Long-Term Extensive Ectopic Hair Growth on the Spinal Cord of Mice from Transplanted Whisker Follicles

Median lingual hair heterotopia associated with pyogranulomatous glossitis in a Labrador retriever: Surgical treatment using carbon-dioxide laser

A 9-year-old male Labrador retriever dog was presented with dysphagia and presence of hairs on the tongue. Buccal examination revealed ulcerative glossitis and lingual hairs along the midline. Ultrasound and magnetic resonance imaging of the tongue showed multiple hair shafts contained in a proliferative tissue along the midline and extending in a fistulous tract towards the right ventral aspect of the tongue at mid-length. Surgical excision was completed using a carbon-dioxide laser. Histopathological examination revealed a pyogranulomatous inflammation centered on growing hairs, confirming the diagnosis of glossitis and lingual hair heterotopia. At 10 mo after surgery, all clinical signs and glossitis had disappeared despite partial recurrence of hair on the dorsal sulcus and in the sublingual fistula. Key clinical message: Although lingual hair heterotopia usually has no clinical repercussions, associated ulcerative lesions should support imaging and biopsy.Resection of the lesion using a carbon-dioxide laser resulted in a good outcome in this case, but recurrent hair growth is possible.

Protocols for Gelfoam(®) Histoculture of Hair-Shaft-Producing Mouse Whisker Follicles Containing Nestin-GFP-Expressing Hair-Follicle-Associated Pluripotent (HAP) Stem Cells for Long Time Periods

Gelfoam(®)-histocultured whisker follicles from nestin-driven-green fluorescent protein (ND-GFP) mice produced growing pigmented and unpigmented hair shafts. Hair-shaft length increased rapidly by day 4 and continued growing until at least day 12 after which the hair-shaft length was constant. By day 63 in histoculture, the number of ND-GFP hair follicle-associated pluripotent (HAP) stem cells increased significantly and the follicles were intact. Three-dimensional Gelfoam(®) histoculture of hair follicles can provide a very long-term period for evaluating novel agents to promote hair growth.

Protocols for Ectopic Hair Growth from Transplanted Whisker Follicles on the Spinal Cord of Mice

Isolated whisker follicles from nestin-driven green fluorescent protein (ND-GFP) mice, containing hair-associated pluripotent (HAP) stem cells, were histocultured in three dimensions on Gelfoam(®) for 3 weeks for subsequent transplantation to the spinal cord in order to heal an induced injury with the HAP stem cells. The hair shafts were removed from Gelfoam(®)-histocultured whisker follicles, and the remaining parts of the whisker follicles, containing GFP-nestin-expressing (HAP) stem cells, were transplanted into the injured spinal cord of nude mice, along with the Gelfoam(®). After 90 days, the mice were sacrificed and the spinal cord injuries were observed to have healed. ND-GFP expression was intense at the healed area of the spinal cord, as observed by fluorescence microscopy, demonstrating that the HAP stem cells were involved in healing the spinal cord. The transplanted whisker follicles produced remarkably long hair shafts in the spinal cord over 90 days and curved and enclosed the spinal cord. This result changes our concept of hair growth, demonstrating it is not limited to the skin and that hair growth appears related to HAP stem cells as both increased in tandem on the spinal cord.