ethyl-cinnamate and Disease-Models--Animal

Orthodontic tooth movement is a complex biological process of altered soft and hard tissue remodeling as a result of external forces. In order to understand these complex remodeling processes, it is critical to study the tooth and periodontal tissues within their 3D context and therefore minimize any sectioning and tissue artefacts. Mouse models are often utilized in developmental and structural biology, as well as in biomechanics due to their small size, high metabolic rate, genetics and ease of handling. In principle this also makes them excellent models for dental related studies. However, a major impediment is their small tooth size, the molars in particular. This paper is aimed at providing a step by step protocol for generating orthodontic tooth movement and two methods for 3D imaging of the periodontal ligament fibrous component of a mouse mandibular molar. The first method presented is based on a micro-CT setup enabling phase enhancement imaging of fresh collagen tissues. The second method is a bone clearing method using ethyl cinnamate that enables imaging through the bone without sectioning and preserves endogenous fluorescence. Combining this clearing method with reporter mice like Flk1-Cre;TdTomato provided a first of its kind opportunity to image the 3D vasculature in the PDL and alveolar bone.

Topics: Animals; Biomechanical Phenomena; Cinnamates; Disease Models, Animal; Imaging, Three-Dimensional; Mandible; Mice; Molar; Periodontal Ligament; Tooth Movement Techniques; X-Ray Microtomography

Cardioprotection by salvage of the infarct-affected myocardium is an unmet yet highly desired therapeutic goal. To develop new dedicated therapies, experimental myocardial ischemia/reperfusion (I/R) injury would require methods to simultaneously characterize extent and localization of the damage and the ensuing inflammatory responses in whole hearts over time. Here we present a three-dimensional (3D), simultaneous quantitative investigation of key I/R injury-components by combining bleaching-augmented solvent-based non-toxic clearing (BALANCE) using ethyl cinnamate (ECi) with light sheet fluorescence microscopy. This allows structural analyses of fluorescence-labeled I/R hearts with exceptional detail. We discover and 3D-quantify distinguishable acute and late vascular I/R damage zones. These contain highly localized and spatially structured neutrophil infiltrates that are modulated upon cardiac healing. Our model demonstrates that these characteristic I/R injury patterns can detect the extent of damage even days after the ischemic index event hence allowing the investigation of long-term recovery and remodeling processes.

Topics: Animals; Biopsy; Cinnamates; Coronary Artery Bypass; Disease Models, Animal; Heart; Humans; Imaging, Three-Dimensional; Luminescent Agents; Luminescent Proteins; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Microscopy, Fluorescence; Myocardial Reperfusion Injury; Myocardium; Neutrophils; Red Fluorescent Protein