Book reviews

Teaching/Communication/Extension/Profession,

Small heat-shock proteins interact with a flanking domain to suppress polyglutamine aggregation

Small heat-shock proteins (sHsps) are molecular chaperones that play an important protective role against cellular protein misfolding by interacting with partially unfolded proteins on their off-folding pathway, preventing their aggregation. Polyglutamine (polyQ) repeat expansion leads to the formation of fibrillar protein aggregates and neuronal cell death in nine diseases, including Huntington disease and the spinocerebellar ataxias (SCAs). There is evidence that sHsps have a role in suppression of polyQ-induced neurodegeneration; for example, the sHsp alphaB-crystallin (αB-c) has been identified as a suppressor of SCA3 toxicity in a Drosophila model. However, the molecular mechanism for this suppression is unknown. In this study we tested the ability of αB-c to suppress the aggregation of a polyQ protein. We found that αB-c does not inhibit the formation of SDS-insoluble polyQ fibrils. We further tested the effect of αB-c on the aggregation of ataxin-3, a polyQ protein that aggregates via a two-stage aggregation mechanism. The first stage involves association of the N-terminal Josephin domain followed by polyQ-mediated interactions and the formation of SDS-resistant mature fibrils. Our data show that αB-c potently inhibits the first stage of ataxin-3 aggregation; however, the second polyQ-dependent stage can still proceed. By using NMR spectroscopy, we have determined that αB-c interacts with an extensive region on the surface of the Josephin domain. These data provide an example of a domain/region flanking an amyloidogenic sequence that has a critical role in modulating aggregation of a polypeptide and plays a role in the interaction with molecular chaperones to prevent this aggregation

Emerging biological archives can reveal ecological and climatic change in Antarctica

Anthropogenic climate change is causing observable changes in Antarctica and the Southern Ocean including increased air and ocean temperatures, glacial melt leading to sea-level rise and a reduction in salinity, and changes to freshwater water availability on land. These changes impact local Antarctic ecosystems and the Earth's climate system. The Antarctic has experienced significant past environmental change, including cycles of glaciation over the Quaternary Period (the past similar to 2.6 million years), Understanding Antarctica's paleoecosystems, and the corresponding paleoenvironments and climates that have shaped them, provides insight into present day ecosystem change, and importantly, helps constrain model projections of future change. Biological archives such as extant moss beds and peat profiles, biological proxies in lake and marine sediments, vertebrate animal colonies, and extant terrestrial and benthic marine invertebrates, complement other Antarctic paleoclimate archives by recording the nature and rate of past ecological change, the paleoenvironmental drivers of that change, and constrain current ecosystem and climate models. These archives provide invaluable information about terrestrial ice-free areas, a key location for Antarctic biodiversity, and the continental margin which is important for understanding ice sheet dynamics. Recent significant advances in analytical techniques (e.g., genomics, biogeochemical analyses) have led to new applications and greater power in elucidating the environmental records contained within biological archives. Paleoecological and paleoclimate discoveries derived from biological archives, and integration with existing data from other paleoclimate data sources, will significantly expand our understanding of past, present, and future ecological change, alongside climate change, in a unique, globally significant region

Rituximab versus intravenous cyclophosphamide in patients with connective tissue disease-associated interstitial lung disease in the UK (RECITAL): a double-blind, double-dummy, randomised, controlled, phase 2b trial

BACKGROUND: Rituximab is often used as rescue therapy in interstitial lung disease (ILD) associated with connective tissue disease (CTD), but has not been studied in clinical trials. This study aimed to assess whether rituximab is superior to cyclophosphamide as a treatment for severe or progressive CTD associated ILD. METHODS: We conducted a randomised, double-blind, double-dummy, phase 2b trial to assess the superiority of rituximab compared with cyclophosphamide. Patients aged 18-80 years with severe or progressive ILD related to scleroderma, idiopathic inflammatory myositis, or mixed CTD, recruited across 11 specialist ILD or rheumatology centres in the UK, were randomly assigned (1:1) to receive rituximab (1000 mg at weeks 0 and 2 intravenously) or cyclophosphamide (600 mg/m2 body surface area every 4 weeks intravenously for six doses). The primary endpoint was rate of change in forced vital capacity (FVC) at 24 weeks compared with baseline, analysed using a mixed-effects model with random intercepts, adjusted for baseline FVC and CTD type. Prespecified secondary endpoints reported in this Article were change in FVC at 48 weeks versus baseline; changes from baseline in 6 min walk distance, diffusing capacity of the lung for carbon monoxide (DLCO), physician-assessed global disease activity (GDA) score, and quality-of-life scores on the St George's Respiratory Questionnaire (SGRQ), King's Brief Interstitial Lung Disease (KBILD) questionnaire, and European Quality of Life Five-Dimension (EQ-5D) questionnaire at 24 and 48 weeks; overall survival, progression-free survival, and time to treatment failure; and corticosteroid use. All endpoints were analysed in the modified intention-to-treat population, which comprised all patients who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov (NCT01862926). FINDINGS: Between Dec 1, 2014, and March 31, 2020, we screened 145 participants, of whom 101 participants were randomly allocated: 50 (50%) to receive cyclophosphamide and 51 (50%) to receive rituximab. 48 (96%) participants in the cyclophosphamide group and 49 (96%) in the rituximab group received at least one dose of treatment and were included in analyses; 43 (86%) participants in the cyclophosphamide group and 42 (82%) participants in the rituximab group completed 24 weeks of treatment and follow-up. At 24 weeks, FVC was improved from baseline in both the cyclophosphamide group (unadjusted mean increase 99 mL [SD 329]) and the rituximab group (97 mL [234]); in the adjusted mixed-effects model, the difference in the primary endpoint at 24 weeks was -40 mL (95% CI -153 to 74; p=0·49) between the rituximab group and the cyclophosphamide group. KBILD quality-of-life scores were improved at 24 weeks by a mean 9·4 points (SD 20·8) in the cyclophosphamide group and 8·8 points (17·0) in the rituximab group. No significant differences in secondary endpoints were identified between the treatment groups, with the exception of change in GDA score at week 48, which favoured cyclophosphamide (difference 0·90 [95% CI 0·11 to 1·68]). Improvements in lung function and respiratory-related quality-of-life measures were observed in both treatment groups. Lower corticosteroid exposure over 48 weeks of follow-up was recorded in the rituximab group. Two (4%) of 48 participants who received cyclophosphamide and three (6%) of 49 who received rituximab died during the study, all due to complications of CTD or ILD. Overall survival, progression-free survival, and time to treatment failure did not significantly differ between the two groups. All participants reported at least one adverse event during the study. Numerically fewer adverse events were reported by participants receiving rituximab (445 events) than those receiving cyclophosphamide (646 events). Gastrointestinal and respiratory disorders were the most commonly reported adverse events in both groups. There were 62 serious adverse events of which 33 occurred in the cyclophosphamide group and 29 in the rituximab group. INTERPRETATION: Rituximab was not superior to cyclophosphamide to treat patients with CTD-ILD, although participants in both treatment groups had increased FVC at 24 weeks, in addition to clinically important improvements in patient-reported quality of life. Rituximab was associated with fewer adverse events. Rituximab should be considered as a therapeutic alternative to cyclophosphamide in individuals with CTD-ILD requiring intravenous therapy. FUNDING: Efficacy and Mechanism Evaluation Programme (Medical Research Council and National Institute for Health Research, UK)

Rituximab compared to intravenous cyclophosphamide in adults with connective tissue disease-associated interstitial lung disease: the RECITAL RCT

BACKGROUND: Interstitial lung disease frequently complicates systemic autoimmune disorders including scleroderma, idiopathic inflammatory myositis and mixed connective tissue disease, resulting in considerable morbidity and mortality. Based on the results of trials undertaken in scleroderma, cyclophosphamide is the standard of care for individuals with severe or progressive connective tissue disease-associated interstitial lung disease. Observational studies suggest that the anti-CD20 monoclonal antibody, rituximab is an effective rescue therapy in treatment of refractory connective tissue disease-associated interstitial lung disease, but it has not been studied as first-line therapy in clinical trials. OBJECTIVES: To compare the safety and efficacy of rituximab against that of cyclophosphamide as treatment for individuals with severe, progressive interstitial lung disease associated with scleroderma, idiopathic inflammatory myositis or mixed connective tissue disease. METHODS: This was a Phase IIb, multicentre, randomised, double-blind, double-dummy study assessing the superiority of rituximab compared with cyclophosphamide, conducted in rheumatology or interstitial lung disease units at 11 UK centres. The study recruited individuals with extensive and/or progressive connective tissue disease-associated interstitial lung disease, excluding those with significant comorbidities, including airflow obstruction. Participants were randomised 1 : 1 to receive either rituximab 1 g given intravenously, twice at an interval of 2 weeks, or intravenous cyclophosphamide given monthly for 6 months at a dose of 600 mg/m2 body surface area. The primary end point for the study was the change in forced vital capacity at 24 weeks. Secondary end points included safety and tolerability, corticosteroid exposure, forced vital capacity change at 48 weeks and patient-reported quality of life. A cost-effectiveness analysis was undertaken to assess the impact of rituximab use in the United Kingdom National Health Service. RESULTS: One hundred and one subjects (70 females) with a mean age of 56.3 years were randomised; 51 to rituximab and 50 to cyclophosphamide. Ninety-seven were included in the modified intention-to-treat population for the primary and secondary efficacy analyses (49 in the rituximab group and 48 in the cyclophosphamide group). 38.6% had scleroderma, 44.6% idiopathic inflammatory myositis and 16.8% mixed connective tissue disease. Four subjects withdrew prior to the first dose of therapy (two in each arm). At 24 weeks, both rituximab and cyclophosphamide improved forced vital capacity from baseline [(mean ± standard deviation) 97 ± 234 and 99 ± 329 ml, respectively]. Using an adjusted mixed-effects model corrected for diagnosis and baseline forced vital capacity the difference in forced vital capacity at 24 weeks between rituximab and cyclophosphamide was −40 ml (95% CI −153 to 74 ml), p = 0.49. Other physiological and quality-of-life parameters improved in both arms following treatment but were not statistically significantly different between groups. Numerically fewer adverse events were reported by subjects receiving rituximab. Corticosteroid exposure over the 48 weeks of the trial was numerically less in the rituximab arm [13,291 (±14,657) mg of hydrocortisone equivalent per subject in the cyclophosphamide arm versus 11,469 (±10,041) mg per subject in the rituximab group; these differences did not reach statistical significance]. Limitations of the study include a disproportionate number of subjects being recruited from a single centre and insufficient subjects in each subgroup to determine whether there were treatment differences between individual connective tissue diseases. Based on the results of the trial, from a UK healthcare payer perspective, rituximab is more cost-effective than cyclophosphamide as a treatment for severe or progressive connective tissue disease-interstitial lung disease. CONCLUSIONS: Rituximab improved forced vital capacity and patient-reported quality of life at 24 weeks but was not superior to cyclophosphamide. Rituximab should be considered as a therapeutic alternative to cyclophosphamide in individuals with connective tissue disease-associated interstitial lung disease requiring systemic therapy. Future work should explore the role of repeated dosing of rituximab and the use of rituximab earlier in the course of connective tissue disease-associated interstitial lung disease

Apolipoprotein CIII and N-terminal prohormone b-type natriuretic peptide as independent predictors for cardiovascular disease in type 2 diabetes

Background and aims: Developing sparse panels of biomarkers for cardiovascular disease in type 2 diabetes would enable risk stratification for clinical decision making and selection into clinical trials. We examined the individual and joint performance of five candidate biomarkers for incident cardiovascular disease (CVD) in type 2 diabetes that an earlier discovery study had yielded. Methods: Apolipoprotein CIII (apoCIII), N-terminal prohormone B-type natriuretic peptide (NT-proBNP), high sensitivity Troponin T (hsTnT), Interleukin-6, and Interleukin-15 were measured in baseline serum samples from the Collaborative Atorvastatin Diabetes trial (CARDS) of atorvastatin versus placebo. Among 2105 persons with type 2 diabetes and median age of 62.9 years (range 39.2–77.3), there were 144 incident CVD (acute coronary heart disease or stroke) cases during the maximum 5-year follow up. We used Cox Proportional Hazards models to identify biomarkers associated with incident CVD and the area under the receiver operating characteristic curves (AUROC) to assess overall model prediction. Results: Three of the biomarkers were singly associated with incident CVD independently of other risk factors; NT-proBNP (Hazard Ratio per standardised unit 2.02, 95% Confidence Interval [CI] 1.63, 2.50), apoCIII (1.34, 95% CI 1.12, 1.60) and hsTnT (1.40, 95% CI 1.16, 1.69). When combined in a single model, only NT-proBNP and apoCIII were independent predictors of CVD, together increasing the AUROC using Framingham risk variables from 0.661 to 0.745. Conclusions: The biomarkers NT-proBNP and apoCIII substantially increment the prediction of CVD in type 2 diabetes beyond that obtained with the variables used in the Framingham risk score

Personalized recurrence risk assessment following the birth of a child with a pathogenic de novo mutation

Following the diagnosis of a paediatric disorder caused by an apparently de novo mutation, a recurrence risk of 1–2% is frequently quoted due to the possibility of parental germline mosaicism; but for any specific couple, this figure is usually incorrect. We present a systematic approach to providing individualized recurrence risk. By combining locus-specific sequencing of multiple tissues to detect occult mosaicism with long-read sequencing to determine the parent-of-origin of the mutation, we show that we can stratify the majority of couples into one of seven discrete categories associated with substantially different risks to future offspring. Among 58 families with a single affected offspring (representing 59 de novo mutations in 49 genes), the recurrence risk for 35 (59%) was decreased below 0.1%, but increased owing to parental mixed mosaicism for 5 (9%)—that could be quantified in semen for paternal cases (recurrence risks of 5.6–12.1%). Implementation of this strategy offers the prospect of driving a major transformation in the practice of genetic counselling

Fine-mapping identifies multiple prostate cancer risk loci at 5p15, one of which associates with TERT expression

Associations between single nucleotide polymorphisms (SNPs) at 5p15 and multiple cancer types have been reported. We have previously shown evidence for a strong association between prostate cancer (PrCa) risk and rs2242652 at 5p15, intronic in the telomerase reverse transcriptase (TERT) gene that encodes TERT. To comprehensively evaluate the association between genetic variation across this region and PrCa, we performed a fine-mapping analysis by genotyping 134 SNPs using a custom Illumina iSelect array or Sequenom MassArray iPlex, followed by imputation of 1094 SNPs in 22 301 PrCa cases and 22 320 controls in The PRACTICAL consortium. Multiple stepwise logistic regression analysis identified four signals in the promoter or intronic regions of TERT that independently associated with PrCa risk. Gene expression analysis of normal prostate tissue showed evidence that SNPs within one of these regions also associated with TERT expression, providing a potential mechanism for predisposition to disease