Experimental study on co-culture of early embryo and cancer cells in vitro / 生物医学工程学杂志

The co-culture system of early embryos and cancer cells is an important means to observe the biological behavior changes of embryos and cancer cells in vitro. In this study, we co-cultured the 3.5 dpc mouse embryo with malignant tumor cells, investigated the development of blastocyst by observing the hatchment, attachment and outgrowth, observed the biological behavior changes of cancer cells in the embryonic circumstances, and detected the proliferation and apoptosis of cancer cells. Compared with the control, the embryos developed normally in the tumor environments, and the rate of hatchment, attachment and outgrowth increased significantly (P<0.05). However, there was no significant change of cancer cells in morphology, proliferation and apoptosis in the co-culture system (P>0.05). Under the co-culture system, the early embryo developed normally, and the cancer cells also grew well. There may be similarities between the embryos and cancer cell's choice for living. Moreover, the growth of embryos could be promoted by cancer cells in the co-culture system. This might be related to the similarities of gene expression, growth factors and signal transduction mechanisms between embryos and cancer cells.

A potential role for the bone marrow mesenchymal stem cell in the pathogenesis of osteoporosis by ovariectomy in rat / 生物医学工程学杂志

The purpose of this paper is to investigate the osteogenesis and adipogenesis in bone marrow mesenchymal stem cells (MSCs) isolated from normal rats and osteoporotic rats by ovariectomy. Osteoporotic animal model was established in 3 month-old and 6 month-old female Sprague-Dawley (SD) rats by ovariectomy. Animal experiments were divided into 4 groups: 1) control-3 group; 2) ovx-3 group; 3) control-6 group and 4) ovx-6 group. MSCs were isolated by means of the density-gradient centrifugation method from each group, respectively. Colony-forming unit-fibroblast (CFU-Fs ) number, CFU-Fs size distribution and cell density in CFU-Fs of primary passage MSCs were measured at the inverted phase contrast microscope. The cell cycle and proliferation index (PI) as well as apoptosis idex (AI) of MSCs were studied by (FCM). After osteogenic induction (OSI), calcium nodes of MSCs were marked by alizarin red staining (ARS); The expression level of alkaline phosphatase(ALP) was detected by dynamics method with substrate of phosphoric acid para-Nitro benzene and the content of osteocalcin (OCN) was detected with the isotope labelling method. After adipogenic induction (ADI), lipid droplet in MSCs were detected by oil red O staining and the mRNA level of lipoprotein lipase (LPL) was measured by RT-PCR. The results showed that CFU-Fs and PI are obviously decresed and AI are increased of MSCs in OVX-3 and OVX-6 groups (P<0.05). The secretory volume of ALP and BGP of MSCs and the content of calcium nods of MSCs are lower in OVX-3 and OVX-6 groups than that in control-3 and control-6 groups after osteogenic induction (P<0.05). The number of lipid droplet and the expression level of LPL mRNA are higher in OVX-3 and OVX-6 groups than that in control-3 and control-6 (P<0.05). The result in our study suggested that depress of osteogenesis and the up-regulation of adipogenesis of MSCs in osteoporotic rats by ovariectomy may be relate close to the pathogenesis of osteoporosis.

The effect of mechanical stimulation on the expression of alpha 2, beta 1, beta 3 integrins and the proliferation, synthetic function in rat osteoblasts / 生物医学工程学杂志

The purpose of this paper is to investigate the probable molecular mechanism in mechano-transduction of the regulation of integrins and the effects of cyclic biaxial mechanical strain on proliferation and synthetic function in the osteoblasts isolated from 3-month-old female Sprague-Dawley (SD) rats. The osteoblasts were cultured in F-12 medium contained with 10% fetal bovine serum(FBS) and grown to subconfluency in Flexercell type I dishes in a humidified incubator with 5% CO2 and 95% air at 37 degrees C. Mechanical strains were applied to the cells for periods of 30 min, 2, 4 and 8 hours every day, lasting 2 days. The amplitude of mechanical strain applied to the cells were 400, 1,000 and 4,000 mu strain respectively, at a frequency of one hertz(1 Hz). Unstrained cells were used as control. The expression of integrins alpha 2, beta 1, beta 3 on the membrane of osteoblasts and proliferation activity of osteoblasts were studied with Flow Cytometry(FCM). The content of osteocalcin, carboxyterminal propeptide of type-I procollage(PICP), total protein secreted by osteoblastes were detected with the isotope labelling method. The results showed that there are actual expressions of integrins alpha 2, beta 1, beta 3 on the membrane of osteoblasts without mechanical strain and that the expression of integrins beta 1 is highest. The mechanical strain increased the expression of integrins alpha 2, beta 1, beta 3 on the membrane of osteoblasts, but the strain-related up-regulation of expression of integrins alpha 2, beta 1, beta 3 are different in various amplitude and different duration of mechanical stains. The up-regulation of expression of integrins beta 3 is most sensitive to mechanical strain. The up-regulation of expression of integrins alpha 2, beta 1, beta 3 is higher at 4,000 mu strain than at 400, 1,000 mu strain. The mechanical strain can elevate the proliferation activity and the synthetic function of osteoblast at 400, 1,000 mu strain. However, the mechanical strain increased significant the proliferation in the osteoblasts and suppressed obviously the synthetic function in the osteoblasts. In the present study, the reaction of the osteoblasts in 3 month-old rat to the mechanical stimulation suggested that 1) expressions of integrins alpha 2, beta 1, beta 3 were increased in a amplitude of strain-dependent manner; 2) the changes of expression of integrins alpha 2, beta 1, beta 3 relate close to the changes of the proliferation and synthetic function of the osteoblasts. Low amplitude of strain can increase the proliferation and the synthetic function of the osteoblasts along with up-regulation of expression of integrins alpha 2, beta 1, beta 3; while higher amplitude of strain elevated significantly the proliferation of osteoblasts and suppressed obviously the synthetic function of the osteoblasts along with up-regulation of expression of integrins alpha 2, beta 1, beta 3. The amplitude of 4,000 mu strain is an optimal amplitude as stimulus for up-regulation of expression of integrins alpha 2, beta 1, beta 3 on the membrane of osteoblasts and increase the proliferation activity, but decrease the synthetic function of osteoblasts in the present study. Accordingly it indicates that integrins have a important role in regulation of signal transduction pathway in osteoblasts as a result of mechanical strain.

Effects of shear stress and lysophosphatidylcholine on adhesion molecules expression of endothelial cells / 生物医学工程学杂志

Extensive monocyte recruitment is an early phenomenon associated with the development of atherosclerotic lesion. Although the molecular mechanisms are not completely understood, monocyte recruitment into these early lesions may involve changes in endothelial adhesion for monocyte, in which adhesion molecules expressed by endothelial cell play an active role. In vivo, the function of endothelial cells is not only affected by the chemical factors, but also by the mechanical factors. The purpose of this article was to investigate the induction of adhesion molecules expression by synergistic effects of Lysophosphatidylcholine (Lyso-PC) and shear stress in cultured human umbilical vein endothelial cells (HUVEC). The surface expression of ICAM-1, VCAM-1 and E-selectin on HUVEC induced by Lyso-PC(30 micrograms/ml) and shear stress(2.23, 4.20 dyne/cm2) were analyzed using flow cytometry. The results showed that: Compared with what were simultaneously exposed to shear stress and Lyso-PC, activating the cells with Lyso-PC prior to shear stress, or pre-conditioning the cells exposed shear stress prior to Lyso-PC incubation, a significantly higher expression of ICAM-1 and VCAM-1(P < 0.05) was resulted. HUVEC were exposed to shear stress and Lyso-PC at the same time or treated with each agonist alone, E-selectin expression was not significantly different from the control group. However, a sequential action of the two stimuli significantly increased E-selectin expression(P < 0.05). We concluded that: a sequential action of the shear stress and Lyso-PC induced an even greater expression of ICAM-1 and VCAM-1, thus it could be understood that the flows-hear stress in combination with endothelial activated by chemical factors may increase the ability of endothelial cells to recruit leukocytes even under the mechanical environment unfavorable for cell adhesion.

The effect of low-dose aprotinin on the expression of neutrophil CD_(11b)/CD_(18) in open heart surgery / 中华麻醉学杂志

Objective To investigate the inhibition of low-dose aprotinin on systematic inflammatory response during cardiopulmonary bypass. Methods Twenty-eight ASA Ⅱ-Ⅲ patients(male 13, female 15) undergoing valve replacement were studied. The age ranged from 27 to 55 years and body weight from 37 to 70 kg. CPB time ranged from 66 to 218 mm and aortic cross clamping time from 30 to 140 min . The patients were divided into two groups: control group(n=14) and aprotinin group(n = 14) Premedication included intramuscular phenobarbital sodium 0.1 g and scopolamine 0.3 mg. Anesthesia was induced with intravenous midazolam 0. lmg/kg, fentanyl 20-30?g/kg and vecuronium 0. 1-0. 12mg/kg, and maintained with intermittent bolus injection of fentanyl and vecuronium supplemented with isoflurane inhalation. In aprotinin group aprotinin 1?106KIU was infused after induction of anesthesia until thoracotomy, after thoracotomy aprotinin was infused at a rate of 2.5? 106 KIU/h and aprotinin 2. 5 ?106KIU was added to the prime fluid as suggested by Levy. Blood samples were obtained before anesthesia, before CPB and 1h and 24h after CPB for determination of CD11b and CD18 expression on the surface of neutrophil by immunofluoresence flow cytometry. Results The expression of CD11b or CD18 and CPB time were positively correlated(?= 0.644, 0.538, P0.05). 1 h after CPB CD11b/ CD18 expression increased significantly in the control group and was significantly higher than that in the aprotinin group, but at 24h after CPB only CD11b expression in control group was significantly higher than that in aprotinin group. In aprotinin group there was no significant difference in CD11b/CD18 expression between the four intervals.Conclusions CPB-induced systematic inflammatory response may be positively correlated with CPB time. Low dose aprotinin can inhibit the increase in CD11b/CD18 expression after CPB.