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- Christoffersson, Gustaf, et al.
(författare)
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VEGF-A recruits a proangiogenic MMP-9-delivering neutrophil subset that induces angiogenesis in transplanted hypoxic tissue
- 2012
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 120:23, s. 4653-4662
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Tidskriftsartikel (refereegranskat)abstract
- Recruitment and retention of leukocytes at a site of blood vessel growth are crucial for proper angiogenesis and subsequent tissue perfusion. Although critical for many aspects of regenerative medicine, the mechanisms of leukocyte recruitment to and actions at sites of angiogenesis are not fully understood. In this study, we investigated the signals attracting leukocytes to avascular transplanted pancreatic islets and leukocyte actions at the engraftment site. Expression of the angiogenic stimulus VEGF-A by mouse pancreatic islets was elevated shortly after syngeneic transplantation to muscle. High levels of leukocytes, predominantly CD11b+/Gr-1+/CXCR4hi neutrophils, were observed at the site of engraftment, whereas VEGF-A–deficient islets recruited only half of the amount of leukocytes when transplanted. Acute VEGF-A exposure of muscle increased leukocyte extravasation but not the levels of SDF-1α. VEGF-A–recruited neutrophils expressed 10 times higher amounts of MMP-9 than neutrophils recruited to an inflammatory stimulus. Revascularization of islets transplanted to MMP-9–deficient mice was impaired because blood vessels initially failed to penetrate grafts, and after 2 weeks vascularity was still disturbed. This study demonstrates that VEGF-A recruits a proangiogenic circulating subset of CD11b+/Gr-1+ neutrophils that are CXCR4hi and deliver large amounts of the effector protein MMP-9, required for islet revascularization and functional integration after transplantation.
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| 2. |
- Pereira, Rafaela Vaz Sousa, et al.
(författare)
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Chlorite-Oxidized Oxyamylose (COAM) Has Antibacterial Activity and Positively Affects Skin Wound Healing
- 2022
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Ingår i: Journal of Inflammation Research. - : DOVE MEDICAL PRESS LTD. - 1178-7031. ; 15, s. 4995-5008
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To verify the antibacterial and immunomodulatory effects of the amylose derivative - chlorite-oxidized oxyamyloseMethods: In vitro antibacterial effects of COAM against opportunistic bacterial pathogens common to skin wounds, including Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA), were determined by cultivation methods. The effects of COAM on myeloid cell infiltration into full thickness skin wounds were investigated in wild-type and in transgenic CX3CR1-GFP mice.Results: On the basis of in vitro experiments, an antibacterial effect of COAM against Staphylococcus species including MRSA was confirmed. The minimum inhibitory concentration of COAM was determined as 2000 mu g/mL against these bacterial strains. Control full thickness skin wounds yielded maximal neutrophil influxes and no additive effect on neutrophil influx was observed following topical COAM-treatment. However, COAM administration increased local CX3CR1 macrophage counts at days 3 and 4 and induced a trend towards better wound healing.Conclusion: Aside from its known broad antiviral impact, COAM possesses in vitro antibacterial effects specifically against Grampositive opportunistic pathogens of the skin and modulates in vivo macrophage contents in mouse skin wounds.
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