In vitro effect of diazoxon on cell signaling and second messengers in Nile tilapia (Oreochromis niloticus)
Milton Rafael Camacho-Pérez1,2,3, Karina Janice Guadalupe Díaz-Resendiz2,3, Rocío Ortiz-Butrón4
1Programa de Maestría en Ciencias Biológico Agropecuarias, Universidad Autónoma de Nayarit, Carretera Tepic-Compostela Km. 9. Xalisco, Nayarit C.P. 63780, México.
Abstract:
The physiological and molecular responses of leukocytes are altered by organophosphate pesticides. Some reports have shown that diazinon causes immunotoxic effects; diazoxon, the oxon metabolite of diazinon, is attributed to influence the immune response by affecting the leukocyte cholinergic system. In this study, the in vitro effects of diazoxon on molecules involved in cell signaling (cAMP, IP3, DAG, JAK1, and STAT3), which play a crucial role in the activation, differentiation, and survival of leukocytes, were evaluated. Data indicate that diazoxon leads to a decrease in cAMP concentration and an increase in basal IP3 levels. However, diazoxon does not affect basal levels of JAK1 and STAT3 phosphorylation. Instead, diazoxon inhibits leukocyte responsiveness to phorbol myristate acetate and ionomycin, substances that, under normal conditions, enhance JAK/STAT signaling. These findings demonstrate that diazoxon significantly affects key molecular parameters related to cell signaling.
Insights
Diazoxon, an organophosphate pesticide metabolite, disrupts leukocyte cell signaling by altering cyclic adenosine monophosphate (cAMP) and inositol trisphosphate (IP3) levels. It also inhibits immune cell responses crucial for activation and survival.
Area of Science:
- Immunotoxicology
- Molecular Biology
- Environmental Health
Background:
- Organophosphate pesticides can cause immunotoxic effects.
- Diazoxon, a metabolite of diazinon, affects the leukocyte cholinergic system and influences immune responses.
Purpose of the Study:
- To investigate the in vitro effects of diazoxon on key cell signaling molecules in leukocytes.
- To evaluate the impact of diazoxon on cyclic adenosine monophosphate (cAMP), inositol trisphosphate (IP3), diacylglycerol (DAG), Janus kinase 1 (JAK1), and signal transducer and activator of transcription 3 (STAT3).
Main Methods:
- In vitro assessment of diazoxon's impact on leukocyte signaling pathways.
- Measurement of intracellular cAMP and IP3 levels.
- Analysis of JAK1 and STAT3 phosphorylation.
- Evaluation of leukocyte responsiveness to phorbol myristate acetate and ionomycin stimulation.
Main Results:
- Diazoxon significantly decreased cAMP concentration in leukocytes.
- Diazoxon increased basal IP3 levels.
- No significant changes were observed in basal JAK1 and STAT3 phosphorylation.
- Diazoxon inhibited leukocyte activation in response to phorbol myristate acetate and ionomycin, which normally enhance JAK/STAT signaling.
Conclusions:
- Diazoxon demonstrably alters critical molecular parameters involved in leukocyte cell signaling.
- The findings highlight diazoxon's potential to disrupt immune cell function through modulation of intracellular signaling pathways.
