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Dr Sparrow has published a new paper in collaboration with the Victor Chang Cardiac Research Institute entitled "Gene-environment interaction impacts on heart development and embryo survival."
Native Top-Down Mass Spectrometry Reveals a Role for Interfacial Glycans on Therapeutic Cytokine and Hormone Assemblies.
Oligomerization and glycosylation modulate therapeutic glycoprotein stability and efficacy. The interplay between these two critical attributes on therapeutic glycoproteins, is however often hard to define. Here, we present a native top-down mass spectrometry (MS) approach to assess the glycosylation status of therapeutic cytokine and hormone assemblies and relate interfacial glycan occupancy to complex stability. We found that interfacial O-glycan stabilizes tumor necrosis factor-α trimer. On the contrary, interferon-β1a dimerization is independent of glycosylation. Moreover, we discovered a unique distribution of N-glycans on the follicle-stimulating hormone α subunit. We found that the interfacial N-glycan, at Asn52 of the α subunit, interacts extensively with the β subunit to regulate the dimer assembly. Overall, we have exemplified a method to link glycosylation with assembly status, for cytokines and hormones, critical for informing optimal stability and bioavailability.
Noise suppression of proton magnetic resonance spectroscopy improves paediatric brain tumour classification.
Proton magnetic resonance spectroscopy (1 H-MRS) is increasingly used for clinical brain tumour diagnosis, but suffers from limited spectral quality. This retrospective and comparative study aims at improving paediatric brain tumour classification by performing noise suppression on clinical 1 H-MRS. Eighty-three/forty-two children with either an ependymoma (ages 4.6 ± $$ \pm $$ 5.3/9.3 ± $$ \pm $$ 5.4), a medulloblastoma (ages 6.9 ± $$ \pm $$ 3.5/6.5 ± $$ \pm $$ 4.4), or a pilocytic astrocytoma (8.0 ± $$ \pm $$ 3.6/6.3 ± $$ \pm $$ 5.0), recruited from four centres across England, were scanned with 1.5T/3T short-echo-time point-resolved spectroscopy. The acquired raw 1 H-MRS was quantified by using Totally Automatic Robust Quantitation in NMR (TARQUIN), assessed by experienced spectroscopists, and processed with adaptive wavelet noise suppression (AWNS). Metabolite concentrations were extracted as features, selected based on multiclass receiver operating characteristics, and finally used for identifying brain tumour types with supervised machine learning. The minority class was oversampled through the synthetic minority oversampling technique for comparison purposes. Post-noise-suppression 1 H-MRS showed significantly elevated signal-to-noise ratios (P < .05, Wilcoxon signed-rank test), stable full width at half-maximum (P > .05, Wilcoxon signed-rank test), and significantly higher classification accuracy (P < .05, Wilcoxon signed-rank test). Specifically, the cross-validated overall and balanced classification accuracies can be improved from 81% to 88% overall and 76% to 86% balanced for the 1.5T cohort, whilst for the 3T cohort they can be improved from 62% to 76% overall and 46% to 56%, by applying Naïve Bayes on the oversampled 1 H-MRS. The study shows that fitting-based signal-to-noise ratios of clinical 1 H-MRS can be significantly improved by using AWNS with insignificantly altered line width, and the post-noise-suppression 1 H-MRS may have better diagnostic performance for paediatric brain tumours.
Oncogenic cell tagging and single-cell transcriptomics reveal cell type-specific and time-resolved responses to Vhl inactivation in the kidney.
Defining the initial events in oncogenesis and the cellular responses they entrain, even in advance of morphological abnormality, is a fundamental challenge in understanding cancer initiation. As a paradigm to address this, we longitudinally studied the changes induced by loss of the tumor suppressor gene von Hippel Lindau (VHL), which ultimately drives clear cell renal cell carcinoma. Vhl inactivation was directly coupled to expression of a tdTomato reporter within a single allele, allowing accurate visualization of affected cells in their native context and retrieval from the kidney for single-cell RNA-sequencing. This strategy uncovered cell-type specific responses to Vhl inactivation, defined a proximal tubular cell class with oncogenic potential, and revealed longer term adaptive changes in the renal epithelium and the interstitium. Oncogenic cell tagging also revealed markedly heterogeneous cellular effects including time-limited proliferation and elimination of specific cell types. Overall, this study reports an experimental strategy for understanding oncogenic processes in which cells bearing genetic alterations can be generated in their native context, marked, and analyzed over time. The observed effects of loss of Vhl in kidney cells provide insights into VHL tumor suppressor action and development of renal cell carcinoma.
Lung Ultrasound Reproducibly Outperforms Computed Tomography in the Detection of Extravascular Lung Water in Patients Undergoing Haemodialysis
Background: Lung ultrasound (LUS) is increasingly used as an extension of physical examination, informing clinical diagnosis, and decision making. There is particular interest in the assessment of patients with pulmonary congestion and extravascular lung water, although gaps remain in the evidence base underpinning this practice as a result of the limited evaluation of its inter-rater reliability and comparison with more established radiologic tests. Methods: 30 patients undergoing haemodialysis were prospectively recruited to an observational cohort study (NCT01949402). Patients underwent standardised LUS assessment before, during and after haemodialysis; their total LUS B-line score was generated, alongside a binary label of whether appearances were consistent with an interstitial syndrome. LUS video clips were recorded and independently scored by two blinded expert clinician sonographers. Low-dose non-contrast thoracic CT, pre- and post dialysis, was used as a “gold standard” radiologic comparison. Results: LUS detected a progressive reduction in B-line scores in almost all patients undergoing haemodialysis, correlating with the volume of fluid removed once individuals with no or minimal B-lines upon pre-dialysis examination were discounted. When comparing CT scans pre- and post dialysis, radiologic evidence of the change in fluid status was only identified in a single patient. Conclusions: This is the first study to demonstrate that LUS detects changes in extravascular lung water caused by changing fluid status during haemodialysis using a blinded outcome assessment and that LUS appears to be more sensitive than CT for this purpose. Further research is needed to better understand the role of LUS in this and similar patient populations, with the aim of improving clinical care and outcomes.
Treating Hypertension: Important for Heart Health, Fundamental for Brain Health.
The Brain Health crisis stands as one of humankind's most pressing threats, with age-related noncommunicable brain diseases, particularly stroke, and dementia, affecting hundreds of millions annually and jeopardizing the economic well-being of populations worldwide. Epidemiological studies indicate that ≈40% of dementia and 60% of stroke cases are attributable to modifiable risk factors. In this Comments and Opinions article, we underscore the pivotal role of blood pressure (BP) control in reducing suffering, enhancing economic well-being, and promoting healthy longevity for populations worldwide. Emphasizing that BP control is crucial for both brain and heart health, it advocates for heightened awareness, positioning hypertension as a primary focus for preventing dementia and stroke with potential global impact. Despite its significance, BP control encounters global challenges, with proportions of the population maintaining adequately controlled hypertension ranging from 23% to 90%. The World Health Organization estimated that 46% of the 1.28 billion people with hypertension are unaware of their elevated BP. Given the notable disparities in BP management, addressing BP management also contributes to combating significant health inequalities. The next time you are faced with a patient anxious about the prospect of experiencing a fate similar to a parent with dementia or a sister with a stroke, we suggest a straightforward answer for health care providers: start ensuring BP control. BP is a matter of brain health, and it is a matter of our economic future.
[A prospective cohort study of factors associated with longevity in older adults in 10 areas of China].
Objective: To evaluate the associations of sociodemographic characteristics and lifestyle factors with longevity status in older adults in China. Methods: After excluding those born after 31st December 1938, a total of 51 870 older adults from the China Kadoorie Biobank (CKB) were included. The attained age was defined according to the survival age or age on 31st December 2018. According to the attained age, the old persons were categorized into non-longevity (died before age 80 years) and longevity (attained age ≥80 years). The longevity group was further divided into two groups: longevity with death occurring before 2019, and longevity and survival to 2019. The information about socio-demographic characteristics and lifestyles was collected at the 2004-2008 baseline survey. Multinomial logistic regression models were used to analyze the associations between exposure factors and outcomes by taking the non-longevity group as the reference group. Results: A total of 51 870 older adults aged 65-79 years in the baseline survey were included for analysis. During a follow-up for (10.2±3.5) years, 38 841 participants were longevity, and 30 354 participants still survived at the end of 2018. Compared to men, rural populations, non-married individuals, those with an annual household income of less than 10 000 yuan, and those with education levels of primary school or below, the adjusted ORs(95%CI) for longevity and survival to 2019 in women, urban residents, married individuals, those with annual household incomes ≥20 000 yuan, and those with education levels of college or university were 1.68 (1.58-1.78), 1.69 (1.61-1.78), 1.15 (1.10-1.21), 1.44 (1.36-1.53), and 1.32 (1.19-1.48), respectively. The OR (95%CI) for longevity and survival to 2019 was 1.09 (1.08-1.10) for those with an increase of 4 MET-hour/day in total physical activity level. With those who never or almost never smoked, had no alcohol drinking every week, had normal weight (BMI: 18.5-23.9 kg/m2), and WC <85 cm (man)/<80 cm (woman) as the reference groups, the ORs(95%CI) of longevity and survival to 2019 were 0.64 (0.60-0.69) for those smoking ≥20 cigarettes per day, 1.29 (1.14-1.46) for those with alcohol drinking every week, 1.13 (1.01-1.26) for those with pure alcohol drinking <30 g per day, 0.56 (0.52-0.61) for those being underweight, 1.27 (1.19-1.36) for those being overweight, 1.23 (1.11-1.36) for those with obesity, and 0.86 (0.79-0.93) for those with central obesity. Further stratified analysis by WC was performed. In the older adults with WC <85 cm (man)/<80 cm (woman), the ORs (95%CI) of longevity and survival was 1.80 (1.69-1.92) for those with each 5 kg/m2 increase in BMI and 1.02 (0.96-1.08) for those with WC ≥85 cm (man)/≥80 cm (woman). There was a statistically significant difference in the association between BMI and longevity between the two WC groups (interaction test P<0.001). Conclusion: This study showed that women, the married, those with higher socioeconomic status and education level, and those with healthy lifestyles were more likely to achieve longevity.
Drug repurposing screen identifies novel anti-inflammatory activity of sunitinib in macrophages.
Inflammation is a driver of human disease and an unmet clinical need exists for new anti-inflammatory medicines. As a key cell type in both acute and chronic inflammatory pathologies, macrophages are an appealing therapeutic target for anti-inflammatory medicines. Drug repurposing - the use of existing medicines for novel indications - is an attractive strategy for the identification of new anti-inflammatory medicines with reduced development costs and lower failure rates than de novo drug discovery. In this study, FDA-approved medicines were screened in a murine macrophage NF-κB reporter cell line to identify potential anti-inflammatory drug repurposing candidates. The multi-tyrosine kinase inhibitor sunitinib was found to be a potent inhibitor of NF-κB activity and suppressor of inflammatory mediator production in murine bone marrow derived macrophages. Furthermore, oral treatment with sunitinib in mice was found to reduce TNFα production, inflammatory gene expression and organ damage in a model of endotoxemia via inhibition of NF-κB. Finally, we revealed sunitinib to have immunomodulatory effects in a model of chronic cardiovascular inflammation by reducing circulating TNFα. This study validates drug repurposing as a strategy for the identification of novel anti-inflammatory medicines and highlights sunitinib as a potential drug repurposing candidate for inflammatory disease via inhibition of NF-κB signalling.
The TMEM16A channel as a potential therapeutic target in vascular disease.
PURPOSE OF REVIEW: The transmembrane protein 16A (TMEM16A) Ca 2+ -activated Cl - channel constitutes a key depolarising mechanism in vascular smooth muscle and contractile pericytes, while in endothelial cells the channel is implicated in angiogenesis and in the response to vasoactive stimuli. Here, we offer a critical analysis of recent physiological investigations and consider the potential for targeting TMEM16A channels in vascular disease. RECENT FINDINGS: Genetic deletion or pharmacological inhibition of TMEM16A channels in vascular smooth muscle decreases artery tone and lowers systemic blood pressure in rodent models. Inhibition of TMEM16A channels in cerebral cortical pericytes protects against ischemia-induced tissue damage and improves microvascular blood flow in rodent stroke models. In endothelial cells, the TMEM16A channel plays varied roles including modulation of cell division and control of vessel tone through spread of hyperpolarisation to the smooth muscle cells. Genetic studies implicate TMEM16A channels in human disease including systemic and pulmonary hypertension, stroke and Moyamoya disease. SUMMARY: The TMEM16A channel regulates vascular function by controlling artery tone and capillary diameter as well as vessel formation and histology. Preclinical and clinical investigations are highlighting the potential for therapeutic exploitation of the channel in a range of maladaptive states of the (micro)circulation.
Executive summary of the KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease: known knowns and known unknowns
The Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease (CKD) updates the KDIGO 2012 guideline and has been developed with patient partners, clinicians, and researchers around the world, using robust methodology. This update, based on a substantially broader base of evidence than has previously been available, reflects an exciting time in nephrology. New therapies and strategies have been tested in large and diverse populations that help to inform care; however, this guideline is not intended for people receiving dialysis nor those who have a kidney transplant. The document is sensitive to international considerations, CKD across the lifespan, and discusses special considerations in implementation. The scope includes chapters dedicated to the evaluation and risk assessment of people with CKD, management to delay CKD progression and its complications, medication management and drug stewardship in CKD, and optimal models of CKD care. Treatment approaches and actionable guideline recommendations are based on systematic reviews of relevant studies and appraisal of the quality of the evidence and the strength of recommendations which followed the “Grading of Recommendations Assessment, Development, and Evaluation” (GRADE) approach. The limitations of the evidence are discussed. The guideline also provides practice points, which serve to direct clinical care or activities for which a systematic review was not conducted, and it includes useful infographics and describes an important research agenda for the future. It targets a broad audience of people with CKD and their healthcare, while being mindful of implications for policy and payment.
Iron Status and Risk of Heart Disease, Stroke, and Diabetes: A Mendelian Randomization Study in European Adults.
BACKGROUND: The relevance of iron status biomarkers for coronary artery disease (CAD), heart failure (HF), ischemic stroke (IS), and type 2 diabetes (T2D) is uncertain. We compared the observational and Mendelian randomization (MR) analyses of iron status biomarkers and hemoglobin with these diseases. METHODS AND RESULTS: Observational analyses of hemoglobin were compared with genetically predicted hemoglobin with cardiovascular diseases and diabetes in the UK Biobank. Iron biomarkers included transferrin saturation, serum iron, ferritin, and total iron binding capacity. MR analyses assessed associations with CAD (CARDIOGRAMplusC4D [Coronary Artery Disease Genome Wide Replication and Meta-Analysis Plus The Coronary Artery Disease Genetics], n=181 522 cases), HF (HERMES [Heart Failure Molecular Epidemiology for Therapeutic Targets), n=115 150 cases), IS (GIGASTROKE, n=62 100 cases), and T2D (DIAMANTE [Diabetes Meta-Analysis of Trans-Ethnic Association Studies], n=80 154 cases) genome-wide consortia. Observational analyses demonstrated J-shaped associations of hemoglobin with CAD, HF, IS, and T2D. In contrast, MR analyses demonstrated linear positive associations of higher genetically predicted hemoglobin levels with 8% higher risk per 1 SD higher hemoglobin for CAD, 10% to 13% for diabetes, but not with IS or HF in UK Biobank. Bidirectional MR analyses confirmed the causal relevance of iron biomarkers for hemoglobin. Further MR analyses in global consortia demonstrated modest protective effects of iron biomarkers for CAD (7%-14% lower risk for 1 SD higher levels of iron biomarkers), adverse effects for T2D, but no associations with IS or HF. CONCLUSIONS: Higher levels of iron biomarkers were protective for CAD, had adverse effects on T2D, but had no effects on IS or HF. Randomized trials are now required to assess effects of iron supplements on risk of CAD in high-risk older people.
Comparison of bolus versus continuous thermodilution derived indices of microvascular dysfunction in revascularized coronary syndromes
Background: The assessment of coronary microvascular dysfunction (CMD) using invasive methods is a field of growing interest, however the preferred method remains debated. Bolus and continuous thermodilution are commonly used methods, but weak agreement has been observed in patients with angina with non-obstructive coronary arteries (ANOCA). This study examined their agreement in revascularized acute coronary syndromes (ACS) and chronic coronary syndromes (CCS) patients. Objective: To compare bolus thermodilution and continuous thermodilution indices of CMD in revascularized ACS and CCS patients and assess their diagnostic agreement at pre-defined cut-off points. Methods: Patients from two centers underwent paired bolus and continuous thermodilution assessments after revascularization. CMD indices were compared between the two methods and their agreements at binary cut-off points were assessed. Results: Ninety-six patients and 116 vessels were included. The mean age was 64 ± 11 years, and 20 (21 %) were female. Overall, weak correlations were observed between the Index of Microcirculatory Resistance (IMR) and continuous thermodilution microvascular resistance (Rµ) (rho = 0.30p = 0.001). The median coronary flow reserve (CFR) from continuous thermodilution (CFRcont) and bolus thermodilution (CFRbolus) were 2.19 (1.76–2.67) and 2.55 (1.50–3.58), respectively (p < 0.001). Weak correlation and agreement were observed between CFRcont and CFRbolus (rho = 0.37, p < 0.001, ICC 0.228 [0.055–0.389]). When assessed at CFR cut-off values of 2.0 and 2.5, the methods disagreed in 41 (35 %) and 45 (39 %) of cases, respectively. Conclusions: There is a significant difference and weak agreement between bolus and continuous thermodilution-derived indices, which must be considered when diagnosing CMD in ACS and CCS patients.
A comprehensive analysis of APOE genotype effects on human brain structure in the UK Biobank.
Alzheimer's disease (AD) risk is increased in carriers of the apolipoprotein E (APOE) ε4 allele and decreased in ε2 allele carriers compared with the ε3ε3 genotype. The aim of this study was to determine whether: the APOE genotype affects brain grey (GM) or white matter (WM) structure; and if differences exist, the age when they become apparent and whether there are differential effects by sex. We used cross-sectional magnetic resonance imaging data from ~43,000 (28,494 after pre-processing) white British cognitively healthy participants (7,446 APOE ε4 carriers) aged 45-80 years from the UK Biobank cohort and investigated image-derived phenotypes (IDPs). We observed no statistically significant effects of APOE genotype on GM structure volumes or median T2* in subcortical structures, a measure related to iron content. The volume of white matter hyperintensities differed significantly between APOE genotype groups with higher volumes in APOE ε4ε4 (effect size 0.14 standard deviations [SD]) and ε3ε4 carriers (effect size 0.04 SD) but no differences in ε2 carriers compared with ε3ε3 carriers. WM integrity measures in the dorsal (mean diffusivity [MD]) and ventral cingulum (MD and intracellular volume fraction), posterior thalamic radiation (MD and isotropic volume fraction) and sagittal stratum (MD) indicated lower integrity in APOE ε4ε4 carriers (effect sizes around 0.2-0.3 SD) and ε3ε4 (effect sizes around 0.05 SD) carriers but no differences in ε2 carriers compared with the APOE ε3ε3 genotype. Effects did not differ between men and women. APOE ε4 homozygotes had lower WM integrity specifically at older ages with a steeper decline of WM integrity from the age of 60 that corresponds to around 5 years greater "brain age". APOE genotype affects various white matters measures, which might be indicative of preclinical AD processes. This hypothesis can be assessed in future when clinical outcomes become available.
Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches.
Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly.