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11
result(s) for
"Johansson, Bente B."
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Targeted next-generation sequencing reveals MODY in up to 6.5% of antibody-negative diabetes cases listed in the Norwegian Childhood Diabetes Registry
by
Søvik, Oddmund
,
Juliusson, Petur B.
,
Joner, Geir
in
Adolescent
,
Antibodies
,
Antibodies - metabolism
2017
Aims/hypothesis
MODY can be wrongly diagnosed as type 1 diabetes in children. We aimed to find the prevalence of MODY in a nationwide population-based registry of childhood diabetes.
Methods
Using next-generation sequencing, we screened the
HNF1A
,
HNF4A
,
HNF1B
,
GCK
and
INS
genes in all 469 children (12.1%) negative for both GAD and IA-2 autoantibodies and 469 antibody-positive matched controls selected from the Norwegian Childhood Diabetes Registry (3882 children). Variants were classified using clinical diagnostic criteria for pathogenicity ranging from class 1 (neutral) to class 5 (pathogenic).
Results
We identified 58 rare exonic and splice variants in cases and controls. Among antibody-negative patients, 6.5% had genetic variants of classes 3–5 (vs 2.4% in controls;
p
= 0.002). For the stricter classification (classes 4 and 5), the corresponding number was 4.1% (vs 0.2% in controls;
p
= 1.6 × 10
−5
).
HNF1A
showed the strongest enrichment of class 3–5 variants, with 3.9% among antibody-negative patients (vs 0.4% in controls;
p
= 0.0002). Antibody-negative carriers of variants in class 3 had a similar phenotype to those carrying variants in classes 4 and 5.
Conclusions/interpretation
This is the first study screening for MODY in all antibody-negative children in a nationwide population-based registry. Our results suggest that the prevalence of MODY in antibody-negative childhood diabetes may reach 6.5%. One-third of these MODY cases had not been recognised by clinicians. Since a precise diagnosis is important for treatment and genetic counselling, molecular screening of all antibody-negative children should be considered in routine diagnostics.
Journal Article
A recombined allele of the lipase gene CEL and its pseudogene CELP confers susceptibility to chronic pancreatitis
2015
Anders Molven and colleagues show that a recombined allele of the lipase gene
CEL
and its pseudogene
CELP
confers susceptibility to chronic pancreatitis. The hybrid allele is associated with approximately fivefold-higher risk of disease, and it encodes a protein with reduced lipolytic activity and prominent intracellular accumulation.
Carboxyl ester lipase is a digestive pancreatic enzyme encoded by the
CEL
gene
1
. Mutations in
CEL
cause maturity-onset diabetes of the young as well as pancreatic exocrine dysfunction
2
. Here we describe a hybrid allele (
CEL-HYB
) originating from a crossover between
CEL
and its neighboring pseudogene,
CELP
. In a discovery series of familial chronic pancreatitis cases, we observed
CEL-HYB
in 14.1% (10/71) of cases compared to 1.0% (5/478) of controls (odds ratio (OR) = 15.5; 95% confidence interval (CI) = 5.1–46.9;
P
= 1.3 × 10
−6
by two-tailed Fisher's exact test). In three replication studies of nonalcoholic chronic pancreatitis, we identified
CEL-HYB
in a total of 3.7% (42/1,122) cases and 0.7% (30/4,152) controls (OR = 5.2; 95% CI = 3.2–8.5;
P
= 1.2 × 10
−11
; formal meta-analysis). The allele was also enriched in alcoholic chronic pancreatitis. Expression of CEL-HYB in cellular models showed reduced lipolytic activity, impaired secretion, prominent intracellular accumulation and induced autophagy. These findings implicate a new pathway distinct from the protease-antiprotease system of pancreatic acinar cells in chronic pancreatitis.
Journal Article
Characterization of the genetic architecture of infant and early childhood body mass index
by
Kjennerud, Ted Reichborn
,
Flatley, Christopher
,
Juliusson, Petur B.
in
45/43
,
631/208/205/2138
,
631/208/729
2022
Early childhood obesity is a growing global concern; however, the role of common genetic variation on infant and child weight development is unclear. Here, we identify 46 loci associated with early childhood body mass index at specific ages, matching different child growth phases, and representing four major trajectory patterns. We perform genome-wide association studies across 12 time points from birth to 8 years in 28,681 children and their parents (27,088 mothers and 26,239 fathers) in the Norwegian Mother, Father and Child Cohort Study. Monogenic obesity genes are overrepresented near identified loci, and several complex association signals near
LEPR
,
GLP1R
,
PCSK1
and
KLF14
point towards a major influence for common variation affecting the leptin–melanocortin system in early life, providing a link to putative treatment strategies. We also demonstrate how different polygenic risk scores transition from birth to adult profiles through early child growth. In conclusion, our results offer a fine-grained characterization of a changing genetic landscape sustaining early childhood growth.
Helgeland et al. characterize genetic loci associated with early childhood body mass index, highlighting roles of genes involved in monogenic obesity, appetite regulation and energy expenditure, many of which show age-specific association patterns.
Journal Article
Pathogenic Carboxyl Ester Lipase (CEL) Variants Interact with the Normal CEL Protein in Pancreatic Cells
by
Lavik, Ida K.
,
Gravdal, Anny
,
Lugea, Aurelia
in
Acinar cells
,
Acinar Cells - metabolism
,
Antibodies
2020
Mutations in the gene encoding the digestive enzyme carboxyl ester lipase (CEL) are linked to pancreatic disease. The CEL variant denoted CEL-HYB predisposes to chronic pancreatitis, whereas the CEL-MODY variant causes MODY8, an inherited disorder of endocrine and exocrine pancreatic dysfunction. Both pathogenic variants exhibit altered biochemical and cellular properties compared with the normal CEL protein (CEL-WT, wild type). We here aimed to investigate effects of CEL variants on pancreatic acinar and ductal cell lines. Following extracellular exposure, CEL-HYB, CEL-MODY, and CEL-WT were endocytosed. The two pathogenic CEL proteins significantly reduced cell viability compared with CEL-WT. We also found evidence of CEL uptake in primary human pancreatic acinar cells and in native ductal tissue. Moreover, coexpression of CEL-HYB or CEL-MODY with CEL-WT affected secretion of the latter, as CEL-WT was observed to accumulate intracellularly to a higher degree in the presence of either pathogenic variant. Notably, in coendocytosis experiments, both pathogenic variants displayed a modest effect on cell viability when CEL-WT was present, indicating that the normal protein might diminish toxic effects conferred by CEL-HYB and CEL-MODY. Taken together, our findings provide valuable insight into how the pathogenic CEL variants predispose to pancreatic disease and why these disorders develop slowly over time.
Journal Article
Characterisation of HNF1A variants in paediatric diabetes in Norway using functional and clinical investigations to unmask phenotype and monogenic diabetes
by
Valen, Eivind
,
Skrivarhaug, Torild
,
Bjørkhaug, Lise
in
Autoantibodies
,
Autoantibodies - genetics
,
Child
2023
Aims/hypothesis
Correctly diagnosing MODY is important, as individuals with this diagnosis can discontinue insulin injections; however, many people are misdiagnosed. We aimed to develop a robust approach for determining the pathogenicity of variants of uncertain significance in hepatocyte nuclear factor-1 alpha (HNF1A)
-
MODY and to obtain an accurate estimate of the prevalence of HNF1A-MODY in paediatric cases of diabetes.
Methods
We extended our previous screening of the Norwegian Childhood Diabetes Registry by 830 additional samples and comprehensively genotyped
HNF1A
variants in autoantibody-negative participants using next-generation sequencing. Carriers of pathogenic variants were treated by local healthcare providers, and participants with novel likely pathogenic variants and variants of uncertain significance were enrolled in an investigator-initiated, non-randomised, open-label pilot study (ClinicalTrials.gov registration no. NCT04239586). To identify variants associated with HNF1A-MODY, we functionally characterised their pathogenicity and assessed the carriers’ phenotype and treatment response to sulfonylurea.
Results
In total, 615 autoantibody-negative participants among 4712 cases of paediatric diabetes underwent genetic sequencing
,
revealing 19 with
HNF1A
variants. We identified nine carriers with novel variants classified as variants of uncertain significance or likely to be pathogenic, while the remaining ten participants carried five pathogenic variants previously reported. Of the nine carriers with novel variants, six responded favourably to sulfonylurea. Functional investigations revealed their variants to be dysfunctional and demonstrated a correlation with the resulting phenotype, providing evidence for reclassifying these variants as pathogenic.
Conclusions/interpretation
Based on this robust classification, we estimate that the prevalence of HNF1A-MODY is 0.3% in paediatric diabetes. Clinical phenotyping is challenging and functional investigations provide a strong complementary line of evidence. We demonstrate here that combining clinical phenotyping with functional protein studies provides a powerful tool to obtain a precise diagnosis of HNF1A-MODY.
Graphical Abstract
Journal Article
Abnormal exocrine–endocrine cell cross-talk promotes β-cell dysfunction and loss in MODY8
2022
MODY8 (maturity-onset diabetes of the young, type 8) is a dominantly inherited monogenic form of diabetes associated with mutations in the carboxyl ester lipase (
CEL
) gene expressed by pancreatic acinar cells. MODY8 patients develop childhood-onset exocrine pancreas dysfunction followed by diabetes during adulthood. However, it is unclear how
CEL
mutations cause diabetes. In the present study, we report the transfer of CEL proteins from acinar cells to β-cells as a form of cross-talk between exocrine and endocrine cells. Human β-cells show a relatively higher propensity for internalizing the mutant versus the wild-type CEL protein. After internalization, the mutant protein forms stable intracellular aggregates leading to β-cell secretory dysfunction. Analysis of pancreas sections from a MODY8 patient reveals the presence of CEL protein in the few extant β-cells. The present study provides compelling evidence for the mechanism by which a mutant gene expressed specifically in acinar cells promotes dysfunction and loss of β-cells to cause diabetes.
Kahraman et al. show that transfer of mutant CEL protein from pancreatic acinar cells to β cells causes β-cell dysfunction, providing insight into the mechanism underlying MODY8.
Journal Article
The position of single-base deletions in the VNTR sequence of the carboxyl ester lipase (CEL) gene determines pathogenicity
2020
ABSTRACT Variable number of tandem repeat (VNTR) sequences present in the genome can have functional consequences that contribute to human disease. This is the case for the CEL gene, which encodes the digestive enzyme carboxyl ester lipase. CEL has a VNTR located in exon 11, and rare single-base deletions (DELs) within this region cause MODY8, an inherited disorder characterized by exocrine pancreatic dysfunction and diabetes. Here, we have studied how the position of single-base deletions within the CEL VNTR affects the protein’s pathogenic properties. We investigated four naturally occurring CEL variants with single-base deletions in different VNTR segments (DEL1, DEL4, DEL9, DEL13), of which only DEL1 and DEL4 have been observed in MODY8 patients. When expressed in a cellular model system, only DEL1 and DEL4 exhibited significantly reduced secretion and increased intracellular aggregation compared to normal CEL. We found that all DEL variants had slightly decreased enzymatic activity and that their level of O-glycosylation was affected. Moreover, only DEL1 and DEL4 significantly increased endoplasmic reticulum (ER) stress. In conclusion, CEL single-base deletion variants have the highest pathogenic potential when the mutational event has taken place in the proximal VNTR part, resulting in the longest aberrant protein tails. Thus, DEL1 and DEL4 are pathogenic CEL variants, whereas we consider DEL13 as benign and DEL9 as likely benign. These findings have implications for our understanding of how CEL mutations cause pancreatic disease through protein misfolding and proteotoxicity, leading to ER stress and activation of the unfolded protein response.
An inverse association between plasma benzoxazinoid metabolites and PSA after rye intake in men with prostate cancer revealed with a new method
2022
Prostate cancer (PC) is a common cancer among men, and preventive strategies are warranted. Benzoxazinoids (BXs) in rye have shown potential against PC in vitro but human studies are lacking. The aim was to establish a quantitative method for analysis of BXs and investigate their plasma levels after a whole grain/bran rye vs refined wheat intervention, as well as exploring their association with PSA, in men with PC. A quantitative method for analysis of 22 BXs, including novel metabolites identified by mass spectrometry and NMR, was established, and applied to plasma samples from a randomized crossover study where patients with indolent PC (n = 17) consumed 485 g whole grain rye/rye bran or fiber supplemented refined wheat daily for 6 wk. Most BXs were significantly higher in plasma after rye (0.3–19.4 nmol/L in plasma) vs. refined wheat (0.05–2.9 nmol/L) intake. HBOA-glc, 2-HHPAA, HBOA-glcA, 2-HPAA-glcA were inversely correlated to PSA in plasma (
p
< 0.04). To conclude, BXs in plasma, including metabolites not previously analyzed, were quantified. BX metabolites were significantly higher after rye vs refined wheat consumption. Four BX-related metabolites were inversely associated with PSA, which merits further investigation.
Journal Article
Testosterone exacerbates neutrophilia and cardiac injury in myocardial infarction via actions in bone marrow
2025
Men develop larger infarct sizes than women after a myocardial infarction (MI), but the mechanism underlying this sex difference is unknown. Here, we demonstrated that blood neutrophil counts post-MI were higher in male than female mice. Castration-induced testosterone deficiency reduced blood neutrophil counts to the level in females and increased survival post-MI. These effects were mimicked by Osterix-directed ablation of the androgen receptor in bone marrow (BM). Mechanistically, androgens downregulated the leukocyte retention factor CXCL12 in BM stromal cells. Post-hoc analysis of clinical trial data showed that neutrophilia was greater in men than women after reperfusion of first-time ST-elevation MI, and tocilizumab, an interleukin-6 receptor inhibitor, reduced blood neutrophil counts and infarct size to a greater extent in men than women. Our work reveals a previously unknown mechanism connecting testosterone with neutrophilia and MI injury via BM and identifies the importance of considering sex when developing anti-inflammatory strategies to treat MI.
Men develop larger myocardial infarction (MI) sizes than women. Here, the authors show that male sex and testosterone, via bone marrow stroma, exacerbates MI-induced neutrophilia and cardiac injury and that response to anti-inflammatory treatment in MI is greater in men than women
Journal Article