The AP-1 site and MMP gene regulation: what is all the fuss about?

Complement regulatory protein CD46 promotes bladder cancer metastasis through activation of MMP9

CD46, a transmembrane protein known for protecting cells from complement‑mediated damage, is frequently dysregulated in various types of cancer. Its overexpression in bladder cancers safeguards the cancer cells against both complement and antibody‑mediated cytotoxicity. The present study explored a new role of CD46 in facilitating cancer cell invasion and metastasis, examining its regulatory effect on matrix metalloproteases (MMPs) and their effect on the metastatic capability of bladder cancer cells. Specifically, CD46 alteration positively influenced MMP9 expression, but not MMP2, in several bladder cancer cell lines. Furthermore, CD46 overexpression triggered phosphorylation of p38 MAPK and protein kinase B (AKT), leading to enhanced activator protein 1 (AP‑1) activity via c‑Jun upregulation. The inhibition of p38 or AKT pathways attenuated the CD46‑induced MMP9 and AP‑1 upregulation, indicating that the promotion of MMP9 by CD46 involved activating both p38 MAPK and AKT. Functionally, the upregulation of MMP9 by CD46 translated to increased migratory and invasive capabilities of bladder cancer cells, as well as enhanced in vivo metastasis. Overall, the present study revealed a novel role for CD46 as a metastasis promoter through MMP9 activation in bladder cancers and highlighted the regulatory mechanism of CD46‑mediated MMP9 promotion via p38 MAPK and AKT activation.

Hepatic prohibitin 1 and methionine adenosyltransferase α1 defend against primary and secondary liver cancer metastasis

BACKGROUND & AIMS

The liver is a common site of cancer metastasis, most commonly from colorectal cancer, and primary liver cancers that have metastasized are associated with poor outcomes. The underlying mechanisms by which the liver defends against these processes are largely unknown. Prohibitin 1 (PHB1) and methionine adenosyltransferase 1A (MAT1A) are highly expressed in the liver. They positively regulate each other and their deletion results in primary liver cancer. Here we investigated their roles in primary and secondary liver cancer metastasis.

METHODS

We identified common target genes of PHB1 and MAT1A using a metastasis array, and measured promoter activity and transcription factor binding using luciferase reporter assays and chromatin immunoprecipitation, respectively. We examined how PHB1 or MAT1A loss promotes liver cancer metastasis and whether their loss sensitizes to colorectal liver metastasis (CRLM).

RESULTS

Matrix metalloproteinase-7 (MMP-7) is a common target of MAT1A and PHB1 and its induction is responsible for increased migration and invasion when MAT1A or PHB1 is silenced. Mechanistically, PHB1 and MAT1A negatively regulate MMP7 promoter activity via an AP-1 site by repressing the MAFG-FOSB complex. Loss of MAT1A or PHB1 also increased MMP-7 in extracellular vesicles, which were internalized by colon and pancreatic cancer cells to enhance their oncogenicity. Low hepatic MAT1A or PHB1 expression sensitized to CRLM, but not if endogenous hepatic MMP-7 was knocked down first, which lowered CD4+ T cells while increasing CD8+ T cells in the tumor microenvironment. Hepatocytes co-cultured with colorectal cancer cells express less MAT1A/PHB1 but more MMP-7. Consistently, CRLM raised distant hepatocytes' MMP-7 expression in mice and humans.

CONCLUSION

We have identified a PHB1/MAT1A-MAFG/FOSB-MMP-7 axis that controls primary liver cancer metastasis and sensitization to CRLM.

IMPACT AND IMPLICATIONS

Primary and secondary liver cancer metastasis is associated with poor outcomes but whether the liver has underlying defense mechanism(s) against metastasis is unknown. Here we examined the hypothesis that hepatic prohibitin 1 (PHB1) and methionine adenosyltransferase 1A (MAT1A) cooperate to defend the liver against metastasis. Our studies found PHB1 and MAT1A form a complex that suppresses matrix metalloproteinase-7 (MMP-7) at the transcriptional level and loss of either PHB1 or MAT1A sensitizes the liver to metastasis via MMP-7 induction. Strategies that target the PHB1/MAT1A-MMP-7 axis may be a promising approach for the treatment of primary and secondary liver cancer metastasis.

The role of inflammatory mediators and matrix metalloproteinases (MMPs) in the progression of osteoarthritis

Osteoarthritis (OA) is a chronic musculoskeletal disorder characterized by an imbalance between (synthesis) and catabolism (degradation) in altered homeostasis of articular cartilage mediated primarily by the innate immune system. OA degenerates the joints resulting in synovial hyperplasia, degradation of articular cartilage with damage of the structural and functional integrity of the cartilage extracellular matrix, subchondral sclerosis, osteophyte formation, and is characterized by chronic pain, stiffness, and loss of function. Inflammation triggered by factors like biomechanical stress is involved in the development of osteoarthritis. In OA apart from catabolic effects, anti-inflammatory anabolic processes also occur continually. There is also an underlying chronic inflammation present, not only in cartilage tissue but also within the synovium, which perpetuates tissue destruction of the OA joint. The consideration of inflammation in OA considers synovitis and/or other cellular and molecular events in the synovium during the progression of OA. In this review, we have presented the progression of joint degradation that results in OA. The critical role of inflammation in the pathogenesis of OA is discussed in detail along with the dysregulation within the cytokine networks composed of inflammatory and anti-inflammatory cytokines that drive catabolic pathways, inhibit matrix synthesis, and promote cellular apoptosis. OA pathogenesis, fluctuation of synovitis, and its clinical impact on disease progression are presented here along with the role of synovial macrophages in promoting inflammatory and destructive responses in OA. The role of interplay between different cytokines, structure, and function of their receptors in the inter-cellular signaling pathway is further explored. The effect of cytokines in the increased synthesis and release of matrix-decomposing proteolytic enzymes, such as matrix metalloproteinase (MMPs) and a disintegrin-like and metalloproteinase with thrombospondin motif (ADAMTS), is elaborated emphasizing the potential impact of MMPs on the chondrocytes, synovial cells, articular and periarticular tissues, and other immune system cells migrating to the site of inflammation. We also shed light on the pathogenesis of OA via oxidative damage particularly due to nitric oxide (NO) via its angiogenic response to inflammation. We concluded by presenting the current knowledge about the tissue inhibitors of metalloproteinases (TIMPs). Synthetic MMP inhibitors include zinc binding group (ZBG), non-ZBG, and mechanism-based inhibitors, all of which have the potential to be therapeutically beneficial in the treatment of osteoarthritis. Improving our understanding of the signaling pathways and molecular mechanisms that regulate the MMP gene expression, may open up new avenues for the creation of therapies that can stop the joint damage associated with OA.

Dynamic changes in transcriptome during orthodontic tooth movement

OBJECTIVES

The objective of this study was to determine global changes in gene expression with next generation sequencing (NGS) in order to assess the biological effects of orthodontic tooth movement (OTM) on alveolar bone in a rat model.

MATERIALS AND METHODS

Thirty-five Wistar rats (age 14 weeks) were used in the study. The OTM was performed using closed coil Nickel-Titanium spring to apply a mesial force on maxillary first molars of 8-10 g. Three hours, 1, 3, 7 and 14 days after the placement of the appliance, rats were killed at each time point respectively. The alveolar bone, around left maxillary first molar, were excised on compression side. The samples were immediately frozen in liquid nitrogen for subsequent RNA extraction. Total RNA samples were prepared for mRNA sequencing using the Illumina kit. RNA-Seq reads were aligned to the rat genomes using the STAR Aligner and bioinformatic analysis was performed.

RESULTS

A total of 18 192 genes were determined. Day 1 has the highest number of differentially expressed genes (DEGs) observed with more upregulated than downregulated genes. A total of 2719 DEGs were identified to use as input for the algorithm. Six distinct clusters of temporal patterns were observed representing proteins that were differentially regulated indicating different expression kinetics. Principal component analysis (PCA) showed distinct clustering by time points and days 3, 7 and 14 share similar gene expression pattern.

CONCLUSIONS

Distinct gene expression pattern was observed at different time points studied. Hypoxia, inflammation and bone remodelling pathways are major mechanisms behind OTM.

BTG2 suppresses the growth and metastasis of cervical squamous cell carcinoma

BACKGROUND

Cervical cancer is the fourth most common malignancy in women, of which cervical squamous cell carcinoma (CESC) is the main pathological type of cervical cancer. B-cell translocation gene 2 (BTG2) protein has been recognized as a tumor suppressor in several cancer types. However, BTG2 expression and molecular function in CESC are unknown.

METHODS

In this study, we first assessed the expression of BTG2 in tumor tissue specimens from CESC patients using immunohistochemical staining and real-time quantitative PCR, and explored the relationship between BTG2 expression status and clinical manifestations. Next, we constructed BTG2 knockdown and overexpression CESC cell lines to observe the effects of BTG2 on CESC proliferation and metastasis at the cellular level. Finally, we employed a nude mouse xenograft tumor model in an in vivo experiment to observe the effect of BTG2 on tumorigenesis in vivo.

RESULTS

The results showed that the expression of BTG2 protein was lower in CESC tissues than in normal tissues, and high BTG2 expression was associated with better survival in CESC patients versus CESC patients. The results of cellular assays confirm that overexpression of BTG2 inhibits the proliferation, migration and metastasis of CESC cells. Nude mouse xenograft tumor model showed that overexpression of BTG2 inhibited tumor growth in vivo, and conversely knockdown of BTG2 promoted tumor growth.

CONCLUSION

In summary, our data suggest that BTG2 acts as a tumor suppressor in CESC and inhibits the growth and metastasis of CESC. BTG2 may serve as a potential prognostic marker in CESC and is expected to provide a therapeutic strategy for patients with CESC.

MMP-9 reinforces radiation-induced delayed invasion and metastasis of neuroblastoma cells through second-signaling positive feedback with NFκB via both ERK and IKK activation

Neuroblastoma (NB) progression is branded with hematogenous metastasis and frequent relapses. Despite intensive multimodal clinical therapy, outcomes for patients with progressive disease remain poor, with negligible long-term survival. Therefore, understanding the acquired molecular rearrangements in NB cells with therapy pressure and developing improved therapeutic strategies is a critical need to improve the outcomes for high-risk NB patients. We investigated the rearrangement of MMP9 in NB with therapy pressure, and unveiled the signaling that facilitates NB evolution. Radiation-treatment (RT) significantly increased MMP9 expression/activity, and the induced enzyme activity was persistently maintained across NB cell lines. Furthermore, RT-triggered NFκB transcriptional activity and this RT-induced NFκB were required/adequate for MMP9 maintenance. RT-triggered NFκB-dependent MMP9 actuated a second-signaling feedback to NFκB, facilitating a NFκB-MMP9-NFκB positive feedback cycle (PFC). Critically, MMP9-NFκB feedback is mediated by MMP9-dependent activation of IKKβ and ERK phosphotransferase activity. Beyond its tumor invasion/metastasis function, PFC-dependent MMP9 lessens RT-induced apoptosis and favors survival pathway through the activation of NFκB signaling. In addition, PFC-dependent MMP9 regulates 19 critical molecular determinants that play a pivotal role in tumor evolution. Interestingly, seven of 19 genes possess NFκB-binding sites, demonstrating that MMP9 regulates these molecules by activating NFκB. Collectively, these data suggest that RT-triggered NFκB-dependent MMP9 actuates feedback to NFκB though IKKβ- and ERK1/2-dependent IκBα phosphorylation. This RT-triggered PFC prompts MMP9-dependent survival advantage, tumor growth, and dissemination. Targeting therapy-pressure-driven PFC and/or selective inhibition of MMP9 maintenance could serve as promising therapeutic strategies for treatment of progressive NB.

Matrix Metalloproteinases Contribute to the Calcification Phenotype in Pseudoxanthoma Elasticum

Ectopic calcification and dysregulated extracellular matrix remodeling are prominent hallmarks of the complex heterogenous pathobiochemistry of pseudoxanthoma elasticum (PXE). The disease arises from mutations in ABCC6, an ATP-binding cassette transporter expressed predominantly in the liver. Neither its substrate nor the mechanisms by which it contributes to PXE are completely understood. The fibroblasts isolated from PXE patients and Abcc6-/- mice were subjected to RNA sequencing. A group of matrix metalloproteinases (MMPs) clustering on human chromosome 11q21-23, respectively, murine chromosome 9, was found to be overexpressed. A real-time quantitative polymerase chain reaction, enzyme-linked immunosorbent assay and immunofluorescent staining confirmed these findings. The induction of calcification by CaCl2 resulted in the elevated expression of selected MMPs. On this basis, the influence of the MMP inhibitor Marimastat (BB-2516) on calcification was assessed. PXE fibroblasts (PXEFs) exhibited a pro-calcification phenotype basally. PXEF and normal human dermal fibroblasts responded with calcium deposit accumulation and the induced expression of osteopontin to the addition of Marimastat to the calcifying medium. The raised MMP expression in PXEFs and during cultivation with calcium indicates a correlation of ECM remodeling and ectopic calcification in PXE pathobiochemistry. We assume that MMPs make elastic fibers accessible to controlled, potentially osteopontin-dependent calcium deposition under calcifying conditions.

Anti-Oxidative and Anti-Aging Effects of Ethanol Extract of the Officinal Breynia (Breynia vitis-idaea) In Vitro

The skin is the largest organ of the human body, and it is also the one most exposed to external environmental contaminants. The skin is the body's first defense against harmful environmental stimuli, including ultraviolet B (UVB) rays and hazardous chemicals. Therefore, proper care of the skin is required to prevent skin-related diseases and age-related symptoms. In this study, we analyzed anti-aging and anti-oxidative effects of Breynia vitis-idaea ethanol extract (Bv-EE) in human keratinocytes and dermal fibroblasts. The Bv-EE had free radical scavenging activity and decreased the mRNA expression of MMPs and COX-2 in H₂O₂- or UVB-treated HaCaT cells. The Bv-EE also inhibited AP-1 transcriptional activity and phosphorylation of c-Jun N-terminal kinase, extracellular signal-regulated kinase, and mitogen-activated protein kinase 14 (p38), which are major AP-1 activators upon H₂O₂ or UVB exposure. Furthermore, the promoter activity and mRNA expression of collagen type I (Col1A1) increased in HDF cells treated with Bv-EE, and Bv-EE recovered the collagen mRNA expression decreased by H₂O₂ or UVB exposure. These results suggest that Bv-EE has anti-oxidative effects by inhibiting the AP-1 signaling pathway, and shows anti-aging effects by upregulating collagen synthesis.

Anti-Photoaging Effect of Phaseolus angularis L. Extract on UVB-Exposed HaCaT Keratinocytes and Possibilities as Cosmetic Materials

Phaseolus angularis L. is widely cultivated and is considered a superfood because of its nutritious protein and starch contents. Nevertheless, P. angularis's effects on skin photoaging are unknown. The aim of this study was to research the effects of P. angularis seed extract (PASE) on photoaging in human keratinocytes (HaCaT) damaged by UVB radiation so as to find out whether PASE can be used as an effective anti-photoaging ingredient in cosmetic products. The antioxidant activities were assessed using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) radical scavenging, and reactive oxygen species (ROS) assays. Enzyme-linked immunosorbent assay (ELISA) analysis was used to determine the change in matrix metalloproteinase (MMP)-1, and MMP-3. The protein levels of mitogen-activated protein kinase (MAPK)/activator protein (AP)-1, transforming growth factor beta (TGF)-β/suppressor of mothers against decapentaplegic (Smad), and NF-E2-related factor (Nrf)2/antioxidant response element (ARE) were measured by western blot. As a result, PASE increased DPPH and ABTS antioxidant activities in a dose-dependent manner. Additionally, PASE treatment (100 µg/mL) significantly reverted the damage induced by UVB (125 mJ/cm²) irradiation by downregulating ROS, matrix metalloproteinase (MMP)-1, and MMP-3 secretion and expression and increasing procollagen type I production. To suppress MMP-1 and MMP-3 secretion, PASE significantly decreased UVB-induced p38 and JNK phosphorylation and phosphorylated c-Fos and c-Jun nuclear translocation. PASE promoted collagen I production by inhibiting UVB-induced TGF-β activation and Smad7 overexpression; antioxidant properties also arose from the stimulation of the Nrf2-dependent expression of the antioxidant enzymes heme oxygenase (HO)-1 and quinone oxidoreductase (NQO)-1. Our data demonstrated that PASE has the potential to prevent ROS formation induced by UVB exposure by targeting specific pathways. Thus, PASE might be a potent anti-photoaging component to exploit in developing anti-aging products.

Effects of Epigallocatechin-3-Gallate on Matrix Metalloproteinases in Terms of Its Anticancer Activity

Epidemiological studies have shown that the consumption of green tea has beneficial effects against cancer. Basic studies have provided evidence that epigallocatechin gallate (EGCG) is a major contributor to these effects. Matrix metalloproteinases (MMPs) are zinc-dependent metalloproteinases with the ability to degrade the extracellular matrix proteins and are involved in various diseases including cancer in which MMPs have a critical role in invasion and metastasis. In this review, we discuss the effects of EGCG on several types of MMPs in the context of its anticancer activity. In the promoter region, MMPs have binding sites for at least one transcription factor of AP-1, Sp1, and NF-κB, and EGCG can downregulate these transcription factors through signaling pathways mediated by reactive oxygen species. EGCG can also decrease nuclear ERK, p38, heat shock protein-27 (Hsp27), and β-catenin levels, leading to suppression of MMPs' expression. Other mechanisms by which EGCG inhibits MMPs include direct binding to MMPs to prevent their activation and downregulation of NF-κB to suppress the production of inflammatory cytokines such as TNFα and IL-1β. Findings from studies on EGCG presented here may be useful in the development of more effective anti-MMP agents, which would give beneficial effects on cancer and other diseases.

Airborne particulate matter (PM10) induces cell invasion through Aryl Hydrocarbon Receptor and Activator Protein 1 (AP-1) pathway deregulation in A549 lung epithelial cells

BACKGROUND

Particulate matter with an aerodynamic size ≤ 10 μm (PM₁₀) is a risk factor for lung cancer development, mainly because some components are highly toxic. Polycyclic aromatic hydrocarbons (PAHs) are present in PM₁₀, such as benzo[a]pyrene (BaP), which is a well-known genotoxic and carcinogenic compound to humans, capable of activating AP-1 transcription factor family genes through the Aryl Hydrocarbon Receptor (AhR). Because effects of BaP include metalloprotease 9 (MMP-9) activation, cell invasion, and other pathways related to carcinogenesis, we aimed to demonstrate that PM₁₀ (10 µg/cm²) exposure induces the activation of AP-1 family members as well as cell invasion in lung epithelial cells, through AhR pathway.

METHODS AND RESULTS

The role of the AhR gene in cells exposed to PM₁₀ (10 µg/cm²) and BaP (1µM) for 48 h was evaluated using AhR-targeted interference siRNA. Then, the AP-1 family members (c-Jun, Jun B, Jun D, Fos B, C-Fos, and Fra-1), the levels/activity of MMP-9, and cell invasion were analyzed. We found that PM₁₀ increased AhR levels and promoted its nuclear localization in A549 treated cells. Also, PM₁₀ and BaP deregulated the activity of AP-1 family members. Moreover, PM₁₀ upregulated the secretion and activity of MMP-9 through AhR, while BaP had no effect. Finally, we found that cell invasion in A549 cells exposed to PM₁₀ and BaP is modulated by AhR.

CONCLUSION

Our results demonstrated that PM₁₀ exposure induces upregulation of the c-Jun, Jun B, and Fra-1 activity, the expression/activity of MMP-9, and the cell invasion in lung epithelial cells, effects mediated through the AhR. Also, the Fos B and C-Fos activity were downregulated. In addition, the effects induced by PM₁₀ exposure were like those induced by BaP, which highlights the potentially toxic effects of the PM₁₀ mixture in lung epithelial cells.

Induction of premature senescence and a less-fibrogenic phenotype by programmed cell death 4 knockdown in the human hepatic stellate cell line Lieming Xu-2

Although programmed cell death 4 (PDCD4) was initially reported as a tumor suppressor and has been shown to inhibit cancer cell growth and metastasis, recent studies have demonstrated that loss of PDCD4 expression also induces growth inhibition by inducing apoptosis and/or cellular senescence. At present, the roles of PDCD4 in the activation and profibrogenic properties of myofibroblasts, which are critically involved in organ fibrosis, such as that in the liver, are unclear. We, therefore, investigated the roles of PDCD4 in myofibroblasts using human hepatic stellate cell line Lieming Xu-2 (LX-2). PDCD4 knockdown inhibited LX-2 proliferation and induced a senescent phenotype with increased β-galactosidase staining and p21 expression in a p53-independent manner together with downregulation of the notch signaling mediator RBJ-κ/CSL. During PDCD4 knockdown, alpha smooth muscle actin (α-SMA; an activation marker of myofibroblasts), matrix metalloproteinases MMP-1 and MMP-9, and collagen IV were upregulated, but the expression of collagen1α1 and collagen III was markedly downregulated without any marked change in the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1). These results demonstrated that knockdown of PDCD4 induced the cellular senescence phenotype and activated myofibroblasts while suppressing the profibrogenic phenotype, suggesting roles of PDCD4 in cellular senescence and fibrogenesis in the liver.

Dieckol Isolated from Eisenia bicyclis Ameliorates Wrinkling and Improves Skin Hydration via MAPK/AP-1 and TGF-β/Smad Signaling Pathways in UVB-Irradiated Hairless Mice

Repetitive exposure to ultraviolet B (UVB) is one of the main causes of skin photoaging. We previously reported that dieckol isolated from Eisenia bicyclis extract has potential anti-photoaging effects in UVB-irradiated Hs68 cells. Here, we aimed to evaluate the anti-photoaging activity of dieckol in a UVB-irradiated hairless mouse model. In this study, hairless mice were exposed to UVB for eight weeks. At the same time, dieckol at two doses (5 or 10 mg/kg) was administered orally three times a week. We found that dieckol suppressed UVB-induced collagen degradation and matrix metalloproteinases (MMPs)-1, -3, and -9 expression by regulating transforming growth factor beta (TGF-β)/Smad2/3 and mitogen-activated protein kinases (MAPKs)/activator protein-1 (AP-1) signaling. In addition, dieckol rescued the production of hyaluronic acid (HA) and effectively restored the mRNA expression of hyaluronan synthase (HAS)-1/-2 and hyaluronidase (HYAL)-1/-2 in UVB-irradiated hairless mice. We observed a significant reduction in transepidermal water loss (TEWL), epidermal/dermal thickness, and wrinkle formation in hairless mice administered dieckol. Based on these results, we suggest that dieckol, due to its anti-photoaging role, may be used as a nutricosmetic ingredient for improving skin health.

Autophagy plays an essential role in ultraviolet radiation-driven skin photoaging

Photoaging is characterized by a chronic inflammatory response to UV light. One of the most prominent features of cutaneous photoaging is wrinkling, which is due primarily to a loss of collagen fibers and deposits of abnormal degenerative elastotic material within the dermis (actinic elastosis). These changes are thought to be mediated by inflammation, with subsequent upregulation of extracellular matrix-degrading proteases and down-regulation of collagen synthesis. Autophagy is a vital homeostatic cellular process of either clearing surplus or damaged cell components notably lipids and proteins or recycling the content of the cells’ cytoplasm to promote cell survival and adaptive responses during starvation and other oxidative and/or genotoxic stress conditions. Autophagy may also become a means of supplying nutrients to maintain a high cellular proliferation rate when needed. It has been suggested that loss of autophagy leads to both photodamage and the initiation of photoaging in UV exposed skin. Moreover, UV radiation of sunlight is capable of regulating a number of autophagy-linked genes. This review will focus on the protective effect of autophagy in the skin cells damaged by UV radiation. We hope to draw attention to the significance of autophagy regulation in the prevention and treatment of skin photoaging.

The Gelatinase Inhibitor ACT-03 Reduces Gliosis in the Rapid Kindling Rat Model of Epilepsy, and Attenuates Inflammation and Loss of Barrier Integrity In Vitro

Matrix metalloproteinases (MMPs) are endopeptidases responsible for the cleavage of intra- and extracellular proteins. Several brain MMPs have been implicated in neurological disorders including epilepsy. We recently showed that the novel gelatinase inhibitor ACT-03 has disease-modifying effects in models of epilepsy. Here, we studied its effects on neuroinflammation and blood–brain barrier (BBB) integrity. Using the rapid kindling rat model of epilepsy, we examined whether ACT-03 affected astro- and microgliosis in the brain using immunohistochemistry. Cellular and molecular alterations were further studied in vitro using human fetal astrocyte and brain endothelial cell (hCMEC/D3) cultures, with a focus on neuroinflammatory markers as well as on barrier permeability using an endothelial and astrocyte co-culture model. We observed less astro- and microgliosis in the brains of kindled animals treated with ACT-03 compared to control vehicle-treated animals. In vitro, ACT-03 treatment attenuated stimulation-induced mRNA expression of several pro-inflammatory factors in human fetal astrocytes and brain endothelial cells, as well as a loss of barrier integrity in endothelial and astrocyte co-cultures. Since ACT-03 has disease-modifying effects in epilepsy models, possibly via limiting gliosis, inflammation, and barrier integrity loss, it is of interest to further evaluate its effects in a clinical trial.

Structural characterization and anti-photoaging activity of a polysaccharide from Sargassum fusiforme

In this study, a purified algal polysaccharide (P1) was isolated from Sargassum fusiforme and its structural characteristics and anti-photoaging activity were studied. Results showed that P1 had a molecular weight of 289 kDa and was mainly composed of mannuronic acid, guluronic acid and fucose with molar ratio of 7.67:2.35:1.00. The backbone of P1 was →4)-β-ManA-(1→4)-α-GulA-(1→4)-β-ManA-(1→4)-β-ManA-(1→4)-α-GulA-(1→4)-β-ManA-(1→3,4)-β-ManA-(1→ with a terminal group of α-Fucp-(1→ linked to O-3 position of →3,4)-β-ManA-(1→. In addition, P1 could inhibit the expressions of MMPs (MMP-1, MMP-3 and MMP-9) in the UVB-irradiated HaCaT cells, indicating that P1 could reduce collagen loss caused by UVB irradiation. It also reduced the contents of ROS and inflammatory factors (TNF-α, IL-6 and IL-1β), indicating that P1 could reduce the oxidative stress and inflammation response. Thus, Sargassum fusiforme polysaccharide P1 could be used as a potential functional food to relieve skin photoaging.

Species-specific sensitivity to TGFβ signaling and changes to the Mmp13 promoter underlie avian jaw development and evolution

Precise developmental control of jaw length is critical for survival, but underlying molecular mechanisms remain poorly understood. The jaw skeleton arises from neural crest mesenchyme (NCM), and we previously demonstrated that these progenitor cells express more bone-resorbing enzymes including Matrix metalloproteinase 13 (Mmp13) when they generate shorter jaws in quail embryos versus longer jaws in duck. Moreover, if we inhibit bone resorption or Mmp13, we can increase jaw length. In the current study, we uncover mechanisms establishing species-specific levels of Mmp13 and bone resorption. Quail show greater activation of and sensitivity to transforming growth factor beta (TGFβ) signaling than duck; where intracellular mediators like SMADs and targets like Runt-related transcription factor 2 (Runx2), which bind Mmp13, become elevated. Inhibiting TGFβ signaling decreases bone resorption, and overexpressing Mmp13 in NCM shortens the duck lower jaw. To elucidate the basis for this differential regulation, we examine the Mmp13 promoter. We discover a SMAD-binding element and single nucleotide polymorphisms (SNPs) near a RUNX2-binding element that distinguish quail from duck. Altering the SMAD site and switching the SNPs abolish TGFβ sensitivity in the quail Mmp13 promoter but make the duck promoter responsive. Thus, differential regulation of TGFβ signaling and Mmp13 promoter structure underlie avian jaw development and evolution.

Interleukin-1β activated c-FOS transcription factor binds preferentially to a specific allele of the matrix metalloproteinase-13 promoter and increases susceptibility to endometriosis

Endometriosis is a benign gynecological condition characterized by increased growth, inflammation, invasion, and angiogenesis, partly regulated by a class of enzymes called matrix metalloproteinases (MMPs). The importance of a few MMPs, e.g., MMP-9, -3, and -7 has been studied in endometriosis progression. Although MMP-13 plays an essential role in bone regeneration and cancer, no report has been found on the part of MMP-13 and endometriosis progression. We found the upregulation of MMP-13 expression and activity in patients having endometriosis in the eastern Indian population. In addition, the -77A/G polymorphism of the MMP13 promoter (rs: 2252070) is associated with regulating transcription and subsequent susceptibility to disease. In eastern Indian case-control groups, the effect of the -77A/G single-nucleotide polymorphism on MMP13 promoter activity and its relationship with endometriosis susceptibility was studied. The AG genotype was shown to be more predisposed to endometriosis risk than the GG genotype (p: 0.02; odds ratio [OR]: 1.65, 95% confidence interval [CI]: 1.10-2.49), also AG genotype was more frequent in late-stage patients compared to early-stage (p: 0.03, OR: 2.0, 95% CI: 1.09-3.66). Furthermore, the MMP13 gene levels were greater in AA compared to GG individuals. Additionally, MMP13 promoter-reporter experiments in cultured endometrial epithelial cells and in silico analyses both demonstrated increased transcriptional activity near the G to A transition under basal/IL-1β -induced/c-FOS overexpressed condition. Overall, c-FOS tighter binding to the A allele-carrying promoter enhances MMP13 transcription, which is further amplified by IL-1β due to increased c-FOS phosphorylation, promoting MMP-13 production and endometriosis risk.

Anti-Inflammatory Activities of an Anti-Histamine Drug, Loratadine, by Suppressing TAK1 in AP-1 Pathway

Loratadine is an anti-histamine routinely used for treating allergies. However, recent findings have shown that Loratadine may also have anti-inflammatory functions, while their exact mechanisms have not yet been fully uncovered. In this paper, we investigated whether Loratadine can be utilized as an anti-inflammatory drug through a series of in vitro and in vivo experiments using a murine macrophage cell line and an acute gastritis mouse model. Loratadine was found to dramatically reduce the expression of pro-inflammatory genes, including MMP1, MMP3, and MMP9, and inhibit AP-1 transcriptional activation, as demonstrated by the luciferase assay. Therefore, we decided to further explore its role in the AP-1 signaling pathway. The expression of c-Jun and c-Fos, AP-1 subunits, was repressed by Loratadine and, correspondingly, the expression of p-JNK, p-MKK7, and p-TAK1 was also inhibited. In addition, Loratadine was able to reduce gastric bleeding in acute gastritis-induced mice; Western blotting using the stomach samples showed reduced p-c-Fos protein levels. Loratadine was shown to effectively suppress inflammation by specifically targeting TAK1 and suppressing consequent AP-1 signaling pathway activation and inflammatory cytokine production.

PT109, a novel multi-kinase inhibitor suppresses glioblastoma multiforme through cell reprogramming: Involvement of PTBP1/PKM1/2 pathway

Glioblastoma multiforme (GBM) is the most prevalent type and lethal form of primary malignant brain tumor, accounting for about 40-50% of intracranial tumors and without effective treatments now. Cell reprogramming is one of the emerging treatment approaches for GBM, which can reprogram glioblastomas into non-tumor cells to achieve therapeutic effects. However, anti-GBM drugs through reprogramming can only provide limited symptom relief, and cannot completely cure GBM. Here we showed that PT109, a novel multi-kinase inhibitor, suppressed GBM's proliferation, colony formation, migration and reprogramed GBM into oligodendrocytes. Analysis of quantitative proteomics data after PT109 administration of human GBM cells showed significant influence of energy metabolism, cell cycle, and immune system processes of GBM-associated protein. Metabolomics analysis showed that PT109 improved the aerobic respiration process in glioma cells. Meanwhile, we found that PT109 could significantly increase the ratio of Pyruvate kinase M1/2 (PKM1/2) by reducing the level of polypyrimidine tract-binding protein 1 (PTBP1). Altogether, this work developed a novel anti-GBM small molecule PT109, which reprogramed GBM into oligodendrocytes and changed the metabolic pattern of GBM through the PTBP1/PKM1/2 pathway, providing a new strategy for the development of anti-glioma drugs.

Matrix Metalloproteinase-10 in Kidney Injury Repair and Disease

Matrix metalloproteinase-10 (MMP-10) is a zinc-dependent endopeptidase with the ability to degrade a broad spectrum of extracellular matrices and other protein substrates. The expression of MMP-10 is induced in acute kidney injury (AKI) and chronic kidney disease (CKD), as well as in renal cell carcinoma (RCC). During the different stages of kidney injury, MMP-10 may exert distinct functions by cleaving various bioactive substrates including heparin-binding epidermal growth factor (HB-EGF), zonula occludens-1 (ZO-1), and pro-MMP-1, -7, -8, -9, -10, -13. Functionally, MMP-10 is reno-protective in AKI by promoting HB-EGF-mediated tubular repair and regeneration, whereas it aggravates podocyte dysfunction and proteinuria by disrupting glomerular filtration integrity via degrading ZO-1. MMP-10 is also involved in cancerous invasion and emerges as a promising therapeutic target in patients with RCC. As a secreted protein, MMP-10 could be detected in the circulation and presents an inverse correlation with renal function. Due to the structural similarities between MMP-10 and the other MMPs, development of specific inhibitors targeting MMP-10 is challenging. In this review, we summarize our current understanding of the role of MMP-10 in kidney diseases and discuss the potential mechanisms of its actions.

Melatonin and Prostate Cancer: Anti-tumor Roles and Therapeutic Application

Melatonin is an endogenous indoleamine that has been shown to inhibit tumor growth in laboratory models of prostate cancer. Prostate cancer risk has additionally been associated with exogenous factors that interfere with normal pineal secretory activity, including aging, poor sleep, and artificial light at night. Therefore, we aim to expand on the important epidemiological evidence, and to review how melatonin can impede prostate cancer. More specifically, we describe the currently known mechanisms of melatonin-mediated oncostasis in prostate cancer, including those that relate to the indolamine's ability to modulate metabolic activity, cell cycle progression and proliferation, androgen signaling, angiogenesis, metastasis, immunity and oxidative cell status, apoptosis, genomic stability, neuroendocrine differentiation, and the circadian rhythm. The outlined evidence underscores the need for clinical trials to determine the efficacy of supplemental, adjunct, and adjuvant melatonin therapy for the prevention and treatment of prostate cancer.

Transglutaminase 2 mediates UVB-induced matrix metalloproteinase-1 expression by inhibiting nuclear p65 degradation in dermal fibroblasts

Matrix metalloproteinases (MMPs) play a key role in tissue remodelling by cleaving extracellular matrix (ECM) components. In the skin, UV irradiation increases expression of MMPs that causes dysregulation of ECM homeostasis in dermis, leading to acceleration of skin aging. However, the mediator(s) that links UV irradiation to the upregulation of MMPs have not been fully defined. Previously, we showed that UVB irradiation activated transglutaminase 2 (TG2) in keratinocytes, eliciting an inflammatory response by activating NF-κB signalling. In this study, we reported the role of TG2 in mediating the UVB-induced expression of MMP-1. In human dermal fibroblasts, UVB irradiation enhanced the expression and activity of TG2, which in turn promotes the expression of MMP-1. Analyses of MMP-1 promoter showed that activation of the NF-κB signalling pathway, rather than AP-1, was responsible for the TG2-mediated upregulation of MMP-1. Moreover, Western blot analysis revealed that TG2 increased the activity of NF-κB by inhibiting degradation of p65 in the nucleus. Furthermore, ex vivo skin from TG2-knockout mice exhibited significantly reduced levels of MMP-1 compared to that from wild-type mice. These results indicate that TG2 functions as a mediator for the UVB-induced expression of MMP-1 in dermal fibroblasts, providing a new target for preventing skin photodamage.

Glucagon-like peptide-1 receptor activation maintains extracellular matrix integrity by inhibiting the activity of mitogen-activated protein kinases and activator protein-1

Disruption of the intervertebral disc extracellular matrix (ECM) is a hallmark of intervertebral disc degeneration (IDD), which is largely attributed to excessive oxidative stress. However, there is a lack of clinically feasible approaches to promote the reconstruction of the disc ECM. Glucagon-like peptide-1 (GLP-1), a safe polypeptide hormone adopted to treat type 2 diabetes mellitus, has shown great potential for relieving oxidative stress-related damage. To our knowledge, this is the first study to reveal that exenatide, a GLP-1 receptor (GLP-1R) agonist, can upregulate disc ECM synthesis and attenuate oxidative stress-induced ECM degradation and IDD. Mechanistically, we found that exenatide inhibited the activation of mitogen-activated protein kinases (MAPK) signaling pathway and the formation of BATF/JUNs heterodimers (an index of activator protein-1 (AP-1) activity). The restoration of MAPK signaling activation reversed the protective effects of exenatide and enhanced downstream BATF/JUNs binding. BATF overexpression was also found to aggravate disc ECM damage, even in the presence of exenatide. In summary, exenatide is an effective agent that regulates ECM anabolic balance and restores disc degeneration by inhibiting MAPK activation and its downstream AP-1 activity. The present study provides a therapeutic rationale for activating the GLP-1 receptor against IDD and establishes the important role of AP-1 activity in the pathogenesis of IDD.

Dysregulated retinoic acid signaling in airway smooth muscle cells in asthma

Vitamin A deficiency has been shown to exacerbate allergic asthma. Previous studies have postulated that retinoic acid (RA), an active metabolite of vitamin A and high-affinity ligand for RA receptor (RAR), is reduced in airway inflammatory condition and contributes to multiple features of asthma including airway hyperresponsiveness and excessive accumulation of airway smooth muscle (ASM) cells. In this study, we directly quantified RA and examined the molecular basis for reduced RA levels and RA-mediated signaling in lungs and ASM cells obtained from asthmatic donors and in lungs from allergen-challenged mice. Levels of RA and retinol were significantly lower in lung tissues from asthmatic donors and house dust mite (HDM)-challenged mice compared to non-asthmatic human lungs and PBS-challenged mice, respectively. Quantification of mRNA and protein expression revealed dysregulation in the first step of RA biosynthesis consistent with reduced RA including decreased protein expression of retinol dehydrogenase (RDH)-10 and increased protein expression of RDH11 and dehydrogenase/reductase (DHRS)-4 in asthmatic lung. Proteomic profiling of non-asthmatic and asthmatic lungs also showed significant changes in the protein expression of AP-1 targets consistent with increased AP-1 activity. Further, basal RA levels and RA biosynthetic capabilities were decreased in asthmatic human ASM cells. Treatment of human ASM cells with all-trans RA (ATRA) or the RARγ-specific agonist (CD1530) resulted in the inhibition of mitogen-induced cell proliferation and AP-1-dependent transcription. These data suggest that RA metabolism is decreased in asthmatic lung and that enhancing RAR signaling using ATRA or RARγ agonists may mitigate airway remodeling associated with asthma.

Integrated Multi-Omics Investigations of Metalloproteinases in Colon Cancer: Focus on MMP2 and MMP9

Colorectal cancer (CRC) develops by genetic and epigenetic alterations. However, the molecular mechanisms underlying metastatic dissemination remain unclear and could benefit from multi-omics investigations of specific protein families. Matrix metalloproteinases (MMPs) are proteolytic enzymes involved in ECM remodeling and the processing of bioactive molecules. Increased MMP expression promotes the hallmarks of tumor progression, including angiogenesis, invasion, and metastasis, and is correlated with a shortened survival. Nevertheless, the collective role and the possible coordination of MMP members in CRC are poorly investigated. Here, we performed a multi-omics analysis of MMP expression in CRC using data mining and experimental investigations. Several databases were used to deeply mine different expressions between tumor and normal tissues, the genetic and epigenetic alterations, the prognostic value as well as the interrelationships with tumor immune-infiltrating cells (TIICs). A special focus was placed on to MMP2 and MMP9: their expression was correlated with immune markers and the interaction network of co-expressed genes disclosed their implication in epithelial to mesenchymal transition (EMT) and immune response. Finally, the activity levels of MMP2 and MMP9 in a cohort of colon cancer samples, including tissues and the corresponding sera, was also investigated by zymography. Our findings suggested that MMPs could have a high potency, as they are targeted in colon cancer, and might serve as novel biomarkers, especially for their involvement in the immune response. However, further studies are needed to explore the detailed biological functions and molecular mechanisms of MMPs in CRC, also in consideration of their expression and different regulation in several tissues.

Importance of Altered Gene Expression of Metalloproteinases 2, 9, and 16 in Acute Myeloid Leukemia: Preliminary Study

Acute myeloid leukemia is a group of hematological neoplasms characterized by a heterogeneous course and high mortality. The important factor in the neoplastic process is metalloproteinases, proteolytic enzymes capable of degrading various components of the extracellular matrix, which take an active part in modifying the functioning of the cell, including transformation to cancer cell. They interact with numerous signaling pathways responsible for the process of cell growth, proliferation, or apoptosis. In the present study, changes in the expression of MMP2, MMP9, and MMP16 genes between patients with AML and people without cancer were examined. The impact of cytogenetic changes in neoplastic cells on the expression level of MMP2, MMP9, and MMP16 was also assessed, as well as the impact of the altered expression on the effectiveness of the first cycle of remission-inducing therapy. To evaluate the expression of all studied genes MMP2, MMP9, and MMP16, SYBR Green-based real-time PCR method was used; the reference gene was GAPDH. For two investigated genes MMP2 and MMP16, the lower expression level was observed in patients with AML when compared to healthy people. The MMP9 gene expression level did not differ between patients with AML and healthy individuals which may indicate a different regulation of gene expression in acute myeloid leukemia. However, no correlation was observed between the genes' expression of all tested metalloproteinases and the result of cytoreductive treatment or the presence of cytogenetic changes. The obtained results show that the expression of MMP2 and MMP16 genes is reduced while the expression of MMP9 is unchanged in patients with acute myeloid leukemia. This may indicate a different regulation of the expression of these genes, and possible disruptions in gene transcription or posttranscriptional mechanisms in the MMP2 and MMP16 genes, however, do not affect the level of MMP9 expression. Obtained results in AML patients are in contrary to various types of solid tumors where increased expression is usually observed.

Doxycycline and its derivative, COL-3, decrease dyskinesia induced by l-DOPA in hemiparkinsonian rats

BACKGROUND AND PURPOSE

l-DOPA-induced dyskinesia is a debilitating effect of treating Parkinson's disease with this drug. New therapeutic approaches that prevent or attenuate this side effect are needed.

EXPERIMENTAL APPROACH

Wistar adult male rats submitted to 6-hydroxydopamine-induced unilateral medial forebrain bundle lesion were treated with l-DOPA (p.o. 20 mg·kg^-1 or s.c. 10 mg·kg^-1 ) once a day for 14 days. After this period, we tested if doxycycline (40 mg·kg^-1 , i.p.) and COL-3 (50 and 100 nmol, i.c.v.) could reverse l-DOPA-induced dyskinesia. In an additional experiment, doxycycline was administered together with l-DOPA to verify if it would prevent l-DOPA-induced dyskinesia development.

KEY RESULTS

A single injection of doxycycline or COL-3 attenuated l-DOPA-induced dyskinesia. Co-treatment with doxycycline from the first day of l-DOPA suppressed the onset of dyskinesia. The improved motor response after l-DOPA was not affected by doxycycline or COL-3. Doxycycline treatment was associated with decreased immunoreactivity of FosB, COX-2, the astroglial protein GFAP and the microglial protein OX-42, which were elevated in the basal ganglia of rats exhibiting dyskinesia. Doxycycline decreased metalloproteinase-2/-9 activity, metalloproteinase-3 expression and ROS production. Metalloproteinase-2/-9 activity and production of ROS in the basal ganglia of dyskinetic rats showed a significant correlation with the intensity of dyskinesia.

CONCLUSION AND IMPLICATIONS

The present study demonstrates the anti-dyskinetic potential of doxycycline and its analogue compound COL-3 in hemiparkinsonian rats. Given the long-established and safe clinical use of doxycycline, this study suggests that these drugs might be tested to reduce or prevent l-DOPA-induced dyskinesia in Parkinson's patients.

β-Carotene Inhibits Expression of Matrix Metalloproteinase-10 and Invasion in Helicobacter pylori-Infected Gastric Epithelial Cells

Matrix metalloproteinases (MMPs), key molecules of cancer invasion and metastasis, degrade the extracellular matrix and cell–cell adhesion molecules. MMP-10 plays a crucial role in Helicobacter pylori-induced cell-invasion. The mitogen-activated protein kinase (MAPK) signaling pathway, which activates activator protein-1 (AP-1), is known to mediate MMP expression. Infection with H. pylori, a Gram-negative bacterium, is associated with gastric cancer development. A toxic factor induced by H. pylori infection is reactive oxygen species (ROS), which activate MAPK signaling in gastric epithelial cells. Peroxisome proliferator-activated receptor γ (PPAR-γ) mediates the expression of antioxidant enzymes including catalase. β-Carotene, a red-orange pigment, exerts antioxidant and anti-inflammatory properties. We aimed to investigate whether β-carotene inhibits H. pylori-induced MMP expression and cell invasion in gastric epithelial AGS (gastric adenocarcinoma) cells. We found that H. pylori induced MMP-10 expression and increased cell invasion via the activation of MAPKs and AP-1 in gastric epithelial cells. Specific inhibitors of MAPKs suppressed H. pylori-induced MMP-10 expression, suggesting that H. pylori induces MMP-10 expression through MAPKs. β-Carotene inhibited the H. pylori-induced activation of MAPKs and AP-1, expression of MMP-10, and cell invasion. Additionally, it promoted the expression of PPAR-γ and catalase, which reduced ROS levels in H. pylori-infected cells. In conclusion, β-carotene exerts an inhibitory effect on MAPK-mediated MMP-10 expression and cell invasion by increasing PPAR-γ-mediated catalase expression and reducing ROS levels in H. pylori-infected gastric epithelial cells.

DNA or Protein Methylation-Dependent Regulation of Activator Protein-1 Function

Epigenetic regulation and modification govern the transcriptional mechanisms that promote disease initiation and progression, but can also control the oncogenic processes, cell signaling networks, immunogenicity, and immune cells involved in anti-inflammatory and anti-tumor responses. The study of epigenetic mechanisms could have important implications for the development of potential anti-inflammatory treatments and anti-cancer immunotherapies. In this review, we have described the key role of epigenetic progression: DNA methylation, histone methylation or modification, and protein methylation, with an emphasis on the activator protein-1 (AP-1) signaling pathway. Transcription factor AP-1 regulates multiple genes and is involved in diverse cellular processes, including survival, differentiation, apoptosis, and development. Here, the AP-1 regulatory mechanism by DNA, histone, or protein methylation was also reviewed. Various methyltransferases activate or suppress AP-1 activities in diverse ways. We summarize the current studies on epigenetic alterations, which regulate AP-1 signaling during inflammation, cancer, and autoimmune diseases, and discuss the epigenetic mechanisms involved in the regulation of AP-1 signaling.

To Divide or Invade: A Look Behind the Scenes of the Proliferation-Invasion Interplay in the Caenorhabditis elegans Anchor Cell

Cell invasion is defined by the capability of cells to migrate across compartment boundaries established by basement membranes (BMs). The development of complex organs involves regulated cell growth and regrouping of different cell types, which are enabled by controlled cell proliferation and cell invasion. Moreover, when a malignant tumor takes control over the body, cancer cells evolve to become invasive, allowing them to spread to distant sites and form metastases. At the core of the switch between proliferation and invasion are changes in cellular morphology driven by remodeling of the cytoskeleton. Proliferative cells utilize their actomyosin network to assemble a contractile ring during cytokinesis, while invasive cells form actin-rich protrusions, called invadopodia that allow them to breach the BMs. Studies of developmental cell invasion as well as of malignant tumors revealed that cell invasion and proliferation are two mutually exclusive states. In particular, anchor cell (AC) invasion during Caenorhabditis elegans larval development is an excellent model to study the transition from cell proliferation to cell invasion under physiological conditions. This mini-review discusses recent insights from the C. elegans AC invasion model into how G1 cell-cycle arrest is coordinated with the activation of the signaling networks required for BM breaching. Many regulators of the proliferation-invasion network are conserved between C. elegans and mammals. Therefore, the worm may provide important clues to better understand cell invasion and metastasis formation in humans.

Network Pharmacology Approach to Uncover the Mechanism Governing the Effect of Simiao Powder on Knee Osteoarthritis

Objective

To explore the molecular mechanism of Simiao powder in the treatment of knee osteoarthritis.

Methods

Based on oral bioavailability and drug-likeness, the main active components of Simiao powder were screened using the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP). GeneCard, OMIM, DisGeNET, DrugBank, PharmGkb, and the Therapeutic Target Database were used to establish target databases for knee osteoarthritis. Cytoscape software was used to construct a visual interactive network diagram of “active ingredient - action target – disease.” The STRING database was used to construct a protein interaction network and analyze related protein interaction relationships. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and Gene Ontology (GO) biological process enrichment analysis were performed on the core targets. Additionally, Discovery Studio software was used for molecular docking verification of active pharmaceutical ingredients and disease targets.

Results

Thirty-seven active components of Simiao powder were screened, including 106 common targets. The results of network analysis showed that the targets were mainly involved in regulating biological processes such as cell metabolism and apoptosis. Simiao powder components were predicted to exert their therapeutic effect on the AGE-RAGE signaling pathway in diabetic complications, IL-17 signaling pathway, TNF signaling pathway, Toll-like receptor signaling pathway, and HIF-1 signaling pathway. The molecular docking results showed that the active components of Simiao powder had a good match with the targets of IL1B, MMP9, CXCL8, MAPK8, JUN, IL6, MAPK1, EGF, VEGFA, AKT1, and PTGS2.

Conclusion

Simiao powder has multisystem, multicomponent, and multitarget characteristics in treating knee osteoarthritis. Its possible mechanism of action includes inhibiting the inflammatory response, regulating immune function, and resisting oxidative stress to control the occurrence and development of the disease. Quercetin, wogonin, kaempferol, beta-sitosterol, and other active ingredients may be the material basis for the treatment of knee osteoarthritis.

Sigesbeckia orientalis L. Extract Alleviated the Collagen Type II-Induced Arthritis Through Inhibiting Multi-Target-Mediated Synovial Hyperplasia and Inflammation

Excessive proliferation and inflammation of synovial fibroblasts accelerate and decorate the pathological process of rheumatoid arthritis (RA). Sigesbeckia orientalis L. (SO) is one of the main plant sources for Sigesbeckiae Herba (SH) which has been used traditionally in treating various forms of arthritis and rheumatic pain. However, the anti-arthritic mechanisms of SO are still not clearly understood. In this study, we investigated the therapeutic effects and the underlying mechanisms of SO against collagen type II (C II)-induced RA in rats as well as the interleukin (IL)-1β-induced human synovial SW982 and MH7A cells. For the in vivo studies, thirty-six Wistar male rats were randomly arranged to six groups based on the body weight, and then C II-induced to RA model for 15 days, followed by treatment with the 50% ethanolic extract of SO (SOE, 0.16, 0.78, and 1.56 g/kg) for 35 days. The results suggested that SOE significantly inhibited the formation of pannus (synovial hyperplasia to the articular cavity) and attenuated the cartilage damaging and bone erosion in the CIA-induced rats' hind paw joints. Moreover, SOE decreased the production of C-reactive protein (CRP) in the serum and the expression of IL-6 and IL-1β in the joint muscles, as well as recovered the decreased regulatory T lymphocytes. The results obtained from the in vitro studies showed that SOE (50, 100, and 200 µg/ml) not only inhibited the proliferation, migration, and invasion of human synovial SW982 cells but also decreased the IL-1β-induced expression of IL-6 and IL-8 both in SW982 and MH7A cells. Besides, SOE reduced the expression of COX-2, NLRP3, and MMP9, and increased the expression of MMP2 in the IL-1β-induced SW982 cells. Furthermore, SOE blocked the activation of NF-κB and reduced the phosphorylation of MAPKs and the expression of AP-1. In conclusion, SOE attenuated the C II-induced RA through inhibiting of MAPKs/NF-κB/AP-1-mediated synovial hyperplasia and inflammation.

Human Chondrocyte Activation by Toxins From Premolis semirufa, an Amazon Rainforest Moth Caterpillar: Identifying an Osteoarthritis Signature

Pararamosis is a disease that occurs due to contact with the hairs of the larval stage of the Brazilian moth Premolis semirufa. Envenomation induces osteoarticular alterations with cartilage impairment that resembles joint synovitis. Thus, the toxic venom present in the caterpillar hairs interferes with the phenotype of the cells present in the joints, resulting in inflammation and promoting tissue injury. Therefore, to address the inflammatory mechanisms triggered by envenomation, we studied the effects of P. semirufa hair extract on human chondrocytes. We have selected for the investigation, cytokines, chemokines, matrix metalloproteinases (MMPs), complement components, eicosanoids, and extracellular matrix (ECM) components related to OA and RA. In addition, for measuring protein-coding mRNAs of some molecules associated with osteoarthritis (OA) and rheumatoid arthritis (RA), reverse transcription (RT) was performed followed by quantitative real-time PCR (RT-qPCR) and we performed the RNA-sequencing (RNA-seq) analysis of the chondrocytes transcriptome. In the supernatant of cell cultures treated with the extract, we observed increased IL-6, IL-8, MCP-1, prostaglandin E2, metalloproteinases (MMP-1, MMP-2, MMP-3 and MMP-13), and complement system components (C3, C4, and C5). We noticed a significant decrease in both aggrecan and type II collagen and an increase in HMGB1 protein in chondrocytes after extract treatment. RNA-seq analysis of the chondrocyte transcriptome allowed us to identify important pathways related to the inflammatory process of the disease, such as the inflammatory response, chemotaxis of immune cells and extracellular matrix (ECM) remodeling. Thus, these results suggest that components of Premolis semirufa hair have strong inflammatory potential and are able to induce cartilage degradation and ECM remodeling, promoting a disease with an osteoarthritis signature. Modulation of the signaling pathways that were identified as being involved in this pathology may be a promising approach to develop new therapeutic strategies for the control of pararamosis and other inflammatory joint diseases.

Dermal Fibroblast CCN1 Expression in Mice Recapitulates Human Skin Dermal Aging

The aging process deleteriously alters the structure and function of dermal collagen. These alterations result in thinning, fragility, wrinkles, laxity, impaired wound healing, and a microenvironment conducive to cancer. However, the key factors responsible for these changes have not been fully elucidated, and relevant models for the study of skin aging progression are lacking. CCN1, a secreted extracellular matrix‒associated matricellular protein, is elevated in dermal fibroblasts in aged human skin. Toward constructing a mouse model to study the key factors involved in skin-aging progression, we demonstrate that transgenic mice, with selective expression of CCN1 in dermal fibroblasts (COL1A2-CCN1), display accelerated skin dermal aging. The aged phenotype in COL1A2-CCN1 mice resembles aged human dermis: the skin is wrinkled and the dermis is thin and composed of loose, disorganized, and fragmented collagen fibrils. These dermal alterations reflect reduced production of collagen due to impaired TGFβ signaling and increased expression of matrix metalloproteinases driving the induction of c-Jun/activator protein-1. Importantly, similar mechanisms drive human dermal aging. Taken together, the data demonstrate that elevated expression of CCN1 by dermal fibroblasts functions as a key mediator of dermal aging. The COL1A2-CCN1 mouse model provides a novel tool for understanding and studying the mechanisms of skin aging and age-related skin disorders.

Cerebral embolization associated with parenchymal seeding of the left atrial myxoma: Potential role of interleukin-6 and matrix metalloproteinases

Systemic embolization has been reported in up to 40% of patients with left atrial myxoma, half of them with cerebral involvement. However, development of intracerebral embolization associated with parenchymal seeding of the myxoma emboli is an extremely rare complication, with only 36 histologically diagnosed cases reported in the published literature. We describe a 69-year-old woman who arrived at the emergency service with hemiparesis associated with drug-resistant epilepsy and a medical history of resection of a left atrial myxoma 10 months previously. Cranial computed tomography revealed multiple large lesions of heterogeneous density and cystic components in the occipital lobes and posterior fossa parenchyma. Histopathological analyses after stereotactic biopsy of the occipital lesion revealed infiltrative myxoma cells with benign histological findings and uniform expression of calretinin similar to that of the primary cardiac myxoma. Additional immunohistochemical studies confirmed brain parenchymal seeding of the myxoma cells with strong expression of interleukin-6 (IL-6) and focal expression of matrix metalloproteinases-2 (MMP-2). Here, we discuss the clinicopathological features of intracerebral embolization of left atrial myxomas associated with progressive parenchymal seeding of the tumor emboli and the potential pathogenic role of IL-6 and MMPs.

Syringaresinol Inhibits UVA-Induced MMP-1 Expression by Suppression of MAPK/AP-1 Signaling in HaCaT Keratinocytes and Human Dermal Fibroblasts

Ultraviolet (UV) irradiation induces detrimental changes in human skin which result in photoaging. UV-induced intracellular changes cause degradation of extracellular matrix (ECM). UV-stimulated cleavage of collagen in ECM occurs via matrix metalloproteinases (MMPs). (±)-syringaresinol (SYR), a phytochemical which belongs to the lignan group of polyphenols, was investigated for its ability to reverse the UVA-induced changes in human HaCaT keratinocytes and dermal fibroblasts (HDFs) in vitro. Effect of SYR on UVA-induced changes was investigated by production and activation of MMPs and its transcriptional upstream effectors; mitogen-activated protein kinases (MAPKs) and pro-inflammatory mediators. Levels of expression were determined using ELISA, RT-PCR and immunoblotting. UVA irradiation stimulated the production of MMP-1 and inhibited collagen production. SYR treatment suppressed MMP-1 and enhanced collagen production in UVA-irradiated HaCaT keratinocytes and HDFs. SYR repressed the UV-induced phosphorylation of p38, ERK and JNK MAPKs in HaCaT keratinocytes while only suppressing JNK phosphorylation in HDFs. In addition, SYR was able to inhibit UVA-induced production of inflammatory cytokines; TNF-α, COX-2, IL-1β and IL-6. Moreover, SYR suppressed the activator protein-1 (AP-1), a heterodimer of phosphorylated transcription factors c-Jun and c-Fos. SYR-treatment decreased nuclear levels of activated c-Fos and c-Jun as a mechanism to inhibit UVA-induced transcriptional activities leading to MMP-1 production. In conclusion, current results demonstrated that SYR could inhibit UVA-induced upregulation of MMP-1 by suppressing MAPK/AP-1 signaling in HaCaT keratinocytes and HDFs. Therefore, SYR was suggested as a potential compound with antiphotoaging properties against UVA-induced skin aging.

Anti‑metastatic effects of arctigenin are regulated by MAPK/AP‑1 signaling in 4T‑1 mouse breast cancer cells

Arctigenin is a natural lignan that is found in burdock with anti‑viral, ‑oxidative, ‑inflammatory and anti‑tumor activities. In the current study, the effect of arctigenin on metastatic potential was examined in 4T‑1 mouse triple‑negative breast cancer cells. The results indicated that arctigenin inhibited cell motility and invasiveness, which was determined using wound healing and transwell invasion assays. Arctigenin suppressed matrix metalloprotease‑9 (MMP‑9) activity via gelatin zymography, and protein expression of cyclooxygenase‑2 (COX‑2) and MMP‑3. Furthermore, arctigenin attenuated the mRNA expression of metastatic factors, including MMP‑9, MMP‑3 and COX‑2. Based on these results, the effect of arctigenin on the mitogen‑activated protein kinase (MAPK)/activating protein‑1 (AP‑1) signaling pathway was assessed in an attempt to identify the regulatory mechanism responsible for its anti‑metastatic effects. Arctigenin was demonstrated to inhibit the phosphorylation of extracellular signal‑regulated protein kinase (ERK) and c‑Jun N‑terminal kinase (JNK), and the nuclear translocations of the AP‑1 subunits, c‑Jun and c‑Fos. In summary, the present study demonstrated that in 4T‑1 mouse triple‑negative breast cancer cells the anti‑metastatic effect of arctigenin is mediated by the inhibition of MMP‑9 activity and by the inhibition of the metastasis‑enhancing factors MMP‑9, MMP‑3 and COX‑2, due to the suppression of the MAPK/AP‑1 signaling pathway. The results of the current study demonstrated that arctigenin exhibits a potential for preventing cell migration and invasion in triple negative breast cancer.

LMO7 Is a Negative Feedback Regulator of Transforming Growth Factor β Signaling and Fibrosis

BACKGROUND

Vascular smooth muscle cells (SMCs) synthesize extracellular matrix (ECM) that contributes to tissue remodeling after revascularization interventions. The cytokine transforming growth factor β (TGF-β) is induced on tissue injury and regulates tissue remodeling and wound healing, but dysregulated signaling results in excess ECM deposition and fibrosis. The LIM (Lin11, Isl-1 & Mec-3) domain protein LIM domain only 7 (LMO7) is a TGF-β1 target gene in hepatoma cells, but its role in vascular physiology and fibrosis is unknown.

METHODS

We use carotid ligation and femoral artery denudation models in mice with global or inducible smooth muscle-specific deletion of LMO7, and knockout, knockdown, overexpression, and mutagenesis approaches in mouse and human SMC, and human arteriovenous fistula and cardiac allograft vasculopathy samples to assess the role of LMO7 in neointima and fibrosis.

RESULTS

We demonstrate that LMO7 is induced postinjury and by TGF-β in SMC in vitro. Global or SMC-specific LMO7 deletion enhanced neointimal formation, TGF-β signaling, ECM deposition, and proliferation in vascular injury models. LMO7 loss of function in human and mouse SMC enhanced ECM protein expression at baseline and after TGF-β treatment. TGF-β neutralization or receptor antagonism prevented the exacerbated neointimal formation and ECM synthesis conferred by loss of LMO7. Notably, loss of LMO7 coordinately amplified TGF-β signaling by inducing expression of Tgfb1 mRNA, TGF-β protein, αv and β3 integrins that promote activation of latent TGF-β, and downstream effectors SMAD3 phosphorylation and connective tissue growth factor. Mechanistically, the LMO7 LIM domain interacts with activator protein 1 transcription factor subunits c-FOS and c-JUN and promotes their ubiquitination and degradation, disrupting activator protein 1-dependent TGF-β autoinduction. Importantly, preliminary studies suggest that LMO7 is upregulated in human intimal hyperplastic arteriovenous fistula and cardiac allograft vasculopathy samples, and inversely correlates with SMAD3 phosphorylation in cardiac allograft vasculopathy.

CONCLUSIONS

LMO7 is induced by TGF-β and serves to limit vascular fibrotic responses through negative feedback regulation of the TGF-β pathway. This mechanism has important implications for intimal hyperplasia, wound healing, and fibrotic diseases.

Increasing the low lipid phosphate phosphatase 1 activity in breast cancer cells decreases transcription by AP-1 and expressions of matrix metalloproteinases and cyclin D1/D3

Metastasis is the leading cause of mortality in breast cancer patients and lysophosphatidate (LPA) signaling promotes this process. LPA signaling is attenuated by lipid phosphate phosphatase-1 (LPP1) whose activity is decreased in cancers. Consequently, increasing LPP1 levels suppresses breast tumor growth and metastasis. This study shows that increasing LPP1 in breast cancer cells decreases transcription through cFos and cJun. This decreases production of cyclin D1/D3 and matrix metalloproteinases (MMPs), which provides new insights into the role of LPP1 in controlling tumor growth and metastasis. Methods: Invasiveness was determined by a Matrigel invasion assay. MMP expression was measured by qPCR, multiplex LASER bead technology and gelatin zymography. Levels of cJUN, cFOS, FRA1, cyclin D1, and cyclin D3 were determined by qPCR and western blotting. Collagen was determined by Picro-Sirius Red staining. Results: Increasing LPP1 expression inhibited invasion of MDA-MB-231 breast cancer cells through Matrigel. This was accompanied by decreases in expression of MMP-1, -3, -7, -9, -10, -12 and -13, which are transcriptionally regulated by the AP-1 complex. Increasing LPP1 attenuated the induction of mRNA of MMP-1, -3, cFOS, and cJUN by EGF or TNFα, but increased FRA1. LPP1 expression also decreased the induction of protein levels for cFOS and cJUN in nuclei and cytoplasmic fractions by EGF and TNFα. Protein levels of cyclin D1 and D3 were also decreased by LPP1. Although FRA1 in total cell lysates or cytoplasm was increased by LPP1, nuclear FRA1 was not affected. LPP1-induced decreases in MMPs in mouse tumors created with MDA-MB-231 cells were accompanied by increased collagen in the tumors and fewer lung metastases. Knockdown of LPP1 in MDA-MB-231 cells increased the protein levels of MMP-1 and -3. Human breast tumors also have lower levels of LPP1 and higher levels of cJUN, cFOS, MMP-1, -7, -8, -9, -12, -13, cyclin D1, and cyclin D3 relative to normal breast tissue. Conclusion: This study demonstrated that the low LPP1 expression in breast cancer cells is associated with high levels of cyclin D1/D3 and MMPs as a result of increased transcription by cFOS and cJUN. Increasing LPP1 expression provides a novel approach for decreasing transcription through AP-1, which could provide a strategy for decreasing tumor growth and metastasis.

Derepression of matrix metalloproteinase gene transcription and an emphysema-like phenotype in transcription factor Zbtb7c knockout mouse lungs

Dysregulated matrix metalloproteinase (MMP) gene expression is a major cause of the degradation of lung tissue that is integral to emphysema pathogenesis. Cigarette smoking (CS) increases MMP gene expression, a major contributor to emphysema development. We previously reported that Zbtb7c is a transcriptional repressor of several Mmp genes (Mmps-8, -10, -13, and -16). Here, we show that Zbtb7c knockout mice have mild emphysema-like phenotypes, including alveolar wall destruction, enlarged alveoli, and upregulated Mmp genes. Alveolar size and Mmp gene expression in Zbtb7c^-/- mouse lungs are increased more severely upon exposure to CS, compared to those of Zbtb7c^+/+ mouse lungs. These observations suggest that Zbtb7c degradation or absence may contribute to the pathogenesis of emphysema.

Skullcapflavone II Inhibits Degradation of Type I Collagen by Suppressing MMP-1 Transcription in Human Skin Fibroblasts

Skullcapflavone II is a flavonoid derived from the root of Scutellaria baicalensis, a herbal medicine used for anti-inflammatory and anti-cancer therapies. We analyzed the effect of skullcapflavone II on the expression of matrix metalloproteinase-1 (MMP-1) and integrity of type I collagen in foreskin fibroblasts. Skullcapflavone II did not affect the secretion of type I collagen but reduced the secretion of MMP-1 in a dose- and time-dependent manner. Real-time reverse transcription-PCR and reporter gene assays showed that skullcapflavone II reduced MMP-1 expression at the transcriptional level. Skullcapflavone II inhibited the serum-induced activation of the extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) signaling pathways required for MMP-1 transactivation. Skullcapflavone II also reduced tumor necrosis factor (TNF)-α-induced nuclear factor kappa light chain enhancer of activated B cells (NF-κB) activation and subsequent MMP-1 expression. In three-dimensional culture of fibroblasts, skullcapflavone II down-regulated TNF-α-induced MMP-1 secretion and reduced breakdown of type I collagen. These results indicate that skullcapflavone II is a novel biomolecule that down-regulates MMP-1 expression in foreskin fibroblasts and therefore could be useful in therapies for maintaining the integrity of extracellular matrix.

Recent advances in understanding the regulation of metalloproteinases

Metalloproteinases remain important players in arthritic disease, in part because members of this large enzymatic family, namely matrix metalloproteinase-1 (MMP-1) and MMP-13, are responsible for the irreversible degradation of articular cartilage collagen. Although direct inhibition of MMPs fell out of vogue with the initial clinical disappointment of the first generation of compounds, interest in other mechanisms that control these important enzymes has always been maintained. Since these enzymes are critically important for tissue homeostasis, their expression and activity are tightly regulated at many levels, not just by direct inhibition by their endogenous inhibitors the tissue inhibitors of metalloproteinases (TIMPs). Focussing on MMP-13, we discuss recent work that highlights new discoveries in the transcriptional regulation of this enzyme, from defined promoter functional analysis to how more global technologies can provide insight into the enzyme’s regulation, especially by epigenetic mechanisms, including non-coding RNAs. In terms of protein regulation, we highlight recent findings into enzymatic cascades involved in MMP-13 regulation and activation. Importantly, we highlight a series of recent studies that describe how MMP-13 activity, and in fact that of other metalloproteinases, is in part controlled by receptor-mediated endocytosis. Together, these new discoveries provide a plethora of novel regulatory mechanisms, besides direct inhibition, which with renewed vigour could provide further therapeutic opportunities for regulating the activity of this class of important enzymes.

Regulation of MMP 2 and MMP 9 expressions modulated by AP-1 (c-jun) in wound healing: improving role of Lucilia sericata in diabetic rats

AIMS

Lucilia sericata larvae have been successfully used on healing of wounds in the diabetics. However, the involvement of the extraction/secretion (ES) products of larvae in the treatment of diabetic wounds is still unknown. Activator protein-1 (AP-1) transcription, composed of c-jun and c-Fos proteins, has been shown to be the principal regulator of multiple MMP transcriptions under a variety of conditions, also in diabetic wounds. Specifically, MMP-2 and MMP-9's transcriptions are known to be modulated by AP-1. c-jun has been demonstrated to be a repressor of p53 in immortalized fibroblasts. The aim of the present study is to investigate the effects of L. sericata ES on the expression of AP-1 (c-jun), p53, MMP-2, and MMP-9 in wound biopsies dissected from streptozotocin induced diabetic rats.

METHODS

The expression levels of MMP-2, MMP-9, c-jun and p53 in dermal tissues were determined at days 0, 3, 7 and 14 after wounding, using immunohistochemical analysis and quantitative real-time PCR.

RESULTS

The treatment with ES significantly decreased through inflammation-based induction of MMP-2 and MMP-9 expression levels in the wounds of diabetic groups, compared to control groups at the third day of wound healing. At the 14th day, there were dramatic decreases in expression of c-jun, MMP-9, and p53 in ES-treated groups, compared to the diabetic group (P < 0.001, P < 0.05 and P < 0.01, respectively).

CONCLUSION

ES products of L. sericata may enhance the process of wound healing in phases of inflammation, proliferation, and re-epithelization, essentially via regulating c-jun expression and modulating MMP-2 and MMP-9 expressions.

Cytokine-induced cysteine- serine-rich nuclear protein-1 (CSRNP1) selectively contributes to MMP1 expression in human chondrocytes

Irreversible cartilage collagen breakdown by the collagenolytic matrix metalloproteinases (MMPs)-1 and MMP-13 represents a key event in pathologies associated with tissue destruction such as arthritis. Inflammation is closely associated with such pathology and occurs in both rheumatoid and osteoarthritis making it highly relevant to the prevailing tissue damage that characterises these diseases. The inflammation-induced activating protein-1 (AP-1) transcription factor is an important regulator of both MMP1 and MMP13 genes with interplay between signalling pathways contributing to their expression. Here, we have examined the regulation of MMP1 expression, and using in vivo chromatin immunoprecipitation analyses we have demonstrated that cFos bound to the AP-1 cis element within the proximal MMP1 promoter only when the gene was transcriptionally silent as previously observed for MMP13. Subsequent small interfering RNA-mediated silencing confirmed however, that cFos significantly contributes to MMP1 expression. In contrast, silencing of ATF3 (a prime MMP13 modulator) did not affect MMP1 expression whilst silencing of the Wnt-associated regulator cysteine- serine-rich nuclear protein-1 (CSRNP1) resulted in substantial repression of MMP1 but not MMP13. Furthermore, following an early transient peak in expression of CSRNP1 at the mRNA and protein levels similar to that seen for cFOS, CSRNP1 expression subsequently persisted unlike cFOS. Finally, DNA binding assays indicated that the binding of CSRNP1 to the AP-1 consensus-like sequences within the proximal promoter regions of MMP1 and MMP13 was preferentially selective for MMP1 whilst activating transcription factor 3 (ATF3) binding was exclusive to MMP13. These data further extend our understanding of the previously reported differential regulation of these MMP genes, and strongly indicate that although cFos modulates the expression of MMP1/13, downstream factors such as CSRNP1 and ATF3 ultimately serve as transcriptional regulators in the context of an inflammatory stimulus for these potent collagenolytic MMPs.

Protein kinase D3 modulates MMP1 and MMP13 expression in human chondrocytes

Many catabolic stimuli, including interleukin-1 (IL-1) in combination with oncostatin M (OSM), promote cartilage breakdown via the induction of collagen-degrading collagenases such as matrix metalloproteinase 1 (MMP1) and MMP13 in human articular chondrocytes. Indeed, joint diseases with an inflammatory component are characterised by excessive extracellular matrix (ECM) catabolism. Importantly, protein kinase C (PKC) signalling has a primary role in cytokine-induced MMP1/13 expression, and is known to regulate cellular functions associated with pathologies involving ECM remodelling. At present, substrates downstream of PKC remain undefined. Herein, we show that both IL-1- and OSM-induced phosphorylation of protein kinase D (PKD) in human chondrocytes is strongly associated with signalling via the atypical PKCι isoform. Consequently, inhibiting PKD activation with a pan-PKD inhibitor significantly reduced the expression of MMP1/13. Specific gene silencing of the PKD isoforms revealed that only PKD3 (PRKD3) depletion mirrored the observed MMP repression, indicative of the pharmacological inhibitor specifically affecting only this isoform. PRKD3 silencing was also shown to reduce serine phosphorylation of signal transducer and activator of transcription 3 (STAT3) as well as phosphorylation of all three mitogen-activated protein kinase groups. This altered signalling following PRKD3 silencing led to a significant reduction in the expression of the activator protein-1 (AP-1) genes FOS and JUN, critical for the induction of many MMPs including MMP1/13. Furthermore, the AP-1 factor activating transcription factor 3 (ATF3) was also reduced concomitant with the observed reduction in MMP13 expression. Taken together, we highlight an important role for PKD3 in the pro-inflammatory signalling that promotes cartilage destruction.

Transcription Factor SOX5 Promotes the Migration and Invasion of Fibroblast-Like Synoviocytes in Part by Regulating MMP-9 Expression in Collagen-Induced Arthritis

Objectives

Fibroblast-like synoviocytes (FLS) exhibit a unique aggressive phenotype in rheumatoid arthritis (RA). Increased FLS migration and subsequent invasion of the extracellular matrix are essential to joint destruction in RA. Our previous research reported that transcription factor SOX5 was highly expressed in RA-FLS. Here, the effects of SOX5 in RA-FLS migration and invasion will be investigated.

Methods

The migration and invasion of RA-FLS were evaluated using a transwell chamber assay. The expression of several potential SOX5-targeted genes, including matrix metalloproteinases (MMP-1, 2, 3 and 9), chemokines (CCL4, CCL2, CCR5 and CCR2), and pro-inflammatory cytokines (TNF-α and IL-6), were examined in RA-FLS using SOX5 gain- and loss-of-function study. The molecular mechanisms of SOX5-mediated MMP-9 expressions were assayed by luciferase reporter gene and chromatin immunoprecipitation (ChIP) studies. The in vivo effect of SOX5 on FLS migration and invasion was examined using collagen-induced arthritis (CIA) in DBA/1J mice.

Results

Knockdown SOX5 decreased lamellipodium formation, migration, and invasion of RA-FLS. The expression of MMP-9 was the only gene tested to be concomitantly affected by silencing or overexpressing SOX5. ChIP assay revealed that SOX5 was bound to the MMP-9 promoter in RA-FLS. The overexpression of SOX5 markedly enhanced the MMP-9 promoter activity, and specific deletion of a putative SOX5-binding site in MMP-9 promoter diminished this promoter-driven transcription in FLS. Locally knocked down SOX5 inhibited MMP-9 expression in the joint tissue and reduced pannus migration and invasion into the cartilage in CIA mice.

Conclusion

SOX5 plays a novel role in mediating migration and invasion of FLS in part by regulating MMP-9 expression in RA.

The Protein Extract of Chlorella minutissima Inhibits The Expression of MMP-1, MMP-2 and MMP-9 in Cancer Cells through Upregulation of TIMP-3 and Down Regulation of c-Jun

Objective

Considering the bioactivities exhibited by microalgae, the effect of protein extract of Chlorella minutissimma (CP extract) was investigated on the expression of human matrix metalloproteinases-1 (MMP-1) in the breast cancer cell line MDA-MB231, and that of MMP-2 and -9 in hepatocellular cancer cell line HepG2 at different expression levels. The study aimed identification and analysis of inhibitory activity of microalgal components extracted from Chlorella minutissima against human MMPs.

Materials and Methods

In this experimental study, we analysed the effect of Chlorella extracts on MMP-1, -2, and -9 expression at various levels. Gelatin zymography was performed to study the inhibitory effect of Chlorella exracts on human gelatinases at the activity level, followed by western blotting to analyse the expression of all three MMPs at the protein level. The similar effect at the mRNA level along with the probable mechanism underlying inhibition of MMPs was assessed using real-time polymerase chain reaction (PCR).

Results

The results reveal that the treatment with CP extract decreased the mRNA expression of MMP-1, MMP-2, and MMP-9 by 0.26-, 0.29-, and 0.40-fold, respectively, at 20 μg/ml concentration as well as inhibited the activity of MMP-2 and MMP-9 by 37.56 and 42.64%, respectively, at 15 μg/ml concentration. Additionally, upregulated mRNA expression of tissue inhibitor of metalloproteinases-3 (TIMP-3) by 1.68-fold was seen in HepG2 cells at 20 μg/ml concentration treatment group. However, CP extract did not induce any change in the mRNA expression of the TIMP-1, -2 and -4 in HepG2 and TIMP-1, -2, -3 and -4 in MDA-MB231 cells. Activator protein-1 (AP-1)-dependent c-Jun-mediated transcriptional regulation of MMP-1, -2, and -9 was also studied to elucidate the appropriate mechanism involved in the inhibition of MMPs.

Conclusion

The CP extract successfully inhibited MMP-1, -2, and -9 at different expression levels through TIMP-3 upregulation and c-Jun downregulation.

Nobiletin inhibits human osteosarcoma cells metastasis by blocking ERK and JNK-mediated MMPs expression

Nobiletin, a polymethoxyflavone, has a few pharmacological activities, including anti-inflammation and anti-cancer effects. However, its effect on human osteosarcoma progression remains uninvestigated. Therefore, we examined the effectiveness of nobiletin against cellular metastasis of human osteosarcoma and the underlying mechanisms. Nobiletin, up to 100 μM without cytotoxicity, significantly decreased motility, migration and invasion as well as enzymatic activities, protein levels and mRNA expressions of matrix metalloproteinase (MMP)-2 and MMP-9 in U2OS and HOS cells. In addition to inhibition of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK), the inhibitory effect of nobiletin on the DNA-binding activity of the transcription factor nuclear factor-kappa B (NF-κB), cAMP response element-binding protein (CREB), and specificity protein 1 (SP-1) in U2OS and HOS cells. Co-treatment with ERK and JNK inhibitors and nobiletin further reduced U2OS cells migration and invasion. These results indicated that nobiletin inhibits human osteosarcoma U2OS and HOS cells motility, migration and invasion by down-regulating MMP-2 and MMP-9 expressions via ERK and JNK pathways and through the inactivation of downstream NF-κB, CREB, and SP-1. Nobiletin has the potential to serve as an anti-metastatic agent for treating osteosarcoma.