scholarly journals 2251

2017 ◽  
Vol 1 (S1) ◽  
pp. 60-60
Author(s):  
Andrea Lee Frump ◽  
Margie Albrecht ◽  
Sandra Breuils-Bonnet ◽  
Bakhtiyor Yakubov ◽  
Mary Beth Brown ◽  
...  

OBJECTIVES/SPECIFIC AIMS: Women with pulmonary arterial hypertension (PAH) exhibit superior right ventricular (RV) function and survival compared with men, a phenomenon attributed to poorly understood cardioprotective effects of 17β-estradiol (E2). We hypothesize that E2, through ERα, attenuates PH-induced RV dysfunction by upregulating the pro-contractile and pro-angiogenic peptide apelin. This ERα-mediated increase in apelin is mediated by the myocardial remodeling effector bone morphogenetic protein receptor 2 (BMPR2). METHODS/STUDY POPULATION: ERα, BMPR2, and apelin were measured (western blot) in RVs from patients with PAH-induced RV failure and in RV homogenates from male or female Sprague-Dawley rats with sugen/hypoxia (SuHx) or monocrotaline (MCT)-induced PH. H9c2 rat cardiomyoblasts and cardiac endothelial cells were stressed with TNF-α (10 ng/mL) or staurosporine (50 nM)±E2 (100 nM; 24 h). ERα-, BMPR2-, and apelin-dependence were evaluated by siRNA (5 pM). Downstream apelin target and pro-survival factor ERK1/2 expression was measured (western blot). p<0.05 by ANOVA was considered significant. RESULTS/ANTICIPATED RESULTS: ERα correlated positively with BMPR2 and apelin expression in SuHx-RVs and human RVs. Treatment of SuHx-PH rats with E2 or ERα agonist increased RV BMPR2 and apelin, whereas RV apelin was decreased in E2-treated hypoxic ERα knockout mice (p<0.05), but not in ERβ knockout mice. In H9c2 cells, E2 or ERα agonist attenuated TNF-α- or staurosporine-induced decreases in BMPR2, apelin, and phospho-ERK1/2 (p<0.05 for all endpoints). E2 protection was lost in presence of siRNA directed against ERα, BMPR2, or apelin (p<0.05). ERα was necessary for E2-mediated increases in BMPR2, apelin, and ERK1/2, and BMPR2 was required for the E2-mediated increase in apelin (p<0.05 for siRNA vs. scramble). ERα, BMPR2, and apelin protein was increased in decompensated human RVs but downstream phospho-ERK signaling was disrupted. DISCUSSION/SIGNIFICANCE OF IMPACT: E2, via ERα, increases BMPR2 and apelin in the failing RV and in stressed rat cardiomyoblasts. The E2-mediated increase in apelin is BMPR2-dependent and likely occurs through direct binding of ERα to the BMPR2 promoter. Harnessing this E2-ERα-BMPR2-apelin axis during RV compensation may lead to novel, RV-targeted therapies for PAH patients of either sex.

2001 ◽  
Vol 91 (4) ◽  
pp. 1828-1835 ◽  
Author(s):  
Nicole Stupka ◽  
Peter M. Tiidus

The effects of estrogen and ovariectomy on indexes of muscle damage after 2 h of complete hindlimb ischemia and 2 h of reperfusion were investigated in female Sprague-Dawley rats. The rats were assigned to one of three experimental groups: ovariectomized with a 17β-estradiol pellet implant (OE), ovariectomized with a placebo pellet implant (OP), or control with intact ovaries (R). It was hypothesized that following ischemia-reperfusion (I/R), muscle damage indexes [serum creatine kinase (CK) activity, calpain-like activity, inflammatory cell infiltration, and markers of lipid peroxidation (thiobarbituric-reactive substances)] would be lower in the OE and R rats compared with the OP rats due to the protective effects of estrogen. Serum CK activity following I/R was greater ( P < 0.01) in the R rats vs. OP rats and similar in the OP and OE rats. Calpain-like activity was greatest in the R rats ( P < 0.01) and similar in the OP and OE rats. Neutrophil infiltration was assessed using the myeloperoxidase (MPO) assay and immunohistochemical staining for CD43-positive (CD43+) cells. MPO activity was lower ( P < 0.05) in the OE rats compared with any other group and similar in the OP and R rats. The number of CD43+ cells was greater ( P < 0.01) in the OP rats compared with the OE and R rats and similar in the OE and R rats. The OE rats had lower ( P < 0.05) thiobarbituric-reactive substance content following I/R compared with the R and OP rats. Indexes of muscle damage were consistently attenuated in the OE rats but not in the R rats. A 10-fold difference in serum estrogen content may mediate this. Surprisingly, serum CK activity and muscle calpain-like activity were lower ( P< 0.05) in the OP rats compared with the R rats. Increases in serum insulin-like growth factor-1 content ( P < 0.05) due to ovariectomy were hypothesized to account for this finding. Thus both ovariectomy and estrogen supplementation have differential effects on indexes of I/R muscle damage.


2004 ◽  
Vol 287 (1) ◽  
pp. H203-H208 ◽  
Author(s):  
Jens Titze ◽  
Mehdi Shakibaei ◽  
Markus Schafflhuber ◽  
Gundula Schulze-Tanzil ◽  
Markus Porst ◽  
...  

Osmotically inactive skin Na+ storage is characterized by Na+ accumulation without water accumulation in the skin. Negatively charged glycosaminoglycans (GAGs) may be important in skin Na+ storage. We investigated changes in skin GAG content and key enzymes of GAG chain polymerization during osmotically inactive skin Na+ storage. Female Sprague-Dawley rats were fed a 0.1% or 8% NaCl diet for 8 wk. Skin GAG content was measured by Western blot analysis. mRNA content of key dermatan sulfate polymerization enzymes was measured by real-time PCR. The Na+ concentration in skin was determined by dry ashing. Skin Na+ concentration during osmotically inactive Na+ storage was 180–190 mmol/l. Increasing skin Na+ coincided with increasing GAG content in cartilage and skin. Dietary NaCl loading coincided with increased chondroitin synthase mRNA content in the skin, whereas xylosyl transferase, biglycan, and decorin content were unchanged. We conclude that osmotically inactive skin Na+ storage is an active process characterized by an increased GAG content in the reservoir tissue. Inhibition or disinhibition of GAG chain polymerization may regulate osmotically inactive Na+ storage.


Author(s):  
MANOBHARATHI VENGAIMARAN ◽  
KALAIYARASI DHAMODHARAN ◽  
MIRUNALINI SANKARAN

Objective: The central motive of this study is to explore the therapeutic impact of Diosgenin encapsulated Chitosan nanoparticles (DG@CS-NP) on mammary carcinogenesis in female Sprague Dawley rats via modulating hormonal status, cell proliferation, inflammatory responses, and Apoptosis. Methods: 7,12-dimethylbenz(a)anthracene (DMBA) was administered subcutaneously near the mammary gland (25 mg/kg b. wt) to provoke mammary tumor in female Sprague Dawley rats. Following the progress of a tumor, DMBA-induced tumor-bearing rats were medicated orally with 5 mg/kg b. wt of DG@CS-NP. Consequently, the expression of ER, PR, PCNA, Cyclin D1, NF-κB, TNF-α, Bcl-2, Caspases-3, and p53 in experimental rats were revealed via architectural immunohistochemistry. Further, Diosgenin interactions with these proteins were evidently confirmed by molecular docking analysis. Results: As a result, we noticed diminished levels of ER, PR, PCNA, Cyclin D1, NF-κB, TNF-α, and Bcl-2 expressions in DG@CS-NP medicated rats as well as with elevated levels of Caspases-3 and p53 expressions. In DMBA rats, the expressions were vice versa. Additionally, molecular docking analyses support these outcomes by highlighting the strong interaction between Diosgenin and breast cancer targets. Conclusion: These reports prove that DG@CS-NP imposes its therapeutic impact by hormonal adjustments, downregulating proteins involved in inflammation and cellular proliferation, and thereby promotes apoptosis by impeding apoptotic inhibitors.


2012 ◽  
Vol 302 (1) ◽  
pp. G145-G152 ◽  
Author(s):  
Vairappan Balasubramaniyan ◽  
Gavin Wright ◽  
Vikram Sharma ◽  
Nathan A. Davies ◽  
Yalda Sharifi ◽  
...  

Ammonia is central in the pathogenesis of hepatic encephalopathy, which is associated with dysfunction of the nitric oxide (NO) signaling pathway. Ornithine phenylacetate (OP) reduces hyperammonemia and brain water in cirrhotic animals. This study aimed to determine whether endothelial NO synthase activity is altered in the brain of cirrhotic animals, whether this is associated with changes in the endogenous inhibitor, asymmetric-dimethylarginine (ADMA) and its regulating enzyme, dimethylarginine-dimethylaminohydrolase (DDAH-1), and whether these abnormalities are restored by ammonia reduction using OP. Sprague-Dawley rats were studied 4-wk after bile duct ligation (BDL) ( n = 16) or sham operation ( n = 8) and treated with placebo or OP (0.6 g/kg). Arterial ammonia, brain water, TNF-α, plasma, and brain ADMA were measured using standard techniques. NOS activity was measured radiometrically, and protein expression for NOS enzymes, ADMA, DDAH-1, 4-hydroxynonenol (4HNE), and NADPH oxidase (NOX)-1 were measured by Western blotting. BDL significantly increased arterial ammonia ( P < 0.0001), brain water ( P < 0.05), and brain TNF-α ( P < 0.01). These were reduced significantly by OP treatment. The estimated eNOS component of constitutive NOS activity was significantly lower ( P < 0.05) in BDL rat, and this was significantly attenuated in OP-treated animals. Brain ADMA levels were significantly higher and brain DDAH-1 significantly lower in BDL compared with sham ( P < 0.01) and restored toward normal following treatment with OP. Brain 4HNE and NOX-1 protein expression were significantly increased in BDL rat brain, which were significantly decreased following OP administration. We show a marked abnormality of NO regulation in cirrhotic rat brains, which can be restored by reduction in ammonia concentration using OP.


2003 ◽  
Vol 284 (4) ◽  
pp. R916-R927 ◽  
Author(s):  
Zhi-Hua Zhang ◽  
Shun-Guang Wei ◽  
Joseph Francis ◽  
Robert B. Felder

In pathophysiological conditions, increased blood-borne TNF-α induces a broad range of biological effects, including activation of the hypothalamic-pituitary-adrenal axis and sympathetic drive. In urethane-anesthetized adult Sprague-Dawley rats, we examined the mechanisms by which blood-borne TNF-α activates neurons in paraventricular nucleus (PVN) of hypothalamus and rostral ventrolateral medulla (RVLM), two critical brain regions regulating sympathetic drive in normal and pathophysiological conditions. TNF-α (0.5 μg/kg), administered intravenously or into ipsilateral carotid artery (ICA), activated PVN and RLVM neurons and increased sympathetic nerve activity, arterial pressure, and heart rate. Responses to intravenous TNF-α were not affected by vagotomy but were reduced by mid-collicular decerebration. Responses to ICA TNF-α were substantially reduced by injection of the cyclooxygenase inhibitor ketorolac (150 μg) into lateral ventricle. Injection of PGE2 (50 ng) into lateral ventricle or directly into PVN increased PVN or RVLM activity, respectively, and sympathetic drive, with shorter onset latency than blood-borne TNF-α. These findings suggest that blood-borne cytokines stimulate cardiovascular and renal sympathetic responses via a prostaglandin-dependent mechanism operating at the hypothalamic level.


Pharmacology ◽  
2019 ◽  
Vol 104 (1-2) ◽  
pp. 71-80 ◽  
Author(s):  
Ying Zhang ◽  
Shaoyu Ren ◽  
Ying Ji ◽  
Yafeng Liang

Background: Our study investigated the therapeutic role and potential mechanisms of pterostilbene (PS) in diabetic nephropathy (DN) rats. Methods: DN models were established by high-fat diet after streptozotocin injection. A total of 50 Sprague-Dawley rats were randomly divided into control, DN, PS-treated groups (PS-H, PS-M, PS-L). PS was administered to rats by gavage for 8 weeks at 3 different doses (25, 10, and 5 mg/kg/day). The levels of oxidative stress activity (superoxide dismutase [SOD], malondialdehyde [MDA], glutathione peroxidase [GSH-PX]) and inflammatory factors (tumor necrosis factor [TNF]-α, interleukin (IL)-6, IL-1β, monocyte chemoattractant factor [MCP]-1) were detected by ­ELISA. TGF-β, Smad1, and fibronectin (FN) were measured through immunohistochemistry. The relative expressions of phospho-IκBα/IκBα, phospho-IκB kinases (IKK)β/IKKβ, phospho-nuclear factor-κB (NF-κB) p65/NF-κB p65 were detected by western blot. Results: Compared with DN group, the levels of TNF-α, IL-6, IL-1β, and MCP-1 were decreased in the PS-H group (p < 0.05). Meanwhile, the levels of SOD, MDA, GSH-PX improved in kidney and serum in PS-H groups (p< 0.05). PS also significantly decreased the level of phospho-NF-κB p65 and increased the levels of phospho- IKKβ and phospho-Iκ-Bα (p < 0.05). The results showed that PS treatment decreased TGF-β, Smad1, and FN expressions. Conclusion: PS had potential therapeutic effects on DN, which may be related to the regulation of NF-κB pathway.


2007 ◽  
Vol 292 (1) ◽  
pp. H245-H250 ◽  
Author(s):  
Zheng F. Ba ◽  
Ailing Lu ◽  
Tomoharu Shimizu ◽  
László Szalay ◽  
Martin G. Schwacha ◽  
...  

Although endothelin-1 (ET-1) induces vasoconstriction, it remains unknown whether 17β-estradiol (E2) treatment following trauma-hemorrhage alters these ET-1-induced vasoconstrictive effects. In addition, the role of the specific estrogen receptor (ER) subtypes (ER-α and ER-β) and the endothelium-localized downstream mechanisms of actions of E2 remain unclear. We hypothesized that E2 attenuates increased ET-1-induced vasoconstriction following trauma-hemorrhage via an ER-β-mediated pathway. To study this, aortic rings were isolated from male Sprague-Dawley rats following trauma-hemorrhage with or without E2 treatment, and alterations in tension were determined in vitro. Dose-response curves to ET-1 were determined, and the vasoactive properties of E2, propylpyrazole triol (PPT, ER-α agonist), and diarylpropionitrile (DPN, ER-β agonist) were determined. The results showed that trauma-hemorrhage significantly increased ET-1-induced vasoconstriction; however, administration of E2 normalized ET-1-induced vasoconstriction in trauma-hemorrhage vessels to the sham-operated control level. The ER-β agonist DPN counteracted ET-1-induced vasoconstriction, whereas the ER-α agonist PPT was ineffective. Moreover, the vasorelaxing effects of E2 were not observed in endothelium-denuded aortic rings or by pretreatment of the rings with a nitric oxide (NO) synthase inhibitor. Cyclooxygenase inhibition with indomethacin had no effect on the action of E2. Thus, E2 administration attenuates ET-1-induced vasoconstriction following trauma-hemorrhage via an ER-β-mediated pathway that is dependent on endothelium-derived NO synthesis.


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