In vitro differentiation of human amniotic epithelial stem cells into keratinocytes regulated by OPN3.

Human amniotic epithelial stem cells (hAESCs) are regarded as potential alternatives to keratinocytes (KCs) used for skin wound healing. Light is an alternative approach for inducing stem cell differentiation. Opsins (OPNs), a family of light-sensitive, G protein-coupled receptors, play a multitude of light-dependent and light-independent functions in extraocular tissues. However, it remains unclear whether the light sensitivity and function of OPNs are involved in light-induced differentiation of hAESCs to KCs. Herein, we determine the role of OPNs in differentiation of hAESCs into KCs through cell and molecular biology approaches in vitro. It is shown that mRNA expression of OPN3 in the amniotic membrane and hAESCs was higher than the other four primary OPNs by RT-qPCR analysis. Changes in OPN3 gene expression had a significant impact on cell proliferation, stemness and differentiation capability of hAESCs. Furthermore, we found a significant upregulation of OPN3, KRT5 and KRT14 with hAESCs treated at 3 × 33 J/cm2 irradiation from blue-light LED. Taken together, these results suggest that OPN3 acts as a positive regulator of differentiation of hAESCs into KCs. This study provides a novel insight into photosensitive OPNs associated with photobiomodulation(PBM)-induced differentiation in stem cells.

Synthesis of 3-Oxo Quinolines by Cyclization Using Lignin Models and 2-Aminobenzyl Alcohols.

Phenoxy acetophenones were usually employed as ß-O-4' lignin models for chemical conversion. Herein, an iridium-catalyzed dehydrogenative annulation between 2-aminobenzylalcohols and phenoxy acetophenones was demonstrated to prepare valuable 3-oxo quinoline derivatives, which are hard to prepare using previous methods. This operationally simple reaction tolerated a wide scope of substrates and enabled successful gram-scale preparation.

Lignin-derived new hydrogen donors for photoinitiating systems in dental materials.

OBJECTIVES: The aim of this study is to develop amine free photo-initiating system (PIs) for the photopolymerization of dental methacrylate resins, using seven new hydrogen donors HDA-HDG derived from ß-O-4 lignin model. METHODS: Seven experimental CQ/HD PIs were formulated with Bis-GMA/TEGDMA (70 w%/30 w%). CQ/EDB system was chosen as the comparison group. FTIR-ATR was used to monitor the polymerization kinetics and double bond conversion. Bleaching property and color stability were evaluated using a spectrophotometer. Molecular orbitals calculations were used to demonstrate C-H bond dissociation energies of the novel HDs. Depth of cure of the HD based systems were compared to the EDB based one. Cytotoxicity was also studied by CCK8 assay using tissue of mouse fibroblasts (L929 cells). RESULTS: Compared to CQ/EDB system, the new CQ/HD systems show comparable or better photopolymerization performances (1 mm-thick samples). Comparable or even better bleaching properties were also obtained with the new amine-free systems. Comparing to EDB, all HDs exhibited significantly lower C-H bond dissociation energies by molecular orbitals calculations. Groups with new HD showed higher depth of cure. OD and RGR values were similar to that of the CQ/EDB group, ensuring the feasibility of the new HDs in dental materials. CLINICAL SIGNIFICANCE: The new CQ/HD PI systems could be potentially useful in dental materials, presenting improvements in restorations' esthetic and biocompatibility.

Functionality-Directed Regio- and Enantio-Selective Olefinic C-H Functionalization of Aryl Alkenes.

Aryl alkenes represents one of the most widely occurring structural motif in countless drugs and natural products, and direct C-H functionalization of aryl alkenes provides atom- step efficient access toward valuable analogues. Among them, group-directed selective olefinic α- and ß-C-H functionalization, bearing a directing group on the aromatic ring, has attracted remarkable attentions, including alkynylation, alkenylation, amino-carbonylation, cyanation, domino cyclization and so on. These transformations proceed by endo- and exo-C-H cyclometallation and provide aryl alkene derivatives in excellent site- stereo-selectivity. Enantio-selective α- and ß- olefinic C-H functionalization were also covered to synthesis axially chiral styrenes.

The effects of missense OPN3 mutations in melanocytic lesions on protein structure and light-sensitive function.

Opsin 3 (OPN3), a member of the light-sensitive, retinal-dependent opsin family, is widely expressed in a variety of human tissues and plays a multitude of light-dependent and light-independent roles. We recently identified five missense variants of OPN3, including p. I51T, p. V134A, p. V183I, p. M256I and p. C331Y, in human melanocytic tumours. However, it remains unclear how these OPN3 variants affect OPN3 protein structure and function. Herein, we conducted structural and functional studies of these variant proteins in OPN3 by molecular docking and molecular dynamics simulations. Moreover, we performed in vitro fluorescence calcium imaging to assess the functional properties of five single-nucleotide variant (SNV) proteins using a site-directed mutagenesis method. Notably, the p. I51T variant was not able to effectively dock with 11-cis-retinal. Additionally, in vitro, the p. I51T SNVs failed to induce any detectable changes in intracellular Ca2+ concentration at room temperature. Taken together, these results reveal that five SNVs in the OPN3 gene have deleterious effects on protein structure and function, suggesting that these mutations, especially the p. I51T variant, significantly disrupt the canonical function of the OPN3 protein. Our findings provide new insight into the role of OPN3 variants in the loss of protein function.

Ruthenium-catalyzed C-H amination of aroylsilanes.

Acylsilane represents a valuable synthon in synthetic chemistry. We report on ruthenium(ii)-catalyzed ortho-C-H amination of aroylsilanes to provide facile access to synthetically useful imidobenzoylsilanes and tosyl-amidobenzoylsilanes. The protocols, with broad substrate scope and excellent functional group tolerance, are enabled with the weak chelation-assistance of acylsilane via C-H cyclometallation.