25(OH)D3, 25-hydroxycholecalciferol, the major circulating vitamin D metabolite

ACC, acetyl-CoA carboxylase

ADCP, antibody dependent cellular phagocytosis

AD, alzheimer’s disease

AKT, AKT serine/threonine kinase 1, essential effector of PI3K, promotes myelination in the CNS via the mTOR pathway

AChE, acetylcholinesterase

AMPK, adenosine monophosphate-activated protein kinase pathway

APJ, apelin receptor

ApoE, apolipoprotein E

APC, antigen-presenting cell

ATP, adenosine triphosphate, molecule that stores and transfers energy

BAFF, B-cell activating factor

BBB, blood-brain barrier

BChE, butirylcholinesterase

BCR, B-cell receptor

BDNF, brain-derived neurotrophic factor

BMP, bone morphogenetic protein

Ca2+, calcium ions

cAMP, intracellular cyclic adenosine monophosphate

CCL, C-C motif chemokine ligand

CCR, C-C chemokine receptor

CD, cluster of differentiation

CerDase, ceramidase

CerS, ceramide synthase

CNP, 2,3-cyclic nucleotide 3-phosphodiesterase

CNTF, ciliary neurotrophic factor

CGT, UDP–galactose:ceramide galactosyltransferase

CNS, central nervous system

COX-2, cyclooxygenase-2

CREB, cyclic AMP-responsive element-binding protein

CSF, cerebrospinal fluid

CSPGs, chondroitin sulfate proteoglycans

CXCL, C-X-C motif chemokine ligand

CXCR, C-X-C motif chemokine receptor

CXCL1, CXCL8, CXCL10, CXCL12 chemokine ligand 1, 8, 10, and 12

DCs, dendritic cells

DCLN, deep cervical lymph node

DDIT4, DNA damage inducible transcript 4, aka REDD1/Dig2/RTP801, is a negative regulator of myelination

DHODH, dihydroorotate dehydrogenase

DMF, dimethyl fumarate

DMTs, disease-modifying therapies

DNA, deoxyribonucleic acid;

EAE, experimental autoimmune encephalomyelitis

EBER1, EBV-encoded small RNAs 1, 2

EBNA, EBV nuclear antigen 1, 2, 3A, 3B, 3C

EBP, emopamil-binding protein

EBV, Epstein-Barr virus

EC, endothelial cell

EDSS, expanded disability status scale

Eomes, eomesodermin, aka T-box brain 2

ER, endoplasmic reticulum

ERK, extracellular signal-regulated kinases

EV, extracellular vesicle

ET-1, endothelin-1

FA, fatty acid

FASN, fatty acid synthase

Fe2+, ferrous iron

Fe3+, ferric iron

FGF, fibroblast growth factor

FoxP3, Forkhead box P3

Gal-1, galectin-1

GalC, galactosylceramidase

GalCer, galactosylceramide

Gas6, growth arrest specific gene 6, a vitamin K-dependent gene

GC, germinal center

GFAP, Glial Fibrillary Acidic Protein (marker of astrocytes)

GFPT, glutamine-fructose-6-phosphate transaminase

GlcCer, glucosylceramide

GlcNAc, N-acetylglucosamine

GLUT1, glucose transporter 1

GSH, glutathione

GPx, glutathione peroxidase

GT, glycosyltransferase

H2O2, Hydrogen peroxide

HBP, hexosamine biosynthetic pathway

HCQ, Hydroxychloroquine

HDAC1, histone deacetylase 1

HDL, high-density lipoprotein

HGF, hepatocyte growth factor

HHV-6, human herpesvirus type-6

HLA, human leukocyte antigen

HMW, high molecular weight

HPV,  human papilloma virus;

HSV, herpes simplex virus;

HSPs, heat-shock proteins

HSV, herpes simplex virus;

ICAM-1, Intercellular adhesion molecule-1

IDP, intrinsically disordered protein

IDR, intrinsically disordered region

IGF-1, insulin-like growth factor-1

IFNAR, interferon α/β receptor.

IFN-γ, Interferon-gamma

IL, interleukin

IL-1β, interleukin-1β

IL-4, interleukin 4

IL2Ra, interleukin 2 receptor α

IL7Ra, interleukin 7 receptor α

IM, infectious mononucleosis

iNOS, inducible nitric oxide synthase

IRL, iron rimmed lesion

IU, international unit

JAM2, junction adhesion molecule 2

JCV, John Cunningham virus

JNK, jun N-terminal kinase

K+, potassium ions

LFA-1, leukocyte function associated antigen-1

LIF, leukemia inhibitory factor

LINGO-1, leucine-rich repeat and Ig-like domain-containing Nogo receptor interacting protein 1, a transmembrane protein, is expressed explicitly in OLs and neurons, a potent negative modulator of axonal myelination and regeneration in the CNS.

LMW, low molecular weight

LMP, latent membrane protein 1, 2

LN, lymph node

LPC, lysophosphatidylcholine

LXR , liver X receptor

mAb, monoclonal antibodies

MAG, myelin-associated glycoprotein

MAPK, mitogen-activated protein kinase

MBP, myelin basic protein

MBC, memory B cell

M-CSF, macrophage colony stimulating factor

MCT, monocarboxylate transporter

MEK1, MAPK kinase 1, upstream activator of ERK1/2

MGAT1, N-acetylglucosaminyltransferase 1 

MMPs, matrix metalloproteinases

MOG, myelin oligodendrocyte glycoprotein

mRNA, messenger ribonucleic acid

MS, Multiple Sclerosis

MSFC, MS functional composite

MRI, magnetic resonance imaging

mtDNA, mitochondrial DNA

mTOR, mammalian target of rapamycin, downstream of the PI3K-AKT signaling pathway, core element of two complexes, mTORC1 and mTORC2, with different functions in the complex.

MUFAs, mono unsaturated fatty acids

MYRF, myelin regulatory factor, a membrane-bound transcriptional factor on the endoplasmic reticulum (ER)

Na+, sodium ions 

Na+K+ATPase, sodium-potassium pump

NAC, n-acetyl cysteine

NAG, n-acetyl glucosamine

NAD, nicotinamide adenine dinucleotide

NADP, nicotinamide adenine dinucleotide phosphate

NADPH, reduced form of nicotinamide adenine dinucleotide phosphate

NCX, Na+/Ca2+ exchanger

NfL, neurofilament light chain

NG2, proteoglycan neuron-glial antigen 2

NG2, chondroitin sulfate proteoglycan neuron-glia antigen 2, a factor maintaining OPC proliferation and preventing OL differentiation.

NKCs, natural killer cells

Nkx2.2, NK2 homeobox 2

NMO, neuromyelitis optica

NMOSDs, neuromyelitis optica spectrum disorders

NO, nitric oxide

NSCs, neural stem cells

NOTCH1, notch receptor

NPC, neural precursor cell 

NR, nodes of Ranvier

Nrf2, nuclear factor erythroid-2-related factor-2 pathway

NRG1, neuregulin-1, promotes OPC migration, proliferation, and differentiation into OLs

NRG1/ErbB, Erb-b2 receptor tyrosine kinase, signaling is required for OL survival and maturation.

Nurr1, Nuclear Receptor-Related 1

OL, oligodendrocyte

OLIG2, oligodendrocyte transcription factor 2, a primary helix-loop-helix transcription factor

OPC, oligodendrocyte precursor cell

PI3K, phosphatidylinositol-4,5-bisphosphate 3-kinase

p75NTR, p75 neurotrophin receptor, a BDNF transmembrane receptor

PAD2, peptidyl-arginine deiminase 2

parkin, an E3 ubiquitin ligase

PBMC, peripheral blood mononuclear cell

PD, parkinson’s disease

PDEs, phosphodiesterases, implicated in OL maturation and myelination in the CNS

PDGF, platelet derived growth factor

PDGF-AA, platelet-derived growth factor AA

PDGFR-β, platelet-derived growth-factor receptor β

PKD1, protein kinase D1)

PLP, proteolipid protein

PML, progressive multifocal leukoencephalopathy

PPAR, peroxisome proliferator-activated receptor

PRES, posterior reversible encephalopathy syndrome

PTM, post-translational modification 
PTEN, phosphatase and tensin homolog, inhibits the PI3K-Akt-mTOR signaling pathway, negatively regulating myelination

PUFAs, poly unsaturated fatty acids

RA, rheumatoid arthritis

RA, retinoic acid

RA, rosmarinic acid

RAPTOR, regulatory-associated protein of MTOR complex 1

RASGRP2, RAS guanyl-releasing protein 2

RHEB, Ras homolog, mTORC1 binding

RhoA, Ras homolog family membeor A

RICTOR, RAPTOR independent companion of MTOR complex 2

RIPK-1, receptor-interacting protein kinase 1

RORγ, retinoid-related orphan receptor gamma

RRMS, relapsing–remitting MS

RXR, retinoid X receptor

RXR-γ, retinoid x receptor gamma

S1P, sphingosine-1-phosphate

S1PR, sphingosine 1-phosphate receptor

SFAs, saturated fatty acids

SCFAs, short chain fatty acids

sGalC, galactosulfatide 

SGZ, sub granular zone of the hippocampus

SHH, sonic hedgehog, a critical factor for OL lineage specification

Smo and Gli1 are the essential components of the SHH signaling pathway

SHM, somatic hypermutation

SK1/2, sphingosine kinase 1/2

SLE, systemic lupus erythematosus

SMase, sphingomyelinase

Smo, smoothened, frizzled class receptor

SMS, sphingomyelin synthase

sNFL, serum neurofilament light chain protein

SNPs, single-nucleotide polymorphisms

SOX2, SRY (sex-determining region Y)-box transcription factor 2

Sphk, sphingosine kinase

SPMS, secondary progressive MS

SPNS2, SPNS lysolipid transporter 2

SPT, serine palmitoyl transferase

SVZ, sub ventricular zone of the lateral ventricles

SVZ-OPCs, SVZ-derived oligodendrocyte progenitor cells

Tbet, T-box expressed in T cells

TCN2, transcobalamin

TCR, T-cell receptor

TG2, transglutaminase-2

TGF-b, transforming growth factor- beta

TGF-β1, transforming growth factor-β1

Th, T helper

Th1, type 1 T helper cell

Th2, type 2 T helper cell

TIMPs, tissue inhibitors of metalloproteinases

TIMP-1, tissue inhibitor of metalloproteinases-1

TMEM98, transmembrane protein 98, can block MYRF self-cleavage

TNF-α, tumor necrosis factor-alpha

TRAF3, TNF receptor-associated factor adaptor protein 3

Treg, regulatory T-cell

TREM2, triggering receptor expressed on myeloid cells 2

TRKB, tropomyosin-related kinase receptor B, a BDNF transmembrane receptor

Trm, Tissue-resident memory T cells

TSC1, tuberous sclerosis protein 1, with TSC2 they negatively regulate mTORC1 signaling

TTR, Transthyretin, binds and transfers thyroid hormones in CSF and blood

UDP-GlcNAc, Uridine Diphosphate N-acetylglucosamine

UGCG, UDP-glucose ceramide glycosyltransferase

UV, ultraviolet

VDR, vitamin D Receptor

VEGF, vascular endothelial growth factor

VLA, very late antigen

WNT, wingless-type MMTV integration site family

Wnt-β-Catenin-TCF-LEF cascade, canonical Wnt-β-Catenin signaling pathway