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Objectives: Anaemia is a key cause of morbidity in chronic kidney disease (CKD). Androgen deficiency (AD) in males can contribute to anaemia of all causes, including in CKD. We sought to examine the prevalence of AD in men with CKD, the extent to which it contributed to anaemia and whether it was independently associated with long-term survival., Methods: This cross-sectional observational study was conducted among males aged 18 years and over with CKD stages 4 and 5. The study analysed morning blood samples with regard to their full blood count, urea and electrolytes, albumin, lipids, testosterone (T) and sex hormone binding globulin, with calculation of free testosterone by mass action equation. Mortality data were obtained 15 years later for survival analysis., Results: Among 322 patients with a mean age of 63 years, the overall prevalence of AD was 68.9%. There was a statistically significant negative correlation between erythropoiesis stimulating agent (ESA) dose and testosterone concentrations (Pearson correlation -0.193, p = 0.05). There was a positive correlation between haemoglobin (Hb) and free testosterone level among patients not on ESA therapy (Pearson correlation 0.331, p < 0.001). Kaplan-Meier plots showed p < 0.001 on log-rank analysis, indicating that AD was significantly associated with worse survival. However, in Cox regression analysis, free testosterone was not associated with survival (95% CI for free testosterone 0.997-1.000)., Conclusions: AD is highly prevalent among this population, and increases further with older age and more severe CKD warranting haemodialysis. Association of lower Hb and higher ESA dose with lower T concentration might be causative, which has important pharmaco-economic as well as clinical implications. Lower survival in men with low T, more likely reflects overall poor health rather than causation. A properly constituted randomised controlled study evaluating the effect of native T replacement is warranted in men with CKD and AD., (© 2024 John Wiley & Sons Ltd.)

3-dimensional (3D) imaging is a powerful tool for interrogation of intact tissues, but can suffer from poor resolution due to impediments such as high tissue autofluorescence that remains a significant challenge in imaging cleared samples, including human clinical specimens. We developed Atacama Clear (ATC), a 3D imaging technology that increases signal-to-noise ratios (SNRs) while simultaneously augmenting the capacity of tissue to be cleared. ATC exhibited SNRs that are up to 200% of widely used 3D imaging methods, potentiated all tested optical clearing solutions by up to 600%, decreased the time of optical clearing by up to a factor of 8, and enabled detection of poorly recognized antigens with a remarkable 4-fold increase in signal detection while using up to 10-fold lower antibody concentrations. Strikingly, ATC produced up to a 5x increase in transgenic fluorescent reporter protein signal detection, which is instead often diminished with currently used 3D imaging methods. This increased imaging efficacy enabled multiplex interrogation of tough fibrous tissue and specimens that naturally exhibit high levels of background noise, including the heart, kidney, and human biopsies. Indeed, ATC facilitated the use of AI based auto-segmentation with simple low tech stereo fluorescence microscopy, visualization of previously undocumented adjacent nephron segments that exhibit notoriously high autofluorescence, elements of the cardiac conduction system, and distinct human glomerular tissue layers, with cellular resolution. Taken together, these studies establish ATC as a platform for complex 3D imaging studies of basic and clinical specimens with superior resolution.

Haploinsufficiency for GATA6 is associated with congenital heart disease (CHD) with variable comorbidity of pancreatic or diaphragm defects, although the etiology of disease is not well understood. Here, we used cardiac directed differentiation from human embryonic stem cells (hESCs) as a platform to study GATA6 function during early cardiogenesis. GATA6 loss-of-function hESCs had a profound impairment in cardiac progenitor cell (CPC) specification and cardiomyocyte (CM) generation due to early defects during the mesendoderm and lateral mesoderm patterning stages. Profiling by RNA-seq and CUT&RUN identified genes of the WNT and BMP programs regulated by GATA6 during early mesoderm patterning. Furthermore, interactome analysis detected GATA6 binding with developmental transcription factors and chromatin remodelers suggesting cooperative regulation of cardiac lineage gene accessibility. We show that modulating WNT and BMP inputs during the first 48 hours of cardiac differentiation is sufficient to partially rescue CPC and CM defects in GATA6 heterozygous and homozygous mutant hESCs. This study provides evidence of the regulatory functions for GATA6 directing human precardiac mesoderm patterning during the earliest stages of cardiogenesis to further our understanding of haploinsufficiency causing CHD and the co-occurrence of cardiac and other organ defects caused by human GATA6 mutations., Competing Interests: Competing interests T.E. is a co-founder of OncoBeat, LLC.

Epileptic encephalopathies are severe epilepsy syndromes characterized by early onset and progressive cerebral dysfunction. A nonsense variant in the DALR anticodon binding domain containing 3 (DALRD3) gene has been implicated in epileptic encephalopathy, but no other disease-associated variants in DALRD3 have been described. In human cells, the DALRD3 protein forms a complex with the METTL2 methyltransferase to generate the 3-methylcytosine (m3C) modification in specific arginine tRNAs. Here, we identify an individual with a homozygous missense variant in DALRD3 who displays developmental delay, cognitive deficiencies, and multifocal epilepsy. The missense variant substitutes an arginine residue to cysteine (R517C) within the DALR domain of the DALRD3 protein that is required for binding tRNAs. Cells derived from the individual homozygous for the DALRD3-R517C variant exhibit reduced levels of m3C modification in arginine tRNAs, indicating that the R517C variant impairs DALRD3 function. Notably, the DALRD3-R517C protein displays reduced association with METTL2 and loss of interaction with substrate tRNAs. Our results uncover another loss-of-function variant in DALRD3 linked to epileptic encephalopathy disorders. Importantly, these findings underscore DALRD3-dependent tRNA modification as a key contributor to proper brain development and function., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)