Cellular expression of retinal dehydrogenase types 1 and 2: effects of vitamin A status on testis mRNA

We examined expression of retinal dehydrogenase (RALDH) types 1 and 2 in liver and lung, and the effect of vitamin A status on testis expression by in situ hybridization. Liver expressed RALDH1 and RALDH2 only in stellate cells and hepatocytes, respectively. Lung expressed RALDH1 and RALDH2 throughout the epithelia of the airways, from the principal bronchi to the respiratory bronchiole. Vitamin A-sufficient rats expressed RALDH1 in spermatocytes, with less intense expression in spermatogonia and spermatids, and expressed RALDH2 in interstitial cells, spermatogonia, and spermatocytes. Neither Sertoli nor peritubular cells showed detectable RALDH1 or RALDH2 mRNA. Vitamin A deficiency produced a sevenfold increase in RALDH1 and a 70-fold decrease in RALDH2 mRNA in testis. In each case, the net change reflected extensive loss of germ cells, increased intensity of expression in residual germ cells, and expression in Sertoli and peritubular cells. Low-dose RA relatively early during vitamin A depletion supported spermatogenesis and affected expression of both RALDHs, but did not reinstate "vitamin A normal" expression patterns. These results show that: RALDH1 and RALDH2 have distinct mRNA expression patterns in multiple cell types in three vitamin A target tissues; RALDH expression occurs in cell types that express cellular retinol-binding protein and retinol dehydrogenase isozymes (except stellate cells, for which retinol dehydrogenase expression remains unknown); vitamin A deficiency and RA supplementation affects the loci and intensity of RALDH mRNAs in testis; and low-dose RA does not substitute completely for retinol. Overall, these data provide insight into the unique functions of RALDH1 and RALDH2 in retinoid metabolism.

Homing of in vitro-generated donor antigen-reactive CD4+ T lymphocytes to renal allografts is alpha 4 beta 1 but not alpha L beta 2 integrin dependent

The extravasation and sequestration of Ag-reactive T lymphocytes into vascularized organ allografts depend on a cascade of complex interactions among circulating lymphocytes, endothelial cells, and extracellular matrix proteins. Ag-activated donor-specific CD4 T cells are major initiators and effectors in the allograft rejection response. Interfering with the intragraft homing of activated CD4 T cells may represent a novel therapeutic approach in transplant recipients. We have developed a FACS-based short-term homing assay that allows tracing in vitro-generated Ag-reactive CD4 T cells after adoptive transfer in test rat recipients. Allospecific cell lines were preincubated with anti-alpha(4)beta(1) or anti-alpha(L)beta(2) mAb, because of enhanced expression of both integrin receptors after alloactivation. The pretreated Lewis(BN) lymphocytes were carboxyfluorescein diacetate succinimidyl ester labeled and adoptively transferred into Lewis rat recipients of Brown Norway kidney allografts. The injection of equal numbers of PKH-26-labeled untreated cells allowed quantitative comparison of both populations in the same animal. Ex vivo treatment with anti-alpha(4)beta(1) mAb diminished intragraft infiltration of adoptively transferred T cells by 85% in a donor-specific fashion. In contrast, treatment with anti-alpha(L)beta(2) mAb did not affect intragraft cell sequestration. Hence, blocking alpha(4)beta(1) integrin interactions represents a novel strategy in preventing local intragraft recruitment of Ag-reactive CD4 T cells in transplant recipients.

Detyrosinated (Glu) microtubules are stabilized by an ATP-sensitive plus-end cap

Many cell types contain a subset of long-lived, ‘stable’ microtubules that differ from dynamic microtubules in that they are enriched in post-translationally detyrosinated tubulin (Glu-tubulin). Elevated Glu tubulin does not stabilize the microtubules and the mechanism for the stability of Glu microtubules is not known. We used detergent-extracted cell models to investigate the nature of Glu microtubule stability. In these cell models, Glu microtubules did not incorporate exogenously added tubulin subunits on their distal ends, while >70% of the bulk microtubules did. Ca(2+)-generated fragments of Glu microtubules incorporated tubulin, showing that Glu microtubule ends are capped. Consistent with this, Glu microtubules in cell models were resistant to dilution-induced breakdown. Known microtubule end-associated proteins (EB1, APC, p150(Glued) and vinculin focal adhesions) were not localized on Glu microtubule ends. ATP, but not nonhydrolyzable analogues, induced depolymerization of Glu microtubules in cell models. Timelapse and photobleaching studies showed that ATP triggered subunit loss from the plus end. ATP breakdown of Glu microtubules was inhibited by AMP-PNP and vanadate, but not by kinase or other inhibitors. Additional experiments showed that conventional kinesin or kif3 were not involved in Glu microtubule capping. We conclude that Glu microtubules are stabilized by a plus-end cap that includes an ATPase with properties similar to kinesins.

[The protective effect of ligustrazine on optic nerve axons in rabbit eyes with continuous elevated IOP]

OBJECTIVE

To investigate the effects of ligustrazine on optic nerve axons in rabbit eyes with continuous elevated intraocular pressure (IOP).

METHOD

Thirty-six NZ rabbits with continuous elevated IOP induced by injection of alpha-chymotrypsin into anterior chamber were divided into two groups by randomization: treatment and control group. Ten mg/kg ligustrazine injected into the treatment group every day for 3 weeks began on the 7(th) day after IOP elevated continuously. The changes of conjunctival microcirculation and optic nerve axonal ultrastructure were observed at different time points.

RESULTS

The destruction of conjunctival microcirculation and axonal ultrastructure was milder in treatment group than that in the control group. In addition, the total number of axons and the percentage of axons in optic nerve area were higher, whereas the axonal diameter was smaller in the treatment group.

CONCLUSION

It is suggested that ligustrazine protect optic nerve axons from more damage induced by elevated IOP through improving ocular microcirculation.

The amoebapore superfamily

Amoebapores, synthesized by human protozoan parasites, form ion channels in target cells and artificial lipid membranes. The major pathogenic effect of these proteins is due to their cytolytic capability which results in target cell death. They comprise a coherent family and are homologous to other proteins and protein domains found in eight families. These families include in addition to the amoebapores (1) the saposins, (2) the NK-lysins and granulysins, (3) the pulmonary surfactant proteins B, (4) the acid sphingomyelinases, (5) acyloxyacyl hydrolases and (6) the aspartic proteases. These amoebapore homologues have many properties in common including membrane binding and stability. We note for the first time that a new protein, countin, from the cellular slime mold, Dictyostelium discoideum, comprises the eighth family within this superfamily. All currently sequenced members of these eight families are identified, and the structural, functional and phylogenetic properties of these proteins are discussed.

Regulatory cells potentiate the efficacy of IL-4 gene transfer by up-regulating Th2-dependent expression of protective molecules in the infectious tolerance pathway in transplant recipients

We have previously shown that the tolerant state in allograft recipients can be maintained and perpetuated by an "infectious" T cell-dependent regulatory mechanism. Hence, 1) treatment of LEW rats with RIB-5/2, a CD4 nondepleting mAb, produces indefinite survival of LBNF1 cardiac allografts; 2) donor-specific tolerance can be then transferred by spleen cells into new cohorts of test allograft recipients; and 3) putative regulatory CD4+ Th2-like cells are instrumental in this tolerance model. We now report on studies aimed at exposing mechanisms underlying the infectious tolerance pathway, with emphasis on the interactions between intragraft adenovirus-IL-4 gene transfer and systemic infusion of regulatory cells from tolerant hosts. Unlike individual treatment regimens, adjunctive therapy with adenovirus-IL-4 and suboptimal doses of regulatory spleen cells was strongly synergistic and extended donor-type test cardiac allograft survival to about 2 mo. RT-PCR-based expression of intragraft mRNA coding for IL-2 and IFN-gamma remained depressed, whereas that of IL-4 and IL-10 reciprocally increased selectively in the combined treatment group, data supported by ELISA studies. In parallel, only adjunctive treatment triggered intragraft induction of molecules with anti-oxidant (HO-1) and anti-apoptotic (Bcl-xL/Bag-1) but not with pro-apoptotic (CPP-32) functions, both in the early and late posttransplant phases. Hence, systemic infusion of regulatory cells potentiates the effects of local adenovirus-IL-4 gene transfer in transplant recipients. Th2-driven up-regulation of protective molecule programs at the graft site, such as of anti-oxidant HO-1 and/or anti-apoptotic Bcl-xL and Bag-1, may contribute, at least in part, to the maintenance of the infectious tolerance pathway in transplant recipients.

Fas ligand gene transfer prolongs rat renal allograft survival and down-regulates anti-apoptotic Bag-1 in parallel with enhanced Th2-type cytokine expression

BACKGROUND

Fas ligand (FasL) induces apoptosis of cells bearing Fas receptor, and may play a role in the acquisition of immune privilege. We have previously shown that adenovirus (Ad)-mediated FasL gene transfer significantly prolongs survival in a strongly major histocompatibility complex-incompatible rat kidney allograft model. This study analyzes putative mechanisms of FasL-mediated effects, with particular emphasis on Th1 and Th2 immune activation and Bag-1 expression, a Bcl-2-binding anti-apoptotic protein.

METHODS

Kidney transplants were performed in Wistar-Furth to Lewis rat combination. Donor kidneys were perfused in situ with Ad-FasL or Ad-beta-Gal, and then transplanted. Kidney allografts were harvested at days 2, 7, and 56 and were evaluated by hematoxylin and eosin and immunohistochemical staining. The expression of FasL, Bag-1, and Th1/Th2 cytokine genes was assessed by Northern blots, Western blots, and competitive template reverse-transcriptase polymerase chain reaction, respectively.

RESULTS

Intragraft expression of FasL was enhanced, whereas that of anti-apoptotic Bag-1 gene was diminished throughout, in Ad-FasL-transduced well-functioning renal allografts, compared with Ad-beta-Gal-treated rejecting controls. In parallel, the expression of mRNA coding for IL-2 and IFN-gamma remained depressed, whereas that of IL-4 and IL-10 reciprocally and progressively increased in the Ad-FasL animal group.

CONCLUSIONS

Prolonged survival in Ad-FasL-transduced rat renal allograft model correlates with down-regulation of Bag-1, a novel anti-apoptotic gene, and preferential Th2-type cytokine elaboration profile at the graft site. Because Th1-like cells are sensitive to FasL-mediated cytotoxic effects, T-cell apoptosis may preferentially spare Th2-like cells, with resultant prolonged graft survival.

LIGHT, a TNF-like molecule, costimulates T cell proliferation and is required for dendritic cell-mediated allogeneic T cell response

LIGHT is a recently identified member of the TNF superfamily and its receptors, herpesvirus entry mediator and lymphotoxin beta receptor, are found in T cells and stromal cells. In this study, we demonstrate that LIGHT is selectively expressed on immature dendritic cells (DCs) generated from human PBMCs. In contrast, LIGHT is not detectable in DCs either freshly isolated from PBMCs or rendered mature in vitro by LPS treatment. Blockade of LIGHT by its soluble receptors, lymphotoxin beta receptor-Ig or HVEM-Ig, inhibits the induction of DC-mediated primary allogeneic T cell response. Furthermore, engagement of LIGHT costimulates human T cell proliferation, amplifies the NF-kappaB signaling pathway, and preferentially induces the production of IFN-gamma, but not IL-4, in the presence of an antigenic signal. Our results suggest that LIGHT is a costimulatory molecule involved in DC-mediated cellular immune responses.

Retinoic acid regulates the morphological development of sympathetic neurons

Interactions between all-trans-retinoic acid (RA) and bone morphogenetic proteins (BMPs) affect the expression of neurotrophin receptors in sympathetic neurons (Kobayashi et al., 1998). In this study, we examined the possibility that similar interactions might regulate the morphological development of these neurons. Under control conditions, embryonic rat sympathetic neurons formed axons but not dendrites; cells exposed to RA had a similar appearance. Profuse dendritic growth was observed upon exposure to BMP-7, and this was reduced by approximately 70% by RA. This inhibitory effect of RA was mediated primarily by retinoic acid receptors (RARs) and it exhibited substantial specificity because it was not associated with changes in either axonal elongation or cell survival. Moreover, mRNAs for enzymes required for synthesis of RA were expressed in the sympathetic neurons and retinoid activity was released from superior cervical ganglia. These observations suggest that retinoids may function as endogenous morphogens and regulate neural cell shape and polarity in developing sympathetic ganglia.

beta1-adrenergic receptors mediate beta3-adrenergic-independent effects of CGP 12177 in brown adipose tissue

CGP 12177 is a beta-adrenergic receptor (AR) ligand that has been used to characterize the beta3-AR and the putative beta4-AR. The ability of CGP 12177 to activate beta1-AR when overexpressed in vitro and the presence of beta1-AR in tissues expressing putative beta4-AR prompted us to investigate the actions of CGP 12177 at recombinant and natively-expressed beta-AR. CGP 12177 potently activated recombinant rat and human beta1-AR expressed in Chinese hamster ovary cells. This activation, like that of putative beta4-AR, was resistant to blockade by selective and nonselective beta-AR antagonists. Brown fat has been proposed to contain beta4-AR, as evidenced by the presence of CGP 12177-mediated thermogenesis in mice lacking beta3-AR. Therefore, the identity of the receptors mediating CGP 12177 responses in brown fat was examined using wild-type mice and mice lacking beta1-AR or beta3-AR. In wild-type mice, CGP 12177 activated adenylyl cyclase via high- and low-affinity sites. The high-affinity site, but not the low-affinity site, was blocked by CGP 20712 with potency indicating an interaction with beta1-AR. Moreover, the high-affinity site was absent in mice lacking beta1-AR. In contrast, the low-affinity, CGP 20712-resistant activation by CGP 12177 was absent in mice lacking beta3-AR. Rather, activation occurred exclusively through the high-affinity, CGP 20712-sensitive site. These data indicate that the actions of CGP 12177 in brown fat that have been attributed to novel beta-AR (i.e., beta4-AR) are mediated via an atypical interaction with beta1-AR.

Synthesis and acetylcholinesterase inhibitory activity of huperzine A-E2020 combined compound

The synthesis of huperzine-E2020 combined compound (3) has been accomplished and the activities of 3 and the intermediates 12 and 13 to inhibit the activity of acetylcholinesterase have been measured. Conformation analyses and molecular docking studies of E2020 and the eight isomers of 12 were carried out. The results indicated that binding energies of all isomers of 12 with AChE was much lower than E2020 except for isomer RRZ, which might be the reason that the activity of 12 was lower than that of E2020. Interaction pattern of RRZ in AChE was also studied. Both binding energy and interaction pattern shows that the biological activity of RRZ might be higher than that of E2020.

What is the role of regulatory T cells in transplantation tolerance?

There has been considerable recent progress in the characterization of the regulatory T cells that mediate tolerance in a number of transplantation models. The conditions that facilitate the generation of regulatory T cells point to the thymus, the nature of immune suppression and the dose of immunosuppressive agent(s) being important. Putative mechanisms of immune regulation by regulatory T cells, particularly in the 'infectious' tolerance pathway, include Th2-type cytokines (IL-4, IL-10 and transforming growth factor beta) that may play a direct role as an indispensable requirement or may contribute indirectly as a favorable milieu for acquisition of tolerance. Anergic T cells may suppress immune responses via either cytokine competition or antigen-presenting cells. Models of autoimmune disease, in which regulatory T cells were shown to represent a distinct thymus-derived T cell subset, also suggest the role of antigen-presenting cells in mediating immune suppression. Progress has also been made in generating and characterizing regulatory T cells in vitro.

Reduced expression of p53 and cyclin A in intraductal mucin-hypersecreting neoplasm of the pancreas compared with usual pancreatic ductal adenocarcinoma

OBJECTIVE

Intraductal mucin-hypersecreting neoplasm (IMHN) of the pancreas, a slow-growing malignancy with a favorable prognosis, is distinctly categorized from the high-grade malignancy of the more common ductal adenocarcinoma. The aim of the present study was to clarify the molecular differences underlying the biological differences between IMHN and ductal adenocarcinoma of the pancreas.

METHODS

The expression of p53 and cyclin A in IMHN was compared with that in ductal adenocarcinoma of the pancreas immunohistochemically.

RESULTS

In IMHN, the incidence of p53 and cyclin A ascertained by positive nuclear staining was significantly lower than that in ductal adenocarcinoma. Furthermore, in ductal adenocarcinoma, p53 and cyclin A are topographically coexpressed.

CONCLUSIONS

These results suggest that the overexpression of p53 and cyclin A plays a role in the tumorigenesis of pancreatic ductal adenocarcinoma, and sparse expression of both antigens in IMHN may partly contribute to its low-grade malignant characteristics.

[The clinical significance of changes in plasma levels of alpha-granule membrane protein and D-dimer in patients with unstable angina]

OBJECTIVE

To explore the relationship between platelet activation and enhanced coagulability and the occurrence unstable angina.

METHODS

Plasma levels of a-granule membrane protein (GMP-140) and fibrin D-dimer were measured in 22 patients with unstable angina during the acute phase and after relief. The same procedure were compared with those in 20 control subjects and 18 patients with stable angina.

RESULTS

Plasma levels of GMP-140 and D-dimer were significantly higher in patients with unstable angina both during the acute phase (P < 0.01) and after the relief (P < 0.05) as compared with those in control subjects and patients with stable angina, but there was no significant difference between the latter two groups (P > 0.05). There was also no significant difference between the patients with unstable angina during the acute phase and after the relief (P > 0.05).

CONCLUSION

It is shown that activation of platelet and coagulation system combined with endothelial injury may play an important role in the development of unstable angina.

Reduced expression of p53 and cyclin A in intraductal mucin-hypersecreting neoplasm of the pancreas compared with usual pancreatic ductal adenocarcinoma

OBJECTIVE

Intraductal mucin-hypersecreting neoplasm (IMHN) of the pancreas, a slow-growing malignancy with a favorable prognosis, is distinctly categorized from the high-grade malignancy of the more common ductal adenocarcinoma. The aim of the present study was to clarify the molecular differences underlying the biological differences between IMHN and ductal adenocarcinoma of the pancreas.

METHODS

The expression of p53 and cyclin A in IMHN was compared with that in ductal adenocarcinoma of the pancreas immunohistochemically.

RESULTS

In IMHN, the incidence of p53 and cyclin A ascertained by positive nuclear staining was significantly lower than that in ductal adenocarcinoma. Furthermore, in ductal adenocarcinoma, p53 and cyclin A are topographically coexpressed.

CONCLUSIONS

These results suggest that the overexpression of p53 and cyclin A plays a role in the tumorigenesis of pancreatic ductal adenocarcinoma, and sparse expression of both antigens in IMHN may partly contribute to its low-grade malignant characteristics.

Inhibition of angiogenesis and breast cancer xenograft tumor growth by VEGI, a novel cytokine of the TNF superfamily

Recently, we reported a novel protein of the tumor necrosis factor (TNF) superfamily, named vascular endothelial cell growth inhibitor (VEGI), which is expressed predominantly in endothelial cells. When a secreted form of this new protein was overexpressed in mouse colon cancer cells, the growth of tumors formed by these cells in black mice was inhibited. We now report that recombinant VEGI inhibits the proliferation of endothelial cells but not that of other types of cells examined. The protein also inhibits formation of capillary-like structures by endothelial cells in collagen gels, and the growth of capillaries into collagen gels placed on the chick chorioallantoic membrane. The anticancer potential of VEGI was examined in a breast cancer xenograft tumor model in which the cancer cells were co-injected with Chinese hamster ovary cells overexpressing a secreted form of the protein. The co-injection resulted in potent inhibition of xenograft tumor growth. Our findings are consistent with the view that VEGI is an endothelial cell-specific negative regulator of angiogenesis.

Inhibition of angiogenesis and breast cancer xenograft tumor growth by VEGI, a novel cytokine of the TNF superfamily

Recently, we reported a novel protein of the tumor necrosis factor (TNF) superfamily, named vascular endothelial cell growth inhibitor (VEGI), which is expressed predominantly in endothelial cells. When a secreted form of this new protein was overexpressed in mouse colon cancer cells, the growth of tumors formed by these cells in black mice was inhibited. We now report that recombinant VEGI inhibits the proliferation of endothelial cells but not that of other types of cells examined. The protein also inhibits formation of capillary-like structures by endothelial cells in collagen gels, and the growth of capillaries into collagen gels placed on the chick chorioallantoic membrane. The anticancer potential of VEGI was examined in a breast cancer xenograft tumor model in which the cancer cells were co-injected with Chinese hamster ovary cells overexpressing a secreted form of the protein. The co-injection resulted in potent inhibition of xenograft tumor growth. Our findings are consistent with the view that VEGI is an endothelial cell-specific negative regulator of angiogenesis.

Identification and characterization of a novel cytokine, THANK, a TNF homologue that activates apoptosis, nuclear factor-kappaB, and c-Jun NH2-terminal kinase

By using the amino acid sequence motif of tumor necrosis factor (TNF), we searched the expressed sequence tag data base and identified a novel full-length cDNA encoding 285 amino acid residues and named it THANK. THANK is a type II transmembrane protein with 15-20% overall amino acid sequence homology to TNF, LT-alpha, FasL, and LIGHT, all members of the TNF family. The mRNA for THANK was expressed at high levels by peripheral blood leukocytes, lymph node, spleen, and thymus and at low levels by small intestine, pancreas, placenta, and lungs. THANK was also prominently expressed in hematopoietic cell lines. The recombinant purified protein expressed in the baculovirus system had an approximate molecular size 20 kDa with amino-terminal sequence of AVQGP. Treatment of human myeloid U937 cells with purified THANK activated nuclear transcription factor-kappaB (NF-kappaB) consisting of p50 and p65. Activation was time- and dose-dependent, beginning with as little as a 1 pM amount of the cytokines and as early as 15 min. Under the same conditions, THANK also activated c-jun NH2-terminal kinase (JNK) in U937 cells. THANK also strongly suppressed the growth of tumor cell lines and activated caspase-3. Although THANK had all the activities and potency of TNF, it did not bind to the TNF receptors. Thus our results indicate that THANK is a novel cytokine that belongs to the TNF family and activates apoptosis, NF-kappaB, and JNK through a distinct receptor.

Th1 and Th2 cytokines in organ transplantation: paradigm lost?

Identification of CD4+ T helper lymphocyte subsets that exhibit distinct cytokine elaboration patterns has provided a valuable framework for understanding the heterogeneity of the immune response. Much progress has been made in recent years in defining the cellular and molecular mechanisms by which cytokines induce T cell differentiation. In transplantation models, the Th1 cytokine profile often associates with allograft rejection, while the Th2 profile favors the acquisition of tolerance. However, this paradigm may not be sufficient to explain the recently demonstrated in vivo effects of cytokine manipulation on allograft survival. Th2 cytokines may not be necessary for tolerance induction, while Th1 cytokines may even be beneficial in promoting allograft survival. However, such data should be interpreted in light of the diverse and often redundant effects displayed by cytokine networks in vivo. Understanding the complex interactions of cytokines in the alloimmune cascade therefore is critical for designing therapeutic strategies that abrogate allograft rejection and induce donor-specific tolerance, an elusive goal in organ transplantation.

Two distinct mechanisms for inhibition of cell growth in human prostate carcinoma cells with antioxidant enzyme imbalance

The purpose of the present study was to determine whether manganese superoxide dismutase (MnSOD) overexpression in DU145 human prostate carcinoma cells affected cell reduction-oxidation state (cell redox) and to correlate changes in cell redox status with cell cycle progression and plating efficiency. One MnSOD-overexpressing cell line had no change in other antioxidant enzymes (AEs) (nonadapted clone), whereas a second MnSOD-overexpressing cell line studied had an increase in catalase (CAT) activity (adapted clone). Correlation of biochemical studies with cell cycle studies suggested that heteroploidy observed in the nonadapted MnSOD-overexpressing cell line may be due to increased intracellular peroxides with resultant disruption of the microtubule network, while a decreased mitotic rate was associated with decreased ATP levels in mitosis. In contrast, the decrease in cell growth in the adapted cell line was demonstrated to be due to a decrease in plating efficiency. Our results demonstrate complex effects of AE imbalance on cell growth of DU145 prostate cancer cells.

A newly identified member of tumor necrosis factor receptor superfamily (TR6) suppresses LIGHT-mediated apoptosis

TR6 (decoy receptor 3 (DcR3)) is a new member of the tumor necrosis factor receptor (TNFR) family. TR6 mRNA is expressed in lung tissues and colon adenocarcinoma, SW480. In addition, the expression of TR6 mRNA was shown in the endothelial cell line and induced by phorbol 12-myristate 13-acetate/ionomycin in Jurkat T leukemia cells. The open reading frame of TR6 encodes 300 amino acids with a 29-residue signal sequence but no transmembrane region. Using histidine-tagged recombinant TR6, we screened soluble forms of TNF-ligand proteins with immunoprecipitation. Here, we demonstrate that TR6 specifically binds two cellular ligands, LIGHT (herpes virus entry mediator (HVEM)-L) and Fas ligand (FasL/CD95L). These bindings were confirmed with HEK 293 EBNA cells transfected with LIGHT cDNA by flow cytometry. TR6 inhibited LIGHT-induced cytotoxicity in HT29 cells. It has been shown that LIGHT triggers apoptosis of various tumor cells including HT29 cells that express both lymphotoxin beta receptor (LTbetaR) and HVEM/TR2 receptors. Our data suggest that TR6 inhibits the interactions of LIGHT with HVEM/TR2 and LTbetaR, thereby suppressing LIGHT- mediated HT29 cell death. Thus, TR6 may play a regulatory role for suppressing in FasL- and LIGHT-mediated cell death.

[The examination of SIgE in perennial allergic rhinitis with mast allergy test system]

OBJECTIVE

To explore the relation between serum specificity immunoglobulin E (SIgE) and skin test (intracutaneous test) as well as nasal provocation in Perennial allergy rhinitis (PAR) by Mast Allergy Test System.

METHOD

Serum allergen-specific IgE (SIgE) were examined by Mast Allergy Test System in 57 case of PAR patients.

RESULT

The SIgE positive rate of fannae and pteronvssinus are highest (52.6%), the sensitive rate of intracutaneous test is 88.4% and nasal provocation is 88.9%. The SIgE positive rates of cludosporium, penicillum and altemana are 26.3%, 24.6% and 21.0%, respectively. The SIgE positive rates of fannae, cockroach, shrimp, crab, egg and milk is direct proportion with intracutaneous test (P < 0.01). Pteronvssiaus and pigweek mix have no relationship with intracutaneous test (P > 0.05). In addition, the positive rate of ragweed mix SIgE is 22.8%, but there is non of this plant in South China. It is worthy of paying attention in clinic.

CONCLUSION

It indicate that Mast Allergy Test System is one of the better examination for PAR allergens.

[A case-control study on relationship between body mass index and lung cancer in non-smoking women]

OBJECTIVE

To investigate the relationship between body mass index (BMI) and lung cancer in non-smoking women.

METHODS

A population-based case-control study on lung cancer in non-smoking women was conducted during February 1992 to December 1993 in Shanghai. Totally, 504 cases of lung cancer of non-smoking women and 601 population controls were studied.

RESULTS

The risk of lung cancer increased with the decrease of BMI. The odds ratio of lung cancer in non-smoking women was 1.95, as compared to controls with the highest quartile of their BMI, with a dose-response pattern (P < 0.0002 with chi(2) test for trend), adjusted for age, schooling and income. Non-conditional logistic regression analysis was used to adjust for some main risk factors found in other studies carried out at home, such as passive smoking, tea drinking, eye irritation by cooking oil fume, kinds of cooking oils, pulmonary tuberculosis, family history of lung cancer, age of menarche, menstrual cycle and dietary nutrition (including intake of vitamins C and E, beta-carotene, total fat and calorie), was used to adjust. There still existed relationship between BMI and lung cancer in non-smoking women after adjustment for those factors. Stratification analysis showed that there was relationship mainly between BMI and lung adenocarcinoma.

CONCLUSION

BMI may be a risk factor for lung cancer in non-smoking women.

VEGI, a novel cytokine of the tumor necrosis factor family, is an angiogenesis inhibitor that suppresses the growth of colon carcinomas in vivo

A novel member of the tumor necrosis factor (TNF) family has been identified from the human umbilical vein endothelial cell cDNA library, named vascular endothelial growth inhibitor (VEGI). The VEGI gene was mapped to human chromosome 9q32. The cDNA for VEGI encodes a protein of 174 amino acid residues with the characteristics of a type II transmembrane protein. Its amino acid sequence is 20-30% identical to other members of the TNF family. Unlike other members of the TNF family, VEGI is expressed predominantly in endothelial cells. Local production of a secreted form of VEGI via gene transfer caused complete suppression of the growth of MC-38 murine colon cancers in syngeneic C57BL/6 mice. Histological examination showed marked reduction of vascularization in MC-38 tumors that expressed soluble but not membrane-bound VEGI or were transfected with control vector. The conditioned media from soluble VEGI-expressing cells showed marked inhibitory effect on in vitro proliferation of adult bovine aortic endothelial cells. Our data suggest that VEGI is a novel angiogenesis inhibitor of the TNF family and functions in part by directly inhibiting endothelial cell proliferation. The results further suggest that VEGI maybe highly valuable toward angiogenesis-based cancer therapy.

Immunizing patients with metastatic melanoma using recombinant adenoviruses encoding MART-1 or gp100 melanoma antigens

BACKGROUND

The characterization of the genes encoding melanoma-associated antigens MART-1 or gp100, recognized by T cells, has opened new possibilities for the development of immunization strategies for patients with metastatic melanoma. With the use of recombinant adenoviruses expressing either MART-1 or gp100 to immunize patients with metastatic melanoma, we evaluated the safety, immunologic, and potential therapeutic aspects of these immunizations.

METHODS

In phase I studies, 54 patients received escalating doses (between 10(7) and 10(11) plaque-forming units) of recombinant adenovirus encoding either MART-1 or gp100 melanoma antigen administered either alone or followed by the administration of interleukin 2 (IL-2). The immunologic impact of these immunizations on the development of cellular and antibody reactivity was assayed.

RESULTS

Recombinant adenoviruses expressing MART-1 or gp100 were safely administered. One of 16 patients with metastatic melanoma receiving the recombinant adenovirus MART-1 alone experienced a complete response. Other patients achieved objective responses, but they had received IL-2 along with an adenovirus, and their responses could be attributed to the cytokine. Immunologic assays showed no consistent immunization to the MART-1 or gp100 transgenes expressed by the recombinant adenoviruses. High levels of neutralizing antibody were found in the pretreatment sera of the patients.

CONCLUSIONS

High doses of recombinant adenoviruses could be safely administered to cancer patients. High levels of neutralizing antibody present in patients' sera prior to treatment may have impaired the ability of these viruses to immunize patients against melanoma antigens.

Molecular characterization of human and rat RGS 9L, a novel splice variant enriched in dopamine target regions, and chromosomal localization of the RGS 9 gene

A novel splice variant of RGS 9 was isolated from a rat hypothalamus, human retina, and a human kidney (Wilm's) tumor. This variant, termed RGS 9L, differs from the retinal form (termed RGS 9S) identified previously in that it contains a 211- (rat) or 205- (human) amino acid proline-rich domain on the carboxyl terminus. The pattern of RGS 9 mRNA splicing was tissue specific, with striatum, hypothalamus- and nucleus accumbens expressing RGS 9L, whereas retina and pineal expressed RGS 9S almost exclusively. This pattern of mRNA splicing seemed to be highly conserved between human and rodents, suggesting cell-specific differences in the function of these variants. Transient expression of RGS 9L augmented basal and beta-adrenergic receptor-stimulated adenylyl cyclase activity while suppressing dopamine D2 receptor-mediated inhibition. Furthermore, RGS 9L expression greatly accelerated the decay of dopamine D2 receptor-induced GIRK current. These results indicate RGS 9L inhibits heterotrimeric Gi function in vivo, probably by acting as a GTPase-activating protein. The human RGS 9 gene was localized to chromosome 17 q23-24 by radiation hybrid and fluorescent in situ hybridization analyses. The RGS 9 gene is within a previously defined locus for retinitis pigmentosa (RP 17), a disease that has been linked to genes in the rhodopsin/transducin/cGMP signaling pathway.

High resolution analysis of DNA copy number variation using comparative genomic hybridization to microarrays

Gene dosage variations occur in many diseases. In cancer, deletions and copy number increases contribute to alterations in the expression of tumour-suppressor genes and oncogenes, respectively. Developmental abnormalities, such as Down, Prader Willi, Angelman and Cri du Chat syndromes, result from gain or loss of one copy of a chromosome or chromosomal region. Thus, detection and mapping of copy number abnormalities provide an approach for associating aberrations with disease phenotype and for localizing critical genes. Comparative genomic hybridization (CGH) was developed for genome-wide analysis of DNA sequence copy number in a single experiment. In CGH, differentially labelled total genomic DNA from a 'test' and a 'reference' cell population are cohybridized to normal metaphase chromosomes, using blocking DNA to suppress signals from repetitive sequences. The resulting ratio of the fluorescence intensities at a location on the 'cytogenetic map', provided by the chromosomes, is approximately proportional to the ratio of the copy numbers of the corresponding DNA sequences in the test and reference genomes. CGH has been broadly applied to human and mouse malignancies. The use of metaphase chromosomes, however, limits detection of events involving small regions (of less than 20 Mb) of the genome, resolution of closely spaced aberrations and linking ratio changes to genomic/genetic markers. Therefore, more laborious locus-by-locus techniques have been required for higher resolution studies. Hybridization to an array of mapped sequences instead of metaphase chromosomes could overcome the limitations of conventional CGH (ref. 6) if adequate performance could be achieved. Copy number would be related to the test/reference fluorescence ratio on the array targets, and genomic resolution could be determined by the map distance between the targets, or by the length of the cloned DNA segments. We describe here our implementation of array CGH. We demonstrate its ability to measure copy number with high precision in the human genome, and to analyse clinical specimens by obtaining new information on chromosome 20 aberrations in breast cancer.

LIGHT, a novel ligand for lymphotoxin beta receptor and TR2/HVEM induces apoptosis and suppresses in vivo tumor formation via gene transfer

LIGHT is a new member of tumor necrosis factor (TNF) cytokine family derived from an activated T cell cDNA library. LIGHT mRNA is highly expressed in splenocytes, activated PBL, CD8(+) tumor infiltrating lymphocytes, granulocytes, and monocytes but not in the thymus and the tumor cells examined. Introduction of LIGHT cDNA into MDA-MB-231 human breast carcinoma caused complete tumor suppression in vivo. Histological examination showed marked neutrophil infiltration and necrosis in LIGHT expressing but not in the parental or the Neo-transfected MDA-MB-231 tumors. Interferon gamma (IFNgamma) dramatically enhances LIGHT-mediated apoptosis. LIGHT protein triggers apoptosis of various tumor cells expressing both lymphotoxin beta receptor (LTbetaR) and TR2/HVEM receptors, and its cytotoxicity can be blocked specifically by addition of a LTbetaR-Fc or a TR2/HVEM-Fc fusion protein. However, LIGHT was not cytolytic to the tumor cells that express only the LTbetaR or the TR2/HVEM or hematopoietic cells examined that express only the TR2/HVEM, such as PBL, Jurkat cells, or CD8(+) TIL cells. In contrast, treatment of the activated PBL with LIGHT resulted in release of IFNgamma. Our data suggest that LIGHT triggers distinct biological responses based on the expression patterns of its receptors on the target cells. Thus, LIGHT may play a role in the immune modulation and have a potential value in cancer therapy.

Modulation of alloimmunity to major histocompatibility complex class I by cotransfer of cytokine genes in vivo

Major histocompatibility complex (MHC) class I antigen is a potent stimulus for alloimmune responses and is the principal immunologic target mediating acute cellular rejection of allografts. Using a method of direct in vivo gene transfer of cDNA encoding donor type MHC class I, we showed in a rat model that recipient muscle could express the transferred MHC class I cDNA, resulting in alloimmunization of the recipient. This was most graphically demonstrated by accelerated rejection of cardiac allografts expressing the same MHC class I as encoded by the immunizing cDNA. We now report the use of the particle-mediated gene transfer via a gene gun (Geneva, Middleton, WI, USA) to transfer MHC class I, as well as cytokine gene expression vectors, into rat skin. Compared to intramuscular injection, gene gun transfer to skin resulted in more efficient immunization. Donor-specific cytotoxic T lymphocyte (CTL) responsiveness and antibody levels increased. Furthermore, coexpression of certain cytokine genes with the MHC class I cDNA modulated the immune response. Specifically, coimmunization with IL-10 cDNA abrogated immunity to allo-MHC class I, while coimmunization with GM-CSF cDNA enhanced it. The influence of expression of these genes in skin was demonstrated by alteration of donor cardiac allograft survival. This model is useful for induction and modulation of alloimmune responses and may be used to develop gene therapy strategies to modify them.

Reduced expression of calponin h1 in leiomyosarcoma of the uterus

To determine the genetic differences between various smooth muscle tumors of the uterus, the expression of calponin h1 (cytoskeletal protein) was examined in normal myometrium and in smooth muscle tumors of the uterus (leiomyosarcoma, smooth muscle tumors of uncertain malignant potential, cellular leiomyoma, bizarre leiomyoma, and ordinary leiomyoma) using immunohistochemistry and Western blotting. Analysis of calponin h1 transcripts using the reverse-transcription-PCR was also performed. Immunohistochemically, calponin h1 was expressed in normal myometrium and in all leiomyomas; however, its expression was markedly weaker in leiomyosarcoma. The results of both Western blotting and the analysis of calponin h1 transcripts were compatible with the immunohistochemical results. It is suggested that reduced expression of calponin h1 is associated with leiomyosarcoma of the uterus, and that calponin h1 expression may serve as a valuable molecular maker in the differential diagnosis of smooth muscle tumors of the uterus.

Two distinct forms of soluble MHC class I molecules synthesized by different mechanisms in normal rat cells in vitro

Rat soluble MHC class I synthesis was studied at both RNA and protein levels to determine whether multiple forms of soluble MHC class I molecules are produced by different mechanisms. RT-PCR and sequencing of MHC class I transcripts identified an alternatively spliced nonclassical MHC class I gene product, lacking both exon 5 and 6, in both spleen and liver. Immunoprecipitation and SDS-PAGE identified two distinct soluble MHC class I proteins in both splenocyte- and hepatocyte-culture supernatants. The 36Kd classical soluble MHC class I protein (RT1.Aa) was precipitated by both allele-specific (MN4.91.6, R3/13, R2/15S) and pan-reactive (OX18) mAbs. The 39Kd non-RT1.A soluble MHC class I protein was precipitated only by OX18. The production of soluble RT1.Aa was inhibited by a metalloproteinase inhibitor, but not by serine/thiol protease inhibitors. None of these protease inhibitors interfered with the soluble non-RT1.A production, suggesting that it might be derived from an alternatively spliced MHC class I transcript. The soluble non-RT1.A was always associated with beta2m. However, soluble RT1.Aa molecule was cleaved in beta2m-free form and was reassociated with beta2m in culture supernatants. Thus two soluble MHC class I molecules, classical (36Kd RT1.Aa) and nonclassical (the alternatively spliced transcript), were produced from rat cells. Alternative splicing led to the nonclassical soluble MHC class I synthesis. Proteolytic cleavage by metalloproteinase led to the classical soluble MHC class I synthesis.

TRANK, a novel cytokine that activates NF-kappa B and c-Jun N-terminal kinase

We searched the expressed sequence tag database using sequence homology and identified a novel cytokine, which we have named TRANK (thioredoxin peroxidase-related activator of NF-kappa B and c-Jun N-terminal kinase). The predicted amino acid sequence of TRANK was highly homologous to that of the thiol-specific antioxidant proteins. Unlike these proteins, however, TRANK had a putative secretory signal polypeptide and was found to be secreted by cells. TRANK was expressed in most tissues and cell lines, and the gene that encodes it was mapped to chromosome Xp21-22.1. TRANK activated NF-kappa B and induced the degradation of the inhibitory subunit of NF-kappa B. In addition, TRANK up-regulated the expression of NF-kappa B-dependent gene products, ICAM-1, and inducible nitric oxide synthase. TRANK also activated c-Jun N-terminal kinase and induced the proliferation of normal human foreskin fibroblasts. Its homology with antioxidant proteins, wide distribution in tissues, and ability to activate NF-kappa B and c-Jun N-terminal kinase suggest that TRANK plays an important role in inflammation.

[Psychological study of parameter selection for Chinese speech warning]

To study the effects of the parameters of Chinese speech warning on cognitive property, and to obtain the optimal parameters in accordance with cognitive property, experiments of cognitive property for Chinese speech warning was carried out in 20 healthy males. Combining our study on the sensation-reaction time, the optimal parameters in accordance with space ergonomics [correction of ergonormics] and cognitive property were determined: suitable time length of prewarning sound is 0.35 approximately 0.55 s; prewarning interval is 0.3-0.4 s; interval between sentences is 0.3-0.4 s; word number of warning sentence < or = 7. The result can serve as the objective ergonomical basis for the design of Chinese speech warning system in manned space vehicle, and as the evaluation criterion.

Agonist interactions with chimeric and mutant beta1- and beta3-adrenergic receptors: involvement of the seventh transmembrane region in conferring subtype specificity

beta1- and beta3-adrenergic receptors (AR) are the predominant beta-AR subtypes in adipocytes, and analysis of native and recombinant beta-AR has revealed several pharmacological and biochemical differences between these subtypes. This study used chimeric and mutated rat beta-AR expressed in Chinese hamster ovary cells to examine the basis of certain characteristic differences in the agonist properties of catecholamines and prototypic beta3-AR agonists. The exchange of sequence beyond transmembrane (TM) region 6 between the beta-AR subtypes had dramatic and reciprocal effects on the affinity and efficacy of the prototypic beta3-AR agonists BRL 37,344 and CL 316,243, without affecting the interactions with catecholamines. Mutation of Phe350 and Phe351 in TM7 of the beta1-AR to Ala and Leu found in the beta3-AR was sufficient to allow activation by prototypic beta3-AR agonists. Interestingly, this mutation did not affect catecholamine action and it did not impair the ability of propranolol to block the actions of isoproterenol or the selective beta3-AR agonists. beta1-AR containing beta3-AR sequence from predicted TM5 through TM6 exhibited reduced affinity for catecholamines without altering agonist potency, suggesting enhanced coupling efficiency. Inclusion of the homologous beta1-AR sequence in the beta3-AR, however, did not produce reciprocal effects. These results are the first to define a major determinant of beta3-AR subtype-selective agonism in TM7 and demonstrate that the determinants of selective phenethanolamines, catecholamines, and propranolol action are distinct.

Recombinant adenovirus encoding gp100 modulates experimental melanin-protein induced uveitis (EMIU)

Experimental melanin-protein induced uveitis (EMIU) is a T-cell mediated autoimmune uveitis induced by immunization with bovine uveal melanin protein. Gp100, a melanocyte lineage-specific protein, is identified as a human melanoma antigen. A recombinant adenovirus construct encoding gp100 (Ad2CMV-gp100) has been used as a vaccine for cancer therapy. This study examines the effect of Ad2CMV-gp100 on EMIU. To induce EMIU, rats were injected intraperitoneally on day 7 before immunization with ad2CMV-gp100, control adenovirus encoding LacZ (Ad2CMV-LacZ), or no virus. On day 21 after immunization, the right eye was processed for histology and the left eye was analysed for cytokines by quantitative reverse transcriptase-polymerase chain reaction. Western blot analysis showed that uveal melanin-protein contains gp100. In three independent experiments, ocular inflammation was significantly suppressed, and expression of ocular IL-12p40 mRNA was much lower in the rats which received Ad2CMV-gp100 before immunization than in those that received Ad2CMV-LacZ or no virus. No abnormalities developed in rats which received Ad2CMV-gp100 or Ad2CMV-LacZ alone. Therefore, Ad2CMV-gp100 injection prevents the development of EMIU, at least in part, through cytokine regulation.

[The analysis of donkey-hide glue, antler glue and tortoise shell glue by means of circular dichroism]

Donkey-hide glue, antler glue, tortoise shell glue and their forgeries were identified by the analysis method of circular dichroism(CD) in this paper. The standard spectra and data were set up. The method is simple, fast and accurate.

[Identification of powdered Bungarus multieinctus Blyth and its adulterants]

This paper reports the results of identification of powdered Bungarus muliteinctus and its adulterants (Natrix annularis; Dinodon rufozonatum and Bungarus fascitus). A comparative table of and a key to the characteristics are given.

[A study on EEG-Encephalofluctuographic characteristics in alpha frequency band in pilots]

The frequency-fluctuation characteristics in alpha frequency band were studied by EEG-Encephalofluctuographic Technology (EEG-ET) in 261 pilots. The electrical activity was recorded from 12 scalp monopolar leads of the international 10-20 system using linked ear lobes as reference. The components of the competitive frequency-fluctuation structure in alpha frequency band was analysed. The results showed that the predominant frequency component of the competitive structure was 9 Hz in the 261 normal healthy pilots. The second was 10 Hz. And the third was 7 Hz. The other competitive frequency components were inhibited. The relative entropy value (percentage) of the competivity structure was calculated for each EEG derivation of each pilot. We also analysed the spectra of the EEG-Encephalofluctuograph. We found that there was a dominant power peak at 21.39mHz in 57 pilots who complained in-flight blackout sometimes during acceleration.

[Ergonomical study on Chinese speech warning]

Ergonomical experiments on speech warning under noise background were carried out in 40 healthy males, aged 20-33. Through the determination of auditory reaction time to the Chinese speech warning under dual-tasks and the subjective evalution of the suitable time length of main warning voice by the subject, the optimum parameters of Chinese speech warning in accordance with space ergonomics were determined. It was found that: suitable time length of main warning voice is 0.35-0.55s, main interval is 0.15-0.35s, speech speed is 4-6 word/s, and sentence interval is 0.2-0.4s. Meanwhile, the analysis of heart rate (HR) and heart rate variability (HRV) demonstrated that the speech warning using aforementioned parameters didn't increase the operator's work load. The results can serve as the objective ergonomical basis and the evaluation criterion for design of speech warning in manned space vehicle.

cDNA cloning and characterization of a cis-retinol/3alpha-hydroxysterol short-chain dehydrogenase

We report a mouse cDNA that encodes a 317-amino acid short-chain dehydrogenase which recognizes as substrates 9-cis-retinol, 11-cis-retinol, 5alpha-androstan-3alpha,17beta-diol, and 5alpha-androstan-3alpha-ol-17-one. This cis-retinol/androgen dehydrogenase (CRAD) shares closest amino acid similarity with mouse retinol dehydrogenase isozymes types 1 and 2 (86 and 91%, respectively). Recombinant CRAD uses NAD+ as its preferred cofactor and exhibits cooperative kinetics for cis-retinoids, but Michaelis-Menten kinetics for 3alpha-hydroxysterols. Unlike recombinant retinol dehydrogenase isozymes, recombinant CRAD was inhibited by 4-methylpyrazole, was not stimulated by ethanol, and did not require phosphatidylcholine for optimal activity. CRAD mRNA was expressed intensely in kidney and liver, in contrast to retinol dehydrogenase isozymes, which show strong mRNA expression only in liver. CRAD mRNA expression was widespread (relative abundance): kidney (100) > liver (92) > small intestine (9) = heart (9) > retinal pigment epithelium and sclera (4.5) > brain (2) > retina and vitreous (1.6) > spleen (0.7) > testis (0.6) > lung (0.4). CRAD may catalyze the first step in an enzymatic pathway from 9-cis-retinol to generate the retinoid X receptor ligand 9-cis-retinoic acid and/or may regenerate dihydrotestosterone from its catabolite 5alpha-androstan-3alpha,17beta-diol. These data also illustrate the multifunctional nature of short-chain dehydrogenases and provide a potential mechanism for androgen-retinoid interactions.

Immunohistochemical analysis of the expression of cdk4 and p16INK4 in human endometrioid-type endometrial carcinoma

BACKGROUND

Abnormalities in G1 cell cycle regulation have been associated with the malignant transformation of cells. To obtain further information about the role of factors regulating the G1 cell cycle in the development of endometrial carcinoma, the authors analyzed the expression of cdk4 (cyclin-dependent kinase) and p16INK4 (an inhibitor of cdk4).

METHODS

Immunohistochemical staining was performed on 20 specimens of normal endometria and 41 specimens of endometrioid-type endometrial carcinoma using antibodies against cdk4 and p16INK4.

RESULTS

In the glandular epithelia of the normal endometria, cytoplasmic staining of cdk4 and p16INK4 was observed only in the proliferative phase, but nuclear staining of these agents was negligible. In endometrial carcinomas, 8 (19.5%) and 14 (34.2%) were positive for cdk4 and p16INK4 in the nucleus, respectively. Topographically, the nuclear cdk4 positive tumor cells were negative for p16INK4 and the nuclear p16INK4 positive tumor cells were found in areas without nuclear cdk4 expression, suggesting an inverse correlation between the two agents. In addition, the poorly differentiated carcinomas were more frequently positive for nuclear cdk4 than were the highly differentiated carcinomas (P = 0.03).

CONCLUSIONS

These data suggest that increased expression of nuclear cdk4 associated with loss of p16INK4 expression could be involved in the carcinogenesis of a subset of endometrial carcinomas.

Coexpression of the mRNAs encoding retinol dehydrogenase isozymes and cellular retinol-binding protein

We used in situ hybridization of adult rat tissue to show that mRNAs encoding cellular retinol-binding protein (CRBP) and retinol dehydrogenase (RoDH) isozymes I/III and II were expressed in hepatocytes uniformly throughout the liver lobule, but were absent from Kupffer cells and endothelial cells of blood vessels and bile ducts. In kidney, CRBP, RoDH(I), and RoDH(II) were found in the proximal tubules of the cortex. Distal tubules, Henle's loops, collecting ducts, and glomeruli showed little, if any, expression. In testis, CRBP, RoDH(I), and RoDH(II) were found in Sertoli cells. Expression, albeit weaker, also occurred in spermatogonia and primary spermatocytes. Peritubular cells and other germ cells had even weaker expression. Only CRBP and RoDH(II) mRNA were detected in interstitial cells. In lung CRBP, RoDH(I) and RoDH(II) were expressed most intensely in the epithelium of the bronchi and bronchioli, but also occurred in the simple columnar epithelial cells of the alveolar duct and in alveolar type II cells. These data are consistent with the hypothesis that holo-CRBP serves as substrate for retinoic acid biosynthesis because they show that the substrate and the enzyme occur in the same cellular loci in vivo. These data also indicate that multiple cellular sites of retinoic acid biosynthesis occur throughout tissues. Also, the general concordance between mRNA localization and CRBP expression patterns, revealed by previous immunocytochemistry studies, supports and extends the conclusion that CRBP mRNA expression correlates with CRBP expression, based earlier on comparing RNA assays with radioimmunoassays.

Arotinoid mofarotene (RO40-8757) up-regulates p21 and p27 during growth inhibition of pancreatic cancer cell lines

Effective chemotherapy for pancreatic cancer is urgently needed. The anti-proliferative activity of a new retinoid, mofarotene (RO40-8757), was compared with that of other retinoids, such as all trans-retinoic acid, 13-cis retinoic acid and 9-cis retinoic acid, on 9 pancreatic cancer cell lines in relation to the effects on various cell cycle-regulating factors. After treatment with each retinoid, anti-proliferative effect was determined by the MTT method and expression of cell cycle-regulating factors, such as cyclins (D1, E and A), cyclin-dependent kinases (2 and 4), cyclin-dependent kinase inhibitors (p21 and p27) and retinoblastoma protein, was analyzed by Western blotting. Mofarotene showed half-maximal inhibition of cell proliferation at concentrations between 0.14 x 10(-6) and 3.8 x 10(-6) mol/l with little cytotoxicity. In contrast, the other retinoids did not inhibit the growth of all cell lines by over 50% compared to controls. A marked increase in the fraction of cells in G1 phase of the cell cycle was observed after mofarotene treatment; this was associated with marked up-regulation of p21/p27 and a shift of retinoblastoma protein into the hypophosphorylated form. In conclusion, mofarotene inhibits the growth of pancreatic cancer cells by inducing G1-phase cell cycle-inhibitory factors (p21, p27 and hypophosphorylated form of Rb protein) and is considered to be a useful agent for pancreatic cancer treatment.

Direct MHC class I complementary DNA transfer to thymus induces donor-specific unresponsiveness, which involves multiple immunologic mechanisms

Our purposes were 1) to determine whether direct transfer of cDNA encoding allogeneic MHC class I Ag to the rat thymus would be capable of inducing donor-specific unresponsiveness and 2) to study the immunologic mechanism of this effect. Plasmid DNA encoding donor strain (ACI-RT1.Aa) MHC class I Ag was directly injected into Lewis (RT1(l)) rat recipient thymus 7 to 10 days before ACI liver transplantation. A single dose of anti-lymphocyte serum was given i.p. on the day of thymic injection. Rats injected intrathymically with plasmid DNA and treated with anti-lymphocyte serum demonstrated prolonged survival in 9 of 13 rats (&gt;100 days). PCR was used to demonstrate that RT1.Aa cDNA was expressed in thymus transiently and later appeared in spleen. CTL limiting dilution assays showed that CTL precursor frequency was decreased in tolerant liver recipients. To test the hypothesis of clonal deletion vs anergy, CTL limiting dilution assays cultures were restimulated with donor cells and IL-2 to reverse anergy. Restimulation caused CTL precursor frequency to return to near normal in only one of five tolerant rats, suggesting clonal deletion or a dense anergic state. Passive transfer of splenocytes from tolerant rats to naive recipients prolonged cardiac allograft survival, suggesting that suppressor-type cells may also contribute to thymic tolerance in our model. In summary, our data suggest that donor MHC class I Ag expressed in thymus by direct DNA injection, followed by liver allografting, results in donor-specific unresponsiveness. The mechanism of this effect is complex, involving multiple immunologic mechanisms.

Direct MHC class I complementary DNA transfer to thymus induces donor-specific unresponsiveness, which involves multiple immunologic mechanisms

Our purposes were 1) to determine whether direct transfer of cDNA encoding allogeneic MHC class I Ag to the rat thymus would be capable of inducing donor-specific unresponsiveness and 2) to study the immunologic mechanism of this effect. Plasmid DNA encoding donor strain (ACI-RT1.Aa) MHC class I Ag was directly injected into Lewis (RT1(l)) rat recipient thymus 7 to 10 days before ACI liver transplantation. A single dose of anti-lymphocyte serum was given i.p. on the day of thymic injection. Rats injected intrathymically with plasmid DNA and treated with anti-lymphocyte serum demonstrated prolonged survival in 9 of 13 rats (>100 days). PCR was used to demonstrate that RT1.Aa cDNA was expressed in thymus transiently and later appeared in spleen. CTL limiting dilution assays showed that CTL precursor frequency was decreased in tolerant liver recipients. To test the hypothesis of clonal deletion vs anergy, CTL limiting dilution assays cultures were restimulated with donor cells and IL-2 to reverse anergy. Restimulation caused CTL precursor frequency to return to near normal in only one of five tolerant rats, suggesting clonal deletion or a dense anergic state. Passive transfer of splenocytes from tolerant rats to naive recipients prolonged cardiac allograft survival, suggesting that suppressor-type cells may also contribute to thymic tolerance in our model. In summary, our data suggest that donor MHC class I Ag expressed in thymus by direct DNA injection, followed by liver allografting, results in donor-specific unresponsiveness. The mechanism of this effect is complex, involving multiple immunologic mechanisms.

A role for mitogen-activated protein kinase in the spindle assembly checkpoint in XTC cells

The spindle assembly checkpoint prevents cells whose spindles are defective or chromosomes are misaligned from initiating anaphase and leaving mitosis. Studies of Xenopus egg extracts have implicated the Erk2 mitogen-activated protein kinase (MAP kinase) in this checkpoint. Other studies have suggested that MAP kinases might be important for normal mitotic progression. Here we have investigated whether MAP kinase function is required for mitotic progression or the spindle assembly checkpoint in vivo in Xenopus tadpole cells (XTC). We determined that Erk1 and/or Erk2 are present in the mitotic spindle during prometaphase and metaphase, consistent with the idea that MAP kinase might regulate or monitor the status of the spindle. Next, we microinjected purified recombinant XCL100, a Xenopus MAP kinase phosphatase, into XTC cells in various stages of mitosis to interfere with MAP kinase activation. We found that mitotic progression was unaffected by the phosphatase. However, XCL100 rendered the cells unable to remain arrested in mitosis after treatment with nocodazole. Cells injected with phosphatase at prometaphase or metaphase exited mitosis in the presence of nocodazole-the chromosomes decondensed and the nuclear envelope re-formed-whereas cells injected with buffer or a catalytically inactive XCL100 mutant protein remained arrested in mitosis. Coinjection of constitutively active MAP kinase kinase-1, which opposes XCL100's effects on MAP kinase, antagonized the effects of XCL100. Since the only known targets of MAP kinase kinase-1 are Erk1 and Erk2, these findings argue that MAP kinase function is required for the spindle assembly checkpoint in XTC cells.

Selective up-regulation of alpha1a-adrenergic receptor protein and mRNA in brown adipose tissue by neural and beta3-adrenergic stimulation

Previous studies have shown that neural stimulation of brown adipose tissue (BAT) reorganizes the expression and activity of signaling proteins in the beta-adrenergic adenylyl cyclase pathway. Cold stress increases neural stimulation of BAT and increases alpha1-adrenergic receptor number; however, the alpha1 receptor subtype involved and the mechanism of up-regulation by cold stress have not been determined. Using reverse transcription/polymerase chain reaction analysis and nuclease protection assay, BAT was demonstrated to express mRNAs encoding alpha1a and alpha1d, but not alpha1b, receptors. Parallel pharmacologic studies of BAT membranes and recombinant alpha1a and alpha1d receptors expressed in COS-7 cells demonstrated that alpha1a receptors predominate in BAT. Exposure of rats to 4 degrees for 4 days increased alpha1a receptors and mRNA in BAT but did not alter expression of alpha1d receptors or mRNA. The induction of alpha1a receptor and mRNA level by cold stress was prevented by selective surgical denervation of BAT. Furthermore, alpha1a receptor and mRNA expression could be induced in warm-adapted rats by infusions of the selective beta3-adrenergic receptor agonist CL 316,243. These data indicate that neural activation of beta3-adrenergic receptors is an important determinant of alpha1a adrenergic receptor expression in BAT.