Chronic pancreatitis (CP) is a progressive inflammatory disorder of the pancreas that is accompanied by severe abdominal pain. The most common cause is long-term alcohol abuse. CP is characterized by the sustained activation of pancreatic stellate cells (PSCs). During pancreatic injury, quiescent PSCs transform into activated PSCs (aPSCs) and lead to excessive extracellular matrix to comprise fibrous tissues. Therefore, the overarching goal is to eradicate aPSCs, an originator of CP, to prevent, stop and/or reverse the development of CP and its complications, pain. To date, there are no approved noninvasive therapies. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a death ligand that selectively induces apoptosis after binding to its death receptors (DRs). In our preliminary study, we discovered that primary human PSCs upregulate DR5 (>10-fold) during activation and can be targeted for TRAIL-induced apoptosis. Recombinant TRAIL has an intrinsically short half-life. We developed a bioengineered, PEGylated TRAIL (PEG-TRAIL) with extended half-life and superior pharmacodynamic profiles in animal models. We confirmed that primary human aPSCs, but not quiescent PSCs, become highly sensitive to PEG-TRAIL-induced apoptosis. Particularly, we demonstrated systemically administered PEG-TRAIL reduces collagen deposition, inflammation and pain in alcohol-induced CP rats. The goal of this application is to explore the role of DRs and TRAIL signaling in PSC activation, fibrogenesis and pain in primary human PSCs and pancreatic tissues from patients with CP as well as in alcohol-induced CP models. In addition, molecular imaging technology will be developed to track and monitor fibrogenesis in the pancreas by imaging aPSCs. To realize this goal, we will explore TRAIL signaling molecules and fibrosis biomarkers in primary human PSCs, PSCs and acinar cells isolated from alcohol-induced CP rat models at various activation stages, and pancreatic tissues from patients with CP (Aim 1). Next, we will evaluate the antifibrotic and anti-pain effects of PEG-TRAIL in alcohol-induced CP while noninvasively imaging PSC activation in vivo (Aim 2). Noninvasive SPECT imaging agents will be developed to validate the role of TRAIL signaling in vivo and importantly monitor antifibrotic efficacy of PEG-TRAIL in real- time. Finally, we will clarify the role of TRAIL signaling in CP by analyzing tissues and blood samples from Aim 2 to determine the feasibility of targeting aPSCs through DRs as an antifibrotic and anti-pain therapy (Aim 3). After completion of these aims, we would develop a more in-depth application to understand the role of TRAIL signaling in PSCs in pancreatic fibrogenesis and CP-associated pain as well as determine if systemically administered TRAIL is an effective treatment in various experimental CP animal models. Our proposed proof-of-concept could signify a new direction in developing novel antifibrotic and anti-pain therapies targeting CP and other fibrotic diseases.
To date, there are no approved agents treating pancreatic fibrosis and only highly invasive surgical methods to address pain from chronic pancreatitis (CP). Activated pancreatic stellate cells (PSCs) are an originator of CP and its complications. We propose a new way of targeting and eradicating activated PSCs by studying the unexplored role of death receptors and TRAIL signaling in PSCs during fibrogenesis as a result of CP.
