Mechanism Exploration on the Immunoregulation of Allogeneic Heart Transplantation Rejection in Rats With Exosome miRNA and Proteins From Overexpressed IDO1 BMSCs.

Immunoregulation and indoleamine 2,3-dioxygenase 1 (IDO1) play pivotal roles in the rejection of allogeneic organ transplantation. This study aims to elucidate the immune-related functional mechanisms of exosomes (Exos) derived from bone marrow-derived mesenchymal stem cells (BMSCs) overexpressing IDO1 in the context of allogeneic heart transplantation (HTx) rejection. A rat model of allogeneic HTx was established. Exos were extracted after transfection with oe-IDO1 and oe-NC from rat BMSCs. Exos were administered via the caudal vein for treatment. The survival of rats was analyzed, and reverse transcription qualitative PCR (RT-qPCR) and immunohistochemistry (IHC) were employed to detect the expression of related genes. Histopathological examination was conducted using hematoxylin and eosin (HE) staining, and flow cytometry was utilized to analyze T-cell apoptosis. Proteomics and RNA-seq analyses were performed on Exos. The data were subjected to functional enrichment analysis using the R language. A protein interaction network was constructed using the STRING database, and miRWalk, TargetScan, and miRDB databases predicted the target genes, differentially expressed miRNAs, and transcription factors (TFs). Exos from BMSCs overexpressing IDO1 prolonged the survival time of rats undergoing allogeneic HTx. These Exos reduced inflammatory cell infiltration, mitigated myocardial damage, induced CD4 T-cell apoptosis, and alleviated transplantation rejection. The correlation between Exos from BMSCs overexpressing IDO1 and immune regulation was profound. Notably, 13 immune-related differential proteins (Anxa1, Anxa2, C3, Ctsb, Hp, Il1rap, Ntn1, Ptx3, Thbs1, Hspa1b, Vegfc, Dcn, and Ptpn11) and 10 significantly different miRNAs were identified. Finally, six key immune proteins related to IDO1 were identified through common enrichment pathways, including Thbs1, Dcn, Ptpn11, Hspa1b, Il1rap, and Vegfc. Thirteen TFs of IDO1-related key miRNAs were obtained, and a TF-miRNA-mRNA-proteins regulatory network was constructed. Exosome miRNA derived from BMSCs overexpressing IDO1 may influence T-cell activation and regulate HTx rejection by interacting with mRNA.

A Novel Piecewise Cubic Hermite Interpolating Polynomial-Enhanced Convolutional Gated Recurrent Method under Multiple Sensor Feature Fusion for Tool Wear Prediction.

The monitoring of the lifetime of cutting tools often faces problems such as life data loss, drift, and distortion. The prediction of the lifetime in this situation is greatly compromised with respect to the accuracy. The recent rise of deep learning, such as Gated Recurrent Unit Units (GRUs), Hidden Markov Models (HMMs), Convolutional Neural Networks (CNNs), Recurrent Neural Networks (RNNs), Attention networks, and Transformers, has dramatically improved the data problems in tool lifetime prediction, substantially enhancing the accuracy of tool wear prediction. In this paper, we introduce a novel approach known as PCHIP-Enhanced ConvGRU (PECG), which leverages multiple-feature fusion for tool wear prediction. When compared to traditional models such as CNNs, the CNN Block, and GRUs, our method consistently outperformed them across all key performance metrics, with a primary focus on the accuracy. PECG addresses the challenge of missing tool wear measurement data in relation to sensor data. By employing PCHIP interpolation to fill in the gaps in the wear values, we have developed a model that combines the strengths of both CNNs and GRUs with data augmentation. The experimental results demonstrate that our proposed method achieved an exceptional relative accuracy of 0.8522, while also exhibiting a Pearson's Correlation Coefficient (PCC) exceeding 0.95. This innovative approach not only predicts tool wear with remarkable precision, but also offers enhanced stability.

Hyperleukocytic Acute Leukemia Circulating Exosomes Regulate HSCs and BM-MSCs.

Hyperleukocytic acute leukemia (HLAL) circulating exosomes are delivered to hematopoietic stem cells (HSCs) and bone marrow mesenchymal stem cells (BM-MSCs), thereby inhibiting the normal hematopoietic process. In this paper, we have evaluated and explored the effects of miR-125b, which is carried by HLAL-derived exosomes, on the hematopoietic function of HSCs and BM-MSCs. For this purpose, we have isolated exosomes from the peripheral blood of HLAL patients and healthy volunteers. Then, we measured the level of miR-125b in exosomes cocultured exosomes with HSCs and BM-MSCs. Moreover, we have used miR-125b inhibitors/mimic for intervention and then measured miR-125b expression and colony forming unit (CFU). Apart from it, HSC and BM-MSC hematopoietic-related factors α-globulin, γ-globulin, CSF2, CRTX4 and CXCL12, SCF, IGF1, and DKK1 expression were measured. Evaluation of the miR-125b and BAK1 targeting relationship, level of miR-125b, and expression of hematopoietic-related genes was performed after patients are treated with miR-125b mimic and si-BAK1. We have observed that miR-125b was upregulated in HLAL-derived exosomes. After HLAL-exosome acts on HSCs, the level of miR-125b is upregulated, reducing CFU and affecting the expression of α-globulin, γ-globulin, CSF2, and CRCX4. For BM-MSCs, after the action of HLAL-exo, the level of miR-125b is upregulated and affected the expression of CXCL12, SCF, IGF1, and DKK1. Exosomes derived from HLAL carry miR-125b to target and regulate BAK1. Further study confirmed that miR-125b and BAK1mimic reduced the expression of miR-125b and reversed the effect of miR-125b mimic on hematopoietic-related genes. These results demonstrated that HLAL-derived exosomes carrying miR-125b inhibit the hematopoietic differentiation of HSC and hematopoietic support function of BM-MSC through BAK1.

Indoleamine 2,3-dioxgenase-transfected mesenchymal stem cells suppress heart allograft rejection by increasing the production and activity of dendritic cells and regulatory T cells.

Expression of indoleamine 2,3-dioxygenase (IDO) in mesenchymal stem cells (MSC) is thought to contribute to MSC-mediated immunosuppression. A lentiviral-based transgenic system was used to generate bone marrow stem cells (BMSC) which stably expressed IDO (IDO-BMSCs). Coculture of IDO-BMSCs with dendritic cells (DC) or T cells was used to evaluate the immunomodulatory effect of IDO-BMSCs. A heterotopic heart transplant model in rats was used to evaluate allograft rejection after IDO-BMSC treatment. Mechanisms of IDO-BMSC-mediated immunosuppression were investigated by evaluating levels of proinflammatory and anti-inflammatory cytokines, and production of Tregs. A significant decrease in DC marker-positive cells and a significant increase in Tregs were observed in IDO-BMSC cocultured. Treatment of transplanted rats with IDO-BMSCs was associated with significantly prolonged graft survival. Compared with the control groups, transplanted animals treated with IDO-BMSCs had a (1) significantly higher ejection fraction and fractional shortening, (2) significantly lower expression of CD86, CD80, and MHCII, and significantly higher expression in CD274, and Tregs, and (3) significantly higher levels of interleukin-10 (IL-10), transforming growth factor beta-1 (TGF-ß1), TGF-ß2, and TGF-ß3, and significantly lower levels of IL-2 and interferon gamma. Our results expand our understanding of the molecular mechanisms underlying suppression of heart allograft rejection via IDO-expressing BMSCs.

Gata-4-overexpressed bone marrow mesenchymal stem cell secreted exosomes promote bone marrow mesenchymal stem cell differentiation into cardiomyocyte-like cells / 中国组织工程研究

BACKGROUND: Preliminary study has shown that overexpression of GATA-4-overexpressing bone marrow mesenchymal stem cell (BMSCs) exosomes (BMSCsGATA-4-exosome) can promote BMSCs differentiate into cardiomyocytes, indicating it can repair myocardial infarction. Additionally, high expression of miRNA-673-5p is observed in miRNA-673-5p BMSCsGATA-4-exosome and focal myocardium of myocardial infarction, which involve in cell differentiation, suggesting that miRNA-673-5p may be a key molecular of BMSCsGATA-4-exosome for repairing myocardial infarction. OBJECTIVE: To investigate the molecular regulatory network of BMSCsGATA-4-exosomes that promotes BMSCs differentiation into cardiomyocyte-like cells. METHODS: miR-673-5p-mimic was added to the BMSCs culture system as an experimental group (BMSCsmiR-330-3p-mimic ). BMSCsGATA-4, BMSCsGATA-4-empty vector, BMSCs and BMSCsGATA-4-miR-673-5p-inhibitor groups were set as confounding factor control groups. The exosomes and myocardial cells secreted by each group were co-cultured for 24 hours. The expression levels of myocardium specific molecules α-actin, Desmin, cTnT and Cx43 were detected by immunofluorescence and RT-PCR. The expression levels of the corresponding miRNA-673-5p target genes TSC-1, ERK1/2 and Mef2c were detected through western blot assay based on the prediction results of the microRNA target gene. RESULTS AND CONCLUSION: The BMSCsmiR-673-5p-mimic-exosome+BMSCs culture group had the highest α-actin, Desmin, cTnT and Cx43 levels (P < 0.05), and the lowest TSC-1 expression (P < 0.05). In summary, BMSCsGATA-4-exosome inhibits the expression of TSC-1 via miRNA-673-5p to promote BMSCs differentiation into cardiomyocyte-like cells.

Bone marrow mesenchymal stem cells overexpressing GATA-4 improve cardiac function following myocardial infarction.

INTRODUCTION: The present study aimed to examine whether GATA-4 overexpressing bone marrow mesenchymal stem cells can improve cardiac function in a murine myocardial infarction model compared with bone marrow mesenchymal stem cells alone. METHODS: A lentiviral-based transgenic system was used to generate bone mesenchymal stem cells which stably expressed GATA-4 (GATA-4-bone marrow mesenchymal stem cells). Apoptosis and the myogenic phenotype of the bone marrow mesenchymal stem cells were measured using Western blot and immunofluorescence assays co-cultured with cardiomyocytes. Cardiac function, bone marrow mesenchymal stem cell homing, cardiac cell apoptosis, and vessel number following transplantation were assessed, as well as the expression of c-Kit. RESULTS: In GATA-4-bone marrow mesenchymal stem cells-cardiomyocyte co-cultures, expression of myocardial-specific antigens, cTnT, connexin-43, desmin, and α-actin was increased compared with bone marrow mesenchymal stem cells alone. Caspase 8 and cytochrome C expression was lower, and the apoptotic rate was significantly lower in GATA-4 bone marrow mesenchymal stem cells. Cardiac function following myocardial infarction was also increased in the GATA-4 bone marrow mesenchymal stem cell group as demonstrated by enhanced ejection fraction and left ventricular fractional shortening. Analysis of the cardiac tissue revealed that the GATA-4 bone marrow mesenchymal stem cell group had a greater number of DiR-positive cells suggestive of increased homing and/or survival. Transplantation with GATA-4-bone marrow mesenchymal stem cells significantly increased the number of blood vessels, decreased the proportion of apoptotic cells, and increased the mean number of cardiac c-kit-positive cells. CONCLUSION: GATA-4 overexpression in bone marrow mesenchymal stem cells exerts anti-apoptotic effects by targeting cytochrome C and Fas pathways, promotes the aggregation of bone marrow mesenchymal stem cells in cardiac tissue, facilitates angiogenesis, and effectively mobilizes c-kit-positive cells following myocardial infarction, leading to the improvement of cardiac function after MI.

Exosomes Derived from IDO1-Overexpressing Rat Bone Marrow Mesenchymal Stem Cells Promote Immunotolerance of Cardiac Allografts.

BACKGROUND: The immunosuppressive activity of mesenchymal stem cells (MSCs) has been exploited to induce tolerance after organ transplantation. The indoleamine 2,3-dioxygenase (IDO) may have beneficial effects in the immunoregulatory properties of MSCs. It was recently revealed that exosomes derived from MSCs play important roles in mediating the biological functions of MSCs. This study aimed to explore the roles of exosomes derived from MSCs in the induction of immune tolerance. METHODS: Dendritic cells (DCs) and T-cells were cultured with exosomes derived from rat bone marrow MSCs (BMSCs) overexpressing IDO1 or controls. For the in-vivo study, rats received heart transplants and were treated with exosomes from IDO-BMSCs and heart function was evaluated. Flow cytometry was used to detect expression of cell surface markers. Cytokine levels were detected in culture supernatants or serum samples. Protein and microRNA expressions in exosomes were investigated by chips. RESULTS: Exosomes from IDO-BMSCs cultured with DCs and T-cells (1) downregulated CD40, CD86, CD80, MHC-II, CD45RA, CD45RA+CD45RB, OX62, and upregulated CD274 expression, (2) increased the number of regulatory T-cells (Tregs) and decreased the number of CD8+ T-cells, and (3) decreased the levels of pro-inflammatory cytokines, but increased the levels of anti-inflammatory cytokines compared with the other groups. Transplanted rats, which were injected with exosomes from IDO-BMSCs, had reduced allograft-targeting immune responses and improved cardiac allograft function. Exosomes secreted by IDO-BMSCs exhibited significant upregulations of the immunoregulatory protein FHL-1, miR-540-3p, and a downregulation of miR-338-5p. CONCLUSION: Exosomes derived from IDO-BMSCs can be used to promote immunotolerance and prolong the survival of cardiac allografts.

Surgical Repair of Complex Aortopulmonary Window: A Case Study.

Aortopulmonary septal defect, also known as the aortopulmonary window, is a rare congenital macrovascular malformation. This case involves a 9-year-old boy with aortopulmonary septal defect (type I combined with type IV). Before surgery, milrinone and alprostadil were used to counteract high lung pressure. Surgery was performed under cardiopulmonary bypass, following which the pulmonary pressure decreased. The aorta was cut, and the right pulmonary artery opening was connected with the main pulmonary artery septal defect using polyester patch. An internal tunnel was made, and the deformity correction was completed. The child exhibited normal postoperative recovery with no discomfort. A complex aortopulmonary window is a rare condition that can be treated successfully with appropriate preoperative and surgical management.

Surgical repair of complex aortopulmonary window: a case study

Abstract Aortopulmonary septal defect, also known as the aortopulmonary window, is a rare congenital macrovascular malformation. This case involves a 9-year-old boy with aortopulmonary septal defect (type I combined with type IV). Before surgery, milrinone and alprostadil were used to counteract high lung pressure. Surgery was performed under cardiopulmonary bypass, following which the pulmonary pressure decreased. The aorta was cut, and the right pulmonary artery opening was connected with the main pulmonary artery septal defect using polyester patch. An internal tunnel was made, and the deformity correction was completed. The child exhibited normal postoperative recovery with no discomfort. A complex aortopulmonary window is a rare condition that can be treated successfully with appropriate preoperative and surgical management.

GATA-4-expressing mouse bone marrow mesenchymal stem cells improve cardiac function after myocardial infarction via secreted exosomes.

This study aimed to investigate whether exosomes secreted by mouse GATA-4-expressing bone marrow mesenchymal stem cells (BMSCs) could induce BMSC differentiation into myocyte precursors, decrease cardiomyocyte apoptosis, and improve cardiac function following myocardial infarction (MI). BMSCs were transduced with a lentivirus carrying a doxycycline (DOX)-inducible GATA-4 or control lentivirus, and secreted exosomes from these BMSCs were collected and co-cultured with BMSCs or cardiomyocytes under hypoxic and serum free conditions. Furthermore, exosomes were injected into mice 48 h after MI. Cardiac function was evaluated by echocardiography at 48, 72, and 96 h after exosome treatment. Quantitative PCR showed that co-culture of BMSCs with GATA-4-BMSC exosomes increased cardiomyocyte-related marker expression. Co-culture of GATA-4-BMSC exosomes with cardiomyocytes in anoxic conditions decreased apoptosis as detected by flow cytometry. Injection of GATA-4-BMSC exosomes in mice 48 h after MI increased cardiac function over the next 96 h; increased cardiac blood vessel density and number of c-kit-positive cells and decreased apoptotic cardiomyocyte cells were also observed. Differential expression of candidate differentiation- and apoptosis-related miRNAs and proteins that may mediate these effects was also identified. Exosomes isolated from GATA-4-expressing BMSCs induce differentiation of BMSCs into cardiomyocyte-like cells, decrease anoxia-induced cardiomyocyte apoptosis, and improve myocardial function after infarction.

Injection of Sca-1+/CD45+/CD31+ mouse bone mesenchymal stromal-like cells improves cardiac function in a mouse myocardial infarct model.

The objective of this study was to screen mouse bone marrow mesenchymal stromal cells (BMSCs) according to expression of cardiac stem cell (CSC) surface antigens and to assess the effects of resulting BMSC-like subsets on cardiac function after injection in a mouse myocardial infarct model. BMSCs were sorted by magnetic beads according to the expression of differentiation antigens on the surface of mouse CSCs, and four subsets were identified on the basis of CD45 and CD31 expression: stem cell antigen-1+ (Sca-1+)/CD45-/CD31-, Sca-1+/CD45-/CD31+, Sca-1+/CD45+/CD31-, and Sca-1+/CD45+/CD31+. When co-cultured with myocardial stem cells and 5-aza-2'-deoxycytidine for 14 days, each subset showed expression of cardiac markers α-actin, connexin 43, desmin, and cardiac troponin I; however, expression was greatest in Sca-1+/CD45+/CD31+ cells. To assess the ability of these cells to improve cardiac function, each subset was injected separately into mice with myocardial infarct induced by ligation of the left anterior descending coronary artery, and in vivo cardiac dual inversion recovery (DIR) imaging and Doppler echocardiography were performed 48 h, 96 h, and 7 days after injection. Results indicated that Sca-1+/CD45+/CD31+ cells were superior in improving cardiac function compared with the other subsets and with unsorted BMSCs. These results suggest that mouse BMSC cells are polyclonal and that the BMSC-like Sca-1+/CD45+/CD31+ subset was effective in directing cardiac differentiation and improving cardiac function in mice with myocardial infarcts.

Combined intrathymic and intravenous injection of mesenchymal stem cells can prolong the survival of rat cardiac allograft associated with decrease in miR-155 expression.

BACKGROUND: Mesenchymal stem cells (MSCs) have the potential to improve graft outcomes and promote allograft tolerance. In this study, we examined the effects and mechanism of combined intrathymic (i.t.) and intravenous (i.v.) injection of MSCs on the survival of transplanted hearts in a rat allograft model. METHODS: Recipient Sprague-Dawley rats were transplanted with hearts from Wistar rats. Wistar rat MSCs were infused via i.t. or i.v. or combined i.t. and i.v. (i.t./i.v.) injection at designated intervals. In vitro mixed lymphocyte reaction assays were performed to assess the immunosuppressive capacity of MSCs. Mesenchymal stem cell surface markers and CD4+, CD25+, and Foxp3+ T-cells in the peripheral blood were detected using flow cytometry analysis. The expression of microRNAs and cytokines in graft infiltrating lymphocytes was analyzed by real-time polymerase chain reaction. RESULTS: The MSCs cultured in vitro had multipotential differentiation capacity. Mixed lymphocyte reaction assays showed that donor-derived MSCs could not stimulate a proliferative response of recipient lymphocytes and could markedly suppress T-cell responses. Survival of the allografts was significantly prolonged by administration of i.t./i.v. injection of MSCs compared with controls, with a mean survival of 32.2 versus 6.5 d, respectively. Compared with the syngeneic groups posttransplant, miR-155 expression was significantly increased in the allogeneic group, and could be restored by injection of MSCs, especially i.t./i.v. injection of MSCs. Moreover, i.t./i.v. injection of MSCs decreased the level of interleukin (IL)-2 and interferon-gamma, but increased the levels of IL-4 and IL-10 in the allogeneic group. More important, i.t./i.v. injection of MSCs was the best way to increase the percentage of CD4+, CD25+, and Foxp3+ T-cell peripheral blood. CONCLUSIONS: Our results indicated that i.t./i.v. injection of MSCs can prolong the survival of rat cardiac allograft, which may be associated with down-regulating miR-155 expression, a shift in the Th1/Th2 balance, and up-regulation of Treg cells expression.

[Efficacy of subgroup mouse bone mesenchymal stem cells on mobilizing autologous cardiac stem cells and repairing ischemic myocardial tissue].

OBJECTIVE: To search for the bone mesenchymal stem cell (MSC) subgroup which might be more effective on repairing myocardial damage. METHODS: In this experiment, four MSC subgroups were defined based on the surface differentiation antigen detection of mouse bone mesenchymal stem cells (mBMSCs): SCA-1(+)/CD45(+)/CD31(+), SCA-1(+)/CD45(+)/CD31(-), SCA-1(+)/CD45(-)/CD31(-) and SCA-1(+)/CD45(-)/CD31(+). These subgroup cells and unselected mBMSCs were injected into infarcted mouse via tail vein. Echocardiographic heart function measurement and in vivo DiR-labeled stem cells imaging were performed at 48 h after injection. In situ C-kit (a flag antigen of cardiac stem cells) and cardiac-specific differentiation antigen immunohistochemistry detection was made in the infarcted myocardium. RESULTS: The capacity of the SCA-1(+)/CD45(+)/CD31(+) cells on improving heart function was significantly higher than other cell groups (all P < 0.05). In vivo imaging showed that the mean fluorescence intensity of the SCA-1(+)/CD45(+)/CD31(+) cells was also higher than other cell groups (all P < 0.05). Number of cardiac stem cells in the infracted myocardium was significantly increased after the injection of all subgroup cells and unsorted mBMSCs cells for 48 h compared untreated infracted myocardium. The capacity of mobilizing cardiac stem cells is as follows: SCA-1(+)/CD45(+)/CD31(+) >SCA-1(+)/CD45(-)/CD31(+) >SCA-1(+)/CD45(-)/CD31(-) >SCA-1(+)/CD45(+)/CD31(-). CONCLUSION: The SCA-1(+)/CD45(+)/CD31(+) subgroups of mBMSCs exhibites the highest capacity to improve cardiac function after myocardial infarction and to mobilize autologous cardiac stem cells compared with other mBMSCs subgroups and unsorted mBMSCs cells.

Criteria for determining the need for surgical treatment of tricuspid regurgitation during mitral valve replacement.

BACKGROUND: Tricuspid regurgitation (TR) is common in patients with mitral valve disease; however, there are no straightforward, rapidly determinably criteria available for deciding whether TR repair should be performed during mitral valve replacement. The aim of our retrospective study was to identify a simple and fast criterion for determining whether TR repair should be performed in patients undergoing mitral valve replacement. METHODS: We reviewed the records of patients who underwent mitral valve replacement with or without (control) TR repair (DeVega or Kay procedure) from January 2005 to December 2008. Preoperative and 2-year postoperative echocardiographic measurements included right ventricular and atrial diameter, interventricular septum size, TR severity, ejection fraction, and pulmonary artery pressure. RESULTS: A total of 89 patients were included (control, n = 50; DeVega, n = 27; Kay, n = 12). Demographic and clinical characteristics were similar between groups. Cardiac variables were similar between the DeVega and Kay groups. Right atrium and ventricular diameter and ejection fraction were significantly decreased postoperatively both in the control and operation (DeVega + Kay) group (P < 0.05). Pulmonary artery pressure was significantly decreased postoperatively in-operation groups (P < 0.05). Our findings indicate that surgical intervention for TR should be considered during mitral valve replacement if any of the following preoperative criteria are met: right atrial transverse diameter > 57 mm; right ventricular end-diastolic diameter > 55 mm; pulmonary artery pressure > 58 mmHg. CONCLUSIONS: Our findings suggest echocardiography may be used as a rapid and simple means of determining which patients require TR repair during mitral valve replacement.