Cellular Pharmacology of the D- and L-Enantiomers of β-5-o-Carboranyl-2′-deoxyuridine

Abstract

The cellular pharmacology of the D- and L-enantiomers of β-5-o-carboranyl-2′-deoxyuridine (CDU), compounds designed for boron neutron capture therapy (BNCT), were studied using human CEM lymphoblast and U-251 glioblastoma cells, at a physiologically achievable concentration (1 μM). Accumulation of the enantiomers was rapid and indistinguishable, reaching cellular concentrations > 40-fold higher than extracellular levels, with ～5% persisting in cells after incubation in fresh medium for more than 2 hr. Uptake was not affected by nucleoside uptake inhibitors, but was inhibited by the purine base uptake inhibitor papaverine.     

Photobiomodulation Induced by 670 nm Light Ameliorates MOG35-55 Induced EAE in Female C57BL/6 Mice: A Role for Remediation of Nitrosative Stress

Background

Experimental autoimmune encephalomyelitis (EAE) is the most commonly studied animal model of multiple sclerosis (MS), a chronic autoimmune demyelinating disorder of the central nervous system. Immunomodulatory and immunosuppressive therapies currently approved for the treatment of MS slow disease progression, but do not prevent it. A growing body of evidence suggests additional mechanisms contribute to disease progression. We previously demonstrated the amelioration of myelin oligodendrocyte glycoprotein (MOG)-induced EAE in C57BL/6 mice by 670 nm light-induced photobiomodulation, mediated in part by immune modulation. Numerous other studies demonstrate that near-infrared/far red light is therapeutically active through modulation of nitrosoxidative stress. As nitric oxide has been reported to play diverse roles in EAE/MS, and recent studies suggest that axonal loss and progression of disability in MS is mediated by nitrosoxidative stress, we investigated the effect of 670 nm light treatment on nitrosative stress in MOG-induced EAE.

Methodology

Cell culture experiments demonstrated that 670 nm light-mediated photobiomodulation attenuated antigen-specific nitric oxide production by heterogenous lymphocyte populations isolated from MOG immunized mice. Experiments in the EAE model demonstrated down-regulation of inducible nitric oxide synthase (iNOS) gene expression in the spinal cords of mice with EAE over the course of disease, compared to sham treated animals. Animals receiving 670 nm light treatment also exhibited up-regulation of the Bcl-2 anti-apoptosis gene, an increased Bcl-2:Bax ratio, and reduced apoptosis within the spinal cord of animals over the course of disease. 670 nm light therapy failed to ameliorate MOG-induced EAE in mice deficient in iNOS, confirming a role for remediation of nitrosative stress in the amelioration of MOG-induced EAE by 670 nm mediated photobiomodulation.

Conclusions

These data indicate that 670 nm light therapy protects against nitrosative stress and apoptosis within the central nervous system, contributing to the clinical effect of 670 nm light therapy previously noted in the EAE model.     

Effects of Diet Composition on Postprandial Energy Availability during Weight Loss Maintenance

Background

The major circulating metabolic fuels regulate hunger, and each is affected by dietary composition. An integrated measure of postprandial energy availability from circulating metabolic fuels may help inform dietary recommendations for weight maintenance after weight loss.

Aim

We examined the effect of low-fat (LF, 60% of energy from carbohydrate, 20% fat, 20% protein), low-glycemic index (LGI, 40%–40%-20%), and very low-carbohydrate (VLC, 10%–60%-30%) diets on total postprandial metabolic fuel energy availability (EA) during weight loss maintenance.

Methods

Eight obese young adults were fed a standard hypocaloric diet to produce 10–15% weight loss. They were then provided isocaloric LF, LGI, and VLC diets in a randomized crossover design, each for a 4-week period of weight loss maintenance. At the end of each dietary period, a test meal representing the respective diet was provided, and blood samples were obtained every 30 minutes for 5 hours. The primary outcome was EA, defined as the combined energy density (circulating level×relative energy content) of glucose, free fatty acids, and β-hydroxybutyrate. Secondary outcomes were individual metabolic fuels, metabolic rate, insulin, glucagon, cortisol, epinephrine, and hunger ratings. Respiratory quotient was a process measure. Data were analyzed by repeated-measures analysis of variance, with outcomes compared in the early (30 to 150 min) and late (180 to 300 min) postprandial periods.

Results

EA did not differ between the test meals during the early postprandial period (p = 0.99). However, EA in the late postprandial period was significantly lower after the LF test meal than the LGI (p<0.0001) and VLC (p<0.0001) test meals. Metabolic rate also differed in the late postprandial period (p = 0.0074), with higher values on the VLC than LF (p = 0.0064) and LGI (p = 0.0066) diets.

Conclusion

These findings suggest that an LF diet may adversely affect postprandial EA and risk for weight regain during weight loss maintenance.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00315354","term_id":"NCT00315354"}}NCT00315354     

Angiogenesis at the interface between basic and clinical research

The field of antiangiogenesis has shown a remarkably rapid evolution from the discovery at the bench to translation into the clinic. Currently a wide variety of compounds are in clinical trial as inhibitors of angiogenesis, and new compounds are being frequently added. The target cell of most angiogenesis inhibitors is the endothelial cell, with inhibitors that selectively affect a number of endothelial cell functions acquired during angiogenesis, including activation, proliferation, migration, invasion and survival. The endothelial cell may also be targeted by chemotherapeutic agents currently in use. The high doses and intermittent treatment schedules used to fight resistant tumor cells may be altered towards lower doses and chronic administration to obtain selective inhibition of angiogenic factor-stimulated endothelial cells as adjuvant therapy. Finally, gene therapy is a promising route for the delivery of novel protein inhibitors of angiogenesis, and is actively being investigated.     

Impaired host defense to infection and Toll-like receptor 2-independent killing of Borrelia burgdorferi clinical isolates in TLR2-deficient C3H/HeJ mice

To investigate the role of Toll-like receptor 2 (TLR2)-mediated signaling in host innate defense and development of Lyme disease, the pathogenicity of Borrelia burgdorferi sensu stricto clinical isolates representing two distinct genotypes (RST1 and RST3A) was assessed in TLR2(-/-) C3H/HeJ mice. All TLR2(-/-) mice infected with a B. burgdorferi RST1 isolate developed severe arthritis. The numbers of spirochetes in heart, joint and ear biopsy specimens were significantly higher in TLR2(-/-) mice than in wild-type mice similarly infected as determined by real-time quantitative polymerase chain reaction. Interestingly, despite the higher spirochete levels in heart tissues, milder carditis was observed in TLR2(-/-) than in wild-type mice infected with this RST1 isolate (P=0.02). By contrast, no positive cultures were obtained from any of the blood and tissue specimens from TLR2(-/-) mice inoculated with two RST3A clinical isolates. The data suggest that there is impaired host innate defense against infection and TLR2-independent killing of B. burgdorferi clinical isolates in TLR2-deficient C3H/HeJ mice.