scholarly journals Dose-dependent Inhibition of Gynecophoral Canal Protein Gene Expression in Vitro in the Schistosome (Schistosoma japonicum) by RNA Interference

2005 ◽  
Vol 37 (6) ◽  
pp. 386-390 ◽  
Author(s):  
Guo-Feng Cheng ◽  
Jiao-Jiao Lin ◽  
Yi Shi ◽  
You-Xin Jin ◽  
Zhi-Qiang Fu ◽  
...  
Keyword(s):  
Schistosoma Japonicum ◽  
Protein Gene ◽  
Female Worm ◽  
Transcript Level ◽  
Pcr Analysis ◽  
Rt Pcr ◽  
Male Worm ◽  
Dependent Inhibition ◽  
Dose Dependent

Abstract The gynecophoral canal protein gene SjGCP of Schistosoma japonicum that is necessary for the pairing between the male and female worms is specifically expressed in the adult male worm. This protein is widely distributed in the adult female worm after pairing. Reverse transcription-polymerase chain reaction (RT-PCR) and immunofluorescence were employed to analyze the relationship between the RNAi effect and dsRNA dosage in the parasites. The results revealed that the inhibition of SjGCP expression by siRNA is dose-dependent. RT-PCR analysis showed that the SjGCP transcript level was reduced by 75% when 100 nM dsRNA was applied.

Differences between antigenic determinants of pig and cat zona pellucida proteins

Reproduction ◽  
2000 ◽  
pp. 15-23 ◽  
Author(s):  
K Jewgenow ◽  
M Rohleder ◽  
I Wegner
Keyword(s):  
In Vitro Fertilization ◽  
Zona Pellucida ◽  
Antigenic Determinants ◽  
Vitro Fertilization ◽  
Contraceptive Vaccine ◽  
Sperm Binding ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
Dose Dependent

Despite many efforts, the control of reproduction in feral cat populations is still a problem in urban regions around the world. Immunocontraception is a promising approach; thus the present study examined the suitability of the widely used pig zona pellucida proteins (pZP) for contraception in feral domestic cats. Purified zona pellucida proteins obtained from pig and cat ovaries were used to produce highly specific antisera in rabbits. Antibodies against pZP raised in rabbits or lions were not effective inhibitors of either in vitro sperm binding (cat spermatozoa to cat oocytes) or in vitro fertilization in cats, whereas antibodies against feline zona pellucida proteins (fZP) raised in rabbits showed a dose-dependent inhibition of in vitro fertilization. Immunoelectrophoresis, ELISA and immunohistology of ovaries confirmed these results, showing crossreactivity of anti-fZP sera to fZP and to a lesser extent to pZP, but no interaction of anti-pZP sera with fZP. It is concluded that cat and pig zonae pellucidae express a very small number of shared antigenic determinants, making the use of pZP vaccine in cats questionable. A contraceptive vaccine based on feline zona pellucida determinants will be a better choice for the control of reproduction in feral cats if immunogenity can be achieved.

scholarly journals In VitroActivities of Hexaazatrinaphthylenes against Leishmania spp.

2015 ◽  
Vol 59 (5) ◽  
pp. 2867-2874 ◽  
Author(s):  
Atteneri López-Arencibia ◽  
Daniel García-Velázquez ◽  
Carmen M. Martín-Navarro ◽  
Ines Sifaoui ◽  
María Reyes-Batlle ◽  
...  
Keyword(s):  
Therapeutic Agents ◽  
Content Type ◽  
Inhibition Effect ◽  
Intracellular Amastigotes ◽  
Dependent Inhibition ◽  
Leishmania Spp ◽  
Dose Dependent Inhibition ◽  
Dose Dependent ◽  
Potential Use

ABSTRACTThein vitroactivity of a novel group of compounds, hexaazatrinaphthylene derivatives, against two species ofLeishmaniais described in this study. These compounds showed a significant dose-dependent inhibition effect on the proliferation of the parasites, with 50% inhibitory concentrations (IC50s) ranging from 1.23 to 25.05 μM against the promastigote stage and 0.5 to 0.7 μM against intracellular amastigotes. Also, a cytotoxicity assay was carried out to in order to evaluate the possible toxic effects of these compounds. Moreover, different assays were performed to determine the type of cell death induced after incubation with these compounds. The obtained results highlight the potential use of hexaazatrinaphthylene derivatives againstLeishmaniaspecies, and further studies should be undertaken to establish them as novel leishmanicidal therapeutic agents.

scholarly journals In vitro interactions of PGE and cAMP with murine and human erythroid precursors

Blood ◽  
1980 ◽  
Vol 56 (1) ◽  
pp. 74-79 ◽  
Author(s):  
GB Rossi ◽  
AR Migliaccio ◽  
G Migliaccio ◽  
F Lettieri ◽  
M Di Rosa ◽  
...  
Keyword(s):  
Inhibitory Action ◽  
Colony Growth ◽  
Inhibitory Influence ◽  
Adherent Cells ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
Dose Dependent ◽  
Stimulating Factor ◽  
In Vitro Interactions

Abstract Addition of prostaglandins of the E series (PGE1, PGE2) in methylcellulose cultures of murine marrow results in a dose-dependent inhibition of the cloning efficiency of both BFU-E and CFU-C. However, CFU-E growth is unaffected. The inhibitory action of PGE is progressively overcome by increasing amounts of colony-stimulating factor (CSF), and with some limitations, also of erythropoietin (Ep). Addition of PGF2 alpha' associated or not with indomethacin, does not exert any significant effect on these hemopoietic precursors. In an attempt to unvail the mechanism(s) underlying these phenomena, dibutyryl-cyclic AMP (db-cAMP), theophylline (an inhibitor of phosphodiesterase), or theophylline + PGE were plated at various concentrations. Both db-cAMP and theophylline induce an inhibitory influence on both BFU-E and CFU-C growth, which mimicks that by PGEs; additionally, theophylline potentiates the inhibitory action of PGE1. In all these studies, the CFU-E number was not significantly modified. PGE action on BFU-E proliferation is clearly species-dependent, since PGE1 addition to human marrow methylcellulose cultures induces a significant enhancement of the number of both BFU-E and CFU-E derived colonies. This action was abolished upon removal of adherent cells, thus suggesting that PGE1 evokes a release of factor(s) enhancing human erythroid colony growth by adherent cells.

Differential regulation by thyroid hormones of myosin heavy chain α and β mRNAs in the rat ventricular myocardium

1989 ◽  
Vol 122 (1) ◽  
pp. 193-200 ◽  
Author(s):  
N. K. Green ◽  
J. A. Franklyn ◽  
J. A. O. Ahlquist ◽  
M. D. Gammage ◽  
M. C. Sheppard
Keyword(s):  
Myosin Heavy Chain ◽  
Cardiac Myocytes ◽  
Heavy Chain ◽  
Ventricular Myocardium ◽  
Mhc Genes ◽  
Specific Effects ◽  
Dependent Inhibition ◽  
Dose Dependent

ABSTRACT The effect of tri-iodothyronine (T3) treatment on myocardial levels of α and β myosin heavy chain (MHC) mRNAs in the rat was defined in vivo and in vitro. Dose–response experiments were performed in intact hypothyroid and euthyroid rats; in addition, studies in vitro examined the effect of T3 on MHC mRNAs in neonatal cardiac myocytes in primary culture. Specific α and β MHC mRNAs were determined by Northern blot and dot hybridization to oligonucleotide probes complementary to the 3′ untranslated regions of the MHC genes. An increase in myocardial β MHC mRNA was demonstrated in hypothyroidism, accompanied by a reduction in α MHC mRNA. Marked differences in the sensitivity of α and β MHC mRNAs to T3 replacement were found; a dose-dependent increase in α mRNA was evident at 6 h after T3 treatment, in the absence of consistent effects on β mRNA, whereas 72 h after T3 replacement was commenced, stimulatory effects of T3 on α MHC mRNA, evident at all doses, were accompanied by a dose-dependent inhibition of β MHC mRNA. No effect of thyroid status on actin mRNA was found, indicating the specificity of MHC gene regulation. T3 treatment of cardiac myocytes in vitro exerted similar actions on MHC mRNAs to those found in vivo, with a more marked influence on α than β MHC mRNA. These studies of the action of T3 in vivo and in vitro have thus demonstrated specific effects of T3 on pretranslational regulation of the α and β MHC genes, influences which differ not only in terms of stimulation or inhibition, but also in magnitude of effect. Journal of Endocrinology (1989) 122, 193–200

The Effects Of Prostacyclin (PGI2) On Intravascular Platelet Aggregation

1981 ◽  
Author(s):  
G G Duncan ◽  
G Mallarkey ◽  
G M Smith
Keyword(s):  
Platelet Count ◽  
Guinea Pigs ◽  
Adenosine Diphosphate ◽  
Before And After ◽  
Dependent Inhibition ◽  
Induced Aggregation ◽  
Dose Dependent ◽  
Anaesthetised Rats

Intravascular aggregation can be measured by counting the number of circulating platelets before and after the injection of aggregation agents. The Technicon Autocounter was modified to count platelets continuously and connected via a double cannula in a carotid artery to an anaesthetised animal.Adenosine diphosphate (ADP) and collagen gave dose- dependent falls in the circulating platelet count when injected into rats, guinea pigs and rabbits. This enabled aggregation to be accurately quantitated in vivo.The infusion of PGI2 (0.25-1 ug/kg/min) in anaesthetised rats and rabbits produced a dose-dependent inhibition of the fall in platelet count produced by ADP and collagen. The formation of PGI2 can be inhibited in vitro by 15- hydroperoxyarachidonic acid (15HPAA). When 20 ug/kg/min of 15HPAA was infused into rats, aggregation produced by collagen was significantly increased suggesting that PGI2 is continuously formed by the rat vascular endothelium. This observation was confirmed by infusing 6-keto PGF1α antiserum. This antibody also prevented the inhibitory activity of PGI2 on collagen-induced aggregation. The study of continuous platelet counting in guinea pigs has been hampered by the occurrence of thrombocytopenia in certain animals. When 2 ug/kg/min of PGI2 was infused for 10 mins, a rise in the circulating platelet count to a steady plateau 4-5 × 105 platelets occurredThese experiments have shown that PGI2 will prevent aggregation by ADP and collagen and will reverse spontaneous thrombocytopenia and that PGI2 is continuously released from the vessels of anaesthetised rats.

scholarly journals On the Molecular Pharmacology of Resveratrol on Oxidative Burst Inhibition in Professional Phagocytes

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Radomír Nosáľ ◽  
Katarína Drábiková ◽  
Viera Jančinová ◽  
Tomáš Perečko ◽  
Gabriela Ambrožová ◽  
...  
Keyword(s):  
Oxidative Burst ◽  
Antioxidant Activities ◽  
Raw 264.7 Cells ◽  
Human Neutrophils ◽  
Nitrite Production ◽  
Inos Protein Expression ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
Dose Dependent

Resveratrol—3,5,4′-trihydroxystilbene—possesses antioxidant activitiesin vitro. It dose-dependently inhibited the generation of peroxyl, hydroxyl, peroxides, and lipid peroxidation products in cell free systems. Oxidative burst of whole human blood stimulated with PMA, fMLP, OpZ, and A23187 was inhibited in a concentration-dependent way, indicating suppression of both receptor and nonreceptor activated chemiluminescence by resveratrol. Results from isolated human neutrophils revealed that resveratrol was active extracellularly as well as intracellularly in inhibiting the generation of reactive oxygen species. Liberation of ATP and analysis of apoptosis showed that in the concentration of 100 μM, resveratrol did not change the viability and integrity of isolated neutrophils. Western blot analysis documented that resveratrol in concentrations of 10 and 100 μM significantly decreased PMA-induced phosphorylation of PKCα/βII. Dose-dependent inhibition of nitrite production and iNOS protein expression in RAW 264.7 cells indicated possible interference of resveratrol with reactive nitrogen radical generation in professional phagocytes. The results suggest that resveratrol represents an effective naturally occurring substance with potent pharmacological effect on oxidative burst of human neutrophils and nitric oxide production by macrophages. It should be further investigated for its pharmacological activity against oxidative stress in ischaemia reperfusion, inflammation, and other pathological conditions, particularly neoplasia.

Identification of a gene cluster for cell-surface genes of the SRS superfamily inNeospora caninumand characterization of the novelSRS9gene

Parasitology ◽  
2011 ◽  
Vol 138 (14) ◽  
pp. 1832-1842 ◽  
Author(s):  
V. RISCO-CASTILLO ◽  
V. MARUGÁN-HERNÁNDEZ ◽  
A. FERNÁNDEZ-GARCÍA ◽  
A. AGUADO-MARTÍNEZ ◽  
E. JIMÉNEZ-RUIZ ◽  
...  
Keyword(s):  
Western Blot ◽  
Gene Cluster ◽  
Neospora Caninum ◽  
Pcr Analysis ◽  
Rt Pcr ◽  
Specific Expression ◽  
Initial Characterization ◽  
Hydrophilic Region

SUMMARYHere we present the detection of a gene cluster forNeospora caninumsurface genes, similar to theToxoplasma gondiiSRS9 locus, and the cloning and characterization of the NcSRS9gene. PCR genome walking, using NcBSR4gene as a framework, allows the identification, upstream NcBSR4, of 2 sequences homologous to theSRS5and the Ubiquinol-cytochrome C reductase genes and, downstream NcBSR4, of an ORF of 1191 bp coding for a 396-amino acid polypeptide with 59% similarity to the TgSRS9 antigen. A putative 39-residue signal peptide was found at the NH2-terminus followed by a hydrophilic region, and a potential site for a glycosylphosphatidylinositol anchor at the COOH-terminus. A recombinant NcSRS9 protein was produced and was recognized on a Western blot by a low proportion of sera from a panel of naturally infected cows and calves. In addition, Western blot analysis using polyclonal anti-rNcSRS9 revealed stage-specific expression of NcSRS9 in bradyzoites but not in tachyzoites, and immunohistochemistry on brain from a congenitally infected calf showed NcSRS9 recognition in bradyzoites contained in tissue cysts. However, bradyzoite-specific expression of NcSRS9 could not be proven by immunofluorescence on bradyzoites obtainedin vitroand RT-PCR analysis showed no significant variations of NcSRS9transcripts duringin vitrotachyzoite-bradyzoite switch, probably due to incomplete maturity ofin vitrobradyzoites. Initial characterization of NcSRS9 in this study may lead to further studies for a better understanding ofN. caninumpersistence.

Effects of reactive oxygen and nitrogen metabolites on MCP-1-induced monocyte chemotactic activity in vitro

1999 ◽  
Vol 277 (3) ◽  
pp. L543-L549 ◽  
Author(s):  
Etsuro Sato ◽  
Keith L. Simpson ◽  
Matthew B. Grisham ◽  
Sekiya Koyama ◽  
Richard A. Robbins
Keyword(s):  
Protein Function ◽  
Inhibitory Effect ◽  
Chemotactic Activity ◽  
Dependent Manner ◽  
No Donor ◽  
Monocyte Chemoattractant Protein 1 ◽  
Dependent Inhibition ◽  
Monocyte Chemotaxis ◽  
Dose Dependent

Peroxynitrite, an oxidant generated by the interaction between superoxide and nitric oxide (NO), can nitrate tyrosine residues, resulting in compromised protein function. Monocyte chemoattractant protein-1 (MCP-1) is a chemokine that attracts monocytes and has a tyrosine residue critical for function. We hypothesized that peroxynitrite would alter MCP-1 activity. Peroxynitrite attenuated MCP-1-induced monocyte chemotactic activity (MCA) in a dose-dependent manner ( P < 0.05) but did not attenuate leukotriene B4 or complement-activated serum MCA. The reducing agents dithionite, deferoxamine, and dithiothreitol reversed the MCA inhibition by peroxynitrite, and exogenous l-tyrosine abrogated the inhibition by peroxynitrite. PAPA-NONOate, an NO donor, or superoxide generated by xanthine and xanthine oxidase did not show an inhibitory effect on MCA induced by MCP-1. The peroxynitrite generator 3-morpholinosydnonimine caused a concentration-dependent inhibition of MCA by MCP-1. Peroxynitrite reduced MCP-1 binding to monocytes and resulted in nitrotyrosine formation. These findings are consistent with nitration of tyrosine by peroxynitrite, with subsequent inhibition of MCP-1 binding to monocytes, and suggest that peroxynitrite may play a role in regulation of MCP-1-induced monocyte chemotaxis.

scholarly journals SMAD1/5 Signaling in the Early Equine Placenta Regulates Trophoblast Differentiation and Chorionic Gonadotropin Secretion

Endocrinology ◽  
2014 ◽  
Vol 155 (8) ◽  
pp. 3054-3064 ◽  
Author(s):  
Victoria Cabrera-Sharp ◽  
Jordan E. Read ◽  
Stephanie Richardson ◽  
Alycia A. Kowalski ◽  
Douglas F. Antczak ◽  
...  
Keyword(s):  
Chorionic Gonadotropin ◽  
Trophoblast Cells ◽  
Rt Pcr ◽  
Trophoblast Differentiation ◽  
Gonadotropin Secretion ◽  
Morphogenetic Protein ◽  
Dose Dependent

TGFβ superfamily proteins, acting via SMAD (Sma- and Mad-related protein)2/3 pathways, regulate placental function; however, the role of SMAD1/5/8 pathway in the placenta is unknown. This study investigated the functional role of bone morphogenetic protein (BMP)4 signaling through SMAD1/5 in terminal differentiation of primary chorionic gonadotropin (CG)-secreting trophoblast. Primary equine trophoblast cells or placental tissues were isolated from day 27–34 equine conceptuses. Detected by microarray, RT-PCR, and quantitative RT-PCR, equine chorionic girdle trophoblast showed increased gene expression of receptors that bind BMP4. BMP4 mRNA expression was 20- to 60-fold higher in placental tissues adjacent to the chorionic girdle compared with chorionic girdle itself, suggesting BMP4 acts primarily in a paracrine manner on the chorionic girdle. Stimulation of chorionic girdle-trophoblast cells with BMP4 resulted in a dose-dependent and developmental stage-dependent increase in total number and proportion of terminally differentiated binucleate cells. Furthermore, BMP4 treatment induced non-CG-secreting day 31 chorionic girdle trophoblast cells to secrete CG, confirming a specific functional response to BMP4 stimulation. Inhibition of SMAD2/3 signaling combined with BMP4 treatment further enhanced differentiation of trophoblast cells. Phospho-SMAD1/5, but not phospho-SMAD2, expression as determined by Western blotting was tightly regulated during chorionic girdle trophoblast differentiation in vivo, with peak expression of phospho-SMAD1/5 in vivo noted at day 31 corresponding to maximal differentiation response of trophoblast in vitro. Collectively, these experiments demonstrate the involvement of BMP4-dependent pathways in the regulation of equine trophoblast differentiation in vivo and primary trophoblast differentiation in vitro via activation of SMAD1/5 pathway, a previously unreported mechanism of TGFβ signaling in the mammalian placenta.

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