| 1. |
- Willemse, Jorke, et al.
(författare)
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Hydrogels derived from decellularized liver tissue support the growth and differentiation of cholangiocyte organoids
- 2022
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Ingår i: Biomaterials. - : Elsevier BV. - 0142-9612. ; 284
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Tidskriftsartikel (refereegranskat)abstract
- Human cholangiocyte organoids are promising for regenerative medicine applications, such as repair of damaged bile ducts. However, organoids are typically cultured in mouse tumor-derived basement membrane extracts (BME), which is poorly defined, highly variable and limits the direct clinical applications of organoids in patients. Extracellular matrix (ECM)-derived hydrogels prepared from decellularized human or porcine livers are attractive alternative culture substrates. Here, the culture and expansion of human cholangiocyte organoids in liver ECM(LECM)-derived hydrogels is described. These hydrogels support proliferation of cholangiocyte organoids and maintain the cholangiocyte-like phenotype. The use of LECM hydrogels does not significantly alter the expression of selected genes or proteins, such as the cholangiocyte marker cytokeratin-7, and no species-specific effect is found between human or porcine LECM hydrogels. Proliferation rates of organoids cultured in LECM hydrogels are lower, but the differentiation capacity of the cholangiocyte organoids towards hepatocyte-like cells is not altered by the presence of tissue-specific ECM components. Moreover, human LECM extracts support the expansion of ICO in a dynamic culture set up without the need for laborious static culture of organoids in hydrogel domes. Liver ECM hydrogels can successfully replace tumor-derived BME and can potentially unlock the full clinical potential of human cholangiocyte organoids.
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| 2. |
- Zhou, Wei, et al.
(författare)
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Gene-based association analysis of a large patient cohort identifies potential genecandidates for atypical femur fractures
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Background:Several small genetic association studies have been conducted for atypical femurfracture (AFF) without replication of results. We assessed previously implicated and novel genesassociated with AFFs in a larger set of unrelated AFF cases using whole exome sequencing (WES).Methods:We performed gene-based association analysis on 139 European AFF cases and 196 controlsmatched for bisphosphonate use. We tested all rare, protein-altering variants using both candidategene and hypothesis-free approaches. In the latter, genes suggestively associated with AFFs(uncorrected p-values < 0.01) were investigated in a Swedish whole-genome sequencing replicationstudy and assessed in 46 non-European cases.Results:In the candidate gene analysis, PLOD2 showed a suggestive signal. The hypothesis-freeapproach revealed 10 tentative associations, with XRN2, SORD, and PLOD2 being the most likelycandidates for AFF. XRN2 and PLOD2 showed consistent direction of effect estimates in thereplication analysis, albeit not statistically significant. Three SNPs associated with SORD expressionaccording to the GTEx portal, were in linkage disequilibrium (R2 ≥0.2) with a SNP previouslyreported in a genome-wide association study of AFF. The prevalence of carriers of variants for bothPLOD2 and SORD was higher in Asian versus European cases.Conclusions:While we did not identify genes enriched for damaging variants, we found suggestiveevidence of a role for XRN2, PLOD2 and SORD, which requires further investigation. Our findingsindicate that genetic factors responsible for AFFs are not widely shared among AFF cases. The studyprovides a stepping-stone for future larger genetic studies of AFF.
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| 3. |
- Kemp, John P, et al.
(författare)
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Phenotypic dissection of bone mineral density reveals skeletal site specificity and facilitates the identification of novel loci in the genetic regulation of bone mass attainment.
- 2014
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Ingår i: PLoS genetics. - : Public Library of Science (PLoS). - 1553-7404. ; 10:6
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Tidskriftsartikel (refereegranskat)abstract
- Heritability of bone mineral density (BMD) varies across skeletal sites, reflecting different relative contributions of genetic and environmental influences. To quantify the degree to which common genetic variants tag and environmental factors influence BMD, at different sites, we estimated the genetic (rg) and residual (re) correlations between BMD measured at the upper limbs (UL-BMD), lower limbs (LL-BMD) and skull (SK-BMD), using total-body DXA scans of ∼ 4,890 participants recruited by the Avon Longitudinal Study of Parents and their Children (ALSPAC). Point estimates of rg indicated that appendicular sites have a greater proportion of shared genetic architecture (LL-/UL-BMD rg = 0.78) between them, than with the skull (UL-/SK-BMD rg = 0.58 and LL-/SK-BMD rg = 0.43). Likewise, the residual correlation between BMD at appendicular sites (r(e) = 0.55) was higher than the residual correlation between SK-BMD and BMD at appendicular sites (r(e) = 0.20-0.24). To explore the basis for the observed differences in rg and re, genome-wide association meta-analyses were performed (n ∼ 9,395), combining data from ALSPAC and the Generation R Study identifying 15 independent signals from 13 loci associated at genome-wide significant level across different skeletal regions. Results suggested that previously identified BMD-associated variants may exert site-specific effects (i.e. differ in the strength of their association and magnitude of effect across different skeletal sites). In particular, variants at CPED1 exerted a larger influence on SK-BMD and UL-BMD when compared to LL-BMD (P = 2.01 × 10(-37)), whilst variants at WNT16 influenced UL-BMD to a greater degree when compared to SK- and LL-BMD (P = 2.31 × 10(-14)). In addition, we report a novel association between RIN3 (previously associated with Paget's disease) and LL-BMD (rs754388: β = 0.13, SE = 0.02, P = 1.4 × 10(-10)). Our results suggest that BMD at different skeletal sites is under a mixture of shared and specific genetic and environmental influences. Allowing for these differences by performing genome-wide association at different skeletal sites may help uncover new genetic influences on BMD.
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| 4. |
- Suijkerbuijk, Mathijs A. M., et al.
(författare)
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Functional polymorphisms within the inflammatory pathway regulate expression of extracellular matrix components in a genetic risk dependent model for anterior cruciate ligament injuries.
- 2019
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Ingår i: Journal of Science and Medicine in Sport. - : Elsevier. - 1440-2440 .- 1878-1861. ; 22:11, s. 1219-1225
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To investigate the functional effect of genetic polymorphisms of the inflammatory pathway on structural extracellular matrix components (ECM) and the susceptibility to an anterior cruciate ligament (ACL) injury.DESIGN: Laboratory study, case-control study.METHODS: Eight healthy participants were genotyped for interleukin (IL)1B rs16944 C>T and IL6 rs1800795 G>C and classified into genetic risk profile groups. Differences in type I collagen (COL1A1), type V collagen (COL5A1), biglycan (BGN) and decorin (DCN) gene expression were measured in fibroblasts either unstimulated or following IL-1β, IL-6 or tumor necrosis factor (TNF)-α treatment. Moreover, a genetic association study was conducted in: (i) a Swedish cohort comprised of 116 asymptomatic controls (CON) and 79 ACL ruptures and (ii) a South African cohort of 100 CONs and 98 ACLs. Participants were genotyped for COL5A1 rs12722 C>T, IL1B rs16944 C>T, IL6 rs1800795 G>C and IL6R rs2228145 G>C.RESULTS: IL1B high-risk fibroblasts had decreased BGN (p=0.020) and COL5A1 (p=0.012) levels after IL-1β stimulation and expressed less COL5A1 (p=0.042) following TNF-α treatment. Similarly, unstimulated IL6 high-risk fibroblasts had lower COL5A1 (p=0.012) levels than IL6 low-risk fibroblasts. In the genetic association study, the COL5A1-IL1B-IL6 T-C-G (p=0.034, Haplo-score 2.1) and the COL5A1-IL1B-IL6R T-C-A (p=0.044, Haplo-score: 2.0) combinations were associated with an increased susceptibility to ACL injury in the Swedish cohort when only male participants were evaluated.CONCLUSIONS: This study shows that polymorphisms within genes of the inflammatory pathway modulate the expression of structural and fibril-associated ECM components in a genetic risk depended manner, contributing to an increased susceptibility to ACL injuries.
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