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result(s) for
"Link, Jenny"
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X chromosome dosage of histone demethylase KDM5C determines sex differences in adiposity
by
Yao, Jie
,
Ronquillo, Emilio
,
Guo, Xiuqing
in
Adipocytes
,
Adipocytes - enzymology
,
Adipose tissue
2020
Males and females differ in body composition and fat distribution. Using a mouse model that segregates gonadal sex (ovaries and testes) from chromosomal sex (XX and XY), we showed that XX chromosome complement in combination with a high-fat diet led to enhanced weight gain in the presence of male or female gonads. We identified the genomic dosage of Kdm5c, an X chromosome gene that escapes X chromosome inactivation, as a determinant of the X chromosome effect on adiposity. Modulating Kdm5c gene dosage in XX female mice to levels that are normally present in males resulted in reduced body weight, fat content, and food intake to a degree similar to that seen with altering the entire X chromosome dosage. In cultured preadipocytes, the levels of KDM5C histone demethylase influenced chromatin accessibility (ATAC-Seq), gene expression (RNA-Seq), and adipocyte differentiation. Both in vitro and in vivo, Kdm5c dosage influenced gene expression involved in extracellular matrix remodeling, which is critical for adipocyte differentiation and adipose tissue expansion. In humans, adipose tissue KDM5C mRNA levels and KDM5C genetic variants were associated with body mass. These studies demonstrate that the sex-dependent dosage of Kdm5c contributes to male/female differences in adipocyte biology and highlight X-escape genes as a critical component of female physiology.
Journal Article
The importance of having two X chromosomes
by
Itoh, Yuichiro
,
Ghahramani, Negar
,
Li, Jingyuan
in
Animals
,
Female
,
Gene Expression Regulation - physiology
2016
Historically, it was thought that the number of X chromosomes plays little role in causing sex differences in traits. Recently, selected mouse models have been used increasingly to compare mice with the same type of gonad but with one versus two copies of the X chromosome. Study of these models demonstrates that mice with one X chromosome can be strikingly different from those with two X chromosomes, when the differences are not attributable to confounding group differences in gonadal hormones. The number of X chromosomes affects adiposity and metabolic disease, cardiovascular ischaemia/reperfusion injury and behaviour. The effects of X chromosome number are likely the result of inherent differences in expression of X genes that escape inactivation, and are therefore expressed from both X chromosomes in XX mice, resulting in a higher level of expression when two X chromosomes are present. The effects of X chromosome number contribute to sex differences in disease phenotypes, and may explain some features of X chromosome aneuploidies such as in Turner and Klinefelter syndromes.
Journal Article
X chromosome dosage drives statin-induced dysglycemia and mitochondrial dysfunction
2024
Statin drugs lower blood cholesterol levels for cardiovascular disease prevention. Women are more likely than men to experience adverse statin effects, particularly new-onset diabetes (NOD) and muscle weakness. Here we find that impaired glucose homeostasis and muscle weakness in statin-treated female mice are associated with reduced levels of the omega-3 fatty acid, docosahexaenoic acid (DHA), impaired redox tone, and reduced mitochondrial respiration. Statin adverse effects are prevented in females by administering fish oil as a source of DHA, by reducing dosage of the X chromosome or the
Kdm5c
gene, which escapes X chromosome inactivation and is normally expressed at higher levels in females than males. As seen in female mice, we find that women experience more severe reductions than men in DHA levels after statin administration, and that DHA levels are inversely correlated with glucose levels. Furthermore, induced pluripotent stem cells from women who developed NOD exhibit impaired mitochondrial function when treated with statin, whereas cells from men do not. These studies identify X chromosome dosage as a genetic risk factor for statin adverse effects and suggest DHA supplementation as a preventive co-therapy.
Women are more likely than men to experience adverse statin effects, particularly new-onset diabetes and muscle weakness. Here the authors show that statin-treated female mice show reduced levels of docosahexaenoic acid (DHA) and that the adverse effects are prevented by administering fish oil as a source of DHA, by reducing dosage of the X chromosome or the Kdm5c gene.
Journal Article
Diet, gonadal sex, and sex chromosome complement influence white adipose tissue miRNA expression
by
Cantor, Rita M.
,
Hasin-Brumshtein, Yehudit
,
Arnold, Arthur P.
in
Adipocytes
,
Adipogenesis
,
Adipose tissue
2017
Background
MicroRNAs (miRNAs) are small non-coding RNA molecules that regulate gene expression by targeting specific mRNA species for degradation or interfering with translation. Specific miRNAs are key regulators of adipogenesis, and are expressed at different levels in adipose tissue from lean and obese mice. The degree of lipid accumulation and distribution of white adipose tissue differs between males and females, and it is unknown whether sex differences in adipose tissue-specific miRNA expression may contribute to this dimorphism. Typically, sex differences are attributed to hormones secreted from ovaries or testes. However, the sex chromosome complement (XX
versus
XY) is also a determinant of sex differences and may regulate miRNA expression in adipocytes.
Results
To identify sex differences in adipose tissue miRNA expression and to understand the underlying mechanisms, we performed high-throughput miRNA sequencing in gonadal fat depots of the Four Core Genotypes mouse model. This model, which consists of XX female, XX male, XY female, and XY male mice, allowed us to assess independent effects of gonadal type (male
vs
. female) and sex chromosome complement (XX
vs
. XY) on miRNA expression profiles. We have also assessed the effects of a high fat diet on sex differences in adipose tissue miRNA profiles. We identified a male–female effect on the overall miRNA expression profile in mice fed a chow diet, with a bias toward higher expression in male compared to female gonadal adipose tissue. This sex bias disappeared after gonadectomy, suggesting that circulating levels of gonadal secretions modulate the miRNA expression profile. After 16 weeks of high fat diet, the miRNA expression distribution was shifted toward higher expression in XY
vs
. XX adipose tissue. Principal component analysis revealed that high fat diet has a substantial effect on miRNA profile variance, while gonadal secretions and sex chromosome complement each have milder effects.
Conclusions
Our results demonstrate that the overall miRNA expression profile in adipose tissue is influenced by gonadal hormones and the sex chromosome complement, and that expression profiles change in response to gonadectomy and high fat diet. Differential miRNA expression profiles may contribute to sex differences in adipose tissue gene expression, adipose tissue development, and diet-induced obesity.
Journal Article
Leveraging the potential of 3D total body photography: a data-driven tool for quality improvement and clinical research
by
Hardway, Heather D.
,
Cull, Deborah B.
,
Demer, Addison M.
in
Automation
,
Biomedical Research - methods
,
Biomedical Research - standards
2024
Metrics calculated in our dashboard to track total body photography performance Metric Calculation Malignant hit rate (MHR) MHR=MalignantlesionsMalignantlesions+Benignlesions Pigmented lesion hit rate (PLHR) PLHR=MalignantpigmentedlesionsMalignantpigmentedlesions+Benignpigmentedlesions Keratinocyte carcinoma hit rate (KCHR) KCHR=KeratinocytecarcinomasKeratinocytecarcinomas+benignkeratinocytelesions Seborrheic keratosis hit rate (SKHR) SKHR=SeborrheickeratosesTotalnumberofbiopsies Google Cloud Platform technologies, including BigQuery for data management and Looker Studio for data visualization, underscores the sophisticated infrastructure supporting our dashboard (Fig. 1). The presence of green dots represents a statistically significant difference in the value of the selected metric when comparing the post-exposure visits vs. pre-exposure visits in the exposed cohort (left) and/or the exposed vs. non-exposed cohort (right). Total body photography for the diagnosis of cutaneous melanoma in adults: a systematic review and meta-analysis.
Journal Article
Clinical practice of analysis of anti-drug antibodies against interferon beta and natalizumab in multiple sclerosis patients in Europe: A descriptive study of test results
2017
Antibodies against biopharmaceuticals (anti-drug antibodies, ADA) have been a well-integrated part of the clinical care of multiple sclerosis (MS) in several European countries. ADA data generated in Europe during the more than 10 years of ADA monitoring in MS patients treated with interferon beta (IFNβ) and natalizumab have been pooled and characterized through collaboration within a European consortium. The aim of this study was to report on the clinical practice of ADA testing in Europe, considering the number of ADA tests performed and type of ADA assays used, and to determine the frequency of ADA testing against the different drug preparations in different countries. A common database platform (tranSMART) for querying, analyzing and storing retrospective data of MS cohorts was set up to harmonize the data and compare results of ADA tests between different countries. Retrospective data from six countries (Sweden, Austria, Spain, Switzerland, Germany and Denmark) on 20,695 patients and on 42,555 samples were loaded into tranSMART including data points of age, gender, treatment, samples, and ADA results. The previously observed immunogenic difference among the four IFNβ preparations was confirmed in this large dataset. Decreased usage of the more immunogenic preparations IFNβ-1a subcutaneous (s.c.) and IFNβ-1b s.c. in favor of the least immunogenic preparation IFNβ-1a intramuscular (i.m.) was observed. The median time from treatment start to first ADA test correlated with time to first positive test. Shorter times were observed for IFNβ-1b-Extavia s.c. (0.99 and 0.94 years) and natalizumab (0.25 and 0.23 years), which were introduced on the market when ADA testing was already available, as compared to IFNβ-1a i.m. (1.41 and 2.27 years), IFNβ-1b-Betaferon s.c. (2.51 and 1.96 years) and IFNβ-1a s.c. (2.11 and 2.09 years) which were available years before routine testing began. A higher rate of anti-IFNβ ADA was observed in test samples taken from older patients. Testing for ADA varies between different European countries and is highly dependent on the policy within each country. For drugs where routine monitoring of ADA is not in place, there is a risk that some patients remain on treatment for several years despite ADA positivity. For drugs where a strategy of ADA testing is introduced with the release of the drug, there is a reduced risk of having ADA positive patients and thus of less efficient treatment. This indicates that potential savings in health cost might be achieved by routine analysis of ADA.
Journal Article
Occurrence of Anti-Drug Antibodies against Interferon-Beta and Natalizumab in Multiple Sclerosis: A Collaborative Cohort Analysis
2016
Immunogenicity of biopharmaceutical products in multiple sclerosis is a frequent side effect which has a multifactorial etiology. Here we study associations between anti-drug antibody (ADA) occurrence and demographic and clinical factors. Retrospective data from routine ADA test laboratories in Sweden, Denmark, Austria and Germany (Dusseldorf group) and from one research study in Germany (Munich group) were gathered to build a collaborative multi-cohort dataset within the framework of the ABIRISK project. A subset of 5638 interferon-beta (IFNβ)-treated and 3440 natalizumab-treated patients having data on at least the first two years of treatment were eligible for interval-censored time-to-event analysis. In multivariate Cox regression, IFNβ-1a subcutaneous and IFNβ-1b subcutaneous treated patients were at higher risk of ADA occurrence compared to IFNβ-1a intramuscular-treated patients (pooled HR = 6.4, 95% CI 4.9-8.4 and pooled HR = 8.7, 95% CI 6.6-11.4 respectively). Patients older than 50 years at start of IFNβ therapy developed ADA more frequently than adult patients younger than 30 (pooled HR = 1.8, 95% CI 1.4-2.3). Men developed ADA more frequently than women (pooled HR = 1.3, 95% CI 1.1-1.6). Interestingly we observed that in Sweden and Germany, patients who started IFNβ in April were at higher risk of developing ADA (HR = 1.6, 95% CI 1.1-2.4 and HR = 2.4, 95% CI 1.5-3.9 respectively). This result is not confirmed in the other cohorts and warrants further investigations. Concerning natalizumab, patients older than 45 years had a higher ADA rate (pooled HR = 1.4, 95% CI 1.0-1.8) and women developed ADA more frequently than men (pooled HR = 1.4, 95% CI 1.0-2.0). We confirmed previously reported differences in immunogenicity of the different types of IFNβ. Differences in ADA occurrence by sex and age are reported here for the first time. These findings should be further investigated taking into account other exposures and biomarkers.
Journal Article
Treatment- and population-specific genetic risk factors for anti-drug antibodies against interferon-beta: a GWAS
2020
Background
Upon treatment with biopharmaceuticals, the immune system may produce anti-drug antibodies (ADA) that inhibit the therapy. Up to 40% of multiple sclerosis patients treated with interferon β (IFNβ) develop ADA, for which a genetic predisposition exists. Here, we present a genome-wide association study on ADA and predict the occurrence of antibodies in multiple sclerosis patients treated with different interferon β preparations.
Methods
We analyzed a large sample of 2757 genotyped and imputed patients from two cohorts (Sweden and Germany), split between a discovery and a replication dataset. Binding ADA (bADA) levels were measured by capture-ELISA, neutralizing ADA (nADA) titers using a bioassay. Genome-wide association analyses were conducted stratified by cohort and treatment preparation, followed by fixed-effects meta-analysis.
Results
Binding ADA levels and nADA titers were correlated and showed a significant heritability (47% and 50%, respectively). The risk factors differed strongly by treatment preparation: The top-associated and replicated variants for nADA presence were the
HLA
-associated variants rs77278603 in IFNβ-1a
s.c.
- (odds ratio (OR) = 3.55 (95% confidence interval = 2.81–4.48),
p
= 2.1 × 10
−26
) and rs28366299 in IFNβ-1b
s.c.
-treated patients (OR = 3.56 (2.69–4.72),
p
= 6.6 × 10
−19
). The rs77278603-correlated
HLA
haplotype
DR15-DQ6
conferred risk specifically for IFNβ-1a
s.c.
(OR = 2.88 (2.29–3.61),
p
= 7.4 × 10
−20
) while
DR3-DQ2
was protective (OR = 0.37 (0.27–0.52),
p
= 3.7 × 10
−09
). The haplotype
DR4-DQ3
was the major risk haplotype for IFNβ-1b
s.c.
(OR = 7.35 (4.33–12.47),
p
= 1.5 × 10
−13
). These haplotypes exhibit large population-specific frequency differences. The best prediction models were achieved for ADA in IFNβ-1a
s.c.
-treated patients. Here, the prediction in the Swedish cohort showed AUC = 0.91 (0.85–0.95), sensitivity = 0.78, and specificity = 0.90; patients with the top 30% of genetic risk had, compared to patients in the bottom 30%, an OR = 73.9 (11.8–463.6,
p
= 4.4 × 10
−6
) of developing nADA. In the German cohort, the AUC of the same model was 0.83 (0.71–0.92), sensitivity = 0.80, specificity = 0.76, with an OR = 13.8 (3.0–63.3,
p
= 7.5 × 10
−4
).
Conclusions
We identified several
HLA
-associated genetic risk factors for ADA against interferon β, which were specific for treatment preparations and population backgrounds. Genetic prediction models could robustly identify patients at risk for developing ADA and might be used for personalized therapy recommendations and stratified ADA screening in clinical practice. These analyses serve as a roadmap for genetic characterizations of ADA against other biopharmaceutical compounds.
Journal Article
Human Leukocyte Antigen Genes and Interferon Beta Preparations Influence Risk of Developing Neutralizing Anti-Drug Antibodies in Multiple Sclerosis
2014
A significant proportion of patients with multiple sclerosis who receive interferon beta (IFNβ) therapy develop neutralizing antibodies (NAbs) that reduce drug efficacy. To investigate if HLA class I and II alleles are associated with development of NAbs against IFNβ we analyzed whether NAb status and development of NAb titers high enough to be biologically relevant (>150 tenfold reduction units/ml) correlated with the HLA allele group carriage in a cohort of 903 Swedish patients with multiple sclerosis treated with either intramuscular IFNβ-1a, subcutaneous IFNβ-1a or subcutaneous IFNβ-1b. Carriage of HLA-DRB1*15 was associated with increased risk of developing NAbs and high NAb titers. After stratification based on type of IFNβ preparation, HLA-DRB1*15 carriage was observed to increase the risk of developing NAbs as well as high NAb titers against both subcutaneous and intramuscular IFNβ-1a. Furthermore, in patients receiving subcutaneous IFNβ-1a carriage of HLA-DQA1*05 decreased the risk for high NAb titers. In IFNβ-1b treated patients, HLA-DRB1*04 increased the risk of developing high NAb titers, and in a subgroup analysis of DRB1*04 alleles the risk for NAbs was increased in DRB1*04:01 carriers. In conclusion, there is a preparation-specific genetically determined risk to develop NAbs against IFNβ high enough to be clinically relevant in treatment decisions for patients with multiple sclerosis if confirmed in future studies. However, choice of IFNβ preparation still remains the single most significant determinant for the risk of developing NAbs.
Journal Article
Genetic variation in the KIF1B locus influences susceptibility to multiple sclerosis
by
Broer, Linda
,
Dessa Sadovnick, A
,
Lundström, Wangko
in
Agriculture
,
Animal Genetics and Genomics
,
Biological and medical sciences
2008
Rogier Hintzen and colleagues report the results of a search for genetic variants associated with susceptibility to multiple sclerosis in a genetically isolated population that lead to identification of a new susceptibility locus in the region of the
KIF1B
gene on chromosome 1.
The few loci associated with multiple sclerosis (MS) are all related to immune function. We report a GWA study identifying a new locus replicated in 2,679 cases and 3,125 controls. An rs10492972[C] variant located in the
KIF1B
gene was associated with MS with an odds ratio of 1.35 (
P
= 2.5 × 10
−10
).
KIF1B
is a neuronally expressed gene plausibly implicated in the irreversible axonal loss characterizing MS in the long term.
Journal Article