@article {1005, title = {Constrained chromatin accessibility in PU.1-mutated agammaglobulinemia patients.}, journal = {J Exp Med}, volume = {218}, year = {2021}, month = {2021 Jul 05}, abstract = {

The pioneer transcription factor (TF) PU.1 controls hematopoietic cell fate by decompacting stem cell heterochromatin and allowing nonpioneer TFs to enter otherwise inaccessible genomic sites. PU.1 deficiency fatally arrests lymphopoiesis and myelopoiesis in mice, but human congenital PU.1 disorders have not previously been described. We studied six unrelated agammaglobulinemic patients, each harboring a heterozygous mutation (four de novo, two unphased) of SPI1, the gene encoding PU.1. Affected patients lacked circulating B cells and possessed few conventional dendritic cells. Introducing disease-similar SPI1 mutations into human hematopoietic stem and progenitor cells impaired early in vitro B cell and myeloid cell differentiation. Patient SPI1 mutations encoded destabilized PU.1 proteins unable to nuclear localize or bind target DNA. In PU.1-haploinsufficient pro-B cell lines, euchromatin was less accessible to nonpioneer TFs critical for B cell development, and gene expression patterns associated with the pro- to pre-B cell transition were undermined. Our findings molecularly describe a novel form of agammaglobulinemia and underscore PU.1{\textquoteright}s critical, dose-dependent role as a hematopoietic euchromatin gatekeeper.

}, issn = {1540-9538}, doi = {10.1084/jem.20201750}, author = {Le Coz, Carole and Nguyen, David N and Su, Chun and Nolan, Brian E and Albrecht, Amanda V and Xhani, Suela and Sun, Di and Demaree, Benjamin and Pillarisetti, Piyush and Khanna, Caroline and Wright, Francis and Chen, Peixin Amy and Yoon, Samuel and Stiegler, Amy L and Maurer, Kelly and Garifallou, James P and Rymaszewski, Amy and Kroft, Steven H and Olson, Timothy S and Seif, Alix E and Wertheim, Gerald and Grant, Struan F A and Vo, Linda T and Puck, Jennifer M and Sullivan, Kathleen E and Routes, John M and Zakharova, Viktoria and Shcherbina, Anna and Mukhina, Anna and Rudy, Natasha L and Hurst, Anna C E and Atkinson, T Prescott and Boggon, Titus J and Hakonarson, Hakon and Abate, Adam R and Hajjar, Joud and Nicholas, Sarah K and Lupski, James R and Verbsky, James and Chinn, Ivan K and Gonzalez, Michael V and Wells, Andrew D and Marson, Alex and Poon, Gregory M K and Romberg, Neil} } @article {85, title = {Recurrent recessive mutation in deoxyguanosine kinase causes idiopathic noncirrhotic portal hypertension.}, journal = {Hepatology}, volume = {63}, year = {2016}, month = {2016 06}, pages = {1977-86}, abstract = {

UNLABELLED: Despite advances in the diagnosis and management of idiopathic noncirrhotic portal hypertension, its pathogenesis remains elusive. Insight may be gained from study of early-onset familial idiopathic noncirrhotic portal hypertension, in which Mendelian mutations may account for disease. We performed exome sequencing of eight subjects from six kindreds with onset of portal hypertension of indeterminate etiology during infancy or childhood. Three subjects from two consanguineous families shared the identical rare homozygous p.N46S mutation in DGUOK, a deoxyguanosine kinase required for mitochondrial DNA replication; haplotype sharing demonstrated that the mutation in the two families was inherited from a remote common ancestor. All three affected subjects had stable portal hypertension with noncirrhotic liver disease for 6-16 years of follow-up. This mutation impairs adenosine triphosphate binding and reduces catalytic activity. Loss-of-function mutations in DGUOK have previously been implicated in cirrhosis and liver failure but not in isolated portal hypertension. Interestingly, treatment of patients with human immunodeficiency viral infection with the nucleoside analogue didanosine is known to cause portal hypertension in a subset of patients and lowers deoxyguanosine kinase levels in vitro; the current findings implicate these effects on deoxyguanosine kinase in the causal mechanism.

CONCLUSION: Our findings provide new insight into the mechanisms mediating inherited and acquired noncirrhotic portal hypertension, expand the phenotypic spectrum of DGUOK deficiency, and provide a new genetic test for a specific cause of idiopathic noncirrhotic portal hypertension. (Hepatology 2016;63:1977-1986).

}, keywords = {Adolescent, Amino Acid Sequence, Animals, Cattle, Child, Child, Preschool, DNA Mutational Analysis, Dogs, Female, Genes, Recessive, Homozygote, Humans, Hypertension, Portal, Infant, Liver Failure, Male, Molecular Sequence Data, Pedigree, Phosphotransferases (Alcohol Group Acceptor), Principal Component Analysis, Rats, Young Adult}, issn = {1527-3350}, doi = {10.1002/hep.28499}, author = {Vilarinho, S{\'\i}lvia and Sari, Sinan and Yilmaz, G{\"u}ldal and Stiegler, Amy L and Boggon, Titus J and Jain, Dhanpat and Akyol, G{\"u}len and Dalgi{\c c}, Buket and G{\"u}nel, Murat and Lifton, Richard P} } @article {224, title = {Mutation of NLRC4 causes a syndrome of enterocolitis and autoinflammation.}, journal = {Nat Genet}, volume = {46}, year = {2014}, month = {2014 Oct}, pages = {1135-1139}, abstract = {

Upon detection of pathogen-associated molecular patterns, innate immune receptors initiate inflammatory responses. These receptors include cytoplasmic NOD-like receptors (NLRs) whose stimulation recruits and proteolytically activates caspase-1 within the inflammasome, a multiprotein complex. Caspase-1 mediates the production of interleukin-1 family cytokines (IL1FCs), leading to fever and inflammatory cell death (pyroptosis). Mutations that constitutively activate these pathways underlie several autoinflammatory diseases with diverse clinical features. We describe a family with a previously unreported syndrome featuring neonatal-onset enterocolitis, periodic fever, and fatal or near-fatal episodes of autoinflammation. We show that the disease is caused by a de novo gain-of-function mutation in NLRC4 encoding a p.Val341Ala substitution in the HD1 domain of the protein that cosegregates with disease. Mutant NLRC4 causes constitutive IL1FC production and macrophage cell death. Infected macrophages from affected individuals are polarized toward pyroptosis and exhibit abnormal staining for inflammasome components. These findings identify and describe the cause of a life-threatening but treatable autoinflammatory disease that underscores the divergent roles of the NLRC4 inflammasome.

}, keywords = {Calcium-Binding Proteins, CARD Signaling Adaptor Proteins, Enterocolitis, Exome, Family Health, Fatal Outcome, Female, Humans, Inflammation, Male, Mutation, Missense, Pedigree, Sequence Analysis, DNA, Syndrome}, issn = {1546-1718}, doi = {10.1038/ng.3066}, author = {Romberg, Neil and Al Moussawi, Khatoun and Nelson-Williams, Carol and Stiegler, Amy L and Loring, Erin and Choi, Murim and Overton, John and Meffre, Eric and Khokha, Mustafa K and Huttner, Anita J and West, Brian and Podoltsev, Nikolai A and Boggon, Titus J and Kazmierczak, Barbara I and Lifton, Richard P} }