Ganglioside GQ1b is a tetrasialoganglioside that contains two sialic acid residues linked to an inner galactose unit. It stimulates phosphorylation of several ecto-type protein kinase substrates on the surface of GOTO human neuroblastoma cells when used at a concentration of 5 nM. Ganglioside GQ1b promotes differentiation of murine embryonic stem cells (mESCs) to neuronal precursor and glial cells via activation of the ERK1/2 pathway. It also induces differentiation of murine keratinocytes through phosphoinositide turnover. Ganglioside GQ1b mixture contains ganglioside GQ1b molecular species with C18:1 and C20:1 sphingoid backbones.
Apoptolidin is an apoptosis inducer originally isolated from Nocardiopsis bacteria. It inhibits the mitochondrial F1FO ATPase (Ki = 4-5 μM). Apoptolidin selectively kills transformed glial cells without significantly affecting untransformed cells. It also has antibiotic and antifungal actions.
Ceramide phosphoethanolamine (CPE) is an analog of sphingomyelin that contains ethanolamine rather than choline as the head group. It is the principal membrane phospholipid in invertebrates such as Drosophila, which lacks sphingomyelin. It is only produced in small amounts in mammalian cells, accounting for approximately 0.02 mol% of total phospholipids in mouse testis and brain. In Drosophila, CPE is biosynthesized by CPE synthase from ceramide and cytidine diphosphate-ethanolamine in the Golgi lumen. In mammals, it is biosynthesized by sphingomyelin synthase 2 (SMS2) in the plasma membrane and by sphingomyelin synthase-related protein (SMSr) in the endoplasmic reticulum (ER). In Drosophila, CPE has a role in glial ensheathment of axons. Disrupting CPE synthesis by depleting SMSr in vitro in mammalian cells leads to an accumulation of ER ceramides, which are then mislocalized to the mitochondria, inducing apoptosis. However, ceramide levels are not altered in transgenic mice lacking SMSr catalytic activity. CPEs (bovine) is a mixture of CPEs with variable N-acyl chain lengths.
Reduced haloperidol is an active metabolite of haloperidol . It is formed via reduction of haloperidol by ketone reductase. Reduced haloperidol inhibits radioligand binding to sigma-1 and dopamine D2 receptors (Kis = 1.4 and 31 nM, respectively) and stimulates brain-derived neurotrophic factor (BDNF) secretion from CCF-SSTG1 and U87MG astrocytic glial cells. It also inhibits norepinephrine, dopamine, and serotonin (5-HT) reuptake (Kis = 21, 25, and 33 μM, respectively, in COS-7 cells expressing the human transporters). Reduced haloperidol (0.5 mg kg) increases latency to paw withdrawal in mouse models of capsaicin- but not force-induced mechanical hypersensitivity.
Potent and selective inhibitor of the glial glycine transporter GlyT1b (IC50 = 6.9 nM). Displays negligible activity at GlyT-2, adrenoreceptors, dopamine, 5HT receptors and noradrenaline, dopamine, 5HT and GABA transporters (pIC50 in vivo. Chue et al (2013) Glycine reuptake inhibition as a new therapeutic approach in schizophrenia: focus on the glycine transporter 1 (GlyT1). Curr.Pharm.Des. 19 1311 PMID:23194655 |Brown et al (2001) Discovery and SAR of org 24598-a selective glycine uptake inhibitor. Bioorg.Med.Chem.Lett. 11 2007 PMID:11454468 |Williams et al (2003) Development of a scintillation proximity assay for analysis of Na+ Cl- -dependent neurotransmitter transporter activity. Anal. Biochem. 321 31 PMID:12963052
PAQ is a neuroprotective agent. It protects dopaminergic neurons from cell death without inhibiting glial cell proliferation in a rat midbrain culture model of Parkinson's disease when used at a concentration of 10 μM. PAQ (25 or 50 mg/kg, twice per day) prevents loss of dopaminergic neurons in the substantia nigra in a mouse model of Parkinson's disease induced by MPTP.