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Haematopoietic stem cell migration to the ischemic damaged kidney is not altered by manipulating the SDF-1/CXCR4-axis.

Stroo I, Stokman G, Teske GJ, Florquin S, Leemans JC - Nephrol. Dial. Transplant. (2009)

Bottom Line: Importantly, the amount of HSC in the ischemic kidney was markedly higher compared to the contralateral kidney.Neutralizing endogenous SDF-1 or HSC-associated CXCR4 did not prevent the migration of HSC.In conclusion, systemically administered HSC preferentially migrate to the ischemic injured kidney.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. I.Stroo@amc.uva.nl

ABSTRACT

Background: Haematopoietic stem cells (HSC) have been shown to migrate to the ischemic kidney. The factors that regulate the trafficking of HSC to the ischemic damaged kidney are not fully understood. The stromal cell-derived factor-1 (SDF-1)/CXCR4-axis has been identified as the central signalling axis regulating trafficking of HSC to the bone marrow. Therefore, we hypothesized that SDF-1/CXCR4 interactions are implicated in the migration of HSC to the injured kidney.

Methods: HSC were isolated from mouse bone marrow and labelled with a cell tracker. Acceptor mice were subjected to unilateral ischemia and received HSC intravenously directly after reperfusion. In addition, in separate groups of acceptor mice, endogenous SDF-1 or HSC-associated CXCR4 was blocked or kidneys were injected with SDF-1.

Results: Exogenous HSC could be detected in the tubules and interstitium of the kidney 24 h after ischemic injury. Importantly, the amount of HSC in the ischemic kidney was markedly higher compared to the contralateral kidney. Neutralizing endogenous SDF-1 or HSC-associated CXCR4 did not prevent the migration of HSC. No increase in the number of labelled HSC could be observed after local administration of SDF-1, as was also determined in bilateral kidney ischemia.

Conclusion: In conclusion, systemically administered HSC preferentially migrate to the ischemic injured kidney. This migration could not be prevented by blocking the SDF-1/CXCR4-axis or increased after local administration of SDF-1.

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Neutralizing SDF-1 and CXCR4 antibodies inhibit migration of HSC towards recSDF-1 and the bone marrow. (A) In an in vitro migration assay, the amount of migrated CM-DiI-labelled HSC from the upper to the lower compartment was determined as a percentage of the input. After 2 h at 37°C, 1.4% passive (control) migration of HSC was observed. Addition of 200 ng/mL recSDF-1 to the medium in the lower compartment increased HSC migration 8-fold. Neutralizing SDF-1 in the lower compartment or neutralizing HSC-associated CXCR4 in the upper compartment resulted in a 65% and 40% reduction of recSDF-1-induced migration, respectively. All experiments were performed in triplicate, bars represent mean ± SD, n = 2. (B–E) In an in vivo migration assay, the percentage of exogenous HSC (i.e. c-kit and CM-DiI positive) in the bone marrow was determined by flow cytometry 24 h after intravenous injection. Flow cytometry plots of (B) a non-injected control, (C) a positive control, (D) anti-CXCR4-treated mice and (E) anti-SDF-1-treated mice reveals only exogenous HSC in the positive control; no exogenous HSC could be detected in the bone marrow of anti-CXCR4- or anti-SDF-1-treated mice.
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Figure 3: Neutralizing SDF-1 and CXCR4 antibodies inhibit migration of HSC towards recSDF-1 and the bone marrow. (A) In an in vitro migration assay, the amount of migrated CM-DiI-labelled HSC from the upper to the lower compartment was determined as a percentage of the input. After 2 h at 37°C, 1.4% passive (control) migration of HSC was observed. Addition of 200 ng/mL recSDF-1 to the medium in the lower compartment increased HSC migration 8-fold. Neutralizing SDF-1 in the lower compartment or neutralizing HSC-associated CXCR4 in the upper compartment resulted in a 65% and 40% reduction of recSDF-1-induced migration, respectively. All experiments were performed in triplicate, bars represent mean ± SD, n = 2. (B–E) In an in vivo migration assay, the percentage of exogenous HSC (i.e. c-kit and CM-DiI positive) in the bone marrow was determined by flow cytometry 24 h after intravenous injection. Flow cytometry plots of (B) a non-injected control, (C) a positive control, (D) anti-CXCR4-treated mice and (E) anti-SDF-1-treated mice reveals only exogenous HSC in the positive control; no exogenous HSC could be detected in the bone marrow of anti-CXCR4- or anti-SDF-1-treated mice.

Mentions: To prove the efficacy of recSDF-1 as well as the neutralizing antibodies against SDF-1 and CXCR4, in vitro migration assays were performed. As depicted in Figure 3A, the medium supplemented with recSDF-1 resulted in an 8-fold increase of HSC migration compared to the medium alone. Adding anti-SDF-1 to the assay or pre-incubating the HSC with anti-CXCR4 resulted in reduced migration of HSC cells by 65 and 40%, respectively.


Haematopoietic stem cell migration to the ischemic damaged kidney is not altered by manipulating the SDF-1/CXCR4-axis.

Stroo I, Stokman G, Teske GJ, Florquin S, Leemans JC - Nephrol. Dial. Transplant. (2009)

Neutralizing SDF-1 and CXCR4 antibodies inhibit migration of HSC towards recSDF-1 and the bone marrow. (A) In an in vitro migration assay, the amount of migrated CM-DiI-labelled HSC from the upper to the lower compartment was determined as a percentage of the input. After 2 h at 37°C, 1.4% passive (control) migration of HSC was observed. Addition of 200 ng/mL recSDF-1 to the medium in the lower compartment increased HSC migration 8-fold. Neutralizing SDF-1 in the lower compartment or neutralizing HSC-associated CXCR4 in the upper compartment resulted in a 65% and 40% reduction of recSDF-1-induced migration, respectively. All experiments were performed in triplicate, bars represent mean ± SD, n = 2. (B–E) In an in vivo migration assay, the percentage of exogenous HSC (i.e. c-kit and CM-DiI positive) in the bone marrow was determined by flow cytometry 24 h after intravenous injection. Flow cytometry plots of (B) a non-injected control, (C) a positive control, (D) anti-CXCR4-treated mice and (E) anti-SDF-1-treated mice reveals only exogenous HSC in the positive control; no exogenous HSC could be detected in the bone marrow of anti-CXCR4- or anti-SDF-1-treated mice.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC2698094&req=5

Figure 3: Neutralizing SDF-1 and CXCR4 antibodies inhibit migration of HSC towards recSDF-1 and the bone marrow. (A) In an in vitro migration assay, the amount of migrated CM-DiI-labelled HSC from the upper to the lower compartment was determined as a percentage of the input. After 2 h at 37°C, 1.4% passive (control) migration of HSC was observed. Addition of 200 ng/mL recSDF-1 to the medium in the lower compartment increased HSC migration 8-fold. Neutralizing SDF-1 in the lower compartment or neutralizing HSC-associated CXCR4 in the upper compartment resulted in a 65% and 40% reduction of recSDF-1-induced migration, respectively. All experiments were performed in triplicate, bars represent mean ± SD, n = 2. (B–E) In an in vivo migration assay, the percentage of exogenous HSC (i.e. c-kit and CM-DiI positive) in the bone marrow was determined by flow cytometry 24 h after intravenous injection. Flow cytometry plots of (B) a non-injected control, (C) a positive control, (D) anti-CXCR4-treated mice and (E) anti-SDF-1-treated mice reveals only exogenous HSC in the positive control; no exogenous HSC could be detected in the bone marrow of anti-CXCR4- or anti-SDF-1-treated mice.
Mentions: To prove the efficacy of recSDF-1 as well as the neutralizing antibodies against SDF-1 and CXCR4, in vitro migration assays were performed. As depicted in Figure 3A, the medium supplemented with recSDF-1 resulted in an 8-fold increase of HSC migration compared to the medium alone. Adding anti-SDF-1 to the assay or pre-incubating the HSC with anti-CXCR4 resulted in reduced migration of HSC cells by 65 and 40%, respectively.

Bottom Line: Importantly, the amount of HSC in the ischemic kidney was markedly higher compared to the contralateral kidney.Neutralizing endogenous SDF-1 or HSC-associated CXCR4 did not prevent the migration of HSC.In conclusion, systemically administered HSC preferentially migrate to the ischemic injured kidney.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. I.Stroo@amc.uva.nl

ABSTRACT

Background: Haematopoietic stem cells (HSC) have been shown to migrate to the ischemic kidney. The factors that regulate the trafficking of HSC to the ischemic damaged kidney are not fully understood. The stromal cell-derived factor-1 (SDF-1)/CXCR4-axis has been identified as the central signalling axis regulating trafficking of HSC to the bone marrow. Therefore, we hypothesized that SDF-1/CXCR4 interactions are implicated in the migration of HSC to the injured kidney.

Methods: HSC were isolated from mouse bone marrow and labelled with a cell tracker. Acceptor mice were subjected to unilateral ischemia and received HSC intravenously directly after reperfusion. In addition, in separate groups of acceptor mice, endogenous SDF-1 or HSC-associated CXCR4 was blocked or kidneys were injected with SDF-1.

Results: Exogenous HSC could be detected in the tubules and interstitium of the kidney 24 h after ischemic injury. Importantly, the amount of HSC in the ischemic kidney was markedly higher compared to the contralateral kidney. Neutralizing endogenous SDF-1 or HSC-associated CXCR4 did not prevent the migration of HSC. No increase in the number of labelled HSC could be observed after local administration of SDF-1, as was also determined in bilateral kidney ischemia.

Conclusion: In conclusion, systemically administered HSC preferentially migrate to the ischemic injured kidney. This migration could not be prevented by blocking the SDF-1/CXCR4-axis or increased after local administration of SDF-1.

Show MeSH
Related in: MedlinePlus