To investigate the expression of the mTORC1 signaling pathway during the osteogenic differentiation of mouse bone marrow mesenchymal cells (BMMSCs) under cyclic uniaxial tension and explore its possible role.

The BMMSCs of mice were affected by uniaxial dynamic tensile force. Western blot was used to detect the expression changes of major molecules (mTOR, Raptor, S6K) in the endogenous mTORC1 signaling pathway at 0, 1, 2, 4, and 8 hours after stretching. Chemical colorimetry, ELISA and PCR were used to detect alkaline phosphatase (ALP), osteocalcin (OCN) and Runx2 mRNA, respectively. Then, inhibition, activation and control groups were established by administration of the drugs PP242, MHY1485 and PBS, respectively. Two hours after the stress, the expression of S6K was detected by western blot, and the expression of the osteogenic signal was continuously detected by the above methods.

Western blot analysis showed that the main molecules of the mTORC1 signaling pathway were all expressed within 8 hours after traction, and the highest expression was 2 hours after the stress. Compared with those in the control group, the ALP activity and OCN expression decreased and the Runx2 mRNA levels increased after the mTORC1 signal pathway was inhibited (P < 0.001); ALP activity and OCN expression increased after the mTORC1 signal pathway was activated, while the Runx2 mRNA levels decreased (P < 0.001).

The mTORC1 signaling pathway participates in the osteogenic differentiation of mouse BMMSCs under tension. The osteogenesis of BMMSCs under cyclic uniaxial tension would be enhanced if the mTORC1 signaling pathway was activated.

To observe the clinical effects of direct current iontophoresis (DCI) of triamcinolone acetonide (TA) on treatment of oral submucous fibrosis.

Fifty-one patients were randomly divided in group A (n＝25), which underwent local submucous injection with TA (20 mg for each side) once a week for 8 weeks, and group B (n＝26), which underwent local TA administration by DCI (20 mg for each side) for 8 weeks, follow-up was performed 12 weeks after treatment. The distances between the upper and lower central incisors were recorded. The visual analogue scale (VAS) was used to evaluate the pain caused by the two treatments. The Oral Health Impact Profile (OHIP)-14 was used to assess the entire effect of treatments.

At 8 weeks of treatment, the mouth opening was in-creased by 3.25 ± 0.77 mm in group A and 3.76 ± 0.88 mm in group B (P < 0.05). At 20 weeks after treatment, the mouth opening was increased by 2.61 ± 0.62 mm in group A and 2.53 ± 0.52 mm in group B (P>0.05). After the first treatment, the VAS score of group A was 7.88 ± 0.80, and the VAS score of group B was 2.47 ± 0.64, resulting in a statistically significant difference (P < 0.001). After the last treatment, the VAS score was 7.29 ± 0.53 in group A and 1.77 ± 0.48 in group B, resulting in a statistically significant difference (P < 0.001). The VAS scores of the two groups were decreased after treatment, and the difference between groups was statistically significant (P < 0.001). The OHIP-14 score of patients in group A before treatment was 31.44 ± 2.55, while that in group B was 32.04 ± 2.20 (P>0.05). At 20 weeks after treatment, the score in group A was 13.52 ± 3.31 and that in group was 12.04 ± 2.84 (P>0.05). The OHIP-14 scores of the two groups were significantly decreased before and after treatment, and the difference between groups was statistically significant (P < 0.001).

The results suggest that local TA administration by DCI might be a promising method for treatment in the early and middle disease periods in OSF patients.