Chemotherapy-induced peripheral neurotoxicity (CIPN) is a severe dose-limiting adverse event of chemotherapy. Presently, the mechanism underlying the induction of CIPN remains unclear, and no effective treatment is available. In this study, through metabolomics analyses, we found that nab-paclitaxel therapy markedly increased serum serotonin [5-hydroxtryptamine (5-HT)] levels in both cancer patients and mice compared to the respective controls. Furthermore, nab-paclitaxel-treated enterochromaffin (EC) cells showed increased 5-HT synthesis, and serotonin-treated Schwann cells showed damage, as indicated by the activation of CREB3L3/MMP3/FAS signaling. Venlafaxine, an inhibitor of serotonin and norepinephrine reuptake, was found to protect against nerve injury by suppressing the activation of CREB3L3/MMP3/FAS signaling in Schwann cells. Remarkably, venlafaxine was found to significantly alleviate nab-paclitaxel-induced CIPN in patients without affecting the clinical efficacy of chemotherapy. In summary, our study reveals that EC cell-derived 5-HT plays a critical role in nab-paclitaxel-related neurotoxic lesions, and venlafaxine co-administration represents a novel approach to treating chronic cumulative neurotoxicity commonly reported in nab-paclitaxel-based chemotherapy.
Paclitaxel/toxicity* ; Animals ; Albumins/adverse effects* ; Serotonin/metabolism* ; Mice ; Humans ; Male ; Female ; Venlafaxine Hydrochloride/therapeutic use* ; Neurotoxicity Syndromes/metabolism* ; Middle Aged ; Schwann Cells/metabolism* ; Peripheral Nervous System Diseases/drug therapy* ; Antineoplastic Agents

It has been confirmed that exposure to various metal pollutants can induce neurotoxicity, which is closely associated with the occurrence and development of neurological disorders. Ferroptosis is a form of cell death in response to metal pollutant exposure and it is closely related to oxidative stress, iron metabolism and lipid peroxidation. Recent studies have revealed that ferroptosis plays a significant role in the neurotoxicity induced by metals such as lead, cadmium, manganese, nickel, and antimony. Lead exposure triggers ferroptosis through oxidative stress, iron metabolism disorder and inflammation. Cadmium can induce ferroptosis through iron metabolism, oxidative stress and ferroptosis related signaling pathways. Manganese can promote ferroptosis through mitochondrial dysfunction, iron metabolism disorder and oxidative stress. Nickel can promote ferroptosis by influencing mitochondrial function, disrupting iron homeostasis and facilitating lipid peroxidation in the central nervous system. Antimony exposure can induce glutathione depletion by activating iron autophagy, resulting in excessive intracellular iron deposition and ultimately causing ferroptosis. This article reviews the effects of metal pollutants on ferroptosis-related indicators and discusses the specific mechanisms by which each metal triggers ferroptosis. It provides a reference for identifying targets for preventing neurotoxicity and for developing treatment strategies for neurological disorders.
Ferroptosis/drug effects* ; Humans ; Iron/metabolism* ; Oxidative Stress/drug effects* ; Neurotoxicity Syndromes/metabolism* ; Cadmium/adverse effects* ; Animals ; Lipid Peroxidation/drug effects* ; Metals/metabolism* ; Lead/adverse effects* ; Environmental Pollutants/toxicity* ; Manganese/adverse effects* ; Nickel/adverse effects* ; Mitochondria/drug effects* ; Signal Transduction/drug effects*

OBJECTIVETo investigate acrylamide (ACR)-induced subacute neurotoxic effects on the central nervous system (CNS) at the synapse level in rats.

METHODSThirty-six Sprague Dawley (SD) rats were randomized into three groups, (1) a 30 mg/kg ACR-treated group, (2) a 50 mg/kg ACR-treated group, and (3) a normal saline (NS)-treated control group. Body weight and neurological changes were recorded each day. At the end of the test, cerebral cortex and cerebellum tissues were harvested and viewed using light and electron microscopy. Additionally, the expression of Synapsin I and P-Synapsin I in the cerebral cortex and cerebellum were investigated.

RESULTSThe 50 mg/kg ACR-treated rats showed a significant reduction in body weight compared with untreated individuals (P < 0.05). Rats exposed to ACR showed a significant increase in gait scores compared with the NS control group (P < 0.05). Histological examination indicated neuronal structural damage in the 50 mg/kg ACR treatment group. The active zone distance (AZD) and the nearest neighbor distance (NND) of synaptic vesicles in the cerebral cortex and cerebellum were increased in both the 30 mg/kg and 50 mg/kg ACR treatment groups. The ratio of the distribution of synaptic vesicles in the readily releasable pool (RRP) was decreased. Furthermore, the expression levels of Synapsin I and P-Synapsin I in the cerebral cortex and cerebellum were decreased in both the 30 mg/kg and 50 mg/kg ACR treatment groups.

CONCLUSIONSubacute ACR exposure contributes to neuropathy in the rat CNS. Functional damage of synaptic proteins and vesicles may be a mechanism of ACR neurotoxicity.

Acrylamide ; toxicity ; Animals ; Cerebellum ; cytology ; drug effects ; Cerebral Cortex ; cytology ; drug effects ; Drug Administration Schedule ; Gait ; Gene Expression Regulation ; drug effects ; Male ; Neurons ; drug effects ; Neurotoxicity Syndromes ; pathology ; Rats ; Rats, Sprague-Dawley ; Synapses ; drug effects ; Synapsins ; genetics ; metabolism ; Synaptic Vesicles ; drug effects ; physiology ; Weight Loss ; drug effects

Appropriate selection and measurement of lead biomarkers of exposure are critically important for health care management purposes, public health decision making, and primary prevention synthesis. Lead is one of the neurotoxicants that seems to be involved in the etiology of psychologies. Biomarkers are generally classified into three groups: biomarkers of exposure, effect, and susceptibility.The main body compartments that store lead are the blood, soft tissues, and bone; the half-life of lead in these tissues is measured in weeks for blood, months for soft tissues, and years for bone. Within the brain, lead-induced damage in the prefrontal cerebral cortex, hippocampus, and cerebellum can lead to a variety of neurological disorders, such as brain damage, mental retardation, behavioral problems, nerve damage, and possibly Alzheimer's disease, Parkinsons disease, and schizophrenia. This paper presents an overview of biomarkers of lead exposure and discusses the neurotoxic effects of lead with regard to children and adults.
Alzheimer Disease ; chemically induced ; metabolism ; pathology ; physiopathology ; psychology ; Animals ; Behavior ; drug effects ; Biomarkers ; metabolism ; Brain ; metabolism ; pathology ; physiopathology ; Brain Diseases ; chemically induced ; pathology ; physiopathology ; Environmental Exposure ; adverse effects ; Humans ; Lead ; pharmacokinetics ; toxicity ; Lead Poisoning ; etiology ; metabolism ; pathology ; physiopathology ; psychology ; Neurotoxicity Syndromes ; etiology ; metabolism ; pathology ; physiopathology ; psychology ; Parkinson Disease, Secondary ; chemically induced ; metabolism ; pathology ; physiopathology ; psychology ; Schizophrenia ; chemically induced ; metabolism ; pathology ; physiopathology

Dexmedetomidine and midazolam have been widely used in clinical anesthesia and intensive care unit sedation. These two drugs differ in sedative mechanism. We hypothesized that the neurotoxicity of repeated exposure to dexmedetomidine or midazolam for neonatal mice might be different. Twenty four mice of postnatal day 8 were randomly divided into control (n=8), dexmedetomidine (n=8) and midazolam group (n=8) respectively. In the three groups, saline(10mL/kg), dexmedetomidine(10microg/kg) or midazolam(40mg/kg) was injected intraperitoneally once a day, in the next five days, respectively. Then the brains of the mice in the three qroups were removed and cryosectioned. Apoptotic neural cell in hippocampus region was detected with terminal deoxynucleotydyl transferase -mediated dUTP nick end labeling(TUNEL). Bcl2 and Bax protein expression level in the hippocampus were determined by immunofluorescent staining. In the present study, the number of TUNEL-positive cells from midazolam group ((20 +/-3) /mm2) was larger than that from dexmedetomidine group ((15+/-2) /mm2, P<0. 05) and control group((13+/-3) /mm2, P<0. 05); Bcl-2 protein quantity in hippocampus from control group((790+/-103)/mm2)was significantly lower than that in midazolam group((1187+/- 162)/mm2, P<0.05)and dexmedetomidine group((890+/-125)/mm2, P<0. 05). Bax protein level in control group((942+/-104)/mm2) was also significantly lower than that in midazolam group((1839+/-160)/mm2, P<0. 05)and dexmedetomidine group((1143+/-125)/mm2, P<0. 05); Bax/Bcl-2 ratio in midazolam group(0. 64+/-0. 13) was significantly lower than that in dexmedetomidine group(0. 78 +/-0. 14, P<0. 05) and control group(0. 84+/-0. 15, P<0. 05). Our results suggest that dexmedetomidine has lower neurotoxicity than midazolam for neonatal mice.
Animals ; Animals, Newborn ; Apoptosis ; drug effects ; Dexmedetomidine ; toxicity ; Hippocampus ; drug effects ; pathology ; Mice ; Mice, Inbred C57BL ; Midazolam ; toxicity ; Neurons ; drug effects ; pathology ; Neurotoxicity Syndromes ; etiology ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; bcl-2-Associated X Protein ; metabolism

OBJECTIVETo investigate the mechanisms of taurine (Tau) preventive effect on neurotoxicity induced by manganese (Mn) in rat's prefrontal cortex.

METHODSSD rats were divided into four groups after one week of observation: normal control:the group animals received daily intraperitoneal (ip.) injections of sterile saline for 3 months; Mn treated group (Mn): rats received ip. injection of MnCl(2).4H(2)O once a day for 3 months; Tau preventive group (Mn + Tau): The Mn level of this group were the same as Mn's, the Tau level 200 mg/kg, three times per week, for 3 months; Tau treated group (Mn-->Tau): After received the daily injection of Mn as Mn group for 3 months, the rats received Tau three times per week for 3 months. The dose of Mn and Tau were the same as above. The experiment lasted 6 months.

RESULTS(1) Mn induced apoptosis of neurons in rat's prefrontal cortex. The ratio of apoptosis of neurons in the Mn treated group [(20.0 +/- 4.3)%] was higher than that of the control group [(1.8 +/- 2.1)%] (P < 0.05) and the ratio of apoptosis in Tau preventive group (Mn + Tau) was lower than that of the Mn treated group (P < 0.05). (2) The production of MDA in Mn treated group was higher than the control group (P < 0.05) and the activity of SOD was lower than that in the control group. In Tau preventive group (Mn + Tau), Tau increased the activity of SOD and decreased the production of the MDA, with the significant difference level compared to the Mn treated group (P < 0.05).

CONCLUSIONMn induces apoptosis in rat's prefrontal cortex neurons. The main mechanisms of Tau preventing cytotoxicity against Mn is the reduction of the oxidative stress in prefrontal cortex neurons.

Animals ; Apoptosis ; drug effects ; Drug Antagonism ; Male ; Manganese ; toxicity ; Neurons ; drug effects ; metabolism ; pathology ; Neurotoxicity Syndromes ; etiology ; metabolism ; pathology ; prevention & control ; Prefrontal Cortex ; drug effects ; metabolism ; pathology ; Rats ; Rats, Sprague-Dawley ; Taurine ; pharmacology

OBJECTIVETo investigate a possibility of repairing damaged brain by intracerebroventricular transplantation of neural stem cells (NSCs) in the adult mice subjected to glutamate-induced excitotoxic injury.

METHODSMouse NSCs were isolated from the brains of embryos at 15-day postcoitum (dpc). The expression of nestin, a special antigen for NSC, was detected by immunocytochemistry. Immunofluorescence staining was carried out to observe the survival and location of transplanted NSCs. The animals in the MSG + NSCs group received intracerebroventricular transplantation of NSCs (approximately 1.0 x 10(5) cells) separately on day 1 and day 10 after 10-d MSG exposure (4.0 g/kg per day). The mice in control and MSG groups received intracerebroventricular injection of Dulbecco's minimum essential medium (DMEM) instead of NSCs. On day 11 after the last NSC transplantation, the test of Y-maze discrimination learning was performed, and then the histopathology of the animal brains was studied to analyze the MSG-induced functional and morphological changes of brain and the effects of intracerebroventricular transplantation of NSCs on the brain repair.

RESULTSThe isolated cells were Nestin-positive. The grafted NSCs in the host brain were region-specifically survived at 10-d post-transplantation. Intracerebroventricular transplantation of NSCs obviously facilitated the brain recovery from glutamate-induced behavioral disturbances and histopathological impairs in adult mice.

CONCLUSIONIntracerebroventricular transplantation of NSCs may be feasible in repairing diseased or damaged brain tissue.

Animals ; Cell Count ; Disease Models, Animal ; Embryo, Mammalian ; Glutamic Acid ; toxicity ; Injections, Intraventricular ; methods ; Intermediate Filament Proteins ; metabolism ; Mice ; Mice, Inbred Strains ; Nerve Tissue Proteins ; metabolism ; Nestin ; Neurons ; physiology ; Neurotoxicity Syndromes ; etiology ; pathology ; surgery ; Stem Cell Transplantation ; methods ; Stem Cells ; physiology ; Time Factors

OBJECTIVETo study the role of N-methyl-D-aspartate receptor 1 in acute intoxicated encephalopathy induced by 1,2- dichloroethane(1,2-DCE).

METHODSForty-two Sprague-Dawley rats, which had been randomly divided into 1 control, 3 exposure and 3 after-exposure observation groups were exposed to 1,2-DCE for 12 hr by continual static inhalation except control group. Dosage of exposure groups was 5.0, 10.0, 20.0 g/m(3) on sequence. That of after-exposure observation groups was 10.0 g/m(3). Rats of after-exposure observation groups were observed continually for 2,4,6 hr after exposure. The expression of N-methyl-D-aspartate receptor-1 (NMDAR1) was detected by immunohistochemical method.

RESULTSNMDAR1 stained neurons were mainly distributed at cerebral cortex and hippocampus. Compared with that of control group, the percentages of positive cells of NMDAR1 increased evidently at 10.0, 20.0 g/m(3) groups (P < 0.05). They were (18.33 +/- 1.86)%, (64.17 +/- 2.86)% at cerebral cortex, (15.5 +/- 1.87)%, (47.83 +/- 2.16)% at hippocampus. The percentages were also elevated obviously in 2, 4, 6 h after-exposure observation groups. They were (39.07 +/- 3.01)% (70.17 +/- 2.93)% (39.83 +/- 2.32)% at cerebral cortex, (16.30 +/- 1.03)% (19.80 +/- 1.17)% (16.50 +/- 1.05)% at hippocampus; Compared with that of 10.0 g/m(3) group, the percentages increased significantly only in 4 hr group at hippocampus.

CONCLUSIONThe overactivation of NMDAR1 is the main route by which excitatory amino acids chose to join the development of acute intoxicated encephalopathy induced by 1,2-DCE.

Animals ; Ethylene Dichlorides ; toxicity ; Female ; Hippocampus ; metabolism ; Male ; Neurotoxicity Syndromes ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, N-Methyl-D-Aspartate ; metabolism

3,4-Methylenedioxymethamphetamine (MDMA) is a substituted amphetamine with stimulating and hallucinogenic properties. Since MDMA induces "ecstasy" it is extensively used as a "recreational" drug. It has been well established that MDMA is neurotoxic and can result in long-term degeneration of cerebral 5-hydroxytryptamine (5-HT) nerve terminals in many species. The present study was undertaken to investigate the long-term neurotoxic effects of MDMA on cortical and hippocampal structures, by repeatedly administering MDMA in short time. Male Wistar rats were randomly assigned to control group and MDMA-treated group. MDMA (10 mg/kg) was administered to rats of MDMA-treated group, once per hour, total 40 mg/kg; rats of control group were treated with the same volume of saline. Thirty-two weeks after administering MDMA, the expression of serotonin transporter (SERT) mRNA and diazepam binding inhibitor (DBI) mRNA was detected by in situ hybridization. The expression of glial fibrillary acidic protein (GFAP) was detected by immunohistochemistry, and the degeneration of nerve terminals was demonstrated by Bielschowsky and Glee Marsland silver staining. The results showed that the expression of SERT mRNA in hippocampus decreased by 31.96%, while expression of DBI mRNA in neocortex increased by 40.51%, compared with the control group (P<0.05). The expression of GFAP in the brain tissue increased (P<0.05), while significant reduction of the nerve terminals in neocortex was demonstrated by silver staining, compared with the control group. These results suggest that the neurotoxicity of MDMA results in sustained cortical and hippocampal structural changes, which in turn result in disorder of the brain functions.
Animals ; Cerebral Cortex ; pathology ; physiopathology ; Diazepam Binding Inhibitor ; genetics ; metabolism ; Hippocampus ; pathology ; physiopathology ; Male ; N-Methyl-3,4-methylenedioxyamphetamine ; toxicity ; Neurotoxicity Syndromes ; etiology ; pathology ; physiopathology ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Wistar ; Serotonin Plasma Membrane Transport Proteins ; genetics ; metabolism

AIMTo explore IL-6 neuroprotection against glutamate-induced neurotoxicity and primary mechanisms involved in this neuroprotection.

METHODSThe cerebellar granule neurons from postnatal 8-day infant rats were chronically exposed to IL-6 for 8 days, and then glutamate stimulated the cultured cerebellar granule neurons for 15 min. Methyl-thiazole-tetrazolium (MTT) assay and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) method were used to observe the changes of neuronal vitality and apoptosis, respectively. Laser scanning confocal microscope (LSCM) and reverse transcription-polymerase chain reaction (RT-PCR) were respectively employed to measure dynamic changes of intracellular Ca2+ levels and expression of gp130 mRNA, a 130-kDa intracellular IL-6 signal-transduction protein, in the neurons.

RESULTSThe chronic IL-6 (2.5, 5 and 10 ng/ml) pretreatment of the cultured cerebellar granule neurons remarkably improved the decreased neuronal vitality by glutamate in a concentration-dependent manner. The neuronal apoptosis induced by glutamate was significantly attenuated by the chronic IL-6 pretreatment. The intracellular Ca2+ overload evoked by glutamate was also inhibited by the chronic IL-6 pretreatment. The expression of gp130 mRNA was dramatically lower in the IL-6-pretreated cerebellar granule neurons than in the IL-6-untreated neurons.

CONCLUSIONIL-6 can protect neurons against glutamate-induced exciting neurotoxicity. The mechanism of IL-6 neuroprotection may be closely related to the suppression of glutamate-induced intracellular Ca2+ overload and mediated by gp130 intracellular signal transduction pathways.

Animals ; Cells, Cultured ; Cerebellum ; cytology ; drug effects ; metabolism ; Glutamic Acid ; toxicity ; Interleukin-6 ; pharmacology ; Neurons ; drug effects ; metabolism ; Neuroprotective Agents ; pharmacology ; Neurotoxicity Syndromes ; metabolism ; Rats ; Rats, Sprague-Dawley