In the present study, we transplanted adipose-derived mesenchymal stem cells into the hippo-campi of APP/PS1 transgenic Alzheimer’s disease model mice. Immunofluorescence staining revealed that the number of newly generated (BrdU+) cells in the subgranular zone of the dentate gyrus in the hippocampus was signiifcantly higher in Alzheimer’s disease mice after adipose-de-rived mesenchymal stem cell transplantation, and there was also a significant increase in the number of BrdU+/DCX+neuroblasts in these animals. Adipose-derived mesenchymal stem cell transplantation enhanced neurogenic activity in the subventricular zone as well. Furthermore, adipose-derived mesenchymal stem cell transplantation reduced oxidative stress and alleviated cognitive impairment in the mice. Based on these ifndings, we propose that adipose-derived mes-enchymal stem cell transplantation enhances endogenous neurogenesis in both the subgranular and subventricular zones in APP/PS1 transgenic Alzheimer’s disease mice, thereby facilitating functional recovery.

Tongluojiunao (TLJN) is an herbal medicine consisting of two main components, geniposide and ginsenoside Rg1. TLJN has been shown to protect primary cultured hippocampal neurons. How-ever, its mechanism of action remains unclear. In the present study, primary cultured hippocampal neurons treated with Aβ1-42 (10 μmol/L) signiifcantly increased the release of lactate dehydroge-nase, which was markedly reduced by TLJN (2 μL/mL), speciifcally by the component geniposide (26 μmol/L), but not ginsenoside Rg1 (2.5 μmol/L). hTe estrogen receptor inhibitor, ICI182780 (1 μmol/L), did not block TLJN-or geniposide-mediated decrease of lactate dehydrogenase under Aβ1-42-exposed conditions. However, the phosphatidyl inositol 3-kinase or mitogen-activated protein kinase pathway inhibitor, LY294002 (50 μmol/L) or U0126 (10 μmol/L), respectively blo cked the decrease of lactate dehydrogenase mediated by TLJN or geniposide. hTerefore, these results suggest that the non-classical estrogen pathway (i.e., phosphatidyl inositol 3-kinase or mitogen-activated protein kinase) is involved in the neuroprotective effect of TLJN, speciifcally its component, geniposide, against Aβ1-42-mediated cell death in primary cultured hippocampal neurons.

Yizhijiannao granules have been shown to improve cognitive function in Alzheimer’s disease patients. The present study sought to explore the mechanisms involved in the cognitive enhanc-ing effects ofYizhijiannao granule. Senescence-accelerated mouse prone 8 mice with learning and memory disorders were intragastrically treated withYizhijiannao granule for 8 weeks. Mice intragastrically treated with double distilled water for 8 weeks were considered as the control group. 2D gel electrophoresis was used to isolate total protein from the temporal lobe of senes-cence-accelerated mouse prone 8 mice, and differential protein spots were obtained by mass spectrometry. Thirty-seven differential protein spots were found in the temporal lobe area of both groups. Ten protein spots were identiifed: high mobility group box 1, dimethylarginine dimethylaminohydrolase-1, neuroglobin, hemoglobin beta adult major chain, peroxiredoxin-6, coiflin-1, lfotillin 1, peptidylprolyl isomerase A, voltage-dependent anion channel-2 and chap-eronin containing TCP1, and subunit 2. Among other functions, these proteins are separately involved in the regulation of amyloid beta production, oxidative stress, neuroinflammation, regulation of tau phosphorylation, and regulation of neuronal apoptosis. Our results revealed thatYizhijiannao granule can regulate the expression of various proteins in the temporal lobe of senescence-accelerated mouse prone 8 mice, and may be therapeutically beneifcial for the treat-ment of Alzheimer’s disease.

Cajal-Retzius cells are reelin-secreting neurons in the marginal zone of the neocortex and hip-pocampus. The aim of this study was to investigate Cajal-Retzius cells in Alzheimer’s disease pathology. Results revealed that the number of Cajal-Retzius cells markedly reduced with age in both wild type and in mice over-expressing the Swedish double mutant form of amyloid precur-sor protein 695 (transgenic (Tg) 2576 mice). Numerous reelin-positive neurons were positive for activated caspase 3 in Tg2576 mice, suggesting that Cajal-Retzius neuronal loss occurred via apoptosis in this Alzheimer’s disease model. Compared with wild type, the number of Cajal-Ret-zius cells was significantly lower in Tg2576 mice. Western blot analysis confirmed that reelin levels were markedly lower in Tg2576 mice than in wild-type mice. The decline in Cajal-Retzius cells in Tg2576 mice was found to occur concomitantly with the onset of Alzheimer’s disease am-yloid pathology and related behavioral deifcits. Overall, these data indicated that Cajal-Retzius cell loss occurred with the onset and development of Alzheimer’s disease.

Transforming growth factor-beta (TGF-β) type II receptor (TβRII) levels are extremely low in the brain tissue of patients with Alzheimer’s disease. This receptor inhibits TGF-β1/SMAD signaling and thereby aggravates amyolid-beta deposition and neuronal injury. Dab2, a speciifc adapter protein, protects TβRII from degradation and ensures the effective conduction of TGF-β1/SMAD signaling. In this study, we used an adenoviral vector to overexpress the Dab2 gene in the mouse hippocampus and investigated the regulatory effect of Dab2 protein on TGF-β1/SMAD signaling in a mouse model of Alzheimer’s disease, and the potential neuroprotective effect. The results showed that the TβRII level was lower in APP/PS1 mouse hippocampus than in normal mouse hippocampus. After Dab2 expression, hippocampal TβRII and p-SMAD2/3 levels were signiif-cantly increased, while amyloid-beta deposition, microglia activation, tumor necrosis factor-βand interleulin-6 levels and neuronal loss were signiifcantly attenuated in APP/PS1 mouse brain tissue. These results suggest that Dab2 can exhibit neuroprotective effects in Alzheimer’s disease by regulating TGF-β1/SMAD signaling.

Alzheimer’s disease is closely associated with disorders of neurogenesis in the brain, and growing evidence supports the involvement of immunological mechanisms in the development of the disease. However, at present, the role of T cells in neuronal regeneration in the brain is unknown. We injected amyloid-beta 1-42 peptide into the hippocampus of six BALB/c wild-type mice and six BALB/c-nude mice with T-cell immunodeifciency to establish an animal model of Alzhei-mer’s disease. A further six mice of each genotype were injected with same volume of normal saline. Immunohistochemistry revealed that the number of regenerated neural progenitor cells in the hippocampus of BALB/c wild-type mice was signiifcantly higher than that in BALB/c-nude mice. Quantitative fluorescence PCR assay showed that the expression levels of peripheral T cell-associated cytokines (interleukin-2, interferon-γ) and hippocampal microglia-related cyto-kines (interleukin-1β, tumor necrosis factor-α) correlated with the number of regenerated neural progenitor cells in the hippocampus. hTese results indicate that T cells promote hippocampal neurogenesis in Alzheimer’s disease and T-cell immunodeifciency restricts neuronal regeneration in the hippocampus. The mechanism underlying the promotion of neuronal regeneration by T cells is mediated by an increased expression of peripheral T cells and central microglial cytokines in Alzheimer’s disease mice. Our ifndings provide an experimental basis for understanding the role of T cells in Alzheimer’s disease.

The murine microglial cell line BV2 has neuroprotective effects, but is toxic to neurons by secret-ing inlfammatory cytokines, and is an important target in the treatment of nerve inlfammation and neurodegenerative diseases. In the present study, we observed the effects of transfecting three amyloid precursor-like protein 2 (APLP2) C-terminal fragments (CTFs; C57, C50 and C31) in the pEGFP-N1 vector on S100A9 expression in BV2 cells. Reverse transcription-PCR, western blot assay and immunocytochemistry revealed that S100A9 protein and mRNA expression was greater in BV2 cells after CTF transfection than after mock transfection with an empty vector. Furthermore, transfection of full-length APLP2-751 resulted in low levels of S100A9 protein ex-pression. Our results show that APLP2-CTFs upregulate S100A9 protein and mRNA expression in BV2 cells, and identify a novel pathway involved in neuronal injury and apoptosis, and repair and protection in Alzheimer’s disease.

3.0T magnetic resonance spectroscopic imaging is a commonly used method in the research of brain function in Alzheimer’s disease. However, the role of 7.0T high-ifeld magnetic resonance spectroscopic imaging in brain function of Alzheimer’s disease remains unclear. In this study, 7.0T magnetic resonance spectroscopy showed that in the hippocampus of Alzheimer’s disease rats, the N-acetylaspartate wave crest was reduced, and the creatine and choline wave crest was elevated. This ifnding was further supported by hematoxylin-eosin staining, which showed a loss of hippocampal neurons and more glial cells. Moreover, electron microscopy showed neuronal shrinkage and mitochondrial rupture, and scanning electron microscopy revealed small size hippocampal synaptic vesicles, incomplete synaptic structure, and reduced number. Overall, the results revealed that 7.0T high-ifeld nuclear magnetic resonance spectroscopy detected the lesions and functional changes in hippocampal neurons of Alzheimer’s disease rats in vivo, allowing the possibility for assessing the success rate and grading of the amyloid beta (1-40) animal model of Alzheimer’s disease.

Recent studies have demonstrated that Notch-1 expression is increased in the hippocampus of Alzheimer’s disease patients. We speculate that Notch-1 signaling may be involved in PC12 cell apoptosis induced by amyloid beta-peptide (25-35) (Aβ25-35). In the present study, PC12 cells were cultured with different doses (0, 0.1, 1.0, 10 and 100 nmol/L) of N-[N-(3,5-Dilfuorophen-acetyl)-L-alanyl]-S-phenylglycine t-butyl ester, a Notch-1 signaling pathway inhibitor, for 30 minutes. Then cultured cells were induced with Aβ25-35 for 48 hours. Pretreatment of PC12 cells with high doses of N-[N-(3,5-Dilfuorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (> 10 nmol/L) prolonged the survival of PC12 cells after Aβ25-35 induction, decreased the expression of apoptosis-related proteins caspase-3, -8, -9, increased the activity of oxidative stress-related su-peroxide dismutase and catalase, inhibited the production of active oxygen, and reduced nuclear factor kappa B expression. This study indicates that the Notch-1 signaling pathway plays a pivotal role in Aβ25-35-induced PC12 apoptosis.

Alzheimer’s disease is a neurodegenerative disorder characterized by progressive cognitive impairment and neuropathology. Recent preclinical and epidemiological studies proposed statins as a possible therapeutic drug for Alzheimer’s disease, but the exact mechanisms of action are stil unknown. Biliverdin reductase-A is a pleiotropic enzyme involved in cel ular stress responses. It not only transforms biliverdin-IX alpha into the antioxidant bilirubin-IX alpha but its serine/threonine/tyrosine kinase activity is able to modulate cel signaling networks. We previously reported the beneficial effects of atorvastatin treatment on biliverdin reductase-A and heme oxygenase-1 in the brains of a well characterized pre-clinical model of Alzheimer’s disease, aged beagles, together with observed improvement in cognition. Here we extend our knowledge of the effects of atorvastatin on inducible nitric oxide synthase in parietal cortex, cerebel um and liver of the same animals. We demonstrated that atorvastatin treatment (80 mg/day for 14.5 months) to aged beagles selectively increased inducible nitric oxide synthase in the parietal cortex but not in the cerebel um. In contrast, inducible nitric oxide synthase protein levels were significantly decreased in the liver. Significant positive correlations were found between biliverdin reductase-A and inducible nitric oxide synthase as wel as heme oxygenase-1 protein levels in the parietal cortex. The opposite was observed in the liver. Inducible nitric oxide synthase up-regulation in the parietal cortex was positively associated with improved biliverdin reductase-A functions, whereas the oxidative-induced impairment of biliverdin reductase-A in the liver negatively affected inducible nitric oxide synthase expression, thus suggesting a role for biliverdin reductase-A in atorvastatin-dependent inducible nitric oxide synthase changes. Interestingly, increased inducible nitric oxide synthase levels in the parietal cortex were not associated with higher oxidative/nitrosative stress levels. We hypothesize that biliverdin reductase-A-dependent inducible nitric oxide synthase regulation strongly contributes to the cognitive improvement observed fol owing atorvastatin treatment.

Screening humanized antibodies from a human Fab phage display library is an effective and quick method to obtain beta-amyloid oligomers. Thus, the present study prepared amyloid-beta 42 oli-gomers and constructed a na?ve human Fab phage display library based on blood samples from six healthy people. After three rounds of biopanning in vitro, a human single-domain antibody that spe-cifical y recognized amyloid-beta 42 oligomers was identified. Western blot and enzyme-linked immunosorbent assay demonstrated this antibody bound specifical y to human amyloid-beta 42 te-tramer and nonamer, but not the monomer or high molecular weight oligomers. This study suc-cessful y constructed a human phage display library and screened a single-domain antibody that specifical y recognized amyloid-beta 42 oligomers.

There are several major pathological changes in Alzheimer’s disease, including apoptosis of cho-linergic neurons, overactivity or overexpression ofβ-site amyloid precursor protein cleaving enzyme 1 (BACE1) and inflammation. In this study, we synthesized a 19-nt oligonucleotide targeting BACE1, the key enzyme in amyloid beta protein (Aβ) production, and introduced it into the pSilenCircle vector to construct a short hairpin (shRNA) expression plasmid against the BACE1 gene. We transfected this vector into C17.2 neural stem cells and primary neural stem cells, resulting in downregulation of the BACE1 gene, which in turn induced a considerable reduction in reducing Aβprotein production. We anticipate that this technique combining celltransplantation and gene ther-apy wil open up novel therapeutic avenues for Alzheimer’s disease, particularly because it can be used to simultaneously target several pathogenetic changes in the disease.

Amyloid β-peptide, a major component of senile plaques in Alzheimer’s disease, has been impli-cated in neuronal cel death and cognitive impairment. Recently, studies have shown that the pathogenesis of cerebral ischemia is closely linked with Alzheimer’s disease. In this study, a rat model of global cerebral ischemia-reperfusion injury was established via occlusion of four arteries;meanwhile, fibril ar amyloid β-peptide was injected into the rat lateral ventricle. The Morris water maze test and histological staining revealed that administration of amyloid β-peptide could further aggravate impairments to learning and memory and neuronal cel death in the hippocampus of rats subjected to cerebral ischemia-reperfusion injury. Western blot showed that phosphorylation of tau protein and the activity of glycogen synthase kinase 3β were significantly stronger in cerebral is-chemia-reperfusion injury rats subjected to amyloidβ-peptide administration than those undergoing cerebral ischemia-reperfusion or amyloidβ-peptide administration alone. Conversely, the activity of protein phosphatase 2A was remarkably reduced in rats with cerebral ischemia-reperfusion injury fol owing amyloidβ-peptide administration. These findings suggest that amyloidβ-peptide can po-tentiate tau phosphorylation induced by cerebral ischemia-reperfusion and thereby aggravate cog-nitive impairment.

To stop the progression of Alzheimer’s disease in the early stage, it is necessary to identify new therapeutic targets. We examined striatal-enriched phosphatase 61 expression in the brain tissues of 12-month-old APPswe/PSEN1dE9 transgenic mice. Immunohistochemistry showed that al-enriched phosphatase 61 protein expression was significantly increased but phosphorylated N-methyl-D-aspartate receptor 2B levels were significantly decreased in the cortex and hippocam-pus of APPswe/PSEN1dE9 transgenic mice. Western blotting of a cel model of Alzheimer’s disease consisting of amyloid-beta peptide (1-42)-treated C57BL/6 mouse cortical neurons in vitro showed that valeric acid (AP5), an N-methyl-D-aspartate receptor antagonist, significantly inhibited amyloid-beta 1-42-induced increased activity of striatal-enriched phosphatase 61. In addition, the phos-phorylation of N-methyl-D-aspartate receptor 2B at Tyr1472 was impaired in amyloid-beta 1-42-treated cortical neurons, but knockdown of striatal-enriched phosphatase 61 enhanced the phosphorylation of N-methyl-D-aspartate receptor 2B. Col ectively, these findings indicate that striatal-enriched phosphatase 61 can disturb N-methyl-D-aspartate receptor transport and inhibit the progression of learning and study disturbances induced by Alzheimer’s disease. Thus, al-enriched phosphatase 61 may represent a new target for inhibiting the progression of Alzheimer’s disease.

Neurodegenerative disorders affect more than 30 million individuals throughout the world and lead to signiifcant disability as well as death. These statistics will increase almost exponentially as the lifespan and age of individuals increase globally and individuals become more susceptible to acute disorders such as stroke as well as chronic diseases that involve cognitive loss, Alzheimer’s disease, and Parkinson’s disease. Current therapies for such disorders are effective only for a small subset of individuals or provide symptomatic relief but do not alter disease progression. One exciting therapeutic approach that may turn the tide for addressing neurodegenerative disorders involves the mammalian target of rapamycin (mTOR). mTOR is a component of the protein complexes mTOR Complex 1 (mTORC1) and mTOR Complex 2 (mTORC2) that are ubiquitous throughout the body and control multiple functions such as gene transcription, metabolism, cell survival, and cell senescence. mTOR through its relationship with phosphoinositide 3-kinas e (PI 3-K) and protein kinase B (Akt) and multiple downstream signaling pathways such as p70 ribosomal S6 kinase (p70S6K) and proline rich Akt substrate 40 kDa (PRAS40) promotes neuro-nal cell regeneration through stem cell renewal and oversees critical pathways such as apoptosis, autophagy, and necroptosis to foster protection against neurodegenerative disorders. Targeting by mTOR of speciifc pathways that drive long-term potentiation, synaptic plasticity, andβ-amyl oid toxicity may offer new strategies for disorders such as stroke and Alzheimer’s disease. Overall, mTOR is an essential neuroprotective pathway but must be carefully targeted to maximize clini-cal efifcacy and eliminate any clinical toxic side effects.

The Alzheimer’s disease model in Wistar rats was established by injection of amyloid β-peptide (Aβ1-42 ) into the hippocampal CA1 region. Rats were treated with suspended moxibustion on Baihui (GV20) and Shenshu (BL23) acupoints. Prior to and post Aβ1-42 exposure. Results showed no evidence of apoptosis in hippocampal neurons, a significantly reduced apoptosis rate of neurons and improved learning and memory abilities were observed in the Alzheimer’s disease model. In particular, moxibustion prior to Aβ1-42 exposure was more effective than moxibustion after Aβ1-42 exposure in protecting the neuronal structure and lowering the apoptosis rate. Our findings indicate that a combination of preventive and therapeutic moxibustion has a beneficial effect for the tion of Alzheimer’s disease development.

A correlation between metabolic alterations of neuroactive steroids and Alzheimer’s disease remains unknown. In the present study, amyloid beta (Aβ) 25-35 (Aβ25-35) injected into the bilateral campus CA1 region significantly reduced learning and memory. At the biochemical level, hippocampal levels of pregnenolone were significantly reduced with Aβ25-35 treatment. Furthermore, progesterone was considerably decreased in the prefrontal cortex and hippocampus, and 17β-estradiol was signifi-cantly elevated. To our knowledge, this is the first report showing that Aβ25-35, a main etiological factor of Alzheimer’s disease, can alter the level and metabolism of neuroactive steroids in the prefrontal cortex and hippocampus, which are brain regions significantly involved in learning and memory. Aβ25-35 exposure also increased the expression of inflammatory mediators, tumor necrosis factor-αand interleukin-1β. However, subcutaneous injection of progesterone reversed the upregulation of tumor necrosis factor-αand interleukin-1βin a dose-dependent manner. Concomitant with improved cognitive abilities, progesterone blocked Aβ-mediated inflammation and increased the survival rate of hippocampal pyramidal cells. We thus hypothesize that Aβ-mediated cognitive deficits may occur via changes in neuroactive steroids. Moreover, our findings provide a possible therapeutic strategy for Alzheimer’s disease via neuroactive steroids, particularly progesterone.

To enhance anti-amyloid-beta (Aβ) antibody generation and induce a Th2 immune response, we constructed a new DNA vaccine p(Aβ3-10 )10-C3d-p28.3 encoding ten repeats of Aβ3-10 and three copies of C3d-p28 as a molecular adjuvant. In this study, we administered this adjuvant intramus-cularly to female C57BL/6J mice at 8-10 weeks of age. Enzyme linked immunosorbent assay was used to detect the titer of serum anti-Aβ antibody, isotypes, and cytokines in splenic T cel s. A 3-(4,5-cimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay was used to detect the prolifera-tion rate of splenic T cel s. Brain sections from a 12-month-old APP/PS1 transgenic mouse were used for detecting the binding capacities of anti-Aβ antibodies to Aβ plaques. The p(Aβ3-10)10-C3d-p28.3 vaccine induced high titers of anti-amyloid-βantibodies, which bound to Aβplaques in APP/PS1 transgenic mouse brain tissue, demonstrating that the vaccine is effective against plaques in a mouse model of Alzheimer’s disease. Moreover, the vaccine elicited a pre-dominantly IgG1 humoral response and low levels of interferon-γ in ex vivo cultured splenocytes, indicating that the vaccine could shift the cel ular immune response towards a Th2 phenotype. This indicated that the vaccine did not elicit a detrimental immune response and had a favorable safety profile. Our results indicate that the p(Aβ3-10)10-C3d-p28.3 vaccine is a promising immunothera-peutic option for Aβvaccination in Alzheimer’s disease.

Humanin is a potential therapeutic agent for Alzheimer’s disease, and its derivative, S14G-humanin, is 1 000-fold stronger in its neuroprotective effect against Alzheimer’s disease-relevant insults. Alt-hough effective, the detailed molecular mechanism through which S14G-humanin exerts its effects remains unclear. Data from this study showed that fibril ar amyloid-beta 40 disturbed cel ular ho-meostasis through the cel membrane, increasing intracel ular calcium, generating reactive oxygen species, and decreasing the mitochondrial membrane potential. S14G-humanin restored these re-sponses. The results suggested that S14G-humanin blocked the effects of amyloid-beta 40 on the neuronal cel membrane, and restored the disturbed cel ular homeostasis, thereby exerting a neuroprotective effect on hippocampal neurons.

Current evidence shows that apolipoprotein E (APOE), apolipoprotein CI (APOC1) and low density lipoprotein receptor-related protein (LRP) variations are related to late-onset Alzheimer’s disease. However, it remains unclear if genetic polymorphisms in these genes are associated with cognitive decline in late-onset Alzheimer’s disease patients. We performed a 30-month longitudi-nal cohort study to investigate the relationship between Alzheimer’s disease and APOE, APOC1, and LRP. In this study, 78 Chinese Han patients with late-onset Alzheimer’s disease were recruit-ed form Guangxi Zhuang Autonomous Region in China. APOE, APOC1, and LRP genotyping was performed using polymerase chain reaction-restriction fragment length polymorphisms. The Mini-Mental State Examination and Clinical Dementia Rating Scale were used to assess pa-tients’ cognitive function. After a 30-month follow-up period, we found a signiifcant reduction in Mini-Mental State Examination total score, a higher proportion of patients fuliflling cognitive impairment progression criteria, and a higher proportion of APOC1 H2 carriers in APOEε4 carriers compared with non-carriers. In addition, the APOEε4 allele frequency was signiifcantly higher in the cognitive impairment progression group compared with the non-cognitive im-pairment progression group. In conclusion, APOEε4 plays an important role in augmenting cognitive decline, and APOC1 H2 may act synergistically with APOEε4 in increasing the risk of cognitive decline in Chinese patients with late-onset Alzheimer’s disease.