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Activated pancreatic stellate cells can impair pancreatic islet function in mice.

Zang G, Sandberg M, Carlsson PO, Welsh N, Jansson L, Barbu A - Ups. J. Med. Sci. (2015)

Bottom Line: Furthermore, we measured their cytokine production and determined their effects on insulin release from simultaneously cultured islets.In islet transplants they were found mainly in the graft periphery.Increased islet cell caspase-3 activation and a decreased islet cell replication were consistently observed after co-culture for 2 or 7 days.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Cell Biology, Uppsala University , Uppsala , Sweden.

ABSTRACT

Background: Pancreatic or islet fibrosis is often associated with activated pancreatic stellate cells (PSCs). PSCs are considered not only to promote fibrosis, but also to be associated with glucose intolerance in some diseases. We therefore evaluated morphological and functional relationships between islets and PSCs in the normal mouse pancreas and transplanted islets.

Methods: Immunohistochemistry was used to map the presence of PSCs in the normal mouse pancreas and islets implanted under the renal capsule. We isolated and cultured mouse PSCs and characterized them morphologically by immunofluorescence staining. Furthermore, we measured their cytokine production and determined their effects on insulin release from simultaneously cultured islets.

Results: PSCs were scattered throughout the pancreas, with occasional cells within the islets, particularly in the islet capsule. In islet transplants they were found mainly in the graft periphery. Cultured PSCs became functionally activated and produced several cytokines. Throughout the culture period they linearly increased their production of interleukin-6 and mammalian keratinocyte-derived chemokine. PSC cytokine production was not affected by acute hyperglycemia. Syngeneic islets co-cultured with PSCs for 24-48 h increased their insulin release and lowered their insulin content. However, short-term insulin release in batch-type incubations was unaffected after 48 h of co-culture. Increased islet cell caspase-3 activation and a decreased islet cell replication were consistently observed after co-culture for 2 or 7 days.

Conclusion: Activated PSCs may contribute to impaired islet endocrine function seen in exocrine pancreatitis and in islet fibrosis associated with some cases of type 2 diabetes.

No MeSH data available.


Related in: MedlinePlus

Mouse islet insulin release after co-culture with mouse pancreatic stellate cells. A: Insulin release into the medium at different time points after co-culture of isolated mouse islets and mouse pancreatic stellate cells. B: Islet insulin content in isolated mouse pancreatic islets after 48 h of co-culture with mouse pancreatic stellate cells. C: Insulin release from isolated mouse islets cultured alone or with either 5% (vol/vol) medium conditioned by 24 h of culture with mouse stellate cells. D: Insulin release into the medium, presented as fraction of total insulin content, from isolated mouse pancreatic islets co-cultured with isolated mouse pancreatic stellate cells. A total of 40 islets and 105 pancreatic stellate cells were present in each culture dish. During the release experiments islets were incubated in KRBH 1 h each at 1.7 and 16.7 mM glucose. Insulin concentrations were measured with either Meso Scale immunoelectrodetection (A, B) or ELISA (C, D). Values are means ± SEM for 4–9 experiments. * P < 0.05 compared with islets alone.
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Figure 3: Mouse islet insulin release after co-culture with mouse pancreatic stellate cells. A: Insulin release into the medium at different time points after co-culture of isolated mouse islets and mouse pancreatic stellate cells. B: Islet insulin content in isolated mouse pancreatic islets after 48 h of co-culture with mouse pancreatic stellate cells. C: Insulin release from isolated mouse islets cultured alone or with either 5% (vol/vol) medium conditioned by 24 h of culture with mouse stellate cells. D: Insulin release into the medium, presented as fraction of total insulin content, from isolated mouse pancreatic islets co-cultured with isolated mouse pancreatic stellate cells. A total of 40 islets and 105 pancreatic stellate cells were present in each culture dish. During the release experiments islets were incubated in KRBH 1 h each at 1.7 and 16.7 mM glucose. Insulin concentrations were measured with either Meso Scale immunoelectrodetection (A, B) or ELISA (C, D). Values are means ± SEM for 4–9 experiments. * P < 0.05 compared with islets alone.

Mentions: When culturing stellate cells and islets together for 2 days there were no adverse morphological effects on either cell type. There was a marked increase in medium insulin concentration after co-culture periods between 24 h and 48 h when compared with culture of the same number of islets alone (Figure 3A). PSCs cultured alone as expected released no insulin (Figure 3A). Medium insulin accumulation was unaffected when freshly isolated islets were exposed to PSCs for 12 h (Figure 3A). On the other hand, islet insulin content was decreased after 48 h of co-culture with PSCs (Figure 3B). Additional experiments were performed after 48 h of co-culture, when glucose-stimulated insulin release was measured in a batch-type incubation system. PSCs did not significantly affect insulin release in these experiments (data not shown). However, when we considered insulin secretion as percentage of the intracellular insulin content, we found a higher glucose-induced insulin release as well as elevated basal insulin secretion, although the latter did not attain statistical significance (P = 0.067) (Figure 3D). When islets were cultured in medium preconditioned with PSCs for 24 h there was an increase in insulin release to the culture medium similar to that seen when co-cultured with PSCs (Figure 3C). However, islet insulin content remained unchanged (data not shown).


Activated pancreatic stellate cells can impair pancreatic islet function in mice.

Zang G, Sandberg M, Carlsson PO, Welsh N, Jansson L, Barbu A - Ups. J. Med. Sci. (2015)

Mouse islet insulin release after co-culture with mouse pancreatic stellate cells. A: Insulin release into the medium at different time points after co-culture of isolated mouse islets and mouse pancreatic stellate cells. B: Islet insulin content in isolated mouse pancreatic islets after 48 h of co-culture with mouse pancreatic stellate cells. C: Insulin release from isolated mouse islets cultured alone or with either 5% (vol/vol) medium conditioned by 24 h of culture with mouse stellate cells. D: Insulin release into the medium, presented as fraction of total insulin content, from isolated mouse pancreatic islets co-cultured with isolated mouse pancreatic stellate cells. A total of 40 islets and 105 pancreatic stellate cells were present in each culture dish. During the release experiments islets were incubated in KRBH 1 h each at 1.7 and 16.7 mM glucose. Insulin concentrations were measured with either Meso Scale immunoelectrodetection (A, B) or ELISA (C, D). Values are means ± SEM for 4–9 experiments. * P < 0.05 compared with islets alone.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4526872&req=5

Figure 3: Mouse islet insulin release after co-culture with mouse pancreatic stellate cells. A: Insulin release into the medium at different time points after co-culture of isolated mouse islets and mouse pancreatic stellate cells. B: Islet insulin content in isolated mouse pancreatic islets after 48 h of co-culture with mouse pancreatic stellate cells. C: Insulin release from isolated mouse islets cultured alone or with either 5% (vol/vol) medium conditioned by 24 h of culture with mouse stellate cells. D: Insulin release into the medium, presented as fraction of total insulin content, from isolated mouse pancreatic islets co-cultured with isolated mouse pancreatic stellate cells. A total of 40 islets and 105 pancreatic stellate cells were present in each culture dish. During the release experiments islets were incubated in KRBH 1 h each at 1.7 and 16.7 mM glucose. Insulin concentrations were measured with either Meso Scale immunoelectrodetection (A, B) or ELISA (C, D). Values are means ± SEM for 4–9 experiments. * P < 0.05 compared with islets alone.
Mentions: When culturing stellate cells and islets together for 2 days there were no adverse morphological effects on either cell type. There was a marked increase in medium insulin concentration after co-culture periods between 24 h and 48 h when compared with culture of the same number of islets alone (Figure 3A). PSCs cultured alone as expected released no insulin (Figure 3A). Medium insulin accumulation was unaffected when freshly isolated islets were exposed to PSCs for 12 h (Figure 3A). On the other hand, islet insulin content was decreased after 48 h of co-culture with PSCs (Figure 3B). Additional experiments were performed after 48 h of co-culture, when glucose-stimulated insulin release was measured in a batch-type incubation system. PSCs did not significantly affect insulin release in these experiments (data not shown). However, when we considered insulin secretion as percentage of the intracellular insulin content, we found a higher glucose-induced insulin release as well as elevated basal insulin secretion, although the latter did not attain statistical significance (P = 0.067) (Figure 3D). When islets were cultured in medium preconditioned with PSCs for 24 h there was an increase in insulin release to the culture medium similar to that seen when co-cultured with PSCs (Figure 3C). However, islet insulin content remained unchanged (data not shown).

Bottom Line: Furthermore, we measured their cytokine production and determined their effects on insulin release from simultaneously cultured islets.In islet transplants they were found mainly in the graft periphery.Increased islet cell caspase-3 activation and a decreased islet cell replication were consistently observed after co-culture for 2 or 7 days.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Cell Biology, Uppsala University , Uppsala , Sweden.

ABSTRACT

Background: Pancreatic or islet fibrosis is often associated with activated pancreatic stellate cells (PSCs). PSCs are considered not only to promote fibrosis, but also to be associated with glucose intolerance in some diseases. We therefore evaluated morphological and functional relationships between islets and PSCs in the normal mouse pancreas and transplanted islets.

Methods: Immunohistochemistry was used to map the presence of PSCs in the normal mouse pancreas and islets implanted under the renal capsule. We isolated and cultured mouse PSCs and characterized them morphologically by immunofluorescence staining. Furthermore, we measured their cytokine production and determined their effects on insulin release from simultaneously cultured islets.

Results: PSCs were scattered throughout the pancreas, with occasional cells within the islets, particularly in the islet capsule. In islet transplants they were found mainly in the graft periphery. Cultured PSCs became functionally activated and produced several cytokines. Throughout the culture period they linearly increased their production of interleukin-6 and mammalian keratinocyte-derived chemokine. PSC cytokine production was not affected by acute hyperglycemia. Syngeneic islets co-cultured with PSCs for 24-48 h increased their insulin release and lowered their insulin content. However, short-term insulin release in batch-type incubations was unaffected after 48 h of co-culture. Increased islet cell caspase-3 activation and a decreased islet cell replication were consistently observed after co-culture for 2 or 7 days.

Conclusion: Activated PSCs may contribute to impaired islet endocrine function seen in exocrine pancreatitis and in islet fibrosis associated with some cases of type 2 diabetes.

No MeSH data available.


Related in: MedlinePlus