Influence Of Conditioned Medium Research Articles

Profiling the 3D interaction between germ cell tumors and microenvironmental cells at the transcriptome and secretome level.

The tumor microenvironment (TM), consisting of the extracellular matrix (ECM), fibroblasts, endothelial cells, and immune cells, might affect tumor invasiveness and the outcome of standard chemotherapy. This study investigated the cross talk between germ cell tumors (GCT) and surrounding TM cells (macrophages, T‐lymphocytes, endothelial cells, and fibroblasts) at the transcriptome and secretome level. Using high‐throughput approaches of three‐dimensional (3D) co‐cultured cellular aggregates, this study offers newly identified pathways to be studied with regard to sensitivity toward cisplatin‐based chemotherapy or tumor invasiveness as a consequence of the cross talk between tumor cells and TM components. Mass‐spectrometry‐based secretome analyses revealed that TM cells secreted factors involved in ECM organization, cell adhesion, angiogenesis, and regulation of insulin‐like growth factor (IGF) transport. To evaluate direct cell–cell contacts, green fluorescent protein (GFP)‐expressing GCT cells and mCherry‐expressing TM cells were co‐cultured in 3D. Afterward, cell populations were separated by flow cytometry and analyzed by RNA sequencing. Correlating the secretome with transcriptome data indicated molecular processes such as cell adhesion and components of the ECM being enriched in most cell populations. Re‐analyses of secretome data with regard to lysine‐ and proline‐hydroxylated peptides revealed a gain in proteins, such as collagens and fibronectin. Cultivation of GCT cells on collagen I/IV‐ or fibronectin‐coated plates significantly elevated adhesive and migratory capacity, while decreasing cisplatin sensitivity of GCT cells. Correspondingly, cisplatin sensitivity was significantly reduced in GCT cells under the influence of conditioned medium from fibroblasts and endothelial cells. This study sheds light on the cross talk between GCT cells and their circumjacent TM, which results in deposition of the ECM and eventually promotes a pro‐tumorigenic environment through enhanced migratory and adhesive capacity, as well as decreased cisplatin sensitivity. Hence, our observations indicate that targeting the ECM and its cellular components might be a novel therapeutic option in combination with cisplatin‐based chemotherapy for GCT patients.

Influence of conditioned media from glial cell cultures on contractility of uterine in rats of different ages

Background. The physiological regulation of the uterine contractile activity changes with age, which leads to an increased number of prolonged labor and emergency caesarean sections in women giving birth at the age of 35+. One of the modern approaches to correct the function of the reproductive system is the use of from cell cultures. CM from glial cell culture contains neurotrophic factors that play an important role in maintaining the contractile function of the uterus. Current cell culture technologies include cryopreservation.Objective: to research experimentally the effect of CM obtained from intact and cryopreserved cultures of glial cells on the contractile activity of the uterus in rats of different reproductive ages.Materials and methods. The monolayer cell culture was obtained from the dorsal root ganglia of neonatal piglets and cryopreserved in the presence of cryoprotectant dimethyl sulfoxide. CM from native and cryopreserved cultures were collected for 28 days, after which fractions with a molecular weight of < 30 kDa were obtained from them by ultrafiltration. Rats at the age of 6 and 14 months, which corresponds to reproductive age and late reproductive age (LRA), were intraperitoneally injected with 0.2 ml of media from intact (ICM) or cryopreserved (CCM) cultures for 9 days. On the 30th – 32nd day after the end of the administration of CM animals were slaughtered and the uterine contractile activity was determined by the organ bath method, the relative area of myometrium and density of myocytes by histological method, the average area of labeling with specific antibodies to smooth muscle actin by immunohistochemical method. The statistical significance of differences was assessed by the Mann–Whitney test.Results. It was found that spontaneous, OT-, and KCl-induced tension of isometric contraction of the uterus in intact LRA rats decreased by 19, 20, and 14%, respectively, compared with intact reproductive aged animals. After the introduction of ICM and CCM in LRA animals, normalization of isometric contraction parameters was observed. This effect was realized against the background of an increase in the area of the myometrium, the density of myocytes, and actin expression.Conclusions. Intra-abdominal administration of CM from glial cell culture increases the uterine contractile activity in LRA rats. This effect is realized by increasing the relative area of the myometrium, the density of myocytes, and the area of expression of smooth muscle actin. The effect of media from intact and cryopreserved cultures on the contractile activity of the uterus was similar, which makes it possible to use low-temperature culture storage technologies to obtain CM without losing its biological effect.

Influence of Conditioned Media on the Re-Differentiation Capacity of Human Chondrocytes in 3D Spheroid Cultures.

A major challenge of cell-based therapy for cartilage lesions is the preservation of the chondrogenic phenotype during ex vivo cell cultivation. In this in vitro study, the chondro-inductive capacity of two different hyaline cartilage-conditioned cell culture media on human chondrocytes in 3D spheroids was determined. Media were conditioned by incubation of 200 mg/mL vital or devitalized cartilage matrix in growth media over 35 days. The media were analyzed for the content of soluble procollagen type (Col) II and glycosaminoglycans (GAGs) as well as released TGF-β1, IGF-1 and IGFBP3. Unconditioned medium served as a negative control while the positive medium control was supplemented with TGF-β1 and IGF-1. Spheroid cultures prepared from human chondrocytes were cultivated at 37 °C, 5% CO2 and 21% O2 in the respective media and controls. After 14 and 35 days, the deposition of ECM components was evaluated by histological analysis. Vital cartilage-conditioned medium contained significantly higher levels of Col II and active TGF-β1 compared to medium conditioned with the devitalized cartilage matrix. Despite these differences, the incubation with vital as well as devitalized cartilage conditioned medium led to similar results in terms of deposition of proteoglycans and collagen type II, which was used as an indicator of re-differentiation of human chondrocytes in spheroid cultures. However, high density 3D cell cultivation showed a positive influence on re-differentiation.

Cyclic tensile strain and pharmacological treatment affects human chondrocytes under inflammatory and non-inflammatory conditions

Purpose: Despite the high prevalence of osteoarthritis (OA), treatment options comprise a limited combination of pharmacological and non-pharmacological therapies aimed at pain reduction and improvement in functionality. While current pharmacologic treatment paradigms such as analgesics and nonsteroidal anti-inflammatory drugs (NSAIDs) provide only symptomatic relief, neither a remission nor a stop in the progression of the disease is achieved. Therefore, new therapeutic strategies aimed at effectiveness and safety is urgently needed. The disease modifying OA drug (DMOAD) diacerein functions as a slow acting drug through anti-inflammatory, anti-catabolic, and pro-anabolic effects on cartilage and the synovial membrane. In addition, many different mechanisms have been shown to be involved in chondrocyte mechanotransduction. Dysregulation of growth factor signaling plays an important role in the pathogenesis of OA and the interplay of growth factors with different possible treatments could open new options for the diagnosis and therapy of the disease. The aim of this study was to analyze human non-OA and OA-chondrocytes in vitro in response to the combined therapy. Methods: The Flexcell FX5K-Tension System was used to apply mechanical cyclic tensile strain on non-OA (unstimulated T/C-28a2) and OA (IL-1β stimulated C-28/I2) human chondrocytes. The mechanical strain profile consisting of 8 h resting and four repetitions of alternate 2 h slow-moving activity (0.2 Hz, 2% elongation) and 2 h high intensity (1 Hz, 15% elongation) was applied for 7 days. Changes in cyclooxygenase-2 (COX-2), interleukin-6 (IL-6), and prostaglandin E2 (PGE2) and the growth factors, platelet-derived growth factor (PDGF), vascular endothelial growth factor A (VEGF-A) and the basic fibroblast growth factor (bFGF) were characterized by quantitative real-time PCR and enzyme linked immune assays (ELISA). Using the xCELLigence DP System device cell proliferation and cell migration under the influence of conditioned medium (which was collected at the end of a seven days Flexcell treatment) were monitored in real-time after cells were seeded on electronic microtiter plates or on electronic cell invasion and migration plates. Results: To evaluate the inflammatory background dependent on the treatment modalities, the relative mRNA expression level for the two inflammatory markers, IL-6 and COX-2, were analyzed. Our data revealed that both mechanical stimulation and diacerein treatment reduced IL-6 expression. COX2 expression was increased by mechanical stimulation, diacerein alone had no effect. COX-2 and in succession PGE-synthase convert arachidonic acid into PGE2, a principle mediator of inflammation in any kind of inflammatory processes. Mechanical stimulation lowered PGE2 synthesis only under OA-conditions. Under OA-conditions the median values were changed in the expression of the PDGF, known to be a potent biological regulator of chondrocytes in cartilage repair. In the non-OA system no changes were observed. Under mechanical stimulation a change in the VEGF expression was observed. FGF-2 represents a member of the FGF family and is found elevated in the synovial fluid of patients with OA. Mechanical stimulation reduced the FGF-2 expression in OA-chondrocytes. A significant increase in cell growth was observed for non-OA and OA-chondrocytes cultured in the presence of the conditioned medium from mechanically stimulated cells. The combined treatment with diacerein inhibited cell proliferation. In addition, conditioned medium derived from mechanical stimulated cells significantly augmented the migration of OA chondrocytes. Conclusions: Cyclic tensile strain appears beneficial for the fate of the cell, and improves the pharmacological effect of diacerein. Improvements are based on cross-talks between different initiated pathways. Combining two different treatment options broadens the perspective to treat OA.

Pharmacological treatment with diacerein combined with mechanical stimulation affects the expression of growth factors in human chondrocytes

BackgroundOsteoarthritis (OA) as the main chronic joint disease arises from a disturbed balance between anabolic and catabolic processes leading to destructions of articular cartilage of the joints. While mechanical stress can be disastrous for the metabolism of chondrocytes, mechanical stimulation at the physiological level is known to improve cell function. The disease modifying OA drug (DMOAD) diacerein functions as a slowly-acting drug in OA by exhibiting anti-inflammatory, anti-catabolic, and pro-anabolic properties on cartilage. Combining these two treatment options revealed positive effects on OA-chondrocytes. MethodsCells were grown on flexible silicone membranes and mechanically stimulated by cyclic tensile loading. After seven days in the presence or absence of diacerein, inflammation markers and growth factors were analyzed using quantitative real-time PCR and enzyme linked immune assays. The influence of conditioned medium was tested on cell proliferation and cell migration. ResultsTensile strain and diacerein treatment reduced interleukin-6 (IL-6) expression, whereas cyclooxygenase-2 (COX2) expression was increased only by mechanical stimulation. The basic fibroblast growth factor (bFGF) was down regulated by the combined treatment modalities, whereas prostaglandin E2 (PGE2) synthesis was reduced only under OA conditions. The expression of platelet-derived growth factor (PDGF) and vascular endothelial growth factor A (VEGF-A) was down-regulated by both. ConclusionsFrom our study we conclude that moderate mechanical stimulation appears beneficial for the fate of the cell and improves the pharmacological effect of diacerein based on cross-talks between different initiated pathways. General significanceCombining two different treatment options broadens the perspective to treat OA and improves chondrocytes metabolism.

Matrix metalloproteases as maestros for the dual role of LPS- and IL-10-stimulated macrophages in cancer cell behaviour.

BackgroundThe interactions established between macrophages and cancer cells are largely dependent on instructions from the tumour microenvironment. Macrophages may differentiate into populations with distinct inflammatory profiles, but knowledge on their role on cancer cell activities is still very scarce. In this work, we investigated the influence of pro-inflammatory (LPS-stimulated) and anti-inflammatory (IL-10-stimulated) macrophages on gastric and colorectal cancer cell invasion, motility/migration, angiogenesis and proteolysis, and the associated molecular mechanisms.MethodsFollowing exposure of gastric and colon cancer cell lines to LPS- and IL-10-stimulated human macrophages, either by indirect contact or conditioned media, we analyzed the effect of the different macrophage populations on cancer cell invasion, migration, motility and phosphorylation status of EGFR and several interacting partners. Cancer-cell induced angiogenesis upon the influence of conditioned media from both macrophage populations was assessed using the chick embryo chorioallantoic membrane assay. MMP activities were evaluated by gelatin zymograhy.ResultsOur results show that IL-10-stimulated macrophages are more efficient in promoting in vitro cancer cell invasion and migration. In addition, soluble factors produced by these macrophages enhanced in vivo cancer cell-induced angiogenesis, as opposed to their LPS-stimulated counterparts. We further demonstrate that differences in the ability of these macrophage populations to stimulate invasion or angiogenesis cannot be explained by the EGFR-mediated signalling, since both LPS- and IL-10-stimulated macrophages similarly induce the phosphorylation of cancer cell EGFR, c-Src, Akt, ERK1/2, and p38. Interestingly, both populations exert distinct proteolytic activities, being the IL-10-stimulated macrophages the most efficient in inducing matrix metalloprotease (MMP)-2 and MMP-9 activities. Using a broad-spectrum MMP inhibitor, we demonstrated that proteolysis was essential for macrophage-mediated cancer cell invasion and angiogenesis.ConclusionsWe propose that IL-10- and LPS-stimulated macrophages distinctly modulate gastric and colorectal cancer cell behaviour, as result of distinct proteolytic profiles that impact cell invasion and angiogenesis.

Comparision influence of conditioned medium of human mesenchimal cells and interferon-α on development of tumor cell population

This work is a study of mediators and mechanisms of the effect of human mesenchymal stem cells from bone marrow (hMSC BM) on the tumor cell population line MCF-7 (breast adenocarcinoma). It is known that MSCs produce a wide range of cytokines and chemokines, and provide humoral cells interaction. BM MSCs produce tumor necrosis factor (TNF-α), interleukin (IL-1β, IL-2, IL-4, IL-6, IL-8), interferon-alpha (IFN-α). In this study we compared the proliferation, adhesion, survival and antigenic profile of breast adenocarcinoma cells that were cultured with conditioned medium (с-medium) of the MSC and IFN-α. Consequently, it was found that с-medium from MSC inhibited proliferation activity of MCF-7, increased cells adhesion, suppressed the ability to migrate, and reduced the expression of estrogen receptor and epidermal growth factor receptor. Conversely expression of cytokeratins increased, which is a positive sign for the tumor cells of epithelial origin. IFN-α showed a more pronounced effect on the tumor population. These findings suggest that cryopreserved MSC BM has antitumor activity. Also, our data suggest that IFN-alpha is one of the mediators of antitumor effect of MSCs.

Abstract 468: Down-regulation of TNFSF15 (VEGI) in tumor vasculature under inflammatory conditions is a pre-requisite of tumor neovascularization

Abstract Tumor necrosis factor superfamily-15 (TNFSF15; VEGI) is an endogenous inhibitor of neovascularization. TNFSF15 is largely produced by quiescent vascular endothelial cells in an established vasculature but is markedly down-regulated in endothelial cells undergoing proliferation such as those in tumors or at a wound site. Recombinant TNFSF15 is a potent inhibitor of endothelial cell proliferation and tumor growth. We hypothesize that TNFSF15 as a negative regulator of angiogenesis must be down-regulated prior to the initiation of angiogenesis, and that the inflammatory conditions created by cancer cells and infiltrating lymphocytes lead to TNFSF15 down-modulation in the microenvironment, permitting new blood vessel growth. We analyzed normal ovary tissues (n=12) and clinical specimens of ovarian cancer (n=86; including stages I, II, III and IV) for the expression of TNFSF15, the endothelial cell marker PECAM (CD31), and tumor-infiltrating T-cell markers CD4 and CD25. We found that the degree of T-cell infiltration increases markedly while TNFSF15 expression diminishes as the disease progresses. We then determined the influence of human ovarian cancer cell line OVCAR-3 cell conditioned media on cytokine production by human CD4+ T-cells and CD4+CD25+ Treg cells, as well as the influence of the conditioned media of the latter two cells on TNFSF15 expression in human umbilical vein endothelial cells (HUVEC). We found that the conditioned media of Th1 or Treg cells can inhibit HUVEC TNFSF15 expression only after the lymphocytes being treated with OVCAR-3 conditioned media. Interestingly, we further found that mouse ovarian cancer ID8 cells implanted subcutaneously on mice treated with TNFSF15 shRNA at the injection sites exhibit significantly greater tumor growth rates compared with control shRNA treated ones. Our findings indicate that TNFSF15 plays a critical role in the maintenance of vascular stability as its down-modulation is a pre-requisite for the initiation of tumor neovascularization, and that TNFSF15 down-regulation is carried out by tumor-infiltrating T-cells under the influence of the cancer cells in the microenvironment. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 468. doi:10.1158/1538-7445.AM2011-468

Co-culture of Retinal and Endothelial Cells Results in the Modulation of Genes Critical to Retinal Neovascularization

BackgroundNeovascularization (angiogenesis) is a multistep process, controlled by opposing regulatory factors, which plays a crucial role in several ocular diseases. It often results in vitreous hemorrhage, retinal detachment, neovascularization glaucoma and subsequent vision loss. Hypoxia is considered to be one of the key factors to trigger angiogenesis by inducing angiogenic factors (like VEGF) and their receptors mediated by hypoxia inducible factor-1 (HIF-1α) a critical transcriptional factor. Another factor, nuclear factor kappa B (NFκB) also regulates many of the genes required for neovascularization, and can also be activated by hypoxia. The aim of this study was to elucidate the mechanism of interaction between HRPC and HUVEC that modulates a neovascularization response.MethodsHuman retinal progenitor cells (HRPC) and human umbilical vein endothelial cells (HUVEC) were cultured/co-cultured under normoxia (control) (20% O2) or hypoxia (1% O2) condition for 24 hr. Controls were monolayer cultures of each cell type maintained alone. We examined the secretion of VEGF by ELISA and influence of conditioned media on blood vessel growth (capillary-like structures) via an angiogenesis assay. Total RNA and protein were extracted from the HRPC and HUVEC (cultured and co-cultured) and analyzed for the expression of VEGF, VEGFR-2, NFκB and HIF-1α by RT-PCR and Western blotting. The cellular localization of NFκB and HIF-1α were studied by immunofluorescence and Western blotting.ResultsWe found that hypoxia increased exogenous VEGF expression 4-fold in HRPC with a further 2-fold increase when cultured with HUVEC. Additionally, we found that hypoxia induced the expression of the VEGF receptor (VEGFR-2) for HRPC co-cultured with HUVEC. Hypoxia treatment significantly enhanced (8- to 10-fold higher than normoxia controls) VEGF secretion into media whether cells were cultured alone or in a co-culture. Also, hypoxia was found to result in a 3- and 2-fold increase in NFκB and HIF-1α mRNA expression by HRPC and a 4- and 6-fold increase in NFκB and HIF-1α protein by co-cultures, whether non-contacting or contacting.Treatment of HRPC cells with hypoxic HUVEC-CM activated and promoted the translocation of NFκB and HIF-1α to the nuclear compartment. This finding was subsequently confirmed by finding that hypoxic HUVEC-CM resulted in higher expression of NFκB and HIF-1α in the nuclear fraction of HRPC and corresponding decrease in cytoplasmic NFκB and HIF-1α. Lastly, hypoxic conditioned media induced a greater formation of capillary-like structures (angiogenic response) compared to control conditioned media. This effect was attenuated by exogenous anti-human VEGF antibody, suggesting that VEGF was the primary factor in the hypoxic conditioned media responsible for the angiogenic response.ConclusionsThese findings suggest that intercellular communications between HRPC and HUVEC lead to the modulation of expression of transcription factors associated with the production of pro-angiogenic factors under hypoxic conditions, which are necessary for an enhanced neovascular response. Our data suggest that the hypoxia treatment results in the up-regulation of both mRNA and protein expression for VEGF and VEGFR-2 through the translocation of NFκB and HIF-1α into the nucleus, and results in enhanced HRPC-induced neovascularization. Hence, a better understanding of the underlying mechanism for these interactions might open perspectives for future retinal neovascularization therapy.

Influence of enteric bacteria conditioned media on recovery of Escherichia coli O157:H7 exposed to starvation and sodium hypochlorite

To examine the effect that starvation and sodium hypochlorite stress have on virulence of Escherichia coli O157:H7 and the influence of conditioned media on recovery of stressed cells. Escherichia coli O157:H7 was starved for 5 days then exposed to 1 microg ml(-1) sodium hypochlorite, suspended in defined media Dulbecco's Modified Eagle's Medium supplemented with conditioned media, sampled over a 12-h period; and assayed for growth, production of Shiga toxin (Stx), and attachment to HCT-8 cells. During recovery, stressed and control cells grown in conditioned media exhibited greater attachment efficiencies to HCT-8 cells then cells in DMEM alone. Production of Stx by treated cells mimicked Stx production by control cells suggesting that components of conditioned media assist in recovery. Results showed that levels of autoinducer-2 fluctuate during recovery and growth suggesting involvement of a quorum sensing mechanism during the recovery of stressed E. coli O157:H7. The recovery of stressed E. coli O157:H7 exposed to starvation conditions and HOCl is positively affected by the presence of autoinducer-2 thereby influencing virulence factor production. Food-borne pathogens in a stressed state prior to ingestion can rapidly recover in the presence of bacterial by-products; exhibiting virulence characteristics and presenting a microbial food safety hazard.

Effect of Conditioned Medium Factors on Productivity and Cell Physiology in Trichoplusia ni Insect Cell Cultures

The influence of conditioned medium (CM) on cell physiology and recombinant protein production in Trichoplusia ni insect cells (T. ni, BTI-Tn-5B1-4) has been investigated. Cell cycle analysis showed that a high proportion of the cell population (80-90%) was in G1 during the whole culture, indicating that the S and G2/M phases are short relative to the G1 phase. Directly after inoculation, a rapid decrease of the S-phase population occurred, which could be observed as a lag-phase. The following increase in the number of cells in S occurred after 7 h of culture for cells in fresh medium, whereas for cells with the addition of CM it occurred at an earlier time point (5 h) and these cells had therefore a shorter lag-phase. The initial changes in the S-phase population were also affected by the inoculum cell density, as higher seeding cell densities resulted in a more rapid increase in the S-phase population after inoculation. These changes in cell cycle distribution were reflected in the cell size, and the CM-cells were smaller than the cells in fresh medium. Recombinant protein production in T. ni cells was improved by the addition of CM. The specific productivity was increased by 30% compared to cells in fresh medium. This beneficial effect was seen between 20 and 72 h of culture. In contrast, the highest specific productivity was obtained already at 7 h for the cells in fresh medium and then decreased rapidly. The total product concentration was around 30% higher in the culture with CM compared to the culture in fresh medium, and the maximum product concentration was obtained on day 2 compared to day 3 for the cells in fresh medium. Our results indicate that the positive effect on productivity by CM is related to its growth-promoting effect, suggesting that the proliferation potential of the culture determines the productivity.

Effect of growth phase on the Escherichia coli response to ultraviolet-A radiation: influence of conditioned media, hydrogen peroxide and acetate

The results reported herein indicate that the ultraviolet-A (UVA) radiation-induced effects in Escherichia coli depend on its growth phase. Stationary-phase cells recover faster from a sub-lethal UVA exposure and have a higher resistance to lethal effect of the radiation than exponential growing cells. Although pre-incubation in spent medium supernatant increased the resistance of log-phase cells to lethal UVA effects, this pre-treatment considerably prolonged the duration of the radioinduced sub-lethal growth delay. The aim of the present study was to investigate the effect exerted by the E. coli conditioned media and evaluate the influence of nutritional stress, hydrogen peroxide and acetate. Pre-incubated in conditioned medium, cells in exponential growth phase were irradiated and the induced effects were compared with those found when catalase, high culture densities and acetate were employed. Unexpectedly, the duration of the growth delay in cells submitted to these treatments was shortened in comparison with control cells incubated in conditioned medium with no modifications. Lengthening of the growth delay was mimicked when exponentially growing cells were incubated in fresh medium supplied with 5 μM H 2O 2. The effects of spent medium on wild type and rpoS mutant strains were similar, indicating that this response is independent of RpoS controlled functions. We assumed that an oxidative component of the spent medium, probably H 2O 2, could be involved in the observed phenomenon. This effect is specific of E. coli and independent of rpoS.

Increased matrix metalloproteinase-9 activity in human ovarian cancer cells cultured with conditioned medium from human peritoneal tissue.

Ovarian cancer cells disseminate by attachment to the peritoneal mesothelial cell surface of the abdominal cavity. We therefore investigated the influence of conditioned medium (CM) from human peritoneal tissues and mesothelial cells on the secretion of matrix metalloproteinases (MMPs) by ovarian cancer cells. The molecular weights of MMPs stimulating factors derived from human peritoneal tissues and mesothelial cells were estimated using microconcentrators with various cut-off membranes. Human peritoneal tissues were obtained from 12 surgical patients, and mesothelial cells were isolated from three peritoneal specimens. Exposure to CM from peritoneal tissue caused a concentration-dependent increase of the MMP-2 and MMP-9 bands in CM from NOM1 ovarian cancer cells, as shown by zymography. There was a significant difference in the increase of MMP-2 and MMP-9 (2.46-fold and 7.14-fold, respectively, at 0.4 mg/ml protein; P < 0.005). CM from mesothelial cells also significantly increased the secretion of MMP-9 by NOM1 cells. The molecular size of possible MMP-9-stimulating factors secreted by peritoneal tissues and mesothelial cells was above M(r) 100000. Further, CM of peritoneal tissues and mesothelial cells also induced the invasiveness of NOM1 cells. These findings suggest that mesothelial cells may secrete some factors which predominantly induce the MMP-9 production and increase invading cell numbers.

Influence of conditioned media from bovine cotyledon tissue cultures on function of bovine neutrophils

SUMMARY Bovine fetal placental (cotyledon) tissue obtained from pregnant cows on days 255, 265, and 275 of gestation, as well as immediately after parturition (n = 5) was incubated in media for 48 hours, and the incubation media were collected. Neutrophils from 4 ovariectomized nonpregnant cows were incubated for 2 hours with conditioned media from placental tissue cultures or medium (control). Immediately after incubation, the neutrophils were subjected to the following leukocyte function assays: chemotaxis against zymosan-activated serum, chemotaxis against undiluted conditioned media (only neutrophils that were incubated in medium only), random migration, ingestion of 125I-iododeoxyuridine Staphylococcus aureus (125I-IdUR-S aureus), iodination of proteins, cytochrome C reduction, and antibody-independent and -dependent cell-mediated cytotoxicity. Conditioned media from cultured cotyledon tissue was chemoattractant for bovine neutrophils, and increased chemotactic response of neutrophils against zymosan-activated serum by 13%. The following neutrophil functions were decreased: random migration by 25%, iodination of proteins by 44%, cytochrome C reduction by 13%, and antibody-dependent cell-mediated cytotoxicity by 5%. Ingestion of 125I-IdUR-S aureus and antibody-independent cell-mediated cytotoxicity were not influenced by coincubation of neutrophils and conditioned media. Time of gestation did not alter the effects of conditioned media on neutrophil function. It was concluded that chemotactic properties of cotyledon tissue extracts, as has been reported earlier, may be attributable to substances released by fetal placental tissue. Those substances might also locally or systemically influence the oxygen-dependent antimicrobial system of neutrophils, thereby causing an increased susceptibility to bacterial infections in the peripartum period.

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Medium conditioned by bovine arterial endothelial cells inhibited the degradation by human fibrosarcoma cells of living cultures of rat smooth muscle cells or their cell-free extracellular matrices. Endothelial cell-conditioned medium had no effect on the growth kinetics of fibrosarcoma cells, and the inhibitory influence of conditioned medium on matrix degradation was greatest with low numbers of tumor cells. Conditioned medium inhibited the production of tumor cell plasminogen activators, enzymes previously found to play a role in matrix glycoprotein degradation. The endothelial factor was heat- and acid-stable and non-dialyzable, and mixing experiments showed that it did not directly inactivate the tumor cell plasminogen activator. Endothelial cells may therefore modulate the production of proteolytic enzymes important in the implantation stage of tumor metastasis.

Enhancement of excision-repair efficiency by conditioned medium from density-inhibited cultures in V79 Chinese hamster cells: evidence for excision repair as an error-free repair process.

Conditioned medium from density-inhibited V79 Chinese hamster cell cultures, given as a post-treatment to UV-irradiated homologous cells, was demonstrated to reduce the lethal action of ultraviolet light by temporarily blocking DNA replication. Since the increased survival was not affected by various non-toxic concentrations of caffeine, such protective effect would be attributable to the prolonged intervention of excision repair before DNA replication during the post-treatment period. The influence of conditioned medium on the UV-induced mutation at the ouabain-resistance locus was also examined and a significant decrease in mutation frequency was noted. The observed reduction in killing and mutation as a result of post-incubation in conditioned medium, which delays DNA replication, would be interpreted as evidence that conditioned medium provides a longer period of time for an error-free excision-repair process, leaving lesion in DNA available for error-prone post-replication repair.

The influence of conditioned media and nonessential amino acid supplementation on the growth of cells in vitro.

AbstractThe growth enhancing effect of media conditioned by cells from established lines (BHK and L60) is comparable to that of media conditioned by cells of primary origin (chick embryo). However, the properties of the conditioned media from these two systems show marked differences: the growth enhancing factors in the former are dialyzable and heat‐stable, in contrast to the non‐dialyzable and heat‐labile factors in the latter.Media conditioned for only four hours by BHK or L60 cells stimulated cell growth. Amino acid analyses revealed that non‐essential amino acids had appeared in these conditioned media.To verify this as the metabolic basis of conditioning by cells from established lines, media containing dialyzed serum were supplemented with each of six non‐essential amino acids, and assayed on BHK and L60 at various population densities. Serine was the most stimulatory and alanine the most inhibitory of the amino acids tested.Mixed supplementation of the medium showed that when low levels of alanine and serine were added simultaneously, cell growth was enhanced but any increase in the level of alanine required an increase in the level of serine also to achieve growth stimulation.