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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

Nuclear DNA content of human islet cultures.DNA was quantified after isolation of nuclei of cultured islets. Islets were incubated for 1 and 7 days under control conditions or under low nutrient condition in combination with 20% or 1% of oxygen. Values are presented as median ± IQR (n = 4 separate batches of human islets). A p < 0.05 was considered statistical significant (***p < 0.001).
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f2: Nuclear DNA content of human islet cultures.DNA was quantified after isolation of nuclei of cultured islets. Islets were incubated for 1 and 7 days under control conditions or under low nutrient condition in combination with 20% or 1% of oxygen. Values are presented as median ± IQR (n = 4 separate batches of human islets). A p < 0.05 was considered statistical significant (***p < 0.001).

Mentions: To determine the loss of islet-cells as the consequence of the different culture conditions the nuclear DNA on day 1 and 7 was studied as a measure for surviving cells. Under normal control conditions and low-nutrient exposure in normoxic conditions an approximate reduction of 35.45 ± 1.97% and 35.43 ± 3.91% of the cells was observed. This reduction was 31.43 ± 5.43% under hypoxia but normal nutrient conditions and when islets were exposed to the combination hypoxia and low-nutrient conditions a reduction of 32.15 ± 5.27% was observed (Fig. 2). All the reductions in nuclear DNA were statistically significant (p < 0.001).


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)

Nuclear DNA content of human islet cultures.DNA was quantified after isolation of nuclei of cultured islets. Islets were incubated for 1 and 7 days under control conditions or under low nutrient condition in combination with 20% or 1% of oxygen. Values are presented as median ± IQR (n = 4 separate batches of human islets). A p < 0.05 was considered statistical significant (***p < 0.001).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f2: Nuclear DNA content of human islet cultures.DNA was quantified after isolation of nuclei of cultured islets. Islets were incubated for 1 and 7 days under control conditions or under low nutrient condition in combination with 20% or 1% of oxygen. Values are presented as median ± IQR (n = 4 separate batches of human islets). A p < 0.05 was considered statistical significant (***p < 0.001).
Mentions: To determine the loss of islet-cells as the consequence of the different culture conditions the nuclear DNA on day 1 and 7 was studied as a measure for surviving cells. Under normal control conditions and low-nutrient exposure in normoxic conditions an approximate reduction of 35.45 ± 1.97% and 35.43 ± 3.91% of the cells was observed. This reduction was 31.43 ± 5.43% under hypoxia but normal nutrient conditions and when islets were exposed to the combination hypoxia and low-nutrient conditions a reduction of 32.15 ± 5.27% was observed (Fig. 2). All the reductions in nuclear DNA were statistically significant (p < 0.001).

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