Should we studying vD as a putative neurorestorative agent? #MSBlog #MSResearch #ClinicSpeak
"The study below suggests that vD has positive effects on neural stem cells (NSCs) and therefore may have a role to play in recovery from MS relapses. vD increases the proliferation of NSCs that then differentiate into neurons and oligodendrocytes that make myelin. Could this be relevant to recovery from relapses in MS? Could MSers who are vD sufficient, or replete, more likely to recover from relapses? This can be studied in vivo (within the body); there are some MRI techniques that can be used to measure remyelination in focal MS lesions. The problem with this however is low vD levels have been linked to inflammation; one could argue that the low vD levels results in more severe focal inflammation and hence more damage. It will be difficult to tease out the disparate effects of vD biology, therefore it may be better to study vD's putative effect on remyelination in a 'non-inflammatory' demyelinating animal model; we have the ability to make animals vD deficient by feeding them on a special diet."
"Please don't forget reverse causation; i.e inflammation causes the low vD levels and not the other way round. Almost all inflammatory diseases are associated with low vD levels. Most epidemiologists I speak to don't buy that low vD levels drive inflammation in MS. They say the association is too weak and too non-specific. Please note this statement refers to MS disease activity in established MS and not to vD as a putative preventive strategy. Most epidemiologists acknowledge the only way to sort this out is to do a large population-based vD supplementation study."
"We recommend all our patients with MS take vD supplements with the aim of making them vD replete. The rationale for the this is not because there is evidence that vD is disease modifying, but for bone health. We know that MSers are more likely to be have thin bones (osteopaenia and/or osteoporosis) and are high risk of falls and fractures. vD supplements have been shown to have a positive impact on bone health, albeit in elderly females. What really needs to be done is a national study on vD supplements in MSers to see if it has a positive impact on bone health. It is not ideal to translate data, or evidence, generated in one population to another population."
Epub: Shirazi et al. 1,25-dihydroxyvitamin D3 enhances neural stem cell proliferation and oligodendrocyte differentiation. Exp Mol Pathol. 2015 Feb 10. pii: S0014-4800(15)00023-4. doi: 10.1016/j.yexmp.2015.02.004.
Background: 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) has recently been found to suppress experimental autoimmune encephalomyelitis (EAE), an animal model of MS.Although its effect was attributed to an anti-inflammatory mechanism, it is not clear whether this treatment can also directly act on neural cells to promote CNS recovery.
Objective: The present study investigates the effect of various concentrations of 1,25(OH)2D3 on neural stem cell (NSC) proliferation and their differentiation to oligodendrocytes, the myelinating cells.
Results: We have, for the first time, shown that NSCs constitutively express vitamin D receptor (VDR), which can be upregulated by 1,25(OH)2D3. This vitamin significantly enhanced proliferation of NSCs, and enhanced their differentiation into neurons and oligodendrocytes, but not astrocytes. NSCs treated with 1,25(OH)2D3 showed increased expression of NT-3, BDNF, GDNF and CNTF, important neurotrophic factors for neural cell survival and differentiation.
Conclusions: Overall, we demonstrated that 1,25(OH)2D3 has a direct effect on NSC proliferation, survival, and neuron/oligodendrocyte differentiation, thus representing a novel mechanism underlying its remyelinating and neuroprotective effect in MS/EAE therapy