Apocynin inhibits compressive force-induced apoptosis and autophagy of periodontal ligament stem cells.

OBJECTIVE: This study aimed to evaluate the effect of Apocynin on compressive force-induced apoptosis and autophagy in periodontal ligament stem cells (PDLSCs). MATERIALS AND METHODS: Periodontal ligament stem cells were subjected to a uniform compressive force of 2.0 g/cm2 for 24 h, without and with addition of 50, 100 and 200 µM Apocynin. Beclin-1 was overexpressed in PDLSCs. Flow cytometry was used to assess apoptosis and transmission electron microscopy was used to evaluate ultrastructural features of PDLSCs. Immunofluorescence was used to assess the levels of microtubule-associated protein 1 light chain 3 (LC3). The protein levels of B-cell lymphoma-2 (Bcl-2), Bcl-2 associated X (Bax), Caspase-3, LC3, and Beclin were determined by Western blot analysis. RESULTS: Compressive force of PDLSCs significantly increased apoptosis, Bax, Caspase-3, the number of autophagosome or autolysosomes, Beclin-1, the ratio of LC3 II/LC3 I, and decreased Bcl-2. Apocynin was shown to inhibit apoptosis and Beclin-1-mediated autophagy. Over-expression of Beclin-1 increased apoptosis and autophagy. CONCLUSIONS: Application of Apocynin attenuated long-term compressive force-induced apoptosis by regulating Beclin-1-mediated autophagy in PDLSCs. These results provide an alternative approach to improve orthodontic treatment outcomes for patients.

Direct C-H bond arylation of fluorenes with aryl chlorides catalyzed by N-heterocyclic carbene-palladium(II)-1-methylimidazole complex and further transformation of the products in a one-pot procedure.

We report here the NHC-Pd(II)-Im complex 1-catalyzed direct C-H bond functionalization of the C9 position of fluorenes with aryl chlorides and further transformation of the resulting products in a one-pot procedure. Under the optimal conditions, arylated fluorenes can be obtained in moderate to almost quantitative yields using various activated and unactivated (hetero)aryl chlorides as the arylating reagents. Furthermore, if the mixture from the arylation reaction is exposed to air, the C9-oxidized products can be obtained in acceptable to good yields in a one-pot procedure. In addition, alkyl groups can also be efficiently introduced to the above mixture from the arylation reaction, producing further C9-alkylated products in good to almost quantitative yields in a one-pot procedure, thus providing an expedient, inexpensive and practical strategy for the mono- and di-functionalization of fluorenes.