Retinoic acid increases the effect of bone morphogenetic protein type 2 on osteogenic differentiation of human adipose-derived stem cells

Abstract Bone morphogenetic protein type 2 (BMP-2) and retinoic acid (RA) are osteoinductive factors that stimulate endogenous mechanisms of bone repair which can be applied on management of osseous defects in oral and maxillofacial fields. Objective Considering the different results of RA on osteogenesis and its possible use to substitute/potency BMP-2 effects, this study evaluated the outcomes of BMP-2, RA, and BMP-2+RA treatments on in vitro osteogenic differentiation of human adipose-derived stem cells (ASCs) and the signaling pathway(s) involved. Material and Methods ASCs were treated every other day with basic osteogenic medium (OM) alone or supplemented with BMP-2, RA, or BMP-2+RA. Alkaline phosphatase (ALP) activity was determined using the r-nitrophenol method. Extracellular matrix mineralization was evaluated using von Kossa staining and calcium quantification. Expression of osteonectin and osteocalcin mRNA were determined using qPCR. Smad1, Smad4, phosphorylated Smad1/5/8, BMP-4, and BMP-7 proteins expressions were analyzed using western blotting. Signaling pathway was evaluated using the IPA® software. Results RA promoted the highest ALP activity at days 7, 14, 21, and 28, in comparison to BMP-2 and BMP-2+RA. BMP-2+RA best stimulated phosphorylated Smad1/5/8 protein expression at day 7 and Smad4 expression at days 7, 14, 21, and 28. Osteocalcin and osteonectin mRNA expressions were best stimulated by BMP-2+RA at day 7. Matrix mineralization was most improved by BMP-2+RA at days 12 and 32. Additionally, BMP-2+RA promoted the highest BMP signaling pathway activation at days 7 and 14, and demonstrated more activation of differentiation of bone-forming cells than OM alone. Conclusions In summary, RA increased the effect of BMP-2 on osteogenic differentiation of human ASCs.

Prevention of antibiotic-associated metabolic syndrome in mice by intestinal alkaline phosphatase.

AIMS: To examine whether co-administration of intestinal alkaline phosphatase (IAP) with antibiotics early in life may have a preventive role against metabolic syndrome (MetS) in mice. METHODS: A total of 50 mice were allocated to four treatment groups after weaning. Mice were treated with azithromycin (AZT) ± IAP, or with no AZT ± IAP, for three intermittent 7-day cycles. After the last treatment course, the mice were administered a regular chow diet for 5 weeks and subsequently a high-fat diet for 5 weeks. Body weight, food intake, water intake, serum lipids, glucose levels and liver lipids were compared. 16S rRNA gene pyrosequencing was used to determine the differences in microbiome composition. RESULTS: Exposure to AZT early in life rendered mice susceptible to MetS in adulthood. Co-administration of IAP with AZT completely prevented this susceptibility by decreasing total body weight, serum lipids, glucose levels and liver lipids to the levels of control mice. These effects of IAP probably occur as a result of changes in the composition of specific bacterial taxa at the genus and species levels (e.g. members of Anaeroplasma and Parabacteroides). CONCLUSIONS: Co-administration of IAP with AZT early in life prevents mice from susceptibility to the later development of MetS. This effect is associated with alterations in the composition of the gut microbiota. IAP may represent a novel treatment against MetS in humans.

Lethal hypophosphatasia successfully treated with enzyme replacement from day 1 after birth.

UNLABELLED: Hypophosphatasia (HPP) is a rare metabolic bone disease caused by loss-of-function mutations in the gene ALPL encoding the tissue nonspecific alkaline phosphatase (TNSALP). There is a broad range of severity in the phenotype of HPP, and the most severe form exhibits perinatal lethality without mineralization of the skeleton. Here, we describe a female infant with perinatal lethal HPP diagnosed in utero. She was treated with a recombinant ALP (asfotase alfa) as an enzyme replacement therapy (ERT), which started from 1 day after birth. She required invasive ventilation immediately upon birth and demonstrated severe hypomineralization of whole body bone. Severe respiratory insufficiency was controlled by intensive respiratory care with high-frequency oscillation ventilation and nitric oxide inhalation and deep sedation just after birth. Bone mineralization improved with treatment; improvements were visible by 3 weeks of age and continued with treatment. Serum calcium levels decreased following treatment, resulting in hypocalcemia and convulsion, and calcium supplementation was required until 3 months of treatment. She was weaned from mechanical ventilation and has now survived more than 1 year. CONCLUSION: This case demonstrates the success of ERT in treating the severest HPP and highlights the importance of early diagnosis and intervention for these patients.