Actividad de una esfingomielinasa ácida tipo C producida por Mycobacterium tuberculosis / An acidic sphingomyelinase Type C activity from Mycobacterium tuberculosis

Sphingomyelinases (SMases) catalyze the hydrolysis of sphingomyelin to ceramide and phosphorylcholine. Sphingolipids are recognized as diverse and dynamic regulators of a multitude of cellular processes mediating cell cycle control, differentiation, stress response, cell migration, adhesion, and apoptosis. Bacterial SMases are virulence factors for several species of pathogens. Whole cell extracts of Mycobacterium tuberculosis strains H37Rv and CDC1551 were assayed using [N-methyl-14C]-sphingomyelin as substrate. Acidic Zn2+-dependent SMase activity was identified in both strains. Peak SMase activity was observed at pH 5.5. Interestingly, overall SMase activity levels from CDC1551 extracts are approximately 1/3 of those of H37Rv. The presence of exogenous SMase produced by M. tuberculosis during infection may interfere with the normal host inflammatory response thus allowing the establishment of infection and disease development. This Type C activity is different from previously identified M. tuberculosis SMases. Defining the biochemical characteristics of M. tuberculosis SMases helps to elucidate the roles that these enzymes play during infection and disease.

Las esfingomielinasas (SMasas) catalizan la hidrólisis de esfingomielina a ceramida y fosforilcolina. Los esfingolípidos son reconocidos como reguladores diversos y dinámicos de una multitud de procesos celulares que median en el control del ciclo celular, la diferenciación, la respuesta al estrés, la migración celular, la adhesión y la apoptosis. Las esfingomielinasas bacterianas son factores de virulencia reconocidos en varias especies de patógenos. En este trabajo se analizaron los extractos de células enteras de las cepas de Mycobacterium tuberculosis H37Rv y CDC1551 utilizando [N-metil-14C]-esfingomielina como sustrato. Se identificó actividad de SMasa-ácida dependiente de zinc en ambas cepas. La actividad máxima se observó a pH 5.5. Curiosamente, los niveles de actividad de SMasa generados a partir de extractos de la cepa CDC1551 son aproximadamente un tercio de los de la cepa H37Rv. La presencia de una SMasa exógena producida por M. tuberculosis durante la infección puede interferir con la respuesta inflamatoria del huésped, permitiendo así el establecimiento de la infección y el desarrollo de la enfermedad. Esta actividad tipo C es distinta de las actividades previamente reportadas para M. tuberculosis. Definir las características bioquímicas de las esfingomielinasas de M. tuberculosis ayudará a dilucidar el papel que desempeñan estas enzimas durante la infección y la enfermedad.

Effect of jianpi-jiedu formula on tumor angiogenesis-relevant genes expression in colorectal cancer / 中南大学学报(医学版)

To investigate the effect of the jianpi-jiedu formula (JPJD) on the expression of angiogenesis-relevant genes in colon cancer.
 Methods: Crude extract was obtained from JPJD by water extract method. The effect of JPJD crude extract on colon cancer cell proliferation capacity was determined by MTT assays. The IC50 value was calculated by GraphPad Prism5 software. Affymetrix gene expression profiling chip was used to detect significant differences in expressions of genes after JPJD intervention, and pathway enrichment analysis was performed to analyze the differentially expressed genes. Ingenuity Pathway Analysis software was applied to analyze differentially expressed genes relevant to tumor angiogenesis based on mammalian target of rapamycin (mTOR) signaling pathway and then the network diagram was built. Western blot was used to verify the protein levels of key genes related to tumor angiogenesis.
 Results: JPJD crud extract inhibited the proliferation capacity in colon cancer cells. The IC50 values in 24, 48, and 72 hours after treatment were 13.060, 9.646 and 8.448 mg/mL, respectively. The results of chip showed that 218 genes significantly upgraded, and 252 genes significantly downgraded after JPJD treatment. Most of the genes were related to the function of biosynthesis, metabolism, cell apoptosis, antigen extraction, angiogenesis and so on. There were 12 differentially expressed angiogenesis genes. IPA software analysis showed that the JPJD downregulated expression of sphingomyelin phosphodiesterase 3 (SMPD3), VEGF, vascular endothelial growth factor A (VEGFA), integrin subunit alpha 1 (ITGA1), cathepsin B (CTSB), and cathepsin S (CTSS) genes, while upregulated expressions of GAB2 and plasminogen activator, urokinase receptor (PLAUR) genes in the colorectal cancer cell. Western blot results demonstrated that JPJD obviously downregulated expressions of phospho-mTOR (P-mTOR), signal transducer and activator of transcription 3 (STAT3), hypoxia inducible factor-1α (HIF-1α), and VEGF proteins, while obviously upregulated the level of phospho-P53 (P-P53) protein.
 Conclusion: JPJD may inhibit colorectal tumor angiogenesis through regulation of the mTOR-HIF-1α-VEGF signal pathway.

Neutral Sphingomyelinase and Breast Cancer Research

Our understanding of the functions of neutral sphingomyelinase (N-SMase) signaling has advanced over the past decade. In this review, we focus on the roles and regulation of N-SMase 1, N-SMase 2, N-SMase 3, an enzyme that generates the bioactive lipid ceramide through the hydrolysis of the membrane lipid sphingomyelin. A large body of work has now implicated N-SMase 2 in a diverse set of cellular functions, physiological processes, and disease pathologies. We focus on different aspects of this enzyme's regulation from transcriptional, post-translational, and biochemical. Furthermore, we expected N-SMase involvement in cellular processes including inflammatory signaling, cell growth, apoptosis, and tumor necrosis factor which in turn play important roles in pathologies such as cancer metastasis, variable disease, and other organ system disorders. Lastly, we examine avenues where targeted N-SMase inhibition may be clinically beneficial in disease scenarios.

Vitamin C Stimulates Epidermal Ceramide Production by Regulating Its Metabolic Enzymes

Ceramide is the most abundant lipid in the epidermis and plays a critical role in maintaining epidermal barrier function. Overall ceramide content in keratinocyte increases in parallel with differentiation, which is initiated by supplementation of calcium and/or vitamin C. However, the role of metabolic enzymes responsible for ceramide generation in response to vitamin C is still unclear. Here, we investigated whether vitamin C alters epidermal ceramide content by regulating the expression and/or activity of its metabolic enzymes. When human keratinocytes were grown in 1.2 mM calcium with vitamin C (50 mug/ml) for 11 days, bulk ceramide content significantly increased in conjunction with terminal differentiation of keratinocytes as compared to vehicle controls (1.2 mM calcium alone). Synthesis of the ceramide fractions was enhanced by increased de novo ceramide synthesis pathway via serine palmitoyltransferase and ceramide synthase activations. Moreover, sphingosine-1-phosphate (S1P) hydrolysis pathway by action of S1P phosphatase was also stimulated by vitamin C supplementation, contributing, in part, to enhanced ceramide production. However, activity of sphingomyelinase, a hydrolase enzyme that converts sphingomyelin to ceramide, remained unaltered. Taken together, we demonstrate that vitamin C stimulates ceramide production in keratinocytes by modulating ceramide metabolic-related enzymes, and as a result, could improve overall epidermal barrier function.

Comparative effect of dietary borage oil and safflower oil on anti-proliferation and ceramide metabolism in the epidermis of essential fatty acid deficient guinea pigs / 한국영양학회지

PURPOSE: Borage oil (BO) and safflower oil (SO) are efficacious in reversing epidermal hyperproliferation, which is caused by the disruption of epidermal barrier. In this study, we compared the antiproliferative effect of dietary BO and SO. Altered metabolism of ceramide (Cer), the major lipid of epidermal barrier, was further determined by measurement of epidermal levels of individual Cer, glucosylceramide (GlcCer), and sphingomyelin (SM) species, and protein expression of Cer metabolizing enzymes. METHODS: Epidermal hyperproliferation was induced in guinea pigs by a hydrogenated coconut diet (HCO) for 8 weeks. Subsequently, animals were fed diets of either BO (group HCO + BO) or SO (group HCO + SO) for 2 weeks. As controls, animals were fed BO (group BO) or HCO (group HCO) diets for 10 weeks. RESULTS: Epidermal hyperproliferation was reversed in groups HCO + BO (67.6% of group HCO) and HCO + SO (84.5% of group HCO). Epidermal levels of Cer1/2, GlcCer-A/B, and beta-glucocerebrosidase (GCase), an enzyme of GlcCer hydrolysis for Cer generation, were higher in group HCO + BO than in group HCO, and increased to levels similar to those of group BO. In addition, epidermal levels of SM1, serine palmitoyltransferase (SPT), and acidic sphingomyelinase (aSMase), enzymes of de novo Cer synthesis and SM hydrolysis for Cer generation, but not of Cer3-7, were higher in group HCO + BO than in group HCO. Despite an increase of SPT and aSMase in group HCO + SO to levels higher than in group HCO, epidermal levels of Cer1-7, GlcCer-A/B, and GCase were similar in these two groups. Notably, acidic ceramidase, an enzyme of Cer degradation, was highly expressed in group HCO + SO. Epidermal levels of GlcCer-C/D and SM-2/3 did not differ among groups. CONCLUSION: Dietary BO was more prominent for reversing epidermal hyperproliferation by enhancing Cer metabolism with increased levels of Cer1/2, GlcCer-A/B, and SM1 species, and of GCase proteins.

Computerized Tomography Contrast Induced Nephropathy (CIN) among adult inpatients / Nefropatia induzida por contraste (NIC) em pacientes adultos internados submetidos à tomografia computadorizada por contraste

Introduction: Contrast induced nephropathy (CIN) is one of the complications of the use of intravascular contrast agents, being defined as a reduction of the glomerular filtration rate caused by the iodinated contrast. Most CIN data derive from the cardiovascular literature, which identified as the most consistent risk factors pre-existing chronic renal insufficiency and diabetes mellitus. However, these studies limit their conclusions to a more specific patient population. Computerized tomography as a cause of CIN has been studied less often. Objective: To report on the incidence of computerized tomography contrast induced nephropathy (CIN) in an inpatient population of a tertiary general hospital, identifying potentially avoidable risk factors. Methods: We performed a prospective cohort study with inpatients admitted at a tertiary hospital requiring contrast-induced CT. The primary outcome was the development of CIN, measure by the alteration of serum creatinine or glomerular filtration rate in 48 or 72 hours. Through clinical interview, we verified possible risk factors and preventive measures instituted by the medical team and their association with development of CIN. Results: Of a total of 410 patients, 35 (8.5%) developed CIN. There was a positive correlation between CIN and the presence of diabetes mellitus (OR = 2.15; 95%CI 1.35-4.06; p = 0.02), heart failure (OR = 2.23; 95%CI 1.18-8.8; p = 0.022), and renal failure (OR = 3.36; 95%CI 1.57- 7.17; p = 0.002) Conclusion: Incidence of CIN varies according to the population. Diabetes mellitus, heart failure and renal failure were independent risk factors for the development of CT-associated CIN. Further studies are needed to better understand and treat CT-associated CIN. .

Introdução: Nefropatia induzida por contraste (NIC) é consequência do uso de meios de contraste intravenoso, sendo definida como uma redução da taxa de filtração glomerular. A maioria dos dados de NIC são da literatura cardiovascular, que identificou como fatores de risco insuficiência renal crônica e diabetes. Entretanto, esses estudos limitam suas conclusões a uma população especifica de pacientes. Tomografia Computadorizada contrastada como causa de NIC foi menos estudada. Objetivo: Reportar incidência de NIC numa população de pacientes internados em hospital terciário submetidos à tomografia computadorizada com contraste, identificando possíveis fatores de risco evitáveis. Métodos: Realizamos um estudo de coorte prospectivo com pacientes internados em hospital terciário e que necessitaram de tomografia computadorizada com contraste. O desfecho primário foi desenvolvimento de NIC, verificado por meio da variação da creatinina sérica ou taxa de filtração glomerular em 48 ou 72 horas. Em entrevista clínica, verificamos possíveis fatores de risco, assim como medidas preventivas instituídas pela equipe médica e suas possíveis associações com desenvolvimento de NIC. Resultados: Do total de 410 pacientes, 35 (8,5%) desenvolveram NIC. Houve correlação positiva entre desenvolvimento de NIC e a presença de diabetes mellitus (OR = 2,15; 95%CI 1,35-4,06; p = 0,02), insuficiência cardíaca (OR = 2,23; 95%CI 1,18-8,8; p = 0,022), e insuficiência renal (OR = 3,36; 95%CI 1,57-7,17; p = 0,002). Conclusão: A incidência de NIC varia de acordo com a população. Diabetes, insuficiência cardíaca e insuficiência renal foram fatores de risco independentes para o desenvolvimento de NIC. Mais estudos são ...

Factores de virulencia de Staphylococcus aureus asociados con infecciones mamarias en bovinos: relevancia y rol como agentes inmunógenos / [Virulence factors of Staphylococcus aureus associated with intramammary infections in cows: relevance and role as immunogens].

Staphylococcus aureus is the most prevalent mastitis pathogen in Argentina and worldwide. Lack of effectiveness of traditional control measures based on milking hygiene and antibiotic therapy against this organism has led to the development of alternatives directed to prevent the disease. Among them, the manipulation of host immune mechanisms through vaccination has been explored. The identification of virulence factors able to stimulate host immune defenses is key to developing a rational vaccine. S. aureus has multiple virulence factors that interact with the host at different stages of an intramammary infection. The use of some of these factors as immunogens has been shown to elicit protective responses in the host. The structure, function, and use as immunogens of S. aureus virulence factors considered to be relevant at different stages of intrammamary infections caused by this organism are reviewed in this article.

New single nucleotide deletion in the SMPD1 gene causes Niemann Pick disease type A in a child from southwest Iran: a case report

Niemann Pick disease [NPD] type A [NPA: MIM #257200] is a lipid storage disorder with an autosomal recessive inheritance and occurrs by defect of the SMPD1 gene encoding sphingomyelinase. Disruption of this enzyme leads to the accumulation of sphingomyelin in brain and liver, which in turn causes dysfunction or damage of tissue. We report firstly a 2.5 year old boy with NPA in southwest Iran. Initially, the diagnosis was resulted on the basis of clinical symptoms. The genomic DNA of the suspected individual was subjected to exon sequencing of the SMPD1 gene. According to the human reference sequence NM_000543.4, a novel single guanine deletion resulting in a frameshift mutation [p.Gly247Alafs*9] was observed in the SMPD1 gene that might be causative for the outcome of the disease. The present report is the first molecular genetics diagnosis of the NPA in southwest Iran. The detected deletion in the SMPD1 gene is remarkable because of its novelty. Despite similar morbidity SGA infants exhibited higher lethal complication rates following delayed meconium passage compared to AGA infants

Expression of ASMase in alcoholic liver fibrosis in rats / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the expression of the lysosomal enzyme acid sphingomyelinase (ASMase) in alcohol-induced hepatic fibrosis using a rat model.</p><p><b>METHODS</b>The model of liver fibrosis was induced by administration of alcohol and high fat diet using 20 rats. Six rats given no alcohol and normal diet served as the control group. Real-time PCR, western blotting, and immunohistochemistry were used to evaluate fibrosis-related changes in the mRNA and protein expressions of ASMase.</p><p><b>RESULTS</b>The fibrotic liver tissues of the model rats showed significantly higher expression levels of ASMase than the non-fibrotic liver tissues of the control rats (P less than 0.05).</p><p><b>CONCLUSION</b>Expression of ASMase is increased in the fibrotic liver tissue of an alcohol-induced hepatic fibrosis rat model, suggesting that this lysosomal enzyme may contribute to development of this disease condition.</p>

Advance in research on regulatory mechanism and functions of neutral sphingomyelinse 2 / 中国医学科学院学报

Neutral sphingomyelinase 2 (nSMase2), which located mainly on the plasma membrane, hydrolyzes sphingomyelin into ceramide and plays an important role in the physiological and pathological regulation of cell apoptosis, cell growth arrest, and inflammation. nSMase2 is also involved in the development of Alzheimer's disease and the bone growth.Under neutral pH and the presence of Ca(2+), Mg(2+), and Mn(+), the activity of nSMase2 is induced by oxidative stress through phosphorylation. Furthermore, the induced interaction of anionic phospholipids and the signaling molecules like receptor for activated C-kinase 1/embryonic ectodermal development with nSMase2 are also crucial mechanisms of protein activation. In the review, recent research advances in the structure and function of nSMase2 and its underlying mechanisms are summarized.

A novel SMPD1 mutation in two Chinese sibling patients with type B Niemann-Pick disease / 中华医学杂志(英文版)

Type B Niemann-Pick disease is an autosomal recessive sphingolipidosis due to mutations in the sphingomyelin phosphodiesterase 1 gene (SMPD1). Here we present molecular findings for two sibling patients. One mutation V36A due to c.107T>C in exon 1 is a single nucleotide polymorphism and the other N522S due to c.1565 A>G in exon 6 is a novel missense mutation. This non-fatal missense mutation leads to –20% residual lysosomal acid sphingomyelinase activity in vitro and only results in hepatosplenomegaly without neurologic involvement.

Analysis of Acid Sphingomyelinase Activity in Dried Blood Spots Using Tandem Mass Spectrometry

BACKGROUND: Niemann Pick disease (NP) is a rare, lysosomal storage disorder due to deficiency of the intra-lysosomal enzyme acid sphingomyelinase (ASM) resulting in intracellular accumulation of sphingomyelin. We evaluated a tandem mass spectrometry (MS/MS) method to analyze ASM activity in dried blood spots (DBS) that may be suitable for laboratory diagnosis of NP including high throughput screening of at-risk populations and potentially for newborn screening. METHODS: ASM activity was measured in 3.2 mm punches from DBS. The eluate was incubated with the ASM substrate (N-Hexanoyl-D-erythro-sphingosylphosphorylcholine [C6-sphingomyelin (C29H59N2O6P)]) and an internal standard (N-butyroyl-D-erythro-sphingosine [C4-ceramide (C22H43NO3)]). ASM product and IS were analyzed using MS/MS in multiple reaction monitoring mode for transitions m/z 370.6>264.3 (ASM internal standard) and m/z 398.6>264.3 (ASM product). RESULTS: ASM activities were stable for up to 2 months at or below 4degrees C. Position of the punch in the DBS and/or hematocrit of the DBS had a limited effect on ASM activities. Both intra- and inter-assay variability were below 10%. There was no carry-over. The median ASM activity in 2,085 newborn infants was 9.5 micromol/h/L (mean 10.6) with a SD of 5.06 micromol/h/L. Six of 2,085 (0.3%) infants were found to have ASM activities below the cut-off of 2.5 micromol/h/L. ASM activities were below the cut-off level in all 10 previously diagnosed cases with NP (range: 0.16 to 2.08 micromol/h/L). CONCLUSIONS: This MS/MS method for the measurement of ASM activity in DBS is robust and suitable for laboratory diagnosis of NP.

Analysis of Acid Sphingomyelinase Activity in Dried Blood Spots Using Tandem Mass Spectrometry

BACKGROUND: Niemann Pick disease (NP) is a rare, lysosomal storage disorder due to deficiency of the intra-lysosomal enzyme acid sphingomyelinase (ASM) resulting in intracellular accumulation of sphingomyelin. We evaluated a tandem mass spectrometry (MS/MS) method to analyze ASM activity in dried blood spots (DBS) that may be suitable for laboratory diagnosis of NP including high throughput screening of at-risk populations and potentially for newborn screening. METHODS: ASM activity was measured in 3.2 mm punches from DBS. The eluate was incubated with the ASM substrate (N-Hexanoyl-D-erythro-sphingosylphosphorylcholine [C6-sphingomyelin (C29H59N2O6P)]) and an internal standard (N-butyroyl-D-erythro-sphingosine [C4-ceramide (C22H43NO3)]). ASM product and IS were analyzed using MS/MS in multiple reaction monitoring mode for transitions m/z 370.6>264.3 (ASM internal standard) and m/z 398.6>264.3 (ASM product). RESULTS: ASM activities were stable for up to 2 months at or below 4degrees C. Position of the punch in the DBS and/or hematocrit of the DBS had a limited effect on ASM activities. Both intra- and inter-assay variability were below 10%. There was no carry-over. The median ASM activity in 2,085 newborn infants was 9.5 micromol/h/L (mean 10.6) with a SD of 5.06 micromol/h/L. Six of 2,085 (0.3%) infants were found to have ASM activities below the cut-off of 2.5 micromol/h/L. ASM activities were below the cut-off level in all 10 previously diagnosed cases with NP (range: 0.16 to 2.08 micromol/h/L). CONCLUSIONS: This MS/MS method for the measurement of ASM activity in DBS is robust and suitable for laboratory diagnosis of NP.

A preliminary study on role of acid sphingomyelinase in receptor clustering induced by 50-Hz magnetic fields / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the relationship among a 50-Hz MF-induced epidermal growth factor receptor (EGFR) clustering, acid sphingomyelinase (A-SMase) and ceramide (CER), and to explore the possible mechanism of receptor clustering.</p><p><b>METHODS</b>Human amnion (FL) cells were exposed to a 50-Hz sinusoidal magnetic field at 0.4 mT for 15 min with or without imipramine, a specific inhibitor of A-SMase and ceramide pretreatment. EGF treatment served as the positive control and DMSO treatment served as the solvent control. The EGFR was labeled with polyclonal anti-EGFR antibody and the clustering of EGFR was analyzed using immunofluorescence and confocal microscopy. The percentage of cells with EGFR clustering was counted and compared.</p><p><b>RESULTS</b>Both EGF treatment and 50-Hz MF exposure could induce EGFR clustering. However, the effect could be eliminated by imipramine pretreatment for 4 hours. When FL cells were incubated with ceramide following the imipramine pretreatment for 30 min, EGFR clustering induced by 50-Hz MF exposure could be recovered.</p><p><b>CONCLUSION</b>EGFR clustering induced by 50-Hz MF depends on A-SMase activity, and ceramide, as the hydrolyzate from A-SMase might participate in the process of EGFR clustering.</p>

A Case of a Korean Adult Affected by Type B Niemann-Pick Disease: Secondary Sea-blue Histiocytosis and Molecular Characterization / 대한진단검사의학회지

Niemann-Pick disease (NPD) is an inherited metabolic disorder caused by a deficiency of the enzyme acid sphingomyelinase coded by SMPD1 gene. In contrast with type A NPD, a severe neurodegenerative disease of infancy, type B NPD patients have little or no neurodegeneration, and frequently survive into adulthood. Although over 100 mutations have been found within the SMPD1 gene causing NPD, there was only one report about SMPD1 mutation status of a Korean NPD patient. We report a case of a 32-yr-old female, who presented with thrombocytopenia without any neurologic involvement. Hepatosplenomegaly was detected by both physical examination and imaging studies, and a thoracic radiograph examination showed a pattern of interstitial lung disease. Biochemical tests revealed increased liver enzymes, cholesterol, triglyceride, and LDL-cholesterol, and decreased HDL-cholesterol. Sea-blue or foamy vacuolated histiocytes occurred in bone marrow and liver. Sequencing analysis of SMPD1 using genomic DNA from peripheral leukocytes identified a compound heterozygote of two mutations at exon 2: p.E246K and p.A357V. The former is a known mutation in an Italian patient, and the latter has not been reported yet. She has received oral rosuvastatin to treat hyperlipidemia at a dose of 10 mg per day for 4 months. This is the second report in which the mutation of SMPD1 gene was detected in a Korean NPD patient. The active genetic analysis of SMPD1 gene in patients with typical findings of type B NPD would enable us to facilitate diagnosis as well as to accumulate data on molecular characteristics of Korean NPD patients.

siRNAs targetting sphingomyelin phosphodiesterase 1 protect mouse oocytes from apoptosis / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the potential of siRNAs targeting sphingomyelin phosphodiesterase 1 (SMPD1) in protecting the oocytes from apoptosis, and explore new approaches to female fertility preservation.</p><p><b>METHODS</b>Chemically synthesized siRNA targeting SMPD1 were introduced into mouse oocytes retrieved by hyperstimulation, and the cell apoptosis was analyzed by comic assay 48 and 72 h later.</p><p><b>RESULTS</b>In the oocytes without any siRNA injection, oocyte DNA damage occurred after 24 h, and large amount of DNA fragments migrated from the cells 48 h later. In oocytes injected with siRNA003, DNA migration decreased significantly as compared with the control and the other two groups injected with siRNA001 and siRNA002 (P<0.01).</p><p><b>CONCLUSION</b>siRNA targeting SMPD1 may protect the oocytes from apoptosis, and has the potential for use in future female fertility preservation.</p>

Comparison of two rat models of IgA nephropathy / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the methods for rapid establishment of rat models of IgA nephropathy.</p><p><b>METHODS</b>Forty female SD rats weighing 160-200 g were randomized into 3 groups. In group A, the rats received intravenous injection of staphylococcal enterotoxin B (SEB) and oral bovine serum albumin (BSA), and in group B, CCl4 was injected subcutaneously in addition to the above treatments; the rats in group C received no treatments to serve as the normal control group. The rats were sacrificed 10 and 14 weeks after the treatment for biochemical testing of the arterial blood and histopathological and IgA immunofluorescence examination of the renal tissues. The twenty-four-hour urine was collected at 10, 12, and 14 weeks after the treatments for detecting the urine proteins.</p><p><b>RESULTS</b>Compared with the control group, the rats in groups A and B showed significantly increased serum creatinine, urine nitrogen and protein levels. Pathological examination of the renal tissue showed mild to moderate mesangial expansion and mesangial cell proliferation in groups A and B, without obvious difference between the two groups; but hematuria and proteinuria occurred earlier in group B with stronger IgA immunofluorescence than in group A.</p><p><b>CONCLUSION</b>Both of the methods used in group A and group B can successfully induce IgA nephropathy in rats, but in group B, hematuria and urineprotein occurs earlier and IgA immunofluorescence is more stronger. Therefore intravenous SEB injection combined with oral BSA and subcutaneous CCl4 administration is a better method for time-efficient establishment of rat models of IgA nephropathy.</p>

Preliminary study on role of lipid rafts in receptor clustering induced by 50 Hz magnetic fields and its mechanism / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the relationship among a 50 Hz magnetic field (MF)-induced epidermal growth factor receptor (EGFR) clustering,lipid rafts and acid sphingomyelinase (ASM), and to explore its possible mechanism.</p><p><b>METHODS</b>Human amnion FL cells were exposed to 50 Hz, 0.4 mT MF for 15 min. EGF treatment was used as positive control. Nystatin was employed to study lipid rafts since it could disrupt lipid rafts structure.The EGF receptors, ASM and lipid rafts were labeled with polyclonal anti-EGFR antibody, anti-ASM antibody and FITC-Cholera toxin B, respectively. The images were observed by laser confocal scanning microscope.</p><p><b>RESULT</b>Both EGF treatment and 50 Hz MF exposure could induce EGFR clustering; however, nystatin pretreatment disrupted this effect. MF exposure turned ASM (labeled with Cy3) from a diffused state in the sham exposure group to a concentrated state on the cell membrane, which co-localized with lipid rafts (labeled with FITC).</p><p><b>CONCLUSION</b>The results suggest that the EGFR clustering induced by 50 Hz MF depends on intact lipid rafts on cellular membrane, and the ASM might participate in the process of EGFR clustering.</p>

An Anesthetic Experience in a Patient with Niemann-Pick Disease: A case report / 대한마취과학회지

Niemann-Pick disease (NPD) is an autosomal recessive, lipid storage disorder caused by the deficiency of the lysosomal enzyme sphingomyelinase or defective cholesterol transport from lysosome to cytosol. The clinical symptoms and signs include dysphagia, loss of motor function, hepatosplenomegaly, recurred respiratory infections, seizure, mental retardation, spasticity, myoclonic jerks and ataxia, but vary depending on the type of this disease. We report a successful anesthetic experience, including endotracheal intubation with Glidescope under propofol and remifentanil infusion without neuromuscular blockade, in a 21-year old woman with Niemann-Pick disease for wound revision of gastrostomy site.

Role of sphingomyelin-MAPKs pathway in heat-induced apoptosis

The role of sphingomyelinase (SMase) activation and mitogen activated protein kinases (MAPKs) activation in cellular apoptosis was investigated during the hyperthermic treatment of HL-60 human leukemia cells. Treating the cells for 1 h at 43oC caused more than 50% of cellular apoptosis within several hours. The neutral-SMase activity in the cells treated for 1 h at 42degrees C was slightly increased but decreased in the cells treated at 43degrees C or 44degrees C for the same period whereas the acid SMase activity was slightly increased after heating the cells at 42degrees C and 43degrees C and markedly increased at 44degrees C for 1 h. Treatment of cells with inhibitors of SMase activation and ceramide formation significantly reduced the heat-induced apoptosis. Three major families of mitogen-activated protein kinases (MAPKs) i.e. ERK1/2, p38 and JNK, were activated by the hyperthermic treatment of cells. Inhibition of ERK1/2 with PD98059 exerted little effect on the heat-induced apoptosis and p38 inhibition with SB203580 slightly lessened apoptosis whereas, inhibition of JNK with SP600125 markedly suppressed the heat-induced apoptosis. These results indicate that heat-shock induced the activation of SMase, particularly acid-SMase, thereby causing apoptosis and that JNK played a pivotal role in heat-induced apoptosis in HL-60 leukemia cells.