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Quantification and localization of M2 macrophages in human kidneys with acute tubular injury.

Palmer MB, Vichot AA, Cantley LG, Moeckel GW - Int J Nephrol Renovasc Dis (2014)

Bottom Line: M2 macrophages, which are believed to be critical for wound healing, were found to localize close to the tubular basement membrane of injured proximal tubule cells.Ultra structural examination showed close adherence of macrophages to the basement membrane of injured tubular epithelial cells.We further speculate that macrophage-mediated repair may involve physical contact between the M2 macrophage and the injured tubular epithelial cell.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Yale University School of Medicine, New Haven, CT, USA.

ABSTRACT
This study addresses for the first time the question whether there is significant macrophage population in human kidney sections from patients with acute tubular injury (ATI). We examined therefore the interstitial macrophage population in human kidney tissue with biopsy-proven diagnosis of ATI, minimal change disease (MCD), and MCD with ATI. Kidney biopsies from patients with the above diagnoses were stained with antibodies directed against CD68 (general macrophage marker), CD163 (M2 marker), and HLA-DR (M1 marker) and their respective electron microscopy samples were evaluated for the presence of interstitial macrophages. Our study shows that patients with ATI have significantly increased numbers of interstitial CD68(+) macrophages, with an increase in both HLA-DR(+) M1 macrophages and CD163(+) M2 macrophages as compared to patients with MCD alone. Approximately 75% of macrophages were M2 (CD163(+)) whereas only 25% were M1 (HLA-DR(+)). M2 macrophages, which are believed to be critical for wound healing, were found to localize close to the tubular basement membrane of injured proximal tubule cells. Ultra structural examination showed close adherence of macrophages to the basement membrane of injured tubular epithelial cells. We conclude that macrophages accumulate around injured tubules following ATI and exhibit predominantly an M2 phenotype. We further speculate that macrophage-mediated repair may involve physical contact between the M2 macrophage and the injured tubular epithelial cell.

No MeSH data available.


Related in: MedlinePlus

Macrophage infiltration through the interstitium is directed towards injured tubules.Notes: (A) Monocyte (black arrow) in peritubular capillary. (B) Marginated monocyte (black arrow) adherent to the wall of a peritubular capillary. (C) Interstitial monocyte (macrophage) (black arrow) close to tubular epithelial cells. (D) Macrophage (black arrow) close to basement membrane of severely injured tubular epithelial cells.
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f3-ijnrd-7-415: Macrophage infiltration through the interstitium is directed towards injured tubules.Notes: (A) Monocyte (black arrow) in peritubular capillary. (B) Marginated monocyte (black arrow) adherent to the wall of a peritubular capillary. (C) Interstitial monocyte (macrophage) (black arrow) close to tubular epithelial cells. (D) Macrophage (black arrow) close to basement membrane of severely injured tubular epithelial cells.

Mentions: CD163+ M2 macrophages were seen throughout the interstitium and often directly adjacent to injured tubular epithelial cells (Figure 2A and B). HLA-DR positive M1 macrophages were more sparse and often randomly distributed in the interstitium without specific adherence to tubular basement membranes (Figure 2B and C). Ultra structural examination of the peritubular interstitium and peritubular capillaries in patients with ATI showed macrophages migrating from the capillary lumen to the adjacent interstitium (Figure 3A–C) and adhering to the basement membrane of injured tubular epithelial cells (Figure 3D). Thus, the physical adherence of macrophages to the basement membrane of injured tubular epithelial cells may be an important step in the M2-mediated repair process of ATI.


Quantification and localization of M2 macrophages in human kidneys with acute tubular injury.

Palmer MB, Vichot AA, Cantley LG, Moeckel GW - Int J Nephrol Renovasc Dis (2014)

Macrophage infiltration through the interstitium is directed towards injured tubules.Notes: (A) Monocyte (black arrow) in peritubular capillary. (B) Marginated monocyte (black arrow) adherent to the wall of a peritubular capillary. (C) Interstitial monocyte (macrophage) (black arrow) close to tubular epithelial cells. (D) Macrophage (black arrow) close to basement membrane of severely injured tubular epithelial cells.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4230184&req=5

f3-ijnrd-7-415: Macrophage infiltration through the interstitium is directed towards injured tubules.Notes: (A) Monocyte (black arrow) in peritubular capillary. (B) Marginated monocyte (black arrow) adherent to the wall of a peritubular capillary. (C) Interstitial monocyte (macrophage) (black arrow) close to tubular epithelial cells. (D) Macrophage (black arrow) close to basement membrane of severely injured tubular epithelial cells.
Mentions: CD163+ M2 macrophages were seen throughout the interstitium and often directly adjacent to injured tubular epithelial cells (Figure 2A and B). HLA-DR positive M1 macrophages were more sparse and often randomly distributed in the interstitium without specific adherence to tubular basement membranes (Figure 2B and C). Ultra structural examination of the peritubular interstitium and peritubular capillaries in patients with ATI showed macrophages migrating from the capillary lumen to the adjacent interstitium (Figure 3A–C) and adhering to the basement membrane of injured tubular epithelial cells (Figure 3D). Thus, the physical adherence of macrophages to the basement membrane of injured tubular epithelial cells may be an important step in the M2-mediated repair process of ATI.

Bottom Line: M2 macrophages, which are believed to be critical for wound healing, were found to localize close to the tubular basement membrane of injured proximal tubule cells.Ultra structural examination showed close adherence of macrophages to the basement membrane of injured tubular epithelial cells.We further speculate that macrophage-mediated repair may involve physical contact between the M2 macrophage and the injured tubular epithelial cell.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Yale University School of Medicine, New Haven, CT, USA.

ABSTRACT
This study addresses for the first time the question whether there is significant macrophage population in human kidney sections from patients with acute tubular injury (ATI). We examined therefore the interstitial macrophage population in human kidney tissue with biopsy-proven diagnosis of ATI, minimal change disease (MCD), and MCD with ATI. Kidney biopsies from patients with the above diagnoses were stained with antibodies directed against CD68 (general macrophage marker), CD163 (M2 marker), and HLA-DR (M1 marker) and their respective electron microscopy samples were evaluated for the presence of interstitial macrophages. Our study shows that patients with ATI have significantly increased numbers of interstitial CD68(+) macrophages, with an increase in both HLA-DR(+) M1 macrophages and CD163(+) M2 macrophages as compared to patients with MCD alone. Approximately 75% of macrophages were M2 (CD163(+)) whereas only 25% were M1 (HLA-DR(+)). M2 macrophages, which are believed to be critical for wound healing, were found to localize close to the tubular basement membrane of injured proximal tubule cells. Ultra structural examination showed close adherence of macrophages to the basement membrane of injured tubular epithelial cells. We conclude that macrophages accumulate around injured tubules following ATI and exhibit predominantly an M2 phenotype. We further speculate that macrophage-mediated repair may involve physical contact between the M2 macrophage and the injured tubular epithelial cell.

No MeSH data available.


Related in: MedlinePlus