Discovery of a neuroprotective chemical, (S)-N-(3-(3,6-dibromo-9H-carbazol-9-yl)-2-fluoropropyl)-6-methoxypyridin-2-amine [(-)-P7C3-S243], with improved druglike properties.

(-)-P7C3-S243 is a neuroprotective aminopropyl carbazole with improved druglike properties compared with previously reported compounds in the P7C3 class. It protects developing neurons in a mouse model of hippocampal neurogenesis and protects mature neurons within the substantia nigra in a mouse model of Parkinson's disease. A short, enantioselective synthesis provides the neuroprotective agent in optically pure form. It is nontoxic, orally bioavailable, metabolically stable, and able to cross the blood-brain barrier. As such, it represents a valuable lead compound for the development of drugs to treat neurodegenerative diseases and traumatic brain injury.

Neuroprotective efficacy of aminopropyl carbazoles in a mouse model of amyotrophic lateral sclerosis.

We previously reported the discovery of P7C3, an aminopropyl carbazole having proneurogenic and neuroprotective properties in newborn neural precursor cells of the hippocampal dentate gyrus. We have further found that chemicals having efficacy in this in vivo screening assay also protect dopaminergic neurons of the substantia nigra following exposure to the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, a mouse model of Parkinson disease. Here, we provide evidence that an active analog of P7C3, known as P7C3A20, protects ventral horn spinal cord motor neurons from cell death in the G93A-SOD1 mutant mouse model of amyotrophic lateral sclerosis (ALS). P7C3A20 is efficacious in this model when administered at disease onset, and protection from cell death correlates with preservation of motor function in assays of walking gait and in the accelerating rotarod test. The prototypical member of this series, P7C3, delays disease progression in G93A-SOD1 mice when administration is initiated substantially earlier than the expected time of symptom onset. Dimebon, an antihistaminergic drug with significantly weaker proneurogenic and neuroprotective efficacy than P7C3, confers no protection in this ALS model. We propose that the chemical scaffold represented by P7C3 and P7C3A20 may provide a basis for the discovery and optimization of pharmacologic agents for the treatment of ALS.

Tumor necrosis factor is critical for cytolytic T cell activity against allospecific hepatocytes and splenic targets in major histocompatibility complex class I disparate graft versus host disease.

The present studies determined the role of tumor necrosis factor (TNF)/tumor necrosis factor receptor (TNFR) interactions on cytolytic (CTL) activity of splenic and intrahepatic lymphocytes (IHL) isolated from mice undergoing graft versus host disease, induced by transfer of B6 T cells to major histocompatibility complex (MHC) class I disparate bm1 × B6 F1 mice. Allospecific killing of anti-H-2(bm1) splenic and hepatocyte targets was assessed by 4-h (51)Cr release and 16-h DNA lysis assays, respectively, utilizing spleen cells (SpC) and IHL isolated (1) from sublethally irradiated bm1 × B6 F1 who had received B6 spleen and bone marrow cells, and a control adenovirus (Adv-ßgal) or a TNF inhibitor expressing adenovirus (Adv-TNFi), or (2) from bm1 × B6 F1 recipients of B6, B6.129-Tnfrsf1a(tm1Mak)/J (TNFR1(-/-)), B6.129S2-Tnfrsf1b(tm1Mwm)/J (TNFR2(-/-)), or B6.129S-Tnfrsf1a(tm1Imx) Tnfrsf1b(tm1Imx)/J (TNFR(-/-)) SpC and bone marrow cells, or (3) from in vitro-activated SpC. Splenic and IHL from bone marrow transplant recipients who had received Adv-TNFi at the time of transplant displayed lower allospecific CTL activity than controls. Addition of TNFR-Ig or a TNF antibody before the CTL activity assay further reduced allospecific killing against bm1 SpC blast targets. Both TNF/TNFR1 and TNF/TNFR2 interactions were critical for the development of optimal CTL activity against allospecific hepatocyte targets. Further, TNFR1- and TNFR2-deficient SpC from MHC class I disparate mixed lymphocyte cultures displayed lower CTL activity and expression of effector molecules than control B6 SpC. TNF/TNFR interactions were critical for the development of optimal CTL activity of IHL and splenic cytotoxic T cells against MHC class I disparate SpC blast and hepatocyte targets in MHC class I disparate graft versus host disease.