Polyphenols from Parabarium huaitingii and their positive inotropic and anti-myocardial infarction effects in rats

Eight phenolic compounds, including (-)-epicatechin (1) and seven proanthocyanidins (2-8), were obtained from the butanol extract of Parabarium huaitingii (PHB). Their chemical structures were identified based on analyses of mass spectra (MS), NMR, CD spectra, and partial acid catalyzed thiolytic degradation. The observation made by laser scanning confocal microscope found a significant increase of the concentration of intracellular Ca²+ ([Ca²+](i)) in single myocytes when the PHB was added, while compounds 1 and 3 had the same physiological effect. Further investigations showed PHB had a dose-dependent positive inotropic effect on isolated right atria and papillary muscle of left ventricle of the rat, while having no significant influence on the spontaneous beating rate of the isolated right atria. The inotropic effect of PHB could be greatly abolished by pretreating the myocardium in Ca²+-free solution. These findings indicated that PHB could significantly increase [Ca²+](i) in myocytes, which was greatly dependent on the influx of extracellular Ca²+. Compounds 1 and 3 might be the effective ingredients of the inotropic effect of PHB. In addition, PHB could also significantly decrease the infarct size of the heart on acute myocardial infarction (AMI) model rats, which suggested its myocardial protective effect on ischemic myocardium. The positive inotropic effect of PHB, together with its myocardial protective effect on AMI, suggested that PHB had a promising potential for the prevention and treatment of heart failure, especially the one that was caused by AMI.

IKKα represses a network of inflammation and proliferation pathways and elevates c-Myc antagonists and differentiation in a dose-dependent manner in the skin

Inhibitor of nuclear factor κB kinase-α (IKKα) is required for maintaining skin homeostasis and preventing skin tumorigenesis. However, its signaling has not been extensively investigated. In the present study, we generated two mouse lines that expressed different levels of transgenic IKKα in the basal epidermis under the control of keratin-5 promoter and further evaluated their effects on the major pathways of inflammation, proliferation, and differentiation in the skin. Regardless of the transgenic IKKα levels, the mice develop normally. Because IKKα deletion in keratinocytes blocks terminal differentiation and induces epidermal hyperplasia and skin inflammation, we depleted the endogenous IKKα in these transgenic mice and found that the transgenic IKKα represses epidermal thickness and induces terminal differentiation in a dose-dependent manner. Also, transgenic IKKα was found to elevate expression of Max dimer protein 1 (Mad1) and ovo-like 1, c-Myc antagonists, but repress activities of epidermal growth factor receptor (EGFR), extracellular signal-regulated kinase (ERK), Jun-amino-terminal kinases, c-Jun, signal transducer and activator of transcription 3 (Stat3), and growth factor levels in a dose-dependent fashion in the skin. Moreover, EGFR reduction represses IKKα deletion-induced excessive ERK, Stat3 and c-Jun activities, and skin inflammation. These new findings indicate that elevated IKKα expression not only represses epidermal thickness and induces terminal differentiation, but also suppresses skin inflammation by an integrated loop. Thus, IKKα maintains skin homeostasis through a broad range of signaling pathways.

The radiosensitization effect of NS398 on esophageal cancer stem cell-like radioresistant cells

This study aimed to investigate the cancer stem cell (CSC) properties of radioresistant esophageal cancer cells and the radiosensitization effect of NS398, a cyclooxygenase (COX)-2 inhibitor, on them. Fractionated irradiation was applied to acquire radioresistant esophageal cancer cells. Clone formation assay was employed to detect cell radiosensitivity and cloning formation ability. Cell viability was determined by methyl tetrazolium colorimetry assay. Cell cycle distribution and apoptosis were detected by flow cytometry. Tumorigenicity was investigated by xenograft tumorigenicity assay. Expression levels of β-catenin were detected by reverse transcription polymerase chain reaction or Western blot. As results, radioresistant Eca109R50Gy cells were obtained through fractional irradiation from Eca109 cells; Eca109R50Gy cells displayed higher ability of proliferation, colony-formation, and 40 times tumorigenic ability as high as that of the Eca109 cells in vivo. Meantime stem cell marker β-catenin was elevated in Eca109R50Gy cells. All of the above implied that Eca109R50Gy cells have some properties of CSCs. NS398 enhanced the radiosensitivity of Eca109R50Gy cells accompanied by down-regulating the expression of β-catenin. In conclusion, radioresistant Eca109R50Gy cells carried some CSC-like properties; NS398 enhanced the radiosensitivity of CSC-like Eca109R50Gy cells and this function may partly through down-regulating the expression of β-catenin. These findings both stress the important role of CSCs in esophageal cancer radioresistance and provide new insight on possible application of COX-2 inhibitors on CSCs.

NANOG promotes cancer stem cell characteristics and prostate cancer resistance to androgen deprivation

Cancer cell molecular mimicry of stem cells (SC) imbues neoplastic cells with enhanced proliferative and renewal capacities. In support, numerous mediators of SC self-renewal have been evinced to exhibit oncogenic potential. We have recently reported that shRNA-mediated knockdown of the embryonic stem cell (ESC) self-renewal gene NANOG significantly reduced the clonogenic and tumorigenic capabilities of various cancer cells. In this study, we sought to test the potential pro-tumorigenic functions of NANOG, particularly, in prostate cancer (PCa). Using quantitative RT-PCR, we first confirmed that PCa cells expressed NANOG mRNA primarily from the NANOGP8 locus on chromosome 15q14. We then constructed a lentiviral promoter reporter in which the -3.8 kb NANOGP8 genomic fragment was used to drive the expression of green fluorescence protein (GFP). We observed that NANOGP8-GFP⁺ PCa cells exhibited cancer stem cell (CSC) characteristics such as enhanced clonal growth and tumor regenerative capacity. To further investigate the functions and mechanisms of NANOG in tumorigenesis, we established tetracycline-inducible NANOG overexpressing cancer cell lines, including both prostate (Du145 and LNCaP) and breast (MCF-7) cancer cells. NANOG induction promoted drug-resistance in MCF-7 cells, tumor regeneration in Du145 cells, and, most importantly, castration-resistant tumor development in LNCaP cells. These pro-tumorigenic effects of NANOG were associated with key molecular changes, including an upregulation of molecules such as CXCR4, IGFBP5, CD133 and ALDH1. The present gain-of-function studies, coupled with our recent loss-of-function work, establish the integral role for NANOG in neoplastic processes and shed light on its mechanisms of action.

Stress enhances muscle nociceptor activity in the rat

Chronic widespread pain, such as observed in irritable bowel (IBS) and fibromyalgia (FMS) syndrome, are markedly affected by stress. While such forms of stress-induced hyperalgesia are generally considered manifestations of "central sensitization," recent studies in patients with IBS and FMS suggest an additional, peripheral contribution. To examine the effect of stress on muscle nociceptor function, we evaluated activity in nociceptors innervating the gastrocnemius muscle in an animal model of chronic widespread pain, water avoidance stress, in the rat. This stressor, which produces mechanical hyperalgesia in skeletal muscle produced a significant decrease (∼34%) in mechanical threshold of muscle nociceptors and a marked, ∼two-fold increase in the number of action potentials produced by a prolonged (60 s) fixed intensity suprathreshold 10 g stimulus. Stress also induced an increase in conduction velocity from 1.25 m/s to 2.09 m/s, and increased variability in neuronal activity. Given that these changes, each of at least moderate magnitude, would be expected to enhance nociceptor activity, it is likely that, taken together, they contribute to the enhanced nociception observed in this model of stress-induced chronic widespread pain.

Primary typical carcinoid tumour in the retromolar region with prominent squamous differentiation: a case report

Primary carcinoid tumours of the oral cavity are rare, with only one case of atypical carcinoid tumour reported in the literature. In this article, a case of primary typical carcinoid tumour in the retromolar region in a 46-year-old woman is described. Histologically, the tumour was characterized by submucosal proliferation of medium-sized monomorphous epithelioid cells with an organoid and nesting pattern of growth. Mitoses and necrosis were not found. Prominent squamous differentiation was present. Immunohistochemically, the tumour was diffuse positive for cytokeratin (CK) (AE1/AE3), CK7, p63, neurone-specific enolase, synaptophysin, and chromogranin. To the authors' knowledge, this is the first report of primary typical carcinoid tumour in the oral cavity.

IL-9(+) IL-10(+) T cells link immediate allergic response to late phase reaction

The mechanism underlying late-phase allergic reactions (LPR) remains incompletely understood. This study aimed to investigate the role of a newly described subset of T cells, interleukin (IL)-9(+) IL-10(+) T cells, in the pathogenesis of LPR. Using a T helper type 2 (Th2) inflammatory mouse model, we examined the frequency of IL-9(+) IL-10(+) T cells in the jejunum by immunohistochemistry. The LPR in the jejunum was observed afterwards. The cytokine profile of IL-9(+) IL-10(+) T cells was characterized and the major cytokine that plays the critical role in the initiation of LPR was investigated. Abundant IL-9(+) IL-10(+) T cells as well as inflammatory cell extravasation in the jejunal sections were observed in sensitized mice 48 h after specific antigen challenge. IL-9(+) IL-10(+) T cells expressed high levels of macrophage inflammatory protein 1 (MIP1) that could be enhanced by T cell receptor activation. MIP1 facilitated macrophage extravasation in local tissue. Macrophage-derived MIP2 contributed to neutrophil infiltration in the intestine in LPR. Pretreatment with anti-MIP antibody inhibited the LPR in the intestine. IL-9(+) IL-10(+) T cells play an important role in LPR. This subset of T cells has the potential to be a novel therapeutic target in the treatment of LPR and LPR-related inflammation.

pGh9:ISS1 transpositional mutations in Streptococcus uberis UT888 causes reduced bacterial adherence to and internalization into bovine mammary epithelial cells

Streptococcus uberis is an important mastitis pathogen that affects dairy cows worldwide. In spite of the economic impact caused by the high prevalence of S. uberis intramammary infections (IMI) in many well-managed dairy herds, pathogenic strategies and associated virulence factors of S. uberis are not well understood. It has been shown that S. uberis attaches to and internalizes into mammary epithelial cells and can survive inside cells for extended periods of time. We hypothesize that early attachment to and internalization into mammary epithelial cells is a critical step for the establishment of intramammary infection. The aim of this study is to identify and characterize chromosomally encoded virulence factors of S. uberis that allow early bacterial attachment to and internalization into mammary epithelial cells. A common approach used to identify virulence factors is by generating random insertion mutants that are defective in adherence to and internalization into mammary epithelial cells using pGh9:ISS1 mutagenesis system. A random insertion mutant library of S. uberis strain UT888 was created using a thermo-sensitive plasmid pGh9:ISS1 carrying ISS1 insertion sequence. Integration of the insertion sequence into the chromosome of these mutant clones was confirmed by PCR and Southern blot. Southern blot analysis of mutant clones also showed that insertional integration was random. Of 1000 random chromosomal insertion mutants of S. uberis strain UT888 screened, 32 had significantly reduced ability to adhere to and internalize into mammary epithelial cells. Chromosomal mapping of insertion sequence integration sites in some of these defective mutants showed integration into penicillin binding protein 2A (pbp2A), sensor histidine kinase, tetR family regulatory protein, phosphoribosylaminoimidazole carboxylase catalytic subunit (purE), lactose phosphotransferase, phosphoribosylamine glycine ligase (purD), and other genes involved in metabolic activities. These proteins may have a significant role in early bacterial colonization of the mammary gland during infection.