Omigapil

The positive effect of levodopa in the treatment of Parkinson's disease, although it is limited in time and has severe side effects, has encouraged the scientific community to look for new drugs that can stop the neurodegenerative process or even regenerate the neuromelanin-containing dopaminergic nigrostriatal neurons. Successful preclinical studies with coenzyme Q10, mitoquinone, isradipine, nilotinib, TCH346, neurturin, zonisamide, deferiprone, prasinezumab, and cinpanemab prompted clinical trials. However, these failed and after more than 50 years levodopa continues to be the key drug in the treatment of the disease, despite its severe side effects after 4-6 years of chronic treatment. The lack of translated successful results obtained in preclinical investigations based on the use of neurotoxins that do not exist in the human body as new drugs for Parkinson's disease treatment is a big problem. In our opinion, the cause of these failures lies in the experimental animal models involving neurotoxins that do not exist in the human body, such as 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and 6-hydroxydopamine, that induce a very fast, massive and expansive neurodegenerative process, which contrasts with the extremely slow one of neuromelanin-containing dopaminergic neurons. The exceedingly slow progress of the neurodegenerative process of the nigrostriatal neurons in idiopathic Parkinson's patients is due to (i) a degenerative model in which the neurotoxic effect of an endogenous neurotoxin affects a single neuron, (ii) a neurotoxic event that is not expansive and (iii) the fact that the neurotoxin that triggers the neurodegenerative process is produced inside the neuromelanin-containing dopaminergic neurons. The endogenous neurotoxin that fits this degenerative model involving one single neuron at a time is aminochrome, since it (i) is generated within neuromelanin-containing dopaminergic neurons, (ii) does not cause an expansive neurotoxic effect and (iii) triggers all the mechanisms involved in the neurodegenerative process of the nigrostriatal neurons in idiopathic Parkinson's disease. In conclusion, based on the hypothesis that the neurodegenerative process of idiopathic Parkinson's disease corresponds to a single-neuron neurodegeneration model, we must search for molecules that increase the expression of the neuroprotective enzymes DT-diaphorase and glutathione transferase M2-2. It has been observed that the activation of the Kelch-like ECH-associated protein 1/nuclear factor (erythroid-derived 2)-like 2 pathway is associated with the transcriptional activation of the DT-diaphorase and glutathione transferase genes.

Mammalian sterile 20-like kinase 1 (MST1) is found to promote neuronal apoptosis. Protein-L-isoaspartate (D-aspartate) O-methyltransferase (PCMT1), an anti-apoptosis factor, was recently identified as an MST1-interacting protein. This study aims to explore the potential role of PCMT1 in reducing MST1-induced neuronal apoptosis after subarachnoid hemorrhage (SAH) in rats. One hundred ninety-eight male Sprague-Dawley rats were used. An exogenous PCMT1 agonist, CGP 3466B, was injected subcutaneously 1 h after the SAH induced by endovascular perforation. Chelerythrine or calyculin A was given immediately via intracerebroventricular administration after SAH. The SAH grade, Garcia score, and brain water content were measured at 24 and 72 h after the SAH. Neuronal apoptosis was detected by an immunofluorescent assay. The expression levels of endogenous PCMT1, MST1, phospho-MST1 (p-MST1), cleaved MST1 (cl-MST1), and apoptosis-related proteins were studied by western blotting. The expression of PCMT1 and MST1 decreased, while the level of active caspase 3 increased in rats after SAH. CGP 3466B treatment improved neurobehavioral function, reduced brain water content, inhibited the activity of MST1, and relieved neuronal apoptosis. These neuroprotective effects were significantly weakened either through accelerating MST1 phosphorylation by calyculin A or increasing cl-MST1 by chelerythrine. PCMT1 inhibited neuronal apoptosis by reducing MST1 phosphorylation and the level of cl-MST1. PCMT1/MST1 pathway might be an alternative therapeutic target for alleviating early brain injury after SAH.