Three-Dimensional Co-Culture System of Human Osteoblasts and Osteoclast Precursors from Osteoporotic Patients as an Innovative Model to Study the Role of Nutrients: Focus on Vitamin K2

Abstract

Several natural compounds, such as vitamin K2, have been highlighted for their positive effects on bone metabolism. It has been proposed that skeletal disorders, such as osteoporosis, may benefit from vitamin K2-based therapies or its regular intake. However, further studies are needed to better clarify the effects of vitamin K2 in bone disorders. To this aim, we developed in vitro a three-dimensional (3D) cell culture system one step closer to the bone microenvironment based on co-culturing osteoblasts and osteoclasts precursors obtained from bone specimens and peripheral blood of the same osteoporotic patient, respectively. Such a 3-D co-culture system was more informative than the traditional 2-D cell cultures when responsiveness to vitamin K2 was analyzed, paving the way for data interpretation on single patients. Following this approach, the anabolic effects of vitamin K2 on the osteoblast counterpart were found to be correlated with bone turnover markers measured in osteoporotic patients’ sera. Overall, our data suggest that co-cultured osteoblasts and osteoclast precursors from the same osteoporotic patient may be suitable to generate an in vitro 3-D experimental model that potentially reflects the individual’s bone metabolism and may be useful to predict personal responsiveness to nutraceutical or drug molecules designed to positively affect bone health.

Stimulation of Metabolic Activity and Cell Differentiation in Osteoblastic and Human Mesenchymal Stem Cells by a Nanohydroxyapatite Paste Bone Graft Substitute

“…The Ca 2+ ion concentration of the PCM was determined to be 0.45 ± 0.04 mM compared to the 1.8 mM Ca 2+ of the culture media. The reduction in the free Ca 2+ concentration in PCM is likely to be attributable to solution-mediated surface reactions between the nHA and Ca 2+ ions in the culture medium, indicating the nHA paste was a calcium-deficient hydroxyapatite [61,63]. In addition, instability of nHA in the culture medium can induce the formation of nHA agglomerates [27], which could be pelleted during centrifugation of the PCM.…”

“…Real-time RT-PCR (qPCR) reactions were set up with 0.5 µL cDNA, TaqMan Master Mix (Applied Biosystems, Thermo Fisher Scientific, Paisley, UK). 3-Glyceraldehyde phosphate dehydrogenase (GAPDH, primer sequence 4326317E, Applied Biosystems, Thermo Fisher Scientific, Paisley, UK) was used as an endogenous control, and the corresponding commercial primer sequences [60,61], namely ALPL (Hs01029144_m1, Applied Biosystems, Thermo Fisher Scientific, Paisley, UK), COL1A1 (Hs00164004_m1,), BGLAP (Hs01587814_g1, Applied Biosystems, Thermo Fisher Scientific, Paisley, UK), and RUNX-2 (Hs00231692_m1,Applied Biosystems, Thermo Fisher Scientific, Paisley, UK) were added to a total reaction volume of 10 µL. The qPCR was carried out using the Applied Biosystems 7900HT Fast RT PCR system, (Thermo Fisher Scientific, Paisley, UK) and consisted of 40 cycles (95 • C for 15 s, 60 • C for 30 s, and 72 • C for 40 s) after an initial denaturation step (50 • C for 2 min).…”

Dietary Bioactives: Their Role in the Prevention and Treatment of Cardiovascular and Metabolic Bone Diseases

“…In this context, the Special Issue (SI) "Dietary Bioactives: Their Role in the Prevention and Treatment of Cardiovascular and Metabolic Bone Diseases" has published nine novel papers on this topic [7][8][9][10][11][12][13][14][15]. In detail, the SI includes: one narrative review paper, one crosssectional analysis, three pre-clinical animal studies, three in vitro experimental approaches and one ex vivo approach.…”

“…Subsequently, the specific mechanism of Vitamin K2 in bone health was also addressed in an in vitro study [7]. Specifically, the efficacy of Vitamin K2 in improving the functions of osteoblasts isolated from osteoporotic patients was demonstrated.…”

“…Using an animal model of ovariectomized-induced osteoporotic mice, the authors identified scopolin as the candidate bioactive compound extracted from Lycii radicis cortex capable of preventing and treating osteoporosis [13]. Finally, in the bone health field, the In this context, the Special Issue (SI) "Dietary Bioactives: Their Role in the Prevention and Treatment of Cardiovascular and Metabolic Bone Diseases" has published nine novel papers on this topic [7][8][9][10][11][12][13][14][15]. In detail, the SI includes: one narrative review paper, one crosssectional analysis, three pre-clinical animal studies, three in vitro experimental approaches and one ex vivo approach.…”