Taiwanin C elicits apoptosis in arecoline and 4-nitroquinoline-1-oxide-induced oral squamous cell carcinoma cells and hinders proliferation via epidermal growth factor receptor/PI3K suppression.

Oral Squamous Cell Carcinoma (OSSC) is a major life-threatening disease with high incidence in the Southeast Asian countries. Chronic exposure to arecoline causes genetic changes in the epithelial cells of the oral mucosa, induces proliferation through activation of the EGF receptor and promotes downstream COX-2 expression. Taiwanin C, a podophyllotoxin derived from Taiwania cryptomerioides Hayata is known to inhibit COX activity and to hinder PGE2 production in macrophages. In this study a tumor cell line T28 and a non-tumor cell line N28 derived from mice OSCC models were used to study the effect of Taiwanin C on PGE2 associated COX-2 expression and cell cycle regulators. Taiwanin C activated p21 protein expression, down-regulated cell cycle regulatory proteins, elevated apoptosis and down-regulated p-PI3K/p-Akt survival mechanism in T28 oral cancer cells. Our results therefore emphasize the therapeutic potential of Taiwanin C against arecoline-induced oral cancer.

Haloperidol Abrogates Matrix Metalloproteinase-9 Expression by Inhibition of NF-κB Activation in Stimulated Human Monocytic Cells.

Much evidence has indicated that matrix metalloproteinases (MMPs) participate in the progression of neuroinflammatory disorders. The present study was undertaken to investigate the inhibitory effect and mechanism of the antipsychotic haloperidol on MMP activation in the stimulated THP-1 monocytic cells. Haloperidol exerted a strong inhibition on tumor necrosis factor- (TNF-) α-induced MMP-9 gelatinolysis of THP-1 cells. A concentration-dependent inhibitory effect of haloperidol was observed in TNF-α-induced protein and mRNA expression of MMP-9. On the other hand, haloperidol slightly affected cell viability and tissue inhibition of metalloproteinase-1 levels. It significantly inhibited the degradation of inhibitor-κB-α (IκBα) in activated cells. Moreover, it suppressed activated nuclear factor-κB (NF-κB) detected by a mobility shift assay, NF-κB reporter gene, and chromatin immunoprecipitation analyses. Consistent with NF-κB inhibition, haloperidol exerted a strong inhibition of lipopolysaccharide- (LPS-) induced MMP-9 gelatinolysis but not of transforming growth factor-ß1-induced MMP-2. In in vivo studies, administration of haloperidol significantly attenuated LPS-induced intracerebral MMP-9 activation of the brain homogenate and the in situ in C57BL/6 mice. In conclusion, the selective anti-MMP-9 activation of haloperidol could possibly involve the inhibition of the NF-κB signal pathway. Hence, it was found that haloperidol treatment may represent a bystander of anti-MMP actions for its conventional psychotherapy.

Cryptotanshinone (Dsh-003) from Salvia miltiorrhiza Bunge inhibits prostaglandin E2-induced survival and invasion effects in HA22T hepatocellular carcinoma cells.

Human hepatocellular carcinoma (HCC) is currently the second most common cancer and one of the leading causes of cancer-related mortality in Taiwan. Previous reports show that the expression of (E-type prostaglandin 2) EP2 and (E-type prostaglandin 4) EP4 are elevated in HCC and further demonstrate that Prostaglandin E2 (PGE2) induces HA22T cell proliferation and metastasis through EP2 and EP4 receptor. Danshen (root of Salvia miltiorrhiza Bunge) is a very important and popular traditional Chinese herbal medicine which is widely and successfully used against breast cancer, leukemia, pancreatic cancer, and head and neck squamous carcinoma cells. In this study, we used Cryptotansinone (Dsh-003) (MW 269.14) from Danshen to investigate their effect and corresponding mechanism of action in PGE2-treated HA22T cells. Dsh-003 inhibited HA22T cell viability and further induced cell apoptosis in PGE2-treated HA22T cells. Furthermore, Dsh-003 inhibited EP2, EP4, and their downstream effector such as p-PI3K and p-Akt expression in HA22T hepatocellular carcinoma cells. We also observed that Dsh-003 blocked PGE2-induced cell migration by down-regulating PGE2-induced ß-catenin expression and by up-regulating E-cadherin and GSK3-ß expression. All these findings suggest that Dsh-003 inhibit human HCC cell lines and could potentially be used as a novel drug for HCC treatment.

The Novel HDAC8 Inhibitor WK2-16 Attenuates Lipopolysaccharide-Activated Matrix Metalloproteinase-9 Expression in Human Monocytic Cells and Improves Hypercytokinemia In Vivo.

Dysregulated human monocytes/macrophages can synthesize and secrete matrix metalloproteinases (MMPs), which play important roles in the progression of sepsis. In this study, we investigated the effects and mechanism of a novel histone deacetylase (HDAC8) inhibitor, (E)-N-hydroxy-4-methoxy-2-(biphenyl-4-yl)cinnamide (WK2-16), on MMP-9 production and activation in stimulated human monocytic THP-1 cells. Our results demonstrated that the acetylation level of structural maintenance of chromosomes 3 (SMC3) was up-regulated by WK2-16 in THP-1 cells. Consistently, an in vitro enzyme study demonstrated that WK2-16 selectively inhibited HDAC8 activity. Moreover, the WK2-16 concentration dependently suppressed MMP-9-mediated gelatinolysis induced by tumor necrosis factor-α (TNF-α) or lipopolysaccharide (LPS). Additionally, WK2-16 significantly inhibited both MMP-9 protein and mRNA expression without cellular toxicity. Nevertheless, WK2-16 suppressed the extracellular levels of interleukin (IL)-6 from LPS-stimulated THP-1 cells. For the signaling studies, WK2-16 had no effect on LPS/TLR4 downstream signaling pathways, such as the NF-κB and ERK/JNK/P38 MAPK pathways. On the other hand, WK2-16 enhanced the recruitment of acetylated Yin Yang 1 (YY1) with HDAC1. Finally, in vivo studies indicated that WK2-16 could reduce the serum levels of TNF-α and IL-6 in endotoxemic mice. These results suggested that HDAC8 inhibition might provide a novel therapeutic strategy of hypercytokinemia in sepsis.

Comparison between HPSEC-OCD and F-EEMs for assessing DBPs formation in water.

In this study, natural organic matter (NOM) in source water, as well as the treated water after coagulation with or without potassium permanganate (KMnO4) preoxidation, was characterized by using high performance size exclusion chromatography with organic carbon detector (HPSEC-OCD) and fluorescence excitation emission matrices (F-EEMs) with parallel factor (PARAFAC) analysis. Bulk parameters, such as dissolved organic carbon (DOC) and ultraviolet light absorbance at 254 nm (UV254), were also analyzed. The results show that KMnO4 preoxidation caused the breakdown of high molecular weight (MW) organics into low MW organics. All organics, whether those that existed in the source water or those generated by KMnO4 preoxidation, could be partly removed by coagulation. Combining the derived organic fractions obtained from HPSEC-OCD with peak-fitting and from F-EEMs with PARAFAC on the same sample, humic substances have been specified as the main organic composition. Further, the predictive models for trihalomethanes formation potential (THMFP) and haloacetic acids formation potential (HAAFP) based on organic fractions from HPSEC-OCD have higher accuracy than those based on the components from PARAFAC modeling. These models provide useful tools to specify the organic fractions from HPSEC-OCD and F-EEMs that constitute active precursors towards trihalomethanes (THMs) or haloacetic acids (HAAs) formation in water. Further, by knowing the major organic precursors, it would facilitate choosing the appropriate water treatment process for disinfection by-products (DBPs) control.

Histone deacetylase inhibitor m-carboxycinnamic acid bis-hydroxamide attenuates plasminogen activator inhibitor-1 expression in human pleural mesothelial cells.

Plasminogen activator inhibitor-1 (PAI-1), primarily up-regulated by transforming growth factor (TGF)-ß, is essential in the development of fibrosis. Histone deacetylase (HDAC) was shown to modulate gene expression and fibrogenesis in various tissues. However, the implications of HDAC in terms of PAI-1 expression and pleural fibrosis remain unclear. In this study, we examined the effects of m-carboxycinnamic acid bis-hydroxamide (CBHA), a hybrid-polar HDAC inhibitor, on the TGF-ß1-induced expression of PAI-1 in a human pleural mesothelial cell line (MeT-5A). MeT-5A cells were treated with TGF-ß1 in the presence or absence of CBHA. We assayed the expression and stability of PAI-1 mRNA and protein, PAI-1 promoter activity, the activation of Smad signaling, the protein-protein interactions of Smads with transcriptional cofactors Sp1 and coactivator p300, and the expression of the mRNA-stabilizing protein nucleolin. The results indicate that CBHA significantly inhibited TGF-ß1-induced PAI-1 mRNA and protein expression, and attenuated PAI-1 promoter activity in MeT-5A cells. CBHA abrogated TGF-ß1-induced Smad4 nuclear translocation, but not Smad2/3 activation. Furthermore, the association of Smad4 with p300, but not with Sp1, was disrupted by CBHA. Alternatively, CBHA suppressed TGF-ß1-induced nucleolin expression, and thereby destabilized PAI-1 mRNA and decreased PAI-1 protein concentrations. These findings suggest that the inhibition of HDAC activity by CBHA may attenuate PAI-1 expression through the modulation of cellular signaling at multiple levels. Given the down-regulating effect of CBHA on PAI-1 expression, HDAC inhibitors should be tested further in animal models as potential therapeutic agents for pleural fibrosis.

Hypertonicity-enhanced TNF-α release from activated human monocytic THP-1 cells requires ERK activation.

BACKGROUND: Hypertonic stress enhances tumor necrosis factor (TNF)-α expression in activated monocytes. However, the underlying mechanism is unknown. The produced TNF-α is primarily cleaved and released by TNF-α-converting enzyme (TACE), and the surface expression of TACE is down-regulated by endocytosis. As hypertonicity inhibits endocytosis, we evaluated the mechanism of hypertonicity-induced TNF-α release from activated human monocytic THP-1 cells. METHODS: THP-1 cells were stimulated with lipopolysaccharide (LPS) or phorbol 12-myristate 13-acetate (PMA) in the presence or absence of hypertonic agents (150 mM sucrose or 150-300 mM NaCl). The amount of TNF-α mRNA and protein, surface expression of TACE and activation of signaling pathways (mitogen-activated protein kinase, Akt and NF-κB) were assayed. RESULTS: Hypertonic sucrose and NaCl significantly enhanced TNF-α release from THP-1 cells upon LPS or PMA stimulation. Hypertonic sucrose and other endocytosis inhibitors increased surface expression of TACE, but their effects on TNF-α release were inconsistent. This enhancement effect by hypertonicity was not attenuated by inhibition of TACE or IκB kinase, but it was blocked by cycloheximide and a MAP/ERK kinase inhibitor. The LPS- or PMA-induced TNF-α mRNA expression was not increased; rather, it was inhibited by hypertonicity. ERK1/2 was re-activated after sucrose treatment in LPS-stimulated THP-1 cells. CONCLUSIONS: Hypertonicity-enhanced TNF-α protein synthesis from LPS- or PMA-activated THP-1 cells requires ERK activation and may proceed without TACE. GENERAL SIGNIFICANCE: A vast amount of TNF-α production was regulated by a crucial post-transcriptional manner in activated human monocytic leukemia cells, and it may possibly be contributed to the cachexia condition.

Dynasore, a dynamin inhibitor, induces PAI-1 expression in MeT-5A human pleural mesothelial cells.

Plasminogen activator inhibitor-1 (PAI-1) is a primary regulator of plasminogen activation that plays an essential role in regulating the physiological thrombotic/fibrinogenic balance. The elevation of PAI-1 expression by human pleural mesothelial cells has been reported to contribute to pleural fibrosis and pleurodesis. In this study, we examined the effects on PAI-1 expression of dynasore, a cell-permeable inhibitor of dynamin, and its mechanisms in a human pleural mesothelial cell line (MeT-5A). The results indicated that dynasore enhanced transforming growth factor (TGF)-beta(1)- and TNF-alpha-induced PAI-1 protein expression in a concentration-dependent manner. Furthermore, dynasore significantly up-regulated PAI-1 protein and its messenger RNA expressions. Interestingly, Smad2/3 activation was induced by TGF-beta(1) but not by dynasore. Among signaling inhibitors, a c-Jun NH(2)-terminal kinase (JNK) inhibitor (SP600125) markedly attenuated dynasore-stimulated PAI-1 protein production. Consistently, dynasore strongly increased JNK phosphorylation. On the other hand, there was no enhancement effect by dynasore on TGF-beta(1)-induced matrix metalloproteinase-2 activation. These findings suggest that dynasore may stimulate PAI-1 protein expression and enhance TGF-beta(1) activity through activation of JNK-mediated signaling in human pleural mesothelial cells. Given the profibrotic effect of dynasore, further in vivo studies may be conducted to evaluate its potential as a pleurodesing agent.

Mycobacterium tuberculosis Upregulates TNF-α Expression via TLR2/ERK Signaling and Induces MMP-1 and MMP-9 Production in Human Pleural Mesothelial Cells.

BACKGROUND: Tumor necrosis factor (TNF)-α and matrix metalloproteinases (MMPs) are elevated in pleural fluids of tuberculous pleuritis (TBP) where pleural mesothelial cells (PMCs) conduct the first-line defense against Mycobacterium tuberculosis (MTB). However, the clinical implication of TNF-α and MMPs in TBP and the response of PMCs to MTB infection remain unclear. METHODS: We measured pleural fluid levels of TNF-α and MMPs in patients with TBP (n = 18) or heart failure (n = 18) as controls. Radiological scores for initial effusion amount and residual pleural fibrosis at 6-month follow-up were assessed. In vitro human PMC experiments were performed to assess the effect of heat-killed M. tuberculosis H37Ra (MTBRa) on the expression of TNF-α and MMPs. RESULTS: As compared with controls, the effusion levels of TNF-α, MMP-1 and MMP-9 were significantly higher and correlated positively with initial effusion amount in patients with TBP, while TNF-α and MMP-1, but not MMP-9, were positively associated with residual pleural fibrosis of TBP. Moreover, effusion levels of TNF-α had positive correlation with those of MMP-1 and MMP-9 in TBP. In cultured PMCs, MTBRa enhanced TLR2 and TLR4 expression, activated ERK signaling, and upregulated TNF-α mRNA and protein expression. Furthermore, knockdown of TLR2, but not TLR4, significantly inhibited ERK phosphorylation and TNF-α expression. Additionally, both MTBRa and TNF-α markedly induced MMP-1 and MMP-9 synthesis in human PMCs, and TNF-α neutralization substantially reduced the production of MMP-1, but not MMP-9, in response to MTBRa stimulation. CONCLUSION: MTBRa activates TLR2/ERK signalings to induce TNF-α and elicit MMP-1 and MMP-9 in human PMCs, which are associated with effusion volume and pleural fibrosis and may contribute to pathogenesis of TBP. Further investigation of manipulation of TNF-α and MMP expression in pleural mesothelium may provide new insights into the mechanisms and rational treatment strategies for TBP.

Suppression of matrix metalloproteinase-9 expression by andrographolide in human monocytic THP-1 cells via inhibition of NF-κB activation.

There is much evidence indicating that human leukemic cells and monocytes/macrophages synthesize, and secrete, several matrix metalloproteinases (MMPs), and participate in the degradation of extracellular matrix components in tissue lesions. In this study, we investigated the effects and mechanisms of andrographolide, extracted from the herb Andrographis paniculata, on human monocytic MMPs expression and activation. Andrographolide (1-50 µM) exhibited concentration-dependent inhibition of MMP-9 activation, induced by either tumor necrosis factor-α (TNF-α), or lipopolysaccharide (LPS), in THP-1cells. In addition, andrographolide did not present an inhibitory effect on MMP-9 enzymatic activity at a concentration of 50 µM. By contrast, enzyme-linked immunosorbent assay (ELISA) showed that andrographolide partially affect TIMP-1 levels. Western blot analysis showed that both TNF-α, and LPS stimulators attenuated MMP-9 protein expression in a concentration-dependent manner. Using reverse transcription polymerase chain reaction (RT-PCR), we found that andrographolide suppressed expression of MMP-9 messenger RNA. Furthermore, we also found that andrographolide could significantly inhibit the degradation of inhibitor-κB-α (IκB-α) induced by TNF-α. We used electrophoretic mobility shift assay and reporter gene detection to show that andrographolide also markedly inhibited NF-κB signaling, anti-translocation and anti-activation. In conclusion, we demonstrate that andrographolide attenuates MMP-9 expression, and its main mechanism might involve the NF-κB signal pathway. These results provide new opportunities for the development of new anti-inflammatory and leukemic therapies.

Chondroprotective role of sesamol by inhibiting MMPs expression via retaining NF-κB signaling in activated SW1353 cells.

Overexpression of matrix metalloproteinases (MMPs) is a major pathological factor causing cartilage destruction in osteoarthritis (OA). This study aimed to investigate the effects and mechanisms of sesamol on expression of MMPs in activated chondrosarcoma cells. Sesamol significantly attenuated TNF-α- and IL-1ß-induced gelatinolysis and expression of MMP-9 in a concentration-dependent manner in SW1353 cells. Additionally, both MMP-1 and -13 stimulated by PMA were inhibited by sesamol. On the other hand, the NF-κB signaling activation through IκB-α degradation was restored by sesamol under TNF-α or PMA stimulation. Furthermore, this bioactive compound exerted the reduction on phosphorylation of ERK1/2 or p38 MAPKs after either PMA or IL-1ß stimulation. This study also evaluated whether sesamol down-regulates MMP expression in the joint cartilage of monosodium iodoacetate (MIA)-induced OA in rats. Sesamol prevented the expression of MMP-1 and -9 in the cartilage of MIA-induced OA in rats. The results of this study demonstrate that sesamol inhibits cytokine- or PMA-induced MMPs expression through the signal pathways of either NF-κB or ERK/p38 MAPKs down-regulation. This study also showed that sesamol attenuates destructive factor expression in vivo, providing a potential strategy for the chondroprotective therapy in OA.

Aristolochic acid downregulates monocytic matrix metalloproteinase-9 by inhibiting nuclear factor-κB activation.

Aristolochic acid (AA)-associated nephropathy was described as being characterized by a rapid progressive enhancement of interstitial renal fibrosis. Renal tissue fibrosis occurs because of an imbalance of extracellular matrix (ECM) accumulation and matrix metalloproteinase (MMP) activation. Much evidence indicates that inflammatory renal disease including monocyte and mesangial interactions is linked to the development and progression of renal remodeling. In this study, we found that AA showed concentration-dependent inhibition of tumor necrosis factor (TNF)-α-induced MMP-9 activation with an IC(50) value of 6.4±0.5µM in human monocytic THP-1 cells. A similar effect was also noted with different ratios of AAs (types I and II). However, AA had no inhibitory effect on the intact enzymatic activity of MMP-9 at a concentration of 20µM. On the other hand, the level of tissue inhibitor of metalloproteinase (TIMP)-1 was not induced by AA, but it suppressed TNF-α-induced MMP-9 protein and messenger RNA expressions. AA also significantly inhibited TNF-α-induced IκBα degradation. Furthermore, an electrophoretic mobility shift assay and a reported gene study, respectively, revealed that AA inhibited TNF-α-induced NF-κB translocation and activation. In addition, compared to other NF-κB inhibitors, AA exerted significant inhibition of MMP-9 activation and monocyte chemotactic protein-1-directed invasion. From these results, we concluded that AA, a natural compound, inhibits TNF-α-induced MMP-9 in human monocytic cells possibly through the NF-κB signal pathway. These results also imply that AA may be involved in alteration of matrix homeostasis during renal fibrosis in vivo.

Nuclear-targeted inhibition of NF-kappaB on MMP-9 production by N-2-(4-bromophenyl) ethyl caffeamide in human monocytic cells.

Aberrant remodeling of the extracellular matrix occurs in many pathological processes, and its breakdown is mainly accomplished by matrix metalloproteinases (MMPs), which participate in the course of inflammation and tumor invasion. Nuclear factor-kappaB (NF-kappaB), a key transcription factor for the production of MMP-9, can be activated by various proinflammatory cytokines and promotes inflammation. In the present study, we investigated the intracellular mechanism for the inhibitory effects of an analogue of N-hydroxycinnamoylphenalkylamides, N-2-(4-bromophenyl) ethyl caffeamide (EK5), on tumor necrosis factor (TNF)-alpha stimulated expression of MMP-9 in a human monocytic cell line, THP-1. Our results show that TNF-alpha-induced expression of MMP-9 at both mRNA and protein levels was completely blocked by EK5 in a concentration-dependent (1-20microM) manner. We also found that EK5 markedly suppressed NF-kappaB signaling as detected by the NF-kappaB reporter gene assay but had no effects on the degradation of IkappaBalpha or translocation of NF-kappaB. Interestingly, chromatin immunoprecipitation results revealed that the association between p65 and MMP-9 promoter gene was completely abrogated by EK5, but the p65 phosphorylation was not affected. Overall, our findings suggest that EK5 inhibits MMP-9 production through the nuclear-targeted down-regulation of NF-kappaB signaling in human monocytic cells and this may provide a novel molecular basis of EK5 activity. Further studies are needed to verify its anti-inflammatory effects.