Cultivation of enteroids from fresh and cryopreserved bovine duodenal tissues

This study aimed to develop a method for intestinal tissue cryopreservation and resuscitation for enteroid cultivation. Two different types of tissues, fresh duodenal tissues (n = 3, from Angus steers) and duodenal tissues cryopreserved in 90% fetal bovine serum (FBS) and 10% dimethyl sulfoxide (DMSO; n = 3, from Holstein calves), were collected to develop enteroids. Crypts were isolated using 2 mM EDTA/phosphate-buffered saline from both fresh and cryopreserved tissues and embedded in basement membrane extract. Embedded crypts were seeded in a 24-well plate and cultured in IntestiCult Organoid Growth Medium (Mouse) with inhibitors cocktail and Primocin. The upper opening of crypts became sealed, and crypts formed sphere structures (i.e., enteroids) within 24 h. Primary (passage 0) enteroids showed budding crypt domains from d 3 of cultivation at the earliest. After 7 d of cultivation, enteroids were passaged in a new 24-well plate. Fragments from passaged d 7 enteroids also formed sphere structures within 24 h after seeding and showed budding crypt domains from d 3 of cultivation at the earliest. The area of enteroids was measured in each animal during d 1 to 7 in passage 0 and 1, and the area of enteroids derived from both tissues increased during d 1 to 7 in passage 0 and 1. The area increased from d 1 to 7 of cultivation, and the area of passage 1 was greater than that of passage 0. F-actin staining using phalloidin revealed that brush border microvilli were distributed on the luminal side of the enteroids. In conclusion, a cryopreserved solution consisting of FBS and DMSO is useful for cryopreservation and resuscitation of bovine intestine for enteroid cultivation. This method allows researchers to investigate intestinal function and health in the laboratory using enteroids derived from fresh and cryopreserved tissues collected from cattle.