[Construction of human telomerase reverse transcriptase periodontal ligament cell line mediated by adenovirus].

OBJECTIVE: This study aims to establish an effective and stable periodontal ligament cell line stably expressing human telomerase reverse transcriptase (hTERT) gene by using the adenovirus method. METHODS: Polymerase chain reaction (PCR) was used to amplify the full length of hTERT gene to construct recombinant adenovirus plasmid pAd-pshuttle-cmv-hTERT. Packaged adenovirus particles were used for infection of human periodontal ligament cells. The expression levels of hTERT and osteogenic genes, such as alkaline phosphatase, Runt-related transcription factor 2, bone sialoprotein, osteocalcin, osteopontin, and collagen Ⅰ mRNA, were detected by quantitative real-time PCR (qRT-PCR). The ability of osteogenic differentiation was observed by alizarin red staining, and the cell proliferation was determined by CCK-8. RESULTS: Adenovirus particles containing the hTERT gene were successfully constructed and infected with periodontal ligament cells. The infected cells were similar to normal periodontal ligament cells. The qRT-PCR results showed that hTERT and osteogenesis-associated genes were highly expressed in the periodontal ligament cell lines constructed by adenoviruses. Alizarin red staining showed that the periodontal ligament cell line had strong osteogenic differentiation capability. CCK-8 showed that the periodontal ligament cell line had strong proliferation capability. CONCLUSIONS: The human periodontal ligament cell line with high efficiency and stable expression of hTERT was established by the adenovirus method, thereby providing an ideal cell line for studying the mechanism of periodontal regeneration.

A visible-light-activated rhodium complex in enantioselective conjugate addition of α-amino radicals with Michael acceptors.

We report an efficient enantioselective conjugate addition of photogenerated α-amino radicals to Michael acceptors catalyzed by a newly prepared chiral-at-metal rhodium complex. This protocol shows that a single Rh(iii) complex can serve not only as a Lewis acid but also as a photoredox catalyst to control the stereoselectivity during the bond formation.

Chiral Rhodium(III) Complex-Catalyzed Cascade Michael-Alkylation Reactions: Enantioselective Synthesis of Cyclopropanes.

Chiral Rh(III) complex catalyzed highly efficient enantioselective cyclopropanation of α,ß-unsaturated 2-acyl imidazoles or pyridine with 2-bromomalonate is developed to generate corresponding multisubstituted cyclopropanes in 70-99% yields with 93→99% enantioselectivity. The proficiency of the process is also demonstrated in gram scale reaction maintaining same reactivity and selectivity level in lower catalyst loading. Moreover, the developed methodology is applicable in challenging synthesis of biscyclopropane scaffold with 97% ee in a single operation.

Rhodium-Catalyzed Regio- and Stereoselective [2 + 2] Cycloaddition of Allenamides.

A highly regio- and stereoselective Rh-catalyzed intermolecular head-to-head [2 + 2] cycloaddition of allenamides was developed. The intermolecular cycloadducts, trans-dimethylenecyclobutane-1,2-diamine derivatives, were achieved in good yields with high regioselectivity and stereoselectivity.