Interferon-beta modulates bone-associated cytokines and osteoclast precursor activity in multiple sclerosis patients.
OBJECTIVE
Multiple sclerosis (MS) patients have a high risk of low bone density. The purpose of this study was to examine the molecular mechanisms potentially capable of modulating bone homeostasis in response to interferon-beta-1a (IFN-beta-1a) treatment and the focus was the bone-modulating system comprised of receptor activator of nuclear factor-kappaB (RANK), its ligand RANKL and its decoy receptor, osteoprotegerin (OPG).


METHODS
In this open-label pharmacodynamic study, peripheral blood was obtained from relapsing-remitting MS patients just prior to and at multiple time points after intramuscular injection of 30 microg IFN-beta-1a. Samples were analysed for RANKL, tumour necrosis factor related apoptosis-inducing ligand (TRAIL), OPG and macrophage inflammatory protein-1 alpha/beta expression. Osteoclast precursor differentiation from peripheral blood cells of MS patients in the presence of exogenously added IFN-beta-1a was also assessed. Additionally, the changes in plasma levels of osteocalcin and the C-telopeptides after 1 year of treatment were measured as surrogate markers of bone formation and degradation, respectively.


RESULTS
IFN-beta-1a treatment modulated RANKL and OPG in a selective, time-dependent manner. The levels of OPG protein decreased 25% at the 8-h time point, then increased 43% at the 24-h time point. The levels of free RANKL reached a maximum at the 8-h time point. Increases in the levels of macrophage inflammatory protein-1beta (MIP-1beta), a chemokine that increases osteolysis, were observed. The levels of the bone formation marker, osteocalcin, were lower in MS patients compared to controls and increased after one year of treatment. Ex vivo treatment of peripheral blood lymphocytes with IFN-beta resulted in a marked reduction of osteoclast-like cells in the presence of RANKL and macrophage colony stimulating factor.


CONCLUSIONS
IFN-beta treatment induces complex, specific and time-dependent changes in multiple proteins and mRNAs related to bone homeostasis in MS patients.
Weinstock-Guttman
Bianca
B
Jacobs Neurological Institute, Buffalo General Hospital, Buffalo, NY 14203, USA.
Hong
Jianming
J
Santos
Roseane
R
Tamaño-Blanco
Miriam
M
Badgett
Darlene
D
Patrick
Kara
K
Baier
Monika
M
Feichter
Joan
J
Gallagher
Eileen
E
Garg
Neeta
N
Ramanathan
Murali
M
D000328:Adult; D024042:Collagen Type I / Q000096:biosynthesis; D016207:Cytokines / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D015870:Gene Expression / Q000187:drug effects*; D006801:Humans; D007155:Immunologic Factors / Q000494:pharmacology* / Q000627:therapeutic use; D016899:Interferon-beta / Q000494:pharmacology* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000188:drug therapy / Q000378:metabolism*; D015675:Osteocalcin / Q000097:blood; D053244:Osteoprotegerin / Q000378:metabolism*; D010455:Peptides; D053245:RANK Ligand / Q000097:blood; D012333:RNA, Messenger; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D018709:Statistics, Nonparametric; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000097:blood; D013997:Time Factors
D024042:Collagen Type I; D016207:Cytokines; D007155:Immunologic Factors; D053244:Osteoprotegerin; D010455:Peptides; D053245:RANK Ligand; D012333:RNA, Messenger; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; C052929:collagen type I trimeric cross-linked peptide; D015675:Osteocalcin; D016899:Interferon-beta