Onchocerca volvulus Molting Inhibitors Identified through Scaffold Hopping

The anthelmintic closantel has shown promise in abrogating the L3 molting of Onchocerca volvulus, the causative agent of the infectious disease onchocerciasis. In our search for alternative scaffolds, we utilized a fragment replacement/modification approach to generate novel chemotypes with improved chitinase inhibitory properties. Further evaluation of the compounds unveiled the potential of urea-tropolones as potent inhibitors of <i>O. volvulus</i> L3 molting

Influencing Antibody-Mediated Attenuation of Methamphetamine CNS Distribution through Vaccine Linker Design

Active vaccination examining a single hapten engendered with a series of peptidic linkers has resulted in the production of antimethamphetamine antibodies. Given the limited chemical complexity of methamphetamine, the structure of the linker species embedded within the hapten could have a substantial effect on the ultimate efficacy of the resulting vaccines. Herein, we investigate linker effects by generating a series of methamphetamine haptens that harbor a linker with varying amino acid identity, peptide length, and associated carrier protein. Independent changes in each of these parameters were found to result in alterations in both the quantity and quality of the antibodies induced by vaccination. Although it was found that the consequence of the linker design was also dependent on the identity of the carrier protein, we demonstrate overall that the inclusion of a short, structurally simple, amino acid linker benefits the efficacy of a methamphetamine vaccine in limiting brain penetration of the free drug

Selective Gelatinase Inhibitor Neuroprotective Agents Cross the Blood-Brain Barrier

SB-3CT, a potent and selective inhibitor of matrix metalloproteinase-2 and -9, has shown efficacy in several animal models of neurological diseases. One of the greatest challenges in the development of therapeutics for neurological diseases is the inability of drugs to cross the blood-brain barrier. A sensitive bioanalytical method based on ultraperformance liquid chromatography with multiple-reaction monitoring detection was developed to measure levels of SB-3CT, its active metabolite, the α-methyl analogue, and its <i>p</i>-hydroxy metabolite in plasma and brain. The compounds are rapidly absorbed and are readily distributed to the brain. The pharmacokinetic properties of these gelatinase inhibitors and the efficacy shown by SB-3CT in animal models of stroke, subarachnoid hemorrhage, and spinal cord injury indicate that this class of compounds holds considerable promise in the treatment of diseases of the central nervous system

Water-Soluble MMP‑9 Inhibitor Prodrug Generates Active Metabolites That Cross the Blood–Brain Barrier

MMP-9 plays a detrimental role in the pathology of several neurological diseases and, thus, represents an important target for intervention. The water-soluble prodrug ND-478 is hydrolyzed to the active MMP-9 inhibitor ND-322, which in turn is <i>N</i>-acetylated to the even more potent metabolite ND-364. We used a sensitive bioanalytical method based on ultraperformance liquid chromatography with multiple-reaction monitoring detection to measure levels of ND-478, ND-322, and ND-364 in plasma and brain after administration of ND-478 and the metabolites. ND-478 did not cross the blood–brain barrier, as was expected; however the active metabolites ND-322 and ND-364 distributed to the brain. The active compound after administration of either ND-478 or ND-322 is likely ND-364. ND-322 is <i>N</i>-acetylated in both brain and liver, but it is so metabolized preferentially in liver. Since <i>N</i>-acetyltransferases involved in the metabolism of ND-322 to ND-364 are polymorphic, direct administration of the <i>N</i>-acetylated ND-364 would achieve the requisite therapeutic levels in the brain

A Chemical Biological Strategy to Facilitate Diabetic Wound Healing

A complication of diabetes is the inability of wounds to heal in diabetic patients. Diabetic wounds are refractory to healing due to the involvement of activated matrix metalloproteinases (MMPs), which remodel the tissue resulting in apoptosis. There are no readily available methods that identify active unregulated MMPs. With the use of a novel inhibitor-tethered resin that binds exclusively to the active forms of MMPs, coupled with proteomics, we quantified MMP-8 and MMP-9 in a mouse model of diabetic wounds. Topical treatment with a selective MMP-9 inhibitor led to acceleration of wound healing, re-epithelialization, and significantly attenuated apoptosis. In contrast, selective pharmacological inhibition of MMP-8 delayed wound healing, decreased re-epithelialization, and exhibited high apoptosis. The MMP-9 activity makes the wounds refractory to healing, whereas that of MMP-8 is beneficial. The treatment of diabetic wounds with a selective MMP-9 inhibitor holds great promise in providing heretofore-unavailable opportunities for intervention of this disease

Cognitive deficits detected in the Morris water maze (MWM) at adulthood after pediatric TBI, are unaffected by gelatinase inhibition.

<p>(A) During the visible sessions, quantification of latency to reach the platform revealed an impairment in task learning by TBI mice compared to sham controls (multivariate ANOVA overall effect of TBI, **p<0.01). (B) During hidden platform sessions, injured mice also showed a greater latency to reach the platform as compared to sham controls (overall effect of TBI, ***p<0.001), indicating an impairment in spatial memory. Cumulative distance to the target was also quantified as an alternative outcome measure (C-D), which similarly detected impairments in task performance and spatial memory in TBI mice compared to sham controls (overall effect of TBI, **p<0.01). (E) Probe trial performance was quantified as cumulative distance to the target. Injured mice traveled a greater distance to reach the target quadrant compared to sham controls (RM ANOVA, overall effect of TBI, **p<0.01) (n = 15/group). Bars represent mean + sem and values represent mean ± sem.</p

Acute gelatinase inhibitor does not attenuate deficits in social behavior at adulthood after pediatric TBI.

<p>(A) Social investigation was quantified by the resident-intruder paradigm, revealing that TBI mice as compared to sham controls spent less time investigating a naïve intruder mouse (2-way ANOVA overall effect of TBI, **p<0.01). (B) In the three-chamber social approach task (stage 2), all mice showed an overall preference for sociability with stimulus mouse 1 compared to the empty chamber (2-way RM ANOVA overall effect of chamber, p = 0.0003). (C) Stage 3 of the three-chamber task tested social novelty. Here, sham-operated mice revealed a preference for a novel stimulus mouse compared to the now-familiar mouse (2-way RM ANOVA interaction, p = 0.0055; subsequent Sidak’s post-hoc tests, ***p<0.001, ****p<0.0001 as indicated graphically). In contrast, TBI mice showed a lack of of social memory (n.s. by Sidak's post-hoc) (n = 15/group). Bars represent mean + sem.</p

Gelatinase inhibition with <i>p</i>-OH SB-3CT does not attenuate extensive injury-induced loss of cortical and hippocampal structures.

<p>Volumetric estimates spanning Bregma 1.5 to -3.8mm in the cortex (Ctx; A), hippocampus (Hpc; B) and dentate gyrus (DG; C) revealed injury-induced reductions (unpaired t-tests *p<0.05, **p<0.01, ***p<0.001, and ****p<0.0001 as indicated graphically; n = 11–15/group). (D) Unbiased cell counts performed in the ipsilateral DG found similar numbers of surviving neurons in the upper and lower blades of injured mice independent of drug treatment (n = 8–9/group). Bars represent mean + sem.</p

Concentrations of <i>p</i>-OH SB-3CT after multiple-dose s.c. administration.

<p>^<i>a</i> Concentrations in pmol/mg tissue</p><p>^<i>b</i> Concentrations in μM</p><p>^<i>c</i> NQ = not quantifiable</p><p>AUC = area under the curve</p><p>^<i>d</i><i>AUC</i> in pmol·min/mg for brain and in μM·min for plasma</p><p>Concentrations of <i>p</i>-OH SB-3CT after multiple-dose s.c. administration.</p

Enhanced gelatinases detected at 48 h after TBI.

<p>(A) Gelatin zymography from representative brain lysates indicates increased expression of MMP-9 and MMP-2 at 48 h post-injury as compared to sham controls. The pro-forms of MMP-9 and MMP-2 were detected at ~105 and 72 kDa, respectively. Purified human MMP-2 and MMP-9 were used as standards. (B) Quantification of band intensity revealed a robust increase in the pro-enzyme forms of MMP-2 and (C) MMP-9, as well as increases in the active enzyme forms after TBI compared to sham (n = 6 per group; unpaired t-tests, *p<0.05, **p<0.01 and ***p<0.001, TBI compared to sham). Bars represent mean + sem.</p