Mosaic loss of chromosome Y (LOY) in circulating white blood cells is the most common form of clonal mosaicism 1-5 , yet our knowledge of the causes and consequences of this is limited. Using a newly developed approach, we estimate that 20% of the UK Biobank male population (N=205,011) has detectable LOY. We identify 156 autosomal genetic determinants of LOY, which we replicate in 757,114 men of European and Japanese ancestry. These loci highlight genes involved in cell-cycle regulation, cancer susceptibility, somatic drivers of tumour growth and cancer therapy targets. We demonstrate that genetic susceptibility to LOY is associated with nonhaematological health outcomes in both men and women, supporting the hypothesis that clonal haematopoiesis is a biomarker of genome instability in other tissues. Single-cell RNA sequencing identifies dysregulated autosomal gene expression in leukocytes with LOY, providing insights into why clonal expansion of these cells may occur. Collectively, these data highlight the utility of studying clonal mosaicism to uncover fundamental mechanisms underlying cancer and other ageing-related diseases. Users may view, print, copy, and download text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use:

Epidemiological investigations show that mosaic loss of chromosome Y (LOY) in leukocytes is associated with earlier mortality and morbidity from many diseases in men. LOY is the most common acquired mutation and is associated with aberrant clonal expansion of cells, yet it remains unclear whether this mosaicism exerts a direct physiological effect. We studied DNA and RNA from leukocytes in sorted- and single-cells in vivo and in vitro. DNA analyses of sorted cells showed that men diagnosed with Alzheimer’s disease was primarily affected with LOY in NK cells whereas prostate cancer patients more frequently displayed LOY in CD4 + T cells and granulocytes. Moreover, bulk and single-cell RNA sequencing in leukocytes allowed scoring of LOY from mRNA data and confirmed considerable variation in the rate of LOY across individuals and cell types. LOY-associated transcriptional effect (LATE) was observed in ~ 500 autosomal genes showing dysregulation in leukocytes with LOY. The fraction of LATE genes within specific cell types was substantially larger than the fraction of LATE genes shared between different subsets of leukocytes, suggesting that LOY might have pleiotropic effects. LATE genes are involved in immune functions but also encode proteins with roles in other diverse biological processes. Our findings highlight a surprisingly broad role for chromosome Y, challenging the view of it as a “genetic wasteland”, and support the hypothesis that altered immune function in leukocytes could be a mechanism linking LOY to increased risk for disease.

PolyA (pA) tail binding proteins (PABPs) control mRNA polyadenylation, stability and translation. In a purified system, S. cerevisiae PABPs, Pab1p and Nab2p, are individually sufficient to provide normal pA tail length. However, it is unknown how this occurs in more complex environments. Here we find that the nuclear exosome subunit Rrp6p counteracts the in vitro and in vivo extension of mature pA tails by the non-canonical pA polymerase Trf4p. Moreover, PABP loading onto nascent pA tails is controlled by Rrp6p; while Pab1p is the major PABP, Nab2p only associates in the absence of Rrp6p. This is because Rrp6p can interact with Nab2p and displace it from pA tails, potentially leading to RNA turnover as evidenced for certain pre-mRNAs. We suggest that a nuclear mRNP surveillance step involves targeting of Rrp6p by Nab2p-bound pA-tailed RNPs and that pre-mRNA abundance is regulated at this level.

Polyadenylation of mRNA is a key step in eukaryotic gene expression. However, despite the major impact of poly(A) tails on mRNA metabolism, the precise roles of poly(A)-binding proteins (PABPs) in nuclear mRNA biogenesis remain elusive. Here, we demonstrate that rapid nuclear depletion of the S. cerevisiae PABP Nab2p leads to a global loss of cellular mRNA, but not of RNA lacking poly(A) tails. Disappearance of mRNA is a nuclear event, but not due to decreased transcription. Instead, the absence of Nab2p results in robust nuclear mRNA decay by the ribonucleolytic RNA exosome in a polyadenylation-dependent process. We conclude that Nab2p is required to protect early mRNA and therefore constitutes a crucial nuclear mRNA biogenesis factor.

Diabetes is one of the major challenges of modern medicine, as it is considered a global epidemic of the XXI century. The disease often leads to the development of serious, health threatening complications. Diabetic foot syndrome is a characteristic set of anatomical and molecular changes. At the macroscopic level, major symptoms are neuropathy, ischemia and chronic ulceration of the lower limb. In every third patient, the neuropathy develops into Charcot neuroarthropathy characterized by bone and joints deformation. Interestingly, all these complications are a result of impaired healing processes and are characteristic for diabetes. The specificity of these symptoms comes from impaired molecular mechanisms observed in type 1 and type 2 diabetes. Decreased wound and fracture healing reflect gene expression, cellular response, cell functioning and general metabolism. Here we present a comprehensive literature update on the molecular factors contributing to diabetic foot syndrome.

Mosaic loss of chromosome Y (LOY) in blood is linked to increased risk for morbidity and mortality in men. LOY is the most common acquired mutation and is associated with diseases such as cancer and Alzhemer's disease. We studied DNA, RNA and proteins in bulk, sorted-and single-cells in vivo and in vitro. We show that Alzheimer's disease and prostate cancer patients had more LOY in NK cells and CD4+ T-lymphocytes, respectively. Furthermore, gene expression was profoundly altered in cells with LOY in a pleiotropic fashion and autosomal genes important for normal immune cell functions showed LOY associated transcriptional effect. Proteomic analysis also indicated that LOY leaves a footprint in the plasma proteome. We provide the first mechanistic explanation for the associations between LOY in blood and risk for disease in other organs.Recent epidemiological analyses have challenged the view that LOY in blood cells is phenotypically neutral. Studies have identified increased risks for men with LOY in connection with all-cause mortality [8,9], Alzheimer's disease [10], various forms of cancer [8,[11][12][13], autoimmune conditions [14,15], age-related macular degeneration [16], cardiovascular disease [17], type 2 diabetes and obesity [9]. Furthermore, it has been known for centuries that males have a shorter life expectancy [18][19][20]. Hence, LOY as a male specific risk factor, showing reproducible associations with various common disorders, could help explaining this difference.LOY in blood is the most frequent post-zygotic mutation, detectable in 20% of the UK Biobank male population [21], reaching 40% in 80 years old males [22], and 57% in 93 years old males [23]. Furthermore, LOY is not restricted to the hematopoietic system, since it has also been described in other non-cancerous tissues, although with much lower frequencies [17,23]. Our understanding of why LOY occurs is also limited. Strong associations with age and smoking have been reported [8,10,24,25] and these factors are related to a continuously increasing mutational load throughout the genome in all somatic cells, eventually also affecting genes that are responsible for correct segregation of chromosomes. Inherited genetic predisposition for LOY has also been described [21,25,26].It is not known whether associations between LOY and increased risks for disease represent causal relationships, and if so, what the underlying mechanisms could be. The challenge that we address here is to move from epidemiological associations to mechanistic explanations on multiple levels of analysis such as DNA, mRNA and proteins. Specifically, we studied: (i) frequency of LOY in subsets of leukocytes from patients with prostate cancer (PC), Alzheimer's disease (AD) as well as controls; (ii) changes in transcriptomes of single cells and cellular subsets in bulk; and (iii) alterations of plasma protein levels in men with LOY. Different distribution of LOY in six types of sorted leukocytes among men with AD and PCStudies of associations between LOY and various outcomes hav...

Background The COVID-19 pandemic, which has a prominent social and economic impact worldwide, shows a largely unexplained male bias for the severity and mortality of the disease. Loss of chromosome Y (LOY) is a risk factor candidate in COVID-19 due to its prior association with many chronic age-related diseases, and its impact on immune gene transcription. Methods Publicly available scRNA-seq data of PBMC samples derived from male patients critically ill with COVID-19 were reanalyzed, and LOY status was added to the annotated cells. We further studied LOY in whole blood for 211 COVID-19 patients treated at intensive care units (ICU) from the first and second waves of the pandemic. Of these, 139 patients were subject to cell sorting for LOY analysis in granulocytes, low-density neutrophils (LDNs), monocytes, and PBMCs. Results Reanalysis of available scRNA-seq data revealed LDNs and monocytes as the cell types most affected by LOY. Subsequently, DNA analysis indicated that 46%, 32%, and 29% of critically ill patients showed LOY above 5% cut-off in LDNs, granulocytes, and monocytes, respectively. Hence, the myeloid lineage that is crucial for the development of severe COVID-19 phenotype is affected by LOY. Moreover, LOY correlated with increasing WHO score (median difference 1.59%, 95% HDI 0.46% to 2.71%, p=0.025), death during ICU treatment (median difference 1.46%, 95% HDI 0.47% to 2.43%, p=0.0036), and history of vessel disease (median difference 2.16%, 95% HDI 0.74% to 3.7%, p=0.004), among other variables. In 16 recovered patients, sampled during ICU stay and 93–143 days later, LOY decreased significantly in whole blood and PBMCs. Furthermore, the number of LDNs at the recovery stage decreased dramatically (median difference 76.4 per 10,000 cell sorting events, 95% HDI 55.5 to 104, p=6e−11). Conclusions We present a link between LOY and an acute, life-threatening infectious disease. Furthermore, this study highlights LOY as the most prominent clonal mutation affecting the myeloid cell lineage during emergency myelopoiesis. The correlation between LOY level and COVID-19 severity might suggest that this mutation affects the functions of monocytes and neutrophils, which could have consequences for male innate immunity.

Mosaic loss of chromosome Y (LOY) in circulating white blood cells is the most common form of clonal mosaicism, yet our knowledge of the causes and consequences of this is limited. Using a newly developed approach, we estimate that 20% of the UK Biobank male population (N=205,011) has detectable LOY. We identify 156 autosomal genetic determinants of LOY, which we replicate in 757,114 men of European and Japanese ancestry. These loci highlight genes involved in cell-cycle regulation, cancer susceptibility, somatic drivers of tumour growth and cancer therapy targets. Genetic susceptibility to LOY is associated with non-haematological health outcomes in both men and women, supporting the hypothesis that clonal haematopoiesis is a biomarker of genome instability in other tissues. Single-cell RNA sequencing identifies dysregulated autosomal gene expression in leukocytes with LOY, providing insights into how LOY may confer cellular growth advantage. Collectively, these data highlight the utility of studying clonal mosaicism to uncover fundamental mechanisms underlying cancer and other ageing-related diseases.