Osteoblast differentiation of NIH3T3 fibroblasts is associated with changes in the IGF-I/IGFBP expression pattern

Development of triamcinolone acetonide-hyaluronic acid conjugates with selective targeting and less osteoporosis effect for rheumatoid arthritis treatments

Rheumatoid arthritis (RA) is a common systemic autoimmune disease in developed countries. In clinical treatment, steroids have been used as bridging and adjunctive therapy after disease-modifying anti-rheumatic drug administration. However, the severe side effects caused by the nonspecific targeting of organs followed by long-term administration have limited their usage in RA. In this study, poorly water-soluble triamcinolone acetonide (TA), a highly potent corticosteroid for intra-articular injection, is conjugated on hyaluronic acid (HA) for intravenous purposes with increased specific drug accumulation in inflamed parts for RA. Our results demonstrate that the designed HA/TA coupling reaction reveals >98 % conjugation efficiency in the dimethyl sulfoxide/water system, and the resulting HA-TA conjugates show lower osteoblastic apoptosis compared with that in free TA-treated osteoblast-like NIH3T3 cells. Furthermore, in a collagen-antibody-induced arthritis animal study, HA-TA conjugates enhanced the initiative targeting ability to inflame tissue and reduce the histopathological arthritic changes (score = 0). Additionally, the level of bone formation marker P1NP in HA-TA-treated ovariectomized mice (303.6 ± 40.6 pg/mL) is significantly higher than that in the free TA-treated group (143.1 ± 3.9 pg/mL), indicating the potential for osteoporotic reduction using an efficient HA conjugation strategy for the long-term administration of steroids against RA.

The role of the insulin‑like growth factor (IGF) axis in osteogenic and odontogenic differentiation

The insulin-like growth factor (IGF) axis is a multicomponent molecular network which has important biological functions in the development and maintenance of differentiated tissue function(s). One of the most important functions of the IGF axis is the control of skeletal tissue metabolism by the finely tuned regulation of the process of osteogenesis. To achieve this, the IGF axis controls the activity of several cell types—osteoprogenitor cells, osteoblasts, osteocytes and osteoclasts to achieve the co-ordinated development of appropriate hard tissue structure and associated matrix deposition. In addition, there is an increasing awareness that the IGF axis also plays a role in the process of odontogenesis (tooth formation). In this review, we highlight some of the key findings in both of these areas. A further understanding of the role of the IGF axis in hard tissue biology may contribute to tissue regeneration strategies in cases of skeletal tissue trauma.

MiR-143 is not essential for adipose development as revealed by in vivo antisense targeting

MiR-143 plays an important role in promoting the adipogenic differentiation of pre-adipocytes. Here, we report that systematic silencing of miR-143 in mice by using a locked-nucleic-acid-modified oligonucleotide (LNA-antimiR) did not lead to any obvious abnormalities in the adipose tissue differentiation. Furthermore, there were no significant differences in the expression level of several adipogenic marker genes, such as PPARγ and C/EBPα, in these animals compared with the controls. Therefore, we hypothesize that miR-143 may function as a fine tuning molecule rather than as a switch in the adipogenic regulatory network in mice. In addition, the proposed miR-143 target, ERK5, which was previously identified in human preadipocytes, was not effectively inhibited by miR-143 either in the murine preadipocyte cell line, 3T3-L1, or in primary mouse adipose tissue. However, we did fibroblast growth factor 7 (Fgf7) was identified as a target of miR-143 in murine adipogenesis.

Basal expression of pluripotency-associated genes can contribute to stemness property and differentiation potential

Pluripotency and stemness is believed to be associated with high Oct-3/4, Nanog, and Sox-2 (ONS) expression. Similar to embryonic stem cells (ESCs), high ONS expression eventually became the measure of pluripotency in any cell. The threshold expression of ONS genes that underscores pluripotency, stemness, and differentiation potential is still unclear. Therefore, we raised a question as to whether pluripotency and stemness is a function of basal ONS gene expression. To prove this, we carried out a comparative study between basal ONS expressing NIH3T3 cells with pluripotent mouse bone marrow mesenchymal stem cells (mBMSC) and mouse ESC. Our studies on cellular, molecular, and immunological biomarkers between NIH3T3 and mBMSC demonstrated stemness property of undifferentiated NIH3T3 cells that was similar to mBMSC and somewhat close to ESC as well. In vivo teratoma formation with all three germ layer derivatives strengthen the fact that these cells in spite of basal ONS gene expression can differentiate into cells of multiple lineages without any genetic modification. Conclusively, our novel findings suggested that the phenomenon of pluripotency which imparts ability for multilineage cell differentiation is not necessarily a function of high ONS gene expression.

Effects of Panax notoginseng saponins on proliferation and differentiation in NIH3T3 cells

OBJECTIVE

To investigate the effects of Panax notoginseng saponins (PNS) on the proliferation and differentiation in NIH3T3 cells.

METHODS

NIH3T3 cells were treated by various concentrations of PNS 0, 0.05, 0.10, 0.20, and 0.40 g/L. The vitality and proliferation potential of cells were detected by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, the alkaline phosphatase (ALP) activity was measured by p-nitrophenyl phosphate (pNPP) assay, and the mineralization formation ability was tested for the cellular differentiation toward osteoblast, as well as the expression level of phosphorylated extracellular signal-regulated kinase1/2(P-ERK1/2), extracellular signal-regulated kinase1/2 (ERK1/2) protein kinase was analyzed by Western blot with total cell lysate of NIH3T3 cells treated by PNS.

RESULTS

Both MTT and pNPP assay showed that optical density (OD) values were increased in response to PNS treatment at a dose-dependent pattern. The mineralization formation ability was enhanced in PNS-treated NIH3T3 cells compared with untreated cells. Meanwhile, the expression level of P-ERK1/2 protein kinase was up-regulated in PNS-treated NIH3T3 cells, while, the expression level of ERK1/2 protein kinase revealed no obvious difference with or without PNS treated cells.

CONCLUSION

PNS could pay a role to promote the proliferation and differentiation in NIH3T3 cells by means of up-regulation of P-ERK1/2 protein kinase.

Glypican-3-mediated oncogenesis involves the Insulin-like growth factor-signaling pathway

Glypican-3 (gpc3) is the gene responsible for Simpson-Golabi-Behmel overgrowth syndrome. Previously, we have shown that GPC3 is overexpressed in hepatocellular carcinoma (HCC). In this study, we demonstrated the mechanisms for GPC3-mediated oncogenesis. Firstly, GPC3 overexpression in NIH3T3 cells gave to cancer cell phenotypes including growing in serum-free medium and forming colonies in soft agar, or on the other way, GPC3 knockdown in HuH-7 cells decreased oncogenecity. We further demonstrated that GPC3 bound specifically through its N-terminal proline-rich region to both Insulin-like growth factor (IGF)-II and IGF-1R. GPC3 stimulated the phosphorylation of IGF-1R and the downstream signaling molecule extracellular signal-regulated kinase (ERK) in an IGF-II-dependent way. Also, GPC3 knockdown in HCC cells decreased the phosphorylation of both IGF-1R and ERK. Therefore, GPC3 confers oncogenecity through the interaction between IGF-II and its receptor, and the subsequent activation of the IGF-signaling pathway. This data are novel to the current understanding of the role of GPC3 in HCC and will be important in future developments of cancer therapy.