T-Type Calcium Channels Are Required to Maintain Viability of Neural Progenitor Cells

T-type calcium channels are low voltage-activated calcium channels that evoke small and transient calcium currents. Recently, T-type calcium channels have been implicated in neurodevelopmental disorders such as autism spectrum disorder and neural tube defects. However, their function during embryonic development is largely unknown. Here, we investigated the function and expression of T-type calcium channels in embryonic neural progenitor cells (NPCs). First, we compared the expression of T-type calcium channel subtypes (CaV3.1, 3.2, and 3.3) in NPCs and differentiated neural cells (neurons and astrocytes). We detected all subtypes in neurons but not in astrocytes. In NPCs, CaV3.1 was the dominant subtype, whereas CaV3.2 was weakly expressed, and CaV3.3 was not detected. Next, we determined CaV3.1 expression levels in the cortex during early brain development. Expression levels of CaV3.1 in the embryonic period were transiently decreased during the perinatal period and increased at postnatal day 11. We then pharmacologically blocked T-type calcium channels to determine the effects in neuronal cells. The blockade of T-type calcium channels reduced cell viability, and induced apoptotic cell death in NPCs but not in differentiated astrocytes. Furthermore, blocking T-type calcium channels rapidly reduced AKT-phosphorylation (Ser473) and GSK3β-phosphorylation (Ser9). Our results suggest that T-type calcium channels play essential roles in maintaining NPC viability, and T-type calcium channel blockers are toxic to embryonic neural cells, and may potentially be responsible for neurodevelopmental disorders.

Valproic Acid Induces Telomerase Reverse Transcriptase Expression during Cortical Development

The valproic acid (VPA)-induced animal model is one of the most widely utilized environmental risk factor models of autism. Autism spectrum disorder (ASD) remains an insurmountable challenge among neurodevelopmental disorders due to its heterogeneity, unresolved pathological pathways and lack of treatment. We previously reported that VPA-exposed rats and cultured rat primary neurons have increased Pax6 expression during post-midterm embryonic development which led to the sequential upregulation of glutamatergic neuronal markers. In this study, we provide experimental evidence that telomerase reverse transcriptase (TERT), a protein component of ribonucleoproteins complex of telomerase, is involved in the abnormal components caused by VPA in addition to Pax6 and its downstream signals. In embryonic rat brains and cultured rat primary neural progenitor cells (NPCs), VPA induced the increased expression of TERT as revealed by Western blot, RT-PCR, and immunostainings. The HDAC inhibitor property of VPA is responsible for the TERT upregulation. Chromatin immunoprecipitation revealed that VPA increased the histone acetylation but blocked the HDAC1 binding to both Pax6 and Tert genes. Interestingly, the VPA-induced TERT overexpression resulted to sequential upregulations of glutamatergic markers such as Ngn2 and NeuroD1, and inter-synaptic markers such as PSD-95, α-CaMKII, vGluT1 and synaptophysin. Transfection of Tert siRNA reversed the effects of VPA in cultured NPCs confirming the direct involvement of TERT in the expression of those markers. This study suggests the involvement of TERT in the VPA-induced autistic phenotypes and has important implications for the role of TERT as a modulator of balanced neuronal development and transmission in the brain.

Erratum: Valproic Acid Induces Telomerase Reverse Transcriptase Expression during Cortical Development

In the ‘Acknowledgements’ section on page 263 of the original article, the grant number was incorrectly stated.

Sex Differences in Autism-Like Behavioral Phenotypes and Postsynaptic Receptors Expression in the Prefrontal Cortex of TERT Transgenic Mice

Autism spectrum disorder (ASD) remains unexplained and untreated despite the high attention of research in recent years. Aside from its various characteristics is the baffling male preponderance over the female population. Using a validated animal model of ASD which is the telomerase reverse transcriptase overexpressing mice (TERT-tg), we conducted ASD-related behavioral assessments and protein expression experiments to mark the difference between male and females of this animal model. After statistically analyzing the results, we found significant effects of TERT overexpression in sociability, social novelty preference, anxiety, nest building, and electroseizure threshold in the males but not their female littermates. Along these differences are the male-specific increased expressions of postsynaptic proteins which are the NMDA and AMPA receptors in the prefrontal cortex. The vGluT1 presynaptic proteins, but not GAD, were upregulated in both sexes of TERT-tg mice, although it is more significantly pronounced in the male group. Here, we confirmed that the behavioral effect of TERT overexpression in mice was male-specific, suggesting that the aberration of this gene and its downstream pathways preferentially affect the functional development of the male brain, consistent with the male preponderance in ASD.

Sex Differences in Autism-Like Behavioral Phenotypes and Postsynaptic Receptors Expression in the Prefrontal Cortex of TERT Transgenic Mice

Autism spectrum disorder (ASD) remains unexplained and untreated despite the high attention of research in recent years. Aside from its various characteristics is the baffling male preponderance over the female population. Using a validated animal model of ASD which is the telomerase reverse transcriptase overexpressing mice (TERT-tg), we conducted ASD-related behavioral assessments and protein expression experiments to mark the difference between male and females of this animal model. After statistically analyzing the results, we found significant effects of TERT overexpression in sociability, social novelty preference, anxiety, nest building, and electroseizure threshold in the males but not their female littermates. Along these differences are the male-specific increased expressions of postsynaptic proteins which are the NMDA and AMPA receptors in the prefrontal cortex. The vGluT1 presynaptic proteins, but not GAD, were upregulated in both sexes of TERT-tg mice, although it is more significantly pronounced in the male group. Here, we confirmed that the behavioral effect of TERT overexpression in mice was male-specific, suggesting that the aberration of this gene and its downstream pathways preferentially affect the functional development of the male brain, consistent with the male preponderance in ASD.

Clinical and Neurobiological Relevance of Current Animal Models of Autism Spectrum Disorders

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by social and communication impairments, as well as repetitive and restrictive behaviors. The phenotypic heterogeneity of ASD has made it overwhelmingly difficult to determine the exact etiology and pathophysiology underlying the core symptoms, which are often accompanied by comorbidities such as hyperactivity, seizures, and sensorimotor abnormalities. To our benefit, the advent of animal models has allowed us to assess and test diverse risk factors of ASD, both genetic and environmental, and measure their contribution to the manifestation of autistic symptoms. At a broader scale, rodent models have helped consolidate molecular pathways and unify the neurophysiological mechanisms underlying each one of the various etiologies. This approach will potentially enable the stratification of ASD into clinical, molecular, and neurophenotypic subgroups, further proving their translational utility. It is henceforth paramount to establish a common ground of mechanistic theories from complementing results in preclinical research. In this review, we cluster the ASD animal models into lesion and genetic models and further classify them based on the corresponding environmental, epigenetic and genetic factors. Finally, we summarize the symptoms and neuropathological highlights for each model and make critical comparisons that elucidate their clinical and neurobiological relevance.

Exploring the Validity of Valproic Acid Animal Model of Autism

The valproic acid (VPA) animal model of autism spectrum disorder (ASD) is one of the most widely used animal model in the field. Like any other disease models, it can't model the totality of the features seen in autism. Then, is it valid to model autism? This model demonstrates many of the structural and behavioral features that can be observed in individuals with autism. These similarities enable the model to define relevant pathways of developmental dysregulation resulting from environmental manipulation. The uncovering of these complex pathways resulted to the growing pool of potential therapeutic candidates addressing the core symptoms of ASD. Here, we summarize the validity points of VPA that may or may not qualify it as a valid animal model of ASD.

Effects of Atomoxetine on Hyper-Locomotive Activity of the Prenatally Valproate-Exposed Rat Offspring

A substantial proportion of patients with autism spectrum disorder (ASD) display hyperactivity as a comorbid symptom. Exposure to valproic acid (VPA) during pregnancy produces ASD-like core behavioral phenotypes as well as hyperactivity in offspring both in human and experimental animals, which makes it a plausible model to study ASD-related neurobiological processes. In this study, we examined the effects of two of currently available attention defecit hyperactivity disorder (ADHD) medications, methylphenidate (MPH) and atomoxetine (ATX) targeting dopamine and norepinephrine transporters (DAT and NET), respectively, on hyperactive behavior of prenatally VPA-exposed rat offspring. In the prefrontal cortex of VPA exposed rat offspring, both mRNA and protein expression of DAT was increased as compared with control. VPA function as a histone deacetylase inhibitor (HDACi) and chromatin immunoprecipitation experiments demonstrated that the acetylation of histone bound to DAT gene promoter was increased in VPA-exposed rat offspring suggesting epigenetic mechanism of DAT regulation. Similarly, the expression of NET was increased, possibly via increased histone acetylation in prefrontal cortex of VPA-exposed rat offspring. When we treated the VPA-exposed rat offspring with ATX, a NET selective inhibitor, hyperactivity was reversed to control level. In contrast, MPH that inhibits both DAT and NET, did not produce inhibitory effects against hyperactivity. The results suggest that NET abnormalities may underlie the hyperactive phenotype in VPA animal model of ASD. Profiling the pharmacological responsiveness as well as investigating underlying mechanism in multiple models of ASD and ADHD may provide more insights into the neurobiological correlates regulating the behavioral abnormalities.

Acute Polymyositis/systemic Lupus Erythematosus Overlap Syndrome with Severe Subcutaneous Edema and Interstitial Lung Disease

Inflammatory myopathy is characterized by symmetrical proximal muscle weakness, elevated muscle enzyme levels and favorable response to glucocorticoids therapy. Although periorbital edema is a common manifestation of inflammatory myopathy, generalized subcutaneous edema is very rare. We report here a case of a 47-year-old female patient with acute polymyositis/systemic lupus erythematosus overlap syndrome with generalized subcutaneous edema and interstitial lung disease. We aggressively treated the disease with high-dose glucocorticoids, intravenous immunoglobulin, and immunosuppressive agents.

Etanercept for steroid-refractory acute graft versus host disease following allogeneic hematopoietic stem cell transplantation

BACKGROUND/AIMS: The treatment for steroid-refractory acute graft versus host disease (GVHD) after allogeneic stem cell transplantation (allo-SCT) needs to be standardized. We report our clinical experience with etanercept for steroid-refractory acute GVHD. METHODS: Eighteen patients who underwent allo-SCT and presented with steroid-refractory acute GVHD at Ajou University Hospital were studied retrospectively. They were given 25 mg of etanercept subcutaneously twice weekly for 4 weeks. The clinical responses were evaluated with regard to the severity of acute GVHD. RESULTS: The median patient age was 43.5 years. Using nonparametric tests, etanercept had a down-grading effect on acute GVHD (p = 0.005), although no patient experienced complete remission. Partial responses were seen in 80%, 17%, and 57% of grade II to IV patients, respectively. Skin and gut GVHD were well controlled with etanercept, whereas hepatic GVHD was not. Four patients died of fatal infections. No factors affecting the clinical outcome of etanercept were identified. CONCLUSIONS: Etanercept has a modest effect on steroid-refractory acute GVHD after allo-SCT, with tolerable side effects.

A Case of Sclerosing Angiomatoid Nodular Transformation of the Spleen: Spoke Wheel Pattern on Computed Tomography / 대한내과학회지

Sclerosing angiomatoid nodular transformation (SANT) is a rare, benign vascular neoplasm. Most patients have no clinical symptoms, and the tumors are usually discovered incidentally on abdominal computed tomography or ultrasonography. Some studies have reported the clinical features and imaging findings of SANT, but the diagnosis is based on histopathologic examination of a tissue specimen obtained at splenectomy. We report herein an incidentally discovered case of SANT and review the related literature.

Kartagener's syndrome with immunoglobulin G subclass deficiency

Kartagener syndrome is characterized by the triad of situs inversus, bronchiectasis, and chronic paranasal sinusitis. Recurrent sinopulmonary infection, the major determinant for diagnosing immunodeficiency, is the most common clinical manifestation of the disease. A 17-year-old female patient presented with dyspnea, cough, sputum, nasal congestion, and rhinorrhea for more than 5 years. Nasal symptoms and dyspnea had not been controlled by intermittent treatment with mucolytics and antibiotics from primary clinics since 3 months before visiting our clinic. Chest X-ray and computed tomography showed situs inversus, dextrocardia and bronchiectasis. Paranasal sinus series revealed mucosal thickening and haziness on both maxillary sinus. Serum immunoglobulin (Ig) G4 was decreased, but total IgG was within normal range. Under the diagnosis of Kartagener syndrome with IgG4 deficiency, monthly intravenous IgG (IVIG) treatment was performed for 6 months. Her symptoms were well controlled and the frequency of antibiotics use was markedly decreased. We report a patient having the Kartagener syndrome with IgG4 deficiency that was successfully controlled with a 6-month-treatment of IVIG.

Gastrointestinal Tract Abnormalities Induced by Prenatal Valproic Acid Exposure in Rat Offspring

In-utero exposure to valproic acid (VPA) has been known as a potent inducer of autism spectrum disorder (ASD), not only in humans, but also in animals. In addition to the defects in communication and social interaction as well as repetitive behaviors, ASD patients usually suffer from gastrointestinal (GI) problems. However, the exact mechanism underlying these disorders is not known. In this study, we examined the gross GI tract structure and GI motility in a VPA animal model of ASD. On embryonic day 12 (E12), 4 pregnant Sprague-Dawley (SD) rats were subcutaneously injected with VPA (400 mg/kg) in the treatment group, and with phosphate buffered saline (PBS) in the control group; the resulting male offspring were analyzed at 4 weeks of age. VPA exposure decreased the thickness of tunica mucosa and tunica muscularis in the stomach and ileum. Other regions such as duodenum, jejunum, and colon did not show a significant difference. In high-resolution microscopic observation, atrophy of the parietal and chief cells in the stomach and absorptive cells in the ileum was observed. In addition, decreased staining of the epithelial cells was observed in the hematoxylin and eosin (H&E)-stained ileum section. Furthermore, decreased motility in GI tract was also observed in rat offspring prenatally exposed to VPA. However, the mechanism underlying GI tract defects in VPA animal model as well as the association between abnormal GI structure and function with ASD is yet to be clearly understood. Nevertheless, the results from the present study suggest that this VPA ASD model undergoes abnormal changes in the GI structure and function, which in turn could provide beneficial clues pertaining to the pathophysiological relevance of GI complications and ASD phenotypes.

Transcriptional Upregulation of Plasminogen Activator Inhibitor-1 in Rat Primary Astrocytes by a Proteasomal Inhibitor MG132

Plasminogen activator inhibitor-1 (PAI-1) is a member of serine protease inhibitor family, which regulates the activity of tissue plasminogen activator (tPA). In CNS, tPA/PAI-1 activity is involved in the regulation of a variety of cellular processes such as neuronal development, synaptic plasticity and cell survival. To gain a more insights into the regulatory mechanism modulating tPA/PAI-1 activity in brain, we investigated the effects of proteasome inhibitors on tPA/PAI-1 expression and activity in rat primary astrocytes, the major cell type expressing both tPA and PAI-1. We found that submicromolar concentration of MG132, a cell permeable peptide-aldehyde inhibitor of ubiquitin proteasome pathway selectively upregulates PAI-1 expression. Upregulation of PAI-1 mRNA as well as increased PAI-1 promoter reporter activity suggested that MG132 transcriptionally increased PAI-1 expression. The induction of PAI-1 downregulated tPA activity in rat primary astrocytes. Another proteasome inhibitor lactacystin similarly increased the expression of PAI-1 in rat primary astrocytes. MG132 activated MAPK pathways as well as PI3K/Akt pathways. Inhibitors of these signaling pathways reduced MG132-mediated upregulation of PAI-1 in varying degrees and most prominent effects were observed with SB203580, a p38 MAPK pathway inhibitor. The regulation of tPA/PAI-1 activity by proteasome inhibitor in rat primary astrocytes may underlie the observed CNS effects of MG132 such as neuroprotection.

Autologous Stem Cell Transplantation in the Treatment of Refractory Rheumatoid Arthritis

The concept of using high-dose immunosuppressive treatment (HDIT) with autologous stem cell transplantation (ASCT) to treat patients with refractory rheumatoid arthritis has been provided by animal studies and anecdotal case reports. Over the past five years, an increasing number of patients with refractory rheumatoid arthritis have received HDIT with ASCT as an adjunct to intense immunosuppression. Here, we present a case of refractory rheumatoid arthritis in a 54-yr-old woman using HDIT with ASCT. Peripheral blood stem cells were mobilized with cyclophosphamide (4 g/m(2)) followed by G-CSF (5microgram/kg/day). Leukapheresis continued daily until the number of harvested progenitor cells reached 2 x 10(6) CD34+ cells/kg after CliniMax(R) CD34+ positive selection. For HDIT, high-dose cyclophosphamide (total dose 200 mg/kg) and antithymocyte globulin (total dose 90 mg/kg) were administered and CD34+ cells were infused 24 hr after HDIT. The patient tolerated the treatment well but experienced an episode of neutropenic fever. She achieved an early dramatic improvement of joint symptoms during therapy. Fifty percent of improvement of rheumatoid arthritis by the American College of Rheumatology (ACR 50) preliminary definition was fulfilled during the 6 months following ASCT. Although further long-term follow-up is required, the patient's activity of arthritis has been stable since receiving HDIT with ASCT.

A Case of Polymyositis with Dilated Cardiomyopathy Associated with Interferon alpha Treatment for Hepatitis B

Polymyositis is a rare complication of interferon alpha treatment as a result of immunemodulating role of the drug itself. In this case, interferon alpha induced polymyositis and cardiomyopathy is diagnosed in a 33-yr-old male patient with history of chronic hepatitis B. To treat hepatitis B, interferon alpha was administered until the proximal muscle weakness developed. Thereafter, sixteen cycles of immunoglobulin treatment (400 mg/kg) along with corticosteroids were instituted and led to an improvement in subjective symptoms with decreases in level of CPK and LDH. However, dilated cardiomyopathy has not improved in spite of the cessation of interferon treatment. Unlike the persistently elevated serum HBV DNA level, the serum ALT and AST levels have gradually decreased. Our case shows that clinical symptoms of polymyositis improved with steroid and immunoglobulin treatment without deterioration of the hepatitis B. To our knowledge, this is the first case of polymyositis associated with dilated cardiomyopathy after the administration of interferon in a patient with hepatitis B.

A Case of Protein-Losing Enteropathy Associated with Systemic Lupus Erythematosus / 대한류마티스학회지

Systemic lupus erythematosus (SLE) is a multisystemic disease that can affect most organ system, although gastrointestinal (GI) manifestations are relatively uncommon. Protein losing enteropathy (PLE) is associated with several clinical disorders, but it is an unusual manifestation of SLE. Of over 20 reported cases of PLE associated with SLE, the pathogenesis of lupus associated PLE remains unclear. We describe a patient with edema, diarrhea, abdomianl pain, and hypoalbuminemia who had been diagnosed SLE. PLE was diagnosed by the method of alpha1-antitrypsin clearance in stool.

A Case of Microscopic Polyangiitis with Peripheral Neuropathy / 대한류마티스학회지

Microscopic polyangiitis (MPA) is a systemic necrotizing vasculitis of small-sized vessels (capillary, venule, or arterioles) whose clinical manifestations are very similar to those of PAN (polyarteritis nodosa), but it is characterized by the presence of rapidly progressive glomerulonephritis (RPGN), which is nearly constant, and pulmonary involvement usually absent in PAN. Peripheral neuropathy occurs in only 14~36% of the patients with MPA, distinctly less frequent than in those with classic PAN. While PAN may be considered a self-limiting disease which tend not to recur once remission is acquired, relapse occurs frequently in MPA. Prognosis has been transformed by corticosteroids and immunosuppressive drugs, especially cyclophosphamide. We reported a 72-year-old woman with subacute sensorimotor polyneuropathy involving peroneal and sural nerve accompanied by focal segmental glomerulonephritis which was proven by renal biopsy.

Clinical and serologic characteristics of mixed connective tissue disease in korea / 대한내과학회지

The concept that mixed connective tissue disease (MCTD) is a clinically distinct disease entity has been the subject of debate. Some authors regard it as a transitional phase in the development of systemic lupus erythematosus (SLE), systemic sclerosis (SSc), or polymyositis/ dermatomyositis (PM-DM). This study set out to analyze the clinical and serologic characteristics of MCTD in Korean patients and to determine whether the diagnosis of MCTD held up on follow-up. METHODS: Forty-five patients diagnosed as MCTD using the diagnostic criteria of Alarcon-Segovia between October 1989 and February 1998 at Hanyang University Hospital were retrospectively reviewed. RESULTS: All but two patients were female. The average age at diagnosis was 39.3 years and the average diaseae duration was 7.5 years. The most frequent clinical symptoms were Raynauds phenomenon (100%), followed by synovitis (73%), swollen hands (68%), and myositis (48%). Lung involvement was evident in 53% and renal involvement in 15%. After a follow-up period averaging 3.3 years, 3 patients showed evidence of progressing towards SLE (increasing anti-dsDNA, decreased complement level, or disappearance of anti-nRNP and appearance of anti-Sm). One of our patients converted to SSc, but none of our patients converted to PM/DM. CONCLUSION: Only 4 (9%) of our patients showed evidence of developing into a classic connective tissue disease. Although we believe that regular follow-up on our patients would be needed, our findings lead us to conclude that MCTD is a distinct entity in Korean patients.

Clinical and serologic characteristics of mixed connective tissue disease in korea / 대한내과학회지

The concept that mixed connective tissue disease (MCTD) is a clinically distinct disease entity has been the subject of debate. Some authors regard it as a transitional phase in the development of systemic lupus erythematosus (SLE), systemic sclerosis (SSc), or polymyositis/ dermatomyositis (PM-DM). This study set out to analyze the clinical and serologic characteristics of MCTD in Korean patients and to determine whether the diagnosis of MCTD held up on follow-up. METHODS: Forty-five patients diagnosed as MCTD using the diagnostic criteria of Alarcon-Segovia between October 1989 and February 1998 at Hanyang University Hospital were retrospectively reviewed. RESULTS: All but two patients were female. The average age at diagnosis was 39.3 years and the average diaseae duration was 7.5 years. The most frequent clinical symptoms were Raynauds phenomenon (100%), followed by synovitis (73%), swollen hands (68%), and myositis (48%). Lung involvement was evident in 53% and renal involvement in 15%. After a follow-up period averaging 3.3 years, 3 patients showed evidence of progressing towards SLE (increasing anti-dsDNA, decreased complement level, or disappearance of anti-nRNP and appearance of anti-Sm). One of our patients converted to SSc, but none of our patients converted to PM/DM. CONCLUSION: Only 4 (9%) of our patients showed evidence of developing into a classic connective tissue disease. Although we believe that regular follow-up on our patients would be needed, our findings lead us to conclude that MCTD is a distinct entity in Korean patients.