Neuronal nuclear antigen (NeuN): a useful marker of neuronal immaturity in sudden unexplained perinatal death

Healthy Plasma Exosomes Exert Potential Neuroprotective Effects against Methylmalonic Acid-Induced Hippocampal Neuron Injury

Exosomes have shown good potential for alleviating neurological deficits and delaying memory deterioration, but the neuroprotective effects of exosomes remain unknown. Methylmalonic acidemia is a metabolic disorder characterized by the accumulation of methylmalonic acid (MMA) in various tissues that inhibits neuronal survival and function, leading to accelerated neurological deterioration. Effective therapies to mitigate these symptoms are lacking. The purpose of this study was to explore the neuroprotective effects of plasma exosomes on cells and a mouse model of MMA-induced injury. We evaluated the ability of plasma exosomes to reduce the neuronal apoptosis, cross the blood-brain barrier, and affect various parameters related to neuronal function. MMA promoted cell apoptosis, disrupted the metabolic balance, and altered the expression of B-cell lymphoma-2 (Bcl-2), Bcl2-associated X (Bax), and synaptophysin-1 (Syp-1), and these changes may be involved in MMA-induced neuronal apoptosis. Additionally, plasma exosomes normalized learning and memory and protected against MMA-induced neuronal apoptosis. Our findings indicate that neurological deficits are linked to the pathogenesis of methylmalonic acidemia, and healthy plasma exosomes may exert neuroprotective and therapeutic effects by altering the expression of exosomal microRNAs, facilitating neuronal functional recovery in the context of this inherited metabolic disease. Intravenous plasma-derived exosome treatment may be a novel clinical therapeutic strategy for methylmalonic acidemia.

The leachate from the Urban Solid Waste Transfer Station produces neurotoxicity in Wistar rats

Leachate from municipal solid waste is a mixture of xenobiotics capable of contaminating bodies of water and causing damage to the health of living beings that inhabit or consume contaminated water. A previous study revealed the presence of heavy metals in Urban Solid Waste Transfer Station (USWTS) leachate above the permissible national and international limits. In the present study, we demonstrate that subchronic oral administration (5 and 25 % v/v) of leachate to male Wistar rats caused changes in the immunoreactivity of the glial markers: GFAP and Iba-1, accompanied by an increase in the expression of caspase-3, and a decrease in the expression of the NeuN protein. Results indicate that the heavy metals present in the leachate induced neuronal loss in the prefrontal cortex, suggesting that these contaminants can cause neurological problems in mammals that consume surface water with xenobiotics, since the leachate could contaminate water bodies and underground water.

Naringenin mitigates aluminum toxicity-induced learning memory impairments and neurodegeneration through amelioration of oxidative stress

Aluminum chloride (AlCl3) is a potent neurotoxic substance known to cause memory impairment and oxidative stress-dependent neurodegeneration. Naringenin (NAR) is a dietary flavonoid with potent antioxidant and anti-inflammatory properties which was implemented against AlCl3-induced neurotoxicity to ascertain its neuroprotective efficacy. Experimental neurotoxicity in mice was induced by exposure of AlCl3 (10 mg/kg, p.o.) followed by treatment with NAR (10 mg/kg, p.o.) for a total of 63 days. Assessed the morphometric, learning memory dysfunction (novel object recognition, T- and Y-maze tests), neuronal oxidative stress, and histopathological alteration in different regions of the brain, mainly cortex, hippocampus, thalamus, and cerebellum. AlCl3 significantly suppressed the spatial learning and memory power which were notably improved by administration of NAR. The levels of oxidative stress parameters nitric oxide, advanced oxidation of protein products, protein carbonylation, lipid peroxidation, superoxide dismutase, catalase, glutathione reductase, reduced glutathione, and the activity of acetylcholine esterase were altered 1.5-3 folds by AlCl3 significantly. Treatment of NAR remarkably restored the level of oxidative stress parameters and maintained the antioxidant defense system. AlCl3 suppressed the expression of neuronal proliferation marker NeuN that was restored by NAR treatment which may be a plausible mechanism. NAR showed therapeutic efficacy as a natural supplement against aluminum-intoxicated memory impairments and histopathological alteration through a mechanism involving an antioxidant defense system and neuronal proliferation.

Caffeic acid protects against l-methionine induced reduction in neurogenesis and cognitive impairment in a rat model

l-methionine (L-met) is a substantial non-polar amino acid for normal development. L-met is converted to homocysteine that leads to hyperhomocysteinemia and subsequent excessive homocysteine in serum resulting in stimulating oxidative stress and vascular dementia. Several studies have found that hyperhomocysteine causes neuronal cell damage, which leads to memory impairment. Caffeic acid is a substrate in phenolic compound discovered in plant biosynthesis. Caffeic acid contains biological antioxidant and neuroprotective properties. The neuroprotective reaction of caffeic acid can protect against the brain disruption from hydrogen peroxide produced by oxidative stress. It also enhances GSH and superoxide dismutase activities, which protect against neuron cell loss caused by oxidative stress in the hippocampus. Hence, we investigated the protective role of caffeic acid in hippocampal neurogenesis and cognitive impairment induced by L-met in rats. Six groups of Sprague Dawley rats were assigned including control, L-met (1.7 g/kg/day), caffeic acid (20, 40 mg/kg), and L-met + caffeic acid (20, 40 mg/kg) groups. Spatial and recognition memories were subsequently examined using novel object location (NOL) and novel object recognition (NOR) tests. Moreover, the immunofluorescence technique was performed to detect Ki-67/RECA-1, bromodeoxyuridine (BrdU)/NeuN and p21 markers to represent hippocampal neurogenesis changes. The results revealed decreases in vasculature related cell proliferation and neuronal cell survival. By contrast, cell cycle arrest was increased in the L-met group. These results showed the association of the spatial and recognition memory impairments. However, the deterioration can be restored by co-administration with caffeic acid.

Analysis of the interplay between MeCP2 and histone H1 during in vitro differentiation of human ReNCell neural progenitor cells

An immortalized neural cell line derived from the human ventral mesencephalon, called ReNCell, and its MeCP2 knock out were used. With it, we characterized the chromatin compositional transitions undergone during differentiation, with special emphasis on linker histones. While the WT cells displayed the development of dendrites and axons the KO cells did not, despite undergoing differentiation as monitored by NeuN. ReNCell expressed minimal amounts of histone H1.0 and their linker histone complement consisted mainly of histone H1.2, H1.4 and H1.5. The overall level of histone H1 exhibited a trend to increase during the differentiation of MeCP2 KO cells. The phosphorylation levels of histone H1 proteins decreased dramatically during ReNCell's cell differentiation independently of the presence of MeCP2. Immunofluorescence analysis showed that MeCP2 exhibits an extensive co-localization with linker histones. Interestingly, the average size of the nucleus decreased during differentiation but in the MeCP2 KO cells, the smaller size of the nuclei at the start of differentiation increased by almost 40% after differentiation by 8 days (8 DIV). In summary, our data provide a compelling perspective on the dynamic changes of H1 histones during neural differentiation, coupled with the intricate interplay between H1 variants and MeCP2.Abbreviations: ACN, acetonitrile; A230, absorbance at 230 nm; bFGF, basic fibroblast growth factor; CM, chicken erythrocyte histone marker; CNS, central nervous system; CRISPR, clustered regulated interspaced short palindromic repeatsDAPI, 4,'6-diaminidino-2-phenylindole; DIV, days in vitro (days after differentiation is induced); DMEM, Dulbecco's modified Eagle medium; EGF, epidermal growth factor; ESC, embryonic stem cell; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; GFAP, glial fibrillary acidic proteinHPLC, high-performance liquid chromatography; IF, immunofluorescence; iPSCs, induced pluripotent stem cells; MAP2, microtubule-associated protein 2; MBD, methyl-binding domain; MeCP2, methyl-CpG binding protein 2; MS, mass spectrometry; NCP, nucleosome core particle; NeuN, neuron nuclear antigen; NPC, neural progenitor cellPAGE, polyacrylamide gel electrophoresis; PBS, phosphate buffered saline; PFA, paraformaldehyde; PTM, posttranslational modification; RP-HPLC, reversed phase HPLC; ReNCells, ReNCells VM; RPLP0, ribosomal protein lateral stalk subunit P0; RT-qPCR, reverse transcription quantitative polymerase-chain reaction; RTT, Rett Syndrome; SDS, sodium dodecyl sulphate; TAD, topologically associating domain; Triple KO, triple knockout.

Development of neurochemical labeling in the intermediolateral nucleus of cats' spinal cord

NeuN is a neuron-specific nuclear protein expressed in most mature neuronal cell types, with some exceptions. These exceptions are known mainly for the brain but not for the spinal cord or the spinal visceral networks for which only scarce information is available. One of the most defined visceral structures in the spinal cord is the sympathetic intermediolateral nucleus located within the thoracolumbar segments. We investigated the NeuN staining in the intermediolateral nucleus and compared it with the staining for two neurochemical markers of visceral neurons: nitric oxide synthase and calcium-binding protein calretinin in adult cats and in kittens aged 0, 14, and 35 days. A clear NeuN-immunonegativity was obtained for intermediolateral neurons labeled for nitric oxide synthase for both adult cats and kittens. In contrast, a matched immunopositivity for the NeuN and calretinin was obtained, showing an age-dependent degree of this colocalization, which was high in newborn kittens, decreased on postnatal 14 and 35 days and persisted at a moderate level up to adulthood. Perhaps our data displayed a heterogeneity of the intermediolateral neurons.

The Differential Diagnosis of Congenital Developmental Midline Nasal Masses: Histopathological, Clinical, and Radiological Aspects

Developmental midline nasal masses including nasal dermoids (NDs), encephaloceles (EPHCs), and nasal glial heterotopias (NGHs) are a consequence of disrupted embryonal developmental processes in the frontonasal region. Surgery is the only method of treatment in order to prevent local and intracranial inflammatory complications as well as distant deformities of the facial skeleton. Due to their rarity, similar location, and clinical and radiological symptoms, meticulous preoperative differential diagnostics is mandatory. The aim of this thorough literature review was to present and discuss all clinical, histopathological, and radiological aspects of NDs, NGHs, and EPHCs that are crucial for their differential diagnosis.

Calcium Phosphate-Based Nanoformulation Selectively Abolishes Phenytoin Resistance in Epileptic Neurons for Ceasing Seizures

Phenytoin (PHT) is a first-line antiepileptic drug in clinics, which could decrease neuronal bioelectric activity by blocking the voltage-operated sodium channels. However, the intrinsically low blood-brain-barrier (BBB)-crossing capability of PHT and upregulated expression level of the efflux transporter p-glycoprotein (P-gp) coded by the gene Abcb1 in epileptic neurons limit its efficacy in vivo. Herein, a nanointegrated strategy to overcome PHT resistance mechanisms for enhanced antiepileptic efficacy is reported. Specifically, PHT is first incorporated into calcium phosphate (CaP) nanoparticles through biomineralization, followed by the surface modification of the PEGylated BBB-penetrating TAT peptide. The CaP@PHT-PEG-TAT nanoformulation could effectively cross the BBB to be taken in by epileptic neurons. Afterward, the acidic lysosomal environment would trigger their complete degradation to release Ca²⁺ and PHT into the cytosol. Ca²⁺ ions would inhibit mitochondrial oxidative phosphorylation to reverse cellular hypoxia to block hypoxia-inducible factor-1α (Hif1α)-Abcb1-axis, as well as disrupt adenosine triphosphate generation, leading to simultaneous suppression of the expression and drug efflux capacity of P-gp to enhance PHT retention. This study offers an approach for effective therapeutic intervention against drug-resistant epilepsy.

Fetal Brain Damage in Human Fetuses with Congenital Cytomegalovirus Infection: Histological Features and Viral Tropism

Human cytomegalovirus (HCMV) causes congenital neurological lifelong disabilities. To date, the neuropathogenesis of brain injury related to congenital HCMV (cCMV) infection is poorly understood. This study evaluates the characteristics and pathogenetic mechanisms of encephalic damage in cCMV infection. Ten HCMV-infected human fetuses at 21 weeks of gestation were examined. Specifically, tissues from different brain areas were analyzed by: (i) immunohistochemistry (IHC) to detect HCMV-infected cell distribution, (ii) hematoxylin-eosin staining to evaluate histological damage and (iii) real-time PCR to quantify tissue viral load (HCMV-DNA). The differentiation stage of HCMV-infected neural/neuronal cells was assessed by double IHC to detect simultaneously HCMV-antigens and neural/neuronal markers: nestin (a marker of neural stem/progenitor cells), doublecortin (DCX, marker of cells committed to the neuronal lineage) and neuronal nuclei (NeuN, identifying mature neurons). HCMV-positive cells and viral DNA were found in the brain of 8/10 (80%) fetuses. For these cases, brain damage was classified as mild (n = 4, 50%), moderate (n = 3, 37.5%) and severe (n = 1, 12.5%) based on presence and frequency of pathological findings (necrosis, microglial nodules, microglial activation, astrocytosis, and vascular changes). The highest median HCMV-DNA level was found in the hippocampus (212 copies/5 ng of human DNA [hDNA], range: 10-7,505) as well as the highest mean HCMV-infected cell value (2.9 cells, range: 0-23), followed by that detected in subventricular zone (1.7 cells, range: 0-19). These findings suggested a preferential viral tropism for both neural stem/progenitor cells and neuronal committed cells, residing in these regions, confirmed by the expression of DCX and nestin in 94% and 63.3% of HCMV-positive cells, respectively. NeuN was not found among HCMV-positive cells and was nearly absent in the brain with severe damage, suggesting HCMV does not infect mature neurons and immature neural/neuronal cells do not differentiate into neurons. This could lead to known structural and functional brain defects from cCMV infection.

PDIA3 Expression Is Altered in the Limbic Brain Regions of Triple-Transgenic Mouse Model of Alzheimer's Disease

In the present study, we used a mouse model of Alzheimer's disease (AD) (3×Tg-AD mice) to longitudinally analyse the expression level of PDIA3, a protein disulfide isomerase and endoplasmic reticulum (ER) chaperone, in selected brain limbic areas strongly affected by AD-pathology (amygdala, entorhinal cortex, dorsal and ventral hippocampus). Our results suggest that, while in Non-Tg mice PDIA3 levels gradually reduce with aging in all brain regions analyzed, 3×Tg-AD mice showed an age-dependent increase in PDIA3 levels in the amygdala, entorhinal cortex, and ventral hippocampus. A significant reduction of PDIA3 was observed in 3×Tg-AD mice already at 6 months of age, as compared to age-matched Non-Tg mice. A comparative immunohistochemistry analysis performed on 3×Tg-AD mice at 6 (mild AD-like pathology) and 18 (severe AD-like pathology) months of age showed a direct correlation between the cellular level of Aβ and PDIA3 proteins in all the brain regions analysed, even if with different magnitudes. Additionally, an immunohistochemistry analysis showed the presence of PDIA3 in all post-mitotic neurons and astrocytes. Overall, altered PDIA3 levels appear to be age- and/or pathology-dependent, corroborating the ER chaperone's involvement in AD pathology, and supporting the PDIA3 protein as a potential novel therapeutic target for the treatment of AD.

Analgesic effects and metabolome analyses of laser- and electro-acupuncture combined therapies in paclitaxel-induced neuropathic pain model

Introduction

Allodynia, which can be induced by paclitaxel administration, is the presence of pain as a result of a stimulus that does not usually provoke pain. Many studies have investigated the analgesic efficacy of acupuncture, including laser acupuncture (LA) and electroacupuncture (EA). Although pain-related diseases are relatively common, few studies have analyzed the analgesic effects and mechanisms of LA combined with EA. The purpose of this study was to investigate the therapeutic effect and mechanism of manual acupuncture (MA), EA, LA, and combined therapy (LA + EA) in a paclitaxel-induced allodynia rat model.

Methods

A total of 56 rats were classified into eight groups: a normal (Nor, n = 7), a control (Con, n = 7), an MA (n = 7), an EA (n = 7), a 650-nm LA (650LA, n = 7), an 830-nm LA (830LA, n = 7), a 650-nm LA combined with EA (650LA + EA, n = 7), and an 830-nm LA combined with EA group (830LA + EA, n = 7). Allodynia was induced by intraperitoneal injection of 2 mg/kg of paclitaxel every other day for a total of four times except the Nor group. Acupuncture treatments were conducted at the points of Jungwan (CV12) and Joksamni (ST36) once every other day for 6 min, for a total of nine times. Withdrawal response reaction times and force intensity of the foot were measured before the start of the experiment, after the 4th paclitaxel administration (day 8), and after the 9th and last treatment (day 15). On the 16th day, mRNA and protein expression in the spinal nerves was assessed, and a metabolome analysis of the animals' feces was performed.

Results and discussion

Our analyses show that 650LA + EA treatment resulted in an upregulation of protein expression related to pain relief and nerve regeneration, whereas 830LA + EA treatment led to significant changes in metabolomes. This study demonstrates that a combination treatment of EA and LA can suppress allodynia and promote upregulation of protein expression related to nerve regeneration and is effective in changing the intestinal microbiome. Further large-scale research is required to assess the exact mechanism underlying the therapeutic effect of this combination treatment in pain-related diseases.

Elevation of miR-146a Inhibits BTG2/BAX Expression to Ameliorate Postoperative Cognitive Dysfunction Following Probiotics (VSL#3) Treatment

It has been reported that the gut microbiome modulates postoperative cognitive dysfunction (POCD), and that administration of probiotics (VSL#3) may effectively relieve POCD. In this study, we aimed to identify the underlying mechanism of VSL#3 in POCD. A mouse model of POCD was constructed in adult male C57BL/6 mice, which were then treated with VSL#3. VSL#3 exerted a protective role against POCD and resultant neuronal apoptosis. The expression of miR-146a was found to be downregulated in hippocampal tissues of POCD mice, while VSL#3 could restore its expression. Loss- and gain-function approaches were conducted to determine the roles of microRNA (miR)-146a, B-cell translocation gene 2 (BTG2), and Bcl-2-associated X protein (Bax) in post-operative effects on cognitive function and neuronal apoptosis. The levels of reactive oxygen species (ROS), malondialdehyde (MDA), and superoxide dismutase (SOD) were measured to determine oxidative stress in brain tissue. The dual-luciferase reporter gene assay identified that miR-146a could target BTG2 and negatively regulate its expression. BTG2 knockdown suppressed neuronal apoptosis and contributed to shortened time of latency, prolonged time of mice spent in the target quadrant, and reduced oxidative stress through downregulating Bax expression. Finally, VSL#3 treatment upregulated the expression of miR-146a to block BTG2/Bax axis and consequently inhibited neuronal apoptosis and reduced oxidative stress in POCD mice. Taken together, the study suggested that miR-146a-mediated suppression of BTG2/Bax contributed to the protective role of probiotics treatment against POCD.

Immunostaining for NeuN Does Not Show all Mature and Healthy Neurons in the Human and Pig Brain: Focus on the Hippocampus

Neuronal nuclei (NeuN) is a neuron-specific nuclear protein, reported to be stably expressed in most postmitotic neurons of the vertebrate nervous system. Reduced staining has been interpreted by some to indicate loss of cell viability in human studies, while others suggest this may be because of changes in the antigenicity of the target epitope. Preliminary studies in our laboratory found low immunostaining for the NeuN antibody on formalin fixed and paraffin embedded (FFPE) human brain tissue. We report on the techniques and results used to enhance the staining for NeuN in that tissue. In parallel, we stained NeuN in piglet brain tissue, sourced from an experimental model where methodological parameters, including those for tissue fixation and storage, were tightly controlled. In human FFPE brain tissue, we were unable to enhance NeuN immunostaining to a degree sufficient for cell counting. In contrast, we found consistently high levels of staining in the piglet brain tissue. We conclude that processes used for fixation and storage of human FFPE brain tissue are responsible for the reduced staining. These results emphasize that a cautionary approach should be taken when interpreting NeuN staining outcomes in human FFPE brain tissue.

Central nervous system-targeted adeno-associated virus gene therapy in methylmalonic acidemia

Methylmalonic acidemia (MMA) is a severe metabolic disorder most commonly caused by a mutation in the methylmalonyl-CoA mutase (MMUT) gene. Patients with MMA experience multisystemic disease manifestations and remain at risk for neurological disease progression, even after liver transplantation. Therefore, delivery of MMUT to the central nervous system (CNS) may provide patients with neuroprotection and, perhaps, therapeutic benefits. To specifically target the brain, we developed a neurotropic PHP.eB vector that used a CaMKII neuro-specific promoter to restrict the expression of the MMUT transgene in the neuraxis and delivered the adeno-associated virus (AAV) to mice with MMA. The PHP.eB vector transduced cells in multiple brain regions, including the striatum, and enabled high levels of expression of MMUT in the basal ganglia. Following the CNS-specific correction of MMUT expression, disease-related metabolites methylmalonic acid and 2-methylcitrate were significantly (p < 0.02) decreased in serum of treated MMA mice. Our results show that targeting MMUT expression to the CNS using a neurotropic capsid can decrease the circulating metabolite load in MMA and further highlight the benefit of extrahepatic correction for disorders of organic acid metabolism.

Induction of mesenchymal stem cell‑like transformation in rat primary glial cells using hypoxia, mild hypothermia and growth factors

The transformation of rat primary glial cells into mesenchymal stem cells (MSCs) is intriguing as more seed cells can be harvested. The present study aimed to evaluate the effects of growth factors, hypoxia and mild hypothermia on the transformation of primary glial cells into MSCs. Rat primary glial cells were induced to differentiate by treatment with hypoxia, mild hypothermia and basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF). Immunohistochemistry and western blotting were then used to determine the expression levels of glial fibrillary acidic protein (GFAP), nestin, musashi-1, neuron specific enolase (NSE) and neuronal nuclei (NeuN), in each treatment group. bFGF and EGF increased the proportion of CD44⁺ and CD105⁺ cells, while anaerobic mild hypothermia increased the proportion of CD90⁺ cells. The combination of bFGF and EGF, and anaerobic mild hypothermia increased the proportion of CD29⁺ cells and significantly decreased the proportions of GFAP⁺ cells and NSE⁺ cells. Treatment of primary glial cells with bFGF and EGF increased the expression levels of nestin, Musashi-1, NSE and NeuN. Anaerobic mild hypothermia increased the expression levels of Musashi-1 and decreased the expression levels of NSE and NeuN in glial cells. The results of the present study demonstrated that bFGF, EGF and anaerobic mild hypothermia treatments may promote the transformation of glial cells into MSC-like cells, and that the combination of these two treatments may have the optimal effect.

Naringenin Prevents Propofol Induced Neurodegeneration in Neonatal Mice Brain and Long-Term Neurocognitive Impacts on Adults

Background

Natural products have shown neuroprotective effects in neurodegenerative conditions. Naringenin is a natural flavonoid with various pharmacological activities especially antioxidant, anti-inflammatory and neuroprotective properties. We investigated the effects of naringenin on anesthetic propofol-induced impacts on neonatal mouse brain development and consequent long-term neurocognitive impacts during adulthood.

Materials and Methods

Female C57Bl/6 and male CD-1 mice and postnatal day 7 (P7) pups were exposed to propofol (2.5 mg/kg) and propofol with naringenin (50 mg/kg). Mice pups were allowed to grow until week 10 (adulthood), and memory and learning were assessed.

Results

Propofol caused neurodegeneration by inducing apoptosis in the neonatal mouse brains while naringenin administration prevented neuronal cell loss by preventing neuronal apoptosis in neonatal mouse brains. Propofol caused degenerative alterations in metabolic factors pH, PO₂, glucose and lactate, which were subsequently restored by naringenin treatment. Propofol-exposed mice, when developed into adults, showed long-term neuronal deficits, impaired neurocognitive functions, and memory and learning restrictions.

Conclusion

Administration of naringenin to propofol-exposed mice resulted in significant neuroprotective effects by restoring long-term neurocognitive functions. The molecular mechanism behind the effects of naringenin was mediated by suppressing apoptosis and preventing cellular inflammation. These findings suggest that propofol administration requires careful consideration and that naringenin may prevent neurodegeneration and neurocognitive functions.

The Role of Maternal Smoking in Sudden Fetal and Infant Death Pathogenesis

Maternal smoking is a risk factor for both sudden infant death syndrome (SIDS) and sudden intrauterine unexplained death syndrome (SIUDS). Both SIDS and SIUDS are more frequently observed in infants of smoking mothers. The global prevalence of smoking during pregnancy is 1.7% and up to 8.1% of women in Europe smoke during pregnancy and worldwide 250 million women smoke during pregnancy. Infants born to mothers who smoke have an abnormal response to hypoxia and hypercarbia and they also have reduced arousal responses. The harmful effects of tobacco smoke are mainly mediated by release of carbon monoxide and nicotine. Nicotine can enter the fetal circulation and affect multiple developing organs including the lungs, adrenal glands and the brain. Abnormalities in brainstem nuclei crucial to respiratory control, the cerebral cortex and the autonomic nervous system have been demonstrated. In addition, hypodevelopment of the intermediolateral nucleus in the spinal cord has been reported. It initiates episodic respiratory movements that facilitate lung development. Furthermore, abnormal maturation and transmitter levels in the carotid bodies have been described which would make infants more vulnerable to hypoxic challenges. Unfortunately, smoking cessation programs do not appear to have significantly reduced the number of pregnant women who smoke.

Molecular Basis of Sex Difference in Neuroprotection induced by Hypoxia Preconditioning in Zebrafish

Hypoxia, the major cause of ischemic injury, leads to debilitating disease in infants via birth asphyxia and cerebral palsy, whereas in adults via heart attack and stroke. A widespread, natural protective phenomenon termed 'hypoxic preconditioning' (PH) occurs when prior exposures to hypoxia eventually result in robust hypoxia resistance. Accordingly, we have developed and optimized a novel model of hypoxic preconditioning in adult zebrafish to mimic the tolerance of mini stroke(s) in human, which appears to protect against the severe damage inflicted by a major stroke event. Here, we observed a remarkable difference in the progression pattern of neuroprotection between preconditioning hypoxia followed by acute hypoxia (PH) group, and acute hypoxia (AH) only group, with noticeable sex difference when compared with normoxia behaviour upon recovery. Since gender difference has been reported in stroke risk factors and disease history, it was pertinent to investigate whether any such sex difference also exists in PH's protective mechanism against acute ischemic stroke. In order to elucidate the neural molecular mechanisms behind sex difference in neuroprotection induced by PH, a high throughput proteomics approach utilizing iTRAQ was performed, followed by protein enrichment analysis using ingenuity pathway analysis (IPA) tool. Out of thousands of significantly altered proteins in zebrafish brain, the ones having critical role either in neuroglial proliferation/differentiation or neurotrophic functions were validated by analyzing their expression levels in preconditioned (PH), acute hypoxia (AH), and normoxia groups. The data indicate that female zebrafish brains are more protected against the severity of AH when exposed to the hypoxic preconditioning. The study also sheds light on the involvement of many signalling pathways underlying sex difference in preconditioning-induced neuroprotective mechanism, which can be further validated for the therapeutic approach.

Silver nanoparticles induce size-dependent and particle-specific neurotoxicity to primary cultures of rat cerebral cortical neurons

Silver nanoparticles (AgNPs) are widely applied in many fields because of their excellent antibacterial activities. Toxicological studies have showed that AgNPs can cross the blood-brain barrier and exhibit high retention in the brain. Therefore, the potential neurotoxicity of AgNPs is raising serious concerns. This study investigated the neurotoxicological effects of AgNPs with two different sizes (20 nm and 70 nm, AgNPs-20 and AgNPs-70) using primary cultures of rat cerebral cortical neurons in mature and developing stages. The contribution of silver ion release was investigated by testing the effects of ionic silver in parallel. The results showed that both AgNPs-20 and AgNPs-70 significantly decreased neuronal cell viability, and AgNPs-20 had stronger toxicity compared with AgNPs-70. AgNP applications caused the granulated skeleton structure of the mature neurons with some broken synapses after a 24-h exposure, and inhibited neuronal growth during a 7-day exposure. Intracellular silver accumulation at non-cytotoxic exposure levels inhibited dopamine efflux, which was particle-specific and free of released silver ions. The findings herein can aid in guiding the proper applications of AgNPs in different areas, especially in medical use.

Sudden intrauterine unexplained death: time to adopt uniform postmortem investigative guidelines?

Background

Worldwide approximately 2.6 million are stillborn, mostly occurring in developing countries. In the great part these deaths are inexplicable. The evenness and standardisation of the diagnostic criteria are prerequisites to understand their pathogenesis. The core goal of this article is to propose new evidence based investigative post-mortem guidelines that should be adopted in all the Institutions especially when a fetal death, after a routine autopsy procedure, is diagnosed as “unexplained”. The proposed protocol is mainly focused on the anatomopathological examination of the autonomic nervous system and in particular of the brainstem where the main centers that control vital functions are located.

Methods

Updated investigative guidelines for the examination of unexplained stillbirths, prevalently focused on the histological examination of the brainstem, where the main centers that are involved in monitoring the vital functions are located, are here presented. A section of this protocol concerns the Immunohistochemical evaluation of specific functional markers such as the neuronal nuclear antigen, nicotinic acetylcholine receptors, serotonin, orexin, apoptosis and gliosis. The important role of risk factors, having regard in particular to maternal smoking and air pollution is also contemplated in these guidelines.

Results

Specific morphological and/or functional alterations of vital brainstem structures have been found with high incidence in over 100 cases of unexplained fetal death sent to the “Lino Rossi Research Center” of the Milan University according to the Italian law. These alterations were rarely detected in a group of control cases.

Conclusions

We hope this protocol can be adopted in all the Institutions notably for the examination of unexplained fetal deaths, in order to make uniform investigations. This will lead to identify a plausible explanation of the pathogenetic mechanism behind the unexplained fetal deaths and to design preventive strategies to decrease the incidence of these very distressing events for both parents and clinicians.

Trial registration

not applicable for this study.

Does the Apparent Diffusion Coefficient Value Predict Permanent Cerebral Ischemia/Reperfusion Injury in Rats?

RATIONALE AND OBJECTIVES

Variation in tissue damage after cerebral ischemia/reperfusion (I/R) can cause uncertainty in stroke-related studies, which can be reduced if the damage can be predicted early after ischemia by measuring the apparent diffusion coefficient (ADC). We investigated whether ADC measurement in the acute phase can predict permanent cerebral I/R injury.

MATERIALS AND METHODS

The middle cerebral artery occlusion model was established using the intraluminal suture method to induce 60 minutes of ischemia followed by reperfusion in rats. T2-weighted images and diffusion-weighted images were obtained at 30 minutes and 24 hours after ischemia. Neuronal cell survival was assessed by neuronal nuclei (NeuN) immunofluorescence staining. The correlation between relative ADC (rADC) values at 30 minutes and I/R injury at 24 hours after ischemia was analyzed. Magnetic resonance imaging results were confirmed by histologic analysis.

RESULTS

The correlation between rADC values at 30 minutes and 24 hours was strong in the ischemic core and peri-infarct region but moderate in the anterior choroidal and hypothalamic region. Histologic analysis revealed that the correlation between rADC values at 30 minutes and the number of NeuN-positive cells at 24 hours was strong in the ischemic core and peri-infarct region but moderate in the anterior choroidal and hypothalamic region. Furthermore, there was a strong positive correlation between the sum of rADC values of three regions at 30 minutes and the infarct volume at 24 hours.

CONCLUSION

ADC measurement in the acute phase can predict permanent cerebral I/R injury and provide important information for the evaluation of ischemic stroke.

Neuronal Membrane Disruption Occurs Late Following Diffuse Brain Trauma in Rats and Involves a Subpopulation of NeuN Negative Cortical Neurons

The repercussions of traumatic brain injury (TBI) endure years following the initial insult and involve chronic impairments/disabilities. Studies indicate that these morbidities stem from diffuse pathologies, however, knowledge regarding TBI-mediated diffuse pathologies, and in particular, diffuse neuronal membrane disruption, is limited. Membrane disruption has been shown to occur acutely following injury, primarily within neurons, however, the progression of TBI-induced membrane disruption remains undefined. Therefore, the current study investigated this pathology over a longer temporal profile from 6 h to 4 w following diffuse TBI induced using the central fluid percussion injury (CFPI) model in rats. To visualize membrane disruption, animals received an intracerebroventricular infusion of tagged cell-impermeable dextran 2 h prior to experimental endpoints at 6 h, 1 d, 3 d, 1 w, 2 w, or 4 w post-CFPI. The percentage of total neurons demonstrating dextran uptake, indicative of membrane disruption, was quantified within the lateral neocortex layers V and VI from 6 h to 4 w post-injury. We found that membrane disruption displayed a biphasic pattern, where nearly half of the neurons were membrane disrupted sub-acutely, from 6 h to 3 d post-TBI. At 1 w the membrane disrupted population was dramatically reduced to levels indistinguishable from sham controls. However, by 2 and 4 w following CFPI, approximately half of the neurons analyzed displayed membrane disruption. Moreover, our data revealed that a subset of these late membrane disrupted neurons were NeuN negative (NeuN-). Correlative western blot analyses, however, revealed no difference in NeuN protein expression in the lateral neocortex at any time following injury. Furthermore, the NeuN- membrane disrupted neurons did not co-label with traditional markers of astrocytes, microglia, oligodendrocytes, or NG2 cells. Immunohistochemistry against NeuN, paired with a hematoxylin and eosin counter-stain, was performed to quantify the possibility of overall NeuN+ neuronal loss following CFPI. A NeuN- population was observed consistently in both sham and injured animals regardless of time post-injury. These data suggest that there is a consistent subpopulation of NeuN- neurons within the lateral neocortex regardless of injury and that these NeuN- neurons are potentially more vulnerable to late membrane disruption. Better understanding of membrane disruption could provide insight into the mechanisms of diffuse pathology and lead to the discovery of novel treatments for TBI.

Low-dose Dexamethasone Increases Autophagy in Cerebral Cortical Neurons of Juvenile Rats with Sepsis Associated Encephalopathy

Studies have shown that a certain dose of dexamethasone can improve the survival rate of patients with sepsis, and in sepsis associated encephalopathy (SAE), autophagy plays a regulatory role in brain function. Here, we proved for the first time that small-dose dexamethasone (SdDex) can regulate the autophagy of cerebral cortex neurons in SAE rats and plays a protective role. Cortical neurons were cultured in vitro in a septic microenvironment and a sepsis rat model was established. The small-dose dexamethasone (SdDex) or high-dose dexamethasone (HdDex) was used to intervene in neurons or SAE rats. Through fluorescence microscopy and western blot analysis, the expressions of microtubule-associated protein 1 light chain 3 (LC3), p62/sequestosome1 (p62/SQSTM1), mammalian target of rapamycin (mTOR) signaling pathway related proteins, and apoptosis-related proteins were detected. Theresultsshowthat compared with those in SAE rats, the cortical pathological changes in SAE rats treated with SdDex were improved, and damaged substances were encapsulated and degraded by autophagosomes in neurons. Additionally, similar to neurons in vitro, cortical autophagy was further activated and the mTOR signaling pathway was inhibited. After HdDex treatment, the mTOR signaling pathway in cortex is inhibited, but further activation of autophagy is not obvious, the cortical pathological changes were further worsened and the ultrastructure of neurons was disturbed. Furthermore, the HdDex group exhibited the most obvious apoptosis. SdDex can regulate autophagy of cortical neurons by inhibiting the mTOR signaling pathway and plays a protective role. Brain damage induced by HdDex may be related to the activation of apoptosis.

Bexarotene therapy ameliorates behavioral deficits and induces functional and molecular changes in very-old Triple Transgenic Mice model of Alzheimer´s disease

Introduction

Bexarotene, a retinoid X receptor agonist, improves cognition in murine models of Alzheimer’s disease (AD). This study evaluated the effects of bexarotene on pathological and electrophysiological changes in very old triple transgenic AD mice (3xTg-AD mice).

Methods

24-month-old 3xTg-AD mice were treated with bexarotene (100 mg/kg/day for 30 days). The Morris water maze was used to evaluate spatial memory; immunofluorescence and confocal microscopy were used to evaluate pathological changes; and in vivo electrophysiological recordings were used to evaluate basal transmission and plasticity in the commissural CA3-CA1 pathway.

Results

In addition to cognitive improvement, bexarotene-treated 3xTg-AD mice were found to have 1) reductions of astrogliosis and reactive microglia both in cortex and hippocampus; 2) increased ApoE expression restricted to CA1; 3) increased number of cells co-labeled with ApoE and NeuN; 4) recovery of NeuN expression, suggesting neuronal protection; and, 5) recovery of basal synaptic transmission and synaptic plasticity.

Discussion

These results indicate that bexarotene-induced improvement in cognition is due to multiple changes that contribute to recovery of synaptic plasticity.

Therapeutic effect of transplantation of human bone marrow‑derived mesenchymal stem cells on neuron regeneration in a rat model of middle cerebral artery occlusion

Human bone marrow-derived mesenchymal stromal cells (hBMSCs) have been revealed to be beneficial for the regeneration of tissues and cells in several diseases. The present study aimed to elucidate the mechanisms underlying the effect of hBMSC transplantation on neuron regeneration in a rat model of middle cerebral artery occlusion (MCAO). The hBMSCs were isolated, cultured and identified. A rat model of MCAO was induced via the modified Longa method. Neurological severity scores (NSS) were adopted for the evaluation of neuronal function in the model rats after cell transplantation. Next, the expression levels of nestin, β-III-tubulin (β-III-Tub), glial fibrillary acidic protein (GFAP), HNA and neuronal nuclear antigen (NeuN) were examined, as well as the positive expression rates of human neutrophil alloantigen (HNA), nestin, NeuN, β-III-Tub and GFAP. The NSS, as well as the mRNA and protein expression of nestin, decreased at the 1st, 2nd, 4 and 8th weeks, while the mRNA and protein expression of NeuN, β-III-Tub and GFAP increased with time. In addition, after treatment, the MCAO rats showed decreased NSS and mRNA and protein expression of nestin, but elevated mRNA and protein expression of NeuN, β-III-Tub and GFAP at the 2nd, 4 and 8th weeks, and decreased positive expression of HNA and nestin with enhanced expression of NeuN, β-III-Tub and GFAP. Therefore, the present findings demonstrated that hBMSC transplantation triggered the formation of nerve cells and enhanced neuronal function in a rat model of MCAO.

Secondary-Ion Mass Spectrometry Images Cardiolipins and Phosphatidylethanolamines at the Subcellular Level

Millions of diverse molecules constituting the lipidome act as important signals within cells. Of these, cardiolipin (CL) and phosphatidylethanolamine (PE) participate in apoptosis and ferroptosis, respectively. Their subcellular distribution is largely unknown. Imaging mass spectrometry is capable of deciphering the spatial distribution of multiple lipids at subcellular levels. Here we report the development of a unique 70 keV gas-cluster ion beam that consists of (CO₂ )_n ⁺ (n>10 000) projectiles. Coupled with direct current beam buncher-time-of-flight secondary-ion mass spectrometry, it is optimized for sensitivity towards high-mass species (up to m/z 3000) at high spatial resolution (1 μm). In combination with immunohistochemistry, phospholipids, including PE and CL, have been assessed in subcellular compartments of mouse hippocampal neuronal cells and rat brain tissue.

Metal chaperones: a novel therapeutic strategy for brain injury?

OBJECTIVE

This study sought to assess the potential efficacy of a novel class of metal chaperone on the outcomes in an animal model of a controlled cortical impact. This work was predicated on previous observations that this class of compound has exhibited neuroprotective potential in other models of aging and neurodegeneration.

RESEARCH DESIGN

The study employed a controlled cortical impact traumatic brain injury in three month old mice with subsequent behavioral and cellular assessments to determine therapeutic efficacy.

METHODS

Cognitive (Y-maze) and motor assessments (Rotarod and Open Field) were employed to determine behavioral end points. Histological-based methods were utilized to assess neuronal integrity, astrocytosis, and lesion volume.

OUTCOMES

We demonstrate here that acute post-injury treatment with PBT2 (Prana Biotechnology) is sufficient to maintain neuronal integrity (evidenced by decreased lesion area and increased numbers of neurons; decreased astrocytosis was also present) and to normalize performance in cognitive testing (Y-maze). These effects occurred within days and were maintained for the entire duration of the study (26 days post-injury). These data support the further interrogation of the utility of metal chaperones for the treatment and/or prevention of the neuroanatomical, biochemical, and behavioral deficits that occur following brain injuries of different etiologies.

Contribution of Fibrinogen to Inflammation and Neuronal Density in Human Traumatic Brain Injury

Traumatic brain injury (TBI) is a leading cause of death and disability, particularly among the young. Despite this, no disease-specific treatments exist. Recently, blood-brain barrier disruption and parenchymal fibrinogen deposition have been reported in acute traumatic brain injury and in long-term survival; however, their contribution to the neuropathology of TBI remains unknown. The presence of fibrinogen-a well-documented activator of microglia/macrophages-may be associated with neuroinflammation, and neuronal/axonal injury. To test this hypothesis, cases of human TBI with survival times ranging from 12 h to 13 years (survival <2 months, n = 15; survival >1 year, n = 6) were compared with uninjured controls (n = 15). Tissue was selected from the frontal lobe, temporal lobe, corpus callosum, cingulate gyrus, and brainstem, and the extent of plasma protein (fibrinogen and immunoglobulin G [IgG]) deposition, microglial/macrophage activation (CD68 and ionized calcium-binding adapter molecule 1 [Iba-1] immunoreactivity), neuronal density, and axonal transport impairment (β-amyloid precursor protein [βAPP] immunoreactivity) were assessed. Quantitative analysis revealed a significant increase in parenchymal fibrinogen and IgG deposition following acute TBI compared with long-term survival and control. Fibrinogen, but not IgG, was associated with microglial/macrophage activation and a significant reduction in neuronal density. Perivascular fibrinogen deposition also was associated with microglial/macrophage clustering and accrual of βAPP in axonal spheroids, albeit rarely. These findings mandate the future exploration of causal relationships between fibrinogen deposition, microglia/macrophage activation, and potential neuronal loss in acute TBI.

Calcium: A novel and efficient inducer of differentiation of adipose-derived stem cells into neuron-like cells

This study comparatively investigated the effectiveness of calcium and other well-known inducers such as isobutylmethylxanthine (IBMX) and insulin in differentiating human adipose-derived stem cells (ADSCs) into neuronal-like cells. ADSCs were immunophenotyped and differentiated into neuron-like cells with different combinations of calcium, IBMX, and insulin. Calcium mobilization across the membrane was determined. Differentiated cells were characterized by cell cycle profiling, staining of Nissl bodies, detecting the gene expression level of markers such as neuronal nuclear antigen (NeuN), microtubule associated protein 2 (MAP2), neuron-specific enolase (NSE), doublecortin, synapsin I, glial fibrillary acidic protein (GFAP), and myelin basic protein (MBP) by quantitative real-time polymerase chain reaction (quantitative real-time polymerase chain reaction (qRT-PCR) and protein level by the immunofluorescence technique. Treatment with Ca + IBMX + Ins induced neuronal appearance and projection of neurite-like processes in the cells, accompanied with inhibition of proliferation and halt in the cell cycle. A significantly higher expression of MBP, GFAP, NeuN, NSE, synapsin 1, doublecortin, and MAP2 was detected in differentiated cells, confirming the advantages of Ca + IBMX + Ins to the other combinations of inducers. Here, we showed an efficient protocol for neuronal differentiation of ADSCs, and calcium fostered differentiation by augmenting the number of neuron-like cells and instantaneous increase in the expression of neuronal markers.

Plasmonic nanoparticle-based expansion microscopy with surface-enhanced Raman and dark-field spectroscopic imaging

Fluorescence-based expansion microscopy (ExM) is a new technique which can yield nanoscale resolution of biological specimen on a conventional fluorescence microscope through physical sample expansion up to 20 times its original dimensions while preserving structural information. It however inherits known issues of fluorescence microscopy such as photostability and multiplexing capabilities, as well as an ExM-specific issue in signal intensity reduction due to a dilution effect after expansion. To address these issues, we propose using antigen-targeting plasmonic nanoparticle labels which can be imaged using surface-enhanced Raman scattering spectroscopy (SERS) and dark-field spectroscopy. We demonstrate that the nanoparticles enable multimodal imaging: bright-field, dark-field and SERS, with excellent photostability, contrast enhancement and brightness.

Spread of aggregates after olfactory bulb injection of α-synuclein fibrils is associated with early neuronal loss and is reduced long term

Parkinson’s disease is characterized by degeneration of substantia nigra dopamine neurons and by intraneuronal aggregates, primarily composed of misfolded α-synuclein. The α-synuclein aggregates in Parkinson’s patients are suggested to first appear in the olfactory bulb and enteric nerves and then propagate, following a stereotypic pattern, via neural pathways to numerous regions across the brain. We recently demonstrated that after injection of either mouse or human α-synuclein fibrils into the olfactory bulb of wild-type mice, α-synuclein fibrils recruited endogenous α-synuclein into pathological aggregates that spread transneuronally to over 40 other brain regions and subregions, over 12 months. We previously reported the progressive spreading of α-synuclein aggregates, between 1 and 12 months following α-synuclein fibril injections, and now report how far the pathology has spread 18- and 23-month post-injection in this model. Our data show that between 12 and 18 months, there is a further increase in the number of brain regions exhibiting pathology after human, and to a lesser extent mouse, α-synuclein fibril injections. At both 18 and 23 months after injection of mouse and human α-synuclein fibrils, we observed a reduction in the density of α-synuclein aggregates in some brain regions compared to others at 12 months. At 23 months, no additional brain regions exhibited α-synuclein aggregates compared to earlier time points. In addition, we also demonstrate that the induced α-synucleinopathy triggered a significant early neuron loss in the anterior olfactory nucleus. By contrast, there was no loss of mitral neurons in the olfactory bulb, even at 18 month post-injection. We speculate that the lack of continued progression of α-synuclein pathology is due to compromise of the neural circuitry, consequential to neuron loss and possibly to the activation of proteolytic mechanisms in resilient neurons of wild-type mice that counterbalances the spread and seeding by degrading pathogenic α-synuclein.

Neuron loss and degeneration in the progression of TDP-43 in frontotemporal lobar degeneration

Frontotemporal lobar degeneration with TDP-43 inclusions (FTLD-TDP) is associated with the accumulation of pathological neuronal and glial intracytoplasmic inclusions as well as accompanying neuron loss. We explored if cortical neurons detected by NeuN decreased with increasing TDP-43 inclusion pathology in the postmortem brains of 63 patients with sporadic and familial FTLD-TDP. Semi-automated quantitative algorithms to quantify histology in tissue sections stained with antibodies specific for pathological or phosphorylated TDP-43 (pTDP-43) and NeuN were developed and validated in affected (cerebral cortex) and minimally affected (cerebellar cortex) brain regions of FTLD-TDP cases. Immunohistochemistry (IHC) for NeuN and other neuronal markers found numerous neurons lacking reactivity, suggesting NeuN may reflect neuron health rather than neuron loss in FTLD. We found three patterns of NeuN and pTDP-43 reactivity in our sample of cortical tissue representing three intracortical region-specific stages of FTLD-TDP progression: Group 1 showed low levels of pathological pTDP-43 and high levels NeuN, while Group 2 showed increased levels of pTDP-43, and Group 3 tissues were characterized by reduced staining for both pTDP-43 and NeuN. Comparison of non-C9orf72/GRN FTLD-TDP with cases linked to both GRN mutations and C9orf72 expansions showed a significantly increased frequency of Group 3 histopathology in the latter cases, suggesting more advanced cortical disease. Hence, we propose that IHC profiles of pTDP-43 and NeuN reflect the burden of pTDP-43 and its deleterious effects on neuron health.

Towards Better Understanding of the Pathogenesis of Neuronal Respiratory Network in Sudden Perinatal Death

Sudden perinatal death that includes the victims of sudden infant death syndrome, sudden intrauterine death syndrome, and stillbirth are heartbreaking events in the life of parents. Most of the studies about sudden perinatal death were reported from Italy, highlighting two main etiological factors: prone sleeping position and smoking. Other probable contributory factors are prematurity, male gender, lack of breastfeeding, respiratory tract infections, use of pacifiers, infant botulism, extensive use of pesticides and insecticides, etc. However, extensive studies across the world are required to establish the role of these factors in a different subset of populations. Previous studies confirmed the widely accepted hypothesis that neuropathology of the brainstem is one of the main cause of sudden perinatal death. This study is an effort to summarize the neuropathological evaluation of the brainstems and their association to sudden perinatal death. Brainstem nuclei in vulnerable infants undergo certain changes that may alter the sleep arousal cycle, cardiorespiratory control, and ultimately culminate in death. This review focuses on the roles of different brainstem nuclei, their pathologies, and the established facts in this regard in terms of it's link to such deaths. This study will also help to understand the role of brainstem nuclei in controlling the cardiorespiratory cycles in sudden perinatal death and may provide a better understanding to resolve the mystery of these deaths in future. It is also found that a global initiative to deal with perinatal death is required to facilitate the diagnosis and prevention in developed and as well as developing countries.

Effects of SDF-1/CXCR4 on the Repair of Traumatic Brain Injury in Rats by Mediating Bone Marrow Derived Mesenchymal Stem Cells

Our study aims to investigate the effects of the SDF-1/CXCR4 axis on the repair of traumatic brain injury (TBI) in rats by mediating bone marrow derived from mesenchymal stem cells (BMSCs). Healthy male SD rats were collected, their tibiofibulars were removed, cultured, and BMSCs were collected. The expression of cell-surface molecular proteins was examined using flow cytometry. The mRNA and protein expression of CXCR4 in cells were tested using qRT-PCR and western blotting analysis. An electronic brain injury instrument was utilized to build TBI rat models and each rat was assigned into the experiment, positive control and control groups (10 rats in each group). The morris water maze was used to calculate the escape latency and number of times rats in each group crossed the platform. Neurological severity scores (NSS) was calculated to evaluate the recovery of neurological functioning. The distribution of neuronal nuclear antigens was detected using double-labeling immunohistochemistry. The morphological changes in the hippocampal neuronal and the number of BrdU-positive cells were observed through Nissl's staining and high magnification. The mRNA and protein expressions of CXCR4 were gradually increased as SDF-1 concentration increased. NGF and BDNF positive cells were expressed in each group. The distribution of neuronal nuclear antigens in the experiment group was elevated compared to the control and positive control groups. Among the three groups, the experimental group had the shortest escape latency and the highest number platform crossings. The difference in NSS among the three groups was significant. The experimental group had better cell morphology and a higher number of BrdU-positive cells than the other groups. The present study demonstrates that transplanting BMSCs with SDF-1-induced CXCR4 expression can promote the repair of TBI. This is expected to become a new treatment regimen for TBI.

Metabolomics and neuroanatomical evaluation of post-mortem changes in the hippocampus

Understanding the human brain is the ultimate goal in neuroscience, but this is extremely challenging in part due to the fact that brain tissue obtained from autopsy is practically the only source of normal brain tissue and also since changes at different levels of biological organization (genetic, molecular, biochemical, anatomical) occur after death due to multiple mechanisms. Here we used metabolomic and anatomical techniques to study the possible relationship between post-mortem time (PT)-induced changes that may occur at both the metabolomics and anatomical levels in the same brains. Our experiments have mainly focused on the hippocampus of the mouse. We found significant metabolomic changes at 2 h PT, whereas the integrity of neurons and glia, at the anatomical/ neurochemical level, was not significantly altered during the first 5 h PT for the majority of histological markers.

Updates on the Methodological Approaches for Carrying Out an In-Depth Study of the Cardiac Conduction System and the Autonomic Nervous System of Victims of Sudden Unexplained Fetal and Infant Death

This article contains a set of protocols for histopathological techniques that can be used for carrying out in-depth studies of cases of sudden infant death syndrome and sudden intrauterine unexplained fetal death syndrome. In order to enable researchers to advance hypotheses regarding the causes of the unexpected death of infants and fetuses, the authors propose three innovative and accurate methodologies for studying the cardiac conduction system, the peripheral cardiac nervous system, and the central autonomic nervous system. Over the years, these protocols have been developed, modified, and improved on a vast number of cases which has enabled pathologists to carry out the microscopic analyses of the structures which regulate life, in order to highlight all the possible morphological substrates of pathophysiological mechanisms that may underlie these syndromes.

In memory of our research professor Lino Rossi (1923–2004).

Study of the chlorpyrifos neurotoxicity using neural differentiation of adipose tissue-derived stem cells

Chlorpyrifos (CPF) is the most commonly used organophosphorus insecticide which causes neurodevelopmental toxicity. So far, animals have been used as ideal models for neurotoxicity studies, but working with animals is very expensive, laborious, and ethically challenging. This has encouraged researchers to seek alternatives. During recent years, several studies have reported successful differentiation of embryonic and adult stem cells to neurons. This has provided an excellent model for neurotoxicologic studies. In this study, neural differentiation of mouse adipose tissue-derived stem cells (ADSCs) was used as an in vitro model for investigation of CPF neurotoxicity. For this purpose, mouse ADSCs were cultured in a medium containing knockout serum replacement and were treated with different concentrations of CPF at several stages of differentiation. Cytotoxic effect of CPF and the expression of neuron-specific genes and proteins were studied in the differentiating ADSCs. Furthermore, the activity of acetylcholinesterase was assessed by Ellman assay at different stages of differentiation. This study showed that up to 500 μM CPF did not alter viability of the undifferentiated ADSCs, whereas viability of the differentiating cells decreased with 500 μM CPF. CPF upregulated the expression of some neuron-specific genes and seemed to decrease the number of β-tubulin III and MAP2 proteins-expressing cells. There was no detectable acetylcholine esterase activity in differentiated ADSCs. In summary, it was shown that CPF treatment can decrease the viability of ADSC-derived neurons and dysregulate the expression of some neuronal markers through acetylcholinesterase-independent mechanisms. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1510-1519, 2016.

Neuronal Injury, Gliosis, and Glial Proliferation in Two Models of Temporal Lobe Epilepsy

It is estimated that 30%-40% of epilepsy patients are refractory to therapy and animal models are useful for the identification of more efficacious therapeutic agents. Various well-characterized syndrome-specific models are needed to assess their relevance to human seizure disorders and their validity for testing potential therapies. The corneal kindled mouse model of temporal lobe epilepsy (TLE) allows for the rapid screening of investigational compounds, but there is a lack of information as to the specific inflammatory pathology in this model. Similarly, the Theiler murine encephalomyelitis virus (TMEV) model of TLE may prove to be useful for screening, but quantitative assessment of hippocampal pathology is also lacking. We used immunohistochemistry to characterize and quantitate acute neuronal injury and inflammatory features in dorsal CA1 and dentate gyrus regions and in the directly overlying posterior parietal cortex at 2 time points in each of these TLE models. Corneal kindled mice were observed to have astrogliosis, but not microgliosis or neuron cell death. In contrast, TMEV-injected mice had astrogliosis, microgliosis, neuron death, and astrocyte and microglial proliferation. Our results suggest that these 2 animal models might be appropriate for evaluation of distinct therapies for TLE.

Pituitary adenoma-neuronal choristoma is a pituitary adenoma with ganglionic differentiation

The presence of ganglion cells within an endocrine pituitary tumor has been named hamartoma, choristoma, gangliocytoma, or most recently pituitary adenoma-neuronal choristoma (PANCH). The presence of neuronal differentiation in regular pituitary adenomas has been previously suggested, however, its origin, the extent of its presence, and the relationship between the neuronal elements and the pituitary adenoma remain uncertain. Thus, to further explore the neuronal potential of pituitary tumors, we used immunohistochemistry on pituitary tumors of different grades, with a neuronal antigen protein (NeuN) antibody as a specific marker for mature neuronal differentiation. We found NeuN expression in 26.47% (9/34) cases of pituitary tumors without ganglionic differentiation (7 adenomas, 1 atypical adenoma and 1 pituitary carcinoma), in addition to NeuN expression in pituitary adenomas with ganglionic cells (2/2). Thus, neuronal expression is an innate property of pituitary adenomas. We propose that the rare presence of ganglionic cells in pituitary adenomas is not the result of a separate lesion or "collision sellar tumors", as previously suggested, but a ganglionic neuronal differentiation in an endocrine neoplasm. The ganglionic cells may be arising from uncommitted stem/progenitor cells that contain both neuronal and endocrine properties. A label of "pituitary adenoma with ganglionic differentiation" would better reflect the dual differentiation in a neuroendocrine tumor than the current label "PANCH".

A New Theory to Explain the Underlying Pathogenetic Mechanism of Sudden Infant Death Syndrome

The author, on the basis of numerous studies on the neuropathology of SIDS, performed on a very wide set of cases, first highlights the neuronal centers of the human brainstem involved in breathing control in perinatal life, with the pontine Kölliker-Fuse nucleus (KFN) as main coordinator. What emerges from this analysis is that the prenatal respiratory movements differ from those post-natally in two respects: (1) they are episodic, only aimed at the lung development and (2) they are abolished by hypoxia, not being of vital importance in utero, mainly to limit the consumption of oxygen. Then, as this fetal inhibitory reflex represents an important defense expedient, the author proposes a new original interpretation of the pathogenetic mechanism leading to SIDS. Infants, in a critical moment of the autonomic control development, in hypoxic conditions could awaken the reflex left over from fetal life and arrest breathing, as he did in similar situations in prenatal life, rather than promote the hyperventilation usually occurring to restore the normal concentration of oxygen. This behaviour obviously leads to a fatal outcome. This hypothesis is supported by immunohistochemical results showing in high percentage of SIDS victims, and not in age-matched infant controls, neurochemical alterations of the Kölliker-Fuse neurons, potentially indicative of their inactivation. The new explanation of SIDS blames a sort of auto-inhibition of the KFN functionality, wrongly arisen with the same protective purpose to preserve the life in utero, as trigger of the sudden infant death.

CRF-amplified neuronal TLR4/MCP-1 signaling regulates alcohol self-administration

Alcohol dependence is a complex disorder that initiates with episodes of excessive alcohol drinking known as binge drinking. It has a 50-60% risk contribution from inherited susceptibility genes; however, their exact identity and function are still poorly understood. We report that alcohol-preferring P rats have innately elevated levels of Toll-like receptor 4 (TLR4) and monocyte chemotactic protein-1 (MCP-1) that colocalize in neurons from the central nucleus of the amygdala (CeA) and ventral tegmental area (VTA). To examine the potential role of a TLR4/MCP-1 signal, we used Herpes Simplex Virus (HSV) vectors (amplicons) that retain in vivo neurotropism. Infusion of amplicons for TLR4 or MCP-1 siRNA into the CeA or VTA from the P rats inhibited target gene expression and blunted binge drinking. A similarly delivered amplicon for scrambled siRNA did not inhibit TLR4 or MCP-1 expression nor reduce binge drinking, identifying a neuronal TLR4/MCP-1 signal that regulates the initiation of voluntary alcohol self-administration. The signal was sustained during alcohol drinking by increased expression of corticotropin-releasing factor and its feedback regulation of TLR4 expression, likely contributing to the transition to alcohol dependence.