scholarly journals How palmitoylation affects trafficking and signalling of membrane receptors

2021 ◽  
Author(s):  
Maxime Jansen ◽  
Bruno Beaumelle
Keyword(s):  
Membrane Receptors

Asialo von Willebrand Factor Enhances Platelet Adhesion to Vessel Subendothelium

1988 ◽  
Vol 60 (01) ◽  
pp. 030-034 ◽  
Author(s):  
Eva Bastida ◽  
Juan Monteagudo ◽  
Antonio Ordinas ◽  
Luigi De Marco ◽  
Ricardo Castillo
Keyword(s):  
Von Willebrand Factor ◽  
Platelet Adhesion ◽  
Human Albumin ◽  
Membrane Receptors ◽  
Shear Rates ◽  
High Shear Rates ◽  
Platelet Deposition ◽  
Platelet Spreading ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryNative von Willebrand factor (N-vWF) binds to platelets activated by thrombin, ADP or ristocetin. Asialo vWF (As-vWF) induces platelet aggregation in absence of platelet activators. N-vWF mediates platelet adhesion to vessel subendothelium at high shear rates. We have investigated the role of As-vWF in supporting platelet deposition to rabbit vessel subendothelium at a shear rate of 2,000 sec-1, using the Baumgartner perfusion system. We have studied the effects of the addition of As-vWF (from 2 to 12 μg/ml) to perfusates consisting of washed red blood cells, 4% human albumin and washed platelets. Our results show a significant increase in platelet deposition on subendothelium (p <0.01) in perfusions to which As-vWF had been added. Blockage of the platelet glycoproteins Ib and IIb/IIIa (GPIb and GPIIb/IIIa) by specific monoclonal antibodies (LJIb1 and LJCP8, respectively) resulted in a decrease of platelet deposition in both types of perfusates prepared with N-vWF and As-vWF. Our results indicate that As-vWF enhances platelet deposition to vessel subendothelium under flow conditions. Furthermore, they suggest that this effect is mediated by the binding of As-vWF to platelet membrane receptors, which in turn, promote platelet spreading and adhesion to the subendothelium.

Mitochondria: the birth place, battle ground and the site of melatonin metabolism in cells

2019 ◽  
Vol 2 (1) ◽  
pp. 44-66 ◽  
Author(s):  
Dun-Xian Tan ◽  
Russel. J. Reiter
Keyword(s):  
Ischemia Reperfusion ◽  
Surface Membrane ◽  
Strong Association ◽  
Membrane Receptors ◽  
Melatonin Receptors ◽  
Metabolic Enzyme ◽  
Intermembrane Space ◽  
Antitumor Effects ◽  
The Matrix ◽  
Surprising Discovery

     It was a surprising discovery when mitochondria, as the power houses of cells, were also found to synthesize the potent mitochondrial targeted antioxidant, melatonin. The melatonin synthetic enzyme serotonin N-acetyltransferase (SNAT) was found in matrix and also in the intermembrane space of mitochondria. We hypothesize that the melatonin synthesis occurs in the matrix due to substrate (N-acetyl co-enzyme A) availability while the intermembrane space may serve as the recycling pool of SNAT to regulate the melatonin circadian rhythm. Another surprise was that the melatonin membrane receptors, including MT1 and MT2, were also present in mitochondria. The protective effects of melatonin against neuronal injury induced by brain ischemia/reperfusion were proven to be mainly mediated by mitochondrial melatonin receptors rather than the cell surface membrane receptors which is contrary to the classical principle. In addition, melatonin metabolic enzyme has also been identified in the mitochondria. This enzyme can convert melatonin to N-acetylserotonin to strengthen the antitumor effects of melatonin. Thus, mitochondria are the generator, battle ground and metabolic sites of melatonin. The biological significance of the strong association between mitochondria and melatonin should be intensively investigated. 

Mitochondria: the birth place, battle ground and the site of melatonin metabolism in cells

2019 ◽  
Vol 2 (1) ◽  
pp. 44-66 ◽  
Author(s):  
Dun-Xian Tan ◽  
Russel. J. Reiter
Keyword(s):  
Ischemia Reperfusion ◽  
Surface Membrane ◽  
Strong Association ◽  
Membrane Receptors ◽  
Melatonin Receptors ◽  
Metabolic Enzyme ◽  
Intermembrane Space ◽  
Antitumor Effects ◽  
The Matrix ◽  
Surprising Discovery

     It was a surprising discovery when mitochondria, as the power houses of cells, were also found to synthesize the potent mitochondrial targeted antioxidant, melatonin. The melatonin synthetic enzyme serotonin N-acetyltransferase (SNAT) was found in matrix and also in the intermembrane space of mitochondria. We hypothesize that the melatonin synthesis occurs in the matrix due to substrate (N-acetyl co-enzyme A) availability while the intermembrane space may serve as the recycling pool of SNAT to regulate the melatonin circadian rhythm. Another surprise was that the melatonin membrane receptors, including MT1 and MT2, were also present in mitochondria. The protective effects of melatonin against neuronal injury induced by brain ischemia/reperfusion were proven to be mainly mediated by mitochondrial melatonin receptors rather than the cell surface membrane receptors which is contrary to the classical principle. In addition, melatonin metabolic enzyme has also been identified in the mitochondria. This enzyme can convert melatonin to N-acetylserotonin to strengthen the antitumor effects of melatonin. Thus, mitochondria are the generator, battle ground and metabolic sites of melatonin. The biological significance of the strong association between mitochondria and melatonin should be intensively investigated. 

Therapeutic Potential of Agonists and Antagonists of A1, A2a, A2b and A3 Adenosine Receptors

2019 ◽  
Vol 25 (26) ◽  
pp. 2892-2905 ◽  
Author(s):  
Sumit Jamwal ◽  
Ashish Mittal ◽  
Puneet Kumar ◽  
Dana M. Alhayani ◽  
Amal Al-Aboudi
Keyword(s):  
Nervous System ◽  
Therapeutic Potential ◽  
The Body ◽  
Membrane Receptors ◽  
Physiological Importance ◽  
Physiological Processes ◽  
Central Nervous Systems ◽  
Energy Consuming ◽  
Metabolic Dysfunctions ◽  
G Protein Coupled

Adenosine is a naturally occurring nucleoside and an essential component of the energy production and utilization systems of the body. Adenosine is formed by the degradation of adenosine-triphosphate (ATP) during energy-consuming processes. Adenosine regulates numerous physiological processes through activation of four subtypes of G-protein coupled membrane receptors viz. A1, A2A, A2B and A3. Its physiological importance depends on the affinity of these receptors and the extracellular concentrations reached. ATP acts as a neurotransmitter in both peripheral and central nervous systems. In the peripheral nervous system, ATP is involved in chemical transmission in sensory and autonomic ganglia, whereas in central nervous system, ATP, released from synaptic terminals, induces fast excitatory postsynaptic currents. ATP provides the energetics for all muscle movements, heart beats, nerve signals and chemical reactions inside the body. Adenosine has been traditionally considered an inhibitor of neuronal activity and a regulator of cerebral blood flow. Since adenosine is neuroprotective against excitotoxic and metabolic dysfunctions observed in neurological and ocular diseases, the search for adenosinerelated drugs regulating adenosine transporters and receptors can be important for advancement of therapeutic strategies against these diseases. This review will summarize the therapeutic potential and recent SAR and pharmacology of adenosine and its receptor agonists and antagonists.

Phytosterols and Triterpenoids for Prevention and Treatment of Metabolic-related Liver Diseases and Hepatocellular Carcinoma

2019 ◽  
Vol 20 (3) ◽  
pp. 197-214 ◽  
Author(s):  
Isabel Sánchez-Crisóstomo ◽  
Eduardo Fernández-Martínez ◽  
Raquel Cariño-Cortés ◽  
Gabriel Betanzos-Cabrera ◽  
Rosa A. Bobadilla-Lugo
Keyword(s):  
Hepatocellular Carcinoma ◽  
Liver Disease ◽  
Anticancer Agents ◽  
Liver Diseases ◽  
Membrane Receptors ◽  
New Drugs ◽  
Sexual Hormones ◽  
Steroid Nucleus ◽  
Alcoholic Fatty Liver ◽  
Prevention And Treatment

Background: Liver ailments are among the leading causes of death; they originate from viral infections, chronic alcoholism, and autoimmune illnesses, which may chronically be precursors of cirrhosis; furthermore, metabolic syndrome may worsen those hepatopathies or cause Non-alcoholic Fatty Liver Disease (NAFLD) that may advance to non-alcoholic steatohepatitis (NASH). Cirrhosis is the late-stage liver disease and can proceed to hepatocellular carcinoma (HCC). Pharmacological treatment options for liver diseases, cirrhosis, and HCC, are limited, expensive, and not wholly effective. The use of medicinal herbs and functional foods is growing around the world as natural resources of bioactive compounds that would set the basis for the development of new drugs. Review and Conclusion: Plant and food-derived sterols and triterpenoids (TTP) possess antioxidant, metabolic-regulating, immunomodulatory, and anti-inflammatory activities, as well as they are recognized as anticancer agents, suggesting their application strongly as an alternative therapy in some chronic diseases. Thus, it is interesting to review current reports about them as hepatoprotective agents, but also because they structurally resemble cholesterol, sexual hormones, corticosteroids and bile acids due to the presence of the steroid nucleus, so they all can share pharmacological properties through activating nuclear and membrane receptors. Therefore, sterols and TTP appear as a feasible option for the prevention and treatment of chronic metabolic-related liver diseases, cirrhosis, and HCC.

Circulatory Cells as Tumortropic Carrier for Targetability Improvement

2020 ◽  
Vol 17 ◽  
Author(s):  
Dan Zou ◽  
Yajun Weng ◽  
Ping Yang
Keyword(s):  
Drug Delivery ◽  
Drug Delivery System ◽  
Delivery System ◽  
Cell Function ◽  
Incubation Temperature ◽  
Survival Rates ◽  
Controlled Drug Release ◽  
Membrane Receptors ◽  
Circulation Time ◽  
Targeting Efficiency

Background: How to achieve high targeting efficiency for drug delivery system is still one of the most important issues that tumor diagnosis and non-surgical therapies faced. Although nanoparticle-based drug delivery system made an amount of progress in extending circulation time, improving targetability, controlled drug release etc., yet the targeting efficiency remained low, and the development was limited to reduce side effects with overall survival rates unchanged or improved a little. Objective: This paper aims to review current researches on the cell-driven drug delivery systems, and discuss the potential obstacles and directions for cell-based cancer therapies and diagnosis. Methods: More than one hundred references were collected, and this paper focused on red blood cells, monocytes, macrophages, neutrophils, natural killer cells, T lymphocytes, mesenchymal stem cells, cell membrane, artificial cells and extracellular vesicles, then summarized 1) the utilizable properties, 2) balancing cargo-loading amounts and cell function, 3) cascade strategies for targetability improvement. Main findings: circulatory cells and their derivatives were featured by good biocompatibility, long circulation time in blood, unique chemo-migration and penetration ability. On the base of backpack and encapsulation approach, cargo loading amounts and cell function could be balanced through regulating membrane receptors, particle material/size/shape/structure and incubation temperature, etc. The cell-driven drug delivery system met most of the demands that nanoparticle-based delivery system failed to for effective tumortropic delivery. Conclusion: Despite of new challenges, cell-driven drug delivery system generally brought great benefits to and shed a light on for cancer therapy and diagnosis.

Targeting Membrane Receptors of Ovarian Cancer Cells for Therapy

2019 ◽  
Vol 19 (6) ◽  
pp. 449-467
Author(s):  
Zhiquan Liang ◽  
Ziwen Lu ◽  
Yafei Zhang ◽  
Dongsheng Shang ◽  
Ruyan Li ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cancer Cells ◽  
Receptor Binding ◽  
Cytoreductive Surgery ◽  
Therapeutic Strategies ◽  
Membrane Receptors ◽  
Ovarian Cancer Cells ◽  
Advanced Stage ◽  
Targeted Therapeutics ◽  
Cellular Processes

Ovarian cancer is a leading cause of death worldwide from gynecological malignancies, mainly because there are few early symptoms and the disease is generally diagnosed at an advanced stage. In addition, despite the effectiveness of cytoreductive surgery for ovarian cancer and the high response rates to chemotherapy, survival has improved little over the last 20 years. The management of patients with ovarian cancer also remains similar despite studies showing striking differences and heterogeneity among different subtypes. It is therefore clear that novel targeted therapeutics are urgently needed to improve clinical outcomes for ovarian cancer. To that end, several membrane receptors associated with pivotal cellular processes and often aberrantly overexpressed in ovarian cancer cells have emerged as potential targets for receptor-mediated therapeutic strategies including specific agents and multifunctional delivery systems based on ligand-receptor binding. This review focuses on the profiles and potentials of such strategies proposed for ovarian cancer treatment and imaging.

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