Isolation and identification of phytochemicals and biological activities of Hericium ernaceus and their contents in Hericium strains using HPLC/UV analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Hericium ernaceus has been traditionally used for the treatment of dyspepsia, gastric ulcer and enervation in traditional Chinese medicine for a long time.

AIM OF THE STUDY

To examine the effect of Hericium strains on their ability to inhibit LPS and interferon-γ induced NO production in cell culture and the bioassay correlation of hericenone C, D, F, isolated from H. ernaceus.

MATERIALS AND METHODS

Hericenone C, D, F were isolated from H. ernaceus by open column chromatography and identified on the basis of spectroscopic analyses including (1)H NMR, (13)C NMR and MS. The amounts of hericenone C, D, and F in Hericium strains were determined by HPLC/UV analysis. In order to investigate the anti-inflammatory effect of Hericium strains extracts, RAW 264.7 cells were treated with 200μg/mL of Hericium strains extracts for 48h. Cell growth was assessed by MTT assay.

RESULTS

Phytochemical constituents were isolated from H. ernaceus by open column chromatography. Their structures were elucidated as hericenones C, D, and F on the basis of spectroscopic analyses including (1)H NMR, (13)C NMR and MS. The amounts of hericenones C, D, and F in Hericium strains were determined by HPLC/UV analysis. Hericenones C, D, and F contents were highest in Norugungdenglee-2 (8.289±0.593mg/g), KFRI-1453 (4.657±0.462mg/g), and KFRI-1093 (5.408±0.420mg/g) strains, respectively. All Hericium strains extracts tested inhibited the lipopolysaccharide- and interferon-γ-induced inflammatory activity of RAW264.7 cells. The strain KFRI-1093 about 39.6% reduced NO generation with compared to control.

CONCLUSION

We believe that the anti-inflammatory effect of KFRI-1093 was due to hericenone F content. Our results contribute towards validation of the traditional use, natural drugs and health supplements. And also, the developed simple, accurate and rapid LC method can be used determinate the content of hericenones from other Hericium strains.

Hepatoprotective Effect and Synergism of Bisdemethoycurcumin against MCD Diet-Induced Nonalcoholic Fatty Liver Disease in Mice

Nonalcoholic fatty liver disease (NAFLD), the hepatic manifestation of the metabolic syndrome, has become one of the most common causes of chronic liver disease over the last decade in developed countries. NAFLD includes a spectrum of pathological hepatic changes, such as steatosis, steatohepatitis, advanced fibrosis, and cirrhosis. Bisdemethoxycurcumin (BDMC) is polyphenolic compounds with a diarylheptanoid skeleton, curcumin close analogues, which is derived from the Curcumae Longae Rhizoma. While the rich bioavailability research of curcumin, BDMC is the poor studies. We investigated whether BDMC has the hepatoprotective effect and combinatory preventive effect with silymarin on methionine choline deficient (MCD)-diet-induced NAFLD in C57BL/6J mice. C57BL/6J mice were divided into five groups of normal (normal diet without any treatment), MCD diet (MCD diet only), MCD + silymarin (SIL) 100 mg/kg group, MCD + BDMC 100 mg/kg group, MCD + SIL 50 mg/kg + BDMC 50 mg/kg group. Body weight, liver weight, liver function tests, histological changes were assessed and quantitative real-time polymerase chain reaction and Western blot analyses were conducted after 4 weeks. Mice lost body weight on the MCD-diet, but BDMC did not lose less than the MCD-diet group. Liver weights decreased from BDMC, but they increased significantly in the MCD-diet groups. All liver function test values decreased from the MCD-diet, whereas those from the BDMC increased significantly. The MCD- diet induced severe hepatic fatty accumulation, but the fatty change was reduced in the BDMC. The BDMC showed an inhibitory effect on liver lipogenesis by reducing associated gene expression caused by the MCD-diet. In all experiments, the combinations of BDMC with SIL had a synergistic effect against MCD-diet models. In conclusion, our findings indicate that BDMC has a potential suppressive effect on NAFLD. Therefore, our data suggest that BDMC may act as a novel and potent therapeutic agent against NAFLD.

Postharvest strategies for deoxynivalenol and zearalenone reduction in stored adlay (Coix lachryma-jobi L.) grains

Improperly practiced postharvest procedures can pose mycotoxin-related risks in the production of medicinal herbs. As a health food with pharmacological supplements, cereal-based adlay has been broadly used in oriental medical practice. Compared with the standard production protocol, three provisional critical control points (CCPs) in the conventional procedure were identified and assessed for mycotoxin contamination in the adlay from small farms in Korea. Although various mycotoxins were present, the prevalence of deoxynivalenol (DON) or zearalenone (ZEN) was relatively high in the adlay. In terms of drying conditions, field drying in the conventional pathway was associated with more exposure to DON than heated-air drying. Moreover, the DON or ZEN levels in chaff were higher than the levels in the inner grain, suggesting that the hulling process as another CCP would reduce the DON or ZEN exposure. In particular, the DON or ZEN levels in adlay stored for protracted periods without dehulling were very high, but a lower storage temperature of 12°C was not effective at significantly reducing these mycotoxins. In this case, the inner grain was more contaminated with DON or ZEN than the chaff after protracted storage because surface fungi, which produce mycotoxins, can penetrate deep into grain with time. Heated-air drying and nonprotracted storage limited DON contamination in adlay. More importantly, an early dehulling process should be adopted as an easy preventive action to reduce the risk of exposure to DON or ZEN in adlay postharvest. This is monitored as a central CCP for safer production of adlay from local farms.

Microparticle-mediated thrombin generation assay: increased activity in patients with recurrent thrombosis

BACKGROUND

Circulating cell-derived microparticles (MP) are important players in thrombogenesis, attributed in part to tissue factor (TF) carried on them. We developed MP-mediated thrombin generation assay (TGA) and measured a series of patients with thrombosis (TBS) and normal controls (NC).

METHODS

MP were isolated from plasma of 66 patients with TBS and 34 NC. The MP were resuspended in normal pooled particle-free plasma (PFP) containing corn trypsin inhibitor (to inhibit contact pathway). MP mediated TGA yields three parameters: lag time, peak and rate. This method is not influenced by anticoagulant therapy. Of the TBS patients, 41 had only a single thrombosis (S-TBS) and 25 had recurrences (R-TBS) within a 5-year period. In parallel, MP were quantitated by flow cytometry, and cell origin was determined: endothelial cells (EMP), leukocytes (LMP), red cells (RMP) and platelets (PMP).

RESULTS

MP from all TBS patients exhibited higher thrombin generation than NC by all three TGA parameters. R-TBS had significantly greater TGA values than S-TBS, reflected in higher peak and rate, and shorter lag time. MP numbers were also higher in TBS vs. NC, for all MP subtypes, and were significantly higher in R-TBS than S-TBS (except LMP). All MP levels correlated with thrombin generation (P < 0.0001), most closely between PMP and peak (R = 0.47) and rate (R = 0.43).

CONCLUSIONS

MP-mediated TGA is a novel way to assess functional procoagulant activity of MP. Enhanced MP-mediated TGA was demonstrated in TBS patients, and significantly higher activity in R-TBS. These findings support a major role of MP in thrombogenesis.

Increased procoagulant cell-derived microparticles (C-MP) in splenectomized patients with ITP

BACKGROUND

Splenectomy is frequently employed for therapeutic and diagnostic purposes in various clinical disorders. However its long-term safety is not well elucidated. Although risk of infection by encapsulated organisms is widely recognized, less well-known are risks of thrombosis and cardiovascular disease.

METHODS

We investigated levels of cell-derived microparticles (C-MP) in 23 splenectomized ITP (ITP-S) and 53 unsplenectomized ITP patients (ITP-nS). Assay of C-MP derived from platelets (PMP), leukocytes (LMP), red cells (RMP) and endothelial cells (EMP) were performed by flow cytometry. Coagulation parameters included PT, aPTT and activities of FVIII, IX and XI. Results of all measures were compared between the two groups, ITP-S vs ITP-nS.

RESULTS

Levels of all C-MP were higher in ITP-S than ITP-nS but only RMP and LMP reached statistical significance (p = 0.0035 and p < 0.0001, respectively). The aPTT was significantly shorter in ITP-S (p = 0.029). Interestingly, correlation analysis revealed that RMP, but not other C-MP, were associated with shortening of aPTT (p = 0.024) as well as with increased activities of factors VIII (p = 0.023), IX (p = 0.021) and XI (p = 0.0089).

CONCLUSIONS

RMP and LMP were significantly elevated in splenectomized compared to non-splenectomized ITP patients. This suggests that the spleen functions to clear procoagulant C-MP, and that elevation of C-MP might contribute to increased risk of thrombosis, progression of atherosclerosis and cardiovascular disease following splenectomy.

Endothelial microparticles induce formation of platelet aggregates via a von Willebrand factor/ristocetin dependent pathway, rendering them resistant to dissociation

Endothelial microparticles (EMP) released from activated or apoptotic endothelial cells (EC) are emerging as useful markers for detection of EC dysfunction. Our recent observation that EMP carry von Willebrand factor (vWf) led us to investigate their interaction with platelets. EMP were incubated with normal washed platelets in the presence or absence of ristocetin, then platelet aggregates were measured by flow cytometry. In the absence of ristocetin, negligible EMP conjugated with platelets (< 5%) but in the presence of ristocetin (1 mg mL(-1)), EMP induced up to 95% of platelets to aggregate. EMP-platelet interaction was 80% blocked by anti-CD42b, or by 0.1 microm filtration to remove EMP. Platelet aggregates induced by normal plasma or high molecular weight vWf (Humate-P) dissociated 50% within 15-25 min following 1:20 dilution. In contrast, aggregates formed with EMP persisted two- to threefold longer with the same treatment, indicating greater stability. A similar degree of prolongation of dissociation was observed using plasma from thrombotic thrombocytopenic purpura (TTP) patients compared with normal plasma. Addition of EMP to plasma from severe von Willebrand disease restored his ristocetin-induced platelet aggregation. Multimer analysis of vWf on EMP showed unusually large vWf (ULvWf). In summary, EMP carries ULvWf multimers, promote platelet aggregates, and increase the stability of the aggregates thus formed.

Health development experience in North and South Korea

The purpose of this study is to compare the difference in health status between South Koreans and North Koreans and to identify factors responsible for the remarkable improvements in the health status of South Koreans. In order to examine the causes of the difference in health level, the health indices and their determinants of two Koreas were analyzed in time order. As of the year 2000, the average life expectancy at birth is 71.0 years for men and 78.6 years for women in South Korea, which is longer than that of North Korea by 8.1 for men and 11.2 for women. Infant mortality rate in 1998 was 9.0 per 1,000 live births in South Korea and 54.0 in North Korea. Since being liberated from Japanese ruling in 1945, South Korea has achieved remarkable economic growth under democracy and a market economy system. On the other hand, North Korea has maintained a socialistic system. North Korea has suffered from economic crisis since the 1990s. From this point it could be said that economic status is the major factor for the differences in health level between the two Koreas. Economic status not only directly influences health level but also indirectly affects it through influences on nutrition, hygiene, health resources, and other intervening factors. The South Korean government has concentrated its limited resources on public health activities such as tuberculosis control, family planning (FP), and maternal and child health (MCH) programmes whereas the private sector has taken charge of constructing the health delivery system including health facilities and human resources. In order to solve the problem, which might occur in the private-oriented medical care system, the South Korean government has introduced the national health insurance programme and enforced regulation policies. Many developing countries which are suffering from poverty and disease, can learn from the experience of Korea that had suffered from similar problems up to the early 1970s.

Protein kinase Dyrk1 activates cAMP response element-binding protein during neuronal differentiation in hippocampal progenitor cells

Dyrk is a dual specific protein kinase thought to be involved in normal embryo neurogenesis and brain development. Defects/imperfections in this kinase have been suggested to play an important role in the mental retardation of patients with Down's syndrome. The transcriptional factor cAMP response element-binding protein (CREB) has been implicated in the formation of many types of synaptic plasticity, such as learning and memory. In the present study we show that Dyrk1 activity is markedly induced during the differentiation of immortalized hippocampal progenitor (H19-7) cells. The addition of a neurogenic factor, basic fibroblast growth factor, to the H19-7 cells results in an increased specific binding of Dyrk1 to active CREB. In addition, Dyrk1 directly phosphorylates CREB, leading to the stimulation of subsequent CRE-mediated gene transcription during the neuronal differentiation in H19-7 cells. Blockade of Dyrk1 activation significantly inhibits the neurite outgrowth as well as CREB phosphorylation induced by basic fibroblast growth factor. These findings suggest that Dyrk1 activation and subsequent CREB phosphorylation is important in the neuronal differentiation of central nervous system hippocampal cells.

Differential activation of phospholipases by mitogenic EGF and neurogenic PDGF in immortalized hippocampal stem cell lines

In several neuronal systems, nerve growth factor (NGF) and platelet-derived growth factor (PDGF) act as neurogenic agents, whereas epidermal growth factor (EGF) acts as a mitogenic agent. Hippocampal stem cell lines (HiB5) immortalized by the expression of a temperature-sensitive SV40 large T antigen also respond differentially to EGF and PDGF. While EGF treatment at the permissive temperature induces proliferation, the addition of PDGF induces differentiation at the non-permissive temperature. However, the mechanism responsible for these different cellular fates has not been clearly elucidated. In order to clarify possible critical signaling events leading to these distinct cellular outcomes, we examined whether either EGF or PDGF differentially induces the activation of phospholipases, such as phospholipase A(2) (PLA(2)), C (PLC), or D (PLD). Although EGF stimulation did not induce phospholipases, PDGF caused a rapid and transient activation of PLC and PLD, but not PLA(2). When the activation of PLC or PLD was blocked, the neurite outgrowth induced by PDGF was significantly inhibited. Although the activation of PLD occurred faster than PLC, blocking of PLD activity by transient expression of lipase-inactive mutants did not inhibit the induction of PLC activity by PDGF. These results suggest that the differential activation of phospholipases may play an important role in signal transduction by mitogenic EGF and neurotrophic PDGF in HiB5 neuronal hippocampal stem cells. In particular, the activation of phospholipase C and D may contribute to neuronal differentiation by neurogenic PDGF in the HiB5 cells.

Occupational asthma due to formaldehyde

Formaldehyde is a low molecular weight chemical and can elicit acute and chronic health related problems. Most of the inhaled formaldehyde is retained in the upper respiratory tract due to its extraordinary solubility. Therefore, cases of formaldehyde-induced occupational asthma are sporadic despite its widespread use in industrial processes. We herein report upon a case of occupational asthma due to formaldehyde, which was confirmed by workplace challenge including working environmental assessments, and by formaldehyde inhalation challenge using a specially designed closed-circuit apparatus. To investigate the possible involvement of an IgE-mediated mechanism, both in vitro and in vivo tests were done. IgE antibody specific for formaldehyde-human serum albumin conjugate (F-HSA) was not detected by ELISA, and no specific cutaneous reactivity to F-HSA was noted by either skin prick or intradermal test. The patient was diagnosed with formaldehyde-induced occupational asthma not associated with an IgE mediated mechanism.

Zn2+-induced ERK activation mediated by reactive oxygen species causes cell death in differentiated PC12 cells

Recent studies have provided evidence that Zn2+ plays a crucial role in ischemia- and seizure-induced neuronal death. However, the intracellular signaling pathways involved in Zn2+-induced cell death are largely unknown. In the present study, we investigated the roles of mitogen-activated protein kinases (MAPKs), such as c-Jun N-terminal kinase (JNK), p38 MAPK and extracellular signal-regulated kinase (ERK), and of reactive oxygen species (ROS) in Zn2+-induced cell death using differentiated PC12 cells. Intracellular accumulation of Zn2+ induced by the combined application of pyrithione (5 microM), a Zn2+ ionophore, and Zn2+ (10 microM) caused cell death and activated JNK and ERK, but not p38 MAPK. Preventing JNK activation by the expression of dominant negative SEK1 (SEKAL) did not attenuate Zn2+-induced cell death, whereas the inhibition of ERK with PD98059 and the expression of dominant negative Ras mutant (RasN17) significantly prevented cell death. Inhibition of protein kinase C (PKC) and phosphatidylinositol-3 kinase had little effect on Zn2+-induced ERK activation. Intracellular Zn2+ accumulation resulted in the generation of ROS, and antioxidants prevented both the ERK activation and the cell death induced by Zn2+. Therefore, we conclude that although Zn2+ activates JNK and ERK, only ERK contributes to Zn2+-induced cell death, and that ERK activation is mediated by ROS via the Ras/Raf/MEK/ERK signaling pathway.

Induction of neuronal cell death by Rab5A-dependent endocytosis of alpha-synuclein

The presynaptic alpha-synuclein is a prime suspect for contributing to Lewy pathology and clinical aspects of diseases, including Parkinson's disease, dementia with Lewy bodies, and a Lewy body variant of Alzheimer's disease. Here we examined the pathogenic mechanism of neuronal cell death induced by alpha-synuclein. The exogenous addition of alpha-synuclein caused a marked decrease of cell viability in primary and immortalized neuronal cells. The neuronal cell death appeared to be correlated with the Rab5A-specific endocytosis of alpha-synuclein that subsequently caused the formation of Lewy body-like intracytoplasmic inclusions. This was further supported by the fact that the expression of GTPase-deficient Rab5A resulted in a significant decrease of its cytotoxicity as a result of incomplete endocytosis of alpha-synuclein.

IFN-gamma induces cell death in human hepatoma cells through a TRAIL/death receptor-mediated apoptotic pathway

We demonstrated the induction of cell death in a hepatoma cell line by IFN-gamma and its possible mechanism. Among the 2 hepatitis B virus (HBV)-associated hepatoma cell lines, SNU-354 and SNU-368, IFN-gamma induced cell death and increased caspase-3 activity in SNU-368 but not in SNU-354. IFN-gamma induced several changes in the mRNA expression level of apoptosis-regulating genes, e.g., increased expression of Fas, caspase-1 and TNF-related apoptosis-inducing ligand (TRAIL). In particular, IFN-gamma potently increased the mRNA expression of TRAIL in both cell lines. However, it did not change the mRNA expression level of death-mediating TRAIL receptors, e.g., DR4 and DR5, which were constitutively expressed in both cell lines. In contrast, the decoy receptor DcR1 was expressed in SNU-354 but not in SNU-368, and its expression level in SNU-354 was increased by IFN-gamma. Another decoy receptor, DcR2, was constitutively expressed in both cell lines; however, its expression level in SNU-368 was decreased by IFN-gamma. In addition, exogenous recombinant TRAIL reduced viability in SNU-368, but not in SNU-354, cells. From these findings, we speculated that TRAIL up-regulation and the subsequent TRAIL-mediated apoptosis serve as a mechanism of IFN-gamma-induced cell death in SNU-368. To confirm this hypothesis, we demonstrated that soluble DR4-Fc fusion protein, a TRAIL pathway inhibitor, inhibited IFN-gamma-induced cell death in SNU-368. Our results demonstrated that IFN-gamma acts as an inducer of cell death through TRAIL-mediated apoptosis.

Elevated plasma endothelial microparticles in multiple sclerosis

OBJECTIVE

To assess endothelial dysfunction in patients with MS and to investigate whether plasma from patients with MS induces endothelial cell dysfunction in vitro.

BACKGROUND

Endothelial cell dysfunction may contribute to the pathogenesis of MS. Elevations of soluble adhesion molecules intracellular adhesion molecule, vascular cell adhesion molecule, and platelet-endothelial cell adhesion molecule-1 (CD31) have been reported as markers of blood-brain barrier (BBB) damage in MS, but direct assay of endothelium has been difficult. Endothelial cells release microparticles < approximately 1.5 microm (EMP) during activation or apoptosis. The authors developed a flow cytometric assay of EMP and studied EMP as markers of endothelial damage in MS.

METHODS

Platelet-poor plasma (PPP) from 50 patients with MS (30 in exacerbation and 20 in remission) and 48 controls were labeled with fluorescein isothiocyanate (FITC)-conjugated anti-CD31 and anti-CD51 (vitronectin receptor) antibodies, and two classes of EMP (CD31+ and CD51+) were assayed by flow cytometry. For in vitro studies, patients' plasma was added to the microvascular endothelial cell (MVEC) culture and release of CD31+ and CD51+ EMP were measured in the supernatant.

RESULTS

Plasma from patients in exacerbation had 2.85-fold elevation of CD31+ EMP as compared with healthy controls, returning to near control value during remission. The CD31+ EMP concentration showed a positive association with gadolinium enhancement in patients with MS. In contrast, CD51+ EMP remained elevated in both exacerbation and remission. This suggests that CD31+ EMP is a marker of acute injury, whereas CD51+ EMP reflects chronic injury of endothelium. MS plasma induced release of both CD31+ and CD51+ EMP from MVEC culture in vitro.

CONCLUSION

Endothelial dysfunction is evident during exacerbation of MS, evidenced by shedding of EMP expressing PECAM-1 (CD31). The in vitro data indicate contribution of one or more plasma factors in endothelial dysfunction of MS.

Basic fibroblast growth factor-induced activation of novel CREB kinase during the differentiation of immortalized hippocampal cells

Growth factors bind to their specific receptors on the responsive cell surface and thereby initiate dramatic changes in the proliferation, differentiation, and survival of their target cells. In the present study we have examined the mechanism by which growth factor-induced signals are propagated to the nucleus, leading to the activation of transcription factor, cis-acting cAMP response element (CRE)-binding protein (CREB), in immortalized hippocampal progenitor cells (H19-7). During the differentiation of H19-7 cells by basic fibroblast growth factor (bFGF) a critical regulatory Ser(133) residue of CREB was phosphorylated followed by an increase of CRE-mediated gene transcription. Expression of S133A CREB mutants blocked the differentiation of H19-7 cells by bFGF. Although the kinetics of CREB phosphorylation by EGF was transient, bFGF induced a prolonged pattern of CREB phosphorylation. Interestingly, bFGF-induced CREB phosphorylation and subsequent CRE-mediated gene transcription is not likely to be mediated by any of previously known signaling pathways that lead to phosphorylation of CREB, such as mitogen-activated protein kinases, protein kinase A, protein kinase C, phosphatidylinositol 3-kinase-p70(S6K), calcium/calmodulin dependent protein kinase, and casein kinase 2. By using in vitro in gel kinase assay the presence of a novel 120-kDa bFGF-inducible CREB kinase was identified. These findings identify a new growth factor-activated signaling pathway that regulates gene expression at the CRE.

Intracellular calcium mobilization induces immediate early gene pip92 via Src and mitogen-activated protein kinase in immortalized hippocampal cells

Regulation of intracellular calcium levels plays a central role in cell survival, proliferation, and differentiation. A cell-permeable, tumor-promoting thapsigargin elevates the intracellular calcium levels by inhibiting endoplasmic reticulum Ca(2+)-ATPase. The Src-tyrosine kinase family is involved in a broad range of cellular responses ranging from cell growth and cytoskeletal rearrangement to differentiation. The immediate early gene pip92 is induced in neuronal cell death as well as cell growth and differentiation. To resolve the molecular mechanism of cell growth by intracellular calcium mobilization, we have examined the effect of thapsigargin and subsequent intracellular calcium influx on pip92 expression in immortalized rat hippocampal H19-7 cells. An increase of intracellular calcium ion levels induced by thapsigargin stimulated the expression of pip92 in H19-7 cells. Transient transfection of the cells with kinase-inactive mitogen-activated protein kinase kinase (MEK) and Src kinase or pretreatment with the chemical MEK inhibitor PD98059 significantly inhibited pip92 expression induced by thapsigargin. When constitutively active v-Src or MEK was overexpressed, the transcriptional activity of the pip92 gene was markedly increased. Dominant inhibitory Raf-1 blocked the transcriptional activity of pip92 induced by thapsigargin. The transcription factor Elk1 is activated during thapsigargin-induced pip92 expression. Taken together, these results suggest that an increase of intracellular calcium ion levels by thapsigargin stimulates the pip92 expression via Raf-MEK-extracellular signal-regulated protein kinase- as well as Src kinase-dependent signaling pathways.

Elevated endothelial microparticles in thrombotic thrombocytopenic purpura: findings from brain and renal microvascular cell culture and patients with active disease

Endothelial injury is believed to be a key initiating event in the pathogenesis of thrombotic thrombocytopenic purpura (TTP), leading to platelet activation and formation of platelet-rich thrombi in microvasculature. However, the nature of endothelial injury in TTP is poorly defined and clinical assays to rapidly and reliably monitor endothelial damage are not readily available. Using flow cytometry, we measured endothelial microparticles (EMPs) generated from cultured renal and brain microvascular endothelial cells (MVECs) during activation and apoptosis, and evaluated the effect of TTP plasma on them. EMPs were measured using positivity for monoclonal antibodies (mAbs) CD31 and CD51, and their procoagulant activity was assessed using a Russell viper venom assay. Both cell lines generated procoagulant EMPs when cultured with inducers of activation (tumour necrosis factor alpha; TNF-alpha) or apoptosis (mitomycin C). TTP plasma induced a five- to sixfold increase of EMP generation and a two- to threefold increase of procoagulant activity in cultured brain and renal MVECs. TTP plasma induced a threefold and 13-fold increase of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expression, respectively, on renal MVECs. Procoagulant activity tended to parallel EMP numbers. The effect of TTP plasma on cell viability was similar to that of TNF-alpha, implying that it induced activation rather than apoptosis. Control plasma and idiopathic thrombocytopenic purpura (ITP) plasma had little effect. In the clinical study, EMP assay of blood from acute TTP patients showed levels markedly elevated compared with normal controls, but values returned to normal in remission. In conclusion, TTP plasma activated and induced injury to MVECs in culture, judged by production of EMP and expression of activation markers. Released procoagulant EMP may play a role in the pathogenesis of TTP. Assay of EMP may be a useful marker of disease activity and endothelial injury in TTP and possibly other thrombotic disorders.

Expression of immediate early gene pip92 during anisomycin-induced cell death is mediated by the JNK- and p38-dependent activation of Elk1

We report here that immediate early gene pip92 is expressed during anisomycin-induced cell death in fibroblast NIH3T3 cells. To determine the mechanism by which this occurs and to identify downstream signaling pathways, we investigated the induction of the pip92 promoter. The activation of pip92 by anisomycin is mediated by the activation of MAP kinases, such as JNK and p38 kinase, but not ERK. Deletion analysis of the pip92 promoter indicated that pip92 activation occurs primarily within the region containing a serum response element (SRE). Further analysis of the SRE using a heterologous thymidine kinase promoter showed that both an Ets and CArG-like site are required for anisomycin-induced pip92 expression. Elk1, which binds to the Ets site, was phosphorylated by the JNK- and p38-dependent pathways and the phosphorylation of Elk1-GAL4 fusion proteins by these pathways was sufficient for the transactivation. Overall, this study suggested that different MAPK pathways are involved in the expression of immediate early gene pip92 by growth factors and environmental stresses.

A systemic administration of NMDA induces immediate early gene pip92 in the hippocampus

In the mammalian CNS, aspartate and glutamate are major excitatory amino acids, and their receptors are believed to mediate a wide range of physiological and pathological processes, including neurotransmission, plasticity, excitotoxicity, and various forms of neurodegeneration. The immediate early gene pip92 has been identified in serum-stimulated BALB/c 3T3 fibroblasts, activated T lymphocytes treated with cycloheximide, and fibroblast growth factor-stimulated hippocampal cells during neuronal differentiation. In this study we have demonstrated that pip92 is expressed in the mouse brain after a single intraperitoneal injection of NMDA. The distribution of pip92 mRNA levels in the NMDA-treated mouse brain was investigated using in situ RT-PCR. The region-specific activation of pip92 in the CNS was observed 3 h after NMDA injection, and high levels of pip92 mRNA were detected in the hippocampal dentate gyrus and piriform cortex regions. In addition, the activation of pip92 by NMDA was mediated by activation of mitogen-activated protein kinases (MAPKs), such as c-Jun N-terminal kinase (JNK) and p38 kinase, but not extracellular signal-regulated kinase (ERK) in the mouse hippocampus and immortalized rat hippocampal progenitor cells. This study suggests that pip92 is likely to play an important role in neuronal cell death induced by excitotoxic NMDA injury in the CNS.

Biphasic effects of dithiocarbamates on the activity of nuclear factor-kappaB

Dithiocarbamates are well-known antioxidants and nuclear factor-kappaB (NF-kappaB) inhibitors. Recently, they have been characterized as zinc ionophores. Concentration-dependent biphasic effects of dithiocarbamates on NF-kappaB activity have been widely reported. We studied the mechanism of this phenomenon in relation to Zn(2+) influx. Two dithiocarbamates, pyrrolidine dithiocarbamate and diethyldithiocarbamate, showed concentration-dependent biphasic effects in inhibiting NF-kappaB activation in cerebral endothelial cells. These unique effects of dithiocarbamates on NF-kappaB were tightly linked to their ability to elevate intracellular Zn(2+)500 microM), dithiocarbamates started to lose their ability to promote Zn(2+) influx and to inhibit NF-kappaB activation. These results might provide insight into the appropriate use of dithiocarbamates in various disorders.

Reduced glutathione oxidation ratio and 8 ohdG accumulation by mild ischemic pretreatment

A critical role of oxidative stress has been implicated in ischemic brain damage. Mild ischemic pretreatment and/or synthesis of heat shock proteins (HSPs) has been suggested to protect against oxidative brain damage. However, experimental support of this suggestion have proven to be difficult partly because sensitive indices to assess oxidative consequences of ischemic brain damage were few. In this study, we have attempted to establish biochemical assay systems to quantitate oxidative brain damage following ischemia. We produced experimental brain ischemia in the Mongolian gerbil (Meriones unguiculatus) and examined the hippocampus for ischemic brain damage. The results obtained from ischemic gerbil hippocampus demonstrated that oxidative brain damage can be quantitated by determining glutathione oxidation ratio together with the accumulation of the oxidative DNA damage product, 8-hydroxy-2'-deoxyguanosine (8 ohdG). Our results also demonstrated a role for mild ischemic pretreatment and synthesis of HSPs against oxidative brain damage. We showed that mild 2-min ischemic pretreatment reduced the degree of both glutathione oxidation ratio and 8 ohdG accumulation in gerbil hippocampus subsequent to 10 min ischemic challenge. We also showed that the accumulation of HSP70 was closely associated with the reduction of oxidative brain damage. To our knowledge, this is the first report to investigate glutathione redox states and oxidative DNA damage levels to evaluate a protective role of mild ischemic pretreatment and HSP synthesis following brain ischemia. Our data validate the previous suggestions and provide new additional data that argue for the protective role of mild ischemic pretreatment and HSP70 synthesis against oxidative brain damage.

Novel biphasic effect of pyrrolidine dithiocarbamate on neuronal cell viability is mediated by the differential regulation of intracellular zinc and copper ion levels, NF-kappaB, and MAP kinases

Nuclear factor kappaB (NF-kappaB) is a transcription factor involved in the expression of a wide range of genes, most of which code for proteins that play a role in immunity and inflammation. Pyrrolidine dithiocarbamate (PDTC) is a well-known inhibitor of NF-kappaB. Although its mechanism of action is conferred by its antioxidant property, other mechanisms by which PDTC can act as a prooxidant, metal chelator, and free thiol group modulator have recently been suggested. Here we report that PDTC caused a dual effect on cell viability in neuronal rat pheochromocytoma (PC12) cells, depending on its concentration. Increase of intracellular zinc and copper ion levels selectively potentiated the cytotoxic PDTC effect in a dose-dependent manner, and thiol reagents, such as glutathione and N-acetylcysteine, as well as divalent metal-chelating reagents, such as EDTA and bathocuproline disulfonic acid, blocked its cell death effect. The differential effect of PDTC on cell viability correlates well with the inhibition of NF-kappaB activities. In addition, PDTC differentially activated microtubule-associated protein (MAP) kinases, such as extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), but not p38, depending on its dose, and the coaddition of glutathione (GSH), other antioxidants, and metal ions also modulated their activities. Furthermore, stable Bcl-2 expression blocked the PDTC-induced cell death. These results suggest that the thiol groups and free zinc and copper ion levels are important for the novel biphasic PDTC effect on cell viability, which is associated with the differential activation of NF-kappaB and MAP kinases.

A flow cytometric assay of platelet activation marker P-selectin (CD62P) distinguishes heparin-induced thrombocytopenia (HIT) from HIT with thrombosis (HITT)

Heparin induced thrombocytopenia (HIT) is a well-known complication of heparin administration but usually resolves upon discontinuation without sequelae. However, a small proportion of HIT patients develop thrombosis associated with HIT, designated as HITT, which is often life-threatening and may lead to gangrene and amputations. Existing laboratory methods of confirming HIT/HITT do not distinguish between HIT and HITT. We report a flow cytometric assay of platelet activation marker CD62P to distinguish the effects of addition of HIT vs. HITT plasma to normal blood. Briefly, normal whole blood was incubated with platelet-poor plasma from 12 patients with HITT, 30 with HIT, and 65 controls, in presence and absence of heparin, and expression of CD62P was assayed by flow cytometry. When the ratios of fluorescent intensity of CD62P with heparin divided by that without heparin were compared, HITT plasma induced significantly higher ratios than HIT plasma (HITT ratios approximately 2.5 vs. HIT ratios approximately 1.2; p <0.001). Eleven of 12 HITT patients were positive by this test but only 5 of 30 HIT patients were positive (p <0.0005). In a case of HIT with silent thrombosis, this assay gave a positive results prior to clinically evident thrombosis. In conclusion, this method distinguishes HITT from HIT and may be clinically useful in the detection of HITT, allowing early intervention for preventing catastrophic thrombosis.

Pyrithione, a zinc ionophore, inhibits NF-kappaB activation

Pyrrolidine dithiocarbamate (PDTC) suppresses NF-kappaB activity and exhibits cytotoxic effects in bovine cerebral endothelial cells (BCECs), and we have previously reported that these PDTC effects were accompanied by an increase in intracellular zinc levels. To further explore the role of zinc in the modulation of NF-kappaB activation, we studied the effect of pyrithione, a zinc ionophore, on NF-kappaB activation in BCECs. Pyrithione inhibited NF-kappaB activity in a time- and dose-dependent manner. Ca-EDTA, but not Zn-EDTA, prevented pyrithione inhibition of NF-kappaB activity. Pyrithione increased the intracellular zinc level within 15 min. This effect was also abolished by Ca-EDTA, but not by Zn-EDTA. The potency of pyrithione on NF-kappaB inhibition and zinc influx was approximately one order of magnitude more potent than PDTC. These findings establish the regulatory role of intracellular zinc levels on NF-kappaB activity in BCECs.

Zinc is required in pyrrolidine dithiocarbamate inhibition of NF-kappaB activation

Pyrrolidine dithiocarbamate (PDTC) is a potent inhibitor of nuclear factor kappa B (NF-kappaB) activation. PDTC inhibited basal NF-kappaB activity of endothelial cells. PDTC, however, failed to inhibit basal NF-kappaB activity after withdrawal of serum in the media, and the inhibitory effect of PDTC could be restored by addition of zinc. When various preparations of metal ion-EDTA were tested with PDTC in serum-containing media, only Zn-EDTA failed to block the inhibitory effect of PDTC. The dependence on zinc was also noted in PDTC inhibition of NF-kappaB stimulated by TNF alpha. These facts suggest that zinc is required for PDTC inhibition of NF-kappaB activation.

Tumor necrosis factor-alpha and phorbol 12-myristate 13-acetate differentially modulate cytotoxic effect of nitric oxide generated by serum deprivation in neuronal PC12 cells

Nitric oxide (NO) is a signaling molecule that mediates several physiological processes in a range of cell and tissue types. Here we investigated the effect of serum deprivation in the absence or presence of phorbol 12-myristate 1 3-acetate (PMA) or tumor necrosis factor-alpha (TNFalpha) on cell viability, NO formation, inducible NO synthase (iNOS) induction, and activation of mitogen-activated protein kinase in neuronal PC12 cells. Within 24 h of serum deprivation, apoptosis occurred in up to 65-70% of the cells, and significant levels of NO were generated. When PMA was added in serum-free medium, NO formation and cell death were decreased. In contrast, addition of TNFalpha in serum-free medium increased the levels of NO formation and apoptosis compared with those in serum-deprived cells. We have demonstrated that differential generation of NO levels by PMA or TNFalpha under conditions of serum deprivation is mediated by the same pattern of iNOS induction. NO formation via iNOS induction resulted in the activation of c-Jun N-terminal kinase (JNK) but not extracellular signal-regulated kinase. From this study it is suggested that the differential formation of cytotoxic NO by serum deprivation plus PMA or TNFalpha is primarily mediated by the induction of iNOS enzymes in neuronal PC12 cells and that its action is mediated by the activation of JNK.

Pyrrolidine dithiocarbamate induces bovine cerebral endothelial cell death by increasing the intracellular zinc level

The antioxidant and metal-chelating effects of pyrrolidine dithiocarbamate (PDTC) have been extensively studied. PDTC prevents cell death induced by various insults. However, PDTC itself may cause cell death in selected experimental paradigms. PDTC induced bovine cerebral endothelial cell death. However, in serum-depleted medium, PDTC did not affect the cell viability, suggesting that certain factors in serum may mediate the cytotoxic effect of PDTC. The metal chelators bathocuproine disulfonic acid, o-phenanthroline, bathophenanthroline disulfonic acid, and N,N,N',N'-tetrakis(2-pyridyl-methyl)ethylenediamine (TPEN) prevented the cell death induced by PDTC. In a serum-deprived condition, addition of exogenous metals, copper or zinc, restored the cytotoxic effect of PDTC. These data indicate that metals such as copper or zinc in serum may mediate the cytotoxic effect of PDTC. The potency of zinc for PDTC-induced endothelial cell death was greater than that of copper. Zn-EDTA did not block PDTC-induced cell death, whereas Ca-EDTA and Cu-EDTA were able to prevent this PDTC effect. PDTC increased the intracellular fluorescence of the zinc probe dye N-(6-methoxy-8-quinolyl)-p-toluenesulfonamide, which was quenched by TPEN or various EDTA preparations but not by Zn-EDTA. Results suggest that an increase in intracellular zinc concentration is required in PDTC-induced cerebral endothelial cell death.

Fas ligand and Fas are expressed constitutively in human astrocytes and the expression increases with IL-1, IL-6, TNF-alpha, or IFN-gamma

Fas ligand (FasL) and Fas are mediators of apoptosis, which are implicated in the peripheral deletion of autoimmune cells, activation-induced T cell death, and cytotoxicity mediated by CD8+ T cells. Fas is also believed to be involved in several central nervous system diseases, but until now, the effector cells expressing FasL in the brain have not been identified. We investigated the expression levels of Fas and FasL with the stimulation of cytokines and the possible effector cells targeting Fas-bearing cells. Our data demonstrated that: 1) FasL is expressed constitutively on astrocytes taken from a fetus or an adult and that its expression increases when these cells are treated with IL-1, IL-6, or TNF-alpha in which the pretreatment of IFN-gamma triggers astrocytes to express more FasL; 2) astrocytes induce apoptosis in MOLT-4 cells through FasL; 3) Fas is also expressed constitutively and is up-regulated by IL-1, IL-6, or TNF-alpha in which the pretreatment of IFN-gamma triggers astrocytes to express more Fas; 4) apoptosis occurs when fetal astrocytes are treated with agonistic anti-Fas IgM Ab after culture with IFN-gamma and TNF-alpha; and 5) TNF-related apoptosis inducing ligand is up-regulated in fetal astrocytes with stimuli of IL-1 or TNF-alpha. These findings suggest a possible role of astrocytes in the induction of apoptosis in central nervous system diseases.

Anti-CD36 autoantibodies in thrombotic thrombocytopenic purpura and other thrombotic disorders: identification of an 85 kD form of CD36 as a target antigen

The presence of anti-CD36 antibodies in plasma of patients with thrombotic thrombocytopenic purpura (TTP), idiopathic thrombocytopenic purpura (ITP), and heparin-induced thrombocytopenia without/with thrombosis (HIT/HITT) has been examined by immunoblots, and a monoclonal antibody capture assay, the platelet-associated IgG characterization assay (PAICA). Results with PAICA showed that 73% (8/11) of patients with TTP were positive, and 71% (10/14) by immunoblots. With ITP, 20% (6/30) were positive by PAICA and 19% (3/16) by immunoblots; HIT, 30% (3/10) were positive by PAICA and 60% (6/10) by immunoblot; HITT, 50% (2/4) by PAICA and 100% (4/4) by immunoblot. Purification of CD36 by fast protein liquid chromatography (FPLC) from Triton X-100 extracts of normal platelet membranes resulted in the isolation of two different forms: the classic 88 kD form, and a second, lighter 85 kD form. Our data indicated that the patients' plasma autoantibodies reacted strongly with the 85 kD form. Conventional monoclonal and polyclonal antisera produced to the 88 kD form reacted strongly with the 88 kD form but weakly with the 85 kD form. These results confirm the possible importance of anti-CD36 antibodies in the pathophysiology of TTP and other thrombocytopenias and demonstrate the presence of a previously unrecognized target antigen for these antibodies.

Inhibitory effect of ginsenoside on the mediator release in the guinea pig lung mast cells activated by specific antigen-antibody reactions

We reported that some components of ginsenosides decreased mediator release which was evoked by the activation of mast cells caused by specific antigen-antibody reactions. This study aimed to assess the effects of ginsenoside, Rb1, which belongs to the protopanaxadiol, on the mechanism of mediator release during mast cell activation. Pretreatment of Rb1 (100 microg) significantly decreased histamine and leukotriene in a dose-dependent manner during mast cell activation. The PLD activity during mast cell activation decreased in the pretreatment of Rb1 (300 microg). The amount of DAG produced by PLC activity decreased because of Rb1 pretreatment. The amount of mass DAG decreased due to Rb1 pretreatment during mast cell activation. Rb1 (300 microg) pretreatment strongly inhibited the incorporation of the [3H]methyl moiety into phospholipids. The data suggest that Rb1, purified from Korean Red Ginseng Radix, inhibits an increase of DAG production during mast cell activation caused by antigen-antibody reactions, which is mediated via phosphatidylcholine-PLD and phosphatidylinositol-PLC systems. This is then followed by the inhibition of histamine releases. Furthermore, Rb1 reduces the phosphatidylcholine production by inhibiting the methyl-transferase I and II, and the reduction of phosphatidylcholine production inhibits leukotriene release.

Expression of immediate early gene cyr61 during the differentiation of immortalized embryonic hippocampal neuronal cells

Growth factor-mediated signal transduction is a process that is of fundamental importance in understanding cellular growth and differentiation. In order to elucidate the signaling pathways leading to neuronal differentiation, we have tried to identify intermediates that are selectively induced in the differentiation of immortalized neuronal hippocampal cell line H19-7. In the present study we found that immediate early gene cyr61 is expressed in a rapid and transient manner by bFGF during the differentiation of H19-7 cells. To clarify the signal transduction pathway for the induction of cyr61 by bFGF, we checked whether Raf-1 and mitogen-activated protein kinase (MAPK) is activated during the induction of cyr61. It is identified that cyr61 is induced by bFGF via at least two signaling pathways; MAPK-dependent as well as MAPK-independent signaling pathways. This study suggested that cyr61 is likely to play an important role in neuronal differentiation process.

Platelet activation in Alzheimer disease

BACKGROUND

In light of recent reports of diminished platelet serotonin concentration and increased plasma serotonin levels in patients with Alzheimer disease (AD), we hypothesized that a state of heightened platelet activation might be present in AD.

OBJECTIVE

To compare baseline activation of unstimulated platelets in patients with AD with that in control subjects.

PATIENTS AND METHODS

Flow cytometry was used to measure platelet activation in 91 patients with probable AD and 40 age-matched control subjects. Groups were compared for percentage of circulating platelet aggregates, expression of CD62p, formation of leukocyte-platelet complexes, and presence of circulating platelet microparticles, controlling for effects of demographic, clinical, physiological, and logistical factors.

RESULTS

Multiple analysis of covariance on ranked data revealed a 39.5% increase in percentage of platelet aggregates (P=.0001), a 59.3% increase in expression of CD62p (P=.001), and a 53.3% increase in leukocyte-platelet complexes (P=.0001) in the group with AD but no differences in the number of platelet microparticles, overall platelet count, plasma fibrinogen level, or plasma platelet factor 3. Activation was weakly correlated with sex, but was independent of age, severity of disease, duration of disease, depression, agitation, and family history of dementia.

CONCLUSIONS

Platelets of patients with AD exhibit greater unstimulated activation than those of controls. Potential causes of such activation include possible stimulation of platelets by damaged cerebral endothelial cells or platelet activation induced by membrane abnormalities previously reported to be present in platelets of patients with AD. In light of recent evidence that platelets are the principal source of both amyloid precursor protein and beta-amyloid peptide in human blood, it is possible that AD platelet activation may reflect or even contribute to the pathogenesis of the disease.

Thrombotic thrombocytopenic purpura plasma enhances platelet-leucocyte interaction in vitro

In thrombotic thrombocytopenic purpura (TTP), intravascular platelet aggregation and formation of platelet-rich thrombi impair the microcirculation. TTP plasma has been shown to induce aggregation of normal platelets in vitro. The present study investigates the formation of activated platelet aggregates (aPAg) induced by TTP plasma, with particular attention to their binding to leucocytes (LPAg). Results were compared with the effects of plasmas from normal controls (CTL) and from patients with immune thrombocytopenic purpura (ITP) or thrombosis (THR). Following addition of test plasma to normal whole blood (WB), aPAg and LPAg were assayed by flow cytometry using mAbs against CD41 (platelet marker), CD62p (platelet activation marker) and CD45 (pan-leucocyte marker), Compared to control plasma, TTP plasma was more potent than ITP or THR plasma in increasing aPAg: only TTP plasma significantly promoted leucocyte binding to give increased LPAg. Prior removal of neutrophils (PMN) from WB by beads coated with anti-CD15 mAb largely prevented formation of aPAg and LPAg. However, TTP plasma added to normal platelet-rich plasma significantly increased aPAg, which suggested possible hindrance of aPAg formation by erythrocytes and other leucocytes in PMN-depleted blood. We concluded that TTP plasma was most potent in the induction of aPAg and unique in promoting LPAg formation in WB. Neutrophils, and not other leucocytes, appear to be essential for LPAg formation. Enhanced PMN-platelet interaction in the microcirculation may facilitate platelet adhesion to vessel walls and promote the formation of platelet-rich microthrombi in TTP.

Platelet aggregates as markers of platelet activation: characterization of flow cytometric method suitable for clinical applications

The present paper describes a flow cytometric method for assay of platelet aggregates (PAg) in blood. This method combines and simplifies previously reported techniques, simultaneously enumerating PAg formed upon platelet activation, their expression of activation marker CD62P (P-selectin), and their content of bound leukocytes (LPAg). The sensitivity of this method to low levels of agonists (ADP, collagen) is compared to conventional aggregometry and some features of platelet-leukocyte interaction are explored. The results were: (1) ADP or collagen induced a dose-dependent increase in PAg number and corresponding decline in free platelets. The ED50 for ADP (0.15 microM) and for collagen (0.2 microg/mL) was about 1/20 the ED50 found by aggregometry, indicating 20-fold greater sensitivity. (2) At higher concentrations, the fraction of PAg with bound leukocytes (LPAg) increased to 60-70%. This rise correlated with PAg size and CD62P expression, but not with the number of PAg formed. (3) The response of whole blood (WBD) to agonists was qualitatively different from that of platelet-rich plasma (PRP): in WBD the population of CD62P+ PAg was much higher than in PRP and the population of CD62P+ free platelets was much lower. This implies that leukocytes rapidly recruit activated platelets. (4) Desmopressin (DDAVP) at 5 nmol/L induced a significant rise in activated (CD62P+) PAg and platelets, even though no effect of DDAVP could be detected by conventional aggregometry; this further confirms that DDAVP acts directly on platelets. (5) Plasma samples from TTP patients induced a rise in PAg when added to normal PRP, though little or no effect could be detected by aggregometry. In summary, the flow cytometric method described here appears useful for detecting low levels of platelet activation and provides information on platelet leukocyte interaction, potentially important in identifying and differentiating thrombogenic states. Since it is rapid and economical, it is well suited for clinical implementation.

Cutaneous reactions to recombinant human interferon beta-1b: the clinical and histologic spectrum

BACKGROUND

Recombinant human interferon beta-1b has been recently approved for the treatment of multiple sclerosis. A significant proportion of patients treated with this medication experienced cutaneous reactions.

OBJECTIVE

We describe the clinical and histologic features of cutaneous reactions to recombinant human interferon beta-1b.

METHODS

Consecutive patients with cutaneous reactions to recombinant interferon beta-1b were evaluated clinically and by biopsy.

RESULTS

Clinical lesions varied from subtle uninflamed sclerotic dermal plaques to erythematous plaques to cutaneous ulcers at injection sites. The nonsclerotic lesions were frequently painful. The firm plaques showed fibrosis histologically, whereas nonsclerotic inflammatory lesions demonstrated a consistent pattern of vascular thrombosis. Hematologic evaluation demonstrated platelet activation in most patients with inflammatory lesions, a feature also noted before interferon treatment in some patients.

CONCLUSION

Therapy with recombinant interferon beta-1b is associated with a spectrum of cutaneous reactions and vascular thrombosis.

Platelet microparticles and calcium homeostasis in acute coronary ischemias

Elevation of free cytoplasmic calcium is the common pathway of platelet activation, leading to shape change, shedding of platelet microparticles (PMP), aggregation, and secretion of internal granules, including expression of CD62p on the surface. Platelet activation is well documented in unstable angina (UA) and acute myocardial infarction (MI). We investigated the following markers of platelet activation in 55 patients undergoing coronary angiography for suspected CAD: free cytoplasmic calcium, [Ca2+]cyt, PMP, CD62p expression, and platelet/leukocyte (P/L) interaction. [Ca2+]cyt was measured by Fluo-3 and the other measurements were by flow cytometry. Patients were classified into three groups: unstable angina (UA, n = 11), recent myocardial infarction (MI, n = 11), and patient controls (CTL, n = 33). Blood was drawn before infusion of heparin through femoral lines at the time of catheterizaton for assays. (

RESULTS

(1) PMP values were significantly higher in both UA and MI than in CTL, P < 0.05. There was no difference between UA and MI. (2) P/L interaction was significantly elevated only in UA, P < 0.05. (3) CD62p expression on free platelets did not differ significantly between any of the three groups. (4) The resting [Ca2+]cyt, thrombin-induced Ca2+ influx, and release of Ca2+ from internal stores were all significantly higher in platelets from the combined patient group (UA + MI) than in the patient control group, P < 0.001

CONCLUSIONS

Results on calcium hemostasis and PMP were significantly different in patients with acute coronary syndromes than those with stable angina or no coronary ischemia; this may reflect underlying pathophysiology of acute coronary ischemia. P/L interaction was higher only in the UA group, suggesting a role of leukocytes in UA.

Danazol for paroxysmal nocturnal hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare clonal stem-cell disorder in which blood cells lack complement inhibiting membrane proteins, and become susceptible to complement-mediated injury, leading to chronic intravascular hemolysis and pancytopenia. Glucocorticoids have been a mainstay of therapy. For patients refractory to glucocorticoids and requiring blood transfusions, an alternative therapy is needed. We studied danazol therapy in 5 patients refractory to other treatments. Four of the 5 benefited, showing rise in hematocrit and eventual cessation of transfusion requirements. Remissions lasted > or =2 years in 3 and 10 years in 1 patient. Danazol was well-tolerated without serious side effects. Danazol appears to be a good alternative treatment in PNH.

Activated platelet aggregates in thrombotic thromboctyopenic purpura: decrease with plasma infusions and normalization in remission

Circulating activated platelet aggregates (aPA) were assayed by flow cytometry employing mAb alpha-CD62p in eight patients with thrombotic thrombocytopenic purpura (TTP). Elevation of aPA was observed in all patients in active stages of TTP; aPA normalized in remission. Plasma infusions with plasmapheresis decreased aPA in responding patients. The rise and fall of aPA preceded relapses and improvements, respectively. These changes were seen prior to the traditional indicators, LDH, haematocrit, and platelet count. Incubation of plasma from TTP patients with normal whole blood induced formation of aPA; this effect was significantly greater than that of plasmas from ITP patient controls (P < 0.01), suggesting the presence of an aPA-promoting factor in TTP plasma. Parallel experiments using a platelet aggregometer failed to detect effect of TTP plasma on normal blood. In summary, aPA appear to be a marker of disease activity, rising with relapse, falling with plasma therapy, and normalizing in remission. The flow cytometric assay of aPA is more sensitive than aggregometry in detecting the putative aPA-promoting factor in TTP.

Fatty acid unsaturation increases expression and capping of murine lymphocyte CD44 and CD45

We studied the effect of incubating murine lymphocytes with cis-unsaturated fatty acids on expression and capping of CD44 and CD45. Lymphocytes were incubated with stearic (18:0) or oleic (18:1 omega-9) acid bound to bovine serum albumin (BSA). After incubation with rat anti-CD44 or anti-CD45 monoclonal antibodies and then with fluorescent-labeled anti-rat antibody, mean fluorescence intensity (FI) was measured by using flow cytometry. Capping was measured after warning and fixation in paraformaldehyde. Steady-state fluorescence anisotropy (rs) was measured after the cells had been incubated with trimethylammoniumdiphenylhexatriene. Incubation with oleic acid, but not stearic acid or BSA alone, was associated with an increase in FI of CD44. Expression of CD45, however, was increased by both stearic and oleic acids to the same degree over BSA controls. CD44 and CD45 capping were both increased by incubation with oleic acid. Rs was decreased in cells incubated with oleic acid, suggesting an increase in membrane fluidity. We conclude that incubation with oleic acid increases expression of CD44 and increases capping of both CD44 and CD45. These findings were confirmed in feeding experiments, in which rs was reduced and CD44 capping increased by polyunsaturated fatty acid diets.

Involvement of CD44 and the cytoskeletal linker protein ankyrin in human neutrophil bacterial phagocytosis

The leukocyte CD44 and CD45 cell surface receptors are associated via the linker proteins ankyrin and fodrin with the cytoskeleton, which itself is important in immune cell functions such as adherence, chemotaxis, and phagocytosis. The effects of rat antihuman CD44 and CD45 monoclonal antibodies on phagocytosis of fluoresceinated heat-killed Staphylococcus aureus 502A by normal human neutrophils (PMNs) during 2 hr incubation in RPMI-1640 was studied via flow cytometry and confocal microscopy. Flow cytometry was performed using an excitation wavelength of 488 nm, fluorescence being measured at 515-560 nm on 50,000 PMNs per sample. Confocal microscopy was performed on samples after further incubation with rhodamine-conjugated antiankyrin. Anti-CD44 resulted in an increase of 27-31% compared to control (P = 0.004) in the proportion of PMNs fluorescing, an increase of 17-24% (P = 0.001) in mean intracellular fluorescence per PMN, and an increase in total PMN fluorescence of 50-58% compared to control (P < 0.001). In contrast, anti-CD45 had little effect on phagocytosis. Colchicine (a microtubule-disrupting agent) enhanced, whereas cytochalasin-D (a microfilament inhibitor) inhibited bacterial phagocytosis; cytochalasin-D completely abrogated the effect of anti-CD44 on this PMN function. Hyaluronic acid augmented phagocytosis by an increment similar to that observed with anti-CD44. Two-color flow cytometry and confocal microscopy demonstrated that ankyrin always colocalized with ingested fluorescein isothiocyanate (FITC)-labeled bacteria. These data strongly suggest that CD44 is involved in bacterial phagocytosis, provide further evidence of CD44 receptor linkage to cytoskeletal elements in human leukocytes, and suggest that ankyrin has a significant role in the transport of phagosomes.

Supplemental L-arginine HCl augments bacterial phagocytosis in human polymorphonuclear leukocytes

That L-arginine (L-Arg) augments the host response to acute bacterial sepsis suggests that this amino acid intervenes early in the immune response, perhaps via the nitric oxide synthetase (NOS) pathway. The effect of L-Arg supplementation on in vitro phagocytosis of fluorescein-labeled, heat-killed Staphylococcus aureus by peripheral blood neutrophils (PMNs) from 12 normal human volunteers was studied. Separated PMNs were incubated for 2 h with labeled bacteria, with and without supplemental L-Arg, D-arginine, glycine, and/or the NOS inhibitors L-canavanine, aminoguanidine, or L-NG-nitroarginine methyl ester. PMNs were fixed and extracellular fluorescence quenched with crystal violet. By flow cytometry and confocal microscopy, L-Arg supplementation was shown to result in a highly significant increase in PMN bacterial phagocytosis, the maximal effect being seen with L-Arg 380 microM and falling off with higher concentrations. This augmentation was completely abrogated by NOS inhibitors in molar excess, but inhibitors alone did not suppress phagocytosis below that of unsupplemented controls. Neither D-arginine nor glycine affected phagocytosis; the L-Arg effect was stereospecific and not related to utilization of L-Arg as an energy source. L-Arg supplementation significantly enhances bacterial phagocytosis in human neutrophils, perhaps by effects on cytoskeletal phenomena, and this appears to be mediated through NOS activity. Phagocytosis by nonspecific immune cells which intervene early in the response to sepsis is critically important, and beneficial effects of L-Arg on the clinical course of sepsis may be due at least in part to augmentation of phagocyte function.

Danazol relieves refractory pruritus associated with myeloproliferative disorders and other diseases

Severe pruritus is frequently associated with myeloproliferative and other systemic illnesses, and often fails to respond to conventional measures. We used danazol (Danocrine), a synthetic attenuated androgen, in the treatment of severe pruritus refractory to conventional therapy. Eight patients had myeloproliferative disorders (MPD), seven had autoimmune disorders, and seven had skin diseases. Danazol at 400-800 mg/day was administered, and previous medications were tapered off. When itching was controlled with danazol alone, the dosage was reduced or discontinued, and resumed if itching recurred. Clinical responses were graded, and side effects were monitored. Overall, in 12 of 22 patients refractory to other measures, itching was controlled with danazol alone. In 10 patients itching returned when danazol was discontinued or dosage was continued for up to 5 years in responders. No serious side effects were observed. Our experience indicates that danazol is a good alternative for patients with severe pruritus associated with myeloproliferative and other systemic disorders.

Platelet factor 3 in plasma fractions: its relation to microparticle size and thromboses

Platelet factor 3 (PF3) was assayed by Russell's viper venom (RVV) in three plasma fractions, platelet-rich plasma (PRP), platelet poor plasma (PPP), and 0.1 microns particle-filtered plasma (PFP), in 42 healthy controls, 34 patients with recent cerebrovascular accidents (CVA) and 28 with recent ischemic events from coronary artery disease (CAD). Platelet microparticles (PMP) were assayed in PPP by flow cytometry. Relative to controls, the RVV clotting times were shortened in all three plasma fractions in both patient groups, p < 0.001. PMP were also elevated in both patient groups, p < 0.001. Linear regression analysis showed that the RVV times of PPP are inversely correlated with PMP, p < 0.005, in patient groups but not in controls. There was no correlation of RVV time with PT, APTT or FIB. After converting RVV times to units of PF3 activity, it could be shown that only about 1/4 of the total PF3 activity was contributed by platelets. The major contribution to the PF3 activity in controls was from microparticles < 0.1 microns but in patients was due mainly to microparticles > 0.1 microns. The RVV time was superior to routine coagulation tests in discriminating thrombotic patients from healthy controls.