USP9X deubiquitylating enzyme maintains RAPTOR protein levels, mTORC1 signalling and proliferation in neural progenitors

USP9X, is highly expressed in neural progenitors and, essential for neural development in mice. In humans, mutations in USP9X are associated with neurodevelopmental disorders. To understand USP9X's role in neural progenitors, we studied the effects of altering its expression in both the human neural progenitor cell line, ReNcell VM, as well as neural stem and progenitor cells derived from Nestin-cre conditionally deleted Usp9x mice. Decreasing USP9X resulted in ReNcell VM cells arresting in G0 cell cycle phase, with a concomitant decrease in mTORC1 signalling, a major regulator of G0/G1 cell cycle progression. Decreased mTORC1 signalling was also observed in Usp9x-null neurospheres and embryonic mouse brains. Further analyses revealed, (i) the canonical mTORC1 protein, RAPTOR, physically associates with Usp9x in embryonic brains, (ii) RAPTOR protein level is directly proportional to USP9X, in both loss- and gain-of-function experiments in cultured cells and, (iii) USP9X deubiquitlyating activity opposes the proteasomal degradation of RAPTOR. EdU incorporation assays confirmed Usp9x maintains the proliferation of neural progenitors similar to Raptor-null and rapamycin-treated neurospheres. Interestingly, loss of Usp9x increased the number of sphere-forming cells consistent with enhanced neural stem cell self-renewal. To our knowledge, USP9X is the first deubiquitylating enzyme shown to stabilize RAPTOR.Caitlin R. Bridges, Men-Chee Tan, Susitha Premarathne, Devathri Nanayakkara, Bernadette Bellette, Dusan Zencak, Deepti Domingo, Jozef Gecz, Mariyam Murtaza, Lachlan A. Jolly and Stephen A. Woo

Prevalence and antimicrobial susceptibility of Vibrio parahaemolyticus isolated from short mackerels (Rastrelliger brachysoma) in Malaysia

Numerous prevalence studies and outbreaks of Vibrio parahaemolyticus infection have been extensively reported in shellfish and crustaceans. Information on the quantitative detection of V. parahaemolyticus in finfish species is limited. In this study, short mackerels (Rastrelliger brachysoma) obtained from different retail marketplaces were monitored with the presence of total and pathogenic strains of V. parahaemolyticus. Out of 130 short mackerel samples, 116 (89.2%) were detected with the presence of total V. parahaemolyticus and microbial loads of total V. parahaemolyticus ranging from 105 MPN/g. Prevalence of total V. parahaemolyticus was found highest in wet markets (95.2%) followed by minimarkets (89.1%) and hypermarkets (83.3%). Pathogenic V. parahaemolyticus strains (tdh+ and/or trh+) were detected in 16.2% (21 of 130) of short mackerel samples. The density of tdh+ V. parahaemolyticus strains were examined ranging from 3.6 to >105 MPN/g and microbial loads of V. parahaemolyticus strains positive for both tdh and trh were found ranging from 300 to 740 MPN/g. On the other hand, antibiotic susceptibility profiles of V. parahaemolyticus strains isolated from short mackerels were determined through disc diffusion method in this study. Assessment of antimicrobial susceptibility profile of V. parahaemolyticus revealed majority of the isolates were highly susceptible to ampicillin sulbactam, meropenem, ceftazidime, and imipenem, but resistant to penicillin G and ampicillin. Two isolates (2.99%) exhibited the highest multiple antibiotic resistance (MAR) index value of 0.41 which shown resistance to 7 antibiotics. Results of the present study demonstrated that the occurrence of pathogenic V. parahaemolyticus strains in short mackerels and multidrug resistance of V. parahaemolyticus isolates could be a potential public health concerns to the consumer. Furthermore, prevalence data attained from the current study can be further used to develop a microbial risk assessment model to estimate health risks associated with the consumption of short mackerels contaminated with pathogenic V. parahaemolyticus

SOUNDNESS OF MONEY: CREDIBILITY OF COLOMBO CONSUMER PRICE INDEX [CCPI(N)] AS A MEASURE OF INFLATION IN SRI LANKA

In order to remedy the lacunae in the price index of Sri Lanka that the latter half of the 20th century, the concerned authorities have, since 2002, been using a new methods procurement of data and analyses. However, due to rigid assumptions and “rules of thumb” upon which these index calculation models rest, the figures that denote the price index do not seem to be considered as sound and proper. Then in consequence, the rate of inflation which rests on the price index figures do not denote the true and fair picture of the status of the economy. The undertaken study is based on the scrutiny of the data for the period of 1952 to 2010 obtained from the Central Bank of Sri Lanka. Semi-structured interviews of the concern individuals and authorities were conducted for the purpose of gathering qualitative data. E-views and MSExcel software were utilized for the purpose of analyses. With these statistical test models, this paper seeks to estimate some of those errors made in the calculations of the consumer price index. The results of the study show that there are glaring deficiencies with the present CCPI(N) system. These comprise, inter alia, the non-inclusion of the depreciation/ appreciation of the currency, rise/decline in import prices, and the shift of the cost of living, all of which have direct coupling with inflation. Then they include also the lack of proper representation of the weights associated with consumption patterns of the poor, lack of regional representation, and non-inclusion of some social undesirables including the consumption of alcohol. These lacunae render significant impact on true measure of per capita income growth, redistributive justice of incomes and the figures denoting un- or quasi-employment. Key Words: Laspeyres Price Indexes, Inflation, CCPI(N), Consumer Price Index, Monitory PolicyFor full paper: [email protected]

The ubiquitin system: a regulatory hub for intellectual disability and autism spectrum disorder

Intellectual disability (ID) and autism spectrum disorder (ASD) are two of the most common neurodevelopmental disorders. Both disorders are extremely heterogenous, and only ~ 40% of reported cases have so far been attributed to genetic mutations. Of the many cellular processes that are affected, the ubiquitin system (UbS) is of particular relevance in that it can rapidly regulate multiple signaling cascades simultaneously. The UbS is a post-translational modification process that revolves around the covalent attachment of a ubiquitin moiety to a substrate, thereby influencing different elements of protein biology, including trafficking, signal transduction, and degradation. Importantly, the UbS has been implicated in regulating multiple pathophysiological pathways related to ASD and ID. This review will discuss how the UbS acts as major signaling hub in the pathogenesis of ASD and ID, raising the prospect of treating broader patient cohorts by targeting the UbS as a common point of convergence of various mutations

Prevalence and Antibiotic Resistance against Tetracycline in Campylobacter jejuni and C. coli in Cattle and Beef Meat from Selangor, Malaysia

Campylobacter is a major foodborne pathogen frequently associated with human bacterial gastroenteritis in the world. This study was conducted to determine the prevalence and antibiotic resistance of Campylobacter spp. in the beef food system in Malaysia. A total of 340 samples consisting of cattle feces (n = 100), beef (n = 120) from wet markets and beef (n = 120) from hypermarkets were analyzed for Campylobacter spp. The overall prevalence of Campylobacter was 17.4%, consisting of 33% in cattle fecal samples, 14.2% in raw beef from wet market and 7.5% in raw beef from the hypermarket. The multiplex-polymerase chain reaction (PCR) identified 55% of the strains as C. jejuni, 26% as C. coli, and 19% as other Campylobacter spp. A high percentage of Campylobacter spp. were resistant to tetracycline (76.9%) and ampicillin (69.2%), whilst low resistance was exhibited to chloramphenicol (7.6%). The MAR Index of Campylobacter isolates from this study ranged from 0.09 to 0.73. The present study indicates the potential public health risk associated with the beef food system, hence stringent surveillance, regulatory measures, and appropriate interventions are required to minimize Campylobacter contamination and prudent antibiotic usage that can ensure consumer safety

Prevalence and Antimicrobial Susceptibility of Vibrio parahaemolyticus Isolated from Short Mackerels (Rastrelliger brachysoma) in Malaysia

Numerous prevalence studies and outbreaks of Vibrio parahaemolyticus infection have been extensively reported in shellfish and crustaceans. Information on the quantitative detection of V. parahaemolyticus in finfish species is limited. In this study, short mackerels (Rastrelliger brachysoma) obtained from different retail marketplaces were monitored with the presence of total and pathogenic strains of V. parahaemolyticus. Out of 130 short mackerel samples, 116 (89.2%) were detected with the presence of total V. parahaemolyticus and microbial loads of total V. parahaemolyticus ranging from 10[5] MPN/g. Prevalence of total V. parahaemolyticus was found highest in wet markets (95.2%) followed by minimarkets (89.1%) and hypermarkets (83.3%). Pathogenic V. parahaemolyticus strains (tdh+ and/or trh+) were detected in 16.2% (21 of 130) of short mackerel samples. The density of tdh+ V. parahaemolyticus strains were examined ranging from 3.6 to >105 MPN/g and microbial loads of V. parahaemolyticus strains positive for both tdh and trh were found ranging from 300 to 740 MPN/g. On the other hand, antibiotic susceptibility profiles of V. parahaemolyticusstrains isolated from short mackerels were determined through disc diffusion method in this study. Assessment of antimicrobial susceptibility profile of V. parahaemolyticusrevealed majority of the isolates were highly susceptible to ampicillin sulbactam, meropenem, ceftazidime, and imipenem, but resistant to penicillin G and ampicillin. Two isolates (2.99%) exhibited the highest multiple antibiotic resistance (MAR) index value of 0.41 which shown resistance to 7 antibiotics. Results of the present study demonstrated that the occurrence of pathogenic V. parahaemolyticus strains in short mackerels and multidrug resistance of V. parahaemolyticus isolates could be a potential public health concerns to the consumer. Furthermore, prevalence data attained from the current study can be further used to develop a microbial risk assessment model to estimate health risks associated with the consumption of short mackerels contaminated with pathogenic V. parahaemolyticus

Loss of <i>Usp9x</i> reduces neuronal outgrowth.

<p>Embryonic hippocampal neurons were isolated, transfected with a plasmid encoding Enhanced Green Fluorescent Protein, and grown in-vitro for 3, 5 or 7 days. (a) Example immunofluorescent images of wildtype (Nes-<i>Usp9x^+/Y</i>) and null (Nes-<i>Usp9x^−/Y</i>) neurons resolved using GFP expression (Green) and co-stained with the axonal and dendritic specific antibodies, TAU1 (cyan) and MAP2 (red) respectively. (b–c) Morphometric analysis was employed to record mean primary axonal length (b) and number of neurite termini (c). *p<0.05 by student 2-tailed t-test.</p

<i>Usp9x</i> is required for hippocampal development.

<p>The hippocampi of adult Emx1-<i>Usp9x^−/Y</i> mice (B) were reduced in area compared with <i>Usp9x^+/Y</i> littermates (A). Nissl stain of 7–8week old mice. (C) Quantification of hippocampal area of <i>Usp9x^+/Y</i> adult males (Control, n = 4) compared with <i>Usp9x^−/Y</i> (cKO, n = 4) (** p<0.01). (D–F) Higher magnification identifying disruption and reduction of the CA3 region in <i>Usp9x ^−/Y</i> males. (D - <i>Usp9x^+/Y</i>; E,F independent <i>Usp9x^−/Y</i> males) Scale bar = 100 µm (A,B), 150 µm (D–F).</p

Loss of <i>Usp9x</i> disrupts the architecture of the embryonic neocortex.

<p>The Nestin-cre mediated deletion of Usp9x (B,D) results in loss of demarcation between the cells of the ventricular and sub-ventricular zones (VZ/SVZ), the more disperse cellular density of the intermediate zone (IZ) and the neurons of the cortical plate (CP) seen in control littermates (A,C). C and D are higher magnification images of A and B, respectively. Nestin (E,F) and BLBP (G,H) staining in E18.5 embryos indicated that neural progenitors were more loosely organized in the VZ/SVZ. Neurons of the cortical plate were disorganized in the absence of <i>Usp9x</i> (J) compared with littermates (I). Nissl stain of <i>Usp9x^+/Y</i> (A,C,G) and <i>Usp9x^−/Y</i> (B,D,H) in E16.5 embryos (A–D, G–H). V = ventricle. Scale bar = 100 µm (A), 50 µm (C), 40 µm (E), 100 µm (G), 40 µm (I).</p