26 research outputs found

    Effects and consequences of small-scale cage culture technology adoption in Kerala

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    Small-scale fish farming is critical in ensuring food security and employment in many developing countries. Small-scale cage culture for Etroplus suratensis was introduced in the state by the Department of Fisheries, Government of Kerala with the same objectives. The demand for the species has shown considerable increase in the recent years and f m gate prices are as high as Rs 450kg in the peak season. Elevation to the status of State Fish has also helped the culture of the species in attracting the attention of policy makers leading to promotion of its culture. Cage culture in brackishwater bodies, a relatively new technology to the State, was popularized among the tsunami affected fishermen along with extension and technical support. The implementation of cage culture was promoted through the Brackishwater Fish Farmers' Development Agency (BFFDAs) and Agency for Development ofAquaculture Kerala (ADAK), two subsidiaries of the Department of Fisheries, Government of Kerala. The present study probes the effects and consequences of cage culture technology adoption among farmers based on primary data collected from sample respondents during the initial year of culture

    Inhibition of L-Type Ca 2+ Channels by TRPC1-STIM1 Complex Is Essential for the Protection of Dopaminergic Neurons

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    Loss of dopaminergic (DA) neurons leads to Parkinson’s disease; however, the mechanism(s) for the vulnerability of DA neurons is(are) not fully understood. We demonstrate that TRPC1 regulates the L-type Ca2 channel that contributes to the rhythmic activity of adult DA neurons in the substantia nigra region. Store depletion that activates TRPC1, via STIM1, inhibits the frequency and amplitude of the rhythmic activity in DA neurons of wild-type, but not in TRPC1/, mice. Similarly, TRPC1/ substantia nigra neurons showed increased L-type Ca2 currents, decreased stimulation-dependent STIM1-Cav1.3 interaction, and decreased DA neurons. L-type Ca2 currents and the open channel probability of Cav1.3 channels were also reduced upon TRPC1 activation, whereas increased Cav1.3 currents were observed upon STIM1 or TRPC1 silencing. Increased interaction between Cav1.3-TRPC1-STIM1 was observed upon store depletion and the loss of either TRPC1 or STIM1 led to DA cell death, which was prevented by inhibiting L-type Ca2 channels. Neurotoxins that mimic Parkinson’s disease increased Cav1.3 function, decreased TRPC1 expression, inhibited Tg-mediated STIM1-Cav1.3 interaction, and induced caspase activation. Importantly, restoration of TRPC1 expression not only inhibited Cav1.3 function but increased cell survival. Together, we provide evidence that TRPC1 suppresses Cav1.3 activity by providing an STIM1-based scaffold, which is essential for DA neuron survival.Fil: Sun, Yuyang. University of North Dakota; Estados UnidosFil: Zhang, Haopeng. University of North Dakota; Estados UnidosFil: Selvaraj, Senthil. University of North Dakota; Estados UnidosFil: Sukumaran, Pramod. University of North Dakota; Estados UnidosFil: Lei, Saobo. University of North Dakota; Estados UnidosFil: Birnbaumer, Lutz. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. National Institutes of Environmental Health Sciences; Estados UnidosFil: Singh, Brij B.. University of North Dakota; Estados Unido

    Ca2+ Entry via TRPC1 is Essential for Cellular Differentiation and Modulates Secretion via the SNARE Complex

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    Adipocyte functionality, including adipocyte differentiation and adipokine secretion, is essential in obesity-associated metabolic syndrome. Here, we provide evidence that Ca2+ influx in primary adipocytes, especially upon store-depletion, plays an important role in adipocyte differentiation, functionality, and subsequently metabolic regulation. The endogenous Ca2+ entry channel in both subcutaneous and visceral adipocytes was dependent on TRPC1-STIM1 and blocking Ca2+ entry with SKF-96365 or TRPC1-/- derived adipocytes inhibited adipocyte differentiation. Additionally, TRPC1-/- mice have decreased organ weight, but increased adipose deposition and reduced serum adiponectin and leptin concentrations, without affecting total adipokine expression. Mechanistically, TRPC1- mediated Ca2+ entry regulated SNARE complex formation and agonist –mediated secretion of adipokine loaded vesicles was inhibited in TRPC1-/- adipose. These results suggest an unequivocal role of TRPC1 in adipocytes differentiation and adiponectin secretion, and loss of TRPC1 disturbs metabolic homeostasis

    Role of the canonical transient receptor potential channel 2 (TRPC2) in thyroid cell function

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    Kalciumjonen reglerar flera processer i celler såsom transkribering av gener, celldelning, cellernas rörlighet och celldöd. Därför har cellerna utvecklat många mekanismer för att reglera den intracellulära kalciumkoncentrationen. Kalciumkanaler spelar en viktig roll i denna regleringsprocess. TRPC-kanalerna (eng. canonical transient receptor potential) är en familj av jonkanaler med sju medlemmar (TRPC1-7) vars regleringsmekanismer och fysiologiska roller är varierande. TRPC2-kanalens fysiologiska signifikans, samt hur kanalen regleras, är dåligt karakteriserad. För första gången, rapporterar vi närvaron av TRPC2 kanalen i råttans sköldkörtelceller samt primära sköldkörtelceller från råtta. Hos gnagare har TRPC2 antagits vara exklusivt uttryckt i det vomeronasala organet. För att undersöka den fysiologiska betydelsen av kanalen, har vi utvecklat stabila celler med nedreglerat TRPC2 (shTRPC2) m.h.a. shRNA-teknik. Nedreglering av TRPC2 resulterade i stora skillnader i flera viktiga cellulära funktioner och i regleringen av sköldkörtelcellernas cellsignalering. Nedreglering av TRPC2 orsakade minskad agonist-beroende frigivning av kalcium från det endoplasmatiska nätverket, samt minskat agonist-beroende inflöde av extracellulärt kalcium, men ökade det basala kalciuminflödet. Uttrycket av PKCβ1 och PKCδ, SERCA-aktiviteten och kalciumhalten i det endoplasmatiska nätverket minskade i shTRPC2 celler. Kommunikation mellan kalcium- och cAMP-signalering påvisades vara TRPC2-beroende, vilket visades reglera uttrycket av TSH-receptorn. Vi undersökte också betydelsen av TRPC2 kanalen i reglering av sköldkörtelcellers proliferation, migration, vidhäftning och invasion; processer som alla var dämpade i shTRPC2 celler. Samamnfattningsvis påvisade dessa resultat en ny och viktig fysiologisk betydelse för TRPC2 kanalerna.

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    Complexation of c6-ceramide with cholesteryl phosphocholine - a potent solvent-free ceramide delivery formulation for cells in culture.

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    Ceramides are potent bioactive molecules in cells. However, they are very hydrophobic molecules, and difficult to deliver efficiently to cells. We have made fluid bilayers from a short-chain D-erythro-ceramide (C6-Cer) and cholesteryl phosphocholine (CholPC), and have used this as a formulation to deliver ceramide to cells. C6-Cer complexed with CholPC led to much larger biological effects in cultured cells (rat thyroid FRTL-5 and human HeLa cells in culture) compared to C6-Cer dissolved in dimethyl sulfoxide (DMSO). Inhibition of cell proliferation and induction of apoptosis was significantly more efficient by C6-Cer/CholPC compared to C6-Cer dissolved in DMSO. C6-Cer/CholPC also permeated cell membranes and caused mitochondrial Ca(2+) influx more efficiently than C6-Cer in DMSO. Even though CholPC was taken up by cells to some extent (from C6-Cer/CholPC bilayers), and was partially hydrolyzed to free cholesterol (about 9%), none of the antiproliferative effects were due to CholPC or excess cholesterol. The ceramide effect was not limited to D-erythro-C6-Cer, since L-erythro-C6-Cer and D-erythro-C6-dihydroCer also inhibited cell priolifereation and affected Ca(2+) homeostasis. We conclude that C6-Cer complexed to CholPC increased the bioavailability of the short-chain ceramide for cells, and potentiated its effects in comparison to solvent-dissolved C6-Cer. This new ceramide formulation appears to be superior to previous solvent delivery approaches, and may even be useful with longer-chain ceramides

    Calcium Signaling Regulates Autophagy and Apoptosis

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    Calcium (Ca2+) functions as a second messenger that is critical in regulating fundamental physiological functions such as cell growth/development, cell survival, neuronal development and/or the maintenance of cellular functions. The coordination among various proteins/pumps/Ca2+ channels and Ca2+ storage in various organelles is critical in maintaining cytosolic Ca2+ levels that provide the spatial resolution needed for cellular homeostasis. An important regulatory aspect of Ca2+ homeostasis is a store operated Ca2+ entry (SOCE) mechanism that is activated by the depletion of Ca2+ from internal ER stores and has gained much attention for influencing functions in both excitable and non-excitable cells. Ca2+ has been shown to regulate opposing functions such as autophagy, that promote cell survival; on the other hand, Ca2+ also regulates programmed cell death processes such as apoptosis. The functional significance of the TRP/Orai channels has been elaborately studied; however, information on how they can modulate opposing functions and modulate function in excitable and non-excitable cells is limited. Importantly, perturbations in SOCE have been implicated in a spectrum of pathological neurodegenerative conditions. The critical role of autophagy machinery in the pathogenesis of neurodegenerative diseases such as Alzheimer’s, Parkinson’s, and Huntington’s diseases, would presumably unveil avenues for plausible therapeutic interventions for these diseases. We thus review the role of SOCE-regulated Ca2+ signaling in modulating these diverse functions in stem cell, immune regulation and neuromodulation

    Direct Outreach in Bars and Clubs to Enroll Cigarette Smokers in Mobile Cessation Services: Exploratory Study

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    BackgroundCigarette smoking and alcohol use are well known to be concomitant behaviors, but there is a lack of studies related to recruitment of smokers for mobile cessation services at places where alcohol is consumed, such as bars and clubs. Adapting recruitment strategies to expand the reach of cessation programs to where tobacco users are located may help decrease the health-equity gap in tobacco control by improving reach and enrollment of underserved smokers residing in low-income and rural areas who are not reached by traditional cessation services. ObjectiveThe purpose of this exploratory study was to assess the feasibility of direct outreach in bars, clubs, and restaurants to recruit smokers to Quitxt, our mobile smoking cessation service. Quitxt is delivered through SMS text messaging or Facebook Messenger. MethodsWe collaborated with an advertising agency to conduct in-person recruitment of young adult smokers aged 18-29 years, focusing on urban and rural Spanish-speaking Latino participants, as well as English-speaking rural White and African American participants. Street team members were recruited and trained in a 4-hour session, including a brief introduction to the public health impacts of cigarette smoking and the aims of the project. The street teams made direct, face-to-face contact with smokers in and near smoking areas at 25 bars, clubs, and other venues frequented by young smokers in urban San Antonio and nearby rural areas. ResultsThe 3923 interactions by the street teams produced 335 (8.5%) program enrollments. Most participants were English speakers with a mean age of 29.2 (SD 10.6) years and smoked a mean of 8.5 (SD 6.2) cigarettes per day. Among users who responded to questions on gender and ethnicity, 66% (70/106) were women and 56% (60/107) were Hispanic/Latino. Among users ready to make a quit attempt, 22% (17/77) reported 1 tobacco-free day and 16% (10/62) reported maintaining cessation to achieve 1 week without smoking. The response rate to later follow-up questions was low. ConclusionsDirect outreach in bars and clubs is a useful method for connecting young adult cigarette smokers with mobile cessation services. However, further research is needed to learn more about how mobile services can influence long-term smoking cessation among those recruited through direct outreach, as well as to test the use of incentives in obtaining more useful response rates

    C6-Cer/CholPC and C6-dihydroCer reduce mitochondrial calcium uptake.

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    <p>HeLa cells were preincubated for 180 min with 0.05 mM C6-Cer/CholPC or C6-Cer/DMSO (panels A and B), and changes in intracellular Ca<sup>2+</sup> levels were measured using mtAEQ. DMSO was added to control cells. Panel A shows kinetics of changes in mitochondrial Ca<sup>2+</sup> after challenge with histamine. In panel B, the change in Ca<sup>2+</sup> response was quantitated. The cells were challenged with 100 µM histamine as indicated by the arrow. Panel C shows kinetics of the Ca<sup>2+</sup> response after180 min exposure of cells to C6-dihydroCer. Traces (panel A and C) are averages of 3 measurements, each representing the average luminescence from a cell population of 150 000–200 000 cells. In panel B, the bar shows the average change in [Ca<sup>2+</sup>]<sub>mito</sub> during histamine-induced Ca<sup>2+</sup> release (± SEM, n = 3). The data were analyzed using one-way Anova and Bonferroni’s multiple comparison test (***p<0.001 compared with DMSO; ¤¤¤p<0.001 compared with C6-Cer).</p
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