Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, P. R. China.
Department of Basic Medical Sciences, Taizhou Central Hospital (Taizhou University Hospital), Taizhou, P. R. China.
FASEB J. 2022 Sep;36(9):e22510. doi: 10.1096/fj.202200408R.
Fat grafting is one of the most commonly applied procedure for soft-tissue repair. However, it remains unclear whether the type of adipose tissue would have any effects on fat graft survival. The present study aimed to determine fates of fat grafting of three different types of fat tissue. In this study, mice were randomly divided into three groups, white adipose tissue (WAT) group, beige adipose tissue (beige AT) group and brown adipose tissue (BAT) group. Before transplantation, donor mice were injected with rosiglitazone or phosphate-buffered saline (PBS). The WAT and BAT were obtained from PBS-treated mice while beige AT was obtained from the rosiglitazone-treated mice. Three types of fat tissue (150 mg each) were transplanted in three groups, respectively, and harvested at 2, 4 or 12 weeks. The BAT and beige AT contained smaller adipocytes and expressed higher level of uncoupling protein-1 gene. The retention rate of the transplanted fat was significantly higher for beige than for white fat, but was significantly lower for brown than for white fat. Transplanted brown fat was characterized by upregulated inflammation and high endoplasmic reticulum stress. By contrast, fat grafts in beige AT group showed the best adipogenic capacity, moderate inflammation level and superior angiongenesis. In vitro, under hypoxic condition, fewer apoptotic cells were found in beige adipocyte group than that in brown and white adipocyte group. Conditioned medium from brown adipocytes induced M1 polarization of RAW 264.7 macrophages while that from beige adipocytes effectively promoted M2 polarization. Therefore, we suggest that beige AT provides a new potential choice for fat grafting because of low inflammation and superior survival but BAT might not be ideal for fat grafting due to its poor survival.
脂肪移植是软组织修复中最常用的方法之一。然而，脂肪组织的类型是否会影响脂肪移植的存活尚不清楚。本研究旨在确定三种不同类型脂肪组织脂肪移植的命运。在这项研究中，小鼠被随机分为三组，白色脂肪组织（WAT）组、米色脂肪组织（beige AT）组和棕色脂肪组织（BAT）组。移植前，供体小鼠注射罗格列酮或磷酸盐缓冲液（PBS）。WAT 和 BAT 来自 PBS 处理的小鼠，而 beige AT 来自罗格列酮处理的小鼠。三种类型的脂肪组织（各 150mg）分别移植到三组中，分别在 2、4 或 12 周收获。BAT 和 beige AT 含有较小的脂肪细胞，并表达更高水平的解偶联蛋白 1 基因。与白色脂肪相比，米色脂肪的移植脂肪保留率明显更高，而棕色脂肪的保留率明显低于白色脂肪。移植的棕色脂肪表现出上调的炎症和高内质网应激。相比之下，beige AT 组的脂肪移植物具有最佳的成脂能力、适度的炎症水平和优越的血管生成。体外，在缺氧条件下，米色脂肪细胞组的凋亡细胞少于棕色和白色脂肪细胞组。来自棕色脂肪细胞的条件培养基诱导 RAW 264.7 巨噬细胞向 M1 极化，而来自 beige 脂肪细胞的条件培养基有效地促进 M2 极化。因此，我们建议 beige AT 是脂肪移植的一个新的潜在选择，因为它的炎症水平低，存活率高，但 BAT 可能不是脂肪移植的理想选择，因为它的存活率低。
