Tight Junction Regulation by Morphine and HIV-1 Tat Modulates Blood–Brain Barrier Permeability

Human immunodeficiency virus (HIV)-1 patients who abuse opiates are at a greater risk of developing neurological complications of AIDS. Alterations in blood-brain barrier (BBB) integrity are associated with cytoskeletal disorganization and disruption of tight junction (TJ) integrity. We hypothesize that opiates in combination with HIV-1 viral proteins can modulate TJ expression in primary brain microvascular endothelial cells (BMVEC), thereby compromising BBB integrity and exacerbating HIV-1 neuropathogenesis. We investigated the effect of morphine and/or tat on the expression of TJ proteins ZO-1, JAM-2, Occludin and P-glycoprotein and the functional effects of TJ modulation in BMVEC. Morphine and/or tat, via the activation of pro-inflammatory cytokines, intracellular Ca(2+) release, and activation of myosin light chain kinase, modulated TJ expression resulting in decreased transendothelial electric resistance and enhanced transendothelial migration across the BBB. These studies may lead to the development of novel anti-HIV-1 therapeutics that target specific TJ proteins, thus preventing TJ disruption in opiate using HIV-1 patients.     

Cytokine profile and induction of T helper type 17 and regulatory T cells by human peripheral mononuclear cells after microbial exposure

The immunomodulatory effects of probiotics were assessed following exposure of normal peripheral blood mononuclear cells (PBMC), cord blood cells and the spleen-derived monocyte/macrophage cell line CRL-9850 to Lactobacillus acidophilus LAVRI-A1, Lb. rhamnosus GG, exopolysaccharides (EPS)-producing Streptococcus thermophilus St1275, Bifidobacteriun longum BL536, B. lactis B94 and Escherichia coli TG1 strains. The production of a panel of pro- and anti-inflammatory cytokines by PBMC following bacterial stimulation was measured, using live, heat-killed or mock gastrointestinal tract (GIT)-exposed bacteria, and results show that (i) all bacterial strains investigated induced significant secretion of pro- and anti-inflammatory cytokines from PBMC-derived monocytes/macrophages; and (ii) cytokine levels increased relative to the expansion of bacterial cell numbers over time for cells exposed to live cultures. Bifidobacteria and S. thermophilus stimulated significant concentrations of transforming growth factor (TGF)-β, an interleukin necessary for the differentiation of regulatory T cells (T(reg) )/T helper type 17 (Th17) cells and, as such, the study further examined the induction of Th17 and T(reg) cells after PBMC exposure to selected bacteria for 96 h. Data show a significant increase in the numbers of both cell types in the exposed populations, measured by cell surface marker expression and by cytokine production. Probiotics have been shown to induce cytokines from a range of immune cells following ingestion of these organisms. These studies suggest that probiotics' interaction with immune-competent cells produces a cytokine milieu, exerting immunomodulatory effects on local effector cells, as well as potently inducing differentiation of Th17 and T(reg) cells.     

Suppression of MMP-9 expression in brain microvascular endothelial cells (BMVEC) using a gold nanorod (GNR)-siRNA nanoplex

Inhibition of Matrix metalloproteinase-9 (MMP-9) activity using delivery of short interfering RNA (siRNA) molecules to brain microvascular endothelial cells (BMVECs) that constitute the BBB may have a significant impact on reducing the BBB permeability. Gold nano rods (GNRs) can electrostatically bind with MMP-9 siRNA to form a nanoplex and the uptake of this nanoplex by BMVEC cells can result in suppression of MMP-9 expression. The current study explores if this GNR-MMP-9 siRNA nanoplex gene silencing modulates the expression of tight junction (TJ) proteins in the BMVEC. The endothelial TJ's of the BBB play a critical role in controlling cellular traffic into the central nervous system. We hypothesize that silencing of the MMP-9 gene expression in BMVEC will increase the expression of TJ proteins thereby decrease endothelial permeability. Our results showed a significant increase in the gene and protein expression of TJ proteins: ZO-1, Occludin and Claudin-5 in BMVEC cells that were transfected with the GNRs-siRNA-MMP-9 nanoplex suggesting that BBB disruption, which results from loss of TJ function due to MMP-9 activation during neuroinflammation can be prevented by silencing MMP-9 expression.     

Hepatoprotective and antioxidant activity of a mangrove plant Lumnitzera racemosa

Objective

To identify the hepatoprotective and in vitro antioxidant activity of Lumnitzera racemosa (L. racemosa) leaf extract.

Methods

Animals in Group 1 served as vehicle control, Group 2 served as hepatotoxin (CCL₄ treated) group, Group 3 served as positive control (Silymarin) group, and Group 4, 5 and 6 served as (75, 150 and 300 mg/kg bw p.o.) L. racemosa leaf extract treated groups. Moreover, in vitro antioxidant DPPH, hydroxyl radical scavenging activity (HRSA), NO, ferric reducing antioxidant power (FRAP), lipid hydroperoxide (LPO) and super oxide dismutase (SOD) were also analyzed for the leaf extract.

Results

The levels of the serum parameters such as serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), alkaline phosphatase (ALP), bilirubin, cholesterol (CHL), sugar and lactate dehydrogenase (LDH) were significantly increased in CCL₄ treated rats when compared with the control group (P<0.05). But the L. racemosa leaf extract treated rats showed maximum reduction of SGOT [(210.36±19.63) IU/L], SGPT [(82.37±13.87) IU/L], ALP [(197.63±23.43) IU/L], bilurubin [(2.15±0.84) mg/dL], cholesterol [(163.83±15.63) mg/dL], sugar [(93.00±7.65) mg/dL] and LDH [(1134.00±285.00) IU/L] were observed with the high dose (300 mg/kg bw) of leaf extract treated rats. Histopathological scores showed that, no visible changes were observed with high dose (300 mg/kg bw) of leaf extract treated rats except few mild necrosis. The IC₅₀ values were observed as (56.37±4.87) µg/mL, (57.68±1.98) µg/mL, (64.15±2.90) µg/mL, (61.94±3.98) µg/mL, (94.53±1.68) µg/mL and (69.7±2.65) µg/mL for DPPH, HRSA, NO, FRAP, LPO and SOD radical scavenging activities, respectively.

Conclusions

In conclusion, the hepatoprotective effect of the L. racemosa leaf extract might be due to the presence of phenolic groups, terpenoids and alkaloids and in vitro antioxidant properties.     

Computed tomographic angiography in tetralogy of Fallot

Echocardiography is often inadequate for imaging tetralogy of Fallot, prompting cineangiography. This study prospectively evaluated multidetector computed tomographic angiography for preoperative evaluation of tetralogy of Fallot in 112 consecutive patients. Forty-eight had nonconfluent or hypoplastic pulmonary arteries (mean z-score, -2; range, -11.1-0.13) permitting only palliative or no surgery; 64 had adequate pulmonary artery anatomy (mean z-score, 0.59; range, -2.53-3.4) allowing total repair. The surgical data of 50 patients who underwent total correction were compared with transthoracic echocardiography and multidetector computed tomographic angiography findings. Multidetector computed tomographic angiography tended to reveal unsuspected collaterals and coronary abnormalities besides outlining the right ventricular outflow tract and pulmonary artery branches. The branch pulmonary artery diameter z-score was the most important determinant of surgical strategy, with the worst figures being associated with no surgical options or palliative surgery, and the best figures leading to corrective surgery. The mean radiation dose was 3.45 mSv. Multidetector computed tomographic angiography is a powerful supplement to echocardiography in the preoperative evaluation of tetralogy of Fallot.     

A study on the protective effect of Cynodon dactylon leaves extract in diabetic rats

Objective To investigate the antidiabetic, antioxidant and hypolipidemic efficacy of Cynodon dactylon in diabetic rats. Methods The experimental rats were randomly divided into three groups: Group I: control; Group II: Alloxan diabetic, untreated; and Group III: Alloxan diabetic treated with ethanolic extract of C. dactylon leaves (450 mg/kg bw). Experimental diabetes was induced by alloxan in a single dose of 150 mg/kg bw. Results A Significant diminution of fasting blood sugar level was observed and also ...     

Comparative physico-chemical and in vitro properties of fibrillated collagen scaffolds from different sources

Collagen from different sources was isolated and designed as scaffolds to act as a three-dimensional substrate for culturing human skin fibroblasts, which can be used as dermal substitutes. The thermodynamic behavior of the scaffolds developed was analyzed through Differential Scanning Calorimetric (DSC) and Thermogravimetric analysis (TGA). Analysis by Fourier Transform Infrared Spectroscopy (FTIR) revealed the functional groups in the scaffolds and the mechanical stability of various scaffolds was assessed through tensile strength analysis. Human skin fibroblasts were cultured on the developed scaffolds to assess their cellular interaction and behavior, and the morphological characteristics of the cultured fibroblasts were evaluated using Scanning Electron Microscopy (SEM). The collagen scaffold exhibited unique features when developed from various sources and it was observed that cells could grow and proliferate well and spread as a monolayer in the reconstituted collagen scaffold.