Selective Inhibition of the Mitochondrial Permeability Transition Pore Protects against Neurodegeneration in Experimental Multiple Sclerosis

The mitochondrial permeability transition pore is a recognized drug target for neurodegenerative conditions such as multiple sclerosis and for ischemia-reperfusion injury in the brain and heart. The peptidylprolyl isomerase, cyclophilin D (CypD, PPIF), is a positive regulator of the pore, and genetic down-regulation or knock-out improves outcomes in disease models. Current inhibitors of peptidylprolyl isomerases show no selectivity between the tightly conserved cyclophilin paralogs and exhibit significant off-target effects, immunosuppression, and toxicity. We therefore designed and synthesized a new mitochondrially targeted CypD inhibitor, JW47, using a quinolinium cation tethered to cyclosporine. X-ray analysis was used to validate the design concept, and biological evaluation revealed selective cellular inhibition of CypD and the permeability transition pore with reduced cellular toxicity compared with cyclosporine. In an experimental autoimmune encephalomyelitis disease model of neurodegeneration in multiple sclerosis, JW47 demonstrated significant protection of axons and improved motor assessments with minimal immunosuppression. These findings suggest that selective CypD inhibition may represent a viable therapeutic strategy for MS and identify quinolinium as a mitochondrial targeting group for in vivo use.

Beneficial effect of macrophage activating agent NK-4 on Thai HIV-infected patients

BACKGROUND

We examined the effect of NK-4 (4,4'-[3-[2-(1-ethyl-4(1H)-quinolinylidene) ethylidene] propenylene] bis(-ethylquinolinium iodide)) on the clinical course of Thai HIV-infected patients receiving antiretroviral drugs.

PATIENTS AND METHODS

Twelve subjects with CD4 count < 500/mm3 were enrolled to receive 0.5 mg of NK-4 orally once daily for 8 weeks and then twice daily during the follow-up.

RESULTS

Most patients showed vitality, increased appetite, stable body-weight, increased CD4 counts and no serious adverse effects due to viral load. We suggest that the increased CD4 counts are due to the macrophage activating effect of NK-4. The patients with increased CD4 counts showed lower alpha-N-acetylgalactosaminidase (alpha-NaGalase) activity than those with decreased CD4 counts.

CONCLUSION

These results suggest that the macrophage activating agent NK-4, as an inexpensive and safe drug for HIV-infected patients, may play a beneficial role in the clinical treatment of HIV-infected patients.

Therapeutic effects of some antihaematozoal drugs against Haemoproteus columbae in domestic pigeons

Three antihaematozoal drugs were tested for the treatment of pigeons naturally infected with Haemoproteus columbae. Butalex (Buparvaquone) was found effective against the parasite either by using the recommended dose (R. D.) or the double (D. D.) dosis. The R. D. of Berenil (Diminazene aceturate) was not effective while the D. D. reduced the number of gametocytes circulating in the infected blood. Triquine was found very toxic to the pigeons both the R. D. and the D. D.

Microvascular response to local application of dequalinium chloride. A vital microscopical study of hamster's cheek pouch and a microangiographic study of rabbit's ear

Dequalinium chloride is a topical antiseptic, whose use may be attended by skin necrosis. Since microcirculatory changes are an early and distinct manifestation of tissue injury, the tissue damaging effect of dequalinium chloride on the microcirculation was examined. The immediate vascular reactions were studied by vital microscopy, of the hamster cheek pouch and the late effects were visualized by microangiography of the rabbit ear. An aqueous solution of dequalinium chloride in concentrations well below those used in clinical practice induced severe microcirculatory disturbances.