Magic™ Anti-NFATC1 (Phospho S233) monoclonal antibody, clone FQS3487(O)

Osteolytic bone diseases, for example postmenopausal osteoporosis, arise from the imbalances between osteoclasts and osteoblasts in the bone remodeling process, whereby osteoclastic bone resorption greatly exceeds osteoblastic bone formation resulting in severe bone loss and deterioration in bone structure and microarchitecture. Therefore, the identification of agents that can inhibit osteoclast formation and/or function for the treatment of osteolytic bone disease has been the focus of bone and orthopedic research. Vindoline (Vin), an indole alkaloid extracted from the medicinal plant Catharanthus roseus, has been shown to possess extensive biological and pharmacological benefits, but its effects on bone metabolism remains to be documented. Our study demonstrated for the first time, that Vin could inhibit osteoclast differentiation from bone marrow macrophages (BMMs) precursor cells as well as mature osteoclastic bone resorption. We further determined that the underlying molecular mechanism of action of Vin is in part due to its inhibitory effect against the activation of MAPK including p38, JNK, and ERK and intracellular reactive oxygen species (ROS) production. This effect ultimately suppressed the induction of c-Fos and NFATc1, which consequently downregulated the expression of the genes required for osteoclast formation and bone resorption. Consistent with our in vitro findings, in vivo administration of Vin protected mice against ovariectomy (OVX)-induced bone loss and trabecular bone deterioration. These results provided promising evidence for the potential therapeutic application of Vin as a novel treatment option against osteolytic diseases.

Objective: In view of our previous observations on differential expression of LMCD1 (LIM and cysteine-rich domains 1) in human versus rodents, we asked the question whether LMCD1 plays a species-specific role in the development of vascular lesions. Approach and Results: A combination of genetic, molecular, cellular, and disease models were used to test species-specific role of LMCD1 in the pathogenesis of vascular lesions. Here, we report species-specific regulation of LMCD1 expression in mediating vascular smooth muscle cell proliferation and migration during vascular wall remodeling in humans versus mice. Thrombin induced LMCD1 expression in human aortic smooth muscle cells but not mouse aortic smooth muscle cells via activation of Par1 (protease-activated receptor 1)-G alpha q/11 (G alpha protein q/11)-PLC beta 3 (phospholipase C beta 3)-NFATc1 (nuclear factor of activated T cells 1) signaling. Furthermore, although LMCD1 mediates thrombin-induced proliferation and migration of both human aortic smooth muscle cells and mouse aortic smooth muscle cells via influencing E2F1 (E2F transcription factor 1)-mediated CDC6 (cell division cycle 6) expression and NFATc1-mediated IL (interleukin)-33 expression, respectively, in humans, it acts as an activator, and in mice, it acts as a repressor of these transcriptional factors. Interestingly, LMCD1 repressor activity was nullified by N-myristoyltransferase 2-mediated myristoylation in mouse. Besides, we found increased expression of LMCD1 in human stenotic arteries as compared to nonstenotic arteries. On the other hand, LMCD1 expression was decreased in neointimal lesions of mouse injured arteries as compared to noninjured arteries. Conclusions: Together, these observations reveal that LMCD1 acts as an activator and repressor of E2F1 and NFATc1 in humans and mice, respectively, in the induction of CDC6 and IL-33 expression during development of vascular lesions. Based on these findings, LMCD could be a potential target for drug development against restenosis and atherosclerosis in humans.