5-Methoxytryptophan attenuates postinfarct cardiac injury by controlling oxidative stress and immune activation.

AIMS: Myocardial infarction (MI) remains a major cause of heart failure. 5-Methoxytryptophan (5-MTP), a 5-methoxyindole metabolite of L-tryptophan, exerts anti-inflammatory and antifibrotic effects, but MI impairs the biosynthesis of cardiac 5-MTP. Therefore, we evaluated the effect of exogenous 5-MTP administration on rescuing post-MI cardiac injury. METHODS AND RESULTS: After a detailed pharmacokinetic analysis of 5-MTP, Sprague Dawley rats that had undergone left anterior descending coronary artery ligation received intraperitoneal administration of either 17 mg/kg 5-MTP or saline at 0.5 and 24 h after MI. Cardiac systolic function, infarction size, and fibrosis were evaluated using echocardiography, triphenyltetrazolium chloride staining, and Masson trichrome staining, respectively. Myocardial apoptosis was analyzed by staining for caspase-3 and cardiac troponin I. 5-MTP treatment decreased the infarct area and myocardial apoptosis; attenuated systolic dysfunction and left ventricular dilatation; and reduced cardiomyocyte hypertrophy, myocardial fibrosis, and infarct expansion. Crucially, 5-MTP alleviated oxidative stress by preserving mitochondrial antioxidant enzymes and downregulating reactive oxygen species-generating NADPH oxidase isoforms and endothelin-1. Consequently, 5-MTP-treated MI rat hearts exhibited lower levels of chemokines and cytokines, namely interleukin (IL)-1ß, IL-18, IL-6, C-C motif chemokine ligand (CCL)-2, and CCL5, accompanied by reduced infiltration of CD11b+ cells and CD4+ T cells. Notably, 5-MTP protected against H2O2-induced damage in HL-1 cardiomyocytes and human umbilical vein endothelial cells in vitro. CONCLUSION: 5-MTP prevented post-MI cardiac injury by promoting mitochondrial stabilization and controlling redox imbalance. This cytoprotective effect ameliorated macrophage and T-cell infiltration, thus reducing the infarct size, attenuating fibrosis, and restoring myocardial function.

Butyrate modulates adipose-derived stem cells isolated from polygenic obese and diabetic mice to drive enhanced immunosuppression.

BACKGROUND AIMS: Adipose-derived stem cells (ASCs) offer promising therapeutic possibilities for immunomodulation. Butyrate (BA) exerts potent anti-inflammatory effects and exhibits multiple regulatory functionalities in adipose tissue (AT). The authors aimed to explore whether BA modulates ASCs to augment their immunosuppressive capabilities. METHODS: The authors examined the potency of BA and ASCs for controlling anti-CD3 plus CD28-stimulated splenocyte proliferation in vitro, both in combination and with pre-treatment. Further, the authors investigated genes specifically upregulated by BA-treated ASCs, which were harvested from ASC-splenocyte co-culture after the removal of floating splenocytes. In addition, the authors investigated the influence of oral BA supplementation on the ex vivo immunosuppressive potency of ASCs from BALB/c and Tsumura, Suzuki, obese, diabetes (TSOD) mice. RESULTS: BA enhanced the immunosuppressive potency of ASCs when directly added to ASC-splenocyte co-cultures or via pre-conditioning treatment. The percentages of ASC-induced Foxp3+ regulatory T cells increased, whereas the numbers of ASC-suppressed T helper 17 cells further decreased after BA exposure. The messenger RNA expression levels of inducible nitric oxide (NO) synthase (iNOS), chemokines, IL-10 and amphiregulin in ASCs co-cultured with activated splenocytes were upregulated after incubation with BA. This was accompanied by an amplification of iNOS-inducing cytokines, interferon gamma and tumor necrosis factor alpha in the ASC-splenocyte co-culture, triggering ASCs to produce high NO levels under the influence of BA. Mechanistically, the authors detected BA-mediated acetylated histone H3 in ASCs. BA treatment consistently improved the immunosuppressive potency of ASCs derived from both BALB/c and TSOD mice. CONCLUSIONS: The use of BA to counteract metaflammation by restoring the defective immunomodulation of ASCs from dysregulated AT in obese donors is recommended.

Copy number variant hotspots in Han Taiwanese population induced pluripotent stem cell lines - lessons from establishing the Taiwan human disease iPSC Consortium Bank.

BACKGROUND: The Taiwan Human Disease iPSC Service Consortium was established to accelerate Taiwan's growing stem cell research initiatives and provide a platform for researchers interested in utilizing induced pluripotent stem cell (iPSC) technology. The consortium has generated and characterized 83 iPSC lines: 11 normal and 72 disease iPSC lines covering 21 different diseases, several of which are of high incidence in Taiwan. Whether there are any reprogramming-induced recurrent copy number variant (CNV) hotspots in iPSCs is still largely unknown. METHODS: We performed genome-wide copy number variant screening of 83 Han Taiwanese iPSC lines and compared them with 1093 control subjects using an Affymetrix genome-wide human SNP array. RESULTS: In the iPSCs, we identified ten specific CNV loci and seven "polymorphic" CNV regions that are associated with the reprogramming process. Additionally, we established several differentiation protocols for our iPSC lines. We demonstrated that our iPSC-derived cardiomyocytes respond to pharmacological agents and were successfully engrafted into the mouse myocardium demonstrating their potential application in cell therapy. CONCLUSIONS: The CNV hotspots induced by cell reprogramming have successfully been identified in the current study. This finding may be used as a reference index for evaluating iPSC quality for future clinical applications. Our aim was to establish a national iPSC resource center generating iPSCs, made available to researchers, to benefit the stem cell community in Taiwan and throughout the world.

Lymphocyte-activation gene 3(+) (LAG3(+)) forkhead box protein 3(-) (FOXP3(-)) regulatory T cells induced by B cells alleviates joint inflammation in collagen-induced arthritis.

Rheumatoid arthritis (RA) is an autoimmune disease in which dysregulated immune cells primarily target synovial joints. Despite recent advances in the treatment of RA, including the introduction of biologic therapies and employment of combination disease-modifying antirheumatic drug strategies, remission rates remain suboptimal. Previous studies have demonstrated that the adoptive transfer of induced regulatory T cells (iTregs) was effective in treating a murine model of collagen-induced arthritis (CIA). The objective of this study was to develop optimal potential iTreg-based therapy for CIA by adoptively transferring LAG3(+) Treg-of-B cells. B-cell-induced Treg-of-B cells expressed LAG3 but not Foxp3 (designated LAG3(+) Treg-of-B), and secreted IL-4, IL-10, and TGF-ß. Furthermore, LAG3(+) Treg-of-B cells suppressed the proliferation of CD4(+)CD25(-) responder T cells through both LAG3 and IL-10 production. In the murine CIA model, adoptive transfer of LAG3(+) Treg-of-B cells alleviated the joint severity as well as local and systemic inflammation. Treatment with LAG3(+) Treg-of-B cells also promoted IL-10 production in lymphocytes isolated from the spleen and draining lymph nodes. Moreover, mice receiving LAG3(+) Treg-of-B cell treatment showed significantly less pronounced osteolysis in the hind footpads, which correlated with the downregulation of tartrate-resistant acid phosphatase expression. In conclusion, we identified a novel subset of Tregs for CIA treatment. This insight may facilitate exploring novel regulatory T-cell-based therapies for human autoimmune diseases.

Drug-related problems vary with medication category and treatment duration in Taiwanese heart failure outpatients receiving case management.

BACKGROUND/PURPOSE: Heart failure (HF) patients are at high risk of having drug-related problems (DRPs). We aim to describe the frequency, types, and temporal occurrence of DRPs in Taiwanese HF outpatients receiving case management. METHODS: In this study, we included 141 patients from HF clinics in three hospitals in Taiwan from October 2008 to December 2010. Nurse case managers at each of the participating sites registered case report forms (CRFs) for patients during clinic visits. DRPs were classified using the Pharmaceutical Care Network Europe Foundation (PCNE) classification system and documented by pharmacists after reviewing CRFs and participating in multidisciplinary team discussions. RESULTS: For 141 clinic participants, the average duration of medication use was 17 months, and 796 DRPs were reported. The DRPs most frequently recorded were the need for laboratory tests (32.7% of total DRPs), followed by potential interaction (29.6%), nonallergic side effects (13.3%), and insufficient awareness of health and disease (9.5%). The drugs most frequently causing a DRP were angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers, diuretics, warfarin, spironolactone, and ß-blockers. The incidence rates of total DRPs was maximal during the initial 3 months of medication treatment, whereas the incidence rates of each category of DRPs showed multiform changes over time among various drug classes. CONCLUSION: In Taiwan where the clinical pharmacist system is not well organized, HF outpatients still had a high prevalence of DRPs despite intensive monitoring by nurse case managers. Clinical pharmacists play critical roles in detecting potential DRPs during long-term medication treatment for this population.

Prostaglandin E2 potentiates mesenchymal stem cell-induced IL-10+IFN-γ+CD4+ regulatory T cells to control transplant arteriosclerosis.

Mesenchymal stem cells (MSCs) are known for their immunomodulatory functions. We previously demonstrated that bone marrow-derived MSCs effectively control transplant arteriosclerosis (TA) by enhancing IL-10(+) and IFN-γ(+) cells. The objective of this study is to elucidate the mechanism by which MSCs induce IL-10(+)IFN-γ(+)CD4(+) regulatory T type 1 (T(R)1)-like cells. In an MLR system using porcine PBMCs, MSC-induced IL-10(+)IFN-γ(+)CD4(+) cells, which confer resistance to allogeneic proliferation in an IL-10-dependent manner, resemble T(R)1-like cells. Both cyclooxygenase-derived PGE(2) and IDO help to induce T(R)1-like cells by MSCs. MSCs constitutively secrete PGE(2), which is augmented in allogeneic reactions. However, T(R)1-like cells were deficient in PGE(2) and 4-fold less potent than were MSCs in suppressing MLR. PGE(2) mimetic supplements can enhance the immunosuppressive potency of T(R)1-like cells. In a porcine model of allogeneic femoral arterial transplantation, MSC-induced T(R)1-like cells combined with PGE(2), but not either alone, significantly reduced TA at the end of 6 wk (percentage of luminal area stenosis: T(R)1-like cells + PGE(2): 11 ± 10%; PGE(2) alone: 93 ± 8.7%; T(R)1-like cells alone: 88 ± 2.4% versus untreated 94 ± 0.9%, p < 0.001). These findings indicate that PGE(2) helps MSC-induced IL-10(+)IFN-γ(+)CD4(+) T(R)1-like cells inhibit TA. PGE(2) combined with MSC-induced T(R)1-like cells represents a new approach for achieving immune tolerance.

Non-steroidal anti-inflammatory drugs, renin-angiotensin system blockade or diuretics and risk of acute kidney injury: A case-crossover study.

BACKGROUND: Aging-related physiological changes, such as decline in renal function, not only exacerbates pre-existing comorbidities but also escalate the susceptibility to adverse events. Previous studies have shown that non-steroidal anti-inflammatory drugs (NSAIDs) are associated with an increased risk of acute kidney injury (AKI), and the concomitant use of renin-angiotensin system blockade or diuretics may further potentiate the risk. However, studies evaluating the risk of AKI associated with NSAIDs (including routes, concomitant use of different NSAIDs, categories (traditional NSAIDs or COX-2 inhibitors), and cumulative doses of NSAIDs) are limited, particularly the risk of AKI associated with the dual or triple combination of NSAIDs with renin-angiotensin system blockade (RAS blockades) and/or diuretics. METHODS: A case-crossover study utilized two sets of longitudinal data from Taiwan's National Health Insurance Research Database (NHIRD). Newly admitted patients with a primary AKI diagnosis were included, with the index date defined as the first admission date. The 1-7 days and 181-187 days prior to the index date served as the case and control periods. Exposure to NSAIDs and co-exposures of RAS blockade and/or diuretics were assessed in both periods. Multivariable conditional logistic regression models, adjusting for potential confounders, estimated adjusted odds ratios (aORs) and 95 % confidence intervals (CIs) for AKI associated with NSAIDs, dual, or triple combinations. Sensitivity analyses explored result robustness by varying case and control period lengths. RESULTS: The study included 1,284 newly diagnosed AKI patients. NSAIDs showed a 3.55-fold increased risk of AKI (aOR: 3.55; 95 % CI 2.70-4.65), with similar risks for traditional NSAIDs and COX-2 inhibitors. Use of multiple NSAIDs, parenteral dosage forms, and higher cumulative doses increased AKI risk. Dual combination with either RAS blockade or diuretics resulted in a 2.90-fold (aOR: 2.90; 95 %CI 1.47-5.70) and 12.68-fold (aOR: 12.68; 95 %CI 6.15-26.12) risk, respectively. The highest risk occurred with triple combination (aOR: 29.22; 95 %CI 12.82-66.64). CONCLUSIONS: NSAIDs, including both non-selective NSAIDs and COX2 inhibitors, elevate the risk of AKI. Increased AKI risk is linked to using multiple NSAIDs, the parenteral dosage form, and higher cumulative doses. Dual combination of RAS blockade with NSAIDs or diuretics with NSAIDs, as well as triple therapy, heightens the risk, with the latter associated with the highest risk of AKI.

The Worsening Renal Perfusion Index Predicts the Prognoses of Heart Failure Patients Treated with Sacubitril/Valsartan.

INTRODUCTION: Sacubitril/valsartan (S/V) reduces all-cause mortality in patients with heart failure with reduced ejection fraction (HFrEF), but it may decline their estimated glomerular filtration rates (eGFR). In addition to eGFR, this clinical study aimed to develop a blood urea nitrogen (BUN)-based index to evaluate the status of renal perfusion and then identify predictors of all-cause death or heart transplant in patients with HFrEF receiving S/V. METHODS: From the recruited 291 patients with HFrEF who were prescribed S/V from March 2017 to March 2019, we collected demographic, drug history, laboratory, echocardiographic, and clinical data from 1 year before S/V initiation until December 2020. Regression analysis was conducted by fitting Cox's models with time-dependent covariates for the survival time and applying the modern stepwise variable selection procedure. The smoothing spline method was used to detect nonlinearity in effect and yield optimal cut-off values for continuous covariates. RESULTS: In the Cox's model, decreased hemoglobin level, decreased mean left ventricular ejection fraction, declined daily dose of S/V, decreased eGFR within 3 months, and increased BUN levels within 1 month and 9 months over time were significantly associated with an increased risk of all-cause death or heart transplant in patients with HFrEF. CONCLUSIONS: Adequate maintenance of renal perfusion is crucial for the continuous use of S/V and to avoid worsening renal function in patients with HFrEF. We defined the maximum increase in BUN levels within a specified period as the Worsening Renal Perfusion Index (WRPSV Index) to capture the prognostic effect of renal hypoperfusion in patients with HFrEF.

Anemia warrants treatment to improve survival in patients with heart failure receiving sacubitril-valsartan.

Angiotensin inhibition remains a cornerstone for pharmacologic management of heart failure (HF), despite being associated with decreased hemoglobin (Hb) levels. To investigate the effect of anemia and its treatment on patients with HF treated with sacubitril-valsartan (S/V), we conducted a retrospective study involving patients with recorded left ventricular ejection fractions (LVEFs) of < 40% between January 2017 and December 2019. We identified 677 patients, 37.7% of whom received S/V. The median follow-up period was 868 days. Anemia was associated with significantly decreased survival, increased mortality rates, and higher all-cause hospitalizations in S/V-using patients. We further analyzed 236 patients with HF who had recorded renal function, LVEF, and Hb at the initiation of S/V therapy to identify Hb patterns after S/V therapy. Of these patients, 35.6% exhibited decreasing Hb 12 months after S/V initiation, which was associated with a lower survival rate. Among the patients who were not prescribed anemia medications, Hb of ≥ 12 (vs. < 12 g/dL) was associated with a higher survival rate; this association was absent among the patients undergoing anemia treatment. These results emphasize that consistent screening and treatment for anemia should be implemented to reduce the morbidity and mortality of patients with HF receiving S/V.

Population-based high-throughput toxicity screen of human iPSC-derived cardiomyocytes and neurons.

In this study, we establish a population-based human induced pluripotent stem cell (hiPSC) drug screening platform for toxicity assessment. After recruiting 1,000 healthy donors and screening for high-frequency human leukocyte antigen (HLA) haplotypes, we identify 13 HLA-homozygous "super donors" to represent the population. These "super donors" are also expected to represent at least 477,611,135 of the global population. By differentiating these representative hiPSCs into cardiomyocytes and neurons we show their utility in a high-throughput toxicity screen. To validate hit compounds, we demonstrate dose-dependent toxicity of the hit compounds and assess functional modulation. We also show reproducible in vivo drug toxicity results using mouse models with select hit compounds. This study shows the feasibility of using a population-based hiPSC drug screening platform to assess cytotoxicity, which can be used as an innovative tool to study inter-population differences in drug toxicity and adverse drug reactions in drug discovery applications.

The HER2 inhibitor lapatinib potentiates doxorubicin-induced cardiotoxicity through iNOS signaling.

Rationale: Lapatinib (LAP) is a crucial alternative to trastuzumab upon the onset of drug resistance during treatment of metastatic human epidermal growth factor receptor 2-positive breast cancer. Like trastuzumab, LAP is commonly used alongside anthracyclines as a combination therapy, due to enhanced anti-cancer efficacy. However, this is notably associated with cardiotoxicity so it is imperative to understand the mechanisms driving this cardiotoxicity and develop cardioprotective strategies. To this end, here we utilize human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs), which exhibit several characteristics representative of in vivo cardiomyocytes that make them breakthrough models to study drug toxicity. Methods: We investigated LAP- and doxorubicin (DOX)-induced toxicity in hPSC-CMs and evaluated the involvement of inducible nitric oxide (NO) synthase (iNOS). The significance of iNOS-mediated cardiotoxicity was furthermore evaluated in animal studies. Results: LAP synergistically increased DOX toxicity in hPSC-CMs in a dose- and time-dependent manner. At concentrations that were otherwise non-apoptotic when administered separately, LAP significantly potentiated DOX-induced hPSC-CM apoptosis. This was accompanied by increased iNOS expression and pronounced production of NO. iNOS inhibition significantly reduced hPSC-CM sensitivity to LAP and DOX co-treatment (LAP-plus-DOX), leading to reduced apoptosis. Consistent with our observations in vitro, delivery of an iNOS inhibitor in mice treated with LAP-plus-DOX attenuated myocardial apoptosis and systolic dysfunction. Moreover, inhibition of iNOS did not compromise the anti-cancer potency of LAP-plus-DOX in a murine breast cancer xenograft model. Conclusions: Our findings suggest that iNOS inhibition is a promising cardioprotective strategy to accompany HER2-inhibitor/anthracycline combination therapies. Furthermore, these results support the promise of hPSC-CMs as a platform for investigating cardiotoxicity and developing cardioprotectants as a whole.

CXCR4 Antagonist Reduced the Incidence of Acute Rejection and Controlled Cardiac Allograft Vasculopathy in a Swine Heart Transplant Model Receiving a Mycophenolate-based Immunosuppressive Regimen.

BACKGROUND: CXC motif chemokine receptor 4 (CXCR4) blockade is pursued as an alternative to mesenchymal stem cell treatment in transplantation based on our previous report that burixafor, through CXCR4 antagonism, mobilizes immunomodulatory mesenchymal stem cells. Here, we explored the efficacy of combining mycophenolate mofetil (MMF)-based immunosuppressants with repetitive burixafor administration. METHODS: Swine heterotopic cardiac allograft recipients received MMF and corticosteroids (control, n = 10) combined with burixafor as a 2-dose (burixafor2D, n = 7) or 2-dose plus booster injections (burixafor2D + B, n = 5) regimen. The efficacy endpoints were graft survival, freedom from first acute rejection, and the severity of intimal hyperplasia. Each specimen was sacrificed either at its first graft arrest or after 150 days. RESULTS: After 150 days, all specimens in the control group had died, but 28.5% of the burixafor2D group survived, and 60% of the burixafor2D + B group survived (P = 0.0088). Although the control group demonstrated acute rejection at a median of 33.5 days, the burixafor2D + B group survived without acute rejection for a median of 136 days (P = 0.0209). Burixafor administration significantly attenuated the incidence rate of acute rejection (P = 0.002) and the severity of intimal hyperplasia (P = 0.0097) at end point relative to the controls. These findings were associated with reduced cell infiltrates in the allografts, and modulation of C-reactive protein profiles in the circulation. CONCLUSIONS: The augmentation of conventional MMF plus corticosteroids with a CXCR4 antagonist is potentially effective in improving outcomes after heart transplantation in minipigs. Future studies are warranted into optimizing the therapeutic regimens for humans.

Risk of pneumonia in patients with gastroesophageal reflux disease: A population-based cohort study.

PURPOSE: The prevalence of gastroesophagel reflux disease (GERD) has steadily increased. However, the association between GERD itself and the risk of pneumonia remains unclear. This study aimed to investigate the association between GERD and long-term risk of pneumonia and to identify the major risk factors for pneumonia in GERD patients. METHODS: Using the Taiwan National Health Insurance Research Database, we identified patients who were newly diagnosed with GERD and treated with proton pump inhibitors (PPIs) from January 1, 2004 through December 31, 2010. Two groups comprising 15,715 GERD cases and 15,715 non-GERD matched controls were generated using propensity score matching, thereby making the differences in basic demographics, concomitant medication use, and comorbidities between the two groups inconsiderable. RESULTS: Cumulative incidence of pneumonia was significantly higher in the patients with GERD than that in the non-GERD matched controls, with an adjusted HR of 1.48 (95% confidence interval [CI] = 1.31-1.67; P < 0.001) within 6-year follow-ups. Multivariate stratified analyses revealed similar results in many subgroups, with a highest risk in individuals younger than 40 years of age (HR = 2.17, 95% CI = 1.48-3.19). Crucially, patients with GERD using PPIs longer than 4 months were at a significantly increased risk of pneumonia than those who did not use PPIs or took PPIs less than 4 months. CONCLUSIONS: GERD was significantly associated with long-term risk of pneumonia, especially in GERD with PPI use longer than 4 months or in the young population. Further prospective longitudinal studies should be conducted for validation and implementing clinical practice guidelines.

CXCR4 Antagonist TG-0054 Mobilizes Mesenchymal Stem Cells, Attenuates Inflammation, and Preserves Cardiac Systolic Function in a Porcine Model of Myocardial Infarction.

Interaction between chemokine stromal cell-derived factor 1 and the CXC chemokine receptor 4 (CXCR4) governs the sequestration and mobilization of bone marrow stem cells. We investigated the therapeutic potential of TG-0054, a novel CXCR4 antagonist, in attenuating cardiac dysfunction after myocardial infarction (MI). In miniature pigs (minipigs), TG-0054 mobilized CD34(+)CXCR4(+), CD133(+)CXCR4(+), and CD271(+)CXCR4(+) cells into peripheral circulation. After isolation and expansion, TG-0054-mobilized CD271(+) cells were proved to be mesenchymal stem cells (designated CD271-MSCs) since they had trilineage differentiation potential, surface markers of MSCs, and immunosuppressive effects on allogeneic lymphocyte proliferation. MI was induced in 22 minipigs using balloon occlusion of the left anterior descending coronary artery, followed by intravenous injections of 2.85 mg/kg of TG-0054 or saline at 3 days and 7 days post-MI. Serial MRI analyses revealed that TG-0054 treatment prevented left ventricular (LV) dysfunction at 12 weeks after MI (change of LV ejection fraction from baseline, -1.0 ± 6.2% in the TG-0054 group versus -7.9 ± 5.8% in the controls). The preserved cardiac function was accompanied by a significant decrease in the myocardial expression of TNF-α, IL-1ß, and IL-6 at 7 days post-MI. Moreover, the plasma levels of TNF-α, IL-1ß, and IL-6 were persistently suppressed by the TG-0054 treatment. Infusion of TG-0054-mobilized CD271-MSCs reduced both myocardial and plasma cytokine levels in a pattern, which is temporally correlated with TG-0054 treatment. This study demonstrated that TG-0054 improves the impaired LV contractility following MI, at least in part, by mobilizing MSCs to attenuate the postinfarction inflammation. This insight may facilitate exploring novel stem cell-based therapy for treating post-MI heart failure.

Autologous mesenchymal stem cells prevent transplant arteriosclerosis by enhancing local expression of interleukin-10, interferon-γ, and indoleamine 2,3-dioxygenase.

Transplant arteriosclerosis (TA) remains the major limitation of long-term graft survival in heart transplantation despite the advances in immunosuppressants. Mesenchymal stem cells (MSCs) have been demonstrated to suppress allogeneic immune responses by numerous in vitro studies. However, the immunomodulatory effects of MSCs in vivo are controversial and the underlying molecular mechanisms are not conclusive. In this study, we investigated the therapeutic potential of autologous bone marrow-derived MSCs on TA in a porcine model of femoral artery transplantation. MSCs or saline were injected into the soft tissue surrounding the arterial grafts immediately postanastomosis. Four weeks after transplantation, neointimal formation increased significantly in untreated allografts compared with the MSC-treated grafts as assessed by intravascular ultrasound (maximum luminal area stenosis: 40 ± 12% vs. 18 ± 6%, p < 0.001). Grafts harvested at 4 weeks showed dense perivascular lymphocyte infiltration accompanied by significant intimal hyperplasia in the untreated but not in the MSC-treated allografts. Serial angiographic examination showed that all of the untreated allografts became occluded at the 8th week whereas the majority of the MSC-treated grafts remained patent at the 12th week posttransplantation (n = 12 each group, p < 0.001). Quantitative PCR analysis revealed that Foxp3 expression was comparable between the untreated and the MSC-treated groups. However, expression of interleukin-10 (IL-10), interferon-γ (IFN-γ), and indoleamine 2,3-dioxygenase (IDO) was increased significantly in the MSC-treated allografts compared with that in the allograft controls (p = 0.021 for IL-10, p = 0.003 for IFN-γ, and p = 0.008 for IDO). In conclusion, local delivery of autologous MSCs alleviates TA by inducing allograft tolerance via enhanced expression of IL-10, IFN-γ, and IDO but not Foxp3-positive cells in the vessel wall. These results suggest that MSCs induce immune tolerance by activating the type 1 regulatory T-like cells.