The protein C anticoagulant pathway plays a fundamental role in the control of coagulation system and inflammatory response. It has been well established that physiological levels of shear stress induce endothelial structural change and modulate gene and protein expression. However, the role of shear stress in protein C pathway remains unknown. In the present study, we evaluated the effect of shear stress on the activation of protein C as well as on the expression of endothelial protein C receptor (EPCR) and thrombomodulin (TM) in human umbilical vein endothelial cells (HUVECs) which were exposed to TNF-alpha alone, shear stress alone, and TNF-alpha under shear stress. We found: (1) Either TNF-alpha or shear stress alone significantly reduced EPCR expression and protein C activation in HUVECs; and simultaneous exposure of HUVECs to TNF-alpha and shear stress resulted in a further decrease of EPCR expression and protein C activation (P<0.05); (2) Simultaneous exposure of HUVECs to TNF-alpha and shear stress resulted in the increase of soluble EPCR level more significantly than did the exposure of HUVECs to either TNF-alpha or shear stress alone (P<0.05); (3) Shear stress significantly increased TM expression on HUVECs, whereas TNF-alpha inhibited TM expression; shear stress could strongly neutralize TNF-alpha's inhibitive effect on TM expression. We therefore conclude that shear stress may play an important role in protein C pathway, which may be fulfilled by regulating EPCR expression and TM expression in endothelial cells.
Antigens, CD ; genetics ; metabolism ; Biomechanical Phenomena ; Cells, Cultured ; Endothelial Cells ; cytology ; metabolism ; Endothelial Protein C Receptor ; Humans ; Protein C ; metabolism ; Receptors, Cell Surface ; genetics ; metabolism ; Shear Strength ; Stress, Mechanical ; Thrombomodulin ; genetics ; metabolism ; Umbilical Veins ; cytology

It has been demonstrated that the activated protein C (APC) plays an important role in the inhibition of inflammation. The activation of protein C can be significantly enhanced by the endothelial cell protein C receptor (EPCR). Previous studies proposed that the APC regulates the inflammatory response in endothelial cells by suppressing the expression of adhesion molecules and the secretion of chemokines and cytokines. However, the precise mechanism of the inhibitory effect of APC on inflammation is still poorly understood. In the present study, we evaluated the anti-inflammatory effect of recombinant human APC (rhAPC) and whether its inhibitory effect is conducted through the EPCR-dependent mechanism on human umbilical vein endothelial cells (HUVECs). By exposing HUVECs to: (1) TNF-alpha; (2) rhAPC plus TNF-alpha; (3) anti EPCR antibody that prevents rhAPC interaction with EPCR; (4) TNF-alpha plus anti EPCR antibody; (5) rhAPC plus TNF-alpha in the presence of anti EPCR antibody, we found that APC was able to significantly inhibit the TNF-alpha-induced secretion of cytokines such as IL-1beta and IL-8, as well as the expression of adhesion molecules such as ICAM-1, VCAM-1 and E-selction in HUVECs. These results reveal a novel pathway by which APC protects endothelial cells from inflammatory mediators through an EPCR-dependent mechanism.
Antigens, CD ; metabolism ; Cells, Cultured ; Cytokines ; metabolism ; Endothelial Protein C Receptor ; Human Umbilical Vein Endothelial Cells ; drug effects ; Humans ; Inflammation ; metabolism ; Protein C ; pharmacology ; Receptors, Cell Surface ; metabolism ; Tumor Necrosis Factor-alpha ; antagonists & inhibitors

Objective:To study the effect of COVID-19 on pregnancy outcomes and neonatal prognosis in Hubei Province.Method:s A retrospective comparison of the pregnancy outcomes was done between 16 women with COVID-19 and 45 women without COVID-19. Also, the results of laboratory tests, imaging examinations, and the 2019 novel coronavirus (2019-nCoV) nucleic acid test were performed in 10 cases of neonatal delivered from women with COVID-19.Result:s (1) Of the 16 pregnant women with COVID-19, 15 cases were ordinary type and 1 case was severe type. No one has progressed to critical pneumonia.The delivery method of the two groups was cesarean section, and the gestational age were (38.7±1.4) and (37.9±1.6) weeks,there was no significant difference between the two groups ( P>0.05). Also, there wee no significant differences in the intraoperative blood loss and birth weight of the newborn between the two groups (all P>0.05). (2) Ten cases of neonates delivered from pregnant women with COVID-19 were collected. The 2019-nCoV nucleic acid test were all negative.There were no significant differences in fetal distress, meconium-stained amniotic fluid, preterm birth, and neonatal asphyxia between the two groups (all P>0.05).(3) In the treatment of uterine contraction fatigue, carbetocin or carboprost tromethamine was used more in cesarean section for pregnant women with COVID-19 (1.3±0.6), compared with Non-COVID-19 group (0.5±0.7),the difference was statistically significant ( P=0.001). Conclusions:If there is an indication for obstetric surgery or critical illness of COVID-19 in pregnant women, timely termination of pregnancy will not increase the risk of premature birth and asphyxia of the newborn, but it is beneficial to the treatment and rehabilitation of maternal pneumonia. Preventive use of long-acting uterotonic agents could reduce the incidence of postpartum hemorrhage during surgery. 2019-nCoV infection has not been found in neonates delivered from pregnant women with COVID-19.