Chinese medicine Tongxinluo capsule protects against blood-brain barrier disruption after ischemic stroke by inhibiting the low-density lipoprotein receptor-related protein 1 pathway in mice.

BACKGROUND: Chinese medicine Tongxinluo capsule (TXL) has been extensively used to treat ischemic stroke in China, and one of its mechanisms is to protect against blood brain barrier (BBB) disruption after stroke. However, the underlying protective mechanisms are not fully illuminated. It is reported that the low-density lipoprotein receptor-related protein 1 (LRP-1) is involved in BBB disruption after brain ischemia. In this study, we explored whether TXL could downregulate LRP-1 expression and subsequently protect against BBB disruption after stroke using permanent middle cerebral artery occlusion (pMCAO) in mice. METHODS: The animal model of ischemic stroke was induced by pMCAO in male adult C57BL/6J mice. The mice were orally administered TXL (3.0 g/kg) at 1, 3 and 21 h after pMCAO. Meanwhile, the LRP-1 antagonist receptor associated protein (RAP) was intracerebroventricularly injected at 1 and 21 h after stroke. We measured the following parameters at 6 and 24 h: LRP-1 protein level, BBB leakage, and the expression of tight junction (TJ) proteins including occludin, claudin-5 and zonula occludens-1 (ZO-1). RESULTS: Our results showed that TXL downregulated LRP-1 level, upregulated these TJ proteins level, and reduced BBB leakage in peri-infarct regions after pMCAO. Further study found that the inhibitor RAP played the same role as did TXL in upregulating these TJ proteins level and reducing BBB leakage after stroke. CONCLUSION: Our study demonstrates that TXL protects against BBB disruption after stroke via inhibiting the LRP-1 pathway.

[Effect of Sijunzi Decoction on regulation of Aß-related proteins across blood-brain barrier].

According to traditional Chinese medicine, "spleen transport" is closely related to the metabolism of substance and energy. Studies have shown that Alzheimer's disease(AD) is a disease related to glucose and lipid metabolism and energy metabolism. The traditional Chinese medicine Jiangpi Recipe can improve the learning ability and memory of AD animal model. Sijunzi Decoction originated from Taiping Huimin Hefang Prescription is the basic prescription for strengthening and nourishing the spleen, with the effects of nourishing Qi and strengthening the spleen. In this experiment, human brain microvascular endothelial cells(HBMEC) and Sijunzi Decoction water extract(0.25, 0.5, 1 mg·L~(-1)) were pre-incubated for 2 h, and then Aß_(25-35) oligomers(final concentration 40 µmol·L~(-1)) was added for co-culture for 22 hours. The effect of Sijunzi Decoction on the activity of Aß_(25-35) oligomer injured cells and the expression of related proteins were investigated. Q-TOF-LC-MS was used first for principal component analysis of Sijunzi Decoction water extract. Then MTT assay was used to investigate the effect of Sijunzi Decoction water extract on the proliferation of HBMEC cells. Real-time fluorescence quantitative PCR(RT-qPCR) was employed to detect the mRNA expression of GLUT1, RAGE, and LRP1. The expression of Aß-related proteins across blood-brain barrier(RAGE, LRP1) was detected by Western blot. The results showed that 40 µmol·L~(-1) Aß_(25-35) oligomers could induce endothelial cell damage, reduce cell survival, increase expression of RAGE mRNA and RAGE protein, and reduce expression of GLUT1 mRNA, LRP1 mRNA, and LRP1 protein. Sijunzi Decoction water extract could reduce the Aß_(25-35) oligomer-induced cytotoxicity of HBMEC, decrease the expression of RAGE mRNA and RAGE protein, and increase the expression of GLUT1 mRNA, LRP1 mRNA and LRP1 protein. The results indicated that Sijunzi Decoction could reduce the injury of HBMEC cells induced by Aß_(25-35) oligomer, and regulate the transport-related proteins GLUT1, RAGE and LRP1, which might be the mechanism of regulating Aß_(25-35) transport across the blood-brain barrier.

Effect of Zhenxin Xingshui Yizhi Fang on Aß25-35 induced expression of related transporters in HBMEC cell model.

ETHNOPHARMACOLOGICAL RELEVANCE: Aß (ß-amyloid) deposition and abnormal transport were suggested to be risk factors for Alzheimer's disease (AD). Zhenxin Xingshui Yizhi Fang (XSF), an ancient prescription in traditional Chinese medicine, was first recorded in Qianjin Yifang for treating palpitation, hypnosia, amnesia. It is reported that XSF could improve mice learning memory ability, reduce the deposition of senile plaques in hippocampus of rat brain. In this study, the neuroprotective effect of XSF against Aß25-35-induced apoptosis in cultured human brain microvascular endothelial cells (HBMEC) and its potential mechanism were investigated. MATERIALS AND METHODS: HBMEC cells were treated with Aß25-35 to established neurotoxic cell model. After that, the cells were treated with 125, 250, 500 µg/mL XSF to observe the protective effect. The viability of HBMEC cells were evaluated by MTT assay, the Aß25-35-induced apoptosis was characterized by Hoechst-33258 and the activity of cysteinyl aspartate specific proteinase-3. The expression level of Aß1-42 in cells induced by Aß25-35 was measured by human Aß1-42 kit. Protein and mRNA expression levels of advanced glycation end products (RAGE), low density lipoprotein receptor-related protein 1 (LRP1), glucose transporter 1 and 3 (GLUT1 and GLUT3) were assayed by capillary electrophoresis immunoassay and quantitative real-time polymerase chain reaction analyses. RESULTS: In Aß25-35 induced neurotoxic cells, the percentage of apoptotic cells, the concentration of Aß1-42 and CASPASE-3 activity, protein and mRNA expression levels of RAGE increased significantly, but that of LRP1, GLUT1 and GLUT3 significantly decreased. XSF could inhibit the apoptotic of cells, reduced the concentration of Aß1-42 and CASPASE-3 expression, downregulate RAGE and upregulate LRP1, GLUT1 and GLUT3 expression. CONCLUSION: The results suggest that XSF can reduce the cytotoxicity of HBMEC induced by Aß25-35, inhibit apoptosis, and regulate the transport of Aß on BBB and energy metabolism disorder in HBMEC.

[Effect of moxibustion on expression of RAGE and LRP-1 and neuronal ultrastructure of frontal cortex and hippocampus in vascular dementia rats].

OBJECTIVE: To explore the effect of moxibustion of acupoints of Governor Vessel on learning-memory ability and expression of the receptor for advanced glycation end products (RAGE), low density lipoprotein (LDL) receptor related protein-1 (LRP-1), ß-amyloid precursor protein (APP) and neuronal ultrastructure of the frontal cortex and hippocampus in vascular dementia (VD) rats, so as to investigate its underlying mechanisms in relieving VD. METHODS: A total of 24 male SD rats were randomized into normal, model, and moxibustion groups (n＝8 rats in each group). The VD model was established by occlusion of the bilateral common carotid arteries for 20 min and reperfusion for 10 min which was repeated for 3 times. Moxibustion was applied to "Baihui" (GV20), "Dazhui"(GV14) and "Fengfu"(GV16)for 30 min, once daily for 4 weeks. The learning-memory ability was evaluated by using Morris water maze tests. At the end of experiments, the frontal lobe of cerebral cortex and hippocampus tissues were collected for detecting the expression of RAGE and LRP-1 proteins with Western blot, and RAGE, LRP-1 and APP mRNAs with quantitative real-time PCR, respectively. The ultrastructure of neurons in the frontal cortex and hippocampal CA1 region was observed with transmission electron microscopy. RESULTS: Following modeling, Morris water maze tests showed that the average escape latency of the model group and moxibustion group was significantly prolonged on the 4th day of modeling (P<0.01). The expression levels of RAGE protein and mRNA and APP mRNA were significantly increased (P<0.01), while those of LRP-1 protein and mRNA in the cortex and hippocampus remarkably decreased in the model group relevant to the normal group (P<0.01). Following moxibustion, modeling-induced increase of expression of RAGE protein and mRNA and APP mRNA, and down-regulation of expression of LRP-1 protein and mRNA were reversed in the moxibustion group relevant to the model group (P<0.01). Results of electron microscopy showed dilation of the mitochondria with disappearance of the cristae, partial vacuolar degeneration or dissolved external membrane, and cytoplasmic edema with basic disappearance of the rough endoplasmic reticulum and glycogen particles in neurons of the frontal cortex and hippocampal CA1 region after modeling, which was relatively milder in the moxibustion group. CONCLUSION: Moxibustion of acupoints of the Governor Vessel may reduce the content of APP in the frontal cortex and hippocampus by regulating the expression of RAGE and LRP-1 proteins and mRNA in VD rats.

5-Caffeoylquinic Acid Ameliorates Cognitive Decline and Reduces Aß Deposition by Modulating Aß Clearance Pathways in APP/PS2 Transgenic Mice.

The accumulation of amyloid ß (Aß) in the brain is a major pathological feature of Alzheimer's disease (AD). In our previous study, we demonstrated that coffee polyphenols (CPP) prevent cognitive dysfunction and Aß deposition in the brain of an APP/PS2 transgenic mouse AD model. The underlying mechanisms, however, remain to be elucidated. Here, we investigated the effects of the chronic administration of 5-caffeoylquinic acid (5-CQA), the most abundant component of CPP, on cognitive dysfunction in APP/PS2 mice to identify the role of CPP in Aß elimination. Relative to the untreated controls, the mice fed a 5-CQA-supplemented diet showed significant improvements in their cognitive function assessed by Y-maze and novel object recognition tests. Histochemical analysis revealed that 5-CQA substantially reduced Aß plaque formation and neuronal loss in the hippocampi. Moreover, 5-CQA upregulated the gene encoding low-density lipoprotein receptor-related protein 1, an Aß efflux receptor, and normalized the perivascular localization of aquaporin 4, which facilitates Aß clearance along the paravascular pathway. These results suggest that 5-CQA reduces Aß deposition in the brain by modulating the Aß clearance pathways and ameliorating cognitive decline and neuronal loss in APP/PS2 mice. Thus, 5-CQA may be effective in preventing cognitive dysfunction in AD.

Omega-3 polyunsaturated fatty acids promote brain-to-blood clearance of ß-Amyloid in a mouse model with Alzheimer's disease.

Amyloid-ß (Aß) plaques is one of the typical pathological hallmark of Alzheimer disease (AD). Accumulating evidence suggests that the imbalance between Aß production and clearance leads to extracellular Aß accumulation in the brain. It is reported that the blood-brain barrier (BBB) transport plays a predominant role in Aß clearance from brain to blood. In the present study, we investigated dynamic alterations of BBB transport function in the early disease stage of AD using APPswe/PS1dE9 C57BL/6J (APP/PS1) transgenic mice. Our results showed that the expression of lipoprotein receptor-related protein 1 (LRP-1), a main efflux transporter of BBB, started to decrease at the age of 4 months old. Interestingly, supplementing with fish oil which is rich in omega-3 polyunsaturated fatty acids (PUFAs) significantly enhanced the expression level of LRP-1 and promoted Aß clearance from the bran to circulation, as revealed by reduced soluble/insoluble Aß levels and senile plaques in the brain parenchyma and a corresponding increase of Aß levels in plasma. Besides, fish oil supplement significantly inhibited the NF-κB activation, reduced the expression of interleukin-1ß and tumor necrosis factor-α, and suppressed the glial activation in APP/PS1 mice. The results of the study provide evidence that BBB transport function could be impaired at a very early disease stage, which might contribute to Aß pathological accumulation in AD, and omega-3 PUFAs intervention could be an effective strategy for the prevention of the progression of AD through promoting Aß clearance from brain-to-blood.

Effect of Sijunzi Decoction on regulation of Aβ-related proteins across blood-brain barrier / 中国中药杂志

According to traditional Chinese medicine, "spleen transport" is closely related to the metabolism of substance and energy. Studies have shown that Alzheimer's disease(AD) is a disease related to glucose and lipid metabolism and energy metabolism. The traditional Chinese medicine Jiangpi Recipe can improve the learning ability and memory of AD animal model. Sijunzi Decoction originated from Taiping Huimin Hefang Prescription is the basic prescription for strengthening and nourishing the spleen, with the effects of nourishing Qi and strengthening the spleen. In this experiment, human brain microvascular endothelial cells(HBMEC) and Sijunzi Decoction water extract(0.25, 0.5, 1 mg·L~(-1)) were pre-incubated for 2 h, and then Aβ_(25-35) oligomers(final concentration 40 μmol·L~(-1)) was added for co-culture for 22 hours. The effect of Sijunzi Decoction on the activity of Aβ_(25-35) oligomer injured cells and the expression of related proteins were investigated. Q-TOF-LC-MS was used first for principal component analysis of Sijunzi Decoction water extract. Then MTT assay was used to investigate the effect of Sijunzi Decoction water extract on the proliferation of HBMEC cells. Real-time fluorescence quantitative PCR(RT-qPCR) was employed to detect the mRNA expression of GLUT1, RAGE, and LRP1. The expression of Aβ-related proteins across blood-brain barrier(RAGE, LRP1) was detected by Western blot. The results showed that 40 μmol·L~(-1) Aβ_(25-35) oligomers could induce endothelial cell damage, reduce cell survival, increase expression of RAGE mRNA and RAGE protein, and reduce expression of GLUT1 mRNA, LRP1 mRNA, and LRP1 protein. Sijunzi Decoction water extract could reduce the Aβ_(25-35) oligomer-induced cytotoxicity of HBMEC, decrease the expression of RAGE mRNA and RAGE protein, and increase the expression of GLUT1 mRNA, LRP1 mRNA and LRP1 protein. The results indicated that Sijunzi Decoction could reduce the injury of HBMEC cells induced by Aβ_(25-35) oligomer, and regulate the transport-related proteins GLUT1, RAGE and LRP1, which might be the mechanism of regulating Aβ_(25-35) transport across the blood-brain barrier.

Risk factors and psychological impact of syncope in migraine patients.

BACKGROUND: Migraine is associated with syncope. We investigated risk factors for syncope and burden of syncope in migraine patients. METHODS: Participants were recruited from a headache clinic. All participants provided information on lifestyle, co-morbidity, syncope, headache and suicide, and completed the MIDAS and HADS questionnaires. Genetic data were available for a subset of participants. Risk of syncope in relation to participant's characteristics and migraine susceptibility loci, and risks of psychological disorders associated with syncope, were calculated using logistic regression. RESULTS: Underweight, regular tea intake, diabetes mellitus, and migraine with aura were associated with increased syncope risks, with adjusted ORs of 1.76 (95% CI 1.03-3.03), 1.84 (95% CI 1.22-2.79), 4.70 (95% CI 1.58-13.95), and 1.78 (95% CI 1.03-3.10), respectively. Preliminary results showed that rs11172113 in LRP1 was associated with syncope risks. Comorbid syncope in migraine patients was associated with increased risks of depression (OR 1.95, 95% CI 1.18-3.22) and suicide attempt (OR 2.85, 95% CI 1.48-5.48). CONCLUSION: Our study showed the potential roles of vascular risk factors in the association between migraine and syncope. Modifiable risk factors for syncope in patients with migraine include body mass index and tea intake. The debilitating psychological impact of co-morbid syncope in migraine patients warrants clinical attention of treating physicians.