사이모신 베타 4와 VEGF의 발현을 여러 인간 조직에서 tissue microarray를 사용하여 조사하였다. 사이모신 베타 4는 간, 이자, 침샘의 관상피, 심장에서 강한 발현을 보였으며 피부, 폐, 이자, 림프절, 갑상선, 요관, 폐와 부신의 혈관 내피세포 등에서 중간 수준의 발현 양상을 보였다. VEGF의 발현 양상은 대체적으로 사이모신 베타 4와 동일하였으며 이자, 요관, 유선, 간, 식도, 신장, 폐, 부신 등의 혈관 내피세포에서 강하게 발현되었다. 이러한 결과를 통해 사이모신 베타 4는 간, 이자, 침샘의 관상피, 심장에서 중요한 역할을 담당하며 VEGF와 같은 발현 양상을 보여 혈관 신생작용에 관여함을 확인하였다.
Thymosin ${eta}4$, a small protein containing 43 amino acids, has multi-functional roles in cell physiology. It was first identified as a thymic maturation factor and recently has been shown to accelerate wound healing, hair growth, angiogenesis, tumor growth, and metastasis. It was also reported to play a key role in developing organs, including the nervous system and heart. Thymosin ${eta}4$ induces the expression of vascular endothelial cell growth factor (VEGF), laminin-5, and other important biologically active genes. Using tissue microarray analysis, we investigated the expression patterns of thymosin ${eta}4$ and VEGF in various normal human adult tissues. Thymosin ${eta}4$ was highly expressed in the liver, pancreas, ductal epithelium of the salivary gland, and heart, and moderately expressed in the skin, lung, spleen, lymph node, thymus, ureter, and blood endothelial cells in both the lung and adrenal gland. The expression of VEGF generally co-localized with thymosin ${eta}4$ and VEGF was highly expressed in the pancreas, ureter, mammary gland, liver, esophagus, and blood endothelial cells in both the lung and adrenal gland. These results suggest that thymosin ${eta}4$ plays an important role in the function of various organs and since the expression pattern of thymosin ${eta}4$ co-localized with VEGF, part of that function may be to induce or maintain angiogenesis.
