Playing Tag with HIF: The VHL Story

Inactivation of the von Hippel-Lindau (VHL) tumour suppressor gene product pVHL is the cause of inherited VHL disease and is associated with sporadic kidney cancer. pVHL is found in a multiprotein complex with elongins B/C, Cul2, and Rbx1 forming an E3 ubiquitin ligase complex called VEC. This modular enzyme targets the α subunits of hypoxia-inducible factor (HIF) for ubiquitin-mediated destruction. Consequently, tumour cells lacking functional pVHL overproduce the products of HIF-target genes such as vascular endothelial growth factor (VEGF), which promotes angiogenesis. This likely accounts for the hypervascular nature of VHL-associated neoplasms. Although pVHL has been linked to the cell-cycle, differentiation, and the regulation of extracellular matrix assembly, microenvironment pH, and tissue invasiveness, this review will focus on the recent insights into the molecular mechanisms governing the E3 ubiquitin ligase function of VEC

Fuel consumption and emissions performance under real driving: Comparison between hybrid and conventional vehicles

© 2018 Elsevier B.V. Hybrid electric vehicles (HEVs) are perceived to be more energy efficient and less polluting than conventional internal combustion engine (ICE) vehicles. However, increasing evidence has shown that real-driving emissions (RDE) could be much higher than laboratory type approval limits and the advantages of HEVs over their conventional ICE counterparts under real-driving conditions have not been studied extensively. Therefore, this study was conducted to evaluate the real-driving fuel consumption and pollutant emissions performance of HEVs against their conventional ICE counterparts. Two pairs of hybrid and conventional gasoline vehicles of the same model were tested simultaneously in a novel convoy mode using two portable emission measurement systems (PEMSs), thus eliminating the effect of vehicle configurations, driving behaviour, road conditions and ambient environment on the performance comparison. The results showed that although real-driving fuel consumption for both hybrid and conventional vehicles were 44%–100% and 30%–82% higher than their laboratory results respectively, HEVs saved 23%–49% fuel relative to their conventional ICE counterparts. Pollutant emissions of all the tested vehicles were lower than the regulation limits. However, HEVs showed no reduction in HC emissions and consistently higher CO emissions compared to the conventional ICE vehicles. This could be caused by the frequent stops and restarts of the HEV engines, as well as the lowered exhaust gas temperature and reduced effectiveness of the oxidation catalyst. The findings therefore show that while achieving the fuel reduction target, hybridisation did not bring the expected benefits to urban air quality

Feeding calf starter after birth can promote calf performance for increasing quality of cow replacement stock

Newborn calve has an undeveloped rumen and tend to easily diarrhea caused by E. coli from environment and cause death. Feeding calf starter (CS) content probiotic after birth can promote rumen development and suppress E. coli. This experiment aimed to evaluate the effect of different feeding calf starter to FH calf performance. Different test (t-test) was used in this experiment. The treatments were the use of different calf starter: 1. Calf starter from farmer (CS-F), 2. Calf starter content fermented waste cabbage (CS-L). The materials were CS content waste cabbage fermented, CS from farmer and 30 Frisian Holstein calves with aged 7-14 days and 41.14 ± 3.28 kg initial body weight. Feeding calf starter twice per day after giving milk, forage and water given ad libitum. The parameters measured were feed intake, feces consistency and daily gain. The data were analyzed with t- test. The result indicated that there were no different (P>0.05) on feed intake and average daily gain, but CS content fermented waste cabbage produced feces consistency better than (P<0.05) CS from farmer. Feeding calf starter with added fermented waste cabbage produce good calve performance. Key words: calf starter, fermented cabbage waste, feed intake, feces consistency and body weight gai

Inhibition of SHP2-mediated dephosphorylation of Ras suppresses oncogenesis

Ras is phosphorylated on a conserved tyrosine at position 32 within the switch I region via Src kinase. This phosphorylation inhibits the binding of effector Raf while promoting the engagement of GTPase-activating protein (GAP) and GTP hydrolysis. Here we identify SHP2 as the ubiquitously expressed tyrosine phosphatase that preferentially binds to and dephosphorylates Ras to increase its association with Raf and activate downstream proliferative Ras/ERK/MAPK signalling. In comparison to normal astrocytes, SHP2 activity is elevated in astrocytes isolated from glioblastoma multiforme (GBM)-prone H-Ras(12V) knock-in mice as well as in glioma cell lines and patient-derived GBM specimens exhibiting hyperactive Ras. Pharmacologic inhibition of SHP2 activity attenuates cell proliferation, soft-agar colony formation and orthotopic GBM growth in NOD/SCID mice and decelerates the progression of low-grade astrocytoma to GBM in a spontaneous transgenic glioma mouse model. These results identify SHP2 as a direct activator of Ras and a potential therapeutic target for cancers driven by a previously 'undruggable' oncogenic or hyperactive Ras

Quantitative Cell-based Protein Degradation Assays to Identify and Classify Drugs That Target the Ubiquitin-Proteasome System

We have generated a set of dual-reporter human cell lines and devised a chase protocol to quantify proteasomal degradation of a ubiquitin fusion degradation (UFD) substrate, a ubiquitin ligase CRL2^(VHL) substrate, and a ubiquitin-independent substrate. Well characterized inhibitors that target different aspects of the ubiquitin-proteasome system can be distinguished by their distinctive patterns of substrate stabilization, enabling assignment of test compounds as inhibitors of the proteasome, ubiquitin chain formation or perception, CRL activity, or the UFD-p97 pathway. We confirmed that degradation of the UFD but not the CRL2^(VHL) or ubiquitin-independent substrates depends on p97 activity. We optimized our suite of assays to establish conditions suitable for high-throughput screening and then validated their performance by screening against 160 cell-permeable protein kinase inhibitors. This screen identified Syk inhibitor III as an irreversible p97/vasolin containing protein inhibitor (IC_(50) = 1.7 μm) that acts through Cys-522 within the D2 ATPase domain. Our work establishes a high-throughput screening-compatible pipeline for identification and classification of small molecules, cDNAs, or siRNAs that target components of the ubiquitin-proteasome system

Butterflies (Lepidoptera: Papilionoidea and Hesperioidea) of the Parque Ecologic Joao Vasconcelos Sobrinho, Caruaru, Pernambuco, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Comprising a natural reserve with 359 ha of "montane forest" inserted on the Brazilian semi-arid, the Parque Ecologic Joao Vasconcelos Sobrinho (PEJVS), locally known as "Brejo dos Cavalos" is currently under high anthropogenic pressure. A list of 197 species of butterflies belonging to six families is presented, being 59 species of Hesperiidae, 4 of Papilionidae, 18 of Pieridae, 17 of Lycaenidae, 12 of Riodinidae and 87 of Nymphalidae. The butterfly community was composed mainly by widespread species commonly found in open habitats. There were also many species typical of forested areas such as Scada karschina delicata Talbot, 1932 (Danainae: Ithomiini), which is an endangered butterfly.114229238Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FACEPE [APQ - 0011-2.04/07]OHHMMMCFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)National Science Foundation (DEB) [0527441]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)CNPq [DCR - 0045-2.04/06]FACEPE [APQ - 0011-2.04/07]CNPq [300282/2008-7]FAPESP [00/01484-1, 04/05269-9]National Science Foundation (DEB) [0527441]CNPq [563332/2010-7

Genetic Analysis of Pathways Regulated by the von Hippel-Lindau Tumor Suppressor in Caenorhabditis elegans

The von Hippel-Lindau (VHL) tumor suppressor functions as a ubiquitin ligase that mediates proteolytic inactivation of hydroxylated α subunits of hypoxia-inducible factor (HIF). Although studies of VHL-defective renal carcinoma cells suggest the existence of other VHL tumor suppressor pathways, dysregulation of the HIF transcriptional cascade has extensive effects that make it difficult to distinguish whether, and to what extent, observed abnormalities in these cells represent effects on pathways that are distinct from HIF. Here, we report on a genetic analysis of HIF-dependent and -independent effects of VHL inactivation by studying gene expression patterns in Caenorhabditis elegans. We show tight conservation of the HIF-1/VHL-1/EGL-9 hydroxylase pathway. However, persisting differential gene expression in hif-1 versus hif-1; vhl-1 double mutant worms clearly distinguished HIF-1–independent effects of VHL-1 inactivation. Genomic clustering, predicted functional similarities, and a common pattern of dysregulation in both vhl-1 worms and a set of mutants (dpy-18, let-268, gon-1, mig-17, and unc-6), with different defects in extracellular matrix formation, suggest that dysregulation of these genes reflects a discrete HIF-1–independent function of VHL-1 that is connected with extracellular matrix function