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209. YopH of Yersinia pseudotuberculosis interrupts early phosphotyrosine signalling associated with phagocytosis.

Author

Andersson, K, Carballeira Suarez, N, Magnusson, K E, Persson, C, Stendahl, O, Wolf-Watz, H, Fällman, M, Andersson, K, Carballeira Suarez, N, Magnusson, K E, Persson, C, Stendahl, O, Wolf-Watz, H, and Fällman, M

Abstract

The PTPase YopH of Yersinia is essential to the ability of these bacteria to block phagocytosis. Wild-type Yersinia pseudotuberculosis, but not the yopH mutant strain, resisted phagocytosis by J774 cells. Ingestion of a yopH mutant was dependent on tyrosine kinase activity. Transcomplementation with wild-type yopH restored the anti-phagocytic effect, whereas introduction of the gene encoding the catalytically inactive yopHC403A was without effect. The PTPase inhibitor orthovanadate impaired the anti-phagocytic effect of the wild-type strain, further demonstrating the importance of bacteria-derived PTPase activity for this event. The ability to resist phagocytosis indicates that the effect of the bacterium is immediately exerted when it becomes associated with the phagocyte. Within 30 s after the onset of infection, wild-type Y. pseudotuberculosis caused a YopH-dependent dephosphorylation of phosphotyrosine proteins in J774 cells. Furthermore, interaction of the cells with phagocytosable strains led to a rapid and transient increase in tyrosine phosphorylation of paxillin and some other proteins, an event dependent on the presence of the bacterial surface-located protein invasin. Co-infection with the phagocytosable strain and the wild-type strain abolished the induction of tyrosine phosphorylation. Taken together, the present findings demonstrate an immediate YopH-mediated dephosphorylation of macrophage phosphotyrosine proteins, suggesting that this PTPase acts by preventing early phagocytosis-linked signalling in the phagocyte.

Published
1996

210. Vibrio cholerae hemagglutinin/protease (HA/protease) causes morphological changes in cultured epithelial cells and perturbs their paracellular barrier function

Author

Wu, Z., Milton, Debra L.., Nybom, P., Sjö, A., Magnusson, K. E., Wu, Z., Milton, Debra L.., Nybom, P., Sjö, A., and Magnusson, K. E.

Abstract

In this report, we describe the cytotoxic activity of the cholera hemagglutinin/protease (HA/protease). A concentrated protein sample from the 37 degrees C overnight culture supernatant of CVD110, a delta ctxA, delta zot, delta Ace and hlyA::(ctxB mer) mutant of El Tor biotype Ogawa serotype strain E7946 caused morphological changes in cultured MDCK-I epithelial cells and altered their arrangement of filamentous actin (F-actin) and Zonula occludens-associated protein ZO-1. The drastic morphological changes can be inhibited by Zincov, a specific bacterial metalloprotease inhibitor. The cytotoxic fractions of the sample after FPLC gelfiltration fractionation showed two visible protein bands with molecular weights of approximately 34- and 32 kDa. Microsequencing of these two proteins revealed that they were the cholera HA/protease.

Published
1996
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224. No strong temporal relationship between obesity and multisite pain - results from a population-based 20-year follow-up study.

Author

Magnusson, K., Østerås, N., Mowinckel, P., Natvig, B., and Hagen, K.B.

Subjects
OBESITY, CHRONIC pain, FOLLOW-up studies (Medicine), POPULATION biology, SOCIODEMOGRAPHIC factors, BODY mass index
Abstract

Background Multisite pain and obesity are cross-sectionally related and are common conditions that may influence each other through socio-demographic, lifestyle and/or health-related factors. The aim of the present study was to examine the cross-sectional and prospective associations between overweight/obesity and multisite pain in a general population. Methods In a 20-year population-based prospective cohort study, persons aged 20-62 years in 1990 participated in postal surveys in 1990, 1994, 2004 and 2010 ( n = 855). Multisite pain was defined as reporting ≥ 2 number of pain sites ( NPS) on the Standardized Nordic Questionnaire. Overweight was defined as body mass index ( BMI) 25-30 kg/m2 and obesity as BMI ≥ 30 kg/m2. To exploit all measurement times, generalized estimating equation analyses adjusting for age, sex, educational and occupational status, smoking, sleep quality, mental distress and physical activity were employed. Results The mean age was 41 years at baseline and 57% were women. Overweight/obesity and NPS were significantly associated cross-sectionally. Being overweight/obese was associated with reporting future NPS ≥ 2 [overweight: odds ratio ( OR), 1.40, 95% confidence interval ( CI), 1.12-1.75, obese: OR, 1.54, 95% CI, 1.04-2.28]. Having NPS ≥ 2 was not associated with becoming overweight, but increased the OR for future obesity ( OR 1.27, 95% CI, 1.02, 1.59). Smoking was a confounder in this relationship. Conclusions Being overweight or obese was associated with future multisite pain, although the magnitude of the association was small and the dose-response relationship observed in cross-sectional analyses disappeared in prospective analyses. There was less evidence that having multisite pain was a predictor of future overweight/obesity. [ABSTRACT FROM AUTHOR]

Published
2014
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