Originally published as JHC exPRESS on September 17, 2007. doi:10.1369/jhc.7A7278.2007
Volume 56 (1): 33-44, 2008 Copyright ©The Histochemical Society, Inc. Pancreatic Endocrine and Exocrine Cell Ontogeny From Renal Capsule–transplanted Embryonic Stem Cells in Streptozocin-injured Mice
Section for Studies on Metastasis, National Cancer Center Research Institute, Tokyo, Japan (MK,FT,TO,GQ), and Central Laboratory, Effector Cell Institute, Tokyo, Japan (SK,GQ) Correspondence to: Gary Quinn, PhD, Section for Studies on Metastasis, National Cancer Center Research Institute, 1-1 Tsukiji, 5-chome, Chuo-ku, Tokyo 104-0045, Japan. E-mail: garyquinn99{at}hotmail.com
In this study, we describe pancreatic cell ontogeny in renal capsule–transplanted embryonic stem cells (ES) after injury by streptozocin (STZ), showing pancreatogenesis in situ. Seven-week-old female BALB/c nude mice were treated with either a single 175- or 200-mg/kg STZ dose, a regimen that induces substantial β-cell damage without overt hyperglycemia, and transplanted 24 hr later with 1 x 105 ES. Immunohistochemistry was performed on ES tissue at 15, 21, and 28 days after transplantation using antibodies against stage- and lineage-specific pancreatic markers. After 21 days, PDX-1+ pancreatic foci first appeared in the renal capsule and expressed both amylase and endocrine hormones (insulin, glucagon, and somatostatin). These foci increased in size by day 28 because of acinar and duct cell proliferation, whereas endocrine cells remained non-dividing, and made up 2–4% of ES tumor volume. PDX-1, Nkx6.1, Ngn3, and ISL-1 protein localization patterns in pancreatic foci were comparable with embryonic pancreatogenesis. A prevalence of multihormonal endocrine cells, a characteristic of adult β-cell regeneration, indicated a possible divergence from embryonic islet cell development. The results indicate that β-cell damage, without overt hyperglycemia, induces a process of fetal-like pancreatogenesis in renal capsule–transplanted ES, leading to β-cell neogenesis. (J Histochem Cytochem 56:33–44, 2008)
Key Words: regeneration embryonic stem cells pancreatic β cells pancreatogenesis differentiation diabetes pancreas hormone
DEVELOPMENT OF the exocrine and endocrine pancreas in utero has been well mapped using lineage and stage-specific markers (Edlund 2002
Adult pancreas regeneration on the other hand is less well characterized, partly because of the variety of models studied and their resultant neogenic responses (Lehv and Fitzgerald 1968
Streptozocin (STZ) specifically and directly kills β cells within 24 hr by necrosis (Chang and Diani 1985 In this study, we show that, after STZ injury without concomitant overt hyperglycemia, both exocrine and endocrine pancreas cell neogenesis occurs in a subset of transplanted embryonic stem cells (ES) residing at the transplantation site (the renal capsule). Thus, a regenerative response seems to be captured in naive pluripotent stem cells at a remote site that recapitulates major aspects of normal embryonic pancreatogenesis.
Animals and STZ Treatment Animal experiments were performed in compliance with the guidelines of the Institute for Laboratory Animal Research at the National Cancer Center Research Institute. Female BALB/c nude mice (CLEA; Tokyo, Japan), 7 weeks of age, were used for all experiments. Blood glucose measurements were performed on whole venous blood collected from the tail vein using the Freestyle Flash Blood Monitoring System (Nipro; Tokyo, Japan) according to the manufacturer's instructions. For induction of β-cell damage by STZ (Sigma Aldrich; St. Louis, MO), mice received a single 300 µl IP injection of STZ within 15 min of dissolution in freshly prepared 20 mM cold citrate buffer (pH 4.5) at either 175 or 200 mg/kg body weight. Non–STZ-treated mice received 300 µl citrate buffer alone. For renal capsule transplantation, 1 x 105 ES were pipetted beneath the left renal capsule 24 hr after STZ treatment. Briefly, mice were anesthetized by exposure to 1–3% isoflurane, and a 1.5-cm cut through the skin and muscle of the left flank dorsal to the spleen was made. The wound was washed with 1 ml PBS containing penicillin/streptomycin (Invitrogen; Carlsbad, CA), and the kidney was externalized. A small lateral cut was made in the kidney membrane using a scalpel, and 2 µl of cell suspension, or PBS alone for sham transplantation, was dispensed beneath the film. The kidney was replaced in the abdominal cavity, and the incision was closed using surgical wound clips. Intraperitoneal glucose tolerance testing (IPGTT) was performed as described by the Animal Models of Diabetes Complications Consortium (www.amdcc.org). Mice were fasted for 7 hr before IP injection with 2 mg/kg glucose solution (Sigma-Aldrich). IPGTT was performed on day 15 after STZ treatment.
Culturing and In Vivo Transplantation of ES
Immunofluorescence and Immunohistochemical Analyses
Analysis of Apoptosis
Statistical Analysis
Pancreatic Foci Are Induced After β-Cell Damage by STZ In a preliminary study, we found that a single administration of 175, 200, 225, or 240 mg/kg STZ to female BALB/c nude mice 7–8 weeks of age (n=20 each dose) resulted in 0%, 10%, 90%, or 100% hyperglycemia, respectively. The BALB/c genetic background displays unusually high resistance to STZ-induced DNA damage, which is directly related to poly (ADP-ribose) polymerase (PARP) activation and NAD depletion (Cardinal et al. 1999 15 days; data not shown). β-cell damage by STZ was assessed by IPGTT at day 15 after STZ administration, where citrate buffer was given to control mice. Impaired glucose tolerance was detected in both sham-transplanted (n=10) and ES-transplanted (n=15) groups, with both groups treated with STZ, whereas ES-transplanted mice treated with citrate buffer alone (n=5) maintained normal glucose tolerance (Figure 1
). Definitive pancreatic foci, comprising both endocrine (PDX-1+/hormone+) and exocrine (amylase+) cells, were identified in ES tumors at days 21 and 28 but not at day 15 (Figures 2
and 3)
. Almost invariably, these foci occurred proximal to the kidney cortex (Figure 2), and each ES tumor analyzed from STZ-treated animals at both day 21 and day 28 contained multiple pancreatic foci comprising 1–2% and 2–4%, respectively, of the total ES tumor volume (Table 1
). Importantly, pancreatic foci were not detected in ES tumors from mice without β-cell damage (citrate buffer treated; Figures 2 and 3; Table 1).
Each pancreatic focus characteristically contained a single or multiple luminal epithelial ducts from which lobulated acinar-like structures emerged. Scattered within and around the acinar cells were small isolated clusters of hormone-positive cells (Figure 3). Day 28 foci were 5–20 times larger overall than those at day 21, resulting from acinar and ductal, but not endocrine, cell expansion (determined by Ki67 expression; Figure 3J). Although small clusters of two to six endocrine cells were found at both day 21 and day 28, at day 21, the endocrine cells were grouped around the edges of acini, but by day 28, they became scattered throughout the exocrine parenchyma. The endocrine cell ratio was 10% of the acinar cell number at day 21 but decreased to 1% by day 28, apparently as a result of acinar cell proliferation. There was no evidence of apoptotic β cells (0/33) at either day 21 or day 28.
Early Development of Pancreatic Foci
Endocrine Cell Development in Pancreatic Foci Hormone coexpression was predominant in endocrine cells of ES-derived pancreatic foci. In more developed foci, PDX-1 was downregulated in the majority of the acinar-like cells, after which both insulin and glucagon protein were detectable. Surprisingly, coexpression of glucagon and insulin was dominant, with these multihormonal cells also expressing the islet cell markers PDX-1, Nkx6.1, and ISL-1 (Figure 6 ). Although foci were larger at day 28 than at day 21 (Figures 2 and 3), coexpression of insulin and glucagon persisted in the majority of endocrine cells at day 28, despite the obvious increase in foci size. As for day 21 foci, hormone coexpression at day 28 was accompanied by expression of PDX-1, Nkx6.1, and ISL-1 (Figure 7 ). The ISL-1+ cells were more numerous than Nkx6.1+ cells at day 21 (Figure 6), whereas at day 28, the number of ISL-1+ and Nkx6.1+ cells were equivalent (Figure 7). In the embryonic pancreas during normal mouse development, a similar pattern of ISL-1/Nkx6.1 expression as at day 21 and day 28 was seen at e11.5 and e14.5, respectively (Figure 8 ).
Multiple Hormone-expressing Cells Somatostatin and insulin expression was detected simultaneously in day 21 foci, and there was minor overlap of expression of both proteins (Figure 9 ); weak expression of somatostatin was detectable in insulin+ cells but not vice versa (Figures 9A–9C). At day 28, this overlap was more apparent because the overall number of endocrine cells, although scattered, was increased, and the majority of insulin+ cells coexpressed somatostatin (Figures 9D–9F). Somatostatin expression levels, however, were lower in these multihormone-expressing cells than in somatostatin mono-positive cells (Figures 9D–9F, arrows). Surprisingly glucagon, somatostatin, and insulin triple hormone coexpression was common among the endocrine cells at day 28 (Figure 10 ). As for all of the endocrine cells identified, these multihormonal cells were non-dividing (Ki67–; Figure 10A). Although multihormonal endocrine cells were predominant at day 28, hormone mono-positive insulin+/PDX-1+ cells and glucagon+/PDX-1– cells were also detected in the same foci (Figure 10), suggesting that some terminal endocrine cell differentiation occurred by day 28.
Cell Proliferation and Expression of the Pro-endocrine Gene Ngn3 Ki67 staining of pancreatic foci at day 21 showed that endocrine cells were non-dividing (data not shown). At day 28, endocrine cells remained non-dividing, whereas many of the acinar, duct, and other hormone cells were Ki67+ (Figures 3 and 10). Ngn3 is the earliest pro-endocrine cell lineage marker expressed in the embryonic pancreas (Jensen et al. 2000b
Embryonic pancreatogenesis is complex, requiring signaling from non-endodermal (Kim et al. 1997
In an earlier study, we found that IP-transplanted ES homed to the pancreas and produced exocrine and endocrine cells locally (Takeshita et al. 2006
In the mouse pancreas, after early expression throughout the pancreas anlagen, there is a dramatic decrease in the relative number of PDX-1–expressing cells between e10.5 and e11, remaining low until after e13.5, when it begins to increase again (Ohlsson et al. 1993
In the developing mouse pancreas, the basic helix-loop-helix transcription factor Ngn3 is expressed transiently during the secondary transition and marks the earliest pro-endocrine fated cells detectable; this transcription factor is essential for islet cell development, although it is downregulated before any islet hormone expression is detectable (Gradwohl et al. 2000
During pancreas development, the homeodomain transcription factor Nkx6.1 is coexpressed with PDX-1 from e9.5 in most pancreatic bud epithelial cells (Pedersen et al. 2005
Early debate over a possible multihormonal ontogeny of islet endocrine cells (Alpert et al. 1988 and β cells develop from precursors with non-overlapping hormone expression. However, in the adult pancreas, transitional cells have been identified that are absent or rare during embryonic development. Somatostatin+/PDX-1+ and somatostatin+/insulin+/PDX-1+ transitional cell numbers increased in euglycemic STZ-injured pancreatic islets (with negligible β-cell neogenesis from the pancreatic ducts) (Fernandes et al. 1997 transgenic adult mice induced multihormonal (insulin+/glucagon+, insulin+/somatostatin+, insulin+/PP+), ductal/exocrine (carbonic anhydrase II+/amylase+), and exocrine/endocrine (amylase+/insulin+) intermediate cells (Gu et al. 1994
The renal capsule is known to support the maturation and survival of fetal islet-like cell clusters (Beattie et al. 1994 In conclusion, we identified embryonic-like pancreatogenesis leading to insulin-producing cells in renal capsule–transplanted ES after β cell–specific injury. The data suggest that an inductive environment exists in the renal capsule that seems to be dependent on systemic regenerative stimuli elicited on β-cell destruction. It will be important to examine the effect of elevated blood glucose on endocrine differentiation in this system. Additionally, further studies will be necessary to establish whether other cell types, for example, partially differentiated ES, can undergo pancreatogenesis without teratoma formation, and whether their insulin-producing cell progeny can improve glucose homeostasis in vivo.
We thank N. Namatame, Y. Yamamoto, and A. Inoue (Section for Studies on Metastasis, NCCRI) for technical assistance, Professor H. Edlund (University of Umea, Umea, Sweden) for the gift of anti-ISL-1 antiserum, and Dr. P. Serup (Hagedorn Institute, Denmark) for the gift of anti-Nkx6.1 antibody. The anti-Ngn3 monoclonal antibody developed by Professor O. D. Madsen was obtained from the Developmental Studies Hybridoma Bank developed under the auspices of the NICHD and maintained by The University of Iowa, Department of Biological Sciences, Iowa City, IA. This work was supported in part by a Grant-in-Aid for the Third-Term Comprehensive 10-Year Strategy for Cancer Control; Health Science Research Grants for Research on the Human Genome and Gene Therapy from the Ministry of Health, Labor, and Welfare of Japan.
Received for publication May 15, 2007; accepted August 31, 2007
Alpert S, Hanahan D, Teitelman G (1988) Hybrid insulin genes reveal a developmental lineage for pancreatic endocrine cells and imply a relationship with neurons. Cell 53:295–308[CrossRef][Medline] Apelqvist A, Li H, Sommer L, Beatus P, Anderson DJ, Honjo T, Hrabe de Angelis M, et al. (1999) Notch signalling controls pancreatic cell differentiation. Nature 400:877–881[CrossRef][Medline] Beattie GM, Butler C, Hayek A (1994) Morphology and function of cultured human fetal pancreatic cells transplanted into athymic mice: a longitudinal study. Cell Transplant 3:421–425[Medline] Bonner-Weir S, Trent DF, Zmachinski CJ, Clore ET, Weir GC (1981) Limited B cell regeneration in a B cell deficient rat model: studies with dexamethasone. Metabolism 30:914–918[CrossRef][Medline] Brolen GK, Heins N, Edsbagge J, Semb H (2005) Signals from the embryonic mouse pancreas induce differentiation of human embryonic stem cells into insulin-producing β-cell-like cells. Diabetes 54:2867–2874 Cardinal JW, Allan DJ, Cameron DP (1999) Poly(ADP-ribose)polymerase activation determines strain sensitivity to streptozotocin-induced β cell death in inbred mice. J Mol Endocrinol 22:65–70[Abstract] Chang A, Diani AR (1985) Chemically and hormonally induced diabetes mellitus. In Volk B, Arquilla ER, eds. The Diabetic Pancreas. New York, Plenum, 415–438 Dor Y, Brown J, Martinez OI, Melton DA (2004) Adult pancreatic β-cells are formed by self-duplication rather than stem-cell differentiation. Nature 429:41–46[CrossRef][Medline] Edlund H (2002) Pancreatic organogenesis–developmental mechanisms and implications for therapy. Nat Rev Genet 3:524–532[CrossRef][Medline] Fernandes A, King LC, Guz Y, Stein R, Wright CV, Teitelman G (1997) Differentiation of new insulin-producing cells is induced by injury in adult pancreatic islets. Endocrinology 138:1750–1762 Gradwohl G, Dierich A, LeMeur M, Guillemot F (2000) neurogenin3 is required for the development of the four endocrine cell lineages of the pancreas. Proc Natl Acad Sci USA 97:1607–1611 Gu D, Lee MS, Krahl T, Sarvetnick N (1994) Transitional cells in the regenerating pancreas. Development 120:1873–1881[Abstract] Gu D, Sarvetnick N (1993) Epithelial cell proliferation and islet neogenesis in IFN-g transgenic mice. Development 118:33–46[Abstract] Gu G, Dubauskaite J, Melton DA (2002) Direct evidence for the pancreatic lineage: NGN3+ cells are islet progenitors and are distinct from duct progenitors. Development 129:2447–2457[Medline] Guz Y, Nasir I, Teitelman G (2001) Regeneration of pancreatic β cells from intra-islet precursor cells in an experimental model of diabetes. Endocrinology 142:4956–4968 Henseleit KD, Nelson SB, Kuhlbrodt K, Hennings JC, Ericson J, Sander M (2005) NKX6 transcription factor activity is required for Herrera PL (2000) Adult insulin- and glucagon-producing cells differentiate from two independent cell lineages. Development 127:2317–2322[Abstract] Herrera PL, Huarte J, Sanvito F, Meda P, Orci L, Vassalli JD (1991) Embryogenesis of the murine endocrine pancreas; early expression of pancreatic polypeptide gene. Development 113:1257–1265[Abstract] Jensen J, Heller RS, Funder-Nielsen T, Pedersen EE, Lindsell C, Weinmaster G, Madsen OD, et al. (2000a) Independent development of pancreatic Jensen J, Pedersen EE, Galante P, Hald J, Heller RS, Ishibashi M, Kageyama R, et al. (2000b) Control of endodermal endocrine development by Hes-1. Nat Genet 24:36–44[CrossRef][Medline] Jensen JN, Cameron E, Garay MV, Starkey TW, Gianani R, Jensen J (2005) Recapitulation of elements of embryonic development in adult mouse pancreatic regeneration. Gastroenterology 128:728–741[CrossRef][Medline] Kahan BW, Jacobson LM, Hullett DA, Ochoada JM, Oberley TD, Lang KM, Odorico JS (2003) Pancreatic precursors and differentiated islet cell types from murine embryonic stem cells: an in vitro model to study islet differentiation. Diabetes 52:2016–2024 Kim SK, Hebrok M, Melton DA (1997) Notochord to endoderm signaling is required for pancreas development. Development 124:4243–4252[Abstract] Lehv M, Fitzgerald PJ (1968) Pancreatic acinar cell regeneration. IV. Regeneration after resection. Am J Pathol 53:513–535[Medline] Like AA, Rossini AA (1976) Streptozotocin-induced pancreatic insulitis: new model of diabetes mellitus. Science 193:415–417 Lipsett M, Finegood DT (2002) β-cell neogenesis during prolonged hyperglycemia in rats. Diabetes 51:1834–1841 Micallef SJ, Janes ME, Knezevic K, Davis RP, Elefanty AG, Stanley EG (2005) Retinoic acid induces Pdx1-positive endoderm in differentiating mouse embryonic stem cells. Diabetes 54:301–305[CrossRef][Medline] Michalopoulos GK, DeFrances MC (1997) Liver regeneration. Science 276:60–66 Movassat J, Beattie GM, Lopez AD, Hayek A (2002) Exendin 4 up-regulates expression of PDX 1 and hastens differentiation and maturation of human fetal pancreatic cells. J Clin Endocrinol Metab 87:4775–4781 Movassat J, Beattie GM, Lopez AD, Portha B, Hayek A (2003) Keratinocyte growth factor and β-cell differentiation in human fetal pancreatic endocrine precursor cells. Diabetologia 46:822–829[CrossRef][Medline] Ohlsson H, Karlsson K, Edlund T (1993) IPF1, a homeodomain-containing transactivator of the insulin gene. EMBO J 12:4251–4259[Medline] Oster A, Jensen J, Serup P, Galante P, Madsen OD, Larsson LI (1998) Rat endocrine pancreatic development in relation to two homeobox gene products (Pdx-1 and Nkx 6.1). J Histochem Cytochem 46:707–715 Pedersen JK, Nelson SB, Jorgensen MC, Henseleit KD, Fujitani Y, Wright CV, Sander M, et al. (2005) Endodermal expression of Nkx6 genes depends differentially on Pdx1. Dev Biol 288:487–501[CrossRef][Medline] Pictet R, Rutter WJ (1972) Development of the embryonic pancreas. In Steiner DF, Steiner FN, eds. Handbook of Physiology. Washington, DC, American Physiological Society, 25–66 Rose MI, Crisera CA, Colen KL, Connelly PR, Longaker MT, Gittes GK (1999) Epithelio-mesenchymal interactions in the developing mouse pancreas: morphogenesis of the adult architecture. J Pediatr Surg 34:774–779[CrossRef][Medline] Rosenberg L, Brown RA, Duguid WP (1983) A new approach to the induction of duct epithelial hyperplasia and nesidioblastosis by cellophane wrapping of the hamster pancreas. J Surg Res 35:63–72[CrossRef][Medline] Sander M, Sussel L, Conners J, Scheel D, Kalamaras J, Dela Cruz F, Schwitzgebel V, et al. (2000) Homeobox gene Nkx6.1 lies downstream of Nkx2.2 in the major pathway of β-cell formation in the pancreas. Development 127:5533–5540[Abstract] Schwitzgebel VM, Scheel DW, Conners JR, Kalamaras J, Lee JE, Anderson DJ, Sussel L, et al. (2000) Expression of neurogenin3 reveals an islet cell precursor population in the pancreas. Development 127:3533–3542[Abstract] Slack JM (1995) Developmental biology of the pancreas. Development 121:1569–1580[Abstract] Stanger BZ, Tanaka AJ, Melton DA (2007) Organ size is limited by the number of embryonic progenitor cells in the pancreas but not the liver. Nature 445:886–891[CrossRef][Medline] Takeshita F, Kodama M, Yamamoto H, Ikarashi Y, Ueda S, Teratani T, Yamamoto Y, et al. (2006) Streptozotocin-induced partial β cell depletion in nude mice without hyperglycaemia induces pancreatic morphogenesis in transplanted embryonic stem cells. Diabetologia 49:2948–2958[CrossRef][Medline] Trucco M (2005) Regeneration of the pancreatic β cell. J Clin Invest 115:5–12[CrossRef][Medline] Yamamoto H, Quinn G, Asari A, Yamanokuchi H, Teratani T, Terada M, Ochiya T (2003) Differentiation of embryonic stem cells into hepatocytes: biological functions and therapeutic application. Hepatology 37:983–993[CrossRef][Medline]
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