Negative regulation of multifunctional Ca2+/calmodulin-dependent protein kinases: physiological and pharmacological significance of protein phosphatases.

Multifunctional Ca2+/calmodulin-dependent protein kinases (CaMKs) play pivotal roles in intracellular Ca2+ signaling pathways. There is growing evidence that CaMKs are involved in the pathogenic mechanisms underlying various human diseases. In this review, we begin by briefly summarizing our knowledge of the involvement of CaMKs in the pathogenesis of various diseases suggested to be caused by the dysfunction/dysregulation or aberrant expression of CaMKs. It is widely known that the activities of CaMKs are strictly regulated by protein phosphorylation/dephosphorylation of specific phosphorylation sites. Since phosphorylation status is balanced by protein kinases and protein phosphatases, the mechanism of dephosphorylation/deactivation of CaMKs, corresponding to their 'switching off', is extremely important, as is the mechanism of phosphorylation/activation corresponding to their 'switching on'. Therefore, we focus on the regulation of multifunctional CaMKs by protein phosphatases. We summarize the current understanding of negative regulation of CaMKs by protein phosphatases. We also discuss the biochemical properties and physiological significance of a protein phosphatase that we designated as Ca2+/calmodulin-dependent protein kinase phosphatase (CaMKP), and those of its homologue CaMKP-N. Pharmacological applications of CaMKP inhibitors are also discussed. These compounds may be useful not only for exploring the physiological functions of CaMKP/CaMKP-N, but also as novel chemotherapies for various diseases.

Transplantation of newborn esophagus: an experimental study.

PURPOSE: The aim of this study was to see if allogeneic transplantation (Tx) of newborn esophagus can create viable esophageal tissue that may be used for treating long gap esophageal atresia. METHODS: Specimens of thoracic esophagus from newborn Brown-Norway rats, each were transplanted into a pouch created in the distal omentum of 5-week-old Lewis rats. In group I no immunosuppressant was used. FK-506 was used in group II (0.2 mg/kg), group III (0.6 mg/kg), and group IV (1.2 mg/kg) until a predetermined day of graft harvesting (1, 2, 3, 4, 5, 6, and 8 weeks after Tx). FK-506 was used for only 2 weeks in group V (0.6 mg/kg), and group VI (1.2mg/kg), and transplanted esophageal grafts were harvested 1, 2, 3, and 4 weeks after cessation of 2 weeks course FK-506. Syngeneic esophagus transplants were used as controls. All grafts were examined by H&E staining to assess graft viability and degree of rejection. RESULTS: Each successfully transplanted esophagus appeared macroscopically as a tube like mass. Each graft could be mobilized to the thoracic cavity, because of the long omental pedicle. Graft survival in the control group was 100%. Rejection was observed in all grafts from groups I, II, V, and VI. In contrast, grafts from groups III and IV showed only minimal or no rejection. There was no evidence of side effects of FK-506 in rats in groups III and IV, except significantly slower weight gain compared with controls (P <.05). CONCLUSIONS: FK-506 successfully prevented rejection, although immunologic tolerance was not achieved. These observations suggest that the authors' procedure has the potential to produce viable esophageal tissue that could be a new option for treating long gap esophageal atresia.

Pyloric stenosis: new histopathologic perspective using confocal laser scanning.

BACKGROUND/PURPOSE: Idiopathic hypertrophic pyloric stenosis (IHPS) is a common infantile disorder characterized by enlargement of the pylorus and gastric outlet obstruction. Its complete etiology is still not fully understood, but recent research has focussed on abnormalities of nerve distribution. The authors used confocal laser scanning microscopy to perform 3-dimensional studies of pylorus biopsy specimens taken from cases of IHPS and present their findings. METHODS: Pylorus biopsy specimens obtained at pyloromyotomy from 6 infants with IHPS were studied using confocal microscopy and compared with 6 control pylorus biopsy specimens from patients without gastrointestinal disease. Biopsy specimens were pretreated to enhance nerve expression by using protein gene product 9.5 (PGP9.5) polyclonal antibody to identify enteric nerve system fibers. Double staining immunofluorescence was used to detect alpha smooth muscle actin (SMA), a smooth muscle marker. RESULTS: Control pylorus biopsy specimens showed many thin PGP9.5-positive nerve fibers in the circular and longitudinal muscle layers that communicated with each other to create a 3-dimensional meshlike network. Muscle cells stained by alpha SMA antibody were thin. In contrast, muscle cells from IHPS patients were fat and round. The PGP9.5 staining nerve fibers from IHPS patients formed numerous, thick, and contorted bundles that did not communicate. CONCLUSIONS: By using confocal laser microscopy the authors were able to identify abnormally thick contorted nerve bundles in the pyloric muscle layers of infants with IHPS. These anormal nerve bundles have not been described previously because of the limitations of 2-dimensional microscopy. The authors suspect that the etiology of IHPS may be related to these abnormal fibers.

Intestinal neuronal dysplasia-like pathology in Ncx/Hox11L.1 gene-deficient mice.

BACKGROUND/PURPOSE: Ncx/Hox11L.1-deficient (Ncx-/-) mice specifically created by the authors had mega-ileo-ceco-colon (mega-ICC) with a caliber change in the proximal colon. The authors studied the nerve distribution in the bowel of these Ncx-/- mice to determine the cause of their bowel dysmotility. METHODS: Four-week-old Ncx-/- mice (n = 10; 5 with mega-ICC, 5 without mega-ICC) were killed and the bowel harvested. Half of each specimen was snap frozen for AchE and NADPH-diaphorase histochemistry, and the other half were fixed with 10% formalin for H&E staining and immunohistochemistry using PGP9.5 antibody (a marker for neurons), C-kit antibody (a marker for intestinal pacemaker cells), and stem cell factor antibody (a marker for C-kit ligand). Age-matched wild-type normal mice (n = 5) served as controls. RESULTS: In the ileum, cecum, and proximal colon from all Ncx-/- mice (irrespective of the association of mega-ICC), typical findings of human intestinal neuronal dysplasia (IND) ie, obvious hyperganglionosis in neuronal plexuses on PGP9.5 immunohistochemistry, ectopic ganglia in the mucosal and muscular layers on AchE histochemistry, and ghostlike ganglia on NADPH-diaphorase histochemistry were found. Likewise, in normal caliber distal colon from these mice, the distribution of ganglion cells, C-kit, and stem cell factor was normal. In control specimens, there was no ectopic ganglia or hyperganglionosis. CONCLUSIONS: These findings suggest that the Ncx/Hox11L.1 gene is required for the proper innervation of the enteric nervous system in mice, and our deficient strain may be useful as a model for studying IND in humans.

Apoptosis of Neuro2a cells induced by lysosphingolipids with naturally occurring stereochemical configurations.

Lysosphingolipids, which lack the fatty acid moiety of sphingolipids, are known to be accumulated in some variants of sphingolipid storage diseases. Here, we report that lysosphingolipids with naturally occurring stereochemical configurations induce apoptosis in mouse neuroblastoma Neuro2a cells. The intracellular dehydrogenase activity and [3H]thymidine incorporation of Neuro2a cells were strongly suppressed by the addition of lysosphingolipids in a dose-dependent manner, whereas the parental sphingolipids had no effect. Intranucleosomal DNA fragmentation, chromatin condensation, and phosphatidylserine externalization, which are typical features of apoptosis, were observed when the cells were cultured with 40-80 microM of lysosphingolipids for 24-48 h in the presence of 5% fetal calf serum. Activation of caspase-3-like enzyme occurred after addition of lysosphingolipids followed by incubation at 37 degrees C for 24 h. The addition of an inhibitor of caspases, ZVAD-fmk, to the Neuro2a cell culture completely inhibited the elevation of caspase-3 activity but not the DNA fragmentation. These results may indicate that a caspase-3 independent signaling pathway is involved in the lysosphingolipid-induced apoptosis and suggest that accumulation of lysosphingolipids, but not parental sphingolipids, triggers the apoptotic cascade in neuronal cells of patients with sphingolipidoses.

Bladder transplantation in rats using FK-506.

PURPOSE: We created viable bladder tissue by transplantation with immunosuppression. MATERIALS AND METHODS: For bladder transplantation the bladder of newborn Brown-Norway rats was excised and each was transplanted into a pouch created in the distal omentum of a 5-week-old Lewis rat. In 15 group 1 rats no immunosuppressive agent was used. In 20 group 2 rats 0.6 mg./kg. FK-506 daily were given intramuscularly until a predetermined day of harvest. Recipient rats were sacrificed on day 3, 5, 7 or 14 after bladder transplantation, and the bladder grafts were harvested and formalin fixed. Hematoxylin and eosin staining was done to examine bladder graft survival and the degree of rejection, and immunohistochemical testing was performed for assessing the vesical nervous system. In 5 rats in the control group bladder augmentation was performed by anastomosing the bladder graft to the native bladder. Each augmented bladder was harvested 21 days later for histopathological assessment. RESULTS: Overall bladder graft survival was 96.4%. Each successfully transplanted bladder graft appeared macroscopically as a thin walled cyst. In group 1 all bladder grafts showed rejection with cellular infiltration. In group 2 there was mild rejection in 5 rats and no evidence of rejection in the remaining 15. All group 2 bladder grafts had intact nerve distribution. Bladder augmentation was successful in all 5 cases and the mucosa was normal throughout each augmented bladder. CONCLUSION: Because FK-506 successfully prevents rejection, our technique would appear to have the potential for creating viable bladder tissue that may be used for bladder augmentation in cases of vesical exstrophy or neurogenic bladder.

Are stable postoperative biliary atresia patients really stable?

Transforming growth factor-beta 1 (TGF beta-1) is an important mediator of liver-cell proliferation and replication that is implicated in hepatic fibrosis (HF). Hepatic stellate cells (HSC) are activated by TGF beta-1 and are the main precursor cells involved in fibrogenesis. The correlation between serum TGF beta-1, activated HSC in liver-biopsy specimens, and liver biochemistry was investigated to determine the value of TGF beta-1 as an indicator of clinical status in postoperative biliary atresia (BA) patients. Thirty-two postoperative BA patients (mean age 11.2 +/- 2.8 years) and 13 normal controls (mean age 10.3 +/- 3.7 years) were studied. Based on average liver function test (LFT) results over a 3-month period immediately prior to this study, the BA patients were divided into group I (anicteric, normal LFT; n = 10); group II (anicteric, elevated liver transaminases; n = 12), and group III (jaundiced end-stage liver fibrosis awaiting liver transplantation; n = 10). Serum TGF beta-1 was determined using ELISA. Liver-biopsy specimens were examined with antibody against TGF beta-1 and alpha-smooth muscle actin (SMA) antibody for detection of activated HSC. Serum TGF beta-1 was significantly higher in groups I (11.4 +/- 3.7 ng/ml; P < 0.01) and II (23.3 +/- 11.3 ng/ml; P < 0.001) than in group III (3.0 +/- 1.5 ng/ml) and controls (4.5 +/- 2.5 ng/ml) despite normal LFT in group I. The 3 subjects with the highest serum TGF beta-1 in group II had bile lakes. Biopsies from groups I and II were strongly positive for TGF beta-1 in hepatocytes and Kupffer cells and for activated HSC detected by SMA compared with group III and controls. Because serum TGF beta-1 and activated HSC are only present during active fibrosis, we conclude that there is progressive fibrogenesis even in seemingly normal postoperative BA patients. In particular, bile lakes should be regarded as a key sign of progressive HF, the presence of which should be regarded with extreme caution. We suggest that serum TGF beta-1 could be used as an accurate indicator of progressive fibrogenesis in postoperative BA patients.

Transplantation of infantile bladder in rats: an alternative procedure for bladder augmentation.

BACKGROUND: Our purpose was to evaluate whether bladder transplantation (BTx) can be used for bladder augmentation (BA). METHODS: Bladders from infantile Brown-Norway rats (less than 21 days old) were excised and each transplanted into a pouch created in the distal omentum of a 6-week-old Lewis rat (fully allogeneic BTx). No immunosuppressant was used in group I (n=12). Intramuscular FK506 was used daily from the day of BTx in group II (n=16; 0.2 mg/kg), group III (n=22; 0.6 mg/kg), and group IV (n=16; 1.2 mg/kg) until harvesting 3, 4, 5, or 6 weeks after BTx. FK506 was used for only 2 weeks in group V (n=12; 0.6 mg/kg/day) and group VI (n=12; 1.2 mg/kg/day). Syngeneic bladder transplants acted as controls (n=16). Hematoxylin and eosin staining was used to examine all grafts. In six rats from group III, BA was performed by anastomosing the graft to the recipient bladder 10 days after BTx. RESULTS: Each successfully transplanted graft appeared macroscopically as a thin-walled cyst. Rejection was seen in all grafts from groups I, II, V, and VI, and was minimal or absent in groups III and IV. On medium to long-term follow-up the only side effect of FK506 observed was reduced weight gain. Graft survival in the control group was 100%. BA was successful in all six cases, and the mucosa was normal throughout each augmented bladder. CONCLUSIONS: This is the first report of the successful transplantation of infantile tissue without vascular anastomosis. Because of the efficient, safe immunosuppression possible with FK506, our BTx technique could find clinical application for creating viable vesical tissue that could be used for BA.

Tubed latissimus dorsi musculocutaneous flaps for esophageal replacement in puppies: long-term follow-up.

PURPOSE: The aim of this study was to show that a tubed latissimus dorsi musculocutaneous flap (tubed LDMCF) may be useful for treating circumferential esophageal defects. METHODS: A segment of esophagus 3 vertebrae long was excised through a right thoracotomy in each of 6 puppies, and a tubed LDMCF was interposed between the cut ends of esophagus. The puppies were sacrificed after a mean follow-up period of 6.6 years. The tubed LDMCF was examined histologically. Functional integrity was assessed using barium meal and endoscopy before sacrifice. RESULTS: All puppies survived and grew normally on a normal diet, although 4 vomited occasionally. There was smooth passage of barium through the tubed LDMCF without stenosis, although endoscopy showed regrowth of hair. Histologically, no metaplasia, dysplasia, or malignancy was observed in any tubed LDMCF. CONCLUSIONS: The tubed LDMCF is technically safe, obviates the necessity for laparotomy, and long-term follow-up would suggest that it is histologically stable. Thus, it could become an alternative procedure for bridging esophageal defects.

Cloning and expression of gene encoding a novel endoglycoceramidase of Rhodococcus sp. strain C9.

Endoglycoceramidase (EGCase) is an enzyme capable of cleaving the glycosidic linkage between oligosaccharides and ceramides of various glycosphingolipids. We previously reported that the Asn-Glu-Pro (NEP) sequence is part of the active site of EGCase of Rhodococcus sp. strain M-777. This paper describes the molecular cloning of a new EGCase gene utilizing the NEP sequence from the genomic library of Rhodococcus sp. strain C9, which was clearly distinguishable from M-777 by 16S rDNA analysis. C9 EGCase possessed an open reading frame of 1,446 bp encoding 482 amino acids, and showed 78% and 76% identity to M-777 EGCase II at the nucleotide and amino acid levels, respectively. Interestingly, C9 EGCase showed the different specificity to the M-777 enzyme: it hydrolyzed b-series gangliotetraosylceramides more slowly than the M-777 enzyme, whereas both enzymes hydrolyzed a-series gangliosides and neutral glycosphingolipids to the same extent.

Idiopathic gastric perforation in neonates and abnormal distribution of intestinal pacemaker cells.

BACKGROUND/PURPOSE: The etiology of idiopathic gastric perforation (IGP) in neonates is unclear. Interstitial cells of Cajal (ICC) express tyrosine kinase receptor C-kit, and act as gastrointestinal pacemaker cells. Stem cell factor (SCF) is a C-kit ligand and plays an important role in immune system homeostasis in the gastrointestinal tract. The authors hypothesized that abnormal distribution of ICC or SCF in the gastric wall (ie, abnormal motility or impaired immunity) could predispose the stomach to IGP. METHODS: Stomachs obtained at postmortem from neonates who died of IGP (n = 7) and other causes (control group; n = 10) were used. Biopsy sections were taken at random from various sites in the stomach, including macroscopically intact areas, and labeled immunohistochemically using antibodies to C-kit(a marker for ICC) and SCF. RESULTS: In all control specimens, ICC were present between the muscle layers and around the myenteric plexuses of the stomach wall. In contrast, ICC were absent in all biopsy sections from 3 of the 7 IGP stomachs. In the remaining 4 IGP stomachs, there were fewer ICC in the muscle layers compared with controls, and ICC were absent around the myenteric plexuses. The distribution of SCF immunoreactivity in IGP and control specimens was similar. CONCLUSION: The findings suggest that a lack of ICC (ie, gastric hypomotility) may be implicated in the etiology of IGP in neonates.

Lack of C-KIT+ mast cells and the development of idiopathic gastric perforation in neonates.

BACKGROUND/PURPOSE: The proto-oncogene c-kit encodes a receptor tyrosine kinase C-KIT. W/Wv mice, which are devoid of C-KIT+ mast cells as a result of mutations in the c-kit gene, develop spontaneous gastric ulceration or perforation after day 7 of life at a high frequency, whereas normal litter mates do not. The authors hypothesized that a lack of C-KIT+ mast cells may be implicated in the development of idiopathic gastric perforation (GP) in neonates. METHODS: Postmortem gastric wall specimens were taken from neonates who died of GP (idiopathic, n = 6; secondary, n = 4), and other causes (controls, n = 6). Specimens were taken at random from various sites in the stomach and labeled with antibody to C-KIT. The number of C-KIT+ mast cells from five random fields per specimen were compared under light microscopy (200x). RESULTS: Overall, the number of C-KIT+ mast cells was significantly lower in gastric wall specimens from cases of idiopathic GP when compared with controls or cases of secondary GP irrespective of the sites of sampling (P<.01, analysis of variance test) with the distribution of cells being uniform and unique for each stomach. CONCLUSION: A lack of C-KIT+ mast cells may underlie the development of idiopathic GP in neonates.

Necrotizing enterocolitis and C-KIT.

BACKGROUND/PURPOSE: In the gut, C-KIT is important for immune system homeostasis, and C-KIT+ cells are known to increase during inflammation. Recently the authors identified that spontaneous intestinal mucosal erosion develops in C-KIT-depleted W/Wv mice after day 14 of life at a high frequency, whereas genotypically normal litter mates do not. The authors hypothesized that a lack of C-KIT may be implicated in the development of necrotizing enterocolitis (NEC). METHODS: Bowel specimens were taken during surgery or postmortem from nine cases of NEC (mean gestational age, 32.0 weeks), six age-matched cases of enteritis, and 10 age-matched controls. Specimens were formalin fixed, paraffin embedded, and labeled with antibody to C-KIT. The number of C-KIT+ cells from five random fields per specimen were compared under light microscopy (200x). Results were expressed as the mean +/- SD and compared using the analysis of variance (ANOVA) test. RESULTS: In enteritis, the number of C-KIT+ cells in the lamina propria and submucosa was significantly higher than in controls (P<.01) indicative of their involvement in inflammation. However, in NEC, the number of C-KIT+ cells in the lamina propria and submucosa was significantly lower than in controls (P<.05) despite histological evidence of inflammation. CONCLUSION: A lack of C-KIT+ cells may exert a causal influence on the development of NEC.

Preparation of a naturally occurring D-erythro-(2S, 3R)-sphingosylphosphocholine using Shewanella alga NS-589.

Sphingosylphosphocholine, an N-deacylated derivative of sphingomyelin, has been found to be involved in many cellular events. This paper describes a new method for preparation of a D-erythro-sphingosylphosphocholine, which is naturally occurring but difficult to prepare by chemical methods, using marine bacteria as a biocatalyst. When cultured with Shewanella alga NS-589 in synthetic medium, sphingomyelin was found to be efficiently converted by sphingomyelin deacylase to sphingosylphosphocholine. Sphingosylphosphocholine was purified with a high yield from the culture supernatant and identified to be a D-erythro-(2S,3R)-isomer containing d18:1 sphingenine as a long-chain base by fast atom bombardment mass spectrometry and NMR analyses.

Apoptosis as a possible cause of wall thinning in end-stage hypertrophic cardiomyopathy.

A 15-year-old boy with hypertrophic cardiomyopathy died of congestive heart failure with progressive left ventricular wall thinning with poor systolic function. Microscopic examination revealed patchy fibrosis in the ventricular myocardium with wall thinning, and immunohistochemical evaluation of apoptosis showed apoptotic cells and bodies in the destroyed myocytes along the border between the fibrotic area and myofibril.

A lack of intestinal pacemaker (c-kit) in aganglionic bowel of patients with Hirschsprung's disease.

Recent experimental studies in mice have shown that the proto-oncogene c-kit plays a key role in the development of a component of the pacemaker system that is required for generation of autonomic gut motility. These studies further suggest that interaction of the c-kit receptor and its ligand (stem cell factor, SCF) is critical for the development of the enteric nervous system. The authors investigated the presence of c-kit-positive (c-kit+) cells as well as the expression of SCF in bowel from 12 patients with Hirschsprung's disease (HD), 4 patients with total colonic aganglionosis (TCA), 2 patients with extensive aganglionosis (EA) and 14 controls. Our methods involved the use of immunohistochemistry with antihuman c-kit sera and antihuman SCF sera. A few c-kit+ cells were found in the muscle layers of aganglionic bowels from HD, TCA and EA, in contrast to many c-kit+ cells in ganglionic bowel segments from control, HD, and TCA patients. Expression of SCF was identified in the muscle layers as well as in myenteric plexus of ganglionic bowel, in contrast to its absence in the muscle layers of aganglionic bowel specimens. A lack of c-kit and SCF might be of significance for autonomic gut dysmotility in aganglionic bowel segments of patients with HD and allied disorders such as chronic idiopathic intestinal pseudo-obstruction.

Apoptosis in acute and chronic myocarditis.

Programmed cell death or apoptosis plays a major role in the modification of morphologic and functional maturity in various normal organ systems. However, it is also related to certain diseases. We conducted a pathological study of the apoptosis of cardiomyocytes in six cases with myocarditis (three of acute myocarditis and three of chronic or persistent myocarditis) using histochemical methods. In normal hearts obtained from autopsy cases, apoptosis was seen in endocardial cells. There was no apoptosis in myocardial cells, except for a few in myocytes with two nuclei. In myocarditis, although the myocytes of all cases with acute myocarditis did not show apoptosis, one of the three cases with chronic or persistent myocarditis showed many apoptotic myocytes. Apoptosis may be one of the mechanisms causing myocyte damage in myocarditis.

Immunohistochemical expression of proliferating cell nuclear antigen (PCNA) in intracranial glioma and meningioma.

BACKGROUND: Immunohistochemical study of proliferating cells in normal or neoplastic tissues has its advantages over other methods in understanding cell kinetic information. Proliferating cell nuclear antigen (PCNA) immunolocalization in paraffin section was reported as an index for cellular proliferation and well-correlated with the histopathological grading of certain systemic malignancies. METHODS: By using immunohistochemical staining of PCNA on formalin-fixed, paraffin-embedded sections, the anti-PCNA monoclonal antibody (PC10) staining scores were counted in 32 intracranial gliomas and 32 intracranial meningiomas. RESULTS: The PC10 scores ranged from 7.8% to 24.1% (m = 15.7 +/- 4.5%) in 12 anaplastic astrocytomas, and from 15.1% to 51.3% (m = 38.4 +/- 11.7%) in 9 glioblastomas. The difference in between was significant. The mean PC10 scores of benign meningiomas, malignant meningiomas, and hemangiopericytomas were 13.8%, 50.2%, and 50.8% respectively. The difference of PC10 scores was also significant between benign and malignant meningioma, as well as between benign meningioma and hemangiopericytoma. CONCLUSIONS: The PC10 scores have a good correlation with the histopathological grading of both intracranial glioma and meningioma.

Abnormal origin of bilateral ophthalmic arteries. Case report.

The case of a 64-year-old woman with multiple intracranial aneurysms and abnormal ophthalmic arteries arising from the bifurcation of the internal carotid artery is described. It is believed that this type of anomaly of the ophthalmic artery has not previously been reported. The neuroradiological and operative findings of this case are presented.