Pancreatic triglyceride lipase mediates lipotoxic systemic inflammation
Cristiane de Oliveira, … , Mark E. Lowe, Vijay P. Singh
Cristiane de Oliveira, … , Mark E. Lowe, Vijay P. Singh
Published January 9, 2020
Citation Information: J Clin Invest. 2020;130(4):1931-1947. https://doi.org/10.1172/JCI132767.
View: Text | PDF
Research Article Gastroenterology Inflammation

Pancreatic triglyceride lipase mediates lipotoxic systemic inflammation

Abstract

Visceral adipose tissue plays a critical role in numerous diseases. Although imaging studies often show adipose involvement in abdominal diseases, their outcomes may vary from being a mild self-limited illness to one with systemic inflammation and organ failure. We therefore compared the pattern of visceral adipose injury during acute pancreatitis and acute diverticulitis to determine its role in organ failure. Acute pancreatitis–associated adipose tissue had ongoing lipolysis in the absence of adipocyte triglyceride lipase (ATGL). Pancreatic lipase injected into mouse visceral adipose tissue hydrolyzed adipose triglyceride and generated excess nonesterified fatty acids (NEFAs), which caused organ failure in the absence of acute pancreatitis. Pancreatic triglyceride lipase (PNLIP) increased in adipose tissue during pancreatitis and entered adipocytes by multiple mechanisms, hydrolyzing adipose triglyceride and generating excess NEFAs. During pancreatitis, obese PNLIP-knockout mice, unlike obese adipocyte-specific ATGL knockouts, had lower visceral adipose tissue lipolysis, milder inflammation, less severe organ failure, and improved survival. PNLIP-knockout mice, unlike ATGL knockouts, were protected from adipocyte-induced pancreatic acinar injury without affecting NEFA signaling or acute pancreatitis induction. Therefore, during pancreatitis, unlike diverticulitis, PNLIP leaking into visceral adipose tissue can cause excessive visceral adipose tissue lipolysis independently of adipocyte-autonomous ATGL, and thereby worsen organ failure.

Authors

Cristiane de Oliveira, Biswajit Khatua, Pawan Noel, Sergiy Kostenko, Arup Bag, Bijinu Balakrishnan, Krutika S. Patel, Andre A. Guerra, Melissa N. Martinez, Shubham Trivedi, Ann McCullough, Dora M. Lam-Himlin, Sarah Navina, Douglas O. Faigel, Norio Fukami, Rahul Pannala, Anna Evans Phillips, Georgios I. Papachristou, Erin E. Kershaw, Mark E. Lowe, Vijay P. Singh

×

Figure 3

Relevance of oleic acid to systemic injury in mice and during human severe pancreatitis.

Options: View larger image (or click on image) Download as PowerPoint
Relevance of oleic acid to systemic injury in mice and during human seve...
(A–E) Blood levels of serum oleic acid (OA) (A), IL-6 (B), MCP-1 (C), TNF-α (D), and BUN (E) in the control (Con) and OA-treated groups of mice at the time of euthanasia. (F) Carotid pulse distention and (G) rectal temperatures prior to euthanasia of these mice. (H) Representative images from lung histologic sections stained by TUNEL (green) with nuclei stained red. Arrows point to the positive-staining nuclei. Scale bars: 250 μm. There were 8 mice in each group. (I) Serum OA levels in the control patient group (Con Pts.) and severe acute pancreatitis (SAP) patients from the PROOF cohort. *P < 0.05 by Mann-Whitney test. Error bars represent SD.