Dynamics of Transcription Factors in Three Early Phases of Osteogenic, Adipogenic, and Chondrogenic Differentiation Determining the Fate of Bone Marrow Mesenchymal Stem Cells in Rats

The imbalance of osteogenic, adipogenic, and chondrogenic differentiation in bone marrow mesenchymal stem cells (BMSCs) occurred in multiple age-related degenerative diseases such as osteoporosis and osteoarthritis. In order to improve our understanding and control of multi-directional differentiation of BMSCs in rats, using high-throughput sequencing, we identified key gene regulatory events in the early stages of lineage commitment. Data analysis revealed two transcription factors (TFs, Tsc22d3, and Epas1) with elevated expression throughout the initiation of differentiation (3 h), lineage acquisition (12 h), and early lineage progression (72 h) of three-directional differentiation. For osteogenic differentiation, 792, 1,042, and 638 differentially expressed genes including 48, 59, and 34 TFs were identified at three time points, respectively. Moreover, the functional analysis demonstrated that 4, 12, and 5 TFs were only differentially expressed during osteogenic differentiation at 3, 12, and 72 h, respectively, and not during other two-directional differentiation. Hopx showed enhanced expression throughout three early phases during the osteogenic differentiation but no significant change in other two-directional differentiation. A similar pattern of Gbx2 expression occurred in chondrogenic differentiation. Thus, Hopx and other early responder TFs may control the osteogenic cell fate of BMSCs and participate in the development of osteoporosis. Gbx2 and other early responder TFs should be considered in mechanistic models that clarify cartilage-anabolic changes in the clinical progression of osteoarthritis.

Dynamics of the HD regulatory subdomain of PARP-1; substrate access and allostery in PARP activation and inhibition

ABSTRACTPARP-1 is a key early responder to DNA damage in eukaryotic cells. An allosteric mechanism links initial sensing of DNA single-strand breaks by PARP-1’s F1 and F2 domains via a process of further domain assembly to activation of the catalytic domain (CAT); synthesis and attachment of poly(ADP-ribose) (PAR) chains to protein sidechains then signals for assembly of DNA repair components. A key component in transmission of the allosteric signal is the HD subdomain of CAT, which alone bridges between the assembled DNA-binding domains and the active site in the ART subdomain of CAT. Here we present a study of isolated CAT domain from human PARP-1, using NMR-based dynamics experiments to analyse WT apo-protein as well as a set of inhibitor complexes (with veliparib, olaparib, talazoparib and EB-47) and point mutants (L713F, L765A and L765F), together with new crystal structures of the free CAT domain and inhibitor complexes. Variations in both dynamics and structures amongst these species point to a model for full-length PARP-1 activation where first DNA binding and then substrate interaction successively destabilise the folded structure of the HD subdomain to the point where its steric blockade of the active site is released and PAR synthesis can proceed.

Both DNA binding domains of p53 are required for its ultra-rapid recruitment to sites of UV damage

Abstractp53 concentrates at DNA damage sites within two seconds upon UV laser micro-irradiation. Structural analysis shows that this very rapid response requires both the DNA binding and C-terminal domains of p53. This early recruitment response is also PARP-dependent. As mutations within the DNA binding domain of p53, that are commonly associated with cancer also inhibit this rapid binding, we suggest that this is an important initial step for p53 function as a tumor suppressor.One Sentence Summaryp53 is an early responder to DNA damage

Neonates Effects and Tolerability of Treprostinil in Hypertension with Persistent Pulmonary

Objective The aim of this study was to establish the effects of treprostinil in congenital diaphragmatic hernia (CDH) patients with persistent pulmonary hypertension (PHT) after 1 week of treatment. Drug effects were assessed by oxygenation index (OI), clinical end points, serial biochemical markers, and pre- and posttreatment echocardiogram. Treatment complications were also described. Study Design This is a quasi-experimental study of neonates with PHT admitted to the NICU within 48 hours showing persistent clinical instability, receiving mechanical ventilation with FiO2 > 60%, milrinone therapy, and inhaled nitric oxide. Clinical data were compared before and after treprostinil treatment. Results Seventeen neonates met the inclusion criteria. Median age was 17 days. Before treatment, median OI was 20 (IQR: 12–27). Suprasystemic PHT was estimated by echocardiogram in 8/17 patients; the rest were systemic. After 1 week of treatment, 15/17 patients were alive and median OI was 8 (IQR: 5–12, p = 0.0089). There were no statistically significant changes in laboratory data. Echocardiogram still showed suprasystemic PHT in 20% of patients. Adverse effects included hypotension, hematoma at the infusion site, and surgical persistent ductus arteriosus (PDA) closure in 4/17 patients. Fourteen patients were discharged. The median treatment time was 61 days. Conclusion Treprostinil was well tolerated with satisfactory clinical response. Further studies are required to identify early responder subgroups.

Role of neutrophils in equine asthma

Neutrophilic bronchiolitis is the primary lesion in asthma-affected horses. Neutrophils are key actors in host defense, migrating toward sites of inflammation and infection, where they act as early responder cells toward external insults. However, neutrophils can also mediate tissue damage in various non-infectious inflammatory processes. Within the airways, these cells likely contribute to bronchoconstriction, mucus hypersecretion, and pulmonary remodeling by releasing pro-inflammatory mediators, including the cytokines interleukin (IL)-8 and IL-17, neutrophil elastase, reactive oxygen species (ROS), and neutrophil extracellular traps (NETs). The mechanisms that regulate neutrophil functions in the tissues are complex and incompletely understood. Therefore, the inflammatory activity of neutrophils must be regulated with exquisite precision and timing, a task achieved through a complex network of mechanisms that regulates neutrophil survival. The discovery and development of compounds that can help regulate ROS, NET formation, cytokine release, and clearance would be highly beneficial in the design of therapies for this disease in horses. In this review, neutrophil functions during inflammation will be discussed followed by a discussion of their contribution to airway tissue injury in equine asthma.

Absolute Reticulocyte Count and Reticulocyte Hemoglobin Content as Predictors of Early Response to Exclusive Oral Iron in Children with Iron Deficiency Anemia

We report data regarding kinetic of response to oral iron in 34 iron deficiency anemia children. Twenty-four/34 patients (70.5%) reached reference value of hemoglobin (Hb) concentration for age and sex at day + 30 from the beginning of treatment (complete early responders (CERs)), and 4/34 (12%) reached an Hb concentration at least 50% higher than the original (partial early responders (PERs)). CHr at T1 (within 7 days from the beginning of treatment) was significantly different in the different groups (22.95 in CERs versus 18.41 in other patients;p=0.001; 22.42 in early responders versus 18.07 in NERs;p=0.001). Relative increase of CHr from T0 to T1 resulted significantly higher in CERs than in other patients (0.21 versus 0.11,p=0.042) and in early responders than in NERs (0.22 versus 0.004,p=0.006). Multivariate logistic models revealed a higher probability of being a complete early responder due to relative increase of ARC from T0 to T1 [OR (95% CI) = 44.95 (1.54–1311.98)] and to CHr at T1 [OR (95% CI) =3.18 (1.24–8.17)]. Our preliminary data confirm CHr as early and accurate predictor of hematological response to oral iron.

Treatment-Related Mortality (TRM) in Children with Down Syndrome (DS) and B-Lymphoblastic Leukemia (B-ALL): An Interim Report from the Children's Oncology Group Trials AALL0932 and AALL1131

Background: Children with DS and B-ALL have historically experienced excessive TRM, primarily from infection. Here we provide an interim report on TRM in children with DS and newly diagnosed B-ALL enrolled on Children's Oncology Group (COG) trials for NCI standard risk (SR) (AALL0932) and high risk (HR) B-ALL (AALL1131). Methods: As of 06/30/2015, 203 SR DS-ALL patients have completed Induction on AALL0932 with 146 receiving post-Induction treatment on AALL0932. Eighty-eight HR DS patients have completed Induction on AALL1131, with 80 receiving post-Induction treatment on AALL1131. An additional 26 SR DS patients with poor early response received post-Induction therapy on AALL1131. Adverse events were graded according to NCI CTCAE v4.0, with enhanced data collection for targeted toxicities including infectious toxicities, and enhanced supportive care recommendations. Results: Patient characteristics are summarized in Table 1. TRM on AALL0932 occurred during Induction in 2/203 (1.0%) and post-Induction in 3/146 (2.1%), compared to 17/5528 (0.3%) and 12/3119 (0.4%) in non-DS SR patients (Fisher exact p=0.14 for Induction and p=0.03 for post-Induction). TRM on AALL1131 occurred during Induction in 4/88 (4.5%) and post-Induction in 5/106 (4.7%), compared to 34/2116 (1.6%) and 13/1258 (1.0%) in non-DS AALL1131 patients (p=0.06 for Induction and p=0.01 for post-Induction). Timing, cause, and other circumstances surrounding TRM are provided in Table 2. Gram-negative organisms accounted for the majority of fatal bacterial infections in patients with HR DS-ALL. Conclusion: TRM continues to be higher on current COG trials for patients with DS-ALL compared to non-DS patients. Most of the toxic deaths occur during intensive treatment phases due to infection in the context of profound neutropenia. Patients with HR B-ALL have a higher incidence of toxic death, notably in patients over 15 years of age. Based on our findings, hospitalization and antimicrobial prophylaxis during intensive treatment phases should be considered in children with DS-ALL due to their increased risk of infection-related mortality. Table 1. Patient Characteristics AALL1131 AALL0932 DS-ALL Non-DS ALL DS-ALL Non-DS ALL N 117 2689 207 5619 Median Age at Diagnosis (Years) 10.5 10.3 4.8 4.5 Gender Male 62 1511 117 2981 Female 55 1178 90 2637 Table 2. Treatment-Related Mortality Case Characteristics Case Age Gender Treatment Phase Site of Infection Organism AALL1131 (High Risk) 1 15 F Induction D#29 (RER) Pneumonia, ARDS HMPV (pre-treatment) 2 21 F Induction D#29 (SER) Sepsis 3 17 F Induction D#22 (SER) Sepsis, typhlitis Escherichia coli 4 12 M Induction D#16 (RER) Sepsis, pneumonia (+baseline CHD, AV canal s/p repair 2003) Influenza B 5 19 M Consolidation D#18 Sepsis Citrobacter 6 2 F Delayed Intensification D#101 ARDS/capillary leak (+baseline CHD) Rhinovirus 7 15 F Delayed Intensification D#45 Sepsis, pneumonia Klebsiella, enterovirus, rhinovirus 8 27 M Delayed Intensification D#52 Sepsis Gram negative bacillus 9 14 M Delayed Intensification D#22 Sepsis AALL0932 (Standard Risk) 1 7.3 M Induction Febrile neutropenia, hypotension, cardiorespiratory failure None reported 2 3.0 F Induction Febrile neutropenia, sepsis, liver failure Viridans group Strepococcus coagulase negative staphylococcus HSV, EBV and HHV 3 3.4 M Consolidation Meningitis, brainstem infarction None reported 4 9.7 F Interim Maintenance I Sepsis, Stevens Johnson syndrome/TEN None reported 5 7.2 M Interim Maintenance II Death NOS None reported RER, rapid early responder; SER, slow early responder; CHD, congenital heart disease; AV, atrioventricular; ARDS, acute respiratory distress syndrome; HMPV, human metapneumovirus; TEN, toxic epidermal necrolysis; HSV, herpes simplex virus; EBV, Epstein-Barr virus; HHV, human herpesvirus. Disclosures Hunger: Sigma Tau: Consultancy; Jazz Pharmaceuticals: Consultancy; Merck: Equity Ownership; Spectrum Pharmaceuticals: Consultancy.