Recombinant Rat P-selectin (Selp)
Description
Functional Mechanisms
-
Leukocyte Adhesion: Mediates rapid leukocyte rolling via PSGL-1 binding, facilitating neutrophil and monocyte interactions with activated endothelium .
-
Cellular Signaling: Activates Src kinase pathways within 30 minutes of binding, influencing ERK, AKT, and FAK phosphorylation in neuroblastoma models .
-
Thrombosis Regulation: Demonstrated 18% reduction in thrombus weight when P-selectin/PSGL-1 interactions are inhibited .
Comparative Studies
Transgenic murine models expressing human SELP reveal functional differences:
| Parameter | Rat/Human P-Selectin | Murine P-Selectin |
|---|---|---|
| TNF-α Response | Downregulated expression | Upregulated expression |
| Leukocyte Rolling | Accelerated velocity | Slowed velocity |
| Skin Inflammation Role | Secondary to E-selectin | Dominant in leukocyte recruitment |
These differences underscore species-specific regulatory mechanisms affecting inflammatory responses .
Disease Relevance
-
Cancer: Anti-P-selectin antibodies reduced neuroblastoma growth by 40% in murine xenografts (p=0.00581) .
-
Neuroinflammation: SELP inhibition improves immune infiltration in glioblastoma models by suppressing immunosuppressive microglia .
-
Thrombosis: Recombinant PSGL-1-Ig reduces fibrin deposition by competing with endogenous ligands .
Research Applications
-
In Vitro Adhesion Assays: Used to quantify leukocyte-endothelial interactions under shear stress .
-
Drug Development: Targeted by monoclonal antibodies (e.g., KF-38789) in Phase II trials for cardiovascular diseases .
-
Immune Cell Trafficking Studies: Critical for analyzing PSGL-1-dependent neutrophil recruitment in trauma models .
Product Specs
Note: We will prioritize shipping the format we currently have in stock. However, if you require a specific format, please indicate your preference when placing the order, and we will fulfill your request.
Note: All of our proteins are shipped with standard blue ice packs by default. If dry ice shipping is preferred, please notify us in advance, as additional fees will apply.
Generally, the shelf life of the liquid form is 6 months at -20°C/-80°C. The shelf life of the lyophilized form is 12 months at -20°C/-80°C.
Target Background
- Aortic cyclooxygenase-2 and P-selectin were significantly down-regulated in plant sterols and plant sterols + tripeptides groups. PMID: 22575043
- Fibrinogen can interact with P-selectin to contribute to the development of atherosclerosis. High levels of fibrinogen and P-selectin can be considered risk factors for markers of atherosclerosis. PMID: 22340239
- Renal injury after ischemia/reperfusion may be associated with the strong expression of P-selectin. NO may have a protective effect by reducing the expression of P-selectin and mitigating the adhesion, aggregation, and infiltration of neutrophils. PMID: 21180132
- Both baicalin and octreotide can exert protective effects on multiple organs in rats with severe acute pancreatitis by reducing P-selectin expression. PMID: 19780886
- Volatile oil of Magnolia biondii can protect the kidney in rats with diabetic nephropathy by inhibiting the expression of P-selectin protein in serum and renal tissue. PMID: 18471420
- P-selectin contributes to massive infiltration of Mo into the interstitium by acting as specialized post-capillary venules. PMID: 12081568
- P-selectin was highly expressed on glomerular endothelial cells after injection of nephrotoxic serum. P-selectin partially mediates glomerular infiltration of macrophages in experimental crescentic glomerulonephritis. PMID: 12100021
- Blockade of this molecule protects rat steatotic liver grafts from ischemia/reperfusion injury. PMID: 12201360
- P-selectin significantly increases CD45-positive leukocyte activation, inflammation, and neointimal formation in a Zucker diabetic rat carotid artery balloon injury model. PMID: 12377736
- Neointimal rat SMCs supported a 2.5-fold higher arrest of monocytes and "memory" T lymphocytes than medial SMCs, which was dependent on both P-selectin and VLA-4. PMID: 14963004
- P-selectin increased significantly in hepatic sinusoidal endothelial cells and renal tubular epithelial cells 1 h after ischemia-reperfusion. PMID: 15742404
- Expression of the P-selectin gene is induced through the activation of NF-kappaB, suggesting that P-selectin may be involved in the pathogenesis of diabetic nephropathy. PMID: 15888973
- P-selectin plays a role in ischemia-reperfusion injury in experimental myocardial infarct. PMID: 17488661
Q&A
What is the biological significance of recombinant Rat P-selectin (Selp) in inflammation research?
Recombinant Rat P-selectin plays a pivotal role in mediating leukocyte rolling and adhesion during the initial stages of inflammation. This adhesion molecule is stored in the alpha-granules of platelets and Weibel-Palade bodies of endothelial cells and redistributes to the plasma membrane upon activation. It facilitates interactions between activated endothelial cells or platelets and leukocytes via binding to sialylated Lewis blood group carbohydrate antigens on neutrophils and monocytes . These processes are calcium-dependent, making Selp a crucial target for studying inflammatory pathways and their modulation.
How does recombinant Rat P-selectin interact with PSGL-1, and what experimental models are used to study this interaction?
P-selectin glycoprotein ligand-1 (PSGL-1) is the primary ligand for Selp. The interaction between Selp and PSGL-1 mediates tethering and rolling of leukocytes on activated platelets or endothelial cells. Molecular cloning studies have characterized the binding epitope of PSGL-1, which resides in its N-terminal region . Experimental models such as orthotopic liver transplantation (OLT) in rats have been employed to study this interaction under conditions of ischemia/reperfusion injury. In these models, blocking PSGL-1 with specific antibodies has demonstrated reduced leukocyte infiltration, decreased cytokine expression, and improved graft survival .
What are the methodological approaches for producing recombinant Rat P-selectin?
Recombinant Rat P-selectin is typically expressed using human cell lines engineered with a DNA sequence encoding Selp fused to a polyhistidine tag for purification purposes. The recombinant protein comprises 670 amino acids with a predicted molecular mass of 73.4 kDa but appears as approximately 114 kDa under reducing SDS-PAGE conditions due to post-translational modifications . Purity levels exceeding 95% are achieved through rigorous validation methods such as SDS-PAGE analysis .
How does recombinant Rat P-selectin contribute to thrombosis research?
Recombinant Rat P-selectin has been extensively studied in the context of thrombosis, particularly portal vein thrombosis (PVT). In rat models, intermittent portal vein obstruction combined with endothelial damage induces PVT. Pre-treatment with recombinant P-selectin glycoprotein ligand immunoglobulin G (rPSGL-Ig) significantly inhibits thrombus formation, reduces vessel diameter, and ameliorates histopathological changes in affected veins . These findings underscore its potential as a therapeutic target for thrombotic disorders.
What are the differences between human and murine P-selectin expression, and how do these differences impact experimental outcomes?
The basal and inducible expression patterns of human P-selectin differ significantly from murine P-selectin, leading to distinct functional outcomes in transgenic models. For example, tumor necrosis factor (TNF) increases murine P-selectin expression while decreasing human P-selectin expression under inflammatory conditions . These differences necessitate careful consideration when extrapolating results from murine models to human physiology.
How can researchers optimize experimental protocols involving recombinant Rat P-selectin?
Optimal experimental conditions depend on the specific application:
-
Western Blotting: Use affinity-purified polyclonal antibodies specific to Rat P-selectin at appropriate dilutions (e.g., 1 µg/mL), followed by HRP-conjugated secondary antibodies for detection .
-
Functional Assays: Employ immobilized recombinant Selp at concentrations like 10 µg/mL for adhesion studies to ensure maximal inhibition by specific antibodies .
-
Storage Conditions: Maintain recombinant Selp at -20°C to -70°C under sterile conditions to prevent degradation .
What are the challenges associated with studying Selp-mediated adhesion under dynamic flow conditions?
Dynamic flow conditions mimic physiological blood flow but introduce variables such as shear stress that can affect adhesion molecule interactions. Studies have shown that TNF modulates Selp-mediated rolling differently in human versus murine systems . Researchers must carefully calibrate flow chamber systems and account for species-specific differences when designing experiments.
How does targeting Selp influence ischemia/reperfusion injury outcomes?
Blocking Selp or its ligand PSGL-1 has demonstrated protective effects against ischemia/reperfusion injury in rat liver transplantation models. Pretreatment with anti-PSGL-1 antibodies reduces hepatocellular damage, decreases pro-inflammatory cytokine expression, and prevents apoptosis by upregulating anti-apoptotic genes like Bcl-2/Bcl-xL . These findings suggest that Selp-targeted therapies could enhance organ transplant success rates.
Are there any novel therapeutic strategies involving recombinant Rat P-selectin?
Recent studies have explored using rPSGL-Ig as a therapeutic agent for thrombosis prevention and inflammation modulation. In rat models of portal vein thrombosis, rPSGL-Ig significantly inhibited thrombus formation and reversed histopathological changes in affected vessels . Such strategies highlight the translational potential of recombinant Selp research.
Can recombinant Rat P-selectin be used to study platelet activation mechanisms?
Yes, Selp redistributes to the plasma membrane during platelet activation and degranulation, making it an excellent marker for studying these processes . Western blotting techniques using specific antibodies can detect Selp expression changes under various activation conditions .
