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Histone Deacetylase 3 Supports Cystathionine β‐synthase Mediated Bone formation by Controlling Cytokine Signaling and Matrix Remodeling
Author(s) -
Behera Jyotirmaya,
Zhai Yuankun,
Bala Jyoti,
Tyagi Suresh C,
Tyagi Neetu
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.1033.3
Subject(s) - osteoblast , chemistry , osteoclast , endocrinology , bone remodeling , bone resorption , medicine , microbiology and biotechnology , biology , biochemistry , in vitro
Cystathionine beta‐synthase (CBS) is a crucial enzyme in homocysteine (Hcy) metabolism. CBS deficiency cause hyperhomocysteinemia (HHcy) which confers diverse clinical manifestations, notably characteristic skeletal abnormalities. However, several clinical trials demonstrated that despite reduction in Hcy levels, bone disease outcome remained unaffected, thus the mechanism of bone formation is poorly defined. Therefore, we hypothesize that CBS as a novel molecular regulator in osteoblasts which promotes bone development. To test this hypothesis, we used 8–12 weeks old mice in our study; wild type mice (C57BL/6, WT) and CBS+/− mice. Silencing CBS function in osteoblast by either inhibitor hydroxylamine (HA) or CRISPR/CAS‐9 mediated gene knockout in vitro and bone marrow derived CBS‐deficient ( CBS+/− ) osteoblast causes reduced osteoblast differentiation and mineralization and increased osteoclast activity. Bone marrow derived CBS‐deficient ( CBS+/− ) osteoblasts exhibited exaggerated oxidative stress mechanism and further increased the expression of inflammatory cytokine and matrix‐degrading genes (IL‐6, MMP‐9, MMP‐13) and reduced expression of genes related to extracellular matrix production, bone development (ALP, Col1A, RUNX2, OSTERIX, OCN, OPN). ELISA assay identified among others IL‐6 to be present in plasma of CBS(+/−) mice but not in plasma of wild type mice (C57BL/6, WT ). Furthermore, histone deacetylase activity 3 also decreased under oxidative stress mechanism via phosphorylation dependent manner. This leads to activation and acetylation of nuclear factor Kb (NF‐kB). This increased inflammatory cytokine production further suppresses the osteoblast differentiation and paracrine activation of osteoclasts and bone resorption via IL‐6 signaling. This increased resorptive activity is further confirmed with immunostaining of tibia cross section by TRAP‐activity and increased osteoclasts number in bone tissue of CBS+/− mice. Blockade of HDAC3 activation in CBS‐deficient ( CBS+/− ) osteoblast by RGFP566 (HDAC3 Inhibitor) leads to the remodelling of histone landscapes in genome and thereby accelerates histone acetylation via recognising the acetylated lysine residue in histone (H3K27ac) of chromatin. This eventually resulted in transcriptional activation of MMP9,‐13 and IL‐6 gene expression. Thus, CBS controls the temporal and spatial expression of tissue‐remodeling genes and inflammatory responses in osteoblast to ensure proper bone development. In conclusion, we demonstrate that CBS control the osteoblasts balances, osteoblast differentiation/mineralization and osteoclastgenesis via HDAC3 dependent manner during bone development. Support or Funding Information This work is financial supported from National Institute of health grant AR‐067667 and HL‐107640‐NT are greatly acknowledged.