scholarly journals ATP acting through P2Y receptors causes activation of podocyte TRPC6 channels: role of podocin and reactive oxygen species

2014 ◽  
Vol 306 (9) ◽  
pp. F1088-F1097 ◽  
Author(s):  
Hila Roshanravan ◽  
Stuart E. Dryer

Extracellular ATP may contribute to Ca2+ signaling in podocytes during tubuloglomerular feedback (TGF) and possibly as a result of local tissue damage. TRPC6 channels are Ca2+-permeable cationic channels that have been implicated in the pathophysiology of podocyte diseases. Here we show using whole cell recordings that ATP evokes robust activation of TRPC6 channels in mouse podocyte cell lines and in rat podocytes attached to glomerular capillaries in ex vivo glomerular explants. The EC50 for ATP is ∼10 μM and is maximal at 100 μM, and currents were blocked by the P2 antagonist suramin. In terms of maximal currents that can be evoked, ATP is the strongest activator of podocyte TRPC6 that we have characterized to date. Smaller currents were observed in response to ADP, UTP, and UDP. ATP-evoked currents in podocytes were abolished by TRPC6 knockdown and by pretreatment with 10 μM SKF-96365 or 50 μM La3+. ATP effects were also abolished by inhibiting G protein signaling and by the PLC/PLA2 inhibitor D-609. ATP effects on TRPC6 were also suppressed by knockdown of the slit diaphragm scaffolding protein podocin, and also by tempol, a membrane-permeable quencher of reactive oxygen species. Modulation of podocyte TRPC6 channels, especially in foot processes, could provide a mechanism for regulation of glomerular function by extracellular nucleotides, possibly leading to changes in permeation through slit diaphragms. These results raise the possibility that sustained ATP signaling could contribute to foot process effacement, Ca2+-dependent changes in gene expression, and/or detachment of podocytes.

2021 ◽  
Vol 2 (1) ◽  
pp. 100332
Author(s):  
Chirag Vasavda ◽  
Solomon H. Snyder ◽  
Bindu D. Paul

Nanomedicine ◽  
2021 ◽  
Author(s):  
Muktashree Saha ◽  
Anil P  Bidkar ◽  
Siddhartha S  Ghosh

Aim: The primary aim of this study was to develop biomimetic nanocarriers for specific homologous targeting of the anticancer drugs ammonium pyrrolidine dithiocarbamate (PDTC) and doxorubicin. Methods: Membranous nanovesicles were synthesized from a breast cancer cell line (MCF7) by syringe extrusion process and were loaded with PDTC and doxorubicin. Besides their abilities for self-homing, the drug loaded nanovesicles showed anti-cell proliferative effects via the generation of reactive oxygen species. Results: The nanovesicles demonstrated efficient internalization via homologous targeting. Delivery of PDTC showed a higher killing effect for homologous cell targeting than other cell types. Experimental results demonstrated increased antiproliferative potency of PDTC, which induced apoptosis via reactive oxygen species generation. Conclusion: The developed membrane-derived nanocarrier is an attractive biocompatible system for ex vivo targeted drug delivery.


Antioxidants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1155
Author(s):  
Olga Witkowska-Piłaszewicz ◽  
Rafał Pingwara ◽  
Anna Winnicka

Physical activity has an influence on a variety of processes in an athlete’s organism including the immune system. Unfortunately, there is a lack of studies regarding racehorse immune cells, especially when the horse model is compared to human exercise physiology. The aim of the study was to determine changes in immune cell proliferation, lymphocyte populations, and monocyte functionality in trained and untrained racehorses after exercise. In this study, field data were collected. The cells from 28 racehorses (14 untrained and 14 well-trained) were collected before and after exercise (800 m at a speed of about 800 m/min) and cultured for 4 days. The expression of CD4, CD8, FoxP3, CD14, MHCII, and CD5 in PBMC, and reactive oxygen species (ROS) production, as well as cell proliferation, were evaluated by flow cytometry. In addition, IL-1β, IL-4, IL-6, IL-10, IL-17, INF-γ, and TNF-α concentrations were evaluated by ELISA. The creation of an anti-inflammatory environment in well-trained horses was confirmed. In contrast, a pro-inflammatory reaction occurred in untrained horses after training. In conclusion, an anti-inflammatory state occurs in well-trained racehorses, which is an adaptational reaction to an increased workload during training.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Zariyantey Abdul Hamid ◽  
Winnie Hii Lin Lin ◽  
Basma Jibril Abdalla ◽  
Ong Bee Yuen ◽  
Elda Surhaida Latif ◽  
...  

Hematopoietic stem cells- (HSCs-) based therapy requiresex vivoexpansion of HSCs prior to therapeutic use. However,ex vivoculture was reported to promote excessive production of reactive oxygen species (ROS), exposing HSCs to oxidative damage. Efforts to overcome this limitation include the use of antioxidants. In this study, the role ofHibiscus sabdariffaL. (Roselle) in maintenance of cultured murine bone marrow-derived HSCs was investigated. Aqueous extract of Roselle was added at varying concentrations (0–1000 ng/mL) for 24 hours to the freshly isolated murine bone marrow cells (BMCs) cultures. Effects of Roselle on cell viability, reactive oxygen species (ROS) production, glutathione (GSH) level, superoxide dismutase (SOD) activity, and DNA damage were investigated. Roselle enhanced the survival(P<0.05)of BMCs at 500 and 1000 ng/mL, increased survival of Sca-1+cells (HSCs) at 500 ng/mL, and maintained HSCs phenotype as shown from nonremarkable changes of surface marker antigen (Sca-1) expression in all experimental groups. Roselle increased(P<0.05)the GSH level and SOD activity but the level of reactive oxygen species (ROS) was unaffected. Moreover, Roselle showed significant cellular genoprotective potency against H2O2-induced DNA damage. Conclusively, Roselle shows novel property as potential supplement and genoprotectant against oxidative damage to cultured HSCs.


2011 ◽  
Vol 23 (4) ◽  
pp. 561 ◽  
Author(s):  
Nathan T. Bain ◽  
Pavneesh Madan ◽  
Dean H. Betts

In vitro embryo production (IVP) suffers from excessive developmental failure. Its inefficiency is linked, in part, to reactive oxygen species (ROS) brought on by high ex vivo oxygen (O2) tensions. To further delineate the effects of ROS on IVP, the intracellular ROS levels of early bovine embryos were modulated by: (1) varying O2 tension; (2) exogenous H2O2 treatment; and (3) antioxidant supplementation. Although O2 tension did not significantly affect blastocyst frequencies (P > 0.05), 20% O2 accelerated the rate of first cleavage division and significantly decreased and increased the proportion of permanently arrested 2- to 4-cell embryos and apoptotic 9- to 16-cell embryos, respectively, compared with embryos cultured in 5% O2 tension. Treatment with H2O2, when applied separately to oocytes, zygotes, 2- to 4-cell embryos or 9- to 16-cell embryos, resulted in a significant (P < 0.05) dose-dependent decrease in blastocyst development in conjunction with a corresponding increase in the induction of either permanent embryo arrest or apoptosis in a stage-dependent manner. Polyethylene glycol–catalase supplementation reduced ROS-induced embryo arrest and/or death, resulting in a significant (P < 0.05) increase in blastocyst frequencies under high O2 culture conditions. Together, these results indicate that intracellular ROS may be signalling molecules that, outside an optimal range, result in various developmentally regulated modes of embryo demise.


2014 ◽  
Vol 38 (6) ◽  
pp. 1168-1177 ◽  
Author(s):  
José Carlos Rebuglio Vellosa ◽  
Luis Octávio Regasini ◽  
Caroline Belló ◽  
Josiane Aparecida Schemberger ◽  
Najeh Maissar Khalil ◽  
...  

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