scholarly journals Inhibition of phosphatidylinositol 3-kinase modifies boar sperm motion parameters

Reproduction ◽  
2005 ◽  
Vol 129 (3) ◽  
pp. 283-289 ◽  
Author(s):  
I M Aparicio ◽  
M C Gil ◽  
M Garcia-Herreros ◽  
F J Peña ◽  
L J Garcia-Marin
Keyword(s):  
Sperm Motility ◽  
Sperm Quality ◽  
Phosphatidylinositol 3 Kinase ◽  
Sperm Analysis ◽  
Camp Analog ◽  
Boar Sperm ◽  
Motion Parameters ◽  
Sperm Motion ◽  
Phosphatidylinositol 3

Motility is the most widely used indicator of sperm quality. Besides modulation by the cAMP pathway little is known regarding the intracellular pathways that regulate boar sperm motility. Recently the role of phosphatidylinositol 3-kinase (PI3-K) in the regulation of human sperm motility has been described. Therefore, the aim of this study was to investigate the role of PI3-K in boar sperm kinematics by using the specific PI3-K inhibitor, LY294002. Boar sperm was incubated up to 1 h in non-capacitating medium in the presence or absence of the cAMP analog, 8Br-cAMP or the PI3-K inhibitor, LY294002 or both. Boar sperm incubated in capacitating medium was treated in the presence or absence of LY294002. First, we have clearly identified that PI3-K is present in whole lysates of boar spermatozoa. Inhibition of PI3-K significantly increased boar sperm straight-line velocity, circular velocity and average velocity without an effect on the percentage of progressively motile spermatozoa in both media. Inhibition of PI3-K induced the same effects on boar sperm velocities as activation of the cAMP/protein kinase A (PKA) pathway and treatment with the PI3-K inhibitor, LY294002 had neither summatory nor synergic effects on boar sperm motion parameters when treated simultaneously with the cAMP analog 8Br-cAMP. Our data suggest that PI3-K plays a negative role, regulating boar sperm motion parameters through a possible inhibition of the cAMP/PKA activating pathway, and since some Computer Aided Sperm Analysis (CASA)-derived parameters have been related to field fertility our results point to the possibility of modulating sperm motile quality by modifying the PI3-K cellular pathway.

scholarly journals Role of phosphatidylinositol 3-kinase in oxidative stress-induced disruption of tight junctions. Vol. 278 (2003) 49239-49245

2004 ◽  
Vol 279 (7) ◽  
pp. 6204
Author(s):  
Parimal Sheth ◽  
Shyamali Basuroy ◽  
Chunying Li ◽  
Anjaparavanda P. Naren ◽  
Radhakrishna K. Rao
Keyword(s):  
Oxidative Stress ◽  
Tight Junctions ◽  
Phosphatidylinositol 3 Kinase ◽  
Phosphatidylinositol 3

scholarly journals Novel Role of Phosphatidylinositol 3-Kinase in CD28-mediated Costimulation

2000 ◽  
Vol 276 (12) ◽  
pp. 9003-9008 ◽  
Author(s):  
Yohsuke Harada ◽  
Eri Tanabe ◽  
Ryosuke Watanabe ◽  
Bonnie D. Weiss ◽  
Akira Matsumoto ◽  
...  
Keyword(s):  
Phosphatidylinositol 3 Kinase ◽  
Phosphatidylinositol 3

scholarly journals cAMP-stimulated Na+ transport in H441 distal lung epithelial cells: role of PKA, phosphatidylinositol 3-kinase, and sgk1

2004 ◽  
Vol 287 (4) ◽  
pp. L843-L851 ◽  
Author(s):  
Christie P. Thomas ◽  
Jason R. Campbell ◽  
Patrick J. Wright ◽  
Russell F. Husted
Keyword(s):  
Apical Cell ◽  
P38 Map Kinase ◽  
Lung Epithelial Cells ◽  
Epithelial Cell Line ◽  
Phosphatidylinositol 3 Kinase ◽  
Transport Pathway ◽  
Early Effect ◽  
Sustained Effect ◽  
Phosphatidylinositol 3

H441 cells, a bronchiolar epithelial cell line, develop a cAMP-regulated benzamil-sensitive Na+ transport pathway on permeable supports (Itani OA, Auerbach SD, Husted RF, Volk KA, Ageloff S, Knepper MA, Stokes JB, Thomas CP. Am J Physiol Lung Cell Mol Physiol 282: L631–L641, 2002). To understand the molecular basis for the stimulation of Na+ transport, we delineated the role of specific intracellular pathways and examined the effect of cAMP on αβγ-epithelial Na+ channel (ENaC) and sgk1 expression. Na+ transport increases within 5 min of cAMP stimulation and is sustained for >24 h. The sustained effect of cAMP on Na+ transport is abolished by LY-294002, an inhibitor of phosphatidylinositol 3-kinase, by H89, an inhibitor of PKA, or by SB-202190, an inhibitor of p38 MAP kinase. The sustained effect of cAMP was associated with increases in α-ENaC mRNA and protein but without a detectable increase in βγ-ENaC and sgk1. The early effect of cAMP on Na+ transport is brefeldin sensitive and is mediated via PKA. These results are consistent with a model where the early effect of cAMP is to increase trafficking of Na+ channels to the apical cell surface whereas the sustained effect requires the synthesis of α-ENaC.

scholarly journals PI(4,5)P2 controls slit diaphragm formation and endocytosis in Drosophila nephrocytes

2021 ◽  
Author(s):  
Max Gass ◽  
Sarah Borkowsky ◽  
Marie-Luise Lotz ◽  
Rita Schroeter ◽  
Pavel Nedvetsky ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Model System ◽  
Dominant Negative ◽  
Slit Diaphragm ◽  
Phosphatidylinositol 3 Kinase ◽  
Ectopic Activation ◽  
Phosphatidylinositol 4 ◽  
Asymmetrically Distributed ◽  
Phosphatidylinositol 3

Drosophila nephrocytes are an emerging model system for mammalian podocytes and podocyte-associated diseases. Like podocytes, nephrocytes exhibit characteristics of epithelial cells, but the role of phospholipids in polarization of these cells is yet unclear. In epithelia phosphatidylinositol(4,5)bisphosphate (PI(4,5)P2) and phosphatidylinositol(3,4,5)-trisphosphate (PI(3,4,5)P3) are asymmetrically distributed in the plasma membrane and determine apical-basal polarity. Here we demonstrate that both phospholipids are present in the plasma membrane of nephrocytes, but only PI(4,5)P2 accumulates at slit diaphragms. Knockdown of Skittles, a phosphatidylinositol(4)phosphate 5-kinase, which produces PI(4,5)P2, abolished slit diaphragm formation and led to strongly reduced endocytosis. Notably, reduction in PI(3,4,5)P3 by overexpression of PTEN or expression of a dominant-negative phosphatidylinositol-3-Kinase did not affect nephrocyte function, whereas enhanced formation of PI(3,4,5)P3 by constitutively active phosphatidylinositol-3-Kinase resulted in strong slit diaphragm and endocytosis defects by ectopic activation of the Akt/mTOR pathway. Thus, PI(4,5)P2 but not PI(3,4,5)P3 is essential for slit diaphragm formation and nephrocyte function. However, PI(3,4,5)P3 has to be tightly controlled to ensure nephrocyte development.

Phosphatidylinositol 3-Kinase and Prostaglandylinositol Cyclic Phosphate (Cyclic PIP), a Mediator of Insulin Action, in the Signal Transduction of Insulin

2000 ◽  
Vol 381 (11) ◽  
pp. 1139-1141 ◽  
Author(s):  
A. Gypakis ◽  
H.K. Wasner
Keyword(s):  
Insulin Receptor ◽  
Glucose Transport ◽  
Functional Role ◽  
Specific Inhibitor ◽  
Insulin Receptor Substrate ◽  
Phosphatidylinositol 3 Kinase ◽  
Downstream Signaling ◽  
Cyclic Phosphate ◽  
Phosphatidylinositol 3

Abstract It has been suggested that downstream signaling from the insulin receptor to the level of the protein kinases and protein phosphatases is accomplished by prostaglandylinositol cyclic phosphate (cyclic PIP), a proposed second messenger of insulin. However, evidence points also to both phosphatidylinositol 3-kinase, which binds to the tyrosine phosphorylated insulin receptor substrate-1, and the Ras complex in insulin's downstream signaling. We have examined whether a correlation exists between these various observations. It was found that wortmannin, a specific inhibitor of phosphatidylinositol 3-kinase, prevented insulin-induced, as well as cyclic PIP-induced activation of glucose transport, indicating that PI 3-kinase action on glucose transport involves downstream signaling of both insulin and cyclic PIP. Wortmannin has no effect on cyclic PIP synthase activity nor on the substrate production for cyclic PIP synthesis either, indicating that the functional role of PI 3-kinase is exclusively downstream of cyclic PIP.

Role of Phosphatidylinositol-3 Kinase Pathway in NMDA Preconditioning: Different Mechanisms for Seizures and Hippocampal Neuronal Degeneration Induced by Quinolinic Acid

2018 ◽  
Vol 34 (3) ◽  
pp. 452-462 ◽  
Author(s):  
Leandra C. Constantino ◽  
Luisa B. Binder ◽  
Samuel Vandresen-Filho ◽  
Giordano G. Viola ◽  
Fabiana K. Ludka ◽  
...  
Keyword(s):  
Quinolinic Acid ◽  
Neuronal Degeneration ◽  
Phosphatidylinositol 3 Kinase ◽  
Nmda Preconditioning ◽  
Kinase Pathway ◽  
Phosphatidylinositol 3

scholarly journals Antioxidant Effect of a Polyphenol-Rich Murtilla (Ugni molinae Turcz.) Extract and Its Effect on the Regulation of Metabolism in Refrigerated Boar Sperm

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Ignacio Jofré ◽  
Magdalena Cuevas ◽  
Leticia Signori de Castro ◽  
João Diego de Agostini Losano ◽  
Mariana Andrade Torres ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Sperm Motility ◽  
Sperm Quality ◽  
Membrane Damage ◽  
Antioxidant Effect ◽  
Boar Sperm ◽  
Fertilization Capacity ◽  
Ugni Molinae

The production of reactive oxygen species (ROS) in boar spermatozoa increases in refrigeration; this can have an impact on sperm quality and fertilization capacity. We evaluated the effect of polyphenol-rich aqueous extract of murtilla (Ugni molinae Turcz) on boar sperm stored at 17°C in order to reduce oxidative stress and improve sperm quality in the long term. Five experiments were performed: first, characterization of the polyphenol content from five genotypes of murtilla; second, determination of the genotype with the best antioxidant effect (MT-Ex); third, the antioxidant capacity on O2- and lipid peroxidation; fourth, the influence of MT-Ex on motility, calcium movement, cAMP, and metabolic parameters; and fifth, analysis of long-term refrigeration. The average phenolic content was 344 ppm; gallic acid, catechin, quercetin, myricetin, and kaempferol were detected. All extracts evaluated presented a concentration-dependent antioxidant effect. MT-Ex reduces intracellular O2-/peroxides but low lipid peroxidation. MT-Ex in nonstimulated ROS conditions reduces sperm motility, mitochondrial membrane potential, cAMP, and ATP, but the succinate dehydrogenase activity remained normal; also, we observed a reduction in calcium movement in in vitro sperm capacitation. The long-term analyses showed that MT-Ex improved sperm motility decay and reduced membrane damage and ROS at 168 h. Based on this study, we propose MT-Ex as a supplement in semen extenders.

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