Notch and Mef2 synergize to promote proliferation and metastasis through JNK signal activation in Drosophila.

Genetic analyses in Drosophila revealed a synergy between Notch and the pleiotropic transcription factor Mef2 (myocyte enhancer factor 2), which profoundly influences proliferation and metastasis. We show that these hyperproliferative and invasive Drosophila phenotypes are attributed to upregulation of eiger, a member of the tumour necrosis factor superfamily of ligands, and the consequent activation of Jun N-terminal kinase signalling, which in turn triggers the expression of the invasive marker MMP1. Expression studies in human breast tumour samples demonstrate correlation between Notch and Mef2 paralogues and support the notion that Notch-MEF2 synergy may be significant for modulating human mammary oncogenesis.

Stability and Volatility of Human Rest-Activity Rhythms: Insights from Very Long Actograms (VLAs).

Importance: Wrist-worn activity monitors provide biomarkers of health by non-obtrusively measuring the timing and amount of rest and physical activity (rest-activity rhythms, RARs). The morphology and robustness of RARs vary by age, gender, and sociodemographic factors, and are perturbed in various chronic illnesses. However, these are cross-sectionally derived associations from recordings lasting 4-10 days, providing little insights into how RARs vary with time. Objective: To describe how RAR parameters can vary or evolve with time (~months). Design Setting and Participants: 48 very long actograms ("VLAs", ≥90 days in duration) were identified from subjects enrolled in the STAGES (Stanford Technology, Analytics and Genomics in Sleep) study, a prospective cross-sectional, multi-site assessment of individuals > 13 years of age that required diagnostic polysomnography to address a sleep complaint. A single 3-year long VLA (author GD) is also described. Exposures/Intervention: None planned. Main Outcomes and Measures: For each VLA, we assessed the following parameters in 14-day windows: circadian/ultradian spectrum, pseudo-F statistic ("F"), cosinor amplitude, intradaily variability, interdaily stability, acrophase and estimates of "sleep" and non-wearing. Results: Included STAGES subjects (n = 48, 30 female) had a median age of 51, BMI of 29.4kg/m2, Epworth Sleepiness Scale score (ESS) of 10/24 and a median recording duration of 120 days. We observed marked within-subject undulations in all six RAR parameters, with many subjects displaying ultradian rhythms of activity that waxed and waned in intensity. When appraised at the group level (nomothetic), averaged RAR parameters remained remarkably stable over a ~4 month recording period. Cohort-level deficits in average RAR robustness associated with unemployment or high BMI (>29.4) also remained stable over time. Conclusions and Relevance: Through an exemplary set of months-long wrist actigraphy recordings, this study quantitatively depicts the longitudinal stability and dynamic range of human rest-activity rhythms. We propose that continuous and long-term actigraphy may have broad potential as a holistic, transdiagnostic and ecologically valid monitoring biomarker of changes in chronobiological health. Prospective recordings from willing subjects will be necessary to precisely define contexts of use.

A critical role for cyclin E in cell fate determination in the central nervous system of Drosophila melanogaster.

We have examined the process by which cell diversity is generated in neuroblast (NB) lineages in the central nervous system of Drosophila melanogaster. Thoracic NB6-4 (NB6-4t) generates both neurons and glial cells, whereas NB6-4a generates only glial cells in abdominal segments. This is attributed to an asymmetric first division of NB6-4t, localizing prospero (pros) and glial cell missing (gcm) only to the glial precursor cell, and a symmetric division of NB6-4a, where both daughter cells express pros and gcm. Here we show that the NB6-4t lineage represents the ground state, which does not require the input of any homeotic gene, whereas the NB6-4a lineage is specified by the homeotic genes abd-A and Abd-B. They specify the NB6-4a lineage by down-regulating levels of the G1 cyclin, DmCycE (CycE). CycE, which is asymmetrically expressed after the first division of NB6-4t, functions upstream of pros and gcm to specify the neuronal sublineage. Loss of CycE function causes homeotic transformation of NB6-4t to NB6-4a, whereas ectopic CycE induces reverse transformations. However, other components of the cell cycle seem to have a minor role in this process, suggesting a critical role for CycE in regulating cell fate in segment-specific neural lineages.

Notch and Wnt signals cooperatively control cell proliferation and tumorigenesis in the intestine.

Notch and Wnt signals play essential roles in intestinal development and homeostasis, yet how they integrate their action to affect intestinal morphogenesis is not understood. We examined the interplay between these two signaling pathways in vivo, by modulating Notch activity in mice carrying either a loss- or a gain-of-function mutation of Wnt signaling. We find that the dramatic proliferative effect that Notch signals have on early intestinal precursors requires normal Wnt signaling, whereas its influence on intestinal differentiation appears independent of Wnt. Analogous experiments in Drosophila demonstrate that the synergistic effects of Notch and Wnt are valid across species. We also demonstrate a striking synergy between Notch and Wnt signals that results in inducing the formation of intestinal adenomas, particularly in the colon, a region rarely affected in available mouse tumor models, but the primary target organ in human patients. These studies thus reveal a previously unknown oncogenic potential of Notch signaling in colorectal tumorigenesis that, significantly, is supported by the analysis of human tumors. Importantly, our experimental evidence raises the possibility that Notch activation might be an essential initial event triggering colorectal cancer.

Oral health-related KAP among 11- to 12-year-old school children in a government-aided missionary school of Bangalore city.

BACKGROUND: To organize community-oriented oral health promotion programs systematic analysis of the oral health situation would be needed, including information on oral health knowledge, attitudes, and practices (KAP). AIM: The aim of this study was to assess knowledge, attitude, and practice (KAP) toward oral health among 11 to 12-year-old school children in a government-aided missionary school of Bangalore city. MATERIALS AND METHODS: The study group comprised of 212 children (Male: 108; Female; 104) who were in the age group of 11-12 years studying in a government-aided missionary school of Bangalore city. Data on oral health KAP were collected by means of a self-administered questionnaire. Statistical significance was determined by Chi-square test. RESULTS: This survey found that only 38.5% of the children brush their teeth two or more times a day. Pain and discomfort from teeth (35.1%) were common while dental visits were infrequent. Fear of the dentist was the main cause of irregular visit in 46.1% of study participants. High proportion of study participants reported having hidden sugar at least once a day: soft drinks (32.1%), milk with sugar (65.9%), and tea with sugar (56.1%). It was found that 5.4% and 3.9% of study participants smoke and chew tobacco, respectively. CONCLUSION: Results of this study suggest that oral health KAP of study participants are poor and needs to be improved. Systematic community-oriented oral health promotion programs are needed to improve oral health KAP of school children.

Provocative ideas on human placental biology: A prerequisite for prevention and treatment of neonatal health challenges.

A 2-day invite-only meeting on generating "Provocative Ideas on human placental research" was organized on 1-2 December 2015 at the Translational Health Science and Technology Institute, Faridabad. This meeting was sponsored by Department of Biotechnology, Ministry of Science and Technology, Govt. of India. The objectives of this meeting were the critical evaluation of placental physiology and its development. Special emphasis was placed on understanding the consequences and implications of placental development in sustenance of pregnancy and in pregnancy-associated complications such as preeclampsia, intrauterine growth restriction, and preterm birth. This meeting brought together experienced as well as novice clinicians and biologists who have a keen interest in the field of placental biology, including development of new technologies and methods for evaluating the role of placenta in predicting pregnancy outcomes. The meeting primarily focused on (i) high-throughput "-omics" approaches, (ii) maternal nutrition and placental function, (iii) placental infection and inflammation, (iv) real-time evaluation of placental development: tools for placental research, and (v) epidemiologic relevance of placental-based research. Unanimous consensus emerged among the participants to carry out additional work focused on these areas. In this article, we summarize the talks and review the published literature on the above-mentioned niches. As a direct outcome of this meeting, a request for applications has been announced by the Department of Biotechnology, Government of India, for pursuing research in this vital but understudied domain.

The Notch-mediated hyperplasia circuitry in Drosophila reveals a Src-JNK signaling axis.

Notch signaling controls a wide range of cell fate decisions during development and disease via synergistic interactions with other signaling pathways. Here, through a genome-wide genetic screen in Drosophila, we uncover a highly complex Notch-dependent genetic circuitry that profoundly affects proliferation and consequently hyperplasia. We report a novel synergistic relationship between Notch and either of the non-receptor tyrosine kinases Src42A and Src64B to promote hyperplasia and tissue disorganization, which results in cell cycle perturbation, JAK/STAT signal activation, and differential regulation of Notch targets. Significantly, the JNK pathway is responsible for the majority of the phenotypes and transcriptional changes downstream of Notch-Src synergy. We previously reported that Notch-Mef2 also activates JNK, indicating that there are commonalities within the Notch-dependent proliferation circuitry; however, the current data indicate that Notch-Src accesses JNK in a significantly different fashion than Notch-Mef2.

Professional practice among woman dentist.

OBJECTIVE: This review aims to give an inside view of professional career of a women dentist, addresses the unique demands of being a woman dentist, and highlight ways to address these issues. MATERIALS AND METHODS: The Medline database, scholarly literature, and informal literature were considered for this review. RESULTS: Working hours of female dentists do not differ significantly from the working hours of their male counterparts, until they have children. The female dentists' working hours showed a distinct drop as soon as they started a family. It was also found that women dentists are more likely to take career break. It is clear that childrearing and family responsibilities have a great impact on women's working life. Significant differences between males and females in work title and specialization were evident in an academic institution. Due to the societal orientation which regards women as primarily home makers, the responsibilities for family caretaking continues to fall disproportionately on women, and this fact could explain why women abandon their careers in the advanced stages. CONCLUSIONS: Efforts should be made to identify and reduce barriers to women's advancement in dentistry.

Negative regulation of Egfr/Ras pathway by Ultrabithorax during haltere development in Drosophila.

In Drosophila, wings and halteres are the dorsal appendages of the second and third thoracic segments, respectively. In the third thoracic segment, homeotic selector gene Ultrabithorax (Ubx) suppresses wing development to mediate haltere development (E.B. Lewis, 1978. A gene complex controlling segmentation in Drosophila. Nature 276, 565-570). Halteres lack stout sensory bristles of the wing margin and veins that reticulate the wing blade. Furthermore, wing and haltere epithelia differ in the size, shape, spacing and number of cuticular hairs. The differential development of wing and haltere, thus, constitutes a good genetic system to study cell fate determination. Here, we report that down-regulation of Egfr/Ras pathway is critical for haltere fate specification: over-expression of positive components of this pathway causes significant haltere-to-wing transformations. RNA in situ, immunohistochemistry, and epistasis genetic experiments suggest that Ubx negatively regulates the expression of the ligand vein as well as the receptor Egf-r to down-regulate the signaling pathway. Electromobility shift assays further suggest that Egf-r is a potential direct target of Ubx. These results and other recent findings suggest that homeotic genes may regulate cell fate determination by directly regulating few steps at the top of the hierarchy of selected signal transduction pathways.

Signaling interactions between squamous and columnar epithelia of the Drosophila wing disc.

Understanding the interactions between distinct epithelial cells would help us to understand the development of tissues. Drosophila imaginal discs, which are made up of two types of epithelial cells, provide good model systems for such studies. The disc proper or the columnar epithelial cells are apposed to a layer of squamous epithelial cells (the peripodial membrane). We have examined organization of peripodial and disc proper cells vis-à-vis their polarity since cell polarity plays an important role in the polarized transport of signaling molecules. With the help of polarity-specific cell markers, we have observed that apical surfaces of peripodial and disc proper cells face each other. This provides the cellular basis for the recently demonstrated signaling interactions between peripodial and disc proper cells during disc patterning. We also report significant similarities as well as differences between peripodial and disc proper cells in Engrailed-dependent wingdisc-patterning events, which make them an appropriate model system for studying the mechanism of diffusion of signal molecules, such as Hedgehog. Results with wild-type and two mutant forms of Hedgehog suggest that direct cell-cell contact is a requirement for the movement of wild-type Hedgehog signal and reconfirm that cholesterol-modification of Hedgehog makes it a short-range signaling molecule by restricting its movement.

Cyclin E acts under the control of Hox-genes as a cell fate determinant in the developing central nervous system.

The mechanisms controlling the generation of cell diversity in the central nervous system belong to the major unsolved problems in developmental biology. The fly Drosophila melanogaster is a suitable model system to examine these mechanisms at the level of individually identifiable cells. Recently, we have provided evidence that CyclinE--largely independent of its role in cell proliferation--plays a critical role in the specification of neural stem cells (neuroblasts). CycE specifies neuronal fate within neuroblast lineages by acting upstream of glial factors (prospero and glial cell missing), whereby levels of CycE are controlled by homeotic genes, the master control genes regulating segment specific development. Considering the general relevance of CycE and homeotic genes in developing organisms, it seems likely that this mechanism has been conserved among species to contribute to regional diversification in the CNS.

Egfr/Ras pathway mediates interactions between peripodial and disc proper cells in Drosophila wing discs.

All imaginal discs in Drosophila are made up of a layer of columnar epithelium or the disc proper and a layer of squamous epithelium called the peripodial membrane. Although the developmental and molecular events in columnar epithelium or the disc proper are well understood, the peripodial membrane has gained attention only recently. Using the technique of lineage tracing, we show that peripodial and disc proper cells arise from a common set of precursors cells in the embryo, and that these cells diverge in the early larval stages. However, peripodial and disc proper cells maintain a spatial relationship even after the separation of their lineages. The peripodial membrane plays a significant role during the regional subdivision of the wing disc into presumptive wing, notum and hinge. The Egfr/Ras pathway mediates this function of the peripodial membrane. These results on signaling between squamous and columnar epithelia are particularly significant in the context of in vitro studies using human cell lines that suggest a role for the Egfr/Ras pathway in metastasis and tumour progression.

Genetic characterization of the Drosophila homologue of coronin.

We report cloning and characterization of coro, which codes for the Drosophila homologue of the F-actin binding protein coronin. Viable alleles of coro produce a variety of phenotypes in leg, wing and eye development, which are similar to the phenotypes observed as a result of mutations in genes associated with the actin cytoskeleton and/or membrane trafficking. Homozygous lethal mutations in coro results in the disruption of the actin cytoskeleton in wing imaginal discs. Formation of both basolateral septate junctions and apical adherens junctions are also adversely affected in epithelial cells. Both viable and lethal alleles of coro show genetic interactions with syntaxin1A, a gene required for membrane trafficking. They also show enhanced response to over-expression of Decapentaplegic (Dpp) and its receptor Thick vein. Tracing of Dpp morphogen using a Dpp::GFP fusion construct suggested defects in the endocytic pathway, which resulted in uniform distribution of Dpp along the AP axis rather than a gradient from the AP boundary. Our results provide a genetic link between endocytosis/exocytosis events involving F actin-coated vesicles and the establishment of morphogen gradient.

Oral health-related KAP among 11- to 12-year-old school children in a government-aided missionary school of Bangalore city.

BACKGROUND: To organize community-oriented oral health promotion programs systematic analysis of the oral health situation would be needed, including information on oral health knowledge, attitudes, and practices (KAP). AIM: The aim of this study was to assess knowledge, attitude, and practice (KAP) toward oral health among 11 to 12-year-old school children in a government-aided missionary school of Bangalore city. MATERIALS AND METHODS: The study group comprised of 212 children (Male: 108; Female; 104) who were in the age group of 11-12 years studying in a government-aided missionary school of Bangalore city. Data on oral health KAP were collected by means of a self-administered questionnaire. Statistical significance was determined by Chi-square test. RESULTS: This survey found that only 38.5% of the children brush their teeth two or more times a day. Pain and discomfort from teeth (35.1%) were common while dental visits were infrequent. Fear of the dentist was the main cause of irregular visit in 46.1% of study participants. High proportion of study participants reported having hidden sugar at least once a day: soft drinks (32.1%), milk with sugar (65.9%), and tea with sugar (56.1%). It was found that 5.4% and 3.9% of study participants smoke and chew tobacco, respectively. CONCLUSION: Results of this study suggest that oral health KAP of study participants are poor and needs to be improved. Systematic community-oriented oral health promotion programs are needed to improve oral health KAP of school children.