CD36 is a membrane glycoprotein that is present on various types of cells, including monocytes, macrophages, microvascular endothelial cells, adipocytes and platelets. Macrophage CD36 participates in atherosclerotic arterial lesion formation through its interaction with oxidized low-density lipoprotein (oxLDL), which triggers signaling cascades for inflammatory responses. CD36 functions in oxLDL uptake and foam cell formation, which is the initial critical stage of atherosclerosis. In addition, oxLDL via CD36 inhibits macrophage migration, which may be a macrophage-trapping mechanism in atherosclerotic lesions. The role of CD36 was examined in in vitro studies and in vivo experiments, which investigated various functions of CD36 in atherosclerosis and revealed that CD36 deficiency reduces atherosclerotic lesion formation. Platelet CD36 also promotes atherosclerotic inflammatory processes and is involved in thrombus formation after atherosclerotic plaque rupture. Because CD36 is an essential component of atherosclerosis, defining the function of CD36 and its corresponding signaling pathway may lead to a new treatment strategy for atherosclerosis.
Animals ; Antigens, CD36/chemistry/genetics/*metabolism ; Atherosclerosis/*metabolism/pathology ; Humans ; Macrophages/metabolism/pathology ; Plaque, Atherosclerotic/*metabolism/pathology

OBJECTIVE: To analyze the molecular polymorphisms of CD36 among 58 blood donors with CD36 deficiency and compare with CD36 positive controls. METHODS: A total of 58 donors with CD36 deficiency during a screening conducted in the laboratory from September 2019 to December 2020 were enrolled as the test group, including 39 males and 19 females, while 120 platelet donors with CD36 positive were randomly selected as the controls, including 76 males and 44 females. All of the subjects were Han nationality. The PCR-SBT method was used to detect coding region of CD36 gene, and molecular mutations were compared with those CD36 positive controls. RESULTS: Among the 58 donors with CD36 deficiency, mutations appears in 32 individuals. The detection rate for type I was 71.43% (5/7), and type II was 51.92% (27/52), while among the 120 controls, mutations appears in 12 donors (10%). In the CD36 antigen-deficient donors, 16 variations were found, in which 329-330 del AC with the highest frequency accounted for 20.69%, followed by 1228-1239 del ATTGTGCCTATT(15.52%) and 1156 C>T(10.34%). Two variations, 198-205 del GATCTTTG and 220 C>T, led to premature termination of translation; four mutations, 329-330 del AC, 560 ins T, 1011-1049 39bp dupl and 1343-1344 ins TCTT, caused translation frame shift; 1228-1239 del ATTGTGCCTATT led to deletion of four amino acids (Ile-Val-Pro-Ile) at sites 410-413 of the peptide chain. The 1140 T>A and 1275 G>A were synonymous mutations, and the other 7 mutations resulted in the substitution of single nucleotide. The platelet expression in the donors of CD36 positive with 329-330 del AC or 1228-1239 del ATTGTGCCTATT mutation (heterozygote) was lower than those CD36 positive individuals without mutations (homozygote). CONCLUSION Multiple gene mutations in the CD36 coding region may cause CD36 deficiency, and the heterozygous individuals with mutations may lead to CD36 antigen reduction or deletion. Mutation is not detected in 44.83% of CD36 deficient individuals, there may be some other reasons for the CD36 antigen deficiency.
Blood Donors ; Blood Platelet Disorders/metabolism* ; Blood Platelets/metabolism* ; CD36 Antigens/metabolism* ; Female ; Genetic Diseases, Inborn ; Humans ; Male

OBJECTIVE: To investigate the effect of thrombospondin-1 (TSP-1) on apoptosis of human megakaryocytic leukemia cell line Meg-01 and its possible mechanism. METHODS: The expression of CD36 antigen in Meg-01 cells was detected by flow cytometry and immunocytochemistry. Meg-01 cells were cultured for 48 hours with TSP-1 and CD36 antibody FA6-152 at different concentrations. The early apoptosis and activity of caspase-3 were detected by flow cytometry. The effect of TSP-1 on the growth and differentiation of megakaryocytes was investigated by cell counting and CFU-MK culture. RESULTS: The flow cytometry and immunocytochemistry showed that CD36 antigen was expressed on the surface of Meg-01 cells. TSP-1 (5 μg/ml) inhibited the growth of Meg-01 cells, but had unobvious effect on M-07e cells. After addition of CD36 antibody FA6-152 (5, 10, and 25 μg/ml), the inhibition effect of TSP-1 was significantly reduced. TSP-1 (2.5, 5, and 7.5 μg/ml) increased the positive expression of Annexin V (P<0.01) and caspase-3 activity (P<0.01), which indicated that TSP-1 had a significant effect on inducing apoptosis. After addition of CD36 antibody FA6-152 (25 μg/ml), the apoptosis induced by TSP-1 in Meg-01 cells was significantly reduced. TSP-1 (5, 10, and 25 μg/ml) could significantly inhibit the formation of CFU-MK in mouse bone marrow cells, while β-TG could not. CD36 antibody FA6-152 (25 μg/ml) could significantly reduce the inhibition of TSP-1 on CFU-MK. CONCLUSION TSP-1 may induce apoptosis of megakaryocytic leukemia cell line Meg-01 cells via CD36/caspase-3, which provides a potential new drug development and treatment target for clinical treatment of megakaryocytic leukemia.
Animals ; Apoptosis ; CD36 Antigens/metabolism* ; Caspase 3/metabolism* ; Cell Line ; Humans ; Leukemia, Megakaryoblastic, Acute ; Mice ; Thrombospondin 1/pharmacology*

The individual with the deficiency of CD36 antigen on platelet displayed the risk of anti-CD36 immune reaction induced by transfusion, which is one of the reasons for platelet transfusion refractoriness (PTR). This study was purposed to detect the expression level of CD36 antigen on platelet by flow cytometry among apheresis platelet donors of Hangzhou area, and the frequency of CD36 deficiency was analyzed. Platelet-rich plasma (PRP) was separated from fresh anticoagulant whole blood by centrifugation, then the platelets were washed and adjusted to 1×10(6). The platelets were incubated with FITC-labeled CD36 and PE-labeled CD41 monoclonal antibodies, then the expression level of CD36 was detected by flow cytometry. The CD36 expression on monocytes for the samples of CD36-deficiency on the platelets was further analyzed. The results showed that 7 samples with CD36 antigen deficiency were found in 192 apheresis platelet donors. The frequency of CD36 deficiency was 3.6% and all of them were typeII deficiency. The significant difference of CD36 antigen expression was observed in the platelet donors of Hangzhou population, among them 59 individuals with low expressed CD36 antigen and 126 individuals with highly expressed CD36 antigen were found according to the geometric mean fluorescence intensity. It is concluded that the CD36 antigen deficient phenotype existed in the population, these data will provide the information for research of the CD36 antigen distribution and help to solve the platelet transfusion refractoriness.
Blood Platelet Disorders ; diagnosis ; Blood Platelets ; metabolism ; CD36 Antigens ; metabolism ; Flow Cytometry ; methods ; Genetic Diseases, Inborn ; diagnosis ; Humans

Cardio-cerebral vascular disease induced by atherosclerosis is a serious cause of human health. The pathogenesis of AS is very complex,and the oxidized low-density lipoprotein( ox LDL) induced foam cells formation is considered to be the most important cytological change in AS. Based on the definition of " TCM chemical biology",we clarified the chemical composition of Ilex hainanensis,the effective substances of I. hainanensis on the activity of anti-AS were screened. Then we found that saponin BF523 had the good inhibitory effect on foam cell formation. In this research,we studied the BF523 as the research object to clarify the molecular target of the active compound of I. hainanensis by foam cell formation model. The results showed that BF523 significantly inhibited the oxidation of ox LDL-induced macrophage foaming and decreased the lipid content in macrophages. BF523 had inhibited the phagocytosis of ox LDL in macrophages by reducing the mRNA and protein levels of scavenger receptor CD36,thereby inhibiting the occurrence and development of AS. These findings not only clarified the mechanism of the inhibition of foam cell formation by saponin BF523,but also provided a useful exploration for the enrichment of the theory of " TCM chemical biology".
Atherosclerosis ; CD36 Antigens ; metabolism ; Cells, Cultured ; Foam Cells ; cytology ; drug effects ; Humans ; Ilex ; chemistry ; Lipoproteins, LDL ; adverse effects

BACKGROUND: Scavenger receptors are thought to be involved in the recognition of oxidized low-density lipoprotein (oxLDL) and oxidized erythrocyte (oxRBC). However, there are controversies about the kind of receptors and ligands related to the binding. Macrophages lacking class A scavenger receptor show identical binding of oxRBC with wild-type ones. METHODS: RBCs were oxidized with ascorbic acid and CuSO4. Lipid oxidation was measured indirectly by measuring TBARS semiquantitatively. The binding and phagocytosis were measured by counting the number of oxRBC bound or taken up after incubation at 4 degrees C or 37 degrees C for 60 minutes to 100 macrophages differentiated from human monocytic leukemia cell line. RESULTS: The degree of oxidation and the binding of oxRBCs were dependent on the concentration of CuSO4. The binding and phagocytosis of oxRBC were inhibited by 99% with oxLDL. Fucoidan, competing class A scavenger receptor, inhibited the binding by more than 90%. The binding of oxRBC was higher at 37 degrees C than at 4 degrees C by 3 times. The binding of oxRBCs was maximal at pH 6.5 and higher than at physiologic pH by 2.8 times. At pH 8.5 and 9.5, binding decreased by 67 and 88%, respectively. CONCLUSION: OxRBCs might bind and be taken up to macrophages not mainly through class A nor B scavenger receptors, but through other scavenger receptors and/or pathways. These processes are dynamic and ionic strength might be involved.
Antigens, CD36 ; *Erythrocyte Aging ; Erythrocytes/*metabolism ; Human ; Lipoproteins, LDL/metabolism ; Macrophages/*metabolism ; Oxidation-Reduction ; Phagocytosis/*physiology ; Receptors, Immunologic/metabolism ; Support, Non-U.S. Gov't ; Tumor Cells, Cultured/metabolism

OBJECTIVETo investigate the anti-atherosclerosis mechanism of Astragalus mongholicus polysaccharides (APS) by examining its effect on gene expression profiles of the dendritic cells (DCs) from healthy donors.

METHODSPeripheral blood DCs from healthy donors were incubated with 200 mg/L APS overnight, and changes in the gene expression profiles were investigated using microarray technique and RT-PCR.

RESULTSCompared with the control cells, APS-treated DCs showed significantly up-regulated expressions of CD36 (0.97 ± 0.23 vs 5.45 ± 1.14) and IL-27 (1.08 ± 0.22 vs 2.97 ± 0.61) and down-regulated expression of expression of IFI16 (0.98 ± 0.18 vs 0.46 ± 0.11).

CONCLUSIONSAPS can promote the maturation and differentiation of DCs by up-regulating CD36 and IL-27 and down-regulating IFI16, and thus positively affects the occurrence and progression of the atherosclerosis.

Astragalus Plant ; chemistry ; CD36 Antigens ; metabolism ; Cell Differentiation ; Dendritic Cells ; drug effects ; Humans ; Interleukins ; metabolism ; Nuclear Proteins ; metabolism ; Phosphoproteins ; metabolism ; Polysaccharides ; pharmacology ; Transcriptome

Adolescent ; Adult ; CD36 Antigens ; blood ; Diagnosis, Differential ; Female ; Humans ; Male ; Medicine, Chinese Traditional ; Middle Aged ; Platelet Activation ; Psoriasis ; blood ; diagnosis ; Thrombin ; metabolism ; Thrombospondins ; blood

The development of nonalcoholic fatty liver disease (NAFLD) is closely related to the fatty acid (FA) uptake. This study aimed to investigate the effect of Krüppel-like factor 9 (KLF9) on CD36 (typical fatty acid translocase), hepatocellular lipid metabolism as well as the development and progression of nonalcoholic fatty liver. High-fat diet-induced obese C57BL/6J mice and db/db mice were used to test the expression levels of Klf9 and Cd36 in the livers. The primary hepatocytes were isolated from C57BL/6J mice, treated with Ad-GFP, Ad-Klf9, Ad-shCtrl or Ad-shKlf9, and then incubated with oleic acid and palmitic acid for 24 h. Liver-specific knockout of Klf9 mice were established. The protein levels and relative mRNA levels were examined by Western blot and real-time PCR, respectively. Triglyceride content was determined by using an assay kit. Lipid content was determined by Oil Red O staining. The results showed that: (1) Klf9 expression levels were increased in the livers of high-fat diet-induced obese mice and db/db mice, compared to their respective control mice. (2) Adenovirus-mediated overexpression of Klf9 in primary hepatocytes increased Cd36 expression and cellular triglyceride contents. (3) In contrast, adenovirus-mediated knockdown of Klf9 expression in primary hepatocytes by Ad-shKlf9 decreased Cd36 expression and cellular triglyceride contents. (4) Finally, Klf9 deficiency decreased liver Cd36 expression and alleviated fatty liver phenotype of high-fat diet-induced obese mice. These results suggest that KLF9 can regulate hepatic lipid metabolism and development of NAFLD by promoting the expression of CD36.
Animals ; CD36 Antigens/metabolism* ; Diet, High-Fat ; Kruppel-Like Transcription Factors/metabolism* ; Lipid Metabolism ; Liver ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Non-alcoholic Fatty Liver Disease/metabolism* ; Oleic Acid/metabolism*

OBJECTIVETo observe the effect of Nur77 on lipid loading in macrophages exposed to 40 microg/ml oxidized low density lipoprotein (ox-LDL).

METHODSStable RAW264.7 strain expressing green fluorescent protein (GFP) or GFP-Nur77 was established by G418 screening after transfection with corresponding plasmids and identified by Western blot. After 24 h stimulation with ox-LDL, intracellular lipid loading of each strain was observed by Oil Red O dyeing, and the intracellular cholesterol level was measured by liquid chromatographic-mass spectrometry (LC-MS). The transcriptional changes of CD36 and ABCA1 were monitored by Real Time Quantitative-PCR, while the expressions of these two proteins were assayed by flow cytometry and Western blot, respectively.

RESULTSAfter 24 h stimulation with ox-LDL, intracellular total cholesterol and esterified cholesterol concentration in GFP-Nur77-RAW264.7 were significantly dropped by 26.15% and 30.93% respectively (P < 0.05 vs. GFP-RAW264.7). The transcription and expression of ABCA1 in GFP-Nur77-RAW264.7 were significantly increased while the transcription and expression of CD36 were significantly reduced (all P < 0.05 vs. GFP-RAW264.7).

CONCLUSIONOrphan nuclear receptor Nur77 reduced ox-LDL induced intracellular lipid loading in macrophages by inhibiting lipid influx and enhancing lipid efflux.

Animals ; CD36 Antigens ; metabolism ; Cell Line ; Cholesterol ; metabolism ; DNA, Complementary ; DNA-Binding Proteins ; genetics ; Lipid Metabolism ; Lipoproteins, LDL ; metabolism ; Macrophages ; metabolism ; Mice ; Nuclear Receptor Subfamily 4, Group A, Member 1 ; Receptors, Steroid ; genetics ; Transfection