RING finger protein 13 protects against nonalcoholic steatohepatitis by targeting STING-relayed signaling pathways.

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disorder worldwide. Recent studies show that innate immunity-related signaling pathways fuel NAFLD progression. This study aims to identify potent regulators of innate immunity during NAFLD progression. To this end, a phenotype-based high-content screening is performed, and RING finger protein 13 (RNF13) is identified as an effective inhibitor of lipid accumulation in vitro. In vivo gain- and loss-of-function assays are conducted to investigate the role of RNF13 in NAFLD. Transcriptome sequencing and immunoprecipitation-mass spectrometry are performed to explore the underlying mechanisms. We reveal that RNF13 protein is upregulated in the liver of individuals with NASH. Rnf13 knockout in hepatocytes exacerbate insulin resistance, steatosis, inflammation, cell injury and fibrosis in the liver of diet-induced mice, which can be alleviated by Rnf13 overexpression. Mechanically, RNF13 facilitates the proteasomal degradation of stimulator of interferon genes protein (STING) in a ubiquitination-dependent way. This study provides a promising innate immunity-related target for NAFLD treatment.

Oit3, a promising hallmark gene for targeting liver sinusoidal endothelial cells.

Liver sinusoidal endothelial cells (LSECs) play a pivotal role in maintaining liver homeostasis and influencing the pathological processes of various liver diseases. However, neither LSEC-specific hallmark genes nor a LSEC promoter-driven Cre mouse line has been introduced before, which largely restricts the study of liver diseases with vascular disorders. To explore LSEC-specific hallmark genes, we compared the top 50 marker genes between liver endothelial cells (ECs) and liver capillary ECs and identified 18 overlapping genes. After excluding globally expressed genes and those with low expression percentages, we narrowed our focus to two final candidates: Oit3 and Dnase1l3. Through single-cell RNA sequencing (scRNA-seq) and analysis of the NCBI database, we confirmed the extrahepatic expression of Dnase1l3. The paired-cell sequencing data further demonstrated that Oit3 was predominantly expressed in the midlobular liver ECs. Subsequently, we constructed inducible Oit3-CreERT2 transgenic mice, which were further crossed with ROSA26-tdTomato mice. Microscopy validated that the established Oit3-CreERT2-tdTomato mice exhibited significant fluorescence in the liver rather than in other organs. The staining analysis confirmed the colocalization of tdTomato and EC markers. Ex-vivo experiments further confirmed that isolated tdTomato+ cells exhibited well-differentiated fenestrae and highly expressed EC markers, confirming their identity as LSECs. Overall, Oit3 is a promising hallmark gene for tracing LSECs. The establishment of Oit3-CreERT2-tdTomato mice provides a valuable model for studying the complexities of LSECs in liver diseases.

Catalytic enantioselective desymmetrization of meso-aziridines.

As a type of readily available small strained-ring heterocycle, meso-aziridines may undergo catalytic desymmetrizing transformations to empower the rapid construction of diverse nitrogen-containing structures bearing contiguous stereocenters, which have great relevance in natural product synthesis, drug development and the design and synthesis of chiral catalysts/ligands for asymmetric catalysis. This review outlines the advances achieved in the catalytic asymmetric desymmetrization of meso aziridines and highlights some promising avenues for further work in this realm.

Molecular pathogenesis: Connections between viral hepatitis-induced and non-alcoholic steatohepatitis-induced hepatocellular carcinoma.

Hepatocellular carcinoma(HCC) is the sixth most common cancer in the world and is usually caused by viral hepatitis (HBV and HCV), alcoholic, and non-alcoholic fatty liver disease(NAFLD). Viral hepatitis accounts for 80% of HCC cases worldwide. In addition, With the increasing incidence of metabolic diseases, NAFLD is now the most common liver disease and a major risk factor for HCC in most developed countries. This review mainly described the specificity and similarity between the pathogenesis of viral hepatitis(HBV and HCV)-induced HCC and NAFLD-induced HCC. In general, viral hepatitis promotes HCC development mainly through specific encoded viral proteins. HBV can also exert its tumor-promoting mechanism by integrating into the host chromosome, while HCV cannot. Viral hepatitis-related HCC and NASH-related HCC differ in terms of genetic factors, and epigenetic modifications (DNA methylation, histone modifications, and microRNA effects). In addition, both of them can lead to HCC progression through abnormal lipid metabolism, persistent inflammatory response, immune and intestinal microbiome dysregulation.

Twin Boundary Superstructures Assembled by Periodic Segregation of Solute Atoms.

Twinning is a common deformation mechanism in metals, and twin boundary (TB) segregation of impurities/solutes plays an important role in the performances of alloys such as thermostability, mobility, and even strengthening. The occurrence of such segregation phenomena is generally believed as a one-layer coverage of solutes alternately distributed at extension/compression sites, in an orderly, continuous manner. However, in the Mn-free and Mn-containing Mg-Nd model systems, we reported unexpected three- and five-layered discontinuous segregation patterns of the coherent {101̅1} TBs, and not all the extension sites occupied by solutes larger in size than Mg, and even some larger sized solutes taking the compression sites. Nd/Mn solutes selectively segregate at substitutional sites and thus to generate two new types of ordered two-dimensional TB superstructures or complexions. These findings refresh the understanding of solute segregation in the perfect coherent TBs and provide a meaningful theoretical guidance for designing materials via targeted TB segregation.

Catalytic Asymmetric [3 + 2] Annulation of Hantzsch Esters with Racemic N-Sulfonylaziridines.

Hantzsch esters (HEs) served as two-carbon partners in a copper(I)-catalyzed enantioselective [3 + 2] annulation with racemic 2-(hetero)aryl-N-sulfonyl aziridines via kinetic resolution to provide pyrrolo[2,3-b]tetrahydropyridines containing multiple contiguous stereogenic centers including all-carbon quaternary centers in excellent yields and enantiopurities and moderate-to-excellent diastereoselectivities. Mainly dependent upon the structures of the aziridines, a competitive hydrogenolysis process with HEs as the hydrogen source was also observed in some cases.

Tripartite motif 16 ameliorates nonalcoholic steatohepatitis by promoting the degradation of phospho-TAK1.

Nonalcoholic steatohepatitis (NASH)-related hepatocellular carcinoma and liver disorders have become the leading causes for the need of liver transplantation in developed countries. Lipotoxicity plays a central role in NASH progression by causing endoplasmic reticulum stress and disrupting protein homeostasis. To identify key molecules that mitigate the detrimental consequences of lipotoxicity, we performed integrative multiomics analysis and identified the E3 ligase tripartite motif 16 (TRIM16) as a candidate molecule. In particular, we found that lipid accumulation and inflammation in a mouse NASH model is mitigated by TRIM16 overexpression but aggravated by its depletion. Multiomics analysis showed that TRIM16 suppressed NASH progression by attenuating the activation of the mitogen-activated protein kinase (MAPK) signaling pathway; specifically, by preferentially interacting with phospho-TAK1 to promote its degradation. Together, these results identify TRIM16 as a promising therapeutic target for the treatment of NASH.

Adoptive transfer of polarized M2c macrophages ameliorates acute rejection in rat liver transplantation.

Hepatic macrophages play pivotal roles in tolerance induction after liver transplantation (LT). However, macrophages possess functional heterogeneities, and the protective role of M2c macrophages, a macrophage subtype characterized by the surface marker CD163 that secretes interleukin-10 (IL-10) and transforming growth factor-ß1 (TGF-ß1), in acute rejection following LT, has not been addressed. The aim of this study was to determine whether polarized macrophages of the M2c subtype could improve outcomes after LT for rats, including survival rate, liver function, and inflammatory infiltration. In our study, the numbers of CD163-positive cells were found to be increased in tolerant liver grafts. Immediately following the surgery, M2c macrophages induced from rat bone marrow-derived cells were infused into recipients; this significantly improved survival rate and liver function. The expression levels of IL-10 and TGF-ß1 were markedly increased in these rats compared to those in the control group. Furthermore, CD8+ T-cell infiltration was reduced, whereas the numbers of apoptotic cells increased, in rats treated with M2c. To explore the mechanisms of the protective role of M2c, the numbers of major histocompatibility complex (MHC) class II positive cells were found to be decreased and the expression of N-acetylglucosaminyltransferase V (MGAT5) was up-regulated in M2c infusion groups. Together, these findings demonstrate that polarization of macrophages towards the M2c phenotype ameliorated acute rejection in a rat LT model and may provide a novel and effective therapeutic approach for AR after transplantation.

Translationally controlled tumor protein exerts a proinflammatory role in acute rejection after liver transplantation.

BACKGROUND: Translationally controlled tumor protein (TCTP), which has been verified to have a proinflammatory activity, plays an important role in allergy. However, it remains unclear whether TCTP has an impact on the acute rejection (AR) after liver transplantation. METHODS: Three protocols were used to delineate the role of TCTP in AR after liver transplantation. First, in rat orthotopic liver transplantation (OLT), the expression of TCTP was measured by enzyme-linked immunosorbent assay (ELISA), real-time PCR, Western blot and immunofluorescence assays. Second, in mixed lymphocyte reaction (MLR), the role of TCTP in lymphocyte proliferation was measured by carboxyfluorescein succinimidyl ester (CFSE) labeling and the impact of TCTP on inflammatory factor release was detected by cytokine arrays. Third, in human OLT, the level of serum TCTP was detected by ELISA, and the relationship between TCTP and model for early allograft function (MEAF) score was assessed by Spearman's correlation. RESULTS: In rat OLT, AR resulted in great harm to allografts, manifesting as deterioration of liver function, increasing inflammatory factors and infiltrating lymphocytes. Meanwhile, TCTP was overexpressed in serum and allografts. Higher level of TCTP was associated with higher rejection activity index (RAI). In an MLR protocol, TCTP knockdown inhibited the proliferation of mixed inflammatory cells and significantly suppressed the release of 15 cytokines and chemokines. In human OLT, the serum TCTP was up-regulated within a week after operation. Additionally, the increasing speed of serum TCTP positively correlated with MEAF scores (r = 0.449; P = 0.0088). CONCLUSIONS: Up-regulated TCTP positively affects AR after liver transplantation.

Up-Regulated CCDC34 Contributes to the Proliferation and Metastasis of Hepatocellular Carcinoma.

BACKGROUND: Coiled-coil domain-containing protein 34 (CCDC34), which belongs to the CCDCs family, has been recently reported to be up-regulated in various kinds of tumors. However, its role in the development of hepatocellular carcinoma (HCC) still remains unclear. MATERIALS AND METHODS: In this study, real-time polymerase chain reaction (RT-PCR) and Western blot analysis were performed to measure the mRNA and protein levels of CCDC34 in clinical samples. Kaplan-Meier method was used to analyze the relationship between CCDC34 and the prognosis in HCC patients. CCK-8 and colony formation assays were conducted to investigate CCDC34's effect on the cell proliferation, and Transwell assays were used to detect CCDC34's effect on the cell metastasis. Moreover, subcutaneous xenograft tumor model and lung metastasis model were applied to confirm the impact of CCDC34 on the HCC development. Lastly, RNA sequencing and Western blot analysis were performed to probe the underlying mechanism of CCDC34's effect on HCC. RESULTS: CCDC34 was significantly induced in HCC tissues, and the overexpression of CCDC34 predicted the poor outcomes among HCC patients. It was verified by the in vitro and in vivo experiments that CCDC34-knockdown potently inhibited the proliferation and metastasis of HCC cells. Subsequent results indicated that CCDC34 inhibition can affect the activation of protein kinase B (PKB or AKT) as well as epithelial-mesenchymal transition (EMT) process. CONCLUSION: CCDC34 is significantly associated with HCC. It will become a promising prognostic biomarker and therapeutic target against HCC.

Correction: Translationally controlled tumor protein promotes liver regeneration by activating mTORC2/AKT signaling.

Reference 26 reads "Hua, J. et al. TCTP and CSN4 control cell cycle progression and development by regulating CULLIN1 neddylation in plants and animals. PLoS Genet. 15, e1007899 (2019)." However, it should read "Betsch, L. et al. TCTP and CSN4 control cell cycle progression and development by regulating CULLIN1 neddylation in plants and animals. PLoS Genet. 15, e1007899 (2019)".

Translationally controlled tumor protein promotes liver regeneration by activating mTORC2/AKT signaling.

Translationally controlled tumor protein (TCTP), which is a protein characterized by its potent proliferation promoting activity, has been well studied in the area of growth and tumorigenesis. However, the specific role of TCTP in liver regeneration (LR) and its underlying mechanism remains unclear. In order to investigate the contribution of TCTP during LR, heterozygous TCTP mice were generated, and a mimic LR model was applied to TCTP-knockdown (KD) hepatic cell lines. The results revealed that TCTP-KD impaired LR in mice, and manifested as the following aspects: delayed proliferation of hepatocytes, accompanied by disruption of the mRNA expression of markers of the cell cycle, degenerated lipid metabolism, and abnormal immune response. Furthermore, it was found out that TCTP activated PI3K/AKT signaling by regulating mTORC2. Lastly, the increasing rate of serum TCTP positively correlated to the recovery of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) after liver resection in humans. In summary, the present study is the first to reveal the crucial role of intracellular TCTP in LR.

Immortalization of porcine hepatocytes with a α-1,3-galactosyltransferase knockout background.

BACKGROUND: In vivo pig liver xenotransplantation preclinical trials appear to have poor efficiency compared to heart or kidney xenotransplantation because of xenogeneic rejection, including coagulopathy, and particularly thrombocytopenia. In contrast, ex vivo pig liver (wild type) perfusion systems have been proven to be effective in "bridging" liver failure patients until subsequent liver allotransplantation, and transgenic (human CD55/CD59) modifications have even prolonged the duration of pig liver perfusion. Despite the fact that hepatocyte cell lines have also been proposed for extracorporeal blood circulation in conditions of acute liver failure, porcine hepatocyte cell lines, and the GalT-KO background in particular, have not been developed and applied in this field. Herein, we established immortalized wild-type and GalT-KO porcine hepatocyte cell lines, which can be used for artificial liver support systems, cell transplantation, and even in vitro studies of xenotransplantation. METHODS: Primary hepatocytes extracted from GalT-KO and wild-type pigs were transfected with SV40 LT lentivirus to establish immortalized GalT-KO porcine hepatocytes (GalT-KO-hep) and wild-type porcine hepatocytes (WT). Hepatocyte biomarkers and function-related genes were assessed by immunofluorescence, periodic acid-Schiff staining, indocyanine green (ICG) uptake, biochemical analysis, ELISA, and RT-PCR. Furthermore, the tumorigenicity of immortalized cells was detected. In addition, a complement-dependent cytotoxicity (CDC) assay was performed with GalT-KO-hep and WT cells. Cell death and viability rates were assessed by flow cytometry and CCK-8 assay. RESULTS: GalT-KO and wild-type porcine hepatocytes were successfully immortalized and maintained the characteristics of primary porcine hepatocytes, including albumin secretion, ICG uptake, urea and glycogen production, and expression of hepatocyte marker proteins and specific metabolic enzymes. GalT-KO-hep and WT cells were confirmed as having no tumorigenicity. In addition, GalT-KO-hep cells showed less apoptosis and more viability than WT cells when exposed to complement and xenogeneic serum. CONCLUSIONS: Two types of immortalized cell lines of porcine hepatocytes with GalT-KO and wild-type backgrounds were successfully established. GalT-KO-hep cells exhibited higher viability and injury resistance against a xenogeneic immune response.

Berberine Inhibits Growth of Liver Cancer Cells by Suppressing Glutamine Uptake.

INTRODUCTION: Glutamine metabolism is essential for the proliferation of cancer cells. Transported by SLC1A5, a Na+ dependent transporter, glutamine is absorbed for further use. Recent studies have revealed the anti-tumor effect of berberine. The present study aimed to evaluate the effect of berberine on cancer cell glutamine metabolism. MATERIALS AND METHODS: The inhibitory effect of berberine on liver cancer cells was analyzed by CCK-8 and EdU assay. The glutamine concentrations were detected by ELISA and UHPLC-MRM-MS analysis. Glutamine metabolism-related proteins were determined by Western blot, immunofluorescent analysis and immunohistochemistry. RESULTS: Berberine inhibited the proliferation of Hep3B and BEL-7404 cell in vitro. Berberine suppressed the glutamine uptake by inhibiting SLC1A5. The upregulation of SLC1A5 led to an increased glutamine uptake and improved tolerance to berberine. Berberine suppresses SLC1A5 expression by inhibiting c-Myc. Furthermore, berberine suppresses the growth of tumor xenografts, and the expression of SLC1A5 and c-Myc in vivo. The high expression of SLC1A5 in hepatocellular carcinoma (HCC) tissues is associated with poor prognosis. CONCLUSION: Berberine can suppress the proliferation of liver cancer cells by reducing SLC1A5 expression.

Lewis Acid Catalyzed Dynamic Kinetic Asymmetric Transformation of Racemic N-Sulfonylaziridines.

The first Lewis acid catalyzed stereoconvergent transformation of racemic 2-(hetero)aryl- N-sulfonylaziridines via C-N bond cleavage with nucleophiles is presented. This includes the [3 + 2] annulations with (hetero)aromatic aldehydes and 1,3-disubstituted indoles, asymmetric Friedel-Crafts type reaction with electron-rich (hetero)arenes, and asymmetric aminolysis with amines, providing facile access to chiral 1,3-isoxazolidines, pyrroloindolines, 2-(hetero)arylphenethylamines, and vicinal diamines. This method features a simple and cheaply available complex of Cu(I)-chiral BINAP catalyst, excellent yield and high diastereo- and enantioselectivities, and mild reaction conditions. A mechanism involving type I dynamic kinetic asymmetric transformations (DyKATs) of the racemic aziridines is proposed based on the results of control experiments.

Quasicontinuum Simulation of the Effect of Lotus-Type Nanocavity on the Onset Plasticity of Single Crystal Al during Nanoindentation.

Stress concentration around nanosized defects such as cavities always leads to plastic deformation and failure of solids. We investigate the effects of depth, size, and shape of a lotus-type nanocavity on onset plasticity of single crystal Al during nanoindentation on a (001) surface using a quasicontinuum method. The results show that the presence of a nanocavity can greatly affect the contact stiffness (Sc) and yield stress (σy) of the matrix during nanoindentation. For a circular cavity, the Sc and σy gradually increase with the cavity depth. A critical depth can be identified, over which the Sc and σy are insensitive to the cavity depth and it is firstly observed that the nucleated dislocations extend into the matrix and form a y-shaped structure. Moreover, the critical depth varies approximately linearly with the indenter size, regarding the same cavity. The Sc almost linearly decreases with the cavity diameter, while the σy is slightly affected. For an ellipsoidal cavity, the Sc and σy increase with the aspect ratio (AR), while they are less affected when the AR is over 1. Our results shed light in the mechanical behavior of metals with cavities and could also be helpful in designing porous materials and structures.

Synthesis of Chiral Vicinal Diamines by Silver(I)-Catalyzed Enantioselective Aminolysis of N-Tosylaziridines.

The kinetic resolution of 2-aryl-N-tosylaziridines and the asymmetric desymmetrization of meso-N-tosylaziridines by ring openings with various primary and secondary anilines, and aliphatic amines as nucleophile have been realized by using a single silver(I)/chiral diphosphine complex as catalyst for the first time. The simple starting materials, broad scope, and easy scalability render this protocol a practical way to chiral vicinal diamine derivatives.

[3 + 2]-Annulations of N-alkyl-3-substituted indoles with quinone monoketals catalysed by Brønsted acids.

An organocatalytic dearomative [3 + 2]-annulation of N-alkyl-3-alkylindoles with quinone monoketals is developed. The reaction provides a mild and straightforward way to various benzofuro[2,3-b]indolines of potential biological and pharmaceutical interest in moderate to good yields. Moreover, when 3-phenylindole, a problematic substrate in previous relevant studies, was used as the substrate under the otherwise same reaction conditions, a novel 1,2-shift of the phenyl group occurred followed by aromatization to provide 2,3-diaryl indoles useful for cancer therapy studies in moderate yields.

[Determination of Flavonoids in Cycas revoluta Leaves by Chemiluminescence-Flow Injection Analysis Method].

OBJECTIVE: To detect flavonoids from Cycas revoluta leaves by means of Chemiluminescence-Flow Injection Analysis (CL-FIA). METHODS: Under alkaline condition, a CL-FIA method was established to determine flavonoids from leaves of Cycas revoluta on the basis of inhibiting effect of flavonoids to the Luminol-H2O2-Cu2+ chemiluminescence system and the reversed flow injection technique. RESULTS: In the range of 2. 0 x 10(-6) ~ 1. 0 x 10(-3) mg/mL, the decrease of CL intensity was correlated with flavonoids concentration while the detection limit was 0. 0265 µg/mL. Under the optimized conditions, the flavonoids of Cycas revoluta leaves were detected with its average rate reaching 1. 61% and RSD 1. 32%. CONCLUSION: Through the interference test and compared with the data of CL-FIA and UV, it is concluded that CL-FIA can be used in the analysis and detection of flavonoids from Cycas revoluta leaves.