Structural analysis and anti-cancer activity of low-molecular-weight chondroitin sulfate from hybrid sturgeon cartilage.

Low-molecular-weight chondroitin sulfate (CS) has attracted widespread attention due to its better bioavailability and bioactivity than native CS. In this study, a low-molecular-weight CS (named SCS-F2) was prepared from hybrid sturgeon (Acipenser schrenckii × Huso dauricus) cartilage by enzymatic depolymerization with high in vitro absorption and anti-cancer activity. The structure of SCS-F2 was characterized and the in vivo biodistribution and colorectal cancer prevention effect was investigated. The results revealed that SCS-F2 consisted of 48.84% ΔDi-6S [GlcUAß1-3GalNAc(6S)], 32.11% ΔDi-4S [GlcUAß1-3GalNAc(4S)], 16.05% ΔDi-2S,6S [GlcUA(2S)ß1-3GalNAc(6S)] and 3.0% ΔDi-0S [GlcUAß1-3GalNAc]. Animal study showed that the SCS-F2 could be effectively absorbed and delivered to the tumor site and significantly prevented the growth of HT-29 xenograft by inhibiting cell proliferation and inducing apoptosis without showing any negative effect to normal tissues. Therefore, SCS-F2 could be developed as a potential nutraceutical to protect against colorectal cancer.

Mesenchymal stem cell-derived microvesicles alleviate pulmonary arterial hypertension by regulating renin-angiotensin system.

In recent years, microvesicles (MVs) derived from mesenchymal stem cells (MSCs) have been proved to be able to improve the outcome of pulmonary arterial hypertension (PAH) in many respects, but the underlying mechanisms of it still remain unclear. Because the renin-angiotensin system (RAS) has been found to be closely related to PAH, the present study was designed to investigate whether the effect of MSC-derived MVs on PAH was correlated with RAS. MVs were isolated and purified from bone marrow MSCs. PAH rat models were established by a single intraperitoneal injection of 1% monocrotaline (MCT, 50 mg/Kg). In vivo study, after 3 weeks of MCT exposure, Nor group and PAH group were injected with 0.5 mL saline every 2 days through tail vein, whereas MVs group was injected with 0.5 mL saline containing 30µg MVs and A-779 + MVs group injected with 0.5 mL saline containing 120µg A-779 and 30µg MVs until 5 weeks of MCT exposure. Whereafter all the groups were analyzed for hemodynamic evaluation, right ventricular hypertrophy index, pulmonary vessel wall thickness index and pulmonary vessel lumen area index, the inflammation score, the collagen fiber volume fraction, the levels of Ang-(1-7) and Ang-Ⅱin plasma and lung tissue, and the mRNA levels of ACE2 and ACE in the lung tissue. MVs derived from MSCs relieved the pulmonary artery pressure, right ventricular hypertrophy index, pulmonary vessel wall thickness index, pulmonary vessel lumen area index, the inflammation score, and the collagen fiber volume fraction. Moreover, in MVs group, ACE2 mRNA in the lung tissues and plasma levels of Ang-(1-7) were both upregulated compared with PAH group. On the contrary, ACE and Ang-II were decreased compared with PAH group. However, the enhanced protective effects observed in MVs group were diminished by the use of A-779, an inhibitor of Mas receptor in ACE2-Ang-(1-7)-Mas axis. MVs derived from bone marrow MSCs can exert beneficial effects against MCT-induced PAH in vivo, meanwhile shifting the balance from ACE-Ang-II-AT1R axis toward the ACE2-Ang-(1-7)-Mas axis, which might be one of the possible therapeutic mechanisms for MVs subcellular treatment.

Proangiogenic compositions of microvesicles derived from human umbilical cord mesenchymal stem cells.

INTRODUCTION & OBJECTIVE: Microvesicles (MVs) derived from mesenchymal stem cells (MSCs) have been shown to promote angiogenesis. This study was aimed to shed a light on the mechanisms by analyzing the angiogenesis-promoting compositions of MSC-MVs. Also we try to figure out the impact of hypoxia on angiogenesis. METHODS: MVs were isolated from the culture supernatants of MSCs under hypoxia/normoxia and serum-deprivation condition. The morphological features of MVs were revealed by an electron microscope and the origin of the MVs was identified by a bead-bound assay. An antibody array was used to analyze the expression of angiogenic cytokines from MVs and the parent MSCs as well. The major candidate factors were screened and the results were validated by immune blotting. RESULTS: MSC-MVs were around 80 nm in diameter. They expressed CD29, CD44, and CD73, but not CD31 and CD45. Antibody array showed that both MSCs and MVs expressed many angiogenesis-promoting biomolecules, including interleukin-6 (IL-6), basic fibroblast growth factors (bFGF), and recptor of urokinase-type plasminogen activator (UPAR). MSC-MVs contained angiogenin, vascular endothelial growth factor (VEGF), monocyte chemotactic protein-1 (MCP-1) and the receptor-2 for vascular endothelial growth factor at higher levels than the parent MSCs. Under hypoxic condition most cytokines were expressed in greater quantity than normoxic in MSCs while in MVs there was no significant difference between hypoxic and normoxic conditions except UPAR, Angiogenin, VEGF, IGF, Tie-2/TEK, and IL-6 which were higher in MVs under hypoxic conditions than those in normoxic condition. CONCLUSION: Upon serum-deprivation condition, MSCs could secrete MVs that contain a variety of factors contributing to their angiogenesis-promoting function. And among them, Angiogenin, VEGF, MCP-1, VEGF R2 might be of greater importance than the other cytokines. Also UPAR, Angiogenin, VEGF, IGF, Tie-2/TEK, IL-6 might be responsible for hypoxia-augmented proangiogenic effects of MVs.

Therapeutic effects of mesenchymal stem cell-derived microvesicles on pulmonary arterial hypertension in rats.

AIM: Microvesicles (MVs) are nanoscale membrane fragments released from virtually all cell types upon activation or apoptosis, and may contribute to the beneficial effects of stem cell therapy. In this study, we investigated the therapeutic effects of mesenchymal stem cell (MSC) derived MVs (MSC-MVs) on pulmonary artery hypertension (PAH) in rats. METHODS: MSC-MVs were isolated from rat bone marrow MSCs that were cultured in a serum-free conditioned medium. Transmission electron microscopy (TEM), flow cytometry and nanoparticle tracking analysis (NTA) were used to characterize the MVs. Adult SD rats were injected with monocrotaline (50 mg/kg, sc) to induce PAH. Three weeks later, the rats were intravenously injected with MSCs, MSC-MVs or saline for 2 weeks. At the end of treatments, the hemodynamic parameters and pathological right ventricular and pulmonary arterial remodeling were analyzed in each group. RESULTS: The MSC-MVs showed general morphologic characteristics of MVs and expressed annexin V and CD29 markers under TEM, and their size ranged from 40 to 300 nm. Intravenous injection of MSC-MVs or MSCs significantly ameliorated the mean pulmonary artery pressure (mPAP) and mean right ventricle pressure (mRVP) in PAH rats. Furthermore, intravenous injection of MSC-MVs or MSCs significantly decreased the right ventricle (RV) hypertrophy and pulmonary arteriole area index (AI) and thickness index (TI) in PAH rats. CONCLUSION: Intravenous injection of MSC-MVs or MSCs produces similar beneficial effects for treating PAH, and our results provide a basis for cell-free approach in stem cell therapy.

Transfer of human hepatocyte growth factor reduces inflammation and prevents pulmonary arterial remodeling in monocrotaline-induced.

Inflammation and endothelial dysfunction contribute to the pathogenesis and development of pulmonary arterial hypertension (PAH). This study was to investigate the therapeutic effect of human hepatocyte growth factor (HGF) gene transfer on monocrotaline (MCT) induced PAH rat models. PAH was induced by injecting MCT for 4 weeks. The rats were randomly assigned to phosphate buffered saline control group, MCT group, and HGF treatment group. After 2 weeks of induction, measures of mean pulmonary artery pressure (mPAP), weight ratio of the RV to the LV plus septum, percent wall thickness index (TI) and area index (AI) were significantly increased in MCT-group and HGF treatment-group compared with those in control group (P < 0.05). Those measurements in MCT-group were significantly higher than those in HGF treatment-group (P < 0.05). IL-6 significantly decreased in HGF treatment-group compared with MCT-group, but higher than that of control group (all P < 0.05). IL-10 in HGF treatment-group significantly increased compared with MCT-group, but lower than that of control group (all P < 0.05). Endothelial microparticles (EMP) started to decrease in the HGF treatment-group 3 days after treatment and was most significant after 1 and 2 weeks of treatment (all P < 0.05). Our results showed that transfer of human HGF may attenuate the inflammatory cell infiltrate, reduce the expression of inflammatory factors, and those effects are possibly due to the inhibition of EMP production which may decrease pulmonary vascular wall damage in PAH.