Regulation of steroidogenic function of luteal cells by thrombospondin and insulin in water buffalo (Bubalus bubalis)

2019 ◽  
Vol 31 (4) ◽  
pp. 751 ◽  
Author(s):  
Avishek Paul ◽  
Meeti Punetha ◽  
Sai Kumar ◽  
Arvind Sonwane ◽  
Vikrant S. Chouhan ◽  
...  

The present study examined the effect of exogenous thrombospondin 1 (TSP1) on the steroidogenic function of luteal cells cultured invitro. Furthermore, the transcriptional interaction of insulin with TSP1 and its receptor, cluster of differentiation 36 (CD36) were also investigated. At the highest dose (500ngmL−1) TSP1 significantly downregulated the expression of the angiogenic marker von Willebrand factor (vWF) and progesterone production in cultured luteal cells. Moreover, the simultaneous upregulation in the expression of caspase 3 by exogenous TSP1 was consistent with a reduction in the number of viable luteal cells as determined by 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltertrazolium bromide (MTT) assay after 72h of culture. However, the expression of critical enzymes in the progesterone synthetic pathway was not significantly modulated by treatment with TSP1 in cultured luteal cells. Knocking out of endogenous TSP1 with the clustered regularly interspaced short palindromic repeats (CRISPR)/ CRISPRassociated protein9 (Cas9) system improved the viability of luteal cells as well as increasing progesterone production and decreasing caspase 3 activation. Insulin treatment suppressed the expression of TSP1 and CD36 in cultured luteal cells in a dose- and time-dependent manner. To conclude, TSP1 acts as a negative endogenous regulator of angiogenesis that attenuates progesterone production, possibly by reducing the number of luteal cells via apoptosis during luteal regression, whereas insulin as a luteinising signal may have inhibited the thrombospondin system for the efficient development of luteal function.

1992 ◽  
Vol 127 (3) ◽  
pp. 246-251 ◽  
Author(s):  
Yasunori Yoshimura ◽  
Yukio Nakamura ◽  
Fumitaka Ichikawa ◽  
Takahisa Oda ◽  
Masao Jinno ◽  
...  

The present study was undertaken to assess the ability of human corpora lutea to produce leukotriene B4 (LTB4). The maximum capacity of luteal cells to secrete progesterone was attained on day 4, and both the basal production and the responsiveness to hCG decreased thereafter. In contrast, the production of LTB4 by cultured luteal cells was significantly reduced on day 4, but increased thereafter. The basal concentration of LTB4 produced by luteal cells varied from 75 to 590 pg/105 cells/2 days. LTB4 production appeared to decrease concomitantly with increased-progesterone production in cultured luteal cells. Exposure to hCG decreased significantly LTB4 production by cultured luteal cells on day 4. An inhibitor of the lipoxygenase pathway, nordihydroguaiaretic acid (NDGA), inhibited LTB4 production in a dose-dependent manner. However, NDGA did not affect basal progesterone production by the cultured luteal cells. A significant inverse relationship existed between the accumulation rates of progesterone and LTB4 in the luteal cells. Furthermore, the addition of LTB4 inhibited progesterone production in a dose-dependent manner in both the presence and absence of hCG. In conclusion, LTB4 could be synthesized by human corpora lutea in vitro, and correlated inversely with the secretion rates of progesterone. These data suggest that LTB4 produced locally in the corpus luteum may be an important regulator in human luteal regression.


1996 ◽  
Vol 75 (04) ◽  
pp. 655-660 ◽  
Author(s):  
Mario Mazzucato ◽  
Luigi De Marco ◽  
Paola Pradella ◽  
Adriana Masotti ◽  
Francesco I Pareti

SummaryPorcine von Willebrand factor (P-vWF) binds to human platelet glycoprotein (GP) lb and, upon stirring (1500 rpm/min) at 37° C, induces, in a dose-dependent manner, a transmembrane flux of Ca2+ ions and platelet aggregation with an increase in their intracellular concentration. The inhibition of P-vWF binding to GP lb, obtained with anti GP lb monoclonal antibody (LJ-Ib1), inhibits the increase of intracellular Ca2+ concentration ([Ca2+]i) and platelet aggregation. This effect is not observed with LJ-Ib10, an anti GP lb monoclonal antibody which does not inhibit the vWF binding to GP lb. An anti GP Ilb-IIIa monoclonal antibody (LJ-CP8) shown to inhibit the binding of both vWF and fibrinogen to the GP IIb-IIIa complex, had only a slight effect on the [Ca2+]i rise elicited by the addition of P-vWF. No inhibition was also observed with a different anti GP IIb-IIIa monoclonal antibody (LJ-P5), shown to block the binding of vWF and not that of fibrinogen to the GP IIb-IIIa complex. PGE1, apyrase and indomethacin show a minimal effect on [Ca2+]i rise, while EGTA completely blocks it. The GP lb occupancy by recombinant vWF fragment rvWF445-733 completely inhibits the increase of [Ca2+]i and large aggregates formation. Our results suggest that, in analogy to what is seen with human vWF under high shear stress, the binding of P-vWF to platelet GP lb, at low shear stress and through the formation of aggregates of an appropriate size, induces a transmembrane flux of Ca2+, independently from platelet cyclooxy-genase metabolism, perhaps through a receptor dependent calcium channel. The increase in [Ca2+]i may act as an intracellular message and cause the activation of the GP IIb-IIIa complex.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Katarina D. Kovacevic ◽  
Stefan Greisenegger ◽  
Agnes Langer ◽  
Georg Gelbenegger ◽  
Nina Buchtele ◽  
...  

AbstractThe effect of conventional anti-platelet agents is limited in secondary stroke prevention, and their effects are blunted under high shear stress in the presence of increased levels of circulating von Willebrand factor (VWF). VWF is critically involved in thrombus formation at sites of stenotic extracranial/intracranial arteries. A third generation anti-VWF aptamer (BT200) has been generated which could be useful for secondary stroke prevention. To characterize the effects of BT200 in blood of patients with large artery atherosclerosis stroke (LAA). Blood samples were obtained from 33 patients with acute stroke or transient ischemic attack to measure inhibition of VWF activity and VWF-dependent platelet function. Patients who received clopidogrel or dual antiplatelet therapy did not differ in VWF dependent platelet function tests from aspirin treated patients. Of 18 patients receiving clopidogrel with or without aspirin, only 3 had a prolonged collagen adenosine diphosphate closure time, and none of the patients had ristocetin induced aggregation in the target range. BT200 concentration-dependently reduced median VWF activity from 178 to < 3%, ristocetin induced platelet aggregation from 40U to < 10U and prolonged collagen adenosine diphosphate closure times from 93 s to > 300 s. Baseline VWF activity correlated (r = 0.86, p < 0.001) with concentrations needed to reduce VWF activity to < 20% of normal, indicating that BT200 acts in a target concentration-dependent manner. Together with a long half-life supporting once weekly administration, the safety and tolerability observed in an ongoing phase I trial, and the existence of a reversal agent, BT200 is an interesting drug candidate.


Blood ◽  
2019 ◽  
Vol 133 (4) ◽  
pp. 356-365 ◽  
Author(s):  
Reinhard Schneppenheim ◽  
Natalie Hellermann ◽  
Maria A. Brehm ◽  
Ulrike Klemm ◽  
Tobias Obser ◽  
...  

Abstract The frequent von Willebrand factor (VWF) variant p.Phe2561Tyr is located within the C4 domain, which also harbors the platelet GPIIb/IIIa-binding RGD sequence. To investigate its potential effect on hemostasis, we genotyped 865 patients with coronary artery disease (CAD), 915 with myocardial infarction (MI), and 417 control patients (Ludwigshafen Risk and Cardiovascular Health Study) and performed functional studies of this variant. A univariate analysis of male and female carriers of the Tyr2561 allele aged 55 years or younger revealed an elevated risk for repeated MI (odds ratio, 2.53; 95% confidence interval [CI], 1.07-5.98). The odds ratio was even higher in females aged 55 years or younger, at a value of 5.93 (95% CI, 1.12-31.24). Cone and plate aggregometry showed that compared with Phe2561, Tyr2561 was associated with increased platelet aggregate size both in probands’ blood and with the recombinant variants. Microfluidic assays revealed that the critical shear rate for inducing aggregate formation was decreased to 50% by Tyr2561 compared with Phe2561. Differences in C-domain circular dichroism spectra resulting from Tyr2561 suggest an increased shear sensitivity of VWF as a result of altered association of the C domains that disrupts the normal dimer interface. In summary, our data emphasize the functional effect of the VWF C4 domain for VWF-mediated platelet aggregation in a shear-dependent manner and provide the first evidence that a functional variant of VWF plays a role in arterial thromboembolism.


2002 ◽  
Vol 88 (09) ◽  
pp. 421-426 ◽  
Author(s):  
Stefan Lethagen ◽  
Christina Isaksson ◽  
Charlotta Schaedel ◽  
Lars Holmberg

SummaryHereditary defects of the von Willebrand factor (VWF) gene cause von Willebrand’s disease (VWD) which shows great variability dependent on the nature and location of the mutation. We here describe the characteristics of a substitution of methionine for threonine 1156 in the D3 domain of the VWF, i.e. the domain involved in the intracellular multimerization of pro-VWF dimers. A VWD patient with severe symptoms was a compound heterozygote for the T1156M mutation and a null allele (Q2470X) on the other chromosome. This led to marked reduction of plasma VWF concentration to about 0.05 U/ml and an abnormality of VWF multimers as in type 2A VWD. Expression in vitro of the mutation demonstrated that 1156M-VWF is secreted from COS-7 cells in a much reduced amount and lacking large multimers. When coexpressed with normal VWF 1156M-VWF decreased the secretion of normal VWF in a dose-dependent manner, the secreted VWF showing all the multimers. Two relatives of the propositus were single heterozygotes for the T1156M mutation and were either asymptomatic or had the manifestations of mild type 1 VWD. The expression data and studies of platelet VWF indicate that the T1156M mutation results in intracellular retention of VWF rather than impaired synthesis. Three other members of the family were heterozygotes for the Q2470X mutation and demonstrated the variable expressivity of a null allele.


Blood ◽  
1990 ◽  
Vol 75 (3) ◽  
pp. 688-695 ◽  
Author(s):  
EM Paleolog ◽  
DC Crossman ◽  
JH McVey ◽  
JD Pearson

Abstract We examined the effect of cytokines on basal and agonist-stimulated release of von Willebrand factor (vWf) by human endothelial cells. Treatment of endothelial cells for up to 48 hours with human recombinant or purified interleukin 1 (IL-1) or human recombinant tumor necrosis factor-alpha (TNF-alpha) did not significantly affect constitutive secretion of vWf or intracellular levels of vWf, although basal prostacyclin (PGI2) production was markedly enhanced. In contrast, both IL-1 and TNF-alpha modulated vWf release in response to thrombin or phorbol ester. Pretreatment of endothelial cells for 2 hours with either cytokine enhanced by up to threefold the stimulatory effect of a subsequent 60-minute exposure to thrombin. Addition of cycloheximide (5 micrograms/mL) during the preincubation abolished this enhancement. Moreover, if the cytokine pretreatment time was extended to 24 hours, agonist-stimulated vWf release was significantly suppressed. Cytokine treatment for 2 or 24 hours had no detectable effect on levels of vWf messenger RNA. The effects of cytokines were not the result of contamination with bacterial lipopolysaccharide and were not attributable to endothelial cell injury. These results show that cytokines have little or no direct effect on vWf release from endothelial cells but can significantly modulate its acute release in response to other stimuli in a complex time- and dose-dependent manner.


2011 ◽  
Vol 227 (1) ◽  
pp. 194-203 ◽  
Author(s):  
Xiao-Hua Yuan ◽  
Cai-Ling Lu ◽  
Nan Yao ◽  
Li-Sha An ◽  
Bai-Qing Yang ◽  
...  

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3919-3919
Author(s):  
Zhou Zhou ◽  
Han Hyojeong ◽  
Miguel A. Cruz ◽  
Jose A. Lopez ◽  
Jing-fei Dong ◽  
...  

Abstract One of the hallmark events of sickle cell disease (SCD) is vasoocclusion and episodic pain crisis. Although the mechanism of vascular occlusion is very complicated, processes like thrombosis and thromboembolism have been recognized to play an important role in the development of such clinical manifestation in SCD. Studies have shown that the von Willebrand factor (VWF), especially the ultra-large (UL) multimers play a major role in vasoocclusion, which clearly indicates a possible impairment of the VWF-cleaving metalloproteae ADAMTS-13 in these patients with SCD. In a recent work, indeed we have mentioned that the plasma ADAMTS-13 in patients with SCD having normal antigen level showed 35% less protease activity than the normal. There may be several plasma factors responsible for the acquired deficiency of ADAMTS-13 in SCD. Since, the increasing evidences suggest that the elevated level of extracellular hemoglobin (Hb) in plasma parallely associated with the pathogenesis of SCD, we investigated the effects of extracellular Hb on VWF proteolysis by ADAMTS-13. We observed that purified Hb dose-dependently inhibited the ADAMTS-13 cleavage of recombinant(r) VWF and endothelial ULVWF multimers under static and flow conditions. Hb bound to VWF multimers in a saturation-dependent manner and more potently to the rVWFA2 domain (affinity Kd~24nM), which contains the cleavage site for ADAMTS-13. Hb bound also to the ADAMTS-13 (Kd~65nM), with 2.7 times less affinity than to VWFA2. The bindings were neither calcium-dependent nor affected by haptoglobin. However, it is the Hb-binding to VWF that prevented the substrate from being cleaved by ADAMTS-13. These in vitro findings are consistent with the in vivo observations in patients with SCD. An elevated level of extracellular Hb in plasma was inversely correlated (linear regression, r2 =0.6354) with the low activity of ADAMTS-13 in a cohort of ten adult patients with SCD (mean±SE, Hb 346±138 mg/l; activity 33.3±30%) compared to age and gender-matched normal individuals (n=10; Hb 24±8 mg/l; activity 76.2±16%). The data together suggest that patients with SCD suffer from acquired ADAMTS-13 deficiency, primarily because Hb competitively binds and inhibits the proteolysis of VWF multimers, leading to ULVWF accumulation on vascular endothelium and in circulation. The Hb-VWF interaction may therefore be considered as a therapeutic target for reducing thrombotic and vasoocclusive complications in patients with severe hemolysis such as those with SCD.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1415-1415
Author(s):  
Hanspeter Rottensteiner ◽  
Katalin Varadi ◽  
Susanne Vejda ◽  
Hartmut J. Ehrlich ◽  
Friedrich Scheiflinger ◽  
...  

Abstract Abstract 1415 A recombinant human CHO-expressed von Willebrand factor (rVWF) consisting of ultra-high molecular weight (UHMW) multimers resembles the VWF stored in Weibel-Palade bodies of endothelial cells. Once secreted into plasma, UHMW multimers are rapidly cleaved by ADAMTS13 and are usually missing in plasma-derived VWF (pdVWF). Here we analyzed in vitro whether the kinetics of cleavage of rVWF by ADAMTS13 is similar to that of pdVWF. The kinetics of ADAMTS13-mediated proteolysis of rVWF were explored under denaturing conditions (1.5 M urea) or under shear stress so as to expose the ADAMTS13 cleavage site of VWF. Multiple assays showed that rVWF was efficiently cleaved by ADAMTS13. UHMW multimers disappeared within seconds at physiological concentrations of ADAMTS13. Using lower concentrations of ADAMTS13 (10-30 mU/ml, equivalent to 1–3% of normal human plasma), UHMW were cleaved within 30 minutes. The typical satellite bands appeared very early in an ADAMTS13 dose-dependent manner. Virtually the same results were obtained when human plasma was used as a source for ADAMTS13. Although pdVWF differs from rVWF in its multimeric structure, the decrease in activity was similar for rVWF and pdVWF. Finally, the extent of ADAMTS13 cleavage was similar for rVWF and pdVWF when exposed to shear stress using a cone-plate viscometer. Our data clearly indicate that rVWF is a good substrate for ADAMTS13. Ongoing phase 1 studies demonstrated that rVWF is indeed processed by the protease when administered in humans with severe VWD. Disclosures: Rottensteiner: Baxter Innovations GmbH: Employment. Varadi:Baxter Innovations GmbH: Employment. Vejda:Baxter Innovations GmbH: Employment. Ehrlich:Baxter Innovations GmbH: Employment. Scheiflinger:Baxter Innovations GmbH: Employment. Schwarz:Baxter Innovations GmbH: Employment. Turecek:Baxter Innovations GmbH: Employment.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1414-1414
Author(s):  
Eva-Maria Muchitsch ◽  
Barbara Dietrich ◽  
Hanspeter Rottensteiner ◽  
Herbert Gritsch ◽  
Hartmut J. Ehrlich ◽  
...  

Abstract Abstract 1414 Von Willebrand factor (VWF) is cleaved by the plasma metalloprotease ADAMTS13 that regulates the hemostatic activity of VWF by limiting its multimeric size in the human system. We showed previously by in vitro and ex vivo studies that human recombinant VWF (rVWF) is virtually resistant to the proteolytic activity of murine and rat ADAMTS13, whereas ADAMTS13 from rabbits and cynomolgus monkeys is able to cleave human rVWF. Here we tested the pharmacological behavior of human rVWF in rabbits and cynomolgus monkeys. The animals were infused once with different doses of human rVWF. VWF antigen rose sharply in a dose-dependent manner (∼25 IU/ml VWF:Ag for the highest dose, 15 min after injection) and then declined gradually (∼7 IU/ml VWF:Ag for the highest dose, 18 hours after injection). By contrast, the ADAMTS13 activity did not show relevant changes throughout the entire test period in the rabbit or in the monkey samples, indicating that an excess of intravenously administered rVWF as the substrate does not exhaust its enzyme ADAMTS13. Most importantly, neither rabbits nor cynomolgus monkeys showed any exaggerated pharmacological or toxic effects upon rVWF administration. Even the administration of 14 daily doses of rVWF to cynomolgus monkeys did not lead to any toxicological effect. Our data indicate that rabbits and cynomolgus monkeys, two species with a sufficient rVWF cleavage capacity by endogenous ADAMTS13, are appropriate animal models for a meaningful preclinical evaluation of the rVWF product, which allows the therapeutic safety margins for human patients to be determined. Disclosures: Muchitsch: Baxter Innovations GmbH: Employment. Dietrich:Baxter Innovations GmbH: Employment. Rottensteiner:Baxter Innovations GmbH: Employment. Gritsch:Baxter Innovations GmbH: Employment. Ehrlich:Baxter Innovations GmbH: Employment. Turecek:Baxter Innovations GmbH: Employment. Schwarz:Baxter Innovations GmbH: Employment.


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