Clinical and Genetic Analysis of Peutz-Jeghers Syndrome Patients in Taiwan

Peutz-Jeghers syndrome (PJS) is an autosomal dominant inherited disorder that is characterized by intestinal hamartomatous polyps and mucocutaneous pigmentation. Recently, germline mutations in the LKB1 gene have been reported to underlie PJS. The gene that encodes this serine/threonine kinase is located at chromosome 19p13.3. The aim of this study was to investigate the clinical and genetic characteristics of PJS patients in Taiwan. Methods: We searched the patient database of the National Taiwan University Hospital, a tertiary medical center in Taiwan, between January 1990 and November 2005. Patients' clinical information, demographic data, endoscopic pictures, and outcome were reviewed and analyzed. After obtaining informed consent, DNA and RNA were extracted from peripheral blood mononuclear cells and the LKB1 gene was sequenced. Results: A total of 14 unrelated patients who fulfilled the diagnostic criteria of PJS were included, and seven of them had genetic analysis performed. Mucocutaneous pigmentation was the most frequent presentation. Hamartomas occur most commonly in the small intestine (86%). Frequent abdominal complications include intussusception and gastrointestinal bleeding. Four germline mutations were found (57.1%). Three resulted in stop codons at codon 60, 162 (novel mutation), and 308. The fourth mutation was a missense mutation at codon 239 (novel mutation). Conclusion: Compared with other countries, PJS patients in Taiwan tended to have more extensive polyps in the gastrointestinal tract, with intussusception being the most common abdominal symptom. Mutations in the LKB1 gene were identified in 57% of the probands in Taiwan

New insights on early evolution of spiny-rayed fishes (Teleostei: Acanthomorpha)

The Acanthomorpha is the largest group of teleost fishes with about one third of extant vertebrate species. In the course of its evolution this lineage experienced several episodes of radiation, leading to a large number of descendant lineages differing profoundly in morphology, ecology, distribution and behavior. Although Acanthomorpha was recognized decades ago, we are only now beginning to decipher its large-scale, time-calibrated phylogeny, a prerequisite to test various evolutionary hypotheses explaining the tremendous diversity of this group. In this study, we provide new insights into the early evolution of the acanthomorphs and the euteleost allies based on the phylogenetic analysis of a newly developed dataset combining nine nuclear and mitochondrial gene markers. Our inferred tree is time-calibrated using 15 fossils, some of which have not been used before. While our phylogeny strongly supports a monophyletic Neoteleostei, Ctenosquamata (i.e., Acanthomorpha plus Myctophiformes), and Acanthopterygii, we find weak support (bootstrap value < 48%) for the traditionally defined Acanthomorpha, as well as evidence of non-monophyly for the traditional Paracanthopterygii, Beryciformes, and Percomorpha. We corroborate the new Paracanthopterygii sensu Miya et al. (2005) including Polymixiiformes, Zeiformes, Gadiformes, Percopsiformes, and likely the enigmatic Stylephorus chordatus. Our timetree largely agrees with other recent studies based on nuclear loci in inferring an Early Cretaceous origin for the acanthomorphs followed by a Late Cretaceous/Early Paleogene radiation of major lineages. This is in contrast to mitogenomic studies mostly inferring Jurassic or even Triassic ages for the origin of the acanthomorphs. We compare our results to those of previous studies, and attempt to address some of the issues that may have led to incongruence between the fossil record and the molecular clock studies, as well as between the different molecular timetrees

XpsG, the major pseudopilin in Xanthomonas campestris pv. campestris, forms a pilus-like structure between cytoplasmic and outer membranes.

GspG, -H, -I, -J and -K proteins are members of the pseudopilin family. They are the components required for the type II secretion pathway, which translocates proteins across the outer membrane of Gram-negative bacteria to the extracellular milieu. They were predicted to form a pilus-like structure, and this has been shown for PulG of Klebsiella oxytoca by using electron microscopy. In the present study, we performed biochemical analyses of the XpsG protein of Xanthomonas campestris pv. campestris and observed that it is a pillar-like structure spanning the cytoplasmic and outer membranes. Subcellular fractionation revealed a soluble form (SF) of XpsG, in addition to the membrane form. Chromatographic analysis of SF XpsG in the absence of a detergent indicated that it is part of a large complex (>440 kDa). In vitro studies indicated that XpsG is prone to aggregate in the absence of a detergent. We isolated and characterized a non-functional mutant defective in forming the large complex. It did not interfere with the function of wild-type XpsG and was not detectable in the SF. Moreover, unlike wild-type XpsG, which was distributed in both the cytoplasmic and outer membranes, it appeared only in the cytoplasmic membrane. When wild-type XpsG was co-expressed with His6-tagged XpsH but not with untagged XpsH, SF XpsG bound to nickel and co-eluted with XpsH. This result suggests the presence of other pseudopilin components in the XpsG-containing large-sized molecules

Lipopolysaccharide-induced Notch signaling activation through JNK-dependent pathway regulates inflammatory response

Abstract Background Notch and TLR pathways were found to act cooperatively to activate Notch target genes and to increase the production of TLR-induced cytokines in macrophages. However, the mechanism of LPS-induced Notch activation and its role in sepsis still remains unclear. Methods We analyzed the expression patterns of Notch components in a LPS-stimulated murine macrophage cell line using real-time PCR and western blotting. The role of DAPT, a gamma-secretase inhibitor that is known to be a potent Notch inhibitor, in LPS-induced cytokine release and experimental sepsis in mice was also explored. Student's t-test was used to analyze the difference between the two groups. Results We found that Notch signaling was activated after LPS stimulation. The expression of Jagged 1, a Notch ligand, induced by LPS occurred in a JNK-dependent manner. In addition, Notch target genes were upregulated by early Notch-independent activation followed by delayed Notch-dependent activation after LPS stimulation. Disruption of Notch signaling by DAPT attenuated the LPS-induced inflammatory responses, including vascular endothelial growth factor (VEGF) and high-mobility group box chromosomal protein 1 (HMGB1), both in vitro and in vivo and partially improved experimental sepsis survival. Conclusions These findings support the existence of a synergistic effect of Notch signaling and the LPS pathway both in vitro and in vivo. Therefore, in the future Notch inhibitors may be utilized as adjunctive agents for the treatment of sepsis syndrome.</p

Gα₁₂ Drives Invasion of Oral Squamous Cell Carcinoma through Up-Regulation of Proinflammatory Cytokines

<div><p>Oral squamous cell carcinoma (<i>OSCC</i>) ranks among the top ten most prevalent cancers worldwide. Like most head and neck squamous cell carcinomas (HNSCCs), OSCC is highly inflammatory and aggressive. However, the signaling pathways triggering the activation of its inflammatory processes remain elusive. G protein-coupled receptor signaling regulates the inflammatory response and invasiveness of cancers, but it remains unclear whether Gα₁₂ is a critical player in the inflammatory cytokine pathway during the tumorigenesis of OSCC. This study was undertaken to determine the role of Gα₁₂ signaling in the regulation of proinflammatory cytokines in their mediation of OSCC invasion. We found that both the transcription and protein levels of Gα₁₂ are up-regulated in OSCC tumors. The elevated Gα₁₂ expressions in OSCC patients also correlated with extra-capsular spread, an indicator of tumor invasiveness in HNSCCs. This clinical finding was supported by the studies of overexpression and RNAi knockdown of Gα₁₂ in OSCC cells, which demonstrated that Gα₁₂ promoted tumor cell migration and invasion. To understand how Gα₁₂ modulates OSCC invasiveness, we analyzed key biological processes in microarray data upon depletion of Gα₁₂ and found that cytokine- and other immune-related pathways were severely impaired. Importantly, the mRNA levels of IL-6 and IL-8 proinflammatory cytokines in clinical samples were found to be significantly correlated with the increased Gα₁₂ levels, suggesting a potential role of Gα₁₂ in modulating the IL-6 and IL-8 expressions. Supporting this hypothesis, overexpression or RNAi knockdown of Gα₁₂ in OSCC cell lines both showed that Gα₁₂ positively regulated the mRNA and protein levels of IL-6 and IL-8. Finally, we demonstrated that the Gα₁₂ promotion of tumor cell invasiveness was suppressed by the neutralization of IL-6 and IL-8 in OSCC cells. Together, these findings suggest that Gα₁₂ drives OSCC invasion through the up-regulation of IL-6 and IL-8 cytokines.</p></div

Additional file 1: Figure S1. of Interplay of N-Cadherin and matrix metalloproteinase 9 enhances human nasopharyngeal carcinoma cell invasion

The expression of the precursor and active form of ADAM10 after PMA treatment. NPC cells were treated with PMA (100 nM) for the indicated times. Cell lysates underwent western blot analysis to detect levels of the precursor and active form of ADAM10. In response to PMA treatment, the expression of ADAM10 was not significantly changed in NPC cells. (TIF 645 kb

The up-regulation of Gα₁₂ in OSCC patients correlates with Extra-capsular spread.

<p>(A) The Gα₁₂ expression is significantly up-regulated in 55 OSCC tumors compared to 21 normal control tissues (fold change >1.5, <i>P</i><10⁻¹⁰). The microarray data was analyzed by two-way clustering. Each column represents an individual clinical sample. Normalized gene expression values were color coded in percentage relative to the mean: blue for values less than the mean and red for values greater than the mean. (B) Quantitative RT-PCR (qPCR) analysis of Gα₁₂ in 25 OSCC tumors compared to 11 normal mucosa tissues. The results were normalized to GAPDH expression levels and then analyzed by <i>t-test</i>, **<i>P</i><0.01. Box plots display the median, 25th and 75th percentiles. Whiskers represent 5–95 percentiles and dots the outliers. (C) The box plot shows the relative gene expression values (RMA, log2) of Gα₁₂ for extra-capsular spread (ECS) positive (+) and negative (−) patients. Statistical results were analyzed by <i>t-test</i>, **<i>P</i><0.01. (D) Western blot analysis of Gα₁₂ levels in 6 paired samples of OSCC and adjacent normal/pre-cancerous tissues. The Gα₁₂ protein levels were found to be markedly up-regulated in OSCC tumor tissues compared to the GAPDH loading control. (E) Representative immunohistochemical images for Gα₁₂ staining patterns in the paraffin-embedded section of OSCC biopsies. Gα₁₂ immunoreactivity was detected primarily in the membrane and cytoplasm of OSCC (lower panel). In contrast, the adjacent normal and pre-cancerous oral tissues of individual patients showed very low immunoreactivity (upper panel). Original magnification, ×200.</p