Biphasic regulation of mammary epithelial resistance by serotonin through activation of multiple pathways

Mammary gland homeostasis and the lactation-to-involution switch are regulated by serotonin (5-hydroxytryptamine (5-HT)). Mammary epithelial tight junctions are physiological targets of 5-HT, and their disruption marks an early stage of mammary gland involution. In these studies, we have identified signal transduction mechanism employed by 5-HT during regulation of mammary gland transepithelial resistance. Transepithelial electrical resistance and tight junction protein architecture were studied in cultures of MCF10A human mammary epithelial cells. Serotonin had biphasic effects on mammary epithelial resistance. At lower concentrations and earlier time points, 5-HT potentiated epithelial transmembrane resistance, whereas at higher concentrations and later time points, 5-HT decreased transepithelial electrical resistance and disrupted tight junctions. Both the early and delayed actions of 5-HT were mediated by the 5-HT7 receptor through activation of G(s)/cAMP. 5-HT induced the activities of both protein kinase A and p38 mitogen-activated protein kinase. Inhibition of p38 mitogen-activated protein kinase abrogated 5-HT-induced disruption of mammary epithelial tight junctions (the delayed effect). In contrast, inhibition of protein kinase A prevented the increased epithelial resistance in response to 5-HT (the transient effect). These studies imply an integrated set of mechanisms whereby transient, modest activation of 5-HT7 promotes tight junction integrity, and sustained 5-HT7 activation drives involution by disrupting tight junctions.     

Identification of operator sites within the upstream region of the putative mce2R gene from mycobacteria

Mycobacterium tuberculosis harbors four mce operons. Among them, mce2 operon is preceded by a FadR-like regulator mce2R (Rv0586). Here, we report the operator sites of the mce2R and its orthologs in other sequenced mycobacteria and non-mycobacterial species Nocardia farciana. All the identified DNA motifs illustrate the FadR subfamily specific nucleotide preference. Moreover, these motifs from the upstream region share sequence conservation, which is in agreement with the similarity of their DNA binding domain. Using electrophoretic mobility shift assay, we demonstrate that the predicted DNA motifs specifically interact with the recombinant Mce2R-Rv0586. Our present study has implications in the understanding of cis-regulatory elements and the auto-regulatory nature of the FadR subfamily of regulators.     

Pilomatricoma mimicking small round cell tumor on fine needle aspiration cytology: a case report

BACKGROUND: Pilomatricoma, a benign skin adnexal tumor, frequently leads to false positive diagnosis cytologically. We report a rapidly growing nodular swelling misdiagnosed as round cell tumor cytologically and found to be pilomatricoma histopathologically. CASE: A 32-year-old man presented with a rapidly growing, mobile nodule on his left arm for 4 months with fixed, shiny overlying skin. Fine needle aspiration cytology (FNAC) sample was cellular, showing round to ovoid cells dispersed or in clusters with occasionally rosette-like appearance. Cells displayed round, granular nuclei, single to multiple small nucleoli, absent to scant cytoplasm, a moderate amount of granular cytoplasm and apoptotic and mitotic figures in places. Nuclear moldings were encountered occasionally. Cytologically the diagnosis of blue round cell tumor was made. Histopathologic examination showed islands of basaloid cells with scant cytoplasm and shadow cells and occasional giant cells. The diagnosis was pilomatricoma bistopathologically. Rapidly growing, early lesions of pilomatricoma are predominantly composed of basaloid cells and mostly devoid of other diagnostic clues, leading to a false impression of malignancy. To avoid misdiagnosis, all skin-based nodules should undergo extensive cytologic sampling from diferent sites. Pilomatricoma should be considered in diferential diagnosis when primitive-appearing cells are aspirated, especially in rapidly growing early lesions.     

Affinity and intrinsic efficacy (IE) of 5'-carbamoyl adenosine analogues for the A1 adenosine receptor--efforts towards the discovery of a chronic ventricular rate control agent for the treatment of atrial fibrillation (AF)

The SAR for the affinity to the A(1) adenosine receptor and relative intrinsic efficacy (IE, [(35)S]-GTPgammaS binding) of a series of 5'-carbamate and 5'-thionocarbamate derivatives of tecadenoson is described. Based on this SAR, selected compounds were evaluated in guinea pig isolated hearts to determine whether they were partial or full agonists with respect to their negative dromotropism, an A(1) AdoR mediated effect. Progress towards obtaining a partial A(1) AdoR agonist to potentially control ventricular rate during atrial fibrillation has been made with the discovery of several potent partial A(1) AdoR agonists (compounds 13, 14, and 17).     

Exploring the onset of B12-based mutualisms using a recently evolved Chlamydomonas auxotroph and B12-producing bacteria

Cobalamin (vitamin B₁₂) is a cofactor for essential metabolic reactions in multiple eukaryotic taxa, including major primary producers such as algae, and yet only prokaryotes can produce it. Many bacteria can colonize the algal phycosphere, forming stable communities that gain preferential access to photosynthate and in return provide compounds such as B₁₂. Extended coexistence can then drive gene loss, leading to greater algal–bacterial interdependence. In this study, we investigate how a recently evolved B₁₂-dependent strain of Chlamydomonas reinhardtii, metE7, forms a mutualism with certain bacteria, including the rhizobium Mesorhizobium loti and even a strain of the gut bacterium E. coli engineered to produce cobalamin. Although metE7 was supported by B₁₂ producers, its growth in co-culture was slower than the B₁₂-independent wild-type, suggesting that high bacterial B₁₂ provision may be necessary to favour B₁₂ auxotrophs and their evolution. Moreover, we found that an E. coli strain that releases more B₁₂ makes a better mutualistic partner, and although this trait may be more costly in isolation, greater B₁₂ release provided an advantage in co-cultures. We hypothesize that, given the right conditions, bacteria that release more B₁₂ may be selected for, particularly if they form close interactions with B₁₂-dependent algae.     

Enhanced Remediation of Pentachlorophenol (PCP)-Contaminated Groundwater by Bioaugmentation with Known PCP-Degrading Bacteria

The objective of this study was to test whether bioaugmentation with known pentachlorophenol (PCP)-degrading bacteria (Sphingobium chlorophenolicum and Burkholderia cepacia) could enhance remediation of PCP-contaminated groundwater. Groundwater PCP concentrations were determined by US Environmental Protection Agency (EPA) method 3510C and gas chromatography. Gene expression for PCP-degrading enzymes: pentachlorophenol 4-monooxygenase (pcpB; S. chlorophenolicum) and chlorophenol 4-monooxygenase (TftD; B. cepacia) was determined by real-time polymerase chain reaction (RT-PCR) using gene-specific primers. Bioaugmented treatments with S. chlorophenolicum and B. cepacia showed 32% and 49% decrease (p < .05) whereas un-bioaugmented (indigenous) treatment did not show significant decrease (p > .05) in average PCP concentration, respectively, over 72 days. Decreased PCP levels correlated strongly (r = ?.82, p < .05) with increased PCP-tolerant bacteria in bioaugmented treatments, whereas no significant correlation was observed (r = ?.22, p > .05) in un-bioaugmented treatment. In addition, a decrease in PCP levels also correlated significantly with an increase in gene expression of PCP-degrading enzymes, pcpB (r = ?.77044) and TftD (r = ?.87905) (p < .05). PCP concentrations decreased and pcpB or TftD expressions were higher in bioaugmented treatments with S. chlorophenolicum (50%, 7-fold) or B. cepacia (67%, 10.7-fold), respectively, than indigenous treatment. Therefore, bioaugmentation with known PCP-degrading bacteria enhanced remediation of PCP-contaminated groundwater than indigenous bacteria alone. Results of this study may provide a more efficient and environmentally friendly technique for on-site remediation of PCP-contaminated groundwater.     

Enhanced ethanol fermentation of brewery wastewater using the genetically modified strain <Emphasis Type="Italic">E. coli </Emphasis>KO11

We have used liquid waste obtained from a beer brewery process to produce ethanol. To increase the productivity, genetically modified organism, Escherichia coli KO11, was used for ethanol fermentation. Yeast was also used to produce ethanol from the same feed stock, and the ethanol production rates and resulting concentrations of sugars and ethanol were compared with those of KO11. In the experiments, first the raw wastewater was directly fermented using two strains with no saccharification enzymes added. Then, commercial enzymes, α-amylase, pectinase, or a combination of both, were used for simultaneous saccharification and fermentation, and the results were compared with those of the no-enzyme experiments for KO11 and yeast. Under the given conditions with or without the enzymes, yeast produced ethanol more rapidly than E. coli KO11, but the final ethanol concentrations were almost the same. For both yeast and KO11, the enzymes were observed to enhance the ethanol yields by 61–84% as compared to the fermentation without enzymes. The combination of the two enzymes increased ethanol production the most for the both strains. The advantages of using KO11 were not demonstrated clearly as compared to the yeast fermentation results.     

Analysis of functional traits in Gracilaria dura (Rhodophyta: Gracilariacae) reveals variation in wild and farmed populations

Journal of Applied Phycology - Seaweeds, due to their diverse product profile, are in huge demand globally, and therefore, to meet feedstock requirements, farming is pivotal. Gracilaria dura from...