Regulation of RNG105/caprin1 dynamics by pathogenic cytoplasmic FUS and TDP-43 in neuronal RNA granules modulates synaptic loss

In neurodegenerative diseases, the condensation of FUS and TDP-43 with RNA granules in neurons is linked to pathology, including synaptic disorders. However, the effects of FUS and TDP-43 on RNA granule factors remain unclear. Here, using primary cultured neurons from the mouse cerebral cortex, we show that excess cytoplasmic FUS and TDP-43 accumulated in dendritic RNA granules, where they increased the dynamics of a scaffold protein RNG105/caprin1 and dissociated it from the granules. This coincided with reduced levels of mRNA and translation around the granules and synaptic loss in dendrites. These defects were suppressed by non-dissociable RNG105, suggesting that RNG105 dissociation mediated the defects. In contrast to the model where FUS and TDP-43 co-aggregate with RNA granule factors to repress their activity, our findings provide a novel pathogenic mechanism whereby FUS and TDP-43 dissociate RNA scaffold proteins from RNA granules which are required for local translation that regulates synapse formation.

Probing Superatomic Orbitals of Sc-Doped and Undoped Silver Cluster Anions via Photoelectron Angular Anisotropy

Valence s electrons in alkali- or coinage-metal clusters are conceived to delocalize over the metal frameworks. The electrons occupy so-called superatomic orbitals (SAOs, i.e., 1S, 1P, 1D, 2S, 1F, ...), which provide an essential picture for understanding the size-dependent, unique properties of these metal clusters. While such electronic shells are unambiguously identified in their photoelectron spectra and supported by electronic structure calculations, characterization of SAOs in heteroatom-doped metal clusters has remained elusive as the doping significantly affects its energy levels and even alters the ordering of SAOs. Here, we present a photoelectron imaging study to explore SAOs formed in Sc-doped and undoped silver cluster anions, Ag_NSc^- (N = 15, 16) and Ag_N^- (N = 18, 19). Photoelectron angular distributions from their outermost SAOs are clearly visualized, whose characters are analyzed with the aid of density functional theory calculations. The present methodology enables us to explore not only the quantized energy levels but also the spatial distributions of SAOs formed in various metal cluster anions.

[Exploratory Analysis Results from Post-marketing Surveillance Study of Radium-223 in Japanese Patients with Castration-resistant Prostate Cancer and Bone Metastases: Subgroup Analysis by Age]

OBJECTIVE

To perform an exploratory analysis on the safety and effectiveness of radium-223 (Ra-223) by patient baseline age, using the results of a post-marketing surveillance study of Ra-223 in castration-resistant prostate cancer patients with bone metastasis in Japan.

METHOD

The safety analysis population of 296 patients was stratified into two groups based on age (<75 and ≥ 75 years-old [yo]), and their characteristics, drugrelated treatment-emergent adverse events (TEAEs), and clinical laboratory values were evaluated. Additionally, these endpoints were evaluated in patients aged ≥ 80 yo.

RESULTS

There were 148 patients in each of the <75-yo and ≥ 75-yo age groups, and 69 patients in the ≥ 80-yo age group. The characteristics of patients in the <75-yo group were suggestive of more aggressive disease at diagnosis of prostate cancer and a greater proportion of patients had prior chemotherapy compared with patients in the ≥ 75-yo age group. The incidences of overall drugrelated TEAEs and drug-related hematological TEAEs were slightly higher in the <75-yo age group; however, there was little difference in the incidences of drug-related TEAEs leading to drug discontinuation (1.4-4.1%) between patient groups. Changes in total alkaline phosphatase and prostate-specific antigen values were similar in all groups.

CONCLUSIONS

Ra-223 therapy seemed tolerable regardless of age in real-world practice in Japan. Especially, there were no new safety concerns of Ra-223 in elderly patients.

Real-world safety and effectiveness of radium-223 in Japanese patients with castration-resistant prostate cancer (CRPC) and bone metastasis: exploratory analysis, based on the results of post-marketing surveillance, according to prior chemotherapy status and in patients without concomitant use of second-generation androgen-receptor axis-targeted agents

BACKGROUND

Based on results from Japanese post-marketing surveillance, exploratory analyses were performed to investigate real-world outcomes of radium-223 for metastatic CRPC (mCRPC) according to patient characteristics.

METHODS

This non-interventional, prospective study enrolled mCRPC patients selected for radium-223 treatment in clinical practice. Six-month safety and effectiveness were evaluated in subgroups who had/had not received prior chemotherapy (prior-chemo/no prior-chemo groups), and a subgroup who had not received concomitant androgen-receptor axis-targeted agents (ARATs).

RESULTS

In the overall population (n = 296), the prior-chemo group (n = 126) tended to have more bone metastases, more analgesic use, and higher prostate-specific antigen values than the no prior-chemo group (n = 170). Incidences of treatment-emergent adverse events (TEAEs), drug-related TEAEs, and ≥ grade 3 drug-related hematological TEAEs were 47% vs. 53%, 25% vs. 29%, and 4% vs. 7% in the no prior-chemo and prior-chemo groups, respectively. Incidences of TEAEs (61%), drug-related TEAEs (36%), and ≥ grade 3 drug-related hematological events (12%) were numerically higher in 33 patients who had received two lines of prior chemotherapy. Multivariate analysis showed that two lines of prior chemotherapy, and hemoglobin, platelet, and lactate dehydrogenase values were baseline factors significantly related to ≥ grade 2 platelet count decreased. Safety and effectiveness in patients without concomitant ARATs (n = 201) were similar to those in the overall population.

CONCLUSION

In a real-life setting, radium-223 was well tolerated irrespective of prior chemotherapy, but relatively higher incidences of TEAEs and hematotoxicities were suggested in patients with two lines of prior chemotherapy, possibly reflecting more advanced disease. Radium-223 safety and effectiveness in patients without concomitant ARATs were favorable.

Immunohistochemical analysis for acetylcholinesterase and choline acetyltransferase in mouse cerebral cortex after traumatic brain injury

The regulation of glial cells, especially astrocytes and microglia, is important to prevent the exacerbation of a brain injury because over-reactive glial cells promote neuronal death. Acetylcholine (ACh), a neurotransmitter synthesized and hydrolyzed by choline acetyltransferase (ChAT) and acetylcholinesterase (AChE), respectively, in the central nervous system, has the potential to regulate glial cells’ states, i.e., non-reactive and reactive states. However, the expression levels of these ACh-related enzymes in areas containing reactive glial cells are unclear. Herein we immunohistochemically investigated the distributions of AChE and ChAT with reactive glial cells in the cryo-injured brain of mice as a traumatic brain injury model. Immunohistochemistry revealed AChE- and ChAT-immunopositive signals in injured areas at 7 days post-injury. The signals were observed in and around glial fibrillary acidic protein (GFAP)- or CD68-immunopositive cells, and the numbers of cells doubly positive for GFAP/AChE, GFAP/ChAT, CD68/AChE, and CD68/ChAT were significantly increased in injured areas compared to sham-operated areas. Enzyme histochemistry for AChE showed intensely positive signals in injured areas. These results suggest that reactive astrocytes and microglia express and secrete AChE and ChAT in brain-injury areas. These glial cells may adjust the ACh concentration around themselves through the regulation of the expression of ACh-related enzymes in order to control their reactive states.

Acetylcholine suppresses the increase of glia fibrillary acidic protein expression via acetylcholine receptors in cAMP-induced astrocytic differentiation of rat C6 glioma cells

Astrocytes, the most common glial cells in the central nervous system, maintain neuronal functions and have roles in neurological diseases. Acetylcholine (ACh) is one of the most essential neurotransmitters, and ACh receptor (AChR) ligands were recently reported to influence astrocyte functions. However, the functions of ACh, the only endogenous agonist of AChR, in astrocytogenesis and in the expression of astrocytic marker genes have not been known. We previously demonstrated that the inhibition of acetylcholine esterase (AChE) suppressed the differentiation of rat glioma C6 cells, an astrocyte differentiation model, and we observed a suppressive effect of ACh agonists on astrocyte differentiation. Our present study revealed that in the cAMP-induced differentiation of C6 cells, an AChR antagonist alleviated the expression of glia fibrillary acidic protein (GFAP) that had been suppressed by dichlorvos (DDVP), an organophosphate and an AChE inhibitor. Our findings also demonstrated a direct effect of ACh on the GFAP expression, and that muscarinic AChR is involved in the suppressive effect of ACh on the GFAP expression in differentiation-induced C6 cells. This is the first report indicating that ACh the only endogenous agonist for AChRs functions as a mediator of astrocyte differentiation.

Cyclins in aspergilli: Phylogenetic and functional analyses of group I cyclins

We have identified the cyclin domain-containing proteins encoded by the genomes of 17 species of Aspergillus as well as 15 members of other genera of filamentous ascomycetes. Phylogenetic analyses reveal that the cyclins fall into three groups, as in other eukaryotic phyla, and, more significantly, that they are remarkably conserved in these fungi. All 32 species examined, for example, have three group I cyclins, cyclins that are particularly important because they regulate the cell cycle, and these are highly conserved. Within the group I cyclins there are three distinct clades, and each fungus has a single member of each clade. These findings are in marked contrast to the yeasts Saccharomyces cerevisiae, Schizosaccharomyces pombe, and Candida albicans, which have more numerous group I cyclins. These results indicate that findings on cyclin function made with a model Aspergillus species, such as A. nidulans, are likely to apply to other Aspergilli and be informative for a broad range of filamentous ascomycetes. In this regard, we note that the functions of only one Aspergillus group I cyclin have been analysed (NimECyclin B of A. nidulans). We have consequently carried out an analysis of the members of the other two clades using A. nidulans as our model. We have found that one of these cyclins, PucA, is essential, but deletion of PucA in a strain carrying a deletion of CdhA, an activator of the anaphase promoting complex/cyclosome (APC/C), is not lethal. These data, coupled with data from heterokaryon rescue experiments, indicate that PucA is an essential G1/S cyclin that is required for the inactivation of the APC/C-CdhA, which, in turn, allows the initiation of the S phase of the cell cycle. Our data also reveal that PucA has additional, non-essential, roles in the cell cycle in interphase. The A. nidulans member of the third clade (AN2137) has not previously been named or analyzed. We designate this gene clbA. ClbA localizes to kinetochores from mid G2 until just prior to chromosomal condensation. Deletion of clbA does not affect viability. However, by using a regulatable promoter system new to Aspergillus, we have found that expression of a version of ClbA in which the destruction box sequences have been removed is lethal and causes a mitotic arrest and a high frequency of non-disjunction. Thus, although ClbA is not essential, its timely destruction is essential for viability, chromosomal disjunction, and successful completion of mitosis.

Potentiation of Methylmercury-Induced Death in Rat Cerebellar Granular Neurons Occurs by Further Decrease of Total Intracellular GSH with BDNF via TrkB in Vitro

Brain-derived neurotrophic factor (BDNF) is a principal factor for neurogenesis, neurodevelopment and neural survival through a BDNF receptor, tropomyosin-related kinase (Trk) B, while BDNF can also cause a decrease in the intracellular glutathione (GSH) level. We investigated the exacerbation of methylmercury-induced death of rat cerebellar granular neurons (CGNs) by BDNF in vitro. Since methylmercury can decrease intracellular GSH levels, we hypothesized that a further decrease of the intracellular GSH level is involved in the process of the exacerbation of neuronal cell death. In the present study, we established that in CGN culture, a decrease of the intracellular GSH level was further potentiated with BDNF in the process of the methylmercury-induced neuronal death and also in GSH reducer-induced neuronal death. BDNF treatment promoted the decrease in GSH levels induced by methylmercury and also by L-buthionine sulfoximine (BSO) and diethyl maleate (DEM). The promoting effect of BDNF was observed in a TrkB-vector transformant of the rat neuroblastoma B35 cell line but not in the mock-vector transformant. These results indicate that the exacerbating effect of BDNF on methylmercury-induced neuronal death in cultures of CGNs includes a further decrease of intracellular GSH levels, for which TrkB is essential.

Excited-state dynamics of furan studied by sub-20-fs time-resolved photoelectron imaging using 159-nm pulses

The excited-state dynamics of furan were studied by time-resolved photoelectron imaging using a sub-20-fs deep UV (198 nm) and vacuum UV (159 nm) light source. The 198- and 159-nm pulses produce photoionization signals in both pump-probe and probe-pump pulse sequences. When the 198-nm pulse precedes the 159-nm pulse, it creates the (1)A2(3s) Rydberg and (1)B2(ππ(∗)) valence states, and the former decays exponentially with a time constant of about 20 fs whereas the latter exhibits more complex wave-packet dynamics. When the 159-nm pulse precedes the 198-nm pulse, a wave packet is created on the (1)A1(ππ(∗)) valence state, which rapidly disappears from the observation window owing to structural deformation. The 159-nm photoexcitation also creates the 3s and 3px,y Rydberg states non-adiabatically.

Effect of NS-018, a selective JAK2V617F inhibitor, in a murine model of myelofibrosis

A single somatic mutation, V617F, in Janus kinase 2 (JAK2) is one of the causes of myeloproliferative neoplasms (MPNs), including primary myelofibrosis, and the JAK2V617F mutant kinase is a therapeutic target in MPN. However, inhibition of wild-type (WT) JAK2 can decrease the erythrocyte or platelet (PLT) count. Our selective JAK2 inhibitor, NS-018, suppressed the growth of Ba/F3 cells harboring JAK2V617F more strongly than that of cells harboring WT JAK2. The 4.3-fold JAK2V617F selectivity of NS-018 is higher than the 1.0- to 2.9-fold selectivity of seven existing JAK2 inhibitors. NS-018 also inhibited erythroid colony formation in JAK2V617F transgenic mice at significantly lower concentrations than in WT mice. In keeping with the above results, in a JAK2V617F bone marrow transplantation mouse model with a myelofibrosis-like disease, NS-018 reduced leukocytosis and splenomegaly, improved bone marrow fibrosis and prolonged survival without decreasing the erythrocyte or PLT count in the peripheral blood. By exploring the X-ray co-crystal structure of NS-018 bound to JAK2, we identified unique hydrogen-bonding interactions between NS-018 and Gly993 as a plausible explanation for its JAK2V617F selectivity. These results suggest that NS-018 will have therapeutic benefit for MPN patients through both its efficacy and its reduced hematologic adverse effects.

Dynamic changes in microtubule organization during division of the primitive dinoflagellate Oxyrrhis marina

The marine dinoflagellate Oxyrrhis marina has three major microtubular systems: the flagellar apparatus made of one transverse and one longitudinal flagella and their appendages, cortical microtubules, and intranuclear microtubules. We investigated the dynamic changes of these microtubular systems during cell division by transmission and scanning electron microscopy, and confocal fluorescent laser microscopy. During prophase, basal bodies, both flagella and their appendages were duplicated. In the round nucleus situated in the cell centre, intranuclear microtubules appeared radiating toward the centre of the nucleus from densities located in some nuclear pores. During metaphase, both daughter flagellar apparatus separated and moved apart along the main cell axis. Microtubules of ventral cortex were also duplicated and moved with the flagellar apparatus. The nucleus flattened in the longitudinal direction and became discoid-shaped close to the equatorial plane. Many bundles of microtubules ran parallel to the short axis of the nucleus (cell long axis), between which chromosomes were arranged in the same direction. During ana-telophase, the nucleus elongated along the longitudinal axis and took a dumbbell shape. At this stage a contractile ring containing actin was clearly observed in the equatorial cortex. The cortical microtubule network seemed to be cut into two halves at the position of the actin bundle. Shortly after, the nucleus divided into two nuclei, then the cell body was constricted at its equator and divided into one anterior and one posterior halves which were soon rebuilt to produce two cells with two full sets of cortical microtubules. From our observations, several mechanisms for the duplication of the microtubule networks during mitosis in O. marina are discussed.

Experimental evaluation of photocrosslinkable chitosan hydrogel as injection solution for endoscopic resection

BACKGROUND AND STUDY AIMS

Saline as an injection solution for endoscopic resection techniques has several disadvantages such as a short-lasting effect leading to a potentially higher risk of bleeding and perforation. The new substance of photocrosslinkable chitosan hydrogel in a DMEM/F12 medium (PCH) can be converted into an insoluble hydrogel by ultraviolet irradiation for 30 s, and was evaluated in two sets of animal experiments.

METHODS

18 pigs were used in the two parts of the study. First, mucosal resections were done with either PCH or hypertonic saline; the effects of both agents on wound healing were examined endoscopically and histologically. Second, in vivo degradation of PCH was examined using six pig stomachs.

RESULT

PCH injection led to a longer-lasting elevation with clearer margins, compared with hypertonic saline, thus enabling precise endoscopic submucosal dissection (ESD) along the margins of the elevated mucosa. The endoscopic appearance after ESD was similar in both groups. PCH biodegradation was completed within 8 weeks according to endoscopic and histologic analyses.

CONCLUSION

PCH is a promising agent for submucosal injection prior to various techniques of endoresection. It should be evaluated in clinical trials after biocompatibility testing for PCH is completed.

C-type natriuretic peptide is a Schwann cell-derived factor for development and function of sensory neurones

Cyclic GMP (cGMP) is known to play important roles for neuronal development and neurite pathfinding. However, the regulatory mechanism that governs the synthesis of cGMP in the nervous system is not well defined. In the present study, we examined the role of C-type natriuretic peptide (CNP), which increases intracellular cGMP upon binding to its receptor, guanylyl cyclase (GC)-B, in the peripheral nervous system. Immunohistochemistry revealed that CNP is demonstrated in Schwann cells, whereas GC-B mRNA is highly expressed in dorsal root ganglion (DRG) neurones. In cultured DRG neurones, GC-B was demonstrated in dendrites of TrkA-positive cells, where it co-exists with cGMP-dependent protein kinase I (cGKI), the major intracellular mediator of cGMP actions. Addition of CNP in the culture medium increased the density of fine neurites, which was accompanied by the increase in phosphorylation of vasodilator-stimulated phosphoprotein, a cGKI substrate. Furthermore, in mice deficient for the CNP gene (CNP-KO), the numbers of TrkA-positive DRG neurones were diminished. Likewise, there were much less cGKI-positive neurones in DRG and cGKI-positive fibres in the dorsal spinal cord of CNP-KO than wild-type mice. Finally, the bone deformity-rescued CNP-KO mice displayed a decreased response to formalin-induced pain compared to wild-type. Taken together, these results suggest that CNP is derived from Schwann cells and plays an important role for the development and function of nociceptive sensory neurones.

Association of single nucleotide polymorphisms in endothelin family genes with the progression of atherosclerosis in patients with essential hypertension

Endothelin-1 (ET-1) is a potent vasoconstrictive peptide and its activity is mediated by the receptors ET type A (EDNRA) and ET type B (EDNRB). Although ET-1 is thought to play an important role in the development of atherosclerosis, it remains unclear whether polymorphisms of ET-1 family genes, including the ET-1 gene (EDN1), EDNRA, EDNRB and the genes for endothelin converting enzymes 1 and 2 (ECE1 and ECE2), are associated with the progression of atherosclerosis. We investigated the relationship between 11 single nucleotide polymorphisms (SNPs) of ET-1 family genes (including three in EDN1, one in EDNRA, two in EDNRB, four in ECE1 and one in ECE2) and atherosclerotic changes assessed using pulse wave velocity (PWV) and carotid ultrasonography in 630 patients with essential hypertension (EHT). In male subjects, we found significant differences in brachial-ankle PWV (baPWV) in additive and recessive models in EDNRB-rs5351 after Bonferroni correction. Also in male subjects, there were significant differences in mean intima-media thickness (IMT) in additive and recessive models in EDNRA-rs5333 after Bonferroni correction. We found no significant correlation between any SNPs in the ET family genes and baPWV, IMT and Plaque score (PS) in female subjects. Furthermore, after multiple logistic regression analysis, only EDNRB-rs5351 indicated as an independent risk of atherosclerosis in male hypertensive subjects. Of the endothelin-related genes, EDNRB-rs5351 was the most susceptible SNP associated with atherosclerosis in male hypertensives, and the genetic background may be involved in the progression of atherosclerosis in EHT patients.

Reverse white-coat effect as an independent risk for left ventricular concentric hypertrophy in patients with treated essential hypertension

Recent studies have shown that the converse phenomenon of white-coat hypertension called 'reverse white-coat hypertension' or 'masked hypertension' is associated with poor cardiovascular prognosis. We assessed the hypothesis that this phenomenon may specifically influence left ventricular (LV) structure in treated hypertensive patients. A total of 272 outpatients (mean age, 65 years) with chronically treated essential hypertension and without remarkable white-coat effect were enrolled. Patients were classified into two groups according to office and daytime ambulatory systolic blood pressure (SBP); that is subjects without (Group 1: office SBP > or =daytime SBP, n=149) and with reverse white-coat effect (Group 2: office SBP<daytime SBP, n=123). LV mass index and relative wall thickness were echocardiographically determined. In all subjects, LV mass index and relative wall thickness were positively correlated with daytime and 24-h SBP, but not with office SBP. In addition, these two indices were inversely correlated with office--daytime SBP difference. LV mass index (136+/-31 and 115+/-28 g/m(2), mean+/-s.d.) and relative wall thickness (0.49+/-0.09 and 0.46+/-0.07) were significantly greater in Group 2 than in Group 1. As for LV geometric patterns, Group 2 had a significantly higher rate of concentric hypertrophy compared with Group 1 (48 and 28%). Multivariate analyses revealed that the presence of reverse white-coat effect was a predictor for LV concentric hypertrophy, independent of age, sex, hypertension duration, antihypertensive treatment and ambulatory blood pressure levels. Our findings demonstrate that reverse white-coat effect is an independent risk factor for LV hypertrophy, especially concentric hypertrophy, in treated hypertensive patients.

Evaluation of intrarenal hemodynamics by Doppler ultrasonography for renoprotective effect of angiotensin receptor blockade

AIMS

It has been shown that both angiotensin-converting enzyme inhibitors (ACE-I) and angiotensin II type 1 receptor blockers (ARB) have renoprotective effects via mechanisms that are independent of blood pressure reduction. The aim of this study was to evaluate the intrarenal hemodynamic change with ARB by renal Doppler ultrasonography (RDU) and to assess the mechanism of ARB in patients with hypertension.

METHODS

Thirty hypertensive patients with renal insufficiency caused by glomerular diseases, diabetes and hypertensive nephrosclerosis were included in this study. RDU was performed before and one week after taking ARB. Resistance index (RI) (peak systolic velocity - end diastolic velocity/peak systolic velocity) in the intrarenal segmental artery were calculated, and the amounts of urinary protein or albumin were determined.

RESULTS

We defined patients whose microalbuminuria or proteinuria was reduced by greater than 30% by ARB as responders (n = 22) and defined other patients as non-responders (n = 8). There were no significant differences between the responder and non-responder groups in baseline characteristics. RI was significantly improved by ARB in the responder group, but not in the non-responder group. The reduction of RI after ARB treatment was most prominent in patients with hypertensive nephrosclerosis.

CONCLUSIONS

Improvement in intrarenal hemodynamics might play an important role in the mechanisms of the renoprotective effect of ARB in patients with hypertension.

Left ventricular diastolic dysfunction in patients with chronic renal failure: impact of diabetes mellitus

AIMS

Left ventricular (LV) hypertrophy and LV diastolic dysfunction are cardiac changes commonly observed in patients with chronic renal failure (CRF) as well as hypertension. Although the impairment of LV diastolic function in patients with diabetes mellitus has been shown, little is known about the specific effect of diabetes on LV diastolic function in patients with CRF. The present study was designed to investigate the impact of diabetic nephropathy on LV diastolic dysfunction, independent of LV hypertrophy, in CRF patients.

METHODS

In 67 patients with non-dialysis CRF as a result of chronic glomerulonephritis (n = 33) or diabetic nephropathy (n = 34), and 134 hypertensive patients with normal renal function, two-dimensional and Doppler echocardiographic examinations were performed, and LV dimension, mass, systolic function, and diastolic function were evaluated.

RESULTS

LV mass was increased and LV diastolic dysfunction was advanced in subjects with CRF compared with hypertensive controls. In the comparison of echocardiographic parameters between the two groups of CRF patients, i.e. chronic glomerulonephritis and diabetic nephropathy groups, all indices of LV diastolic function were more deteriorated in the diabetic nephropathy group than in the chronic glomerulonephritis group, although LV structure including hypertrophy and systolic function did not differ between the groups. In a multiple regression analysis, the presence of diabetes (i.e. diabetic nephropathy group) was a significant predictor of LV diastolic dysfunction in CRF subjects, independent of other influencing factors such as age, blood pressure, renal function, anaemia and LV hypertrophy.

CONCLUSION

The present findings suggest that LV diastolic dysfunction, independent of LV hypertrophy, is specifically and markedly progressed in patients with CRF as a result of diabetic nephropathy.

Gamma-tubulin localization changes from discrete polar organizers to anastral spindles and phragmoplasts in mitosis of Marchantia polymorpha L

Unlike the astral mitotic spindle that is organized at discrete centriolar centrosomes, the spindle of land plants is typically anastral and its origin has remained obscure. Gamma tubulin (gamma-tubulin), an important component of the centrosome, has been demonstrated at microtubule-nucleating sites in plant cells. Mitotic spindles of certain hepatics are initiated at distinct acentriolar polar organizers (POs) that appear de novo at the onset of mitosis. Data on the relationship of gamma-tubulin to POs and to microtubule arrays throughout the cell cycle were collected from rapidly dividing cells of Marchantia polymorpha (Bryophyta) that were triple-stained for gamma-tubulin, microtubules, and nuclei. POs at opposite ends of the elongated nucleus in early prophase stain brightly for gamma-tubulin and astral microtubules emanating from them initiate the spindle. As the spindle develops, however, the gamma-tubulin becomes dispersed from the highly concentrated spherical form of the POs to more diffusely organized cups at tips of the fusiform nucleus. By the end of prophase, all astral microtubules have disappeared and the gamma-tubulin is located in several minipoles along the now broad polar regions of the spindle. At metaphase, gamma-tubulin extends into the spindle itself. By telophase, the gamma-tubulin has migrated from distal to proximal surfaces of the sister nuclei and extends into the phragmoplast. Upon completion of cytokinesis, gamma-tubulin appears diminished and surrounds the nuclear envelopes. These data show that gamma-tubulin is only briefly concentrated in the PO, migrates in a cell-cycle-specific manner, and is consistently present at all putative sites of microtubule nucleation.

Inhibitory influences of xanthine oxidase inhibitor and angiotensin I-converting enzyme inhibitor on multinucleated giant cell formation from monocytes by downregulation of adhesion molecules and purinergic receptors

BACKGROUND

Allopurinol, a xanthine oxidase inhibitor, and captopril, an inhibitor of angiotensin I-converting enzyme, are widely used for hyperuricaemia and hypertension, respectively. There have been reported cases showing that these two agents are effective for the treatment of granulomatous diseases such as sarcoidosis, although the mode of action is not elucidated.

OBJECTIVES

We examined the in vitro effects of these agents on the formation of multinucleated giant cells (MGC) from human monocytes by concanavalin A-stimulated mononuclear cell supernatants (conditioned medium).

METHODS

We cultured monocytes with conditioned medium and each agent and compared the rate of MGC formation as well as the expression of adhesion molecules and P2X7 receptor, which are involved in MGC formation.

RESULTS

The addition of 25 or 100 microg mL(-1) allopurinol or 0.125-1.0 microg mL(-1) captopril inhibited MGC formation. Monocytes treated with these agents exhibited less expression of intercellular adhesion molecular-1 (ICAM-1) than untreated monocytes. The susceptibility of monocytes cultured in conditioned medium for 24 h to 2'-and 3'-o-(4-benzoyl-benzoyl)adenosine triphosphate-mediated cytolysis was significantly lower in monocytes treated with these agents than in untreated monocytes.

CONCLUSIONS

Allopurinol and captopril have a therapeutic effect on granulomatous disorders by a direct action on monocyte/macrophage lineage cells partly through downregulation of ICAM-1 and P2X7 receptor.

Diagnostic value of carotid intima–media thickness and plaque score for predicting target organ damage in patients with essential hypertension

Carotid intima-media thickness (IMT) assessed by ultrasonography is regarded as an early predictor of general arteriosclerosis in patients with essential hypertension. However, the methods of measuring IMT have not been globally standardized, and it remains unclear whether conventional measurement of IMT represents the prevalence of hypertensive target organ damage. In this study, we verified the association between several commonly used carotid ultrasonographical parameters and the severity of hypertensive target organ damage (retinal arteriosclerosis, microalbuminuria, left ventricular hypertrophy (LVH)). Carotid ultrasonography, echocardiography, urinalysis, and funduscopy were performed in 184 patients (64 +/- 12 years, 96 males and 88 females) with various stages of essential hypertension. Carotid arteriosclerosis was assessed using four methodologically different methods: conventional-IMT, maximum-IMT (Max-IMT), Mean-IMT, and Plaque Score (the sum of all plaque thicknesses). Age and all carotid ultrasonographical parameters were significantly associated with albuminuria, retinal arteriosclerosis, and left ventricular mass index. High-sensitivity CRP was significantly correlated with retinopathy and LVH. Carotid parameters in patients with histories of cardiovascular events were significantly greater in those without events. Among all carotid parameters, Max-IMT showed the highest correlation coefficient of the severity of target organ damage, and showed significant association with CRP. Stepwise regression analysis revealed that Max-IMT was the independent factor for predicting target organ damage. Max-IMT is suggested to be the most reliable and simplest parameter for predicting hypertensive target organ damage including microangiopathy in patients with essential hypertension.

Induction by staurosporine of hepatocyte growth factor production in human skin fibroblasts independent of protein kinase inhibition

Staurosporine is one of the most potent and well known inhibitors of protein kinases, and it is often used to study the involvement of protein kinases in signal transduction pathways. We now report that staurosporine can induce the production of hepatocyte growth factor (HGF) independently of protein kinase inhibition. Staurosporine markedly stimulated the production of HGF in various cell types, including human skin fibroblasts. Its effect was accompanied by up-regulation of HGF gene expression. The inhibition of protein kinases appears not to be involved in staurosporine-induced HGF production, because other protein kinase inhibitors, K-252a, H-7, GF 109203X and genistein, had no HGF-inducing activity. UCN-01, 7-hydroxystaurosporine, which differs from staurosporine only in its aglycone moiety, also showed HGF-inducing activity, and inactive K-252a differs from staurosporine only in its sugar moiety. These results indicate that the sugar moiety, a six-atom ring structure, is important in the HGF-inducing activity of staurosporine. Experiments were then carried out to determine whether the characteristics of staurosporine-induced HGF production have similarities to those of HGF production stimulated by other HGF inducers. The effect of staurosporine like that of 8-bromo-cAMP and that of cholera toxin was marked in human skin fibroblasts from all four different sources, whereas the effects of epidermal growth factor and phorbol 12-myristate 13-acetate were variable depending on cells. The net increase in HGF production induced by staurosporine was not reduced in protein kinase C-depleted human skin fibroblasts. Moreover, synergistic induction of HGF was detected between staurosporine and interferon-gamma as well as between 8-bromo-cAMP and interferon-gamma. Staurosporine, however, did not increase intracellular cAMP levels in human skin fibroblasts. These results indicate that staurosporine induced HGF in different cell types via a signaling pathway similar to the cAMP-mediated pathway without increasing cAMP levels.

Effects of Roxithromycin on the production of lipase and neutrophil chemotactic factor by Propionibacterium acnes

BACKGROUND

The macrolide antibiotic roxithromycin is effective against acne associated with inflammation, but the mechanism by which this is achieved has not been clarified.

OBJECTIVE

We studied the effects of roxithromycin on the production of lipase and neutrophil chemotactic factor by Propionibacterium acnes in vitro.

RESULTS

Roxithromycin significantly inhibited the production of lipase and neutrophil chemotactic factor by P. acnes at a concentration one eighth of the MIC, at which the growth curve of P. acnes is not affected.

CONCLUSION

One mechanism of the effectiveness of roxithromycin in acne therapy is thought to be the inhibition of bacterial lipase and neutrophil chemotactic factor production by P. acnes.

Localization of matrix proteins of hard tissue in osteochondromas

We examined 10 cases of osteochondroma by means of histopathological, histochemical and immunohistochemical techniques. The surface of the masses was covered with a cartilage tissue showing positive immunohistochemical reaction for collagen type 2, and the deep region was composed of spongy bone, showing positive immunohistochemical reaction for collagen type 1 and osteocalcin. Between the cartilage and spongy bone, which is a metaphysis-like region, a chondroidal pattern appeared in the matrix of hypertrophy cartilage. In these regions, both type 1 (and osteocalcin) and 2 collagens were immunohistochemically detected. Although there is still no direct evidence, we believe that the cells involved in so-called "chondroid bone" temporally express cartilage phenotypes and then transform directly into bone-forming cells that survive in the chondroid bone until the tissue is resorbed and remodeled. Our examination results suggest that bone formation in osteochondromas, at least in some regions, occurs through transchondroid bone formation.

Chronic actinic dermatitis developed during phototherapy for psoriasis

A patient with psoriasis vulgaris had been successfully treated with PUVA and UVB therapy. During maintenance phototherapy, he suddenly became photosensitive and developed eczematous eruption. Minimal response doses to UVB and UVA were extremely low--1.09 mJ/cm2 and 0.3 J/cm2, respectively. No chemical substances were identified as the responsible photosensitizer. The condition was diagnosed as chronic actinic dermatitis (CAD). PUVA therapy was unsatisfactory because it was not possible to administer an adequate dose of UVA. Oral cyclosporine, topical corticosteroid and sunscreen were used with beneficial therapeutic effects on psoriasis and CAD. As far as we know, the development of CAD during phototherapy has not been previously reported.

The effect of antibiotics on the production of superantigen from Staphylococcus aureus isolated from atopic dermatitis

Staphylococcus aureus (S. aureus) often colonizes on the skin of patients with atopic dermatitis. It is known that superantigens which are staphylococcal enterotoxins can activate T cells without processing by antigen presenting cells. It has been suggested that activated T cells release various cytokines which may exacerbate or prolong the cutaneous inflammation associated with atopic dermatitis. Reduction of bacterial colonization from skin lesions has been reported to be effective in the treatment of atopic dermatitis. Therefore, antimicrobial therapy using antibiotics may be a treatment option for atopic dermatitis in selected patients. We examined the effect of antibiotics on the production of superantigen from S. aureus in vitro to determine the action mechanism of antibiotics in the treatment of atopic dermatitis. It was found that antibiotics with inhibitory effect on protein synthesis can suppress the production of superantigen. On the other hand, the superantigen production was not suppressed by antibiotics having either the inhibitory effect on cell wall synthesis or on nucleic acid synthesis. Levels of the suppressive effect on superantigen production by S. aureus varied with strains tested in this study. Moreover, we demonstrated that replication of DNA coding of superantigen produced by S. aureus was suppressed only by roxithromycin (ROX), which is a new macrolide. This finding suggests that ROX may have an effect at the gene level. These results suggested that the suppressive effects of antimicrobial agents that act as inhibitors of protein synthesis on superantigen production from S. aureus may be useful in the treatment of atopic dermatitis.

Role of increased circulating and renal adrenomedullin in rats with malignant hypertension

Although it has been reported that the circulating adrenomedullin (AM) level is elevated in hypertension and renal failure, the pathophysiological significance of circulating and intrarenal AM in malignant hypertension remains unknown. We investigated the circulating and intrarenal AM system in rats with malignant hypertension by measuring the plasma level, renal tissue level, and mRNA abundance of AM and the mRNA abundance of AM receptor. We also investigated the effects of intravenously infused calcitonin gene-related peptide (CGRP)-(8-37), an antagonist of AM, on the hemodynamics and renal tubular function. We studied the following four groups: control Wistar-Kyoto rats (WKY), control spontaneously hypertensive rats (C-SHR), salt-loaded SHR (S-SHR), and DOCA-salt SHR (D-SHR). After 3 wk of DOCA treatment, D-SHR developed malignant hypertension. D-SHR were characterized by higher blood pressure, kidney weight, urinary protein excretion and blood urea nitrogen, and lower creatinine clearance compared with the other three groups. The plasma AM level and urinary excretion of AM were markedly higher in D-SHR than in the other three groups. In the kidney, the tissue AM level and the expression of AM mRNA in the renal medulla were significantly increased in D-SHR compared with the other three groups, whereas there were no significant differences in these levels in the renal cortex among the four groups. In the renal AM receptor system, the expression of the gene for receptor activity modifying protein 3 was significantly increased in the renal medulla in D-SHR compared with the other three groups. An immunohistochemical study revealed that AM immunostaining in renal collecting duct cells and distal tubules was more intense in D-SHR than in the other three groups. After CGRP-(8-37) infusion, blood pressure increased significantly and urinary sodium excretion and urine flow decreased significantly only in D-SHR. These results suggest that the increased circulating AM and renal AM and the increased expression of the mRNA for AM and its receptor may at least partly compensate for the malignant hypertensive state in certain forms of malignant hypertension via the hypotensive, natriuretic, and diuretic actions of AM.

Effects of roxithromycin on adhesion molecules expressed on endothelial cells of the dermal microvasculature

The objective of the study was to investigate the pharmacological action of roxithromycin, an oral macrolide antibiotic. The effects of roxithromycin on the cytokine-induced expression of endothelial leukocyte adhesion molecule (E-selectin) and intracellular adhesion molecule (ICAM)-1 on endothelial cells of the dermal microvasculature were investigated in vitro using flow cytometry. Roxithromycin at a concentration of 0.5 microgram/ml, which is lower than the therapeutic plasma concentration (ordinary daily dose, 150-300 mg), significantly inhibited the expression of E-selectin and ICAM-1 on endothelial cells of the dermal microvasculature induced by tumour necrosis factor-alpha. We conclude that roxithromycin may exert its anti-inflammatory action by inhibition of the in vivo expression of adhesion molecules on dermal microvascular endothelial cells.

Photobiologic and photoimmunologic characteristics of XPA gene-deficient mice

Xeroderma pigmentosum group A (XPA) gene-deficient mice cannot repair UV-induced DNA damage and easily develop skin cancers by UV irradiation. Just like human XP patients, homozygous (-/-) mice developed stronger longer-lasting acute inflammation than did wild-type mice after a single irradiation with UVB. Moreover, the model mice showed more severe UV-induced damage of keratinocytes and Langerhans cells than did the control mice. UVB-induced local and systemic immunosuppression was greatly enhanced in the (-/-) mice. Treatment with indomethacin, an inhibitor of prostaglandin (PG) synthesis, inhibited UV-induced inflammation and abrogated immunosuppression. In XPA-deficient mice, the amount of PGE2 and the expression level of COX-2 mRNA greatly increased after UVB irradiation compared with wild-type mice. These results suggest that the excess DNA photoproducts remaining in XPA-deficient cells after UV radiation induce COX-2 expression and subsequently produce a high amount of PGE2, which causes the enhancement of inflammation and immunosuppression. In XPA-deficient mice, the natural killer cell activity significantly decreased after repeated exposures to UVB. Our experimental data indicate that cancer development in XP patients involves not only mutagenesis due to the defect in DNA repair, but also the enhanced UV-immunosuppression and intensified impairment of natural killer function.

Concentration of roxithromycin in the lesions of acne vulgaris

Roxithromycin, a macrolide antibiotic, is used in the treatment of acne vulgaris, although there have been no reports on its concentration in lesions when administered orally. We investigated the concentration of roxithromycin in acne vulgaris lesions in five patients who received 150 mg roxithromycin orally twice daily for 2 weeks. The mean concentration of roxithromycin in the lesions was 0.54 microgram/ml. These results suggest that roxithromycin accumulates at therapeutic levels in the pilosebaceous system.

Heightened ability of monocytes from sarcoidosis patients to form multi-nucleated giant cells in vitro by supernatants of concanavalin A-stimulated mononuclear cells

The main immunocompetent cells in sarcoidal lesions are epithelioid cells and multi-nucleated giant cells (MGC), both of which are derived from monocyte-macrophage lineage cells. To understand further the relevance of monocytes in sarcoidosis, we examined in vitro MGC formation using monocytes from sarcoidosis patients, patients with other granulomatous diseases (OGD) and healthy control subjects. The supernatant of concanavalin A-stimulated peripheral blood mononuclear cells (conditioned medium) generated Langhans type-MGC and foreign body type-MGC from monocytes. Conditioned medium from any three groups had the same ability to form MGC from normal monocytes. On the other hand, MGC were more highly formed using monocytes from sarcoidosis patients than from other groups. When macrophages induced by treatment of monocytes with macrophage colony-stimulating factor (M-CSF) were used, the rate of MGC formation in sarcoidosis patients was about threefold or fourfold as much as that in OGD patients or healthy controls, respectively. Oxidized ATP inhibited MGC formation in all groups. The susceptibility of monocytes cultured in conditioned medium for 24 h to 2'- and 3'-o-(4-benzoyl-benzoyl)ATP-mediated cytolysis was significantly higher in sarcoidosis patients than other groups. These findings suggest that the ability of monocytes to form MGC through P2x7 receptors is enhanced in sarcoidosis patients.

Crystal structure of Escherichia coli Fdx, an adrenodoxin-type ferredoxin involved in the assembly of iron-sulfur clusters

Escherichia coli ferredoxin (Fdx) is an adrenodoxin-type [2Fe-2S] ferredoxin. Recent genetic analyses show that it has an essential role in the maturation of various iron-sulfur (Fe-S) proteins. Fdx probably functions as a component of the complex machinery responsible for the biogenesis of Fe-S clusters. Its crystal structure was determined by the multiple-wavelength anomalous dispersion method using the iron atoms in the [2Fe-2S] cluster of the protein and then refined to R and R(free) values of 0.255 and 0.278, respectively, at 1.7 A resolution. The structure of Fdx is similar to the structures of bovine adrenodoxin (Adx) and Pseudomonas putida putidaredoxin (Pdx) whose respective root-mean-square deviations of the corresponding Calpha atoms are 1.8 and 2.2 A. This analysis also revealed the structure of the C-terminal residues protruding into the solvent, which is missing in Adx and Pdx. The [2Fe-2S] cluster is located at the edge of the molecule and bonds with the Sgamma atoms of Cys42, Cys48, Cys51, and Cys87. Electrostatic potential analysis showed that the surface of Fdx has two negatively charged areas separated by a hydrophobic lane. One is conserved on the surface of Adx which is an area of interaction with adrenodoxin reductase. Cys46 is located on the molecular surface in the vicinity of the [2Fe-2S] cluster, an indication that it may be involved in Fe-S cluster formation.

Muramyl dipeptide and mononuclear cell supernatant induce Langhans-type cells from human monocytes

Muramyl dipeptide (MDP) in bacterial cell walls reportedly evokes epithelioid cell granulomas. We examined its effects on multinucleated-giant-cell (MGC) formation from monocytes. Supernatant of concanavalin A-stimulated peripheral blood mononuclear cells (conditioned medium) generated MGCs from monocytes. MDP significantly increased the fusion index of Langhans-type MGCs (LGCs) but did not affect total MGCs. N-Acetylmuramyl-L-alanyl-L-isoglutamine, an MDP analogue, had no effect on MGC formation. MGCs were produced by conditioned medium from CD14(++)/CD16(-) monocytes. MDP enhanced the LGC fusion index from CD14(++)/CD16(-) monocytes. MGCs were not produced from CD14(+)/CD16(+) monocytes or immature dendritic cells induced by granulocyte macrophage-colony stimulating factor (GM-CSF) and interleukin (IL) 4 and only weakly produced from macrophage (M)-CSF- or GM-CSF-induced macrophages. Added MDP did not generate MGCs from CD14(+)/CD16(+) monocytes or dendritic cells but enhanced LGC formation from macrophages. Because IFN-gamma, IL-3, and GM-CSF reportedly are important in LGC induction, we added anti-IFN-gamma, anti-IL-3, or anti-GM-CSF monoclonal antibody (mAb) concomitantly to the monocyte culture treated with conditioned medium alone or plus MDP. Anti-IFN-gamma mAb completely abrogated MGC generation, whereas anti-GM-CSF and anti-IL-3 mAbs significantly inhibited LGCs. These findings suggest that CD14(++)/CD16(-) monocytes are fused to form LGCs by MDP derived from granulomatous-disease-causing pathogens with inflammatory mediators such as IFN-gamma, IL-3, and GM-CSF.

Comprehensive analysis of 28 patients with latex allergy and prevalence of latex sensitization among hospital personnel

Recently anaphylactic shock caused by latex gloves and medical instruments has been discussed as an important problem in surgical operations. Patients with contact urticaria or anaphylaxis due to natural rubber latex were first reported in Japan in 1993, and the number of cases is gradually increasing. In the present study, we analyzed 28 patients examined in our clinic from 1993 to 1998. The diagnosis of latex allergy was made on the basis of clinical history, latex specific IgE antibody, skin test, and use test. The 3 male and 25 female patients included 20 nurses, 4 doctors, 2 housewives, one animal hospital employee, and one worker in a senile rehabilitation center. The majority were health care workers. Contact urticaria from rubber gloves was the most common clinical symptom. Some of the patients developed severe attacks of anaphylaxis. During the period from 1995 to 1997, we also performed a questionnaire study and a serum examination of latex specific IgE antibody among the personnel of our university hospital. The screening test for the antibody was more reliable than our questionnaire study in detecting latex-sensitive persons. The prevalence of latex allergy was found to be 4.6%. This indicates that not only dermatologists but also all hospital workers should be aware of this type of allergy.

UV-induced skin carcinogenesis in xeroderma pigmentosum group A (XPA) gene-knockout mice with nucleotide excision repair-deficiency

Nucleotide excision repair (NER) removes a wide variety of lesions from the genome and is deficient in the genetic disorder, xeroderma pigmentosum (XP). In this paper, an in vitro analysis of the XP group A gene product (XPA protein) is reported. Results of an analysis on the pathogenesis of ultraviolet (UV)-B-induced skin cancer in the XPA gene-knockout mouse are also described: (1) contrary to wild type mice, significant bias of p53 mutations to the transcribed strand and no evident p53 mutational hot spots were detected in the skin tumors of XPA-knockout mice. (2) Skin cancer cell lines from UVB-irradiated XPA-knockout mice had a decreased mismatch repair activity and an abnormal cell cycle checkpoint, suggesting that the downregulation of mismatch repair helps cells escape killing by UVB and that mismatch repair-deficient clones are selected for during the tumorigenic transformation of XPA (-/-) cells. (3) The XPA-knockout mice showed a higher frequency of UVB-induced mutation in the rpsL transgene at a low dose of UVB-irradiation than the wild type mice. CC-->TT tandem transition, a hallmark of UV-induced mutation, was detected at higher frequency in the rpsL transgene in the XPA-knockout mice than the wild type mice. This rpsL/XPA mouse system will be useful for further analysing the role of NER in the mutagenesis induced by various carcinogens. (4) The UVB-induced immunosuppression was greatly enhanced in the XPA-knockout mice. It is possible that an enhanced impairment of the immune system by UVB irradiation is involved in the high incidence of skin cancer in XP.

Cause of residual hypertension after adrenalectomy in patients with primary aldosteronism

The cause of residual hypertension after adrenalectomy for primary aldosteronism (PA) is unknown. The purpose of this study is to investigate the characteristic pathological kidney features associated with PA. Between 1977 and 1999 at our hospital, 26 patients with PA caused by a unilateral adrenal cortical adenoma (Conn's syndrome) underwent unilateral adrenalectomy with concurrent open-wedge renal biopsy. Patients were categorized into two groups: (1) those with normotension with diastolic blood pressure less than 90 mm Hg who were not administered antihypertensive drugs, and (2) those with residual hypertension with diastolic blood pressure of 90 mm Hg or greater who were administered medication for 6 months after surgery. Thirteen patients were cured of hypertension postoperatively, and 12 patients were administered antihypertensive medications. Glomerulosclerosis, renal arteriolosclerosis, and preoperative left ventricular mass (LVM) index were worse in the group with residual hypertension than in that with normotension (17.8% +/- 7.8% versus 9.6% +/- 3.8%; P = 0.01; 2.5 +/- 0.5 versus 1.6 +/- 0.4, Bader's grade; P = 0.005; and 165 +/- 31 versus 139 +/- 24 g/m(2); P = 0.02, respectively). Severity of tubulointerstitial injury, preoperative duration of hypertension, preoperative severity of proteinuria, plasma aldosterone level, and serum potassium concentration were not significantly different between the two groups. In conclusion, severity of glomerulosclerosis and arteriolosclerosis and LVM are related to blood pressure after adrenalectomy in patients with PA.

Carcinogen-induced inflammation and immunosuppression are enhanced in xeroderma pigmentosum group A model mice associated with hyperproduction of prostaglandin E2

Xeroderma pigmentosum group A (XPA) gene-deficient mice easily developed skin cancers by the application of topical chemical carcinogens as well as by UV irradiation. As certain chemical carcinogens have been shown to be immunosuppressive, we examined the inflammatory and immunosuppressive effects of dimethylbenz(a)anthracene (DMBA) on XPA mice. Compared with wild-type mice, XPA mice showed greater ear swelling and reduction of epidermal Langerhans cells after DMBA application. Topical application of DMBA impaired the induction of contact hypersensitivity, initiated either locally or at distant sites. These DMBA-induced local and systemic immunosuppressions were more greatly enhanced in XPA mice than in wild-type mice. DMBA application induced pronounced production of PGE(2), IL-10, and TNF-alpha in the skin of XPA mice. Treatment with indomethacin, a potent inhibitor of PG biosynthesis, inhibited DMBA-induced inflammation and local immunosuppression. In XPA mice, increased serum IL-10 was detected after DMBA treatment. Excess production of PGE(2), TNF-alpha, and IL-10 after DMBA application may be involved in the enhanced local and systemic immunosuppression in DMBA-treated XPA mice. Susceptibility to DMBA-induced skin tumors in XPA mice may be due to easy impairment of the immune system by DMBA in addition to a defect in the repair of DMBA-DNA adduct. Enhanced immunosuppression by chemical carcinogens as well as the mutagenicity of these mutagens might be associated with the high incidence of internal malignancies seen in XP patients. Moreover, these results supported the hypothesis that persistent DNA damage is a trigger for the production of immunoregulatory cytokines.

Molecular forms of plasma and urinary adrenomedullin in normal, essential hypertension and chronic renal failure

OBJECTIVES

Human adrenomedullin precursor is converted to glycine-extended adrenomedullin (AM-Gly), an intermediate inactive form of adrenomedullin. Subsequently, AM-Gly is converted to active form of mature adrenomedullin (AM-m). The aim of the present study was to investigate (i) whether sex or age influences plasma and urinary AM-m and AM-Gly levels in normal subjects; (ii) the daytime variability of plasma AM-m and AM-Gly levels in normal subjects; (iii) AM-m and AM-Gly levels and its ratio in plasma and urine in normal subjects, individuals with essential hypertension (HT), and chronic renal failure (CRF); and (iv) the ratio of AM-m and AM-total (T) in plasma of various veins and aorta.

METHODS

We measured plasma levels and urinary excretions of AM-m, AM-Gly and AM-T (AM-m + AM-Gly) by recently developed immunoradiometric assay in normal subjects (n = 81), HT (n = 28) and CRF (n = 30). We also determined the molecular forms of plasma adrenomedullin taken from various sites during angiography in patients with suspected renovascular hypertension (n = 9).

RESULTS

There were no differences in plasma and urinary excretions of two molecular forms of adrenomedullin among sexes or ages in normal subjects. There was no daytime variation of plasma two molecular forms of adrenomedullin in normal subjects. Plasma AM-m, AM-Gly and AM-T levels were increased in patients with HT and CRF compared with normal subjects, whereas urinary AM-m, AM-Gly and AM-T excretions were decreased in patients with HT and CRF compared with normal subjects. Urinary AM-m: AM-T ratios were significantly higher than plasma AM-m: AM-T ratios. Plasma AM-m and AM-T levels taken from various veins were similar, and they were significantly higher than those of aorta, although there were no differences in plasma AM-Gly levels between aorta and veins.

CONCLUSIONS

These results suggest that in normal subjects, and individuals with HT and CRF: (i) plasma and urinary excretions of AM-m and AM-Gly are not affected by age or sex; (ii) AM-m in parallel with AM-Gly is increased; (iii) urine contains a higher percentage of active adrenomedullin than plasma; and (iv) plasma AM-m may be partly metabolized in the lung.

Activation of Fc epsilon RI-positive eosinophils in bullous pemphigoid

Bullous pemphigoid (BP) is an autoimmune disease frequently occurring in elderly persons. It has been reported that 92-kDa gelatinase released from eosinophils cleaves the extracellular domain of BP180 protein, suggesting a direct role of eosinophils in bulla formation in this disease. The expression of the high-affinity IgE receptor, Fc epsilon RI, on eosinophils was examined in patient with BP. Samples of affected skin obtained from 7 patients with BP were stained immunohistochemically by the alkaline phosphatase anti-alkaline phosphatase (APAAP) method and mirror sections were examined. Eosinophils were present at a rate of 1.0-19.0% in lesions of the dermis, and the number of IgE-positive cells exceeded that of Fc epsilon RI-positive cells in all cases. These cells were not detected in the epidermis, and examination of mirror sections confirmed that the Fc epsilon RI-positive cells corresponded to eosinophils. It has been demonstrated that Fc epsilon RI-positive cells are involved in the dermal lesions of BP. The activation of eosinophils by Fc epsilon RI may participate in the pathogenesis of BP by triggering the degranulation of mast cells.

Alterations of intrarenal adrenomedullin and its receptor system in heart failure rats

Calcitonin receptor-like receptor/receptor activity-modifying protein 2 (CRLR/RAMP2) and CRLR/RAMP3 complexes have been reported to be specific adrenomedullin (AM) receptors. In the present study, we evaluated the pathophysiological significance of renal AM and its receptor system in aortocaval shunt (ACS) rats. Renal AM levels were measured serially during 5 weeks after the operation. Renal gene expressions of AM, CRLR, RAMP2, and RAMP3 were measured at 2 weeks (decompensated phase) and 5 weeks (compensated phase) after the operation. Immunohistochemical localizations of renal AM were also evaluated. Furthermore, the relations between urinary sodium excretion (UNaV) and renal AM levels were evaluated. Renal AM levels were higher in ACS than in control animals only at 1, 2, and 3 weeks after the operation. At 2 weeks after the operation, renal AM mRNA expression was also higher in ACS than in control animals. CRLR, RAMP2, and RAMP3 mRNAs were expressed in the kidney, but there were no differences between the 2 groups. Immunohistochemistry revealed the positive AM immunostaining within the renal tubular cells, and it was more intense in ACS than in control animals. There were significant correlations between UNaV and renal AM levels. At 5 weeks after the operation, there were no differences in mRNA levels of AM, CRLR, RAMP2, and RAMP3 between the 2 groups. There was a significant correlation between UNaV and medullary AM levels. The present findings suggest that increased renal AM levels in decompensated heart failure, presumably due to increased AM production in renal tubules, in part, are involved in the regulation of sodium excretion.