of JCSLs and HCY level was also associated with the number of JCSLs. Patients with JCSLs might present with headache, insomnia, and/or anxiety/depression, which were related with the anatomical locations of the lesions. CONCLUSION: These data suggest that JCSLs are symptomatic and might in result fromarteriole atherosclerosis, which should raise our attention.

Wnt5a Promotes Cortical Neuron Survival by Inhibiting Cell-Cycle Activation.

ß-Amyloid protein (Aß) is thought to cause neuronal loss in Alzheimer's disease (AD). Aß treatment promotes the re-activation of a mitotic cycle and induces rapid apoptotic death of neurons. However, the signaling pathways mediating cell-cycle activation during neuron apoptosis have not been determined. We find that Wnt5a acts as a mediator of cortical neuron survival, and Aß42 promotes cortical neuron apoptosis by downregulating the expression of Wnt5a. Cell-cycle activation is mediated by the reduced inhibitory effect of Wnt5a in Aß42 treated cortical neurons. Furthermore, Wnt5a signals through the non-canonical Wnt/Ca2+ pathway to suppress cyclin D1 expression and negatively regulate neuronal cell-cycle activation in a cell-autonomous manner. Together, aberrant downregulation of Wnt5a signaling is a crucial step during Aß42 induced cortical neuron apoptosis and might contribute to AD-related neurodegeneration.