**4.2.3 HA, adipocytes and adipose tissue**

Adipose tissue in mammary glands is important for its secretory and endocrinal functions as well as metabolism, energy homeostasis and stem cell compartment. Adipocytes contribute to the mammary tissue ECM and this effect is at least partly regulated by HA. There are not many studies that focus on HA and its relationship to adipocytes, however, the importance of this polysaccharide on adipose-stromal interactions in the breast tissue is becoming apparent. For example, HA increases the crosslinking of collagen-HA matrices, supports proliferation and differentiation of pre-adipocytes and induces a higher proportion of cycling cells (Davidenko *et al*., 2010).

Chen *et al.* (2007) also showed that HA extends the lifespan, reduces cellular senescence and enhances differentiation potential of murine adipose-derived stromal cells (mADSCs) *in culture*. Collectively, these results provide preliminary evidence for a key role of HA in controlling the adipose component of the breast tissue and allude to a potential role of this regulation in BCA (Chen *et al*., 2007).
