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Overdose of acetaminophen (APAP) is the major cause of acute liver failure in the western world. We report a novel signaling interaction between hepatocyte nuclear factor 4 alpha (HNF4α) cMyc and nuclear factor erythroid 2–related factor 2 (Nrf2) during liver injury and regeneration after APAP overdose. APAP-induced liver injury and regeneration were studied in male C57BL/6J (WT) mice, hepatocyte-specific HNF4α knockout mice (HNF4α-KO), and HNF4α-cMyc double knockout mice (DKO). C57BL/6J mice treated with 300 mg/kg maintained nuclear HNF4α expression and exhibited liver regeneration, resulting in recovery. However, treatment with 600-mg/kg APAP, where liver regeneration was inhibited and recovery was delayed, showed a rapid decline in HNF4α expression. HNF4α-KO mice developed significantly higher liver injury due to delayed glutathione recovery after APAP overdose. HNF4α-KO mice also exhibited significant induction of cMyc, and the deletion of cMyc in HNF4α-KO mice (DKO mice) reduced the APAP-induced liver injury. The DKO mice had significantly faster glutathione replenishment due to rapid induction in Gclc and Gclm genes. Coimmunoprecipitation and ChIP analyses revealed that HNF4α interacts with Nrf2 and affects its DNA binding. Furthermore, DKO mice showed significantly faster initiation of cell proliferation resulting in rapid liver regeneration and recovery. These data show that HNF4α interacts with Nrf2 and promotes glutathione replenishment aiding in recovery from APAP-induced liver injury, a process inhibited by cMyc. These studies indicate that maintaining the HNF4α function is critical for regeneration and recovery after APAP overdose.

Chronic ethanol overconsumption promotes alcohol-associated liver disease (ALD), characterized by hepatocyte injury, inflammation, hepatic stellate cell (HSC) activation, and fibrosis. Hyaluronan (HA) concentration is greater in livers and blood from advanced ALD patients than patients with advanced non-ALD. In the liver, HSCs are the major HA producers. The relationship between ethanol, HA, and HSC activation is incompletely understood. Thus, here, we tested the hypothesis that ethanol enhances HSC activation in a HA-dependent manner. Liver tissue microarrays (TMAs) containing steatotic livers from donors with or without a history of alcohol consumption were used to measure HA and collagen content. Mice were fed a moderate (2%, v/v) ethanol-containing diet or pair-fed control diet for 2 days, after which they were given a single carbon tetrachloride (CCl4) injection. To inhibit HA synthesis, we provided 4-methylumbelliferone (4MU) daily. We used LX2 cells, a human HSC cell line, to determine the impact ethanol had on LPS responses, with or without concurrent 4MU exposure. CCl4 induced liver injury, but it did not differ between ethanol or control diet fed mice with or without 4MU treatment. Ethanol feeding enhanced CCl4-induced hepatic HA content, which was paralleled by HA synthase (Has)2 transcript abundance; 4MU treatment normalized both. Consistently, HSC activation, assessed by measuring αSMA mRNA and protein, was induced by CCl4 exposure, enhanced by ethanol feeding, and normalized by 4MU. Hepatic transcripts, but not protein, for Ccl2 were enhanced by ethanol feeding and normalized by 4MU exposure. Finally, ethanol-exposed LX2 cells made more LPS-stimulated CCL2 mRNA and protein than cells not exposed to ethanol; 4MU prevented this. These data show that ethanol augments HSC activation through HA synthesis and enhances hepatic profibrogenic features. Therefore, targeting HSC HA production could potentially attenuate liver disease in ALD patients.

The ever-changing nature of cancer poses the most difficult challenge oncologists face today. Cancer’s remarkable adaptability has inspired many to work toward understanding the evolutionary dynamics that underlie this disease in hopes of learning new ways to fight it. Eco-evolutionary dynamics of a tumor are not accounted for in most standard treatment regimens, but exploiting them would help us combat treatment-resistant effectively. Here, we outline several notable efforts to exploit these dynamics and circumvent drug resistance in cancer.

Endometrial cancer (EC) is the most common type of gynecologic malignancy in the United States, with over 66, 200 new cases expected in 2023. The number of mortalities per year now approximate that of ovarian cancer. Despite our ability to identify different biologic clusters of EC, we have yet to understand the functional impact of key genomic alterations associated with discrepant prognoses and exploit this knowledge for therapeutic benefit. Given this, we set out to determine how alterations in p53 signaling, as conferred my TP53 mutations, impact radiotherapy response in EC. We also explored if manipulation of this signaling pathway could be utilized as a radio-sensitization strategy in EC. Our work demonstrates that p53 signaling plays a significant role in radiotherapy response for EC and that leveraging this genomic data may allow us to exploit this pathway as a viable radiotherapeutic target in a significant number of EC cases.

The unique aspects of brain mitochondria composition and function are incompletely understood, and new approaches are required to understand their relationship. We addressed this challenge through a dual-process isolation procedure that yields both semipure brain mitochondria suitable for functional studies but not protein localization and ultrapure brain mitochondria that are suitable for determining protein localization but functionally compromised. We observed that contrary to the published literature, N-methyl-D-aspartate receptor, ryanodine receptor 1, glyceraldehyde 3-phosphate dehydrogenase, monocarboxylate transporter 1, excitatory amino acid transporter 1, and the L-type calcium channel Cav1.2α1 subunit are absent from brain mitochondria. Utilization of this dual-process brain mitochondria isolation technique will foster clarity on mechanisms of brain health and disease.