In Vitro and In Vivo Antiglycation Effects of Connarus ruber Extract.

Accumulation of advanced glycation end products (AGEs) of the Maillard reaction has been implicated in the pathogenesis of diabetes and its complications. Connarus ruber has been used as a folk remedy for several diseases, including diabetes; however, its underlying mechanism has not yet been investigated. This study investigated the effects of C. ruber extract against glycation on collagen-linked AGEs in vitro and streptozotocin-induced diabetic rats (STZ-DM rats) in vivo. The antiglycation activities of C. ruber extract and aminoguanidine (AG) were examined using a collagen glycation assay kit. Nonfluorescent AGE, Nε-carboxymethyl lysine (CML), Nω-carboxymethyl arginine, and Nε-carboxyethyl lysine levels were measured via electrospray ionization-liquid chromatography-tandem mass spectrometry. The effect of the extract on the cytotoxicity of methylglyoxal (MG), a precursor of AGEs, was examined in HL60 cells. STZ-DM rats were treated with the extract for 4 wk, and the effect was assessed using biochemical markers in the serum and CML-positive cells in renal tissues. C. ruber extract dose-dependently inhibited the glycation of collagen and formation of nonfluorescent AGEs, which was comparable to AG, and it significantly attenuated MG-induced cytotoxicity in HL60 cells. Furthermore, the glycated albumin levels in STZ-DM rats decreased, the increase in serum lipid levels was reversed, and immunohistochemistry demonstrated that CML deposition in the glomerulus of STZ-DM rats significantly decreased. Although further studies are needed, C. ruber could be a potential therapeutic for preventing and progressing many pathological conditions, including diabetes.

Quantitative analysis of hemin-induced neutrophil extracellular trap formation and effects of hydrogen peroxide on this phenomenon.

Formation of neutrophil extracellular traps (NETs) can perpetuate sterile inflammation; thus, it is important to clarify their pathophysiological characteristics. Free heme, derived via hemolysis, is a major contributor to organ damage, and reportedly induces neutrophil activation as well as reactive oxygen species (ROS) production and NET formation. For this study, we examined hemin (Fe3+ -protoporphyrin IX)-induced NET formation quantitatively in vitro as well as the effects of oxidative stress. NETs formed in vitro from cultured neutrophils were quantitatively detected by using nuclease treatment and Sytox Green, a nucleic acid stain. Hemin-induced NET production was found to be in a dose-dependent manner, NADPH oxidase-dependent and toll-like receptor (TLR)-4 independent. Additionally, the iron molecule in the porphyrin ring was considered essential for the formation of NETs. In the presence of low concentrations of hydrogen peroxide, low concentrations of hemin-induced NETs were enhanced, unlike those of phorbol myristate acetate (PMA)-induced NETs. Quantitative analysis of NET formation may prove to be a useful tool for investigating NET physiology, and hemin could function as a possible therapeutic target for hemolysis-related events.

Iron-chelating agent, deferasirox, inhibits neutrophil activation and extracellular trap formation.

Iron-chelating agents, which are frequently prescribed to transfusion-dependent patients, have various useful biological effects in addition to chelation. Reactive oxygen species (ROS) produced by neutrophils can cause pulmonary endothelial cell damage, which can lead to acute lung injury (ALI). We previously reported that deferasirox (DFS), an iron-chelating agent, inhibits phorbol myristate acetate (PMA) or formyl-methionyl-leucyl-phenylalanine (fMLP)-induced ROS production in neutrophils, in vitro. Here, we investigate whether DFS inhibits vacuolization in neutrophils and neutrophil extracellular trap (NET) formation. Human neutrophils were incubated with DFS and stimulated with PMA or fMLP. Human neutrophils were separated from heparinized peripheral blood using density gradient centrifugation, and subsequently incubated with DFS. After 10 minutes, neutrophils were stimulated by PMA or fMLP. Vacuole formation was observed by electron microscopy. For observing NET formations using microscopes, immunohistological analyses using citrullinated histone H3 and myeloperoxidase antibodies, and SYTOX Green (an impermeable DNA detection dye) staining, were conducted. NET formation was measured as the quantity of double-stranded DNA (dsDNA), using the AccuBlue Broad Range dsDNA Quantitation Kit. DFS (50 µmol/L) inhibited vacuole formation in the cytoplasm and NET formation. Additionally, 5-100 µmol/L concentration of DFS inhibited the release of dsDNA in a dose-independent manner. We demonstrate that DFS inhibits not only ROS production but also vacuolization and NET formation in neutrophils. These results suggest the possibility of protective effects of DFS against NET-related adverse effects, including ALI and thrombosis.

Bortezomib Causes ER Stress-related Death of Acute Promyelocytic Leukemia Cells Through Excessive Accumulation of PML-RARA.

BACKGROUND/AIM: The success of proteasome inhibitors in therapy of multiple myeloma has led to their use for other malignancies. For the proteasome inhibitor bortezomib, combination therapies with histone deacetylase inhibitors, which up-regulate ubiquitin-proteasome system (UPS)-related enzymes, produce a beneficial effect. However, the mechanisms underlying the effect of bortezomib are not completely understood. We hypothesized that bortezomib causes excessive accumulation of aberrant proteins, which augments endoplasmic reticulum (ER) stress, leading to death of malignant cells. MATERIALS AND METHODS: The NB4 cell line established from a patient with acute promyelocytic leukemia (APL) expressing the promyelocytic leukemia/retinoic acid receptor alpha (PML-RARA) fusion protein was used to assess changes in cell viability and apoptosis caused by bortezomib, as well as alterations in PML-RARA and UPS-related enzymes via western blotting and immunoprecipitation assays. RESULTS: Bortezomib time- and dose-dependently reduced cell viability and induced apoptosis. Bortezomib significantly increased the abundance of ubiquitinated-PML-RARA (Ub-PML-RARA), ubiquitin-conjugating human enzyme 8 (UbcH8), and Ub-UbcH8, indicating that UbcH8 is the E2 ubiquitin-conjugating enzyme for PML-RARA. Moreover, UbcH8 abundance was dose-dependently increased in the culture supernatant of bortezomib-treated cells. CONCLUSION: UbcH8 may have a utility as a biomarker of treatment response to bortezomib in patients with APL. Furthermore, bortezomib impairs the UPS that controls normal protein homeostasis by causing excessive accumulation of PML-RARA augmenting ER stress and leading to APL cell death. The study provides a rationale for incorporating proteasome inhibitors in the treatment of diseases expressing aberrant proteins. Furthermore, monitoring of UPS-related enzymes might have use in predicting the treatment response to proteasome inhibitors and in assessing their therapeutic effects.

Heme-related molecules induce rapid production of neutrophil extracellular traps.

BACKGROUND: Pulmonary endothelial cell damages caused by neutrophil overactivation could result in acute lung injuries including transfusion-related acute lung injury (TRALI). We previously reported that heme-related molecules derived from hemolysis induced the production of reactive oxygen species from neutrophils. Recently, neutrophil extracellular traps (NETs) have been demonstrated to associate with the onset of TRALI. STUDY DESIGN AND METHODS: In this study, neutrophils' morphologic changes induced by the heme-related molecule hemin were confirmed to be NETs via confocal laser scanning microscopy and electron microscopy (EM). Additionally, concentrations of hemin in red blood cell (RBC) components were measured via enzyme-linked immunosorbent assay and possible contribution of these molecules to the onset of TRALI was discussed. RESULTS: SYTOX green staining observation via confocal laser scanning microscopy revealed that neutrophil morphology changed rapidly upon addition of hemin. The nuclei began to be enlarged and become segmented after 5 minutes, and NET-like structures were released from neutrophils after 15 minutes. In EM observation, NET-like structures appeared after 10 minutes and the nucleoplasm was partially separated from the nuclear membrane, which were consistent with the features of NET formation. These structures stained positively for both myeloperoxidase and histone H3 antibodies. CONCLUSION: Thus, our results suggest that hemin induced NETs in 15 minutes, a quicker reaction than NET induction by phorbol myristate acetate requiring 3 hours. Moreover, since RBC components, especially those with long-term storage, contained sufficient hemin concentration to induce NETs, special attention to hemolysis of stored RBC components is important.

A case of acute promyelocytic leukemia with morphologic multilineage dysplastic changes.

Although reports of typical acute promyelocytic leukemia (APL) cases rarely mention dysplastic changes, this report concerns a rare case of APL with tri-lineage dysplastic changes resembling the characteristic features of myelodysplastic syndrome (MDS). The patient, a 77-year-old Japanese male, was diagnosed as having pancytopenia with hematologic morphological abnormalities comprising micro - megakaryocytes, neutrophils with hypo-granulation and negative peroxidase activity, and erythroblasts containing nuclei with abnormalities such as karyorrhexis. Although there is one report of a case of transformation of de novo MDS into APL and several reports of cases of therapy-related MDS transformed into APL, our patient had no history of cytopenia or of either chemo or radiation therapy. Our case can thus be considered to constitute a rare case of APL with dysplastic morphology.

Deferasirox reduces oxidative stress in patients with transfusion dependency.

BACKGROUND: Iron chelation therapy is useful against the over-accumulation of iron and is expected to reduce oxidative stress resulting from the Fenton reaction and Haber-Weiss reaction. We monitored oxidative status and serum ferritin levels after in vivo administration of deferasirox (DFS) and studied the in vitro effects of iron chelators on neutrophil function. METHODS: Nine patients suffering from transfusion dependency were recruited for this study, and derivatives of reactive oxygen metabolite (dROM) tests to detect serum hydroperoxide levels were evaluated in addition to serum ferritin levels. Human neutrophil reactive oxygen species (ROS) production was determined with flow cytometry. RESULTS: Ferritin levels decreased after DFS treatment (P = 0.068), and a significant reduction in dROM levels was measured (P = 0.031). Fifty microM DFS significantly inhibited ROS production induced by fMLP in vitro (P < 0.0001), and tended to inhibit that induced by PMA. On the other hand, deferioxamine failed to inhibit ROS production even at high concentrations. CONCLUSIONS: In vivo administration of DFS resulted in the reduction of oxidative stress, and this effect was considered to depend not only on a reduction in iron storage but also on the ability of DFS to inhibit neutrophil ROS production in vitro at clinically relevant plasma levels. Further studies are needed to examine the effects of iron chelators.

Morphological and flow-cytometric analysis of haemin-induced human neutrophil activation: implications for transfusion-related acute lung injury.

BACKGROUND: Transfusion-related acute lung injury (TRALI) is associated with vascular endothelial cell injury following neutrophil activation. Recently, it has been suggested that haem-related molecules induce activation of neutrophils and that erythrocyte-derived substances contained in blood preparations are involved in TRALI. We observed the morphological effects and reactive oxygen species (ROS) production of haem-related molecules and investigated the effects of signal transduction inhibitors on haem-induced neutrophil activation. MATERIALS AND METHODS: The polymorphonuclear cell fraction was isolated and stimulated using a control stimulant, PMA or fMLP, or by haem-related molecules, haemin, ferric citrate, or protoporphyrin IX. After stimulation, neutrophil was analysed using electron microscopy, a flowcytometer (FCM) and confocal laser scanning microscope to determine the fluorescent intensity of aminophenyl fluorescein (to detect ROS). RESULTS: In FCM analysis, haemin and protoporphyrin IX, both of which have a porphyrin ring, induced ROS production in neutrophils. Ferric citrate, which has no porphyrin ring, did not induce neutrophil activation. Haemin alone induced ROS production at relatively high concentrations, whereas low-level fMLP acted as an agonist in the presence of low concentrations of haemin. Haem-related molecules induced ROS production in neutrophil granules through signal transduction in a way similar to PMA. However, in electron microscopy studies, haemin stimulated neutrophils showed minute process at their surface and did not show the vacuolation observable following stimulation with PMA or fMLP. DISCUSSION: We suggest that low concentrations of haem-related molecules with porphyrin rings in the presence of other stimulating agent are important for ROS production and possibly the onset of TRALI. The ROS production induced by these molecules is dependent on a signal transduction pathway in a way similar to PMA.

FLT3/ITD associated with an immature immunophenotype in PML-RARα leukemia.

Acute promyelocytic leukemia (APL) is characterized by the specific PML-RARα fusion gene resulting from translocation t(15;17) (q22;q12). Internal tandem duplication (ITD) of the FLT3 gene has been observed in approximately 35% of APLs, and large-scale studies have identified the presence of ITD as an adverse prognostic factor for acute myeloblastic leukemia (AML) patients. Aberrant expressions of surface antigens, such as CD2, CD34, and CD56, have been found in APL, but the implications of this are not well understood. We investigated the incidence of the FLT3/ITD mutation and FLT3/D835 (I836) point mutation in 25 APL patients. Incidence ratios of FLT3/ITD, D835 (I836), and both FLT3/ITD and D835 (I836) were 36%, 36% and 8%, respectively. FLT3/ITD(+) cases showed a predominance of the bcr3 isoform (P=0.008) and M3v morphology (P<0.001). We found that all FLT3/ITD(+) cases expressed CD2 (9 of 9) more frequently than that of FLT3/ITD(-) (1 of 16) (P<0.001), while only one of the CD2(+) cases (1 of 10, 10%) did not harbor FLT3/ITD, and all CD2(+)CD34(+) cases (5 of 5, 100%) harbored FLT3/ITD. In addition, quantitative polymerase chain reaction analysis showed that FLT3 mRNA was more abundantly expressed in FLT3/ITD(+) than that in FLT3/ITD(-) (P=0.025), while there was no difference between D835(I836) (+) and D835(I836)(-) with regards to aberrant surface-antigen expression, expression levels of FLT3 mRNA, M3v morphology, and the bcr3 isoform of PML-RARα mRNA. This study demonstrates that the presence of FLT3/ITD, but not D835 (I836), is closely related to aberrant CD2 expression and high expression levels of FLT3 mRNA. Our findings also suggest that FLT3/ITD as a secondary genetic event may block differentiation at the immature stage of APL.

Loss of dopaminoreceptive neuron causes L-dopa resistant parkinsonism in tauopathy.

Frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) is a family of inherited dementias caused by tauopathy. A mutation in exon 10 of the tau gene, N279K, causes a particular kindred of FTDP-17, which is predominant for parkinsonism. The disease initially presents as L-dopa resistant parkinsonism which then rapidly progresses. The final pathological features reveal disappearing dopamine (DA) neurons, but the causes remain poorly understood. We previously established a transgenic mouse with human N279K mutant tau as a model for FTDP-17, which showed cognitive dysfunctions caused by the mutant. Here we analyze L-dopa resistant parkinsonism by several behavioral tests, and focus on the distributions and accumulations of the mutant tau in the DA system by immunohistochemistry and Western blot. Interestingly, dopaminoreceptive (DAr) neurons in the striatum showed neurofibrils degeneration and apoptosis through caspase-3 activation by mutant tau accumulation. The DAr neuron loss in the caudoputamen, the target of the nigrostriatal system occurred before DA neuron loss in young symptomatic mice. Residual DA neurons in the mouse functioned in DA transportation, whereas dysregulation of intracellular DA compartmentalization implied an excess level of DA caused by DAr neuron loss. In the final stages, both DAr and DA neurons decreased equally, unlike Parkinson's disease. Therefore, DAr neurons were fundamentally vulnerable to the mutation indicating a critical role for the L-dopa resistant parkinsonism in tauopathy.

SJLB mice develop tauopathy-induced parkinsonism.

Frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) is an inherited dementia caused by tauopathy. Recently, we established the N279K mutant human tau transgenic mice SJLB. Although SJLB mice show cognitive dysfunction with insoluble tau in the brain, it has remained unclear whether they show signs of parkinsonism. To clarify this issue, we studied whether SJLB mice in fact develop parkinsonism. Behavioral analysis showed shorter stride length than that of non-transgenic control mice in the footprint test and movement disorder in the pole test, thus mimicking some features of human parkinsonism. We also found that these symptoms were not affected by dopamine treatment. These results indicate that SJLB mice show signs of parkinsonism and they could be of usefulness not only for studies of dementing disease but also of parkinsonism induced by tauopathy.

Use of a phosphosensor dye in proteomic analysis of human mutant tau transgenic mice.

Recently, we have generated transgenic mice (designated as SJLB) carrying human N279K mutant tau, one of the tau mutations causing parkinsonism linked to chromosome 17 (FTDP-17). SJLB mice mimic some features of behavioral alterations and neuronal pathology of patients with Alzheimer's disease. To investigate how tau dysfunctions cause these features, we examined the expression and phosphorylation levels in SJLB mouse hippocampal proteins using a phosphosensor dye in two-dimensional poly acrylamide gel electrophoresis analysis and mass spectrometry. Calreticulin and tubulin beta4 are significantly more phosphorylated, and heat shock cognate 71 kDa protein, tubulin beta2, vacuolar ATP synthase catalytic subunit A, alpha-internexin, alpha-enolase, ubiquitin carboxyl-terminal hydrolase isozyme L1, and complexin-2 are significantly less phosphorylated in SJLB mice than control mice. These proteins could be new targets for elucidating underlying mechanisms and therapeutic intervention in neurodegenerative diseases.

Quantitative detection of PML-RARalpha fusion transcript by real-time PCR with a single primer pair.

Quantitative detection of minimal residual disease has prognostic value for some leukemias. Acute promyelocytic leukemia (APL) is characterized by the specific PML-RARalpha fusion gene from t(15;17). Added to three PML-RARalpha isoforms, alternative spliced forms of PML exons give rise to multiple isoforms even within a single patient. To date, multiple primer pairs for the detection of the various PML-RARalpha transcripts have been designed, potentially generating some nonspecific amplification products. Here, we established a real-time quantitative PCR (RQ-PCR) strategy with a single primer pair using LightCycler (sp-RQ-PCR), which could simultaneously detect three isoforms with equal specificity and sensitivity as well as alternative spliced forms. Results obtained with sp-RQ-PCR for 39 samples from 15 APL patients and 31 non-APL samples were compared with those with TaqMan assay with three primer pairs. In two of the APL samples, PML-RARalpha was detected in the TM, but not in the sp-RQ-PCR or nested PCR. Furthermore, the sp-RQ-PCR showed no positive results for the 31 non-APL samples, whereas the TM identified 13% (4/31) as positive. Electrophoresis detected some artifacts in the TM, which do not correspond to PML-RARalpha. We conclude that our sp-RQ-PCR is specific enough to identify various forms of PML-RARalpha and yields no false-positive results.

Usefulness of immature platelet fraction for the clinical evaluation of myelodysplastic syndromes.

Ratios of young platelets or reticulated platelets can be routinely obtained as an immature platelet fraction (IPF) with the XE-2100 automated hematology analyzer (Sysmex, Kobe, Japan). We combined IPF analysis of 31 patients with myelodysplastic syndrome (MDS) with a complete blood count, a bone marrow examination, and a chromosome analysis. The patients with >40 x 10(9)/L platelets were classified as group A, and those with > or =40 x 10(9)/L were placed in group B. The 2 groups were subclassified as A1 or B1 for patients with an IPF of <10% and as A2 or B2 for those with an IPF > or =10%. Categories A1, A2, B1, and B2 comprised 12 patients, 6 patients, 7 patients, and 6 patients, respectively. Patients with a relatively high IPF (>10%) (category A2 or B2) showed distinctive characteristics. Group B2 showed a higher frequency of chromosomal abnormalities than B1 (P = .029), and group A2 tended to show a higher incidence of clinical improvement than A1 (P = .08). IPF determination may be clinically useful for the assessment of prognosis for MDS patients.

MicroRNA-124a is a key regulator of proliferation and monocyte chemoattractant protein 1 secretion in fibroblast-like synoviocytes from patients with rheumatoid arthritis.

OBJECTIVE: To elucidate the role of microRNA (miRNA) in the pathogenesis of rheumatoid arthritis (RA), we analyzed synoviocytes from RA patients for their miRNA expression. METHODS: Synoviocytes derived from surgical specimens obtained from RA patients were compared with those obtained from osteoarthritis (OA) patients for their expression of a panel of 156 miRNA with quantitative stem-loop reverse transcription-polymerase chain reaction. The miRNA whose expression decreased or increased in RA synoviocytes as compared with OA synoviocytes were identified, and their target genes were predicted by computer analysis. We used an in vitro system of enhancing the expression of specific miRNA by transfection of precursors into synoviocytes, and then we performed proliferation, cell cycle, and apoptosis assays, as well as enzyme-linked immunosorbent assays for cytokine production. The effects of transfection on predicted target protein and messenger RNA (mRNA) were then examined by Western blot analysis and luciferase reporter assay. RESULTS: We found that miR-124a levels significantly decreased in RA synoviocytes as compared with OA synoviocytes. Transfection of precursor miR-124a into RA synoviocytes significantly suppressed their proliferation and arrested the cell cycle at the G1 phase. We identified a putative consensus site for miR-124a binding in the 3'-untranslated region of cyclin-dependent kinase 2 (CDK-2) and monocyte chemoattractant protein 1 (MCP-1) mRNA. Induction of miR-124a in RA synoviocytes significantly suppressed the production of the CDK-2 and MCP-1 proteins. Luciferase reporter assay demonstrated that miR-124a specifically suppressed the reporter activity driven by the 3'-untranslated regions of CDK-2 and MCP-1 mRNA. CONCLUSION: The results of this study suggest that miR-124a is a key miRNA in the posttranscriptional regulatory mechanisms of RA synoviocytes.

[Activation of human neutrophils by hemin].

Activation of neutrophils by free heme is considered as one of the mechanisms for cellular dysfunction under the conditions of hemorrhage or tissue damage. We studied about the effects of hemin, ferriprotoporphyrin IX, on human neutrophil activation by measurements of adhesion molecule expression and reactive oxygen species (ROS) production. Human neutrophils purified from heparinized blood of healthy volunteers were stimulated with hemin. Surface expression of CD11b and L-selectin were evaluated by flow cytometry, and superoxide production was detected by chemiluminescence. Hemin increased the expression of CD11b and produced superoxide accompanying by increase in intracellular free calcium concentration. Thus, free heme-molecule is suggested to possess the activity to initiate or aggravate tissue injuries. Since neutrophils do not express CD163, scavenger receptor for hemoglobin-haptoglobin complex, the mechanisms by which hemin exerts these effects are still to be studied.

[Neutrophil function tests and oxidative stress detection as clinical examinations].

We herein introduce several clinically available methods to detect neutrophil function and oxidative stress. The flowcytometric detection of adhesive protein expression, such as CD11b(Mac-1), assessment of phagocytosis activity, and measurement of reactive oxygen species (ROS) production are relatively easy to apply as tools for laboratory medicine. A new device to simultaneously detect superoxide and calcium ion influx is also introduced. Oxidative stress induced by ROS produced not only from phagocytic cells but also from the mitochondria or endoplamic reticulum of all kinds of living cells is etiologically related to many disorders and also aging. A simple method using the FRAS4 instrument is demonstrated. These methods are expected to be clinically beneficial, especially in hematology, transfusion medicine, and the public health field.