Quantification of substrate and cellular strains in stretchable 3D cell cultures: an experimental and computational framework.

The mechanical cell environment is a key regulator of biological processes . In living tissues, cells are embedded into the 3D extracellular matrix and permanently exposed to mechanical forces. Quantification of the cellular strain state in a 3D matrix is therefore the first step towards understanding how physical cues determine single cell and multicellular behaviour. The majority of cell assays are, however, based on 2D cell cultures that lack many essential features of the in vivo cellular environment. Furthermore, nondestructive measurement of substrate and cellular mechanics requires appropriate computational tools for microscopic image analysis and interpretation. Here, we present an experimental and computational framework for generation and quantification of the cellular strain state in 3D cell cultures using a combination of 3D substrate stretcher, multichannel microscopic imaging and computational image analysis. The 3D substrate stretcher enables deformation of living cells embedded in bead-labelled 3D collagen hydrogels. Local substrate and cell deformations are determined by tracking displacement of fluorescent beads with subsequent finite element interpolation of cell strains over a tetrahedral tessellation. In this feasibility study, we debate diverse aspects of deformable 3D culture construction, quantification and evaluation, and present an example of its application for quantitative analysis of a cellular model system based on primary mouse hepatocytes undergoing transforming growth factor (TGF-ß) induced epithelial-to-mesenchymal transition.

Iron overload induced by ferric ammonium citrate triggers reactive oxygen species-mediated apoptosis via both extrinsic and intrinsic pathways in human hepatic cells.

BACKGROUND: Hepatic iron overload is common in patients with myelodysplastic syndromes undergoing hematopoietic cell transplantation (HCT) and may predispose to peri- and post-HCT toxicity. To better understand the mechanisms of iron overload-induced liver injury, we examined the effects of iron overload induced by ferric ammonium citrate (FAC) on oxidative stress and apoptosis signaling pathway in human hepatic cell line HH4. METHODS AND RESULTS: Hepatic HH4 cells were exposed to FAC to force iron uptake, and cellular responses were determined. Incubation with 5 mM FAC resulted in increased intracellular iron content in a time-dependent manner. High concentration of FAC impaired cell viability and increased level of reactive oxygen species (ROS), and addition of antioxidant reagent such as glutathione or N-acetylcysteine dramatically reduced FAC-induced intracellular ROS generation. FAC overload significantly increased the phosphorylation of inhibitor of κB-α, p38 mitogen-activated protein kinase (MAPK), and nuclear factor κ light chain enhancer of activated B cells (NF-κB) p65 and promoted the nuclear translocation of NF-κB p65. Knockdown of Fas and Bid expression by small interfering RNA in iron-treated HH4 cells resulted in restoration of cell viability. CONCLUSIONS: We reported that FAC treatment is capable of inducing both extrinsic death receptor and intrinsic mitochondrial signaling pathway-mediated HH4 cells apoptosis through ROS-activated p38 MAPK and NF-κB pathways.

Indication and management of allogeneic stem cell transplantation in primary myelofibrosis: a consensus process by an EBMT/ELN international working group.

The aim of this work is to produce recommendations on the management of allogeneic stem cell transplantation (allo-SCT) in primary myelofibrosis (PMF). A comprehensive systematic review of articles released from 1999 to 2015 (January) was used as a source of scientific evidence. Recommendations were produced using a Delphi process involving a panel of 23 experts appointed by the European LeukemiaNet and European Blood and Marrow Transplantation Group. Key questions included patient selection, donor selection, pre-transplant management, conditioning regimen, post-transplant management, prevention and management of relapse after transplant. Patients with intermediate-2- or high-risk disease and age <70 years should be considered as candidates for allo-SCT. Patients with intermediate-1-risk disease and age <65 years should be considered as candidates if they present with either refractory, transfusion-dependent anemia, or a percentage of blasts in peripheral blood (PB) >2%, or adverse cytogenetics. Pre-transplant splenectomy should be decided on a case by case basis. Patients with intermediate-2- or high-risk disease lacking an human leukocyte antigen (HLA)-matched sibling or unrelated donor, should be enrolled in a protocol using HLA non-identical donors. PB was considered the most appropriate source of hematopoietic stem cells for HLA-matched sibling and unrelated donor transplants. The optimal intensity of the conditioning regimen still needs to be defined. Strategies such as discontinuation of immune-suppressive drugs, donor lymphocyte infusion or both were deemed appropriate to avoid clinical relapse. In conclusion, we provided consensus-based recommendations aimed to optimize allo-SCT in PMF. Unmet clinical needs were highlighted.

Recovery of normal autologous myelopoiesis after graft rejection following allogeneic bone marrow transplant for agnogenic myeloid metaplasia.

Allogeneic hematopoietic transplantation is the only currently available therapy that has the potential to cure agnogenic myeloid metaplasia (AMM) or primary myelofibrosis (PMF). Amelioration of fibrosis and eradication of the abnormal clone is thought to occur through the repopulation of marrow by donor-derived hematopoiesis and graft-vs.-host reaction leading to graft vs. tumor effect. We report here a 50-year-old female with AMM/PMF, conditioned with busulfan and cyclophosphamide, who rejected a single locus (HLA-B) mismatched bone marrow transplant from her daughter, but recovered normal autologous hematopoiesis with disappearance of marrow fibrosis and extramedullary hematopoiesis. Variable number tandem repeats (VNTR) analysis showed a gradual loss of donor-derived hematopoietic cells with recovery of autologous hematopoiesis. This case therefore illustrates that eradication of AMM/PMF in this patient with myeloablative chemotherapy combined with a transient allogeneic effect was sufficient to suppress the abnormal stem cell clone associated with AMM/PMF with subsequent cure.

Changing from cyclosporine to tacrolimus as salvage therapy for chronic graft-versus-host disease.

Chronic graft-versus-host disease (GVHD) is the principal cause of transplantation-related morbidity and nonrelapse mortality late after allogeneic hematopoietic stem cell transplantation. The safety and potential efficacy of tacrolimus for the salvage treatment of chronic GVHD was evaluated in a single-arm, open-label phase 2 study. A total of 39 evaluable patients with chronic GVHD who failed previous immunosuppressive therapy with cyclosporine and prednisone were treated with tacrolimus starting at a median of 20 months (range, 3-68 months) after transplantation. At 3 years after the start of treatment, 5 patients (13%) had discontinued tacrolimus and were in complete remission, and 3 were considered clinically stable but not able to discontinue tacrolimus. A total of 31 patients (79%) experienced treatment failure; 22 (56%) who failed therapy had a change in immunosuppressive regimen because of progression (n = 18) or toxicity (n = 4). Nine patients (23%) died during continued treatment with tacrolimus. Two patients were lost to follow-up, at 11 and 19 months. The median duration of treatment with tacrolimus was 9 months (range, 1-29 months). Infections (144 episodes) were the most frequent adverse event. Nephrotoxicity occurred in 16 patients (41%); tacrolimus was discontinued in only 2 patients because of progressive deterioration in renal function. The Kaplan-Meier estimate of survival was 64% (95% confidence interval, 49%-79%) at 3 years posttransplantation. Seven patients had discontinued all immunosuppression at last contact, leading to an estimated 29% probability of stopping all immunosuppression by 3 years posttransplantation. Four patients died after relapse of malignancy. The response rate is consistent with previous reports of salvage treatment for chronic GVHD, indicating that a small group of patients failing cyclosporine may respond or stabilize with tacrolimus.

Pharmacokinetics of intravenous busulfan and evaluation of the bioavailability of the oral formulation in conditioning for haematopoietic stem cell transplantation.

Busulfan (BU) is included in many conditioning protocols for haematopoietic stem cell transplantation (HSCT). Pharmacokinetic parameters in individual patients have been related to short-term toxicity and risk of relapse after HSCT. In a series of 11 patients receiving the usual 16 x 1 mg/kg schedule over 4 days, we investigated the pharmacokinetics of replacing one dose with an intravenous formulation (BU in DMSO) which we had previously investigated in dogs. A dose of 0.5-0.6 mg/kg was used. No acute side-effects of BU/DMSO infusions administered over 1 h were observed. Bioavailability of BU powder capsules was on average 70% (range, 44-94%). Interindividual variability of the resulting AUC after intravenous doses was still substantial. Further studies are under way to define the possible role of BU/DMSO infusions in conditioning before HSCT.

Effects of granulocyte colony-stimulating factor and stem cell factor, alone and in combination, on the mobilization of peripheral blood cells that engraft lethally irradiated dogs.

The effects of recombinant canine granulocyte colony-stimulating factor (rcG-CSF) and recombinant canine stem cell factor (rcSCF), a c-kit ligand, on the circulation of hematopoietic progenitor and stem cells were studied in a canine model. Administration of rcG-CSF (10 micrograms/kg) for 7 days led to a 5.4-fold increase in CFU-GM/mL of blood, while 7 days of rcSCF (200 micrograms/kg) led to an 8.2-fold increase. Although treatment with low-dose rcSCF (25 micrograms/kg) had no effect on the level of peripheral blood progenitors, 7-day exposure to a combination of G-CSF plus low dose SCF led to a 21.6-fold increase (P = .03). To assess the ability of these factors to increase the circulation of cells capable of rescuing animals after lethal total body irradiation (TBI), 1 x 10(8) peripheral blood mononuclear cells (PBMC)/kg were collected and cryopreserved from animals after 7 days of treatment with G-CSF, SCF or a combination of the two. One month later, animals were exposed to 9.2 Gy TBI and transplanted with the previously collected cells. Control animals transplanted with 1 x 10(8) PBMC/kg collected without pretreatment died with marrow aplasia 11 to 29 days after TBI as did animals treated with only low-dose SCF before cell collection. In contrast, all animals given PBMC collected after G-CSF, high-dose SCF, or a combination of G-CSF plus low-dose SCF recovered granulocyte function. Recovery to 500 granulocytes/microL after transplant took 17, 18.8, and 13.6 days, respectively, (P = .056 for the difference between the combination G-CSF-SCF group and the other two groups). In both the G-CSF and SCF groups, 4 of 5 animals completely recovered while 1 of 5 in each group died with prolonged thrombocytopenia. In the combination group, all 5 animals became long-term survivors. These studies demonstrate that both G-CSF and SCF dramatically increase the level of peripheral blood hematopoietic progenitor and stem cells and support the view that these factors can act synergistically.

Transfer of specific immunity in marrow recipients given HLA-mismatched, T cell-depleted, or HLA-identical marrow grafts.

The transfer of tetanus toxoid (TT) and diphtheria toxoid (DT) specific immunity was evaluated in 209 short-term (less than 120 days postgrafting) and 257 long-term (greater than 198 days postgrafting) non-boosted recipients after HLA-identical, HLA non-identical, and HLA-identical T cell-depleted marrow transplantation. TT or DT immunizations were not given to donors in the 6 months prior to transplant and the recipients received no immunizations post-transplantation. In 209 short-term recipients, 94% and 74% of recipients had detectable anti-TT and anti-DT titers respectively. In long-term recipients, 110 of 210 (52%) who received HLA-identical grafts, 17 of 38 (45%) who received HLA-non-identical grafts, and seven of seven (100%) who received HLA-identical T cell-depleted grafts had anti-TT titers; and 86 of 212 (40%) who received HLA-identical grafts, 11 of 38 (29%) who received HLA-non-identical grafts, and four of seven (57%) who received HLA-identical T cell-depleted grafts had anti-DT titers. When compared to non-boosted normal donor and control subjects, the magnitudes of anti-TT and anti-DT titers from the recipients were comparable to controls. These data show that transferred specific immunity is detectable in long-term recipients of T cell-depleted or HLA-non-identical grafts without immunizations of donors or recipients before or after transplantation.

Lymphocytic bronchitis unrelated to acute graft-versus-host disease in canine marrow graft recipients.

We reviewed coded autopsy material from 71 dogs, 46 receiving allogeneic and 25 receiving autologous bone marrow transplants, to evaluate the hypothesis that lymphocytic bronchitis is associated with severe acute graft-versus-host disease (GVHD). We found no significant correlation between the presence of lymphocytic bronchitis and severe acute GVHD (P greater than 0.16). Using a binary regression model that corrected for possible confounding relationships, we failed to show a correlation between lymphocytic bronchitis and acute GVHD of each of the 3 classically affected organ systems. Also, no correlation was found between lymphocytic bronchitis and acute bacterial pneumonia (P greater than 0.32). Finally, lymphocytic bronchitis was present in autografted dogs with a prevalence at autopsy not significantly different from that of allografted dogs (P greater than 0.32). We conclude that lymphocytic bronchitis in this canine model represents nonspecific inflammation rather than acute pulmonary GVHD.

Marrow transplantation from HLA-identical siblings for treatment of aplastic anemia: is exposure to marrow donor blood products 24 hours before high-dose cyclophosphamide needed for successful engraftment?

The present study in patients with aplastic anemia was undertaken to determine whether exposure of recipients to donor blood products 24 hr before preparation with cyclophosphamide (1) enhanced the rate of sustained engraftment of marrow from HLA-identical siblings as suggested by animal experiments, (2) increased the rejection rate, in particular in transfused patients who may already have been exposed to donor antigens by blood products, or (3) was of no relevance to the outcome of transplantation of marrow from HLA-identical siblings. One-hundred fifty-five patients were studied, of whom 78 received blood products from the marrow donor 24 hr before cyclophosphamide and 77 did not. A binary logistic regression analysis was applied to the data, simultaneously considering five previously known risk factors for rejection. Results showed that preceding transfusion of donor blood products had neither a significant beneficial nor detrimental effect on the incidence of sustained engraftment.

Graft-versus-host disease and survival in patients with aplastic anemia treated by marrow grafts from HLA-identical siblings. Beneficial effect of a protective environment.

One hundred thirty patients with severe aplastic anemia were conditioned with cyclophosphamide for transplantation of marrow from HLA-identical siblings. The patients were selected for the present analysis according to the criterion of sustained marrow engraftment. Of the 130 patients, 97 are now alive between 1.4 and 11 years (median, 5) after transplantation. Twenty-nine of the thirty-three who died had either acute or chronic graft-versus-host disease (GVHD). Our analysis was directed at identifying factors predicting GVHD and survival after transplantation in patients. Our key findings were that moderately severe to severe acute GVHD had a strong adverse influence on survival; that a protective environment significantly reduced mortality, which corresponded in part to a reduction in and delayed onset of acute GVHD; that refractoriness to random-donor platelet infusions at transplantation adversely influenced survival, particularly among patients with acute GVHD; and that increasing age was associated with increased mortality.

Treatment of chronic granulocytic leukaemia in chronic phase by allogeneic marrow transplantation.

Ten patients with chronic granulocytic leukaemia in the chronic phase have been treated with chemoradiotherapy followed by transplantation of bone marrow from HLA-identical siblings. Engraftment was achieved in all patients, and Philadelphia chromosome disappeared from the nine patients who had it before transplantation. Four patients have died, three with interstitial pneumonitis and one with severe graft-versus-host disease (GvHD). Six patients are alive and well in complete clinical, cytogenetic, and haematological remission, 1-3 years after transplantation, despite complications in three patients (one had interstitial pneumonitis, one had mild veno-occlusive disease of the liver, and one had severe GvHD).

Recovery of antibody production in human allogeneic marrow graft recipients: influence of time posttransplantation, the presence or absence of chronic graft-versus-host disease, and antithymocyte globulin treatment.

One-hundred fifty-three recipients of HLA-identical sibling marrow transplants for aplastic anemia or hematologic malignancy were injected with bacteriophage phi X174 (phage), pneumococcal polysaccharide antigen (PPA), or keyhole limpet hemocyanin (KLH). Antibody levels were determined several times in the 6 wk after injection. Multiple regression techniques were used to determine what factors played significant roles in the antibody response. The most significant factors were the time elapsed from transplantation, chronic graft-versus-host disease (GVHD), and antithymocyte globulin (ATG) treatment. All patients had low antibody responses to all antigens in the first 180 days from transplant. Beyond 180 days patients without chronic GVHD showed antibody responses indistinguishable from those of normal donors. However, patients with chronic GVHD had the following impairments: (1) primary response to phage, (2) conversion from IgM to IgG in secondary response to phage, (3) secondary response to KLH, and (4) response to PPA. ATG treatment given to patients either prophylactically or therapeutically for acute GVHD was followed by lower primary responses to phage in the first 180 days and poor ability to switch from IgM to IgG antibody in the secondary response beyond 180 days postgrafting. Other factors did not yield additional significant information about ability to predict antibody responses including diagnosis, conditioning regimen, treatment in or out of laminar air flow rooms, transplantation, pretransplant refractoriness of the recipient to platelet transfusions from random donors, donor age or donor sex, and steroid administration for treatment for prevention of GVHD. The data indicate that, given enough time after transplantation, the ability to produce normal antibody function recovers except in those patients experiencing chronic GVHD.