The von Hippel-Lindau tumor suppressor protein regulates gene expression and tumor growth through histone demethylase JARID1C

In clear-cell renal cell carcinoma (ccRCC), inactivation of the tumor suppressor von Hippel-Lindau (VHL) occurs in the majority of the tumors and is causal for the pathogenesis of ccRCC. Recently, a large-scale genomic sequencing study of ccRCC tumors revealed that enzymes that regulate histone H3 lysine 4 trimethylation (H3K4Me3), such as JARID1C/KDM5C/SMCX and MLL2, were mutated in ccRCC tumors, suggesting that H3K4Me3 might have an important role in regulating gene expression and tumorigenesis. In this study we report that in VHL-deficient ccRCC cells, the overall H3K4Me3 levels were significantly lower than that of VHL+/+ counterparts. Furthermore, this was hypoxia-inducible factor (HIF) dependent, as depletion of HIF subunits by small hairpin RNA in VHL-deficient ccRCC cells restored H3K4Me3 levels. In addition, we demonstrated that only loss of JARID1C, not JARID1A or JARID1B, abolished the difference of H3K4Me3 levels between VHL-/- and VHL+/+ cells, and JARID1C displayed HIF-dependent expression pattern. JARID1C in VHL-/- cells was responsible for the suppression of HIF-responsive genes insulin-like growth factor-binding protein 3 (IGFBP3), DNAJC12, COL6A1, growth and differentiation factor 15 (GDF15) and density-enhanced phosphatase 1. Consistent with these findings, the H3K4Me3 levels at the promoters of IGFBP3, DNAJC12, COL6A1 and GDF15 were lower in VHL-/- cells than in VHL+/+ cells, and the differences disappeared after JARID1C depletion. Although HIF2α is an oncogene in ccRCC, some of its targets might have tumor suppressive activity. Consistent with this, knockdown of JARID1C in 786-O VHL-/- ccRCC cells significantly enhanced tumor growth in a xenograft model, suggesting that JARID1C is tumor suppressive and its mutations are tumor promoting in ccRCC. Thus, VHL inactivation decreases H3K4Me3 levels through JARID1C, which alters gene expression and suppresses tumor growth.

New phylogenetically distinct cyanophages found in the coastal Yellow Sea by Qingdao

Genetic composition of natural cyanophage population in the coastal Yellow Sea area near Qingdao was investigated using the g20 gene as a genetic marker. Amplification of this gene by PCR yielded sequences, which were cloned and subjected to the restriction fragment length polymorphism (RFLP) analysis. Sixteen clones exhibiting different RFLP patterns were sequenced and analyzed. The sequence analysis indicated a diversity of cyanophages covering sixteen g20 genotypes. Their phylogenetic analysis revealed two distinct phylogenetic groups. One group (7clones) localized with the cyanophage P77 in the cluster III described before. Second group (9 clones) did not localize with any of the cyanophage described so far and was designated as a novel W cluster. The study revealed a genetic diversity of cyanophages in the coastal Yellow Sea and confirmed the genetic differences between cyanophage populations in Western and Eastern Pacific.

Developmental expression of ACRV1 in humans and mice

To identify the developmental expression of the ACRV1 gene in humans and mice, testes cDNA samples were collected at different post-natal days (days 4, 9, 18, 35, 54, and 6 months) from Balb/c mice and were hybridised to the mouse whole genome 430 2.0 Array (Affymetrix Inc.) chip. The characteristics of ACRV1 were analysed using various cellular and molecular biotechnologies. The results showed that the expression of mouse ACRV1 was not detected in mouse testes on days 4, 9, and 18 but was present on days 35, 54, and 6 months. Using RT-PCR analysis of mouse ACRV1, we determined that mouse ACRV1 was expressed specifically in the mouse testis, and its expression began at days 35. Western blot analysis demonstrated that human ACRV1 was primarily expressed in human testes, and immunofluorescent and immunohistochemistry staining showed that human ACRV1 protein was predominantly located in round and elongated spermatids in human testes, indicating that ACRV1 may play an important role in mammalian spermatogenesis and may be a target of a contraceptive vaccine.

Apoptosis: its functions and control in the ocular lens

The ocular lens is a non-vascular and non-innervated transparent organ that plays an important role in vision processing. This unique organ is derived from the embryonic ectoderm of the brain region through a complicated differentiation process in which apoptosis plays a key role. First, when the committed ectoderm becomes thickened and invaginated, the defined number of cells required to form the lens vesicle is partially determined by apoptosis. Second, separation of lens vesicle from the above corneal ectoderm is executed through apoptosis of the lens stalk cells. Finally, differentiation of the lens epithelial cells is controlled by the regulators, most of which are involved in control of apoptosis at multiple signaling steps. The lens is also characterized by continuous growth and differentiation in the adulthood. Through the different stages of growth and differentiation in the adult lens, various stress conditions can induce apoptosis of the lens epithelial cells, leading to eventual non-congenital cataractogenesis. The present review summarizes the current knowledge on the functions and regulators of apoptosis in the ocular lens.

Increased serum retinol-binding protein-4 levels in pregnant women with and without gestational diabetes mellitus

OBJECTIVE

Retinol-binding protein 4 (RBP4) is thought to be associated with insulin resistance in humans, while pregnancy is normally characterized by progressive insulin resistance. Gestational diabetes (GDM) occurs when pancreatic beta-cell function is unable to compensate for insulin resistance. This study aimed to determine whether or not serum RBP4 levels are elevated in pregnancy, and to explore the relationship between RBP4 levels and insulin resistance during pregnancy.

METHODS

Serum RBP4 was measured at median gestational week 26 in 121 pregnant women, including 63 with GDM (GDM group) and 58 normal, glucose-tolerant pregnant women (P-NGT group), as well as 65 non-pregnant normal, glucose-tolerant women (NP-NGT group). Multiple stepwise regression analysis was used to explore the independent factors of RBP4.

RESULTS

Serum RBP4 levels in the P-NGT and GDM groups were significantly higher than in the NP-NGT group (34.50±9.80 mg/L and 41.64±12.21 mg/L vs 30.64±9.46 mg/L, respectively; P<0.05) after adjusting for age, body mass index (BMI) and blood pressure. Furthermore, RBP4 levels were much higher in the GDM vs P-NGT group. Spearman's correlation analysis showed that serum RBP4 levels were positively correlated with triglycerides (TG), fasting plasma glucose, postprandial 2h plasma glucose and HOMA-IR in pregnancy. Of these, TG and HOMA-IR (r(2)=0.312) were independent factors of serum RBP4.

CONCLUSION

Serum RBP4 levels are significantly increased in pregnancy, independent of age and BMI, and are also considerably higher in pregnant women with GDM than in those with normal glucose tolerance. In addition, serum RBP4 levels appear to be a valuable marker of insulin resistance and dysfunctional lipid metabolism in pregnancy.

Lymphatic drainage of the skull base: comparative anatomic and advanced imaging studies in the rabbit and human with implications for spread of nasopharyngeal carcinoma

This preliminary study investigated the lymphatic drainage and distribution of lymphatic structures in the skull base. Characteristics of the rabbit skull base were analyzed and compared correspondingly with those of the human skull. The lymphatic circulation in the rabbit cranial base was detected by digital subtraction angiography (DSA), and lymph drainage in the human skull base was illustrated by interstitial magnetic resonance lymphography (MRL). Lymphatic structures and their distribution in MRL were identified by comparing with contrast-enhanced MRI and clinical data on basilar metastasis of nasopharyngeal carcinoma (NPC) in the human skull base. Anatomic similarity was found between the rabbit and human basilar regions. Well-visualized lymphatic pathways were found in the rabbit cranial base, and human lymphatic structures showed high signal intensity in enhanced T1-weighted MRL images. Lymphatic tissues in the human basilar region were found mainly distributed in the areas of the jugular foramen, foramen lacerum, and petrosal section of the internal carotid artery (ICA). Their distribution in the human basilar region was similar to the distribution in the rabbit basilar region and consistent with our clinical findings of the predilection sites of NPC metastasis in the skull base. Our studies show that bilateral symmetrical lymphatic structures were distributed along the ICA, internal jugular vein, and dura of cranial base in the central part of the middle and posterior skull base.

Phospho-Olivine as Advanced Cathode Material for Lithium Batteries

<p>Nano-sized and micron-sized LiFePO₄ electrode materials were prepared by a sol gel and coprecipitation reactions. An improvement of the cycling and rate performances in lithium cells was observed for the carbon coated LiFePO₄ materials. The coating process uses a solid/gas-phase reaction which consists of decomposing propylene gas, as carbon source, inside a reactor containing olivine LiFePO₄ materials. Optimized LiFePO₄ electrode cells, cycled at RT between 3.0 and 4.3 V at a C/10 rate, do not show any sign of capacity fade during the first 50 cycles. Combination of the high volumetric energy density and low cost preparation method makes the micron-sized LiFePO₄ olivine an attractive safe cathode for lithium-ion batteries.</p>

Occurrence of ammonia-oxidizing Archaea in activated sludges of a laboratory scale reactor and two wastewater treatment plants

AIMS

Characterization of the ammonia-oxidizing archaea (AOA) community in activated sludge from a nitrogen removal bioreactor and wastewater treatment plants (WWTPs).

METHODS AND RESULTS

Three primer sets specific for ammonia mono-oxygenase alpha-subunit (amoA) were used to construct clone libraries for activated sludge sample from a nitrogen removal bioreactor. One primer set resulted in strong nonspecific PCR products. The other two clone libraries retrieved both shared and unique AOA amoA sequences. One primer set was chosen to study the AOA communities of activated sludge samples from Shatin and Stanley WWTPs. In total, 18 AOA amoA sequences were recovered and compared to the previous reported sequences. A phylogenetic analysis indicated that sequences found in this study fell into three clusters.

CONCLUSIONS

Different primers resulted in varied AOA communities from the same sample. The AOA found from Hong Kong WWTPs were closely similar to those from sediment and soil, but distinct from those from activated sludge in other places. A comparison of clone libraries between Shatin WWTP and bioreactor indicated the AOA community significantly shifted only after 30-day enrichment.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study confirmed the occurrence of AOA in a laboratory scale nitrogen removal bioreactor and Hong Kong WWTPs treating saline or freshwater wastewater. AOA communities found in this study were significantly different from those found in other places. To retrieve diverse AOA communities from environmental samples, a combination of different primers for the amoA gene is needed.

High-coercivity FePt nanoparticle assemblies embedded in silica thin films

The ability to process assemblies using thin film techniques in a scalable fashion would be a key to transmuting the assemblies into manufacturable devices. Here, we embed FePt nanoparticle assemblies into a silica thin film by sol-gel processing. Annealing the thin film composite at 650 degrees C transforms the chemically disordered fcc FePt phase into the fct phase, yielding magnetic coercivity values H(c)>630 mT. The positional order of the particles is retained due to the protection offered by the silica host. Such films with assemblies of high-coercivity magnetic particles are attractive for realizing new types of ultra-high-density data storage devices and magneto-composites.

Biotransformation of Panax notoginseng saponins into ginsenoside compound K production by Paecilomyces bainier sp. 229

AIMS

Development and optimization of an efficient and inexpensive biotransformation process for ginsenoside compound K production by Paecilomyces bainier sp. 229.

METHODS AND RESULTS

We have determined the optimum culture conditions required for the efficient production of ginsenoside compound K by P. bainier sp. 229 via biotransformation of ginseng saponin substrate. The optimal medium constituents were determined to be: 30 g sucrose, 30 g soybean steep powder, 1 g wheat bran powder, 1 g (NH(4))(2)SO(4), 2 g MgSO(4) x 7H(2)O and 1 g CaCl(2) in 1 l of distilled water. An inoculum size of 5-7.5% with an optimal pH range of 4.5-5.5 was essential for high yield.

CONCLUSIONS

The Mol conversion quotient of ginseng saponins increased from 21.2% to 72.7% by optimization of the cultural conditions. Scale-up in a 10 l fermentor, under conditions of controlled pH and continuous air supply in the optimal medium, resulted in an 82.6% yield of ginsenoside compound K.

SIGNIFICANT AND IMPACT OF THE STUDY

This is the first report on the optimization of culture conditions for the production of ginsenoside compound K by fungal biotransformation. The degree of conversion is significantly higher than previous reports. Our method describes an inexpensive, rapid and efficient biotransformation system for the production of ginsenoside compound K.

Laparoscopically assisted sigmoid colon vaginoplasty in women with Mayer-Rokitansky-Kuster-Hauser syndrome: feasibility and short-term results

OBJECTIVES

To evaluate the technical feasibility and anatomical and functional outcomes of laparoscopically assisted sigmoid colon vaginoplasty (LASV) in women with Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome.

DESIGN

A retrospective review of prospectively collected data.

SETTING

Shanghai First People's Hospital, Shanghai Jiao Tong University.

POPULATION

Twenty-six women with MRKH syndrome.

METHODS

A record was made of mean operating time, length of hospital stay, perioperative complications and the anatomical and functional outcomes of surgery.

MAIN OUTCOME MEASURES

The perioperative results, complications and anatomical and functional outcomes of LASV (with median 20 months follow up, range 5-48 months).

RESULTS

The mean operating time and hospital stay were 238 minutes and 9.8 days, respectively. The mean fall in haemoglobin was 2.0 g/dl. The only significant perioperative complications were one case with blood transfusion and three cases with infection (one with urinary tract and two with adjunctive incision). A functioning vagina 10 to 15 cm in length and 4 cm in width was created in all women. Introital stenosis occurred in only two women (2 months later). Twenty-two women subsequently had intercourse and 20 women (91%) were satisfied with the surgery and subsequent sexual activity.

CONCLUSIONS

LASV is an effective approach for women with MRKH syndrome. Both the anatomical and functional outcomes are satisfactory.

The role of EGFR trafficking in neuroblastoma

20003

Background: Signaling through growth factor receptors is important in neuroblastoma pathogenesis. Chromosome 1p36 is commonly deleted in neuroblastoma tumors and is associated with a poor prognosis. UBE4B, a gene in 1p36, has been reported mutated in high- risk neuroblastoma. We have found a direct interaction between UBE4B and hrs, a protein required for epidermal growth factor receptor (EGFR) trafficking, suggesting a link between EGFR trafficking and neuroblastoma pathogenesis. We have analyzed the role of UBE4B in the EGFR pathway in neuroblastoma cell lines. Methods: The expression of UBE4B, hrs and EGFR were analyzed by quantitative Western blot in a panel of 7 human neuroblastoma cell lines (SHEP, SKNAS, SKNSH, KCNR, SY5Y, LA155N, NGP). EGFR degradation rates were determined by examining the kinetics of cellular EGFR depletion following a pulse of ligand. Results: UBE4B levels were lowest in SKNAS and highest in NGP cells. Hrs levels were lowest in SKNSH cells and higher in other cell lines. EGFR levels were lowest in NGP and KCNR and highest in SKNAS cells. UBE4B levels were correlated with known 1p deletions. EGFR degradation rates were slowest in SKNAS cells and therefore correlated with cellular UBE4B levels. The low degradation rates were correlated with high cellular levels of EGFR. Conclusions: Expression levels of UBE4B are correlated in neuroblastoma cell lines with chromosome 1p deletions. Cell lines with lower levels of UBE4B degrade EGFR at a markedly slower rate, correlated with higher cellular EGFR levels. We hypothesize that UBE4B affects cell growth by interacting with hrs, directing EGFR for degradation. In its absence the ability of a cell to sort growth factor receptors for degradation is inhibited, resulting in growth factor receptor overabundance and uncontrolled cell growth. These results support the testing of EGFR inhibitors in a future phase I trial for children with neuroblastoma.

No significant financial relationships to disclose.

Micromolar fluoride alters ameloblast lineage cells in vitro

Fluorosed enamel is caused by exposure to fluoride during tooth formation. The objective of this study was to determine whether epithelial ameloblast-lineage cells, derived from the human enamel organ, are directly affected by micromolar concentrations of fluoride. Cells were cultured in the presence of fluoride, and proliferation was measured by BrdU incorporation. The effect of 0, 10, or 20 microM fluoride on apoptosis was determined by the flow cytometry apoptotic index. The effects of fluoride on gene expression were investigated by SuperArray microarray analysis and real-time PCR. Fluoride had a biphasic effect on cell proliferation, with enhanced proliferation at 16 microM, and reduced proliferation at greater than 1 mM F. Flow cytometry showed that both 10 microM and 20 microM NaF significantly increased the apoptotic index of ameloblast-lineage cells. There was no general effect of fluoride on gene expression. These results indicate multiple effects of micromolar fluoride on ameloblast-lineage cells.

Protein serine/threonine phosphatase-1 dephosphorylates p53 at Ser-15 and Ser-37 to modulate its transcriptional and apoptotic activities

We have previously demonstrated that the serine/threonine protein phosphatase-1 (PP-1) plays an important role in promoting cell survival. However, the molecular mechanisms by which PP-1 promotes survival remain largely unknown. In the present study, we provide evidence to show that PP-1 can directly dephosphorylate a master regulator of apoptosis, p53, to negatively modulate its transcriptional and apoptotic activities, and thus to promote cell survival. As a transcriptional factor, the function of p53 can be greatly regulated by phosphorylation and dephosphorylation. While the kinases responsible for phosphorylation of the 17 serine/threonine sites have been identified, the dephosphorylation of these sites remains largely unknown. In the present study, we demonstrate that PP-1 can dephosphorylate p53 at Ser-15 and Ser-37 through co-immunoprecipitation, in vitro and in vivo dephosphorylation assays, overexpression and silence of the gene encoding the catalytic subunit for PP-1. We further show that mutations mimicking constitutive dephosphorylation or phosphorylation of p53 at these sites attenuate or enhance its transcriptional activity, respectively. As a result of the changed p53 activity, expression of the downstream apoptosis-related genes such as bcl-2 and bax is accordingly altered and the apoptotic events are either largely abrogated or enhanced. Thus, our results demonstrate that PP-1 directly dephosphorylates p53, and dephosphorylation of p53 has as important impact on its functions as phosphorylation does. In addition, our results reveal that one of the molecular mechanisms by which PP-1 promotes cell survival is to dephosphorylate p53, and thus negatively regulate p53-dependent death pathway.

Abdominal radical trachelectomy: two new surgical techniques for the conservation of uterine arteries

The objective of this study was to develop two new techniques for the conservation of uterine arteries in abdominal radical trachelectomy. Abdominal trachelectomy with conservation of uterine arteries was performed in two patients with cervical carcinoma. In the first case, the internal iliac artery was divided at 2.0 cm from the bifurcation of the common iliac artery. The internal iliac artery and uterine artery were skeletonized along their lengths to the lateral cervix. The dissected internal iliac artery was then reanastomosed following the radical trachelectomy. In the second case, the technique was similar to that of the first except that the internal iliac artery was not divided. Intraoperative observation and postoperative color Doppler ultrasound were used to confirm the patency of the uterine arteries. The operative time of the two patients was 390 min. and 350 min, respectively. Doppler flow studies demonstrated that the uterine arteries were patent in both cases. Resistance index of the left and the right uterine artery was 0.58 and 0.61, respectively, in the first case, and 0.60 and 0.63, respectively, in the second case. Reanastomosis of the internal iliac arteries or skeletonization of the internal iliac arteries are both feasible methods to conserve the uterine arteries during abdominal radical trachelectomy.

Maxi-K channels contribute to urinary potassium excretion in the ROMK-deficient mouse model of Type II Bartter's syndrome and in adaptation to a high-K diet

Type II Bartter's syndrome is a hereditary hypokalemic renal salt-wasting disorder caused by mutations in the ROMK channel (Kir1.1; Kcnj1), mediating potassium recycling in the thick ascending limb of Henle's loop (TAL) and potassium secretion in the distal tubule and cortical collecting duct (CCT). Newborns with Type II Bartter are transiently hyperkalemic, consistent with loss of ROMK channel function in potassium secretion in distal convoluted tubule and CCT. Yet, these infants rapidly develop persistent hypokalemia owing to increased renal potassium excretion mediated by unknown mechanisms. Here, we used free-flow micropuncture and stationary microperfusion of the late distal tubule to explore the mechanism of renal potassium wasting in the Romk-deficient, Type II Bartter's mouse. We show that potassium absorption in the loop of Henle is reduced in Romk-deficient mice and can account for a significant fraction of renal potassium loss. In addition, we show that iberiotoxin (IBTX)-sensitive, flow-stimulated maxi-K channels account for sustained potassium secretion in the late distal tubule, despite loss of ROMK function. IBTX-sensitive potassium secretion is also increased in high-potassium-adapted wild-type mice. Thus, renal potassium wasting in Type II Bartter is due to both reduced reabsorption in the TAL and K secretion by max-K channels in the late distal tubule.

Microcalorimetric studies on the polyhydroxyalkanoates production of recombinant Escherichia coli

The thermogenic curves of metabolism of two strains of Escherichia coli pUC19cab/XL-IBlue and XL-IBlue have been determined by using a LKB-2277 bioActivity Monitor and ampoule method at 37 degrees C. pUC19cab/XL-IBlue was a recombinant E. coli strain bearing a foreign plasmid pUC19cab which brought the polyhydroxyalkanoates (PHAs) production. XL-IBlue was a host bacterium without any foreign DNA. Our studies reveal that the PHA production of recombinant E. coli has an apparent influence on their thermogenic curves of metabolism and therefore the initial time of PHAs production can be determined from these thermogenic curves.

Patterns of expression of brain-derived neurotrophic factor and tyrosine kinase B mRNAs and distribution and ultrastructural localization of their proteins in the visual pathway of the adult rat

We have examined the cellular and subcellular distribution and the patterns of expression of brain-derived neurotrophic factor (BDNF), and of its high affinity receptor, tyrosine kinase B (TrkB), in retinorecipient regions of the brain, including the superior colliculus, the lateral geniculate nucleus and the olivary pretectal nucleus. In the retinorecipient layers of the superior colliculus, BDNF protein and mRNA were present in the cell bodies of a subpopulation of neurons, and BDNF protein was present in the neuropil as punctate or fiber-like structures. In the lateral geniculate nucleus, however, BDNF mRNA was not detected, and BDNF protein was restricted to punctate and fiber-like structures in the neuropil, especially in the most superficial part of the dorsal lateral geniculate nucleus, just below the optic tract. At the ultrastructural level, BDNF protein was localized predominantly to axon terminals containing round synaptic vesicles and pale mitochondria with irregular cristae, which made asymmetric (Gray type I) synaptic specializations (R-boutons). Enucleation of one eye was followed by loss of BDNF immunoreactivity and disappearance of BDNF-positive R-boutons in the contralateral visual centers, confirming the retinal origin of at least most of these terminals. TrkB was present in postsynaptic densities apposed to immunoreactive R-boutons in the superior colliculus and lateral geniculate nucleus, and was also associated with axonal and dendritic microtubules. These findings suggest that BDNF is synthesized by a subpopulation of retinal ganglion cells and axonally transported to visual centers where this neurotrophin is assumed to play important roles in visual system maintenance and/or in modulating the excitatory retinal input to neurons in these centers.