B Lymphocyte Specification Is Preceded by Extensive Epigenetic Priming in Multipotent Progenitors.

B lymphocyte development is dependent on the interplay between the chromatin landscape and lineage-specific transcription factors. It has been suggested that B lineage commitment is associated with major changes in the nuclear chromatin environment, proposing a critical role for lineage-specific transcription factors in the formation of the epigenetic landscape. In this report, we have used chromosome conformation capture in combination with assay for transposase-accessible chromatin sequencing analysis to enable highly efficient annotation of both proximal and distal transcriptional control elements to genes activated in B lineage specification in mice. A large majority of these genes were annotated to at least one regulatory element with an accessible chromatin configuration in multipotent progenitors. Furthermore, the majority of binding sites for the key regulators of B lineage specification, EBF1 and PAX5, occurred in already accessible regions. EBF1 did, however, cause a dynamic change in assay for transposase-accessible chromatin accessibility and was critical for an increase in distal promoter-enhancer interactions. Our data unravel an extensive epigenetic priming at regulatory elements annotated to lineage-restricted genes and provide insight into the interplay between the epigenetic landscape and transcription factors in cell specification.

ARID1a Associates with Lymphoid-Restricted Transcription Factors and Has an Essential Role in T Cell Development.

Maturation of lymphoid cells is controlled by the action of stage and lineage-restricted transcription factors working in concert with the general transcription and chromatin remodeling machinery to regulate gene expression. To better understand this functional interplay, we used Biotin Identification in human embryonic kidney cells to identify proximity interaction partners for GATA3, TCF7 (TCF1), SPI1, HLF, IKZF1, PAX5, ID1, and ID2. The proximity interaction partners shared among the lineage-restricted transcription factors included ARID1a, a BRG1-associated factor complex component. CUT&RUN analysis revealed that ARID1a shared binding with TCF7 and GATA3 at a substantial number of putative regulatory elements in mouse T cell progenitors. In support of an important function for ARID1a in lymphocyte development, deletion of Arid1a in early lymphoid progenitors in mice resulted in a pronounced developmental arrest in early T cell development with a reduction of CD4+CD8+ cells and a 20-fold reduction in thymic cellularity. Exploring gene expression patterns in DN3 cells from Wt and Arid1a-deficient mice suggested that the developmental block resided in the DN3a to DN3b transition, indicating a deficiency in ß-selection. Our work highlights the critical importance of functional interactions between stage and lineage-restricted factors and the basic transcription machinery during lymphocyte differentiation.

PAX5 is part of a functional transcription factor network targeted in lymphoid leukemia.

One of the most frequently mutated proteins in human B-lineage leukemia is the transcription factor PAX5. These mutations often result in partial rather than complete loss of function of the transcription factor. While the functional dose of PAX5 has a clear connection to human malignancy, there is limited evidence for that heterozygote loss of PAX5 have a dramatic effect on the development and function of B-cell progenitors. One possible explanation comes from the finding that PAX5 mutated B-ALL often display complex karyotypes and additional mutations. Thus, PAX5 might be one component of a larger transcription factor network targeted in B-ALL. To investigate the functional network associated with PAX5 we used BioID technology to isolate proteins associated with this transcription factor in the living cell. This identified 239 proteins out of which several could be found mutated in human B-ALL. Most prominently we identified the commonly mutated IKZF1 and RUNX1, involved in the formation of ETV6-AML1 fusion protein, among the interaction partners. ChIP- as well as PLAC-seq analysis supported the idea that these factors share a multitude of target genes in human B-ALL cells. Gene expression analysis of mouse models and primary human leukemia suggested that reduced function of PAX5 increased the ability of an oncogenic form of IKZF1 or ETV6-AML to modulate gene expression. Our data reveals that PAX5 belong to a regulatory network frequently targeted by multiple mutations in B-ALL shedding light on the molecular interplay in leukemia cells.

Proteomic Analysis of Endothelial Cells Exposed to Ultrasmall Nanoparticles Reveals Disruption in Paracellular and Transcellular Transport.

The large interactive surfaces of nanoparticles (NPs) increase the opportunities to develop NPs for vascular targeting. Proteomic analysis of endothelial cells exposed to NPs reveals the cellular response and turns the focus into the impairment of the endothelial permeability. Here, quantitative proteomics and transcriptome sequencing are combined to evaluate the effects of exposure to sub-lethal concentrations of TiO2 -USNPs and TiO2 -NPs on human dermal microvascular endothelial cells. Endothelial cells react to preserve the semi-permeable properties that are essential for vascular tissue fluid homeostasis, vascular development, and angiogenesis. The main impact of the exposure was alteration of functional complexes involved in cell adhesion, vesicular transport, and cytoskeletal structure. Those are the core cellular structures that are linked to the permeability and the integrity of the endothelial tissue. Moreover, the extracellular proteins uptake along wih the NPs into the endothelial cells escape the lysosomal degradation pathway. These findings improve the understanding of the interaction of NPs with endothelial cell. The effects of the studied NPs modulating cell-cell adhesion and vesicular transport can help to evaluate the distribution of NPs via intravenous administration.

The sink-specific plastidic phosphate transporter PHT4;2 influences starch accumulation and leaf size in Arabidopsis.

Nonphotosynthetic plastids are important sites for the biosynthesis of starch, fatty acids, and amino acids. The uptake and subsequent use of cytosolic ATP to fuel these and other anabolic processes would lead to the accumulation of inorganic phosphate (Pi) if not balanced by a Pi export activity. However, the identity of the transporter(s) responsible for Pi export is unclear. The plastid-localized Pi transporter PHT4;2 of Arabidopsis (Arabidopsis thaliana) is expressed in multiple sink organs but is nearly restricted to roots during vegetative growth. We identified and used pht4;2 null mutants to confirm that PHT4;2 contributes to Pi transport in isolated root plastids. Starch accumulation was limited in pht4;2 roots, which is consistent with the inhibition of starch synthesis by excess Pi as a result of a defect in Pi export. Reduced starch accumulation in leaves and altered expression patterns for starch synthesis genes and other plastid transporter genes suggest metabolic adaptation to the defect in roots. Moreover, pht4;2 rosettes, but not roots, were significantly larger than those of the wild type, with 40% greater leaf area and twice the biomass when plants were grown with a short (8-h) photoperiod. Increased cell proliferation accounted for the larger leaf size and biomass, as no changes were detected in mature cell size, specific leaf area, or relative photosynthetic electron transport activity. These data suggest novel signaling between roots and leaves that contributes to the regulation of leaf size.

Distribution Pattern and its Correlation for Oral Cancer Rate and Human Development Rank for Countries: An Ecological Approach.

INTRODUCTION: There is a general interpretation that the distribution and pattern of various cancers exhibit geographical variations between developed and developing countries. However, as far as oral cancer is concerned, these differential patterns of distribution are not much documented. AIM AND OBJECTIVE: This review is aimed to bring in the existence of geographical disparities and its pattern for oral cancer incidence and mortality. The objectives of this review are: (1) To compare and comment on the trends in estimates for oral cancer incidence and mortality for the years 2002, 2008, and 2012. (2) To correlate oral cancer incidence and mortality values for 2012 with the human development index (HDI) scores for 2012 for each country. Design: Ecological approach and entire review was carried out using two secondary data sets, and they were (i) Age-standardized oral cancer incidence and mortality value for all countries published by the International Agency on Cancer Research for the years 2002, 2008, and 2012. (ii) HDI score for all countries for the year 2012 released by the United Nations Development Program. RESULTS: A diametric pattern of distribution was observed across the two strata of countries. When developed countries have higher rates for incidence, low developed countries have higher rates for mortality.

Utilizing dental colleges for the eradication of oral cancer in India.

Dental education in India has grown in such a way that it ranks first in the world in having the highest number of dental schools. There are 240 dental schools all over the country. Paradoxically, even with this large number of dentists and dental institutions, India contributes to the highest number of incident cases of oral cancer. In India, oral cancer burden approximates to 20-30% of all cancers. The plausible reason for this high incidence of oral cancer could be expounded on the fact that there exists a high usage of tobacco within the country. The evidence for the high prevalence of using chewable tobacco products, especially in the youth, was recently reported in the Global Youth Tobacco Survey. This increasing usage of chewing tobacco and related products will further accrue to the mortality and morbidity figures in the near future. To effectuate a breakthrough in the existing situation, the work force of dental schools could be capitalized on. The aim of this article is to present the burden of oral cancer in the country and identify trends in the prevalence of tobacco usage, which if continues could alert an epidemic of oral cancer in the near future; and how dental schools in the country can be utilized for preventing this upcoming epidemic.

Zinc Finger Protein 521 Regulates Early Hematopoiesis through Cell-Extrinsic Mechanisms in the Bone Marrow Microenvironment.

Zinc finger protein 521 (ZFP521), a DNA-binding protein containing 30 Krüppel-like zinc fingers, has been implicated in the differentiation of multiple cell types, including hematopoietic stem and progenitor cells (HSPC) and B lymphocytes. Here, we report a novel role for ZFP521 in regulating the earliest stages of hematopoiesis and lymphoid cell development via a cell-extrinsic mechanism. Mice with inactivated Zfp521 genes (Zfp521-/-) possess reduced frequencies and numbers of hematopoietic stem and progenitor cells, common lymphoid progenitors, and B and T cell precursors. Notably, ZFP521 deficiency changes bone marrow microenvironment cytokine levels and gene expression within resident HSPC, consistent with a skewing of hematopoiesis away from lymphopoiesis. These results advance our understanding of ZFP521's role in normal hematopoiesis, justifying further research to assess its potential as a target for cancer therapies.

Shotgun proteomics to unravel marine mussel (Mytilus edulis) response to long-term exposure to low salinity and propranolol in a Baltic Sea microcosm.

Pharmaceuticals, among them the ß-adrenoceptor blocker propranolol, are an important group of environmental contaminants reported in European waters. Laboratory exposure to pharmaceuticals on marine species has been performed without considering the input of the ecosystem flow. To unravel the ecosystem response to long-term exposure to propranolol we have performed long-term exposure to propranolol and low salinity in microcosms. We applied shotgun proteomic analysis to gills of Mytilus edulis from those Baltic Sea microcosms and identified 2071 proteins with a proteogenomic strategy. The proteome profiling patterns from the 587 highly reproductive proteins among groups define salinity as a key factor in the mussel's response to propranolol. Exposure at low salinity drives molecular mechanisms of adaptation based on a decrease in the abundance of several cytoskeletal proteins, signalling and intracellular membrane trafficking pathway combined with a response towards the maintenance of transcription and translation. The exposure to propranolol combined with low salinity modulates the expression of structural proteins including cilia functions and decreases the expression of membrane protein transporters. This study reinforces the environment concerns of the impact of low salinity in combination with anthropogenic pollutants and anticipates critical physiological conditions for the survival of the blue mussel in the northern areas. BIOLOGICAL SIGNIFICANCE: Applying shotgun proteomic analysis to M. edulis gills samples from a long-term microcosm exposure to propranolol and following a proteogenomic identification strategy, we have identified 2071 proteins. The proteomic analysis unrevealed which molecular mechanisms drive the adaptation to low salinity stress and how salinity modulates the effects of exposure to propranolol. These results reinforce the idea of the impact of low salinity in combination with anthropogenic pollutants and anticipate critical physiological condition.

Repellency of α-pinene against the house fly, Musca domestica.

Musca domestica L. is a non-biting nuisance fly that is capable of transmitting a large variety of pathogens to humans and non-human animals. Natural compounds and their derivatives, which are often less toxic than entirely synthetic compounds, may be used as repellents against M. domestica as part of comprehensive pest control and disease mitigation programs. This work investigates the repellent properties of the natural compound α-pinene against M. domestica. Adult house flies of both sexes avoided the volatile plant-derived terpenes (1S)-(-)-α-pinene 1 and (1R)-(+)-α-pinene 2 in constant air flow laboratory conditions, with 1 exhibiting a stronger repellent effect. House flies also avoided tarsal contact with filter paper saturated with 1. Furthermore, both 1 and 2 are electrophysiologically active on in situ female house fly antennal preparations. These findings demonstrate that α-pinene exhibits natural baseline repellency against the house fly, elicits a specific physiological response in this fly, and that functional or structural modification of 1 in particular may yield novel fly repellents with desirable properties.

Pre-Anchoring of Pin1 to Unphosphorylated c-Myc in a Fuzzy Complex Regulates c-Myc Activity.

Hierarchic phosphorylation and concomitant Pin1-mediated proline isomerization of the oncoprotein c-Myc controls its cellular stability and activity. However, the molecular basis for Pin1 recognition and catalysis of c-Myc and other multisite, disordered substrates in cell regulation and disease is unclear. By nuclear magnetic resonance, surface plasmon resonance, and molecular modeling, we show that Pin1 subdomains jointly pre-anchor unphosphorylated c-Myc1-88 in the Pin1 interdomain cleft in a disordered, or "fuzzy", complex at the herein named Myc Box 0 (MB0) conserved region N-terminal to the highly conserved Myc Box I (MBI). Ser62 phosphorylation in MBI intensifies previously transient MBI-Pin1 interactions in c-Myc1-88 binding, and increasingly engages Pin1PPIase and its catalytic region with maintained MB0 interactions. In cellular assays, MB0 mutated c-Myc shows decreased Pin1 interaction, increased protein half-life, but lowered rates of Myc-driven transcription and cell proliferation. We propose that dynamic Pin1 recognition of MB0 contributes to the regulation of c-Myc activity in cells.

Comparative evaluation of subgingival plaque microflora in pregnant and non-pregnant women: A clinical and microbiologic study.

CONTEXT: Gingival changes in pregnancy have been attributed to changes in the subgingival biofilm related to hormonal variations. AIMS: To evaluate the subgingival plaque microflora in pregnant and nonpregnant women to determine if pregnancy induces any alterations in the subgingival plaque and to associate these changes with changes in periodontal status. SETTINGS AND DESIGN: Thirty pregnant and 10 nonpregnant women within the age group of 20-35 years having a probing pocket depth (PPD) of 3-4 mm were included in the study. The pregnant women were equally divided into 3 groups of 10, each belonging to I, II, and III trimester. MATERIALS AND METHODS: Plaque index, gingival index, PPD, and microbiologic evaluation for specific bacterial counts for Prevotella intermedia, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Parvimonas micra, and Fusobacterium nucleatum were carried out for all subjects. STATISTICAL ANALYSIS: Mann-Whitney U test. RESULTS: Increase in gingival inflammation was observed in II and III trimester as compared with I trimester and control. Plaque scores did not show any significant difference between pregnant and nonpregnant women. Specific bacterial examination revealed an increase in proportion of P. intermedia in pregnant women of both II and III trimester as compared with I trimester and nonpregnant women. CONCLUSIONS: A definite increase in proportions of P. intermedia occurs in subgingival plaque microflora in pregnancy that may be responsible for the exaggerated gingival response.

Root anatomy and root canal configuration of human permanent mandibular premolars: a systematic review.

Introduction. Mandibular premolars have been reported with complex anatomical aberrations, making them one of the most difficult teeth to manage endodontically. Methodology. An exhaustive search was undertaken to identify associated anatomic studies of mandibular premolars through MEDLINE/PubMed database using keywords, and a systematic review of the relevant articles was performed. Chi-square test with Yates correction was performed to assess the statistical significance of any anatomic variations between ethnicities and within populations of the same ethnicity. Documented case reports of variations in mandibular premolar anatomy were also identified and reviewed. Results. Thirty-six anatomic studies were analyzed which included 12,752 first premolars and nineteen studies assessing 6646 second premolars. A significant variation in the number of roots, root canals, and apical foramen was observed between Caucasian, Indian, Mongoloid, and Middle Eastern ethnicities.The most common anatomic variation was C-shaped canals in mandibular first premolars with highest incidence in Mongoloid populations (upto 24%) while dens invaginatus was the most common developmental anomaly. Conclusions. A systematic review of mandibular premolars based on ethnicity and geographic clusters offered enhanced analysis of the prevalence of number of roots and canals, their canal configuration, and other related anatomy.