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Background The diagnosis of atypical non-autoimmune forms of diabetes mellitus, such as maturity onset diabetes of the young (MODY) presents several challenges, in view of the extensive clinical and genetic heterogeneity of the disease. In this report we describe a case of atypical non autoimmune diabetes associated with a damaging HNF1β mutation. This is distinguished by a number of uncharacteristic clinical features, including early-onset obesity, the absence of renal cysts and diabetic nephropathy. HNF1β-MODY (MODY5) is an uncommon form of monogenic diabetes that is often complicated by a wide array of congenital morphological anomalies of the urinary tract, including renal cysts. This report expands on the clinical phenotypes that have been described in the context of HNF1β mutations, and is relevant as only isolated cases of diabetic nephropathy in the setting of MODY5 have been reported. Case presentation An obese Maltese female with non-autoimmune diabetes, microalbuminuria, glomerular hyperfiltration, fatty liver and no renal cysts was studied by whole exome sequencing to investigate potential genes responsible for the proband’s phenotype. A rare missense mutation at a highly conserved site in exon 8 of HNF1β was identified (c.1580G > A, NM_000458.3, p.Arg527Gln), with multiple in-silico predictions consistent with pathogenicity. This mutation has not been previously characterised. Additionally, several common susceptibility variants associated with early-onset obesity, polygenic type 2 diabetes and nephropathy were identified in the proband that could impose additional effects on the phenotype, its severity or its clinical course. Conclusion This report highlights several atypical features in a proband with atypical diabetes associated with an HNF1β missense mutation. It also reinforces the concept that monogenic causes of diabetes could be significant contributors to disease burden in obese individuals with atypical diabetes., peer-reviewed

HNF1B gene mutations are an important cause of bilateral (cystic) dysplasia in children, complicated by chronic renal insufficiency. The clinical variability, the absence of genotype-phenotype correlations, and limited long-term data render counseling of affected families difficult. Longitudinal data of 62 children probands with genetically proven HNF1B nephropathy was obtained in a multicenter approach. Genetic family cascade screening was performed in 30/62 cases. Eighty-seven percent of patients had bilateral dysplasia, 74% visible bilateral, and 16% unilateral renal cysts at the end of observation. Cyst development was non-progressive in 72% with a mean glomerular filtration rate (GFR) loss of − 0.33 ml/min/1.73m2 per year (± 8.9). In patients with an increase in cyst number, the annual GFR reduction was − 2.8 ml/min/1.73m2 (± 13.2), in the total cohort − 1.0 ml/min/1.73m2 (±10.3). A subset of HNF1B patients differs from this group and develops end stage renal disease (ESRD) at very early ages

Mitochondrial dysfunction is increasingly recognized as a critical determinant of both hereditary and acquired kidney diseases. However, it remains poorly understood how mitochondrial metabolism is regulated to support normal kidney function and how its dysregulation contributes to kidney disease. Here, we show that the nuclear receptor estrogen-related receptor gamma (ERRγ) and hepatocyte nuclear factor 1 beta (HNF1β) link renal mitochondrial and reabsorptive functions through coordinated epigenomic programs. ERRγ directly regulates mitochondrial metabolism but cooperatively controls renal reabsorption via convergent binding with HNF1β. Deletion of ERRγ in renal epithelial cells (RECs), in which it is highly and specifically expressed, results in severe renal energetic and reabsorptive dysfunction and progressive renal failure that recapitulates phenotypes of animals and patients with HNF1β loss-of-function gene mutations. Moreover, ERRγ expression positively correlates with renal function and is decreased in patients with chronic kidney disease (CKD). REC-ERRγ KO mice share highly overlapping renal transcriptional signatures with human patients with CKD. Together these findings reveal a role for ERRγ in directing independent and HNF1β-integrated programs for energy production and use essential for normal renal function and the prevention of kidney disease.

Hepatocyte nuclear factor-1β (HNF-1β) is an essential transcription factor that regulates the development and function of epithelia in the kidney, liver, pancreas, and genitourinary tract. Humans who carry HNF1B mutations develop heterogeneous renal abnormalities, including multicystic dysplastic kidneys, glomerulocystic kidney disease, renal agenesis, renal hypoplasia, and renal interstitial fibrosis. In the embryonic kidney, HNF-1β is required for ureteric bud branching, initiation of nephrogenesis, and nephron segmentation. Ablation of mouse Hnf1b in nephron progenitors causes defective tubulogenesis, whereas later inactivation in elongating tubules leads to cyst formation due to downregulation of cystic disease genes, including Umod, Pkhd1, and Pkd2. In the adult kidney, HNF-1β controls the expression of genes required for intrarenal metabolism and solute transport by tubular epithelial cells. Tubular abnormalities observed in HNF-1β nephropathy include hyperuricemia with or without gout, hypokalemia, hypomagnesemia, and polyuria. Recent studies have identified novel post-transcriptional and post-translational regulatory mechanisms that control HNF-1β expression and activity, including the miRNA cluster miR17 ∼ 92 and the interacting proteins PCBD1 and zyxin. Further understanding of the molecular mechanisms upstream and downstream of HNF-1β may lead to the development of new therapeutic approaches in cystic kidney disease and other HNF1B-related renal diseases.

Background & Aims The exocrine pancreas consists of acinar cells that produce digestive enzymes transported to the intestine through a branched ductal epithelium. Chronic pancreatitis is characterized by progressive inflammation, fibrosis, and loss of acinar tissue. These changes of the exocrine tissue are risk factors for pancreatic cancer. The cause of chronic pancreatitis cannot be identified in one quarter of patients. Here, we investigated how duct dysfunction could contribute to pancreatitis development. Methods The transcription factor Hnf1b, first expressed in pancreatic progenitors, is strictly restricted to ductal cells from late embryogenesis. We previously showed that Hnf1b is crucial for pancreas morphogenesis but its postnatal role still remains unelucidated. To investigate the role of pancreatic ducts in exocrine homeostasis, we inactivated the Hnf1b gene in vivo in mouse ductal cells. Results We uncovered that postnatal Hnf1b inactivation in pancreatic ducts leads to chronic pancreatitis in adults. Hnf1bΔduct mutants show dilatation of ducts, loss of acinar cells, acinar-to-ductal metaplasia, and lipomatosis. We deciphered the early events involved, with down-regulation of cystic disease–associated genes, loss of primary cilia, up-regulation of signaling pathways, especially the Yap pathway, which is involved in acinar-to-ductal metaplasia. Remarkably, Hnf1bΔduct mutants developed pancreatic intraepithelial neoplasia and promote pancreatic intraepithelial neoplasia progression in concert with KRAS. We further showed that adult Hnf1b inactivation in pancreatic ducts is associated with impaired regeneration after injury, with persistent metaplasia and initiation of neoplasia. Conclusions Loss of Hnf1b in ductal cells leads to chronic pancreatitis and neoplasia. This study shows that Hnf1b deficiency may contribute to diseases of the exocrine pancreas and gains further insight into the etiology of pancreatitis and tumorigenesis., Graphical abstract

Objective To elucidate the immunohistochemical (IHC) differences of endometrioma tissues that may have the potential to progress to ovarian clear cell carcinoma (OCCC) by using KRAS, HNF1β, PIK3CA, PPP2R1A, and ARID1A as biomarkers. Study design This is a retrospective clinical study, which was conducted in an university hospital. The groups comprised 14 patients with endometrioma resection who later developed OCCC (non-healthy endometrioma-case group) and 66 patients with endometrioma resection who did not develop ovarian cancer in subsequent follow-ups (healthy endometrium-control group). IHC staining with KRAS, HNF1β, PIK3CA, PPP2R1A, and ARID1A antibodies was performed in paraffin blocks of endometriomas obtained in both groups. For KRAS, PIK3CA, PPP2R1A, and ARID1A, cell staining intensity on a scale from 0 (negative) to 3 (strongly positive), and for HNF1β, the percentage of stained cells (0–5) and the intensity of staining (0–3) were scored. Results KRAS, HNF1β, PIK3CA, PPP2R1A, and ARID1A were overexpressed in the case group samples compared with the endometrioma samples in the epithelial cells, and ARID1A and KRAS in the stroma were overexpressed in the case group samples compared with the matched control samples. Conclusions KRAS, HNF1β, PIK3CA, PPP2R1A, and ARID1A immunostaining scores in endometriomas previous to OCCC were significantly different than in endometriomas with no malignancy occurring in subsequent follow-ups, and were single predictors of OCCC. Hence, immunostaining with these biomarkers may be a method of identifying patients with endometrioma who have the potential to develop OCCC.

Identification of the yolk sac tumor (YST) component in germ cell tumors (GCT) may prove challenging, and highly sensitive and specific immunohistochemical markers are still lacking. Preliminary data from the literature suggest that HNF1β may represent a sensitive marker of YST. The specificity of HNF1β has not been addressed in GCT. A cohort of 49 YST specimens from 45 patients was designed, occurring either as pure tumors, or as a component of a mixed GCT. Immunohistochemistry was conducted on whole tumor sections using HNF1β. SALL4, OCT4, CD30, CDX2, Cytokeratin 19, Glypican 3, and GATA3 were used for classification of the GCT components. Patients were mostly male (39/45), aged 14 months to 49 years, with primary testicular tumors (37/39), or primary mediastinal pure YSTs (2/39). All 6 primary tumors occurring in females (6/45) were pure ovarian YSTs; age range was 4 to 72 years. HNF1β nuclear reactivity was seen in the YST component in all 49 tumors, with a moderate to strong nuclear pattern of staining. Embryonal carcinoma (EC, 0/32) and seminoma (0/6) were negative. Choriocarcinoma (6/6) showed faint focal cytoplasmic reactivity to HNF1β but no nuclear staining. In teratomas, only enteric-type glands showed nuclear reactivity to HNF1β (11/16). Therefore, HNF1β sensitivity in YST component identification was 100% and specificity was 80%. Thus, in our experience, HNF1β is a sensitive and reliable marker of the YST component in GCT, and allows distinction of YST from intricately admixed EC, especially in the diffuse embryoma pattern.

Renal cell carcinoma (RCC) is the most common tumor of the kidney and its major histologic subtype is clear cell RCC (ccRCC). About 30% of diagnosed ccRCCs already have metastasis. Traditionally, localized ccRCC is treated with nephrectomy but the relapse rate is 30%. Thus, the discovery of effective biomarkers for early detection, as well as the identification of new targets for molecular-based therapy of ccRCC are urgently required. In this study, we focused on molecules that could modulate the trascription of the enzyme nicotinamide N-methyltransferase (NNMT) that is known to be up-regulated in ccRCC. Signal transducer and activator of transcription 3 (STAT3), interleukin 6 (IL-6), hepatocyte nuclear factor 1 beta (HNF-1β) and transforming growth factor beta 1 (TGF-β1) expression levels were determined in tumor and non tumor samples obtained from 30 patients with ccRCC, using Real-Time PCR. Results obtained showed that TGF-β1 is significantly (p

International audience; Glycogen storage disease type I (GSDI) is a rare genetic pathology characterized by glucose-6 phosphatase (G6Pase) deficiency, translating in hypoglycemia during short fasts. Besides metabolic perturbations, GSDI patients develop long-term complications, especially chronic kidney disease (CKD). In GSDI patients, CKD is characterized by an accumulation of glycogen and lipids in kidneys, leading to a gradual decline in renal function. At a molecular level, the activation of the renin-angiotensin system is responsible for the development of renal fibrosis, eventually leading to renal failure. The same CKD phenotype was observed in a mouse model with a kidney-specific G6Pase deficiency (K.G6pc-/- mice). Furthermore, GSDI patients and mice develop frequently renal cysts at late stages of the nephropathy, classifying GSDI as a potential polycystic kidney disease (PKD). PKDs are genetic disorders characterized by multiple renal cyst formation, frequently caused by the loss of expression of polycystic kidney genes, such as PKD1/2 and PKHD1. Interestingly, these genes are deregulated in K.G6pc-/- kidneys, suggesting their possible role in GSDI cystogenesis. Finally, renal cysts are known to predispose to renal malignancy development. In addition, HNF1B loss is a malignancy prediction factor. Interestingly, Hnf1b expression was decreased in K.G6pc-/- kidneys. While a single case of renal cancer has been reported in a GSDI patient, a clear cell renal carcinoma was recently observed in one K.G6pc-/- mouse (out of 36 studied mice) at a later stage of the disease. This finding highlights the need to further analyze renal cyst development in GSDI patients in order to evaluate the possible associated risk of carcinogenesis, even if the risk might be limited.

Mutations in hepatocyte nuclear factor 1β (HNF1β) cause autosomal dominant tubulointerstitial kidney disease (ADTKD-HNF1β), and patients tend to develop renal cysts, maturity-onset diabetes of the young (MODY), and suffer from electrolyte disturbances, including hypomagnesemia, hypokalemia, and hypocalciuria. Previous HNF1β research focused on the renal distal convoluted tubule (DCT) to elucidate the ADTKD-HNF1β electrolyte phenotype, although 70% of Mg2+ is reabsorbed in the thick ascending limb of Henle’s loop (TAL). An important regulator of Mg2+ reabsorption in the TAL is the calcium-sensing receptor (CaSR). This study used several methods to elucidate the role of HNF1β in electrolyte reabsorption in the TAL. HNF1β ChIP-seq data revealed a conserved HNF1β binding site in the second intron of the CaSR gene. Luciferase-promoter assays displayed a 5.8-fold increase in CaSR expression when HNF1β was present. Expression of the HNF1β p.Lys156Glu mutant, which prevents DNA binding, abolished CaSR expression. Hnf1β knockdown in an immortalized mouse kidney TAL cell line (MKTAL) reduced expression of the CaSR and Cldn14 (claudin 14) by 56% and 48%, respectively, while Cldn10b expression was upregulated 5.0-fold. These results were confirmed in a kidney-specific HNF1β knockout mouse, which exhibited downregulation of the Casr by 81%. Cldn19 and Cldn10b expression levels were also decreased by 37% and 83%, respectively, whereas Cldn3 was upregulated by 4.6-fold. In conclusion, HNF1β is a transcriptional activator of the CaSR. Consequently, patients with HNF1β mutations may have reduced CaSR activity in the kidney, which could explain cyst progression and hyperabsorption of Ca2+ and Mg2+ in the TAL resulting in hypocalciuria.

Multigenerational diabetes of adulthood is a mostly overlooked entity, simplistically lumped into the large pool of type 2 diabetes. The general aim of our research in the past few years is to unravel the genetic causes of this form of diabetes. Identifying among families with multigenerational diabetes those who carry mutations in known monogenic diabetes genes is the first step to then allow us to concentrate on remaining pedigrees in which to unravel new diabetes genes. Targeted next-generation sequencing of 27 monogenic diabetes genes was carried out in 55 family probands and identified mutations verified among their relatives by Sanger sequencing. Nine variants (in eight probands) survived our filtering/prioritization strategy. After likelihood of causality assessment by established guidelines, six variants were classified as “pathogenetic/likely pathogenetic” and two as “of uncertain significance.” Combining present results with our previous data on the six genes causing the most common forms of maturity-onset diabetes of the young allows us to infer that 23.6% of families with multigenerational diabetes of adulthood carry mutations in known monogenic diabetes genes. Our findings indicate that the genetic background of hyperglycemia is unrecognized in the vast majority of families with multigenerational diabetes of adulthood. These families now become the object of further research aimed at unraveling new diabetes genes.

In the present study, we performed a metabolomics analysis to evaluate a MODY5/RCAD mouse mutant line as a potential model for HNF1B-associated diseases. Gas chromatography time-of-flight mass spectrometry (GC-TOF-MS) of gut, kidney, liver, muscle, pancreas, and plasma samples uncovered the tissue specific metabolite distribution. Orthogonal projections to latent structures discriminant analysis (OPLS-DA) was used to identify the differences between MODY5/RCAD and wild-type mice in each of the tissues. The differences included, for example, increased levels of amino acids in the kidneys and reduced levels of fatty acids in the muscles of the MODY5/RCAD mice. Interestingly, campesterol was found in higher concentrations in the MODY5/RCAD mice, with a four-fold and three-fold increase in kidneys and pancreas, respectively. As expected, the MODY5/RCAD mice displayed signs of impaired renal function in addition to disturbed liver lipid metabolism, with increased lipid and fatty acid accumulation in the liver. From a metabolomics perspective, the MODY5/RCAD model was proven to display a metabolic pattern similar to what would be suspected in HNF1B-associated diseases. These findings were in line with the presumed outcome of the mutation based on the different anatomy and function of the tissues as well as the effect of the mutation on development.

Hepatocyte nuclear factor 1-beta (HNF-1-beta) is a transcription factor involved in cancerogenesis of various tumors, including endometrioid carcinoma. We performed comprehensive analysis of HNF-1-beta in lesions of the endometrium, including protein expression and genetic and epigenetic changes. Expression of HNF-1-beta was analyzed immunohistochemically in 320 cases including both tumor and non-tumor endometrial lesions. Promoter methylation and genetic variants were evaluated, using bisulphite and direct sequencing, in 30 (18 fresh frozen, 12 FFPE tumors) endometrioid carcinomas (ECs) and 15 ovarian clear cell carcinomas (OCCCs) as a control group. We detected expression of HNF-1-beta in 28 % of ECs (51/180 cases), 26 % of serous carcinoma (7/27 cases), 83 % of endometrial clear cell carcinoma (15/18 cases), 93 % of hyperplastic polyps with atypias (13/14 cases), 100 % of hyperplastic polyps without atypias (16/16 cases), 88 % of hyperplasias with atypias (14/16 cases), 91 % of hyperplasias without atypias (10/11 cases), and in ≥80 % of different normal endometrium samples. The control group of OCCCs showed HNF-1-beta expression in 95 % (18/19 cases). Methylation in promoter region was detected in 13.3 % (4/30) of ECs, but not in corresponding normal tissue where available, nor in OCCCs (0/15 cases). Mutation analysis revealed truncating variant c.454C > T (p.Gln152X) in one EC and missense variant c.848C > T (p.Ala283Val) was detected in one OCCC. In conclusion, expression of HNF-1-beta was detected in various extents in all types of lesions analyzed, nevertheless its strong expression was mostly limited to clear cell carcinomas. Biological significance of genetic and epigenetic changes needs further investigation.

Chemoresistance to platinum-based antineoplastic agents is a consistent feature among ovarian carcinomas; however, whereas high-grade serous carcinoma (OSC) acquires resistance during chemotherapy, ovarian clear cell carcinoma (OCCC) is intrinsically resistant. The main objective of this study was to explore, in vitro and in vivo, if hepatocyte nuclear factor 1β (HNF1β) and glutaminolysis contribute for the resistance of OCCC to carboplatin through the intrinsically increased GSH bioavailability. To disclose the role of HNF1β, experiments were also performed in an OSC cell line, which does not express HNF1β. Metabolic profiles, GSH quantification, HNF1β, and γ-glutamylcysteine ligase catalytic subunit (GCLC) and modifier subunit (GCLM) expression, cell cycle, and death were assessed in ES2 cell line (OCCC) and OVCAR3 cell line (OSC); HNF1β knockdown was performed in ES2 and murine model of subcutaneous and peritoneal OCCC tumors was established to test buthionine sulphoxamine (BSO), as a sensitizer to carboplatin. Glutaminolysis is activated in ES2 and OVCAR3, though ES2 exclusively synthesizes amino acids and GSH. ES2 cells are more resistant to carboplatin than OVCAR3 and the abrogation of GSH production by BSO sensitizes ES2 to carboplatin. HNF1β regulates the expression of GCLC, but not GCLM, and consequently GSH production in ES2. In vivo, BSO prior to carboplatin reduces dramatically subcutaneous tumor size and GSH levels, as well as peritoneal dissemination. Our study discloses HNF1β as the mediator of intrinsic OCCC chemoresistance and sheds a light to re-explore a cancer adjuvant therapeutic approach using BSO to overcome the lack of efficient therapy in OCCC.

Accurate distinction of clear cell carcinoma (CCC) from endometrioid carcinoma (EC) has important clinical implications, but, not infrequently, EC demonstrates clear cell change (EC-CC), mimicking CCC. We examined whether a panel of immunomarkers can help distinguish between these tumors. Sixty-four CCCs (40 ovarian and 24 uterine), 34 ECs (21 ovarian and 13 uterine), and 34 EC-CCs (6 ovarian and 28 uterine) were stained for HNF1β, BAF250a, Napsin A, ER, and PR. Intensity and extent of immunoreactivity was assessed. Fifty-seven of 64 (89%) CCCs, 14/34 (41%) EC-CCs, and 16/34 (47%) ECs expressed HNF1β, and 56/64 (88%) CCCs, 4/34 (12%) EC-CCs, and 1/34 (3%) ECs stained for Napsin A. Most CCCs demonstrated at least moderate and diffuse staining for both markers, whereas only focal and weak expression was identified in most EC-CC/EC. Compared to HNF1β, Napsin A showed increased specificity (93.0% vs. 55.9%, P

Hepatocyte nuclear factor-1β (HNF-1β) is a transcriptional factor that has an important role in endometriosis-ovarian clear cell carcinoma (OCCC) sequence by modulating cell kinetics and glucose metabolism. However, little is known about the detailed molecular mechanisms that govern its regulation and function. Herein, we focus on upstream and downstream regulatory factors of HNF-1β in OCCCs. In clinical samples, HNF-1β expression was positively correlated with the active form of NF-κB/p65 in OCCCs, and closely linked with a low nuclear grade and non-solid architecture. In cell lines, transfection of p65 resulted in increased HNF-1β mRNA and protein expression in TOV-21G cells (OCCC cell line with endogenous HNF-1β expression), in line with activation of the promoter, probably through interacting with the basic transcriptional machinery. Suppression of endogenous HNF-1β expression by siRNA increased apoptosis in TOV-21G cells, while treatment of Hec251 cells (endometrial carcinoma cell line with extremely low endogenous HNF-1β expression) stably overexpressing exogenous HNF-1β with doxorubicin abrogated apoptosis of the cells, along with increased ratio of bcl-2 relative to bax. Moreover, overexpression of HNF-1β led to upregulation of bcl-2 expression at the transcriptional level in TOV-21G cells, which provided evidence for a positive correlation between HNF-1β and bcl-2 expression in OCCCs. These data, therefore, suggest that association between HNF-1β and NF-κB signaling may participate in cell survival by alteration of apoptotic events, particularly in mitochondria-mediated pathways, through upregulation of bcl-2 expression in OCCCs.

Mutations in HNF1B, the gene encoding hepatocyte nuclear factor 1β are the most commonly identified genetic cause of renal malformations. HNF1B was first identified as a disease gene for diabetes (MODY5) in 1997, and its involvement in renal disease was subsequently noted through clinical observations in pedigrees affected by MODY5. Since then, a whole spectrum of associated phenotypes have been reported, including genital malformations, autism, epilepsy, gout, hypomagnesaemia, primary hyperparathyroidism, liver and intestinal abnormalities and a rare form of kidney cancer. The most commonly identified mutation, in approximately 50 % of patients, is an entire gene deletion occurring in the context of a 17q12 chromosomal microdeletion that also includes several other genes. Some of the associated phenotypes, especially the neurologic ones, appear to occur only in the context of this microdeletion and thus may not be directly linked to HNF1B. Here we review the spectrum of associated phenotypes and discuss potential implications for clinical management.

All-trans-retinoic acid (ATRA) is an active vitamin A derivative known to modulate a number of physiological processes, including growth and development, differentiation, and gene transcription. The protective effect of ATRA in gut inflammation and diarrheal diseases has been documented. In this regard, down-regulated in adenoma (DRA, a key luminal membrane Cl(-) transporter involved in NaCl absorption) has been shown to be suppressed in intestinal inflammation. This suppression of DRA is associated with diarrheal phenotype. Therefore, current studies were undertaken to examine the effects of ATRA on DRA expression. DRA mRNA levels were significantly elevated (∼4-fold) in response to ATRA with induction starting as early as 8 h of incubation. Similarly, ATRA increased DRA protein expression by ∼50%. Furthermore, DRA promoter activity was significantly increased in response to ATRA indicating transcriptional activation. ATRA effects on DRA expression appeared to be mediated via the RAR-β receptor subtype, as ATRA remarkably induced RAR-β mRNA levels, whereas RAR-β knockdown substantially attenuated the ability of ATRA to increase DRA expression. Results obtained from agonist (CH-55) and antagonist (LE-135) studies further confirmed that ATRA exerts its effects through RAR-β. Furthermore, ATRA treatment resulted in a significant increase in HNF-1β mRNA levels. The ability of ATRA to induce DRA expression was inhibited in the presence of HNF-1β siRNA indicative of its involvement in ATRA-induced effects on DRA expression. In conclusion, ATRA may act as an antidiarrheal agent by increasing DRA expression via the RAR-β/HNF-1β-dependent pathway.

Introduction: Hepatocyte transforming factor 1B-maturity onset diabetes mellitus of the young ( HNF1B -MODY) is an autosomal dominant type of monogenic diabetes caused by a mutation in the gene encoding hepatocyte nuclear factor 1beta (HNF-1beta). The aim of this study was to determine if a HNF1B gene mutation was responsible for a dominantly inherited form of diabetes mellitus among the members of a three-generation Polish family. Material and methods: The index subject was a 13-year-old boy with metabolic syndrome, spina bifida occulta, posterior urethral valves, congenital ureteropelvic junction obstruction, and a family history of diabetes of autosomal dominant trait of inheritance. We performed clinical and laboratory examinations of his family and sequenced the HNF1B gene. Results: A novel Q248X mutation (nucleotide C to T transition at position 742 of the exon 3 of HNF1B gene, resulting in stop codon formation) was identified. Phenotypes of family members sharing this mutation are highly variable, and include previously known abnormalities of the urinary system and pancreas, diabetes mellitus of variable onset and severity, hyperinsulinaemia, insulin resistance, metabolic syndrome, elevated aminotransferases, hyperbilirubinemia, hyperamylasemia, short stature and cataracts. To the best of our knowledge, spina bifida occulta, pectus carinatum, and splenomegaly have not been previously reported. Conclusions: Our results broaden the spectrum of HNF1B gene mutations and HNF1B -MODY-related phenotypes.

Napsin A and α-methylacyl-coenzyme A racemase (AMACR, P504S) have recently been described as being frequently expressed in clear cell carcinomas (CCC) of the gynecological tract. The present study was conducted to assess the test performance of these newer markers relative to the more traditional marker, hepatocyte nuclear factor 1β (HNF1β), in a large and histotypically diverse dataset. A total of 279 ovarian tumours in tissue microarrays were immunohistochemically assessed for the expression of Napsin A, AMACR and HNF1β. HNF1β, Napsin A and AMACR were expressed in 92%, 82% and 63% of 65 CCC, 7%, 1% and 1% of 101 serous carcinomas, 37%, 5.3% and 0% of 19 endometrioid carcinomas, 60%, 0% and 0% of 45 mucinous tumours, 100%, 0% and 0% of seven yolk sac tumours, and 0%, 16.7% and 16.7% of six steroid cell tumours NOS, respectively. All other tumours, including 18 adult-type granulosa cell tumours, eight dysgerminomas and nine other miscellaneous tumour types were negative for all three markers. Using a benchmark of ≥1% of tumour cells for positivity and CCC as the diagnostic end-point, the sensitivity, specificity, negative predictive value and positive predictive value of Napsin A expression were 0.82, 0.99, 0.94, and 0.98, respectively (odds ratio 439, p 0.0001). Respective parameters were 0.92, 0.79, 0.97, and 0.58 (odds ratio 44, p 0.0001) for HNF1β and 0.63, 0.99, 0.89, and 0.5 (odds ratio 112, p 0.0001) for AMACR. The combination of any two positive markers, irrespective of the staining pattern of the third, significantly predicted the CCC histotype in every analytic scenario. In summary, HNF1β is highly sensitive but is suboptimally specific in isolation, whereas AMACR is highly specific but is suboptimally sensitive. Napsin A is specific but of intermediate sensitivity. Napsin A, AMACR and HNF1β are all viable markers of CCC that can be deployed as components of larger panels when CCC is a diagnostic consideration.

Background: Autosomal dominant tubulointerstitial kidney disease subtype HNF1B (ADTKD-HNF1B) is caused by a mutation in hepatocyte nuclear factor 1 homeobox beta (HNF1B). Although 50-60% of ADTKD-HNF1B patients develop hypomagnesemia, HNF1B mutations are mainly identified in patients with structural kidney defects or diabetes. Cases: The current case series describes 3 patients in whom hypomagnesemia proved to be the first clinical manifestation of ADTKD-HNF1B. All patients presented with hypomagnesemia with a high fractional excretion of Mg2+ and hypocalciuria. Exome sequencing performed for analysis of known and candidate hypomagnesaemia genes and subsequent multiplex ligation-dependent probe amplification analysis revealed a large deletion at the chromosome 17q12. Follow-up analysis showed increased blood glucose concentrations in all 3 patients and high hemoglobin A1c levels in 2 out of 3 patients, indicating diabetes mellitus. Although all patients suffered from mild renal insufficiency, only 1 of the 3 patients was shown to have renal cysts on CT. Conclusion: The prevalence of HNF1B mutations and the relative contribution of hypomagnesemia to its symptoms are underestimated. Therefore, patients with primary renal magnesium wasting should be tested for HNF1B mutations to ensure early detection and optimal management of ADTKD-HNF1B.

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Objective Homozygous loss-of-function mutations in the gene coding for the homeobox transcription factor (TF) PDX1 leads to pancreatic agenesis, whereas heterozygous mutations can cause Maturity-Onset Diabetes of the Young 4 (MODY4). Although the function of Pdx1 is well studied in pre-clinical models during insulin-producing β-cell development and homeostasis, it remains elusive how this TF controls human pancreas development by regulating a downstream transcriptional program. Also, comparative studies of PDX1 binding patterns in pancreatic progenitors and adult β-cells have not been conducted so far. Furthermore, many studies reported the association between single nucleotide polymorphisms (SNPs) and T2DM, and it has been shown that islet enhancers are enriched in T2DM-associated SNPs. Whether regions, harboring T2DM-associated SNPs are PDX1 bound and active at the pancreatic progenitor stage has not been reported so far. Methods In this study, we have generated a novel induced pluripotent stem cell (iPSC) line that efficiently differentiates into human pancreatic progenitors (PPs). Furthermore, PDX1 and H3K27ac chromatin immunoprecipitation sequencing (ChIP-seq) was used to identify PDX1 transcriptional targets and active enhancer and promoter regions. To address potential differences in the function of PDX1 during development and adulthood, we compared PDX1 binding profiles from PPs and adult islets. Moreover, combining ChIP-seq and GWAS meta-analysis data we identified T2DM-associated SNPs in PDX1 binding sites and active chromatin regions. Results ChIP-seq for PDX1 revealed a total of 8088 PDX1-bound regions that map to 5664 genes in iPSC-derived PPs. The PDX1 target regions include important pancreatic TFs, such as PDX1 itself, RFX6, HNF1B, and MEIS1, which were activated during the differentiation process as revealed by the active chromatin mark H3K27ac and mRNA expression profiling, suggesting that auto-regulatory feedback regulation maintains PDX1 expression and initiates a pancreatic TF program. Remarkably, we identified several PDX1 target genes that have not been reported in the literature in human so far, including RFX3, required for ciliogenesis and endocrine differentiation in mouse, and the ligand of the Notch receptor DLL1, which is important for endocrine induction and tip-trunk patterning. The comparison of PDX1 profiles from PPs and adult human islets identified sets of stage-specific target genes, associated with early pancreas development and adult β-cell function, respectively. Furthermore, we found an enrichment of T2DM-associated SNPs in active chromatin regions from iPSC-derived PPs. Two of these SNPs fall into PDX1 occupied sites that are located in the intronic regions of TCF7L2 and HNF1B. Both of these genes are key transcriptional regulators of endocrine induction and mutations in cis-regulatory regions predispose to diabetes. Conclusions Our data provide stage-specific target genes of PDX1 during in vitro differentiation of stem cells into pancreatic progenitors that could be useful to identify pathways and molecular targets that predispose for diabetes. In addition, we show that T2DM-associated SNPs are enriched in active chromatin regions at the pancreatic progenitor stage, suggesting that the susceptibility to T2DM might originate from imperfect execution of a β-cell developmental program., Highlights • PDX1 ChIP-seq analysis revealed 5664 target genes in human pancreatic progenitors, including unreported target genes. • Comparison of PDX1 profiles from PPs and adult human islets identified stage-specific PDX1 target gene sets. • T2DM-associated SNPs are enriched in active chromatin regions from iPSC-derived PPs. • Three SNPs fall into PDX1 occupied sites, located in intronic regions of the developmental regulatory TFs TCF7L2 and HNF1B.

Retinoic acid (RA) is required for pancreas specification in Xenopus and other vertebrates. However, the gene network that is directly induced by RA signalling in this context remains to be defined. By RNA sequencing of in vitro-generated pancreatic explants, we identified the genes encoding the transcription factor Hnf1β and the Wnt-receptor Fzd4/Fzd4s as direct RA target genes. Functional analyses of Hnf1b and Fzd4/Fzd4s in programmed pancreatic explants and whole embryos revealed their requirement for pancreatic progenitor formation and differentiation. Thus, Hnf1β and Fzd4/Fzd4s appear to be involved in pre-patterning events of the embryonic endoderm that allow pancreas formation in Xenopus., Summary: The direct RA target genes Hnf1b and Fzd4 act as mediators of RA function in the pre-patterning of the dorsal endoderm during Xenopus gastrulation, resulting in pancreas specification in this context.

Hepatocyte nuclear factor-1beta plays an important role in the development and progression of liver cancer. In recent years, the expression of HNF-1β has been reported to be associated with risk for a variety of cancers. The purpose of this study is to investigate whether the expression of HNF-1β promotes the malignancy of HCC and its mechanism. We retrospectively investigated the expression of HNF-1β in 90 patients with hepatocellular carcinoma and found that the high expression of HNF-1β indicated poor prognosis. We overexpressed HNF-1β in liver cancer cell lines and found the expression of liver progenitor cell markers and stemness were upregulated. The invasion ability and epithelial-mesenchymal transition (EMT)-associated genes were also significantly higher in liver cancer cells overexpressing HNF-1β than in the control group. A mechanistic study suggested the activation of the Notch signalling pathway probably plays a key role downstream of HNF-1β. More importantly, HNF-1β promoted tumourigenesis of HCC cells in vivo. In conclusion, high expression of HNF-1β not only promoted the de-differentiation of HCC cells into liver cancer stem cells through activating the Notch pathway but also enhanced the invasive potential of HCC cells and EMT occurrence, which would contribute to the enhancement of cell migration and invasion.

The 17q12 chromosomal region carries the HNF1B gene, mutations of which cause various conditions. When searching for HNF1B/17q12 rearrangements among children with biliary atresia and/or choledochal cysts, we identified a male proband carrying a 17q12 duplication spanning 1698 kb that included 24 genes from TBC1D3C to HNF1B. The boy presented with cholestatic jaundice at the age of 2 weeks due to a choledochal cyst sized 15 ×12 mm (type Ia according to the Todani classification). He underwent a shunt surgery consisting of a hepaticojejunostomy using Roux-en-Y loop at the age of 2 months, which led to a permanent relief of cholestasis. Perioperative liver histology revealed significant hepatic fibrosis and bile ductular proliferation. At 17 years, he has a mildly enlarged liver with decreased elasticity, an upper-normal-sized spleen, normal biochemistry values, and no renal or hepatic cysts. We report the first hepatobiliary phenotype in a patient with an HNF1B overdosage.

Context: The clinical spectrum of organogenetic anomalies associated with HNF1B mutations is heterogeneous. Besides cystic kidney disease, diabetes, and various other manifestations, odd cases of mainly neonatal and posttransplantation cholestasis have been described. The biliary phenotype is incompletely defined. Objective: To systematically characterize HNF1B-related anomalies in the bile ducts by imaging with magnetic resonance imaging (MRI) or magnetic resonance cholangiopancreatography (MRCP). Setting and Patients: Fourteen patients with HNF1B mutations in the catchment area of the Helsinki University Hospital were evaluated with upper abdominal MRI and MRCP. Blood samples and clinical history provided supplemental data on the individual phenotype. Main Outcome Measure(s): Structural anomalies in the biliary system, medical history of cholestasis, other findings in abdominal organs, diabetes and antihyperglycemic treatment, hypomagnesemia, and hyperuricemia. Results: Structural anomalies of the bile ducts were found in seven of 14 patients (50%). Six patients had choledochal cysts, which are generally considered premalignant. Conclusions: Structural anomalies of the biliary system were common in HNF1B mutation carriers. The malignant potential of HNF1B-associated choledochal cysts warrants further studies.

Background: Few genetic studies have focused on unilateral renal agenesis (URA), which is a disorder with insidious clinical manifestations and a tendency to result in renal failure. We aimed to detect pathogenic mutations in nephrogenesis-related genes, which were identified by a literature review conducted among a large cohort of Chinese Han patients with URA. Methods: Totally, 86 unrelated URA patients were included. All URA patients were diagnosed by employing radiological methods. Patients with a solitary kidney owing to nephrectomy or renal atrophy due to secondary factors were excluded. Nine (10.5%) patients had a family history of abnormal nephrogenesis. Fifteen (17.4%) had other malformations in the urogenital system. All coding exons and adjacent intron regions of 25 genes were analyzed using next-generation sequencing and validated by Sanger sequencing and 100 ethnically matched healthy controls. Results: Ten conserved mutations (9 missense mutations and 1 deletion mutation) were identified in SALL1, EYA1, RET, HNF1B, DSTYK, WNT4, and SIX5. All mutations were novel or rare (frequency DSTYK. Conclusion: A total of 10.5% of our URA cases could be explained by mutations in our candidate genes. The mutations in nephrogenesis-related genes in the Chinese Han patients with URA had a decentralized distribution without any hotspot mutations.

Transcription factors are the major gene-regulatory proteins that recognize specific nucleotide sequences and bind to them. Missense mutations in transcription factors play a significant role in misregulation of gene expression contributing to various diseases and disorders. Understanding their structural and functional impact of the disease-causing mutations becomes prime importance in treating a disease. Commonly associated defect with the mutations of hepatocyte nuclear factor 1 beta (HNF1B) protein, a transcription factor results in maturity-onset diabetes of the young-5 (MODY-5) leading to loss of function. In the study presented, we applied a series of computational strategies to analyze the effect of mutations on protein structure or function in protein-DNA complex. The mutations from publicly available databases were retrieved and subjected to an array of in silico prediction methods. Key implementation of the present study consists of a pipeline drawn using well established in silico prediction methods of different algorithms to explain the biochemical changes impaired upon mutations in the binding sites of protein-DNA complex using HNF1B. Prediction scores obtained from the in silico tools suggested H153N and A241T as the major nsSNPs involved in destabilizing the protein. Further, high-end microscopic computational study, such as molecular dynamics simulations was utilized to relate the structural and functional effects upon mutations. Although, both the mutations exhibited similar structural differences, we observed A241T with higher destabilizing effect on the protein. The presented work is a step toward understanding the genotype-phenotype relationships in transcription factor genes using fast and accurate computational approach.

Background Circular RNAs are a subgroup of non-coding RNAs and generated by a mammalian genome. Herein, the expression and function of circular RNA circ-TTBK2 were investigated in human glioma cells. Methods Fluorescence in situ hybridization and quantitative real-time PCR were conducted to profile the cell distribution and expression of circ-TTBK2 and microRNA-217 (miR-217) in glioma tissues and cells. Immunohistochemical and western blot were used to determine the expression of HNF1β and Derlin-1 in glioma tissues and cells. Stable knockdown of circ-TTBK2 or overexpression of miR-217 glioma cell lines (U87 and U251) were established to explore the function of circ-TTBK2 and miR-217 in glioma cells. Further, luciferase reports and RNA immunoprecipitation were used to investigate the correlation between circ-TTBK2 and miR-217. Cell Counting Kit-8, transwell assays, and flow cytometry were used to investigate circ-TTBK2 and miR-217 function including cell proliferation, migration and invasion, and apoptosis, respectively. ChIP assays were used to ascertain the correlations between HNF1β and Derlin-1. Results We found that circ-TTBK2 was upregulated in glioma tissues and cell lines, while linear TTBK2 was not dysregulated in glioma tissues and cells. Enhanced expression of circ-TTBK2 promoted cell proliferation, migration, and invasion, while inhibited apoptosis. MiR-217 was downregulated in glioma tissues and cell lines. We also found that circ-TTBK2, but not linear TTBK2, acted as miR-217 sponge in a sequence-specific manner. In addition, upregulated circ-TTBK2 decreased miR-217 expression and there was a reciprocal negative feedback between them in an Argonaute2-dependent manner. Moreover, reintroduction of miR-217 significantly reversed circ-TTBK2-mediated promotion of glioma progression. HNF1β was a direct target of miR-217, and played oncogenic role in glioma cells. Remarkably, circ-TTBK2 knockdown combined with miR-217 overexpression led to tumor regression in vivo. Conclusions These results demonstrated a novel role circ-TTBK2 in the glioma progression. Electronic supplementary material The online version of this article (doi:10.1186/s13045-017-0422-2) contains supplementary material, which is available to authorized users.

Polychlorinated biphenyls (PCB) is a major type of persistent organic pollutants (POPs) that act as endocrine-disrupting chemicals. In the current study, we examined the mechanism underlying the effect of PCB-153 on glucose and lipid metabolism in vivo and in vitro. We found that PCB-153 induced per se and worsened high fat diet (HFD)-resulted increase of blood glucose level and glucose and insulin intolerance. In addition, PCB-153 induced per se and worsened HFD-resulted increase of triglyceride content and adipose mass. Moreover, PCB-153 concentration-dependently inhibited insulin-dependent glucose uptake and lipid accumulation in cultured hepatocytes and adipocytes. PCB-153 induced the expression and nuclear translocation of p65 NF-κB and the expression of its downstream inflammatory markers, and worsened HFD-resulted increase of those inflammatory markers. Inhibition of NF-κB significantly suppressed PCB-153-induced inflammation, lipid accumulation and decrease of glucose uptake. PCB-153 induced oxidative stress and decreased hepatocyte nuclear factor 1b (HNF1b) and glutathione peroxidase 1 (GPx1) expression in vivo and in vitro. Overexpression of HNF1b increased GPx1 expression, decreased ROS level, decreased Srebp1, ACC and FAS expression, and inhibited PCB-153-resulted oxidative stress, NF-κB-mediated inflammation, and final glucose/lipid metabolic disorder. Our results suggest that dysregulation of HNF1b/ROS/NF-κB plays an important role in PCB-153-induced glucose/lipid metabolic disorder. Keywords: Polychlorinated biphenyls, Glucose and lipid metabolic disorder, Hepatocyte nuclear factor 1b, Reactive oxygen species, NF-κB

Diabetes & Metabolism - In Press.Proof corrected by the author Available online since jeudi 10 novembre 2016

Objective To study the genetic cause of Mayer-Rokitansky-Kuster-Hauser syndrome (MRKH). Although a few candidate genes and genomic domains for have been reported for MRKH, the genetic underpinnings remain largely unknown. Some of the top candidate genes are WNT4 , HNF1B , and LHX1 . The goals of this study were to: 1) determine the prevalence of WNT4 , HNF1B , and LHX1 point mutations, as well as new copy number variants (CNVs) in people with MRKH; and 2) identify and characterize MRKH cohorts. Design Laboratory- and community-based study. Setting Academic medical centers. Patient(s) A total of 147 MRKH probands and available family members. Interventions(s) DNA sequencing of WNT4 , HNF1B , and LHX1 in 100 MRKH patients, chromosomal microarray analysis in 31 North American MRKH patients, and characterization and sample collection of 147 North American and Turkish MRKH probands and their families. Main Outcome Measure(s) DNA sequence variants and CNVs; pedigree structural analysis. Result(s) We report finding CNVs in 6/31 people (∼19%) with MRKH, but no point mutations or small indels in WNT4 , HNF1B , or LHX1 in 100 MRKH patients. Our MRKH families included 43 quads, 26 trios, and 30 duos. Of our MRKH probands, 87/147 (59%) had MRKH type 1 and 60/147 (41%) had type 2 with additional anomalies. Conclusion(s) Although the prevalence of WNT4 , HNF1B , and LHX1 point mutations is low in people with MRKH, the prevalence of CNVs was ∼19%. Further analysis of our large familial cohort of patients will facilitate gene discovery to better understand the complex etiology of MRKH.

Background Dyslipidemia during pregnancy increase the risk of pregnancy complications. Lipid profiles has strong genetic determinant and numerous susceptibility loci has been identified. However, very few studies focused on the association of lipid-related loci and maternal serum lipids during pregnancy. We, for the first time, investigated the association of common variants in three MODY genes (HNF1A, HNF4A and HNF1B) with serum lipid concentrations and glucose metabolism related quantitative traits in the second trimester of pregnancy. Methods A total of 1797 unrelated Han Chinese pregnant women were included. Three variants in 3’UTR were selected and genotyped using the TaqMan allelic discrimination assays. Multiple linear regression adjusted for age and BMI was applied for analysis. Results We found that T allele of rs1169309 in MODY3-HNF1A gene was significantly associated with increased levels of total cholesterol [B 0.123(0.057,0.189); P = 2.7 × 10-4] and LDL-c [B 0.075(0.018,0.132); P = 1.0 × 10-2]. Rs1169309-TT genotype carriers exhibited with higher levels of ApoA1 (P = 4.2 × 10-2) and ApoB (P = 6.0 × 10-3). In addition, the correlations between minor C allele of HNF1B-rs2688 and decreased levels of HOMA-B (P = 1.4 × 10-2), fasting insulin (P = 2.7 × 10-2) and HOMA-IR (P = 3.8 × 10-2) were identified. The minor C allele of HNF4A-rs6130615 was marginally associated with decreased fasting insulin levels (P = 0.050) and HOMA-IR (P = 0.048). Conclusions Variants in MODY genes played critical role in lipid and glucose homeostasis. Future studies will be required to further clarify the molecular mechanisms underlying these observed associations.

Transcription factors are the major gene-regulatory proteins that recognize specific nucleotide sequences and bind to them. Missense mutations in transcription factors play a significant role in misregulation of gene expression contributing to various diseases and disorders. Understanding their structural and functional impact of the disease-causing mutations becomes prime importance in treating a disease. Commonly associated defect with the mutations of hepatocyte nuclear factor 1 beta (HNF1B) protein, a transcription factor results in maturity-onset diabetes of the young-5 (MODY-5) leading to loss of function. In the study presented, we applied a series of computational strategies to analyze the effect of mutations on protein structure or function in protein–DNA complex. The mutations from publicly available databases were retrieved and subjected to an array of in silico prediction methods. Key implementation of the present study consists of a pipeline drawn using well established in silico prediction methods of different algorithms to explain the biochemical changes impaired upon mutations in the binding sites of protein–DNA complex using HNF1B. Prediction scores obtained from the in silico tools suggested H153N and A241T as the major nsSNPs involved in destabilizing the protein. Further, high-end microscopic computational study, such as molecular dynamics simulations was utilized to relate the structural and functional effects upon mutations. Although, both the mutations exhibited similar structural differences, we observed A241T with higher destabilizing effect on the protein. The presented work is a step toward understanding the genotype–phenotype relationships in transcription factor genes using fast and accurate computational approach.

Hepatocyte nuclear factor 1 homeobox B (HNF1β) is an essential transcription factor for the development and functioning of the kidney. Mutations in HNF1β cause autosomal dominant tubulointerstitial kidney disease characterized by renal cysts and maturity-onset diabetes of the young (MODY). Moreover, these patients suffer from a severe electrolyte phenotype consisting of hypomagnesemia and hypokalemia. Until now, genes that are regulated by HNF1β are only partially known and do not fully explain the phenotype of the patients. Therefore, we performed chIP-seq in the immortalized mouse kidney cell line mpkDCT to identify HNF1β binding sites on a genome-wide scale. In total 7,421 HNF1β-binding sites were identified, including several genes involved in electrolyte transport and diabetes. A highly specific and conserved HNF1β site was identified in the promoter of Kcnj16 that encodes the potassium channel Kir5.1. Luciferase-promoter assays showed a 2.2-fold increase in Kcnj16 expression when HNF1β was present. Expression of the Hnf1β p.Lys156Glu mutant, previously identified in a patient with autosomal dominant tubulointerstitial kidney disease, did not activate Kcnj16 expression. Knockdown of Hnf1 β in mpkDCT cells significantly reduced the appearance of Kcnj16 (Kir5.1) and Kcnj10 (Kir4.1) by 38% and 37%, respectively. These results were confirmed in a HNF1β renal knockout mouse which exhibited downregulation of Kcnj16 , Kcnj10 and Slc12a3 transcripts in the kidney by 78%, 83% and 76%, respectively, compared to HNF1β wild-type mice. Thus, HNF1β is a transcriptional activator of Kcnj16 . Hence, patients with HNF1 β mutations may have reduced Kir5.1 activity in the kidney, resulting in hypokalemia and hypomagnesemia.

Notch signaling plays important roles during mammalian nephrogenesis. To investigate if Notch regulates nephron segmentation, we performed Notch loss-of-function and gain-of-function studies in developing nephrons in mice. Contrary to the previous notion that Notch signaling promotes the formation of proximal tubules and represses the formation of distal tubules in the mammalian nephron, we show that inhibition of Notch blocks the formation of all nephron segments and that constitutive activation of Notch in developing nephrons does not promote or repress the formation of a specific segment. Cells lacking Notch fail to form the S-shaped body and show reduced expression of Lhx1 and Hnf1b. Consistent with this, we find that constitutive activation of Notch in mesenchymal nephron progenitors causes ectopic expression of Lhx1 and Hnf1b and that these cells eventually form a heterogeneous population of cells including proximal tubules and other types of cells. Our data suggest that Notch signaling is required for the formation of all nephron segments and that Notch signaling primes nephron progenitors for differentiation rather than directing their cell fates into a specific nephron segment.

Kidney development depends critically on proper ureteric bud branching giving rise to the entire collecting duct system. The transcription factor HNF1B is required for the early steps of ureteric bud branching. Yet, the molecular and cellular events regulated by HNF1B are poorly understood. We report that specific removal of Hnf1b from the ureteric bud leads to defective cell-cell contacts and apico-basal polarity during the early branching events. High resolution ex vivo imaging combined with a membranous fluorescent reporter strategy show decreased mutant cell-rearrangements during mitosis-associated cell dispersal and severe epithelial disorganisation. Molecular analysis reveals downregulation of Gdnf-Ret pathway components and suggests that HNF1B acts both upstream and downstream of Ret-signaling by directly regulating Gfrα1 and Etv5.Subsequently, Hnf1b-deletion leads to massively mispatterned ureteric tree network, defective collecting duct differentiation and disrupted tissue architecture leading to cystogenesis. Consistently, mRNA-seq analysis shows that the most impacted genes encode intrinsic cell-membrane components with transporter activity. Our study uncovers a fundamental and recurrring role of HNF1B in epithelial organization during early ureteric bud branching and further patterning and differentiation of the collecting duct system.

Purpose: To investigate genes involved in pancreatic beta cell function, insulin production and glucose metabolism that may predispose to gestational diabetes mellitus (GDM). Methods: The study group consisted of 204 women with GDM and 207 women with normal glucose tolerance (NGT). The following polymorphisms were genotyped for each patient: HNF1B rs4430796, TSPAN8 rs7961581 and NOTCH2 rs10923931. A p value of Results: There was a statistically significant increase in the frequency of HNF1B rs4430796 G allele among pregnant women with GDM (GG+AG versus AA, OR: 1.55, 95% CI: 1.01–2.36, p = .042; G versus A, OR: 1.39, 95% CI: 1.06–1.83, p = .018), whereas there were no statistically significant differences in the distributions of TSPAN8 rs7961581 and NOTCH2 rs10923931 genotypes and alleles between women with GDM and healthy pregnant women. In the multivariate logistic regression analysis, older age, higher BMI before pregnancy and a higher number of HNF1B rs4430796 G alleles were independent significant predictors of a higher risk of GDM. Conclusions: The results of this study suggest that the HNF1B gene rs4430796 G allele may be associated with increased risk of GDM.

Heterozygous mutations in the gene that encodes the transcription factor hepatocyte nuclear factor 1β (HNF1B) represent the most common known monogenic cause of developmental kidney disease. Renal cysts are the most frequently detected feature of HNF1B-associated kidney disease; however, other structural abnormalities, including single kidneys and renal hypoplasia, and electrolyte abnormalities can also occur. Extra-renal phenotypes might also be observed; consequently, HNF1B-associated disease is considered a multi-system disorder. Other clinical features include early-onset diabetes mellitus, pancreatic hypoplasia, genital tract malformations, abnormal liver function and early-onset gout. Heterozygous mutations in the coding region or splice sites of HNF1B, and complete gene deletion, each account for ∼50% of all cases of HNF1B-associated disease, respectively, and often arise spontaneously. There is no clear genotype-phenotype correlation, consistent with haploinsufficiency as the disease mechanism. Data from animal models suggest that HNF1B has an important function during several stages of nephrogenesis; however, the precise signalling pathways remain to be elucidated. This Review discusses the genetics and molecular pathways that lead to disease development, summarizes the reported renal and extra-renal phenotypes, and identifies areas for future research in HNF1B-associated disease.

Objective The objective of this study was to characterize the genetic abnormalities in two fetuses with congenital anomalies in prenatal screening. Materials and methods The mother of Fetus 1 was 26 years old and had a second trimester serum screening that indicated the fetus was at low risk. The prenatal ultrasound and magnetic resonance imaging (MRI) at 28 weeks of gestation showed mild ventriculomegaly, microcephaly, and agenesis of the corpus callosum. The mother of Fetus 2 was 25 years old and also had a second trimester serum screening that indicated the fetus was at low risk. The prenatal ultrasound at 32 weeks of gestation showed the presence of hyperechogenic and enlarged kidneys with multicystic renal dysplasia bilaterally and a persistent left superior vena cava (PLSVC). Both pregnant women underwent cord blood samplings because of the abnormal imaging results. Karyotype analysis revealed normal results in the two fetuses. Chromosome microarray analysis (CMA) was then performed to provide genetic analysis of the cord blood and parental blood samples. Ultimately, the pregnancies were both terminated. Results CMA detected a 1.56-Mb duplication at 17q12 in Fetus 1 and a 1.93-Mb deletion of 17q12 in Fetus 2. Both the duplicated and deleted regions included the HNF1B and LHX1 genes. Neither the duplication nor deletion was inherited from the parents. Conclusion This study is the first to report the prenatal diagnosis of a 17q12 duplication syndrome. Our results further confirmed that genes in this region, including HNF1B and LHX1 , are essential for normal brain and kidney development, and also indicated some genes that may be associated with the cardiovascular abnormality. Combined with imaging examination, the use of CMA will improve the diagnosis of submicroscopic chromosomal aberrations in fetuses with congenital anomalies.