scholarly journals Combination of Neuroprotective and Regenerative Agents for AGE-Induced Retinal Degeneration: In Vitro Study

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Guzel Bikbova ◽  
Toshiyuki Oshitari ◽  
Takayuki Baba ◽  
Shuichi Yamamoto

To determine the most effective combination of neuroprotective and regenerative agents for cultured retinal neurons from advanced glycation end products- (AGEs-) induced degeneration, retinal explants of 7 adult Sprague-Dawley rats were three-dimensionally cultured in collagen gel and incubated in serum-free media and in 7 media; namely, AGEs, AGEs + 100 μM citicoline, AGEs + 10 ng/mL NT-4, AGEs + 100 μM TUDCA, AGEs + 100 μM citicoline + TUDCA (doublet), and AGEs + 100 μM citicoline + TUDCA + 10 ng/mL NT-4 (triplet) were examined. The number of regenerating neurites was counted after 7 days of culture, followed by performing TUNEL and DAPI staining. The ratio of TUNEL-positive cells to the number of DAPI-stained nuclei was calculated. Immunohistochemical examinations for the active form of caspase-9 and JNK were performed. All of the neuroprotectants increased the number of neurites and decreased the number of TUNEL-positive cells. However, the number of neurites was significantly higher, and the number of TUNEL-positive cells and caspase-9- and JNK-immunopositive cells was fewer in the retinas incubated with the combined three agents. Combination solutions containing citicoline, TUDCA, and NT-4 should be considered for neuroprotective and regenerative therapy for AGE-related retinal degeneration.

1990 ◽  
Vol 258 (1) ◽  
pp. R263-R268 ◽  
Author(s):  
L. K. Kullama ◽  
V. Balaraman ◽  
J. R. Claybaugh ◽  
W. M. Ichimura ◽  
K. T. Nakamura

This in vitro study examined the ontogeny of arginine vasopressin (AVP) and arginine vasotocin (AVT) compared with norepinephrine (NE)-mediated contraction in rat thoracic aortas. Aortas from three age groups (2-3 days, 6-7 days, and 12 wk) of Sprague-Dawley rats were used. Ring segment resting length was adjusted to optimize tension developed to a dose that produces half-maximal tension of NE in Krebs solution (pH 7.4, 37 degrees C) and gassed with 95% O2-5% CO2. Cumulative dose-response curves were generated for KCl (5-100 mM), NE (10(-10)-10(-5) M), AVP, and AVT (both 10(-10)-10(-6) M) in the presence and absence of a selective V1 vasopressinergic inhibitor, [1-(beta-mercapto-beta,beta-cyclopentamethylenepropionic acid), 2-(O-methyl)tyrosine]arginine vasopressin ([d(CH2)5Tyr(Me)]AVP). A progressive increase in sensitivity among all age groups was found for KCl and NE. There was a slight decrease in sensitivity to both AVP and AVT in the 1st wk. Maximum contractile response to NE increased between 2-3 and 6-7 days, whereas no change was observed for KCl, AVP, or AVT. AVP- and AVT-mediated contractions were selectively inhibited by [d(CH2)5Tyr(Me)]-AVP. These results suggest 1) receptor-mediated contractility is present from 2 days of age for NE, AVP, and AVT; 2) sensitivity to KCl and NE increases progressively during postnatal development, whereas sensitivity to AVP and AVT slightly decreases in the 1st wk with no progressive age-related increase by 12 wk; 3) AVP and AVT mediate contraction via a similar V1-like receptor.


2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Yachao Zhao ◽  
Zhiwei Jia ◽  
Shanshan Huang ◽  
Yaohong Wu ◽  
Longgang Liu ◽  
...  

The functions of mesenchymal stem cells (MSCs) appear to decline with age due to cellular senescence, which could reduce the efficacy of MSCs-based therapies. Recently, MSCs have been identified in the nucleus pulposus, which offers great potential for intervertebral disc (IVD) repair. However, this potential might be affected by the senescence of nucleus pulposus MSCs (NPMSCs), but whether or not this exists remains unknown. The aim of this study was to investigate the age-related changes in NPMSCs. NPMSCs isolated from young (3-month-old) and old (14-month-old) Sprague-Dawley rats were cultured in vitro. Differences in morphology, proliferation, colony formation, multilineage differentiation, cell cycle, and expression ofβ-galactosidase (SA-β-gal) and senescent markers (p53, p21, and p16) were compared between groups. Both young and old NPMSCs fulfilled the criteria for definition as MSCs. Moreover, young NPMSCs presented better proliferation, colony-forming, and multilineage differentiation capacities than old NPMSCs. Old NPMSCs displayed senescent features, including significantly increased G0/G1 phase arrest, increased SA-β-gal expression, decreased S phase entry, and significant p53-p21-pRB pathway activation. Therefore, this is the first study demonstrating that senescent NPMSCs accumulate in IVD with age. The efficacy of NPMSCs is compromised by donor age, which should be taken into consideration prior to clinical application.


2015 ◽  
Vol 35 (3) ◽  
pp. 983-996 ◽  
Author(s):  
Yingmin Yao ◽  
Chanwei Dou ◽  
Zhongtang Lu ◽  
Xin Zheng ◽  
Qingguang Liu

Background & Aims: To investigate the expression and prognostic value of MACC1 in patients with HCC and identify the mechanism by which MACC1 inhibits HCC cell apoptosis. Methods: MACC1 and p-AKT expression was studied using immunohistochemistry of both HCC tissues and adjacent liver tissues. qRT-PCR and western immunoblotting were used to examine the expression of target genes at the mRNA and protein levels, respectively. The MTT assay was used to assess cell viability, and cell apoptosis was determined by DAPI staining, Annexin V/PI staining and Caspase 3/7 assay. Nude mice were used to perform in vivo experiments. Results: The overexpression of MACC1 was found in HCC tissues and was correlated with poor postsurgical prognosis. There was a positive relationship between MACC1 and p-AKT expression in HCC tissues. In vitro experiments showed that MACC1 repressed HCC cell apoptosis and promoted cell growth. Knockdown of c-MET abolished the anti-apoptotic function of MACC1. Next, MACC1 was verified to activate PI3K/AKT signaling by sensitizing HGF/c-MET signaling in HCC. MACC1 overexpression enhanced the HGF-driven phosphorylation of BAD, Caspase 9 and FKHRL1 and inhibited their pro-apoptotic functions in HCC cells. Finally, MACC1 was shown to inhibit cell apoptosis and promote HCC growth in vivo. Conclusions: This investigation revealed that MACC1 overexpression predicted worse prognosis after liver resection, which was attributed to the repression of HCC cell apoptosis via a molecular mechanism in which MACC1 accelerated the activation of the HGF/c-MET/PI3K/AKT pathway and phosphorylated BAD, Caspase 9 and FKHRL1, ultimately preventing their nuclear translocation and their pro-apoptotic function.


Author(s):  
Peng Wang ◽  
Xiao-Xia Hu ◽  
Ying-hui Li ◽  
Nan-Yong Gao ◽  
Guo-quan Chen ◽  
...  

This study was to evaluate the effect of resveratrol on the pharmacokinetics of ticagrelor in rats and the metabolism of ticagrelor in human CYP3A4 and liver microsomes. Eighteen Sprague-Dawley rats were randomly divided into three groups: group A (control group), group B (50mg/kg resveratrol), and group C (150mg/kg resveratrol ). After 30 minutes administration of resveratrol, a single dose of ticagrelor (18mg/kg) was administered orally. The vitro experiment was performed to examine the influence of resveratrol on ticagrelor metabolism in CYP3A4*1, human, and rat liver microsomes. Serial biological samples were assayed by validated UHPLC-MS/MS methods. In vivo study, the AUC and Cmax of ticagrelor in group B and C appeared to be significantly higher than the control group, while Vz/F and CLz/F of ticagrelor in group B and C were significantly decreased. In vitro study, resveratrol exhibited an inhibitory effect on CYP3A4*1, human and rat liver microsomes. The IC50 values of resveratrol were 56.75μM,69.07μM and 14.22μM, respectively. Our results indicated that resveratrol had a inhibitory effect on the metabolism of ticagrelor in vitro and vivo. It should be paid more attention to the clinical combination of resveratrol with ticagrelor and ticagrelor plasma concentration should be monitored to avoid the occurrence of adverse reaction.


2002 ◽  
Vol 282 (6) ◽  
pp. H2084-H2090 ◽  
Author(s):  
Yasuko Iwakiri ◽  
Ming-Hung Tsai ◽  
Timothy J. McCabe ◽  
Jean-Philippe Gratton ◽  
David Fulton ◽  
...  

Akt, also known as protein kinase B, is a serine/threonine kinase. Akt becomes active when phosphorylated by the activation of receptor tyrosine kinases, G protein-coupled receptors, and mechanical forces such as shear stress. Studies in vitro have shown that Akt can directly phosphorylate endothelial nitric oxide (NO) synthase (eNOS) and activate the enzyme, leading to NO production. The aim of this study was to test the hypothesis that the phosphorylation of eNOS plays a role in the enhanced NO production observed in early portal hypertension. Male Sprague-Dawley rats were subjected to either sham or portal vein ligation (PVL), and mesenteric arterial beds were used for ex vivo perfusion studies. Mesenteric arterial beds from PVL rats had an approximately 60–70% decrease in response to methoxamine (an α1-agonist and vasoconstrictor) compared with the sham group ( P < 0.01). When N G-monomethyl-l-arginine (a NOS inhibitor) was added to the perfusion, the difference in perfusion pressure between the two groups was abolished, suggesting that enhanced NO production in the PVL group blunted the response to the vasoconstrictor. The reduced responsiveness in PVL was not due to changes in eNOS expression but was due to an increase in enzyme-specific activity, suggesting posttranslational modification of eNOS. The phosphorylation of eNOS at Ser1176 was significantly increased by twofold ( P < 0.05) in the PVL group. Furthermore, PVL significantly increased Akt phosphorylation (an active form of Akt) by threefold ( P< 0.05). When vessels were treated with wortmannin (10 nM) to block the phosphatidylinositol-3-OH-kinase/Akt pathway, NO-induced vasodilatation was significantly reduced. These results suggest that the phosphorylation of eNOS by Akt activates the enzyme and may be the first step leading to an initial increase in NO production in portal hypertension.


Perfusion ◽  
2019 ◽  
Vol 34 (7) ◽  
pp. 578-583 ◽  
Author(s):  
Lien H Vu ◽  
John A Kellum ◽  
William J Federspiel ◽  
Matthew E Cove

Background: Extracorporeal carbon dioxide removal may be used to manage hypercapnia, but compared to dialysis, it’s not widely available. A recent in vitro study showed that dialysis with low bicarbonate dialysates removes CO2. Objective: To show that bicarbonate dialysis removes CO2 in an animal model to validate in-vitro findings and quantify the effect on arterial pH. Methods: Male Sprague-Dawley hypercapnic rats were dialyzed with either a conventional dialysate (PrismasolTM) or a bicarbonate-free dialysate (Bicarb0). The effect of dialysis on standard blood gases and electrolytes was measured. Results: Partial pressure of CO2 and bicarbonate concentration in blood decreased significantly after exposure to Bicarb0 compared to PrismasolTM (filter outflow values 12.8 vs 81.1 mmHg; p < 0.01 for CO2 and 3.5 vs 22.0 mmol/L; p < 0.01 for bicarbonate). Total CO2 content of blood was reduced by 459 mL/L during dialysis with Bicarb0 (filter inflow 546 ± 91 vs filter outflow 87 ± 52 mL/L; p < 0.01), but was not significantly reduced with PrismasolTM. Conclusions: Bicarbonate dialysis removes CO2 at rates comparable to existing low-flow ECCO2R.


2010 ◽  
Vol 71 (6) ◽  
pp. 384-397 ◽  
Author(s):  
Ning Zhong ◽  
Hankui Chen ◽  
Quanlin Zhao ◽  
Hongwei Wang ◽  
Xin Yu ◽  
...  

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