The ectopic expression of Pax4 in the mouse pancreas converts progenitor cells into alpha and subsequently beta cells.

We have previously reported that the loss of Arx and/or Pax4 gene activity leads to a shift in the fate of the different endocrine cell subtypes in the mouse pancreas, without affecting the total endocrine cell numbers. Here, we conditionally and ectopically express Pax4 using different cell-specific promoters and demonstrate that Pax4 forces endocrine precursor cells, as well as mature alpha cells, to adopt a beta cell destiny. This results in a glucagon deficiency that provokes a compensatory and continuous glucagon+ cell neogenesis requiring the re-expression of the proendocrine gene Ngn3. However, the newly formed alpha cells fail to correct the hypoglucagonemia since they subsequently acquire a beta cell phenotype upon Pax4 ectopic expression. Notably, this cycle of neogenesis and redifferentiation caused by ectopic expression of Pax4 in alpha cells is capable of restoring a functional beta cell mass and curing diabetes in animals that have been chemically depleted of beta cells.

Ptf1a-mediated control of Dll1 reveals an alternative to the lateral inhibition mechanism.

Neurog3-induced Dll1 expression in pancreatic endocrine progenitors ostensibly activates Hes1 expression via Notch and thereby represses Neurog3 and endocrine differentiation in neighboring cells by lateral inhibition. Here we show in mouse that Dll1 and Hes1 expression deviate during regionalization of early endoderm, and later during early pancreas morphogenesis. At that time, Ptf1a activates Dll1 in multipotent pancreatic progenitor cells (MPCs), and Hes1 expression becomes Dll1 dependent over a brief time window. Moreover, Dll1, Hes1 and Dll1/Hes1 mutant phenotypes diverge during organ regionalization, become congruent at early bud stages, and then diverge again at late bud stages. Persistent pancreatic hypoplasia in Dll1 mutants after eliminating Neurog3 expression and endocrine development, together with reduced proliferation of MPCs in both Dll1 and Hes1 mutants, reveals that the hypoplasia is caused by a growth defect rather than by progenitor depletion. Unexpectedly, we find that Hes1 is required to sustain Ptf1a expression, and in turn Dll1 expression in early MPCs. Our results show that Ptf1a-induced Dll1 expression stimulates MPC proliferation and pancreatic growth by maintaining Hes1 expression and Ptf1a protein levels.

An illustrated review of early pancreas development in the mouse.

Pancreas morphogenesis and cell differentiation are highly conserved among vertebrates during fetal development. The pancreas develops through simple budlike structures on the primitive gut tube to a highly branched organ containing many specialized cell types. This review presents an overview of key molecular components and important signaling sources illustrated by an extensive three-dimensional (3D) imaging of the developing mouse pancreas at single cell resolution. The 3D documentation covers the time window between embryonic days 8.5 and 14.5 in which all the pancreatic cell types become specified and therefore includes gene expression patterns of pancreatic endocrine hormones, exocrine gene products, and essential transcription factors. The 3D perspective provides valuable insight into how a complex organ like the pancreas is formed and a perception of ventral and dorsal pancreatic growth that is otherwise difficult to uncover. We further discuss how this global analysis of the developing pancreas confirms and extends previous studies, and we envisage that this type of analysis can be instrumental for evaluating mutant phenotypes in the future.

Specificity of four monoclonal anti-NKx6-1 antibodies.

The homeodomain transcription factor Nkx6-1 is essential for proper motor neuron development and development of insulin-producing pancreatic beta-cells. Nkx6-1 is closely related to Nkx6-2 and Nkx6-3, and all three are expressed in the developing central nervous system and in the developing foregut. Immunohistochemical detection of protein expression is an important tool for description of the temporal differences in expression patterns. When several gene family members like the Nkx6 factors have overlapping or juxtaposed expression domains, there is an elevated risk of unrecognized cross-reactivity, and it is therefore crucial to determine the specificities of antibodies against such targets. In this study we have determined the epitope consensus sequences of four monoclonal antibodies against Nkx6-1 using SPOT membranes, and we refined the results by combined peptide recognition and blocking assays. We show that two of the monoclonal anti-Nkx6-1 antibodies specifically recognize Nkx6-1 and do not cross-react to Nkx6-2 and Nkx6-3. The other two monoclonal anti-Nkx6-1 antibodies are specific to Nkx6-1 in mice but do not recognize Nkx6-1 in chicken and human.

Generation and characterization of Ptf1a antiserum and localization of Ptf1a in relation to Nkx6.1 and Pdx1 during the earliest stages of mouse pancreas development.

Ptf1a and Pdx1 are critical transcription factors of early pancreatic development, as shown by loss of function studies where lack of each gene alone causes almost complete pancreas agenesis. Ptf1a is particularly interesting because it is linked to a recently reported signature gene expression profile associated with the multipotent condition. Few useful antibody reagents have been available for consistent and reliable immunohistochemical visualization of Ptf1a protein expression in the early developing pancreas in which the level of production of this critical regulator seems to be very low. We describe a novel rabbit antibody raised against the c-terminal portion of the mouse Ptf1a protein and report immunodetection, for the first time, as early as embryonic day (e) 8.5-e8.75 in the dorsal and ventral buds of the mouse pancreas as well as in the neural tube at e10.0. Detailed confocal analysis identifies an abundant triple-positive (Ptf1a(+)/Nkx6.1(+)/Pdx1(+)) putative early multipotent pancreatic progenitor cell that marks the e9.5 dorsal pancreas and e10.5 ventral pancreas. Furthermore, expression patterns of Nkx6.1 vs Ptf1a subsequently segregate during branching morphogenesis (trunk vs tip), ending up marking two distinct cell populations of progenitors at e12.5. From e15.5 (mouse) and in adult pancreas (mouse, rat, and human), the Ptf1a antibody marks only acinar cell nuclei, as expected for its subsequent role in committing/maintaining cells in this differentiated state. In summary, this antibody is a novel tool to further characterize important early steps of pancreas differentiation. This manuscript contains online supplemental material at http://www.jhc.org. Please visit this article online to view these materials.

The morphology of islets of Langerhans is only mildly affected by the lack of Pdx-1 in the pancreas of adult Meriones jirds.

The Meriones Jirds belong to the genus of Gerbillinae (Rodentia: Muridae). We and others have previously reported the lack of the pancreatic beta-cell transcription factor, Pdx-1 in the fat sand rat, Psammomys obesus. The aim of the study was to investigate the expression and localization of Pdx-1 in phylogenetically related members of the Gerbillinae subfamily. In addition, we characterized by IHC the expression pattern of islet hormones and additional important pancreatic transcription factors in order to evaluate overall endocrine pancreas appearance. PCR showed that Pdx-1 was easily amplified from a wide range of phylogenetically distant species but not from 13 different gerbilline species. Identical to P. obesus the important beta-cell transcription factor Pdx-1 was absent from all five jirds. However, expression of other critical islet transcription factors and islet hormones was generally normal. Insulin was localized in the center of the islets with glucagon, somatostatin and pancreatic polypeptide (PP) found in the islet mantle. PYY cells were also observed and colocalized with PP cells. The NKX family of transcription factors were localized to the same cell types as seen in other rodents. MafA was nuclear localized in some of the insulin immunoreactive but not in other cell types, while MafB was found not only in the glucagon cells but also in many of the insulin cells. In conclusion, Pdx-1 appears to be lacking in all gerbils and despite the lack of Pdx-1, the Meriones Jirds have islets that are morphologically similar to other rodents and express hormones and transcription factors in the expected pattern except for MafA and MafB.

The EndoC-ßH1 cell line is a valid model of human beta cells and applicable for screenings to identify novel drug target candidates.

OBJECTIVE: To characterize the EndoC-ßH1 cell line as a model for human beta cells and evaluate its beta cell functionality, focusing on insulin secretion, proliferation, apoptosis and ER stress, with the objective to assess its potential as a screening platform for identification of novel anti-diabetic drug candidates. METHODS: EndoC-ßH1 was transplanted into mice for validation of in vivo functionality. Insulin secretion was evaluated in cells cultured as monolayer and as pseudoislets, as well as in diabetic mice. Cytokine induced apoptosis, glucolipotoxicity, and ER stress responses were assessed. Beta cell relevant mRNA and protein expression were investigated by qPCR and antibody staining. Hundreds of proteins or peptides were tested for their effect on insulin secretion and proliferation. RESULTS: Transplantation of EndoC-ßH1 cells restored normoglycemia in streptozotocin induced diabetic mice. Both in vitro and in vivo, we observed a clear insulin response to glucose, and, in vitro, we found a significant increase in insulin secretion from EndoC-ßH1 pseudoislets compared to monolayer cultures for both glucose and incretins. Apoptosis and ER stress were inducible in the cells and caspase 3/7 activity was elevated in response to cytokines, but not affected by the saturated fatty acid palmitate. By screening of various proteins and peptides, we found Bombesin (BB) receptor agonists and Pituitary Adenylate Cyclase-Activating Polypeptides (PACAP) to significantly induce insulin secretion and the proteins SerpinA6, STC1, and APOH to significantly stimulate proliferation. ER stress was readily induced by Tunicamycin and resulted in a reduction of insulin mRNA. Somatostatin (SST) was found to be expressed by 1% of the cells and manipulation of the SST receptors was found to significantly affect insulin secretion. CONCLUSIONS: Overall, the EndoC-ßH1 cells strongly resemble human islet beta cells in terms of glucose and incretin stimulated insulin secretion capabilities. The cell line has an active cytokine induced caspase 3/7 apoptotic pathway and is responsive to ER stress initiation factors. The cells' ability to proliferate can be further increased by already known compounds as well as by novel peptides and proteins. Based on its robust performance during the functionality assessment assays, the EndoC-ßH1 cell line was successfully used as a screening platform for identification of novel anti-diabetic drug candidates.

An improved method for three-dimensional reconstruction of protein expression patterns in intact mouse and chicken embryos and organs.

We have developed a wholemount immunofluorescence protocol for the simultaneous detection of up to three proteins in mouse and chicken embryos. Combined with Murray's clearing reagent (BABB) and microscope objectives with long working ranges and high numerical apertures mounted on a confocal microscope, cellular resolution can be obtained in depths offering the possibility of examining expression patterns in entire organs or embryos. Three-dimensional projections of the optical confocal sections can be computed with computer software allowing rotation around any axis. The protocol is robust and we find that most antibodies working on tissue sections also work with this protocol. This manuscript contains online supplemental material at http://www.jhc.org. Please visit this article online to view these materials.

Pancreas phylogeny and ontogeny in relation to a 'pancreatic stem cell'.

Blood glucose regulation has likely evolved during early vertebrate evolution to allow and secure the concurrent evolution of complex brains and nervous systems: an inner milieu of constant blood glucose levels through millions of years has provided an extra degree of freedom for the brain to evolve without having to think of getting energy supply. Key regulators of blood glucose, insulin, and glucagon are produced by the dominating cell types of the pancreatic islet of Langerhans: the insulin producing beta cells and the glucagon producing alpha cells. Interestingly, it appears that the beta cell pioneered the formation or the foundation of the pancreatic organ according to current phylogenetic insights. Such phylogenetic aspects of a pancreatic stem cell are at the end discussed in relation to directed differentiation of embryonic stem cells/ES cells towards therapeutic beta cells.

Association between neuromedin U gene variants and overweight and obesity.

BACKGROUND: Neuromedin U (NMU) is an anorexic neuropeptide expressed in the hypothalamus. Mice lacking the NmU gene are hyperphagic and obese, whereas mice overexpressing Nmu are hypophagic and lean. OBJECTIVE: Our objective was to investigate whether variants in NMU are associated with human obesity. DESIGN: The coding region of NMU was analyzed for variants in obese Czech children and obese Danish adults. Identified missense variants were investigated for cosegregation with obesity in families or association with obesity in the general population. SETTING: The study was performed at Steno Diabetes Center, Denmark, and Department of Pediatrics, Charles University, Czech Republic. SUBJECTS AND METHODS: A total of 289 Czech children and adolescents with early-onset obesity and 84 Danish obese adults were analyzed for variants in NMU. A NMU Ala19Glu polymorphism was genotyped in 5851 Danish subjects of the Inter99 cohort, and a rare NMU Arg165Trp mutation was sequenced in the proband family and in 53 lean and unrelated Czech subjects. RESULTS: The rare NMU Arg165Trp variant cosegregated with childhood obesity in a Czech family. Homozygous carriers of the Glu allele of the NMU Ala19Glu polymorphism were more common in the overweight and obese subjects; the Glu/Glu frequency was 0.4 (95% confidence interval, 0.2-0.6) among 2586 lean subjects (BMI < 25 kg/m2) and 0.9 (95% confidence interval, 0.7-1.1) among 3265 overweight and obese subjects (body mass index >or= 25 kg/m2) [odds ratio, 2.5 (1.2-5.3); P = 0.01]. CONCLUSION: Amino acid variants in NMU associate with overweight and obesity, suggesting that NMU is involved in energy regulation in humans.

Evidence of an association between the Arg72 allele of the peptide YY and increased risk of type 2 diabetes.

We tested the hypothesis that variants in the gene encoding the prepropeptide YY (PYY) associate with type 2 diabetes and/or obesity. Mutation analyses of DNA from 84 patients with obesity and familial type 2 diabetes identified two polymorphisms, IVS3 + 68C>T and Arg72Thr, and one rare variant, +151C>A of PYY. The common allele of the Arg72Thr variant associated with type 2 diabetes with an allele frequency of the Arg allele of 0.667 (95% CI 0.658-0.677) among 4,639 glucose-tolerant subjects and 0.692 (0.674-0.710) among 1,326 patients with type 2 diabetes (P = 0.005, odds ratio 1.19 [95% CI 1.05-1.35]). The same polymorphism associated with overweight (25 < or = BMI < 30 kg/m2) (P = 0.018, 1.15 [1.02-1.28]). In quantitative trait analyses of a population-based sample of 6,022 subjects, the Arg allele was associated with an increased plasma glucose level 2 h after an oral glucose tolerance test (OGTT) (P = 0.03), an increased area under the curve for the post-OGTT plasma glucose level (P = 0.03), and a lower insulinogenic index (P = 0.01). In conclusion, the common Arg allele of the PYY Arg72Thr variant modestly associates with type 2 diabetes and with type 2 diabetes-related quantitative traits.

Generation and characterization of monoclonal antibodies against the transcription factor Nkx6.1.

We present the generation of a panel of monoclonal antibodies (F55A10, F55A12, F64A6B4, and F65A2) against the homeodomain transcription factor Nkx6.1, one of the essential transcription factors that regulates the multistep differentiation process of precursor cells into endocrine beta-cells in the pancreas. Expression of Nkx6.1 can be detected in developing pancreatic epithelium and in adult insulin-producing beta-cells, making this transcription factor a unique beta-cell marker. For production of monoclonal antibodies, RBF mice were immunized with a GST-Nkx6.1 fusion protein containing a 66-amino acid C-terminal fragment of rat Nkx6.1. Four clones were established as stable hybridoma cell lines and the produced antibodies were of the mouse IgG1/kappa subtype. When applied for immunohistochemistry on frozen sections of adult mouse pancreas, monoclonal antibodies stain specifically the beta-cells in the endocrine islets of Langerhans with patterns comparable to that of a previously produced polyclonal rabbit serum. Monoclonal antibodies can be divided into two groups that appear to recognize different epitopes, as determined by competition ELISA. The presented antibodies are useful tools for the further characterization of the role and function of Nkx6.1 in pancreatic development, especially for use in double-labeling experiments with existing polyclonal rabbit antibodies.

Xenotropic retrovirus Bxv1 in human pancreatic ß cell lines.

It has been reported that endogenous retroviruses can contaminate human cell lines that have been passaged as xenotransplants in immunocompromised mice. We previously developed and described 2 human pancreatic ß cell lines (EndoC-ßH1 and EndoC-ßH2) that were generated in this way. Here, we have shown that B10 xenotropic virus 1 (Bxv1), a xenotropic endogenous murine leukemia virus (MuLV), is present in these 2 recently described cell lines. We determined that Bxv1 was also present in SCID mice that were used for in vivo propagation of EndoC-ßH1/2 cells, suggesting that contamination occurred during xenotransplantation. EndoC-ßH1/2 cells released Bxv1 particles that propagated to human 293T and Mus dunni cells. Mobilization assays demonstrated that Bxv1 transcomplements defective MuLV-based retrovectors. In contrast, common rodent ß cell lines, rat INS-1E and RIN-5F cells and mouse MIN6 and ßTC3 cells, displayed either no or extremely weak xenotropic helper activity toward MuLV-based retrovectors, although xenotropic retrovirus sequences and transcripts were detected in both mouse cell lines. Bxv1 propagation from EndoC-ßH1/2 to 293T cells occurred only under optimized conditions and was overall poorly efficient. Thus, although our data imply that MuLV-based retrovectors should be cautiously used in EndoC-ßH1/2 cells, our results indicate that an involuntary propagation of Bxv1 from these cells can be easily avoided with good laboratory practices.

Research Resource: A Dual Proteomic Approach Identifies Regulated Islet Proteins During ß-Cell Mass Expansion In Vivo.

Diabetes is characterized by insulin insufficiency due to a relative paucity of functional ß-cell mass. Thus, strategies for increasing ß-cell mass in situ are sought-after for therapeutic purposes. Pregnancy is a physiological state capable of inducing robust ß-cell mass expansion, however, the mechanisms driving this expansion are not fully understood. Thus, the aim of this study was to characterize pregnancy-induced changes in the islet proteome at the peak of ß-cell proliferation in mice. Islets from pregnant and nonpregnant littermates were compared via 2 proteomic strategies. In vivo pulsed stable isotope labeling of amino acids in cell culture was used to monitor de novo protein synthesis during the first 14.5 days of pregnancy. In parallel, protein abundance was determined using ex vivo dimethyl labelling at gestational day 14.5. Comparison of the 2 datasets revealed 170 islet proteins to be up regulated as a response to pregnancy. These included several proteins, not previously associated with pregnancy-induced islet expansion, such as CLIC1, STMN1, MCM6, PPIB, NEDD4, and HLTF. Confirming the validity of our approach, we also identified proteins encoded by genes known to be associated with pregnancy-induced islet expansion, such as CHGB, IGFBP5, MATN2, EHHADH, IVD, and BMP1. Bioinformatic analyses demonstrated enrichment and activation of the biological functions: "protein synthesis" and "proliferation," and predicted the transcription factors HNF4α, MYC, MYCN, E2F1, NFE2L2, and HNF1α as upstream regulators of the observed expressional changes. As the first characterization of the islet-proteome during pregnancy, this study provides novel insight into the mechanisms involved in promoting pregnancy-induced ß-cell mass expansion and function.

Pancreatic α-cell hyperplasia and hyperglucagonemia due to a glucagon receptor splice mutation.

Glucagon stimulates hepatic glucose production by activating specific glucagon receptors in the liver, which in turn increase hepatic glycogenolysis as well as gluconeogenesis and ureagenesis from amino acids. Conversely, glucagon secretion is regulated by concentrations of glucose and amino acids. Disruption of glucagon signaling in rodents results in grossly elevated circulating glucagon levels but no hypoglycemia. Here, we describe a patient carrying a homozygous G to A substitution in the invariant AG dinucleotide found in a 3' mRNA splice junction of the glucagon receptor gene. Loss of the splice site acceptor consensus sequence results in the deletion of 70 nucleotides encoded by exon 9, which introduces a frame shift and an early termination signal in the receptor mRNA sequence. The mutated receptor neither bound 125I-labeled glucagon nor induced cAMP production upon stimulation with up to 1 µM glucagon. Despite the mutation, the only obvious pathophysiological trait was hyperglucagonemia, hyperaminoacidemia and massive hyperplasia of the pancreatic α-cells assessed by histology. Our case supports the notion of a hepato-pancreatic feedback system, which upon disruption leads to hyperglucagonemia and α-cell hyperplasia, as well as elevated plasma amino acid levels. Together with the glucagon-induced hypoaminoacidemia in glucagonoma patients, our case supports recent suggestions that amino acids may provide the feedback link between the liver and the pancreatic α-cells. LEARNING POINTS: Loss of function of the glucagon receptor may not necessarily lead to the dysregulation of glucose homeostasis.Loss of function of the glucagon receptor causes hyperaminoacidemia, hyperglucagonemia and α-cell hyperplasia and sometimes other pancreatic abnormalities.A hepato-pancreatic feedback regulation of the α-cells, possibly involving amino acids, may exist in humans.

Autocrine Action of IGF2 Regulates Adult ß-Cell Mass and Function.

Insulin-like growth factor 2 (IGF2), produced and secreted by adult ß-cells, functions as an autocrine activator of the ß-cell insulin-like growth factor 1 receptor signaling pathway. Whether this autocrine activity of IGF2 plays a physiological role in ß-cell and whole-body physiology is not known. Here, we studied mice with ß-cell-specific inactivation of Igf2 (ßIGF2KO mice) and assessed ß-cell mass and function in aging, pregnancy, and acute induction of insulin resistance. We showed that glucose-stimulated insulin secretion (GSIS) was markedly reduced in old female ßIGF2KO mice; glucose tolerance was, however, normal because of increased insulin sensitivity. While on a high-fat diet, both male and female ßIGF2KO mice displayed lower GSIS compared with control mice, but reduced ß-cell mass was observed only in female ßIGF2KO mice. During pregnancy, there was no increase in ß-cell proliferation and mass in ßIGF2KO mice. Finally, ß-cell mass expansion in response to acute induction of insulin resistance was lower in ßIGF2KO mice than in control mice. Thus, the autocrine action of IGF2 regulates adult ß-cell mass and function to preserve in vivo GSIS in aging and to adapt ß-cell mass in response to metabolic stress, pregnancy hormones, and acute induction of insulin resistance.

Nestin is expressed in vascular endothelial cells in the adult human pancreas.

In this study we examined the expression of nestin in islets, the exocrine part, and the big ducts of the adult human pancreas by immunofluorescent double staining. Two different anti-nestin antisera in combination with various pancreatic and endothelial markers were employed. Nestin-immunoreactive cells were found in islets and in the exocrine portion. All nestin-positive cells co-expressed the vascular endothelial markers PECAM-1 (CD31), endoglin (CD105), and CD34 as well as vimentin. Endocrine, acinar, and duct cells did not stain for nestin. We also demonstrated that in the area of big pancreatic ducts, nestin-positive cells represent small capillaries scattered in the connective tissue surrounding the duct epithelium and do not reside between the duct cells. We detected nestin-expressing endothelial cells located adjacent to the duct epithelium where endocrine differentiation occurs. We have shown that nestin is expressed by vascular endothelial cells in human pancreas, and therefore it is unlikely that nestin specifically marks a subpopulation of cells representing endocrine progenitors in the adult pancreas.

Expression of Wnt, Frizzled, sFRP, and DKK genes in adult human pancreas.

Wnts are important signaling molecules involved in many normal developmental processes in the human body as well as some forms of cancer. Nineteen Wnt genes are found in the human genome, as well as 10 Wnt receptor genes called Frizzled. Two coreceptors called LRP 5 and 6 are critical for Wnt signal transduction. The interaction of the Wnts with the receptors is regulated by two classes of extracellular Wnt or LRP binding proteins called sFRP and Dickkopf (DKK), which modulate Wnt signaling. We have examined the expression of all Wnt family members both in the exocrine portion and in isolated islets of adult human pancreas. RT-PCR analysis of the 1-day cultured exocrine pellet fraction from the islet isolation procedure showed that Wnt 2, 2b, 3, 4, 5a, 5b, 7a, 7b, 14, and 15 were detectable. All 10 Frizzled (Frz) receptors were expressed but only Frizzled 1, 2, 4, 5, and 6 strongly. RT-PCR performed on purified human islets revealed that Wnt 2b, 3, 4, 5a, 7b, 10a, and 14 and Frz 4, 5, and 6 were the most highly expressed. DKK 1, 3, and 4 as well as sFRP 1, 4, and 5 were expressed in the exocrine fraction. sFRP 2 and 3 were detectable but only at low levels. In situ hybridization for Frz 1-7 showed that expression colocalized with the islets of Langerhans. Together the data suggest that active Wnt signaling occurs in adult pancreas and is probably important for physiological functions.

Betatrophin.

Regenerative therapy in diabetes with the capacity to reconstitute a functional ß-cell mass sufficient for glycemic control holds the promise to effectively prevent the development of devastating late complications due to the unique ability of the ß-cell to sense and regulate blood-glucose levels. An ability that cannot be mimicked by insulin replacement therapy or any other means of current treatment regiments for very large patient populations. Recently, Douglas A. Melton's group from Harvard University reported the identification of a circulating protein secreted from the liver under insulin resistant states which is sufficient to dramatically and specifically increase the replication rate of ß-cells in the mouse resulting in an increased functional ß-cell mass over time. They re-named the factor betatrophin and described a number of exciting features of this molecule which suggested that it could be a potential candidate for development as a regenerative medicine in diabetes. The official name of the gene encoding mouse betatrophin is Gm6484, but it has been annotated a number of times under different names: EG624219, RIFL, Lipasin and ANGPTL8. The official human gene name is C19orf80, but it has also been annotated as TD26, LOC55908, as well as RIFL, Lipasin, ANGPTL8 and betatrophin.