Geldanamycin accelerated peripheral nerve regeneration in comparison to FK-506 in vivo

Sun, Hank H.; Saheb-Al-Zamani, Maryam; Yan, Yan; Hunter, Daniel A.; Mackinnon, Susan E.; Johnson, Philip J.

doi:10.1016/j.neuroscience.2012.07.026

Cited by 29 publications

(22 citation statements)

References 79 publications

(98 reference statements)

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“…This is different to what has been previously reported, and the widely accepted belief that DMSO is well tolerated at concentrations <10% (8, 16–19). In previous intravitreal in vivo studies (2–4, 7, 10–15, 19, 39, 40), the stock concentrations of DMSO administered are reported, although we have also quantified corresponding final vitreous concentration of 0.1, 0.2, 0.4, 0.7, 0.9, 1.4, and 2.3% (v/v) based on the DA rat vitreous volume of 55 μl. DMSO is also toxic to RGC‐5 cells in vitro, as demonstrated using fluorescently labeled annexin V, TUNEL, PI, MTT, and Hoechst as neuronal cell viability assays.…”

Section: Discussionmentioning

confidence: 99%

Unexpected low‐dose toxicity of the universal solvent DMSO

et al. 2013

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Dimethyl sulfoxide (DMSO) is an important aprotic solvent that can solubilize a wide variety of otherwise poorly soluble polar and nonpolar molecules. This, coupled with its apparent low toxicity at concentrations <10%, has led to its ubiquitous use and widespread application. Here, we demonstrate that DMSO induces retinal apoptosis in vivo at low concentrations (5 μl intravitreally dosed DMSO in rat from a stock concentration of 1, 2, 4, and 8% v/v). Toxicity was confirmed in vitro in a retinal neuronal cell line, at DMSO concentrations >1% (v/v), using annexin V, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and AlamarBlue cell viability assays. DMSO concentrations >10% (v/v) have recently been reported to cause cellular toxicity through plasma membrane pore formation. Here, we show the mechanism by which low concentrations (2-4% DMSO) induce caspase-3 independent neuronal death that involves apoptosis-inducing factor (AIF) translocation from mitochondria to the nucleus and poly-(ADP-ribose)-polymerase (PARP) activation. These results highlight safety concerns of using low concentrations of DMSO as a solvent for in vivo administration and in biological assays. We recommend that methods other than DMSO are employed for solubilizing drugs but, where no alternative exists, researchers compute absolute DMSO final concentrations and include an untreated control group in addition to DMSO vehicle control to check for solvent toxicity.

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Section: Discussionmentioning

confidence: 99%

Unexpected low‐dose toxicity of the universal solvent DMSO

et al. 2013

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“…Geldanamycin: Data on the developmental toxicity of geldanamycin in vivo were not found, but effects on neurodifferentiation were observed in rats by Sun et al (2012) at a dose of 0.2 mg/kg/day. Extrapolation of pharmacokinetics data from Supko et al (Supko et al 1995) allowed then the calculation of the Cmax and of the respective NEC.…”

Section: Resultsmentioning

confidence: 99%

“…The NEC of geldanamycin was 8.9 nM in N2 medium and 198 nM in BHK medium when modeled from the rat study described by Sun et al (2012). In our in vitro system, geldanamycin showed an EC20 of 1–10 nM.…”

Section: Resultsmentioning

confidence: 99%

“…We used the study of (Sun et al 2012) to define a dose that is acting on neurons in vivo. A GA dose of 0.2 mg/kg/day affected nerve recovery in a model based on Thy1-GFP transgenic rats, in which the green fluorescent protein GFP was expressed under the neuron-specific promoter Thy1, allowing to determine the rate of axon regeneration after a nerve injury.…”

Section: Methodsmentioning

confidence: 99%

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Fingerprinting of neurotoxic compounds using a mouse embryonic stem cell dual luminescence reporter assay

et al. 2016

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Identification of neurotoxic drugs and environmental chemicals is an important challenge. However, only few tools to address this topic are available. The aim of this study was to develop a neurotoxicity/developmental neurotoxicity (DNT) test system, using the pluripotent mouse embryonic stem cell line CGR8 (ESCs). The test system uses ESCs at two differentiation stages: undifferentiated ESCs and ESC-derived neurons. Under each condition, concentration–response curves were obtained for three parameters: activity of the tubulin alpha 1 promoter (typically activated in early neurons), activity of the elongation factor 1 alpha promoter (active in all cells), and total DNA content (proportional to the number of surviving cells). We tested 37 compounds from the ESNATS test battery, which includes polypeptide hormones, environmental pollutants (including methylmercury), and clinically used drugs (including valproic acid and tyrosine kinase inhibitors). Different classes of compounds showed distinct concentration–response profiles. Plotting of the lowest observed adverse effect concentrations (LOAEL) of the neuronal promoter activity against the general promoter activity or against cytotoxicity, allowed the differentiation between neurotoxic/DNT substances and non-neurotoxic controls. Reporter activity responses in neurons were more susceptible to neurotoxic compounds than the reporter activities in ESCs from which they were derived. To relate the effective/toxic concentrations found in our study to relevant in vivo concentrations, we used a reverse pharmacokinetic modeling approach for three exemplary compounds (teriflunomide, geldanamycin, abiraterone). The dual luminescence reporter assay described in this study allows high-throughput, and should be particularly useful for the prioritization of the neurotoxic potential of a large number of compounds.Electronic supplementary materialThe online version of this article (doi:10.1007/s00204-016-1690-2) contains supplementary material, which is available to authorized users.

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“…FK506 is a drug that not only demonstrates neuro-regenerative properties but also immunosuppressive characteristics. There are numerous in vivo small animal studies that have demonstrated improved rates of nerve regeneration with systemic delivery of FK506 (Grand, Myckatyn, Mackinnon, & Hunter, 2002;Sun et al, 2012;Udina, Rodriguez et al, 2004;Whitlock et al, 2010;W. This drug has also been observed to have neuroregenerative properties when administered after peripheral nerve injuries (Jost, Doolabh, Mackinnon, Lee, & Hunter, 2000).…”

mentioning

confidence: 99%

Drug‐delivering nerve conduit improves regeneration in a critical‐sized gap

Labroo

Hilgart

Davis

et al. 2018

Biotech & Bioengineering

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Autologous nerve grafts are the current "gold standard" for repairing large nerve gaps. However, they cause morbidity at the donor nerve site and only a limited amount of nerve can be harvested. Nerve conduits are a promising alternative to autografts and can act as guidance cues for the regenerating axons, without the need to harvest donor nerve. Separately, it has been shown that localized delivery of GDNF can enhance axon growth and motor recovery. FK506, an FDA approved small molecule, has also been shown to enhance peripheral nerve regeneration. This paper describes the design of a novel hole-based drug delivery apparatus integrated with a polytetrafluoroethylene (PTFE) nerve conduit for controlled local delivery of a protein such as GDNF or a small molecule such as FK506. The PTFE devices were tested in a diffusion chamber, and the bioactivity of the released media was evaluated by measuring neurite growth of dorsal root ganglions (DRGs) exposed to the released drugs. The drug delivering nerve guide was able to release bioactive concentrations of FK506 or GDNF. Following these tests, optimized drug releasing nerve conduits were implanted across 10 mm sciatic nerve gaps in a BL6 yellow fluorescent protein (YFP) mouse model, where they demonstrated significant improvement in muscle mass, compound muscle action potential, and axon myelination in vivo as compared with nerve conduits without the drug. The drug delivery nerve guide could release drug for extended periods of time and enhance axon growth in vitro and in vivo.

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Geldanamycin accelerated peripheral nerve regeneration in comparison to FK-506 in vivo

Cited by 29 publications

References 79 publications

Unexpected low‐dose toxicity of the universal solvent DMSO

Unexpected low‐dose toxicity of the universal solvent DMSO

Fingerprinting of neurotoxic compounds using a mouse embryonic stem cell dual luminescence reporter assay

Drug‐delivering nerve conduit improves regeneration in a critical‐sized gap

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