Détermination des seuils de toxicité de divers insecticides (forme pure ou commerciale) sur cellules humaines en culture (A549, SH-SY5Y) : expression des gènes et protéines de stress (HSPs, GRPs,…)

Cytotoxicity thresholds of divers insecticides on human cultured cell lines (A549, SH-SY5Y) : Gène and protein expression (HSPs, GRPs,…)

• Auteur / Autrice : Dalila Skandrani
• Direction : Françoise Croute
• Type : Thèse de doctorat
• Discipline(s) : Biologie cellulaire et moléculaire
• Date : Soutenance en 2006
• Etablissement(s) : Toulouse 3

Mots clés

Mots clés contrôlés

Toxicologie

Insecticides

Effets des insecticides

Mots clés libres

Formetanate

Methomyl

Pyrimicarbe

Diénochlore

Endosulfan

Imidaclopride

Bifenthrine

Cytotoxicité

Grp78

Top2a

Gadd153

Udpgt

Gst12

Sod2

Résumé

Ce travail a eu pour but de déterminer les concentrations cytotoxiques de divers insecticides (molécule pure versus formulation commerciale) qui induisaient une inhibition de la prolifération de cellules d'origine pulmonaire (A549) ou neuronale (SH-SY5Y) et d'analyser les variations d'expression de gènes de stress par la technique des cDNA arrays et/ou des protéines (HSP, GRP) sur western blot. Il a été montré que les formulations pouvaient être jusqu'à 150 fois plus toxiques que les molécules pures. Dans les cellules A549, les insecticides ont induit une surexpression de la GRP78 et une sous-expression des HSPs. Le formetanate (pur ou commercial) a induit une surexpression des transcrits GADD153 et diverses GST et UDPGT. Le Dicarzol a induit une surexpression des transcrits SOD2 et TOP2A.

Toxicity of several insecticides was determined in vitro on lung adenocarcinoma A549 and neuroblastoma SH-SY5Y cell lines, with the aim to find out, among stress proteins, reliable and sensitive markers of occupational or accidental exposure. Carbamates (formétanate, methomyl, pyrimicarb), organochlorines (dienochlor, endosulfan), pyrethroid (bifenthrin) and neonicotinoid (imidacloprid) insecticides were comparatively investigated either as pure chemical or as commercial formulations. Measurement of threshold concentrations (LOEC) leading to a significant decrease of the growth-rate in A549 cells showed that organochlorines were the most toxic whereas imidacloprid and methomyl were the less toxic. SH-SY5Y cells were found to be more sensitive than A549. When compared at similar concentration of active principle, commercial formulations were found to be twice to 100 times more aggressive than the respective pure active molecule. In A549, GRP78 stress protein was up-regulated by almost all the insecticides, commercial formulations being more efficient. No such effect was observed in SH-SY5Y. Conversely, cytosolic HSP72/73 stress proteins were somewhat underexpressed in all cases. . .