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The diterpene synthase AfAS was identified from Aspergillus fumigatiaffinis. Its amino acid sequence and—according to a structural model—active site architecture are highly similar to those of the fusicocca‐2,10(14)‐diene synthase PaFS, but AfAS produces a structurally much more complex diterpene with a novel 6–5–5–5 tetracyclic skeleton called asperfumene. The cyclisation mechanism of AfAS was elucidated through isotopic labelling experiments and DFT calculations. The reaction cascade proceeds in its initial steps through similar intermediates as for the PaFS cascade, but then diverges through an unusual vicinal deprotonation‐reprotonation process that triggers a skeletal rearrangement at the entrance to the steps leading to the unique asperfumene skeleton. The structural model revealed only one major difference between the active sites: The PaFS residue F65 is substituted by I65 in AfAS. Intriguingly, site‐directed mutagenesis experiments with both diterpene synthases revealed that position 65 serves as a bidirectional functional switch for the biosynthesis of tetracyclic asperfumene versus structurally less complex diterpenes. [ABSTRACT FROM AUTHOR]

The title reaction of ynamides of type (I), (IV), and (VI) with benzylic azides (II) offers a highly regioselective access to 2-aminoindoles (III) and (V). Indolylmethyl derived azides (VI) and (IX) give 3-amino-β-carbolines. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to explore the role and mechanism of ferroptosis in SiO 2 -induced cardiac injury using a mouse model., Methods: Male C57BL/6 mice were intratracheally instilled with SiO 2 to create a silicosis model. Ferrostatin-1 (Fer-1) and deferoxamine (DFO) were used to suppress ferroptosis. Serum biomarkers, oxidative stress markers, histopathology, iron content, and the expression of ferroptosis-related proteins were assessed., Results: SiO 2 altered serum cardiac injury biomarkers, oxidative stress, iron accumulation, and ferroptosis markers in myocardial tissue. Fer-1 and DFO reduced lipid peroxidation and iron overload, and alleviated SiO 2 -induced mitochondrial damage and myocardial injury. SiO 2 inhibited Nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream antioxidant genes, while Fer-1 more potently reactivated Nrf2 compared to DFO., Conclusion: Iron overload-induced ferroptosis contributes to SiO 2 -induced cardiac injury. Targeting ferroptosis by reducing iron accumulation or inhibiting lipid peroxidation protects against SiO 2 cardiotoxicity, potentially via modulation of the Nrf2 pathway., (Copyright © 2024 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.)

Chiral ketones and their derivatives are useful synthetic intermediates for the synthesis of biologically active natural products and medicinally relevant molecules. Nevertheless, general and broadly applicable methods for enantioenriched acyclic α,α-disubstituted ketones, especially α,α-diarylketones, remain largely underdeveloped, owing to the easy racemization. Here, we report a visible light photoactivation and phosphoric acid-catalyzed alkyne-carbonyl metathesis/transfer hydrogenation one-pot reaction using arylalkyne, benzoquinone, and Hantzsch ester for the expeditious synthesis of α,α-diarylketones with excellent yields and enantioselectivities. In the reaction, three chemical bonds, including C═O, C─C, and C─H, are formed, providing a de novo synthesis reaction for chiral α,α-diarylketones. Moreover, this protocol provides a convenient and practical method to synthesize or modify complex bioactive molecules, including efficient routes to florylpicoxamid and BRL-15572 analogs. Computational mechanistic studies revealed that C-H/π interactions, π-π interaction, and the substituents of Hantzsch ester all play crucial roles in the stereocontrol of the reaction.

Objective: To explore the effects of hydroxyacyl-CoA dehydrogenase alpha subunit (HADHA) on the migration and invasion of HTR-8/SVneo cells, a human trophoblast cell line, and its potential mechanism of action., Methods: Immunofluorescence staining was done to evaluate the expression levels of HADHA in samples of normal villi and recurrent spontaneous abortion (RSA) villi at 6-8 weeks. Lentiviral infection system was used to construct stable HTR-8/SVneo cell lines with HADHA overexpression and knockdown. Western blot, qRT-PCR, Wound-healing assay, and Transwell assay were used to determine the effect of HADHA on the migration and invasion of HTR-8/SVneo cells and the expression of relevant genes. Transcriptome sequencing and bioinformatics analysis were done to screen for the potential target genes and signaling pathways regulated by HADHA. The specific molecular mechanism of how HADHA regulates the migration and invasion of HTR-8/SVneo cells was examined by adding the inhibitor of protein kinase B (PKB/AKT)., Results: HADHA was highly expressed in extravillous trophoblasts (EVT) of RSA villus samples as compared with samples from the normal control group. In HTR-8/SVneo cells overexpressing HADHA , the expression levels of migration and invasion-related genes, including HLA - G , MMP 2, MMP 9, and NCAD , were decreased ( P <0.01, P <0.05), and the migration and invasion abilities of HTR-8/SVneo cells were weakened ( P <0.05). HADHA knockdown increased the expression levels of HLA - G , MMP 2, MMP 9, and NCAD ( P <0.01, P <0.05), and promoted the migration and invasion of HTR-8/SVneo cells ( P <0.05). In addition, HADHA overexpression decreased the phosphorylation levels of PI3K and AKT ( P <0.05) and inhibited the PI3K/AKT signaling pathway. HADHA knockdown activated the PI3K/AKT signaling pathway. When MK-2206, an AKT inhibitor, was added to stable HTR-8/SVneo cell lines with HADHA knockdown, the migration and invasion of the cells were significantly reduced., Conclusion: HADHA inhibits the migration and invasion of HTR-8/SVneo cells by inhibiting the PI3K/AKT signaling pathway., (Copyright© by Editorial Board of Journal of Sichuan University (Medical Sciences).)

Preeclampsia is a pregnancy complication which threatens the survival of mothers and fetuses. It originates from abnormal placentation, especially insufficient fusion of the cytotrophoblast cells to form the syncytiotrophoblast. In this study, we found that THBS1, a matricellular protein that mediates cell-to-cell and cell-to-matrix interactions, is downregulated during the fusion of primary cytotrophoblast and BeWo cells, but upregulated in the placenta of pregnancies complicated by preeclampsia. Also, THBS1 was observed to interact with CD36, a membrane signal receptor and activator of the cAMP signaling pathway, to regulate the fusion of cytotrophoblast cells. Overexpression of THBS1 inhibited the cAMP signaling pathway and reduced the BeWo cells fusion ratio, while the effects of THBS1 were abolished by a CD36-blocking antibody. Our results suggest that THBS1 signals through a CD36-mediated cAMP pathway to regulate syncytialization of the cytotrophoblast cells, and that its upregulation impairs placental formation to cause preeclampsia. Thus, THBS1 can serve as a therapeutic target regarding the mitigation of abnormal syncytialization and preeclampsia., (© 2020 Chongqing Medical University. Production and hosting by Elsevier B.V.)

An efficient zinc(II)-catalyzed alkyne oxidation/C-H functionalization sequence was developed, thus leading to highly site-selective synthesis of a variety of isoquinolones and β-carbolines. Importantly, in contrast to the well-established gold-catalyzed intermolecular alkyne oxidation, over-oxidation can be completely suppressed in this system and the reaction most likely proceeds by a Friedel-Crafts-type pathway. Mechanistic studies and theoretical calculations are described., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Aim: To investigate whether a virus constitutively expressing active Akt is useful to prevent cirrhosis induced by carbon tetrachloride (CCl4)., Methods: Using cre-loxp technique, we created an Ad-myr-HA-Akt virus, in which Akt is labeled by a HA tag and its expression is driven by myr promoter. Further, through measuring enzyme levels and histological structure, we determined the efficacy of this Ad-myr-HA-Akt virus in inhibiting the development of cirrhosis induced by CCl4 in rats. Lastly, using western blotting, we examined the expression levels and/or phosphorylation status of Akt, apoptotic mediators, endothelial nitric oxide synthase (eNOS), and markers for hepatic stellate cells activation to understand the underlying mechanisms of protective role of this virus., Results: The Ad-myr-HA-Akt virus was confirmed using polymerase chain reaction amplification of inserted Akt gene and sequencing for full length of inserted fragment, which was consistent with the sequence reported in the GenBank. The concentrations of Ad-myr-HA-Akt and adenoviral enhanced green fluorescent protein (Ad-EGFP) virus used in the current study were 5.5 × 10(11) vp/mL. The portal vein diameter, peak velocity of blood flow, portal blood flow and congestion index were significantly increased in untreated, saline and Ad-EGFP cirrhosis groups when compared to normal control after the virus was introduced to animal through tail veil injection. In contrast, these parameters in the Akt cirrhosis group were comparable to normal control group. Compared to the normal control, the liver function (Alanine aminotransferase, Aspartate aminotransferase and Albumin) was significantly impaired in the untreated, saline and Ad-EGFP cirrhosis groups. The Akt cirrhosis group showed significant improvement of liver function when compared to the untreated, saline and Ad-EGFP cirrhosis groups. The Hyp level and portal vein pressure in Akt cirrhosis groups were also significantly lower than other cirrhosis groups. The results of HE and Van Gieson staining indicated that Akt group has better preservation of histological structure and less fibrosis than other cirrhosis groups. The percentage of apoptotic cell was greatly less in Akt cirrhosis group than in other cirrhosis groups. Akt group showed positive HA tag and an increased level of phosphorylated Akt as well as decreased levels of Fas. In contrast, Caspase-3 and Caspase-9 levels in Akt group were significantly lower than other cirrhosis groups. Noticeable decrease of DR5 and α-SMA and increase of phosphorylated eNOS were observed in the Akt group when compared to other cirrhosis groups. The NO level in liver was significantly higher in Akt group than other cirrhosis groups, which was consistent with the level of phosphorylated eNOS in these groups., Conclusion: This study suggest that Ad-myr-HA-Akt virus is a useful tool to prevent CCl4-induced cirrhosis in rat model and Akt pathway may be a therapeutic target for human cirrhosis.

Objective: To summarize clinical application of the distal island muscle flap of the gastrocnemius muscle for repairing the defects around knee and within the upper 2/3 of lower leg., Methods: 18 patients with defects around knee and within the upper 2/3 of lower leg, were treated with the distal island muscle flap of the gastrocnemius muscle, including 12 cases with medial muscle head and 6 cases with lateral muscle head. The muscular flaps were covered with meshed split-thickness skin grafts. The wound at donor sites were closed directly., Results: All the skin grafts and muscle flaps survived with superior infection at the wound edge in two cases. The patients were followed up for 8 months to 4.8 years with satisfactory cosmetic and functional results., Conclusions: The distal island muscle flap of the gastrocnemius muscle has a reliable blood supply, long pedicle and suitable thickness. It is an ideal method for repairing the defects around knee and within the upper 2/3 of lower leg.

Objective: To evaluate clinical result of the micro-decompression procedure for lumbar spinal stenosis., Methods: From September 2001 to May 2006,87 patients (male 60, female 27) with lumbar spinal stenosis underwent micro-decompression. The age of patients were from 43 to 80 years with an average of 51 years. Among them,2 cases with spinal stenosis occured in L(3,4), 47 in L(4,5), 38 in L5S1., Results: All patients were followed up for 18-48 months with an average of 26 months. The results were excellent in 52 cases, good in 28, poor in 7, according to Macnab of back leg pain standard. The rate of excellent and good was 92%., Conclusion: Operative treatment for lumbar spinal stenosis is focused at the areas causing symptomatic neural root compression rather than prophylactic decompression at areas of nonsymptomatic disease. The micro-decompression procedures are more likely to be well tolerated by older patients.

Objective: To explore the relationship between the genetic polymorphism of fibronectin (FN) (4 genetic locus) and pneumoconiosis., Methods: 128 male I-period pneumoconiosis were selected as cases who were examined with radiography and diagnosed by the Pneumoconiosis Diagnosis Expert Panel, based on the Chinese National Diagnosis Criteria of Pneumoconiosis (GBZ 70 - 2002). According to 1:1 paired matching method, 128 dust exposure workers were selected as control who were exposed to same dust as cases. The difference of age and cumulative length of service between case and control was not over five years and two years, respectively. 5 ml peripheral venous blood was drawn and anticoagulated with 2% EDTA. The polymorphisms of FN (MspI, TaqIb, HindIII, HaeIIIb) were detected, using the method of polymerase chain restriction fragment length polymorphism (PCR-RFLP) techniques and PCR., Results: The frequencies of FN Msp I (CC) in cases and control groups were 10.9% and 3.9%, respectively. The difference was significant (P < 0.05). The frequencies of FN (MspI) C allele were 41.8% and 31.2% in case and control, and the difference between cases and controls was significant (P < 0.05). The frequencies of FN HaeIIIb (AA) genotype in cases (24.2%) was higher than that in control groups (17.9%), OR = 5.0 (95% CI: 4.840 approximately 24.210). The frequencies of FN (HaeIIIb) A allele were 51.9% and 42.2% in case and control, and the difference was significant (P < 0.05). The difference of TaqIb and HindIII genotype between cases and controls were not significant (P > 0.05)., Conclusion: The risk of suffering from pneumoconiosis increases in workers carrying FN (MspICC or HaeIIIb AA) genotype after exposure to dust. Workers both carrying FN (HaeIIIb AA) and (MspICC) genotypes are more susceptible to pneumoconiosis. The relationship between genetic polymorphism of FN (TaqIIb, HindIII) and pneumoconiosis has not been found.

Objective: To investigate the expression of calcyclin in pancreatic carcinoma and its relation to the patients' prognosis., Methods: Human pancreatic carcinoma tissue microarray was constructed, which contained 63 cores of 3 normal adult pancreas tissues, 6 chronic pancreatitis tissues, 51 pancreatic carcinoma tissues and 3 islet cell carcinoma tissues. Immunohistochemistry was performed to detect the expression of calcyclin in these tissues, and the relationship between calcyclin and the clinicopatholoical features of pancreatic carcinoma was analyzed., Results: The positivity rate of calcyclin in the pancreatic carcinoma tissue was 76.5% (39/51), and calcyclin staining was more intense in the malignant cells than in the benign cells (P=0.007), suggesting a correlation between calcyclin expression and pancreatic carcinoma. No evidence was found for an association of calcyclin expression with the variables including the patients' gender, age at surgery, and tumor grade. Weak staining for calcyclin was noted in chronic pancreatitis tissues., Conclusion: Calcyclin expression is related to the pancreatic carcinomas and up-regulation of calcyclin expression is possibly an early event in pancreatic and pragression of development cancer.