The molecular mechanism by which obesity induces insulin resistance is not completely understood. The aim of this study was to determine how lipopolysaccharide-induced tumor necrosis-α factor (LITAF) influenced obesity-induced insulin resistance using a cellular co-culture system. The cells were divided into 3 groups: palmitic acid (PA) stimulation group, LITAF small interfering RNA (siRNA) group and untreated (NC) group. The LITAF siRNA was used for knockdown of LITAF expression in human THP-1 macrophages. The expression levels of LITAF, IRS-2, IRS-2Tyr465, PI3K, and GLUT2 in each group were measured by using quantitative reverse transcriptase real-time polymerase chain reaction and Western blotting. The expression of LITAF was much higher in the PA group than in the siRNA and NC groups (*P<0.05); meanwhile, the expression of IRS-2, IRS-2Tyr465, PI3K, and GLUT2 was much lower in the PA group than in the NC group (*P<0.05); however, IRS-2, IRS-2Tyr465, PI3K, and GLUT2 had much higher expression in the siRNA group than in the PA group (*P<0.05). It is concluded that PA can induce insulin resistance in liver cells and knockdown of LITAF expression can reduce insulin resistance in liver cells, suggesting LITAF may regulate the insulin signal transduction pathway involved in obesity-induced insulin resistance.

Background/Aims: This study investigated quality of life (QoL) of patients 6 months after surgery for early or advanced gastric cancer. Methodology: Between June, 2006 and December, 2009, 39 patients undergoing laparoscopic assisted distal gastrectomy (LADG) and 35 patients undergoing open distal gastrectomy (ODG) were enrolled. All the patients completed a validated questionnaire (EORTC QLQ-C30) and site specific module (QLQ-STO22) after surgery. Clinicopathological characteristics were compared and the patients' QoL were emphasized. Results: There were no significant differences between the two groups in age, comorbidities, curative degree, tumor stage, etc. In terms of QLQ-C30 items, significantly better role, cognitive, emotional and social functioning in the LADG group were identified as well as a significant lower incidence rate of constipation. Physical functioning, dyspnea, pain, fatigue, insomnia, diarrhea, financial difficulties and global health status, were not significantly different between the two groups. With respect to QLQ-STO22 items, LADG associated with lower incidence of reflux symptoms and better body image. However, there were no significant differences on symptoms of dysphagia, pain, eating restrictions, dry mouth, change of taste, anxiety and hair loss. QoL stratified by Billroth II reconstruction procedure gave similar results except for role functioning and body image, LADG had higher score compared with ODG. Conclusions: Long-term follow-up results suggest that LADG might help improve the QoL in patients with gastric cancer. Well-designed large scale randomized controlled trials are needed.

Endogenous cannabinoids acting at CB(1) receptors stimulate appetite, and CB(1) antagonists show promise in the treatment of obesity. CB(1)(-/-) mice are resistant to diet-induced obesity even though their caloric intake is similar to that of wild-type mice, suggesting that endocannabinoids also regulate fat metabolism. Here, we investigated the possible role of endocannabinoids in the regulation of hepatic lipogenesis. Activation of CB(1) in mice increases the hepatic gene expression of the lipogenic transcription factor SREBP-1c and its targets acetyl-CoA carboxylase-1 and fatty acid synthase (FAS). Treatment with a CB(1) agonist also increases de novo fatty acid synthesis in the liver or in isolated hepatocytes, which express CB(1). High-fat diet increases hepatic levels of the endocannabinoid anandamide (arachidonoyl ethanolamide), CB(1) density, and basal rates of fatty acid synthesis, and the latter is reduced by CB(1) blockade. In the hypothalamus, where FAS inhibitors elicit anorexia, SREBP-1c and FAS expression are similarly affected by CB(1) ligands. We conclude that anandamide acting at hepatic CB(1) contributes to diet-induced obesity and that the FAS pathway may be a common molecular target for central appetitive and peripheral metabolic regulation.

Cannabinoids and ethanol can activate the same reward pathways, which could suggest endocannabinoid involvement in the rewarding effects of ethanol. The high ethanol preference of young (6-10 weeks) C57BL6J mice is reduced by the cannabinoid receptor 1 (CB1) antagonist SR141716A to levels observed in their CB1 knockout littermates or in old (26-48 weeks) wild-type mice, in both of which ethanol preference is unaffected by SR141716A. Similarly, SR141716A inhibits food intake in food-restricted young, but not old, wild-type mice. There are no age-dependent differences in the tissue levels of the endocannabinoids anandamide and 2-arachidonoylglycerol or the density of CB1 in the hypothalamus, limbic forebrain, amygdala, and cerebellum. CB1-stimulated guanosine 5'-[gamma-thio]triphosphate (GTP[gammaS]) binding is selectively reduced in the limbic forebrain of old compared with young wild-type mice. There is no age-dependent difference in G(i) or G(o) subunit protein expression in the limbic forebrain, and the selective reduction in GTP[gammaS] labeling in tissue from old mice is maintained in a receptorG protein reconstitution assay by using functional bovine brain G protein. These findings suggest that endocannabinoids acting at CB1 contribute to ethanol preference, and decreased coupling of CB1 to G proteins in the limbic forebrain by mechanisms other than altered receptor or G protein levels may be involved in the age-dependent decline in the appetite for both ethanol and food.

The development of hepatocellular carcinoma (HCC) is a multistep process associated with changes in host gene expression, some of which correlate with the appearance and progression of tumor. Preneoplastic changes in gene expression result from altered DNA methylation, the actions of hepatitis B and C viruses, and point mutations or loss of heterozygosity (LOH) in selected cellular genes. Tumor progression is characterized by LOH involving tumor suppressor genes on many chromosomes and by gene amplification of selected oncogenes. The changes observed in different HCC nodules are often distinct, suggesting heterogeneity on the molecular level. These observations suggest that there are multiple, perhaps redundant negative growth regulatory pathways that protect cells against transformation. An understanding of the molecular pathogenesis of HCC may provide new markers for tumor staging, for assessment of the relative risk of tumor formation, and open new opportunities for therapeutic intervention.

The contribution of stem and progenitor cell dysfunction and depletion in normal aging remains incompletely understood. We explored this concept in the Klotho mouse model of accelerated aging. Analysis of various tissues and organs from young Klotho mice revealed a decrease in stem cell number and an increase in progenitor cell senescence. Because klotho is a secreted protein, we postulated that klotho might interact with other soluble mediators of stem cells. We found that klotho bound to various Wnt family members. In a cell culture model, the Wnt-klotho interaction resulted in the suppression of Wnt biological activity. Tissues and organs from klotho-deficient animals showed evidence of increased Wnt signaling, and ectopic expression of klotho antagonized the activity of endogenous and exogenous Wnt. Both in vitro and in vivo, continuous Wnt exposure triggered accelerated cellular senescence. Thus, klotho appears to be a secreted Wnt antagonist and Wnt proteins have an unexpected role in mammalian aging.

Cannabinoids, including the bioactive constituents of the marijuana plant, their synthetic analogs, and endogenous lipids with cannabinoid-like activity, produce their biological effects by interacting with specific receptors. To date, two G protein-coupled cannabinoid receptors have been identified by molecular cloning, CB1 receptors mainly expressed in the brain and mediating most of the neurobehavioral effects of cannabinoids and CB2 receptors expressed by immune and hematopoietic tissues. Recent findings indicate that some cannabinoid effects are not mediated by either CB1 or CB2 receptors, and in some cases there is compelling evidence to implicate additional receptors in these actions. These include transient receptor potential vanilloid 1 (TRPV1) receptors and as-yet-unidentified receptors implicated in the endothelium-dependent vasodilator effect of certain cannabinoids and in the presynaptic inhibition of glutamatergic neurotransmission in the hippocampus. The case for these additional receptors is being reviewed here.

Minocycline has been demonstrated to be neuroprotective after spinal cord injury (SCI). However, the cellular consequences of minocycline treatment on the secondary injury response are poorly understood. We examined the ability of minocycline to reduce oligodendrocyte apoptosis, microglial/macrophage activation, corticospinal tract (CST) dieback, and lesion size and to improve functional outcome after SCI. Adult rats were subjected to a C7-C8 dorsal column transection, and the presence of apoptotic oligodendrocytes was assessed within the ascending sensory tract (AST) and descending CST in segments (3-7 mm) both proximal and distal to the injury site. Surprisingly, the numbers of dying oligodendrocytes in the proximal and distal segments were comparable, suggesting more than the lack of axon-cell body contiguity played a role in their demise. Minocycline or vehicle control was injected into the intraperitoneal cavity 30 min and 8 hr after SCI and thereafter twice daily for 2 d. We report a reduction of apoptotic oligodendrocytes and microglia within both proximal and distal segments of the AST after minocycline treatment, using immunostaining for active caspase-3 and Hoechst 33258 staining in combination with cell-specific markers. Activated microglial/macrophage density was reduced remote to the lesion as well as at the lesion site. Both CST dieback and lesion size were diminished after minocycline treatment. Footprint analysis revealed improved functional outcome after minocycline treatment. Thus, minocycline ameliorates multiple secondary events after SCI, rendering this clinically used drug an attractive candidate for SCI treatment trials.

Stem cells play a critical role in normal tissue maintenance, and mutations in these stem cells may give rise to cancer. We hypothesize that melanoma develops from a mutated stem cell and therefore residual stem cell characteristics should be able to be identified in melanoma cell lines. We studied three metastatic melanoma cell lines that exhibited multiple morphologic forms in culture and demonstrated the capacity to pigment. We used the ability to efflux Hoechst 33342 dye, a technique known to enrich for stem cells in many tissues, to segregate cell populations. The cells with the greatest ability to efflux the dye were (1) small in size,(2) had the capacity to give rise to larger cell forms, and (3) had the greatest ability to expand in culture. The small cells were found to have a decreased proliferative rate and were less melanized. Large dendritic cells that appeared to be nonproliferative were identified in cultures. Treatment with cytosine beta-D-arabinofuranoside hydrochloride (Ara-C) expanded the large cell population but the residual proliferative capacity, both in vitro and in vivo, remained concentrated in the smaller cell fraction. Antigenic staining patterns were variable and heterogeneous. Nestin (a neural stem cell marker) and gp100 (premelanosomal marker) favored the smaller cell population, while nerve growth factor receptor often labeled larger cells. Morphologic and antigenic heterogeneity remained intact after clonal purification. These findings are consistent with the behavior expected for a tumor based on stem cell biology; this finding has diagnostic and therapeutic implications for melanocytic neoplasias.

Autologous and synthetic vessel grafts have been used as a vascular substitute for cardiovascular bypass procedures. However, these materials are limited by the availability of appropriate caliber autologous vessels, increased susceptibility to thrombosis and intimal hyperplasia following surgery. Electrospinning technology offers the potential for controlling composition, structure and mechanical properties of biomaterials. Vascular graft scaffolds have been fabricated using electrospun polymer blends of Type I collagen, elastin from ligamentum nuchae, and poly (d,l-lactide-co-glycolide). This study demonstrates improved electrospinning characteristics versus previous studies by increasing polymer concentration and adding PLGA to the polymer blend. Additionally, new in vitro biocompatibility and mechanical testing data is presented. The scaffolds possess tissue composition and mechanical properties similar to native vessels. The electrospun vessel matrix is biocompatible and does not elicit local or systemic toxic effects when implanted in vivo. This study demonstrates the promise of electrospinning as a fabrication process for a functional vascular graft for clinical use.

Scientific interest to find a treatment for spinal cord injuries has led to the development of numerous experimental strategies to promote axonal regeneration across the spinal cord injury site. Although these strategies have been developed in acute injury paradigms and hold promise for individuals with spinal cord injuries in the future, little is known about their applicability for the vast majority of paralyzed individuals whose injury occurred long ago and who are considered to have a chronic injury. Some studies have shown that the effectiveness of these approaches diminishes dramatically within weeks after injury. Here we investigated the regenerative capacity of rat rubrospinal neurons whose axons were cut in the cervical spinal cord 1 year before. Contrary to earlier reports, we found that rubrospinal neurons do not die after axotomy but, rather, they undergo massive atrophy that can be reversed by applying brain-derived neurotrophic factor to the cell bodies in the midbrain. This administration of neurotrophic factor to the cell body resulted in increased expression of growth-associated protein-43 and Talpha1 tubulin, genes thought to be related to axonal regeneration. This treatment promoted the regeneration of these chronically injured rubrospinal axons into peripheral nerve transplants engrafted at the spinal cord injury site. This outcome is a demonstration of the regenerative capacity of spinal cord projection neurons a full year after axotomy.

microRNAs are endogenous small noncoding RNAs that regulate gene expression negatively at posttranscriptional level. This latest addition to the complex gene regulatory circuitry revolutionizes our way to understanding physiological and pathological processes in the human body. Here we investigated the possible role of microRNAs in the development of multidrug resistance (MDR) in gastric cancer cells. microRNA expression profiling revealed a limited set of microRNAs with altered expression in multidrug- resistant gastric cancer cell line SGC7901/VCR compared to its parental SGC7901 cell line. Among the downregulated microRNAs are miR-15b and miR-16, members of miR-15/16 family, whose expression was further validated by qRT-PCR. In vitro drug sensitivity assay demonstrated that overexpression of miR-15b or miR-16 sensitized SGC7901/VCR cells to anticancer drugs whereas inhibition of them using antisense oligonucleotides conferred SGC7901 cells MDR. The downregulation of miR-15b and miR-16 in SGC7901/VCR cells was concurrent with the upregulation of Bcl-2 protein. Enforced mir-15b or miR-16 expression reduced Bcl-2 protein level and the luciferase activity of a BCL2 3' untranslated region-based reporter construct in SGC7901/VCR cells, suggesting that BCL2 is a direct target of miR-15b and miR-16. Moreover, overexpression of miR-15b or miR-16 could sensitize SGC7901/VCR cells to VCR-induced apoptosis. Taken together, our findings suggest that miR-15b and miR-16 could play a role in the development of MDR in gastric cancer cells at least in part by modulation of apoptosis via targeting BCL2.(c) 2008 Wiley-Liss, Inc.