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BACKGROUND: The gut microbiota plays a critical role in regulating brain function through the microbiome-gut-brain axis (MGBA). Dysbiosis of the gut microbiota is associated with neurological impairment in Traumatic brain injury (TBI) patients. Our previous study found that TBI results in a decrease in the abundance of Prevotella copri (P. copri). P. copri has been shown to have antioxidant effects in various diseases. Meanwhile, guanosine (GUO) is a metabolite of intestinal microbiota that can alleviate oxidative stress after TBI by activating the PI3K/Akt pathway. In this study, we investigated the effect of P. copri transplantation on TBI and its relationship with GUO-PI3K/Akt pathway. METHODS: In this study, a controlled cortical impact (CCI) model was used to induce TBI in adult male C57BL/6J mice. Subsequently, P. copri was transplanted by intragastric gavage for 7 consecutive days. To investigate the effect of the GUO-PI3K/Akt pathway in P. copri transplantation therapy, guanosine (GUO) was administered 2 h after TBI for 7 consecutive days, and PI3K inhibitor (LY294002) was administered 30 min before TBI. Various techniques were used to assess the effects of these interventions, including quantitative PCR, neurological behavior tests, metabolite analysis, ELISA, Western blot analysis, immunofluorescence, Evans blue assays, transmission electron microscopy, FITC-dextran permeability assay, gastrointestinal transit assessment, and 16 S rDNA sequencing. RESULTS: P. copri abundance was significantly reduced after TBI. P. copri transplantation alleviated motor and cognitive deficits tested by the NSS, Morris's water maze and open field test. P. copri transplantation attenuated oxidative stress and blood-brain barrier damage and reduced neuronal apoptosis after TBI. In addition, P. copri transplantation resulted in the reshaping of the intestinal flora, improved gastrointestinal motility and intestinal permeability. Metabolomics and ELISA analysis revealed a significant increase in GUO levels in feces, serum and injured brain after P. copri transplantation. Furthermore, the expression of p-PI3K and p-Akt was found to be increased after P. copri transplantation and GUO treatment. Notably, PI3K inhibitor LY294002 treatment attenuated the observed improvements. CONCLUSIONS: We demonstrate for the first time that P. copri transplantation can improve GI functions and alter gut microbiota dysbiosis after TBI. Additionally, P. copri transplantation can ameliorate neurological deficits, possibly via the GUO-PI3K/Akt signaling pathway after TBI.
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Lesões Encefálicas Traumáticas , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL , Animais , Camundongos , Masculino , Reabilitação Neurológica/métodos , Prevotella , Microbioma Gastrointestinal/fisiologia , Fosfatidilinositol 3-Quinases/metabolismoRESUMO
BACKGROUND: Because physician practices contribute to national healthcare expenditures, initiatives aimed at educating physicians about high-value cost-conscious care (HVCCC) are important. Prior studies suggest that the training environment influences physician attitudes and behaviors towards HVCCC. OBJECTIVE: To explore the relationship between medical student experiences and HVCCC attitudes. DESIGN: Quantitative and qualitative analysis of a multi-institutional survey. PARTICIPANTS: Medical students from nine US medical schools. APPROACH: A 44-item survey that included the Maastricht HVCCC Attitudes Questionnaire, a validated tool for assessing HVCCC attitudes, was administered electronically. Attitudinal domains of high-value care (HVC), cost incorporation (CI), and perceived drawbacks (PD) were compared using one-way ANOVA among students with a range of exposures. Open text responses inviting participants to reflect on their attitudes were analyzed using classical content analysis. KEY RESULTS: A total of 740 students completed the survey (response rate 15%). Students pursuing a "continuity-oriented" specialty held more favorable attitudes towards HVCCC than those pursuing "technique-oriented" specialties (HVC sub-score = 3.20 vs. 3.06; p = 0.005, CI sub-score = 2.83 vs. 2.74; p < 0.001). Qualitative analyses revealed personal, educational, and professional experiences shape students' HVCCC attitudes, with similar experiences interpreted differently leading to both more and less favorable attitudes. CONCLUSION: Students pursuing specialties with longitudinal patient contact may be more enthusiastic about practicing high-value care. Life experiences before and during medical school shape these attitudes, and complex interactions between these forces drive student perceptions of HVCCC.
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BACKGROUND: Neuroinflammation is one of the most important processes in secondary injury after traumatic brain injury (TBI). Triggering receptor expressed on myeloid cells 2 (TREM2) has been proven to exert neuroprotective effects in neurodegenerative diseases and stroke by modulating neuroinflammation, and promoting phagocytosis and cell survival. However, the role of TREM2 in TBI has not yet been elucidated. In this study, we are the first to use COG1410, an agonist of TREM2, to assess the effects of TREM2 activation in a murine TBI model. METHODS: Adult male wild-type (WT) C57BL/6 mice and adult male TREM2 KO mice were subjected to different treatments. TBI was established by the controlled cortical impact (CCI) method. COG1410 was delivered 1 h after CCI via tail vein injection. Western blot analysis, immunofluorescence, laser speckle contrast imaging (LSCI), neurological behaviour tests, brain electrophysiological monitoring, Evans blue assays, magnetic resonance imaging (MRI), and brain water content measurement were performed in this study. RESULTS: The expression of endogenous TREM2 peaked at 3 d after CCI, and it was mainly expressed on microglia and neurons. We found that COG1410 improved neurological functions within 3 d, as well as neurological functions and brain electrophysiological activity at 2 weeks after CCI. COG1410 exerted neuroprotective effects by inhibiting neutrophil infiltration and microglial activation, and suppressing neuroinflammation after CCI. In addition, COG1410 treatment alleviated blood brain barrier (BBB) disruption and brain oedema; furthermore, COG1410 promoted cerebral blood flow (CBF) recovery at traumatic injury sites after CCI. In addition, COG1410 suppressed neural apoptosis at 3 d after CCI. TREM2 activation upregulated p-Akt, p-CREB, BDNF, and Bcl-2 and suppressed TNF-α, IL-1ß, Bax, and cleaved caspase-3 at 3 d after CCI. Moreover, TREM2 knockout abolished the effects of COG1410 on vascular phenotypes and microglial states. Finally, the neuroprotective effects of COG1410 were suppressed by TREM2 depletion. CONCLUSIONS: Altogether, we are the first to demonstrate that TREM2 activation by COG1410 alleviated neural damage through activation of Akt/CREB/BDNF signalling axis in microglia after CCI. Finally, COG1410 treatment improved neurological behaviour and brain electrophysiological activity after CCI.
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Lesões Encefálicas Traumáticas , Animais , Masculino , Camundongos , Lesões Encefálicas Traumáticas/tratamento farmacológico , Lesões Encefálicas Traumáticas/genética , Lesões Encefálicas Traumáticas/imunologia , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/imunologia , Glicoproteínas de Membrana/agonistas , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/imunologia , Camundongos Endogâmicos C57BL , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/imunologia , Receptores Imunológicos/agonistas , Receptores Imunológicos/genética , Receptores Imunológicos/imunologia , Modelos Animais de Doenças , Doenças Neuroinflamatórias/tratamento farmacológico , Doenças Neuroinflamatórias/genética , Doenças Neuroinflamatórias/imunologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/imunologia , Sistema Nervoso/efeitos dos fármacos , Sistema Nervoso/imunologiaRESUMO
M(NHx ) intermediates involved in N-N bond formation are central to ammonia oxidation (AO) catalysis, an enabling technology to ultimately exploit ammonia (NH3 ) as an alternative fuel source. While homocoupling of a terminal amide species (M-NH2 ) to form hydrazine (N2 H4 ) has been proposed, well-defined examples are without precedent. Herein, we discuss the generation and electronic structure of a NiIII -NH2 species that undergoes bimolecular coupling to generate a NiII 2 (N2 H4 ) complex. This hydrazine adduct can be further oxidized to a structurally unusual Ni2 (N2 H2 ) species; this releases N2 in the presence of NH3 , thus establishing a synthetic cycle for Ni-mediated AO. Distribution of the redox load for H2 N-NH2 formation via NH2 coupling between two metal centers presents an attractive strategy for AO catalysis using Earth-abundant, late first-row metals.
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Terminal NiIII hydrides are proposed intermediates in proton reduction catalyzed by both molecular electrocatalysts and metalloenzymes, but well-defined examples of paramagnetic nickel hydride complexes are largely limited to bridging hydrides. Herein, we report the synthesis of an S = 1/2, terminally bound thiolate-NiIII-H complex. This species and its terminal hydride ligand in particular have been thoroughly characterized by vibrational and EPR techniques, including pulse EPR studies. Corresponding DFT calculations suggest appreciable spin leakage onto the thiolate ligand. The hyperfine coupling to the terminal hydride ligand of the thiolate-NiIII-H species is comparable to that of the hydride ligand proposed for the Ni-C hydrogenase intermediate (NiIII-H-FeII). Upon warming, the featured thiolate-NiIII-H species undergoes bimolecular reductive elimination of H2. Associated kinetic studies are discussed and compared with a structurally related FeIII-H species that has also recently been reported to undergo bimolecular H-H coupling.
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Believed to accumulate on the Fe sites of the FeMo-cofactor (FeMoco) of MoFe-nitrogenase under turnover, strongly donating hydrides have been proposed to facilitate N2 binding to Fe and may also participate in the hydrogen evolution process concomitant to nitrogen fixation. Here, we report the synthesis and characterization of a thiolate-coordinated FeIII(H)(N2) complex, which releases H2 upon warming to yield an FeII-N2-FeII complex. Bimolecular reductive elimination of H2 from metal hydrides is pertinent to the hydrogen evolution processes of both enzymes and electrocatalysts, but well-defined examples are uncommon and usually observed from diamagnetic second- and third-row transition metals. Kinetic data obtained on the HER of this ferric hydride species are consistent with a bimolecular reductive elimination pathway, arising from cleavage of the Fe-H bond with a computationally determined BDFE of 55.6 kcal/mol.
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Compostos Férricos/química , Hidrogênio/química , Molibdoferredoxina/química , Nitrogênio/química , Compostos de Sulfidrila/química , Compostos Férricos/síntese química , Ligantes , Modelos Moleculares , Molibdoferredoxina/síntese química , Oxirredução , Compostos de Sulfidrila/síntese química , Temperatura , TermodinâmicaRESUMO
Stepwise metalation of the hexadentate ligand tbsLH6 (tbsLH6 = 1,3,5-C6H9(NHC6H4-o-NHSiMe2tBu)3) affords bimetallic trinuclear clusters (tbsL)Fe2Zn(thf) and (tbsL)Fe2Zn(py). Reactivity studies were pursued to understand metal atom lability as the clusters undergo ligand substitution, redox chemistry, and group transfer processes. Chloride addition to (tbsL)Fe2Zn(thf) resulted in a mixture of species including both all-zinc and all-iron products. Addition of ArN3 (Ar = Ph, 3,5-(CF3)2C6H3) to (tbsL)Fe2Zn(py) yielded a mixture of two trinuclear products: (tbsL)Fe3(µ3-NAr) and (tbsL)Fe2Zn(µ3-NAr)(py). The two imido species were separated via crystallization, and outer sphere reduction of (tbsL)Fe2Zn(µ3-NAr)(py) resulted in the formation of a single product, [2,2,2-crypt(K)][(tbsL)Fe2Zn(µ3-NAr)]. These results provide insight into the relationship between heterometallic cluster structure and substitutional lability and could help inform both future catalyst design and our understanding of metal atom lability in bioinorganic systems.
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BACKGROUND: White matter injury (WMI) is an important pathological process after traumatic brain injury (TBI). The correlation between white matter functions and the myeloid cells expressing triggering receptor-2 (TREM2) has been convincingly demonstrated. Moreover, a recent study revealed that microglial sterol metabolism is crucial for early remyelination after demyelinating diseases. However, the potential roles of TREM2 expression and microglial sterol metabolism in WMI after TBI have not yet been explored. METHODS: Controlled cortical injury was induced in both wild-type (WT) and TREM2 depletion (TREM2 KO) mice to simulate clinical TBI. COG1410 was used to upregulate TREM2, while PLX5622 and GSK2033 were used to deplete microglia and inhibit the liver X receptor (LXR), respectively. Immunofluorescence, Luxol fast blue staining, magnetic resonance imaging, transmission electron microscopy, and oil red O staining were employed to assess WMI after TBI. Neurological behaviour tests and electrophysiological recordings were utilized to evaluate cognitive functions following TBI. Microglial cell sorting and transcriptomic sequencing were utilized to identify alterations in microglial sterol metabolism-related genes, while western blot was conducted to validate the findings. RESULTS: TREM2 expressed highest at 3 days post-TBI and was predominantly localized to microglial cells within the white matter. Depletion of TREM2 worsened aberrant neurological behaviours, and this phenomenon was mediated by the exacerbation of WMI, reduced renewal of oligodendrocytes, and impaired phagocytosis ability of microglia after TBI. Subsequently, the upregulation of TREM2 alleviated WMI, promoted oligodendrocyte regeneration, and ultimately facilitated the recovery of neurological behaviours after TBI. Finally, the expression of DHCR24 increased in TREM2 KO mice after TBI. Interestingly, TREM2 inhibited DHCR24 and upregulated members of the LXR pathway. Moreover, LXR inhibition could partially reverse the effects of TREM2 upregulation on electrophysiological activities. CONCLUSIONS: We demonstrate that TREM2 has the potential to alleviate WMI following TBI, possibly through the DHCR24/LXR pathway in microglia.
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Lesões Encefálicas Traumáticas , Glicoproteínas de Membrana , Microglia , Receptores Imunológicos , Substância Branca , Animais , Masculino , Camundongos , Lesões Encefálicas Traumáticas/metabolismo , Lesões Encefálicas Traumáticas/genética , Modelos Animais de Doenças , Receptores X do Fígado/metabolismo , Receptores X do Fígado/genética , Glicoproteínas de Membrana/metabolismo , Glicoproteínas de Membrana/genética , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microglia/metabolismo , Receptores Imunológicos/metabolismo , Receptores Imunológicos/genética , Substância Branca/metabolismo , Substância Branca/patologiaRESUMO
Efforts to produce aromatic monomers through catalytic lignin depolymerization have historically focused on aryl-ether bond cleavage. A large fraction of aromatic monomers in lignin, however, are linked by various carbon-carbon (C-C) bonds that are more challenging to cleave and limit the yields of aromatic monomers from lignin depolymerization. Here, we report a catalytic autoxidation method to cleave C-C bonds in lignin-derived dimers and oligomers from pine and poplar. The method uses manganese and zirconium salts as catalysts in acetic acid and produces aromatic carboxylic acids as primary products. The mixtures of the oxygenated monomers are efficiently converted to cis,cis-muconic acid in an engineered strain of Pseudomonas putida KT2440 that conducts aromatic O-demethylation reactions at the 4-position. This work demonstrates that autoxidation of lignin with Mn and Zr offers a catalytic strategy to increase the yield of valuable aromatic monomers from lignin.
RESUMO
Concomitant deprotonation and metalation of hexadentate ligand platform (tbs)LH6 ((tbs)LH6 = 1,3,5-C6H9(NHC6H4-o-NHSiMe2(t)Bu)3) with divalent transition metal starting materials Fe2(Mes)4 (Mes = mesityl) or Mn3(Mes)6 in the presence of tetrahydrofuran (THF) resulted in isolation of homotrinuclear complexes ((tbs)L)Fe3(THF) and ((tbs)L)Mn3(THF), respectively. In the absence of coordinating solvent (THF), the deprotonation and metalation exclusively afforded dinuclear complexes of the type ((tbs)LH2)M2 (M = Fe or Mn). The resulting dinuclear species were utilized as synthons to prepare bimetallic trinuclear clusters. Treatment of ((tbs)LH2)Fe2 complex with divalent Mn source (Mn2(N(SiMe3)2)4) afforded the bimetallic complex ((tbs)L)Fe2Mn(THF), which established the ability of hexamine ligand (tbs)LH6 to support mixed metal clusters. The substitutional homogeneity of ((tbs)L)Fe2Mn(THF) was determined by (1)H NMR, (57)Fe Mössbauer, and X-ray fluorescence. Anomalous scattering measurements were critical for the unambiguous assignment of the trinuclear core composition. Heating a solution of ((tbs)LH2)Mn2 with a stoichiometric amount of Fe2(Mes)4 (0.5 mol equiv) affords a mixture of both ((tbs)L)Mn2Fe(THF) and ((tbs)L)Fe2Mn(THF) as a result of the thermodynamic preference for heavier metal substitution within the hexa-anilido ligand framework. These results demonstrate for the first time the assembly of mixed metal cluster synthesis in an unbiased ligand platform.
Assuntos
Complexos de Coordenação/síntese química , Compostos Ferrosos/química , Manganês/química , LigantesRESUMO
Myelin sheath injury contributes to cognitive deficits following subarachnoid hemorrhage (SAH). G protein-coupled receptor 17 (GPR17), a membrane receptor, negatively regulates oligodendrocyte precursor cell (OPC) differentiation in both developmental and pathological contexts. Nonetheless, GPR17's role in modulating OPC differentiation, facilitating remyelination post SAH, and its interaction with downstream molecules remain elusive. In a rat SAH model induced by arterial puncture, OPCs expressing GPR17 proliferated prominently by day 14 post-onset, coinciding with compromised myelin sheath integrity and cognitive deficits. Selective Gpr17 knockdown in oligodendrocytes (OLs) via adeno-associated virus (AAV) administration revealed that reduced GPR17 levels promoted OPC differentiation, restored myelin sheath integrity, and improved cognitive deficits by day 14 post-SAH. Moreover, GPR17 knockdown attenuated the elevated expression of the inhibitor of DNA binding 2 (ID2) post-SAH, suggesting a GPR17-ID2 regulatory axis. Bi-directional modulation of ID2 expression in OLs using AAV unveiled that elevated ID2 counteracted the restorative effects of GPR17 knockdown. This resulted in hindered differentiation, exacerbated myelin sheath impairment, and worsened cognitive deficits. These findings highlight the pivotal roles of GPR17 and ID2 in governing OPC differentiation and axonal remyelination post-SAH. This study positions GPR17 as a potential therapeutic target for SAH intervention. The interplay between GPR17 and ID2 introduces a novel avenue for ameliorating cognitive deficits post-SAH.
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Selective lignin depolymerization is a key step in lignin valorization to value-added products, and there are multiple catalytic methods to cleave labile aryl-ether bonds in lignin. However, the overall aromatic monomer yield is inherently limited by refractory carbon-carbon linkages, which are abundant in lignin and remain intact during most selective lignin deconstruction processes. In this work, we demonstrate that a Co/Mn/Br-based catalytic autoxidation method promotes carbon-carbon bond cleavage in acetylated lignin oligomers produced from reductive catalytic fractionation. The oxidation products include acetyl vanillic acid and acetyl vanillin, which are ideal substrates for bioconversion. Using an engineered strain of Pseudomonas putida, we demonstrate the conversion of these aromatic monomers to cis,cis-muconic acid. Overall, this study demonstrates that autoxidation enables higher yields of bioavailable aromatic monomers, exceeding the limits set by ether-bond cleavage alone.
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CGA1-78 (Vasostatin-1, VS-1) a N-terminal Chromogranin A (CGA)-derived peptide, has been shown to have a protective effect against TNF-α-induced impairment of endothelial cell integrity. However, the mechanisms of this effect have not yet been clarified. CGA47-66 (Chromofungin, CHR) is an important bioactive fragment of CGA1-78. The present study aims to explore the protective effects of CHR on the vascular endothelial cell barrier response to TNF-α and its related Ca2+ signaling mechanisms. EA.hy926 cells were used as a vascular endothelial culture model. The synthetic peptides CHR and CGA4-16 were assessed for their ability to suppress TNF-α-induced EA.hy926 cells hyper-permeability through Transwell® and TEER assays. Changes in [Ca2+]i were measured through confocal laser scanning microscopy. SOC channel currents (Isoc) were measured via patch-clamp analysis. RT-PCR and western blot were used to analyze mRNA and protein expression of the transient receptor potential channels TRPC1 and TRPC4, respectively. FITC and rhodamine-phalloidin fluorescence were used to assess cell morphology and the distribution of MyPT-1 and F-actin. Compared to untreated cells, TNF-α increased the permeability of EA.hy926 cells that was inhibited by pre-treatment with CHR (10-1000 nM) in concentration-dependent manner, and the effect was most obvious at 100 nM, but CGA4-16 (100 nM) had no effect. TNF-α treatment increased the phosphorylation of MyPT-1 and stress fiber formation. CHR (10-1000 nM) pretreatment inhibited the cytoskeletal rearrangements and increased [Ca2+]i in response to TNF-α treatment. CHR also reduced TRPC1 expression following TNF-α induction. Similar to SOC inhibitor 2-APB, CHR suppressed IP3 mediated SOC activation. These findings suggest that CHR inhibits TNF-α-induced Ca2+ influx and protects the barrier function of vascular endothelial cells, and that these effects are related to the inhibition of SOC and Ca2+ signaling by CHR.
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Sinalização do Cálcio/efeitos dos fármacos , Cromogranina A/farmacologia , Células Endoteliais/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Canais de Cátion TRPC/metabolismo , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Citoesqueleto de Actina/efeitos dos fármacos , Citoesqueleto de Actina/metabolismo , Citoesqueleto de Actina/ultraestrutura , Actinas/genética , Actinas/metabolismo , Cálcio/metabolismo , Linhagem Celular Transformada , Permeabilidade da Membrana Celular/efeitos dos fármacos , Cultura em Câmaras de Difusão , Relação Dose-Resposta a Droga , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Regulação da Expressão Gênica , Humanos , Inositol 1,4,5-Trifosfato/metabolismo , Fosfatase de Miosina-de-Cadeia-Leve/genética , Fosfatase de Miosina-de-Cadeia-Leve/metabolismo , Técnicas de Patch-Clamp , Fosforilação , Canais de Cátion TRPC/antagonistas & inibidores , Canais de Cátion TRPC/genética , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
A heterobimetallic VFe complex is demonstrated to catalyse hydrazine disproportionation with yields of up to 1073 equivalents of NH3 per catalyst, comparable to the highest turnover known for any molecular catalyst. Notably, the heterobimetallic complex is appreciably more active than monometallic analogues of the V and Fe sites, suggesting that bimetallic cooperativity may facilitate the observed catalysis.
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OBJECTIVE: Ulinastatin reduces the high permeability of vascular endothelial cells induced by tumor necrosis factor alpha (TNF-α). This study investigated the molecular mechanism behind this effect, with the aim of understanding the action of ulinastatin in sepsis therapy and exploring novel therapeutic strategies for sepsis patients. METHODS: A TNF-α treated human umbilical vein endothelial cell line (EA.hy926) was employed as an inflammation model. Horseradish peroxidase permeability assays and an epithelial voltmeter method were used to measure the permeability of EA.hy926 cells. Immunocytochemistry was used to assay the expression of p-MYPT1 and the distribution and morphology of F-actin; the expression of the key molecules related to vascular endothelial permeability (RhoA, ROCK2, MYPT1, p-MYPT1 and VE-cadherin) was detected by immunocytochemistry assays, western blotting and quantitative real-time polymerase chain reaction. RESULTS: After incubation with TNF-α or septic serum, the transendothelial electrical resistance of EA.hy926 cells decreased and the permeability of the cells increased significantly (all P<0.05). The expression of p-MYPT1 was higher and VE-cadherin was lower compared with the control group, and F-actin was redistributed, with the formation of additional stress fibers in the cells. Ulinastatin treatment moderated these phenomena. The immunocytochemistry assays and western blots showed that the expression of RhoA and ROCK2 was significantly upregulated in cells treated with TNF-α (P<0.05); however, ulinastatin could inhibit the high expression of these two proteins. Under treatment with TNF-α and ulinastatin, compared with normal EA.hy926 cells, overexpression of RhoA upregulated expression of RhoA, ROCK2 and p-MYPT1, downregulated expression of VE-cadherin, and restored the hyperpermeability of vascular endothelial cells due to TNF-α treatment (P<0.05). CONCLUSIONS: Ulinastatin inhibited the hyperpermeability of vascular endothelial cells induced by TNF-α. This inhibitory effect of ulinastatin may be related to the RhoA/ROCK signaling pathway.
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Anti-Inflamatórios/farmacologia , Permeabilidade Capilar/efeitos dos fármacos , Endotélio Vascular/metabolismo , Glicoproteínas/farmacologia , Sepse/metabolismo , Quinases Associadas a rho/metabolismo , Proteína rhoA de Ligação ao GTP/metabolismo , Actinas/metabolismo , Caderinas/metabolismo , Linhagem Celular Transformada , Impedância Elétrica , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/patologia , Regulação da Expressão Gênica , Humanos , Lentivirus/genética , Fosfatase de Miosina-de-Cadeia-Leve/genética , Fosfatase de Miosina-de-Cadeia-Leve/metabolismo , Sepse/imunologia , Transdução de Sinais/efeitos dos fármacos , Fibras de Estresse/efeitos dos fármacos , Fibras de Estresse/patologia , Fator de Necrose Tumoral alfa/metabolismoRESUMO
OBJECTIVE: The objective was to investigate the correlation between single nucleotide polymorphism (SNP) of chromogranin A (CHGA) and prognosis of critically ill patients. METHODS: We screened 357 critically ill patients consecutively admitted to our intensive care unit. The -89/-415/-462 SNP locus in the promoter region and the +9559/+9578/+9590/+9611 SNP locus in exon 7 coding of CHGA were genotyped by polymerase chain reaction and DNA sequencing technology. Subsequently, the correlation between genotype and prognosis of patients was analyzed. RESULTS: (1) Three hundred critically ill Chinese Han patients were enrolled in the study. CHGA-415/-462/+9559/+9611 SNPs were polymorphically distributed. Phenotypes of the 4 SNPs were shown not to be in linkage disequilibrium, and there were no significant differences in the minor allele frequencies (MAFs) of the 4 SNPs between participants of this study and healthy people in Asia. (2) The CHGA-415 T/C MAF of the nonsurvival group was significantly higher than that of the survival group (MAF 0.3813 and 0.2864, respectively; P=.026). Survival analysis showed that there were significant differences between the CHGA-415 T/C mutation group (including TC and CC genotypes) and the wild-type group (TT genotype) (log rank=8.887, P=.003). The mortality in the mutant group was significantly higher than that in the wild-type group (0.3333 and 0.1852, respectively; P=.004). (3) Binary logistic analysis showed that CHGA-415 T/C polymorphism was an independent risk factor for the mortality of critically ill patients (odds ratio, 2.286; 95% confidence interval, 1.165-4.484; P=.016). CONCLUSIONS: Critically ill patients with CHGA-415 T/C mutant genotype display higher 30-day mortality than those with the wild-type group. CHGA-415 T/C polymorphism is an independent risk factor of poor prognosis in critically ill Chinese Han patients.
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Cromogranina A/genética , Estado Terminal , Polimorfismo de Nucleotídeo Único/genética , Adulto , Idoso , China/etnologia , Feminino , Frequência do Gene/genética , Genótipo , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Razão de Chances , Reação em Cadeia da Polimerase , Prognóstico , Fatores de RiscoRESUMO
[Re(bpy-tBu)(CO)4](OTf) (bpy-tBu = 4,4'-di-tert-butyl-2,2'-bipyridine, OTf = trifluoromethanesulfonate) (1) and [Re(bpy)(CO)4](OTf) (bpy = 2,2'-bipyridine) (2) were synthesized and studied as proposed intermediates in the electrocatalytic reduction of carbon dioxide (CO2) by Re(bpy-R)(CO)3X. Both compounds demonstrated increased current responses in cyclic voltammograms under CO2. Complex 1 was also characterized by X-ray crystallography. Infrared-spectroelectrochemistry (IR-SEC) of 1 and 2 indicated that upon exposure of the cationic tetracarbonyl compounds to a reducing potential, a CO ligand is labilised and [Re(bpy-R)(CO)3(CH3CN)](+) species are formed. This is proposed to occur via an electron-transfer-catalysed process wherein a catalytic amount of reduced species propagates a ligand exchange reaction. Addition of a catalytic amount of potassium intercalated graphite (KC8), a chemical reductant, to a solution of 1 or 2 also yielded quantitative formation of [Re(bpy-R)(CO)3(CH3CN)](+), which indicates that the CO loss is catalysed by electron transfer, and not the electrode itself.
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OBJECTIVE: To explore the role of chromogranin A ( CGA) derived peptide CGA47~ ( Chromfungin, CHR) on septic serum induced high permeability of vascular endothelial cells. METHODS: Human umbilical venous endothelial cell line (EA.hy926 cells) was exposed to CHR, serum of septic shock patient, and tumor necrosis factor-a (TNF-a) respectively. Methyl thiazolyl tetrazolium (MTT) method, Transwell assay and immunofluorescence were performed to determine cell viability (absorbance (A) value J, permeability of monolayer endothelial cells (A value) , and the morphological characteristic and distribution ofF -actin respectively. RESULTS: Compared with the blank control group, when EA.hy926 were exposed to CHR with 1, 10, 100 nmol/L the cell activity was not significantly affected (A value: 1.219 ± 0.253, 1.179 ± 0.065, 1.179 ± 0.062 vs. 1.306 ± 0.162, all P>0.05), while when the cells was exposed to CHR in 1 000 nmol/L the cell activity was significantly inhibited (A value: 1.049 ± 0.256 vs. 1.306 ± 0.162, t=-2.390, P=0.031 ). Compared with blank control group, when the cells were exposed to CHR of 1, 10, 100 nmol/L a significant decrease in permeability in EA.hy926 cells was observed (A value: 1.619 ± 0.324, 1.496 ± 0.356, 1.132 ± 0.280 vs. 2.315 ± 0.440, P<0.05 or P<0.01 ). Treatment of septic shock patient's serum or TNF-a to EA. hy926 produced an obvious increase in its permeability (septic serum group A value: 1.204 ± 0.248 vs. 0.277 ± 0.017, P<0.01; TNF-a group A value: 2.485 ± 0.113 vs. 1.602 ± 0.679, P<0.05). High-permeability induced by TNF-a or septic shock patient's serum was alleviated hy CHR in the concentration of 1, 10, 100 nmol/L in a dose-dependent manner (septic serum + CHR group A value: 0.299 ± 0.065, 0.224 ± 0.028, 0.131 ± 0.015 vs. 1.204 ± 0.248; TNF -a + CHR group A value: 1.995 ± 0.394, 1.920 ± 0.096, 1.744 ± 0.475 vs. 2.485 ± 0.113, P<0.05 or P<0.01 ). Under a laser scanning confocal microscope, it was found that the F-actin cytoskeleton of EA.hy926 cells was redistributed, and more stress fibers were found in the septic shock patient's serum group and TNF-α group, while CHR obviously alleviated the above effects induced by septic shock patient's serum or TNF-α. CONCLUSION: In a dose-dependent manner, CHR may inhibit increased permeability of vascular endothelial cells induced by septic shock patient's serum, its underlying mechanism may be related to inhibition of the effect of TNF-α.