Immunocytochemical localization of salivary peptide P-C in human submandibular gland

Human saliva contains a proline-rich polypeptide, salivary peptide P-C, which potentiates insulin release and reduces glucagon release from perfused rat pancreas to decrease blood glucose level. To elucidate the process of secretion into humoral fluid of this peptide morphologically, we investigated ultrastructural localization of P-C in human submandibular gland by immunogold technique with anti-peptide P-C whose specificity to P-C was confirmed by immunoblotting. The labeling with gold particles which represents the distribution of P-C-like-immunoreactivity (P-C-LI) was detected in the secretory granules and rough endoplasmic reticula of the acinar serous cells and in few mucosa cells. P-C-LI was also observed in the lumen of striated duct but not intracellularly in the ductal cells themselves, indicating that P-C is not probably reabsorbed there. These results suggest that salivary peptide P-C is present in acinar serous cells, is secreted into the oral cavity, and may be reabsorbed through the digestive tract to modulate the blood glucose level after feeding.

Inhibitory effects of anti-rheumatic drugs containing magnosalin, a compound from 'Shin-i' (Flos magnoliae), on the proliferation of synovial cells in rheumatoid arthritis models

This study was undertaken to examine the effects of magnosalin, a compound isolated from 'Shin-i' (Flos magnoliae) on proliferation of synovial cells isolated from MRL/1pr and collagen-induced arthritis (CIA) mice, and rheumatoid arthritis (RA) patients. Magnosalin (2.39-23.9 microM) inhibited 5% fetal bovine serum (FBS)-stimulated [3H]-thymidine incorporation into the synovial cells in the MRL/1pr mice. The effect of magnosalin was greater than that of hydrocortisone, bucillamine and magnoshinin (another compound from 'Shin-i'), but weaker than that of corticosterone. The effects of magnosalin for FBS-induced thymidine incorporation into the cells of the CIA mice and the RA patients were significantly greater than those in the corresponding control mice and osteoarthritis patients. Interleukin (IL)-1alpha increased the incorporation of thymidine into the synovial cells in the C57BL/6J mice to a greater degree than did basic fibroblast growth factor (bFGF) or platelet-derived growth factor BB-homodimer (PDGF-BB). The inhibitory effect of magnosalin on the submaximal action of IL-1alpha was significantly greater than that of bFGF, PDGF-BB or FBS. These results offer evidence that magnosalin suppresses the proliferation of synovial cells in RA models by inhibiting IL-1alpha-stimulated action.

[Influence of infusion solution on the vascular permeability in rat skin]

In this study, we attempted to confirm the assessment system of incidence of angialgia and thrombophlebitis by evaluating the influence of test solutions on the vascular permeability by intradermal injection into rat skin, and following results were obtained: 1) Dimensions of dye leakage in the rat skin were not increased by injection of one commercially available preparation (solution 1), but increased significantly by injection of a preparation (solution 2) that had induced a high incidence of angialgia in a clinical study. 2) Dimensions of the dye leakage increased significantly by injection of glucose solutions with about four degrees of osmolality ratio. 3) In the injection of acetate buffers with different titratable acidity, dimensions of the dye leakage increased depending on titratable acidity. 4) Solution 1 was adjusted to pH 4.43 with L-lactate, acetic acid of HCl, and then these solutions were intradermally injected to rats. The influence on dimensions of the dye leakage was in the following order of strength: acetic acid >> L-lactate > HCl. These results suggest that the vascular permeability by injection into rat skin is influenced by osmolality, pH, titratable acidity and composition of test solutions. Therefore, this system using the vascular permeability reaction in rat skin may be useful for evaluation of angialgia and thrombophlebitis incidence.

Muscarinic M1 receptor activation reduces maximum upstroke velocity of action potential in mouse right atria

We investigated whether acetylcholine affects cardiac action potentials through the muscarinic M1 in addition to M2 receptors in spontaneously beating mouse isolated right atria. A conventional glass microelectrode technique was used for the purpose. Acetylcholine (3-10 microM) reduced the maximum upstroke velocity of the action potentials (Vmax), followed by an increase. It shortened action potential duration at 90% repolarization, hyperpolarized the resting membrane and decreased the rate of beating. Atropine (3-100 nM) concentration dependently antagonized these effects of acetylcholine. Pirenzepine (10 and 30 nM), a selective muscarinic M1 receptor antagonist, antagonized acetylcholine (5 microM)-induced reduction of Vmax without affecting other effects of acetylcholine. In addition, pirenzepine (30 nM) induced an immediate and linear acceleration of the VmaX reduced by acetylcholine. In contrast, AF-DX 116 (11(¿2-[(diethylamino)-methyl]-1-piperidyl¿acetyl)-5,11-dihydro-6 H-pyridol[2,3-b][1,4]benzodiazepine-6-one base, 30-300 nM), a selective muscarinic M2 receptor antagonist, failed to antagonize acetylcholine-induced reduction of Vmax, but abolished its increase. It antagonized the shortening of action potential duration, membrane hyperpolarization and decreased the beating rate. McN-A-343 (4-(m-chlorophenyl-carbamoyloxy)-2-butynyltrimethylammonium chloride, 100 and 300 microM), a muscarinic M1 receptor agonist, reduced Vmax and prolonged action potential duration, while oxotremorine (100-300 nM), a muscarinic M2 receptor agonist, evoked reverse effects. These results suggest that acetylcholine exerts a mixed effect on Vmax, consisting of a reduction and a facilitation, possibly mediated by concurrent activation of muscarinic M1 and M2 receptors, respectively, in isolated right atria of mice.

A mixture of synthetic oligonucleotide probes labeled with biotin for the sensitive detection of potato spindle tuber viroid

Five kinds of synthetic oligonucleotide probes labeled with biotin (BIO) were designed for the detection of potato spindle tuber viroid (PSTVd), and their sensitivities were compared with that of a digoxigenin (DIG)- or BIO-labeled cDNA probe. Although each oligonucleotide probe alone was less sensitive than the DIG-cDNA probe, sensitivity was increased by using a mixture of two or all of the five oligonucleotide probes. The sensitivity of a PSmix1-5 probe, which was a mixture of five oligonucleotides, was the same as that of a DIG-labeled cDNA probe, which can detect 7.8 pg of purified PSTVd and PSTVd in nucleic acids, equivalent to extracts from 20 microg of infected potato leaf and 310 microg of infected potato tuber. Using the PSmix1-5 probe, PSTVd in all leaves and tubers of seven potato cultivars could be detected without any background. Moreover, with the PSmix1-5 probe, the hybridization time could be shortened to 2 h without any decrease in sensitivity, whereas the sensitivity of the cDNA probes clearly decreased when the hybridization time was shortened. Hybridization using a mixture of several oligonucleotide probes may be applicable to the gene diagnosis of other viroids and viruses.

Inhibitory effects of tetrandrine on angiogenesis in adjuvant-induced chronic inflammation and tube formation of vascular endothelial cells

The inhibitory effects of tetrandrine (an alkaloid isolated from the Chinese medicine Stephania tetrandrae S. Moore) were investigated in terms of the angiogenesis in an adjuvant-induced chronic inflammation model of mouse and tube formation of rat vascular endothelial cells (EC). Tetrandrine (7.5-30 mg/kg) reduced the carmine content, granuloma weight, inflammatory cell count and pouch fluid weight in the inflammation model in a dose-dependent manner. The inhibitory pattern of tetrandrine on these parameters was similar to that of hydrocortisone. The inhibitory effect of tetrandrine on carmine content was 0.56-fold smaller than that of hydrocortisone. Tetrandrine (0.1-10 microM) also inhibited 2% fetal bovine serum (FBS)-stimulated tube formation of vascular EC. The inhibitory effect of tetrandrine on tube formation was more than 100-fold greater than that of hydrocortisone. Tetrandrine (10-30 nM) inhibited the tube formation stimulated by interleukin (IL)-1alpha and platelet-derived growth factor (PDGF)-BB to a greater extent than FBS-stimulated tube formation. The inhibitory effects of tetrandrine on the action of IL-1alpha and PDGF-BB were non-competitive. These results demonstrate that tetrandrine may reduce the tube formation of EC in the angiogenic process through inhibition on the post-receptor pathway of IL-1alpha and PDGF-BB in chronic inflammation.

Acetylcholine sensitivity of biphasic Ca2+ mobilization induced by nicotinic receptor activation at the mouse skeletal muscle endplate

1. Acetylcholine (ACh) was locally applied onto the endplate region in a mouse phrenic nerve-diaphragm muscle preparation to measure intracellular free calcium ([Ca2+]i) entry through nicotinic ACh receptors (AChRs) by use of Ca2+-aequorin luminescence. 2. ACh (0.1-3 mM, 20 microl) elicited biphasic elevation of [Ca2+]i (fast and slow Ca2+ mobilization) in muscle cells. The peak amplitude of the slow Ca2+ mobilization (not accompanied by twitch tension) was concentration-dependently increased by ACh, whereas that of the fast component (accompanied by twitch tension) reached a maximum response at a lower concentration (0.1 mM) of applied ACh. 3. A pulse of nicotinic agonists, (-)-nicotine (10 mM) and 1,1-dimethyl-4-phenyl-piperazinium (10 mM), but not a muscarinic agonist pilocarpine (10 mM), also elicited a biphasic Ca2+ signal. 4. Even though ACh release from motor nerve endings was blocked by botulinum toxin (5 microg, bolus i.p. before isolation of the tissue), the generation of both a fast and slow Ca2+ component caused by ACh application was observed. 5. These results strongly suggest that ACh locally applied onto the endplate region of skeletal muscle induces a slow Ca2+ signal reflecting Ca2+ entry through a postsynaptic nicotinic AChR, which has a low sensitivity to transmitter ACh.

Calcium-dependent desensitizing function of the postsynaptic neuronal-type nicotinic acetylcholine receptors at the neuromuscular junction

Several subunits that commonly have been regarded as neuronal-type nicotinic acetylcholine receptor (nAChR) subtypes, have been found in the postjunctional endplate membrane of adult skeletal muscle fibres. The postsynaptic function of these neuronal-type nAChR subtypes at the neuromuscular junction has been investigated by using aequorin luminescence and fluorescence confocal imaging. A biphasic elevation of intracellular Ca2+ is elicited by prolonged nicotinic action at the mouse muscle endplates. The fast and slow Ca2+ components are operated by a postsynaptic muscle- and colocalized neuronal-type nAChR, respectively. Neuromuscular functions may be regulated by a dual nAChR system to maintain the normal postsynaptic excitability. Certain neuronal-type nAChR may be endowed with the same functional role in the central nervous system also.

Antihyperglycemic effects of N-containing sugars from Xanthocercis zambesiaca, Morus bombycis, Aglaonema treubii, and Castanospermum australe in streptozotocin-diabetic mice

The aqueous MeOH extract of the leaves and root of Xanthocercis zambesiaca (Leguminosae) and eight structurally related nitrogen-containing sugars, fagomine (1), 4-O-beta-D-glucopyranosylfagomine (2), 3-O-beta-D-glucopyranosylfagomine (3), 3-epifagomine (4), 2,5-dideoxy-2,5-imino-D-mannitol (5), castanospermine (6), alpha-homonojirimycin (7), and 1-deoxynojirimycin (8) were evaluated for antihyperglycemic effects in streptozotocin (STZ)-diabetic mice. The insulin-releasing effects of 1 were also investigated. The blood glucose level fell after i.p. injection of the extract (50 mg/kg). Compounds 1, 2, 5, and 6 reduced the blood glucose level after i.p. injection of 150 mumol/kg. Compound 1 increased plasma insulin level in STZ-diabetic mice and potentiated the 8.3-mM glucose-induced insulin release from the rat isolated-perfused pancreas. The 1-induced potentiation of insulin release may partly contribute to antihyperglycemic action.

Clinical, functional, and radiographic assessments of the conventional and modified Boyd-Anderson surgical procedures for repair of distal biceps tendon ruptures

The purpose of this study was to evaluate the clinical, functional, and radiographic outcomes of the conventional and modified Boyd-Anderson procedures for repair of distal biceps tendon ruptures. Thirteen of 18 men who underwent surgical repair for unilateral distal biceps tendon ruptures at one university center participated in the study. In general, follow-up outcomes were favorable with respect to return to premorbid activity levels, patient satisfaction with surgical outcome, and overall clinical results. Elbow flexion, forearm supination, and upper extremity functional concentric peak torque and range of motion results were not significantly different between the surgical and nonsurgical arms when dominance was controlled as a confounding factor. Radiographic findings revealed no clinically remarkable signs of heterotopic ossification or proximal radioulnar synostosis. Results of the study reveal that the conventional and modified Boyd-Anderson procedures are clinically, functionally, and radiographically efficacious for repair of distal biceps tendon ruptures.

The loss of outer capsid protein P2 results in nontransmissibility by the insect vector of rice dwarf phytoreovirus

A transmission-defective (TD) isolate of rice dwarf phytoreovirus lacked the ability to infect cells when derived from the virus-free insect vector Nephotettix cincticeps. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified virus showed that among six structural proteins, the P2 outer capsid protein (encoded by genome segment S2) was absent from the TD isolate, whereas all six proteins were present in the transmission-competent (TC) isolate. P2 was not detected on immunoblots of rice plants infected with the TD isolate. Genome segment S2 and its transcript were detected in both TD and TC isolates. Sequence analysis of the S2 segment of the TD isolate revealed the presence of a termination codon due to a point mutation in the open reading frame, which might explain the absence of P2 in the TD isolate. These results demonstrate that the P2 protein is one of the factors essential for infection by the virus of vector cells and, thus, influences transmissibility by vector insects.

[Slow Ca2+ (RAMIC) mobilization operated by postsynaptic neuronal nicotinic receptor regulates synaptic function at the mouse neuromuscular junction]

We have found that non-contractile slow Ca2+ mobilization (RAMIC; Receptor-Activity Modulating Intracellular Ca2+) is generated by motor nerve stimulation with anti-cholinesterase at the skeletal muscle, and desensitizes muscle nicotinic receptor (nAChR). To confirm this Ca2+ mobilization without anti-cholinesterase, acetylcholine (ACh) was locally applied by N2-gas pressure onto endplate region at the mouse phrenic nerve-diaphragm muscle preparation. ACh (0.1-3 mM, 20 microliters) elicited bi-phasic elevation of [Ca2+]i (fast and slow Ca2+ mobilization measured as Ca(2+)-aequorin luminescence) in muscle cells. The peak amplitude of slow Ca2+ mobilization (not accompanied by contraction) was increased by ACh concentration-dependently, whereas that of fast component (accompanied by contraction) reached a maximum response at a lower concentration of ACh. The slow Ca2+ mobilization was blocked by lower concentrations of competitive nAChR antagonists which did not affect the fast Ca2+ transients. Moreover, the slow Ca2+ signal was selectively depressed by a neuronal nAChR antagonist methyllycaconitine. Neither Ca2+ channel blockers nor a Na+ channel blocker tetrodotoxin prevented the generation of the slow Ca2+ mobilization. These results suggest that RAMIC is mobilized through postsynaptic neuronal nAChR subtype to desensitize muscle nAChR at the neuromuscular junction.

Aconitine induces bradycardia through a transmission pathway including the anterior hypothalamus in conscious mice

Aconitine administered intraperitoneally (i.p.) produces bradycardia mainly by a central muscarinic action. The involvement of hypothalamic regions in the occurrence of aconitine-induced bradycardia was investigated in hypothalamus-lesioned mice. The lesions were made by passing a direct current (1.5 mA, 13 s) through a monopolar electrode. The aconitine (30 micrograms/kg, i.p.)-induced bradycardia was prevented by bilateral lesions of either the whole hypothalamus, except for the lateral hypothalamus area, or the anterior hypothalamus (AH). The bradycardia was not prevented by bilateral lesions of the ventromedial, the paraventricular, the posterior or the lateral hypothalamus regions. Bupivacaine, but not atropine (1 microgram, administered into the intact AH) prevented aconitine-induced bradycardia in mice with a contralaterally lesioned AH. Aconitine (0.8 microgram) directly administered into the unilateral AH in intact mice caused a late phase and lesser extent of bradycardia. These results suggest that a transmission pathway including the AH contributes to the aconitine-induced bradycardia but does not involve the activation of muscarinic receptors in the AH.

Platelet-derived growth factor blocks the cell-cycle transition from the G0 to G1 phase in subcultured angiogenic endothelial cells in rat thoracic aorta

Platelet-derived growth factor (PDGF)-BB induces tube formation by the differentiating (tube-forming) endothelial cells (EC) of rat thoracic aorta, although PDGF-BB does not affect the proliferative EC (increasing the cell numbers) at the progression phase. These changes in the responses to PDGF-BB were due to the phenotype-dependent expression of PDGF beta-receptor (PDGFR-beta) on EC because PDGFR-beta-like immunoreactivity was observed in the angiogenic EC forming a tube-like structure in 35-day culture with 10% fetal bovine serum, but not in the proliferative EC in 5-day culture. To elucidate the functional role of PDGFR-beta in the alteration of EC phenotype, the influence of PDGF-BB on the cell cycle of EC was investigated by flow cytometry. This analysis demonstrates that PDGF-BB blocks the transition from the G0 to G1 phase in the 35-day cultured EC, although no effect was observed on any phases of the cell cycle in 5-day culture. We conclude that 1) PDGFR-beta is expressed in mature angiogenic EC of rat aorta, and 2) PDGF-BB may contribute to promotion of the EC differentiation with tubular morphogenesis by inhibiting cell growth.

[Menogaril (TUT-7) late phase II study for malignant lymphoma, adult T-cell leukemia and lymphoma (ATLL)]

A late Phase II multicenter study with menogaril was conducted nationwide in patients with malignant lymphoma [non-Hodgkin's lymphoma (NHL), Hodgkin's disease (HD)], and ATLL, menogaril was orally administered at 100 mg daily after breakfast, for seven consecutive days with two- or three-week drug withdrawal, then menogaril administration was repeated. For malignant lymphoma, in 81 patients with NHL and 5 patients with HD registered, 70 and 5 patients were evaluable for efficacy, respectively. The efficacy rates were 32.9% (6 CRs + 17 PRs/70) for NHL and 20.0% (1 PR/5) for HD, respectively; that for the NHL patients with prior anthracycline antibiotic chemotherapy was 30.5% (5 CRs and 13 PRs/59). For ATLL, among the 16 patients registered, 15 were evaluable for efficacy, and the efficacy rate was 40.0% (2 CRs and 4 PRs/15). Adverse drug reactions frequently observed in the patients with malignant lymphoma and ATLL included bone-marrow suppression and gastrointestinal symptoms such as anorexia, and nausea/vomiting. With these results, menogaril was considered to be effective for the treatment of non-Hodgkin's lymphoma and ATLL.

Mutual dependence of calcitonin-gene related peptide and acetylcholine release in neuromuscular preparations

To investigate the mutual dependence of calcitonin gene-related peptide (CGRP) and acetylcholine release, we examined the effect of a cholinesterase inhibitor neostigmine on the release of CGRP-like immunoreactivity in rat phrenic nerve-hemidiaphragm muscle preparation, and conversely, the effect of CGRP on [3H]acetylcholine release from motor nerve terminals loaded with [3H]choline in the same preparations of mice. Release of CGRP-like immunoreactivity was increased by electrical nerve stimulation (train of 40 pulses of 200 micros pulse duration and frequency of 50 Hz applied every 10 s) in the whole preparation but not in the segmental preparation containing the endplate region. Neostigmine (0.1-0.3 microM) enhanced the resting release of CGRP-like immunoreactivity in a concentration-dependent manner, whereas it depressed the nerve-evoked release of CGRP-like immunoreactivity. CGRP (1 microM) added to perfusate decreased nerve-evoked [3H]acetylcholine release. These results suggest that CGRP, which is released by electrical nerve stimulation or a cholinesterase inhibitor in intact skeletal muscles, negatively modulates nerve-evoked acetylcholine release.

Human alveolar macrophages synthesize endothelins by thrombin

Alveolar macrophages (AM) play pivotal roles in the defense mechanism and the regulation of inflammatory processes in the airways. Macrophages express receptors for thrombin on their surfaces, and thrombin induces the chemotaxis and the proliferation of macrophages. Thrombin acts on vascular endothelial cells to synthesize endothelin (ET)-1. AM have been known to express prepro ET-1 mRNA. Thus, we hypothesized that thrombin stimulates AM so as to synthesize ET. Surgically resected human lungs were irrigated by saline to remove intravascular blood, then saline was instilled into the bronchus, and the fluids were recovered. AM were separated by Percoll density centrifugation (density, 1.060 g/ml). AM were resuspended in culture medium without FCS in the presence or absence of thrombin. ET was synthesized by thrombin in a concentration-dependent manner, and the amounts of ET synthesized by thrombin (10 U/ml) were equivalent to those by LPS (10 microg/ml). Dexamethasone (10(-6)-10(-10) M), IL-4 (100 U/ml), and TGF-beta (10 ng/ml) significantly suppressed the ET synthesis by thrombin (p < 0.05). In contrast, 1,25-dihydroxyvitamin D3 (10(-8)-10(-10) M) enhanced the ET synthesis up to approximately 300%. The analysis using high pressure liquid chromatography revealed that AM-derived ET consists of ET-1, ET-2, and ET-3. Major constituents were ET-2 and ET-1, and the ratio of ET-2/ET-1 was 1.7 +/- 0.4 (mean +/- SE). These results indicate that thrombin is a potent agonist for AM to synthesize ET.

Evaluation of bone marrow iron by magnetic resonance imaging

Bone marrow iron was estimated by magnetic resonance imaging (MRI) using spin-echo sequences with multiple echoes in 22 patients with varying degrees of tissue storage iron. Levels of bone marrow iron concentration (BMIC) were determined chemically in biopsied specimens concurrently. Concentrations of serum iron, serum ferritin, and transferrin saturation were also measured to evaluate body iron status. Significant correlation was observed between BMIC and T2 relaxation rate (1/T2) (r = 0.77; p < 0.001) in all patients with BMIC levels below 400 micrograms/ml, while BMIC was not correlated with T2 in patients with extremely high BMIC levels. MRI was considered to be inappropriate for quantitation of 1/T2 in patients with extremely high BMIC due to an extreme shortening of T2 relaxation time. These observations suggest that MRI may be a useful and noninvasive method for systemic quantitative determination of bone marrow iron.

Human alveolar macrophages synthesize endothelins by thrombin

Alveolar macrophages (AM) play pivotal roles in the defense mechanism and the regulation of inflammatory processes in the airways. Macrophages express receptors for thrombin on their surfaces, and thrombin induces the chemotaxis and the proliferation of macrophages. Thrombin acts on vascular endothelial cells to synthesize endothelin (ET)-1. AM have been known to express prepro ET-1 mRNA. Thus, we hypothesized that thrombin stimulates AM so as to synthesize ET. Surgically resected human lungs were irrigated by saline to remove intravascular blood, then saline was instilled into the bronchus, and the fluids were recovered. AM were separated by Percoll density centrifugation (density, 1.060 g/ml). AM were resuspended in culture medium without FCS in the presence or absence of thrombin. ET was synthesized by thrombin in a concentration-dependent manner, and the amounts of ET synthesized by thrombin (10 U/ml) were equivalent to those by LPS (10 microg/ml). Dexamethasone (10(-6)-10(-10) M), IL-4 (100 U/ml), and TGF-beta (10 ng/ml) significantly suppressed the ET synthesis by thrombin (p < 0.05). In contrast, 1,25-dihydroxyvitamin D3 (10(-8)-10(-10) M) enhanced the ET synthesis up to approximately 300%. The analysis using high pressure liquid chromatography revealed that AM-derived ET consists of ET-1, ET-2, and ET-3. Major constituents were ET-2 and ET-1, and the ratio of ET-2/ET-1 was 1.7 +/- 0.4 (mean +/- SE). These results indicate that thrombin is a potent agonist for AM to synthesize ET.

Neuronal nicotinic receptor operates slow Ca2+ mobilization at mouse muscle endplate

The contribution to neuromuscular functions by neuronal nicotinic acetylcholine receptor (nAChR) expressed at skeletal muscle endplate was investigated using intracellular Ca2+ measurements. A neuronal nAChR blocker, methyllycaconitine (MLA), depressed non-contractile Ca2+ mobilization without affecting muscle nAChR activity in nerve-stimulated mouse diaphragm muscle, after cholinesterase inhibition. Confocal imaging demonstrates that the MLA-sensitive Ca2+ mobilization also occurred at the endplate in single flexor digitorum brevis muscle cells as the slow component of two-phasic Ca2+ elevation after the prolonged nicotinic stimulation. A monoclonal antibody to alpha 1 subunit of muscle nAChR depressed the fast but not the slow component. Thus, muscle neuronal-nAChR can induce the localized rise of Ca2+ at the postjunctional sites.

Wortmannin enhances CPP32-like activity during neuronal differentiation of P19 embryonal carcinoma cells induced by retinoic acid

P19 EC cells undergoes apoptosis during neuronal differentiation induced by retinoic acid. Two CPP32-like proteases, CPP32 and Mch-3, are expressed in untreated and retinoic acid-treated P19 EC cells. CPP32-like activity is remarkably increased in apoptosis during neuronal differentiation of P19 EC cells. Inhibition of CPP32-like proteases prevents apoptosis, suggesting that activation of CPP32-like proteases play central roles in the apoptosis during neuronal differentiation of P19 EC cells. Wortmannin, PI-3K inhibitor, enhances the CPP32-like activity of the retinoic acid-treated P19 EC cells. PI-3K may be involved in the apoptosis during neuronal differentiation as negative regulator.

Specific expression of CPP32 in sensory neurons of mouse embryos and activation of CPP32 in the apoptosis induced by a withdrawal of NGF

We isolated mouse CPP32/apopain cDNA, a mammalian homologue most closely related to Ced-3 in C. elegans, and examined the involvement of CPP32 in the apoptosis of nervous system during development. CPP32 is specifically expressed in the trigeminal (V) ganglia, facio-acoustic (VII-VIII) ganglion complex, and dorsal root ganglia (DRGs) of mouse 10.5-day embryos. CPP32-like proteases are activated during apoptosis of DRG neurons induced by deprivation of NGF and serum. Ac-DEVD-CHO, an inhibitor for CPP32-like proteases, prevents apoptosis of DRG neurons, but Ac-YVAD-CHO, an inhibitor for ICE-like proteases, does not. These results suggest that CPP32 or CPP32-like proteases play a role as central mediator in the apoptosis of DRG neurons induced by lack of neurotrophin signals.