Human Stanniocalcin-1 Blocks TNF-α–Induced Monolayer Permeability in Human Coronary Artery Endothelial Cells

Abstract

Objective-Our previous studies revealed upregulation of stanniocalcin-1 (STC1) in cardiac vessels in dilated cardiomyopathy. However, the functional significance of STC1 is unknown. The objective of this study was to determine the effects of STC1 on TNF-␣-induced monolayer permeability of human coronary artery endothelial cells (HCAECs). Methods and Results-Cells were pretreated with STC1 for 30 minutes followed by treatment with TNF-␣ (2 ng/mL) for 24 hours. Monolayer permeability was studied using a transwell system. STC1 pretreatment significantly blocked TNF-␣-induced monolayer permeability in a concentration-and time-dependent manner. STC1 effectively blocked TNF-␣-induced downregulation of endothelial tight junction proteins zonula occluden-1 and claudin-1 at both mRNA and protein levels. STC1 also significantly decreased TNF-␣-induced superoxide anion production. The inhibitory effect of STC1 was specific to TNF-␣, as it failed to inhibit VEGF-induced endothelial permeability. Key Words: stanniocalcin-1 Ⅲ TNF-␣ Ⅲ endothelial cell Ⅲ permeability Ⅲ superoxide anion S tanniocalcin 1 (STC1) is a 25-kDa disulfide-linked homodimeric glycoprotein, which was originally identified as a secretory hormone of the corpuscles of Stannius, an endocrine gland unique to bony fish. 1 The mammalian homolog of STC1 has been found in many species including humans, rats, and mice. 2,3 Human STC1 is encoded by a single copy gene located on chromosome 8p11.2-p21 and comprises 4 exons that encode 247 amino acids with 11 cysteine residues. 2,3 Human and mouse STC1 proteins have 98% amino acid identity and share 73% overall sequence homology to fish STC. 2 Unlike the localized expression of STC1 in fish, mammalian STC1 is not detected in the blood and is expressed in many organs including the kidney, intestine, heart, thyroid, lung, placenta, brain, and bone, 4,5 suggesting a paracrine rather than an endocrine role for STC1 in mammals. The primary function of STC in fish is to prevent hypercalcemia 6 by inhibiting calcium influx through the gills and gut and stimulating phosphate reabsorption by the kidneys. 7 Similarly, in rodents, STC1 reduces the intestinal uptake of calcium while enhancing that of phosphate. 8 Furthermore, this gene seems to play diverse roles in numerous developmental, physiological, and pathological processes including cancer, pregnancy, lactation, angiogenesis, organogenesis, cerebral ischemia, and hypertonic stress. 9 Studies also indicate that STC1 modulates inflammation. For example, STC1 inhibited chemotaxis of mouse macrophages and human monoblasts in response to monocyte chemotactic protein-1 (MCP-1) and stromal cell-derived factor-1 alpha (SDF1-␣) 10 and decreased transmigration of macrophages and T-lymphocytes across quiescent or interleukin (IL)-1 beta (IL-1␤)-activated human endothelial cells. 11 Despite the growing body of knowledge about STC1, little is known about its effects on the vascular system and how it might affect endothelial barrier function during inflammation.The endothelial barrier i...

Anti-Inflammatory and Renal Protective Actions of Stanniocalcin-1 in a Model of Anti-Glomerular Basement Membrane Glomerulonephritis

“…25 It maintains the expression of tight junction proteins in a tumor necrosis factor (TNF)-␣-treated endothelial monolayer and blocks TNF-␣-induced increase in endothelial permeability. 26 Consistent with these data, we have shown STC1 attenuates transendothelial migration of macrophages and T cells. 25 We hypothesized that through suppression of macrophage function and inhibition of transendothelial migration of leukocytes, STC1 may provide potent anti-inflammatory action.…”

STC1 Expression By Cancer-Associated Fibroblasts Drives Metastasis of Colorectal Cancer

“…However, this issue should be revisited by expanded analyses of various subsets of additional tumor stromal cells, such as fibroblasts, pericytes, and neutrophils. These future analyses should also consider recent studies, which have implicated STC1, in noncancer models, as a regulator of inflammation, macrophage mobility, and vascular permeability (39)(40)(41)(42). Interestingly, earlier studies have also shown that hypoxia, a prometastatic stimuli, also leads to the upregulation of STC1 (43).…”

Anti-inflammatory functions of purpurogallin in LPS-activated human endothelial cells

“…Noting that purpurogallin inhibited expression of VCAM-1, ICAM-1 and E-selectin which mediated the monocyte firm adhesion and transendothelial migration and it also inhibited monocytes adhesion toward endothelial cells and migration across endothelial cells, we conclude that the inhibitory functions of purpurogallin in the function of key molecules in the multistep recruitment cascade presents promising strategies for therapeutic intervention in inflammatory disorders. Evidence suggests that pro-inflammatory cytokine TNF-α and NF-κB are involved in various signal transduction pathways of the expression of CAMs, mediation of adhesion, migration and endothelial permeability (21)(22)(23). Therefore, in this study we further tested the effects of purpurogallin on the production of pro-inflammatory cytokine TNF-α and NF-κB to gain further insight into the underlying mechanism of inhibitory effects of purpurogallin on the inhibition of adhesion molecules and endothelial permeability.…”

“…It is well known that activation of NF-κB is necessary for the pro-inflammatory responses and the two most important factors that provide inflammatory signals to endothelial cells are NF-κB and pro-inflammatory cytokine TNF-α (21)(22)(23). Thus, it was tested determine whether pretreatment of purpurogallin could inhibit LPS-mediated NF-κB activation and TNF-α production in HUVECs, and data showed that the levels of pro-inflammatory cytokine TNF-α and activation of NF-κB were increased by LPS and this increase was significantly decreased by purpurogallin (Fig.…”