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Mihira, N.

Publications and source records attributed to Mihira, N..

3 recordsLinked to original sources

CXCL10 drives female-specific tau pathology progression and defines sex-dependent vulnerability in tauopathy model mice

Neuroinflammation is a central driver of tauopathy, yet the precise chemokines that orchestrate the inflammatory microenvironment remain elusive. Here, we report C-X-C motif chemokine ligand 10 (CXCL10) is markedly upregulated in the brains of tauopathy model mice, where it co-localizes with prominent tau pathology. Notably, genetic ablation of Cxcl10 in these mice significantly attenuates tau burden and extends the survival period, specifically in a female-dependent manner. Mechanistically, although Cxcl10 deficiency reduces the number of brain T cells in both sexes, this reduction does not correlate with the female-specific rescue of the phenotype. Furthermore, Cxcl10 deficiency did not alter glial cell activation or motor function, suggesting a sex-specific mechanism. We show CXCL10 is primarily produced by pathological glia, fostering a localized inflammatory microenvironment. Our findings identify CXCL10 as a key mediator of tau pathology and reveal a sex-dimorphic regulatory axis that operates independently of T cell and glial activation paradigms.

neuroscience↗

New App knock-in mice that accumulate wild-type human Aβ as rapidly as AppNL-G-F mice exhibit intensive cored plaque pathology and neuroinflammation.

We previously developed single App knock-in mouse models of Alzheimers disease (AD), harboring the Swedish and Beyreuther/Iberian mutations with or without the Arctic mutation (AppNL-G-F and AppNL-F mice). These models showed amyloid {beta} peptide (A{beta}) pathology, neuroinflammation and cognitive impairment in an age-dependent manner. The former line exhibits extensive pathology as early as 6 months but is unsuitable for investigating A{beta} metabolism and clearance because the Arctic mutation renders A{beta} resistant to proteolytic degradation and prone to aggregation. In particular, it is inapplicable to preclinical immunotherapy studies due to its discrete affinity for anti-A{beta} antibodies. The weakness of the latter model is that it may take as long as 18 months for the pathology to become prominent. We have thus generated a new model that exhibits early deposition of wild-type human A{beta} by crossbreeding the AppNL-F line with the Psen1P117L/WT line. We show that the effects of the pathogenic mutations in the App and Psen1 genes are additive or synergistic. This new mouse model showed more cored plaque pathology and neuroinflammation than AppNL-G-F mice and will help accelerate the development of disease-modifying therapies to treat preclinical AD.

neuroscience↗

A non-human primate model of familial Alzheimer's disease

Alzheimers disease (AD) is a major cause of dementia, with the number of patients with this condition anticipated to exceed 50 million worldwide in the near future. Despite extensive research efforts, no effective measures are available to facilitate the prevention or treatment of AD, which is due in part to a lack of animal models able to closely replicate a human-like disease state. Here, we describe the generation of three mutant marmoset individuals in which exon 9 of PSEN1 gene product has been deleted (PSEN1-{Delta}E9). Such {Delta}E9 mutations have been reported to cause early on-set familial AD (references1-5). We used Transcription Activator-Like Effector Nuclease (TALEN) to destroy the 3 splice site of exon 9 in the marmoset PSEN1 gene. To this end, TALEN exhibits high genome-editing efficacy, generates few off-target effects, and produces minimal mosaicism. Indeed, whole genome sequencing and other analyses illustrated an absence of off-target effects and an apparent absence of mosaicism. Fibroblasts obtained from newborn marmosets exhibited uncleaved full-length presenilin 1 protein (PS1) caused by the perturbation of PS1 endoproteolysis as well as an increased ratio of A{beta}42/A{beta}40 production, a signature of familial AD pathogenesis. To our knowledge, this is the first non-human primate model of familial AD. We intend to make our marmoset model available to the research community to facilitate the global fight against AD.

neuroscience↗