PTP inhibitor IV protects JNK kinase activity by inhibiting dual-specificity phosphatase 14 (DUSP14)

Protein phosphorylation plays critical roles in the regulation of protein activity and cell signaling. The level of protein phosphorylation is controlled by protein kinases and protein tyrosine phosphatases (PTPs). Disturbance of the equilibrium between protein kinase and PTP activities results in abnormal protein phosphorylation, which has been linked to the etiology of several diseases, including cancer. In this study, we screened protein tyrosine phosphatases (PTPs) by in vitro phosphatase assays to identify PTPs that are inhibited by bis (4-trifluoromethyl-sulfonamidophenyl, TFMS)-1,4-diisopropylbenzene (PTP inhibitor IV). PTP inhibitor IV inhibited DUSP14 phosphatase activity. Kinetic studies with PTP inhibitor IV and DUSP14 revealed a competitive inhibition, suggesting that PTP inhibitor IV binds to the catalytic site of DUSP14. PTP inhibitor IV effectively and specifically inhibited DUSP14-mediated dephosphorylation of JNK, a member of the mitogen-activated protein kinase (MAPK) family.     

Rhaponticoidesaytachii sp. nov. (Asteraceae) from south Anatolia,Turkey

A new species of Rhaponticoides Vaill., Rhaponticoidesaytachii Y. Ba?c?, Do?u & Dinç sp. nov. collected by the authors from south Anatolia, is described and illustrated. The new species is restricted to deprived Quercus forest openness around Dumlugöze‐Sar?veliler (C4 Karaman). Diagnostic morphological characters from R. amplifolia (Boiss. & Heldr.) M.V. Agab. & Greuter are discussed. The ecology, biogeography and conservation status of the new species is also presented.     

Water-soluble N-carboxymethylchitosan derivatives: Preparation,characteristics and its application

In this work, only N-substituted chitosan derivatives (water-soluble N-carboxymethylchitosan derivatives: N-CMC) with different degrees of substitution were obtained by reaction of a fully deacetylated chitosan (derived from deacetylation of chitosan using decrystallized method) with monochloroacetic acid at pH 8 and temperature of 90 °C. The structure of N-carboxymethylchitosan and chitosan was characterized by IR, ¹H, ¹³C and ¹H–¹³C NMR-HSQC spectra. In the IR spectrum of the N-carboxymethylchitosan, the appearance of peak at 1742 cm^?1 was assigned for CO group of NHCH₂COOH of substituted chitosan. In the ¹H NMR spectra, the peaks at about 3.81÷4.06 ppm, assigned for CH₂ groups of NHCH₂ and N(CH₂)₂, were the major feature, while in the ¹H–¹³C NMR-HSQC spectra, signals of CH₂ confirmed the presence of these two different substituted CH₂ groups. The degree of substitution (DS) of N-monosubstitution (DS_N-mono) decreased from 0.47 to 0.03 meanwhile that of N,N-disubstitution (DS_N,N-di) increased from 0.52 to 0.96 since the mass ratio of chitosan/monochloroacetic acid changing from 1/1 to 1/4. The N-carboxymethylchitosan derivatives have been used for adsorption Cu(II) ion from aqueous solution. The results shown that the optimum conditions for adsorption Cu(II) ion in nitrate solution were pH 6.5, temperature of 30 °C, for 60–90 min and the substituted chitosan derivative having DS_N-mono of 0.16 and DS_N,N-di of 0.81 had maximum adsorption capacity of 192 mg Cu(II) per gram of N-CMC.     

A niche-based modeling approach to phytoplankton community assembly rules

Six niche-based models proposed by Tokeshi, based on different assumptions of resource allocation by species, were fitted on phytoplankton relative abundance distributions, and potential environmental and biotic factors supporting the applicability of the fitted models were discussed. Overall 16 assemblages corresponding to different sampling times, various environmental conditions, and resource regimes within a year were fitted to the models. Phytoplankton biovolume was used as a measure of abundance, and a randomization test was applied to compare the model fit to the field data. The majority of the phytoplankton assemblages (11 of 16) were successfully described by the Random Fraction model, which is based on the theoretical assumption that resource is apportioned by the species in a random way. Only a few assemblages (three of 16), characterized by extremes in resource availability or disturbance, were not fitted by any of the models. The Random Fraction model in particular was rejected due to a steep slope during the first ranks, while the rest of the distribution remained relatively even, providing further evidence of resilience in phytoplankton communities. Although larger cells seem to have the potential to develop higher biomass, it seems that other factors, including the surface-to-volume ratio, counterbalance this advantage, resulting in a random-like behaviour in resource acquisition by phytoplankton, irrespective of cell size or species identity.     

An immune responsive complement factor D/adipsin and kallikrein-like serine protease (PoDAK) from the olive flounder Paralichthys olivaceus

The cDNA encoding of a complement factor D/adipsin and kallikrein-like serine protease, designated PoDAK, was isolated from the olive flounder Paralichthys olivaceus. PoDAK cDNA encodes a polypeptide with 277 amino acids containing conserved catalytic triad residues of serine proteases. The amino acid sequence of PoDAK showed high similarity to the kallikrein-like protein of medaka, mammalian adipsin/complement factor D and tissue kallikrein homolog, KT-14 of trout, complement factor D of zebrafish, and shared 31.6–36.8% homology with complement factor D/adipsin known from other species, including mammals. Phylogenetic analysis revealed that PoDAK clustered with the kallikrein-like protein of medaka and mammalian adipsin/complement factor D and tissue kallikrein homolog KT-14 of trout. The expression of PoDAK mRNA was high in the gills and heart, moderate in muscle, liver, intestine, stomach, kidney, and spleen of healthy flounder, and increased in the kidney, liver, and spleen of flounder challenged by the viral hemorrhagic septicemia virus (VHSV) or Streptococcus iniae. In situ hybridization confirmed that PoDAK mRNA is localized in the kidney and heart of individuals infected with VHSV. Further investigations are needed to clarify the function of PoDAK in vivo and in vitro.     

Aeration alleviates ethanol inhibition and glycerol production during fed-batch ethanol fermentation

In this study, we investigated the effects of aeration on ethanol inhibition and glycerol production during fed-batch ethanol fermentation. When aeration was conducted at 0.13, 0.33, and 0.8 vvm, the ethanol productivity, specific ethanol production rate, and ethanol yield in the presence of greater than 100 g/L of ethanol were higher than when aeration was not conducted. In addition, estimation of the parameters (α and β) in a model equation of ethanol inhibition kinetics indicated that aeration alleviated ethanol inhibition against the specific growth rate and the specific ethanol production rate. Specifically, when aeration was conducted, the glycerol yield and specific glycerol production rate decreased approximately 50 and 70%, respectively. Finally, the results of this study indicated that aeration during fed-batch ethanol fermentation may improve the ethanol concentration in the final culture broth, as well as the ethanol productivity.     

Increased Store-Operated Ca Entry in Skeletal Muscle with Reduced Calsequestrin-1 Expression

Store-operated Ca²⁺ entry (SOCE) contributes to Ca²⁺ handling in normal skeletal muscle function, as well as the progression of muscular dystrophy and sarcopenia, yet the mechanisms underlying the change in SOCE in these states remain unclear. Previously we showed that calsequestrin-1 (CSQ1) participated in retrograde regulation of SOCE in cultured skeletal myotubes. In this study, we used small-hairpin RNA to determine whether knockdown of CSQ1 in adult mouse skeletal muscle can influence SOCE activity and muscle function. Small-hairpin RNA against CSQ1 was introduced into flexor digitorum brevis muscles using electroporation. Transfected fibers were isolated for SOCE measurements using the Mn²⁺ fluorescence-quenching method. At room temperature, the SOCE induced by submaximal depletion of the SR Ca²⁺ store was significantly enhanced in CSQ1-knockdown muscle fibers. When temperature of the bathing solution was increased to 39°C, CSQ1-knockdown muscle fibers displayed a significant increase in Ca²⁺ permeability across the surface membrane likely via the SOCE pathway, and a corresponding elevation in cytosolic Ca²⁺ as compared to control fibers. Preincubation with azumolene, an analog of dantrolene used for the treatment of malignant hyperthermia (MH), suppressed the elevated SOCE in CSQ1-knockdown fibers. Because the CSQ1-knockout mice develop similar MH phenotypes, this inhibitory effect of azumolene on SOCE suggests that elevated extracellular Ca²⁺ entry in skeletal muscle may be a key factor for the pathophysiological changes in intracellular Ca²⁺ signaling in MH.     

Quantification of Mineralized Bone Response to Prostate Cancer by Noninvasive In Vivo μCT and Non-Destructive Ex Vivo μCT and DXA in a Mouse Model

Background

To compare nondestructive in vivo and ex vivo micro-computed tomography (μCT) and ex vivo dual-energy-X-ray-absorptiometry (DXA) in characterizing mineralized cortical and trabecular bone response to prostate cancer involving the skeleton in a mouse model.

Methodology/Principal Findings

In vivo μCT was performed before and 10 weeks after implantation of human prostate cancer cells (MDA-PCa-2b) or vehicle into SCID mouse femora. After resection, femora were imaged by nondestructive ex vivo specimen μCT at three voxel sizes (31 µ, 16 µ, 8 µ) and DXA, and then sectioned for histomorphometric analysis of mineralized bone. Bone mineral density (BMD), trabecular parameters (number, TbN; separation, TbSp; thickness, TbTh) and mineralized bone volume/total bone volume (BV/TV) were compared and correlated among imaging methods and histomorphometry. Statistical tests were considered significant if P<0.05. Ten weeks post inoculation, diaphyseal BMD increased in the femur with tumor compared to the opposite femur by all modalities (p<0.005, n = 11). Diaphyseal BMD by in vivo μCT correlated with ex vivo 31 and 16 µm μCT and histomorphometry BV/TV (r = 0.91–0.94, P<0.001, n = 11). DXA BMD correlated less with bone histomorphometry (r = 0.73, P<0.001, n = 11) and DXA did not distinguish trabeculae from cortex. By in vivo and ex vivo μCT, trabecular BMD decreased (P<0.05, n = 11) as opposed to the cortex. Unlike BMD, trabecular morphologic parameters were threshold-dependent and when using “fixed-optimal-thresholds,” all except TbTh demonstrated trabecular loss with tumor and correlated with histomorphometry (r = 0.73–0.90, P<0.05, n = 11).

Conclusions/Significance

Prostate cancer involving the skeleton can elicit a host bone response that differentially affects the cortex compared to trabeculae and that can be quantified noninvasively in vivo and nondestructively ex vivo.     

Les larges vacuoles des têtes spermatiques sont-elles associées à des altérations du noyau ou de l’acrosome du spermatozoïde ?

Objective

The aim of this study was to detect acrosome and nucleus alterations in isolated spermatozoa with large vacuoles detected by MSOME (Motile Sperm Organelle Morphology Examination), named type 3 spermatozoa and defined by the presence of one or more vacuoles occupying more than 13% of the sperm head area.

Material and methods

Twenty infertile men were included in this study. Whole sperm and isolated spermatozoa were compared. Spermatozoa acrosome and nucleus were explored using 1) proacrosin immunostaining with a monoclonal antibody (4D4), 2) DNA fragmentation with TUNEL assay, 3) chromatin condensation with aniline blue staining, and 4) aneuploidy after fluorescence in situ hybridization (FISH) and analysis by electron transmission and confocal microscopy.

Results

Acrosome abnormalities were significantly increased in type 3 spermatozoa compared towhole sperm(77.8 ± 2.49% vs. 70.6 ± 2.62%). DNA fragmentation was similar in type 3 spermatozoa compared towhole sperm(14.5 ± 3.45%vs. 11.5 ± 1.25%). Chromatin condensation was significantly altered in isolated spermatozoa as well as aneuploidy frequencies (50.4 ± 3.10% vs. 26.5 ± 2.60% and 7.8 ± 1.98% vs. 1.3 ± 0.18%). Large vacuoles have an exclusive nuclear location, confirmed by electron and confocal microscopy.

Conclusion

Large vacuoles are probably due to sperm nucleus maturation dysfunction during spermiogenesis.