Protein tyrosine nitration in mouse peritoneal macrophages activated in vitro and in vivo: evidence against an essential role of peroxynitrite

2001 ◽  
Vol 15 (13) ◽  
pp. 2355-2364 ◽  
Author(s):  
SILVIA PFEIFFER ◽  
ACHIM LASS ◽  
KURT SCHMIDT ◽  
BERND MAYER1
2009 ◽  
Vol 6 (5) ◽  
pp. 387-392 ◽  
Author(s):  
Yinan Wang ◽  
Xueling Cui ◽  
Guixiang Tai ◽  
Jingyan Ge ◽  
Nan Li ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xiu Cai ◽  
Zhi-yu Zhang ◽  
Jin-tao Yuan ◽  
Dickson Kofi Wiredu Ocansey ◽  
Qiang Tu ◽  
...  

Abstract Background Human umbilical cord mesenchymal stem cell (hucMSC)-derived exosomes are recognized as novel cell-free therapeutic agents for inflammatory bowel disease (IBD), a condition caused by dysregulated intestinal mucosal immunity. In this event, macrophage pyroptosis, a process of cell death following the activation of NLRP3 (NOD-like receptor family, pyrin domain-containing 3) inflammasomes, is believed to partially account for inflammatory reactions. However, the role of macrophage pyroptosis in the process of hucMSC-derived exosomes alleviating colitis remains unknown. This study aimed at exploring the therapeutic effect and mechanism of hucMSC-derived exosomes on colitis repair. Methods In vivo, we used BALB/c mice to establish a dextran sulfate sodium (DSS)-induced colitis model and administrated hucMSC-derived exosomes intravenously to estimate its curative effect. Human myeloid leukemia mononuclear (THP-1) cells and mouse peritoneal macrophages (MPMs) were stimulated with lipopolysaccharides (LPS) and Nigericin to activate NLRP3 inflammasomes, which simulated an inflammation environment in vitro. A microRNA mimic was used to verify the role of miR-378a-5p/NLRP3 axis in the colitis repair. Results hucMSC-derived exosomes inhibited the activation of NLRP3 inflammasomes in the mouse colon. The secretion of interleukin (IL)-18, IL-1β, and Caspase-1 cleavage was suppressed, resulting in reduced cell pyroptosis. The same outcome was observed in the in vitro cell experiments, where the co-culture of THP-1 cells and MPMs with hucMSC-derived exosomes caused decreased expression of NLRP3 inflammasomes and increased cell survival. Furthermore, miR-378a-5p was highly expressed in hucMSC-derived exosomes and played a vital function in colitis repair. Conclusion hucMSC-derived exosomes carrying miR-378a-5p inhibited NLRP3 inflammasomes and abrogated cell pyroptosis to protect against DSS-induced colitis.


2000 ◽  
Vol 113 (16) ◽  
pp. 2821-2827 ◽  
Author(s):  
L. Quarmby

Recent biochemical studies of the AAA ATPase, katanin, provide a foundation for understanding how microtubules might be severed along their length. These in vitro studies are complemented by a series of recent reports of direct in vivo observation of microtubule breakage, which indicate that the in vitro phenomenon of catalysed microtubule severing is likely to be physiological. There is also new evidence that microtubule severing by katanin is important for the production of non-centrosomal microtubules in cells such as neurons and epithelial cells. Although it has been difficult to establish the role of katanin in mitosis, new genetic evidence indicates that a katanin-like protein, MEI-1, plays an essential role in meiosis in C. elegans. Finally, new proteins involved in the severing of axonemal microtubules have been discovered in the deflagellation system of Chlamydomonas.


2007 ◽  
Vol 18 (1) ◽  
pp. 129-141 ◽  
Author(s):  
Yasunari Takami ◽  
Tatsuya Ono ◽  
Tatsuo Fukagawa ◽  
Kei-ichi Shibahara ◽  
Tatsuo Nakayama

Chromatin assembly factor-1 (CAF-1), a complex consisting of p150, p60, and p48 subunits, is highly conserved from yeast to humans and facilitates nucleosome assembly of newly replicated DNA in vitro. To investigate roles of CAF-1 in vertebrates, we generated two conditional DT40 mutants, respectively, devoid of CAF-1p150 and p60. Depletion of each of these CAF-1 subunits led to delayed S-phase progression concomitant with slow DNA synthesis, followed by accumulation in late S/G2 phase and aberrant mitosis associated with extra centrosomes, and then the final consequence was cell death. We demonstrated that CAF-1 is necessary for rapid nucleosome formation during DNA replication in vivo as well as in vitro. Loss of CAF-1 was not associated with the apparent induction of phosphorylations of S-checkpoint kinases Chk1 and Chk2. To elucidate the precise role of domain(s) in CAF-1p150, functional dissection analyses including rescue assays were preformed. Results showed that the binding abilities of CAF-1p150 with CAF-1p60 and DNA polymerase sliding clamp proliferating cell nuclear antigen (PCNA) but not with heterochromatin protein HP1-γ are required for cell viability. These observations highlighted the essential role of CAF-1–dependent nucleosome assembly in DNA replication and cell proliferation through its interaction with PCNA.


2001 ◽  
Vol 281 (6) ◽  
pp. H2289-H2294 ◽  
Author(s):  
Illarion V. Turko ◽  
Sisi Marcondes ◽  
Ferid Murad

High levels of reactive species of nitrogen and oxygen in diabetes may cause modifications of proteins. Recently, an increase in protein tyrosine nitration was found in several diabetic tissues. To understand whether protein tyrosine nitration is the cause or the result of the associated diabetic complications, it is essential to identify specific proteins vulnerable to nitration with in vivo models of diabetes. In the present study, we have demonstrated that succinyl-CoA:3-oxoacid CoA-transferase (SCOT; EC 2.8.3.5 ) is susceptible to tyrosine nitration in hearts from streptozotocin-treated rats. After 4 and 8 wk of streptozotocin administration and diabetes progression, SCOT from rat hearts had a 24% and 39% decrease in catalytic activity, respectively. The decrease in SCOT catalytic activity is accompanied by an accumulation of nitrotyrosine in SCOT protein. SCOT is a mitochondrial matrix protein responsible for ketone body utilization. Ketone bodies provide an alternative source of energy during periods of glucose deficiency. Because diabetes results in profound derangements in myocardial substrate utilization, we suggest that SCOT tyrosine nitration is a contributing factor to this impairment in the diabetic heart.


1987 ◽  
Vol 166 (6) ◽  
pp. 1912-1917 ◽  
Author(s):  
A H Warfel ◽  
D Zucker-Franklin ◽  
B Frangione ◽  
J Ghiso

Cystatin C (gamma-trace) was found to be a constitutively secreted protein of isolated human monocytes and mouse peritoneal macrophages, as well as the histiocytic lymphoma cell lines U937, P388D.1, and J774. This proteinase inhibitor is not uniquely secreted by monocytes/macrophages, but was also identified in the conditioned media from several primary cells, including brain cells, and diverse established cell lines. In vitro treatment of resident mouse peritoneal macrophages with either LPS or IFN-gamma caused a downregulation in cystatin C secretion. Elaboration of this protein was also diminished by macrophages that had been stimulated by thioglycollate in vivo, and treatment of these cells with LPS led to further decline. It is suggested that, under some inflammatory conditions, downregulation of cystatin C may contribute to tissue pathology.


2009 ◽  
Vol 255 (1-2) ◽  
pp. 69-75 ◽  
Author(s):  
Jing Zhou ◽  
Guixiang Tai ◽  
Haiyan Liu ◽  
Jingyan Ge ◽  
Ye Feng ◽  
...  

1980 ◽  
Vol 151 (1) ◽  
pp. 101-114 ◽  
Author(s):  
M J Pabst ◽  
R B Johnston

After in vitro exposure to lipopolysaccharide (LPS) or muramyl dipeptide (MDP), cultured resident mouse peritoneal macrophages were primed to display enhanced generation of superoxide anion (O2-) in response to stimulation by phorbol myristate acetate (PMA) or opsonized zymosan. Priming with LPS (1 microgram/ml) produced a sevenfold enhancement of PMA-stimulated O2- generation; priming was detected within 30 min and persisted for at least 4 d. Exposure to MDP (1 muM) primed the macrophages to double their O2- release; the response was first observed after 4 h and persisted for at least 3 d. The priming response was not observed with stereoisomers of MDP, which are inactive as adjuvants. LPS and MDP appeared to work directly on the macrophages rather than indirectly by interacting with adherent lymphocytes: (a) Addition of nonadherent cell populations that contained lymphocytes had no effect on the response. (b) The response was normal with cells from nude mice, which lack mature T lymphocytes. (c) Macrophages from C3H/HeJ mice, whose B lymphocytes fail to respond to LPS, were weak in their response to priming LPS; the addition of normal (C3Heb/FeJ) nonadherent cells had no effect on this weak response. (d) The macrophage-like cell line J774.1 also showed enhanced O2--generating capacity after a 4-h exposure to LPS or MDP. The O2--generating capacity of macrophages primed with LPS in vitro was equivalent to that previously observed with cells elicited in vivo by injection of LPS or activated by infection with Bacille Calmette-Guérin. The data suggest that previous exposure to bacterial products could prime macrophages to respond with increased production of toxic oxygen metabolites on contact with invading microorganisms or tumor cells.


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