Myc and the Tip60 chromatin remodeling complex control neuroblast maintenance and polarity in Drosophila.

Stem cells establish cortical polarity and divide asymmetrically to simultaneously maintain themselves and generate differentiating offspring cells. Several chromatin modifiers have been identified as stemness factors in mammalian pluripotent stem cells, but whether these factors control stem cell polarity and asymmetric division has not been investigated so far. We addressed this question in Drosophila neural stem cells called neuroblasts. We identified the Tip60 chromatin remodeling complex and its interaction partner Myc as regulators of genes required for neuroblast maintenance. Knockdown of Tip60 complex members results in loss of cortical polarity, symmetric neuroblast division, and premature differentiation through nuclear entry of the transcription factor Prospero. We found that aPKC is the key target gene of Myc and the Tip60 complex subunit Domino in regulating neuroblast polarity. Our transcriptome analysis further showed that Domino regulates the expression of mitotic spindle genes previously identified as direct Myc targets. Our findings reveal an evolutionarily conserved functional link between Myc, the Tip60 complex, and the molecular network controlling cell polarity and asymmetric cell division.

The complex portal--an encyclopaedia of macromolecular complexes.

The IntAct molecular interaction database has created a new, free, open-source, manually curated resource, the Complex Portal (www.ebi.ac.uk/intact/complex), through which protein complexes from major model organisms are being collated and made available for search, viewing and download. It has been built in close collaboration with other bioinformatics services and populated with data from ChEMBL, MatrixDB, PDBe, Reactome and UniProtKB. Each entry contains information about the participating molecules (including small molecules and nucleic acids), their stoichiometry, topology and structural assembly. Complexes are annotated with details about their function, properties and complex-specific Gene Ontology (GO) terms. Consistent nomenclature is used throughout the resource with systematic names, recommended names and a list of synonyms all provided. The use of the Evidence Code Ontology allows us to indicate for which entries direct experimental evidence is available or if the complex has been inferred based on homology or orthology. The data are searchable using standard identifiers, such as UniProt, ChEBI and GO IDs, protein, gene and complex names or synonyms. This reference resource will be maintained and grow to encompass an increasing number of organisms. Input from groups and individuals with specific areas of expertise is welcome.

Quality of Life in Locally Advanced Carcinoma Rectum Patients During Various Phases of NACRT: An Indian Perspective.

In low- and middle-income countries (LMICs) including India, cancer patients have a poor prognosis because of late diagnosis and cases already grown to advanced stages, low cancer awareness and skewed cancer care facilities. In India, the incidence of colorectal cancer (CRC) is ranked the 4th most common (6.4%) in males and the 5th most common (3.4%) in females. The improvement in the cure rate of rectal cancer has increased life expectancy, and assessment of the quality of life (QoL) in these patients has become a fundamental requirement. Little is known about how the patients perceive these adverse effects during curatively intended radiotherapy. Although studies have investigated the various adverse effects that can occur with radiotherapy and chemotherapy in carcinoma rectum patients, these have not yet been critically appraised and synopsized to form a comprehensive review of their prevalence and effects on QoL. The study was designed to explore the QoL issues in locally advanced carcinoma rectum patients during various phases of neoadjuvant concurrent chemo-radiotherapy (NACCRT). The study was performed over a period of 2 years at a single super speciality cancer hospital in North India. Patients were selected as per the inclusion criteria and followed up with a standard questionnaire incorporating various aspects depicting QoL. The interview technique was used for collecting QoL data at four points, at baseline, midway during treatment, at the end of treatment and 4 weeks after completion of NACCRT, using EORTC QLQ C30, for QLQ CR29. Special care was taken to avoid observer bias in cases of language issues, and interpreters' services were utilised, and compared with the baseline pre-treatment scores, patients reported a statistically significant and large clinically meaningful change in the global health status, social functioning, fatigue (FACIT-F), appetite loss, anxiety, sore skin and male and female sexual function at the post-treatment time point. Statistically significant changes with moderate clinically meaningful changes were reported for the functional scales-physical, role and emotional functioning of the QLQ C30 questionnaire and body image and weight of the CR29 questionnaire. Similar moderate clinical changes were found in the symptom scales-fatigue, nausea and vomiting, insomnia, constipation and diarrhoea of QLQ C30 and stool frequency, embarrassment with bowel function, impotence and dyspareunia. These parameters returned to almost the pre-treatment values after 4 weeks of completion of NACRT. Since QoL is a relatively subjective variable, differences in human race, culture, education and social environment will have impacts on the results. International cooperation is needed to study the QoL in patients with multiple cultural backgrounds. The existing QoL questionnaire tools have been designed with Western countries in mind, and we did face multiple social issues. We suggest that many similar multicentre studies shall be required to essentially tap the accurate QoL-related issues keeping in mind the diverse social, economic, racial and educational backgrounds. As we deal with the ever-increasing cancer menace and better life expectancy, QoL issues shall be a major determinant of treatment success besides primary treatment. These factors should form an integral part of treatment modality, and adequate counselling must be performed prior to initiation of care.

Correlation of haemoglobin and red cell indices with serum ferritin in Indian women in second and third trimester of pregnancy.

BACKGROUND: Iron deficiency anaemia (IDA) is the most common cause of anaemia in pregnancy in Indians and is associated with increased risk of low birth-weight infants. Studies from developed countries recommend iron supplementation based on serum ferritin levels. However, screening by serum ferritin is not feasible in all cases in India. This study was undertaken to document haematological profile of pregnant Indian women. METHODS: We studied the correlation between second and third trimester ferritin concentration and haemoglobin (Hb) and red cell indices in 100 consecutive ANC cases to select the best haematologic characteristic to identify women who needed iron therapy. Hb and red cell indices, RBC count, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, red cell distribution width were analysed and PBS studied to subtype anaemia if present. RESULTS: Proportion of iron deficiency anaemia in pregnancy was 34% and significant correlation was found between serum ferritin and RDW-CV% and TRBC. No correlation was found between ferritin levels and Hb, MCV, MCH and MCHC. Serum ferritin levels were <12 ng/mL in 30 out of 52 non-anaemic cases suggesting prevalence of sub-clinical iron deficiency in 58% cases. None of the red cell indices correlated with ferritin level in this group. Only TRBC showed some correlation with ferritin (r = -0.090, p > 0.05). CONCLUSION: All pregnant women in India should continue to get iron supplements unlike what is recommended in the developed countries where iron supplementation is based on serum ferritin levels.

Flow cytometry-based evaluation and enrichment of multiwalled carbon nanotube dispersions.

The uniform aqueous dispersion of carbon nanotubes (CNTs) is a vital but challenging task required for their utilization in most technologies. We propose and demonstrate a technique based on forward- and side-scatter analysis on a flow cytometer to characterize the components in a dispersion of multiwalled CNTs (MWCNTs). The method simultaneously distinguishes various MWCNT components such as short and long CNTs, nanotube bundles, and particulates. It also detects the emergence of new CNT populations as a result of centrifugation. We use this method, together with classical methods such as UV and Raman spectroscopy, to observe and study the multistep MWCNT dispersion process in various surfactants (Pluronic, Triton X-100, sodium dodecyl sulfate, and cetyl trimethylammonium bromide). On the basis of the distinct scatter patterns obtained, we confirm and elaborate the surfactant-assisted unzipping mechanism of MWCNT dispersion. We also show that the ultrasonic energy spent after MWCNT unbundling and unwinding can be minimized and the process optimized for each surfactant by correct end point detection through scatter analysis. The ability to enrich nanotube population in dispersion by using the sorting mode of a flow cytometer is confirmed by electron microscopy and Raman spectroscopy. This method can thus be used for observing and enriching MWCNT components and as a complementary technique to UV spectroscopy for studying and optimizing MWCNT dispersion in surfactants.

Synthesis of BF2 complexes of prodigiosin type oligopyrroles.

We developed a simple, facile route for the synthesis of BF(2) complexes of prodigiosin type oligopyrroles and their cholesterol conjugates. This route gives an access to synthesize any desired meso-aryl-substituted 3-pyrrolyl BODIPYs which were not easily accessible earlier.

Molecular profiling of stem cell-like female germ line cells in Drosophila delineates networks important for stemness and differentiation.

Stem cells can self-renew and produce daughter cells destined for differentiation. The precise control of the balance between these two outcomes is essential to ensure tissue homeostasis and to prevent uncontrolled proliferation resulting in tumor formation. As self-renewal and differentiation are likely to be controlled by different gene expression programs, unraveling the underlying gene regulatory networks is crucial for understanding the molecular logic of this system. In this study, we have characterized by next generation RNA sequencing (RNA-seq) the transcriptome of germline stem cell (GSC)-like cells isolated from bag of marbles (bam) mutant Drosophila ovaries and compared it to the transcriptome of germ line cells isolated from wild-type ovaries. We have complemented this dataset by utilizing an RNA-immunoprecipitation strategy to identify transcripts bound to the master differentiation factor Bam. Protein complex enrichment analysis on these combined datasets allows us to delineate known and novel networks essential for GSC maintenance and differentiation. Further comparative transcriptomics illustrates similarities between GSCs and primordial germ cells and provides a molecular footprint of the stem cell state. Our study represents a useful resource for functional studies on stem cell maintenance and differentiation.

Bazooka/PAR3 is dispensable for polarity in Drosophila follicular epithelial cells.

Apico-basal polarity is the defining characteristic of epithelial cells. In Drosophila, apical membrane identity is established and regulated through interactions between the highly conserved Par complex (Bazooka/Par3, atypical protein kinase C and Par6), and the Crumbs complex (Crumbs, Stardust and PATJ). It has been proposed that Bazooka operates at the top of a genetic hierarchy in the establishment and maintenance of apico-basal polarity. However, there is still ambiguity over the correct sequence of events and cross-talk with other pathways during this process. In this study, we reassess this issue by comparing the phenotypes of the commonly used baz(4) and baz(815-8) alleles with those of the so far uncharacterized baz(XR11) and baz(EH747) null alleles in different Drosophila epithelia. While all these baz alleles display identical phenotypes during embryonic epithelial development, we observe strong discrepancies in the severity and penetrance of polarity defects in the follicular epithelium: polarity is mostly normal in baz(EH747) and baz(XR11) while baz(4) and baz(815) (-8) show loss of polarity, severe multilayering and loss of epithelial integrity throughout the clones. Further analysis reveals that the chromosomes carrying the baz(4) and baz(815-8) alleles may contain additional mutations that enhance the true baz loss-of-function phenotype in the follicular epithelium. This study clearly shows that Baz is dispensable for the regulation of polarity in the follicular epithelium, and that the requirement for key regulators of cell polarity is highly dependent on developmental context and cell type.

All-trans retinoic acid loaded block copolymer nanoparticles efficiently induce cellular differentiation in HL-60 cells.

All-trans retinoic acid (atRA) is used in the differentiation therapy of Acute Promyelocytic Leukemia. However, its therapeutic success is limited by the appearance of relapse and recalcitrant cases, poor aqueous solubility and high degradability. In the current work, we prepared two types of atRA-loaded copolymer nanoparticles - PL1RA and PC1RA, based on poly(ethyleneglycol) (PEG)-poly(l-lactide) and PEG-poly(ε-caprolactone), respectively. We then evaluated their physico-chemical properties and compared their differentiation-inducing potential of HL-60 cells with free atRA. These nanoparticles were in the size range 100-150nm, possessed moderate colloidal stability and exhibited around 30% encapsulation efficiencies. In vitro release studies indicated pseudo-zero order release of a sustained nature, with PL1RA showing 71% and PC1RA exhibiting 84% drug release over a period of two weeks. Photostability measurements exhibited considerable increase in atRA photostability in the nanoparticle forms: 25% of the drug in PL1RA and 19% in PC1RA was intact as compared to only 5% for free atRA after 8h of light exposure. PL1RA and PC1RA exhibited efficacies comparable to free atRA in inducing HL-60 respiratory burst as assessed by nitroblue tetrazolium and 2',7'-dichlorodihydro fluorescein diacteate assays. The average CD11b expressions for atRA, PL1RA and PC1RA on day 5 of treatment were 58%, 49% and 60%, respectively. Post-differentiation apoptosis (∼40%) and reduction in mitochondrial transmembrane potentials (∼60-70%) were also comparable across all treatment groups. Therefore, our block copolymer nanoparticles, PL1RA and PC1RA, are attractive and effective vehicles for atRA delivery which maintain its activity and enhance its stability resulting in efficient induction of HL-60 differentiation.

Flow cytometry as a novel tool to evaluate and separate vesicles using characteristic scatter signatures.

Vesicles are usually characterized for their structure by microscopy or, less often, by the addition of fluorescent dyes in a flow cytometer. We present a new method of studying these structures and associated forms by forward and side scatter analysis on a flow cytometer which has the advantage of simultaneous handling of large population of vesicles to identify their shapes and lamellarities. The technique is suitable for several types of vesicular structures like Multivesicular vesicles (MVV), multilamellar and unilamellar vesicles. Characteristic signatures are given by tubular structures and fine features thereon allow detection of complex structures such as fused and ellipsoidal forms. Coexistence of tubular and spherical structures, such as those known to form when surfactants/salt solutions are diluted, can clearly be detected by the signature pattern, which separates into two distinctly identifiable populations. The population can be sorted or separated easily based on these signatures and such sorting has allowed us to confirm our findings by microscopic observations. This novel method can thus be used for concurrent observations of vesicle populations with dye or more advantageously without employing any fluorescent tag.