Resolvin D1 promotes the resolution of inflammation in the ACLF rat model by increasing the proportion of Treg cells.

OBJECTIVE: Acute-on-chronic liver failure (ACLF) causes organ system failures in patients and increases the risk of mortality. One of the main predictors of ACLF development in patients is the severity of systemic inflammation. The purpose of this study was to explore the effects of resolvin D1 (RvD1) on the rat model of ACLF. METHODS: The ACLF rats were induced by first intraperitoneally (ip) injecting CCl4 and porcine serum for 6 weeks to establish the chronic liver injury, followed by once administration (ip) of lipopolysaccharide and d-galactose d-GalN to cause acute liver injury (ALI). An hour before the ALI-induced treatment, rats were administrated (ip) with 0.9% saline or different doses of RvD1 (0.3 or 1 µg/kg). Afterward, the control and treated rats were killed and samples were collected. Biochemical analysis, hematoxylin-eosin and Sirius red staining, flow cytometry assay, and real-time polymerase chain reaction were used to assess the rat liver histopathological injury, the percentage of Treg cells in the spleen, and the messenger RNA (mRNA) levels of transcription factors and immunologic cytokines in liver. RESULTS: The necroinflammatory scores and the serum levels of transaminase significantly increased in ACLF rats compared with those in control rats. These impaired changes observed in ACLF rats could be attenuated by the administration of a low dose of RvD1 before the induction of ALI, which was associated with the increased proportion of regulatory T cells (Treg) in the spleen together with the increased gene expression ratio of Foxp3/RORγt and decreased mRNA level of Il-17a and Il-6 in the liver. CONCLUSION: A low dose of RvD1 can promote the resolution of inflammation in ACLF rats by increasing the proportion of Treg cells. RvD1, therefore, may be used as a potential drug for the treatment of patients with ACLF.

The anti-inflammatory effects of cinnamyl alcohol on sepsis-induced mice via the NLRP3 inflammasome pathway.

Background: Sepsis is an excessive inflammatory response to an infection that fails to return to homeostasis. It occurs frequently in patients following a primary infection or injury and is one of the most common causes of mortality in hospitalized patients. However, there is currently no specific and effective therapy for the management of sepsis. Previous findings have suggested that cinnamon and cinnamon extracts have anti-inflammatory and anti-oxidative activities and therefore, may be effective in treating sepsis. Methods: In the present study, Escherichia coli was injected into mice to induce sepsis. Hematoxylin and eosin staining was used to investigate the influence of cinnamyl alcohol on histological changes including heart, liver, lung, and kidney tissues. Western blotting and real-time polymerase chain reaction (RT-PCR) were applied to measure the levels of NLRP3 inflammasome. The levels of interleukin (IL)-1ß and IL-18 in the serum were detected with enzyme-linked immunosorbent assay (ELISA) method. Results: Administration of cinnamyl alcohol by gavage effectively reduced the mortality of septic mice (70% survival), compared to untreated septic mice (50% survival). The histological findings indicated that cinnamyl alcohol reduced the inflammatory reaction in the liver, heart, lungs, and kidneys of the septic mice. In the circulatory system, the concentrations of the inflammatory cytokines IL-1ß and IL-18 were significantly decreased by cinnamyl alcohol administration compared to the untreated septic group. Western blot analysis and quantitative polymerase chain reaction (qPCR) demonstrated that cinnamyl alcohol decreased the expression of apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain (ASC), nucleotide-binding oligomerization domain-like receptor 3 (NLRP3), and caspase-1 in the liver, heart, lungs, and kidneys of the mice, suggesting that cinnamyl alcohol alleviated sepsis syndrome via the NLRP3 inflammasome pathway. Conclusions: Cinnamyl alcohol may be a novel therapeutic candidate for the treatment of sepsis syndrome.

HBx co-localizes with COXIII in HL-7702 cells to upregulate mitochondrial function and ROS generation.

Hepatocellular carcinoma (HCC) is one of the most common malignant diseases, and HBx leads to the development of HBV-associated HCC. Mitochondria are key organelles that regulate apoptosis, cellular energetics and signal transduction pathways, and are the source of HBx-induced reactive oxygen species (ROS). Recent findings have shown that HBx interacts with the inner mitochondrial membrane protein, COXIII, via the yeast two-hybrid system, mating experiment and coimmunoprecipitation. The aim of the present study was to examine the co-localizaiton of HBx and COXIII in HL-7702 cells and to investigate ensuing alterations of mitochondrial function. An HL-7702 cell line stably expressing the HBx gene by lentivirus vectors was constructed. Confocal microscopy was utilized to assess the interaction between HBx protein and COXIII. Expression of COXIII, activities of cytochrome c oxidase (COX) and the mitochondrial membrane potential, which were functionally relevant to the HBx protein-COXIII interaction, were investigated in cell cultures. Moreover, the intracellular ROS levels were detected by flow cytometry. The results demonstrated that HBx co-localized with the inner mitochondrial protein, COXIII, in HL-7702 cells, causing the upregulation of COXIII protein expression as well as COX activity. However, HBx did not alter the mitochondrial membrane potential and mitochondria exhibited only slight swelling in HL-7702-HBx cells. Moreover, HBx elevated the generation of mitochondrial ROS in HL-7702-HBx cells. The main finding of the present study was that the co-localization of HBx and COXIII leads to upregulation of the mitochondrial function and ROS generation, which are associated with the oncogenesis of HBV-associated HCC.

The co-localization of HBx and COXIII upregulates COX-2 promoting HepG2 cell growth.

HBx is a multifunctional regulator that interacts with host factors to contribute to the development of hepatocellular carcinoma. In this study, to explore the co-localization of HBx and COXIII in HepG2 cells and to investigate the molecular mechanism of HBx in HepG2 cell growth promotion, we first constructed a HepG2 cell line stably expressing the HBx gene in vitro by lentivirus vectors. In addition, we found that HBx co-localized with the inner mitochondrial protein, COXIII, in HepG2 cells by confocal laser scanning microscopy. It led to changes of mitochondrial biogenesis and morphology, including upregulation of COXIII protein expression, increased cytochrome c oxidase activity and higher mitochondrial membrane potential. The upregulation of COX-2 caused by HBx through generation of mitochondrial reactive oxygen species promoted cell growth. Thus, we conclude that co-localization of HBx and COXIII leads to upregulation of COX-2 that promotes HepG2 cell growth. Such a mechanism provides deeper insights into the molecular mechanism of HBV-associated hepatocellular carcinoma.