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DAMP production by human islets under low oxygen and nutrients in the presence or absence of an immunoisolating-capsule and necrostatin-1.

Paredes-Juarez GA, Sahasrabudhe NM, Tjoelker RS, de Haan BJ, Engelse MA, de Koning EJ, Faas MM, de Vos P - Sci Rep (2015)

Bottom Line: Immunoisolation in immunoprotective membranes reduced DAMP release and immune activation via retention of the relative large DAMPs in the capsules.Another effective strategy was suppressing necroptosis using the inhibitor nec-1.DAMP release can be reduced in vitro by immunoisolation or intervention with nec-1.

View Article: PubMed Central - PubMed

Affiliation: University of Groningen, University Medical Center Groningen, Department of Pathology and Medical Biology, Section of Immunoendocrinology, Groningen, 9713 GZ, The Netherlands.

ABSTRACT
In between the period of transplantation and revascularization, pancreatic islets are exposed to low-oxygen and low-nutrient conditions. In the present study we mimicked those conditions in vitro to study the involvement of different cell death processes, release of danger-associated molecular patterns (DAMP), and associated in vitro immune activation. Under low-oxygen and low-nutrient conditions, apoptosis, autophagy and necroptosis occur in human islets. Necroptosis is responsible for DAMP-release such as dsDNA, uric acid, and HMGB1. The sensors of the innate immune system able to recognize these DAMPs are mainly TLR, NOD receptors, and C-type lectins. By using cell-lines with a non-functional adaptor molecule MyD88, we were able to show that the islet-derived DAMPs signal mainly via TLR. Immunoisolation in immunoprotective membranes reduced DAMP release and immune activation via retention of the relative large DAMPs in the capsules. Another effective strategy was suppressing necroptosis using the inhibitor nec-1. Although the effect on cell-survival was minor, nec-1 was able to reduce the release of HMGB1 and its associated immune activation. Our data demonstrate that in the immediate post-transplant period islets release DAMPs that in vitro enhance responses of innate immune cells. DAMP release can be reduced in vitro by immunoisolation or intervention with nec-1.

No MeSH data available.


Related in: MedlinePlus

Danger-associated molecular patterns (DAMPs) released by free human islets.Human islets were incubated for 1 (a,c,e) or 7 (b,d,f) days under control and low nutrient conditions at 20% and 1% of oxygen. DAMPs produced by islets were high mobility group protein B1 (HMGB1; (a,b)), double stranded DNA (dsDNA; (c,d)), and uric acid (e,f). Values are presented as median ± IQR (n = 4 separate batches of human islets). A p < 0.05 was considered statistically significant (**p < 0.01).
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f4: Danger-associated molecular patterns (DAMPs) released by free human islets.Human islets were incubated for 1 (a,c,e) or 7 (b,d,f) days under control and low nutrient conditions at 20% and 1% of oxygen. DAMPs produced by islets were high mobility group protein B1 (HMGB1; (a,b)), double stranded DNA (dsDNA; (c,d)), and uric acid (e,f). Values are presented as median ± IQR (n = 4 separate batches of human islets). A p < 0.05 was considered statistically significant (**p < 0.01).

Mentions: Release of DAMPs is a mean for quantification of the involvement of necrosis and necroptosis182223. The most commonly studied DAMPs in necrosis or necroptosis are heat shock protein 70 (HSP70), double stranded DNA (dsDNA), uric acid, and high mobility group box 1 (HMGB1)192122. In none of the conditions tested we observed HSP70 release. This was different with HMGB1, uric acid, and dsDNA. These DAMPs were constitutively present in culture media even under control conditions. HMGB1 release was found under all culture conditions without any significant difference between different culture conditions (Fig. 4a,b). This release is possibly due to loss in cell-viability.


DAMP production by human islets under low oxygen and nutrients in the presence or absence of an immunoisolating-capsule and necrostatin-1.

Paredes-Juarez GA, Sahasrabudhe NM, Tjoelker RS, de Haan BJ, Engelse MA, de Koning EJ, Faas MM, de Vos P - Sci Rep (2015)

Danger-associated molecular patterns (DAMPs) released by free human islets.Human islets were incubated for 1 (a,c,e) or 7 (b,d,f) days under control and low nutrient conditions at 20% and 1% of oxygen. DAMPs produced by islets were high mobility group protein B1 (HMGB1; (a,b)), double stranded DNA (dsDNA; (c,d)), and uric acid (e,f). Values are presented as median ± IQR (n = 4 separate batches of human islets). A p < 0.05 was considered statistically significant (**p < 0.01).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4588515&req=5

f4: Danger-associated molecular patterns (DAMPs) released by free human islets.Human islets were incubated for 1 (a,c,e) or 7 (b,d,f) days under control and low nutrient conditions at 20% and 1% of oxygen. DAMPs produced by islets were high mobility group protein B1 (HMGB1; (a,b)), double stranded DNA (dsDNA; (c,d)), and uric acid (e,f). Values are presented as median ± IQR (n = 4 separate batches of human islets). A p < 0.05 was considered statistically significant (**p < 0.01).
Mentions: Release of DAMPs is a mean for quantification of the involvement of necrosis and necroptosis182223. The most commonly studied DAMPs in necrosis or necroptosis are heat shock protein 70 (HSP70), double stranded DNA (dsDNA), uric acid, and high mobility group box 1 (HMGB1)192122. In none of the conditions tested we observed HSP70 release. This was different with HMGB1, uric acid, and dsDNA. These DAMPs were constitutively present in culture media even under control conditions. HMGB1 release was found under all culture conditions without any significant difference between different culture conditions (Fig. 4a,b). This release is possibly due to loss in cell-viability.

Bottom Line: Immunoisolation in immunoprotective membranes reduced DAMP release and immune activation via retention of the relative large DAMPs in the capsules.Another effective strategy was suppressing necroptosis using the inhibitor nec-1.DAMP release can be reduced in vitro by immunoisolation or intervention with nec-1.

View Article: PubMed Central - PubMed

Affiliation: University of Groningen, University Medical Center Groningen, Department of Pathology and Medical Biology, Section of Immunoendocrinology, Groningen, 9713 GZ, The Netherlands.

ABSTRACT
In between the period of transplantation and revascularization, pancreatic islets are exposed to low-oxygen and low-nutrient conditions. In the present study we mimicked those conditions in vitro to study the involvement of different cell death processes, release of danger-associated molecular patterns (DAMP), and associated in vitro immune activation. Under low-oxygen and low-nutrient conditions, apoptosis, autophagy and necroptosis occur in human islets. Necroptosis is responsible for DAMP-release such as dsDNA, uric acid, and HMGB1. The sensors of the innate immune system able to recognize these DAMPs are mainly TLR, NOD receptors, and C-type lectins. By using cell-lines with a non-functional adaptor molecule MyD88, we were able to show that the islet-derived DAMPs signal mainly via TLR. Immunoisolation in immunoprotective membranes reduced DAMP release and immune activation via retention of the relative large DAMPs in the capsules. Another effective strategy was suppressing necroptosis using the inhibitor nec-1. Although the effect on cell-survival was minor, nec-1 was able to reduce the release of HMGB1 and its associated immune activation. Our data demonstrate that in the immediate post-transplant period islets release DAMPs that in vitro enhance responses of innate immune cells. DAMP release can be reduced in vitro by immunoisolation or intervention with nec-1.

No MeSH data available.


Related in: MedlinePlus