MicroRNA-302b-inhibited E2F3 transcription factor is related to all trans retinoic acid-induced glioma cell apoptosis

All-trans retinoic acid (ATRA), a derivative of retinoid, is involved in the onset of differentiation and apoptosis in a wide variety of normal and cancer cells. MicroRNAs (miRNAs) are small non-coding RNAs that control gene expression. Several miRNAs were identified to participate in ATRA-mediated cell differentiation. However, no studies have demonstrated whether miRNA can enhance ATRA cytotoxicity, thereby resulting in cell apoptosis. This study investigated the effects of ATRA-mediated miRNA expression in activating apoptotic pathways in glioblastoma. First, we found that high-dose ATRA treatment significantly reduced cell viability, caspase-dependent apoptosis, endoplasmic reticular (ER) stress activation, and intracellular reactive oxygen species accumulation. From microarray data, miR-302b was analyzed as a putative downstream regulator upon ATRA treatment. Furthermore, we found that ATRA up-regulated miR-302b expression in a dose- and time-dependent manner through retinoic acid receptor α-mediated pathway. Overexpression and knockdown of miR-302b significantly influenced ATRA-mediated cytotoxicity. E2F3, an important transcriptional regulator of glioma proliferation, was validated to be a direct target gene of miR-302b. The miR-302b-reduced E2F3 levels were also identified to be associated with ATRA-mediated glioma cell death. These results emphasize that an ATRA-mediated miR-302b network may provide novel therapeutic strategies for glioblastoma therapy. We propose that high-dose all-trans retinoic acid (ATRA) treatment, a derivative of retinoid, significantly induces glioblastoma cell apoptosis via caspase-dependent apoptosis, endoplasmic reticular (ER) stress, and intracellular reactive oxygen species (ROS) accumulation. The miR-302b overexpression enhanced by ATRA-mediated retinoic acid receptor (RAR)α pathway was also identified. The E2F3 repression, a novel target gene of miR-302b, was involved in ATRA-induced glioblastoma cell cytotoxicity.

Effect of JJYMD-C, a novel synthetic derivative of gallic acid, on proliferation and phenotype maintenance in rabbit articular chondrocytes in vitro

Tissue engineering encapsulated cells such as chondrocytes in the carrier matrix have been widely used to repair cartilage defects. However, chondrocyte phenotype is easily lost when chondrocytes are expanded in vitro by a process defined as “dedifferentiation”. To ensure successful therapy, an effective pro-chondrogenic agent is necessary to overcome the obstacle of limited cell numbers in the restoration process, and dedifferentiation is a prerequisite. Gallic acid (GA) has been used in the treatment of arthritis, but its biocompatibility is inferior to that of other compounds. In this study, we modified GA by incorporating sulfamonomethoxine sodium and synthesized a sulfonamido-based gallate, JJYMD-C, and evaluated its effect on chondrocyte metabolism. Our results showed that JJYMD-C could effectively increase the levels of the collagen II, Sox9, and aggrecan genes, promote chondrocyte growth, and enhance secretion and synthesis of cartilage extracellular matrix. On the other hand, expression of the collagen I gene was effectively down-regulated, demonstrating inhibition of chondrocyte dedifferentiation by JJYMD-C. Hypertrophy, as a characteristic of chondrocyte ossification, was undetectable in the JJYMD-C groups. We used JJYMD-C at doses of 0.125, 0.25, and 0.5 µg/mL, and the strongest response was observed with 0.25 µg/mL. This study provides a basis for further studies on a novel agent in the treatment of articular cartilage defects.

Podocalyxin-like 1 promotes invadopodia formation and metastasis through activation of Rac1/Cdc42/cortactin signaling in breast cancer cells

Metastatic disease is the leading cause of cancer mortality. Identifying biomarkers and regulatory mechanisms is important toward developing diagnostic and therapeutic tools against metastatic cancer. In this study, we demonstrated that podocalyxin-like 1 (PODXL) is overexpressed in breast tumor cells and increased in lymph node metastatic cancer. Mechanistically, we found that the expression of PODXL was associated with cell motility and invasiveness. Suppression of PODXL in MDA-MB-231 cells reduced lamellipodia formation and focal adhesion kinase (FAK) and paxillin phosphorylation. PODXL knockdown reduced the formation of invadopodia, such as inhibiting the colocalization of F-actin with cortactin and suppressing phosphorylation of cortactin and neural Wiskott-Aldrich syndrome protein. Conversely, overexpression of PODXL in MCF7 cells induced F-actin/cortactin colocalization and enhanced invadopodia formation and activation. Invadopodia activity and tumor invasion in PODXL-knockdown cells are similar to that in cortactin-knockdown cells. We further found that the DTHL motif in PODXL is crucial for regulating cortactin phosphorylation and Rac1/Cdc42 activation. Inhibition of Rac1/Cdc42 impeded PODXL-mediated cortactin activation and FAK and paxillin phosphorylation. Moreover, inhibition of PODXL in MDA-MB-231 cells significantly suppressed tumor colonization in the lungs and distant metastases, similar to those in cortactin-knockdown cells. These findings show that overexpression of PODXL enhanced invadopodia formation and tumor metastasis by inducing Rac1/Cdc42/cortactin signaling network.

Podocalyxin-like 1 is associated with tumor aggressiveness and metastatic gene expression in human oral squamous cell carcinoma

Metastasis-mediated death remains a major challenge in cancer treatment due to the lack of identifiable biomarkers for early diagnosis. Identifying tumor-specific biomarkers is critical for the development of diagnostic and therapeutic tools. In the present study, we found that podocalyxin-like 1 (PODXL), a cell surface glycoprotein, was overexpressed in cancer tissues and was upregulated in lymph node metastatic tumor cells. The expression of PODXL was associated with the migratory ability of human oral squamous cell carcinoma (OSCC). Knockdown of PODXL by small hairpin RNA in the SAS OSCC cell line reduced tumor migration and invasion, and inhibited cell proliferation and colony formation. Suppression of PODXL resulted in downregulation of focal adhesion kinase (FAK) and paxillin phosphorylation. PODXL silencing inhibited filopodia formation, and suppressed F-actin and cortactin colocalization. In addition, PODXL expression was associated with the DNA methylation status, and treatment with the DNA methyltransferase inhibitor 5-aza-deoxycytidine increased the PODXL transcriptional level. Moreover, DNA microarray analysis data revealed that suppression of PODXL significantly affected subsets of genes associated with extracellular matrix organization, the epithelial-mesenchymal transition, and the expression of metastasis-related cytokines. Collectively, these data showed that the overexpression of PODXL may be associated with tumor aggressiveness and that PODXL could be a diagnostic biomarker for metastatic OSCC.

Induction of ROS-independent JNK-activation-mediated apoptosis by a novel coumarin-derivative, DMAC, in human colon cancer cells

In this study, we investigated the antitumor activity of a novel coumarin derivative, 5,7-dihydroxy-4-methyl-6-(3-methylbutanoyl)-coumarin (DMAC), on colorectal carcinoma. DMAC treatment resulted in substantial proapoptotic activity against colon cancer HCT116 and LoVo cells. Induction of apoptotic characteristics, including cellular shrinkage, chromatin condensation, and Annexin V detection, was observed following DMAC treatment. Mechanistically, we observed that DMAC elicited induction of proteolytic cascade activation including cleavage of caspase-3 and poly ADP-ribose polymerase (PARP) expression and loss of the antiapoptotic proteins, Mcl-1 and Bcl-XL, accompanied by an increase in expression of the proapoptotic protein, Bak. In addition, suppressing c-Jun N-terminal protein kinase (JNK), but not extracellular-regulated protein kinase (ERK) or p38, substantially diminished DMAC-induced cell death and caspase-3 and PARP cleavage. However, pretreatment with antioxidants, including N-acetyl-l-cysteine (NAC) and diphenylene iodonium (DPI), failed to protect against DMAC-elicited apoptosis. Pretreatment with the JNK inhibitor, SP600125, suppressed DMAC-induced JNK phosphorylation, which was accompanied by a reversal of Bcl-XL expression. Moreover, combining DMAC treatment with the conventional anticancer drugs, 5-FU and CPT-11, considerably enhanced their therapeutic efficacies. Structural-activity relationship analyses further revealed that an alkylation substitution at position 6 of the coumarin ring was critical for inducing apoptosis, and the phenyl group at position 4 might have enhanced its bioactivity. Our data showed that DMAC can be used as part of a promising strategy to enhance therapeutic efficacies, and could be used to develop an approach for structure-based drug design for cancer treatment.

The efficacy of shock wave therapy in patients with knee osteoarthritis and popliteal cyamella

This randomized, controlled study was performed to compare the effects of extracorporeal shockwave therapy (ESWT) and ultrasound on the rehabilitation of knee osteoarthritis with popliteal cyamella. One hundred and twenty patients with bilateral moderate knee osteoarthritis (Altman III) and popliteal cyamella were selected and randomly assigned to four groups (GI-GIV). Patients in Groups I-III received isokinetic muscular strengthening exercises three times weekly for 8 weeks. Group II received pulse ultrasound treatment for popliteal cyamella three times weekly for 8 weeks, Group III received weekly shock wave therapy for popliteal cyamella for the first 6 weeks, and Group IV acted as controls. The therapeutic effects were evaluated by changes in the arthritic knees range of motion (ROM), visual analogue scale, Lequesne's index, and muscle peak torques after treatment and at follow-up 6 months later. Each treated group exhibited increased muscle peak torques and significantly reduced pain and disability after treatment and at follow-ups. However, only patients in Groups II and III showed significant improvements in ROM after treatment, and only participants in Group III showed immediate improvement in ROM after each treatment. Patients in Group III also showed the greatest increase in muscular strength and the greatest decrease in disability after treatment and at the follow-ups. ESWT is better than pulse ultrasound in rehabilitation of patients with knee osteoarthritis and popliteal cyamella results in more functional improvements.

TAp63 suppress metastasis via miR-133b in colon cancer cells

BACKGROUND

TAp63 is a tumour-suppressor protein that is often underexpressed in various types of cancer. It has been shown to activate gene transcription depending on the transcription domain and to be closely related with metastasis. In this study, we demonstrate that TAp63 suppresses metastasis in colon cancer cells through microRNA-133b.

METHODS

We evaluated the correlation of TAp63 and miR-133b with HT-29 and SW-620 cells and investigated the roles of TAp63 in the expression of RhoA, E-cadherin and vimentin. We further investigated the roles of TAp63-mediated invasion and migration of colon cancer cells.

RESULTS

TAp63 expression is downregulated in colon cancer, and microRNA-133b is a transcriptional target of TAp63. Furthermore, microRNA-133b is essential for the inhibitory effects of TAp63 on RhoA, E-cadherin and vimentin. Moreover, TAp63 inhibits cell migration and invasion through microRNA-133b. Correspondingly, the inhibitory effect of TAp63 on RhoA, E-cadherin, vimentin, migration and invasion can be blocked by the microRNA-133b inhibitor.

CONCLUSIONS

TAp63 and microRNA-133b were able to suppress the metastasis of colon cancer. Both TAp63 and microRNA-133b may be potential biomarkers for diagnosis in colon cancer metastasis and may provide unique therapeutic targets for this common malignancy.

Pencil drawn strain gauges and chemiresistors on paper

Pencil traces drawn on print papers are shown to function as strain gauges and chemiresistors. Regular graphite/clay pencils can leave traces composed of percolated networks of fine graphite powders, which exhibit reversible resistance changes upon compressive or tensile deflections. Flexible toy pencils can leave traces that are essentially thin films of graphite/polymer composites, which show reversible changes in resistance upon exposure to volatile organic compounds due to absorption/desorption induced swelling/recovery of the polymer binders. Pencil-on-paper devices are low-cost, extremely simple and rapid to fabricate. They are light, flexible, portable, disposable, and do not generate potentially negative environmental impact during processing and device fabrication. One can envision many other types of pencil drawn paper electronic devices that can take on a great variety of form factors. Hand drawn devices could be useful in resource-limited or emergency situations. They could also lead to new applications integrating art and electronics.

Limits on spin-independent couplings of WIMP dark matter with a p-type point-contact germanium detector

We report new limits on a spin-independent weakly interacting massive particle (WIMP)-nucleon interaction cross section using 39.5 kg days of data taken with a p-type point-contact germanium detector of 840 g fiducial mass at the Kuo-Sheng Reactor Neutrino Laboratory. Crucial to this study is the understanding of the selection procedures and, in particular, the bulk-surface events differentiation at the sub-keV range. The signal-retaining and background-rejecting efficiencies were measured with calibration gamma sources and a novel n-type point-contact germanium detector. Part of the parameter space in the cross section versus WIMP-mass implied by various experiments is probed and excluded.

CHC promotes tumor growth and angiogenesis through regulation of HIF-1α and VEGF signaling

Pancreatic adenocarcinoma is an aggressive disease with a high mortality rate. In this study, we have newly generated a monoclonal antibody (mAb), Pa65-2, which specifically binds to pancreatic cancer cells and tumor blood vessels. The target protein of Pa65-2 is identified as human clathrin heavy chain (CHC). In vitro and In vivo study showed that suppression of CHC either by shRNA or by Pa65-2 inhibited tumor growth and angiogenesis. One of the key functions of CHC was to bind with the hypoxia-inducing factor (HIF)-1α protein, increasing the stability of this protein and facilitating its nuclear translocation, thereby regulating the expression of VEGF. Taken together, our findings indicate that CHC plays a role in the processes of tumorigenesis and angiogenesis. Pa65-2 antibody or CHC shRNA can potentially be used for pancreatic cancer therapy.

Effect of mild hypothermia on breast cancer cells adhesion and migration

To explore the effect of mild hypothermia (35ºC) on breast cancer cells adhesion to vascular endothelial cells, a parallel plant flow chamber was used to observe the adhesion of human breast cancer cells MDA-MB-231 to endothelial cells Eahy926 under physiological flow at 35ºC and 37ºC, as well as the role of intercellular adhesion molecule 1 (ICAM-1) in this process. Further, the effect of mild hypothermia (35ºC) on migration of MDA-MB-231 was also studied. Our results show that mild hypothermia can inhibit the adhesion of tumor cells to endothelial cells and ICAM-1 plays an important role in this process. However, mild hypothermia inhibits breast cancer cell adhesion in a way independent on the change of ICAM-1 expression under our experimental conditions. Mild hypothermia can weaken the chemotaxis of breast cancer cells while it has no obvious effect on unidirectonal migration capacity. These results suggest that mild hypothermia could be used as a potentially adjunct treatment combined with surgery to decrease tumor cell adhesion and migration.

3D-QSAR-assisted drug design: identification of a potent quinazoline-based Aurora kinase inhibitor

We describe the 3D-QSAR-assisted design of an Aurora kinase A inhibitor with improved physicochemical properties, in vitro activity, and in vivo pharmacokinetic profiles over those of the initial lead. Three different 3D-QSAR models were built and validated by using a set of 66 pyrazole (Model I) and furanopyrimidine (Model II) compounds with IC(50) values toward Aurora kinase A ranging from 33 nM to 10.5 μM. The best 3D-QSAR model, Model III, constructed with 24 training set compounds from both series, showed robustness (r(2) (CV) =0.54 and 0.52 for CoMFA and CoMSIA, respectively) and superior predictive capacity for 42 test set compounds (R(2) (pred) =0.52 and 0.67, CoMFA and CoMSIA). Superimposition of CoMFA and CoMSIA Model III over the crystal structure of Aurora kinase A suggests the potential to improve the activity of the ligands by decreasing the steric clash with Val147 and Leu139 and by increasing hydrophobic contact with Leu139 and Gly216 residues in the solvent-exposed region of the enzyme. Based on these suggestions, the rational redesign of furanopyrimidine 24 (clog P=7.41; Aurora A IC(50) =43 nM; HCT-116 IC(50) =400 nM) led to the identification of quinazoline 67 (clog P=5.28; Aurora A IC(50) =25 nM; HCT-116 IC(50) =23 nM). Rat in vivo pharmacokinetic studies showed that 67 has better systemic exposure after i.v. administration than 24, and holds potential for further development.

Potential location of a bladder tumor suppressor gene on chromosome 9q at 9q13 to 9q22.1

Allelic losses involving chromosome 9q occur in a significant percentage of bladder tumors. Experimental evidence suggests that a putative tumor suppressor gene located on this chromosome may play a role in the development of bladder cancer. The precise location of this potential tumor suppressor gene is not clear. Previous studies have targeted a large region between 9p12-13 and 9q22 or 9p12 and 9q34.1 as the likely site. To further delineate the location of this gene, we examined 49 tumors by loss of heterozygosity (LOH) analysis, using seven microsatellite polymorhpic loci spanning from 9p21 to 9q34 of the chromosome. LOH was found in at least one of the loci in 20 (41%) of the tumors examined, and the majority (12 of 17; 71%) of the losses on 9q involved large segments or the entire chromosome arm. Although many of the tumors with large losses on 9q also involved 9p21, several tumors with small losses did not involve the 9p marker. Conversely, there were tumors with 9p21 losses that did not involve the q-arm. These data agree with recent findings that distinct tumor suppressor genes associated with bladder cancer are located on separate arms of chromosome 9. Among tumors with single locus LOHs, the most common deletion was located in 9q 13-21.2, which was detected by probe D9S15. This also is the smallest area of critical loss when LOH patterns of tumors with partial or interstitial losses were examined. Results of the study therefore suggest that a potential tumor suppressor gene may reside within or near the region of 9q13-22.1.

Epithelial cell adhesion molecule regulates tumor initiation and tumorigenesis via activating reprogramming factors and epithelial-mesenchymal transition gene expression in colon cancer

Epithelial cell adhesion molecule (EpCAM) is highly expressed in epithelial-transformed neoplasia and tumor-initiated cells (TICs), but the role that EpCAM plays in the stemness properties of TICs is still unclear. Here we show that EpCAM and reprogramming factors (c-Myc, Oct4, Nanog, and Sox2) were concomitantly elevated in TICs, which were shown to have superior self-renewal, invasiveness, and tumor-initiating abilities. Elevation of EpCAM enhanced tumorsphere formation and tumor initiation. Knockdown of EpCAM inhibited the expressions of reprogramming factors and epithelial-mesenchymal transition genes, thereby suppressing tumor initiation, self-renewal, and invasiveness. In addition, EpCAM, especially intracellular domain of EpCAM (EpICD), bound to and activated the promoter of reprogramming factors. Treatment with the inhibitor of γ-secretase (DAPT) led to the blockage of the expressions of reprogramming factors and epithelial-mesenchymal transition genes, which was accompanied by the reduction of tumor self-renewal and invasion. Furthermore, the increased release of EpEX enhanced production of EpICD and regulated the expression of reprogramming factors. Together, these findings suggest that EpCAM plays an important role in regulating cancer-initiating abilities in TICs of colon cancer. This discovery can be used in the development of new strategies for cancer therapy.

Role of lipocalin 2 and its complex with matrix metalloproteinase-9 in oral cancer

OBJECTIVES

Recent evidence demonstrated that lipocalin (LCN)2 is induced in many types of human cancer, while the detection of its complex with matrix metalloproteinase (MMP)-9 is correlated with the cancer disease status. We attempted to evaluate plasma expressions of LCN2, MMP-9, and their complex (LCN2/MMP-9) during the diagnostic work-up of patients with oral squamous cell carcinoma (OSCC) and investigated their correlations with disease progression.

METHODS

In total, 195 patients with OSCC and 81 healthy controls were recruited. Expression levels of LCN2, MMP-9, and LCN2/MMP-9 were determined with immunoenzymatic assays.

RESULTS

Patients with OSCC exhibited significantly higher levels of LCN2, MMP-9, and LCN2/MMP-9 compared with healthy controls (LCN2: P < 0.001; MMP-9: P < 0.001; LCN2/MMP-9: P < 0.01). Plasma levels of LCN2, MMP-9, and LCN2/MMP-9 in patients with OSCC were significantly correlated with each other and were associated with more-advanced clinical stages (P < 0.05) and/or a larger tumor size (P < 0.05), but were not associated with positive lymph-node metastasis or distal metastasis.

CONCLUSION

Our results suggest that plasma levels of LCN2 and the LCN2/MMP-9 complex may be useful in non-invasively monitoring OSCC progression, while supporting their potential role as biomarkers of oral cancer disease status.

Survivin SNP-carcinogen interactions in oral cancer

In Taiwan, oral cancer is causally associated with environmental carcinogens. Survivin is an anti-apoptotic protein and is generally considered a marker of malignancy. The current study explored the combined effect of survivin gene polymorphisms and environmental carcinogens on the risk and clinico-pathological development of oral cancer. Five single-nucleotide polymorphisms (SNPs) of survivin genes from 439 male patients with oral cancer and 424 male control participants (who did not have cancer) were analyzed. The survivin -31GG, +9194 GG, and +9809 TT homozygotes exhibited higher risk for oral cancer compared with the corresponding ancestral genotype, after adjustment for related confounders. The survivin -31, +9194, and +9809 SNPs combined with betel quid chewing and/or tobacco consumption could robustly elevate susceptibility to oral cancer. The distribution frequency of the -31 G: +9194 A: +9809 T haplotype was significantly higher in oral cancer patients than in control participants. These results suggest that survivin gene polymorphisms and their interactions with environmental carcinogens may increase susceptibility to oral cancer in Taiwanese men.

ABBREVIATIONS

AOR, adjusted odds ratio; CI, confidence intervals; PCR, polymerase chain-reaction; SNP, single-nucleotide polymorphisms.

Ileocolorectal intussusception due to caecal hamartoma

Although 75% of intussusceptions occur within the first two years of life, they can also develop in teenage years. This is a case report of a 13-year old boy with an ileocolorectal intussusception from a large caecal hamartoma (10 x 6 x 2 cm3) adjacent to the ileocaecal valve. Partial resection of the ascending colon and terminal ileum was performed, and the pathology of the resected mass revealed a hamartoma. Ileocolorectal intussusception secondary to hamartoma represents a particularly rare event in the paediatric population. With early surgical intervention, this patient's outcome was uneventful.

A Bayesian population analysis of the development of type 2 diabetes in the offspring of diabetic parents

Disease progression of type 2 diabetes (T2D) has received considerable attention, but little is known about the disease development of T2D. The purposes of this study were to identify disease development variables (DDV) for development of T2D and to compare corresponding models for disease development. All subjects included in this study were the offspring of diabetic parents and were followed up to 25 years. Repeated fasting blood samples were collected during the follow-up. Longitudinal data of four DDVs, namely fasting blood glucose (FBG), fasting serum insulin (FSI), homeostatic model assessment of insulin resistance (HOMA-IR) and body mass index (BMI) were recorded and compared. According to the diabetes status at the end of the follow-up, the data analysis involved a progressor group of 25 subjects, and a non-progressor group of 127 subjects. The temporal changes in the four DDVs over the time course of the disease development were evaluated by a single-slope and a dual-slope population-based Bayesian model. A dual-slope model based on FBG was found to be the best disease development model. For non-progressors, the FBG baseline stayed at 69.2 [66.5, 72.1] mg/dl (Bayes estimate [95% Bayesian credible set]) and increased with age by a rate of 0.227 mg/dl [0.149, 0.3] per year. For the progressors, the FBG increase with age the same rate as non-progressors and started to have an additional increase of 2.27 [0.505, 4.52] mg/dl per year, starting 8.73 [-10.8, -6.93] years before the diagnosis of T2D. No significant longitudinal increasing or decreasing temporal pattern was found for FSI, HOMA-IR and BMI by the population-based Bayesian approach. The proposed model, which enables a quantitative, time-based evaluation of the development of T2D in this higher risk population, may be used to quantify the effect of interventions/prevention strategies such as drug treatment and lifestyle changes.

Genetic polymorphisms of the DNA repair gene MPG may be associated with susceptibility to rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease and can lead to deformities and severe disabilities, due to irreversible damage of tendons, joints, and bones. A previous study indicated that a DNA repair system was involved in the development of RA. In this study, we investigated the association of four N-methylpurine-DNA glycosylase (MPG) gene polymorphisms (rs3176364, rs710079, rs2858056, and rs2541632) with susceptibility to RA in 384 Taiwanese individuals (192 RA patients and 192 control subjects). Our data show a statistically significant difference in genotype frequency distributions at rs710079 and rs2858056 SNPs between RA patients and control groups (P = 0.040 and 0.029, respectively). Our data also indicated that individuals with the GG genotype at rs2858056 SNP may have a higher risk of developing RA. In addition, compared with the haplotype frequencies between case and control groups, individuals with the GCGC haplotype appeared to be at a greater risk of RA progression (P = 0.003, OR = 1.75; 95&percnt; CI = 1.20-1.55). Our results suggest that rs710079 and rs2858056 polymorphisms and the GCGC haplotype in the MPG gene are associated with the risk of RA progression, and thus may be used as molecular markers of RA if they are confirmed by further research.

Atorvastatin or transgenic expression of TFPI inhibits coagulation initiated by anti-nonGal IgG binding to porcine aortic endothelial cells

BACKGROUND

Intravascular thrombosis remains a barrier to successful xenotransplantation. Tissue factor (TF) expression on porcine aortic endothelial cells (PAECs), which results from their activation by xenoreactive antibodies (Abs) to Galα1,3Gal (Gal) and subsequent complement activation, plays an important role.

OBJECTIVES

The present study aimed to clarify the role of Abs directed against nonGal antigens in the activation of PAECs to express functional TF and to investigate selected methods of inhibiting TF activity.

METHODS

PAECs from wild-type (WT), α1,3-galactosyltransferase gene-knockout (GT-KO) pigs, or pigs transgenic for CD46 or tissue factor pathway inhibitor (TFPI), were incubated with naïve baboon serum (BS) or sensitized BS (with high anti-nonGal Ab levels). TF activity of PAECs was assessed.

RESULTS

Only fresh, but not heat-inactivated (HI), naïve BS activated WT PAECs to express functional TF. Similarly, PAECs from CD46 pigs were resistant to activation by naïve BS, but not to activation by fresh or HI sensitized BS. HI sensitized BS also activated GT-KO PAECs to induce TF activity. TF expression on PAECs induced by anti-nonGal Abs was inhibited if serum was pretreated with (i) an anti-IgG Fab Ab or (ii) atorvastatin, or (iii) when PAECs were transgenic for TFPI.

CONCLUSIONS

Anti-nonGal IgG Abs activated PAECs to induce TF activity through a complement-independent pathway. This implies that GT-KO pigs expressing a complement-regulatory protein may be insufficient to prevent the activation of PAECs. Genetic modification with an 'anticoagulant' gene (e.g. TFPI) or a therapeutic approach (e.g. atorvastatin) will be required to prevent coagulation dysregulation after pig-to-primate organ transplantation.

Metallothionein-1 genotypes in the risk of oral squamous cell carcinoma

BACKGROUND

We conducted an independent analysis of metallothionein 1 (MT-1) rs8052394, rs11076161, rs8052334, rs964372, rs7191779, and rs708274 in 587 individuals who were either healthy controls or subjects with oral squamous cell carcinoma (OSCC).

METHODS

All participants provided a nucleic acid sample (blood) as well as epidemiologic information on covariates or "risk factors" for OSCC, including tobacco, alcohol, and areca quid use. The genotyping result was used in a logistic regression model that examined main effects as well as statistical interactions while controlling for confounders.

RESULTS

MT-1 is involved in regulation of zinc and copper homeostasis. It also is a potent antioxidant and its polymorphisms correlate with the risk for OSCC. Rs11076161 A, rs964372 C, and rs7191779 C alleles were protective against OSCC (adjusted OR = 0.53, 0.49, 0.36, respectively; p < 0.05), whereas rs8052394 A alleles were associated with increased risk. Areca quid chewing and tobacco use were strong risk factors for developing the disease and were associated with 20- and 8-fold increases in adjusted risk (p < 0.05), respectively.

CONCLUSIONS

Controlling for the effects of age, gender, areca quid, tobacco, and alcohol use, individuals with inherited the MT-1 rs11076161 AA, rs964372 CC, and rs7191779 GC genotypes may experience significant protection against OSCC, whereas individuals carrying the MT-1 rs8052394 A allele seem exposed to higher risk.

C-reactive protein as an outcome predictor for percutaneous transluminal angioplasty in diabetic patients with peripheral arterial disease and infected foot ulcers

AIM

Although percutaneous transluminal angioplasty (PTA) is an effective therapeutic procedure for critical limb ischemia, several clinical factors can influence the outcome of PTA for peripheral arterial disease (PAD). The aim of this study is to identify the outcome predictors of PTA in infected diabetic foot patients with PAD.

METHODS

Eighty-five diabetic patients with a total of 90 infected limbs treated by PTA participated in this study. Patients were initially admitted for infected foot ulcers and were later diagnosed with PAD. Even though all patients underwent successful PTA within 15 days of admission, limb salvage was successful in 66 cases while 24 underwent subsequent amputation. The clinical characteristics and laboratory variables of both groups before PTA were compared and analyzed.

RESULTS

Significantly higher level of C-reactive protein (CRP) was observed in the major amputation group before PTA. The cutoff value via receiver operating characteristic curve was 50mg/L (81.8% specificity, 70.7% sensitivity). Multivariate logistic regression analysis revealed that CRP levels may serve as valuable marker in determining a successful outcome.

CONCLUSION

Reduced CRP levels (<50mg/L), which indicates a low infection severity, may serve as a major predictor of successful PTA outcome in diabetic patients with infected foot ulcers.

12-O-tetradecanoylphorbol-13-acetate-induced invasion/migration of glioblastoma cells through activating PKCalpha/ERK/NF-kappaB-dependent MMP-9 expression

An increase in MMP-9 gene expression and enzyme activity with stimulating the migration of GBM8401 glioma cells via wound healing assay by 12-O-tetradecanoylphorbol-13-acetate (TPA) was detected in glioblastoma cells GBM8401. TPA-induced translocation of protein kinase C (PKC)alpha from the cytosol to membranes, and migration of GBM8401 elicited by TPA was suppressed by adding the PKCalpha inhibitors, GF109203X and H7. Activation of extracellular signal-regulated kinase (ERK) and c-Jun-N-terminal kinase (JNK) by TPA was identified, and TPA-induced migration and MMP-9 activity was significantly blocked by ERK inhibitor PD98059 and U0126, but not JNK inhibitor SP600125. Activation of NF-kappaB protein p65 nuclear translocation and IkappaBalpha protein phosphorylation with increased NF-kappaB-directed luciferase activity by TPA were observed, and these were blocked by the PD98059 and IkB inhibitor BAY117082 accompanied by reducing migration and MMP-9 activity induced by TPA in GBM8401 cells. Transfection of GBM8401 cells with PKCalpha siRNA specifically reduced PKCalpha protein expression with blocking TPA-induced MMP-9 activation and migration. Additionally, suppression of TPA-induced PKCalpha/ERK/NK-kappaB activation, migration, and MMP-9 activation by flavonoids including kaempferol (Kae; 3,5,7,4'-tetrahydroxyflavone), luteolin (Lut; 5,7,3'4'-tetrahydroxyflavone), and wogonin (Wog; 5,7-dihydroxy-8-methoxyflavone) was demonstrated, and structure-activity relationship (SAR) studies showed that hydroxyl (OH) groups at C4' and C8 are critical for flavonoids' action against MMP-9 enzyme activation and migration/invasion of glioblastoma cells elicited by TPA. Application of flavonoids to prevent the migration/invasion of glioblastoma cells through blocking PKCalpha/ERK/NF-kappaB activation is first demonstrated herein.

Reciprocal activation of macrophages and breast carcinoma cells by nitric oxide and colony-stimulating factor-1

Induction of inducible nitric oxide synthase (iNOS) gene expression, nitric oxide (NO) production and migration of RAW264.7 macrophages by coculture with breast cancer MDA-MB-231 cells or the addition of conditioned medium derived from MDA-MB-231 cells (MDA-CM) was identified. Increased iNOS/NO induction and migration of macrophages by MDA-CM were significantly blocked by adding the c-Jun-N-terminal protein kinase (JNK) inhibitor, SP600125, the nuclear factor-kappa B (NF-κB) inhibitor, BAY117082 and pyrrolidine dithiocarbamic acid and a dominant-negative JNK. The addition of an NO donor, Diethylenetriamine-NONOate, significantly activated expressions of MMP-9 and VEGF-A genes in breast carcinoma MDA-MD-231 cells and invasion of MDA-MB-231 cells in coculture with RAW264.7 macrophages as determined using Transwell systems, but that was inhibited by adding SP600125, BAY117082 and the nitric oxide synthase inhibitor, NG-nitro-L-arginine methyl ester. Induction of heme oxygenase-1 in macrophages reduced MDA-CM-induced iNOS/NO, JNK and NF-κB activations in accordance with inhibiting VEGF-A and MMP-9 gene expressions by MDA-MB-231 cells via Transwell assays. Furthermore, VEGF, sRANKL, TNF-α, IL-1α, TGF-β, CSF-1 and MCP-1 were applied, and CSF-1 showed the most potent stimulation of iNOS/NO production and migration of macrophages. MCF-7 cells with lower CSF-1 expression than MDA-MB-231 cells showed a poor stimulatory effect on iNOS/NO production and migration of macrophages. Neutralization of CSF-1 in MDA-CM using CSF-1 antibody inhibited MDA-CM-induced iNOS protein expression and migration of macrophages, and CSF-1-induced iNOS protein and migration was blocked by adding JNK inhibitor SP and NF-κB inhibitor BAY. The reciprocal activation of breast cancer and macrophages via NO-CSF-1 is first elucidated herein.

Atorvastatin or transgenic expression of TFPI inhibits coagulation initiated by anti-nonGal IgG binding to porcine aortic endothelial cells

BACKGROUND

Intravascular thrombosis remains a barrier to successful xenotransplantation. Tissue factor (TF) expression on porcine aortic endothelial cells (PAECs), which results from their activation by xenoreactive antibodies (Abs) to Galα1,3Gal (Gal) and subsequent complement activation, plays an important role.

OBJECTIVES

The present study aimed to clarify the role of Abs directed against nonGal antigens in the activation of PAECs to express functional TF and to investigate selected methods of inhibiting TF activity.

METHODS

PAECs from wild-type (WT), α1,3-galactosyltransferase gene-knockout (GT-KO) pigs, or pigs transgenic for CD46 or tissue factor pathway inhibitor (TFPI), were incubated with naïve baboon serum (BS) or sensitized BS (with high anti-nonGal Ab levels). TF activity of PAECs was assessed.

RESULTS

Only fresh, but not heat-inactivated (HI), naïve BS activated WT PAECs to express functional TF. Similarly, PAECs from CD46 pigs were resistant to activation by naïve BS, but not to activation by fresh or HI sensitized BS. HI sensitized BS also activated GT-KO PAECs to induce TF activity. TF expression on PAECs induced by anti-nonGal Abs was inhibited if serum was pretreated with (i) an anti-IgG Fab Ab or (ii) atorvastatin, or (iii) when PAECs were transgenic for TFPI.

CONCLUSIONS

Anti-nonGal IgG Abs activated PAECs to induce TF activity through a complement-independent pathway. This implies that GT-KO pigs expressing a complement-regulatory protein may be insufficient to prevent the activation of PAECs. Genetic modification with an 'anticoagulant' gene (e.g. TFPI) or a therapeutic approach (e.g. atorvastatin) will be required to prevent coagulation dysregulation after pig-to-primate organ transplantation.

Fast-forwarding hit to lead: aurora and epidermal growth factor receptor kinase inhibitor lead identification

A focused library of furanopyrimidine (350 compounds) was rapidly synthesized in parallel reactors and in situ screened for Aurora and epidermal growth factor receptor (EGFR) kinase activity, leading to the identification of some interesting hits. On the basis of structural biology observations, the hit 1a was modified to better fit the back pocket, producing the potent Aurora inhibitor 3 with submicromolar antiproliferative activity in HCT-116 colon cancer cell line. On the basis of docking studies with EGFR hit 1s, introduction of acrylamide Michael acceptor group led to 8, which inhibited both the wild and mutant EGFR kinase and also showed antiproliferative activity in HCC827 lung cancer cell line. Furthermore, the X-ray cocrystal study of 3 and 8 in complex with Aurora and EGFR, respectively, confirmed their hypothesized binding modes. Library construction, in situ screening, and structure-based drug design (SBDD) strategy described here could be applied for the lead identification of other kinases.

Preparation of N,O-carboxymethyl chitosan nanoparticles as an insulin carrier

The aim of this research was to develop pH-sensitive insulin-loaded NOCC (N,O-carboxymethyl chitosan) nanoparticles for the controlled release of insulin via the oral route. Thus, in this study, insulin-loaded NOCC nanoparticles were prepared by ionic gelation of NOCC with TPP (tripolyphosphate). NOCC nanoparticles were formed at conditions of 2 mg/ml of NOCC and 1 mg/ml of TPP. It was found that the encapsulation efficiency and process yield decreased with increasing NOCC to TPP weight ratio. Furthermore, the cumulative release of insulin from insulin-loaded NOCC nanoparticles decreased with decreasing NOCC-to-TPP weight ratio, but it increased with decreasing the initial concentration of insulin. The higher the pH of the phosphate buffered saline, the greater the amount of cumulative release of insulin-loaded NOCC nanoparticles, and thus they could protect insulin from acid.

Effect of cranberry extracts on lipid profiles in subjects with Type 2 diabetes

AIM

To examine the effect of cranberry ingestion on lipid profiles in Type 2 diabetic patients taking oral glucose-lowering drugs.

METHODS

Thirty Type 2 diabetic subjects (16 males and 14 females; mean age 65 +/- 1 years) who were taking oral glucose-lowering medication regularly were enrolled in this randomized, placebo-controlled, double-blind study. Changes in lipid profiles, oxidized low-density lipoprotein (ox-LDL), glycaemic control, components of the metabolic syndrome, C-reactive protein (CRP) and urinary albumin excretion (UAE) were assessed after cranberry or placebo treatment for 12 weeks.

RESULTS

Low-density lipoprotein (LDL) cholesterol decreased significantly in the cranberry group (from 3.3 +/- 0.2 to 2.9 +/- 0.2 mmol/l, P = 0.005) and the decrease was significantly greater than that in the placebo group (-0.4 +/- 0.1 vs. 0.2 +/- 0.1 mmol/l, P < 0.001). Total cholesterol and total : high-density lipoprotein (HDL) cholesterol ratio also decreased significantly (P = 0.020 and 0.044, respectively) in the cranberry group and the reductions were significantly different from those in the placebo group (P < 0.001 and P = 0.032, respectively). However, ox-LDL levels did not change significantly in response to cranberry consumption. Neither fasting glucose nor glycated haemoglobin improved in either group. Changes in components of the metabolic syndrome, UAE and CRP were not significantly different between groups.

CONCLUSIONS

Cranberry supplements are effective in reducing atherosclerotic cholesterol profiles, including LDL cholesterol and total cholesterol levels, as well as total : HDL cholesterol ratio, and have a neutral effect on glycaemic control in Type 2 diabetic subjects taking oral glucose-lowering agents.

Hydrogel-Coated Streptavidin Piezoelectric Biosensors and Applications to Selective Detection of Strep-Tag Displaying Cells

Two different hydrogel-coated streptavidin (SAv) piezoelectric chips were investigated. One was directly prepared by immobilizing SAv molecules covalently onto a dextran-modified crystal, and the other one was indirectly prepared by physically adsorbing SAv onto a biotin-linked dextran surface. The covalent preparation yielded 80% more SAv-binding and better subsequent adsorption of biotinylated bovine serum albumin (bBSA). Both chips displayed the best binding affinity with bBSA at pH 5.0 in a flow injection analysis and exhibited reproductive real-time response during layer-by-layer assembly of a bBSA and SAv multilayer film. In the multilayer assembly, approximately 3-7 SAv molecules were captured by each immobilized bBSA, and the estimated apparent KD values of the binding of flowing bBSA with surface SAv were 0.24 and 0.11 microM in the first two cycles of the covalently prepared chip, respectively. Two Escherichia coli cells, each flagellum-displaying Strep-tag I and Strep-tag II, respectively, were selectively detected by both kinds of SAv chips. These studies suggest the potential application of both chips in real-time screening SAv affinity ligands from a cell-display random peptide library.

Heme oxygenase-1 inhibits breast cancer invasion via suppressing the expression of matrix metalloproteinase-9

In the present study, we investigated the antitumor effects of the invasiveness and migration of heme oxygenase 1 (HO-1) in human breast carcinoma cells. 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced matrix metalloproteinase-9 (MMP-9) enzyme activity and gene expression at both protein and mRNA levels were examined in human breast carcinoma cells (MCF-7 and MDA-MB-231), and the addition of the MMP-9 inhibitor, SB3CT, significantly suppressed TPA-induced invasion and migration according to the in vitro Transwell assay. Elevation of HO-1 gene expression by ferric protoporphyrin IX inhibited TPA-induced invasion of MCF-7 cells, which was blocked by adding the heme oxygenase inhibitor, tin protoporphyrin IX, or transfection of cells with HO-1 short hairpin RNA. MCF-7 cells overexpressing HO-1 (MCF-7/HO-1) were established in the present study, and TPA-induced MMP-9 gene expression, tumor invasion, and colony formation were significantly reduced in MCF-7/HO-1 cells, compared with those in Neo-transfected cells. Activation of protein kinase Calpha/extracellular signal-regulated kinases/AP-1 with stimulation of reactive oxygen species production was involved in TPA-induced invasion of MCF-7 cells, which was attenuated by HO-1 protein induced by ferric protoporphyrin IX or transfection of HO-1 expression vectors. Additionally, the addition of carbon monoxide, but not ferric ions, biliverdin, or bilirubin, inhibited TPA-induced invasion through suppressing MMP-9, extracellular signal-regulated kinases, and AP-1 activation stimulated by TPA. The beneficial role of HO-1 in blocking tumor invasion was first identified in this study.

Effect of bradykinin metabolism inhibitors on evoked hypotension in rats: rank efficacy of enzymes associated with bradykinin-mediated angioedema

BACKGROUND AND PURPOSE

Inhibition of bradykinin metabolizing enzymes (BMEs) can cause acute angioedema, as demonstrated in a recent clinical trial in patients administered the antihypertensive, omapatrilat. However, the relative contribution of specific BMEs to this effect is unclear and confounded by the lack of a predictive pre-clinical model of angioedema.

EXPERIMENTAL APPROACH

Rats were instrumented to record blood pressure and heart rate; inhibitors were infused for 35 min and bradykinin was infused during the last 5 min to elicit hypotension, as a functional marker of circulating bradykinin and relative angioedema risk.

KEY RESULTS

In the presence of omapatrilat bradykinin produced dose-dependent hypotension, an effect abolished by B(2) blockade. In the presence of lisinopril (ACE inhibitor), but not candoxatril (NEP inhibitor) or apstatin (APP inhibitor), bradykinin also elicited hypotension. Lisinopril-mediated hypotension was unchanged with concomitant blockade of NEP or NEP/DPPIV (candoxatril+A-899301). However, hypotension was enhanced upon concomitant blockade of APP and further intensified in the presence of NEP inhibition to values not different from omapatrilat alone.

CONCLUSIONS AND IMPLICATIONS

We demonstrated that bradykinin is degraded in vivo with an enzyme rank-efficacy of ACE>APP>>NEP or DPPIV. These results suggest the effects of omapatrilat are mediated by inhibition of three BMEs, ACE/APP/NEP. However, dual inhibition of ACE/NEP or ACE/NEP/DPPIV elicits no increased risk of angioedema compared to ACE inhibition alone. Thus, novel BME inhibitors must display no activity against APP to avoid angioedema risk due to high prevalence of ACE inhibitor therapy in patients with diabetes and cardiovascular disease.

Gossypol reduction of tumor growth through ROS-dependent mitochondria pathway in human colorectal carcinoma cells

Among 13 different cell lines, gossypol (GOS) showed the most potent cytotoxic effect against human colorectal carcinoma cells including HT29, COLO205, COLO320HSR and COLO320DM cells according to an MTT assay. The cytotoxic effect of GOS was mediated by its induction of apoptosis as characterized by the occurrence of DNA ladders, apoptotic bodies and chromosome condensation in both COLO205 and HT29 cells. Activation of caspase 3, 6, 8 and 9, but not caspase 1, accompanied by the appearance of cleaved fragments of PARP (85 kDa), and caspase 3 (p17/p15), was identified in GOS-treated cells. Decreases in Bcl-xL and phosphorylated Bad proteins were found in GOS-treated cells. GOS induction of ROS production was detected by in vitro plasmid digestion, and an increase in the intracellular peroxide level was observed in GOS-treated COLO205 cells by the DCHF-DA assay. Antioxidants including N-acetyl-L-cysteine (NAC), catalase (CAT), tempol (TEM) and melatonin (MEL), but not allopurinol (ALL), pyrrolidine dithiocarbamate (PDTC) or diphenylene iodonium (DPI), significantly inhibited GOS-induced Reactive oxygen species (ROS) production through blocking the occurrence of apoptosis. GOS induced mitochondrial dysfunction characterized by a loss of the mitochondria membrane potential via DiOC6 staining, and the release of cytochrome c (Cyt c) and apoptosis-inducing factor (AIF) from mitochondria to the cytoplasm was observed. Removing mitochondria by ethidium bromide (EtBr) treatment significantly reduced the apoptotic effect of GOS in COLO205 cells. Furthermore, an intraperitoneal injection of GOS or gossypol acetic acid (GAA) significantly reduced the growth of colorectal carcinoma induced by a subcutaneous injection of COLO205 cells in nude mice. Results of the present study provide the first evidences demonstrating the in vitro and in vivo antitumor effects of GOS via an ROS-dependent mitochondrial apoptosis in colorectal carcinoma.

IGF-I plus E2 induces proliferation via activation of ROS-dependent ERKs and JNKs in human breast carcinoma cells

Induction of 17beta-estradiol (E2) and insulin-like growth factor-I (IGF-I) has been detected in breast carcinoma, however the interaction between E2 and IGF-I in the proliferation of breast carcinoma cells is still unclear. In the present study, we found that IGF-I enhances the E2-induced proliferation in MCF-7 human breast carcinoma cells in accordance with stimulation of colony formation via a soft agar assay. Activation of insulin receptor substrate-1 (IRS-1) protein and extracellular signal-related kinases (ERKs) and c-Jun N-terminal kinases (JNKs), but not p38 mitogen-activated protein kinase (MAPK), via phosphorylation induction was detected in MCF-7 cells treated with IGF-I plus E2 (E2/IGF-I). E2/IGF-I-induced proliferation was blocked by chemical inhibitors of ERKs (PD98059) and JNKs (SP600125). An increase in the expression of c-Jun protein was detected in E2/IGF-I-treated MCF-7 cells, and this was inhibited by PD98059 and SP600125. Transfection of the dominant negative MEKK and JNK plasmids significantly reduced E2/IGF-I-induced proliferation with suppression of c-Jun protein expression. An increase in peroxide production was detected in E2/IGF-I-treated cells, and N-acetyl-L-cysteine (NAC) and Tiron (TIR) addition significantly inhibited E2/IGF-I-induced cell proliferation with blocking of the phosphorylation of ERKs and JNKs, and the expression of c-Jun protein. Additionally, 3-OH flavone, baicalein, and quercetin showed effective inhibitory activities against E2/IGF-I-induced proliferation through suppressing proliferative events such as phosphorylation of IRS-1, ERKs, and JNKs proteins, and induction of c-Jun protein and colony formation. These results indicate that IGF-I interacts with E2 to promote the proliferation of breast carcinoma cells via ROS-dependent MAPK activation and c-Jun protein expression. The structure-related inhibition of E2/IGF-I-induced proliferative events by flavonoids is elucidated.

Wogonin but not Nor-wogonin inhibits lipopolysaccharide and lipoteichoic acid-induced iNOS gene expression and NO production in macrophages

Wogonin (Wog; 5,7-dihydroxy-8-methoxy flavone) has been shown to effectively inhibit lipopolysaccharide (LPS)-induced inducible nitric oxide synthase (iNOS) gene expression and nitric oxide production in our previous study. In the present study, we found that Nor-wogonin (N-Wog; 5,7,8-trihydroxyl flavone), a structural analogue of Wog with an OH substitution at C8, performed different effect on LPS- or lipoteichoic acid (LTA)-induced iNOS gene expression and nitric oxide (NO) production in macrophages. Wog, but not N-Wog, significantly inhibits LPS- or LTA-induced NO production through suppressing iNOS gene expression at both protein and mRNA without affecting NO donor sodium nitroprusside-induced NO production, NOS enzyme activity, and cells viability. Activation of JNKs (not ERKs) via phosphorylation induction, and an increase in c-Jun (not c-Fos) protein expression were involved in LPS- and LTA-treated RAW264.7 cells, and those events were blocked by Wog, but not N-Wog, addition. Furthermore, 5,7-diOH flavone, but not 5-OH flavone, 7-OH flavone, 5-OH-7-OCH(3) flavone, significantly inhibits LPS-induced iNOS protein expression and NO production, and 7,8-diOCH(3) flavone performs more effective inhibitory activity on LPS-induced NO production and iNOS protein expression than 7-OCH(3)-8-OH flavone. These data suggest that OHs at both C5 and C7 are essential for NO inhibition of flavonoids, and OCH(3) at C8 may contribute to this activity, and suppression of JNKs-c-Jun activation is involved.

Baicalein inhibition of hydrogen peroxide-induced apoptosis via ROS-dependent heme oxygenase 1 gene expression

In the present study, baicalein (BE) but not its glycoside, baicalin (BI), induced heme oxygenase-1 (HO-1) gene expression at both the mRNA and protein levels, and the BE-induced HO-1 protein was blocked by adding cycloheximide (CHX) or actinomycin D (Act D). Activation of ERK, but not JNK or p38, proteins via induction of phosphorylation in accordance with increasing intracellular peroxide levels was detected in BE-treated RAW264.7 macrophages. The addition of the ERK inhibitor, PD98059, (but not the p38 inhibitor, SB203580, or the JNK inhibitor, SP600125) and the chemical antioxidant, N-acetyl cysteine (NAC), significantly reduced BE-induced HO-1 protein expression by respectively blocking ERK protein phosphorylation and intracellular peroxide production. Additionally, BE but not BI effectively protected RAW264.7 cells from hydrogen peroxide (H(2)O(2))-induced cytotoxicity, and the preventive effect was attenuated by the addition of the HO inhibitor, SnPP, and the ERK inhibitor, PD98059. H(2)O(2)-induced apoptotic events including hypodiploid cells, DNA fragmentation, activation of caspase 3 enzyme activity, and a loss in the mitochondrial membrane potential with the concomitant release of cytochrome c from mitochondria to the cytosol were suppressed by the addition of BE but not BI. Blocking HO-1 protein expression by the HO-1 antisense oligonucleotide attenuated the protective effect of BE against H(2)O(2)-induced apoptosis by suppressing HO-1 gene expression in macrophages. Overexpression of the HO-1 protein inhibited H(2)O(2)-induced apoptotic events such as DNA fragmentation and hypodiploid cells by reducing intracellular peroxide production induced by H(2)O(2), compared with those events in neo-control (neo-RAW264.7) cells. In addition, CO, but not bilirubin and biliverdin, addition inhibits H(2)O(2)-induced cytotoxicity in macrophages. It suggests that CO can be responsible for the protective effect associated with HO-1 overexpression. The notion of induction of HO-1 gene expression through a ROS-dependent manner suppressing H(2)O(2)-induced cell death is identified in the present study.

Influence of solution acidity and CaCl2 concentration on the removal of heavy metals from metal-contaminated rice soils

Soil washing is considered a useful technique for remediating metal-contaminated soils. This study examined the release edges of Cd, Zn, Ni, Cr, Cu or Pb in two contaminated rice soils from central Taiwan. The concentrations exceeding the trigger levels established by the regulatory agency of Taiwan were Cu, Zn, Ni and Cr for the Ho-Mei soil and Pb for the Nan-Tou soil. Successive extractions with HCl ranging from 0 to 0.2 M showed increased release of the heavy metals with declining pH, and the threshold pH value below which a sharp increase in the releases of the heavy metals was highest for Cd, Zn, and Ni (pH 4.6 to 4.9), intermediate for Pb and Cu (3.1 to 3.8) and lowest for Fe (2.1), Al (2.2) and Cr (1.7) for the soils. The low response slope of Ni and Cr particularly for the rice soils make soil washing with the acid up to the highest concentration used ineffective to reduce their concentrations to below trigger levels. Although soil washing with 0.1 M HCl was moderately effective in reducing Cu, Pb, Zn and Cd, which brought pH of the soils to 1.1+/-0.1 (S.D.), the concurrent release of large quantities of Fe and Al make this remediation technique undesirable for the rice soils containing high clay. Successive washings with 0.01 M HCl could be considered an alternative as the dissolution of Fe and Al was minimal, and between 46 to 64% of Cd, Zn, and Cu for the Ho-Mei soil and 45% of Pb in the Na-Tou soil were extracted after four successive extractions with this dilute acid solution. The efficacy of Cd extraction improved if CaCl2 was added to the acid solution. The correlation analysis revealed that Cr extracted was highly correlated (P < 0.001) with Fe extracted, whereas the Cu, Ni, Zn, Cd or Pb extracted was better correlated (P < 0.001) with Al than with Fe extracted. It is possible that the past seasonal soil flooding and drainage in the soils for rice production was conducive to incorporating Cr within the structure of Fe oxide, thereby making them extremely insoluble even in 0.2 M HCl solution. The formation of solid solution of Ni with Al oxide was also possible, making it far less extractable than Cd, Zn, Cu, or Pb with the acid concentrations used.

Quercetin inhibition of ROS-dependent and -independent apoptosis in rat glioma C6 cells

In the present study, we investigated the protective mechanism of quercetin (QUE) and its glycosides, rutin (RUT) and quercitrin (QUI), on reactive oxygen species (ROS)-dependent (H(2)O(2)) and -independent (chemical anoxia) cell death in rat glioma C6 cells. Induction of HO-1 protein expression was detected in QUE- but not RUT- or QUI-treated C6 cells, and this was prevented by cycloheximide and actinomycin D. Incubation of C6 cells with QUE, but not RUT or QUI, protected C6 cells from H(2)O(2)- and chemical anoxia-induced cytotoxicity according to the MTT and LDH release assays. Apoptotic characteristics including chromatin condensation, DNA ladders, and hypodiploid cells appeared in H(2)O(2)-and chemical anoxia-treated C6 cells, and those events were significantly suppressed by adding QUE (but not RUT or QUI). Increases in caspase 3, 8, and 9 enzyme activities with decreases in pro-PARP and pro-caspase 3 protein levels and an increase in cleaved D4-GDI protein were identified in H(2)O(2)-and chemical anoxia-treated C6 cells, and these were blocked by the addition of QUE, but not by RUT or QUI. Intracellular peroxide levels increased with H(2)O(2) and decreased with chemical anoxia, and the addition of QUE reduced the intracellular peroxide levels induced by H(2)O(2). Results of an anti-DPPH radical assay showed that QUE, RUT, and QUI dose-dependently inhibited the production of DPPH radicals in vitro; however, QUE (but not RUT or QUI) prevention of DNA damage induced by OH radicals was identified with a plasmid digestion assay. Increases in phosphorylated ERK and p53 protein expressions were detected in H(2)O(2)- but not chemical anoxia-treated C6 cells, and the addition of QUE significantly blocked H(2)O(2)-induced phosphorylated ERK and p53 protein expressions. Adding the HO-1 inhibitors, SnPP, CoPP, and ZnPP, reversed the protective effect of QUE against H(2)O(2)- and chemical anoxia-induced cell death according to the MTT assay and morphological observations. Additionally, QUE exhibited inhibitory effects on LPS/TPA-induced transformation in accordance with a decrease in MMP-9 enzyme activity and iNOS protein expression in C6 cells. Taken together, the results of this study suggest that QUE exhibits an inhibitory effect on both ROS-dependent and -independent cell death, and induction of HO-1 protein expression is involved.

Baicalein inhibition of oxidative-stress-induced apoptosis via modulation of ERKs activation and induction of HO-1 gene expression in rat glioma cells C6

In the present study, we examined the protective mechanism of baicalein (BE) and its glycoside, baicalin (BI), on hydrogen-peroxide (H(2)O(2))-induced cell death in rat glioma C6 cells. Results of the MTT assay, LDH release assay, and morphological observation showed that H(2)O(2) addition reduced the viability of C6 cells, and this was prevented by the addition of BE but not BI. Incubation of C6 cells with BE significantly decreased the intracellular peroxide level induced by H(2)O(2) according to flow cytometric analysis using DCHF-DA as a fluorescent substrate. Suppression of H(2)O(2)-induced apoptotic events including DNA ladders, hypodiploid cells, and activation of caspases 3, 8, and, 9 by BE but not BI was identified in C6 cells. The cytotoxicity and phosphorylation of ERK proteins induced by H(2)O(2) were blocked by the ERK inhibitor PD98059. Catalase addition prevented H(2)O(2)-induced ROS production, ERKs protein phosphorylation, and cell death, and BE dose-dependently inhibited H(2)O(2)-induced ERK protein phosphorylation in C6 cells. These data suggest that ROS-scavenging activity is involved in BE prevention of H(2)O(2)-induced cell death via blocking ERKs activation. Additionally, BE but not BI induced heat shock protein 32 (HSP32; HO-1) protein expression in both time- and dose-dependent manners, but not heme oxygenase 2 (HO-2), heat shock protein 70 (HSP70), or heat shock protein 90 (HSP90) protein expression. In the absence of H(2)O(2), BE induces ERKs protein phosphorylation, and HO-1 protein expression induced by BE was blocked by the addition of cycloheximide, actinomycin D, and the ERK inhibitor PD98059. The addition of the HO inhibitor ZnPP inhibited the protective effect of BE against H(2)O(2)-induced cytotoxicity in C6 cells according to the MTT assay and apoptotic morphology under microscopic observation, accompanied by blocking the ROS-scavenging activity of BE in C6 cells. However, BE treatment was unable to protect C6 cells from C2-ceramide-induced cell death. These data indicate that BE possesses abilities to inhibit ROS-mediated cytotoxic effects through modulation of ERKs activation and induction of HO-1 protein expression. The role of HO-1 in ROS-scavenging activity of BE is proposed.

Lipopolysaccharide plus 12-o-tetradecanoylphorbol 13-acetate induction of migration and invasion of glioma cells in vitro and in vivo: Differential inhibitory effects of flavonoids

In an earlier study, we reported that nitric oxide is involved in lipopolysaccharide plus 12-o-tetradecanoylphorbol 13-acetate-induced malignant transformation via increases in metalloproteinase 9 enzyme activity and inducible nitric oxide synthase gene expression in rat glioma C6 cells, however the mechanism has remained undefined. Lipopolysaccharide plus 12-o-tetradecanoylphorbol 13-acetate, but not lipopolysaccharide or 12-o-tetradecanoylphorbol 13-acetate alone, induced transformation in glioma C6 cells (but not in human glioblastoma cells GBM-8401 cells) without affecting their viability. An increase in inducible nitric oxide synthase protein expression, nitric oxide production, and metalloproteinase 9 enzyme activity is identified lipopolysaccharide/12-o-tetradecanoylphorbol 13-acetate-treated C6 cells, however lipopolysaccharide/12-o-tetradecanoylphorbol 13-acetate and 12-o-tetradecanoylphorbol 13-acetate (but not lipopolysaccharide) addition shows the similar inductive pattern on metalloproteinase 9 enzyme activity without affecting inducible nitric oxide synthase protein expression and nitric oxide production in GBM-8401 cells. Treatment of C6 cells with lipopolysaccharide/12-o-tetradecanoylphorbol 13-acetate increases the expression of phosphorylated extracellular regulated protein kinases and Jun N-terminal kinases, but not p38, proteins, and an addition of the extracellular regulated protein kinases inhibitor PD98059 or Jun N-terminal kinases inhibitors SP600125, but not the p38 inhibitor SB203580, significantly blocked lipopolysaccharide/12-o-tetradecanoylphorbol 13-acetate-induced inducible nitric oxide synthase protein expression and metalloproteinase 9 enzyme activity accompanied by blocking morphological transformation in C6 cells. Among 19 structurally related flavonoids, kaempferol and wogonin exhibit significant inhibitory effects on lipopolysaccharide/12-o-tetradecanoylphorbol 13-acetate-induced morphological transformation and colony formation, and attenuation of inducible nitric oxide synthase, phosphorylated extracellular regulated protein kinases protein expression, and metalloproteinase 9 enzyme activity was observed. 2'-OH flavone at a dose of 100 microM inhibition of lipopolysaccharide/12-o-tetradecanoylphorbol 13-acetate-induced events via apoptosis induction is identified. Furthermore, lipopolysaccharide/12-o-tetradecanoylphorbol 13-acetate, but not lipopolysaccharide or 12-o-tetradecanoylphorbol 13-acetate, induces tumoral invasion and migration in vitro and in vivo, and those are blocked by kaempferol and wogonin addition. These data suggest that combination of lipopolysaccharide and 12-o-tetradecanoylphorbol 13-acetate promotes tumoral progression via activating metalloproteinase 9 enzyme activity and inducible nitric oxide synthase gene expression, which is located downstream of mitogen-activated protein kinases activation, in rat glioma cells C6. Kaempferol and wogonin exhibit effective inhibitory effects on lipopolysaccharide/12-o-tetradecanoylphorbol 13-acetate-induced events, and thus possess the potential for further development.

Performance of elbow tracking under constant torque disturbance in normotonic stroke patients and normal subjects

OBJECTIVE

In this study, the influences of externally imposed constant torque on the voluntary elbow movements of stroke and normal subjects were investigated quantitatively.

BACKGROUND

Muscle weakness, spasticity and incoordination are the major factors that interfere with stroke patient's limb functions. Imposing external torque disturbance may worsen the motor performance. This experiment was designed to investigate the effects of small constant external torque on the performance of voluntary elbow movements.

METHODS

Tracking of a ramp-and-hold angle trajectory in the direction of extension was used as the main task for performance assessment. Each subject repeated the same tracking movement six times in each of three loading conditions: no, assistive or resistive loading. Five normal and six stroke subjects were recruited for this study. We used parameters extracted from movement trajectory and processed electromyograms as the performance indicators.

RESULTS

For normal subjects, there was no difference in the tracking performance in the three loading conditions. For stroke patients, the affected side had inferior performance to the healthy side in the free loading condition and the difference diminished in assistive and resistive loading conditions as the performance of the affected side improved. Integrated electromyograms of biceps or triceps did not show significant changes in different loading conditions.

CONCLUSIONS

Small externally imposed constant torque, either resistive or assistive, may improve motor performance of affected elbows in stroke patients.

RELEVANCE

Most of the currently available prostheses are passive devices, aiming at providing better support and improving stability. The results of the current study imply that an active prosthetic device that applies a small constant torque to the hemiparetic elbow can improve its motor performance in stroke patients. The direction of external torque is to assist the weaker side of the antagonistic muscle pair.