Zinc oxide nanoparticles and spironolactone-enhanced Nrf2/HO-1 pathway and inhibited Wnt/ß-catenin pathway in adenine-induced nephrotoxicity in rats.

OBJECTIVE: To investigate the renoprotective, the antioxidant, and the anti-inflammatory impact of a combination of SPL and ZnO-NPs to combat against chronic kidney disease (CKD). METHODS: In total, 50 males of rats were distributed into 5 groups (10 rats each); normal group, adenine sulfate (0.25% in diet for 10 days) (CKD) group. After the last dose of adenine sulfate, rats were divided into three groups: SPL + Adenine sulfate group; rats were treated orally by mixing SPL (20 mg/kg/day) into chow for 8 weeks, ZnO-NPs + Adenine sulfate group; rats were injected intraperitoneally with ZnO-NPs (5 mg/kg) three times weekly for 8 weeks, ZnO-NPs + SPL + Adenine sulfate group; rats were injected with the same previous doses for 8 weeks. RESULTS: Each of SPL and ZnO-NPs up-regulated antioxidant genes (Nrf2 and HO-1), down-regulated fibrotic and inflammatory genes (TGF-ß1, Wnt7a, ß-catenin, fibronectin, collagen IV, α-SMA, TNF-α, and IL-6) compared to CKD. Furthermore, a combination of SPL and ZnO-NPs resulted in a greater improvement in the measured parameters than a single treatment. CONCLUSION: The therapeutic role of SPL was enhanced by the antioxidant and the anti-inflammatory role of ZnO-NPs, which presented a great renoprotective effect against CKD.

Possible cardioprotective role of NaHS on ECG and oxidative stress markers in an unpredictable chronic mild stress model in rats.

The protective effect of H2S against various body organ injuries has been described. The aim of this work is to investigate the potential role of sodium hydrosulfide (NaHS) as an H2S donor in chronic mild stress induced changes in the rat heart. Forty adult male Sprague Dawley rats were assigned to four groups: control, stressed group, stressed rats treated with aminooxyacetic acid (AOAA), and stressed rats treated with NaHS. Arterial blood pressure (ABP) was recorded. Serum adrenaline, MDA, and GSH levels were measured. Chronic stress significantly increased HR and ABP. AOAA produced similar changes, while NaHS mitigated the rise in HR and ABP. Both stressed and AOAA-treated stressed groups showed a significant decrease in QRS amplitude and a shortening of the RR, QT, and QTc intervals with an elevation of the ST segment. NaHS produced a significant improvement in ECG recordings. Chronic stress produced a significant rise of adrenaline and MDA levels with a significant decline in GSH levels. The AOAA-treated stressed group showed similar elevations. NaHS treatment caused significant reduction in adrenaline and MDA levels but significantly improved GSH levels. In conclusion, H2S donor has a cardioprotective effect against stress-induced cardiovascular diseases through amelioration of the oxidative stress and raised adrenaline levels induced by chronic stress exposure.

Organotypic slice culture model demonstrates inter-neuronal spreading of alpha-synuclein aggregates.

Here we describe the use of an organotypic hippocampal slice model for studying α-synuclein aggregation and inter-neuronal spreading initiated by microinjection of pre-formed α-synuclein fibrils (PFFs). PFF injection at dentate gyrus (DG) templates the formation of endogenous α-synuclein aggregates in axons and cell bodies of this region that spread to CA3 and CA1 regions. Aggregates are insoluble and phosphorylated at serine-129, recapitulating Lewy pathology features found in Parkinson's disease and other synucleinopathies. The model was found to favor anterograde spreading of the aggregates. Furthermore, it allowed development of slices expressing only serine-129 phosphorylation-deficient human α-synuclein (S129G) using an adeno-associated viral (AAV) vector in α-synuclein knockout slices. The processes of aggregation and spreading of α-synuclein were thereby shown to be independent of phosphorylation at serine-129. We provide methods and highlight crucial steps for PFF microinjection and characterization of aggregate formation and spreading. Slices derived from genetically engineered mice or manipulated using viral vectors allow testing of hypotheses on mechanisms involved in the formation of α-synuclein aggregates and their prion-like spreading.

Age-related changes in carotid vascular responses to adenosine and nitric oxide in the rat: in vitro and in vivo studies.

We investigated how the ability of adenosine to release nitric oxide (NO) from carotid artery in vitro, and dilator responses evoked in carotid circulation in vivo by systemic infusion of adenosine, change with age in rats of 4-5, 10-12, and 42-44 wk (juvenile, mature, and middle aged). A secondary aim was to follow age-related changes in carotid/cerebral autoregulation. In opened carotid artery, graded doses of adenosine evoked graded increases in NO output measured with a NO sensor that were greater in mature and middle-aged than juvenile rats. Infusion of adenosine to reduce mean arterial pressure (ABP) to approximately 60 mmHg increased carotid vascular conductance (CVC) in all groups, but the increase was larger in mature rats; carotid blood flow (CBF) was unchanged in juvenile, increased in mature, but fell in 4/8 middle-aged rats. The NO synthase inhibitor nitro l-arginine methyl ester (l-NAME; 10 mg/kg iv) increased baseline ABP in all groups but caused larger percentage reductions in baseline CVC and CBF in mature and middle-aged than juvenile rats. Thereafter, the adenosine-evoked increase in CVC was unchanged in juvenile and middle-aged rats, yet CBF remained constant in juvenile but increased in middle-aged rats. In mature rats, the evoked increases in CVC and CBF were attenuated and further attenuated by l-NAME at 30 mg/kg. We propose that the ability of adenosine to release NO and cause vasodilation in the carotid artery and its circulation is greater in mature, than juvenile or middle-aged rats, but NO has greater tonic dilator influence in carotid circulation of mature and middle-aged than juvenile rats. By middle age, the lower limit of cerebral autoregulation has increased such that the tonic dilator influence of NO on ABP and CVC limits autoregulation of CBF to depressor responses. However, partial NO synthase inhibition overcomes this impairment, raising baseline ABP and allowing adenosine-evoked increases in CVC to increase CBF.

Age-related changes in the sympathetic innervation of cerebral vessels and in carotid vascular responses to norepinephrine in the rat: in vitro and in vivo studies.

We hypothesized that the density of sympathetic noradrenergic innervation of cerebral arteries and vasoconstrictor responses evoked in carotid circulation by norepinephrine (NE) increase with maturation and age. In rats of 4-5, 10-12, and 42-44 wk of age (juvenile, mature, middle aged), glyoxylic acid applied to stretch preparations showed the density of noradrenergic nerves in basilar and middle cerebral arteries was greater in mature than juvenile or middle-aged rats. In anesthetized rats, infusion of NE (2.5 mug/kg iv) increased mean arterial pressure (ABP) to approximately 180 mmHg in mature and middle-aged but to only approximately 150 mmHg in juveniles rats. Concomitantly, carotid blood flow (CBF) decreased in mature and middle-aged rats but remained constant in juveniles because carotid vascular conductance (CVC) decreased more in mature and middle-aged than juvenile rats. We also hypothesized that nitric oxide (NO) blunts cerebral vasoconstrictor responses to NE. Inhibition of NO synthase with l-NAME (10 mg/kg iv) induced similar increases in baseline ABP in each group, but larger decreases in CVC and CBF in mature and middle-aged than juvenile rats. Thereafter, the NE-evoked increase in ABP was similar in juvenile and mature but accentuated in middle-aged rats. Concomitantly, NE decreased CVC in juvenile and mature, but not middle-aged rats; in them, CBF increased. Thus, in juvenile rats, sparse noradrenergic innervation of cerebral arteries is associated with weak NE-evoked pressor responses and weak carotid vasoconstriction that allows autoregulation of CBF. Cerebral artery innervation density increases with maturation but lessens by middle age. Meanwhile, NE-evoked pressor responses and carotid vasoconstriction are stronger in mature and middle-aged rats, such that CBF falls despite the evoked increase in ABP. We propose that in juvenile and mature rats, NO does not modulate NE-evoked pressor responses, cerebral vasoconstriction, or CBF autoregulation, but by middle age, NO limits pressor responses and prevents breakthrough of CBF in the upper part of the autoregulatory range.