CRK12: A Key Player in Regulating the Phaseolus vulgaris-Rhizobium tropici Symbiotic Interaction.

Cysteine-rich receptor-like kinases (CRKs) are a type of receptor-like kinases (RLKs) that are important for pathogen resistance, extracellular reactive oxygen species (ROS) signaling, and programmed cell death in plants. In a previous study, we identified 46 CRK family members in the Phaseolus vulgaris genome and found that CRK12 was highly upregulated under root nodule symbiotic conditions. To better understand the role of CRK12 in the Phaseolus-Rhizobia symbiotic interaction, we functionally characterized this gene by overexpressing (CRK12-OE) and silencing (CRK12-RNAi) it in a P. vulgaris hairy root system. We found that the constitutive expression of CRK12 led to an increase in root hair length and the expression of root hair regulatory genes, while silencing the gene had the opposite effect. During symbiosis, CRK12-RNAi resulted in a significant reduction in nodule numbers, while CRK12-OE roots showed a dramatic increase in rhizobial infection threads and the number of nodules. Nodule cross sections revealed that silenced nodules had very few infected cells, while CRK12-OE nodules had enlarged infected cells, whose numbers had increased compared to controls. As expected, CRK12-RNAi negatively affected nitrogen fixation, while CRK12-OE nodules fixed 1.5 times more nitrogen than controls. Expression levels of genes involved in symbiosis and ROS signaling, as well as nitrogen export genes, supported the nodule phenotypes. Moreover, nodule senescence was prolonged in CRK12-overexpressing roots. Subcellular localization assays showed that the PvCRK12 protein localized to the plasma membrane, and the spatiotemporal expression patterns of the CRK12-promoter::GUS-GFP analysis revealed a symbiosis-specific expression of CRK12 during the early stages of rhizobial infection and in the development of nodules. Our findings suggest that CRK12, a membrane RLK, is a novel regulator of Phaseolus vulgaris-Rhizobium tropici symbiosis.

Resultados del primer registro de implante de cardiodesfibriladores y resincronizadores SAC (RENCARE) / Results of the First SAC Implantable Cardioverter-Defibrillator and Cardiac Resynchronization Therapy Registry (RENCARE)

RESUMEN Introducción: La prevención de la muerte súbita y el tratamiento de la insuficiencia cardíaca son temas de gran importancia. Para prevenir la muerte súbita y mejorar el pronóstico de la insuficiencia cardíaca se utilizan los cardiodesfibriladores y cardioresincronizadores. Objetivos: Evaluar la cantidad y tipo de dispositivos implantados en nuestro país, así como las características de los pacientes, las complicaciones agudas y las que se presentan en el seguimiento. Material y métodos: Se realizó un estudio observacional, prospectivo, multicéntrico en centros de salud con la capacidad de implantar cardiodesfibriladores y cardioresincronizadores. Se incluyeron pacientes a los que se les realizó implante de estos dispositivos desde enero del 2016 hasta enero de 2017, con un seguimiento de 12 meses. Resultados: Se incluyeron 249 pacientes (edad promedio de 64,8 ± 13,7 años, 73,9% de sexo masculino, 72,1% con Fey < 35%). La etiología subyacente de la miocardiopatía era isquémica en el 39,8%, dilatada 26,7% y chagásica en el 11,2% de los casos. El 58% de los implantes realizados fueron cardiodesfibriladores y el 39%, cardiodesfibriladores asociados con cardioresincronizadores. El 84% de los procedimientos fueron primoimplantes. La indicación más frecuente del implante fue por prevención primaria de muerte súbita (67,9%). La tasa de complicaciones menores fue del 4,4% y no se reportaron complicaciones mayores. Conclusiones: El siguiente registro evidenció una gran proporción de implantes en pacientes con cardiopatía isquémica, la indicación principal fue por prevención primaria de muerte súbita y la tasa de complicaciones fue similar a la reportada internacionalmente.

ABSTRACT Background: Prevention of sudden death and treatment of heart failure are very important topics. Implantable cardioverter-defibrillator and cardiac resynchronization devices are used to prevent sudden death and improve heart failure symptoms and prognosis. Objectives: The aim of this study was to evaluate the number, type of implanted devices, clinical characteristics of the patients and acute and follow-up complications. Methods: An observational, prospective, multicenter study was carried out in healthcare centers with the capacity to implant cardioverter-defibrillator and cardiac resynchronization devices. The study included all patients who underwent implantation of these devices from January 2016 to January 2017, with a 12-month follow-up. Results: A total of 249 patients (73.9% men) with mean age of 64.8±13.7 years, and 72.1% with ejection fraction <35%, were included in the study. The underlying cardiomyopathy etiology was ischemic in 39.8% of cases, dilated in 26.7% and chagasic in 11.2%. Fifty-eight percent of implants were implantable cardioverter-defibrillators and 39% were cardioverter-defibrillators associated with cardiac resynchronization devices. In 84% of cases, procedures were first implants. The most frequent indica-tion of implantation was for primary prevention of sudden death (67.9%). Minor complication rate was 4.4% and no major complications were reported. Conclusions: The present registry evidenced a large proportion of cardioverter-defibrillator and cardiac resynchronization implants in patients with ischemic heart disease. The main indication was for primary prevention of sudden death and the complication rate was similar to that reported internationally.

An immunoconjugated up-conversion nanocomplex for selective imaging and photodynamic therapy against HER2-positive breast cancer.

Photodynamic therapy represents a very attractive therapeutic tool considered to be effective, minimally invasive and minimally toxic. However, conventional photodynamic therapy actually has two main constraints: the limited penetration depth of visible light needed for its activation, and the lack of selectivity. Considering this, this work reports the synthesis and evaluation of a novel nanoconjugate for imaging and selective photodynamic therapy against HER2-positive breast cancer, a particularly aggressive form of the disease. It was demonstrated that upon 975 nm near infrared light exposure, the red emission of the NaYF4:Yb,Er up-conversion nanoparticles (UCNPs) can be used for optical imaging and simultaneously represent the source for the excitation of a covalently bound zinc tetracarboxyphenoxy phthalocyanine (ZnPc), a photosensitizer that in turn transfers energy to ground state molecular oxygen to produce cytotoxic singlet oxygen. The specificity of our nanoconjugates was achieved by immunoconjugation with Trastuzumab (Tras), a specific monoclonal antibody for selective detection and treatment of HER2-overexpressing malignant breast cancer cells. Selective tracking of SKBR-3 HER2-positive cells was verified by confocal microscopy analysis, and the photodynamic therapy effect was considerably improved when Trastuzumab was incorporated into the nanoconjugate, the UCNPs-ZnPc-Tras being practically inert in the absence of infrared light exposure but reducing the HER2-positive cell viability up to 21% upon 5 min of the irradiation. This theranostic nanoconjugate represents a valuable alternative for HER2-positive breast cancer imaging and selective photodynamic therapy.

Purinergic signalling and intercellular Ca2+ wave propagation in the organ of Corti.

Extracellular ATP is a key neuromodulator of visual and auditory sensory epithelia. In the rat cochlea, pharmacological dissection indicates that ATP, acting through a highly sensitive purinergic/IP(3)-mediated signaling pathway with (little or) no involvement of ryanodine receptors, is the principal paracrine mediator implicated in the propagation of calcium waves through supporting and epithelial cells. Measurement of sensitivity to UTP and other purinergic agonists implicate P2Y(2) and P2Y(4) as the main P2Y receptor isoforms involved in these responses. Ca2+ waves, elicited under highly reproducible conditions by carefully controlling dose (1 microM) and timing of focal agonist application (0.2s), extended over radial distance greater than 160 microm from the source, identical to those activated by damaging single outer hair cells. Altogether, these results indicate that intercellular calcium waves are a robust phenomenon that confers a significant ability for cell-cell communication in the mammalian cochlea. Further ongoing research will reveal the roles that such Ca2+ waves play in the inner ear.

A mechanism for sensing noise damage in the inner ear.

Our sense of hearing requires functional sensory hair cells. Throughout life those hair cells are subjected to various traumas, the most common being loud sound. The primary effect of acoustic trauma is manifested as damage to the delicate mechanosensory apparatus of the hair cell stereocilia. This may eventually lead to hair cell death and irreversible deafness. Little is known about the way in which noxious sound stimuli affect individual cellular components of the auditory sensory epithelium. However, studies in different types of cell cultures have shown that damage and mechanical stimulation can activate changes in intracellular free calcium concentration ([Ca(2+)](i)) and elicit intercellular Ca(2+) waves. Thus an attractive hypothesis is that changes in [Ca(2+)](i), propagating as a wave through support cells in the organ of Corti, may constitute a fundamental mechanism to signal the occurrence of hair cell damage. The mechanism we describe here exhibits nanomolar sensitivity to extracellular ATP, involves regenerative propagation of intercellular calcium waves due to ATP originating from hair cells, and depends on functional IP(3)-sensitive intracellular stores in support cells.