Limits...
Conditioning for hematopoietic transplantation activates the complement cascade and induces a proteolytic environment in bone marrow: a novel role for bioactive lipids and soluble C5b-C9 as homing factors.

Kim CH, Wu W, Wysoczynski M, Abdel-Latif A, Sunkara M, Morris A, Kucia M, Ratajczak J, Ratajczak MZ - Leukemia (2011)

Bottom Line: As a result, BM is enriched for proteolytic enzymes and the soluble form of the terminal product of CC activation, the membrane attack complex C5b-C9 (MAC).Next, we observed that C5-deficient mice that do not generate MAC show impaired engraftment of HSPCs.We conclude that an increase in BM levels of proteolytic enzyme-resistant S1P and C1P and activation of CC, which leads to the generation of MAC, has an important and previously underappreciated role in the homing of transplanted HSPCs.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, Stem Cell Institute at the James Graham Brown Cancer Center, University of Louisville, Louisville, KY 40202, USA.

ABSTRACT
We have observed that conditioning for hematopoietic transplantation by lethal irradiation induces a proteolytic microenvironment in the bone marrow (BM) that activates the complement cascade (CC). As a result, BM is enriched for proteolytic enzymes and the soluble form of the terminal product of CC activation, the membrane attack complex C5b-C9 (MAC). At the same time, proteolytic enzymes induced in irradiated BM impair the chemotactic activity of α-chemokine stromal-derived factor-1 (SDF-1). As SDF-1 is considered a crucial BM chemoattractant for transplanted hematopoietic stem/progenitor cells (HSPCs), we sought to determine whether other factors that are resistant to proteolytic enzymes have a role in this process, focusing on proteolysis-resistant bioactive lipids. We found that the concentrations of sphingosine-1-phosphate (S1P) and ceramide-1-phosphate (C1P) increase in the BM after conditioning for transplantation and that both S1P and, as we show here for the first time, C1P are potent chemoattractants for HSPCs. Next, we observed that C5-deficient mice that do not generate MAC show impaired engraftment of HSPCs. In support of a role for MAC in homing and engraftment, we found that soluble MAC enhances in a CR3 (CD11b/CD18)-dependent manner the adhesion of HSPCs to BM stromal cells and increases the secretion of SDF-1 by BM stroma. We conclude that an increase in BM levels of proteolytic enzyme-resistant S1P and C1P and activation of CC, which leads to the generation of MAC, has an important and previously underappreciated role in the homing of transplanted HSPCs.

Show MeSH

Related in: MedlinePlus

Bioactive lipids stimulate signaling pathways in murine Sca-1+ HSPCsC1P and S1P activate several signaling pathways in murine BMMNC that are crucial for cell migration and adhesion: MAPKp44/42, Akt, p38, Stat-3, and Stat-5. Before stimulation, cells were starved overnight in RPMI containing 0.5% BSA in an incubator and subsequently stimulated with S1P (0.02μM or 0.1μM) or C1P (20μM or 100μM) for 5 min. Experiments were repeated independently three times with similar results. A representative western blot is shown.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3197954&req=5

Figure 3: Bioactive lipids stimulate signaling pathways in murine Sca-1+ HSPCsC1P and S1P activate several signaling pathways in murine BMMNC that are crucial for cell migration and adhesion: MAPKp44/42, Akt, p38, Stat-3, and Stat-5. Before stimulation, cells were starved overnight in RPMI containing 0.5% BSA in an incubator and subsequently stimulated with S1P (0.02μM or 0.1μM) or C1P (20μM or 100μM) for 5 min. Experiments were repeated independently three times with similar results. A representative western blot is shown.

Mentions: S1P has already been reported to be a strong chemoattractant for HSPCs 15. To our surprise, we found that another bioactive lipid, C1P, in a similar way as S1P, induces several signaling pathways in murine Sca-1+ cells purified by immunomagnetic beads (Figure 3), as well as strongly chemoattacts murine HSPCs (Figure 4panel A andSupplementary Figure 1). However, both these bioactive lipids and soluble MAC (sMAC), as shown in Supplementary Figure 2 and 3 respectively, do not affect the clonogenicity of murine progenitors for all major hematopoietic lineages. The same result was found for their unphosphorylated forms (data not shown).


Conditioning for hematopoietic transplantation activates the complement cascade and induces a proteolytic environment in bone marrow: a novel role for bioactive lipids and soluble C5b-C9 as homing factors.

Kim CH, Wu W, Wysoczynski M, Abdel-Latif A, Sunkara M, Morris A, Kucia M, Ratajczak J, Ratajczak MZ - Leukemia (2011)

Bioactive lipids stimulate signaling pathways in murine Sca-1+ HSPCsC1P and S1P activate several signaling pathways in murine BMMNC that are crucial for cell migration and adhesion: MAPKp44/42, Akt, p38, Stat-3, and Stat-5. Before stimulation, cells were starved overnight in RPMI containing 0.5% BSA in an incubator and subsequently stimulated with S1P (0.02μM or 0.1μM) or C1P (20μM or 100μM) for 5 min. Experiments were repeated independently three times with similar results. A representative western blot is shown.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3197954&req=5

Figure 3: Bioactive lipids stimulate signaling pathways in murine Sca-1+ HSPCsC1P and S1P activate several signaling pathways in murine BMMNC that are crucial for cell migration and adhesion: MAPKp44/42, Akt, p38, Stat-3, and Stat-5. Before stimulation, cells were starved overnight in RPMI containing 0.5% BSA in an incubator and subsequently stimulated with S1P (0.02μM or 0.1μM) or C1P (20μM or 100μM) for 5 min. Experiments were repeated independently three times with similar results. A representative western blot is shown.
Mentions: S1P has already been reported to be a strong chemoattractant for HSPCs 15. To our surprise, we found that another bioactive lipid, C1P, in a similar way as S1P, induces several signaling pathways in murine Sca-1+ cells purified by immunomagnetic beads (Figure 3), as well as strongly chemoattacts murine HSPCs (Figure 4panel A andSupplementary Figure 1). However, both these bioactive lipids and soluble MAC (sMAC), as shown in Supplementary Figure 2 and 3 respectively, do not affect the clonogenicity of murine progenitors for all major hematopoietic lineages. The same result was found for their unphosphorylated forms (data not shown).

Bottom Line: As a result, BM is enriched for proteolytic enzymes and the soluble form of the terminal product of CC activation, the membrane attack complex C5b-C9 (MAC).Next, we observed that C5-deficient mice that do not generate MAC show impaired engraftment of HSPCs.We conclude that an increase in BM levels of proteolytic enzyme-resistant S1P and C1P and activation of CC, which leads to the generation of MAC, has an important and previously underappreciated role in the homing of transplanted HSPCs.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, Stem Cell Institute at the James Graham Brown Cancer Center, University of Louisville, Louisville, KY 40202, USA.

ABSTRACT
We have observed that conditioning for hematopoietic transplantation by lethal irradiation induces a proteolytic microenvironment in the bone marrow (BM) that activates the complement cascade (CC). As a result, BM is enriched for proteolytic enzymes and the soluble form of the terminal product of CC activation, the membrane attack complex C5b-C9 (MAC). At the same time, proteolytic enzymes induced in irradiated BM impair the chemotactic activity of α-chemokine stromal-derived factor-1 (SDF-1). As SDF-1 is considered a crucial BM chemoattractant for transplanted hematopoietic stem/progenitor cells (HSPCs), we sought to determine whether other factors that are resistant to proteolytic enzymes have a role in this process, focusing on proteolysis-resistant bioactive lipids. We found that the concentrations of sphingosine-1-phosphate (S1P) and ceramide-1-phosphate (C1P) increase in the BM after conditioning for transplantation and that both S1P and, as we show here for the first time, C1P are potent chemoattractants for HSPCs. Next, we observed that C5-deficient mice that do not generate MAC show impaired engraftment of HSPCs. In support of a role for MAC in homing and engraftment, we found that soluble MAC enhances in a CR3 (CD11b/CD18)-dependent manner the adhesion of HSPCs to BM stromal cells and increases the secretion of SDF-1 by BM stroma. We conclude that an increase in BM levels of proteolytic enzyme-resistant S1P and C1P and activation of CC, which leads to the generation of MAC, has an important and previously underappreciated role in the homing of transplanted HSPCs.

Show MeSH
Related in: MedlinePlus