You searched for +publisher:"Temple University" +contributor:("Daniel, James L.")
.
Showing records 1 – 6 of
6 total matches.
No search limiters apply to these results.

Temple University
1.
Chari, Ramya.
Molecular Mechanisms Underlying Differential Regulation of Platelet Dense Granule Secretion by Protein Kinase C delta.
Degree: PhD, 2010, Temple University
URL: http://digital.library.temple.edu/u?/p245801coll10,77283
► Physiology
Protein Kinase C delta (PKCδ) is expressed in platelets and activated downstream of protease-activated receptors (PAR)s and glycoprotein VI (GPVI) receptors. We evaluated the…
(more)
▼ Physiology
Protein Kinase C delta (PKCδ) is expressed in platelets and activated downstream of
protease-activated receptors (PAR)s and glycoprotein VI (GPVI) receptors. We evaluated
the role of PKCδ in platelets using two approaches - pharmacological and molecular
genetic approach. In human platelets pretreated with isoform selective antagonistic
RACK peptide (δV1-1)TAT, and in the murine platelets lacking PKCδ, PAR4-mediated
dense granule secretion was inhibited, whereas GPVI-mediated dense granule secretion
was potentiated. These effects were statistically significant in the absence and presence of
thromboxane A2 (TXA2). Furthermore, TXA2 generation was differentially regulated by
PKCδ. However, PKCδ had a small effect on platelet P-selectin expression. Calcium- and
PKC-dependent pathways independently activate fibrinogen receptor in platelets. When
calcium pathways are blocked by dimethyl-BAPTA, AYPGKF-induced aggregation in
PKCδ null mouse platelets and in human platelets pretreated with (δV1-1)TAT, was
inhibited. In a FeCl3-induced injury in vivo thrombosis model, PKCδ-/- mice occluded
similar to their wild-type littermates. Hence, we conclude that PKCδ differentially
regulates platelet functional responses such as dense granule secretion and TXA2
generation downstream of PARs and GPVI receptors, but PKCδ deficiency does not
affect the thrombus formation in vivo.
We further investigated the mechanism of such differential regulation of dense granule
release by PKCδ in platelets. SH2 domain-containing Inositol Phosphatase (SHIP)-1 is
phosphorylated on Y1020, a marker for its activation, upon stimulation of human
platelets with PAR agonists, SFLLRN and AYPGKF, or GPVI agonist, convulxin. GPVImediated
SHIP-1 phosphorylation occurred rapidly at 15 sec whereas PAR-mediated
phosphorylation was delayed, occurring at 1 min. Lyn and SHIP-1, but not SHIP-2 or
Shc, preferentially associated with PKCδ upon stimulation of platelets with a GPVI
agonists, but not with a PAR agonist. In PKCδ null murine platelets, convulxin-induced
SHIP-1 phosphorylation was inhibited, suggesting that PKCδ regulates the
phosphorylation of SHIP-1. Furthermore, in Lyn null murine platelets, GPVI-mediated
phosphorylations on Y-1020 of SHIP-1, Y311 and Y155 of PKCδ were inhibited. In
murine platelets lacking Lyn, or SHIP-1, GPVI-mediated dense granule secretions were
potentiated, whereas PAR-mediated dense granule secretions were inhibited.
Phosphorylated SHIP-1 associated with phosphorylated-Y155 PKCδ peptide. Therefore,
we conclude that Lyn-mediated phosphorylations of PKCδ and SHIP-1 and their
associations negatively regulate GPVI-mediated dense granule secretion in platelets.
Temple University – Theses
Advisors/Committee Members: Kunapuli, Satya P., Driska, Steven Paul, Eguchi, Satoru, Daniel, James L., Naik, Ulhas P..
Subjects/Keywords: Biology, Physiology; Biology, Cell; Biology, Molecular; Dense Granule Secretion; Phosphorylation; Platelets; Protein Kinase C; Signaling; Thrombosis
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share





❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Chari, R. (2010). Molecular Mechanisms Underlying Differential Regulation of Platelet Dense Granule Secretion by Protein Kinase C delta. (Doctoral Dissertation). Temple University. Retrieved from http://digital.library.temple.edu/u?/p245801coll10,77283
Chicago Manual of Style (16th Edition):
Chari, Ramya. “Molecular Mechanisms Underlying Differential Regulation of Platelet Dense Granule Secretion by Protein Kinase C delta.” 2010. Doctoral Dissertation, Temple University. Accessed April 15, 2021.
http://digital.library.temple.edu/u?/p245801coll10,77283.
MLA Handbook (7th Edition):
Chari, Ramya. “Molecular Mechanisms Underlying Differential Regulation of Platelet Dense Granule Secretion by Protein Kinase C delta.” 2010. Web. 15 Apr 2021.
Vancouver:
Chari R. Molecular Mechanisms Underlying Differential Regulation of Platelet Dense Granule Secretion by Protein Kinase C delta. [Internet] [Doctoral dissertation]. Temple University; 2010. [cited 2021 Apr 15].
Available from: http://digital.library.temple.edu/u?/p245801coll10,77283.
Council of Science Editors:
Chari R. Molecular Mechanisms Underlying Differential Regulation of Platelet Dense Granule Secretion by Protein Kinase C delta. [Doctoral Dissertation]. Temple University; 2010. Available from: http://digital.library.temple.edu/u?/p245801coll10,77283

Temple University
2.
Thomas, Dafydd Huw.
Regulation of Syk activity in GPVI-mediated platelet activation.
Degree: PhD, 2010, Temple University
URL: http://digital.library.temple.edu/u?/p245801coll10,92028
► Pharmacology
Activation of platelets is essential for hemostasis. Following damage to the vascular endothelium collagen is exposed, to which platelets stably adhere. After adhesion on…
(more)
▼ Pharmacology
Activation of platelets is essential for hemostasis. Following damage to the vascular
endothelium collagen is exposed, to which platelets stably adhere. After adhesion on
collagen, a signaling cascade is initiated, mediated by Glycoprotein VI (GPVI), which
results in platelet activation. A major signaling protein in GPVI signaling is Spleen
tyrosine kinase (Syk). It undergoes phosphorylation and activation following GPVI
stimulation. Syk's central role in this physiological process suggests regulation of its
activity is required to maintain the platelets response to collagen within physiological
limits. The regulation of Syk activation is the focus of this work.
Previously published reports implicate the phosphatases SHP-1, SHP-2 and TULA-2 in
the negative regulation of Syk. Therefore, we tested these phosphatases possible role in
platelets. We show that SHP-1 can dephosphorylate Syk in vitro, but is unable to bind
Syk. Also, Syk is hypophosphorylated in GPVI-stimulated SHP-1 deficient platelets and
platelet functional responses are minimally affected compared to wild-type platelets.
SHP-2 is unable to bind Syk and Syk is not a good substrate for SHP-2 in vitro. TULA-2
dephosphorylated Syk in vitro and associated with Syk in platelets. In TULA-2 deficient
platelets, Syk and PLCγ2 were hyperphosphorylated compared to wild-type platelets.
Deletion of TULA-2 resulted in enhanced GPVI-dependent platelet functional responses
and a prothrombotic phenotype.
c-Cbl has been shown to be a negative regulator of GPVI signaling, possibly by
regulating Syk phosphorylation. Thus, SHP-1, SHP-2 and TULA-2’s role in c-Cbl
regulation of GPVI was also investigated. We show that TULA-2 is able to bind c-Cbl in
platelets. SHP-1 and SHP-2 do not. Furthermore, we show a striking similarity between
the phenotype of TULA-2 and c-Cbl deficient platelets. However, in vitro binding studies
show TULA-2 is able to bind Syk independently of c-Cbl. Thus, the exact role of c-Cbl
in regulating Syk dephosphorylation is unclear.
In conclusion, we show SHP-1 and SHP-2 are probably not involved in the negative
regulation of Syk. However, TULA-2 is the major phosphatase responsible for the
negative regulation of Syk in GPVI signaling. This serves to negatively regulate GPVI-mediated
platelet function and prevent uncontrolled platelet activation that could lead to
thrombosis.
Temple University – Theses
Advisors/Committee Members: Daniel, James L., Ashby, Barrie, Kunapuli, Satya P., Tsygankov, Alexander, Wang, Hong, Bergmeier, Wolfgang.
Subjects/Keywords: Health Sciences, Pharmacology; Collagen; GPVI; Phosphatase; Platelets; Syk; TULA
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share





❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Thomas, D. H. (2010). Regulation of Syk activity in GPVI-mediated platelet activation. (Doctoral Dissertation). Temple University. Retrieved from http://digital.library.temple.edu/u?/p245801coll10,92028
Chicago Manual of Style (16th Edition):
Thomas, Dafydd Huw. “Regulation of Syk activity in GPVI-mediated platelet activation.” 2010. Doctoral Dissertation, Temple University. Accessed April 15, 2021.
http://digital.library.temple.edu/u?/p245801coll10,92028.
MLA Handbook (7th Edition):
Thomas, Dafydd Huw. “Regulation of Syk activity in GPVI-mediated platelet activation.” 2010. Web. 15 Apr 2021.
Vancouver:
Thomas DH. Regulation of Syk activity in GPVI-mediated platelet activation. [Internet] [Doctoral dissertation]. Temple University; 2010. [cited 2021 Apr 15].
Available from: http://digital.library.temple.edu/u?/p245801coll10,92028.
Council of Science Editors:
Thomas DH. Regulation of Syk activity in GPVI-mediated platelet activation. [Doctoral Dissertation]. Temple University; 2010. Available from: http://digital.library.temple.edu/u?/p245801coll10,92028

Temple University
3.
Bynagari, Yamini Saraswathy.
Molecular Physiology of Novel Class of Protein Kinase C isoforms in Platelets.
Degree: PhD, 2010, Temple University
URL: http://digital.library.temple.edu/u?/p245801coll10,103230
► Molecular and Cellular Physiology
Platelets are primary components of hemostasis. However, incongruous activation of platelets lead to thrombosis, which result in multiple cardio-vascular and cerebrovascular…
(more)
▼ Molecular and Cellular Physiology
Platelets are primary components of hemostasis. However, incongruous activation of
platelets lead to thrombosis, which result in multiple cardio-vascular and cerebrovascular
complications. Thus, platelet activation is tightly regulated. Molecular
components that aid in activation of platelets have been extensively studied. However,
molecular pathways that negatively regulate platelet activation and prevent accidental
activation of platelets are poorly understood. In this study we investigated the molecular
mechanisms that negatively regulate platelet activation.
Protein Kinase C isforms (PKCs) are serine threonine kinases that regulate various
platelet functional responses leading to hemostasis. Positive regulatory role of PKCs
towards platelet aggregation and secretion has been extensively studied. However, we
have recently demonstrated that PKCs negatively regulate ADP- induced thromboxane
generation. The PKC isoforms and mechanism involved in this process have not been
known. Thus, in this study we investigated the mechanism by which PKCs negatively
regulate ADP-induced thromboxane generation and identified PKC isoforms that regulate
thromboxane generation.
Thromboxane generation in platelets is a multi-step process beginning with cPLA2
activation. cPLA2 activation is the rate limiting step in the process of thromboxane
generation. Furthermore, cPLA2 activation is regulated by ERK and calcium in various
cell systems including platelets. PKC inhibition potentiated both cPLA2 and ERK
activation, suggesting that PKCs negatively regulate thromboxane generation by
regulating ERK activation, which in turn regulates cPLA2 activation. Furthermore, we
have also shown that PKCs negatively regulate ADP-induced calcium mobilization. ADP
activates platelets via P2Y1 and P2Y12 receptors. P2Y12 receptor-mediated signaling is
shown to positively regulate P2Y1-mediated calcium mobilization in platelets.
Furthermore, PKCs are shown to negatively regulate P2Y12 receptor desensitization in
platelets. Thus, we investigated if PKCs regulate calcium mobilization indirectly by
regulating P2Y12 receptor function. However, PKCs regulate calcium mobilization
independent of P2Y12 receptor signaling. In summary we have shown that PKC isoforms
negatively regulate ADP-induced thromboxane generation by regulating calcium
mobilization and ERK activation that in turn regulates cPLA2 activity.
We further investigated the PKC isoforms involved in this process. Based on our results
with Go-6976, a classical PKC inhibitor and GF109203X, a pan PKC inhibitor, we
identified that that novel or atypical PKC isoforms are involved in negative regulation of
ADP-induced thromboxane generation. Thus, we investigated the role of various novel
class of PKC isoforms (nPKCs) in platelets. We first investigated the nPKCs activated by
ADP. In aspirin-treated platelets, ADP failed to activate nPKC θ and δ non-stirring
conditions. Thus, we conclude that these isoforms are not involved in negative regulation
of thromboxane…
Advisors/Committee Members: Kunapuli, Satya P., Driska, Steven Paul, Eguchi, Satoru, Daniel, James L., Bray, Paul F..
Subjects/Keywords: Biology, Cell; Biology, Physiology; ADP receptors; Phosphatases; Platelet signaling; Protein Kinase C; thromboxane
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share





❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Bynagari, Y. S. (2010). Molecular Physiology of Novel Class of Protein Kinase C isoforms in Platelets. (Doctoral Dissertation). Temple University. Retrieved from http://digital.library.temple.edu/u?/p245801coll10,103230
Chicago Manual of Style (16th Edition):
Bynagari, Yamini Saraswathy. “Molecular Physiology of Novel Class of Protein Kinase C isoforms in Platelets.” 2010. Doctoral Dissertation, Temple University. Accessed April 15, 2021.
http://digital.library.temple.edu/u?/p245801coll10,103230.
MLA Handbook (7th Edition):
Bynagari, Yamini Saraswathy. “Molecular Physiology of Novel Class of Protein Kinase C isoforms in Platelets.” 2010. Web. 15 Apr 2021.
Vancouver:
Bynagari YS. Molecular Physiology of Novel Class of Protein Kinase C isoforms in Platelets. [Internet] [Doctoral dissertation]. Temple University; 2010. [cited 2021 Apr 15].
Available from: http://digital.library.temple.edu/u?/p245801coll10,103230.
Council of Science Editors:
Bynagari YS. Molecular Physiology of Novel Class of Protein Kinase C isoforms in Platelets. [Doctoral Dissertation]. Temple University; 2010. Available from: http://digital.library.temple.edu/u?/p245801coll10,103230

Temple University
4.
Miller, Jonathan S.
GSK3: A Neuromodulator of Cocaine-Induced Behavioral Responses.
Degree: PhD, 2009, Temple University
URL: http://digital.library.temple.edu/u?/p245801coll10,40192
► Pharmacology
Cocaine is a highly abused psychostimulant with repeated use potential culminating in addiction, a disease associated with compulsive drug seeking, use and high rates…
(more)
▼ Pharmacology
Cocaine is a highly abused psychostimulant with repeated use potential culminating in addiction, a disease associated with compulsive drug seeking, use and high rates of relapse despite adverse consequences. It is well established that cocaine acts by binding to and blocking monoamine transporters therefore increasing synaptic extracellular monoamine concentrations. Cocaine also increases extracellular levels of the excitatory amino acid glutamate within the neural circuitry comprising the ascending dopamine system. Cocaine induces a number of behavioral and neurochemical manifestations following acute and repeated administration. As such, elucidating the molecular mechanisms involved in the behavioral and neuromodulatory effects of cocaine are critical to the development of effective pharmacotherapies for cocaine addiction.
The overall aim of this research was to identify a novel kinase that may be involved in the behavioral effects of cocaine. Thus, we chose to investigate glycogen synthase kinase-3 (GSK3), which has recently gained attention as being critical in dopaminergic and glutamatergic signal transduction. GSK3 is a critical mediator of many intracellular signaling systems. The activity of GSK3 is regulated by several kinases including Akt, with inactivation occurring via phosphorylation of the inhibitory serine-21(α-isoform) and serine-9 (β-isoform) residues. It is well established that acute cocaine administration causes hyper-locomotion in animal models and that repeated cocaine administration elicits a sensitized or increased response to the locomotor-stimulating properties of the drug. The studies outlined herein sought to determine whether non-selective and selective inhibition of GSK3 would regulate acute cocaine-induced hyper-locomotion. Further, we investigated the role of GSK3 in the development of cocaine-induced locomotor sensitization. Results of the research outlined herein demonstrate that pharmacological inhibition of GSK3 reduced both the acute behavioral responses to cocaine and the long-term neuroadaptations produced by repeated cocaine, therefore suggesting a role for GSK3 in the behavioral manifestations associated with cocaine exposure.
Previous studies have assessed the role of the dopamine D1 receptor in locomotor behaviors. As cocaine indirectly activates dopamine D1 receptors, we investigated whether activation of GSK3 was necessary for the expression of dopamine D1 receptor-mediated behaviors. To assess the role of GSK3 in dopamine D1 receptor-induced hyperactivity, GSK3 was inhibited prior to administration of the selective dopamine D1 receptor agonist SKF-82958. Selective inhibition of GSK3 reduced ambulatory and stereotypic activity produced by SKF-82958. These data implicate a role for GSK3 in the behavioral manifestations associated with dopamine D1 receptor activation.
To further assess the importance of GSK3 in cocaine-induced behaviors we investigated the role of GSK3 in various facets of cocaine-conditioned reward. We show that selective inhibition of…
Advisors/Committee Members: Unterwald, Ellen M., Ashby, Barrie, Daniel, James L., Ehrlich, Michelle E., Kirby, Lynn, Tallarida, Ronald J..
Subjects/Keywords: Health Sciences, Pharmacology; Brain; Cocaine; Dopamine; Glutamate; Glycogen Synthase Kinase-3; Mouse
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share





❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Miller, J. S. (2009). GSK3: A Neuromodulator of Cocaine-Induced Behavioral Responses. (Doctoral Dissertation). Temple University. Retrieved from http://digital.library.temple.edu/u?/p245801coll10,40192
Chicago Manual of Style (16th Edition):
Miller, Jonathan S. “GSK3: A Neuromodulator of Cocaine-Induced Behavioral Responses.” 2009. Doctoral Dissertation, Temple University. Accessed April 15, 2021.
http://digital.library.temple.edu/u?/p245801coll10,40192.
MLA Handbook (7th Edition):
Miller, Jonathan S. “GSK3: A Neuromodulator of Cocaine-Induced Behavioral Responses.” 2009. Web. 15 Apr 2021.
Vancouver:
Miller JS. GSK3: A Neuromodulator of Cocaine-Induced Behavioral Responses. [Internet] [Doctoral dissertation]. Temple University; 2009. [cited 2021 Apr 15].
Available from: http://digital.library.temple.edu/u?/p245801coll10,40192.
Council of Science Editors:
Miller JS. GSK3: A Neuromodulator of Cocaine-Induced Behavioral Responses. [Doctoral Dissertation]. Temple University; 2009. Available from: http://digital.library.temple.edu/u?/p245801coll10,40192

Temple University
5.
Albano, Jennifer Nicole.
Localization of Human Prostaglandin E2 Receptors in Polarized Epithelial Cells.
Degree: PhD, 2008, Temple University
URL: http://digital.library.temple.edu/u?/p245801coll10,17898
► Pharmacology
The underlying mechanisms of protein sorting in polarized epithelial cells are poorly understood. Several studies have determined membrane targeting of G protein-coupled receptors (GPCRs)…
(more)
▼ Pharmacology
The underlying mechanisms of protein sorting in polarized epithelial cells are poorly understood. Several studies have determined membrane targeting of G protein-coupled receptors (GPCRs) using epithelial cells such as Madin-Darby canine kidney (MDCK) cells. Polarized epithelial cells are composed of apical and basolateral plasma membrane domains with specific protein compositions separated by tight junctions. Purinergic, muscarinic, and adrenergic receptors are a few examples of GPCRs that have been shown to localize to specific membranes in MDCK cells. The current work seeks to determine the differences in subcellular localization of the human prostaglandin E2 receptors. The EP receptors are all GPCRs, which differ in their second messenger pathways. The EP3 receptor is unique in that it has eight different isoforms that differ in the lengths of the carboxyl tail.
The EP3 isoforms, as well as the EP2 and EP4 receptors, have distinct properties, including different agonist-induced internalization patterns. We have also shown the EP3 isoforms have tissue-specific distribution patterns.
To further study the differences among the PGE2 receptors, we examined their subcellular localization patterns in polarized epithelial cells. We have determined the unique subcellular localization patterns for the receptors, as well as three mutants in MDCK cells. The localization patterns for these receptors in human bronchial epithelial (BEAS-2B) cells were quite similar to the MDCK cells, suggesting that receptor localization is not dependent on cell type. Additionally, in an attempt to locate structural motifs responsible for apical or basolateral localization, receptor chimeras between the purinergic P2Y2/P2Y4 receptors and EP3.VI isoform were constructed. Overall, the aim of our work was to define the subcellular localization patterns of various human prostaglandin E2 receptors and our results suggest the differences among them may correlate to the diverse physiological actions of PGE2 throughout the body.
Temple University – Theses
Advisors/Committee Members: Ashby, Barrie, Daniel, James L., Dun, Nae J., Liu-Chen, Lee-Yuan, Dhanasekaran, Danny, Smyth, Emer M..
Subjects/Keywords: Health Sciences, Pharmacology; Biology, Molecular
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share





❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Albano, J. N. (2008). Localization of Human Prostaglandin E2 Receptors in Polarized Epithelial Cells. (Doctoral Dissertation). Temple University. Retrieved from http://digital.library.temple.edu/u?/p245801coll10,17898
Chicago Manual of Style (16th Edition):
Albano, Jennifer Nicole. “Localization of Human Prostaglandin E2 Receptors in Polarized Epithelial Cells.” 2008. Doctoral Dissertation, Temple University. Accessed April 15, 2021.
http://digital.library.temple.edu/u?/p245801coll10,17898.
MLA Handbook (7th Edition):
Albano, Jennifer Nicole. “Localization of Human Prostaglandin E2 Receptors in Polarized Epithelial Cells.” 2008. Web. 15 Apr 2021.
Vancouver:
Albano JN. Localization of Human Prostaglandin E2 Receptors in Polarized Epithelial Cells. [Internet] [Doctoral dissertation]. Temple University; 2008. [cited 2021 Apr 15].
Available from: http://digital.library.temple.edu/u?/p245801coll10,17898.
Council of Science Editors:
Albano JN. Localization of Human Prostaglandin E2 Receptors in Polarized Epithelial Cells. [Doctoral Dissertation]. Temple University; 2008. Available from: http://digital.library.temple.edu/u?/p245801coll10,17898

Temple University
6.
Mao, Yingying.
ROLE OF PROTEASE-ACTIVATED RECEPTORS IN PLATELET ACTIVATION.
Degree: PhD, 2009, Temple University
URL: http://digital.library.temple.edu/u?/p245801coll10,47279
► Physiology
Platelets act as a fundamental component of the hemostatic process and their activation leads to the formation of a stable clot at the injured…
(more)
▼ Physiology
Platelets act as a fundamental component of the hemostatic process and their activation leads to the formation of a stable clot at the injured endothelium surface. Thrombin, as the important physiological agonist, activates platelets through protease-activated receptors (PARs). Protease-activated receptors are one of the major receptors in platelets and belong to the seven-transmembrane G-protein couple receptor family. Four protease-activated receptors are found, named as PAR1, PAR2, PAR3 and PAR4. Human platelets express PAR1 and PAR4 and murine platelets express PAR4 and PAR3 instead of PAR1. Thrombin activates PARs through a unique mechanism, involving the cleavage of N-terminus of PAR receptors and the newly exposed N-terminus acts as its own tethered ligand to bind and activate the receptor. In this study, we characterized a new PAR1 specific activating peptide (TFRRRLSRATR), generated from the c-terminus of human platelet P2Y1 receptor, and evaluated its biological function. This peptide activated platelets in a concentration-dependent manner, causing shape change, aggregation, secretion and calcium mobilization. Its activation is completely inhibited by using BMS200261, a PAR-1 specific antagonist. Its specificity to PAR1 receptor is further confirmed by using TFRRR-peptide-pretreated washed platelets and murine platelets. The shape change induced by 10 microM peptide was totally abolished by Y-27632, an inhibitor of p160ROCK which is the downstream signal of G12/13 pathways. The TFRRR-peptide, YFLLRNP, and the physiological agonist thrombin selectively activated G12/13 pathways at low concentrations and began to activate both Gq and G12/13 pathways with increased concentrations. Similar to SFLLRN, the TFRRR-peptide caused phosphorylation of Akt and Erk in a P2Y12 receptor-dependent manner, and p-38 MAP kinase activation in a P2Y12-independent manner. The effects of this peptide are elicited by the first six amino acids (TFRRRL) whereas the remaining peptide (LSRATR), TFERRN, or TFEERN had no effects on platelets.
Beside thrombin, PARs also can be activated by other proteases. Previous studies in our lab show that plasmin, a major extracellular protease, activates both human and murine platelets through prototypical cleavage of PAR4 (Quinton et al., 2004). In this study, we continue our study and investigate the molecular basis for the differential activation of murine and human platelets by plasmin. Plasmin-induced full aggregation is achieved at lower concentrations (0.1 U/mL) in murine platelets as compared to human platelets (1 U/mL). In COS7 cells expressing the murine PAR4 (mPAR4) receptor, 1 U/mL plasmin caused a higher intracellular calcium mobilization than in cells expressing the human PAR4 (hPAR4) receptor. This difference was reversed when the tethered ligand sequences of mPAR4 and hPAR4 were interchanged through site-directed mutagenesis. This difference between human and murine PAR4 is not because of the cofactor effect of PAR3 in murine platelets by…
Advisors/Committee Members: Kunapuli, Satya P., Daniel, James L., Tuma, Ronald F. (Ronald Franklin), Autieri, Michael V., Driska, Steven Paul, Woulfe, Donna.
Subjects/Keywords: Biology, Physiology; ischemic injury; PAR1 agonist; plasmin; platelet; protease-activated receptor
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share





❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Mao, Y. (2009). ROLE OF PROTEASE-ACTIVATED RECEPTORS IN PLATELET ACTIVATION. (Doctoral Dissertation). Temple University. Retrieved from http://digital.library.temple.edu/u?/p245801coll10,47279
Chicago Manual of Style (16th Edition):
Mao, Yingying. “ROLE OF PROTEASE-ACTIVATED RECEPTORS IN PLATELET ACTIVATION.” 2009. Doctoral Dissertation, Temple University. Accessed April 15, 2021.
http://digital.library.temple.edu/u?/p245801coll10,47279.
MLA Handbook (7th Edition):
Mao, Yingying. “ROLE OF PROTEASE-ACTIVATED RECEPTORS IN PLATELET ACTIVATION.” 2009. Web. 15 Apr 2021.
Vancouver:
Mao Y. ROLE OF PROTEASE-ACTIVATED RECEPTORS IN PLATELET ACTIVATION. [Internet] [Doctoral dissertation]. Temple University; 2009. [cited 2021 Apr 15].
Available from: http://digital.library.temple.edu/u?/p245801coll10,47279.
Council of Science Editors:
Mao Y. ROLE OF PROTEASE-ACTIVATED RECEPTORS IN PLATELET ACTIVATION. [Doctoral Dissertation]. Temple University; 2009. Available from: http://digital.library.temple.edu/u?/p245801coll10,47279
.