Function of connexin 43 and RhoA/LIMK2/Cofilin signaling pathway in transient changes of contraction and dilation of human umbilical arterial smooth muscle cells

Int J Biochem Cell Biol. 2022 Dec:153:106326. doi: 10.1016/j.biocel.2022.106326. Epub 2022 Oct 28.

Abstract

Background: Post-induction hypotension, a common complication after propofol-based induction regimen, is a life-threatening challenge for anesthesiologists especially when unexpected pre-induction hypertension characterized by angiotensin release and increased vascular tone was presented by the same patient. Gap junctions (GJs) composed of connexin 43 (Cx43) have been considered a key factor in regulating vascular contraction and dilation. We aimed to explore the role of Cx43-GJs during peri-induction blood pressure fluctuation and elucidate the underlying mechanisms.

Methods: Human umbilical arterial smooth muscle cells (HUASMCs) were pretreated by short-term Angiotensin Ⅱ (Ang Ⅱ) with or without subsequent propofol treatment to simulate transient contraction and dilation of vascular smooth muscle cells during anesthesia induction. F-actin polymerization, a classic indicator of HUASMCs constriction, was determined by F-actin staining assay. Both the function and expression of Cx43-GJs during transient contraction and dilation of HUASMCs, and their potential regulation of downstream Ca2+/RhoA/LIMK2/Cofilin signaling pathway were explored via different targeting inhibitors and siRNAs.

Results: Ang Ⅱ pretreatment significantly induced F-actin polymerization that indicate cell contraction, accompanied by enhanced GJs function on HUASMCs. With the inhibition of Cx43 GJs by the specific inhibitor, Gap26, and Cx43-siRNA, Ang Ⅱ-induced F-actin polymerization was reversed accompanied with the decrease of intracellular Ca2+ mobility and the RhoA/LIMK2/Cofilin signaling pathway activity. We also noticed that propofol application could inhibit GJs function, the same as Gap26. Simultaneously, intracellular Ca2+ mobility and RhoA/LIMK2/Cofilin signaling pathway activity on HUASMCs were both downregulated, finally resulting in downstream reduction of F-actin polymerization.

Conclusion: The function of Cx43-GJs lies in the center of Ang Ⅱ-induced contraction of HUASMCs, which potentially regulates intracellular Ca2+ mobility as well as RhoA/LIMK2/Cofilin signaling pathway activity. Propofol can reverse this effect induced by Ang Ⅱ through suppressing the function of Cx43-GJs.

Keywords: Angiotensin Ⅱ; Connexin 43; Gap junction; Propofol.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actin Depolymerizing Factors / metabolism
  • Actins / metabolism
  • Angiotensin II / metabolism
  • Angiotensin II / pharmacology
  • Connexin 43* / genetics
  • Connexin 43* / metabolism
  • Dilatation
  • Humans
  • Lim Kinases / metabolism
  • Myocytes, Smooth Muscle / metabolism
  • Propofol* / metabolism
  • Propofol* / pharmacology
  • Signal Transduction
  • rhoA GTP-Binding Protein / metabolism

Substances

  • Connexin 43
  • Actin Depolymerizing Factors
  • Actins
  • Propofol
  • Angiotensin II
  • RHOA protein, human
  • rhoA GTP-Binding Protein
  • LIMK2 protein, human
  • Lim Kinases