Monoisoamyl DMSA reduced copper-induced neurotoxicity by lowering 8-OHdG level, amyloid beta and Tau protein expressions in Sprague-Dawley rats

Metallomics ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1428-1448
Author(s):  
Jayant Patwa ◽  
Ashima Thakur ◽  
Abha Sharma ◽  
S. J. S. Flora

Copper dyshomeostasis has long been linked with several neurodegenerative disorders.


2021 ◽  
Author(s):  
Nada Alaa Moustafa ◽  
Mohammed Abdelhamed El-Sayed ◽  
Somia Hassan Abdallah ◽  
Noha M. Hazem ◽  
Doaa Attia Abdelmoety

Abstract Let-7 microRNAs may contribute to neurodegeneration, including Alzheimer's disease (AD), but, they were not investigated in Streptozotocin (STZ)-induced AD. Letrozole increases the expression of Let-7 in cell lines, with conflicting evidence regarding its effects on memory. This study examined Let-7 microRNAs in STZ-induced AD, their correlation with memory and hyperphosphorylated Tau (p-Tau) and the effects of Letrozole on them. Seven groups of adult Sprague Dawley rats were used: Intact, Letrozole, Letrozole Vehicle, STZ (with AD induced by intracerebroventricular injection of STZ in artificial CSF), CSF Control, STZ + Letrozole (STZ-L), and CSF + Letrozole Vehicle. Alternation percentage in T-maze was used as a measure of working memory. Let-7a, b and e and p-Tau levels in the hippocampus were estimated using qRT-PCR and ELISA, respectively. There were significant decreases in alternation percentage and increase in p-Tau in the STZ, Letrozole and STZ-L groups. Expression levels of all studied microRNAs were significantly elevated in the Letrozole and the STZ + L groups, with no difference between the two, suggesting that this elevation was due to Letrozole. Negative correlations were found between alternation percentage and the levels of all studied microRNAs, while positive ones were found between p-Tau concentration and the levels of studied microRNAs. These findings support the theory that Letrozole aggravates pre-existing lesions and add to the evidence of Let-7 neurotoxicity.



Author(s):  
Alexander J. Moszczynski ◽  
Madeline Harvey ◽  
Niveen Fulcher ◽  
Cleusa de Oliveira ◽  
Patrick McCunn ◽  
...  

Abstract Although it has been suggested that the co-expression of multiple pathological proteins associated with neurodegeneration may act synergistically to induce more widespread neuropathology, experimental evidence of this is sparse. We have previously shown that the expression of Thr175Asp-tau (tauT175D) using somatic gene transfer with a stereotaxically-injected recombinant adeno-associated virus (rAAV9) vector induces tau pathology in rat hippocampus. In this study, we have examined whether the co-expression of human tauT175D with mutant human TDP-43 (TDP-43M337V) will act synergistically. Transgenic female Sprague-Dawley rats that inducibly express mutant human TDP-43M337V using the choline acetyltransferase (ChAT) tetracycline response element (TRE) driver with activity modulating tetracycline-controlled transactivator (tTA) were utilized in these studies. Adult rats were injected with GFP-tagged tau protein constructs in a rAAV9 vector through bilateral stereotaxic injection into the hippocampus. Injected tau constructs were: wild-type GFP-tagged 2N4R human tau (tauWT; n = 8), GFP-tagged tauT175D 2N4R human tau (tauT175D, pseudophosphorylated, toxic variant, n = 8), and GFP (control, n = 8). Six months post-injection, mutant TDP-43M337V expression was induced for 30 days. Behaviour testing identified motor deficits within 3 weeks after TDP-43 expression irrespective of tau expression, though social behaviour and sensorimotor gating remained unchanged. Increased tau pathology was observed in the hippocampus of both tauWT and tauT175D expressing rats and tauT175D pathology was increased in the presence of cholinergic neuronal expression of human TDP-43M337V. These data indicate that co-expression of pathological TDP-43 and tau protein exacerbate the pathology associated with either individual protein.



2009 ◽  
Vol 37 (03) ◽  
pp. 519-529 ◽  
Author(s):  
Dan Su ◽  
Han-Yi Li ◽  
Hao-Ran Yan ◽  
Peng-Fei Liu ◽  
Liu Zhang ◽  
...  

The traditional Chinese medical herb Astragalus, the dried root of Astragalus membranaceus (Fisch.) Bge., has been widely applied to treat patients with cardiovascular disease in China and has profound cardioprotective effects. This study investigated the effect of Astragalus on hemodynamic changes in adriamycin (ADR)-injured rat hearts and its underlying molecular mechanism. Sprague-Dawley rats were divided into four groups: control, ADR only, ADR + low dose of Astragalus and ADR + high dose of Astragalus. Rats were injected intraperitoneally with 6 equal doses of ADR (cumulative dose, 12 mg/kg) over a period of 2 weeks. Treatment of Astragalus began 1 day before the onset of ADR injection and was given orally once a day for 50 days (3.3 or 10 g/kg/day). Five weeks after the final injection of ADR, rats treated with ADR only showed a significant inhibition of cardiac diastolic function accompanied by the presence of ascites, a remarkable reduction in body weight and heart weight as well as survival rate compared to the controls. Moreover, SERCA2a mRNA and protein expressions in hearts were obviously downregulated by ADR. However, this impaired cardiac function was significantly improved in both doses of Astragalus feeding groups. The amount of ascites was also reduced in a similar extent in these 2 groups. Only the high dose treatment of Astragalus significantly attenuated the changes of SERCA2a expression in injured hearts and improved survival. These results indicated that Astragalus could improve cardiac function of ADR-injured rat hearts, which was partly mediated by upregulation of SERCA2a expression.



2021 ◽  
Author(s):  
Mariam Alawadhia ◽  
Farah Al Shammari ◽  
Fatemah Mulla Ali ◽  
Rama Almatar ◽  
Ayat Al-Duwaikhi ◽  
...  

Abstract BackgroundDexamethasone (DEX) induces intrauterine growth restriction (IUGR) in pregnant rats. IUGR can occur due to apoptosis of trophoblasts, which is believed to be inhibited by progesterone (P4). A group of genes called MTAs play a role in proliferation and apoptosis. MTA1 upregulates trophoblasts proliferation and differentiation, while MTA3 downregulates proliferation and induces apoptosis. Hence, we hypothesized that during IUGR, placental MTA1 decreases and MTA3 increases and this is reversed by P4 treatment. MethodsPregnant Sprague-Dawley rats were divided into 4 groups based on daily intraperitoneal injections: control (C, saline), DEX (DEX, 0.2 mg/kg/day), DEX and P4 (DEX + P4, DEX: 0.2 mg/kg/day, P4: 5 mg/kg/day) and P4-treated (P4, 5 mg/kg/day) groups. Injections were started on 15 dg until the day of dissection (19 or 21 dg). Gene and protein expressions of MTA1 and MTA3 were studied in the labyrinth (LZ) and basal (BZ) zones using real-time PCR and Western blotting, respectively. ResultsDEX treatment induced 18% reduction in fetal body weight (p<0.001) and 30% reduction in placental weight (p<0.01). Maternal P4 level was also significantly lower in DEX treated groups (p<0.05). MTA1 expression was decreased in the LZ (gene, p< 0.001) and BZ (protein p<0.01), while MTA3 protein expression was upregulated in the LZ with DEX treatment (p<0.001). These changes were reversed with P4 treatment. ConclusionThe findings of the present study indicate that DEX induces IUGR through changing the expression of placental MTA1 and MTA3 antigens and P4 improved pregnancy outcome by preventing the changes in MTAs expression.



2021 ◽  
Vol 12 ◽  
Author(s):  
Lin Xu ◽  
Chaonan Deng ◽  
Ying Zhang ◽  
Lina Zhao ◽  
Yan Linghu ◽  
...  

ObjectiveThis study aims to analyze the expressions of autophagy-related factors light chain 3 alpha (LC3A) and Beclin 1 and apoptosis-related factors B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X (BAX) in primary osteoblasts treated with sodium fluoride (NaF).MethodsOsteoblasts were extracted from Sprague-Dawley rats and treated with 0, 2.5, 5, and 10 mg/L NaF solutions, followed by 10 mmol/L 3-methyladenine (3-MA) for 24 h. The apoptotic rate was determined by flow cytometry, and the expressions of the autophagy- and apoptosis-related factors were measured by western blotting and real-time quantitative polymerase chain reaction.ResultsThe mRNA expressions of LC3A, Beclin 1, and BAX in the NaF-treated osteoblast group were higher than those in the control group, while the protein expressions of these factors in the NaF-treated group were significantly higher than those in the control group. However, the Bcl-2 protein expression in the NaF-treated osteoblasts was significantly decreased compared to that in the control cells. After the 3-MA treatment, the protein expressions of LC3A, Beclin 1, and Bcl-2 were significantly decreased compared with those of the NaF-treated group, whereas the expression of BAX increased. Moreover, the apoptosis rate was increased after the addition of the 3-MA inhibitor.ConclusionNaF stimulation promoted autophagy and apoptosis of the osteoblasts, suggesting the involvement of fluoride damage in these processes.



2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Kam Lok Wong ◽  
Yau Ming Lai ◽  
Ka Wan Li ◽  
Kai Fai Lee ◽  
Tzi Bun Ng ◽  
...  

Abstract A novel protein, designated as DOI, isolated from the Chinese yam (Dioscorea opposita Thunb.) could be the first protein drug for the treatment of menopausal syndrome and an alternative to hormone replacement therapy (HRT), which is known to have undesirable side effects. DOI is an acid- and thermo-stable protein with a distinctive N-terminal sequence Gly-Ile-Gly-Lys-Ile-Thr-Thr-Tyr-Trp-Gly-Gln-Tyr-Ser-Asp-Glu-Pro-Ser-Leu-Thr-Glu. DOI was found to stimulate estradiol biosynthesis in rat ovarian granulosa cells; induce estradiol and progesterone secretion in 16- to 18-month-old female Sprague Dawley rats by upregulating expressions of follicle-stimulating hormone receptor and ovarian aromatase; counteract the progression of osteoporosis and augment bone mineral density; and improve cognitive functioning by upregulating protein expressions of brain-derived neurotrophic factor and TrkB receptors in the prefrontal cortex. Furthermore, DOI did not stimulate the proliferation of breast cancer and ovarian cancer cells, which suggest it could be a more efficacious and safer alternative to HRT.



Author(s):  
D. J. McComb ◽  
J. Beri ◽  
F. Zak ◽  
K. Kovacs

Investigation of the spontaneous pituitary adenomas in rat have been limited mainly to light microscopic study. Furth et al. (1973) described them as chromophobic, secreting prolactin. Kovacs et al. (1977) in an ul trastructural investigation of adenomas of old female Long-Evans rats, found that they were composed of prolactin cells. Berkvens et al. (1980) using immunocytochemistry at the light microscopic level, demonstrated that some spontaneous tumors of old Wistar rats could contain GH, TSH or ACTH as well as PRL.



Author(s):  
F. G. Zaki ◽  
E. Detzi ◽  
C. H. Keysser

This study represents the first in a series of investigations carried out to elucidate the mechanism(s) of early hepatocellular damage induced by drugs and other related compounds. During screening tests of CNS-active compounds in rats, it has been found that daily oral administration of one of these compounds at a dose level of 40 mg. per kg. of body weight induced diffuse massive hepatic necrosis within 7 weeks in Charles River Sprague Dawley rats of both sexes. Partial hepatectomy enhanced the development of this peculiar type of necrosis (3 weeks instead of 7) while treatment with phenobarbital prior to the administration of the drug delayed the appearance of necrosis but did not reduce its severity.Electron microscopic studies revealed that early development of this liver injury (2 days after the administration of the drug) appeared in the form of small dark osmiophilic vesicles located around the bile canaliculi of all hepatocytes (Fig. 1). These structures differed from the regular microbodies or the pericanalicular multivesicular bodies. They first appeared regularly rounded with electron dense matrix bound with a single membrane. After one week on the drug, these vesicles appeared vacuolated and resembled autophagosomes which soon developed whorls of concentric lamellae or cisterns characteristic of lysosomes (Fig. 2). These lysosomes were found, later on, scattered all over the hepatocytes.



Author(s):  
D. J. McComb ◽  
J. Beri ◽  
F. Zak ◽  
K. Kovacs

Gonadotroph cell adenomas of the pituitary are infrequent in human patients and are not invariably associated with altered gonadal function. To date, no animal model of this tumor type exists. Herein, we describe spontaneous gonadotroph cell adenomas in old male and female Sprague-Dawley rats by histology, immunocytology and electron microscopy.The material consisted of the pituitaries of 27 male and 38 female Sprague Dawley rats, all 26 months of age or older, removed at routine autopsy. Sections of formal in-fixed, paraffin-embedded tissue were stained with hematoxylin-phloxine-saffron (HPS), the PAS method and the Gordon-Sweet technique for the demonstration of reticulin fibers. For immunostaining, sections were exposed to anti-rat β-LH, anti-ratβ-TSH, anti-rat PRL, anti-rat GH and anti-rat ACTH 1-39. For electron microscopy, tissue was fixed in 2.5% glutaraldehyde, postfixed in 1% OsO4 and embedded in epoxy-resin. Tissue fixed in 10% formalin, embedded in epoxy resin without osmification, was used for immunoelectron microscopy.



Author(s):  
Russell N. A. Cecil ◽  
H. Clarke Anderson

Unfixed proximal tibial epiphyseal growth plates were studied by freeze-etch to confirm the presence of extracellular calcifying matrix vesicles and to determine the substructure of matrix vesicle membranes as compared to plasma and other membranes of intact chondrocytes. Growth plates from 6-10 week old Sprague-Dawley rats were cut into 1x3 mm blocks whose long dimension was oriented either perpendicular or parallel to the long axis of the tibia. Some blocks were fixed at pH 7. 0 in 0. 2M cacodylate - buffered 2. 5% glutaraldehyde for 1 hour at 4ÅC. The blocks were immersed in 30% glycerol solution at 4ÅC for 1 hour, frozen in liquid nitrogen, and then fractured, etched for 2 minutes, and coated with platinum, carbon and 0. 2% Formvar solution. The replicas were cleaned with chromic acid, floated onto Formvar coated grids, and examined with a Phillips EM 300 electron microscope.Fixed and unfixed specimens appeared similar in ultrastructure. Chondrocytes, matrix, and matrix vesicles were identified. In specimens fractured parallel to the long axis of the tibia, the reserve, proliferative, hypertrophic, and calcifying zones could be discerned as described by light and electron microscopy.



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