Dysfunction of programmed embryo senescence is linked to genetic developmental defects.

Developmental senescence is a form of programmed senescence that contributes to morphogenesis during embryonic development. We showed recently that the SIX1 homeoprotein, an essential regulator of organogenesis, is also a repressor of adult cellular senescence. Alterations in the SIX/EYA pathway are linked to the human branchio-oto-renal (BOR) syndrome, a rare congenital disorder associated with defects in the ears, kidneys and branchial arches. Here, we have used Six1-deficient mice, an animal model of the BOR syndrome, to investigate whether dysfunction of senescence underpins the developmental defects associated with SIX1 deficiency. We have focused on the developing inner ear, an organ with physiological developmental senescence that is severely affected in Six1-deficient mice and BOR patients. We show aberrant levels and distribution of senescence markers in Six1-deficient inner ears concomitant with defective morphogenesis of senescent structures. Transcriptomic analysis and ex vivo assays support a link between aberrant senescence and altered morphogenesis in this model, associated with deregulation of the TGFß/BMP pathway. Our results show that misregulation of embryo senescence may lead to genetic developmental disorders, significantly expanding the connection between senescence and disease.

Development of a Novel Targeted Metabolomic LC-QqQ-MS Method in Allergic Inflammation.

The transition from mild to severe allergic phenotypes is still poorly understood and there is an urgent need of incorporating new therapies, accompanied by personalized diagnosis approaches. This work presents the development of a novel targeted metabolomic methodology for the analysis of 36 metabolites related to allergic inflammation, including mostly sphingolipids, lysophospholipids, amino acids, and those of energy metabolism previously identified in non-targeted studies. The methodology consisted of two complementary chromatography methods, HILIC and reversed-phase. These were developed using liquid chromatography, coupled to triple quadrupole mass spectrometry (LC-QqQ-MS) in dynamic multiple reaction monitoring (dMRM) acquisition mode and were validated using ICH guidelines. Serum samples from two clinical models of allergic asthma patients were used for method application, which were as follows: (1) corticosteroid-controlled (ICS, n = 6) versus uncontrolled (UC, n = 4) patients, and immunotherapy-controlled (IT, n = 23) versus biologicals-controlled (BIO, n = 12) patients. The results showed significant differences mainly in lysophospholipids using univariate analyses in both models. Multivariate analysis for model 1 was able to distinguish both groups, while for model 2, the results showed the correct classification of all BIO samples within their group. Thus, this methodology can be of great importance for further understanding the role of these metabolites in allergic diseases as potential biomarkers for disease severity and for predicting patient treatment response.