ABSTRACT: Dubosiella newyorkensis improves Alzheimer's disease in APP/PS1 mice by modulating gut microbiota composition and regulating glycerolphospholipid metabolism
Project description:The Ketogenic Diet (KD) improves memory and longevity in aged C57BL/6 mice. We tested 7 months KD vs. control diet (CD) in the mouse Alzheimer's Disease (AD) model APP/PS1. KD significantly rescued Long-Term-Potentiation (LTP) to wild-type levels, not by changing Amyloid-β (Aβ) levels. KD's 'main actor' is thought to be Beta-Hydroxy-butyrate (BHB) whose levels rose significantly in KD vs. CD mice, and BHB itself significantly rescued LTP in APP/PS1 hippocampi. KD's 6 most significant pathways induced in brains by RNAseq all related to Synaptic Plasticity. KD induced significant increases in synaptic plasticity enzymes p-ERK and p-CREB in both sexes, and of brain-derived neurotrophic factor (BDNF) in APP/PS1 females. We suggest KD rescues LTP through BHB's enhancement of synaptic plasticity. LTP falls in Mild-Cognitive Impairment (MCI) of human AD. KD and BHB, because they are an approved diet and supplement respectively, may be most therapeutically and translationally relevant to the MCI phase of Alzheimer's Disease.
Project description:Our study aimed to investigate the biological impact of forebrain neuron-specific farnesyltransferase knockout in a transgenic APP/PS1 Alzheimer's disease model.
Project description:Our study aimed to dissect differentially expressed circRNAs in the hippocampus of wild type and APP/PS1 mice and demonstrated the important role of circRNA in Alzheimer's disease.
Project description:The etiology of Alzheimer's disease (AD) has been intensively studied. However, little is known about the molecular alterations in early-stage and late-stage AD. Hence, we performed RNA sequencing and assessed differentially expressed genes (DEGs) in the hippocampus of 18-month and 7-month-old APP/PS1 mice. Moreover, the DEGs induced by treatment with nicotine, the nicotinic acetylcholine receptor agonist that is known to improve cognition in AD, were also analyzed in old and young APP/PS1 mice. When comparing old APP/PS1 mice with their younger littermates, we found an upregulation in genes associated with calcium overload, immune response, cancer, and synaptic function; the transcripts of 14 calcium ion channel subtypes were significantly increased in aged mice. In contrast, the downregulated genes in aged mice were associated with ribosomal components, mitochondrial respiratory chain complex, and metabolism. Through comparison with DEGs in normal aging from previous reports, we found that changes in calcium channel genes remained one of the prominent features in aged APP/PS1 mice. Nicotine treatment also induced changes in gene expression. Indeed, nicotine augmented glycerolipid metabolism, but inhibited PI3K and MAPK signaling in young mice. In contrast, nicotine affected genes associated with cell senescence and death in old mice. Our study suggests a potential network connection between calcium overload and cellular signaling, in which additional nicotinic activation might not be beneficial in late-stage AD
Project description:We performed next-generation RNA sequencing (RNA-seq) using brain tissue from 23 months old non-transgenic (NTG), non-treated and CP2 (mitochondrial complex I inhibitor)-treated APP/PS1 (mouse model of Alzheimer`s disease). By comparing transcriptomic data of NTG and vehicle-treated APP/PS1 mice, we found processes affected by the disease in APP/PS1 such as impaired ATP metabolism, ion transport, nervous system development, synaptic transmission, and inflammation. CP2-treatment in APP/PS1 positively affected genes related to immune system, axonogenesis, dendritic spine morphology, synaptic function, among the others. These data demonstrate that pathways improved by CP2 treatment in APP/PS1 mice comprise major pathways essential for therapeutic efficacy in Alzheimer`s disease.
Project description:Aquaporin-4 (AQP4) is highly polarized to perivascular astrocytic endfeet. Loss of AQP4 polarization is associated with many diseases. In Alzheimer's disease (AD), it is found that AQP4 loos its normal location and thus reduce the clearance of amyloid-β plaques and Tau protein. Clinical and experimental studies show that moxibustion can improve the learning and memory abilities of AD. In order to explore whether moxibustion can affect the polarization of AQP4 around blood brain barrier (BBB), we used spatial transcriptomics (ST) to analyze the expression and polarization of Aqp4 in wild type mice, APP/PS1 mice and APP/PS1 mice intervened by moxibustion. The results showed that moxibustion improved the loss of abnormal polarization of AQP4 in APP/PS1 mice, especially in the hypothalamic BBB. Besides, there are other 31 genes with Aqp4 as the core have the similar depolarization in APP/PS1 mice, most of which are also membrane proteins. The majority of them have been reversed by moxibustion. At the same time, we employed the cerebrospinal fluid circulation gene set, which was found being on a higher level in the group of APP/PS1 mice with moxibustion treatment. Finally, in order to further explore its mechanism, we analyzed the mitochondrial respiratory chain complex enzymes closely related to energy metabolism, and found that moxibustion can significantly increase the expression of mitochondrial respiratory chain enzymes such as Cox6a2 in the hypothalamus, which could provide energy for mRNA transport. Our research shows that increasing the polarization of hypothalamic Aqp4 through mitochondrial energy supply may be an important target for moxibustion to improve APP/PS1 mice’s cognitive impairment.
Project description:To explore the miRNAs associated with the memory deficits in Alzheimer's disease, we detected the miRNA profiles in the hippocampus of 6-month-old male APPswe/PS1dE9 (APP/PS1) mice and age-matched wild type C57BL/6 mice.
Project description:In a series of slice electrophysiology experiments, we demonstrated that female APPSwe-Psen1dE9 Alzheimer's disease model mice show greater impairments in hippocampal synaptic plasticity than male mice of the same age and genotype. Female APP/PS1 mice also showed greater impairments in behavioural associative memory, higher amyloid plaque burden and increased microglial activation in the hippocampus than males at age 4-5 months. We thus profiled hippocampal mRNA from these mice to investigate the underlying molecular mechanisms. Compared to wild-type mice of the same sex, we found that female APP/PS1 mice showed a greater upregulation of microglial and inflammatory genes than males. Moreover, downregulation of genes associated with memory and plasticity was observed uniquely in female APP/PS1 mice. These data provide insight into the potential mechanisms of the greater prevalence and faster progression of AD in females.
Project description:Aβ is a peptide of 39-42 amino acid residues that derived from putative intramembranous processing of amyloid precursor protein (APP) at the proposed active site of the γ-secretase/PS1 aspartyl. Aβ has been shown to aggregate and accumulate abnormally in the brain of AD (Alzheimer's disease), and extracellular amyloid plaques of Aβ peptides aggregation can trigger a cascade of pathologic events leading to nerve fiber entanglement and neuronal apoptosis protease. We used microarrays to investigate the effects of HPYD on the gene expression of APP/PS1 transgenic mice, the brain tissues of control group, model group and HPYD group mice.