A novel octamer binding transcription factor is differentially expressed in mouse embryonic cells

We have identified a novel octamer binding factor (Oct-3) in P19 embryonal carcinoma cells. Oct-3, which recognizes the typical octamer motif (ATTTGCAT) as well as the AT-rich sequence TTAAAATTCA, is present in P19 stem cells but disappears when the cells are induced to differentiate by retinoic acid (RA). Cloned cDNA corresponding to Oct-3 encodes a protein of 377 amino acids. Oct-3 has a conserved POU domain, but the remaining part is distinct from other POU domain-containing proteins such as Oct-1 and Oct-2. mRNA of 1.5 kb coding for Oct-3 is abundant in P19 stem cells but is dramatically repressed during RA-induced differentiation. Repression of the 1.5 kb mRNA is rapid and specific to RA. In mouse, oct-3 mRNA is undetectable in all the adult organs examined. The N-terminal proline-rich region of Oct-3, when fused to the DNA binding domain of c-Jun, functions as a transcriptional activating domain. We suggest that Oct-3 is a novel octamer binding transcription factor that is developmentally regulated during mouse embryogenesis.

Decidual and peripheral blood CD4+CD25+ regulatory T cells in early pregnancy subjects and spontaneous abortion cases

Human pregnancy represents a situation of semiallograft to maternal host. Therefore, it has been reported that tolerance to the fetal allograft represents a mechanism for maintaining a pregnancy. CD4(+)CD25(bright) regulatory T cells are known to play an important role in the development and maintenance of tolerance in peripheral tissues. However, the potential role of CD4(+)CD25(bright) T cells in maintaining human pregnancy has not been reported. In this study, we show that early human pregnancy decidua contains an abundance of CD4(+)CD25(bright) T cells, which express CD152(CTLA-4) at a high level. CD4(+)CD25(bright) T cells mediate potent inhibition of autologous T-cell proliferation by anti-CD3 stimulation. Furthermore, these cells inhibit the proliferation of autologous CD4(+)CD25(-) T cells in a dose-dependent fashion. This suppressive function of decidual CD4(+)CD25(+) T cells required cell-to-cell contact. The proportion of decidual CD4(+)CD25(bright) T cells was significantly lower in specimens from spontaneous abortion compared to those from specimens from induced abortions. These results suggest that decidual CD4(+)CD25(bright) T cells contribute to the mechanisms mediating maternal immune tolerance of conceptus antigens and therefore might contribute to the maintenance of pregnancy.

Scavenging effects of tea catechins and their derivatives on 1,1-diphenyl-2-picrylhydrazyl radical

The scavenging effects of tea catechins and their epimerized, acylated, and glucostylated derivatives on 1,1-diphenyl-2-picrythydrazyl (DPPH) radical were evaluated by electron spin resonance spectrometry. Tea catechins and their epimers were shown to have 50% radical scavenging ability in the concentration range of 1 to 3 microM. No significant differences were observed between the scavenging activities of tea catechins and their epimers, and, hence, the scavenging effects of catechins are not dependent on their sterical structure. The relationship between scavenging ability and the structure of tea catechins was also examined with acylated and glucosylated catechin derivatives. It is suggested that the galloyl moiety attached to flavan-3-ol at 3 position has a strong scavenging ability on the DPPH radical as well as the ortho-trihydroxyl group in the B ring, which elevates the radical scavenging efficiency above that of the ortho-dihydroxyl group; as has been recognized in other flavonoids such as flavones. The results obtained from the reactivity of tea catechins with the DPPH radical at different pHs suggest not only that the ortho-trihydroxyl group and the galloyl moiety contribute to maintaining the DPPH radical scavenging ability more effectively in a wide range of conditions from acidic to alkaline, but also that the radical scavenging efficiency of the ortho-dihydroxyls in the B ring is limited in neutral to alkaline regions. The difference between the scavenging abilities of the trihydroxyls (probably in the galloyl moiety) and the dihydroxyls can be explained in terms of redox potentials. It is concluded that the ortho-trihydroxyl group in the B ring and the galloyl moiety at 3 position of flavan-3-ol skeleton are the most important structural features for displaying an excellent scavenging ability on the DPPH radical.

Complete sequence and gene organization of the genome of a hyper-thermophilic archaebacterium, Pyrococcus horikoshii OT3

The complete sequence of the genome of a hyper-thermophilic archaebacterium, Pyrococcus horikoshii OT3, has been determined by assembling the sequences of the physical map-based contigs of fosmid clones and of long polymerase chain reaction (PCR) products which were used for gap-filling. The entire length of the genome was 1,738,505 bp. The authenticity of the entire genome sequence was supported by restriction analysis of long PCR products, which were directly amplified from the genomic DNA. As the potential protein-coding regions, a total of 2061 open reading frames (ORFs) were assigned, and by similarity search against public databases, 406 (19.7%) were related to genes with putative function and 453 (22.0%) to the sequences registered but with unknown function. The remaining 1202 ORFs (58.3%) did not show any significant similarity to the sequences in the databases. Sequence comparison among the assigned ORFs in the genome provided evidence that a considerable number of ORFs were generated by sequence duplication. By similarity search, 11 ORFs were assumed to contain the intein elements. The RNA genes identified were a single 16S-23S rRNA operon, two 5S rRNA genes and 46 tRNA genes including two with the intron structure. All the assigned ORFs and RNA coding regions occupied 91.25% of the whole genome. The data presented in this paper are available on the internet at http:@www.nite.go.jp.

Molecular cloning and characterization of rat estrogen receptor cDNA

A cDNA clone of rat uterus estrogen receptor (ER) has been isolated and sequenced. This clone contains a complete open reading frame encoding 600 amino acid residues which is 5 and 11 amino acids larger than the corresponding molecules of human and chicken, respectively. The molecular weight of this protein is calculated to be 67,029. When this clone was ligated to the pSV2 vector and transfected into COS7 cells, a protein was produced that had the same affinity to estrogen as rat uterus ER. This sequence shows 88% homology with human ER; 528 amino acids are identical and 14 amino acids are conservative substitutions. The comparison of rat, human and chicken ER sequences indicate the presence of three highly conserved regions suggesting that these regions play important roles in ER function. The putative DNA-binding domain is completely identical in rat, human and chicken. The C-terminal half region which is thought to be the estrogen binding domain is also highly conserved and is rich in hydrophobic amino acid residues. Southern blot analysis of genomic DNA with ER cDNA as a probe has shown that related sequences are present in the genome.

Quantitative analysis of peripheral blood Th0, Th1, Th2 and the Th1:Th2 cell ratio during normal human pregnancy and preeclampsia

We calculated the percentage of Th1, Th2, Th0 cells and the Th1:Th2 cell ratio of peripheral blood from normal pregnant subjects and preeclampsia patients using flow cytometry which can analyse both the surface marker, CD4, and intracellular cytokines, interleukin (IL)-4 and interferon (IFN)-gamma. In normal pregnancy, the percentage of Th1 cells was significantly lower in the third trimester, and the ratios of Th1:Th2 were significantly lower in the second and third trimester than in nonpregnant subjects. In contrast, the percentage of Th1 cells and the ratios of Th1:Th2 in preeclampsia were significantly higher than in normal third trimester pregnant subjects. The percentage of Th2 cells in preeclampsia was significantly lower than in third trimester of normal pregnancy. Additionally, peripheral blood mononuclear cells from these subjects and patients were cultured with phytohemagglutinin stimulation, and IL-4 and IFN-gamma concentrations were determined in the supernatant by enzymed linked immunosorbent assays. The percentage of Th1 and Th2, and the ratios of Th1:Th2 were correlated with cytokine (IFN-gamma and IL-4) secretion level. These results demonstrated that Th2 cells were predominant in the second and third trimesters of normal pregnancy, but Th1 cells predominated in preeclamptic patients.

Proportion of peripheral blood and decidual CD4(+) CD25(bright) regulatory T cells in pre-eclampsia

CD4(+) CD25(bright) regulatory T (T(reg)) cells have been identified as a principle regulator of tolerance during pregnancy. In the setting of pre-eclampsia, however, little is known about the dynamics of these cells. In the current study, we determined CD4(+) CD25(bright) T(reg) cells in the peripheral blood using flow cytometry and forkhead box P3 (FoxP3(+)) cells at the placental bed using immunohistochemical staining. Peripheral blood mononuclear cells (PBMC) of 38 pre-eclamptic cases (17 cases Japanese, 21 cases Polish), 40 normal late pregnancy subjects (20 subjects Japanese, 20 subjects Polish), and 21 non-pregnant healthy controls (10 subjects Japanese, 11 subjects Polish) were included. We found the percentage of CD25(bright) cells within the CD4(+) T cell population in PBMC was reduced significantly in both Japanese and Polish pre-eclamptic cases than in normal pregnancy subjects (P < 0.001) and non-pregnant healthy controls (P < 0.001). Also, the percentage of FoxP3(+) cells within CD3(+) T cells in the placental bed biopsy samples of pre-eclamptic cases were decreased compared to those in normal pregnancy subjects. These findings suggest that a decreased number of T(reg) cells was present in pre-eclampsia, and these changes might break the maternal tolerance to the fetus.

New and reliable MRI diagnosis for progressive supranuclear palsy

OBJECTIVE

To evaluate the area of the midbrain and pons on mid-sagittal MRI in patients with progressive supranuclear palsy (PSP), Parkinson disease (PD), and multiple-system atrophy of the Parkinson type (MSA-P), compare these appearances and values with those of normal control subjects, and establish diagnostic MRI criteria for the diagnosis of PSP.

METHODS

The authors prospectively studied MRI of 21 patients with PSP, 23 patients with PD, 25 patients with MSA-P, and 31 age-matched normal control subjects. The areas of the midbrain tegmentum and the pons were measured on mid-sagittal MRI using the display tools of a workstation. The ratio of the area of the midbrain to the area of the pons was also evaluated in all subjects.

RESULTS

The average midbrain area of the patients with PSP (56.0 mm2) was significantly smaller than that of the patients with PD (103.0 mm2) and MSA-P (97.2 mm2) and that of the age-matched control group (117.7 mm2). The values of the area of the midbrain showed no overlap between patients with PSP and patients with PD or normal control subjects. However, patients with MSA-P showed some overlap of the values of individual areas with values from patients with PSP. The ratio of the area of the midbrain to the area of pons in the patients with PSP (0.124) was significantly smaller than that in those with PD (0.208) and MSA-P (0.266) and in normal control subjects (0.237). Use of the ratio allowed differentiation between the PSP group and the MSA-P group.

CONCLUSION

The area of the midbrain on mid-sagittal MRI can differentiate PSP from PD, MSA-P, and normal aging.

Primary structures of human alpha-fetoprotein and its mRNA

DNA complementary to human alpha-fetoprotein (AFP)mRNA was cloned in the plasmid pBR322. Analysis of three overlapping cDNA clones revealed most of the nucleotide sequence of AFP mRNA, and the remaining nucleotides at the 5' end of the mRNA were elucidated from a cloned genomic DNA fragment. The amino acid sequence was deduced from the nucleotide sequence, which revealed 19 amino acids in the signal sequence and 590 amino acids in mature AFP. There are 15 regularly spaced disulfide bridges, which generate a folding structure having three repeating domains. There is one potential N-glycosylation site, Asn-Phe-Thr, in the amino acid sequence. In comparison with mouse AFP, 66% of the amino acid sequence was conserved, with the highest identity (72%) in domain 3, followed by domain 2 (67%) and domain 1 (59%). In comparison with human albumin, a 39% conservation of primary structure was found. Again, the similarity was the highest in domain 3 and the lowest in domain 1. Human AFP and human albumin are similar in overall structure, but certain parts of the molecules differ significantly in their predicted secondary structure.

Localization of a gene for Fukuyama type congenital muscular dystrophy to chromosome 9q31-33

Fukuyama type congenital muscular dystrophy (FCMD) is an autosomal recessive severe muscular dystrophy associated with an anomaly of the brain. Twenty-one FCMD families, 13 of them with consanguineous marriages, were analysed by genetic linkage analyses with polymorphic microsatellite markers to map the FCMD gene. Significant lod scores were obtained with the markers D9S58 (Zmax = 5.81 at theta = 0.06), D9S59 (Zmax = 4.33 at theta = 0.02), and HXB (Zmax = 3.28 at theta = 0.09) on chromosome 9q31-33. Multipoint analysis placed FCMD between D9S58 and D9S59, with a maximum lod score of 16.93. These markers will be useful for presymptomatic, prenatal and carrier diagnosis of family members carrying FCMD, and they represent important resources for the identification of a gene responsible for FCMD.

Cloning and the nucleotide sequence of rat glutathione S-transferase P cDNA

A cDNA library prepared from poly(A)+ RNA of 2-acetylaminofluorene (AAF) induced rat hepatocellular carcinoma was screened by synthetic DNA probes deduced from a partial amino acid sequence of glutathione S-transferase P subunit that had been isolated from the tumor by two-dimensional gel electrophoresis. One of the four clones analyzed contained an mRNA region encoding the total amino acid sequence of this enzyme subunit and the complete 3'-noncoding region. The nucleotide sequence indicates that this enzyme subunit has 209 amino acids (calculated Mr=23,307) distinct from other glutathione S-transferase subunits such as Ya and Yc. Comparison of the amino acid sequences between these proteins indicates that glutathione S-transferase P subunit gene has been evolved from the ancestral gene at an earlier stage than the separation of Ya and Yc and that there are at least three domains having a considerable homology with each other in these enzymes. The very large increase of this mRNA in chemically induced hepatocellular carcinoma suggests a characteristic derepression of this gene during hepatocarcinogenesis.

Increased T-helper-1-type immunity and decreased T-helper-2-type immunity in patients with preeclampsia

PROBLEM

To examine whether preeclampsia involves type-1 T-helper (TH1) immune hyperactivity.

METHOD OF STUDY

Expression of HLA-DR, a cell-surface marker of activation, was analyzed on CD3+, CD4+, and CD8+ T cells in 15 preeclamptic patients and 15 normal pregnant women using flow cytometry. Additionally, peripheral blood mononuclear cells from preeclamptic patients and normal pregnant women were cultured with or without phytohemagglutinin (PHA) stimulation, and interleukin (IL)-2, IL-4, interferon (IFN)-gamma, and tumor necrosis factor (TNF)-alpha concentrations were determined in the supernatant by immunoassays.

RESULTS

HLA-DR antigen was expressed more strongly on CD3+ T cells in preeclamptic patients than in normal subjects. In preeclampsia, HLA-DR was expressed more strongly in CD8+ T cells than in CD4- T cells. More TNF-alpha, IL-2, and IFN-gamma were produced by unstimulated and stimulated cultured peripheral blood mononuclear cells from preeclampsia patients than by those from normal subjects. TNF-alpha/IL-4, IL-2/IL-4, and IFN-gamma/IL-4 ratios were higher in preeclamptic patients than in the normal group. Significant positive correlations were observed between mean blood pressure and concentrations of the Th-1 type cytokines IL-2, IFN-gamma, and TNF-alpha.

CONCLUSION

Up-regulation of Th1 responses and down-regulation of Th2 responses occur in preeclampsia.

A BMP-inducible gene, dlx5, regulates osteoblast differentiation and mesoderm induction

Bone morphogenetic proteins (BMPs), members of the transforming growth factor beta superfamily, have been identified by their ability to induce cartilage and bone from nonskeletal cells and have been shown to act as a ventral morphogen in Xenopus mesoderm. We isolated a murine homeobox-containing gene, distal-less 5 (mDlx5), as a BMP-inducible gene in osteoblastic MC3T3-E1 cells. Stable transfectants of MC3T3-E1 that overexpress mDlx5 mRNA showed increase in various osteogenic markers, a fourfold increase in alkaline phosphatase activity, a sixfold increase in osteocalcin production, and appearance in mineralization of extracellular matrix. Furthermore, mDlx5 was induced orthotopically in mouse embryos treated with BMP-4 and in fractured bone of adult mice. Consistent with these observations, we also found that injection of mDlx5 mRNA into dorsal blastomeres enhanced the ventralization of Xenopus embryos. These findings suggest that mDlx5 is a target gene of the BMP signaling pathway and acts as an important regulator of both osteogenesis and dorsoventral patterning of embryonic axis.

Crystal structure of the macrophage migration inhibitory factor from rat liver

The tertiary structure of the macrophage migration inhibitory factor (MIF) from rat liver (12,300 Mr) is presented at 2.2 A resolution. Each monomer consists of two beta/alpha/beta motifs aligned in quasi two-fold symmetry, comprising a domain consisting of a four-stranded mixed beta-sheet and two antiparallel alpha-helices. The protein exists as a trimer in the crystal. An extra beta-strand that is almost perpendicular to the other beta-strands joins to the beta-sheet of the neighbouring monomer in the trimer. Unexpected similarities were detected between MIF and two kinds of isomerase.

"Congestion index" of the portal vein

The "congestion index" is used to mean the ratio between the cross-sectional area (cm2) and the blood flow velocity (cm/sec) of the portal vein, as determined by a duplex Doppler system. The indices as determined in normal subjects and patients with liver disease were as follows: normal subjects (n = 85), 0.070 +/- 0.029 cm X sec; acute hepatitis (n = 11), 0.071 +/- 0.014 cm X sec; chronic active hepatitis (n = 42) 0.119 +/- 0.084 cm X sec; cirrhosis (n = 72), 0.171 +/- 0.075 cm X sec; and idiopathic portal hypertension (n = 11), 0.180 +/- 0.107 cm X sec. There was a statistically significant difference between the congestion indices from the normal subject group and indices obtained from patients with chronic hepatitis, cirrhosis, and idiopathic portal hypertension. A weak positive correlation was obtained between the congestion index and the portal venous pressure, measured simultaneously through a percutaneously placed catheter (n = 64, r = 0.45, p less than 0.01). It is suggested that the congestion index reflects the pathophysiological hemodynamics of the portal venous system in portal hypertension.

Both Pit-1 and the estrogen receptor are required for estrogen responsiveness of the rat prolactin gene

To examine the functional relationship between distinct cis-active elements within the distal enhancer region of the rat PRL gene, we have used deletional and mutational analysis of that region in transient transfection studies in GH3 pituitary tumor cells. Results from these studies demonstrate that the region of the PRL distal enhancer containing the Pit-1-binding sites is critical not only for enhancer activity and the response to cAMP, but also for the response to estradiol. An interaction of the estrogen receptor with factors conferring basal enhancer activity is suggested by studies with a mutant distal enhancer region in which the PRL estrogen response element was converted to a palindromic estrogen response element. To directly examine potential interactions, cotransfection studies using PRL distal enhancer reporter gene constructs and expression vectors for Pit-1 and rat estrogen receptor were performed in two heterologous cell lines. The activity of the reporter gene under the control of the PRL distal enhancer linked to either the thymidine kinase promoter or the PRL proximal promoter was not significantly altered by cotransfection with the Pit-1 expression vector in COS-1 or RAT-1 cells. Coexpression of these reporter constructs and an expression vector for estrogen receptor resulted in only a slight response to estradiol. However, when both Pit-1 and estrogen receptor were cotransfected with the distal enhancer reporter gene, a marked induction was observed in response to estradiol, and this activity was dependent upon the concentration of the Pit-1 expression vector.(ABSTRACT TRUNCATED AT 250 WORDS)

Erythroid differentiation factor is encoded by the same mRNA as that of the inhibin beta A chain

We have isolated a protein that exhibits a potent differentiation-inducing activity toward mouse Friend erythroleukemia (MEL) cells and human K-562 cells. The protein, designated erythroid differentiation factor (EDF), was found in the culture fluid of human THP-1 cells that had been treated with phorbol 12-myristate 13-acetate. EDF is a homodimer with a Mr of 25,000; the Mr of the monomer is 15,500. cDNA clones encoding the Mr 15,500 subunit of EDF from THP-1 libraries were isolated and sequenced. Surprisingly, the sequence of EDF mRNA is identical to that for the beta A subunit of inhibin, a gonadal protein that suppresses the secretion of pituitary follicle-stimulating hormone. Southern blot analysis indicates that only one gene for EDF/inhibin beta A exists in the human genome. When the EDF subunit cDNA was linked to a simian virus 40 expression vector containing the dihydrofolate reductase gene and transfected into Chinese hamster ovary dihydrofolate reductase negative cells, the transformants began to secrete EDF, demonstrating that the cDNA actually encoded the EDF subunit.

Electrophysiological studies on the cerebellocerebral projections in monkeys

1. Responses evoked by stimulation of the cerebellar and thalamic nuclei were recorded by microelectrodes introduced at various depths in the cerebral cortex of monkeys (Macaca mulatta) under light Nembutal anaesthesia. 2. Stimulation of the medial (fastigial) cerebellar nucleus produced, at a latency of 4-5 msec, deep thalamo-cortical (T-C) responses (surface positive-deep negative potentials) mainly in the medial part of the precentral gyrus (area 4, "motor area for hindlimb") and in the superior parietal gyrus (area 5) on both contralateral and ipsilateral sides to the nucleus stimulated. 3. Stimulation of the lateral (dentate) cerebellar nucleus elicited, at a latency of about 3 msec, superficial T-C responses (surface negative-deep positive potentials) predominately in the lateral part of the precentral gyrus (area 4, "motor area for forelimb and face") and in the rostromedial part of the gyrus (area 6, premotor area) on the contralateral side. 4. Stimulation of the interpositus cerebellar nucleus set up superficial T-C responses chiefly in the motor area between those influenced by the medial and the lateral cerebellar nucleus stimulation and also in the premotor area on the contralateral side. 5. The respective areas responsive to the medial, interpositus and lateral nucleus stimulation overlapped considerably each other in the motor cortex. 6. Comparison of the responses in the cortex induced by stimulation of the cerebellar and thalamic nuclei indicated different relay portions in and around the VA-VL region of the thalamus for the superficial and the deep T-C responses respectively. 7. Functional implications of the results were discussed in referring to the cerebellocerebral projections in cats.

Intravenous injection of rabbit apolipoprotein A-I inhibits the progression of atherosclerosis in cholesterol-fed rabbits

The effects of intravenous injection of purified rabbit apoA-I on the progression of aortic atherosclerosis in cholesterol-fed rabbits were examined. In experiment 1, 28 rabbits were equally divided into groups A and B and fed a 0.5% cholesterol diet for 90 days. For the last 30 days, group B received 40 mg apoA-I every week. The fatty streak lesions in group B (23.9 +/- 15.6%) were significantly suppressed compared with those in group A (46.0 +/- 24.9%) (P < .05). In experiment 2, 33 rabbits were divided into four groups (8 or 9 rabbits per group) and fed a 0.5% cholesterol diet. Group A was killed on day 105, while groups B, C, and D were maintained for an additional 60 days on a normal diet, during which time groups C and D received 1 mg apoA-I every other day or 40 mg apoA-I every week, respectively. The lesions in group C (70.2 +/- 15.4%) and group D (65.7 +/- 20.0%) were significantly suppressed compared with those in group B (86.2 +/- 13.7%) (P < .05) but were not reduced to the level of group A (50.0 +/- 22.9%). Although apparent regression was not observed under these conditions, the present study provided the first evidence for the antiatherogenic effect of homologous and apoA-I on the progression of atherosclerosis in cholesterol-fed rabbits.

Molecular analysis of external genitalia formation: the role of fibroblast growth factor (Fgf) genes during genital tubercle formation

The molecular mechanisms underlying the development of the external genitalia in mammals have been very little examined. Recent gene knockout studies have suggested that the developmental processes of its anlage, the genital tubercle (GT), have much in common with those of limb buds. The Fgf genes have been postulated as regulating several downstream genes during organogenesis. Fgf8 was expressed in the distal urethral plate epithelium of the genital tubercle (GT) together with other markers such as the Msx1, Fgf10, Hoxd13 and Bmp4 expressed in the mesenchyme. To analyze the role of the FGF system during GT formation, an in vitro organ culture system was utilized. It is suggested that the distal urethral plate epithelium of GT, the Fgf8-expressing region, regulates the outgrowth of GT. Ectopic application of FGF8 beads to the murine GT induced mesenchymal gene expression, and also promoted the outgrowth of the GT. Experiments utilizing anti-FGF neutralizing antibody suggested a growth-promoting role for FGF protein(s) in GT outgrowth. In contrast, despite its vital role during limb-bud formation, Fgf10 appears not to be primarily essential for initial outgrowth of GT, as extrapolated from Fgf10(−/−) GTs. However, the abnormal external genitalia development of Fgf10(−/−) perinatal mice suggested the importance of Fgf10 in the development of the glans penis and the glans clitoridis. These results suggest that the FGF system is a key element in orchestrating GT development.

Scavenger receptors for oxidized and glycated proteins

Our present knowledge on chemically modified proteins and their receptor systems is originated from a proposal by Goldstein and Brown in 1979 for the receptor for acetylated LDL which is involved in foam cell formation, one of critical steps in atherogenesis. Subsequent extensive studies using oxidized LDL (OxLDL) as a representative ligand disclosed at least 11 different scavenger receptors which are collectively categorized as "scavenger receptor family". Advanced glycation endproducts (AGE) and their receptor systems have been studied independently until recent findings that AGE-proteins are also recognized as active ligands by scavenger receptors including class A scavenger receptor (SR-A), class B scavenger receptors such as CD36 and SR-BI, type D scavenger receptor (LOX-1) and FEEL-1/FEEL-2. Three messages can be summarized from these experiments; (i) endocytic uptake of OxLDL and AGE-proteins by macrophages or macrophage-derived cells is mainly mediated by SR-A and CD36, which is an important step for foam cell formation in the early stage of atherosclerosis, (ii) selective uptake of cholesteryl esters of high density lipoprotein (HDL) mediated by SR-BI is inhibited by AGE-proteins, suggesting a potential pathological role of AGE in a HDL-mediated reverse cholesterol transport system, (iii) a novel scavenger receptor is involved in hepatic clearance of plasma OxLDL and AGE-proteins.