Biomedical subjects

Jun Zou

Publications and source records attributed to Jun Zou.

At least 19 recordsLinked to original sources

PubMed2026

Identification and differential regulation of proteasome β family genes by viral infection and cytokines in grass carp (Ctenopharyngodon idella).

Proteasome β (PSMB) subunits are essential components of the proteasome complex and play important roles in antigen processing and immune regulation. In this study, we identified 14 Psmb genes in grass carp (Ctenopharyngodon idella), including seven constitutive Psmbs (Psmb1-7), three immunoproteasome genes (Psmb8-10), two thymoproteasome-related paralogs (Psmb11a and Psmb11b), and two telelost-specific members (Psmb12 and Psmb13). Comparative genomic analyses showed that grass carp Psmb genes are highly conserved in genomic organization, gene synteny, and predicted β-subunit-like protein structures, supporting the evolutionary conservation of the proteasome β-subunit family in fish. Phylogenetic and syntenic analyses further revealed lineage-specific expansion of immunoproteasome-related Psmb genes in teleost fish, with Psmb12 and Psmb13 likely derived from duplications of Psmb9 and Psmb10, respectively. Tissue expression analysis suggested functional divergence among duplicated Psmb members, as constitutive Psmbs were relatively enriched in the brain, whereas immunoproteasome-related and teleost-specific Psmbs were highly expressed in immune- and mucosa-associated tissues. Moreover, GCRV-I infection rapidly induced Psmb8-10 and Psmb11b expression in CIK cells. IFN-γ induced a broader set of Psmb genes than IFNa, whereas IL-10 selectively suppressed several Psmbs. Together, these findings highlight the evolutionary conservation, expansion, and immune-related diversification of the Psmb family in teleost fish.

Animals↗

PubMed2026

Metagenomic next-generation sequencing of cerebrospinal fluid reveals pathogen spectrum and mortality predictors among patients with advanced HIV-1 disease at a tertiary hospital in China.

BACKGROUND: Central nervous system (CNS) infections remain the major causes of morbidity and mortality among people living with HIV-1 (PLWH), particularly in resource-limited settings. However, the clinical characteristics and prognostic indicators of PLWH with suspected CNS infections are not well defined. In this study, we aim to characterize the spectrum of CNS pathogens, clinical characteristics, in-hospital mortality, and factors associated with death among people with advanced HIV-1 disease (AHD) in Guangxi, China. METHODS: Metagenomic next-generation sequencing (mNGS) was performed to analyze types of infection in cerebrospinal fluid (CSF) from 61 treatment-naive PLWH with suspected CNS infections. Clinical data, routine laboratory tests, and biochemical tests were collected and analyzed. RESULTS: Among the 61 CSF samples, primarily with AHD, a total of 206 pathogens were identified. Viral pathogens predominated, with Epstein-Barr virus being the most frequently identified, followed by cytomegalovirus. Compared with patients with single-pathogen infection, those with multiple infections (viral, bacterial, and fungal) exhibited significantly lower CD4 T cell counts, higher C-reactive protein levels, and markedly reduced lipid metabolism parameters. However, infection types were not significantly associated with in-hospital death. Multivariate logistic regression analysis identified plasma low density lipoprotein (LDL) and CSF lactate dehydrogenase (LDH) as independent predictors of in-hospital death. CONCLUSION: In PLWH with AHD and suspected CNS infections, multiple pathogens frequently coexist in the CSF. Plasma LDL and CSF LDH levels were independent predictors of death, indicating their potential value as early risk stratification in AHD.

Humans↗

PubMed2006

Cloning, promoter analysis and expression in response to bacterial exposure of sea bass (Dicentrarchus labrax L.) interleukin-12 p40 and p35 subunits.

Interleukin-12 (IL-12) is a heterodimeric cytokine pivotal in resistance to microbial and viral infections. In the search for immunoregulatory genes in sea bass the genes for the two IL-12 subunits p40 and p35 were cloned and sequenced. Molecular characterization of these two genes was performed at both the cDNA and genomic levels. Sea bass IL-12 p40 and p35 conserve most cysteines involved in the intra-chain disulfide bonds of human IL-12 subunits as well as the important structural residues for human IL-12 heterodimerization. The gene organization of sea bass IL-12 p40 is similar to the human orthologue, whilst the sea bass IL-12 p35 gene structure, as reported for pufferfish, differs from the human one in containing an additional exon and lacking a second copy of a duplicated exon present in the mammalian genes. The promoter analysis of both sea bass and pufferfish IL-12 genes showed the presence of the main cis-acting elements involved in the transcriptional regulation of human and mouse orthologues. The involvement of IL-12 in sea bass anti-bacterial immune responses was demonstrated by investigating the expression profiles of IL-1beta, IL-12 p40 and p35 in the head-kidney and spleen following intraperitoneal injection of UV-killed and live Photobacterium damselae ssp. piscicida (Phdp). Finally, the importance of nuclear factor (NF)-kappaB on UV-killed Phdp-induced IL-12 p40 and p35 gene transcription was shown by the use of pyrrolidine dithiocarbamate (PDTC).

Amino Acid Sequence↗

PubMed2006

Infectious pancreatic necrosis virus suppresses type I interferon signalling in rainbow trout gonad cell line but not in Atlantic salmon macrophages.

RTG-P1 cells are a rainbow trout fibroblastic cell line permanently transfected with the luciferase gene under the control of the Mx promoter. On exposure to interferon (IFN) or IFN inducing agents, the cells produce luciferase. IPNV did not induce luciferase production up to 24h post-infection but did not suppress constitutive luciferase production. Furthermore, IPNV suppressed luciferase production induced by poly I:C. RT-PCR analysis of IPNV infected cells showed IFN gene transcription from 6h post-infection with increasing expression up to 24h. Housekeeping genes beta-actin and GAPDH were also expressed along with upregulation of IRF1 and slight upregulation of STAT1. When RTG-P1 cells were stimulated with IFN, Mx transcripts, measured by qRT-PCR, peaked at 3-6h and thereafter fell to low levels, but in the presence of IPNV, Mx transcription at this time was significantly suppressed but continued to rise gradually. Luciferase production was lower in infected cells at 12h post-infection but not significantly after 24h. These results indicate that, in non-stimulated RTG-P1 cells, while IPNV induces IFN transcription, activation of Mx expression is suppressed. Furthermore, when stimulated by IFN, the rate of Mx transcription is significantly suppressed by the virus. This would probably give time for the virus to replicate rapidly in the early phases of infection. Contrary to the fibroblastic cell line, IPNV stimulated IFN production by salmon macrophages in vitro at least as strongly as poly I:C, with no suppression of the IFN response to poly I:C, and the virus persisted for up to 9 days without causing CPE.

Animals↗

PubMed2006

Discovery of multiple beta-defensin like homologues in teleost fish.

Using a database mining approach, multiple defensin like genes have been discovered for the first time in fish, in species including zebrafish Danio rerio and the pufferfish, Takifugu rubripes and Tetraodon nigroviridis. They share the common features of vertebrate defensins, including small size, net cationic charge, and six conserved cysteines in the mature region. Based on their cysteine arrangement, the identified fish defensin like peptides resemble beta-defensin family members in birds and mammals. Computing modelling detected three beta-strands in all three zebrafish defensins and an extra N-terminal alpha-helix in one of the peptides. The coding regions of the fish genes contain three exons and two introns, the same as avian defensin genes. In zebrafish and tetraodon, two defensin genes identified are located in the same chromosome. An additional locus containing a third defensin gene has also been found in a different chromosome in zebrafish, demonstrating that multiple defensin loci may be present in fish. Comparative studies suggest that beta-defensins may represent the primitive form of the defensin family, which expanded during evolution by gene or genome duplication. In healthy zebrafish, constitutive expression of defensins was detected by RT-PCR in gill, gonad, gut, kidney, muscle, skin and spleen but the levels and patterns varied for individual defensin genes.

Amino Acid Sequence↗

PubMed2006

Molecular and expression analysis of an interferon-gamma-inducible guanylate-binding protein from rainbow trout (Oncorhynchus mykiss).

Guanylate-binding proteins (GBPs) are some of the most abundant proteins accumulating in mammalian cells in response to interferon-gamma (IFN-gamma). GBPs have been suggested to function in antiviral activity, macrophage activation, fibroblast proliferation and inhibition of endothelial cell proliferation and invasiveness. Here we confirm that IFN-gamma-inducible GBP also exist in fish. A 2 kb GBP cDNA was cloned from head kidney of rainbow trout treated with an IFN-inducing compound. The open reading frame predicts a 635 amino acid protein (rbtGBP) of 72.7 kDa possessing a tripartite GTP binding motif and a secondary structure similar to human GBP1. Like most mammalian GBPs, rbtGBP possesses an isoprenylation motif at the C-terminal end. The overall amino acid sequence identity between rbtGBP and mammalian GBPs is only 41-47%, however. The rainbow trout macrophage cell line RTS11 showed a dose-dependent increase in rbtGBP transcripts in response to IFN-gamma after 6h of stimulation, with rbtGBP being undetectable in non-treated RTS11 cells. Moreover, polyinosinic polycytidylic acid (poly I:C) induced increased GBP transcript levels in RTS11 and RTG2 cells after 4-6 h of stimulation, and in head kidney and liver of live fish after 24 h. These studies suggest that rbtGBP is an early response gene in rainbow trout, which may have similar functions in IFN-gamma mediated responses as mammalian GBPs.

Amino Acid Sequence↗

PubMed2006

Upregulation of nestin, vimentin, and desmin in rat podocytes in response to injury.

Podocytes in the renal glomerulus express unusual intermediate filament (IF) proteins for epithelial cells. To gain insight into the role of IF proteins in podocytes, we investigated the expression of nestin, vimentin, and desmin in puromycin aminonucleoside (PAN) nephrosis. A Western blot analysis for nestin, vimentin, and desmin demonstrated their exclusive expression in glomeruli and showed their increase in expression in nephrotic glomeruli. Immunolocalization studies showed nestin and vimentin to be located predominantly in the podocytes in both normal and nephrotic glomeruli and that enhancement of desmin staining only occurred in podocytes. A ribonuclease protection assay showed high levels of vimentin and nestin expression in normal glomeruli and an upregulation of all three IF transcripts in nephrotic glomeruli. One day after the PAN injection, however, the vimentin transcripts were found to already have significantly increased, whereas those of nestin or desmin showed no such increase. These findings indicate that podocytes express three IF proteins, namely, vimentin, desmin, and nestin, which are differentially regulated in response to injury. An upregulation of IF proteins may increase the mechanical stability of cells, thus enabling podocytes to undergo morphological changes on the tensile glomerular capillary wall.

Animals↗

PubMed2006

Two cathelicidin genes are present in both rainbow trout (Oncorhynchus mykiss) and atlantic salmon (Salmo salar).

Further to the previous finding of the rainbow trout rtCATH_1 gene, this paper describes three more cathelicidin genes found in salmonids: two in Atlantic salmon, named asCATH_1 and asCATH_2, and one in rainbow trout, named rtCATH_2. All the three new salmonid cathelicidin genes share the common characteristics of mammalian cathelicidin genes, such as consisting of four exons and possessing a highly conserved preproregion and four invariant cysteines clustered in the C-terminal region of the cathelin-like domain. The asCATH_1 gene is homologous to the rainbow trout rtCATH_1 gene, in that it possesses three repeat motifs of TGGGGGTGGC in exon IV and two cysteine residues in the predicted mature peptide, while the asCATH_2 gene and rtCATH_2 gene are homologues of each other, with 96% nucleotide identity. Salmonid cathelicidins possess the same elastase-sensitive residue, threonine, as hagfish cathelicidins and the rabbit CAP18 molecule. The cleavage site of the four salmonid cathelicidins is within a conserved amino acid motif of QKIRTRR, which is at the beginning of the sequence encoded by exon IV. Two 36-residue peptides corresponding to the core part of rtCATH_1 and rtCATH_2 were chemically synthesized and shown to exhibit potent antimicrobial activity. rtCATH_2 was expressed constitutively in gill, head kidney, intestine, skin and spleen, while the expression of rtCATH_1 was inducible in gill, head kidney, and spleen after bacterial challenge. Four cathelicidin genes have now been characterized in salmonids and two were identified in hagfish, confirming that cathelicidin genes evolved early and are likely present in all vertebrates.

Amino Acid Sequence↗

PubMed2005

The identification and characterization of two phosphatidylinositol-4,5-bisphosphate 4-phosphatases.

Numerous inositol polyphosphate 5-phosphatases catalyze the degradation of phosphatidylinositol-4,5-bisphosphate (PtdIns-4,5-P(2)) to phosphatidylinositol-4-phosphate (PtdIns-4-P). An alternative pathway to degrade PtdIns-4,5-P(2) is the hydrolysis of PtdIns-4,5-P(2) by a 4-phosphatase, leading to the production of PtdIns-5-P. Whereas the bacterial IpgD enzyme is known to catalyze this reaction, no such mammalian enzyme has been found. We have identified and characterized two previously undescribed human enzymes, PtdIns-4,5-P(2) 4-phosphatase type I and type II, which catalyze the hydrolysis of PtdIns-4,5-P(2) to phosphatidylinositol-5-phosphate (PtdIns-5-P). Both enzymes are ubiquitously expressed and localize to late endosomal/lysosomal membranes in epithelial cells. Overexpression of either enzyme in HeLa cells increases EGF-receptor degradation upon EGF stimulation.

Amino Acid Motifs↗

PubMed2005

Identification and expression analysis of lymphotoxin-beta like homologues in rainbow trout Oncorhynchus mykiss.

A lymphotoxin-beta (LT-beta) gene has been cloned and sequenced in rainbow trout and provides the first conclusive evidence for the existence of LT-beta in teleost. Two isoforms of LT-beta were isolated. LT-beta1 cDNA was composed of 952 bp (with a 139 bp 5'-UTR and a 201 bp 3'-UTR) and LT-beta2 cDNA was 836 bp (with a 237 bp 5'-UTR and a 197 bp 3'-UTR) both of which translated into a protein of 203 amino acid residues. Both isoforms contained a predicted transmembrane domain of 21 amino acid residues (Leu11-Val31) and the TNF family signature (Val104-Phe120). Homology and phylogenetic analysis of trout LT-beta's with other known TNF family member showed good similarity to TNF-N (teleost) and other LT-beta (mammals and frog). LT-beta1 and TNF-alpha (1 and 2) genes were highly expressed in unstimulated trout head kidney, spleen, gill and intestine, whereas LT-beta2 was weakly expressed only in the gill. The expression of LT-beta1 and -beta2 genes was not found in macrophage (RTS-11) and fibroblast (RTG-2) like cell lines, although the TNF-alpha2 gene was expressed in both cell lines with the TNF-alpha1 gene only expressed in RTS-11 cells. In head kidney cells, expression of LT-beta1 and TNF-alpha (1, 2) genes was increased by stimulation with PHA or LPS. The discovery of trout LT-beta will allow a more complete analysis of fish inflammatory responses.

Adjuvants, Immunologic↗

PubMed2005

Identification and bioactivities of IFN-gamma in rainbow trout Oncorhynchus mykiss: the first Th1-type cytokine characterized functionally in fish.

IFN-gamma is one of the key cytokines in defining Th1 immune responses. In this study, an IFN-gamma homologue has been identified in rainbow trout Oncorhynchus mykiss, and its biological activities have been characterized. The trout IFN-gamma cDNA is 1034 bp in length and translates into a 180-aa protein. The first intron of the trout IFN-gamma gene contains highly polymorphic GACA minisatellites and 44-bp DNA repeats, giving rise to at least six alleles. IFN-gamma is structurally conserved among vertebrates, and a signature motif has been identified. A nuclear localization sequence known to be crucial for IFN-gamma biological activities is also present in the C-terminal region of the trout IFN-gamma. The IFN-gamma expression was induced in head kidney leukocytes by stimulation with PHA or poly(I:C) and in kidney and spleen of fish injected with poly(I:C). rIFN-gamma produced in Escherichia coli significantly stimulated gene expression of IFN-gamma-inducible protein 10 (gammaIP-10), MHC class II beta-chain, and STAT1, and enhanced respiratory burst activity in macrophages. Deletion of 29-aa residues from the C terminus containing the nuclear localization sequence motif resulted in loss of activity with respect to induction of gammaIP-10 in RTS-11 cells. Moreover, IFN-gamma-induced gammaIP-10 expression was completely abolished by the protein kinase C inhibitor staurosporine, and partially reduced by U0126, a specific inhibitor for ERKs. Taken together, the present study has demonstrated for the first time a functional IFN-gamma homologue in a fish species, strongly suggesting a conserved Th1 immune response is most likely present in lower vertebrates.

Amino Acid Sequence↗

PubMed2005

ADAM33 enzyme properties and substrate specificity.

ADAM33 is an asthma susceptibility gene recently identified through a genetic study of asthmatic families [van Eerdewegh, et al. (2002) Nature 418, 426-430]. To understand the function of the gene product, the recombinant metalloproteinase domain of human ADAM33 was purified and tested for its substrate cleavage specificity using peptides derived from beta-amyloid precursor protein (APP). A single Ala substitution at the P2 position of a 10-residue APP peptide, YEVHHQKLVF, yielded a 20-fold more efficient substrate. Terminal truncation studies identified a minimal nine-residue core (P5-P4') important for ADAM33 recognition and cleavage. Full positional scanning of the 10-mer peptide using the 19 naturally occurring l-amino acids (excluding Cys) revealed a substrate specificity profile. A strong preference for Val or Ile at P3, Ala at P2, and Gln at P1' was observed. The substrate binding model based on the X-ray structure of the ADAM33-inhibitor complex supported the observed substrate specificity profile. On the basis of this, an improved substrate was designed and a fluorescence resonance energy transfer (FRET) assay was developed using a fluorogenic derivative of this substrate. Kinetic studies confirmed that the best substrate, FRET-P2 [K(Dabcyl)YRVAFQKLAE(Edans)K], was approximately 100-fold more efficient than the wild-type APP peptide substrate, with a k(cat)/K(m) value of (3.6 +/- 0.1) x 10(4) s(-)(1) M(-)(1). Using this substrate and the FRET assay, ADAM33 enzyme activity and thermal stability were characterized. ADAM33 dependence on buffer conditions, detergents, and temperature was examined, and optimal conditions were defined. Accurate K(i) values for tissue inhibitors of metalloproteinase and small molecule compounds were obtained.

ADAM Proteins↗

PubMed2005

Characterisation and expression analysis of an interleukin 6 homologue in the Japanese pufferfish, Fugu rubripes.

The first IL-6 sequence in fish has been determined in Fugu rubripes by exploiting the synteny that is found between some regions of the human and Fugu genomes. The predicted 227 aa IL-6 homologue contains the IL-6/G-CSF/MGF motif, has a predicted secondary structure of four alpha-helixes but only contains two of the four cysteines important in disulphide bond formation. It shows low amino acid identities (20-29%) with known IL-6 sequences, although phylogenetic analysis groups the Fugu molecule with the other IL-6 molecules. The gene organisation of Fugu IL-6 and the level of synteny between the human and Fugu genomes has been well conserved during evolution with the order and orientation of the genes matching exactly to human chromosome 7. PHA stimulation of Fugu kidney cells resulted in a large increase in the Fugu IL-6 transcript, whereas LPS and Poly I:C resulted in a significant increase within spleen cells. The discovery of IL-6 in fish will now allow more detailed investigations of local inflammatory responses.

Amino Acid Sequence↗

PubMed2005

Identification of a novel cathelicidin gene in the rainbow trout, Oncorhynchus mykiss.

We report the cloning of a novel antimicrobial peptide gene, termed rtCATH_1, found in the rainbow trout, Oncorhynchus mykiss. The predicted 216-residue rtCATH_1 prepropeptide consists of three domains: a 22-residue signal peptide, a 128-residue cathelin-like region containing two identifiable cathelicidin family signatures, and a predicted 66-residue C-terminal cationic antimicrobial peptide. This predicted mature peptide was unique in possessing features of different known (mammalian) cathelicidin subgroups, such as the cysteine-bridged family and the specific amino-acid-rich family. The rtCATH_1 gene comprises four exons, as seen in all known mammalian cathelicidin genes, and several transcription factor binding sites known to be of relevance to host defenses were identified in the 5' flanking region. By Northern blot analysis, the expression of rtCATH_1 was detected in gill, head kidney, and spleen of bacterially challenged fish. Primary cultures of head kidney leukocytes from rainbow trout stimulated with lipopolysaccharide or poly(I x C) also expressed rtCATH_1. A 36-residue peptide corresponding to the core part of the fish cathelicidin was chemically synthesized and shown to exhibit potent antimicrobial activity and a low hemolytic effect. Thus, rtCATH_1 represents a novel antimicrobial peptide gene belonging to the cathelicidin family and may play an important role in the innate immunity of rainbow trout.

Animals↗

PubMed2005

[The effect of four kinds of traditional Chinese herbal compound on the experimental acute stress behaviors and the hypothalamus-pituitary-adrenal gland axis].

OBJECTIVE: To study the effects of four kinds of traditional Chinese herbal compound, Sini powder, Banxiahoupu soup, Ganmaidazao soup and Guizhigancaolonggumuli soup, on the experimental acute stress behaviors and the hypothalamus-pituitary-adrenal gland axis. METHOD: Rats were divide into 7 groups: normal group, model 1 and 2 groups, Sini powder group, Banxiahoupu soup group, Ganmaidazao soup group, and Guizhigancaolonggumuli soup group. The behaviors of the rats and their CRH of the hypothalamus, ACTH of plasma and CORT of serum (by the means of radio-immunity) were detected. RESULT: Sini powder could reduce the crossing times of open-field test( P < 0.01) and the contents of CRH and CORT (P < 0.01, P < 0.05); Banxiahoupu soup could extent the still time of tail-hanging test ( P < 0.05) and the content of CRH (P < 0.05); Ganmaidazao soup could prolong the still time (P < 0.05) and reduce the struggle times (P < 0.01) of tail-hanging test and reduce the contents of CRH, ACTH and CORT (P < 0.01, P < 0.05); Guizhigancaolonggumuli soup could reduce the crossing times of open-field test (P < 0.01) , extent the still time (P < 0.05) and reduce the struggle times ( P < 0.01) of tail-hanging test of tail-hanging test, also reduce the contents of CRH, ACTH and CORT (P < 0.01, P < 0.05). CONCLUSION: The four kinds of traditional Chinese herbal compound can increase the ability of anti stress by affect the different taches of the hypothalamus-pituitary-adrenal gland axle and change the stress behaviors, which are based on their respective functions of regulating Qi, dispersing phlegm, tonifying Qi and warming Yang.

Adrenocorticotropic Hormone↗

PubMed2004

Characterisation and expression analysis of interleukin 2 (IL-2) and IL-21 homologues in the Japanese pufferfish, Fugu rubripes, following their discovery by synteny.

This investigation provides the first conclusive evidence for the existence of the interleukin 2 (IL-2) and IL-21 genes in bony fish. The IL-2 and IL-21 sequences have been determined in Fugu rubripes by exploiting the conservation of synteny that is found between regions of the human and Fugu genomes. The predicted 149-amino acid IL-2 homologue contains the IL-2 family signature, has a predicted secondary structure of three alpha helixes and has the two cysteines important in disulphide-bond formation. It shows low amino acid identities (24-34%) with other known IL-2 sequences. The predicted 155-amino acid IL-21 homologue has a predicted secondary structure of four alpha helixes and has the four cysteines important in disulphide-bond formation. It shows low amino acid identities (29-31%) with other known IL-21 sequences. The gene organisation of Fugu IL-2 and IL-21 and the level of synteny between the human and Fugu genomes has been well conserved during evolution, with the order and orientation of the genes matching exactly to human Chromosome 4. Phytohaemagglutinin stimulation of Fugu kidney cells resulted in a large increase in the Fugu IL-2 and IL-21 transcripts. In vivo stimulation of Fugu with LPS and poly I:C showed IL-21 expression to be localised within mucosal tissues. The discovery of IL-2 and IL-21 in fish will now allow more detailed investigations into T-helper cell responses.

Amino Acid Sequence↗

PubMed2004

Peptides specific to the galectin-3 carbohydrate recognition domain inhibit metastasis-associated cancer cell adhesion.

Intravascular cancer cell adhesion plays a significant role in the metastatic process. Studies indicate that galectin-3, a member of the galectin family of soluble animal lectins, is involved in carbohydrate-mediated metastatic cell heterotypic (between carcinoma cells and endothelium) and homotypic (between carcinoma cells) adhesion via interactions with the tumor-specific Thomsen-Friedenreich glycoantigen (TFAg). We hypothesized that blocking the galectin-3 carbohydrate recognition domain with synthetic peptides would significantly reduce metastasis-associated carcinoma cell adhesion. To test this hypothesis, we identified peptide antagonists of the galectin-3 carbohydrate recognition domain using combinatorial bacteriophage display technology. The peptides bound with high affinity to purified recombinant galectin-3 protein (K(d) approximately 17-80 nM) and to cell surface galectin-3. Experiments with a series of recombinant serially truncated galectin-3 mutants indicated that the peptides bound the carbohydrate recognition domain of galectin-3. Furthermore, the peptides did not bind the carbohydrate recognition domain of other galectins and plant lectins. Synthetic galectin-3 carbohydrate recognition domain-specific peptides blocked the interaction between galectin-3 and TFAg and significantly inhibited rolling and stable heterotypic adhesion of human MDA-MB-435 breast carcinoma cells to endothelial cells under flow conditions, as well as homotypic tumor cell aggregation. These results demonstrate that carbohydrate-mediated, metastasis-associated tumor cell adhesion could be inhibited efficiently with short synthetic peptides which do not mimic naturally occurring glycoepitopes yet bind to the galectin-3 carbohydrate recognition domain with high affinity and specificity.

Antigens, Tumor-Associated, Carbohydrate↗

PubMed2004

Crystal structure of the catalytic domain of human ADAM33.

Adam33 is a putative asthma susceptibility gene encoding for a membrane-anchored metalloprotease belonging to the ADAM family. The ADAMs (a disintegrin and metalloprotease) are a family of glycoproteins implicated in cell-cell interactions, cell fusion, and cell signaling. We have determined the crystal structure of the Adam33 catalytic domain in complex with the inhibitor marimastat and the inhibitor-free form. The structures reveal the polypeptide fold and active site environment resembling that of other metalloproteases. The substrate-binding site contains unique features that allow the structure-based design of specific inhibitors of this enzyme.

ADAM Proteins↗