Conditioned Tissue Culture Media Research Articles

Naturally Occurring Follicle-Stimulating Hormone Glycosylation Variants

Follicle-stimulating hormone (FSH) is a member of the glycoprotein hormone family, which is a subfamily of the cystine knot growth factor superfamily [1,2]. The glycoprotein hormones are composed of heterodimeric glycoprotein subunits, a common α-subunit, and a hormone-specific β-subunit. While the α-subunit primary structure is identical for all glycoprotein hormones within the same species, the oligosaccharide populations differ in a hormone-specific manner [3–6]. Characterizing the oligosaccharides released from an α-subunit preparation can identify the hormone from which the subunit was derived [7]. There are 3 to 4 β-subunits in vertebrates, which combine with α-subunit to create either FSH, luteinizing hormone (LH), thyroid-stimulating hormone (TSH), or in primates and equids, chorionic gonadotropin (CG) [8]. As both glycoprotein hormone subunits are cystine knot proteins [9–11] the protein backbone is folded into a series of three loops, two relatively rigid hairpin loops on one side of the knot, designated L1 and L3, and a single, flexible loop on the other side [12], designated L2. Oligosaccharides are attached to all 3 loops in a subunit-specific pattern (Figure 1). FSH subunits possess two potential N-glycosylation sites on each subunit and all four are of the Asn-Xaa-Thr type, which exhibit very efficient carbohydrate attachment [13]. Indeed, the α-subunit is always glycosylated at both sites in all known glycoprotein hormones. Because FSH α and β subunits co-migrate during electrophoresis, it is difficult to detect missing N-glycans in this hormone. FSHβ-specific Western blots have revealed partial glycosylation in equine FSHβ, human FSHβ (hFSH β), rhesus FSH β, and Japanese macaque FSHβ [14–16]. During the past few years, we have studied partially glycosylated hFSH isolated from pituitary extracts, postmenopausal urine, and conditioned tissue culture medium containing recombinant hFSH. Each glycosylation site in hFSH is decorated with a population of N-glycans. When total glycans are removed from reduced, carboxy-methylated FSH subunits, 39–130 glycans are found in mass spectra. We have data from only one glycosylation site, αAsn52, which possessed 29 neutral core ions, and when decorated with various patterns of sialic acid grew to 109 unique glycan structures. Micro heterogeneity can affect electrophoretic mobility, for example, placental hCGα with hybrid and biantennary glycans migrated faster than pituitary hFSHα, with triantennary, biantennary and tetraantennary glycans, which complicated sorting out the hFSH variants that resulted from loss of one or more N-glycans [17].

Magnetic bead-based 28-plex immunoassay for the quantification of rhesus and cynomolgus monkey cytokines (65.30)

Abstract Non-human primates, such as rhesus and cynomolgus monkey share a similar biochemistry and metabolism to humans. These animals are therefore crucial model systems in a number of areas of biomedical research. To simplify cytokine profiling we have developed a 28-plex magnetic luminex bead-based cytokine immunoassay for the analysis of rhesus and cynomolgus monkey samples. Validated sample types include serum, plasma, and conditioned tissue culture medium. Analytes include: EGF, eotaxin, FGF basic, G-CSF, GM-CSF, HGF, IFN-γ, IL-1β, IL-1RA, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12 p40/p70, IL-15, IL-17, I-TAC, MDC, MIF, MIG, MIP-1α, MIP-1β, MCP-1, RANTES, TNF-α, and VEGF. The utility of the assay is demonstrated by determining cytokine profiles obtained with LPS-stimulated or PMA plus A23187-stimulated peripheral blood mononuclear cells (PBMCs) from rhesus monkeys and cynomolgus monkeys. Linearity of dilution experiments with tissue culture medium and serum produce R2 values of 0.98 and greater, while sample recovery routinely falls between 80 and 120%. Intra-assay and inter-assay precision is ≤10% CV. This multiplex monkey cytokine assay provides a very powerful tool for addressing cytokine profiling in non-human primates. 28 cytokines can be simultaneously analyzed from a single sample greatly simplifying and cutting cost of monkey cytokine analysis.

Rosiglitazone and Pioglitazone Alter Aromatase Kinetic Properties in Human Granulosa Cells

We have previously reported that, in human granulosa cells, thiazolidinediones rosiglitazone and pioglitazone inhibit estrogen synthesis by interfering with androgen binding to aromatase, without an effect on aromatase mRNA or protein expression. In the current paper, we explore the effects of rosiglitazone and pioglitazone on the aromatase enzyme kinetic properties in human granulosa cells. The cells were incubated with various concentrations of testosterone or androstenedione, with or without rosiglitazone or pioglitazone. Estradiol and estrone concentrations in the conditioned tissue culture medium were measured by radioimmunoassay or immunosorbent assay. When testosterone was used as substrate, rosiglitazone or pioglitazone inhibited the V max by 35% (P < 0.001) and 24% (P < 0.001), respectively. When androstenedione was used as substrate, both rosiglitazone or pioglitazone inhibited V max by 13% (P < 0.007). We conclude that rosiglitazone or pioglitazone has no effect on K m but inhibits V max of aromatase in human granulosa cells, therefore, acting as noncompetitive inhibitors.

Vitamin D Regulates Steroidogenesis and Insulin-like Growth Factor Binding Protein-1 (IGFBP-1) Production in Human Ovarian Cells

Vitamin D Receptor (VDR) is expressed in both animal and human ovarian tissue, however, the role of vitamin D in human ovarian steroidogenesis is unknown. Cultured human ovarian cells were incubated in tissue culture medium supplemented with appropriate substrates, with or without 50 pM-150 pM or 50 nM-150 nM of 1,25-(OH)2D3, and in the presence or absence of insulin. Progesterone, testosterone, estrone, estradiol, and IGFBP-1 concentrations in conditioned tissue culture medium were measured. Vitamin D receptor was present in human ovarian cells. 1,25-(OH)2D3 stimulated progesterone production by 13% (p<0.001), estradiol production by 9% (p<0.02), and estrone production by 21% (p<0.002). Insulin and 1,25-(OH)2D3 acted synergistically to increase estradiol production by 60% (p<0.005). 1,25-(OH)2D3 alone stimulated IGFBP-1 production by 24% (p<0.001), however, in the presence of insulin, 1,25-(OH)2D3 enhanced insulin-induced inhibition of IGFBP-1 production by 13% (p<0.009). Vitamin D stimulates ovarian steroidogenesis and IGFBP-1 production in human ovarian cells likely acting via vitamin D receptor. Insulin and vitamin D synergistically stimulate estradiol production. Vitamin D also enhances inhibitory effect of insulin on IGFBP-1 production.

Magnetic bead-based 28-plex immunoassay for the quantification of rhesus and cynomolgus monkey cytokines (144.34)

Abstract Non-human primates possess high degrees of homology with humans, and thus are crucial model systems in a number of areas of biomedical research (neuroscience, endocrinology, reproductive physiology, cardiovascular physiology, infectious diseases, vaccine and drug efficacy and safety). Monitoring complex cytokine profiles has proven to be invaluable in these various areas. Using the Luminex® xMAP® platform, Life Technologies has developed a 28-plex magnetic bead-based cytokine immunoassay for the analysis of rhesus monkey (Macaca mulatta) and cynomolgus monkey (Macaca fascicularis) samples. Validated sample types include serum, plasma, and conditioned tissue culture medium. Analytes include: EGF, eotaxin, FGF basic, G-CSF, GM-CSF, HGF, IFN-γ, IL-1β, IL-1RA, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12 p40/p70, IL-15, IL-17, I-TAC, MDC, MIF, MIG, MIP-1α, MIP-1β, MCP-1, RANTES, TNF-α, and VEGF. This magnetic-bead based assay is compatible with robotic washing systems, and thus may be fully automated. Total incubation time is 3.5 hours. The utility of the assay is demonstrated by determining cytokine profiles obtained with LPS-stimulated or PMA plus A23187-stimulated peripheral blood mononuclear cells (PBMCs) from rhesus monkeys and cynomolgus monkeys. Linearity of dilution experiments with tissue culture medium and serum produce R2 values of 0.98 and greater, while sample recovery routinely falls between 80 and 120%. Intra-assay and inter-assay precision is ≤10% CV.

Association of human, rat, and rabbit apolipoprotein E with ?-amyloid

In humans, apolipoprotein E (apoE) has three major isoforms, E2 (Cys112, Cys158), E3 (Cys112, Arg158), and E4 (Arg112, Arg158). While epsilon4 is a genetic risk factor for Alzheimer's disease (AD), epsilon2 may protect against late-onset AD. Using native preparations of apoE from conditioned tissue culture media or plasma lipoproteins, we have previously shown that when equivalent amounts of apoE3 or E4 were incubated with beta-amyloid (A beta), apoE3 formed 20 times as much SDS-stable complex with the peptide as apoE4. This preferential binding of A beta to apoE3 was abolished when apoE was purified by a process which includes delipidation and denaturation. Here we expand these observations to include A beta binding to lipoprotein-associated and purified apoE2. Lipoproteins isolated from the plasma of individuals homozygous for either epsilon2 or epsilon3 were incubated with A beta(1-40). SDS-stable complex formation was analyzed by a non-reducing gel shift assay, followed by immunoblotting with either A beta or apoE antibodies. ApoE2:A beta complex formation was comparable to apoE3:A beta in both native and purified preparations of apoE. In addition, lipoprotein-associated rat apoE (Arg112, Arg158), like human apoE4, did not form complex with A beta, while lipoprotein-associated rabbit apoE (Cys112, Arg158) did bind the peptide. These binding studies provide one possible explanation for protective effects of both apoE2 and E3 against the development of Alzheimer's disease.

Gelatinase activity and the occurrence of cerebral aneurysms.

Cerebral aneurysms are associated with decreased arterial collagen content; however, whether this deficiency results from impaired collagen synthesis or enhanced collagen degradation is unknown. This study tested the hypothesis that enhanced collagen degradation, not impaired collagen synthesis, is associated with the occurrence of cerebral aneurysms. Cultured skin fibroblasts and serum samples were studied in patients with angiographic evidence of aneurysm (n = 31) and control subjects (n = 14). Transcription of the type III collagen gene was assessed with the use of Northern blots prepared from RNA harvested from confluent cultured fibroblasts. Translation of type III collagen was assessed by Western blot analysis of proteins produced by cultured skin fibroblasts. Collagen metabolism was assessed by radioimmunoassay for type I (PICP) and type III (PIIINP) procollagen peptides in conditioned tissue culture media and serum. We assessed collagen degradation in serum and conditioned tissue culture media by evaluating gelatinase activity using quantitative zymography. Type III collagen synthesis was the same in aneurysm and control patients. Neither the molecular weight nor the relative amount of type III collagen mRNA differed between aneurysm and control patient fibroblasts. Western blot analysis revealed no difference in the relative amount or molecular weight of procollagen III synthesized by aneurysm and control cells. Aneurysm patients had a threefold increase in native serum gelatinase activity compared with control subjects (P = .004). This increase occurred along with serum evidence of increased collagen metabolism. Serum levels of PICP (P = .03) and PIIINP (P = .02) were decreased in aneurysm patients. Elevated serum gelatinase activity and altered collagen metabolism could not be explained by enhanced secretion of gelatinase by cultured fibroblasts or altered net collagen synthesis by fibroblasts. High serum gelatinase activity was more common in men than in women (P = .04). These findings are consistent with the hypothesis that accelerated enzymatic degradation of collagens and other structural proteins compromises the mechanical integrity of the cerebral vessel wall and leads to conditions that favor aneurysm formation.

Purification of tenascin from conditioned tissue culture media

We describe a purification procedure of human tenascin from conditioned medium of SK-MEL-28 melanoma cell line which involves the use of a hydroxyapatite chromatography column followed by polyethyleneglycol precipitation of crude tenascin eluted from the hydroxyapatite column. This procedure does not involve the use of specific antibodies and can thus be applied to culture media of cells of different species.

Response of three murine macrophage populations to particulate debris: Bone resorption in organ cultures

Particulate wear debris from bone cement or prosthetic components can stimulate macrophages to cause bone resorption. We compared the effect of particle composition (titanium and polymethylmethacrylate as inherent components of prosthetic materials or bone cement and polystyrene as a reference material) on the secretion of interleukin-1 and prostaglandin E2 by peritoneal macrophages and monocyte/macrophage cell lines (P388D1 and IC-21) and on the bone-resorbing activity of conditioned medium harvested from these particle-challenged macrophages. Titanium particles (1-3 microns) in peritoneal macrophage cultures exhibited significantly enhanced bone-resorbing activity measured as 45Ca release, whereas polymethylmethacrylate and polystyrene exhibited this effect to a greater extent in the P388D1 and IC-21 monocyte/macrophage cultures. Although exogenous prostaglandin E2 and recombinant human interleukin-1 could significantly increase the 45Ca release and indomethacin significantly reduced both the spontaneous calcium efflux and active 45Ca release from calvarial bones labeled in vivo, the levels of interleukin-1 and prostaglandin E2, alone or together, did not always correlate with the bone-resorbing activity of conditioned media. Thus, the actual levels of potent bone-resorbing agents (prostaglandin E2 and interleukin-1) measured in conditioned tissue culture media did not necessarily reflect the bone-resorbing capability. An important result of this study is that different macrophage populations may respond differently to the same microenvironmental signal, which in our investigation was particulate wear debris of differing composition and size.

In vitro bone resorption activity produced by a hypercalcemic adenocarcinoma tumor line (CAC-8) in nude mice.

Tumor extracts and conditioned tissue culture media from a canine adenocarcinoma tumor line (CAC-8) propagated in nude mice significantly increased in vitro bone resorption in neonatal mouse calvaria as measured by release of previously incorporated 45Ca. In vitro bone resorption activity was induced in a dose-dependent manner, was not suppressible by indomethacin, and was heat- and acid-stable. Gel exclusion chromatography demonstrated peak bone resorbing activity at a relative molecular mass of approximately 28,000. The parathyroid hormone (PTH) antagonist (8,18norleucine, 34tyrosine) bovine PTH (3-34) amide did not inhibit CAC 8-stimulated or (1-34) bPTH-induced bone resorption. There was an increased number of tartrate-resistant, acid phosphatase-positive cells in calvariae exposed to CAC-8 extract. Ultrastructural evaluation of calvaria revealed hypertrophy and maturation of osteoclasts in calvaria exposed to CAC-8 extract. The maturation effects included close contact to bone surfaces and the presence of clear zones and ruffled borders in osteoclasts. Similar structures were observed infrequently in osteoclasts of control calvaria. These data demonstrate that the tumor line (CAC-8) contained activity capable of stimulating in vitro bone resorption by increasing osteoclast numbers and the activity of existing osteoclasts.