Tweety-homolog (Ttyh) Family Encodes the Pore-forming Subunits of the Swelling-dependent Volume-regulated Anion Channel (VRAC(swell)) in the Brain

In the brain, a reduction in extracellular osmolality causes water-influx and swelling, which subsequently triggers Cl⁻- and osmolytes-efflux via volume-regulated anion channel (VRAC). Although LRRC8 family has been recently proposed as the pore-forming VRAC which is activated by low cytoplasmic ionic strength but not by swelling, the molecular identity of the pore-forming swelling-dependent VRAC (VRAC(swell)) remains unclear. Here we identify and characterize Tweety-homologs (TTYH1, TTYH2, TTYH3) as the major VRAC(swell) in astrocytes. Gene-silencing of all Ttyh1/2/3 eliminated hypo-osmotic-solution-induced Cl⁻ conductance (I(Cl,swell)) in cultured and hippocampal astrocytes. When heterologously expressed in HEK293T or CHO-K1 cells, each TTYH isoform showed a significant I(Cl,swell) with similar aquaporin-4 dependency, pharmacological properties and glutamate permeability as I(Cl,swell) observed in native astrocytes. Mutagenesis-based structure-activity analysis revealed that positively charged arginine residue at 165 in TTYH1 and 164 in TTYH2 is critical for the formation of the channel-pore. Our results demonstrate that TTYH family confers the bona fide VRAC(swell) in the brain.

14-3-3γ Haploinsufficient Mice Display Hyperactive and Stress-sensitive Behaviors

14-3-3γ plays diverse roles in different aspects of cellular processes. Especially in the brain where 14-3-3γ is enriched, it has been reported to be involved in neurological and psychiatric diseases (e.g. Williams-Beuren syndrome and Creutzfeldt-Jakob disease). However, behavioral abnormalities related to 14-3-3γ deficiency are largely unknown. Here, by using 14-3-3γ deficient mice, we found that homozygous knockout mice were prenatally lethal, and heterozygous mice showed developmental delay relative to wild-type littermate mice. In addition, in behavioral analyses, we found that 14-3-3γ heterozygote mice display hyperactive and depressive-like behavior along with more sensitive responses to acute stress than littermate control mice. These results suggest that 14-3-3γ levels may be involved in the developmental manifestation of related neuropsychiatric diseases. In addition, 14-3-3γ heterozygote mice may be a potential model to study the molecular pathophysiology of neuropsychiatric symptoms.

Transcriptome analyses of chronic traumatic encephalopathy show alterations in protein phosphatase expression associated with tauopathy

Chronic traumatic encephalopathy (CTE) is a progressive neurodegenerative disorder that is associated with repetitive head injury and has distinctive neuropathological features that differentiate this disease from other neurodegenerative diseases. Intraneuronal tau aggregates, although they occur in different patterns, are diagnostic neuropathological features of CTE, but the precise mechanism of tauopathy is not known in CTE. We performed whole RNA sequencing analysis of post-mortem brain tissue from patients with CTE and compared the results to normal controls to determine the transcriptome signature changes associated with CTE. The results showed that the genes related to the MAP kinase and calcium-signaling pathways were significantly downregulated in CTE. The altered expression of protein phosphatases (PPs) in these networks further suggested that the tauopathy observed in CTE involves common pathological mechanisms similar to Alzheimer's disease (AD). Using cell lines and animal models, we also showed that reduced PPP3CA/PP2B phosphatase activity is directly associated with increases in phosphorylated (p)-tau proteins. These findings provide important insights into PP-dependent neurodegeneration and may lead to novel therapeutic approaches to reduce the tauopathy associated with CTE.

Neuronal Expression and Cell-Type-Specific Gene-Silencing of Best1 in Thalamic Reticular Nucleus Neurons Using pSico-Red System

Assessing the cell-type expression pattern of a certain gene can be achieved by using cell-type-specific gene manipulation. Recently, cre-recombinase-dependent gene-silencing tool, pSico has become popular in neuroscientific research. However, pSico has a critical limitation that gene-silenced cell cannot be identified by fluorescence, due to an excision of the reporter gene for green fluorescence protein (GFP). To overcome this limitation, we newly developed pSico-Red, with mCherry gene as a reporter outside two loxP sites, so that red mCherry signal is detected in all transfected cells. When a cell expresses cre, GFP is excised and shRNA is enabled, resulting in disappearance of GFP. This feature of pSico-Red provides not only cell-type-specific gene-silencing but also identification of cre expressing cells. Using this system, we demonstrated for the first time the neuronal expression of the Bestrophin-1 (Best1) in thalamic reticular nucleus (TRN) and TRN-neuron-specific gene-silencing of Best1. We combined adeno-associated virus (AAV) carrying Best1-shRNA in pSico-Red vector and transgenic mouse expressing cre under the promoter of distal-less homeobox 5/6 (DLX5/6), a marker for inhibitory neurons. Firstly, we found that almost all of inhibitory neurons in TRN express Best1 by immunohistochemistry. Using pSico-Red virus, we found that 80% of infected TRN neurons were DLX5/6-cre positive but parvalbumin negative. Finally, we found that Best1 in DLX5/6-cre positive neurons were significantly reduced by Best1-shRNA. Our study demonstrates that TRN neurons strongly express Best1 and that pSico-Red is a valuable tool for cell-type-specific gene manipulation and identification of specific cell population.

Disinhibitory Action of Astrocytic GABA at the Perforant Path to Dentate Gyrus Granule Neuron Synapse Reverses to Inhibitory in Alzheimer's Disease Model

Like neurons, astrocytes produce and release GABA to influence neuronal signaling. At the perforant path to dentate gyrus granule neuron synapse, GABA from astrocyte was found to be a strong inhibitory factor, which impairs synaptic transmission, synaptic plasticity and memory in Alzheimer's disease. Although astrocytic GABA is observed in many brain regions, its physiological role has not been clearly demonstrated yet. Here, we show that astrocytic GABA exerts disinhibitory action to dentate granule neurons by targeting GABA(B) receptors of GABAergic interneurons in wild-type mice. This disinhibitory effect is specific to a low intensity of electrical stimulation at perforant path fibers. Inversely in Alzheimer's disease model mice, astrocytic GABA targets GABA(A) receptors and exerts inhibitory action by reducing release probability of glutamatergic perforant path terminals. These results suggest that astrocytic GABA differentially modulates the signaling from cortical input to dentate gyrus under physiological and pathological conditions.

CDK5-dependent inhibitory phosphorylation of Drp1 during neuronal maturation

Mitochondrial functions are essential for the survival and function of neurons. Recently, it has been demonstrated that mitochondrial functions are highly associated with mitochondrial morphology, which is dynamically changed by the balance between fusion and fission. Mitochondrial morphology is primarily controlled by the activation of dynamin-related proteins including dynamin-related protein 1 (Drp1), which promotes mitochondrial fission. Drp1 activity is regulated by several post-translational modifications, thereby modifying mitochondrial morphology. Here, we found that phosphorylation of Drp1 at serine 616 (S616) is mediated by cyclin-dependent kinase 5 (CDK5) in post-mitotic rat neurons. Perturbation of CDK5 activity modified the level of Drp1S616 phosphorylation and mitochondrial morphology in neurons. In addition, phosphorylated Drp1S616 preferentially localized as a cytosolic monomer compared with total Drp1. Furthermore, roscovitine, a chemical inhibitor of CDKs, increased oligomerization and mitochondrial translocation of Drp1, suggesting that CDK5-dependent phosphorylation of Drp1 serves to reduce Drp1's fission-promoting activity. Taken together, we propose that CDK5 has a significant role in the regulation of mitochondrial morphology via inhibitory phosphorylation of Drp1S616 in post-mitotic neurons.

A Novel Cytosolic Isoform of Mitochondrial Trans-2-Enoyl-CoA Reductase Enhances Peroxisome Proliferator-Activated Receptor alpha Activity

BACKGROUND: Mitochondrial trans-2-enoyl-CoA reductase (MECR) is involved in mitochondrial synthesis of fatty acids and is highly expressed in mitochondria. MECR is also known as nuclear receptor binding factor-1, which was originally reported with yeast two-hybrid screening as a binding protein of the nuclear hormone receptor peroxisome proliferator-activated receptor alpha (PPARalpha). However, MECR and PPARalpha are localized at different compartment, mitochondria, and the nucleus, respectively. Therefore, the presence of a cytosolic or nuclear isoform of MECR is necessary for functional interaction between MECR and PPARalpha. METHODS: To identify the expression pattern of MECR and the cytosolic form of MECR (cMECR), we performed reverse transcription polymerase chain reaction (RT-PCR) with various tissue samples from Sprague-Dawley rats. To confirm the interaction between cMECR and PPARalpha, we performed several binding assays such as yeast two-hybrid, coimmunoprecipitation, and bimolecular fluorescence complementation. To observe subcellular localization of these proteins, immunocytochemistry was performed. A luciferase assay was used to measure PPARalpha activity. RESULTS: We provide evidence of an alternatively spliced variant of the rat MECR gene that yields cMECR. The cMECR lacks the N-terminal 76 amino acids of MECR and shows uniform distribution in the cytoplasm and nucleus of HeLa cells. cMECR directly bound PPARalpha in the nucleus and increased PPARalpha-dependent luciferase activity in HeLa cells. CONCLUSION: We found the cytosolic form of MECR (cMECR) was expressed in the cytosolic and/or nuclear region, directly binds with PPARalpha, and enhances PPARalpha activity.

Association of infant feeding practices in the general population with infant growth and stool characteristics

This was a prospective cohort study of 976 infants from birth to 12 months of age. Infants were fed breast milk, goat infant formula, cow infant formula, or a combination of formula and breast milk during the first 4 months of age. Data on type of milk feeding and infant growth (weight and height) were collected at birth and at 4, 8, and 12 months during routine clinical assessment. The number and consistency of bowel motions per day were recorded based on observational data supplied by the mothers. Infants fed breast milk or goat or cow infant formula during the first 4 months displayed similar growth outcomes. More of the infants fed cow infant formula had fewer and more well-formed bowel motions compared with breast-fed infants. The stool characteristics of infants fed goat formula resembled those of infants fed breast milk.

Effects of Family History on the Occurrence of Atopic Dermatitis in Infants / 소아알레르기및호흡기학회지

PURPOSE: The prevalence of atopic dermatitis (AD) has been increased in Korea. We aim to investigate the risk factors for development of AD in infants, especially those factors related to the family history. METHODS: The data from 542 infants in our prospective birth cohort study were analyzed. The data from their parent were collected by questionnaires and skin prick tests. They were regularly followed up at 1 year of age when the presence of AD and allergen sensitization was determined. Various factors such as sex, cesarean section delivery, duration of breast feeding, presence of siblings, vaccination, antibiotic use and pet keeping were also assessed. RESULTS: AD developed in 109 infants (20.4%). In univariate analysis, the presence of either maternal or paternal allergic diseases increased the risk for development of AD in their infants. Multivariate logistic analysis, however, showed that only the presence of maternal allergic diseases correlated with the development of AD (P=0.018). While AD developed in 14.7% in infants of parents with no allergic history, the incidences of AD in infants with a single parent allergy history and in those with 2 parent allergy history were 27.0% and 41.7%, respectively. Their adjusted relative risks (95% confidence intervals) were 1.85 (1.24-2.89) and 2.93 (1.68-4.96), respectively. CONCLUSION: Parental allergic diseases, especially maternal allergic diseases, are possible risk factors for development of AD in Korean infants.

Diclofenac, a Non-steroidal Anti-inflammatory Drug, Inhibits L-type Ca2+ Channels in Neonatal Rat Ventricular Cardiomyocytes

A non-steroidal anti-inflammatory drug (NSAID) has many adverse effects including cardiovascular (CV) risk. Diclofenac among the nonselective NSAIDs has the highest CV risk such as congestive heart failure, which resulted commonly from the impaired cardiac pumping due to a disrupted excitation-contraction (E-C) coupling. We investigated the effects of diclofenac on the L-type calcium channels which are essential to the E-C coupling at the level of single ventricular myocytes isolated from neonatal rat heart, using the whole-cell voltage-clamp technique. Only diclofenac of three NSAIDs, including naproxen and ibuprofen, significantly reduced inward whole cell currents. At concentrations higher than 3 micrometer, diclofenac inhibited reversibly the Na+ current and did irreversibly the L-type Ca2+ channels-mediated inward current (IC50=12.89+/-0.43 micrometer) in a dose-dependent manner. However, nifedipine, a well-known L-type channel blocker, effectively inhibited the L-type Ca2+ currents but not the Na+ current. Our finding may explain that diclofenac causes the CV risk by the inhibition of L-type Ca2+ channel, leading to the impairment of E-C coupling in cardiac myocytes.

A Case of Photodynamic Therapy for Early Esophageal Cancer Recurred after Esophagectomy / 대한소화기학회지

Photodynamic therapy is a promising modality for the palliation of advanced upper gastrointestinal cancer and for the eradication of early neoplastic and pre-neoplastic lesions. It is based on the combination of a photosensitizer that is selectively localized in the target tissue and illumination of the lesion with visible light, resulting in photodamage and subsequent cell death. For early esophageal cancer, esophagectomy has been a standard modality of curative intent. However, accumulated data supports the possibility of PDT replacing surgery as a curative modality. We experienced a case of early esophageal cancer that recurred after esophagectomy. The patient was successfully treated with photodynamic therapy using porfimer sodium as a photosensitizer.

Development of Anuria after Appendectomy in a Patient with a Distal Ureteral Stone in a Single Kidney

The development of anuria after appendectomy is usually related to complications associated with appendicitis or with the surgical sequelae of appendectomy. We report an unusual case of anuria after appendectomy in a 20-year-old woman. The patient was transferred to our hospital due to a sudden cessation of urine output just after appendectomy. We initially suspected that the anuria was caused by a complication of surgery. However, a review of her medical history and an abdominal computed tomography (CT) scan revealed that a distal ureteral stone in a single kidney had caused the anuria. There are few cases in the literature regarding a distal ureteral stone in a single kidney. This case indicates the importance of radiological evaluation in the differential diagnosis of acute appendicitis, especially in patients with unilateral renal agenesis.

A Case of Nonsurgical Treatment in Boerhaave's Syndorme during Diagnostic Endoscopy / 대한소화기내시경학회지

Boerhaave's syndrome is a rare spontaneous rupture of the esophagus that requires an immediate diagnosis and surgical repair. It might result from a severe and uncoordinated contraction of the esophagus and stomach. The rate of mortality and morbidity can increase with increasing time between the onset and treatment. In recent years, there have been some reports of non-surgical treatment in cases with perforation but with minimal symptoms and clinical evidence of the systemic effects such as sepsis. We experienced a case of Boerhaave's syndrome occurring during an endoscopic examination that was treated successfully using non-surgical measures.

A Case of Gastric Adenocarcinoma Presenting as a Submucosal Tumor / 대한소화기내시경학회지

Neoplasms of the stomach can originate from both epithelial and subepithelial cells. These two types of tumors have different morphological characteristics according to their origin including the mucosal surface texture and contour of the mass in endoscopic examination. However, on rare occasions, neoplasms of an epithelial origin manifest the features of a submucosal tumor on a gross examination, and require additional and more invasive approaches, such as a strip biopsy, computed tomography, and endosonography, to define their nature. We encountered a case of a gastric adenocarcinoma in a 44 year-old woman, which was initially considered to be submucosal tumor by the endoscopic examination and was finally diagnosed after resecting the tumor.

Renal Transplantation in a Patient with Idiopathic Thrombocytopenic Purpura

The combination of idiopathic thrombocytopenic purpura (ITP) and chronic renal failure (CRF) is uncommon. This report highlights a case of renal transplantation in a patient with ITP. A 35-year-old man with ITP was admitted with uremic symptoms. A renal transplant and splenectomy was simultaneously performed. A prophylactic pneumococcous vaccination was performed and intravenous immunoglobulin (1 g/kg) was administered before and after the operation. The patient's platelet count increased gradually after the splenectomy. During a two-year follow up period, the graft function was well maintained. Renal transplantation in a patient with ITP is recommended with a well-designed strategy to prevent potential complications.

Effect of Ischemic Neuronal Insults on Amyloid Precursor Protein Processing

BACKGROUND: In spite of the different pathogenesis and exclusive respect in the diagnosis of Alzheimer's disease (AD) and vascular dementia (VaD), recent epidemiological and pathological studies indicates that ischemic stroke have an important role in the pathogenesis of both VaD and AD. However, the association of ischemic stroke and AD on the cellular and molecular level is still unknown. We evaluated the effect of ischemic neuronal insult on the regulation of amyloid precursor protein (APP) processing. METHODS: We used an in vitro model of cerebral ischemia (oxygen-glucose deprivation, OGD) to evaluate the effect of ischemic insult on the amyloidogenic and non-amyloidogenic pathways using human neuroblastoma cell line, SH-SY5Y, and primary cultured cells of Tg2576 APP transgenic mouse. RESULTS: Ischemic insult significantly increased the beta amyloid (A beta) production in the primary cultured cells of Tg2576 APP transgenic mice (p<0.001). A disintegrin and metalloprotease 10 (ADAM 10), a candidate of alpha-secretase, was markedly increased in the early stage of ischemic insult (up to 2 hours of OGD, p<0.001; 4 hours of OGD, p<0.05), which was followed by the decreased level of ADAM 10 expression in a later stage (p<0.001). However, the protein and mRNA expression of beta-site cleavage enzyme (BACE) and BACE activity were not significantly different between the group of ischemic insult and control. By contrast, the activity of gamma-secretase was significantly increased after 4 hours of ischemic insult, as compared to controls. CONCLUSIONS: This study demonstrates that the ischemic neuronal insults increase the production of A beta via activation of the amyloidogenic pathway, which may link the role of ischemic insults to the pathogenesis of AD.

A case of subcutaneous plasmacytomas of vessel puncture site in multiple myeloma after autologous stem cell transplantation / 대한내과학회지

We report a case of a 61-year-old man with Durie-Salmon stage IB, kappa light chain type, multiple myeloma (MM), who relapsed 6 months after autologous hematopoietic stem cell transplantation (HSCT). One month after vinblastin-mitoxantrone-dexamethasone chemotherapy, he presented with multiple subcutaneous plasmacytomas. These lesions were confined to previous vessel puncture sites such as subclavian central catheter insertion site, anchoring site and sampling site. He had no past history of plasmacytoma. After additional treatment of etoposide, cisplatin, solumedrol, cytosine arabinoside, the plasmacytomas decreased or disappeared. But blasts reappeared in his peripheral blood and the size of the plasmacytomas increased. This case represents the rare report of refractory MM presenting as multiple subcutaneous plasmacytomas with specific tropism to the sites of previous trauma.

A Case of Central Diabetes Insipidus in Patient with Non-small Cell Lung Cancer / 결핵및호흡기질환

Central diabetes insipidus (DI) is a disease caused by insufficient release of antidiuretic hormone. Central DI with lung cancer is very rare. Most of them are caused by the pituitary metastasis, and rarely, by the paraneoplastic syndromes. Central DI is diagnosed by the water deprivation test. The treatment consists of surgical resection, radiotherapy and administration of desmopressin. We report an unusual case of central DI with non-small cell lung cancer. The diagnosis was confirmed by water deprivation test. After the administration of desmopressin, the urine osmolarity was increased. The patient's symptoms and urine osmolarity were improved by intranasal desmopressin.

Survey on the Pattern of Food Intake during Early Childhood and Allergic Disease / 소아알레르기및호흡기학회지

PURPOSE: Change of foods intake during infancy and early childhood is being indicated as a causal factor for recent dramatic increase in the number of allergic diseases in children. The food allergens may have an important role for the development of allergic diseases including atopic dermatitis in children. Early prevention and treatment of atopic dermatitis are important to prevent of allergic disease later in life. METHODS: The questionaire survey about the diet patterns of their children and the parents' awareness and knowledge on the relationship between food and allergy was performed for the parents of 316 patients aged under 48 month old at 7 university hospitals (4 allergy clinics and 3 general clinics) or 4 private clinics in September, 2002. RESULTS: Formular fed is more common in all age group and it comprised over 70% in the group under age 6 month old in compare with breast milk fed. The mean age of the start of weaning was 5.2+/-1.8 months in a child with a history of allergy, and 4.6+/-2.0 months who had no allergy history. The most common reason to start weaning was nutritional supplement and the next was to train for adult foods. Fruit juice was the first introduced weaning food in most cases. Among 316 children, 108 children had experience of having grain diet, live diet or natural diet for better nutrition. More than half of the parents had relatively correct knowledge about allergy such as the relationship between food and allergy especially in the group with a allergic disease. Many parents started grain diet, live diet, a soup of bone, and the white of an egg to their children under 12 months of age. CONCLUSION: In general, most of the parents enrolled had relatively correct information about the time and the purpose of weaning. However, their knowledge about the kinds of food and time of first exposure is at issue to be pointed out. Especially as a point of view for early intervention of allergic disease, continued more active education about the food allergens and their relation to allergic diseases are strongly recommended.

Growth, Nutrient Intake and AlIergic Manifestations of the Infants with FamiIy HistoIT of Allergy Fed on HypoaIlergenic Formula vs. GeneraI FormuIa / 소아알레르기및호흡기학회지

This study was designed to investigate growth pattern, nutrient intake, and effecton development of allergic disorders in infants with family history of alIergic diseases fed on hypoallergenic formula(HA) and general formula (GF). This study was done on 101 infants from June, 1996 to May, 1997. Questionnaire were obtained from each mother of infants. Questionaire were inc1uded family history, the growth, nutrient intake, allergic symptoms. Frequent clinical features of these infants was atopic dermatitis89.196, respiratory infection56.4%, rhinitis47.5% and infants with two symptoms was 66.3% HA fed group and GF fed group did not differ significantly on the growth and the energy and protein intake do not meet RDA. HA fed infants compared with the GF fed infants, those fed the HA had higher zinc, fo1ate, copper intake and 1ower protein and phosphorus. HA fed group did seem to have effect on the development of allergic disorders such as atopic demnatitis, respiratory infection, rhinitis. but GF fed group did not reveaI any statistically significant differences. In Conclusion, Hypoallergenic formula fed group seem to have effects on alIergic symptoms in infants at first year with family history of allergy. But it might be suggested that follow-up study is needed to inspect whether the significant effects on the al1ergic symptoms.