Changes in RNA, DNA, protein contents and growth of turbot Scophthalmus maximus larvae and juveniles

The growth potential of turbot Scophthalmus maximus larvae and juveniles was studied using nucleic acid-based indices and protein variables. The experiment was carried out from 4 to 60 days post hatching (dph). A significant increase in instantaneous growth rate during metamorphosis and retarded growth rate during post-metamorphic phase were observed. Ontogenetic patterns of DNA, RNA and protein all showed developmental stage-specific traits. The RNA:DNA ratio decreased up to 12 dph, then increased rapidly till 19 dph and fluctuated until 35 dph followed by a decline to the end. The RNA:DNA ratio was positively correlated with growth rate of juveniles during the post-metamorphic phase, whereas this ratio was not a sensitive indicator of growth during the pre-metamorphic phase and metamorphosis. The protein:DNA ratio showed a similar tendency to the RNA:DNA ratio. Changes of DNA content and protein:DNA ratio revealed that growth of S. maximus performed mainly by hyperplasia from 4 to 12 dph and hypertrophy until 21 dph during the pre-metamorphic larval phase. Growth was dominantly hypertrophical from the early- to mid-metamorphosing phase and hyperplastic thereafter. The results show that the DNA content and protein:DNA ratio can evaluate growth rates of larval and juvenile S. maximus on a cellular level.

Role of neurocrine somatostatin on sphincter of Oddi contractility and intestinal ischemia reperfusion-induced acute pancreatitis in macaques

BACKGROUND

Intestinal ischemia-reperfusion (IIR) is implicated in the pathogenesis of severe acute pancreatitis (SAP). This study investigates the impact of neurocrine somatostatin (SST) on the contraction of sphincter of Oddi (SO) during IIR.

METHODS

Intestinal ischemia-reperfusion model in macaques was induced by occluding the superior mesenteric artery. Pancreatitis was confirmed by pancreatic histology and serum levels of amylase and lipase. SST and its receptors (SSTRs) in SO were visualized by immunohistochemistry. Effects of SST on the contraction of the isolated SO were recorded in vitro.

KEY RESULTS

Inflammatory scores of the pancreas and serum levels of amylase or lipase in the macaques that underwent IIR were significantly higher than those in the control group. The frequency and amplitude of phasic contraction of the circular muscle in SO was increased by SST in a concentration-dependent manner. Compared with the control group, SST innervation or SSTR2 expression in SO of macaques treated with IIR was increased 5.2 fold or 5.6 fold respectively. Prophylactic infusion of SST before IIR significantly reduced SST immunoreactive fibers in SO as compared to those in the IIR group and remarkably alleviated the pathophysiologic changes due to IIR.

CONCLUSIONS & INFERENCES

Increased SST innervation in SO during the early phase of IIR associated with the contraction of circular muscle of SO, which might be one of the promoting factors associated with the development of SAP. Prevention of IIR or intervention of SO contraction after occurrence of acute pancreatitis might be beneficial for preventing SAP.

Roasted licorice extracts dampen high glucose-induced mesangial hyperplasia and matrix deposition through blocking Akt activation and TGF-beta signaling

Diabetic nephropathy (DN) characterized as nephrotic syndrome and diffuse glomerulosclerosis can cause renal failure and end-stage kidney disease. Expansion of mesangial matrix around capillaries in the kidney glomeruli is a prominent feature of DN. This study investigated whether licorice extracts inhibited mesangial cell (MC) proliferation and matrix accumulation induced by high glucose (HG). Human renal MC were cultured in media containing 5.5 mM glucose plus 27.5 mM mannitol as an osmotic control or 33 mM glucose for 3 d in the presence of water or ethanol extracts from raw licorice (LW, LE) or roasted licorice (RLW, RLE). Non-polar components including glycyrrhetic acid were elevated during licorice roasting, whereas polar components soluble in water extracts were diminished. Exposure of cells to HG caused significant increases in collagen IV secretion and connective tissue growth factor (CTGF) expression, which was appeased by RLW and RLE at transcriptional levels. The inhibitory potency was high in the order of RLE > or = RLW > or = LE > > LW. Non-polar glycyrrhetic acid but not glycyrrhizin retarded HG-stimulated mesangial matrix deposition through diminishing CTGF expression. In addition, RLW and RLE but not LW modulated membrane type matrix metalloproteinase-1 (MT-1 MMP) expression, MMP-2 activity and tissue inhibitor of MMP-2 (TIMP-2), which facilitated the degradation of mesangial matrix. Furthermore, the augmented expression of CTGF and TIMP-2 in HG-exposed cells was mediated by Akt activation and TGF-beta/Smad signaling through PKCbeta2-responsive signaling pathways. However, HG-down-regulated MT-1 MMP expression was independent of activation of ERK1/2 and Akt when using their inhibitors of DB98059 (ERK1/2) and LY294002 (Akt) alone or in combination. These results demonstrate that extracts from roasted licorice may be highly potent therapeutic agents for the prevention and treatment of mesangial fibrosis and glomerulosclerosis leading to diabetes nephropathy due to longstanding diabetes mellitus.

Plasma Cathepsin L and Its Related Pro/Antiangiogenic Factors Play Useful Roles in Predicting Rich Coronary Collaterals in Patients with Coronary Heart Disease

Cathepsin L enhances angiogenesis by increasing extracellular matrix degradation and remodelling. This study investigated whether plasma cathepsin L could be used as a biomarker to predict collateral formation in patients with coronary heart disease (CHD). Patients with CHD ( n = 218; aged 67 ± 11 years) underwent coronary angiography and were categorized as having either ‘poor’ or ‘rich’ collaterals. Plasma cathepsin L, the proangiogenic placenta growth factor (PLGF) and the antiangiogenic factors, cystatin C and endostatin, were measured. Elevated cathepsin L and PLGF levels were independently and significantly associated with enhanced collateral formation in patients with CHD; subgroup analyses also showed a significant correlation in patients with diabetes and acute coronary syndrome. Plasma endostatin and cystatin C levels were not significantly correlated with coronary collateral formation. Plasma cathepsin L and PLGF, acting as important modulators of angiogenesis, could be used as biomarkers to predict coronary collateral formation in patients with CHD.

Ferrous chelator 2,2'-dipyridyl attenuates cerebral vasospasm after experimental subarachnoid haemorrhage in rabbits

The effect of 2,2'-dipyridyl (DP) on cerebral vasospasm was investigated in a double-injection rabbit model of subarachnoid haemorrhage (SAH). Thirty-six animals were divided between four groups: control (sham-operated), SAH (model alone), SAH + DP (the SAH model in which DP dissolved in dimethyl sulphoxide [DMSO] was injected once daily for 5 days into the cisterna magna), and SAH + DMSO (the SAH model in which DMSO [vehicle] was injected daily for 5 days). There were significant differences in the basilar artery luminal area, wall thickness, neurological deficit score and vasospasm index between the SAH + DP and SAH groups. There was a significant negative correlation between arterial luminal area and arterial wall thickness, and also between the neurological deficit score and vasospasm index. Cells that were positive for terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labelling (TUNEL) and p53 expression were significantly increased in the SAH + DMSO and SAH groups, but not in the SAH + DP group, versus controls. Thus, DP may attenuate cerebral vasospasm after SAH by suppressing p53-induced apoptosis in the cerebral vessels.

A gene on the HER2 amplicon, C35, is an oncogene in breast cancer whose actions are prevented by inhibition of Syk

Background:

C35 is a 12 kDa membrane-anchored protein endogenously over-expressed in many invasive breast cancers. C35 (C17orf37) is located on the HER2 amplicon, between HER2 and GRB7. The function of over-expressed C35 in invasive breast cancer is unknown.

Methods:

Tissue microarrays containing 122 primary human breast cancer specimens were used to examine the association of C35 with HER2 expression. Cell lines over-expressing C35 were generated and tested for evidence of cell transformation in vitro.

Results:

In primary breast cancers high levels of C35 mRNA expression were associated with HER2 gene amplification. High levels of C35 protein expression were associated with hallmarks of transformation, such as, colony growth in soft agar, invasion into collagen matrix and formation of large acinar structures in three-dimensional (3D) cell cultures. The transformed phenotype was also associated with characteristics of epithelial to mesenchymal transition, such as adoption of spindle cell morphology and down-regulation of epithelial markers, such as E-cadherin and keratin-8. Furthermore, C35-induced transformation in 3D cell cultures was dependent on Syk kinase, a downstream mediator of signalling from the immunoreceptor tyrosine-based activation motif, which is present in C35.

Conclusion:

C35 functions as an oncogene in breast cancer cell lines. Drug targeting of C35 or Syk kinase might be helpful in treating a subset of patients with HER2-amplified breast cancers.

MEK/ERK and p38 MAPK regulate chondrogenesis of rat bone marrow mesenchymal stem cells through delicate interaction with TGF-beta1/Smads pathway

OBJECTIVES

This study was carried out to reveal functions and mechanisms of MEK/ERK and p38 pathways in chondrogenesis of rat bone marrow mesenchymal stem cells (BMSCs), and to investigate further any interactions between the mitogen-activated protein kinase (MAPK) and transforming growth factor-beta1 (TGF-beta1)/Smads pathway in the process.

MATERIALS AND METHODS

Chondrogenic differentiation of rat BMSCs was initiated in micromass culture, in the presence of TGF-beta1, for 2 weeks. ERK1/2 and p38 kinase activities were investigated by Western Blot analysis. Specific MAPK inhibitors PD98059 and SB20350 were employed to investigate regulatory effects of MEK/ERK and p38 signals on gene expression of chondrocyte-specific markers, and TGF-beta1 downstream pathways of Smad2/3.

RESULTS

ERK1/2 was phosphorylated in a rapid but transient manner, whereas p38 was activated in a slow and sustained way. The two MAPK subtypes played opposing roles in mediating transcription of cartilage-specific genes for Col2alpha and aggrecan. TGF-beta1-stimulated gene expression of chondrogenic regulators, Sox9, Runx2 and Ihh, was also affected by activity of PD98059 and SB203580, to different degrees. However, influences of MAPK inhibitors on gene expression were relatively minor when not treated with TGF-beta1. In addition, gene transcription of Smad2/3 was significantly upregulated by TGF-beta1, but was regulated more subtly by treatment with MAPK inhibitors.

CONCLUSIONS

MAPK subtypes seemed to regulate chondrogenesis with a delicate balance, interacting with the TGF-beta1/Smads signalling pathway.

The neuronal repellent SLIT2 is a target for repression by EZH2 in prostate cancer

The neuronal repellent SLIT2 is repressed in a number of cancer types primarily through promoter hypermethylation. SLIT2, however, has not been studied in prostate cancer. Through genome-wide location analysis we identified SLIT2 as a target of Polycomb group (PcG) protein EZH2. The EZH2-containing Polycomb repressive complexes bound to the SLIT2 promoter inhibiting its expression. SLIT2 was down-regulated in a majority of metastatic prostate tumors exhibiting a negative correlation with EZH2. This repressed expression could be restored by methylation inhibitors or EZH2-suppressing compounds. In addition, a low level of SLIT2 expression was associated with aggressive prostate, breast and lung cancers. Functional assays showed that SLIT2 inhibited prostate cancer cell proliferation and invasion. Thus, this study demonstrated for the first time epigenetic silencing of SLIT2 in prostate tumors, and supported SLIT2 as a potential biomarker for aggressive solid tumors. Importantly, PcG-mediated repression may serve as a precursor for the silencing of SLIT2 by DNA methylation in cancer.

Recombinant adenovirus IL-24-Bax promotes apoptosis of hepatocellular carcinoma cells in vitro and in vivo

Gene therapy promises to become an alternative choice for the treatment of hepatic cancer. In many cancers, the delivery of chimeric proteins by adenovirus vector has been reported to induce apoptosis. This study was performed to evaluate whether the recombinant adenovirus interleukin (IL)-24-Bax can induce apoptosis in hepatocellular carcinoma cells in vitro and in vivo. Several recombinant adenoviruses were constructed, and the expression of their encoded proteins was measured. The effects of the recombinant adenovirus on hepatocellular carcinoma cells and the normal hepatocyte cell line were investigated through cell viability and apoptosis assays after the cells were treated with Ad.Luc, Ad.IL-24, Ad.Bax or Ad.IL-24-Bax. The mechanism involved was also explored. A tumor-bearing mouse model was used to evaluate the effects of the adenovirus on tumor volume and cell apoptosis in vivo. Ad.IL-24-Bax selectively suppressed growth of hepatocellular carcinoma cells and induced apoptosis, but it had little influence on the normal hepatocytes. The mechanism of this response may include the effect of the 10HRE/VEGF385 promoter and the synergistic effect of IL-24 and Bax. Ad.IL-24-Bax also suppressed tumor growth in nude mice and induced apoptosis. Ad.IL-24-Bax may be a useful tool for gene therapy of hepatic cancer.

In-situ monitoring of the thermal desorption of alkanethiols with surface plasmon resonance spectroscopy (SPRS)

Thermal desorption investigations on self-assembled monolayers (SAMs) had previously been carried out using techniques such as thermal desorption spectroscopy (TDS), scanning tunneling microscopy (STM) and X-ray photo-electron spectroscopy (XPS). In this paper, the thermal dissociation of alkanethiols (CnH(2n + 1)SH) at various chain lengths (n= 6, 12, 18) on sputtered gold layers was monitored in-situ using the Kretschmann surface plasmon resonance configuration on a spectroscopic ellipsometer. We found that the longest alkanethiol (C18) exhibits the greatest thermal stability, manifested by the least amount of angular shift, during heating, in the resonant spectral features. Predictions of desorption temperatures from SPRS for the longer chain thiols are in good agreement with XPS measurements.

The survey of HIV/AIDS related knowledge, attitude and behaviour among migrant peasant workers in middle city in China

OBJECTIVES

To explore HIV/AIDS related knowledge, attitude and behaviour among migrant peasant workers in Changsha, which is a inland city in central China, and to provide evidence that educating this population may help to prevent the spread of HIV/AIDS in China.

METHODS

A total of 1782 migrant peasant workers participated in the study. A questionnaire was used to determine their knowledge of HIV/AIDS and related attitude and behaviour items.

RESULTS

The majority of the respondents had a rather low level of overall HIV/AIDS knowledge and its prevention, had what constituted risky behaviour in this regard and a generally low acceptance of HIV-infected persons. Furthermore, their behaviour and attitude were analysed with respect to their educational level, occupational class and score of HIV/AIDS related knowledge.

CONCLUSIONS

The results of this investigation will help healthcare professionals develop a sensitive and specific educational programme for migrant peasant workers. Educating this population will be a very important aspect of HIV/AIDS prevention in China.

Light-harvesting chlorophyll a/b-protein: Three-dimensional structure of a reconstituted membrane lattice in negative stain

The three-dimensional structure of a negatively stained hexagonal membrane lattice containing the light-harvesting chlorophyll a/b-protein complex and phospholipids has been determined to 30-A resolution by image reconstruction from electron micrographs. This lattice has p321 symmetry, a lattice constant of 125 A and a thickness of 75 A. The monomer is shown to be an elongated molecule about 65 A long in the dimension perpendicular to the plane of the membrane. It spans the hydrophobic domain of the membrane in an asymmetric fashion, projecting [unk]20 A from one surface and less from the other. On the basis of this image and available biochemical data, the structure of the complex in the native thylakoid membrane is proposed.