脂肪前体细胞可能源自脂肪组织中的血管基质细胞、周细胞、内皮细胞，以及非脂肪组织来源的骨髓造血干细胞，但后二者存在很大争议。筋膜是连续分布的结缔组织，由大量胶原和弹性纤维组成，含有较多的纤维细胞和少量巨噬细胞、肥大细胞和脂肪细胞。筋膜和脂肪均起源于中胚层。人体内筋膜无处不在，可延伸于脂肪组织中；而脂肪分布广泛，能填充于筋膜层之间。与人的筋膜不同，大鼠肌肉筋膜几乎不含脂肪细胞，容易分离且不污染其它组织如脂肪。我们发现，离体培养的大鼠筋膜组织块和筋膜细胞能自发或诱导分化为脂肪细胞，分化效率很高。筋膜存在大量的脂肪前体细胞，提示筋膜可能是脂肪细胞的发源地。本课题拟研究，筋膜的脂肪前体细胞亚群的干细胞标志物特征；其在筋膜组织上的定位和分布特征；筋膜前脂肪细胞在不同的营养条件下如何分化，是否参与高脂饮食诱导的肥胖。我们期望这一研究能揭开筋膜前脂肪细胞的面纱，发现筋膜是脂肪细胞的另一来源。

Adult adipose precursor cells are thought to originate from stromal vascular cells, pericytes, and endothelial cells of blood vessels within adipose tissue, and also bone marrow cells resident in non-adipose tissue, although the last two types of adipocyte progenitors remain under debate. Fascia consists of particularly abundant collagen and elastic fibers and fibrocytes, and a few adipocytes and various migrating white blood cells and constitutes a continuous, elastic sheet of connective tissues that extends throughout the body. Fasciae form ubiquitous frameworks to penetrate and separate adipose tissue, and adipose tissue may form and localize between layers of fasciae. Our preliminary observations show that the fragment of fascial tissue and cells isolated from fascia are capable of spontaneous differentiation into adipocytes in culture in the absence of adipogenic inducers, and are more efficiently differentiated into adipocytes upon induction of adipogenesis. In this project, we select the fasciae of rat limbs as experimental samples, because the fascia in rat, different from the fascia in human, contains a less amount of mature adipocytes and is easily dissected from adjacent tissues. We aim to investigate the characteristics of the fascial preadipocytes by using stem cell surface markers and flow cytometry analysis, and identify localization and distribution of these adipocyte progenitors in situ in fasciae. We investigate the regulation of adipocyte differentiation of fascial progenitors in different physiological conditions, such as gender, age, fasting, and excessive nutrients. We also investigate whether adipocyte differentiation of fascial progenitors participates in the pathgenesis of high fat diet induced obesity. Fascia could be another origin of adipose tissue and adipocyte progenitors. We expect that this study could be able to uncover the veil on this novel type of preadipocytes resident in fascia.