Commentary on “Mandible exosomal ssc-mir-133b regulates tooth development in miniature swine via endogenous apoptosis”

This report,"Mandible exosomal ssc-mir-133b regulates tooth development in miniature swine via endogenous apoptosis" by Li et al. is an important step forward in describing the factors that control tooth development in a large animal model. That many of the regulatory miRNA pathways have been elucidated in murine species have always begged the question as to how relevant they

Establishment of submandibular gland allotransplantation model in miniature swine

Background Autologous transplantation of the submandibular gland （SMG） into the temporal fossa with microvascular anastomosis has been successfully applied in severe xerophthalmia patients as a permanent tear substitute. However, severe xerophthalmia can be accompanied by salivary gland dysfunction, making such autotransplantation unsuitable. Therefore, SMG allotransplantation might be a solution. The aim of this study was to assess the technical feasibility of submandibular gland allotransplantation. Methods Twelve miniature swine were randomized to serve as donors or recipients. One SMG was transplanted between a donor and a recipient. The donor SMG was revascularized by microvascular anastomosis of its vascular pedicle to the recipient lingual artery and external jugular vein. The secretory duct was implanted into the vestibule of the mouth through a subcutaneous tunnel. No ilnmunosuppressive agent was administered. The results were assessed by visual inspection of the secretion, and histopathological examination of the transplanted SMG. Results Technically, all surgical procedures were successful. Clear secretion flowed out of the duct as soon as blood supply of the transplanted submandibular gland was reestablished. The secretion of the gland lasted for 5 days. As expected, an acute rejection reaction occurred after surgery because no immunosuppressive agents were used. Secretion from the transplanted SMG ceased within 5 days. Conclusions A model of SMG allotransplantation can be established in miniature swine. The technique of submandibular gland allotransplantation is feasible.

IRAK1, TRAF6 and AUF1 are involved in myocardial inflammatory response after coronary microembolization in miniature swines

Background Coronary microembolization （CME） is characterized by distal microvascular occlusion. However, the inflammatory mechanisms and therapeutic targets of CME are largely unknown. Methods A total of 11 Guangxi Bama miniature swines were divided into two groups： sham （n = 5） and CME （n = 6）. Microspheres were injected into the left anterior descending artery of the CME group to make an animal model of CME. The expres- sions of microRNA-146a （miR-146a） and IRAK1, TRAF6, and AUF1 in the myocardium were detected by qPCR. Results In the CME group, microspheres, microinfarction, and inflammatory cell infiltration were found under an optical microscope. The expression levels of miR-146a were low in both groups. After CME, the expression levels of IRAK1, TRAF6, and AUF1 in the CME group were upregulated compared with those in the sham group （P 〈 0.01;P 〈 0.05;P 〈 0.05, respectively）. Conclusions AUF1, IRAK1 and TRAF6, but not miR-146a, could be involved, in myocardium inflammation following CME.

Evidence of apoptotic smooth muscle cells in proliferative intima of injured arteries

OBJECTIVE: To investigate the occurrence and extent of apoptosis in the course of restenosis. METHODS: The experimental models of vessel narrowness and intima thickness were established in minipigs' iliac arteries by balloon injury and specimens were retrieved on the 1st, 3rd, 6th, 12th and 30th days for dynamic observation. Apoptotic smooth muscle cells (SMCs) were detected by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL). RESULTS: Apoptotic SMCs occurred only in the thickened intima 12 days after injury accompanied with the proliferative SMCs, the percentage of apoptosis was 1.94% +/- 0.42% on the 12th day and 1.36% +/- 0.31% on the 30th day respectively. The low frequency of apoptosis compared with the proliferative SMCs was a feature in the restenotic pathology. CONCLUSIONS: Apoptosis participates in the pathogenetic process of intimal thickening and its level was low compared with proliferation. The findings suggest that attempts to modulate apoptosis after vessel injury constitute a theoretical approach to the prevention of restenosis.