Novel Oridonin Analog CYD0682 Inhibits Hepatic Stellate Cell Activation via the Heat Shock Protein 90-Dependent STAT3 Pathway.

INTRODUCTION: Activated hepatic stellate cells (HSCs) are the primary effector cells in hepatic fibrosis, over depositing extracellular matrix (ECM) proteins. Our previous work found oridonin analog CYD0682 attenuates proliferation, Transforming Growth Factor ß (TGFß)-induced signaling, and ECM production in immortalized HSCs. The underlying mechanism behind these reductions is unclear. The Signal Transduction and Activator of Transcription 3 (STAT3) pathway plays a central role in HSC activation and has been found to be overexpressed in models of hepatic injury. In this study, we will examine the effect of CYD0682 on STAT3 signaling. METHODS: Immortalized human (LX-2) and rat (HSC-T6) HSC lines were treated with CYD0682 or Tanespimycin (17-AAG) with or without TGF-ß. Nuclear and cytosolic proteins were extracted. Protein expression was analyzed with Western blot. DNA binding activity was assessed with STAT3 DNA Binding ELISA. Cell viability was assessed with Alamar blue assay. RESULTS: CYD0682 treatment inhibited STAT3 phosphorylation at tyrosine 705 in a dose-dependent manner in LX-2 and HSC-T6 cells. STAT3 DNA binding activity and STAT3 regulated protein c-myc were significantly decreased by CYD0682. Notably, TGFß-induced STAT3 phosphorylation and ECM protein expression were inhibited by CYD0682. STAT3 is reported to be a Heat Shock Protein 90 (HSP90) client protein. Notably, CYD0682 attenuated the expression of endogenous STAT3 and other HSP90 client proteins FAK, IKKα, AKT and CDK9. HSP90 specific inhibitor 17-AAG suppressed endogenous and TGFß-induced STAT3 phosphorylation and ECM protein production. CONCLUSIONS: CYD0682 attenuates endogenous and TGFß-induced STAT3 activation and ECM production via an HSP90 dependent pathway in HSCs. Further study of this pathway may present new targets for therapeutic intervention in hepatic fibrosis.

A Rare Case of Erosive Esophagitis Due to Sarcina Ventriculi Infection.

Sarcina ventriculi is a Gram-positive anaerobic coccus found in soil that is a rare cause of inflammatory infections of the GI tract. This bacterium has a propensity for causing gastritis in patients with delayed gastric emptying. Of the 66 reported cases in the literature, 10 involved the esophagus. Symptoms of an esophageal infection are non-specific and may be mistaken for long-standing gastroesophageal reflux. We present a case of a 67-year-old female with chronic dysphagia and reflux diagnosed with erosive esophagitis caused by Sarcina ventriculi. Treatment strategies documented in the literature are reviewed.

PARP1 Inhibition and Effect on Burn Injury-Induced Inflammatory Response and Cardiac Function.

BACKGROUND: Burn injury induces multiple signaling pathways leading to a significant inflammatory storm that adversely affects multiple organs, including the heart. Poly (ADP-ribose) polymerase inhibitor 1 (PARP1) inhibition, with specific agents such as N-(5,6-Dihydro-6-oxo-2-phenanthridinyl)-2-acetamide (PJ34), is effective in reducing oxidative stress and cytokine expression in the heart. We hypothesized that PARP1 inhibition would reduce inflammatory signaling and protect against burn injury-induced cardiac dysfunction. STUDY DESIGN: Male Sprague-Dawley rats (8 weeks old, 300 to 350 g) were randomly assigned to sham injury (Sham), 60% total body surface area burn (24 hours post burn), or 60% total body surface area burn with intraperitoneal administration of PJ34 (20 mg/kg, 24 hours post burn + PJ34) and sacrificed 24 hours after injury. Cardiac function was determined using Vevo 2100 echocardiography. Genetic expression of 84 specific toll-like receptor-mediated signal transduction and innate immunity genes were examined using microarray to evaluate cardiac tissue. Qiagen GeneGlobe Data Analysis Center was used to analyze expression, and genetic clustering was performed using TreeView V2.0.8 software. Real-time quantitative polymerase chain reaction was used to validate identified differentially expressed genes. RESULTS: Burn injury significantly altered multiple genes in the toll-like receptor signaling, interleukin-17 signaling, tumor necrosis factor signaling, and nuclear factor-κB signaling pathways and led to significant cardiac dysfunction. PARP1 inhibition with PJ34 normalized these signaling pathways to sham levels as well as improved cardiac function to sham levels. CONCLUSIONS: PARP1 inhibition normalizes multiple inflammatory pathways that are altered after burn injury and improves cardiac dysfunction. PARP1 pathway inhibition may provide a novel methodology to normalize multiple burn injury-induced inflammatory pathways in the heart.

Cytokine Pathways in Cardiac Dysfunction following Burn Injury and Changes in Genome Expression.

In 2016, an estimated 486,000 individuals sustained burn injuries requiring medical attention. Severe burn injuries lead to a persistent, hyperinflammatory response that may last up to 2 years. The persistent release of inflammatory mediators contributes to end-organ dysfunction and changes in genome expression. Burn-induced cardiac dysfunction may lead to heart failure and changes in cardiac remodeling. Cytokines promote the inflammatory cascade and promulgate mechanisms resulting in cardiac dysfunction. Here, we review the mechanisms by which TNFα, IL-1 beta, IL-6, and IL-10 cause cardiac dysfunction in post-burn injuries. We additionally review changes in the cytokine transcriptome caused by inflammation and burn injuries.