Cholangiocarcinoma, also known as bile duct cancer, is the second most common primary hepatic carcinoma with a median survival of less than 2 years. The molecular mechanisms underlying the development of this disease are not clear. To survey activated tyrosine kinases signaling in cholangiocarcinoma, we employed immunoaffinity profiling coupled to mass spectrometry and identified DDR1, EPHA2, EGFR, and ROS tyrosine kinases, along with over 1,000 tyrosine phosphorylation sites from about 750 different proteins in primary cholangiocarcinoma patients. Furthermore, we confirmed the presence of ROS kinase fusions in 8.7% (2 out of 23) of cholangiocarcinoma patients. Expression of the ROS fusions in 3T3 cells confers transforming ability both in vitro and in vivo, and is responsive to its kinase inhibitor. Our data demonstrate that ROS kinase is a promising candidate for a therapeutic target and for a diagnostic molecular marker in cholangiocarcinoma. The identification of ROS tyrosine kinase fusions in cholangiocarcinoma, along with the presence of other ROS kinase fusions in lung cancer and glioblastoma, suggests that a more broadly based screen for activated ROS kinase in cancer is warranted.

Our results suggest that a novel TLR2/TLR4 heterodimer induced by Hb initiates inflammatory injury in ICH. Interfering with the assembly of the TLR2/TLR4 heterodimer may be a novel target for developing effective treatment of ICH.

Intracerebral hemorrhage (ICH) is a common type of fatal stroke, accounting for about 15% to 20% of all strokes. Hemorrhagic strokes are associated with high mortality and morbidity, and increasing evidence shows that innate immune responses and inflammatory injury play a critical role in ICH-induced neurological deficits. However, the signaling pathways involved in ICH-induced inflammatory responses remain elusive. Toll-like receptor 4 (TLR4) belongs to a large family of pattern recognition receptors that play a key role in innate immunity and inflammatory responses. In this review, we summarize recent findings concerning the involvement of TLR4 signaling in ICH-induced inflammation and brain injury. We discuss the key mechanisms associated with TLR4 signaling in ICH and explore the potential for therapeutic intervention by targeting TLR4 signaling.

BaCKgRoUND aND aIMS: Itaconate, a metabolite of the tricarboxylic acid cycle, plays anti-inflammatory roles in macrophages during endotoxemia. The mechanisms underlying its anti-inflammatory roles have been shown to be mediated by the modulation of oxidative stress, an important mechanism of hepatic ischemia-reperfusion (I/R) injury. However, the role of itaconate in liver I/R injury is unknown. appRoaCH aND ReSUltS: We found that deletion of immune-responsive gene 1 (IRG1), encoding for the enzyme producing itaconate, exacerbated liver injury and systemic inflammation. Furthermore, bone marrow adoptive transfer experiments indicated that deletion of IRG1 in both hematopoietic and nonhematopoietic compartments contributes to the protection mediated by IRG1 after I/R. Interestingly, the expression of IRG1 was up-regulated in hepatocytes after I/R and hypoxia/reoxygenation-induced oxidative stress. Modulation of the IRG1 expression levels in hepatocytes regulated hepatocyte cell death. Importantly, addition of 4-octyl itaconate significantly improved liver injury and hepatocyte cell death after I/R. Furthermore, our data indicated that nuclear factor erythroid 2-related factor 2 (Nrf2) is required for the protective effect of IRG1 on mouse and human hepatocytes against oxidative stress-induced injury. Our studies document the important role of IRG1 in the acute setting of sterile injury induced by I/R. Specifically, we provide evidence that the IRG1/itaconate pathway activates Nrf2-mediated antioxidative response in hepatocytes to protect liver from I/R injury. CoNClUSIoNS: Our data expand on the importance of IRG1/itaconate in nonimmune cells and identify itaconate as a potential therapeutic strategy for this unfavorable postsurgical complication.