Differentiation of human umbilical cord-derived mesenchymal stem cells into annulus fibrosus-like cells by co-culture / 临床与实验病理学杂志

Purpose To induce the differentiation of hu-man umbilical cord mesenchymal stem cells ( HUCMSCs) into annulus fibrosus (AF) cells by in vitro co-culture technique and to investigate the morphological and histological changes of HUCMSCs after co-culture. Methods HUCMSCs and AF cells were isolated from the normal neonatal umbilical cord and New Zealand white rabbit. Transwell six-well plates were used for co-culture with the cells seeded at the ratio of 1 ∶ 1, HUCMSCs cultured alone served as controls. After two weeks of co-culture, morphological changes were observed by inverted microscope. Real-time PCR was used to detect the expression of typeⅠcolla-gen, aggrecan and SOX-9 gene in HUCMSCs. Immunocyto-chemical staining and toluidine blue staining were used to detect the synthesis of cell matrix such as type Ⅰ collagen and aggre- can. Results The morphology of HUCMSCs in control group was long-fusiform, the morphology of HUCMSCs in co-culture gradually became short-fusiform or polygonal, and began to ap-pear synapse, showing the morphological features of AF-like cells. Real-time PCR results showed that typeⅠcollagen, aggre-can and SOX-9 mRNA were significantly increased in the co-cul-ture group (P＜0. 05). Immunocytochemical staining and tolui-dine blue staining showed that type I collagen and aggrecan were positive, respectively. Conclusion In vitro co-culture technol-ogy can induce HUCMSCs to differentiate into AF-like cells, which is expected to provide a new kind of seed cells for the bio-logical treatment of degenerative disc disease.

Production of specific IgY Helicobacter pylori recombinant OipA protein and assessment of its inhibitory effects towards attachment of H. pylori to AGS cell line

PURPOSE: The common triple therapy for Helicobacter pylori is challenged by the increasing cases of antibiotic resistant infections, raising the need to explore alternative therapies. Oral administration of egg yolk immunoglobulin Y (IgY) has been previously reported as a means of passive immunization therapy for H. pylori infections. In this work, we investigated the inhibitory effect of IgY on the attachment of H. pylori to AGS cell line. MATERIALS AND METHODS: Recombinant OipA was prepared. Hens were immunized with recombinant protein three times. IgY was purified from egg yolks of immunized hens using polyethylene glycol precipitation method. The inhibitory effect of the specific immunoglobulin was evaluated in AGS cell line infected with H. pylori. RESULTS: The presence of recombinant OipA (30 kD) was confirmed via sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Immunization of hens was confirmed using enzyme-linked immunosorbent assay. The purified IgY from egg yolks were assessed using SDS-PAGE and confirmed by western blot. CONCLUSION: The results showed that IgY-OipA had inhibitory effect on attachment of H. pylori to AGS cell line and may be utilized as a therapeutic or prophylaxis material.

Hypoxia effects on the chondrogenic differentiation of three-dimensional co-cultured adipose-derived stem cells and articular chondrocytes / 中国组织工程研究

BACKGROUND:Many in vivo and in vitro experiments indicate that hypoxic co-cultures promote stem cells differentiate into chondrocytes. OBJECTIVE:To evaluate the influence of hypoxia on the chondrogenic differentiation of three-dimensional co-cultured adipose-derived stem cells and articular chondrocytes. METHODS:Adipose-derived stem cells and articular chondrocytes were mixed at the ratio of 3:1, then the mixed cells were seeded onto poly(lactic-co-glycolic acid)-gelatin scaffold at the ultimate concentration of 5.0×1010/L. The cells were cultured in normoxia (20%O 2 ) and hypoxic (5%O 2 ) conditions for 6 weeks. After culture, hematoxylin and eosin staining was performed for histological structure analysis, and alcian blue staining was used to evaluate glycosaminoglycan synthesis. Type II col agen expression was detected by immunohistochemistry staining. The content of DNA, glycosaminoglycan and hydroxyproline in the scaffold-cellcomplex was measured. RESULTS AND CONCLUSION:In the hypoxia group, hematoxylin-eosin staining showed the formation of massive cells and extracellular matrix;alcian blue staining showed massive glycosaminoglycan formation;immunohistochemistry staining detected strongly positive expression of col agen type II, the content of DNA, glycosaminoglycan and hydroxyproline was higher than the normoxia group. Hypoxia promotes in vitro chondrogenic differentiation of co-cultured adipose-derived stem cells and articular chondrocytes. .

Establishment of in vitro co-culture system for embryonic rat spinal motoneurons and C2C12 myotubes / 第二军医大学学报

Objective To identify the conditions for co-culturing embryonic rat spinal motoneurons and C2C12 myotubes, establish a stable co-culture system, and to form functional neuromuscular junction in vitro. Methods The C2C12 myoblasts were cultured to 60%-70% confluence and then were induced by differentiation medium. The embryonic spinal cord anterior horn motor neurons were obtained from 15-16 d pregnant SD rats, and were implanted in the myotubes after differentiating for 5 days; the products were co-cultured in the basic serum-free culture medium Neurobasal+2% B27. The neuronal morphology and projection length at each stage, myotubemorphological and contraction characteristics, and formation of the neuromuscular junction were observed under an inverted microscope. The crbungarotoxin (crBTX), which can specifically bind to acetylcholine receptor (AChR) of the postsynaptic membrane, was examined by immunofluorescence technique and the muscle contraction in the co-culture system was recorded by screen recording technology. Results Both the primal spinal motoneurons and the C2C12 myotubes survived in the co-culture system, with further differentiation and maturation. On day 3 the axons extended to the myotube membrane surface or surrounded the myotubes. On day 7 the myotubes were arranged in the same direction, with wide rhythmic contraction, and immunofluorescence showed that crBTX specifically bound to AChR of the postsynaptic membrane. On day 10 of co-culture, the motor neurons began to have apoptosis and the myotube cells gradually shrank. Conclusion Under in vitro culture condition, motor neurons and skeletal muscle cells can co-exist and grow, establishing synaptic connections, triggering a series of neuromuscular junction signal transduction, and causing rhythmic contraction of the myotubes.

Influence of cholangiocardnoma cells on endothelial cells in a co-culture system / 中华消化外科杂志

Objective To study the influence of cholangiocarcinoma cells on endothelial cells in a co-culture system. Methods A co-culture system of eholangioeareinoma cell line QBC939> and endothelial cells was established in vitro (co-culture group). Endothelial cells were cultured individually during the same time (control group). The mixed supematant of cholangiecareinoma cells and endothelial cells was in the mixed group. Light microscopy and transmission electron micrescopy were used to observe the morphology of the endothelial cells. Changes in expression of ppI25FAK, MMP-2, MMP-9 and uPA of the endothelial cells were detected by mmunofluorescence, and the activities of MMP-2 and MMP-9 were detected by gelatin zymography. All the data were analyzed by paired t test. Results The intercellular space between endothelial cells in co-cuhure group was wider than in the control group. The expression of pp125FAK, MMP-2, MMP-9 and uPA was 394 ±51,455±82, 377±48,422±55 in control group, and was 1096±128,931±72,815±76,801±56 in the eo-euhure group. The difference between the 2 groups had statistical significance (t = 6.53,4.32, 3.61,3.45, P < 0. 05). The values of gray-scale scanning of MMP-2 and MMP-9 in the mixed group were 240.2±15.2 and 2.4±0.8, respectively. The values of gray-scale scanning of MMP-2 and MMP-9 in the co-culture group were significantly increased, they were 687.4 ± 43.6 and 150.9 ± 13.2, respectively (t = 4.89, 5.43, P < 0.05). Conclusions The intercellular space between endothelial ceils and the expression of the proteolytie enzymes are increased after co-culturing endothelial cells with eholangiocarcinoma cells. Proteolytie enzymes may be involved in the process of degradation of subendothelial matrix, and promotes the metastasis of cholangiocarcinoma.

Expression of Hepatitis C Virus Core Protein in Hepatocytes Does Not Modulate Proliferation or Apoptosis of CD8+ T Cells

Hepatocytes are the primary targets of the hepatitis C virus (HCV). While immunosuppressive roles of HCV core protein have been found in several studies, it remains uncertain whether core protein expressed in hepatocytes rather than in immune cells affects the CD8+ T cell response. In order to transduce genes selectively into hepatocytes, we developed a baculoviral vector system that enabled primary hepatocytes to express a target epitope for CD8+ T cells, derived from ovalbumin (OVA), with or without HCV core protein. Culture of OVA-specific CD8+ T cells with hepatocytes infected with these baculoviral vectors revealed that core protein has no effect on proliferation or apoptosis of CD8+ T cells. Our results suggest that HCV core protein does not exert its suppressive role on the CD8+ T cell immune response through expression in hepatocytes.