Despite decades of studies suggesting that the in vivo adipocyte progenitor resides within the vascular niche, the exact nature of this progenitor remains controversial because distinct studies have attributed adipogenic properties to multiple vascular cell types. Using Cre recombinases labeling distinct vascular lineages, we conduct parallel lineage tracing experiments to assess their degree of contribution to de novo adipogenesis. Although we detect occasional adipocytes that were lineage traced by endothelial or mural recombinases, these are rare events. On the other hand, platelet-derived growth factor receptor alpha (PDGFRα)-expressing adventitial or capsular fibroblasts make a significant contribution to adipocytes in all depots and experimental settings tested. Our data also suggest that fibroblasts transition to an intermediate beige adipocyte phenotype prior to differentiating to a mature white adipocyte. These observations, together with histological analyses revealing that adipose tissue fibroblasts express the mural cell marker PDGFRβ, harmonize a highly controversial field with implications for multiple human diseases, including the pandemic of obesity.

中文翻译：

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平行血统追踪研究将成纤维细胞确立为流行的体内脂肪细胞祖细胞。

尽管数十年的研究表明体内脂肪细胞祖细胞存在于血管壁中，但该祖细胞的确切性质仍存在争议，因为不同的研究已将脂肪形成特性归因于多种血管细胞类型。使用Cre重组酶标记不同的血管谱系，我们进行平行谱系追踪实验，以评估它们对新生脂肪形成的作用程度。尽管我们检测到偶然的由内皮或壁重组酶追溯到谱系的脂肪细胞，但这是罕见的事件。另一方面，表达血小板源性生长因子受体α（PDGFRα）的外膜或荚膜成纤维细胞在所有储库和实验环境中均对脂肪细胞做出重要贡献。我们的数据还表明，成纤维细胞在分化为成熟的白色脂肪细胞之前先过渡为中间的米色脂肪细胞表型。这些观察结果以及组织学分析表明，脂肪组织成纤维细胞表达壁细胞标记物PDGFRβ，使这一备受争议的领域协调发展，涉及多种人类疾病，包括肥胖症大流行。