Effects of chronic fluorosis on the brain.

This article reviews the effects of chronic fluorosis on the brain and possible mechanisms. We used PubMed, Medline and Cochraine databases to collect data on fluorosis, brain injury, and pathogenesis. A large number of in vivo and in vitro studies and epidemiological investigations have found that chronic fluorosis can cause brain damage, resulting in abnormal brain structure and brain function.Chronic fluorosis not only causes a decline in concentration, learning, and memory, but also has mental symptoms such as anxiety, tension, and depression. Several possible mechanisms that have been proposed: the oxidative stress and inflammation theory, neural cell apoptosis theory, neurotransmitter imbalance theory, as well as the doctrine of the interaction of fluorine with other elements. However, the specific mechanism of chronic fluorosis on brain damage is still unclear. Thus, a better understanding of the mechanisms via which chronic fluorosis causes brain damage is of great significance to protect the physical and mental health of people in developing countries, especially those living in the endemic areas of fluorosis. In brief, further investigation concerning the influence of fluoride on the brain should be conducted as the neural damage induced by it may bring about a huge problem in public health, especially considering growing environmental pollution.

The cognitive impairment and risk factors of the older people living in high fluorosis areas: DKK1 need attention.

OBJECTIVE: To evaluate cognitive impairment and risk factors of elders in high fluoride drinking water areas and investigate whether DKK1 is involved in this disorder. METHODS: MoCA-B and AD-8 were used to measure the cognitive functions of 272 and 172 subjects over the age of 60 came from the high and normal fluoride drinking water areas respectively, general information and peripheral blood were collected, the level of SOD, GSH and MDA were measured, mRNA level of DKK1, the concentration of blood fluoride and the polymorphism of APOE were tested. RESULTS: The blood fluoride concentration, mRNA level of DKK1 and ratio of abnormal cognitive function of subjects in high fluorine drinking water areas were higher than those in normal areas. The level of SOD of subjects in high fluorine drinking water was low compared with those in normal areas. The level of MDA and GSH had no difference between the two crowds in different fluorine drinking water areas. There were differences in cigarette smoking, education, dental status, hypertension, hyperlipidaemia and APOE results between the two crowds in different fluorine drinking water areas. The mRNA level of DKK1 and the level of cognitive function showed a positive correlation and DKK1 was one of five risk factors involved in cognitive impairment of older people living in high fluorosis areas. CONCLUSIONS: The cognitive functions could be impaired in the older people living in high fluoride drinking water areas, and DKK1 may as a potential intervention point of this brain damage process need attention.

Attenuation of hyperalgesia responses via the modulation of 5-hydroxytryptamine signalings in the rostral ventromedial medulla and spinal cord in a 6-hydroxydopamine-induced rat model of Parkinson's disease.

Background Although pain is one of the most distressing non-motor symptoms among patients with Parkinson's disease, the underlying mechanisms of pain in Parkinson's disease remain elusive. The aim of the present study was to investigate the role of serotonin (5-hydroxytryptamine) in the rostral ventromedial medulla (RVM) and spinal cord in pain sensory abnormalities in a 6-hydroxydopamine-treated rat model of Parkinson's disease. Methods The rotarod test was used to evaluate motor function. The radiant heat test and von Frey test were conducted to evaluate thermal and mechanical pain thresholds, respectively. Immunofluorescence was used to examine 5-hydroxytryptamine neurons and fibers in the rostral ventromedial medulla and spinal cord. High-performance liquid chromatography was used to determine 5-hydroxytryptamine and 5-hydroxyindoleacetic acid levels. Results The duration of running time on the rotarod test was significantly reduced in 6-hydroxydopamine-treated rats. Nociceptive thresholds of both mechanical and heat pain were reduced compared to sham-treated rats. In addition to the degeneration of cell bodies and fibers in the substantia nigra pars compacta, the number of rostral ventromedial medulla 5-hydroxytryptamine neurons and 5-hydroxytryptamine fibers in the spinal dorsal horn was dramatically decreased. 5-Hydroxytryptamine concentrations in both the rostral ventromedial medulla and spinal cord were reduced. Furthermore, the administration of citalopram significantly attenuated pain hypersensitivity. Interestingly, Intra-rostral ventromedial medulla (intra-RVM) microinjection of 5,7-dihydroxytryptamine partially reversed pain hypersensitivity of 6-hydroxydopamine-treated rats. Conclusions These results suggest that the decreased 5-hydroxytryptamine contents in the rostral ventromedial medulla and spinal dorsal horn may be involved in hyperalgesia in the 6-hydroxydopamine-induced rat model of Parkinson's disease.

EGb-761 Attenuates the Anti-proliferative Activity of Fluoride via DDK1 in PC-12 Cells.

EGb-761 is commonly used as a treatment for ischemic brain injury, neurodegenerative diseases and some types of tumors (Christen and Maixent, in Cell Mol Biol 48(6):601-611, 2002). However, it is unclear whether EGb-761 affects the proliferation of cells exposed to fluoride. In this study, the proliferation and apoptosis of PC-12 cells exposed to fluoride were investigated and EGb-761 was used to protect PC-12 cells against the effects of fluoride. We found that the canonical Wnt signaling pathway was involved in the anti-proliferation of PC-12 cells exposed to fluoride. Furthermore, the results also showed that EGb-761 could attenuate the anti-proliferative activity of fluoride via DDK1 in PC-12 cells. This study may provide a new method for protecting against the inhibition of cell proliferation induced by fluoride.

Neuroprotective Effects of Paeoniflorin on 6-OHDA-Lesioned Rat Model of Parkinson's Disease.

Paeoniflorin (PF) is the main active component extracted from the roots of Paeonialactiflora, a traditional Chinese medicine used for the treatment of neurodegenerative disorders, especially Parkinson's disease (PD). The degeneration of dopaminergic (DA-) neurons in PD may be caused by pathological activation of acid-sensing ion channels (ASICs). Thus, we designed a series of experiments to evaluate the therapeutic effects of PF and to test whether its effects are related to its inhibitory effect on ASIC1a. We found that systemic administration of PF or ASICs blockers (psalmotoxin-1 and amiloride) improved behavioral symptoms, delayed DA-neuronal loss and attenuated the reduction of dopamine (DA) and its metabolites in a rat model of 6-hydroxydopamine (6-OHDA)-induced PD. In addition, our data showed that PF, like ASICs blockers, regulated the expression of ASIC1a, decreased the level of α-synuclein (α-SYN), and improved autophagic dysfunction. Further experiments showed that ASIC1a knockdown down-regulated the α-SYN level and alleviated the autophagic injury in the 6-OHDA-treated ASIC1a-silenced PC12 cells. In summary, these findings indicate that PF enhanced the autophagic degradation of α-SYN and, thus, protected DA-neurons against the neurotoxicity caused by 6-OHDA. These findings also provide experimental evidence that PF may be a neuroprotectant for PD by acting on ASIC1a and that ASIC1a may be involved in the pathogenesis of PD.

Adolescent's anhedonia and association with childhood trauma among Chinese adolescents: a cross-sectional study.

OBJECTIVES: To estimate the level of anhedonia among adolescents and explore the association between anhedonia and childhood trauma (CT). DESIGN: A stratified random cluster sample of adolescents participated in a survey, which included three questionnaires: Snaith-Pamilton Pleasure Scale, Childhood Trauma Questionnaire and Patient Health Questionnaire-9. SETTING: The study was conducted in 60 classes in 10 primary, middle and high schools in five economically developed cities along the Southeast Coast of China from April to October 2022. PARTICIPANTS: One thousand seven hundred and forty-five adolescents with ages ranging from 9 to 18 years participated in the study. PRIMARY AND SECONDARY OUTCOMES: The primary outcome was the level of anhedonia, CT and depression among adolescents. The association between anhedonia and CT was determined. RESULTS: The mean scores of anhedonia, CT and depression were 24.88 (6.18), 36.75 (8.87) and 4.46 (5.36), respectively. Anhedonia scores of boys (24.24±6.12) and girls (25.62±6.16) were different (t=-4.69, p<0.01). After controlling for sex, age, the presence of siblings and depression, CT was associated with adolescent anhedonia. Emotional abuse (ß=0.14), emotional neglect (ß=0.15) and physical neglect (ß=0.10) positively predicted adolescent anhedonia (p<0.01), whereas physical abuse negatively predicted adolescent anhedonia (ß=-0.07, p<0.01). Sex had a moderating effect on the relationship between adolescent anhedonia and emotional neglect during childhood, and the negative effect of emotional neglect on adolescent anhedonia in girls was greater than in boys. CONCLUSIONS: CT, including emotional abuse, physical abuse, emotional neglect, and physical neglect, was an independent predictor of adolescents' ability to experience pleasure in daily life. Therefore, awareness of CT should be promoted. Emotional neglect had a more severe effect on anhedonia among girls than among boys, suggesting that emotional neglect should be paid much attention among girls.

A compendious summary of Parkinson's disease patient-derived iPSCs in the first decade.

The number of Parkinson's disease (PD) patients increases with aging, which brings heavy burden to families and society. The emergence of patient-derived induced pluripotent stem cells (iPSCs) has brought hope to the current situation of lacking new breakthroughs in diagnosis and treatment of PD. In this article, we reviewed and analyzed the current researches related to PD patient-derived iPSCs, in order to provide solid theoretical basis for future study of PD. In 2008, successful iPSCs derived from PD patients were reported. The current iPSCs research in PD mostly focused on the establishment of specific iPSCs models of PD patients carrying susceptible genes. The main source of PD patient-derived iPSCs is skin fibroblasts and the mainstream reprogramming methodology is the mature "four-factor" method, which introduces four totipotent correlation factors Oct4, Sox2, Klf4 and c-Myc into somatic cells. The main sources of iPSCs are patients with non-pedigrees and there have been no studies involving both PD patients and unaffected carriers within the same family. Most of the existing studies of PD patient-derived iPSCs started with the induction method for obtaining dopaminergic neurons in the first instance, but therapeutic applications are being increased. Although it is not the ultimate panacea, and there are still some unsolved problems (e.g., whether the mutated genes should be corrected or not), a better understanding of iPSCs may be a good gift for both PD patients and doctors due to their advantages in diagnosis and treatment of PD.

Effects of Ginkgo biloba extract EGb761 on neural differentiation of stem cells offer new hope for neurological disease treatment.

Stem cell transplantation has brought new hope for the treatment of neurological diseases. The key to stem cell therapy lies in inducing the specific differentiation of stem cells into nerve cells. Because the differentiation of stem cells in vitro and in vivo is affected by multiple factors, the final differentiation outcome is strongly associated with the microenvironment in which the stem cells are located. Accordingly, the optimal microenvironment for inducing stem cell differentiation is a hot topic. EGb761 is extracted from the leaves of the Ginkgo biloba tree. It is used worldwide and is becoming one of the focuses of stem cell research. Studies have shown that EGb761 can antagonize oxygen free radicals, stabilize cell membranes, promote neurogenesis and synaptogenesis, increase the level of brain-derived neurotrophic factors, and replicate the environment required during the differentiation of stem cells into nerve cells. This offers the possibility of using EGb761 to induce the differentiation of stem cells, facilitating stem cell transplantation. To provide a comprehensive reference for the future application of EGb761 in stem cell therapy, we reviewed studies investigating the influence of EGb761 on stem cells. These started with the composition and neuropharmacology of EGb761, and eventually led to the finding that EGb761 and some of its important components play important roles in the differentiation of stem cells and the protection of a beneficial microenvironment for stem cell transplantation.

Fluoride Induces Neuroinflammation and Alters Wnt Signaling Pathway in BV2 Microglial Cells.

Fluoride is a common element in nature and our daily life, and excessive intake of this element can cause fluorosis and irreversible brain damage. The toxic effects of fluoride on the central nervous system may be attributed to the release of inflammatory cytokines and ROS. GSK3ß is a key protein that modulates NF-κB activity and inflammatory cytokine levels and plays an important role in the Wnt signaling pathway. In this study, we found that fluoride altered the inflammatory status and oxidative stress by inhibiting Wnt signaling pathway activity. This study thus provides a valid basis for the fluorine-induced neuroinflammation injury theory.

eIF3a improve cisplatin sensitivity in ovarian cancer by regulating XPC and p27Kip1 translation.

The eukaryotic translation initiation factor 3a (eIF3a) is one of the core subunits of the translation initiation complex eIF3, responsible for ribosomal subunit joining and mRNA recruitment to the ribosome. Our previous study identified that it was correlated with platinum response in lung cancer. The current study aims to test the hypothesis that eIF3a may affect the drug response and prognosis of ovarian cancer patients receiving platinum-based chemotherapy by regulating xeroderma pigmentosum complementation group C (XPC) and p27(Kip1). Immunohistochemistry and western blot was used to determine the expression of eIF3a in 126 human ovarian cancer tissues followed by association analysis of eIF3a expression with patient's response and survival. Ectopic over-expression and RNA interference knockdown of eIF3a were carried out in A2780/cisplatin (DDP) and its parental A2780 cells, respectively, to determine the effect of altered eIF3a expression on cellular response to cisplatin by employing MTT assay. Western Blot analyses were also carried out to determine the regulation of eIF3a on XPC and p27(Kip1). eIF3a expression was associated with response of ovarian cancer patients to DDP-based chemotherapy and their survival. Overexpression and knockdown of eIF3a increased and decreased the cellular response to cisplatin in A2780/DDP and A2780 cells, respectively. In addition, XPC and p27(Kip1) were down regulated by eIF3a. eIF3a improves ovarian cancer patients' response to DDP-based chemotherapy via down regulating XPC and p27(Kip1).

Antidepressant-like effects of auraptenol in mice.

Depression is a major psychiatric disorder affecting nearly 21% of the world population and imposes a substantial health burden on society. Current available antidepressants are not adequate to meet the clinical needs. Here we report that auraptenol, an active component of the traditional Chinese medicine, angelicae dahuricae radix, had antidepressant-like effects in mice models of depression. In mouse forced swimming test and tail suspension test, two validated models of depression, auraptenol dose-dependently decreased the immobility duration within the dose range of 0.05-0.4 mg/kg. In addition, the antidepressant-like effects of auraptenol was significantly averted by a selective serotonin 5-HT1A receptor antagonist WAY100635 (1 mg/kg). These doses that affected the immobile response did not affect locomotor activity. In summary, this study for the first time identified an active component from the herbal medicine angelicae dahuricae radix that possesses robust antidepressant-like efficacy in mice. These data support further exploration for the possibility of developing auraptenol as a novel antidepressant agent in the treatment of major depression disorders.

[Staging treatment for complex tibial metaphyseal fractures with external fixator].

OBJECTIVE: To observe the clinical effects of combined type external fixator in treating complex tibial metaphyseal fractures. METHODS: From January 2007 to July 2012, 34 patients with complex tibial metaphyseal fractures were treated with combined type external fixator in different stagings. There were 23 males and 11 females, with a mean age of 41.3 years (ranged, 16 to 63), and the course of disease were from 1 h to 8 d. In the patients, 31 cases were open fractures, 11 cases with type II, 13 cases with type III A, 7 cases with type III B according with Gustilo classification; 19 cases were tibia plateau fractures, 6 cases with type II, 1 case with type IV, 5 cases with type V, 7 cases with type VI according to Schatzker classification; 15 cases were distal tibial fractures (one were bilateral fractures), 2 fractures with type A2, 1 fracture with type A3, 1 fracture with type C1, 5 fractures with type C2, 7 fractures with type C3 according to AO classification. Rasmussensn scoring system and AOFAS Ankle Hind-foot Scale were respectively used to assess the joint function of knee and hip. RESULTS: Wound surface of 19 patients obtained at phase I healing and 15 patients obtained at phase III healing. Superficial wound infections occurred in 2 cases and bone non-union necessitated reoperation occurred in 2 cases (final fractures obtained bone healing after the second operation). All patients were followed up from 6 to 38 months with a mean of 14.3 months. At the final follow-up,according to Rasmussensn scoring system, 5 fractures got excellent results, 11 good, 3 fair, the mean Rasmussen score was 23.58 +/- 3.98; according to AOFAS Ankle Hind-foot Scale, 5 fractures got excellent results, 8 good, 3 fair, the mean AOFAS Ankle Hind -foot Scale was 80.75 +/- 14.21. CONCLUSION: Combined type external fixator can well maintain the stability of the fractures, had advantages of low incidences of soft tissue complications and less influence to joint motion in treatment of complicated tibial metaphyseal fractures. However there were some limitations in long-term use.