Zinc effect on human lymphatic malformation cells in vitro

HIF-1α contributes to tube malformation of human lymphatic endothelial cells by upregulating VEGFR-3

Hypoxia-inducible factor-1α (HIF-1α) is upregulated in various tumors and associated with lymphangiogenesis and angiogenesis during tumor development and metastasis. However, the role of HIF-1α in cystic lymphatic malformations (cLM) remains unclear. In the present study, expression of HIF-1α and vascular endothelial growth factor receptor 3 (VEGFR-3) was evaluated in 20 pairs of cLM specimens from patients who accepted curative surgery at Children’s Hospital of Nanjing Medical University (Nanjing, China). Additionally, a stable HIF-1α-overexpressing human lymphatic endothelial cell (HLEC) line was established. Overexpression and silencing of HIF-1α were used to investigate the biological role in colony formation, migration and lymphatic tube formation. HIF-1α and VEGFR-3 were upregulated in cLM specimens compared with adjacent normal tissues. In addition, HIF-1α effectively induced HLEC colony formation and migration. Furthermore, lymphatic malformation of HLECs was promoted in vitro by overexpression of HIF-1α. HIF-1α overexpression upregulated VEGFR-3 during lymphangiogenesis. Additionally, expression of lymphatic endothelial markers prospero homeobox protein 1 and lymphatic vessel endothelial hyaluronan receptor 1 increased significantly during lymphatic tube malformation. The presented data demonstrated that HIF-1α overexpression in HLECs promoted colony formation, migration and tube malformation via upregulation of VEGFR-3. These findings may assist in the development of HIF-1α-targeted cLM therapeutics in the future.

Assessment of the Biocompatibility and Biological Effects of Biodegradable Pure Zinc Material in the Colorectum

Little attention has been paid to the biocompatibility and biological effects of zinc as a material. Here, we therefore investigated the biocompatibility and anti-inflammatory and collagen-promoting effects of pure zinc material in the colorectum. Our in vitro results indicated that zinc toxicity and concentration were closely related. Low concentrations of zinc ions and pure zinc material extract had only minor effects on the viability of primary rectal mucosal epithelial cells; however, cytotoxicity was observed at concentrations greater than 0.017 μg/μL and 60%, respectively. In vivo experiments demonstrated that zinc pins degraded slowly in the colorectum (their volume decreasing by approximately 7.79% over 1 month) and did not cause serious adverse reactions. Pure zinc material was found to inhibit acute inflammation through increased expression of ENA-78 and F4/80. Moreover, zinc material heightened expression of collagen and VEGF, factors conducive to wound healing, in surrounding colorectal tissues. These preliminary results suggest that zinc shows great promise as an implant material for medical applications involving colorectal surgery.