Intestinal Epithelia and Myeloid Immune Cells Shape Colitis Severity and Colorectal Carcinogenesis via High-mobility Group Box Protein 1.

Background: High-mobility group box protein 1 [HMGB1] is a ubiquitous nucleoprotein with immune-regulatory properties following cellular secretion or release in sterile and in infectious inflammation. Stool and serum HMGB1 levels correlate with colitis severity and colorectal cancer [CRC] progression, yet recent reports indicate that HMGB1 mainly operates as an intracellular determinant of enterocyte fate during colitis, and investigations into the roles of HMGB1 in CRC are lacking.

Methods: Using mice with conditional HMGB1-knockout in enterocytes [Hmgb1ΔIEC] and myeloid cells [Hmgb1ΔLysM], respectively, we explored functions of HMGB1 in pathogenetically diverse contexts of colitis and colitis-associated CRC.

High risk of complications and acute-on-chronic liver failure in cirrhosis patients with acute pancreatitis.

Background & Aims: Acute pancreatitis (AP) is a frequent indication for hospitalization and may present with varying degrees of severity. AP often coincides with hepatic disease, yet the impact of liver cirrhosis (LC) on the course of AP is uncertain, and early identification of patients at risk for complications remains challenging. We aimed to assess the impact of LC on the development of pancreatic and extra-pancreatic complications of AP, and to identify predictors of adverse outcomes in cirrhotic patients.

Leukocyte-Derived High-Mobility Group Box 1 Governs Hepatic Immune Responses to Listeria monocytogenes.

High-mobility group box 1 (HMGB1) is a nucleoprotein with proinflammatory functions following cellular release during tissue damage. Moreover, antibody-mediated HMGB1 neutralization alleviates lipopolysaccharide (LPS)-induced shock, suggesting a role for HMGB1 as a superordinate therapeutic target for inflammatory and infectious diseases. Recent genetic studies have indicated cell-intrinsic functions of HMGB1 in phagocytes as critical elements of immune responses to infections, yet the role of extracellular HMGB1 signaling in this context remains elusive.

Epithelial HMGB1 Delays Skin Wound Healing and Drives Tumor Initiation by Priming Neutrophils for NET Formation.

Regenerative responses predispose tissues to tumor formation by largely unknown mechanisms. High-mobility group box 1 (HMGB1) is a danger-associated molecular pattern contributing to inflammatory pathologies. We show that HMGB1 derived from keratinocytes, but not myeloid cells, delays cutaneous wound healing and drives tumor formation.

Stabilisation of acute-on-chronic liver failure patients before liver transplantation predicts post-transplant survival.

Background: Acute-on-chronic liver failure (ACLF) is a severe complication of liver cirrhosis associated with excess short-term mortality rates. Orthotopic liver transplantation (OLT) is a potentially life-saving therapeutic modality for acute-on-chronic liver failure patients, but selection of transplant candidates with an acceptable post-transplant outcome is difficult.

Aim: To assess the risk of liver transplantation in patients with ACLF, and to determine parameters that predict post-transplant survival in this patient cohort.

HMGB1 links chronic liver injury to progenitor responses and hepatocarcinogenesis.

Cell death is a key driver of disease progression and carcinogenesis in chronic liver disease (CLD), highlighted by the well-established clinical correlation between hepatocellular death and risk for the development of cirrhosis and hepatocellular carcinoma (HCC). Moreover, hepatocellular death is sufficient to trigger fibrosis and HCC in mice. However, the pathways through which cell death drives CLD progression remain elusive.

Damage-associated molecular patterns in cancer: a double-edged sword.

Damage-associated molecular patterns (DAMPs) are released in response to cell death and stress, and are potent triggers of sterile inflammation. Recent evidence suggests that DAMPs may also have a key role in the development of cancer, as well as in the host response to cytotoxic anti-tumor therapy. As such, DAMPs may exert protective functions by alerting the immune system to the presence of dying tumor cells, thereby triggering immunogenic tumor cell death.

Criteria Used in Clinical Practice to Guide Immunosuppressive Treatment in Patients with Primary Sclerosing Cholangitis.

Background & Aims: Current guidelines recommend immunosuppressive treatment (IT) in patients with primary sclerosing cholangitis (PSC) and elevated aminotransferase levels more than five times the upper limit of normal and elevated serum IgG-levels above twice the upper limit of normal. Since there is no evidence to support this recommendation, we aimed to assess the criteria that guided clinicians in clinical practice to initiate IT in patients with previously diagnosed PSC.

Methods: This is a retrospective analysis of 196 PSC patients from seven German hepatology centers, of whom 36 patients had received IT solely for their liver disease during the course of PSC.

Comment on: HMGB1-dependent and -independent autophagy.

HMGB1 (high mobility group box 1), a ubiquitously expressed DNA-binding nucleoprotein, has not only been attributed with important functions in the regulation of gene expression but is thought to function as an important damage-associated molecular pattern in the extracellular space. Recently, conditional Hmgb1 deletion strategies have been employed to overcome the perinatal mortality of global Hmgb1 deletion and to understand HMGB1 functions under disease conditions. From these studies, it has become evident that HMGB1 is not required for normal organ function.

The HMGB1/RAGE axis triggers neutrophil-mediated injury amplification following necrosis.

In contrast to microbially triggered inflammation, mechanisms promoting sterile inflammation remain poorly understood. Damage-associated molecular patterns (DAMPs) are considered key inducers of sterile inflammation following cell death, but the relative contribution of specific DAMPs, including high-mobility group box 1 (HMGB1), is ill defined. Due to the postnatal lethality of Hmgb1-knockout mice, the role of HMGB1 in sterile inflammation and disease processes in vivo remains controversial.

Prenatal acetaminophen induces liver toxicity in dams, reduces fetal liver stem cells, and increases airway inflammation in adult offspring.

Background & Aims: During pregnancy, acetaminophen is one of the very few medications recommended by physicians to treat fever or pain. Recent insights from epidemiological studies suggest an association between prenatal acetaminophen medication and an increased risk for development of asthma in children later in life. The underlying pathogenesis of such association is still unknown.

Cardioprotective effects of osteopontin-1 during development of murine ischemic cardiomyopathy.

Repetitive brief ischemia and reperfusion (I/R) is associated with ventricular dysfunction in pathogenesis of murine ischemic cardiomyopathy and human hibernating myocardium. We investigated the role of matricellular protein osteopontin-1 (OPN) in murine model of repetitive I/R. One 15-min LAD-occlusion followed by reperfusion was performed daily over 3, 5, and 7 consecutive days in C57/Bl6 wildtype- (WT-) and OPN(-/-)-mice (n = 8/group).

Regulation of wound healing and organ fibrosis by toll-like receptors.

Chronic injury often triggers maladaptive wound healing responses leading to the development of tissue fibrosis and subsequent organ malfunction. Inflammation is a key component of the wound healing process and promotes the development of organ fibrosis. Here, we review the contribution of Toll-like receptors (TLRs) to wound healing with a particular focus on their role in liver, lung, kidney, skin and myocardial fibrosis.