Fuertes-Agudo 2019 MiPschool Coimbra

From Bioblast
Jump to: navigation, search
Marina Fuertes Agudo Role of COX-2 in liver and heart mitochondrial function.

Link: MitoEAGLE

Fuertes Agudo M, Cucarella C, Casanova N, Brea R, Bosca L, Martin-Sanz P, Casado M (2019)

Event: MiPschool Coimbra 2019

COST Action MitoEAGLE

Liver and heart are two principal organs in an organism. Although their physiology is extremely different, both tissues have in common that adult hepatocytes and cardiomyocytes fail to induce COX-2 expression, the key enzyme in the synthesis of prostaglandins, regardless of the pro-inflammatory factors used. In both cell types, COX-2 expression is restricted to those situations in which dedifferentiation or proliferation occur. In parallel studies, using mice genetically modified to selectively express hCOX-2 in hepatocytes [1] and cardiomyocytes [2], we have demonstrated an increased tolerance to ischemia-reperfusion injury (IRI) with an increased functional recovery, a diminished cellular necrosis and less inflammation. It is known that mitochondria have a major role in IRI damage by increasing oxidative stress, decoupling metabolic state and inducing apoptosis. In this work, we analysed different aspects in order to characterize the impact of COX-2 in mitochondrial function.

We performed high-resolution respirometry with isolated mitochondria and liver homogenates from transgenic mice overexpressing the human COX-2 specifically in hepatocytes (hCOX-2-Tg), as well as analysed the expression of different components of the electron transport chain supercomplexes, mitochondria morphology by transfer electron microscopy, fusion/fission events, etc. Our results from the high-resolution respirometry suggest that hCOX-2-Tg mice-derived mitochondria are more active than wild-type-derived mitochondria, apparently because of a higher contribution from fatty acids metabolism. An increase in the Acox gene expression, a principal enzyme in beta oxidation, supports the hypothesis of a major role of fatty acid metabolism in this model. Furthermore, we have analysed respirometry analysis in permeabilized soleus and cardiac fibres. Interestingly, when overexpressing COX-2 specifically in hepatocytes, the activity of complex IV in cardiomyocytes is increased, revealing a possible crosstalk between organs. To further explore these results, we carried out the differential proteome analysis of wild-type vs. transgenic mice derived cardiomyocytes. The results revealed a specific proteomic profile dominated by mitochondrial proteins. Quantitative proteomic analysis showed increased expression of respiratory chain complex IV proteins. This was correlated with a higher catalytic activity, an improved respiratory capacity, and an increase of ATP levels in the heart from human COX-2 transgenic mice. These data suggest a new link between COX-2 and mitochondria, which might contribute to the protective effects of COX-2 against IRI.


Bioblast editor: Plangger M O2k-Network Lab: ES Valencia Casado Pinna M


Labels: MiParea: Respiration, Genetic knockout;overexpression 


Organism: Mouse  Tissue;cell: Heart, Skeletal muscle, Liver  Preparation: Permeabilized tissue, Homogenate, Isolated mitochondria 



HRR: Oxygraph-2k 


Affiliations

Fuertes-Agudo M(1), Cucarella C(1), Casanova N(2), Brea R(2), Boscá L(2,3), Martín-Sanz P(2,4), Casado M(1,4)
  1. Inst Biomedicina Valencia (IBV-CSIC), Valencia, Spain
  2. Inst Investigaciones Biomédicas “Alberto Sols” (IIB-UAM)
  3. Centro Investigación Biomédica en Red Enfermedades Cardiovasculares (CIBERcv)
  4. Centro Investigación Biomédica en Red Enfermedades Hepáticas y Digestivas (CIBERehd); Madrid, Spain. - mfuertes@ibv.csic.es

References

  1. Motiño O, Francés DE, Casanova N, Fuertes-Agudo M, Cucarella C, Flores JM, Vallejo-Cremades MT, Olmedilla L, Pérez-Peña J, Bañares R Boscá L, Casado M, Martín-Sanz P (2019) Protective Role of Hepatocyte Cyclooxygenase-2 Expression Against Liver Ischemia–Reperfusion Injury in Mice. Hepatology 0:1–16.
  2. Inserte J, Molla B, Aguilar R, Través PG, Barba I, Martín-Sanz P, Boscá L, Casado M, García-Dorado D (2009) Constitutive COX-2 activity in cardiomyocytes confers permanent cardioprotection. Constitutive COX-2 expression and cardioprotection. J Mol Cell Cardiol 46:160–68.