Serum TRAIL predicts severity and prognosis in patients with community-acquired pneumonia: a prospective cohort study

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) can trigger the apoptosis pathways through binding to relative death receptors. However, the relationship of TRAIL with community-acquired pneumonia (CAP) was unclear. This study aims at exploring the relationships between circulatory TRAIL with severity and prognosis in CAP patients through a prospective cohort study. The whole of 239 CAP patients was enrolled. Demographic characteristics and clinical information were analyzed. TRAIL and inflammatory cytokines were measured using enzyme-linked immunosorbent assay (ELISA). Circulatory TRAIL was gradually increased in accord with CAP severity scores. Spearman or Pearson correlative analysis indicated that circulatory TRAIL was strongly associated with physiologic indicators among CAP patients. Mixed logistic and linear regression models revealed that circulatory TRAIL was positively correlated with the severity scores in CAP patients. After adjusting for confounders, higher levels of circulatory TRAIL on admission significantly elevated the risks of ICU admission, mechanical ventilation, longer hospital stays, or even death during hospitalization. The predictive capacities of serum TRAIL for death were higher compared with CAP severity scores, inflammatory and infectious indicators. There are obviously positive dose-response relationships between circulatory TRAIL on admission with the severity and poor prognostic outcomes in CAP patients. Circulatory TRAIL on admission may be used as a potential biomarker in predicting the severity and poor prognosis for CAP patients.

[Advances in basic and clinical research on hepatocellular carcinoma in 2016]

Hepatocellular carcinoma (HCC) is still one of common malignant cancers worldwide, with increasing incidence and mortality rates. Early diagnosis and effective treatment for HCC remain to be explored. This article introduces the research advances in the early specific diagnosis and effective therapies for HCC in 2016, such as molecular markers in the specific diagnosis and targeted therapy for HCC, main therapeutic regimens, robot-assisted liver resection, and no-touch radiofrequency ablation.

Cholesterol enrichment upregulates intercellular adhesion molecule-1 in human vascular endothelial cells

Hypercholesterolemia is a major risk factor for atherosclerosis, but the mechanism by which cholesterol activates the endothelium remains undocumented. The present investigation was undertaken to investigate the role of cholesterol, one of the bioactive moieties of the low-density lipoprotein (LDL) particle, in initiating of intracellular signaling in endothelial cells (ECs) and culminating in increased abundance of the intercellular adhesion molecule-1 (ICAM-1). Cholesterol was delivered to human umbilical vein ECs (HUVECs) via cholesterol-enriched liposomes. In HUVECs, the cellular cholesterol:phospholipid ratio increased after 1 h of exposure to cholesterol. The level of ICAM-1 increased in both mRNA and protein after 24 h of cholesterol exposure. ICAM-1 mRNA half-life was not affected by cholesterol exposure. Promoter studies showed greater than two-fold activation of the ICAM-1 gene expression after cholesterol exposure. Electrophoretic mobility shift assay showed that activator protein-1 (AP-1) activity substantially increased after 2 h of exposure to cholesterol. In contrast, cholesterol did not affect nuclear factor-kappaB (NF-kappaB) activity. Results of trans-reporting assay revealed 2.5-fold increased expression of the AP-1-dependent reporter gene after cholesterol exposure whereas NF-kappaB-dependent expression was not affected. The AP-1/Ets (-891 to -908) site, one of the three AP-1-like sites in the ICAM-1 promoter, was most responsive to cholesterol. These data demonstrate for the first time that cholesterol enrichment phenotypically modulates ECs by transcriptionally upregulating ICAM-1 expression.

LDL-activated p38 in endothelial cells is mediated by Ras

Endothelial dysfunction is a major atherogenic proinflammatory event. LDL causes the activation and phenotypic changes of cultured vascular endothelial cells (ECs). We previously reported that LDL activates c-Jun and AP-1 in ECs. In this study, we demonstrated that p38-ATF-2 is activated by LDL in human ECs and that this activation is mediated by Ras. When ECs are incubated with LDL in pathophysiological concentrations, the p38-mediated ATF-2 phosphorylation and ATF-2 transactivation are increased in a time- and dose-dependent manner. To elucidate the upstream mechanism in LDL-activated p38 in ECs, we demonstrate that LDL increases Ras translocation from the cytoplasm to the cellular membrane, with concurrent increases in Ras binding activity to GST-Raf-1. Overexpression of RasN17, a dominant negative mutant of Ras, attenuates the LDL-induced increases in (1) phosphorylation of ATF-2, (2) phosphorylation of c-Jun, (3) AP-1 binding, and (4) AP-1-driven luciferase activity. To study the effect of p38 in the regulation of an LDL targeting gene, we show that a specific p38 inhibitor attenuates LDL-induced E-selectin at the mRNA level. Thus, LDL activates both p38 and JNK signaling pathways through Ras activation, and furthermore, these events may play an important role in LDL-induced endothelial activation.

Lipoprotein promotes caveolin-1 and Ras translocation to caveolae: role of cholesterol in endothelial signaling

To explore the role of LDL in caveolin-Ras regulation in human endothelial cells (ECs), we incubated confluent human umbilical vein endothelial cells (HUVECs) with LDL. This resulted in a high steady-state caveolin-1 (Cav-1) expression at both the mRNA and protein levels. LDL exposure appeared not to regulate the abundance of Cav-1. Immunofluorescence staining showed that Cav-1 protein migrated from the cytoplasm to the cell membrane after LDL exposure. Cav-1 protein and cholesterol partitioned mainly into the caveola fractions, and LDL increased both Cav-1 and cholesterol in these fractions. Ras protein in caveola fractions was also increased by LDL. Increased Ras was detected in Cav-1 immunoprecipitated samples, and conversely, increased Cav-1 was found in Ras-immunoprecipitated samples. We also demonstrated LDL-increased Ras activity in HUVECs by measuring the GTP/GTP+GDP ratio of Ras with [(32)P]orthophosphate labeling in the cells. Finally, we determined the binding of [(3)H]-labeled free cholesterol and recombinant H-Ras to Cav-1 fusion proteins in vitro. Both cholesterol and Ras bound to full-length GST-Cav-1, scaffolding domain (61-101), and C-terminal (135-178) Cav-1 fusion peptides. Addition of cholesterol enhanced Ras binding to the full-length and scaffolding domain of Cav-1 but not to the C-terminal Cav-1. These findings strongly suggest a role for Cav-1 in cholesterol trafficking and cholesterol-mediated intracellular signaling, which may mediate EC activation by LDL.

c-Jun triggers apoptosis in human vascular endothelial cells

In endothelial cells (ECs), the transcription factor c-Jun is induced by a variety of stimuli that perturb EC function. To extend our understanding of the role of c-Jun in EC physiology, we have directed overexpression of c-Jun in human umbilical vein ECs by using a tetracycline-regulated adenoviral expression system. In this study, we report a novel observation using this system. Specific expression of c-Jun is a sufficient trigger for ECs to undergo apoptosis, as demonstrated by a set of combined assays including an ELISA specific for histone-associated DNA fragmentation, DNA laddering, and TdT-mediated dUTP nick end labeling (TUNEL). Tetracycline can effectively shut off c-Jun overexpression and prevent EC apoptosis. Cleavage of poly(ADP-ribose) polymerase was also detected in ECs overexpressing c-Jun. Moreover, inhibitors of cysteine proteases blocked the apoptosis, suggesting a caspase-associated mechanism involved in proapoptotic effects of c-Jun. To gain further insight into the role of c-Jun as a pathophysiological regulator of EC death, TAM67, a dominant-negative mutant of c-Jun, was overexpressed in human umbilical vein ECs to abrogate endogenous c-Jun/activator protein-1 activation. H(2)O(2)-triggered apoptosis was largely attenuated in ECs overexpressing TAM67. Together, these results suggest that c-Jun, as a proapoptotic molecule, may play a role in mediating the cell death program in vascular endothelium.

[Changes in gut hormones after Roux-en-Y cholangio-jejunostomy]

In order to explore the mechanism of secondary gastric acid hypersecretion after Roux-en-Y Cholangio-jejunostomy (CJR-Y), we studied the changes of gastric acid secretion and determined the levels of somatostatin (SS), gastrin (Gn), neurotensin (NT), beta-endorphin (beta-EP) in serum, gastric juice and pyloric antrum in patients with CJR-Y. The results showed that gastric hypersecretion developed, levels of SS in those specimens decreased significantly and the content of Gn increased obviously after CJR-Y; whereas the content of NT and beta-EP did not change significantly. We concluded that the decreased level of SS plays a role in the mechanism.

[Mouse lung adenocarcinoma (LA-795)--study by histochemistry, light and electron microscopy]

A strain of spontaneous lung adenocarcinoma of inbred T739 mice has been successfully transplanted and retained for generations in the syngenic mice. By light microscopy, the cancer cells appeared oval or cubic and were arranged in a few or multiple layers, sometimes in papillary form. Metastasis to lung was 100%. By histochemistry, it was negative for glycogen, ALKase and all mucin stains, while being positive for LDHase, G6PDHase and SDHase stains. By electron microscopy, numerous microvilli on the cell surface, lamellar bodies, osmiophilic globuli, Golgi apparatus mitochondria and granular endoplasmic reticula in the cytoplasm were observed. The lung tumor strain, recognized as mouse lung adenocarcinoma (papillary type), may derive from the type II alveolar epithelial cells.