Effect of Vitamin B Complex Treatment on Macrophages to Schwann Cells Association during Neuroinflammation after Peripheral Nerve Injury

Abstract

Peripheral nerve injury (PNI) triggers a complex multi-cellular response involving the injured neurons, Schwann cells (SCs), and immune cells, often resulting in poor functional recovery. The aim of this study was to investigate the effects of the treatment with vitamin B (B1, B2, B3, B5, B6, and B12) complex on the interaction between macrophages and SCs during the recovery period after PNI. Transection of the motor branch of the femoral nerve followed by reconstruction by termino-terminal anastomosis was used as an experimental model. Isolated nerves from the sham (S), operated (O), and operated groups treated with the B vitamins (OT group) were used for immunofluorescence analysis. The obtained data indicated that PNI modulates interactions between macrophages and SCs in a time-dependent manner. The treatment with B vitamins complex promoted the M1-to M2-macrophage polarization and accelerated the transition from the non-myelin to myelin-forming SCs, an indicative of SCs maturation. The effect of B vitamins complex on both cell types was accompanied with an increase in macrophage/SC interactions, all of which correlated with the regeneration of the injured nerve. Clearly, the capacity of B vitamins to modulate macrophages-SCs interaction may be promising for the treatment of PNI.

Vitamin B Complex and Experimental Autoimmune Encephalomyelitis –Attenuation of the Clinical Signs and Gut Microbiota Dysbiosis

“…On the contrary, our findings displayed that VBC treatment contributed to the increased nerve nuclear density at the end of the disease. These observations could be correlated with our recently published results showing that VBC caused a time-dependent rise of cell number ( i.e., macrophages/Schwann cells) and their mutual interactions that are most likely associated with the regeneration of the injured nerve [ 26 , 27 ]. In addition to Schwann cells, one study outlined the significance of the olfactory nerve glia, which is more efficient in removing myelin debris and promoting neuronal regeneration than Schwann cells.…”

“…In our previously published paper [ 25 ], we have shown that VBC (a complex of vitamins B1, B2, B3, B5, B6, and B12) treatment enhanced the motor nerve regeneration and the recovery of muscle function in a rat model of peripheral nerve injury. Briefly, VBC therapy improved axonal regeneration, as well as functional recovery, by reducing both Schwann cell decline and deterioration of myelin sheath [ 26 ]. Moreover, we have demonstrated that treatment with VBC complex accelerated this recovery via attenuation of neuroinflammation [ 27 ].…”

The Role of Dietary Nutrients in Peripheral Nerve Regeneration

“…A study by Ehmedah et al demonstrated a modulatory effect on the macrophage-SC interaction during the early stages of Wallerian degeneration after nerve injury. Treatment with the B vitamin complex accelerated the transition from the non-myelin to myelin-forming SCs, which was accompanied by an increase in macrophage-SC interactions toward accelerating the transition from indispensable inflammation to nerve repair processes after peripheral nerve injury [130]. In the following, we report available knowledge on the different members of the vitamin B complex, always mainly focusing on peripheral nervous system studies.…”

The Role of Methyl Donors of the Methionine Cycle in Gastrointestinal Infection and Inflammation

“…In mice with methionine-high and B6, folate, and B12-low diets, microhemorrhages and amyloid-plaque buildup was observed in neural tissue, corresponding with increased inflammatory cytokine expression, emphasizing the protective effect of methyl donors and the dangerous impact of homocysteine [ 138 , 139 ]. B complex supplementation was shown to have a beneficial effect on peripheral nerve repair; B vitamin injections reduced inflammatory cytokine expression, polarized macrophages towards an M2 phenotype, and induced an anti-inflammatory phenotype in Schwann cells following injury [ 140 ]. The fact that B12 is implicated in neuroprotection in both the central and peripheral aspects of the nervous system suggests that neural tissue has a particular dependence on vitamin B12 that is still being elucidated, with a specific interest in a putative role for injury prevention and repair.…”