Presence and Function of Dopamine Transporter (DAT) in Stallion Sperm : Dopamine Modulates Sperm Motility and Acrosomal Integrity

Dopamine is a catecholamine with multiple physiological functions, playing a key role in nervous system; however its participation in reproductive processes and sperm physiology is controversial. High dopamine concentrations have been reported in different portions of the feminine and masculine reproductive tract, although the role fulfilled by this catecholamine in reproductive physiology is as yet unknown. We have previously shown that dopamine type 2 receptor is functional in boar sperm, suggesting that dopamine acts as a physiological modulator of sperm viability, capacitation and motility. In the present study, using immunodetection methods, we revealed the presence of several proteins important for the dopamine uptake and signalling in mammalian sperm, specifically monoamine transporters as dopamine (DAT), serotonin (SERT) and norepinephrine (NET) transporters in equine sperm. We also demonstrated for the first time in equine sperm a functional dopamine transporter using 4-[4-(Dimethylamino)styryl]-N-methylpyridinium iodide (ASP+ ), as substrate. In addition, we also showed that dopamine (1 mM) treatment in vitro, does not affect sperm viability but decreases total and progressive sperm motility. This effect is reversed by blocking the dopamine transporter with the selective inhibitor vanoxerine (GBR12909) and non-selective inhibitors of dopamine reuptake such as nomifensine and bupropion. The effect of dopamine in sperm physiology was evaluated and we demonstrated that acrosome integrity and thyrosine phosphorylation in equine sperm is significantly reduced at high concentrations of this catecholamine. In summary, our results revealed the presence of monoamine transporter DAT, NET and SERT in equine sperm, and that the dopamine uptake by DAT can regulate sperm function, specifically acrosomal integrity and sperm motility

Arsenic Nanoparticles Trigger Apoptosis via Anoikis Induction in OECM-1 Cells

Arsenic compounds have been used as therapeutic alternatives for several diseases including cancer. In the following work, we obtained arsenic nanoparticles (AsNPs) produced by an anaerobic bacterium from the Salar de Ascotán, in northern Chile, and evaluated their effects on the human oral squamous carcinoma cell line OECM-1. Resazurin reduction assays were carried out on these cells using 1–100 µM of AsNPs, finding a concentration-dependent reduction in cell viability that was not observed for the non-tumoral gastric mucosa-derived cell line GES-1. To establish if these effects were associated with apoptosis induction, markers like Bcl2, Bax, and cleaved caspase 3 were analyzed via Western blot, executor caspases 3/7 via luminometry, and DNA fragmentation was analyzed by TUNEL assay, using 100 µM cisplatin as a positive control. OECM-1 cells treated with AsNPs showed an induction of both extrinsic and intrinsic apoptotic pathways, which can be explained by a significant decrease in P-Akt/Akt and P-ERK/ERK relative protein ratios, and an increase in both PTEN and p53 mRNA levels and Bit-1 relative protein levels. These results suggest a prospective mechanism of action for AsNPs that involves a potential interaction with extracellular matrix (ECM) components that reduces cell attachment and subsequently triggers anoikis, an anchorage-dependent type of apoptosis

Identification and characterization of microRNAs in Phaseolus vulgaris by high-throughput sequencing

<p>Abstract</p> <p>Background</p> <p>MicroRNAs (miRNAs) are endogenously encoded small RNAs that post-transcriptionally regulate gene expression. MiRNAs play essential roles in almost all plant biological processes. Currently, few miRNAs have been identified in the model food legume <it>Phaseolus vulgaris </it>(common bean). Recent advances in next generation sequencing technologies have allowed the identification of conserved and novel miRNAs in many plant species. Here, we used Illumina's sequencing by synthesis (SBS) technology to identify and characterize the miRNA population of <it>Phaseolus vulgaris</it>.</p> <p>Results</p> <p>Small RNA libraries were generated from roots, flowers, leaves, and seedlings of <it>P. vulgaris</it>. Based on similarity to previously reported plant miRNAs,114 miRNAs belonging to 33 conserved miRNA families were identified. Stem-loop precursors and target gene sequences for several conserved common bean miRNAs were determined from publicly available databases. Less conserved miRNA families and species-specific common bean miRNA isoforms were also characterized. Moreover, novel miRNAs based on the small RNAs were found and their potential precursors were predicted. In addition, new target candidates for novel and conserved miRNAs were proposed. Finally, we studied organ-specific miRNA family expression levels through miRNA read frequencies.</p> <p>Conclusions</p> <p>This work represents the first massive-scale RNA sequencing study performed in <it>Phaseolus vulgaris </it>to identify and characterize its miRNA population. It significantly increases the number of miRNAs, precursors, and targets identified in this agronomically important species. The miRNA expression analysis provides a foundation for understanding common bean miRNA organ-specific expression patterns. The present study offers an expanded picture of <it>P. vulgaris </it>miRNAs in relation to those of other legumes.</p

Gene Silencing of \u3ci\u3eArgonaute5\u3c/i\u3e Negatively Affects the Establishment of the Legume-Rhizobia Symbiosis

The establishment of the symbiosis between legumes and nitrogen-fixing rhizobia is finely regulated at the transcriptional, posttranscriptional and posttranslational levels. Argonaute5 (AGO5), a protein involved in RNA silencing, can bind both viral RNAs and microRNAs to control plant-microbe interactions and plant physiology. For instance, AGO5 regulates the systemic resistance of Arabidopsis against Potato Virus X as well as the pigmentation of soybean (Glycine max) seeds. Here, we show that AGO5 is also playing a central role in legume nodulation based on its preferential expression in common bean (Phaseolus vulgaris) and soybean roots and nodules. We also report that the expression of AGO5 is induced after 1 h of inoculation with rhizobia. Down-regulation of AGO5 gene in P. vulgaris and G. max causes diminished root hair curling, reduces nodule formation and interferes with the induction of three critical symbiotic genes: Nuclear Factor Y-B (NF-YB), Nodule Inception (NIN) and Flotillin2 (FLOT2). Our findings provide evidence that the common bean and soybean AGO5 genes play an essential role in the establishment of the symbiosis with rhizobia

Quid: observatorio de medios

Informe organizado en cinco capítulos. En "El sistema de comunicación en Guadalajara" se incluyen trabajos sobre la transformación de algunos medios de comunicación, nuevos medios de comunicación en línea, periodismo religioso, la falta de institucionalidad en el Sistema Jalisciense de Radio y Televisión, y el sistema legal de radiodifusión y telecomunicaciones. En "Libertad de expresión en Jalisco", se presentan trabajos sobre la inseguridad laboral en los medios de comunicación, el desinformado cuarto de guerra del gobernador Aristóteles Sandoval, y sobre los periodistas escritores. En el apartado "Derecho a la información en Jalisco", se presenta un trabajo sobre la mucha administración y dosificada transparencia del Instituto de Trasparencia e Información Pública de Jalisco. El quinto apartado es una semblanza sobre “Rudy”, Rodolfo Rosales López, fotoperiodista tapatío. En el último apartado, “La investigación del observatorio de medios”, se presenta un trabajo sobre la cobertura en temas de medio ambiente y cambio climático en el periódico El Informador.ITESO, A.C

Intrinsically disordered protein biosensor tracks the physical-chemical effects of osmotic stress on cells.

Cell homeostasis is perturbed when dramatic shifts in the external environment cause the physical-chemical properties inside the cell to change. Experimental approaches for dynamically monitoring these intracellular effects are currently lacking. Here, we leverage the environmental sensitivity and structural plasticity of intrinsically disordered protein regions (IDRs) to develop a FRET biosensor capable of monitoring rapid intracellular changes caused by osmotic stress. The biosensor, named SED1, utilizes the Arabidopsis intrinsically disordered AtLEA4-5 protein expressed in plants under water deficit. Computational modeling and in vitro studies reveal that SED1 is highly sensitive to macromolecular crowding. SED1 exhibits large and near-linear osmolarity-dependent changes in FRET inside living bacteria, yeast, plant, and human cells, demonstrating the broad utility of this tool for studying water-associated stress. This study demonstrates the remarkable ability of IDRs to sense the cellular environment across the tree of life and provides a blueprint for their use as environmentally-responsive molecular tools

Q ITESO: Análisis Crítico de Medios

En esta séptima entrega de Q ITESO: Análisis Crítico de Medios se examina un 2014 colmado de acontecimientos sobre la reconfiguración de los medios de Jalisco y del país, y sus relaciones con el estado, los empresarios y el público. Destaca la aprobación de la Ley Federal de Telecomunicaciones y Radiocomunicación y los nuevos equilibrios de poder que esto supone. También, se analizan las alianzas de algunos diarios nacionales y del estado con medios extranjeros, para compensar algunas carencias y ampliar su oferta editorial e informativa. Otras cuestiones no menos relevantes tienen que ver con la libertad de expresión y la inseguridad laboral en la que viven muchos trabajadores de los medios de comunicación jaliscienses, sobre todo los impresos, y el caso emblemático del llamado “cuarto de guerra” al servicio del gobernador del estado, Aristóteles Sandoval, para espiar -y en ocasiones hasta coaccionar- a directivos y reporteros de medios para atenuar la crítica al gobierno. El derecho a la información, la transparencia, la situación de los nuevos medios en línea, los periodistas que publican libros, el cambio climático y los periodistas que ya no están con nosotros merecen también una mirada atenta en este informe.ITESO, A.C

Cryo-EM structure of the human Kv3.1 channel reveals gating control by the cytoplasmic T1 domain

Kv3 channels have distinctive gating kinetics tailored for rapid repolarization in fast-spiking neurons. Malfunction of this process due to genetic variants in the KCNC1 gene causes severe epileptic disorders, yet the structural determinants for the unusual gating properties remain elusive. Here, we present cryo-electron microscopy structures of the human Kv3.1a channel, revealing a unique arrangement of the cytoplasmic tetramerization domain T1 which facilitates interactions with C-terminal axonal targeting motif and key components of the gating machinery. Additional interactions between S1/S2 linker and turret domain strengthen the interface between voltage sensor and pore domain. Supported by molecular dynamics simulations, electrophysiological and mutational analyses, we identify several residues in the S4/S5 linker which influence the gating kinetics and an electrostatic interaction between acidic residues in α6 of T1 and R449 in the pore-flanking S6T helices. These findings provide insights into gating control and disease mechanisms and may guide strategies for the design of pharmaceutical drugs targeting Kv3 channels

Late Embryogenesis Abundant (LEA) proteins in legumes

Plants are exposed to different external conditions that affect growth, development, and productivity. Water deficit is one of these adverse conditions caused by drought, salinity, and extreme temperatures. Plants have developed different responses to prevent, ameliorate or repair the damage inflicted by these stressful environments. One of these responses is the activation of a set of genes encoding a group of hydrophilic proteins that typically accumulate to high levels during seed dehydration, at the last stage of embryogenesis, hence named Late Embryogenesis Abundant (LEA) proteins. LEA proteins also accumulate in response to water limitation in vegetative tissues, and have been classified in seven groups based on their amino acid sequence similarity and on the presence of distinctive conserved motifs. These proteins are widely distributed in the plant kingdom, from ferns to angiosperms, suggesting a relevant role in the plant response to this unfavorable environmental condition. In this review, we analyzed the LEA proteins from those legumes whose complete genomes have been sequenced such as Phaseolus vulgaris, Glycine max, Medicago truncatula, Lotus japonicus, Cajanus cajan and Cicer arietinum. Considering their distinctive motifs, LEA proteins from the different groups were identified, and their sequence analysis allowed the recognition of novel legume specific motifs. Moreover, we compile their transcript accumulation patterns based on publicly available data. In spite of the limited information on these proteins in legumes, the analysis and data compiled here confirms the high correlation between their accumulation and water deficit, reinforcing their functional relevance under this detrimental conditions