Astrocyte transcriptomic changes along the spatiotemporal progression of Alzheimer's disease.

Astrocytes are crucial to brain homeostasis, yet their changes along the spatiotemporal progression of Alzheimer's disease (AD) neuropathology remain unexplored. Here we performed single-nucleus RNA sequencing of 628,943 astrocytes from five brain regions representing the stereotypical progression of AD pathology across 32 donors spanning the entire normal aging to severe AD continuum. We mapped out several unique astrocyte subclusters that exhibited varying responses to neuropathology across the AD-vulnerable neural network (spatial axis) or AD pathology stage (temporal axis).

Landscape of brain myeloid cell transcriptome along the spatiotemporal progression of Alzheimer's disease reveals distinct sequential responses to Aβ and tau.

Human microglia are critically involved in Alzheimer's disease (AD) progression, as shown by genetic and molecular studies. However, their role in tau pathology progression in human brain has not been well described. Here, we characterized 32 human donors along progression of AD pathology, both in time-from early to late pathology-and in space-from entorhinal cortex (EC), inferior temporal gyrus (ITG), prefrontal cortex (PFC) to visual cortex (V2 and V1)-with biochemistry, immunohistochemistry, and single nuclei-RNA-sequencing, profiling a total of 337,512 brain myeloid cells, including microglia.

Distinct transcriptomic responses to Aβ plaques, neurofibrillary tangles, and APOE in Alzheimer's disease.

Introduction: Omics studies have revealed that various brain cell types undergo profound molecular changes in Alzheimer's disease (AD) but the spatial relationships with plaques and tangles and APOE-linked differences remain unclear.

Methods: We performed laser capture microdissection of amyloid beta (Aβ) plaques, the 50 μm halo around them, tangles with the 50 μm halo around them, and areas distant (> 50 μm) from plaques and tangles in the temporal cortex of AD and control donors, followed by RNA-sequencing.

Results: Aβ plaques exhibited upregulated microglial (neuroinflammation/phagocytosis) and downregulated neuronal (neurotransmission/energy metabolism) genes, whereas tangles had mostly downregulated neuronal genes.

Endothelial Cells Are Heterogeneous in Different Brain Regions and Are Dramatically Altered in Alzheimer's Disease.

Vascular endothelial cells play an important role in maintaining brain health, but their contribution to Alzheimer's disease (AD) is obscured by limited understanding of the cellular heterogeneity in normal aged brain and in disease. To address this, we performed single nucleus RNAseq on tissue from 32 human AD and non-AD donors (19 female, 13 male) each with five cortical regions: entorhinal cortex, inferior temporal gyrus, prefrontal cortex, visual association cortex, and primary visual cortex. Analysis of 51,586 endothelial cells revealed unique gene expression patterns across the five regions in non-AD donors.

Distinct Transcriptomic Responses to Aβ plaques, Neurofibrillary Tangles, and in Alzheimer's Disease.

Introduction: Omics studies have revealed that various brain cell types undergo profound molecular changes in Alzheimer's disease (AD) but the spatial relationships with plaques and tangles and -linked differences remain unclear.

Methods: We performed laser capture microdissection of Aβ plaques, the 50μm halo around them, tangles with the 50μm halo around them, and areas distant (>50μm) from plaques and tangles in the temporal cortex of AD and control donors, followed by RNA-sequencing.

Results: Aβ plaques exhibited upregulated microglial (neuroinflammation/phagocytosis) and downregulated neuronal (neurotransmission/energy metabolism) genes, whereas tangles had mostly downregulated neuronal genes.

Endothelial Cells are Heterogeneous in Different Brain Regions and are Dramatically Altered in Alzheimer's Disease.

Unlabelled: Vascular endothelial cells play an important role in maintaining brain health, but their contribution to Alzheimer's disease (AD) is obscured by limited understanding of the cellular heterogeneity in normal aged brain and in disease. To address this, we performed single nucleus RNAseq on tissue from 32 AD and non-AD donors each with five cortical regions: entorhinal cortex, inferior temporal gyrus, prefrontal cortex, visual association cortex and primary visual cortex. Analysis of 51,586 endothelial cells revealed unique gene expression patterns across the five regions in non-AD donors.

Quantitative comparison of phosphodiesterase mRNA distribution in human brain and peripheral tissues.

Cyclic nucleotide-specific phosphodiesterases (PDEs) play a critical role in signal transduction by regulating the level of adenosine 3',5'-cyclic monophosphate (cAMP) and guanosine 3',5'-cyclic monophosphate (cGMP) in cells. The gene expression pattern of a PDE provides important information regarding its role in physiological and pathological processes. In this study, we have established the mRNA expression profile all PDE isoenzymes (PDE1A/B/C, 2A, 3A/B, 4A/B/C/D, 5A, 6A/B/C, 7A/B, 8A/B, 9A, 10A, 11A) in a human cDNA collection consisting of 10 brain regions (parietal, frontal, temporal cortex, hippocampus, striatum, thalamus, hypothalamus, substantia nigra, nucleus accumbens, cerebellum), spinal cord, dorsal root ganglia and 12 peripheral tissues (skeletal muscle, heart, thyroid, adrenal gland, pancreas, bladder, kidney, liver, lung, small intestine, spleen, and stomach).

Development of homogeneous 384-well high-throughput screening assays for Abeta1-40 and Abeta1-42 using AlphaScreen technology.

Amyloid beta (Abeta) peptides are the major constituent of amyloid plaques, one of the hallmark pathologies of Alzheimer's disease. Accurate and precise quantitation of these peptides in biological fluids is a critical component of Alzheimer's disease research. The current most established assay for analysis of Abeta peptides in preclinical research is enzyme-linked immunosorbent assay (ELISA), which, although sensitive and of proven utility, is a multistep, labor-intensive assay that is difficult to automate completely.

The antianginal agent trimetazidine does not exert its functional benefit via inhibition of mitochondrial long-chain 3-ketoacyl coenzyme A thiolase.

Trimetazidine acts as an effective antianginal clinical agent by modulating cardiac energy metabolism. Recent published data support the hypothesis that trimetazidine selectively inhibits long-chain 3-ketoacyl CoA thiolase (LC 3-KAT), thereby reducing fatty acid oxidation resulting in clinical benefit. The aim of this study was to assess whether trimetazidine and ranolazine, which may also act as a metabolic modulator, are specific inhibitors of LC 3-KAT.

Epitope-specific antibody-induced cleavage of angiotensin-converting enzyme from the cell surface.

Angiotensin I-converting enzyme (ACE; CD143, EC 3.4.15.

Mitogen-activated protein kinase kinase 7 is activated during low potassium-induced apoptosis in rat cerebellar granule neurons.

A stress-activated protein kinase pathway comprising mitogen-activated protein kinase kinases (MKKs), c-Jun N-terminal kinase (JNK) and the transcription factor c-Jun is implicated in neuronal apoptosis. Using an immune-complex kinase assay, we measured the activation of MKK4 and MKK7 in low potassium (LK)-induced apoptosis of rat cerebellar granule neurons (CGN). MKK7, but not MKK4, was activated within the first 4-6 h in four independent sets of 14-h CGN apoptosis time-courses.