A new polysaccharide isolated from Dendrobium offcinale, stimulates aquaporin-3 expression in human keratinocytes

AbstractExposure to arsenic, a ubiquitous metalloid on Earth, results in human cancers. Skin cancer is the most common arsenical cancers. Both autophagy and aquaporin pathway are known to promote carcinogenesis. However, the mechanisms by which arsenic regulates aquaporin and autophagy in arsenical skin cancers remain elusive. This study aims to address how arsenic regulates aquaporin-3, the predominant aquaporin in epidermal keratinocytes, and how this process would induce autophagy. Quantitative real-time PCR and immunofluorescence were used to measure the expression of aquaporin 3 in arsenical skin cancers and arsenic-treated keratinocytes. Beclin-1 expression and autophagy were measured. We examined if blocking aquaporin 3 could interfere arsenic-induced autophagy in keratinocytes. Expression of aquaporin 3 is increased in arsenical cancers and in arsenic-treated keratinocytes. Arsenic induced autophagy in primary human keratinocytes. Notably, the arsenic-induced autophagy was inhibited by pretreatment of keratinocytes with aquaporin inhibitors Auphen or AgNO3, or RNA interference against aquaporin 3. The data indicates that the aquaporin 3 is an important cell membrane channel to mediate arsenic uptake and contributes to the arsenic-induced autophagy.

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Osmotic stress up-regulates aquaporin-3 gene expression in cultured human keratinocytes

Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression ◽

10.1016/s0167-4781(01)00320-7 ◽

2001 ◽

Vol 1522 (2) ◽

pp. 82-88 ◽

Cited By ~ 74

Author(s):

Yoshinori Sugiyama ◽

Yukiko Ota ◽

Mariko Hara ◽

Shintaro Inoue

Keyword(s):

Gene Expression ◽

Osmotic Stress ◽

Human Keratinocytes ◽

Aquaporin 3

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Kalinin: A new epithelial basement membrane adhesion molecule

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100085198 ◽

1991 ◽

Vol 49 ◽

pp. 178-179

Author(s):

Douglas R. Keene ◽

Gregory P. Lunstrum ◽

Patricia Rousselle ◽

Robert E. Burgeson

Keyword(s):

Basement Membrane ◽

Culture Media ◽

Polyacrylamide Gel Electrophoresis ◽

Human Keratinocytes ◽

Positive Staining ◽

Human Amnion ◽

Epithelial Basement Membrane ◽

Type Vii Collagen ◽

Keratinocyte Cell ◽

Epithelial Basement

A mouse monoclonal antibody produced from collagenase digests of human amnion was used by LM and TEM to study the distribution and ultrastructural features of an antigen present in epithelial tissues and in cultured human keratinocytes, and by immunoaffinity chromatography to partially purify the antigen from keratinocyte cell culture media.By immunofluorescence microscopy, the antigen displays a tissue distribution similar to type VII collagen; positive staining of the epithelial basement membrane is seen in skin, oral mucosa, trachea, esophagus, cornea, amnion and lung. Images from rotary shadowed preparations isolated by affinity chromatography demonstrate a population of rod-like molecules 107 nm in length, having pronounced globular domains at each end. Polyacrylamide gel electrophoresis suggests that the size of this molecule is approximately 440kDa, and that it is composed of three nonidentical chains disulfide bonded together.

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