VEGF-A165b Is an Endogenous Neuroprotective Splice Isoform of Vascular Endothelial Growth Factor A in?Vivo and in?Vitro

Vascular endothelial growth factor (VEGF) A is generated as two isoform families by alternative RNA splicing, represented by VEGF-A₁₆₅a and VEGF-A₁₆₅b. These isoforms have opposing actions on vascular permeability, angiogenesis, and vasodilatation. The proangiogenic VEGF-A₁₆₅a isoform is neuroprotective in hippocampal, dorsal root ganglia, and retinal neurons, but its propermeability, vasodilatatory, and angiogenic properties limit its therapeutic usefulness. In contrast, a neuroprotective effect of endogenous VEGF-A₁₆₅b on neurons would be advantageous for neurodegenerative pathologies. Endogenous expression of human and rat VEGF-A₁₆₅b was detected in hippocampal and cortical neurons. VEGF-A₁₆₅b formed a significant proportion of total VEGF-A in rat brain. Recombinant human VEGF-A₁₆₅b exerted neuroprotective effects in response to multiple insults, including glutamatergic excitotoxicity in hippocampal neurons, chemotherapy-induced cytotoxicity of dorsal root ganglion neurons, and retinal ganglion cells (RGCs) in rat retinal ischemia-reperfusion injury in vivo. Neuroprotection was dependent on VEGFR2 and MEK1/2 activation but not on p38 or phosphatidylinositol 3–kinase activation. Recombinant human VEGF-A₁₆₅b is a neuroprotective agent that effectively protects both peripheral and central neurons in vivo and in vitro through VEGFR2, MEK1/2, and inhibition of caspase-3 induction. VEGF-A₁₆₅b may be therapeutically useful for pathologies that involve neuronal damage, including hippocampal neurodegeneration, glaucoma diabetic retinopathy, and peripheral neuropathy. The endogenous nature of VEGF-A₁₆₅b expression suggests that non–isoform-specific inhibition of VEGF-A (for antiangiogenic reasons) may be damaging to retinal and sensory neurons.Vascular endothelial growth factor (VEGF) A, originally described as a potent vascular permeability and growth factor for endothelial cells, is up-regulated in the brain during stroke and ischemic episodes¹ and has been linked with many neuronal diseases. The most widely studied isoform of VEGF-A, VEGF-A₁₆₅a, is up-regulated in hypoxia, induces increased vascular permeability in neuronal vasculature, and can stimulate angiogenesis after ischemic episodes. The resulting edema and hyperemia can be damaging, but VEGF-A₁₆₅a has also been found to have direct anticytotoxic effects on neurons, raising the possibility that it may act as an endogenous neuroprotective agent in neurodegenerative pathologies. VEGF-A exerts neurotrophic (survival) and neurotropic (neurogenesis and axon outgrowth) actions, which, although initially thought to be a function of increased angiogenesis and perfusion after neuronal injury,² are now appreciated as direct effects of VEGF-A on neurons.The vegfa gene encodes numerous products by differential splicing, but not all isoforms exert the same effects.³ Alternative splicing of exon 8 leads to two functionally distinct families: the proangiogenic VEGF-A_xxxa family and the counteracting VEGF-A_xxxb family.^4,5 VEGF-A₁₆₅b prevents the VEGF-A₁₆₅a effects on increased vascular permeability, blood vessel growth, and vasodilatation.^4–7The therapeutic potential of VEGF-A and anti–VEGF-A treatments are now widely recognized, and effective anti–VEGF-A treatments are available in ophthalmology⁸ and oncology.⁹ The finding that VEGF-A is implicated in neuronal disorders (eg, Alzheimer disease, Parkinson disease, Huntington disease, diabetic neuropathy, and amyotrophic lateral sclerosis¹⁰) provides a rationale for the use of VEGF-A as a therapeutic agent in neurodegenerative conditions. Although this rationale is supported by preclinical evidence,¹¹ the identification of the VEGF-A_xxxb family requires reexamination of VEGF-A isoforms in these contexts to allow for the clear evidence that VEGF-A splicing variants are not functionally equivalent³ and to determine whether augmentation of the proangiogenic isoform family (VEGF-A_xxxa) alone may have deleterious effects (eg, in occult malignancy and carcinoma in situ).The neuroprotective profile of the exon 8 alternatively spliced isoforms VEGF-A_xxxb remains unexplored. Interestingly, VEGF-A_xxxb isoforms do not exhibit the vascular effects seen with VEGF-A_xxxa isoforms, such as a sustained increase in capillary permeability or hypotension.^5,12 The lack of these potential adverse effects may make VEGF-A_xxxb isoforms more amenable as therapeutic agents in neurodegenerative diseases.We therefore tested the hypothesis that VEGF-A₁₆₅b is neuroprotective for central and peripheral neurons. We found that VEGF-A₁₆₅b is expressed in central neurons and is neuroprotective in vitro and in vivo. This finding indicates that VEGF-A₁₆₅b may prove to be a suitable therapeutic agent in neurodegenerative disorders, exhibiting fewer adverse effects than VEGF-A₁₆₅a.     

Chemoradiation-induced changes in systemic inflammatory markers and their prognostic significance in oesophageal squamous cell carcinoma

Objective:Chemoradiation (CRT) may induce a change in systemic inflammatory state which could affect clinical outcomes in oesophageal cancer. We aimed to evaluate the changes and prognostic significance of systemic inflammatory markers following definitive CRT in oesophageal squamous cell carcinoma.Methods:A total of 53 patients treated with concurrent CRT were included in this retrospective analysis. We compared neutrophils, lymphocytes, platelets, neutrophil–lymphocyte ratio (NLR) and platelet–lymphocyte ratio (PLR) before and after CRT using Wilcoxon signed-rank test. Overall survival (OS) and progression-free survival (PFS) were calculated. Univariable and multivariable survival analysis were performed using Cox regression analysis. Clinical univariable survival prognostic factors with p < 0.1 were included in a multivariable cox regression analysis for backward stepwise model selection.Results:Both NLR (median ∆+2.8 [IQR −0.11, 8.62], p < 001) and PLR (median ∆+227 [81.3–523.5], p < 0.001) increased significantly after CRT. Higher levels of pre-CRT, post-CRT and change (∆) in NLR and PLR were associated with inferior OS and PFS. Post-CRT NLR (HR 1.04, 95% CI 1.02–1.07, p < 0.001), post-CRT platelets (HR 1.03, 95% CI 1.01–1.05, p = 0.005), cT-stage (HR 3.83, 95% CI 1.39–10.60, p = 0.01) and RT dose (HR 0.41, 95% CI 0.21–0.81, p = 0.01) were independent prognostic factors for OS in multivariable analysis. Change in NLR (HR 1.04, 95% CI 1.01–1.06, p = 0.001), post-CRT platelets (HR 1.03, 95% CI 1.01–1.05, p = 0.002), cT-stage (HR 3.98, 95% CI 1.55–10.25, p = 0.004) and RT dose (HR 0.41, 95% CI 0.21–0.80, p = 0.009) were independent prognostic factors for PFS.Conclusion:Both NLR and PLR increased following definitive CRT. Post-CRT NLR and ∆NLR were associated with adverse survival in oesophageal SCC.Advances in knowledge:We showed that CRT increased PLR and NLR, possibly reflecting a systemic inflammatory state which were associated with poor clinical outcomes in oesophageal SCC.     

Discordant intracellular and plasma D-2-hydroxyglutarate levels in a patient with IDH2 mutated angioimmunoblastic T-cell lymphoma

Objectives: Angioimmunoblastic T-cell lymphoma (AITL) is an aggressive peripheral T-cell lymphoma with mutations in genes encoding isocitrate dehydrogenase1 and 2 (IDH1 and IDH2). Mutant IDH generates the oncometabolite D-2-hydroxyglutarate (D-2HG). We report the first case of discordant intracellular and plasma D-2HG levels in a patient with IDH2 R172S mutated AITL. Methods: An 87-year-old woman was diagnosed with AITL in the groin lymph node by morphologic and immunophenotypic analyses, and molecular studies by DNA sequencing. D-2HG was measured in both tumoral tissue and in pre-treatment plasma by liquid chromatography-tandem mass spectrometry. Results: While D-2HG was markedly elevated in the tissue sample, its level in plasma was normal. We discuss this discordant D-2HG result within the context of previously reported discordant 2HG results in other IDH mutated tumors, and its implication for using circulating D-2HG as a biomarker of IDH mutation. In addition, this case also harbored mutations in RHOA, TET2, and TP53. The molecular pathogenesis is briefly discussed. Conclusion: While our case suggests that circulating D-2HG is not a reliable marker of IDH mutation in AITL, more cases need to be studied to arrive at a definite conclusion.     

Wound healing effect of methanolic leaf extract of Napoleona vogelii(Family:Lecythidaceae) in rats

Objective:To investigate the wound healing properly of Napoleona vogelii leaf extract in folkloric medicine.Methods:Roth sexes of adult albino rats(n=25) were used in this study and another group(n=30) were subjected to acute toxicity test(LD_(50)) of the plant extract.For the LD_(50),three randomized groups of 5 rats were first treated with 10,100,1 000 mg/kg body weight(bw),orally.This w as followed by a second treatment of 1500,3000,and 5 000 mg/kg bw of the leaf extract with continual monitoring of the animals for mortality or non-mortality.Incision wounds(1.3cm) were created on the skin of five groups of 5 rals using surgical blade under anesthesia.The first group was topically treated with petroleum jelly alone,group 2 was topically applied 400 mg/mL w/v of the reference drug,Neobaein,while group 3-5 were topically treated with 5-50 mg/mL w/v of the plant extract,respectively.Results:The percentage yield of the extract was 49.80%w/w dry matter.The phytochemical analysis revealed several bioactive constituents including glycosides,tannins,alkaloids,perpenoids.saponins,steroids,proteins,and carbohydrates.The LD_(50) was beyond our experimental limit and was not determined.Increased concentrations(5,20,and 50mg/mL w/v) of the extract had significant(ANOVA,P0.05) healing effect on the incision wounds giving rise to 125%-140% while treatmentawith Neobacin resulted in 150% healing effect on the third treatment regimen compared to the control(100%).Conclusions:These data indicate that Napoleona vogelii leaf extract contains potent bioactive compounds containing wound healing activity,substantiating its use as a wound healer in folkloric medicine.     

Longitudinal Impact of a Randomized Clinical Trial to Improve Family Function,Reduce Maternal Stress and Improve Child Outcomes in Families of Children with ADHD

Objective Evaluate the efficacy of a 12 month nursing case-management intervention over a period of 18 months, 6 months after the end of intervention, for families of children attention deficit hyperactivity disorder (ADHD). Methods Mother and child dyads were enrolled to participate in a randomized controlled clinical trial. Children were 4–18 years old. Data were collected at baseline, 6, 12, and 18 months or 6 months after the termination of direct intervention. Longitudinal analyses, using generalized estimating equations, were conducted to assess change in study outcomes relating to family function, maternal stress, and child behavior over the 18 month period. Results Compared to control families, some family function outcomes were moderately improved in the intervention group. In particular, intervention families demonstrated substantial improvement in implementing family behavior controls (p value?=?0.038) and improvement in family satisfaction (not statistically significant p?=?0.062). Although there was improvement in the overall family function measure there was not a statistically significant difference between groups. Maternal stress and child behavior outcomes were not significantly different between control and intervention groups by the end of the intervention. Conclusions for Practice Addressing ADHD is complex and requires the assessment of comorbidities that might exacerbate negative behavior. Our findings support the latest American Academy of Pediatrics guidelines to use behavioral therapy as the first line of treatment in young children. Nursing case-management interventions that provide direct family education and improve family function, especially with respect to providing structure and behavior control, may complement and facilitate behavioral therapy for treatment of ADHD and improving child behavior.     

Combining Self-Affirmation and Implementation Intentions: Evidence of Detrimental Effects on Behavioral Outcomes

Background

There is limited evidence that self-affirmation manipulations can promote health behavior change.

Purpose

The purpose of this study was to explore whether the efficacy of a self-affirmation manipulation at promoting exercise could be enhanced by an implementation intention intervention.

Methods

Participants (Study 1?N?=?120, Study 2?N?=?116) were allocated to one of four conditions resulting from the two (self-affirmation manipulation: no affirmation, affirmation) by two (implementation intention manipulation: no implementation intention, implementation intention) experimental design. Exercise behavior was assessed 1 week post-intervention.

Results

Contrary to prediction, those participants receiving both manipulations were significantly less likely to increase the amount they exercised compared to those receiving only the self-affirmation manipulation.

Conclusion

Incorporating an implementation intention manipulation alongside a self-affirmation manipulation had a detrimental effect on exercise behavior; participants receiving both manipulations exercised significantly less in the week following the intervention.     

The Unique Binding Mode of Laulimalide to Two Tubulin Protofilaments

Laulimalide, a cancer chemotherapeutic in preclinical development, has a unique binding site located on two adjacent β‐tubulin units between tubulin protofilaments of a microtubule. Our extended protein model more accurately mimics the microtubule environment, and together with a 135 ns molecular dynamics simulation, identifies a new binding mode for laulimalide, which differs from the modes presented in work using smaller protein models. The new laulimalide–residue interactions that are computationally revealed explain the contacts observed via independent mass shift perturbation experiments. The inclusion of explicit solvent shows that many laulimalide–tubulin interactions are water mediated. The new contacts between the drug and the microtubule structure not only improve our understanding of laulimalide binding but also will be essential for efficient derivatization and optimization of this prospective cancer chemotherapy agent. Observed changes in secondary protein structure implicate the S7–H9 loop (M–loop) and H1′–S2 loop in the mechanism by which laulimalide stabilizes microtubules to exert its cytotoxic effects.     

Oxidative metabolism of the human eosinophil

We have compared the oxidative metabolism of human eosinophils (80%-90% purity) to that of neutrophils. Hexose monophosphate (HMP) shunt activity of eosinophils was higher than that of neutrophils under either resting or phagocytizing conditions. Eosinophil HMP shunt activity also was stimulated by phorbol myristate acetate, a membrane- active agent. Eosinophils showed a marked incorporation of 125I into trichloroacetic acid-insoluble material under resting conditions, which increased markedly during phagocytosis. Eosinophils likewise showed a greater reduction of nitroblue tetrazolium dye during phagocytosis than did neutrophils. Measurement of other parameters of oxidative metabolism indicated that eosinophils generated superoxide anion following phagocytosis and also elicited a burst of chemiluminescence similar to that observed during phagocytosis by neutrophils. Measurement of NADPH oxidase activity demonstrated that this enzyme was 3-6 times more active in fractions isolated from eosinophils than in corresponding fractions isolated from neutrophils; this was observed over a range of substrate concentrations. The eosinophil enzyme sedimented differently than the neutrophil enzyme with differential centrifugation; neither showed sedimentation characteristics of peroxidase. These data indicate that eosinophils possess a similar, although in some ways more potent, oxidative burst than neutrophils and are consistent with a role for NADPH oxidase in the initiation of that burst.     

Comparing within‐subject classification and regularization methods in fMRI for large and small sample sizes

In recent years, a variety of multivariate classifier models have been applied to fMRI, with different modeling assumptions. When classifying high‐dimensional fMRI data, we must also regularize to improve model stability, and the interactions between classifier and regularization techniques are still being investigated. Classifiers are usually compared on large, multisubject fMRI datasets. However, it is unclear how classifier/regularizer models perform for within‐subject analyses, as a function of signal strength and sample size. We compare four standard classifiers: Linear and Quadratic Discriminants, Logistic Regression and Support Vector Machines. Classification was performed on data in the linear kernel (covariance) feature space, and classifiers are tuned with four commonly‐used regularizers: Principal Component and Independent Component Analysis, and penalization of kernel features using L₁ and L₂ norms. We evaluated prediction accuracy (P) and spatial reproducibility (R) of all classifier/regularizer combinations on single‐subject analyses, over a range of three different block task contrasts and sample sizes for a BOLD fMRI experiment. We show that the classifier model has a small impact on signal detection, compared to the choice of regularizer. PCA maximizes reproducibility and global SNR, whereas L_p‐norms tend to maximize prediction. ICA produces low reproducibility, and prediction accuracy is classifier‐dependent. However, trade‐offs in (P,R) depend partly on the optimization criterion, and PCA‐based models are able to explore the widest range of (P,R) values. These trends are consistent across task contrasts and data sizes (training samples range from 6 to 96 scans). In addition, the trends in classifier performance are consistent for ROI‐based classifier analyses. Hum Brain Mapp 35:4499–4517, 2014. © 2014 Wiley Periodicals, Inc .