Association of serum level of apolipoprotein M with disease activity in systemic lupus erythematosus / 中南大学学报(医学版)

OBJECTIVE@#To explore the association of serum level of apolipoprotein M with disease activity in systemic lupus erythematosus (SLE).@*METHODS@#A total of 65 patients with SLE, who came to Second Xiangya Hospital for treatment from April to November in 2013 (SLE group) and 120 age-and sex-matched controls (control group) were studied. The SLE group was further divided into three groups according to systemic lupus erythematosus disease activity index (SLEDAI): a mild activity group, a moderate activity group and a severe activity group (n=16, 16, 33, respectively). The control group was also divided into a disease control group (n=60) and a healthy control group (n=60). The serum levels of apo M were measured by enzyme-linked immunosorbent assay (ELISA). Other indicators including TC, TG, HDL, LDL, apo A1, apo B, and anti-dsDNA antibody were detected. The correlation between SLEDAI or anti-dsDNA antibody and apo M was assessed.@*RESULTS@#Compared with the healthy control group, the expression levels of apo M and HDL were decreased significantly (both P0.05). The serum concentration of apo M was significant negatively correlated with SLEDAI and anti-dsDNA antibody (r=-0.551, -0.562, both P<0.01).@*CONCLUSION@#Compared with the healthy control group, the serum levels of apo M in patients with SLE are significantly decreased. The apo M is closely correlated with disease activity of SLE and it might be used as an indicator to monitor the disease activity of SLE.

Association between a new SNP in proximal promoter region of apolipoprotein M and susceptibility of coronary artery diseases in Han Chinese population / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the association between genetic polymorphisms of proximal promoter region of apolipoprotein M (apoM) gene and susceptibility of coronary artery diseases (CAD) in Han Chinese population.</p><p><b>METHODS</b>Two pairs of primers were designed according to the sequence (GenBank accession nos. EU030444.1) and the PCR products of apoM proximal promoter region were directly sequenced. Two hundred and six patients [165 males, mean age (61.9 ± 9.2) years old] diagnosed with CAD according to the results of angiography (a lesion was classed as being significant when stenosis was more than 50%) were enrolled in the present study, 209 age- and gender-matched patients[157 males, mean age (60.4 ± 9.1) years old] without CAD according to the results of angiography were selected as the control group. The allelic frequencies and genotype distributions of polymorphism in CAD and non-CAD patients were analyzed. Furthermore the wide-type and mutant promoter region of apoM were cloned into the luciferase expression vector pGL3, respectively. Luciferase reporter assay was used to detect the activity of apoM promoter.</p><p><b>RESULTS</b>A new deletion mutation -724delC in apoM promoter was found. The frequency of Del C allele was 8.0% in CAD patients and only 4.1% in the non-CAD controls (OR = 2.054, 95%CI 1.125-3.749, P = 0.017). The mean TC level was lower in groups with wide-type homozygotes compared to the mutant allele carriers [ (6.04 ± 0.90) mmol/L vs. (4.95 ± 1.00)mmol/L, P < 0.01]. -724delC mutant showed obvious decreased luciferase activities (1.13 ± 0.25 vs. 2.11 ± 0.15, P = 0.009).</p><p><b>CONCLUSION</b>It is reasonable to speculate that -724delC could affect the activity of the apoM promoter and downregulate apoM expressions, therefore, influence the susceptibility of CAD in this patient cohort.</p>

Apolipoprotein M expression in human colorectal cancer tissues and its clinicopathological relevance / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the mRNA and protein expression levels of apolipoprotein M (apoM) in the human colorectal cancer tissues, and to explore its clinical relevance.</p><p><b>METHODS</b>Real-time PCR was carried out to determine the mRNA expression levels both in cancer tissue and its adjacent normal tissue from 20 patients with colorectal cancer. Immunohistochemistry was also carried out to determine the protein levels in 23 colorectal biopsy samples (7 normal mucosa, 6 inflammatory mucosa and 10 polyp tissues) and 20 cases of colorectal cancer tissues as well as the adjacent normal tissues.</p><p><b>RESULTS</b>Real-time PCR result showed that apoM mRNA level in the colorectal cancer tissues was significantly lower than that in their adjacent normal tissues (0.05±0.01 vs. 0.19±0.05, P<0.05). ApoM mRNA level in colorectal cancer tissues was statistically significant higher in the patients with lymph node metastasis as compared to the patients without lymph node metastasis (P<0.01). The median value of apoM protein in cancer tissues was 5.50, which was significantly lower than that in the adjacent normal tissues (10.5, P<0.05), inflammatory mucosa tissues (9.75, P<0.05), polyp tissues (11.0, P<0.01) and normal mucosa (10.5, P<0.05). No significant association was observed between the apoM protein level and the clinicopathological parameters of patients.</p><p><b>CONCLUSIONS</b>Both apoM mRNA and protein expression levels in colorectal cancer tissues are significantly decreased in contrast to normal and benign colorectal tissues. The apoM mRNA expression in colorectal cancer tissues is closely associated with nodal metastasis.</p>

Reduced expression and secretion of apolipoprotein M in fat-fed, streptozotocin-diabetic rats is partially reversed by an artificial ligand of PPARγ / 中南大学学报(医学版)

OBJECTIVE@#To investigate the effect of administration of rosiglitazone, an artificial ligand of PPARγ, on the expression and secretion of apolipoprotein (apoM) in fat-fed, streptozotocin-treated rats, an animal model for type 2-like diabetes.@*METHODS@#Healthy male SD rats were divided into 4 groups: a control group (n=7), a high-fat chow group (HF group, n=8), a diabetes mellitus group (DM group, n=7), and a diabetes mellitus group with rosiglitazone intervention group (RSG group, n=7). Fasting blood glucose (FBG), fasting insulin (FINS), triglyceride (TG) and total cholesterol (TC) were measured at the beginning of the study. The diabetic rats model was established by feeding high fat chow and intraperitoneal injection of streprozotocin. Then the randomly selected treatment group was given rosiglitazone by daily gavage for 8 weeks. All the rats were killed at the fifteenth week, at which time blood and tissues (liver, kidney, adipose) were collected and prepared. The levels of FBG, FINS, TG and TC were assayed. The level of apoM in serum was measured by enzyme-linked immunosorbent assay (ELISA). Reverse transcription polymerase chain reaction (RT-PCR) was used to determine apoM mRNA expression in liver, kidney, and adipose tissues.@*RESULTS@#Compared with either control group or HF group, serum apoM concentration in the DM group was reduced significantly (P<0.05); compared with the DM group, however, serum apoM concentrations in RSG group were increased (P<0.05). The expression of apoM mRNA in liver was highest, in kidney medium, and in adipose tissue extremely low (P<0.05). ApoM mRNA expression in liver and kidney was decreased in both DM and HF groups compared to control group (P<0.05). But, as with serum apoM concentration, apoM mRNA in the liver, kidney and adipose tissues of the RSG group were all increased markedly (P<0.05). The level of serum apoM in SD rats correlated negatively with TG (r=-0.466, P=0.011), TC (r=-0.568, P= 0.001), FBS (r =-0.371, P<0.001), and FINS(r=-0.768, P= 0.048 ).@*CONCLUSION@#These results suggest that apoM may participate in the glucose and lipid metabolism by the regulation of PPARγ.

Expression and purification of human apolipoprotein M / 中南大学学报(医学版)

OBJECTIVE@#To express and purify the extra cellular full-length human apolipoprotein M(ApoM).@*METHODS@#The ApoM gene fragment was amplified from the human liver cDNA library by PCR. The resulting product was cloned into pGEXT vector and sequenced. Then the confirmed canstatin cDNA was cloned into plasmid E.coli JM109 and then transformed into E.coli DL21(DE3) where it was induced to express protein by IPTG.@*RESULTS@#The ApoM gene was cloned by PCR and a 560 bp DNA fragment was shown on the agarose electrophoresis. The cloned gene was sequenced and demonstrated to have the same sequence as that of human ApoM gene in GenBank. Then ApoM cDNA gene fragment was induced by IPTG, and a 24 kD recombinant ApoM protein was tested on SDS-PAGE.@*CONCLUSION@#Human ApoM gene is successfully cloned and its recombinant proteins are expressed.

Distribution characters and linkage disequilibrium analysis of APOM gene polymorphisms in Han population of North China / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the distribution characters and linkage disequilibrium of apolipoprotein M gene (APOM) polymorphisms in Han population of North China.</p><p><b>METHODS</b>The single nucleotide polymorphisms (SNPs) in six exons and five introns of APOM gene of 330 normal subjects in Han population of North China were detected by PCR-restriction fragment length polymorphism and DNA sequencing analysis.</p><p><b>RESULTS</b>Three SNPs in Han Chinese were found, including rs805264 of intron 1, rs707922 and rs707921 of intron 5 of APOM gene. The frequency distribution of these SNPs was different among different races and territory. In addition, linkage disequilibrium among the SNPs of rs805264, rs707922 and rs707921 of APOM gene was found and A-T-A and G-G-C were predominant haplotypes.</p><p><b>CONCLUSION</b>There is apparent linkage disequilibrium among SNPs of APOM gene in Han population of North China.</p>