Clinical characteristics and survival analysis of cutaneous metastases in a single tertiary centre in Korea.

BACKGROUND: Cutaneous metastasis (CM) refers to the spread of malignancy to the skin. CM is perceived as an advanced stage. It might be the first sign of a primary cancer or an indicator of recurrence. OBJECTIVES: To identify primary cancers associated with CMs and perform a survival analysis according to advanced stage of cutaneous metastasis at a single tertiary centre in Korea. METHODS: A total of 219 patients from Samsung Medical Center from January 2009 to April 2020 were retrospectively analysed to identify cases with biopsy-proven CMs. According to advanced stage of metastasis, patients were divided into three stages, CM only (CMO), CM with lymph node metastasis (CM/LM) and CM with distant metastasis (CM/DM), to analyse clinical characteristics and survival rate. RESULTS: The most common CM from primary cancer was breast cancer, followed by lung cancer, stomach cancer, colorectal cancer and others. When all primary cancers were included, the median survival period was 4.82 years for the CMO stage, 2.15 years for the CM/LM stage and 0.80 years for the CM/DM stage, with a tendency to deteriorate with advancing stage. At 1- and 3-year after occurrence of CM, the CM/DM stage showed a significantly poorer survival rate than the other two stages. CONCLUSIONS: This study showed a median survival period of 22 months for CM patients overall. Breast cancer has greater accessibility to the skin than other cancers. Therefore, breast cancer can metastasize to the skin without involving lymph nodes or other sites.

Molecular characterization of onychomatricoma: Spatial profiling reveals the role of onychofibroblasts in its pathogenesis.

Onychomatricoma (OM) is a rare nail unit tumour with a characteristic presentation of finger-like projections arising from the nail matrix. Due to the lack of transcriptome information, the mechanisms underlying its development are largely unknown. To characterize molecular features involved in the disease pathogenesis, we used digital spatial profiling (DSP) in 2 cases of OM and normal control nail units. Based on the histological evaluation, we selectively profiled 69 regions of interest covering epithelial and stromal compartments of each tissue section. Dermoscopic and histopathologic findings were reviewed in 6 cases. Single-cell RNA sequencing of nail units and DSP were combined to define cell type contributions of OM. We identified 173 genes upregulated in stromal compartments of OM compared to onychodermis, specialized nail mesenchyme. Gene ontology analysis of the upregulated genes suggested the role of Wnt pathway activation in OM pathogenesis. We also found PLA2G2A, a known modulator of Wnt signalling, is strongly and specifically expressed in the OM stroma. The potential role of Wnt pathway was further supported by strong nuclear localization of ß-catenin in OM. Compared to the nail matrix epithelium, only a few genes were increased in OM epithelium. Deconvolution of nail unit cell types showed that onychofibroblasts are the dominant cell type in OM stroma. Altogether, integrated spatial and single-cell multi-omics concluded that OM is a tumour that derives a significant proportion of its origin from onychofibroblasts and is associated with upregulation of Wnt signals, which play a key role in the disease pathogenesis.

A distinct astrocyte subtype in the aging mouse brain characterized by impaired protein homeostasis.

The aging brain exhibits a region-specific reduction in synapse number and plasticity. Although astrocytes play central roles in regulating synapses, it is unclear how changes in astrocytes contribute to age-dependent cognitive decline and vulnerability to neurodegenerative diseases. Here, we identified a unique astrocyte subtype that exhibits dysregulated autophagy and morphology in aging hippocampus. In these autophagy-dysregulated astrocytes (APDAs), autophagosomes abnormally accumulate in swollen processes, impairing protein trafficking and secretion. We found that reduced mammalian target of rapamycin (mTOR) and proteasome activities with lysosomal dysfunction generate APDAs in an age-dependent manner. Secretion of synaptogenic molecules and astrocytic synapse elimination were significantly impaired in APDAs, suggesting that APDAs have lost their ability to control synapse number and homeostasis. Indeed, excitatory synapses and dendritic spines associated with APDAs were significantly reduced. Finally, we found that mouse brains with Alzheimer's disease showed a significantly accelerated increase in APDAs, suggesting potential roles for APDAs in age- and Alzheimer's disease-related cognitive decline and synaptic pathology.

Cerebellar 5HT-2A receptor mediates stress-induced onset of dystonia.

Stress is a key risk factor for dystonia, a debilitating motor disorder characterized by cocontractions of muscles leading to abnormal body posture. While the serotonin (5HT) system is known to control emotional responses to stress, its role in dystonia remains unclear. Here, we reveal that 5HT neurons in the dorsal raphe nuclei (DRN) send projections to the fastigial deep cerebellar nuclei (fDCN) and that photostimulation of 5HT-fDCN induces dystonia in wild-type mice. Moreover, we report that photoinhibition of 5HT-fDCN reduces dystonia in a1A tot/tot mice, a genetic model of stress-induced dystonia, and administration of a 5HT-2A receptor inverse agonist (MDL100907; 0.1 to 1 mg/kg) or shRNA-mediated knockdown of the ht2ar gene in fDCN can notably reduce the onset of dystonia in a1A tot/tot mice. These results support the serotonin theory of dystonia and suggest strategies for alleviating symptoms in human patients by blocking 5HT-2A receptors.

Usefulness of Endoscopic Hill Grade in Evaluating Children Suspected of Having Gastroesophageal Reflux Disease

Background/Aims@#This study aim to evaluate the relationship between the Hill grade confirmed by esophagogastroduodenoscopy (EGD) and the degree of gastroesophageal reflux (GER) by 24-hour multichannel intraluminal impedance-pH monitoring (MII-pH) in children suspected of having gastroesophageal reflux disease (GERD). @*Methods@#A retrospective review of 105 children and adolescents who underwent EGD and MII-pH for the evaluation of GERD from March 2013 to July 2019 was performed. Clinical features and results of EGD and 24-hour MII-pH were collected and statistically analyzed. @*Results@#Hill grades 1, 2, 3, and 4 were identified using EGD in 56 (53.3%), 22 (22.0%), 16 (15.2%), and 11 (10.5%) patients, respectively. As the Hill grade increased, the proportion of neurological diseases (P < 0.001) and endoscopic erosive esophagitis (P < 0.001) increased significantly. The acid exposure index, bolus exposure index, number of reflux episodes, and number of GER reaching proximal extent on MII-pH increased significantly as the endoscopic Hill grade increased (all P < 0.001). Linear regression analysis revealed an increase in the Hill grade by 1 increased the acid exposure index by 2.0%, bolus exposure index by 0.7%, number of reflux episodes by 18.9 episodes, and the number of GER reaching the proximal esophagus increased by 10.5 episodes on average (all P < 0.001). @*Conclusions@#Hill grade on EGD was associated with GER in children. Estimating the degree of GER by applying Hill grade in the retroflexion view may be useful in practice when evaluating children suspected with GERD.

Usefulness of Endoscopic Hill Grade in Evaluating Children Suspected of Having Gastroesophageal Reflux Disease

Background/Aims@#This study aim to evaluate the relationship between the Hill grade confirmed by esophagogastroduodenoscopy (EGD) and the degree of gastroesophageal reflux (GER) by 24-hour multichannel intraluminal impedance-pH monitoring (MII-pH) in children suspected of having gastroesophageal reflux disease (GERD). @*Methods@#A retrospective review of 105 children and adolescents who underwent EGD and MII-pH for the evaluation of GERD from March 2013 to July 2019 was performed. Clinical features and results of EGD and 24-hour MII-pH were collected and statistically analyzed. @*Results@#Hill grades 1, 2, 3, and 4 were identified using EGD in 56 (53.3%), 22 (22.0%), 16 (15.2%), and 11 (10.5%) patients, respectively. As the Hill grade increased, the proportion of neurological diseases (P < 0.001) and endoscopic erosive esophagitis (P < 0.001) increased significantly. The acid exposure index, bolus exposure index, number of reflux episodes, and number of GER reaching proximal extent on MII-pH increased significantly as the endoscopic Hill grade increased (all P < 0.001). Linear regression analysis revealed an increase in the Hill grade by 1 increased the acid exposure index by 2.0%, bolus exposure index by 0.7%, number of reflux episodes by 18.9 episodes, and the number of GER reaching the proximal esophagus increased by 10.5 episodes on average (all P < 0.001). @*Conclusions@#Hill grade on EGD was associated with GER in children. Estimating the degree of GER by applying Hill grade in the retroflexion view may be useful in practice when evaluating children suspected with GERD.

Distinct dual roles of p-Tyr42 RhoA GTPase in tau phosphorylation and ATP citrate lyase activation upon different Aß concentrations.

Both the accumulation of Amyloid-ß (Aß) in plaques and phosphorylation of Tau protein (p-Tau) in neurofibrillary tangles have been identified as two major symptomatic features of Alzheimer's disease (AD). Despite of critical role of Aß and p-Tau in AD progress, the interconnection of signalling pathways that Aß induces p-Tau remains elusive. Herein, we observed that a popular AD model mouse (APP/PS1) and Aß-injected mouse showed an increase in p-Tyr42 Rho in hippocampus of brain. Low concentrations of Aß (1 µM) induced RhoA-mediated Ser422 phosphorylation of Tau protein (p-Ser422 Tau), but reduced the expression of ATP citrate lyase (ACL) in the HT22 hippocampal neuronal cell line. In contrast, high concentrations of Aß (10 µM) along with high levels of superoxide production remarkably attenuated accumulation of p-Ser422 Tau, but augmented ACL expression and activated sterol regulatory element-binding protein 1 (SREBP1), leading to cellular senescence. Notably, a high concentration of Aß (10 µM) induced nuclear localization of p-Tyr42 Rho, which positively regulated NAD kinase (NADK) expression by binding to the NADK promoter. Furthermore, severe AD patient brain showed high p-Tyr42 Rho levels. Collectively, our findings indicate that both high and low concentrations of Aß are detrimental to neurons via distinct two p-Tyr42 RhoA-mediated signalling pathways in Ser422 phosphorylation of Tau and ACL expression.

Fecal Calprotectin as a Useful Non-Invasive Screening Marker for Eosinophilic Gastrointestinal Disorder in Korean Children

Background@#Eosinophilic gastrointestinal disorder (EoGID) is an emerging disease condition in Korean children, but its diagnosis requires invasive endoscopic biopsies. Fecal calprotectin (FCal) is a noninvasive biomarker for intestinal inflammation to differentiate organic gastrointestinal diseases from functional abdominal pain disorder. This study aimed to evaluate the diagnostic accuracy of FCal and to determine the optimal cutoff to differentiate EoGID from functional abdominal pain disorder. @*Methods@#A total of 253 children (122 boys, 131 girls; mean age 12.2 ± 3.6, range 2.9–17.8 years) who underwent endoscopy with biopsies for chronic gastrointestinal symptoms were recruited, except for 38 children diagnosed with inflammatory bowel disease, and divided into EoGID (n = 67) and functional abdominal pain disorder (n = 186). FCal, white blood cell (WBC) counts, eosinophil counts, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) levels were measured in all subjects at initial diagnosis. @*Results@#FCal levels weakly correlated with WBC (r = 0.127, P = 0.044) and CRP (r = 0.126, P = 0.040) but not with ESR and eosinophil count. FCal levels were significantly higher in the EoGID group than in the functional abdominal pain disorder group (mean 179.5 ± 242.9 mg/kg vs. 44.3 ± 68.1 mg/kg; P 0.05). An optimal cutoff of FCal 73.2 mg/kg distinguished EoGID from functional abdominal pain disorder with a sensitivity of 50.7% and a specificity of 84.6%. @*Conclusion@#FCal is a useful and reliable noninvasive marker for differentiating EoGID from functional abdominal pain disorder in Korean children with chronic gastrointestinal symptoms when optimal cutoffs are applied.

The recovery from transient cognitive dysfunction induced by propofol was associated with enhanced autophagic flux in normal healthy adult mice.

Propofol is the most widely accepted intravenous anesthetic available for clinical use. However, neurotoxicity of propofol in the developing brain has been reported. This study investigated the effects of propofol on cognitive function in normal healthy adult mice. Thirty-three GFP-LC3 adult mice were included. Propofol was injected for anesthesia (n = 22). The sham control (n = 11) received intralipid injections. The mice completed a Y-maze test on 3 and 7 days after being anesthetized. Western blotting, immunofluorescence staining, and transmission electron microscopic (TEM) analyses were performed with their hippocampi. In addition, we conducted a separate ex vivo experiment using organotypic hippocampal slice cultures (OHSCs) to investigate the effects of propofol on induced autophagy. There was a significantly lower percentage of alternation in the Y-maze test on day 3 after propofol anesthesia than the control, but no difference was observed on day 7. Western blot analyses and immunofluorescence assays showed that the levels of cognitive function-related proteins significantly decreased in the propofol group compared to the control on day 3 but had recovered by day 7. In terms of autophagy-related proteins, western blot analyses and immunofluorescence assays showed that propofol increased autophagic induction, flux, and degradation of autophagosomes. Ex vivo experiments showed that propofol enhanced autophagic flux of the induced autophagy. In conclusion, although transient cognitive dysfunction occurred, adult mice recovered their cognitive function after the administration of propofol anesthesia. And this finding may be associated with enhanced autophagic flux.

Phagocytic Roles of Glial Cells in Healthy and Diseased Brains.

Glial cells are receiving much attention since they have been recognized as important regulators of many aspects of brain function and disease. Recent evidence has revealed that two different glial cells, astrocytes and microglia, control synapse elimination under normal and pathological conditions via phagocytosis. Astrocytes use the MEGF10 and MERTK phagocytic pathways, and microglia use the classical complement pathway to recognize and eliminate unwanted synapses. Notably, glial phagocytosis also contributes to the clearance of disease-specific protein aggregates, such as ß-amyloid, huntingtin, and α-synuclein. Here we reivew recent findings showing that glial cells are active regulators in brain functions through phagocytosis and that changes in glial phagocytosis contribute to the pathogenesis of various neurodegenerative diseases. A better understanding of the cellular and molecular mechanisms of glial phagocytosis in healthy and diseased brains will greatly improve our current approach in treating these diseases.

The Efficacy of Treatment According to Electroencephalogram Findings in Children and Adolescents with Recurrent Primary Headache / 대한소아신경학회지

PURPOSE: We investigated the impact of treatment on electroencephalogram (EEG) findings, and determined treatment efficacy according to EEG findings and antiepileptic drugs in children and adolescents with recurrent headaches. METHODS: We retrospectively analyzed the medical records of 131 patients, aged 5–18 years, with recurrent primary headaches and performed EEG study who visited the Chosun University Hospital Department of Pediatrics from January 2014 to December 2016. Headaches were classified according to the International Classification of Headache Disorders-III (ICHD-III, beta version), and EEGs were analyzed for changes after treatment for primary headache. RESULTS: Among 131 patients, we successfully collected completed all the data on 30 patients (18 boys, 12 girls). The frequency of abnormal EEG findings before treatment was not significantly different according to the type of primary headache (P= 0.390). The mean frequency (P=0.001), duration (P=0.002), and intensity of headaches (P < 0.001), and disability due to headache (P=0.003) were significantly decreased after treatment in patients with epileptiform discharges on EEG. The mean frequency and intensity of headaches and disability due to headache (P < 0.005) was also significantly decreased in the patients with both slow and normal EEG findings. The mean frequency (P=0.007), duration (P=0.01), and intensity (P < 0.001) of headaches, and disability due to headache (P=0.002) were significantly decreased after treatment with antiepileptic drugs in patients with epileptiform discharges. CONCLUSION: Abnormal EEG findings were no significant differences in terms of type of primary headaches. Our results suggest that antiepileptic drugs may alleviate headaches in patients with epileptiform discharges on EEG.

Characterization and Predictors of Headache-Related Disability among School Children: A Population-Based Study / 대한소아신경학회지

PURPOSE: Headache is a frequent neurological symptom in school aged individuals and recurrent headache has significant disabling effects among children and adolescents that manifest as school absenteeism, decreased extracurricular activities, and poor academic performance, as shown in previous studies. In Korea, there has not yet been a population-based study of headache-related disability in children and adolescents. We sought to estimate headache-related disability and investigate relevant predictors of disability due to headaches among schoolchildren in South Korea. METHODS: This was a cross-sectional school-based study. We surveyed 5,039 (boys 2,405, girls 2,634) students aged 6-18 years. Among 1,465 students with headache, six hundred sixty-six schoolchildren (225 boys, 441 girls) completed all questionnaires. The questionnaires collected demographic data, in addition to headache specific questions consistent with International Classification of Headache Disorder criteria, 2nd edition. Disability was evaluated using the 6-question Pediatric Migraine Disability Assessment (PedMIDAS). RESULTS: Six hundred sixty six school children and adolescents (225 boys, 441 girls) among 1,465 students with headaches completed all questionnaires. The percentage of headache sufferers with grade I disability was 88.6%. The mean (±standard deviation) PedMIDAS score was 5.11±11.17. There was a trend towards more severe disability in the older age groups, particularly among the 16 to18 year-olds. Students with migraine had the highest PedMIDAS scores (6.69±10.66) whereas students reporting other types of headache had the lowest scores (3.81±7.52). The predictors of headache-related disability were intensity (P=0.028), frequent headache (P=0.003), and longer duration of symptoms prior to presentation (P=0.008). CONCLUSION: A trend towards a more severe disability was observed in the older age group. Schoolchildren with migraine had the most headache-related disability. The predictors for headache-related disability were intensity, frequent headache, and longer duration of symptoms prior to presentation.

Characterization and Predictors of Headache-Related Disability among School Children: A Population-Based Study / 대한소아신경학회지

PURPOSE: Headache is a frequent neurological symptom in school aged individuals and recurrent headache has significant disabling effects among children and adolescents that manifest as school absenteeism, decreased extracurricular activities, and poor academic performance, as shown in previous studies. In Korea, there has not yet been a population-based study of headache-related disability in children and adolescents. We sought to estimate headache-related disability and investigate relevant predictors of disability due to headaches among schoolchildren in South Korea. METHODS: This was a cross-sectional school-based study. We surveyed 5,039 (boys 2,405, girls 2,634) students aged 6-18 years. Among 1,465 students with headache, six hundred sixty-six schoolchildren (225 boys, 441 girls) completed all questionnaires. The questionnaires collected demographic data, in addition to headache specific questions consistent with International Classification of Headache Disorder criteria, 2nd edition. Disability was evaluated using the 6-question Pediatric Migraine Disability Assessment (PedMIDAS). RESULTS: Six hundred sixty six school children and adolescents (225 boys, 441 girls) among 1,465 students with headaches completed all questionnaires. The percentage of headache sufferers with grade I disability was 88.6%. The mean (±standard deviation) PedMIDAS score was 5.11±11.17. There was a trend towards more severe disability in the older age groups, particularly among the 16 to18 year-olds. Students with migraine had the highest PedMIDAS scores (6.69±10.66) whereas students reporting other types of headache had the lowest scores (3.81±7.52). The predictors of headache-related disability were intensity (P=0.028), frequent headache (P=0.003), and longer duration of symptoms prior to presentation (P=0.008). CONCLUSION: A trend towards a more severe disability was observed in the older age group. Schoolchildren with migraine had the most headache-related disability. The predictors for headache-related disability were intensity, frequent headache, and longer duration of symptoms prior to presentation.

Induction of Angiogenesis by Matrigel Coating of VEGF-Loaded PEG/PCL-Based Hydrogel Scaffolds for hBMSC Transplantation.

hBMSCs are multipotent cells that are useful for tissue regeneration to treat degenerative diseases and others for their differentiation ability into chondrocytes, osteoblasts, adipocytes, hepatocytes and neuronal cells. In this study, biodegradable elastic hydrogels consisting of hydrophilic poly(ethylene glycol) (PEG) and hydrophobic poly(ε-caprolactone) (PCL) scaffolds were evaluated for tissue engineering because of its biocompatibility and the ability to control the release of bioactive peptides. The primary cultured cells from human bone marrow are confirmed as hBMSC by immunohistochemical analysis. Mesenchymal stem cell markers (collagen type I, fibronectin, CD54, integrin1ß, and Hu protein) were shown to be positive, while hematopoietic stem cell markers (CD14 and CD45) were shown to be negative. Three different hydrogel scaffolds with different block compositions (PEG:PCL=6:14 and 14:6 by weight) were fabricated using the salt leaching method. The hBMSCs were expanded, seeded on the scaffolds, and cultured up to 8 days under static conditions in Iscove's Modified Dulbecco's Media (IMDM). The growth of MSCs cultured on the hydrogel with PEG/PCL= 6/14 was faster than that of the others. In addition, the morphology of MSCs seemed to be normal and no cytotoxicity was found. The coating of the vascular endothelial growth factor (VEGF) containing scaffold with Matrigel slowed down the release of VEGF in vitro and promoted the angiogenesis when transplanted into BALB/c nude mice. These results suggest that hBMSCs can be supported by a biode gradable hydrogel scaffold for effective cell growth, and enhance the angiogenesis by Matrigel coating.

Knockout of Toll-like receptor 2 attenuates Aß25-35-induced neurotoxicity in organotypic hippocampal slice cultures.

Toll-like receptors (TLRs), which have been implicated in various neuroinflammatory responses, are thought to act in defense mechanisms by inhibiting neuronal cell death in Alzheimer's disease. In this study, we evaluated the effects of TLR2 on amyloid beta peptide 25-35 (Aß25-35)-induced neuronal cell death, synaptic dysfunction, and microglial activation in organotypic hippocampal slice cultures (OHSCs) from wild-type (WT) C57BL/6 mice and TLR2-knockout (KO) mice. In WT mice, Aß25-35 induced ß-amyloid aggregation and surrounding TLR2 expression. And, propidium iodide (PI) uptake, which is a measure of cell death, increased in a dose-dependent manner in slices with Aß25-35 treatment. In the Aß25-35-treated TLR2-KO OHSCs, the PI uptake was significantly attenuated to the control level, indicating that the cells were less susceptible to Aß25-35-induced neuronal toxicity. In the ultrastructural analysis, nuclear shrinkage, slightly swollen mitochondria, and degraded organelles were detected in the Aß25-35-treated slices from WT mice but not in the Aß25-35-treated slices from TLR2-KO, suggesting the resistance of TLR2-KO to Aß25-35-induced neurotoxicity. In Aß25-35-treated OHSCs of WT mice, the levels of phosphorylated tau were increased and the levels of synaptophysin were decreased in a dose-dependent manner, but they were not changed in OHSCs of TLR2-KO mice. In WT mice, Aß25-35 increased total protein level and immunoreactivity of Iba-1, which was colocalized with TLR2. However, there were no significant changes in the slices of Aß25-35-treated TLR2-KO mice. These results suggested that TLR2 may play a role in Aß25-35-induced neuronal cell loss and synaptic dysfunction through the activation of microglia in OHSCs.

Oxygen/Glucose Deprivation and Reperfusion Cause Modifications of Postsynaptic Morphology and Activity in the CA3 Area of Organotypic Hippocampal Slice Cultures.

Brain ischemia leads to overstimulation of N-methyl-D-aspartate (NMDA) receptors, referred as excitotoxicity, which mediates neuronal cell death. However, less attention has been paid to changes in synaptic activity and morphology that could have an important impact on cell function and survival following ischemic insult. In this study, we investigated the effects of reperfusion after oxygen/glucose deprivation (OGD) not only upon neuronal cell death, but also on ultrastructural and biochemical characteristics of postsynaptic density (PSD) protein, in the stratum lucidum of the CA3 area in organotypic hippocampal slice cultures. After OGD/reperfusion, neurons were found to be damaged; the organelles such as mitochondria, endoplasmic reticulum, dendrites, and synaptic terminals were swollen; and the PSD became thicker and irregular. Ethanolic phosphotungstic acid staining showed that the density of PSD was significantly decreased, and the thickness and length of the PSD were significantly increased in the OGD/reperfusion group compared to the control. The levels of PSD proteins, including PSD-95, NMDA receptor 1, NMDA receptor 2B, and calcium/calmodulin-dependent protein kinase II, were significantly decreased following OGD/reperfusion. These results suggest that OGD/reperfusion induces significant modifications to PSDs in the CA3 area of organotypic hippocampal slice cultures, both morphologically and biochemically, and this may contribute to neuronal cell death and synaptic dysfunction after OGD/reperfusion.

Proteomic profiling of the epileptic dentate gyrus.

The development of epilepsy is often associated with marked changes in central nervous system cell structure and function. Along these lines, reactive gliosis and granule cell axonal sprouting within the dentate gyrus of the hippocampus are commonly observed in individuals with temporal lobe epilepsy (TLE). Here we used the pilocarpine model of TLE in mice to screen the proteome and phosphoproteome of the dentate gyrus to identify molecular events that are altered as part of the pathogenic process. Using a two-dimensional gel electrophoresis-based approach, followed by liquid chromatography-tandem mass spectrometry, 24 differentially expressed proteins, including 9 phosphoproteins, were identified. Functionally, these proteins were organized into several classes, including synaptic physiology, cell structure, cell stress, metabolism and energetics. The altered expression of three proteins involved in synaptic physiology, actin, profilin 1 and α-synuclein was validated by secondary methods. Interestingly, marked changes in protein expression were detected in the supragranular cell region, an area where robust mossy fibers sprouting occurs. Together, these data provide new molecular insights into the altered protein profile of the epileptogenic dentate gyrus and point to potential pathophysiologic mechanisms underlying epileptogenesis.

Downregulation of APE1/Ref-1 is involved in the senescence of mesenchymal stem cells.

The senescence of human mesenchymal stem cells (hMSCs) causes disruption of tissue and organ maintenance, and is thus an obstacle to stem cell-based therapies for disease. Although some researchers have studied changes in the characteristics of hMSCs (decreases in differentiation ability and self-renewal), comparing young and old ages, the mechanisms of stem cell senescence have not yet been defined. In this study, we developed a growth curve for human bone marrow derived MSCs (hBMSCs) which changes into a hyperbolic state after passage number 7. Senescence associated beta-galactosidase (SA beta-gal) staining of hBMSCs showed 10% in passage 9 and 45% in passage 11. We detected an increase in endogenous superoxide levels during senescence that correlated with senescence markers (SA beta-gal, hyperbolic growth curve). Interestingly, even though endogenous superoxide increased in a replicative senescence model, the expression of APE1/Ref-1, which is sensitive to intracellular redox state, decreased. These effects were confirmed in a stress-induced senescence model by exogenous treatment with H(2)O(2). This change is related to the p53 activity that negatively regulates APE1/Ref-1. p21 expression levels, which represent p53 activity, were transiently increased in passage 9, meaning that they correlated with the expression of APE1/Ref-1. Overexpression of APE1/Ref-1 suppressed superoxide production and decreased SA beta-gal in hBMSCs. In conclusion, intracellular superoxide accumulation appears to be the main cause of the senescence of hBMSCs, and overexpression of APE1/Ref-1 can rescue cells from the senescence phenotype. Maintaining characteristics of hBMSCs by regulating intracellular reactive oxygen species production can contribute to tissue regeneration and to improved cell therapy.

Expression regulation and function of Pref-1 during adipogenesis of human mesenchymal stem cells (MSCs).

Preadipocyte Factor 1 (Pref-1), also known as Delta-like Protein 1 (DLK-1) is an epidermal growth factor-like domain-containing trans-membrane protein that is involved in adipogenesis and cell fate decision. Its function in adipogenesis is reported inconsistently based on different cellular model systems. Here, by using human mesenchymal stem cells (MSCs), we show that Pref-1 is modulated by both dexamethasone and 3-isobutyl-1methylxanthine (IBMX), two components of the adipogenic induction mixture during the adipogenesis in vitro. IBMX induces the expression of Pref-1 in a time- and dose-dependent manner through cyclic AMP and cyclic GMP independent pathway and attenuates adipocyte differentiation by down-regulating PPARgamma (peroxisome proliferator activated receptor gamma) expression. Dexamethasone, on the other hand, is capable of subduing the inhibitory effect of IBMX-induced Pref-1 and initiating the adipogenesis by up-regulating PPARgamma expression. Moreover, the treatment of IBMX or dexamethasone alone fails to develop MSCs into mature adipocytes, however, treating cells with both IBMX and dexamethasone leads to a complete adipocyte differentiation as evaluated by lipid-droplet formation. Taken together, our study demonstrates that IBMX accelerates accumulation of lipid in MSCs only under the circumstance that the negative effect of Pref-1 induced by IBMX on the adipogenesis is overcome by dexamethasone.