Sjur Reppe

Sjur Reppe
Oslo University Hospital · Department of Medical Biochemistry

PhD

About

133
Publications
9,336
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3,226
Citations
Citations since 2016
50 Research Items
2048 Citations
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2016201720182019202020212022050100150200250300
2016201720182019202020212022050100150200250300
2016201720182019202020212022050100150200250300

Publications

Publications (133)
Article
Dental occlusion requires harmonious development of teeth, jaws, and other elements of the craniofacial complex, which are regulated by environmental and genetic factors. We performed the first genome-wide association study (GWAS) on dental development (DD) using the Demirjian radiographic method. Radiographic assessments from participants of the G...
Article
Full-text available
Background A striking effect of old age is the involuntary loss of muscle mass and strength leading to sarcopenia and reduced physiological functions. However, effects of heavy-load exercise in older adults on diseases and functions as predicted by changes in muscle gene expression have been inadequately studied. Methods Thigh muscle global transc...
Article
Full-text available
Background: Physical molecular interactions are the basis of intracellular signalling and gene regulatory networks, and comprehensive, accessible databases are needed for their discovery. Highly correlated transcripts may reflect important functional associations, but identification of such associations from primary data are cumbersome. We have co...
Preprint
Sclerostin inhibition is a new therapeutic approach for increasing bone mineral density (BMD) but its cardiovascular safety is unclear. We conducted a genome-wide association study (GWAS) meta-analysis of circulating sclerostin in 33,961 Europeans followed by Mendelian randomization (MR) to estimate the causal effects of sclerostin on 15 atheroscle...
Article
Full-text available
Mechanical loading exerts a profound influence on bone density and architecture, but the exact mechanism is unknown. Our study shows that expression of the neurological transcriptional factor zinc finger of the cerebellum 1 (ZIC1) is markedly increased in trabecular bone biopsies in the lumbar spine compared with the iliac crest, skeletal sites of...
Preprint
Full-text available
Background Physical molecular interactions are the basis of intracellular signalling and gene regulatory networks, and comprehensive, accessible databases are needed for their discovery. Highly correlated transcripts may reflect important functional associations, but identification of such associations from primary data are cumbersome. Therefore, w...
Article
Full-text available
The availability of large human datasets for genome-wide association studies (GWAS) and the advancement of sequencing technologies have boosted the identification of genetic variants in complex and rare diseases in the skeletal field. Yet, interpreting results from human association studies remains a challenge. To bridge the gap between genetic ass...
Preprint
Full-text available
Skull bone mineral density (SK-BMD) provides a suitable trait for the discovery of genes important to bone biology in general, and particularly for identifying components unique to intramembranous ossification, which cannot be captured at other skeletal sites. We assessed genetic determinants of SK-BMD in 43,800 individuals, identifying 59 genome-w...
Article
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Purpose Lipocalin 2 (LCN2) is an adipokine involved in many physiological functions, including bone metabolism. We previously demonstrated its implication in animal models of mechanical unloading-induced osteoporosis and in a cohort of bed rest volunteers. We therefore aimed at studying its involvement in postmenopausal osteoporosis. Methods We me...
Article
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Purpose: Seeking to improve the access to regenerative medicine, this study investigated the structural and transcriptional effects of storage temperature on human oral mucosal epithelial cells (OMECs). Methods: Cells were stored at four different temperatures (4°C, 12°C, 24°C and 37°C) for two weeks. Then, the morphology, cell viability and dif...
Article
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We previously demonstrated that the silk protein sericin promotes pigmentation of retinal pigment epithelium (RPE) by activating the NF-κB pathway. Among numerous agents, NF-κB can be activated by hydrogen peroxide. In the present study, we explored possible associations between reactive oxygen species and sericin-induced melanogenesis in RPE. The...
Article
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Although radiotherapy is a common form of treatment for head and neck cancer, it may lead to tissue damage in the salivary and lacrimal glands, possibly affecting cytokine expression in the gland fluid of treated individuals. Cytokine profiles in saliva and tear fluid of 29 radiated head and neck cancer patients and 20 controls were screened using...
Article
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Background: Clinical evidence suggests that body muscle mass is positively associated with bone mass, of significance for the elderly population at risk of osteoporosis (OP). Furthermore, muscle and bone interact mechanically and functionally, via local interactions as well as remotely via secreted components. Thus, it was of interest to compare mu...
Article
Full-text available
Transplantation of cultured epidermal cell sheets (CES) can be life-saving for patients with large area burns. CES have also been successfully used to regenerate eye and urethral epithelia in animal models. Short-term storage aims to extend the transplantation window, offers flexibility in timing surgery and allows testing of CES quality, phenotype...
Article
Full-text available
We investigated mechanisms resulting in low bone mineral density (BMD) and susceptibility to fracture by comparing non-coding RNAs (ncRNAs) in biopsies of non-weight-bearing (NWB) iliac (n = 84) and weight bearing (WB) femoral (n = 18) postmenopausal bone across BMDs varying from normal (T-score > -1.0) to osteoporotic (T-score ≤ -2.5). Global bone...
Article
Full-text available
In bone, sclerostin is mainly osteocyte‐derived and plays an important local role in adaptive responses to mechanical loading. Whether circulating levels of sclerostin also play a functional role is currently unclear, which we aimed to examine by two sample Mendelian Randomisation (MR). A genetic instrument for circulating sclerostin, derived from...
Article
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Investigating cytokines in tear fluid and saliva may offer valuable information for understanding the pathogenesis of primary Sjögren’s syndrome (pSS). Cytokine profiles in both tear fluid and saliva of pSS patients, non-Sjögren’s syndrome (non-SS) subjects with sicca symptoms, and healthy controls without sicca complaints were analysed. Furthermor...
Article
Hip geometry is an important predictor of fracture. We performed a meta‐analysis of GWAS studies in adults to identify genetic variants that are associated with proximal femur geometry phenotypes. We analyzed four phenotypes: (i) femoral neck length; (ii) neck‐shaft angle; (iii) femoral neck width, and (iv) femoral neck section modulus, estimated f...
Article
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There is a need to optimize storage conditions to preserve cell characteristics during transport of cultured cell sheets from specialized culture units to distant hospitals. In this study, we aimed to explore a method to identify additives that diminish the decrease in the viability of stored undifferentiated epidermal cells using multifactorial de...
Preprint
Full-text available
In bone, sclerostin is mainly osteocyte-derived and plays an important local role in adaptive responses to mechanical loading. Sclerostin is also present at detectable concentrations within the circulation. Our genome wide association study (GWAS) meta-analysis of 10,584 European-descent individuals identified two novel serum sclerostin loci, B4GAL...
Poster
Full-text available
The causes and molecular pathogenesis of postmenopausal osteoporosis (PMO) are far from understood even though osteoporotic fractures affect almost 50% of women above 50 years of age, resulting in e.g. femoral neck fractures imposing high risk to normal life. We addressed this issue by characterizing the global non-coding RNA (ncRNA) transcriptomes...
Article
The advancement of human retinal pigment epithelial cell (hRPE) replacement therapy is partly dependent on optimization of cell culture, cell preservation, and storage medium. This study was undertaken to search for a suitable storage temperature and storage medium for hRPE. hRPE monolayer sheets were cultured under standard conditions at 37°C and...
Article
Full-text available
Storage of human retinal pigment epithelium (hRPE) can contribute to the advancement of cell-based RPE replacement therapies. The present study aimed to improve the quality of stored hRPE cultures by identifying storage medium additives that, alone or in combination, contribute to enhancing cell viability while preserving morphology and phenotype....
Article
Full-text available
Background: Using high-dimensional penalized regression we studied genome-wide DNA-methylation in bone biopsies of 80 postmenopausal women in relation to their bone mineral density (BMD). The women showed BMD varying from severely osteoporotic to normal. Global gene expression data from the same individuals was available, and since DNA-methylation...
Article
Full-text available
MicroRNAs (miRNAs) are small non-coding RNA molecules that post-transcriptionally regulate the translation of messenger RNAs. Given the crucial role of miRNAs in gene expression, genetic variants within miRNA-related sequences may affect miRNA function and contribute to disease risk. Osteoporosis is characterized by reduced bone mass, and bone mine...
Article
Objectives To identify genetic determinants of susceptibility to clinical vertebral fractures, which is an important complication of osteoporosis. Methods Here we conduct a genome-wide association study in 1553 postmenopausal women with clinical vertebral fractures and 4340 controls, with a two-stage replication involving 1028 cases and 3762 contr...
Article
Full-text available
Cultured epidermal cell sheets (CES) containing undifferentiated cells are useful for treating skin burns and have potential for regenerative treatment of other types of epithelial injuries. The undifferentiated phenotype is therefore important for success in both applications. This study aimed to optimize a method for one-week storage of CES for t...
Article
Full-text available
Bone mineral density is known to be a heritable, polygenic trait whereas genetic variants contributing to lean mass variation remain largely unknown. We estimated the shared SNP heritability and performed a bivariate GWAS meta-analysis of total-body lean mass (TB-LM) and total-body less head bone mineral density (TBLH-BMD) regions in 10,414 childre...
Article
DNA methylation affects expression of associated genes and may contribute to the missing genetic effects from genome-wide association studies of osteoporosis. To improve insight into the mechanisms of postmenopausal osteoporosis, we combined transcript profiling with DNA methylation analyses in bone. RNA and DNA were isolated from 84 bone biopsies...
Article
The skeleton is a metabolically active organ throughout life where specific bone cell activity and paracrine/endocrine factors regulate its morphogenesis and remodeling. In recent years, an increasing number of reports have used multi-omics technologies to characterize subsets of bone biological molecular networks. The skeleton is affected by prima...
Article
Purpose The advancement of human retinal pigment epithelial (HRPE) cell replacement therapy for retinal blindness is partly dependent on optimization of cell culture, cell preservation, and storage medium. This study aims at optimizing the storage temperature and storage medium for HRPE cells. Methods HRPE cells were cultured under standard condit...
Article
Full-text available
Background: It is useful to incorporate biological knowledge on the role of genetic determinants in predicting an outcome. It is, however, not always feasible to fully elicit this information when the number of determinants is large. We present an approach to overcome this difficulty. First, using half of the available data, a shortlist of potenti...
Article
Full-text available
Genome-wide association studies (GWAS) have revealed numerous loci for areal bone mineral density (aBMD). We completed the first GWAS meta-analysis (N = 15,275) of lumbar spine volumetric BMD (vBMD) measured by quantitative computed tomography (QCT), allowing for examination of the trabecular bone compartment. SNPs that were significantly associate...
Article
Phenotype of cultured ocular epithelial transplants has been shown to affect clinical success rates following transplantation to the cornea. The purpose of this study was to evaluate the relationship between cell nucleus morphometry and phenotype in three types of cultured epithelial cells. This study provides knowledge for the development of a non...
Article
Full-text available
Restoration of the retinal pigment epithelial (RPE) cells to prevent further loss of vision in patients with age-related macular degeneration represents a promising novel treatment modality. Development of RPE transplants, however, requires up to 3 months of cell differentiation. We explored whether the silk protein sericin can induce maturation of...
Article
Full-text available
Bone Mineral Density (BMD) is a highly heritable trait, but genome-wide association studies have identified few genetic risk factors. Epidemiological studies suggest associations between BMD and several traits and diseases, but the nature of the suggestive comorbidity is still unknown. We used a novel genetic pleiotropy-informed conditional False D...
Data
Conditional FDR 2-D lookup table for femoral neck BMD. Based on the combination of p-value for the SNPs in femoral neck BMD (PBMD) and that of the pleiotropic trait: A. type 1 diabetes (T1D), B. type 2 diabetes (T2D), C. systolic blood pressure (SBP), D. diastolic blood pressure (DBP), E. high density lipoprotein (HDL), F. low density lipoprotein (...
Data
Conditional FDR 2-D lookup table for Lumbar Spine BMD. Based on the combination of p-value for the SNPs in lumbar spine BMD (PBMD) and that of the pleiotropic trait: A. type 1 diabetes (T1D), B. type 2 diabetes (T2D), C. systolic blood pressure (SBP), D. diastolic blood pressure (DBP), E. high density lipoprotein (HDL), F. low density lipoprotein (...
Data
Summary data from all GWAS used in the current study (DOCX)
Data
All identified loci associated with femoral neck BMD (DOCX)
Data
Gene titles and gene ontology function terms of genes associated with LS an FN BMD loci at FDR <0.01 (DOCX)
Data
QQ plots for Lumbar Spine-BMD. Conditional Q-Q plot of nominal versus empirical -log10 p-values (corrected for inflation) in bone mineral density (BMD, lumbar spine) below the standard GWAS threshold of p < 5x10-8 as a function of significance of association with A. type 1 diabetes (T1D), B. type 2 diabetes (T2D), C. systolic blood pressure (SBP),...
Data
Conditional QQ plot for lumbar spine BMD on CAD. Conditional Q-Q plot of nominal versus empirical -log10 p-values (corrected for inflation) in bone mineral density (BMD, lumbar spine) below the standard GWAS threshold of p < 5x10-8 as a function of significance of association with Coronary Artery Disease (CAD) at the level of -log10(p) ≥ 0 (all SNP...
Data
Identified loci containing novel SNPs or genes associated with lumbar spine BMD (DOCX)
Data
Identified loci containing known SNPs or genes associated with lumbar spine BMD (DOCX)
Data
Genetic pleiotropy enrichment. Conditional Q-Q plot of nominal versus empirical -log10 p-values (corrected for inflation) in bone mineral density (BMD, femoral neck) below the standard GWAS threshold of p < 5x10-8 as a function of significance of association with CVD risk factors, including type 1 diabetes (T1D), type 2 diabetes (T2D), low density...
Data
Conditional QQ plot for Femoral neck BMD on CAD. Conditional Q-Q plot of nominal versus empirical -log10 p-values (corrected for inflation) in bone mineral density (BMD, femoral neck) below the standard GWAS threshold of p < 5x10-8 as a function of significance of association with Coronary Artery Disease (CAD) at the level of -log10(p) ≥ 0 (all SNP...
Data
Details of Statistical Analysis (DOC)
Data
Conditional FDR Manhattan plots for lumbar spine BMD. ‘Conditional Manhattan plot’ of conditional–log10 (FDR) values for bone mineral density (BMD, lumbar spine) alone (small black dots) and BMD given the associated phenotypes type 1 diabetes (T1D; BMD|T1D), type 2 diabetes (T2D; BMD|T2D), systolic blood pressure (SBP; BMD|SBP), diastolic blood pre...