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DPP4 may play a relevant role in MSC differentiation into osteoblasts or adipocytes. Dipeptidyl peptidase 4 (DPP4) inhibitors (DPP4i), such as sitagliptin and vildagliptin, are used as antidiabetic drugs. However, vildagliptin is not a specific DPP4i and also inhibits DPP8/9, which is involved in energy metabolism and immune regulation. The aim of this study is to evaluate how sitagliptin, vildagliptin or 1G244 (a DPP8/9 specific inhibitor) may influence cell viability, as well as osteogenic and adipogenic differentiation in human mesenchymal stem cells (MSC). Viability, apoptosis, osteoblastogenesis and adipogenesis markers, as well as protein synthesis of β-catenin, were studied in MSC cultures induced to differentiate into osteoblasts or adipocytes in the presence or absence of sitagliptin, vildagliptin or 1G244. The two tested DPP4i did not affect MSC viability, but 1G244 significantly decreased it in MSC and osteoblast-induced cells. Additionally, 1G244 and vildagliptin inhibited osteogenesis and adipogenesis, unlike sitagliptin. Therefore, inhibition of DPP4 did not affect MSC viability and differentiation, whereas inhibition of DPP8/9 negatively affected MSC. To the best of our knowledge, these results show for the first time that DPP8/9 have an important role in the viability and differentiation of human MSC. This data can be considered for human clinical use of drugs affecting DPP8/9 activity.

Desde el año 2007, la Técnica del Insecto Estéril (TIE) es el principal medio de lucha del Plan de Acción de la Conselleria de Agricultura contra la mosca mediterránea de la fruta Ceratitis capitata Wiedemann (Diptera: Tephritidae) en la Comunitat Valenciana. Esta técnica consiste en la cría masiva de insectos macho de la misma especie a combatir que, tras ser esterilizados, se liberan al campo en grandes cantidades para que copulen con las hembras silvestres, siendo los huevos puestos por éstas infértiles.

En los últimos años, el creciente interés por buscar nuevos agentes de control biológico y el fácil acceso a las tecnologías de secuenciación masiva ha facilitado el descubrimiento de un gran número de virus presentes en insectos. Muchos de estos virus infectan de forma encubierta sin causar síntomas evidentes. Spodoptera exigua iflavirus 1 (SeIV1) es un virus de ARN que causa infecciones encubiertas tanto en las poblaciones de laboratorio como en las de campo de la rosquilla verde, Spodoptera exigua (Hübner). Su abundancia en el campo sugiere que podría causar un efecto sobre la bioecología del insecto, ya sea de forma directa afectando a su fisiología o de forma indirecta a través de la interacción con otros niveles tróficos.

International audience

Rafael Manuel Jiménez Díaz y María Milagros López González (eds.).

BACKGROUND The cotton leafworm, Spodoptera littoralis, is one of the most destructive pests in the Mediterranean basin, being predominantly controlled using synthetic chemical pesticides. Strain EAMa 01/58‐Su of the fungus Metarhizium brunneum and the parasitoid Hyposoter didymator are promising biological control agents for this pest. In this study, we assessed the compatibility between these two agents to control S. littoralis under joint attack scenarios. RESULTS Firstly, the direct and indirect effects of the fungus towards parasitoid adults were studied. The fungus significantly decreased life expectancy of the parasitoid (mortality=62.5%; mean lethal concentration=1.85×106 conidia ml‐1; average survival time=92.2h) when applied at high concentrations (108 conidia ml‐1), whereas it did not affect the reproductive potential of the parasitoid females during the three days after treatment. Secondly, the combinations between the two agents to control S. littoralis under different simultaneous use scenarios (inoculation of S. littoralis larvae with the fungus before being exposed to parasitoid females and vice versa) were investigated, with additive effect in all cases. A significant effect on fitness (preimaginal development time and reproductive potential) of the F1 parasitoid generation were detected. Moreover, parasitization significantly reduced the total haemocytes in S. littoralis haemolymph compared with the control, promoting fungal infection. Finally, parasitoids showed a significant preference for non‐inoculated S. littoralis larvae. CONCLUSIONS We demonstrated compatibility (additive effect) between fungus and parasitoid under different joint attack scenarios to control S. littoralis in laboratory conditions. However, this will be supported by our ongoing greenhouse and field studies.