Linking Induction and Transrepression of PPARβ/δ with Cellular Function

The copyrights of all papers published in this journal are retained by the respective authors as per the 'Creative Commons Attribution License' (http://creativecommons.org/licenses/by/3.0/).Peroxisome proliferator activated receptors (PPARs) are ligand-activated transcription factors and members of the nuclear hormone receptor superfamily. PPARβ/δ is ubiquitously expressed and has a central role in homeostasis, and has been suggested as a therapeutic target for a number of metabolic and cardiovascular disorders. This important nuclear receptor controls transcription under different modes of molecular activity which directly control the cellular function and fate of tissues. This complex activity of induction and transrepression of gene expression (with and without exogenous ligands) is poorly understood and yet understanding this molecular control through novel drug development would led to control over a key molecular switch in all cells. This review outlines the main molecular mechanisms of PPARβ/δ, and links the modes of activity to the signalling pathways in inflammation, proliferation and senescence, with the goal to understand how this will translate into novel drug design to control the PPARβ/δ molecular switch.Peer reviewe

The Effects of PPARβ/δ Ligands on Lung Inflammation and Vascular Reactivity

The peroxisome proliferator activated receptor beta/delta (PPARβ/δ) is a transcription factor ubiquitously expressed in cells, although more highly active in skeletal muscle, arteries and endothelium. Signalling via PPARβ/δ is involved in lipid metabolism, glucose metabolism, insulin sensitivity, inflammation, and cell proliferation and therefore it is emerging as a therapeutic target for the treatment of disorders associated with metabolic syndrome or diabetes. However, there are great discrepancies in the literature about the role of PPARβ/δ and scientists describe both anti- and pro-effects on inflammation, cell migration and cell proliferation after ligand-activation of PPARβ/δ. Understanding the PPARβ/δ mode of action is of great interest and may provide new molecular mechanisms for treating a variety of inflammation-related diseases. This thesis aims to expand the knowledge on PPARβ/δ to better understand its mechanism of action at genomic and non-genomic level, which might give some clues for new therapeutic drug developments targeting PPARβ/δ. Methods: Pharmacological techniques including organ bath and myography were used for the study of the non-genomic effects of PPARβ/δ on vascular tone, comparing aorta and mesenteric arteries as a model of systemic and resistance vasculature respectively from healthy and streptozotocin (STZ)-induced diabetic rats. Molecular biology techniques including Griess assay, ELISA and qRT-PCR were used for the study of the regulation of lung inflammation by PPARβ/δ, focusing on the PPARβ/δ molecular switch between induction and trans-repression, two different pathways of gene regulation. Computational methods such as docking were used for the study of the PPARβ/δ binding pocket and how PPARβ/δ is activated/repressed after ligand binding as well as the possibility of accommodating more than one ligand simultaneously into the binding pocket. Results: In large STZ-diabetic systemic aorta arteries, PPARβ/δ inhibits the contraction through the PI3K/Akt/eNOS pathway. GW0742, a PPARβ/δ agonist, improves vasodilation through the RhoA/ROCK pathway in Naïve aorta and through potassium channels in STZ-diabetic aorta. In resistance arteries such as mesenteric arteries, PPARβ/δ inhibits the contraction through the PI3K/Akt/eNOS pathway in Naïve and possibly STZ-diabetic tissues. In contrast, GW0742 inhibits the RhoA/ROCK pathway on STZ-diabetic mesentery arteries and regulates the potassium channels in Naïve mesenteric arteries in a PPARβ/δ independent manner. In the model of lung inflammation used, the presence of agonist (GW0742 or L-165041) and antagonist (GSK3787 or GSK0660) at same time has anti-inflammatory effects and switches the PPARβ/δ mode of action from induction to trans-repression, therefore it was concluded that, at least in this model, the PPARβ/δ induction mode of action is pro-inflammatory and the trans-repression anti-inflammatory. PPARβ/δ agonists and antagonists bind differently to the PPARβ/δ receptor pocket. PPARβ/δ agonists form polar interactions with the residues His287, His413 and Tyr437 whilst PPARβ/δ antagonists form polar interactions with the residues Thr252 and Asn307. Further, our modelling indicates favourable binding energies and the feasibility of two ligands binding at same time into the PPARβ/δ binding pocket. Conclusion: A multidisciplinary approach was designed for the study of PPARβ/δ and provided novel information about its functioning both at genomic and non-genomic level. The findings of this thesis can help the drug discovery industry for a better prediction of the modelling behaviour of new PPARβ/δ drugs and can support the rationale for developing new treatments targeting PPARβ/δ for hypertension and/or cardiovascular complications

Actualización del mapa de vegetación del afloramiento ultramáfico de Sierra Bermeja (Málaga, España)

El objetivo de este trabajo consiste en actualizar el mapa de vegetación del afloramiento ultramáfico de Sierra Bermeja (Málaga, España), reduciendo a unidades básicas de vegetación los polígonos fotointerpretados y deinidos de modo isionómico, para ser nominadas bajo aspectos itosociológicos, que luego puedan ser transcritas a hábitats de la Directiva 92/43UE. Se ha puesto especial énfasis en la diferenciación de los polígonos correspondientes a la zonopotencialidad de Pinus pinaster versus Abies pinsapo. La metodología utilizada se ha basado en el uso de SIG para fusionar polígonos homogéneos utilizando para ello la tabla de atributos con el campo de deinición de la vegetación de cada polígono. Se han identiicado 52 tipos de vegetación con sus correspondientes áreas, destacando el tipo de matorral-jaguarzal serpentinícola como el más abundante (56,4% del área total), mientras que los bosques de Abies pinsapo se reducen a solo 53 Ha. Son destacables los matorrales tipo jarales serpentinícolas (24,2% del areal total), por su relación con el dinamismo post-fuego. Este tipo de datos junto con otros tipos de unidades, incluidas zonas antropizadas, son de importancia para una ordenación y gestión de un futuro parque nacional en la zona.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Proyecto I+D+i ULTRAFORESTS (CSO2013-47713-P): “Reconstrucción geohistórica de la vegetación arbórea sobre sustratos ultramáicos mediterráneos

Field Trials for the Empirical Characterization of the Low Voltage Grid Access Impedance From 35 kHz to 500 kHz

The access impedance of low-voltage (LV) power networks is a major factor related to the performance of the narrow-band power line communications (NB-PLCs) and, in a wider sense, to electromagnetic compatibility (EMC) performance. Up to date, there is still a lack of knowledge about the frequency-dependent access impedance for frequencies above 9 kHz and up to 500 kHz, which is the band where the NB-PLC operates. The access impedance affects the transmission of the NB-PLC signal, and it determines the propagation of the non-intentional emissions that may disturb other electrical devices, including malfunctioning or reduced lifetime of equipment. This paper presents the results of field measurements of the LV access impedance up to 500 kHz in different scenarios, with measurement locations close to end users and near transformers. The results provide useful information to analyze the characteristics of the LV access impedance, including variation with frequency, ranges of values for different frequency bands, and analysis of specific phenomena. Moreover, the results reveal a diverse frequency-dependent behavior of the access impedance in different scenarios, depending on the grid topology, the number of end users (that is, number and type of connected loads), and the type of transformation center. Overall, the results of this paper offer a better understanding of the transmission of NB-PLC signals and EMC-related phenomena.The authors would like to thank Iberdrola for the availability and the collaboration of authorized staff for carrying out the field trials

Aplicación de la ecomorfología y la fenomorfología a la conservación de serpentinófitos en el sur de la Península Íbérica (Sierra Bermeja, Málaga)

Sierra Bermeja de Málaga es un macizo montañoso con una gran singularidad litológica y edáfica. Está compuesta principalmente por peridotitas, que son rocas ultramáficas intrusivas con una composición muy característica (olivinos, piroxenos, metales pesados) que, por su lento proceso de edafización, han dirigido la evolución de determinados taxones de la flora regional. A estos endemismos estrictos se les conoce como serpentinófitos (Pérez Latorre et al. 2013). La flora serpentinófita de los afloramientos peridotíticos malagueños, ha sido estudiada por Pérez Latorre et al. (2013) y muchos de los serpentinófitos están protegidos por la ley o amenazados. A pesar de la importancia de conocer los caracteres ecomorfológicos (tipos funcionales que representan adaptaciones al medio) (Orshan, 1986) y la fenomorfología (variación estacional de los órganos en respuesta a variaciones en el medio y estudio de las fases fenológicas) (Orshan, 1989) para trabajos de biología de la conservación, hasta el momento este tipo de estudios no se han aplicado para el caso de los serpentinófitos. En esta comunicación, como representación de la flora serpentinófita, se presentarán los resultados obtenidos sobre los caracteres ecomorfológicos de Bupleurum acutifolium (VU: Lista Roja estatal y andaluza) y sobre la fenomorfología de Armeria colorata (EN: Lista Roja estatal y andaluza y legislación andaluza). Las adaptaciones ecomorfológicas proporcionan información sobre la resistencia de los taxones al fuego y al pastoreo, y sobre su resistencia potencial a la sequía o a soportar un dosel arbóreo. El conocimiento de las fases fenológicas (vegetativas y reproductivas) puede verse como un carácter adaptativo fundamental y muy especialmente en un clima mediterráneo, y además con las peculiaridades edáficas del territorio en cuestión. Ambos tipos de estudios, proporcionarán valiosos datos para la comprensión del funcionamiento de estos taxones, que están protegidos por la ley e incluidos en las listas y libros rojos. Es por ello que pensamos que esta información eco y fenomorfológica debería aparecer en los Planes de conservación y recuperación de especies amenazadas. ORSHAN, G. (1986). “Plant form as describing vegetation and expressing adaptation to environment”. Annali di Botanica, 44, 7-38. ORSHAN, G. (ed.) (1989). Plant phenomorphological studies in Mediterranean type ecosystems. Dodrecht: Kluwer Academic Publishers. PÉREZ-LATORRE, A. V., N. HIDALGO-TRIANA & B. CABEZUDO (2013). Composition, ecology and conservation of the south-Iberian serpentine flora in the context of the Mediterranean basin. Anales del Jardín Botánico de Madrid 70(1): 62-71. doi: 10.3989/ajbm. 2334.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

The PPARβ/δ agonist GW0742 prevents LPS-induced nitrite production in rat parenchyma but not in aorta or pulmonary arteries

Peroxisome Proliferator activated receptors (PPARs) are therapeutic targets in the treatment of inflammatory lung disease. The PPARβ/δ agonist GW0742 has potent anti-inflammatory effects in the vasculature (Kapoor et al 2010) which has been linked to a decrease in the production of iNOS in the heart (Kapoor 2010) and activation of Akt-eNOS in arteries (Quintela et al 2014). Here in this study we measured changes in LPS induced NO production in rat arteries and lung parenchyma. Male Wistar (300-350g) rats were killed by CO2 followed by cervical dislocation, and the aorta, conductance and resistance pulmonary arteries and lung parenchyma were dissected under sterile conditions, and placed into 24 well plates. Following incubation with 1µg/ml LPS with/without 10-7M GW0742 tissues were incubated for 24 hours, and Griess assay performed to measure nitrite production (a measure of NO release).Our results show that LPS induces a significant increase in NO production from arteries and parenchyma (figure 1). Incubation with GW0742 alone has no effect on basal nitrite levels and does not have an effect on LPS-induced NO production in all types of arteries. In comparison, GW0742 significantly reduces LPS induced NO release in lung parenchyma comparable to inhibition by 10-4M L-NAME and 10-5M 1400W.Figure 1. 2mm rings of aorta, conductance pulmonary artery (CPS), resistance pulmonary artery (RPA) and 1mm2 lung parenchyma strips (lung) were incubated with 1ug/ml LPS ± 10-7M GW0742 in DMEM for 24 hours. Supernatant was removed and Griess assay performed to measure nitrite. Data is expressed as mean ± SEM; * and f denote p<0.05 by one way ANOVA and Tukey’s post-hoc test, respectively.In summary, incubation for 24 hours with 10-7M GW0742 significantly reduced LPS induced nitrite production in lung parenchyma but not in aorta or pulmonary arteries (conductance and resistance). These data suggest that the effects of PPARβ/δ agonists are tissue specific and might support their use as anti-inflammatory agents in lung disease. Kapoor et al Am J Respir Crit Care Med (2010):182; 1506–1515Quintela et al British Journal of Pharmacology (2014):171; 3089–3102Peer reviewe

Calificación de instalación, operación y desempeño de una estufa de secado de lecho estático empleada en los procesos de secado del granulado de formas farmacéuticas sólidas

El objetivo del presente trabajo fue la calificación del equipo empleado en los procesos de secado del granulado de formas farmacéuticas sólidas, donde se dan operaciones de transferencia de calor y masa. La calificación consistió en la realización del protocolo de calificación de instalación operación y desempeño para la estufa de secado de lecho estático. En referencia a la calificación de instalación, se verificó la documentación de la instalación de los distintos componentes del equipo, así como del sistema eléctrico. Para la calificación de operación, se verificó el funcionamiento de los diferentes dispositivos, la documentación de los procedimientos de operación, mantenimiento, la verificación de alarmas, y el desarrollo de pruebas para la comprobación de su funcionamiento. Respecto a la calificación de desempeño, se diseñó una metodología para la evaluación de las variables de control del equipo, mediante la evaluación de la distribución de calor en la estufa con carga y la determinación del porcentaje de humedad del granulado. De acuerdo a la información obtenida, en el protocolo de calificación, se elaboró un reporte final de calificación del equipo, concluyendo que la estufa de secado de lecho estático está calificada.Tesi

Co-Incubation with PPARβ/δ Agonists and Antagonists Modeled Using Computational Chemistry: Effect on LPS Induced Inflammatory Markers in Pulmonary Artery

© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/)Peroxisome proliferator activated receptor beta/delta (PPARβ/δ) is a nuclear receptor ubiquitously expressed in cells, whose signaling controls inflammation. There are large discrepan-cies in understanding the complex role of PPARβ/δ in disease, having both anti‐ and pro‐effects on inflammation. After ligand activation, PPARβ/δ regulates genes by two different mechanisms; induction and transrepression, the effects of which are difficult to differentiate directly. We studied the PPARβ/δ‐regulation of lipopolysaccharide (LPS) induced inflammation (indicated by release of nitrite and IL‐6) of rat pulmonary artery, using different combinations of agonists (GW0742 or L−165402) and antagonists (GSK3787 or GSK0660). LPS induced release of NO and IL‐6 is not significantly reduced by incubation with PPARβ/δ ligands (either agonist or antagonist), however, co-incubation with an agonist and antagonist significantly reduces LPS‐induced nitrite production and Nos2 mRNA expression. In contrast, incubation with LPS and PPARβ/δ agonists leads to a significant increase in Pdk−4 and Angptl−4 mRNA expression, which is significantly decreased in the presence of PPARβ/δ antagonists. Docking using computational chemistry methods indicates that PPARβ/δ agonists form polar bonds with His287, His413 and Tyr437, while antagonists are more promiscuous about which amino acids they bind to, although they are very prone to bind Thr252 and Asn307. Dual binding in the PPARβ/δ binding pocket indicates the ligands retain similar binding energies, which suggests that co‐incubation with both agonist and antagonist does not prevent the specific binding of each other to the large PPARβ/δ binding pocket. To our knowledge, this is the first time that the possibility of binding two ligands simultaneously into the PPARβ/δ binding pocket has been explored. Agonist binding followed by antagonist simultaneously switches the PPARβ/δ mode of action from induction to transrepression, which is linked with an increase in Nos2 mRNA expression and nitrite production.Peer reviewedFinal Published versio