Association between clinical use of nifedipine and the risk of osteoporosis: a nationwide retrospective cohort study.

Nifedipine is one of the common calcium channel blockers (CCBs) for hypertension that induce peroxisome-proliferator-activated receptor γ coactivator 1-α, which is envisioned as a potential therapeutic target in bone disease. The findings of this retrospective cohort study suggest that patients who receive nifedipine may have a potential protective effect on osteoporosis in comparison to other CCBs. INTRODUCTION: Nifedipine was one L-type dihydropyridine calcium channel blocker (CCB) that can improve bone loss. However, epidemiological studies on the association between the use of nifedipine and osteoporosis risk are limited. Thus, this study aimed to evaluate the association between the clinical use of nifedipine and the risk of osteoporosis. METHODS: This retrospective cohort was conducted using the National Health Insurance Research Database of Taiwan from 2000 to 2013. The study includes 1225 patients receiving nifedipine (the exposed cohort) and 4900 patients receiving other CCBs (the comparison cohort). The primary outcome was the diagnosis of osteoporosis. The hazard ratios (HRs) and 95% confidence intervals (CIs) were used to assess the association between the use of nifedipine and the risk of osteoporosis. RESULTS: Patients receiving nifedipine treatment had a reduced risk of osteoporosis as compared with those undergoing other CCB treatments (adjusted HR, 0.44; 95% CI, 0.37-0.53). Moreover, this inverse association is evident in both sexes and various age groups. CONCLUSIONS: This population-based cohort study demonstrated that nifedipine may have potential protective effect on osteoporosis compared with other CCBs. The clinical implications of the present study need further investigation.

Investigation of cell cytotoxic activity and molecular mechanism of 5ß,19-epoxycucurbita-6,23(E)-diene-3ß,19(R),25-triol isolated from Momordica charantia on hepatoma cells.

CONTEXT: Momordica charantia L. (Cucurbitaceae), known as bitter melon, is an edible fruit cultivated in the tropics. In this study, an active compound, 5ß,19-epoxycucurbita-6,23(E)-diene-3ß,19(R),25-triol (ECDT), isolated from M. charantia was investigated in regard to its cytotoxic effect on human hepatocellular carcinoma (HCC) cells. OBJECTIVE: To examine the mechanisms of ECDT-induced apoptosis in HCC cells. MATERIALS AND METHODS: The inhibitive activity of ECDT on HA22T HCC cells was examined by MTT assay, colony formation assay, wound healing assay, TUNEL/DAPI staining, annexin V-fluorescein isothiocyanate/propidium iodide (PI) staining and JC-1 dye. HA22T cells were treated with ECDT (5, 10, 15, 20 and 25 µM) for 24 h, and the molecular mechanism of cells apoptosis was examined by Western blot. Cells treated with vehicle DMSO were used as the negative control. RESULTS: ECDT inhibited the cell proliferation of HA22T cells in a dose-dependent manner. Flow cytometry showed that ECDT treatment at 10-20 µM increased early apoptosis by 10-14% and late apoptosis by 2-5%. Western blot revealed that ECDT treatment activated the mitochondrial-dependent apoptotic pathway, and ECDT-induced apoptosis was mediated by the caspase signalling pathway and activation of JNK and p38MAPK. Pre-treatment of cells with MAPK inhibitors (SB203580 or SP600125) reversed the ECDT-induced cell death, which further supported the involvement of the p38MAPK and JNK pathways. DISCUSSION AND CONCLUSIONS: Our results indicated that ECDT can induce apoptosis through the p38MAPK and JNK pathways in HA22T cells. The findings suggested that ECDT has a valuable anticancer property with the potential to be developed as a new chemotherapeutic agent for the treatment of HCC.

Involvement of Mitochondrial Dysfunction, Endoplasmic Reticulum Stress, and the PI3K/AKT/mTOR Pathway in Nobiletin-Induced Apoptosis of Human Bladder Cancer Cells.

Nobiletin (NOB) is a polymethoxylated flavonoid isolated from citrus fruit peel that has been shown to possess anti-tumor, antithrombotic, antifungal, anti-inflammatory and anti-atherosclerotic activities. The main purpose of this study was to explore the potential of using NOB to induce apoptosis in human bladder cancer cells and study the underlying mechanism. Using an MTT assay, agarose gel electrophoresis, a wound-healing assay, flow cytometry, and western blot analysis, this study investigated the signaling pathways involved in NOB-induced apoptosis in BFTC human bladder cancer cells. Our results showed that NOB at concentrations of 60, 80, and 100 µM inhibited cell growth by 42%, 62%, and 80%, respectively. Cells treated with 60 µM NOB demonstrated increased DNA fragmentation, and flow cytometry analysis confirmed that the treatment caused late apoptotic cell death. Western blot analysis showed that mitochondrial dysfunction occurred in NOB-treated BFTC cells, leading to cytochrome C release into cytosol, activation of pro-apoptotic proteins (caspase-3, caspase-9, Bad, and Bax), and inhibition of anti-apoptotic proteins (Mcl-1, Bcl-xl, and Bcl-2). NOB-induced apoptosis was also mediated by regulating endoplasmic reticulum stress via the PERK/elF2α/ATF4/CHOP pathway, and downregulating the PI3K/AKT/mTOR pathway. Our results suggested that the cytotoxic and apoptotic effects of NOB on bladder cancer cells are associated with endoplasmic reticulum stress and mitochondrial dysfunction.

Flaccidoxide-13-Acetate Extracted from the Soft Coral Cladiella kashmani Reduces Human Bladder Cancer Cell Migration and Invasion through Reducing Activation of the FAK/PI3K/AKT/mTOR Signaling Pathway.

Metastasis of cancer is the cause of the majority of cancer deaths. Active compound flaccidoxide-13-acetate, isolated from the soft coral Cladiella kashmani, has been found to exhibit anti-tumor activity. In this study, Boyden chamber analysis, Western blotting and gelatin zymography assays indicated that flaccidoxide-13-acetate exerted inhibitory effects on the migration and invasion of RT4 and T24 human bladder cancer cells. The results demonstrated that flaccidoxide-13-acetate, in a concentration-dependent manner, reduced the levels of matrix metalloproteinase-2 (MMP-2), MMP-9, urokinase-type plasminogen activator receptor (uPAR), focal adhesion kinase (FAK), phosphatidylinositide-3 kinases (PI3K), p-PI3K, AKT, p-AKT, mammalian target of rapamycin (mTOR), p-mTOR, Ras homolog gene family, member A (Rho A), Ras, mitogen-activated protein kinase kinase 7 (MKK7) and mitogen-activated protein kinase kinase kinase 3 (MEKK3), and increased the expressions of tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2 in RT4 and T24 cells. This study revealed that flaccidoxide-13-acetate suppressed cell migration and invasion by reducing the expressions of MMP-2 and MMP-9, regulated by the FAK/PI3K/AKT/mTOR pathway. In conclusion, our study was the first to demonstrate that flaccidoxide-13-acetate could be a potent medical agent for use in controlling the migration and invasion of bladder cancer.

Suppression of Migration and Invasion by 4-Carbomethoxyl-10-Epigyrosanoldie E from the Cultured Soft Coral Sinularia sandensis through the MAPKs Pathway on Oral Cancer Cells.

The primary reason for cancer-related fatalities is metastasis. The compound 4-carbomethoxyl-10-epigyrosanoldie E, derived from the Sinularia sandensis soft coral species grown in cultures, exhibits properties that counteract inflammation. Moreover, it has been observed to trigger both apoptosis and autophagy within cancerous cells. This research focuses on examining the inhibitory impact of 4-carbomethoxyl-10-epigyrosanoldie E on the migration and invasion processes in Cal-27 and Ca9-22 oral cancer cell lines. To assess how this compound affects cell migration and invasion, the Boyden chamber assay was employed. Furthermore, Western blot analysis was utilized to explore the underlying molecular mechanisms. In a dose-dependent manner, 4-carbomethoxyl-10-epigyrosanoldie E notably decreased the levels of matrix metalloproteinase-2 (MMP-2) and MMP-9, along with urokinase-type plasminogen activator (uPA), in both Cal-27 and Ca9-22 cell lines. Conversely, it elevated the concentrations of tissue inhibitors of metalloproteinases-1 (TIMP-1) and TIMP-2. In addition, the treatment with this compound led to the inhibition of phosphorylation in extracellular signal-regulated kinase (ERK), p38, and c-Jun N-terminal kinase (JNK). It also curtailed the expression of several key proteins including focal adhesion kinase (FAK), protein kinase C (PKC), growth factor receptor-bound protein 2 (GRB2), Rac, Ras, Rho A, mitogen-activated protein kinase kinase kinase 3 (MEKK3), and mitogen-activated protein kinase kinase 7 (MKK7). Furthermore, the expression levels of IQ-domain GTPase-activating protein 1 (IQGAP1) and zonula occludens-1 (ZO-1) were significantly reduced by the compound. The ability of 4-carbomethoxyl-10-epigyrosanoldie E to inhibit the migration and invasion of Cal-27 and Ca9-22 oral cancer cells was observed to be dose dependent. This inhibitory effect is primarily attributed to the suppression of MMP-2 and MMP-9 expression, as well as the downregulation of the mitogen-activated protein kinase (MAPK) signaling pathway.

Association between clinical use of lansoprazole and the risk of type 2 diabetes mellitus: a pharmacoepidemiological cohort study.

BACKGROUND: Proton pump inhibitors (PPIs) are common and widely used for gastrointestinal-related disorders. Lansoprazole is one of PPIs with potential benefits of anti-inflammation, reduced oxidative stress, and anti-diabetes. The aims of this study are to determine whether lansoprazole imparts differential risk of type 2 diabetes as compared with other PPIs. METHODS: A population-based retrospective cohort study was conducted using the National Health Insurance Research Database in Taiwan. Patients who received lansoprazole more than 90 days and without records of use of other PPIs between January 1, 2000 and December 31, 2005 (the exposure period) were considered as the exposed cohort (n = 1668). In comparison, patients who received other PPIs more than 90 days and without use of lansoprazole in the exposure period were treated as the comparison cohort (n = 3336).The primary outcome was the new-onset of type 2 diabetes mellitus (T2DM). The association between use of lansoprazole and the risk of T2DM was determined by hazard ratios (HRs) and 95% confidence intervals (CIs) derived from multivariable Cox proportional hazards models. RESULTS: The lansoprazole cohort showed a significantly reduced risk of T2DM with an adjusted HR of 0.65 (95% CI 0.56-0.76). Interestingly, the inverse association between use of lansoprazole and risk of T2DM was observed in both genders and in various age groups. CONCLUSION: The present study findings suggest that lansoprazole was associated with a reduced risk of T2DM compared with other PPIs. Further studies are needed to determine the clinical implications of the present study.

Stellettin B Isolated from Stelletta Sp. Reduces Migration and Invasion of Hepatocellular Carcinoma Cells through Reducing Activation of the MAPKs and FAK/PI3K/AKT/mTOR Signaling Pathways.

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors, and there is currently a lack of effective treatment options to control the metastasis. This study was performed to examine the mechanisms of the migration and invasion characteristics of HCC, with the aim of reducing metastasis by inhibiting cancer cell migration and invasion. In this study, we used Stellettin B, an active compound isolated from Stelletta sponges, as the experimental drug and evaluated its inhibition effects on cell migration and invasion in human hepatoma cells (HA22T and HepG2). MTT assay, gelatin zymography, and western blotting were employed. The results showed that Stellettin B significantly inhibited the protein expressions of MMP-2, MMP-9, and uPA, while upregulating the protein expressions of TIMP-1 and TIMP-2. The expressions of p-FAK, p-PI3K, p-AKT, p-mTOR, and MAPKs (p-JNK, p-JUN, p-MAPKp38, and p-ERK) were decreased with increasing concentrations of Stellettin B. Our results suggest that Stellettin B-dependent downregulation of MMP-2 and MMP-9 activities could be mediated by FAK/PI3K/AKT/mTOR and MAPKs signaling pathways in HA22T and HepG2 cells, preventing HCC invasion and migration.

Antimelanogenesis Effect of Methyl Gallate through the Regulation of PI3K/Akt and MEK/ERK in B16F10 Melanoma Cells.

Methyl gallate is a polyphenolic compound found in many plants, and its antioxidant, antitumor, antibacterial, and anti-inflammatory effects have been extensively studied. More recently, antidepressant-like effects of methyl gallate have been demonstrated in some studies. In the present study, we examined the effects of methyl gallate on melanogenesis, including the tyrosinase inhibitory effect, the melanin content, and the molecular signaling pathways involved in this inhibition. The results showed that methyl gallate inhibited tyrosinase activity and significantly downregulated the expressions of melanin synthesis-associated proteins, including microphthalmia-associated transcription factor (MITF), tyrosinase, dopachrome tautomerase (Dct), and tyrosinase-related protein-1 (TRP1). In conclusion, our findings indicated that activation of MEK/ERK and PI3K/Akt promoted by methyl gallate caused downregulation of MITF and triggered its downstream signaling pathway, thereby inhibiting the production of melanin. In summary, methyl gallate showed significant inhibitory activity against melanin formation, implying that it may be a potential ingredient for application in skin-whitening cosmetics.

Clinical Use of Lansoprazole and the Risk of Osteoporosis: A Nationwide Cohort Study.

BACKGROUND: Proton pump inhibitor (PPI) lansoprazole acts as a liver X receptor agonist, which plays a crucial role in the crosstalk of osteoblasts and osteoclasts in vitro and during bone turnover in vivo. However, epidemiological studies on the association between the use of lansoprazole and osteoporosis risk are limited. We aimed to determine the risk of developing osteoporosis in patients with lansoprazole use. METHODS: A retrospective cohort study was conducted using the National Health Insurance Research Database of Taiwan dated from 2000 to 2013. The study includes 655 patients with lansoprazole use (the exposed cohort) and 2620 patients with other PPI use (the comparison cohort). The main outcome was the primary diagnosis of osteoporosis. The hazard ratios (HRs) and 95% confidence intervals (CIs) were used to assess the association between the use of lansoprazole and risk of osteoporosis. RESULTS: Patients receiving lansoprazole treatment had a reduced risk of osteoporosis as compared with those undergoing other PPI therapy (adjusted HR, 0.56; 95% CI, 0.46-0.68). Moreover, this inverse association is evident in both sexes and in various age groups. CONCLUSIONS: This population-based cohort study demonstrated that lansoprazole use was associated with a reduced risk of osteoporosis. The clinical implications of the present study need further investigations.

Association between Non-Steroidal Anti-Inflammatory Drugs Use and the Risk of Type 2 Diabetes Mellitus: A Nationwide Retrospective Cohort Study.

BACKGROUND: Although the link between non-steroidal anti-inflammatory drugs (NSAIDs) and tramadol and symptomatic hypoglycemia has been documented, there is a limited understanding of the associations of NSAIDs and tramadol with the risk of type 2 diabetes mellitus (T2DM). This study was established to evaluate the association between the clinical use of NSAIDs and the risk of T2DM. PATIENTS AND METHODS: A historical cohort study was conducted using the National Health Insurance Research Database in Taiwan dated from 2000 to 2013. Patients who received NSAIDs for at least 3 prescription orders and without co-treatment of tramadol in the exposure period (from 2000 to 2005) were considered as the exposed cohort (n = 3047). In comparison, patients who received tramadol for at least 3 prescription orders and without concomitant use of NSAIDs in the exposure period were considered as the comparison cohort (n = 9141). The primary outcome was the occurrence of T2DM. Multivariable hazard ratios (HRs) with 95% confidence intervals (CIs) derived from the Cox proportional hazard models were applied to determine the association between NSAIDs use and the risk of T2DM. RESULTS: In the average follow-up period of 9.56 years, there were 159 newly diagnosed T2DM, with an incidence rate of 56.96 per 10,000 person years in the exposed cohort. Comparatively, there were 1737 incident T2DM cases, with an incidence rate of 161.23 per 10,000 person years in the comparison cohort. Compared to the comparison cohort, the NSAIDs cohort showed a significantly reduced risk of T2DM with an adjusted HR of 0.31 (95% CI, 0.26-0.36). CONCLUSIONS: Our cohort study provides longitudinal evidence that the use of NSAIDs was associated with a reduced risk of T2DM.

Association between Clinical Use of Colchicine and Risk of Type 2 Diabetes Mellitus among Gouty Patients: A Nationwide Cohort Study.

BACKGROUND: Gout is the most common form of inflammatory arthritis in adults. Even though a link between gouty arthritis and type 2 diabetes mellitus (T2DM) has been reported, there is a limited understanding of the association between the anti-inflammatory agent colchicine and the risk of T2DM. This aim of this study was to assess the association between the use of colchicine and the risk of T2DM in an Asian cohort. METHODS: A retrospective cohort study was conducted using the National Health Insurance Research Database (NHIRD) in Taiwan from 2000 to 2013. The study cohorts comprised 3841 gouty patients using colchicine (the exposed cohort) and 7682 gouty patients not using colchicine (the unexposed -cohort). The primary outcome was incident DM. The hazard ratios (HRs) and 95% confidence intervals (CIs) derived from a Cox proportional regression model were used to assess the association between colchicine use and the risk of diabetes. RESULTS: The cumulative incidence of T2DM was significantly lower in the exposed cohort (18.8%) than in the unexposed cohort (25.0%). The risk of T2DM was significantly lower in colchicine users than in non-users (adjusted HR, 0.74; 95% CI, 0.36-0.87). The inverse relationship between colchicine use and diabetes risk remained consistent across sex and age groups. CONCLUSIONS: This cohort study provides longitudinal evidence that the use of colchicine is associated with a reduced risk of T2DM. This conclusion, however, needs to be interpreted cautiously given the lack of body mass index data in the NHIRD. Further studies are needed to determine the clinical implications of this study.

Flaccidoxide Induces Apoptosis Through Down-regulation of PI3K/AKT/mTOR/p70S6K Signaling in Human Bladder Cancer Cells.

BACKGROUND/AIM: Urothelial carcinoma (UC) is the most common type of genitourinary cancer with high incidence and mortality rates in men. In this study, we used the BFTC-905 and T24 bladder cancer cell lines as in vitro models to investigate the pathways involved in flaccidoxide-induced apoptosis. MATERIALS AND METHODS: We utilized MTT assays, colony assays, wound-healing assays and fluorescence with TUNEL to confirm the cytotoxicity of flaccidoxide in bladder cancer cell lines. Potential proliferative and apoptotic molecular mechanisms were evaluated by western blotting. RESULTS: The expression of anti-apoptotic proteins Bcl-2 and phosphorylated Bad (p-Bad) was attenuated with an increasing flaccidoxide concentration, while the expression of proapoptotic proteins Bax, Bad, cleaved caspase-3, cleaved caspase-9 and cleaved PARP-1 was found increased. Additionally, phosphorylation of phosphoinositide 3-kinases (PI3K), protein kinase B (AKT) and mammalian target of rapamycin (mTOR) in the PI3K/AKT/mTOR pathway was reduced, leading to a reduction in the phosphorylation of downstream 70-kDa ribosomal protein S6 kinase 1 (p70S6K), S6 ribosomal protein (S6) and eukaryotic translation initiation factor 4B (eIF4B). However, eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1) protein phosphorylation was increased due to attenuation of the upstream phosphorylation of mTOR protein. CONCLUSION: Flaccidoxide-induced apoptosis in BFTC-905 and T24 cells is mediated by mitochondrial dysfunction and down-regulation the PI3K/AKT/mTOR/p70S6K signaling pathway.

Clinical Use of Acid Suppressants and Risk of Dementia in the Elderly: A Pharmaco-Epidemiological Cohort Study.

BACKGROUND: Results of studies regarding the potential link between acid suppressant use and dementia risk are inconsistent. This study aimed to evaluate the association of cumulative exposure to histamine 2 receptor antagonists (H2RAs) and proton pump inhibitors (PPIs) with dementia risk in an Asian older cohort aged ≥65 years. METHODS: Patients initiating H2RA (the H2RA user cohort, n = 21,449) or PPI (the PPI user cohort, n = 6584) and those without prescription for H2RA (the H2RA non-user cohort, n = 21,449) or PPI (the PPI non-user cohort, n = 6584) between 1 January 2000 and 31 December 2005 without a prior history of dementia were identified from Taiwan's National Health Insurance Research Database (NHIRD). The outcome of interest was all-cause dementia. Patients' exposure to H2RAs or PPIs was followed-up from dates of initial prescription to the earliest outcome of incident dementia, death, or the end of 2013. Potential associations between acid suppressant use and dementia risk were analyzed using time-dependent Cox regression estimated hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: After mutual adjustment for H2RA and PPI use and other potential confounders, patients with H2RA use had significantly higher risk of developing dementia as compared to those not treated with H2RAs (adjusted HR, 1.84; 95% CI, 1.49-2.20). Likewise, PPI users had significantly elevated risk of dementia compared to PPI non-users (adjusted HR, 1.42; 95% CI, 1.07-1.84). CONCLUSIONS: Our results indicate that exposures to H2RAs and PPIs are associated with increased dementia risk.

Amphiregulin promotes cisplatin chemoresistance by upregulating ABCB1 expression in human chondrosarcoma.

Chondrosarcomas are well known for their resistance to chemotherapeutic agents, including cisplatin, which is commonly used in chondrosarcomas. Amphiregulin (AR), a ligand of epidermal growth factor receptor (EGFR), plays an important role in drug resistance. We therefore sought to determine the role of AR in cisplatin chemoresistance. We found that AR inhibits cisplatin-induced cell apoptosis and promotes ATP-binding cassette subfamily B member 1 (ABCB1) expression, while knockdown of ABCB1 by small interfering RNA (siRNA) reverses these effects. High phosphoinositide 3-kinase (PI3K), Akt and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) phosphorylation levels were observed in cisplatin-resistant cells. Pretreating chondrosarcoma cells with PI3K, Akt and NF-κB inhibitors or transfecting the cells with p85, Akt and p65 siRNAs potentiated cisplatin-induced cytotoxicity. In a mouse xenograft model, knockdown of AR expression in chondrosarcoma cells increased the cytotoxic effects of cisplatin and also decreased tumor volume and weight. These results indicate that AR upregulates ABCB1 expression through the PI3K/Akt/NF-κB signaling pathway and thus contributes to cisplatin resistance in chondrosarcoma.

Cardiovascular Outcomes Associated With Clinical Use of Citalopram and Omeprazole: A Nationwide Population-Based Cohort Study.

Background Recent studies have raised concerns about the reduced efficacy of citalopram when used concurrently with proton pump inhibitors. The aim of this study was to evaluate the associations between clinical use of citalopram and omeprazole and the risk of sudden cardiac arrest (SCA) in an Asian population. Methods and Results A retrospective cohort study was conducted using the National Health Insurance Research Database of Taiwan dated from 2000 to 2013. The study cohorts comprised 3882 patients with citalopram use alone, 31 090 patients with omeprazole use alone, and 405 patients with concomitant use of citalopram and omeprazole (as the exposed cohort), and 141 508 patients received treatment with antidepressants without the risk of SCA and/or proton pump inhibitors other than omeprazole (as the comparison cohort). The primary outcome was the occurrence of SCA. The hazard ratios and 95% CIs derived from the time-dependent Cox regression model were used to assess the association between the proposed drug treatments and risk of SCA. The adjusted hazard ratios of SCA was 1.32 (95% CI, 1.17-1.50) for citalopram use alone, 1.08 (95% CI, 0.98-1.20) for omeprazole use alone, and 2.23 (95% CI, 1.79-2.78) for concomitant use of citalopram and omeprazole. The cumulative incidence of SCA over the Kaplan-Meier curves was more pronounced in patients with concomitant use of citalopram and omeprazole than those treated with citalopram alone and omeprazole alone. Conclusions This cohort study demonstrated use of citalopram and omeprazole either in isolation use or in concomitant use to be at increased risk for SCA.

Proteasome inhibitors up-regulate haem oxygenase-1 gene expression: requirement of p38 MAPK (mitogen-activated protein kinase) activation but not of NF-kappaB (nuclear factor kappaB) inhibition.

Regulation of intracellular protein stability by the ubiquitin-dependent proteasome system plays a crucial role in cell function. HO-1 (haem oxygenase) is a stress response protein, which confers cytoprotection against oxidative injury and provides a vital function in maintaining tissue homoeostasis. In the present study, we found a novel action of proteasome inhibitors MG132 and MG262 on HO-1 induction, and characterized the underlying mechanisms. MG132 (> or =0.1 microM) treatment resulted in a marked time- and concentration-dependent induction of the steady-state level of HO-1 mRNA in RAW264.7 macrophages, followed by a corresponding increase in HO-1 protein. Actinomycin D and cycloheximide inhibited MG132-responsive HO-1 protein expression, indicating a requirement for transcription and de novo protein synthesis. The involvement of signal pathways in MG132-induced HO-1 gene expression was examined using chemical inhibitors. Antioxidant N -acetylcysteine and SB203580, an antioxidant and inhibitor of p38 MAPK (mitogen-activated protein kinase), abolished MG132-inducible HO-1 expression. Furthermore, MG132 activated the p38 MAPK pathway. The half-life of HO-1 protein was prolonged by MG132, indicating that the upregulation of HO-1 by proteasome inhibitor is partially attributable to the inhibition of protein degradation. MG132 can ablate IkappaBalpha degradation and NF-kappaB (nuclear factor kappaB) activation induced by lipopolysaccharide, similar to the effect of another NF-kappaB inhibitor pyrrolidine dithiocarbamate. We found HO-1 upregulation by MG132 and pyrrolidine dithiocarbamate is unrelated to their inhibition of NF-kappaB, since leptomycin B, another NF-kappaB inhibitor, did not elicit similar induction of HO-1. Taken together, we found a novel effect of proteasome inhibitor on induction of HO-1 expression. This action is ascribed to the activation of the p38 MAPK pathway, but is not dependent on NF-kappaB inhibition.

Signal transduction for inhibition of inducible nitric oxide synthase and cyclooxygenase-2 induction by capsaicin and related analogs in macrophages.

1. Although capsaicin analogs might be a potential strategy to manipulate inflammation, the mechanism is still unclear. In this study, the effects and action mechanisms of vanilloid analogs on iNOS and COX-2 expression were investigated in RAW264.7 macrophages. 2. Capsaicin and resiniferatoxin (RTX) can inhibit LPS- and IFN-gamma-mediated NO production, and iNOS protein and mRNA expression with similar IC50 values of around 10 microm. 3. Capsaicin also transcriptionally inhibited LPS- and PMA-induced COX-2 expression and PGE2 production. However, this effect exhibited a higher potency (IC50: 0.2 microm), and RTX failed to elicit such responses at 10 microm. 4. Interestingly, we found that capsazepine, a competitive TRPV1 antagonist, did not prevent the inhibition elicited by capsaicin or RTX. Nevertheless, it mimicked vanilloids in inhibiting iNOS/NO and COX-2/PGE2 induction with an IC50 value of 3 microm. RT-PCR and immunoblotting analysis excluded the expression of TRPV1 in RAW264.7 macrophages. 5. The DNA binding assay demonstrated the abilities of vanilloids to inhibit LPS-elicited NF-kappaB and AP-1 activation and IFN-gamma-elicited STAT1 activation. The reporter assay of AP-1 activity also supported this action. 6. The kinase assay indicated that ERK, JNK, and IKK activation by LPS were inhibited by vanilloids. 7. In conclusion, vanilloids can modulate the expression of inflammatory iNOS and COX-2 genes in macrophages through interference with upstream signalling events of LPS and IFN-gamma. These findings provide new insights into the potential benefits of the active ingredient in hot chilli peppers in inflammatory conditions.

Association of intercellular adhesion molecular-1 gene polymorphism in ischemic stroke patients.

BACKGROUND: Ischemic stroke (IS) is a prevalent disease causing a body disability, the third leading cause of death in Taiwan. It shows that the level of intercellular adhesion molecular-1 (ICAM-1) in IS patients is higher than control subjects. OBJECTIVE: This study is to investigate the possible association of ICAM-1 (G1548A) polymorphism in IS patients. MATERIALS AND METHODS: A total of 646 subjects were enrolled in this study, including 312 IS patients, and 334 controls without a history of symptomatic IS. The ICAM-1 (G1548A) polymorphism was analyzed by polymerase chain reaction and restriction fragment length polymorphism. Clinical factors were also determined. RESULTS: The frequencies of the ICAM-1 (G1548A) polymorphism for G/G, G/A, and A/A were 74.8%, 23.9%, and 0.3%, respectively, in healthy controls, and 62.8%, 32.1%, and 5.1%, respectively, in patients. The frequency of the ICAM-1 (G1548A) A allele (21.2% versus 13.2%, respectively; P = 0.007) and the carriers of the ICAM-1 (G1548A) A allele (37.2% versus 25.2%; P = 0.019, OR 1.76, 95% CI 1.1-2.83) are great in IS patients compared with healthy controls. There is a higher risk of IS associated with homozygosity for the ICAM-1 (G1548A) A allele (AA genotype) compared with the control population (5.1% vs. 0.3%, respectively, P = 0.04; OR 5.1, 95% CI 1.19-21.66). We also observed both hypertension and diabetes has shown a positive association with IS. CONCLUSIONS: The ICAM-1 (G1548A) polymorphism was associated with independent risk factor for the development of IS.

Evaluation of anti-inflammatory effects of Broussonetia papyrifera stem bark.

OBJECTIVE: Broussonetia papyrifera is used as a traditional medicine to treat few diseases. However, the antiinflammatory effect of B. papyrifera stem bark has not been evaluated. The aim of this study is to investigate the effects of n-hexane fraction from methanol extract of B. papyrifera stem bark on lipopolysaccharide (LPS)-stimulated inflammation using RAW 264.7 cells. MATERIALS AND METHODS: Methanol extract was obtained from B. papyrifera stem bark and its sequential fractions (hexane, dichloromathane, ethyl acetate, butanol, and aqueous) were obtained by extraction in solvents with increasing polarity and were examined in RAW 264.7 cells. RESULTS: The secretion profiles of pro-inflammatory parameters, including nitric oxide (NO), tumor necrosis factor-α (TNF-α), and interleukin-1ß (IL-1ß) were found to be significantly reduced in 10-80 µg/ml dose ranges of n-hexane fraction (BP-H) from methanol extract of B. papyrifera stem bark. The expressions of inducible NO synthase (iNOS) was also significantly inhibited by BP-H. Reverse transcription-polymerase chain reaction (RT-PCR) analysis showed that BP-H treatment decreased LPS-induced iNOS mRNA expression in RAW 264.7 cells. CONCLUSION: The results suggest that the B. papyrifera stem bark has anti-inflammatory activity which inhibits the NO production and proinflammatory cytokines in RAW 264.7 cells. B. papyrifera stem bark might act as a potential therapeutic agent for inflammatory diseases.

Interleukin-1 receptor antagonist gene polymorphism in patients with multidrug-resistant Acinetobacter baumannii-associated pneumonia.

OBJECTIVE: Multidrug-resistant Acinetobacter baumannii (MDRAB)-associated pneumonia has been a common disease and a therapeutic problem in hospitals. Interleukin-1 receptor antagonist (IL-1ra) has been considered a required role for host immune defense in pneumonia disease. The aim of this study was to investigate whether the variable nucleotide tandem repeat polymorphism of the IL-1ra gene was associated with MDRAB-related pneumonia. METHODS: Sixty-six pneumonia patients were enrolled in the study: 36 subjects had MDRAB-related pneumonia and 30 controls had non-MDRAB pneumonia. Polymerase chain reaction, restriction fragment length polymorphism, and agarose gel electrophoresis techniques were used to determine the IL-1ra genotype. RESULTS: The frequencies of the IL-1ra genotype in the MDRAB-related pneumonia cases were A1/A1, 0.889 and A1/A2, 0.111; the frequencies of the IL-1ra genotype in the controls were A1/A1, 0.333 and A1/A2, 0.667. A statistically significant difference was determined (P < 0.05). We also observed an increase in the frequency of IL-1ra A1 allele in the MDRAB-related pneumonia group. A statistically significant difference was determined (P<0.05). CONCLUSIONS: We suggested that IL-1ra polymorphism was associated with the risk of MDRAB-related pneumonia.