Background: Crohn’s disease (CD) and peripheral arterial disease (PAD) are closely related. The pathophysiological mechanisms underlying the coexistence of CD and PAD are unknown. The aim of this study was to investigate the key molecules and pathways mediating the co-occurrence of CD and PAD through quantitative bioinformatic analysis of a public RNA sequencing database. Methods: Datasets of CD (GSE111889) and PAD (GSE120642) were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were analyzed using the ‘edgeR’ and ‘limma’ packages of R. Gene Ontology and Kyoto Encyclopedia analyses of common DEGs were performed to explore the functions of DEGs. Protein–protein interaction (PPI) networks were established by the Search Tool for the Retrieval of Interacting Genes (STRING) database and visualized by Cytoscape. Hub genes were selected using the plugin cytoHubba. Hub gene validation was performed in GSE95095 for CD and GSE134431 for PAD. Receiver operating characteristic curves were used to evaluate the predictive values of the hub genes. Gene set enrichment analysis and immune infiltration of the hub genes were performed. Results: A total of 54 common DEGs (2 downregulated and 52 upregulated) were identified. Pathways of neutrophil chemotaxis, neutrophil migration and cytokine and cytokine receptors were enriched in CD and PAD. S100A8, S100A9, S100A12 and CXCR2 were identified as hub genes after validation, with all area under the curve > 0.7 for both CD and PAD. Neutrophil infiltration was associated with upregulation of the hub genes. Pathways of immune processes, including neutrophil activation, neutrophil chemotaxis, neutrophil migration were significantly correlated with high expression of S100A8, S100A9, S100A12 and CXCR2 in both CD and PAD. Conclusions: This bioinformatic study elucidates S100A8, S100A9, S100A12 and CXCR2 as hub genes for the co-occurrence of Crohn’s disease and peripheral artery disease. Inflammation and immune regulation modulated by neutrophil infiltration play a central role in the development of CD and PAD and may be potential targets for diagnosis and treatment.

Background: Mesenchymal stem cells (MSCs) can improve limb perfusion and increase vessel density in a murine model of hindlimb ischemia. But low engraftment rate of those cells limited their therapeutic effect. Endothelial cells (ECs) play an important role in neovascularization. And MSCs can differentiate into ECs in vitro. The aim of this study is to investigate if EC differentiation of MSCs in vitro before transplantation is effective in improving therapeutic outcomes in the treatment of ischemic disease in a murine ischemia animal model. Methods: MSCs were isolated from the bone marrow of EGFP-transgenic mice by density gradient centrifugation. The identity of the MSCs was determined by their cluster of differentiation (CD) marker profile by flow cytometry. Inducing medium containing a few cytokines was applied to induce the MSCs to differentiate into ECs. Endothelial differentiation was quantitatively evaluated using flow cytometry, quantitative real-time PCR (qRT-PCR), immunofluorescence, Matrigel tube formation assay, and Dil-labeled acetylated low-density lipoprotein uptake assay. Mouse hindlimb ischemia model was made by excision of the femoral artery. Uninduced EGFP+ MSCs, induced EGFP+ MSCs, and PBS were intramuscularly injected into the gastrocnemius following ischemia no later than 24 h after operation. Restoration of blood flow and muscle function was evaluated by laser Doppler perfusion imaging. Immunofluorescence was conducted to evaluate the engraftment of transplanted MSCs. Histological analysis was performed to evaluate blood vessel formation. Results: Induced EGFP+ MSCs expressed endothelial markers and exhibited tube formation capacity. Mice in the induced EGFP+ MSCs group had a better blood perfusion recovery, enhanced vessel densities, higher engraftment, and improved function of the ischemic limb than those in the uninduced EGFP+ MSCs or PBS groups. Conclusions: This study reveals that after short-term pre-treatment in the EC-inducing medium, induced MSCs acquire stronger vessel formation capability and enhanced angiogenic therapeutic effect in the murine hindlimb ischemia model.

Purpose: To evaluate the role of Decitabine in the allo-HSCT conditioning regimen for intermediate- and high-risk patients with MDS or AML. Patients and methods: Retrospective analysis of data pertaining to 76 intermediate- and high-risk patients with MDS or AML who underwent allo-HSCT between December 2005 and June 2018 at the Peking University First Hospital. Forty patients received Decitabine-containing conditioning regimen before transplantation, while thirty-six patients received regimen without Decitabine. Results: Over a median follow-up of 40 months (range, 1 to 155), the cumulative incidence of grade II to IV acute graft versus host disease was 12.4% [95% confidence interval (CI) 4.9–30.9%] in the Decitabine group and 41.5% (95% CI 28.1–61.2%) in the non-Decitabine group (P=0.005). On multivariate analysis, Decitabine-containing conditioning regimen was found to protect against grade II to IV aGVHD (HR=0.279, 95% CI 0.102–0.765, P=0.013). Incidence of respiratory infection in the Decitabine and non-Decitabine groups was 22.5% and 52.78%, respectively (P=0.012). No significant between-group difference was observed with respect to 3-year OS, DFS, or RR (P=0.980, 0.959, and 0.573, respectively), while the median relapse time was longer in the Decitabine group [7 months (range, 2–12) versus 3 months (range, 2–4), P=0.171]. Decitabine-containing conditioning showed a tendency for lower relapse rate among higher risk patients, as assessed by IPSS R; however, the between-group difference was not statistically significant (P=0.085). Conclusion: Inclusion of Decitabine in the conditioning regimen for allo-HSCT in intermediate- and high-risk patients may lower the incidence of aGVHD and respiratory infections, and contribute to longer median relapse time.

Background: Idiopathic pneumonia syndrome (IPS) is a non-infectious fatal complication characterized by a massive infiltration of leukocytes in lungs and diffuse pulmonary injury after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Conventional immunosuppressive treatments for IPS have poor therapeutic effects. Safe and effective treatments are not yet available and under explorations. Our previous study demonstrated that mesenchymal stem cells (MSCs) can alleviate IPS, but the mechanisms remain unclear. Methods: Co-cultured pre-activated T cells and MSCs in vitro to observe the changes in the CCR2-CCL2 axis. By establishing an IPS mouse model and administering MSCs to further verify the results of in vitro experiments. Results: Co-culture of pre-activated T cells with MSCs in vitro modulated the CCR2-CCL2 axis, resulting in quiescent T cells and polarization toward CCR2⁺CD4⁺ T cell subsets. Blocking CCR2-CCL2 interaction abolished the immunoregulatory effect of MSCs, leading to re-activation of T cells and partial reversion of polarizing toward CCR2⁺CD4⁺ T cells. In IPS mouse model, application of MSCs prolonged the survival and reduced the pathological damage and T cell infiltration into lung tissue. Activation of CCR2-CCL2 axis and production of CCR2⁺CD4⁺ T cells were observed in the lungs treated with MSCs. The prophylactic effect of MSCs on IPS was significantly attenuated by the administration of CCR2 or CCL2 antagonist in MSC-treated mice. Conclusions: We demonstrated an important role of CCR2-CCL2 axis in modulating T cell function which is one of the mechanisms of the prophylactic effect of MSCs on IPS.