Effects of different coating materials on the morphological characteristics of chicken adenohypophyseal folliculo-stellate cells in vitro.

Chicken adenohypophyseal cells were cultured in plates coated with different materials, and their morphologies were examined to confirm the characteristics of chicken folliculo-stellate (FS) cells in vitro. The adenohypophyseal cells were dispersed with a collagenase/trypsin mixture in media and seeded in plates coated in either poly L-lysine (PLL), collagen, or laminin. After 7 days of culture, the cells were fixed and immunocytochemistry was performed. 5-Bromo-2'-deoxyuridine incorporation test indicated that the proliferation activity of the culture cells was different based on the coating materials, and it was higher in the collagen-coated plate than two other coating materials. Fluorescence immunocytochemistry was also performed using mixed antibodies against growth hormone, prolactin, luteinizing hormone ß-subunit, basic cytokeratin (bCK), and S100B. The culture cells on the PLL- and laminin-coated surfaces were round or oval in shape, and bCK-immunopositive FS cells were morphologically indistinguishable from endocrine cells. In the collagen-coated plate, many endocrine cells were round or oval in shape, but FS cells displayed a larger and flattened morphology. S100B-immunoreactions were localized in the nuclei of bCK-immunopositive FS cells. These results suggest that culturing the chicken adenohypophyseal cells in the collagen-coated plate enables the distinction of FS cells from endocrine cells.

Chondroitin sulfate E downregulates N-cadherin and suppresses myotube formation.

Myogenesis, the formation of muscle fibers, is affected by certain glycoproteins, including chondroitin sulfate (CS), which are involved in various cellular processes. We aimed to investigate the mechanism underlying CS-E-induced suppression of myotube formation using the myoblast cell line C2C12. Differentiated cells treated with 0.1 mg/ml CS-E for nine days showed multinucleated and rounded myotubes with myosin heavy chain positivity. No difference was found between the CS-E-treated group with rounded myotubes and CS (-) controls with elongated myotubes in the levels of phospho-cofilin, a protein involved in the dynamics of actin cytoskeleton. Interestingly, N-cadherin, which is involved in the gene expression of myoblast fusion factors (myomaker and myomixer), was significantly downregulated at both the mRNA and protein levels following CS-E treatment. These results suggest that N-cadherin downregulation is one of the mechanisms underlying the CS-E-induced suppression of myotube formation.

Atorvastatin preferentially inhibits the growth of high ZEB-expressing canine cancer cells.

The epithelial-to-mesenchymal transition (EMT) is fundamental in cancer progression and contributes to the acquisition of malignant properties. The statin class of cholesterol-lowering drugs exhibits pleiotropic anticancer effects in vitro and in vivo, and many epidemiologic studies have reported a correlation between statin use and reduced cancer mortality. We have shown previously that sensitivity to the anti-proliferative effect of statins varies among human cancer cells and statins are more effective against mesenchymal-like cells than epithelial-like ones in human cancers. There have only been few reports on the application of statins to cancer therapy in veterinary medicine, and differences in statin sensitivity among canine cancer cells have not been examined. In this study, we aimed to clarify the correlation between sensitivity to atorvastatin and epithelial/mesenchymal states in 11 canine cancer cell lines derived from mammary gland, squamous cell carcinoma, lung, and melanoma. Sensitivity to atorvastatin varied among canine cancer cells, with IC50 values ranging from 5.92 to 71.5 µM at 48 h, which were higher than the plasma concentrations clinically achieved with statin therapy. Atorvastatin preferentially attenuated the proliferation of mesenchymal-like cells. In particular, highly statin-sensitive cells were characterized by aberrant expression of the ZEB family of EMT-inducing transcription factors. However, ZEB2 silencing in highly sensitive cells did not induce resistance to atorvastatin. Taken together, these results suggest that high expression of ZEB is a characteristic of highly statin-sensitive cells and could be a molecular marker for predicting whether cancers are sensitive to statins, though ZEB itself does not confer statin sensitivity.

Estrogen modulates the skeletal muscle regeneration process and myotube morphogenesis: morphological analysis in mice with a low estrogen status.

The purpose of this study was to elucidate the functions of estrogen and two estrogen receptors (ERs; ERα and ERß) in the myoregeneration process and morphogenesis. Cardiotoxin (CTX) was injected into the tibialis anterior (TA) muscles of ovariectomized (OVX) mice to induce muscle injury, and subsequent myoregeneration was morphologically assessed. The diameter of regenerated myotubes in OVX mice was significantly smaller than that in intact mice at all time points of measurement. OVX mice also showed lower muscle recovery rates and slower speeds than did intact mice. ER protein levels showed a predominance of ERß over ERα in both intact and OVX states. The ERß level was increased significantly at 7 days after CTX injection in OVX mice and remained at a high level until 14 days. In addition, continuous administration of E2 to OVX mice in which muscle injury was induced resulted in a significantly larger diameter of regenerated myotubes than that in mice that did not receive estrogen. The results indicate that estrogen is an essential factor in the myoregeneration process since estrogen depletion delayed myoregeneration in injured muscles and administration of estrogen under the condition of a low estrogen status rescued delayed myoregeneration. The results strongly suggested that ERß may be a factor that promotes myoregeneration more than does ERα.

Concomitant attenuation of HMGCR expression and activity enhances the growth inhibitory effect of atorvastatin on TGF-ß-treated epithelial cancer cells.

Epithelial-mesenchymal transition (EMT) in primary tumor cells is a key prerequisite for metastasis initiation. Statins, cholesterol-lowering drugs, can delay metastasis formation in vivo and attenuate the growth and proliferation of tumor cells in vitro. The latter effect is stronger in tumor cells with a mesenchymal-like phenotype than in those with an epithelial one. However, the effect of statins on epithelial cancer cells treated with EMT-inducing growth factors such as transforming growth factor-ß (TGF-ß) remains unclear. Here, we examined the effect of atorvastatin on two epithelial cancer cell lines following TGF-ß treatment. Atorvastatin-induced growth inhibition was stronger in TGF-ß-treated cells than in cells not thusly treated. Moreover, treatment of cells with atorvastatin prior to TGF-ß treatment enhanced this effect, which was further potentiated by the simultaneous reduction in the expression of the statin target enzyme, 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR). Dual pharmacological targeting of HMGCR can thus strongly inhibit the growth and proliferation of epithelial cancer cells treated with TGF-ß and may also improve statin therapy-mediated attenuation of metastasis formation in vivo.

Absence of estrogen receptors delays myoregeneration and leads to intermuscular adipogenesis in a low estrogen status: Morphological comparisons in estrogen receptor alpha and beta knock out mice.

This study aimed to investigate the function of estrogen receptors (ERs) in myoregeneration and intermuscular adipogenesis. Ovariectomized (OVX) ERα knockout (KO) mice and ERß KO mice were used to assess the effect of estrogen on the myoregenerative process. Tibialis anterior muscle was collected on days 7, 10, and 14 after cardiotoxin injection to assess myotube morphology and adipogenesis area. Regenerated myotubes from OVX-ERß KO mice were consistently smaller in diameter than those from OVX-ERα KO and OVX-wild-type mice, whereas the adipogenesis area of OVX-ERß KO mice was consistently greater than that of the other types. Therefore, ERß may be an influential factor in promoting myoregeneration and adipogenesis inhibition compared to ERα.

Concomitant attenuation of HMG-CoA reductase expression potentiates the cancer cell growth-inhibitory effect of statins and expands their efficacy in tumor cells with epithelial characteristics.

HMG-CoA reductase (HMGCR) inhibitors, statins, are potent cholesterol reducing drugs that exhibit anti-tumor effects in vitro and in animal models, including attenuation of metastasis formation, and their use correlates with reduced cancer-specific mortality in retrospective human cohort studies. However, E-cadherin expressing epithelial- and mixed epithelial-mesenchymal cancer cell lines (reflective of primary and outgrowing metastatic tumor cells, respectively) require higher statin concentrations than mesenchymal-like tumor cells (reflective of in-circulation metastatic tumor cells) to achieve the same degree of growth inhibition. Here, we show that attenuation of HMGCR expression in the presence of atorvastatin leads to stronger growth inhibition than dual target blockade of the mevalonate pathway in relatively statin resistant cell lines, mainly through inhibition of protein prenylation pathways. Thus, combined inhibition of the mevalonate pathway's rate-limiting enzyme, HMGCR, can improve atorvastatin's growth inhibitory effect on epithelial- and mixed mesenchymal-epithelial cancer cells, a finding that may have implications for the design of future anti-metastatic cancer therapies.

Immunohistochemical localization of osteoblast activating peptide in the mouse kidney.

Osteoblast activating peptide (OBAP) is a newly discovered peptide detected in the rat stomach, which has a major role in osteogenesis. Recently, we revealed its localization in the parietal cells of the rat stomach. There have been no data regarding OBAP expression in the kidney, despite its role in calcium reabsorption in renal tubules. The current study aimed to inspect the expression of OBAP in the kidney of twelve 10-week-old male C3H/HeNJc1 mice using immunohistochemistry, and immunoelectron microscopic localization. The immunohistochemical investigation revealed an OBAP positive reaction mainly in the medulla, which was stronger than the cortex of the kidney and was concentrated in the distal convoluted tubules (DCT), connecting tubules (CT), and the thick limbs of the loop of Henle (HL). Moreover, we clarified that the OBAP was co-distributed with ghrelin and calbindin (markers of the DCT). Interestingly, immunoelectron microscopy demonstrated that OBAP was concentrated in the mitochondrial inner membrane of the DCT and CT. Based on these results, it was concluded that the mitochondria of the DCT, CT, and HL of the mice kidney generate OBAP. Furthermore, our results suggest that OBAP might have a role in the regulation of calcium reabsorption by the renal tubule; however, further investigations are required to clarify this potential role.

Spatial distribution of osteoblast activating peptide in the rat stomach.

Osteoblast activating peptide (OBAP) was previously reported to be expressed in the rat stomach and to have a vital role in osteogenesis, but its distribution in rat stomach has not been determined. Thus, the aim of the present study was to identify the cell types expressing OBAP in the rat stomach. The stomachs of twelve 10-to-11-week-old male Jc1:SD rats were used. Samples were collected for immunohistochemistry, immunoelectron microscopy and dot blot assay. Immunohistochemical investigation revealed that OBAP was distributed mainly in parietal cells without any expression in chief cells, X/A-like cells or enterochromaffin-like cells. Moreover, OBAP-immunopositive cells were observed mainly in the upper and lower parts of the gastric gland. Significantly high optical density of immunopositive cells was observed in the upper and lower gastric gland regions. The dot blot assay confirmed that OBAP is secreted by parietal cells and that it is present in the gastric gland lumen. Immunoelectron microscopy demonstrated that OBAP was confined to the mitochondrial inner membrane within parietal cells and that the number of mitochondria in the upper and lower parts of the gastric epithelium was significantly larger than the number in the middle part of the gastric epithelium. Based on the results, it was concluded that OBAP is mainly produced by mitochondria of parietal cells in the upper and lower parts of the gastric epithelium. Moreover, the presence of OBAP in the gastric gland lumen suggests an exocrine mechanism of release.

Diamond squid (Thysanoteuthis rhombus)-derived chondroitin sulfate stimulates bone healing within a rat calvarial defect.

Chondroitin sulfate (CS) has been suggested to be involved in bone formation and mineralization processes. A previous study showed that squid-derived CS (sqCS) has osteoblastogenesis ability in cooperation with bone morphogenetic protein (BMP)-4 in vitro. However, in vivo, osteogenic potential has not been verified. In this study, we created a critical-sized bone defect in the rat calvaria and implanted sqCS-loaded gelatin hydrogel sponges (Gel) into the defect with or without BMP-4 (CS/BMP/Gel and CS/Gel, respectively). At 15 weeks, bone repair rate of CS/Gel-treated defects and CS/BMP/Gel-treated defects were 47.2% and 51.1%, respectively, whereas empty defects and defects with untreated sponges showed significantly less bone ingrowth. The intensity of von Kossa staining of the regenerated bone was less than that of the original one. Mineral apposition rates at 9 to 10 weeks were not significantly different between all treatment groups. Although bone repair was not completed, sqCS stimulated bone regeneration without BMP-4 and without external mesenchymal cells or preosteoblasts. Therefore, sqCS is a promising substance for promotion of osteogenesis.

Tumor suppressor candidate TUSC3 expression during rat testis maturation.

Analysis of microarray data obtained by comparing gene expression between 2-week-old infant and 7-week-old mature SD rat testes revealed novel targets involved in tumor suppression. Reverse-transcription polymerase chain reaction and Northern blotting indicated that Tusc3 gene expression was upregulated in the normal maturing testis and prostate and other organs such as the cerebrum and ovary. Tumor suppressor candidate 3 protein expression was detected in these same organs at a size of about 40 kDa, in accord with the predicted molecular size. In situ hybridization and immunohistochemistry showed that mRNA and protein localization were prevalent in the testis spermatocytes and interstitial cells such as the Leydig cells, as well as prostate epithelial cells. These data suggest that TUSC3 is deeply involved in spermatogenesis in the testis, inducing sperm differentiation and maturation, and plays a role in normal prostate development and tumor suppression.

Rat stem-cell leukemia gene expression increased during testis maturation.

We found that stem-cell leukemia (SCL), also known as T cell acute-lymphocytic leukemia (Tal-1) gene expression, was upregulated in the maturing rat testis. Strong expression of Tal-1 was detected in the normal maturing rat testis by Northern blotting. Western blotting revealed the protein size to be about 34 kDa. Protein expression was wide-spread in spermatocytes, spermtids and spermatogonia in accordance with the seminiferous epithelium cycle, as determined by an analysis of immunohistochemistry. Gene expression of Tal-1 regulatory gene, NKX3.1, was negatively correlated with Tal-1 expression. Human Tal-1 expression in the maturing testis as well as in bone marrow was observed, which suggests that the gene product is a novel cancer-testis antigen candidate. Taken together, TAL-1 may be involved in cell division, morphological changes, and the development of spermatogenic cells in the normal rat testis.

Efficacy of self-assembled hydrogels composed of positively or negatively charged peptides as scaffolds for cell culture.

KASEA16(+) and KASEA16(-) peptides, the net charges of which are positive and negative, respectively, under a neutral condition could undergo self-assembly into nanofibers and form transparent hydrogels without peptide aggregation upon rapid pH neutralization. The numbers of NIH3T3 cells attached to the KASEA16(+) hydrogel and KASEA16(-) hydrogel were similar, and cells proliferated with time on both hydrogels. Cells on the KASEA16(+) hydrogel had spindle-like morphology, while cells on the KASEA16(-) hydrogel formed clusters without extending cytoplasmic processes. Comparison of differently charged peptides under a neutral condition suggested that the charges of the scaffolds should be taken into consideration for the best design and selection of scaffolds for cell culture. Since the KASEA16(+) peptide could form a stable hydrogel under a neutral condition and the hydrogel served as a scaffold for cell proliferation, the KASEA16(+) hydrogel will be a useful scaffold for cell culture.

The complete control of murine pregnancy from embryo implantation to parturition.

The ovary is the main secretory source of progestin and estrogen and is indispensable to the maintenance of all events of pregnancy in mice. The purpose of this study was to control all processes of pregnancy in mice, from embryo implantation to parturition, without ovaries. The ovaries were removed before embryo implantation, and a single injection of medroxyprogesterone acetate (MPA) was given. Embryo implantation was induced by leukemia inhibitory factor, which can substitute 17ß-estradiol (E(2)). Continuous exposure to E(2) was necessary at mid-pregnancy, when placentation was completed. All mice sustained pregnancy without ovaries before parturition, which was initiated by the removal of E(2) and MPA. Murine pregnancy is a complicated process involving embryo implantation, placentation, and parturition. Complete control of pregnancy was achieved with the simple treatment of MPA and E(2) after induction of embryo implantation. Here, time-dependent events in the uterus during pregnancy could be realized without the ovaries, because the initiation of each event could be stringently controlled by hormonal treatments.

Hepatocyte apoptosis in dairy cattle during the transition period.

The objective of this study was to investigate hepatocyte apoptosis in dairy cows during the transition period. Four clinically healthy, pregnant dairy cattle were used. The cows had no clinical diseases throughout this study. Blood samples were collected and livers were biopsied from the cows at 3 different times: 3 weeks before expected partition (wk -3); during parturition (wk 0), and 3 weeks (wk +3) after parturition. The damage to deoxyribonucleic acid (DNA) caused by hepatocytes was evaluated by comet assay. The apoptotic features of hepatocytes were examined by immunohistochemistry and electron microscopic analyses. The hepatic triglyceride content markedly increased at wk 0 and wk +3 compared with the values at wk -3. The results of the comet assay showed increases in the mean tail moment values of hepatic cells after parturition in all cows, which suggested increased DNA damage. Histopathologically, the hepatocytes began to contain lipid droplets at wk 0 and were severely opacified at wk +3. Caspase-3-positive and single-stranded DNA-(ssDNA)-positive cells were first detected in the liver after parturition. Condensation of nuclear chromatin, a typical sign of apoptosis, was confirmed by transmission electron microscopy after parturition. These results suggest that apoptosis is induced in hepatocytes of dairy cows around parturition and may result from lipotoxicity in hepatocytes.

L'objectif de ce travail était d'étudier l'apoptose des hépatocytes chez les vaches laitières durant la période de transition. Quatre vaches laitières gestantes et cliniquement saines faisaient partie de l'étude. Les vaches n'ont présenté aucune maladie clinique tout au long de l'étude. Des échantillons sanguins ont été prélevés et des biopsies hépatiques obtenues à partir des animaux à trois moments différents : 3 semaines avant la date prévue de parturition (sem −3); durant la parturition (sem 0) et 3 semaines après la parturition (sem +3). Les dommages à l'ADN causés par les hépatocytes ont été évalués par l'essai Comet. Les caractéristiques apoptotiques des hépatocytes ont été examinées par analyses immunohistochimiques et par microscopie électronique. Le contenu hépatique en triglycéride augmenta de manière marquée aux sem 0 et +3 comparativement à la valeur observée à sem −3. Les résultats de l'essai Comet ont montré pour les hépatocytes de toutes les vaches après parturition des augmentations des valeurs du moment moyen de la queue, ce qui suggérait une augmentation des dommages à l'ADN. À l'examen histopathologique, les hépatocytes commencèrent à contenir des gouttelettes lipidiques à la sem 0 et étaient sévèrement opacifiés à la sem +3. Les cellules positives pour la caspase-3 et celles positives pour de l'ADN simple brin ont été les premières à être détectées dans le foie après la parturition. La condensation de la chromatine nucléaire, un signe typique d'apoptose, a été confirmée par microscopie électronique à transmission après la parturition. Ces résultats suggèrent que l'apoptose est induite dans les hépatocytes des vaches laitières aux alentours de la parturition et pourrait résulter d'une lipotoxicité dans les hépatocytes.(Traduit par Docteur Serge Messier).

Embryo implantation is blocked by intraperitoneal injection with anti-LIF antibody in mice.

Leukemia inhibitory factor (LIF) is essential for embryo implantation in mice and plays an important role in other mammals including humans. Intraperitoneal (i.p.) injections with anti-LIF antibody (7.5 µg/g body weight, 3 times) between D3 (D1 = day of vaginal plug detection) and D4 effectively blocked embryo implantation; complete inhibition was achieved in C57BL/6J mice, and implantation was dramatically reduced in ICR mice (reduced to 27%). Normal rabbit IgG used as the control did not disturb embryo implantation. Anti-LIF antibody was localized not only in the stroma, but also in the luminal epithelium and the glandular lumen after i.p. injections. Growth-arrested blastocysts were recovered from the uterus without any implantation sites in both strains. Blastocysts made contact with the LE on the antimesometrial side; however, uterine stromal cells did not undergo secondary decidual reaction, and the uterine lumen was open, even at D7. Several regions of decidualization in ICR mice treated with anti-LIF antibody were smaller than those of the control, and development of blastocysts was delayed. The expression of LIF-regulated genes, such as immune-responsive gene-1 and insulin-like growth factor binding protein-3, was significantly decreased in C57BL/6J mice treated with anti-LIF antibody compared with the control, but not in ICR mice. The present study demonstrated that simple ip injections of an antibody are sufficient to block one of the important factors involved in embryo implantation in mice, and this method should also be easily applicable to the investigation of other factors involved in implantation.

Expression of the centrosomal colon cancer autoantigen gene during spermatogenesis in the maturing rat testis.

We analyzed the gene and protein expression of serologically defined colon cancer antigen 8. Gene expression was upregulated in the maturing rat testis, and was localized to the spermatocytes. Protein was detected in the spermatids and at the sites of mRNA expression. Specific expression of colon cancer antigen 8 was observed in the maturing rat testis.

Comparative study of the properties of tendinocytes derived from three different sites in the equine superficial digital flexor tendon.

This aim of this study was to determine the characteristic differences in tendinocytes derived from three sites of the equine superficial digital flexor tendon (SDFT)-proximally the myotendinous junction (MTJ), mid-metacarpal (mM) and osteotendinous junction (OTJ)-in morphology, proliferation, and ability for synthesis of collagen and matrix metalloproteinases (MMPs). Little difference was observed in cell proliferation. Addition of tumor necrosis factor (TNF) alpha to the culture medium resulted in increased collagen synthesis by tendinocytes from all three sites. The amount of collagen synthesized by tendinocytes derived from the mM and OTJ was much larger than that synthesized by untreated tendinocytes. A collagen zymogram revealed that proMMP-13 synthesis was increased towards the distal site. However, TNFalpha treatment resulted in a significant decrease in the amount of proMMP-13 synthesized by tendinocytes from all three sites. On the other hand, a gelatin zymogram showed that the synthesis level of proMMP-9 tended to decrease towards the distal site, but there was little difference between synthesis levels of proMMP-9 before and after TNFalpha treatment. These results indicated that tendinocytes in the same tendon have different characteristics and that these characterisities would reflect the function of tendinocytes in vivo. Also, the isolated tendinocytes provided much information on the characteristics and properties of tendons for the ECM turnover system and on the responsiveness of tendinocytes to complex inflammatory responses in a tendinopathy condition.

Effect of collagen oligopeptide injection on rabbit tenositis.

Effects of the collagen oligopeptide (COP) were examined by its repeat injection into the inflammatory rabbit Achilles tendon (Tendo calcaneus communis), in which tenositis was induced by injection of bacterial collagenase. COP was evaluated 5 times over a period of 3 weeks to 1 month after injection of collagenase. At 1 month after treatment, the therapeutic effect of COP was evaluated by examining the structure of collagen fibrils, amount and components of glycosaminoglycans (GAGs) and matrix metalloproteinases (MMPs), and compared with the saline injection, control, and normal groups. The Achilles tendon of rabbit in the control group (no COP injection) and saline injection group showed a notable increase in the number of fine collagen fibrils, a change in GAG composition and increase in the amount of pro-MMP-2, indicating the weakening of the tendon. In contrast, the size distribution of collagen fibrils, GAG composition and the amount of pro-MMP-2 was similar to those in the normal group. These results suggest that COP injection promotes healing processes of the tendon injury.

Effect of heat on synthesis of gelatinases and pro-inflammatory cytokines in equine tendinocytes.

The aim of this study was to clarify whether matrix metalloproteinases (MMP-2 and -9: gelatinases) and pro-inflammatory cytokines [tumor necrosis factor (TNF) alpha and interleukin (IL)-1beta] are induced by heat in tendon tissue in vitro and to test the hypothesis that heat exposure causes tendinocytes to synthesize pro-inflammatory cytokines and that synthesis of these cytokines, in turn, leads to up-regulation of synthesis of gelatinases. Isolated tendinocytes from equine superficial digital flexor tendons were cultured and all experiments were performed on cells passaged 3 or 4 times. In the cells exposed to heat (37 to 45 degrees C, 0 to 60 min), the survival rate decreased sharply in a temperature- and time-dependent manner, especially at 42 and 45 degrees C. Cells exposed at 40 degrees C, however, showed little change in survival rate and morphology. Gelatin zymograms revealed that proMMP-2 and -9 were the only two MMPs remaining in the supernatant of the cultured tendinocytes, including that of untreated cells. Addition of TNFalpha and IL-1beta to the culture medium of tendinocytes accelerated proMMP-9 synthesis considerably. Heating the tendinocytes (40 degrees C) led to a three-fold increase in proMMP-9 synthesis in a short time. Only TNFalpha was detected in tendinocytes after heat exposure for 30 and 60 min. In contrast, IL-1beta was under the detectable level in ELISA. Cooling of heat-exposed cells from 40 degrees C to 37 degrees C considerably down-regulated cellular proMMP-9 synthesis. Furthermore, proMMP-9 level was greatly reduced in cells treated at lower temperatures, 20 degrees C and 5 degrees C. These findings support our hypothesis that hyperthermia in the horse tendon induces tendinocytes to synthesize pro-inflammatory cytokines and that the synthesis of these cytokines results in the up-regulation of gelatinases.