The ciliary protein Spef2 stimulates acinar Ampkα/Sirt1 signaling and ameliorates acute pancreatitis and associated lung injury

Chun Zhang; Deng-Fang Guo; Gui-Fang Lv; Dai-Chang Zhang; Feng Lin; Jia-Bin Liu; Jian-Yuan Lin; De-Xian Xiao

doi:10.21037/atm-22-3118

The ciliary protein Spef2 stimulates acinar Ampkα/Sirt1 signaling and ameliorates acute pancreatitis and associated lung injury

Ann Transl Med. 2022 Jul;10(14):798. doi: 10.21037/atm-22-3118.

Authors

Chun Zhang^#¹, Deng-Fang Guo^#¹, Gui-Fang Lv¹, Dai-Chang Zhang¹, Feng Lin¹, Jia-Bin Liu¹, Jian-Yuan Lin¹, De-Xian Xiao¹

Affiliation

¹ Department of General Surgery, Mindong Hospital Affiliated to Fujian Medical University, Fu'an, China.

^# Contributed equally.

Abstract

Background: Pancreatic acinar cells are susceptible to nuclear factor kappa B (NF-κB)-mediated inflammation and resulting cell necrosis during early acute pancreatitis. As adenosine monophosphate-activated protein kinase alpha (Ampkα)/sirtuin 1 (Sirt1) pathway activity attenuates NF-κB activity, we examined whether the Ampkα/Sirt1 axis affects the progression of acute pancreatitis and associated lung injury in vivo. Furthermore, we explored the role of the ciliary protein sperm flagellar 2 (Spef2, Kpl2) in regulating Ampkα/Sirt1 activity in vitro and in vivo.

Methods: Pancreatic injury, oxidative stress, acinar cell necrosis and apoptosis, acinar levels of Ampkα/Sirt1/NF-κB signaling activity, NF-kB-mediated inflammatory markers, and markers of associated lung injury were measured in rat models of acute pancreatitis following pharmacological Ampkα activation with A769662 or self-complementary recombinant adeno-associated virus serotype 6 (scAAV6)-mediated Spef2 overexpression. Additional in vivo rescue studies involving Ampkα silencing and/or constitutively active (CA)-Sirt1 overexpression were performed in acute pancreatitis rats. In vitro immunoblotting and Ampkα activity assays were conducted in the pancreatic acinar cell line AR42J.

Results: Pharmacological Ampkα activation or Spef2 overexpression reduced acute pancreatitis severity, oxidative stress, necrosis, apoptosis, NF-kB-mediated inflammatory markers, and the degree of associated lung injury. Spef2 overexpression in AR42J cells in vitro promoted Ampkα^Thr172 phosphorylation and Ampkα activity. In vivo rescue studies revealed that Spef2's suppressive effect on acute pancreatitis and associated lung injury is mediated via the Ampkα/Sirt1 axis.

Conclusions: This study established the existence of a Spef2/Ampkα/Sirt1 axis in pancreatic acinar cells that is involved in the regulation of NF-κB-mediated acinar cell inflammation and resulting cell necrosis during acute pancreatitis.

Keywords: Acute pancreatitis; Ampkα; NF-κB; Sirt1; Spef2.