Effects of 17beta-estradiol on matrix metalloproteinase-1 synthesis by human dermal fibroblasts

BACKGROUND

Hormone replacement therapy (HRT) has been used in treatment of various menopausal disorders. It has been well documented that HRT increases the amount of dermal collagen and skin thickness in vivo. However little is known about the effects of female sex hormones on dermal fibroblasts in vitro.

OBJECTIVE

The aim of this study is to determine whether or not 17beta-estradiol affects mRNA expression and production of type I collagen, matrix metalloproteinases-1 (MMP-1), tissue inhibitor metalloproteinases-1 (TIMP-1) or transforming growth factor-beta1 (TGF-beta1) by human dermal fibroblasts.

METHODS

Fibroblasts were cultured with and without 17beta-estradiol for 6h. We evaluated the changes of mRNA expressions and protein production of type I collagen, MMP-1, TIMP-1 and TGF-beta1.

RESULTS

The mRNA expressions of collagen alpha1(I), MMP-1, TIMP-1, TGF-beta1 were not changed by 17beta-estradiol stimulations at a concentration of 10(-12) to 10(-8) M. However, 17beta-estradiol at concentrations of 10(-12) and 10(-10) M exhibited inhibitory effects on proMMP-1, but not type I collagen or TIMP-1 synthesis. The synthesis of TGF-beta1 by fibroblasts stimulated with 10(-8) M of estradiol was significantly increased as compared with the control. However, the level of TGF-beta type II receptor phosphorylation was not elevated under the same conditions.

CONCLUSION

Suppressed synthesis of MMP-1 at a low concentration of 17beta-estradiol may be partly involved in the dermal tissue remodeling to inhibit the degradative change.

Antagonist-induced, activation function-2-independent estrogen receptor alpha phosphorylation

Estrogen receptor alpha (ERalpha) serine 118 (Ser118) phosphorylation modulates activation function-1 (AF1) function. Correct positioning of helix 12 promotes agonist-dependent recruitment of cyclin-dependent kinase-7 to catalyze this event. In this study we show robust cyclin-dependent kinase-7-independent, AF2 antagonist-induced Ser118 phosphorylation. Estradiol (E2) and ICI-182,780 (ICI-780) induce Ser118 phosphorylation of wild-type ERalpha and either of two helix 12 mutants, suggesting AF2-independent action, probably via shedding of 90-kDa heat shock protein. With E2 treatment, the predominantly nuclear, phosphorylated ERalpha in COS-1 cells is detergent soluble. Although levels of ICI-780-induced phosphorylation are profound, Ser118-phosphorylated ERalpha is aggregated over the nucleus or in the cytoplasm, fractionating with the cell debris and making detection in cleared lysates improbable. Selective ER modulators (SERMs) elicit a mixed response with phosphorylated ERalpha in both detergent-soluble and -insoluble compartments. Apparent ligand-induced loss of ERalpha protein from cleared lysates is thus due to ligand-induced redistribution into the pellet, not degradation. The COS-1 response to ICI-780 can be mimicked in MCF-7 cells treated with a proteasome inhibitor to block authentic ligand-induced degradation. With SERMs and antagonists, the magnitude of Ser118-phosphorylated receptor redistribution into the insoluble fraction of COS-1 cells correlates with the magnitude of authentic ERalpha degradation in MCF-7 cells. A strong inverse correlation with ligand-induced uterotropism in vivo (P < 0.0001) and direct correlation with AF2-independent transrepression of the matrix metalloprotease-1 promoter in endometrial cells in vitro are seen. These data suggest that ligand-induced Ser118 phosphorylation of ERalpha can be AF2 independent. Furthermore, they identify translocation of Ser118-phosphorylated ERalpha out of the nucleus, leading to cytoplasmic aggregation, as an antagonist pathway that may precede receptor degradation.

Production of exopolysaccharide from mycelial culture ofGrifola frondosaand its inhibitory effect on matrix metalloproteinase-1 expression in UV-irradiated human dermal fibroblasts

Exopolysaccharide (EPS) was prepared by submerged mycelial culture of a newly isolated mushroom Grifola frondosa HB0071 in a 5-l stirred-tank fermenter. This fungus produced a high concentration of biomass (24.8 gl(-1) at day 4), thereby achieving high EPS concentration (7.2 gl(-1) at day 4). EPS was proven to be a proteoglycan consisting of 85.6% carbohydrates (mostly glucose) and 7.3% proteins with a molecular weight of 1.0 x 10(6) Da. The photoprotective potential of EPS was tested in human dermal fibroblasts (HDF) exposed to ultraviolet-A (UVA) light. It was revealed that EPS had an inhibitory effect on human interstitial collagenase (matrix metalloproteinase, MMP-1) expression in UVA-irradiated HDF without any significant cytotoxicity. The treatment of UVA-irradiated HDF with EPS resulted in a dose-dependent decrease in the expression level of MMP-1 mRNA (by maximum 61.1% at an EPS concentration 250 microgml(-1)). These results suggest that EPS obtained from mycelial culture of G. frondosa HB0071 may contribute to inhibitory action in photoaging skin by reducing the MMP 1-related matrix degradation system.

Contrasting effects of fluoroquinolone antibiotics on the expression of the collagenases, matrix metalloproteinases (MMP)-1 and -13, in human tendon-derived cells

OBJECTIVES

Fluoroquinolone antibiotics may cause tendon pain and rupture. We reported previously that the fluoroquinolone ciprofloxacin potentiated interleukin (IL)-1beta-stimulated expression of matrix metalloproteinases (MMP)-3 and MMP-1 in human tendon-derived cells. We have now tested additional fluoroquinolones and investigated whether they have a similar effect on expression of MMP-13.

METHODS

Tendon cells were incubated for two periods of 48 h with or without fluoroquinolones and IL-1beta. Total ribonucleic acid (RNA) was assayed for MMP messenger RNA by relative quantitative reverse transcriptase polymerase chain reaction, with normalization for glyceraldehyde-3-phosphate dehydrogenase mRNA. Samples of supernatant medium were assayed for MMP output by activity assays.

RESULTS

MMP-13 was expressed by tendon cells at lower levels than MMP-1, and was stimulated typically 10- to 100-fold by IL-1beta. Ciprofloxacin, norfloxacin and ofloxacin each reduced both basal and stimulated expression of MMP-13 mRNA. In contrast, ciprofloxacin and norfloxacin increased basal and IL-1beta-stimulated MMP-1 mRNA expression. Both the inhibition of MMP-13 and the potentiation of MMP-1 expression by fluoroquinolones were accompanied by corresponding changes in IL-1beta-stimulated MMP output. The non-fluorinated quinolone nalidixic acid had lesser or no effects.

CONCLUSIONS

Fluoroquinolones show contrasting effects on the expression of the two collagenases MMP-1 and MMP-13, indicating specific effects on MMP gene regulation.

WAVE3 promotes cell motility and invasion through the regulation of MMP-1, MMP-3, and MMP-9 expression

WAVE3 is a member of the WASP/WAVE family of proteins, which play a critical role in the regulation of actin polymerization, cytoskeleton organization, and cell motility. We show here that knockdown of the WAVE3 protein, using RNA interference in MDA-MB-231 cells, decreases phospho-p38 MAPK levels, but not those of phospho-AKT, phospho-ERK, or phospho-JNK. Knockdown of WAVE3 expression also inhibited the expression levels of MMP-1, MMP-3, and MMP-9, but not MMP-2. MMP production could be restored by PMA treatment, without affecting siRNA-mediated WAVE3 knockdown. The WAVE3-mediated downregulation of p38 activity and MMP production is independent of the presence of both WAVE1 and WAVE2, whose expression levels were not affected by loss of WAVE3. We also show that the downstream effect of the WAVE3 knockdown is the inhibition of cell motility and invasion, coupled with increased actin stress fiber formation, as well as reorganization of focal adhesion complexes. These findings suggest that WAVE3 regulates actin cytoskeleton, cell motility, and invasion through the p38 MAPK pathway and MMP production.

Enhanced angiotensin II-mediated effects in fibroblasts of patients with familial hypercholesterolemia

OBJECTIVE

Familial hypercholesterolemia (FH) is characterized by a high incidence of coronary heart disease. Evidence suggests an important role for angiotensin II (AngII) in the fibrotic response to tissue injury, and in promoting myocardial hypertrophy via paracrine mechanisms mediated by fibroblasts. We sought to determine whether AngII promotes proliferative and pro-atherogenic responses in FH patients.

METHODS

We used primary fibroblasts -- from five patients with heterozygous FH and five control subjects (C) -- to study AngII-induced cell growth, intracellular calcium fluxes, and expression/release of matrix components and pro-inflammatory peptides [transforming growth factor-beta1 (TGFbeta1) and endothelin-1 (ET-1)] and metalloproteinases involved in plaque remodeling and vulnerability.

RESULTS

AngII stimulated cell replication (5.1 +/- 0.03 versus 3.2 +/- 0.04 cells/50 cells per well, P < 0.001), and induced a larger increase in intracellular calcium content in FH cells than in C cells, in a dose-dependent fashion (mean difference = 76 nmol/l, P < 0.001). Similarly, TGFbeta1 and ET-1 expression and release were potentiated (after 24-h incubation with 1 micromol/l AngII: TGFbeta1 was 190 +/- 12 in C and 376 +/- 9 pg/ml per 10(6) cells in FH, and ET-1 was 93 +/- 5 in C and 192 +/- 7 pmol/ml per 10(6) cells in FH; P < 0.001 for both). AngII-induced release of the metalloproteinases MMP-1 and MMP-2 was also increased in FH versus C cells (0.52 +/- 0.04 versus 0.36 +/- 0.05 and 24 +/- 4 versus 13 +/- 3 ng/mg protein with 1 micromol/l AngII). These enhanced responses were likely due to an increased angiotensin receptor 1 (AT1) expression in cells from FH patients induced by AngII, and were prevented by pretreating cells with the selective AT1 antagonist irbesartan.

CONCLUSIONS

These findings show that some AngII-mediated pathways are enhanced in FH subjects irrespective of the presence of low-density lipoprotein (LDL), thus contributing to the development and progression of atherosclerosis in these patients.

The effect of tiarellic acid on the expressions of matrix metalloproteinase-1 and type 1 procollagen in ultraviolet irradiated cultured human skin fibroblasts

Long term and repeated exposure of ultraviolet (UV) light, a harmful environmental stress, on the skin often induces chronic skin diseases such as skin cancer as well as photoaging (premature skin aging), and the mechanisms of these skin damages are closely associated with up-regulation of matrix metalloproteinases (MMPs) activities. Here we investigated the effect of tiarellic acid on the expressions of MMP-1 and type 1 procollagen in ultraviolet irradiation of cultured human skin fibroblasts. Tiarellic acid reduced the expression of MMP-1 and induced the expression of type 1- procollagen at the protein levels in a dose-dependent manner by ultraviolet irradiation. Taken together, our results suggest that tiarellic acid plays an important role in the reduction of MMP-1 and induction of type 1- procollagen by ultraviolet irradiation.

Beta-carotene inhibits UVA-induced matrix metalloprotease 1 and 10 expression in keratinocytes by a singlet oxygen-dependent mechanism

UVA exposure causes skin photoaging by singlet oxygen (1)O(2)-mediated induction of, e.g., matrix metalloproteases (MMPs). We assessed whether pretreatment with beta-carotene, a (1)O(2) quencher and retinoic acid (RA) precursor, interferes with UVA-induced gene regulation. HaCaT keratinocytes were precultured with beta-carotene at physiological concentrations (0.5, 1.5, and 3.0 microM) prior to exposure to UVA from a Hönle solar simulator (270 kJ/m(2)). HaCaT cells accumulated beta-carotene in a time- and dose-dependent manner. UVA irradiation massively reduced the cellular beta-carotene content. Beta-carotene suppressed UVA-induction of MMP-1, MMP-3, and MMP-10, three major matrix metalloproteases involved in photoaging. We show that regulation by not only MMP-1, but also MMP-10, involves (1)O(2)-dependent mechanisms. Beta-carotene dose-dependently quenched (1)O(2)-mediated induction of MMP-1 and MMP-10. Thus, as in chemical solvent systems, beta-carotene quenches (1)O(2) also in living cells. Vitamin E did not cooperate with beta-carotene to further inhibit MMP induction. HaCaT cells produced weak retinoid activity from beta-carotene, as demonstrated by mild upregulation of RAR beta and activation of an RARE-dependent reporter gene. Beta-carotene did not regulate the genes encoding other RARs, RXRs, or the two beta-carotene cleavage enzymes. These results demonstrate that beta-carotene acts photoprotectively, and that this effect is mediated by (1)O(2) quenching.

Retinoic acid receptor ? expression and cutaneous ageing

Intrinsic ageing of human skin is a subtle and gradual process that demonstrates few clinical or histological features until old age (>70 years). Initial work indicates that aged skin is "retinoid sensitive" but there is little data on the role of retinoic acid receptors (RARs) or retinoid X receptors (RXRs) in skin ageing. As nuclear retinoid receptors have been implicated in ageing in rodents, we studied the distribution of these receptors in intrinsically aged as compared to young, photoprotected human skin. We found that intrinsic ageing of skin in vivo is accompanied by significant increases of RAR alpha mRNA and protein whereas other isoforms show no alteration with age. In vitro transfection of COS-1 cells with the RAR alpha gene induces expression of matrix metalloproteinase-1 (MMP-1), an enzyme known to play an active role in remodelling of the dermis in intrinsically aged and photoaged skin. Furthermore, addition of all-trans retinoic acid (RA) to cultures of RAR alpha-transfected COS-1 cells diminishes RAR alpha and returns levels of MMP-1 to those approaching baseline. These results demonstrate that intrinsic ageing of human skin is accompanied by significant elevation in the content of RAR alpha and that over-expression of RAR alpha influences expression of MMP-1, an important mediator of skin ageing.

Identification of Benzene Metabolites in Dermal Fibroblasts as Nonphenolic: Regulation of Cell Viability, Apoptosis, Lipid Peroxidation and Expression of Matrix Metalloproteinase 1 and Elastin by Benzene Metabolites

The skin is exposed to benzene and its derivatives, prevalent environmental chemicals. They may impair the structural integrity of the skin by increased expression of matrix metalloproteinase 1 (MMP-1; degrades structural collagen) and elastin, synthesized primarily by the dermal fibroblasts. We examined the metabolism of benzene in dermal fibroblasts and identified the benzene metabolites as toluene, benzaldehyde, aniline and benzoic acid. These metabolites were not toxic to the cells with regard to cell viability, apoptosis and lipid peroxidation, unlike the phenolic benzene metabolites (hydroquinone, t-butyl hydroquinone and phenol) or hydrogen peroxide. Toluene and phenol, which compose cigarette smoke, and benzaldehyde stimulated MMP-1 and/or elastin expression. In summary, the dermal fibroblasts metabolize benzene to nonphenolic metabolites that are less toxic to the cellular components than the phenolic benzene derivatives. Toluene, benzaldehyde and phenol can directly cause facial wrinkling and impaired structural integrity by upregulating MMP-1 and/or elastin.

Cigarette smoke stimulates MMP-1 production by human lung fibroblasts through the ERK1/2 pathway

An imbalance between proteases and anti-proteases is believed to play an important role in the pathogenesis of emphysema. In this study, we explored the hypothesis that cigarette smoke can alter tissue structure through an effect on the release of matrix metalloproteinase-1 (MMP-1) and type I tissue inhibitor of metalloproteinases (TIMP-1). Cigarette smoke extract (CSE) significantly stimulated pro-MMP-1 production (determined by ELISA and immunoblots) and mRNA expression (by real-time RT-PCR) by human fetal lung fibroblasts (HFL-1) in a concentration-dependent manner (2.5-10%). High concentrations of CSE (10%) could potentially activate the latent form of MMP-1 as the high molecular weight (52 kDa) form was converted into a low molecular weight (42 kDa) form consistent with active MMP-1. TIMP-1 production, however, was not significantly altered by the concentrations of CSE tested. After 30 min exposure, CSE significantly induced ERK1/2 phosphorylation, which then gradually decreased from 90 minutes to 3 hours. PD98059, a specific inhibitor of ERK-MAPK, significantly blocked the CSE effect on ERK1/2 phosphorylation. Furthermore, PD98059 significantly inhibited the CSE effect on MMP-1 production and mRNA expression by fibroblasts. These results suggest that cigarette smoke stimulates production and likely activates MMP-1 through activating ERK1/2 signal transduction pathway. By inducing MMP-1, cigarette smoke may result in excess tissue destruction and contribute to the development of emphysema.

Regulation of matrix metalloproteinase-1 and tissue inhibitor of matrix metalloproteinase-1 by dichloroacetic acid in human fibroblasts from normal peritoneum and adhesions

OBJECTIVE

To examine the role of stimulation of aerobic metabolism on the differential expression of matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1), which are differentially regulated in fibroblasts isolated from normal human peritoneum and adhesions.

DESIGN

Tissue culture study.

SETTING

University research laboratory.

PATIENT(S)

Human fibroblasts cultures from normal peritoneum and adhesions that were exposed to dichloroacetic acid (DCA; 0 and 100 microg/mL) for 24 hours under normal and hypoxic conditions.

MAIN OUTCOME MEASURE(S)

Real-time reverse-transcription polymerase chain reaction of MMP-1, TIMP-1, and beta-actin.

RESULT(S)

Dichloroacetic acid stimulated peritoneal fibroblast MMP-1 mRNA expression under normoxic conditions; this stimulation was lost during hypoxia. In adhesion fibroblasts, DCA increased MMP-1 mRNA expression; this effect was reversed by hypoxia. Expression of TIMP-1 mRNA was insignificantly increased by DCA in normal peritoneal and adhesion fibroblasts under normoxic conditions; however under hypoxic conditions, DCA reduced TIMP-1 mRNA expression from both.

CONCLUSION(S)

Regulation of metabolic activity of peritoneal cells may provide a target for future interventions for reduction of development of postoperative adhesions, particularly as it relates to healing of peritoneal sites that did not previously have adhesions as opposed to sites that underwent lysis of preexistent adhesions.

The inhibition of MAPK pathway is correlated with down-regulation of MMP-9 secretion induced by TNF-alpha in human keratinocytes

MMP-9 (92 kDa) is the major gelatinase able to degrade collagen IV, secreted by keratinocytes that are actively involved in wound-healing or tumorigenesis. Since the invasive phenotype of cancers is dependent on MMP-9 expression, it appeared of interest to precisely characterize which signal transduction pathways activated by TNF-alpha are involved in MMP-9 up-regulation induced by TNF-alpha. In HaCaT cells, activation of MMP-9 occurs at the transcriptional level. Inhibition of the MAPK pathway using specific inhibitors of the Ras, Raf, MEK1/2, and Erk1/2 cascade was correlated with a marked inhibition of MMP-9 activity, as determined by gene and protein expression. MAPK pathway activation via TNF-alpha was confirmed by marked AP-1 activation detected in EMSA. Under our experimental conditions, p38 MAPK and SAPK/JNK pathways were not activated. Gene and protein expression of other MMPs that regulate MMP-9, such as MMP-1 and MMP-13, were also up-regulated by TNF-alpha and inhibited by UO126, providing evidence that the MAPK pathway plays a fundamental role in the regulation of MMP-9 secretion by keratinocytes. As TNF-alpha is known to be a main activator of NF-kappaB pathway, the effects of campthothecin and caffeic acid were investigated, such as, TNF-alpha campthothecin up-regulated MMP-9 activity but caffeic acid only weakly inhibited MMP-9 activation induced by TNF-alpha. However, NF-kappaB is activated as shown from immunostaining data, a nuclear staining and higher Western blotting expression of p50 and p65 NF-kappaB subunits were detected after TNF-alpha treatment. A higher specific signal was also detected in EMSA for TNF-alpha-treated cells.

Phosphinic acid-based MMP-13 inhibitors that spare MMP-1 and MMP-3

Phosphinic acid-based inhibitors of MMP-13 have been investigated with the aim of identifying potent inhibitors with high selectivity versus MMP-1. Independent variation of the substituents on a P(1)' phenethyl group and a P(2) benzyl group improved potencies in both cases around 3-fold over the unsubstituted parent. Combining improved P(1)' and P(2) groups into a single molecule gave an inhibitor with a 4.5 nM IC(50) against MMP-13 and which is 270-fold selective over MMP-1.

Involvement of FGF-2 in the action of Emdogain on normal human osteoblastic activity

OBJECTIVE

The present study was designed to evaluate the pharmacological characteristics of Emdogain (EMD) on cell growth and cell activity in human osteoblasts.

METHODS

Cell proliferation as well as several gene and protein expressions were examined using reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) procedures in human osteoblastic cells (SaM-1) treated with EMD (30 microg ml(-1)).

RESULTS

Treatment of osteoblasts with EMD significantly stimulated cell proliferation and fibroblast growth factor (FGF)-2 expression but decreased alkaline phosphatase expression. In addition, increases in cyclooxygenase (COX)-2 expression and decreases in matrix metalloproteinases (MMP)-1 expression were observed in osteoblasts treated with EMD. The effects of EMD on FGF-2 and MMP-1 expressions were not observed in osteoblasts treated with NS-398, an inhibitor of COX-2. The decrease in MMP-1 mRNA by EMD was prevented by treatment with antisense oligodeoxynucleotide (AS-ODN) for FGF-2.

CONCLUSION

Emdogain showing both stimulation of cell proliferation and inhibition of cell differentiation has been shown to increase FGF-2 expression in the mediation of prostaglandin E2 and to decrease MMP-1 mRNA expression through the activation of FGF-2. FGF-2 may underlie in the action of EMD on osteoblasts during periodontal regeneration.

PTHrP [67-86] regulates the expression of stress proteins in breast cancer cells inducing modifications in urokinase-plasminogen activator and MMP-1 expression

It was previously reported that a midregion domain of parathyroid hormone-related protein (PTHrP), that is, [67-86]-amide, is able to restrain growth and promote matrigel penetration by the 8701-BC cell line, derived from a biopsy fragment of a primary ductal infiltrating carcinoma of the human breast, and that cell invasion in vitro is drastically impaired by inactivation of urokinase-plasminogen activator (uPa). In this study we started a more detailed investigation of the possible effects on gene expression arising from the interaction between PTHrP [67-86]-amide and 8701-BC breast cancer cells by a combination of conventional-, differential display-and semi-quantitative multiplex-polymerase chain reaction (PCR) assays. We present here the first evidence that the upregulation of some stress-related genes, most noticeably heat shock factor binding protein-1 (hsbp1) and heat shock protein 90 (hsp-90), is involved in the acquisition of an in vitro more invasive phenotype by cells treated with midregion PTHrP. This is conceivably accomplished by sequestering and inactivating heat shock factor-1 (hsf1) which is able to recognize Ets transcription-factor-binding sites present in some gene promoters, such as those of uPa and matrix metalloprotease-1 (MMP-1). In fact, our data show that incubation of PTHrP [67-86]-amide-treated cells with either antisense hsbp1-oligonucleotide or geldanamycin, an hsp90-inactivating antibiotic, results in downregulation of uPa and upregulation of MMP-1, and in a prominent inhibition of cell invasion in matrigel-containing Transwell chambers. Alternatively, incubation of untreated 8701-BC cells with quercetin, a flavonoid known to decrease the amount of free hsf1, is found to induce upregulation of uPa and downregulation of MMP-1, and an increase of matrigel invasion by cells, thus providing further supporting data of the involvement of hsf unavailability on the modulation of uPa and MMP-1 expression and on cell invasive behaviour. These studies confirm a previous postulate that over-secretion of uPa, rather than of other extracellular proteases, is a primary condition for the increase of invasive activity triggered by PTHrP [67-86]-amide in vitro, and support a role for midregion forms of PTHrP in potentially affecting pathological mammary growth and differentiation. They also identify two new key protagonists in the complex scenario of breast tumor cell invasiveness in vitro, that is, hsbp1 and hsp90, which deserve further and more extensive studies as potential and attractive molecular targets for anti-breast cancer treatments.

Phosphocitrate inhibits calcium hydroxyapatite induced mitogenesis and upregulation of matrix metalloproteinase-1, interleukin-1beta and cyclooxygenase-2 mRNA in human breast cancer cell lines

Microcalcifications containing calcium hydroxyapatite (HA) are often associated with malignant human breast lesions. Frequently, they are the only mammographic features that indicate the presence of a tumoural lesion. We previously reported the induction of both mitogenesis and prostaglandin E2 (PGE2) production and the increased activities of matrix metalloproteinases (MMPs) MMP-2 and MMP-9 in normal human mammary epithelial cells and breast cancer cell lines, treated with HA. In the present study we attempted to elucidate the mechanism of these biological effects. Firstly, we found that direct cell-crystal contact was required for induction of mitogenesis as the effect was not merely a result of isotopic exchange of calcium into the culture medium. Treatment with bafilomycin A1, a proton pump inhibitor, abrogated HA-induced mitogenesis to control cell levels. These results suggest that phagocytosis and intracellular crystal dissolution is required for HA-induced mitogenesis. We also demonstrated that the increase in prostaglandin E2, previously reported, is due, at least in part, to HA-induced upregulation of cyclooxygenase-2 (COX-2) in Hs578T cells. An accumulation of MMP-1 mRNA was also shown in response to HA stimulation in Hs578T cells. Furthermore, a HA-induced increase in interleukin-1beta (IL-1beta), a potent inducer of MMP-1 gene expression, was demonstrated in Hs578T cells at 2 and 4 h. Treatment with phosphocitrate (PC) (a naturally occurring inhibitor of calcium phosphate crystallisation, which is known to block a number of HA-induced biological effects in other cell types) blocked HA-mediated mitogenesis, as well as, COX-2, MMP-1 and IL-1beta induction, at the transcriptional level. These results show that calcium HA crystals are capable of exerting significant biological effects on surrounding cells which can be abrogated by PC and emphasise the role of calcium HA in amplifying the pathological process involved in breast cancer.

Sarpogrelate HCl, a selective 5-HT2A antagonist, retards the progression of atherosclerosis through a novel mechanism

Although sarpogrelate HCl is widely used for the prevention of arterial thrombosis, its effect on atherosclerosis is unknown. Accordingly, we here investigated the effects of sarpogrelate HCl on a rabbit model of atherosclerosis. Male rabbits were fed a 0.5% cholesterol diet (HCD) (Gp 1), HCD with vitamin E (Gp 2), HCD with vitamin E and sarpogrelate (Gp 3), or HCD with sarpogrelate alone (Gp 4) for 8 weeks. The atherosclerotic area was decreased by feeding of vitamin E and sarpogrelate (16.9+/-2.0% in Gp 1 vs. 8.2+/-2.0% in Gp 3). Tone-related basal NO release was higher in Gps 3 and 4. Acetylcholine-induced relaxation tended to be improved in Gp 3. The amount of eNOS mRNA was increased in Gp 4, and aortic cyclic GMP concentration showed the same tendency. O(2)(-) release tended to be decreased in Gps 2 and 3. The matrix metalloproteinase-1 (MMP-1)-positive area was decreased, and the percentage ratio of cell numbers of smooth muscle cells/macrophages in the plaque was increased in Gp 3. The results demonstrated that sarpogrelate HCl retards the progression of atherosclerosis in rabbits, and that this effect is enhanced by concomitant administration of vitamin E. Although upregulation of eNOS may play a role as one of the underlying mechanisms, our results suggest that an additional mechanism-possibly involving the antiproliferative effects of sarpogrelate HCl on smooth muscle cells and macrophages-may also play an important role.

Effect of transforming growth factor-beta1, interleukin-6, and interferon-gamma on the expression of type I collagen, heat shock protein 47, matrix metalloproteinase (MMP)-1 and MMP-2 by fibroblasts from normal gingiva and hereditary gingival fibromatosis

BACKGROUND

Increased collagen and extracellular matrix deposition within the gingiva is the main characteristic feature of hereditary gingival fibromatosis (HGF). To date, it is not well established if these events are a consequence of alterations in the collagen and other extracellular matrix molecules synthesis or disturbances in the homeostatic equilibrium between synthesis and degradation of extracellular matrix molecules. Cytokines are important regulators of expression of the profibrogenic genes, including type I collagen and its molecular chaperone heat shock protein (Hsp)47 and proteolytic enzymes degrading extracellular matrix such as matrix metalloproteinases-1 and -2 (MMP-1 and MMP-2).

METHODS

In this study, we analyzed the expression and production of type I collagen, Hsp47, MMP-1, and MMP-2 in normal gingiva (NG) and HGF fibroblasts, and investigated the effects of transforming growth factor-beta1 (TGF-beta1), interleukin-6 (IL-6) and interferon-gamma (IFN-gamma) on the expression of these genes by NG and HGF fibroblasts.

RESULTS

Our results obtained from semi-quantitative reverse transcription-polymerase chain reactions (RT-PCR), Western blots, enzyme-linked immunosorbent assays (ELISA), and enzymographies clearly demonstrated that the expression and production of type I collagen and Hsp47 were significantly higher in fibroblasts from HGF than from NG, whereas MMP-1 and MMP-2 expression and production were lower in fibroblasts from HGF patients. Addition of TGF-beta1 and IL-6, which are produced in greater amounts by HGF fibroblasts, promoted an increase in type I collagen and Hsp47 and a decrease in MMP-1 and MMP-2 expression. IFN-gamma reduced both type I collagen and Hsp47 expression, whereas it had a slight effect on the expression of MMP-1 and MMP-2.

CONCLUSION

These patterns of expression and production suggest that enhanced TGF-beta1 and IL-6 production simultaneously increase the synthesis and reduce the proteolytic activities of fibroblasts from patients with HGF, which may favor the accumulation of extracellular matrix observed in patients with this condition.

Lipopolysaccharide induces interleukin-8 production by human cervical smooth muscle cells

OBJECTIVE

We examined the effect of lipopolysaccharide (LPS), a component of the outer wall of gram-negative bacteria, on expression of the neutrophil chemoattractant interleukin-8 (IL-8) and the effects of IL-8 treatment on release of matrix metabolizing enzymes in human cervical smooth muscle cells (CSMCs).

METHODS

Human CSMCs were exposed to Escherichia coli LPS, and the expression of IL-8 mRNA was analyzed by Northern blotting. The IL-8 promoter activity was examined by dual luciferase assay, and the IL-8 concentration was assessed by enzyme-linked immunosorbent assay. We also treated the CSMCs with human IL-8 and examined the expression of matrix-degrading enzymes.

RESULTS

E coli LPS (100 ng/mL) increased the expression of IL-8 mRNA 12.8-fold after 3 hours. This up-regulation was maintained for up to 24 hours. Lipopolysaccharide treatment produced a fivefold increase in IL-8 promoter activity in CSMCs transfected with an IL-8 promoter-reporter construct. IL-8 concentrations in conditioned medium of CSMC cultures treated with E coli LPS increased approximately 18-fold compared with the control cultures. Northern blot analysis and zymography revealed that exogenous human IL-8 had no significant effect on the expression of matrix metalloproteinase (MMP)-1, -3, and tissue inhibitor of metalloproteinase (TIMP)-1 mRNAs, and on the secretion MMP-2 and -9 in CSMCs.

CONCLUSION

We conclude that CSMCs respond to LPS with increased expression of IL-8 mRNA and secreted IL-8, and that expression of matrix metabolizing enzymes in CSMCs is not directly affected by IL-8. IL-8 produced by CSMCs in response to gram-negative infection may promote neutrophil invasion, and release of neutrophil matrix-degrading enzymes may participate in the matrix remodeling associated with parturition.

Treatment of rheumatoid tenosynovitis with cytokine inhibitors

Hand function depends on tendon integrity, but in rheumatoid arthritis tenosynovitis can result in tendon adhesions and rupture. Cytokine inhibitors have proved effective in rheumatoid joint disease; however, their effect on the tenosynovium is not well understood. We investigated the ability of inhibitors of tumour necrosis factor alpha and interleukin 1 to reduce production of collagenolytic matrix metalloproteinases 1 and 13 in tenosynovial tissue obtained from patients with rheumatoid arthritis. Our data show that cytokine blockade can reduce collagenase concentrations in tenosynovial tissue, suggesting cytokine inhibitors could be effective in reduction of tendon damage.

Evaluation of matrix metalloproteinase-1 and tissue inhibitor of metalloproteinase-1 levels in gingival fibroblasts of cyclosporin A-treated patients

BACKGROUND

Cyclosporin A (CsA) is a potent immunosuppressant used to prevent organ transplant rejection and to treat various autoimmune diseases. CsA-induced gingival overgrowth (CsA GO) is the most widely seen side effect of this drug; its pathogenesis is not completely understood. The aim of this study was to identify and compare matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) levels in gingival fibroblast cultures of tissues derived from renal transplant patients receiving CsA and exhibiting gingival overgrowth and from periodontally healthy control subjects.

METHODS

Gingival overgrowth samples were obtained from patients undergoing therapy with CsA, and control tissues were obtained from systemically healthy donors. Gingival fibroblasts were grown using explant cultures. Three different study groups were identified: 1) CsA GO fibroblast culture; 2) CsA-treated healthy gingival fibroblast culture (H+CsA); and 3) healthy gingival fibroblast culture (H). The levels of MMP-1 and TIMP-1 in these groups of gingival fibroblasts were analyzed by enzyme-linked immunoabsorbent assay (ELISA).

RESULTS

The levels of TIMP-1 were significantly lower in CsA GO than H (P < 0.05). There was no statistically significant difference in the levels of MMP-1 between H and CsA GO (P = 0.505). The ratio of MMP-1 to TIMP-1 was significantly higher in CsA GO than H (P < 0.05).

CONCLUSIONS

The results of this study indicate that CsA therapy does not have a significant effect on MMP-1 levels. However, low TIMP-1 levels can be an important factor in the pathogenesis of CsA GO, since the balance between MMP-1 and TIMP-1 levels was changed by CsA.

Medroxyprogesterone acetate versus norethisterone: effect on estradiol-induced changes of markers for endothelial function and atherosclerotic plaque characteristics in human female coronary endothelial cell cultures

OBJECTIVE

Progestin addition to estradiol (E(2)) replacement therapy may lead to a deterioration of beneficial effects on the vasculature. The effect of the two clinically most common progestins, medroxyprogesterone acetate (MPA) and norethisterone (NET), during continuous combination with E(2) on the synthesis of markers for coronary endothelial function, atherosclerotic plaque initiation, and plaque formation was investigated in human female vascular cell cultures and compared with that of E(2) alone.

DESIGN

Endothelial cell cultures from human female coronary arteries were used to evaluate the effect of progestin addition to E(2) on the production of the following endothelial markers: prostacyclin, endothelin, plasminogen activator inhibitor-1, E-selectin, intercellular adhesion molecule-1, monocyte chemoattractant protein-1 (MCP-1), and the precursor of matrix metalloproteinase-1 (pro-MMP-1). E(2) was tested at 0.1 microM, 1 microM, and 10 microM alone and in equimolar combinations with MPA or NET. The markers were determined by enzyme immunoassays in the cell supernatant.

RESULTS

E(2) induced a significant increase of endothelial prostacyclin production and was able to significantly decrease the synthesis of endothelin, plasminogen activator inhibitor-1, E-selectin, and intercellular adhesion molecule-1. Neither MPA nor NET addition negatively interfered with these E(2)-induced benefits. However, MPA antagonized the E(2)-induced significant reduction of MCP-1 synthesis, with the difference between both progestins being significant (p < 0.01). Interestingly, an enhancement of the positive E(2)-effect on pro-MMP-1 production was observed by the addition of both MPA and NET (p < 0.01).

CONCLUSION

E(2) can positively influence various markers of endothelial function. Addition of MPA or NET can elicit different effects, which has been demonstrated for the first time in human coronary cell cultures. No impact was found on markers representing primarily vasotonus and thrombogenicity. In terms of MMP-1, which is crucial for atherosclerotic plaque stability, an enhancement of the beneficial E(2) effect was observed. However, regarding MCP-1, contrary effects of progestins cannot be excluded. This indicates that progestins may differ in their effects, particularly in the early stages of atherosclerosis, which has also been supported by other studies.

Serum-dependent effects of IGF-I and insulin on proliferation and invasion of human first trimester trophoblast cell models

Extravillous cytotrophoblasts are specialised epithelial cells of the placenta that proliferate or invade the maternal decidua. Little is known about the mechanisms that regulate these processes. Here the effects of several insulin and insulin-like growth factor-I (IGF-I) doses, either singly or in synergy with serum, on human chorionic gonadotropin-beta (hCG-beta) secretion (RIA), proliferation (cell counting, cyclin B(1) levels) and invasion [Matrigel invasion assay, secretion of matrix metalloproteinases (MMP) 2 and 9] were investigated. The choriocarcinoma cell lines BeWo, JAR and JEG-3 served as models for first trimester human trophoblasts. Both growth factors altered hCG-beta secretion and proliferation dependent on the cell line. Insulin stimulated proliferation in JAR cells and, to a lesser extent, in JEG-3 cells, and when cultured in serum-free medium, BeWo was not affected. Invasion was not affected although proMMP-2 levels in culture medium were altered under some conditions. A strong synergistic effect with serum was noted. In the presence of serum both growth factors reduced proliferation and invasion in a similar fashion. Since the cell models differ by their degree of differentiation, the data demonstrate that the effects of insulin and IGF-I strongly depend on serum and the degree of differentiation. It can be speculated that IGF-I can take on tasks of insulin in the regulation of trophoblast functions under conditions of insulinopenia.

Interleukin-1beta and tumor necrosis factor-alpha induce chemokine and matrix metalloproteinase gene expression in human colonic subepithelial myofibroblasts

BACKGROUND

Colonic subepithelial myofibroblasts may play a role in the inflammatory responses and in extracellular matrix (ECM) metabolism. In this study, we investigated the effects of interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha on chemokine (IL-8 and monocyte chemoattractant protein (MCP)-1) and ECM turnover (proliferation of subepithelial myofibroblasts, and secretion of ECM and matrix metalloproteinases (MMPs)) in colonic subepithelial myofibroblasts.

METHODS

Human colonic subepithelial myofibroblasts were isolated using the method described by Mahida et al. Chemokine and MMP expressions were determined by ELISA and Northern blotting. Nuclear factor (NF)-kappaB and NF-IL6 DNA binding activities were evaluated by electrophoretic gel mobility shift assays (EMSA).

RESULTS

IL-1beta and TNF-alpha did not affect the proliferation of subepithelial myofibroblasts, but stimulated the secretion of types I and IV collagens weakly. Unstimulated subepithelial myofibroblasts secreted a large amount of MMP-2, but a small amount of IL-8, MCP-1 and MMP-1. IL-1beta and TNF-alpha both induced a dose- and time-dependent increase in IL-8, MCP-1 and MMP-1 secretion, and weakly stimulated MMP-2 secretion. IL-1beta and TNF-alpha both rapidly evoked NF-kappaB DNA-binding activity. The inhibition of NF-kappaB activation markedly blocked both IL-1beta- and TNF-alpha-induced IL-8 and MCP-1 mRNA expression, but did not affect MMP-1 mRNA expression.

CONCLUSIONS

These observations indicate that chemokine secretion and ECM metabolism are collectively regulated by the proinflammatory cytokines, IL-1beta and TNF-alpha, in colonic subepithelial myofibroblasts. Thus, colonic subepithelial myofibroblasts may play an important role in the pathophysiology of inflammation in the colon.