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Liu Q, Xu W, Cheng X, Jin G, Shen X, Lou H, Liu J. Molecular cloning and sequence analysis of cDNA encoding haemorrhagic toxin acutolysin A from Agkistrodon acutus. Toxicon 1999; 37:1539-48. [PMID: 10482389 DOI: 10.1016/s0041-0101(99)00102-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
By means of reverse transcription polymerase chain reaction, a full-length cDNA of 1632 bp is amplified from the snake venom gland total RNA of Agkistrodon acutus. Analysis of the nucleotide sequence indicates that the amplified cDNA contains a complete open reading frame encoding 413 amino acid residues including signal peptide sequence, zymogen sequence and proteinase domain. The zymogen sequence contains PKMCGVT motif which is highly conserved in almost all venom metalloproteinases. The metalloproteinase domain contains the conserved signature zinc-binding motif HEXXHXXGXXH in the catalytic region. The predicted amino acid sequence of the metalloproteinase domain is identical to the crystallographic sequence of acutolysin A and also shares high homology with other class I snake venom haemorrhagic toxins.
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Saito S, Aras RS, Lou H, Ramwell PW, Foegh ML. Effects of estrogen on nitric oxide synthase expression in rat aorta allograft and smooth muscle cells. J Heart Lung Transplant 1999; 18:937-45. [PMID: 10561103 DOI: 10.1016/s1053-2498(99)00060-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND We find that chronic estradiol treatment inhibits the development of transplant arteriosclerosis (TA). The mechanism of this inhibition remains unclear. The objective of this study is to investigate in a non-cyclosporin-requiring TA model whether estradiol-17beta treatment modulates the expression of both endothelial nitric oxide synthase (ecNOS) and inducible nitric oxide synthase (iNOS) in the early phase following transplantation. METHODS Orthotopic abdominal aorta allograft transplantation was performed in male rats using Brown-Norway rats as donors and Lewis rats as recipients. The recipients (n = 50) were treated with estradiol 20 microg/kg/day or placebo by osmotic minipump from 2 days prior to surgery until sacrifice on post-operative days 1, 3, 7, 14, and 21. The allografts were harvested and cross-sections of the vascular tissues were used for immunohistochemical staining of ecNOS and iNOS. The effects of estradiol on cytokine-induced (tumor necrosis factor-alpha and interleukin-1 beta iNOS protein and messenger RNA (mRNA) expression were also evaluated on rat aorta smooth muscle cells by Western blotting and RT-PCR in vitro, respectively. RESULTS The expression of ecNOS and iNOS was graded semiquantitatively from 0 to +3. Estrogen elevates ecNOS expression in the intima in the early phase following transplantation, 0.85 +/- 0.14 (day 7) and 1.08 +/- 0.11 (day 14) vs 1.53 +/- 0.25 (day 7) and 1.60 +/- 0.17 (day 14) for placebo and estradiol treated groups respectively, p < 0.01. Estrogen suppresses iNOS expression in neointima (0.67 +/- 0.17 vs 0.24 +/- 0.04, p < 0.01, day 14), media (1.03 +/- 0.15 vs 0.4 +/- 0.09, p < 0.01, day 7), and adventitia (1.55 +/- 0.12 vs 1.02 +/- 0.10, p < 0.05, day 14) in the same phase. Estradiol treatment inhibits cytokine-induced iNOS mRNA expression in cultured smooth muscle cells. CONCLUSIONS Chronic estrogen treatment modulates both ecNOS and iNOS expression in the early phase following transplantation. This is associated with the estrogen-protective effects on TA.
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MESH Headings
- Animals
- Aorta, Abdominal/cytology
- Aorta, Abdominal/drug effects
- Aorta, Abdominal/enzymology
- Aorta, Abdominal/transplantation
- Arteriosclerosis/chemically induced
- Arteriosclerosis/enzymology
- Cells, Cultured
- Disease Models, Animal
- Estradiol/pharmacology
- Immunohistochemistry
- Male
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/enzymology
- Nitric Oxide Synthase/drug effects
- Nitric Oxide Synthase Type II
- Nitric Oxide Synthase Type III
- Random Allocation
- Rats
- Rats, Inbred Lew
- Time Factors
- Transplantation, Homologous
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Krummenacher C, Rux AH, Whitbeck JC, Ponce-de-Leon M, Lou H, Baribaud I, Hou W, Zou C, Geraghty RJ, Spear PG, Eisenberg RJ, Cohen GH. The first immunoglobulin-like domain of HveC is sufficient to bind herpes simplex virus gD with full affinity, while the third domain is involved in oligomerization of HveC. J Virol 1999; 73:8127-37. [PMID: 10482562 PMCID: PMC112829 DOI: 10.1128/jvi.73.10.8127-8137.1999] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The human herpesvirus entry mediator C (HveC/PRR1) is a member of the immunoglobulin family used as a cellular receptor by the alphaherpesviruses herpes simplex virus (HSV), pseudorabies virus, and bovine herpesvirus type 1. We previously demonstrated direct binding of the purified HveC ectodomain to purified HSV type 1 (HSV-1) and HSV-2 glycoprotein D (gD). Here, using a baculovirus expression system, we constructed and purified truncated forms of the receptor containing one [HveC(143t)], two [HveC(245t)], or all three immunoglobulin-like domains [HveC(346t)] of the extracellular region. All three constructs were equally able to compete with HveC(346t) for gD binding. The variable domain bound to virions and blocked HSV infection as well as HveC(346t). Thus, all of the binding to the receptor occurs within the first immunoglobulin-like domain, or V-domain, of HveC. These data confirm and extend those of Cocchi et al. (F. Cocchi, M. Lopez, L. Menotti, M. Aoubala, P. Dubreuil, and G. Campadelli-Fiume, Proc. Natl. Acad. Sci. USA 95:15700, 1998). Using biosensor analysis, we measured the affinity of binding of gD from HSV strains KOS and rid1 to two forms of HveC. Soluble gDs from the KOS strain of HSV-1 had the same affinity for HveC(346t) and HveC(143t). The mutant gD(rid1t) had an increased affinity for HveC(346t) and HveC(143t) due to a faster rate of complex formation. Interestingly, we found that HveC(346t) was a tetramer in solution, whereas HveC(143t) and HveC(245t) formed dimers, suggesting a role for the third immunoglobulin-like domain of HveC in oligomerization. In addition, the stoichiometry between gD and HveC appeared to be influenced by the level of HveC oligomerization.
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Fujiyoshi T, Li HC, Lou H, Yashiki S, Karino S, Zaninovic V, Oneegllo SG, Camacho M, Andrade R, Hurtado LV, Gomez LH, Damiani E, Cartier L, Dipierri JE, Hayami M, Sonoda S, Tajima K. Characteristic distribution of HTLV type I and HTLV type II carriers among native ethnic groups in South America. AIDS Res Hum Retroviruses 1999; 15:1235-9. [PMID: 10505671 DOI: 10.1089/088922299310124] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
To confirm the geographic and ethnic segregation of HTLV-I and HTLV-II carriers in native populations in South America, we have conducted a seroepidemiological study of native populations in South America, including HTLV-I carriers distributed among seven ethnic groups in the Andes highlands of Colombia, Peru, Bolivia, Argentina, and Chile, and two ethnic groups on Chiloe Island and Easter Island; and HTLV-II carriers distributed among seven ethnic groups of the lowlands along the Atlantic coast of Colombia, Orinoco, Amazon, and Patagonia, and one ethnic group on Chiloe Island. The incidence rate of HTLV-I and HTLV-II carriers varied among the ethnic groups, ranging from 0.8 to 6.8% for HTLV-I seropositivity and from 1.4 to 57.9% for HTLV-II seropositivity. A new HTLV-I focus was found among the Peruvian Aymara (1.6%), the Bolivian Aymara (5.3%) and Quechua (4.5%), the Argentine Puna (2.3%), and the Chilean Atacama (4.1%), while on HTLV-II focus was found among the Brazilian Kayapo (57.9%), the Paraguayan Chaco (16.4%), and the Chilean Alacalf (34.8%) and Yahgan (9.1%). The distribution of HTLV-I/II foci showed a geographic clustering of HTLV-I foci in the Andes highlands and of HTLV-II foci in the lowlands of South America. It was thus suggested that South American natives might be divided into two major ethnic groups by HTLV-I and HTLV-II carrier state.
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Lou H, Huang L, Mai VQ. Effect of DNA binding protein Ssh12 from hyperthermophilic archaeonSulfolobus shibatae on DNA supercoiling. SCIENCE IN CHINA. SERIES C, LIFE SCIENCES 1999; 42:401-408. [PMID: 18763131 DOI: 10.1007/bf02882060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/1999] [Indexed: 05/26/2023]
Abstract
An 11.5-ku DNA binding protein, designated as Ssh12, was purified from the hyperthermophilic archaeonSulfolobus shibatae by column chromatography in SP Sepharose, DNA cellulose and phosphocellulose. Ssh12 accounts for about 4 % of the total cellular protein. The protein is capable of binding to both negatively supercoiled and relaxed DNAs. Nick closure analysis revealed that Ssh12 constrains negative supercoils upon binding to DNA. While the ability of the protein to constrain supercoils is weak at 22 degrees C, it is enhanced substantially at temperatures higher than 37 degrees C. Both the cellular content and supercoil-constraining ability of Ssh12 suggest that the protein may play an important role in the organization and stabilization of the chromosome ofS. shibatae.
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Tian J, Chen Y, Ren J, Lou H, Gao Y. [Infrared spectral identification of rhizoma Corydalis and rhizoma Corydalis repentis]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1999; 24:327-8, 381. [PMID: 12212022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
OBJECTIVE To study the IR spectra of Rhizoma Corydalis and Rhizoma Corydalis Repentis. METHOD The petroleum ether, ethyl ether and water extracts obtained by the same isolating procedure from Rhizoma Corydalis and Rhizoma Corydalis Repentis were determined by IR spectrophotometry. RESULTS The IR spectral evidences of the two samples showed distinct characteristics and good repeatability. CONCLUSION The IR spectral evidences can be used to differentiate Rhizoma Corydalis and Rhizoma Corydalis Repentis.
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Abstract
1. The aetiology of chronic rejection is clearly multifactorial and relates to both immunological and non-immunological factors. 2. Our studies suggest that the insulin-like growth factor (IGF)-I ligand and receptor genes are rate limiting in smooth muscle proliferation in the development of transplant arteriosclerosis. 3. Suppressing growth factor ligand or receptor expression could be effective strategies for the prevention or treatment of transplant arteriosclerosis. 4. We consistently find chronic oestradiol treatment of transplant recipients inhibits arteriosclerosis by attenuating both IGF-I expression and the immune response, particularly major histocompatibility complex class II expression. 5. Thus, a cell- or tissue-specific oestrogen with minimal feminizing properties may be an ideal drug for prevention of one of the major causes of loss of transplant function.
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Lou H, Helfman DM, Gagel RF, Berget SM. Polypyrimidine tract-binding protein positively regulates inclusion of an alternative 3'-terminal exon. Mol Cell Biol 1999; 19:78-85. [PMID: 9858533 PMCID: PMC83867 DOI: 10.1128/mcb.19.1.78] [Citation(s) in RCA: 130] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/1998] [Accepted: 10/14/1998] [Indexed: 11/20/2022] Open
Abstract
Polypyrimidine tract-binding protein (PTB) is an abundant vertebrate hnRNP protein. PTB binding sites have been found within introns both upstream and downstream of alternative exons in a number of genes that are negatively controlled by the binding of PTB. We have previously reported that PTB binds to a pyrimidine tract within an RNA processing enhancer located adjacent to an alternative 3'-terminal exon within the gene coding for calcitonin and calcitonin gene-related peptide. The enhancer consists of a pyrimidine tract and CAG directly abutting on a 5' splice site sequence to form a pseudoexon. Here we show that the binding of PTB to the enhancer pyrimidine tract is functional in that exon inclusion increases when in vivo levels of PTB increase. This is the first example of positive regulation of exon inclusion by PTB. The binding of PTB was antagonistic to the binding of U2AF to the enhancer-located pyrimidine tract. Altering the enhancer pyrimidine tract to a consensus sequence for the binding of U2AF eliminated enhancement of exon inclusion in vivo and exon polyadenylation in vitro. An additional PTB binding site was identified close to the AAUAAA hexanucleotide sequence of the exon 4 poly(A) site. These observations suggest a dual role for PTB in facilitating recognition of exon 4: binding to the enhancer pyrimidine tract to interrupt productive recognition of the enhancer pseudoexon by splicing factors and interacting with the poly(A) site to positively affect polyadenylation.
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Saito S, Foegh ML, Motomura N, Lou H, Kent K, Ramwell PW. Estradiol inhibits allograft-inducible major histocompatibility complex class II antigen expression and transplant arteriosclerosis in the absence of immunosuppression. Transplantation 1998; 66:1424-31. [PMID: 9869082 DOI: 10.1097/00007890-199812150-00004] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The etiology of transplant arteriosclerosis is unknown, but current data point to the alloimmune response. Previously, we found that estradiol-17beta (E2) with immunosuppressant cyclosporine abolishes major histocompatibility complex (MHC) class II expression in the allograft. This study determines the effect of E2 on MHC class II antigen expression in the allograft, in the absence of immunosuppression. METHODS Lewis male rats received orthotopic abdominal aorta allografts from male Brown-Norway rats. The recipients were treated continuously subcutaneously with either 20 microg x kg(-1) x day1 of E2 (n=20) or placebo (n=20), from 2 days before transplantation until death on posttransplant days 1, 3, 7, and 14. The allografts were harvested and processed for morphometry and for immunohistochemical staining of MHC class II antigens, macrophages, CD4 and CD8 T lymphocytes, interferon-gamma (IFN-gamma), and IFN-gamma receptor. RESULTS With E2 treatment, we observed that inducible MHC class II antigen expression is abolished in the media of the vascular allograft; the expression of IFN-gamma and IFN-gamma receptor is unaffected; and macrophage infiltration of the vascular allograft is inhibited significantly (P<0.01), whereas the CD4 and CD8 T lymphocytes are not significantly (P=0.07) suppressed. The myointimal hyperplasia in the allografts from E2-treated-recipients was 3-4-fold less than that from the placebo-treated recipients. CONCLUSIONS Without immunosuppression, E2 inhibition of transplant arteriosclerosis is still associated with inhibition of inducible MHC class II antigen expression in the allografts. The estradiol-17beta abolition of inducible MHC class II antigen expression in the aorta allograft occurs in spite of up-regulation of IFN-gamma ligand and receptor protein.
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Lou H, Martin MB, Stoica A, Ramwell PW, Foegh ML. Upregulation of estrogen receptor-alpha expression in rabbit cardiac allograft. Circ Res 1998; 83:947-51. [PMID: 9797344 DOI: 10.1161/01.res.83.9.947] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Estrogen receptor (ER) expression has been detected in different tissues, and estradiol-17beta treatment protects against experimental transplant arteriosclerosis. In this study, ER-alpha expression in the rabbit hearts and attached aortas before and after cardiac-aorta allograft transplantation was examined. Ten male New Zealand White rabbits were transplanted with cardiac-aorta allografts from male Dutch Belted rabbits. This transplant arteriosclerosis model uses a 0.5% cholesterol diet and immunosuppression with cyclosporin A (10 mg . kg-1 . d-1) until euthanatization 42 days later. The cardiac grafts with the attached aorta were harvested. Strong staining of ER-alpha protein was shown in the coronary arteries of the cardiac allografts by immunohistochemistry with the use of a mouse anti-human ER-alpha monoclonal antibody (ID5). In contrast, both the nongrafted hearts of the recipients and donor hearts expressed only weak staining. RNase protection assay with the use of a 32P-labeled ER-alpha antisense riboprobe (pOR 300) proved that the basal expression of ER-alpha mRNA is similar in the nongrafted aorta of both recipients and donors. A marked increase of ER-alpha mRNA was observed in the allograft aorta compared with the nongrafted aorta (289+/-69%, P<0. 02) by reverse transcription and polymerase chain reaction. The DNA sequence analysis confirmed that the polymerase chain reaction-amplified fragment corresponded to ER-alpha. This is the first observation of ER-alpha upregulation in the allograft vasculature and may relate to the allograft cardiovascular protective effects of estrogen.
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Lou H, Li HC, Kuwayama M, Yashiki S, Fujiyoshi T, Suehara M, Osame M, Yamashita M, Hayami M, Gurtsevich V, Ballas M, Imanishi T, Sonoda S. HLA class I and class II of the Nivkhi, an indigenous population carrying HTLV-I in Sakhalin, Far Eastern Russia. TISSUE ANTIGENS 1998; 52:444-51. [PMID: 9864034 DOI: 10.1111/j.1399-0039.1998.tb03071.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The Nivkhi are a native people isolated in the Nogliki region of Sakhalin, Far East Russia, where our group recently recognized human T-cell lymphoma virus type I (HTLV-I) infection. In order to trace the Nivkhi's ethnic background and the HTLV-I carriers, we investigated HLA class I and II allele types of 53 Nivkhi (including four HTLV-I carriers). Major HLA class I alleles of the Nivkhi were A*24, A*02, B*40, B*48, B*27, B*35 with allele frequencies similar to the Orochon, a native people isolated in Northeast China. Major Nivkhi class II alleles were DRB1*0901, DRB1*1401, DRB1*1201, DRB1*1106 with allele frequencies similar to the Ainu in Hokkaido, Japan, but dissimilar to other Asian Mongoloids, including the general Japanese population. The same HLA class I and II allele frequencies are found in both Nivkhi HTLV-I carriers and the background population. A dendrogram of HLA class I alleles showed that the Nivkhi were closely related to the Orochon and Yakut, and remotely related to the Japanese, Ainu and other Asian Mongoloids. Interestingly, the Nivkhi were intermediately related to the Amerindians (Inuit, Tlingit and Andeans), a relationship closer than to the Japanese and Asian Mongoloids. These results suggested the Nivkhi might be related to some genetic group of Northeast Asian Mongoloids like the Orochon and Yakut, being infected with HTLV-I in the distant past before diverging into the current major Mongoloid ethnic groups.
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Rux AH, Willis SH, Nicola AV, Hou W, Peng C, Lou H, Cohen GH, Eisenberg RJ. Functional region IV of glycoprotein D from herpes simplex virus modulates glycoprotein binding to the herpesvirus entry mediator. J Virol 1998; 72:7091-8. [PMID: 9696802 PMCID: PMC109930 DOI: 10.1128/jvi.72.9.7091-7098.1998] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/1998] [Accepted: 06/03/1998] [Indexed: 11/20/2022] Open
Abstract
Glycoprotein D (gD) of herpes simplex virus (HSV) is essential for virus entry and has four functional regions (I to IV) important for this process. We previously showed that a truncated form of a functional region IV variant, gD1(Delta290-299t), had an enhanced ability to block virus entry and to bind to the herpesvirus entry mediator (HveAt; formerly HVEMt), a cellular receptor for HSV. To explore this phenotype further, we examined other forms of gD, especially ones with mutations in region IV. Variant proteins with deletions of amino acids between 277 and 300 (region IV), as well as truncated forms lacking C-terminal residues up to amino acid 275 of gD, were able to block HSV entry into Vero cells 1 to 2 logs better than wild-type gD1(306t). In contrast, gD truncated at residue 234 did not block virus entry into Vero cells. Using optical biosensor technology, we recently showed that gD1(Delta290-299t) had a 100-fold-higher affinity for HveAt than gD1(306t) (3.3 x 10(-8) M versus 3.2 x 10(-6) M). Here we found that the affinities of other region IV variants for HveAt were similar to that of gD1(Delta290-299t). Thus, the affinity data follow the same hierarchy as the blocking data. In each case, the higher affinity was due primarily to a faster kon rather than to a slower koff. Therefore, once the gDt-HveAt complex formed, its stability was unaffected by mutations in or near region IV. gD truncated at residue 234 bound to HveAt with a lower affinity (2.0 x 10(-5) M) than did gD1(306t) due to a more rapid koff. These data suggest that residues between 234 and 275 are important for maintaining stability of the gDt-HveAt complex and that functional region IV is important for modulating the binding of gD to HveA. The binding properties of any gD1(234t)-receptor complex could account for the inability of this form of gDt to block HSV infection.
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Lou H, Neugebauer KM, Gagel RF, Berget SM. Regulation of alternative polyadenylation by U1 snRNPs and SRp20. Mol Cell Biol 1998; 18:4977-85. [PMID: 9710581 PMCID: PMC109082 DOI: 10.1128/mcb.18.9.4977] [Citation(s) in RCA: 155] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/1998] [Accepted: 06/02/1998] [Indexed: 11/20/2022] Open
Abstract
Although considerable information is currently available about the factors involved in constitutive vertebrate polyadenylation, the factors and mechanisms involved in facilitating communication between polyadenylation and splicing are largely unknown. Even less is known about the regulation of polyadenylation in genes in which 3'-terminal exons are alternatively recognized. Here we demonstrate that an SR protein, SRp20, affects recognition of an alternative 3'-terminal exon via an effect on the efficiency of binding of a polyadenylation factor to an alternative polyadenylation site. The gene under study codes for the peptides calcitonin and calcitonin gene-related peptide. Its pre-mRNA is alternatively processed by the tissue-specific inclusion or exclusion of an embedded 3'-terminal exon, exon 4, via factors binding to an intronic enhancer element that contains both 3' and 5' splice site consensus sequence elements. In cell types that preferentially exclude exon 4, addition of wild-type SRp20 enhances exon 4 inclusion via recognition of the intronic enhancer. In contrast, in cell types that preferentially include exon 4, addition of a mutant form of SRp20 containing the RNA-binding domain but missing the SR domain inhibits exon 4 inclusion. Inhibition is likely at the level of polyadenylation, because the mutant SRp20 inhibits binding of CstF to the exon 4 poly(A) site. This is the first demonstration that an SR protein can influence alternative polyadenylation and suggests that this family of proteins may play a role in recognition of 3'-terminal exons and perhaps in the communication between polyadenylation and splicing.
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Geng L, Zai N, Xiao Y, Song F, Tanaka A, Lou H, Sonoda S, Kanzaki T. Search for human T-lymphotropic virus type I carriers among northeastern Chinese. J Dermatol Sci 1998; 18:30-4. [PMID: 9747659 DOI: 10.1016/s0923-1811(98)00022-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Human T-lymphotropic virus type I (HTLV-I) is thought to be the causative agent of adult T-cell leukemia/ lymphoma (ATL). This virus infection is endemic in southwestern Japan, parts of Africa and the Caribbean Islands. We examined sera of 1645 subjects of Liaoning province, northeastern China to detect HTLV-I carriers in an effort to reveal the migratory route taken by the early Japanese (Jomon people). As a result, all sera were found to be negative as tested by particle-agglutination (PA), immunofluorescence (IF), enzyme-linked immunoabsorbent (ELISA) and Western blotting methods. This suggests that the Jomon people, who are thought to have brought HTLV-I to the Japan archipelago tens of thousands of years ago, did not come from northeast China.
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Krummenacher C, Nicola AV, Whitbeck JC, Lou H, Hou W, Lambris JD, Geraghty RJ, Spear PG, Cohen GH, Eisenberg RJ. Herpes simplex virus glycoprotein D can bind to poliovirus receptor-related protein 1 or herpesvirus entry mediator, two structurally unrelated mediators of virus entry. J Virol 1998; 72:7064-74. [PMID: 9696799 PMCID: PMC109927 DOI: 10.1128/jvi.72.9.7064-7074.1998] [Citation(s) in RCA: 188] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/1998] [Accepted: 05/20/1998] [Indexed: 11/20/2022] Open
Abstract
Several cell membrane proteins have been identified as herpes simplex virus (HSV) entry mediators (Hve). HveA (formerly HVEM) is a member of the tumor necrosis factor receptor family, whereas the poliovirus receptor-related proteins 1 and 2 (PRR1 and PRR2, renamed HveC and HveB) belong to the immunoglobulin superfamily. Here we show that a truncated form of HveC directly binds to HSV glycoprotein D (gD) in solution and at the surface of virions. This interaction is dependent on the native conformation of gD but independent of its N-linked glycosylation. Complex formation between soluble gD and HveC appears to involve one or two gD molecules for one HveC protein. Since HveA also mediates HSV entry by interacting with gD, we compared both structurally unrelated receptors for their binding to gD. Analyses of several gD variants indicated that structure and accessibility of the N-terminal domain of gD, essential for HveA binding, was not necessary for HveC interaction. Mutations in functional regions II, III, and IV of gD had similar effects on binding to either HveC or HveA. Competition assays with neutralizing anti-gD monoclonal antibodies (MAbs) showed that MAbs from group Ib prevented HveC and HveA binding to virions. However, group Ia MAbs blocked HveC but not HveA binding, and conversely, group VII MAbs blocked HveA but not HveC binding. Thus, we propose that HSV entry can be mediated by two structurally unrelated gD receptors through related but not identical binding with gD.
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Lou H, Ramwell PW, Foegh ML. Estradiol 17-beta represses insulin-like growth factor I receptor expression in smooth muscle cells from rabbit cardiac recipients. Transplantation 1998; 66:419-26. [PMID: 9734482 DOI: 10.1097/00007890-199808270-00002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND A crucial step in cell cycle progression is the activation of the insulin-like growth factor I (IGF-I) receptor (IGF-IR) by its ligand. Earlier, we found estradiol 17-beta treatment of cardiac allograft recipients attenuates transplant arteriosclerosis; this was associated with inhibition of vascular cell proliferation induced by IGF-I. The current study demonstrates regulation of IGF-IR by estradiol 17-beta in vivo and in vitro in recipient native and allograft aorta and in aorta smooth muscle cells (SMCs). METHODS Twenty cardiac transplant recipient rabbits were treated with estradiol 17-beta (100 microg/kg/day) or placebo for 6 weeks. IGF-IR expression in the coronary arteries of rabbits was demonstrated by immunohistochemistry. Reverse transcription-polymerase chain reaction and RNase protection assay were used to detect IGF-IR mRNA in rabbit aortas and cultured aortic SMCs in the presence or absence of estradiol 17-beta in vitro. IGF-I-induced cell proliferation was performed with the aorta explants and aorta SMCs from estradiol- or placebo-treated rabbits. RESULTS Estradiol 17-beta treatment of rabbits significantly inhibited IGF-IR expression in the allograft coronary arteries and abrogated cell proliferation induced by IGF-I in the allograft aorta compared with placebo-treated recipients (65.4+/-5% vs. 500+/-139%, P<0.002). Expression of IGF-IR mRNA in the allograft aorta of placebo-treated recipients was significant higher than that of the native aorta (286+/-56%, P<0.02). Estradiol treatment significantly inhibited IGF-IR mRNA expression in the aorta versus that of the placebo-treated recipients (65+/-8.5% vs. 140+/-23%, P<0.02). Repression of IGF-IR mRNA expression in aortic SMCs by estradiol in vitro was in a concentration-dependent manner (P<0.02). CONCLUSION Repression of IGF-IR protein and mRNA by estradiol 17-beta in vivo and in vitro suggest that one of the mechanisms of estradiol inhibition of SMC proliferation and transplant arteriosclerosis is down-regulation of IGF-IR.
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Willis SH, Rux AH, Peng C, Whitbeck JC, Nicola AV, Lou H, Hou W, Salvador L, Eisenberg RJ, Cohen GH. Examination of the kinetics of herpes simplex virus glycoprotein D binding to the herpesvirus entry mediator, using surface plasmon resonance. J Virol 1998; 72:5937-47. [PMID: 9621056 PMCID: PMC110398 DOI: 10.1128/jvi.72.7.5937-5947.1998] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Previously, we showed that truncated soluble forms of herpes simplex virus (HSV) glycoprotein D (gDt) bound directly to a truncated soluble form of the herpesvirus entry mediator (HveAt, formerly HVEMt), a cellular receptor for HSV. The purpose of the present study was to determine the affinity of gDt for HveAt by surface plasmon resonance and to compare and contrast the kinetics of an expanded panel of gDt variants in binding to HveAt in an effort to better understand the mechanism of receptor binding and virus entry. Both HveAt and gDt are dimers in solution and interact with a 2:1 stoichiometry. With HveAt, gD1(306t) (from the KOS strain of HSV-1) had a dissociation constant (KD) of 3.2 x 10(-6) M and gD2(306t) had a KD of 1.5 x 10(-6) M. The interaction between gDt and HveAt fits a 1:1 Langmuir binding model, i.e., two dimers of HveAt may act as one binding unit to interact with one dimer of gDt as the second binding unit. A gD variant lacking all signals for N-linked oligosaccharides had an affinity for HveAt similar to that of gD1(306t). A variant lacking the bond from cysteine 1 to cysteine 5 had an affinity for HveAt that did not differ from that of the wild type. However, variants with double cysteine mutations that eliminated either of the other two disulfide bonds showed decreased affinity for HveAt. This result suggests that two of the three disulfide bonds of gD are important for receptor binding. Four nonfunctional gDt variants, each representing one functional domain of gD, were also studied. Mutations in functional regions I and II drastically decreased the affinity of gDt for HveAt. Surprisingly, a variant with an insertion in functional region III had a wild-type level of affinity for HveAt, suggesting that this domain may function in virus entry at a step other than receptor binding. A variant with a deletion in functional region IV [gD1(Delta290-299t)] exhibited a 100-fold enhancement in affinity for HveAt (KD = 3.3 x 10(-8) M) due mainly to a 40-fold increase in its kinetic on rate. This agrees with the results of other studies showing the enhanced ability of gD1(Delta290-299t) to block infection. Interestingly, all the variants with decreased affinities for HveAt exhibited decreased kinetic on rates but only minor changes in their kinetic off rates. The results suggest that once the complex between gDt and HveAt forms, its stability is unaffected by a variety of changes in gD.
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Tian J, Ren J, Lou H, Gao Y, Yan Y, Chen Y. [Infrared spectra of Caulis Mahoniae and 6 species of medicinal plants of the same genus]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1998; 23:263-4, 318. [PMID: 11601309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Based on the IR spectra of the petroleum ether extract, ethyl ether extract and water extract of Caulis Mahoniae and six species of medicinal plants of the same genus, it has been found out that the differences of chemical constituents among the samples can be reflected by the changes of IR spectra. This method can be used as a rapid and exact means to search unknown species with same chemical constituents in the same genus and family.
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Motomura N, Lou H, Orskov H, Ramwell PW, Foegh ML. Exposure of vascular allografts to insulin-like growth factor-I (IGF-I) increases vascular expression of IGF-I ligand and receptor protein and accelerates arteriosclerosis in rats. Transplantation 1998; 65:1024-30. [PMID: 9583860 DOI: 10.1097/00007890-199804270-00003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Accelerated arteriosclerosis limits the survival of transplanted hearts. We hypothesized that insulin-like growth factor-I (IGF-I) is crucial in accelerating transplant arteriosclerosis. Recently, we reported that exposure to IGF-I prior to transplantation accelerates transplant arteriosclerosis in the rat aorta allograft model. Here, we studied the mechanism whereby IGF-I exposure accelerates transplant arteriosclerosis. METHODS The abdominal aorta was harvested from male Brown Norway rats and exposed to 0, 200, or 500 ng/ml of IGF-I at 37 degrees C for 30 min prior to transplantation to the abdominal position of male Lewis rats. The allografts were harvested 14 days later and processed for immunohistochemical staining for alpha-actin, growth factors (IGF-I, IGF-I receptor, platelet-derived growth factor-BB, and basic fibroblast growth factor), and immunological markers (major histocompatibility complex class II antigen, macrophage, and CD4- and CD8-positive T cells). RESULTS By 14 days, the ex vivo IGF-I donor aorta treatment with IGF-I increased in a concentration-dependent manner the expression of IGF-I and IGF-I receptor in both the intima and the adventitia. In contrast, the expression of platelet-derived growth factor-BB was decreased in a concentration-dependent manner in the intima while basic fibroblast growth factor remained unchanged. The cell-mediated immune response was not affected by IGF-I at 14 days after transplantation, which suggests that the immune events associated with acceleration of transplant arteriosclerosis may occur at an earlier time. CONCLUSION Acceleration of transplant arteriosclerosis by exposure to IGF-I is associated with increased IGF-I ligand and receptor expression in the allograft vascular wall. These data further suggest that IGF-I may be a major factor in mediating graft arteriosclerosis.
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Abstract
With the use of 99mTc-D, L,-hexamethylpropylenamine oxime and single photon emission computed tomography, regional cerebral blood flow was measured ictally in 12 mature infants with recurrent seizures and compared with a reference group of nine interictal studies. The study indicates that both clinical and electrical seizures in neonates are associated with a focal cerebral hyperperfusion of the same amount as seen in adults.
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Lou H, Gagel RF. Alternative RNA processing--its role in regulating expression of calcitonin/calcitonin gene-related peptide. J Endocrinol 1998; 156:401-5. [PMID: 9582495 DOI: 10.1677/joe.0.1560401] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The calcitonin/calcitonin gene-related peptide (CT/CGRP) gene is one of the earliest studied examples of alternative RNA processing. The regulatory mechanisms controlling this event are poorly understood. We have identified and characterized an intron element residing in intron 4 of the human CT/CGRP gene. This intron element functions to enhance polyadenylation of an embedded alternative 3'-terminal exon within the CT/CGRP gene and is potentially involved in tissue-specific regulation of CT/CGRP RNA processing.
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Saito S, Lou H, Ramwell P, Foegh M. Estradiol inhibits allograft arteriosclerosis by estrogen receptor α and β activation. J Am Coll Cardiol 1998. [DOI: 10.1016/s0735-1097(98)80900-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Saito S, Motomura N, Lou H, Ramwell PW, Foegh ML. Specific effects of estrogen on growth factor and major histocompatibility complex class II antigen expression in rat aortic allograft. J Thorac Cardiovasc Surg 1997; 114:803-9; discussion 809-10. [PMID: 9375610 DOI: 10.1016/s0022-5223(97)70084-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE Transplant arteriosclerosis is the major determinant for long-term survival of cardiac transplants. Estradiol treatment inhibits transplant arteriosclerosis. The objective of this study is to determine, in the absence of immunosuppression, the temporal effect of estradiol treatment on the expression of insulin-like growth factor, platelet-derived growth factor, basic fibroblast growth factor, and major histocompatibility complex class II antigen in rat aortic allografts. METHODS Orthotopic abdominal aortic allograft transplantation was performed in male rats with Brown-Norway rats used as donors and Lewis rats as recipients. The recipients (n = 50) were treated with estradiol 20 micrograms/kg per day or placebo by osmotic minipump for 2 days before the operation and until they were put to death on postoperative days 1, 3, 7, 14, or 21. The allografts were harvested and insulin-like growth factor, platelet-derived growth factor, basic fibroblast growth factor, and major histocompatibility complex class II antigen expression were determined by immunohistochemical staining. Myointimal thickening was measured by morphometric analysis. RESULTS In the placebo-treated group, insulin-like growth factor protein progressively increased in all three layers of the allograft, whereas platelet-derived growth factor protein peaked at day 3 and basic fibroblast growth factor protein increased only moderately. Estradiol treatment inhibited the continuous increase in insulin-like growth factor expression, the peak in platelet-derived growth factor expression at day 3, the moderate-basic fibroblast growth factor increase at day 21, and major histocompatibility complex class II antigen expression in all three layers of the allograft at day 21. Intimal thickening of allografts from estradiol-treated recipients was twofold to threefold less than that of the placebo-treated recipients at day 21. CONCLUSION The development of transplant arteriosclerosis is associated with an early alloimmune response involving sustained increase in insulin-like growth factor expression. Estradiol treatment of the recipient inhibits transplant arteriosclerosis and suppresses insulin-like growth factor and major histocompatibility complex class II antigen expression but not platelet-derived growth factor or basic fibroblast growth factor in all three layers of the allograft during the early posttransplantation alloimmune rejection phase.
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Foegh ML, Lou H, Chen MF, Ramwell PW. Angiopeptin induces beneficial vascular remodeling after balloon injury. Transplant Proc 1997; 29:2605-8. [PMID: 9290760 DOI: 10.1016/s0041-1345(97)00526-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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