Journal of experimental neurology最新文献

Bardet-Biedl Syndrome (BBS) is a rare autosomal recessive disorder characterized by retinal degeneration leading to blindness. This study investigates the therapeutic efficacy of N-Acetylcysteine (NAC), an oxygen free radical scavenger, in ameliorating retinal degeneration associated with BBS using a murine model of BBS10. BBS is caused by mutations in BBS genes, the protein products of which are involved in ciliary function; mutant or absent BBS10 protein disrupts the assembly of the BBSome protein complex, disturbing ciliary trafficking and leading to photoreceptor cell dysfunction and death. Photoreceptor function can be assessed using the electroretinogram (ERG), and anatomy can be assessed using optical coherence tomography (OCT) and histology to demonstrate progressive degeneration over time. This study utilizes Bbs10 ^-/- mice to assess the effect of NAC supplementation on retinal degeneration. Results reveal that NAC supplementation ameliorates the progressive degeneration of the retinal outer nuclear layer (ONL) on OCT and mitigates the loss-of-b-wave ERG phenotype observed in Bbs10 ^-/- mice. The ERG b-wave is generated by retinal bipolar cells after synapsing with photoreceptors which have been hyperpolarized by light exposure. Reducing the loss-of-b-wave phenotype may indicate improved synaptic function. Synaptic staining demonstrates a correlation between the absence of an electropositive b-wave and mislocalized presynaptic terminals, highlighting the significance of synaptic integrity for retinal function. These findings suggest NAC as a promising therapeutic intervention for managing BBS10-related retinal degeneration.

Understanding the development of the auditory system is crucial for uncovering the molecular origins of hearing and its related disorders. During this development, spiral ganglion neurons extend peripheral fibers to cochlear hair cells and central projections to the cochlear nuclei, setting up a tonotopic map that connects the ear to the brainstem, enabling frequency-specific sound perception. This sensory information is then integrated bilaterally through a relay involving the superior olivary complex, lateral lemniscus, inferior colliculus, medial geniculate body, and the auditory cortex. While anatomical connectivity has been well-documented, recent advancements have revealed gene regulatory networks that coordinate the specification, differentiation, and connectivity of auditory neurons. In this review, we examine the molecular cascades guiding auditory system development, emphasizing transcriptional hierarchies and lineage determinants. Insights into these mechanisms enhance our understanding of auditory circuit formation and provide a critical foundation for therapeutic strategies aimed at addressing congenital and acquired hearing loss.

Thirty percent of ischemic stroke patients develop vascular cognitive impairment and dementia (VCID) within 1 year of stroke onset. The expression of C-C motif chemokine receptor 3 (CCR3) is associated with endothelial dysfunction and memory impairment. CCR3 has been reported to increase after experimental stroke and in human stroke patients. Using an in vivo model of stroke, our study aims to link CCR3 expression with endothelial dysfunction in this rodent stroke model.

Methods: 5-hour transient Middle Cerebral Artery Occlusion (5t-MCAO) or sham surgery was performed on rats and tissue collected at 3- and 30-days post-stroke. We measured the change in expression of CCR3 and its ligands in the venous blood before and after occlusion in the rat model.Immunohistochemistry was performed on consecutive coronal brain sections using Prussian blue to visualize microbleeds and DAB to visualize CCR3. Images were quantified using HALO.

Results: Using linear regression, we found that increased expression of CCR3 and its ligands after stroke were positively correlated with infarct volume. CCR3 expression was significantly increased in the ipsilateral hemisphere at 30 days post 5t-MCAO. Prussian blue staining was significantly increased in ipsilateral sections at 30 days post-stroke. Immunostaining for CCR3 was primarily detected in endothelium in areas of Prussian blue staining.

Conclusions: Our results demonstrate that CCR3 expression is associated with the presence of microbleeds at 30 days but not 3 days post-stroke in the ipsilateral hemisphere, and further supports the link between CCR3 and the endothelial dysfunction that is associated with VCID. CCR3 and its inflammatory pathway is a potential target for reducing endothelial dysfunction after ischemic stroke that may lead to VCID.

Alzheimer's Disease (AD) and Alzheimer's Disease-Related Dementia (ADRD) are the primary causes of dementia that has a devastating effect on the quality of life and is a tremendous economic burden on the healthcare system. The accumulation of extracellular beta-amyloid (Aβ) plaques and intracellular hyperphosphorylated tau-containing neurofibrillary tangles (NFTs) in the brain are the hallmarks of AD. They are also thought to be the underlying cause of inflammation, neurodegeneration, brain atrophy, and cognitive impairments that accompany AD. The discovery of APP, PS1, and PS2 mutations that increase Aβ production in families with early onset familial AD led to the development of numerous transgenic rodent models of AD. These models have provided new insight into the role of Aβ in AD; however, they do not fully replicate AD pathology in patients. Familial AD patients with mutations that elevate the production of Aβ represent only a small fraction of dementia patients. In contrast, those with late-onset sporadic AD constitute the majority of cases. This observation, along with the failure of previous clinical trials targeting Aβ or Tau and the modest success of recent trials using Aβ monoclonal antibodies, has led to a reappraisal of the view that Aβ accumulation is the sole factor in the pathogenesis of AD. More recent studies have established that cerebral vascular dysfunction is one of the earliest changes seen in AD, and 67% of the candidate genes linked to AD are expressed in the cerebral vasculature. Thus, there is an increasing appreciation of the vascular contribution to AD, and the National Institute on Aging (NIA) and the Alzheimer's Disease Foundation recently prioritized it as a focused research area. This review summarizes the strengths and limitations of the most commonly used transgenic AD animal models and current views about the contribution of Aβ accumulation versus cerebrovascular dysfunction in the pathogenesis of AD.

Amyotrophic Lateral Sclerosis (ALS) is a devastating and progressive neurodegenerative disease with a complex, multifactorial pathophysiology, culminating in death of motor neurons. We introduce a new mechanism of ALS pathogenesis via study of a novel drug-like small molecule series that targets a subset of protein disulfide isomerase (PDI) within a previously largely unappreciated transient and energy-dependent multi-protein complex enriched for proteins of the ALS interactome. This drug, found by a novel phenotypic screen, has activity in cellular models for both familial and sporadic ALS, as well as in transgenic worms, flies, and mice bearing a diversity of human genes with ALS-associated mutations. The hit compound was initially identified as a modulator of human immunodeficiency virus (HIV) capsid assembly in cell-free protein synthesis and assembly (CFPSA) systems, with demonstrated antiviral activity against infectious HIV in cell culture. Its advancement for ALS-therapeutics, subsequent separation of activity against HIV and ALS into separate chemical subseries through structure-activity-relationship (SAR) optimization, and identification of the drug target by affinity chromatography as shown here, may provide insights into the molecular mechanisms governing pathophysiology of disordered homeostasis relevant to ALS.