Ndufs4 ablation decreases synaptophysin expression in hippocampus.

Altered function of mitochondrial respiratory chain in brain cells is related to many neurodegenerative diseases. NADH Dehydrogenase (Ubiquinone) Fe-S protein 4 (Ndufs4) is one of the subunits of mitochondrial complex I and its mutation in human is associated with Leigh syndrome. However, the molecular biological role of Ndufs4 in neuronal function is poorly understood. In this study, upon Ndufs4 expression confirmation in NeuN-positive neurons, and GFAP-positive astrocytes in WT mouse hippocampus, we found significant decrease of mitochondrial respiration in Ndufs4-KO mouse hippocampus. Although there was no change in the number of NeuN positive neurons in Ndufs4-KO hippocampus, the expression of synaptophysin, a presynaptic protein, was significantly decreased. To investigate the detailed mechanism, we silenced Ndufs4 in Neuro-2a cells and we observed shorter neurite lengths with decreased expression of synaptophysin. Furthermore, western blot analysis for phosphorylated extracellular regulated kinase (pERK) revealed that Ndufs4 silencing decreases the activity of ERK signalling. These results suggest that Ndufs4-modulated mitochondrial activity may be involved in neuroplasticity via regulating synaptophysin expression.

Significance of chromogranin A and synaptophysin in medullary thyroid carcinoma.

Medullary thyroid carcinoma (MTC) is a relatively rare thyroid carcinoma of C-cell deviation and produces and secrete calcitonin (CT) and chromogranin A (CgA) into the blood. Thus, both CT and CgA are immunohistochemical and serum markers for MTCs. MTC occurs in both sporadic and inheritable cases and the hallmark of inheritable cases in multiple endocrine neoplasm 2 (NEN2) is MTC. MEN2 cases represent 30% of MTCs through germline RET protooncogene mutation and occur in younger ages involving bilateral thyroid lobes. Sporadic cases are 70% of cases of solitary tumor and occur in older ages. CgA and synaptophysin (SPY) are the two, most widely used and reliable immunohistochemical markers for neuroendocrine tumors including MTCs. This study aimed to detect different immunohistochemical staining patterns for CgA and SPY between non-symptomatic small, microscopic lesions and invading larger aggressive tumors in both MEA2 cases and sporadic cases. There was different CgA and SPY immunostaining in MEA2 cases where small tumors (≤ 0.3 cm) were lesser immunostained for CgA and SPY, despite strong staining for CT, compared to the larger (≥ 0.5cm) tumors, stronger immunostained for CgA. There was also different CgA and SPY immunohistochemical staining in sporadic cases between small lesion (≤ 0.5 cm) and larger tumors (≥ 1.0cm). One small sporadic tumor (0.5 x 0.3 cm) was strongly and weakly, patchy (about 10% of tumor tissue) stained for CgA and SPY, respectively, while larger sporadic tumors were diffusely, stronger stained for CgA and SPY. Therefore, stronger CgA and SPY immunostaining for larger tumors in both MEA2 and sporadic cases may be used as independent aggressive immunohistochemical markers for MTCs.

Neurotrophic isoindolinones from the fruiting bodies of Hericium erinaceus.

Four compounds, hericerin (1), isohericerinol A (2), N-de-phenylethyl isohericerin (3) and corallocin A (4) were isolated from the fruiting bodies of Hericium erinaceus, a lion's mane mushroom (Hericiaceae). Among them, isohericerinol A (2) was newly reported in nature. Further investigation of the neurotrophic effect of isolated compounds demonstrated that isohericerinol A (2) strongly increased the nerve growth factor (NGF) production in C6 glioma cells followed by corallocin A (4) and hericerin (1). Increased NGF production by these compounds promoted the neurite outgrowth in N2a neuronal cells. Western blot analysis also showed the increased protein expression of NGF, brain-derived neurotrophic factor (BDNF) and synaptophysin (SYP) in C6-N2a cells. Taken together, our present study characterized the neurotrophic constituents of H. erinaceus, which may support the potential use of memory improvement.

Composite Hemangioendothelioma With Neuroendocrine Marker Expression: Report of a "Paraganglioma-Like" Paravertebral Case.

Composite hemangioendothelioma is a rare vascular tumor morphologically comprising several distinct vascular components and exhibits a borderline malignant potential. We described the case of a 53-year-old female who presented with an infiltrative mass in the paravertebral soft tissue. The tumor showed discrete nests of synaptophysin-expressing epithelioid cells accompanied by rich vasculature, features highly reminiscent of sympathetic paraganglioma. Further analysis revealed areas resembling spindle cell hemangioma, retiform hemangioendothelioma, cavernous hemangioma/lymphangioma, and epithelioid hemangioendothelioma without the myxohyaline matrix in the tumor, and a final diagnosis of composite hemangioendothelioma with synaptophysin expression was made. Critical appraisal of this recently described entity and its possible pathogenic relationship with retiform hemangioendothelioma were discussed.

Expression of novel neuroendocrine marker insulinoma-associated protein 1 (INSM1) in genitourinary high-grade neuroendocrine carcinomas: An immunohistochemical study with specificity analysis and comparison to chromogranin, synaptophysin, and CD56.

Confirmation of genitourinary high-grade neuroendocrine carcinomas (GU-HGNECs) often requires immunohistochemical staining. Here we evaluated a novel neuroendocrine marker, insulinoma-associated protein 1 (INSM1), in GU-HGNECs with comparison to chromogranin, synaptophysin and CD56. Immunohistochemical expression of INSM1, chromogranin, synaptophysin, and CD56 was evaluated in 39 GU-HGNECs using full tissue sections [4 in kidney, 28 in urinary bladder, and 7 in prostate; 31 small cell carcinomas (SmCCs), 6 large cell neuroendocrine carcinomas (LCNECs), 2 mixed SmCC-LCNECs]. In 33 SmCCs/components, INSM1 showed similar sensitivity (93.9 %) to chromogranin (87.8 %), synaptophysin (93.9 %) and CD56 (87.8 %), and stained a similar percentage of tumor cells (52 %) to chromogranin (49 %) and CD56 (52 %), but lower than synaptophysin (87 %) (p < 0.0001). In 8 LCNECs/components, INSM1 is similar to chromogranin, synaptophysin or CD56 in sensitivity (62.5 %, 62.5 %, 75 %, 62.5 %, respectively) and the mean percentage of positively stained tumor cells (21 %, 44 %, 48 %, 37 %, respectively). INSM1 is more sensitive for SmCCs than LCNECs (93.9 % vs. 62.5 %, p = 0.015). INSM1 showed 97.4 % specificity upon analyzing 273 genitourinary non-neuroendocrine tumors on tissue microarrays. Our study indicates that INSM1 is a sensitive marker for genitourinary HGNECs with high specificity. For genitourinary SmCCs, INSM1 shows similar sensitivity to chromogranin, synaptophysin and CD56 but stains a lower percentage of tumor cells than synaptophysin. For genitourinary LCNECs, INSM1 showed similar sensitivity to chromogranin, synaptophysin and CD56. INSM1 is more sensitive for genitourinary SmCCs than LCNECs. Our result and literature review indicate that whether INSM1 is more sensitive than conventional neuroendocrine markers for HGNECs depends on the tumor primary sites.

Toll-like receptor 4 deficiency ameliorates ß2-microglobulin induced age-related cognition decline due to neuroinflammation in mice.

Toll-like receptor 4 (TLR4) is a crucial receptor in neuroinflammation and apoptotic neuronal death, and increasing evidences indicated that ß2-microglobulin (B2M) is thought to be a major contributor to age-related cognitive decline. In present study, we designed to investigate the effects of TLR4 on B2M-induced age-related cognitive decline. Wild-type (WT) C57BL/6, TLR4 knockout (TLR4 -KO) mice and hippocampal neurons from the two type mice were respectively divided into two groups: (1) Veh group; (2) B2M-treated group. The behavioral responses of mice were measured using Morris Water Maze. Hippocampal neurogenesis and neuronal damage, inflammatory response, apoptosis, synaptic proteins and neurotrophic factors, and TLR4/MyD88/NF-κB signaling pathway proteins were examined using molecular biological or histopathological methods. The results showed that WT mice received B2M in the DG exhibited age-related cognitive declines, increased TLR4 mRNA expression and high levels of interleukin-1ß (IL-1ß), tumor necrosis factor-alpha (TNF-α) and apoptotic neuronal death in the hippocampus, which were partially attenuated in TLR4-KO mice. Moreover, in absence of TLR4, B2M treatment improved hippocampus neurogenesis and increased synaptic related proteins. Our cell experiments further demonstrated that deletion of TLR4 could significantly increase synaptic related protein, decrease neuroinflammatory fators, inhibited apoptotic neuronal death, and regulated MyD88/NF-κB signal pathway after B2M treatment. In summary, our results support the TLR4 contributes to B2M-induced age-related cognitive decline due to neuroinflammation and apoptosis through TLR4/MyD88/NF-κB signaling pathway via a modulation of hippocampal neurogenesis and synaptic function. This may provide an important neuroprotective mechanism for improving age-related cognitive decline.

Possible involvement of DNA methylation in hippocampal synaptophysin gene expression during postnatal development of mice.

Synaptophysin (Syp) is an integral membrane protein of synaptic vesicles, and is ubiquitously expressed in neurons throughout the brain. As Syp expression is correlated with synaptogenesis during development of the central nervous system, the expression of Syp is considered to be a critical aspect of neuronal maturation and circuit formation. However, little information is available concerning the regulatory mechanisms of Syp gene expression during postnatal development of the brain. In the present study, we investigated changes in Syp mRNA in the hippocampus of mice during postnatal development, and examined the gene regulation mechanisms, focusing on DNA methylation. We found that hippocampal Syp expression involving both mRNA and protein levels increased during the first two weeks of life, and that this increase was accompanied by a transition from hypermethylation to hypomethylation at the CpG sites of the Syp gene upstream region. In addition, DNA demethylating agent 5-Aza-2'-deoxycytidine (5-aza-dC) de-repressed Syp gene expression both in vitro in Neuro-2a mouse neuronal cells and in vivo in the hippocampus of early postnatal mice. Furthermore, the methylation levels at upstream region of Syp gene in the hippocampus of developing mice was decreased by intraperitoneal injection of 5-aza-dC. These results suggest that Syp gene regulation, at least during postnatal brain development, could be mediated by DNA methylation. Our findings promote understanding of the molecular basis of synaptogenesis during postnatal brain development, and provide novel insight into therapeutic aspects of neurodevelopmental disorders involving synaptic dysfunction.

Insulinoma-associated Protein 1 (INSM1) in Thoracic Tumors is Less Sensitive but More Specific Compared With Synaptophysin, Chromogranin A, and CD56.

OBJECTIVE: Recognition of neuroendocrine differentiation is important for tumor classification and treatment stratification. To detect and confirm neuroendocrine differentiation, a combination of morphology and immunohistochemistry is often required. In this regard, synaptophysin, chromogranin A, and CD56 are established immunohistochemical markers. Insulinoma-associated protein 1 (INSM1) has been suggested as a novel stand-alone marker with the potential to replace the current standard panel. In this study, we compared the sensitivity and specificity of INSM1 and established markers. MATERIALS AND METHODS: A cohort of 493 lung tumors including 112 typical, 39 atypical carcinoids, 77 large cell neuroendocrine carcinomas, 144 small cell lung cancers, 30 thoracic paragangliomas, 47 adenocarcinomas, and 44 squamous cell carcinomas were selected and tissue microarrays were constructed. Synaptophysin, chromogranin A, CD56, and INSM1 were stained on all cases and evaluated manually as well as with an analysis software. Positivity was defined as ≥1% stained tumor cells in at least 1 of 2 cores per patient. RESULTS: INSM1 was positive in 305 of 402 tumors with expected neuroendocrine differentiation (typical and atypical carcinoids, large cell neuroendocrine carcinomas, small cell lung cancers, and paraganglioma; sensitivity: 76%). INSM1 was negative in all but 1 of 91 analyzed non-neuroendocrine tumors (adenocarcinomas, squamous cell carcinomas; specificity: 99%). All conventional markers, as well as their combination, had a higher sensitivity (97%) and a lower specificity (78%) for neuroendocrine differentiation compared with INSM1. CONCLUSIONS: Although INSM1 might be a meaningful adjunct in the differential diagnosis of neuroendocrine neoplasias, a general uncritical vote for replacing the traditional markers by INSM1 may not be justified.

Morphologic Spectrum of Neuroendocrine Tumors of the Prostate: An Updated Review.

CONTEXT.­: The incidence of neuroendocrine tumors of the prostate increases after hormonal therapy. Neuroendocrine tumors possess a broad spectrum of morphologic features and pose challenges in the pathologic diagnosis and clinical management of patients. OBJECTIVE.­: To present a brief updated summary of neuroendocrine tumors of the prostate with an overview of their histopathologic and immunohistochemical profiles and differential diagnoses. DATA SOURCES.­: Literature review, personal experience in the daily practice of pathologic diagnosis, and laboratory research. CONCLUSIONS.­: Our understanding of neuroendocrine tumors of the prostate classification and diagnosis continues to evolve. These advances benefit the risk stratification and management of prostate cancer.

Childhood adrenocortical tumor: A clinical and immunohistochemical study of 13 cases.

The aim of the study was to investigate the molecular mechanisms in childhood adrenocortical tumors (ACTs), which is still unclear.A total of 9 girls and 4 boys with ACTs were enrolled. Relevant clinical features were obtained from records. Immunohistochemistry of vimentin, chromogranin A, S100, synaptophysin, cytokeratin (CK), type 2 3ß-hydroxysteroid dehydrogenase (3ßHSD), cytochrome P45017α, p53, p21, p27, cyclin D1, Ki-67, insulin growth facter-2 (IGF-2), and ß-catenin were undertaken for 13 tumors and 3 adjacent normal tissues. TP53 mutations in exon 2-11 were analyzed for 6 tumors and 3 blood samples.Virilization was the most common presentation (8/13, 61.5%). Immunohistochemically, p53 was positive in 8 of 13 ACTs and none in controls while p21 was positive in 12 of 13 ACTs and none in controls (P = .0036). Ki-67 was positive in 10 of 13 ACTs, but not in normal tissues (P = .0089). Although the expression of p27, cyclin D1, IGF-2 and ß-catenin were similar between the ACTs and controls, ß-catenin was noted in nuclear of 3 ACTs but not in controls. The difference of type 2 3ßHSD and P450c17α was not significant (P > .05, respectively). Four variants of TP53 were identified in the 6 tumors. C215G variant was found in 5 of 6 while A701G and G743A variants were found in 1 case, respectively. A novel C680G variant was also noted in 1 case. It was notable that C215G variant was found in the blood mononuclear cell of 3 patients.In conclusion, p53 variant and p21 overexpression, and abnormal ß-catenin distribution may be involved in the etiology and mechanism of childhood ACTs.

Isoliquiritigenin attenuates lipopolysaccharide-induced cognitive impairment through antioxidant and anti-inflammatory activity.

BACKGROUND: Oxidative stress and neuroinflammation are central pathogenic mechanisms common to many neurological diseases. Isoliquiritigenin (ISL) is a flavonoid in licorice with multiple pharmacological properties, including anti-inflammatory activity, and has demonstrated protective efficacy against acute neural injury. However, potential actions against cognitive impairments have not been examined extensively. We established a rat model of cognitive impairment by intracerebroventricular injection of lipopolysaccharide (LPS), and examined the effects of ISL pretreatment on cognitive function, hippocampal injury, and hippocampal expression of various synaptic proteins, antioxidant enzymes, pro-inflammatory cytokines, and signaling factors controlling anti-oxidant and pro-inflammatory responses. RESULTS: Rats receiving LPS alone demonstrated spatial learning deficits in the Morris water maze test as evidenced by longer average escape latency, fewer platform crossings, and shorter average time in the target quadrant than untreated controls. ISL pretreatment reversed these deficits as well as LPS-induced decreases in the hippocampal expression levels of synaptophysin, postsynaptic density-95, brain-derived neurotrophic factor, superoxide dismutase, glutathione peroxidase, and BCL-2. ISL pretreatment also reversed LPS-induced increases in TUNEL-positive (apoptotic) cells, BAX/BCL-2 ratio, and expression levels of tumor necrosis factor-α, interleukin (IL)-1ß, IL-6, and C-C motif chemokine ligand 3. Pretreatment with ISL increased the expression levels of phosphorylated (p)-GSK-3ß, nuclear NRF2, HO-1 mRNA, and NQO1 mRNA, and reversed LPS-induced nuclear translocation of nuclear factor (NF)-κB. CONCLUSIONS: ISL protects against LPS-induced cognitive impairment and neuronal injury by promoting or maintaining antioxidant capacity and suppressing neuroinflammation, likely through phosphorylation-dependent inactivation of GSK-3ß, enhanced expression of NRF2-responsive antioxidant genes, and suppression of NF-κB-responsive pro-inflammatory genes.

Resveratrol and Metformin Recover Prefrontal Cortex AMPK Activation in Diet-Induced Obese Mice but Reduce BDNF and Synaptophysin Protein Content.

BACKGROUND: Obesity, insulin resistance, and type 2 diabetes are established risk factors for the development of Alzheimer's disease (AD). Given this connection, two drugs, metformin (MET) and resveratrol (RESV), are considered for the clearance of amyloid-ß peptides through AMPK-mediated activation of autophagy. However, overactivation of AMPK observed in late-stage AD brains and relationships between AMPK and neurogenesis (through mTORC1 inhibition), questions treatment with these drugs. OBJECTIVE: To examine if MET and/or RESV supplementation activates brain AMPK, regulates markers of autophagy, and affects markers of neuronal health/neurogenesis. METHODS: 8-week-old male C57BL/6J mice were fed a low (N = 12; 10% kcal fat; LFD) or high fat diet (N = 40; 60% kcal fat; HFD) for 9 weeks to induce insulin resistance and obesity. HFD mice were then treated with/without MET (250 mg/kg/day), RESV (100 mg/kg/day), or COMBO (MET: 250 mg/kg/day, RESV: 100 mg/kg/day) for 5 weeks. Hippocampus and prefrontal cortex were extracted for western blotting analysis. RESULTS: Cortex AMPK (T172) and raptor (S792, the regulatory subunit of mTORC1) phosphorylation were upregulated following RESV, COMBO treatments. mTOR (S2448) and ULK1 (S555) activation was seen following MET, COMBO and RESV, COMBO treatments, respectively, in the cortex and hippocampus. p62 content was decreased following RESV, COMBO, with LC3 content being increased following RESV treatment in the cortex. Brain derived neurotropic factor (BDNF) was significantly decreased following RESV, COMBO, and synaptophysin following all treatment in the cortex. CONCLUSION: These results demonstrate that while treatments upregulated markers of autophagy in the prefrontal cortex, reductions in neuronal health markers question the efficacy of AMPK as a therapy for AD.

Environmental enrichment restores the reduced expression of cerebellar synaptophysin and the motor coordination impairment in rats prenatally treated with betamethasone.

Preterm babies treated with synthetic glucocorticoids in utero exhibit behavioural alterations and disturbances in brain maturation during postnatal life. Accordingly, it has been shown in preclinical studies that SGC exposure at a clinical dose alters the presynaptic and postsynaptic structures and results in synaptic impairments. However, the precise mechanism by which SGC exposure impairs synaptic protein expression and its implications are not fully elucidated. Therefore, the purpose of this study was to investigate the effect of prenatal exposure to a clinical dose of betamethasone on the pre- and postsynaptic proteins expression in the developing rat cerebellum and prefrontal cortex, whose synchronized synaptic activity is crucial for motor control and learning. Consequently, the first objective of the present study was to determine whether prenatal betamethasone -equivalent to the clinically used dose- alters cerebellar vermal and cortical expression of synaptophysin, synaptotagmin I, post-synaptic density protein 95 and gephyrin - four important pre- and post-synaptic proteins, respectively- at a relevant adolescent stage. In addition, our second objective was to assess whether prenatal betamethasone administration induced coordination impairment using a rotarod test. On the other hand, it has been shown that the environmental enrichment is capable of improving synaptic transmission and recovering various behavioural impairments. Nevertheless, there is not enough information about the effect of this non-pharmacological preclinical approach on the regulation of this cerebellar and cortical synaptic proteins. Therefore, the third objective of this study was to examine whether environmental enrichment exposure could recover the possible molecular and behavioural impairments in the offspring at the same developmental stage. The principal data showed that adolescent rats prenatally treated with betamethasone exhibited underexpression of synaptophysin in the vermal cerebellum, but not change in levels of synaptotagmin I, post-synaptic density protein 95 and gephyrin. Analysis of the same pre- and post-synaptic proteins no showed differences in the frontal cortex of the same rats. These results were accompanied by an increase in the number of falls in the rotarod test, when the speed of rotation was fixed and when it was in acceleration, which means motor coordination impairments. Importantly, we found that environmental enrichment restores the betamethasone-induced reduction in the cerebellar synaptophysin together with a recover in the motor coordination impairments in prenatally betamethasone-exposed adolescent rats.

Effects of Transplanted Umbilical Cord Blood Mononuclear Cells Overexpressing GDNF on Spatial Memory and Hippocampal Synaptic Proteins in a Mouse Model of Alzheimer's Disease.

BACKGROUND/OBJECTIVE: Alzheimer's disease (AD) is a progressive incurable neurodegenerative disorder. Glial cell line-derived neurotrophic factor (GDNF) is a prominent regulator of brain tissue and has an impressive potential for use in AD therapy. While its metabolism is still not fully understood, delivering neuropeptides such as GDNF via umbilical cord blood mononuclear cells (UCBMCs) to the sites of neurodegeneration is a promising approach in the development of innovative therapeutic avenues. METHODS: UCBMCs were transduced with adenoviral vectors expressing GDNF and injected into AD transgenic mice. Various parameters including homing and survival of transplanted cells, expression of GDNF and synaptic proteins, as well as spatial memory were evaluated. RESULTS: UCBMCs were observed in the hippocampus and cortex several weeks after transplantation, and their long-term presence was associated with improved spatial memory. Post-synaptic density protein 95 (PSD-95) and synaptophysin levels in the hippocampus were also effectively restored following the procedure in AD mice. CONCLUSIONS: Our data indicate that gene-cell therapy with GDNF-overexpressing UCBMCs may produce long-lasting neuroprotection and stimulation of synaptogenesis. Such adenoviral constructs could potentially possess a high therapeutic potential for the treatment of AD.

Neuroplasticity-related correlates of environmental enrichment combined with physical activity differ between the sexes.

Environmental enrichment (EE), comprising positive physical (exercise) and cognitive stimuli, influences neuronal structure and usually improves brain function. The promise of EE as a preventative strategy against neuropsychiatric disease is especially high during early postnatal development when the brain is still amenable to reorganization. Despite the fact that male and female brains differ in terms of connectivity and function that may reflect early life experiences, knowledge of the neural substrates and mechanisms by which such changes arise remains limited. This study compared the impact of EE combined with physical activity on neuroplasticity and its functional consequences in adult male and female rats; EE was provided during the first 3 months of life and our analysis focused on the hippocampus, an area implicated in cognitive behavior as well as the neuroendocrine response to stress. Both male and female rats reared in EE displayed better object recognition memory than their control counterparts. Interestingly, sex differences were revealed in the effects of EE on time spent exploring the objects during this test. Independently of sex, EE increased hippocampal turnover rates of dopamine and serotonin and reduced expression of 5-HT1A receptors; in addition, EE upregulated expression of synaptophysin, a presynaptic protein, in the hippocampus. As compared to their respective controls, EE-exposed males exhibited parallel increases in phosphorylated Tau and the GluN2B receptor, whereas females responded to EE with reduced hippocampal levels of glutamate and GluN2B. Together, these observations provide further evidence on the differential effects of EE on markers of hippocampal neuroplasticity in males and females.

Immunohistochemical expression patterns of S100, synaptophysin, chromogranin A and neuron specific enolase in predicting malignant behaviour in paragangliomas.

PURPOSE: The purpose of this study was to evaluate the role of immunohistochemical markers in the prediction of malignancy in paragangliomas. METHODS: Our institute's patient records between 1990-2012 were retrieved in order to identify patients who were treated for paragangliomas. Size and location of the tumour, existence of concurrent metastatic disease, patient demographics and survival were recorded. Haematoxylin-eosin stained slides were reviewed and all tumours were stained specifically for neuron specific enolase (NSE), chromogranin, synaptophysin and S100 protein positivity. Positivity and expression patterns of the above markers were evaluated and compared between malignant and benign tumours. Malignant behaviour was defined when patient had concurrent or subsequent lymph node involvement, local recurrence and/or metastases. RESULTS: A total of 22 patients with a diagnosis of paraganglioma were treated in our institutes. Female to male ratio was 1.75: 1. The mean age was 43.5 and 51.6 years for women and men, respectively. In 5 patients the tumors had malignant clinical behavior. Their mean size was 3.65 cm for benign and 4.56 cm for malignant neoplasms. NSE expression was diffuse in 47.1% and 0% for benign and malignant tumors, respectively (p=0.10). S100 expression in the periphery of the tumour was typical in 88.2% and 0% for benign and malignant tumors, respectively (p<0.001). CONCLUSION: Immunohistochemical profile from the combination of NSE, synaptophysin chromogranin and S100 staining patterns can serve as a cheap and valuable tool for correctly distinguishing between malignant and benign paragangliomas with high diagnostic accuracy.

Docosahexaenoic acid protection in a rotenone induced Parkinson's model: Prevention of tubulin and synaptophysin loss, but no association with mitochondrial function.

Rotenone, a classic mitochondrial complex I inhibitor, leads to dopaminergic neuronal death resulting in a Parkinson's-like-disease. Docosahexaenoic acid (DHA) has shown neuroprotective effects in other experimental models of Parkinson's disease, but its effect on the rotenone-induced parkinsonism is still unknown. We tested whether DHA in vivo exerts a neuroprotective effect on rotenone-induced parkinsonism and explored the mechanisms involved, including mitochondrial function and ultrastructure as well as the expression of tubulin and synaptophysin. We pretreated eighty male Wistar rats with DHA (35 mg/kg/day) for seven days and then administered rotenone for eight days. We then measured rearing behavior, number of dopaminergic neurons, tyrosine hydroxylase content, tubulin and synaptophysin expression, mitochondrial complex I, respiratory control ratio, mitochondrial transmembrane potential, ATP production activity and mitochondrial ultrastructure. We found that in vivo DHA supply exerted a neuroprotective effect, evidenced by decreased dopaminergic neuron cell death. Although we detected rotenone induced mitochondrial ultrastructure alterations, these were not associated with mitochondrial dysfunction. Rotenone had no effect on mitochondrial complex I, respiratory control ratio, mitochondrial transmembrane potential or ATP production activity. DHA also prevented a rotenone-induced decrease in tubulin and synaptophysin expression. Our results support the neuroprotective effect of DHA on rotenone-induced parkinsonism, and a possible effect on early stage Parkinson's disease. This protective effect is not associated with mitochondrial function improvement, but rather with preventing loss of tubulin and synaptophysin, proteins relevant to synaptic transmission.

ERK1/2-mediated disruption of BDNF-TrkB signaling causes synaptic impairment contributing to fluoride-induced developmental neurotoxicity.

Excessive exposure to fluoride has adverse effects on neurodevelopment, but the mechanisms remain unclear. This study aimed to investigate the effects of fluoride exposure on synaptogenesis, and focused on the role of brain-derived neurotrophic factor (BDNF)-tyrosine kinase B (TrkB) signaling in these effects. Using Sprague-Dawley rats developmentally exposed to sodium fluoride (NaF) from pregnancy until 6 months of delivery as in vivo model, we showed that fluoride impaired the cognitive abilities of offspring rats, decreased the density of dendritic spines and the expression of synapse proteins synaptophysin (SYN) and postsynaptic density protein-95 (PSD-95) in hippocampus, suggesting fluoride-induced cognitive deficit associates with synaptic impairment. Consistently, NaF treatment reduced dendritic outgrowth and expression of SYN and PSD-95 in human neuroblastoma SH-SY5Y cells. Further studies demonstrated that the BDNF-TrkB axis was disrupted in vivo and in vitro, as manifested by BDNF accumulation and TrkB reduction. Importantly, fluoride treatment increased phospho-extracellular signal-regulated kinases 1 and 2 (p-ERK1/2) expression, while inhibition of p-ERK1/2 significantly attenuated the effects of NaF, indicating a regulating role of p-ERK1/2 in BDNF-TrkB signaling disruption. Collectively, these data suggest that the developmental neurotoxicity of fluoride is associated with the impairment of synaptogenesis, which is caused by ERK1/2-mediated BDNF-TrkB signaling disruption.

Expression of neuroendocrine differentiation markers in lethal metastatic castration-resistant prostate cancer.

Neuroendocrine differentiation (NED) is a common phenomenon in prostate cancer, and it has been associated with poor prognosis in some studies of primary prostate cancer. Incidence and patterns of NED in metastatic prostate cancer sites have not been examined widely. In this study, we studied expression of three commonly used markers of NED (chromogranin A, neuron specific enolase and synaptophysin) in 89 metastases from 31 men that died of castration-resistant prostate cancer and underwent rapid autopsy, and in 89 hormone-naïve primary tumors removed by radical prostatectomy. In addition, we examined NED association with androgen receptor, ERG and Ki-67 expression in metastatic tumor sites. Morphologically, 1 of 31 cases was classified as small cell carcinoma, and the remaining 30 were classified as usual prostate adenocarcinoma using a recently proposed classification of prostate cancers with NED. Metastases showed more expression of neuron specific enolase and synaptophysin compared to prostatectomies (6.3% of cells vs. 1.0%, p < 0.001 and 4.0% vs. 0.4%, p < 0.001, respectively). At least focal expression of one of the markers was seen in 78% of metastases. Strong expression was relatively uncommon, seen in 3/89 (chromogranin A), 8/89 (neuron specific enolase), and 5/89 (synaptophysin) metastases. Expression of chromogranin A and synaptophysin correlated with each other (r = 0.64, p < 0.001), but expression of neuron specific enolase did not correlate with the two other markers. Extent of NED varied significantly between different metastatic sites in individual patients. Absent androgen receptor expression was associated with strong expression of chromogranin A (p = .02) and neuron specific enolase (p = .02), but not with focal expression of any marker. No clear association was found between expression of NE markers and ERG or Ki-67. In conclusion, NED is a common and heterogeneous phenomenon in metastatic, castration-resistant prostate cancer. NED is more often present in castration-resistant prostate cancer compared to hormone-naïve disease, and it is associated with androgen receptor negativity. More research is needed to understand significance of NED in the progression of prostate cancer.