Murine Cardiac Transplantation Model Research Articles

The CaMK Family Differentially Promotes Necroptosis and Mouse Cardiac Graft Injury and Rejection.

Organ transplantation is associated with various forms of programmed cell death which can accelerate transplant injury and rejection. Targeting cell death in donor organs may represent a novel strategy for preventing allograft injury. We have previously demonstrated that necroptosis plays a key role in promoting transplant injury. Recently, we have found that mitochondria function is linked to necroptosis. However, it remains unknown how necroptosis signaling pathways regulate mitochondrial function during necroptosis. In this study, we investigated the receptor-interacting protein kinase 3 (RIPK3) mediated mitochondrial dysfunction and necroptosis. We demonstrate that the calmodulin-dependent protein kinase (CaMK) family members CaMK1, 2, and 4 form a complex with RIPK3 in mouse cardiac endothelial cells, to promote trans-phosphorylation during necroptosis. CaMK1 and 4 directly activated the dynamin-related protein-1 (Drp1), while CaMK2 indirectly activated Drp1 via the phosphoglycerate mutase 5 (PGAM5). The inhibition of CaMKs restored mitochondrial function and effectively prevented endothelial cell death. CaMKs inhibition inhibited activation of CaMKs and Drp1, and cell death and heart tissue injury (n = 6/group, p < 0.01) in a murine model of cardiac transplantation. Importantly, the inhibition of CaMKs greatly prolonged heart graft survival (n = 8/group, p < 0.01). In conclusion, CaMK family members orchestrate cell death in two different pathways and may be potential therapeutic targets in preventing cell death and transplant injury.

Graft Protective and Intercellular Immunomodulatory Effects by Adoptive Transfer of an Agonistic Anti-BTLA mAb (3C10) Induced CD4+CD25+ Regulatory T Cells in Murine Cardiac Allograft Transplant Model

We demonstrated that an agonistic anti-B and T lymphocyte attenuator antibody (3C10) prolonged cardiac survival by inducing regulatory T cells (Treg). However, the mechanisms of immune tolerance in the recipients remained unclear. In this study, we investigated the graft-protective and intercellular immunomodulatory effects of adoptive transfer (AT) of 3C10-induced Tregs in a murine cardiac allograft transplant model. Thirty days after transplantation of a C57BL/6 heart into the primary 3C10-treated CBA recipients, splenic CD4+CD25+ cells from these recipients (3C10/AT group) or naïve CBA mice (no-treatment group) were adoptively transferred into secondary CBA recipients with a C57BL/6 heart. To confirm the requirement for 3C10-induced Tregs, we administered an anti-interleukin-2 receptor alpha antibody (PC-61) to secondary CBA recipients. Additionally, histologic and fluorescent staining, cell proliferation analysis, flow cytometry, and donor-specific antibody (DSA) measurements were performed. 3C10/AT-treated CBA recipients resulted in significantly prolonged allograft survival (median survival time [MST], >50 days). Allografts displayed prolonged function with preservation of vessel structure by maintaining high numbers of splenic CD4+CD25+Foxp3+ Treg and intramyocardial CD4+Foxp3+ cells. DSA levels were suppressed in 3C10/AT-treated CBA recipients. Moreover, PC-61 administration resulted in a shorter MSTs of cardiac allograft survivals, a detrimental increase in DSA production, and enhanced expression of programmed cell death (PD)-1. AT of 3C10-induced Tregs may be a promising graft-protective strategy to prolong allograft survival and suppress DSA production, driven by the promotion of splenic and graft-infiltrating Tregs and collaboration with PD-1+ T cells and Treg.

A murine groin site cardiac transplantation model-applicable tool for studying roles of peripheral lymph nodes in transplantation.

The murine heterotopic cardiac transplantation model has been widely used to study antigen-specific immune responses or new immunosuppressive agents, which have a strong correlation with peripheral lymph nodes. Thus, a new organ transplantation model that is applicable to related studies is needed. Here, we describe a groin-site murine heart transplantation model using a cuff technique, in which the donor aorta and pulmonary artery are anastomosed to the truncated femoral vessels of the recipient. The mean survival time (MST) of the grafts in BALB/c-to-C57BL/6 allo-transplant group was 7.2 ± 0.3 days, and 1.9 ± 0.2 days in BALB/c-to-Sprague-Dawley (SD) rat xeno-transplant group. H&E results show that donor hearts from both groups demonstrate typical pathological features at the endpoint. Evans Blue tracing revealed that the popliteal lymph nodes of the grafted side hindlimb are larger than those of the contralateral side. Moreover, IHC staining for CD3, CD20 shows that the germinal center and cortex region of the grafted side of popliteal lymph nodes is apparently increased than that of the contralateral side. To sum up, this model may serve as an ideal model to study the role of peripheral lymph nodes in organ transplant rejection. In addition, extra-peritoneal grafting makes a step forward in animal welfare under the 3Rs' principle (Replacement, Reduction, Refinement).

Noninvasive quantification of granzyme B in cardiac allograft rejection using targeted ultrasound imaging.

Endomyocardial biopsy is the gold standard method for the diagnosis of cardiac allograft rejection. However, it causes damage to the heart. In this study, we developed a noninvasive method for quantification of granzyme B (GzB) in vivo by targeted ultrasound imaging, which detects and provides quantitative information for specific molecules, for acute rejection assessment in a murine cardiac transplantation model. Microbubbles bearing anti-GzB antibodies (MBGzb) or isotype antibodies (MBcon) were prepared. Hearts were transplanted from C57BL/6J (allogeneic) or C3H (syngeneic) donors to C3H recipients. Target ultrasound imaging was performed on Days 2 and 5 post-transplantations. A pathologic assessment was performed. The expression of granzyme B and IL-6 in the heart was detected by Western blotting. After MB injection, we observed and collected data at 3 and 6min before and after the flash pulse. Quantitative analysis revealed that the reduction in peak intensity was significantly higher in the allogeneic MBGzb group than in the allogeneic MBcon group and the isogeneic MBcon group at PODs 2 and 5. In the allogeneic groups, granzyme B and IL-6 expression levels were higher than those in the isogeneic group. In addition, more CD8 T cells and neutrophils were observed in the allogeneic groups. Ultrasound molecular imaging of granzyme B can be used as a noninvasive method for acute rejection detection after cardiac transplantation.

A Modified Murine Heterotopic Heart Transplant Protocol Matching Contemporary Standards of Aseptic Technique, Anesthesia, and Analgesia.

The development of experimental models of cardiac transplantation in animals has contributed to many advances in the fields of immunology and solid organ transplantation. While the heterotopic vascularized murine cardiac transplantation model was initially utilized in studies of graft rejection using combinations of mismatched inbred mouse strains, access to genetically modified strains and therapeutic modalities can provide powerful new preclinical insights. Fundamentally, the surgical methodology for this technique has not changed since its development, especially with respect to important factors such as aseptic technique, anesthesia, and analgesia, which make material impacts on postsurgical morbidity and mortality. Additionally, improvements in perioperative management are expected to provide improvements in both animal welfare and experimental outcomes. This paper reports upon a protocol developed in collaboration with a subject matter expert in veterinary anesthesia and describes the surgical technique with an emphasis on perioperative management. Additionally, we discuss the implications of these refinements and provide details on troubleshooting critical surgical steps for this procedure.

A Modified Murine Heterotopic Heart Transplant Protocol Matching Contemporary Standards of Aseptic Technique, Anesthesia, and Analgesia

The development of experimental models of cardiac transplantation in animals has contributed to many advances in the fields of immunology and solid organ transplantation. While the heterotopic vascularized murine cardiac transplantation model was initially utilized in studies of graft rejection using combinations of mismatched inbred mouse strains, access to genetically modified strains and therapeutic modalities can provide powerful new preclinical insights. Fundamentally, the surgical methodology for this technique has not changed since its development, especially with respect to important factors such as aseptic technique, anesthesia, and analgesia, which make material impacts on postsurgical morbidity and mortality. Additionally, improvements in perioperative management are expected to provide improvements in both animal welfare and experimental outcomes. This paper reports upon a protocol developed in collaboration with a subject matter expert in veterinary anesthesia and describes the surgical technique with an emphasis on perioperative management. Additionally, we discuss the implications of these refinements and provide details on troubleshooting critical surgical steps for this procedure.

The Combination of Rhodosin and MMF Prolongs Cardiac Allograft Survival by Inhibiting DC Maturation by Promoting Mitochondrial Fusion.

Despite being the gold-standard treatment for end-stage heart disease, heart transplantation is associated with acute cardiac rejection within 1 year of transplantation. The continuous application of immunosuppressants may cause side effects such as hepatic and renal toxicity, infection, and malignancy. Developing new pharmaceutical strategies to alleviate acute rejection after heart transplantation effectively and safely is of critical importance. In this study, we performed a murine model of MHC-full mismatch cardiac transplantation and showed that the combination of Rhodosin (Rho) and mycophenolate mofetil (MMF) could prevent acute rejection and oxidative stress injury and prolong the survival time of murine heart transplants. The use of Rho plus MMF in allografts improved the balance of Tregs/Teff cells, which had a protective effect on allotransplantation. We also isolated bone marrow-derived dendritic cells (BMDCs) and determined that Rho inhibited DC maturation by promoting mitochondrial fusion mainly through the mitochondrial fusion-related protein MFN1. Herein, we demonstrated that Rho, an active ingredient isolated from the plant Rhodiola rosea with antioxidant and anti-inflammatory activities, could efficiently alleviate acute rejection and significantly prolong murine heart allograft survival when used with a low dose of MMF. More importantly, we found that Rho restrained DC maturation by promoting mitochondrial fusion and decreasing reactive oxygen species (ROS) levels, which then alleviated acute rejection in murine cardiac transplantation. Interestingly, as a novel immunosuppressant, Rho has almost no side effects compared with other traditional immunosuppressants. Taken together, these results suggest that Rho has good clinical auxiliary applications as an effective immunosuppressant and antioxidant, and this study provides an efficient strategy to overcome the side effects of immunosuppressive agents that are currently used in organ transplantation.

Mouse Heterotopic Cervical Cardiac Transplantation Utilizing Vascular Cuffs.

Murine models of cardiac transplantation are frequently utilized to study ischemia-reperfusion injury, innate and adaptive immune responses after transplantation, and the impact of immunomodulatory therapies on graft rejection. Heterotopic cervical heart transplantation in mice was first described in 1991 using sutured anastomoses and subsequently modified to include cuff techniques. This modification allowed for improved success rates, and since then, there have been multiple reports that have proposed further technical improvements. However, translation into more widespread utilization remains limited due to the technical difficulty associated with graft anastomoses, which requires precision to achieve adequate length and caliber of the cuffs to avoid vascular anastomotic twisting or excessive tension, which can result in damage to the graft. The present protocol describes a modified technique for performing heterotopic cervical cardiac transplantation in mice which involves cuff placement on the recipient's common carotid artery and the donor's pulmonary artery in alignment with the direction of the blood flow.

Effects of Each Domain in Recombinant Human Soluble Thrombomodulin on Prolongation of Murine Cardiac Allograft Survival

Thrombomodulin is used to manage disseminated intravascular coagulation. In our murine heart transplantation model, the administration of recombinant human soluble thrombomodulin (rTM) could induce the prolongation of cardiac allograft survival. However, there are limited data on the graft protective effects of each r domain (D1, D2, and D3). In this study, we investigated the effects of each domain of rTM on alloimmune responses in a murine model of cardiac allograft transplantation. Fully vascularized heterotopic hearts from C57BL/6 donors were transplanted into CBA recipients using microsurgical techniques. CBA mice that underwent transplantation of C57BL/6 cardiac allografts were assigned to 4 groups: no treatment and each domain-exposed group. The dosage of each domain was determined based on our previous experiments. Flow cytometry and histologic studies were performed to determine whether Foxp3+ regulatory T cells were generated. Untreated and D2-exposed CBA recipients acutely rejected C57BL/6 cardiac allografts within 9 days. Administration of D3 resulted in modest prolongation of allograft survival, and administration of D1 significantly prolonged allograft survival. Histologic studies showed that myocardial damage of allografts from D1- and D3-exposed CBA recipients was controlled compared with that of untreated recipients. In particular, the CD4+CD25+Foxp3+ cell population in the splenocytes of D1-exposed CBA recipients was increased. In conclusion, D1 in rTM could help prolong cardiac allograft survival through regulatory T cell induction and graft protective effects.

Evaluation of Cardiac Graft Function by Echocardiography in Mice

Generally, graft function in the murine cardiac allograft transplant model is assessed daily by palpating the heart for evidence of contraction. To our knowledge, few reports have investigated the correlation of cardiac graft function using echocardiography and immunohistochemical studies. In this study, we investigated the efficacy of echocardiographic and histologic evaluation of alloimmune responses in the acute phase of murine cardiac allografts. Fully vascularized heterotopic hearts from CBA (allogeneic group) or C57BL/6 (syngeneic group) donors were transplanted into C57BL/6 recipients using microsurgical techniques. Fluctuations in heart rate, left ventricular ejection fraction (LVEF), left ventricular functional shortening (LVFS), right ventricular outflow tract maximal systolic velocity (RVOT Vmax), and RVOT velocity time integral (RVOT VTI) were evaluated on postoperative days (PODs) 1, 3, 5, 7, and 9 after transplantation using an ultrasonic device. Histologic studies were also performed. The syngeneic group did not show a complete cessation of heartbeat or deterioration of cardiac function. CBA recipients in the allogeneic group rejected cardiac allografts on POD 9 after grafting. LVEF and LVFS in the allogeneic group gradually decreased on POD 9. Consistent with the time-course echocardiographic evaluation, histologic studies showed gradual atrophy of the left ventricle. In contrast, RVOT Vmax and RVOT VTI in the allogeneic group were not significantly different during the observation period. Additionally, the thickness of the right ventricular wall did not change until POD 7. The present findings suggested that echocardiography may help to evaluate time-course murine cardiac graft function through left ventricular parameters such as LVEF and LVFS.

Functional roles of graft‐infiltrating lymphocytes during early‐phase post‐transplantation in mouse cardiac transplantation models

Immunological behavior of graft-infiltrating lymphocytes (GILs) determines the graft fate (i.e., rejection or acceptance). Nevertheless, the functional alloreactivity and the phenotype of GILs at various times during the early post-transplantation phase have not been fully elucidated. We examined the immunological activities of early-phase GILs using a murine model of cardiac transplantation. GILs from 120-h allografts, but not 72-h allografts, showed robust activation and produced proinflammatory cytokines. In particular, a significant increase in CD69+ T-bet+ Nur77+ T cells was detected in 120-h allografts. Furthermore, isolated GILs were used to reconstitute BALB/c Rag2-/- γc-/- (BRG) mice. BRG mice reconstituted with 120-h GILs displayed donor-specific immune reactivity and rejected donor strain cardiac allografts; conversely, 72-h GILs exhibited weak anti-donor reactivity and did not reject allografts. These findings were confirmed by re-transplantation of cardiac allografts into BRG mice at 72-h post-transplantation. Re-transplanted allografts continued to function for >100 days, despite the presence of CD3+ GILs. In conclusion, the immunological behavior of GILs considerably differs over time during the early post-transplantation phase. A better understanding of the functional role of early-phase GILs may clarify the fate determination process in the graft-site microenvironment.

Dominant regulation of long-term allograft survival is mediated by microRNA-142.

Organ transplantation is often lifesaving, but the long-term deleterious effects of combinatorial immunosuppression regimens and allograft failure cause significant morbidity and mortality. Long-term graft survival in the absence of continuing immunosuppression, defined as operational tolerance, has never been described in the context of multiple major histocompatibility complex (MHC) mismatches. Here, we show that miR-142 deficiency leads to indefinite allograft survival in a fully MHC mismatched murine cardiac transplant model in the absence of exogenous immunosuppression. We demonstrate that the cause of indefinite allograft survival in the absence of miR-142 maps specifically to the T cell compartment. Of therapeutic relevance, temporal deletion of miR-142 in adult mice prior to transplantation of a fully MHC mismatched skin allograft resulted in prolonged allograft survival. Mechanistically, miR-142 directly targets Tgfbr1 for repression in regulatory T cells (TREG ). This leads to increased TREG sensitivity to transforming growth factor - beta and promotes transplant tolerance via an augmented peripheral TREG response in the absence of miR-142. These data identify manipulation of miR-142 as a promising approach for the induction of tolerance in human transplantation.

The Natural Killer Cell Receptor NKG2D is Critical to Antibody-Mediated Chronic Rejection in Heart Transplantation

Natural killer (NK) cells are key components of the innate immune system. Prior animal studies have shown that donor-specific antibodies (DSA) in concert with NK cells are sufficient to inflict chronic allograft vasculopathy (CAV), but only with certain donor/recipient combinations. Current understanding of NK cell biology suggests the transition from quiescence to activation is mediated by a network of activating and inhibitory receptors; it is the integration of these signals that determines the final response. We hypothesized that the varying susceptibilities observed to this NK cell-mediated injury were due to differences in either donor activating ligand expression or recipient NK cell phenotype(s). We utilized a murine model of cardiac transplantation with C3H (H-2k) or BALB/c (H-2d) hearts engrafted into immune-deficient C57Bl/6 Rag1-/- (H-2b) recipients. Recipients had no functional T or B cells, but an intact innate immune system. Experimental recipients received monoclonal Class I antibodies (anti-H2k for C3H donors, or anti-H2d for BALB/c donors). Allografts and recipient NK cells were recovered and examined after 30 days. Allografts from C3H donors demonstrated marked neointimal changes consistent with CAV. Conversely, allografts from BALB/c donors were protected despite this donor / recipient combination also representing a fully allogeneic mismatch (Figure 1A). There was no difference in recipient NK cell phenotype or ability to be activated between the two groups. Analysis of allograft endothelial cells from C3H allografts, however, showed significantly higher expression of the activating NKG2D ligand Rae-1 (Figure 1B). Significantly, administration of an NKG2D blocking antibody abrogated the development of vasculopathy in recipients of C3H allografts, even in the presence of DSA (Figure 1A). NKG2D ligand / receptor engagement is necessary in this antibody-dependent form of chronic cardiac allograft vasculopathy.

Role for Circulating Exosomes with Cardiac Self-Antigens (Myosin and Vimentin) in the Pathogenesis of Chronic Rejection in a Murine Heterotopic Model of Cardiac Transplantation

The aim of the study is to determine the of kinetics of circulating exosomes induced with cardiac self-antigens (SAgs) (Myosin, Vimentin) and their role in de novo development of antibodies (Abs) to SAgs leading to chronic rejection following heterotopic cardiac transplantation (HTx). Allogenic (BALB/c to C57BL/6) HTx was performed heterotopically in the abdominal cavity. Costimulatory blockade consisting of MR1 (250 μg i.p.) and CTLA4-Ig (200 μg i.p.) treatment (days 0 and 2, respectively) resulted in prolongation of HTx for 45-60 days. However, histopathological analysis demonstrated chronic rejection as evidenced by myocyte damage, cellular infiltration with mononuclear cells and fibrosis. Sera were collected on days 7, 15, 30, and 45 for kinetic analysis of exosome induction, Ab development, and characterization of exosomes for cardiac SAgs, transcription factors, class II MHC trans-activator (CIITA), nuclear factor κB (NF-κB) and 20S proteasome by western blot using specific Abs. BALB/c to C57BL/6 HTx rejected heart on day 7 to 8. Sera, at the time of rejection, demonstrated exosomes with SAgs, CIITA, NF-κB and 20S proteasome. HTx done following costimulatory blockade developed chronic rejection between 45 to 60 days. Kinetic studies demonstrated induction of circulating exosomes containing SAgs; Myosin (3.3 vs 1.09; p<0.05) and Vimentin (4 vs 1.35; p<0.01), CIITA (29.4 vs 1.55; p<0.01), NF-κB (2.3 vs 1.2; p<0.05) respectively on day 15 following transplantation. 20S proteasome levels were elevated on day 30 and 45 (5.4 & 9.0 vs 1.49; p<0.01). Development of Abs to Myosin also occurred on day 15 (772±557 vs 187±50; p<0.01) and persisted till day 45 (1289±409 vs 187±50) when chronic rejection of HTx noticed. Circulating exosomes containing SAgs, transcription factors, and development of Abs to SAgs preceded development of chronic rejection in a murine model of chronic rejection occurring after co-stimulation blockade in allogenic HTx, thus, supporting an important role for circulating exosomes induced following HTx in breaking the tolerance induced by co-stimulation blockade resulting in immune responses leading to chronic rejection.

Notch-1 Inhibition Promotes Immune Regulation in Transplantation Via Regulatory T Cell-Dependent Mechanisms.

Transplantation is the treatment of choice for many patients with end-stage organ disease. Despite advances in immunosuppression, long-term outcomes remain suboptimal, hampered by drug toxicity and immune-mediated injury, the leading cause of late graft loss. The development of therapies that promote regulation while suppressing effector immunity is imperative to improve graft survival and minimize conventional immunosuppression. Notch signaling is a highly conserved pathway pivotal to T-cell differentiation and function, rendering it a target of interest in efforts to manipulate T cell-mediated immunity. We investigated the pattern of Notch-1 expression in effector and regulatory T cells (Tregs) in both murine and human recipients of a solid-organ transplant. Using a selective human anti-Notch-1 antibody (aNotch-1), we examined the effect of Notch-1 receptor inhibition in full major histocompatibility complex-mismatch murine cardiac and lung transplant models, and in a humanized skin transplant model. On the basis of our findings, we further used a genetic approach to investigate the effect of selective Notch-1 inhibition in Tregs. We observed an increased proportion of Tregs expressing surface and intracellular (activated) Notch-1 in comparison with conventional T cells, both in mice with transplants and in the peripheral blood of patients with transplants. In the murine cardiac transplant model, peritransplant administration of aNotch-1 (days 0, 2, 4, 6, 8, and 10) significantly prolonged allograft survival in comparison with immunoglobulin G-treated controls. Similarly, aNotch-1 treatment improved both histological and functional outcomes in the murine lung transplant model. The use of aNotch-1 resulted in a reduced proportion of both splenic and intragraft conventional T cells, while increasing the proportion of Tregs. Furthermore, Tregs isolated from aNotch-1-treated mice showed enhanced suppressive function on a per-cell basis, confirmed with selective Notch-1 deletion in Tregs (Foxp3EGFPCreNotch1fl/fl). Notch-1 blockade inhibited the mammalian target of rapamycin pathway and increased the phosphorylation of STAT5 (signal transducer and activator of transcription 5) in murine Tregs. Notch-1low Tregs isolated from human peripheral blood exhibited more potent suppressive capacity than Notch-1high Tregs. Last, the combination of aNotch-1 with costimulation blockade induced long-term tolerance in a cardiac transplant model, and this tolerance was dependent on CTLA-4 (cytotoxic T-lymphocyte-associated antigen-4) signaling. Our data reveal a promising, clinically relevant approach for immune modulation in transplantation by selectively targeting Notch-1.

Adoptive Transfer of HVEM signal induced Alloreacitve Regulatory T cell Protect Rejection in Allogeneic Murine Cardiac Transplantation Model.

Background Donor antigen specific immunosuppression is ideal strategy in organ transplantation to decrease the risk of life-long immunosuppression. Material and Method Donor reactive FOXP3 + regulatory T cell were generated from hCD2-FOXP3 reporter C57BL/6 background mouse splenocyte with pre-coated HVEM agonistic mAb and irradiated donor splenocyte and purified by magnetic sorting. This donor reactive regulatory T cell were cocultured with naïve splenocyte stimulated by donor antigen and adoptively transfer into transplanted mouse to evaluate their protection for graft rejection. Results The HVEM induced alloreavitve hCD2+ regulatory T cell suppress anti-donor response more than non-treated alloreactive hCD2+ regulatory nor naïve hCD2+ regulatory T cell. Graft survival was significantly prolonged in the cell therapy group compared with allogeneic transplants ( Log Rank p<0.05).Conclusion HVEM agonistic signal enhance suppressive function in FOXP3+ alloreacitve regulatory T cells. This cell therapy might be option to protect graft rejection.

Seven Japanese Herbals Prolonged Cardiac Allograft Survival

Japanese herbal medicines have long been used as alternative therapy because of their immunomodulatory effects. In recent years, use herbal medicines is rapidly increasing worldwide. In this study, we investigated the effect of 17 components of traditional Japanese herbal medicines on alloimmune responses in a murine model of cardiac allograft transplantation. Fully vascularized heterotopic hearts from C57BL/6 donors were transplanted into CBA mice by using microsurgical techniques. Artemisiae capillaris herba (Inchinko) was given to CBA recipients at a dosage of 1 g/kg/day from the day of transplantation until 7 days afterward. The other 16 components were given at a dosage of 2 g/kg/day for the same time period. Naïve CBA mice rejected C57BL/6 cardiac grafts acutely (median survival time [MST] of 7 days). CBA transplant recipients given 2 g/kg/day of Glycyrrhizae radix (Kanzou), Poria sclerotium (Bukuryo), Pinellia tuber (Hange), Cnidii rhizome (Senkyu), Paeoniae radix (Shakuyaku), and Scutellariae radix (Ogon) had prolonged C57BL/6 allograft survival significantly (MSTs were 18, 18, 17, 14, 12, and 12 days, respectively). Moreover, CBA transplant recipients given 1g/kg/day of Artemisiae capillaris herba had prolonged C57BL/6 allograft survival (MST >100 days); however, none of other 10 components prolonged allograft survival. In conclusion, administration of 7 components of traditional Japanese herbal medicines might induce prolongation of fully major histocompatibility complex–mismatched cardiac allografts.

Administration of Thrombomodulin (CD141) Could Improve Cardiac Allograft Survival in Mice

Thrombomodulin (TM) is a promising natural anti-coagulant therapeutic protein that is effective in the treatment of disseminated intravascular coagulation. However, the mechanisms by which TM on micro-vessels enable the regulation of intimal hyperplasia remain elusive. We investigated the graft-protective effects of TM in a fully major histocompatibility complex-mismatched murine cardiac allograft transplantation model. CBA recipients transplanted with a C57BL/6 heart received intraperitoneal administration of 0.2, 2.0, and 20.0 μg/day of TM for 8 days. Histological staining was conducted to assess the degree of inflammation and infiltration in the transplanted cardiac grafts. Untreated CBA recipients rejected C57BL/6 cardiac grafts acutely (median survival time [MST] was 7 days). CBA recipients exposed to the above dosages had significantly prolonged allograft survival (MSTs were 16, 21, and 37.5 days, respectively). Histologic assessments from TM-exposed recipients 2 weeks after grafting showed that the myocardium and vessel structure in their allografts were clearly preserved, and that the infiltration of inflammatory cells around coronary arteries was suppressed. TM can induce the prolongation of fully major histocompatibility complex-mismatched cardiac allograft by exerting graft protective effects within the myocardium and coronary arteries.

Rikkunshito (TJ-43) Improved Reduction of Food Intake in a Murine Cardiac Transplantation Model

Rikkunshito (TJ-43), an eight-component traditional Japanese herbal medicine, has been used in clinics for gastritis, vomiting, and appetite loss. We investigated the effects of TJ-43 on the amelioration of appetite loss in the surgical-exposed model of murine cardiac allograft transplantation. CBA mice underwent transplantation of a CBA (syngeneic group) or C57BL/6 heart (allogeneic group) and received oral administration of 2 g/kg/d of TJ-43 from the day of transplantation until 7 days afterward. The amount of food intake (FI) and weight change after operation were recorded from 1 to 28 postoperative days. The allogeneic group had less average amounts of FI for 1 week compared with the syngeneic group (FI was 1.90 ± 0.43 g and 2.66 ± 0.46 g, respectively). Average FIs between the syngeneic and allogeneic groups with TJ-43 for 1 week were 2.36 ± 0.44 g and 2.30 ± 0.13 g, respectively, and those with distilled water were 2.66 ± 0.46 g and 1.90 ± 0.43 g, respectively, suggesting that exposure with TJ-43 tended to ameliorate the reduction of FI. Similarly, the effect on the amelioration of average FI in syngeneic and allogeneic groups exposed for 2 weeks was confirmed. However, exposure to with TJ-43 had no effects on FI after 4 weeks. TJ-43 could prevent reduction of average FI induced by the surgical-exposed model of murine cardiac allograft transplantation.

Complete Genome Sequence of a Strain of Bifidobacterium pseudolongum Isolated from Mouse Feces and Associated with Improved Organ Transplant Outcome.

ABSTRACTHere, we report the complete genome sequence of Bifidobacterium pseudolongum strain UMB-MBP-01, isolated from the feces of C57BL/6J mice. This strain was identified in microbiome profiling studies and associated with improved transplant outcome in a murine model of cardiac heterotypic transplantation.