HHV-8 infection status of AIDS-unrelated and AIDS-associated multicentric Castleman's disease

Multicentric Castleman's disease (MCD) is a clinicopathologically defined entity characterized by systemic lymphadenopathy with unique pathomorphology such as angiosclerosis, blood vessel proliferation in and around follicles, and plasmacytosis. While its pathogenesis has remained unclarified for many years, identification of the human herpesvirus 8 (HHV-8) in at least some MCD cases has opened new perspectives in this field. Because previous reports have described many inconsistencies regarding HHV-8 positivity in MCD, we intended to clarify this issue by the introduction of more convincing methodologies. For this investigation, we introduced two antibodies produced in our laboratories that recognize a latent gene product ORF73 and a lytic gene product ORF59, together with two well-recognized methods, in situ hybridization for the detection of lytic phase transcript T1.1/nut-1, and genomic polymerase chain reaction (PCR). Eighty-two cases of MCD were collected from Japan (n = 75) and France (n = 7). In three cases, the patients were suffering from acquired immunodeficiency syndrome (AIDS). Immunohistochemistry and in situ hybridization showed identical results: only three out of 82 cases were positively stained, and all the positive cases were found to be the patients with AIDS. Genomic PCR was done in 43 cases, and only one case produced positive results: the only AIDS case among the 43 cases studied by genomic PCR. Histopathologically, the HHV-8-positive cases showed the highest intensity of angiosclerosis and germinal center / perifollicular vascular proliferation, while plasmacytosis was not severe in the HHV-8-positive cases. Some of the HHV-8-negative MCD cases displayed similar histopathology, but at a far less intense level, except for the plasmacytosis. These results suggest that: (i) all three of the HHV-8-positive MCD patients in the present group are the patients with AIDS; and (ii) HHV-8-positive MCD patients develop typical but marked angiosclerosis and vascular proliferation that might be differentiated from HHV-8-negative MCD patients, who showed far less intense changes.

Expression and potential role of angiopoietins and Tie-2 in early development of the mouse metanephros

Angiopoietins (Ang) are secreted factors which bind the Tie-2 receptor and modulate endothelial growth. This signalling system is known to be expressed in later stages of maturation of the mouse metanephros, the adult kidney precursor. In this study, by using reverse transcription polymerase chain reaction and Northern and Western blotting, we demonstrated that Ang-1, Ang-2, and Tie-2 were expressed during early metanephrogenesis when interstitial and glomerular capillaries begin to form. By using immunohistochemistry, embryonic kidney capillaries in the interstitium and glomeruli expressed Tie-2 at a later stage of differentiation compared with vascular endothelial growth factor receptor-2 and platelet-endothelial cell adhesion molecule. Addition of 200 ng/ml Ang-1 to explanted embryonic day (E) 12.5 metanephroi increased the proportion of vascular glomeruli that formed during 1 week in culture. These results are consistent with the hypotheses that Tie-2 has a role in vascular growth in the early stages of mammalian nephrogenesis and that Tie-2 activation may maintain the integrity of recently formed interstitial and glomerular vessels.

Expression of angiopoietin-2 in human glioma cells and its role for angiogenesis

In highly vascular malignant glioma, glioma cells themselves may express angiogenic factors and induce angiogenesis. Recent studies have shown that novel angiogenic factors, angiopoietin-1 (Ang1) and -2 (Ang2), play important roles in the modulation of vasculogenesis and angiogenesis. In this study, we determined Ang2 mRNA expression in cultured human malignant glioma cells (U105, U251, and U373 MG) by reverse transcriptase-PCR. Western blot analysis and immunocytochemical analysis with antihuman Ang2 antibody revealed that Ang2 protein was expressed and secreted by these cells. Furthermore, hypoxia increased the Ang2 protein level in cultured glioma cells. Serial sections of 32 human glioma tissues (14 glioblastomas, eight anaplastic astrocytomas, seven astrocytomas, and three pilocytic astrocytomas) were immunostained against Ang2, vascular endothelial growth factor, Tie2, von Willebrand factor, and alpha smooth muscle actin. The immunoreactivity of each angiogenic factor was higher in malignant gliomas than in low-grade gliomas. Ang2 protein was detected not only in endothelial cells but also in glioma cells, and its expression was prominent in both the area surrounding the necrosis and the periphery of glioblastomas. In the area surrounding necrosis, Ang2 was highly expressed and tumor vessels showed regression. In the tumor periphery, Ang2 was highly expressed and many small vessels stained positively for von Willebrand factor but not for alpha smooth muscle actin, suggesting angiogenesis. Statistical analysis revealed that the Ang2 expression was negatively correlated with vessel maturation in malignant gliomas and that vascular endothelial growth factor expression was positively correlated with vessel maturation in low-grade gliomas (P < 0.05). These results suggest that glioma cells themselves express Ang2 and that expression may be induced by hypoxic stimulation and may play a crucial role in the vessel maturation, angiogenesis, and vessel regression in malignant glioma.

Stromal cells expressing ephrin-B2 promote the growth and sprouting of ephrin-B2(+) endothelial cells

Ephrin-B2 is a transmembrane ligand that is specifically expressed on arterial endothelial cells (ECs) and surrounding cells and interacts with multiple EphB class receptors. Conversely, EphB4, a specific receptor for ephrin-B2, is expressed on venous ECs, and both ephrin-B2 and EphB4 play essential roles in vascular development. The bidirectional signals between EphB4 and ephrin-B2 are thought to be specific for the interaction between arteries and veins and to regulate cell mixing and the making of particular boundaries. However, the molecular mechanism during vasculogenesis and angiogenesis remains unclear. Manipulative functional studies were performed on these proteins in an endothelial cell system. Using in vitro stromal cells (OP9 cells) and a paraaortic splanchnopleura (P-Sp) coculture system, these studies found that the stromal cells expressing ephrin-B2 promoted vascular network formation and ephrin-B2(+) EC proliferation and that they also induced the recruitment and proliferation of alpha-smooth muscle actin (alpha-SMA)-positive cells. Stromal cells expressing EphB4 inhibited vascular network formation, ephrin-B2(+) EC proliferation, and alpha-SMA(+) cell recruitment and proliferation. Thus, these data suggest that ephrin-B2 and EphB4 mediate reciprocal interactions between arterial and venous ECs and surrounding cells to form each characteristic vessel. (Blood. 2001;98:1028-1037)

The membrane-bound but not the soluble form of human Fas ligand is responsible for its inflammatory activity

The ectopic expression of Fas ligand (FasL/CD95L) in tissues or tumors induces neutrophil infiltration and the destruction of the tissues or the rejection of tumors. It has been suggested that the infiltrated neutrophils are responsible for the latter phenomena. FasL is synthesized as a type II transmembrane protein, and soluble FasL is produced by a proteolytic mechanism from the membrane-bound form. We previously demonstrated that uncleavable membrane-bound FasL of mice induces IL-1 beta release from inflammatory cells, and suggested that the IL-1 beta enhances neutrophil infiltration. However, recent papers reported that human soluble FasL is directly chemoattractive to neutrophils in vitro and proposed that the soluble form of FasL is responsible for its inflammatory activity. Therefore, in this report, we investigated which form is responsible for the inflammatory activities of human FasL. We produced tumor cell lines expressing one or both forms of human FasL. Cells expressing both forms or only the membrane-bound form of FasL induced neutrophil infiltration when transplanted into the peritoneal cavity of syngeneic mice, while cells expressing only the soluble form did not. Purified soluble FasL failed to induce neutrophil infiltration in vivo. IL-1 beta release from inflammatory peritoneal exudate and acceleration of tumor rejection were also mediated by membrane-bound but not soluble FasL. These results indicate that the membrane-bound form of FasL is primarily responsible for its inflammatory activity.

Bone morphogenetic protein 2 stimulates osteoclast differentiation and survival supported by receptor activator of nuclear factor-kappaB ligand

Bone is a major storage site for TGFbeta superfamily members, including TGFbeta and bone morphogenetic proteins. It is believed that these cytokines are released from bone during bone resorption. Recent studies have shown that both RANKL and macrophage colony-stimulating factor are two essential factors produced by osteoblasts for inducing osteoclast differentiation. In the present study we examined the effects of bone morphogenetic protein-2 on osteoclast differentiation and survival supported by RANKL and/or macrophage colony-stimulating factor. Mouse bone marrow-derived macrophages differentiated into osteoclasts in the presence of RANKL and macrophage colony-stimulating factor. TGFbeta superfamily members such as bone morphogenetic protein-2, TGFbeta, and activin A markedly enhanced osteoclast differentiation induced by RANKL and macrophage colony-stimulating factor, although each cytokine alone failed to induce osteoclast differentiation in the absence of RANKL. Addition of a soluble form of bone morphogenetic protein receptor type IA to the culture markedly inhibited not only osteoclast formation induced by RANKL and bone morphogenetic protein-2, but also the basal osteoclast formation supported by RANKL alone. Either RANKL or macrophage colony-stimulating factor stimulated the survival of purified osteoclasts. Bone morphogenetic protein-2 enhanced the survival of purified osteoclasts supported by RANKL, but not by macrophage colony-stimulating factor. Both bone marrow macrophages and mature osteoclasts expressed bone morphogenetic protein-2 and bone morphogenetic protein receptor type IA mRNAs. An EMSA revealed that RANKL activated nuclear factor-kappaB in purified osteoclasts. Bone morphogenetic protein-2 alone did not activate nuclear factor-kappaB, but rather inhibited the activation of nuclear factor-kappaB induced by RANKL in purified osteoclasts. These findings suggest that bone morphogenetic protein-mediated signals cross-communicate with RANKL-mediated ones in inducing osteoclast differentiation and survival. The enhancement of RANKL-induced survival of osteoclasts by bone morphogenetic protein-2 appears unrelated to nuclear factor-kappaB activation.

Simultaneous detection of colorectal carcinoma liver and lung metastases does not warrant resection

BACKGROUND

Recent evidence suggests that metastasectomy is efficacious for selected patients with hepatic and pulmonary metastases from a colorectal primary. The aim of this study was to identify a subgroup of patients who best benefit from hepatic and pulmonary metastasectomy among those with colorectal carcinoma metastases.

STUDY DESIGN

We analyzed retrospectively a total of 136 patients who underwent resection of hepatic or pulmonary metastases of colorectal origin at Niigata University Medical Hospital between 1982 and 2000. The median follow-up period was 94 months. Eighty-four patients underwent hepatectomy alone, 25 underwent pulmonary resection alone, and 27 underwent both hepatic and pulmonary resection. The 27 patients undergoing hepatic and pulmonary resection were divided into two groups: 17 patients with sequentially detected hepatic and pulmonary metastases and 10 patients with simultaneously detected metastases. Survival time was determined from the date of initial metastasectomy. Differences in cumulative survival were evaluated using the log-rank test. Sixteen factors were assessed for their influence on the survival of the 27 patients undergoing resection of hepatic and pulmonary metastases; univariate and multivariate analyses were used in this evaluation.

RESULTS

Patient survival after hepatic and pulmonary resection was comparable with that after hepatectomy alone (p = 0.536) and that after pulmonary resection alone (p = 0.294). Among the 27 patients undergoing hepatic and pulmonary resection, the outcomes after resection were significantly better in patients with sequentially detected metastases (cumulative 5-year survival of 44%) than in those with simultaneously detected ones (cumulative 5-year survival of 0%) (p < 0.001). On multivariate analysis sequential detection of hepatic and pulmonary metastases was the strongest independent favorable prognostic factor (p <0.001).

CONCLUSIONS

Patients with sequentially detected hepatic and pulmonary metastases from a colorectal primary are good candidates for aggressive metastasectomy. Simultaneous detection of these metastases does not warrant resection.

Diagnosis of pancreatic adenocarcinoma by detection of human telomerase reverse transcriptase messenger RNA in pancreatic juice with sample qualification

PURPOSE

We evaluated the diagnostic efficacy of detection of human telomerase reverse transcriptase (hTERT) message, a catalytic domain of human telomerase, in endoscopic retrograde pancreatography (ERP)-derived pancreatic juice.

EXPERIMENTAL DESIGN

Both hTERT and CD25 expression were detected by reverse transcription-PCR (RT-PCR) in 17 patients with pancreatic adenocarcinoma (PC), 12 patients with chronic pancreatitis (CP), and 7 patients with no ERP abnormality (N). In the same patients, beta-actin message was semiquantified by competitive RT-PCR. K-ras codon 12 mutations were concomitantly analyzed by enriched PCR-SSCP in 11 and 7 PC and CP cases, respectively.

RESULTS

Expression of hTERT was detected in 88% of PC cases and 17% of CP cases but not in the normal control (N). Alterations in K-ras were detected in 73% of PC cases and 57% of CP cases, respectively. beta-Actin mRNA was expressed in >3.0 x 10(1) copies/microl in all but two PC cases in which hTERT mRNA was not detected. CD25-positive and -negative peripheral lymphocytes were isolated from a normal volunteer using a fluorescent activating cell sorter. The hTERT message was detected in CD25-positive peripheral lymphocytes and in 18, 25, and 0% of the pancreatic juice samples from PC, CP, and N cases, respectively. All CP cases expressing hTERT message were also CD25 positive.

CONCLUSIONS

These results suggest that detection of hTERT mRNA in pancreatic juice is a powerful tool to discriminate PC from CP, particularly when the samples are qualified against beta-actin mRNA levels and contaminating CD25-positive lymphocytes.

Expression of p73 in colorectal carcinoma: clinicopathological relevance

p73 gene expression and its correlation with clinicopathological variables were examined in 92 patients (53 male, 39 female; age range 38 - 89 years) with colorectal carcinoma. Gene expression was determined by immunohistochemical analysis of resected formalin-fixed and paraffin-embedded carcinoma specimens. When p73 staining of each specimen was divided into two modes (small expression, 0-50% and large expression, > 50%), small expression of p73 was obtained in most cases. Tumour, grade, stage, site and size did not correlate with the mode of expression, but tumour recurrence differed according to mode. Expression of p73 was also related to prognosis: large expression indicated a shorter survival period. Our findings suggest that p73 expression plays a role in inducing tumour recurrence, and that analysis of the expression is useful in evaluating the clinical course of colorectal carcinoma post-surgery.

The molecular basis of osteoclast differentiation and activation

Osteoclasts develop from haemopoietic cells of the monocyte-macrophage lineage. Osteoblasts or stromal cells are essentially involved in osteoclastogenesis through cell-cell interaction with osteoclast progenitor cells. Recent findings indicate that osteoblasts/stromal cells express osteoclast differentiation factor (ODF, also called RANKL, TRANCE and OPGL) as a membrane-associated factor in response to several osteotropic factors to support osteoclast differentiation. ODF is a new member of the tumour necrosis factor (TNF) ligand family. Osteoclast precursors, which express RANK, a TNF receptor family member, recognize ODF through cell-cell interactions with osteoblasts/stromal cells, and differentiate into osteoclasts in the presence of macrophage colony-stimulating factor (M-CSF). Osteoclastogenesis inhibitory factor (OCIF, also called OPG), is a secreted TNF receptor, which acts as a decoy receptor for ODF. ODF is responsible for inducing not only differentiation, but also activation of osteoclasts. Interleukin 1 alpha (IL-1 alpha) can be substituted for ODF in inducing the activation of osteoclasts. Recently, it was shown that mouse TNF alpha stimulated the differentiation of M-CSF-dependent mouse bone marrow macrophages into osteoclasts in the presence of M-CSF without any help of osteoblasts/stromal cells. Osteoclast formation induced by TNF alpha was inhibited by antibodies against TNF type 1 receptor (TNFR1) or TNFR2, but not by OCIF. Osteoclasts induced by TNF alpha formed resorption pits on dentine slices only in the presence of IL-1 alpha. These results demonstrate that TNF alpha stimulates osteoclast differentiation through a mechanism independent of the ODF-RANK interaction. TNF alpha and IL-1 alpha may play an important role in pathological bone resorption due to inflammation.

Correlation between 25-hydroxyvitamin D3 1 alpha-hydroxylase gene expression in alveolar macrophages and the activity of sarcoidosis

PURPOSE

To demonstrate expression of the 25-hydroxyvitamin D3 1 alpha-hydroxylase (1 alpha-hydroxylase) gene in human alveolar macrophages and measure the correlations among the 1 alpha-hydroxylase mRNA level, the activity of sarcoidosis, and calcium metabolism.

SUBJECTS AND METHODS

We examined 7 patients with sarcoidosis and 6 control patients with other pulmonary disorders who underwent bronchoalveolar lavage. Levels of 1 alpha-hydroxylase mRNA were measured by semiquantitative polymerase chain reaction amplification. We measured serum levels of calcium, ionized calcium, parathyroid hormone, calcitriol (1,25-dihydroxyvitamin D3), and 25-hydroxyvitamin D3 to evaluate calcium metabolism. To estimate the activity of sarcoidosis, we measured the cell count, the CD4/CD8 ratio in bronchoalveolar lavage cells, and the serum angiotensin-converting enzyme (ACE) activity.

RESULTS

Expression of 1 alpha-hydroxylase was demonstrated in purified human alveolar macrophages. The 1 alpha-hydroxylase mRNA levels in bronchoalveolar lavage cells were fivefold higher in sarcoidosis patients than in control patients (10.8 +/- 3.6 vs. 2.2 +/- 1.4, P <0.003). Among all patients studied, there were significant correlations between the 1 alpha-hydroxylase mRNA level in bronchoalveolar lavage samples and the percentage of alveolar lymphocytes (r = 0.83, P <0.005), the CD4/CD8 ratio (r = 0.77, P <0.02), serum ACE level (r = 0.58, P <0.05), serum ionized calcium level (r = 0.58, P <0.05), and the calcitriol/25-hydroxyvitamin D3 ratio (r = 0.57, P <0.05). In the sarcoidosis patients, a significant correlation was also observed between 1 alpha-hydroxylase mRNA and the percentage of alveolar lymphocytes (r = 0.82, P <0.05).

CONCLUSION

There is a correlation between 1 alpha-hydroxylase gene expression in alveolar macrophages with the activity of sarcoidosis and its associated disturbances in calcium metabolism.

Measurement of the elastic magnetic form factor of (3)He at high momentum transfer

New electron scattering measurements have been made that extend data on the (3)He elastic magnetic form factor up to Q(2) = 42.6 fm(-2). These new data test theoretical conjectures regarding non-nucleonic effects in the three-body system. The very small cross sections, as low as 10(-40) cm(2)/sr, required the use of a high-pressure cryogenic gas target and a detector system with excellent background rejection capability. No existing theoretical calculation satisfactorily accounts for all the available data.

Marked uptake of technetium-99m pertechnetate by parathyroid adenoma

We herewith report an unusual case of primary hyperparathyroidism whose parathyroid adenoma strongly accumulated technetium (Tc)-99m pertechnetate. A 41-year-old woman was referred to our department under the tentative diagnosis of primary hyperparathyroidism. Scintigraphy by thallium-201 chloride showed homogeneous uptake in the whole thyroid, whereas Tc-99m image revealed a strong local accumulation in the middle portion of the right thyroidal lobe. Neck exploration revealed a 12x8x5 mm tumor in the posterolateral region of the right thyroidal lobe, the pathology of which was parathyroid adenoma. In addition, a small nodule (8 mm in diameter) with pathological findings revealing follicular adenoma of the thyroid, was found within the medial portion of the right thyroidal lobe. Both lesions were removed by surgery, and a postoperative Tc-99m scintigraphy no longer demonstrated a significant uptake in the right thyroidal lobe. Since the thyroid adenoma was too small to be detected by any scintigraphic study and located much closer to the median line than the site of the marked accumulation of Tc-99m pertechnetate, it was considered very likely that the parathyroid adenoma concentrated Tc-99m. Search of literature revealed that there have been only thirteen cases of parathyroid tumor reported to date which significantly accumulated Tc-99m pertechnetate. The present patient represents another rare case of parathyroid adenoma showing sueh an unusual scintigraphic image.

[Mycoplasma pneumonia complicated by acute renal failure]

A 17-year-old woman presented with cough and fever. Treatment with cefteram pivoxil and fosfomycin calcium was not effective. Chest radiography showed infiltration with an air bronchogram in the left upper lung field. The case was initially treated as atypical pneumonia by administering minocycline hydrochloride and piperacillin sodium. Since acute renal failure progressed rapidly, we introduced hemodialysis, and renal function improved. The mycoplasma polymerase chain reaction (PCR) in the pharynx smear was positive, and the mycoplasma serum titer was 1280 on admission. On the basis of these findings, mycoplasma pneumonia was diagnosed. Only one other case of mycoplasma pneumonia with hemodialysis has been reported in Japan. We report and assess the pathogenesis of mycoplasma pneumonia complicated by renal dysfunction.

Efficient naked plasmid cotransfection of lung grafts by extended lung/plasmid exposure time

BACKGROUND

Multiple gene cotransfection may be an effective strategy to modulate concurrent pathologic events after lung transplantation. We investigated in vivo naked plasmid lung cotransfection during cold preservation and the role of lung parenchyma/naked plasmid exposure time.

METHODS

F344 rats underwent left main bronchus instillation of pCF1-CAT (chloramphenicol acetyl transferase) (130 microg) +/- pCF1-beta-Gal (beta-galactosidase) (130 microg) in saline. Part Ia: 4 degrees C preservation versus cotransfection. Lung isografts (4 groups, n = 8) were stored after transfection for 1 (2 groups: one received only pCF1-CAT), 6, and 18 hours. Recipient sacrifice was after 48 hours. Part Ib: 4 degrees C preservation versus transgene expression. Rats were sacrificed 48 hours after transfection in a nontransplant setting (2 groups, n = 8; one received only pCF1-CAT). In a third group (n = 8) lungs were harvested 24 hours after transfection, stored for 18 hours, and recipients were sacrificed after 24 hours. The CAT and beta-Gal enzymatic-linked immunosorbent assays were performed. Part II: Lung/plasmid exposure time. In three groups (n = 6) after pCF1-CAT transfection the left main bronchus was not clamped, clamped for 10 minutes, or clamped for 1 hour. Sacrifice was after 48 hours.

RESULTS

Part Ia: Lung CAT protein was (in picograms per 100 microg of total protein): median, 42 (range, 25 to 95) after 1 hour (only CAT); 67 (19 to 296) after 1 hour, 32 (6 to 157) after 6 hours; and 9 (5 to 243) after 18 hours. Lung beta-Gal protein was (in picograms per 100 microg of total protein): median, 20 (range, 5 to 353) after 1 hour; 17 (6 to 157) after 6 hours; 4 (1 to 74) after 18 hours (1 hour versus 18 hours, p = 0.04 for both proteins). CAT and beta-Gal production were significantly correlated (p = 0.0001, r = 0.924). Part Ib: Lung CAT protein was (in picograms per 100 microg of total protein): median, 2 (range, 0.6 to 10) no transplant, only CAT; 7 (0.3 to 13) no transplant; 3 (0.9 to 14) transplant. Part II: Left lung CAT protein was (in picograms per 100 microg of total protein): median, 31 (range, 6 to 83) no clamp; 74 (25 to 430) 10 minutes of clamp; 111 (30 to 263) 1 hour of clamp. Right lung CAT protein was (in picograms per 100 microg of total protein): median, 0.06 (range, 0 to 0.9) no clamp; 1 (0 to 6) 10 minutes of clamp; 1 (0 to 18) 1 hour of clamp.

CONCLUSIONS

Efficient lung isograft endobronchial cotransfection results from using naked plasmid. Cold preservation affects transfection efficiency but not transgene expression. Lung parenchyma/naked plasmid exposure time determines transfection efficiency.

Fluoxetine reduces L-DOPA-derived extracellular DA in the 6-OHDA-lesioned rat striatum

We investigated the effect of fluoxetine, a selective serotonin reuptake inhibitor (SSRI), on L-DOPA-derived extracellular dopamine (DA) levels in the striatum of rats with nigrostriatal dopaminergic denervation using in vivo microdialysis. Treatment with fluoxetine (10 mg/kg, i.p.) induced a 41% reduction in the cumulative amount of extracellular DA during 300 min following L-DOPA administration (50 mg/kg, i.p.; p < 0.01). This effect was antagonized by pretreatment with WAY-100635, a potent 5-HT1A antagonist, indicating that this effect of fluoxetine is due to its indirect 5-HT1A agonistic property. These results suggest that SSRIs may impair motor functions in patients with Parkinson's disease by reducing efflux of exogenous L-DOPA-derived DA.

Activated human T cells directly induce osteoclastogenesis from human monocytes: possible role of T cells in bone destruction in rheumatoid arthritis patients

OBJECTIVE

To elucidate the direct role of human T cells in the induction of osteoclastogenesis in rheumatoid arthritis (RA), by studying human monocytes and the pathogenetic roles of receptor activator of nuclear factor kappaB ligand (RANKL), RANK, and osteoprotegerin (OPG).

METHODS

Synovial tissue obtained at total knee replacement was stained immunohistologically using anti-RANKL, CD3, and CD4 antibodies. Synovial fluid was obtained from patients with RA, osteoarthritis (OA), gout, or trauma. Concentrations of the soluble form of RANKL (sRANKL) and OPG in the synovial fluid were measured by enzyme-linked immunosorbent assay. Activated T cells from peripheral blood mononuclear cells (PBMC) of healthy volunteers were cultured with human monocytes from PBMC.

RESULTS

Immunostaining of the synovial tissue of RA patients demonstrated that RANKL-positive cells were detected in a subset of fibroblast-like synoviocytes and infiltrating mononuclear cells. Double immunostaining revealed that RANKL-positive cells were detected in a subset of CD3+ cells and CD4+ cells. An increased concentration of sRANKL and a decreased concentration of OPG were detected in synovial fluid from RA patients. The ratio of the concentration of sRANKL to that of OPG was significantly higher in synovial fluid of RA patients than in synovial fluid of patients with OA or gout. The activated T cells expressing RANKL induced osteoclastogenesis from autologous peripheral monocytes. The role of RANKL in this osteoclastogenetic process was confirmed by dose-dependent inhibition by OPG.

CONCLUSION

The present study is the first to demonstrate osteoclastogenesis using human-derived T cells and monocytes. In addition, the present findings suggest that excess production of RANKL by activated T cells increases the level of sRANKL in synovial fluid and may contribute to osteoclastic bone resorption in RA patients.

Overexpression of the Csk homologous kinase (Chk tyrosine kinase) induces multinucleation: a possible role for chromosome-associated Chk in chromosome dynamics

The Csk family of non-receptor-type tyrosine kinases consists of Csk and the Csk homologous kinase Chk. Each enzyme suppresses the catalytic activity of Src family kinases by phosphorylating their C-terminal negative regulatory tyrosine residues. Ectopic and transient expression of Chk in COS-1 cells showed nuclear localization of Chk and growth inhibition. To further explore the role of Chk in cell growth, we overexpressed Chk in human immature myeloid KMT-2 cells. Chk overexpression brought about growth retardation and aberrant chromosome movement leading to multinucleation, and these events were accompanied by insufficient formation of mitotic spindles. In vitro kinase assays showed that Chk overexpression suppressed the tyrosine kinase activity of Lyn, a member of the Src family, immunoprecipitated from Triton X-100 lysates. Subcellular fractionation studies revealed that fractions of Chk and Lyn, resistant to Triton X-100 solubilization, are associated with mitotic chromosome scaffolds and spindles. Chk overexpression induced a decrease in autophosphorylation of Lyn and concomitant changes in levels of tyrosine phosphorylation of proteins associated with both fractions. These results indicate that Chk, Lyn and the tyrosine-phosphorylated proteins localize to mitotic chromosomes and spindles, suggesting that Chk-dependent tyrosine phosphorylation, presumably through Lyn, may be involved in chromosome dynamics.

Effect of D-glucose on nitric oxide release from glomerular endothelial cells

BACKGROUND

Altered glomerular production of nitric oxide (NO) may be involved in hyperfiltration in early diabetic nephropathy. However little is known as to the role of glomerular endothelial cells (GECs) in diabetic hyperfiltration and their ability to release NO in response to hyperglycemia.

METHODS

Using an established cell line, we directly monitored NO release from GECs in response to various concentrations of D-glucose, D-mannitol, and L-arginine, an NO synthase (NOS) agonist. L-Arginine-induced NO release was examined in the cells pretreated for different periods up to 24 h with 10 or 30 mM D-glucose. We also measured serially the accumulation of nitrite, the stable metabolite of NO, produced by the cells incubated for up to 24 h under 10 or 30 mM D-glucose conditions in the presence or absence of the NOS inhibitor, L-NAME.

RESULTS

Direct measurement of NO demonstrated that D-glucose, but not D-mannitol, stimulation resulted in a rapid and dose-dependent increase in NO release by the cells. However, L-arginine-induced NO release was attenuated significantly in the cells preincubated for more than 12 h with 30 mM D-glucose compared to 10 mM D-glucose. The L-NAME-inhibitable production of nitrite in the media was significantly increased 1.5--2.0-fold until 6 h after incubation with 30 mM D-glucose compared to 10 mM D-glucose.

CONCLUSIONS

We conclude that D-glucose, but not D-mannitol, produces a rapid and dose-dependent increase in NO release, whereas exposure to high D-glucose for more than 12 h may blunt NOS activity and/or NO stability in the GECs. These observations may therefore be important for glomerular endothelial dysfunction induced by hyperglycemia that is still tentative and may have a role in diabetic nephropathy.

In vitro prevention of cell-mediated xeno-graft rejection via the Fas/FasL-pathway in CrmA-transducted porcine kidney cells

Cell-mediated cytotoxicity may be involved in delayed and/or chronic xenograft rejection in which apoptosis is induced in the grafted cells via the Fas/Fas-ligand (FasL) and perforin/granzyme pathways. One barrier to the potential use of xeonogenic grafts for humans may be Fas/FasL-mediated apoptosis, which would be blocked by the gene expression of cytokine response modifier A (CrmA), a cowpox virus gene product. The purpose of this study is to explore whether crmA is an effective candidate gene for inhibiting apoptosis in an in vitro model of xenograft rejection, using Fas-expressing non-primate cells cultured with a soluble recombinant human FasL (sFasL). A recombinant adenovirus vector expressing CrmA (AxCALNLCrmA) was successfully generated with a Cre-mediated switching system. PK15 cells, derived from a porcine kidney and infected with AxCALNLCrmA and/or AxCANCre at a multiplicity of infection (MOI) ranging from 0.1 to 100, were cultured with human sFasL derived from KFL74.18, a human FasL-overexpressed cell line. The gene-expression level of the PK15 cells was confirmed by CrmA-immune staining. Approximately 70% of the control PK15 cells showed induced apoptosis when cultured with sFasL. In contrast, the apoptosis was dramatically reduced in crmA-gene-transduced PK15 cells. The inhibitory effect of apoptosis increased with an increase in the infection dose of AxCANCre. In addition, the activity of caspases 3 and 8 was significantly inhibited in the crmA-transduced cells. These results indicate that CrmA is an effective gene product for inhibiting Fas/FasL-mediated apoptosis, which suggests the potential therapeutic use of its gene transduction to protect against graft damage due to delayed and/or chronic xenograft rejection.

Expression of discoidin domain receptor 1 tyrosine kinase on the human bronchial epithelium

Discoidin domain receptor 1 (DDR1) tyrosine kinases constitute a novel family of receptors characterized by a unique structure in the ectodomain (discoidin-I domain). The DDR1 ligand is the extracellular matrix protein collagen. To identify receptor tyrosine kinases (RTKs) involved in control of growth and differentiation of human bronchial epithelial (HBE) cells, a polymerase chain reaction-based search for RTKs in HBE cells was performed. DDR1 was the most abundant clone identified. Northern analysis detected a 3.6 kb DDR1 messenger ribonucleic acid (mRNA) expressed in HBE cells and transformed HBE lines, BET-1A and BEAS-2B. In addition, fluorescence-activated cell sorter (FACS) analyses using an anti-DDR1 antibody showed that DDR1 was expressed on HBE cells and two HBE lines. Immunohistochemical staining using human bronchial tissue demonstrated that DDR1 was mainly expressed at the basolateral cell surface of the bronchial epithelium. Furthermore, immunostaining of type IV collagen, a major component of the basement membrane, clearly showed that the basement membrane was closely attached to the basal surface of the bronchial epithelium. Since collagen binds to and activates discoidin domain receptor 1 tyrosine kinase, colocalization of discoidin domain receptor 1 and its ligand type IV collagen demonstrates a potential interaction of discoidin domain receptor 1 on the bronchial epithelium with type IV collagen. Further study of this interaction may define the functional significance of the collagen-discoidin domain receptor 1 signalling pathway in health and in disease.

Localization of recombination activating gene 1/green fluorescent protein (RAG1/GFP) expression in secondary lymphoid organs after immunization with T-dependent antigens in rag1/gfp knockin mice

Secondary rearrangements of immunoglobulin gene segments that generate a new antibody repertoire in peripheral B cells have been described as receptor revision and occur by as yet unknown mechanisms. To determine the importance of recombination activating gene (RAG) expression in receptor revision, heterozygous rag1/green fluorescent protein (gfp) knockin mice were used to examine the location of RAG1 expression in the germinal centers (GCs) of lymphoid follicles after immunization with a variety of T-cell-dependent antigens. Immunization of rag1/gfp heterozygous mice or rag1 homozygous knockout mice reconstituted with rag1/gfp heterozygous spleen cells caused the down-regulation of RAG1/GFP signal in GCs. Although some RAG1/GFP(+) cells appeared in regions surrounding the peanut agglutinin (PNA)(+)GL-7(+) GC area, RAG1/GFP(+) cells did not accumulate in the central region. In addition, the stimulation of spleen B cells with anti-mu antibody plus interleukin-4 (IL-4) or with anti-CD40 monoclonal antibody plus IL-7 did not induce GFP signals at detectable levels in vitro. These results clearly demonstrate that RAG1 re-expression either does not occur or is at extremely low levels in antigen-driven B cells in GCs of secondary lymphoid follicles, suggesting that other mechanisms may mediate the gene rearrangements observed in receptor revision.

Recipient intramuscular gene transfer of active transforming growth factor-beta1 attenuates acute lung rejection

BACKGROUND

Gene transfer into the donor graft has been demonstrated to be feasible in reducing ischemia-reperfusion injury and rejection in lung transplantation. This study was undertaken to determine whether intramuscular gene transfer into the recipient can also reduce subsequent lung graft rejection.

METHODS

Brown Norway rats served as donors and F344 rats as recipients. Recipient animals were injected with 10(10) plaque-forming units of adenovirus encoding active transforming growth factor beta1 (group I, n = 6), beta-galactosidase as adenoviral controls (group II, n = 6), or normal saline without adenovirus (group III, n = 6) into both gluteus muscles 2 days before transplantation. Gene expression was confirmed by enzyme-linked immunosorbent assay. Graft function was assessed on postoperative day 5.

RESULTS

Successful gene transfection and expression were confirmed by the presence of active transforming growth factor beta1 protein in muscle and plasma. Oxygenation was significantly improved in group I (group I vs II and III, 353.6 +/- 63.0 mm Hg vs 165.7 +/- 39.9 and 119.1 +/- 41.5 mm Hg; p = 0.02 and 0.004). The muscle transfected with the transforming growth factor beta1 showed granulation tissue with fibroblast accumulation.

CONCLUSIONS

Intramuscular adenovirus-mediated gene transfer of active transforming growth factor beta1 into the recipients attenuates acute lung rejection as manifested by significantly improved oxygenation in transplanted lung allografts. This intramuscular transfection approach as a cytokine therapy is feasible in transplantation and may be useful in reducing rejection as well as reperfusion injury.