Polynitroxyl albumin plus tempol attenuates liver injury and inflammation after hepatic ischemia and reperfusion

PNA+Tempol, albumin containing conjugated (polynitroxyl albumin; PNA) and free (4-hydroxyl-2,2,6,6-tetramethyl-piperidinyl-1-oxyl; Tempol) nitroxide may protect against injury caused by reactive oxygen species. Therefore, the actions of PNA+Tempol on liver injury and inflammation induced by hepatic ischemia and reperfusion (I/R) were examined. Rats were subjected to 1 h ischemia followed by 24 h reperfusion in the absence (I/R) or presence of PNA+Tempol (25%; 15 mL/kg, i.v.) (I/R+PNA+Tempol) or human serum albumin (23%; 13.5 mL/kg, i.v.) (I/R+HSA). Test solutions were administered prior to and for 2 h during reperfusion. Sham-operated rats underwent surgery with neither ischemia nor infusion. I/R+PNA+Tempol rats had significantly less liver injury and inflammation than I/R rats. I/R+PNA+Tempol livers exhibited focal lesions whereas I/R livers exhibited global necrosis. Likewise, plasma ALT activity was significantly lower in I/R+PNA+Tempol rats. PNA+Tempol reduced I/R-induced neutrophil accumulation and intercellular adhesion molecule-1 (ICAM-1) expression. HSA did not alter I/R-induced liver injury or inflammation. Sham-operated rats exhibited normal liver morphology and no inflammation. Attenuation of I/R liver injury by PNA+Tempol may be mediated by its effect on inflammation, the major contributor to I/R injury. Reduction of inflammation by PNA+Tempol is most likely due to the antioxidative nature of the nitroxides.     

Association of serum markers with improvement in clinical response measures after treatment with golimumab in patients with active rheumatoid arthritis despite receiving methotrexate: results from the GO-FORWARD study

Introduction  

The goal of this study was to identify serum markers that are modulated by treatment with golimumab with or without methotrexate (MTX) and are associated with clinical response.     

Recent advances in plant recombination

Recombination is an essential cellular process and a source of genetic diversity. Recent studies have demonstrated the effects of various factors (e.g. DNA sequence similarity and activation of transposons) on rates of recombination and the distribution of recombination breakpoints in plants. These studies have also provided detailed characterizations of interchromatid and interhomolog recombination events. New approaches offer the promise of achieving the long-awaited goal of gene targeting in plants.     

Golimumab in patients with active rheumatoid arthritis after treatment with tumor necrosis factor α inhibitors: findings with up to five years of treatment in the multicenter,randomized, double-blind,placebo-controlled,phase 3 GO-AFTER study

IntroductionThe aim of this study was to assess long-term golimumab therapy in rheumatoid arthritis (RA) patients who discontinued previous tumor necrosis factor-α (TNF)-inhibitor(s).MethodsPatients enrolled into this multicenter, randomized, double-blind, placebo-controlled study of active RA (≥4 tender, ≥4 swollen joints) received placebo (Group 1) or golimumab 50 mg (Group 2) or 100 mg (Group 3) injections every 4 weeks. Patients in Groups 1 and 2 with inadequate response at week 16 escaped to golimumab 50 and 100 mg, respectively. At week 24, Group 1 patients crossed-over to golimumab 50 mg, Group 2 continued golimumab 50/100 mg per escape status, and Group 3 maintained dosing. During the long-term-extension (LTE), golimumab 50 mg could be increased to 100 mg, and 100 mg could be decreased to 50 mg. Data through 5 years are reported for all patients (safety) and patients using methotrexate (efficacy, intention-to-treat (ITT) analysis with last-observation-carried-forward for missing data and non-responder imputation for unsatisfactory efficacy discontinuations).ResultsIn total, 459 of 461 randomized patients received the study agent, 304 of whom were methotrexate-treated and included in efficacy analyses. Through week 256, the proportions of methotrexate-treated patients achieving American-College-of-Rheumatology (ACR) responses were 37.6% to 47.0% for ACR20, 21.4% to 35.0% for ACR50, and 7.8% to 17.0% for ACR70 response across randomized groups. Golimumab safety through week 268 was generally consistent with that at week 24 and week 160 and other anti-TNF agents.ConclusionsIn some patients with active RA discontinuing previous TNF-antagonist therapy, golimumab safety and efficacy, assessed conservatively with ITT analyses, was confirmed through 5 years.

Trial registration

Clinicaltrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00299546","term_id":"NCT00299546"}}NCT00299546. Registered 03 March 2006.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0516-6) contains supplementary material, which is available to authorized users.     

Impact of taxol on dermal papilla cells--a proteomics and bioinformatics analysis

Dermal papilla (DP) cells play a regulatory role in hair growth, and also play a role in alopecia (hair loss). However, effects of taxol, which is a widely used chemotherapy drug, on DP cells remain unclear, despite that theoretically taxol can impact on DP cells to contribute to taxol-induced alopecia. To better understand pathophysiology of taxol-induced damage in DP cells, morphological and biochemical analyses were performed to check whether taxol can cause apoptosis in cultured DP cells or not. If it can, proteomics and bioinformatics analyses were then performed to investigate the protein networks which are impacted by the taxol treatment. Our data showed that taxol can cause apoptotic damage in DP cells in a concentration-dependant manner, as demonstrated by various apoptotic markers. Proteomic analysis on DP cells treated with the lowest apoptosis-inducible concentration of taxol revealed that taxol can affect expression of proteins involved in Ca2+-regulated biological processes, vesicles transport, protein folding, reductive detoxification, and biomolecules metabolism. Furthermore, bioinformatics analysis indicated that taxol can impact on multiple biological networks. Taken together, this biochemical, proteomics, and bioinformatics data may give an insight into pathophysiology of taxol-induced damage in DP cells and shed light on mechanisms underlying taxol-induced alopecia.     

Integrin alpha4beta1 promotes focal adhesion kinase-independent cell motility via alpha4 cytoplasmic domain-specific activation of c-Src

The fibronectin binding integrins alpha5beta1 and alpha4beta1 generate signals pivotal for cell migration through distinct yet undefined mechanisms. For alpha5beta1, beta1-mediated activation of focal adhesion kinase (FAK) promotes c-Src recruitment to FAK and the formation of a FAK-Src signaling complex. Herein, we show that FAK expression is essential for alpha5beta1-stimulated cell motility and that exogenous expression of human alpha4 in FAK-null fibroblasts forms a functional alpha4beta1 receptor that promotes robust cell motility equal to the alpha5beta1 stimulation of wild-type and FAK-reconstituted fibroblasts. alpha4beta1-stimulated FAK-null cell spreading and motility were dependent on the integrity of the alpha4 cytoplasmic domain, independent of direct paxillin binding to alpha4, and were not affected by PRNK expression, a dominant-negative inhibitor of Pyk2. alpha4 cytoplasmic domain-initiated signaling led to a approximately 4-fold activation of c-Src which did not require paxillin binding to alpha4. Notably, alpha4-stimulated cell motility was inhibited by catalytically inactive receptor protein-tyrosine phosphatase alpha overexpression and blocked by the p50Csk phosphorylation of c-Src at Tyr-529. alpha4beta1-stimulated cell motility of triple-null Src(-/-), c-Yes(-/-), and Fyn(-/-) fibroblasts was dependent on c-Src reexpression that resulted in p130Cas tyrosine phosphorylation and Rac GTPase loading. As p130Cas phosphorylation and Rac activation are common downstream targets for alpha5beta1-stimulated FAK activation, our results support the existence of a novel alpha4 cytoplasmic domain connection leading to c-Src activation which functions as a FAK-independent linkage to a common motility-promoting signaling pathway.     

Fibronectin fragmentation promotes alpha4beta1 integrin-mediated contraction of a fibrin-fibronectin provisional matrix

In injured tissues, the fibrin-fibronectin (FN) provisional matrix provides a framework for cell adhesion, migration, and repair. Effective repair and remodeling require a proper balance between extracellular matrix (ECM) deposition, contraction, and turnover. We utilized a three-dimensional (3D) fibrin-FN provisional matrix model to determine the contributions of the FN-binding integrin receptors alpha5beta1 and alpha4beta1 to matrix contraction. CHOalpha5 cells expressing alpha5beta1, a receptor for FN's RGD cell-binding domain, were highly contractile, and cells were well spread on a 3D fibrin-FN matrix. In contrast, CHOalpha4 cells expressing the alpha4beta1 receptor for FN's alternatively spliced V region attached less efficiently to FN and were deficient in fibrin-FN matrix contraction. Surprisingly, cell adhesion and matrix contraction by CHOalpha4 cells were dramatically enhanced, to levels equivalent to CHOalpha5 cells, when proteolyzed FN was used in place of intact FN in the fibrin-FN matrix. Similar enhancement was observed when ligand binding by alpha4beta1 integrins was activated by treatment with Mn(++), but not by stimulation of actin organization with LPA. Therefore, alpha4beta1-dependent cell responses to the provisional matrix are modulated by cleavage of matrix components.