Elevated nuclear phosphatase and tensin homolog (PTEN) and altered insulin signaling in substantia nigral region of patients with Parkinson’s disease

2018 ◽  
Vol 666 ◽  
pp. 139-143 ◽  
Author(s):  
Sathiya Sekar ◽  
Changiz Taghibiglou
2020 ◽  
Vol 21 (5) ◽  
pp. 1772 ◽  
Author(s):  
Lucia Barazzuol ◽  
Flavia Giamogante ◽  
Marisa Brini ◽  
Tito Calì

Endoplasmic reticulum (ER)–mitochondria contact sites are critical structures for cellular function. They are implicated in a plethora of cellular processes, including Ca2+ signalling and mitophagy, the selective degradation of damaged mitochondria. Phosphatase and tensin homolog (PTEN)-induced kinase (PINK) and Parkin proteins, whose mutations are associated with familial forms of Parkinson’s disease, are two of the best characterized mitophagy players. They accumulate at ER–mitochondria contact sites and modulate organelles crosstalk. Alterations in ER–mitochondria tethering are a common hallmark of many neurodegenerative diseases including Parkinson’s disease. Here, we summarize the current knowledge on the involvement of PINK1 and Parkin at the ER–mitochondria contact sites and their role in the modulation of Ca2+ signalling and mitophagy.


Author(s):  
Szu-Yi Chou ◽  
Lung Chan ◽  
Chen-Chih Chung ◽  
Jing-Yuan Chiu ◽  
Yi-Chen Hsieh ◽  
...  

IntroductionDiabetes increases the risk of Parkinson’s disease (PD). The phosphorylation of type 1 insulin receptor substrate (IRS-1) determines the function of insulin signaling pathway. Extracellular vesicles (EVs) are emerging as biomarkers of human diseases. The present study investigated whether PD patients exert altered phosphorylation IRS-1 (p-IRS-1) inside the blood neuron-derived extracellular vesicles (NDEVs).Research Design and MethodsIn total, there were 94 patients with PD and 63 healthy controls recruited and their clinical manifestations were evaluated. Blood NDEVs were isolated using the immunoprecipitation method, and Western blot analysis was conducted to assess total IRS-1, p-IRS-1, and downstream substrates level in blood NDEVs. Statistical analysis was performed using SPSS 19.0, and p < 0.05 was considered significant.ResultsThe isolated blood EVs were validated according to the presence of CD63 and HSP70, nanoparticle tracking analysis and transmission electron microscopy. NDEVs were positive with neuronal markers. PD patients exerted significantly higher level of p-IRS-1S312 in blood NDEVs than controls. In addition, the p-IRS-1S312 levels in blood NDEVs was positively associated with the severity of tremor in PD patients after adjusting of age, sex, hemoglobin A1c, and body mass index (BMI).ConclusionPD patients exerted altered p-IRS-1S312 in the blood NDEVs, and also correlated with the severity of tremor. These findings suggested the association between dysfunctional insulin signaling pathway with PD. The role of altered p-IRS-1S312 in blood NDEVs as a segregating biomarker of PD required further cohort study to assess the association with the progression of PD.


2020 ◽  
Vol 319 (1) ◽  
pp. E110-E116 ◽  
Author(s):  
Brandyn D. Henriksbo ◽  
Akhilesh K. Tamrakar ◽  
Jobanjit S. Phulka ◽  
Nicole G. Barra ◽  
Jonathan D. Schertzer

Statins lower cholesterol and risk of cardiovascular disease. Statins can increase blood glucose and risk of new-onset diabetes. It is unclear why statins can have opposing effects on lipids versus glucose. Statins have cholesterol-independent pleiotropic effects that influence both insulin and glucose control. Statin lowering of isoprenoids required for protein prenylation promotes pancreatic β-cell dysfunction and adipose tissue insulin resistance. Protein prenylation influences immune function and statin-mediated adipose tissue insulin resistance involves the NLR family pyrin domain-containing 3 (NLRP3) inflammasome and IL-1β. However, the intracellular cues that statins engage to activate the NLRP3 inflammasome and those responsible for IL-1β-mediated insulin resistance in adipose tissue have not been identified. We hypothesized that stress kinases or components of the insulin signaling pathway mediated statin-induced insulin resistance. We tested the associations of p38, ERK, JNK, phosphatase, and tensin homolog (PTEN), and mTOR in statin-exposed adipose tissue from WT and IL-1β−/− mice. We found that statins increased phosphorylation of p38 in WT and IL-1β−/− mice. Statin activation of p38 upstream of IL-1β led to priming of this NLRP3 inflammasome effector in macrophages. We found that mTORC1 inhibition with low doses of rapamycin (2 or 20 nM) lowered macrophage priming of IL-1β mRNA and secretion of IL-1β caused by multiple statins. Rapamycin (20 nM) or the rapalog everolimus (20 nM) prevented atorvastatin-induced lowering of insulin-mediated phosphorylation of Akt in mouse adipose tissue. These results position p38 and mTOR as mediators of statin-induced insulin resistance in adipose tissue and highlight rapalogs as candidates to mitigate the insulin resistance and glycemic side effects of statins.


Open Biology ◽  
2011 ◽  
Vol 1 (3) ◽  
pp. 110012 ◽  
Author(s):  
Helen I. Woodroof ◽  
Joe H. Pogson ◽  
Mike Begley ◽  
Lewis C. Cantley ◽  
Maria Deak ◽  
...  

Missense mutations of the phosphatase and tensin homolog (PTEN)-induced kinase 1 (PINK1) gene cause autosomal-recessive Parkinson's disease. To date, little is known about the intrinsic catalytic properties of PINK1 since the human enzyme displays such low kinase activity in vitro . We have discovered that, in contrast to mammalian PINK1, insect orthologues of PINK1 we have investigated—namely Drosophila melanogaster (dPINK1) , Tribolium castaneum (TcPINK1) and Pediculus humanus corporis (PhcPINK1)—are active as judged by their ability to phosphorylate the generic substrate myelin basic protein. We have exploited the most active orthologue, TcPINK1, to assess its substrate specificity and elaborated a peptide substrate (PINKtide, KKWIpYRRSPRRR) that can be employed to quantify PINK1 kinase activity. Analysis of PINKtide variants reveal that PINK1 phosphorylates serine or threonine, but not tyrosine, and we show that PINK1 exhibits a preference for a proline at the +1 position relative to the phosphorylation site. We have also, for the first time, been able to investigate the effect of Parkinson's disease-associated PINK1 missense mutations, and found that nearly all those located within the kinase domain, as well as the C-terminal non-catalytic region, markedly suppress kinase activity. This emphasizes the crucial importance of PINK1 kinase activity in preventing the development of Parkinson's disease. Our findings will aid future studies aimed at understanding how the activity of PINK1 is regulated and the identification of physiological substrates.


2021 ◽  
Author(s):  
Marina Galdino da Rocha Pitta ◽  
Jordy Silva de Carvalho ◽  
Luzilene Pereira de Lima ◽  
Ivan da Rocha Pitta

Background: Parkinson’s disease (PD) is a neurological disorder that affects movement, mainly due to damage and degeneration of the nigrostriatal dopaminergic pathway. The diagnosis is made through a clinical neurological analysis where motor characteristics are considered. There is still no cure, and treatment strategies are focused on symptoms control. Cell replacement therapies emerge as an alternative. Objective: This review focused on current techniques of induced pluripotent stem cells (iPSCs). Methods: The search terms used were: “Parkinson’s Disease”, “Stem cells” and “iPSC”. Open articles written in English, from 2016-21 were selected in the Pubmed database, 10 publications were identified. Results: With the modernization of iPSC, it was possible to reprogram pluripotent human somatic cells and generate dopaminergic neurons and individual-specific glial cells. To understand the molecular basis, cell and animal models of neurons and organelles are currently being employed. Organoids are derived from stem cells in a three-dimensional matrix, such as matrigel or hydrogels derived from animals. The neuronal models are: α-synuclein (SNCA), leucine-rich repeat kinase2 (LRRK2), PARK2, putative kinase1 induced by phosphatase and tensin homolog (PINK1), DJ-1. Both models offer opportunities to investigate pathogenic mechanisms of PD and test compounds on human neurons. Conclusions: Cell replacement therapy is promising and has great capacity for the treatment of neurodegenerative diseases. Studies using iPSC neuron and PD organoid modeling is highly valuable in elucidating relevants neuronal pathways and therapeutic targets, moreover providing important models for testing future therapies.


2010 ◽  
Vol 24 (S1) ◽  
Author(s):  
Jill Kathleen Morris ◽  
A. Raquel Esteves ◽  
Gregory L. Bomhoff ◽  
Russell H. Swerdlow ◽  
John A. Stanford ◽  
...  

2020 ◽  
Vol 19 (3) ◽  
pp. 174-183
Author(s):  
Subrat Kumar Bhattamisra ◽  
Lee Yuen Shin ◽  
Hanis Izzati Binti Mohd Saad ◽  
Vikram Rao ◽  
Mayuren Candasamy ◽  
...  

The interlink between diabetes mellitus and neurodegenerative diseases such as Alzheimer’s Disease (AD) and Parkinson’s Disease (PD) has been identified by several researchers. Patients with Type-2 Diabetes Mellitus (T2DM) are found to be affected with cognitive impairments leading to learning and memory deficit, while patients with Type-1 Diabetes Mellitus (T1DM) showed less severe levels of these impairments in the brain. This review aimed to discuss the connection between insulin with the pathophysiology of neurodegenerative diseases (AD and PD) and the current therapeutic approached mediated through insulin for management of neurodegenerative diseases. An extensive literature search was conducted using keywords “insulin”; “insulin resistance”; “Alzheimer’s disease”; “Parkinson’s disease” in public domains of Google scholar, PubMed, and ScienceDirect. Selected articles were used to construct this review. Studies have shown that impaired insulin signaling contributes to the accumulation of amyloid-β, neurofibrillary tangles, tau proteins and α-synuclein in the brain. Whereas, improvement in insulin signaling slows down the progression of cognitive decline. Various therapeutic approaches for altering the insulin function in the brain have been researched. Besides intranasal insulin, other therapeutics like PPAR-γ agonists, neurotrophins, stem cell therapy and insulin-like growth factor-1 are under investigation. Research has shown that insulin insensitivity in T2DM leads to neurodegeneration through mechanisms involving a variety of extracellular, membrane receptor, and intracellular signaling pathway disruptions. Some therapeutics, such as intranasal administration of insulin and neuroactive substances have shown promise but face problems related to genetic background, accessibility to the brain, and invasiveness of the procedures.


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