Discrepancy of synaptic and microtubular protein phosphorylation in the hippocampus of APP/PS1 and MAPT×P301S transgenic mice at the early stage of Alzheimer's disease

The effect of tau K677 lactylation on ferritinophagy and ferroptosis in Alzheimer's disease

Alzheimer's disease (AD) is characterized by cognitive decline and the accumulation of amyloid-beta plaques and hyperphosphorylated tau protein. The role of tau lactylation at the K677 site in AD progression is not well understood. This study explores how tau K677 lactylation affects ferritinophagy, ferroptosis, and their functions in an AD mouse model. Results show that mutating the K677 site to R reduces tau lactylation and inhibits ferroptosis by regulating iron metabolism factors like NCOA4 and FTH1.Tau-mutant mice showed improved memory and learning skills compared to wild-type mice. The mutation also reduced neuronal damage and was associated with decreased tau lactylation at the K677 site, regardless of phosphorylated tau levels. Gene set enrichment analysis showed that lactylation at this site was linked to the MAPK pathway, which was important for ferritinophagy in AD mice. In summary, our research indicates that the K677 mutation in tau protein may protect against AD by influencing ferritinophagy and ferroptosis through MAPK signaling pathways. Understanding these modifications in tau could lead to new treatments for AD.

Implementation of the neuro-glia-vascular unit through co-culture of adult neural stem cells and vascular cells and transcriptomic analysis of diverse Aβ assembly types

BACKGROUND

The blood-brain barrier (BBB) is a specialized layer between blood vessels and tissue in the brain, which is comprised of a neuro-glia-vascular (NGV) unit, thus play a vital role in various brain diseases.

NEW METHOD

We developed the in vitro NGV units by co-culturing brain microvascular endothelial cells (BMECs; bEnd.3) and primary neural stem cells extracted from subventricular zone of adult mice. This approach was designed to mimic the RNA profile conditions found in the microvessels of a mouse brain and confirmed through various comparative transcriptome analyses.

RESULTS

Optimal NGV unit development was achieved by adjusting cell density-dependent co-culture ratios. Specifically, the morphogenic development and neuronal association of astrocyte endfeet were well observed in the contact region with BMECs in the NGV unit. Through transcriptome analysis, we compared co-cultured bEnd.3/NSCs with monocultured bEnd.3 or NSCs and additionally compared them with previously reported mouse brain vascular tissue to show that this NGV unit model is a suitable in vitro model for neurological disease such as Alzheimer's disease (AD).

COMPARISON WITH EXISTING METHOD(S)

This in vitro NGV unit was formed from neural stem cells and vascular cells in the brain of adult mice, not embryos. It is very useful for studying brain disease mechanisms by identifying proteins and genes associated with diseases progress.

CONCLUSIONS

We suggest that this simple in vitro NGV model is appropriate to investigate the relationship between BBB changes and pathological factors in the fields of neurovascular biology and cerebrovascular diseases including AD.

An in silico approach to identify potential downstream targets of miR-153 involved in Alzheimer's disease

Background: In recent years, microRNAs (miRNAs) have emerged as key players in the pathophysiology of multiple diseases including Alzheimer's disease (AD). Messenger RNA (mRNA) targeting for regulation of gene expression by miRNAs has been implicated in the annotation of disease pathophysiology as well as in the explication of their starring role in contemporary therapeutic interventions. One such miRNA is miR-153 which mediates the survival of cortical neurons and inhibits plaque formation. However, the core mRNA targets of miR-153 have not been fully illustrated. Objective: The present study aimed to elucidate the potential involvement of miR-153 in AD pathogenesis and to reveal its downstream targets. Methods: miRanda was used to identify AD-associated targets of miR-153. TargetScan, PicTar, miRmap, and miRDB were further used to validate these targets. STRING 12 was employed to assess the protein-protein interaction network while Gene ontology (GO) analysis was carried out to identify the molecular functions exhibited by these gene targets. Results: In silico analysis using miRanda predicted five important AD-related targets of miR-153, including APP, SORL1, PICALM, USF1, and PSEN1. All five target genes are negatively regulated by miR-153 and are substantially involved in AD pathogenesis. A protein interaction network using STRING 12 uncovered 30 potential interacting partners for SORL1, PICALM, and USF1. GO analysis revealed that miR-153 target genes play a critical role in neuronal survival, differentiation, exon guidance, amyloid precursor protein processing, and synapse formation. Conclusion: These findings unravel the potential role of miR-153 in the pathogenesis of AD and provide the basis for forthcoming experimental studies.

Amyloid-β: A potential mediator of aging-related vascular pathologies

Aging is one of the most promising risk factors for vascular diseases, however, the precise mechanisms mediating aging-related pathologies are not fully understood. Amyloid beta (Aβ), a peptide produced by the proteolytic processing of amyloid precursor protein (APP), is known as a key mediator of brain damage involved in the pathogenesis of Alzheimer's disease (AD). Recently, it was found that the accumulation of Aβ in the vascular wall is linked to a range of aging-related vascular pathologies, indicating a potential role of Aβ in the pathogenesis of aging-associated vascular diseases. In the present review, we have updated the molecular regulation of Aβ in vascular cells and tissues, summarized the relevance of the Aβ deposition with vascular aging and diseases, and the role of Aβ dysregulation in aging-associated vascular pathologies, including the impaired vascular response, endothelial dysfunction, oxidative stress, and inflammation. This review will provide advanced information in understanding aging-related vascular pathologies and a new avenue to explore therapeutic targets.