Sesamol inhibits UVB-induced ROS generation and subsequent oxidative damage in cultured human skin dermal fibroblasts

The exposure of cells to ultraviolet B radiation (UVB) can induce the production of reactive oxygen species (ROS) which damage cellular components. Free radical scavengers and antioxidants can interfere with the production of ROS. We studied cytotoxicity, intracellular ROS levels, lipid peroxidation, antioxidant status and oxidative DNA damage in cultured human skin dermal fibroblast adult cells (HDFa) exposed to UVB in the presence of sesamol, a natural phenolic compound. The levels of cytotoxicity, intracellular ROS, lipid peroxidation, oxidative DNA damage and apoptotic morphological changes were significantly increased in UVB irradiated HDFa cells. We also observed that the activities of enzymatic antioxidants (superoxide dismutase, catalase and glutathione peroxidase) and the levels of non-enzymatic antioxidant status (GSH) were significantly decreased in UVB irradiated cells. On the other hand, sesamol pretreatment significantly decreased cytotoxicity, intracellular ROS, lipid peroxidation, oxidative DNA damage and apoptotic morphological changes in sesamol-pretreated and UVB-irradiated HDFa cells. We have also observed increased enzymatic and non-enzymatic antioxidants status in sesamol plus UVB-irradiated cells. Among the different doses tested, 80 μM of sesamol shows maximum protection for UVB-induced oxidative damage. In conclusion, UVB-induced ROS formation, cell fatality, lipid peroxidation, antioxidant depletion and oxidative DNA damage in HDFa cells is inhibited by sesamol, which, probably through its ROS scavenging activity.     

β-Blockers Reduce Mortality in Patients Undergoing High-Risk Non-Cardiac Surgery

Background

β-Adrenergic receptor antagonists (β-blockers) are frequently used with the aim of reducing perioperative myocardial ischemia and infarction. However, randomized clinical trials specifically designed to evaluate the effects of β-blockers on mortality in patients undergoing non-cardiac surgery have yielded conflicting results.

Objective

This study aimed to examine the effect of perioperative β-blockers on total and cardiovascular mortality in patients undergoing non-cardiac surgery.

Methods

We conducted a meta-analysis of randomized clinical trials that examined the effects of β-blockers versus placebo on cardiovascular and all-cause mortality in patients undergoing non-cardiac surgery. We extracted data from articles published before 30 November 2009 in peer-reviewed journals indexed in MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL), EMBASE and CINAHL. Data extraction was carried out independently by two reviewers on the basis of an intent-to-treat approach, and inconsistencies were discussed and resolved in conference. The present meta-analysis was undertaken according to the Quality of Reporting of Meta-analyses (QUORUM) statement.

Results

A total of 2148 records were screened, from which we identified 74 randomized controlled trials for non-cardiac surgery. After excluding 49 studies that did not report the clinical outcome of interest or were subanalyses or presented duplicate data, the final search left 25 clinical trials. Treatment with β-blockers had no significant effect on all-cause mortality (odds ratio [OR] 1.15; 95% confidence interval [CI] 0.92, 1.43; p = 0.2717) or cardiovascular mortality (OR 1.13; 95% CI 0.85,1.51; p = 0.5855). However, surgical risk category markedly differed across the studies. According to Joint American College of Cardiology and American Heart Association guidelines for perioperative assessment of patients having non-cardiac surgery, five trials evaluated the effect of β-blockers in patients treated with emergency and vascular surgery (high-risk category) whereas 15 and five trials evaluated the effect of β-blockers in intermediate low and intermediate high surgical risk categories, respectively. Subgroup analyses showed that the surgical risk category and dose titration of β-blockers to target heart rate affected the estimate of the effect of β-blockers for all-cause and cardiovascular mortality. β-Blockers reduced total mortality by 61% more in patients who underwent high-risk surgery than in those who underwent intermediate high- or intermediate low-risk surgery. When cardiovascular mortality was assessed, the benefit of β-blockers was 74% greater in trials that titrated β-blockers to heart rate than in trials that did not, although formal statistical significance was not achieved.

Conclusions

These data suggest that β-blockers may be useful for reducing mortality in patients who undergo high-risk non-cardiac surgery.     

Di 2-ethyl hexyl phthalate affects differentiation and matrix mineralization of rat calvarial osteoblasts – in vitro

Di-2-ethyl hexyl phthalate (DEHP), an industrial plasticizer and a ubiquitous environmental contaminant, is an established endocrine disruptor (ED). Increasing evidences indicate that some EDs interfere with osteoblast differentiation and function. In the present study, we investigated the effects of DEHP on the expression of cell cycle proteins, differentiation markers, Runx2 and its co-activator TAZ in osteoblasts derived from neonatal rat calvaria. A significant decrease in protein levels of cyclin D1 and CDK-2 was found at high dosage of DEHP (100 μM) after 24 h treatment. DEHP treatment caused a significant decrease in ALP mRNA. While DEHP treatment significantly decreased the TAZ at mRNA and protein levels, it decreased only the Runx2protein levels. Histochemical localization of ALP, collagen and mineralized nodules studied from cells treated with DEHP (10 and 100 μM) for 21 days revealed a drastic decrease in collagen, ALP and mineralization. In conclusion, DEHP affected differentiation of neonatal rat calvarial osteoblasts and mineralization of matrix secreted by these cells.     

Catalase activity and innate immune response of Caenorhabditis elegans against the heavy metal toxin lead

The heavy metal lead‐induced oxidative stress on Caenorhabditis elegans was examined at the level of catalase activity and on innate immunity. Stress‐induced C. elegans was exposed to Pseudomonas aeruginosaPA14::GFP for monitoring the impact at the physiological level. Role of catalase on the innate‐immune responses of C. elegans was examined. PA14::GFP did not colonize lead pretreated C. elegans intestinal cells significantly compared to untreated controls, indicating stress‐mediated upregulation of host‐immunity. Semiquantitative PCR analyses of lead‐exposed and PA14‐infected C. elegans mRNA showed significant upregulation of candidate antimicrobial enzyme gene lys‐7 after 24 h of exposures. Upregulation of metallothionein(mtl‐1) when compared to mtl‐2 in response to the lead suggesting active detoxification of metal by mtl‐1. Exogenously provided Catalase (0.4–3.2 U) induced significant upregulation of lys‐7 compared to controls. lys‐7 upregulation during lead exposure was reconfirmed by real‐time PCR. Confocal microscopy and fluorescence spectrophotometer analyses indicated that the lead pretreated C. elegans was significantly less colonized by PA14::GFP when compared to controls. Relative expression of ctl‐1 and ctl‐2 mRNA was measured using real time PCR and found to be regulated during lead exposures. Over all, the upregulation of antimicrobial gene expression appears to be correlated with the level of catalase during stress emphasizing their key roles in defensive mechanism(s). These results provide a link between the stress and related immune responses which can be explored in higher systems. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2013.     

Pharmacophore modeling, 3D-QSAR, and molecular docking study on naphthyridine derivatives as inhibitors of 3-phosphoinositide-dependent protein kinase-1

The 3-phosphoinositide-dependent protein kinase-1 (PDK1) is an imminent target for discovering novel anticancer drugs. In order to understand the structure–activity correlation of naphthyridine-based PDK-1 inhibitors, we have carried out a combined pharmacophore, three-dimensional quantitative structure–activity relationship (3D-QSAR), and molecular docking studies. The study has resulted in six point pharmacophore models with four hydrogen bond acceptors (A), one hydrogen bond donor (D), and one aromatic ring (R) are used to derive a predictive atom-based 3D-QSAR model. The generated 3D-QSAR model shows that the alignment has good correlation coefficient for the training set compounds which comprises the values of R ² = 0.96, SD = 0.2, and F = 198.2. Test set compounds shows Q ² = 0.84, RMSE = 0.56, and Pearson-R = 0.84. The external validation was carried out to validate the predicted QSAR model which shows good predictive power of $ r_{m}^{2} $  = 0.83 and k = 1.01, respectively. The external validation results also confirm the fitness of the model. The results indicated that, atom-based 3D-QSAR models and further modifications in PDK1 inhibitors via pharmacophore hypothesis are rational for the prediction of the activity of new inhibitors in prospect of drug design.     

Effects of bone morphogenetic proteins on primary human renal cells and the generation of bone morphogenetic protein-7-expressing cells for application in bioartificial kidneys

Bioartificial kidneys (BAKs) contain renal cells, and primary human renal proximal tubule cells (HPTCs) have been applied in clinical trials with BAKs. Cell performance within the device is critical. HPTC performance is often compromised under in vitro conditions because of dedifferentiation, transdifferentiation, and tubule formation on substrate surfaces. Herein we tested whether treatments with human recombinant bone morphogenetic protein (BMP)-2 or BMP-7 would improve HPTC performance. We found that both growth factors improved HPTC performance, but more consistent results were obtained with BMP-7. The effects were strongly concentration dependent, and for BMP-7, 25?ng/mL was the optimal concentration, which improved HPTC performance under static and under bioreactor conditions. As an alternative to supplementation with the purified growth factor, we generated HPTCs secreting human recombinant BMP-7. BMP-7 secreted by the cells was bioactive and improved the functional performance of HPTCs, in agreement with our other findings. Together, the results suggested that either supplementation with purified BMP-7 or BMP-7-producing cells could be used to improve cell performance in BAKs. BAKs with BMP-7-producing cells could also be used to deliver the growth factor to kidney patients. Our results suggested that the amount of BMP-7 produced by HPTCs would be sufficient for therapeutic applications.