Relationship of acid phosphatase activity to ultrastructural features in mice inoculated with Mycobacterium paratuberculosis

Macrophage activation, measured as increased acid phosphatase (AcPase)-positive areas by image analysis, and ultrastructural features were examined in granulomatous mycobacterial lesions of mice innately susceptible (BALB/c mice; Bcg) and innately resistant (C3H/HeJ mice; Bcg) to Mycobacterium paratuberculosis strain ATCC 19698. In the liver and spleen of BALB/c mice 3 weeks after intraperitoneal inoculation with M. paratuberculosis, AcPase activity detected in epithelioid cell nodules was high; it had decreased, however, in the liver and spleen after a further 3 and 6 weeks, respectively. In C3H/HeJ mice, the size of epithelioid cell nodules in the liver and spleen was smaller than in BALB/c mice, and infiltrating macrophages, which had increased by week 9 after inoculation, showed high AcPase activity. Ultrastructurally, by week 32 in BALB/c mice, small phagolysosomes (SPLs) had greatly increased in number in the epithelioid cells. These SPLs contained a few AcPase-positive areas and a small number of bacteria, most of which were surrounded by an electron-translucent space (or electron-transparent zone [ETZ]). In contrast, only a few SPLs were observed in C3H/HeJ mice at week 32; in the liver and spleen, large phagolysosomes (LPLs) showed high AcPase activity and contained many degenerated bacteria, which also had an ETZ. These results suggest that the enzymatic and ultrastructural differences in phagolysosomes between BALB/c mice and C3H/HeJ mice reflect the susceptibility of these mouse strains to M. paratuberculosis.

Essential and non-redundant roles of p48 (ISGF3 gamma) and IRF-1 in both type I and type II interferon responses, as revealed by gene targeting studies

BACKGROUND

Interferons (IFNs) are a class of cytokines which confer cellular resistance against viral infections. Type I (IFN-alpha and -beta) and type II (IFN-gamma) IFNs utilize distinct receptors, the stimulation of which results in the induction of downstream target genes. These target genes usually contain within their promoter region an IFN responsive element, termed ISRE (IFN stimulated response element) which binds a heterotrimeric transcription factor, ISGF3 (IFN-stimulated gene factor 3) consisting of p48 (ISGF3 gamma), Stat1 (Signal transducers and activators of transcription-1; alpha or beta), and Stat2. The ISRE sequence overlaps with that of IRF-E which binds another IFN-inducible factor, IRF-1 (IFN regulatory factor-1).

RESULTS

We generated mice lacking p48 by gene targeting. We show that p48 plays an essential role in both type I and type II IFN responses; activation of IFN-inducible genes and establishment of the antiviral state by IFN-alpha or -gamma are both severely impaired, and ISRE-binding activities induced by both IFNs are absent in the p48-negative embryonic fibroblasts (EFs). Furthermore, we generated mice deficient for both p48 and IRF-1 and found that at least one IFN-inducible gene is dependent on both factors.

CONCLUSIONS

p48 and IRF-1 do not perform redundant functions in the cell, but rather complement one another in both type I and II IFN responses.

Effects of endothelin A and B receptors on aqueous humor dynamics in the rabbit eye

This study attempted to clarify the role of endothelin A and B (ETA and ETB) receptors in modulating aqueous humor dynamics in the rabbit eye. Intraocular pressure (IOP), aqueous flow, total outflow facility, and uveoscleral outflow were measured before, and 24 hours after, intravitreal injection (20 microliters) of a selective ETB agonist, sarafotoxin S6c (SRTX S6c, 10(-5) M), into one eye and its vehicle into the contralateral eye. The measurements were also performed before and after injection of a selective ETA antagonist, 97-139 (10(-2) M) + ET-1 (10(-5) M) into one eye, and vehicle + ET-1 (10(-5) M) into the contralateral eye. In the SRTX S6c-treated eye, total outflow facility increased significantly by 106% compared with that in the vehicle-treated eye 24 hours after injection; aqueous flow and uveoscleral outflow failed to change significantly. The ETA antagonist 97-139 inhibited the decrease in aqueous flow partially, but significantly, but failed to inhibit the increase in total outflow facility caused by ET-1. Therefore, both ETA and ETB play a significant role in modulating aqueous humor dynamics in the rabbit eye. ETA can modulate aqueous humor production, at least in part. ETB can modulate total outflow facility, and the possibility for ETB in modulating aqueous humor formation cannot be ruled out.

Ocular hypotensive mechanism of topical isopropyl unoprostone, a novel prostaglandin metabolite-related drug, in rabbits

This study was performed to clarify the ocular hypotensive mechanism of topical isopropyl unoprostone (unoprostone), a novel prostaglandin (PG) metabolite-related drug, in the rabbit eye. The intraperitoneal administration of indomethacin (50 mg/kg) 1 hour before administration of topical 0.12% unoprostone partially diminished the intraocular pressure (IOP) reduction, and completely blocked the increase in aqueous PGE2 concentration caused by unoprostone. Aqueous humor dynamics measurements in the unoprostone- and the vehicle-treated contralateral eyes with indomethacin pretreatment revealed that aqueous flow determined by fluorophotometry was not significantly different, 2.3 +/- 0.3 and 2.4 +/- 0.2 microliters/min, respectively; the total outflow facility measurements determined by the two-level constant pressure perfusion method were 0.20 +/- 0.01 and 0.14 +/- 0.01 microliters/min/mmHg, respectively (p < 0.05); the uveoscleral outflow measurements determined by the fluorescein isothiocyanate-dextran perfusion method were 0.49 +/- 0.02 and 0.46 +/- 0.02 microliters/min, respectively (p < 0.05). The magnitude of the IOP reduction induced by unoprostone was estimated to be 5.2 mmHg, which agrees well with the actual IOP reduction. In conclusion, unoprostone lowers the IOP by affecting aqueous outflow pathways, primarily the pressure-dependent conventional pathway and the secondary uveoscleral outflow pathway in rabbits. Endogenous PGs induced by topical unoprostone are also involved in lowering the IOP in rabbits.

Identification of a member of the MAPKKK family as a potential mediator of TGF-beta signal transduction

The mitogen-activated protein kinase (MAPK) pathway is a conserved eukaryotic signaling module that converts receptor signals into various outputs. MAPK is activated through phosphorylation by MAPK kinase (MAPKK), which is first activated by MAPKK kinase (MAPKKK). A genetic selection based on a MAPK pathway in yeast was used to identify a mouse protein kinase (TAK1) distinct from other members of the MAPKKK family. TAK1 was shown to participate in regulation of transcription by transforming growth factor-beta (TGF-beta). Furthermore, kinase activity of TAK1 was stimulated in response to TGF-beta and bone morphogenetic protein. These results suggest that TAK1 functions as a mediator in the signaling pathway of TGF-beta superfamily members.

The association among fat distribution, physical fitness, and the risk factors of cardiovascular disease in obese women

The purpose of this study was to see whether fat distribution and physical fitness are independent risk factors of cardiovascular diseases in obese women. Seventy-four obese women aged 19 to 65 years participated in this study. The data were collected on plasma lipid profiles, plasma glucose and insulin during an oral glucose tolerance test, blood pressure, fat distribution determined by the waist to hip ratio (WHR), total body fat determined by the hydrostatic weighing method and a direct measurement of blood lactate threshold. Significant correlations were found between WHR and plasma cholesterol (TC), plasma LDL cholesterol (LDL-c) and LDL-c to the plasma HDL cholesterol ratio (LDL-c/HDL-c), independent of age, percent body fat, and VO2 per lean body mass at blood lactate threshold (LT). On the other hand, LT was significantly related to the area under the curve of insulin during OGTT (insulin area) and DBP, independent of age, percent body fat, and WHR. In conclusion, both fat distribution and physical fitness are considered to be independently related to some important risk factors in obese women after adjustment for percent body fat.

Alterations of low molecular weight acid phosphatase protein level in Alzheimer's disease

We have previously reported that the activity of low molecular weight (LMW) acid phosphatase, which can remove tyrosine-linked phosphates of epidermal growth factor receptor, was significantly decreased in Alzheimer brains. In the present study, a specific antibody was prepared to analyze the protein level of this enzyme. Western blot analysis indicated that the level of LMW acid phosphatase protein was significantly reduced, whereas the activity of LMW acid phosphatase per enzyme molecule was not changed in Alzheimer brains. These results suggest that the reduction of LMW acid phosphatase activity in Alzheimer brains is due to its decreased protein level in Alzheimer's disease.

Neuroprotective effects of NBQX on hypoxia-induced neuronal damage in rat hippocampus

Models of cerebral ischaemia were used for analysis of mechanism of neuronal cell death and/or damage. Ischaemia is caused dominantly by severe hypoxia and hypoglycaemia: in the present study, we examined the influence of severe in vivo hypoxia (5% O2/95% N2 for 30 min at 22 degrees C). After hypoxia, neuronal damage was observed in the CA3 and dentate gyrus (DG) after 3 and 21 days of survival, but not in the CA1.2,3-Dihydroxy-6-nitro-7-sulphamoyl-benzo(F)quinoxaline (NBQX), an antagonist for AMPA/kainate receptors, showed neuroprotective effects in the CA3 and DG. These results suggest that hypoxia may induce neuronal damage in the CA3 and DG through activation of AMPA/kainate receptors.

New design of N-isopropyl-p-[123I]iodoamphetamine (123I-IMP) lung imaging in the patient with lung cancer

N-isopropyl-p-[123I]iodoamphetamine (123I-IMP) was injected intravenously into primary non small cell lung carcinoma patients (n = 17). The average pixel count ratios of the cancerous area to the whole lung was measured in the initial and delayed images. In the initial image, this ratio was less than 1.0 for the entire group of patients, and was thought to reflect decreased blood flow in the cancerous tissues. The rate of counts within a ROI in the delayed image to counts in the same ROI in the initial image was also calculated and called the remain rate. The remain rate (delayed count/initial count) was significantly higher in the cancerous area than in the whole lung (0.65 +/- 0.30, median 0.62, 0.38 +/- 0.05, median 0.38, p < 0.01). This observation was thought to be due to a relative decrease in the blood flow and the accumulation of IMP, which forms pools within the alveolar spaces of the cancerous areas. The image prepared with the remain rate revealed a hot image in the cancerous regions, even when this was not apparent in the delayed image. The remain rate image may therefore be useful in the identification of cancerous areas in lung tissue if it is used in comparison with the initial image.

Detection of monocyte chemotactic and activating factor (MCAF) and interleukin (IL)-6 in human seminal plasma and effect of leukospermia on these cytokine levels

PROBLEM

To demonstrate whether monocyte chemotactic and activating factor (MCAF) and interleukin-6 (IL-6) are present in the seminal plasma, and whether these presence is modulated by leukospermia.

METHODS

Semen samples from 53 men were obtained by masturbation and examined for the presence of MCAF and IL-6 by enzyme immunoassay (EIA). Semen samples were obtained from 28 infertile men without leukospermia, 16 infertile men with leukospermia, and nine proven-fertile men. The correlation between the amount of MCAF in the seminal plasma with some spermiogram parameters and other cytokines such as IL-6 and IL-8 was statistically evaluated.

RESULTS

Immunoreactive MCAF was detected in the seminal plasmas of all 53 subjects. The MCAF titer in the seminal plasma of patients with leukospermia (11.19 +/- 2.75 micrograms/l) was significantly higher than that in the seminal plasma of the patients without leukospermia (3.24 +/- 0.53 micrograms/l) and the fertile men (2.78 +/- 0.35 micrograms/l) (P < 0.001). The IL-6 titer in the seminal plasma of the patients with leukospermia (21.05 +/- 4.49 ng/l) was also significantly higher than that in the seminal plasma of the patients without leukospermia (8.77 +/- 1.92 ng/l) and the fertile men (6.94 +/- 1.27 ng/l) (P < 0.01). There was a high degree of correlation among the levels of MCAF, IL-6 and IL-8 in the seminal plasma.

CONCLUSIONS

These findings demonstrated the presence of MCAF and IL-6 in the seminal plasma, and that the levels of these cytokines were elevated in the seminal plasma of the infertile patients with leukospermia.

[Changes in plasma cytokine levels during lung surgery]

We studied the changes in plasma cytokine (IL-6 and IL-8) levels during lung surgery in 20 patients. The correlation between the changes in cytokine levels and surgical stress as well as the postoperative complications were examined. The levels of IL-6 and IL-8 increased shortly after the surgical incision and were 326 pg.ml-1 and 61 pg.ml-1 respectively, at the end of surgery. The changes in cytokine levels correlated well with the duration of surgery, blood loss and CPR levels for 2 days after the surgery. However, there were no severe postoperative complications in the present study. We conclude that the cytokines increase shortly after the surgical incision and the changes in cytokine levels correlate well with the surgical stress.

Regeneration of plantlets from petiole callus of wild viola (Viola patrinii DC.)

Plantlets were regenerated from 5-year subcultured compact callus derived from petiole tissues of wild viola (Viola patrinii DC.) but not from 5-year subcultured friable callus. Regeneration occurred most efficiently on medium that contained two-fold diluted basal salts of Murashige and Skoog's (MS) medium, 5 × 10(-6) M 1-naphthaleneacetic acid and 10(-6) M kinetin. The effect of dilution of MS basal salts could also be achieved solely by two-fold dilution of the potassium dihydrogen phosphate in the mixture.The present study revealed that dilution of MS basal salts, in particular of potassium dihydrogen phosphate, was important for the regeneration of wild viola. Moreover, although the callus had been subcultured for 5 years, regeneration of plantlets from callus was still possible. In addition, scanning electron microscopy revealed that details of the process of plant regeneration from subcultured callus varied with the age and source of callus and differed from that reported in rice.

IRF-1 and IRF-2 as regulators of the interferon system and cell growth

Interferons (IFNs) are families of cytokines which have been discovered and extensively characterized in the context of host defense against viral infections. We have discovered two structurally related transcription factors, Interferon regulatory factor-1 (IRF-1) and IRF-2. These two factors, however, function not only as regulators of the IFN system, but are also key transcription factors in the regulation of cell cycle and apoptosis. These studies uncover a complex gene transcription network, by which the fate of cellular responses are determined depending on how the IRF transcription factors function in conjunction with other factors, and on the promoters of distinct genes under different conditions of the cells.

Activation of a cell-cycle-regulated histone gene by the oncogenic transcription factor IRF-2

The human histone H4 gene FO108 is regulated during the cell cycle with a peak in transcription during early S phase. The cell-cycle element (CCE) required for H4 histone activation is a sequence of 11 base pairs that binds a protein factor in electrophoretic mobility shift assays that has been designated histone nuclear factor M (HiNF-M). Here we report the purification of HiNF-M, and show it to be a protein of relative molecular mass (M(r)) 48K that is identical to interferon (IFN) regulatory factor 2 (IRF-2), a negative transcriptional regulator of the IFN response. Recombinant IRF-2 (as well as the related protein IRF-1 (ref. 5)) binds the CCE specifically and activates transcription of this H4 histone gene. IRF-2 has been shown to have oncogenic potential, and our results demonstrate a link between IRF-2 and a gene that is functionally coupled to DNA replication and cell-cycle progression at the G1/S phase transition.

The in vitro and in vivo resistance of synthetic enkephalin analogs to three enkephalin-hydrolyzing enzymes

The magnitude of the in vitro and in vivo resistance of 3 synthetic enkephalin analogs, [D-Ala2,Met5]-enkephalin (DAME), [D-Ala2,Met5]-enkephalinamide (DAME-NH2) and [D-Ala2,D-Met5]enkephalin (DADME), to 3 enkephalin-hydrolyzing enzymes, amastatin-sensitive aminopeptidase (AsA), phosphoramidon-sensitive endopeptidase-24.11 (PsE) and captopril-sensitive dipeptidyl carboxypeptidase I (CsD), was estimated by comparing the potency of enkephalins in the absence of the peptidase inhibitor (PI) with that in the presence of the PI. The enhancement of the potency of enkephalins in the isolated mouse vas deferens preparation by 3 PIs, amastatin, phosphoramidon, and captopril, indicated that the resistance of enkephalins to AsA, PsE, or CsD was DADME [symbol: see text] DAME-NH2 [symbol: see text] DAME > [Met5]-enkephalin (ME), DADME > DAME-NH2 > DAME [symbol: see text] ME, or DADME [symbol: see text] DAME-NH2 > DAME > ME, respectively. Additionally, the data obtained by the s.c. administration of enkephalin analogs to 10-day-old rats with or without PI, showed that PsE played the most important role in the inactivation of both DAME and DAME-NH2. In addition to PsE, both AsA and CsD, or AsA alone, played the significant role in the inactivation of DAME, or DAME-NH2, respectively. In the inactivation of DADME, AsA alone played the significant role. These results showed that the 3 peptidases all played important roles in the inactivation of enkephalins, and therefore only an analog like DADME, which was quite resistant to the 3 enzymes, was able to produce the effect without PIs after its systemic administration. Since even DADME was not completely resistant to the 3 enzymes; however, its potency was further increased by pretreatment of infant rats with the PIs.

IL-2-induced gene expression of protein-tyrosine phosphatase LC-PTP requires acidic and serine-rich regions within IL-2 receptor beta chain

A protein-tyrosine phosphatase LC-PTP is preferentially expressed in hematopoietic cells and is an early response gene in lymphokine stimulated cells. Here, we found the LC-PTP mRNA induction by IL-2 was markedly inhibited by several tyrosine kinase inhibitors. The induction required both the acidic and serine-rich regions of the IL-2 receptor beta chain (IL-2R beta) in mouse IL-3-dependent pro-B BAF-B03 transfectants. This is strikingly different from the induction of c-myc gene expression, which requires the serine-rich region alone. In addition, overexpression of activated-Lck or -Raf kinases resulted in augmented LC-PTP mRNA expression in myeloid cell line 32D transfectants. Considering the previous findings that the acidic region of the IL-2R beta is responsible for association with Lck and activation of Raf kinase, IL-2-induced expression of LC-PTP mRNA may be primarily transduced through a Lck-Raf mediated signaling pathway.

Critical role of the interleukin 2 (IL-2) receptor gamma-chain-associated Jak3 in the IL-2-induced c-fos and c-myc, but not bcl-2, gene induction

The interleukin 2 receptor (IL-2R) consists of three subunits, the IL-2R alpha, IL-2R beta c, and IL-2R gamma c chains. Two Janus family protein tyrosine kinases (PTKs), Jak1 and Jak3, were shown to associate with IL-2R beta c and IL-2R gamma c, respectively, and their PTK activities are increased after IL-2 stimulation. A Jak3 mutant with truncation of the C-terminal PTK domain lacks its intrinsic kinase activity but can still associate with IL-2R gamma c. In a hematopoietic cell line, F7, that responds to either IL-2 or IL-3, overexpression of this Jak3 mutant results in selective inhibition of the IL-2-induced activation of Jak1/Jak3 PTKs and of cell proliferation. Of the three target nuclear protooncogenes of the IL-2 signaling, c-fos and c-myc genes, but not the bcl-2 gene, were found to be impaired. On the other hand, overexpression of the dominant negative form of the IL-2R gamma c chain, which lacks most of its cytoplasmic domain, in F7 cells resulted in the inhibition of all three protooncogenes. These results provide a further molecular basis for the critical role of Jak3 in IL-2 signaling and also suggest a Jak PTK-independent signaling pathway(s) for the bcl-2 gene induction by IL-2R.

IL-2 signaling involves recruitment and activation of multiple protein tyrosine kinases by the IL-2 receptor

The IL-2 receptor (IL-2R) consists of three subunits, the IL-2R alpha, IL-2R beta, and IL-2R gamma chains, the last of which is also used in the receptors for IL-4, IL-7, IL-9, IL-13, and IL-15. The IL-2-induced proliferative signals emanate from the cytoplasmic domains of IL-2R beta and IL-2R gamma, but the nature and function of the signaling molecules that transmit these signals are not fully understood. Here we summarize our current understanding of the mechanisms by which IL-2R transmit signals by using multiple protein kinases. In fact, at least four protein tyrosine kinases (PTKs) are physically associated with IL-2R: p56lck (and its members), Syk PTK, and the Janus kinases, Jak1 and Jak3. cDNA expression studies revealed that the activation of these PTKs is critical for IL-2-induced proliferative signal transmission. Our findings indicate that a unique property of the IL-2R cytoplasmic domains is to recruit a variety of signaling molecules, which may suggest a mechanism by which these PTKs and other signaling molecules function in concert.

Serum concentrations of hepatocyte growth factor in breast cancer patients

Hepatocyte growth factor (HGF) was first identified as a potent stimulator of hepatocyte growth and DNA synthesis. Later, it was shown that HGF can promote cell motility and cell proliferation in various types of cells, including tumor cells and endothelial cells. We have examined serum concentrations of HGF in breast cancer patients using an ELISA. Of 134 primary breast cancer patients, 49 (36.6%) showed a significant increase in the circulating level of HGF as compared to healthy controls. The increase in the HGF level was significantly associated with axillary lymph node metastases and histological evidence of venous invasion. No significant correlation between serum HGF concentrations and intratumoral HGF concentrations was found; however, the removal of the primary tumor clearly decreased the serum HGF level, suggesting that the elevation of HGF in the serum was tumor related. Twenty-nine (82.9%) of 35 patients with recurrent breast cancer had an increase in the serum HGF level. The HGF level was significantly higher in patients with liver metastases compared to those with other sites of metastases. Postoperative sequential examinations confirmed that the increase in the serum HGF level was associated with the appearance of relapse. In conclusion, the serum HGF level was significantly increased in breast cancer patients. Circulating HGF might play important roles in tumor progression in this malignancy.

Regulation of the interferon system and cell growth by the IRF transcription factors

Induction of gene transcription in response to extracellular stimuli constitutes an essential aspect of host defense mechanisms. Interferons (IFN) are families of cytokines that have been discovered and extensively characterized in the context of host defense against viral infections. In elucidating the mechanism of transcriptional induction of the IFN genes by viruses, we have discovered two structurally related transcription factors, Interferon regulatory factor 1 (IRF-1) and IRF-2. These two factors, however, function not only as regulators of the IFN system, but are also key transcription factors in the regulation of cell growth and apoptosis. Thus, these studies uncover a complex gene transcription network in which the fate of cellular responses is determined by how the IRF transcription factors function in conjunction with other factors on the promoters of distinct genes under different conditions of the cells.

Altered specificity of IGF2 promoter imprinting during fetal development and onset of Wilms tumour

The specificity of IGF2 promoter imprinting was examined in embryonal tissues and Wilms tumour. In several fetal tissues of approximately 12 weeks gestation, IGF2 was found to be monoallelically expressed from all IGF2 promoters i.e. P1, P2, P3 and P4. However, in tissues of slightly older gestation age (15-17 weeks) relaxation of imprinting at the P1 promoter was evident, although the P2-P4 promoters remained imprinted. These data indicate that early in embryogenesis a population of cells exists in which all IGF2 promoters are imprinted, but that as development proceeds the imprinting of the P1 promoter is relaxed. The pattern of IGF2 promoter imprinting was also analysed in Wilms tumour. In some tumours, the pattern of promoter imprinting was identical to that found in early fetal kidney, indicating that this tumour originates within early embryonic kidney tissue. In contrast, in tumours in which relaxation of imprinting had occurred, imprinting relaxation affected all IGF2 promoters. This aberrant pattern of promoter imprinting, which was not detected in fetal kidney, provides further evidence that pathological relaxation of IGF2 imprinting is involved in the genesis of Wilms tumour.

An IRF-1-dependent pathway of DNA damage-induced apoptosis in mitogen-activated T lymphocytes

Lymphocytes are particularly susceptible to DNA damage-induced apoptosis, a response which may serve as a form of 'altruistic suicide' to counter their intrinsic high potential for mutation and clonal expansion. The tumour suppressor p53 has been shown to regulate this type of apoptosis in thymocytes, but an as yet unknown, p53-independent pathway(s) appears to mediate the same event in mitogen-activated mature T lymphocytes. Here we show DNA damage-induced apoptosis in these T lymphocytes is dependent on the antioncogenic transcription factor interferon regulatory factor (IRF)-1. Thus two different anti-onco-genic transcription factors, p53 and IRF-1, are required for distinct apoptotic pathways in T lymphocytes. We also show that mitogen induction of the interleukin-1 beta converting enzyme (ICE) gene, a mammalian homologue of the Caenorhabditis elegans cell death gene ced-3, is IRF-1-dependent. Ectopic overexpression of IRF-1 results in the activation of the endogenous gene for ICE and enhances the sensitivity of cells to radiation-induced apoptosis.