Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CD36”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources
PubMed1992

Thrombospondin sequence motif (CSVTCG) is responsible for CD36 binding.

To clarify the role of CD36 as a TSP receptor and to investigate the mechanisms of the TSP-CD36 interaction, transfection studies were performed using CD36-cDNA in a CDM8 plasmid. Jurkat cells transfected with CD36 cDNA express an 88kD membrane surface protein and acquire the ability to bind thrombospondin. The TSP amino acid sequence, CSVTCG, mediates the interaction of thrombospondin with CD36. CD36 transfectants but not control transfectants bind radiolabeled tyrosinated peptide (YCSVTCG). The hexapeptide inhibits thrombospondin expression on activated human platelets and results in diminished platelet aggregation. CSVTCG-albumin conjugates support CD36-dependent adhesion of tumor cells. We conclude that the CSVTCG repeat sequence is a crucial determinant of CD36 thrombospondin binding.

Amino Acid Sequence↗
PubMed2004

RRR-alpha-tocopherol decreases the expression of the major scavenger receptor, CD36, in human macrophages via inhibition of tyrosine kinase (Tyk2).

The class B scavenger receptor, CD36, binds to oxidized LDL (OxLDL), is present in atherosclerotic lesions, and is upregulated by OxLDL or AcLDL. Previously we have shown that RRR-alpha-tocopherol (AT) enrichment of human monocyte-derived macrophages inhibited OxLDL or AcLDL induced CD36 expression. The mechanism by which AT inhibited CD36 expression is not known. In the present study, we explored the mechanism by which AT decreases CD36 expression in human macrophages. Macrophages were enriched with AT (100 microM) or N-acetyl cysteine (NAC, 6 mM) overnight and then incubated with oxLDL or AcLDL for 48 h. The effect of protein kinase C inhibitors, and tyrosine kinase inhibitors on OxLDL or AcLDL-induced CD36 expression was quantitated by flow cytometry. Protein kinase C inhibitors or NAC had no effect while there was a significant inhibition with tyrosine kinase inhibitors (P < 0.01). OxLDL or AcLDL significantly increased tyrosine kinase activity which was significantly inhibited by pre-incubation with AT or with tyrosine kinase inhibitors. Western blotting revealed an increase in Tyk2 as well as phosphotyk2 with OxLDL or AcLDL. Immunoprecipitation of CD36 followed by Western blotting with Tyk2 antibodies revealed that Tyk2 was associated with CD36. In conclusion, this study demonstrates an additional direct cellular effect of AT, i.e. inhibition of CD36 expression via inhibition of tyrosine kinase (Tyk2).

Antioxidants↗
PubMed2004

Enzymatically modified low-density lipoprotein upregulates CD36 in low-differentiated monocytic cells in a peroxisome proliferator-activated receptor-gamma-dependent way.

Peroxisome proliferator-activated receptor-gamma (PPARgamma) has been suggested to upregulate CD36. Since free oxidized polyunsaturated fatty acids are PPARgamma ligands, we studied the effects of LDL modified by the simultaneous action of sPLA2 and 15-lipoxygenase (15LO) on CD36 expression and PPARgamma activation in monocytic cells. Exposure of MM6 cells, which do not express CD36 or other scavenger receptors, to such enzymatically modified LDL (enzLDL) resulted in upregulation of CD36 surface protein and mRNA expression. Similar effects were observed with free 13-hydroperoxyoctadecadienoic acid but not its esterified counterpart. Less pronounced effects were observed with LDL modified by 15LO alone. Upregulation of CD36 was inversely correlated to the state of cell differentiation, as showed by lower response to enzLDL of the scavenger receptor-expressing MM6-sr and THP1 cells. Importantly, LDL modified by sPLA2 and 15LO did not efficiently induce upregulation CD36 in PPARgamma-deficient macrophage-differentiated embryonic stem cells confirming a role of PPARgamma in CD36 expression in cells stimulated with enzLDL. Our data show that LDL modified with physiologically relevant enzymes stimulates CD36 expression in non-differentiated monocytes and that this process involves PPARgamma activation. These effects of enzLDL can be considered pro-atherogenic in the context of early atherosclerosis.

Arachidonate 15-Lipoxygenase↗
PubMed2006

Modulation of CD36 protein expression by AGEs and insulin in aortic VSMCs from diabetic and non-diabetic rats.

BACKGROUND AND AIM: In type 2 diabetes, the interplay between cells and inflammatory mediators up-regulates CD36 expression in macrophages. The aim of this work was to investigate advanced glycation end products (AGE)-induced CD36 expression and its regulation by insulin in aortic vascular smooth muscle cells (VSMCs) from Goto-Kakisaki (GK) rats, a non-obese insulin model of both insulin resistance and type 2 diabetes. The context of overexpression of CD36 in aortas was also evaluated. METHODS AND RESULTS: VSMCs were isolated and cultured from the aortas of GK rats and non-diabetic rats. The expression of proteins was evaluated by Western blot. The aortic production of superoxide anion (O(2)(.-)) was measured by luminescence on isolated tissue. AGEs and advanced oxidation protein products (AOPPs) were determined in plasma by fluorescence spectroscopy and spectrophotometry, respectively. AGE receptor (RAGE), NF-kappaB, and CD36 protein expression as well as O(2)(.-) production were higher in GK aortas than in control aortas, and AGEs and AOPPs were higher in GK plasma. In VSMCs from non-diabetic rats, insulin was able to reduce (10 nM) or suppress (100 nM) the protein overexpression of CD36 induced by AGEs-BSA. In contrast, in VSMCs from GK rats, insulin was unable to reduce AGEs-BSA-induced CD36 overexpression. CONCLUSIONS: The results suggest an overexpression of CD36 in VSMCs from GK rats and impaired control by insulin. In the context of increased plasma AGEs, aortic RAGE overexpression and increased oxidative stress markers, the data are compatible with an AGEs induced CD36 overexpression in diabetes.

Animals↗
PubMedDate not supplied

CD36, serves as a receptor for advanced glycation endproducts (AGE).

Interaction of advanced glycation endproducts (AGE) with AGE receptors induces several cellular phenomena relating potentially to diabetic complications. Five AGE receptors identified so far are receptor for AGE (RAGE), 80 K-H, OST-48, galectin-3, and macrophage scavenger receptor, types I and II (SR-A) [Eur. J. Biochem. 230 (1995) 408; Nature 386 (1997) 292.]. Since SR-A is known to belong to the class A scavenger receptor family and the scavenger receptor collectively represents a family of multiligand lipoprotein receptors, it is possible that CD36 belonging to class B scavenger receptor family (SR-B) can recognize AGE proteins as a ligand. This was tested in the present study at the cellular level by using Chinese hamster ovary (CHO) cells overexpressing human CD36 (CHO-CD36 cells). 125I-AGE-bovine serum albumin (BSA) was endocytosed in a dose-dependent fashion and underwent lysosomal degradation by CHO-CD36, but not wild-type CHO cells. Endocytic uptake of 125I-AGE-BSA by these cells was inhibited 50% by oxidized low-density lipoprotein (Ox-LDL) and 60% by FA6-152, an anti-CD36 antibody inhibiting cellular binding of Ox-LDL. Our results indicate that CD36 expressed by these cells mediates endocytic uptake and subsequent intracellular degradation of AGE proteins. Since CD36 is one of the major Ox-LDL receptors and is up-regulated in macrophage- and smooth muscle cell-derived foam cells in human atherosclerotic lesions, the present results suggest that, like Ox-LDL, AGE proteins generated in situ are recognized by CD36, which might contribute to the pathogenesis of diabetic macrovascular complications.

Animals↗
PubMed2004

Identification of the growth hormone-releasing peptide binding site in CD36: a photoaffinity cross-linking study.

The GHRPs (growth hormone-releasing peptides) are a class of small synthetic peptides known to stimulate GH release through binding of a G-protein-coupled receptor (designated GHS-R). We have found that hexarelin, a hexapeptide member of the GHRPs, binds to another protein identified as CD36, a scavenger receptor that is expressed in various tissues, including monocytes/macrophages and the endothelial microvasculature. CD36 is involved in the endocytosis of oxLDL (oxidized low-density lipoprotein) by macrophages, and in the modulation of angiogenesis elicited by thrombospondin-1 through binding to endothelial cells. To define the binding domain for hexarelin on CD36, covalent photolabelling of CD36 followed by enzymic and chemical degradation of the photoligand-receptor complex was performed. A 8 kDa photolabelled fragment corresponding to the CD36-(Asn132-Glu177) sequence has been identified as the hexarelin-binding site. Chemical cleavage of this fragment with CNBr resulted in the release of the free ligand, suggesting that Met169 is the contact point for the ligand within the receptor binding pocket. We conclude that the binding domain for hexarelin on CD36 overlaps with that for oxLDL, which corresponds to residues Gln155-Lys183 of CD36. Hence hexarelin might interfere with the CD36-mediated uptake of modified lipoproteins by macrophages. This may contribute, at least in part, to the anti-atherosclerotic effect of GHRPs in apolipoprotein E-deficient mice.

Amino Acid Sequence↗
PubMed1996

Inhibition of platelet adhesion to collagen by monoclonal anti-CD36 antibodies.

Monoclonal anti CD36 antibodies capable of inhibiting platelet adhesion to collagen have not previously been identified. We have now prepared two groups of monoclonal antibodies. One group was prepared using, as immunogen, highly purified (99+%) CD36 prepared by a denaturing procedure. These antibodies (Mo series) reacted strongly with CD36 on protein blots but did not immunoprecipitate native CD36 from platelet lysates nor inhibit platelet adhesion to collagen. The second group of monoclonal antibodies (131 series) was prepared using CD36 purified to >95% by a non-denaturing procedure. These antibodies reacted with control platelets, but not Nak(a)-negative platelets which lack CD36, as measured by flow cytometry and immunoprecipitation. Three monoclonal antibodies of this latter group (131.4, 131.5 and 131.7) inhibited platelet adhesion to collagen in static systems under Mg2+ -independent conditions but had lit tle effect in the presence of Mg2+. 131.4 and 131.7 also inhibited adhesion to collagen using citrated whole blood in a parallel plate flow chamber at physiological shear rates (800s-1), whereas 131.5 was without effect. These are the first anti-CD36 monoclonal antibodies shown to be capable of inhibiting platelet adhesion to collagen and provide further evidence that CD36 plays a role in platelet-collagen interaction.

Animals↗
PubMed2000

Apoptosis induced by oxidized low density lipoprotein in human monocyte-derived macrophages involves CD36 and activation of caspase-3.

Macrophage death may play a crucial role in the progression of atherosclerotic lesions. Here we present evidence that CD36 is involved in oxidized LDL (OxLDL)-induced apoptosis in human monocyte-derived macrophages. Anti-CD36 mAb SMO and OKM-5 reduced the number of apoptotic cells in OxLDL-treated macrophages by more than 94%, but they did not block ceramide-triggered apoptosis. Thrombospondin inhibited the induction of apoptosis by OxLDL in a dose-dependent manner with an IC50 of 10-30 microM. OxLDL did not induce apoptosis in CD36-negative macrophages, demonstrating the essential role of this scavenger receptor in OxLDL-triggered programmed cell death. Neither anti-CD36 Ig nor thrombospondin triggered programmed cell death suggesting that binding to CD36 alone is not sufficient to initiate apoptosis. However, inhibitors of OxLDL-induced apoptosis did not block the uptake of 3H-labeled OxLDL. In contrast, acetylated LDL and polyinosinic acid, ligands of scavenger receptor A (SRA), inhibited uptake of 3H-labeled OxLDL by 65 and 49%, respectively, but did not block OxLDL-induced apoptosis, indicating that SRA is not involved in this process. OxLDL also stimulated caspase-3 activity in human macrophages. Activation of caspase-3 was blocked by anti-CD36 Ig and the caspase-3 inhibitor Z-DEVD-FMK. These results suggest that binding of OxLDL to CD36 initiates a yet unknown OxLDL-specific signaling event, which leads to the rapid activation of caspase-3 resulting in apoptosis of human macrophages. Our data demonstrate a novel role for CD36 in macrophage biology with likely consequences for the development of atherosclerotic lesions.

Amino Acid Chloromethyl Ketones↗
PubMed1995

CD36 induction on human monocytes upon adhesion to tumor necrosis factor-activated endothelial cells.

Cell adhesion between circulating monocytes and the endothelium is a critical component of vascular thromboregulation and atherogenesis. The biochemical and genetic consequences of adhesion are poorly understood. We have found that monocyte surface expression of CD36, an integral membrane receptor for thrombospondin, collagen, and oxidized low density lipoprotein, increased dramatically upon adhesion to tumor necrosis factor-activated human umbilical vein endothelial cells (HUVEC). Expression was assessed by indirect immunofluorescence microscopy and immunoblotting using monoclonal antibodies to CD36. Steady-state CD36 mRNA levels, detected by RNase protection assay, also showed a similar pattern of up-regulation. To verify the adhesion dependence of the observed phenomenon, monocytes were co-cultured with tumor necrosis factor-activated HUVEC in a transwell apparatus that physically separated monocytes from the endothelial cells. Under these conditions, no increase in CD36 expression was detected, demonstrating that the enhanced monocyte CD36 expression observed is not due to soluble factors released by HUVEC. To characterize the specific adhesion molecules involved in the process, co-culture assays were performed on murine L cells transfected with either human E-selectin or intercellular adhesion molecule-1 cDNAs. A dramatic increase in CD36 mRNA was seen upon monocyte adhesion to E-selectin-transfected L cells compared with adhesion to intercellular adhesion molecule-1 or control transfectants. Furthermore, monoclonal antibodies to E-selectin inhibited the adhesion-dependent up-regulation of CD36 mRNA induced by transfected L cells or cytokine-activated endothelial cells. These findings demonstrate adhesion-dependent gene regulation of monocyte CD36 and suggest the possible involvement of E-selectin in initiating this process.

Adult↗
PubMed1995

Recombinant GST/CD36 fusion proteins define a thrombospondin binding domain. Evidence for a single calcium-dependent binding site on CD36.

CD36 is a multifunctional cell surface glycoprotein that acts as a surface receptor for thrombospondin (TSP), and thereby may mediate adhesive interactions between cells and substrata, platelets and other cells, and macrophages and apoptotic neutrophils. The identity of the TSP binding site on CD36 is controversial and may involve more than one structural domain. We have constructed a series of recombinant bacterial GST/CD36 fusion proteins that span nearly all of the CD36 molecule and have demonstrated that fusion proteins containing the region extending from amino acid 93 to 120 formed specific, saturable, and reversible complexes with TSP. As with intact CD36, binding was calcium-dependent, was independent of which ligand was immobilized, and was blocked by monoclonal antibodies to both CD36 and TSP. Stoichiometry and affinity of the fusion proteins for TSP were consistent with that of the intact protein. We also demonstrated that these fusion proteins competitively inhibited binding of TSP to purified platelet CD36 and to cell surface CD36 on peripheral blood monocytes and CD36 cDNA-transfected melanoma cells. These data demonstrate that the region between amino acids 93 and 120 has all of the characteristics required of the TSP binding domain.

Antigens, CD↗
PubMed1996

CD36 is palmitoylated on both N- and C-terminal cytoplasmic tails.

The membrane protein CD36 has been reported to carry out a wide range of potential functions, including serving as a receptor for thrombospondin, collagen, oxidized low density lipoprotein, fatty acids, anionic phospholipids, and Plasmodium falciparum malaria parasitized erythrocytes. This implicates CD36 in cellular adhesion, human atherosclerotic lesion formation, lipid metabolism, and malaria. A presumed rat homolog of CD36 was previously reported to be palmitoylated. We confirmed that human CD36 is palmitoylated and identified cysteines 3, 7, 464, and 466 as the palmitoylation sites using a mutagenesis approach. This result suggests that both the N- and C-terminal tails of CD36 are cytoplasmic. Published models for the topology of CD36 have the C terminus located in the cytoplasm but differ as to whether the N terminus is cytoplasmic or extracellular. To address this question, a C-terminal truncation mutant of CD36 was made by introducing a stop codon just upstream of the C-terminal transmembrane domain. This mutant was found membrane-bound when expressed in human embryonic kidney 293 cells, indicating that the N-terminal hydrophobic domain serves as a transmembrane anchor, and thus supporting a CD36 topology with two transmembrane domains.

Animals↗
PubMed1999

Phosphatidylserine receptors: role of CD36 in binding of anionic phospholipid vesicles to monocytic cells.

Exposure of phosphatidylserine (PtdSer) has been implicated in the recognition and phagocytosis of senescent and apoptotic cells, and CD36 has been proposed as one receptor protein that recognizes PtdSer and other anionic phospholipids. We investigated the binding of phospholipid vesicles to the monocytic leukemia cell lines THP-1 and J774A.1 with a flow cytometric assay; vesicles contained 50 mol% PtdSer, phosphatidylinositol (PtdIns), or phosphatidylglycerol (PtdGro), with the balance being phosphatidylcholine. Specific, high affinity binding was observed for vesicles containing PtdSer, PtdIns, or PtdGro. Specificity of the assay was confirmed by control experiments with erythrocytes, which showed minimal vesicle binding, and with annexin V, which blocked the binding of PtdSer, PtdGro, and PtdIns vesicles to the THP-1 cells. However, O-phospho-L-serine (to 1 mM) had no effect on the binding of PtdSer vesicles, indicating that high affinity binding requires a surface containing multiple phosphoserine groups rather than a single molecule. A monoclonal antibody to CD36 blocked up to 60% of the specific binding of PtdSer vesicles but had minimal to no effect on the binding of PtdGro or PtdIns vesicles. This antibody also selectively inhibited the phagocytosis of PtdSer-containing vesicles as measured by fluorescence microscopy, indicating that CD36 is functionally significant for phagocytosis of this vesicle type. In addition, collagen and thrombospondin, two other putative ligands of CD36, were unable to inhibit the binding of PtdSer vesicles. We conclude that CD36 is the primary protein responsible for the high affinity binding of PtdSer vesicles to these monocyte-like cells. In addition, CD36 appears to be specific for PtdSer among anionic phospholipids, and non-phospholipid ligands of CD36 do not share binding sites with PtdSer on CD36.

Annexin A5↗
PubMed2000

The binding of oxidized low density lipoprotein to mouse CD36 is mediated in part by oxidized phospholipids that are associated with both the lipid and protein moieties of the lipoprotein.

There is growing evidence that CD36 has an important physiological function in the uptake of oxidized low density lipoprotein (OxLDL) by macrophages. However, the ligand specificity and the nature of the ligands on OxLDL that mediate the binding to CD36 remain ill defined. Results from recent studies suggested that some of the macrophage scavenger receptors involved in the uptake of OxLDL recognized both the lipid and the protein moieties of OxLDL, but there was no conclusive direct evidence for this. The present studies were undertaken to test whether a single, well characterized OxLDL receptor, CD36, could bind both the lipid and protein moieties of OxLDL. COS-7 cells transiently transfected with mouse CD36 cDNA bound intact OxLDL with high affinity. This binding was very effectively inhibited ( approximately 50%) both by the reconstituted apoB from OxLDL and by microemulsions prepared from OxLDL lipids. The specific binding of both moieties to CD36 was further confirmed by direct ligand binding analysis and by demonstrating reciprocal inhibition, i.e. apoB from OxLDL inhibited the binding of the OxLDL lipids and vice versa. Furthermore, a monoclonal mouse antibody that recognizes oxidation-specific epitopes in OxLDL inhibited the binding of intact OxLDL and also that of its purified protein and lipid moieties to CD36. This antibody recognizes the phospholipid 1-palmitoyl 2-(5'-oxovaleroyl) phosphatidylcholine. This model of an oxidized phospholipid was also an effective competitor for the CD36 binding of both the resolubilized apoB and the lipid microemulsions from OxLDL. Our results demonstrate that oxidized phospholipids in the lipid phase or covalently attached to apoB serve as ligands for recognition by CD36 and, at least in part, mediate the high affinity binding of OxLDL to macrophages.

Animals↗
PubMed2006

A novel cell-permeable antioxidant peptide, SS31, attenuates ischemic brain injury by down-regulating CD36.

Oxidative stress is implicated in the pathogenesis of ischemia/reperfusion injury. Recently, we demonstrated that activation of CD36, a class B scavenger receptor, mediates free radical production and tissue injury in cerebral ischemia (1). Oxidized low density lipoproteins (oxLDL) are among the ligands that bind to CD36 and are elevated in acute cerebral infarction. SS31 is a cell-permeable antioxidant peptide that reduces intracellular free radicals and inhibits LDL oxidation/lipid peroxidation (2). The current study was designed to investigate whether treatment with SS31 normalizes ischemia-induced redox changes and attenuates CD36-mediated tissue injury. C57BL/6 mice were subjected to transient middle cerebral artery occlusion (MCAO). Redox status and infarct volume were measured in animals treated with either saline or SS31. Oxidative stress induced by ischemia/reperfusion profoundly depleted glutathione (GSH) concentrations in the ipsilateral cortex and striatum. Treating mice with SS31 immediately after reperfusion significantly attenuated ischemia-induced GSH depletion in the cortex and reduced infarct size. By contrast, the protective effect of SS31 was absent in CD36 knock-out mice, indicating that SS31 is acting through inhibition of CD36. Treating C57BL/6 mice with SS31 reduced CD36 expression in postischemic brain and mouse peritoneal macrophages (MPM). Further in vitro studies revealed that SS31 attenuated oxLDL-induced CD36 expression and foam cell formation in MPM. These in vivo and in vitro studies indicate that the down-regulation of CD36 by novel class antioxidant peptides may be a useful strategy to treat ischemic stroke victims.

Animals↗
PubMed2006

Novel immunoblotting monoclonal antibodies against human and rat CD36/fat used to identify an isoform of CD36 in rat muscle.

CD36, a surface membrane glycoprotein, functions as a class B scavenger receptor that binds to several distinct ligands. Included among these is oxidized low-density lipoprotein (Ox-LDL), a major trigger of atherosclerotic lesions, and the levels of CD36 activity and Ox-LDL uptake may have an impact on coronary artery disease. In addition, recent studies in rodents have shown that CD36, also known as FAT, controls the levels of free fatty acids and triglycerides in plasma, and is an important regulator of the metabolic pathways involved in insulin resistance. Despite the importance of measuring CD36 expression in different tissues there is a paucity of good immunoblotting antibodies, particularly for rodent tissue. Here, using GST-fusion proteins incorporating the cysteine cluster encoded by exons VIII, IX, and X of the CD36 gene as immunogen, we have generated a panel of monoclonal antibodies that are excellent blotting reagents for human and rat CD36. With these reagents we were able to visualize an additional, faster migrating CD36 band in rat muscle, likely representing a minor splice variant of CD36 (CD36var.1) hitherto seen only in the human HEL cell line.

Amino Acid Sequence↗
PubMed2002

Differential regulation of CD36 expression in antigen-presenting cells: Oct-2 dependence in B lymphocytes but not dendritic cells or macrophages.

In mice, three antigen-presenting cell types [B lymphocytes, macrophages and dendritic cells (DC)] express the scavenger receptor CD36. This molecule has been implicated in many important functions, including DC maturation and antigen presentation. In murine B cells, the CD36 gene requires the Oct-2 transcription factor for its expression. We previously found that B cells from Oct-2-null mice display defects in maturation, survival and proliferation. Here we have looked for a possible role for CD36 in B cells, but found that CD36 is dispensable for all responses tested. Although loss of CD36 did not directly affect B cell function, it did modulate slightly the isotype and level of IgG produced in vivo in naive mice, and IgM in Leishmania-infected mice. We also show that in DC and macrophages, CD36 expression is independent of Oct-2. We conclude that CD36 does not play a major role in B cell function, but that CD36 may contribute indirectly to humoral immunity through cells of the innate immune system.

Animals↗
PubMed2002

Role of CD36 in membrane transport of long-chain fatty acids.

CD36 is a multispecific membrane glycoprotein that has been postulated to have a variety of functions. Evidence generated in isolated cells and in mice and rat models of altered CD36 expression has indicated an important role for CD36 in membrane transport of long-chain fatty acids. The cumulative data indicate that CD36 facilitates a major fraction of fatty acid uptake by muscle and fat, and that CD36 deficiency is associated with a large (60-80%) defect in fatty acid uptake by those tissues. In humans, polymorphisms in the CD36 gene may underlie defective fatty acid metabolism and some forms of heart disease. Herein we review our current understanding of the transport function and regulation of CD36. The realization that the transport step rate limits cellular fatty acid utilization suggests that abnormalities in CD36 expression or function may impact on susceptibility to certain metabolic diseases such as obesity and insulin resistance.

Adipocytes↗
PubMed1995

Increased platelet CD36 constitutes a common marker in myeloproliferative disorders.

The distribution of the major platelet membrane glycoproteins (GP), Ib, IX, IIb-IIIa and IV (or CD36), which play important roles as receptors for adhesive molecules in haemostasis and thrombosis, was studied in 34 patients with myeloproliferative disorders (MPD): 13 had essential thrombocythaemia (ET), 12 had polycythaemia vera (PV) and nine had chronic myelogenous leukaemia (CML). Only occasionally were modifications of the numbers of GPIb or GPIIb-IIIa measured using the binding of specific radiolabelled antibodies to platelets. In contrast, 2-3-fold increases of the total CD36 content and the surface CD36 expression were measured in almost all patients studied, using a radioimmunoassay and the direct binding of the radiolabelled antibody, FA6-152, to the platelet surface, respectively. These results indicate that the abnormality affected both the external and internal CD36 pools. Therefore platelet CD36 may be a useful tool for the diagnosis and the follow-up of MPD patients. Surface CD36 has been proposed as a platelet receptor for thrombospondin, an adhesive glycoprotein that is released from platelets upon activation and promotes aggregate formation. Despite a 2-fold increase of CD36 molecules, resting and thrombin-activated platelets from ET patients expressed the same amount of thrombospondin as normal platelets, suggesting that there is not a direct correlation between the CD36 expression and thrombospondin binding either spontaneously or after activation.

Adult↗