Abstract：
BACKGROUND: Recent studies highlighted the presence of anti-α-Gal antibodies in patients implanted with commercial bioprosthetic heart valves (BHVs). BHVs expose residual α-Gal xenoantigen and their recognition by the circulating anti-Gal antibodies leads to opsonization of the device\'s tissue component with the consequent triggering of a deterioration pathway that culminates with calcification. Small animal models such as mice and rats have been broadly involved in the in vivo testing of biomaterials by subcutaneous implantation, especially for the effectiveness of BHVs anti-calcific treatments. However, since models employed for this purpose express α-Gal antigen, the implantation of BHVs\' leaflets does not elicit a proper immunological response, so the calcification propensity may be dramatically underestimated.
METHODS: An α-Gal knockout (KO) mouse model has been created, using the CRISP/Cas9 approach, and adopted to assess the calcification potential of commercial BHVs leaflets through the surgical implantation in the back subcutis area. Calcium quantification was performed by inductively coupled plasma analysis; immune response against the BHVs leaflets and α-Gal silencing was evaluated through immunological assays.
RESULTS: Two months after the implantation of commercial BHV leaflets, the anti-Gal antibody titers in KO mice doubled when compared with those found in wild-type (WT) ones. Leaflets explanted from KO mice, after one month, showed a four-time increased calcium deposition concerning the ones explanted from WT. The degree of silencing of α-Gal varied, depending on the specific organ that was assessed. In any case, the animal model was suitable for evaluating implanted tissue responses.
CONCLUSIONS: Such mouse model proved to be an accurate tool for the study of the calcific propensity of commercial BHVs leaflets than those hitherto used. Given its reliability, it could also be successfully used to study even other diseases in which the possible involvement of α-Gal has been observed.
METHODS: An α-Gal knockout (KO) mouse model has been created, using the CRISP/Cas9 approach, and adopted to assess the calcification potential of commercial BHVs leaflets through the surgical implantation in the back subcutis area. Calcium quantification was performed by inductively coupled plasma analysis; immune response against the BHVs leaflets and α-Gal silencing was evaluated through immunological assays.
RESULTS: Two months after the implantation of commercial BHV leaflets, the anti-Gal antibody titers in KO mice doubled when compared with those found in wild-type (WT) ones. Leaflets explanted from KO mice, after one month, showed a four-time increased calcium deposition concerning the ones explanted from WT. The degree of silencing of α-Gal varied, depending on the specific organ that was assessed. In any case, the animal model was suitable for evaluating implanted tissue responses.
CONCLUSIONS: Such mouse model proved to be an accurate tool for the study of the calcific propensity of commercial BHVs leaflets than those hitherto used. Given its reliability, it could also be successfully used to study even other diseases in which the possible involvement of α-Gal has been observed.
摘要：
背景：最近的研究强调了植入商业生物假体心脏瓣膜（BHV）的患者中存在抗α-Gal抗体。BHVs暴露残余的α-Gal异种抗原,其被循环的抗Gal抗体的识别导致装置组织成分的调理作用,随后引发恶化途径,最终导致钙化。小鼠和大鼠等小型动物模型已广泛参与皮下植入生物材料的体内试验,特别是对于BHVs抗钙化治疗的有效性。然而,因为用于此目的的模型表达α-Gal抗原，BHV小叶的植入不会引起适当的免疫反应，所以钙化倾向可能被大大低估了。
方法：已经创建了一个α-Gal基因敲除(KO)小鼠模型，使用CRISP/Cas9方法，并通过手术植入背部皮下组织区域来评估商业BHVs小叶的钙化潜力。通过电感耦合血浆分析进行钙定量；通过免疫测定评估针对BHVs小叶和α-Gal沉默的免疫反应。
结果：植入商业BHV小叶后两个月，与野生型（WT）小鼠相比，KO小鼠的抗Gal抗体滴度增加了一倍。从KO小鼠移植的小叶，一个月后,显示从WT移出的钙沉积增加了四倍。α-Gal的沉默程度各不相同，取决于评估的特定器官。无论如何,该动物模型适用于评估植入组织的反应.
结论：这种小鼠模型被证明是研究商业BHVs小叶钙化倾向的准确工具。鉴于其可靠性,它也可以成功地用于研究甚至观察到可能涉及α-Gal的其他疾病。
方法：已经创建了一个α-Gal基因敲除(KO)小鼠模型，使用CRISP/Cas9方法，并通过手术植入背部皮下组织区域来评估商业BHVs小叶的钙化潜力。通过电感耦合血浆分析进行钙定量；通过免疫测定评估针对BHVs小叶和α-Gal沉默的免疫反应。
结果：植入商业BHV小叶后两个月，与野生型（WT）小鼠相比，KO小鼠的抗Gal抗体滴度增加了一倍。从KO小鼠移植的小叶，一个月后,显示从WT移出的钙沉积增加了四倍。α-Gal的沉默程度各不相同，取决于评估的特定器官。无论如何,该动物模型适用于评估植入组织的反应.
结论：这种小鼠模型被证明是研究商业BHVs小叶钙化倾向的准确工具。鉴于其可靠性,它也可以成功地用于研究甚至观察到可能涉及α-Gal的其他疾病。
