Chronic Methylmercury Intoxication Induces Systemic Inflammation, Behavioral, and Hippocampal Amino Acid Changes in C57BL6J Adult Mice.
Tyciane S NascimentoDaniel V PintoRonaldo P DiasRamon S RaposoPaulo Iury Gomes NunesCássia R RoqueFlavia Almeida SantosGeanne M AndradeJosé Lucas VianaAnne H FostierAlessandra SussuliniJacqueline I Alvarez-LeiteCarlos Fontes RibeiroJoão O MalvaReinaldo B OriáPublished in: International journal of molecular sciences (2022)
Methylmercury (MeHg) is highly toxic to the human brain. Although much is known about MeHg neurotoxic effects, less is known about how chronic MeHg affects hippocampal amino acids and other neurochemical markers in adult mice. In this study, we evaluated the MeHg effects on systemic lipids and inflammation, hippocampal oxidative stress, amino acid levels, neuroinflammation, and behavior in adult male mice. Challenged mice received MeHg in drinking water (2 mg/L) for 30 days. We assessed weight gain, total plasma cholesterol (TC), triglycerides (TG), endotoxin, and TNF levels. Hippocampal myeloperoxidase (MPO), malondialdehyde (MDA), acetylcholinesterase (AChE), amino acid levels, and cytokine transcripts were evaluated. Mice underwent open field, object recognition, Y, and Barnes maze tests. MeHg-intoxicated mice had higher weight gain and increased the TG and TC plasma levels. Elevated circulating TNF and LPS confirmed systemic inflammation. Higher levels of MPO and MDA and a reduction in IL-4 transcripts were found in the hippocampus. MeHg-intoxication led to increased GABA and glycine, reduced hippocampal taurine levels, delayed acquisition in the Barnes maze, and poor locomotor activity. No significant changes were found in AChE activity and object recognition. Altogether, our findings highlight chronic MeHg-induced effects that may have long-term mental health consequences in prolonged exposed human populations.
Keyphrases
- amino acid
- weight gain
- high fat diet induced
- oxidative stress
- drinking water
- cerebral ischemia
- body mass index
- mental health
- birth weight
- rheumatoid arthritis
- spinal cord injury
- traumatic brain injury
- dna damage
- working memory
- adipose tissue
- minimally invasive
- cognitive impairment
- blood brain barrier
- ischemia reperfusion injury
- cell death
- pi k akt
- high density