Synaptic plasticity in hippocampal CA1 neurons and learning behavior in acute kidney injury, and estradiol replacement in ovariectomized rats

Abstract

Background: Neurological complications may occur in patients with acute or chronic renal failure; however, in cases of acute renal failure, the signs and symptoms are usually more pronounced, and progressed rapidly. Oxidative stress and nitric oxide in the hippocampus, following kidney injury may be involved in cognitive impairment in patients with uremia. Although many women continue taking hormone therapy for menopausal symptom relief, but there are also some controversies about the efficacy of exogenous sex hormones, especially estrogen therapy alone, in postmenopausal women with kidney injury. Herein, to the best of our knowledge for the first time, spatial memory and synaptic plasticity at the CA1 synapse of a uremic ovariectomized rat model of menopause was characterized by estradiol replacement alone. Results: While estradiol replacement in ovariectomized rats without uremia, promotes synaptic plasticity, it has an impairing effect on spatial memory through hippocampal oxidative stress under uremic conditions, with no change on synaptic plasticity. It seems that exogenous estradiol potentiated the deleterious effect of acute kidney injury (AKI) with increasing hippocampal oxidative stress. Conclusions: Although, estrogen may have some positive effects on cognitive function in healthy subjects, but its efficacy in menopause subjects under uremic states such as renal transplantation, needs to be further investigated in terms of dosage and duration.

Environmental enrichment initiated in adolescence restores the reduced expression of synaptophysin and GFAP in the hippocampus of chronically stressed rats in a sex‐specific manner

“…The sex‐specific effects of chronic stress on synaptic markers found in the present study and also reported by others, could be attributed to sex steroids (i.e., testosterone and estradiol), given that they control hippocampal synaptic plasticity and modulate adaptive structural and functional plasticity (Brandt et al., 2020, Wei et al., 2014). Specifically, estrogens (i.e., estradiol) play a significant role during synaptic reorganization (Carvalho‐Netto et al., 2011; Sharifi et al., 2019). For example, they may mediate increases in the densities of dendritic spines and synapses on hippocampal CA1 pyramidal cells in female rats (Wei et al., 2014), as well as they exert antidepressant effects and offer protection against cognitive deficits aggravated by chronic stress (McEwen & Milner, 2017; Qu et al., 2020; Xu et al., 2021).…”

Surface Nanosieving Polyether Sulfone Particles with Graphene Oxide Encapsulation for the Negative Isolation toward Extracellular Vesicles

“…Moreover, pathway analysis of the differential proteins quantified in IgAN and healthy donors using DAVID with the KEGG database showed that “lysosome” ( P = 3.24 × 10 –6 ) and “extracellular membrane (ECM)–receptor interaction pathway” ( P = 2.55 × 10 –5 ) were two major pathways that were closely related to cell injury and the progression of renal fibrosis. , Finally, the biological implications of the significantly upregulated proteins were studied. Among them, as high as 38.3% of the 47 significantly upregulated proteins (Table S4) such as AFM, ORM1, CP, SERPINA1, and C3 were previously reported to be closely related to IgAN. − Besides, among the proteins that were not previously found to have a direct association with IgAN, carbonic anhydrase 1 (CA1, 47.5 times, P = 6.51 × 10 –6 ), desmocollin-1 (DSC1, 5.51 times, P = 0.000683), tissue α- l -fucosidase (FUCA1, 3.15 times, P = 0.00297), and peroxiredoxin-2 (PRDX2, 2.85 times, P = 0.00484) were reported to play important roles in prevention of oxidative damage, regulation of basal immunity, and function of kidney injury. − Further validation of the relationship between such proteins with IgAN is ongoing. All of the results demonstrated that the NIEV strategy would provide a new tool for highly efficient EV isolation that would enable the screening of specific disease biomarkers for disease diagnosis and monitoring.…”