CR6 interacting factor 1 deficiency promotes endothelial inflammation by SIRT1 downregulation

Abstract

AimsCR6 interacting factor 1 (CRIF1) deficiency impairs mitochondrial oxidative phosphorylation complexes, contributing to increased mitochondrial and cellular reactive oxygen species (ROS) production. CRIF1 downregulation has also been revealed to decrease sirtuin 1 (SIRT1) expression and impair vascular function. Inhibition of SIRT1 disturbs oxidative energy metabolism and stimulates nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)-induced inflammation. Therefore, we hypothesized that both CRIF1 deficiency-induced mitochondrial ROS production and SIRT1 reduction play stimulatory roles in vascular inflammation.Methods and resultsPlasma levels and mRNA expression of proinflammatory cytokines (tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6) were markedly elevated in endothelium-specific CRIF1-knockout mice and CRIF1-silenced endothelial cells, respectively. Moreover, CRIF1 deficiency-induced vascular adhesion molecule-1 (VCAM-1) expression was consistently attenuated by the antioxidant N-acetyl-cysteine and NF-κB inhibitor (BAY11). We next showed that siRNA-mediated CRIF1 downregulation markedly activated NF-κB. SIRT1 overexpression not only rescued CRIF1 deficiency-induced NF-κB activation but also decreased inflammatory cytokines (TNF-α, IL-1β, and IL-6) and VCAM-1 expression levels in endothelial cells.ConclusionsThese results strongly suggest that CRIF1 deficiency promotes endothelial cell inflammation by increasing VCAM-1 expression, elevating inflammatory cytokines levels, and activating the transcription factor NF-κB, all of which were inhibited by SIRT1 overexpression.

SIRT1 Activation Attenuates the Cardiac Dysfunction Induced by Endothelial Cell-Specific Deletion of CRIF1

“…Previously, we reported that SIRT1 mediates CRIF1 deletion-induced endothelial inflammation by activating the transcription factor NFκB and inflammatory mediators (TNF-α, IL-1β, IL-6, and VCAM-1) in human umbilical vein endothelial cells [ 16 ]. To elucidate the effect of SRT1720 on inflammation in cardiac tissues, we evaluated NFκB activation and the production of inflammatory mediators (TNF-α, IL-1β, IL-6, and VCAM-1) in each group.…”

“…Since the number of endothelial cells is nearly three-fold that of cardiomyocytes, and as endothelial cells control cell-to-cell communication and homeostasis, which are critical for normal cardiac function, we questioned whether impaired endothelial cells caused by mitochondrial OXPHOS dysfunction also affect cardiac function. Previously, we showed that downregulation of CRIF1 triggered endothelial dysfunction and inflammation caused by defective mitochondrial oxidative function in human umbilical vein endothelial cells [ 16 , 17 ]. Sirtuin 1 (SIRT1), a nicotinamide adenine dinucleotide-dependent deacetylase, ameliorates vascular endothelial dysfunction by mediating endothelial nitric oxide synthase (eNOS)/nitric oxide (NO) and scavenging oxidative stress levels, which are reportedly related to CRIF1 deletion-induced endothelial dysfunction [ 17 ].…”

Far-Infrared-Emitting Sericite Board Upregulates Endothelial Nitric Oxide Synthase Activity through Increasing Biosynthesis of Tetrahydrobiopterin in Endothelial Cells

“…The following antibodies were used: anti-Akt (Cell Signaling Technology, Danvers, MA, USA), antiphospho Akt (Santa Cruz Biotechnology, Santa Cruz, CA, USA), anti- β -actin (Sigma-Aldrich, St. Louis, MO, USA), anti-eNOS (Santa Cruz Biotechnology), antiphospho eNOS (S1177) (Cell Signaling Technology), antivascular cell adhesion molecule (VCAM)-1 (Santa Cruz Biotechnology), anti-intercellular adhesion molecule (ICAM)-1 (Santa Cruz Biotechnology), anti-GCH1 (Santa Cruz Biotechnology), anti-6-pyruvoyl tetrahydrobiopterin synthase (PTS) (Santa Cruz Biotechnology), antisepiapterin reductase (SPR) (Santa Cruz Biotechnology), and anti-DHFR (Santa Cruz Biotechnology). Immunoblotting was performed as previously described [12].…”

“…HUVECs and rat lung endothelial cells were used to measure the biopterin content. To harvest rat lung endothelial cells, we followed methods described in a previous paper [12, 13]. Cells were dissolved in cell lysis buffer (50 mM Tris-HCl, pH 7.5, 150 mM NaCl, 1 mM EDTA, and 1 mM DTT) and centrifuged at 13000 g for 20 min.…”

“…Total RNA from HUVECs or lung endothelial cells were isolated using a protocol described previously. [12] The primers used for human VCAM-1 and ICAM-1 were as follows: sense VCAM-1, 5′-AAT GGG AAT CTA CAG CAC CTT T-3′ and antisense VCAM-1, 5′-ATA TCC GTA TCC TCC AAA AAC T-3′; sense ICAM-1, 5′-GTG GTA GCA GCC GCA GTC-3′ and antisense ICAM-1, 5′-GGC TTG TGT GTT CGG TTT CA-3′. The primers for human glyceraldehyde 3-phosphate dehydrogenase, amplified as an internal control, were as follows: sense, 5′-CCT GCA CCA CCA ACT GCT TA-3′ and antisense, 5′-GGC CAT CCA CAG TCT TCT GAG-3′.…”