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  • With respect to bone metabolism and ossification related gen

    2019-07-11

    With respect to ‘bone metabolism and ossification’-related genes, treatment of SaOS-2 osteoblast-like sn-Glycero-3-phosphocholine with MS-10 up-regulated IGFBP-4, TG2, and SOST. Up-regulation of IGFBP-4 in SaOS-2 cells inhibits DNA and protein synthesis induced by IGF-1 (Kudo et al., 1995, Kudo et al., 1996). In addition, TG2 is expressed in cartilage and bone, including teeth, which are mineralized tissues. The TG2 enzyme assembles substrates into polymeric forms to promote matrix stabilization, chondrocyte and osteoblast differentiation, and matrix mineralization. TG2 is involved in osteoblast differentiation and may play a role in initiating and regulating mineralization (Cavelier et al., 2018, Kaartinen et al., 2002; X. Yin, Chen, Liu, & Song, 2012). SOST also is a major regulator of osteogenesis; indeed, circulating SOST is a biomarker for bone health (Idolazzi et al., 2018, Lim et al., 2016). Conversely, GPR183 (EBI2), NNMT, and ADAMTS5 were down-regulated by MS-10 treatment of SaOS-2 osteoblast-like cells. These genes are characterized as sn-Glycero-3-phosphocholine osteoclast differentiation- and estrogen deficiency-induced osteoporosis-related genes (Nevius et al., 2015, Toti et al., 2013). Thus, MS-10 induces significant changes in expression of osteogenesis-related genes in osteoblasts. We also examined activation of important ossification-related markers. In agreement with the regulation of ossification-related genes, MS-10 increased the activity of ALP and decreased the activity of TRACP in SaOS-2 cells. In addition, expression of osteocalcin, a key hormone for ossification, was increased by MS-10. However, a clinical study to evaluate the effects of MS-10 on menopausal symptoms showed that taking MS-10 for 3 months decreased BSALP and osteocalcin levels in serum. These factors are involved in ossification and osteogenesis (Blumsohn et al., 1994). In serum, BSALP and osteocalcin are regulated by negative feedback after bone loss (Indumati & Patil, 2010). Up-regulation of BSALP and osteocalcin has been reported in serum of older women with menopausal symptoms and osteoporosis, and BMD is inversely correlated with these factors (Aguilar et al., 2017, Delmas et al., 1983, Garnero et al., 1996). In other words, decreases in ALP activity and osteocalcin levels may be indicative of improved bone health.
    Conclusions
    Declaration of interests
    Introduction Over the past 20 years, the functional autonomy of both the immune and central nervous systems has been successfully challenged. Although the ventromedial hypothalamus (VMH) is one of the centers of parasympathetic nervous system, to date, there has been little reported regarding the role of the hypothalamus in directly changing the expression of immune response genes [1]. According to Okamoto et al. [2], acute (30min) electrical stimulation of the VMH caused a remarkable decrease in the mitogenic response of splenic lymphocytes to Concanavalin A, which is a plant mitogen, and is known for its ability to stimulate mouse T-cell subsets in rats [3]. The authors emphasized that this immunosuppressive effect is mediated through the activation of the sympathetic nerves via the beta-adrenergic pathway. Moreover, Kaname et al. [4] reported that VMH electrical stimulation, which elicits threat behaviors, induced granulocytosis and lymphopenia, including CD4+ and CD8+ cells, the decrease in the surface expression of CD62L on CD4+ and CD8+ cells or granulocytes which were concomitant with elevations of plasma cortisol, epinephrine and norepinephrine levels in the peripheral blood in cats. Moreover, the results obtained indicate that chronic electrical stimulation of the VMH decreases cell-mediated immune response, represented by NK cell activity [5]. Recently, it has been reported that VMH lesions can directly change the expression of immune response gene families [1]. Also, we previously reviewed focuses on the relationships between the VMH and the expressions of immune response genes [1]. We previously reported that VMH lesions stimulated cell proliferation of rat pancreatic islet B and acinar cells primarily through a cholinergic receptor mechanism [6], and changed the expression of cell proliferation-related genes [7] and metabolism-related genes in rat pancreatic islets [8]. DNA microarray analysis is a powerful tool for detecting the characterization of the messenger RNA (mRNA) expression pattern of a large number of genes. In the present study, we used DNA microarray analysis to identify multiple immune response genes for which expression profiles showed significant modulation and to investigate the cellular mechanisms of gene regulation in the rat pancreatic islets alone at day 3 after VMH lesions, because it has been reported that cell proliferation in the pancreas increases and reaches a maximum at day 3 [6]. Real-time polymerase chain reaction (PCR) also confirmed a part of the results obtained by DNA microarray analysis.