Mitochondrial Protein UCP2 Controls Pancreas Development

The mitochondrial carrier uncoupling protein (UCP) 2 belongs to the family of the UCPs. Despite its name, it is now accepted that UCP2 is rather a metabolite transporter than a UCP. UCP2 can regulate oxidative stress and/or energetic metabolism. In rodents, UCP2 is involved in the control of α- and β-cell mass as well as insulin and glucagon secretion. Our aim was to determine whether the effects of UCP2 observed on β-cell mass have an embryonic origin. Thus, we used Ucp2 knockout mice. We found an increased size of the pancreas in Ucp2^-/- fetuses at embryonic day 16.5, associated with a higher number of α- and β-cells. This phenotype was caused by an increase of PDX1⁺ progenitor cells. Perinatally, an increase in the proliferation of endocrine cells also participates in their expansion. Next, we analyzed the oxidative stress in the pancreata. We quantified an increased nuclear translocation of nuclear factor erythroid 2-related factor 2 (NRF2) in the mutant, suggesting an increased production of reactive oxygen species (ROS). Phosphorylation of AKT, an ROS target, was also activated in the Ucp2^-/- pancreata. Finally, administration of the antioxidant N-acetyl-l-cysteine to Ucp2^-/- pregnant mice alleviated the effect of knocking out UCP2 on pancreas development. Together, these data demonstrate that UCP2 controls pancreas development through the ROS-AKT signaling pathway.

Chikungunya outbreak in Montpellier, France, September to October 2014

In October 2014, an outbreak of 12 autochthonous chikungunya cases, 11 confirmed and 1 probable, was detected in a district of Montpellier, a town in the south of France colonised by the vector Aedes albopictus since 2010. A case returning from Cameroon living in the affected district was identified as the primary case. The epidemiological investigations and the repeated vector control treatments performed in the area and around places frequented by cases helped to contain the outbreak. In 2014, the chikungunya and dengue surveillance system in mainland France was challenged by numerous imported cases due to the chikungunya epidemic ongoing in the Caribbean Islands. This first significant outbreak of chikungunya in Europe since the 2007 Italian epidemic, however, was due to an East Central South African (ECSA) strain, imported by a traveller returning from West Africa. Important lessons were learned from this episode, which reminds us that the threat of a chikungunya epidemic in southern Europe is real.

Diphtheria in the south of France, March 2011

In March 2011, a 40 year-old French man was diagnosed with diphtheria caused by toxigenic Corynebacterium diphtheriae. Fifty-three close contacts were identified from whom throat samples were analysed. C. diphtheriae was found only in the asymptomatic partner of the index case. The two cases had travelled in Spain during the incubation period of the index case. Investigation around the second case identified 13 new close contacts.None of them was found to be infected.

Diphtheria in the south of France, March 2011

In March 2011, a 40 year-old French man was diagnosed with diphtheria caused by toxigenic Corynebacterium diphtheriae. Fifty-three close contacts were identified from whom throat samples were analysed. C. diphtheriae was found only in the asymptomatic partner of the index case. The two cases had travelled in Spain during the incubation period of the index case. Investigation around the second case identified 13 new close contacts. None of them was found to be infected.