Effect of gold sodium thiomalate on proliferation of human rheumatoid synovial cells and on collagen synthesis in tissue culture

Therapeutic effect of gold nanoparticles on DSS-induced ulcerative colitis in mice with reference to interleukin-17 expression

Ulcerative colitis (UC) is among the most challenging human diseases. Nanotechnology has incontestable promising outcomes in inflammatory bowel diseases. This study aimed to investigate the therapeutic effect of naked gold nanoparticles (AuNPs) on dextran sodium sulphate (DSS) induced ulcerative colitis in mice. We also examined the expression of interleukin-17 (IL-17) following AuNPs treatment. Mice were randomly divided into control, DSS and DSS+ AuNPs groups. Severity of colitis was assessed by disease activity index (DAI) measurement. At the end of the experiment, the final body weights were recorded. The colon was dissected and processed for histopathological examinations by light and electron microscopes. Colon homogenates were prepared for assay of tissue malondialdehyde (MDA) and real-time PCR analysis of IL-17A. Immunohistochemical localization of IL-17A was carried out. Scanning electron microscopy (SEM) and Energy Dispersive X-ray (EDX) detector were used to detect the presence of AuNPs in the colonic tissue of DSS+ AuNPs groups. Our results showed that AuNPs effectively targeted the colonic tissue, and reduced changes induced by DSS. The underlying mechanisms could be related to anti-oxidant effect (as evident by decreasing tissue MDA) and anti-inflammatory potential of AuNPs. Our study draws attention to as a novel therapeutic strategy for treating UC.

Gold nanoparticles: A critical review of therapeutic applications and toxicological aspects

Gold (Au) compounds have been utilized as effective therapeutic agents for the treatment of some inflammatory diseases such as rheumatoid arthritis. However, Au compound use has become limited due to associated high incidence of side effects. Recent development of nanomaterials for therapeutic use with Au-containing drugs is improving the beneficial actions and reducing toxic properties of these agents. Lower toxicity in conjunction with anti-inflammatory and antiangiogenic effects was reported to occur with gold nanoparticles (AuNP) treatment. However, despite this therapeutic potential, safety of AuNP remains to be determined, since the balance between therapeutic properties and development of adverse effects is not well established. Several variables that drive this benefit-risk balance, including physicochemical characteristics of nanoparticles such as size, shape, surface area, and chemistry, are poorly described in the scientific literature. Moreover, therapeutic and toxicological data were obtained employing nonstandardized or poorly described protocols with different experimental settings (animal species/cell type, route and time of exposure). In contrast, effective and safe application of AuNP may be established only after elucidation of various physicochemical properties of each specific AuNP, and determination of respective kinetics and interaction of compound with target tissue. This critical review conveys the state of the art, the therapeutic use, and adverse effects mediated by AuNP, with primary emphasis on anti-inflammatory and antiangiogenic potential, highlighting the limitations/gaps in the scientific literature concerning important points: (i) selection of experimental designs (in vitro and in vivo models) and (ii) consideration of different physicochemical properties of AuNP that are often disregarded in many scientific publications. In addition, prospects and future needs for research in this area are provided.

Interleukin-1 alpha modulates collagen gene expression in cultured synovial cells

The effects of porcine interleukin-1 (IL-1) alpha on collagen production were studied in cultured human rheumatoid synovial cells. Addition of 0.05-5 ng of IL-1/ml into the cultures resulted in a dose-dependent decreased rate of collagen released into the medium over 24 h. To determine whether this inhibition was due to secondary action of prostaglandin E2 (PGE2) secreted in response to IL-1, cultures were incubated in presence of various inhibitors of arachidonate metabolism. Depending on the cell strains, these inhibitors were able to suppress or diminish the effect of IL-1, suggesting that PGE2 is involved in the mechanism. Depression of collagen production caused by IL-1 mainly affected type I collagen and therefore led to a change in the type I/type III collagen ratio in the extracellular medium. Steady-state levels of mRNA for types I and III procollagens were estimated by dot-blot hybridization and compared with the amounts of respective collagens produced in the same cultures. IL-1 generally increased procollagen type I mRNA, but to a variable extent, as did indomethacin (Indo). Depending on the cell strain, the combination of indo and IL-1 could elevate the mRNA level of type I procollagen compared with Indo alone. These results did not correlate with the production rate of collagen in the medium, which was diminished by exposure to IL-1. The level of mRNA for collagen type III was not greatly changed by incubation with IL-1, and a better correlation was generally observed with the amount of type III collagen found in the medium. These data suggest that an additional control mechanism at translational or post-translational level must exist, counterbalancing the stimulatory effect of IL-1 on collagen mRNA transcription. It is likely that IL-1 could modulate the production of collagen in synovial cells by an interplay of different mechanisms, some of them limiting the effect of primary elevation of the steady-state mRNA level.

Rabbit articular chondrocytes: an in vitro model for studying the effect of sodium aurothiopropanol sulfonate on proliferation kinetics, type II collagen phenotype and mitochondrial activity

Despite the benefits of chrysotherapy the responsible mechanism of action of gold compounds remains unclear. At a concentration of 5 x 10(-4) M, sodium aurothiopropanol sulfonate (SAS) modified the in vitro proliferation kinetics of articular chondrocytes by reducing growth, viability and plating efficiency. Flow cytometry analysis, using propidium iodide DNA staining, revealed slight but significant cell arrest in G2+M which, in fact, represents an increase in the proportion of binucleate cells. SAS did not induce any variations in chondrocyte phenotype stability as far as the biosynthesis of type II collagen was concerned, and no appreciable changes in overall mitochondrial activity reflected by rhodamine 123 incorporation.

Practolol inhibits human skin fibroblast cell mat hydroxyproline accumulation

Despite being poorly absorbed practolol (N-4-2-hydroxy-3-(1-methyl-ethyl)-amino propoxy phenyl acetamine) inhibited the accumulation of cell mat hydroxyproline, a measure of collagen synthesis, by human skin fibroblasts (DT2PH) in vitro, (ID50 0.8 X 10(-3) M). The degree of inhibition was dependent on the concentration of practolol used and the incubation time. Neither preinitiation of collagen synthesis nor omitting ascorbic acid from the incubation medium modified this inhibitory action. In contrast, in vitro generated metabolites of practol, using normal and aroclor induced hamster liver preparation, and structural analogues of practolol had no effect on cell mat hydroxyproline levels. Related compounds, propranolol, (1-(isopropylamino)-3(1-naphthyl-oxy)2-propranolol), and paracetamol, (N-(4-hydroxyphenyl)acetamide), both inhibited hydroxyproline levels. Fibroblasts derived from uninvolved skin of a psoriasis patient (PS1) were several fold more sensitive to practolol and propranolol than cells derived from normal skin but showed little change in sensitivity towards paracetamol.

A cartilage-derived growth factor enhances hyaluronate synthesis and diminishes sulfated glycosaminoglycan synthesis in chondrocytes

Cartilage-derived growth factor purified to homogeneity by affinity chromatography on columns of heparin-Sepharose was mitogenic for early passage bovine fetal chondrocytes. Hyaluronate and sulfated glycosaminoglycan synthesis in these cells was analyzed by differential enzymatic digestion of the glycosaminoglycans labeled with [14C] glucosamine or [35S]. It was found that chondrocyte proliferation was accompanied by about a four-fold increase in hyaluronate synthesis over a two-day period, while the synthesis of sulfated glycosaminoglycans decreased by about 2-fold. Chromatographic analysis of the sulfated glycosaminoglycans showed decreases in chondroitin 4 and 6 sulfates. It was concluded from these results that cartilage-derived growth factor was a proliferative factor for chondrocytes and differed from the somatomedins.

Ploidity and cell cycle progression during treatment with gold chloride, auranofin and sodium aurothiomalate. Studies on a human epithelial cell line and its sub-strains made resistant to the antiproliferative effects of these gold compounds

The possible influence of gold(III) chloride and the two gold(I)-containing anti-arthritic drugs, auranofin and sodium aurothiomalate, on cellular ploidity and cell cycle progression was investigated on cultured human epithelial cells. Four different cell lines were used: the parent line (HE) and three sub-strains which previously had acquired resistance to the antiproliferative effects of either 350 mumol gold chloride/l culture medium (HEAu350), 2 mumol auranofin/l (HEAF) or 300 mumol sodium aurothiomalate/l (HEMyo). DNA-histograms were obtained by flow cytometry examinations during a 9-days' exposure to either of these gold-containing compounds and concentrations. The HE, HEAF and HEMyo cells had similar ploidities, close to tetraploid. The HEAu350 cells had altered ploidity to distinct tetraploid. The distribution of the resistant cells with the cell cycle phases was not different from that of untreated HE cells. The HE cells, when treated with auranofin or sodium aurothiomalate, accumulated in the G2-phase of the cell cycle. In addition, a new cedecoploid peak appeared. No such changes were observed on gold chloride exposure or in HE controls grown without drug supplement. The effects of auranofin and sodium aurothiomalate on cell cycle progression of the HE cells possibly indicate a tendency to polyploidity, and furthermore that inhibition of cellular mitosis is one mechanism of the antiproliferative effect common to the two drugs.

Developmental changes of proteoglycan synthesis in rat liver and isolated hepatocytes

The synthesis of sulfated proteoglycans in late fetal (19th to 22nd day of intrauterine life), early postnatal, and adult liver tissue as well as in hepatocytes and their distribution in plasma membranes were studied. Overall proteoglycan production is enhanced two-fold in fetal as compared with adult liver tissue. In contrast to slices from adult liver, in which the synthesis of heparan [35S]-sulfate comprises more than 80% and chondroitin sulfate less than 5% of total glycosaminoglycans, chondroitin [35S]sulfate is the major type of glycosaminoglycans synthesized in fetal liver representing about 50% of total sulfated glycosaminoglycans. Thus, the synthesis of chondroitin sulfate is elevated nearly 30-fold in fetal liver as compared with the adult counterpart. Immediately after birth chondroitin sulfate formation decreases rapidly reaching adult levels between the 10th and 15th day of postnatal life. The production of heparan sulfate is almost unchanged during perinatal liver development due to a relatively low fractional synthesis of heparan [35S]sulfate in fetal liver. Hepatocytes were identified as the cell type responsible for elevated chondroitin sulfate production in fetal liver. Erythroblasts, which synthesize chondroitin sulfate, contribute less than 10% to total glycosaminoglycan synthesis in embryonic liver. Plasma membranes of adult liver contain exclusively heparan sulfate whereas in neonatal liver cell membranes 25% of labeled glycosaminoglycans is represented by chondroitin sulfate, a fraction which decreases rapidly after birth. In parallel to the postnatal shut down of chondroitin sulfate synthesis the activity of the UDPxylose:coreprotein xylosyltransferase (EC. 2.4.2.26) decreases from 4.8 +/- 0.5 dpm/h per microgram protein to 0.3 +/- 0.1 dpm/h per microgram protein suggesting a regulatory function of the enzyme for proteochondroitin sulfate synthesis in developing liver. The formation of both heparan sulfate and chondroitin sulfate is dependent on functioning protein synthesis, which indicates, together with double labeling experiments using [3H]serine and [14C]glucosamine as isotopic precursors, their synthesis as proteoglycans. The positive correlation (r = 0.949) between the incorporation of [3H]thymidine into DNA and chondroitin [35S]sulfate production supports the assumption of a cell growth promoting activity of chondroitin sulfate and points to a significant role of the glycosaminoglycan in the process of cellular proliferation and tissue differentiation.

Characterization of human bone cells in culture

Cultures of human bone cells were established, maintained, and characterized with respect to several metabolic parameters. These studies were undertaken with a view to using the bone culture system as a means of studying mechanisms of bone metabolism. The donor patients' ages ranged from 1 to 90 years and their disease states included congenital limb anomalies, exostosis, and osteo- and rheumatoid arthritis. Cultures were maintained up to 5 months. The osteoblast-like character of these cells was confirmed with the use of measurements applied to bone cells from other systems. Analyses showed that (a) the cells' appearance resembled that of cultured osteoblasts from other animal sources, b) intracellular cAMP was stimulated by human parathyroid hormone, c) osteocalcin was detected in the medium of all tested bone cell cultures and its production was found to be stimulated by 1,25-dihydroxycholecalciferol, and d) newly synthesized collagen was almost exclusively type I. In contrast, cultures of human fibroblasts, established in one instance from tissue specimens of the same donor patient, grew faster, reached a higher limiting density, and produced a greater proportion of type III collagen than the corresponding bone cells. Furthermore, fibroblasts did not accumulate osteocalcin in their culture medium. The conditions described in this report to maintain human bone cells in culture should provide a suitable test system to study the regulation of human bone metabolism.

Mononuclear cell-conditioned medium containing mononuclear cell factor (MCF), homologous with interleukin 1, stimulates collagen and fibronectin synthesis by adherent rheumatoid synovial cells: effects of prostaglandin E2 and indomethacin

Adherent rheumatoid synovial cells produce and release into supernatant culture medium latent collagenase and PGE2. The levels of collagenase and PGE2 can be increased by a soluble factor present in mononuclear cell-conditioned medium, partially purified by gel-filtration, which has homologies with interleukin 1, and is produced by monocyte/macrophages. The synovial cell cultures produce collagens (procollagens) and fibronectin as well. The factor(s) present in the mononuclear cell conditioned medium which increases medium levels of collagenase PGE2 also stimulates synthesis of total protein as well as types I and III procollagen by the synovial cells. This stimulation by the monocyte factor is augmented in the presence of indomethacin, which blocks endogenous PGE2 production. Medium levels of fibronectin parallel those of procollagen. The addition of exogenous PGE2 abolishes the effect of indomethacin on collagen and fibronectin synthesis. These observations of mononuclear cell-mediated increases in fibronectin synthesis may account for the high levels of fibronectin found by others in rheumatoid synovium and synovial fluids as the increases in collagen synthesis might also explain the fibrosis observed in some rheumatoid joints.

Effect of heavy metals on human rheumatoid synovial cell proliferation and collagen synthesis

The dose-dependent effects of heavy metals on cell proliferation, collagen synthesis, and non-collagen protein synthesis were studied in early passage cultures of human synovial cells exposed to 1-100 microM concentration of gold, silver, mercury, cadmium or lead for 5 days. The incorporation of [3H]thymidine into trichloroacetic acid insoluble material was inhibited 50% by each of the heavy metals at concentrations between 1 and 10 microM. Gold, lead and mercury (10 microM) decreased the DNA content of the cultures by less than 15%; silver (10 microM) and cadmium (10 microM) resulted in decreased DNA content, which was attributed to cytotoxicity. A dose-dependent inhibition of [3H]proline incorporation into bacterial collagenase resistant (non-collagen) protein was observed after incubation with 10 microM mercury, lead and silver. During incubations with 10 microM gold and cadmium, collagenase resistant protein accumulation increased. All the heavy metals except for gold inhibited collagen accumulation to a greater extent than non-collagen protein accumulation. Gold (10 microM) stimulated the amount of collagen produced per cell, and the percentage of collagen to total protein was increased 50%. The rate of collagen accumulation in medium decreased during incubation with 10 microM silver, mercury, cadmium and lead. The stimulation of collagen synthesis may be a unique property of gold related to the therapeutic indices of gold, compared to other heavy metals, in rheumatoid arthritis.

Anti-proliferative properties of Clozic, a disease-modifying anti-arthritic agent

Cytostatic drugs have been used in the treatment of rheumatoid arthritis but are of limited clinical application due to their severe toxic side-effects. We have discovered that 'Clozic' (ICI 55897), an agent with disease-modifying properties in rheumatoid arthritis patients, inhibits the growth of a variety of mammalian cell types including a matrix-secreting cell culture derived from neonatal rat hearts. The inhibition of growth was reversible and no loss of cell viability occurred when measured by lactate dehydrogenase released into the medium or by vital staining, suggesting a cytostatic rather than a cytotoxic mechanism. Cytostatic activity was observed at ICI 55897 concentrations within the reported therapeutic plasma concentration range and was related to the concentration of unbound compound, since the effect could be reduced by increasing the albumin concentration in the medium. Other oxyalkanoic acids inhibited cell growth. Their inhibitory potency correlated with lipophilicity. The anti-proliferative potencies of R and S enantiomers of two oxyalkanoic acids containing asymmetric centres were similar. These observations suggest that the anti-proliferative effect of the oxyalkanoic acids is due to their interaction with lipophilic cell target sites.

Relationship of cell growth to collagen synthesis in glucocorticoid treated A/J and C57BL6/J neonatal mouse dermal fibroblasts

Primary cultures of neonatal dermal fibroblasts from two strains of mice (A/J and C57BL6/J) were utilized as an in vitro system to investigate the effects of glucocorticoids on cell growth and collagen synthesis. Protein and DNA synthesis were lower in untreated (control) A/J fibroblasts than in C57BL6/J fibroblasts. Treatment with glucocorticoids for 4 days resulted in dose-dependent inhibition of [3H]thymidine incorporation into DNA and a reduction in collagen synthesis. Collagen synthesis was differentially more susceptible to glucocorticoids than was total protein synthesis. Neonatal dermal fibroblasts obtained from A/J mice were more sensitive to glucocorticoids than were cells from C57BL6/J mice. Reduction in collagen production by anti-inflammatory steroids in this system may be related to adverse effects observed in vivo following treatment with these steroids.

The effect of lymphokines on proliferation and collagen synthesis of cultured human synovial cells

Human mononuclear cell supernatants were obtained by incubating 3 X 10(6) cells per ml of Dulbecco's modified Eagles medium at 37 degrees C for 24 h or 48 h, either in presence or absence of phytohaemagglutinin. After removal of intact cells, the supernatants were dialysed and diluted (1:1, 1:2, 1:5, 1:10) again using the above medium. The diluted supernatants, containing a final concentration of 10% (v/v) human platelet-factor poor serum, were found to stimulate the proliferation of human synovial cells in culture and to increase both the total amount of collagen and the percentage of Type III collagen synthesized by these cells. Incubation of the mononuclear cells in presence of phytohaemagglutinin appeared to further enhance the stimulatory effects of the supernatants upon the synovial cells. Since activated mononuclear leucocytes such as lymphocytes and macrophages are present in rheumatoid synovia, this study suggests that factors released from activated mononuclear leucocytes may play an important role in the proliferation of rheumatoid synovial tissue and development of the pannus.