Expression of aromatase,androgen and estrogen receptors in peripheral target tissues in diabetes

Our previous studies have shown that diabetes in the male streptozotocin (STZ)-induced diabetic rat is characterized by a decrease in circulating testosterone and concomitant increase in estradiol levels. Interestingly, this increase in estradiol levels persists even after castration, suggesting extra-testicular origins of estradiol in diabetes. The aim of the present study was to examine whether other target organs of diabetes may be sources of estradiol. The study was performed in male Sprague–Dawley non-diabetic (ND), STZ-induced diabetic (D) and STZ-induced diabetic castrated (Dcas) rats (n = 8–9/group). 14 weeks of diabetes was associated with decreased testicular (ND, 26.3 ± 4.19; D, 18.4 ± 1.54; P < 0.05), but increased renal (ND, 1.83 ± 0.92; D, 7.85 ± 1.38; P < 0.05) and ocular (D, 23.4 ± 3.66; D, 87.1 ± 28.1; P < 0.05) aromatase activity. This increase in renal (Dcas, 6.30 ± 1.25) and ocular (Dcas, 62.7 ± 11.9) aromatase activity persisted after castration. The diabetic kidney also had increased levels of tissue estrogen (ND, 0.31 ± 0.01; D, 0.51 ± 0.11; Dcas, 0.45 ± 0.08) as well as estrogen receptor alpha protein expression (ND, 0.63 ± 0.09; D, 1.62 ± 0.28; Dcas, 1.38 ± 0.20). These data suggest that in male STZ-induced diabetic rats, tissues other than the testis may become sources of estradiol. In particular, the diabetic kidney appears to produce estradiol following castration, a state that is associated with a high degree or renal injury. Overall, our data provides evidence for the extra-testicular source of estradiol that in males, through an intracrine mechanism, may contribute to the development and/or progression of end-organ damage associated with diabetes.     

Inhibition of drug-induced Fas ligand transcription and apoptosis by Bcl-XL.

Fas/Fas ligand system triggers apoptosis in many cell types. Bcl-XL overexpresion antagonizes Fas/Fas ligand-mediated cell death. The mechanism by which Bcl-XL influences Fas-mediated cell death is unclear. We have found that microtubule-damaging drugs (e.g. Paclitaxel) induce apoptosis in a Fas/FasL-dependent manner. Inhibition of Fas/FasL pathway by anti-FasL antibody, mutant Fas or a dominant negative FADD blocks paclitaxel-induced apoptosis. Paclitaxel induced apoptosis through activation of both caspase-8 and caspase-3. Overexpression of Bcl-XL leads to inhibition of paclitaxel-induced FasL expression and apoptosis. Bcl-XL prevents the nuclear translocation of NFAT (nuclear factor of activated T lymphocytes) by inhibiting the activation of calcineurin, a calcium-dependent phosphatase that must dephosphorylate NFAT for it to move to the nucleus. The loop domain in Bcl-XL can suppress the anti-apoptotic function of Bcl-XL and may be a target for regulatory post-translational modifications. Upon phosphorylation, Bcl-XL loses its ability to bind with calcineurin. Without NFAT nuclear translocation, the FasL gene is not transcribed. Thus, paclitaxel and other drugs that disturb microtubule function kill cells, at least in part, through the induction of FasL, and Bcl-XL-mediated resistance to these agents is related to failure to induce FasL expression.     

Genetic characterization of mutants resistant to the antiauxin p-chlorophenoxyisobutyric acid reveals that AAR3, a gene encoding a DCN1-like protein, regulates responses to the synthetic auxin 2,4-dichlorophenoxyacetic acid in Arabidopsis roots

To isolate novel auxin-responsive mutants in Arabidopsis (Arabidopsis thaliana), we screened mutants for root growth resistance to a putative antiauxin, p-chlorophenoxyisobutyric acid (PCIB), which inhibits auxin action by interfering the upstream auxin-signaling events. Eleven PCIB-resistant mutants were obtained. Genetic mapping indicates that the mutations are located in at least five independent loci, including two known auxin-related loci, TRANSPORT INHIBITOR RESPONSE1 and Arabidopsis CULLIN1. antiauxin-resistant mutants (aars) aar3-1, aar4, and aar5 were also resistant to 2,4-dichlorophenoxyacetic acid as shown by a root growth assay. Positional cloning of aar3-1 revealed that the AAR3 gene encodes a protein with a domain of unknown function (DUF298), which has not previously been implicated in auxin signaling. The protein has a putative nuclear localization signal and shares homology with the DEFECTIVE IN CULLIN NEDDYLATION-1 protein through the DUF298 domain. The results also indicate that PCIB can facilitate the identification of factors involved in auxin or auxin-related signaling.     

Pathogen-specific CD8 T cell responses are directly inhibited by IL-10

Regulation of CD8 T cell expansion and contraction is essential for successful immune defense against intracellular pathogens. IL-10 is a regulatory cytokine that can restrict T cell responses by inhibiting APC functions. IL-10, however, can also have direct effects on T cells. Although blockade or genetic deletion of IL-10 enhances T cell-mediated resistance to infections, the extent to which IL-10 limits in vivo APC function or T cell activation/proliferation remains unknown. Herein, we demonstrate that primary and memory CD8 T cell responses following Listeria monocytogenes infection are enhanced by the absence of IL-10. Surface expression of the IL-10R is transiently up-regulated on CD8 T cells following activation, suggesting that activated T cells can respond to IL-10 directly. Consistent with this notion, CD8 T cells lacking IL-10R2 underwent greater expansion than wild-type T cells upon L. monocytogenes infection. The absence of IL-10R2 on APCs, in contrast, did not enhance T cell responses following infection. Our studies demonstrate that IL-10 produced during bacterial infection directly limits expansion of pathogen-specific CD8 T cells and reveal an extrinsic regulatory mechanism that modulates the magnitude of memory T cell responses.     

Photosynthetic response to water stress and changes in metabolites in <Emphasis Type="Italic">Jasminum sambac</Emphasis>

Gas exchange, chlorophyll (Chl) fluorescence, and contents of some metabolites in two genotypes of jasmine (Jasminum sambac), single petal (SP) and double petal (DP) one, were analyzed during dehydration and re-hydration. Water stress significantly decreased net photosynthetic rate, stomatal conductance, and maximum photochemical efficiency (F_v/F_m) in both jasmine genotypes, but increased minimum fluorescence (F₀) only in DP-jasmine. Water stress also decreased starch content, while increased contents of total soluble sugars and proline in leaves of both genotypes. SP-jasmine demonstrated higher drought tolerance as evidenced by maintaining higher gas exchange and photochemical efficiency and lower alteration of metabolites than DP-jasmine. Recovery analysis revealed that drought-induced injury in photosynthetic machinery in jasmine plants was reversible. DP-jasmine exhibited a slow recovery of drought-induced impairment in photosynthetic activity and associated metabolites, suggesting that this genotype had lower capacity to adapt to water limited condition. Higher yield stability of SP-than that of DP-jasmine under rain-fed condition finally confirmed higher drought tolerance of SP-jasmine.     

A thermostable cysteine protease precursor from a tropical plant contains an unusual C-terminal propeptide: cDNA cloning, sequence comparison and molecular modeling studies

We report here the cloning and characterization of the entire cDNA of a papain-like cysteine protease from a tropical flowering plant. The 1098-bp ORF of the cDNA codify a protease precursor having a signal peptide of 19 amino acids, a cathepsin-L like N-terminal proregion of 114 amino acids, a mature enzyme part of 208 amino acids and a C-terminal proregion of 24 amino acids. The derived amino acid sequence of the mature part tallies with the thermostable cysteine protease Ervatamin-C--as was aimed at. The C-terminal proregion of the protease has altogether a different sequence pattern not observed in other members of the family and it contains a negatively charged helical zone. The three-dimensional model of the precursor, based on the homology modeling and X-ray structure, shows that the extended peptide stretch region of the N-terminal propeptide, covering the interdomain cleft, contains protruding side chains of positively charged residues. This study also indicates that the negatively charged zone of C-terminal propeptide may interact with the positively charged zone of the N-terminal propeptide in a cooperative manner in the maturation process of this enzyme.     

Intermittent cyclic process for enhanced biological nutrient removal treating combined chemical laboratory wastewater

The aim of this work was to assess the efficacy for simultaneous enhanced removal of nitrogen and phosphorus including organics treating combined wastewater generated from a chemical laboratory using a bench-scale Intermittent Cyclic Process Bio-reactor (ICPBR). The performance efficacy indicated that the ICPBR system with solid retention time of 15 days achieved optimum efficiency with an overall removal of ammonia nitrogen (NH4-N), phosphorus (PO4-P), and chemical oxygen demand (COD) in the range, 83-92%, 74-93%, and 90-96%, respectively.     

Immunomodulatory effects of bovine colostrum in human peripheral blood mononuclear cells

Human and bovine colostrum (BC) contain a remarkable amount of bioactive substances, including antibodies towards many common pathogens of the intestinal and respiratory tract as well as growth factors, vitamins, cytokines and other proteic, lipidic and glucidic factors. In this study we investigated whether BC had any immunomodulatory effect on human peripheral blood mononuclear cells (PBMC) from healthy donors. To this aim we focused on the production of IL-12 and IFN-gamma, cytokines involved in the Th1 polarization required for a successful immune response towards intracellular pathogens, such as bacteria and viruses. BC induced a dose-dependent production of IL-12 by CD14+ monocytes, but was unable to induce IFN-gamma production. However, BC differentially affected stimuli-induced IFN-gamma production: it enhanced IFN-gamma in response to weak antigenic stimulation and it inhibited IFN-gamma in response to strong antigenic stimulation. These effects were not dose-dependent. We also measured PBMC proliferation, which was substantially unaffected by BC. Our data suggest that the Th1-promoting activity of BC could contribute, together with the antibodies, to the protective effect of BC on the offspring. BC could also represent an inexpensive therapeutic tool in prevention and treatment of several human microbial infections, including influenza.     

Air-breathing catfish, Clarias batrachus upregulates glutamine synthetase and carbamyl phosphate synthetase III during exposure to high external ammonia

We assessed the possible upregulation of glutamine synthetase (GS) and typical 'fish type' carbamyl phosphate synthetase III (CPS III) in detoxification of ammonia in different tissues of the walking catfish (Clarias batrachus) during exposure to 25 mM NH(4)Cl for 7 days. Exogenous ammonia led to an increase in ammonia and urea concentrations in different tissues. The results revealed the presence of relatively high levels of GS activity in the brain, liver and kidney, unexpectedly, also in the muscle, and even higher levels in the intestine and stomach. Exposure to high external ammonia (HEA) caused significant increase of activities of GS, CPS III and CPS I-like enzymes, accompanied with the upregulation of GS and CPS III enzyme proteins in different tissues. Exposure to HEA also led to a sharp rise of plasma cortisol level, suggesting being one of the primary causes of upregulation of GS and CPS III enzymes activity. Liver perfusion experiments further revealed that exposure to HEA enhances the capacity of trapping ammonia to glutamine and urea by the liver of walking catfish. These results suggest that the upregulation of GS and CPS III activity in walking catfish during exposure to HEA plays critical roles to ameliorate the toxic ammonia to glutamine, and also to urea via the induced ornithine-urea cycle possibly through the involvement of cortisol.     

Chimeric T helper-B cell peptides induce protective response against Japanese encephalitis virus in mice

Virus neutralizing MAb binding and T helper cell stimulating peptide epitopes from structural and non-structural proteins of Japanese encephalitis virus were delineated. It was observed that priming by T helper peptides potentiated neutralizing antibody response against JE virus. Immunization with chimeric T helper - B cell peptides could thus protect mice from lethal challenge with JE virus.