Confocal imaging of mouse mandibular condyle cartilage

Abstract

Mice are commonly used to study the temporomandibular joint (TMJ) and to model human TMJ disease. However, evaluating TMJ pathology in mice using standard histologic methods is time consuming, labor intensive, and dependent upon investigators’ expertise at consistently orienting and sectioning across tiny specimens. We describe a method that uses confocal microscopy to rapidly and reliably assess indicators of mandibular condyle cartilage pathology in mice. We demonstrate the utility of this method for detecting abnormalities in chondrocyte distribution in mice lacking lubricin (Prg4), the major boundary lubricant of articular cartilage. We further show that the method can provide information about recombination sites and efficiency in mandibular cartilage for Cre-driver strains. Because specimen preparation and data acquisition with confocal microscopy are simple and fast, the method can serve as a primary screening tool for TMJ pathology, before proceeding to complicated, time consuming, secondary analyses.

FGF signaling patterns cell fate at the interface between tendon and bone

“…5E,E′,G,G′). This is consistent with studies showing that the condyle is composed of an inner core of cartilage surrounded by fibrocartilage (Chen et al, 2012;He et al, 2017;Hinton and Carlson, 2005). In the Wnt1-Cre; Fgfr2 flx/flx angular process, Scx-GFP was reduced in the perichondrial layer and Scx + cells were restricted to a small layer around the core cartilage (n=3) (Fig.…”

Dwarfism in homozygous Agc1CreERT mice is associated with decreased expression of aggrecan

“…Several investigators have reported the use of Agc Cre model in their studies. Two articles have clearly indicated the use of Agc +/Cre mice (He et al 2017; Jing J et al 2013). One article reported the use of Agc Cre/Cre mice for their analysis (Maihiot et al, 2015).…”

“…Tamoxifen treatment results in nuclear translocation of the Cre-ERT fusion protein and subsequent excision of a floxed gene. Several studies have utilized the Agc Cre model to investigate the role of target genes in developing cartilage tissue (Shen et al, 2017; Liao et al, 2017; He et al, 2017; Hu et al, 2017; Sinha et al, 2017; Jing et al 2016; Liu et al, 2015; Maihiot et al, 2015; Zhou et al 2014; Ono et al, 2014; Jing et al 2014; 2013; Henry et al, 2012). Prior to breeding with our floxed mice, we noted variable weight and size among the Agc Cre littermates.…”

Dephosphorylation of the NPR2 guanylyl cyclase contributes to inhibition of bone growth by fibroblast growth factor

“…Other groups have used fluorescence microscopy to quantify chondrocyte movement, division, and volume in live avian growth plate cartilage ( Li et al, 2015 ), and to measure chondrocyte density in fixed mouse mandibular cartilage ( He et al, 2017 ). However, the methods that we have developed for imaging the growth plate of mammalian bones are unique in that they allow rapid manipulation of the chemical environment surrounding the growth plate and real-time measurements of changes in signaling pathways within the intact tissue.…”