Regenerative effect of platelet-rich plasma in the murine ischemic limbs

Hepatic fibrosis is a worldwide health problem with significant morbidity and mortality. Currently, there is no effective therapy for hepatic fibrosis. The present study was aimed to evaluate the possible regenerative effect of platelet-rich plasma (PRP) against thioacetamide (TAA)-induced hepatic damage. Eighty albino rats were included; 40 were used for PRP preparation and 40 were randomly divided into 4 groups: group I (control group); group II (PRP control); group III (TAA-intoxicated by a dose of 200 mg/kg body mass, intraperitoneally, twice weekly for 7 weeks), and group IV (TAA intoxicated + PRP treated). Macrophage inflammatory protein-1α (MIP-1α) and cyclic adenosine monophosphate (cAMP) were immunoassayed in addition to peroxinitrite level, NADPH-quinone oxidoreductase-1 (NQO1) enzyme activity, and liver function. PRP treatment showed significant improvement in hepatic function, and decreased MIP-1α and peroxinitrite levels. Meanwhile, significant increase in NQO1 enzyme activity and cAMP level were observed. The histopathological results confirmed the laboratory results with improvement of hepatic architecture except for some inflammatory cellular infiltrates. This study shows that PRP has the ability to protect against TAA-induced liver damage, possibly by improving redox status, liver histopathological architecture, and disruption of the inflammatory and fibrotic response induced by TAA.

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Encapsulation of Rat Bone Marrow Derived Mesenchymal Stem Cells (rBMMSCs) in Collagen Type I Containing Platelet-Rich Plasma for Osteoarthritis Treatment in Rat Model

10.21203/rs.3.rs-875172/v1 ◽

2021 ◽

Author(s):

somayeh Ebrahimi-barough ◽

Md Shahidul Islam ◽

Mamun Al Mahtab ◽

Sadegh Shirian ◽

Hamid Reza Aghayan ◽

...

Keyword(s):

Knee Joint ◽

Rat Model ◽

Collagen Type ◽

Platelet Rich Plasma ◽

Cartilage Damage ◽

Collagen Type I ◽

Joint Disease ◽

Type I ◽

Regenerative Effect

Abstract Osteoarthritis (OA) is the most common form of degenerative joint disease, affecting more than 25% of the adult though prevalent in the elderly population. Most of the current therapeutic modalities aim at symptomatic treatment and lingering the disease progression. In recent years, regenerative medicine such as stem cell transplantation and tissue engineering has been suggested as a potential curative intervention for OA. The objective of current study was to assess the safety and efficacy of an injectable tissue-engineered construct composed of BMMSCs, PRP, and Collagen type I in rat model of OA.To produce collagen type I, PRP and BMMSCs, male Wistar rats were ethically euthanized. After expansion and characterization of rat BMMSCs (rBMMSCs), tissue-engineered construct was formed by combination of appropriate amount of collagen type I, PRP and rBMMSCs. In vitro studies were conducted to evaluate the effect of PRP on chondrogenic differentiation capacity of encapsulated cells. Then tissue-engineered construct was injected in knee joint of rat model of OA (24 rat in 4 groups:OA, OA+MSC, ‎OA+Collagen+MSC+PRP, OA+MSC+Collagen).After 6 weeks, the animals were euthanized and knee joint histopathology examinations were performed to evaluate the effect of each treatment on OA.Tissue-engineered construct was successfully manufactured and in vitro assays demonstrated that relevant chondrogenic genes and proteins expression were higher in PRP group than the others. Histopathological findings of the knee joint samples showed favorable regenerative effect of rBMMSCs+PRP+Collagengroup comparing to others.In this study, we introduced an injectable tissue-engineered product composed of rBMMSCs+PRP+Collagenwith potential regenerative effect on cartilage damage caused by OA.

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Visualization of the Platelet-Plasma Interface

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100079905 ◽

1977 ◽

Vol 35 ◽

pp. 494-495

Author(s):

D. C. Brindley ◽

M. McGill

Keyword(s):

Platelet Rich Plasma ◽

Coagulation Factors ◽

Platelet Membrane ◽

Rabbit Platelet ◽

Surface Coat ◽

Special Relationship ◽

Routine Method ◽

Embedding Technique ◽

Biochemical Analyses ◽

Adsorptive Properties

Morphological and cytochemical studies of platelets have reported a surface coat, or glycocalyx, external to the plasma membrane (1). Biochemical analyses have likewise confirmed the highly adsorptive properties of platelets as transporters of coagulation factors (2). However, visualization of the platelet membrane by conventional EM procedures does not reflect this special relationship between the platelet and its plasma environment. By the routine method of alcohol-propylene oxide dehydration for Epon embedding, the lipid bilayer nature of the platelet membrane appears similar to other blood cells (Fig. 1). A new rapid embedding technique using dimethoxypropane (DMP) as dehydrating agent (13) has permitted ultrastructural analyses of the surface features of the platelet-plasma interface.Aliquots of human or rabbit platelet-rich plasma (PRP) were added to equal volumes of 6% glutaraldehyde in Millonig's buffer at 37° for 45 minutes, rinsed in buffer and postfixed in 1% osmium in Millonig's buffer for 45 minutes.

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Activation of Platelets in Platelet-rich Plasma by Rotablation Is Speed Dependent and Can Be Inhibited by Abciximab (c7E3 Fab; ReoProTM

Journal of the American College of Cardiology ◽

10.1016/s0735-1097(97)84736-5 ◽

1998 ◽

Vol 31 (2) ◽

pp. 237A ◽

Cited By ~ 1

Author(s):

M Williams

Keyword(s):

Platelet Rich Plasma

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Functional Characterization of PM6/13, a β3-specific (GPIIIa/CD61) Monoclonal Antibody that Shows Preferential Inhibition of Fibrinogen Binding over Fibronectin Binding to Activated Human Platelets

Thrombosis and Haemostasis ◽

10.1055/s-0037-1614247 ◽

1998 ◽

Vol 79 (01) ◽

pp. 177-185 ◽

Cited By ~ 10

Author(s):

Ashia Siddiqua ◽

Michael Wilkinson ◽

Vijay Kakkar ◽

Yatin Patel ◽

Salman Rahman ◽

...

Keyword(s):

Monoclonal Antibody ◽

Platelet Aggregation ◽

Platelet Rich Plasma ◽

Functional Characterization ◽

Human Platelets ◽

Western Blots ◽

Activated Platelets ◽

Reducing Conditions ◽

Fibronectin Binding

SummaryWe report the characterization of a monoclonal antibody (MAb) PM6/13 which recognises glycoprotein IIIa (GPIIIa) on platelet membranes and in functional studies inhibits platelet aggregation induced by all agonists examined. In platelet-rich plasma, inhibition of aggregation induced by ADP or low concentrations of collagen was accompanied by inhibition of 5-hydroxytryptamine secretion. EC50 values were 10 and 9 [H9262]g/ml antibody against ADP and collagen induced responses respectively. In washed platelets treated with the cyclooxygenase inhibitor, indomethacin, PM6/13 inhibited platelet aggregation induced by thrombin (0.2 U/ml), collagen (10 [H9262]g/ml) and U46619 (3 [H9262]M) with EC50 = 4, 8 and 4 [H9262]g/ml respectively, without affecting [14C]5-hydroxytryptamine secretion or [3H]arachidonate release in appropriately labelled cells. Studies in Fura 2-labelled platelets revealed that elevation of intracellular calcium by ADP, thrombin or U46619 was unaffected by PM6/13 suggesting that the epitope recognised by the antibody did not influence Ca2+ regulation. In agreement with the results from the platelet aggregation studies, PM6/13 was found to potently inhibit binding of 125I-fibrinogen to ADP activated platelets. Binding of this ligand was also inhibited by two other MAbs tested, namely SZ-21 (also to GPIIIa) and PM6/248 (to the GPIIb-IIIa complex). However when tested against binding of 125I-fibronectin to thrombin stimulated platelets, PM6/13 was ineffective in contrast with SZ-21 and PM6/248, that were both potent inhibitors. This suggested that the epitopes recognised by PM6/13 and SZ-21 on GPIIIa were distinct. Studies employing proteolytic dissection of 125I-labelled GPIIIa by trypsin followed by immunoprecipitation with PM6/13 and analysis by SDS-PAGE, revealed the presence of four fragments at 70, 55, 30 and 28 kDa. PM6/13 did not recognize any protein bands on Western blots performed under reducing conditions. However Western blotting analysis with PM6/13 under non-reducing conditions revealed strong detection of the parent GP IIIa molecule, of trypsin treated samples revealed recognition of an 80 kDa fragment at 1 min, faint recognition of a 60 kDa fragment at 60 min and no recognition of any product at 18 h treatment. Under similar conditions, SZ-21 recognized fragments at 80, 75 and 55 kDa with the 55kDa species persisting even after 18 h trypsin treatment. These studies confirm the epitopes recognised by PM6/13 and SZ-21 to be distinct and that PM6/13 represents a useful tool to differentiate the characteristics of fibrinogen and fibronectin binding to the GPIIb-IIIa complex on activated platelets.

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Phospholipase C from Clostridium Perfringens Induces Human Platelet Aggregation in Plasma

Thrombosis and Haemostasis ◽

10.1055/s-0038-1642761 ◽

1988 ◽

Vol 59 (02) ◽

pp. 236-239 ◽

Cited By ~ 2

Author(s):

Giovanna Barzaghi ◽

Chiara Cerletti ◽

Giovanni de Gaetano

Keyword(s):

Platelet Aggregation ◽

Receptor Antagonist ◽

Phospholipase C ◽

Clostridium Perfringens ◽

Human Platelet ◽

Ex Vivo ◽

Platelet Rich Plasma ◽

Platelet Activating Factor ◽

Inhibitory Effect ◽

Thromboxane Receptor Antagonist

SummaryWe studied the aggregating effect of different concentrations of phospholipase C (PLC) (extracted from Clostridium perfringens) on human platelet-rich plasma (PRP). PRP was preincubated with PLC for 3 min at 37° C and the platelet aggregation was followed for 10 min. The threshold aggregating concentration (TAG) of PLC was 3-4 U/ml.We also studied the potentiation of PLC with other stimuli on platelet aggregation. Potentiating stimuli, such as arachidonic acid (AA), ADP. Platelet Activating Factor (PAF) and U-46619 (a stable analogue of cyclic endoperoxides) were all used at subthreshold concentrations. We also studied the possible inhibitory effect of aspirin, apyrase, TMQ, a prostaglandin endoper- oxide/thromboxane receptor antagonist and BN-52021, a PAF receptor antagonist. Only aspirin and apyrase were able to reduce aggregation induced by PLC alone and PLC + AA and PLC + ADP respectively. TMQ and BN-52021 were inactive. In ex vivo experiments oral aspirin (500 mg) partially inhibited platelet aggregation induced by PLC alone, PLC + AA and PLC + ADP 2 and 24 h after administration. Aspirin 20 mg for 7 days also reduced aggregation induced by PLC + AA.

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Time Dependence of Whole Blood Aggregation in Response to Platelet Activating Factor (PAF)

Thrombosis and Haemostasis ◽

10.1055/s-0038-1642746 ◽

1988 ◽

Vol 59 (02) ◽

pp. 162-163 ◽

Cited By ~ 5

Author(s):

R R Taylor ◽

J Strophair ◽

M Sturm ◽

R Vandongen ◽

L J Beilin

Keyword(s):

Time Dependence ◽

Whole Blood ◽

Platelet Rich Plasma ◽

Platelet Activating Factor ◽

Sampling Time ◽

Blood Sampling ◽

Impedance Aggregometry

SummaryThe aggregation/adhesion response to platelet activating factor (PAF) was studied in diluted whole blood by impedance aggregometry. The extent of aggregation varied directly with the interval between blood sampling and aggregation measurement over the first 30 minutes from sampling, then remained stable for the next 60 minutes of observation. This is an effect opposite to that described for aggregation to PAF in platelet rich plasma which, however, cannot be studied soon after sampling. Time dependence of aggregation is important and comparative measurements should be made during the period of stable aggregability.

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Platelet-Bound Prekallikrein Promotes Pro-Urokinase-Induced Clot Lysis: A Mechanism for Targeting the Factor XII Dependent Intrinsic Pathway of Fibrinolysis

Thrombosis and Haemostasis ◽

10.1055/s-0038-1642441 ◽

1994 ◽

Vol 71 (03) ◽

pp. 347-352 ◽

Cited By ~ 36

Author(s):

Jean-Pierre Loza ◽

Victor Gurewich ◽

Michael Johnstone ◽

Ralph Pannell

Keyword(s):

Platelet Rich Plasma ◽

Specific Inhibitor ◽

Specific Effect ◽

Clot Lysis ◽

Factor Xii ◽

Intrinsic Pathway ◽

Clot Retraction ◽

Enzymatic Mechanism ◽

Low Concentrations ◽

Factor Xiia

SummaryClots formed from platelet rich plasma were found to be lysed more readily by low concentrations of pro-urokinase (pro-UK) than clots formed from platelet poor plasma. This was not a non-specific effect since the reverse occurred with tissue plasminogen activator. A mechanical explanation due to platelet-mediated clot retraction was excluded by experiments in which retraction was inhibited with cyto-chalasin B. Therefore, a platelet-mediated enzymatic mechanism was postulated to explain the promotion of fibrinolysis. Casein autography of isolated platelets revealed a ≈ 90 kDa band of activity which comigrated with plasma prekallikrein (PK)/kallikrein, a known activator of pro-UK. Furthermore, treatment of platelets with plasma PK activator (PPA), consisting essentially of factor XIIa, induced activation of pro-UK and of chromomgenic substrate for kallikrein (S-2302). This activity corresponded to approximately 40-200 pM kallikrein per 10 8 washed and gel filtered platelets per ml. The activation of pro-UK by PPA-pretreated platelets was dose-dependent and inhibited by soybean trypsin inhibitor but not by bdellin, a specific inhibitor of plasmin, nor by the corn inhibitor of factor XIIa. Kinetic analysis of pro-UK activation by kallikrein showed promotion of the reaction by platelets. The KM of the reaction was reduced by platelets by ≈ 7-fold, while the kcat was essentially unchanged. In conclusion, PK was shown to be tightly associated with platelets where it can be activated by factor XIIa during clotting. The activation of pro-UK by platelet-bound kallikrein provides an explanation for the observed platelet mediated promotion of pro-UK-induced clot lysis. Since pro-UK and plasminogen have also been shown to be associated with platelets, the present findings suggest a mechanism by which the factor Xlla-dependent intrinsic pathway of fibrinolysis can be localized and targeted to a thrombus.

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