Hepatic arterial infusion of autologous CD34+ cells for hepatitis C virus-related decompensated cirrhosis: A multicenter, open-label, exploratory randomized controlled trial.

Introduction: In this multicenter clinical study, we aimed to investigate the efficacy and safety of the transhepatic arterial administration of granulocyte-colony stimulating factor (G-CSF)-mobilized autologous peripheral blood (PB)-CD34+ cells compared with standard therapy in patients with decompensated cirrhosis type C. Methods: Patients were randomly assigned (2:1) to the CD34+ cell transplant (CD34+ cell) or standard-of-care (SOC) group and followed up for 52 weeks. The primary endpoints were the non-progression rate of Child-Pugh (CP) scores at 24 weeks post-enrollment and the safety of the protocol treatment. Results: Fourteen patients (CD34+ cell group: 10; SOC group: 4) were enrolled. CP scores at 24 weeks had a non-progression rate of 90% in the CD34+ cell group and 100% in the SOC group, with no significant difference between groups. Importantly, 4 out of 10 patients in the CD34+ cell group exhibited an improvement from decompensated to compensated cirrhosis, whereas all patients in the SOC group remained in decompensated cirrhosis. With regard to secondary endpoints, a trend toward increased serum albumin levels in the CD34+ cell group was noted. Serious adverse events (SAEs) occurred in three patients in the CD34+ cell group and in one patient in the SOC group. No causal relationship was observed between all SAEs and G-CSF, leukapheresis, or cell transplantation in the CD34+ cell group. No patients died and no hepatocellular carcinoma occurred within the study period. Conclusions: PB-CD34+ cell infusion therapy may have the potential to circumvent the decompensated stage of cirrhosis, thus avoiding the need for liver transplantation.

Feasibility of six cycles of lenalidomide-based triplet induction before stem cell collection for newly diagnosed transplant-eligible multiple myeloma.

OBJECTIVES: Achieving a deep response with induction therapy has a major impact on outcomes following autologous stem cell transplantation. Although longer and intensified induction therapy may provide better disease control, longer exposure to lenalidomide negatively affects stem cell yield. We examined the feasibility of 6 cycles of lenalidomide-based triplet induction therapy before stem cell collection in transplant-eligible multiple myeloma patients. METHODS: In this prospective study, patients received a combination of bortezomib, lenalidomide, and dexamethasone for 6 cycles. For patients who did not achieve a deep response after 3 cycles, bortezomib was substituted with carfilzomib for the last 2 cycles (5th and 6th courses). RESULTS: Although only half of the patients achieved a deep response after 3 cycles, all but 1 patient achieved a very good partial response (n = 4) or complete response (n = 5) after completing 6 cycles. Among 9 patients who received cyclophosphamide-based stem cell mobilization, 1 patient required a second mobilization that was successfully performed using plerixafor. After autologous transplantation, 7 patients showed complete response, including 5 with minimal residual disease-negative status. CONCLUSION: This study demonstrates that 6 cycles of lenalidomide-based induction therapy before stem cell collection are a feasible and promising approach for transplant-eligible newly diagnosed multiple myeloma patients.The study is registered at UMIN Clinical Trials Registry as UMIN000026936.Trial registration: UMIN Japan identifier: UMIN000026936.

Relationship Between Corticosteroid Dose and Muscle Oxygen Consumption in Recipients of Hematopoietic Stem-Cell Transplantation.

INTRODUCTION: After hematopoietic stem-cell transplantation (HSCT), patients exhibit decreased muscle strength and muscle oxygen consumption. Furthermore, total corticosteroid dose affects the reduction in muscle strength after HSCT. However, to date, no studies have investigated the relationship between corticosteroid dose and muscle oxygen consumption and saturation in these patients. The purpose of this study was to investigate the relationship between steroid dose and deoxyhemoglobin (ΔHHb) and muscle oxyhemoglobin saturation (ΔSmO2) in patients undergoing HSCT. METHODS: This study included 17 men with hematologic disease who underwent allogeneic HSCT. We evaluated ankle dorsiflexor muscle force, ΔHHb, and ΔSmO2 in skeletal muscles by near-infrared spectroscopy (NIRS) in patients before and after HSCT. RESULTS: Peak ankle dorsiflexion, ΔHHb, and ΔSmO2 decreased significantly after transplantation as compared to measurements taken before transplantation (p < 0.01). The change in peak ankle dorsiflexion from before to after HSCT was not significantly correlated with total steroid dose. However, ΔHHb and ΔSmO2 from before to after HSCT were significantly correlated with total steroid dose (p < 0.01). CONCLUSION: This study showed that higher corticosteroid doses are associated with diminished skeletal muscle O2 consumption and skeletal muscle O2 demand relative to supply. Therefore, rehabilitation staff, nurses, and physicians should take note of these findings in patients undergoing HSCT. Moreover, physiotherapists should be carefully measuring muscle oxidative metabolism on skeletal muscle when planning physical exercise in such patients.

Relationship Between Muscle Oxygen Saturation and Exercise Load in Patients with Malignant Hematopoietic Disease.

Our previous research confirmed that patients with malignant hematopoietic disease already had a low hemoglobin level before allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, no study has determined whether a correlation exists between exercise load, hemoglobin level, and muscle oxygen saturation (SmO2), during exercise. Therefore, the purpose of this study was to investigate whether near-infrared spectroscopy (NIRS)-derived SmO2 is associated with exercise load, as determined by a dynamometer, before allo-HSCT. This study included 19 male patients who received allo-HSCT in Hyogo College of Medicine Hospital (Japan) between November 2009 and October 2012. Patients performed isometric repeated dorsiflexion at 50% maximum voluntary contraction for 180 s to determine exercise load, and SmO2 was evaluated during exercise at the same time using NIRS (BOM-L1TRW, Omega Wave, Inc., Japan). The hemoglobin level was also evaluated before allo-HSCT. Patients with hematopoietic disease before allo-HSCT already had a low hemoglobin level. There was a significant correlation between exercise load and ∆SmO2; however, the hemoglobin level was not correlated with exercise load. In these patients, exercise load might be affected by muscle oxygen consumption rather than by the hemoglobin level. This finding shows that NIRS can used to assess fatigue in patients with malignant hematopoietic disease.

Relationship Between Exercise Capacity and Muscle O2Hb Saturation in Patients Before Hematopoietic Stem-Cell Transplantation.

Patients with hematological malignancy might already have decreased muscle oxygen saturation at rest and exercise capacity before undergoing hematopoietic stem cell transplantation (HSCT). However, to date, no studies have investigated the relationship between exercise capacity and muscle oxygen saturation at rest in these patients. Therefore, purpose of this study was to investigate the relationship between exercise capacity and muscle oxygen-hemoglobin (O2Hb) saturation (SmO2) at rest and patients' hemoglobin level before undergoing HSCT. METHODS: This study included 60 men with hematologic disease who underwent allo-HSCT. Patients performed a 6-minute walk test (6MWT) to determine exercise capacity, and muscle O2Hb saturation at rest was evaluatabed using near-infrared spectroscopy (BOM-L1TRW, Omegawave Inc., Japan); hemoglobin levels in hematological malignancy patients before undergoing HSCT were also evaluated. RESULTS: There was a significant correlation between the 6MWT and muscle O2Hb saturation at rest in hematological malignancy patients (p < 0.05). Additionally, the 6MWT was significantly correlated to the hemoglobin level (p < 0.05). Furthermore, muscle O2Hb saturation at rest was significantly related to hemoglobin level (p < 0.05). CONCLUSION: In patients with hematological malignancy, a relationship exists between exercise capacity, muscle O2Hb saturation, and hemoglobin level before they undergo HSCT. Therefore, rehabilitation staff, nurses, and physicians should recognize these relationships in patients who undergo allo-HSCT. Moreover, physiotherapists may need to promote muscle oxidative metabolism through exercise to increase exercise capacity in these patients.

Predictive value of interim FDG-PET/CT findings in patients with diffuse large B-cell lymphoma treated with R-CHOP.

Objectives: To examine the prognostic value of interim 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) findings after 2-4 cycles of rituximab, plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) in patients with diffuse large B-cell lymphoma (DLBCL) receiving standardized treatment. Results: After a median 3.36 years (range 0.33 to 9.14 years), 24 of the 80 patients had documented relapse. In Interim-PET findings, 2-year PFS was significantly shorter for PET-positive as compared with PET-negative patients (50.0% vs. 86.4%; p = 0.0012). In End-PET findings, 2-year PFS was significantly shorter for PET-positive as compared with PET-negative patients (25.0% vs. 84.7%; p < 0.0001). The positive predictive value (PPV) and negative predictive value (NPV) of Interim-PET for predicting relapse or disease progression were 57.1% and 75.8%, respectively, while those for End-PET were 75.0% and 75.0%, respectively. Methods: Eighty DLBCL patients treated with first-line 6-8 R-CHOP courses regardless of interim imaging findings were enrolled. Each underwent FDG-PET/CT scanning at staging, and again during (Interim-PET) and at the end of (End-PET) therapy. PET positivity or negativity at Interim-PET and End-PET as related to progression-free survival (PFS) was examined using Kaplan-Meier analysis. Conclusion: Mid-treatment FDG-PET/CT findings may be useful for determining disease status in patients with DLBCL undergoing induction R-CHOP chemotherapy, though are not recommended for treatment decisions as part of routine clinical practice.

Safety and efficacy of amnion-derived mesenchymal stem cells (AM01) in patients with steroid-refractory acute graft-versus-host disease after allogeneic haematopoietic stem cell transplantation: a study protocol for a phase I/II Japanese trial.

INTRODUCTION: Regenerative medicine and cell therapies have been gaining much attention among clinicians. Therapeutic infusion of mesenchymal stromal cells (MSCs) is now a leading investigational strategy for the treatment of acute graft-versus-host disease (aGVHD). Bone marrow MSCs are approved for manufacture and marketing as a cell therapy for aGVHD. Our non-clinical studies confirmed that human amnion-derived MSCs had immunomodulatory activity equal to or higher than that of human bone marrow MSCs. This study will aim to evaluate the safety and efficacy of amnion-derived MSCs (AM01) in patients with steroid-refractory aGVHD. METHODS AND ANALYSIS: This study will be a multicentre, single-arm, open-label trial (an interventional study). This clinical trial will begin with a low-dose group, and when safety has been confirmed in at least three cases in the low-dose group, treatment will begin for the high-dose group, for which the safety will also be verified. The primary endpoint is to assess the safety of intravenous infusion therapy of AM01 within 24 hours after intravenous infusion of AM01. The secondary endpoint is to explore the efficacy of intravenous infusion therapy with AM01. ETHICS AND DISSEMINATION: The institutional review boards of all participating hospitals approved this study protocol (latest V3.3.0, 3 August 2018). Final data will be publicly announced. A report releasing the study results will be submitted for publication to an appropriate peer-reviewed journal. TRIAL REGISTRATION NUMBER: UMIN000029945.

Early evaluation of tumor response to 90Y-ibritumomab radioimmunotherapy in relapsed/refractory B cell non-Hodgkin lymphoma: what is the optimal timing for FDG-PET/CT?

PURPOSE: To determine the earliest optimal timing for assessment of early response following radioimmunotherapy in non-Hodgkin lymphoma patients using FDG-PET/CT. METHODS: FDG-PET/CT was performed prior to treatment (PET1), at 2 (PET2) weeks, and at 6 (PET3) weeks after 90Y-ibritumomab radioimmunotherapy in 55 patients. Response was evaluated based on the Deauville 5-point scale and Lugano criteria as well as semiquantitative analysis and compared with progression-free survival (PFS). RESULTS: PET 2 showed complete metabolic response (CMR), partial metabolic response (PMR), stable metabolic disease (SMD), and progressive metabolic disease (PMD) in 33, 13, 6, and 3 patients, respectively, while PET 3 in 41, 8, 3, and 3 patients, respectively. Mean SUVmax of 168 target lesions decreased over time (PET1, 2, 3; 5.58 ± 2.58, 1.87 ± 1.78, 1.75 ± 2.25, respectively). Progression or recurrence after a median of 12.6 months (range 2.6-72.0 months) was seen in 44 patients. Patients with CMR or metabolic response (CMR + PMR) on PET2 showed significantly longer PFS as compared to those who did not (p = 0.00028 and p = 0.029, respectively). A similar significant difference was observed based on PET3 (p = 0.00013 and p = 0.017, respectively). The same trend was observed when analyzing only the subgroup of patients with follicular lymphoma (N = 43/55) (p < 0.0001). CONCLUSION: Use of FDG-PET/CT findings with Lugano criteria for assessing early response to radioimmunotherapy after 6 weeks allowed for accurate evaluation and prognostic stratification, though scanning after 2 weeks was too soon to precisely evaluate response. KEY POINTS: • The optimal timing of FDG-PET/CT to obtain a suitable tool for assessment of response after 90 Y-ibritumomab radioimmunotherapy of lymphoma has not yet been defined. • Assessment after 6 weeks by FDG-PET/CT using the Lugano criteria accurately evaluates treatment response and prognosis. • FDG-PET/CT performed 2 weeks after radioimmunotherapy is too early as it significantly misses objective responses.

Aldehyde dehydrogenase activity in cryopreserved cord blood cells for quality assessment prior to transplantation.

In umbilical cord blood transplantation (UCBT), the number of cluster of differentiation (CD)34+ cells and colony­forming units (CFUs) in the cord blood (CB) graft positively correlate with patient survival. Therefore, these parameters are currently used for quality assessment of the cryopreserved CB cells in the attached segment that is considered representative of the CB in the main bag prior to UCBT. Since aldehyde dehydrogenase (ALDH) activity is high in hematopoietic stem cells, the number of ALDH­bright (ALDHbr) cells was examined in comparison with the number of CD34+ cells and CFUs for the quality assessment of CB units. In the cryopreserved main bag, the number of ALDHbr cells in the CB unit exhibited positive correlation with the number of CD34+ cells, and with CFU­granulocytes/macrophages and total CFU counts. Furthermore, the concentration of ALDHbr cells in the cryopreserved attached segment was not significantly different compared to that of the main bag, suggesting that the attached segment is representative of the main bag. In conclusion, the present study suggested that ALDHbr cell counts in the cryopreserved attached segments may serve as a quality assessment indicator for CB units prior to UCBT.

Prospective randomized and crossover comparison of two apheresis machines for peripheral blood stem cell collection: a multicenter study.

BACKGROUND: Improving apheresis technology may lead to an efficient and safe peripheral blood stem cell (PBSC) collection. Recently, the Spectra Optia (Optia, Terumo BCT) was introduced as an automated apheresis instrument, but comparisons with other instruments have been few. This is the first randomized multicenter and crossover comparison of the Optia with the automated program of the established apheresis instrument, the Spectra (Spectra-Auto, Terumo BCT). STUDY DESIGN AND METHODS: A total of 233 apheresis procedures performed in 46 autologous patients and 108 allogeneic donors were investigated. Apheresis performed in the first day for all subjects using the Spectra-Auto (n = 79) and the Optia (n = 75) were evaluated as first-day analysis. Seventy-nine subjects, who required another session on the second day, underwent apheresis using the other instrument than the first-day instrument and were compared with each other in a paired crossover analysis. RESULTS: The two instruments processed similar volumes with comparable run times and volumes of acid-citrate-dextrose used. The volumes of collected products were greater in the Optia. Yields of mononuclear cells and CD34+ cells were not different, but collection efficiencies were higher in the Optia (p = 0.008 in CE1 of crossover analysis). Spectra-Auto-collected products contained more contaminating red blood cells (RBCs), whereas there was a trend of more contaminating platelets (PLTs) in the Optia-collected products. Slight reductions were noted in the RBC or PLT counts of subjects who underwent apheresis with the Spectra-Auto or the Optia, respectively. CONCLUSION: The Optia is safe and more efficient in the PBSC collection compared with the Spectra-Auto.

Host Foxp3+CD4+ Regulatory T Cells Act as a Negative Regulator of Dendritic Cells in the Peritransplantation Period.

Host Foxp3+CD4+ regulatory T cells (Tregs) have been shown to suppress graft-versus-host disease (GVHD) in experimental bone marrow transplantation (BMT) models; however, the detailed mechanism is unknown. To address this issue, we established a murine MHC-haploidentical BMT model (BDF1 (H-2b/d) → B6C3F1 (H-2b/k)), in which transplantation following conditioning with high-dose (13 Gy) or low-dose (5 Gy) total body irradiation corresponds to myeloablative stem cell transplantation (MAST) or reduced-intensity stem cell transplantation (RIST) BMT. All MAST recipients died of GVHD within 70 d, whereas RIST recipients developed almost no GVHD and survived for at least 3 mo. In this BMT model, we investigated the kinetics of immune cells in the mesenteric lymph nodes because GVHD was most prominent in the intestines. Host Tregs that survived after total body irradiation could proliferate transiently by day 4. Comparing the kinetics of immune cells among MAST, RIST, and anti-CD25 mAb-treated RIST, we found that the transiently surviving host Tregs were fully functional, closely contacted with host dendritic cells (DCs), and significantly restrained the maturation (CD80 and CD86 expression) of DCs in a dose-dependent manner. There was a positive correlation between the ratio of DCs to host Tregs and the extent of maturation of DCs. Host Tregs suppressed alloresponse mainly by contact inhibition. Host Tregs are already active in lymph nodes before transplantation and restrain the maturation of host DCs, thereby dampening the ability of DCs to activate allogeneic donor T cells and consequently reducing the magnitude of graft-versus-host reaction. Thus, host Tregs are negative regulators of host DCs that act in the peritransplantation period.

Inhibition of Src family kinases overcomes anoikis resistance induced by spheroid formation and facilitates cisplatin-induced apoptosis in human mesothelioma cells.

Malignant mesothelioma is an aggressive tumor arising from mesothelial cells of serous membranes, and forms spheroid-like cell aggregates in pleural and peritoneal effusions. We examined the levels of anoikis, apoptosis induced by the detachment of cells from the extracellur matrix, in suspension culture in the human mesothelioma cell line NCI-H2052. NCI-H2052 cells were adherent in conventional monolayer cultures, but were found to form spheroids in suspension cultures using dishes with ultra-low cell binding capacity. NCI-H2052 cells proliferated in both cultures, but the proliferation rate was markedly lower in suspension cultures than in monolayer cultures. In addition, NCI-H2052 cells in suspension cultures showed little apoptosis, suggesting that the suspension culture induces anoikis resistance. Western blot analysis revealed that suspension cultures induced activation of Src family kinases (SFK) after spheroid formation. Dasatinib, an inhibitor of multi-tyrosine kinases including SFK, abolished anoikis resistance in suspension cultures, indicating that SFK activated by spheroid formation are responsible for anoikis resistance. Cisplatin induced apoptosis in NCI-H2052 cells, but the apoptotic rate was significantly lower in suspension cultures than in monolayer cultures, suggesting that spheroid formation is involved in cisplatin resistance. Furthermore, a combination of dasatinib and cisplatin induced apoptosis more significantly than either alone in suspension cultures. These results suggest that spheroid formation induces resistance to anoikis and to cisplatin through SFK activation and that dasatinib facilitates cisplatin-induced apoptosis in human mesothelioma cells.

Suppression of heme oxygenase-1 activity reduces airway hyperresponsiveness and inflammation in a mouse model of asthma.

OBJECTIVE: Carbon monoxide (CO) levels in expired gas are higher in patients with bronchial asthma than in healthy individuals. Heme oxygenase-1 (HO-1) is a rate-limiting enzyme that catalyzes the degradation of heme to yield biliverdin, CO and free iron. Thus, HO-1 is implicated in the pathogenesis of bronchial asthma. However, whether HO-1 expression and activity in lung tissue are related to allergic airway inflammation remains unclear. We investigated whether expression of HO-1 is related to allergic airway inflammation in lungs and whether HO-1 could influence airway hyperresponsiveness and eosinophilia in mice sensitized to ovalbumin (OVA). METHODS: C57BL/6 mice immunized with OVA were challenged thrice with an aerosol of OVA every second day for 8 days. HO-1-positive cells were identified by immunostaining in lung tissue, and zinc protoporphyrin (Zn-PP), a competitive inhibitor of HO-1, was administered intraperitoneally to OVA-immunized C57BL/6 mice on day 23 (day before inhalation of OVA) and immediately before inhalation on the subsequent 4 days (total five doses). Mice were analyzed for effects of HO-1 on AHR, inflammatory cell infiltration and cytokine levels in lung tissue. Ethical approval was obtained from the concerned institutional review board. RESULTS: Number of HO-1-positive cells increased in the subepithelium of the bronchi after OVA challenge, and HO-1 localized to alveolar macrophages. Zn-PP clearly inhibited AHR, pulmonary eosinophilia and IL-5 and IL-13 expression in the lung tissue. CONCLUSION: Expression of HO-1 is induced in lung tissue during attacks of allergic bronchial asthma, and its activity likely amplifies and prolongs allergic airway inflammation.

Primary extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue type with malakoplakia in the urinary bladder: a case report.

Primary malignant lymphoma of the urinary bladder is a rare disease constituting less than 1% of neoplasms of the urinary bladder. The most prevalent histological subtype is extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue type (MALT lymphoma). It is frequently associated with chronic cystitis and predominantly occurs in females. On the other hand, malakoplakia is thought to be a reactive granulomatous lesion occurring most prevalently in the genitourinary tracts. It is frequently found in females and often associated with bacterial infection in immunosuppressive status. Here we report a rare case of concurrent primary MALT lymphoma and malakoplakia in the urinary bladder in a 78-year-old Japanese female. Presumably, both lymphoma and malakoplakia are considered to be involved in the antecedent cystitis and might contribute to the development of the urinary bladder tumor of the patient, leading to the occlusion of the right ureter with subsequent hydronephrosis.

Cell-adhesion molecule expression and the proliferation of malignant mesothelioma: a post-mortem examination.

AIM: In order to determine if metastatic malignant mesothelioma cells are more aggressive than primary malignant mesothelioma cells, an analysis of the expression of the adhesion molecules E-cadherin and ß-catenin, concomitant with an assessment of the proliferative activity at primary and metastatic sites, was conducted in post-mortem samples. MATERIALS AND METHODS: E-cadherin or ß-catenin expression was graded according to the percentage of positively-stained tumor cells. The proliferative activity was quantified by the Ki-67 labeling index. RESULTS: Histologically, the majority of metastatic tumors matched the primary tumor. In the epithelioid component of primary tumors, E-cadherin and ß-catenin expression ranged from 1+ to 4+. CONCLUSION: Malignant mesothelioma cells acquire a higher proliferative potential after metastasis, without any significant changes in their histology, although metastasis produces no definite trend on the expression of E-cadherin or ß-catenin.

Soluble interleukin-2 receptor level on day 7 as a predictor of graft-versus-host disease after HLA-haploidentical stem cell transplantation using reduced-intensity conditioning.

In the present study, we analyzed the kinetics of serum soluble interleukin-2 receptor (sIL-2R) using data from 77 patients undergoing HLA-haploidentical transplantation using reduced-intensity conditioning (RIC), who were at an advanced stage or at high risk for relapse, to clarify the usefulness of sIL-2R as a biomarker of acute graft-versus-host disease (GVHD). Anti-T-lymphocyte globulin and methylprednisolone were used as GVHD prophylaxis. While the median sIL-2R in 38 patients not developing GVHD was suppressed at levels <740 U/ml, sIL-2R in 25 patients developing severe GVHD peaked on day 11 (1,663 U/ml), and thereafter decreased to <1,000 U/ml after day 30. The occurrence of GVHD was not limited to times of high sIL-2R level, but occurred at any time point on the sIL-2R curve. Most patients developing GVHD, however, experienced a higher sIL-2R level early in their transplant course. The combination of RIC and glucocorticoids sufficiently suppressed sIL-2R levels after HLA-haploidentical transplantation. In a multivariate analysis to identify factors associated with GVHD, day 7 sIL-2R >810 U/ml was the only factor significantly associated with the occurrence of severe GVHD (p = 0.0101).

Recombinant human soluble thrombomodulin attenuates FK506-induced endothelial dysfunction through prevention of Akt inactivation.

Thrombomodulin (TM), a transmembrane glycoprotein on vascular endothelial cells, is a naturally occurring anticoagulant. Recombinant human soluble TM (rTM), composed of the extracellular domain of TM, also shows anti-coagulant and anti-inflammatory activity, but the effects of rTM on microangiopathy remain unclear. We reported that FK506 induced endothelial dysfunction through inactivation of Akt and extracellular-regulated kinase 1/2 using a three-dimensional culture blood vessel model. In the present study, we examined the effects of rTM on FK506-induced endothelial dysfunction. We found that rTM suppressed FK506-induced endothelial cell death, but not the breakdown of capillary-like tube structures. rTM prevented FK506-induced inactivation of Akt, but not of extracellular-regulated kinase 1/2. Akt inhibition by LY294002 abrogated the preventive effect of rTM on FK506-induced Akt inactivation and the suppressive effect of rTM on FK506-induced cell death. These results suggest that rTM attenuates FK506-induced endothelial dysfunction through prevention of Akt inactivation.

FK506 induces endothelial dysfunction through attenuation of Akt and ERK1/2 independently of calcineurin inhibition and the caspase pathway.

Calcineurin inhibitors such as cyclosporin A (CsA) and FK506 have been used in solid organ and hematopoietic stem cell transplantations to suppress immune function. However, these immunosuppresants are associated with severe endothelial dysfunction. We investigated whether CsA and FK506 induce endothelial dysfunction using a three-dimensional culture blood vessel model, in which human umbilical vein endothelial cells form and maintain capillary-like tube and lumen structures. We found that FK506, but not CsA, induced breakdown of the tube structures and endothelial cell death. FK506 inhibited calcineurin activity, but FK506-induced tube breakdown and cell death was not suppressed by RNA interference targeting calcineurin Aα. FK506 also induced caspase activation, but caspase inhibition by zVAD(OMe)-fmk failed to suppress FK506-induced tube breakdown and cell death. FK506 induced attenuation of Akt and extracellular-regulated kinase 1/2 (ERK1/2). Furthermore, Akt inhibition by LY294002 or ERK1/2 inhibition by PD98059 induced tube breakdown and cell death. Present results suggest that FK506 induces endothelial dysfunction through attenuation of Akt and ERK1/2 independently of calcineurin inhibition and the caspase pathway.