Supervisors info:
Βασίλειος Αϊδίνης, Ερευνητής Α', Ινστιτούτο Βιοκαινοτομίας, ΕΚΕΒΕ "Αλέξανδρος Φλέμινγκ"
Δημοσθένης Μπούρος, Ομότιμος Καθηγητής, Τμήμα Ιατρικής, ΕΚΠΑ
Βασιλική Κωστούρου, Ερευνήτρια Β', Ινστιτούτο Βιοκαινοτομίας, ΕΚΕΒΕ "Αλέξανδρος Φλέμινγκ"
Summary:
Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease, with a prognosis worse than many types of cancers, in which normal parenchymal tissue turns fibrous due to abnormal collagen production by fibroblasts. It has been shown that fibroblasts change their metabolic profile in order to obtain this anabolic metabolic phenotype by increasing glycolysis and oxidative phosphorylation levels. Additionally, macrophages that are involved in the formation of scar tissue in the IPF, specifically type M2, are initially attracted as monocytes by the extracellular LPA in the tissues and then converted to macrophages. We wanted to test whether the LPA produced by autotaxin (ATX), which plays a major role in the progression of pulmonary fibrosis, could cause such a change in fibroblasts and M2 macrophages. To achieve this, we used the Seahorse XF Analyzer platform where it quantifies with great sensitivity changes in pH and oxygen concentration in the medium of a cell culture and administered LPA to both 3T3-swiss fibroblasts and primary monocytes stimulated to differentiate to macrophages. In addition, we performed the MTT test where it measures the activity of succinate dehydrogenase, an enzyme that participates in the Crebs cycle and through it, the viability of fibroblasts. We did not notice any statistically significant difference as the levels of glycolysis and oxidative phosphorylation or viability in any type of cell did not change after exposure to LPA, which means that this change in cell metabolism may be due to another path independent of the ATX / LPA axis.
As for Non-Alcoholic Fatty Liver Disease (NAFLD), is a condition in which there is increased lipid deposition in the hepatocytes due to stimulus other than excessive alcohol consumption. It is a disease that is pathogenetically related to the intake of a high-fat diet and in general to energy expenditure imbalance. Based on this, we exposed C57Bl6 mice 6-7 weeks old to a high-fat diet for 10, 12, 16 weeks and a normal chow diet and checked the levels of characteristic indicators of the disease to establish the animal experimental model. These indicators were the aminotransferases of alanine and aspartate, which are indicators of liver damage, while the liver was also tested histologically to detect the expected liver steatosis. In addition, ATX plasma levels were quantified via TOOS assay and sections of the lungs and small intestine of the mice were examined so as to examine possible systemic effects after taking this diet. We observed that as early as 10 weeks the mouse phenotype was biochemically and histologically compatible to the disease, a picture we received at 12 weeks without significant differences. At 16 weeks, in addition to these observed differences and the relatively worse liver histology, another one was observed in bowel histology as severe lipid deposition in the enterocytes was seen, which can be interpreted as an aggravated disease. This observation could be useful in the examination and characterization of more advanced stages, but 10 weeks is a sufficient time to prove the induction of this pathology.
Keywords:
Non-alcoholic fatty liver disease, Idiopathic pulmonary fibrosis, Autotaxin, lpa
