scholarly journals Neutral Sphingomyelinase 1 Deficiency in the Mouse Causes No Lipid Storage Disease

2002 ◽  
Vol 22 (11) ◽  
pp. 3633-3638 ◽  
Author(s):  
Markus Zumbansen ◽  
Wilhelm Stoffel

ABSTRACT Sphingomyelin is a major lipid in the bilayer of subcellular membranes of eukaryotic cells. Different sphingomyelinases catalyze the initial step in the catabolism of sphingomyelin, the hydrolysis to phosphocholine and ceramide. Sphingomyelinases have been postulated to generate ceramide as a lipophilic second messenger in intracellular signaling pathways involved in cell proliferation, differentiation, or apoptosis. To elucidate the function of the first cloned Mg2+-dependent, neutral sphingomyelinase (nSMase 1) in sphingomyelin catabolism and its potential role in signaling processes in a genetic and molecular approach, we have generated an nSMase 1-null mutant mouse line by gene targeting. The nSMase 1-deficient mice show an unconspicuous phenotype and no accumulation or changed metabolism of sphingomyelin or other lipids, despite grossly reduced nSMase activity in all organs except brain. We also addressed the recent proposal that nSMase 1 possesses lysophospholipase C activity. The unaltered metabolism of lysophosphatidylcholine or lyso-platelet-activating factor excludes the proposed role of nSMase 1 as a lysophospholipase C.

2014 ◽  
Vol 12 (12) ◽  
pp. 2054-2064 ◽  
Author(s):  
W.-L. Tseng ◽  
T.-H. Chen ◽  
C.-C. Huang ◽  
Y.-H. Huang ◽  
C.-F. Yeh ◽  
...  

2005 ◽  
Vol 73 (4) ◽  
pp. 2515-2523 ◽  
Author(s):  
Adriano L. S. Souza ◽  
Ester Roffê ◽  
Vanessa Pinho ◽  
Danielle G. Souza ◽  
Adriana F. Silva ◽  
...  

ABSTRACT In human schistosomiasis, the concentrations of the chemokine macrophage inflammatory protein 1α (MIP-1α/CCL3) is greater in the plasma of patients with clinical hepatosplenic disease. The objective of the present study was to confirm the ability of CCL3 to detect severe disease in patients classified by ultrasonography (US) and to evaluate the potential role of CCL3 in Schistosoma mansoni-infected mice. CCL3 was measured by enzyme-linked immunosorbent assay in the plasma of S. mansoni-infected patients. CCL3-deficient mice were infected with 25 cercariae, and various inflammatory and infectious indices were evaluated. The concentration of CCL3 was higher in the plasma of S. mansoni-infected than noninfected patients. Moreover, CCL3 was greater in those with US-defined hepatosplenic than with the intestinal form of the disease. In CCL3-deficient mice, the size of the granuloma and the liver eosinophil peroxidase activity and collagen content were diminished compared to wild-type mice. In CCL3-deficient mice, the worm burden after 14 weeks of infection, but not after 9 weeks, was consistently smaller. The in vitro response of mesenteric lymph node cells to antigen stimulation was characterized by lower levels of interleukin-4 (IL-4) and IL-10. CCL3 is a marker of disease severity in infected humans, and experimental studies in mice suggest that CCL3 may be a causative factor in the development of severe schistosomiasis.


2001 ◽  
Vol 69 (10) ◽  
pp. 5991-5996 ◽  
Author(s):  
M. Audrey Koay ◽  
John W. Christman ◽  
Brahm H. Segal ◽  
Annapurna Venkatakrishnan ◽  
Thomas R. Blackwell ◽  
...  

ABSTRACT Reactive oxygen species (ROS) are thought to be involved in intracellular signaling, including activation of the transcription factor NF-κB. We investigated the role of NADPH oxidase in the NF-κB activation pathway by utilizing knockout mice (p47phox−/−) lacking the p47phox component of NADPH oxidase. Wild-type (WT) controls and p47phox−/−mice were treated with intraperitoneal (i.p.) Escherichia coli lipopolysaccharide (LPS) (5 or 20 μg/g of body weight). LPS-induced NF-κB binding activity and accumulation of RelA in nuclear protein extracts of lung tissue were markedly increased in WT compared to p47phox−/− mice 90 min after treatment with 20 but not 5 μg of i.p. LPS per g. In another model of lung inflammation, RelA nuclear translocation was reduced in p47phox−/− mice compared to WT mice following treatment with aerosolized LPS. In contrast to NF-κB activation in p47phox−/− mice, LPS-induced production of macrophage inflammatory protein 2 in the lungs and neutrophilic lung inflammation were not diminished in these mice compared to WT mice. We conclude that LPS-induced NF-κB activation is deficient in the lungs of p47phox−/− mice compared to WT mice, but this abnormality does not result in overt alteration in the acute inflammatory response.


1995 ◽  
Vol 6 (2) ◽  
pp. 119-131 ◽  
Author(s):  
K.R. Purushotham ◽  
M.G. Humphreys-Beher

Tyrosine phosphorylation and the intracellular signaling processes associated with it have been the focus of intense study due to its importance in the regulation of biological processes as diverse as cell proliferation and cell differentiation. While much of what we now understand has been derived from the study of cell lines and tumor cells, the salivary glands provide a model to examine the effects of tyrosine kinases and tyrosine phosphatases in a normal differentiated tissue. This review will focus, therefore, on the role tyrosine kinases and phosphatases play in inducing the transition from stasis to active proliferation and their potential role in mediating secretory function of the salivary glands.


Blood ◽  
2012 ◽  
Vol 119 (23) ◽  
pp. 5575-5583 ◽  
Author(s):  
Norifumi Sawamukai ◽  
Atsushi Satake ◽  
Amanda M. Schmidt ◽  
Ian T. Lamborn ◽  
Priti Ojha ◽  
...  

Abstract FoxP3+ regulatory T cells (Tregs) suppress GVHD while preserving graft-versus-tumor effects, making them an attractive target for GVHD therapy. The donor-derived Treg pool can potentially be derived from the expansion of preexisting natural Tregs (nTregs) or from de novo generation of inducible Tregs (iTregs) from donor Tconvs in the transplantation recipient. Using an MHC-mismatched model of acute GVHD, in the present study we found that the Treg pool was comprised equally of donor-derived nTregs and iTregs. Experiments using various combinations of T cells from wild-type and FoxP3-deficient mice suggested that both preexisting donor nTregs and the generation of iTregs in the recipient mice contribute to protection against GVHD. Surprisingly, CD8+FoxP3+ T cells represented approximately 70% of the iTreg pool. These CD8+FoxP3+ T cells shared phenotypic markers with their CD4+ counterparts and displayed suppressive activity, suggesting that they were bona fide iTregs. Both CD4+ and CD8+ Tregs appeared to be protective against GVHD-induced lethality and required IL-2 and TGFβ receptor expression for their generation. These data illustrate the complex makeup of the donor-derived FoxP3+ Treg pool in allogeneic recipients and their potential role in protection against GVHD.


2013 ◽  
Vol 33 (2) ◽  
pp. 462-468 ◽  
Author(s):  
JIANHUA WU ◽  
YANHONG XIAO ◽  
JUANG LIU ◽  
HONG YANG ◽  
XIAOMIN DONG ◽  
...  

2015 ◽  
Vol 23 (11) ◽  
pp. 2017-2026 ◽  
Author(s):  
L.J. Moilanen ◽  
M. Hämäläinen ◽  
E. Nummenmaa ◽  
P. Ilmarinen ◽  
K. Vuolteenaho ◽  
...  

2020 ◽  
Vol 64 (4) ◽  
Author(s):  
Sonia Fantone ◽  
Giovanni Tossetta ◽  
Rodolfo Montironi ◽  
Martina Senzacqua ◽  
Daniela Marzioni ◽  
...  

Ciliary neurotrophic factor (CNTF) is a member of interleukin-6 type cytokine family. The CNTF receptor complex is a heterodimer including gp130 and CNTF receptor α (CNTFRα) proteins triggering the activation of multiple intracellular signaling pathways including AKT/PI3K, MAPK/ERK and Jak/STAT pathways. At present no data are available on the localization of CNTF and CNTFRα in prostate as well as on the role of CNTF in this organ. In this study we have analyzed the localization of CNTF and CNTFRα by immunohistochemistry and we have used PWR-1E cell line as a model for normal glandular cell to investigate the role of this cytokine. Our results show that CNTF and CNTFRa are expressed in the staminal compart of the prostate and that CNTF selectively inhibits ERK pathway. In conclusion, we suggest that CNTF could be considered as key molecule to maintenance epithelium homeostasis via pERK downregulation by an autocrine mechanism. Further CNTF studies in prostate cancer could be useful to verify the potential role of this cytokine in carcinogenesis.


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