Effect of Sodium Salicylate on Calcium Currents and Exocytosis in Cochlear Inner Hair Cells: Implications for Tinnitus Generation / 神经科学通报·英文版

Sodium salicylate is an anti-inflammatory medication with a side-effect of tinnitus. Here, we used mouse cochlear cultures to explore the effects of salicylate treatment on cochlear inner hair cells (IHCs). We found that IHCs showed significant damage after exposure to a high concentration of salicylate. Whole-cell patch clamp recordings showed that 1-5 mmol/L salicylate did not affect the exocytosis of IHCs, indicating that IHCs are not involved in tinnitus generation by enhancing their neuronal input. Instead, salicylate induced a larger peak amplitude, a more negative half-activation voltage, and a steeper slope factor of Ca2+ current. Using noise analysis of Ca2+ tail currents and qRT-PCR, we further found that salicylate increased the number of Ca2+ channels along with CaV1.3 expression. All these changes could act synergistically to enhance the Ca2+ influx into IHCs. Inhibition of intracellular Ca2+ overload significantly attenuated IHC death after 10 mmol/L salicylate treatment. These results implicate a cellular mechanism for tinnitus generation in the peripheral auditory system.

Exo70 intracellular redistribution after repeated mild traumatic brain injury

BACKGROUND: Exo70 is a subunit of the greater exocyst complex, a collection of proteins that oversees cellular membrane addition and polarized exocytosis by acting as a tethering intermediate between the plasma membrane and newly synthesized secretory vesicles. Although Exo70 function has been implicated in several developmental events including cytokinesis and the establishment of cell polarity, its role in neuropathologies is poorly understood. On the other hand, traumatic brain injury is the result of mechanical external force including contusion, fast acceleration, and expansive waves that produce temporal or permanent cognitive damage and triggers physical and psychosocial alterations including headache, memory problems, attention deficits, difficulty thinking, mood swings, and frustration. Traumatic brain injury is a critical health problem on a global scale, constituting a major cause of deaths and disability among young adults. Trauma-related cellular damage includes redistribution of N-methyl-D-aspartate receptors outside of the synaptic compartment triggering detrimental effects to neurons. The exocyst has been related to glutamate receptor constitutive trafficking/delivery towards synapse as well. This work examines whether the exocyst complex subunit Exo70 participates in traumatic brain injury and if it is redistributed among subcellular compartments RESULTS: Our analysis shows that Exo70 expression is not altered upon injury induction. By using subcellular fractionation, we determined that Exo70 is redistributed from microsomes fraction into the synaptic compartment after brain trauma. In the synaptic compartment, we also show that the exocyst complex assembly and its interaction with GluN2B are increased. Finally, we show that the Exo70 pool that is redistributed comes from the plasma membrane. CONCLUSIONS: The present findings position Exo70 in the group of proteins that could modulate GluN2B synaptic availability in acute neuropathology like a traumatic brain injury. By acting as a nucleator factor, Exo70 is capable of redirecting the ensembled complex into the synapse. We suggest that this redistribution is part of a compensatory mechanism by which Exo70 is able to maintain GluN2B partially on synapses. Hence, reducing the detrimental effects associated with TBI pathophysiology.

The role of the exocyst in renal ciliogenesis, cystogenesis, tubulogenesis, and development

The exocyst is a highly conserved eight-subunit protein complex (EXOC1–8) involved in the targeting and docking of exocytic vesicles translocating from the trans-Golgi network to various sites in renal cells. EXOC5 is a central exocyst component because it connects EXOC6, bound to the vesicles exiting the trans-Golgi network via the small GTPase RAB8, to the rest of the exocyst complex at the plasma membrane. In the kidney, the exocyst complex is involved in primary ciliognesis, cystogenesis, and tubulogenesis. The exocyst, and its regulators, have also been found in urinary extracellular vesicles, and may be centrally involved in urocrine signaling and repair following acute kidney injury. The exocyst is centrally involved in the development of other organs, including the eye, ear, and heart. The exocyst is regulated by many different small GTPases of the RHO, RAL, RAB, and ARF families. The small GTPases, and their guanine nucleotide exchange factors and GTPase-activating proteins, likely give the exocyst specificity of function. The recent development of a floxed Exoc5 mouse line will aid researchers in studying the role of the exocyst in multiple cells and organ types by allowing for tissue-specific knockout, in conjunction with Cre-driver mouse lines.

Clinicopathological Analysis of Patients with Acute Generalized Exanthematous Pustulosis / 대한피부과학회지

BACKGROUND: Acute generalized exanthematous pustulosis (AGEP) is typically a medication-induced acute febrile eruption. Few large-scale studies have reported clinical data regarding AGEP in Korea. OBJECTIVE: This study analyzed the clinical and histopathological features of AGEP in Koreans to identify recent trends in this context. METHODS: This study retrospectively reviewed 31 patients with AGEP. Age, sex, clinical features, etiologies, laboratory findings, histopathological features, and treatment outcomes were obtained from patients' medical records and photographs. RESULTS: The mean age of onset was 43.6 years, and the male:female ratio was 2.1:1. All patients showed non-follicular tiny pustules and erythema. Fever was reported in 13 patients and neutrophilia in 17 patients. Medications were considered the most common etiological contributors. Twenty patients showed drug-induced AGEP, and 11 of 20 patients showed antibiotic-induced AGEP. Serum C-reactive protein and lactate dehydrogenase levels increased in 93.8% and 77.8% of the patients, respectively. Histopathologically, all patients showed subcorneal or intraepidermal pustules, followed by exocytosis and neutrophilic dermal infiltrate. Twenty-five patients improved within a mean period of 7.5 days after the onset of the skin rash. The percentage of women in the drug-induced AGEP group was significantly higher than that in the non-drug-induced AGEP group. CONCLUSION: This report describes a large-scale study that analyzed the clinical and histopathological features of AGEP in Koreans and seems to accurately reflect the recent trends in this context. Clinically, it is important to note that the percentage of women in the drug-induced AGEP group was higher than that in groups showing other etiologies of AGEP.

Histopathologic Study of Morbilliform Drug Eruption: Differences between Chemotherapeutic Agents and Antibiotics / 대한피부과학회지

BACKGROUND: Cutaneous drug eruption is very common, and its clinical manifestations are variable. Diagnosis of drug eruption is usually based on clinical findings and medication history. To date, few studies have compared the variable histopathologic findings of drug eruption according to medication. OBJECTIVE: We focused on morbilliform eruption among diverse manifestations of drug eruption and investigated the differences in histopathologic findings between antibiotics- and chemotherapeutic-agent-induced morbilliform drug eruption. METHODS: We reviewed medical charts established from March 1998 to August 2016 at our hospital. Inclusion criteria were histopathologically confirmed drug eruptions, clinical demonstrations of typical morbilliform eruptions obtained from medical photographs, and causative drugs identified as chemotherapeutic agents or antibiotics. Immunohistochemical staining was performed and included CD3, CD4, CD8, CD20, CD56, CD68, langerin, CD138, and c-kit. RESULTS: A total of 40 cases (20 cases, chemotherapeutic group; 20 cases, antibiotics group) were included in this study. The most frequent histologic feature of the epidermis was exocytosis (95%) in the chemotherapeutic group and necrotic keratinocytes (100%) in the antibiotics group. Inflammatory infiltration depths were significantly deeper in the antibiotics group than in the chemotherapeutic group. There was no significant difference between the two groups in terms of immunohistochemical staining. CONCLUSION: This study suggested that in patients with morbilliform drug eruption, chemotherapeutic agents cause more superficial inflammation compared to antibiotics. These findings may facilitate the differentiation of the culprit agents of morbilliform drug eruption in cancer patients. Further large, well-designed studies are needed to confirm these findings.

Erlotinib-related Severe Hair Loss with Severe Exanthematous Drug Eruption: A Case Report / 대한피부과학회지

Erlotinib inhibits the epidermal growth factor receptor and is used in patients with various cancers. However, it can affect the epidermis and hair because the receptor is expressed in normal skin cells. A 54-year-old woman with metastatic non-small-cell lung cancer presented with erythematous patches over her entire body and severe hair shedding 2 weeks after starting erlotinib. Histopathological examinations showed lymphocytic exocytosis; perivascular infiltration of lymphohistiocytes and eosinophils in the right arm; and marked infiltration of eosinophils, neutrophils, and lymphohistiocytes in the scalp. Erlotinib discontinuation improved hair loss and skin lesions. Hair loss has been reported in 5% of patients taking erlotinib. Our case was unusual in that there was complete baldness, and to our knowledge, no report of complete hair loss and exanthematous drug eruption after erlotinib treatment has been previously reported. Here, we report a case of severe hair loss with concurrent exanthematous drug eruption that may have been linked to erlotinib hypersensitivity.

The potential theragnostic (diagnostic+therapeutic) application of exosomes in diverse biomedical fields

Exosomes are membranous vesicles of 30-150 nm in diameter that are derived from the exocytosis of the intraluminal vesicles of many cell types including immune cells, stem cells, cardiovascular cells and tumor cells. Exosomes participate in intercellular communication by delivering their contents to recipient cells, with or without direct contact between cells, and thereby influence physiological and pathological processes. They are present in various body fluids and contain proteins, nucleic acids, lipids, and microRNAs that can be transported to surrounding cells. Theragnosis is a concept in next-generation medicine that simultaneously combines accurate diagnostics with therapeutic effects. Molecular components in exosomes have been found to be related to certain diseases and treatment responses, indicating that they may have applications in diagnosis via molecular imaging and biomarker detection. In addition, recent studies have reported that exosomes have immunotherapeutic applications or can act as a drug delivery system for targeted therapies with drugs and biomolecules. In this review, we describe the formation, structure, and physiological roles of exosomes. We also discuss their roles in the pathogenesis and progression of diseases including neurodegenerative diseases, cardiovascular diseases, and cancer. The potential applications of exosomes for theragnostic purposes in various diseases are also discussed. This review summarizes the current knowledge about the physiological and pathological roles of exosomes as well as their diagnostic and therapeutic uses, including emerging exosome-based therapies that could not be applied until now.

Mecanismo de exocitosis de gránulos citotóxicos: claves dadas a partir de la linfohistiocitosis hemofagocítica primaria / Exocytosis mechanism of cytotoxic granules: keys given from primary hemophagocytic lymphohistiocytosis / Mecanismo de exocitose de grânulos citotóxicos: Chaves dadas a partir de linfohistiocitose hemofagocítica primária

La linfohistiocitosis hemofagocítica (HLH) es un síndrome clínico de hiperinflamación que se caracteriza por ser una respuesta inmune altamente estimulada pero inefectiva. En la HLH primaria se encuentran alterados el proceso de exocitosis de gránulos citotóxicos o los efectores que se encuentran en éstos, también existe afección de la activación de las células citotóxicas. Durante la exocitosis existe disfunción en la fase de transporte y maduración vesicular, en la regulación del proceso de docking y priming o en los complejos v-SNARE y t-SNARE. La conexión entre la célula citotóxica y célula diana se compromete si se afecta la proteína efectora perforina. SAP y XIAP se relacionan con la activación de las células inmunitarias. Aunque actualmente se conoce más de las moléculas que participan en la citotoxicidad, existe redundancia en las funciones de estas proteínas y aún quedan funciones que no han sido dilucidadas en dichos procesos.

Hemophagocytic lymphohistiocytosis (HLH) is a clinical syndrome of hyperinflammation, in which the immune response is highly stimulated but it is ineffective. In primary HLH, the exocytosis process of cytotoxic granules or the effector proteins contained there are altered and the activation process of cytotoxic cells could be affected as well. During exocytosis there is dysfunction in vesicle maturation or translocation, in regulator proteins of the docking and priming process, or in v-SNARE and t-SNARE complexes. Connection between the cytotoxic cell and the target cell may be compromised if perforin effector protein is affected. SAP and XIAP have a role in the activation of immune cells. Though there is currently much known about the molecules participating in cytotoxicity, there is redundancy in protein functions involved in primary HLH, and there are some functions of these proteins that are still unknown.

A linfohistiocitose hemofagocítica (HLH) é uma síndrome clínica de hiperinflamação caracterizada por uma resposta imune que, apesar de ser altamente estimulada, é ineficaz. Na HLH primária, o processo de exocitose de grânulos citotóxicos, ou os efetores contidos neles, encontram-se alterados, também existe afecção na ativação das células citotóxicas. Existe disfunção na fase de transporte e amadurecimento vesicular, na regulação do processo de docking e priming, ou nos complexos v-SNARE e t-SNARE durante a exocitose. Caso a proteína efetora perforina estiver afetada, a conexão entre a célula citotóxica e a célula alvo está comprometida. SAP e XIAP estão relacionadas com a ativação das células imunitárias. Embora atualmente haja mais conhecimento a respeito das moléculas envolvidas na citotoxicidade, existe redundância nas funções destas proteínas. Contudo, ainda existem funções naqueles processos que não têm sido elucidadas até hoje.

Mitochondrial calcium uniporter inhibition attenuates mouse bone marrow-derived mast cell degranulation induced by beta-1,3-glucan

Mast cells are primary mediators of allergic inflammation. Beta-1,3-glucan (BG) protects against infection and shock by activating immune cells. Activation of the BG receptor induces an increase in intracellular Ca2+, which may induce exocytosis. However, little is known about the precise mechanisms underlying BG activation of immune cells and the possible role of mitochondria in this process. The present study examined whether BG induced mast cell degranulation, and evaluated the role of calcium transients during mast cell activation. Our investigation focused on the role of the mitochondrial calcium uniporter (MCU) in BG-induced degranulation. Black mouse (C57) bone marrow-derived mast cells were stimulated with 0.5 microg/ml BG, 100 microg/ml peptidoglycan (PGN), or 10 microM A23187 (calcium ionophore), and dynamic changes in cytosolic and mitochondrial calcium and membrane potential were monitored. BG-induced mast cell degranulation occurred in a time-dependent manner, and was significantly reduced under calcium-free conditions. Ruthenium red, a mitochondrial Ca2+ uniporter blocker, significantly reduced mast cell degranulation induced by BG, PGN, and A23187. These results suggest that the mitochondrial Ca2+ uniporter has an important regulatory role in BG-induced mast cell degranulation.

Gintonin facilitates catecholamine secretion from the perfused adrenal medulla

The present study was designed to investigate the characteristics of gintonin, one of components isolated from Korean Ginseng on secretion of catecholamines (CA) from the isolated perfused model of rat adrenal gland and to clarify its mechanism of action. Gintonin (1 to 30 µg/ml), perfused into an adrenal vein, markedly increased the CA secretion from the perfused rat adrenal medulla in a dose-dependent fashion. The gintonin-evoked CA secretion was greatly inhibited in the presence of chlorisondamine (1 µM, an autonomic ganglionic bloker), pirenzepine (2 µM, a muscarinic M₁ receptor antagonist), Ki14625 (10 µM, an LPA₁/₃ receptor antagonist), amiloride (1 mM, an inhibitor of Na⁺/Ca²⁺ exchanger), a nicardipine (1 µM, a voltage-dependent Ca²⁺ channel blocker), TMB-8 (1 µM, an intracellular Ca²⁺ antagonist), and perfusion of Ca²⁺-free Krebs solution with 5mM EGTA (a Ca²⁺chelater), while was not affected by sodium nitroprusside (100 µM, a nitrosovasodialtor). Interestingly, LPA (0.3~3 µM, an LPA receptor agonist) also dose-dependently enhanced the CA secretion from the adrenal medulla, but this facilitatory effect of LPA was greatly inhibited in the presence of Ki 14625 (10 µM). Moreover, acetylcholine (AC)-evoked CA secretion was greatly potentiated during the perfusion of gintonin (3 µg/ml). Taken together, these results demonstrate the first evidence that gintonin increases the CA secretion from the perfused rat adrenal medulla in a dose-dependent fashion. This facilitatory effect of gintonin seems to be associated with activation of LPA- and cholinergic-receptors, which are relevant to the cytoplasmic Ca²⁺ increase by stimulation of the Ca²⁺ influx as well as by the inhibition of Ca²⁺ uptake into the cytoplasmic Ca²⁺ stores, without the increased nitric oxide (NO). Based on these results, it is thought that gintonin, one of ginseng components, can elevate the CA secretion from adrenal medulla by regulating the Ca²⁺ mobilization for exocytosis, suggesting facilitation of cardiovascular system. Also, these findings show that gintonin might be at least one of ginseng-induced hypertensive components.

Histopathological Differential Diagnosis of Psoriasis and Seborrheic Dermatitis of the Scalp

BACKGROUND: The differential diagnosis of psoriasis and seborrheic dermatitis can be difficult when both conditions are localized to the scalp without the involvement of other skin sites. OBJECTIVE: We aimed to evaluate the histopathological differences between psoriasis and seborrheic dermatitis on the scalp and identify favorable criteria for their differential diagnosis. METHODS: We evaluated 15 cases of psoriasis and 20 cases of seborrheic dermatitis of the scalp that had been clinicopathologically diagnosed. Skin biopsy sections stained with H&E were examined. Additional immunohistochemistry was performed, including Ki-67, keratin 10, caspase-5, and GLUT-1. RESULTS: On histopathological examination, mounds of parakeratosis with neutrophils, spongiform micropustules of Kogoj, and clubbed and evenly elongated rete ridges were significantly more frequently observed in psoriasis. Follicular plugging, shoulder parakeratosis and prominent lymphocytic exocytosis were significantly more common in seborrheic dermatitis. Moreover, significantly higher mitotic figures were observed in psoriatic lesions than in seborrheic dermatitis. Immunohistochemistry did not show any difference between psoriasis and seborrheic dermatitis. CONCLUSION: Histopathological features favoring psoriasis include mounds of parakeratosis with neutrophils, spongiform micropustules of Kogoj, clubbed and evenly elongated rete ridges, and increased mitotic figures (≥6/high-powered field). Features indicating seborrheic dermatitis are follicular plugging, shoulder parakeratosis and prominent lymphocytic exocytosis. Immunohistochemistry was not helpful in differentiating psoriasis from seborrheic dermatitis.

Insulin replacement restores the vesicular secretory apparatus in the diabetic rat lacrimal gland / Reposição de insulina restaura o mecanismo secretório da glândula lacrimal de ratos diabéticos

ABSTRACT Purpose: In the lacrimal gland (LG) acinar cells, signaling regulates the release of secretory vesicles through specific Rab and SNARE exocytotic proteins. In diabetes mellitus (DM), the LGs are dysfunctional. The aim of this work was to determine if secretory apparatus changes were associated with any effects on the secretory vesicles (SV) in diabetic rats as well as the expression levels of constituent Rab and members of the SNARE family, and if insulin supplementation reversed those changes. Methods: DM was induced in male Wistar rats with an intravenous dose of streptozotocin (60 mg/kg). One of the two diabetic groups was then treated every other day with insulin (1 IU). A third control group was injected with vehicle. After 10 weeks, Western blotting and RT-PCR were used to compared the Rab and SNARE secretory factor levels in the LGs. Transmission electron microscopy evaluated acinar cell SV density and integrity. Results: In the diabetes mellitus group, there were fewer and enlarged SV. The Rab 27b, Rab 3d, and syntaxin-1 protein expression declined in the rats with diabetes mellitus. Insulin treatment restored the SV density and the Rab 27b and syntaxin expression to their control protein levels, whereas the Vamp 2 mRNA expression increased above the control levels. Conclusions: Diabetes mellitus LG changes were associated with the declines in protein expression levels that were involved in supporting exocytosis and vesicular formation. They were partially reversed by insulin replacement therapy. These findings may help to improve therapeutic management of dry eye in diabetes mellitus. .

RESUMO Objetivo: Células acinares da glândula lacrimal (GL) sinalizam a regulação da liberação através de vesículas secretórias específicas Rab proteínas exocitóticas SNARE. No diabetes mellitus (DM), as glândulas lacrimais são disfuncionais. O objetivo deste trabalho foi determinar se em ratos diabéticos, alterações dos aparatos secretórios estão associados a efeitos sobre vesículas secretoras (VS) e sobre os níveis de expressão do constituinte Rab, bem como membros da família SNARE, e se a suplementação de insulina reverte as alterações. Métodos: DM foi induzido em ratos Wistar machos com uma dose intravenosa de estreptozotocina (60 mg/kg). Um dos dois grupos diabéticos foi então tratado a cada dois dias com insulina (1 UI). Um terceiro grupo controle foi injetado com o veículo. Após 10 semanas, western blot e RT-PCR comparou níveis de fatores secretórios de Rab e SNARE na glândula lacrimal. Microscopia eletrônica de transmissão (MET) avaliaram a densidade e integridade de VS de célula acinar. Resultados: No grupo diabetes mellitus , houve poucas e alargadas VS. Rab27b, Rab 3d e Sintaxina-1 diminuiu a expressão da proteína em ratos com Diabetes Mellitus. O tratamento com insulina restaurou a densidade das VS e expressão de Rab 27b e Sintaxina para seus níveis de proteína controle, enquanto a expressão de Vamp 2 RNAm aumentou em relação aos controles. Conclusões: Alterações na glândula lacrimal de diabetes mellitus estão associadas a reduções nos níveis de expressão de proteínas envolvidas no apoio a exocitose e formação vesicular. Eles são, em parte, revertida por terapia de reposição de insulina. Estes resultados podem ajudar a melhorar a conduta terapêutica do olho seco no diabetes mellitus. .

Hematopoietic cell transplantation for hemophagocytic lymphohistiocytosis: recent advances and controversies

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory clinical syndrome of uncontrolled immune response which results in hypercytokinemia due to underlying primary or secondary immune defect. A number of genetic defects in transport, processing and function of cytotoxic granules which result in defective granule exocytosis and cytotoxicity of cytotoxic T lymphocytes (CTL) and natural killer (NK) cells have been well identified at the cellular and molecular level. Important advances have been made during the last 20 years in the diagnosis and treatment of HLH. The Histiocyte Society has proposed diagnostic guideline using both clinical and laboratory findings in HLH-2004 protocol, and this has been modified partly in 2009. HLH used to be a fatal disease, but the survival of HLH patients has improved to more than 60% with the use of chemoimmunotherapy combined with hematopoietic cell transplantation (HCT) over the past 2 decades. However, HCT is still the only curative option of treatment for primary HLH and refractory/relapsed HLH after proper chemoimmunotherapy. The outcome of HCT for HLH patients was also improved steadily during last decades, but HCT for HLH still carries significant mortality and morbidity. Moreover, there remain ongoing controversies in various aspects of HCT including indication of HCT, donor selection, timing of HCT, conditioning regimen, and mixed chimerism after HCT. This review summarized the important practical issues which were proven by previous studies on HCT for HLH, and tried to delineate the controversies among them.

Activation of MAPK Is Required for ROS Generation and Exocytosis in HMC-1 Cells Induced by Trichomonas vaginalis-Derived Secretory Products

Trichomonas vaginalis is a flagellated protozoan parasite that causes vaginitis and cervicitis in women and asymptomatic urethritis and prostatitis in men. Mast cells have been reported to be predominant in vaginal smears and vaginal walls of patients infected with T. vaginalis. Mitogen-activated protein kinase (MAPK), activated by various stimuli, have been shown to regulate the transcriptional activity of various cytokine genes in mast cells. In this study, we investigated whether MAPK is involved in ROS generation and exocytotic degranulation in HMC-1 cells induced by T. vaginalis-derived secretory products (TvSP). We found that TvSP induces the activation of MAPK and NADPH oxidase in HMC-1 cells. Stimulation with TvSP induced phosphorylation of MAPK and p47phox in HMC-1 cells. Stimulation with TvSP also induced up-regulation of CD63, a marker for exocytosis, along the surfaces of human mast cells. Pretreatment with MAPK inhibitors strongly inhibited TvSP-induced ROS generation and exocytotic degranulation. Finally, our results suggest that TvSP induces intracellular ROS generation and exocytotic degranulation in HMC-1 via MAPK signaling.

Chronic maxillary sinusitis caused by root canal overfilling of Calcipex II

This is a case report of chronic maxillary sinusitis caused by root canal overfilling of Calcipex II (Techno-Dent). A 60 year-old male complained of dull pain in the right maxillary molar area after complicated endodontic treatment using Calcipex II paste and was finally diagnosed with a chronic maxillary sinusitis through a clinical and radiological observation. In the biopsy examination, the periapical granuloma contained a lot of dark and translucent Calcipex II granules which were not stained with hematoxylin and eosin. They were usually engulfed by macrophages but rarely resorbed, resulting in scattering and migrating into antral mucosa. Most of the Calcipex II granules were also accumulated in the cytoplasms of secretory columnar epithelial cells, and small amount of Calcipex II granules were gradually secreted into sinus lumen by exocytosis. However, chronic granulomatous inflammation occurred without the additional recruitment of polymorphonuclear leukocytes (PMNs) and lymphocytes, and many macrophages which engulfed the Calcipex II granules were finally destroyed in the processes of cellular apoptosis. It is presumed that Calcipex II granules are likely to have a causative role to induce the granulomatous foreign body inflammation in the periapical region, and subsequently to exacerbate the chronic maxillary sinusitis in this study.

Eczematid-like Purpura of Doucas and Kapetanakis Showing Clinical Improvement with Narrowband UVB / 대한피부과학회지

Eczematid-like purpura of Doucas and Kapetanakis is a type of pigmented purpuric dermatoses. It is clinically characterized by pruritic seasonal eruptions occurring in the spring and summer, and histopathologically characterized by spongiosis and parakeratosis in the epidermis and by the lymphocyte-mediated leakage of erythrocytes from capillaries in the papillary dermis. We report a case of eczematid-like purpura of Doucas and Kapetanakis that showed clinical improvement with narrowband UVB (NB-UVB). The patient was a 66-year-old man with pruritic, well-demarcated scaly purpuric patches on his feet that appeared 2 months prior. A histopathological study showed mild superficial perivascular lymphocytic infiltration, focal spongiosis with exocytosis, and erythrocyte leakage. We initiated treatment with an oral antihistamine, ascorbic acid, and a topical steroid, but the lesion was aggravated. We therefore treated the patient with NB-UVB for 6 months, and the lesions regressed progressively with residual postinflammatory hyperpigmentation.

A Clinical and Histopathologic Study of Lichen Striatus according to the Clinical Type and Age / 대한피부과학회지

BACKGROUND: Lichen striatus is an uncommon, self-limiting, linear inflammatory disease occurring along the lines of Blaschko, mainly affecting children, and is diagnosed by clinical history and histopathological study of typical lesions. However, various aspects of the histopathologic findings have not yet been studied sufficiently. OBJECTIVE: The aim of this study was to investigate the clinical and histopathologic characteristics of lichen striatus in Korea, according to age and clinical subtype. METHODS: This retrospective study on lichen striatus was performed at our center; clinical and histopathologic findings from 32 patients were evaluated. RESULTS: In all, 22 children and 10 adults were included. The lesions were predominantly distributed on the extremities (78.1%), including those that showed multiregional involvement. Twenty-four patients had erythematous papular lichen striatus (75%), and eight had hypopigmented macular type lesions (25%). All cases of hypopigmented macular subtypes had occurred in children. The histopathologic features of lichen striatus included basal vacuolar degeneration (93.3%), hyperkeratosis (83.3%), spongiosis (63.3%), and exocytosis of lymphocytes (63.3%) in the epidermis. Superficial and deep perivascular lymphocytic inflammatory infiltration (96.7%), lichenoid lymphohistiocytic infiltration (76.7%), and periappendageal involvement (53.3%) in the dermis were also observed. Papular lesions showed greater spongiosis, exocytosis, dyskeratosis, and vacuolar degeneration than hypopigmented lesions. Increased dyskeratosis and pigmentary incontinence as well as more severe lichenoid infiltration were observed in the adults. CONCLUSION: This study provides the first national data about the clinical and histopathologic characteristics of lichen striatus in adults and children. Some of the clinical and histopathologic characteristics differed according to the age group as well as clinical subtype.

Regulation of Mucin Exocytosis in Airway Secretory Cells / 대한이비인후과학회지

Mucin secretion in the airway epithelium acts as an essential barrier process that protects the upper respiratory tract from inhaled particles, environmental pathogens and toxicants. However, dysregulated mucin secretion contributes to pathophysiologic conditions such as rhinitis, asthma, and chronic obstructive pulmonary disease etc. The study on mucin hypersecretion has long been worked, but the exact molecular composition and mechanism for exocytic machinery remain mostly to be elucidated. The regulated mucin secretion, highly coordinated process, is mediated by the cooperative interaction of several proteins existing in the secretory granule, cytoplasm, and plasma membrane. This review provides the information on molecular components of the core exocytic machinery and their functional roles for mucin exocytosis in airway secretory cells.

Signaling mechanisms of glucose-induced F-actin remodeling in pancreatic islet beta cells

The maintenance of whole-body glucose homeostasis is critical for survival, and is controlled by the coordination of multiple organs and endocrine systems. Pancreatic islet beta cells secrete insulin in response to nutrient stimuli, and insulin then travels through the circulation promoting glucose uptake into insulin-responsive tissues such as liver, skeletal muscle and adipose. Many of the genes identified in human genome-wide association studies of diabetic individuals are directly associated with beta cell survival and function, giving credence to the idea that beta-cell dysfunction is central to the development of type 2 diabetes. As such, investigations into the mechanisms by which beta cells sense glucose and secrete insulin in a regulated manner are a major focus of current diabetes research. In particular, recent discoveries of the detailed role and requirements for reorganization/remodeling of filamentous actin (F-actin) in the regulation of insulin release from the beta cell have appeared at the forefront of islet function research, having lapsed in prior years due to technical limitations. Recent advances in live-cell imaging and specialized reagents have revealed localized F-actin remodeling to be a requisite for the normal biphasic pattern of nutrient-stimulated insulin secretion. This review will provide an historical look at the emergent focus on the role of the actin cytoskeleton and its regulation of insulin secretion, leading up to the cutting-edge research in progress in the field today.

LRRK2 phosphorylates Snapin and inhibits interaction of Snapin with SNAP-25

Leucine-rich repeat kinase 2 (LRRK2) is a gene that, upon mutation, causes autosomal-dominant familial Parkinson's disease (PD). Yeast two-hybrid screening revealed that Snapin, a SNAP-25 (synaptosomal-associated protein-25) interacting protein, interacts with LRRK2. An in vitro kinase assay exhibited that Snapin is phosphorylated by LRRK2. A glutathione-S-transferase (GST) pull-down assay showed that LRRK2 may interact with Snapin via its Ras-of-complex (ROC) and N-terminal domains, with no significant difference on interaction of Snapin with LRRK2 wild type (WT) or its pathogenic mutants. Further analysis by mutation study revealed that Threonine 117 of Snapin is one of the sites phosphorylated by LRRK2. Furthermore, a Snapin T117D phosphomimetic mutant decreased its interaction with SNAP-25 in the GST pull-down assay. SNAP-25 is a component of the SNARE (Soluble NSF Attachment protein REceptor) complex and is critical for the exocytosis of synaptic vesicles. Incubation of rat brain lysate with recombinant Snapin T117D, but not WT, protein caused decreased interaction of synaptotagmin with the SNARE complex based on a co-immunoprecipitation assay. We further found that LRRK2-dependent phosphorylation of Snapin in the hippocampal neurons resulted in a decrease in the number of readily releasable vesicles and the extent of exocytotic release. Combined, these data suggest that LRRK2 may regulate neurotransmitter release via control of Snapin function by inhibitory phosphorylation.