Non-viral FoxM1 gene delivery to hepatocytes enhances liver repopulation

Hepatocyte transplantation as a substitute strategy of orthotopic liver transplantation is being studied for treating end-stage liver diseases. Several technical hurdles must be overcome in order to achieve the therapeutic liver repopulation, such as the problem of insufficient expansion of the transplanted hepatocytes in recipient livers. In this study, we analyzed the application of FoxM1, a cell-cycle regulator, to enhance the proliferation capacity of hepatocytes. The non-viral sleeping beauty (SB) transposon vector carrying FoxM1 gene was constructed for delivering FoxM1 into the hepatocytes. The proliferation capacities of hepatocytes with FoxM1 expression were examined both in vivo and in vitro. Results indicated that the hepatocytes with FoxM1 expression had a higher proliferation rate than wild-type (WT) hepatocytes in vitro. In comparison with WT hepatocytes, the hepatocytes with FoxM1 expression had an enhanced level of liver repopulation in the recipient livers at both sub-acute injury (fumaryl acetoacetate hydrolase (Fah)^–/– mice model) and acute injury (2/3 partial hepatectomy mice model). Importantly, there was no increased risk of tumorigenicity with FoxM1 expression in recipients even after serial transplantation. In conclusion, expression of FoxM1 in hepatocytes enhanced the capacity of liver repopulation without inducing tumorigenesis. FoxM1 gene delivered by non-viral SB vector into hepatocytes may be a viable approach to promote therapeutic repopulation after hepatocyte transplantation.

JLab measurement of the 4He charge form factor at large momentum transfers

The charge form factor of 4He has been extracted in the range 29  fm(-2) ≤ Q2 ≤ 77  fm(-2) from elastic electron scattering, detecting 4He recoil nuclei and electrons in coincidence with the high resolution spectrometers of the Hall A Facility of Jefferson Lab. The measurements have uncovered a second diffraction minimum for the form factor, which was predicted in the Q2 range of this experiment. The data are in qualitative agreement with theoretical calculations based on realistic interactions and accurate methods to solve the few-body problem.

Investigation and analysis of contraceptive measures towards different reproductive-aged women in Yangzhou

OBJECTIVE

This study aims to retrospectively investigate the contraceptive methods of different reproductive-aged women in two different regions of Yangzhou, China, to understand the changes of the contraceptive methods, and to analyze the targeted improvements of future informed choices of contraception and birth control, and reduce the occurrence of the unintended pregnancies.

MATERIALS AND METHODS

This study included 13,407 and 20,876 married reproductive-aged women (MCW) that were chosen from a city downtown and a county-level city, respectively, for the group-organized random sampling questionnaire survey.

RESULTS

There was a significant urban-rural difference in the choice of contraceptive methods in different MCW. The female choices of contraception were single; the accessibility of contraceptive supplies, and personalized services could improve the implementation rate of long-term contraceptive measures. The cooperation of male contraceptive responsibility was related to the education levels and enhanced male-female communication.

CONCLUSIONS

It was very important for urban and rural women with different ages to choose different contraceptive measures, suggesting that these choices require the development of different educational models towards women of different ages and regions. The accessibility to various aspects of counseling and contraceptive measures should be strengthened, meanwhile male participation should also be promoted to prevent unwanted pregnancies and to reduce the health hazards related to sexual activities.

Involvement of miR-9/MCPIP1 axis in PDGF-BB-mediated neurogenesis in neuronal progenitor cells

Highly conserved microRNA-9 (miR-9) has a critical role in various cellular processes including neurogenesis. However, its regulation by neurotropins that are known to mediate neurogenesis remains poorly defined. In this study, we identify platelet-derived growth factor-BB (PDGF-BB)-mediated upregulation of miR-9, which in turn downregulates its target gene monocyte chemotactic protein-induced protein 1 (MCPIP1), as a key player in modulating proliferation, neuronal differentiation as well as migration of neuronal progenitor cells (NPCs). Results indicate that miR-9-mediated NPC proliferation and neuronal differentiation involves signaling via the nuclear factor-kappa B (NF-κB) and cAMP response element-binding protein (CREB) pathways, and that NPC migration involves CREB but not the NF-κB signaling. These findings thus suggest that miR-9-mediated downregulation of MCPIP1 acts as a molecular switch regulation of neurogenesis.

The influence of food on the pharmacokinetics of amlodipine and losartan after single-dose of its compound tablets in healthy chinese subjects

We aim to identify the effects of food on the pharmacokinetics (PK) of amlodipine, losartan and losartan's active metabolite (EXP3174) after oral administration of the Compound Amlodipine Tablets with single dose in healthy Chinese subjects. 12 subjects took the compounds (10 mg/100 mg, amlodipine/losartan) at the conditions of a high-fat breakfast and an overnight fast with a washout period of 14 days. Plasma samples were obtained at scheduled time, and determined by HPLC-MS/MS for the concentrations of amlodipine and HPLC-MS for the concentrations of losartan and EXP3174, respectively. PK parameters were calculated using Software Drug and Statistics (Version 2.0). When tablets were co-administered with food, there was no significant difference of AUC for amlodipine and losartan, but the AUC of EXP3174 was reduced by 19.1%. Meanwhile, the Cmax of amlodipine, losartan and EXP3174 were reduced by 11.4%, 20.0% and 41.4%, and the Tmax of losartan and EXP3174 were 1.3 and 1.8 h longer, respectively. No significant difference was found at t1/2 following food intake. In conclusion, the Compound Amlodipine Tablets, are affected by food administration by reducing the AUC of EXP3174. It is thus suggested that the Compound Amlodipine Tablets should be administered 1 h before or 2 h after meal.

DNA barcoding of populations of Fallopia multiflora, an indigenous herb in China

Fallopia multiflora, locally known as Heshouwu, is one of the most important and widely used Chinese medicinal herbs. However, there is still considerable confusion concerning its different provenances. DNA barcoding is a recent aid to taxonomic identification and uses a short standardized DNA region to discriminate plant species. We assessed the applicability of 4 candidate DNA barcodes (matK, rbcL, psbA-trnH, and ITS2) to identify populations of F. multiflora. To our knowledge, this is the first attempt involving the plant kingdom to apply DNA barcoding at a level lower than species. Four DNA loci (matK, rbcL, psbA-trnH, and ITS2) of 105 samples, including the wild F. multiflora distributed in 17 provinces of China and 4 cultivated F. multiflora lines, were amplified by PCR and sequenced. The 4 loci were evaluated by PCR amplification for sequence quality, extent of genetic divergence, DNA barcoding gap, and the ability to discriminate between populations by BLAST1 and Nearest Distance. We found that psbA-trnH was the best barcode, with significant inter-population variability and best potential for identifying F. multiflora. The combination of loci gave better performance for distinguishing populations than a single locus. We recommend using matK + rbcL + psbA-trnH + ITS2 or psbA-trnH alone for this species. This research demonstrates the utility of DNA barcoding for geoherbalism identifications.

Hard two-body photodisintegration of 3He

We have measured cross sections for the γ(3)He → pd reaction at photon energies of 0.4-1.4 GeV and a center-of-mass angle of 90°. We observe dimensional scaling above 0.7 GeV at this center-of-mass angle. This is the first observation of dimensional scaling in the photodisintegration of a nucleus heavier than the deuteron.

miR-27a regulates endothelial differentiation of breast cancer stem like cells

Recent studies suggested that cancer stem cells (CSCs) are capable of differentiating into endothelial cells and tumor endothelium may be derived from CSCs. But the mechanism remains unclear. We showed that vascular endothelial growth factor (VEGF) induced the expression of endothelial markers in breast cancer stem like cells (BCSLCs). In addition, the VEGF-treated BCSLCs formed capillary structure in matrigel and released vWF upon histamine treatment. The miR-27a expression was significantly increased in VEGF-treated BCSLCs. Antagonizing miR-27a by miR-27a anti-sense oligos (ASOs) in VEGF-treated BCSLCs led to decreased endothelial markers and function, while increasing miR-27a in BCSLCs resulted in enhanced endothelial properties. VEGF enhanced the transcription of miR-27a by increasing RUNX1 binding to miR-27a promoter. Increased miR-27a paralleled the reduced expression of ZBTB10, a known miR-27a target. Both expression of miR-27a and knockdown of ZBTB10 in BCSLCs promoted in vivo angiogenesis and tumor metastasis. Further, we demonstrated that VEGF-treated BCSLCs secreted more endogenous VEGF compared with undifferentiated BCSLCs. Thus, miR-27a promotes angiogenesis by mediating endothelial differentiation of BCSLCs and it may be a new target for anti-angiogenesis cancer therapy.

Determining the depth of insertion of dynamically invisible membrane peptides by gel-phase ¹H spin diffusion heteronuclear correlation NMR

Solid-state NMR determination of the depth of insertion of membrane peptides and proteins has so far utilized (1)H spin diffusion and paramagnetic relaxation enhancement experiments, which are typically conducted in the liquid-crystalline phase of the lipid bilayer. For membrane proteins or peptide assemblies that undergo intermediate-timescale motion in the liquid-crystalline membrane, these approaches are no longer applicable because the protein signals are broadened beyond detection. Here we show that the rigid-solid HETCOR experiment, with an additional spin diffusion period, can be used to determine the depth of proteins in gel-phase lipid membranes, where the proteins are immobilized to give high-intensity solid-state NMR spectra. Demonstration on two membrane peptides with known insertion depths shows that well-inserted peptides give rise to high lipid cross peak intensities and low water cross peaks within a modest spin diffusion mixing time, while surface-bound peptides have higher water than lipid cross peaks. Furthermore, well-inserted membrane peptides have nearly identical (1)H cross sections as the lipid chains, indicating equilibration of the peptide and lipid magnetization. Using this approach, we measured the membrane topology of the α-helical fusion peptide of the paramyxovirus, PIV5, in the anionic POPC/POPG membrane, in which the peptide undergoes intermediate-timescale motion at physiological temperature. The gel-phase HETCOR spectra indicate that the α-helical fusion peptide is well inserted into the POPC/POPG bilayer, spanning both leaflets. This insertion motif gives insight into the functional role of the α-helical PIV5 fusion peptide in virus-cell membrane fusion.

MicroRNA-181b expression in prostate cancer tissues and its influence on the biological behavior of the prostate cancer cell line PC-3

We examined microRNA-181b (miRNA) expression in prostate cancer tissues and its effect on the prostate cancer cell line PC-3. Tissues from 27 cases of prostate cancer and 30 samples of normal human prostate were collected by surgical removal. Total miRNA was extracted, and the relative expression of miR-181b was quantified using RT-PCR. miR-181b ASO was transfected into prostate cancer PC-3 cells. miR-181b expression in transfected and non-transfected cells was measured using RT-PCR. Changes in cell apoptosis were measured using flow cytometry. MTT and cell growth curve methods were used to assess the influence of miR-181b expression on cell proliferation. The changes in cell invasive ability in vitro were detected using the Transwell chamber method. miR-181b was up-regulated in the prostate cancer tissues compared with the normal prostate samples. It was down-regulated after miR-181b ASO transfection into the prostate cancer PC-3 cells. Down-regulation of miR-181b in the PC-3 cell induced apoptosis, inhibited proliferation, and depressed invasion of PC-3 cells in vitro. As miR-181b is over-expressed in prostate cancer, its down-regulation could have potential as gene therapy for prostate cancer by inducing apoptosis, inhibiting proliferation and depressing invasion by cancer cells.

High-resolution calorimetric study of phase transitions in chiral smectic-C liquid crystalline phases

We carried out an improved characterization of phase transitions among chiral smectic-C subphases observed for various antiferroelectric liquid crystals by precise heat capacity measurements. It was found that the phase transitions are intrinsically first order exhibiting a remarkable heat anomaly which involves little pretransitional thermal fluctuation and a finite thermal hysteresis. On the other hand, we also noticed that the critical point of the smectic-C(α)(*)-smectic-C* transition is induced by the destabilization of the smectic-C(α)(*) phase which couples with the fluctuation associated with the smectic-A-smectic-C(α)(*) phase transition.

Exosome-mediated shuttling of microRNA-29 regulates HIV Tat and morphine-mediated neuronal dysfunction

Neuronal damage is a hallmark feature of HIV-associated neurological disorders (HANDs). Opiate drug abuse accelerates the incidence and progression of HAND; however, the mechanisms underlying the potentiation of neuropathogenesis by these drugs remain elusive. Opiates such as morphine have been shown to enhance HIV transactivation protein Tat-mediated toxicity in both human neurons and neuroblastoma cells. In the present study, we demonstrate reduced expression of the tropic factor platelet-derived growth factor (PDGF)-B with a concomitant increase in miR-29b in the basal ganglia region of the brains of morphine-dependent simian immunodeficiency virus (SIV)-infected macaques compared with the SIV-infected controls. In vitro relevance of these findings was corroborated in cultures of astrocytes exposed to morphine and HIV Tat that led to increased release of miR-29b in exosomes. Subsequent treatment of neuronal SH-SY5Y cell line with exosomes from treated astrocytes resulted in decreased expression of PDGF-B, with a concomitant decrease in viability of neurons. Furthermore, it was shown that PDGF-B was a target for miR-29b as evidenced by the fact that binding of miR-29 to the 3′-untranslated region of PDGF-B mRNA resulted in its translational repression in SH-SY5Y cells. Understanding the regulation of PDGF-B expression may provide insights into the development of potential therapeutic targets for neuronal loss in HIV-1-infected opiate abusers.

Measurement of the neutron radius of 208Pb through parity violation in electron scattering

We report the first measurement of the parity-violating asymmetry A(PV) in the elastic scattering of polarized electrons from 208Pb. A(PV) is sensitive to the radius of the neutron distribution (R(n)). The result A(PV)=0.656±0.060(stat)±0.014(syst) ppm corresponds to a difference between the radii of the neutron and proton distributions R(n)-R(p)=0.33(-0.18)(+0.16) fm and provides the first electroweak observation of the neutron skin which is expected in a heavy, neutron-rich nucleus.

New precision limit on the strange vector form factors of the proton

The parity-violating cross-section asymmetry in the elastic scattering of polarized electrons from unpolarized protons has been measured at a four-momentum transfer squared Q2 = 0.624  GeV2 and beam energy E(b) = 3.48  GeV to be A(PV) = -23.80 ± 0.78(stat) ± 0.36(syst) parts per million. This result is consistent with zero contribution of strange quarks to the combination of electric and magnetic form factors G(E)(s) + 0.517G(M)(s) = 0.003 ± 0.010(stat) ± 0.004(syst) ± 0.009(ff), where the third error is due to the limits of precision on the electromagnetic form factors and radiative corrections. With this measurement, the world data on strange contributions to nucleon form factors are seen to be consistent with zero and not more than a few percent of the proton form factors.

Beam-target double-spin asymmetry A{LT} in charged pion production from deep inelastic scattering on a transversely polarized {3}He target at 1.4<Q{2}<2.7 GeV{2}

We report the first measurement of the double-spin asymmetry A{LT} for charged pion electroproduction in semi-inclusive deep-inelastic electron scattering on a transversely polarized {3}He target. The kinematics focused on the valence quark region, 0.16<x<0.35 with 1.4<Q{2}<2.7  GeV{2}. The corresponding neutron A{LT} asymmetries were extracted from the measured {3}He asymmetries and proton over {3}He cross section ratios using the effective polarization approximation. These new data probe the transverse momentum dependent parton distribution function g{1T}{q} and therefore provide access to quark spin-orbit correlations. Our results indicate a positive azimuthal asymmetry for π{-} production on {3}He and the neutron, while our π{+} asymmetries are consistent with zero.

Pseudoangiosarcomatous squamous cell carcinoma of the lung

Pulmonary pseudoangiosarcomatous squamous cell carcinoma (PSCC) is a rare aggressive variant of squamous cell carcinoma. Histopathologically, PSCC is characterized by interanastomosing cords and channels, lined by atypical cells, with spaces containing erythrocytes or floating tumour cells. PSCC mimics angiosarcoma, so careful attention should be paid to immunohistochemical differences. Two PSCC cases are described here: in a 79-year-old male, bronchoscopy revealed mucosal swelling and hypertrophy and an adrenal mass was found 1 month later; in a 76-year-old male, computed tomography revealed rib destruction due to a non-calcified soft-tissue tumour and, although the tumour resembled an angiosarcoma, endothelial markers were negative and cytokeratin and p63 markers were positive. Immunohistochemical analyses may be helpful in establishing an accurate diagnosis. PSCC had a progressive course in both patients, who died ≤ 3 months postdiagnosis.

Distinctive thermal behavior and nanoscale phase separation in the heterogeneous liquid-crystal B4 matrix of bent-core molecules

By means of high-resolution calorimetry, we studied thermodynamic properties of the liquid-crystal B(4) phase where bent-core molecules form a helical nanofilament structure. Distinctive thermal behavior characterizing the growth process of the B(4) phase was obtained in undergoing the phase transition with many sharp peaks, indicating a highly heterogeneous structure. It has been demonstrated that such unusual behavior is commonly seen for two types of rodlike molecules as well as for various mixture compositions. We speculate that mixture systems involve a nanoscale phase-separated structure due to the remarkable aggregation effect in the bent-core molecules and that the helical nanofilament structure independently grows in the isotropic state of rodlike molecules. We also propose that the asymmetry in viscoelastic property plays a role in yielding unusual behavior.

AV-65, a novel Wnt/β-catenin signal inhibitor, successfully suppresses progression of multiple myeloma in a mouse model

Multiple myeloma (MM) is a malignant neoplasm of plasma cells. Although new molecular targeting agents against MM have been developed based on the better understanding of the underlying pathogenesis, MM still remains an incurable disease. We previously demonstrated that β-catenin, a downstream effector in the Wnt pathway, is a potential target in MM using RNA interference in an in vivo experimental mouse model. In this study, we have screened a library of more than 100 000 small-molecule chemical compounds for novel Wnt/β-catenin signaling inhibitors using a high-throughput transcriptional screening technology. We identified AV-65, which diminished β-catenin protein levels and T-cell factor transcriptional activity. AV-65 then decreased c-myc, cyclin D1 and survivin expression, resulting in the inhibition of MM cell proliferation through the apoptotic pathway. AV-65 treatment prolonged the survival of MM-bearing mice. These findings indicate that this compound represents a novel and attractive therapeutic agent against MM. This study also illustrates the potential of high-throughput transcriptional screening to identify candidates for anticancer drug discovery.

Single spin asymmetries in charged pion production from semi-inclusive deep inelastic scattering on a transversely polarized 3He Target at Q2 = 1.4-2.7 GeV2

We report the first measurement of target single spin asymmetries in the semi-inclusive (3)He(e,e'π(±))X reaction on a transversely polarized target. The experiment, conducted at Jefferson Lab using a 5.9 GeV electron beam, covers a range of 0.16 < x < 0.35 with 1.4 < Q(2) < 2.7 GeV(2). The Collins and Sivers moments were extracted from the azimuthal angular dependence of the measured asymmetries. The π(±) Collins moments for (3)He are consistent with zero, except for the π(+) moment at x = 0.35, which deviates from zero by 2.3σ. While the π(-) Sivers moments are consistent with zero, the π(+) Sivers moments favor negative values. The neutron results were extracted using the nucleon effective polarization and measured cross section ratios of proton to (3)He, and are largely consistent with the predictions of phenomenological fits and quark model calculations.

Effect of mechanical loading on electrical conductivity in porcine TMJ discs

The objective of this study was to examine the impact of mechanical loading on solute transport in porcine temporomandibular joint (TMJ) discs using the electrical conductivity method. The electrical conductivity, as well as ion diffusivity, of TMJ discs was determined under confined compression with 3 strains in 5 disc regions. The average electrical conductivity over the 5 regions (mean ± SD) at 0% strain was 3.10 ± 0.68 mS/cm, decreased to 2.76 ± 0.58 mS/cm (-11.0%) at 10% strain, and 2.38 ± 0.55 mS/cm (-22.2%) at 20% compressive strain. Correspondingly, the average relative ion diffusivity (mean ± SD) at 0% strain was 0.273 ± 0.055, decreased to 0.253 ± 0.048 (-7.3%) at 10% strain, and 0.231 ± 0.048 (-15.4%) at 20% compressive strain. These results indicated that compressive strain impeded solute transport in the TMJ disc. Furthermore, our results showed that the transport properties of TMJ discs were region-dependent. The electrical conductivity and ion diffusivity in the anterior region were significantly higher than in the posterior region. This regional difference is likely due to the significant differences of tissue hydration between these 2 regions. This study provides important insight into the electrical and solute transport behaviors in TMJ discs under mechanical loading and aids in the understanding of TMJ pathophysiology related to tissue nutrition.

Measurements of the electric form factor of the neutron up to Q2=3.4 GeV2 using the reaction 3He(e,e'n)pp

The electric form factor of the neutron was determined from studies of the reaction 3He(e,e'n)pp in quasielastic kinematics in Hall A at Jefferson Lab. Longitudinally polarized electrons were scattered off a polarized target in which the nuclear polarization was oriented perpendicular to the momentum transfer. The scattered electrons were detected in a magnetic spectrometer in coincidence with neutrons that were registered in a large-solid-angle detector. More than doubling the Q2 range over which it is known, we find G(E)(n)=0.0236±0.0017(stat)±0.0026(syst), 0.0208±0.0024±0.0019, and 0.0147±0.0020±0.0014 for Q(2)=1.72, 2.48, and 3.41 GeV2, respectively.

Paracrine signals from mesenchymal cell populations govern the expansion and differentiation of human hepatic stem cells to adult liver fates

The differentiation of embryonic or determined stem cell populations into adult liver fates under known conditions yields cells with some adult-specific genes but not others, aberrant regulation of one or more genes, and variations in the results from experiment to experiment. We tested the hypothesis that sets of signals produced by freshly isolated, lineage-dependent mesenchymal cell populations would yield greater efficiency and reproducibility in driving the differentiation of human hepatic stem cells (hHpSCs) into adult liver fates. The subpopulations of liver-derived mesenchymal cells, purified by immunoselection technologies, included (1) angioblasts, (2) mature endothelia, (3) hepatic stellate cell precursors, (4) mature stellate cells (pericytes), and (5) myofibroblasts. Freshly immunoselected cells of each of these subpopulations were established in primary cultures under wholly defined (serum-free) conditions that we developed for short-term cultures and were used as feeders with hHpSCs. Feeders of angioblasts yielded self-replication, stellate cell precursors caused lineage restriction to hepatoblasts, mature endothelia produced differentiation into hepatocytes, and mature stellate cells and/or myofibroblasts resulted in differentiation into cholangiocytes. Paracrine signals produced by the different feeders were identified by biochemical, immunohistochemical, and quantitative reverse-transcription polymerase chain reaction analyses, and then those signals were used to replace the feeders in monolayer and three-dimensional cultures to elicit the desired biological responses from hHpSCs. The defined paracrine signals were proved to be able to yield reproducible responses from hHpSCs and to permit differentiation into fully mature and functional parenchymal cells.

CONCLUSION

Paracrine signals from defined mesenchymal cell populations are important for the regulation of stem cell populations into specific adult fates; this finding is important for basic and clinical research as well as industrial investigations.

Enhanced effect of soluble transforming growth factor-beta receptor II and IFN-gamma fusion protein in reversing hepatic fibrosis

Objective

To examine the in vivo anti-fibrotic effect of rat soluble transforming growth factor β receptor II (RsTβRII) and IFN-γ fusion protein (RsTβRII-IFN-γ) in rat hepatic fibrosis model.

Methods

Model rats were divided into five groups and treated i.m. for 8 weeks: 1) fibrotic model group (each rat, 100 μl of 0.9% NaCl day^-1); 2) RsTβRII-IFN-γ treatment group (each rat, 0.136 mg· day^-1); 3) IFN-γ treatment group (each rat, 7.5 MU· day^-1); 4) RsTβRII treatment group (each rat, 0.048 mg· day^-1); and 5) mixture of IFN-γ and RsTβRII treatment group (each rat, IFN-γ 7.5 MU· day^-1+ RsTβRII 0.048 mg· day^-1). After treatment, hepatic fibrogenesis was evaluated by histopathological analysis and measurement of collagen III, α-smooth muscle actin (α-SMA), TGF-β1, TGF-βRII and their mRNA.

Results

Immunohistochemistry, Western blot and real-time RT-PCR showed that RsTβRII-IFN-γ treatment significantly inhibited liver expression of collagen III, α-SMA, TGF-β1 and TGF-βRII at both protein and mRNA levels. Histopathological analysis also showed that the enhanced anti-fibrotic effects were achieved in model rats treated with RsTβRII-IFN-γ.

Conclusion

Our results confirmed that RsTβRII-IFN-γ has the enhanced effects in reversing hepatic fibrosis.

Time-resolved x-ray diffraction and calorimetric studies at low scan rates: II. On the fine structure of the phase transitions in hydrated dipalmitoylphosphatidylethanolamine

The phase transitions of dipalmitoylphosphatidylethanolamine (DPPE) in excess water have been examined by low-angle time-resolved x-ray diffraction and calorimetry at low scan rates. The lamellar subgel/lamellar liquid-crystalline (L(c) --> L(alpha)), lamellar gel/lamellar liquid-crystalline (L(beta) --> L(alpha)), and lamellar liquid-crystalline/lamellar gel (L(alpha) --> L(beta)) phase transitions proceed via coexistence of the initial and final phases with no detectable intermediates at scan rates 0.1 and 0.5 degrees C/min. At constant temperature within the region of the L(beta) --> L(alpha) transition the ratio of the two coexisting phases was found to be stable for over 30 min. The state of stable phase coexistence was preceded by a 150-s relaxation taking place at constant temperature after termination of the heating scan in the transition region. While no intermediate structures were present in the coexistence region, a well reproducible multipeak pattern, with at least four prominent heat capacity peaks separated in temperature by 0.4-0.5 degrees C, has been observed in the cooling transition (L(alpha) --> L(beta)) by calorimetry. The multipeak pattern became distinct with an increase of incubation time in the liquid-crystalline phase. It was also clearly resolved in the x-ray diffraction intensity versus temperature plots recorded at slow cooling rates. These data suggest that the equilibrium state of the L(alpha) phase of hydrated DPPE is represented by a mixture of domains that differ in thermal behavior, but cannot be distinguished structurally by x-ray scattering.

Metastable ripple phase of fully hydrated dipalmitoylphosphatidylcholine as studied by small angle x-ray scattering

Fully hydrated dipalmitoylphosphatidylcholine (DPPC) undergoes liquid crystalline to metastable P(beta), phase transition in cooling. A small angle x-ray scattering study has been performed for obtaining further evidence about the structure of this phase. From a high-resolution observation of x-ray diffraction profiles, a distinct multipeak pattern has become obvious. Among them the (01) reflection in the secondary ripple structure is identified clearly. There are peaks assigned straightforwardly to (10) and (20) reflections in the primary ripple structure and peaks assigned to (10) and (20) reflections in the secondary ripple structure. Therefore the multipeak pattern is due to superposition of the reflections cause by the primary and secondary ripple structures. The lattice parameters are estimated as follows: for the primary ripple structure a = 7.09 nm, b = 13.64 nm, and gamma = 95 degrees , and for the secondary ripple structure a = 8.2 nm, b = 26.6 nm, and gamma = 90 degrees . The lattice parameters thus obtained for the secondary ripple structure are not conclusive, however. The hydrocarbon chains in the primary ripple structure have been reported as being tilted against the bilayer plane and, on the other hand, the hydrocarbon chains in the secondary ripple structure are likely to be perpendicular to the bilayer plane. This fact seems to be related to a sequential mechanism of phase transitions. On heating from the L(beta), phase where the hydrocarbon chains are tilted the primary ripple structure having tilted hydrocarbon chains takes place and on cooling from the L(alpha) phase where the hydrocarbon chains are not tilted the secondary ripple structure with untilted chains tends to be stabilized. It appears that the truly metastable ripple phase is expressed by the second ripple structure although in the course of the actual cooling transition both the secondary and primary ripple structures form and coexist.

Time-resolved x-ray diffraction and calorimetric studies at low scan rates: I. Fully hydrated dipalmitoylphosphatidylcholine (DPPC) and DPPC/water/ethanol phases

The phase transitions in fully hydrated dipalmitoylphosphatidylcholine (DPPC) and DPPC/water/ethanol phases have been studied by lowangle time-resolved x-ray diffraction under conditions similar to those employed in calorimetry (scan rates 0.05-0.5 degrees C/min and uniform temperature throughout the samples). This approach provides more adequate characterization of the equilibrium transition pathways and allows for close correlations between structural and thermodynamic data. No coexistence of the rippled gel (P(beta')) and liquid-crystalline (L(alpha)) phases was found in the main transition of DPPC; rather, a loss of correlation in the lamellar structure, observed as broadening of the lamellar reflections, takes place in a narrow temperature range of approximately 100 mK at the transition midpoint. Formation of a long-living metastable phase, denoted by P(beta')(mst), differing from the initial P(beta') was observed in cooling direction by both x-ray diffraction and calorimetry. No direct conversion of P(beta')(mst) into P(beta') occurs for over 24 h but only by way of the phase sequence P(beta')(mst) --> L(beta') --> P(beta'). According to differential scanning calorimetry (DSC), the enthalpy of the P(beta')(mst)-L(alpha) transition is by approximately 5% lower than that of the P(beta')-L(alpha) transition. The effects of ethanol (Rowe, E. S. 1983. Biochemistry. 22:3299-3305; Simon, S. A., and T. J. McIntosh. 1984. Biochim. Biophys. Acta 773:169-172) on the mechanism and reversibility of the DPPC main transition were clearly visualized. At ethanol concentrations inducing formation of interdigitated gel phase, the main transition proceeds through a coexistence of the initial and final phases over a finite temperature range. During the subtransition in DPPC recorded at scan rate 0.3 degrees C/min, a smooth monotonic increase of the lamellar spacing from its subgel (L(c)) to its gel (L(beta')) phase value takes place. The width of the lamellar reflections remains unchanged during this transformation. This provides grounds to propose a "sequential" relaxation mechanism for the subgel-gel transition which is not accompanied by growth of domains of the final phase within the initial one.

Pregnane X receptor suppresses proliferation and tumourigenicity of colon cancer cells

BACKGROUND

Pregnane X receptor (PXR) is a nuclear receptor that regulates the metabolism and disposition of various xenobiotics and endobioitics. We investigated a novel PXR function in regulating colon tumourigenesis in this study.

METHODS

Histochemistry, transfection, cell proliferation assay, anchorage-alpha-dependent assay, xenograft, immunohistochemistry, immunofluorescence flow cytometry.

RESULTS

Using histochemistry analysis, we found that PXR expressions were lost or greatly diminished in many colon tumours. Ectopic expression of human PXR through stable transfection of PXR into colon cancer cell line HT29 significantly inhibited cell proliferation as determined by cell proliferation assay and anchorage-independent assay. Pregnane X receptor suppressed significantly HT29 xenograft tumour growth in nude mice compared with control (310+/-6.2 vs 120+/-6 mg, P<0.01). Immunohistochemistry and immunofluorescence analysis of Ki-67 on excised xenograft tumour tissues showed that PXR inhibited cancer cell proliferation. Furthermore, expressions of PXR and Ki-67 were mutually exclusive. The flow cytometry analysis indicated that PXR caused G(0)/G(1) cell-cycle arrest. p21(WAF1/CIP1) expression was markedly elevated whereas E2F1 expression was inhibited by PXR.

CONCLUSION

PXR inhibits the proliferation and tumourigenicity of colon cancer cells by controlling cell cycle at G(0)/G(1) cell phase by regulating p21(WAF1/CIP1) and E2F/Rb pathways.

Mir-30 reduction maintains self-renewal and inhibits apoptosis in breast tumor-initiating cells

Accumulating evidence indicates that a sub-population of cancer cells with stem-like properties, termed tumor-initiating cells (T-ICs), exist in many different kinds of malignancies, which have a pivotal role in tumorigenesis, tumor progression, metastasis and post-treatment relapse. However, how the stem-like properties of T-ICs are regulated remains obscure. Our previous study showed that reduction of let-7 microRNA (miRNA) in breast tumor-initiating cells (BT-ICs) contributes to the maintenance of their self-renewal capacity and undifferentiated status. In this study we show the effect of mir-30 reduction on the stem-like features of BT-ICs. Similar to let-7, mir-30 is reduced in BT-ICs, and the protein level of Ubc9 (ubiquitin-conjugating enzyme 9) and ITGB3 (integrin beta3), the target genes of mir-30, is markedly upregulated. Enforced constitutive expression of mir-30 in BT-ICs inhibits their self-renewal capacity by reducing Ubc9, and induces apoptosis through silencing ITGB3. On the contrary, blocking the miRNA with a specific antisense oligonucleotide (ASO) in differentiated breast cancer cells revived their self-renewal capacity. Furthermore, ectopic expression of mir-30 in BT-IC xenografts reduces tumorigenesis and lung metastasis in nonobese diabetic/severe combined immunodeficient mice, whereas blocking mir-30 expression enhances tumorigenesis and metastasis. Together, our data suggest mir-30 as one of the important miRNAs in regulating the stem-like features of T-ICs.

No sex-specific markers detected in bluegill sunfish Lepomis macrochirus by AFLP

The amplified fragment-length polymorphism (AFLP) technique was used to identify sex-specific markers in bluegill sunfish. A total of 12 835 loci were produced by 256 primer combinations, of which nine (0.73 per thousand) exhibited presumed sex-associated amplifications in the pooled samples; however, none of which revealed sex specificity upon individual evaluation.

Irritant and adjuvant effects of gaseous formaldehyde on the ovalbumin-induced hyperresponsiveness and inflammation in a rat model

BACKGROUND

Formaldehyde (FA) is a common indoor air pollutant that can cause asthma in people experiencing long-term exposure. While FA and other man-made chemicals contribute to the stimulation of asthma in the general population, the underlying molecular pathogenesis of this relationship is not yet well understood.

OBJECTIVE

To explore FA as an irritant for the onset of asthma and as an adjuvant for the induction of allergy.

METHODS

In the present study, 40 Wistar rats in five experimental groups were exposed to: (i) saline; (ii) ovalbumin (OVA); (iii) OVA + FA at 417 ppb; (iv) OVA + FA at 2500 ppb; and (v) FA at 2500 ppb. Current and prior occupational exposure limits in China were established at 417 ppb and 2500 ppb, respectively. Gaseous FA was administrated to the animals for 6 h/day before and during OVA immunization or saline treatment. Measured outcomes included in situ lung function analysis, cytokine measurement, and histological changes in the rat lungs.

RESULTS

The airway reactivity, lung histological changes, pulmonary interleukin-4 secretion, and eosinophil infiltration in the OVA and FA exposed rats were significantly higher after gaseous FA exposures of 417 and 2500 ppb. While FA exposure alone did not induce significant structural changes to the airway, and the rate of inflammatory cell infiltration was the same as for the control group, pulmonary levels of interferon-gamma were significantly elevated in the exposed rats.

CONCLUSIONS

FA may be an irritant as well as serve as an adjuvant for the onset of asthma or asthma-like symptoms.

Proportion of Tumor Initiating Cells Contributes to Chemotherapeutic Resistance of Breast Cancers

Background: The mechanisms determining chemotherapeutic resistance of breast cancers are rather complicated with a variety of molecules involved. While targeting one single molecule or one signaling pathway are not sufficient to reverse chemo-resistance. Therefore, it is more important to identify and eliminate the subpopulations of tumor cells that are resistant to chemotherapy. Recently, accumulating evidence demonstrates that a wide variety of malignancies may be driven by a small subset of “tumor-initiating cells (T-ICs) displays a variety of drug-resisting mechanisms. Nevertheless, it remains obscure whether the proportion of breast tumor initiating cells (BT-ICs) correlates with chemotherapeutic sensitivity of breast cancers, and whether targeting BT-ICs may help to reverse chemo-resistance in the malignancy.Material and Methods: Using immunohistochemistry, we tested the expression level of ALDH1 in 192 human breast cancer samples before underwent neoadjuvant chemotherapy and analyzed the relationship between the ALDH1 level and clinical pathological features including clinical response and disease free survival (DFS). We tested the proportion of CD44+/CD24-, ALDH1+ and side population in primary cancer cells, wide type MCF7 and Adriamycin resistant (AdrR) MCF-7 by FACS. Compared the mammosphere formations in suspension culture. We further tested the drug sensitivity after treated with 1UM Lapatinib in AdrR MCF-7 mammospheric cells by MTT and AnnexinV staining. Results: In all 192 cases, there were 19.79% (38 of 192) cases with high ALDH1 expression (&gt;20% positive cancer cells) compared to 80.21% (154 of 192) cases with low expression (≤20% positives cells). The clinical response (PR and cCR) was only 52.63%% (20 of 38) in patients with high ALDH1 expression compared with 81.17% (125 of 154) in patients with low ALDH1 expression (x2=15.926; P=0.000). Patients with low ALDH1expression survived significantly longer than those with high ALDH1 expression (P = 0.006). In primary cancer cells, the percentage of ALDH1+ and CD44+/CD24-cells were up to 8.72% ±3.73% and 36% ±7.9% in the PD samples respectively, whereas only 1.42%±1.63% and 3.17 ±0.45% in PR samples (p=0.037 and 0.018). Moreover, mammosphere formation of primary human breast cancer cells was 10-20 fold higher in PD samples than in PR samples (p=0.01). Then we compared the proportion of BT-ICs between two breast cancer cell lines. The mammoshpere formation rate of the AdrR MCF-7 increased to 9.1%±1.01% compared with 1.03%±0.15% in the parent MCF-7 breast cancer cell (p=0.0046), meanwhile, the percentage of CD44+/CD24- cells was much higher in the AdrR MCF-7 cells(64.85%±1.3% vs than 1.3%±0.1%,p=0.01), the proportion of ALDH1+ cells was 15.9%±1.5% to 2.7%±0.3% (p=0.01),as well as the percentage of side population was 10.8%±1.4% to.0.25%±0.05% (p=0.001).After treated with Lapatinib, the sensitivity of passaged mammospheric AdrR MCF-7 cells to chemotherapy increased in the cell viability assay, while the dead cells increased from 50% ±2.8% to 75%±6.5% tested by FACS under chemotherapy pressure (p=012).Conclusion: Proportion of tumor initiating cells contributes to chemotherapeutic resistance of breast cancers.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 503.

TRPC channel-mediated neuroprotection by PDGF involves Pyk2/ERK/CREB pathway

Platelet-derived growth factor-BB (PDGF) has been reported to provide tropic support for neurons in the central nervous system. The protective role of PDGF on dopaminergic neurons, especially in the context of HIV-associated dementia (HAD), however, remains largely unknown. Here, we show that exogenous PDGF was neuroprotective against toxicity induced by HIV-1 Tat in primary midbrain neurons. Furthermore, we report the involvement of transient receptor potential canonical (TRPC) channels in PDGF-mediated neuroprotection. TRPC channels are Ca(2+)-permeable, nonselective cation channels with a variety of physiological functions. Blocking TRPC channels with either a blocker or short-interfering RNAs (specific for TRPC 5 and 6) in primary neurons resulted in suppression of both PDGF-mediated neuroprotection as well as elevations in intracellular Ca(2+). PDGF-mediated neuroprotection involved parallel but distinct ERK/CREB and PI3K/Akt pathways. TRPC channel blocking also resulted in suppression of PDGF-induced Pyk2/ERK/CREB activation, but not Akt activation. Relevance of these findings in vivo was further corroborated by intrastriatal injections of PDGF and HIV-1 Tat in mice. Administration of PDGF was able to rescue the dopaminergic neurons in the substantia nigra from Tat-induced neurotoxicity. This effect was attenuated by pre-treatment of mice with the TRP blocker, thus underscoring the novel role of TRPC channels in the neuroprotection mediated by PDGF.