Pro-oxidant/antioxidant balance controls pancreatic β-cell differentiation through the ERK1/2 pathway

During embryogenesis, the intrauterine milieu affects cell proliferation, differentiation, and function by modifying gene expression in susceptible cells, such as the pancreatic β-cells. In this limited energy environment, mitochondrial dysfunction can lead to overproduction of reactive oxygen species (ROS) and to a decline in β-cell function. In opposition to this toxicity, ROS are also required for insulin secretion. Here we investigated the role of ROS in β-cell development. Surprisingly, decreasing ROS production in vivo reduced β-cell differentiation. Moreover, in cultures of pancreatic explants, progenitors were highly sensitive to ROS stimulation and responded by generating β-cells. ROS enhanced β-cell differentiation through modulation of ERK1/2 signaling. Gene transfer and pharmacological manipulations, which diminish cellular ROS levels, also interfered with normal β-cell differentiation. This study highlights the role of the redox balance on β-cell development and provides information that will be useful for improving β-cell production from embryonic stem cells, a step in cell therapy for diabetes.

Inhibitory effect of 2-(piperidinoethoxyphenyl)-3-(4-hydroxyphenyl)-2H-benzo(b)pyran (K-1) on human primary endometrial hyperplasial cells mediated via combined suppression of Wnt/β-catenin signaling and PI3K/Akt survival pathway

Endometrial hyperplasia is a precursor to the most common gynecologic cancer diagnosed in women. Apart from estrogenic induction, aberrant activation of the Wnt/β-catenin signal is well known to correlate with endometrial hyperplasia and its carcinoma. The benzopyran compound 2-(piperidinoethoxyphenyl)-3-(4-hydroxyphenyl)-2H-benzo (b) pyran(K-1), a potent antiestrogenic agent, has been shown to have apoptosis-inducing activity in rat uterine hyperplasia. The current study was undertaken to explore the effect of the benzopyran compound K-1 on growth and Wnt signaling in human endometrial hyperplasial cells. Primary culture of atypical endometrial hyperplasial cells was characterized by the epithelial cell marker cytokeratin-7. Results revealed that compound K-1 reduced the viability of primary endometrial hyperplasial cells and expression of ERα, PR, PCNA, Wnt7a, FZD6, pGsk3β and β-catenin without affecting the growth of the primary culture of normal endometrial cells. The β-catenin target genes CyclinD1 and c-myc were also found to be reduced, whereas the expression of axin2 and Wnt/β-catenin signaling inhibitor Dkk-1 was found to be upregulated, which caused the reduced interaction of Wnt7a and FZD6. Nuclear accumulation of β-catenin was found to be decreased by compound K-1. K-1 also suppressed the pPI3K/pAkt survival pathway and induced the cleavage of caspases and PARP, thus subsequently causing the apoptosis of endometrial hyperplasial cells. In conclusion, compound K-1 suppressed the growth of human primary endometrial hyperplasial cells through discontinued Wnt/β-catenin signaling and induced apoptosis via inhibiting the PI3K/Akt survival pathway.

Human IL10 gene repression by Rev-erbα ameliorates Mycobacterium tuberculosis clearance

Nuclear receptors modulate macrophage effector functions, which are imperative for clearance or survival of mycobacterial infection. The adopted orphan nuclear receptor Rev-erbα is a constitutive transcriptional repressor as it lacks AF2 domain and was earlier shown to be present in macrophages. In the present study, we highlight the differences in the relative subcellular localization of Rev-erbα in monocytes and macrophages. The nuclear localization of Rev-erbα in macrophages is subsequent to monocyte differentiation. Expression analysis of Rev-erbα elucidated it to be considerably more expressed in M1 phenotype in comparison with M2. Rev-erbα overexpression augments antimycobacterial properties of macrophage by keeping IL10 in a basal repressed state. Further, promoter analysis revealed that IL10 promoter harbors a Rev-erbα binding site exclusive to humans and higher order primates and not mouse, demonstrating a species barrier in its functionality. This direct gene repression is mediated by recruitment of co-repressors NCoR and HDAC3. In addition, our data elucidate that its overexpression reduced the survival of intracellular pathogen Mycobacterium tuberculosis by enhancing phagosome lysosome maturation, an event resulting from IL10 repression. Thus, these findings suggest that Rev-erbα bestows protection against mycobacterial infection by direct gene repression of IL10 and thus provide a novel target in modulating macrophage microbicidal properties.

Mycobacterium tuberculosis modulates macrophage lipid-sensing nuclear receptors PPARγ and TR4 for survival

Mycobacterium tuberculosis-macrophage interactions are key to pathogenesis and clearance of these bacteria. Although interactions between M. tuberculosis-associated lipids and TLRs, non-TLRs, and opsonic receptors have been investigated, interactions of these lipids and infected macrophage lipid repertoire with lipid-sensing nuclear receptors expressed in macrophages have not been addressed. In this study, we report that M. tuberculosis-macrophage lipids can interact with host peroxisome proliferator-activated receptor γ and testicular receptor 4 to ensure survival of the pathogen by modulating macrophage function. These two lipid-sensing nuclear receptors create a foamy niche within macrophage by modulating oxidized low-density lipoprotein receptor CD36, phagolysosomal maturation block by induction of IL-10, and a blunted innate response by alternative polarization of the macrophages, which leads to survival of M. tuberculosis. These results also suggest possible heterologous ligands for peroxisome proliferator-activated receptor γ and testicular receptor 4 and are suggestive of adaptive or coevolution of the host and pathogen. Relative mRNA expression levels of these receptors in PBMCs derived from clinical samples convincingly implicate them in tuberculosis susceptibility. These observations expose a novel paradigm in the pathogenesis of M. tuberculosis amenable for pharmacological modulation.

Development and characterization of novel cell lines from Etroplus suratensis and their applications in virology, toxicology and gene expression

Four novel cell lines from tissues of eye, gill, kidney and brain of Etroplus suratensis were developed and characterized. The cell lines of eye, gill, kidney and brain were sub-cultured for 245, 185, 170 and 90 passages, respectively, since 2008. These cell lines showed predominantly epithelial-like cells. Effects of temperature and foetal bovine serum concentration on the growth of these cell lines were examined and optimum growth was found at the temperature of 28° C with 20% foetal bovine serum. All the four cell lines were successfully cryopreserved and revived at different passage levels. Cell-cycle analysis of these cell lines was carried out by fluorescence-activated cell sorting. Polymerase chain reaction (PCR) products obtained from the cells and tissues of E. suratensis with primers specific to the conserved region of 16S ribosomal RNA and cytochrome oxidase I genes of E. suratensis revealed the origin of cell lines from E. suratensis. Antibodies raised against the tissues and cells of eye, kidney and gill were highly cross reacted to their specific tissue and cells of E. suratensis. Chromosomal analysis revealed that E. suratensis cells have a normal diploid karyotype with 2n = 48. The cells of these cell lines were successfully transfected with pEGFP vector DNA. The eye (IEE), gill (IEG) and kidney (IEK) cell lines were found to be susceptible to nodavirus but resistant to infectious pancreatic necrosis virus (IPNV). The cells of gill, kidney and eye were applied to test the cytotoxicity of tannery effluents.

2,3-Diaryl-2H-1-benzopyran derivatives interfere with classical and non-classical estrogen receptor signaling pathways, inhibit Akt activation and induce apoptosis in human endometrial cancer cells

OBJECTIVES

The present study was undertaken to explore the mechanism of anti-proliferative action of benzopyran compound D1 (2-[piperidinoethoxyphenyl]-3-phenyl-2H-benzopyran) and its hydroxy-(D2) and methoxy-(D3) derivatives in Ishikawa and human primary endometrial adenocarcinoma cells.

METHODS

Transcriptional activation assays were performed using luciferase reporter system and cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). The stage of cell cycle was determined by flow-cytometry and real time analysis of cyclinE1 and cdc2 genes. The apoptotic effects were measured by AnnexinV/PI staining and TUNEL. The expression of PCNA, cyclinD1, pAkt, XIAP, cleaved caspase-9, -3, PARP, Bax and Bcl2 were determined by immunoblotting. The caspase-3 activity and mitochondrial membrane potential were measured by colorimetric assay.

RESULTS

All three compounds inhibited E(2)-induced ERE- and AP-1-mediated transactivation and proliferation in endometrial adenocarcinoma cells dose-dependently. Compound D1 caused the arrest of cells in the G(2) phase while D2 and D3 caused arrest in G(1) phase of the cell cycle. All compounds interfered with Akt activation, decreased XIAP expression leading to an increased cleavage of caspase-9, -3, PARP, increased Bax/Bcl2 ratio and caspase-3 activity.

CONCLUSION

Findings suggest that benzopyran derivatives inhibit cellular proliferation via modulating ER-dependent classical and non-classical signaling mechanisms, interfere with Akt activation and induce apoptosis via intrinsic pathway in endometrial adenocarcinoma cells.

Establishment and characterization of a fin cell line from Indian walking catfish, Clarias batrachus (L.)

A new cell line, Indian Catfish Fin, derived from the fin tissue of Indian walking catfish, Clarias batrachus, was established and characterized. The cell line grew well in Leibovitz's L-15 medium supplemented with 15% foetal bovine serum (FBS) and has been subcultured more than 110 times since its initiation in 2007. The cells were able to grow at a range of temperature from 28 to 37 °C with optimal growth at 28 °C. The cell line predominantly consists of fibroblast-like cells. The growth rate of fin cells increased as the FBS concentration increased from 2% to 20% at 28 °C with optimum growth at a concentration of 15% or 20% and poor growth at a concentration of 5%. The cells were found to be susceptible to fish nodavirus and IPNV-ab and infection was confirmed by cytopathic effect and reverse transcriptase-polymerase chain reaction. PCR amplification of mitochondrial 12S rRNA using primers specific to C. batrachus confirmed the catfish origin of the cell line. The cell line was characterized further by immunocytochemistry, transfection efficiency with pEGFP-N1 and cell cycle analysis by fluorescent-activated cell sorting.

Development and characterization of cell lines derived from rohu, Labeo rohita (Hamilton), and catla, Catla catla (Hamilton)

Two new cell lines, designated RE and CB, were derived from the eye of rohu, Labeo rohita, and the brain of catla, Catla catla, respectively. The cell lines were maintained in Leibovitz's L-15 supplemented with 20% foetal bovine serum. The RE cell line was sub-cultured for more than 70 passages and the CB cell line for more than 35 passages. The RE cells are rounded and consist predominantly of epithelial cells. The CB cell line consists of predominantly fibroblastic-like cells. Both cell lines are able to grow at temperatures between 25 and 32 degrees C with an optimum of 28 degrees C. The growth rate of the cells increased as the foetal bovine serum concentration increased from 2% to 20% at 28 degrees C, with optimum growth at concentrations of 15% or 20% foetal bovine serum. The cells were successfully cryopreserved and revived at different passage levels. The cell lines were not susceptible to four marine fish viruses. Extracellular products from Aeromonas sp. were toxic to the cell lines. When the cells were transfected with plasmid eukaryotic green fluorescent protein (pEGFP [Clontech, Carlsbad, CA, USA]) vector DNA, a significant fluorescent signal was observed suggesting that these cell lines could be a useful tool for transgenic and genetic manipulation studies. Polymerase chain reaction amplification of mitochondrial 12S rRNA from rohu and catla confirmed that the cell lines originated from these fish species. The cell lines were further characterized by immunocytochemistry using confocal laser scanning microscopy.

Effect of Ru-Mn redox interactions on the hole carrier density in pulsed electron deposited La(1-x)Pb(x)Mn(0.8)Ru(0.2)O(3) (0.2≤x≤0.4) thin films

Pulsed electron deposited thin films of Ru substituted La(1-x)Pb(x)Mn(0.8)Ru(0.2)O(3) (0.2≤x≤0.4) show an increase in the magneto-resistance ratio by ∼5-15% at the respective metal to insulator transition (T(MIT)) temperature when compared to the parent La(0.6)Pb(0.4)MnO(3) thin film. A systematic decrease in T(MIT) is observed from ∼310 to ∼260 K when the hole (Pb) concentration varies from 40 to 20% with constant 20% Ru substitution at the Mn site. The x-ray rocking curve and high-resolution transmission electron microscopy (HRTEM) images of the thin films suggest that Ru occupies the Mn site and shows epitaxial growth of the films on the LaAlO(3) (LAO) substrate. Transport and magneto-resistive properties show that Ru substitution maintains a considerable hole carrier density (due to Mn(4+):t(2g)(3)e(g)(0)/Ru(5+):t(2g)(3)e(g)(0)) even for La(0.8)Pb(0.2)Mn(0.8)Ru(0.2)O(3) (8282) composition, which influences the double exchange interactions.

273 EXPRESSION PATTERN OF CONNEXIN 43 (Cx43) AND POLY-(A) POLYMERASE (PAP) GENES IN BUFFALO (BUBALUS BUBALIS) EMBRYOS PRODUCED IN VITRO

Polyadenylation of pre-mRNA is carried out by poly-(A) polymerase (PAP), and study of the transcription pattern of this gene is said to indicate the developmental competence of the embryos. Connexin 43 (Cx43) is one of the important gap junction proteins that controls growth, cellular differentiation, and embryonic development. The objective of the present investigation was to study the expression pattern of PAP and Cx43 genes in buffalo (Bubalus bubalis) embryos produced in vitro. Embryos were produced from the slaughterhouse ovaries using standard IVMFC protocol (Rajhans et al. 2006 J. Reprod. Fertil. Dev. 18, 253–254). Briefly, oocytes were aspirated from follicles (2–8 mm in diameter) and matured in vitro in TCM-199 supplemented with 10% FCS and epidermal growth factor (20 ng mL-1) for 24 h. Presumptive zygotes after 18 h of fertilization were cultured in mSOF containing insulin-like growth factor-1 (100 ng mL-1) and β-mercaptoethanol (100 �M) for 9 days or until blastocyst formation, whichever was earlier. Pools of immature (n = 200), in vitro-matured (n = 200), oocytes and embryos (2–4 cell, n = 83; 8–16 cell, n = 80; morula, n = 77), and blastocysts (n = 40) were collected for mRNA isolation. Immature and in vitro-matured oocytes were treated with 1X trypsin-EDTA solution to remove the attached cumulus and then washed with TCM-199 before mRNA isolation to avoid any contamination of these cells during RNA isolation. mRNA from each pool was isolated using a commercially available direct mRNA isolation kit (Oligotex Direct mRNA kit; Qiagen, Valencia, CA, USA). cDNA was prepared using specific reverse primer and M-MLV RT in 20 �L reaction volume following manufacturer's instructions. Polymerase chain reaction was done for 35 cycles with annealing temperatures of 60�C and 58�C for 252 bp of PAP and 425 bp of Cx43, respectively. Amplicons were subjected to restriction endonuclease digestion for further confirmation of expressed genes. RT-PCR amplicon of PAP was digested with HaeIII to obtain characteristic band patterns at 119 bp and 133 bp, and Cx43 RT-PCR amplicon was digested with EcoR1 to obtain characteristic band patterns at 137 bp and 288 bp. While PAP expression could be detected in all stages of developing embryos starting from immature oocytes to blastocyst stage, Cx43 mRNA was detected in immature oocytes to morula stage but not in blastocyst-stage embryos. It could be concluded that the expression patterns of PAP and Cx43 genes in buffalo embryos produced in vitro are similar to those of cattle embryos.

Renal artery stenosis and a functioning hilar paraganglioma: a rare cause of renovascular hypertension--a case report

Surgically correctable causes of hypertension are uncommon. Simultaneous occurrence of 2 such causes in the same individual is extremely rare. The authors describe a 25-year-old woman with congenital erythrocytosis, renal artery stenosis, and a paraganglioma. The possible mechanisms of renal artery stenosis in the presence of a catecholamine-secreting tumor are discussed.

Regulation of catalytic function by molecular association: structure of phospholipase A2 from Daboia russelli pulchella (DPLA2) at 1.9 A resolution

The crystal structure of phospholipase A(2) from the venom of Daboia russelli pulchella has been refined to an R factor of 0.216 using 17,922 reflections to 1.9 A resolution. The structure contains two crystallographically independent molecules in the asymmetric unit. The overall conformations of the two molecules are essentially the same except for three regions, namely the calcium-binding loop including Trp31, the beta-wing and the C-terminal residues 119-131. Although these differences have apparently been caused by molecular packing, they seem to have functional relevance. Particularly noteworthy is the conformation of Trp31, which is favourable for substrate binding in one molecule as it is aligned with one of the side walls of the hydrophobic channel, whereas in the other molecule it is located at the mouth of the channel, thereby blocking the entry of substrates leading to loss of activity. This feature is unique to the present structure and does not occur in the dimers and trimers of other PLA(2)s.

Purification, crystallization and preliminary X-ray diffraction studies of disintegrin (schistatin) from saw-scaled viper (Echis carinatus)

This is the first report of crystallographic data on a disintegrin molecule from any source. The heterodimeric disintegrin with a molecular weight of 14 kDa from Echis carinatus venom is a potent antagonist of alpha4 integrins. The intact disintegrin, containing two subunits A and B, was isolated and purified using affinity and ion-exchange columns. It has been crystallized using 1.6 M ammonium sulfate as a precipitating agent. The crystals grew to dimensions of 0.25 x 0.20 x 0.20 mm and diffracted to 2.5 A resolution. The crystals belong to space group I4(1)22, with unit-cell parameters a = b = 91.7, c = 55.1 A. Assuming a molecular weight of 14 kDa, a V(M) of 2.1 A(3) Da(-1) is obtained for one molecule of disintegrin in the asymmetric unit.

Preliminary X-ray diffraction studies of the external functional unit RtH2-e from the Rapana thomasiana

The 'external' oxygenated functional unit RtH2-e of the Rapana hemocyanin subunit RHSS2 was isolated and crystallized. X-ray intensity data to 3.3 A resolution have been collected at 100 K and the structure has been solved using the molecular-replacement method. The space group is assigned to be the tetragonal P4(3)2(1)2, with unit-cell parameters a = b = 105.5, c = 375.0 A.

Incidence of Alzheimer's disease in a rural community in India: the Indo-US study

OBJECTIVE

To determine overall and age-specific incidence rates of AD in a rural, population-based cohort in Ballabgarh, India, and to compare them with those of a reference US population in the Monongahela Valley of Pennsylvania.

METHODS

A 2-year, prospective, epidemiologic study of subjects aged > or =55 years utilizing repeated cognitive and functional ability screening, followed by standardized clinical evaluation using the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, and the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria for the diagnosis, and the Clinical Dementia Rating scale for the staging, of dementia and AD.

RESULTS

Incidence rates per 1000 person-years for AD with CDR > or =0.5 were 3.24 (95% CI: 1.48-6.14) for those aged > or =65 years and 1.74 (95% CI: 0.84-3.20) for those aged > or =55 years. Standardized against the age distribution of the 1990 US Census, the overall incidence rate in those aged > or =65 years was 4.7 per 1000 person-years, substantially lower than the corresponding rate of 17.5 per 1000 person-years in the Monongahela Valley.

CONCLUSION

These are the first AD incidence rates to be reported from the Indian subcontinent, and they appear to be among the lowest ever reported. However, the relatively short duration of follow-up, cultural factors, and other potential confounders suggest caution in interpreting this finding.

APOE polymorphism in a rural older population-based sample in India

Allele frequencies are most often reported from small convenience samples of unknown demographics and limited generalizability. We determined the distribution of apolipoprotein E genotype (APOE) and allele frequencies for a large, well-defined, representative, rural, population-based sample (n = 4450) aged 55-95 years in Ballabgarh, in the northern Indian state of Haryana. The overall APOE E*2, E*3, and E*4 allele frequencies were 0.039, 0.887, and 0.073, respectively; frequencies are also reported by age, sex, and religious/caste groups. The APOE*4 frequency is among the lowest reported anywhere in the world. APOE allele frequencies did not vary significantly by age or sex in this study. To our knowledge, this is the largest Indian sample ever genotyped for the APOE polymorphism. The representativeness of the sample and its known demographics provide a much-needed normative background for studies of gene-disease associations.