THBS4 Promotes the Metastasis of Hepatocellular Carcinoma Cells by Inducing M2 Polarization of Tumor-associated Macrophages / 中国生物化学与分子生物学报

Thrombospondin 4 (THBS4), a member of the THBS family, is a protein secreted by the extracellular matrix and is involved in regulating various physiological processes, such as cell proliferation, adhesion and angiogenesis. Recent studies have shown that the inflammation stimulates THBS4 production and induces the adhesion and accumulation of macrophages. Our previous study confirmed that THBS4 acts as an oncogene in hepatocellular carcinoma (HCC), the effect of THBS4 on the immune microenvironment of HCC remains unclear. This study aims to analyze the role of THBS4 in promoting the metastasis of HCC cells by inducing M2-type polarization of tumor-associated macrophages. We simulate the tumor microenvironment through HCC conditioned medium (HCM) and found that the expression of THBS4 in macrophages increased in a time-dependent manner under the action of HCM (P<0.05); THBS4 knockdown promotes the expression of M1 macrophages markers IL-1β and CD86 (P<0.01), while the expression of M2-type markers IL-10 and CD206 were decreased (P<0.01). Transwell co-culture assay was used to further detect the effect of THBS4-induced M2-type macrophages on HCC metastasis. Results from co-culture of THBS4-downregulated M2 macrophages with HepG2 cells showed that THBS4-downregulated M2-TAMs significantly inhibited the invasion and migration ability of HepG2 cells (all P < 0.01). In conclusion, the tumor microenvironment promotes the expression of THBS4 in macrophages, and THBS4 may promote the invasion and metastasis of HCC cells by inducing M2-type polarization of macrophages. This study provides some new experimental basis for exploring the establishment of THBS4-induced HCC immune microenvironment.

Effect of Thbs4 gene editing BMSCs transplantation on VEGF and Ang-1 in diabetic hind limb ischemia rats and related mechanism / 国际生物医学工程杂志

Objective To investigate the effects and the mechanism of thrombospondin 4 (Thbs4) gene-edited bone marrow mesenchymal stem cells (BMSCs) transplantation on vascular endothelial growth factor (VEGF) and angiopoietin-1 (Ang-1) in diabetic rats with hind limb ischemia. Methods Thirty Sprague-Dawley rats were randomly divided into the model group, BMSCs treatment group and Thbs4-BMSCs treatment group on average. After constructing the typeⅡdiabetic rat model with hind limb ischemia, 100μl normal saline, BMSCs suspension and Thbs4-BMSCs suspension (cell number: 2×106) were locally injected into the ischemic injury area of rats for the model group, BMSCs group and Thbs4-BMSCs group, respectively. The rats were sacrificed on the 14th day after stem cell transplantation, and the muscle tissues near the ischemic area were collected. The relative expression of VEGF and p-Smad2/3 protein was detected by Western Blot. The Ang-1 protein expression was detected by immunofluorescence staining. The levels of related genes were detected by qRT-PCR, and the von Willebrand Factor (vWF) protein expression was detected by immunohistochemistry staining. Results The relative expression levels of VEGF, Ang-1 and vWF protein in the Thbs4-BMSCs group were significantly higher than those in the model group and BMSCs group (VEGF protein:P<0.01 and P<0.05). The mRNA expression of VEGF and Ang-1 were significantly up-regulated, the differences were statistically significant(VEGF mRNA:all P<0.01;Ang-1:P<0.01 and P<0.05). The expression of p-Smad2/3 protein in the Thbs4-BMSCs group was significantly higher than that in the model group and the BMSCs treatment group (all P<0.01). The expression of p-Smad2/3 protein was significantly decreased after the addition of p-Smad2/3 pathway inhibitor, the differences were statistically significant (P<0.05). Conclusions Thbs4-BMSCs transplantation can effectively promote angiogenesis in diabetic rats with hind limb ischemia, and the effect of angiogenesis may be related to the activation of Smad2/3 signaling pathway.

Characterization of Tendon-Specific Markers in Various Human Tissues, Tenocytes and Mesenchymal Stem Cells

BACKGROUND: Unlike bone, cartilage, or muscle, tendon-specific markers are not well established. The purpose of the study was to investigate expression pattern and level of 6 well-known tendon-specific markers, in various human musculoskeletal tissues, tenocytes, and mesenchymal stem cells (MSCs). METHODS: Musculoskeletal tissue samples of tendon, bone, cartilage, nerve, muscle, and fat were obtained from patients undergoing orthopedic surgery. Tenocytes, MSCs from bone marrow, adipose tissue, and umbilical cord were isolated from each tissue and cultured. Six tendon-specific markers, scleraxis (Scx), tenomodulin (TNMD), thrombospondin-4 (TSP-4), tenascin-C (TNC), type I collagen (Col I), and type III collagen (Col III) were investigated in tendon tissue, tenocytes, and MSCs. RESULTS: mRNA levels of 6 tendon-specific markers were significantly higher in tendon tissue that in other connective tissues levels of Scx, TNMD, TSP-4, and Col III immediately decreased after plating tenocytes in culture dishes whereas those of TNC and Col I did not. In comparison with tendon tissue, mRNA levels pattern of Scx, TNMD, and TSP-4 in tenocytes were significantly higher than that in MSCs, but lower than in tendon tissue whereas expression pattern of TNC, Col I and III showed different pattern with each other. CONCLUSION: This study demonstrated that 6 commonly used tendon-specific markers were mainly expressed in tendon tissue, but that expression level and pattern of the tendon-specific markers with respect to kinds of tissues, culture duration of tenocytes and sources of MSCs.

Clinical significance of thrombospondin 4 expression in gastric carcinoma / 解剖学报

Objective The aim of this study was to measure quantitatively the TSP-4 mRNA expression and its significance in gastric carcinoma was evaluated by correlating its expression with clinicopathological features, microvessel density(MVD) and MMP-9.Methods Eighty-two patients with gastric carcinoma were recruited in this study. TSP-4 mRNA expression in gastric carcinoma and adjacent tissue was detected by real-time PCR. CD34 and MMP-9 protein expression were examined by immunohistochemistry. MVD was determined according to CD34-positive tubular structures. Results The expression level of TSP-4mRNA in gastric carcinoma was obviously higher than those of adjacent tissue(P=0.03) and it was associated with tumor size, histological type, lymph node metastasis, MVD and MMP-9(P=0.002, P=0.031, P=0.014,r＝0.67 P<0.01, P=0.008),but not sex, age and depth of invasion. (P=0.53,P=0.57,P=0.15).Conclusion TSP-4 may play an important role in occurrence and progression of gastric carcinoma and that the effect of TSP-4 on tumor growth and metastasis may be exerted through regulation of angiogenesis and MMP-9 expression in gastric carcinoma.