The Effects of Endometrial Mesenchymal Stem Cells on The In Vitro Maturation of Germinal Vesicle Oocytes in Hanging Drop and Sodium Alginate Hydrogel Co-Culture Systems.

BACKGROUND: The aim of this study is to investigate the co-culture effects of human endometrial mesenchymal stem cells (EnMSCs) with mouse oocytes to enhance their maturation and development by using the hanging drop and sodium alginate hydrogel methods. MATERIALS AND METHODS: In this experimental study, we prepared human EnMSCs (2.5×105 cells/mL) and co-cultured them with partially denuded mouse oocytes by the hanging drop (n=120) and sodium alginate hydrogel (n=120) methods. Control oocytes (n=230, total) were cultured in both systems in the absence of human EnMSCs for 18 hours. Both survival and maturation rates of the oocytes were analysed morphologically. After insemination with capacitated sperm, the fertilization and development of the embryos up to the blastocyst stage were assessed and compared statistically for all of the study groups via one-way ANOVA and the t tests. RESULTS: Oocytes cultured in the hanging drop method had a significantly higher survival rate than their control group (92.60 ± 4.36% vs. 84.20 ± 3.12%, P=0.018). There were no significant differences between the two experimental groups in terms of survival. The mean percent of oocytes that reached the metaphase II (MII) stage was 64.35 ± 3.19% and fertilised was 62.25 ± 4.43% in the hanging drop method; these rates were 63.43 ± 1.92% and 58.14 ± 4.14 in sodium alginate hydrogel method, respectively. These rates were higher than their controls (P<0.050), but there were no statistical differences between the two experimental groups (P>0.050). Among the studied groups, the highest significant blastocyst rate (32.55 ± 2.18%) was observed in the hanging drop experimental group (P=0.0017). CONCLUSION: The results of this study show that human EnMSCs improve the survival, maturation, and development rates of oocytes and they could have future clinical applications.

Preservation of epidermal melanocyte integrity in an ex vivo co-culture skin model with sebocytes.

A direct contact co-culture of skin explants to SZ95 sebocytes (3D-SeboSkin) has been shown to preserve the integrity of epidermal keratinocytes and dermis. In this study, the properties of epidermal melanocytes were evaluated in the same 3D SeboSkin ex vivo model. Skin explants (n = 6) were maintained in the 3D-SeboSkin model, in direct contact to fibroblasts and alone in serum-free medium (SFM). Histopathological, immunohistochemical, apoptosis and oil red staining evaluations were performed at Days 0 and 6 of incubation. Results revealed preservation and prominent proliferation of basal keratinocytes of the skin explants in addition to preservation of dermal collagen and vasculature at Day 6 in the 3D-SeboSkin culture model and to a lesser extent in co-culture with fibroblasts but not in SFM alone. Melan-A+/Ki67- epidermal melanocytes remained attached to the dermis even at sites of epidermal detachment in the three skin explant models tested. However, the number of epidermal melanocytes was significantly conserved in 3D-SeboSkin cultures in comparison with skin explants in SFM (p < 0.05), whereas no difference was found in comparison with the co-culture with fibroblasts. Few DAPI/TUNEL+ apoptotic melanocytes could mostly be observed in SFM-incubated skin explants. Furthermore, only SZ95 sebocytes in contact to skin explants in 3D-SeboSkin exhibited increased lipogenesis with accumulation of abundant lipid droplets. These results denote that the 3D-SeboSkin model yielded significant preservation of epidermal melanocytes and hence it is optimal for ex vivo studies of abnormalities of skin pigmentation, melanocyte neoplasms and effects of different hormones, cytokines, carcinogens and various therapeutics in a pattern that recapitulates the in vivo environment.

Observations that suggest a contribution of altered dermal papilla mitochondrial function to androgenetic alopecia.

Androgenetic alopecia (AGA) is a prevalent hair loss condition in males that develops due to the influence of androgens and genetic predisposition. With the aim of elucidating genes involved in AGA pathogenesis, we modelled AGA with three-dimensional culture of keratinocyte-surrounded dermal papilla (DP) cells. We co-cultured immortalised balding and non-balding human DP cells (DPCs) derived from male AGA patients with epidermal keratinocyte (NHEK) using multi-interfacial polyelectrolyte complexation technique. We observed up-regulated mitochondria-related gene expression in balding compared with non-balding DP aggregates which indicated altered mitochondria metabolism. Further observation of significantly reduced electron transport chain complex activity (complexes I, IV and V), ATP levels and ability to uptake metabolites for ATP generation demonstrated compromised mitochondria function in balding DPC. Balding DP was also found to be under significantly higher oxidative stress than non-balding DP. Our experiments suggest that application of antioxidants lowers oxidative stress levels and improves metabolite uptake in balding DPC. We postulate that the observed up-regulation of mitochondria-related genes in balding DP aggregates resulted from an over-compensatory effort to rescue decreased mitochondrial function in balding DP through the attempted production of new functional mitochondria. In all, our three-dimensional co-culturing revealed mitochondrial dysfunction in balding DPC, suggesting a metabolic component in the aetiology of AGA.

A Fiber Alginate Co-culture Platform for the Differentiation of mESC and Modeling of the Neural Tube.

Alginate hydrogels are a commonly used substrate for in vitro 3D cell culture. These naturally derived biomaterials are highly tunable, biocompatible, and can be designed to mimic the elastic modulus of the adult brain at 1% w/v solution. Recent studies show that the molecular weight of the alginate can affect cell viability and differentiation. The relationship between the molecular weight, viscosity and ratio of G:M monomers of alginate hydrogels is complex, and the balance between these factors must be carefully considered when deciding on a suitable alginate hydrogel for stem cell research. This study investigates the formation of embryoid bodies (EB) from mouse embryonic stem cells, using low molecular weight (LMW) and high molecular weight (HMW) alginates. The cells are differentiated using a retinoic acid-based protocol, and the resulting aggregates are sectioned and stained for the presence of stem cells and the three germ layers (endoderm, mesoderm, and ectoderm). The results highlight that aggregates within LMW and HMW alginate are true EBs, as demonstrated by positive staining for markers of the three germ layers. Using tubular alginate scaffolds, formed with an adapted gradient maker protocol, we also propose a novel 3D platform for the patterned differentiation of mESCs, based on gradients of retinoic acid produced in situ by lateral motor column (LMC) motor neurons. The end product of our platform will be of great interest as it can be further developed into a powerful model of neural tube development.

Influence of static forces on the expression of selected parameters of inflammation in periodontal ligament cells and alveolar bone cells in a co-culture in vitro model.

OBJECTIVE: Aim of this study was to investigate the impact of human PDL-derived fibroblasts (HPDF) and human alveolar bone-derived osteoblasts (HABO) co-culture on the expression of cytokines involved in tissue remodeling using an in vitro compressive force (CF) model. MATERIALS AND METHODS: Static compressive force (CF) of 47.4 g/cm2 was applied on mono- and co-cultured HPDFs and HABOs for 1, 2, or 4 h at 30 °C. TNFA, PTGS2, and IL6 gene expressions were determined by quantitative real-time polymerase chain reaction. TNF, PGE2, and IL6 concentrations were measured using enzyme-linked immunosorbent assay. RESULTS: In mono-culture, TNFA, PTGS2, and IL6 gene expressions were upregulated under CF as compared to controls for each time period in both cell types. PGE2 increased at 1 and 2 h in both cell types, and IL6 increased only at 2 and 4 h in HPDFs. Co-culture alleviated the force-induced increase of the expression of TNFA, PTGS2, IL6, PGE2, and IL6 in HPDFs at any time point. In HABOs, co-cultivation decreased the expression of PGE2 after 1 h and 4 h, and that of IL6 after 1 h compared to mono-culture. CONCLUSIONS: CF application on co-cultures of HPDFs and HABOs causes significant changes of TNFA, PTGS2, and IL6 gene expressions and PGE2 and IL6 production in comparison to mono-culture indicating intercellular communication. CLINICAL RELEVANCE: Mechanical stimulation of HPDFs and HABOs in co-culture induces a different gene expression pattern than stimulation of individual cell types alone. Co-culture might therefore be a relevant method to elucidate periodontal regeneration during orthodontic therapy.

Reduction of marginal mass required for successful islet transplantation in a diabetic rat model using adipose tissue-derived mesenchymal stromal cells.

BACKGROUND AIMS: Adipose tissue-derived mesenchymal stromal cells (AT-MSCs), widely known as multipotent progenitors, release several cytokines that support cell survival and repair. There are in vitro and in vivo studies reporting the regenerative role of AT-MSCs possibly mediated by their protective effects on functional islet cells as well as their capacity to differentiate into insulin-producing cells (IPCs). METHODS: On such a basis, our goal in the present study was to use three different models including direct and indirect co-cultures and islet-derived conditioned medium (CM) to differentiate AT-MSCs into IPCs and to illuminate the molecular mechanisms of the beneficial impact of AT-MSCs on pancreatic islet functionality. Furthermore, we combined in vitro co-culture of islets and AT-MSCs with in vivo assessment of islet graft function to assess whether co-transplantation of islets with AT-MSCs can reduce marginal mass required for successful islet transplantation and prolong graft function in a diabetic rat model. RESULTS: Our findings demonstrated that AT-MSCs are suitable for creating a microenvironment favorable for the repair and longevity of the pancreas ß cells through the improvement of islet survival and maintenance of cell morphology and insulin secretion due to their potent properties in differentiation. Most importantly, hybrid transplantation of islets with AT-MSCs significantly promoted survival, engraftment and insulin-producing function of the graft and reduced the islet mass required for reversal of diabetes. CONCLUSIONS: This strategy might be of therapeutic potential solving the problem of donor islet material loss that currently limits the application of allogeneic islet transplantation as a more widespread therapy for type 1 diabetes.

Evaluation of the secretion and release of vascular endothelial growth factor from two-dimensional culture and three-dimensional cell spheroids formed with stem cells and osteoprecursor cells.

BACKGROUND: Co-culture has been applied in cell therapy, including stem cells, and has been reported to give enhanced functionality. OBJECTIVES: In this study, stem-cell spheroids were formed in concave micromolds at different ratios of stem cells to osteoprecursor cells, and the amount of secretion of vascular endothelial growth factor (VEGF) was evaluated. MATERIAL AND METHODS: Gingiva-derived stem cells and osteoprecursor cells in the amount of 6 × 105 were seeded on a 24-well culture plate or concave micromolds. The ratios of stem cells to osteoprecursor cells included: 0:4 (group 1), 1:3 (group 2), 2:2 (group 3), 3:1 (group 4), and 4:0 (group 5). RESULTS: The morphology of cells in a 2-dimensional culture (groups 1-5) showed a fibroblast-like appearance. The secretion of VEGF increased with the increase in stem cells, and a statistically significant increase was noted in groups 3, 4 and 5 when compared with the media-only group (p < 0.05). Osteoprecursor cells formed spheroids in concave microwells, and no noticeable change in the morphology was noted with the increase in stem cells. Spheroids containing stem cells were positive for the stem-cell markers SSEA-4. The secretion of VEGF from cell spheroids increased with the increase in stem cells. CONCLUSIONS: This study showed that cell spheroids formed with stem cells and osteoprecursor cells with different ratios, using microwells, had paracrine effects on the stem cells. The secretion of VEGF increased with the increase in stem cells. This stem-cell spheroid may be applied for tissue-engineering purposes.

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.

Endothelial cells co-cultured with renal carcinoma cells significantly reduce RECK expression under chemical hypoxia.

Renal cell carcinoma (RCC) is characterized by excessive angiogenesis, while chronic kidney disease (CKD) suffers from the opposite problem-failure of reparative angiogenesis. It can be due to their different responses to hypoxic environment. But the specific molecular regulators are still unclear. This study is aimed to explore the influence of human renal cell cancer cells (786-0) and human renal tubular epithelial cells (HK-2) on RECK expression, proliferation, and angiogenesis of adjacent microvascular endothelial cells (HMEC-1) under chemical hypoxia. Cobalt chloride (CoCl2 ) treatment was used to simulate the hypoxia environment in RCC and CKD. Co-culture, cell proliferation assay, and tube formation assay were used to evaluate the influence of 786-0 or HK-2 cells on proliferation and angiogenesis of adjacent HMEC-1 cells. Effects of different environments on RECK expressions in 786-0, HK2, or HMEC-1 cells were determined by Western blot. We found that both 786-0 cells and HK2 cells can upregulate RECK expression of adjacent HMEC-1 cells in normoxic conditions. However, under hypoxia, the HMEC-1 cells co-cultured with 786-0 significantly reduced RECK expression and there was no significant change in HMEC-1 cells co-cultured with HK2 cells. We also found that 786-0 significantly enhanced the proliferation and angiogenesis of adjacent HMEC-1 cells. Our results suggested that some paracrine substances produced by 786-0 cells may reduce RECK expression of adjacent HMEC-1 cells and enhance their proliferation and in vitro angiogenic capacity.

Evaluation of the shape, viability, stemness and osteogenic differentiation of cell spheroids formed from human gingiva-derived stem cells and osteoprecursor cells.

The present study was performed to create stem cell spheroids from human gingiva-derived stem cells and osteoprecursor cells and to evaluate the maintenance of the stemness, the viability and osteogenic differentiation of the cell spheroids. Gingiva-derived stem cells were isolated, and a total of 6×105 stem cells and osteoprecursor cells were seeded into concave micromolds at various ratios. Gingiva-derived stem cells and/or osteoprecursor cells formed spheroids in concave microwells. The spheroids demonstrated a smaller diameter when the number of osteoprecursor cells seeded was lower. The majority of cells in the spheroids were identified to be live cells and the cell spheroids preserved viability throughout the experimental period. The cell spheroids, which contained stem cells, were positive for stem-cell markers. Cell spheroids in concave microwells demonstrated a statistically significant increase in alkaline phosphatase activity as time progressed (P<0.05). A statistically significant difference in phosphatase activity was observed in the stem cell alone group when compared with the osteoprecursor cell group at day 5 (P<0.05). Mineralized extracellular deposits were observed in each group after Alizarin Red S staining. Within the limits of the present study, cell spheroids from gingival cells and osteoprecursor cells maintained shape, viability, stemness and osteogenic differentiation potential.

Characterization of A Three-Dimensional Organotypic Co-Culture Skin Model for Epidermal Differentiation of Rat Adipose-Derived Stem Cells.

OBJECTIVE: The organotypic co-culture is a well-known technique to examine cellular interactions and their roles in stem cell proliferation and differentiation. This study aims to evaluate the effects of dermal fibroblasts (DFs) on epidermal differentiation of adipose-derived stem cells (ASCs) using a three-dimensional (3D) organotypic co- culture technique. MATERIALS AND METHODS: In this experimental research study, rat DFs and ASCs were isolated and cultured separately on electrospun polycaprolactone (PCL) matrices. The PCL matrices seeded by ASCs were superimposed on to the matrices seeded by DFs in order to create a 3D organotypic co-culture. In the control groups, PCL matrices seeded by ASCs were placed on matrices devoid of DFs. After 10 days, we assessed the expressions of keratinocyte-related genes by real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and expression of pan-cytokeratin protein by immunofluorescence in the differentiated keratinocyte-like cells from co- culture and control groups. Keratinocyte-like cell morphologies were also observed by scanning electron microscopy (SEM). RESULTS: The early, intermediate, and terminal differentiation keratinocyte markers-Cytokeratin14, Filaggrin, and Involucrin significantly expressed in the co-culture groups com- pared to the control ones (P<0.05). We observed pan-cytokeratin in keratinocyte-like cells of both groups by immunofluorescence. SEM observation of the co-culture groups showed that the differentiated keratinocyte-like cells developed a polygonal cobblestone shape, considered characteristic of keratinocytes. CONCLUSION: The 3D organotypic co-culture bilayered construct that consisted of DFs and ASCs was an effective technique for epidermal differentiation of ASCs. This co-culture might be useful for epidermal differentiation of stem cells for future applications in skin regeneration.

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.

Dorsal root ganglion neurons promote proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells.

Preliminary animal experiments have confirmed that sensory nerve fibers promote osteoblast differentiation, but motor nerve fibers have no promotion effect. Whether sensory neurons promote the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells remains unclear. No results at the cellular level have been reported. In this study, dorsal root ganglion neurons (sensory neurons) from Sprague-Dawley fetal rats were co-cultured with bone marrow mesenchymal stem cells transfected with green fluorescent protein 3 weeks after osteogenic differentiation in vitro, while osteoblasts derived from bone marrow mesenchymal stem cells served as the control group. The rat dorsal root ganglion neurons promoted the proliferation of bone marrow mesenchymal stem cell-derived osteoblasts at 3 and 5 days of co-culture, as observed by fluorescence microscopy. The levels of mRNAs for osteogenic differentiation-related factors (including alkaline phosphatase, osteocalcin, osteopontin and bone morphogenetic protein 2) in the co-culture group were higher than those in the control group, as detected by real-time quantitative PCR. Our findings indicate that dorsal root ganglion neurons promote the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells, which provides a theoretical basis for in vitro experiments aimed at constructing tissue-engineered bone.

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.

Surrounding cells affect the gene expression pattern of human beta-defensins in squamous cell carcinoma in vitro.

BACKGROUND/AIM: Defensins are basic peptides involved in non-immune bio-defense mechanisms in a normal epithelium. Human oral squamous cell carcinoma cells (OSCC) also produce human beta-defensins (HBDs), although their exact function is not clear. This study aimed to analyze the variation in gene expression levels of hBDs in co-cultures of OSCC with murine cells. MATERIALS AND METHODS: Two OSCC cell lines (HSC-3, HSC-4) were co-cultured with mouse embryonic fibroblasts, NIH/3T3 or a mouse chondrogenic cell line derived from teratocarcinoma, ATDC5, for 1.5 days. Expression patterns of the hBD genes were investigated by real-time polymerase chain reaction (RT-PCR). RESULTS: hBD1 expression increased when co-cultured with NIH/3T3 but decreased when co-cultured with ATDC5. Expression of hBD2 and hBD4 tended to decrease. OSCC cells formed colonies when co-cultured with NIH/3T3 but were scattered when co-cultured with ATDC5. CONCLUSION: hBDs expression in OSCC is dependent on the type of co-cultured cells and differences in gene expression may be responsible for the morphological differences observed. OSCC may produce HBDs for purposes other than bio-defense by surrounding cells.

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.