Inhibiting α1-adrenergic receptor signaling pathway ameliorates AD-type pathologies and behavioral deficits in APPswe/PS1 mouse model.

The role of α1 adrenergic receptors (α1-ARs) signaling pathway in the pathogenesis of Alzheimer's disease (AD) has rarely been investigated. Clarifying the pathophysiological functions of α1-ARs in the AD brain is helpful for better understanding the pathogenesis and screening novel therapeutic targets of AD. This study included 2 arms of in vivo investigations: 1) 6-month-old female APPswe/PS1 mice were intravenously treated with AAV-PHP.eB-shRNA (α1-ARs)-GFP or AAV-PHP.eB-GFP for 3 months. 2) 3-month-old female APPswe/PS1 mice were daily treated with 0.5 mg/kg terazosin or an equal volume of saline for 6 months. SH-SY5Y cell lines bearing human amyloid precursor protein were treated with terazosin or saline for investigating possible mechanisms. α1-ARs knockdown mice exhibited improved behavioral performances in comparison with control mice. α1-ARs knockdown mice had significantly lower brain amyloid burden, as reflected by soluble Aß species, compact and total Aß plaques, than control mice. α1-ARs inhibitor terazosin substantially reduced Aß deposition, attenuated downstream pathologies including tau hyperphosphorylation, glial activation, neuronal loss, synaptic dysfunction et al., and rescued behavioral deficits in APPswe/PS1 mice. In vitro investigation demonstrated that α1-ARs inhibition down-regulated BACE1 expression, and promoted ser9 phosphorylation of GSK-3ß, thus reducing Aß production. This study indicates that inhibition of α1-ARs signaling pathway might represent a promising therapeutic strategy for AD.

Blood cell-produced amyloid-ß induces cerebral Alzheimer-type pathologies and behavioral deficits.

It is traditionally believed that cerebral amyloid-beta (Aß) deposits are derived from the brain itself in Alzheimer's disease (AD). Peripheral cells such as blood cells also produce Aß. The role of peripherally produced Aß in the pathogenesis of AD remains unknown. In this study, we established a bone marrow transplantation model to investigate the contribution of blood cell-produced Aß to AD pathogenesis. We found that bone marrow cells (BMCs) transplanted from APPswe/PS1dE9 transgenic mice into wild-type (Wt) mice at 3 months of age continuously expressed human Aß in the blood, and caused AD phenotypes including Aß plaques, cerebral amyloid angiopathy (CAA), tau hyperphosphorylation, neuronal degeneration, neuroinflammation, and behavioral deficits in the Wt recipient mice at 12 months after transplantation. Bone marrow reconstitution in APPswe/PS1dE9 mice with Wt-BMCs at 3 months of age reduced blood Aß levels, and alleviated brain Aß burden, neuronal degeneration, neuroinflammation, and behavioral deficits in the AD model mice at 12 months after transplantation. Our study demonstrated that blood cell-produced Aß plays a significant role in AD pathogenesis, and the elimination of peripheral production of Aß can decrease brain Aß deposition and represents a novel therapeutic approach for AD.

Physiological clearance of amyloid-beta by the kidney and its therapeutic potential for Alzheimer's disease.

Amyloid-ß (Aß) accumulation in the brain is a pivotal event in the pathogenesis of Alzheimer's disease (AD), and its clearance from the brain is impaired in sporadic AD. Previous studies suggest that approximately half of the Aß produced in the brain is cleared by transport into the periphery. However, the mechanism and pathophysiological significance of peripheral Aß clearance remain largely unknown. The kidney is thought to be responsible for Aß clearance, but direct evidence is lacking. In this study, we investigated the impact of unilateral nephrectomy on the dynamic changes in Aß in the blood and brain in both humans and animals and on behavioural deficits and AD pathologies in animals. Furthermore, the therapeutic effects of the diuretic furosemide on Aß clearance via the kidney were assessed. We detected Aß in the kidneys and urine of both humans and animals and found that the Aß level in the blood of the renal artery was higher than that in the blood of the renal vein. Unilateral nephrectomy increased brain Aß deposition; aggravated AD pathologies, including Tau hyperphosphorylation, glial activation, neuroinflammation, and neuronal loss; and aggravated cognitive deficits in APP/PS1 mice. In addition, chronic furosemide treatment reduced blood and brain Aß levels and attenuated AD pathologies and cognitive deficits in APP/PS1 mice. Our findings demonstrate that the kidney physiologically clears Aß from the blood, suggesting that facilitation of Aß clearance via the kidney represents a novel potential therapeutic approach for AD.

Rejuvenation of peripheral immune cells attenuates Alzheimer's disease-like pathologies and behavioral deficits in a mouse model.

Immunosenescence contributes to systematic aging and plays a role in the pathogenesis of Alzheimer's disease (AD). Therefore, the objective of this study was to investigate the potential of immune rejuvenation as a therapeutic strategy for AD. To achieve this, the immune systems of aged APP/PS1 mice were rejuvenated through young bone marrow transplantation (BMT). Single-cell RNA sequencing revealed that young BMT restored the expression of aging- and AD-related genes in multiple cell types within blood immune cells. The level of circulating senescence-associated secretory phenotype proteins was decreased following young BMT. Notably, young BMT resulted in a significant reduction in cerebral Aß plaque burden, neuronal degeneration, neuroinflammation, and improvement of behavioral deficits in aged APP/PS1 mice. The ameliorated cerebral amyloidosis was associated with an enhanced Aß clearance of peripheral monocytes. In conclusion, our study provides evidence that immune system rejuvenation represents a promising therapeutic approach for AD.

Improving Blood Monocyte Energy Metabolism Enhances Its Ability to Phagocytose Amyloid-ß and Prevents Alzheimer's Disease-Type Pathology and Cognitive Deficits.

Deficiencies in the clearance of peripheral amyloid ß (Aß) play a crucial role in the progression of Alzheimer's disease (AD). Previous studies have shown that the ability of blood monocytes to phagocytose Aß is decreased in AD. However, the exact mechanism of Aß clearance dysfunction in AD monocytes remains unclear. In the present study, we found that blood monocytes in AD mice exhibited decreases in energy metabolism, which was accompanied by cellular senescence, a senescence-associated secretory phenotype, and dysfunctional phagocytosis of Aß. Improving energy metabolism rejuvenated monocytes and enhanced their ability to phagocytose Aß in vivo and in vitro. Moreover, enhancing blood monocyte Aß phagocytosis by improving energy metabolism alleviated brain Aß deposition and neuroinflammation and eventually improved cognitive function in AD mice. This study reveals a new mechanism of impaired Aß phagocytosis in monocytes and provides evidence that restoring their energy metabolism may be a novel therapeutic strategy for AD.

Physiological clearance of Aß by spleen and splenectomy aggravates Alzheimer-type pathogenesis.

BACKGROUND: A previous study demonstrated that nearly 40%-60% of brain Aß flows out into the peripheral system for clearance. However, where and how circulating Aß is cleared in the periphery remains unclear. The spleen acts as a blood filter and an immune organ. The aim of the present study was to investigate the role of the spleen in the clearance of Aß in the periphery. METHODS: We investigated the physiological clearance of Aß by the spleen and established a mouse model of AD and spleen excision by removing the spleens of APP/PS1 mice to investigate the effect of splenectomy on AD mice. RESULTS: We found that Aß levels in the splenic artery were higher than those in the splenic vein, suggesting that circulating Aß is cleared when blood flows through the spleen. Next, we found that splenic monocytes/macrophages could take up Aß directly in vivo and in vitro. Splenectomy aggravated behaviour deficits, brain Aß burden and AD-related pathologies in AD mice. CONCLUSION: Our study reveals for the first time that the spleen exerts a physiological function of clearing circulating Aß in the periphery. Our study also suggests that splenectomy, which is a routine treatment for splenic rupture and hypersplenism, might accelerate the development of AD.

Effects of Chemotherapy on Neuroinflammation, Neuronal Damage, Neurogenesis, and Behavioral Performance in Bone Marrow Transplantation Recipient Mice.

As bone marrow transplant (BMT) is gradually applied to the study of central nervous system (CNS) disease, it is needed to investigate the proper dose of chemotherapy to eradicate bone marrow cells while bringing little damage to brain. In the present study, we established a BMT model with varied busulfan and cyclophosphamide (Bu-Cy) dosages. The recipient mice's chimera rate, neuronal death, neuroinflammation, and behavioral functions were all investigated. Chimerism of peripheral blood cells was shown to rise with Bu-Cy treatment doses, with 60.7% in the Bu(20 mg/kg)/Cy(100 mg/kg) group and 93.0% in the Bu(35 mg/kg)/Cy(100 mg/kg) group. Recipients with Bu(35 mg/kg)/Cy(100 mg/kg) therapy had brain injury, increased neuroinflammation, diminished neurogenesis and cognitive abnormalities, whereas animals given a lesser dosage had no such brain damages. Conclusively, considering the chimerism and the possibility to damage brain, we recommend Bu(20 mg/kg)/Cy(100 mg/kg) is the ideal dose in BMT for studying CNS diseases in the C57/BL6 mouse strain.

Naturally Occurring Antibodies to Tau Exists in Human Blood and Are Not Changed in Alzheimer's Disease.

Hyperphosphorylated tau is an important pathological agent in Alzheimer's disease (AD). Tau effluxes from the brain to the blood could potentially stimulate the production of naturally occurring antibodies (NAbs). We aimed to investigate whether NAbs to tau (NAbs-tau) was generated in human blood and to figure out the alteration of plasma NAbs-tau level in AD patients. About 192 AD patients and 192 age-matched and non-demented controls (NC) were enrolled in the present study. Immunofluorescence staining and western blot assays were used to confirm the existence of NAbs-tau in human blood. The plasma level of NAbs-tau in NC and AD group was analyzed by ELISA. Immunofluorescence staining and western blot assays confirmed the existence of NAbs-tau in human blood. However, no significant difference in the plasma level of NAbs-tau was observed between NC and AD group. Furthermore, the plasma level of NAbs-tau had no significant correlation with MMSE scores. The present study confirmed that NAbs-tau exists in human blood but does not differ in level between the NC and AD group. Plasma NAbs-tau is not a reliable biomarker for AD.

Low-photon-number optical switch and AND/OR logic gates based on quantum dot-bimodal cavity coupling system.

We propose a new scheme based on quantum dot-bimodal cavity coupling system to realize all-optical switch and logic gates in low-photon-number regime. Suppression of mode transmission due to the destructive interference effect is theoretically demonstrated by driving the cavity with two orthogonally polarized pulsed lasers at certain pulse delay. The transmitted mode can be selected by designing laser pulse sequence. The optical switch with high on-off ratio emerges when considering one driving laser as the control. Moreover, the AND/OR logic gates based on photon polarization are achieved by cascading the coupling system. Both proposed optical switch and logic gates work well in ultra-low energy magnitude. Our work may enable various applications of all-optical computing and quantum information processing.

[Effects of low molecular weight heparin on vascular endothelial growth factor expression of early diabetic nephropathy].

OBJECTIVE: To investigate the effects of low molecular weight heparin (LMWH) on vascular endothelial growth factor (VEGF) expression of early diabetic nephropathy. METHODS: Ninety-five male SD rats were randomly divided into three groups: normal control rats, STZ-induced diabetic rats and diabetic rats treated with LMWH. The renal tissues were subjected to immunohistochemical staining after 1, 2, 4, 6, and 8 weeks' treatment respectively to quantify the VEGF expression. RESULTS: Immunohistochemical staining demonstrated an increasing in VEGF positive cells in diabetic rats. It was found that there were significant differences in VEGF staining intensity between diabetic rats and normal control rats and between LMWH treated rats and untreated diabetic rats after two weeks treatment. CONCLUSION: The inhibition of VEGF expression may be one of the mechanisms of LMWH's renal protective effects on early diabetic nephropathy.

[Clinical features of Wei Yuheng].

Wei Yuheng held that the endogenous miscellaneous diseases are mostly caused by liver diseases, highly stressed the treating method of nourishing yin to generate liver. He claimed that liver deficiency is mostly caused by congenital factors, sexual strain or improper treatment. He criticized that the improper treatment by elder generations mainly was caused by their ignorance of tonifying the liver based on the saying of "no tonifying treatment for the liver". Wei Yuheng's medical theories and clinical experiences are scattered in his book Xu Mingyi Lei'an (Supplement to Classified Case Records of Celebrated Physicians). Wang Mengying collected part of his thoughts and experiences and wrote the book Liuzhou Yihua (Liuzhou Medical Talks). Although Wang Mengying's book could deduce part of the thoughts of Wei Yuheng, it didn't disclose his theories completely. It is known to all that the compound recipe Yiguan Jian is a representative formula of Wei Yuheng to tonify liver yin. Actually, it can be concluded from the analysis of Xu Mingyi Lei'an that he used Fructus Lycii (Gouqi) as a main herb to tonify liver yin in the method of nourishing yin to generate liver. Based on the idea that there are accept, restriction, generation and transformation relationship among the lung, kidney and liver yin, so he also always used Radix Glehniae (Beishashen), Radix Ophiopogonis (Maidong), Radix Rehmanniae Recens (Shengdihuang), and Radix Rehmanniae Preparata (Shudihuang) in his compound recipes. If the yin blood is insufficient, Semen Ziziphi Spinosae (Suanzaoren) should be added. In order to prepare a out way for phlegm-heat caused dy liver yin deficiency, a lubricative, Semen Trichosanthis (Gualouren) was always used and raw Semen Coicis Recens (Shengyiyiren) too. Sichuan Rhizoma Coptidis (Chuanhuanglian) can be used to clear fire-heat, and Fructus Meliae Toosendan (Chuanlianzi) for pain caused by fire-heat.