PhD Scientific Days 2020

Molecular Sciences IV. Lectures

Investigation of Fatty Acid Desaturation and the Associated Electron Transfer Chain

Előadó neve

Somogyi, Anna

Előadó munkahelye

Semmelweis University, Department of Medical Chemistry, Molecular Biology and Pathobiochemistry

Előadó telefonszáma

+36202457747

Előadó e-mail címe

somogyi.anna@med.semmelweis-univ.hu

Az előadás címe

Investigation of Fatty Acid Desaturation and the Associated Electron Transfer Chain

Szerző(k) neve és munkahelye

Anna Somogyi1, Veronika Zámbó1, Judit Mátyási2, Farkas Sarnyai1, Péter Szelényi1, Éva Kereszturi1, Blanka Tóth2, Miklós Csala1
1 Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, Budapest, Hungary
2 Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Budapest, Hungary

Szekció

Molecular Sciences IV. Lectures

Language of the presentation

Hungarian

Section, first choice

Molecular Sciences

Section, second choice

Molecular Sciences

Összefoglaló szövege

Lipotoxicity has received a growing attention in the past decade, and it became evident that elevated free fatty acid (FFA) levels are deleterious to a wide variety of cells and tissues. Recent publications show, that the accumulation of triglycerides might have a protective role. However, during the synthesis of triglycerides, normally, a saturated fatty acyl group is attached to the first position of glycerol and an unsaturated fatty acyl group occupies the second position. Thus, the surplus of saturated or trans fatty acids (FAs) may block the triglyceride synthesis. Increased levels of saturation of membrane lipids can induce ER stress and hence it may cause severe malfunction of cells or even apoptosis. During the metabolism of FAs, FA-CoA molecules can be elongated or desaturated by ER-associated enzymes. In humans, one of the key enzymes of desaturation is the stearoyl-CoA desaturase 1 (SCD1), which inserts a cis double bond at the Δ9 position into saturated FAs. SCD1 receives electrons from NAD(P)H via cytochrome b5 reductase and cytochrome b5. Ncb5or is an oxidoreductase, which has a cytochrome b5 reductase like and cytochrome b5 like domain as well, thus it may also play a role in FA desaturation. In case of an oversupply of saturated FAs, expression of SCD1 or/and the associated electron transfer proteins may be induced to alleviate the toxic effects. Because of the presence of an alternative electron transfer chain, and the protective role of Ncb5or against palmitate toxicity, one may assume that there is a need for an enhancement of the chain.
In this work, we aimed to investigate the influence of the expression level of each protein involved in the desaturation process on the desaturating activity. We overexpressed SCD1, CYB5R, CYB5, NCB5OR, or their combinations in human HEK293T cells and analyzed the FA profile with our own developed and validated gas chromatography-flame ionization detection method with special attention on the alterations in the unsaturated/saturated ratio. Our results reveal that the level of the desaturase enzyme defines the cells’ capacity to desaturate FAs in our model, and the expression levels of the associated electron transfer chain components do not have any obvious impact on FA desaturation in a wide range. The physiological and pathological role of an alternative electron transfer still remains to be elucidated.

Additional Information

Supervisor: Miklós Csala
E-mail address: csala.miklos@med.semmelweis-univ.hu

Bemutatás módja

Szóbeli

Kind

Szabad

Status

elfogadva

Accepted presentation method

szóbeli

Előadás fájl jóváhagyás

nem rendelkezett róla

Előadó

4679

Start

11:40

End

11:55

Authors (legacy)

Anna Somogyi1, Veronika Zámbó1, Judit Mátyási2, Farkas Sarnyai1, Péter Szelényi1, Éva Kereszturi1, Blanka Tóth2, Miklós Csala1
1 Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, Budapest, Hungary
2 Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Budapest, Hungary