Chrm3 protects against acinar cell necrosis by stabilizing caspase-8 expression in severe acute pancreatitis mice model

JMJD3 Is Required for Acute Pancreatitis and Pancreatitis-Associated Lung Injury

Acute pancreatitis (AP) can be complicated by inflammatory disorders of remote organs, such as lung injury, in which Jumonji domain-containing protein 3 (JMJD3) plays a vital role in proinflammatory responses. Currently, we found that JMJD3 expression was upregulated in the pancreas and lung in an AP male mouse model, which was also confirmed in AP patients. Further experiments revealed that the upregulation of JMJD3 and proinflammatory effects were possibly exerted by mitochondrial DNA (mtDNA) or oxidized-mtDNA from tissue injury caused by AP. The release of mtDNA and oxidized-mtDNA contributed to the infiltration of inflammatory monocytes in lung injury through the stimulator of IFN genes (STING)/TLR9-NF-κB-JMJD3-TNF-α pathway. The inhibition of JMJD3 or utilization of Jmjd3-cKO mice significantly alleviated pulmonary inflammation induced by AP. Blocking mtDNA oxidation or knocking down the TLR9/STING pathway effectively alleviated inflammation. Therefore, inhibition of JMJD3 or STING/TLR9 pathway blockage might be a potential therapeutic strategy to treat AP and the associated lung injury.

CTRP3 ameliorates cerulein-induced severe acute pancreatitis in mice via SIRT1/NF-κB/p53 axis

Severe acute pancreatitis (SAP) is a common and life-threatening clinical acute abdominal disease. C1q/tumor necrosis factor-related protein 3 (CTRP3), a novel paralog of adiponectin, has been identified as a crucial regulator in multiple types of inflammatory disorders. However, the biological role of CTRP3 in SAP remains poorly understood. The present study aimed to characterize the role of CTRP3 in SAP and illuminate the potential mechanisms involved. In the current study, SAP mouse models were induced by seven hourly intraperitoneal injection of cerulein (50 μg/kg) and an immediate intraperitoneal injection of lipopolysaccharide (10 mg/kg) after the last cerulein administration. Histological examination and serological analysis demonstrated that SAP mouse models were successfully established. Herein, we found that CTRP3 expression was significantly decreased in the pancreatic tissues of SAP mice compared with normal control mice. Furthermore, we explored the effects of CTRP3 rescue in SAP mice and discovered that CTRP3 overexpression attenuated pathological lesions, inhibited inflammatory mediator release and repressed acinar cell apoptosis. Notably, mechanistic studies revealed that CTRP3 overexpression suppressed NF-κB p65 phosphorylation and p53 acetylation to alleviate cerulein-induced SAP in mouse models through activation of silent information regulator 1 (SIRT1), a nicotinamide adenine dinucleotide-dependent protein deacetylase. Collectively, our data indicate that CTRP3 may exert its protective effects in SAP mice via regulation of SIRT1-mediated NF-κB and p53 signaling pathways, implying a promising therapeutic strategy against SAP.

Inhibition of CHRM3 Alleviates Necrosis Via the MAPK-p38/miR-31-5p/RIP3 Axis in L-Arginine-Induced Severe Acute Pancreatitis

OBJECTIVES

Pancreatic acinar necrosis is a typical feature in the early phase of severe acute pancreatitis (SAP). Muscarinic acetylcholine receptor M3 (CHRM3) has been reported to play important roles in promoting insulin secretion and tumor cell proliferation, but its effect on necrosis remains unknown. This study revealed the important role of CHRM3 in regulating L-arginine-induced SAP and the molecular mechanisms.

METHODS

To verify the function of CHRM3, pancreatic tissues and primary acinar cells of CRISPR/Cas9-mediated Chrm3 knockout mice were used in CHRM3 knockdown experiments, and to ascertain the CHRM3 overexpression, PLV-EGFP-Chrm3 plasmids were transfected in acinar cells in vitro.

RESULTS

In L-arginine-induced SAP, CHRM3 is activated and regulates SAP through the mitogen-activated protein kinase/p38 pathway. Moreover, the expression of miR-31-5p decreased in the SAP model both in vitro and in vivo. Mir-31-5p effects the necrosis of acinar cells in SAP by upregulating the target gene RIP3, and miR-31-5p is a downstream miRNA of CHRM3.

CONCLUSIONS

Necrosis in L-arginine-induced SAP is promoted by CHRM3 through the mitogen-activated protein kinase-p38/miR-31-5p/RIP3 axis.