García-Milian, Rolando

Alcohol-associated liver disease (ALD) is a growing global health concern, with alcohol-associated hepatitis (AH) leading to the highest morbidity and mortality. Available therapies are limited and often inadequate. Platelets contribute in a variety of ways to liver disease pathogenesis, but their role in AH remains largely unexplored. In this study, we addressed the hypothesis that platelets contribute to pathological inflammation in AH. Using patient samples and a multiomics approach, we found that platelets undergo proinflammatory transcriptomic and proteomic changes in AH, with 2 alarmins, S100A8 and S100A9, being among the top upregulated genes/proteins. Additionally, the abundance of platelet-derived microparticles containing S100A8 and S100A9 in AH patient plasma was increased and correlated with disease severity (assessed by model for end-stage liver disease sodium [MELD-Na]) and endotheliopathy (assessed by ICAM1, CXCL8, and vWF). We mechanistically linked S100A9 with endotheliopathy via crosstalk between primary human liver sinusoidal endothelial cells and primary human monocytes. We also demonstrated that IL-6 upregulates S100A9 in megakaryocytic cells in a JAK/STAT-dependent manner, modeling changes occurring in the bone marrow in patients with AH. Our studies establish proinflammatory platelets as important contributors to AH pathology. Moreover, antiplatelet agents — or, more specifically, S100A9 targeted drugs — are potential therapeutic strategies in AH.

Abstract Pancreatic ductal adenocarcinoma (PDAC) is a devastating cancer with an increasing incidence and extremely dismal prognosis. Discovery and mechanistic understanding of the genetic and epigenetic drivers of PDAC is therefore of critical importance. Here, we uncover serine protease inhibitor Kazal type 1 (SPINK1) as a putative determinant of clinical progression and demonstrate that it can have a non-canonical function as a regulator of epigenomic states of PDAC cells and associated extensive changes in gene expression. We show that SPINK1 expression, which varies in PDAC, is associated with key aggressive phenotypic cancer states and is correlated with the expression of stemness markers both in vitro and in patient samples. Mechanistically, our results strongly suggest that SPINK1 acts through a new signaling axis, by interacting with COL18A1 in the Golgi apparatus, promoting endostatin release and eventually inducing extensive histone H3 modifications. These results reveal a new function of SPINK1 in PDAC and suggest a potential therapeutic route to combat PDAC aggressiveness by targeting the SPINK1-COL18A1-endostatin signaling.