E3 ubiquitin ligase ring finger protein 5 protects against hepatic ischemia reperfusion injury by mediating phosphoglycerate mutase family member 5 ubiquitination.

BACKGROUND AND AIMS: Hepatic ischemia-reperfusion (HIR) injury, a common clinical complication of liver transplantation and resection, affects patient prognosis. Ring finger protein 5 (RNF5) is an E3 ubiquitin ligase that plays important roles in endoplasmic reticulum stress, unfolded protein reactions, and inflammatory responses; however, its role in HIR is unclear. APPROACH AND RESULTS: RNF5 expression was significantly down-regulated during HIR in mice and hepatocytes. Subsequently, RNF5 knockdown and overexpression of cell lines were subjected to hypoxia-reoxygenation challenge. Results showed that RNF5 knockdown significantly increased hepatocyte inflammation and apoptosis, whereas RNF5 overexpression had the opposite effect. Furthermore, hepatocyte-specific RNF5 knockout and transgenic mice were established and subjected to HIR, and RNF5 deficiency markedly aggravated liver damage and cell apoptosis and activated hepatic inflammatory responses, whereas hepatic RNF5 transgenic mice had the opposite effect compared with RNF5 knockout mice. Mechanistically, RNF5 interacted with phosphoglycerate mutase family member 5 (PGAM5) and mediated the degradation of PGAM5 through K48-linked ubiquitination, thereby inhibiting the activation of apoptosis-regulating kinase 1 (ASK1) and its downstream c-Jun N-terminal kinase (JNK)/p38. This eventually suppresses the inflammatory response and cell apoptosis in HIR. CONCLUSIONS: We revealed that RNF5 protected against HIR through its interaction with PGAM5 to inhibit the activation of ASK1 and the downstream JNK/p38 signaling cascade. Our findings indicate that the RNF5-PGAM5 axis may be a promising therapeutic target for HIR.

Interaction analysis of gene variants related to one-carbon metabolism with chronic hepatitis B infection in Chinese patients.

BACKGROUND: The risk of chronic hepatitis B (CHB) infection is influenced by aberrant DNA methylation and altered nucleotide synthesis and repair, possibly caused by polymorphic variants in one-carbon metabolism genes. In the present study, we investigated the relationship between polymorphisms belonging to the one-carbon metabolic pathway and CHB infection. METHODS: A case-control study using 230 CHB patients and 234 unrelated healthy controls was carried out to assess the genetic association of 24 single nucleotide polymorphisins (SNPs) determined by mass spectrometry. RESULTS: Three SNPs, comprising rs10717122 and rs2229717 in serine hydroxymethyltransferase1/2 (SHMT2) and rs585800 in betaine-homocysteine S-methyltransferase (BHMT), were associated with the risk of CHB. Patients with DEL allele, DEL.DEL and DEL.T genotypes of rs10717122 had a 1.40-, 2.00- and 1.83-fold increased risk for CHB, respectively. Cases inheriting TA genotype of rs585800 had a 2.19-fold risk for CHB infection. The T allele of rs2229717 was less represented in the CHB cases (odds ratio = 0.66, 95% confidence interval = 0.48-0.92). The T allele of rs2229717 was less in patients with a low hepatitis B virus-DNA level compared to the control group (odds ratio = 0.49, 95% confidence interval = 0.25-0.97) and TT genotype of rs2229717 had a significant correlation with hepatitis B surface antigen level (p = 0.0195). Further gene-gene interaction analysis showed that subjects carrying the rs10717122 DEL.DEL/DEL.T and rs585800 TT/TA genotypes had a 2.74-fold increased risk of CHB. CONCLUSIONS: The results of the present study suggest that rs10717122, rs585800 and rs2229717 and gene-gene interactions of rs10717122 and rs585800 affect the outcome of CHB infection, at the same time as indicating their usefulness as a predictive and diagnostic biomarker of CHB infection.

Six-Transmembrane Epithelial Antigen of the Prostate 3 Deficiency in Hepatocytes Protects the Liver Against Ischemia-Reperfusion Injury by Suppressing Transforming Growth Factor-ß-Activated Kinase 1.

BACKGROUND AND AIMS: Hepatic ischemia-reperfusion (I/R) injury remains a major challenge affecting the morbidity and mortality of liver transplantation. Effective strategies to improve liver function after hepatic I/R injury are limited. Six-transmembrane epithelial antigen of the prostate 3 (Steap3), a key regulator of iron uptake, was reported to be involved in immunity and apoptotic processes in various cell types. However, the role of Steap3 in hepatic I/R-induced liver damage remains largely unclear. APPROACH AND RESULTS: In the present study, we found that Steap3 expression was significantly up-regulated in liver tissue from mice subjected to hepatic I/R surgery and primary hepatocytes challenged with hypoxia/reoxygenation insult. Subsequently, global Steap3 knockout (Steap3-KO) mice, hepatocyte-specific Steap3 transgenic (Steap3-HTG) mice, and their corresponding controls were subjected to partial hepatic warm I/R injury. Hepatic histology, the inflammatory response, and apoptosis were monitored to assess liver damage. The molecular mechanisms of Steap3 function were explored in vivo and in vitro. The results demonstrated that, compared with control mice, Steap3-KO mice exhibited alleviated liver damage after hepatic I/R injury, as shown by smaller necrotic areas, lower serum transaminase levels, decreased apoptosis rates, and reduced inflammatory cell infiltration, whereas Steap3-HTG mice had the opposite phenotype. Further molecular experiments showed that Steap3 deficiency could inhibit transforming growth factor-ß-activated kinase 1 (TAK1) activation and downstream c-Jun N-terminal kinase (JNK) and p38 signaling during hepatic I/R injury. CONCLUSIONS: Steap3 is a mediator of hepatic I/R injury that functions by regulating inflammatory responses as well as apoptosis through TAK1-dependent activation of the JNK/p38 pathways. Targeting hepatocytes, Steap3 may be a promising approach to protect the liver against I/R injury.

Synthesis and cytotoxic activity of chalcone analogues containing a thieno[2,3-d]pyrimidin-2-yl group as the A-ring or B-ring.

Many natural or synthetic chalcones have potential anti-tumor activity. Here, we synthesized two series of chalcone analogues containing a thieno[2,3-d]pyrimidin-2-yl group and evaluated for their cytotoxic activity towards cultured human lung cancer A549 and colorectal HCT-116 cells. Among them, compound 8d was the most cytotoxic against HCT-116 cells, with an IC50 value of 2.65 µM. Analyses of the phenotypic changes induced by this compound found a dose-dependent accumulation of HCT-116 cells in sub-G1 phase, indicating that compound 8d might induce apoptosis. Furthermore, we found that 8d triggered mitochondrial membrane potential depolarization, promoted reactive oxygen species formation in HCT-116 cells, and increased the percentage of early and late apoptotic cells. Finally, immunoblotting indicated that 8d increased PARP-1 and caspases 3, 7 and 9 cleavage. These data suggest that compound 8d induces apoptosis via the mitochondrial death pathway.

A Methylthio-Functionalized-MOF Photocatalyst with High Performance for Visible-Light-Driven H2 Evolution.

Recently, the emergence of photoactive metal-organic frameworks (MOFs) has given great prospects for their applications as photocatalytic materials in visible-light-driven hydrogen evolution. Herein, a highly photoactive visible-light-driven material for H2 evolution was prepared by introducing methylthio terephthalate into a MOF lattice via solvent-assisted ligand-exchange method. Accordingly, a first methylthio-functionalized porous MOF decorated with Pt co-catalyst for efficient photocatalytic H2 evolution was achieved, which exhibited a high quantum yield (8.90 %) at 420 nm by use sacrificial triethanolamine. This hybrid material exhibited perfect H2 production rate as high as 3814.0 µmol g-1 h-1 , which even is one order of magnitude higher than that of the state-of-the-art Pt/MOF photocatalyst derived from aminoterephthalate.

Synthesis and antitumor activity evaluation of quinazoline derivatives bearing piperazine-1-carbodithioate moiety at C4-position.

A series of quinazoline derivatives bearing piperazine-1-carbodithioate moiety at the C4-position were synthesized using piperidine and 1-bromo-3-chloropropane as starting materials via eight steps. Final compounds 8a-q and 9a-i were evaluated for their antiproliferative activity against human lung cancer A549, breast adenocarcinoma MCF-7, and colorectal cancer HCT-116 cell lines. The results showed that fourteen of twenty-six final compounds inhibited the proliferation of three cancer cell lines with IC50 values less than 10µM. When treated with a representative compound 8n, HCT-116 cells were arrested at G0/G1 phase of the cell cycle. This provided a clue to further investigation of the mechanism of action.

Synthesis and antiproliferative evaluation of piperazine-1-carbothiohydrazide derivatives of indolin-2-one.

By varying the substituents (R(1)) at the indolin-2-one scaffold, a series of indolin-2-one derivatives bearing 4-phenylpiperazine-1-carbothiohydrazide moiety at the C3-position were synthesized and evaluated for their antiproliferative activity against three human cancer cell lines. We further selected the 5-chloroindolin-2-one moiety for the extension to another series of compounds by varying the substituents (R(2)) at the phenyl group connected with the piperazine ring. Among all the compounds synthesized, 6d and 6l were most potent with IC50 values of 3.59 and 5.58 µM, respectively against A549 lung cancer cells, while 5f and 6l possessed IC50 values of 3.49 and 4.57 µM, respectively against HCT-116 colon cancer cells which were comparable to that of Sunitinib, an indolin-2-one derivative in cancer therapy.

2-(5-Fluoro-2,3-dioxoindolin-1-yl)ethyl 4-methyl-piperazine-1-carbodithio-ate.

In the title compound, C(16)H(18)FN(3)O(2)S(2), the methyl-piperazine ring adopts a chair conformation, while the (2,3-dioxoindolin-1-yl)ethyl unit is linked to one of the N atoms of the piperazine ring via the carbodithio-ate group. In the crystal, each mol-ecule is linked to its neighbors within the ([Formula: see text]03) plane through weak C-H(methyl-ene)⋯O, C-H(ar-yl)⋯O and C-H(methyl-ene)⋯S inter-actions. Perpendicular to this plane mol-ecules are connected through inter-molecular short N⋯π(pyrrole ring) contacts [N⋯C centroid = 3.232 (2) Å], another set of C-H(methyl-ene)⋯O inter-actions and through short contacts between carbodithio-ate S atoms and the pyrrole rings [C⋯centroid = 3.695 (3), S⋯centroid = 3.403 (2) Å].

5-Methyl-3,3-bis-(4-methyl-piperazin-1-yl)-1-[2-(4-methyl-piperazin-1-yl)eth-yl]indolin-2-one.

In the title compound, C(26)H(43)N(7)O, each piperazine ring adopts a chair conformation. Two 1-methyl-piperazine rings bond to one Csp(3) of the pyrrole ring via the piperazine N atoms, while the third one links to the N atom of the indolin-2-one unit through a flexible ethyl group with an almost syn conformation. In the crystal, mol-ecules are connected through methyl-ene-carbonyl C-H⋯O inter-actions into an infinite chain along the c axis. The almost parallel arrays are stacked, forming a three-dimensional framework.

5-Methyl-3,3-bis-(morpholin-4-yl)-1-[2-(morpholin-4-yl)eth-yl]-2,3-dihydro-1H-indol-2-one.

In the title compound, C(23)H(34)N(4)O(4), the morpholine rings adopt chair conformations. The N atom of the indol-2-one group is linked to the N atom of one morpholine ring through a flexible ethyl group with an almost cif conformation. In the crystal, molecules are linked by C-H⋯O interactions into infinite chains along the c direction. The almost parallel infinite chains are further inter-connected via other sets of C-H⋯O inter-actions, forming a three-dimensional framework.

Interaction analysis of FADS2 gene variants with chronic hepatitis B infection in Chinese patients.

The risk of chronic hepatitis B (CHB) infection is often affected by polyunsaturated fatty acids (PUFAs) metabolism which is strongly influenced by single nucleotide polymorphisms (SNPs) within the PUFA metabolic pathway. Given this, we designed this study to determine the relationship between specific polymorphisms within fatty acid desaturase 2 (FADS2), a key enzyme in PUFA metabolism, and CHB infection. We completed this evaluation using a case-control study comprising 230 CHB patients and 234 unrelated healthy controls in which the genetic relationships between three previously identified SNPs, isolated via mass spectrometry, and CHB infection. Our data revealed that none of these three SNPs (rs174568, rs174601, and rs2727270) were significantly associated with susceptibility to CHB infection when compared to healthy controls. However, when we stratified our cohort by sex, male subjects with the TC genotype for FADS2 exhibited a decreased risk for CHB infection (OR = 0.62, 95%CI = 0.39-0.96; OR = 0.64, 95%CI = 0.41-1.00; OR = 0.57, 95%CI = 0.36-0.90). Furthermore, age stratification revealed that both the T allele and the TC genotypes for each of the three target SNPs were less common in Chinese CHB cases in people younger than 50 years old. Correlation analysis also revealed that there was no statistically significant relationship between these three SNPs and HBV-DNA replication or hepatitis B surface antigen (HBsAg) levels. Thus, our data suggests that rs174568, rs174601, and rs2727270 may affect the CHB outcomes in various age or sex subgroups, suggesting that they may be useful predictive or diagnostic biomarkers of CHB infection in some populations.

A 1,2,3-Triazole Derivative of Quinazoline Exhibits Antitumor Activity by Tethering RNF168 to SQSTM1/P62.

Quinazoline and its derivatives have drawn much attention in the development of potential antitumor agents. Here, we synthesized a series of 1,2,3-triazole derivatives of quinazoline at the C6 position and evaluated for their cytotoxic activity in various human cancer cell lines. We found that compound 5a was the most cytotoxic to HCT-116 cells (IC50, 0.36 µM). Target profiling found that 5a directly binds to both the autophagy-associated protein SQSTM1/P62 and the E3 ligase RNF168, promoting their interaction. Consistently, 5a treatment induces a decrease in RNF168-mediated H2A ubiquitination and compromises homologous recombination-mediated DNA repair, thus increasing the sensitivity of HCT-116 to X-ray radiation. Moreover, 5a suppressed xenografted tumor growth in mice in a dose-dependent manner. Taken together, the 1,2,3-triazole derivative of quinazoline 5a may serve as a novel compound for tumor therapy based on its role in promoting a P62/RNF168 interaction.

5-Fluoro-1-(4-meth-oxy-benz-yl)indoline-2,3-dione.

In the title compound, C(16)H(12)FNO(3), the dihedral angle between the benzene ring and the plane of the indole ring system is 71.60 (6)°. In the crystal, mol-ecules stack along the b axis through π-π inter-actions between the adjacent indole-2,3-dione units with a centroid-centroid distance of 3.649 (3) Å. Inter-molecular C-H⋯O=C and C-H⋯π inter-actions further stabilize the structure, forming a three-dimensional framework.

[Correlation of mRNA and protein expressions of Runx3 gene in papillary thyroid carcinoma].

OBJECTIVE: To explore the mRNA and protein expressions of Runx3 gene in papillary thyroid carcinoma (PTC). METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used to detect the Runx3 mRNA and protein levels in 67 human PTC specimens and their matched adjacent non-cancerous epithelium (NCE). RESULTS: The relative expression value of Runx3 mRNA was 0.31 ± 0.07 in PTC versus 0.92 ± 0.08 in NCE (t = 38.251, P < 0.05). In PTC, it was correlated with the tumor pathological grade and lymph node metastasis (χ(2) = 5.511, 6.492, P < 0.05). The integral optical density value of Runx3 protein confirmed was 1012 ± 221 in PTC versus 1993 ± 199 in NCE (t = 18.413, P < 0.05). In PTC, it was correlated with the tumor TNM stage, pathological grade and lymph node metastasis (χ(2) = 5.550, 9.678, 5.070, P < 0.05). Furthermore there was a distinct correlation between the mRNA and protein expressions of Runx3 gene (χ(2) = 42.699, P < 0.05). CONCLUSION: The mRNA and protein expressions of Runx3 gene in PTC were lower than those in NCE. A lower expression of Runx3 gene may play an important role in the carcinogenesis and progression of PTC.

ASPM promotes homologous recombination-mediated DNA repair by safeguarding BRCA1 stability.

DNA double-strand break (DSB) repair by homologous recombination (HR) is essential for ensuring genome stability. Abnormal spindle-like microcephaly-associated (ASPM) gene encodes a spindle protein that is commonly implicated in primary microcephaly. We found that ASPM is recruited to sites of DNA damage in a PARP2-dependent manner. ASPM interacts with BRCA1 and its E3 ligase HERC2, preventing HERC2 from accessing to BRCA1 and ensuring BRCA1 stability. Inhibition of ASPM expression promotes HERC2-mediated BRCA1 degradation, compromises HR repair efficiency and chromosome stability, and sensitizes cancer cells to ionizing radiation. Moreover, we observed a synergistic effect between ASPM and PARP inhibition in killing cancer cells. This research has uncovered a novel function for ASPM in facilitating HR-mediated repair of DSBs by ensuring BRCA1 stability. ASPM might constitute a promising target for synthetic lethality-based cancer therapy.

Pharmacological Activating Transcription Factor 6 Activation Is Beneficial for Liver Retrieval With ex vivo Normothermic Mechanical Perfusion From Cardiac Dead Donor Rats.

Background: Normothermic machine perfusion (NMP) could be beneficial for organ retrieval from donors after cardiac death (DCD). Activating transcription factor 6 (ATF6) was recently shown to mitigate liver ischemia/reperfusion injury and confer protection. The aims of this study were to assess the implication of ATF6 in liver retrieval from DCD rat livers with NMP and explore the effect of pharmacologic ATF-6 activation on liver retrieval. Methods: The livers from DCD rats were exposed to 30 min of warm ischemia and 8 h cold preservation followed by 2 h NMP with or without an ATF6 activator in the perfusate. Perfusates and livers were harvested to detect ATF6 expression, liver function, and inflammation. Results: DCD livers with NMP were associated with ATF6 overexpression and activation based on IHC and WB (P < 0.05). The ATF6 activator downregulated perfusate aminotransferases, decreased the Suzuki score, downregulated CD68 and MPO based on IHC, induced the expression of cytochrome c in mitochondria and inhibited the expression of cytochrome c in cytoplasm based on WB, reduced TNFα and IL-6 levels based on ELISA, decreased levels of MDA, GSSG and ATP, and increased SOD activity and GSH levels in the perfused livers (P < 0.05). Conclusion: ATF6 is important for liver retrieval, and an exogenous ATF6 activator accelerates liver retrieval from DCD rats in an ex vivo NMP model.

2-(2,3-Dioxoindolin-1-yl)ethyl 4-(4-nitro-phen-yl)piperazine-1-carbodithio-ate.

In the title compound, C(21)H(20)N(4)O(4)S(2, )the piperazine ring adopts a chair conformation. The 1-ethyl-indoline-2,3-dione system links to one N atom of the piperazine ring via a carbodithio-ate group. The indoline-2,3-dione ring and the nitro-benzene ring subtend adihedral angle of 37.27 (7)°. In the crystal structure, weak C-H⋯O and π-π stacking inter-actions [centroid-centroid distances = 3.534 (5) and 3.797 (5) Å] may help to establish the packing.

3,3-Dichloro-1-(chloro-meth-yl)indolin-2-one.

In the title compound, C(9)H(6)Cl(3)NO, the pyrrole ring is almost coplanar with the benzene ring [dihedral angle = 1.90 (9)°], while the Cl-C-N-C torsion angle is 98.78 (17)°. In the crystal, pairs of mol-ecules are inter-connected by pairs of Cl⋯Cl inter-actions [3.564 (5) Å], forming dimers, which are further peripherally connected through inter-molecular C-H⋯O=C and π-π inter-actions [centroid-centroid distances = 4.134 (7), 4.134 (6) and 4.238 (7) Å], forming a two-dimensional network.

1,1'-(Ethane-1,2-di-yl)bis-(indoline-2,3-dione).

The mol-ecule of the title compound, C(18)H(12)N(2)O(4), is situated on a crystallographic centre of symmetry. The mol-ecule has a zigzag structure, with two parallel symmetry-related indoline-2,3-dione fragments linked by an ethyl-ene group at each N atom. In the crystal, the mol-ecules stack in columns along the b axis. There are two such columns in the structure. The mol-ecules within each column are parallel; however, the mol-ecules in the two columns differ in the respective orientation of the indoline-2,3-dione fragments. In one column, they are approximately parallel to (112), while in the other they are approximately parallel to (12). The inter-planar angle between the indoline-2,3-dione fragments in the two columns is 80.83 (3)°. The mol-ecules within each column are related by mutual displacement of their centres of symmetry, that is (0, ±1/2, ±1/2). The packing between the mol-ecules is provided by weak inter-actions only, viz. C-H⋯O hydrogen bonds and π-π [centroid-centroid distance = 3.8745 (8) Å] and C=O⋯π inter-actions.

Synthesis and cytotoxicity screening of piperazine-1-carbodithioate derivatives of 2-substituted quinazolin-4(3H)-ones.

A new series of piperazine-1-carbodithioate derivatives of 2-substituted quinazolin-4(3H)-ones were synthesized via a five-steps procedure starting from 2-amino-5-methylbenzoic acid. The cytotoxicity of the resulting compounds against A-549 (human lung cancer), HCT-8 (human colon cancer), HepG2 (human liver cancer), and K562 (human myelogenous leukaemia) cell lines was determined by the MTT assay. Preliminary screening results of these compounds are reported.