Exercise promotes osteogenic differentiation by activating the long non-coding RNA H19/microRNA-149 axis.

BACKGROUND: Regular physical activity during childhood and adolescence is beneficial to bone development, as evidenced by the ability to increase bone density and peak bone mass by promoting bone formation. AIM: To investigate the effects of exercise on bone formation in growing mice and to investigate the underlying mechanisms. METHODS: 20 growing mice were randomly divided into two groups: Con group (control group, n = 10) and Ex group (treadmill exercise group, n = 10). Hematoxylin-eosin staining, immunohistochemistry, and micro-CT scanning were used to assess the bone formation-related indexes of the mouse femur. Bioinformatics analysis was used to find potential miRNAs targets of long non-coding RNA H19 (lncRNA H19). RT-qPCR and Western Blot were used to confirm potential miRNA target genes of lncRNA H19 and the role of lncRNA H19 in promoting osteogenic differentiation. RESULTS: Compared with the Con group, the expression of bone morphogenetic protein 2 was also significantly increased. The micro-CT results showed that 8 wk moderate-intensity treadmill exercise significantly increased bone mineral density, bone volume fraction, and the number of trabeculae, and decreased trabecular segregation in the femur of mice. Inhibition of lncRNA H19 significantly upregulated the expression of miR-149 and suppressed the expression of markers of osteogenic differentiation. In addition, knockdown of lncRNA H19 significantly downregulated the expression of autophagy markers, which is consistent with the results of autophagy-related protein changes detected in mouse femurs by immunofluorescence. CONCLUSION: Appropriate treadmill exercise can effectively stimulate bone formation and promote the increase of bone density and bone volume in growing mice, thus enhancing the peak bone mass of mice. The lncRNA H19/miR-149 axis plays an important regulatory role in osteogenic differentiation.

Mitoxantrone-loaded BSA nanospheres and chitosan nanospheres for local injection against breast cancer and its lymph node metastases. I: Formulation and in vitro characterization.

Positively charged mitoxantrone (MTO) was absorbed by negatively charged blank bovine serum albumin (BSA) and chitosan (CS) nanospheres to form MTO-BSA-NS and MTO-CS-NS, respectively. In addition to other conditions, values of pH of every step were optimized. On optimized conditions, MTO-BSA-NS of a mean size of 77 nm with an encapsulation yield (EY) of (98.86+/-1.43)% [drug loading rate (DL) (19.82+/-0.29)%] and MTO-CS-NS of a mean size of 75 nm with an EY of (97.57+/-1.00)% [DL (9.78+/-0.10)%] were obtained. After lyophilization and sterilization by (60)Co, the mean size increased about 10% but no significant change was observed in EY and DL. Tests for in vitro release in physiological saline or physiological saline containing 0.5% (w/v) ascorbic acid by a dialysis bag showed sustained release and little burst effect.

Mitoxantrone-loaded BSA nanospheres and chitosan nanospheres for local injection against breast cancer and its lymph node metastases. II: Tissue distribution and pharmacodynamics.

Bovine serum albumin (BSA) and chitosan (CS) nanospheres of mitoxantrone (MTO) were comparatively evaluated in terms of tissue distribution, acute toxicity and therapeutic efficiency against breast cancer and its lymph node metastases. After local injection in rats, MTO nanospheres showed a slower elimination rate and a much higher drug concentration in lymph nodes compared with MTO solution, and a lower drug concentration in other tissues. There was no observed acute toxicity to the main tissues of Kunming mice after local injection of MTO-BSA-NS. Mild toxicity to liver and lung was observed for MTO-CS-NS, but, for MTO solution, severe toxicity to liver and lung and much lower number of white blood cells were observed. Human MCF-7 breast cancer in nude mice and animal model of P388 lymph node metastases in Kunming mice were applied to investigate the therapeutic efficiency. The inhibition rate of the nanospheres against breast cancer was much higher than that of MTO solution, and lymph node metastases were efficiently inhibited by the nanospheres, especially MTO-BSA-NS.