Long tracheal lesions are mainly caused by stenosis, infection, trauma, malignant tumors and other factors. Resection of the diseased tissue or stenosis and end-to-end anastomosis is currently the gold standard for long tracheal lesions treatment. However, these treatment programs have proven to have major limitations. In recent years, tissue engineering technology has been regarded as a promising medical alternative treatment method, and the selection of scaffold materials is one of key parts. With the continuous exploration of domestic and foreign researchers, biological materials have been continuously developed and applied to the research of tissue engineering trachea. Tissue engineering degradable scaffold materials can be divided into natural polymer material scaffolds and synthetic polymer scaffolds according to the different sources. The scaffold material can be modified or compounded as needed to improve the biological properties of scaffolds. In addition, with the continuous development of biological printing technology, different scaffold materials can be better combined and used. Biodegradable scaffolds have become a new research direction in the field of tissue engineering trachea due to their polymer properties, and have good application prospects.

Objective: To explored the bio-compatibility and cartilage regeneration of the rabbits genipin cross-linked decellularized scaffold, to provide experimental and theoretical support for the clinical application of genipin cross-linked decellularized scaffold. Methods: Detergent-enzyme method was used to prepare decellularized tracheal scaffolds. Cellular content of native trachea and decellularized trachea were compared by 4′, 6-diamidino-2-phenylindole(DAPI) staining. Masson trichrome staining was used to compare the histological structure of the progenitor tube, decellularized trachea, and genipin cross-linked decellularized trachea. Nine adult New Zealand white rabbits were randomly divided into autologous tracheal transplantation group (negative control group), allogeneic tracheal transplantation group (positive control group), and genipin cross-linked decellularized tracheal transplantation group (experimental group). Autologous bone marrow mesenchymal stem cells were implanted on the surface of trachea in each group. The blood cells and type II collagen were detected to compare the inflammatory response and chondrocyte regeneration after tracheal orthotopic transplantation in the three groups. Results: After DAPI staining and light microscope observation (×200), the cell content of the acellular 7-cycle trachea [(143.0 ± 71.1) cells/field] was significantly lower than that of the native trachea [(853.5 ± 149.6) cells/field], and the difference was statistically significant (P<0.001). Masson′s trichrome staining showed that the tissue structure of genipin cross-linked decellularized trachea was more complete. Blood cell analysis and type II collagen test results showed that genipin cross-linked decellularized trachea transplanted with bone marrow mesenchymal stem cells after transplantation in situ has little rejection and can be converted into chondrocytes by the action of related growth factors in vivo. Conclusions Genipin cross-linked decellularized tracheal scaffold combined with stem cell transplantation can successfully construct a tracheal in situ replacement model. This study provides a strong support for the research of tissue engineering trachea.

[摘 要] 目的：探索甲硫氨酸腺苷转移酶2（MAT2A）对食管鳞状细胞癌（ESCC）细胞的作用，以及MAT2A抑制剂PF9366对ESCC细胞的抑制作用及其分子机制。方法：选用人ESCC细胞KYSE450、KYSE510、KYSE180和KYSE410及正常食管上皮细胞（NEEC），通过ELISA实验验证S-腺苷甲硫氨酸（SAM）在细胞中的产生情况。分别用0、5、10和25 μmol/L PF9366处理KYSE450、KYSE510细胞，通过ELISA实验、MTS实验、平板克隆形成实验检测PF9366对ESCC细胞甲硫氨酸（MET）活性和细胞增殖的抑制效果，采用RNA-seq实验观察PF9366对KYSE450细胞下游促癌信号通路的影响。构建KYSE450、KYSE510细胞移植瘤小鼠模型，观察PF9366对荷瘤小鼠移植瘤生长的影响。结果：ESCC细胞中的MET活性显著高于NEEC（均P < 0.01）。使用PF9366后，KYSE450、KYSE510细胞SAM活性均显著降低（均P < 0.01），细胞的增殖能力显著降低（均P < 0.01），其抑制作用呈现出明显的剂量依赖性（均P < 0.05）。RNA-seq分析表明，PF9366处理后的ESCC细胞中，有20个与肿瘤发生和发展相关的信号通路被下调。荷瘤小鼠实验表明，PF9366能显著抑制ESCC细胞小鼠移植瘤的生长（均P < 0.000 1）。结论：MAT2A抑制剂PF9366能抑制ESCC细胞中SAM的产生、抑制细胞增殖并激活下游关键促癌信号网络，提示MET代谢关键酶MAT2A是治疗ESCC的潜在靶点。

BACKGROUND: Different decellularization methods can affect the integrity and the biomechanical and biocompatible properties of the tracheal matrix. Natural cross-linking with genipin can be applied to improve those properties. The goals of this study were to evaluate the effects of different decellularization methods on the properties of genipin-cross-linked decellularized tracheal matrices in rabbits. METHODS: The tracheas of New Zealand rabbits were decellularized by the Triton-X 100-processed method (TPM) and the detergent-enzymatic method (DEM) and were then cross-linked with genipin. Mechanical tests, haematoxylin-eosin staining, Masson trichrome staining, Safranin O staining, DAPI staining, scanning electronic microscopy (SEM), and biocompatibility tests were used to evaluate the treatment. The bioengineered trachea and control trachea were then implanted into allogeneic rabbits for 30 days. The structural and functional analyses were performed after transplantation. RESULTS: The biomechanical tests demonstrated that the biomechanical properties of the decellularized tracheas decreased and that genipin improved them (p < 0.05). The histological staining results revealed that most of the mucosal epithelial cells were removed and that the decellularized trachea had lower immunogenicity than the control group. The analysis of SEM revealed that the decellularized trachea retained the micro- and ultra-structural architectures of the trachea and that the matrices cross-linked with genipin were denser. The biocompatibility evaluation and in vivo implantation experiments showed that the decellularized trachea treated with the DEM had better biocompatibility than that treated with the TPM and that immunogenicity in the cross-linked tissues was lower than that in the uncross-linked tissues (p < 0.05). CONCLUSION: Compared with the trachea treated with the TPM, the rabbit trachea processed by the DEM had better biocompatibility and lower immunogenicity, and its structural and mechanical characteristics were effectively improved after the genipin treatment, which is suitable for engineering replacement tracheal tissue.
Epithelial Cells ; Methods ; Microscopy ; Rabbits ; Tissue Engineering ; Trachea

Stroma surrounding the tumor cells plays crucial roles for tumor progression. However, little is known about the factors that maintain the symbiosis between stroma and tumor cells. In this study, we found that the transcriptional regulator-signal transducer and activator of transcription 3 (Stat3) was frequently activated in cancer-associated fibroblasts (CAFs), which was a potent facilitator of tumor malignancy, and formed forward feedback loop with platelet-activating factor receptor (PAFR) both in CAFs and tumor cells. Importantly, PAFR/Stat3 axis connected intercellular signaling crosstalk between CAFs and cancer cells and drove mutual transcriptional programming of these two types of cells. Two central Stat3-related cytokine signaling molecules-interleukin 6 (IL-6) and IL-11 played the critical role in the process of PAFR/Stat3 axis-mediated communication between tumor and CAFs. Pharmacological inhibition of PAFR and Stat3 activities effectively reduced tumor progression using CAFs/tumor co-culture xenograft model. Our study reveals that PAFR/Stat3 axis enhances the interaction between tumor and its associated stroma and suggests that targeting this axis can be an effective therapeutic strategy against tumor malignancy.