DFT Insight into a Strain-Release Mechanism in Bicyclo[1.1.0]butanes via Concerted Activation of Central and Lateral C-C Bonds with Rh(III) Catalysis.

Transition-metal-catalyzed, strain-release-driven transformations of "spring-loaded" bicyclo[1.1.0]butanes (BCBs) are considered potent tools in synthetic organic chemistry. Previously proposed strain-release mechanisms involve either the insertion of the central C-C bond of BCBs into a metal-carbon bond, followed by ß-C elimination, or the oxidative addition of the central or lateral C-C bond on the transition metal center, followed by reductive elimination. This study, employing DFT calculations on a Rh(III)-catalyzed model system in a three-component protocol involving oxime ether, BCB ester, and ethyl glyoxylate for constructing diastereoselective quaternary carbon centers, introduces an unusual strain-release mechanism for BCBs. In this mechanism, the catalytic reaction is initiated by the simultaneous cleavage of two C-C bonds (the central and lateral C-C bonds), resulting in the formation of a Rh-carbene intermediate. The new mechanism exhibits a barrier of 21.0 kcal/mol, making it energetically more favorable by 11.1 kcal/mol compared to the previously suggested most favorable pathway. This unusual reaction mode rationalizes experimental observation of the construction of quaternary carbon centers, including the excellent E-selectivity and diastereoselectivity. The newly proposed strain-release mechanism holds promise in advancing our understanding of transition-metal-catalyzed C-C bond activation mechanisms and facilitating the synthesis of transition metal carbene complexes.

G6PD maintains the VSMC synthetic phenotype and accelerates vascular neointimal hyperplasia by inhibiting the VDAC1-Bax-mediated mitochondrial apoptosis pathway.

BACKGROUND: Glucose-6-phosphate dehydrogenase (G6PD) plays an important role in vascular smooth muscle cell (VSMC) phenotypic switching, which is an early pathogenic event in various vascular remodeling diseases (VRDs). However, the underlying mechanism is not fully understood. METHODS: An IP‒LC‒MS/MS assay was conducted to identify new binding partners of G6PD involved in the regulation of VSMC phenotypic switching under platelet-derived growth factor-BB (PDGF-BB) stimulation. Co-IP, GST pull-down, and immunofluorescence colocalization were employed to clarify the interaction between G6PD and voltage-dependent anion-selective channel protein 1 (VDAC1). The molecular mechanisms involved were elucidated by examining the interaction between VDAC1 and apoptosis-related biomarkers, as well as the oligomerization state of VDAC1. RESULTS: The G6PD level was significantly elevated and positively correlated with the synthetic characteristics of VSMCs induced by PDGF-BB. We identified VDAC1 as a novel G6PD-interacting molecule essential for apoptosis. Specifically, the G6PD-NTD region was found to predominantly contribute to this interaction. G6PD promotes VSMC survival and accelerates vascular neointimal hyperplasia by inhibiting VSMC apoptosis. Mechanistically, G6PD interacts with VDAC1 upon stimulation with PDGF-BB. By competing with Bax for VDAC1 binding, G6PD reduces VDAC1 oligomerization and counteracts VDAC1-Bax-mediated apoptosis, thereby accelerating neointimal hyperplasia. CONCLUSION: Our study showed that the G6PD-VDAC1-Bax axis is a vital switch in VSMC apoptosis and is essential for VSMC phenotypic switching and neointimal hyperplasia, providing mechanistic insight into early VRDs.

Preparation of Multifunctional Nano-Molybdenum Disulfide and Its Tribological Properties in Water-Based Cutting Fluids.

In order to meet the advanced requirements of the manufacturing industry, the use of water-based cutting fluids (WCFs) in metal processing is gradually increasing. However, their lubrication performance still needs to be improved considerably. Therefore, new multifunctional molybdenum disulfide nanoparticles (m-MoS2 NPs) were developed to improve the lubricating properties of WCFs. M-MoS2 NPs modified with silver nanoparticles were prepared by an in situ surface modification. The morphology and chemical composition of the m-MoS2 NPs were characterized by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Furthermore, the dispersion and bactericidal properties of m-MoS2 NPs with different weight percents in WCFs were also studied experimentally. The effect of m-MoS2 NPs concentration on friction properties and their friction mechanism were investigated in this research. The results revealed that the prepared m-MoS2 NPs were all nanoscale particles with a layered structure. The dispersion and bactericidal properties of m-MoS2 NPs in WCFs were better than those of MoS2 NPs. The best dispersion and bactericidal properties were observed with 1 wt % MoS2 NPs, as well as friction reduction and antiwear properties. During friction, the two friction surfaces were in the boundary lubrication state,and the prepared m-MoS2 NPs entered the friction contact zone along with the WCFs. A friction chemical reaction film rich in MoS2 and Ag NPs was formed on the friction surface to fill and repair the worn surface, exerting a good lubrication effect.

Catalytic Mechanism of Pyridoxal 5'-Phosphate-Dependent Aminodeoxychorismate Lyase: A Computational QM/MM Study.

Aminodeoxychorismate lyase (ADCL) is a kind of pyridoxal-5'-phosphate (PLP)-dependent enzyme that catalyzes the conversion of 4-amino-4-deoxychorismate (ADC) to p-aminobenzoate (PABA), which is a key step for the biosynthesis of folate. To illuminate the reaction details at the atomistic level, an enzyme-substrate reactant model has been constructed, and QM/MM calculations have been performed. Our calculation results reveal that the overall catalytic cycle contains 11 elementary steps, which can be described by three stages, including the transamination reaction of PLP, the release of pyruvate and aromatization of ADC, and the recovery to the initial aldimine. During the reaction, a series of intramolecular proton transfer are involved, which are the key for the C-N bond formation and cleavage as well as the aromatization of the ADC ring. In addition to forming the Schiff base with the pocket residue Lys251 and substrate in the internal aldimine and the external aldimine, respectively, the coenzyme PLP also plays a critical role in the intramolecular proton transfer by employing its hydroxyl oxygen anion and phosphate group. These findings may provide useful information for further understanding the catalytic mechanism of other PLP-dependent enzymes.

Exploring the Substrate-Assisted Dehydration of Chorismate Catalyzed by Dehydratase MqnA from QM/MM Calculations: The Role of Pocket Residues and the Hydrolysis Mechanism of N17D Mutant.

MqnA is the first enzyme on the futalosine pathway to menaquinone, which catalyzes the dehydration of chorismate to yield 3-enolpyruvyl-benzoate (3-EPB). MqnA is also the only chorismate dehydratase known so far. In this work, based on the recently determined crystal structures, we constructed the enzyme-substrate complex models and conducted quantum mechanics/molecular mechanics (QM/MM) calculations to elucidate the reaction details of MqnA and the critical roles of pocket residues. The calculation results confirm that the MqnA-catalyzed dehydration of chorismate follows the substrate-assisted E1cb mechanism, in which the enol carboxylate in the side chain of the substrate is responsible for deprotonating the C3 of chorismate. This proton transfer process is much slower than C4-OH departure. Calculations on different mutants reveal that S86 and N17 are important for anchoring the enol carboxylate of the substrate in a favorable conformation to extract the C3-proton. The strong H-bonds formed between the enol carboxylate of chorismate and S86/N17 play a key role in stabilizing the reaction intermediate. Consistent with the experimental observations, our calculations demonstrate that the MqnA N17D mutant also shows hydrolase activity and the typical enzyme-catalyzed hydrolysis mechanism is elucidated. The protonated D17 is responsible for saturating the methylene group of chorismate to start the hydrolysis reaction. The orientation of the carboxyl group of D17 is key in determining MqnA to be a dehydratase or hydrolase.

Saxagliptin reduces the injury of Alzheimer's disease cell model by down-regulating the expression of miR-483-5p.

This study aimed to investigate the effect of saxagliptin on the injury of Alzheimer's disease (AD) cell model and its possible mechanism. SK-N-SH cells were cultured in vitro and divided into CON group, AD group, AD+L-SAX group, AD+M-SAX group, AD+H-SAX group, AD+anti-miR-NC group, AD+anti-miR-483-5p group, AD+SAX+miR-NC group and AD+SAX+miR-483-5p group. Then the levels of MDA, SOD and GSH-Px in each group were detected by ELISA method; cell apoptosis was detected by flow cytometry; the protein expression levels of Bax and Bcl-2 were detected by Western Blot; the expression level of miR-483-5p was detected by RT-qPCR. Compared with the control group, MDA content, apoptosis rate, and the expression of Bax protein and miR-483-5p increased in the AD group (P<0.05), while the activity of SOD and GSH-Px and the expression of Bcl-2 protein decreased (P<0.05). Compared with the AD group, MDA content, apoptosis rate, and the expression of Bax protein and miR-483-5p decreased in the AD+L-SAX group, AD+M-SAX group and AD+H-SAX group (P<0.05), while the activity of SOD and GSH-Px and the expression of Bcl-2 protein increased (P<0.05). Compared with AD+anti-miR-NC group, MDA content, apoptosis rate, and the expression of Bax protein and miR-483-5p decreased in the AD+anti-miR-483-5p group (P<0.05), while the activity of SOD and GSH-Px and the expression of Bcl-2 protein increased (P<0.05). Compared with AD+SAX+miR-NC group, MDA content, apoptosis rate, and the expression of Bax protein and miR-483-5p increased in the AD+SAX+miR-483-5p group (P<0.05), while the activity of SOD and GSH-Px and the expression of Bcl-2 protein decreased (P<0.05). Saxagliptin may reduce the injury of Alzheimer's disease cell model by down-regulating the expression of miR-483-5p.

[Analysis of Revision Content and Evaluation Attentions on Guidance for Registration of Metallic Bone Plate Internal Fixation System (Revised in 2021)].

This study briefly introduces the revised content of Guidance for Registration of Metallic Bone Plate Internal Fixation System (Revised in 2021) compared to the original guidance, mainly including the principles of dividing registration unit, main performance indicators of standard specification, physical and mechanical performance research, and clinical evaluation. At the same time, in order to provide some references for the registration of metallic bone plate internal fixation system, this study analyzes the main concerns in the review process of these products based on the accumulation of experience combining with the current review requirements.

CircPCBP2 promotes the stemness and chemoresistance of DLBCL via targeting miR-33a/b to disinhibit PD-L1.

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoid malignancy with a high relapse rate of up to 40%. The prognosis of the disease needs improvement and requires a understanding of its molecular mechanism. We investigated the mechanisms of DLBCL development and its sensitivity to chemotherapy by focusing on circPCBP2/miR-33a/b/PD-L1 axis. Human DLBCL specimens and cultured cancer cell lines were used. Features of circPCBP2 were systematically characterized through Sanger sequencing, Actinomycin D, RNase R treatment, and FISH. The expression levels of circPCBP2, miR-33a/b, PD-L1, stemness-related markers, ERK/AKT and JAK2/STAT3 signaling were measured using qRT-PCR, western blotting, and immunohistochemistry. Stemness of DLBCL cells was assessed through spheroid formation assay and flow cytometry. Cell viability and apoptosis upon cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) treatment were determined using MTT assay and flow cytometry, respectively. Interactions of circPCBP2-miR-33a/b and miR-33a/b-PD-L1 were validated using dual luciferase activity assay and RNA-RIP. Nude mouse xenograft model was used to assess the function of circPCBP2 in DLBCL growth in vivo. circPCBP2 was upregulated in human DLBCL specimens and cultured DLBCL cells while miR-33a/b was reduced. Knockdown of circPCBP2 or miR-33a/b overexpression inhibited the stemness of DLBCL cells and promoted cancer cell apoptosis upon CHOP treatment. circPCBP2 directly bound with miR-33a/b while miR-33a/b targeted PD-L1 3'-UTR. circPCBP2 disinhibited PD-L1 signaling via sponging miR-33a/b. miR-33a/b inhibitor and activating PD-L1 reversed the effects of circPCBP2 knockdown and miR-33a/b mimics, respectively. circPBCP2 knockdown restrained DLBCL growth in vivo and potentiated the anti-tumor effects of CHOP. In conclusion, circPCBP2 enhances DLBCL cell stemness but suppresses its sensitivity to CHOP via sponging miR-33a/b to disinhibit PD-L1 expression. circPCBP2/miR-33a/b/PD-L1 axis could serve as a diagnosis marker or therapeutic target for DLBCL.

Dioxygen Activation and Nδ,Nε-Dihydroxylation Mechanism Involved in the Formation of N-Nitrosourea Pharmacophore in Streptozotocin Catalyzed by Nonheme Diiron Enzyme SznF.

SznF is a nonheme diiron-dependent enzyme that catalyzes the critical N-nitrosation involved in the formation of the N-nitrosourea moiety in the pancreatic cancer drug streptozotocin. The N-nitrosation contains two successive N-hydroxylation and N-nitrosation steps, which are carried out by two separate active sites, namely, the central domain and cupin domain. Recently, the crystal structure of SznF was obtained, and the central domain was proved to contain a diiron cofactor to catalyze the N-hydroxylation. In this work, to gain insights into the O2 activation and the successive N-hydroxylation mechanism, on the basis of the high-resolution crystal structure, the enzyme-substrate complex models were constructed, and a series of combined QM/MM calculations were performed. Based on our calculations, the activation of O2 starts from the diiron(II,III)-superoxo (S) to generate the diiron(IV)-oxo species (Q) via a diiron(III,III)-peroxo (P)-like transition state or unstable intermediate (P'), and species P' can be described as a hybridization of diiron(IV)-oxo species and diiron(III,III)-peroxo (P) owing to the long distances of Fe1-Fe2 (4.22 Å) and O1-O2 (1.89 Å), which is different from those of other nonheme diiron enzymes. In the following hydroxylation of Nδ and Nε, the Nδ-hydroxylation was confirmed to occur first, agreeing with the experimental observations. Because the diiron(IV)-oxo species (Q) is responsible for hydroxylation, the reaction follows the H-abstraction/OH rebound mechanism, and the first abstraction occurs on the Nδ-H rather than Nε-H, which may be attributed to the different orientation of Fe(IV)-oxo relative to N-H as well as the bond dissociation enthalpies of two N-H bonds. The hydroxylation of N-methyl-L-arginine does not employ the diiron(III,III)-hydroperoxo (P″) to trigger the electrophilic attack of the guanidine to directly form the N-O bond, as previously suggested. In addition, our calculations also revealed that the direct attack of the Fe(IV)═O unit to the Nδ of the substrate corresponds to a higher barrier than that in the H-abstraction/OH rebound mechanism. These results may provide useful information for understanding the formation of the di-hydroxylation intermediate involved in the biosynthesis of N-nitrosation.

Clinical features of Trousseau's syndrome with multiple acute ischemic strokes.

BACKGROUND: Trousseau's syndrome or migrating thrombophlebitis can cause venous or arterial thrombosis; however, multiple acute ischemic strokes (MAIS) caused by Trousseau's syndrome are rare. The aim of this study was to analyse the clinical features of Trousseau's syndrome with MAIS and to improve the awareness and the knowledge of this disease. METHODS: Clinical data from fifteen patients who were diagnosed as Trousseau's syndrome with MAIS in Rizhao People's Hospital from January 2017 to April 2020 were collected and analysed. The clinical data included the following: patients' basic information (including gender, age, underlying diseases, and tumour stage), laboratory results, imaging features, treatment regimens, and short-term prognoses were collected. RESULTS: The mean age was 65.5 years, with thirteen males and two females. Most patients (11/15) had a history of smoking and (or) drinking. The average score of NIHSS was 2.13. 6 of the 15 patients first presented with ischemic stroke and then found the primary tumour. Most common types of primary tumour was lung cancer (11/15), and other types of primary tumour were gastric adenocarcinoma, renal cell carcinoma, oesophageal adenosquamous carcinoma, and cholangiocarcinoma (one in each). All the 15 patients showed different levels of increase of D-dimer. The increase in CRP appears in 10 of the 15 patients. Various tumour markers were increased in the 15 patients, especially for CYFRA-211, all the patients of which were higher than normal. All of the 15 patients had multiple vascular territory lesions in DWI, and most lesions were near the cortex areas. Only 4 of the 15 patients (26.7%) occurred with peripheral venous thrombosis. Thirteen patients were given low molecular heparin for anticoagulant therapy, of which 9 patients were improved in short-term while 4 patients were not. CONCLUSION: Trousseau's syndrome with MAIS was associated with old-age male, smoking and (or) drinking history, low NIHSS score, increased D-dimer, CRP and tumour markers, and lesions near the cortex areas with multiple vascular territories in DWI. Patients with these features should be alert of malignant tumour. Most common types of primary tumour were lung cancer. Treatment with low molecular heparin may be effective in short term.

Organotypic Culture of Testicular Tissue from Infant Boys with Cryptorchidism.

Organotypic culture of human fetal testis has achieved fertilization-competent spermatids followed by blastocysts development. This study focuses on whether the organotypic culture of testicular tissue from infant boys with cryptorchidism could support the development of spermatogonia and somatic cells. Frozen-thawed tissues were cultured in two different media, with or without retinoic acid (RA), for 60 days and evaluated by tissue morphology and immunostaining using germ and somatic cell markers. During the 60-day culture, spermatocytes stained by boule-like RNA-binding protein (BOLL) were induced in biopsies cultured with RA. Increased AR expression (p < 0.001) and decreased AMH expression (p < 0.001) in Sertoli cells indicated advancement of Sertoli cell maturity. An increased number of SOX9-positive Sertoli cells (p < 0.05) was observed, while the percentage of tubules with spermatogonia was reduced (p < 0.001). More tubules with alpha-smooth muscle actin (ACTA, peritubular myoid cells (PTMCs) marker) were observed in an RA-absent medium (p = 0.02). CYP17A1/STAR-positive Leydig cells demonstrated sustained steroidogenic function. Our culture conditions support the initiation of spermatocytes and enhanced maturation of Sertoli cells and PTMCs within infant testicular tissues. This study may be a basis for future studies focusing on maintaining and increasing the number of spermatogonia and identifying different factors and hormones, further advancing in vitro spermatogenesis.

LncRNA LUADT1 is Upregulated in Mantle Cell Lymphoma and Modulates TRIM11 by Sponging miR-24-3p to Inhibit Cell Apoptosis.

The microRNA MiR-24-3p suppresses cancer progression by targeting TRIM11. The long noncoding RNA LUADT1 has been reported to promote lung adenocarcinoma proliferation. We found LUADT1 may form base pairing with miR-24-3p. This study aimed to explore the interactions among LUADT1, miR-24-3p, and TRIM11 in mantle cell lymphoma (MCL). Our study recruited 40 MCL patients and 40 healthy volunteers. Tumor tissues were collected from 40 newly diagnosed MCL patients and embedded in paraffin wax. B lymphocytes were isolated from all tissue samples by using CD19+ magnetic beads and DETACHaBEAD CD19. Human MCL cell line Grante-519 and JeKo-1 were transfected with LUADT1 and TRIM11 expression vectors, microRNA mimics or inhibitors. Then, quantitative polymerase chain reaction and Western blot were used to detect the level of relative messenger RNA and protein expression, respectively. Flow cytometry was performed to detect the apoptosis rate. LUADT1 and miR-24-3p were upregulated while TRIM11 was downregulated in MCL both in tissues and cell lines compared with hyperplastic lymphadenitis and peripheral lymphocyte cells. Bioinformatics analysis showed that LUADT1 may bind miR-24-3p, which can target TRIM11. Correlation analysis showed that LUADT1 was not significantly correlated with miR-24-3p. However, it was positively and significantly correlated with TRIM11. In MCL cells, LUADT1 overexpression led to upregulated TRIM11, whereas miR-24-3p overexpression led to downregulated TRIM11. Cell apoptosis analysis showed that LU-ADT1, miR-24-3p inhibitor and TRIM11 overexpression led to decreased apoptotic rate of MCL cells, whereas miR-24-3p overexpression led to an increased apoptotic rate of MCL cells. In addition, miR-24-3p overexpression attenuated the effects of LUADT1 overexpression. Therefore, LUADT1 was upregulated in MCL and could modulate TRIM11 by sponging miR-24-3p to inhibit cancer cell apoptosis.

Mesenchymal stromal cells can repair radiation-induced pulmonary fibrosis via a DKK-1-mediated Wnt/ß-catenin pathway.

Pulmonary injury occurring after thoracic radiotherapy is a main factor limiting the curative effect of radiotherapy. Robust activation of the Wnt signalling pathway induced by ionizing radiation stress plays a critical role in epithelial-mesenchymal transition (EMT) in irradiated type II alveolar epithelial cells and in the proliferation of pulmonary fibroblasts, which contributes to the formation of fibrotic lesions in irradiated lungs. The pathogenesis of radiation-induced pulmonary fibrosis could be restricted by systemic delivery of human adipose-derived mesenchymal stromal cells (Ad-MSCs), as evidenced by the inhibitory effects of Ad-MSCs on EMT in irradiated type II alveolar epithelial cells. The purpose of this study is to observe the effects of mesenchymal stromal cells (MSCs) on repairing fibrosis caused by radiation. We used western blotting and real-time PCR to observe the expression of DKK-1 in MSCs of different origins and passages. After the successful establishment of a radiation-induced lung injury model, we investigated the potency of the supernatant from stromal cells to reduce pro-fibrotic events, including EMT and fibroblast activation. To study the mechanism, we evaluated the levels of active ß-catenin, TCF4 and the target genes Snail, Twist and c-Myc. After the injection of Ad-MSCs into mice via the tail vein, proteins related to EMT, fibroblasts and Wnt/ß-catenin signalling were investigated. The TGF-ß and IL-10 protein concentrations in peripheral blood were measured by ELISA. Ad-MSC-derived supernatant effectively reversed the decrease in E-cadherin expression and inhibited the increase in vimentin expression induced by ionizing radiation in epithelial cells and suppressed the expression of α-SMA, a mediator of fibroblast proliferation. The canonical Wnt pathway may be activated by irradiation but the nuclear localization of active ß-catenin was reduced in the presence of the supernatant from Ad-MSCs. In addition, the expression of target genes involved in EMT was downregulated. Additionally, when DKK-1 in the supernatant was neutralized, all these effects were reversed. Changes in the levels of proteins related to EMT and fibroblast activation, as well as those of active ß-catenin and TCF4, were similar in vivo and in vitro. The serum level of the immunosuppressive factor IL-10 was increased after radiation and was further enhanced after Ad-MSC interference for one month. In conclusion, Ad-MSCs medium can contain DKK-1 and inhibit the induction of EMT via Wnt/ß-catenin signalling in vitro and in vivo.

Infrared Responsive Choline Phosphate Lipids for Synergistic Cancer Therapy.

Choline phosphate lipids have been designed and developed as new-generation zwitterionic nanocarriers with excellent biocompatibility and bioorthogonality to provide a more programmable performance for cancer therapy. However, there is a lack of spatiotemporal and reversible control for drug release at target tumor cells, which can lead to severe adverse effects to normal tissue and discounted treatment outcome. Here, light-inducible Lip-cRGDfk/ICG/Dox liposomes were developed for synergistic cancer therapy. ICG can effectively convert light energy into selective heating in a local environment upon laser irradiation, thus inducing thermal ablation of tumor cells, and further reversibly trigger the spatiotemporal release of anticancer drugs (Dox) at tumor cells due to the conformation transformation of CP lipids to synergistically kill tumor cells. That Lip-cRGDfk/ICG/Dox exhibited a significant improvement for breast cancer therapy in vitro and in vivo is also demonstrated, thus it can serve as an efficient platform to noninvasively and spatiotemporally control the activation of cytotoxicity at tumor cells for precision cancer therapy.

ADAM10 mediates ectopic proximal tubule development and renal fibrosis through Notch signalling.

Disturbed intrauterine development increases the risk of renal disease. Various studies have reported that Notch signalling plays a significant role in kidney development and kidney diseases. A disintegrin and metalloproteinase domain 10 (ADAM10), an upstream protease of the Notch pathway, is also reportedly involved in renal fibrosis. However, how ADAM10 interacts with the Notch pathway and causes renal fibrosis is not fully understood. In this study, using a prenatal chlorpyrifos (CPF) exposure mouse model, we investigated the role of the ADAM10/Notch axis in kidney development and fibrosis. We found that prenatal CPF-exposure mice presented overexpression of Adam10, Notch1 and Notch2, and led to premature depletion of Six2+ nephron progenitors and ectopic formation of proximal tubules (PTs) in the embryonic kidney. These abnormal phenotypic changes persisted in mature kidneys due to the continuous activation of ADAM10/Notch and showed aggravated renal fibrosis in adults. Finally, both ADAM10 and NOTCH2 expression were positively correlated with the degree of renal interstitial fibrosis in IgA nephropathy patients, and increased ADAM10 expression was negatively correlated with decreased kidney function evaluated by serum creatinine, cystatin C, and estimated glomerular filtration rate. Regression analysis also indicated that ADAM10 expression was an independent risk factor for fibrosis in IgAN. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

CircKDM4C upregulates P53 by sponging hsa-let-7b-5p to induce ferroptosis in acute myeloid leukemia.

To investigate the role of circKDM4C in acute myeloid leukemia (AML), the expression of circKDM4C, hsa-let-7b-5p, and P53 was measured by qRT-RCR. AML cell lines(K-562 and HL-60) were transfected correspondingly and investigated for cell proliferation, migration, and invasion abilities by CCK-8, colony formation, transwell, and wound healing assays, respectively. The levels of P53, ACSL4, PTGS2, GPX4, and FTH1 in the K-562, and HL-60 cells were measured by western blotting. Also, circKDM4C mediated regulation of ferroptosis was studied. The Phen Green SK probe and confocal laser scanning microscope were used to assess the cellular iron levels. The reactive oxygen species levels were analyzed by fluorescence-activated cell sorting using the C11-BODIPY probe. Bioinformatics analysis predicted the putative binding sites among circKDM4C, hsa-let-7b-5p, and P53. These were verified using the dual-luciferase reporter assay, RNA pull-down, and RNA immunoprecipitation assays. Finally, in vitro findings were also verified in vivo using the nude mice. CircKDM4C was significantly down-regulated in AML patients. The overexpression of circKDM4C in AML cell lines inhibited the cell proliferation, migration, invasion, and promoted ferroptosis. We found that circKDM4C acts as a sponge of hsa-let-7b-5p and thereby regulates p53 which is a target gene of hsa-let-7b-5p. Also, the expression of circKDM4C and hsa-let-7b-5p are negatively correlated, while circKDM4C and p53 are positively correlated to AML patients. Moreover, we found that circKDM4C induces ferroptosis by sponging hsa-let-7b-5p which upregulates the expression of P53. This work emphasizes the role of circKDM4C in AML patients, which could be explored for the therapeutic role.

Glioblastoma Stem Cell-Derived Exosomes Enhance Stemness and Tumorigenicity of Glioma Cells by Transferring Notch1 Protein.

Exosomes contain plenty of bioactive information, playing an important role in intercellular communication by transfer their bioactive molecular contents to recipient cells. Glioblastoma stem cells (GSCs) and non-GSC glioma cells coexist in GBM microenvironment; GSC-released exosomes contain intracellular signaling molecules, which may affect the biological phenotypes of recipient cells. However, whether GSC exosomes could affect the biological phenotype of non-GSC glioma cells has not yet been defined. To explore whether GSC exosomes could reprogramme non-GSC glioma cells into GSCs and its possible mechanism involved, non-GSC glioma cells were treated with GSCs released exosomes; the potential mechanisms of action were studied with RNA interference, Notch inhibitors and Western blot analysis. The proliferation, neurosphere formation, invasive capacities, and tumorigenicity of non-GSC glioma cells were increased significantly after GSC exosome treatment; Notch1 signaling pathway was activated in GSCs; Notch1 protein was highly enriched in GSC exosomes; Notch1 signaling pathway and stemness-related protein expressions were increased in GSC exosome treated non-GSC glioma cells and these cell generated tumor tissues; Notch1 protein expression in GSCs and their exosomes, and the neurosphere formation of GSCs were decreased by Notch1 RNA interference; Notch1 signaling pathway protein and stemness protein expressions were decreased in GSC exosome treated non-GSC glioma cells by Notch1 RNA interference and Notch inhibitors. The findings in this study indicated that GSC exosomes act as information carriers, mediated non-GSC glioma cell dedifferentiation into GSCs by delivering Notch1 protein through Notch1 signaling activation, and enhanced stemness and tumorigenicity of non-GSC glioma cells.

Theoretical Study of Iron Porphyrin Nitrene: Formation Mechanism, Electronic Nature, and Intermolecular C-H Amination.

The formation mechanism and electronic structures of iron porphyrin nitrene intermediates, as well as the nitrene-mediated intermolecular C-H amination, have been studied by performing DFT and ab initio complete active space self-consistent field (CASSCF) calculations. Compared with that of cobalt porphyrin nitrene and iron porphyrin carbene, the formation of iron porphyrin nitrene shows similar but different characteristics. The common feature is that all their formation is required to undergo the "far" or "close" complexes, but these complexes correspond to different energies relative to their respective reactants (isolated metalloporphyrins and azides), which is considered as one main reason to determine the reaction barriers. The overall free energy barrier for the formation of iron porphyrin nitrene was calculated to be 10.6 kcal/mol on a triplet-state surface, which is lower than those of cobalt porphyrin nitrene and iron porphyrin carbene. The departure of N2 from the close complexes formed by iron porphyrin and tosyl azide is nearly barrierless. For iron porphyrin nitrene, both CASSCF and unrestricted DFT calculations revealed that the triplet and open-shell singlet complexes correspond to very similar energies. The triplet nitrene complex can be described as [(por)(-OCH3)FeII═NTs]- ↔ [(por)(-OCH3)FeIII═N•-Ts]- ↔ [(por)(-OCH3)FeIV═N2-Ts]-, while the oss nitrene complex can be described as [(por)(-OCH3)FeIII-N•-Ts]-. Since the N atom bears a similar spin density as in cobalt porphyrin nitrene, the iron porphyrin nitrene exhibits similar activity in hydrogen abstraction. In addition, the intermolecular C-H amination catalyzed by iron porphyrin nitrene follows the hydrogen atom abstraction/radical recombination mechanism with a free energy barrier of 7.1 kcal/mol on the triplet-state surface. In general, the medium reactivity and easily prepared characteristic of iron porphyrin nitrene makes it a potential catalyst for C-H amination.

Effect of TrkB-PLC/IP3 pathway on intestinal inflammatory factors and enterocyte apoptosis in mice with colitis.

In this study, we aimed to explore the effect of TrkB-PLC/IP3 pathway on intestinal inflammatory factors and enterocyte apoptosis in mice with colitis. The mouse model of ulcerative colitis was established by medication, and 40 SPF C57BL/6J mice (8 weeks old) were randomly divided into normal group (healthy mice, n = 10), control group (sham-operated mice, n = 10), model group (model mice without any treatment, n = 10), and K252a group (model mice treated with 100 µmol/kg TrkB-PLC/IP3 pathway inhibitor for 5 days before clysis, n = 10). The results showed that mice in the model and K252a groups, as compared with normal and control groups, had no significant changes in the levels and protein expressions of serum tumor necrosis factor-α (TNF-α) and TNF-γ in the colon tissues (P>0.05), and had a significant increase in disease activity index, colon mucosa damage index, tissue damage index scores, and levels and protein expressions of serum interleukin-4 (IL-4) and IL-8, but had a significant decrease in the level and protein expression of serum IL-10 (P<0.05). Mice in the model and K252a groups showed blocked enterocyte cycle progression, elevated apoptosis ratio, and significantly increased mRNA and protein expressions of Caspase3, Bax, FasL, and Fas, but significantly reduced mRNA and protein expressions of p-TrkB, PLC-γ1, IP3, and Bcl-2 (P<0.05). Moreover, intestinal inflammation and apoptosis induced by colitis in the K252a group became more aggravated by inhibiting the activity of TrkB-PLC/IP3 pathway. In conclusion, inhibition of TrkB-PLC/IP3 pathway can increase the expression of intestinal inflammatory factors and promote enterocyte apoptosis in mice with colitis.

Curcumin derivative L6H4 inhibits proliferation and invasion of gastric cancer cell line BGC-823.

Curcumin and its chalcone derivatives have well-known, explicit biological antitumor properties, such as instance antiproliferative and apoptotic effects via multiple molecular targets. In this study, we investigated the anticancer activity of curcumin derivative L6H4 (curcumin L6H4) on gastric cancer cells. Inhibitory effects of curcumin L6H4 on gastric cancer cells (BGC-823) were studied by the diphenyltetrazolium (MTT) assay, and cell apoptosis was detected by Annexin-V/propidium iodide (PI) staining and then analyzed by flow cytometry. A mouse xenotransplant gastric tumor model was established to detect the role of curcumin L6H4 in vivo. The apoptosis-related proteins p53, p21, Bax, and Bcl-2 in BGC-823 cells and mouse xenotransplant models treated with curcumin L6H4 were determined by Western blot analysis. Curcumin L6H4 can significantly inhibit the proliferation and induce the apoptosis of BGC-823 cells, thus enhancing the expression levels of p53, p21, Bax, and Bcl-2 noticeably in vivo and in vitro. Meanwhile, curcumin L6H4 can remarkably suppress the growth of tumor cells in animal models. These results suggest that curcumin derivative L6H4 has potent of antitumor properties in vitro or in vivo.