Requirement for NF-kappaB in osteoclast and B-cell development

NF-kappaB is a family of related, dimeric transcription factors that are readily activated in cells by signals associated with stress or pathogens. These factors are critical to host defense, as demonstrated previously with mice deficient in individual subunits of NF-kappaB. We have generated mice deficient in both the p50 and p52 subunits of NF-kappaB to reveal critical functions that may be shared by these two highly homologous proteins. We now demonstrate that unlike the respective single knockout mice, the p50/p52 double knockout mice fail to generate mature osteoclasts and B cells, apparently because of defects that track with these lineages in adoptive transfer experiments. Furthermore, these mice present markedly impaired thymic and splenic architectures and impaired macrophage functions. The blocks in osteoclast and B-cell maturation were unexpected. Lack of mature osteoclasts caused severe osteopetrosis, a family of diseases characterized by impaired osteoclastic bone resorption. These findings now establish critical roles for NF-kappaB in development and expand its repertoire of roles in the physiology of differentiated hematopoietic cells.

Rescue of osteoclast function by transgenic expression of kinase-deficient Src in src-/- mutant mice

The Src tyrosine kinase has been implicated in a wide variety of signal transduction pathways, yet despite the nearly ubiquitous expression of c-src, src-/- mice show only one major phenotype-osteopetrosis caused by an intrinsic defect in osteoclasts, the cells responsible for resorbing bone. To explore further the role of Src both in osteoclasts and other cell types, we have generated transgenic mice that express the wild-type and mutated versions of the chicken c-src proto-oncogene from the promoter of tartrate resistant acid phosphatase (TRAP), a gene that is expressed highly in osteoclasts. We demonstrate here that expression of a wild-type transgene in only a limited number of tissues can fully rescue the src-/- phenotype. Surprisingly, expression of kinase-defective alleles of c-src also reduces osteopetrosis in src-/- animals and partially rescues a defect in cytoskeletal organization observed in src-/- osteoclasts. These results suggest that there are essential kinase-independent functions for Src in vivo. Biochemical examination of osteoclasts from these mice suggest that Src may function in part by recruiting or activating other tyrosine kinases.

QSAR models for binding of estrogenic compounds to estrogen receptor alpha and beta subtypes

We have developed Quantitative Structure-Activity Relationship (QSAR) models based on Comparative Molecular Field Analysis (CoMFA) for 31 estrogenic chemicals whose relative binding affinity (RBA) is available for both ER-alpha and ER-beta. The models demonstrated a significant correlation (r2>0.95) between the CoMFA-calculated steric/electrostatic fields and corresponding RBA data and a good predictive capability (q2>0.6) based on cross-validation. The CoMFA models and contour plots obtained for ER-alpha and ER-beta suggest a close similarity between the receptors in terms of mode of binding and provide a rational basis for ligand selectivity.

Antitumor activity of the novel human breast cancer growth inhibitor, mammary-derived growth inhibitor-related gene, MRG

A novel human tumor growth inhibitor was identified by differential cDNA sequencing. The predicted amino acid sequence of this tumor-suppressing factor has a significant sequence homology to mouse mammary-derived growth inhibitor and thus was named mammary-derived growth inhibitor-related gene (MRG). MRG was found to be expressed in normal and benign human breast tissues but not in breast carcinomas. In situ hybridization analysis demonstrated a stage-specific MRG expression as follows. MRG was barely detectable in breast carcinomas, showed partial and weak expression in benign hyperplasia, but was expressed at a high level in normal breast epithelial cells. To determine if MRG can modulate in vivo growth of human breast cancers, we transfected a full-length MRG cDNA into MDA-MB-231 human breast cancer cells and studied the orthotopic growth of MRG transfectants versus control transfectants in the mammary fat pad of athymic nude mice. Overexpression of MRG in human breast cancer cells significantly suppressed cell proliferation in vitro and tumor growth in an orthotopic nude mouse model. These results suggest that MRG has tumor-suppressing activity, and the loss of MRG expression may be involved in the development and progression of breast cancer.

Cystatin E is a novel human cysteine proteinase inhibitor with structural resemblance to family 2 cystatins

A new member of the human cystatin superfamily, called cystatin E, has been found by expressed sequence tag (EST) sequencing in amniotic cell and fetal skin epithelial cell cDNA libraries. The sequence of a full-length amniotic cell cDNA clone contained an open reading frame encoding a putative 28-residue signal peptide and a mature protein of 121 amino acids, including four cysteine residues and motifs of importance for the inhibitory activity of Family 2 cystatins like cystatin C. Recombinant cystatin E was produced in a baculovirus expression system and isolated. An antiserum against the recombinant protein could be used for affinity purification of cystatin E from human urine, as confirmed by N-terminal sequencing. The mature recombinant protein processed by insect cells started at amino acid 4 (cystatin C numbering), and displayed reversible inhibition of papain and cathepsin B (Ki values of 0.39 and 32 nM, respectively), in competition with substrate. Cystatin E is thus a functional cysteine proteinase inhibitor despite relatively low amino acid sequence similarities with human cystatins (26-34% identity with sequences for the Family 2 cystatins C, D, S, SN, and SA; <30% with the Family 1 cystatins, A and B, and domains 2 and 3 of the Family 3 cystatin, kininogen). Unlike other human low Mr cystatins, cystatin E is a glycoprotein, carrying an N-linked carbohydrate chain at position 108. Northern blot analysis revealed that the cystatin E gene is expressed in most human tissues, with the highest mRNA amounts found in uterus and liver. A strikingly high incidence of cystatin E clones in cDNA libraries from fetal skin epithelium and amniotic membrane cells (>0.5% of clones sequenced) indicates a protective role of cystatin E during fetal development.

Optimization of relative weights and wedge angles in treatment planning

An efficient technique to optimize beam weights and wedge angles in radiotherapy treatment planning has been developed. Based on the fact that a wedged field can be regarded as a superposition of an open field and a nominal wedged field, this approach reduces the problem of finding J beam weights and the corresponding wedge angles to optimizing a linear system with 2J unknowns (weights of J open beams and J nominal wedged beams), where J is the total number of incident beam directions. Two iterative algorithms similar to the iterative-least-square technique in image reconstruction are used to optimize the system. Application of the algorithms to two specific examples shows that this technique can reduce treatment planning time and effort, and promises to create a better solution for an arbitrarily complex treatment plan.

Signal transduction by DR3, a death domain-containing receptor related to TNFR-1 and CD95

Tumor necrosis factor receptor-1 (TNFR-1) and CD95 (also called Fas or APO-1) are cytokine receptors that engage the apoptosis pathway through a region of intracellular homology, designated the "death domain." Another death domain-containing member of the TNFR family, death receptor 3 (DR3), was identified and was shown to induce both apoptosis and activation of nuclear factor kappaB. Expression of DR3 appears to be restricted to tissues enriched in lymphocytes. DR3 signal transduction is mediated by a complex of intracellular signaling molecules including TRADD, TRAF2, FADD, and FLICE. Thus, DR3 likely plays a role in regulating lymphocyte homeostasis.

Iterative methods for inverse treatment planning

Iterative algorithms used in imaging science are generalized to study inverse treatment planning in radiotherapy. These algorithms consist of iteratively changing trial incident fluence functions which eventually yield a dose distribution consistent with the prescribed distribution. Application of the algorithms is presented for test cases of a circular phantom with cylindrically symmetric dose distributions. A comparison of the iterative beam profiles with previous analytic solutions shows excellent agreement, indicating that iterative techniques are promising to create sophisticated treatment plans. The relationship between the algorithms and several existing inverse treatment planning methods is discussed.

Antiinflammatory effect of Trichosanthes kirilowii Maxim, and its effective parts

This study was carried out to elucidate the antiinflammatory effect of 50% ethanol extract obtained from the fruit of Trichosanthes kirilowii Maxm, and its effective parts. The cut dried fruit was separated into the whole fruit, seeds and remaining parts, and each part was extracted with 50% ethanol. The antiinflammatory activity of these extracts was investigated on acetic acid-induced vascular permeability in mice, carrageenin-induced edema and cotton pellet-induced granuloma formation in rats, as well as writhing symptoms in mice. The whole fruit and seed extractions showed an antiinflammatory activity and analgesic activity, but the other part did not when given perorally. These results suggest that the antiinflammatory effect and analgesic effect induced by ethanol extract of the fruit of T. kirilowii may be due to the seeds contained in the fruit.

Accelerative effect of "nanshikon" and its constituents on the proliferation of granulation tissue in rats

The present study was carried out to examine the accelerative effect of the ether extract obtained from "Nanshikon" on the proliferation of granulation tissue induced by cotton pellet in rats and to elucidate its active principles. Among naphthoquinone derivatives, the ether extract contained mostly teracrylshikonin. At corresponding doses based on the contents of the naphthoquinone derivatives in the ether extract, the accelerative potencies of teracrylshikonin, beta, beta-dimethylacrylshikonin, and a mixture of alpha-methyl-n-butylshikonin and isovalerylshikonin were about the same. Also, the accelerative potencies of these compounds were somewhat weaker than that of the ether extract. From these results, it is suggested that the accelerative effect of the ether extract on the proliferation of granulation tissue is mainly due to teracrylshikonin, beta, beta-dimethylacrylshikonin and a mixture of alpha-methyl-n-butylshikonin and isovalerylshikonin contained in the ether extract, and the accelerative effect induced by ether extract might be an additive effect of these naphthoquinone derivatives.

cAMP response element-binding protein (CREB) interacts with transcription factors IIB and IID

cAMP response element-binding protein (CREB) participates in both constitutive and cAMP-induced transcription of cAMP-responsive genes. CREB-mediated constitutive transcription requires only CREB-binding sites and a minimal promoter region (containing the TATA through start sequences), indicating that CREB interacts directly with components of the general transcription machinery. In this study, a coimmunoprecipitation assay was used to test for interaction of CREB with the general transcription factors (TF) TFIIB and TFIID and the core component of TFIID, TATA-binding protein (TBP). Human TFIIB and TBP, tagged with distinct epitopes (eTFIIB and eTBP), were expressed in and purified from Escherichia coli, and holo-eTFIID, containing eTBP, was obtained from the HeLa cell line LTR alpha 3. 35S-Labeled CREB, synthesized in vitro and incubated with eTFIIB, was coimmunoprecipitated with antibody recognizing eTFIIB, indicating that CREB specifically binds to TFIIB. 35S-CREB was coimmunoprecipitated with antibody against eTBP, but only when incubated with the holo-eTFIID complex, not with eTBP alone. TFIIB interacted with TBP, but CREB was not coprecipitated with the eTBP antibody when incubated with eTBP plus TFIIB, so CREB did not form a stable ternary complex with TFIIB and TBP. Conversely, depletion of TFIIB from the holo-TFIID preparation did not diminish the level of interaction between CREB and TFIID. Thus, CREB interacts independently with TFIIB and TFIID, but not directly with TBP. A protein kinase A phosphorylation site mutant of CREB and wild-type CREB exhibited equivalent interaction with TFIIB, indicating that this phosphorylation is not required. Consistent with the role of CREB in promoting constitutive or basal transcription, the constitutive activation domain of CREB was sufficient for interaction with both TFIIB and TFIID.

Three distinct regions within the constitutive activation domain of cAMP regulatory element-binding protein (CREB) are required for transcription activation

The transcription factor cAMP regulatory element-binding protein (CREB) mediates both constitutive and cAMP-induced gene expression through distinct, independently acting domains. The constitutive activation domain (CAD) (amino acids (aa) 165-252) encompasses and overlaps exon 9 of the CREB gene (E9, aa 180-243). In the present study, deletion of either the CAD or exon 9 from CREB-GAL4 (CRG) reduced constitutive activity to less than 2-fold, without affecting kinase inducible activity. However, fusion of the CAD to the GAL4 DNA binding domain (CAD-G4) stimulated transcription, whereas fusion of exon 9 sequences did not. Deletion of the amino-terminal flanking region of exon 9 (aa 165-180), but not COOH-terminal flanking sequences (aa 243-252), decreased constitutive activation in either the CAD-G4 or CRG background. Deletion of the previously characterized glutamine-rich region (Q3, aa 218-252) or of a region containing a hydrophobic cluster of amino acids (HC, aa 180-218) also reduced constitutive activation by either CAD-G4 or CRG. No single mutation of hydrophobic residues within HC impaired activity of the CAD, but double and triple mutations did, suggesting that multiple weak interactions are involved in function of the HC region. Thus, exon 9 of the CREB gene is necessary but not sufficient for constitutive activation. The CAD requires three distinct regions for function, suggesting that CREB may interact with multiple targets in the RNA polymerase II complex.

The endoplasmic reticular heat shock protein gp96 is transcriptionally upregulated in interferon-treated cells

A cDNA clone complementary to an interferon (IFN)-induced mRNA approximately 3 kb in length was identified and sequenced revealing homology with the endoplasmic reticular heat shock protein/ATPase gp96. Both IFN-alpha and -gamma transcriptionally upregulate expression of this gene. gp96 transcripts, protein, and ATPase activity are shown to be enhanced as a result of IFN treatment in two human cell lines and this effect requires de novo protein synthesis. gp96 molecules have recently been implicated in the presentation of endogenous antigens. A number of the key elements in this pathway, the transporter proteins, the major histocompatibility complex (MHC)-linked units of the proteasomes and the MHC class I molecules are known to be IFN inducible. Our results show that yet another molecule suggested to play an accessory role in the endogenous presentation pathway is IFN inducible. Further, our studies represent the first demonstration of modulation of expression of a heat shock protein by a cytokine and identify a new enzymatic activity upregulated in IFN-treated cells.

[Immunological observation on chyluric patients with heat-clearing and hemostatic drugs]

In order to investigate the pathogenesis and therapeutic mechanism of chyluria, an experiment with a basic Heat-clearing and hemostatic prescription was conducted in treating 30 patients of chyluria. The result, 26 cases were cured completely. The cell-mediated and humoral immunity observation showed that OKT3 and OKT4 levels were commonly low in chyluric cases, and OKT8 as higher than normal value, the OKT4/OKT8 ratio was inverted before treatment. While OKT3 and OKT4 increased commonly, and OKT8 decreased with the OKT4/OKT8 ratio adjusted after treatment. Meanwhile, humoral immunity level was also commonly low before treatment, it increased after treatment.

Suppression of mitochondrial mRNA levels and mitochondrial function in cells responding to the anticellular action of interferon

A lambda cDNA library prepared from polyadenylated RNA isolated from Daudi cells was differentially screened to isolate cDNAs that recognize mRNA whose levels are reduced following interferon (IFN) treatment. Southern blot and DNA sequence analysis of 20 cDNA clones that were isolated revealed that they represented mitochondrially encoded mRNAs for the following proteins: cytochrome c oxidase subunits II and III, ATPase 6, cytochrome b, and subunit 1 of the NADH dehydrogenase. Northern blot analysis employing these cDNAs and oligonucleotides generated to the remaining mitochondrially encoded mRNAs demonstrated that IFN-alpha treatment of Daudi cells mediates a time-dependent suppression of the level of all of the mitochondrially encoded mRNAs. Study of this IFN-mediated effect reveals that: (i) the suppression of the level of these mRNAs is dependent on protein synthesis, (ii) it can be observed to occur prior to any detectable effect on thymidine incorporation, (iii) the degree of suppression correlates with the sensitivity of the cells to the anticellular action of IFN, and (iv) the suppression of the level of these RNAs appears to result from an effect on the level of transcription rather than on the stability of these mRNAs. A study of the level of cellular respiration in IFN-treated Daudi cells reveals a clear suppression 3 h following IFN treatment.

Involvement of 3',5'-cyclic adenosine monophosphate regulatory element binding protein (CREB) in both basal and hormone-mediated expression of the phosphoenolpyruvate carboxykinase (PEPCK) gene

Transcription of the phosphoenolpyruvate carboxykinase (PEPCK) and PEPCK-chloramphenicol acetyltransferase (CAT) genes is induced by cAMP and glucocorticoids and is inhibited by insulin in H4IIE cells, as it is in liver. In contrast, PEPCK-CAT expression in HepG2 cells is not affected by insulin but is induced by cAMP, which in turn is repressed by glucocorticoids. Mutations were introduced into well defined transcription factor binding sites to investigate possible interactions between the cAMP regulatory element (CRE) binding protein (CREB) and glucocorticoid response unit (GRU) binding proteins. H4IIE rat hepatoma cells were transfected with PEPCK-CAT plasmids with or without an expression vector for protein kinase A (PKA). Glucocorticoid-induced CAT activity was dependent upon the GRU and was decreased in plasmids lacking the CRE. To determine the direct effects of CREB, the DNA binding and dimerization domain of GAL4 was substituted for that of CREB (CRG), and the PEPCK CRE was replaced with a GAL4 binding site (G4PEPCK-CAT). CRG elevated basal and glucocorticoid-induced activities of G4PEPCK-CAT equally and restored responsiveness to PKA. The basal activity of CRG was not diminished by concomitant treatment with PKA plus its inhibitor peptide, PKI, or by mutation of the PKA phosphorylation. Deletion of C-terminal regions of the CREB activation domain from CRG diminished basal activation without affecting induction by PKA. The glucocorticoid-induced level of CAT activity decreased in proportion to the reduced ability of CREB to activate basal transcription. Induction by glucocorticoid, in the absence or presence of PKA, was not affected by CRG, indicating that interaction of GRU-bound factors with CREB is not required for glucocorticoid induction of PEPCK. These results indicate that CREB is directly involved in basal and PKA-induced expression of PEPCK, and that CREB supports glucocorticoid-induced PEPCK expression through its positive effect on basal transcription.

[Electron microscopy observation on pre- and post-treatment skin of dorsum pedis of chyluric patient treated with heat-clearing and hemostatic drugs--the lymphangial wall damage being the pathogenesis of chyluria]

Heat-clearing and hemostatic drugs were effective in treating chyluria. In order to explore the curative mechanism, a group of 10 in-patients with chyluria were chosen and treated with heat-clearing and hemostatic drugs for 45 days. Some pre- and post-treatment skin from dorsum pedis of the patients were taken off and observed under electron microscope. It showed that the walls of lymphatic capillaries were seriously damaged before treatment and rehabilitated wall after treatment. The pinocytotic vesicles were packed tightly in the endothelial cells of capillaries before treatment and their number was decreased remarkably after treatment; the mast cells were rare in number and abnormal as spindle shape before treatment and they increased in number and became round or oval in shape, the nucleus became large, the granules they contained became more in number and larger in size after treatment, lymph edema was noticed before treatment and it disappeared after treatment. The result showed that the extensive lesion of lymphangial walls is the pathogenesis of chyluria, while the rehabilitation of them is the curative mechanism. It seems that in the process of rehabilitation the mast cells act took the role of "soldier-engineer".

Dietary trace elements and esophageal cancer mortality in Shanxi, China

To explore the relation between esophageal cancer and dietary trace elements in humans, we estimated the average daily intake of zinc, copper, iron, selenium, molybdenum, silicon, cadmium, and nickel in 21 Chinese communes, where the annual mortality rate from esophageal cancer among the population 30 years of age and over ranged from 0 to 495/100,000 person-years. We also estimated the relative level of calcium consumption. Zinc and copper intake were inversely related to esophageal cancer mortality, and calcium intake levels was positively related to esophageal cancer mortality. The predicted esophageal cancer mortality among a vegetarian population with a high level of dietary calcium and a low level of dietary zinc was 5.3 times as high as that in a vegetarian population with a low level of dietary calcium and a high level of dietary zinc. The influence of a high level of dietary calcium in a vegetarian population may be explained by a reduction in the absorption of dietary zinc.

Interferon induces tryptophanyl-tRNA synthetase expression in human fibroblasts

A cDNA clone complementary to an interferon (IFN)-induced mRNA was isolated and used to characterize the regulation of expression of its RNA by the IFNs and to identify the protein its RNA encodes. This cDNA hybridizes to IFN-induced 3.1- and 2.3-kilobase mRNAs that are synthesized in response to both IFN-alpha and IFN-gamma. IFN-gamma induces the sustained accumulation of these mRNAs while IFN-alpha induces their transient accumulation. Cycloheximide (50 micrograms/ml) failed to inhibit the induction of these mRNAs by either IFN-alpha or IFN-gamma, suggesting that their induction does not require de novo protein synthesis. DNA sequence analysis of this cDNA reveals that it encodes a protein of Mr 53,168 that has sequence homology with and the biological activity of a tryptophanyl-tRNA synthetase, an enzymatic activity that has been demonstrated to play a role in and be modulated by the growth of cells. Elevated levels of this enzyme may be involved in the cell growth inhibitory activity of the IFNs.

[Preliminary study of therapeutical mechanism on chyluria by heat-cleaning and hemostasis drugs]

Ten cases of filarial chyluria were treated with Chinese medical herbs. The results showed that the average concentration of serum histamine of 142 ng/ml before treatment dropped to 93 ng/ml after treatment. The average lymph-vessel pressure of 9.93 cmH2O in dorsalis pedis dropped to 4.74 cmH2O after cure. The prevalent microcirculation obstacle of medium to serious grade also was improved or recovered. The average serum viscosity of 1,884 before treatment dropped to 1,725. These results indicated that the chronic lymphatic inflammation occurring in pelvis or behind peritoneum due to perennial stimulation of adult filariae, caused the high concentration of inflammatory medium tissues, the expansion of micro-vessels and the increase of lymph-vessel pressure. Therefore, the microcirculation obstacle was the principle pathogeny of filarial chyluria.