Increased expression of CD200 on circulating CD11b+ monocytes in patients with neovascular age-related macular degeneration.

OBJECTIVE: Dysregulation of retinal microglial activity has been implicated in the pathogenesis of neovascular age-related macular degeneration. Microglia activity can be regulated through the membrane protein CD200 and its corresponding receptor, the CD200 receptor (CD200R). Because both the ligand and the receptor are expressed on a broad spectrum of cell types, we set out to study the expression of CD200 and CD200R on CD11b+ monocytes, granulocytes, and subsets of T lymphocytes. DESIGN: Prospective, case-control study. PARTICIPANTS: The study population consisted of 62 patients with neovascular age-related macular degeneration (AMD) and 44 age-matched controls without AMD. METHODS: The participants were aged 60 years or older, had no history of immune dysfunction or cancer, and were not receiving immune-modulating therapy. All participants were subjected to a structured interview, and detailed retinal imaging was performed: fundus autofluorescence imaging, digital color fundoscopy, and spectral-domain optical coherence tomography. Fluorescein and indocyanine green angiography were performed in patients with suspected neovascular AMD. Visual acuity was measured in both eyes. Fresh venous blood was obtained and stained with monoclonal antibodies and analyzed using flow cytometry within 6 hours of phlebotomy. MAIN OUTCOME MEASURES: The percentage of CD11b+ monocytes, granulocytes, and CD4+/CD8+ T lymphocytes positive for CD200 or CD200R in patients and controls, respectively. RESULTS: Patients with neovascular AMD had a higher percentage of CD11b+CD200+ monocytes and CD200+ monocytes compared with controls. Multiple regression analysis revealed that the intergroup differences observed were independent of age. Moreover, an age-related increment in CD200 expression on monocytes was observed in controls with healthy eyes, but not in patients with neovascular AMD. We did not find any differences in CD200 and CD200R expression between patients with subretinal fibrosis and patients without subretinal fibrosis. CONCLUSIONS: The surface expression of CD200 on circulating CD11b+ monocytes was found to be increased in patients with neovascular AMD compared with controls with healthy eyes. This novel finding supports the notion that altered regulation of the inflammatory response plays an integral role in the pathogenesis of AMD. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Gene expression profiling of placentas affected by pre-eclampsia.

Several studies point to the placenta as the primary cause of pre-eclampsia. Our objective was to identify placental genes that may contribute to the development of pre-eclampsia. RNA was purified from tissue biopsies from eleven pre-eclamptic placentas and eighteen normal controls. Messenger RNA expression from pooled samples was analysed by microarrays. Verification of the expression of selected genes was performed using real-time PCR. A surprisingly low number of genes (21 out of 15,000) were identified as differentially expressed. Among these were genes not previously associated with pre-eclampsia as bradykinin B1 receptor and a 14-3-3 protein, but also genes that have already been connected with pre-eclampsia, for example, inhibin beta A subunit and leptin. A low number of genes were repeatedly identified as differentially expressed, because they may represent the endpoint of a cascade of events effectuated throughout gestation. They were associated with transcriptional regulation and vasoregulative pathways, along with a number of hypothetical proteins and gene sequences with unknown functions.

Identification of differences in gene expression in primary cell cultures of human endometrial epithelial cells and trophoblast cells following their interaction.

BACKGROUND: The interaction between epithelial cells of endometrium and trophoblast cells during implantation is presumed to be accompanied by a change in gene expression in the cell types involved. The objective of this study was to identify such differentially expressed genes. METHODS: The interaction between the cell types was simulated in vitro by growing primary cell cultures of human endometrial epithelial cells and trophoblast cells together (co-culture) and separately (control cultures). Gene expression in the cell cultures was compared using the Differential Display method and confirmed using a modified Northern Blot method. RESULTS: Twelve transcripts were identified as being differentially expressed following the interaction between trophoblast and endometrial cells. Some of these sequences show homology to known human genes while other sequences are coding for potential novel genes: (1) one sequence was homologous to the to Homer 1 gene, (2) one identical to the mRNA for XP-G factor, (3) one similar to a hypothetical protein, (4) transcripts showing homologies to a mRNA coding for a cellular proapoptotic protein, and (5) sequences homologous to regions on human chromosomes 5 and 16. Besides, some differentially expressed transcripts have sequences, which could be translated into ribosomal proteins or possibly code for novel proteins. CONCLUSION: These sequences may be important to the course of events following the interaction between endometrial epithelial and trophoblast cells and responsible for implantation.

Altered expression of CD46 and CD59 on leukocytes in neovascular age-related macular degeneration.

PURPOSE: To investigate the expression of the complement regulatory proteins CD46, CD55, and CD59 on peripheral leukocytes in neovascular age-related macular degeneration (AMD). DESIGN: Prospective, case-control study. METHODS: Thirty-five unrelated patients with neovascular AMD and 30 control individuals were included in this case-control study. All participants were subjected to a structured interview and detailed imaging (autofluorescence, digital funduscopy, spectral-domain optical coherence tomography, and fluorescein and indocyanine green angiography in patients suspected of having neovascular AMD) was performed. Fresh ethylenediamine-tetraacetic acid blood was obtained and stained with monoclonal antibodies. Using flow cytometry, the percentage of CD14(+) monocytes, CD45(+) lymphocytes, and CD45(+) granulocytes positive for CD46, CD55, and CD59 was determined in patients with neovascular AMD and was compared with that of controls. RESULTS: We found that the expression of CD46 and CD59 was significantly lower on CD14(+) monocytes in patients with neovascular AMD compared with controls (P = .0070). A significantly lower expression of CD46 on lymphocytes was observed in patients with fibrosis compared with patients without fibrosis (P = .010). CONCLUSIONS: Our study suggests that neovascular AMD is associated with an inadequate regulation of the complement system, supporting current evidence on the role of complement dysregulation in the pathogenesis of AMD.