Deacetylation of Septin4 by SIRT2 (Silent Mating Type Information Regulation 2 Homolog-2) Mitigates Damaging of Hypertensive Nephropathy.

BACKGROUND: Hypertension can lead to podocyte damage and subsequent apoptosis, eventually resulting in glomerulosclerosis. Although alleviating podocyte apoptosis has clinical significance for the treatment of hypertensive nephropathy, an effective therapeutic target has not yet been identified. The function of septin4, a proapoptotic protein and an important marker of organ damage, is regulated by post-translational modification. However, the exact role of septin4 in regulating podocyte apoptosis and its connection to hypertensive renal damage remains unclear. METHODS: We investigated the function and mechanism of septin4 in hypertensive nephropathy to discover a theoretical basis for targeted treatment. Mouse models including Rosa 26 (Gt(ROSA)26Sor)-SIRT2 (silent mating type information regulation 2 homolog-2)-Flag-TG (transgenic) (SIRT2-TG) mice SIRT2-knockout, and septin4-K174Q mutant mice, combined with proteomic and acetyl proteomics analysis, followed by multiple molecular biological methodologies, were used to demonstrate mechanisms of SIRT2-mediated deacetylation of septin4-K174 in hypertensive nephropathy. RESULTS: Using transgenic septin4-K174Q mutant mice treated with the antioxidant Tempol, we found that hyperacetylation of the K174 site of septin4 exacerbates Ang II (angiotensin II)- induced hypertensive renal injury resulting from oxidative stress. Proteomics and Western blotting assays indicated that septin4-K174Q activates the cleaved-PARP1 (poly [ADP-ribose] polymerase family, member 1)-cleaved-caspase3 pathway. In septin4-knockdown human renal podocytes, septin4-K174R, which mimics deacetylation at K174, rescues podocyte apoptosis induced by Ang II. Immunoprecipitation and mass spectrometry analyses identified SIRT2 as a deacetylase that interacts with the septin4 GTPase domain and deacetylates septin4-K174. In Sirt2-deficient mice and SIRT2-knockdown renal podocytes, septin4-K174 remains hyperacetylated and exacerbates hypertensive renal injury. By contrast, in Rosa26-Sirt2-Flag (SIRT2-TG) mice and SIRT2-knockdown renal podocytes reexpressing wild-type SIRT2, septin4-K174 is hypoacetylated and mitigates hypertensive renal injury. CONCLUSIONS: Septin4, when activated through acetylation of K174 (K174Q), promotes hypertensive renal injury. Septin4-K174R, which mimics deacetylation by SIRT2, inhibits the cleaved-PARP1-cleaved-caspase3 pathway. Septin4-K174R acts as a renal protective factor, mitigating Ang II-induced hypertensive renal injury. These findings indicate that septin4-K174 is a potential therapeutic target for the treatment of hypertensive renal injury.

Global, regional, and national burden of brain and central nervous system cancers for males from 1990 to 2021 and its predicted level in the next 25 years.

BACKGROUND: A study of the global burden of cerebral and central nervous system (CNS) cancers from the Global Burden of Diseases (GBD) indicates that these cancers significantly contribute to morbidity and mortality internationally. To fully understand the global impact of CNS cancer, expanded research efforts are essential. We analyzed the temporal trend of the disease burden from 1990 to 2021 and made projections for the expected burden from 2020 through 2044. METHODS: We tapped into GBD 2021 Study data to evaluate CNS cancer incidence and trends among males. Prevalence was assessed with DisMod-MR, trends via cluster analysis, and Estimated Annual Percentage Change (EAPC) calculated via linear regression. Forecasts for 2022-2044 used APC and BAPC models, with a P-value < 0.05 considered significant. Analyses relied on R software 4.0.2. RESULTS: In 2021, males experienced between 148,118 and 232,469 new brain and CNS cancer cases, indicating increased global burden from 1990 to 2021. An observed link between the prevalence's EAPCs and Human Development Indices (HDIs) suggests higher incidence in more developed regions. Projections using the APC model suggest rising numbers of cases and losses in Disability-Adjusted Life Years (DALYs) from 2020 to 2044, while Age-Standardized Rates (ASRs) are expected to decrease overall. CONCLUSIONS: In summary, a higher Socio-Demographic Index (SDI) correlates with better outcomes for CNS cancer due to early medical interventions in regions with strong healthcare systems. This demonstrates the need for equitable healthcare policies that focus on improving diagnostic capabilities and professional training to enhance survival rates universally.

Programmed death of cardiomyocytes in cardiovascular disease and new therapeutic approaches.

Cardiovascular diseases (CVDs) have a complex pathogenesis and pose a major threat to human health. Cardiomyocytes have a low regenerative capacity, and their death is a key factor in the morbidity and mortality of many CVDs. Cardiomyocyte death can be regulated by specific signaling pathways known as programmed cell death (PCD), including apoptosis, necroptosis, autophagy, pyroptosis, and ferroptosis, etc. Abnormalities in PCD can lead to the development of a variety of cardiovascular diseases, and there are also molecular-level interconnections between different PCD pathways under the same cardiovascular disease model. Currently, the link between programmed cell death in cardiomyocytes and cardiovascular disease is not fully understood. This review describes the molecular mechanisms of programmed death and the impact of cardiomyocyte death on cardiovascular disease development. Emphasis is placed on a summary of drugs and potential therapeutic approaches that can be used to treat cardiovascular disease by targeting and blocking programmed cell death in cardiomyocytes.

MAPbI3perovskite photodetectors for high-performance optical wireless communication.

High-sensitivity and fast-response photodetectors (PDs) are vital part of optical wireless communication (OWC) system. In this work, we develop an organic-inorganic hybrid perovskite material (MAPbI3) based p-i-n structured PD. By optimizing the precursor solution concertation, the PD showed a high responsivity of 0.98 A W-1, a fast response timetrise/tfallof 12/12.5 µs, a specific detectivity of 2.62 × 1013Jones, and the f-3dBof 24 kHz under the 532 nm laser and -0.2 V bias voltage. Furthermore, we designed an OWC system based on the prepared PD. With the baud rate of 19200 bps, the system exhibits a bit error rate less than 10-6, and it can realize 9.63 m long-distance communication and quick transmission applications such as strings, texts, photos, and audios. Our work demonstrates the great application potential of perovskite PDs in the field of optical communication.

Therapeutic potential of melatonin in the intervertebral disc degeneration through inhibiting the ferroptosis of nucleus pulpous cells.

Ferroptosis, a novel type of cell death mediated by the iron-dependent lipid peroxidation, contributes to the pathogenesis of the intervertebral disc degeneration (IDD). Increasing evidence demonstrated that melatonin (MLT) displayed the therapeutic potential to prevent the development of IDD. Current mechanistic study aims to explore whether the downregulation of ferroptosis contributes to the therapeutic capability of MLT in IDD. Current studies demonstrated that conditioned medium (CM) from the lipopolysaccharide (LPS)-stimulated macrophages caused a series of changes about IDD, including increased intracellular oxidative stress (increased reactive oxygen species and malondialdehyde levels, but decreased glutathione levels), upregulated expression of inflammation-associated factors (IL-1ß, COX-2 and iNOS), increased expression of key matrix catabolic molecules (MMP-13, ADAMTS4 and ADAMTS5), reduced the expression of major matrix anabolic molecules (COL2A1 and ACAN), and increased ferroptosis (downregulated GPX4 and SLC7A11 levels, but upregulated ACSL4 and LPCAT3 levels) in nucleus pulposus (NP) cells. MLT could alleviate CM-induced NP cell injury in a dose-dependent manner. Moreover, the data substantiated that intercellular iron overload was involved in CM-induced ferroptosis in NP cells, and MLT treatment alleviated intercellular iron overload and protected NP cells against ferroptosis, and those protective effects of MLT in NP cells further attenuated with erastin and enhanced with ferrostatin-1(Fer-1). This study demonstrated that CM from the LPS-stimulated RAW264.7 macrophages promoted the NP cell injury. MLT alleviated the CM-induced NP cell injury partly through inhibiting ferroptosis. The findings support the role of ferroptosis in the pathogenesis of IDD, and suggest that MLT may serve as a potential therapeutic approach for clinical treatment of IDD.

Light Chain Q166C Mutation Permits One-step Site Specific Conjugation on Monoclonal Antibodies.

Engineered cysteines are frequently used for site-specific conjugation in antibody-drug conjugate (ADC) development. When cysteine-engineered mAbs are produced in the cell culture process, the sulfhydryl groups on the engineered cysteines are mostly in an oxidized form. The oxidized cysteines require multiple steps (such as reduction, reoxidation, and buffer exchanges) to reactivate for bioconjugation, which complicates the ADC production process and reduces yields. In this study, we identified a Q166C mutation in the light chain that allows the presence of free sulfhydryl groups during cell culture and purification process. This mutation is in the constant region and away from sites involved in antigen binding or Fc-mediated functions. The free sulfhydryl reacts readily with maleimide in a mild solution at a high conjugation rate. This is only the second such site reported (the first one is Q124C in the light chain). Using the Q166C mutation, we conjugated an anti-angiopoietin-2 (Ang-2) peptide on bevacizumab, an anti-vascular endothelial growth factor (VEGF) antibody, to construct a peptide antibody conjugate, Ava-Plus, which could block two pro-angiogenic factors simultaneously. Ava-Plus showed high affinity for both VEGF and Ang-2 and demonstrated higher activity than bevacizumab in in vitro cell migration and in vivo mouse xenograft models.

The role of glycolytic metabolic pathways in cardiovascular disease and potential therapeutic approaches.

Cardiovascular disease (CVD) is a major threat to human health, accounting for 46% of non-communicable disease deaths. Glycolysis is a conserved and rigorous biological process that breaks down glucose into pyruvate, and its primary function is to provide the body with the energy and intermediate products needed for life activities. The non-glycolytic actions of enzymes associated with the glycolytic pathway have long been found to be associated with the development of CVD, typically exemplified by metabolic remodeling in heart failure, which is a condition in which the heart exhibits a rapid adaptive response to hypoxic and hypoxic conditions, occurring early in the course of heart failure. It is mainly characterized by a decrease in oxidative phosphorylation and a rise in the glycolytic pathway, and the rise in glycolysis is considered a hallmark of metabolic remodeling. In addition to this, the glycolytic metabolic pathway is the main source of energy for cardiomyocytes during ischemia-reperfusion. Not only that, the auxiliary pathways of glycolysis, such as the polyol pathway, hexosamine pathway, and pentose phosphate pathway, are also closely related to CVD. Therefore, targeting glycolysis is very attractive for therapeutic intervention in CVD. However, the relationship between glycolytic pathway and CVD is very complex, and some preclinical studies have confirmed that targeting glycolysis does have a certain degree of efficacy, but its specific role in the development of CVD has yet to be explored. This article aims to summarize the current knowledge regarding the glycolytic pathway and its key enzymes (including hexokinase (HK), phosphoglucose isomerase (PGI), phosphofructokinase-1 (PFK1), aldolase (Aldolase), phosphoglycerate metatase (PGAM), enolase (ENO) pyruvate kinase (PKM) lactate dehydrogenase (LDH)) for their role in cardiovascular diseases (e.g., heart failure, myocardial infarction, atherosclerosis) and possible emerging therapeutic targets.

Effectiveness of internet-based self-management interventions on pulmonary function in patients with chronic obstructive pulmonary disease: A systematic review and meta-analysis.

AIM: To investigate the effectiveness of internet-based self-management interventions on pulmonary function in patients with chronic obstructive pulmonary disease (COPD). DESIGN: Systematic review and meta-analysis. DATA SOURCES: Eight electronic databases including PubMed, Web of Science, Cochrane library, Embase, CINAHL, China National Knowledge Infrastructure, Wangfang and Weipu databases were systematically searched from inception of the database to January 10, 2022. METHODS: Statistical analysis was performed using Review Manager 5.4 and results were reported as mean difference (MD) or standard mean difference (SMD) with 95% confidence intervals (CI). Outcomes were the forced expiratory volume in 1 second (FEV1), forced volume capacity (FVC) and percent of FEV1/FVC. The Cochrane Risk of Bias Tool was used to assess the risk of bias of included studies. The study protocol was not registered. RESULTS: Eight randomized controlled trials (RCTs) including 476 participants met the inclusion criteria and were included in meta-analysis. It was found that internet-based self-management interventions showed a significant improvement in FVC(L), while FEV1 (%), FEV1 (L), FEV1/FVC (%) and FVC (%) did not significantly improve. CONCLUSIONS: Internet-based self-management interventions were effective in improving pulmonary function in patients with COPD, caution should be exercised in interpreting the results. RCTs of higher quality are needed in the future to further demonstrate the effectiveness of the intervention. RELEVANCE TO CLINICAL PRACTICE: It provides evidence for internet-based self-management interventions in improving pulmonary function in patients with COPD. IMPACT: The results suggested that internet-based self-management interventions could improve the pulmonary function in people with COPD. This study provides a promising alternative method for patients with COPD who have difficulty seeking face-to-face self-management interventions, and the intervention can be applied in clinical settings. PATIENT OR PUBLIC CONTRIBUTION: No Patient or Public Contribution.

The spatial effect of industrial transfer on carbon emissions under firm location decision:A carbon neutrality perspective.

Climate change is a global concern. The goal of carbon neutrality and emission peak is a challenge for China and other developing countries. The carbon reduction policy for carbon neutrality and industrial transfer policy will be a research hotspot on carbon emissions. This study analyzed the spatial impact mechanism of industrial transfer on carbon emissions, especially the role of firm location decision and carbon reduction policy. Based on the dynamic deviation-share model, the industrial transfer products of 30 provinces in China during the "Twelfth Five-Year Plan" and "Thirteenth Five-Year Plan" periods were measured. The spatially weighted interaction model based on improved parameters was then utilized to explore the spatial effect of industrial transfer and carbon reduction policy on regional carbon emissions. The results show that the restrictive carbon reduction policy through centrifugal effect lead to the location shift of manufacturing firms. Industrial transfer and carbon emissions are significantly related. The restrictive carbon reduction policy has significant spatial emission reduction effect. The carbon reduction policy and industrial transfer level of different region comprehensively were the key factors affecting China's carbon neutral goal. The findings have implications for optimizing the scheme of carbon emission reduction tasks allocation between regions.

Effects of home-based telehealth on the physical condition and psychological status of patients with chronic obstructive pulmonary disease: A systematic review and meta-analysis.

AIMS: This systematic review and meta-analysis aimed to evaluate the effects of home-based telehealth compared with usual care on six-minute walking distance (6MWD), health-related quality of life, anxiety and depression in patients with chronic obstructive pulmonary disease. METHODS: We identified randomized controlled trials through a systematic multidatabase search. Titles and abstracts were assessed for relevance. Two authors independently extracted data and assessed the risk of bias and quality of evidence. Meta-analyses were conducted using Review Manager and Stata. RESULTS: We included 32 randomized controlled trials (n = 5232). Devices used for home-based telehealth interventions included telephones, videos, and combined devices. The quality of the evidence was downgraded due to high risk of bias, imprecision, and inconsistency. Home-based telehealth significantly increased 6MWD by 35 m (SD = 30.42) and reduced symptom burden by 3 points (SD = -2.30) on the COPD assessment test compared with usual care. However, no significant differences in anxiety and depression were noted between the home-based telehealth group and the standard care group. In subgroup analysis, home-based telehealth significantly improved 6MWD and health status after 6-12 months and >12 months. CONCLUSION: Low quality evidence showed that home-based telehealth interventions reduce symptom burden and increase walking distance to a clinically meaningful extent in patients with COPD. However, no effects on depression and anxiety were observed.

Auricular Acupressure for Improving Sleep Quality in Patients With Lung Cancer: A Systematic Review and Meta-analysis.

This meta-analysis was conducted to systematically evaluate the efficacy and safety of auricular acupressure on sleep quality in patients with lung cancer. Nine articles with a total of 802 patients were retrieved after searching on 11 electronic databases. Results of the meta-analysis showed that auricular acupressure improved sleep score (standard mean difference: -0.80, 95% confidence intervals: -1.30 to -0.30, P = .002) and reduced sleep disturbance rate (risk ratio: 0.65, 95% confidence intervals: 0.51-0.84, P = .001) and sleep medicine usage (risk ratio: 0.26, 95% confidence intervals: 0.11-0.65, P = .004) significantly. Our review suggests that auricular acupressure is effective and relatively safe in improving sleep quality among patients with lung cancer.

The impact of edema and fiber crossing on diffusion MRI metrics assessed in an ex vivo nerve phantom: Multi-tensor model vs. diffusion orientation distribution function.

Diffusion tensor imaging (DTI) has been employed for over 2 decades to noninvasively quantify central nervous system diseases/injuries. However, DTI is an inadequate simplification of diffusion modeling in the presence of coexisting inflammation, edema and crossing nerve fibers. We employed a tissue phantom using fixed mouse trigeminal nerves coated with various amounts of agarose gel to mimic crossing fibers in the presence of vasogenic edema. Diffusivity measures derived by DTI and diffusion basis spectrum imaging (DBSI) were compared at increasing levels of simulated edema and degrees of fiber crossing. Furthermore, we assessed the ability of DBSI, diffusion kurtosis imaging (DKI), generalized q-sampling imaging (GQI), q-ball imaging (QBI) and neurite orientation dispersion and density imaging to resolve fiber crossing, in reference to the gold standard angles measured from structural images. DTI-computed diffusivities and fractional anisotropy were significantly confounded by gel-mimicked edema and crossing fibers. Conversely, DBSI calculated accurate diffusivities of individual fibers regardless of the extent of simulated edema and degrees of fiber crossing angles. Additionally, DBSI accurately and consistently estimated crossing angles in various conditions of gel-mimicked edema when compared with the gold standard (r2 = 0.92, P = 1.9 × 10-9 , bias = 3.9°). Small crossing angles and edema significantly impact the diffusion orientation distribution function, making DKI, GQI and QBI less accurate in detecting and estimating fiber crossing angles. Lastly, we used diffusion tensor ellipsoids to demonstrate that DBSI resolves the confounds of edema and crossing fibers in the peritumoral edema region from a patient with lung cancer metastasis, while DTI failed. In summary, DBSI is able to separate two crossing fibers and accurately recover their diffusivities in a complex environment characterized by increasing crossing angles and amounts of gel-mimicked edema. DBSI also indicated better angular resolution compared with DKI, QBI and GQI.

MRI-based assessment of function and dysfunction in myelinated axons.

Repetitive electrical activity produces microstructural alteration in myelinated axons, which may afford the opportunity to noninvasively monitor function of myelinated fibers in peripheral nervous system (PNS)/CNS pathways. Microstructural changes were assessed via two different magnetic-resonance-based approaches: diffusion fMRI and dynamic T2 spectroscopy in the ex vivo perfused bullfrog sciatic nerves. Using this robust, classical model as a platform for testing, we demonstrate that noninvasive diffusion fMRI, based on standard diffusion tensor imaging (DTI), can clearly localize the sites of axonal conduction blockage as might be encountered in neurotrauma or other lesion types. It is also shown that the diffusion fMRI response is graded in proportion to the total number of electrical impulses carried through a given locus. Dynamic T2 spectroscopy of the perfused frog nerves point to an electrical-activity-induced redistribution of tissue water and myelin structural changes. Diffusion basis spectrum imaging (DBSI) reveals a reversible shift of tissue water into a restricted isotropic diffusion signal component. Submyelinic vacuoles are observed in electron-microscopy images of tissue fixed during electrical stimulation. A slowing of the compound action potential conduction velocity accompanies repetitive electrical activity. Correlations between electrophysiology and MRI parameters during and immediately after stimulation are presented. Potential mechanisms and interpretations of these results are discussed.

Identification of Biomarkers for Osteosarcoma Based on Integration Strategy.

BACKGROUND Osteosarcoma (OS) is the most common primary malignant tumor of bone. The identification of novel biomarkers is necessary for the diagnosis and treatment of osteosarcoma. MATERIAL AND METHODS We obtained 11 paired fresh-frozen OS samples and normal controls from patients between September 2015 and February 2017. We used an integration strategy that analyzes next-generation sequencing data by bioinformatics methods based on the pathogenesis of osteosarcoma. RESULTS One susceptibility lncRNA and 7 susceptibility genes regulated by the lncRNA for osteosarcoma were effectively identified, and real-time PCR and clinical index ALP data were used to test their effectiveness. CONCLUSIONS The results showed that the expression levels of the 7 genes were highly consistent in the training and test sample sets, especially between the expression value of the gene ALPL and the plasma detection value of its encoded protein ALP. In particular, both the expression of gene ALPL and the plasma detection values of protein ALP encoded by gene ALPL showed a high degree of consistency among different data types. The identified lncRNA and genes effectively classified the samples proved so that they could be used as potential biomarkers of osteosarcoma. Our strategy may also be helpful for the identification of biomarkers for other diseases.

[Analysis of the Related Risk Factors of Cerebral AVM Hemorrhage and the Relationship Between EPCs and SDF-1 in Brain AVM].

OBJECTIVE: To explore the related risk factors of hemorrhage in human brain cerebral arteriovenous malformations (AVM) and the relationship between endothelial progenitor cells (EPCs) content and stromal cell-derived factor-1 (SDF-1) in different ages. METHODS: A retrospective analysis was conducted on 130 patients with cerebral AVM who underwent surgical treatment from May 2012 to October 2018. Univariate and multivariate logistic analysis was used to investigate the related risk factors of cerebral AVM hemorrhage. Forty paraffin specimens of human brain AVM were harvested from 24 cases of cerebral hemorrhage patients and 16 cases of non-cerebral hemorrhage patients Paraffin samples of cerebral cortex from 8 patients with epilepsy during the same period were selected as control. Positive expression of CD34 and vascular endothelial growth factor receptor 2 (KDR2) in brain tissue samples of both groups were used to identify EPCs. Immunofluorescence double staining was used for KDR2 and CD34 positive localization to determine EPCs localization, and SDF-1 expression detection was performed. RESULTS: The size of brain AVM<3 cm, deep brain AVM and single venous drainage are independent risk factors for cerebral AVM hemorrhage. Immunohistochemical results showed that CD34 and KDR2 were expressed in cerebral AVM group, but not in the control group. Double immunofluorescence staining showed that EPCs mainly existed at the edge of vascular wall, while SDF-1 could co-stain with alpha-smooth muscle actin (α-SMA) positive cells and CD31 positive cells. SDF-1 expression in brain AVM tissue was higher than that in control group. There were significant differences in the number of EPCs among the patients of different ages ( P<0.05). There was no significant difference in EPCs between cerebral hemorrhage group and non-hemorrhage group ( P>0.05). CONCLUSION: Brain AVM (<3 cm), single venous drainage and deep brain AVM are independent risk factors for cerebral AVM hemorrhage. In human brain AVM, EPC appears high level but decrease with age, which may play a role in vascular remodeling in AVM.

Unveiling Secrets of Overcoming the "Heteroatom Problem" in Palladium-Catalyzed Aerobic C-H Functionalization of Heterocycles: A DFT Mechanistic Study.

Directed C-H functionalization of heterocycles through an exocyclic directing group (DG) is challenging due to the interference of the endocyclic heteroatom(s). Recently, the "heteroatom problem" was circumvented with the development of the protection-free Pd-catalyzed aerobic C-H functionalization of heterocycles guided by an exocyclic CONHOMe DG. We herein provide DFT mechanistic insights to facilitate the expansion of the strategy. The transformation proceeds as follows. First, the Pd2(dba)3 precursor interacts with t-BuNC (L, one of the substrates) and O2 to form the L2Pd(II)-η(2)-O2 peroxopalladium(II) species that can selectively oxidize N-methoxy amide (e.g., PyCONHOMe) substrate, giving an active L2Pd(II)X2 (X = PyCONOMe) species and releasing H2O2. After t-BuNC ligand migratory insertion followed by a 1,3-acyl migration and association with another t-BuNC, L2Pd(II)X2 converts to a more stable C-amidinyl L2Pd(II)XX' (X' = PyCON(t-Bu)C═NOMe) species. Finally, L2Pd(II)XX' undergoes C-H activation and C-C reductive elimination, affording the product. The C-H activation is the rate-determining step. The success of the strategy has three origins: (i) the N-methoxy amide DG can be easily oxidized in situ to generate the active L2Pd(II)X2 species via the oxidase pathway, thus preventing the destructive oxygenase pathway leading to stable t-BuNCO or the O-bridged dimeric Pd(II) species. The methoxy group in this amide DG greatly facilitates the oxidase pathway, and the tautomerization of N-methoxy amide to its imidic acid tautomer makes the oxidation of the substrate even easier. (ii) The X group in L2Pd(II)X2 can serve as an internal base to promote the C-H activation via CMD (concerted metalation-deprotonation) mechanism. (iii) The strong coordination ability of t-BuNC substrate/ligand suppresses the conventional cyclopalladation pathway enabled by the coordination of an endocyclic heteroatom to the Pd-center.

Regulation of Intrinsic and Extrinsic Apoptotic Pathways in Osteosarcoma Cells Following Oleandrin Treatment.

Our previous study has reported the anti-tumor effect of oleandrin on osteosarcoma (OS) cells. In the current study, we mainly explored its potential regulation on intrinsic and extrinsic apoptotic pathway in OS cells. Cells apoptosis, reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) were detected using fluorescence staining and flow cytometry. Caspase-3 activity was detected using a commercial kit. The levels of cytoplasmic cytochrome c, mitochondrial cytochrome c, bcl-2, bax, caspase-9, Fas, FasL, caspase-8 and caspase-3 were detected by Western blotting. z-VAD-fmk was applied to block both intrinsic and extrinsic apoptosis pathways, and cells apoptosis was also tested. Furthermore, we used z-LEHD-fmk and Fas blocking antibody to inhibit intrinsic and extrinsic pathways, separately, and the selectivity of oleandrin on these pathways was explored. Results showed that oleandrin induced the apoptosis of OS cells, which was accompanied by an increase in ROS and a decrease in MMP. Furthermore, cytochrome c level was reduced in mitochondria but elevated in the cytoplasm. Caspase-3 activity was enhanced by oleandrin in a concentration- and time-dependent manner. Oleandrin also down-regulated the expression of bcl-2, but up-regulated bax, caspase-9, Fas, FasL, caspase-8 and caspase-3. In addition, the suppression of both apoptotic pathways by z-VAD-fmk greatly reverted the oleandrin-induced apoptosis. Moreover, the suppression of one pathway by a corresponding inhibitor did not affect the regulation of oleandrin on another pathway. Taken together, we concluded that oleandrin induced apoptosis of OS cells via activating both intrinsic and extrinsic apoptotic pathways.

Effect of the CYP2D6 gene polymorphism on postoperative analgesia of tramadol in Han nationality nephrectomy patients.

OBJECTIVE: Tramadol is a synthetic opioid which has analgesic efficacy in the postoperative pain. It is metabolized by polymorphic enzyme cytochrome P450 (CYP2D6). Patients with different CYP2D6 genotypes would have different responses to tramadol in pain relief. The CYP2D6*10 allele is the most common allele in a Chinese population. The aim of this study was to evaluate whether the different CYP2D6*10 genotypes have an effect on the postoperative tramadol analgesia in the Chinese population after elective nephrectomy. METHODS: One hundred and twenty patients after performed elective nephrectomy were enrolled in this study after being approved by the local Ethics Committee. The patients were given patient-controlled analgesia (PCA) which included 10 mg/ml tramadol after receiving a loading dose of 100 mg tramadol and 1 mg granisetron intravenously. Blood samples were collected after induction of anesthesia. The CYP2D6*10 polymorphism was analyzed by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). According to the results, the patients were divided into three groups (CYP2D6*1/*1, n = 33; CYP2D6*1/*10, n = 28; CYP2D6*10/*10, n = 50). The total consumption of tramadol, visual analogue scale (VAS) score, and PCA control times among the three genotype groups for 2, 4, 24, 48, and 72 h after operation were compared. RESULTS: Nine out of 120 patients were dropped out of the study; 111 patients completed the study. The frequency of CYP2D6*10 allele was 57.7%. The demographic data among the three groups were comparable. The consumption of tramadol, patient self-control times of pump, and VAS score in CYP2D6*10/*10 group were significantly higher than that in CYP2D6*1/*1 or CYP2D6*1/*10 group at 2 and 4 h (P < 0.05), while it did not differ between CYP2D6*1/*1 and CYP2D6*1/*10 group (P > 0.05). There was no difference in the incidence of nausea and vomiting among the three groups (P > 0.05). No sever apnea was recorded in these groups. CONCLUSIONS: Different CYP2D6*10 genotypes have an influence on the analgesic effect of tramadol in Han nationality patients after elective nephrectomy.

Catalytic mechanisms of direct pyrrole synthesis via dehydrogenative coupling mediated by PNP-Ir or PNN-Ru pincer complexes: crucial role of proton-transfer shuttles in the PNP-Ir system.

Kempe et al. and Milstein et al. have recently advanced the dehydrogenative coupling methodology to synthesize pyrroles from secondary alcohols (e.g., 3) and ß-amino alcohols (e.g., 4), using PNP-Ir (1) and PNN-Ru (2) pincer complexes, respectively. We herein present a DFT study to characterize the catalytic mechanism of these reactions. After precatalyst activation to give active 1A/2A, the transformation proceeds via four stages: 1A/2A-catalyzed alcohol (3) dehydrogenation to give ketone (11), base-facilitated C-N coupling of 11 and 4 to form an imine-alcohol intermediate (18), base-promoted cyclization of 18, and catalyst regeneration via H2 release from 1R/2R. For alcohol dehydrogenations, the bifunctional double hydrogen-transfer pathway is more favorable than that via ß-hydride elimination. Generally, proton-transfer (H-transfer) shuttles facilitate various H-transfer processes in both systems. Notwithstanding, H-transfer shuttles play a much more crucial role in the PNP-Ir system than in the PNN-Ru system. Without H-transfer shuttles, the key barriers up to 45.9 kcal/mol in PNP-Ir system are too high to be accessible, while the corresponding barriers (<32.0 kcal/mol) in PNN-Ru system are not unreachable. Another significant difference between the two systems is that the addition of alcohol to 1A giving an alkoxo complex is endergonic by 8.1 kcal/mol, whereas the addition to 2A is exergonic by 8.9 kcal/mol. The thermodynamic difference could be the main reason for PNP-Ir system requiring lower catalyst loading than the PNN-Ru system. We discuss how the differences are resulted in terms of electronic and geometric structures of the catalysts and how to use the features in catalyst development.

Mechanistic origins of chemo- and regioselectivity of Ru(II)-catalyzed reactions involving ortho-alkenylarylacetylene, alkyne, and methanol: the crucial role of a chameleon-like intermediate.

M06-DFT computations have been applied to understand four catalytic systems which involved [Ru(Cp*)(MeCN)3]PF6 or [Ru(Tp)(PPh3)(MeCN)2]PF6 as mediator and ortho-alkenylarylacetylene, terminal alkyne, and methanol as reactants. Potentially, the products of these systems could be dihydrobiphenylenes, 1,3-dienyl ether, and naphthalene. Remarkably, each system afforded product selectively. Our computed mechanisms successfully account for the chemo- and regioselectivities of these systems. Furthermore, the study demonstrates that the chameleon-like mono(carbene) intermediates formed via the intermolecular alkyne-alkyne oxidative coupling play a crucial role to complete the reactions. According to their geometric and electronic structures, three resonance structures were introduced to characterize their reactivity properties, which address the features of the classical alkyne-alkyne oxidative coupling intermediates, mono(carbene) species, and electrophilicity of the intermediates, respectively. The reactivity properties lead to three channels isomerizing the intermediates to three isomers. Surprisingly, the bis(carbene) isomers, which are similar to the bis(carbene) intermediates generally considered to be crucial in the neutral RuCp*Cl-catalyzed systems, are accessible but not reactive enough to continue the subsequent reaction steps partially due to aromaticity. The other two isomers continue subsequent reaction steps. These findings may help not only to understand the four specific catalytic reactions but also to advance the [2 + 2 + 2] synthetic methodology.