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Cellular basis of tissue regeneration by omentum.

Shah S, Lowery E, Braun RK, Martin A, Huang N, Medina M, Sethupathi P, Seki Y, Takami M, Byrne K, Wigfield C, Love RB, Iwashima M - PLoS ONE (2012)

Bottom Line: To understand the mechanism of tissue repair support by the omentum in more detail, we analyzed the cell subsets derived from the omentum on immune and inflammatory responses.Our data demonstrate that the omentum contains at least two groups of cells that support tissue repair, immunomodulatory myeloid derived suppressor cells and omnipotent stem cells that are indistinguishable from mesenchymal stem cells.Based on these data, we propose that the omentum is a designated organ for tissue repair and healing in response to foreign invasion and tissue damage.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Chicago, Illinois, United States of America.

ABSTRACT
The omentum is a sheet-like tissue attached to the greater curvature of the stomach and contains secondary lymphoid organs called milky spots. The omentum has been used for its healing potential for over 100 years by transposing the omental pedicle to injured organs (omental transposition), but the mechanism by which omentum helps the healing process of damaged tissues is not well understood. Omental transposition promotes expansion of pancreatic islets, hepatocytes, embryonic kidney, and neurons. Omental cells (OCs) can be activated by foreign bodies in vivo. Once activated, they become a rich source for growth factors and express pluripotent stem cell markers. Moreover, OCs become engrafted in injured tissues suggesting that they might function as stem cells.Omentum consists of a variety of phenotypically and functionally distinctive cells. To understand the mechanism of tissue repair support by the omentum in more detail, we analyzed the cell subsets derived from the omentum on immune and inflammatory responses. Our data demonstrate that the omentum contains at least two groups of cells that support tissue repair, immunomodulatory myeloid derived suppressor cells and omnipotent stem cells that are indistinguishable from mesenchymal stem cells. Based on these data, we propose that the omentum is a designated organ for tissue repair and healing in response to foreign invasion and tissue damage.

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Effect of omentum cells on inflammation in the bleomycin induced mouse lung injury model.Saline or bleomycin was given intra-tracheally to C57BL/6 mice. 4 hours later, mice received i.p. injections of omentum cells (1×106 cells) or saline alone. (a) H&E staining of lung sections from mice sacrificed 7 days after bleomycin injury. Upper panels (×10), Lower panels (×20). (b) Quantification of inflammation by a volume density of lesion analysis. (c, d) Total cell numbers and percentages of T cell subsets in the bronchoalveolar lavage fluid (BAL) 7 days after bleomycin instillation. (e, f) Cytokine analysis on BAL samples 3 days after bleomycin instillation. * denotes for p<0.05.
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pone-0038368-g001: Effect of omentum cells on inflammation in the bleomycin induced mouse lung injury model.Saline or bleomycin was given intra-tracheally to C57BL/6 mice. 4 hours later, mice received i.p. injections of omentum cells (1×106 cells) or saline alone. (a) H&E staining of lung sections from mice sacrificed 7 days after bleomycin injury. Upper panels (×10), Lower panels (×20). (b) Quantification of inflammation by a volume density of lesion analysis. (c, d) Total cell numbers and percentages of T cell subsets in the bronchoalveolar lavage fluid (BAL) 7 days after bleomycin instillation. (e, f) Cytokine analysis on BAL samples 3 days after bleomycin instillation. * denotes for p<0.05.

Mentions: We tested the effect of omentum cells in tissue repair by using an acute lung injury model with intratracheal (IT) injection of bleomycin [27]. To collect sufficient numbers of omentum cells, the omentum was expanded in mice by intraperitoneal (i.p.) injection of polyacrylamide beads as reported for rats [23]. Seven days after injection, both the greater and lesser omentum were expanded in mice as in rats (Fig. S1). Single cell suspensions were made from expanded omentum, and cells were adoptively transferred into mice that were administered with bleomycin (Fig. 1). Compared to mice injected with bleomycin alone, mice that received adoptive transfer of omentum cells showed a significant reduction in the level of tissue inflammation and cellular accumulation in the lung (Fig. 1a). Only a few inflammatory areas (arrows) in the parenchyma were apparent. Morphometric analysis by volume density of lesion and the number of cells detected in bronchoalveolar lavage fluid (BAL) revealed a significant reduction in the extent of inflammation in the lung (Fig. 1b and c). All T cell subsets, CD4, CD8, and γδ T cells in BAL were reduced (Fig. 1d). Cytokine profiles in BAL showed that injection of omentum cells reduced the levels of pro-inflammatory cytokines such as IL-6 and IL-12 p40 (Fig. 1e). In addition, the concentration of CCL2 (MCP-1) and G-CSF was significantly reduced in the omentum cell-treated group compared to the bleomycin only group (Fig. 1f). Together, the data suggest that transferred omentum ameliorates bleomycin-induced lung injury either by reduction of immune/inflammatory responses and/or accelerated recovery of the damaged lung.


Cellular basis of tissue regeneration by omentum.

Shah S, Lowery E, Braun RK, Martin A, Huang N, Medina M, Sethupathi P, Seki Y, Takami M, Byrne K, Wigfield C, Love RB, Iwashima M - PLoS ONE (2012)

Effect of omentum cells on inflammation in the bleomycin induced mouse lung injury model.Saline or bleomycin was given intra-tracheally to C57BL/6 mice. 4 hours later, mice received i.p. injections of omentum cells (1×106 cells) or saline alone. (a) H&E staining of lung sections from mice sacrificed 7 days after bleomycin injury. Upper panels (×10), Lower panels (×20). (b) Quantification of inflammation by a volume density of lesion analysis. (c, d) Total cell numbers and percentages of T cell subsets in the bronchoalveolar lavage fluid (BAL) 7 days after bleomycin instillation. (e, f) Cytokine analysis on BAL samples 3 days after bleomycin instillation. * denotes for p<0.05.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3368844&req=5

pone-0038368-g001: Effect of omentum cells on inflammation in the bleomycin induced mouse lung injury model.Saline or bleomycin was given intra-tracheally to C57BL/6 mice. 4 hours later, mice received i.p. injections of omentum cells (1×106 cells) or saline alone. (a) H&E staining of lung sections from mice sacrificed 7 days after bleomycin injury. Upper panels (×10), Lower panels (×20). (b) Quantification of inflammation by a volume density of lesion analysis. (c, d) Total cell numbers and percentages of T cell subsets in the bronchoalveolar lavage fluid (BAL) 7 days after bleomycin instillation. (e, f) Cytokine analysis on BAL samples 3 days after bleomycin instillation. * denotes for p<0.05.
Mentions: We tested the effect of omentum cells in tissue repair by using an acute lung injury model with intratracheal (IT) injection of bleomycin [27]. To collect sufficient numbers of omentum cells, the omentum was expanded in mice by intraperitoneal (i.p.) injection of polyacrylamide beads as reported for rats [23]. Seven days after injection, both the greater and lesser omentum were expanded in mice as in rats (Fig. S1). Single cell suspensions were made from expanded omentum, and cells were adoptively transferred into mice that were administered with bleomycin (Fig. 1). Compared to mice injected with bleomycin alone, mice that received adoptive transfer of omentum cells showed a significant reduction in the level of tissue inflammation and cellular accumulation in the lung (Fig. 1a). Only a few inflammatory areas (arrows) in the parenchyma were apparent. Morphometric analysis by volume density of lesion and the number of cells detected in bronchoalveolar lavage fluid (BAL) revealed a significant reduction in the extent of inflammation in the lung (Fig. 1b and c). All T cell subsets, CD4, CD8, and γδ T cells in BAL were reduced (Fig. 1d). Cytokine profiles in BAL showed that injection of omentum cells reduced the levels of pro-inflammatory cytokines such as IL-6 and IL-12 p40 (Fig. 1e). In addition, the concentration of CCL2 (MCP-1) and G-CSF was significantly reduced in the omentum cell-treated group compared to the bleomycin only group (Fig. 1f). Together, the data suggest that transferred omentum ameliorates bleomycin-induced lung injury either by reduction of immune/inflammatory responses and/or accelerated recovery of the damaged lung.

Bottom Line: To understand the mechanism of tissue repair support by the omentum in more detail, we analyzed the cell subsets derived from the omentum on immune and inflammatory responses.Our data demonstrate that the omentum contains at least two groups of cells that support tissue repair, immunomodulatory myeloid derived suppressor cells and omnipotent stem cells that are indistinguishable from mesenchymal stem cells.Based on these data, we propose that the omentum is a designated organ for tissue repair and healing in response to foreign invasion and tissue damage.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Chicago, Illinois, United States of America.

ABSTRACT
The omentum is a sheet-like tissue attached to the greater curvature of the stomach and contains secondary lymphoid organs called milky spots. The omentum has been used for its healing potential for over 100 years by transposing the omental pedicle to injured organs (omental transposition), but the mechanism by which omentum helps the healing process of damaged tissues is not well understood. Omental transposition promotes expansion of pancreatic islets, hepatocytes, embryonic kidney, and neurons. Omental cells (OCs) can be activated by foreign bodies in vivo. Once activated, they become a rich source for growth factors and express pluripotent stem cell markers. Moreover, OCs become engrafted in injured tissues suggesting that they might function as stem cells.Omentum consists of a variety of phenotypically and functionally distinctive cells. To understand the mechanism of tissue repair support by the omentum in more detail, we analyzed the cell subsets derived from the omentum on immune and inflammatory responses. Our data demonstrate that the omentum contains at least two groups of cells that support tissue repair, immunomodulatory myeloid derived suppressor cells and omnipotent stem cells that are indistinguishable from mesenchymal stem cells. Based on these data, we propose that the omentum is a designated organ for tissue repair and healing in response to foreign invasion and tissue damage.

Show MeSH
Related in: MedlinePlus