The regeneration of diseased hyaline cartilage remains a great challenge, mainly because degeneration activities after major injury or due to age-related processes overwhelm the self-renewal capacity of the tissue. We show that repair tissue from human articular cartilage of late stages of osteoarthritis harbor a unique progenitor cell population, termed chondrogenic progenitor cells exhibiting stem cell characteristics, such as multipotency, lack of immune system activation and, in particular, migratory activity. The isolated CPC exhibit a high chondrogenic potential and were able to populate diseased tissue in vivo. Moreover, down-regulation of the osteogenic transcription factor runx-2 enhanced the expression of the chondrogenic transcription factor sox-9 and consequently the matrix synthesis potential of chondrogenic progenitor cells. Our results, while offering new insight into the biology of progenitor cells from diseased cartilage tissue, might assist future strategies to treat late stages of osteoarthritis.
Migratory chondrogenic progenitor cells from repair tissue during the later stages of human osteoarthritis.
No sample metadata fields
View SamplesThe transcriptomic profiling of psoriasis has led to an increased understanding of disease pathogenesis. Although microarray technologies have been instrumental in this regard, it is clear that these tools detect an incomplete set of DEGs. RNA-seq can be used to supplement these prior technologies. Here, the use of RNAseq methods substantially increased the number of psoriasis-related DEGs. Furthermore, DEGs that were uniquely identified by RNA-seq, but not in other published microarray studies, further supported the role of IL-17 and tumor necrosis factor-a synergy in psoriasis. Examination of one of these factors at the protein level confirmed that RNA-seq is a powerful tool that can be used to identify molecular factors present in psoriasis lesions, and may be useful in the identification of therapeutic targets that to our knowledge have not been reported previously. Further studies are in progress to determine the biological significance of DEGs uniquely discovered by RNA-seq. Overall design: To define the transcriptomic profile of psoriatic skin, three pairs of lesional and nonlesional skin biopsy specimens were taken from patients with untreated moderate-to-severe plaque psoriasis.
Transcriptional profiling of psoriasis using RNA-seq reveals previously unidentified differentially expressed genes.
Specimen part, Subject
View SamplesA gene expression profiling sub-study was conducted in which skin biopsy samples were collected from 85 patients with moderate-to-severe psoriasis who were participating in ACCEPT, an IRB-approved Phase 3, multicenter, randomized trial. This analysis identified 4,175 probe-sets as being significantly modulated in psoriasis lesions (LS) compared with matched biopsies of non-lesional (NL) skin.
Expanding the psoriasis disease profile: interrogation of the skin and serum of patients with moderate-to-severe psoriasis.
Specimen part, Disease, Disease stage, Subject
View SamplesAlefacept treatment is highly effective in a select group patients with moderate-to-severe psoriasis, and is an ideal candidate to develop systems to predict who will respond to therapy. A clinical trial of 22 patients with moderate to severe psoriasis treated with alefacept (7.5mg weekly i.v. x12 weeks) was conducted in 2002-2003, as a mechanism of action study. Patients were classified as responders or non-responders to alefacept based on histological criteria. Microarray data from PBMCs of 16 of these patients was analyzed to generate a treatment response classifier. We used a discriminant analysis method that performs sample classification from gene expression data, via nearest shrunken centroid method''. A disease response classifier using 23 genes was created to accurately predict response to alefacept (12.3% error rate in favour of responders). This preliminary study may provide a useful tool to predict response of psoriatic patients with alefacept.
Personalized medicine in psoriasis: developing a genomic classifier to predict histological response to Alefacept.
Sex, Age, Specimen part, Subject
View SamplesThe molecular regulation of zygotic genome activation (ZGA) in mammals remains poorly understood. Primed mouse embryonic stem cells contain a rare subset of “2C-like” cells that are epigenetically and transcriptionally similar to the two cell embryo and thus represent an ideal system for studying ZGA transcription regulation. Recently, the transcription factor Dux, expressed exclusively in the minor wave of ZGA, was described to activate many downstream ZGA transcripts. However, it remains unknown what upstream maternal factors initiate ZGA either in a Dux dependent or independent manner. Here we performed a candidate-based overexpression screen, identifying, amongst others, Developmental Pluripotency Associated 2 (Dppa2) and 4 (Dppa4) as positive regulators of 2C-like cells and ZGA transcription. In the germ line, promoter DNA demethylation coincides with upregulation of Dppa2 and Dppa4 which remain expressed until E7.5 when their promoters are remethylated. Furthermore, Dppa2 and Dppa4 are also expressed during iPSC reprogramming at the time 2C-like ZGA transcription transiently peaks. Through a combination of overexpression, knockdown, knockout and rescue experiments, together with transcriptional analyses, we show that Dppa2 and Dppa4 directly regulate the 2C-like cell population and associated transcripts, including Dux and the Zscan4 cluster. Importantly, we tease apart the molecular hierarchy in which the 2C-like transcriptional program is initiated and stabilised. Dppa2 and Dppa4 require Dux to initiate 2C-like ZGA transcription, suggesting they act upstream by directly regulating Dux. Supporting this, ChIP-seq analysis revealed Dppa2 and Dppa4 bind to the Dux promoter and gene body and drive its expression. Zscan4c is also able to induce 2C-like cells in wild type cells, but, in contrast to Dux, can no longer do so in Dppa2/4 double knockout cells, suggesting it may act to stabilise rather than drive the transcriptional network. Our findings suggest a model in which Dppa2/4 binding to the Dux promoter leads to Dux upregulation and activation of the 2C-like transcriptional program which is subsequently reinforced by Zscan4c. Overall design: RNA sequencing of screen hits (3 biological replicates of GFP+ and GFP- sorted cells for each of 12 candidates).
Dppa2 and Dppa4 directly regulate the Dux-driven zygotic transcriptional program.
Specimen part, Cell line, Subject
View SamplesThere is a controversy surrounding the existence of palmoplantar pustulosis (PPP) and palmoplantar pustular psoriasis (PPPP) as separate clinical entities or as variants of the same clinical entity. We used gene expression microarray to compare gene expression in PPP and PPPP. PPP and PPPP could not be differentiated using gene expression microarray suggesting that they are not distinct clinical entities. Increased expression of GPRIN1, and ADAM23 in keratinocytes suggests that these proteins could be new therapeutic targets for PPP/PPPP.
Based on Molecular Profiling of Gene Expression, Palmoplantar Pustulosis and Palmoplantar Pustular Psoriasis Are Highly Related Diseases that Appear to Be Distinct from Psoriasis Vulgaris.
Specimen part, Disease, Subject
View SamplesScalp psoriasis shows a variable clinical spectrum and in many cases poses a great therapeutic challenge. However, it remains unknown whether the immune response of scalp psoriasis differs from understood pathomechanisms of psoriasis on other skin areas. We sought to determine the cellular and mollecular phenotype of scalp psoriasis by performing a comparative analysis of scalp vs skin using lesional and nonlesional samples from 20 Caucasian subjects with untreated moderate to severe psoriasis and significant scalp involvement, and 10 control subjects without psoriasis. Our results suggest that even in the scalp psoriasis is a disease of the inter-follicular skin. The immune mechanisms that mediate scalp psoriasis were found to be similar to those involved in skin psoriasis. However, the magnitude of dysregulation, number of differentially expressed genes, and enrichment of the psoriatic genomic fingerprinting were more prominent in skin lesions. Furthermore, the scalp transcriptome showed increased modulation of several gene-sets, particularly those induced by interferon-gamma, compared with skin psoriasis which was mainly associated with activation of TNF/L-17/IL-22-induced keratinocyte response genes. We also detected differences in expression of gene-sets involving negative regulation, epigenetic regulation, epidermal differentiation, and dendritic cell or Th1/Th17/Th22-related T-cell processes.
Molecular and Cellular Profiling of Scalp Psoriasis Reveals Differences and Similarities Compared to Skin Psoriasis.
Specimen part, Disease, Disease stage
View SamplesMaternal smoking doubles the risk of delivering a low birth weight infant. The purpose of this study was to analyze differential gene expression in umbilical cord tissue as a function of maternal smoking, with an emphasis on growth-related genes. We recruited 15 pregnant smokers and 15 women who never smoked during pregnancy to participate RNA was isolated from umbilical cord tissue collected and snap frozen at the time of delivery. Microarray analysis was performed using the Affymetrix GeneChip Scanner 3000.Six hundred seventy-eight probes corresponding to 545 genes were differentially expressed (i.e., an intensity ratio that exceeded +/-1.3 and a corrected significance value p < 0.005) in tissue obtained from smokers versus nonsmokers. Genes important for fetal growth, angiogenesis, or development of connective tissue matrix were up-regulated among smokers. The most highly up-regulated gene was CSH1, a somatomammotropin gene. Two other somatomammotropin genes (CSH2 and CSH-L1) were also up-regulated. The most highly down-regulated gene was APOBEC3A; other down-regulated genes included those that may be important in immune and barrier protection. PCR validation of the three somatomammotropin genes showed a high correlation between qPCR and microarray expression. Consequently, maternal smoking may be associated with altered gene expression in the offspring.
Effects of prenatal tobacco exposure on gene expression profiling in umbilical cord tissue.
No sample metadata fields
View SamplesPsoriasis is a complex inflammatory disease resulting from the activation of T helper (Th) 1 and Th17 cells. Recent evidence suggests that abnormal activation of Toll-like receptors (TLRs) 7, 8 and 9 contributes to the initiation and maintenance of psoriasis. We have evaluated the effects of TLR antagonists on the gene expression profile in an IL-23-induced skin inflammation model in mice. Psoriasis-like skin lesions were induced in C57BL/6 mice by intradermal injection of IL-23 in the dorsum. Two TLR antagonists were compared: IMO-3100, an antagonist of TLRs 7 and 9, and IMO-8400, an antagonist of TLRs 7, 8 and 9, both of which previously have been shown to reduce epidermal hyperplasia in this model. Skin gene expression profiles of IL-23-induced inflammation were compared with or without TLR antagonist treatment. IL-23 injection resulted in alteration of 5100 gene probes (fold change 2, FDR < 0.05) including IL-17 pathways that are up-regulated in psoriasis vulgaris. Targeting TLRs 7, 8 and 9 with IMO-8400 resulted in modulation of more than 2300 mRNAs while targeting TLRs 7 and 9 with IMO-3100 resulted in modulation of more than 1900 mRNAs. Both agents strongly decreased IL-17A expression (>12-fold reduction), normalized IL-17 induced genes such as beta-defensin and CXCL1, and normalized aberrant expression of keratin 16 (indicating epidermal hyperplasia). These results suggest that IL-23-driven inflammation in mouse skin may be dependent on signaling mediated by TLRs 7, 8, and 9 and that these receptors represent novel therapeutic targets in psoriasis vulgaris and other diseases with similar pathophysiology.
Suppression of molecular inflammatory pathways by Toll-like receptor 7, 8, and 9 antagonists in a model of IL-23-induced skin inflammation.
Treatment
View SamplesThe molecular regulation of zygotic genome activation (ZGA) in mammals remains poorly understood. Primed mouse embryonic stem cells contain a rare subset of “2C-like” cells that are epigenetically and transcriptionally similar to the two cell embryo and thus represent an ideal system for studying ZGA transcription regulation. Recently, the transcription factor Dux, expressed exclusively in the minor wave of ZGA, was described to activate many downstream ZGA transcripts. However, it remains unknown what upstream maternal factors initiate ZGA either in a Dux dependent or independent manner. Here we performed a candidate-based overexpression screen, identifying, amongst others, Developmental Pluripotency Associated 2 (Dppa2) and 4 (Dppa4) as positive regulators of 2C-like cells and ZGA transcription. In the germ line, promoter DNA demethylation coincides with upregulation of Dppa2 and Dppa4 which remain expressed until E7.5 when their promoters are remethylated. Furthermore, Dppa2 and Dppa4 are also expressed during iPSC reprogramming at the time 2C-like ZGA transcription transiently peaks. Through a combination of overexpression, knockdown, knockout and rescue experiments, together with transcriptional analyses, we show that Dppa2 and Dppa4 directly regulate the 2C-like cell population and associated transcripts, including Dux and the Zscan4 cluster. Importantly, we tease apart the molecular hierarchy in which the 2C-like transcriptional program is initiated and stabilised. Dppa2 and Dppa4 require Dux to initiate 2C-like ZGA transcription, suggesting they act upstream by directly regulating Dux. Supporting this, ChIP-seq analysis revealed Dppa2 and Dppa4 bind to the Dux promoter and gene body and drive its expression. Zscan4c is also able to induce 2C-like cells in wild type cells, but, in contrast to Dux, can no longer do so in Dppa2/4 double knockout cells, suggesting it may act to stabilise rather than drive the transcriptional network. Our findings suggest a model in which Dppa2/4 binding to the Dux promoter leads to Dux upregulation and activation of the 2C-like transcriptional program which is subsequently reinforced by Zscan4c. Overall design: RNA-sequencing of ESCs treated with control, Dppa2 or Dppa4 siRNAs for 4 days.
Dppa2 and Dppa4 directly regulate the Dux-driven zygotic transcriptional program.
Specimen part, Cell line, Subject
View Samples