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Scientific article
English

Regulated laminin-332 expression in human islets of Langerhans

Contributors

Armanet, Mathieu Pierre Jean; Wojtusciszyn, Anne; Morel, Philippe; Parnaud, Géraldine; Rousselle, Patricia; Sinigaglia, Corinne; Berney, Thierry; Bosco, Domenico

Published in

The FASEB journal, vol. 23, no. 12, p. 4046-4055

Publication date

2009

Abstract

Laminin-332 (LN-332) is a basement membrane component known to exert a beneficial effect on rat pancreatic beta cells in vitro. In this work, we analyzed the expression of LN-332 in human islets, its expression after inflammatory insults by cytokines, and the molecular mechanisms responsible for this effect. By Western blotting and RT-PCR, we showed that LN-332 was expressed in isolated human islets. By immunofluorescence on pancreas sections, we observed that labeling was confined to endocrine cells in islets. Confocal microscopy analysis on isolated islet cells revealed that labeling was granular but did not colocalize with hormone secretory granules. LN-332 was most abundant in cultured islets compared to freshly isolated islets and was found in culture medium, which suggests that it was secreted by islets. When islets were exposed to interleukin (IL)-1beta, expression and secretion of LN-332 increased as compared to control. No effect was observed with tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma. LY294002, an inhibitor of phosphatidylinositol 3-kinase (PI3-K) activity, inhibited culture- and IL-1beta-induced LN-332 expression in islets. These results show that LN-332, known to have some beneficial effect on beta cells in vitro, is produced and secreted by endocrine islet cells and is up-regulated by stressing conditions such as culture and IL-1beta-exposure.

UNIGE affiliation entities

UNIGE research groups

Citation (ISO format)

ARMANET, Mathieu Pierre Jean et al. Regulated laminin-332 expression in human islets of Langerhans. In: The FASEB journal, 2009, vol. 23, n° 12, p. 4046–4055. doi: 10.1096/fj.08-127142

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Article (Published version)

Identifiers

Additional URL for this publication

http://www.fasebj.org/cgi/content/full/23/12/4046

Journal ISSN

0892-6638
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Technical informations

Creation

09/12/2009 17:30:00

First validation

09/12/2009 17:30:00

Update

14/03/2023 15:19:35

Status update

14/03/2023 15:19:35

Last indexation

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