Candidate Tear-Based Uveitis Biomarkers in Children with JIA Based on Arthritis Activity and Topical Corticosteroid Use.

Background: Uveitis is an inflammatory ocular disease secondary to disruption of the retinal pigmented epithelium (RPE) and blood retinal barrier (BRB). Known clinical factors do not accurately predict uveitis risk in Juvenile Idiopathic Arthritis (JIA). Tear fluid is easily obtained for biomarker study.

Evolutionary origins and innovations sculpting the mammalian PRPS enzyme complex.

The phosphoribosyl pyrophosphate synthetase (PRPS) enzyme conducts a chokepoint reaction connecting central carbon metabolism and nucleotide production pathways, making it essential for life. Here, we show that the presence of multiple PRPS-encoding genes is a hallmark trait of eukaryotes, and we trace the evolutionary origins and define the individual functions of each of the five mammalian PRPS homologs - three isozymes (one testis-restricted) and two non-enzymatic associated proteins (APs) - which we demonstrate operate together as a large molecular weight complex capable of attaining a heterogeneous array of functional multimeric configurations. Employing a repertoire of isogenic fibroblast clones in all viable individual or combinatorial assembly states, we define preferential interactions between subunits, and we show that cells lacking PRPS2, PRPSAP1, and PRPSAP2 render PRPS1 into aberrant homo-oligomeric assemblies with diminished metabolic flux and impaired proliferative capacity.

Dysregulated innate immune signaling cooperates with RUNX1 mutations to transform an MDS-like disease to AML.

Dysregulated innate immune signaling is linked to preleukemic conditions and myeloid malignancies. However, it is unknown whether sustained innate immune signaling contributes to malignant transformation. Here we show that cell-intrinsic innate immune signaling driven by miR-146a deletion (miR-146a), a commonly deleted gene in myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML), cooperates with mutant RUNX1 (RUNX1) to initially induce marrow failure and features of MDS.

Prenatal SARS-CoV-2 infection alters postpartum human milk-derived extracellular vesicles.

Human milk-derived extracellular vesicles (HMEVs) are crucial functional components in breast milk, contributing to infant health and development. Maternal conditions could affect HMEV cargos; however, the impact of SARS-CoV-2 infection on HMEVs remains unknown. This study evaluated the influence of SARS-CoV-2 infection during pregnancy on postpartum HMEV molecules.

Repression of TRIM13 by chromatin assembly factor CHAF1B is critical for AML development.

Acute myeloid leukemia (AML) is an aggressive blood cancer that stems from the rapid expansion of immature leukemic blasts in the bone marrow. Mutations in epigenetic factors represent the largest category of genetic drivers of AML. The chromatin assembly factor CHAF1B is a master epigenetic regulator of transcription associated with self-renewal and the undifferentiated state of AML blasts.

Paralog-specific signaling by IRAK1/4 maintains MyD88-independent functions in MDS/AML.

Dysregulation of innate immune signaling is a hallmark of hematologic malignancies. Recent therapeutic efforts to subvert aberrant innate immune signaling in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) have focused on the kinase IRAK4. IRAK4 inhibitors have achieved promising, though moderate, responses in preclinical studies and clinical trials for MDS and AML.

Insights into pulmonary phosphate homeostasis and osteoclastogenesis emerge from the study of pulmonary alveolar microlithiasis.

Pulmonary alveolar microlithiasis is an autosomal recessive lung disease caused by a deficiency in the pulmonary epithelial Npt2b sodium-phosphate co-transporter that results in accumulation of phosphate and formation of hydroxyapatite microliths in the alveolar space. The single cell transcriptomic analysis of a pulmonary alveolar microlithiasis lung explant showing a robust osteoclast gene signature in alveolar monocytes and the finding that calcium phosphate microliths contain a rich protein and lipid matrix that includes bone resorbing osteoclast enzymes and other proteins suggested a role for osteoclast-like cells in the host response to microliths. While investigating the mechanisms of microlith clearance, we found that Npt2b modulates pulmonary phosphate homeostasis through effects on alternative phosphate transporter activity and alveolar osteoprotegerin, and that microliths induce osteoclast formation and activation in a receptor activator of nuclear factor-κB ligand and dietary phosphate dependent manner.

Label-Free Quantification (LFQ) of Fecal Proteins for Potential Pregnancy Detection in Polar Bears.

Reliable pregnancy diagnostics would be beneficial for monitoring polar bear () populations both in situ and ex situ, but currently there is no method of non-invasive pregnancy detection in this species. Recent reports in several carnivore species described the identification of fecal proteins that may serve as pregnancy biomarkers; however, repeatability has been limited. The objective of the current analysis was to utilize an unbiased, antibody-free, label-free method for the identification and quantification of fecal proteins to determine if differences associated with pregnancy are detectable in polar bears.

Tyrosine nitration of a humanized anti-cocaine mAb differentially affects ligand binding of cocaine and its metabolites.

Tetranitromethane was used to selectively modify tyrosine residues of a humanized anti-cocaine mAb (h2E2), under development for the treatment of cocaine use disorders. The effect of mild tyrosine nitration on the affinity of cocaine and two high affinity cocaine metabolites, cocaethylene and benzoylecgonine, was assessed using differential scanning fluorimetry to measure ligand affinities via ligand-induced thermal stabilization of the mAb antigen binding region. Nitrated tyrosine residues were identified by mass spectral analysis of thermolysin peptides.

Blocking UBE2N abrogates oncogenic immune signaling in acute myeloid leukemia.

Dysregulation of innate immune signaling pathways is implicated in various hematologic malignancies. However, these pathways have not been systematically examined in acute myeloid leukemia (AML). We report that AML hematopoietic stem and progenitor cells (HSPCs) exhibit a high frequency of dysregulated innate immune-related and inflammatory pathways, referred to as oncogenic immune signaling states.

Oxidation of specific tryptophan residues inhibits high-affinity binding of cocaine and its metabolites to a humanized anticocaine mAb.

Cocaine addiction remains a serious problem lacking an effective pharmacological treatment. Thus, we have developed a high-affinity anti-cocaine monoclonal antibody (mAb), h2E2, for the treatment of cocaine use disorders. We show that selective tryptophan (Trp) oxidation by 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) resulted in a loss of high-affinity binding of cocaine to this mAb.

Cutting Edge: l-Arginine Transfer from Antigen-Presenting Cells Sustains CD4 T Cell Viability and Proliferation.

Metabolomics analyses suggest changes in amino acid abundance, particularly l-arginine (L-ARG), occur in patients with tuberculosis. Immune cells require L-ARG to fuel effector functions following infection. We have previously described an L-ARG synthesis pathway in immune cells; however, its role in APCs has yet to be uncovered.

TRAF6 functions as a tumor suppressor in myeloid malignancies by directly targeting MYC oncogenic activity.

Clonal hematopoiesis (CH) is an aging-associated condition characterized by the clonal outgrowth of pre-leukemic cells that acquire specific mutations. Although individuals with CH are healthy, they are at an increased risk of developing myeloid malignancies, suggesting that additional alterations are needed for the transition from a pre-leukemia stage to frank leukemia. To identify signaling states that cooperate with pre-leukemic cells, we used an in vivo RNAi screening approach.

FBXO11 is a candidate tumor suppressor in the leukemic transformation of myelodysplastic syndrome.

Myelodysplastic syndrome (MDS) is a heterogeneous myeloid malignancy characterized by blood cell morphological dysplasia, ineffective clonal hematopoiesis, and risk of transformation to secondary acute myeloid leukemia (sAML). A number of genetic abnormalities have been identified in MDS and sAML, but sensitive sequencing methods can detect these mutations in nearly all healthy individuals by 60 years of age. To discover novel cellular pathways that accelerate MDS and sAML, we performed a CRISPR/Cas9 screen in the human MDS-L cell line.

Publisher Correction: Recognition of RNA N-methyladenosine by IGF2BP proteins enhances mRNA stability and translation.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Biotherapy of Brain Tumors with Phosphatidylserine-Targeted Radioiodinated SapC-DOPS Nanovesicles.

Glioblastoma multiforme (GBM), a common type of brain cancer, has a very poor prognosis. In general, viable GBM cells exhibit elevated phosphatidylserine (PS) on their membrane surface compared to healthy cells. We have developed a drug, saposin C-dioleoylphosphatidylserine (SapC-DOPS), that selectively targets cancer cells by honing in on this surface PS.

Phosphoproteomic analysis identifies phospho-Threonine-17 site of phospholamban important in low molecular weight isoform of fibroblast growth factor 2-induced protection against post-ischemic cardiac dysfunction.

Rationale: Among its many biological roles, fibroblast growth factor 2 (FGF2) protects the heart from dysfunction and damage associated with an ischemic attack. Our laboratory demonstrated that its protection against myocardial dysfunction occurs by the low molecular weight (LMW) isoform of FGF2, while the high molecular weight (HMW) isoforms are associated with a worsening in post-ischemic recovery of cardiac function. LMW FGF2-mediated cardioprotection is facilitated by activation of multiple kinases, including PKCalpha, PKCepsilon, and ERK, and inhibition of p38 and JNK.

Mouse models of neutropenia reveal progenitor-stage-specific defects.

Advances in genetics and sequencing have identified a plethora of disease-associated and disease-causing genetic alterations. To determine causality between genetics and disease, accurate models for molecular dissection are required; however, the rapid expansion of transcriptional populations identified through single-cell analyses presents a major challenge for accurate comparisons between mutant and wild-type cells. Here we generate mouse models of human severe congenital neutropenia (SCN) using patient-derived mutations in the GFI1 transcription factor.

SWATH-Proteomics of Ibrutinib's Action in Myeloid Leukemia Initiating Mutated G-CSFR Signaling.

Purpose: To evaluate cellular protein changes in response to treatment with an approved drug, ibrutinib, in cells expressing normal or mutated granulocyte-colony stimulating factor receptor (G-CSFR). G-CSFR mutations are associated with some hematological malignancies. Previous studies show the efficacy of ibrutinib (a Bruton's tyrosine kinase inhibitor) in mutated G-CSFR leukemia models but do not address broader signaling mechanisms.

TIFAB Regulates USP15-Mediated p53 Signaling during Stressed and Malignant Hematopoiesis.

TRAF-interacting protein with a forkhead-associated domain B (TIFAB) is implicated in myeloid malignancies with deletion of chromosome 5q. Employing a combination of proteomic and genetic approaches, we find that TIFAB regulates ubiquitin-specific peptidase 15 (USP15) ubiquitin hydrolase activity. Expression of TIFAB in hematopoietic stem/progenitor cells (HSPCs) permits USP15 signaling to substrates, including MDM2 and KEAP1, and mitigates p53 expression.

Phospho serine and threonine analysis of normal and mutated granulocyte colony stimulating factor receptors.

Granulocyte colony stimulating factor receptor (G-CSFR) plays an important role in the production of neutrophil granulocytes. Mutated G-CSFRs have been directly associated with two distinct malignant phenotypes in patients, e.g.

Identification of Urinary CD44 and Prosaposin as Specific Biomarkers of Urinary Tract Infections in Children With Neurogenic Bladders.

Purpose: Distinguishing urinary tract infection (UTI) from urinary tract colonization (UTC) in children with neurogenic bladders who require clean intermittent catheterization (CIC) is challenging. Our objective was to identify urinary proteins to distinguish UTI from UTC in CIC-dependent children that have potential to serve as objective markers of UTI.

Experimental Design: A total of 10 CIC-dependent children were included in the mass spectrometry analysis (UTI = 5, UTC = 5).

Utilization of Reactive Oxygen Species Targeted Therapy to Prolong the Efficacy of BRAF Inhibitors in Melanoma.

BRAF mutations occur in about 50% of melanoma patients. FDA approved BRAF and MEK inhibitors have improved the prognosis of patients with BRAF mutations. However, all responders develop resistance typically within one year of treatment.

Domain unfolding of monoclonal antibody fragments revealed by non-reducing SDS-PAGE.

Monoclonal antibodies and derived fragments are used extensively both experimentally and therapeutically. Thorough characterization of such antibodies is necessary and includes assessment of their thermal and storage stabilities. Thus, assessment of the underlying conformational stabilities of the antibodies is also important.