Human endogenous retrovirus K contributes to a stem cell niche in glioblastoma.

Human endogenous retroviruses (HERVs) are ancestral viral relics that constitute nearly 8% of the human genome. Although normally silenced, the most recently integrated provirus HERV-K (HML-2) can be reactivated in certain cancers. Here, we report pathological expression of HML-2 in malignant gliomas in both cerebrospinal fluid and tumor tissue that was associated with a cancer stem cell phenotype and poor outcomes. Using single-cell RNA-Seq, we identified glioblastoma cellular populations with elevated HML-2 transcripts in neural progenitor-like cells (NPC-like) that drive cellular plasticity. Using CRISPR interference, we demonstrate that HML-2 critically maintained glioblastoma stemness and tumorigenesis in both glioblastoma neurospheres and intracranial orthotopic murine models. Additionally, we demonstrate that HML-2 critically regulated embryonic stem cell programs in NPC-derived astroglia and altered their 3D cellular morphology by activating the nuclear transcription factor OCT4, which binds to an HML-2-specific long-terminal repeat (LTR5Hs). Moreover, we discovered that some glioblastoma cells formed immature retroviral virions, and inhibiting HML-2 expression with antiretroviral drugs reduced reverse transcriptase activity in the extracellular compartment, tumor viability, and pluripotency. Our results suggest that HML-2 fundamentally contributes to the glioblastoma stem cell niche. Because persistence of glioblastoma stem cells is considered responsible for treatment resistance and recurrence, HML-2 may serve as a unique therapeutic target.

Detection of SARS-CoV-2 Nucleocapsid and Microvascular Disease in the Brain: A Case Report.

BACKGROUND AND OBJECTIVES: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can cause a wide range of neurologic complications; however, its neuropenetrance during the acute phase of the illness is unknown. METHODS: Extracellular vesicles were isolated from brain biopsy tissue from a patient undergoing epilepsy surgery using ultracentrifugation and analyzed by Western blot and qPCR for the presence of virus protein and RNA, respectively. Biopsy tissue was assessed by immunohistochemistry for the presence of microvascular damage and compared with 3 other non-COVID surgical epilepsy brain tissues. RESULTS: We demonstrate the presence of viral nucleocapsid protein in extracellular vesicles and microvascular disease in the brain of a patient undergoing epilepsy surgery shortly after SARS-CoV-2 infection. Endothelial cell activation was indicated by increased levels of platelet endothelial cell adhesion molecule-1 and was associated with fibrinogen leakage and immune cell infiltration in the biopsy tissue as compared with control non-COVID surgical epilepsy brain tissues. DISCUSSION: Despite the lack of evidence of viral replication within the brain, the presence of the nucleocapsid protein was associated with disease-specific endothelial cell activation, fibrinogen leakage, and immune cell infiltration.

Human Endogenous Retrovirus K Envelope in Spinal Fluid of Amyotrophic Lateral Sclerosis Is Toxic.

OBJECTIVE: Human endogenous retroviruses have been implicated in neurodegenerative diseases including amyotrophic lateral sclerosis (ALS). Expression of human endogenous retrovirus K (HERV-K) subtype HML-2 envelope (Env) in human neuronal cultures and in transgenic mice results in neurotoxicity and neurodegeneration, and mice expressing HML-2 Env display behavioral and neuromuscular characteristics resembling ALS. This study aims to characterize the neurotoxic properties of HML-2 Env. METHODS: Env neurotoxicity was detected in ALS cerebrospinal fluid and confirmed using recombinant Env protein in a cell-based assay and a mouse model. The mechanism of neurotoxicity was assessed with immunoprecipitation followed by mass spectrometry and Western blot, and by screening a panel of inhibitors. RESULTS: We observed that recombinant HML-2 Env protein caused neurotoxicity resulting in neuronal cell death, retraction of neurites, and decreased neuronal electrical activity. Injection of the Env protein into the brains of mice also resulted in neuronal cell death. HML-2 Env protein was also found in the cerebrospinal fluid of patients with sporadic ALS. The neurotoxic properties of the Env and the cerebrospinal fluid could be rescued with the anti-Env antibody. The Env was found to bind to CD98HC complexed to ß1 integrin on the neuronal cell surface. Using a panel of compounds to screen for their ability to block Env-induced neurotoxicity, we found that several compounds were protective and are linked to the ß1 integrin pathway. INTERPRETATION: HERV-K Env is released extracellularly in ALS and causes neurotoxicity via a novel mechanism. Present results pave the way for new treatment strategies in sporadic ALS. ANN NEUROL 2022;92:545-561.

Fluconazole Is Neuroprotective via Interactions with the IGF-1 Receptor.

There is a continuing unmet medical need to develop neuroprotective strategies to treat neurodegenerative disorders. To address this need, we screened over 2000 compounds for potential neuroprotective activity in a model of oxidative stress and found that numerous antifungal agents were neuroprotective. Of the identified compounds, fluconazole was further characterized. Fluconazole was able to prevent neurite retraction and cell death in in vitro and in vivo models of toxicity. Fluconazole protected neurons in a concentration-dependent manner and exhibited efficacy against several toxic agents, including 3-nitropropionic acid, N-methyl D-aspartate, 6-hydroxydopamine, and the HIV proteins Tat and gp120. In vivo studies indicated that systemically administered fluconazole was neuroprotective in animals treated with 3-nitropropionic acid and prevented gp120-mediated neuronal loss. In addition to neuroprotection, fluconazole also induced proliferation of neural progenitor cells in vitro and in vivo. Fluconazole mediates these effects through upregulation and signaling via the insulin growth factor-1 receptor which results in decreased cAMP production and increased phosphorylation of Akt. Blockade of the insulin growth factor-1 receptor signaling with the selective inhibitor AG1024 abrogated the effects of fluconazole. Our studies suggest that fluconazole may be an attractive candidate for treatment of neurodegenerative diseases due to its protective properties against several categories of neuronal insults and its ability to spur neural progenitor cell proliferation.

Mild respiratory COVID can cause multi-lineage neural cell and myelin dysregulation.

COVID survivors frequently experience lingering neurological symptoms that resemble cancer-therapy-related cognitive impairment, a syndrome for which white matter microglial reactivity and consequent neural dysregulation is central. Here, we explored the neurobiological effects of respiratory SARS-CoV-2 infection and found white-matter-selective microglial reactivity in mice and humans. Following mild respiratory COVID in mice, persistently impaired hippocampal neurogenesis, decreased oligodendrocytes, and myelin loss were evident together with elevated CSF cytokines/chemokines including CCL11. Systemic CCL11 administration specifically caused hippocampal microglial reactivity and impaired neurogenesis. Concordantly, humans with lasting cognitive symptoms post-COVID exhibit elevated CCL11 levels. Compared with SARS-CoV-2, mild respiratory influenza in mice caused similar patterns of white-matter-selective microglial reactivity, oligodendrocyte loss, impaired neurogenesis, and elevated CCL11 at early time points, but after influenza, only elevated CCL11 and hippocampal pathology persisted. These findings illustrate similar neuropathophysiology after cancer therapy and respiratory SARS-CoV-2 infection which may contribute to cognitive impairment following even mild COVID.

Mild respiratory SARS-CoV-2 infection can cause multi-lineage cellular dysregulation and myelin loss in the brain.

Survivors of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection frequently experience lingering neurological symptoms, including impairment in attention, concentration, speed of information processing and memory. This long-COVID cognitive syndrome shares many features with the syndrome of cancer therapy-related cognitive impairment (CRCI). Neuroinflammation, particularly microglial reactivity and consequent dysregulation of hippocampal neurogenesis and oligodendrocyte lineage cells, is central to CRCI. We hypothesized that similar cellular mechanisms may contribute to the persistent neurological symptoms associated with even mild SARS-CoV-2 respiratory infection. Here, we explored neuroinflammation caused by mild respiratory SARS-CoV-2 infection - without neuroinvasion - and effects on hippocampal neurogenesis and the oligodendroglial lineage. Using a mouse model of mild respiratory SARS-CoV-2 infection induced by intranasal SARS-CoV-2 delivery, we found white matter-selective microglial reactivity, a pattern observed in CRCI. Human brain tissue from 9 individuals with COVID-19 or SARS-CoV-2 infection exhibits the same pattern of prominent white matter-selective microglial reactivity. In mice, pro-inflammatory CSF cytokines/chemokines were elevated for at least 7-weeks post-infection; among the chemokines demonstrating persistent elevation is CCL11, which is associated with impairments in neurogenesis and cognitive function. Humans experiencing long-COVID with cognitive symptoms (48 subjects) similarly demonstrate elevated CCL11 levels compared to those with long-COVID who lack cognitive symptoms (15 subjects). Impaired hippocampal neurogenesis, decreased oligodendrocytes and myelin loss in subcortical white matter were evident at 1 week, and persisted until at least 7 weeks, following mild respiratory SARS-CoV-2 infection in mice. Taken together, the findings presented here illustrate striking similarities between neuropathophysiology after cancer therapy and after SARS-CoV-2 infection, and elucidate cellular deficits that may contribute to lasting neurological symptoms following even mild SARS-CoV-2 infection.

SMARCB1 deletion in atypical teratoid rhabdoid tumors results in human endogenous retrovirus K (HML-2) expression.

Atypical Teratoid Rhabdoid Tumor (AT/RT) is a rare pediatric central nervous system cancer often characterized by deletion or mutation of SMARCB1, a tumor suppressor gene. In this study, we found that SMARCB1 regulates Human Endogenous Retrovirus K (HERV-K, subtype HML-2) expression. HML-2 is a repetitive element scattered throughout the human genome, encoding several intact viral proteins that have been associated with stem cell maintenance and tumorigenesis. We found HML-2 env expression in both the intracellular and extracellular compartments in all AT/RT cell lines (n = 4) and in 95% of AT/RT patient tissues (n = 37) evaluated. SMARCB1 knock-down in neural stem cells (NSCs) led to an upregulation of HML-2 transcription. We found that SMARCB1 binds adjacent to the HML-2 promoter, repressing its transcription via chromatin immunoprecipitation; restoration of SMARCB1 expression in AT/RT cell lines significantly downregulated HML-2 expression. Further, targeted downregulation of HML-2 transcription via CRISPR-dCas9 coupled with suppressor proteins led to cellular dispersion, decreased proliferation, and cell death in vitro. HML-2 knock-down with shRNA, siRNA, and CRISPR-dCas9 significantly decreased Ras expression as measured by qRT-PCR, suggesting that HML-2 modulates MAPK/ERK signaling in AT/RT cells. Overexpression of NRAS was sufficient to restore cellular proliferation, and MYC, a transcription factor downstream of NRAS, was bound to the HERV-K LTR significantly more in the absence of SMARCB1 expression in AT/RT cells. We show a mechanism by which these undifferentiated tumors remain pluripotent, and we demonstrate that their formation is aided by aberrant HML-2 activation, which is dependent on SMARCB1 and its interaction with MYC.

Chronic Dengue Virus Panencephalitis in a Patient with Progressive Dementia with Extrapyramidal Features.

OBJECTIVE: To determine the underlying etiology in a patient with progressive dementia with extrapyramidal signs and chronic inflammation referred to the National Institutes of Health Undiagnosed Diseases Program. METHODS: Extensive investigations included metabolic profile, autoantibody panel, infectious etiologies, genetic screening, whole exome sequencing, and the phage-display assay, VirScan, for viral immune responses. An etiological diagnosis was established postmortem. RESULTS: Using VirScan, enrichment of dengue viral antibodies was detected in cerebrospinal fluid as compared to serum. No virus was detected in serum or cerebrospinal fluid, but postmortem analysis confirmed dengue virus in the brain by immunohistochemistry, in situ hybridization, quantitative polymerase chain reaction, and sequencing. Dengue virus was also detectable by polymerase chain reaction and sequencing from brain biopsy tissue collected 33 months antemortem, confirming a chronic infection despite a robust immune response directed against the virus. Immunoprofiling and whole exome sequencing of the patient did not reveal any immunodeficiency, and sequencing of the virus demonstrated wild-type dengue virus in the central nervous system. INTERPRETATION: Dengue virus is the most common arbovirus worldwide and represents a significant public health concern. Infections with dengue virus are usually self-limiting, and chronic dengue infections have not been previously reported. Our findings suggest that dengue virus infections may persist in the central nervous system causing a panencephalitis and should be considered in patients with progressive dementia with extrapyramidal features in endemic regions or with relevant travel history. Furthermore, this work highlights the utility of comprehensive antibody profiling assays to aid in the diagnosis of encephalitis of unknown etiology. ANN NEUROL 2019;86:695-703.

Comparison of Laparoscopic Cornual Resection and Cornuotomy for Interstitial Pregnancy.

STUDY OBJECTIVE: To compare the clinical efficacy and safety of laparoscopic cornuotomy and cornual resection in the treatment of interstitial pregnancy. DESIGN: Retrospective chart review between 2006 and 2014 (Canadian Task Force classification II-2). SETTING: Two academic tertiary care hospitals. PATIENTS: Seventy-five patients with interstitial pregnancy treated by laparoscopy. MEASUREMENT AND MAIN RESULTS: In the 75 patients, 53 who underwent cornual resection and 22 who underwent cornuotomy, we evaluated operating time, changes in hemoglobin levels after surgery, the rate of major complications, and the incidence of persistent interstitial pregnancy. The mean operating time was significantly shorter for cornuotomy than for cornual resection (59.36 ± 19.32 minutes vs. 77.11 ± 23.97 minutes, respectively). Changes in hemoglobin level after the operation, rates of major complications, and the incidence of persistent interstitial pregnancy were not significantly different in the 2 surgery groups. CONCLUSION: Laparoscopic cornuotomy yielded clinical results comparable to those of cornual resection. Laparoscopic cornuotomy may reduce the time of operation, and had the same incidence of persistent interstitial pregnancy as cornual resection.

Topographical relationship of the greater palatine artery and the palatal spine. Significance for periodontal surgery.

AIM: The aims of this study were to (1) identify the branching pattern and course of the greater palatine artery (GPA), (2) carry out a morphological analysis of the palatal bony prominence that divides the medial and lateral grooves and (3) characterize the topographical relationships between these two structures. METHODS: Thirty-six hemimaxillae were studied with the aid of a surgical microscope to elucidate the GPA. A further 25 dry skulls were examined to establish the morphology of the palatal spine. RESULTS: The most common GPA branching pattern was type I (41.7%, 15 sides), which gave off the medial and canine branches after the bony prominence. The distances from the CEJ to the lateral branch of the GPA were 9.04 ± 2.93 mm (canine), 11.12 ± 1.89 mm (first premolar), 13.51 ± 2.08 mm (second premolar), 13.76 ± 2.86 mm (first molar) and 13.91 ± 2.20 mm (second molar). The palatal spine was frequently observed as the bony prominence (66.3%, 57 sides), and was located at 6.49 ± 1.76 mm from the greater palatine foramen, with a length of 10.42 ± 2.45 mm. There was no a correlation between the bony prominence shape and the GPA branching pattern. CONCLUSIONS: These results could provide the reference data regarding the topography of the GPA for periodontal surgery.

MicroRNA-205 suppresses the oral carcinoma oncogenic activity via down-regulation of Axin-2 in KB human oral cancer cell.

MicroRNA (miRNA) is a small noncoding RNA molecule, 19-25 nucleotides in length, which regulates several pathways including cell development, cell proliferation, carcinogenesis, apoptosis, etc. In this study, the over-expression of microRNA-205 (miR-205) increased the number of apoptotic cells by at least 4 times compared to the control. In addition, over-expressed miRNA in KB oral cancer cells triggered apoptosis via the caspase cascade, including the cleavage of caspase-9, caspase-7, caspase-3, and PARP. Flow cytometry showed that apoptotic cell death was increased significantly by 35.33% in KB oral cancer cells with over-expressed miR-205 compared to the control. The microarray data showed that axis inhibitor protein 2 (Axin2) was down-regulated in KB oral cancer cells transfected with miR-205. In addition, Axin2 was down-regulated by approximately 50% by over-expressed miR-205 at both the mRNA and protein levels. Interestingly, Axin2 was up-regulated in KB oral cancer compared to human normal oral keratinocytes. Furthermore, the cell cytotoxicity and apoptotic population of KB oral cancer cells were increased significantly after Axin2 siRNA transfection. These results suggest that Axin2 is might be as potential oncogene in KB oral cancer cells. The luciferase assay showed that over-expressed miR-205 in KB oral cancer cells suppressed AXIN2 expression through an interaction with its own binding site at AXIN2 3'UTR (64-92). These results suggest that miR-205 is a novel anti-oncogenic miRNA in KB oral cancer cells, and may have potential applications in oral cancer therapy.

Histomorphologic approach for the modiolus with reference to reconstructive and aesthetic surgery.

The modiolus is strongly associated with facial expression, beauty, and aging, and so it is often viewed as the main facial landmark, both functionally and aesthetically. This study examined the modiolus and the surrounding structures histomorphologically with the aim of providing useful information for reconstructive and aesthetic surgery. Nineteen embalmed cadavers (38 hemifaces; 8 males and 11 females; mean age at death, 66.9 years) were examined in this study. For macroscopic observations, the modiolus and facial artery in the perioral region of 28 hemifaces were revealed by meticulous dissection. The modiolus and its surrounding structures were then prepared from 12 hemifaces for routine histology and stained with hematoxylin-eosin and Masson trichrome. A tendinous tissue nodule in the modiolus was found in 21.4% of cases (ie, 6 hemifaces). The facial artery passed approximately 1 mm lateral to the lateral border of the modiolus. In the central region of modiolus, which was an area of convergence of muscle fibers, the tendinous structure appeared as dense irregular collagenous connective tissue. Particularly in the middle layer between the skin and the oral mucosa, it appeared as a dense, compact, and prominent shape horizontally. The finding of the existence of a tendinous structure in the central region of the modiolus, which could act as an anchor for the converging facial muscles, is expected to provide critical information in the field of facial plastic surgery.

Histomorphometric analysis of the palatal mucosa associated with periodontal plastic surgery on cadavers.

PURPOSE: The palatal mucosa is a major donor site for connective tissue in the field of periodontal plastic surgery, since it satisfies both the esthetic and functional demands of patients. The purpose of this study was to use histomorphometric analysis to measure the thicknesses of the palatal mucosa and the lamina propria including the epithelium on cadavers. METHODS: Thirty-four hemimaxillae of cadavers were examined (13 male and 4 female, mean age 57.2 years). Each maxilla was processed for histological sectioning and subsequently for histomorphometric analysis. The thicknesses of the palatal mucosa and the lamina propria including the epithelium were measured at three points starting from the alveolar crest, at intervals of 4 mm, with the aid of Adobe Photoshop. RESULTS: The thickness of the palatal mucosa at the alveolar crest and at 4 and 8 mm below the alveolar crest were 2.51 ± 0.83 (mean ± SD), 2.92 ± 0.80, and 3.62 ± 0.99 mm, respectively, and thus increasing from the alveolar crest toward the midpalatal suture. Conversely, the thicknesses of the lamina propria including the epithelium at these same positions were 2.06 ± 0.70, 1.54 ± 0.48, and 1.28 ± 0.46 mm, respectively, thus decreasing toward the midpalatal suture. CONCLUSIONS: The present results indicate that clinicians need to be particularly careful when harvesting palatal mucosa that is destined to be used as autogenous donor material for connective tissue in periodontal plastic surgery.

MicroRNA-205 directly regulates the tumor suppressor, interleukin-24, in human KB oral cancer cells.

MicroRNA (miRNA) is a form of small noncoding RNA that regulates the expression of genes either by inhibiting mRNA translation or by inducing its degradation. Small microRNA play important roles in regulating a large number of cellular processes, including development, proliferation and apoptosis. This study examined the biological functions of miR-205 as a tumor suppressor in KB oral cancer cells. The results showed that miR-205 expression was significantly lower in KB oral cancer cells than in human normal oral keratinocytes. Furthermore, the miR-205 over-expressed in KB oral cancer cells increased the cell cytotoxicity and induced apoptosis through the activation of caspase-3/-7. The transfection of miR-205 into KB oral cancer cells strongly induced IL-24, a well known cytokine that acts as a tumor suppressor in a range of tumor tissues. In addition, miR-205 targeted the IL-24 promoter directly to induce gene expression. Overall, miR-205 has significant therapeutic potential to turn on silenced tumor suppressor genes by targeting them with miRNA.

Amygdalin suppresses lipopolysaccharide-induced expressions of cyclooxygenase-2 and inducible nitric oxide synthase in mouse BV2 microglial cells.

BACKGROUND: Amygdalin (D-mandelonitrile-beta-D-gentiobioside) is a cynogenic compound found in sweet and bitter almonds, Persicae semen and Armeniacae semen. Amygdalin has been used for the treatment of cancers and for the relief of the pain. We made an aqueous extraction of amygdalin from Armeniacae semen. In this study, the effect of amygdalin on the lipopolysaccharide (LPS)-induced inflammation was investigated. METHODS: The effects of amygdalin extracted from Armeniacae semen on the LPS-stimulated mRNA expressions of cyclooxygenase (COX)-1, COX-2 and inducible nitric oxide synthase (iNOS) in the mouse BV2 microglial cells were investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, reverse transcription-polymerase chain reaction (RT-PCR). The effects of amygdalin on the prostaglandins E(2) synthesis and the nitric oxide production were also studied by performing prostaglandins E(2) immunoassay and by detecting nitric oxide. RESULTS: The present results showed that amygdalin suppressed the prostaglandin E(2) synthesis and the nitric oxide production by inhibiting the LPS-stimulated mRNA expressions of COX-2 and iNOS in the mouse BV2 cells. CONCLUSION: These results show that amygdalin exerts anti-inflammatory and analgesic effects and it dose so probably by suppressing the mRNA expressions of COX-2 and iNOS.

Amygdalin induces apoptosis through regulation of Bax and Bcl-2 expressions in human DU145 and LNCaP prostate cancer cells.

Prostate cancer is one of the most common non-skin cancers in men. Amygdalin is one of the nitrilosides, natural cyanide-containing substances abundant in the seeds of plants of the prunasin family that have been used to treat cancers and relieve pain. In particular, D-amygdalin (D-mandelonitrile-beta-D-gentiobioside) is known to exhibit selective killing effect on cancer cells. Apoptosis, programmed cell death, is an important mechanism in cancer treatment. In the present study, we prepared the aqueous extract of the amygdalin from Armeniacae semen and investigated whether this extract induces apoptotic cell death in human DU145 and LNCaP prostate cancer cells. In the present results, DU145 and LNCaP cells treated with amygdalin exhibited several morphological characteristics of apoptosis. Treatment with amygdalin increased expression of Bax, a pro-apoptotic protein, decreased expression of Bcl-2, an anti-apoptotic protein, and increased caspase-3 enzyme activity in DU145 and LNCaP prostate cancer cells. Here, we have shown that amygdalin induces apoptotic cell death in human DU145 and LNCaP prostate cancer cells by caspase-3 activation through down-regulation of Bcl-2 and up-regulation of Bax. The present study reveals that amygdalin may offer a valuable option for the treatment of prostate cancers.

Melatonin attenuates amyloid beta25-35-induced apoptosis in mouse microglial BV2 cells.

Melatonin has been reported to possess strong antioxidant actions, and is able to directly scavenge a variety of reactive oxygen species (ROS). The present study investigated whether melatonin possesses protective effects against Abeta-induced cytotoxicity in microglial cells. Cells treated with Abeta exhibited several characteristic features of apoptosis, while cells pre-treated with melatonin prior to exposure to Abeta showed a decrease in the occurrence of such apoptotic features. Several previous studies have demonstrated the involvement of ROS in Abeta-induced neurotoxicity, and ROS generated by Abeta have been reported to lead to the activation of nuclear factor-kappa B (NF-kappaB), a transcription factor; pre-treatment with melatonin in the present study reduced the level of Abeta-induced intracellular ROS generation, inhibited NF-kappaB activation, and suppressed the Abeta-induced increase in caspase-3 enzyme activity. In addition, it was found that pre-treatment with melatonin inhibits Abeta-induced increase in the levels of bax mRNA and that it enhances the level of bcl-2 expression. Based on these findings, the authors speculate that melatonin may provide an effective means of treatment for Alzheimer's disease through attenuation of Abeta-induced apoptosis.

Nitric oxide induces apoptosis in mouse C2C12 myoblast cells.

To investigate whether nitric oxide (NO) induces apoptosis in myoblast cells, the effect of the sodium nitroprusside (SNP), NO donor, on the apoptosis of mouse C2C12 myoblast cells was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry, 4,6-diamidino-2-phenylindole (DAPI) staining, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay, DNA fragmentation assay, reverse transcription-polymerase chain reaction (RT-PCR), Western blot analysis, and caspase-3 enzyme assay. Mouse C2C12 myoblast cells treated with SNP exhibited several apoptotic features. SNP increased p53 expression and bax expression. SNP also enhanced caspase-3 enzyme activity. The data show that NO may induce apoptotic cell death in myoblast cells through the activation of p53-, bax-, and caspase-dependent intracellular death-related pathways.

Influence of maternal alcohol administration on c-Fos expression in the hippocampus of infant rats.

Maternal alcohol consumption during pregnancy is known to have a detrimental effect on the development of the fetus and its central nervous system (CNS) in particular. In the present study, the dose-dependence of the effect of maternal alcohol on hippocampal c-Fos expression, which is a marker of hippocampal neuronal activity and which is induced by a variety of stimuli, was examined in infant rats. In the present study, it was shown that expression of c-Fos in the hippocampus is decreased following treatment with alcohol in a dose-dependent fashion. Based on the results of the present study and the findings of other studies, it can be suggested that suppression of c-Fos expression in the hippocampus of infant rats with maternal alcohol administration mediates the associated developmental retardation and/or anomalies.

Naloxone potentiates treadmill running-induced increase in c-Fos expression in rat hippocampus.

The expression of c-Fos is induced by a variety of stimuli and is sometimes used as a marker for increased neuronal activity. In the present study, the effect of treadmill running on c-Fos expression in the hippocampus and the involvement of opioid receptors were investigated via c-Fos immunohistochemistry. It was shown that c-Fos expression in the CA1 region, the CA2 and CA3 regions, and the dentate gyrus of the hippocampus was significantly increased by treadmill running and naloxone, a nonselective opioid receptors antagonist, treatment enhanced treadmill exercise-induced increase of hippocampal c-Fos expression. Base on the present results, it can be suggested that treadmill running increases hippocampal neuronal activity and that endogenous opioids curtail the exercise-induced increase.