Hepatocyte nuclear factor 1B mutation in a Chinese family with renal cysts and diabetes syndrome:A case report

BACKGROUND Renal cysts and diabetes(RCAD)syndrome is an autosomal dominant diabetic renal disease.Precise molecular diagnosis of RCAD syndrome has proven valuable for understanding its mechanism and personalized therapy.CASE SUMMARY A RCAD patient and her family were studied to investigate potential responsible genes by the whole exome sequencing(WES).Candidate pathogenic variants were validated by Sanger sequencing.The clinical characteristics of RCAD patient were collected from medical records.Unlike those typical RCAD patients,we observed renal manifestation and prediabetes phenotype,but not reproductive organ phenotype and hypomagnesaemia.A novel 7-bp deletion mutation in exon 4 of the hepatocyte nuclear factor 1B,NM_000458:c.882_888del(p.V294fs),was identified by WES and confirmed by Sanger sequencing.CONCLUSION This novel mutation identified in a Chinese family with RCAD syndrome might be the molecular pathogenic basis of this disorder.

转录因子HNF1A、HNF4A和FOXA2调节肝细胞蛋白质N-糖基化

Hepatocyte nuclear factor 1 alpha(HNF1A),hepatocyte nuclear factor 4 alpha(HNF4A),and forkhead box protein A2(FOXA2)are key transcription factors that regulate a complex gene network in the liver,cre-ating a regulatory transcriptional loop.The Encode and ChIP-Atlas databases identify the recognition sites of these transcription factors in many glycosyltransferase genes.Our in silico analysis of HNF1A,HNF4A.and FOXA2 binding to the ten candidate glyco-genes studied in this work confirms a significant enrich-ment of these transcription factors specifically in the liver.Our previous studies identified HNF1A as a master regulator of fucosylation,glycan branching,and galactosylation of plasma glycoproteins.Here,we aimed to functionally validate the role of the three transcription factors on downstream glyco-gene transcriptional expression and the possible effect on glycan phenotype.We used the state-of-the-art clus-tered regularly interspaced short palindromic repeats/dead Cas9(CRISPR/dCas9)molecular tool for the downregulation of the HNF1A,HNF4A,and FOXA2 genes in HepG2 cells-a human liver cancer cell line.The results show that the downregulation of all three genes individually and in pairs affects the transcrip-tional activity of many glyco-genes,although downregulation of glyco-genes was not always followed by an unambiguous change in the corresponding glycan structures.The effect is better seen as an overall change in the total HepG2 N-glycome,primarily due to the extension of biantennary glycans.We propose an alternative way to evaluate the N-glycome composition via estimating the overall complexity of the glycome by quantifying the number of monomers in each glycan structure.We also propose a model showing feedback loops with the mutual activation of HNF1A-FOXA2 and HNF4A-FOXA2 affecting glyco-genes and protein glycosylation in HepG2 cells.

Management of monogenic diabetes in pregnancy:A narrative review

Pregnancy in women with monogenic diabetes is potentially complex,with significant implications for both maternal and fetal health.Among these,maturity-onset diabetes of the young(MODY)stands out as a prevalent monogenic diabetes subtype frequently encountered in clinical practice.Each subtype of MODY requires a distinct approach tailored to the pregnancy,diverging from management strategies in non-pregnant individuals.Glucokinase MODY(GCK-MODY)typically does not require treatment outside of pregnancy,but special considerations arise when a woman with GCK-MODY becomes pregnant.The glycemic targets in GCK-MODY pregnancies are not exclusively dictated by the maternal/paternal MODY genotype but are also influenced by the genotype of the developing fetus.During pregnancy,the choice between sulfonylurea or insulin for treating hepatocyte nuclear factor 1-alpha(HNF1A)-MODY and HNF4A-MODY depends on the mother’s specific circumstances and the available expertise.Management of other rarer MODY subtypes is individu-alized,with decisions made on a case-by-case basis.Therefore,a collaborative approach involving expert diabetes and obstetric teams is crucial for the compre-hensive management of MODY pregnancies.

A Case Report of MODY_(3)Combined with Intestinal Neuroendocrine Tumor

Maturity-onset diabetes of the young 3(MODY_(3))is an autosomal dominant monogenic diabetes mellitus characterized by defective p-cell function and non-insulin-dependent early-onset diabetes mellitus.The facts that patients with MODY_(3) are often misdiagnosed as type 1 and type 2 diabetes mellitus and genetic diagnosis is expensive,make its diagnosis very challenging.In this study,we reported a case of MODY_(3),which was verified to be caused by a mutation in hepatocyte nuclear factor 1αgene(c.598C>X p.Arg200Trp).In addition,the patient had a neuroendocrine tumor simultaneously,and a KMT2D gene mutation(c.5587C>G,p.Prol863Ala)might be associated with this leson.

Sortilin-induced lipid accumulation and atherogenesis are suppressed by HNF1b SUMOylation promoted by flavone of Polygonatum odoratum

This study aims to investigate the impact of hepatocyte nuclear factor 1β(HNF1b)on macrophage sortilin-mediated lipid metabolism and aortic atherosclerosis and explore the role of the flavone of Polygonatum odoratum(PAOA-flavone)-promoted small ubiquitin-related modifier(SUMO)modification in the atheroprotective efficacy of HNF1b.HNF1b was predicted to be a transcriptional regulator of sortilin expression via bioinformatics,dual-luciferase reporter gene assay,and chromatin immunoprecipitation.HNF1b overexpression decreased sortilin expression and cellular lipid contents in THP-1 macrophages,leading to a depression in atherosclerotic plaque formation in low-density lipoprotein(LDL)receptor-deficient(LDLR−/−)mice.Multiple SUMO1-modified sites were identified on the HNF1b protein and co-immunoprecipitation confirmed its SUMO1 modification.The SUMOylation of HNF1b protein enhanced the HNF1b-inhibited effect on sortilin expression and reduced lipid contents in macrophages.PAOA-flavone treatment promoted SUMO-activating enzyme subunit 1(SAE1)expression and SAE1-catalyzed SUMOylation of the HNF1b protein,which prevented sortilin-mediated lipid accumulation in macrophages and the formation of atherosclerotic plaques in apolipoprotein E-deficient(ApoE−/−)mice.Interference with SAE1 abrogated the improvement in lipid metabolism in macrophage cells and atheroprotective efficacy in vivo upon PAOA-flavone administration.In summary,HNF1b transcriptionally suppressed sortilin expression and macrophage lipid accumulation to inhibit aortic lipid deposition and the development of atherosclerosis.This anti-atherosclerotic effect was enhanced by PAOA-flavone-facilitated,SAE1-catalyzed SUMOylation of the HNF1b protein.

Systematic review of TCF2 anomalies in renal cysts and diabetes syndrome/maturity onset diabetes of the young type 5

Objective There is a paucity of published works that systematically evaluate gene anomalies or clinical features of patients with renal cysts and diabetes syndrome （RCAD）/maturity onset diabetes of the young type 5 （MODY5）. The purpose of this review was to systematically assess the detection rate, genetic and phenotypic implications of heterozygous autosomal dominant TCF2 anomalies. Data sources MEDLINE database was searched to select articles recorded in English from 1997 to 2008. The focus was monoallelic germline TCF2 gene mutations/deletions. Biallelic inactivation, polymorphisms, DNA modification （hypomethylation and hypermethylation）, loci associated with cancer risk, and somatic TCF2 anomalies were all excluded. Study selection After searching the literature, 50 articles were selected. Results The detection rate of TCF2anomalies was 9.7% and varied considerably among MODY （1.4%）, renal structure anomalies （RSA） （21.4%） and RSA with MODY （41.2%） subgroups. Mutations were strikingly located within the DNA binding domain and varied among exons of the DNA binding domain： exons 2 and 4 were the hottest spots, while mutations were sporadically distributed in exon 3. The consistent phenotypes were RSA （89.6%） and diabetes mellitus （DM） （45.0%）. However, the concurrence of RSA and DM was relatively low （27.5%）, which hinders the optimal performance of genetic testing and obtainment of timely diagnosis. Other organ involvements were complementary and necessary for the early identification of patients with TCF2 anomalies. Analysis of phenotypes of TCF2 point mutations showed significant differences in the detection rates of RSA, impaired renal function （IRF） and DM according to mutation type but not mutation location. Conclusion These valuable features of TCF2 anomalies that previously did not receive sufficient attention should not be neglected.