scholarly journals L-dopa-Dependent Effects of GLP-1R Agonists on the Survival of Dopaminergic Cells Transplanted into a Rat Model of Parkinson Disease

2021 ◽  
Vol 22 (22) ◽  
pp. 12346
Author(s):  
Osama F. Elabi ◽  
Jeffrey S. Davies ◽  
Emma L. Lane

Cell therapy is a promising treatment for Parkinson’s disease (PD), however clinical trials to date have shown relatively low survival and significant patient-to-patient variability. Glucagon Like Peptide-1 receptor (GLP-1R) agonists have potential neuroprotective effects on endogenous dopaminergic neurons. This study explores whether these agents could similarly support the growth and survival of newly transplanted neurons. 6-OHDA lesioned Sprague Dawley rats received intra-striatal grafts of dopaminergic ventral mesencephalic cells from embryonic day 14 Wistar rat embryos. Transplanted rats then received either saline or L-dopa (12 mg/kg) administered every 48 h prior to, and following cell transplantation. Peripheral GLP-1R agonist administration (exendin-4, 0.5 μg/kg twice daily or liraglutide, 100 μg/kg once daily) commenced immediately after cell transplantation and was maintained throughout the study. Graft survival increased under administration of exendin-4, with motor function improving significantly following treatment with both exendin-4 and liraglutide. However, this effect was not observed in rats administered with L-dopa. In contrast, L-dopa treatment with liraglutide increased graft volume, with parallel increases in motor function. However, this improvement was accompanied by an increase in leukocyte infiltration around the graft. The co-administration of L-dopa and exendin-4 also led to indicators of insulin resistance not seen with liraglutide, which may underpin the differential effects observed between the two GLP1-R agonists. Overall, there may be some benefit to the supplementation of grafted patients with GLP-1R agonists but the potential interaction with other pharmacological treatments needs to be considered in more depth.

2014 ◽  
Vol 31 (4) ◽  
pp. 233-243
Author(s):  
Ivana Stojanović ◽  
Srđan Ljubisavljević ◽  
Ivana Stevanović ◽  
Slavica Stojnev ◽  
Radmila Pavlović ◽  
...  

Summary The aim of this study was to investigate the exogenous agmatine influence on nitrosative and oxidative stress parameters in acute phase of multiple sclerosis (MS) experimental model, experimental autoimmune encephalomyelitis (EAE). EAE was induced by subcutaneous injection of myelin basic protein (50 μg per animal). Sprague-Dawley rats were divided into five groups: I group - (CG), treated by PBS (i.p.), II group - (EAE), III group - (CFA), treated with Complete Freund’s adjuvant (0.2 ml subcutaneously), IV group - (EAE+AGM), treated by agmatine (75 mg/kg bw i.p.) upon EAE induction and V group - (AGM), received only agmatine in the same dose. The animals were treated every day during experiment - from day 0 to 15, and clinically scored every day. They were sacrificed on day 16 from MBP application. NO2+NO3, S-nitrosothiols (RSNO), malondyaldehide (MDA) and reduced glutathione (GSH) concentrations and superoxide dismutase (SOD) activity were determined in rat whole encephalitic mass (WEM) and cerebellum homogenates. Agmatine exerted strong protective effects on EAE clinical symptoms (p<0.05). In EAE brain homogenates, NO2+NO3, RSNO and MDA concentrations were increased compared to CG values. Agmatine treatment diminished NO2+NO3, RSNO and MDA levels in EAE animals (p<0.05). In EAE rats, GSH level and SOD activity were decreased compared to CG values, but agmatine treatment increased both parameters compared to EAE untreated animals (p<0.05). Immunohistochemical staining supported the clinical and biochemical findings in all groups. The CNS changes in EAE are successfully supressed by agmatine application, which could be the the new aspect of the neuroprotective effects of agmatine.


2013 ◽  
Vol 304 (10) ◽  
pp. E1105-E1117 ◽  
Author(s):  
Manuel Gil-Lozano ◽  
Marina Romaní-Pérez ◽  
Verónica Outeiriño-Iglesias ◽  
Eva Vigo ◽  
Patricia L. Brubaker ◽  
...  

Exendin-4 (Ex-4) is a natural agonist of the glucagon-like peptide-1 (GLP-1) receptor, currently being used as a treatment for type 2 diabetes mellitus due to its insulinotropic properties. Previous studies have revealed that acute administration of both GLP-1 and, in particular, Ex-4 potently stimulates hypothalamic-pituitary-adrenal (HPA) axis activity. In this work, the effects of prolonged Ex-4 exposure on HPA function were explored. To this end, Sprague-Dawley rats were subjected to a daily regimen of two Ex-4 injections (5 μg/kg sc) for a minimum of 7 days. We found that subchronic Ex-4 administration produced a number of effects that resemble chronic stress situations, including hyperactivation of the HPA axis during the trough hours, disruption of glucocorticoid circadian secretion, hypertrophy of the adrenal gland, decreased adrenal gland sensitivity, impaired pituitary-adrenal stress responses, and reductions in both food intake and body weight. In addition, a threefold increase in diuresis was observed followed by a 1.5-fold increase in water intake; these latter effects were abolished by adrenalectomy. Together, these findings indicate that Ex-4 induces a profound dysregulation of HPA axis activity that may also affect renal function.


2020 ◽  
pp. 1-10 ◽  
Author(s):  
Yuki Shimizu ◽  
Hiroshi Hara ◽  
Tohru Hira

Abstract Although glucose is the best-known nutrient to stimulate glucagon-like peptide-1 (GLP-1) secretion, dietary peptides also potently stimulate GLP-1 secretion. Certain peptide fragments derived from dietary proteins possess dipeptidyl peptidase-4 (DPP-4) inhibitory activity in vitro. Hence, we hypothesised that dietary peptides protect GLP-1 from degradation through attenuating DPP-4 activity in vivo. Here, we compared GLP-1 responses with dietary proteins, a carbohydrate and a lipid (Intralipos) in rats having or not having plasma DPP-4 activity. Plasma GLP-1 concentrations clearly increased by oral administration of whey protein (2–4 g/kg), but not by that of dextrin (2–4 g/kg), in control rats (untreated Sprague–Dawley rats and F344/Jcl rats), having DPP-4 activity. In contrast, dextrin administration increased the plasma GLP-1 concentrations as the whey protein administration did, in rats having reduced or no DPP-4 activity (a DPP-4 inhibitor, sitagliptin-treated Sprague–Dawley rats or DPP-4-deficient F344/DuCrl/Crlj rats). DPP-4 inhibition by sitagliptin treatment also enhanced GLP-1 response to Intralipos, and casein, but the treatment did not further enhance GLP-1 response to whey protein. Intestinal GLP-1 content and gastric emptying rate were not associated with differences in GLP-1 responses to test nutrients. The luminal contents from rats administered whey protein decreased DPP-4 activity in vitro. These results suggest that GLP-1 released by dextrin, Intralipos and casein was immediately degraded by DPP-4, while GLP-1 released by whey protein was less degraded. Our study provides novel in vivo evidence supporting the hypothesis that dietary peptides not only stimulate GLP-1 secretion but also inhibit DPP-4 activity to potentiate GLP-1 response.


Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3229
Author(s):  
Chih-Cheng Wu ◽  
Chih-Jen Hung ◽  
Ya-Yu Wang ◽  
Shih-Yi Lin ◽  
Wen-Ying Chen ◽  
...  

Anesthetics, particularly volatile anesthetics, have been shown to impair glucose metabolism and cause hyperglycemia, closely linking them with mortality and morbidity as related to surgery. Beyond being an anesthetic used for general anesthesia and sedation, intravenous hypnotic propofol displays an effect on glucose metabolism. To extend the scope of propofol studies, its effects on glucose metabolism were evaluated in male Sprague-Dawley rats of various ages. Unlike chloral hydrate and isoflurane, propofol had little effect on basal glucose levels in rats at 2 months of age, although it did reduce chloral hydrate- and isoflurane-induced hyperglycemia. Propofol reduced postload glucose levels after either intraperitoneal or oral administration of glucose in both 7- and 12-month-old rats, but not those at 2 months of age. These improved effects regarding propofol on glucose metabolism were accompanied by an increase in insulin, fibroblast growth factor-21 (FGF-21), and glucagon-like peptide-1 (GLP-1) secretion. Additionally, an increase in hepatic FGF-21 expression, GLP-1 signaling, and FGF-21 signaling, along with a decrease in endoplasmic reticulum (ER) stress, were noted in propofol-treated rats at 7 months of age. Current findings imply that propofol may turn into insulin-sensitizing molecules during situations of existing insulin resistance, which involve FGF-21, GLP-1, and ER stress.


2020 ◽  
Vol 26 (12) ◽  
pp. 1388-1401
Author(s):  
Angélica Vega-García ◽  
Luisa Rocha ◽  
Rosalinda Guevara-Guzmán ◽  
Christian Guerra-Araiza ◽  
Iris Feria-Romero ◽  
...  

Background: Neuroinflammation induced in response to damage caused by status epilepticus (SE) activates the interleukin (IL)1-β pathway and proinflammatory proteins that increase vulnerability to the development of spontaneous seizure activity and/or epilepsy. Objectives: The study aimed to assess the short-term anti-inflammatory and neuroprotective effects of Magnolia officinalis (MO) on recurrent SE in immature rats. Methods: Sprague-Dawley rats at PN day 10 were used; n = 60 rats were divided into two control groups, SHAM and KA, and two experimental groups, MO (KA-MO) and Celecoxib (KA-Clbx). The anti-inflammatory effect of a single dose of MO was evaluated at 6 and 24 hr by Western blotting and on day 30 PN via a subchronic administration of MO to assess neuronal preservation and hippocampal gliosis by immunohistochemistry for NeunN and GFAP, respectively. Results: KA-MO caused a decrease in the expression of IL1-β and Cox-2 at 6 and 24 h post-treatment, a reduction in iNOS synthase at 6 and 24 hr post-treatment and reduced neuronal loss and gliosis at postnatal day 30, similar to Clbx. Conclusion: The results indicating that Magnolia officinalis is an alternative preventive treatment for early stages of epileptogenesis are encouraging.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Fang-hao Zheng ◽  
Ping Wei ◽  
Hui-ling Huo ◽  
Xue-feng Xing ◽  
Fei-long Chen ◽  
...  

Herb Ephedra(Ma Huang in Chinese) andRamulus Cinnamomi(Gui Zhi in Chinese) are traditional Chinese herbs, often used together to treat asthma, nose and lung congestion, and fever with anhidrosis. Due to the adverse effects of ephedrine, clinical use of Ma Huang is restricted. However, Gui Zhi extract has been reported to decrease spontaneous activity in rats and exert anti-inflammatory and neuroprotective effects. The present study explored the possible inhibitory effect of Gui Zhi on Ma Huang-induced neurotoxicity in rats when the two herbs were used in combination. All Ma Huang and Ma Huang-Gui Zhi herb pair extracts were prepared using methods of traditional Chinese medicine and were normalized based on the ephedrine content. Two-month-old male Sprague-Dawley rats (n=6rats/group) were administered Ma Huang or the Ma Huang-Gui Zhi herb pair extracts for 7 days (ephedrine = 48 mg/kg), and locomotor activity was measured. After 7 days, oxidative damage in the prefrontal cortex was measured. Gui Zhi decreased hyperactivity and sensitization produced by repeated Ma Huang administration and attenuated oxidative stress induced by Ma Huang. The results of this study demonstrate the neuroprotective potential of Gui Zhi in Ma Huang-induced hyperactivity and oxidative damage in the prefrontal cortex of rats when used in combination.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yun Han ◽  
Xiao-kun Geng ◽  
Hangil Lee ◽  
Fengwu Li ◽  
Yuchuan Ding

Background and Purpose. Studies have shown that interischemia hypothermia is able to reduce the size of myocardial infarctions and improve their clinical outcomes. The present study determined whether interischemia hypothermia induced by the pharmacological approach induced stronger neuroprotection in ischemic brains. Methods. Adult male Sprague Dawley rats were studied in 4 groups: (1) sham; (2) stroke; (3) stroke treated with pharmacological hypothermia before reperfusion (interischemia hypothermia); and (4) stroke treated with pharmacological hypothermia after reperfusion is initiated (inter-reperfusion hypothermia). The combination of chlorpromazine and promethazine with dihydrocapsaicin (DHC) was used to induce hypothermia. To compare the neuroprotective effects of drug-induced hypothermia between the interischemia and inter-reperfusion groups, brain damage was evaluated using infarct volume and neurological deficits at 24 h reperfusion. In addition, mRNA expressions of NADPH oxidase (NOX) subunits (gp91phox, p67phox, p47phox, and p22phox) and glucose transporter subtypes (GLUT1 and GLUT3) were determined by real-time PCR at 6 and 24 h reperfusion. ROS production was measured by flow cytometry assay at the same time points. Results. In both hypothermia groups, the cerebral infarct volumes and neurological deficits were reduced in the ischemic rats. At 6 and 24 h reperfusion, ROS production and the expressions of NOX subunits and glucose transporter subtypes were also significantly reduced in both hypothermia groups as compared to the ischemic group. While there were no statistically significant differences between the two hypothermia groups at 6 h reperfusion, brain damage was significantly further decreased by interischemia hypothermia at 24 h. Conclusion. Both interischemia and inter-reperfusion pharmacological hypothermia treatments play a role in neuroprotection after stroke. Interischemia hypothermia treatment may be better able to induce stronger neuroprotection after ischemic stroke. This study provides a new avenue and reference for stronger neuroprotective hypothermia before vascular recanalization in stroke patients.


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