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Sphingosine 1-Phosphate Receptor 2 and 3 Mediate Bone Marrow-Derived Monocyte/Macrophage Motility in Cholestatic Liver Injury in Mice.

Yang L, Han Z, Tian L, Mai P, Zhang Y, Wang L, Li L - Sci Rep (2015)

Bottom Line: The results showed that S1PR1-3 were all expressed in BMMs. S1P exerted a powerful migratory action on BMMs via S1PR2 and S1PR3.Furthermore, PTX and LY-294002 (PI3K inhibitor) prevented S1PR2/3-mediated BMM migration, and Rac1 activation by S1P was inhibited by JTE-013, CAY-10444 or LY294002.In conclusion, S1P/S1PR2/3 system mediates BMM motility by PTX-PI3K-Rac1 signaling pathway, which provides new compelling information on the role of S1P/S1PR in liver injury and opens new perspectives for the pharmacological treatment of hepatic fibrosis.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell Biology, Municipal Laboratory for Liver Protection and Regulation of Regeneration, Capital Medical University, Beijing 100069, China.

ABSTRACT
Sphingosine 1-phosphate (S1P)/S1P receptor (S1PR) system has been implicated in the pathological process of liver injury. This study was designed to evaluate the effects of S1P/S1PR on bone marrow-derived monocyte/macrophage (BMM) migration in mouse models of cholestatic liver injury, and identify the signaling pathway underlying this process. S1PR1-3 expression in BMM was characterized by immunofluorescence, RT-PCR and Western blot. Cell migration was determined in Boyden chambers. In vivo, the chimera mice, which received BM transplants from EGFP-transgenic mice, received an operation of bile duct ligation (BDL) to induce liver injury with the administration of S1PR2/3 antagonists. The results showed that S1PR1-3 were all expressed in BMMs. S1P exerted a powerful migratory action on BMMs via S1PR2 and S1PR3. Furthermore, PTX and LY-294002 (PI3K inhibitor) prevented S1PR2/3-mediated BMM migration, and Rac1 activation by S1P was inhibited by JTE-013, CAY-10444 or LY294002. Administration of S1PR2/3 antagonists in vivo significantly reduced BMM recruitment in BDL-treated mice, and attenuated hepatic inflammation and fibrosis. In conclusion, S1P/S1PR2/3 system mediates BMM motility by PTX-PI3K-Rac1 signaling pathway, which provides new compelling information on the role of S1P/S1PR in liver injury and opens new perspectives for the pharmacological treatment of hepatic fibrosis.

No MeSH data available.


Related in: MedlinePlus

S1PR2/3 antagonist reduces BMM recruitment in cholestatic liver injury.(a) Representative confocal images to track the macrophages (F4/80+, red) of BM origin (EGFP+, green) in the BDL-treated livers. DAPI was used to visualize nuclei (blue). Inset: representative images for Sham-treated livers. Scale bars, 50 μm. (b) The proportion of BMMs (numbers of cells with yellow color/red color), was measured by Image-Pro Plus. (c) Flow-cytometric analysis of the non-parenchymal cells (NPC) in the liver for F4/80. (d) The proportion of monocytes/macrophages from BM was measured by FACS Diva 4.1. *P < 0.05 vs. Control. #P < 0.05 vs. BDL group (n = 7 per group).
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f4: S1PR2/3 antagonist reduces BMM recruitment in cholestatic liver injury.(a) Representative confocal images to track the macrophages (F4/80+, red) of BM origin (EGFP+, green) in the BDL-treated livers. DAPI was used to visualize nuclei (blue). Inset: representative images for Sham-treated livers. Scale bars, 50 μm. (b) The proportion of BMMs (numbers of cells with yellow color/red color), was measured by Image-Pro Plus. (c) Flow-cytometric analysis of the non-parenchymal cells (NPC) in the liver for F4/80. (d) The proportion of monocytes/macrophages from BM was measured by FACS Diva 4.1. *P < 0.05 vs. Control. #P < 0.05 vs. BDL group (n = 7 per group).

Mentions: To investigate the potential role of S1PR2 and S1PR3 in BMM migration during cholestatic liver injury, we performed an EGPF-positive BM cell transplantation experiment followed by BDL-induced liver injury with the administration of JTE-013 or CAY-10444. Then we performed immunofluorescent staining for F4/80, which is a representative marker of mouse macrophages. The results showed that a large amount of EGFP-positive cells in the fibrotic areas were also positive for F4/80, implying that BMM was recruited to the injured liver (Fig. 4a). Strikingly, JTE-013 or CAY-10444 reduced the population of BMM in the fibrotic liver compared with that in BDL-treated mice (Fig. 4b).


Sphingosine 1-Phosphate Receptor 2 and 3 Mediate Bone Marrow-Derived Monocyte/Macrophage Motility in Cholestatic Liver Injury in Mice.

Yang L, Han Z, Tian L, Mai P, Zhang Y, Wang L, Li L - Sci Rep (2015)

S1PR2/3 antagonist reduces BMM recruitment in cholestatic liver injury.(a) Representative confocal images to track the macrophages (F4/80+, red) of BM origin (EGFP+, green) in the BDL-treated livers. DAPI was used to visualize nuclei (blue). Inset: representative images for Sham-treated livers. Scale bars, 50 μm. (b) The proportion of BMMs (numbers of cells with yellow color/red color), was measured by Image-Pro Plus. (c) Flow-cytometric analysis of the non-parenchymal cells (NPC) in the liver for F4/80. (d) The proportion of monocytes/macrophages from BM was measured by FACS Diva 4.1. *P < 0.05 vs. Control. #P < 0.05 vs. BDL group (n = 7 per group).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4555045&req=5

f4: S1PR2/3 antagonist reduces BMM recruitment in cholestatic liver injury.(a) Representative confocal images to track the macrophages (F4/80+, red) of BM origin (EGFP+, green) in the BDL-treated livers. DAPI was used to visualize nuclei (blue). Inset: representative images for Sham-treated livers. Scale bars, 50 μm. (b) The proportion of BMMs (numbers of cells with yellow color/red color), was measured by Image-Pro Plus. (c) Flow-cytometric analysis of the non-parenchymal cells (NPC) in the liver for F4/80. (d) The proportion of monocytes/macrophages from BM was measured by FACS Diva 4.1. *P < 0.05 vs. Control. #P < 0.05 vs. BDL group (n = 7 per group).
Mentions: To investigate the potential role of S1PR2 and S1PR3 in BMM migration during cholestatic liver injury, we performed an EGPF-positive BM cell transplantation experiment followed by BDL-induced liver injury with the administration of JTE-013 or CAY-10444. Then we performed immunofluorescent staining for F4/80, which is a representative marker of mouse macrophages. The results showed that a large amount of EGFP-positive cells in the fibrotic areas were also positive for F4/80, implying that BMM was recruited to the injured liver (Fig. 4a). Strikingly, JTE-013 or CAY-10444 reduced the population of BMM in the fibrotic liver compared with that in BDL-treated mice (Fig. 4b).

Bottom Line: The results showed that S1PR1-3 were all expressed in BMMs. S1P exerted a powerful migratory action on BMMs via S1PR2 and S1PR3.Furthermore, PTX and LY-294002 (PI3K inhibitor) prevented S1PR2/3-mediated BMM migration, and Rac1 activation by S1P was inhibited by JTE-013, CAY-10444 or LY294002.In conclusion, S1P/S1PR2/3 system mediates BMM motility by PTX-PI3K-Rac1 signaling pathway, which provides new compelling information on the role of S1P/S1PR in liver injury and opens new perspectives for the pharmacological treatment of hepatic fibrosis.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell Biology, Municipal Laboratory for Liver Protection and Regulation of Regeneration, Capital Medical University, Beijing 100069, China.

ABSTRACT
Sphingosine 1-phosphate (S1P)/S1P receptor (S1PR) system has been implicated in the pathological process of liver injury. This study was designed to evaluate the effects of S1P/S1PR on bone marrow-derived monocyte/macrophage (BMM) migration in mouse models of cholestatic liver injury, and identify the signaling pathway underlying this process. S1PR1-3 expression in BMM was characterized by immunofluorescence, RT-PCR and Western blot. Cell migration was determined in Boyden chambers. In vivo, the chimera mice, which received BM transplants from EGFP-transgenic mice, received an operation of bile duct ligation (BDL) to induce liver injury with the administration of S1PR2/3 antagonists. The results showed that S1PR1-3 were all expressed in BMMs. S1P exerted a powerful migratory action on BMMs via S1PR2 and S1PR3. Furthermore, PTX and LY-294002 (PI3K inhibitor) prevented S1PR2/3-mediated BMM migration, and Rac1 activation by S1P was inhibited by JTE-013, CAY-10444 or LY294002. Administration of S1PR2/3 antagonists in vivo significantly reduced BMM recruitment in BDL-treated mice, and attenuated hepatic inflammation and fibrosis. In conclusion, S1P/S1PR2/3 system mediates BMM motility by PTX-PI3K-Rac1 signaling pathway, which provides new compelling information on the role of S1P/S1PR in liver injury and opens new perspectives for the pharmacological treatment of hepatic fibrosis.

No MeSH data available.


Related in: MedlinePlus