We compared quantitative RT-PCR (qRT-PCR), RNA-seq and capture sequencing (CaptureSeq) in terms of their ability to assemble and quantify long noncoding RNAs and novel coding exons across 20 human tissues. CaptureSeq was superior for the detection and quantification of genes with low expression, showed little technical variation and accurately measured differential expression. This approach expands and refines previous annotations and simultaneously generates an expression atlas.

IntroductionAnkylosing spondylitis (AS) is unique in its pathology where inflammation commences at the entheses before progressing to an osteoproliferative phenotype generating excessive bone formation that can result in joint fusion. The underlying mechanisms of this progression are poorly understood. Recent work has suggested that changes in Wnt signalling, a key bone regulatory pathway, may contribute to joint ankylosis in AS. Using the proteoglycan-induced spondylitis (PGISp) mouse model which displays spondylitis and eventual joint fusion following an initial inflammatory stimulus, we have characterised the structural and molecular changes that underlie disease progression.MethodsPGISp mice were characterised 12 weeks after initiation of inflammation using histology, immunohistochemistry (IHC) and expression profiling.ResultsInflammation initiated at the periphery of the intervertebral discs progressing to disc destruction followed by massively excessive cartilage and bone matrix formation, as demonstrated by toluidine blue staining and IHC for collagen type I and osteocalcin, leading to syndesmophyte formation. Expression levels of DKK1 and SOST, Wnt signalling inhibitors highly expressed in joints, were reduced by 49% and 63% respectively in the spine PGISp compared with control mice (P < 0.05) with SOST inhibition confirmed by IHC. Microarray profiling showed genes involved in inflammation and immune-regulation were altered. Further, a number of genes specifically involved in bone regulation including other members of the Wnt pathway were also dysregulated.ConclusionsThis study implicates the Wnt pathway as a likely mediator of the mechanism by which inflammation induces bony ankylosis in spondyloarthritis, raising the potential that therapies targeting this pathway may be effective in preventing this process.

In accordance with studies demonstrating that polymorphisms that increase aminopeptidase activity predispose to immune disease, the increased risk also attributed to increased expression of ERAP1 and ERAP2 supports the notion of using aminopeptidase inhibition to treat AS and other ERAP-associated conditions.

Ankylosing spondylitis (AS) is a common immune-mediated arthropathy primarily affecting the spine and pelvis. Most AS patients have subclinical intestinal inflammation, suggesting the gut microbiome and the immune response play a role in pathogenesis. Susceptibility to AS is primarily genetic, and at least 114 susceptibility variants have been identified to date. We applied bioinformatic methods utilizing epigenetic and gene and protein expression data to identify the cell types through which AS-associated variants operate. Variants were enriched in transcriptionally regulated regions in monocytes, CD4 and CD8 T cells, natural killer cells, regulatory T cells and B cells and mucosa from the small intestine, sigmoid colon and rectum. Weak signals were detected in bone cells, consistent with bone disease being a secondary manifestation. RNA sequencing of blood cells from AS patients and controls identified differentially expressed genes. Interrogation of expression databases showed that the upregulated genes were enriched in monocytes and downregulated genes were enriched in CD8 T cells and natural killer cells. Gene Ontology term enrichment analysis identified microbes and the gut in the aetiology of AS. These findings identify the key immune cell types that drive the disease, and further highlight the involvement of the gut microbiome in the pathogenesis of AS.

BackgroundNo treatment to date is available which specifically targets bone formation in ankylosing spondylitis (AS). Several recent studies have shown that sclerostin (SOST), a Wnt inhibitor specific to osteocytes and chondrocytes, is down-regulated in AS patients. This suggests Wnt signalling may be upregulated, and application of exogenous recombinant SOST (rSOST) may inhibit Wnt signalling and slow pathological bone formation.MethodsThe proteoglycan-induced spondylitis (PGISp) mouse model in which we have previously demonstrated downregulated SOST expression, was used for this study. Mice were injected with 2.5ug rSOST/day for a period of 8 weeks following induction of disease. Axial skeleton disease development was assessed by histology and skeletal changes examined using DEXA.ResultsrSOST treatment had no effect on peripheral or axial disease development, bone density or disease severity. Injected rSOST was stable over 8 h and residual levels were evident 24 h after injection, resulting in a cumulative increase in SOST serum levels over the treatment time course. Immunohistochemical examination of SOST levels within the joints in non-rSOST treated PGISp mice showed a significant decrease in the percentage of positive osteocytes in the unaffected joints compared to the affected joints, while no difference was seen in rSOST treated mice. This suggests that rSOST treatment increases the number of SOST-positive osteocytes in unaffected joints but not affected joints, despite having no impact on the number of joints affected by disease.ConclusionsAlthough not disease-modifying, rSOST treatment did appear to regulate SOST levels in the joints suggesting biological activity. Further dose response studies are required and SOST may require modifications to improve its bone targeting ability in order to affect tissue formation to a meaningful level in this model.

Background Optimal management of cirrhosis is complex, and patients often lack knowledge and skills, which can affect self-management. We assessed patient knowledge about cirrhosis and examined whether knowledge was associated with clinical outcomes, healthcare service use, and healthcare costs. A cross-sectional ‘knowledge survey’ was conducted during 2018–2020. We assessed patient knowledge about cirrhosis and explore whether knowledge was associated with clinical outcomes, healthcare service use, and costs. Methods Patients with cirrhosis (n = 123) completed a ‘knowledge survey’. We calculated the proportion of correct answers to eight questions deemed to be “key knowledge” about cirrhosis by an expert panel, and dichotomized patients as ‘good knowledge’/‘poor knowledge’. Clinical data, healthcare costs, and health-related quality of life (SF-36) were available. Results 58.5% of patients had ‘good knowledge’ about cirrhosis. Higher education level was associated with higher odds of having ‘good knowledge’ about cirrhosis (adjusted-OR = 5.55, 95%CI 2.40–12.84). Compared to patients with ‘poor knowledge’, those with ‘good knowledge’ had a higher health status in the SF-36 physical functioning domain (p = 0.011), fewer cirrhosis-related admissions (adjusted incidence rate ratio [IRR] = 0.59, 95%CI 0.35–0.99) and emergency presentations (adj-IRR = 0.34, 95%CI 0.16–0.72), and more planned 1-day cirrhosis admissions (adj-IRR = 3.96, 95%CI 1.46–10.74). The total cost of cirrhosis admissions was lower for patients with ‘good knowledge’ (adj-IRR = 0.30, 95%CI 0.29–0.30). Conclusion Poor disease knowledge is associated with increased use and total cost of healthcare services. Targeted educational interventions to improve patient knowledge may be an effective strategy to promote a more cost-effective use of healthcare services.

Background: Optimal management of cirrhosis is complex, and patients often lack knowledge and skills, which can affect self-management. We assessed patient knowledge about cirrhosis and examined whether knowledge was associated with clinical outcomes, healthcare service use, and healthcare costs. A cross-sectional ‘knowledge survey’ was conducted during 2018-2We assessed patient knowledge about cirrhosis and explore whether knowledge was associated with clinical outcomes, healthcare service use, and costs. METHODS: Patients with cirrhosis (n=123) completed a ‘knowledge survey’. We calculated the proportion of correct answers to eight questions deemed to be “key knowledge” about cirrhosis by an expert panel, and dichotomized patients as ‘good knowledge’/‘poor knowledge’. Clinical data, healthcare costs, and health-related quality of life (SF-36) were available. RESULTS: 58.5% of patients had ‘good knowledge’ about cirrhosis. Higher education level was associated with higher odds of having ‘good knowledge’ about cirrhosis (adjusted-OR=5.55, 95%CI 2.40-12.84). Compared to patients with ‘poor knowledge’, those with ‘good knowledge’ had a higher health status in the SF-36 physical functioning domain (p=0.011), fewer cirrhosis-related admissions (adjusted incidence rate ratio [IRR]=0.59, 95%CI 0.35-0.99) and emergency presentations (adj-IRR=0.34, 95%CI 0.16-0.72), and more planned one-day cirrhosis admissions (adj-IRR=3.96, 95%CI 1.46-10.74). The total cost of cirrhosis admissions was lower for patients with ‘good knowledge’ (adj-IRR=0.30, 95%CI 0.29-0.30).Conclusion: Poor disease knowledge is associated with increased use and total cost of healthcare services. Targeted educational interventions to improve patient knowledge may be an effective strategy to promote a more cost-effective use of healthcare services.

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