The method of mouse embryoid body establishment affects structure and developmental gene expression

To investigate formation of the three primary germ layers in mouse embryoid bodies (EBs), we observed changes in structure and gene expression over a 7-day culture period. We compared these changes using two methods for EB formation: hanging drop (HD) and static suspension culture (SSC). Light microscopy showed that a stratified columnar epithelial layer developed on the surface of EBs formed using the HD method. From Day 3 in culture, ultrastructural changes occurred in the aligned cellular membranes. Condensation of actin filaments was followed by formation of complicated adherent junctions and dilatation of intercellular canaliculi containing well-developed microvilli. These changes were more marked in EBs formed by the HD method than the SSC method. On Day 5 of culture, Brachyury gene expression, a marker for mesoderm formation, was detected only with the HD method. Nestin, an ectoderm marker, and Foxa2, an endoderm marker, were expressed with both methods. These results suggest that in EBs formed with the HD method, actin formation and Brachyury gene expression mark the transition from two to three primary germ layers. Additionally, the HD method promotes more rapid and complete development of mouse EBs than does the SSC method. While the SSC method is simple and easy to use, it needs improvement to form more complete EBs.

Dextran sulfate sodium-induced acute colonic inflammation in angiotensin II type 1a receptor deficient mice

OBJECTIVE

Angiotensin II (Ang II) receptor blockers have been reported to contribute to cytoprotective effects in various organs. However, the role of renin-angiotensin system (RAS) in modulation of the inflammatory bowel disease (IBD) remains unclear. In this study we assessed the role of angiotensin II type 1a (AT1a) receptor on the outcome of dextran sulfate sodium (DSS)-induced acute colitis by employing AT1a receptor deficient mice.

MATERIALS AND METHODS

The acute colitis was induced in wild type (WT) and AT1a receptor deficient mice by giving orally 3% DSS in drinking water for 7 days.

RESULTS

Induction of DSS colitis resulted in up-regulation of Ang II and AT1a receptor in the colonic mucosa of WT mice. In parallel, loss of body weight, an increase in disease activity index (DAI), and the shortening of colon were found in DSS-challenged WT mice. In addition, an increase in thiobarbituric acid (TBA)-reactive substances and myeloperoxidase (MPO) activity, along with the up-regulation of tumor necrosis factor (TNF)-alpha were detected in the colonic mucosa of DSS-challenged WT mice. The endpoints mentioned above were significantly ameliorated in DSS-challenged AT1a receptor deficient mice.

CONCLUSIONS

RAS is involved in the pathophysiology of DSS-induced colitis and AT1a receptor may be a novel therapeutic target for the treatment of IBD.

Effect of motion imagery to counter rest-induced suppression of F-wave as a measure of anterior horn cell excitability

OBJECTIVE

To test if motor imagery prevents the rest-induced suppression of anterior horn cell excitability.

METHODS

Ten healthy subjects underwent two separate experiments, each consisting of stimulating the median nerve 100 times and recording F-waves from abductor pollicis brevis (APB) in three consecutive sessions: (1) after muscle exercise to standardize the baseline, (2) after immobilization of APB for 3h and (3) after muscle exercise to check recovery. We instructed the subject to volitionally relax APB in experiment 1 (relaxation task), and to periodically simulate thumb abduction without actual movement in experiment 2 (imagery task).

RESULTS

F-wave persistence and amplitude declined after relaxation task and recovered quickly after exercise, but changed little with imagery task. F-wave latencies showed no change when analyzed individually. The frequency distribution of collective F-waves recorded from all subjects remained the same after relaxation task, but showed a shift toward longer latencies after imagery task.

CONCLUSIONS

Mental imagery without overt motor output suffices to counter the effect of sustained volitional muscle relaxation, which would, otherwise, cause a reversible reduction in anterior horn cell excitability.

SIGNIFICANCE

This finding documents the importance of central drive for spinal excitability, which affects F-wave studies of a paretic muscle.

Changes of Urinary 8-Hydroxydeoxyguanosine Levels during a Two-Day Ultramarathon Race Period in Japanese Non-Professional Runners

Using the urinary 8-hydroxydeoxyguanosine (8-OHdG) concentration, effects of participation in a two-day ultramarathon race period on oxidative DNA damage were investigated in Japanese nonprofessional runners. Before the first day (baseline), after the first day (mid-race) of 40-km running, and after the second day (post-race) of 90 km running, biomaterials were successfully sampled from 95 participants (males, 79; females, 16) who completed the full race. We analyzed urine for 8-OHdG and blood for aspartate aminotransferase (AST), creatine phosphokinase (CPK) and myoglobin, and evaluated fluctuation in the values at three sampling time points. Adjusted baseline urinary 8-OHdG levels (microg/g creatinine) (mean +/- standard deviation) showed no significant differences between males and females, at 2.85 +/- 1.17 and 3.04 +/- 1.56, respectively. In males, mid-race urinary 8-OHdG levels rose to 3.29 +/- 1.15 (p < 0.01), but then returned to 2.73 +/- 1.16 at the post-race time point (p < 0.01). In females, a similar increase to 3.32 +/- 1.47 and subsequent decline to 2.80 +/- 1.47 were noted. In contrast, AST, CPK and myoglobin were increased at both mid- and post-time points and particularly the latter, independent of the sex. Extreme prolonged exercise in a two-day ultramarathon race period causes oxidative DNA damage but antioxidant repair systems are apparently induced to protect against oxidative DNA stress with physical exercise.

The reduction of proprioceptors in the mesencephalic trigeminal tract nucleus after neonatal masseteric nerve transection; effect of brain-derived neurotrophic factor

The effect of neonatal masseteric nerve transection on primary proprioceptors was examined in the mesencephalic trigeminal tract nucleus (Mes5) of the rat. At 72 h to 21 days after the injury, the number of Mes5 neurons decreased on the side ipsilateral to the transection. The means+/-SD of percentage proportion of ipsilateral/contralateral neurons at 72 h and 21 days were 69.9+/-7.5% and 58.2+/-14.6%, respectively. The application of brain-derived neurotrophic factor to the proximal stump of the masseteric nerve delayed the loss of Mes5 neurons at 72 h after the injury; the mean numbers+/-SD of ipsilateral and contralateral Mes5 neurons in injured animals with BDNF application was 553.6+/-61.9 and 558.4+/-55.3, respectively. Saline application had no effect on the injury-induced loss of Mes5 neurons; i.e., the mean numbers+/-SD of ipsilateral and contralateral Mes5 neurons were 367.3+/-72.5 and 543+/-33.5, respectively. These findings indicate that trigeminal primary proprioceptors are sensitive to the neonatal injury. The survival of proprioceptors during early postnatal period is probably dependent upon brain-derived neurotrophic factor in the trigeminal nervous system.

Brain-derived neurotrophic factor-immunoreactive neurons in the rat vagal and glossopharyngeal sensory ganglia; co-expression with other neurochemical substances

Immunohistochemistry for brain-derived neurotrophic factor (BDNF) was performed on the rat vagal and glossopharyngeal sensory ganglia. In the jugular, petrosal and nodose ganglia, 56.1+/-5.5%, 52.4+/-9.4% and 80.0+/-3.0% of sensory neurons, respectively, were immunoreactive for BDNF. These neurons were small- to medium-sized and observed throughout the ganglia. In the solitary tract nucleus, the neuropil showed BDNF immunoreactivity. A double immunofluorescence method demonstrated that BDNF-immunoreactive neurons were also immunoreactive for calcitonin gene-related peptide (CGRP), P2X3 receptor, the capsaicin receptor (VR1) or vanilloid receptor 1-like receptor (VRL-1) in the jugular (CGRP, 43.5%; P2X3 receptor, 51.1%; VR1, 71.7%; VRL-1, 0.5%), petrosal (CGRP, 33.2%; P2X3 receptor, 58.4%; VR1, 54.2%; VRL-1, 23.3%) and nodose ganglia (CGRP, 1.8%; P2X3 receptor, 49.1%; VR1, 70.7%; VRL-1, 11.5%). The co-expression with tyrosine hydroxylase was also detected in the petrosal (2.9%) and nodose ganglia (2.2%). However, BDNF-immunoreactive neurons were devoid of parvalbumin in these ganglia. The present findings suggest that BDNF-containing vagal and glossopharyngeal sensory neurons have nociceptive and chemoreceptive functions.

Dystonin deficiency reduces taste buds and fungiform papillae in the anterior part of the tongue

The anterior part of the tongue was examined in wild type and dystonia musculorum mice to assess the effect of dystonin loss on fungiform papillae. In the mutant mouse, the density of fungiform papillae and their taste buds was severely decreased when compared to wild type littermates (papilla, 67% reduction; taste bud, 77% reduction). The mutation also reduced the size of these papillae (17% reduction) and taste buds (29% reduction). In addition, immunohistochemical analysis demonstrated that the dystonin mutation reduced the number of PGP 9.5 and calbindin D28k-containing nerve fibers in fungiform papillae. These data together suggest that dystonin is required for the innervation and development of fungiform papillae and taste buds.

A new technique for endoscopic submucosal dissection for early gastric cancer using an external grasping forceps

BACKGROUND AND STUDY AIMS

Endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) has improved the success rate of en-bloc resection. We report here on a new technique using an external grasping forceps.

PATIENTS AND METHODS

A total of 25 patients with suitable EGCs over 10 mm in diameter located in the gastric body were enrolled. After submucosal injection followed by circumcision of the lesion with a needle-knife, an external grasping forceps was introduced with the help of a second grasping forceps and anchored at the distal margin of the lesion. With gentle oral traction applied with this forceps, the lesion was dissected endoscopically in retroversion from the aboral side.

RESULTS

The mean lesion size was 15.0 mm (range 10 - 25 mm). Using the technique described, all lesions could be resected en bloc with free margins. The mean procedure time was 45 min (range 30 - 80 minutes). No significant bleeding requiring blood transfusion or perforation occurred.

CONCLUSIONS

This technical modification may simplify and shorten the gastric ESD procedure, except for lesions in distal locations, without compromising the efficacy.

Evidence that TNF-TNFR1-TRADD-TRAF2-RIP-TAK1-IKK pathway mediates constitutive NF-κB activation and proliferation in human head and neck squamous cell carcinoma

Constitutively activated nuclear factor-kappaB (NF-kappaB) has been associated with a variety of aggressive tumor types, including head and neck squamous cell carcinoma (HNSCC); however, the mechanism of its activation is not fully understood. Therefore, we investigated the molecular pathway that mediates constitutive activation of NF-kappaB in a series of HNSCC cell lines. We confirmed that NF-kappaB was constitutively active in all HNSCC cell lines (FaDu, LICR-LON-HN5 and SCC4) examined as indicated by DNA binding, immunocytochemical localization of p65, by NF-kappaB-dependent reporter gene expression and its inhibition by dominant-negative (DN)-inhibitory subunit of NF-kappaB (IkappaBalpha), the natural inhibitor of NF-kappaB. Constitutive NF-kappaB activation in HNSCC was found to be due to constitutive activation of IkappaBalpha kinase (IKK); and this correlated with constitutive expression of phosphorylated forms of IkappaBalpha and p65 proteins. All HNSCC showed the expression of p50, p52, p100 and receptor-interacting protein; all linked with NF-kappaB activation. The expression of constitutively active NF-kappaB in HNSCC is mediated through the tumor necrosis factor (TNF) signaling pathway, as NF-kappaB reporter activity was inhibited by DN-TNF receptor-associated death domain (TRADD), DN-TNF receptor-associated factor (TRAF)2, DN-receptor-interacting protein (RIP), DN-transforming growth factor-beta-activated kinase 1 (TAK1), DN-kappa-Ras, DN-AKT and DN-IKK but not by DN-TRAF5 or DN-TRAF6. Constitutive NF-kappaB activation was also associated with the autocrine expression of TNF, TNF receptors and receptor-activator of NF-kappaB and its ligand in HNSCC cells but not interleukin (IL)-1beta. All HNSCC cell lines expressed IL-6, a NF-kappaB-regulated gene product. Furthermore, treatment of HNSCC cells with anti-TNF antibody downregulated constitutively active NF-kappaB, and this was associated with inhibition of IL-6 expression and cell proliferation. Our results clearly demonstrate that constitutive activation of NF-kappaB is mediated through the TRADD-TRAF2-RIP-TAK1-IKK pathway, making TNF a novel target in the treatment of head and neck cancer.

Genetic deletion of PKR abrogates TNF-induced activation of IkappaBalpha kinase, JNK, Akt and cell proliferation but potentiates p44/p42 MAPK and p38 MAPK activation

Double-stranded RNA-dependent protein kinase (PKR), a ubiquitously expressed serine/threonine kinase, has been implicated in the regulation or modulation of cell growth through multiple signaling pathways, but how PKR regulates tumor necrosis factor (TNF)-induced signaling pathways is poorly understood. In the present study, we used fibroblasts derived from PKR gene-deleted mice to investigate the role of PKR in TNF-induced activation of nuclear factor-kappaB (NF-kappaB), mitogen-activated protein kinases (MAPKs) and growth modulation. We found that in wild-type mouse embryonic fibroblast (MEF), TNF induced NF-kappaB activation as measured by DNA binding but deletion of PKR abolished this activation. This inhibition was associated with suppression of inhibitory subunit of NF-kappaB (IkappaB)alpha kinase (IKK) activation, IkappaBalpha phosphorylation and degradation, p65 phosphorylation and nuclear translocation, and NF-kappaB-dependent reporter gene transcription. TNF-induced Akt activation needed for IKK activation was also abolished by deletion of PKR. NF-kappaB activation was diminished in PKR-deleted cells transfected with TNF receptor (TNFR) 1, TNFR-associated death domain and TRAF2 plasmids; NF-kappaB activated by NF-kappaB-inducing kinase, IKK or p65, however, was minimally affected. Among the MAPKs, it was interesting that whereas TNF-induced c-Jun N-terminal kinase (JNK) activation was abolished, activation of p44/p42 MAPK and p38 MAPK was potentiated in PKR-deleted cells. TNF induced the expression of NF-kappaB-regulated gene products cyclin D1, c-Myc, matrix metalloproteinase-9, survivin, X-linked inhibitor-of-apoptosis protein (IAP), IAP1, Bcl-x(L), A1/Bfl-1 and Fas-associated death domain protein-like IL-1beta-converting enzyme-inhibitory protein in wild-type MEF but not in PKR-/- cells. Similarly, TNF induced the proliferation of wild-type cells, but this proliferation was completely suppressed in PKR-deleted cells. Overall, our results indicate that PKR differentially regulates TNF signaling; IKK, Akt and JNK were positively regulated, whereas p44/p42 MAPK and p38 MAPK were negatively regulated.

ASIC3-immunoreactive neurons in the rat vagal and glossopharyngeal sensory ganglia

ASIC3-immunoreactivity (ir) was examined in the rat vagal and glossopharyngeal sensory ganglia. In the jugular, petrosal and nodose ganglia, 24.8%, 30.8% and 20.6% of sensory neurons, respectively, were immunoreactive for ASIC3. These neurons were observed throughout the ganglia. A double immunofluorescence method demonstrated that many ASIC3-immunoreactive (ir) neurons co-expressed calcitonin gene-related peptide (CGRP)- or vanilloid receptor subtype 1 (VRL-1)-ir in the jugular (CGRP, 77.8%; VRL-1, 28.0%) and petrosal ganglia (CGRP, 61.7%; VRL-1, 21.5%). In the nodose ganglion, however, such neurons were relatively rare (CGRP, 6.3%; VRL-1, 0.4%). ASIC3-ir neurons were mostly devoid of tyrosine hydroxylase in these ganglia. However, some ASIC3-ir neurons co-expressed calbindin D-28k in the petrosal (5.5%) and nodose ganglia (3.8%). These findings may suggest that ASIC3-containing neurons have a wide variety of sensory modalities in the vagal and glossopharyngeal sensory ganglia.

Brain-derived neurotrophic factor-immunoreactive primary sensory neurons in the rat trigeminal ganglion and trigeminal sensory nuclei

Immunohistochemistry for brain-derived neurotrophic factor (BDNF) was performed on the rat trigeminal ganglion (TG). The immunoreactivity (IR) was detected in 46% of TG neurons. These neurons were mostly small- or medium-sized (range, 149.7-1246.3 microm2; mean +/- SD = 373.4 +/- 151.6 microm2). A double immunofluorescence method also revealed that 54% of BDNF-immunoreactive (IR) neurons were immunoreactive for calcitonin-gene-related peptide. In addition, 93% of BDNF-IR TG neurons contained vanilloid receptor subtype 1. However, the co-expression of BDNF and vanilloid receptor 1-like receptor was very rare (less than 1%). In the trigeminal sensory nuclei, laminae II of the medullary dorsal horn was abundant in presumed BDNF-IR axon terminals. Such profiles were also detected in the dorsolateral part of the subnucleus oralis. The retrograde tracing and immunohistochemical methods demonstrated that BDNF-IR was common among cutaneous TG neurons (47%) but not tooth pulp TG neurons (13%). The present study indicates that BDNF-IR TG neurons have unmyelinated axons and project to the superficial medullary dorsal horn. It is likely that BDNF-containing neurons in both the trigeminal and spinal sensory systems have similarities in morphology and function. However, the content of BDNF in TG neurons probably depends on their peripheral targets. BDNF seems to convey nociceptive cutaneous input to the trigeminal sensory nuclei.

Aspartate-immunoreactive primary sensory neurons in the mouse trigeminal ganglion

Aspartate-immunoreactivity (ir) was examined in the mouse trigeminal ganglion (TG). The ir was detected in 34% of TG neurons and their cell bodies were of various sizes (mean +/- S.D. = 1,234 +/- 543 microm(2)). A triple immunofluorescence method revealed the co-expression of aspartate with calcitonin gene-related peptide (CGRP) and parvalbumin; 22% and 14% of aspartate-immunoreactive (ir) neurons were also immunoreactive for CGRP and parvalbumin, respectively. The co-expression of aspartate with both CGRP and parvalbumin was very rare in the TG. By retrograde tracing method, half and 66% of TG neurons which innervate the vibrissa and palate, respectively, contained aspartate-ir. The co-expression of aspartate with CGRP was more common among palatal neurons (36%) compared to vibrissal neurons (22%). Aspartate-ir neurons which co-expressed parvalbumin-ir were numerous in the vibrissa (17%) but not in the palate (4%). These findings may suggest that the function of aspartate-containing TG neurons is correlated with their peripheral receptive fields.

The survival of vagal and glossopharyngeal sensory neurons is dependent upon dystonin

The vagal and glossopharyngeal sensory ganglia and their peripheral tissues were examined in wild type and dystonia musculorum mice to assess the effect of dystonin loss of function on chemoreceptive neurons. In the mutant mouse, the number of vagal and glossopharyngeal sensory neurons was severely decreased (70% reduction) when compared with wild type littermates. The mutation also reduced the size of the circumvallate papilla (45% reduction) and the number of taste buds (89% reduction). In addition, immunohistochemical analysis demonstrated that the dystonin mutation reduced the number of PGP 9.5-, calcitonin gene-related peptide-, P2X3 receptor- and tyrosine hydroxylase-containing neurons. Their peripheral endings also decreased in the taste bud and epithelium of circumvallate papillae. These data together suggest that the survival of vagal and glossopharyngeal sensory neurons is dependent upon dystonin.

TNF blockade: an inflammatory issue

Tumor necrosis factor (TNF), initially discovered as a result of its antitumor activity, has now been shown to mediate tumor initiation, promotion, and metastasis. In addition, dysregulation of TNF has been implicated in a wide variety of inflammatory diseases including rheumatoid arthritis, Crohn's disease, multiple sclerosis, psoriasis, scleroderma, atopic dermatitis, systemic lupus erythematosus, type II diabetes, atherosclerosis, myocardial infarction, osteoporosis, and autoimmune deficiency disease. TNF, however, is a critical component of effective immune surveillance and is required for proper proliferation and function of NK cells, T cells, B cells, macrophages, and dendritic cells. TNF activity can be blocked, either by using antibodies (Remicade and Humira) or soluble TNF receptor (Enbrel), for the symptoms of arthritis and Crohn's disease to be alleviated, but at the same time, such treatment increases the risk of infections, certain type of cancers, and cardiotoxicity. Thus blockers of TNF that are safe and yet efficacious are urgently needed. Some evidence suggests that while the transmembrane form of TNF has beneficial effects, soluble TNF mediates toxicity. In most cells, TNF mediates its effects through activation of caspases, NF-kappaB, AP-1, c-jun N-terminal kinase, p38 MAPK, and p44/p42 MAPK. Agents that can differentially regulate TNF expression or TNF signaling can be pharmacologically safe and effective therapeutics. Our laboratory has identified numerous such agents from natural sources. These are discussed further in detail.

Immunohistochemical localization of gamma and beta subunits of epithelial Na+ channel in the rat molar tooth pulp

The distribution of gamma and beta subunits of epithelial Na(+) channel (ENaC), markers for low-threshold mechanoreceptors in peripheral tissues, was examined in the tooth pulp. In the root pulp, gammaENaC- and betaENaC-immunoreactive (IR) nerve fibers showed a thick smooth appearance. These nerve fibers ascended toward the pulp horn and formed subodontoblastic nerve plexuses. Immunoelectron microscopic method revealed that 63% of axons were immunoreactive for gammaENaC in the root pulp. Virtually all myelinated axons showed gammaENaC-IR (97%), whereas unmyelinated axons were mostly devoid of it (12%). These findings suggest that myelinated tooth pulp nociceptors respond to mechanical stimuli.

Brn-3a is required for the generation of proprioceptors in the mesencephalic trigeminal tract nucleus

The distribution of motor and proprioceptive neurons was investigated in the trigeminal nervous system of wild-type and Brn-3a knockout mice at embryonic day 18.5 and postnatal day 0. We found that the trigeminal motor nucleus (Mo5) contained abundant motoneurons in wild-type (mean number +/- SD per section = 128 +/- 22, range = 93-167) and knockout (mean number +/- SD per section = 121 +/- 23, range = 75-158) mice and that the cell size of Mo5 neurons was similar between these mice (wild-type, mean +/- SD = 165 +/- 59 microm2, range = 65-326 microm2; knockout, mean +/- SD = 167 +/- 59 microm2, range = 71-327 microm2). Mo5 neurons were immunoreactive for calcitonin gene-related peptide and such immunoreactive neurons were abundant in both wild-type and mutant mice. In the mesencephalic tract nucleus (Mes5) of wild-type mice, many proprioceptors (mean number +/- SD per section = 56 +/- 19, range = 27-85) that contained parvalbumin immunoreactivity were also observed. In knockout mice, however, Mes5 neurons could not be detected. The area of brainstems which normally contained the Mes5 was devoid of parvalbumin-immunoreactive proprioceptors. The present study suggests that Brn-3a is required for the development of proprioceptors but not motoneurons in the trigeminal nervous system.

Calretinin-containing neurons which co-express parvalbumin and calbindin D-28k in the rat spinal and cranial sensory ganglia; triple immunofluorescence study

The co-expression of calretinin with parvalbumin and calbindin D-28k was examined in the rat cranial and spinal sensory ganglia by triple immunofluorescence method. In the trigeminal and nodose ganglia, 9% and 5% of calretinin-immunoreactive neurons, respectively, also contained both parvalbumin- and calbindin D-28k immunoreactivity. These neurons had large cell bodies. In the trigeminal ganglion, they were restricted to the caudal portion. Such neurons were evenly distributed throughout the nodose ganglion. The co-expression could not be detected in the dorsal root, jugular or petrosal ganglia. Nerve fibers which co-expressed all the three calcium-binding proteins were observed in the inferior alveolar nerve but not the infraorbital nerve or palate. In the periodontal ligament, these nerve fibers formed Ruffini-like endings. These findings suggest that (1) the co-expression in trigeminal neurons is intimately related to their peripheral receptive fields; (2) the three calcium-binding proteins (calretinin, parvalbumin, calbindin D-28k) co-expressed in the trigeminal neurons may have mechanoreceptive function in the periodontal ligament.

Peptide 19 in the rat vagal and glossopharyngeal sensory ganglia

Peptide 19 (PEP 19) is a 7.6-kDa polypeptide which binds to calmodulin and inhibits calcium-calmodulin signaling. In this study, PEP 19-immunoreactivity (PEP 19-IR) was examined in the rat vagal and glossopharyngeal sensory ganglia. Twenty-nine percent, 59%, and 41% of sensory neurons contained PEP 19-IR in the jugular, petrosal, and nodose ganglia, respectively. These neurons were of various sizes (jugular, mean +/- SD = 635.8 +/- 392.6 microm2, range = 105.9-1695.9 microm2; petrosal, mean +/- SD = 370.9 +/- 228.5 microm2, range = 57.7-1662.7 microm2; nodose, mean +/- SD = 380.5 +/- 157 microm2, range = 87.5-950.4 microm2) and scattered throughout these ganglia. Double immunofluorescence method revealed that PEP 19-IR neurons which had parvalbumin-IR were rare in the ganglia (jugular, 4%; petrosal, 10%; nodose, 8%). PEP 19-IR neurons which contained calbindin D-28k were abundant in the petrosal (20%) and nodose (22%) ganglia but not in the jugular ganglion (8%). Retrograde tracing method indicated that many PEP 19-IR neurons projected to the circumvallate papilla and soft palate. In the soft palate, taste buds were innervated by PEP 19-IR nerve fibers. The present study suggests that PEP 19-IR neurons include chemoreceptors in the vagal and glossopharyngeal sensory ganglia.

Delta-opioid receptor-immunoreactive neurons in the rat cranial sensory ganglia

Immunohistochemistry for delta-opioid receptor (DOR) was performed on the rat cranial sensory ganglia. The immunoreactivity was detected in 16%, 19% and 11% of neurons in the trigeminal, jugular and petrosal ganglia, respectively. The nodose ganglion was devoid of such neurons. DOR-immunoreactive (IR) neurons were mostly small to medium-sized (trigeminal, range = 62-851 microm(2), mean +/- SD = 359 +/- 175 microm(2); jugular, range = 120-854 microm(2), mean +/- SD = 409 +/- 196 microm(2); petrosal, range = 167-1146 microm(2), mean +/- SD = 423 +/- 233 microm(2)). Double immunofluorescence method revealed that all DOR-IR neurons were also immunoreactive for calcitonin gene-related peptide. The cutaneous and mucosal epithelia in the oro-facial region, tooth pulp, taste bud and carotid body were innervated by DOR-IR nerve fibers. In the brainstem, IR nerve terminals were located in the superficial medullary dorsal horn and dorsomedial part of the subnucleus oralis as well as the solitary tract nucleus. The present study suggests that DOR-IR neurons may be associated with nociceptive and/or chemoreceptive function in the cranial sensory ganglia.

Effect of Brn-3a deficiency on primary nociceptors in the trigeminal ganglion

Immunohistochemistry for substance P, somatostatin and vanilloid receptor subtype 1 as well as receptors for somatostatin and opioids was performed on the trigeminal ganglion in wild-type and Brn-3a knockout mice at postnatal day 0. In wild-type mice, the trigeminal ganglion contained abundant substance P-, vanilloid receptor subtype 1-, sst2A receptor- and delta-opioid receptor-immunoreactive neurons, while the ganglion had only a few mu-opioid receptor-immunoreactive neurons. The Brn-3a deficiency had an effect on the cell size but not the number of substance P-immunoreactive neurons. In knockout mice, the proportion of small immunoreactive neurons markedly increased and that of medium- to large-sized immunoreactive ones correspondingly decreased (mean +/- S.D. = 54.7 +/- 29.1 microm2, range = 10.9-220.8 microm2) compared to wild-type mice (mean +/- S.D. = 116.6 +/- 58.6 microm2, range = 27.3-400.7 microm2). As for vanilloid receptor subtype 1-immunoreactive neurons, the number and cell size was barely affected by the deficiency. On the other hand, the loss of Brn-3a caused a decrease in the number of sst2A receptor- or delta-opioid receptor-immunoreactive neurons (more than 95% reduction) and an increase in the number of mu-opioid receptor-immunoreactive neurons (9.3-fold increase). Somatostatin-immunoreactive neurons were not detected in the trigeminal ganglion of wild-type or mutant mice at postnatal day 0. The present study suggests that Brn-3a deficiency may have effects on the survival of trigeminal nociceptors and their expression of some neurochemical substances.

Osteocalcin-immunoreactive neurons in the vagal and glossopharyngeal sensory ganglia of the rat

Immunohistochemistry for osteocalcin (OC) was performed on the rat vagal and glossopharyngeal sensory ganglia. OC-immunoreactive (IR) neurons were detected in the jugular (10%), petrosal (11%) and nodose ganglia (6%). The cell size analysis demonstrated that OC-IR neurons were predominantly small to medium-sized in the jugular ganglion (mean+/-S.D.=356.3+/-192.2 microm(2), range=86.5-831.5 microm(2)). On the other hand, such neurons were medium-sized to large in the petrosal (mean+/-S.D.=725.6+/-280.7 microm(2), range=124.7-1540.4 microm(2)) and nodose ganglia (mean+/-S.D.=857.5+/-330.2 microm(2), range=367.1-1608.0 microm(2)). In the circumvallate papilla, OC-IR nerve fibers were located in the vicinity of taste buds. Some taste bud cells were also immunoreactive for the calcium-binding protein (CaBP). In the carotid body, however, OC-IR nerve fibers could not be detected. Retrograde tracing with fluorogold revealed that OC-IR nerve fibers in the circumvallate papilla mainly originated from the petrosal ganglion. These findings may suggest that OC-IR petrosal neurons have chemoreceptive function in the tongue.

Role of endothelial mitochondria in oxidant production and modulation of neutrophil adherence

This study is designed to test whether the postanoxic endothelial mitochondria is an important source of reactive oxygen species (ROS) using a chemical model of mitochondrial disruption to mimic the loss of mitochondrial integrity after anoxia/reoxygenation (A/R). The current objectives were to (1) determine the adhesion of human neutrophils to human umbilical vein endothelial cells exposed to antimycin A, a specific inhibitor of the mitochondrial cytochrome b-c(1) complex, and (2) define the mechanisms responsible for the early and late phases of neutrophil hyperadhesivity. Antimycin A caused a 5-fold increase in ROS generation and induced neutrophil adhesion at 30 min (phase 1) and 4 h (phase 2) that were quantitatively similar to that induced by A/R. Blockade of electron transport in antimycin A and A/R exposed cells with rotenone, amytal or thenoyltrifluoroacetate, but not myxothiazol, prevented neutrophil adhesion, confirming a role for mitochondrial ROS. Catalase inhibited phase 1 adhesion, indicating H(2)O(2) involvement. Anti-ICAM-1 or anti-P-selectin monoclonal antibodies (mAbs) attenuated phase 1 adhesion, while anti-E-selectin mAb attenuated phase 2 adhesion, consistent with roles for constitutive ICAM-1 and preformed P-selectin in early and E-selectin in late phase responses. Actinomycin D and cycloheximide or competing ds-oligonucleotides containing cognate DNA sequences of the nuclear factor kappaB or activator protein-1 attenuated phase 2 adhesion, implicating a role for de novo protein synthesis. Peak surface expression of the endothelial cell adhesion molecules correlated with peak adhesions at phases 1 and 2. These results show that disruption of mitochondrial respiratory chain elicits ROS production that mediates transcription-independent and -dependent surface expression of various adhesion molecules that leads to a two-phase neutrophil-HUVEC interaction similar to that induced by A/R.

Interleukin-8 expression in the esophageal mucosa of patients with gastroesophageal reflux disease

BACKGROUND

It has been reported that inflammatory cell infiltration can be detected in patients with endoscopically negative gastroesophageal reflux disease (GERD) as well as those with erosive reflux esophagitis. In this study, we examined the expression of mRNA for interleukin (IL)-8, a potent chemokine for neutrophils, in the esophageal mucosa of patients with GERD and compared the results with their endoscopic findings and symptoms.

METHODS

Biopsy samples were obtained from 80 patients. Endoscopic diagnosis was performed according to the Los Angeles classification. Patients with typical symptoms such as heartburn despite normal endoscopic findings were classified as the non-erosive GERD group. Total cellular RNA was extracted from the biopsy samples and IL-8 mRNA was quantified by real-time polymerase chain reaction (PCR). Localization of IL-8 protein in the esophageal mucosa was done by immunostaining.

RESULTS

Expression of IL-8 mRNA was correlated with the endoscopic grade of esophagitis or with inflammatory cell infiltration, but not with the symptoms of the patients. Expression of IL-8 mRNA was also detected in all patients with non-erosive GERD. The level of IL-8 expression in non-erosive GERD was low compared with that in erosive GERD, but was higher than that in normal controls. IL-8 immunostaining was found in the basal layers of the esophageal mucosa. Administration of lansoprazole, a proton-pump inhibitor, decreased both IL-8 mRNA and protein levels in the esophageal mucosa.

CONCLUSION

These results suggest that IL-8 in the esophageal mucosa may be involved in the pathogenesis of esophageal inflammation, including non-erosive GERD.

An orally active matrix metalloproteinase inhibitor, ONO-4817, reduces dextran sulfate sodium-induced colitis in mice

OBJECTIVE

Over-expression of matrix metalloproteinases (MMPs) can accelerate tissue destruction and disrupt subsequent tissue repair. A dextran sulfate sodium (DSS) colitis model was established to examine the effects of MMP inhibition, by an orally active MMP inhibitor ONO-4847, on colonic inflammation.

MATERIALS AND METHODS

Acute colitis was induced in female BALB/c mice by giving 8% DSS orally in drinking water for 7 days. The animals were randomized into groups receiving different concentrations of ONO-4847 or vehicle by oral gavage every day. mRNA levels of 4 MMPs and a tissue inhibitor of MMP (TIMP-1) were measured by RT-PCR in intestinal tissue isolated from mice after DSS administration. Colonic mucosal injury and inflammation were evaluated clinically, biochemically, and histologically. The clinical disease activity index (DAI), including body weight loss, stool consistency, and blood in feces, was examined. Moreover, mucosal tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma were determined by immunoassay.

RESULTS

The intestinal expression of MMP-3, -7, 9, and -12 and TIMP-1 mRNA was upregulated after DSS administration. Shortening of the colon was significantly reversed by ONO-4847 at a dose of 30 mg/kg. DAI in DSS-treated mice was significantly lower in the ONO-4847-treated mice compared with the control mice. Histological study also showed a reduced infiltration of inflammatory cells, especially neutrophils, and reducedmucosal cell disruption in ONO-4847-treated mice compared with the control mice. The increases in tissue-associated myeloperoxidase activity and thiobarbituric acid-reactive substances after DSS administration were both significantly inhibited by co-administration with ONO-4847. ONO-4847 also inhibited increases in the mucosal TNF-alpha and IFN-gamma content after DSS administration.

CONCLUSION

Improvements in DSS colitis in response to ONO-4847 suggest that activation of MMPs contributes to the initiation/amplification of colonic inflammatory injury by mechanisms including oxidative damage as well as enhancement of inflammatory cytokine release.

Neurocalcin-immunoreactive neurons in the petrosal ganglion innervate the taste bud

The distribution and origin of neurocalcin-immunoreactive (NC-ir) nerve fibers in the taste bud and carotid body were examined by an immunofluorescence method. In the circumvallate papilla of the tongue, NC-ir nerve fibers made subepithelial nerve plexuses and occasionally penetrated the taste bud. However, the carotid body was devoid of ir nerve fibers. In the petrosal ganglion, 32% of neurons were immunoreactive for NC. Such neurons were mostly medium-sized to large, and scattered throughout the ganglion. In the superior cervical and intralingual ganglia, numerous ir varicose fibers surrounded postsynaptic neurons. However, NC-ir could not be detected in cell bodies of these neurons. The retrograde tracing method indicated that NC-ir petrosal neurons innervated taste buds in the circumvallate papilla. NC-ir neurons may have a gustatory function in the petrosal ganglion.

Effect of mCOUP-TF1 deficiency on the glossopharyngeal and vagal sensory ganglia

Immunohistochemistry for calcitonin gene-related peptide (CGRP), tyrosine hydroxylase and calbindin D-28k was performed on the glossopharyngeal and vagal ganglia in mCOUP-TFI knockout mice to know the effect of its deficiency on different types of primary sensory neurons. In wild type and heterozygous mice, the glossopharyngeal and vagal ganglia contained abundant CGRP-, tyrosine hydroxylase- and calbindin D-28k-immunoreactive (IR) neurons. In the ganglia of mCOUP-TFI knockout mice, a 38% decrease of CGRP-IR neurons was detected. However, the number of tyrosine hydroxylase- or calbindin D-28k-neurons was not altered by the mCOUP-TFI deficiency. In the tongue of knockout mice, the number of CGRP-IR nerve fibers decreased compared to wild-type and heterozygous mice. The development of CGRP-IR petrosal neurons, which supply innervation of the tongue, may depend on mCOUP-TFI.

Ca2+/calmodulin-dependent protein kinase II in the rat cranial sensory ganglia

Immunohistochemistry for Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) was performed on the rat cranial sensory ganglia. More than one half of neurons was immunoreactive for the enzyme in the trigeminal (60%), jugular (70%), petrosal (55%) and nodose ganglia (63%). These neurons were mainly small to medium-sized. The co-expression study demonstrated that one half of CaMKII-immunoreactive (ir) neurons was also immunoreactive for calcitonin gene-related peptide (CGRP) or the vanilloid receptor subtype 1 (VR1) in the trigeminal, jugular and petrosal ganglia. In the nodose ganglion, CaMKII-ir neurons were mostly devoid of CGRP-immunoreactivity (ir) (8.2%) whereas the co-expression with VR1-ir was common among such neurons (72%). In the facial skin, nasal mucosa and palate, the epithelium and taste bud were innervated by CaMKII-ir nerve fibers. In addition, the retrograde tracing study demonstrated that 39.6% and 44.8% of trigeminal neurons which were retrogradely traced with fluorogold from the facial skin and nasal mucosa exhibited CaMKII-ir. Forty-six percent of petrosal neurons which innervated the soft palate were immunoreactive for the enzyme.

Effect of Brn-3a deficiency on parvalbumin-immunoreactive primary sensory neurons in the dorsal root ganglion

Immunohistochemistry for parvalbumin, a marker for primary proprioceptors, was performed on the dorsal root ganglion (DRG) of wildtype and knockout mice for Brn-3a at postnatal day 0 and embryonic day 18.5. The DRG contained many parvalbumin-immunoreactive (ir) neurons in wildtype (5.4%) and knockout mice (5.6%). Cell size analysis demonstrated that such neurons were mostly medium-sized to large in these mice. Therefore, it is unlikely that the survival of proprioceptors is dependent upon Brn-3a in the DRG. In the dorsal column and gray matter of the spinal cord of knockout mice, however, parvalbumin-ir nerve fibers were sparse compared to wildtype mice. The number of parvalbumin-ir varicosities around motoneurons decreased in the mutant. Thus, our data suggest that Brn-3a may play an important role in the central projection and terminal formation of DRG proprioceptors in the spinal cord.

VR1-, VRL-1- and P2X3 receptor-immunoreactive innervation of the rat temporomandibular joint

Immunohistochemistry for vanilloid receptor subtype 1 (VR1), vanilloid receptor 1-like receptor (VRL-1) and P2X3 receptor was performed in the rat temporomandibular joint (TMJ). Blood vessels in the articular disk and capsule, the synovial membrane and the fibrous tissue around the condylar process were innervated by VR1- or P2X3 receptor-immunoreactive (ir) nerve fibers. However, VRL-1-immunoreactivity (ir) could not be detected in the TMJ. Retrograde tracing and immunohistochemical methods revealed that 25%, 41% and 52% of TMJ neurons in the trigeminal ganglion (TG) exhibited VR1-, VRL-1- and P2X3 receptor-ir, respectively. VR1-ir TMJ neurons were mostly small to medium-sized, whereas VRL-1- and P2X3 receptor-ir TMJ neurons were predominantly medium-sized to large. In addition, 73%, 28% and 44% of VR1-, VRL-1- and P2X3 receptor-ir TMJ neurons, respectively, coexpressed calcitonin gene-related peptide (CGRP)-ir. The present study suggests that the TMJ has abundant nociceptors which respond to vanilloid compounds, protons, heat and extracellular ATP.

The somatostatin sst2A receptor in the rat trigeminal ganglion

Immunohistochemistry for the somatostatin sst2A receptor was performed on the rat trigeminal ganglion to know its function in the trigeminal nervous system. The immunoreactivity was detected in 9.4% of primary sensory neurons in the ganglion. These neurons were small to medium-sized (range=106.5-1123.2 microm(2); mean+/-S.D.=506.3+/-213.2 microm(2)) and predominantly located in the rostromedial part of the ophthalmo-maxillary division. They were also immunoreactive for calcitonin gene-related peptide and the vanilloid receptor subtype 1. In addition, 13.7% of trigeminal neurons which were retrogradely traced with fluorogold from the nasal mucosa exhibited sst2A receptor-immmunoreactivity. Trigeminal neurons which innervated the facial skin and tooth pulp were devoid of the immunoreactivity. In the brainstem trigeminal sensory nuclear complex, both the neuronal cell body and the neuropil exhibited sst2A receptor-immunoreactivity in the superficial medullary dorsal horn.The present study indicates that sst2A receptor-immunoreactive trigeminal nociceptors innervate the nasal mucosa. They may project to the superficial laminae of the medullary dorsal horn.

Lymph node hyalinization in elderly Japanese

Lymph node hyalinization has been comprehensively investigated using specimens obtained from elderly Japanese and white Americans. Onion-peel lesions and associated meshwork areas were often found in the medullary sinus of the thoracic node (mediastinal-type hyalinization), while eosinophilic, glassy and spotty lesions were consistently seen in B lymphocyte areas of the pelvic node (pelvic-type hyalinization). The mediastinal-type hyalinization was comprised of thin collagen fibrils (ca 50 nm in diameter), whereas the pelvic-type hyalinization had thick fibrils (ca 150 nm in diameter). This difference seemed to be consistent with a difference in composite collagen fibrils of vascular walls between the thoracic and pelvic regions. The pelvic-type hyalinization was often or sometimes seen in other nodes, such as cervical, axillary, abdominal and inguinal nodes, especially in white Americans. The mediastinal-type hyalinization, usually in combination with a sinus filled with anthracotic macrophages, tended to be observed in Japanese more frequently than in white Americans. Anthracosis seemed to be connected to the pathogenesis of the hyalinization. On the other hand, because the lesion was weakly positive for Factor VIII immunohistochemistry and because lesions were located along thin vessels, the pelvic-type hyalinization seemed to originate from vascular degeneration in the nodal cortex. Due to the high incidence and large proportion in total volume of the node, the hyalinization seems to be one of the major events that diminish the nodal filtration function and ruin the node with aging.

Pituitary adenylate cyclase-activating polypeptide-immunoreactive nerve fibers in rat and human tooth pulps

The distribution of pituitary adenylate cyclase-activating polypeptide (PACAP) was examined in the tooth pulp. In rat and human tooth pulps, PACAP-immunoreactive (IR) nerve fibers were observed around blood vessels and in the subodontoblastic and odontoblastic layers. The predentine and dentine were devoid of such nerve fibers. The double immunofluorescence method indicated the co-expression of PACAP with calcitonin gene-related peptide (CGRP) or vasoactive intestinal polypeptide (VIP). Virtually all PACAP-IR nerve fibers co-expressed CGRP-immunoreactivity (IR) in the rat tooth pulp suggesting their sensory function. In addition, a retrograde tracing method indicated that PACAP-IR nerve fibers in the rat tooth pulp originated from the trigeminal ganglion. On the other hand, almost all PACAP-IR nerve fibers in the human tooth pulp co-expressed VIP-IR and, thus, thought to be autonomic in nature.

The co-expression of VR1 and VRL-1 in the rat vagal sensory ganglia

Immunohistochemistry for two nociceptive transducers, the vanilloid receptor 1 (VR1) and vanilloid receptor 1-like receptor (VRL-1), was performed on the vagal sensory ganglia. In the jugular ganglion, VR1-immunoreactive (IR) neurons were small to medium-sized (range 49.7-1,125.6 microm(2), mean+/-S.D. 407.7+/-219.7 microm(2)), whereas VRL-1-IR neurons were medium-sized to large (range 223.6-1,341.1 microm(2), mean+/-S.D. 584.3+/-253.5 microm(2)). In the nodose ganglion, VR1- and VRL-1-IR neurons were mostly small to medium-sized (VR1: range 148.5-1464.4 microm(2), mean+/-S.D. 554.3+/-207.4 microm(2); VRL-1: range 161.7-1166.2 microm(2), mean+/-S.D. 541.9+/-186.2 microm(2)). The double immunofluorescence method revealed that co-expression of VR1-immunoreactivity among VRL-1-IR neurons was more abundant in the nodose ganglion (63%) than in the jugular ganglion (4%). The present study suggests that co-expression of VR1 and VRL-1 may be more common in visceral sensory neurons than in somatic sensory neurons.

The effect of rebamipide on Helicobacter pylori extract-mediated changes of gene expression in gastric epithelial cells

BACKGROUND

Recent studies have shown that Helicobacter pylori affects intracellular signal transduction in host cells, leading to the activation of transcriptional factors and the induction of pro-inflammatory cytokines. On the other hand, rebamipide, an anti-gastritis and anti-ulcer agent, could scavenge reactive oxygen species and reduce interleukin-8 (IL-8) expression in gastric epithelial cells induced by H. pylori-stimulation through the attenuated activation of nuclear factor-kappaB (NF-kappaB).

AIMS

In this study, we investigated the effects of rebamipide on gene expression in H. pylori-stimulated epithelial cells using DNA chip.

METHODS

H. pylori water extract (HPE) was prepared from NCTC11637, the type strain of H. pylori. Total RNA was extracted from MKN45 cells, a human gastric cancer cell line, following HPE-stimulation with and without rebamipide for 3 h, and differences in gene expression profiles were observed using GeneChip and Human 6800 probe array.

RESULTS

The GeneChip analysis demonstrated that 132 up-regulated genes and 873 down-regulated genes, such as growth factors, chemokines and transcription factors, were detected in MKN45 cells 3 h after stimulation of H. pylori. Among them, several genes, including bFGF, RANTES and MIP-2beta, were previously unknown to be expressed in H. pylori-stimulated human gastric cells. Rebamipide reduced expression of 119 genes encoding cytokines, growth factors and their receptors and transcription factors.

CONCLUSIONS

These findings suggest that rebamipide could inhibit inflammatory reactions and tumour progression by modifying H. pylori infection-induced gene expression in gastric epithelial cells.

Calcium-binding protein-immunoreactive innervation of the rat vibrissa

Immunohistochemistry detected calcium-binding proteins (CaBPs) in corpuscular and Merkel nerve endings of the rat vibrissa. CaBP-immunoreactive (ir) corpuscular endings were divided into two types: ramified and unramified endings. Ramified endings were subdivided into reticular and Ruffini endings. Unramified endings were identical to longitudinal lanceolate endings which have been described previously. Reticular and unramified endings as well as Merkel endings co-expressed neurocalcin (NC)- and parvalbumin (PV)-immunoreactivity (ir). However, such endings were devoid of peptide 19 (PEP19)-ir. PV-ir Ruffini endings were immunoreactive for PEP19 but not NC. The retrograde tracing method revealed that 34, 21 and 18% of trigeminal neurons which project to the infraorbital nerve exhibited NC-, PEP19- and PV-ir, respectively. In addition, 73 and 36% of the PV-ir neurons showed NC- and PEP19-ir, respectively. The content and co-expression of CaBPs in vibrissal low-threshold mechanoreceptors may depend on their terminal morphology.