Lack of apoE causes alteration of cytokines expression in young mice liver. Mol Biol Rep. 2010;37:2049-2054. [PMID: 19644765 DOI: 10.1007/s11033-009-9660-x]

Renal and Peripheral Blood Transcriptome Signatures That Predict Treatment Response in Proliferative Lupus Nephritis-A Prospective Study

Mechanisms contributing to non-response to treatment in lupus nephritis (LN) are unclear. We characterised the transcriptome of paired peripheral blood mononuclear cells (PBMCs) and renal tissues in LN before and after cyclophosphamide (CYC) treatment and identified markers that predicted treatment response. Total RNA isolated from paired PBMCs (n = 32) and renal tissues (n = 25) of 16 proliferative LN before CYC treatment, 6 months post-treatment, and during renal flare, was sequenced on Illumina Novaseq-6000 platform. Post-treatment, eight patients were clinical responders (CR), of whom four flared (FL), and eight were non-responders (NR). Comparative transcriptomic analyses before and after treatment within CR, NR, and FL groups was performed using DESeq2. Weighted gene co-expression network analysis (WGCNA) and ROC analysis was performed to identify and validate hub genes predictive of treatment response. Based on this, we observed that pathways such as degradation of cell cycle proteins, expression of G0 and G1 phase proteins, and apoptosis, were upregulated in CR PBMCs post-treatment, while IFN-γ signalling and ECM organisation were downregulated. In NR PBMCs, ECM molecules, neddylation and BCR signalling were upregulated post-CYC treatment, while in NR renal tissue, TLR, IFN and NF-κB signalling pathways were upregulated. In FL PBMCs, neutrophil degranulation and ROS and RNS production in phagocytes were downregulated following treatment, whereas, in the corresponding renal tissue, cell-ECM interactions and ISG15 antiviral mechanism were downregulated. After WGCNA and subsequent ROC analysis, TENM2, NLGN1 and AP005230.1 from PBMCs each predicted NR (AUC-0.91; p = 0.03), while combined model improved prediction (AUC-0.94; p = 0.02). AP005230.1 from renal tissue also predicted non-response (AUC-0.94; p = 0.01) and AC092436.3 from PBMCs predicted renal flare (AUC-0.81; p = 0.04). Our study identified significant DEGs/pathways specific to different treatment outcomes and hub genes that predicted non-response and renal flare.

APOE Drives Glioma Progression by Modulating CCL5/CCR5 Signaling in the Tumor Microenvironment and Inducing M2 Macrophage Polarization

BACKGROUND

Tumor-associated macrophages (TAMs) are pivotal in shaping the tumor microenvironment (TME) during cancer progression. Emerging evidence indicates that dysregulation of key signaling pathways in cancer cells drives the secretion of various cytokines, modulating TAMs function. This study aimed to explore how glioblastoma cells regulate macrophages and establish a TME conducive to tumor immune escape.

METHODS

In previous bioinformatics studies, we identified abnormally expressed genes in glioblastoma patients. Among them, the metabolism-related protein APOE garnered particular attention. We generated U87 and U251 cell lines with altered APOE expression to evaluate cancer cell invasion, migration, and inflammatory cytokine secretion through scratch assays, Transwell assays, and ELISA, respectively. Additionally, we established a co-culture system of cancer cells and monocytes THP-1 to assess the impact of shAPOE tumor cells on macrophage polarization using flow cytometry, Western blot, and immunofluorescence techniques.

RESULT

Knockdown of APOE significantly reduced the viability, invasion, and migration capabilities of U87 and U251 cells. ELISA results also showed that APOE knockdown cells secreted higher levels of IL-6, IL-12, and TNF-α, while CCL5 and TGF-β secretion was markedly reduced. In macrophage studies, we observed that APOE knockdown altered the M1/M2 polarization ratio in THP-1 monocytes, with CCR5 inhibition further decreasing M2 macrophage proportions. Immunofluorescence analysis revealed that the reduction of M2 macrophages was dependent on APOE and CCL5.

CONCLUSION

Our findings indicate that APOE knockdown suppresses glioblastoma cell migration, invasion, and CCL5 secretion, while enhancing the production of tumor-suppressive cytokines.

Central regulation of stress-evoked peripheral immune responses

Stress-linked psychiatric disorders, including anxiety and major depressive disorder, are associated with systemic inflammation. Recent studies have reported stress-induced alterations in haematopoiesis that result in monocytosis, neutrophilia, lymphocytopenia and, consequently, in the upregulation of pro-inflammatory processes in immunologically relevant peripheral tissues. There is now evidence that this peripheral inflammation contributes to the development of psychiatric symptoms as well as to common co-morbidities of psychiatric disorders such as metabolic syndrome and immunosuppression. Here, we review the specific brain and spinal regions, and the neuronal populations within them, that respond to stress and transmit signals to peripheral tissues via the autonomic nervous system or neuroendocrine pathways to influence immunological function. We comprehensively summarize studies that have employed retrograde tracing to define neurocircuits linking the brain to the bone marrow, spleen, gut, adipose tissue and liver. Moreover, we highlight studies that have used chemogenetic or optogenetic manipulation or intracerebroventricular administration of peptide hormones to control somatic immune responses. Collectively, this growing body of literature illustrates potential mechanisms through which stress signals are conveyed from the CNS to immune cells to regulate stress-relevant behaviours and comorbid pathophysiology.

Inhibition of Lung Tumor Development in ApoE Knockout Mice via Enhancement of TREM-1 Dependent NK Cell Cytotoxicity

Apolipoprotein E (ApoE) is known to regulate lipid homeostasis and associated with atherosclerogenesis. Eventhough atherosclerogenesis is associated with tumor development, the role of ApoE in lung tumorigenesis and metastasis is not clear. Thus, the tumor growth and metastasis were compared in WT and ApoE knockout (KO) mice. Urethane-induced lung tumor incidence and B16F10 lung metastasis in ApoE knockout (KO) mice were significantly reduced in comparison to that in WT mice. Knockdown of ApoE expression in lung cancer cells and B16F10 cells also decreased cancer cell growth and metastasis. The inhibitory effect of ApoE KO on tumor development and metastasis was associated with increase of infiltration of NK cells. NK cells derived from ApoE KO mice showed much greater cytotoxicity than those from WT mice. These cytotoxic effect of NK cells derived from ApoE KO mice was associated with higher expression of Granzyme B, Fas Ligand, IFN-γ, TNF-α, NKG2D, NKp46, and DNAM-1 expression. Triggering receptor expressed on myeloid cell (TREM)-1 is a proinflammatory mediator expressed on NK cells, and is known to be associated with NK cell cytotoxicity. Thus, we investigated the role of TREM-1 on ApoE KO mice originated NK cell mediated cytotoxicity for cancer cells. Blockade of TREM-1 expression with a TREM-1 antagonist prevented NK cell-mediated cytotoxicity. TREM-1 antibody recovered cytotoxic effect of NK cells derived from KO mice of T-bet, which upregulating gene for TREM-1. These data indicate that ApoE KO suppressed lung tumor development and metastasis via increase of TREM-1-dependent anti-tumor activity of NK cells.

Lactobacillus plantarum BSGP201683 Isolated from Giant Panda Feces Attenuated Inflammation and Improved Gut Microflora in Mice Challenged with Enterotoxigenic Escherichia coli

In this work, we searched for an effective probiotic that can help control intestinal infection, particularly enterotoxigenic Escherichia coli K88 (ETEC) invasion, in giant panda (Ailuropoda melanoleuca). As a potential probiotic strain, Lactobacillus plantarum BSGP201683 (L. plantarum G83) was isolated from the feces of giant panda and proven beneficial in vitro. This study was aimed to evaluate the protective effect of L. plantarum G83 in mice challenged with ETEC. The mice were orally administered with 0.2 mL of PBS containing L. plantarum G83 at 0 colony-forming units (cfu) mL⁻¹ (control; negative control, ETEC group), 5.0 × 10⁸ cfu mL⁻¹ (LDLP), 5.0 × 10⁹ cfu mL⁻¹ (MDLP), and 5.0 × 10¹⁰ cfu mL⁻¹ (HDLP) for 14 consecutive days. At day 15, the mice (LDLP, MDLP, HDLP, and ETEC groups) were challenged with ETEC and assessed at 0, 24, and 144 h. Animal health status; chemical and biological intestinal barriers; and body weight were measured. Results showed that L. plantarum G83 supplementation protected the mouse gut mainly by attenuating inflammation and improving the gut microflora. Most indices significantly changed at 24 h after challenge compared to those at 0 and 144 h. All treatment groups showed inhibited plasma diamine oxidase activity and _D-lactate concentration. Tight-junction protein expression was down-regulated, and interleukin (IL)-1β, IL-6, IL-8, TLR4, and MyD88 levels were up-regulated in the jejunum in the LDLP and MDLP groups. The number of the Enterobacteriaceae family and the heat-labile enterotoxin (LT) gene decreased (P < 0.05) in the colons in the LDLP and MDLP groups. All data indicated that L. plantarum G83 could attenuate acute intestinal inflammation caused by ETEC infection, and the low and intermediate doses were superior to the high dose. These findings suggested that L. plantarum G83 may serve as a protective probiotic for intestinal disease and merits further investigation.

Apolipoprotein E Gene Polymorphisms in Saudi Patients with Systemic Lupus Erythematosus

Apolipoprotein E (APOE) is a glycosylated protein with multiple biological properties. APOE gene polymorphism plays a central role in lipid metabolism and has recently been suggested to regulate inflammation. Our objective is to evaluate whether APOE polymorphism affects susceptibility to SLE. APOE genotyping was performed using ApoE StripAssay™ kit. Results indicated significantly higher frequencies of allele ε4 and genotype ε3/ε4 and lower frequencies of allele ε3 and genotype ε3/ε3 in SLE patients than controls. APOE ε2 allele was found in three patients, whereas it was absent in controls. The frequencies of allele ε4 and genotype ε3/ε4 were significantly higher in SLE patients with renal involvement and those of alleles ε2, ε4 and genotypes ε2/ε3, ε3/ε4 were higher in patients with neuropsychiatric symptoms. It is concluded that APOE allele ε4 is associated with susceptibility risk/clinical manifestations of SLE and ε2 may increase its severity while ε3 is protective for SLE in Saudis.

The binding capability of plasma phospholipid transfer protein, but not HDL pool size, is critical to repress LPS induced inflammation

Phospholipid transfer protein (PLTP) participates in high density lipoprotein (HDL) metabolism. Increased plasma PLTP activity was observed in lipopolysaccharide (LPS) triggered acute inflammatory diseases. This study aimed to determine the exact role of PLTP in LPS induced inflammation. HDL pool size was shrunk both in PLTP deficient mice (PLTP−/−) and PLTP transgenic mice (PLTP-Tg). PLTP displayed a strong protective effect on lethal endotoxemia in mice survival study. Furthermore, after LPS stimulation, the expression of pro-inflammatory cytokines were increased in bone marrow derived macrophage (BMDM) from PLTP−/−, while decreased in BMDM from PLTP-Tg compared with BMDM from wild-type mice (WT). Moreover, LPS induced nuclear factor kappa-B (NFκB) activation was enhanced in PLTP−/− BMDM or PLTP knockdown RAW264.7. Conversely, PLTP overexpression countered the NFκB activation in LPS challenged BMDM. Additionally, the activation of toll like receptor 4 (TLR4) induced by LPS showed no alteration in PLTP−/− BMDM. Finally, PLTP could bind to LPS, attenuate the pro-inflammatory effects of LPS, and improve the cell viability in vitro. To sum up, these findings elucidated that PLTP repressed LPS induced inflammation due to extracellular LPS binding capability, and the protective effects were not related to HDL pool size in mice.

Hyperlipidemia Alters Regulatory T Cell Function and Promotes Resistance to Tolerance Induction Through Costimulatory Molecule Blockade

Recent work from our laboratory has shown that hyperlipidemia promotes accelerated rejection of vascularized cardiac allografts in mice by inducing anti-donor Th17 reactivity and production of IL-17. Here, we show that hyperlipidemia also affects FoxP3(+) regulatory T cells (Tregs). Hyperlipidemia promotes the development of Tregs that express low levels of CD25. Hyperlipidemia also promotes a decrease in central Tregs and an increase in effector Tregs that appears to account for the increase in the frequency of CD25(low) Tregs. Alterations in Treg subsets also appear to lead to alterations in Treg function. The ability of FoxP3(+) , CD25(high) , CD4(+) Tregs from hyperlipidemic mice to inhibit proliferation of effector T cells stimulated with anti-CD3 and CD28 was reduced when compared with Tregs from control mice. Regulatory T cells isolated from hyperlipidemic recipients exhibit increased activation of Akt, and a reduction in Bim levels that permits the expansion of FoxP3(+) CD25(low) CD4(+) T cells. Hyperlipidemic mice were also resistant to tolerance induction using costimulatory molecule blockade consisting of anti-CD154 and CTLA4Ig, a strategy that requires Tregs. Together, our data suggest that hyperlipidemia profoundly affects Treg subsets and function as well as the ability to induce tolerance.

Hypothermia stimulates glioma stem spheres to spontaneously dedifferentiate adjacent non-stem glioma cells

Current models of stem cell biology assume that glioma stem cells reside at the apices of hierarchies and differentiate into non-stem progeny in a unidirectional manner. However, here we found an opposite phenomenon that glioma stem spheres could induce adjacent non-stem glioma cells to spontaneously dedifferentiate into stem-like cells in low temperature condition. In low temperature condition, it has been reported that mild hypothermia could induce pluripotent stem cells in hESC and iPSC. However, till now, its effects on glioma stem cells were still unknown. In this study, tracking the non-stem cells, we found that they could be attracted by stem spheres, and finally enter the stem spheres to become a member of stem spheres in vitro. However, these induced stem-like cells positive of CD133 and Nestin markers could not form an obvious sphere. To better understand the genetic differences of the stem spheres and stem-like cells underlying the change of microenvironment, we carried out Cytokine antibody array, Cancer PathwayFinder PCR array, and miRNA chip array, which demonstrated that lots of cytokines, mRNAs, and miRNAs involved in this microenvironmental change. In this study, the most important discovery by us was that we found GSCs sphere cores, which has been found to have strong proliferative capacity, and be able to 100 % form a big GSCs sphere. We hope these findings can change our past concepts, and be help to the further research on gliomas stem cells, and GSCs sphere cores can be defined as the primitive stem cells for further research.

Genetic association of apolipoprotein E polymorphisms with inflammatory bowel disease

AIM: To study the association of apolipoprotein E (APOE) polymorphisms with the susceptibility of inflammatory bowel disease (IBD) in Saudi patients.

METHODS: APOE genotyping was performed to evaluate the allele and genotype frequencies in 378 Saudi subjects including IBD patients with ulcerative colitis (n = 84) or Crohn’s disease (n = 94) and matched controls (n = 200) using polymerase chain reaction and reverse-hybridization techniques.

RESULTS: The frequencies of the APOE ε2 allele and ε2/ε3 and ε2/ε4 genotypes were significantly higher in IBD patients than in controls (P < 0.05), suggesting that the ε2 allele and its heterozygous genotypes may increase the susceptibility to IBD. On the contrary, the frequencies of the ε3 allele and ε3/ε3 genotype were lower in IBD patients as compared to controls, suggesting a protective effect of APOE ε3 for IBD. The prevalence of the ε4 allele was also higher in the patient group compared to controls, suggesting that the ε4 allele may also increase the risk of IBD. Our results also indicated that the APOE ε4 allele was associated with an early age of IBD onset. No effect of gender or type of IBD (familial or sporadic) on the frequency distribution of APOE alleles and genotypes was noticed in this study.

CONCLUSION: APOE polymorphism is associated with risk of developing IBD and early age of onset in Saudi patients, though further studies with a large-size population are warranted.

H1-antihistamines exacerbate high-fat diet-induced hepatic steatosis in wild-type but not in apolipoprotein E knockout mice

We examined the effects of two over-the-counter H1-antihistamines on the progression of fatty liver disease in male C57Bl/6 wild-type and apolipoprotein E (ApoE)-/- mice. Mice were fed a high-fat diet (HFD) for 3 mo, together with administration of either cetirizine (4 mg/kg body wt) or fexofenadine (40 mg/kg body wt) in drinking water. Antihistamine treatments increased body weight gain, gonadal fat deposition, liver weight, and hepatic steatosis in wild-type mice but not in ApoE-/- mice. Lobular inflammation, acute inflammation, and necrosis were not affected by H1-antihistamines in either genotype. Serum biomarkers of liver injury tended to increase in antihistamine-treated wild-type mice. Serum level of glucose was increased by fexofenadine, whereas lipase was increased by cetirizine. H1-antihistamines reduced the mRNA expression of ApoE and carbohydrate response element-binding protein in wild-type mice, without altering the mRNA expression of sterol regulatory element-binding protein 1c, fatty acid synthase, or ApoB100, in either genotype. Fexofenadine increased both triglycerides and cholesterol ester, whereas cetirizine increased only cholesterol ester in liver, with a concomitant decrease in serum triglycerides by both antihistamines in wild-type mice. Antihistamines increased hepatic levels of conjugated bile acids in wild-type mice, with the effect being significant in fexofenadine-treated animals. The increase was associated with changes in the expression of organic anion transport polypeptide 1b2 and bile salt export pump. These results suggest that H1-antihistamines increase the progression of fatty liver disease in wild-type mice, and there seems to be an association between the severity of disease, presence of ApoE, and increase in hepatic bile acid levels.

The positive correlations of apolipoprotein E with disease activity and related cytokines in systemic lupus erythematosus

BACKGROUND

The aim of this study is to investigate the expression of apolipoprotein E (apoE) and the relationship between apoE and disease activity of SLE, and the possible effects of glucocorticoid on apoE and other cytokines activities in SLE patients.

METHODS

Forty treatment-naïve SLE patients and forty matched healthy controls were studied. All the SLE patients received prednisone 1 mg/kg/day for 28 consecutive days. The sera levels of apoE and related cytokines were evaluated by ELISA. The expression of apoE mRNA in peripheral blood mononuclear cells (PBMCs) was determined by real-time PCR.

RESULTS

Compared with healthy controls, the relative expression levels of ApoE proteins and sera levels were significantly up-regulated in active SLE patients. ApoE sera concentrations positively correlated with SLEDAI, anti-dsDNA antibody and the related cytokines including IL-6, IFN-γ and IL-10, and uncorrelated with the concentration of total cholesterol (TC) and triglyceride (TG) in SLE patients. After 4 weeks prednisone treatment, the relative mRNA expression of apoE and the serum levels of apoE and related cytokines decreased.

CONCLUSIONS

ApoE correlated with disease activity and related cytokines in SLE patients. Glucocorticoid can down-regulate the expressions of apoE and related cytokines.

VIRTUAL SLIDE

The virtual slide(s) for this article can be found here:http://www.diagnosticpathology.diagnomx.eu/vs/1646714011077325.

Proteome changes in auricular lymph nodes and serum after dermal sensitization to toluene diisocyanate in mice

Some reactive chemicals, such as diisocyanates, are capable of initiating an allergic response, which can lead to occupational asthma after a latency period. Clinical symptoms such as cough, wheezing, and dyspnea occur only late, making it difficult to intervene at an early stage. So far, most studies using proteomics in lung research have focused on comparisons of healthy versus diseased subjects. Here, using 2D-DIGE, we explored proteome changes in the local draining lymph nodes and serum of mice dermally sensitized once or twice with toluene-2,4-diisocyanate (TDI) before asthma is induced. In the lymph nodes, we found 38 and 58 differentially expressed proteins after one and two treatments, respectively, between TDI-treated and vehicle-treated mice. In serum, seven and 16 differentially expressed proteins were detected after one and two treatments, respectively. We identified 80-85% of the differentially expressed proteins by MS. Among them, lymphocyte-specific protein-1, coronin 1a, and hemopexin were verified by Western blotting or ELISA in an independent group of mice. This study revealed alterations in the proteomes early during sensitization in a mouse model before the onset of chemical-induced asthma. If validated in humans, these changes could lead to earlier diagnosis of TDI-exposed workers.

Nanobodies targeting mouse/human VCAM1 for the nuclear imaging of atherosclerotic lesions

RATIONALE

A noninvasive tool allowing the detection of vulnerable atherosclerotic plaques is highly needed. By combining nanomolar affinities and fast blood clearance, nanobodies represent potential radiotracers for cardiovascular molecular imaging. Vascular cell adhesion molecule-1 (VCAM1) constitutes a relevant target for molecular imaging of atherosclerotic lesions.

OBJECTIVE

We aimed to generate, radiolabel, and evaluate anti-VCAM1 nanobodies for noninvasive detection of atherosclerotic lesions.

METHODS AND RESULTS

Ten anti-VCAM1 nanobodies were generated, radiolabeled with technetium-99m, and screened in vitro on mouse and human recombinant VCAM1 proteins and endothelial cells and in vivo in apolipoprotein E-deficient (ApoE(-/-)) mice. A nontargeting control nanobody was used in all experiments to demonstrate specificity. All nanobodies displayed nanomolar affinities for murine VCAM1. Flow cytometry analyses using human human umbilical vein endothelial cells indicated murine and human VCAM1 cross-reactivity for 6 of 10 nanobodies. The lead compound cAbVCAM1-5 was cross-reactive for human VCAM1 and exhibited high lesion-to-control (4.95±0.85), lesion-to-heart (8.30±1.11), and lesion-to-blood ratios (4.32±0.48) (P<0.05 versus control C57Bl/6J mice). Aortic arch atherosclerotic lesions of ApoE(-/-) mice were successfully identified by single-photon emission computed tomography imaging. (99m)Tc-cAbVCAM1-5 binding specificity was demonstrated by in vivo competition experiments. Autoradiography and immunohistochemistry further confirmed cAbVCAM1-5 uptake in VCAM1-positive lesions.

CONCLUSIONS

The (99m)Tc-labeled, anti-VCAM1 nanobody cAbVCAM1-5 allowed noninvasive detection of VCAM1 expression and displayed mouse and human cross-reactivity. Therefore, this study demonstrates the potential of nanobodies as a new class of radiotracers for cardiovascular applications. The nanobody technology might evolve into an important research tool for targeted imaging of atherosclerotic lesions and has the potential for fast clinical translation.

Genetics of late-onset Alzheimer's disease: update from the alzgene database and analysis of shared pathways

The genetics of late-onset Alzheimer's disease (LOAD) has taken impressive steps forwards in the last few years. To date, more than six-hundred genes have been linked to the disorder. However, only a minority of them are supported by a sufficient level of evidence. This review focused on such genes and analyzed shared biological pathways. Genetic markers were selected from a web-based collection (Alzgene). For each SNP in the database, it was possible to perform a meta-analysis. The quality of studies was assessed using criteria such as size of research samples, heterogeneity across studies, and protection from publication bias. This produced a list of 15 top-rated genes: APOE, CLU, PICALM, EXOC3L2, BIN1, CR1, SORL1, TNK1, IL8, LDLR, CST3, CHRNB2, SORCS1, TNF, and CCR2. A systematic analysis of gene ontology terms associated with each marker showed that most genes were implicated in cholesterol metabolism, intracellular transport of beta-amyloid precursor, and autophagy of damaged organelles. Moreover, the impact of these genes on complement cascade and cytokine production highlights the role of inflammatory response in AD pathogenesis. Gene-gene and gene-environment interactions are prominent issues in AD genetics, but they are not specifically featured in the Alzgene database.

Cross-talk between apolipoprotein E and cytokines

Apolipoprotein E (apoE) is a multifunctional glycosylated protein characterized by its wide tissue distribution. Despite its importance in lipid transport and atherosclerosis pathogenesis, apoE is associated with neurodegenerative disorders such as Alzheimer's disease (AD) and Parkinson disease, and autoimmune disorders such as multiple sclerosis and psoriasis. Among others, the role of apoE in modulating inflammation and oxidation is crucial in elucidating the risk factors of the above diseases since the function of apoE is closely linked with both proinflammatory and antiinflammatory cytokines. Moreover, apoE modulates inflammatory and immune responses in an isoform-dependent manner. Correspondingly, inflammatory cytokines can either upregulate or downregulate the production of apoE in various tissue types. However, studies on the interactions between apoE and cytokines occasionally yield conflicting results, highlighting the complex roles of apoE and cytokines in various disorders. The present paper summarizes the current knowledge about the cross-talk between apoE and cytokines, with emphasis on the effects of apoE on the Th1/Th2 balance.

Antioxidant activities of recombinant amphioxus (Branchiostoma belcheri) apolipoprotein D

Apolipoprotein D (ApoD), a member of lipocalin, has been recently shown to be involved in regulating protection from oxidative stress. The absence of ApoD in mouse and Drosophila can reduce the resistance to oxidative stress and shorten lifespan. However, little information is available regarding the expression in vitro of ApoD and its biochemical properties. Amphioxus (Branchiostoma belcheri) ApoD, BbApoD, is an archetype of vertebrate ApoD proteins. In this study, the prokaryotic expression plasmid pET32a-BbApoD was constructed and recombinant BbApoD expressed in Escherichia coli BL21 and purified. Antioxidation assays showed that the recombinant BbApoD protein had the capacities to scavenge hydroxyl radicals (≥ 240 μg/ml) and to prevent nicking of the supercoiled DNA (≥ 100 μg/ml) in vitro, providing a biochemical evidence for antioxidant role of ApoD. This supports the notion that ApoD is part of the mechanisms regulating protection from oxidative stresses.