In vivo luminescent imaging of NF-κB activity and NF-κB-related serum cytokine levels predict pain sensitivities in a rodent model of peripheral neuropathy.

BACKGROUND: Methods for the detection of the temporal and spatial generation of painful symptoms are needed to improve the diagnosis and treatment of painful neuropathies and to aid preclinical screening of molecular therapeutics. METHODS: In this study, we utilized in vivo luminescent imaging of NF-κB activity and serum cytokine measures to investigate relationships between the NF-κB regulatory network and the presentation of painful symptoms in a model of neuropathy. RESULTS: The chronic constriction injury model led to temporal increases in NF-κB activity that were strongly and non-linearly correlated with the presentation of pain sensitivities (i.e. mechanical allodynia and thermal hyperalgesia). The delivery of NEMO-binding domain peptide reduced pain sensitivities through the inhibition of NF-κB activity in a manner consistent with the demonstrated non-linear relationship. Importantly, the combination of non-invasive measures of NF-κB activity and NF-κB-regulated serum cytokines produced a highly predictive model of both mechanical (R(2) = 0.86) and thermal (R(2) = 0.76) pain centred on the NF-κB regulatory network (NF-κB, IL-6, CXCL1). CONCLUSIONS: Using in vivo luminescent imaging of NF-κB activity and serum cytokine measures, this work establishes NF-κB and NF-κB-regulated cytokines as novel multivariate biomarkers of pain-related sensitivity in this model of neuropathy that may be useful for the rapid screening of novel molecular therapeutics.

The effect of cigarette smoking on anaerobiosis in the oral cavity.

Nineteen young adult male smokers were compared to 19 adult male nonsmokers to determine if cigarette smoking resulted in any changes to anaerobic bacteria in dental plaque, to intraoral oxidation-reduction potential (Eh) levels, or to intraoral pH. There was no statistical difference between smokers and nonsmokers in the proportion of anaerobic bacteria found in dental plaque. There were no significant differences between smokers and nonsmokers with respect to the resting Eh in the floor of the mouth nor in the Eh in the region of buccal surface of the upper molars. The smoking of one cigarette resulted in a dramatic fall in Eh in both intraoral regions and this occurred in all subjects, both smokers and nonsmokers. The magnitude of this fall in Eh was similar in both groups. There were also uniform increases in pH, but these pH changes were much smaller in magnitude.

Polyol metabolism by a caries-conducive Streptococcus: purification and properties of a nicotinamide adenine dinucleotide-dependent mannitol-1-phosphate dehydrogenase.

The mannitol-1-phosphate dehydrogenase (M1PDH) (EC 1.1.1.17) from Streptococcus mutans strain FA-1 was purified to approximately a 425-fold increase in specific activity with a 29% recovery of total enzyme units, using a combination of (i) streptomycin sulfate and ammonium sulfate precipitation and (ii) diethyl-aminoethyl-cellulose (DE-52), agarose A 0.5M, and agarose-nicotinamide adenine dinucleotide (NAD) affinity column chromatography. Polyacrylamide gel electrophoresis of the purified enzyme preparation showed a single protein component that coincided with a band of M1PDH activity. The enzyme had a molecular weight of approximately 45,000 and was stable for long periods of time when stored at -80 degrees C in the presence of beta-mercaptoethanol. Its activity was not affected by mono- or divalent cations, and high concentrations of ethylenedia-minetetraacetic acid were not inhibitory. The M1PDH catalyzed both the NAD-dependent oxidation of mannitol-1-phosphate and the reduced NAD (NADH)-dependent reduction of fructose-6-phosphate. The forward reaction was highly specific for mannitol-1-phosphate and NAD, whereas the reverse reaction was highly specific for NADH and fructose-6-phosphate. The K(m) values for mannitol-1-phosphate and NAD were 0.15 and 0.066 mM, respectively, and the K(m) values for fructose-6-phosphate and NADH were 1.66 and 0.016 mM, respectively. The forward and reverse reactions catalyzed by the M1PDH from S. mutans appeared to be under cellular control. Both adenosine 5'-triphosphate and fructose-6-phosphate were negative effectors of the forward reaction, whereas adenosine 5'-diphosphate served as a negative effector of the reverse reaction catalyzed by the enzyme.