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Regeneration of the pancreas in adult zebrafish.

Moss JB, Koustubhan P, Greenman M, Parsons MJ, Walter I, Moss LG - Diabetes (2009)

Bottom Line: Dividing cells were primarily associated with affected islets and ducts but, with the exception of surgical partial pancreatectomy, were not extensively beta-cells.The ability of the zebrafish to regenerate a functional pancreas using chemical, genetic, and surgical approaches enabled us to identify patterns of cell proliferation in islets and ducts.Further study of the origin and contribution of proliferating cells in reestablishing islet function could provide strategies for treating human diseases.

View Article: PubMed Central - PubMed

Affiliation: Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, North Carolina, USA. jennifer.b.moss@duke.edu

ABSTRACT

Objective: Regenerating organs in diverse biological systems have provided clues to processes that can be harnessed to repair damaged tissue. Adult mammalian beta-cells have a limited capacity to regenerate, resulting in diabetes and lifelong reliance on insulin. Zebrafish have been used as a model for the regeneration of many organs. We demonstrate the regeneration of adult zebrafish pancreatic beta-cells. This nonmammalian model can be used to define pathways for islet-cell regeneration in humans.

Research design and methods: Adult transgenic zebrafish were injected with a single high dose of streptozotocin or metronidazole and anesthetized at 3, 7, or 14 days or pancreatectomized. Blood glucose measurements were determined and gut sections were analyzed using specific endocrine, exocrine, and duct cell markers as well as markers for dividing cells.

Results: Zebrafish recovered rapidly without the need for insulin injections, and normoglycemia was attained within 2 weeks. Although few proliferating cells were present in vehicles, ablation caused islet destruction and a striking increase of proliferating cells, some of which were Pdx1 positive. Dividing cells were primarily associated with affected islets and ducts but, with the exception of surgical partial pancreatectomy, were not extensively beta-cells.

Conclusions: The ability of the zebrafish to regenerate a functional pancreas using chemical, genetic, and surgical approaches enabled us to identify patterns of cell proliferation in islets and ducts. Further study of the origin and contribution of proliferating cells in reestablishing islet function could provide strategies for treating human diseases.

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Related in: MedlinePlus

Blood glucose levels return to normal after 2 weeks. Fasted blood glucose readings were recorded from cardiac blood in STZ-treated (black bars) versus vehicle-treated (white bars) zebrafish at 3, 7, and 14 days from 10 (5 male/5 female) STZ- and 6 (3 male/3 female) vehicle-injected InsGFP 1-year-old siblings. A two-fold reduction in blood glucose was observed 1 week after destruction of the β-cells. Gray bars: blood glucose readings from fasted InsNTR 1 year olds 3, 7, or 14 days after MET treatment. IP, intraperitoneal.
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Figure 2: Blood glucose levels return to normal after 2 weeks. Fasted blood glucose readings were recorded from cardiac blood in STZ-treated (black bars) versus vehicle-treated (white bars) zebrafish at 3, 7, and 14 days from 10 (5 male/5 female) STZ- and 6 (3 male/3 female) vehicle-injected InsGFP 1-year-old siblings. A two-fold reduction in blood glucose was observed 1 week after destruction of the β-cells. Gray bars: blood glucose readings from fasted InsNTR 1 year olds 3, 7, or 14 days after MET treatment. IP, intraperitoneal.

Mentions: To evaluate if the loss of fluorescent β-cells produced a physiological change, blood glucose levels in zebrafish at 3, 7 or 14 days after drug injection were measured (Fig. 2). The collected blood was rapidly discharged onto a strip containing adsorbed glucose oxidase, routinely used by human diabetic patients to monitor blood glucose (Freestyle). To acquire a baseline, fasted blood glucose readings were compared between male and female as well as wild-type versus transgenic animals. An average fasted adult zebrafish blood glucose reading was 57.4 mg/dl ± 4.1 mg/dl (n = 96). STZ-injected blood glucose levels increased at least two-fold after 3 days and returned to normal after 2 weeks without intervention (Fig. 2, black bars). Reports of STZ-induced rodent hyperglycemia have indicated a much larger increase of blood glucose readings after treatment. This may be due either to greater hydration secondary to hyperglycemia in zebrafish or to liver toxicity from drug administration (data not shown). In consideration of potential detrimental effects of STZ on tissues other than the pancreatic β-cells, we also evaluated a β-cell intrinsic ablation system in adult zebrafish (8). NTR converts the prodrug MET to a toxic compound that damages DNA in zebrafish embryos, causing β-cell apoptosis. Blood glucose readings for InsNTR-mCherry transgenics, recorded at time of death, also increased 3 days after injection and then fell to normal levels after 2 weeks. The observation that the 3 day MET blood glucose readings were higher than the STZ-treated reading at this time point suggests that β-cell ablation may have been more complete in the InsNTR transgenics.


Regeneration of the pancreas in adult zebrafish.

Moss JB, Koustubhan P, Greenman M, Parsons MJ, Walter I, Moss LG - Diabetes (2009)

Blood glucose levels return to normal after 2 weeks. Fasted blood glucose readings were recorded from cardiac blood in STZ-treated (black bars) versus vehicle-treated (white bars) zebrafish at 3, 7, and 14 days from 10 (5 male/5 female) STZ- and 6 (3 male/3 female) vehicle-injected InsGFP 1-year-old siblings. A two-fold reduction in blood glucose was observed 1 week after destruction of the β-cells. Gray bars: blood glucose readings from fasted InsNTR 1 year olds 3, 7, or 14 days after MET treatment. IP, intraperitoneal.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2712797&req=5

Figure 2: Blood glucose levels return to normal after 2 weeks. Fasted blood glucose readings were recorded from cardiac blood in STZ-treated (black bars) versus vehicle-treated (white bars) zebrafish at 3, 7, and 14 days from 10 (5 male/5 female) STZ- and 6 (3 male/3 female) vehicle-injected InsGFP 1-year-old siblings. A two-fold reduction in blood glucose was observed 1 week after destruction of the β-cells. Gray bars: blood glucose readings from fasted InsNTR 1 year olds 3, 7, or 14 days after MET treatment. IP, intraperitoneal.
Mentions: To evaluate if the loss of fluorescent β-cells produced a physiological change, blood glucose levels in zebrafish at 3, 7 or 14 days after drug injection were measured (Fig. 2). The collected blood was rapidly discharged onto a strip containing adsorbed glucose oxidase, routinely used by human diabetic patients to monitor blood glucose (Freestyle). To acquire a baseline, fasted blood glucose readings were compared between male and female as well as wild-type versus transgenic animals. An average fasted adult zebrafish blood glucose reading was 57.4 mg/dl ± 4.1 mg/dl (n = 96). STZ-injected blood glucose levels increased at least two-fold after 3 days and returned to normal after 2 weeks without intervention (Fig. 2, black bars). Reports of STZ-induced rodent hyperglycemia have indicated a much larger increase of blood glucose readings after treatment. This may be due either to greater hydration secondary to hyperglycemia in zebrafish or to liver toxicity from drug administration (data not shown). In consideration of potential detrimental effects of STZ on tissues other than the pancreatic β-cells, we also evaluated a β-cell intrinsic ablation system in adult zebrafish (8). NTR converts the prodrug MET to a toxic compound that damages DNA in zebrafish embryos, causing β-cell apoptosis. Blood glucose readings for InsNTR-mCherry transgenics, recorded at time of death, also increased 3 days after injection and then fell to normal levels after 2 weeks. The observation that the 3 day MET blood glucose readings were higher than the STZ-treated reading at this time point suggests that β-cell ablation may have been more complete in the InsNTR transgenics.

Bottom Line: Dividing cells were primarily associated with affected islets and ducts but, with the exception of surgical partial pancreatectomy, were not extensively beta-cells.The ability of the zebrafish to regenerate a functional pancreas using chemical, genetic, and surgical approaches enabled us to identify patterns of cell proliferation in islets and ducts.Further study of the origin and contribution of proliferating cells in reestablishing islet function could provide strategies for treating human diseases.

View Article: PubMed Central - PubMed

Affiliation: Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, North Carolina, USA. jennifer.b.moss@duke.edu

ABSTRACT

Objective: Regenerating organs in diverse biological systems have provided clues to processes that can be harnessed to repair damaged tissue. Adult mammalian beta-cells have a limited capacity to regenerate, resulting in diabetes and lifelong reliance on insulin. Zebrafish have been used as a model for the regeneration of many organs. We demonstrate the regeneration of adult zebrafish pancreatic beta-cells. This nonmammalian model can be used to define pathways for islet-cell regeneration in humans.

Research design and methods: Adult transgenic zebrafish were injected with a single high dose of streptozotocin or metronidazole and anesthetized at 3, 7, or 14 days or pancreatectomized. Blood glucose measurements were determined and gut sections were analyzed using specific endocrine, exocrine, and duct cell markers as well as markers for dividing cells.

Results: Zebrafish recovered rapidly without the need for insulin injections, and normoglycemia was attained within 2 weeks. Although few proliferating cells were present in vehicles, ablation caused islet destruction and a striking increase of proliferating cells, some of which were Pdx1 positive. Dividing cells were primarily associated with affected islets and ducts but, with the exception of surgical partial pancreatectomy, were not extensively beta-cells.

Conclusions: The ability of the zebrafish to regenerate a functional pancreas using chemical, genetic, and surgical approaches enabled us to identify patterns of cell proliferation in islets and ducts. Further study of the origin and contribution of proliferating cells in reestablishing islet function could provide strategies for treating human diseases.

Show MeSH
Related in: MedlinePlus