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Objective Most patients with rheumatoid arthritis (RA) undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA) have active RA and report postoperative flares; whether RA disease activity or flares increase the risk of worse pain and function scores 1 year later is unknown. Methods Patients with RA were enrolled before THA/TKA. Patient-reported outcomes, including the Hip disability and Osteoarthritis Outcome Score (HOOS)/Knee Injury and Osteoarthritis Outcome Score (KOOS) and physician assessments of disease characteristics and activity (Disease Activity Score in 28 joints [DAS28] and Clinical Disease Activity Index), were collected before surgery. Patient-reported outcomes were repeated at 1 year. Postoperative flares were identified using the RA Flare Questionnaire weekly for 6 weeks and were defined by concordance between patient report plus physician assessment. We compared baseline characteristics and HOOS/KOOS scores using 2-sample t-test/Wilcoxon's rank sum test as well as chi-square/Fisher's exact tests. We used multivariate linear and logistic regression to determine the association of baseline characteristics, disease activity, and flares with 1-year outcomes. Results One-year HOOS/KOOS scores were available for 122 patients (56 with THA and 66 with TKA). Although HOOS/KOOS pain was worse for patients who experienced a flare within 6 weeks of surgery, absolute improvement was not different. In multivariable models, baseline DAS28 predicted 1-year HOOS/KOOS pain and function; each 1-unit increase in DAS28 worsened 1-year pain by 2.41 (SE 1.05; P = 0.02) and 1-year function by 4.96 (SE 1.17; P = 0.0001). Postoperative flares were not independent risk factors for pain or function scores. Conclusion Higher disease activity increased the risk of worse pain and function 1 year after arthroplasty, but postoperative flares did not.

Based on national registry reports, after age 42, the number of IVF cycles utilizing autologous oocytes is very small; after age 43, autologous oocyte use in US IVF cycles is almost non-existent. We here argue that the in vitro fertilization (IVF) field has created a self-fulfilling prophecy by basically abandoning the utilization of autologous oocytes after ages 42-43 years. This not only resulted in almost no IVF cycles with autologous oocytes being performed but also in abandonment of research that could lead to improvements in IVF outcomes in older women when using autologous oocytes. As a consequence, IVF has largely stagnated in this area. We further argue that third-party oocyte donation in clinical IVF should be considered a treatment failure, as it requires patients to choose a second rather than a first-choice treatment. Such a redesignation of third-party egg donation would not only be appropriate but could lead to necessary changes in physician attitudes, considering that women almost exclusively prefer to conceive with their autologous oocytes.

Mammalian cells contain two isoforms of RNA polymerase III (Pol III) that differ in only a single subunit, with POLR3G in one form (Pol III alpha) and the related POLR3GL in the other form (Pol III beta). Previous research indicates that POLR3G and POLR3GL are differentially expressed, with POLR3G expression being highly enriched in embryonic stem cells (ESCs) and tumor cells relative to the ubiquitously expressed POLR3GL. To date, the functional differences between these two subunits remain largely unexplored, especially in vivo. Here, we show that POLR3G and POLR3GL containing Pol III complexes bind the same target genes and assume the same functions both in vitro and in vivo and, to a significant degree, can compensate for each other in vivo. Notably, an observed defect in the differentiation ability of POLR3G knockout ESCs can be rescued by exogenous expression of POLR3GL. Moreover, whereas POLR3G knockout mice die at a very early embryonic stage, POLR3GL knockout mice complete embryonic development without noticeable defects but die at about 3 wk after birth with signs of both general growth defects and potential cerebellum-related neuronal defects. The different phenotypes of the knockout mice likely reflect differential expression levels of POLR3G and POLR3GL across developmental stages and between tissues and insufficient amounts of total Pol III in vivo.

Background Skin biopsies promote our understanding of atopic dermatitis/AD pathomechanisms in infants/toddlers with early-onset AD, but are not feasible in pediatric populations. Tape strips are an emerging, minimally invasive alternative, but global transcriptomic profiling in early pediatric AD is lacking. We aimed to provide global lesional and nonlesional skin profiles of infants/toddlers with recent-onset, moderate-to-severe AD using tape strips. Methods Sixteen tape strips were collected for RNA-seq profiling from 19 infants/toddlers (<5 years old; lesional and nonlesional) with early-onset moderate-to-severe AD (<= 6 months) and 17 healthy controls. Results We identified 1829 differentially expressed genes/DEGs in lesional AD and 662 DEGs in nonlesional AD, vs healthy skin (fold-change >= 2, FDR <0.05), with 100% sample recovery. Both lesional and nonlesional skin showed significant dysregulations of Th2 (CCL17 and IL4R) and Th22/Th17 (IL36G, CCL20, and S100As)-related genes, largely lacking significant Th1-skewing. Significant down-regulation of terminal differentiation (FLG and FLG2), lipid synthesis/metabolism (ELOVL3 and FA2H), and tight junction (CLDN8) genes were primarily seen in lesional AD. Significant negative correlations were identified between Th2 measures and epidermal barrier gene-subsets and individual genes (FLG with IL-4R and CCL17;r < -0.4,P < .05). Significant correlations were also identified between clinical measures (body surface area/BSA, pruritus ADQ, and transepidermal water loss/TEWL) with immune and barrier mRNAs in lesional and/or nonlesional AD (FLG/FLG2 with TEWL;r < -0.4,P < .05). Conclusion RNA-seq profiling using tape strips in early-onset pediatric AD captures immune and barrier alterations in both lesional and nonlesional skin. Tape strips provide insight into disease pathomechanisms and cutaneous disease activity.

Growth factor deficiency in adulthood constitutes a distinct clinical syndrome with significant morbidities including abnormal body composition, reduced energy, affective disturbances, dyslipidemia, and increased cardiovascular risk. Protein replacement therapies using recombinant proteins or enzymes represent the only approved treatment. Combinatorial antibodies have shown great promise as a new class of therapeutic molecules because they act as "mechanism-based antibodies" with both agonist and antagonist activities. Using leptin, a key hormone in energy metabolism, as an example, a function-guided approach is developed to select combinatorial antibodies with high potency and full agonist activity that substitute natural growth factors in vivo. The identified antibody shows identical biochemical properties and cellular profiles as leptin, and rescues leptin-deficiency in ob/ob mice. Remarkably, the antibody activates leptin receptors that are otherwise nonfunctional because of mutations (L372A and A409E). Combinatorial antibodies have significant advantages over recombinant proteins for chronical usage in terms of immunological tolerance and biological stability.

E2A, a basic helix-loop-helix transcription factor, plays a crucial role in determining tissue - specific cell fate, including differentiation of B-cell lineages. In 5% of childhood acute lymphoblastic leukemia (ALL), the t(1,19) chromosomal translocation specifically targets the E2A gene and produces an oncogenic E2A-PBX1 fusion protein. Although previous studies have shown the oncogenic functions of E2A-PBX1 in cell and animal models, the E2A-PBX1-enforced cistrome, the E2A-PBX1 interactome, and related mechanisms un-derlying leukemogenesis remain unclear. Here, by unbiased genomic profiling approaches, we identify the direct target sites of E2A-PBX1 in t(1,19)positive pre-B ALL cells and show that, compared with normal E2A, E2A-PBX1 preferentially binds to a subset of gene loci cobound by RUNX1 and gene-activating machineries (p300, MED1, and H3K27 acetyla- tion). Using biochemical analyses, we further document a direct interaction of E2A-PBX1, through a region spanning the PBX1 homeodomain, with RUNX1. Our results also show that E2A-PBX1 binding to gene enhancers is dependent on the RUNX1 interaction but not the DNA-binding activity harbored within the PBX1 homeodomain of E2A-PBX1. Tran-scriptome analyses and cell transformation assays further establish a significant RUNX1 requirement for E2A-PBX1-mediated target gene activation and leukemogenesis. Notably, the RUNX1 locus itself is also directly activated by E2A-PBX1, indicating a multilayered interplay between E2A-PBX1 and RUNX1. Collectively, our study provides the first unbiased profiling of the E2A-PBX1 cistrome in pre-B ALL cells and reveals a previously unappreciated pathway in which E2A-PBX1 acts in concert with RUNX1 to enforce transcriptome alterations for the development of pre-B ALL.

During development, neurons adjust their energy balance to meet the high demands of robust axonal growth and branching. The mechanisms that regulate this tuning are largely unknown. Here, we show that sensory neurons lacking liver kinase B1 (Lkb1), a master regulator of energy homeostasis, exhibit impaired axonal growth and branching. Biochemical analysis of these neurons revealed reduction in axonal ATP levels, whereas transcriptome analysis uncovered down-regulation of Efhdl (EF-hand domain family member D1), a mitochondrial Ca2+-binding protein. Genetic ablation of Efhd1 in mice resulted in reduced axonal morphogenesis as well as enhanced neuronal death. Strikingly, this ablation causes mitochondrial dysfunction and a decrease in axonal ATP levels. Moreover, Efhd1 KO sensory neurons display shortened mitochondria at the axonal growth cones, activation of the AMP-activated protein kinase (AMPK)-Ulk (Unc-51-like autophagy-activating kinase 1) pathway and an increase in autophagic flux. Overall, this work uncovers a new mitochondrial regulator that is required for axonal morphogenesis.

Cell death is an important facet of animal development. In some developing tissues, death is the ultimate fate of over 80% of generated cells. Although recent studies have delineated a bewildering number of cell death mechanisms, most have only been observed in pathological contexts, and only a small number drive normal development. This Primer outlines the important roles, different types and molecular players regulating developmental cell death, and discusses recent findings with which the field currently grapples. We also clarify terminology, to distinguish between developmental cell death mechanisms, for which there is evidence for evolutionary selection, and cell death that follows genetic, chemical or physical injury. Finally, we suggest how advances in understanding developmental cell death may provide insights into the molecular basis of developmental abnormalities and pathological cell death in disease.

Centromeres are the complex structures responsible for the proper segregation of chromosomes during cell division. Structural or functional alterations of the centromere cause aneuploidies and other chromosomal aberrations that can induce cell death with consequences on health and survival of the organism as a whole. Because of their essential function in the cell, centromeres have evolved high flexibility and mechanisms of tolerance to preserve their function following stress, whether it is originating from within or outside the cell. Here, we review the main epigenetic mechanisms of centromeres' adaptability to preserve their functional stability, with particular reference to neocentromeres and holocentromeres. The centromere position can shift in response to altered chromosome structures, but how and why neocentromeres appear in a given chromosome region are still open questions. Models of neocentromere formation developed during the last few years will be hereby discussed. Moreover, we will discuss the evolutionary significance of diffuse centromeres (holocentromeres) in organisms such as nematodes. Despite the differences in DNA sequences, protein composition and centromere size, all of these diverse centromere structures promote efficient chromosome segregation, balancing genome stability and adaptability, and ensuring faithful genome inheritance at each cellular generation.

Respiratory syncytial virus enters cells by binding to cell-surface IGFR1, which activates PKC zeta and induces trafficking of the NCL coreceptor to the RSV particles at the cell surface. Pneumonia resulting from infection is one of the leading causes of death worldwide. Pulmonary infection by the respiratory syncytial virus (RSV) is a large burden on human health, for which there are few therapeutic options(1). RSV targets ciliated epithelial cells in the airways, but how viruses such as RSV interact with receptors on these cells is not understood. Nucleolin is an entry coreceptor for RSV2 and also mediates the cellular entry of influenza, the parainfluenza virus, some enteroviruses and the bacterium that causes tularaemia(3,4). Here we show a mechanism of RSV entry into cells in which outside-in signalling, involving binding of the prefusion RSV-F glycoprotein with the insulin-like growth factor-1 receptor, triggers the activation of protein kinase C zeta (PKC zeta). This cellular signalling cascade recruits nucleolin from the nuclei of cells to the plasma membrane, where it also binds to RSV-F on virions. We find that inhibiting PKC zeta activation prevents the trafficking of nucleolin to RSV particles on airway organoid cultures, and reduces viral replication and pathology in RSV-infected mice. These findings reveal a mechanism of virus entry in which receptor engagement and signal transduction bring the coreceptor to viral particles at the cell surface, and could form the basis of new therapeutics to treat RSV infection.