Characterization of the phenotype of high collagen-producing fibroblast clones in systemic sclerosis, using a new modified limiting-dilution method

BACKGROUND

Overproduction of type I collagen in fibroblasts of systemic sclerosis (SSc) is the hallmark of fibrosis. Establishment and characterization of the phenotype of SSc fibroblasts has been hindered by the heterogeneity between fibroblasts and the lack of adequate cloning methods.

AIM

To establish and investigate the characteristics of the SSc high collagen-producing fibroblast phenotype.

METHODS

Primary cultured fibroblasts from skin biopsies of patients with SSc and normal controls were cloned by a new modified limiting-dilution method. All clones were divided into different subpopulations based on their α1(I) procollagen (COL1A1) mRNA level detected by real-time reverse transcriptase PCR assay. In the different subpopulations, cell growth and cycle distribution were analysed by MTT and flow cytometry, COL1A1 promoter activity was examined by transient transfection, and the binding activity of Sp1 to the COL1A1 proximal promoter was investigated by quantitative chromatin immunoprecipitation.

RESULTS

The clonogenicities of SSc and normal control fibroblasts were similar, but the mean COL1A1 mRNA level of clones and the percentage of the subpopulation with a high COL1A1 mRNA level were significantly higher in SSc fibroblasts than in controls. There was no significant difference on cell growth and cycle between different subpopulations of SSc and control fibroblasts. The COL1A1 proximal promoter activity and its binding activity to Sp1 in the clones were strongly correlated with their COL1A1 mRNA level.

CONCLUSION

Overproduction of collagen in an SSc fibroblast subpopulation seems to result mainly from the abnormally activated transcription of COL1A1 rather than from overproliferation of fibroblasts. The new modified limiting-dilution method provides a useful means for characterizing cells with heterogeneous phenotypes.

Multidose pharmacokinetics of orally administered florfenicol in the channel catfish (Ictalurus punctatus)

Plasma disposition of florfenicol in channel catfish was investigated after an oral multidose (10 mg/kg for 10 days) administration in freshwater at water temperatures ranging from 24.7 to 25.9 °C. Florfenicol concentrations in plasma were analyzed by means of liquid chromatography with MS/MS detection. After the administration of florfenicol, the mean terminal half-life (t(1/2)), maximum concentration at steady-state (Css (max)), time of Css (max) (T(max)), minimal concentration at steady-state (Css (min)), and Vc /F were 9.0 h, 9.72 μg/mL, 8 h, 2.53 μg/mL, and 0.653 L/kg, respectively. These results suggest that florfenicol administered orally at 10 mg/kg body weight for 10 days could be expected to control catfish bacterial pathogens inhibited in vitro by a minimal inhibitory concentration value of <2.5 μg/mL.

Intermediate-conductance Ca(2+) -activated potassium and volume-sensitive chloride channels in endothelial progenitor cells from rat bone marrow mononuclear cells

AIM

Bone marrow endothelial progenitor cells (BMEPCs) are believed to be a promising cell source for regenerative medicine; however, their electrophysiology properties have not been fully clarified, which is important to the clinical application of BMEPCs. The current study was designed to determine the transmembrane ion currents and mRNA expression levels of related ion channel subunits in rat BMEPCs.

METHODS

Bone marrow mononuclear cells were isolated by density gradient separation and cultured in EPC medium. The transmembrane ion currents were determined using whole-cell patch-voltage clamp technique, and the levels of mRNA and protein expressions of functional ionic channels were measured using RT-PCR and western immunoblot analysis.

RESULTS

We observed two types of ionic currents in undifferentiated rat BMEPCs. One was Ca(2+) -activated potassium current (I(kca) ), which was seen in approx. 90% of cells when 1 μm Ca(2+) was employed in pipette solution, and it was predominantly inhibited by intermediate-conductance I(kca) inhibitor clotrimazole. The other one was volume-sensitive chloride current (I(cl) ), which was detected in 85.7% of cells when BMEPCs were subjected to K(+) -free hypotonic extracellular solution, whose currents could be inhibited by 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB). The corresponding ion channel genes and proteins, KCNN4 for I(kca) and Clcn3 for I(cl) , were confirmed by RT-PCR and western immunoblot analysis of BMEPCs.

CONCLUSION

Our results demonstrated for the first time that rat BMEPCs expressed intermediate-conductance Ca(2+) -activated potassium currents and volume-sensitive chloride currents, and corresponding genes and proteins of these two channels are KCNN4 and Clcn3 respectively.

Integrated genomic analyses identify WEE1 as a critical mediator of cell fate and a novel therapeutic target in acute myeloid leukemia

Acute myeloid leukemia (AML) remains a therapeutic challenge despite increasing knowledge about the molecular origins of the disease, as the mechanisms of AML cell escape from chemotherapy remain poorly defined. We hypothesized that AML cells are addicted to molecular pathways in the context of chemotherapy and used complementary approaches to identify these addictions. Using novel molecular and computational approaches, we performed genome-wide shRNA screens to identify proteins that mediate AML cell fate after cytarabine exposure, gene expression profiling of AML cells exposed to cytarabine to identify genes with induced expression in this context, and examination of existing gene expression data from primary patient samples. The integration of these independent analyses strongly implicates cell cycle checkpoint proteins, particularly WEE1, as critical mediators of AML cell survival after cytarabine exposure. Knockdown of WEE1 in a secondary screen confirmed its role in AML cell survival. Pharmacologic inhibition of WEE1 in AML cell lines and primary cells is synergistic with cytarabine. Further experiments demonstrate that inhibition of WEE1 prevents S-phase arrest induced by cytarabine, broadening the functions of WEE1 that may be exploited therapeutically. These data highlight the power of integrating functional and descriptive genomics, and identify WEE1 as potential therapeutic target in AML.

Aliskiren vs. angiotensin receptor blockers in hypertension: meta-analysis of randomized controlled trials

BACKGROUND

Aliskiren, a newly discovered renin inhibitor, blocks the renin-angiotensin system (RAS) from the top of the enzyme cascade and therefore, might provide comparable or even superior clinical efficacy of blood pressure (BP) control than angiotensin receptor blockers (ARBs). With this meta-analysis, we aimed to compare the efficacy and tolerability of aliskiren and ARBs in the treatment of hypertension in the short-term treatment period.

METHODS

Reports of randomized controlled trials (RCTs) comparing aliskiren and ARBs in patients with hypertension were selected by a search of the Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE. The main outcome measures were reduction in diastolic BP (DBP) and systolic BP (SBP) and rates of therapeutic response and BP control. We also compared the tolerability of aliskiren and ARBs. Revman v5.0 was used to obtain the pooled estimates.

RESULTS

We analyzed data from 10 reports of trials involving 3,732 participants. DBP and SBP reduction did not differ between aliskiren and ARBs (weighted mean difference (WMD), -0.18; 95% confidence interval (CI), -1.07 to 0.71, and WMD, 0.15; 95% CI, -1.38 to 1.69, respectively). Aliskiren and ARB treatment did not differ in rates of BP control or therapeutic response. Moreover, aliskiren and ARB treatment led to a similar number of adverse events, severe adverse events, and withdrawal due to adverse events.

CONCLUSION

Aliskiren is as effective as ARBs (losartan, valsartan, and irbesartan) in controlling BP and does not differ from ARBs in risk of adverse events.

Enhanced ZAG production by subcutaneous adipose tissue is linked to weight loss in gastrointestinal cancer patients

Background:

Profound loss of adipose tissue is a hallmark of cancer cachexia. Zinc-α2-glycoprotein (ZAG), a recently identified adipokine, is suggested as a candidate in lipid catabolism.

Methods:

In the first study, eight weight-stable and 17 cachectic cancer patients (weight loss ⩾5% in previous 6 months) were recruited. Zinc-α2-glycoprotein mRNA and protein expression were assessed in subcutaneous adipose tissue (SAT), subcutaneous adipose tissue morphology was examined and serum ZAG concentrations were quantified. In the second cohort, ZAG release by SAT was determined in 18 weight-stable and 15 cachectic cancer patients. The effect of ZAG on lipolysis was evaluated in vitro.

Results:

Subcutaneous adipose tissue remodelling in cancer cachexia was evident through shrunken adipocytes with increased fibrosis. In cachectic cancer patients, ZAG mRNA was upregulated (2.7-fold, P=0.028) while leptin mRNA decreased (2.2-fold, P=0.018); serum ZAG levels were found to be unaffected. Zinc-α2-glycoprotein mRNA correlated positively with weight loss (r=0.51, P=0.01) and serum glycerol levels (r=0.57, P=0.003). Zinc-α2-glycoprotein release by SAT was also elevated in cachectic patients (1.5-fold, P=0.024) and correlated with weight loss (r=0.50, P=0.003). Recombinant ZAG stimulated lipolysis in human adipocytes.

Conclusions:

Zinc-α2-glycoprotein expression and secretion by adipose tissue is enhanced in cachectic cancer patients. Given its lipid-mobilising effect, ZAG may contribute to adipose atrophy associated with cancer cachexia in human beings.

Macrophage-secreted factors inhibit ZAG expression and secretion by human adipocytes

Zinc-alpha2-glycoprotein (ZAG), a novel adipokine, is downregulated in adipose tissue in obesity, a state characterized by increased adipose tissue macrophage infiltration and chronic low-grade inflammation. This study investigated whether macrophage-secreted factors and TNF-alpha, a major product of macrophages, modulate ZAG expression and secretion by human adipocytes. ZAG was produced primarily by adipocytes, and not by preadipocytes and macrophages. Incubation of preadipocytes with macrophage-conditioned medium for up to 12 days decreased ZAG mRNA and protein release, and the expression of adipogenic markers (PPARgamma and C/EBPalpha). Adipocytes treated with macrophage-conditioned medium for 24h displayed significant reductions in ZAG mRNA and release. Chronic TNF-alpha treatment let to significant decreases in ZAG expression and secretion, but marked upregulation of pro-inflammatory cytokines and chemokines (IL-6, leptin, IL-8, MCP-1 and RANTES) in adipocytes. These findings suggest that macrophage-associated inflammation may play a significant role in the downregulation of ZAG in adipose tissue in obesity.

Downregulation of zinc-{alpha}2-glycoprotein in adipose tissue and liver of obese ob/ob mice and by tumour necrosis factor-alpha in adipocytes

Zinc-alpha2-glycoprotein (ZAG, also listed as AZGP1 in the MGI Database), a lipid-mobilising factor, has recently been suggested as a potential candidate in the modulation of body weight. We investigated the effect of increased adiposity on ZAG expression in adipose tissue and the liver and on plasma levels in obese (ob/ob) mice compared with lean siblings. The study also examined the effect of the pro-inflammatory cytokine tumour necrosis factor-alpha (TNFalpha) on ZAG expression in adipocytes. Zag mRNA levels were significantly reduced in subcutaneous (fourfold) and epididymal (eightfold) fat of ob/ob mice. Consistently, ZAG protein content was decreased in both fat depots of ob/ob mice. In the liver of obese animals, steatosis was accompanied by the fall of both Zag mRNA (twofold) and ZAG protein content (2.5-fold). Plasma ZAG levels were also decreased in obese mice. In addition, Zag mRNA was reduced in epididymal (fivefold) and retroperitoneal (fivefold) adipose tissue of obese (fa/fa) Zucker rats. In contrast to Zag expression, Tnfalpha mRNA levels were elevated in adipose tissue (twofold) and the liver (2.5-fold) of ob/ob mice. Treatment with TNFalpha reduced Zag gene expression in differentiated adipocytes, and this inhibition was chronic, occurring at 24 and 48 h following TNFalpha treatment. It is concluded that ZAG synthesis in adipose tissue and the liver is downregulated, as are its circulating levels, in ob/ob mice. The reduced ZAG production may advance the susceptibility to lipid accumulation in these tissues in obesity, and this could be at least in part attributable to the inhibitory effect of TNFalpha.

Identification of site(s) of insulin nitration by peroxynitrite and characterization of its structural change

Insulin nitration mediated by peroxynitrite (ONOO(-)) has been implicated in diabetes and diabetic cardiovascular complications. In this study, we identified the nitration sites of porcine insulin by infusion of ONOO(-) and quantified its secondary structural change. Insulin was cleaved with V8 protease to six peptides (four of them contained each tyrosine residue), then analyzed by HPLC-MS and further confirmed the nitration sites by HPLC-MS/MS. At low accumulated doses of peroxynitrite, the main products were two different mono-nitrated insulin species at Tyr-A19 and Tyr-B26 with Tyr-A19 being predominant as shown by peptide mapping. Also, the content of alpha-helix structure of insulin reduced to 22.9 % and random-coil structure increased to 30.2 % (compare with native insulin of 41.7 % and 13.7 %, respectively) as determined by FTIR spectra.

Efficient human growth hormone gene expression in the milk of non-transgenic goats

Heterogenous expression of recombinant proteins in milk of livestock at a large scale is very labour-intensive to be achieved with current transgenic animals, and usually seen as time-consuming, expensive and technically most challenging. Here we describe a convenient system for transient production of recombinant human growth hormone and its extensive use in recombinant protein production for therapeutic purposes. In this study, an adenoviral vector containing the GFP gene and hGH gene was constructed for direct infusion into the epithelium of mammary glands of goats via the teat canal during the period of natural lactation. Western-blot analysis of milk samples obtained from all of the viral-treated founders indicated that the recombinant hGH (rhGH) was secreted into the milk of the goats. The concentrations of rhGH in milk ranged from 0.6 to 2.4 mg/ml and lasted for more than 10 days during lactation. These data suggest that it is possible to produce larger amounts of recombinant human growth hormone in the milk of livestock animals by using replication-defective adenoviruses.

Operational characteristics of continuous renal replacement modalities used for critically ill patients with acute kidney injury

Renal replacement therapy (RRT) is required in a significant percentage of patients developing acute kidney injury (AKI) in an intensive care unit (ICU) setting. One of the foremost objectives of continuous renal replacement therapy (CRRT) is the removal of excess fluid and blood solutes that are retained as a consequence of decreased or absent glomerular filtration. Because prescription of CRRT requires goals to be set with regard to the rate and extent of both solute and fluid removal, a thorough understanding of the mechanisms by which solute and fluid removal occurs during CRRT is necessary. The following provides an overview of solute and water transfer during CRRT and this information is placed in the appropriate clinical context with a discussion of recent clinical trials assessing the relationship between CRRT dose and patient survival. Moreover, the differences between solute removal in CRRT and other dialysis modalities, especially sustained low-efficiency dialysis (SLED) and extended daily dialysis (EDD), along with the potential clinical implications are discussed.

Measurement of the elastic constants of a columnar SiC thin film

The technique of resonant ultrasound spectroscopy was used to measure the elastic properties of a polycrystalline cubic silicon carbide (3C-SiC) thin film. The film, grown on a silicon (100) substrate, was 1.69 microns thick with columnar crystalline grains and a (111) texture. The substrate with the film was placed between two transducers and the resonant frequencies were measured; measurements were repeated after selective, timed dry etching of the film, allowing a determination of the elastic constants of the film alone. The film elastic constants, c(11)=371 and c(12)=146 GPa, were within a few percent of the literature values (c(11)=386, c(12)=136 GPa) of crystalline 3C-SiC. However, the film elastic constant c(44), 111 GPa, was significantly smaller than the bulk literature value, 254 GPa. For the film, c44 approximately (c(11)-c(12))/2, indicating that, quite unlike a bulk 3C-SiC crystal, the thin film is elastically isotropic.

Population dynamics and maturation cycle of Camallanus cotti (Nematoda: Camallanidae) in the Chinese hooksnout carp Opsariichthys bidens (Osteichthyes: Cyprinidae) from a reservoir in China

The seasonal population dynamics and maturation cycle of the nematode Camallanus cotti in the posterior intestine of Chinese hooksnout carp Opsariichthys bidens have been studied in the Danjiangkou Reservoir of the Hubei Province in central China from September 2004 to November 2005. The overall prevalence, mean abundance and intensity of C. cotti among fish sampled (n=700 fish) were 47%, 2.29+/-12.38 (+/-S.D.) and 1-307 (average 4.89+/-17.74), respectively. The overall sexual ratio of female to male nematodes (excluding L3 and L4 juveniles) was 1.17:1. Statistical results showed weakly positive correlations between fish length and the number of nematodes per host. The dynamics of infection of the nematode exhibited significant seasonal pattern in changes in mean abundance. A similar pattern was found for changes in nematode prevalence, although this was not statistically significant. Higher levels of infection were observed among fish sampled in summer months and the lower in the winter. Neither the prevalence nor the abundance of the parasite was significantly different between male and female hosts. The pattern of frequency distribution of the parasite in the host was found to be over-dispersed throughout the sampling period. In addition, studies on the development and maturation of the parasite in O. bidens revealed that development (maturation), recruitment of the next generation, and reproduction may be continuous year-round, although reproduction may peak during the winter.

Expression of the nucleoprotein gene of rabies virus for use as a diagnostic reagent

The nucleoprotein (N) gene of rabies virus CTN strain, was cloned, sequenced and expressed in Escherichia coli as a fusion with maltose binding protein (MBP). The antigenicity of this recombinant MBP-N fusion protein was examined by Western blotting and enzyme linked immunosorbent assay (ELISA). Subsequently, an indirect ELISA was developed to detect rabies specific antibody levels. Using sera from naive and vaccinated animals the ELISA results were compared with virus neutralizing antibodies detected by a rapid fluorescent focus inhibition test (RFFIT). Neutralizing titres by RFFIT were found to correlate well with the OD values in the ELISA (r=0.9436) and the sensitivity and specificity of the ELISA were shown to be 93.4 and 100%, respectively. The data indicate that the recombinant MBP-N fusion protein can be expressed and isolated straightforwardly and may be useful as a safe and abundant source of antigen to monitor seropositivity in vaccinated canines.

IGF2 is critical for tumorigenesis by synovial sarcoma oncoprotein SYT-SSX1

Synovial sarcoma is an aggressive soft tissue tumor characterized by a specific chromosomal translocation between chromosome 18 and X. This translocation can generate a fusion transcript encoding SYT-SSX1, a transforming oncoprotein. We present evidence that SYT-SSX1 induces insulin-like growth factor II expression in fibroblast cells. SYT-SSX2, a fusion also frequently found in synovial sarcoma, is necessary for maintaining Igf2 expression in the synovial sarcoma cell line, and the increased IGF2 synthesis protects cells from anoikis and is required for tumor formation in vivo. We also found a loss of imprinting (LOI) for Igf2 in a limited number of primary synovial sarcomas despite demethylation of CpG dinucleotides critical for maintaining imprinting. These findings suggest that inhibition of the IGF2/IGF1-R signaling pathway may represent a significant therapeutic modality for treating synovial sarcoma.

Objective decomposition of the stress tensor in granular flows

A model for the stress tensor in granular flows [Volfson, Tsimring, and Aranson, Phys. Rev. Lett. 90, 254301 (2003)] is correctly generalized to an objective form that is independent of the coordinate system. The objective representation correctly models the isotropic and anisotropic parts of the stress tensor, whereas the original model for stress tensor components is dependent on the coordinate system. This general objective form of the model also relaxes the assumption in the original model that the principal axes of the granular stress tensor be coaxial with that of the "fluid" stress tensor. This generalization expands the applicability of the model to a wider class of granular flows. The objective representation is also useful in analyzing other models based on additive decomposition of the stress tensor in granular flows.

CD40 antisense oligonucleotide inhibition of trinitrobenzene sulphonic acid induced rat colitis

BACKGROUND

CD154/CD40 interactions play a pivotal role both in humoral and cellular immune responses. Their involvement in the pathogenesis of chronic inflammatory bowel disease (IBD) has been revealed by increased expression of CD40 and CD154 in the inflamed mucosa of patients and the therapeutic effects of anti-CD154 antibodies in experimental colitis. Because of adverse side effects however, the use of such antibodies in patients with IBD may be limited.

AIMS

An alternative approach to blocking CD154/CD40 interactions by employing a CD40 antisense oligonucleotide (ODN) was explored.

RESULTS

After sequencing of the rat CD40 gene, five antisense ODNs were designed, of which one (rAS3) effectively downregulated CD40 expression in rat vascular smooth muscle cells as well as the subsequent changes in gene expression in response to CD40 stimulation. The therapeutic potency of rAS3 was evaluated in the 2,4,6-trinitrobenzene sulphonic acid (TNBS) induced colitis model of the rat. Single intracolonic injection of a liposomal formulation of rAS3 either prior to or post colitis induction markedly suppressed the inflammatory reaction in these animals monitored both macroscopically and microscopically over one week, while application of a scrambled control ODN had no such effects. Moreover, reverse transcription-polymerase chain reaction analyses revealed reduced expression of vascular cell adhesion molecule 1, interleukin 12 p40, and monocyte chemoatractive protein 1 in the inflamed mucosa, which in turn may have contributed to the decrease in leucocyte infiltration judged by immunohistochemistry.

CONCLUSIONS

These results suggest that CD40 antisense ODNs effectively interfere with CD154/CD40 interactions in vivo and, therefore, may provide a novel approach to the treatment of patients with chronic IBD.