scholarly journals A Novel Role for the Receptor of the Complement Cleavage Fragment C5a, C5aR1, in CCR5-Mediated Entry of HIV into Macrophages

2016 ◽  
Vol 32 (4) ◽  
pp. 399-408 ◽  
Author(s):  
Maria E. Moreno-Fernandez ◽  
Julio Aliberti ◽  
Sander Groeneweg ◽  
Jörg Köhl ◽  
Claire A. Chougnet
Keyword(s):  
Cleavage Fragment

scholarly journals Expression of a naturally occurring angiotensin AT1 receptor cleavage fragment elicits caspase-activation and apoptosis

2011 ◽  
Vol 301 (5) ◽  
pp. C1175-C1185 ◽  
Author(s):  
Julia L. Cook ◽  
Akannsha Singh ◽  
Dawn deHaro ◽  
Jawed Alam ◽  
Richard N. Re
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Fold Increase ◽  
Muscle Cells ◽  
Cell Types ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Breast Adenocarcinoma ◽  
Protein Fusion ◽  
Cleavage Fragment ◽  
Carboxy Terminal

Several transmembrane receptors are documented to accumulate in nuclei, some as holoreceptors and others as cleaved receptor products. Our prior studies indicate that a population of the 7-transmembrane angiotensin type-1 receptor (AT1R) is cleaved in a ligand-augmented manner after which the cytoplasmic, carboxy-terminal cleavage fragment (CF) traffics to the nucleus. In the present report, we determine the precise cleavage site within the AT1R by mass spectrometry and Edman sequencing. Cleavage occurs between Leu(305) and Gly(306) at the junction of the seventh transmembrane domain and the intracellular cytoplasmic carboxy-terminal domain. To evaluate the function of the CF distinct from the holoreceptor, we generated a construct encoding the CF as an in-frame yellow fluorescent protein fusion. The CF accumulates in nuclei and induces apoptosis in CHO-K1 cells, rat aortic smooth muscle cells (RASMCs), MCF-7 human breast adenocarcinoma cells, and H9c2 rat cardiomyoblasts. All cell types show nuclear fragmentation and disintegration, as well as evidence for phosphotidylserine displacement in the plasma membrane and activated caspases. RASMCs specifically showed a 5.2-fold increase ( P < 0.001) in CF-induced active caspases compared with control and a 7.2-fold increase ( P < 0.001) in cleaved caspase-3 (Asp174). Poly(ADP-ribose)polymerase was upregulated 4.8-fold ( P < 0.001) in CF expressing cardiomyoblasts and colocalized with terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). CF expression also induces DNA laddering, the gold-standard for apoptosis in all cell types studied. CF-induced apoptosis, therefore, appears to be a general phenomenon as it is observed in multiple cell types including smooth muscle cells and cardiomyoblasts.

Regulation of apoptosis in the endocardial cushions of the developing chick heart

2002 ◽  
Vol 282 (6) ◽  
pp. C1348-C1360 ◽  
Author(s):  
William M. Keyes ◽  
Esmond J. Sanders
Keyword(s):  
Heart Development ◽  
Time Course ◽  
Nuclear Staining ◽  
Caspase 9 ◽  
Endocardial Cushions ◽  
Similar Time ◽  
Cleavage Fragment ◽  
Protein Levels ◽  
Developing Heart

During the early stages of heart development, there are two main foci of cell death: outflow tract (OT) and atrioventricular (AV) endocardial cushions. These tissues contribute to the septa and valves of the mature heart and receive cell populations from neural crest (NC) cell migration and epicardial cell invasion. We examined embryonic chick hearts for expression, in the cushions, of bcl-2 family members, caspase-9, and the caspase substrate poly(ADP-ribose) polymerase. Antiapoptotic bcl-2 is expressed heavily in the OT and AV regions throughout embryonic days (ED) 4–7, with a decrease in levels at ED 4 and 5 in OT and AV cushions, respectively. Proapoptotic bax predominantly associated with the prongs of the NC-derived aorticopulmonary (AP) septum but was expressed throughout the AV cushions. Proapoptotic bak also associated with the prongs of the AP septum in the OT, while protein levels were upregulated at ED 4–5 and 4–6 in OT and AV cushions, respectively. Bid expression showed a similar time course. We found the 10-kDa cleavage fragment of active caspase-9 at ED 4–8 and 5–8 in OT and AV cushions, respectively, and the 24-kDa cleavage fragment of poly(ADP-ribose) polymerase throughout ED 3–8 and 7–8 in OT and AV cushions, respectively. Caspase-3 cleavage occurred throughout the time period examined. Using cushion cell cultures, we found that inhibitors of caspases-3 and -9 and a universal caspase inhibitor significantly reduced apoptosis, as did retroviral overexpression of bcl-2 using an RCAS expression vector. Premigratory NC cells were fluorescently labeled in vivo with 1,1-didodecyl-3,3,3′,3′-tetramethylindocarbocyanine. Subsequent nuclear staining of cushion cells with 4,6-diamidino-2-phenylindole revealed the presence of apoptotic nuclei in the NC cells in the OT cushions and in the prongs of the AP septum. These results demonstrate a developmentally regulated role for the bcl-2 and the caspase families of molecules in the endocardial cushions of the developing heart and lend support to the possibility that some of the dying cells in the cushions are derived from the NC.

Inhibition of Tau Polymerization by Its Carboxy-Terminal Caspase Cleavage Fragment†

Biochemistry ◽  
2003 ◽  
Vol 42 (27) ◽  
pp. 8325-8331 ◽  
Author(s):  
R. W. Berry ◽  
A. Abraha ◽  
S. Lagalwar ◽  
N. LaPointe ◽  
T. C. Gamblin ◽  
...  
Keyword(s):  
Caspase Cleavage ◽  
Cleavage Fragment ◽  
Carboxy Terminal ◽  
Tau Polymerization

scholarly journals Bax-type Apoptotic Proteins Porate Pure Lipid Bilayers through a Mechanism Sensitive to Intrinsic Monolayer Curvature

2002 ◽  
Vol 277 (51) ◽  
pp. 49360-49365 ◽  
Author(s):  
Gorka Basañez ◽  
Juanita C. Sharpe ◽  
Jennifer Galanis ◽  
Teresa B. Brandt ◽  
J. Marie Hardwick ◽  
...  
Keyword(s):  
Lipid Bilayers ◽  
Mitochondrial Membrane ◽  
Pore Formation ◽  
Membrane Binding ◽  
Membrane Permeabilization ◽  
Outer Mitochondrial Membrane ◽  
Intrinsic Curvature ◽  
Differential Effects ◽  
Cleavage Fragment ◽  
Induced Changes

During apoptosis, Bax-type proteins permeabilize the outer mitochondrial membrane to release intermembrane apoptogenic factors into the cytosol via a poorly understood mechanism. We have proposed that Bax and ΔN76Bcl-xL(the Bax-like cleavage fragment of Bcl-xL) function by forming pores that are at least partially composed of lipids (lipidic pore formation). Since the membrane monolayer must bend during lipidic pore formation, we here explore the effect of intrinsic membrane monolayer curvature on pore formation. Nonlamellar lipids with positive intrinsic curvature such as lysophospholipids promoted membrane permeabilization, whereas nonlamellar lipids with negative intrinsic curvature such as diacylglycerol and phosphatidylethanolamine inhibited membrane permeabilization. The differential effects of nonlamellar lipids on membrane permeabilization were not correlated with lipid-induced changes in membrane binding or insertion of Bax or ΔN76Bcl-xL. Altogether, these results are consistent with a model whereby Bax-type proteins change the bending propensity of the membrane to form pores comprised at least in part of lipids in a structure of net positive monolayer curvature.

scholarly journals Placental HTRA1 Protease Cleaves Alpha-1-Antitrypsin and Generates Neonatal NET-Inhibitory Factor

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 273-273
Author(s):  
Robert A. Campbell ◽  
Mark Cody ◽  
Yasuhiro Kosaka ◽  
Heather D Campbell ◽  
Christian Yost
Keyword(s):  
Mass Spectrometry ◽  
Escherichia Coli ◽  
Reactive Oxygen Species ◽  
Reactive Oxygen Species Generation ◽  
Oxygen Species ◽  
Carboxy Terminus ◽  
Bacterial Killing ◽  
Fetal Circulation ◽  
Cleavage Fragment ◽  
Alpha 1 Antitrypsin

Abstract BACKGROUND: Neutrophil extracellular traps (NET) are extracellular lattices of decondensed chromatin associated with anti-microbial proteins and degradative enzymes released by polymorphonuclear leukocytes (PMN) to trap and kill invading microbes. Dysregulated NET formation, however, contributes to inflammatory tissue damage. We have identified a novel NET-inhibitory peptide, neonatal NET-Inhibitory Factor (nNIF), present in the fetal circulation. nNIF is formed as a carboxy-terminus cleavage fragment of alpha-1 antitrypsin (AAT), an abundant, circulating protease inhibitor with homologs in human and mouse blood. However, the exact mechanisms by which nNIF is generated in fetal and neonatal blood remains unknown. OBJECTIVE: High temperature requirement A 1 (HTRA1) is expressed in the placenta during fetal development and inhibits AAT. We hypothesized that placentally expressed HTRA1, a serine protease, regulates the formation of NET-inhibitory peptides, such as nNIF, through cleavage of AAT. DESIGN/METHODS: Term and preterm placenta were lysed and probed for HTRA1 expression. HTRA1 and AAT plasma expression from term and preterm infants and adults were determined by ELISA. Recombinant, bioactive HTRA1 or placenta-eluted HTRA1 were incubated with AAT and the generation of carboxy-terminus fragments of AAT was assessed using western blotting and mass spectrometry. Fragments of AAT generated by HTRA1 were incubated with LPS-stimulated PMNs and NET formation was examined qualitatively using live cell imaging and quantitatively using a high throughput fluorescence assay. The effect of the HTRA-AAT cleavage fragment on reactive oxygen species generation, neutrophil chemotaxis, phagocytosis, and bacterial killing was measured using flow cytometry, a modified Boyden chamber asssay, neutrophil labeled Escherichia coli uptake assay, and a bacterial killing assay with a pathogenic strain of Escherichia coli, respectively. Finally, NET formation was evaluated qualitatively and quantitatively in murine PMNs isolated from neonatal WT and HTRA1-/- pups between 1-3, 4-6 and 7-10 days after birth to determine when PMNs become NET-competent. RESULTS: Term and preterm infant placentas express HTRA1, and we detected significantly (p<0.05) higher levels of HTRA1 in plasma from term (465.1±71.8 µg/mL) and preterm (385.9±71.3 µg/mL) infant cord blood compared to adults (58.6±11.6 µg/mL). Recombinant, bioactive HTRA1 and placenta-derived HTRA1 incubated with AAT generate a 4kD AAT fragment based on western blot and mass spectrometry similar to the nNIF fragment found in cord blood from term and preterm infants. Pre-incubation of this fragment with LPS-stimulated PMNs significantly inhibits NET formation (p<0.05). The cleavage fragment from HTRA1-AAT, however, has no effect on reactive oxygen species generation, chemotaxis, or phagocytosis. However, incubation of this fragment with LPS-stimulated PMNs significantly (p<0.05) reduces NET-associated bacterial killing by 62% compared to a scrambled HTRA-AAT control peptide. In addition, the HTRA1-AAT fragment significantly (p<0.05) reduces nuclear decondensation by 93% compared to LPS-stimulated PMN, suggesting this fragment inhibits PAD4 activation similar to other NIFs previously examined. Neonatal murine plasma contains a 4kD AAT fragment which inhibits NET formation by adult mouse PMNs, indicating that nNIF generation is conserved in mice. Neonatal PMNs stimulated with LPS exhibit delayed NET formation following birth with PMNs becoming NET-competent by day 8 of life. However, neonatal PMNs from pups born from HTRA1-/- deficient mice generate significantly (p<0.05) more NETs between day 4-6 of life compared to WT controls, suggesting that HTRA1 regulates NET formation through nNIF production. CONCLUSIONS: Placental HTRA1 interacts with AAT to generate a carboxy-terminus cleavage fragment of AAT with identical NET-inhibitory properties to nNIF. Our data strongly indicate that placental HTRA1 generates nNIF in the fetal circulation. We speculate that nNIF participates in the required tolerance to new microbial antigens encountered during the transition to extrauterine life. Disclosures No relevant conflicts of interest to declare.

scholarly journals Directed vs. random: Does cadherin-11's extracellular cleavage fragment act as a chemoattractant to cranial neural crest cells?

2009 ◽  
Vol 331 (2) ◽  
pp. 470-471
Author(s):  
Catherine D. McCusker ◽  
James R. McCusker ◽  
Russell Neuner ◽  
Erin Kerdavid ◽  
Helene Cousin ◽  
...  
Keyword(s):  
Neural Crest ◽  
Neural Crest Cells ◽  
Cranial Neural Crest ◽  
Cleavage Fragment ◽  
Cranial Neural Crest Cells

scholarly journals Osteopontin Is Synthesized by Uterine Glands and a 45-kDa Cleavage Fragment Is Localized at the Uterine-Placental Interface Throughout Ovine Pregnancy1

2003 ◽  
Vol 69 (1) ◽  
pp. 92-98 ◽  
Author(s):  
Greg A. Johnson ◽  
Robert C. Burghardt ◽  
Margaret M. Joyce ◽  
Thomas E. Spencer ◽  
Fuller W. Bazer ◽  
...  
Keyword(s):  
Cleavage Fragment ◽  
Uterine Glands
Sign in / Sign up

Export Citation Format

Share Document