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Early diagnosis is crucial for enhancing the survival rate of renal cell cancer patients, and exosomes present potential advantages in this area. Their small size, high mobility, and lipid bilayer structure enable exosomes to cross biological membranes easily, protecting the bioactive cargo within from degradation. Exosomes significantly influence the invasion and metastasis of RCC, and they also contribute to tumor drug resistance and immune evasion. [ABSTRACT FROM AUTHOR]

Alzheimer disease (AD) is characterized by the accumulation of amyloid plaques, which are predominantly composed of amyloid-β peptide (1). Two principal physiological pathways either prevent or promote amyloid-β generation from its precursor, β-amyloid precursor protein (APP), in a competitive manner (1). Although APP processing has been studied in great detail, unknown proteolytic events seem to hinder stoichiometric analyses of APP metabolism in vivo (2). Here we describe a new physiological APP processing pathway, which generates proteolytic fragments capable of inhibiting neuronal activity within the hippocampus. We identify higher molecular mass carboxy-terminal fragments (CTFs) of APP, termed CTF-η, in addition to the long-known CTF-α and CTF-β fragments generated by the α- and β-secretases ADAM10 (a disintegrin and metalloproteinase 10) and BACE1 (β-site APP cleaving enzyme 1), respectively. CTF-η generation is mediated in part by membrane-bound matrix metalloproteinases such as MT5-MMP, referred to as η-secretase activity. η-Secretase cleavage occurs primarily at amino acids 504-505 of [APP.sub.695], releasing a truncated ectodomain. After shedding of this ectodomain, CTF-η is further processed by ADAM10 and BACE1 to release long and short Aη peptides (termed Aη-α and Aη-β). CTFs produced by η-secretase are enriched in dystrophic neurites in an AD mouse model and in human AD brains. Genetic and pharmacological inhibition of BACE1 activity results in robust accumulation of CTF-η and Aη-α. In mice treated with a potent BACE1 inhibitor, hippocampal long-term potentiation was reduced. Notably, when recombinant or synthetic Aη-α was applied on hippocampal slices exvivo, long-term potentiation was lowered. Furthermore, in vivo single-cell two-photon calcium imaging showed that hippocampal neuronal activity was attenuated by Aη-α. These findings not only demonstrate a major functionally relevant APP processing pathway, but may also indicate potential translational relevance for therapeutic strategies targeting APP processing., To identify new proteolytic pathways of APP, we searched for CTFs other than those giving rise to P3 fragment (CTF-α) or amyloid-β (CTF-β) (3-5). A new CTF with an approximate [...]

Autism spectrum disorder (ASD) is a neurodevelopmental condition causing a range of social and communication impairments. Although the role of multiple genes and environmental factors has been reported, the effects of the interplay between genes and environment on the onset and progression of the disease remains elusive. We housed wild‐type (Tsc2+/+) and tuberous sclerosis 2 deficient (Tsc2+/−) Eker rats (ASD model) in individually ventilated cages or enriched conditions and conducted a series of behavioural tests followed by the histochemical analysis of dendritic spines and plasticity in three age groups (days 45, 90 and 365). The elevated plus‐maze test revealed a reduction of anxiety by enrichment, whereas the mobility of young and adult Eker rats in the open field was lower compared to the wild type. In the social interaction test, an enriched environment reduced social contact in the youngest group and increased anogenital exploration in 90‐ and 365‐day‐old rats. Self‐grooming was increased by environmental enrichment in young and adult rats and decreased in aged Eker rats. Dendritic spine counts revealed an increased spine density in the cingulate gyrus in adult Ekers irrespective of housing conditions, whereas spine density in hippocampal pyramidal neurons was comparable across all genotypes and groups. Morphometric analysis of dendritic spines revealed age‐related changes in spine morphology and density, which were responsive to animal genotype and environment. Taken together, our findings suggest that under TSC2 haploinsufficiency and mTORC1 hyperactivity, the expression of behavioural signs and neuroplasticity in Eker rats can be differentially influenced by the developmental stage and environment. [ABSTRACT FROM AUTHOR]