Distribution of conjugated linoleic acid and metabolites in different lipid fractions in the rat liver.

Conjugated linoleic acid (CLA) is known to provide certain health benefits in experimental animal models. The major CLA isomer in food is c 9,t11-CLA. A primary objective of this study was to investigate the uptake of c 9,t11-CLA and its downstream metabolites into various lipid fractions in the liver of rats fed either a high or low CLA diet (containing 0.1 or 0.8 g CLA/100 g diet, respectively). As expected, the levels of all conjugated diene (CD) fatty acids (CD 18:2 + CD 18:3 + CD 20:3 + CD 20:4) were elevated about 8-fold in the high CLA diet group. However, there was no change in the distribution of CLA and CLA metabolites into various lipid fractions due to CLA intake. Unlike linoleic acid or gamma-linolenic acid, which were distributed mainly in phospholipids, CD 18:2, CD 18:3, and CD 20:3 were incorporated primarily in neutral lipid. Furthermore, the incorporation of all nonconjugated unsaturated fatty acids was not perturbed by CLA. Regardless of the level of CLA in the diet, CD 20:4 was predominantly enriched in phosphatidylserine and phosphatidylinositol. In contrast, arachidonic acid was primarily enriched in phosphatidylcholine and less so in phosphatidylethanolamine. The above findings may have potential implication regarding the role of CLA in modulating eicosanoid metabolism.     

Environmental effect on plasma thyroxine (T4), 3,5,3'-triido-L-thyronine (T3), prolactin and cyclic adenosine 3',5'-monophosphate (cAMP) content in the mudskippers Periophthalmus chrysospilos and Boleophthalmus boddaerti

1. In both Periophthalmus chrysospilos and Boleophthalmus boddaerti, T4 was involved in enabling the fish to cope with terrestrial stress and not in osmoregulation in waters of different salinities. In B. boddaerti, however, 3,5,3'-triiodo-L-thyronine (T3) played a more significant role in osmoregulation under the various aquatic conditions. 2. The control of osmoregulation mechanisms in P. chrysospilos kept in waters of different salinities was taken over by prolactin instead, whereas prolactin was only involved in osmoregulation in B. boddaerti under extreme osmotic stress (100% SW). Prolactin is also involved in the terrestrial adaptations of P. chrysospilos. 3. Plasma cAMP levels in P. chrysospilos increased with increasing salinity of the external environment (Tables 4 and 5) implicating its role in the stimulation of chloride secretion and in intracellular isosmotic regulation. 4. Significant increase in the plasma cAMP level of B. boddaerti submerged in 100% SW was also observed. However, the plasma cAMP levels of B. boddaerti fully submerged in 30% and 50% SW were not significantly different from the control as these conditions simulated those of their natural habitats.     

Soluble CD8 during T cell activation

The CD8 Ag has long been used as a surface marker for the identification of cytotoxic and suppressor cells. Recently CD8-positive cells have been shown to release a soluble form of the CD8 Ag. We have devised a sandwich monoclonal enzyme immunoassay for the quantitation of this released CD8. Soluble CD8 was released in response to lymphocyte activation. In vitro, PHA or anti-CD3 mAb-mediated T cell activation led to release of CD8 into the culture supernatant. In vivo, serum from patients with EBV-induced infectious mononucleosis (IM), a disease associated with intense CD8+ T cell activation, demonstrated elevations in soluble CD8 (7939 U/ml, day 0) compared to serum from normal controls (289 U/ml). Levels of soluble CD8 correlated (r = 0.82, p less than 0.001) with the increased percentage of CD8+/HLA-DR+ (activated CD8+ T cells) observed in acute IM. Sequential analysis of serum during the course of IM shows that soluble CD8 levels parallel the decline in CD8+/HLA-DR+ cells that occurs with the resolution of the disease. These data suggest that released CD8 may be of value in monitoring the involvement of CD8+ T cells in response to a pathologic event. The functional role of the released CD8 molecule will require further investigation.     

Multicenter phase 1/2 application of adenovirus-specific T cells in high-risk pediatric patients after allogeneic stem cell transplantation

Background

Adenovirus (ADV) reactivation can cause significant morbidity and mortality in children after allogeneic stem cell transplantation. Antiviral drugs can control viremia, but viral clearance requires recovery of cell-mediated immunity.

The presence of serotonin in cigarette smoke – a possible mechanistic link to 5-HT-induced airway inflammation

We previously reported the involvement of serotonin (5-HT) metabolism in cigarette smoke-induced oxidative stress in rat lung in vivo. Here, we report cigarette smoke as a source of serotonin (5-HT) to the airways and aim at investigating the effects of 5-HT on oxidative stress and inflammation in human bronchial epithelial cells (BEAS-2B). A 5-HT analog was identified to be present in aqueous phase cigarette smoke using the LC-MS/MS approach, which was later confirmed by a 5-HT enzyme-linked immune assay (EIA). Furthermore, exposure to 5-HT caused a time-dependent elevation of intracellular ROS level, which was blocked in the presence of apocynin (a NOX inhibitor). In support, the immunoblot analysis indicated that there was an increase in the expression of NOX2 time-dependently. 5-HT-induced elevation of IL-8 at both mRNA and protein levels was observed, which was inhibited by TEMPOL (a free radical scavenger), and inhibitors for p38 MAPK (SB203580) and ERK (U0126), in line with the time-dependent phosphorylation of p38 MAPK and ERK. In conclusion, our findings suggest that 5-HT presented in bronchial epithelium of smokers may be involved in cigarette smoke-induced oxidative stress and inflammation via activation of p38 MAPK and ERK pathway after the formation of free radicals.     

Molecular characteristics and interactions of the intermediate filament protein synemin. Interactions with alpha-actinin may anchor synemin-containing heterofilaments.

Synemin is a cytoskeletal protein originally identified as an intermediate filament (IF)-associated protein because of its colocalization and copurification with the IF proteins desmin and vimentin in muscle cells. Our sequencing studies have shown that synemin is an unusually large member (1,604 residues, 182,187 Da) of the IF protein superfamily, with the majority of the molecule consisting of a long C-terminal tail domain. Molecular interaction studies demonstrate that purified synemin interacts with desmin, the major IF protein in mature muscle cells, and with alpha-actinin, an integral myofibrillar Z-line protein. Furthermore, expressed synemin rod and tail domains interact, respectively, with desmin and alpha-actinin. Analysis of endogenous protein expression in SW13 clonal lines reveals that synemin is coexpressed and colocalized with vimentin IFs in SW13.C1 vim+ cells but is absent in SW13.C2 vim- cells. Transfection studies indicate that synemin requires the presence of another IF protein, such as vimentin, in order to assemble into IFs. Taken in toto, our results suggest synemin functions as a component of heteropolymeric IFs and plays an important cytoskeletal cross-linking role by linking these IFs to other components of the cytoskeleton. Synemin in striated muscle cells may enable these heterofilaments to help link Z-lines of adjacent myofibrils and, thereby, play an important role in cytoskeletal integrity.