Transplantation Model Research Articles

Preservation of Cardiac Xenografts in a Model of Infant Human Cardiac Transplantation.

There is no standard protocol for management of organ preservation for orthotopic, life-sustaining cardiac xenotransplantation, particularly for hearts from pediatric sized donors. Standard techniques and solutions successful in human allotransplantation are not viable. We theorized that a solution commonly used in reparative cardiac surgery in human children would suffice by exploiting the advantages inherent to xenotransplantation, namely the ability to reduce organ ischemic times by co-locating the donor and recipient. Orthotopic cardiac xenotransplantation was performed from genetically engineered pigs to size matched baboons. A dose of modified Del Nido cardioplegia initiated donor heart arrest and was followed by a second dose mixed with recipient blood prior to implant. Hemodynamics and cardiac function were tracked with a combination of invasive and non-invasive measures. Mean ischemic time and cardiopulmonary bypass times were 54.1 ± 14.6 and 84.1 ± 14 min respectively. The ejection fraction following chest closure was preserved at >50% for all animals. This finding persisted at 48hours. Mean inotropic score at 24 h post-implant was 9.7 ± 3. Del Nido cardioplegia solution when combined with short graft ischemic times demonstrates promising outcomes to avoid primary graft dysfunction for cardiac xenografts in a small animal model of life-sustaining orthotopic cardiac xenotransplantation. Ex vivo perfusion systems may be unnecessary for successful clinical implementation of this evolving technology.

Evaluating the cost, cost-effectiveness and survival of an eHealth-facilitated integrated care model for allogeneic stem cell transplantation: Results of the German SMILe randomized, controlled implementation science trial.

eHealth-facilitated integrated care models (eICMs) have proved effective in improving outcomes for chronically ill patients. However, evidence on cost-effectiveness of eICMs is scarce so far. Allogeneic stem cell transplantation (alloSCT) recipients' post-discharge treatment costs and mortality are greatly influenced by complications. Within the international, multicentric SMILe implementation science project, the eHealth-facilitated SMILe integrated care model (SMILe-ICM) was developed to support patients minimize complications' effects within the first year post-alloSCT. Using initial effectiveness findings from the first center that implemented the SMILe-ICM, this study provides a cost and cost-effectiveness evaluation considering one-year and long-term survival effects, post-discharge costs, and patient-related factors. A single-center hybrid effectiveness implementation randomized controlled trial was conducted at a German university hospital from 2/2020 to 8/2022. Eligible alloSCT patients were randomized to the SMILe-ICM or usual care, i.e., one pre-transplant educational nursing visit followed by a physician-led follow-up. The intervention group received usual care plus the SMILe-ICM's four intervention modules (i.e., monitoring of medical/symptom-related parameters, medication adherence, infection prevention, physical activity). All modules were delivered by Advanced Practice Nurses (APNs) in face-to-face visits, combined with continuous online support. Daily, patients entered seventeen medical and symptom-related parameters to the SMILe App, so that APNs could monitor for and investigate possible pre-complication signs. Healthcare utilization costs were assessed at eight time-points (d+30 post-alloSCT-d365) on fourteen self-reported cost indicators and validated against health records. To calculate costs, we applied German standardized unit costs. Cost- and cost-effectiveness were analyzed in five steps: 1.) Calculate total costs, including for the alloSCT inpatient stay and post-discharge follow-up. 2.) Determine life-years gained (survival) as a health benefit unit. 3.) Calculate overall and rehospitalization-free survival estimates. 4.) Calculate the intervention's long-term cost-effectiveness, including extended follow-up, rate of survival until day 1000, and restricted mean survival time. 5.) Contrast these long-term estimates to current post-discharge costs with comparable patient-related factors (age≥or<65, living alone, gender). Seventy-two patients participated (n=36/group). Total intergroup healthcare utilization and post-discharge costs differed, but non-significantly. Survival rates improved with the SMILe-ICM (88% vs. 80%) at least until day +1000. Rehospitalization-free survival showed improvement (38% vs. 30%); however, considering this sample size, both findings were nonsignificant. Cost-effectiveness analysis showed an overall post-discharge cost-effectiveness of 35,364.01€/patient and 6,742€/life year gained - a mean of 79.21 additional days of life for an intervention investment of 1.464€/patient in the first year post-alloSCT. One-year cost-effectiveness was highest for patients living alone. Younger age correlated with longer survival but higher costs. The SMILe-ICM appears to offer survival and rehospitalization benefits, particularly for vulnerable groups, e.g., patients living alone. Larger, adequately powered studies are needed to validate these findings.

Brain inflammation and cognitive decline induced by spinal cord injury can be reversed by spinal cord cell transplants.

Spinal cord injuries (SCIs) impact between 250,000 and 500,000 people worldwide annually, often resulting from road accidents or falls. These injuries frequently lead to lasting disabilities, with the severity depending on the injury's extent and location. Emerging research also links SCIs to cognitive impairments due to brain inflammation. From a treatment perspective, various approaches, including cell therapy, have been investigated. One common mechanism across cellular transplant models is the modulation of inflammation at the injury site, though it remains uncertain if these effects extend to the brain. To explore this, we induced SCI in wild-type mice and treated them with either olfactory ensheathing cells or mesenchymal stem cells. Our findings reveal that both cell types can reverse SCI-induced cognitive deficits, reduce brain inflammation, and increase hippocampal neuronal density. This study is the first, to our knowledge, to demonstrate that cells transplanted into the spinal cord can influence brain inflammation and mitigate injury-induced effects on brain functions. These results highlight the intricate relationship between the spinal cord and brain in both health and disease.

WWC proteins-mediated compensatory mechanism restricts schwannomatosis driven by NF2 loss of function.

NF2-related schwannomatosis, previously known as neurofibromatosis type 2, is a genetic disorder characterized by nerve tumors due to NF2 gene mutations. Mice with Nf2 deletion develop schwannomas slowly with low penetrance, hence inconvenient for preclinical studies. Here, we show that NF2, by recruiting E3 ubiquitin ligases β-TrCP1/2, promotes WWC1-3 ubiquitination and degradation. In NF2 mutated cells, WWC1-3 accumulation is a compensatory mechanism to prevent YAP/TAZ hyperactivation and rapid tumorigenesis. Accordingly, we generate a synthetic mouse model with complete penetrance and short latency by concurrently deleting Nf2 and Wwc1/2 in Schwann cells. This model closely resembles NF2-related schwannomatosis in patients, as confirmed by histological and single-cell transcriptome analysis. Moreover, a cell line from mouse schwannomas and a syngeneic tumor model in immune-competent mice are established. Furthermore, a screen using established models has identified candidate drugs that effectively suppress schwannoma progression. Hence, this work has developed rapid and transplantable models that will facilitate both basic and translational research on NF2-related schwannomatosis.

Nrf2/HO-1 Pathway Mediated Protective Effects of Hydrogen in a Model of Lung Transplantation Simulated by Rat Pulmonary Microvascular Endothelial Cells.

This study aimed to observe the mechanism of hydrogen (H2) in a lung transplantation model simulated by pulmonary microvascular endothelial cells (PMVECs), which were divided into 5 groups. The blank group was the normal PMVECs. During cold ischemia period, PMVECs in the control, O2, or H2 groups were aerated with no gas, O2, or 3% H2, and 3% H2 after transfected with a small interfering RNA targeting Nrf2 in the H2+si-Nrf2 group. Treatment with O2 and H2 decreased the oxidative stress injury, inflammation, cell apoptosis, and attenuated energy metabolism compared with the control group (P < 0.05). And the H2 group showed a better outcome with the increased protein expression of the Nrf2 and HO-1, which were conversed in the H2+si-Nrf2 group. In conclusion, H2 attenuated inflammation, oxidative stress injury, cell apoptosis, and maintained the balance between energy supply and demand in a rat PMVECs lung transplantation model via Nrf2/HO-1.

FPR1 affects acute rejection in kidney transplantation by regulating iron metabolism in neutrophils

BackgroundAcute rejection (AR) is one of the significant factors contributing to poor prognosis in patients following kidney transplantation. Neutrophils are the main cause of early host-induced tissue injury. This paper intends to investigate the possible mechanisms of neutrophil involvement in acute rejection in renal transplantation.MethodsSamples were analyzed for their relationship with immune cells using CIBERSORT. WGCNA was used to identify modules with high relevance to neutrophils and hub genes in the modules were extracted. The effect on neutrophil function after blocking formyl peptide receptor 1 (FPR1) was tested in vitro experiments. The effects of blocking FPR1 on neutrophil function as well as acute rejection were tested in vivo after constructing a mouse kidney transplant model.ResultsThe proportion of neutrophils was higher in the AR group than in the non-rejection group, and FPR1 was identified as an important gene in the regulation of acute rejection in kidney transplantation by neutrophils. At the cellular level, blocking FPR1 inhibited the activation of the ERK1/2 pathway, decreased ferrous ion content, affected the expression of iron metabolism-related proteins, and suppressed the formation of NETs. In the acute rejection model of renal transplantation, blockade of FPR1 decreased graft neutrophil infiltration and NETs content. Meanwhile, blocking FPR1 attenuated graft injury during acute rejection.ConclusionThis study found that FPR1 might be an important molecule involved in neutrophils during acute rejection of kidney transplantation, explored the relationship between kidney transplantation and neutrophils, and provided potential treatment methods for clinical practice.

Targeting TCMR-associated cytokine genes for drug screening identifies PPARγ agonists as novel immunomodulatory agents in transplantation

ObjectiveT cell-mediated rejection (TCMR) remains a significant challenge in organ transplantation. This study aimed to define a TCMR-associated cytokine gene set and identify drugs to prevent TCMR through drug repurposing.MethodsGene expression profiles from kidney, heart, and lung transplant biopsies were obtained from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) between TCMR and non-TCMR groups were identified, and their intersection with cytokine-related genes yielded an 11-gene TCMR-associated cytokine gene set (TCMR-Cs). To evaluate the effectiveness of this gene set, a diagnostic predictive model was constructed using Lasso regression and multivariate logistic regression, with validation in independent datasets. Connectivity Map (CMap) analysis was employed to screen drugs targeting TCMR-Cs. Experimental validation of the identified drug was performed in vitro using T cell activation and Th1 differentiation assays, and in vivo in a mouse skin transplant model with survival analysis.ResultsThe TCMR-Cs exhibited outstanding predictive performance for TCMR, achieving an AUC of 0.99 in the training cohorts and maintaining strong performance in the test cohorts. CMap analysis identified peroxisome proliferator-activated receptor gamma (PPARγ) agonists as potential therapeutic candidates. Experimental validation showed that the PPARγ agonist rosiglitazone significantly suppressed T cell activation and reduced Th1 differentiation in vitro without cytotoxic effects. The combination of rosiglitazone and rapamycin significantly prolonged graft survival.ConclusionsThis study defined a novel TCMR-associated cytokine gene set that effectively predicts TCMR and identified PPARγ agonists, which prevent TCMR and improve graft survival when combined with rapamycin.

Tannic acid-modified FK506-loaded nanoparticles targeting lymph nodes for acute heart transplant rejection treatment.

Significant efforts have been made to deliver immunosuppressants-loaded nanoparticles (NPs) to lymph nodes (LNs) to mitigate transplant rejection. However, conventional administration techniques encounter challenges in enhancing the retention of NPs in the LNs. Attributing the strong affinity of tannic acid (TA) molecules to the elastin of LN conduits, we developed a novel formulation of NPs encapsulating Tacrolimus (FK506), and subsequently modified with TA to produce TA-FNP with a final diameter of approximately 86.07 ± 2.78 nm. These particles could traverse the the intercellular gaps in the lymphatic endothelial cells layers, enter the paracortex through LN capsule-associated conduits, and releases FK506 to inhibit the activation and proliferation of allogeneic T cells. Our finding demonstrated that TA-FNP could accumulate in LNs, significantly increasing the local concentration of FK506 from 69.06 ± 21.96 ng/g to 1041.28 ± 343.59 ng/g compared to the free FK506 treatment group. Subsequently, the therapeutic efficacy of TA-FNP was assessed in heart transplantation model, where treatment with TA-FNP resulted in decreased T cells infiltration within the grafts, reduced rejection grades, and a significant extension of graft survival time. In contrast, FNP without TA showed relatively poor therapeutic outcomes. Consequently, this study reveals a promising strategy utilizing TA to enhance the prolonged retention of FK506 within LNs, underscoring its potential therapeutic application in preventing heart transplant rejection.

Biomechanically inspired composite hydrogel bioink enhances engineered cartilage formation

Current therapies for articular cartilage defects or degeneration (osteoarthritis) remain unsatisfactory. There are significant clinical demands for the development of more efficient approaches to enhance the repair or regeneration of articular cartilage lesions. In this study, a newly defined alginate-gelatin (A-G) composite bioink was synthesized using the carbodiimide chemistry crosslinking method. Then, the dual-crosslinking (DC) bioscaffolds containing both chemical and ionic networks were fabricated by 3D-bioprinting technique and Ca2+ treatment. The optimized networks formed in the DC bioscaffolds provided a desirable Young&amp;rsquo;s modulus and geometric constraints, which were superior to that of the single-crosslinking (SC) control group to mimic the mechanical properties of the pericellular matrix (PCM) of native articular cartilage. Chondrocytes exhibited above 95% viability and higher proliferation rate in the 3D printed A-G-DC bioscaffolds than in the alginate-only group after 7 days in vitro culture. Chondrogenic differentiation in vitro was improved in the A-G-DC bioscaffolds than that of the alginate-only group, indexed by upregulation of chondrogenic marker gene expression including Sox9, Col2a1, Comp and Aggrecan. In the subcutaneous transplantation model and osteochondral defect model in mice with severe combined immunodeficiency (SCID), the A-G-DC bioscaffolds exhibited enhanced chondrogenesis and repair capacity than the alginate-only or none-implant control group, characterized by the increased expression of SOX9 and collagen type II (Col II) and higher ICRS II scores, respectively. These findings demonstrated that the biomechanically inspired A-G composite bioink and the 3D-printed A-G-DC bioscaffolds possess excellent cell biocompatibility, satisfactory biomechanical properties and chondrogenesis promotion capacity, which have the potential to be applied to enhance cartilage regeneration for patients with articular cartilage lesions.

UW supplementation with AP39 improves liver viability following static cold storage

Static cold storage of donor livers at 4 °C incompletely arrests metabolism, ultimately leading to decreases in ATP levels, oxidative stress, cell death, and organ failure. Hydrogen Sulfide (H2S) is an endogenously produced gas, previously demonstrated to reduce oxidative stress, reduce ATP depletion, and protect from ischemia and reperfusion injury. H2S is difficult to administer due to its rapid release curve, resulting in cellular death at high concentrations. AP39, a mitochondrially targeted, slow-release H2S donor, has been shown to reduce ischemia-reperfusion injury in hearts and kidneys. Thus, we investigated whether the addition of AP39 during 3-day static cold storage can improve liver graft viability. At the end of storage, livers underwent six hours of acellular normothermic machine perfusion, a model of transplantation. During simulated transplantation, livers stored with AP39 showed reduced resistance, reduced cellular damage (ALT and AST), and reduced apoptosis. Additionally, bile production and glucose, as well as energy charge were improved by the addition of AP39. These results indicate that AP39 supplementation improves liver viability during static cold storage.

Bioinformatics analysis of ferroptosis-related hub genes and immunoinfiltration in myocardial ischemia/reperfusion following heart transplantation

BackgroundIschemia/reperfusion (I/R) is an inevitable pathophysiological process during heart transplantation, and ferroptosis is an important pathogenic mechanism. Unlike other modes of cell death, ferroptosis depends on the accumulation of iron within the cell and the oxidative degradation of polyunsaturated fatty acids. Dysregulation of this pathway has been linked to the progression of multiple pathological conditions, making it an attractive target for therapeutic intervention. Therefore, this study aims to explore the effect of ferroptosis on I/R during heart transplantation.MethodsGEO2R was applied to identify differentially expressed genes (DEGs) obtained from GSE50884 data, which was involved in I/R and heart transplantation. And ferroptosis-related DEGs (FRDEGs) were screened by venn diagram with ferroptosis-related genes downloaded from FerDb database. FRDEGs was enriched and analyzed by GO and KEGG, and hub genes related to ferroptosis were screened by Cytoscape software and database STRING. Additionally, considering the relationship between ferroptosis and immunity, CIBERSORTx was to analyze the infiltration of 22 kinds of immune cells in I/R during heart transplantation, and the correlation between each immune cell and the expression of FRDEGs was also discussed. Finally, the mouse model of heart transplantation with I/R was constructed, and the hub genes was verified by RT-qPCR and western blot.Results12 FRDEGs were identified out of 327 DEGs in GSE50844, which were mainly involved in ferroptosis and other pathways. Three hub genes (SLC7A11, PSAT1, ASNS) were obtained by the degree algorithm of cytohubba plug-in. Immunoinfiltration analysis showed that 16 of 22 immune cells changed, and the immune score of heart transplantation with I/R was higher than that without I/R. In addition, hub genes exhibited significant correlation with Eosinophils, NK cells resting, Dendritic cells resting, NK cells activated and T cells CD4 memory activated. We verified the expression of SLC7A11, PSAT1 and ASNS was higher than that in normal tissues using RT-qPCR and western blot in mouse models of heart transplantation with I/R, companied by ferroptosis aggravated is involved.ConclusionsIn short, ferroptosis is involved in I/R injury during heart transplantation, which is related to immune cell infiltration. Three hub genes (SLC7A11, PSAT1 and ASNS) identified in this study provide therapeutic targets for ameliorating I/R injury in heart transplantation.

Investigating resistance to 5-Azacytidine and Venetoclax in PDX models of MDS/AML.

Progressing myelodysplastic syndrome (MDS) into acute myeloid leukemia (AML) is an indication for hypomethylating therapy (HMA, 5-Azacytidine (AZA)) and a BCL2 inhibitor (Venetoclax, VEN) for intensive chemotherapy ineligible patients. Mouse models that engraft primary AML samples may further advance VEN + AZA resistance research. We generated a set of transplantable murine PDX models from MDS/AML patients who developed resistance to VEN + AZA and compared the differences in hematopoiesis of the PDX models with primary bone marrow samples at the genetic level. PDX were created in NSGS mice via intraosseal injection of luciferase-encoding Lentivirus-infected MDS/AML primary cells from patient bone marrow. We validated the resistance of PDX-leukemia to VEN and AZA and further tested candidate agents that inhibit the growth of VEN/AZA-resistant AML. Transplantable PDX models for MDS/AML arise with 31 % frequency. The lower frequency of transplantable PDX models is not related to peritransplant lethality of the graft, but rather to the loss of the ability of short-term proliferation of leukemic progenitors after 10 weeks of engraftment. There exist subtle genetic and cytological changes between primary and PDX-AML samples however, the PDX models retain therapy resistance observed in patients. Based on in vitro testing and in vivo validation in PDX models, Panobinostat and Dinaciclib are very promising candidate agents that overcome dual VEN + AZA resistance.

Selenoprotein-Mediated Redox Regulation Shapes the Cell Fate of HSCs and Mature Lineages.

The maintenance of cellular redox balance is crucial for cell survival and homeostasis and is disrupted with aging. Selenoproteins, comprising essential antioxidant enzymes, raise intriguing questions about their involvement in hematopoietic aging and potential reversibility. Motivated by our observation of mRNA downregulation of key antioxidant selenoproteins in aged human hematopoietic stem cells (HSCs) and previous findings of increased lipid peroxidation in aged hematopoiesis, we employed tRNASec gene (Trsp) knockout (KO) mouse model to simulate disrupted selenoprotein synthesis. This revealed insights into the protective roles of selenoproteins in preserving HSC stemness and B-lineage maturation, despite negligible effects on myeloid cells. Notably, Trsp KO exhibited B lymphocytopenia and reduced HSCs' self-renewal capacity, recapitulating certain aspects of aged phenotypes, along with the upregulation of aging-related genes in both HSCs and pre-B cells. While Trsp KO activated an antioxidant response transcription factor NRF2, we delineated a lineage-dependent phenotype driven by lipid peroxidation, which was exacerbated with aging yet ameliorated by ferroptosis inhibitors such as vitamin E. Interestingly, the myeloid genes were ectopically expressed in pre-B cells of Trsp KO mice, and KO pro-B/pre-B cells displayed differentiation potential toward functional CD11b+ fraction in the transplant model, suggesting that disrupted selenoprotein synthesis induces the potential of B-to-myeloid switch. Given the similarities between the KO model and aged wild-type mice, including ferroptosis vulnerability, impaired HSC self-renewal and B-lineage maturation, and characteristic lineage switch, our findings underscore the critical role of selenoprotein-mediated redox regulation in maintaining balanced hematopoiesis and suggest the preventive potential of selenoproteins against aging-related alterations.

Relevance of the GH-VEGFB/VEGFA axis in liver grafts from brain-dead donors with alcohol-associated liver disease.

Grafts with alcohol-associated liver disease (ALD) subjected to prolonged cold ischaemia from donors after brain death (DBD) are typically unsuitable for transplantation. Here, we investigated the role of growth hormone (GH) in livers with ALD from DBDs and its relationship with vascular endothelial growth factor A (VEGFA) and VEGFB. Livers from rats fed ethanol for 6weeks and with brain death (BD) were cold stored for 24h and subjected to ex vivo reperfusion. Hepatic damage and proliferative and inflammatory parameters were analysed after BD, before graft retrieval, and after reperfusion. Survival was monitored using an in vivo transplantation model. In DBDs, the administration of GH, which increased the levels in the intestine but not in the liver, induced the generation of both VEGFA and VEGFB in the intestine and protected against hepatic damage caused by BD before retrieving liver grafts from donors. However, VEGFA was the only factor that protected against damage after cold ischemia and reperfusion, which also increased the survival of the recipients. In conclusion, the signalling pathway and beneficial properties of the GH-VEGFA/VEGFB pathway, in which the intestine-liver axis plays a key role, were disrupted when grafts with ALD from DBDs were retrieved from donors and subjected to cold ischemia and reperfusion.

Differential Expression and Distribution of Slco4a1 and Slco1b2 in an Internal Environment Disorder-induced Hepatocellular Carcinoma Mouse Model.

This study aims to enhance the understanding of underlying mechanisms and potential therapies of the solute carrier organic anion (SLCO) transporter family in internal environment disorder (IED)-induced hepatocellular carcinoma (HCC). This could lead to new therapeutic strategies and offer new directions for the creation of new patents for HCC treatment products. The orthotopic transplantation (OT), IED and IED-based OT (IED-OT) mouse models were established. Expression patterns of Slco4a1 and Slco1b2 were determined using reverse transcriptionquantitative polymerase chain reaction (RT-qPCR), western blotting (WB) and immunohistochemistry (IHC) in various tissues, including lung, stomach, liver, spleen, kidney, colon, small intestine, HCC tissues and adjacent non-cancerous tissues. Animals exhibited symptoms, including weight loss, lethargy, chills, dyspnea, altered hair texture, and gastrointestinal disturbances, confirming the successful establishment of the IED model. The analysis demonstrated differential expression and tissue-specific distribution of Slco4a1 and Slco1b2, which are associated with IED-induced changes. These alterations potentially disrupt organ transport functions, thereby promoting the development of HCC. Additionally, they suggest a role in rebalancing the tumor microenvironment and mitigating damage resulting from abnormal substance accumulation. Changes in SLCO expression and distribution induced by IED may play pivotal roles in the development of HCC. These findings contribute insights that could inform novel therapeutic strategies against HCC.

Low regulatory T-cells frequency is associated with graft rejection after small bowel transplantation: Clinical and experimental evidence.

Intestinal transplantation (ITx) represents the only curative option for patients with irreversible intestinal failure. Nevertheless, its rejection rate surpasses that of other solid organ transplants due to the heightened immunological load of the gut. Regulatory T-cells (Tregs) are key players in the induction and maintenance of peripheral tolerance, suggesting their potential involvement in modulating host vs. graft responses after ITx. Thus, we investigated the association of Tregs with allograft outcomes in pediatric patients and in an experimental model of small bowel transplantation. Treg frequency in human samples was analyzed by Flow cytometry (CD4+CD25highCD127-, blood samples) and immunohistochemistry (FoxP3, graft samples). Experimental allogenic-heterotopic small bowel transplantation was performed in rats and animals divided into 3 groups: non-immunosuppressant treatment, rapamycin (2 mg/kg), and tacrolimus (0.6 mg/kg) treatment. Acute cellular rejection (ACR) was diagnosed based on clinical and histological findings, graft gene expression of pro- and anti-inflammatory mediators assessed by RT-qPCR, serum IL-6 and IL-10 levels by Luminex, and Treg frequency analyzed by flow cytometry (CD4+CD25highFoxP3+). Blood samples from patients undergoing ACR exhibited a significant reduction in the Treg number compared to those with normo-functional grafts. Similarly, a diminished number of FoxP3+ cells was observed in mucosa samples with ACR. In the experimental model, rapamycin-treated animals displayed clinical and histological findings resembling those not receiving immunosuppression treatment. Notably, ACR correlated with a high CD8/CD4 ratio, loss of T-cell chimerism, mRNA upregulation of pro-inflammatory genes and diminished graft Treg frequency. In contrast, tacrolimus treatment prevented ACR and facilitate blood and graft Treg expansion. Remarkably, recipients who achieved Treg expansion within the graft remained free of ACR even after discontinuation of the immunosuppressant treatment and this phenomenon was associated with increased levels of serum IL-10. Our clinical and experimental findings underscore the association between Treg frequency and graft rejection after ITx, advocating for strategies that promote their expansion within the gut mucosa to enhance long-term outcomes.

Impact of Hypothermic Perfusion on Immune Responses and Sterile Inflammation in a Preclinical Model of Pancreatic Transplantation.

In organ transplantation, cold ischemia is associated with sterile inflammation that subsequently conditions adaptive immunity directed against the grafts during revascularization. This inflammation is responsible for venous thrombosis, which is the main postoperative complication affecting graft function. Our aim was to investigate the modulation of immune responses and endothelial function of pancreatic grafts during cold ischemia using different preservation modalities. According to a preclinical porcine model of controlled donation after circulatory death, pancreatic grafts were preserved under hypothermic conditions for 24 h according to 4 modalities: static cold storage, hypothermic machine perfusion, hypothermic oxygenated perfusion at 21%, and 100%. Biopsies of the head and tail of the pancreas were performed during preservation. The first step involved a broad screening of the gene expression profile (84 genes) during preservation on a limited number of grafts. In the second step, a confirmation test was performed in all 4 groups. Vascular endothelial growth factor gene expression showed a decrease during preservation in the hypothermic oxygenated perfusion 21% and 100% groups compared with the static cold storage group. In contrast, thrombomodulin gene expression showed an increase during preservation in the hypothermic oxygenated perfusion 21% and 100% groups compared with the static cold storage and hypothermic machine perfusion groups. We demonstrated that compared with static cold storage, hypothermic oxygenated perfusion is an effective modality for modulating endothelial function by increasing thrombomodulin expression and decreasing ischemia and vascular endothelial growth factor expression.

Microspheres of stem cells from human exfoliated deciduous teeth exhibit superior pulp regeneration capacity

ObjectivesEngineering spheroids to create three-dimensional (3D) cell cultures has gained increasing attention in recent years due to their potential advantages over traditional two-dimensional (2D) tissue culture methods. Stem cells derived from human exfoliated deciduous teeth (SHEDs) demonstrate significant potential for pulpal regeneration applications. Nevertheless, the feasibility of microsphere formation of SHEDs and its impact on pulpal regeneration remain unclear. MethodsIn this study, SHEDs were isolated, identified, and cultured in ultra-low attachment six-well plates to produce SHED microspheres. The biological properties of SHED microspheres were compared to those of traditional 2D culture using live-dead staining, Alizarin red staining, Oil-red O staining, scratch experiments, Immunofluorescence, Transmission electron microscopy scan, Western blotting, RNA sequencing, and a nude mice subcutaneous transplantation model. ResultsWe found SHED cells can form microspheres with a dense internal structure. SHED microspheres exhibited notable advantages over SHED cells in terms of biological properties, maintaining cell activity and enhancing cell differentiation, migration, and stemness in vitro. RNA-seq revealed that the SHED microspheres potentially influenced cell development, regulation of neurogenesis, skeletal system development, tissue morphogenesis singling pathway. In vivo, SHED microspheres promoted the generation of pulp tissue in dental pulp compared to traditional 2D culture. ConclusionsMicrosphereization of SHED through 3D cell culture enhances its pulp regeneration capacity, presenting a novel strategy for dental pulp regeneration and the clinical treatment of dental pulp diseases.

Aptamer-modified melittin micelles efficiently inhibit osteosarcoma deterioration by inducing immunogenic cell death.

Osteosarcoma (OS) is the most common primary bone malignancy characterized by deposition of an immature osteoid matrix. OS treatment has proven challenging because of the high risk of metastatic progression and recurrence after chemotherapy. Melittin (MLT) is recognized as a potential antitumor candidate to overcome chemotherapy resistance and provoke superior immunostimulatory effects. However, the application of MLT to OS is hampered by severe toxic side effects and a lack of tumor-targeting ability. Herein, a self-assembled nanopolymer named LC09-MLT@F127 was developed by binding MLT with F127 micelles and then modifying an aptamer (LC09) for targeted drug delivery during OS treatment. LC09-MLT@F127 exhibited significant OS-targeting ability in vitro and in vivo owing to the aptamer LC09 decoration. Moreover, LC09-MLT@F127 significantly reduced the hemolytic toxicity of MLT while maintaining its tumor-killing ability. In an orthotopic transplantation model of OS, LC09-MLT@F127 induced immunogenic cell death and facilitated the maturation of dendritic cells (DCs), thereby resulting in the activation of tumor-specific immune responses and the inhibition of OS deterioration. Taken together, these finding suggest that LC09-MLT@F127 may be an encouraging MLT-based immunotherapy option for OS.

A Gift of Life during Life: Example of Iraqi Model for Renal Transplantation

A Gift of Life during Life: Example of Iraqi Model for Renal Transplantation