The molecular pathways leading to disease severity progression and remyelination failure or success in MS remain largely unknown (20). While the molecular mechanisms of melanogenesis and myelin gene activation and inactivation are not completely clarified, finding a potential way to activating of melanogenesis in MS patients, could lead to a potential treatment for neural loss of functions in CNS.
Our early results showed, that several markers of myelination (21) are down-regulated in the spinal cord during EAE and significantly raised after the force-feeding of opium tincture. Some of these genes are related to each other in several signaling pathways and contribute to neuronal plasticity. Interestingly, our results on the up-regulation of meylinogenesis markers weren't gender dependent which may lead to a potentially applicable treatment for both genders in MS.
Opium usage could enhance the antioxidant capacity and reduce the inflammation in the CNS which can reduce the extent of damage in cerebral ischemia (22). Opium contains about frothy alkaloids and more than seventy components including several sugars and organic acids (23). Some opioid-based analgesics such as morphine are associated with immunosuppressive effects on innate immunity, whilst having diverse effects on adaptive immunity (24). It seems that using the whole alkaloid content of opium in a special taper-up-off protocol may induce anti-inflammation effects which in turn could lead to the gradual reactivation of meylinogensis that has been reduced dramatically during the MS symptoms advancement. The mechanism and mode of action of the DST method at the molecular level are not completely clarified, but it seems that opium, with several alkaloids, can help regulate upstream mechanisms of gene expression and epigenetics, especially transcription factors.
Previous studies showed the myelination expression patterns alterations in the spinal cords of EAE mice models induced by estrogen (25). It has been suggested that signaling pathways that promote myelin formation and repair could enhance remyelination (20). To the best of our knowledge, the main reasons for remyelination failure in EAE models as well as human MS patients include calpain genes overexpression and activation of glycolipid-reactive iNKT cells and sphingoid-mediated inflammation. In addition, the treatments for MS patients are based on Cytokine-based immune intervention, antigen-based immunomodulation, and also recombinant monoclonal antibodies which induce remyelination.
Major attribution of EGF in myelin gene expression, myelin sheath compaction, and myelinogenesis had been reported in both peripheral and central nervous systems (26). Although the processes of molecular mechanisms underlying oligodendrocyte myelinogenesis are poorly defined the significant over-expression of OLIG genes is a reliable marker for meylinogenesis activation (27). Moreover, MYRF is required to initiate and maintain myelination, and upregulation of MYRF along with MBP, UGT8, PLP1, and PMP22 could orchestrate the remyelination in neurodegenerative disease which in turn may lead to the improvement of the circuit's functions in CNS (28). The neural circuit's normal functions need several types of neurons astrocytes and oligodendrocytes, at the appropriate periods and regions (29).
Our early results may lead to the development of a treatment strategy that induces myelination by altering the epigenetic pattern of related genes; which could apply to other severe neurodegenerative diseases with loss of the neuronal circuits such as Huntington’s disease (HD), Parkinson’s disease (PD), and Amyotrophic Lateral Sclerosis (ALS) as well as MS. Therefore, the DST method of taper up-off of opium could improve the speed and efficiency of signal propagation.
Limitations:
Multiple sclerosis (MS) is an inflammatory and demyelinating disease of the central nervous system (CNS) that results in variable severities of neurodegeneration. While the early results of the present study were interesting, the myelination is not universally applied in the central nervous system and may vary in the spinal cord versus the brain in EAE models. Further results especially the whole genome expression profiling of samples may clarify our knowledge about the effects of opium usage with the DST method on the EAE model.