Involvement of simultaneous multiple transcription factor expression, including cAMP responsive element binding protein and OCT-1, for synovial cell outgrowth in patients with rheumatoid arthritis

OBJECTIVE

To elucidate possible roles of several transcription factors in the pathogenesis of rheumatoid arthritis (RA), the transcription factor expression in RA synovial tissue and their contribution to RA synovial cell functions were studied.

METHODS

Single cell suspension of dissociated synovial tissue was cultured to induce in vitro tissue outgrowth of RA synovial cells. Transcription factors were immunohistochemically identified in RA synovial tissue obtained by joint surgery and in the in vitro tissue outgrowth, and confirmed by western blotting and gel shift assays.

RESULTS

Immunohistochemical examination of RA synovial tissue revealed simultaneous expression of various transcription factors (NF-kappa B, c-Jun (a component of AP-1), cAMP responsive element binding protein (CREB), and OCT-1). The same set of transcription factors was expressed in the in vitro tissue outgrowth of RA patients. The early passage RA synovial cells were treated with interleukin 1 beta (IL1 beta) and confirmed translocation of transcription factors into the nucleus by western blotting, and their DNA binding activity by gel shift assays.

CONCLUSION

This study emphasises the importance of the simultaneous expression of several transcription factors for the hyperactivity of RA synovial cells that leads to tissue outgrowth.

Characteristics and efficiency of glutamine production by coupling of a bacterial glutamine synthetase reaction with the alcoholic fermentation system of baker's yeast

Glutamine production with bacterial glutamine synthetase (GS) and the sugar-fermenting system of baker's yeast for ATP regeneration was investigated by determining the product yield obtained with the energy source for ATP regeneration (i.e., glucose) for yeast fermentation. Fructose 1,6-bisphosphate was accumulated temporarily prior to the formation of glutamine in mixtures which consisted of dried yeast cells, GS, their substrate (glucose and glutamate and ammonia), inorganic phosphate, and cofactors. By an increase in the amounts of GS and inorganic phosphate, the amounts of glutamine formed increased to 19 to 54 g/liter, with a yield increase of 69 to 72% based on the energy source (glucose) for ATP regeneration. The analyses of sugar fermentation of the yeast in the glutamine-producing mixtures suggested that the apparent hydrolysis of ATP by a futile cycle(s) at the early stage of glycolysis in the yeast cells reduces the efficiency of ATP utilization. Inorganic phosphate inhibits phosphatase(s) and thus improves glutamine yield. However, the analyses of GS activity in the glutamine-producing mixtures suggested that the higher concentration of inorganic phosphate as well as the limited amount of ATP-ADP caused the low reactivity of GS in the glutamine-producing mixtures. A result suggestive of improved glutamine yield under the conditions with lower concentrations of inorganic phosphate was obtained by using a yeast mutant strain that had low assimilating ability for glycerol and ethanol. In the mutant, the activity of the enzymes involved in gluconeogenesis, especially fructose 1,6-bisphosphatase, was lower than that in the wild-type strain.

MRA as a Primary Screening Technique for Intra- and Extracranial Arterial Occlusive Diseases

We designed a protocol of 3-dimensional phase contrast (3D-PC-) magnetic resonance angiography (MRA), which was performed in the axial plane to assess the circle of Willis and in the coronal plane to assess the arteries of the head and neck, for screening of the intra- and extracranial arterial occlusive diseases. We evaluated the accuracy of 3D-PC-MRA comparing it with intraarterial angiography. In 52 consecutive patients presenting with clinical suspicion of a stroke, common carotid bifurcation (CCB), petrous segment of internal carotid artery (C5 segment), carotid siphon, middle cerebral artery (MCA), posterior cerebral artery (PCA), vertebral artery (VA), and basilar artery (BA) were evaluated. Both examinations were blindly graded as normal, mild (0-29% stenosis), moderate (30-69% stenosis), severe (70-99% stenosis), or occluded. In the two readers experienced and inexperienced in MR interpretation, Spearman rank correlations between the two techniques were 0.917/0.866 (CCB), 0.803/0.758 (C5 segment), 0.837/0.702 (carotid siphon), 0.841/0.787 (MCA), 0.899/0.886 (PCA), 0.935/0.889 (VA), and 0.932/0.900 (BA), respectively (p < 0.0001). 3D-PC-MRA and intraarterial angiography had a good overall agreement, suggesting its use as a primary screening technique for intra- and extracranial arterial occlusive diseases, although the diagnostic accuracy of MRA was relatively poor in the C5 segment, carotid siphon, and MCA presumably due to phase dispersion.

Application of SPET using technetium-99m sestamibi in brain tumours and comparison with expression of the MDR-1 gene: is it possible to predict the response to chemotherapy in patients with gliomas by means of 99mTc-sestamibi SPET?

Technetium-99m sestamibi (MIBI) is thought to be passively taken up by metabolically active tumour cells and effluxed from them by P-glycoprotein (Pgp). This 170-kDa membrane-bound protein, encoded by the MDR-1 gene, acts as an energy-dependent efflux pump for several antineoplastic agents, resulting in multidrug resistance. For this reason, it is of interest whether the tumour's response to chemotherapy can be predicted by MIBI single-photon emission tomography (SPET). In this study, MIBI SPET was compared with thallium-201 (Tl) SPET using magnetic resonance imaging as a guide in 16 patients with untreated brain tumours [ten glioblastomas (GBs), two anaplastic astrocytomas (AAs), two low-grade gliomas (LGASs) and two metastatic brain tumours) and in four patients who had received treatment for with brain tumours (two GBs, two AAs). In addition, we investigated the expression of the MDR-1 gene and its product Pgp in the same patients, and compared the results with MIBI SPET findings. MIBI, as well as Tl, was highly accumulated and retained in the enhanced region of malignant gliomas. In addition, MIBI SPET yielded sharp and well-contrasted images, and the margin of the tumour was more clearly defined than with Tl SPET due to a good signal-to-noise ratio. Follow-up MIBI SPET in patients who had received therapy showed marked uptake in a patient with malignant transformation, who deteriorated clinically. Patients with no uptake on MIBI SPET showed no sign of recurrence. Semiquantitative analysis of untreated patients showed a relationship between the early uptake index (UI, ratio of average count/pixel in the lesion to that in the contralateral area on early images) and the degree of malignancy (early UI = 1.08+/-0.06 in LGASs, 4.10+/-0.84 in AAs, 5.71+/-3.47 in GBs, and 7.52+/-1.52 in metastatic brain tumours). The retention index (RI, ratio of delayed to early UI) of MIBI was significantly lower than that of Tl in metastatic brain tumours (P<0.05), but not in malignant gliomas. Histological and biological investigation of gliomas showed that the MDR-1 gene and its product Pgp were expressed only in normal endothelial cells and not in tumour cells or proliferating endothelial cells; Pgp tended to decrease as the degree of malignancy rose. Hence, the presence of Pgp and the grade of malignancy were inversely related in gliomas. By contrast, immunohistochemical study showed strong accumulation of Pgp in metastatic brain tumour cells. These histopathological findings and MIBI SPET findings are compatible with experimental data; MIBI was washed out by Pgp. The main cause of chemoresistance is probably not an increasing drug efflux by Pgp in gliomas. Thus, MIBI SPET is useful for detecting the active lesions, but may not be useful for predicting the response to chemotherapy in gliomas.

Growth-associated protein-43 (GAP-43) in the regenerating periodontal Ruffini endings of the rat incisor following injury to the inferior alveolar nerve

Alterations in the levels of growth-associated protein 43 (GAP-43)-like immunoreactivity (-LI) were examined in the lingual periodontal ligament of the rat incisor following two types of injury (resection and crush) to the inferior alveolar nerve (IAN). In normal animals, GAP-43-like immunoreactive (IR) structures were observed as tree-like ramifications in the alveolar half of the lingual periodontal ligament of incisors. Under immunoelectron microscopy, GAP-43-LI appeared in the Schwann sheaths associated with periodontal Ruffini endings; neither cell bodies of the terminal Schwann cells nor axonal profiles showed GAP-43-LI. During regeneration of the periodontal Ruffini endings following resection of the IAN, GAP-43-LI appeared in the cytoplasm of the terminal Schwann cell bodies and axoplasm of the terminals. The distribution of GAP-43-LI in the Ruffini endings returned to almost normal levels on days 28 and 56 following the injury. The changes in the distribution of GAP-43-LI following the crush injury were similar to those following resection; however, expression of GAP-43-LI was slightly higher for the entire experimental period compared with the resection. The transient expression of GAP-43 in the terminal Schwann cells and axonal profiles of the periodontal Ruffini endings following nerve injury suggests that GAP-43 is closely associated with axon-Schwann cells interactions during regeneration.

Possible correction of abnormal rheumatoid arthritis synovial cell function by jun D transfection in vitro

OBJECTIVE

Rheumatoid arthritis (RA) is a chronic inflammatory disorder of joints, and excessive proliferation of and proinflammatory cytokine and collagenase production by synovial cells are a principal cause of joint destruction. Recent studies have revealed that c-jun and jun B promote growth of fibroblasts, whereas jun D suppresses fibroblast proliferation and even antagonizes Ras-mediated transformation of the fibroblasts. We analyzed effects of gene transfer-mediated jun D overexpression of synovial fibroblast-like cells in patients with RA.

METHODS

RA synovial fibroblast-like cells were transiently transfected with jun D expression vector. The transfectants were stimulated with tumor necrosis factor alpha, and their subsequent proliferative responses and proinflammatory cytokine and matrix metalloproteinase (MMP) production at the messenger RNA and protein levels were measured.

RESULTS

Transfection with jun D inhibited the proliferation of, and proinflammatory cytokine and MMP production by, RA synovial cells, mainly due to inhibiting their transcription via down-modulation of AP-1 transcription factor.

CONCLUSION

Localized jun D transfection into the synovial cells of affected joints may inhibit aberrant synovial cell function in patients with RA by down-regulating gene transcription. This function suggests a possible clinical application of this gene therapy.

Ontogeny of NADPH-diaphorase in rat forebrain and midbrain

This study characterizes the developmental expression of NADPH-diaphorase from embryo to adulthood in the forebrain, midbrain and cerebellum of rat brain via histochemical staining. On embryonic day 12 no neurons stained. Labeling was observed in certain nuclei from E15 through the postnatal period to adulthood. Labeling in neurons increased or maintained a constant level with increased age. The embryo demonstrated substantial labeling in neurons of the caudate putamen, bed nucleus of the stria terminalis, preoptic area, lateral hypothalamic area, paraventricular thalamic nucleus, ventromedial hypothalamic nucleus, magnocellular nucleus posterior commissure, and periaqueductal central gray. Additional neuronal labeling was observed postnatally in the olfactory bulb, cerebral cortex, amygdala, various nuclei of the thalamus, interpeduncular nucleus, linear nucleus of the raphe, pretectal area and superior colliculus. In the cerebellum, labeling appeared only after P14 in cells of the molecular cell layer and granular cell layer. The sizes of labeled neurons developed significantly from P4 to P14 in several nuclei. The distinctive temporal and spatial expression pattern of NADPH-diaphorase implies that the NO/cGMP system may play an important role in physiological and developmental functions.

[Evaluation of brain tumor by 99mTc-MIBI: comparison study with 201Tl and predictivity of therapeutic effect]

We compared the detectability of 99mTc-MIBI and 201Tl-chloride for brain tumor in relationship with histopathology. We also evaluated correlation between therapeutic effect using ACNU, Cisplatine and the degree of MIBI tumor uptake. The subjects were 31 brain tumor histologically confirmed by operation or biopsy. Dual-isotope SPECT technique was performed at both 20 min and 180 min after tracer injection. A tumor to normal lung ratio on both early (ER) and delayed image (DR) and retention index (RI) were calculated. The positive rates of 99mTc-MIBI (90.3% and 77.4%) were comparable to that of 201Tl (90.3% and 80.6%). In the relationship with histopathology, both MIBI and Tl accumulated in 100% of glioblastoma (GBM), metastasis (meta), anaplastic astrocytoma and 25% of low grade astrocytoma on both early and delayed images. On semiquantitative analysis, there were no statistical significance among GBM, meta and anaplastic astrocytoma of ER, DR, RI in the both radiopharmaceuticals. However, both ER and DR in GBM tended to be higher than those of anaplastic astrocytoma. In spite of intense MIBI uptake, GBM patients died within six months except one patient. We concluded that MIBI can be helpful in detecting brain tumor as Tl. MIBI also might be useful in estimating the degree of malignancy in glioma. However, intense MIBI uptake did not mean favorable therapeutic effect in patients with GBM treated with ACNU and Cisplatine.

The effect of electroconvulsive treatment on thermal hyperalgesia and mechanical allodynia in a rat model of peripheral neuropathy

We tested the ability of electroconvulsive treatment (ECT) to block thermal hyperalgesia and mechanical allodynia in rats with peripheral neuropathy. Repeated ECT (six times daily) significantly reduced thermal hyperalgesia 48 h after the end of the final treatment but had no significant effects on mechanical allodynia. Single ECT had no significant effect on thermal hyperalgesia or mechanical allodynia. Neither single nor repeated ECT had any significant effect on the withdrawal response of sham-operated paws and untreated rats to thermal and mechanical stimuli. The anti-thermal hyperalgesic effect of repeated ECT was reversed by the previous administration of nifedipine (L-type Ca2+ channel blocker). We conclude that, due to effects on the voltage dependent calcium channel, ECT modified one of the pain behaviors induced by nerve injury. ECT may be of use in the treatment of human neuropathic pain.

IMPLICATIONS

We showed that repeated electroconvulsive treatment reduced pain responses to heat stimulation after sciatic nerve injury in rats. This study implies a possible therapeutic effect of electroconvulsive treatment on neuropathic pain.

Comparative analysis of expression of hepatocyte growth factor and its receptor, c-met, in gliomas, meningiomas and schwannomas in humans

Expression of hepatocyte growth factor (HGF) and c-met, a proto-oncogene that encodes a receptor for HGF, was examined in 45 cases of human primary intracranial tumors by means of RT-PCR. In gliomas, HGF and c-met mRNAs were preferentially expressed in high-grade tumors. Co-expression of both genes was observed in glioblastomas (6/15) and in one anaplastic astrocytoma (1/5) but not in low-grade astrocytomas (0/3). By contrast, the c-met gene was consistently expressed in meningiomas (12/14) and schwannomas (8/8). The presence of c-Met protein was confirmed in the tumor cells of glioblastoma, meningioma and schwannoma by immunohistochemical staining. Moreover, all of the schwannoma cases co-expressed the HGF gene. These observations suggest that HGF/c-met expression is somehow related to the disease progression in gliomas, whereas c-Met protein might have an important fundamental biological role in meningioma and schwannoma. Moreover, since all of the schwannoma cases concomitantly expressed the ligand (HGF) and the receptor (c-met) genes, HGF may act in an autocrine fashion in schwannoma.

Carbonic anhydrase isozyme II immunoreactivity in the mechanoreceptive Ruffini endings of the periodontal ligament in rat incisor

The present study describes the distribution of carbonic anhydrase isozyme II (CA II) in the lingual periodontal ligament of the rat incisor. Some thick nerve fibers in the nerve bundle displayed CA II-like immunoreactivity (LI) as well as non-neuronal elements such as osteoclasts. At the alveolar half of the lingual periodontal ligament of the incisor, thick CA II-like immunoreactive (-IR) nerve fibers showed a tree-like raminification, but thin and beaded CA II-IR nerve fibers were rare. Under the electron microscope, CA II-LI were diffusely localized in the axoplasm of the axon terminals surrounded by Schwann sheaths which were immunonegative for CA II. The cell bodies of the terminal Schwann cells associated with the periodontal Ruffini endings did not exhibit CA II-LI. The present immunohistochemical evidence indicates that CA II may participate in the regulation of the intra-neuronal ion in the periodontal Ruffini endings which are thought to be in a state of high neuronal activity.

Calbindin D28k-like immunoreactivity in the developing and regenerating circumvallate papilla of the rat

The distribution of calbindin D28k (CB)-like immunoreactivity (-LI) in the circumvallate papilla (CVP) was examined during development and regeneration following bilateral crush injury to the glossopharyngeal nerve in the rat. In the adult CVP, CB-like immunoreactive (-IR) nerve fibers were observed in the subgemmal region and some penetrated into the taste buds. CB-LI was also detected in the cytoplasm of the spindle-shaped gustatory cells in the lower half of the trench epithelium, which contained numerous synaptic vesicles and bundles of intermediate filaments. These CB-IR gustatory cells made synapse-like contacts with CB-IR nerve terminals. Some CB-IR nerve terminals made contacts with the gustatory cells negative for CB-LI. At least three developmental stages were defined with regard to the developmental changes in the distribution of CB-LI: (1) Stage I (embryonic day (E) 18-postnatal day (P)5): CB-IR nerve fibers appeared in the lamina propria just beneath the newly-formed CVP at E18, but the gustatory epithelium of the CVP contained no CB-IR structures. Taste buds with taste pores appeared at P1. (2) Stage II (P5-10): thin CB-IR nerve fibers began entering the trench epithelium, but no CB-IR cells were observed. (3) Stage III (P10-adult): in addition to the intragemmal and perigemmal CB-IR nerve fibers, very few CB-IR cells appeared in the taste buds around P10, and their numbers increased progressively. The changes in the distribution of taste buds and CB-LI following glossopharyngeal nerve injury were similar to those observed during development. On post-operative day (PO) 4, the taste buds and CB-IR cells decreased markedly in number. These CB-IR cells became round in shape, and the number of CB-IR nerve fibers decreased markedly. On PO8, both taste buds and CB-IR cells disappeared completely. The regenerated taste buds were first observed on PO12, increased rapidly in number by PO20, and increased slowly thereafter. CB-IR nerve fibers accumulated at the subgemmal region and began penetrating into the trench wall epithelium around PO16. CB-IR cells appeared between PO20 and PO24, and their numbers increased progressively and reached the normal level on PO40. The topographical localizations of the taste buds and CB-IR cells during development and regeneration were comparable to those of normal animals. The delay of the time courses for appearance of CB-IR nerve fibers and CB-IR cells compared to the appearance of taste buds during development and regeneration suggests that CB in the gustatory epithelium may participate in the survival of the taste bud cells rather than in the induction of the taste buds.

Reperfusion therapy for acute vertebrobasilar occlusion

SUMMARY

We reviewed retrospectively our experience in treating 10 patients with acute vertebrobasilar occlusion. Nine patients were treated with interventional reperfusion therapy and the remaining one patient with top of the basilar embolism was treated conservatively because of deep coma and decerebrate rigidity with severely reduced cerebral blood flow (CBF) in the brain stem. Among 9 patients with reperfusion therapy, 8 patients underwent intra-arterial thrombolytic therapy and the other one patient had direct percutaneous transluminal angioplasty (PTA). Eight patients had basilar artery occlusion, 1 patient treated with direct PTA had bilateral intracranial vertebral artery occlusion and the other patient had left posterior cerebral artery occlusion presumably preceding top of the basilar embolism. In 4 of 10 patients, residual CBF was evaluated by single photon emission computed tomograpy (SPECT). Successful recanalization with clinical improvement was achieved in 6 of 9 patients (66.7%) treated with reperfusion therapy. In patients with progression or fluctuation of incomplete brain stem syndrome, SPECT revealed preserved residual CBF and successful recanalization with clinical improvement was achieved by interventional reperfusion therapy. On the other hand, in patients with persistent deep coma and decerebrate rigidity, SPECT revealed marked reduction of residual CBF in the brain stem and recanalization could not improve clinical outcome. Preoperative SPECT may be useful to make a decision whether rep er fusion therapy should be performed or not in case of vertebrobasilar occlusion.

Expression of c-Met correlates with grade of malignancy in human astrocytic tumours: an immunohistochemical study

AIMS

Recent studies suggest the involvement of hepatocyte growth factor/scatter factor (HGF/SF) in glioma cell invasion and tumour progression. We investigated the distribution and rate of tumour cells that express c-Met protein, which is the cell-surface receptor for HGF/SF, in astrocytic tumours. The type of cells that express c-Met in tumour tissues was also identified.

METHODS AND RESULTS

c-Met expression was screened immunohistochemically in a total of 43 astrocytic tumours, including 14 low-grade astrocytomas (A), 13 anaplastic astrocytomas (AA) and 16 glioblastoma multiforme (GBM), c-Met reactivity was demonstrated predominantly in the cytoplasm of tumour cells. Bizarre large tumour cells tended to stain intensely. Higher c-Met expression levels (> or = 2+, more than 25% cells were positive) were noted in 21.4% of (A) vs. 53.8% in (AA) and 87.5% in (GBM) (P < 0.001), indicating a clear relationship between c-Met protein staining and higher grade astrocytic tumours. Moreover, c-Met immunoreactivity was also shown in tumour microvasculature, reactive astrocytes, and neurones in the cortex infiltrated by glioma cells. In 85.7% of cases containing infiltrated cortex, neurones were positive vs. no neurones in non-neoplastic regions (P < 0.002).

CONCLUSIONS

This evidence suggests that c-Met expression in the brain could be associated with astrocytoma progression and also reactive process. Immunohistochemical determination of c-Met-expressing cell types helps to understand possible roles of c-Met in tumour tissues.

Mechanisms of KE298, 2-acetylthiomethyl-3-(4-methylbenzoyl) propionic acid, to suppress abnormal synovial cell functions in patients with rheumatoid arthritis

OBJECTIVE

2-Acetylthiomethyl-3-(4-methylbenzoyl) propionic acid, KE298, a derivative or propionic acid developed in Japan has been shown to be effective for suppressing disease activity of rheumatoid arthritis (RA) in clinical trials in Japan. It is thus a candidate as a new disease modifying antirheumatic drug (DMARD). We analyzed effects of KE298 on synovial fibroblast-like cells in patients with RA to obtain insight into the clinical application of this medication.

METHODS

RA synovial fibroblast-like cells were co-cultured with KE298 at 10(-4)-10(-5) M in the presence or absence of tumor necrosis factor-alpha 2 ng/ml, and their subsequent proliferative responses and proinflammatory cytokine and matrix metalloproteinase (MMP) production at the mRNA and protein levels were measured. Effects of KE298 on MMP-1 gene transcription and AP-1 transcription factor expression of RA synovial cells were studied by chloramphenicol acetyltransferase assay and gel shift assay, respectively.

RESULTS

KE298 inhibited proliferation of RA synovial cells, proinflammatory cytokine production, and MMP-1 production mainly by reducing their transcription via downmodulation of AP-1 transcription factor.

CONCLUSION

KE298 inhibits aberrant synovial cell functions of patients with RA by downregulating gene transcription, suggesting clinical application and usefulness of this new DMARD.

Immunocytochemical demonstration of beta 1-subunit of Na+/K(+)-ATPase in the mechanoreceptive Ruffini-like endings of the rat incisor ligament

The localization of one of the isoforms of Na+/K(+)-ATPase, the beta 1-subunit, was investigated in the periodontal Ruffini endings of rat incisors by light- and electron-microscopic immunocytochemistry. Immunoreactivity for the rat beta 1-subunit followed the pattern of dendritic terminal arborization in the alveolar half of the lingual periodontal ligament. Ultrastructurally, the reaction products were localized in dilatations of axons, possibly the terminals of Ruffini-like endings in the periodontal ligament. No immunoreactivity was seen in Schwann cells. The immunostaining results support the view that the beta 1-subunit of Na+/K(+)-ATPase is the predominant isoform in sensory neurones, and that this protein is a useful marker for periodontal Ruffini-like endings.

Calbindin D28K-like immunoreactive nerve fibres in the predentine of rat molar teeth

Immunoelectron-microscopy was applied to reveal the existence of nerve fibres and terminals showing calbindin D28k (CB)-like immunoreactivity (IR) in the rat molar tooth pulp. In the root pulp, thick, smooth-surfaced CB-IR nerve fibres were in bundles accompanying the blood vessels. In the coronal pulp, the fibres arborized repeatedly and extensively. CB-IR nerve fibres had a predominantly thick, smooth-surfaced appearance, though parts appeared thin and beaded. Occasionally some thin, varicose CB-IR nerve fibres ran along the odontoblasts, penetrating into the predentine alongside the dentinal tubules. They could be traced for approx. 10-20 microns into the predentine from the pulp-predentine border. Immunoelectron-microscopy revealed that only some of the nerve terminals in the predentine showed CB-IR, and that predentinal CB-IR nerve terminals were located close to the odontoblast processes. No synaptic structures were observed between them. The presence of CB-IR nerve terminals in the predentine suggests that many, if not all, CB-IR nerve fibres could be nociceptors. The CB could be involved in Ca2+ homeostasis during the activation of nociceptors.

Calretinin-like immunoreactivity in the Ruffini endings, slowly adapting mechanoreceptors, of the periodontal ligament of the rat incisor

The distribution and ultrastructural localization of calretinin (CR)-like immunoreactivity (-LI) were investigated in the lingual periodontal ligament of rat incisors. Some thick nerve fibers within the nerve bundle displayed CR-LI; these CR-like immunoreactive (-IR) nerve fibers entered the alveolar half of the lingual periodontal ligament of the incisor where dendritic terminal arborization was exhibited. Thin and beaded CR-IR nerve fibers were rarely observed in the periodontal ligament. Observations of adjacent sections immunostained with protein gene-product 9.5 (PGP 9.5) revealed that most, if not all, PGP 9.5-IR nerve terminals showing a dendritic arborization expressed CR-LI. Immunoelectron microscopic observations showed that electron-opaque immunoreaction products were localized in the axoplasm of the axon terminals, except for the mitochondria, which were surrounded by Schwann sheaths and multiple-layered basal lamina. Neither cell bodies, the cytoplasmic extension of terminal Schwann cells, nor other cellular elements such as periodontal fibroblasts exhibited CR-LI. The present findings suggest that Ruffini endings, an essential mechanoreceptor in the periodontal ligament and categorized as a slowly adapting mechanoreceptor, express CR-LI, and that CR may participate in the Ca2+ homeostasis against external stimuli in the periodontal Ruffini endings.

Immunohistochemical localization of calbindin D28k in the periodontal Ruffini endings of rat incisors

It was examined whether calbindin D28k (CB) might be located in the rat incisor periodontal Ruffini ending, an essential mechanoreceptor in periodontal ligament, by light- and electron-microscopic immunohistochemistry. Some thick nerve fibers showing CB-like immunoreactivity (LI) entered the lingual half of the periodontal ligament of the incisor and showed the dendritic terminal arborization. Electron-dense immunoreaction products indicating CB-LI were distributed diffusely in axoplasm of the axon terminals, no mitochondria, however, were not labeled. Neither cell bodies nor cytoplasmic extensions of the terminal Schwann cells exhibited CB-LI. CB was presumed to be involved in the maintenance of Ca2+ homeostasis in the mechano-electric transduction in mechanoreceptors in the periodontal ligament.

In vivo mechanisms for the inhibition of T lymphocyte activation by long-term therapy with tacrolimus (FK-506): experience in patients with Behçet's disease

OBJECTIVE

To examine the in vivo mechanisms of suppression of T lymphocyte function in patients with Behçet's disease (BD) undergoing long-term treatment with tacrolimus (FK-506).

METHODS

Intracellular proteins were analyzed by immunoprecipitation and Western blotting. Messenger RNA expression was studied by a polymerase chain reaction-based technique.

RESULTS

Interleukin-2 production was suppressed in patients treated with tacrolimus. This suppression was found to be due to inhibition of interactions between activated calcineurin (Cn) and nuclear factor of activated T cells (NF-AT), inhibition of cleavage of the autoinhibitory domain of the CnA subunit, and inhibition of heterodimer formation by CnA and CnB subunits, resulting in the absence of NF-AT in nuclei of the T cells. We found that T lymphocytes in some BD patients treated with tacrolimus had reduced amounts of FK-506 binding protein (FKBP) in their cytoplasm.

CONCLUSION

Tacrolimus reduces the Cn activity of T cells in vivo by the cumulative effects of several distinct mechanisms. It is plausible that reduced amounts of FKBP may be associated with diminished clinical efficacy in some BD patients receiving prolonged treatment with tacrolimus.

Characterization of T cells specific for an epitope of human 60-kD heat shock protein (hsp) in patients with Behcet's disease (BD) in Japan

BD is prevalent in the area of the Silk Route. It has been shown that hsp are involved in the T cell activation in patients with BD in the UK, where this disease has developed sporadically. We have thus examined whether the T cell response to the hsp-derived peptides may be induced in patients with BD in Japan, an east pole of the Silk Route. As with patients in the UK, the human 60-kD hsp peptide 336-351 also yielded vigorous proliferation of T cells in Japanese patients with BD, but neither in normal subjects nor in patients with rheumatoid arthritis (RA); there was significant association between proliferation by this peptide and the presence of ocular lesion, but not any other symptoms of BD. To clarify whether the peptide stimulates T cells as a polyclonal activator, a specific antigen or a superantigen-like substance, we analysed T cell receptor (TCR) usage of responding T cells by means of MoAbs specific for TCR Vbeta subfamily and polymerase chain reaction (PCR)-single-strand conformation polymorphism (SSCP)-based technique. We found that T cells with certain TCR Vbeta subfamilies (including Vbeta5.2-3, 8, 13.6, 18, 21.3) were increased in circulation and responded to the hsp peptide in an antigen-specific fashion. In addition, TCR Vbeta gene-amplified products of freshly isolated T cells of patients with BD formed several bands in the PCR-SSCP analysis; some of them became prominent after stimulation with the peptide. This suggests that T cells in patients with this disease have already been expanded oligoclonally in vivo, which may be a result of stimulation by triggering antigens, including the hsp peptide. In addition, hsp peptide stimulation induced proinflammatory cytokine mRNA expression in peripheral blood mononuclear cells, including IL-8, tumour necrosis factor-alpha (TNF-alpha) and TNF-beta in eight out of eight patients studied. Taken together, the results suggest that hsp antigen may play a role in the pathogenesis of BD, not only in the area of the Silk Route, but also outside the Silk Route area.

Autoreactive T cell clones from patients with systemic lupus erythematosus support polyclonal autoantibody production

This work examines the functional properties and TCRbeta gene utilization of 15 autoreactive T cell clones derived from five patients with systemic lupus erythematosus. All these clones proliferated and secreted cytokine when stimulated in vitro by autologous (but not allogenic) B cells. Individual T cell clones used diverse TCRbeta genes and did not show skewing toward the preferential usage of anionically charged receptors. Autoreactive T cell clones supported polyclonal B cell activation, as characterized by the production of anti-DNA, anti-Sjögren syndrome A, and anti-tetanus toxoid (anti-TT) Abs. This T cell help was mediated through the production of immunostimulatory cytokines, especially IL-6. Although stimulation of the autoreactive clones was blocked by anti-HLA class II Abs, the T cell clones did not proliferate, nor did they support polyclonal IgG production by HLA class II-matched normal B cells. Unlike the autoreactive clones, TT-specific clones derived from the same patients provided help selectively to B cells secreting anti-TT Abs. These findings suggest that autoreactive T cells from systemic lupus erythematosus patients are triggered to provide help following cognate interactions with self-peptides presented in the context of HLA class II molecules expressed on autologous B cells regardless of their specificities.

Autoreactive T cell clones from patients with systemic lupus erythematosus support polyclonal autoantibody production

This work examines the functional properties and TCRbeta gene utilization of 15 autoreactive T cell clones derived from five patients with systemic lupus erythematosus. All these clones proliferated and secreted cytokine when stimulated in vitro by autologous (but not allogenic) B cells. Individual T cell clones used diverse TCRbeta genes and did not show skewing toward the preferential usage of anionically charged receptors. Autoreactive T cell clones supported polyclonal B cell activation, as characterized by the production of anti-DNA, anti-Sjögren syndrome A, and anti-tetanus toxoid (anti-TT) Abs. This T cell help was mediated through the production of immunostimulatory cytokines, especially IL-6. Although stimulation of the autoreactive clones was blocked by anti-HLA class II Abs, the T cell clones did not proliferate, nor did they support polyclonal IgG production by HLA class II-matched normal B cells. Unlike the autoreactive clones, TT-specific clones derived from the same patients provided help selectively to B cells secreting anti-TT Abs. These findings suggest that autoreactive T cells from systemic lupus erythematosus patients are triggered to provide help following cognate interactions with self-peptides presented in the context of HLA class II molecules expressed on autologous B cells regardless of their specificities.

Regeneration of periodontal primary afferents of the rat incisor following injury of the inferior alveolar nerve with special reference to neuropeptide Y-like immunoreactive primary afferents

Regeneration of primary afferents and the expression of neuropeptide Y (NPY) in the lingual periodontal ligament of the rat incisor were examined following different types of injury (resection or crush) of the inferior alveolar nerve (IAN) combined with superior cervical ganglionectomy. In normal animals, protein gene product 9.5 (PGP 9.5)-like immunoreactivity (-LI) was localized in the middle areas of the alveolus-related part of lingual periodontal ligament; some of these nerve fibers showed terminal ramification and morphologies resembling those of the periodontal Ruffini endings, and very few thin varicose NPY-like immunoreactive (-IR) nerve fibers were detected around the blood vessels. Three days following crush injury of the IAN, the number of PGP 9.5-IR nerve fibers decreased, then increased to the normal levels around 10-15 days following injury. NPY-IR primary afferents first appeared around 5 days following crush injury, increased in number gradually, reaching a peak around 14 days, and then decreased. No NPY-IR primary afferents were detected 56 days following crush injury of the IAN. The terminal morphology of NPY-IR primary afferents observed around 10-14 days following injury was similar to that of PGP 9.5-IR nerve fibers in the normal animals, but less expanded. The changes in distribution of PGP 9.5-IR and NPY-IR nerve fibers following resection were similar to those observed following crush injury but regeneration was slightly delayed. The present results suggest that injury-evoked NPY is closely associated with the regeneration process of mechanoreceptors in the periodontal ligament following injury of the IAN.

Establishment and characterization of a new human glioblastoma cell line (MGM-1) with highly motile phenotype

A new cell line MGM-1 was established from a primary tumor of the left temporal lobe with histological diagnosis of glioblastoma multiforme, removed from a 64-year-old Japanese male. The patient died of recurrence and unusual extracranial metastases of the tumor 7 months after the surgery. The cultured MGM-1 cells are spindle or polygonal in shape. After serial passages, glial fibrillary acidic protein became negative immunocytochemically in vitro. The modal chromosome number was 61-64. Doubling time and soft agar colony forming efficiency were 42.9h and 0.4%, respectively (at 25th passage). MGM-1 is a highly motile cell line in vitro and its serum-free conditioned medium is chemotactic and chemokinetic for other glioma cells. Secretion of gelatinases (probably MMP-2/72-kDa type i.v. collagenase) and MMP-9/92-kDa type i.v. collagenase) and urokinase-type plasminogen activator were also investigated. MGM-1 would therefore be useful for studying the mechanisms regulating glioma-cell motility and invasion. The MGM-1 cell line has been propagated continuously by serial passages (more than 100 passages) during the past 4 years.