[Verification of a sporadic Alzheimer disease model in SORL1 gene knockout mice].

OBJECTIVE: To compare the behavioral and pathological features of SORL1 gene knockout mice with those of normal mice and APP/PSE1 mice to verify the feasibility of using SORL1 knockout mice as a model of sporadic Alzheimer disease. METHODS: SORL1 gene of fertilized mouse eggs were edited using Crispr/Case9 technique. SORL1-/- mice were screened and identified by detecting the DNA sequence, and Western blotting was used to detect the expression of SORL1. SORL1-/- mice, control mice and APP/PSE1 mice all underwent Morris water maze test to assess their learning and memory abilities with positioning navigation and space exploration experiments. The expression of APP and Aß in the brain of the mice was detected using immunohistochemistry and Western blotting, respectively. RESULTS: DNA sequencing showed CAAT deletion in SORL1 gene in two chromosomes of SORL1-/- mice, and the control mice had intact SORL1 gene without the deletion; Western blotting did not detect the expression of the SORL1 in the brain of SORL1-/- mice. Morris water maze test showed that in positioning navigation experiment, the average avoidance latency was similar between SORL1-/- mice and APP/PSE1 mice (P>0.05) but increased significantly in both mice as compared with the control group (P<0.05); similar results were obtained in the space exploration experiment. Immunohistochemistry and Western blotting revealed significantly increased APP and Aß expression in the brain tissue of both SORL1-/- mice and APP/PSE1 mice compared with the control mice without significant differences between the two transgenic mice. CONCLUSION: SORL1-/- mice exhibit similar behavioral and pathological changes with APP/PSE1 mice and can be used as a model of sporadic Alzheimer's disease.

Role of miR-181a in the process of apoptosis of multiple malignant tumors: A literature review.

It has been recognized that miR-181a expression is dysregulated and intimately associated with clinical prognosis in a variety of human cancers. However, the direct role of miR-181a in tumor progression has been elusive. Moreover, mounting evidence has demonstrated that cellular apoptosis, a physiological process of programmed cell death, is disrupted in various categories of human malignancies. Multiple apoptosisrelated genes have been proven to act as the target genes of miR-181a. In this study, we hypothesize that miR-181a probably plays a potential role in modulating the procession and apoptosis of cancer cells. We performed a literature review and elucidated how miR-181a modulated cellular apoptosis, especially the malignant neoplasm cells. We also unraveled the potential role of miR-181a in the diagnosis, treatment and clinical prognosis of multiple human malignancies - miR-181a plays a pivotal role in the development, treatment and prognosis of patients suffering from malignant tumors. It also participates in the development of cancer partially by modulating cellular apoptosis.

[Protective effect of butylphthalide in a cell model of Alzheimer's disease induced by Aß25-35 in Neuro 2a cells].

OBJECTIVE: To study the protective effect of butylphthalide in a cell model of Alzheimer's disease(AD) induced by Aß25-35 in Neuro 2a (N2a) cells. METHODS: N2a cells were divided into AD group, butylphthalide (NBP) group and control group. AD cell model was established by adding 20 µmol/L Aß25-35 to cultured N2a cells. The cells in NBP group were treated with 0.1, 1, 10, or 100 µmol/L NBP 4 h prior to treatment with 20 µmol/L Aß25-35. The cell viability were determined by MTT assay, the cell apoptotic rate were detected by AnnexinV-FITC flow cytometry, and the cell morphological changes were observed under inverted phase contrast microscope. The expression of TNF-α and IL-1ß mRNA were determined by qRT-PCR. RESULTS: Compared with those in the control group, the number of adherent cells was significantly decreased, neurite structures were reduced, and the cell viability was decreased, while the apoptotic rate and expressions of TNF-α and IL-1ß mRNA were increased in AD group (P<0.05). Compared with that in AD group, the number of adherent cells was increased in NBP group and the cell morphology was similar to the normal control cells. The cell viability of N2a cells was increased in NBP group with decreased apoptotic rate and expression of TNF-αand IL-1ß mRNA (P<0.05). CONCLUSION: Butylphthalide can protect against AD in the cell model induced by Aß25-35 possibly by inhibiting the expression of inflammatory cytokines.

Role of ABC transporters in the pathology of Alzheimer's disease.

The ATP-binding cassette (ABC) transporter superfamily is a large family of proteins that transport specific molecules across membranes. These proteins are associated with both cholesterol metabolism and Alzheimer's disease (AD). Cholesterol homeostasis has a key role in AD, and ABC transporters are important mediators of lipid transportation. Emerging evidence suggests that decreased expression and hypofunction of ABC transporters are crucial to the occurrence and development of AD. In the present article, we review the current knowledge regarding ABC transporters and speculate on their role in the pathogenesis of AD.

[Correlation between serum adiponectin level and cognitive function in patients with Alzheimer's disease].

OBJECTIVE: To investigate serum adiponectin level in patients with Alzheimer's disease (AD) and its correlation with the patients' cognitive function. METHODS: This case-control study was conducted in 90 patients with a highly probable diagnosis ofAD, who were divided into mild, moderate and severe group saccording to the MMSE score. Ninety healthy subjects matched for age and gender with the AD patients were selected as the control group. The serum levels ofadiponectin in the participants were detected using enzyme-linked immunosorbent assay. RESULTS: Serum adiponectin level was significantly lower in the AD group than in the control group (P<0.05). Of the 3 subgroups of the AD patients, the moderate and severe AD groups showed significantly lower serum adiponectin level sthan the control group (P<0.05), but the difference in adiponectin levels was not significant between the mild AD group and the control group (P>0.05); serum adiponectin levels also differed significantly among the 3 subgroups of AD patients (P<0.05). Serum adiponectin level was positively correlated with the MMSE score in the AD patients (r=0.683, P<0.001). CONCLUSION: Serum adiponectin levels are reduced in AD patients and associated with the degree of cognitive impairment.

Mir-181b Functions as Anti-Apoptotic Gene in Post-Status Epilepticus via Modulation of Nrarp and Notch Signaling Pathway.

BACKGROUND: The expression pattern and function of miRs in the post-status epilepticus (SE) rat are still unclear. This study aimed to investigate the role and mechanism of miR-181b in the post- SE rat. METHODS: The lithium-pilocarpine-induced SE model was established in Sprague-Dawley rats. The expression of miR-181b in rat blood and hippocampus was confirmed by RT-PCR at 24 hous and 7 days post-SE. The expression of Nrarp, Hes-1, and Bcl-2 was detected by RT-PCR and western blot. After the rat model was treated with LV-rno-mir181b and LV-anti-181b-5p, the expression change of miR-181b, Nrarp, Hes-1, and Bcl-2 was examined again. The effects of altering the expression of miR-181b on neurone cell apoptosis post-SE were assessed. RESULTS: The expression of miR-181b significantly decreased both in post-SE rat hippocampus and peripheral blood at 24 hours and 7 days (p<0.05). Nrarp is up-regulated, however, Hes-1 and Bcl-2 are down-regulated (p<0.05). LV-miR-181b treatment induced down-regulation of Nrarp and up-regulation of Hes-1 and Bcl-2 (p<0.05). Neurone cell apoptosis decreased in miR-181b group and post-SE rat hippocampal (p<0.05). CONCLUSIONS: Our study showed the low-expression of miR-181b in the hippocampus in a post-SE rat model. MiR-181b negatively regulated Nrarp as an anti-apoptotic gene via Notch signaling pathway.

[Association between angiotensin-converting enzyme gene polymorphism and Alzheimer's disease].

OBJECTIVE: To determine the association between the polymorphism of angiotensin converting enzyme (ACE) gene and Alzheimer's disease (AD). METHODS: This case-control study involved 201 AD patients and 257 healthy subjects matched for age and gender as the control group. Polymerase chain reaction amplification and matrix-assisted laser desorption/ ionization time of flight mass spectrometry were used to examine the rs4291, rs4309, and rs4343 of ACE gene, and the difference in genotypes, allelotype frequencies and haplotype frequencies were analyzed between the two groups. RESULTS: No statistic difference was found in the genotype and allelotype frequencies of rs4291 locus between AD and control groups (P>0.05). A significant difference was found in the genotype and allelotype frequencies of rs4309 between the two groups with a significant increase in the C allelotype frequency in AD group (OR=1.917, 95% CI=1.431-2.568, P<0.05). The difference in the genotype frequency of rs4343 was not significant between the two groups, but the allelotype frequencies differed significantly with a decreased A allelotype frequency in AD group(OR=0.714, 95% CI=0.532-0.957, P=0.024). Analysis of the linkage disequilibrium among the loci of rs4291, rs4309 and rs4343 showed a D' all above 0.65 between one another. Haplotype analysis confirmed the existence of 5 haplotypes, namely ATA, ACA, TCA, TCG and TTG, indicating a negative correlation between haplotype ATA and AD occurrence (OR=0.558, 95% CI=0.420-0.741, P<0.05) and positive correlations of haplotype ACA and TCA with AD occurrence (ACA: OR=4.883, 95% CI=2.267-10.518, P<0.05; TCA: OR=2.269, 95% CI=1.083-4.754, P<0.05). CONCLUSION: The polymorphism of rs4291 may have no relation with the incidence of AD. Polymorphisms of s4309 and rs4343 may be related to AD, and ATA, ACA and TCA haplotypes composed of rs4291/rs4309/rs4343 may be related to AD.

Relationship between Adiponectin Gene Polymorphisms and Late-Onset Alzheimer's Disease.

In recent years, researchers have found that adiponectin (ANP) plays an important role in the pathogenesis of Alzheimer's disease (AD), and low serum concentrations of ANP are associated with AD. Higher plasma ANP level have a protective effect against the development of cognitive decline, suggesting that ANP may affect AD onset. Meanwhile, accumulating evidence supports the crucial role of ANP in the pathogenesis of AD. To study the relationship between ANP gene polymorphisms (rs266729, -11377C>G and rs1501299, G276T) and late-onset AD (LOAD), we carried out a case-control study that included 201 LOAD patients and 257 healthy control subjects. Statistically significant differences were detected in the genotype and allelotype frequency distributions of rs266729 and rs1501299 between the LOAD group and the control group, with a noticeable increase in the G and T allelotype frequency distributions in the LOAD group (P < 0.05). Logistic regression analysis using recessive model and additive model revealed that the rs266729 GG and rs1501299 TT genotypes are associated with a greater risk of LOAD. Haplotype analysis identified four haplotypes: CG, CT, GG, and GT. The frequencies of the CT and GG haplotypes were not significantly different (P > 0.05) between the LOAD group and control group, whereas the CG and GT haplotypes were significantly different (P < 0.05), suggesting a negative correlation between the CG haplotype and LOAD onset (OR = 0.74, 95% CI = 0.57-0.96, P = 0.022), and a positive correlation between the GT haplotype and LOAD onset (OR = 2.29, 95% CI = 1.42-3.68, P = 0.005). Therefore, we speculated that the rs266729 and rs1501299 of ANP gene polymorphisms and the GT and CG haplotypes were associated with LOAD.

Relationship between the gene polymorphisms of kallikrein-kinin system and Alzheimer's disease in a Hunan Han Chinese population.

This study aimed to determine the connection between polymorphisms of kallikrein kinin system including KLK1 (rs5516), KNG1 (rs710446, rs2304456) and ACE (rs4291, rs4309, rs4343) and late-onset Alzheimer's disease (LOAD). The research was conducted as a case-control study, comprising 201 AD patients in the AD group, and 257 healthy subjects as the control group. PCR amplification and matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) were used to detect the six polymorphisms (rs5516 in KLK1; rs710446, rs2304456 in KNG1; rs4291, rs4309, rs4343 in ACE) from both groups. No statistically significant difference was found between the genotype and allelotype distributions of rs5516, rs710446, rs2304456, rs4291 and rs4343 (P>0.05). The differences between the genotype and allelotype distributions of the rs4309 were statistically significant (P<0.05). Haplotype analysis confirmed the existence of three haplotypes (AG, AT, GT) composed of rs710446/rs2304456, and six haplotypes (ATA, ACA, TCA, TCG, TTA, TTG) composed of rs4291/rs4309/rs4343, among which the distribution of ATA, ACA, TCA between the two groups was statistically significant difference (P<0.05). Our study showed that the polymorphisms of rs5516, rs710446, rs2304456, rs4291 and rs4343 is not related to the incidence of LOAD. The polymorphisms of rs4309 may be related to LOAD, as well as ATA, ACA, and TCA haplotype composed of rs4291/rs4309/rs4343.

SORL1 gene polymorphism association with late-onset Alzheimer's disease.

We examined the relationship between loci polymorphisms (rs689021, rs3824966, and rs1784933) of the sortilin-related receptor 1 gene (SORL1) and late-onset Alzheimer's disease (LOAD) in the Chinese Han population of the Hunan Changsha region. A case-control association analysis was used. Clinical data and peripheral blood were collected from 201 Alzheimer's disease patients and 257 healthy controls. PCR and MALDI-TOF mass spectrometry detection technologies were used to identify single nucleotide polymorphism (SNP) distribution at SORL1 gene loci. Genotype and allele frequency differences were analyzed and compared between groups. No significant differences were found in genotype frequency distributions of the rs689021 and rs3824966 loci. Similarly, allele frequency distributions of the C and T alleles of rs689021, and the C and G alleles of rs3824966 showed no significant differences. However, the genotype frequency distribution of the rs1784933 locus was significantly different, and the allele frequency distribution of the A and G alleles were also significantly different. Multifactor logistic regression analysis showed that after correcting for confounding factors such as gender, age, and cholesterol, LOAD risk in rs1784933 AA genotype carriers was 1.803 times that in AG+GG genotype carriers. SORL1 gene SNPs at rs689021 and rs3824966 loci show no relationship with LOAD onset in the Chinese Han population of the Hunan Changsha region. Conversely, a SORL1 gene SNP at the rs1784933 locus is associated with LOAD onset, with the A allele being a risk factor.

[ß-amyloid peptide deposition and expression of related miRNAs in the cerebellum of a mouse model of Alzheimer's disease].

OBJECTIVE: To investigate the presence of ß-amyloid peptide (Aß) deposition in the cerebellum and the expression of related miRNAs in the cerebellum of a mouse model of Alzheimer disease. METHODS: Twelve 12-month-old APPswe/PSδE9 double transgenic mice and 12 wild-type C57 mice were sacrificed and the brain tissues were taken for examination. The right hemisphere was stained with Congo red to observe the deposition of amyloid substances, and from the left hemisphere, the hippocampus and the cerebellum were dissected for detecting the expression of miRNA-135a-5p, miRNA-298-5p, miRNA-466b-3p and miR-669f-3p using real-time PCR. RESULTS: Congo red staining revealed the presence of Aß deposition in both the hippocampus and the cerebellum of the transgenic mice but not in the control mice. Real-time PCR showed a significantly lower expression of the 4 miRNAs in the hippocampus in the transgenic mice than in the control mice (P<0.05). The expression of miRNA-135a-5p, miRNA-298-5p, and miR-669f-3p in the cerebellum was significantly lower in the transgenic mice than in the control mice (P<0.05). The expression of miRNA-298-5p and miR-669f-3p in the hippocampus was significantly lower than that in the cerebellum of the transgenic mice (P<0.05). CONCLUSION: ß deposition also occurs in the cerebellum of APPswe/PSδE9 double transgenic mice, and its formation might be related to the down-regulation of miRNA-135a-5p, miRNA-298-5p, and miR-669f-3p.

[Expression of STAT3 and P-STAT3 in the brain of a transgenic mouse model of Alzheimer's disease].

OBJECTIVE: To detect the expression of signal transducer and activator of transcription 3 (STAT3) and P-STAT3 in the brain of the APPswe/PS δE9 double transgenic mouse model of Alzhaimer's disease (AD) and investigate their possible role in AD. METHODS: APPswe/PS δE9 double transgenic mice and control mice were examined for cerebral STAT3 and P-STAT3 expressions using immunothistochemistry. RESULTS: STAT3 and P-STAT3 were expressed in the different regions of mouse brain. In the transgenic mice and the control mice, the positivity rates of STAT3 were 93.75% and 87.50% in the cerebral cortex, 87.50% and 43.75% in the basal forebrain, 81.25% and 37.50% in the hippocampus, and 62.50% and 0.00% in the cerebellum, respectively, showing significant differences between the mice in the STAT3 expressions in the basal forebrain, hippocampus and cerebellum (P<0.05). The positivity rates of P-STAT3 in the two groups were 0.00% and 0.00% in the cerebral cortex, 68.75% and 0.00% in the basal forebrain, 62.50% and 12.50% in the hippocampus, and 43.75% and 0.00% in the cerebellum, respectively, showing also significant differences in the basal forebrain, hippocampus and cerebellum (P<0.05). The expression of STAT3 was positively correlated with that of P-STAT3 in transgenic AD mice (P<0.05). CONCLUSION: STAT3 and P-STAT3 are highly expressed in the basal forebrain, hippocampus and cerebellum in transgenic AD mice and may participate in the pathological process of AD.

[Real-time PCR for detecting differential expressions of microRNAs in the brain of a transgenic mouse model of Alzheimer's disease].

OBJECTIVE: To detect the expression of miRNA-135a-5p, miRNA-135a-2-3p, miRNA-298-5p, miRNA-466b-3p and miR-669f-3p in the brain tissue of the APPswe/PS δE9 double transgenic mouse model of Alzheimer's disease using real-time PCR. METHODS: Six-month-old APPswe/PS δE9 double transgenic mice and wild-type C57 mice of the same species were examined for the expressions of miRNA-135a-5p, miRNA-135a-2-3p, miRNA-298-5p, miRNA-466b-3p and miR-669f-3p in the brain tissue using real-time PCR. RESULTS: The relative expression levels of the 5 miRNAs in the transgenic versus the wild-type mice were 0.73∓0.27 vs 1.08∓0.58, 2.47∓6.15 vs 1.65∓0.67, 0.72∓0.14 vs 1.31∓0.73, 0.57∓0.34 vs 1.06∓0.35, and 0.63∓0.26 vs 1.02∓0.18, respectively, showing significance differences in the expressions of miRNA-135a-5p, miRNA-298-5p, miRNA-466b-3p, and miR-669f-3p between the two groups (P<0.05). CONCLUSIONS: miRNA-135a-5p, miRNA-298-5p, miRNA-466b-3p and miR-669f-3p are expressed differentially in APPswe/PS δE9 double transgenic mice, suggesting their important roles in the pathogenesis of Alzheimer disease.

[Expression profile of miRNAs in APP swe/PSΔE9 transgenic mice].

OBJECTIVE: To observe the changes of miRNA expression profiles in APPswe/PSδE9 transgenic mice and explore the possible roles of miRNA in the pathogenesis of Alzheimer's disease. METHODS: Using miRNA chip technique, we examined the miRNA expression in the brain tissue of 6-month-old APPswe/PSδE9 transgenic mice, with age-matched wild-type mice as the control group. RESULTS: Twelve miRNAs showed differential expressions by more than two folds in APPswe/PSδE9 transgenic mice, namely miRNA-135a, miRNA-135a-2*, miRNA-298, miRNA-466b-3p, miR-669-3p, miR-142-5p, miR-144, miR-466f-3p, miR-466g, miR-200a, miR-200b and miR-96. Five miRNAs were significantly down-regulated in the transgenic mice, including miRNA-135a, miRNA-135a-2*, miRNA-298, miRNA-466b-3p, and miR-669-3p. CONCLUSION: The 5 down- regulated miRNA may play important roles in the pathogenesis of AD in APPswe/PSδE9 transgenic mice.