Inefficient function of the signal sequence of PTHrP for targeting into the secretory pathway

Parathyroid hormone-related peptide (PTHrP) is not only secreted out of cells, but also targeted to the nucleoli due to a nucleolar targeting signal (NTS). We assessed the molecular mechanism underlying the dual targeting of PTHrP by constructing a series of truncated forms of rat PTHrP cDNA and expressing them in CHO cells. Immunostaining was observed in both the Golgi apparatus and nucleoli in the same cell expressing PTHrP with the N-terminal full-length signal sequence. When PTHrP molecules were translated from CUGs downstream of the AUG-initiator codon in the signal sequences, potential alternative initiators of the translation, they were exclusively localized in the nucleoli. In contrast, when a construct containing only the ATG-initiator codon was expressed, PTHrP was found to localize in both the nucleolus and the Golgi apparatus. No nucleolar staining of PTHrP was observed in the CHO cells transfected with PTH/PTHrP receptors even after incubating with a conditioned medium containing PTHrP, ruling out a possibility that PTHrP is, once secreted, internalized via receptor-mediated endocytosis and subsequently conveyed to nucleoli. Compatible with these morphological observations, a preproform of PTHrP was found in the cells expressing PTHrP in addition to proPTHrP, indicative of molecules along the secretory pathway. These results strongly indicate that the signal sequence of PTHrP is not sufficient to direct all the newly synthesized molecules across the endoplasmic reticulum, resulting in part of it being delivered to the nucleoli due to the NTS.

Tensile stress induced osteoblast differentiation and osteogenesis in mouse calvarial suture in culture: possible involvement of BMP-4 and other genes

Mechanical stress is one of the most potent inducer of bone formation. The mechanism by which cells receive and transduce the signal into osteogenesis, however, remains unknown. Previous studies have demonstrated that mechanical stress causes changes in expression levels of many genes in osteoblasts and osteocytes both in vivo and in vitro. However, none of these changes are specific to bone cells. Moreover it is not clear which types of cells contributed to the increased osteoblasts induced by mechanical stress. The purpose of this study, therefore, was to identify which cells differentiate into osteoblasts and to examine how the expression of genes that are specific to osteogenic cells changes.

Tumor antigen presentation by dermal antigen-presenting cells

Several phenotypes of antigen-presenting cells are present in the dermis, where they presumably function to present encountered antigens for immune responses. This study examined the ability of dermal antigen-presenting cells to present tumor-associated antigens for the induction of in vivo antitumor immunity. Total murine dermal cells were exposed either to medium alone or to medium containing tumor-associated antigens from S1509a tumor cells. Subsequently, dermal cells were injected subcutaneously at weekly intervals into naïve mice for a total of three immunizations. One week following the final immunization, mice were challenged with living tumor cells. In these experiments, dermal cells pulsed with tumor-associated antigens induced protective immunity to tumor growth. Dermal cells exposed to tumor-associated antigens were also able to elicit delayed-type hypersensitivity after footpad injection into mice previously immunized against S1509a tumor cells. The ability to present tumor-associated antigens for both induction of antitumor immunity and elicitation of delayed-type hypersensitivity was dependent on I-A+ cells and was genetically restricted. Finally, dermal cells tended towards eliciting a greater antitumor delayed-type hypersensitivity response than epidermal cells. These results show that the murine dermis contains antigen-presenting cells capable of processing S1509a tumor antigens for the generation of protective antitumor immunity in vivo.

Recent studies on the biological action of parathyroid hormone (PTH)-related peptide (PTHrP) and PTH/PTHrP receptor in cartilage and bone

Mice with a targeted deletion of parathyroid hormone (PTH)-related peptide (PTHrP) develop a form of dyschondroplasia resulting from diminished proliferation and premature maturation of chondrocytes. Abnormal, heterogeneous populations of chondrocytes at different stages of differentiation were seen in the hypertrophic zone of the mutant growth plate. Although the homozygous null animals die within several hours of birth, mice heterozygous for PTHrP gene deletion reach adulthood, at which time they show evidence of osteopenia. Therefore, PTHrP appears to modulate cell proliferation and differentiation in both the pre and post natal period. PTH/PTHrP receptor expression in the mouse is controlled by two promoters. We recently found that, while the downstream promoter controls PTH/PTHrP receptor gene expression in bone and cartilage, it is differentially regulated in the two tissues. 1alpha,25-dihydroxyvitamin D3 downregulated the activity of the downstream promoter in osteoblasts, but not in chondrocytes, both in vivo and in vitro. Most of the biological activity of PTHrP is thought to be mediated by binding of its amino terminus to the PTH/PTHrP receptor. However, recent evidence suggests that amino acids 87-107, outside of the amino terminal binding domain, act as a nucleolar targeting signal. Chondrocytic cell line, CFK2, transfected with wild-type PTHrP cDNA showed PTHrP in the nucleoli as well as in the secretory pathway. Therefore, PTHrP appears to act as a bifunctional modulator of both chondrocyte proliferation and differentiation, through signal transduction linked to the PTH/PTHrP receptor and by its direct action in the nucleolus.

Localization of alkaline phosphatase and osteopontin during matrix mineralization in the developing cartilage of coccygeal vertebrae

We observed the manner in which alkaline phosphatase (ALPase) and osteopontin were localized in the cartilage and intramembranous bone of coccygeal vertebrae during matrix mineralization, shedding considerable light on the manner in which they develop. In the cartilage matrix of coccygeal vertebrae, we observed the localization of ALPase activity in the boundary of the proliferative and the hypertrophic zones. Granular nodules of mineralization were consistently found in the boundary of both zones, and increased in size when close to the hypertrophic zone. While osteopontin was rarely present in the early stages of mineralization, its localization along the margins of mineralized matrices in the hypertrophic zone was prominent. In contrast to cartilage, mineralized nodules in the intramembranous bone in the mid-portion of the vertebra displayed osteopontin-immunoreactivity, indicating its early synthesis and subsequent accumulation to early-stage mineralized nodules. When blood vessels, accompanied by osteoblastic and osteoclastic cell populations, invaded the cartilage, osteopontin was localized in the lower region of the hypertrophic zone, despite its maintaining the localization of ALPase and early-stage mineralization. Thus, our investigation demonstrated ALPase activity consistent with early-stage mineralization in the cartilage matrix. However, the fact that osteopontin-localization could not be pinpointed might account for its multifunctionality as concerns both the regulation of mineralization and the attachment of migrating osteogenic and osteoclastic cells to the mineralized matrix.

Possible interference between tissue-non-specific alkaline phosphatase with an Arg54-->Cys substitution and acounterpart with an Asp277-->Ala substitution found in a compound heterozygote associated with severe hypophosphatasia

Tissue-non-specific alkaline phosphatase (TNSALP) with an Arg(54)-->Cys (R54C) or an Asp(277)-->Ala (D277A)substitution was found in a patient with hypophosphatasia [Henthorn,Raducha, Fedde, Lafferty and Whyte (1992) Proc. Natl. Acad. Sci. U.S.A.89, 9924-9928]. To examine effects of these missense mutations onproperties of TNSALP, the TNSALP mutants were expressed ectopically inCOS-1 cells. The wild-type TNSALP was synthesized as a 66-kDa endo-beta-N-acetylglucosaminidase H (Endo H)-sensitive form, and processed to an 80-kDa mature form, which is anchored to the plasma membrane via glycosylphosphatidylinositol (GPI). Although the mutant proteins were found to be modified by GPI, digestion with phosphatidylinositol-specific phospholipase C, cell-surface biotinylation and immunofluorescence observation demonstrated that the cell-surface appearance of TNSALP (R54C) and TNSALP (D277A) was either almost totally or partially retarded respectively. The 66-kDa Endo H-sensitive band was the only form, and was rapidly degraded in the cells expressing TNSALP (R54C). In contrast with cells expressing TNSALP(R54C), where alkaline phosphatase activity was negligible, significant enzyme activity was detected and, furthermore, the 80-kDa mature form appeared on the surface of the cells expressing TNSALP (D277A). Analysis by sedimentation on sucrose gradients showed that a considerable fraction of newly synthesized TNSALP (R54C) and TNSALP(D277A) formed large aggregates, indicating improper folding and incorrect oligomerization of the mutant enzymes. When co-expressed with TNSALP (R54C), the level of the 80-kDa mature form of TNSALP (D277A)was decreased dramatically, with a concomitant reduction in enzyme activity in the co-transfected cell. These findings suggest that TNSALP(R54C) interferes with folding and assembly of TNSALP (D277A) intrans when expressed in the same cell, thus probably explaining why a compound heterozygote for these mutant alleles developed severe hypophosphatasia.

Preliminary results of myoblast injection into the urethra and bladder wall: a possible method for the treatment of stress urinary incontinence and impaired detrusor contractility

The purpose of this study is to explore the feasibility of myoblasts, the precursors of muscle fibers, injected periurethrally as a potential treatment of stress urinary incontinence. We also studied myoblast injection into the bladder wall to potentially improve detrusor contractility. A myoblast cell line was transduced with adenovirus carrying the expression of the beta-galactosidase reporter gene while in culture. The cells were incubated with fluorescent latex microspheres (FLMs) to follow the outcome of the injected cells. The tissue was harvested 3-4 days after injection; sectioned, fixed, assayed for beta-galactosidase expression, and counterstained with H+E. Photographs of the slides were taken under light and fluorescence microscopy. We have noted a large number of cells expressing beta-galactosidase and containing FLMs in the urethral and bladder walls under fluorescent microscopy (8 animals). Many regenerative myofibers expressing beta-galactosidase were also seen in the urethral and bladder walls. The fusion of injected myoblasts to form myotubes was seen in both the urethral and bladder walls. The introduction of myoblasts into the urethral and bladder wall is feasible and results in formation of myotubes and myofibers in the smooth muscle layers of the lower urinary tract. We hypothesize that myoblast injections can be used as a non-allergenic agent to enhance urethral closure and bladder function.

Matrix vesicle calcification in bones of adult rats

To clarify the calcification mechanism that functions in bone formation in adult rats, the ultrastructure of tibial trabeculae and calvarial endostea obtained from 8- to 18-month-old rats was investigated morphologically, and compared with that of 19.5-day post-coitum fetal rats. In both samples, osteoid was observed between the activated osteoblasts and the calcified matrix, which contained matrix vesicles enclosed by a biological membrane. Some of these vesicles contained needle-like crystals thought to be hydroxyapatite, suggesting probable matrix vesicle calcification. These results indicate that matrix vesicle function not only in the initial calcification that occurs during embryonic ossification but also contribute to bone formation in adults.

Induction of anti-tumor immunity with epidermal cells pulsed with tumor-derived RNA or intradermal administration of RNA

The skin is well-suited to serve as a substrate for vaccination strategies. In this regard, epidermal cells exposed to granulocyte-macrophage colony-stimulating factor can, upon subcutaneous injection into naïve mice, present a soluble extract of tumor as a source of tumor-associated antigens for the induction of in vivo anti-tumor immunity. Use of RNA for immunization has a potential advantage over this technique. Because RNA can be amplified, only a small amount of tumor is needed for antigen preparation and, as with a soluble extract, it is not necessary to know the molecular nature of the antigen(s) relevant to immunity. To test the hypothesis that RNA-pulsed epidermal cells can induce anti-tumor immunity, total cellular RNA was isolated from the S1509a spindle cell tumor and used to pulse CAF1 epidermal cells enriched for Langerhans cell content and pre-exposed to granulocyte-macrophage colony-stimulating factor. These cells were then injected subcutaneously into naïve CAF1 mice three times at weekly intervals followed by challenge with living S1509a cells. Tumor growth was significantly less than in control animals immunized in an identical fashion but with irrelevant RNA. Digestion of S1509a RNA with RNase prior to pulsing of epidermal cells prevented the development of immunity. In separate experiments, intradermal injection of S1509a RNA into naïve mice three times at weekly intervals also induced immunity to challenge with the tumor. Digestion of S1509a RNA with RNase also prevented development of immunity in this system. Effective anti-tumor immunity can be induced in mice utilizing RNA-pulsed epidermal cells for in vivo immunization or by injecting RNA intradermally into naïve mice.

Papaverine combined with prostaglandin E2 synergistically induces neuron-like morphological changes and decrease of malignancy in human prostatic cancer LNCaP cells

We are interested in the possibility of new prostate cancer therapy that would control tumor malignancy via the induction of terminal cell differentiation. Here, we investigated the combined effect of various cAMP reagents on LNCaP human prostate carcinoma cells. Papaverine and prostaglandin E2 (PGE2), combined synergistically induced morphological changes. Electron microscope study suggested that cells treated with both reagents become like neuroendocrine cells. We then investigated the effect of both reagents on proliferation and malignancy of LNCaP cells. The malignancy of cells was analyzed by soft agar colony-forming assay and an in vitro invasion assay. Proliferation and malignancy of LNCaP cells treated with both reagents were significantly decreased in comparison to the proliferation and malignancy of untreated cells. Furthermore, the expression of oncogenes such as c-myc and Bcl-2 was suppressed in differentiated LNCaP cells. These results suggest that papaverine combined with PGE2 can synergistically induce neuronal differentiation as well as decrease the malignancy of human prostatic cancer LNCaP cells.

Removal of UroLume endoprosthesis: experience of the North American Study Group for detrusor-sphincter dyssynergia application

PURPOSE

We present the experience of the North American UroLume Multicenter Study Group with removal of the UroLume endoprosthesis.

MATERIALS AND METHODS

A total of 160 neurologically impaired patients were enrolled in the North American UroLume Multicenter Study Group for detrusor external sphincter dyssynergia application. Analysis was performed in 2 groups of patients in which the device was removed during insertion and after implantation, respectively.

RESULTS

Device retrieval was required during insertion in 21 patients (13%) mainly due to misplacement or migration in 17. Extraction was done with minimal complications and in all but 2 cases subsequent UroLume implantation was successful. Of 158 men with the device in place 31 (19.6%) required removal. In 34 procedures 44 devices were removed, mainly due to migration. Time from implantation to removal ranged from 4 days to 66 months (mean 22 months). The UroLume was removed en bloc in 20 cases and in parts or wire by wire in 19. The majority of patients had no or minimal complications after extraction. Only 2 patients had serious temporary complications, including bleeding and urethral injury, with no lasting consequences. No malignancy developed as a result of UroLume insertion.

CONCLUSIONS

While there is a potential for urethral injury and bleeding, UroLume endoprosthesis removal is largely a simple procedure with minimal complications and consequences.

Antibody studies of factor VIII inhibitor in a case with Waldenström's macroglobulinemia

We report a case of Waldenström's macroglobulinemia with prominent bleeding tendency; laboratory investigation revealed an elevated activated partial thromboplastin time. Further laboratory evaluation showed circulating factor VIII anticoagulant, deemed polyclonal IgG, with a titer of 700 Bethesda Units/ml. The factor VIII inactivation kinetics of the patient plasma were identical to those of a type II inhibitor, and the inhibitor was found to recognize the A2 domain of the factor VIII heavy chain. Apparently, paraprotein is not always the cause of reduced activity of coagulation factors in neoplastic dysproteinemias.

Neuropsychological changes after surgery for anterior communicating artery aneurysm

Neuropsychological disturbances following surgery for anterior communicating artery aneurysms were analyzed in 26 patients (11 males, 15 females) using the Hasegawa dementia scale-revised (HDS-R) over a 3-year period. The patients were aged from 34 to 76 years (mean 54.1 years). Lesions in the frontal lobe were evaluated using computed tomography (CT). Twenty-three patients had symptoms over the course. Four patients had basal forebrain lesion, five had ventral frontal lesion, and 12 had no lesion. Patients with basal forebrain lesion and no lesion tended to show disorientation. The mean HDS-R score was 10.2 points in the patients with ventral frontal lesion, and 13.5 points in the patients with no lesion. These scores are within the range for dementia. The mean HDS-R score in patients with basal forebrain and striate lesions was over 25 points and beyond the range for dementia. Significant differences were observed in the HDS-R score between patients with ventral frontal lesion and basal forebrain lesion, and between patients with no lesion and basal forebrain lesion (p < 0.05). Recovery from neuropsychological disturbances was poorer in patients with ventral frontal lesion and no lesion compared to those with basal forebrain and striate lesions, and their symptoms tended to persist.

Effect of intermittent administration of human parathyroid hormone (1-34) on the mandibular condyle of ovariectomized rats

Intermittent administration of human parathyroid hormone (1-34) (PTH) increases bone mass in lumbar vertebrae and long bones of osteoporotic experimental animals. However, whether PTH has the same effect on jaw bones remains unclear. This study determined the effect of intermittent administration of PTH on rat mandibular condyle affected by estrogen deficiency. Fifty 6-month-old rats were either sham operated or ovariectomized, then divided into five groups depending on surgical procedure and hormone administration: sham + vehicle (SV), OVX + vehicle (OV), OVX + PTH 6 micrograms/kg once per week (OP6-1), OVX + PTH 60 micrograms/kg once per week (OP60-1), and OVX + PTH 20 micrograms/kg three times per week (OP20-3). PTH or vehicle was injected intermittently for 6 months in 5 rats of each group either immediately after surgery in a preventive administration experiment, or injected starting 6 months after surgery in a therapeutic administration experiment. The mandibles were excised, and bone morphometry was performed using confocal laser scanning microscopy and soft X-ray images. In both experiments, the bone volume of the OV groups was significantly lower than that of the SV group (P < 0.01); also, depending on dose and frequency, the bone volume of the OP group was higher than that of the OV group, particularly in the OP20-3 group. The value of mineralized surface of the OP groups was significantly higher than that of the OV group (P < 0.01), whereas the value of eroded surface of the OP groups was not significantly higher than that of the OV group. This study indicates that preventive and therapeutic intermittent administration of PTH in ovariectomized rats increase the bone formation in rat mandibular condyle without accelerating bone resorptive activity. This anabolic effect was best induced by the injection mode of 20 micrograms/kg three times per week.

Postnatal ontogeny of GTP binding protein in the human frontal cortex

The postnatal development of G protein in membrane preparations from frontal cortex regions in postmortem brains of various ages was investigated by immunoblotting with polyclonal antibodies against several specific G protein subtypes (the short and long form of Galphas(:Gs), Galphai1.2(:Gi), Galphao(:Go) and Galphaq/11(:Gq)) and tubulinbeta, and functional photoaffinity GTP binding. The amounts of Go showed steep increases at about 2 years, and there were similar tendency about Gs, Gi1.2 and Gq/11. Moreover, tubulinbeta was constant with development. The guanine nucleotide binding of Gs, Gi and Go also transiently increased at about the age of 2 years but the ratio of Gs to Gi.o was unchanged. Our results might have relevance for developmental neuroplasticity in signal transduction.

Effect of intravesical nitric oxide therapy on cyclophosphamide-induced cystitis

PURPOSE

This study was conducted to examine effects of nitric oxide (NO) donors on bladder hyperactivity induced by cyclophosphamide (CYP)-induced cystitis.

MATERIALS AND METHODS

Female Sprague-Dawley rats received a single intraperitoneal injection of CYP (100 mg./kg.), and then their micturition pattern including mean micturition volume and the number of micturitions during 24 hours was recorded in a metabolic cage before and after CYP treatment. Forty-eight hours after CYP injection, bladder function under urethane anesthesia was evaluated by cystometry with continuous saline infusion (0.04 ml. per minute) or under isovolumetric conditions (0.8 ml. bladder volume). NO donors, S-nitroso-N-acetyl-penicillamine (SNAP, 2 mM) or sodium nitroprusside (SNP, 1 mM), and an NO synthase (NOS) inhibitor, N-nitro-L-arginine methyl ester (L-NAME, 20 mM) were administered intravesically. Direct action of SNAP on bladder afferent neurons was also tested in a patch-clamp recording study.

RESULTS

The number of micturitions significantly increased during the first 24 hours after CYP injection (19.0 +/- 0.88 versus 92.1 +/- 16.3 micturitions/24 hours, mean +/- SE, n = 25) (p <0.001). There was no significant difference in total micturition volume before (12.3 +/- 1.0 ml./24 hours) and after CYP treatment (15.6 +/- 1.5 ml./24 hours). During continuous infusion cystometry, intercontraction interval (ICI) was smaller in CYP-injected rats than in control rats. In CYP-injected animals, NO donors increased the ICI, but did not change the amplitude of bladder contractions. Continuous intravesical infusion of the NOS inhibitor did not alter the cystometric parameters. During cystometry under isovolumetric conditions, contraction frequency was decreased after NO donor administration. NO donors did not influence bladder activity in control rats. In patch clamp recordings, when SNAP (500 microM) was directly applied to dissociated afferent neurons innervating the urinary bladder, high-voltage-activated Ca2+ channel currents were suppressed by approximately 30%.

CONCLUSIONS

Intravesical NO donors can suppress CYP-induced bladder hyperactivity. We hypothesize that the effect of NO donors is not due to smooth muscle relaxation, but rather due to an inhibitory effect on bladder afferent pathways that was manifested by an increase in intercontraction interval without changes in contraction amplitude. NO donors may be considered as a possible treatment of CYP-induced and other types of bladder inflammation.

Morphological characterization of skeletal cells in Cbfa1-deficient mice

To clarify the mechanisms by which core-binding factor-alpha1 (Cbfa1), an essential transcription factor in osteogenesis, functions in osteoblast matrix formation, as well as in chondrocyte differentiation and osteoclastic bone resorption, Cbfa1-deficient embryonic mice were investigated ultrastructurally and histocytochemically at 18.5 days postcoitum. In homozygotic mice, both endochondral and intramembranous ossification were arrested, although bone tissue had already formed at this stage in the wild type. The tibiae of homozygotic mice were characterized by calcified cartilage and alkaline phosphatase (ALP)-positive perichondrium, whereas membranous structures indicating the presence of ALP activity in the lateral portion were observed in the calvariae, rather than the bone tissue. Most of the ALP-positive perichondrial cells in homozygotic tibiae possessed a spindle-shaped cell contour and small cytoplasm, the extracellular matrix of which contained neither type I collagen nor calcifying matrix vesicles. In contrast, some perichondrial cells at the very middle part of tibiae became flattened. In the vicinity of these cells, a thin layer of type I collagen-based calcified matrix, containing osteopontin, bone sialoprotein, or osteocalcin, was observed. In the cartilage of mutant mice, we observed a hypoplasic zone of proliferative chondrocytes, the flattening of hypertrophic chondrocyte-like cells, and calcified chondrocytes which, while not degraded, did display a high level of cell function. Mononuclear osteoclastic cells were found in the perichondrium, near calcified chondrocytes, in mutant mice. Multinuclear osteoclasts possessing H+-ATPase and ruffled borders were also present, although only in limited numbers. Neither the development of ruffled borders nor intracellular polarization was complete. Because the majority of osteogenic cells in Cbfa1-deficient mice can neither form nor calcify the bone matrix, Cbfa1 principally plays essential roles in osteoblastic differentiation and bone matrix formation. Cbfa1 also affects both the proliferation and the differentiation of chondrocytes, whereas its absence prevents normal osteoclast formation and related functions.

Granulocyte-macrophage colony-stimulating factor gene transfer to dendritic cells or epidermal cells augments their antigen-presenting function including induction of anti-tumor immunity

Dendritic antigen-presenting cells derived from epidermis (Langerhans cells), bone marrow, and peripheral blood can present a wide variety of antigens, including tumor-associated antigens, for various immune responses. The development and function of dendritic cells is dependent upon a number of cytokines including granulocyte-macrophage-colony-stimulating factor. For example, Langerhans cells can present tumor-associated antigens for the induction of substantial in vivo anti-tumor immunity but only after activation in vitro by granulocyte-macrophage-colony-stimulating factor. Thus, we reasoned that insertion of a cDNA for granulocyte-macrophage-colony-stimulating factor into dendritic antigen-presenting cells may allow for autocrine stimulation and increased antigen-presenting capability. To test this possibility, we utilized an adenovirus vector to insert a cDNA for murine granulocyte-macrophage-colony-stimulating factor into the dendritic cell lines XS52-4D and XS106 (derived from neonatal mouse epidermis), bone marrow-derived dendritic cells, and epidermal cells that contain Langerhans cells. Infection of each of these cell types resulted in release of abundant quantities of granulocyte-macrophage-colony-stimulating factor. XS52-4D and XS106 cells infected with adenovirus granulocyte-macrophage-colony-stimulating factor exhibited prolonged dendrites and greater expression of major histocompatibility complex class II molecules and CD86 compared with cells infected with a null vector. Granulocyte-macrophage-colony-stimulating factor cDNA-containing XS cells, bone marrow-derived dendritic cells, and epidermal cells had more potent alloantigen presenting capability than cells infected with a null vector. Most importantly, granulocyte-macrophage-colony-stimulating factor gene-transferred epidermal cells were able to present tumor-associated antigens for in vivo anti-tumor immunity against challenge with the S1509a spindle-cell tumor whereas null vector-infected cells were unable to prime for immunity. These results suggest that introduction of a cDNA for granulocyte-macrophage-colony-stimulating factor into dendritic cells may be an effective means to augment their antigen-presenting capability and that granulocyte-macrophage-colony-stimulating factor gene-transfer- red epidermal cells may be useful in tumor vaccination strategies.

Novel polymorphisms in the upstream region of the human dopamine D4 receptor (DRD4) gene

We found nine novel polymorphisms in the upstream region of the human dopamine D4 receptor (DRD4) gene of Japanese by direct sequencing. These polymorphisms are -809G > A, -768G > A, -616C > G, -603T > del, -602G > del, -600G > C, -376C > T, -291C > T, and -128G > T. One known polymorphism, -521C > T, was also recognized. Six of these sites were identified as restriction fragment length polymorphisms (RFLPs).

beta-Endorphin binding and regulation of cytokine expression in Langerhans cells

Neuropeptides and neurohormones have been shown to be able to regulate cutaneous immune reactions. Binding of beta-endorphin (beta-end) on epidermal Langerhans cells (LC) and effects of beta-end on cytokine expression were examined. Biotinylated beta-end bound to the mouse LC-like cell line, XS52, and the binding was replaced with intact beta-end but not with substance P. beta-End augmented secretion of IL-1 beta and IL-10 from XS52 cells were induced by a combination of LPS and GM-CSF. Induction of TNF alpha was suppressed by beta-end. The regulation of cytokine expression was confirmed in fresh LC by RT-PCR. These results suggest that beta-end is a regulator of skin immune function.

Ultrastructural and cytochemical studies on cell death of osteoclasts induced by bisphosphonate treatment

The process of apoptosis and fate of osteoclasts are not well elucidated because dying osteoclasts are rarely seen in normal bone. Histological, cytochemical, and ultrastructural features of osteoclasts undergoing apoptosis were studied in the femur and tibia of rats treated with a third-generation bisphosphonate (disodium dihydrogen (cycloheptylamino)-methylene-1, 1-bisphosphonate). After the bisphosphonate administration, osteoclasts decreased significantly in number. Initially, they became devoid of ruffled borders and detached from the bone surface. In such osteoclasts, the Golgi apparatus was degraded, or dispersed in the cytoplasm. Later, osteoclasts revealed typical features of apoptosis, with pyknotic nuclei showing condensation and margination of heterochromatins and DNA fragmentation. They were often convoluted to give rise to apoptotic bodies. In addition, enlargement and fusion of nuclear envelopes and subsequent disruption leading to leakage of nuclear contents into the cytoplasm were observed in osteoclasts in the late stage of apoptosis. These osteoclasts as well as apoptotic bodies were surrounded by cytoplasmic processes of macrophages, which often contained degenerated cytoplasmic fragments of osteoclasts. Apoptotic osteoclasts migrating into or present in capillaries were also observed in some areas. In conclusion, bisphosphonate induces apoptosis of osteoclasts, which was characterized by ultrastructural changes of the nucleus typical of apoptosis accompanied by degradation of cell organelles. The majority of them are eliminated by macrophages, but there are some that escape into blood vessels.

Distribution of glucocorticoid receptor immunoreactivity in gastric mucosa of normal and adrenalectomized rats

Glucocorticoids have many effects in the stomach. It is well known that glucocorticoids function via the glucocorticoid receptor (GR). In this study, GR immunoreactivity in the gastric mucosa of normal and adrenalectomized (ADX) rats was examined immunohistochemically by using specific polyclonal antibodies against rat GR. In the gastric mucosa of normal rats, GR immunoreactivity was observed in the nuclei of morphologically identified parietal cells. Double immunohistochemical staining for GR and parietal cell, anti-parietal cell antibody-positive cells also had positive immunoreactions for GR. In the gastric mucosa of ADX rats, GR immunoreactivity was diminished in the nuclei of parietal cells but weak immunoreactivity was still observed. These results suggest that parietal cells in the gastric mucosa of rats are directly regulated by glucocorticoids via its receptors. Nuclear GR immunoreactivity in gastric parietal cells is thought to depend on the circulating ligands.