SNAP25 mutation disrupts metabolic homeostasis, steroid hormone production and central neurobehavior

Motor skill learning modulates striatal extracellular vesicles' content in a mouse model of Huntington's disease

Huntington's disease (HD) is a neurological disorder caused by a CAG expansion in the Huntingtin gene (HTT). HD pathology mostly affects striatal medium-sized spiny neurons and results in an altered cortico-striatal function. Recent studies report that motor skill learning, and cortico-striatal stimulation attenuate the neuropathology in HD, resulting in an amelioration of some motor and cognitive functions. During physical training, extracellular vesicles (EVs) are released in many tissues, including the brain, as a potential means for inter-tissue communication. To investigate how motor skill learning, involving acute physical training, modulates EVs crosstalk between cells in the striatum, we trained wild-type (WT) and R6/1 mice, the latter with motor and cognitive deficits, on the accelerating rotarod test, and we isolated their striatal EVs. EVs from R6/1 mice presented alterations in the small exosome population when compared to WT. Proteomic analyses revealed that striatal R6/1 EVs recapitulated signaling and energy deficiencies present in HD. Motor skill learning in R6/1 mice restored the amount of EVs and their protein content in comparison to naïve R6/1 mice. Furthermore, motor skill learning modulated crucial pathways in metabolism and neurodegeneration. All these data provide new insights into the pathogenesis of HD and put striatal EVs in the spotlight to understand the signaling and metabolic alterations in neurodegenerative diseases. Moreover, our results suggest that motor learning is a crucial modulator of cell-to-cell communication in the striatum.

Shen Qi Wan Ameliorates Learning and Memory Impairment Induced by STZ in AD Rats through PI3K/AKT Pathway

Alzheimer’s disease is the most common form of neurodegenerative disease, and increasing evidence shows that insulin signaling has crucial roles in AD initiation and progression. In this study, we explored the effect and underlying mechanism of SQW, a representative formula for tonifying the kidney and promoting yang, on improving the cognitive function in a streptozotocin-induced model of AD rats. We investigated memory impairment in the AD rats by using the Morris water test. HE and Nissl staining were employed to observe the histomorphological changes in the hippocampal. Expression levels of NeuN and proteins related to Tau and apoptosis were measured using immunohistochemistry and Western blotting, respectively. Additionally, we performed RNA sequencing, and the selected hub genes were then validated by qRT-PCR. Furthermore, the protein expression levels of PI3K/AKT pathway-related proteins were detected by Western blot. We found that SQW treatment significantly alleviated learning and memory impairment, pathological damage, and apoptosis in rats, as evidenced by an increased level of NeuN and Bcl-2, and decreased phosphorylation of Tau, Bax, and Caspase-3 protein expression. SQW treatment reversed the expression of insulin resistance-related genes (Nr4a1, Lpar1, Bdnf, Atf2, and Ppp2r2b) and reduced the inhibition of the PI3K/AKT pathway. Our results demonstrate that SQW could contribute to neuroprotection against learning and memory impairment in rats induced by STZ through activation of the PI3K/AKT pathway.