NK-cell-elicited gasdermin-D-dependent hepatocyte pyroptosis induces neutrophil extracellular traps that facilitate HBV-related acute-on-chronic liver failure.

BACKGROUND AND AIMS: HBV infection is a major etiology of acute-on-chronic liver failure (ACLF). At present, the pattern and regulation of hepatocyte death during HBV-ACLF progression are still undefined. Evaluating the mode of cell death and its inducers will provide new insights for developing therapeutic strategies targeting cell death. In this study, we aimed to elucidate whether and how immune landscapes trigger hepatocyte death and lead to the progression of HBV-related ACLF. APPROACH AND RESULTS: We identified that pyroptosis represented the main cell death pattern in the liver of patients with HBV-related ACLF. Deficiency of MHC-I in HBV-reactivated hepatocytes activated cytotoxic NK cells, which in turn operated in a perforin/granzyme-dependent manner to trigger GSDMD/caspase-8-dependent pyroptosis of hepatocytes. Neutrophils selectively accumulated in the pyroptotic liver, and HMGB1 derived from the pyroptotic liver constituted an important factor triggering the generation of pathogenic extracellular traps in neutrophils (NETs). Clinically, elevated plasma levels of myeloperoxidase-DNA complexes were a promising prognostic biomarker for HBV-related ACLF. More importantly, targeting GSDMD pyroptosis-HMGB1 release in the liver abrogates NETs that intercept the development of HBV-related ACLF. CONCLUSIONS: Studying the mechanisms that selectively modulate GSDMD-dependent pyroptosis, as well as its immune landscapes, will provide a novel strategy for restoring the liver function of patients with HBV-related ACLF.

Ginsenoside Rg5 attenuates hepatic glucagon response via suppression of succinate-associated HIF-1α induction in HFD-fed mice.

AIMS/HYPOTHESIS: Ginsenosides regulate glucose homeostasis. This study investigated the effect of ginsenoside Rg5 (Rg5) on the hepatic glucagon response, focusing on the regulation of metabolism. METHODS: Mice fed a high-fat diet (HFD) showed increased hepatic glucose production (HGP). We observed the effects of Rg5 on hepatic fatty acid oxidation and glucagon response. The regulation of phosphodiesterase (PDE) 4B by succinate was also investigated in hepatocytes. RESULTS: Rg5 inhibited endogenous glucose production in HFD-fed mice. Rg5 reduced cyclic AMP (cAMP) accumulation and inhibited transcriptional regulation of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) by dephosphorylation of the cAMP response element-binding transcription factor in the liver, demonstrating the inhibitory effect on hepatic glucagon response. HFD feeding increased succinate accumulation in the liver due to the reversal of succinate dehydrogenase activation and triggered hypoxia-inducible factor-1α (HIF-1α) induction. Succinate prevented cAMP degradation by inactivating PDE4B, thereby increasing cAMP accumulation in response to glucagon. Knockdown of HIF-1α with small interfering RNA diminished the effect of succinate, indicating that HIF-1α was essential for succinate to inactivate PDE4B. Rg5 inhibited succinate accumulation in hepatocytes by combating fatty acid oxidation, and thus reduced cAMP accumulation by blocking succinate/HIF-1α induction. Rg5 reduced HGP as a consequence of the inhibition of the glucagon response. CONCLUSIONS/INTERPRETATION: Succinate acted as a metabolic signal to enhance the hepatic glucagon response. Rg5 reduced hepatic succinate accumulation by combating fatty acid oxidation and attenuated the hepatic glucagon response by suppressing succinate/HIF-1α induction, suggesting that succinate-associated HIF-1α induction in hepatocytes might be a therapeutic target in the treatment of diabetes.

A C-type lectin (OmCTL) in Onychostoma macrolepis: Binding ability to LPS, PGN and agglutinating activity against bacteria.

C-type lectins (CTLs) are calcium-dependent carbohydrate-binding proteins that mainly bind to carbohydrate-based or other ligands to mediate cell adhesion, recognize pathogens, and play important roles in the immune system. In the present study, a novel C-type lectin (OmCTL) isolated from Onychostoma macrolepis was investigated. The open reading frame of OmCTL comprises 468 bp, encoding a 155 amino acid polypeptide with an 18 amino acid putative signaling peptide. The predicted primary OmCTL structure contains a signal peptide, a single carbohydrate recognition domain (CRD) and an EPN/WND motif required for carbohydrate-binding specificity. Using tissue expression pattern analysis, OmCTL has been shownto be highly expressed in the liver, and is also detected in other tissues. OmCTL was significantly upregulated in the liver and spleen following infection with Aeromonas hydrophila, suggesting its involvement in immune response. The recombinant OmCTL protein (rOmCTL) agglutinated two gram-negative bacteria, Escherichia coli and A. hydrophila, in vitro in the presence of Ca2+, showing that it is a typical Ca2+-dependent carbohydrate-binding protein.Furthermore, rOmCTL purified from E. coli BL21 (DE3) strongly bound to LPS and PGN, as well as all tested bacteria in a Ca2+-independent manner. These results indicate that OmCTL plays a central role in the innate immune response and as a pattern recognition receptor that recognizes diverse pathogens among O. macrolepis.

[Multiscale influences of urbanized landscape metrics on the diversity of indigenous plant species: A case study in Shunyi District of Beijing, China.] / åŸŽå¸‚åŒ–æ™¯è§‚æ ¼å±€å¯¹æœ¬åœŸæ¤ç‰©å¤šæ ·æ€§çš„å¤šå°ºåº¦å½±å“­­ä»¥åŒ—京市顺义区为例.

The effects of landscape pattern on plant diversity have been widely reported in literature, with that of urban landscape remaining largely unknown. To explore the impacts of urbanization landscape pattern on plant diversity and its scale effect, 105 plots were investigated in Shunyi District, Beijing. The α and ß diversity of each plot were calculated, and 43 urban landscape indices of 10 scales in the range of 100-1000 m were analyzed with 100 m as the step. The results showed that the urban landscape area metric, core metrics and edge metrics were negatively related with diversity of indigenous plant species at all the examined scales. Shape complexity metrics contributed to plant diversity at small scale, while the area-weighted complexity metrics contributed at large scale. Other metrics, such as connection, proximity, cohesion, fragmentation and interspersion juxtaposition of urban patches showed a slight and unsteady relationship with the diversity of indigenous plant species. The urbanization intensity was negatively related with scales and with plant diversity at all scales. Urban landscape could better conserve indigenous plant diversity by reasonably dividing an urbanized area into many small patches with simple edge. Our results presented suitable urban landscape indicators for preserving plant diversity and suggestions for the construction of ecological cities.

NOTCH Signaling via WNT Regulates the Proliferation of Alternative, CCR2-Independent Tumor-Associated Macrophages in Hepatocellular Carcinoma.

Tumor-associated macrophages (TAM) play pivotal roles in tumor progression and metastasis, but the contribution and regulation of different macrophage populations remain unclear. Here we show that Notch signaling plays distinct roles in regulating different TAM subsets in hepatocellular carcinoma (HCC). Myeloid-specific NOTCH blockade by conditional disruption of recombination signal binding protein Jκ (RBPj cKO) significantly delayed the growth of subcutaneously inoculated Lewis lung carcinoma (LLC), but accelerated orthotopically inoculated hepatic Hepa1-6 tumors in mice. In contrast to subcutaneous LLC, RBPj cKO significantly increased the number of TAMs in hepatic Hepa1-6 tumors despite impeded differentiation of monocyte-derived TAMs (moTAM). The dominating TAMs in orthotopic HCC manifested properties of Kupffer cells (KC) and hence are tentatively named KC-like TAMs (kclTAM). The increased proliferation of RBPj cKO kclTAMs was maintained even in Ccr2 -/- mice, in which moTAMs were genetically blocked. NOTCH signaling blockade accelerated proliferation of kclTAMs via enhanced ß-catenin-dependent WNT signaling, which also downregulated IL12 and upregulated IL10 expression by kclTAMs likely through c-MYC. In addition, myeloid-specific RBPj cKO facilitated hepatic metastasis of colorectal cancer but suppressed lung metastasis in mice, suggesting that the phenotype of RBPj cKO in promoting tumor growth was liver-specific. In patient-derived HCC biopsies, NOTCH signaling negatively correlated with WNT activation in CD68+ macrophages, which positively correlated with advanced HCC stages. Therefore, NOTCH blockade impedes the differentiation of moTAMs, but upregulates Wnt/ß-catenin signaling to promote the proliferation and protumor cytokine production of kclTAMs, facilitating HCC progression and hepatic metastasis of colorectal cancer. SIGNIFICANCE: These findings highlight the role of NOTCH and WNT signaling in regulating TAMs in hepatocellular carcinoma.

The new plant Parinari kerstingii Engl.: Toxicity studies and anti-inflammatory properties.

ETHNOPHARMACOLOGICAL RELEVANCE: Parinari kerstingii Engl. extract is traditionally used for the treatment of inflammation, bronchopneumonia, feverish pains, and breast cancer. However, there have not been any scientific reports regarding the medicinal properties of this plant, and no experiments have been done to ascertain the safety of the extract. AIM OF THE STUDY: The objective of this work was to evaluate the toxicity of Parinari kerstingii Engl. extracts as an herbal remedy and to investigate its anti-inflammatory potential in vivo. MATERIALS AND METHODS: Sprague-Dawley albino male rats were used in these experiments. 100, 300 and 600 mg/kg of body weight doses of Parinari kerstingii Engl. water extract (PKWE) were used for a 14 day toxicity study. For the anti-inflammatory studies, the carrageenan-induced paw edema model was used to investigate the effect of four fractions of Parinari kerstingii Engl. ethanol extract [petroleum ether (fraction A), ethyl acetate (fraction B), n -butanol (fraction C) and water (fraction D)] on the paw size of rats and to investigate the inhibitory effects of Parinari kerstingii Engl. water (PKWE) and Parinari kerstingii Engl. ethanol extract (PKEE). RESULTS: The administration of 100 mg/kg and 300 mg/kg of body weight doses of Parinari kerstingii Engl. water extract showed no sign of toxicity. However, the 600 mg/kg of body weight dose showed a very significant increase in creatinine concentration. All the fractions of Parinari kerstingii Engl. extract demonstrated anti-inflammatory effects, as shown by a significant reduction in carrageenan-induced paw edema and by a significant decrease in the production of IL-1, TNF-α, COX-2, NF-кB, and PGE2. Moreover, fraction A and B showed enhanced in vivo anti-inflammatory effects compared to aspirin. Furthermore, PKEE was demonstrated to be more effective than PKWE. CONCLUSION: We present the first report on the plant Parinari kerstingii Engl. Based on our findings, PKWE at a dose of up to 300 mg/kg of body weight for 14 days is considered safe, and our anti-inflammatory results support its traditional use. Overall, Parinari kerstingii Engl. has been demonstrated to be a potential drug candidate. Thus, further experiments, such as isolation/structural elucidation of the phytochemicals and biological screening of this plant, need to be done.

Succinate induces aberrant mitochondrial fission in cardiomyocytes through GPR91 signaling.

Altered mitochondrial metabolism acts as an initial cause for cardiovascular diseases and metabolic intermediate succinate emerges as a mediator of mitochondrial dysfunction. This work aims to investigate whether or not extracellular succinate accumulation and its targeted G protein-coupled receptor-91 (GPR91) activation induce cardiac injury through mitochondrial impairment. The results showed that extracellular succinate promoted the translocation of dynamin-related protein 1 (Drp1) to mitochondria via protein kinase Cδ (PKCδ) activation, and induced mitochondrial fission factor (MFF) phosphorylation via extracellular signal-regulated kinases-1/2 (ERK1/2) activation in a GPR91-dependent manner. As a result, enhanced localization of MFF and Drp1 in mitochondria promoted mitochondrial fission, leading to mitochondrial dysfunction and cardiomyocyte apoptosis. We further showed that inhibition of succinate release and GPR91 signaling ameliorated oxygen-glucose deprivation-induced injury in cardiomyocytes and isoproterenol-induced myocardial ischemia injury in mice. Taken together, these results showed that in response to cardiac ischemia, succinate release activated GPR91 and induced mitochondrial fission via regulation of PKCδ and ERK1/2 signaling branches. These findings suggest that inhibition of extracellular succinate-mediated GPR91 activation might be a potential therapeutic strategy for protecting cardiomyocytes from ischemic injury.

Evaluation of genotoxicity of combined soil pollution by cadmium and phenanthrene on earthworm.

The DNA-damaging effects of the combined pollution of heavy metal and organic contamination on earthworms were evaluated by single cell gel electrophoresis (SCGE) assay. Earthworms Eisenia andrei were exposed to single or combined test compounds in different doses of cadmium (Cd) 5, 10, 50 mg/kg and phenanthrene (Phe) 0.5, 2.5, 12.5 mg/kg with a treatment of 14 d. In SCGE assay, isolated coelomcytes and electrophoresis were employed to determine DNA damage degree after a 14-d treatment by test compounds. The results showed that there was a significant statistical difference between earthworms treated with Cd combined Phe with them treated alone with Cd or Phe. The Olive tail moment (OTM) of SCGE assay using earthworm coelomcytes appears to be a sensitive biomarker for evaluating exposure to genotoxic compounds. These tests also revealed that the interaction between Cd and Phe to DNA damaging effects was negative, and was strongly dependent on the concentration of pollution. This study corresponds to exploratory phase in order to reveal interaction effects of heavy metal and organic contamination on earthworms and then to set up more in-depth analysis to increase progressively the understanding of the genotoxicity mechanisms involved.

Screening on oil-decomposing microorganisms and application in organic waste treatment machine.

As an oil-decomposable mixture of two bacteria strains (Bacillus sp. and Pseudomonas sp.), Y3 was isolated after 50 d domestication under the condition that oil was used as the limited carbon source. The decomposing rate by Y3 was higher than that by each separate individual strain, indicating a synergistic effect of the two bacteria. Under the conditions that T = 25-40 degrees C, pH = 6-8, HRT (Hydraulic retention time) = 36 h and the oil concentration at 0.1%, Y3 yielded the highest decomposing rate of 95.7%. Y3 was also applied in an organic waste treatment machine and a certain rate of activated bacteria was put into the stuffing. A series of tests including humidity, pH, temperature, C/N rate and oil percentage of the stuffing were carried out to check the efficacy of oil-decomposition. Results showed that the oil content of the stuffing with inoculums was only half of that of the control. Furthermore, the bacteria were also beneficial to maintain the stability of the machine operating. Therefore, the bacteria mixture as well as the machines in this study could be very useful for waste treatment.