Functional recovery by colon organoid transplantation in a mouse model of radiation proctitis.

Radiation proctitis is the collateral damage that occurs to healthy cells during radiation treatment of pelvic malignancies. Conservative treatment of radiation proctitis can mitigate inflammatory symptoms, but, to date, no therapeutic options are available for direct recovery of the damaged colonic epithelium. The present study assessed the ability of colon organoid-based regeneration to treat radiation proctitis. Radiation proctitis was induced in mice by irradiating their recta, followed by enema-based transplantation of mouse colon organoids. The transplanted colon organoids were found to successfully engraft onto the damaged rectal mucosa of the irradiated mice, reconstituting epithelial structure and integrity. Lgr5+ stem cells were shown to be pivotal to colon organoid mediated regeneration. Endoscopic examination showed the efficacy of localized transplantation of colon organoids with fibrin glue to irradiated sites. These findings provide useful insights into the use of colon organoid-based regenerative therapy for the treatment of radiation proctitis.

Effect of 808-nm Laser Photobiomodulation Treatment in Blepharitis Rat Model.

PURPOSE: Blepharitis, simply defined as eyelid inflammation, is one of the common ocular conditions associated with discomfort and irritation. Because blepharitis causes meibomian gland dysfunction and dry eye, this study aimed to confirm the effect of photobiomodulation (PBM) on blepharitis. METHODS: A total of 20 rats were randomly assigned to 4 equal groups, including control, blepharitis, PBM, and eye drop. Blepharitis was induced in rats by injecting complete Freund's adjuvant in the eyelid margins. PBM intervention was given every 3 days after blepharitis induction. Clinical signs including tear volume, tear breakup time (TBUT), meibomian gland swelling, fluorescein, telangiectasia, and meibomian gland secretion scores were measured every week, and the rats were killed for histological analysis after 4 weeks. Immunohistochemistry was performed to compare the level of inflammatory cytokines, interleukin-1ß and tumor necrosis factor-α, and terminal deoxynucleotidyl transferase dUTP nick end labeling staining on retina was performed to observe any retinal damage. RESULTS: Tear volume and TBUT increased with PBM intervention, and with improved eyelid swelling, corneal staining, telangiectasia, and meibomian gland secretion scores increased. Hematoxylin and eosin staining showed no structural abnormalities of meibomian gland caused by blepharitis induction. Immunohistochemistry revealed that the levels of inflammatory cytokines interleukin-1ß and tumor necrosis factor-α were lowered with PBM treatment in both eyelid and conjunctiva. Terminal deoxynucleotidyl transferase dUTP nick end labeling staining showed no retinal damage. CONCLUSIONS: Laser PBM at 808 nm was effective in alleviating ocular signs and controlling inflammation in blepharitis rat model. The in vivo results suggest that PBM has the potential to be used in treating blepharitis patients.