5-Hydroxytryptamine, Glutamate, and ATP: Much More Than Neurotransmitters

Neurotransmitters: Impressive regulators of tumor progression

In contemporary times, tumors have emerged as the primary cause of mortality in the global population. Ongoing research has shed light on the significance of neurotransmitters in the regulation of tumors. It has been established that neurotransmitters play a pivotal role in tumor cell angiogenesis by triggering the transformation of stromal cells into tumor cells, modulating receptors on tumor stem cells, and even inducing immunosuppression. These actions ultimately foster the proliferation and metastasis of tumor cells. Several major neurotransmitters have been found to exert modulatory effects on tumor cells, including the ability to restrict emergency hematopoiesis and bind to receptors on the postsynaptic membrane, thereby inhibiting malignant progression. The abnormal secretion of neurotransmitters is closely associated with tumor progression, suggesting that focusing on neurotransmitters may yield unexpected breakthroughs in tumor therapy. This article presents an analysis and outlook on the potential of targeting neurotransmitters in tumor therapy.

The underlying mechanism of calcium toxicity-induced autophagic cell death and lysosomal degradation in early stage of cerebral ischemia

Cerebral ischemia is the important cause of worldwide disability and mortality, that is one of the obstruction of blood vessels supplying to the brain. In early stage, glutamate excitotoxicity and high level of intracellular calcium (Ca2+) are the major processes which can promote many downstream signaling involving in neuronal death and brain tissue damaging. Moreover, autophagy, the reusing of damaged cell organelles, is affected in early ischemia. Under ischemic conditions, autophagy plays an important role to maintain energy of the brain and its function. In the other hand, over intracellular Ca2+ accumulation triggers excessive autophagic process and lysosomal degradation leading to autophagic process impairment which finally induce neuronal death. This article reviews the association between intracellular Ca2+ and autophagic process in acute stage of ischemic stroke.

Excessive level of dietary insect protein negatively changed growth metabolomic and transcriptomic profiles of largemouth bass (Micropterus salmoides)

Hermetia illucens (HI) meal is a promising substitute for fish meal (FM) in the feeds of farmed fish. However, the impacts of dietary HI meal on largemouth bass (LMB) remain unknown. In this study, we formulated three isonitrogenous and isolipid diets with 0% (HI0, control), 20% (HI20) and 40% (HI40) of FM substituted by HI meal. A total of 270 juvenile largemouth bass with an initial body weight of 10.02 ± 0.03 g were used (30 fish per tank). After an 80-day feeding trial, the fish fed with the HI40 diet demonstrated decreased growth performance and protein efficiency ratio (PER), and increased liver oxidative indices and lipid accumulation compared to the control (P < 0.05). Transcriptomic analysis revealed the effects of high dietary HI meal on liver gene expression. Consistent with the reduced growth and disturbed liver oxidative status, the upregulated genes were enriched in the biological processes associated with protein catabolism and endoplasmic reticulum (ER) stress; while the downregulated genes were enriched in cellular proliferation, growth, metabolism, immunity and maintenance of tissue homeostasis. Differential metabolites in the liver samples were also identified by untargeted metabolomic assay. The results of joint transcriptomic-metabolomic analyses revealed that the pathways such as one carbon pool by folate, propanoate metabolism and alpha-linolenic acid metabolism were disturbed by high dietary HI meal. In summary, our data revealed the candidate genes, metabolites and biological pathways that account for the adverse effects of high HI meal diet on the growth and health of LMB.

UHPLC-MS/MS combined with microdialysis for simultaneous determination of nicotine and neurotransmitter metabolites in the rat hippocampal brain region: application to pharmacokinetic and pharmacodynamic study

Nicotine crosses the blood-brain barrier and interacts with nicotinic acetylcholine receptors, initiating a cascade of neurotransmitter effects with potential therapeutic implications for neurodegenerative conditions such as Alzheimer's and Parkinson's disease. The hippocampus, pivotal for cognitive processes, plays a crucial role in nicotine-mediated cognitive enhancement due to its abundant expression of nicotinic acetylcholine receptors, particularly the α7 subtype, which is heavily implicated in hippocampus-related behavioral functions and dysfunctions. However, the intricate process of nicotine metabolism within the hippocampus remains poorly understood, impeding our comprehension of how nicotine and its metabolites modulate neurotransmitter dynamics. To address this gap, we have developed and validated a novel methodology combining microdialysis with UHPLC-MS/MS, enabling simultaneous detection of 12 neurotransmitters, nicotine, and its seven metabolites within the rat hippocampus. The linearity range of the targeted compounds is satisfactory (R2 > 0.9970), with intra-day and inter-day precision not exceeding 12.7%, and accuracy ranging from -12.4% to 13.7%. Our findings reveal differential pharmacokinetics of nicotine and its metabolites in the α7KO group compared to the control group, characterized by heightened nicotine absorption and slower elimination and distribution in the former. Notably, the pharmacokinetic parameters of cotinine exhibit similarity across both groups. Studies investigating the impact of nicotine on monoamine neurotransmitters have elucidated its capacity to augment the release of dopamine, serotonin, norepinephrine, glutamate, and acetylcholine in the rat hippocampus. This integrated approach facilitates a comprehensive analysis of neurotransmitter alterations within the hippocampal region following nicotine administration, thereby providing robust technical support and scientific rationale for understanding the neurochemical effects of nicotine and its metabolites. Further exploration into the pharmacokinetics and pharmacodynamics of nicotine holds promise for uncovering novel therapeutic avenues in the management of neurodegenerative diseases such as Alzheimer's.