HDAC6 regulates dental mesenchymal stem cells and osteoclast differentiation.

BACKGROUND: Dental and periodontal tissue development is a complicated process involving a finely regulated network of communication among various cell types. Understanding the mechanisms involved in regulating dental mesenchymal stem cells (MSCs) and osteoclast cell differentiation is critical. However, it is still unclear whether histone deacetylase HDAC6 is involved in dental MSCs fate determination and osteoclast differentiation. METHODS: We used shRNA and siRNA knockdown to explore the role of HDAC6 in dental MSCs odontogenic differentiation and osteoclasts maturation. RESULTS: Based on HDAC6 knockdown dental MSCs, our data suggest that HDAC6 knockdown significantly increases alkaline phosphate activity and mineralized nodules formation. Additionally, mRNA expression of odontogenic marker genes (OSX, OCN, and OPN) was induced by HDAC6 knockdown. By using HDAC6 siRNA, we knocked down HDAC6 in osteoclast precursor RAW 264.7 cells. Our data suggests that HDAC6 knockdown significantly inhibited osteoclasts differentiation. Additionally, mRNA expression of osteoclast marker genes Trap, Mmp9, and Ctsk was decreased by HDAC6 knockdown. CONCLUSIONS: Our study demonstrated that HDAC6 plays an important role in regulating dental MSCs and osteoclasts differentiation.

Correlations between digit ratio and infertility in Chinese men.

BACKGROUND: Digit ratio, especially second to fourth digit ratio (2D:4D) is lower in men than in women. The ratios of digit may be established in utero and is negatively correlated with sperm counts and testosterone in men and positively correlated with estrogen in men and women. AIM: To study whether the digit ratio (especially 2D:4D) are associated with the a+b ratio of sperm number in Chinese populations. METHODS: Photocopies of the two hands of 268 men (controls: 72; patients: 196) and seminal parameters of masturbatory semen samples were collected. RESULTS: The mean values of digit ratio of the controls and the patients all presented a trend as 2D:3D<2D:4D<3D:4D<2D:5D<4D:5D<3D:5D; the patients have higher mean values than controls; significant variances of 2D:3D, 3D:4D (left: P<0.05; right: P ≤ 0.05) and 2D:4D (left: P<0.001; right: P<0.01) were found between two groups; there was a higher percentage of 2D>4D in the patients; the relationship between 2D:4D and a+b ratio of sperm number in the patients was significant (P<0.001). CONCLUSION: Digit ratio, especially 2D:4D in the left hand maybe one of the important markers of infertility in men for early diagnosis.

[Study on immune response in ICR mice by immunization with recombinant myophilin vaccine against Echinococcus granulosus].

OBJECTIVE: To investigate the immune response and the protection in mice induced by the recombinant myophilin protein of Echinococcus granulosus. METHODS: Thirty-six male ICR mice of 6-8 weeks old were randomly divided into groups A, B and C each with 12. The mice in the 3 groups were subcutaneously immunized with Eg myophilin protein, blank plasmid protein or PBS, respectively, by 3 times and challenged with protoscoleces of E. granulosus 2wk after the last vaccination. Mice were sacrificed 20wk after the infection, the hydatid cysts were collected for measuring the weight reduction. Spleens were obtained and the splenocytes were separated and cultured in vitro with EgAg or ConA stimulus for 4-5 h. The subsets of CD4+ and CD8+ T cells were measured by FACsort. The proliferation of splenocytes was determined by MTT method with blank plasmid and PBS as control. RESULTS: The average weight of the hydatid cysts in the immunized group decreased by 69.1% in comparison to the blank plasmid and PBS groups. The CD4+ subset [(29.7 +/- 0.9)%] and CD84+ subset [(9.7 +/- 0.8)%] in group A increased significantly than group C, [(11.6 +/- 1.4)%] and [(7.8 +/- 0.2)%] respectively (P < 0.01 or < 0.05). The ratio of CD4+/CD8+ subsets in group A (3.061 +/- 0.015) was also higher than group C (1.487 +/- 0.106) (P < 0.01). Without stimulation, the proliferation of T lymphocytes in group A(0.237 +/- 0.009) was higher than group C (0.159 +/- 0.005) (P < 0.01), with EgAg or ConA stimulus, it was also higher in group A than that of group C (P < 0.01). CONCLUSION: The recombinant myophilin protein of E. granulosus can induce the proliferation of splenocytes and Th1 response in mice, and the CD4+ T cells subset may bear a part in the induced protection against the challenge of protoscoleces.