scholarly journals GPR4 Knockout Improves the Neurotoxin-Induced, Caspase-Dependent Mitochondrial Apoptosis of the Dopaminergic Neuronal Cell

2020 ◽  
Vol 21 (20) ◽  
pp. 7517
Author(s):  
Md Ezazul Haque ◽  
Mahbuba Akther ◽  
Shofiul Azam ◽  
Dong-Kug Choi ◽  
In-Su Kim
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cell Death ◽  
G Protein ◽  
Apoptotic Cell ◽  
B Cell Lymphoma ◽  
Apoptotic Cell Death ◽  
G Protein Coupled Receptor ◽  
Human Neuroblastoma ◽  
G Protein Coupled

In Parkinson’s disease, mitochondrial oxidative stress-mediated apoptosis is a major cause of dopaminergic neuronal loss in the substantia nigra (SN). G protein-coupled receptor 4 (GPR4), previously recognised as an orphan G protein coupled-receptor (GPCR), has recently been claimed as a member of the group of proton-activated GPCRs. Its activity in neuronal apoptosis, however, remains undefined. In this study, we investigated the role of GPR4 in the 1-methyl-4-phenylpyridinium ion (MPP+) and hydrogen peroxide (H2O2)-treated apoptotic cell death of stably GPR4-overexpressing and stably GPR4-knockout human neuroblastoma SH-SY5Y cells. In GPR4-OE cells, MPP+ and H2O2 were found to significantly increase the expression levels of both mRNA and proteins of the pro-apoptotic Bcl-2-associated X protein (Bax) genes, while they decreased the anti-apoptotic B-cell lymphoma 2 (Bcl-2) genes. In addition, MPP+ treatment activated Caspase-3, leading to the cleavage of poly (ADP-ribose) polymerase (PARP) and decreasing the mitochondrial membrane potential (ΔΨm) in GPR4-OE cells. In contrast, H2O2 treatment significantly increased the intracellular calcium ions (Ca2+) and reactive oxygen species (ROS) in GPR4-OE cells. Further, chemical inhibition by NE52-QQ57, a selective antagonist of GPR4, and knockout of GPR4 by clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 decreased the Bax/Bcl-2 ratio and ROS generation, and stabilised the ΔΨm, thus protecting the SH-SY5Y cells from MPP+- or H2O2-induced apoptotic cell death. Moreover, the knockout of GPR4 decreased the proteolytic degradation of phosphatidylinositol biphosphate (PIP2) and subsequent release of the endoplasmic reticulum (ER)-stored Ca2+ in the cytosol. Our results suggest that the pharmacological inhibition or genetic deletion of GPR4 improves the neurotoxin-induced caspase-dependent mitochondrial apoptotic pathway, possibly through the modulation of PIP2 degradation-mediated calcium signalling. Therefore, GPR4 presents a potential therapeutic target for neurodegenerative disorders such as Parkinson’s disease.

scholarly journals Niacin and Butyrate: Nutraceuticals Targeting Dysbiosis and Intestinal Permeability in Parkinson’s Disease

Nutrients ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 28
Author(s):  
Tennekoon B. Karunaratne ◽  
Chijioke Okereke ◽  
Marissa Seamon ◽  
Sharad Purohit ◽  
Chandramohan Wakade ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Tight Junction ◽  
G Protein ◽  
Intestinal Permeability ◽  
Macrophage Polarization ◽  
Tight Junction Proteins ◽  
G Protein Coupled Receptor ◽  
G Protein Coupled ◽  
Junction Proteins

Dysbiosis is implicated by many studies in the pathogenesis of Parkinson’s disease (PD). Advances in sequencing technology and computing have resulted in confounding data regarding pathogenic bacterial profiles in conditions such as PD. Changes in the microbiome with reductions in short-chain fatty acid (SCFA)-producing bacteria and increases in endotoxin-producing bacteria likely contribute to the pathogenesis of PD. GPR109A, a G-protein coupled receptor found on the surface of the intestinal epithelium and immune cells, plays a key role in controlling intestinal permeability and the inflammatory cascade. The absence of GPR109A receptors is associated with decreased concentration of tight junction proteins, leading to increased intestinal permeability and susceptibility to inflammation. In inflammatory states, butyrate acts via GPR109A to increase concentrations of tight junction proteins and improve intestinal permeability. Niacin deficiency is exacerbated in PD by dopaminergic medications. Niacin supplementation has been shown to shift macrophage polarization from pro-inflammatory to an anti-inflammatory profile. Niacin and butyrate, promising nutrients and unique ligands for the G protein-coupled receptor GPR109A, are reviewed in this paper in detail.

The effect of intra-striatal administration of GPR55 agonist (LPI) and antagonist (ML193) on sensorimotor and motor functions in a Parkinson’s disease rat model

2020 ◽  
pp. 1-7
Author(s):  
Iman Fatemi ◽  
Abbas Abdollahi ◽  
Ali Shamsizadeh ◽  
Mohammad Allahtavakoli ◽  
Ali Roohbakhsh
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Locomotor Activity ◽  
G Protein ◽  
Rat Model ◽  
Field Tests ◽  
Motor Deficits ◽  
G Protein Coupled Receptor ◽  
Motor Functions ◽  
G Protein Coupled

Abstract Objective: G protein-coupled receptor 55 (GPR55) is an orphan G protein-coupled receptor with various physiological functions. Recent evidence suggests that this receptor may be involved in the control of motor functions. Therefore, in the present study, we evaluated the effects of intra-striatal administration of GPR55 selective ligands in a rat model of Parkinson’s disease. Methods: Experimental Parkinson was induced by unilateral intra-striatal administration of 6-hydroxydopamine (6-OHDA, 10 µg/rat). L-α-lysophosphatidylinositol (LPI, 1 and 5 µg/rat), an endogenous GPR55 agonist, and ML193 (1 and 5 µg/rat), a selective GPR55 antagonist, were injected into the striatum of 6-OHDA-lesioned rats. Motor performance and balance skills were evaluated using the accelerating rotating rod and the ledged beam tests. The sensorimotor function of the forelimbs and locomotor activity were assessed by the adhesive removal and open field tests, respectively. Results: 6-OHDA-lesioned rats had impaired behaviours in all tests. Intra-striatal administration of LPI in 6-OHDA-lesioned rats increased time on the rotarod, decreased latency to remove the label, with no significant effect on slip steps, and locomotor activity. Intra-striatal administration of ML193 also increased time on the rotarod, decreased latency to remove the label and slip steps in 6-OHDA-lesioned rats mostly at the dose of 1 µg/rat. Conclusions: This study suggests that the striatal GPR55 is involved in the control of motor functions. However, considering the similar effects of GPR55 agonist and antagonist, it may be concluded that this receptor has a modulatory role in the control of motor deficits in an experimental model of Parkinson.

Lack of association between G-protein coupled receptor kinase 5 gene and Parkinson's disease

2010 ◽  
Vol 156 (1) ◽  
pp. 104-107 ◽  
Author(s):  
Patrizia Tarantino ◽  
Elvira Valeria De Marco ◽  
Grazia Annesi ◽  
Francesca Emanuela Rocca ◽  
Ferdinanda Annesi ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
G Protein ◽  
Receptor Kinase ◽  
G Protein Coupled Receptor ◽  
G Protein Coupled
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