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• W2037537803 abstract "Myofibroblasts play a central role in fibroproliferative airway remodeling in obliterative bronchiolitis (OB) after lung transplantation. The purpose of the study is to elucidate the mechanisms whereby matrix metalloproteinases (MMPs) contribute to myofibroblast-mediated allograft airway fibrosis. In an intrapulmonary tracheal transplant model of OB, broad-spectrum MMP inhibitors, SC080 and MMI270 reduced the number of myofibroblasts at day 28 without changing differentiation, proliferation or apoptosis of myofibroblasts or fibroblasts. Next, myofibroblasts in allograft airway fibrosis were demonstrated to be almost exclusively of extrapulmonary origin by analyzing RT1An positive myofibroblasts in an animal model combining orthotopic lung transplantation (from Lewis (RT1A|) to F1 (Brown-Norway (RT1An) × Lewis)) and intrapulmonary tracheal transplantation (from a Wister-Furth rat (RT1Au) into the transplanted Lewis-derived lung). Using peripheral blood mononuclear cells (PBMCs) that can differentiate into α -SMA positive myofibroblasts in vitro, we demonstrated their contribution to the myofibroblast population of allograft airway fibrosis in vivo using a fluorescence-labeling cell tracking system. Moreover, PBMC-derived fibroblast-like cells expressed high levels of MMP-9 and MMP-12 and their migration was inhibited by MMP inhibitors in a wound healing assay. In conclusion, MMP-dependent migration of PBMC-derived myofibroblast precursors is an important contributing mechanism to the development of allograft airway fibrosis. Myofibroblasts play a central role in fibroproliferative airway remodeling in obliterative bronchiolitis (OB) after lung transplantation. The purpose of the study is to elucidate the mechanisms whereby matrix metalloproteinases (MMPs) contribute to myofibroblast-mediated allograft airway fibrosis. In an intrapulmonary tracheal transplant model of OB, broad-spectrum MMP inhibitors, SC080 and MMI270 reduced the number of myofibroblasts at day 28 without changing differentiation, proliferation or apoptosis of myofibroblasts or fibroblasts. Next, myofibroblasts in allograft airway fibrosis were demonstrated to be almost exclusively of extrapulmonary origin by analyzing RT1An positive myofibroblasts in an animal model combining orthotopic lung transplantation (from Lewis (RT1A|) to F1 (Brown-Norway (RT1An) × Lewis)) and intrapulmonary tracheal transplantation (from a Wister-Furth rat (RT1Au) into the transplanted Lewis-derived lung). Using peripheral blood mononuclear cells (PBMCs) that can differentiate into α -SMA positive myofibroblasts in vitro, we demonstrated their contribution to the myofibroblast population of allograft airway fibrosis in vivo using a fluorescence-labeling cell tracking system. Moreover, PBMC-derived fibroblast-like cells expressed high levels of MMP-9 and MMP-12 and their migration was inhibited by MMP inhibitors in a wound healing assay. In conclusion, MMP-dependent migration of PBMC-derived myofibroblast precursors is an important contributing mechanism to the development of allograft airway fibrosis. Obliterative bronchiolitis (OB) is a fibroproliferative airway obliteration complicating transplanted pulmonary allografts (1Yousem SA Berry GJ Cagle PT et al.Revision of the 1990 working formulation for the classification of pulmonary allograft rejection: Lung Rejection Study Group..J Heart Lung Transplant. 1996; 15: 1-15PubMed Google Scholar). OB and its clinical correlate, bronchiolitis obliterans syndrome (BOS) affect about 50% of lung transplant recipients within 5 years of transplantation (2Trulock EP Christie JD Edwards LB et al.Registry of the International Society for Heart and Lung Transplantation: Twenty-fourth Official Adult Lung and Heart-Lung Transplantation Report-2007..J Heart Lung Transplant. 2007; 26: 782-795Abstract Full Text Full Text PDF PubMed Scopus (446) Google Scholar). Although OB/BOS has been generally viewed as a manifestation of chronic rejection, it is important to note that augmentation of immunosuppression is usually an ineffective treatment after the initiation of the fibrotic process (3Boehler A Estenne M Post-transplant bronchiolitis obliterans..Eur Respir J. 2003; 22: 1007-1018Crossref PubMed Scopus (177) Google Scholar). Thus, mechanisms other than immune responses alone must be considered. The myofibroblast plays a central role in fibroproliferative tissue remodeling (4Tomasek JJ Gabbiani G Hinz B Chaponnier C Brown RA Myofibroblasts and mechano-regulation of connective tissue remodelling..Nat Rev Mol Cell Biol. 2002; 3: 349-363Crossref PubMed Scopus (3228) Google Scholar), including in OB after lung transplantation, by producing excessive amounts of extracellular matrix. Studies have demonstrated that myofibroblasts are likely to be of multiple origins (5Hinz B Phan SH Thannickal VJ Galli A Bochaton-piallat ML Gabbiani G The myofibroblast One function, multiple origins..Am J Pathol. 2007; 170: 1807-1816Abstract Full Text Full Text PDF PubMed Scopus (1646) Google Scholar) and that one important source is circulating fibrocytes—blood-borne cells expressing hematopoietic cell markers (e.g. CD34, CD45) as well as markers for fibroblasts such as type | collagen (6Quan TE Cowper S Wu SP Bockensted LK Bucala R Circulating fibrocytes: Collagen-secreting cells of the peripheral blood..Int J Biochem Cell Biol. 2004; 36: 598-606Crossref PubMed Scopus (492) Google Scholar). After tissue injury, circulating fibrocytes migrate into the injured tissue in a chemokine-dependent process and differentiate into a myofibroblast phenotype, contributing to wound healing (7Abe R Donnelly SC Peng T Bucala R Metz CN Peripheral blood fibrocytes: Differentiation pathway and migration to wound sites..J Immunol. 2001; 166: 7556-7562Crossref PubMed Scopus (936) Google Scholar). Fibrocyte-like cells of peripheral blood mononuclear cell (PBMC) origin have been demonstrated in pathological fibrotic processes in animal models of asthma (8Schmidt M Sun G Stacey MA Mori L Mattoli S Identification of circulating fibrocytes as precursors of bronchial myofibroblasts in asthma..J Immunol. 2003; 171: 380-389Crossref PubMed Scopus (568) Google Scholar) and pulmonary fibrosis (9Phillips RJ Burdick MD Hong K et al.Circulating fibrocytes traffic to the lungs in response to CxCL12 and mediate fibrosis..J Clin Invest. 2004; 114: 438-446Crossref PubMed Scopus (931) Google Scholar). Furthermore, it has recently been demonstrated that up to 30% of myofibroblasts in OB lesions in human pulmonary allografts are of recipient origin (10Brocker V Langer F Fellous TG et al.Fibroblasts of recipient origin contribute to bronchiolitis obliterans in human lung transplants..Am J Respir Crit Care. 2006; 173: 1276-1282Crossref PubMed Scopus (69) Google Scholar). Matrix metalloproteinases (MMPs) are a group of enzymes that exert various biological effects in cell migration, matrix degradation, as well as inflammatory and immune responses (11Sternlicht MD Werb Z How matrix metalloproteinases regulate cell behavior..Annu Rev Cell Dev Biol. 2001; 17: 463-516Crossref PubMed Scopus (3278) Google Scholar). We have recently demonstrated that broadspectrum MMP inhibition can block the fibrotic process without suppressing alloimmune responses in a rat intra- pulmonary tracheal transplant model of OB (12Sato M Liu M Anraku M et al.Allograft airway fibrosis in the pulmonary milieu: A disorder of tissue remodeling..Am J Transplant. 2008; 8: 517-528Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar). However, the mechanism whereby MMP inhibition reduces the number of myofibroblasts and the degree of airway obliteration has not been elucidated. Since circulating fibrocytes have been demonstrated to express higher levels of MMP-9 (13Hartlapp I Abe R Saeed RW et al.Fibrocytes induce an angiogenic phenotype in cultured endothelial cells and promote angiogenesis in vivo..Faseb J. 2001; 15: 2215-2224Crossref PubMed Scopus (243) Google Scholar), it is possible that circulating fibrocytes contribute to allograft airway fibrosis of OB through MMP-mediated migration into allograft airways. The purpose of the study is to examine the role of MMPs in myofibroblast-mediated fibroproliferative tissue remodeling in allograft airway fibrosis. We use broad-spectrum MMP inhibitors in an intrapulmonary tracheal transplant model of OB. Furthermore, utilizing a novel animal model that combines orthotopic lung transplantation and intrapulmonary tracheal transplantation and culture of PBMC-derived fibroblast-like cells, we elucidate the origin of the myofibroblasts and their MMP-dependent migration into allograft airways. We herein demonstrate that MMP-dependent migration of myofibroblast precursors is an important mechanism of fibroproliferative tissue remodeling that is unlikely to be fully regulated by immunosuppression alone. Male Brown–Norway (BN, MHC class |: RT1An) and Lewis rats (RT1A|) were purchased from Charles River (Wilmington, MA) and maleWistar-Furth rats (WF, RT1Au) were purchased from Harlan Sprague Dawley (Indianapolis, IN). F1 rats were bred from male BN and female Lewis rats in the Toronto General Research Institute. Allogenic (BN to Lewis) intrapulmonary tracheal transplantation was performed as previously described (14Dutly AE Andrade CF Verkaik R et al.A novel model for post-transplant obliterative airway disease reveals angiogenesis from the pulmonary circulation..Am J Transplant. 2005; 5: 248-254Crossref PubMed Scopus (34) Google Scholar). When combined with orthotopic lung transplantation, the left lung of a Lewis rat was transplanted into a male F1 rat as described previously (15Hirayama S Shiraishi T Shirakusa T Higuchi T Miller EJ Prevention of neutrophil migration ameliorates rat lung allograft rejection..Mol Med. 2006; 12: 208-213Crossref PubMed Scopus (24) Google Scholar), and then, after reperfusion, intrapulmonary transplantation of a trachea of WF rat in the Lewis-derived left lung was conducted (n = 4). All animals received care in compliance with the Guide to the Care and Use of Experimental Animals formulated by the Canadian Council on Animal Care. The experimental protocol was approved by the Animal Care Committee of the Toronto General Research Institute. SC080 (gift from Dr. Teresa Sunyer, Pfizer Inc., St. Louis, MO) and MMI270 (gift from Novartis Pharmaceuticals Canada Inc., Canada) are broad-spectrum MMP inhibitors with similar spectra as follows: SC080 (Ki [nM]): MMP-2, 0.01; MMP-3, 0.4; MMP-8, 0.1; MMPP-9, 0.002; MMP-13, 0.02. MMI270 (IC50 [nM]): MMP-2, 10; MMP-3, 16; MMP-8, 8; MMP-12, 12; MMP-13, 6. Allograft recipient animals were treated with: (1Yousem SA Berry GJ Cagle PT et al.Revision of the 1990 working formulation for the classification of pulmonary allograft rejection: Lung Rejection Study Group..J Heart Lung Transplant. 1996; 15: 1-15PubMed Google Scholar) a broadspectrum MMP inhibitor, SC080, 10 mg/kg/day, oral administration, bid, dissolved in a vehicle containing Tween-80 as described previously (12Sato M Liu M Anraku M et al.Allograft airway fibrosis in the pulmonary milieu: A disorder of tissue remodeling..Am J Transplant. 2008; 8: 517-528Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar); (2Trulock EP Christie JD Edwards LB et al.Registry of the International Society for Heart and Lung Transplantation: Twenty-fourth Official Adult Lung and Heart-Lung Transplantation Report-2007..J Heart Lung Transplant. 2007; 26: 782-795Abstract Full Text Full Text PDF PubMed Scopus (446) Google Scholar) a broad-spectrum MMP inhibitor, MMI270, 30 mg/kg/day, oral administration, bid, dissolved in distilled water; (3Boehler A Estenne M Post-transplant bronchiolitis obliterans..Eur Respir J. 2003; 22: 1007-1018Crossref PubMed Scopus (177) Google Scholar) cyclosporine (Novartis Pharmaceuticals Canada Inc.), 10 mg/kg/day, subcutaneous injection, qd and (4Tomasek JJ Gabbiani G Hinz B Chaponnier C Brown RA Myofibroblasts and mechano-regulation of connective tissue remodelling..Nat Rev Mol Cell Biol. 2002; 3: 349-363Crossref PubMed Scopus (3228) Google Scholar) vehicle for SC080 as a control (oral administration), qd. MMP inhibitors were administered via an orogastric tube as described previously (12Sato M Liu M Anraku M et al.Allograft airway fibrosis in the pulmonary milieu: A disorder of tissue remodeling..Am J Transplant. 2008; 8: 517-528Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar). There were six animals in each group. The doses of SC080 and MMI270 were selected to achieve sufficient MMP inhibition in vivo following data provided by Dr. Sunyer and a previous report (16Oganta Y Matono K Nakajima M et al.Efficacy of the MMP inhibitor MMI270 against lung metastasis following removal of orthotopically transplanted human colon cancer in rat..Int J Cancer. 2006; 118: 215-221Crossref PubMed Scopus (18) Google Scholar), respectively. We used formalin-fixed paraffin-embedded sections (5 μm thickness) for H&E staining. To detect the origin of myofibroblasts and proliferation of (myo)fibroblasts, 5 μm-thick frozen and paraffin-embedded sections were used, respectively. After incubation with mouse anti-pan rat MHC class I antibody (OX18, Serotec, Raleigh, NC), mouse anti-RT1An MHC class | antibody (OX27, Serotec), or mouse anti-rat Ki-67 (MIB5, DAKO Canada Inc., Mississauga, Canada) overnight at 4°C, primary antibodies were detected with anti-mouse Alexa-Fluor® 488, followed by careful washing and incubation with Cy3-conjugated anti-a-SMA or anti-vimentin (Sigma-Aldrich, St. Louis, MO). In an experiment using PKH26-labeled cells, unfixed frozen sections were directly stained by unconjugated anti-a-SMA antibody (DAKO) followed by labeling with Alexa-Fluor® 488. Images were acquired with a Nikon Eclipse TE200 microscope and localization of MHC class | was also examined by confocal images acquired with an Olympus fluoview 1000 laser scanning confocal microscope (Olympus Canada Inc., Markham, Canada). To detect apoptosis of fibroblasts and myofibroblasts, we used immunofluorescence labeling for terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) in combination with staining for vimentin or aSMA. Paraffin sections were permeabilized using a microwave, in 0.1 M citrate buffer (pH 6.0) for 7 min, followed by incubation for 1 h at 37°C using the insitu cell death detection kit fluorescein (Roche Applied Science, Indianapolis, IN) and immunofluorescence staining using Cy3-conjugated anti-vimentin or anti-α-SMA antibodies. For immunofluorescence labeling of cultured PBMC-derived cells, the cells were fixed with 4% paraformaldehyde for 60 min, permeabilized with 0.1% Triton-X, blocked with 6% goat serum in PBS and then incubated with primary antibodies of anti-collagen I (Abcam, Cambridge, MA), α-SMA (Sigma) and secondary antibody in the same manner as slide labeling. Cells were washed three times with PBS between steps. Hoechst 33342 (1:1000, Invitrogen Canada Inc., Burlington, Canada) was used for nuclear counter staining in all the immunofluorescence labeling studies. Morphometric quantification of lumenal obliteration after intrapulmonary tracheal transplantation using H&E staining as well as semiquantification of cell numbers using immunofluorescence labeling were conducted in a blinded manner as described previously (12Sato M Liu M Anraku M et al.Allograft airway fibrosis in the pulmonary milieu: A disorder of tissue remodeling..Am J Transplant. 2008; 8: 517-528Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar). PBMCs from normal rat blood underwent centrifugation over Lympholyte® (Cedarlane Laboratories, Burlington, Canada) and 2.5 × 106 cells were plated on a 24-well BD Biocoat™ fibronectin-coated cell culture plate (BD Biosciences, Mississauga, Canada) and cultured in Dulbecco’s modified Eagle’s medium (Invitrogen), supplemented with 20% fetal bovine serum, L-glutamine, penicillin and streptomycin (Sigma). Nonattached cells were removed at day 2 and continuously cultured until day 10. Cells were stained using anti-collagen I (Abcam) to confirm the phenotype. Migration of PBMC-derived fibroblast-like cells was examined via a standard wound healing assay by scraping a monolayer of fibrocytes cultured on fibronectin for 10 days using a pipet tip. To reduce the influence of cell proliferation, fibrocytes were pretreated with mitomycin C (10 μg/mL) for 30 min, followed by a scratch with or without additional treatment with an MMP inhibitor, SC080 or MMI270 (10 nM and 100 nM). After 24 h, images were acquired with a Nikon Eclipse TE200 microscope from the same spots of culture wells and the distance of cell migration was measured with Image J, 1.30v (Wayne Rasbamd, NIH). RNA was extracted from cultured PBMCs or PBMC-derived fibroblast-like cells using the RNeasy plus mini kit (QIAGEN, Mississauga, Canada) following the manufacturer’s instructions. Real-time RT-PCR was conducted as described previously (12Sato M Liu M Anraku M et al.Allograft airway fibrosis in the pulmonary milieu: A disorder of tissue remodeling..Am J Transplant. 2008; 8: 517-528Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar). In addition to the previously described primers, the following primers were used. MMP-12: Forward, 5’-AACACATTTCGTCT CTCTGCTGAT-3’; Reverse, 5’-TTGTCAAGGATGGGTTTTTCACT-3’. TIMP-1: Forward, 5’-CCACCTTATACCAGCGTTATGAGA-3’; Reverse, 5’-CCGGAAACCTGTGGCATTT-3’. CD45: Forward, 5’-CCCGGGATGAGACAGTTGAT-3’; Reverse, 5’-TGCACACTTGTTCCTGTTTCCT-3’. After isolating PBMCs from normal Lewis rats as described above and incubating overnight in a 6-well plate (1 × 107cells/well), cells that were not adhered to culture wells were gently removed. The remaining cells were lifted by Trypsin/EDTA that yielded about 1% of cells. These cells were labeled with PKH26 (Sigma) following the manufacturer’s instructions. After the staining procedure, more than 95% of the cells were viable as demonstrated by trypan blue staining. These PKH26-stained cells (3 × 105 cells/animal/time point) were administered to Lewis rats that had received intrapulmonary transplantation of a BN trachea at postoperative day 7, 10 and 13 (n = 3). The multiple time points were selected based on our experience on this animal model. Initiation of the fibrotic process after in- trapulmonary allograft tracheal transplantation is variable among individual animals ranging from day 9 to day 14 (i.e. some animals show fibrosis as early as day 9 while others show very small amount of fibrosis as late as day 14). To cover the range, we selected these three time points. Labeled cells that were not injected into animals were continuously cultured for 14 days as a control of cell differentiation in vitro. The recipient animals were sacrificed at day 28. Data are expressed as means ± standard error of the mean. In the comparisons among multiple groups, a one-way analysis of variance test was followed by a posthoc Tukey test. All statistical analyses were performed using JMP 5.0 (SAS Institute Inc., Cary, NC). p < 0.05 was reported as significant. The purpose of the study is to examine the role of MMPs in myofibroblast-mediated fibroproliferative tissue remodeling, a potentially important mechanism of OB after lung transplantation. We first examined the possible contribution of MMP-dependent tissue remodeling to the formation of allograft airway fibrosis, using broad-spectrum MMP inhibitors, SC080 or MMI270 in a rat intrapulmonary tracheal transplant model of OB (from BN donor to Lewis recipient). We compared the effects of MMP inhibition with those of a conventional immunosuppressant, cyclosporine. In the first set of animals, drug treatment was initiated from the time of transplantation. At day 28, the lumen of vehicle-treated control allografts was almost completely obliterated by fibrous tissue; the airway epithelium was not observed (Figure 1A-a,e), while cyclosporine treatment prevented obliterative fibrosis and preserved the airway epithelium by day 28 (Figure 1A-b,f). Treatment with SC080 or MMI270 did not protect the airway epithelium at day 28 and the allograft lumen remained partially open (Figure 1A-c,d,g and h). T-cell infiltration was minimal in allografts treated with cyclosporine, while treatment groups of SC080 and MMI270 showed similar numbers of infiltrating T cells to that of control in the lumen at day 28 (Figure 1A-i–|). The result demonstrates that MMP inhibition reduces allograft airway fibrosis without preserving the epithelium or reducing T-cell infiltration, while immunosuppression reduces T-cell infiltration and protects the epithelium, suggesting different mechanisms in reducing fibrosis. Immunosuppression is usually ineffective once the fibrotic process is initiated (17Hele DJ Yacoub MH Belvisi MG The heterotopic tracheal allograft as an animal model of obliterative bronchiolitis..Respir Res. 2001; 2: 169-183Crossref PubMed Scopus (54) Google Scholar). To examine whether MMP inhibition can still reduce fibrosis at such a developing stage of fibrosis, we started MMP inhibition or immunosuppression from day 14, when partial airway fibrosis had already formed in allografts in the present model without any additional treatment (12Sato M Liu M Anraku M et al.Allograft airway fibrosis in the pulmonary milieu: A disorder of tissue remodeling..Am J Transplant. 2008; 8: 517-528Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar). As expected, cyclosporine had no effect on allograft airway obliteration (Figure 1B-b,f), although cyclosporine was still effective to reduce the number of infiltrating T cells in allografts (Figure 1B-j). On the other hand, MMP inhibitors still reduced lumenal obliteration by day 28 (Figure 1B-c,d,g and h). The difference between MMP inhibition and immunosuppression in developing fibrosis further suggests different effects of these medications on allograft airway fibrosis. To support these observations, morphometric quantification of the lumenal obliteration demonstrated significant attenuation of obliterative fibrosis with early and late MMP-inhibitor treatment as well as early cyclosporine treatment (Figure 1C, p = 0.001). Semiquantification of T-cell infiltration in allografts demonstrated the most significant effect with cyclosporine (Figure 1D, p < 0.01). Taken together, the effects of MMP inhibition on allograft airway fibrosis is different from that of immunosuppression. A possible mechanism is the effect on myofibroblast-mediated tissue remodeling that may involve MMPs. Thus, we next examined the effect of MMP inhibition on fibroblasts and myofibroblasts (activated and differentiated myofibroblasts positive for a-SMA (4Tomasek JJ Gabbiani G Hinz B Chaponnier C Brown RA Myofibroblasts and mechano-regulation of connective tissue remodelling..Nat Rev Mol Cell Biol. 2002; 3: 349-363Crossref PubMed Scopus (3228) Google Scholar)) in allograft airway fibrosis. Immunofluorescence labeling for a-SMA and vi- mentin (a marker for general fibroblasts including myofibroblasts) and quantification of myofibroblasts and total fibroblasts demonstrated reduced numbers of myofibroblasts in MMP-inhibitor groups compared to those of control and cyclosporine groups (Figure 2A,B; p < 0.01). Note that the cell counts were conducted within the obliterated area of the graft lumen, so the total number of myofibroblasts in the graft lumen would be even smaller in MMP inhibitor treatment groups. The reduced number of myofibroblasts may be explained by several mechanisms including: (1Yousem SA Berry GJ Cagle PT et al.Revision of the 1990 working formulation for the classification of pulmonary allograft rejection: Lung Rejection Study Group..J Heart Lung Transplant. 1996; 15: 1-15PubMed Google Scholar) reduced migration of myofibroblasts or their precursors; (2Trulock EP Christie JD Edwards LB et al.Registry of the International Society for Heart and Lung Transplantation: Twenty-fourth Official Adult Lung and Heart-Lung Transplantation Report-2007..J Heart Lung Transplant. 2007; 26: 782-795Abstract Full Text Full Text PDF PubMed Scopus (446) Google Scholar) reduced differentiation of myofibroblast precursors into myofibroblasts; (3Boehler A Estenne M Post-transplant bronchiolitis obliterans..Eur Respir J. 2003; 22: 1007-1018Crossref PubMed Scopus (177) Google Scholar) reduced proliferation of myofibroblasts or their precursors and (4Tomasek JJ Gabbiani G Hinz B Chaponnier C Brown RA Myofibroblasts and mechano-regulation of connective tissue remodelling..Nat Rev Mol Cell Biol. 2002; 3: 349-363Crossref PubMed Scopus (3228) Google Scholar) increased cell death in myofibroblasts or their precursors. First, MMP-inhibitor treatment did not significantly change the ratio of myofibroblasts over total fibroblasts including myofibroblasts (i.e. differentiation ratio, Table 1), suggesting that cell differentiation into myofibroblasts was not a significant mechanism whereby MMP inhibition reduced myofibroblasts (Figure 2). Second, cell proliferation that was examined using Ki-67 did not show significant differences among groups in total vimentin(+) fibroblasts or in α-SMA(+) myofibroblasts (Table 1). Third, cell death assessed by TUNEL staining was not significantly different among groups in total fibroblasts or in myofibroblasts (Table 1). Thus, migration of myofibroblasts or their precursors appears to be the important MMP-dependent mechanism of myofibroblast-mediated fibroproliferative tissue remodeling in allograft airway fibrosis.Table 1MMP inhibition does not change the ratio of myofibroblast differentiation, fibroblast/myofibroblast proliferation or apoptosisTreatment groupTreatment (days)Differentiation ratio (%)Proliferating fibroblast (%)Proliferating myofibroblast (%)Apoptotic fibroblast (%)Apoptotic myofibroblast (%)Vehicle0–2878.74 ± 5.501.14 ± 0.260.34 ± 0.171.14 ± 0.260.14 ± 0.0914–2872.39 ± 4.230.93 ± 0.200.32 ± 0.200.93 ± 0.200.21 ± 0.26Cyclosporine0–28*The cyclosporine (day 0–28) group was excluded from the analysis due to the lack of fibrous tissue in the allograft lumen. N.S. = not significant.*The cyclosporine (day 0–28) group was excluded from the analysis due to the lack of fibrous tissue in the allograft lumen. N.S. = not significant.*The cyclosporine (day 0–28) group was excluded from the analysis due to the lack of fibrous tissue in the allograft lumen. N.S. = not significant.*The cyclosporine (day 0–28) group was excluded from the analysis due to the lack of fibrous tissue in the allograft lumen. N.S. = not significant.*The cyclosporine (day 0–28) group was excluded from the analysis due to the lack of fibrous tissue in the allograft lumen. N.S. = not significant.14–2875.51 ± 6.320.45 ± 0.410.15 ± 0.321.14 ± 0.740.73 ± 0.21SC0800–2878.05 ± 5.531.12 ± 0.530.39 ± 0.231.12 ± 0.530.70 ± 0.3014–2863.49 ± 6.091.09 ± 0.470.16 ± 0.091.09 ± 0.470.49 ± 0.19MMI2700–2875.51 ± 5.720.31 ± 0.120.19 ± 0.190.31 ± 0.120.51 ± 0.0814–2871.76 ± 3.210.37 ± 0.230.24 ± 0.170.37 ± 0.230.33 ± 0.19Statistic significanceN.S.N.S.N.S.N.S.N.S.Differentiation ratio is the ratio of α -SMA(+) myofibroblasts among vimentin(+) general fibroblasts including myofibroblasts. Cell proliferation and apoptosis were detected by Ki67 and TUNEL staining, respectively.* The cyclosporine (day 0–28) group was excluded from the analysis due to the lack of fibrous tissue in the allograft lumen. N.S. = not significant. Open table in a new tab Differentiation ratio is the ratio of α -SMA(+) myofibroblasts among vimentin(+) general fibroblasts including myofibroblasts. Cell proliferation and apoptosis were detected by Ki67 and TUNEL staining, respectively. As such, we studied migration of myofibroblasts (or their precursors) in allograft airway fibrosis using a novel experimental system. To examine the origin of myofibroblasts in intrapulmonary allograft airway fibrosis, we used immunofuorescence labeling for an MHC class | molecule, RT1An (OX-27) that is specific for BN or F1 (BN × Lewis) rat. In the group from Lewis (RT1A|)-to-BN, myofibroblasts were intensively stained with RT1An (Figure 3B-a), while RT1An was negative in the BN to Lewis group (Figure 3B-b). These results demonstrate that myofibroblasts in allograft airway fibrosis after intrapulmonary tracheal transplantation exclusively migrate from the recipient animal. Considering the insignificance in the fibroblast-myofibroblast ratio as well as in the proliferation and apoptosis of fibroblasts and myofibroblasts in allograft airway fibrosis (Figure 2and Table 1), migration of myofibroblasts or their precursors are the most likely mechanism that was reduced by MMP inhibition. In the intrapulmonary tracheal transplantation from Wister- Furth (WF, RT1Au) to F1 (BN × Lewis) rats, myofibroblasts were positively labeled for RT1An (Figure 4B-c), once again demonstrating recipient (i.e. F1)-derived myofibroblasts. The staining was not as intensive as that of Lewis-to-BN probably because of the difference in the number of RT1An molecules between BN and F1 rats, the latter of which has only the haploid of BN. To distinguish myofibroblasts of intrapulmonary and ex- trapulmonary origin, we developed a novel animal model by combining orthotopic lung transplantation with intrapulmonary tracheal transplantation. The left lung of a Lewis rat was transplanted into a F1 rat (BN × Lewis) and then a trachea of a WF rat was transplanted into the ortho- topically transplanted Lewis-derived lung (Figure 3A-d). In this novel model, only a tracheal graft derived from a WF rat is expected to be rejected for its mismatched MHC, while the Lewis-derived lung should be accepted by the F1 host. Strikingly, in this model, immunofluorescence labeling for RT1Au positively stained myofibroblasts to a similar degree as those of WF to F1 intrapulmonary allograft tracheal transplantation (Figure 3B-d, c" @default.
• W2037537803 created "2016-06-24" @default.
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• W2037537803 date "2009-05-01" @default.
• W2037537803 modified "2023-09-26" @default.
• W2037537803 title "MMP-Dependent Migration of Extrapulmonary Myofibroblast Progenitors Contributing to Posttransplant Airway Fibrosis in the Lung" @default.
• W2037537803 cites W1505584712 @default.
• W2037537803 cites W1865826530 @default.
• W2037537803 cites W1980788146 @default.
• W2037537803 cites W1981123762 @default.
• W2037537803 cites W1998612840 @default.
• W2037537803 cites W2010841805 @default.
• W2037537803 cites W2011212093 @default.
• W2037537803 cites W2016193552 @default.
• W2037537803 cites W2028085693 @default.
• W2037537803 cites W2030776545 @default.
• W2037537803 cites W2042633155 @default.
• W2037537803 cites W2044837409 @default.
• W2037537803 cites W2059330089 @default.
• W2037537803 cites W2060715078 @default.
• W2037537803 cites W2069580663 @default.
• W2037537803 cites W2079137031 @default.
• W2037537803 cites W2081068301 @default.
• W2037537803 cites W2094548571 @default.
• W2037537803 cites W2108373400 @default.
• W2037537803 cites W2115118727 @default.
• W2037537803 cites W2124203424 @default.
• W2037537803 cites W2127751349 @default.
• W2037537803 cites W2128049766 @default.
• W2037537803 cites W2154239113 @default.
• W2037537803 cites W2168760383 @default.
• W2037537803 cites W2414386938 @default.
• W2037537803 cites W2766892013 @default.
• W2037537803 cites W4248565951 @default.
• W2037537803 cites W4252082388 @default.
• W2037537803 doi "https://doi.org/10.1111/j.1600-6143.2009.02605.x" @default.
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