Treatment with hydrogen molecules prevents RANKL-induced osteoclast differentiation associated with inhibition of ROS formation and inactivation of MAPK, AKT and NF-kappa B pathways in murine RAW264.7 cells

Abstract

The bone protective effects of the hydrogen molecule (H2) have been demonstrated in several osteoporosis models while the underlying molecular mechanism has remained unclear. Osteoclast differentiation is an important factor related to the pathogenesis of bone-loss related diseases. In this work, we evaluated the effects of incubation with H2 on receptor activator of NFκB ligand (RANKL)-induced osteoclast differentiation. We found that treatment with H2 prevented RANKL-induced osteoclast differentiation in RAW264.7 cells and BMMs. Treatment with H2 inhibits the ability to form resorption pits of BMMs stimulated by RANKL. Treatment with H2 reduced mRNA levels of osteoclast-specific markers including tartrate resistant acid phosphatase, calcitonin receptor, cathepsin K, metalloproteinase-9, carbonic anhydrase typeII, and vacuolar-type H(+)-ATPase. Treatment with H2 decreased intracellular reactive oxygen species (ROS) formation, suppressed NADPH oxidase activity, down-regulated Rac1 activity and Nox1 expression, reduced mitochondrial ROS formation, and enhanced nuclear factor E2-related factor 2 nuclear translocation and heme oxygenase-1 activity. In addition, treatment with H2 suppressed RANKL-induced expression of nuclear factor of activated T cells c1 and c-Fos. Furthermore, treatment with H2 suppressed NF-κB activation and reduced phosphorylation of p38, extracellular signal-regulated kinase, c-Jun-N-terminal kinase, and protein kinases B (AKT) stimulated with RANKL. In conclusion, hydrogen molecules prevented RANKL-induced osteoclast differentiation associated with inhibition of reactive oxygen species formation and inactivation of NF-κB, mitogen-activated protein kinase and AKT pathways.

Protective effects of resveratrol on postmenopausal osteoporosis: regulation of SIRT1-NF-κB signaling pathway

“…Previous studies reported that NF-kB was associated with osteoporosis as for its predominant role in osteoclastogenesis [31][32][33]. Here, our results demonstrated that NF-kB acts as a negative regulator in osteoblast differentiation, which also regulated the process of osteoporosis.…”

Osseointegration of chitosan coated porous titanium alloy implant by reactive oxygen species-mediated activation of the PI3K/AKT pathway under diabetic conditions

“…On the other hand, AKT, the serineethreonine kinase, can function to either reduce or prevent cellular destruction from oxidants [45]. Extrinsic ROS overproduction inactivated AKT and related mTOR signals, increased apoptotic factor Bad activity and inhibiting anti-apoptotic factor BcL-2 [11,46]. In the present study, DM-mediated ROS overproduction significantly suppressed AKT phosphorylation, further lead to impaired osteoblast adhesion and morphology, decreased cell proliferation and ALP activity, and increased cytotoxicity and apoptotic injury, which were in accordance with some previous reports [17,18].…”

TRAP-positive osteoclast precursors mediate ROS/NO-dependent bactericidal activity via TLR4

“…Furthermore, lines of evince support ROS and NO as cell signaling molecules in innate immune cells [35,36]. Interestingly, ROS produced by osteoclasts play a role in promoting the differentiation of these cells through Akt, NF-κB and ERK activation [37,38], suggesting that ROS function as a cell signaling mediator in osteoclastogenesis. Recent study reported that ROS-induced promotion of osteoclastogenesis is downmodulated by an antioxidant response system involving Nerf2 in the homeostatic context [39,40], indicating the presence of a sophisticated regulatory mechanism for ROS-associated osteoclastogenesis.…”