BACKGROUND: T cell dysfunction, which includes exhaustion, anergy, and senescence, is a distinct T cell differentiation state that occurs after antigen exposure. Although T cell dysfunction has been a cornerstone of cancer immunotherapy, its potential in transplant research, while not yet as extensively explored, is attracting growing interest. Interferon regulatory factor 4 (IRF4) has been shown to play a pivotal role in inducing T cell dysfunction. METHODS: A novel ultra-low-dose combination of Trametinib and Rapamycin, targeting IRF4 inhibition, was employed to investigate T cell proliferation, apoptosis, cytokine secretion, expression of T-cell dysfunction-associated molecules, effects of mitogen-activated protein kinase (MAPK) and mammalian target of rapamycin (mTOR) signaling pathways, and allograft survival in both in vitro and BALB/c to C57BL/6 mouse cardiac transplantation models. RESULTS: In vitro , blockade of IRF4 in T cells effectively inhibited T cell proliferation, increased apoptosis, and significantly upregulated the expression of programmed cell death protein 1 (PD-1), Helios, CD160, and cytotoxic T lymphocyte-associated antigen (CTLA-4), markers of T cell dysfunction. Furthermore, it suppressed the secretion of pro-inflammatory cytokines interferon (IFN)-γ and interleukin (IL)-17. Combining ultra-low-dose Trametinib (0.1 mg·kg -1 ·day -1 ) and Rapamycin (0.1 mg·kg -1 ·day -1 ) demonstrably extended graft survival, with 4 out of 5 mice exceeding 100 days post-transplantation. Moreover, analysis of grafts at day 7 confirmed sustained IFN regulatory factor 4 (IRF4) inhibition, enhanced PD-1 expression, and suppressed IFN-γ secretion, reinforcing the in vivo efficacy of this IRF4-targeting approach. The combination of Trametinib and Rapamycin synergistically inhibited the MAPK and mTOR signaling network, leading to a more pronounced suppression of IRF4 expression. CONCLUSIONS Targeting IRF4, a key regulator of T cell dysfunction, presents a promising avenue for inducing transplant immune tolerance. In this study, we demonstrate that a novel ultra-low-dose combination of Trametinib and Rapamycin synergistically suppresses the MAPK and mTOR signaling network, leading to profound IRF4 inhibition, promoting allograft acceptance, and offering a potential new therapeutic strategy for improved transplant outcomes. However, further research is necessary to elucidate the underlying pharmacological mechanisms and facilitate translation to clinical practice.
Animals ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Interferon Regulatory Factors/metabolism* ; Heart Transplantation/methods* ; T-Lymphocytes/immunology* ; Sirolimus/therapeutic use* ; Pyridones/therapeutic use* ; Graft Survival/drug effects* ; Pyrimidinones/therapeutic use* ; Cell Proliferation/drug effects* ; Apoptosis/drug effects* ; Male ; Signal Transduction/drug effects*

OBJECTIVE: To investigate the mechanism of human embryonic stem cell-derived mesenchymal stem cells (hESC-MSC) in alleviating brain injury after resuscitation in swine with cardiac arrest (CA). METHODS: Twenty-nine healthy male large white swine were randomly divided into Sham group (n = 9), cardiopulmonary resuscitation (CPR) group (n = 10) and hESC-MSC group (n = 10). The Sham group only completed animal preparation. In CPR group and hESC-MSC group, the swine model of CA-CPR was established by inducing ventricular fibrillation for 10 minutes with electrical stimulation and CPR for 6 minutes. At 5 minutes after successful resuscitation, hESC-MSC 2.5×10⁶/kg was injected via intravenous micropump within 1 hour in hESC-MSC group. Venous blood samples were collected before resuscitation and at 4, 8, 24, 48 and 72 hours of resuscitation. The levels of neuron specific enolase (NSE) and S100B protein (S100B) were detected by enzyme linked immunosorbent assay (ELISA). At 24, 48 and 72 hours of resuscitation, neurological deficit score (NDS) and cerebral performance category (CPC) were used to evaluate the neurological function of the animals. Three animals from each group were randomly selected and euthanized at 24, 48, and 72 hours of resuscitation, and the hippocampus tissues were quickly obtained. Immunofluorescence staining was used to detect the distribution of hESC-MSC in hippocampus. Immunohistochemical staining was used to detect the activation of astrocytes and microglia and the survival of neurons in the hippocampus. The degree of apoptosis was detected by TdT-mediated dUTP nick end labeling (TUNEL). RESULTS: The serum NSE and S100B levels of brain injury markers in CPR group and hESC-MSC group were significantly higher than those in Sham group at 24 hours of resuscitation, and then gradually increased. The levels of NSE and S100B in serum at each time of resuscitation in hESC-MSC group were significantly lower than those in CPR group [NSE (μg/L): 20.69±3.62 vs. 28.95±3.48 at 4 hours, 27.04±5.56 vs. 48.59±9.22 at 72 hours; S100B (μg/L): 2.29±0.39 vs. 3.60±0.73 at 4 hours, 2.38±0.15 vs. 3.92±0.50 at 72 hours, all P < 0.05]. In terms of neurological function, compared with the Sham group, the NDS score and CPC score in the CPR group and hESC-MSC group increased significantly at 24 hours of resuscitation, and then gradually decreased. The NDS and CPC scores of hESC-MSC group were significantly lower than those of CPR group at 24 hours of resuscitation (NDS: 111.67±20.21 vs. 170.00±21.79, CPC: 2.33±0.29 vs. 3.00±0.00, both P < 0.05). The expression of hESC-MSC positive markers CD73, CD90 and CD105 in the hippocampus of hESC-MSC group at 24, 48 and 72 hours of resuscitation was observed under fluorescence microscope, indicating that hESC-MSC could homing to the damaged hippocampus. In addition, compared with Sham group, the proportion of astrocytes, microglia and apoptotic index in hippocampus of CPR group were significantly increased, and the proportion of neurons was significantly decreased at 24, 48 and 72 hours of resuscitation. Compared with CPR group, the proportion of astrocytes, microglia and apoptotic index in hippocampus of hESC-MSC group decreased and the proportion of neurons increased significantly at 24 hours of resuscitation [proportion of astrocytes: (14.33±1.00)% vs. (30.78±2.69)%, proportion of microglia: (12.00±0.88)% vs. (27.89±5.68)%, apoptotic index: (12.89±3.86)% vs. (52.33±7.77)%, proportion of neurons: (39.44±3.72)% vs. (28.33±1.53)%, all P < 0.05]. CONCLUSIONS Application of hESC-MSC at the early stage of resuscitation can reduce the brain injury and neurological dysfunction after resuscitation in swine with CA. The mechanism may be related to the inhibition of immune cell activation, reduction of cell apoptosis and promotion of neuronal survival.
Animals ; Heart Arrest/therapy* ; Cardiopulmonary Resuscitation ; Swine ; Humans ; Male ; Human Embryonic Stem Cells/cytology* ; Mesenchymal Stem Cell Transplantation ; Mesenchymal Stem Cells/cytology* ; Phosphopyruvate Hydratase/blood* ; Brain Injuries/therapy* ; S100 Calcium Binding Protein beta Subunit ; Apoptosis ; Disease Models, Animal

The current organ allocation rules prioritize elderly and urgent patients on the lung transplantation (LT) waiting list. A steady increase in the threshold at which age is taken into consideration for LT has been observed. This retrospective cohort study recruited 166 lung transplant recipients aged ≽ 65 years between January 2016 and October 2020 in the largest LT center in China. In the cohort, subgroups of patients aged 65-70 years (111 recipients, group 65-70) and ≽ 70 years (55 recipients, group ≽ 70) were included. Group D restrictive lung disease was the main indication of a lung transplant in recipients over 65 years. A significantly higher percentage of coronary artery stenosis was observed in the group ≽ 70 (30.9% vs. 14.4% in group 65-70, P = 0.014). ECMO bridging to LT was performed in 5.4% (group 65-70) and 7.3% (group ≽ 70) of patients. Kaplan-Meier estimates showed that recipients with cardiac abnormalities had a significantly increased risk of mortality. After adjusting for potential confounders, cardiac abnormality was shown to be independently associated with the increased risk of post-LT mortality (HR 6.37, P = 0.0060). Our result showed that LT can be performed in candidates with an advanced age and can provide life-extending benefits.
Aged ; Humans ; East Asian People ; Heart Diseases/etiology* ; Lung Transplantation/adverse effects* ; Retrospective Studies

The number of patients with heart failure in China is large, and the proportion of patients with end-stage heart failure continues to increase. The clinical effect of guideline-directed medications therapy for end-stage heart failure is poor. Heart transplantation is the most effective treatment for end-stage heart failure. But it is faced with many limitations such as the shortage of donors. In recent years, the research and development of artificial heart in China has made great progress. Three devices have been approved by the National Medical Products Administration for marketing, and another one is undergoing pre-marketing clinical trial. Since 2017, more than 200 cases of ventricular assist device implantation have been carried out in more than 34 hospitals in China. Among them, 70 patients in Fuwai Hospital, Chinese Academy of Medical Sciences had a 2-year survival rate of 90%. The first patient has survived more than 5 years with the device. More efforts should be put into the training of standardized technical team and quality control. Further research should be carried out in the aspects of pulsatile blood flow pump, fully implanted cable-free device, and improved biomaterial with better blood compatibility.
Humans ; Heart-Assist Devices ; Heart Failure/surgery* ; Heart, Artificial ; Heart Transplantation ; Pulsatile Flow

Heart failure (HF),a chronic progressive disease,is a global health problem and the leading cause of deaths in the global population.The pathophysiological abnormalities of HF mainly include abnormal cardiac structure (myocardium and valves),disturbance of electrophysiological activities,and weakened myocardial contractility.In addition to drug therapy and heart transplantation,interventional therapies can be employed for advanced-stage HF,including transcatheter interventions and mechanical circulatory assist devices.This article introduces the devices used for advanced HF that have been marketed or certified as innovative or breakthrough devices around the world and summarizes the research status and prospects the trend in this field.As diversified combinations of HF devices are used for the treatment of advanced HF,considerations regarding individualized HF therapy,risk-benefit evaluation on device design,medical insurance payment,post-market supervision system,and protection of intellectual property rights of high-end technology are needed,which will boost the development of the technology and industry and benefit the patients.
Humans ; Heart-Assist Devices ; Heart Failure/therapy* ; Heart Transplantation ; Myocardium ; Chronic Disease

Humans ; Atrial Fibrillation/surgery* ; Recovery of Function ; Radiofrequency Ablation ; Heart ; Heart Transplantation ; Catheter Ablation ; Treatment Outcome

Humans ; Atrial Fibrillation/surgery* ; Recovery of Function ; Radiofrequency Ablation ; Heart ; Heart Transplantation ; Catheter Ablation ; Treatment Outcome

In this study, we aim to elucidate the clinical impact and long-term course of tricuspid regurgitation (TR), taking into account its dynamic nature, after biatrial orthotopic heart transplant (OHT). All consecutive adult patients undergoing biatrial OHT (1984-2017) with an available follow-up echocardiogram were included. Mixed-models were used to model the evolution of TR. The mixed-model was inserted into a Cox model in order to address the association of the dynamic TR with mortality. In total, 572 patients were included (median age: 50 years, males: 74.9%). Approximately 32% of patients had moderate-to-severe TR immediately after surgery. However, this declined to 11% on 5 years and 9% on 10 years after surgery, adjusted for survival bias. Pre-implant mechanical support was associated with less TR during follow-up, whereas concurrent LV dysfunction was significantly associated with more TR during follow-up. Survival at 1, 5, 10, 20 years was 97% ± 1%, 88% ± 1%, 66% ± 2% and 23% ± 2%, respectively. The presence of moderate-to-severe TR during follow-up was associated with higher mortality (HR: 1.07, 95% CI (1.02-1.12), p = 0.006). The course of TR was positively correlated with the course of creatinine (R = 0.45). TR during follow-up is significantly associated with higher mortality and worse renal function. Nevertheless, probability of TR is the highest immediately after OHT and decreases thereafter. Therefore, it may be reasonable to refrain from surgical intervention for TR during earlier phase after OHT.
Male ; Adult ; Humans ; Middle Aged ; Tricuspid Valve Insufficiency/diagnostic imaging* ; Heart Transplantation ; Echocardiography ; Ventricular Dysfunction, Left ; Retrospective Studies ; Treatment Outcome

Cardiac Rehabilitation ; Exercise Therapy ; Heart Failure/surgery* ; Heart Transplantation ; Humans

INTRODUCTION: The aims of this study were to establish weight change, incidence of non-alcoholic fatty liver disease (NAFLD) and cardiovascular risk factors (CvRF) in liver transplant recipients (LTRs). METHODS: Eighty-three patients whose mean (standard deviation [SD]) age was 55.6 (8.4) years (median follow-up 73 months) and who underwent their first liver transplantation (LT) at Singapore General Hospital between February 2006 and March 2017 were included in the study. Anthropometric, clinical and demographic data were collected retrospectively from patients' medical records. Diabetes mellitus (DM), hyperlipidaemia and hypertension were regarded as CvRF. RESULTS: Compared to baseline, mean (SD) body weight decreased significantly at 1 month post-LT (60.8kg [11.9] versus 64.3kg [13.7], CONCLUSION CvRF increased significantly post-LT, and NAFLD occurred in 25.3% of LTRs. Body weight dropped drastically within the first month post-LT, which then returned to baseline level just before the end of first year. This novel finding suggests that nutritional intervention needs to be tailored and individualised, based on events and time from transplant. Although long-term obesity is a significant problem, aggressive oral or enteral nutritional supplements take precedence in the early and immediate post-LT period, while interventions targeted at metabolic syndrome become necessary after the first year.
Cardiovascular Diseases/etiology* ; Heart Disease Risk Factors ; Humans ; Liver Transplantation ; Middle Aged ; Retrospective Studies ; Risk Factors ; Singapore/epidemiology*