help button home button Endocrine Society Endocrinology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Purchase Article
Right arrow View Shopping Cart
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Copyright Permission
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Hagenfeldt-Johansson, K. A.
Right arrow Articles by Wollheim, C. B.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Hagenfeldt-Johansson, K. A.
Right arrow Articles by Wollheim, C. B.
Endocrinology Vol. 142, No. 12 5311-5320
Copyright © 2001 by The Endocrine Society


INSULIN-GLUCAGON-GI PEPTIDES-DIABETES MELLITUS

ß-Cell-Targeted Expression of a Dominant-Negative Hepatocyte Nuclear Factor-1{alpha} Induces a Maturity-Onset Diabetes of the Young (MODY)3-Like Phenotype in Transgenic Mice

Kerstin A. Hagenfeldt-Johansson, Pedro L. Herrera, Haiyan Wang, Asllan Gjinovci, Hisamitsu Ishihara and Claes B. Wollheim

Division of Clinical Biochemistry, Department of Internal Medicine (K.A.H.-J., H.W., A.G., H.I., C.B.W.), and Department of Morphology ( P.L.H.), University Medical Center, 1211 Geneva 4, Switzerland

Address all correspondence and requests for reprints to: Claes B. Wollheim, Division of Clinical Biochemistry, Department of Internal Medicine, University Medical Center, 1 rue Michel-Servet, 1211 Geneva 4, Switzerland. E-mail: claes.wollheim{at}medecine.unige.ch


    Abstract
 Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 References
 
Mutations in the transcription factor hepatocyte nuclear factor-1{alpha} (HNF-1{alpha}) cause maturity-onset diabetes of the young 3, a severe form of diabetes characterized by pancreatic ß-cell dysfunction. We have used targeted expression of a dominant-negative mutant of HNF-1{alpha} to specifically suppress HNF-1{alpha} function in ß-cells of transgenic mice. We show that males expressing the mutant protein became overtly diabetic within 6 wk of age, whereas females displayed glucose intolerance. Transgenic males exhibited impaired glucose-stimulated insulin secretion, detected both in vivo and in the perfused pancreas. Pancreatic insulin content was markedly decreased in diabetic animals, whereas the glucagon content was increased. Postnatal islet development was altered, with an increased {alpha}-cell to ß-cell ratio. ß-Cell ultrastructure showed signs of severe ß-cell damage, including mitochondrial swelling. This animal model of maturity-onset diabetes of the young 3 should be useful for the further elucidation of the mechanism by which HNF-1{alpha} deficiency causes ß-cell dysfunction in this disease.


    Introduction
 Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 References
 
MATURITY-ONSET DIABETES of the young (MODY) is a monogenic form of type 2 diabetes characterized by early age of onset (<25 yr) and autosomal dominant transmission. A number of genetically distinct forms of MODY, which together represent 2–5% of type 2 diabetes, have been identified. MODY3, accounting for 65% of MODY cases in the United Kingdom, is the most common, and also the most severe form of MODY. MODY3 patients progressively develop a severe hyperglycemia, which can lead to the typical complications of blindness, gangrene, and renal failure, and require treatment with either oral hypoglycemic agents or insulin (1). Clinical studies have shown that the chronic hyperglycemia observed in MODY3 patients is primarily due to a defect in the insulin-secreting pancreatic ß-cells, rather than in insulin action on target tissues (2, 3, 4).

Mutations in the gene coding for the transcription factor hepatocyte nuclear factor-1{alpha} (HNF-1{alpha}) cause MODY3. The HNF-1{alpha} protein is composed of three functional domains: a short myosin-like amino-terminal dimerization domain, an atypical homeobox DNA-binding domain, and a carboxyl-terminal transactivation domain. Dimerization of HNF-1{alpha} is essential for DNA binding. Patient mutations in any of these domains could lead to diminished amounts of functional HNF-1{alpha} by either a haploinsufficiency or a dominant-negative mechanism.

HNF-1{alpha} was originally characterized as a transcription factor involved in the control of expression of a wide variety of liver-specific genes (5), and has more recently been shown to be an essential transcriptional regulator of bile acid and high density lipoprotein cholesterol metabolism (6). However, HNF-1{alpha} is also expressed in the kidney, intestine, spleen, and the exocrine and endocrine pancreas (7). Notably, HNF-1{alpha} has been shown to regulate genes expressed in the pancreatic ß-cell, such as glucose transporter 2 (Glut-2) and L-type pyruvate kinase (7, 8, 9, 10, 11). HNF-1{alpha} has also been proposed to transactivate the rat insulin I gene (8, 9, 12). Targeted disruption of the hnf-1{alpha} gene in mice indeed results in elevated plasma glucose levels, in addition to hepatomegaly and renal dysfunction (13, 14). However, the pleiotropic effects of the HNF-1{alpha}-knockout complicate the analysis of the precise role of HNF-1{alpha} in determining normal pancreatic ß-cell function. The specific mechanisms by which mutations in HNF-1{alpha} cause MODY3 thus remain unclear.

In this study, we specifically suppressed HNF-1{alpha} function in the ß-cells of transgenic mice. This was achieved by ß-cell-targeted overexpression of a dominant-negative mutant of rat HNF-1{alpha} (DNHNF-1{alpha}). We have previously shown that DNHNF-1{alpha}, which lacks DNA binding activity, exerts its dominant-negative effect by heterodimerizing with endogenous HNF-1{alpha}, thus preventing it from binding to DNA (8). Controlled overexpression of DNHNF-1{alpha} in rat insulinoma cells affects insulin gene transcription and metabolism secretion coupling (8). Here we show that transgenic mice expressing DNHNF-1{alpha} in pancreatic ß-cells develop either glucose intolerance or overt diabetes.


    Materials and Methods
 Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 References
 
Transgenic mice
The rat insulin promoter (RIP)-DNHNF1{alpha} transgene was constructed by inserting the DNHNF-1{alpha} cDNA (8) into a plasmid under the control of the RIP (15), between the rabbit ß-globin intron and polyadenylation site. The transgene fragment was excised from the plasmid vector by enzymatic digestion, separated by gel electrophoresis, and purified on an anion exchange column (NACS-52 PREPAC columns, obtained from Life Technologies, Inc., Rockville, MD).

Transgenic mice were produced by pronuclear microinjection of B6/CBAJ-F1 x B6/CBAJ-F1 zygotes as described (16). DNA solutions were at about 5 ng/µl in a 0.1 mM EDTA-containing buffer. Founder animals were identified by PCR on genomic DNA extracted from tail biopsies (DNeasy tissue kit, QIAGEN AG, Basel, Switzerland). The PCR profile was a standard cycle, repeated 30 times, with 5% DMSO: 94 C for 30 sec, 52 or 47 C for 30 sec, and 68 C for 1 min and 30 sec. The primers (purchased from Microsynth GmbH, Balgach, Switzerland) were: 5', sense primer, 5'-CTGCTAACCATGTTCATGCCT-3'; 3', reverse primer, 5'-TGAATTGCTGAGCCACCTCTC-3' (annealing at 52 C, 770-bp fragment).

Animals were housed in the conventional area of the animal facility of the University of Geneva School of Medicine.

Perfusions
Pancreas perfusions were performed in anesthetized mice as described (17), with a 1.5 ml/min perfusion rate. Released insulin in the effluent was measured by a RIA (8).

Glucose tolerance and insulin release tests
Overnight (15 h)-fasted mice were injected ip with glucose (2 g/kg body wt). Whole blood was collected from the tail vein at 0, 30, 60, 90, and 120 min (for glucose tolerance tests) or at 0 and 15/30 min (for insulin release studies). Blood glucose was measured using a Medisense (Abbott, Baar, Switzerland) Precision QID sensor. Plasma insulin was measured using an ultrasensitive rat insulin ELISA (Mercodia AB, Uppsala, Sweden).

Pancreatic glucagon and insulin content
Dorsal pancreas pieces frozen in liquid nitrogen were pulverized, resuspended in cold acid ethanol (8), and left at 4 C for 48 h, with sonication every 24 h. Insulin content in the acid ethanol supernatant was determined with a rat insulin ELISA (Mercodia AB). Glucagon content in the same extract was measured by RIA (Linco Research, Inc., St. Charles, MO).

Histological analysis: optical and electron microscopy and immunohistochemistry
The animals were killed by cervical dislocation. Dissected pancreas pieces were either fixed in 4% formalin or 2.5% glutaraldehyde and embedded in paraffin or epon 812, respectively. For cryostat sections, tissues were frozen in methylbutane/liquid nitrogen and stored at -80 C; in some cases, they were fixed in 4% paraformaldehyde and equilibrated in 30% sucrose before freezing. For electron microscopy, tissues fixed in glutaraldehyde were postfixed with OsO4 before embedding in epon 812. Sections were incubated with a diluted primary antibody for 2 hr at room temperature, and with an appropriate fluorescein isothiocyanate-conjugated anti-IgG serum for 1 hr. Guinea pig antiporcine insulin was used at 1:400, rabbit antiporcine glucagon at 1:400, rabbit antirat HNF-1{alpha} (obtained from Dr. R. Cortese, Instituto di Richerche de Biologia Molecolare P. Angeletti, Rome, Italy) at 1:200, and rabbit antimouse Glut-2 (obtained from Dr. B. Thorens, Institute of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland) at 1:200. All dilutions were in PBS containing 0.1% (wt/vol) sodium azide and 0.5% BSA. For anti-HNF-1{alpha} staining, the signal was amplified by incubation for 1 hr with a biotin-conjugated antirabbit IgG secondary antibody (Jackson ImmunoResearch Laboratories, Inc., West Grove, PA) and for 1 hr with an ALEXA-conjugated streptavidin complex (Molecular Probes, Inc., Eugene, OR). The anti-HNF-1{alpha} antibody was raised against the N terminus of the protein and hence recognizes both endogenous HNF-1{alpha} and DNHNF-1{alpha}. Sections were counterstained with 0.001% (wt/vol) Evans blue before examination in a Carl Zeiss (Oberkochen, Germany) Axiophot epi-fluorescence microscope.

Ultrastructural analyses were done by using standard copper grids in a JEOL JEM-100CX electron microscope (JEOL GmbH, Eching, Germany). Ultrathin sections were double stained with uranyl acetate and Reynold’s lead citrate. At least two sections from each of a total of three transgenic and three control mice were analyzed.


    Results
 Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 References
 
ß-cell-specific expression of DNHNF-1{alpha} induces diabetes or glucose intolerance
To express DNHNF-1{alpha} in pancreatic ß-cells, we placed the DNHNF-1{alpha} transgene under the transcriptional control of the RIP II (RIP-DNHNF-1{alpha} mice). Six RIP-DNHNF-1{alpha} founder mice were obtained. One female founder became severely diabetic and had no offspring, whereas the transgenic offspring of two other founders died around 3–4 d after birth of severe hyperglycemia. Hence, 3 RIP-DNHNF-1{alpha} transgenic families could be established, 2 of which exhibited no detectable phenotype. Monitoring of fasting blood glucose in the third family, however, showed that transgenic males became markedly diabetic around 6 wk of age (Fig. 1AGo). Although transgenic females remained normoglycemic (at least up to the age of 15 months), an ip glucose tolerance test on 3-month-old females showed that they were glucose intolerant (Fig. 1BGo). Females also exhibited elevated nonfasting blood glucose values at weaning (134% of controls, P < 0.001) similar to males [138% of controls, P < 0.001 (Fig. 1CGo)].



View larger version (50K):
[in this window]
[in a new window]
 
Figure 1. Overexpression of DNHNF-1{alpha} in ß-cells of transgenic mice induces diabetes in males and glucose intolerance in females. A, Evolution of fasting (6 h) blood glucose levels in control (Ctr) and RIP-DNHNF-1{alpha} (Trg) males. RIP-DNHNF-1{alpha} males become overtly diabetic around the age of 6 wk, with a mean fasting glycemia of 18.1 ± 2.01 mM vs. 9.58 ± 1.03 mM in controls. B, Thirteen-week-old females were subjected to an ip (IP) glucose tolerance test after an overnight (15 h) fast (see Materials and Methods). At all time points measured, blood glucose values were significantly higher in RIP-DNHNF-1{alpha} (Trg) than in control (Ctr) females. C, Nonfasting blood glucose levels in 3-wk-old control (Ctr, black bars) and transgenic (Trg, hatched bars) male and female mice. There is a similar increase in nonfasting glycemia in transgenic animals, whether males (10.47 ± 0.56 mM vs. 7.61 ± 0.25 mM in controls) or females (10.13 ± 0.48 mM vs. 7.58 ± 0.35 mM in controls). *, P < 0.05; **, P < 0.01; ***, P < 0.001, as determined using an unpaired two-tailed t test comparing transgenic vs. control animals. Values are presented as mean ± SEM. Numbers in parentheses denote the number of animals analyzed. D, Seven-micrometer thick cryostat sections of pancreas from 6-wk-old mice were stained with an antibody against the amino terminus of HNF-1{alpha}, as described in Materials and Methods. Endogenous levels of HNF-1{alpha} were barely detectable in the islets of control mice (a), whereas overexpression of DNHNF-1{alpha} was detected both in the islets of RIP-DNHNF-1{alpha} males (b) and females (c). Note that the islet shown in panel a is much larger than those shown in panels b and c. Calibration bar, 50 µm.

 
Immunostaining of pancreas sections with an antibody against the N terminus of HNF-1{alpha} indicated clear overexpression of DNHNF-1{alpha} in the ß-cell nuclei of 6-wk-old transgenic males (Fig. 1DGo, panel b). It is noteworthy that a similar overexpression was seen in the ß-cells of the normoglycemic RIP-DNHNF-1{alpha} females (Fig. 1DGo, panel c). In each case, consecutive sections were stained with an antibody against insulin (not shown). RT-PCR on total newborn pancreas RNA also confirmed that the DNHNF-1{alpha} message was expressed in the transgenic animals (not shown). Thus, suppression of HNF-1{alpha} function in the ß-cell induces diabetes in male and glucose intolerance in female mice.

DNHNF-1{alpha} expression affects pancreatic insulin and glucagon contents
We next determined by immunohistochemistry whether DNHNF-1{alpha} expression affects islet structure. Staining of pancreas sections from RIP-DNHNF-1{alpha} mice with an antibody against insulin showed that, at birth, there was no apparent difference in the number and the organization of ß-cells between transgenic and control mice (Fig. 2Go, A and B). However, at 3 wk (the age of weaning), the islets of the transgenic mice started to become disorganized, with fewer ß-cells and heterogeneous insulin immunostaining. This was seen in males (Fig. 2Go, C and D) as well as in females (Fig. 2Go, E and F), and was consistent with the elevated nonfasting blood glucose observed in these animals (cf. Fig. 1CGo). At 10 wk of age, the islets of transgenic RIP-DNHNF-1{alpha} males had a clearly reduced number of ß-cells compared with wild-type littermates (Fig. 2Go, G and H). The islets of the transgenic males were moreover disorganized, with an apparently higher number of {alpha}-cells scattered throughout the islet instead of their normal peripheral localization (Fig. 2Go, I and J).



View larger version (118K):
[in this window]
[in a new window]
 
Figure 2. Islet insulin staining is reduced in RIP-DNHNF-1{alpha} mice. One-micrometer thick semithin sections (A, B, and G–J) and 5- to 7-µm thick paraffin sections (C–F) from RIP-DNHNF-1{alpha} transgenic (B, D, F, H, and J) and control (A, C, E, G, and I) mice were stained with an antibody against insulin (A–H) or glucagon (I and J). A and B, Newborn mice, in which staining does not differ. C–F, Three-week-old males (C and D) and females (E and F). Staining is heterogeneous in transgenics (D and F). G–J, Ten-week-old males. Note that islet architecture, as revealed with an antiglucagon antibody, is disrupted in the transgenics (J). Consecutive sections are shown in panels G and I, and in panels H and J, respectively. Calibration bar, 50 µm.

 
To confirm the immunohistochemical results, we measured total pancreatic insulin and glucagon content at 3, 6, and 10 wk of age in RIP-DNHNF-1{alpha} males and females. The results presented in Table 1Go show that at 3 wk, pancreatic insulin content in transgenic males and females was 42.9 and 35.5% of control, respectively. Subsequently, whereas insulin content in females increased (54.4 and 59.3% of control at 6 and 10 wk, respectively), the insulin content in males continued to decline (31.1% of control at 6 wk) until reaching a mere 21.1% of control at 10 wk. This decrease in insulin content contrasted with the 2.2-fold increase in pancreatic glucagon content observed in 10-wk-old RIP-DNHNF-1{alpha} males compared with controls (Table 1Go).


View this table:
[in this window]
[in a new window]
 
Table 1. Pancreatic insulin and glucagon contents in control and transgenic mice

 
Together, these results thus suggest that the loss of HNF-1{alpha} function in ß-cells leads to a decrease of both pancreatic insulin content and ß-cell number.

DNHNF-1{alpha} expression inhibits insulin secretion
To see whether expression of DNHNF-1{alpha} in ß-cells leads to a specific insulin secretion defect, we perfused the pancreas of 5-wk-old RIP-DNHNF-1{alpha} males (before the onset of diabetes). The insulin secretion profiles of transgenic and control mice are shown in Fig. 3AGo. The perfusion protocol included a 15-min stimulation with 16.7 mM glucose, directly followed by a 16.7 mM glucose plus 20 mM arginine challenge. To calculate the insulin secreted (the area under the curve), we further subdivided the secretory responses into a glucose "first phase," a glucose "second phase," and an "arginine response" (Fig. 3AGo). The results show that the first phase of glucose-stimulated insulin secretion was diminished in transgenic RIP-DNHNF-1{alpha} males (51.3% of control), whereas the second phase was less affected (69.4% of control). The insulin secretory response to arginine in the presence of high glucose was even more reduced [26.9% of control (Fig. 3BGo)].



View larger version (26K):
[in this window]
[in a new window]
 
Figure 3. Impaired insulin secretion in RIP-DNHNF-1{alpha} males. A, Insulin release from the perfused pancreas of control (Ctr, n = 5) and transgenic (Trg, n = 6) 5-wk-old males. The perfusion protocol is shown in boxes on top (arginine was added at a concentration of 20 mM). The areas chosen to calculate the insulin released under the first and second phases of the glucose (Glc) response, as well as under the arginine (arg) response, are delimited by vertical lines. Values are presented as mean ± SEM for each time point. Note that there is a significant difference in the glucose peak value between control and transgenic mice (6.3 ± 1.64 ng/ml and 2.3 ± 0.51 ng/ml, respectively; *, P < 0.05, as determined by an unpaired two-tailed t test). B, The insulin released during the first and second phases of the glucose response, or during the arginine response (arg), was determined by calculating the areas under the curve as shown in A, after subtraction of basal secretion. Ctr, Control (black bars); Trg, transgenic (shaded bars). *, P < 0.05, using an unpaired one-tailed t test. ns, Not significant. Note the logarithmic scale of the y-axis. C, Five-week-old (left panel) and 6-wk-old (right panel) control (Ctr) and transgenic (Trg) RIP-DNHNF-1{alpha} males were subjected to an ip glucose challenge after an overnight (15 h) fast. Plasma insulin levels were measured just before (0'), and 15 or 30 min (15'/30') after glucose injection. *, P < 0.05; **, P < 0.01; ***, P < 0.001, as determined using a paired (comparing the same animals before and after glucose injection) or an unpaired (comparing Ctr and Trg animals) two-tailed t test. ns, Not significant. Bars represent the means. Numbers in parentheses denote the number of animals in each group.

 
We also assessed insulin secretion in vivo using an ip glucose challenge. As shown in the left panel of Fig. 3CGo, 5Go-wk-old RIP-DNHNF-1{alpha} males exhibited a marked inhibition of insulin secretion (1.8-fold induction at 15 min vs. 2.6-fold in controls), similar to what was observed in the perfused pancreas. When the experiment was performed at 6 wk, i.e. the age of onset of hyperglycemia, the ability of RIP-DNHNF-1{alpha} males to secrete insulin in response to glucose was completely abolished (Fig. 3CGo, right panel). Measuring plasma insulin 30 min after the glucose challenge probably contributed to exaggerate the complete blunting of the secretory response. The latter still contrasted with the 2.1-fold increase in secretion seen in control animals.



View larger version (179K):
[in this window]
[in a new window]
 
Figure 5. Ultrastructural lesions in ß-cells of RIP-DNHNF-1{alpha} males. A–F, Electron micrographs of islet cells from 6-wk-old control (A and C) and transgenic (B and D–F) mice. In transgenic mice, non-ß cells (indicated as {delta} and {alpha} in panels E and F, respectively, according to the morphology of their secretory granules) do not have lesions, contrary to what is seen in adjacent ß-cells. m, Swollen mitochondria; e, dilated endoplasmic reticulum cisternae. Bars represent 500 nm.

 
From these data, we conclude that glucose-induced insulin secretion is impaired in RIP-DNHNF-1{alpha} males. This secretory defect is detectable already before the onset of hyperglycemia and worsens with time.

Effects of DNHNF-1{alpha} on Glut-2 expression and ß-cell ultrastructure
Glut-2 is one of the target genes of HNF-1{alpha} in ß-cells (8, 9, 10, 11). We therefore performed immunostaining with an antibody against Glut-2 and found that the sugar carrier was severely down-regulated in the islets of 6-wk-old RIP-DNHNF-1{alpha} males (Fig. 4Go, A–C). The down-regulation of Glut-2 cannot be secondary to a prolonged exposure to hyperglycemia, because at 6 wk, the mice just start to become diabetic.



View larger version (84K):
[in this window]
[in a new window]
 
Figure 4. DNHNF-1{alpha} down-regulates Glut-2 in the ß-cells of transgenic males. A–C, Seven-micrometer thick cryostat sections of pancreas from 6-wk-old control (A) and transgenic (B and C) RIP-DNHNF-1{alpha} males were stained with an antibody against Glut-2 as described in Materials and Methods. As shown in B and C, the sugar transporter is severely down-regulated in the islets of transgenic males, although some ß-cells still exhibit weak Glut2 staining. Calibration bar, 50 µm.

 
To better understand the mechanism underlying the insulin secretory defect and the islet disorganization observed in RIP-DNHNF-1{alpha} males, we then examined the ultrastructure of islet cells by electron microscopy (Fig. 5Go). Already at low magnification, it was evident that most ß-cells of 6-wk-old transgenic males exhibited marked vacuolization (compare Fig. 5Go, B with A). ß-Cells of RIP-DNHNF-1{alpha} males were also shown to contain less mature secretory granules (compare Fig. 5Go, D–F, with C). Moreover, they displayed specific ultrastructural lesions: ß-cell mitochondria were swollen, as shown in Fig. 5Go, D and F, contrasting with the intact organelles seen in a neighboring {alpha}-cell (Fig. 5FGo) or in control ß-cells (Fig. 5CGo). In addition, most transgenic ß-cells appeared highly disorganized, with dilated rough endoplasmic reticulum cisternae (Fig. 5EGo). Together, these alterations suggest that ß-cell death is increased in the islets of transgenic mice. This process is not a typical apoptosis, because no apoptotic bodies nor chromatin condensation were ever observed.


    Discussion
 Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 References
 
MODY3 is one of the most frequent monogenic subforms of type 2 diabetes. ß-Cell dysfunction has been suggested as the primary cause of the disease, which is severe, often requiring insulin therapy (1, 18, 19). Diabetic MODY3 patients display severely impaired glucose-stimulated insulin secretion, with the first phase being particularly affected. Interestingly, nondiabetic carriers of the MODY3 mutation display an intermediary phenotype, with subnormal insulin secretion and decreased glucose tolerance (2, 4). Unlike most type 2 diabetics, MODY3 patients are not insulin resistant (2, 3, 20). Although liver and kidney express high levels of HNF-1{alpha}, the patients do not show signs of altered function of these organs that could explain the etiology of the disease (21). In contrast, HNF-1{alpha}-knockout mice, while being diabetic, suffer from multiple organ manifestations such as renal dysfunction with massive glucosuria, pathological liver tests, and hepatomegaly (13, 14). Although the HNF-1{alpha}-knockout mice have yielded important information (6, 11, 13, 22, 23), the pleiotropic impact of the disruption of the HNF-1{alpha} gene complicates their use for the study of glucose homeostasis.

The transgenic mice with ß-cell-specific suppression of HNF-1{alpha} function described in this study phenotypically resemble MODY3 diabetics and carriers. Indeed, expression of DNHNF-1{alpha} in the ß-cells of RIP-DNHNF-1{alpha} males results in overt diabetes, whereas it only causes impaired glucose tolerance in transgenic females. The severity of the syndrome was paralleled by changes in islet morphology and hormone content. RIP-DNHNF-1{alpha} females exhibited a much milder phenotype than the males, although they showed the same hyperglycemia and reduction in pancreatic insulin content at weaning. The subsequent partial recovery of pancreatic insulin content occurred despite similar DNHNF-1{alpha} expression levels in both sexes. The hormonal profile of the females probably explains this protection from diabetes, as reported in other studies (24, 25). This also indicates that the phenotype of the RIP-DNHNF-1{alpha} males cannot be explained by a nonspecific effect of DNHNF-1{alpha} overexpression.

HNF-1{alpha} has been shown to control insulin gene transcription in rat insulinoma cell lines (8, 9). In RIP-DNHNF-1{alpha} males, there was a gradual decrease in pancreatic insulin content, also seen by immunohistochemistry as an apparent decrease in the number of ß-cells and heterogeneous insulin staining. Ultrastructural analysis confirmed the immunohistochemical observations, showing that most ß-cells in RIP-DNHNF-1{alpha} males exhibited a decrease in the number of mature secretory granules. Reduced expression of other HNF-1{alpha} target genes, including Glut-2, probably contributes to the decreased number of insulin-positive cells seen at 10 wk. The Glut-2-knockout mouse indeed displays a decrease in ß-cell mass (26). In RIP-DNHNF-1{alpha} males, there was also a progressive disorganization of the islets, with an augmented ratio of {alpha}-cells to ß-cells. This islet disorganization could be due, at least in part, to the down-regulation of the cell adhesion molecule E-cadherin observed in a similar mouse model (27). The increased {alpha}-cell to ß-cell ratio was paralleled by an enhanced pancreatic glucagon content, which could contribute to aggravate the diabetic phenotype. It is of interest in this context that the normal suppression of glucagon secretion during a hyperglycemic clamp is impaired in MODY3 patients (3).

Glucose-stimulated insulin secretion was impaired in RIP-DNHNF-1{alpha} males both in vivo and ex vivo. Pancreas perfusions revealed that, as in MODY3 patients (2, 3), the first phase of the secretory response to glucose was attenuated. The response to the combination of arginine and glucose was also markedly inhibited. These results are similar to published data on diabetic HNF-1{alpha}-knockout mice, which exhibit a pronounced suppression of glucose- and arginine-evoked insulin secretion (22). It is of interest that Glut-2-knockout mice, like RIP-DNHNF-1{alpha} males, display a specific loss of the first phase of glucose-induced insulin secretion (26). However, down-regulation of Glut-2 in the ß-cells of RIP-DNHNF-1{alpha} males is apparently not sufficient to explain the secretory defect because the glyceraldehyde-evoked response is preserved in Glut-2- but not in HNF-1{alpha}-knockout mice. The secretory defect observed in RIP-DNHNF-1{alpha} males can already be detected in prediabetic animals, whether assessed in vivo or ex vivo. At the age of onset of diabetes, the in vivo insulin secretory response is completely abolished. Interestingly, this inhibition is more drastic than could be expected from the 70% decrease in pancreatic insulin content observed in these animals. As it is generally assumed that 10% of residual pancreatic insulin content/ß cell mass is enough to maintain euglycemia (28), these results suggest that additional mechanisms could account for the impaired glucose-induced insulin secretion in RIP-DNHNF-1{alpha} males.

Electron microscopy studies indeed revealed ultrastructural lesions in most ß-cells of RIP-DNHNF-1{alpha} males. Variable degrees of cell damage could be observed, such as prominent disorganization of the rough endoplasmic reticulum appearing as dilated cisternae, mitochondrial swelling, and reduced numbers of fully mature secretory granules. Some cells were clearly dying, exhibiting general vacuolization, but neither apoptotic bodies nor chromatin condensation were ever observed in the damaged ß-cells of RIP-DNHNF-1{alpha} males. Interestingly, it has been reported before that ß-cell death can occur without characteristic features of apoptosis (29). Moreover, it has been shown that cellular ATP is needed for a cell to undergo classical apoptosis, with chromatin condensation and fragmentation (30, 31, 32). It is of interest in this context that overexpression of DNHNF-1{alpha} in a rat insulinoma cell line leads to impaired mitochondrial glucose oxidation and ATP production (8). Similarly, glucose-induced mitochondrial hyperpolarization, an essential step in ß-cell activation, is diminished in a cell line expressing a human HNF-1{alpha} mutant (9). The ultrastructural lesions and the inhibition of insulin secretion observed in RIP-DNHNF-1{alpha} males are thus compatible with deficient ATP generation by the mitochondria. The resulting increased ß-cell death could also explain the disorganization of the islets in transgenic mice.

In conclusion, the results presented here suggest that suppression of HNF-1{alpha} function affects ß-cell metabolism downstream of glucose transport. Our transgenic mouse model with ß-cell-specific suppression of HNF-1{alpha} function clearly demonstrates that ß-cell dysfunction must be the primary cause of MODY3. Studies on these animals should help to further clarify the role of HNF-1{alpha} in ß-cell pathophysiology, and could serve to define HNF-1{alpha} target genes in addition to those described to date (8, 9, 11). Indeed, because HNF-1{alpha} is a transcription factor, it is to be anticipated that its suppression in the ß-cell changes the expression of as many genes as was reported recently for the liver (6). The spectrum of metabolic derangements in the transgenic mice, ranging from impaired glucose tolerance to frank diabetes, make them ideal for the development of novel therapeutic strategies for MODY3.


    Acknowledgments
 
We are most grateful to E.-J. Sarret, J. Ritz, G. Flores, O. Dupont, C. Raveraud, D. Ben-Nashr, J. Bassi, D. Cornut-Harry, Y. Dupré, N. Steiner, and E. Dubois for expert technical assistance. We thank Dr. Yamagata, as well as Drs. P. Antinozzi, P. Maechler, and C. Broca, for fruitful discussions. We also acknowledge the helpful input of Dr. G. MacGregor. We are indebted to Dr. B. Thorens for the Glut-2 antibody and to Dr. R. Cortese for the HNF-1{alpha} antibody. We also thank Dr. P. Meda, J. Gunn, and F. De Leon for their help.


    Footnotes
 
This work was supported by Swiss National Science Foundation Grant Nos. 32-49755.96 (to C.B.W.) and 31-53027.97 (to P.L.H.). It was also supported by the Juvenile Diabetes Research Foundation (C.B.W. and P.L.H.), the Bonizzi-Theler Stiftung, Zürich (C.B.W.), and the Novartis Foundation, Basel (C.B.W.).

Abbreviations: DNHNF-1{alpha}, Dominant-negative mutant of rat HNF-1{alpha}; Glut-2; glucose transporter 2; HNF-1{alpha}, hepatocyte nuclear factor 1{alpha}; MODY, maturity-onset diabetes of the young; RIP, rat insulin promoter.

Received August 2, 2001.

Accepted for publication September 1, 2001.


    References
 Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 References
 

  1. Hattersley AT 1998 Maturity-onset diabetes of the young: clinical heterogeneity explained by genetic heterogeneity. Diabet Med 15:15–24[CrossRef][Medline]
  2. Lehto M, Tuomi T, Mahtani MM, Widen E, Forsblom C, Sarelin L, Gullstrom M, Isomaa B, Lehtovirta M, Hyrkko A, Kanninen T, Orho M, Manley S, Turner RC, Brettin T, Kirby A, Thomas J, Duyk G, Lander E, Taskinen MR, Groop L 1997 Characterization of the MODY3 phenotype. Early-onset diabetes caused by an insulin secretion defect. J Clin Invest 99:582–591[Medline]
  3. Surmely JF, Guenat E, Philippe J, Dussoix P, Schneiter P, Temler E, Vaxillaire M, Froguel P, Jequier E, Tappy L 1998 Glucose utilization and production in patients with maturity-onset diabetes of the young caused by a mutation of the hepatocyte nuclear factor-1{alpha} gene. Diabetes 47:1459–1463[Abstract/Free Full Text]
  4. Byrne MM, Sturis J, Menzel S, Yamagata K, Fajans SS, Dronsfield MJ, Bain SC, Hattersley AT, Velho G, Froguel P, Bell GI, Polonsky KS 1996 Altered insulin secretory responses to glucose in diabetic and nondiabetic subjects with mutations in the diabetes susceptibility gene MODY3 on chromosome 12. Diabetes 45:1503–1510[Abstract]
  5. Nicosia A, Monaci P, Tomei L, De Francesco R, Nuzzo M, Stunnenberg H, Cortese R 1990 A myosin-like dimerization helix and an extra-large homeodomain are essential elements of the tripartite DNA binding structure of LFB1. Cell 61:1225–1236[CrossRef][Medline]
  6. Shih DQ, Bussen M, Sehayek E, Ananthanarayanan M, Shneider BL, Suchy FJ, Shefer S, Bollileni JS, Gonzalez FJ, Breslow JL, Stoffel M 2001 Hepatocyte nuclear factor-1{alpha} is an essential regulator of bile acid and plasma cholesterol metabolism. Nat Genet 27:375–382[CrossRef][Medline]
  7. Miquerol L, Lopez S, Cartier N, Tulliez M, Raymondjean M, Kahn A 1994 Expression of the L-type pyruvate kinase gene and the hepatocyte nuclear factor 4 transcription factor in exocrine and endocrine pancreas. J Biol Chem 269:8944–8951[Abstract/Free Full Text]
  8. Wang H, Maechler P, Hagenfeldt KA, Wollheim CB 1998 Dominant-negative suppression of HNF-1{alpha} function results in defective insulin gene transcription and impaired metabolism-secretion coupling in a pancreatic ß-cell line. EMBO J 17:6701–6713[CrossRef][Medline]
  9. Wang H, Antinozzi PA, Hagenfeldt KA, Maechler P, Wollheim CB 2000 Molecular targets of a human HNF1{alpha} mutation responsible for pancreatic ß-cell dysfunction. EMBO J 19:4257–4264[CrossRef][Medline]
  10. Cha JY, Kim H, Kim KS, Hur MW, Ahn Y 2000 Identification of transacting factors responsible for the tissue-specific expression of human glucose transporter type 2 isoform gene: cooperative role of hepatocyte nuclear factors 1{alpha} and 3ß. J Biol Chem 275:18358–65[Abstract/Free Full Text]
  11. Parrizas M, Maestro MA, Boj SF, Paniagua A, Casamitjana R, Gomis R, Rivera F, Ferrer J 2001 Hepatic nuclear factor 1-{alpha} directs nucleosomal hyperacetylation to its tissue-specific transcriptional targets. Mol Cell Biol 21:3234–3243[Abstract/Free Full Text]
  12. Emens LA, Landers DW, Moss LG 1992 Hepatocyte nuclear factor 1{alpha} is expressed in a hamster insulinoma line and transactivates the rat insulin I gene. Proc Natl Acad Sci USA 89:7300–7304[Abstract/Free Full Text]
  13. Lee YH, Sauer B, Gonzalez FJ 1998 Laron dwarfism and non-insulin-dependent diabetes mellitus in the Hnf-1{alpha} knockout mouse. Mol Cell Biol 18:3059–3068[Abstract/Free Full Text]
  14. Pontoglio M, Barra J, Hadchouel M, Doyen A, Kress C, Bach JP, Babinet C, Yaniv M 1996 Hepatocyte nuclear factor 1 inactivation results in hepatic dysfunction, phenylketonuria, and renal Fanconi syndrome. Cell 84:575–585[CrossRef][Medline]
  15. Hanahan D 1985 Heritable formation of pancreatic ß-cell tumours in transgenic mice expressing recombinant insulin/simian virus 40 oncogenes. Nature 315:115–122[CrossRef][Medline]
  16. Hogan B, Beddington R, Costantini F, Lacy E 1994 Manipulating the mouse embryo: a laboratory manual. 2nd ed. Plainview, NY: Cold Spring Harbor Laboratory Press
  17. Charollais A, Gjinovci A, Huarte J, Bauquis J, Nadal A, Martin F, Andreu E, Sanchez-Andres JV, Calabrese A, Bosco D, Soria B, Wollheim CB, Herrera PL, Meda P 2000 Junctional communication of pancreatic ß cells contributes to the control of insulin secretion and glucose tolerance. J Clin Invest 106:235–243[Medline]
  18. Fajans SS, Bell GI, Polonsky KS 2001 Molecular mechanisms and clinical pathophysiology of maturity-onset diabetes of the young. N Engl J Med 345:971–80[Free Full Text]
  19. Velho G, Froguel P 1998 Genetic, metabolic and clinical characteristics of maturity onset diabetes of the young. Eur J Endocrinol 138:233–239[Abstract]
  20. Tripathy D, Carlsson AL, Lehto M, Isomaa B, Tuomi T, Groop L 2000 Insulin secretion and insulin sensitivity in diabetic subgroups: studies in the prediabetic and diabetic state. Diabetologia 43:1476–1483[CrossRef][Medline]
  21. Iwasaki N, Ogata M, Tomonaga O, Kuroki H, Kasahara T, Yano N, Iwamoto Y 1998 Liver and kidney function in Japanese patients with maturity-onset diabetes of the young. Diabetes Care 21:2144–2148[Abstract]
  22. Pontoglio M, Sreenan S, Roe M, Pugh W, Ostrega D, Doyen A, Pick AJ, Baldwin A, Velho G, Froguel P, Levisetti M, Bonner-Weir S, Bell GI, Yaniv M, Polonsky KS 1998 Defective insulin secretion in hepatocyte nuclear factor 1{alpha}-deficient mice. J Clin Invest 101:2215–2222[Medline]
  23. Dukes ID, Sreenan S, Roe MW, Levisetti M, Zhou YP, Ostrega D, Bell GI, Pontoglio M, Yaniv M, Philipson L, Polonsky KS 1998 Defective pancreatic ß-cell glycolytic signaling in hepatocyte nuclear factor-1{alpha}-deficient mice. J Biol Chem 273:24457–24464[Abstract/Free Full Text]
  24. Efrat S 1991 Sexual dimorphism of pancreatic ß-cell degeneration in transgenic mice expressing an insulin-ras hybrid gene. Endocrinology 128:897–901[Abstract]
  25. Thomas MK, Devon ON, Lee JH, Peter A, Schlosser DA, Tenser MS, Habener JF 2001 Development of diabetes mellitus in aging transgenic mice following suppression of pancreatic homeoprotein IDX-1. J Clin Invest 108:319–329[CrossRef][Medline]
  26. Guillam MT, Hummler E, Schaerer E, Yeh JI, Birnbaum MJ, Beermann F, Schmidt A, Deriaz N, Thorens B, Wu JY 1997 Early diabetes and abnormal postnatal pancreatic islet development in mice lacking Glut-2. Nat Genet 17:327–330[Medline]
  27. Nammo T, Yamagata K, Moriwaki M, Yang Q, Uenaka R, Okita K, Li M, Imagawa A, Miyagawa J, Matsuzawa Y 2001 Dominant negative HNF-1{alpha}mutant affects the expression of cell adhesion molecules involved in the ß-cell. Diabetes 50:A346
  28. Weir GC, Bonner-Weir S, Leahy JL 1990 Islet mass and function in diabetes and transplantation. Diabetes 39:401–405[Abstract]
  29. Herrera PL, Harlan DM, Vassalli P 2000 A mouse CD8 T cell-mediated acute autoimmune diabetes independent of the perforin and Fas cytotoxic pathways: possible role of membrane TNF. Proc Natl Acad Sci USA 97:279–284[Abstract/Free Full Text]
  30. Nicotera P, Leist M 1997 Energy supply and the shape of death in neurons and lymphoid cells. Cell Death Differ 4:435–442
  31. Eguchi Y, Shimizu S, Tsujimoto Y 1997 Intracellular ATP levels determine cell death fate by apoptosis or necrosis. Cancer Res 57:1835–1840[Abstract/Free Full Text]
  32. Leist M, Single B, Castoldi AF, Kuhnle S, Nicotera P 1997 Intracellular adenosine triphosphate (ATP) concentration: a switch in the decision between apoptosis and necrosis. J Exp Med 185:1481–1486[Abstract/Free Full Text]



This article has been cited by other articles:


Home page
Genes Dev.Home page
R. K. Gupta, N. Gao, R. K. Gorski, P. White, O. T. Hardy, K. Rafiq, J. E. Brestelli, G. Chen, C. J. Stoeckert Jr., and K. H. Kaestner
Expansion of adult beta-cell mass in response to increased metabolic demand is dependent on HNF-4{alpha}
Genes & Dev., April 1, 2007; 21(7): 756 - 769.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Physiol. Renal Physiol.Home page
Y. Kanetsuna, K. Hirano, M. Nagata, M. A. Gannon, K. Takahashi, R. C. Harris, M. D. Breyer, and T. Takahashi
Characterization of diabetic nephropathy in a transgenic model of hypoinsulinemic diabetes
Am J Physiol Renal Physiol, December 1, 2006; 291(6): F1315 - F1322.
[Abstract] [Full Text] [PDF]


Home page
DiabetesHome page
R. F. Luco, M. A. Maestro, N. del Pozo, W. M. Philbrick, P. P. de la Ossa, and J. Ferrer
A Conditional Model Reveals That Induction of Hepatocyte Nuclear Factor-1{alpha} in Hnf1{alpha}-Null Mutant {beta}-Cells Can Activate Silenced Genes Postnatally, Whereas Overexpression Is Deleterious.
Diabetes, August 1, 2006; 55(8): 2202 - 2211.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
B. Ahren and G. Pacini
A novel approach to assess insulin sensitivity reveals no increased insulin sensitivity in mice with a dominant-negative mutant hepatocyte nuclear factor-1{alpha}
Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2006; 291(1): R131 - R137.
[Abstract] [Full Text] [PDF]


Home page
DiabetesHome page
M. S. Winzell, G. Pacini, C. B. Wollheim, and B. Ahren
Beta-Cell-Targeted Expression of a Dominant-Negative Mutant of Hepatocyte Nuclear Factor-1{alpha} in Mice: Diabetes Model with {beta}-Cell Dysfunction Partially Rescued by Nonglucose Secretagogues
Diabetes, December 1, 2004; 53(suppl_3): S92 - S96.
[Abstract] [Full Text] [PDF]


Home page
Nucleic Acids ResHome page
H. Thomas, S. Senkel, S. Erdmann, T. Arndt, G. Turan, L. Klein-Hitpass, and G. U. Ryffel
Pattern of genes influenced by conditional expression of the transcription factors HNF6, HNF4{alpha} and HNF1{beta} in a pancreatic {beta}-cell line
Nucleic Acids Res., November 1, 2004; 32(19): e150 - e150.
[Abstract] [Full Text] [PDF]


Home page
EndocrinologyHome page
L. Wang, C. Coffinier, M. K. Thomas, L. Gresh, G. Eddu, T. Manor, L. L. Levitsky, M. Yaniv, and D. B. Rhoads
Selective Deletion of the Hnf1{beta} (MODY5) Gene in {beta}-Cells Leads to Altered Gene Expression and Defective Insulin Release
Endocrinology, August 1, 2004; 145(8): 3941 - 3949.
[Abstract] [Full Text] [PDF]


Home page
J. Physiol.Home page
S. Sedej, T. Tsujimoto, R. Zorec, and M. Rupnik
Voltage-activated Ca2+ channels and their role in the endocrine function of the pituitary gland in newborn and adult mice
J. Physiol., March 15, 2004; 555(3): 769 - 782.
[Abstract] [Full Text] [PDF]


Home page
EndocrinologyHome page
J. Eeckhoute, E. Moerman, T. Bouckenooghe, B. Lukoviak, F. Pattou, P. Formstecher, J. Kerr-Conte, B. Vandewalle, and B. Laine
Hepatocyte Nuclear Factor 4{alpha} Isoforms Originated from the P1 Promoter Are Expressed in Human Pancreatic {beta}-Cells and Exhibit Stronger Transcriptional Potentials than P2 Promoter-Driven Isoforms
Endocrinology, May 1, 2003; 144(5): 1686 - 1694.
[Abstract] [Full Text] [PDF]


Home page
DiabetesHome page
H. Wang, K. Hagenfeldt-Johansson, L. A. Otten, B. R. Gauthier, P. L. Herrera, and C. B. Wollheim
Experimental Models of Transcription Factor-Associated Maturity-Onset Diabetes of the Young
Diabetes, December 1, 2002; 51(90003): S333 - 342.
[Abstract] [Full Text] [PDF]


Home page
DiabetesHome page
J. Ferrer
A Genetic Switch in Pancreatic {beta}-Cells: Implications for Differentiation and Haploinsufficiency
Diabetes, August 1, 2002; 51(8): 2355 - 2362.
[Abstract] [Full Text] [PDF]


Home page
DiabetesHome page
Q. Yang, K. Yamagata, K. Fukui, Y. Cao, T. Nammo, H. Iwahashi, H. Wang, I. Matsumura, T. Hanafusa, R. Bucala, et al.
Hepatocyte Nuclear Factor-1{alpha} Modulates Pancreatic {beta}-Cell Growth by Regulating the Expression of Insulin-Like Growth Factor-1 in INS-1 Cells
Diabetes, June 1, 2002; 51(6): 1785 - 1792.
[Abstract] [Full Text] [PDF]


This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Purchase Article
Right arrow View Shopping Cart
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Copyright Permission
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Hagenfeldt-Johansson, K. A.
Right arrow Articles by Wollheim, C. B.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Hagenfeldt-Johansson, K. A.
Right arrow Articles by Wollheim, C. B.


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS