scholarly journals Phagocyte Chemoattraction Is Induced through the Mcp-1–Ccr2 Axis during Efferocytosis

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3115
Author(s):  
Sang-Ah Lee ◽  
Deokhwan Kim ◽  
Chanhyuk Min ◽  
Byeongjin Moon ◽  
Juyeon Lee ◽  
...  

Apoptotic cells generated during development and for tissue homeostasis are swiftly and continuously removed by phagocytes via a process called efferocytosis. Efficient efferocytosis can be achieved via transcriptional modulation in phagocytes that have engulfed apoptotic cells. However, such modulation and its effect on efferocytosis are not completely understood. Here, we report that phagocytes are recruited to apoptotic cells being cleared through the Mcp-1–Ccr2 axis, which facilitates clearance of apoptotic cells. We identified Mcp-1 as a modulated transcript using a microarray and found that Mcp-1 secretion was augmented in phagocytes engulfing apoptotic cells. This augmented Mcp-1 secretion was impaired by blocking phagolysosomal degradation of apoptotic cells. Conditioned medium from wild type (WT) phagocytes promoted cell migration, but that from Mcp-1−/− phagocytes did not. In addition, blockade of Ccr2, the receptor for Mcp-1, abrogated cell migration to conditioned medium from phagocytes incubated with apoptotic cells. The intrinsic efferocytosis activity of Mcp-1−/− and Ccr2−/− phagocytes was unaltered, but clearance of apoptotic cells was less efficient in the peritoneum of Mcp-1−/− and Ccr2−/− mice than in that of WT mice because fewer Ccr2-positive phagocytes were recruited. Taken together, our findings demonstrate a mechanism by which not only apoptotic cells but also phagocytes induce chemoattraction to recruit phagocytes to sites where apoptotic cells are cleared for efficient efferocytosis.

Biomolecules ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 737 ◽  
Author(s):  
Zsolt Sarang ◽  
Tibor Sághy ◽  
Zsófia Budai ◽  
László Ujlaky-Nagy ◽  
Judit Bedekovics ◽  
...  

Apoptosis and the proper clearance of apoptotic cells play a central role in maintaining tissue homeostasis. Previous work in our laboratory has shown that when a high number of cells enters apoptosis in a tissue, the macrophages that engulf them produce retinoids to enhance their own phagocytic capacity by upregulating several phagocytic genes. Our data indicated that these retinoids might be dihydroretinoids, which are products of the retinol saturase (RetSat) pathway. In the present study, the efferocytosis of RetSat-null mice was investigated. We show that among the retinoid-sensitive phagocytic genes, only transglutaminase 2 responded in macrophages and in differentiating monocytes to dihydroretinol. Administration of dihydroretinol did not affect the expression of the tested genes differently between differentiating wild type and RetSat-null monocytes, despite the fact that the expression of RetSat was induced. However, in the absence of RetSat, the expression of numerous differentiation-related genes was altered. Among these, impaired production of MFG-E8, a protein that bridges apoptotic cells to the αvβ3/β5 integrin receptors of macrophages, resulted in impaired efferocytosis, very likely causing the development of mild autoimmunity in aged female mice. Our data indicate that RetSat affects monocyte/macrophage differentiation independently of its capability to produce dihydroretinol at this stage.


2003 ◽  
Vol 284 (3) ◽  
pp. G490-G498 ◽  
Author(s):  
Courtney W. Houchen ◽  
Mark A. Sturmoski ◽  
Shrikant Anant ◽  
Richard M. Breyer ◽  
William F. Stenson

The biological activities of PGE2 are mediated through EP receptors (EP1–EP4), plasma membrane G protein-coupled receptors that differ in ligand binding and signal-transduction pathways. We investigated gastrointestinal EP2 receptor expression in adult mice before and after radiation injury and evaluated intestinal stem cell survival and crypt epithelial apoptosis after radiation injury in EP2 null mice. EP2 was expressed throughout the gut. Intestinal EP2 mRNA increased fivefold after γ-irradiation. Crypt survival was diminished in EP2 −/− mice (4.06 crypts/cross section) compared with wild-type littermates (8.15 crypts/cross section). Radiation-induced apoptosis was significantly increased in EP2 −/− mice compared with wild-type littermates. Apoptosis was 1.6-fold higher in EP2 −/− mice (5.9 apoptotic cells/crypt) than in wild-type mice (3.5 apoptotic cells/crypt). The EP2receptor is expressed in mouse gastrointestinal epithelial cells and is upregulated following radiation injury. The effects of PGE2on both crypt epithelial apoptosis and intestinal crypt stem cell survival are mediated through the EP2 receptor.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Erbin Dai ◽  
Dana McIvor ◽  
Liying Liu ◽  
Ganesh Munaswamy-Ramanujam ◽  
Yunming Sun ◽  
...  

Background: Chemokines bind to glycosaminoglycans (GAGs) forming gradients that direct inflammatory cell invasion. The viral chemokine modulating protein (CMP), MT-7 binds the C terminal, GAG-binding domain of chemokines and has been previously reported to significantly reduce cell invasion and plaque growth in rat aortic and renal transplant models. Two other viral CMPs, M-T1 and M3 CMPs bind the N terminal domain of chemokines that bind to cell surface receptors. To determine the role of CC chemokine receptor 2 (CCR2) and GAGs for M-T7 anti-inflammatory activity, effects of M-T7 on plaque growth were assessed after mouse CCR2 deficient (CCR2−/−) or GAG deficient (NDST1−/−) aortic allograft transplant. Mononuclear cell migration in response to MCP-1 or RANTES into mouse ascites was also tested. Active sites necessary for M-T7 inhibition of chemokine function and monocyte activation, were assessed by infusion of in the mouse cell migration and human monocyte membrane fluidity assays. Results: M-T7 significantly reduced cell migration and intimal hyperplasia in wild type CCR2+/+ (p<0.009), and CCR2−/− aortic transplants (p<0.026). M-T1 and M3 inhibited cell invasion and plaque in CCR2+/+, but not CCR2−/− mice. M-T7 inhibited plaque growth and CC chemokine (MCP-1 and RANTES)-induced cell migration in wild type mice (P<0.01), but not in NDST1−/− mice (P=0.34). Selected M-T7 point mutations Ty (Y)46A, and Val (V) 210A no longer block chemokine-induced cell migration nor monocyte activation, whereas Asn (N) 40, Asn (N) 63 and Val (V)129 retain inhibitory activity. Conclusions: M-T7 but not M-T1 nor M3, blocks cell migration and plaque growth in CCR2 deficient (CCR2−/−) mouse aortic transplant models. M-T7 loses the ability to block cell migration and plaque growth in NDST1−/−, GAG (heparan sulfate) deficient mice. Point mutations Tyr46 and Val 210 lack inflammatory for mouse and human inflammatory monocyte responses indicating that these amino acid residues on the M-T7 CMP protein are required for inhibitory activity.


Development ◽  
1991 ◽  
Vol 113 (3) ◽  
pp. 797-803 ◽  
Author(s):  
M.J. Stern ◽  
H.R. Horvitz

In wild-type Caenorhabditis elegans hermaphrodites, two bilaterally symmetric sex myoblasts (SMs) migrate anteriorly to flank the precise center of the gonad, where they divide to generate the muscles required for egg laying (J. E. Sulston and H. R. Horvitz (1977) Devl Biol. 56, 110–156). Although this migration is largely independent of the gonad, a signal from the gonad attracts the SMs to their precise final positions (J. H. Thomas, M. J. Stern and H. R. Horvitz (1990) Cell 62, 1041–1052). Here we show that mutations in either of two genes, egl-15 and egl-17, cause the premature termination of the migrations of the SMs. This incomplete migration is caused by the repulsion of the SMs by the same cells in the somatic gonad that are the source of the attractive signal in wild-type animals.


2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Zhongming Chen

Background: Cell migration is an important step involved in heart regeneration and many cardiovascular diseases. However, cell migration dynamics in vivo is poorly understood due to the challenges from mammal hearts, which are opaque and fast beating, and thus individual cardiac cells cannot be imaged or tracked. Aims: In this study, cell migration dynamics in the heart is recorded with a novel strategy, in which fluorescence protein-tagged collagen is secreted from cells and deposited into extracellular matrix, forming visible trails when cells are moving in tissues. As a proof-of-concept, transplanted migration dynamics of cardiac progenitor cells in mouse hearts were investaged. Methods: Stable cell lines expressing mCherry-tagged type I collagen were generated from isolated cardiac progenitor cells, ABCG2 + CD45 - CD31 - cells (side populations), or c-kit + CD45 - CD31 - cells (c-kit + CPCs). The cell migration dynamics were monitored and measured based on the cell trails after cell transplantation into mouse tissues. Results: The stable cell lines form red cell trails both in vitro and in vivo (Fig. 1A & 1B, Green: GFP; Red: mCherry-collagen I, Blue: DAPI, bar: 50 microns). In culture dishes, the cells form visible cell trails of fluorescence protein. The cell moving directions are random, with a speed of 288 +/- 79 microns/day (side populations, n=3) or 143 +/-37 microns/day (c-kit + CPCs, n=3). After transplantation into wild-type mouse hearts, the cells form highly tortuous trails along the gaps between the heart muscle fibers. Angle between a cell trail and a muscle fiber is 16+/-16 degree (n=3). Side populations migrate twice as fast as c-kit+ CPCs in the heart (16.0 +/-8.7 microns/day vs. 8.1+/-0.0 microns/day, n=3, respectively), 18 time slower than the respective speeds in vitro . Additionally, side populations migrate significantly faster in the heart than in the skeletal muscles (26.4+/-5.8 microns/day, n=3). The side populations move significantly faster in immunodeficient mouse hearts (36.7+/-13.3 microns/day, n=3, typically used for studying cell therapies) than in wild-type mouse hearts. Conclusion: For the first time, cell migration dynamics in living hearts is monitored and examined with genetically modified cell lines. This study may greatly advance the fields of cardiovascular biology.


2001 ◽  
Vol 281 (1) ◽  
pp. C123-C132 ◽  
Author(s):  
Melissa A. Dechert ◽  
Jennifer M. Holder ◽  
William T. Gerthoffer

Cell migration contributes to many physiological processes and requires dynamic changes in the cytoskeleton. These migration-dependent cytoskeletal changes are partly mediated by p21-activated protein kinases (PAKs). At least four closely related isoforms, PAK1, PAK2, PAK3, and PAK4, exist in mammalian cells. In smooth muscle cells, little is known about the expression, activation, or ability of PAKs to regulate migration. Our study revealed the existence of three PAK isoforms in cultured tracheal smooth muscle cells (TSMCs). Additionally, we constructed adenoviral vectors encoding wild type and a catalytically inactive PAK1 mutant to investigate PAK activation and its role in TSMC migration. Stimulation of TSMCs with platelet-derived growth factor (PDGF) increased the activity of PAK1 over time. Overexpression of mutant PAK1 blocked PDGF-induced chemotactic cell migration. Phosphorylation of p38 mitogen-activated protein kinase (MAPK) in cells overexpressing wild-type PAK1 was similar to vector controls; however, p38 MAPK phosphorylation was severely reduced by overexpression of the PAK1 mutant. Collectively, these results suggest a role for PAK1 in chemotactic TSMC migration that involves catalytic activity and may require signaling to p38 MAPK among other pathways.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
D B Nugroho ◽  
K Ikeda ◽  
A Haryono ◽  
P Rinastiti ◽  
A J Barinda ◽  
...  

Abstract Background Advanced age is a significant risk factor for cardiovascular diseases such as hypertension and cardiac hypertrophy. The vascular system forms an essential component of cardiac tissue, to provide routes for circulation and transportation of nutrients and oxygen throughout the cardiac muscle. In addition to its function in vascular biology such as vasodilation and neovessel formation, endothelial cell (EC) also provides many secreted angiocrine factors that are crucially involved in maintaining tissue homeostasis. Ageing induces cellular senescence in various cells including EC. Senescent cells produce senescence-messaging secretomes that have deleterious effects on the tissue microenvironment, referred to as the senescence-associated secretory phenotype (SASP). Because of the crucial roles of EC in tissue homeostasis, EC senescence is presumed to play significant roles in age-related cardiac dysfunction, however, whether and the mechanism by which EC senescence affects age-related cardiac dysfunction remains to be elucidated. Purpose We aimed to investigate the role of senescent ECs in cardiac hypertrophy and heart function. Methods To investigate a contribution of senescent EC in age-related cardiac tissue dysfunction in vivo, we generated EC-specific progeroid mice that overexpress the dominant negative form of telomeric repeat-binding factor 2 (TRF2), which play a central role in the protection of chromosome ends, under the control of the vascular endothelial cadherin promoter (VEcad-TRF2DN-Tg). To induce pathological cardiac remodeling, Transverse Aortic Constriction (TAC) was performed in mice at the age of 10–12 weeks old. Cardiac function was assessed using fractional shortening percentage and ejection fraction measured with echocardiography every week until sacrifice day. Mice were sacrificed 4 weeks after TAC, heart tissue was collected for histological analysis, cardiac morphometry analysis, gene expression and protein expression analysis. In vitro, H9C2 rat cardiomyoblast cells were incubated with conditioned medium derived from control or senescent EC in the presence or absence of angiotensin II to induce cardiac hypertrophy. Results The serial echocardiographic analysis after TAC revealed the exacerbated LV dysfunction in VEcad-TRF2DN-Tg compared to that in wild-type mice. Morphometric and histological analysis 4 weeks after TAC showed increased heart weight and aggravated cardiac fibrosis in VEcad-TRF2DN-Tg mice. In vitro studies demonstrated that conditioned medium derived from senescent ECs enhanced cardiomyocyte hypertrophy in H9C2 cells. Of note, we found that treatment with Y2762, a Rho Kinase inhibitor, canceled the exacerbated cardiac hypertrophy caused by endothelial SASP. Conclusion These findings demonstrate for the first time that senescent ECs play causative roles in age-related cardiac disorders through the SASP, potentially by activating Rho-ROCK pathway in cardiomyocytes.


2010 ◽  
Vol 2010 ◽  
pp. 1-18 ◽  
Author(s):  
M. R. Griffiths ◽  
P. Gasque ◽  
J. W. Neal

Neurons and glia respond to acute injury by participating in the CNS innate immune response. This involves the recognition and clearance of “not self ” pathogens and “altered self ” apoptotic cells. Phagocytic receptors (CD14, CD36, TLR–4) clear “not self” pathogens; neurons and glia express “death signals” to initiate apoptosis in T cells.The complement opsonins C1q, C3, and iC3b facilitate the clearance of apoptotic cells by interacting with CR3 and CR4 receptors. Apoptotic cells are also cleared by the scavenger receptors CD14, Prs-R, TREM expressed by glia. Serpins also expressed by glia counter the neurotoxic effects of thrombin and other systemic proteins that gain entry to the CNS following injury. Complement pathway and T cell activation are both regulated by complement regulatory proteins expressed by glia and neurons. CD200 and CD47 are NIRegs expressed by neurons as “don't eat me” signals and they inhibit microglial activity preventing host cell attack. Neural stem cells regulate T cell activation, increase the Treg population, and suppress proinflammatory cytokine expression. Stem cells also interact with the chemoattractants C3a, C5a, SDF-1, and thrombin to promote stem cell migration into damaged tissue to support tissue homeostasis.


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