Size Characterization of Mycobacterium bovis BCG (Bacillus Calmette Guérin) Vaccine,Tice™ Substrain

Reconstituted, lyophilized, attenuated Mycobacterium bovis, Bacillus Calmette Guérin (BCG) vaccine, Tice substrain, was characterized using a Coulter Multisizer and a HIAC/Royco counter. The primary organism has an equivalent spherical diameter approximating 1 µm but the BCG cell suspension is heavily aggregated. The cumulative size distribution of the suspension fits a log-probit plot and this information can be used to determine the total number of particles per ampoule. The instrumental count may be related to the viable count. The state of dispersion was unaffected by mild shear (syringe aspiration or ultrasound) and only slightly affected by the addition of cetylpyridinium chloride or sodium tauroglycolate.     

Lycium barbarum (Goji Berry) extracts and its taurine component inhibit PPAR-γ-dependent gene transcription in human retinal pigment epithelial cells: Possible implications for diabetic retinopathy treatment

The peroxisome proliferator activated receptor-γ (PPAR-γ) is involved in the pathogenesis of diabetic retinopathy. Diabetic retinopathy is a preventable microvascular diabetic complication that damages human retinal pigment epithelial cells. Taurine is abundant in the fruit of Lycium barbarum (Goji Berry), and is reportedly beneficial for diabetic retinopathy. However, the mechanism of its action is unknown. Hence, we have investigated the mechanism of action of an extract from L. barbarum on a model of diabetic retinopathy, the retinal ARPE-19 cell line, and identified the receptor function of taurine, an active component of L. barbarum (Goji Berry) extract, which is potentially responsible for the protective effect on diabetic retinopathy. We demonstrate for the first time that L. barbarum extract and its taurine component dose-dependently enhance PPAR-γ luciferase activity in HEK293 cell line transfected with PPAR-γ reporter gene. This activity was significantly decreased by a selective PPAR-γ antagonist GW9662. Moreover, L. barbarum extract and taurine dose-dependently enhanced the expression of PPAR-γ mRNA and protein. In an inflammation model where ARPE-19 cells were exposed to high glucose L. barbarum extract and taurine down-regulated the mRNA of pro-inflammatory mediators encoding MMP-9, fibronectin and the protein expression of COX-2 and iNOS proteins. The predicted binding mode of taurine in the PPAR-γ ligand binding site mimics key electrostatic interactions seen with known PPAR-γ agonists. We conclude that PPAR-γ activation by L. barbarum extract is associated with its taurine content and may explain at least in part its use in diabetic retinopathy progression.     

Polo-like kinase1 (Plk1) knockdown enhances cisplatin chemosensitivity via up-regulation of p73α in p53 mutant human epidermoid squamous carcinoma cells

Polo-like kinase 1 (Plk1), a critical regulator of mitotic entry, progression and exit, has been shown to be involved in a variety of cancers and thus is becoming an attractive target for cancer management. In case of DNA damage, Plk1 not only inhibits p53 independent apoptosis by dysfunctioning p73α but also allows cells to recover from growth arrest. Here, we showed the effects of knocking down plk1 gene through small interference RNA (siRNA) on cell cycle progression, proliferation and chemosensitivity of p53 mutant A431 cells to cisplatin (CDDP). The expression of Plk1 was measured by RT-PCR and Western blotting. Anti-proliferative response accompanied with cell cycle arrest in G(2)/M phase and induction of cell death was recorded following Plk1 knockdown. Furthermore, cells following knockdown of Plk1, which induced increase of Cyclin B1, p-Cdc2 and p73α with a decrease in p-Cdc25C, were more sensitive to CDDP. CDDP treatment induced nuclear translocation and co-localization of Plk1 with p73α whereas combination of CDDP and Plk1siRNA upregulated the expression of p73α protein in a synergistic manner thereby leading to an increase up to ∼5 folds in CDDP-induced cell death. The increase in caspase-3 activity indicated apoptosis as a contributor in the total cell death. Conclusively, plk1 gene silencing can enhance the sensitivity of A431 cells to low doses of CDDP by upregulating p73α expression and thus can be a revolutionary approach in cancer chemotherapy.     

Copper oxide nanoparticles induce collagen deposition via TGF-β1/Smad3 signaling in human airway epithelial cells

Use and application of nanoparticles has increased in recent years. Copper oxide nanoparticles (CuONPs) are one of the most common types of nanoparticles, and they are mainly used as catalysts and preservatives. However, limited toxicity data are available on the toxicity of CuONPs to the respiratory system. We investigated fibrotic responses induced by CuONPs in the respiratory tract and elucidated its underlying mechanism of action in vivo and in vitro experiments. In the mouse model, CuONPs exposure markedly increased transforming growth factor-β1 (TGF-β1) and collagen I expression and Smad3 phosphorylation, combined with elevation of inflammatory mediators including interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α). These alterations were also observed in histological analysis of lung tissue. CuONPs markedly increased inflammatory responses and collagen deposition, accompanied by the elevation of TGF-β1 and collagen I expression in lung tissue. In addition, CuONPs-treated H292 cells showed significantly increased mRNA and protein production of TGF-β1, collagen I, IL-6, and TNF-α; this response was markedly decreased by treatment of a TGF-β1 inhibitor (SB-431542). Taken together, CuONPs induced fibrotic responses in the respiratory tract, closely related to TGF-β1/Smad3 signaling. Therefore, our results raise the necessity of further investigation for the present state of its risk by providing useful information of the toxicity of CuONPs.     

Regulation of cigarette smoke-induced mucin expression by neuregulin1β/ErbB3 signalling in human airway epithelial cells

Mucus hypersecretion is an important manifestation in patients with chronic obstructive pulmonary diseases (COPD). Cigarette smoke is importantly implicated in the pathogenesis of COPD. Previous studies have shown that cigarette smoke-induced MUC5AC (a major component of airway mucus) expression involving ErbB1 (EGF receptor) signalling pathway. Recently, it has been reported that cigarette smoke induces ErbB3 activation in airway epithelia to secret mucus, and the ligand of ErbB3, neuregulin (NRG) 1β, induces MU5AC expression in human bronchial epithelial cells. In the present study, we have suggested that NRG1β/ErbB3 signalling is activated by cigarette smoke, resulting in the activation of a variety of signal cascade pathways, leading to mucin production in human bronchial epithelial (16HBE) cells. We show that cigarette smoke increases NRG1β release, ErbB3 phosphorylation and MUC5AC production. These effects are prevented by an ErbB3-neutralizing antibody and by specific knockdown using small interfering RNA (siRNA) for NRG1β, implicating NRG1β-dependent ErbB3 activation in the responses. Cigarette smoke activates ERK1/2, c-Jun N-terminal kinase (JNK) mitogen-activated protein kinases (MAPKs) and phosphatidylinositol 3-kinase (PI3-K) signalling pathways, which are also inhibited by an ErbB3-neutralizing antibody and NRG1β siRNA, indicating the regulation of cigarette smoke-activated pathways by NRG1β/ErbB3 signalling. Furthermore, pre-treatments with metalloprotease inhibitor (TNF-α protease inhibitor-1) and specific knockdown of TNF-α-converting enzyme (TACE) with TACE siRNA prevented cigarette smoke-induced NRG1β release, ErbB3 phosphorylation and mucin production, suggesting the role of TACE in cigarette smoke-mediated NRG1β/ErbB3 signalling activation. These results suggest that NRG1β/ErbB3 signalling regulates cigarette smoke-induced mucin overproduction via the MAPK and PI3K signal pathways in 16HBE cells.     

22-O-(N-Boc-l-glycine) ester of renieramycin M inhibits migratory activity and suppresses epithelial–mesenchymal transition in human lung cancer cells

Journal of Natural Medicines - The incidence of metastasis stage crucially contributes to high recurrence and mortality rate in lung cancer patients. Unfortunately, no available treatment inhibits...     

The calmodulin inhibitor N-(6-aminohexyl)-5-chloro-1-naphthalene sulphonamide directly blocks human ether ��-go-go-related gene potassium channels stably expressed in human embryonic kidney 293 cells

Background and purpose:

Results from several studies point to voltage-gated Na⁺ channels as potential mediators of the immobility produced by inhaled anaesthetics. We hypothesized that the intrathecal administration of tetrodotoxin, a drug that blocks Na⁺ channels, should enhance anaesthetic potency, and that concurrent administration of veratridine, a drug that augments Na⁺ channel opening, should reverse the increase in potency.

Experimental approach:

We measured the change in isoflurane potency for reducing movement in response to a painful stimulus as defined by MAC (minimum alveolar concentration of anaesthetic required to abolish movement in 50% of subjects) caused by intrathecal infusion of various concentrations of tetrodotoxin into the lumbothoracic subarachnoid space of rats, and the change in MAC caused by the administration of a fixed dose of tetrodotoxin plus various doses of intrathecal veratridine.

Key results:

Intrathecal infusion of tetrodotoxin (0.078–0.63 µM) produced a reversible dose-related decrease in MAC, of more than 50% at the highest concentration. Intrathecal co-administration of veratridine (1.6–6.4 µM) reversed this decrease in a dose-related manner, with nearly complete reversal at the highest veratridine dose tested.

Conclusions and implications:

Intrathecal administration of tetrodotoxin increases isoflurane potency (decreases isoflurane MAC), and intrathecal administration of veratridine counteracts this effect in vivo. These findings are consistent with a role for voltage-gated Na⁺ channel blockade in the immobility produced by inhaled anaesthetics.     

Prooxidant and proinflammatory potency of air pollution particulate matter (PM₂.₅₋₀.₃) produced in rural, urban, or industrial surroundings in human bronchial epithelial cells (BEAS-2B)

Compelling evidence indicates that exposure to air pollution particulate matter (PM) affects human health. However, how PM composition interacts with PM-size to cause adverse health effects needs elucidation. In this study, we were also interested in the physicochemical characteristics and toxicological end points of PM?.???.? samples produced in rural, urban, or industrial surroundings, thereby expecting to differentiate their respective in vitro adverse health effects in human bronchial epithelial cells (BEAS-2B). Physicochemical characteristics of the three PM?.???.? samples, notably their inorganic and organic components, were closely related to their respective emission sources. Referring also to the dose/response relationships of the three PM?.???.? samples, the most toxicologically relevant exposure times (i.e., 24, 48, and 72 h) and doses (i.e., 3.75 μg PM/cm2 and 15 μg PM/cm2) to use to study the underlying mechanisms of action involved in PM-induced lung toxicity were chosen. Organic chemicals adsorbed on the three PM?.???.? samples (i.e., polycyclic aromatic hydrocarbons) were able to induce the gene expression of xenobiotic-metabolizing enzymes (i.e., Cytochrome P4501A1 and 1B1, and, to a lesser extent, NADPH-quinone oxidoreductase-1). Moreover, intracellular reactive oxygen species within BEAS-2B cells exposed to the three PM?.???.? samples induced oxidative damage (i.e., 8-hydroxy-2'-deoxyguanosine formation, malondialdehyde production and/or glutathione status alteration). There were also statistically significant increases of the gene expression and/or protein secretion of inflammatory mediators (i.e., notably IL-6 and IL-8) in BEAS-2B cells after their exposure to the three PM?.???.? samples. Taken together, the present findings indicated that oxidative damage and inflammatory response preceeded cytotoxicity in air pollution PM?.???.?-exposed BEAS-2B cells and supported the idea that PM-size, composition, and origin could interact in a complex manner to determine the in vitro responsiveness to PM.     

Chiral effects in adrenocorticolytic action of o,p′-DDD (mitotane) in human adrenal cells

1. Adrenocortical carcinoma (ACC) is a rare malignant disease with poor prognosis. The main pharmacological choice, o,p′-DDD (mitotane), produces severe adverse effects.

2. Since o,p′-DDD is a chiral molecule and stereoisomers frequently possess different pharmacokinetic and/or pharmacodynamic properties, we isolated the two o,p′-DDD enantiomers, (R)-(+)-o,p′-DDD and (S)-(–)-o,p′-DDD, and determined their absolute structures.

3. The effects of each enantiomer on cell viability and on cortisol and dehydroepiandrosterone (DHEA) secretion in the human adrenocortical cell line H295R were assessed. We also assayed the o,p′-DDD racemate and the m,p′- and p,p′-isomers.

4. The results show small but statistically significant differences in activity of the o,p′-DDD enantiomers for all parameters tested. The three DDD isomers were equally potent in decreasing cell viability, but p,p′-DDD affected hormone secretion slightly less than the o,p′- and m,p′-isomers.

5. The small chiral differences in direct effects on target cells alone do not warrant single enantiomer administration, but might reach importance in conjunction with possible stereochemical effects on pharmacokinetic processes in vivo.

     

Effects of superoxide anion on intracellular Ca~(2 ) concentration in rabbit pulmonary arterial smooth muscle cells

目的：研究超氧阴离子对兔肺动脉平滑肌细胞内钙的影响．方法：采用Ｆｕｒａ２测定酶分离的兔肺动脉平滑肌细胞内钙．结果：ＡＴＰ３０μｍｏｌ·Ｌ－１诱导平滑肌细胞内钙瞬时性增加．Ｔｈａｐｓｉｇａｒｇｉｎ引起平滑肌细胞内钙缓慢的增加．超氧阴离子作用于平滑肌细胞后，使ＡＴＰ诱导细胞内钙增加的持续相升高，在ＡＴＰ作用后５和１０ｍｉｎ的比值（Δｒａｔｉｏ５ｍｉｎ和Δｒａｔｉｏ１０ｍｉｎ）分别由００９１±００２２和００２１±００２０升高至０１４９±００４８和０１１７±００４７．但超氧阴离子对ｔｈａｐｓｉｇａｒｇｉｎ诱导的细胞内钙变化没有明显的影响．结论：超氧阴离子延迟ＡＴＰ诱导的平滑肌细胞内钙瞬时性增加，而不影响钙的泄漏途径．     

Modulation of Ecto-5′-Nucleotidase by phospholipids in human umbilical vein endothelial cells (HUVEC)

Ecto-5′-nucleotidase, the major enzyme controlling extracellular adenosine production, can be activated by phospholipids, e.g. lysophosphatidylcholine (LPC). This study examined the structural requirements of phospholipids to evoke this enzyme activation and figured out two new activators of ecto-5′-nucleotidase: platelet activating factor (PAF) and sphingosylphosphorylcholine (SPC). Potential signal transduction pathways including an involvement of protein kinase C and PAF-receptor were evaluated on the model of human umbilical vein endothelial cells (HUVEC). Cells were pre-incubated with 10 μM of various phospholipids including lysophosphatidylcholine, β-arachidonyl-γ-palmityl-α-phosphatidylcholine, β, γ-dipalmityl-α-phosphatidyl-choline, β,γ-dipalmityl-α-phosphatidylethanolamine, β,γ-dipalmityl-α-phosphatidylserine, γ-acyl-β-lyso-α-phosphatidylethanolamine, β-acetyl-γ-O-hexadecyl-α-phosphatidylcholine (platelet activating factor), lysophosphatidylic acid, sphingosine-1-phosphate and sphingosylphosphorylcholine. In the cell supernatant the extracellular dephosphorylation rate of the fluorescent AMP-analogue 1, N⁶-etheno-5′AMP to 1, N⁶-etheno-adenosine was measured by HPLC. Out of these ten structurally related phospholipids only lysophosphatidylcholine, sphingosylphosphatidylcholine and platelet activating factor dose-dependently increased the activity of ecto-5′-nucleotidase. Pharmacological blocking experiments revealed that neither the activation of PAF-receptor nor of protein kinase C were important for mediating the activation of ecto-5′-nucleotidase. Thus, using information on the known molecular structures of tested phospholipids, a phosphatidylcholine residue in α-position and a short chain length fatty acid esterified in β-position seem essential for activation of ecto-5′-nucleotidase by glycerophospholipids. Since all tested phospholipids have similar fatty acid chain lengths and residues in α-position, they should act similarly on membrane fluidity. It is concluded that the observed effects are not based on changes in membrane fluidity by the added phospholipids, but rather involve a yet to be determined phospholipid-receptor.