Propofol attenuated liver transplantation-induced acute lung injury via connexin43 gap junction inhibition

Abstract

BackgroundPostoperative acute lung injury (ALI) is a severe complication after liver transplantation, which influences patient survival rate obviously. However, its mechanisms are unclear and effective therapies are still lacking. The current study focused on effects of propofol on liver transplantation-induced ALI and whether its underlying mechanism was relative with connexin43 (Cx43) alternation. The authors postulated that endotoxin induced enhancement of Cx43 gap junction (GJ) plays a critical role in mediating post liver transplantation ALI and that pretreatment with the anesthetic propofol, known to inhibit gap junction, can confer effective protection.MethodsMale Sprague–Dawley rats underwent autologous orthotopic liver transplantation (AOLT) in the absence or presence of treatments with the selective Cx43 inhibitor, enanthol (0.1 mg/kg) and propofol (50 mg/kg), a commonly used anesthetic in clinical anesthesia. In vitro study, BEAS-2B cells, a kind of lung epithelial cell line expressing Cx43, exposed to lipopolysaccharide (LPS), which mainly contributed to ALI. Function of Cx43 GJ was regulated by Cx43 specific inhibitors, gap26 (300 μM) or enhancer, retinoic acid (10 μM) and two specific siRNAs.ResultsCompared with the sham group, AOLT results in ALI obviously with plasma endotoxin increase. Cx43 inhibition decreased ALI through inflammatory reaction reduction. In vitro studies, LPS-induced BEAS-2B cells damage was attenuated by Cx43 function inhibition, but amplified by enhancement. Another important finding was propofol reduced Cx43 function and protected against LPS-mediated BEAS-2B cells damage or AOLT-induced ALI, mechanisms of which were also associated with inflammatory reaction decrease.ConclusionCx43 plays a vital role in liver transplantation-induced ALI. Propofol decreased Cx43 function and protected against ALI in vivo and in vitro. This finding provide a new basis for targeted intervention of organ protection in liver transplantation, even in other kinds of operations.

Improved multiparametric scrape loading-dye transfer assay for a simultaneous high-throughput analysis of gap junctional intercellular communication, cell density and viability

“…Importantly, we demonstrated applicability of our innovative multiparametric SL-DT assay for variety of in vitro cell types such as liver cells (WB-F344), lung cells (BEAS-2B, HBE1) or testicular cells (TM4 and TM3 cells), which all are GJIC-competent cells commonly used for the assessment of GJIC in response to different chemicals [50][51][52][53][54] or physical treatments 55 . All these cell types express connexin 43 51,56,57 , which is widely expressed in many cell types (especially in the epithelial cells) and whose gap junction channels are diffusible for Lucifer Yellow fluorescent dye 58 . In addition to gap junctions formed by connexin 43, Lucifer Yellow has been reported to transfer through channels formed by a number of other connexin types, such as connexin 26, 31, 32, 37, 40, 45, 46, 47 34,[58][59][60][61][62] .…”

Dexmedetomidine Attenuates LPS-Induced Monocyte-Endothelial Adherence via Inhibiting Cx43/PKC-α/NOX2/ROS Signaling Pathway in Monocytes

“…These results demonstrated that LPS-induced monocyte-endothelial adherence increase also started from acting on the cell membrane. According to the analysis of the transmembrane structure of Cx43 protein, we noticed that its carboxyl-terminal domain could interact with some cellular signaling pathways, the most important one of which was just PKC [9,26]. This kind of interaction provided the possibility that Cx43 Figure 2: Dexmedetomidine attenuates U937-HUVEC adhesion and inhibits VAL-4 and LFA-1 expressions in U937 monocytes via downregulating the NOX2/ROS signaling pathway.…”

Dexmedetomidine Attenuates Monocyte-Endothelial Adherence via Inhibiting Connexin43 on Vascular Endothelial Cells

“…Interfering RNA (siRNA) Transfection [6]. We design two special siR-NAs (Cx43-siRNA1: GCTGGTTACTGGTGACAGA; Cx43-siRNA2: CCGCAATTACAACAAGCAA) targeting Cx43 gene and a nonspecific, control siRNA (NC; CGCGATATA GCGCATCGAT) to inhibit Cx43 expression on HUVECs.…”

“…Connexins are a large family of proteins, expressing in almost all human organs and tissues. They form channels between the neighboring cells, called gap junction, mediating intercellular movement of cytosolic signaling molecules [6]. There are three predominant connexins expressed in endothelial cells, Cx37, Cx40, and Cx43, the most important one of which is Cx43 [7].…”