Mouse Model Of Transplantation Research Articles

Heterogeneous Intercellular Communication of Hematopoietic Stem Cells in the Mouse Bone Marrow

Introduction.Hematopoietic stem cells (HSCs) are responsible for maintaining the homeostasis of the blood and immune systems. This process must rapidly adapt to bleeding, infection, injury, and disease. HSCs reside in specialized microenvironments in the bone marrow, called “niche”. Several bone marrow cell types have been proposed as the key components of the niche. It is well established that HSCs rely on molecular signals from the niche cells to survive, migrate, proliferate, and differentiate. Recent studies suggest that HSCs differentiate heterogeneously. Additionally, the bone marrow is a heterogeneous environment consisting of more than thirty cell types. This study will test the hypothesis that individual HSCs are engaged in heterogeneous intercellular signaling in the bone marrow. Materials and Methods.We utilized CellChat (Jin et al., 2021), a database for ligand-receptor pairs and associated pathways, to predict cell-cell signaling at the single cell level. We used single cell RNA sequencing data from mouse hematopoietic stem and progenitor cells, blood and immune cells, and non-hematopoietic cells from the bone marrow to determine putative cell-cell interactions. The predicted signaling interactions were then adjusted based on the cell-cell spatial interaction revealed by PhenoCycler measurement (Akoya Biosciences). Mouse bone marrow transplantation experiments were performed to test the functional significance of the identified signaling pathway interactions. Results.We found that individual HSCs send and receive different levels of molecular signals across various signaling pathways. In addition to the expected interactions with the known HSC niche cells, we also found new interactions between HSCs and their progeny cells including myeloid progenitors and immune cells. These cell-cell signaling interactions are consistent with the spatial interaction frequencies of the corresponding cell types as revealed by our imaging data from the PhenoCycler analysis. Further, we found that some signaling pathways are positively or negatively correlated across individual HSCs, indicating complex intercellular signaling networks. The most significant negative correlation was found between HSCs sending MHC-I signals and sending PARs signals (Figure). Moreover, this MHC-I/PARs signaling correlation network also involves signaling from the HSC niche, including those that are known to play roles in HSC homing such as ESAM and VCAM. Therefore, we tested the engraftment efficiency of HSCs that receive PARs and those that do not using the HSC mouse transplantation model. We found that PAR1 + HSCs engraft much less efficiently. Finally, we present the HSC Interaction Data Explorer (HIDE), a database that comprehensively depicts the interactions between HSCs and other bone marrow cells including the involved signaling pathways, ligands and receptors of the pathways, and the pathway correlations. Conclusion.Our study uncovered novel interactions of HSCs with myeloid progenitor cells and immune cells, which were validated by spatial interaction data. These interactions indicate feedback signaling in regulating blood cell regeneration. Our findings further revealed signaling pathway correlation networks across individual HSCs, and we showed their functional significance using transplantation experiments. Finally, we present HIDE as a resource that informs the interactions between HSCs and various bone marrow cells, the relevant signaling pathways, and the pathway correlations. Figure Legend. HSC signaling correlation networks. Each node shows a signaling pathway and direction (e.g., HSCs sending MHC-I). The edges represent the spearman correlation score.

Pgam1 Regulate Adaptive NK Cells in Anti-Viral and Anti-Tumor Response

Natural killer (NK) cells are the innate immune cells that play a role in the anti-viral infections and tumor cells. The adaptive NK cells are characterized with expression of the HLA-E-specific CD94/NKG2C activating receptor. The reconstitution of NKG2C+ adaptive NK cells post HSCT is much faster in NKG2C homozygous(NKG2C wt/wt) donors than NKG2C heterozygous donors (NKG2C wt/del), which resulted in lower incidence of CMV infection. In this study, we aimed to find out the mainly regulators of adaptive NK cells between NKG2C wt/wt and NKG2C wt/del donors. RNA-sequencing analysis were performed. Results shown that NK cells from NKG2C wt/wt donors constant upregulated glycolysis and biosynthesis-related genes, while downregulated in TGF-beta signaling and FOXO signaling pathway(Figure A and B). In order to determine the role of glycolysis in adaptive NK cells, upregulated glycolysis related genes were assessed by q-PCR, and PGAM1 is considered as the most important gene in the expansion of adaptive NK cells(Figure C). PGAM1 is upregulated upon NK cells stimulation via cytokine or target cells, which is related to the CD107a expression. HKB99 is an allosteric inhibitor for PGAM1, which is considered as a potential therapeutic target for many cancers nowadays. NK cells were added with HKB99 in vitro for 12h hours to evaluate the anti-K562 function. After that, Glycolysis is inhibited with the decreasing of ECAR while the OCR is not affected (FigureD). The adding of PGAM1 inhibitor resulted in decreasing of CD107a expression in NK cells, especially in the adaptive NK cells. NK cells activation signaling pathway is also inhibited, including the phosphorylation of mTORC1 protein S6, Syk, zap70, and the PLC-gamma. The PI3K/AKT is inhibited after the PGAM1 inhibition. After that,supplementation of pyruvate is efficient to rescue the inhibition caused by PGAM1 inhibitor. 5mM pyruvate adding can restore the cytokine release of NK cells and the phosphorylation of S6 and syk/zap70(Figure E). PGAM1-NCR-cre mice was constructed in which PGAM1 is knock out in NK cells specifically. In KO group, the ratio of NK cells and the maturation of NK cells are decreased. Upon cytokine stimulation, the activator receptors expression is less in KO mice. Besides, PGAM1 deficiency NK cells exhibited glucose uptake deficiency and disadvantages in proliferation both in vivo and in vitro (Figure F). The differentiation (CD11b+CD27-) and activation marker (DNAM1, Ly49H) are decreased in the competing transplantation mouse model, while the exhaustion markers such as PD-1 and NKG2A is upregulated. Further, MCMV infection models shown that PGAM1 deficiency mice with lower ratio of Ly49H+ adaptive NK cells at the early stage of infection, while Ly49G2 and Ly49C+ cells are not affected(Figure G). Further, Ly49H+ adaptive NK cells shown less expression of Ki67 in PB-NK cells, with the activating markers CD25 is decreased. Higher MCMV load induced inflammation is occurred in PGAM1 deficiency NK cells. Anti-tumor effect was also evaluated. The apoptosis of YAC-1 cells is decrease in coincidence with CD107a expression decreasing. MLL-AF9 leukemia mice model shown in day 18, the Ly49H+ adaptive NK cells in PGAM1 deficiency mice is less than WT mice, and the tumor burden is higher and accompanied with shorter survival under tumor circumstances(Figure H). RNA seq analysis shown compared to WT mice, the downregulated genes in PGAM1 deficiency NK cells are enriched in leukocyte activation and innate immune response also interfered the cytokine-mediated signaling pathway. At last, we monitored expression of PGAM1 and the function of NK cells in patients whose CMV is reactive post HSCT. PGAM1 is elevated post CMV infection, which is correlated with CD107a secretion. ROC curve suggests that PGAM1 may act as a predictor for refractory recurrence CMV infection in patients post HSCT(Figure I). In summary, our studies shown the glycolysis is effectively support the faster adaptive NK cells expansion and CMV response. PGAM1-mediated glycolysis is significant for NK cells anti-tumor and anti-viral function.

Insights into highly engraftable hematopoietic cells from 27-year cryopreserved umbilical cord blood

Umbilical cord blood transplantation is a life-saving treatment for malignant and non-malignant hematologic disorders. It remains unclear how long cryopreserved units remain functional, and the length of cryopreservation is often used as a criterion to exclude older units. We demonstrate that long-term cryopreserved cord blood retains similar numbers of hematopoietic stem and progenitor cells compared with fresh and recently cryopreserved cord blood units. Long-term cryopreserved units contain highly functional cells, yielding robust engraftment in mouse transplantation models. We also leverage differences between units to examine gene programs associated with better engraftment. Transcriptomic analyses reveal that gene programs associated with lineage determination and oxidative stress are enriched in high engrafting cord blood, revealing potential molecular markers to be used as potency markers for cord blood unit selection regardless of length of cryopreservation. In summary, cord blood units cryopreserved for extended periods retain engrafting potential and can potentially be used for patient treatment.

The upregulation of immune checkpoints after photodynamic therapy reducing immune effect for treating breast cancer.

The immune effect induced by photodynamic therapy (PDT) has a limited effect on breast tumor. This study hypothesized that suppressive immune checkpoints on T cells might upregulate after PDT, which may reduce the antitumor effect of PDT for treating breast tumor. This study explored the alteration of immune checkpoint for the first time. A bilateral subcutaneous transplanted breast tumor mice model was established, and right tumors imitated primary tumors, and left tumors imitated distant tumors. Primary tumors were treated with PDT mediated by hematoporphyrin derivatives (HpD-PDT). Costimulatory molecules (ICOS, OX40, and 4-1BB) and immune checkpoints (PD1, LAG-3, CTLA-4, TIM-3, TIGIT) on tumor infiltrating T cells after HpD-PDT were analyzed by flow cytometry. Antitumor and immune effects were also assessed after HpD-PDT combined with anti-PD1 and LAG-3 antibodies. Primary tumors were suppressed, but distant tumors could not be inhibited after HpD-PDT. The number of T cells was increased, but function did not enhance after HpD-PDT. Additionally, costimulatory molecules (ICOS, OX40, and 4-1BB) were not elevated, but the suppressive immune checkpoints on tumor infiltrating T cells were upregulated after HpD-PDT. Notably, PD1+ LAG-3+ CD4+ T and PD1+ LAG-3+ CD8+ T cells were significantly increased. When PD1 and LAG-3 blockade combined with HpD-PDT, both primary and distant tumors were significantly suppressed, and antitumor immune effects were significantly enhanced. HpD-PDT could upregulate the PD1+ LAG-3+ CD4+ T and PD1+ LAG-3+ CD8+ T cells. Dual blockade of PD1 and LAG-3 immune checkpoints can enhance the antitumor effect of HpD-PDT.

CXCR5 + CD8 + T Cell-mediated Suppression of Humoral Alloimmunity and AMR in Mice Is Optimized With mTOR and Impaired With Calcineurin Inhibition.

Adoptive cellular therapy (ACT) with antibody-suppressor CXCR5 + CD8 + T cells (CD8 + T Ab-supp ) inhibits alloantibody production, antibody-mediated rejection (AMR), and prolongs graft survival in multiple transplant mouse models. However, it is not known how conventional immunosuppressive agents impact the efficacy of CD8 + T Ab-supp ACT. We investigated the efficacy of CD8 + T Ab-supp cell ACT when combined with calcineurin inhibitor (CNi) or mammalian target of rapamycin inhibitor (mTORi) in a murine model of kidney transplant. ACT-mediated decrease in germinal center B cells, posttransplant alloantibody titer, and amelioration of AMR in high alloantibody-producing CCR5 knockout kidney transplant recipients were impaired when ACT was combined with CNi and enhanced when combined with mTORi. CNi (but not mTORi) reduced ACT-mediated in vivo cytotoxicity of IgG + B cells and was associated with increased quantity of germinal center B cells. Neither CNi nor mTORi treatment impacted the expression of cytotoxic effector molecules (FasL, Lamp1, perforin, granzyme B) by CD8 + T Ab-supp after ACT. Concurrent treatment with CNi (but not mTORi) reduced in vivo proliferation of CD8 + T Ab-supp after ACT. The increase in quantity of splenic CD44 + CXCR5 + CD8 + T cells that occurs after ACT was reduced by concurrent treatment with CNi but not by concurrent treatment with mTORi (dose-dependent). Impaired efficacy of ACT by CNi is attributed to reduced persistence and/or expansion of CD8 + T Ab-supp cells after ACT. In contrast, concurrent immunosuppression with mTORi preserves CD8 + T Ab-supp cells quantity, in vivo proliferation, and in vivo cytotoxic effector function after ACT and enhances suppression of humoral alloimmunity and AMR.

THU083 Disulfiram Mediated Anti-tumor Effect In Pituitary Neuroendocrine Tumors By Inducing Cuproptosis

Abstract Disclosure: N. Huang: None. Y. Zhang: None. Y. Liu: None. Y. Feng: None. L. Xue: None. Z. Wu: None. Pituitary neuroendocrine tumors (PitNETs) are common intracranial tumors. Dopamine agonists and somatostatin analogues are the first-line drugs for PRL and GH-secreting PitNETs clinically. However, there is no effective drug for other subtypes and drug-resistant PitNETs. Thus, it’s impending to discover new therapeutic targets and medicine. Cuproptosis is a copper-dependent form of cell death driven by lipoylated protein aggregation, loss of Fe-S cluster-containing proteins, and induction of HSP70. However, the role of cuproptosis in PitNETs is not clear. In this study, a total of 17 primary samples of PitNETs were collected to perform high-throughput drug screening, an anti-abuse drug disulfiram (DSF) was identified that can induce cell death effectively. We found that disulfiram also has a strong inhibitory effect on pituitary tumor cell lines MMQ, Att20 and GH3 (-87.1%, -62.5%, -92.7%, p<0.001), but the inhibitory effect was eliminated by copper chelator TTM/BCS. This indicated that DSF played the anti-tumor effect requiring the participation of copper ions. To explore the underlying mechanism that DSF induces the cell death of PitNETs, we detected the hallmark of cuproptosis and found that DSF leads to a decrease in the acylation level of proteins related to the tricarboxylic acid cycle, limiting the function of the protein. On the one hand, DSF leads to the downregulation of iron-sulfur cluster-associated proteins, and the oligomerization of dihydrolipoamide S-acetyltransferase (DLAT), which is eventually accompanied by an increase in the protein level of heat shock protein 70 (HSP70) at protein and mRNA level, causing proteotoxic stress leading to cell death. Finally, DSF treatment inhibited the tumor growth in MMQ cell transplanted mouse model and destructed the morphology of the pituitary tumor 3D sphere similarly demonstrating the inhibition effect. In conclusion, we find that the anti-abuse drug disulfiram can induce coproptosis in pituitary tumor cells in a copper-dependent manner and is a potential drug for the treatment of PitNETs. Presentation: Thursday, June 15, 2023

Gut microbiota aggravates neutrophil extracellular traps-induced pancreatic injury in hypertriglyceridemic pancreatitis

Hypertriglyceridemic pancreatitis (HTGP) is featured by higher incidence of complications and poor clinical outcomes. Gut microbiota dysbiosis is associated with pancreatic injury in HTGP and the mechanism remains unclear. Here, we observe lower diversity of gut microbiota and absence of beneficial bacteria in HTGP patients. In a fecal microbiota transplantation mouse model, the colonization of gut microbiota from HTGP patients recruits neutrophils and increases neutrophil extracellular traps (NETs) formation that exacerbates pancreatic injury and systemic inflammation. We find that decreased abundance of Bacteroides uniformis in gut microbiota impairs taurine production and increases IL-17 release in colon that triggers NETs formation. Moreover, Bacteroides uniformis or taurine inhibits the activation of NF-κB and IL-17 signaling pathways in neutrophils which harness NETs and alleviate pancreatic injury. Our findings establish roles of endogenous Bacteroides uniformis-derived metabolic and inflammatory products on suppressing NETs release, which provides potential insights of ameliorating HTGP through gut microbiota modulation.

Initial exploration of a novel fusion protein, IL-4/IL-34/IL-10, which promotes cardiac allograft survival mice through alloregulation.

Immune mediated graft loss still represents a major risk to transplant recipients. Creative approaches to immunosuppression that exploit the recipient's own alloregulatory mechanisms could reduce the need for pharmacologic immunosuppression and potentially induce immune tolerance. In the process of studying recipient derived myeloid derived suppressor cells (MDSCs), we identified key alloregulatory MDSC mechanisms, mediated by isolatable proteins IL-4, IL-34, and IL-10. We sought to purify these proteins and fuse them for subsequent infusion into transplant recipients as a means of inducing an alloregulatory response. In this introductory investigation, we leveraged molecular engineering technology to create a fusion protein (FP) of three cytokine coding sequences of IL-4, IL-34, and IL-10 and demonstrated their expressions by Western Blot analysis. Following purification, we tested whether FP IL-4/IL-34/IL-10 (FP1) can protect heart transplant allografts. Injection of FP1 significantly prolonged allogeneic cardiac graft survival in a dose-dependent fashion and the increase of graft survival time exceeded survival attributable to IL-34 alone. In vitro, MDSCs cells were expanded by FP1 treatment. However, FP1 did not directly inhibit T cell proliferation in vitro. In conclusion, newly developed FP1 improves the graft survival in cardiac transplantation mouse model. Significant additional work to optimize FP1 or include other novel proteins could supplement current treatment options for transplant patients.

Synthesis of mizoribine prodrugs and their in vivo evaluation as immunosuppressive agents

Mizoribine is a well-known immunosuppressive drug, based on a nucleoside scaffold, that targets inosine-monophosphate dehydrogenase (IMPDH). In an effort to increase its in vivo efficacy, three different types of prodrugs (a phosphoramidate prodrug, a lipophilic ester derivative and an amino acid conjugate) were prepared. Screening of these prodrugs in a rapid whole blood assay revealed that the two ester-based mizoribine prodrugs potently inhibited interleukin 2 secretion. Moreover, these prodrugs were able to prolong graft survival, when evaluated in a mouse model of cardiac allograft transplantation. Strikingly, a combination therapy of these mizoribine prodrugs with tacrolimus had a synergistic in vivo effect.

Establishment and evaluation of a modified mouse model of renal subcapsular transplantation of microvolume cells

The renal subcapsular space provides an easily accessible, nutrition-rich pocket that supports engraftment, and as such, is often used as a site for stem and cancer cell transplantation. Renal capsule transplantation requires high technical requirements, the recipient mice have greater surgical damage, the mouse kidney is small and the kidney capsule is fragile, and the operation is easy to fail. The conventional method is not suitable for microvolume cell transplantation to this site in animals with a small kidney, such as mice, due to high risks of cell loss or dislocation or injury to the capsule. In this study, we developed and validated a modified approach for the mouse model of renal subcapsular transplantation of microvolume mouse skeletal stem cells (SSCs). We used a pipette with a refined tip to separate the capsule from the parenchyma. Moreover, we used cells suspended in Matrigel rather than a liquid carrier for transplantation. Using the modified method, we were able to transplant microvolume mouse SSCs as low as 0.2 μL beneath the mouse renal capsule with excellent reproducibility. After 4 weeks of in vivo culture, the implanted mouse SSCs formed grafts on the surface of the parenchyma at the target site of transplantation. Histological staining of the grafts indicated osteogenic, fibrogenic, and lipogenic differentiation. Micro-CT imaging of the grafts revealed bone formation. This modified model could be used to effectively transplant different types of microvolume cells to the renal subcapsular space when the donor cells are difficult to acquire or the recipient mice have a very small size kidney.

Exploring cardiac impact of oral nicotine exposure in a transplantable Neoplasm Mice Model: Insights from biochemical analysis, morphometry, and molecular docking: Chlorella vulgaris green algae support

Nicotine-induced cardiac tissue damage is a concern for cancer patients, but the exact pathogenesis from nicotine oral exposure is unclear. This study was designed to investigate the impact of nicotine and Chlorella vulgaris (Ch. V) on cardiac glutathione homeostasis, inflammatory response, cardiac damage markers, apoptotic proteins and histopathological findings in an experimentally transplantable neoplasm mouse model (Ehrlich ascites carcinoma; EAC). In the in-vivo experiment, the female Swiss mice were divided into four groups: control, Ch.V (100 mg/kg), Nicotine (100 µg/ml/kg), and a combination group ( Nocotine+ Ch.V) for 40 days. Furthermore, in this study,the effects of C. vulgaris components on caspase-3, TNF-α, and IL-1β activity were explored using Molecular Operating Environment (MOE) docking software to ensure its ability to counteract the toxic effects of nicotine. The results indicated that nicotine has induced significant (P < 0.001) cardiopathic alterations in EAC-bearing mice with changes in cardiac tissue enzymes. C. Vulgaris attenuated the nicotine-induced cardiac glutathione inhibition, suppressed the inflammatory response, exerted antiapoptotic effects, mitigated myocardial injury biomarkers, and repaired cellular and tissue damage. Moreover, the molecular docking results revealed the ability of C. vulgaris to bind with interleukin-1 receptor type 1 (IL1R1) and tumor necrosis factor receptor superfamily member 1 A (TNFRSF1A) in the mice tissues, ameliorating apoptosis and inflammatory processes associated with nicotine-induced cardiotoxicity. This study provides a model for understanding nicotine-induced myocardial injury during experimentally transplantable neoplasm. It highlights C. vulgaris as a beneficial food supplement for cancer patients exposed to nicotine orally.

IMM47, a humanized monoclonal antibody that targets CD24, exhibits exceptional anti-tumor efficacy by blocking the CD24/Siglec-10 interaction and can be used as monotherapy or in combination with anti-PD1 antibodies for cancer immunotherapy.

This study evaluates the anti-tumor mechanism of IMM47, a humanized anti-CD24 mAb. Biolayer interferometry, ELISA and flow cytometry methods were used to measure the IMM47 binding, affinity, ADCC, ADCP, ADCT and CDC activities. In vivo therapeutical efficacy was measured in transplanted mouse models. IMM47 significantly binds granulocytes but not human erythrocytes and blocks CD24's ability to bind to Siglec-10. IMM47 has strong ADCC, ADCT and ADCP activity against REH cells. IMM47's in vivo pharmacodynamics showed that IMM47 has strong anti-tumor effects in human siglec-10 transgenic mouse models with a memory immune response. IMM47 also has powerful synergistic therapeutic efficacy when combined with Tislelizumab, Opdivo and Keytruda, by blocking CD24/Siglec-10 interaction through macrophage antigen presentation with strong ADCC, ADCP, ADCT and CDC activities and with a safe profile. IMM47 binding to CD24 is independent of N-glycosylation modification of the extracellular domain.

Abstract 16 Insights into Highly Engraftable Hematopoietic Cells from 27-Year Cryopreserved Umbilical Cord Blood

Abstract Introduction Cord blood banking has consistently outpaced the utilization of cord blood units (CBUs). Thus, the average duration of cryopreservation among banked CBUs will likely continue to increase. It remains unclear how long cryopreserved CBUs remain functional, and it is critical to determine whether duration of cryopreservation should be used as an exclusionary criterion during selection for clinical use or if alternative post-thaw metrics can identify potent cryopreserved CBUs regardless of age. Objectives Our goal was to determine whether long-term (27-year) cryopreserved CBUs retain viable and functional hematopoietic stem (HSCs) and progenitor cells (HPCs). We further sought to leverage differences in HSC/HPC function (measured by in vivo engraftment) to demonstrate the utility of using omics approaches to identify candidate genes for use as molecular potency markers. Methods We performed comprehensive ex vivo, in vivo, and molecular analyses on the numbers, viability, and function of three 27-year cryopreserved CBUs using 3-year cryopreserved and fresh CBUs for comparison. Assays included viability staining, immunophenotyping by flow cytometry, primary and secondary colony forming unit (CFU) assays, ex vivo expansion of immunophenotypic HSCs/HPCs/CFUs, limiting dilution transplantations into immune-deficient mice, secondary transplantations, and RNA-sequencing of sorted HSCs and multipotent progenitor cells. Results Compared to fresh and recently cryopreserved CBU controls, long-term cryopreserved CBUs yield statistically similar numbers of viable immunophenotypic HSCs, multipotent HPCs, and committed myeloid and lymphoid HPCs. They retain highly functional cells, demonstrating similar primary and secondary CFU numbers and expansion capacity compared to controls, as well as robust engraftment, SCID repopulating cell frequency, and secondary engraftment capacity in mouse models of transplantation. Transcriptomic modelling revealed 18 genes, including MALT1 and MAP2K1, and several gene programs, including lineage determination programs and oxidative stress responses, that are strongly enriched in high engrafting HSCs/HPCs. Discussion CBUs cryopreserved for up to 27 years retain highly functional HSCs/HPCs. Thus, duration of cryopreservation alone is not an ideal exclusionary criteria for selection of CBUs. Preserving older CBUs may help to maintain a large and diverse pool of donors for clinical selection. Further, transcriptomics can identify candidate genes associated with engraftment for elucidation of possible CBU potency markers regardless of the duration of cryopreservation.

Polymorphonuclear myeloid-derived suppressor cells and phosphatidylinositol-3 kinase gamma are critical to tobacco-mimicking oral carcinogenesis in mice

BackgroundOral squamous cell carcinoma (OSCC) is a devastating disease most often associated with tobacco consumption that induces a field of mutations from which a tumor arises. Identification of ways to...

YY1 regulates the proliferation and invasion of triple-negative breast cancer via activating PLAUR.

It is well-established that breast cancer is a highly prevalent malignancy among women, emphasizing the need to investigate mechanisms underlying its pathogenesis and metastasis. In this study, the Gene Expression Omnibus (GEO) database was utilized to conduct differential expression analysis in breast cancer and adjacent tissues. Upregulated genes were selected for prognostic analysis of breast cancer. The expression of urokinase plasminogen activator receptor (uPAR), also known as PLAUR, was assessed using RT-qPCR and western blot. Immunofluorescence staining was employed to determine PLAUR localization. Various cellular processes were analyzed, including proliferation, migration, invasion, apoptosis, and cell cycle. Bioinformatics analysis was used to predict transcription factors of PLAUR, which were subsequently validated in a double luciferase reporter gene experiment. Rescue experiments confirmed the impact of PLAUR on the proliferation, apoptosis, and migration of MDA-MB-231 cells. Furthermore, the effects of PLAUR were evaluated in an orthotopic tumor transplantation and lung metastasis nude mouse model. Our findings substantiated the critical involvement of PLAUR in the progression of triple-negative breast cancer (TNBC) in vitro and among TNBC patients with a poor prognosis. Additionally, we demonstrated Yin Yang-1 (YY1) as a notable transcriptional regulator of PLAUR, whose activation could transcriptionally enhance the proliferation and invasion capabilities of TNBC cells. We also identified the downstream mechanism of PLAUR associated with PLAU, focal adhesion kinase (FAK), and AKT. Overall, these findings offer a novel perspective on PLAUR as a potential therapeutic target for TNBC.

Impaired thymic iNKT cell differentiation at early precursor stage in murine haploidentical bone marrow transplantation with GvHD.

Early recovery of donor-derived invariant natural killer T (iNKT) cells are associated with reduced risk of graft-versus-host disease (GvHD) and overall survival. Patients with severe GvHD, however, had much slower iNKT cell reconstitution relative to conventional T cells. To characterize the delay of iNKT cell reconstitution and explore its possible causes, we used a haploidentical bone marrow transplantation (haplo-BMT) mouse model with GvHD. We found the delayed recovery of thymic and peripheral iNKT cell numbers with markedly decreased thymic NKT1 subset in GvHD mice. The defective generation of thymic iNKT precursors with egress capability contributed to the reduced peripheral iNKT cells in GvHD mice. We further identified intermediate NK1.1- NKT1 precursor subpopulations under steady-state conditions and found that the differentiation of these subpopulations was impaired in the thymi of GvHD mice. Detailed characterization of iNKT precursors and thymic microenvironment showed a close association of elevated TCR/co-stimulatory signaling provided by double positive thymocytes and macrophages with defective down-regulation of proliferation, metabolism, and NKT2 signature in iNKT precursor cells. Correspondingly, NKT2 but not NKT1 differentiation was favored in GvHD mice. These data underline the important roles of TCR and co-stimulatory signaling in the differentiation of thymic iNKT subsets under transplantation conditions.

Semaphorin 3 C enhances putative cancer stemness and accelerates peritoneal dissemination in pancreatic cancer

PurposeSemaphorins, axon guidance cues in neuronal network formation, have been implicated in cancer progression. We previously identified semaphorin 3 C (SEMA3C) as a secreted protein overexpressed in pancreatic ductal adenocarcinoma (PDAC). We, therefore, hypothesized that SEMA3C supports PDAC progression. In this study, we aimed to investigate the clinical features of SEMA3C, especially its association with chemo-resistance and peritoneal dissemination.MethodsIn resected PDAC tissues, we assessed the relationship between SEMA3C expression and clinicopathological features by immunohistochemistry. In vitro studies, we have shown invasion assay, pancreatosphere formation assay, colony formation assay, cytotoxicity assay, and activation of SEMA3C downstream targets (c-Met, Akt, mTOR). In vivo, we performed a preclinical trial to confirm the efficacy of SEMA3C shRNA knockdown and Gemcitabine and nab-Paclitaxel (GnP) in an orthotopic transplantation mouse model and in peritoneal dissemination mouse model.ResultsIn resected PDAC tissues, SEMA3C expression correlated with invasion and peritoneal dissemination after surgery. SEMA3C promoted cell invasion, self-renewal, and colony formation in vitro. We further demonstrated that SEMA3C knockdown increased Gem-induced cytotoxicity by suppressing the activation of the Akt/mTOR pathway via the c-Met receptor. Combination therapy with SEMA3C knockdown and GnP reduced tumor growth and peritoneal dissemination.ConclusionsSEMA3C enhances peritoneal dissemination by regulating putative cancer stemness and Gem resistance and activates phosphorylation of the Akt/mTOR pathway via c-Met. Our findings provide a new avenue for therapeutic strategies in regulating peritoneal dissemination during PDAC progression.

Construction of a Mouse Model for Myeloproliferative Neoplasms and an Evaluation System

To construct a myeloproliferative neoplasms (MPN) transplanted mouse model with JAK2-V617F, MPLW515L or CALR-Type I gene mutation, and establish a systematic evaluation system to verify the success of model construction. The bone marrow c-kit+ cells of the mice were obtained by the following steps: The mice were killed by cervical dislocation, the femur, tibia and ilium were separated, and the bone marrow cells were collected. The c-kit+ cells were sorted after incubation with CD117 magnetic beads. The method of constructing mouse primary mutant cells is as follows: A gene mutation vector with a GFP tag was constructed by the retroviral system, and the retroviral vector was packaged into the Platinum-E cells to obtain the virus supernatant, and then used it to infect the c-kit+ cells of mice. The MPN mouse model was constructed as follows: the mouse primary c-kit+ cells containing the mutant genes were collected after infection, and then transplanted them via the tail vein into the female recipient mice of the same species which were irradiated with a lethal dose of gamma rays (8.0 Gy). The MPN mouse model was evaluated as follows: After transplantation, the peripheral blood of the mice was regularly collected from the tail vein to perform the complete blood count test, and the size of spleen and the degree of bone marrow fibrosis were estimated. The mouse c-kit+ cells with the mutant genes were successfully obtained from the bone marrow. MPN mouse model was successfully constructed: The peripheral blood cells of the MPN-transplanted mice carried exogenous implanted GFP-positive cells, and the white blood cells (WBC), platelet (PLT) and hematocrit (HCT) were all increased; the body weight loss, and the water and food intake were reduced in the transplanted mice; further pathological analysis showed that the transplanted mice displayed splenomegaly and bone marrow fibrosis. These results suggested that the MPN mouse model was successfully constructed. According to the common and different characteristics of the three MPN mouse model, a preliminary evaluation system for judging the success of MPN mouse model construction was summarized, which mainly included the following indicators, for example, the proportion of GFP-positive cells in the peripheral blood of mice; WBC, PLT and HCT; the degree of spleen enlargement and the bone marrow fibrosis. The MPN mouse model with JAK2-V617F, MPLW515L or CALR-Type I gene mutation is successfully established by retroviral system, which can provide an important experimental animal model for the research of MPN pathogenesis and drug-targeted therapy.

Establishment and characterization of a novel cell line and xenotransplant mouse model derived from feline colorectal adenocarcinoma.

Colorectal adenocarcinoma is an aggressive malignant tumor in cats that frequently metastasizes to the lymph nodes and/or distant organs. However, research on feline colorectal adenocarcinoma is limited, and experimental models have not been established. A novel cell line, FeLeco-G7, was established from the lymph node of a 12-year-old spayed female Maine Coon cat with metastatic colorectal adenocarcinoma. FeLeco-G7 cells were polygonal with abundant cytoplasm and adherent growth. The population-doubling time was approximately 28.3 hours, and the mean number of chromosomes was 37.6±0.1 per cell (ranging between 32 and 41). Consistent with the original tumor, FeLeco-G7 cells were immunopositive for cytokeratin (CK) 20 and CDX2, and immunonegative for CD10 and CK7. Nuclear accumulation of β-catenin was rarely observed. Mutation analysis suggested TP53 gene alterations. A subcutaneous injection of FeLeco-G7 cells into immunodeficient mice resulted in the formation of a mass at the injection site without the development of metastatic lesions. An orthotopic (intrarectal) transplantation of FeLeco-G7 cells caused cachexia and diffuse involvement of the rectal mucosa in one of the 3 mice and the formation of masses around the rectum in the other 2 mice. Metastases to the regional lymph nodes and lungs were detected in three of the 3 and one of the 3 mice, respectively. The histological findings and immunohistochemical features of these masses were similar to those of the original tumor. These results suggest that FeLeco-G7 cells and the orthotopically transplanted mouse model are valuable tools for further molecular and therapeutic research on feline colorectal adenocarcinoma.

Effects of different allo-Treg/allo-NK ratios on graft-versus-host disease in transplanted mice

To investigate the effects of allo-Treg cells, allo-NK cells, and their mixtures in different proportions on Graft-versus-host disease (GVHD) in bone marrow transplant mouse model. In this study, C57BL/6 mice were used as donors, and 6 Gy dose of 60Co γ was used as the receptor of BALB/c mice. The recipient mice were divided into NC (normal saline), CON (bone marrow cells), NK (bone marrow cells + NK cells), Treg (bone marrow cells + Treg cells), NK+ Treg (1:1) (bone marrow cells +1:1 ratio of Treg cells, NK cells), and NK+ Treg (6:1) (bone marrow cells +1:6 ratio of Treg cells, NK cells), according to the different injection mode through the tail vein. The differences of white blood cell (WBC), platelet (PLT), clinical manifestations, and GVHD score of target organs (liver, lung, small intestine) in each group after transplantation were observed, and the differences of chimerism rate and survival rate in each group at 28 days after transplantation were compared. The interaction between Treg cells and NK cells in different proportions (1:1, 1:2, 1:6, 1:12) was investigated in vitro in mouse erythroleukemia (MEL) cells of mouse erythroleukemia. The results showed that at the 28th day of transplantation, the clinical manifestations and GVHD scores of target organs of mice in NK+ Treg (1:1) group and NK+ Treg (6:1) group were significantly lower than other groups (P < 0.05); the WBC and PLT counts were significantly higher than other groups (P < 0.05), and the survival time was significantly longer than other groups (P < 0.05); the clinical manifestations and GVHD scores of each target organ in NK+ Treg (1:1) group were significantly lower than those in NK+ Treg (6:1) group (P < 0.05); the chimerism rate of each group was >90% on day 28 after transplantation. In vitro experiments showed that the inhibition of Treg cells on NK cell killing activity was dose-dependent, and the proportion of 1:6 and 1:12, killing activity of NK cell was significantly lower than that of groups 1:1 and 1:2 (P < 0.05), which showed that allo-NK and allo-Treg alone had a significant effect on the improvement of GVHD after transplantation, and Treg cells inhibited the killing activity of NK cells by direct contact and showed a dose-dependent effect.