Triptolide attenuates pulmonary fibrosis by inhibiting fibrotic extracellular matrix remodeling mediated by MMPs/LOX/integrin

BACKGROUND

Fibrotic extracellular matrix (ECM) remodeling characterized different types of pulmonary fibrosis, and its regulation could be a potential shared treatment strategy for pulmonary fibrosis.

PURPOSE

We aimed to investigate the effect of triptolide on pulmonary fibrosis through the inhibition of several important aspects of fibrotic ECM remodeling.

METHODS

Bleomycin-induced pulmonary fibrosis mice and TGF-β1-induced primary lung fibroblasts were used. The effect of triptolide on pulmonary fibrosis was detected using histopathology, immunostaining, RT-qPCR, western blotting, ELISA, and protein activity assay.

RESULTS

Triptolide significantly alleviated bleomycin-induced pulmonary fibrosis in mice. It inhibited the expression of fibrotic genes α-SMA, collagen I, fibronectin, and vimentin and blocked the TGF-β-SMAD signaling pathway both in vivo and in vitro. In addition, triptolide regulated the expression and activity of MMPs during fibrosis. Interestingly, it suppressed the expression of lysyl oxidase, which was responsible for matrix cross-linking and elevated ECM stiffness. Furthermore, triptolide blocked the biomechanical stress transduction pathway integrin-β1-FAK-YAP signaling and attenuated the pro-fibrotic feedback of fibrotic ECM on fibroblasts via integrin inhibition.

CONCLUSION

These findings show that triptolide prevents the key linkages of fibrotic ECM remodeling, including deposition, degradation, cross-linking, and pro-fibrotic feedback and, therefore, has potential therapeutic value for pulmonary fibrosis.

Danhong injection enhances the therapeutic effect of mannitol on hemispheric ischemic stroke by ameliorating blood-brain barrier disruption

Mannitol, a representative of hyperosmolar therapy, is indispensable for the treatment of malignant cerebral infarction, but its therapeutic effect is limited by its exacerbation of blood-brain barrier (BBB) disruption. This study was to explore whether Danhong injection (DHI), a standardized product extracted from Salvia miltiorrhiza Bunge and Carthamus tinctorius L., inhibits the destructive effect of mannitol on BBB and thus enhancing the treatment of hemispheric ischemic stroke. SD rats were subjected to pMCAO followed by intravenous bolus injections of mannitol with/without DHI intervention. Neurological deficit score, brain edema, infarct volume at 24 h after MCAO and histopathology, microvascular ultrastructure, immunohistochemistry and immunofluorescence staining of endothelial cell junctions, energy metabolism in the ischemic penumbra were assessed. Intravenous mannitol after MCAO resulted in a decrease in 24 h mortality and cerebral edema, whereas no significant benefit on neurological deficits, infarct volume and microvascular ultrastructure. Moreover, mannitol led to the loss of endothelial integrity, manifested by the decreased expression of occludin, junctional adhesion molecule-1 (JAM-1) and zonula occluden-1 (ZO-1) and the discontinuity of occludin staining around the periphery of endothelial cells. Meanwhile, after mannitol treatment, energy-dependent vimentin and F-actin, ATP content, and ATP5D expression were down-regulated, while MMP2 and MMP9 expression increased in the ischemic penumbra. All the insults after mannitol treatment were attenuated by addition of intravenous DHI. The results suggest DHI as a potential remedy to attenuate mannitol-related BBB disruption, and the potential of DHI to upregulate energy metabolism and inhibit the activity of MMPs is likely attributable to its effects observed.

Matrix Metalloproteinases and Glaucoma Treatment

Matrix metalloproteinases (MMPs) are a family of proteolytic enzymes that degrade extracellular matrix (ECM) components such as collagen and have important roles in multiple biological processes, including development and tissue remodeling, both in health and disease. The activity of MMPs is influenced by the expression of MMPs and tissue inhibitors of metalloproteinase (TIMPs). In the eye, MMP-mediated ECM turnover in the juxtacanalicular region of the trabecular meshwork (TM) reduces outflow resistance in the conventional outflow pathway and helps maintain intraocular pressure (IOP) homeostasis. An imbalance in the MMP/TIMP ratio may be involved in the elevated IOP often associated with glaucoma. The prostaglandin analog/prostamide (PGA) class of topical ocular hypotensive medications used in glaucoma treatment reduces IOP by increasing outflow through both conventional and unconventional (uveoscleral) outflow pathways. Evidence from in vivo and in vitro studies using animal models and anterior segment explant and cell cultures indicates that the mechanism of IOP lowering by PGAs involves increased MMP expression in the TM and ciliary body, leading to tissue remodeling that enhances conventional and unconventional outflow. PGA effects on MMP expression are dependent on the identity and concentration of the PGA. An intracameral sustained-release PGA implant (Bimatoprost SR) in development for glaucoma treatment can reduce IOP for many months after expected intraocular drug bioavailability. We hypothesize that the higher concentrations of bimatoprost achieved in ocular outflow tissues with the implant produce greater MMP upregulation and more extensive, sustained MMP-mediated target tissue remodeling, providing an extended duration of effect.

Methotrexate an Old Drug with New Tricks

Methotrexate (MTX) is the first line drug for the treatment of a number of rheumatic and non-rheumatic disorders. It is currently used as an anchor disease, modifying anti-rheumatic drug in the treatment of rheumatoid arthritis (RA). Despite the development of numerous new targeted therapies, MTX remains the backbone of RA therapy due to its potent efficacy and tolerability. There has been also a growing interest in the use of MTX in the treatment of chronic viral mediated arthritis. Many viruses—including old world alphaviruses, Parvovirus B19, hepatitis B/C virus, and human immunodeficiency virus—have been associated with arthritogenic diseases and reminiscent of RA. MTX may provide benefits although with the potential risk of attenuating patients’ immune surveillance capacities. In this review, we describe the emerging mechanisms of action of MTX as an anti-inflammatory drug and complementing its well-established immunomodulatory activity. The mechanisms involve adenosine signaling modulation, alteration of cytokine networks, generation of reactive oxygen species and HMGB1 alarmin suppression. We also provide a comprehensive understanding of the mechanisms of MTX toxic effects. Lastly, we discussed the efficacy, as well as the safety, of MTX used in the management of viral-related rheumatic syndromes.

Phloretin suppresses metastasis by targeting protease and inhibits cancer stemness and angiogenesis in human cervical cancer cells

BACKGROUND

Phloretin, a dihydrochalcone flavonoid, possesses anti-inflammatory activity and inhibits the growth of various cancers. However, the flavonoid's effect on cervical cancer metastasis and angiogenesis remains unknown.

PURPOSE

In this study, we provide molecular evidence associated with the antimetastatic and antiangiogenic effects of phloretin.

METHODS

In this study, the anti-invasive effect of phloretin (0-60 μM) in cervical cancer cells was evaluated using the Matrigel invasion assay, gelatin zymography, cell-matrix adhesion assay, wound healing assay, and Western blotting. Antiangiogenic potential of phloretin (0-100 μM) was assessed by the Matrigel tube formation assay. The in vivo antitumor effect of phloretin (10 or 20 mg/kg) was fed by oral gavage and determined using subcutaneous inoculation and tail vein injection in immunodeficient nude mice.

RESULTS

Phloretin (60 μM) showed marked suppression of invasion and migration through downregulation of matrix metalloproteinase (MMP)-2, MMP-3, and cathepsin S in human SiHa cervical cancer cells. Phloretin (60 μM) reversed the epithelial-mesenchymal transition induced by transforming growth factor-β1 and downregulated mesenchymal markers, such as fibronectin, vimentin, and RhoA. Phloretin (100 μM) treatment significantly inhibited the aldehyde dehydrogenase 1 activity of SiHa cells, reduced the self-renewal properties and stemness signatures of CD44 and Sox-2 in sphere-forming cervical cancer-derived tumor-initiating cells, and inhibited the invasion, MMP-2 activity, and tube formation capacity of human umbilical vein endothelial cells. The ability of phloretin (20 mg/kg) to suppress lung metastasis and tumor growth in SiHa cells was evidenced by tail vein injection and subcutaneous inoculation in a tumor xenograft model.

CONCLUSION

In summary, the findings indicate that phloretin inhibits the metastatic and angiogenic abilities and cancer stemness of SiHa cells, thereby suggesting that this flavonoid is a promising therapeutic agent for the treatment of human cervical cancer cells.

Chlorin e6-mediated photodynamic therapy promotes collagen production and suppresses MMPs expression via modulating AP-1 signaling in P. acnes-stimulated HaCaT cells

BACKGROUND

Photodynamic therapy (PDT) is a clinically approved therapeutic for cancers and non-neoplastic diseases, based on the use of a photosensitizer activated by light. The feasibility of PDT depends on several factors, such as PDT dose, photosensitizer efficacy, type of light source, and target tissue irradiated.

METHODS

In this study, the second generation photosensitizer chlorin e6 (Ce6) and halogen light were used to investigate their PDT effect on the collagen production and MMPs expression of heat killed P. acnes-stimulated HaCaT cells. The mRNA levels of COL1A1, c-Jun, and c-Fos were detected by RT-PCR. The protein levels of MMPs, ERK and JNK were detected by western blot. The transactivation of AP-1 was detected by luciferase assay.

RESULTS

Ce6-based PDT markedly upregulated the mRNA level of COL1A1 and type I procollagen level; and at the same time downregulated the expression of MMPs in P. acnes-infected HaCaT cells. Moreover, Ce6-mediated PDT, in a dose dependent manner, inhibited P. acnes-induced phosphorylation of JNK and ERK, as wells as the phosphorylation of their downstream targets c-Jun and c-Fos. P. acnes-induced mRNA expression of c-Jun and c-Fos were also suppressed by Ce6-mediated PDT. The transactivation of AP-1 induced by P. acnes infection was also downregulated.

CONCLUSION

These results indicated that Ce6-mediated PDT with halogen light enhanced collagen production, but inhibited the expression of MMPs in P. acnes-infected HaCaT cells, by regulating AP-1 signals. This investigation provided the first molecular basis for the increase in collagen production by Ce6-mediated PDT, suggesting its potential use for scar amelioration and skin rejuvenation in acne treatment.

Co-distribution of cysteine cathepsins and matrix metalloproteases in human dentin

It has been hypothesized that cysteine cathepsins (CTs) along with matrix metalloproteases (MMPs) may work in conjunction in the proteolysis of mature dentin matrix. The aim of this study was to verify simultaneously the distribution and presence of cathepsins B (CT-B) and K (CT-K) in partially demineralized dentin; and further to evaluate the activity of CTs and MMPs in the same tissue. The distribution of CT-B and CT-K in sound human dentin was assessed by immunohistochemistry. A double-immunolabeling technique was used to identify, at once, the occurrence of those enzymes in dentin. Activities of CTs and MMPs in dentin extracts were evaluated spectrofluorometrically. In addition, in situ gelatinolytic activity of dentin was assayed by zymography. The results revealed the distribution of CT-B and CT-K along the dentin organic matrix and also indicated co-occurrence of MMPs and CTs in that tissue. The enzyme kinetics studies showed proteolytic activity in dentin extracts for both classes of proteases. Furthermore, it was observed that, at least for sound human dentin matrices, the activity of MMPs seems to be predominant over the CTs one.

[The influence of antihypertensive treatment on arterial stiffness, shear stress and activity of chosen matrix metalloproteinases]

The aim of the study was to compare therapeutic effects of chosen antihypertensive drugs on arterial stiffness, shear stress in carotid arteries and metalloproteinases activity, moreover analysis of relationship of these variables in the course of treatment.

METHODS

95 patients with essential arterial hypertension stage 1 or 2 were randomized to 6 months monotherapy with: quinapril, amlodipine, hydrochlorothiazide, losartan or bisoprolol. Each therapeutic group consisted of 19 patients (N=19). Before and then after 1, 3 and 6 months of treatment carotid-femoral pulse wave velocity (PWV) by using a Complior device, ultrasound of carotid arteries were performed. Blood samples for the measurement of whole blood viscosity were taken during each visit. Shear stress (SS) was calculated using measured variables: blood viscosity and velocity of blood flow. Serum concentration of metalloproteinase 3 (MMP-3) and plasma concentration of tissue inhibitor of metalloproteinase I (TIMP-1) were measured at the initial visit and after 6 months of treatment.

RESULTS

ANOVA for repeated measurements revealed for all groups significant decrease of PWV (ΔPWV) and MMP-3 (ΔMMP-3) concentration and increase of shear stress in carotid artery and TIMP-1 (ΔTIMP-1) concentration (p<0.05). No between groups differences appeared in above effects (p>0.05). The multiple regression analysis for the change of PWV (ΔPWV) in the study group considering all investigated variables at R2 = 0,27 revealed its significant relation to PWV at first visit, ΔTIMP-1, ΔMMP-3 and Δ shear stress counted for the maximum flow velocity in common carotid artery. Conclusion: Irrespectively of chosen drug we observed similar effect for PWV drop. Reduction of arterial stiffness as a result of antihypertensive therapy is strongly connected with shear stress increase that is secondary to blood flow velocity growth and changes in connective tissue metabolism.

Effects of maternal dietary olive oil on pathways involved in diabetic embryopathy

Maternal diabetes induces a pro-oxidant/pro-inflammatory intrauterine environment related to the induction of congenital anomalies. Peroxisome proliferator activated receptors (PPARs) are transcription factors that regulate antioxidant and anti-inflammatory pathways. We investigated whether maternal diets supplemented with olive oil, enriched in oleic acid, a PPAR agonist, can regulate the expression of PPAR system genes, levels of lipoperoxidation and activity of matrix metalloproteinases (MMPs) and their endogenous inhibitors (TIMPs) in embryos and decidua from diabetic rats. The embryos and decidua from diabetic rats showed reduced expression of PPARs and increased concentration of lipoperoxidation, MMPs and TIMPs, whereas the maternal treatments enriched in olive oil increased PPARδ in embryos and PPARγ and PPARγ-coactivator-1α expression in decidua, and increased TIMPs concentrations and decreased lipoperoxidation and MMPs activity in both tissues. Thus, maternal diets enriched in olive oil can regulate embryonic and decidual PPAR system genes expression and reduce the pro-oxidant/pro-inflammatory environment during rat early organogenesis.

CXCR4-targeted and MMP-responsive iron oxide nanoparticles for enhanced magnetic resonance imaging

MRI offers high spatial resolution with excellent tissue penetration but it has limited sensitivity and the commonly administered contrast agents lack specificity. In this study, two sets of iron oxide nanoparticles (IONPs) were synthesized that were designed to selectively undergo copper-free click conjugation upon sensing of matrix metalloproteinase (MMP) enzymes, thereby leading to a self-assembled superparamagnetic nanocluster network with T2 signal enhancement properties. For this purpose, IONPs with bioorthogonal azide and alkyne surfaces masked by polyethylene glycol (PEG) layers tethered to CXCR4-targeted peptide ligands were synthesized and characterized. The IONPs were tested in vitro and T2 signal enhancements of around 160 % were measured when the IONPs were incubated with cells expressing MMP2/9 and CXCR4. Simultaneous systemic administration of the bioorthogonal IONPs in tumor-bearing mice demonstrated the signal-enhancing ability of these 'smart' self-assembling nanomaterials.

Celecoxib exerts protective effects on extracellular matrix metabolism of mandibular condylar chondrocytes under excessive mechanical stress

OBJECTIVE

Excessive mechanical stress is considered a major cause of temporomandibular joint osteoarthritis (TMJ-OA). High magnitude cyclic tensile strain (CTS) up-regulates pro-inflammatory cytokines and matrix metalloproteinases (MMPs) in chondrocytes, while selective cyclooxygenase (COX)-2 inhibition has been shown to be beneficial to cytokine-induced cartilage damage. However, the effect of selective COX-2 inhibitors on mechanically stimulated chondrocytes remains unclear. This study evaluated the effect of celecoxib, a selective COX-2 inhibitor, on extracellular matrix (ECM) metabolism of mandibular condylar chondrocytes under CTS.

METHODS

Porcine mandibular chondrocytes were subjected to CTS of 0.5 Hz, 10% elongation with celecoxib for 24 h. The gene expressions of COX-2, MMPs, aggrecanase (ADAMTS), type II collagen and aggrecan were examined by real-time PCR. Also, prostaglandin E2 (PGE2) concentrations were determined using enzyme immunoassay kit. The levels of MMP and transcription factor NF-κB were measured by western blot while MMP activity was determined by casein zymography.

RESULTS

The presence of celecoxib normalized the release of PGE2 and diminished the CTS-induced COX-2, MMP-1, MMP-3, MMP-9 and ADAMTS-5 gene expressions while recovered the downregulated type II collagen and aggrecan gene expressions. Concurrently, celecoxib showed inhibition of NF-κB and suppression of MMP production and activity.

CONCLUSIONS

Celecoxib exerts protective effects on mandibular condylar chondrocytes under CTS stimulation by diminishing degradation and restoring synthesis of ECM.

Rescue of proinflammatory cytokine-inhibited chondrogenesis by the antiarthritic effect of melatonin in synovium mesenchymal stem cells via suppression of reactive oxygen species and matrix metalloproteinases

Cartilage repair by mesenchymal stem cells (MSCs) often occurs in diseased joints in which the inflamed microenvironment impairs chondrogenic maturation and causes neocartilage degradation. In this environment, melatonin exerts an antioxidant effect by scavenging free radicals. This study aimed to investigate the anti-inflammatory and chondroprotective effects of melatonin on human MSCs in a proinflammatory cytokine-induced arthritic environment. MSCs were induced toward chondrogenesis in the presence of interleukin-1β (IL-1β) or tumor necrosis factor α (TNF-α) with or without melatonin. Levels of intracellular reactive oxygen species (ROS), hydrogen peroxide, antioxidant enzymes, and cell viability were then assessed. Deposition of glycosaminoglycans and collagens was also determined by histological analysis. Gene expression of chondrogenic markers and matrix metalloproteinases (MMPs) was assessed by real-time polymerase chain reaction. In addition, the involvement of the melatonin receptor and superoxide dismutase (SOD) in chondrogenesis was investigated using pharmacologic inhibitors. The results showed that melatonin significantly reduced ROS accumulation and increased SOD expression. Both IL-1β and TNF-α had an inhibitory effect on the chondrogenesis of MSCs, but melatonin successfully restored the low expression of cartilage matrix and chondrogenic genes. Melatonin prevented cartilage degradation by downregulating MMPs. The addition of luzindole and SOD inhibitors abrogated the protective effect of melatonin associated with increased levels of ROS and MMPs. These results demonstrated that proinflammatory cytokines impair the chondrogenesis of MSCs, which was rescued by melatonin treatment. This chondroprotective effect was potentially correlated to decreased ROS, preserved SOD, and suppressed levels of MMPs. Thus, melatonin provides a new strategy for promoting cell-based cartilage regeneration in diseased or injured joints.

Effect of alpha-resorcylic acid-L-phenylalanine amide on collagen synthesis and matrix metalloproteinase expression in fibroblasts

Regulation of collagen synthesis and matrix metalloproteinases (MMPs) expression levels has been an important issue in medicinal, pharmaceutical and cosmetic industries. Herein, α-Resorcylic acid-phenylalanine amide (α-RA-F) was prepared and its biological activities were observed. We found that α-RA-F boosted collagen synthesis and reduced MMPs expression levels in human fibroblasts without cytotoxicity.

Nebivolol attenuates prooxidant and profibrotic mechanisms involving TGF-β and MMPs, and decreases vascular remodeling in renovascular hypertension

Nebivolol and metoprolol are β1-adrenergic receptor blockers with different properties. We hypothesized that nebivolol, but not metoprolol, could attenuate prooxidant and profibrotic mechanisms of hypertension and therefore protect against the vascular remodeling associated with hypertension. Hypertension was induced in male Wistar rats by clipping the left renal artery. Six weeks after surgery, hypertensive and sham rats were treated with nebivolol (10 mg kg(-1) day(-1)) or metoprolol (20 mg kg(-1) day(-1)) for 4 weeks. Systolic blood pressure was monitored weekly. Morphologic changes in the aortic wall were studied in hematoxylin/eosin and picrosirius red sections. Aortic NAD(P)H activity and superoxide production were evaluated by luminescence and dihydroethidium, respectively, and TBARS levels were measured in plasma. Aortic nitrotyrosine staining was evaluated to assess peroxynitrite formation. TGF-β levels and p-ERK 1/2 expression were determined by immunofluorescence and Western blotting, respectively. Matrix metalloproteinase (MMP) activity and expression were determined by in situ zymography, gel zymography, Western blotting, and immunofluorescence, and TIMP-1 was assessed by immunohistochemistry. Both β1-receptor antagonists exerted very similar antihypertensive effects. However, while metoprolol had no significant effects, nebivolol significantly attenuated vascular remodeling and collagen deposition associated with hypertension. Moreover, nebivolol, but not metoprolol, attenuated hypertension-induced increases in aortic NAD(P)H oxidase activity, superoxide production, TBARS concentrations, nitrotyrosine levels, TGF-β upregulation, and MMP-2 and -9 expression/activity. No effects on p-ERK 1/2 and TIMP-1 expression were found. These results show for the first time that nebivolol, but not metoprolol, attenuates prooxidant and profibrotic mechanisms involving TGF-β and MMP-2 and MMP-9, which promote vascular remodeling in hypertension.

Inactivation of matrix-bound matrix metalloproteinases by cross-linking agents in acid-etched dentin

OBJECTIVES

Published transmission electron microscopy analysis of in vitro resin-dentin bonds shows that, after 44 months, almost 70% of collagen fibrils from the hybrid layer disappear. Matrix metalloproteinases (MMPs) play an important role in that process and are thought to be the main factor responsible for the solubilization of dentin collagen. Therefore, this study aimed to evaluate the inactivation of matrix-bound MMPs by two different cross-linking agents, carbodiimide (EDC) or proanthocyanidin (PA), or the MMP-inhibitor, chlorhexidine (CHX), on acid-etched dentin using a simplified MMP assay method.

MATERIALS AND METHODS

Dentin beams (2×1×6 mm) were obtained from mid-coronal dentin of sound third molars and randomly divided into six groups (G) according to the dentin treatment: G1: Deionized water (control); G2: 0.1 M EDC; G3: 0.5 M EDC; G4: 0.5 M EDC + 35% hydroxyethyl methacrylate (HEMA); G5: 5% PA; and G6: 2% CHX. The beams were etched for 15 seconds with 37% phosphoric acid, rinsed, and then immersed for 60 seconds in one of the treatment solutions. The data were expressed both in absorbance values at 412 nm and in MMP-9 activity equivalents. The total MMP activity of dentin was analyzed for one hour by colorimetric assay (Sensolyte). Data were submitted to Wilcoxon nonparametric test and Mann-Whitney tests (p>0.05).

RESULTS

All experimental cross-linking solutions significantly reduced MMP activity from 79.8% to 95.2% when compared to the control group. No difference was observed among 0.1 M EDC (84.8%), 5% PA (87.6%), and 2% CHX (79.8%). Addition of 35% HEMA to 0.5 M EDC produced inactivation (95.2%) that was similar to that of 0.5 M EDC alone (92.7%).

CONCLUSION

Dentin treatment with cross-linking agents is effective to significantly reduce MMP activity. Mixing 0.5 M EDC and 35% HEMA did not influence EDC inhibitor potential.

Hericium erinaceus (Lion's Mane) mushroom extracts inhibit metastasis of cancer cells to the lung in CT-26 colon cancer-tansplanted mice

This study investigated the antimetastatic activity of four Hericium erinaceus edible mushroom extracts using CT-26 murine colon carcinoma cells as an indicator of inhibition of cell migration to the lung. Hot water (HWE) and microwaved 50% ethanol (MWE) extracts of H. erinaceus strongly elicited cancer cell death through apoptosis and inhibited metastasis of cancer cells to the lungs by 66% and 69%, respectively. HWE and MWE reduced the expression of matrix metalloproteinases MMP-2 and MMP-9 in cells and their activities in culture media. Urokinase-type plasminogen activator (u-PA), another extracellular matrix (ECM)-degrading proteinase, also showed decreased protein expression. In CT-26 cells, HWE and MWE down-regulated extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (MAPK) phosphorylations. The reduced phosphorylations seem to cause reduction of activity of the MMPs, thereby blocking migration and invasion of cells. Dietary administration of HWE and MWE reduced the formation of tumor nodules in the lung by about 50% and 55%, respectively, and prevented increases in lung weight caused by cancer cell metastasis. These results demonstrate the effectiveness of HWE and MWE as beneficial antimetastatic agents, targeting their upstream signaling molecules for mediating the expression of the ECM-degrading proteinases. Acidic and alkaline extracts were not bioactive. Bioactivity seems to be related to composition. H. erinaceus edible mushrooms have the potential to serve as a health-promoting functional food.

Cigarette smoke extract induces select matrix metalloproteinases and integrin expression in periodontal ligament fibroblasts

BACKGROUND

The periodontal ligament (PDL) is the connective tissue that anchors the cementum of the teeth to the alveolar bone. PDL fibroblasts are responsible for the production of collagen and remodeling of the PDL. Periodontal disease is increased among smokers in both incidence and severity. This study examines the direct effect of smoking on PDL fibroblasts and their production of various matrix components and remodeling enzymes.

METHODS

PDL cells were plated for 1 day and then treated with various concentrations of cigarette smoke extract (CSE). Survival of PDL cells was quantified after exposure to CSE, and their ability to contract three-dimensional collagen gels was examined. Changes in transcript expression after CSE treatment was compared using reverse transcription-polymerase chain reaction analysis for matrix metalloproteinases (MMPs), collagens, and integrins.

RESULTS

Treatment with CSE-induced cell death at concentrations of ≥5%. PDL-cell-induced collagen gel contraction was reduced at concentrations of 1.5% CSE. Treatment with CSE selectively increased the expression of collagen Vα3 and decreased collagen XIα1. CSE increased the expression of MMP1 and MMP3 and, to a lesser extent, MMP2 and MMP8. CSE also increased the expression of integrins α1, α2, and α10 (collagen receptors) and α9 (a tenascin receptor).

CONCLUSIONS

This study shows that cigarette smoking has local effects on the cells of the PDL. CSE reduced survival of PDL cells and their ability to contract collagen matrices. CSE also altered the expression of molecules known to provide the structural integrity of the ligament by altering collagen synthesis and remodeling as well as cell adhesion.

Anti-arthritic effects of magnolol in human interleukin 1β-stimulated fibroblast-like synoviocytes and in a rat arthritis model

Fibroblast-like synoviocytes (FLS) play an important role in the pathologic processes of destructive arthritis by producing a number of catabolic cytokines and metalloproteinases (MMPs). The expression of these mediators is controlled at the transcriptional level. The purposes of this study were to evaluate the anti-arthritic effects of magnolol (5,5'-Diallyl-biphenyl-2,2'-diol), the major bioactive component of the bark of Magnolia officinalis, by examining its inhibitory effects on inflammatory mediator secretion and the NF-κB and AP-1 activation pathways and to investigate its therapeutic effects on the development of arthritis in a rat model. The in vitro anti-arthritic activity of magnolol was tested on interleukin (IL)-1β-stimulated FLS by measuring levels of IL-6, cyclooxygenase-2, prostaglandin E(2), and matrix metalloproteinases (MMPs) by ELISA and RT-PCR. Further studies on how magnolol inhibits IL-1β-stimulated cytokine expression were performed using Western blots, reporter gene assay, electrophoretic mobility shift assay, and confocal microscope analysis. The in vivo anti-arthritic effects of magnolol were evaluated in a Mycobacterium butyricum-induced arthritis model in rats. Magnolol markedly inhibited IL-1β (10 ng/mL)-induced cytokine expression in a concentration-dependent manner (2.5-25 µg/mL). In clarifying the mechanisms involved, magnolol was found to inhibit the IL-1β-induced activation of the IKK/IκB/NF-κB and MAPKs pathways by suppressing the nuclear translocation and DNA binding activity of both transcription factors. In the animal model, magnolol (100 mg/kg) significantly inhibited paw swelling and reduced serum cytokine levels. Our results demonstrate that magnolol inhibits the development of arthritis, suggesting that it might provide a new therapeutic approach to inflammatory arthritis diseases.

Crocetin inhibits invasiveness of MDA-MB-231 breast cancer cells via downregulation of matrix metalloproteinases

Crocetin is a carotenoid dicarboxylic acid which, in nature, is esterified with glucose or gentiobiose units forming the crocins, abundant components of saffron (a spice with many reputed medicinal uses). We have previously reported that saffron, crocins and crocetin inhibit breast cancer cell proliferation. In order to further study the effect of crocetin on breast cancer cells, we used the highly invasive MDA-MB-231 cells and measured the viability with the WST-1 assay and the invasiveness through a reconstituted basement membrane. After 24 h incubation, crocetin significantly inhibited not only proliferation but also invasion at 1 and 10 µM. Cancer invasiveness and metastasis are associated with the expression of matrix metalloproteinases (MMPs). In order to study the molecular changes of MMP expression that might accompany the observed crocetin effects, gene expression of MMPs was studied by RT-PCR, whereas protein expression and gelatinolytic activity were determined with Western blotting and zymography, respectively. The gene and protein expression of pro-MT1-MMP and pro-MT2-MMP were greatly attenuated by both crocetin and all- TRANS-retinoic acid (ATRA, used as control). Incubation with 10 µM crocetin for 24 h in serum-free conditions reduced pro-MMP-9 activity and pro-MMP-2/MMP-2 protein levels. When cultured in media with sera 2 and 5 %, crocetin at 10 μΜ also reduced gelatinase activity. The above findings show that crocetin, the main metabolite of crocins, inhibits MDA-MB-231 cell invasiveness via downregulation of MMP expression.

In vivo and In vitro effect of a nutrient mixture on human hepatocarcinoma cell line SK-HEP-1

Long-term survival of patients with hepatocellular carcinoma (HCC), a common cancer worldwide, remains poor, due to metastasis and recurrence.

AIM

To investigate the effect of a novel nutrient mixture (NM) containing ascorbic acid, lysine, proline, and green tea extract on human HCC cell line Sk-Hep-1 In vivo and In vitro.

METHODS

After one week of isolation, 5-6 week old male athymic nude mice were inoculated with 3 x 10(6) SK-Hep-1 cells subcutaneously and randomly divided into two groups; group A was fed a regular diet and group B a regular diet supplemented with 0.5% NM. Four weeks later, the mice were sacrificed and their tumors were excised, weighed and processed for histology. We also tested the effect of NM In vitro on SK-Hep-1 cells, measuring cell proliferation by MTT assay, invasion through Matrigel, apoptosis by green caspase detection kit, MMP secretion by zymography, and morphology by H&E staining.

RESULTS

NM inhibited tumor weight and burden of SK-Hep-1 xenografts by 42% and 33% respectively. In vitro , NM exhibited 33% toxicity over the control at 500 and 1,000 microg/ml concentration. Zymography demonstrated MMP-2 and MMP-9 secretion which was inhibited by NM in a dose dependent fashion, with virtual total inhibition at 1000 microg/ml. Invasion through Matrigel was inhibited at 100, 500 and 1,000 microg/ml by 53%, 83% and 100% respectively. NM induced slight apoptosis at 100 microg/ml, and profound apoptosis at 500 microg/ml and 1000 microg/ml concentration.

CONCLUSIONS

These results suggest that NM has therapeutic potential in treatment of HCC.

Effects of high glucose and thiamine on the balance between matrix metalloproteinases and their tissue inhibitors in vascular cells

Pericyte survival in diabetic retinopathy depends also on interactions with extracellular matrix (ECM) proteins, which are degraded by matrix metalloproteinases (MMP). Elevated glucose influences ECM turnover, through expression of MMP and their tissue inhibitors, TIMP. We reported on reduced pericyte adhesion to high glucose-conditioned ECM and correction by thiamine. We aimed at verifying the effects of thiamine and benfotiamine on MMP-2, MMP-9 and TIMP expression and activity in human vascular cells with high glucose. In HRP, MMP-2 activity, though not expression, increased with high glucose and decreased with thiamine and benfotiamine; TIMP-1 expression increased with high glucose plus thiamine and benfotiamine; MMP-9 was not expressed. In EC, MMP-9 and MMP-2 expression and activity increased with high glucose, but thiamine and benfotiamine had no effects; TIMP-1 expression was unchanged. Neither glucose nor thiamine modified TIMP-2 and TIMP-3 expression. TIMP-1 concentrations did not change in either HRP or EC. High glucose imbalances MMP/TIMP regulation, leading to increased ECM turnover. Thiamine and benfotiamine correct the increase in MMP-2 activity due to high glucose in HRP, while increasing TIMP-1.

Interleukin-1alpha treatment of meniscal explants stimulates the production and release of aggrecanase-generated, GAG-substituted aggrecan products and also the release of pre-formed, aggrecanase-generated G1 and m-calpain-generated G1-G2

Pro-inflammatory cytokines induce meniscal matrix degradation and inhibition of endogenous repair mechanisms, but the pathogenic mechanisms behind this are mostly unknown. Therefore, we investigated details of interleukin-1 (IL-1alpha)-induced aggrecan turnover in mature meniscal tissue explants. Fibro-cartilagenous disks (3 mm diameter x 1 mm thickness) were isolated from the central, weight-bearing region of menisci from 2-year-old cattle. After 3 or 6 days of IL-1alpha-treatment, GAG loss (DMMB assay), biosynthetic activity ([(35)SO(4)]-sulfate and [(3)H]-proline incorporation), gene expression (quantitative RT-PCR) and the abundance (zymography, Western blot) of matrix-degrading enzymes and specific aggrecan products were determined. Meniscal fibrocartilage had a 4-fold lower GAG content (per wet weight) than adjacent articular cartilage, and expressed MMPs-1, -2, -3 and ADAMTS4 constitutively, whereas ADAMTS5 m-RNA was essentially undetectable. Significant IL-1 effects were a decrease in biosynthetic activity, an increase in GAG release and in the expression/abundance of MMP-2, MMP-3 and ADAMTS4. Fresh tissue contained aggrecan core protein products similar to those previously described for bovine articular cartilage of this age. IL-1 induced the release of aggrecanase-generated CS-substituted products including both high (>250 kDa) and low molecular weight (about 75 kDa) species. TIMP-3 (but not TIMP-1 and -2 or a broad spectrum MMP inhibitor) inhibited IL-1-dependent GAG loss. In addition, IL-1 induced the release of preformed pools of three known G1-bearing products. We conclude that aggrecanases are responsible for IL-1-stimulated GAG release from meniscal explants, and that IL-1 also stimulates release of G1-bearing products, by a process possibly involving hyaluronan fragmentation.

Human rheumatoid arthritis tissue production of IL-17A drives matrix and cartilage degradation: synergy with tumour necrosis factor-alpha, Oncostatin M and response to biologic therapies

INTRODUCTION

The aim of this study was to examine IL-17A in patients, following anti-TNF-alpha therapy and the effect of IL-17A on matrix turnover and cartilage degradation.

METHODS

IL-17A expression was examined by ELISA and immunohistology in the rheumatoid arthritis (RA) joints. RA whole synovial tissue explant (RA ST), primary synovial fibroblasts (RASFC), human cartilage and chondrocyte cultures were stimulated with IL-17A +/- TNF-alpha and Oncostatin M (OSM). Matrix metalloproteinase (MMP) and tissue inhibitor (TIMP-1) were assessed by ELISA and zymography. Cartilage proteoglycan release was assessed histologically by Safranin-O staining. Clinical parameters, IL-17A, MMP/TIMP were assessed in patients pre/post biologic therapy.

RESULTS

IL-17A levels were higher in RA vs osteoarthritis (OA)/normal joints (P < 0.05). IL-17A up-regulated MMP-1, -2, -9, and -13 in RA ST, RASFC, cartilage and chondrocyte cultures (P < 0.05). In combination with TNF-alpha and OSM, IL-17A shifted the MMP:TIMP-1 ratio in favor of matrix degradation (all P < 0.05). Cartilage proteoglycan depletion in response to IL-17A was mild; however, in combination with TNF-alpha or OSM showed almost complete proteoglycan depletion. Serum IL-17A was detected in 28% of patients commencing biologic therapy. IL-17A negative patients demonstrated reductions post therapy in serum MMP1/TIMP4, MMP3/TIMP1 and MMP3/TIMP4 ratios and an increase in CS846 (all P < 0.05). No significant changes were observed in IL-17A positive patients.

CONCLUSIONS

IL-17A is produced locally in the inflamed RA joint. IL-17A promotes matrix turnover and cartilage destruction, especially in the presence of other cytokines, mimicking the joint environment. IL-17A levels are modulated in vivo, following anti-TNF therapy, and may reflect changes in matrix turnover.

Inhibition of histone deacetylases antagonized FGF2 and IL-1beta effects on MMP expression in human articular chondrocytes

Fibroblast growth factor-2 (FGF2) and interleukin-1beta (IL-1beta) stimulate the expression of matrix metalloproteinases (MMPs) in articular chondrocytes, which may contribute to cartilage degradation and development of osteoarthritis. Histone deacetylases (HDACs) have recently been implicated in the regulation of MMP gene expression. To investigate the functional involvement of HDACs in the signaling pathway of FGF2 and IL-1beta, we examined the effects of HDAC inhibition on activities of FGF2 or IL-1beta on gene expression of MMP-1, MMP-3, MMP-13, a disintegrin and metalloproteinase with thrombospondin motifs-5 (ADAMTS5), collagen type II, and aggrecan. Human articular chondrocyte cultures were treated with FGF2 or IL-1beta in the presence or absence of HDAC inhibitor (trichostatin A, TSA). Gene expression levels after treatments were assessed using quantitative real time PCR. Results showed that FGF2 and IL-1beta both increased MMP-1 and -13 expression, while IL-1beta also increased MMP-3 mRNA levels. These effects were attenuated in the presence of TSA in a dose dependent manner. In contrast to the effects on MMPs, FGF2 decreased mRNA levels of ADAMTS-5, which was not affected by HDAC inhibition. FGF2, IL-1beta, and TSA inhibited expression of aggrecan, while TSA also decreased mRNA levels of collagen type II. These findings showed that HDAC inhibition antagonized FGF2 and IL-1beta induced MMP expression. Combination of FGF2 and the HDAC inhibitor decreases both anabolic and catabolic genes, which may slow the cartilage turnover and be beneficial for maintaining cartilage integrity.

Inhibition of TGF-beta1 suppresses motility and invasiveness of oral squamous cell carcinoma cell lines via modulation of integrins and down-regulation of matrix-metalloproteinases

Transforming growth factor (TGF)-beta1 is a multifunctional polypeptide that regulates a variety of cellular processes. Several studies have indicated that it is associated with epithelial-mesenchymal transition, angiogenesis, migration and metastases in many types of malignant tumors. We have used a wound-healing assay and a Matrigel invasion assay to evaluate the effects of TGF-beta1 and TGF-beta receptor I kinase inhibitor (TRI) on the cell motility and invasiveness of the human oral squamous cell carcinoma (OSCC) cell lines SAS-L1 and HSC-3. While TGF-beta1 enhanced the migration and invasion of OSCC cells, TRI significantly suppressed the migration and invasion of these cells. Exogenous TGF-beta1 up-regulated the activity of type IV collagenase (gelatinase A and gelatinase B), whereas TRI down-regulated the activity of these matrix metalloproteinases. Western blot analysis revealed that TGF-beta1 enhanced the expression of alpha5, alphav, beta1, beta6 and alphavbeta3 integrin subunits, and these enhanced integrins were down-regulated by treatment with TRI. These results suggest that the inhibition of TGF-beta1 suppresses motility and invasiveness of OSCC cells via modulation of integrins and matrix-metalloproteinases. Therefore, targeting the TGF-beta1 signaling pathway could be beneficial in the treatment of patients with OSCC.

Inhibition effect of Guizhi-Fuling-decoction on the invasion of human cervical cancer

AIM OF THE STUDY

Guizhi-Fuling-decoction (GZFLD), a traditional Chinese medical formulation, exerts an anti-tumor effect, but the mechanisms of its action on invasive tumor inhibition have not been documented. The aims of this study were to identify the inhibitory effect of GZFLD on the invasive of cervical cancer and to elucidate the extensional mechanisms of its action.

MATERIALS AND METHOD

The invasive ability of HeLa cells was tested with Transwell chamber. The expressions and activities of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) were measured by zymography/reverse zymography, RT-PCR and Western blot analysis. Establish tumor-bearing mice model to assess the ability of GZFLD to inhibit tumor growth and angiopoiesis in vivo.

RESULTS

We have found that GZFLD suppressed the invasive ability of HeLa cells, inhibited MMPs expressions and activities, increased TIMPs expressions and activities, and furthermore restored the MMPs-TIMPs balance in HeLa cells in a concentration-dependent manner. Meanwhile in vivo, GZFLD had significantly inhibited tumor growth and angiopoiesis.

CONCLUSION

In general, our results showed that GZFLD had inhibited the invasion of cervical cancer both in vitro and vivo. The inhibitory effects may be associated with restoring the MMPs-TIMPs balance, and then suppressing the degradation of extracellular matrix.

The plasminogen fibrinolytic pathway is required for hematopoietic regeneration

Hematopoietic stem cells within the bone marrow exist in a quiescent state. They can differentiate and proliferate in response to hematopoietic stress (e.g., myelosuppression), thereby ensuring a well-regulated supply of mature and immature hematopoietic cells within the circulation. However, little is known about how this stress response is coordinated. Here, we show that plasminogen (Plg), a classical fibrinolytic factor, is a key player in controlling this stress response. Deletion of Plg in mice prevented hematopoietic stem cells from entering the cell cycle and undergoing multilineage differentiation after myelosuppression, leading to the death of the mice. Activation of Plg by administration of tissue-type plasminogen activator promoted matrix metalloproteinase-mediated release of Kit ligand from stromal cells, thereby promoting hematopoietic progenitor cell proliferation and differentiation. Thus, activation of the fibrinolytic cascade is a critical step in regulating the hematopoietic stress response.

CPU0213, a novel endothelin receptor antagonist, suppresses the upregulation of matrix metalloproteinases and connexin 43 in hyperthyroid myocardium

It has been verified that endothelin-1 (ET-1) activates matrix metalloproteinase (MMP) in the process of myocardial remodeling. Sustained high thyroid hormone level gives rise to left ventricular hypertrophy, in which the ET-1 system is probably involved.We attempted to study the effects of CPU0213, a novel endothelin receptor antagonist, on myocardial remodeling induced by high dose L-thyroxin. Adult male Sprague-Dawley rats were treated with L-thyroxin (0.4 mg/kg/d, sc) for 10 days to induce left ventricular hypertrophy. Asubset of rats was given CPU0213 from day 6 to 10. Alterations in MMP, tissue inhibitor of metalloproteinase (TIMP), and connexin 43 were measured by reverse transcription polymerase chain reaction (RT-PCR), zymography, and Western blot assays. L-thyroxin treatment resulted in increased mRNA expression and MMP-2 and MMP-9 activities, along with decreased TIMP-1 and TIMP-2 mRNA expression. CPU0213 suppressed the increased activity of MMP, and prevented the downregulation of TIMP expression. The expression of connexin 43 was upregulated at both mRNAand protein levels after L-thyroxin treatment, which was attenuated by CPU0213. In addition, L-thyroxin caused upregulation of mRNA expression of preproET-1 (ppET-1) and endothelin converting enzyme (ECE). These results suggest that the ET receptors mediate high dose L-thyroxin induced myocardial remodeling by changing MMP, TIMP activities and connexin 43.

Effect of photodynamic therapy on the extracellular matrix and associated components

In many countries, photodynamic therapy (PDT) has been recognized as a standard treatment for malignant conditions (for example, esophageal and lung cancers) and non-malignant ones such as age-related macular degeneration and actinic keratoses. The administration of a non-toxic photosensitizer, its selective retention in highly proliferating cells and the later activation of this molecule by light to form reactive oxygen species that cause cell death is the principle of PDT. Three important mechanisms are responsible for the PDT effectiveness: a) direct tumor cell kill; b) damage of the tumor vasculature; c) post-treatment immunological response associated with the leukocyte stimulation and release of many inflammatory mediators like cytokines, growth factors, components of the complement system, acute phase proteins, and other immunoregulators. Due to the potential applications of this therapy, many studies have been reported regarding the effect of the treatment on cell survival/death, cell proliferation, matrix assembly, proteases and inhibitors, among others. Studies have demonstrated that PDT alters the extracellular matrix profoundly. For example, PDT induces collagen matrix changes, including cross-linking. The extracellular matrix is vital for tissue organization in multicellular organisms. In cooperation with growth factors and cytokines, it provides cells with key signals in a variety of physiological and pathological processes, for example, adhesion/migration and cell proliferation/differentiation/death. Thus, the focus of the present paper is related to the effects of PDT observed on the extracellular matrix and on the molecules associated with it, such as, adhesion molecules, matrix metalloproteinases, growth factors, and immunological mediators.

In vivo effects of insulin and free fatty acids on matrix metalloproteinases in rat aorta

OBJECTIVE

Obesity is associated with insulin resistance, hyperinsulinemia, elevated plasma free fatty acid (FFA), and increased risk for atherosclerotic vascular disease (ASVD). A part of this increased risk may be due to enhanced activation of matrix metalloproteinases (MMPs). Here, we have examined the effects of physiologically elevated levels of insulin and FFA on three MMPs and their inhibitors (tissue inhibitors of MMP [TIMPs]) in aortic tissue of male rats during euglycemic-hyperinsulinemic clamping.

RESEARCH DESIGN AND METHODS

Four-hour euglycemic-hyperinsulinemic clamps with infusion of saline/glycerol, lipid/heparin, or insulin with or without lipid/heparin were performed in alert unrestrained male rats.

RESULTS

Hyperinsulinemia increased MMP-2 ( approximately 6-fold), MMP-9 ( approximately 13-fold), membrane type 1-MMP (MT1-MMP; approximately 8-fold) (all Western blots), and gelatinolytic activity (zymography) of MMP-2 (2-fold), while not affecting TIMP-1 and TIMP-2. Insulin increased IRS-1-associated PI 3-kinase (PI3K), extracellular signal-regulated kinases 1/2 (ERK1/2), and c-jun NH(2)-terminal kinase (JNK) (by Western blots with phospho-specific antibodies). FFA augmented the insulin-mediated increases in MMP-2 (from approximately 6- to approximately 11-fold), MMP-9 (from approximately 3- to approximately 23-fold), MT1-MMP (from approximately 8- to approximately 20-fold), MMP-2 gelatinolytic activity (from 2- to 3-fold), and JNK and p38 mitogen-activated protein kinase (MAPK) activities but decreased insulin-mediated activation of PI3K and ERK1/2. Raising FFA without raising insulin affected neither MMPs nor TIMPs.

CONCLUSIONS

FFA augmented insulin stimulation of the MMP/TIMP balance of three proatherogenic MMPs and increased activities of two MAPKs (JNK and p38 MAPK), both of which are known to stimulate the production of proinflammatory cytokines. This may, over time, increase degradation of extracellular matrix and together with inflammatory changes promote development of ASVD.

The impact of aryl hydrocarbon receptor signaling on matrix metabolism: implications for development and disease

The aryl hydrocarbon receptor (AhR) was identified as the receptor for polycyclic aromatic hydrocarbons and related compounds. However, novel data indicate that the AhR binds a variety of unrelated endogenous and exogenous compounds. Although AhR knockout mice demonstrate that this receptor has a role in normal development and physiology, the function of this receptor is still unclear. Recent evidence suggests that AhR signaling also alters the expression of genes involved in matrix metabolism, specifically the matrix metalloproteinases (MMPs). MMP expression and activity is critical to normal physiological processes that require tissue remodeling, as well as in mediating the progression of a variety of diseases. MMPs not only degrade structural proteins, but are also important mediators of cell signaling near or at the cell membrane through exposure of cryptic sites, release of growth factors, and cleavage of receptors. Therefore, AhR modulation of MMP expression and activity may be critical, not only in pathogenesis, but also in understanding the endogenous function of the AhR. In this review we will examine the data indicating a role for the AhR-signaling pathway in the regulation of matrix remodeling, and discuss potential molecular mechanisms.

Influence of retinoids on skin fibroblasts metabolism in vitro

The most dangerous environmental factor for our skin condition is ultraviolet light radiation. Chronic exposition to ultraviolet light can induce epidermal atrophy, keratosis, depigmentation and dysplasia. In the dermis, UV light causes dramatic up-regulation of extracellular matrix-degrading enzymes. Matrix metalloproteinases (MMPs) are engaged in collagen, elastin and other extracellular matrix components degradation. In addition, to increase level of destructive enzymes, UV light has been shown to decrease collagen production. As a consequence of UV impact on skin, it shows signs of aging including loss of tone and elasticity, increased skin fragility, blood vessels weakness and wrinkles. The most dangerous effect of UV on skin is an increased risk of melanoma and other skin cancers. Retinoids are well known antiaging agents. For many years this vitamin has been used for the prevention and treatment of photoaging. Retinoids abolish cellular atypia, increase compacting of the stratum corneum and reduce skin hyperpigmentation caused by sun light. Recent evidence suggests that retinoids also play a role in the prevention of aging, because of its inhibitory effects on metalloproteinases expression. The aim of this study was to examine if all-trans-retinoic acid (ATRA) effects MMP-1, MMP-2, MMP-3 and MMP-14 gene expression in fibroblasts cultured in vitro.

Evidence for species differences in the regulation of MMPs by all-trans retinoic acid in cytokine-stimulated chondrocytes

In inflammatory conditions, chondrocytes produce large amounts of matrix metalloproteases (MMP) and nitric oxide (NO) thought to contribute to joint degradation. We tested the ability of all-trans retinoic acid (ATRA, a retinoic acid receptor (RAR) agonist) to modulate these inflammatory genes in chondrocytes from humans or rats, chosen as representative of animal models of arthritis. All RAR subtypes and RXR-alpha or -beta were expressed at the mRNA level in both species, although IL-1beta (10 ng/ml) inhibited RAR subtypes more markedly in rat than in human cells. ATRA (300 or 1000 nM) inhibited IL-1-induced expression of iNOS and nitrites level in both species, although the NO pathway was induced maximally in rat cells. ATRA displayed controversial effects on MMPs between rat and human chondrocytes, especially for MMP-9 expression. The effects of ATRA were irrelevant to the nuclear translocation of AP-1. The present data underlines that retinoids have a species-dependent impact on IL-1-induced responses in chondrocytes, suggesting that extrapolation of their pharmacological properties from animal cells has a poor relevance to clinical situation.

A bioactively modified fatty acid improves survival and impairs metastasis in preclinical models of acute leukemia

PURPOSE

Polyunsaturated fatty acids (PUFA) and the sulfur-substituted fatty acid tetradecylthioacetic acid (TTA) inhibit proliferation and induce apoptosis in lymphoma and leukemic cell lines, but it is unknown if they can modify leukemogenesis in the intact organism.

EXPERIMENTAL DESIGN

We now examined the effects of PUFA and TTA in rats transplanted with either acute promyelocytic leukemia or acute T-cell leukemia. The rats were randomized to isoenergetic diets containing either lard (control), omega3 (n-3) PUFA, or TTA.

RESULTS

Whereas TTA prolonged survival (P < 0.05) in both types of rat leukemia, n-3 PUFA had no significant effect compared with controls. Only TTA inhibited (P < 0.05) leukemic infiltration in the bone marrow and spleen, probably due to apoptosis of the leukemic cells. Plasma metalloproteinase activity, a marker of metastatic activity, was significantly reduced in TTA-fed rats only.

CONCLUSIONS

Dietary intake of TTA, but not of n-3 PUFA, in rats with acute leukemia, prolonged their survival. TTA intake was also associated with reduced leukemic cell burden as well as diminished extramedullar dissemination. TTA represents a modified fatty acid that exerts unique effects on malignant hematopoietic cells, and the present study indicates that TTA may have a therapeutic potential in patients with acute leukemias.

Serum levels of sex steroid hormones and matrix metalloproteinases after intra-articular glucocorticoid treatment in female patients with rheumatoid arthritis

OBJECTIVES

To study metalloproteinase activity and sex steroid hormone production in serum after intra-articular glucocorticoid treatment for knee synovitis.

METHODS

18 female patients with rheumatoid arthritis and synovitis of the knee with need for intra-articular glucocorticoid treatment were included in this study. Serum samples of matrix metalloproteinases (MMP-1/TIMP complex and MMP-3), dehydroepiandrosterone sulphate, testosterone, oestradiol, steroid hormone binding globulin, follicle stimulating hormone and luteinising hormone were collected before injection with 20 mg triamcinolone hexacetonide, and 24 h, 48 h, 1 week and 2 weeks after injection, respectively.

RESULTS

Serum levels of MMP-3 were significantly decreased, but MMP-1/TIMP complex was unaffected. Dehydroepiandrosterone sulphate, testosterone and oestradiol levels all decreased and tended to return to baseline levels during the observation period. Steroid hormone binding globulin, follicle stimulating hormone and luteinising hormone levels were unchanged.

CONCLUSIONS

Intra-articular glucocorticoid treatment causes a temporary, but considerable suppression of sex steroid hormone secretion. The reduction of MMP-3 indicates an inhibition of the inflammatory, but probably also the cartilage destructive processes within the treated joint.

Leukotriene D4 enhances the function of endothelin-1-primed fibroblasts

Airway inflammation is accompanied by structural changes, termed remodeling, that lead to lung dysfunction over the long term. Although both endothelin-1 (ET-1) and cysteinyl leukotrienes (CysLTs) appear to be involved in airway remodeling in several lung diseases, how these molecules interact remains largely unknown. In this study, we examined the effects of leukotriene (LT) D(4) on the function of ET-1-primed fibroblasts. ET-1 at 10(-7) M up-regulated the expression of the CysLT receptors at both the mRNA and protein levels in human lung fibroblasts. LTD(4) enhanced matrix metalloproteinase-2 and pro-collagen production, and alpha-smooth muscle actin expression of ET-1-primed fibroblasts, but had little or no effect on unprimed fibroblasts. The CysLT1 receptor antagonist montelukast completely abrogated the effects of LTD(4). Our data suggested that LTD(4) may act as a precipitating factor during ET-1-mediated airway remodeling and that CysLT1 receptor antagonists may have a role in preventing aberrant extracellular matrix degradation.

Protective effect of Liuwei Dihuang decoction on early diabetic nephropathy induced by streptozotocin via modulating ET-ROS axis and matrix metalloproteinase activity in rats RETRACTED ARTICLE

We aimed to investigate the effects of Liuwei Dihuang decoction (LW) on the endothelin-1-reactive oxidative species (ET-ROS) system and matrix metalloproteinases (MMPs) in the early diabetic nephropathy induced by streptozotocin (STZ) in rats. Rats were divided into six groups as follows: the control group, the untreated model group, the treated groups with the LW (5, 10 and 15 g kg(-1), p.o.) and the aminoguanidine-treated group (100 mg kg(-1), orally). The treatment was performed for 4 weeks, beginning on the fifth week after one intraperitoneal injection of STZ (65 mg kg(-1)). In the untreated model group, increased blood glucose, decreased plasma insulin level and an impaired renal function were observed. There was an altered redox system shown by an increased malondialdehyde and decreased activity of glutathione peroxidase and superoxide dismutase in the renal cortex. An enhanced inducible nitric oxide synthetase, total nitric oxide synthase and constitutive nitric oxide synthase and a declined nitric oxide were found. An increased extracellular matrix was indicated by an abnormality of MMP-2 and MMP-9 activities and an increase in hydroxyproline. An up-regulated ET-1 level and increased mRNA expression of endothelin-converting enzyme, preproET-1 and ET( A) receptor were presented in the affected renal cortex, but no change in ET(B) receptor mRNA. The LW was most effective in reversing these changes in diabetic rats and was as effective as aminoguanidine. The benefits of the extracts in relieving the abnormalities in early diabetic nephropathy are likely to be mediated by suppression of the renal ET-ROS system and escalating the activity of MMPs.

Analysis of biologic surrogate markers from a Children's Oncology Group Phase I trial of gefitinib in pediatric patients with solid tumors

This trial evaluated the effect of gefitinib on the plasma circulating levels of epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), matrix metalloproteinases (MMP)-2 and -9 of patients treated on a pediatric Phase I trial. Complete plasma correlative studies were obtained from 16 of the 25 enrolled patients. There was a trend for lower MMP-2 baseline levels in patients with partial response or stable disease. The Ewing sarcoma from the only patient with partial response lacked egfr mutations. Gefitinib did not induce any significant variation in the levels of the assessed parameters, and none of these determinations showed significant predictive or prognostic value.

Effect of angiotensin II on primary cardiac fibroblast matrix metalloproteinase activities

Left ventricular dysfunction is associated with reperfusion injury occurring during open-heart surgery. There is an increased secretion of angiotensin II (Ang II) and increased matrix metalloproteinases (MMPs) activities associated with open-heart surgery that may affect the cardiac extracellular matrix (ECM). The goal of this study was to determine the effects of Ang II and selective angiotensin II receptor (AT1-R and AT2-R) blockers on the enzymatic activities of MMPs in primary adult murine cardiac fibroblasts (CF). Our hypothesis is that Aug II, with and without a selective receptor blocker, differentially affects CF MMPs activities. The CF were treated with Ang II (10(-6) M) and doses of AT1-R and AT2-R blockers (losartan and PD123319, respectively) at doses of 10(-7) to 10(-5) M for 48 hours. The Ang II-stimulated CF reduced collagenase activities by only 24% (p = 0.004); however, the MMP-2 and MMP-9 gelatinase activities were reduced by 42% and 39%, respectively (p = 0.022). The losartan dose dependently increased MMP-2 (p = 0.02) and MMP-9 (ns). PD123319 at 10(-5) M significantly reduced MMP-2 and MMP-9 activities compared with the Ang II group (p = 0.014 and p = 0.02, respectively). The doses of PD123319 at 10(-6) and 10(-7) M increased the MMP-2 and MMP-9 enzymatic activities significantly above the Ang II only group. Thus, Ang II and AT1-R and AT2-R differentially affect the collagenase and gelatinase MMPs activities released by cardiac fibroblasts.

Nicotine increases the collagen-degrading ability of human gingival fibroblasts

BACKGROUND AND OBJECTIVE

The objective of this study was to determine the effects that nicotine and the combination of nicotine and Porphyromonas gingivalis supernatant have on human gingival fibroblast-mediated collagen degradation.

MATERIAL AND METHODS

Human gingival fibroblasts were cultured with 25-500 microg/ml of nicotine in collagen-coated six-well plates. On days 1-5, the conditioned media was collected for zymography and western blot analyses of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). The cells were then removed and the collagen cleavage visualized by Coomassie blue staining. To examine the combined effect, 250 microg/ml of nicotine and 10% v/v culture supernatant of P. gingivalis ATCC 33277 were added to the human gingival fibroblasts. The mRNA levels of multiple MMPs and TIMPs were monitored.

RESULTS

Nicotine increased the human gingival fibroblast-mediated collagen cleavage. The MMP-14 and MMP-2 produced by the nicotine-treated human gingival fibroblasts more readily underwent zymogen activation. Nicotine treatment resulted in TIMP-2 redistribution to the cell surface. The mRNAs of multiple MMPs and TIMPs were unaltered by nicotine. An additive collagen cleavage effect was observed when the human gingival fibroblasts were treated with both nicotine and P. gingivalis.

CONCLUSION

Nicotine increased human gingival fibroblast-mediated collagen degradation, in part through the activation of membrane-associated MMPs. Nicotine and P. gingivalis had an additive effect on human gingival fibroblast-mediated collagen degradation.

Matrix metalloproteases: underutilized targets for drug delivery

Pathophysiological molecules in the extracellular environment offer excellent targets that can be exploited for designing drug targeting systems. Matrix metalloproteases (MMPs) are a family of extracellular proteolytic enzymes that are characterized by their overexpression or overactivity in several pathologies. Over the last two decades, the MMP literature reveals heightened interest in the research involving MMP biology, pathology and targeting. This review describes various strategies that have been designed to utilize MMPs for targeting therapeutic entities. Key factors that need to be considered in the successful design of such systems have been identified based on the analyses of these strategies. Development of targeted drug delivery using MMPs has been steadily pursued; however, drug delivery efforts using these targets need to be intensified and focused to realize the clinical application of the fast developing fundamental MMP research.

Induction of matrix metalloproteinase gene expression in an endothelial cell line by direct interaction with malignant cells

Mouse endothelial TKD2 cells in monolayers were cocultured with various human cell lines for 24 h, and the expression of several secreted matrix metalloproteinases (MMP) and cell adhesion molecules was examined by real-time reverse transcription-polymerase chain reaction using mouse-specific primers. Coculture with normal fibroblasts did not elicit the expression of these molecules, but coculture with cancer cells induced the expression of MMP-3, MMP-9 and MMP-10 mRNA in endothelial cells, and in normal mouse embryonic fibroblasts. The induction of MMP mRNA was dependent on direct cell adhesion, as separate culture of A549 cells in Boyden chambers did not induce MMP mRNA, and neutralizing antibody against VLA-4 abolished the induction. An inhibitor of phosphatidylinositol-3-phosphate kinase strongly suppressed the induction of MMP-3, MMP-9 and MMP-10 mRNA, and expression of the dominant-negative mutant of phosphatidylinositol-3-phosphate kinase also decreased the induction. It was suggested that intracellular reactive oxygen species (ROS) levels were increased in TKD2 cells following adhesion to cancer cells. ROS scavengers decreased the levels of MMP induction, and roterone, an inhibitor of mitochondrial complex I, strongly suppressed the induction of MMP-3, MMP-9 and MMP-10. The depletion of mitochondria in TKD2 cells decreased the induction of MMP-9, but the induction of MMP-3 and MMP-10 was not affected. These results indicate that the adhesion of cancer cells to endothelial cells activates several distinct signaling pathways to induce MMP gene expression, and the pathways for MMP-3, MMP-9 and MMP-10 are partly different. For the induction of MMP-9, mitochondria participate in induction, possibly through the production of ROS.

In vitro effects of non-steroidal anti-inflammatory drugs on cytokine, prostanoid and matrix metalloproteinase production by interface membranes from loose hip or knee endoprostheses

OBJECTIVE

To study the effects of the non-steroidal anti-inflammatory drugs (NSAIDs) aceclofenac, piroxicam, tenoxicam and indomethacin on cytokine, matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs) and prostaglandin E2 (PGE2) production, by interface membranes (IFT), obtained at revision surgery for aseptic loosening of total joint arthroplasty. Involvement of these soluble factors is well documented and probably, a pharmaceutically induced inhibition of them might retard loosening.

METHODS

IFTs from 10 patients with a loose hip or knee endoprosthesis were collected. The possibility of septic loosening was thoroughly excluded by histopathologic and microbiologic evaluation. IFTs were cultured in the absence or presence of the tested drugs and the levels of the soluble mediators were determined, using electrophoretic and enzyme-linked immunosorbent assay techniques. Paracetamol was used as neutral drug.

RESULTS

All NSAIDs exhibited a pronounced inhibitory effect upon the production of interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-alpha). This specific effect on IL-6 is reported in the literature for the first time. The majority of NSAIDs also induced the production of IL-1beta in an adequate portion of samples. These drugs did not have a clear effect on MMP synthesis, but they had a stimulatory tendency on TIMP-1 production. Paracetamol, significantly decreased the synthesis of TNF-alpha and that of the gelatinases.

CONCLUSION

Our in vitro results are encouraging, since it appears that the action of NSAIDs, globally considered, may be beneficial upon the loosening process. The inhibitory effect of paracetamol upon TNF-alpha and gelatinases is intriguing. Our data, if supported by similar observations, probably justify performance of long-term clinical trials.

Understanding the role of proteases and pH in wound healing

Recent research into chronic and non-healing wounds has helped increase our knowledge and understanding of the destructive processes that occur in wounds. Advanced dressings, such as protease-modulating dressings, have been developed to reduce the effects of these processes and re-establish a molecular balance in the wound bed. To use these dressings accurately, nurses need to understand the events that occur at a molecular level in the wound bed and the phases of wound healing so that they can act appropriately if a wound becomes 'stuck' in one of these phases.

Matrix metalloproteinases: influence on smooth muscle cells and atherosclerotic plaque stability

Atherosclerotic plaque rupture, with subsequent occlusive thrombosis, is the underlying cause of most cases of sudden cardiac death. Matrix metalloproteinases (MMPs) are thought to mediate the progression of stable atherosclerotic lesions to an unstable phenotype that is prone to rupture through the destruction of strength-giving extracellular matrix (ECM) proteins. Smooth muscle cells secrete and deposit ECM proteins and are, therefore, considered protective against atherosclerotic plaque destabilization. However, similar to inflammatory cells (e.g., macrophages), smooth muscle cells release numerous MMPs that are capable of digesting ECM proteins. Thus, the interaction of smooth muscle cells and MMPs in atherosclerotic plaques is complex and not fully understood. Recently, research into the roles of MMPs and their endogenous inhibitors (tissue inhibitors of metalloproteinases), and their effects on smooth muscle behavior during plaque destabilization has been aided by the development of reproducible animal models of plaque instability. A plethora of studies has demonstrated that MMPs directly modulate smooth muscle behavior with both beneficial and deleterious effects on atherosclerotic plaque stability, in addition to their canonical effects on ECM remodeling. Consequently, broad-spectrum MMP inhibition may inhibit plaque-stabilizing mechanisms, such as smooth muscle cell growth, while conversely retarding ECM destruction and subsequent rupture. Hence the development of selective MMP inhibitors, that spare inhibitory effects on smooth muscle cell function, may be useful therapies to prevent plaque rupture and in this regard MMP-12 appears to be a particularly attractive target.

Metzincins, including matrix metalloproteinases and meprin, in kidney transplantation

Chronic allograft nephropathy, including chronic rejection, remains one of the major causes of renal allograft failure. Amongst other mediators, metzincins, such as matrix metalloproteinases (MMP), direct extracellular matrix metabolism and cell proliferation. Thus, we hypothesized, that these proteolytic enzymes are differentially regulated in chronic renal transplant rejection in rats and in human renal allograft nephropathy. Our studies demonstrated on the experimental level and in humans an overall up-regulation of MMP, tissue inhibitors of metalloproteinases (TIMP) and related enzymes as a result of rejection processes. Thus, metzincins may represent novel markers and therapeutic targets with respect to renal allograft rejection.

Induction of matrix metalloproteinase, cytokines and chemokines in rat cortical astrocytes exposed to plasminogen activators

Plasminogen activators are used in thrombolytic stroke therapy. However, it is increasingly recognized that they have other actions besides fibrinolysis. In this study, we assess potential pro-inflammatory effects of tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA) in rat cortical astrocytes. Both uPA and tPA induced rapid dose-dependent upregulation in MMP-2 and MMP-9, as demonstrated by zymography of conditioned media. In addition, a multiplex ELISA array demonstrated that patterned responses in chemokines and cytokines were also evoked. Exposure to tPA induced elevations in secreted MIP-2, MCP-1 and GRO/KC. Exposure to uPA induced elevations in secreted IFN-gamma, TNF-alpha, GMCSF, MIP-1alpha, MIP-2, MIP-3alpha, MCP-1, RANTES and fractalkine. These data suggest that plasminogen activators may trigger selected pro-inflammatory responses at the neurovascular interface. Whether these effects influence thrombolytic stroke therapy warrants further investigation.

[Articular cartilage in osteoarthritic patients: effects of diclofenac, celecoxib and glucosamine sulfate on inflammatory markers]

Osteoarthritis is a chronic and progressive joint disease. It is established by a complex process involving mechanical and biological alterations of the musculoskeletal system, which are generated by a great variety of interactions between genetic factors and extrinsic injuries. The pathogenesis of this disease is related to an increased and divergent production of inflammatory markers and proteolytic enzymes that promote the degradation and destruction of the extracellular matrix of articular and periarticular tissues. Cartilage samples were taken from 20 osteoarthritic patients during programmed surgical interventions. The cartilage samples were cultured in Dulbecco-Eagle medium, with or without the addition of NSAIDs or modulators of chondrocyte metabolism. The content of nitric oxide in the supernatant was quantified using the Griess reaction; the concentration of MMP-1 was quantified via double-sandwich ELISA. Untreated chondrocyte cultures produced 1950 +/- 665 ng/ml MMP-1. With the addition of Diclofenac this value decreased to 1140 +/- 155 ng/ml, although this difference was not statistically significant (p < 0.06). However, in the presence of Celecoxib the level significantly dropped to 760 +/- 75 ng/ml (p < 0.01). Although the addition ofglucosamine did not produce such a noticeable reduction in the level of MMP-1 (950 +/- 89 ng/ml), it was statistically significant (p < 0.05). On the contrary, none of the drugs (Diclofenac, Celecoxib, Glucosamine) modified the level of nitric oxide which had a mean value of 47.3 +/- 4.9 microM in the control samples. This investigation evidenced the inability of Diclofenac to significantly modify the production of proteolytic enzymes in osteoarthritic chondrocyte cultures. However, both Celecoxib and Glucosamine significantly reduced the production of MMP-1. On the contrary, none of the drugs used in this study managed to modify the concentration of nitric oxide. To the present day, no drugs have been found to be efficient in altering the natural course of the disease, requiring further investigation.

The effect of epidermal growth factor on matrix metalloproteinases and tissue inhibitors of metalloproteinase gene expression in cultured human gingival fibroblasts

OBJECTIVE

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) play a role in the breakdown of the extracellular matrix during normal physiological processes, and in pathological processes, including periodontitis. The aim of this study was to evaluate the effect of epidermal growth factor (EGF) on the expression of MMPs and TIMPs in cultured human gingival fibroblasts.

METHODS

Fibroblasts were stimulated with 10(-3), 10(-6) or 10(-12)M EGF for 24h; untreated fibroblasts served as controls. Alterations in the expression of MMP-1, 2, 3, 7, 11, TIMP-1 and 2 were evaluated using real-time PCR and Western blotting. beta-Actin expression was used as a reference to normalize gene expression.

RESULTS

Increased MMP-1, 3, 7 and 11 expressions were observed at all EGF concentrations (p<0.05). At the lowest EGF concentration, MMP-1, 3 and 7 presented the lowest expression and MMP-11 presented the greatest expression; at higher EGF concentrations, MMP-1, 3 and 7 presented greater up-regulation, and MMP-11 lower up-regulation (p<0.05). Protein expression was similarly regulated by EGF: increased up-regulation of MMP-1, 3 and 7 was observed with increasing EGF concentrations, except for MMP-11 that exhibited greater up-regulation at the lower EGF concentration. The gene expression of MMP-2, TIMP-1 and 2 was not affected by EGF (p<0.05).

CONCLUSIONS

We conclude that EGF regulates expression for MMP-1, 3, 7 and 11 in a dose-dependent manner, suggesting that EGF may play a role in periodontal destruction and wound repair.