Butyrate-treatment induces gingival epithelial cell death in a three-dimensional gingival-connective tissue hybrid co-culture system.

Three-dimensional (3D) cell culture systems are reported to be more physiologically similar to the in vivo state than 2-dimensional (2D) models, which are extensively employed in periodontal research. Herein, we developed a 3D gingival tissue model with both epithelial and lamina propria layers using human gingival epithelial Ca9-22 cells and primary gingival fibroblasts. The epithelial layer of the developed 3D gingival tissue culture was treated with butyrate, a metabolite of oral bacteria, and the treatment induced the release of damage-associated molecular patterns, such as DNA and Sin3A associated protein 130 kDa (SAP130). Taken together, butyrate exposure to the epithelium of 3D gingival epithelial-connective tissue hybrid systems could induce epithelial cell death and the subsequent release of damage-associated molecular patterns.

Asymmetrical organization of oral structures in the primary and secondary somatosensory cortices in rats: An optical imaging study.

In rodents, the representation of the body surface in the primary somatosensory cortex (S1) forms a mirror image along the ventral border of the S1 in the secondary somatosensory cortex (S2). Sensory information from the oral region is processed in the S1 and the border region between the S2 and insular oral region (IOR). We examined the relationship between somatosensory representations in the S1 and S2/IOR using optical imaging with a voltage-sensitive dye in urethane-anesthetized rats. In reference to the rhinal fissure and middle cerebral artery, we made a somatosensory map by applying electrical or air puff stimulation. The initial neural excitation in the S1 to facial structures, including the eyebrow, cornea, pinna, whisker pad, nasal tip, and nasal mucosa, spread toward the ventral area, putatively the S2. The initial cortical responses in the S1 to oral structures, including the lower lip, tongue, and teeth, were spatially separated from those in the S2/IOR. The representation of the tongue center, tongue tip, mandibular molar pulp, mandibular incisor pulp, and mandibular incisor periodontal ligament were almost linearly arranged from caudal to rostral in both S1 and S2/IOR. The lower lip was represented in the dorsal area from the representation of teeth and tongue in both S1 and S2/IOR. The representations of maxillary teeth were caudal and dorsal to the representations of mandibular teeth in the S1 and S2/IOR, respectively. These results suggest that the representation of oral structures in the S1 formed a non-mirror image, not a mirror image, in the S2/IOR.