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.

An improved animal model of orthotopic liver transplantation in swine

Objective: To establish a swine model of orthotopic liver transplantation (OLT) which has high standardization, superior reproducibility and stability. Methods: The rate of success, reproducibility and stability were investigated on the modification of OLTs in closed miniature swine with series of improvements. Results: 20 OLTs were performed on the basis of improvements in experimental animals, surgical procedures and operative monitorings. The mean operation time and anhepatic phase was (181±25.8) and (28.4±3.2) min respectively, which were significantly shorter than those of the previous reports. Liver function of the animals recovered shortly after operation. One-week survival rate was 90%, and 15 animals survived more than 1 month. The incidence of vascular and biliary complications was lower in animals with long-term survival. Conclusion: The improved animal model of OLTs in swine is easy to operate with high standardization and rate of success, superior reproducibility and stability. It is an ideal model for series studies related to liver transplantation in big animals.

TECA hybrid artificial liver support system in treatment of acute liver failure

AIM: To assess the efficacy and safety of TECA type hybrid artificial liver support system (TECA-HALSS) in providing liver function of detoxification, metabolism and physiology by treating the patients with acute liver failure (ALF). METHODS: The porcine liver cells (1-2) x 10(10) were separated from the Chinese small swine and cultured in the bioreactor of TECA-BALSS at 37.0 degrees C and circulated through the outer space of the hollow fiber tubes in BALSS. The six liver failure patients with various degree of hepatic coma were treated by TECA-HALSS and with conventional medicines. The venous plasma of the patients was separated by a plasma separator and treated by charcoal adsorbent or plasma exchange. The plasma circulated through the inner space of the hollow fiber tubes of BALSS and mixed with the patients' blood cells and flew back to their blood circulation. Some small molecular weight substances were exchanged between the plasma and porcine liver cells. Each treatment lasted 6.0-7.0 h. Physiological and biochemical parameters were measured before,during and after the treatment. RESULTS: The average of porcine liver cells was (1.0-3.0) x 10(10) obtained from each swine liver using our modified enzymatic digestion method. The survival rate of the cells was 85%-93% by trypan blue stain and AO/PI fluorescent stain. After cultured in TECA-BALSS bioreactor for 6 h, the survival rate of cells still remained 70%-85%. At the end of TECA-HALSS treatment, the levels of plasma NH(3), ALT, TB and DB were significantly decreased. The patients who were in the state of drowsiness or coma before the treatment improved their appetite significantly and regained consciousness, some patients resumed light physical work on a short period after the treatment.One to two days after the treatment, the ratio of PTA increased warkedly. During the treatment, the heart rates, blood pressure, respiration condition and serum electrolytes (K(+), Na(+) and Cl(-)) were stable without thrombosis and bleeding in all the six patients. CONCLUSION: TECA-HALSS treatment could be a rapid, safe and efficacious method to provide temporary liver support for patients with ALF.

Efficacy and safety of therapeutic angiogenesis from direct myocardial administration of an adenoviral vector expressing vascular endothelial growth factor 165

OBJECTIVE: To investigate whether direct administration of adenoviral vectors (Ad) containing the complementary deoxyribonucleic acid (cDNA) of vascular endothelial growth factor 165 (Ad-VEGF165) induces porcine coronary collateral vessel formation, improves regional myocardial perfusion and function and is safe. METHODS: Three weeks after miniature swine underwent left thoracotomy and placement of an Ameroid constrictor on the left circumflex coronary artery (LCX), Ad-VEGF165 (n = 6) or the control, Ad expressing beta-galactosidase cDNA (Ad-Gal, n = 6), was directly administered into the ischemic myocardium in the circumflex distribution. All animals were sacrificed 4 wk after the second surgery. Myocardial perfusion and function were assessed by electrocardiogram-gated single photon emission computed tomography (GSPECT) imaging. Ex vivo coronary angiography was performed to examine collateral vessels. Toxicity was assessed by blood analyses on the day just before (day 0) and on day 1, 3, 7, 28 after vector delivery and by vascular, myocardial and liver histology after sacrifice. RESULTS: GSPECT imaging 4 wk after administration of Ad-VEGF165 demonstrated significant reduction in ischemic area (P

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.