Rapamycin Liposomes Combined with 5-Fluorouracil Inhibits Angiogenesis and Tumor Growth of APC (Min/+) Mice and AOM/DSS-Induced Colorectal Cancer Mice.

Background: Transgenic C57BL/6-APC(Min/+) spontaneous cancer mouse model and the Azoxymethane (AOM)/Dextran Sulfate Sodium (DSS) chemically induced orthotopic colorectal cancer mouse model represented distinct pathogenesis of colorectal cancers. Our previous study revealed that the combination of Rapamycin liposomes (Rapa/Lps) and 5-Fluorouracil (5-FU) has anti-colorectal cancer effects. However, the therapeutic efficacy of Rapa/Lps and 5-FU in other colorectal cancer mice models is yet to be thoroughly explored. The purpose of this study was to investigate the anti-tumor effect of Rapa/Lps combined with 5-FU in vivo and in vitro. Methods: In this study, we evaluated the effect of Rapa/Lps and 5-FU on APC (Min/+) mice and AOM/DSS-induced colorectal cancer mice. The small intestine, colorectum, serum, and plasma of mice in each group were collected following sacrifice to record the number of tumors. HE staining was utilized for observing pathological damage to intestine tissues. Tube formation assay, Transwell assay, wound healing assay, Western Blot were used to explore the anti-angiogenesis effect of drugs in HUVECs. Results: As expected, Rapa/Lps and 5-FU significantly suppressed tumor formation, decreased the number of tumors, and tumor load both in two mouse models, and had no influence on mouse weight. Mechanically, the anti-tumor effect of the drug also was associated in inhibiting angiogenesis and proliferation. Furthermore, we found that Rapa/Lps obviously inhibited HUVECs tube formation and migration. Conclusion: Altogether, we revealed the Rapa/Lps synergism with 5-FU decreased colon and small intestinal tumorigenesis in AOM/DSS-treated and APC (Min/+) mice, respectively, and correlated with anti-angiogenesis.

Myrothecol A, a new alkylresorcinol with cytotoxicity from Myrothecium sp.

A new alkylresorcinol, myrothecol A (1), along with two known ones (2 and 3), were isolated from a fungal strain Myrothecium sp. GY170016. Their structures were elucidated by extensive spectroscopic analysis. The absolute configuration of 1 was determined by electronic circular dichroism experiment. This is the first case of the presence of alkylresorcinols in genus Myrothecium. All the isolates were evaluated for their cytotoxic activities against human cancer cell line MCF-7 with IC50 values of 16.7, 13.2, 21.3 µM, respectively.

Delivery of Rapamycin by Liposomes Synergistically Enhances the Chemotherapy Effect of 5-Fluorouracil on Colorectal Cancer.

BACKGROUND: Rapamycin is a promising agent for treating tumors, but clinical applications of rapamycin are limited due to its poor water solubility and low bioavailability. This paper constructs a liposome delivery system for rapamycin to improve the effect in treating colorectal cancer. METHODS: We prepared the rapamycin liposomes using the ethanol injection method. The cellular uptake and biodistribution were detected by LC-MS and in vivo imaging system. MTT assay, transwell migration experiment, flow cytometry, and Western blot analysis evaluated the antitumor effect of rapamycin liposomes in vitro. Furthermore, HCT-116 tumor-bearing mice were used to assess the therapeutic efficacy of rapamycin liposomes in vivo. RESULTS: The prepared rapamycin liposomes had a particle size of 100±5.5 nm and with a narrow size distribution. In vitro cellular uptake experiments showed that the uptake of rapamycin liposomes by colorectal cells was higher than that of free rapamycin. Subsequently, in vivo imaging experiments also demonstrated that rapamycin liposomes exhibited higher tumor accumulation. Therefore, the ability of rapamycin liposomes to inhibit tumor proliferation, migration and to induce tumor apoptosis is superior to that of free rapamycin. We also demonstrated in vivo good antitumor efficacy of the rapamycin liposomes in HCT-116 xenograft mice. In addition, rapamycin liposomes and 5-FU can synergistically improve the efficacy of colorectal cancer via the Akt/mTOR and P53 pathways. CONCLUSION: Collectively, rapamycin liposomes are a potential treatment for colorectal cancer, as it not only improves rapamycin's antitumor effect but also synergistically enhances 5-FU's chemotherapy effect.

T-cell death-associated gene 8 accelerates atherosclerosis by promoting vascular smooth muscle cell proliferation and migration.

BACKGROUND AND AIMS: Atherosclerosis is a serious cardiovascular disease, featuring inflammation, abnormal proliferation and migration of vascular smooth muscle cells (VSMCs). During atherosclerosis, inflammation may cause low pH. T-cell death-associated gene 8 (Tdag8) is a proton-sensing receptor, however, the role of Tdag8 in VSMCs remains unknown. This study aimed to investigate the potential effects of Tdag8 in VSMCs during atherosclerosis. METHODS: We examined the expression of Tdag8 in an atherosclerotic model of high-fat-diet-fed ApoE-/- mice, while the role and mechanism of Tdag8 in phenotype transformation, proliferation and migration of VSMCs were investigated in a series of in vivo and in vitro experiments. RESULTS: We first found that Tdag8 expression at the mRNA and protein level was significantly increased in atherosclerotic ApoE-/- mice. Immunofluorescence staining showed that Tdag8 was primarily distributed in PCNA-positive VSMCs and the phenotype of VSMCs switching from contractile phenotype to synthetic phenotype. Additionally, the protein level of Tdag8 was upregulated in FBS-treated VSMCs. VSMCs proliferation and migration were inhibited by Tdag8 silencing and increased by Tdag8 overexpression. Further mechanistic studies showed that cAMP level was increased in Tdag8-overexpressing VSMCs and ApoE-/- mice. However, the PKA inhibitor H-89 reversed Tdag8-induced VSMC proliferation and migration. CONCLUSIONS: The results demonstrate that Tdag8 mediated phenotype transformation, proliferation and migration of VSMCs via the cAMP/PKA signaling pathway, thus partially contributing to atherosclerosis.

Nox1/4 dual inhibitor GKT137831 attenuates hypertensive cardiac remodelling associating with the inhibition of ADAM17-dependent proinflammatory cytokines-induced signalling pathways in the rats with abdominal artery constriction.

NADPH oxidases (Noxs) 1/4 dual inhibitor GKT137831 prevents hypertensive cardiac remodelling in angiotensin II-infused transgenic mice with cardiomyocyte-specific human Nox4 (c-hNo x 4 Tg); however, further research is still required to determine the beneficial role of GKT137831 in hypertensive cardiac remodelling in other types of hypertensive models because this hypertensive model is insufficient to mimic the complicated pathological mechanisms of hypertension. A disintegrin and metalloprotease 17 (ADAM17) promotes the shedding of tumour necrosis factor α (TNF-α), TNF-α receptor, interleukin 1 receptor-II and interleukin 6 (IL-6) receptor from cells, thereby mediating the signalling pathways induced by corresponding proinflammatory cytokines. This study aimed to determine whether GKT137831 prevents hypertensive cardiac remodelling and its mechanisms of action in the rats with abdominal artery coarctation (AAC). The rats subjected to AAC were orally given GKT137831 for a consecutive period of 28 days. Echocardiography and histological analysis were performed to evaluate cardiac remodelling; and immunohistochemistry and real-time PCR were used to detect the expression of proinflammatory cytokines. GKT137831 significantly suppressed hypertensive cardiac remodelling in AAC-induced hypertensive rats. Concurrently, Nox1/4 dual inhibitor GKT137831 reduced the protein and mRNA levels of proinflammatory cytokines interleukin 1ß (IL-1ß), IL-6, and TNF-α in the left ventricle of AAC-induced hypertensive rats. Moreover, the treatment with GKT137831 markedly diminished the protein and mRNA levels of ADAM17 in the left ventricle of AAC-induced hypertensive rats. In summary, Nox1/4 dual inhibitor GKT137831 protects against hypertensive cardiac remodelling in AAC-induced hypertensive rats, and the inhibition of ADAM17-dependent proinflammatory cytokines-induced signalling pathways are related to its beneficial effect on hypertensive cardiac remodelling.

HIV-infection resistance in PMBC-derived dendritic cells modified with recombinant virus.

This study aimed to identify the characteristics of recombinant-adenovirus-modified PBMC-derived dendritic cells and their resistance to HIV-1 infection by integrating the CCR5∆32, CCR5siRNA, HIV-1 pol and HIV-1 int genes into a recombinant adenovirus vector using the AdEasy system. Dendritic cells (DCs) were isolated from human PBMCs from blood of healthy donors. The expression of CCR5∆32, CCR5, CXCR4 and HIV-1 p24 in PBMCs or modified cells was measured by western blot, p24 expression in cell lysates was measured by ELISA, and HIV-1 entry was measured by ß-galactosidase assay. Furthermore, T-cell immunity induced by the recombinant adenovirus was measured by ELISPOT assay. After the cells were modified by Ad-R5∆32siRNA, the expression of CCR5∆32 increased, while the expression of CCR5 and CXCR4 decreased. There was no adverse effect of adenoviral gene transfer on DC development. CD83 expression on the surface of mature DCs did not change after gene transfer. The expression of p24 remained at low levels in modified cells when challenged by HIV-1. The modified cells showed resistance to HIV-1 infection. Results indicated that recombinant-adenovirus-modified cells demonstrated good resistance to HIV-1 infection. Modification of HSC-derived immune cells, such as DCs, may be a potent strategy to resist HIV-1 infection.

[Effect of Limax lyophilized powder on bronchial asthma].

OBJECTIVE: To study the effect of Limax lyophilized powder on bronchial asthma. METHODS: The allergic asthma model was established in guinea pigs by combined utilization of aluminum hydroxide and egg albumin to investigate the effect of Limax lyophilized powder on the bronchial flow and on the level of inflammator in bronchoalveolar lavage and serum. RESULTS: The mortality of asthma laboratory guinea pigs was reduced and the incubation period of asthma was extended significantly in Limax lyophilized powder groups. Its antiasthmatic effect was as efficient as the control drug (aminophylline). The leucocyte count was decreased in peripheral blood and the bronchoalveolar lavage fluid. The infiltration of pulmonary tissues eosinophil was also significantly reduced. Further more,the most efficient effects was showed in Limax lyophilized powder at the moderate dosage (63 mg/kg). The bronchial perfusion flow was increased and the level of IL-2 and IL-4 in blood serum and bronchoalveolar lavage fluid was decreased obviously in the aminophylline group and Limax lyophilized powder groups at moderate and high dosage. CONCLUSION: Limax lyophilized powder could inhibit bronchial asthma evidently.

[Mechanisms of foam cell formation in smooth muscle cell derived from bone marrow stem cells].

OBJECTIVE: To establish a model of smooth muscle cells differentiated from bone mesenchymal stem cells (BMSC-SMCs) in vitro and explore the relationship between scavenger receptors A (SR-A) and caveolin-1. METHODS: BMSCs were isolated from the femoral bone of SD rats by adherent culture. After treatment of the BMSC-SMCs with 80 mg/L ox-LDL for 72 h, Western blotting was performed to detect the expression of scavenger receptor SR-A, cell cholesterol transport protein ATP-binding cassette transporter Al (ABCA1) and caveolin-1. RESULTS: BMCS-SMCs became foam cells after treatment with ox-LDL. BMSC-SMC gave rise to more foam cell formation than VSMCs did. Western blotting showed that treatment with 80 mg/L ox-LDL for 72 h resulted in significantly increased expression of SR-A and significantly decreased expressions of ABCA1 and caveolin-1. CONCLUSIONS: Treatment of BMCS-SMCs with ox-LDL results in cholesterol ester accumulation in the cells to result in foam cells, the mechanism of which involves up-regulation of scavenger receptor SR-A expression and down-regulation of the reverse cholesterol transport protein ABCA1 and caveolin-1 expression.

[Effect of oxidative low-density lipoprotein on the proliferation of bone marrow stem cell- derived smooth muscle cells].

OBJECTIVE: To establish the model of bone mesenchymal stem cell-derived smooth muscle cells (BMSC-SMCs) and investigate the role of BMSC-SMCs in the development and progression of artherosclerosis. METHODS: BMSCs were isolated from the femoral bone of SD rats by adherent tissue culture method, and vascular smooth muscle cells (VSMCs) were obtained from the thoracic aorta. The differentiation of BMSCs into BMSC-SMCs was induced in the conditioned medium. The specific markers of BMSCs and BMSC-SMCs were identified by immunofluorescence (IF) staining. After treatment with 80 mg/L oxidative low-density lipoprotein (ox-LDL) for 72 h, the growth characteristics of BMSC-SMCs and VSMCs were observed. Flow cytometry was applied to analyze the cell cycle of BMSC-SMCs and VSMCs. RESULTS: BMCS-SMCs transformed into foam cells after treatment with ox-LDL, which was more obvious in comparison with VSMCs. The growth curve of BMSC-SMCs and VSMCs presented with an S-shape pattern with the cell doubling time of 20 and 32 h, which was reduced to 15 and 28 h after treatment with 80 mg/L ox-LDL, respectively. Flow cytometry showed that exposure to 80 mg/L ox-LDL significantly increased G(0)/G(1) and decreased S and G(2)/M phase cells in both BMSC-SMCs (P<0.01, n=3) and VSMCs (P<0.05, n=3) in comparison with the control cells. CONCLUSION: BMSC-SMC might be involved in the formation of fatty core and accelerate the development of atherosclerosis.

Curcumin inhibits cellular cholesterol accumulation by regulating SREBP-1/caveolin-1 signaling pathway in vascular smooth muscle cells.

AIM: To investigate the protective effect and the possible mechanism of curcumin on anti-atherosclerosis. METHODS: Morphological changes of atherosclerotic lesions taken from apoE knockout (apoE-/-) mice were determined by hematoxylin- eosin staining. Intracellular lipid droplets and lipid levels were assayed by oil red O staining and HPLC. The protein expression of caveolin-1 was quantified by Western blotting. Translocation and the expression of sterol response element-binding protein-1 (SREBP-1) were indirectly detected by an immunofluorescence analysis. RESULTS: The administration of 20 mg. kg(-1 ). d(-1 )curcumin to apoE-/- mice for 4 months induced a 50% reduction of atherosclerotic lesions and yielded a 5- fold increase in the caveolin-1 expression level as compared to the model group. Rat vascular smooth muscle cells (VSMC) pretreated with 50 mg/L ox-lipid density lipoprotein(ox-LDL) for 48 h increased cellular lipid contents, and stimulated SREBP-1 translocation, but decreased the caveolin-1 expression level. Lipid-loaded cells exposed to curcumin at various concentrations (12.5, 25, and 50 micromol/L) for different durations (0, 6, 12, 24, and 48 h) significantly diminished the number and area of cellular lipid droplets, total cholesterol, cholesterol ester, and free cholesterol accompanying the elevation of the caveolin-1 expression level (approximately 3-fold); the translocation of SREBP-1 from the cytoplasm to the nucleus was inhibited compared with the models. Lipid-loaded VSMC exposed to N-acetyl- Leu-Leu-norleucinal, a SREBP-1 protease inhibitor, showed increased nuclear translocation of SREBP-1, reduced caveolin-1 expression level, and upregulated cellular lipid levels. CONCLUSION: Curcumin inhibits ox-LDL-induced cholesterol accumulation in cultured VSMC through increasing the caveolin-1 expression via the inhibition of nuclear translocation of SREBP-1.

[Preparation and identification of monoclonal antibody against human thrombomodulin.].

To produce specific monoclonal antibody (McAb) against human thrombomodulin (hTM), the full-length hTM cDNA-expressing plasmid pThr402 was transfected into CHO cells by Lipofectamine 2000 reagent. The hTM-expressing CHO cells, which was confirmed by flow cytometry and Western blot, were obtained by G418 selection. Then the McAb against hTM was prepared with classic hybridoma technique. A cell line of CHO-TM5 with high level of hTM was used to immunize female Balb/c mice 3 times at an interval of 4 weeks. On the third day after the third immunization, mice were sacrificed and spleen cells were harvested to prepare hybridoma cells with SP2/0 cells at the ratio of 10 to 1. Hybridoma cells were then cultured at 96-well plates for screening. Cellular enzyme-linked immunoabsorbent assay (CELISA) was applied twice. The first CELISA was done with polythene ELISA plate with a monolayer of CHO-TM5 cells. The positive clones from the first screen were then selected by reacting with similar screening ELISA plate but with CHO cell monolayer instead. Only clones that were positive for the first screening and negative for the second screening were kept, and called as CHO-TM5(+)CHO(-) hybridoma cells. Balb/c mice were intraperitoneally injected with the selected hybridoma cells. Ascites were collected and monoclonal antibodies were purified using FPLC, and its Ig class, subclass, and titer were then determined respectively. The specificity of the yielded McAb was identified with CELISA, flow cytometry, ABC immunohistochemistry and immunoblotting. One line of hybridoma cells with high expression of specific McAb against hTM, NH-1, was obtained. The Ig subclass of the McAb was IgG1 and the titer of ascitic McAb was 1x10(-6). Flow cytometry, CELISA and Western blot assays demonstrated that McAb NH-1 could specifically recognize hTM expressed in CHO-TM5 cells and human umbilical vascular endothelial cells. Meanwhile, the tissue specificity of antigen recognized by McAb NH-1 was identified by immunohistochemical ABC staining. NH-1 can specifically recognize the natural hTM expressed mainly in vascular endothelial cells, which will potentially be useful for investigation of the functions and clinic values of hTM.

High density lipoprotein 3 inhibits oxidized low density lipoprotein-induced apoptosis via promoting cholesterol efflux in RAW264.7 cells.

AIM: To investigate the protective effect of high density lipoprotein 3 (HDL3) on oxidized low density lipoprotein (ox-LDL)-induced apoptosis in RAW264.7 cells. METHODS: RAW264.7 cells were exposed to 50 mg/L ox-LDL for various durations up to 48 h, and apoptosis was detected using Hoechst 33258 staining and flow cytometric analysis. Total cholesterol levels were detected by high performance liquid chromatography, cholesterol efflux was determined by Tritium labeling, and the cellular lipid droplets were assayed by oil red O staining. RESULTS: Treatment with 50 mg/L ox-LDL for 12, 24, and 48 h increased the apoptotic rate of RAW264.7 cells in a time-dependent manner. The peak apoptotic rate (47.7%) was observed after 48 h incubation. HDL3 at various concentrations (50 mg/L, 100 mg/L, and 200 mg/L) inhibited the ox-LDL (50 mg/L for 48 h)-mediated apoptosis that was accompanied by an increased rate of intracellular cholesterol efflux, and decreased total cholesterol levels in cells in a concentration-dependent manner. Blockage of cholesterol efflux by brefeldin decreased the protective effect of HDL3 on ox-LDL-induced apoptosis. Increase of the cholesterol efflux effected by another cholesterol acceptor,beta-cyclodextrin, led to a dramatic decrease in the apoptotic rate of cells. CONCLUSION: HDL3 antagonizes ox-LDL-induced apoptosis in RAW264.7 cells, through reducing the accumulation of toxic cholesterol.

17beta-estradiol potentiates ischemia-reperfusion injury in diabetic ovariectomized female rats.

UNLABELLED: To investigate the effect of 17beta-estradiol (E2) on ischemia-reperfusion (I/R) injury in diabetic ovariectomized female rats. Streptozotocin(STZ)-induced diabetic female rats received E2 treatment for 2 weeks after ovariectomy (OVX). A period of 90 min of temporary middle cerebral artery occlusion (tMCAO) was used for the study. Rats were evaluated for physiological data including plasma glucose, E2, MAP, PaCO2 and PaO2 before and after tMCAO. P-selectin expression, myeloperoxidase (MPO) enzyme activity and the cerebral infarct volume were analyzed. RESULTS: The infarct volume in the E2-treated OVX rats is bigger than that in intact and OVX groups. However, there is not a significant different area of cerebral infarct between diabetic OVX and intact rats. Significant upregulation of P-selectin expression and MPO activity of the ischemia-reperfusion hemisphere were observed in E2 + OVX, intact and OVX groups at 8, 24, 72 h in time manner after tMCAO compared with that of the contralateral hemisphere of cerebral ischemia-reperfusion. Both P-selectin expression and MPO activity in the E2 + OVX and intact rats are significantly higher than that in the untreated OVX rats. Chronic estrogen replacement therapy (ERT) potentiates the I/R injury in diabetes female rats. This may be related to the increased expression of P-selectin and MPO activity.