Effects of coenzyme Q10 supplementation on inflammation, angiogenesis, and oxidative stress in breast cancer patients: a systematic review and meta-analysis of randomized controlled- trials

BACKGROUND/OBJECTIVE

Systemic inflammation and oxidative stress (OS) are associated with breast cancer. CoQ10 as an adjuvant treatment with conventional anti-cancer chemotherapy has been demonstrated to help in the inflammatory process and OS. This systematic review and meta-analysis of randomized clinical trials (RCTs) aimed to evaluate the efficacy of CoQ10 supplementation on levels of inflammatory markers, OS parameters, and matrix metalloproteinases/tissue inhibitor of metalloproteinases (MMPs/TIMPs) in patients with breast cancer.

METHODS

A systematic literature search was carried out using electronic databases, including PubMed, Web of Science, Scopus, Google Scholar, and Embase, up to December 2020 to identify eligible RCTs evaluating the effect of CoQ10 supplementation on OS biomarkers, inflammatory cytokines, and MMPs/TIMPs. From 827 potential reports, 5 eligible studies consisting of 9 trials were finally included in the current meta-analysis. Quality assessment and heterogeneity tests of the selected trials were performed using the PRISMA checklist protocol and the I² statistic, respectively. Fixed and random-effects models were assessed based on the heterogeneity tests, and pooled data were determined as the standardized mean difference (SMD) with a 95% confidence interval (CI).

RESULTS

Our meta-analysis of the pooled findings for inflammatory biomarkers of OS and MMPs showed that CoQ10 supplementation (100 mg/day for 45-90 days) significantly decreased the levels of VEGF [SMD: - 1.88, 95% CI: (- 2. 62 to - 1.13); I² = 93.1%, p < 0.001], IL-8 [SMD: - 2.24, 95% CI: (- 2.68 to - 1.8); I² = 79.6%, p = 0.001], MMP-2 [SMD: - 1.49, 95% CI: (- 1.85 to - 1.14); I² = 76.3%, p = 0.005] and MMP-9 [SMD: - 1.58, 95% CI: (- 1.97 to - 1.19); I² = 79.6%, p = 0.002], but no significant difference was observed between CoQ10 supplementation and control group on TNF-α [SMD: - 2.30, 95% CI: (- 2.50 to - 2.11); I² = 21.8%, p = 0.280], IL-6 [SMD: - 1.56, 95% CI: (- 1.73 to - 1.39); I² = 0.0%, p = 0.683], IL-1β [SMD: - 3.34, 95% CI: (- 3.58 to - 3.11); I² = 0.0%, p = 0.561], catalase (CAT) [SMD: 1.40, 95% CI: (1.15 to 1.65); I² = 0.0%, p = 0.598], superoxide dismutase (SOD) [SMD: 2.42, 95% CI: (2.12 to 2.71); I² = 0.0%, p = 0.986], glutathione peroxidase (GPx) [SMD: 2.80, 95% CI: (2.49 to 3.11); I² = 0.0%, p = 0.543]], glutathione (GSH) [SMD: 4.71, 95% CI: (4.26 to 5.16); I² = 6.1%, p = 0.302] and thiobarbituric acid reactive substances (TBARS) [SMD: - 3.20, 95% CI: (- 3.53 to - 2.86); I² = 29.7%, p = 0.233].

CONCLUSION

Overall, the findings showed that CoQ10 supplementation reduced some of the important markers of inflammation and MMPs in patients with breast cancer. However, further studies with controlled trials for other types of cancer are needed to better understand and confirm the effect of CoQ10 on tumor therapy.

Expression and characterization of tissue inhibitor of metalloproteinase 4 from complex canine mammary carcinomas

All four members of the tissue inhibitors of metalloproteinase (TIMP) family have been reported to be over-expressed in breast cancer cells in vitro. Dysregulation of TIMP-4 expression predicts poor prognosis in cancers. The present study evaluated the association of the expression levels of TIMP-4 with mammary tumor development in dogs, measured by real-time quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Mammary tissue samples were collected from healthy canine mammary gland and from tumor subjects. TIMP-4 expression was found to be upregulated (5.856 times) in complex canine mammary carcinomas. Also, TIMP-4 mature peptide was expressed heterologously in E. coli. The recombinant protein was purified by Ni- NTA affinity chromatography and further confirmed by western blotting. The rTIMP-4 was found to be functionally active and could inhibit matrix metalloproteinase 11(MMP-11) activity. Immunization of mice with rTIMP-4 resulted in increased antigen specific serum antibody titer, and this serum could be suitably used to detect and quantify the protein in sera of dogs with mammary tumors. TIMP-4 could act as a marker of canine mammary tumors. To the best of our knowledge, this is the first report of heterologous expression of TIMP-4 from complex canine mammary carcinomas.

Protective Role for Tissue Inhibitor of Metalloproteinase-4, a Novel Peroxisome Proliferator-Activated Receptor-γ Target Gene, in Smooth Muscle in Deoxycorticosterone Acetate-Salt Hypertension

Loss of peroxisome proliferator-activated receptor-γ (PPARγ) function causes hypertension, whereas its activation lowers blood pressure. Evidence suggests that these effects may be attributable to PPARγ activity in the vasculature. However, the specific transcriptional targets of PPARγ in vessels remain largely unidentified. In this study, we examined the role of smooth muscle PPARγ during salt-sensitive hypertension and investigated its transcriptional targets and functional effect. Transgenic mice expressing dominant-negative PPARγ (S-P467L) in smooth muscle cells were more prone to deoxycorticosterone acetate-salt-induced hypertension and mesenteric arterial dysfunction compared with nontransgenic controls. Despite similar morphometry at baseline, vascular remodeling in conduit and small arteries was enhanced in S-P467L after deoxycorticosterone acetate-salt treatment. Gene expression profiling in aorta and mesenteric arteries revealed significantly decreased expression of tissue inhibitor of metalloproteinase-4 (TIMP-4) in S-P467L. Expression of TIMP-4 was increased by deoxycorticosterone acetate-salt treatment, but this increase was ablated in S-P467L. Interference with PPARγ activity either by treatment with a PPARγ inhibitor, GW9662, or by expressing P467L PPARγ markedly suppressed TIMP-4 in primary smooth muscle cells. PPARγ binds to a PPAR response element (PPRE) in chromatin close to the TIMP-4 gene in smooth muscle cells, suggesting that TIMP-4 is a novel target of PPARγ. The interference with PPARγ and decrease in TIMP-4 were accompanied by an increase in total matrix metalloproteinase activity. PPARγ-mediated loss of TIMP-4 increased, whereas overexpression of TIMP-4 decreased smooth muscle cell migration in a scratch assay. Our findings highlight a protective mechanism induced by PPARγ in deoxycorticosterone acetate-salt treatment, establishing a novel mechanistic link between PPARγ and TIMP-4.

Chrysanthemum indicum ethanolic extract inhibits invasion of hepatocellular carcinoma via regulation of MMP/TIMP balance as therapeutic target

Hepatocellular carcinoma (HCC) is an aggressive cancer with a dismal outcome largely due to metastasis and postsurgical recurrence. Thus, the inhibition of invasion and metastasis is of great importance in its therapies. Medicinal plants or ethnopharmacology used in folklore medicine continue to be an important source of discovery and development of novel or potential therapeutic agents for treatment of cancer. Chrysanthemum indicum, one of the medicinal plants or ethnopharmacology, is being used for treatment of many diseases including cancer. However, this plant molecular mechanisms underlining the anti-metastatic effects have not been well documented. In this study, Chrysanthemum indicum ethanolic extract (CIE) significantly suppressed proliferation and invasion of MHCC97H cells, one of the HCC cell lines with high metastatic potential, in a dose-dependent manner. CIE markedly decreased MMP-2 and MMP-9 expression, increased simultaneously TIMP-1, and TIMP-2 expression further restoring their balance in the cancer cells. The present study indicates that CIE reduced MHCC97H cell metastatic capability, in part at least, through decrease of the MMP expression, simultaneous increase of the TIMP expression, further restoring their balance as therapeutic target in HCC. It is suggested that Chrysanthemum indicum is a potential novel therapeutic medicinal plant for treatment of HCC or cancer invasion and metastasis.

Peroxynitrite inactivates human-tissue inhibitor of metalloproteinase-4

Peroxynitrite, via post-translational modifications to target proteins, contributes to cardiovascular injury and cancer. Since tissue inhibitor of metalloproteinase-4 (TIMP-4), the activity of which is impaired in both pathological conditions, has several amino acid residues susceptible to peroxynitrite, we investigated its role as a potential target of peroxynitrite. Peroxynitrite-induced nitration and oligomerization of TIMP-4 attenuated its inhibitory activity against MMP-2 activity and endothelial or tumor cell invasiveness. Moreover, cell treatment with peroxynitrite promoted the nitration of endogenous TIMP-4. HPLC/ESI-MS/MS analysis of peroxynitrite-treated TIMP-4 showed modifications at Y114, Y195, Y188 and Y190. In conclusion, TIMP-4 nitration might be a potential mechanism contributing to cardiovascular disease and cancer.

Functional analysis of matrix metalloproteinases and tissue inhibitors of metalloproteinases differentially expressed by variants of human HT-1080 fibrosarcoma exhibiting high and low levels of intravasation and metastasis

The role of tumor-derived matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinase (TIMPs) in cancer cell dissemination was analyzed by employing two variants of human HT-1080 fibrosarcoma, HT-hi/diss and HT-lo/diss, which differ by 50-100-fold in their ability to intravasate and metastasize in the chick embryo. HT-hi/diss and HT-lo/diss were compared by quantitative reverse transcription-PCR and Western blot analyses for mRNA and protein expression of nine MMPs (MMP-1, -2, -3, -7, -8, -9, -10, -13, and -14) and three TIMPs (TIMP-1, -2, and -3) in cultured cells in vitro and in primary tumors in vivo. MMP-1 and MMP-9 were more abundant in the HT-hi/diss variant, both in cultures and in tumors, whereas the HT-lo/diss variant consistently expressed higher levels of MMP-2, TIMP-1, and TIMP-2. Small interfering RNA-mediated down-regulation of MMP-2 and TIMP-2 increased intravasation of HT-lo/diss cells. Coordinately, treatment of the developing HT-hi/diss tumors with recombinant TIMP-1 and TIMP-2 significantly reduced HT-hi/diss cell intravasation. However, a substantial increase of HT-hi/diss dissemination was observed upon small interfering RNA-mediated down-regulation of three secreted MMPs, including the interstitial collagenase MMP-1 and the two gelatinases, MMP-2 and MMP-9, but not the membrane-tethered MMP-14. The addition of recombinant pro-MMP-9 protein to the HT-hi/diss tumors reversed the increased intravasation of HT-hi/diss cells, in which MMP-9 was stably down-regulated by short hairpin RNA interference. This rescue did not occur if the pro-MMP-9 was stoichiometrically complexed with TIMP-1, pointing to a direct role of the MMP-9 enzyme in regulation of HT-hi/diss intravasation. Collectively, these findings demonstrate that tumor-derived MMPs may have protective functions in cancer cell intravasation, i.e. not promoting but rather catalytically interfering with the early stages of cancer dissemination.

Elastolysis induces collagenolysis in a gingival lamina propria model

Elastin peptides were previously reported to increase MMP expression in several cell types. We found binding of these peptides to their receptors led to enhanced MMP-3 and MMP-1 expression, but not activation, in human gingival fibroblasts cultured on plastic dishes. We hypothesized that these peptides, in a more physiological environment, might additionally trigger an MMP-3/MMP-1 activation cascade, leading to matrix lysis, as occurs in periodontitis. To test this hypothesis, we used contracted and attached lattices as gingival lamina propria equivalents. In such 3D models, supplementation of elastin peptides and plasminogen triggered an MMP-3/MMP-1 activation cascade and significant down-regulation of TIMPs production, further leading to intense collagen degradation. We propose that elastolysis, as occurs in periodontitis, potentiates collagenolysis, thus promoting disease progression.

Fibulins 3 and 5 antagonize tumor angiogenesis in vivo

Lethal tumor growth and progression cannot occur without angiogenesis, which facilitates cancer cell proliferation, survival, and dissemination. Fibulins (FBLN) 5 and 3 are widely expressed extracellular matrix proteins that regulate cell proliferation in a context-specific manner. Reduced FBLN-5 expression has been associated with cancer formation and progression in humans, whereas its constitutive expression antagonizes endothelial cell angiogenic sprouting in vitro. Thus, FBLN-5 may suppress tumorigenesis by preventing tumor angiogenesis. FBLN-3 is homologous to FBLN-5 and expressed in endothelial cells, yet its role in tumorigenesis and angiogenesis is unknown. We find FBLN-3 expression to be altered in some human tumors and that its constitutive expression in endothelial cells inhibited their proliferation, invasion, and angiogenic sprouting, as well as their response to vascular endothelial growth factor as measured by p38 mitogen-activated protein kinase activation. In endothelial cells, both FBLNs (a) reduced angiogenic sprouting stimulated by basic fibroblast growth factor (bFGF); (b) inhibited matrix metalloproteinase expression and activity; and (c) stimulated tissue inhibitor of metalloproteinase expression. More importantly, both FBLNs prevented angiogenesis and vessel infiltration into bFGF-supplemented Matrigel plugs implanted in genetically normal mice, as well as decreased the growth and blood vessel density in tumors produced by MCA102 fibrosarcoma cells implanted s.c. into syngeneic mice. Our findings establish FBLN-3 and FBLN-5 as novel angiostatic agents capable of reducing tumor angiogenesis and, consequently, tumor growth in vivo and suggest that these angiostatic activities may one day be exploited to combat tumor angiogenesis and metastasis in cancer patients.

Lupinus albus, a novel vegetable extract with metalloproteinase inhibitory properties: a potential periodontal therapy

BACKGROUND

In this study we examine the properties of a vegetable extract from seeds of Lupinus albus (LU 105). In previous works we demonstrated that LU 105 reduced the expression, by gingival fibroblasts, of both matrix metalloproteinase (MMP)-2 and MMP-9. We decided to study the impact of LU 105 on cell proliferation and morphology. Using organ culture media we also studied the MMP and tissue inhibitors of metalloproteinases (timp) expression AND THE cytokines secretion.

METHODS

Healthy and inflamed gingival biopsies were placed in appendage culture with or without LU 105. The organ culture media were analyzed using Western blottings (MMP-1, MMP-2, MMP-3, MMP-7, MMP-9, MMP-13, TIMP-1, and TIMP-2) and gelatine zymography. A reverse transcription polymerase chain reaction (RT-PCR) was also performed on healthy and inflamed gingival biopsies, which were maintained in culture with or without LU 105 0.1%. Then, we decided to determine the amount of cytokines present in the organ culture media such as interleukin (IL)-1 beta, IL-4, IL-6, transforming growth factor (TGF)-beta, and tumor necrosis factor (TNF)-alpha.

RESULTS

When gingival biopsies derived from inflamed tissues were cultured with LU 105 0.1% in the culture media, the MMP and TIMP expression and activity decreased significantly when compared to cultures without LU 105. Moreover, we did not note any statistical difference in the cell proliferation compared with human gingival fibroblast cultures without LU 105. Furthermore, IL-1 beta, IL-6, TGF-beta, and TNF-alpha amounts in the culture media decreased significantly, whereas IL-4 increased significantly when LU 105 0.1% was added to the culture media.

CONCLUSION

LU 105, a novel metalloproteinase inhibitor with few consequences on cell proliferation and morphology, is a vegetable extract with potential clinical capacity.

Expression and functional properties of antibodies to tissue inhibitors of metalloproteinases (TIMPs) in rheumatoid arthritis

Tissue inhibitors of matrix metalloproteinases (TIMPs) regulate the breakdown of extracellular matrix components and play an important role in tissue remodelling and growth, in both physiological and pathological conditions. We studied the autoimmune response to TIMPs in patients with rheumatoid arthritis (RA). Eighty-nine paired blood and synovial fluid samples from patients with RA were assessed for their reactivity with recombinant tissue inhibitors of metalloproteinases (TIMPs) 1 to 4 by an ELISA and were compared with blood from 62 healthy controls and 21 synovial fluid samples from patients with degenerative joint diseases. Presence of antibodies was established as the absorbance of the sample more than 2 standard deviations above the mean of the controls. In addition, immunoglobulin G (IgG) from blood samples of RA patients possessing TIMP antibodies was isolated on protein A-sepharose and tested for the in vitro ability to neutralize TIMP-2-dependent effects on metalloproteinase 9 (MMP9). Anti-TIMP antibodies were found in 56% of RA samples but in only 5% of the controls (P < 0.005). RA patients had high frequencies of antibodies against all TIMPs except TIMP-3. TIMP-2 antibodies were most frequently found (33%), being significantly more prevalent (P = 0.024) in patients with nonerosive than erosive RA. TIMP-1 antibodies were significantly more often found in synovial fluid samples than in the matched blood samples (P < 0.025). Importantly, the IgG fraction containing TIMP antibodies down-regulated the TIMP-2 inhibitory effect, thereby supporting MMP9 activity in vitro. In the present study, we show that RA patients frequently develop autoimmune response to TIMPs that may act as a functionally significant regulator of MMP activity and thereby of joint destruction.

Heterogeneous effects of tissue inhibitors of matrix metalloproteinases on cardiac fibroblasts

The balance between matrix metalloproteinases (MMPs) and their natural inhibitors, the tissue inhibitors of metalloproteinases (TIMPs), plays a critical role in cardiac remodeling. Although a number of studies have characterized the pathophysiological role of MMPs in the heart, very little is known with respect to the role of TIMPs in the heart. To delineate the role of TIMPs in the heart we examined the effects of adenovirus-mediated overexpression of TIMP-1, -2, -3, and -4 in cardiac fibroblasts. Infection of cardiac fibroblasts with adenoviral constructs containing human recombinant TIMP (AdTIMP-1, -2, -3, and -4) provoked a significant (P < 0.0001) 1.3-fold in increase in bromodeoxyuridine (BrdU) incorporation. Similarly, treatment of cardiac fibroblasts with AdTIMP-1-, -2-, -3-, and -4-conditioned medium led to a 1.2-fold increase in BrdU incorporation (P < 0.0001) that was abolished by pretreatment with anti-TIMP-1, -2, -3, and -4 antibodies. The effects of TIMPs were not mimicked by treating the cells with RS-130830, a broad-based MMP inhibitor, suggesting that the effects of TIMPs were independent of their ability to inhibit MMPs. Infection with AdTIMP-1, -2, -3, and -4 led to a significant increase in alpha-smooth muscle actin staining, consistent with TIMP-induced phenotypic differentiation into myofibroblasts. Finally, infection with AdTIMP-2 resulted in a significant increase in collagen synthesis, whereas infection with AdTIMP-3 resulted in a significant increase in fibroblast apoptosis. TIMPs exert overlapping as well as diverse effects on isolated cardiac fibroblasts. The observation that TIMPs stimulate fibroblast proliferation as well as phenotypic differentiation into myofibroblasts suggests that TIMPs may play an important role in tissue repair in the heart that extends beyond their traditional role as MMP inhibitors.

Suppression of matrix metalloproteinase production from nasal fibroblasts by fluticasone propionate in vitro

OBJECTIVE

To examine the influence of fluticasone propionate (FP) on matrix metalloproteinase (MMP) production from nasal polyp fibroblasts in vitro.

MATERIAL AND METHODS

Fibroblasts derived from five nasal polyps were stimulated with tumor necrosis factor (TNF)-alpha in the presence of various concentrations of FP. The influence of FP on MMP production was assessed by examining the levels of MMP-2 and -9 in culture supernatants using ELISA. We also examined the influence of FP on MMP mRNA expression using reverse transcriptase polymerase chain reaction.

RESULTS

The addition of FP caused significant suppression of MMP-2 and -9 production from nasal polyp fibroblasts in response to TNF-alpha stimulation. MMP mRNA expression was also suppressed by the addition of FP to cell cultures. The minimum concentration of the agent required to cause suppression was 10(-5) M.

CONCLUSION

These results suggest that the inhibitory action of FP on tissue remodeling may underlie the clinical efficacy of corticosteroids in nasal polyposis.

Human T-cell lymphotropic virus type I-infected cells extravasate through the endothelial barrier by a local angiogenesis-like mechanism

Extravasation of tumor cells through the endothelial barrier is a critical step in cancer metastasis. Human T-cell lymphotropic virus type I (HTLV-I)-associated adult T-cell leukemia/lymphoma (ATL) is an aggressive disease characterized by visceral invasion. We show that ATL and HTLV-I-associated myelopathy patients exhibit high plasma levels of functional vascular endothelial growth factor and basic fibroblast growth factor. The viral oncoprotein Tax transactivates the promoter of the gap-junction protein connexin-43 and enhances gap-junction-mediated heterocellular communication with endothelial cells. The interaction of HTLV-I-transformed cells with endothelial cells induces the gelatinase activity of matrix metalloproteinase (MMP)-2 and MMP-9 in endothelial cells and down-regulates the tissue inhibitor of MMP. This leads to subendothelial basement membrane degradation followed by endothelial cell retraction, allowing neoplastic lymphocyte extravasation. We propose a model that offers a mechanistic explanation for extravasation of HTLV-I-infected cells: after specific adhesion to endothelia of target organs, tumor cells induce a local and transient angiogenesis-like mechanism through paracrine stimulation and direct cell-cell communication with endothelial cells. This culminates in a breach of the endothelial barrier function, allowing cancer cell invasion. This local and transient angiogenesis-like sequence that may facilitate visceral invasion in ATL represents a potential target for ATL therapy.

Differential effects of modern immunosuppressive agents on the development of intimal hyperplasia

Modern immunosuppressive agents such as tacrolimus and rapamycin are claimed to be associated with a reduction in vascular narrowing, a central feature of chronic rejection. This study assesses the effect of cyclosporine, tacrolimus and rapamycin on the development of intimal thickening, fibrosis-associated genes and deposition of extracellular matrix (ECM) proteins in a model of intimal hyperplasia. Male Sprague-Dawley rats received either no treatment or 5 mg/kg cyclosporine, 0.1 mg/kg tacrolimus or 0.05 mg/kg rapamycin. Animals underwent left common carotid balloon angioplasty, and intima medial ratios, pro-fibrotic gene expression and ECM accumulation were calculated at 14 and 28 days. Cyclosporine was associated with increased intimal thickening compared to controls ( P < 0.004). Tacrolimus had no effect on intimal thickening, whilst rapamycin significantly inhibited intimal thickening at both 14 and 28 days ( P < 0.004 and P < 0.026, respectively). All groups significantly inhibited matrix metalloproteinase (MMP)-2, MMP-9, tissue inhibitor of metalloproteinases (TIMP)-1, transforming growth factor (TGF)-beta and collagen III expression at 14 days ( P < 0.001), but increased ECM deposition. However, rapamycin marginally reduced ECM deposition compared to cyclosporine ( P < 0.06). Treatment with cyclosporine was associated with worsening of vascular narrowing, whilst rapamycin showed a beneficial reduction in intimal thickening. Treatment with all immunosuppressive agents resulted in increased ECM deposition. Rapamycin may halt the progression of vascular narrowing compared to both cyclosporine and tacrolimus.

Decreased tissue inhibitor of metalloproteinase in the endometrium of women using depot medroxyprogesterone acetate: a role for altered endometrial matrix metalloproteinase/tissue inhibitor of metalloproteinase balance in the pathogenesis of abnormal uterine bleeding?

BACKGROUND

Abnormal uterine bleeding is commonly associated with progestin-only contraceptives, including depot medroxyprogesterone acetate (DMPA), and remains the main reason why these agents are discontinued. Matrix metalloproteinases (MMP), enzymes which degrade specific extracellular matrix components, and leukocytes are implicated in menstruation. Alteration in endometrial MMP-9 and leukocytes has been described in users of other progestin-only contraceptives, suggesting a potential role in the pathogenesis of abnormal uterine bleeding.

METHODS

This study describes the immunohistochemical localization of MMP-9, the tissue inhibitors of metalloproteinases (TIMP)-1, TIMP-2 and TIMP-3, and leukocytes [CD3+ T lymphocytes, CD68+ macrophages and CD56+ uterine natural killer cells (uNK cells)] in the endometrium of women using DMPA. Comparison is made with perimenstrual endometria from normal cycling women.

RESULTS

Similar to the perimenstrual period, an influx of MMP-9 positive cells (identified as neutrophils and CD3+ T cells on the basis of dual immunofluorescence), macrophages and uNK cells was observed in the endometrium of DMPA users. However, significantly more endometrial T lymphocytes were observed in DMPA users. Immunoreactive TIMP, present in all endometrial compartments, demonstrated a significantly decreased immunostaining intensity score in endometrial epithelium (TIMP-1 and TIMP-2), stroma (TIMP-1, TIMP-2 and TIMP-3), endothelium (TIMP-1 and TIMP-2) and vascular smooth muscle (TIMP-1) of DMPA users compared with controls. No correlation was observed between the parameters studied and bleeding patterns reported by subjects.

CONCLUSIONS

These findings provide additional evidence for the importance of the MMP/TIMP balance in the loss/maintenance of endometrial integrity and in the complex pathological mechanisms involved in the troubling side-effect of menstrual bleeding disturbance.

Effect of avocado and soybean unsaponifiables on gelatinase A (MMP-2), stromelysin 1 (MMP-3), and tissue inhibitors of matrix metalloproteinase (TIMP- 1 and TIMP-2) secretion by human fibroblasts in culture

BACKGROUND

In inflamed periodontal tissues, gingival fibroblasts are able to express matrix metalloproteinases (MMPs) and their natural inhibitors, tissue inhibitors of matrix metalloproteinases (TIMPs). They can also respond to growth factors and cytokines. In this study, the in vitro effects of avocado and soybean unsaponifiable residues (ASU), their fractions (avocado unsaponifiable [ASF] or soy unsaponifiable [SSF]) on MMP-2 and MMP-3, and the activity and secretion of their inhibitors TIMP-1 and TIMP-2 were investigated using cultured human gingival fibroblasts.

METHODS

Gingival fibroblasts were cultured for 72 hours with ASU, ASF, and SSF at concentrations of 0. 1, 0.5, 2.5, 5, and 10 microgram/ml of culture medium, after pretreatment or no pretreatment for 1 hour with interleukin-1beta (IL-1beta). MMP-2 and MMP-3 were detected and quantified in the culture media after zymography and image analysis. TIMP-1, TIMP-2, MMP-2, and MMP-3 were also evidenced by dot blotting and quantified by image analysis.

RESULTS

In the absence of IL-1beta, a slight decrease in the secretion of MMP-2 was observed with lower doses of ASU, ASF, and SSF. The decrease of MMP-3 secretion was clearly marked with all fractions especially at low concentrations (0.1 and 2.5 microgram/ml). A slight decrease in TIMP-2 secretion was seen for low doses of ASU, ASF, and SSF, while a small increase was seen at higher concentrations. Concerning TIMP-1, no significant variation was observed in culture medium for low concentrations, and a decrease was noted for 5 and 10 microgram/ml of ASU, ASF, and SSF. As anticipated, IL-1beta induced a marked release of MMP-2, MMP-3, and TIMP-1, but no variation for TIMP-2 was seen. ASU, ASF, and SSF reversed the IL-1beta effect on gingival fibroblasts for MMP-2 and MMP-3, particularly with doses varying from 0.1 to 2.5 microgram/ml and for TIMP-1, particularly with doses varying from 2.5 to 10 microgram/ml.

CONCLUSIONS

These findings suggest a potential role for avocado and soy unsaponifiable extracts to prevent the deleterious effects of IL-1beta that occur during periodontal diseases.

TGF-beta3-induced palatogenesis requires matrix metalloproteinases

Cleft lip and palate syndromes are among the most common congenital malformations in humans. Mammalian palatogenesis is a complex process involving highly regulated interactions between epithelial and mesenchymal cells of the palate to permit correct positioning of the palatal shelves, the remodeling of the extracellular matrix (ECM), and subsequent fusion of the palatal shelves. Here we show that several matrix metalloproteinases (MMPs), including a cell membrane-associated MMP (MT1-MMP) and tissue inhibitor of metalloproteinase-2 (TIMP-2) were highly expressed by the medial edge epithelium (MEE). MMP-13 was expressed both in MEE and in adjacent mesenchyme, whereas gelatinase A (MMP-2) was expressed by mesenchymal cells neighboring the MEE. Transforming growth factor (TGF)-beta3-deficient mice, which suffer from clefting of the secondary palate, showed complete absence of TIMP-2 in the midline and expressed significantly lower levels of MMP-13 and slightly reduced levels of MMP-2. In concordance with these findings, MMP-13 expression was strongly induced by TGF-beta3 in palatal fibroblasts. Finally, palatal shelves from prefusion wild-type mouse embryos cultured in the presence of a synthetic inhibitor of MMPs or excess of TIMP-2 failed to fuse and MEE cells did not transdifferentiate, phenocopying the defect of the TGF-beta3-deficient mice. Our observations indicate for the first time that the proteolytic degradation of the ECM by MMPs is a necessary step for palatal fusion.

Biological considerations in lung cancer

Our understanding of lung cancer biology has rapidly expanded in recent years. Lung cancer, unlike most human cancers, can be traced to an environmental risk factor in the majority of cases, and this fact is reflected in the vast number of genetic alterations discovered in lung tumors whose pathogenesis is believed to be mediated by carcinogen exposure. The discovery of these alterations has led to a greater understanding of tumor development. The dramatic progress in the understanding of the genetic and molecular basis of oncogenesis and the induction of immunity has led to a rejuvenation of efforts to apply this new knowledge to this common and refractory disease. Further, the resurgent interest in cancer immunology and tumor-host interactions holds promise for the development of new approaches to treatment based on harvesting the immune systems ability to recognize these alterations. Hopefully, this understanding will lead to novel approaches with real and convincing clinical efficacy once some of these strategies are tested in carefully performed randomized clinical trials with appropriate power to detect meaningful differences.

How matrix metalloproteinases regulate cell behavior

The matrix metalloproteinases (MMPs) constitute a multigene family of over 25 secreted and cell surface enzymes that process or degrade numerous pericellular substrates. Their targets include other proteinases, proteinase inhibitors, clotting factors, chemotactic molecules, latent growth factors, growth factor-binding proteins, cell surface receptors, cell-cell adhesion molecules, and virtually all structural extracellular matrix proteins. Thus MMPs are able to regulate many biologic processes and are closely regulated themselves. We review recent advances that help to explain how MMPs work, how they are controlled, and how they influence biologic behavior. These advances shed light on how the structure and function of the MMPs are related and on how their transcription, secretion, activation, inhibition, localization, and clearance are controlled. MMPs participate in numerous normal and abnormal processes, and there are new insights into the key substrates and mechanisms responsible for regulating some of these processes in vivo. Our knowledge in the field of MMP biology is rapidly expanding, yet we still do not fully understand how these enzymes regulate most processes of development, homeostasis, and disease.

Thioredoxin alters the matrix metalloproteinase/tissue inhibitors of metalloproteinase balance and stimulates human SK-N-SH neuroblastoma cell invasion

Thioredoxin (Trx) inhibited tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 activity with an approximate IC50 of 0.3 microM, matrix metalloproteinase (MMP)-2 activity with an approximate IC50 of 2 microM but did not inhibit MMP-9 activity. This differential capacity of Trx to inhibit TIMP and MMP activity resulted in the promotion of MMP-2 and MMP-9 activity in the presence of molar TIMP excess. Inhibition of TIMP and MMP-2 activity by Trx was dependent upon thioredoxin reductase (TrxR), was abolished by Trx catalytic site mutation and did not result from TIMP or MMP-2 degradation. HepG2 hepatocellular carcinoma cells induced to secrete Trx inhibited TIMP activity in the presence of TrxR. SK-N-SH neuroblastoma cells secreted TrxR, which inhibited TIMP and MMP-2 activity in the presence of Trx. Trx stimulated SK-N-SH invasive capacity in vitro in the absence of exogenous TrxR. This study therefore identifies a novel extracellular role for the thioredoxin/thioredoxin reductase redox system in the differential inhibition of TIMP and MMP activity and provides a novel mechanism for altering the TIMP/MMP balance that is of potential relevance to tumor invasion.

Endogenous hepatocyte growth factor ameliorates chronic renal injury by activating matrix degradation pathways

BACKGROUND

Hepatocyte growth factor (HGF) has been shown to promote tubule repair and renal regeneration following acute injury; however, whether HGF also modulates the development and progression of chronic renal diseases that are characterized by progressive tissue fibrosis is uncertain. To examine this question, this study investigated the functional consequence of blocking endogenous HGF signaling in vivo in a model of chronic renal disease. The effects of HGF on the processes of matrix synthesis and degradation in cultured renal epithelial cells were also examined.

METHODS

The level of activity of the HGF/c-met axis was examined in rats following 5/6 nephrectomy at multiple time points. To determine the effects of HGF in modulating chronic renal injury, HGF action was blocked in remnant kidney rats using an anti-HGF antibody. The effects of HGF on extracellular matrix (ECM) synthesis and degradation were examined in renal epithelial cells by (35)S-methionine labeling, Western blotting, and zymographic analysis.

RESULTS

An increase in renal and systemic production of HGF coupled with an increase in renal c-met was observed in rats with remnant kidneys. When HGF action was blocked by the administration of an anti-HGF antibody, rats experienced a rapid decrease in glomerular filtration rate and increased renal fibrosis. Kidney sections from the antibody-treated rats displayed a marked increase in ECM accumulation and in alpha-smooth muscle actin-positive cells in both the interstitium and tubular epithelium. In vitro studies revealed that HGF reduced net ECM accumulation by human proximal tubule cells (HKC), and this effect was abolished by incubating cells with an anti-HGF antibody. HGF did not alter the ECM synthetic rate in HKC cells. Rather, it markedly increased collagenase such as matrix metalloproteinase-9 (MMP-9) protein expression, as evidenced by Western blotting and zymographic analysis. HGF also decreased the expression of tissue inhibitors of matrix metalloproteinase-1 (TIMP-1) and TIMP-2, the endogenous inhibitors of MMPs.

CONCLUSION

These results suggest that HGF is a potent antifibrogenic factor both in vitro and in vivo. Endogenous activation of HGF tends to preserve kidney structure and function in rats with chronic renal disease by activating matrix degradation pathways.

Endogenous hepatocyte growth factor ameliorates chronic renal injury by activating matrix degradation pathways

BACKGROUND

Hepatocyte growth factor (HGF) has been shown to promote tubule repair and renal regeneration following acute injury; however, whether HGF also modulates the development and progression of chronic renal diseases that are characterized by progressive tissue fibrosis is uncertain. To examine this question, this study investigated the functional consequence of blocking endogenous HGF signaling in vivo in a model of chronic renal disease. The effects of HGF on the processes of matrix synthesis and degradation in cultured renal epithelial cells were also examined.

METHODS

The level of activity of the HGF/c-met axis was examined in rats following 5/6 nephrectomy at multiple time points. To determine the effects of HGF in modulating chronic renal injury, HGF action was blocked in remnant kidney rats using an anti-HGF antibody. The effects of HGF on extracellular matrix (ECM) synthesis and degradation were examined in renal epithelial cells by (35)S-methionine labeling, Western blotting, and zymographic analysis.

RESULTS

An increase in renal and systemic production of HGF coupled with an increase in renal c-met was observed in rats with remnant kidneys. When HGF action was blocked by the administration of an anti-HGF antibody, rats experienced a rapid decrease in glomerular filtration rate and increased renal fibrosis. Kidney sections from the antibody-treated rats displayed a marked increase in ECM accumulation and in alpha-smooth muscle actin-positive cells in both the interstitium and tubular epithelium. In vitro studies revealed that HGF reduced net ECM accumulation by human proximal tubule cells (HKC), and this effect was abolished by incubating cells with an anti-HGF antibody. HGF did not alter the ECM synthetic rate in HKC cells. Rather, it markedly increased collagenase such as matrix metalloproteinase-9 (MMP-9) protein expression, as evidenced by Western blotting and zymographic analysis. HGF also decreased the expression of tissue inhibitors of matrix metalloproteinase-1 (TIMP-1) and TIMP-2, the endogenous inhibitors of MMPs.

CONCLUSION

These results suggest that HGF is a potent antifibrogenic factor both in vitro and in vivo. Endogenous activation of HGF tends to preserve kidney structure and function in rats with chronic renal disease by activating matrix degradation pathways.

Cyclic tensile strain acts as an antagonist of IL-1 beta actions in chondrocytes

Inflammatory cytokines play a major role in cartilage destruction in diseases such as osteoarthritis and rheumatoid arthritis. Because physical therapies such as continuous passive motion yield beneficial effects on inflamed joints, we examined the intracellular mechanisms of mechanical strain-mediated actions in chondrocytes. By simulating the effects of continuous passive motion with cyclic tensile strain (CTS) on chondrocytes in vitro, we show that CTS is a potent antagonist of IL-1 beta actions and acts as both an anti-inflammatory and a reparative signal. Low magnitude CTS suppresses IL-1 beta-induced mRNA expression of multiple proteins involved in catabolic responses, such as inducible NO synthase, cyclo-oxygenase II, and collagenase. CTS also counteracts cartilage degradation by augmenting mRNA expression for tissue inhibitor of metalloproteases and collagen type II that are inhibited by IL-1 beta. Additionally, CTS augments the reparative process via hyperinduction of aggrecan mRNA expression and abrogation of IL-1 beta-induced suppression of proteoglycan synthesis. Nonetheless, the presence of an inflammatory signal is a prerequisite for the observed CTS actions, as exposure of chondrocytes to CTS alone has little effect on these parameters. Functional analysis suggests that CTS-mediated anti-inflammatory actions are not mediated by IL-1R down-regulation. Moreover, as an effective antagonist of IL-1 beta, the actions of CTS may involve disruption/regulation of signal transduction cascade of IL-1 beta upstream of mRNA transcription. These observations are the first to show that CTS directly acts as an anti-inflammatory signal on chondrocytes and provide a molecular basis for its actions.