Expression of CD18 on the neutrophils of patients with diabetic retinopathy

Polymorphonuclear phenotypical expression of CD18, at baseline and after in vitro activation, in several clinical disorders: Revision of our case series

BACKGROUND

In relation to the different and important roles of the beta2 integrins, we have revisited the expression of polymorphonuclear leukocyte CD18 in several clinical disorders, at baseline and after in vitro activation.

SUBJECTS

we have examined subjects with type 1 diabetes mellitus, vascular atherosclerotic disease, type 2 diabetes mellitus without and with macrovascular complications, chronic renal failure on conservative treatment, essential hypertension, deep venous thrombosis, acute ischemic stroke and subjects with venous leg ulcers.

METHODS

unfractioned leukocyte suspension was prepared according to the Mikita's method, while the leukocyte were separated into mononuclear and polymorphonuclear cells with a Ficoll-Hypaque medium. Using specific monoclonal antibody, the CD18 expression was evaluated with cytofluorimetric analysis, using FACScan (Becton Dickinson) be Cellquest software; the activation in vitro with PMA was effected according to modified Yasui and Masuda methods.

RESULTS

in type 1 diabetes mellitus, at baseline CD18 is under expressed in comparison with normal control, and not changes after PMA activation were observed; in subjects with vascular atherosclerotic disease, in type 2 diabetes mellitus CD18 is over expressed at baseline but does not vary after activation; in subjects with chronic renal failure, essential hypertension and in subjects with acute ischemic stroke the CD18 up-regulate at baseline compared to normal control, and it increases further after activation; in subjects with deep venous thrombosis the CD18 expression is not different from control group at baseline, but it increases after activation; finally, in subjects with venous leg ulcers the CD18 is normally expressed at baseline, and it does not change after PMA activation.

CONCLUSIONS

in the different clinical disorders, the trend of this integrin subunit provides some specific information, useful to select the best therapeutic strategy in clinical practice.

Sequential and Dynamic Variations of IL-6, CD18, ICAM, TNF-α, and Microstructure in the Early Stage of Diabetic Retinopathy

Objective

The purpose of this project is to make sequential and indepth observation of the variations of retinal microvascular, microstructure, and inflammatory mediators at the early stage of diabetic retinopathy (DR) in streptozotocin-induced diabetes mellitus (DM) rats.

Methods

DM was induced by a single intraperitoneal injection of 60 mg/kg body weight streptozotocin (STZ). The fluorescein fundus angiography, hematoxylin and eosin staining, periodic acid-Schiff staining, fluorescence imaging techniques, quantitative real-time PCR, and vascular endothelial growth factor- (VEGF-) A ELISA were performed on the 8^th day, at the 4^th week, 6^th week, 8^th week, and 10^th week after DM induction, respectively.

Results

In this study, we observed not only the decrease of retinal ganglion cells (RGCs) and the increase of endotheliocytes to pericytes (E/P) ratio, acellular capillaries, and type IV collagen-positive strands began to occur on the 8^th day after induction but the vascular permeability and new vessel buds began to appear in the diabetes group at the 8^th week, while the expression of VEGF-A, VEGF mRNA, IL-6 mRNA, ICAM mRNA, and TNF-α mRNA were significantly higher in the diabetes group compared with the normal group(P < 0.01) on the 8^th day after induction and maintained a high expression level throughout the 10-week observation period. However, the expression of CD18 mRNA began to increase significantly at the 4^th week after induction and reached a peak at the 6^th week.

Conclusion

Our study indicated the abnormal alterations of microvessels, microstructure, and inflammatory mediators at the early stage of DR, which confirms and supplements the previous research, and also promotes an indepth understanding and exploration of the pathophysiology and underlying pathogenesis of DR.

CD8+T Cell-Related Gene Biomarkers in Macular Edema of Diabetic Retinopathy

BACKGROUND

CD8+T lymphocytes have a strong pro-inflammatory effect in all parts of the tissue, and some studies have demonstrated that its concentration in the vitreous increased significantly, suggesting that CD8+T cells play a pivotal role in the inflammatory response of diabetic retinopathy (DR). However, the infiltration of CD8+T cells in the DR retina, especially in diabetic macular edema (DME), and its related genes are still unclear.

METHODS

Download the GSE16036 dataset from the Gene Expression Omnibus (GEO) database. The ImmuCellAI program was performed to evaluate the abundance of 24 immune cells including CD8+T cells. The CD8+T cell-related genes (DECD8+TRGs) between non-proliferative diabetic retinopathy (NPDR) and DME were detected via difference analysis and correlation analysis. Enrichment analysis and protein-protein interaction (PPI) network mapping were implemented to explore the potential function of DECD8+TRGs. Lasso regression, support vector machine recursive feature elimination (SVM-RFE), CytoHubba plug-in and MCODE plug-in in Cytoscape software, and Weighted Gene Co-Expression Network Analysis (WGCNA) were performed to comprehensively analyze and obtain Hub DECD8+TRGs. Hub DECD8+TRGs expression patterns were further validated in other two DR-related independent datasets. The CD8+TRG score was defined as the genetic characterization of Hub DECD8+TRGs using the GSVA sample scoring method, which can be administered to distinguish early and advanced diabetic nephropathy (DN) as well as normal and DN. Finally, the transcription level of DECD8+TRGs in DR model mouse were verified by quantitative real-time PCR (qPCR).

RESULTS

A total of 371 DECD8+TRGs were identified, of which 294 genes were positively correlated and only 77 genes were negatively correlated. Eight genes (IKZF1, PTPRC, ITGB2, ITGAX, TLR7, LYN, CD74, SPI1) were recognized as Hub DECD8+TRGs. DR and DN, which have strong clinical correlation, have been proved to be associated with CD8+T cell-related hub genes by multiple independent data sets. Hub DECD8+TRGs can not only distinguish PDR from normal and DN from normal, but also play a role in the early and progressive stages of the two diseases (NPDR vs DME, Early DN vs Advanced DN). The qPCR transcription level and trend of Hub DECD8+TRGs in DR mouse model was basically the same as that in human transcriptome.

CONCLUSION

This study not only increases our understanding of the molecular mechanism of CD8+T cells in the progression of DME, but also expands people's cognitive vision of the molecular mechanism of crosstalk of CD8+T cells in the eyes and kidneys of patients with diabetes.

Integrins: An Important Link between Angiogenesis, Inflammation and Eye Diseases

Integrins belong to a group of cell adhesion molecules (CAMs) which is a large group of membrane-bound proteins. They are responsible for cell attachment to the extracellular matrix (ECM) and signal transduction from the ECM to the cells. Integrins take part in many other biological activities, such as extravasation, cell-to-cell adhesion, migration, cytokine activation and release, and act as receptors for some viruses, including severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2). They play a pivotal role in cell proliferation, migration, apoptosis, tissue repair and are involved in the processes that are crucial to infection, inflammation and angiogenesis. Integrins have an important part in normal development and tissue homeostasis, and also in the development of pathological processes in the eye. This review presents the available evidence from human and animal research into integrin structure, classification, function and their role in inflammation, infection and angiogenesis in ocular diseases. Integrin receptors and ligands are clinically interesting and may be promising as new therapeutic targets in the treatment of some eye disorders.

Molecular and Pathophysiological Mechanisms of Diabetic Retinopathy in Relation to Adhesion Molecules

Diabetic Retinopathy (DR) is considered as a most common microvascular complication of diabetes affected by one in three people who are suffered for diabetes. Several pathophysiological mechanisms and adhesion molecules may play an etiologic role in the development of diabetes and its complications. The adhesion molecules located on both leucocytes and endothelial cells and considered as important molecules which can assessed the endothelial function. The functions of adhesion molecules involved in the cellular margination, slow rolling and transmigration of leukocytes. Hyperglycemia and its immediate biochemical sequelae or the low-grade inflammation directly alter endothelial function or influence endothelial cell functioning indirectly by induce oxidative stress and activates leukocytosis and leukocyte-endothelial cell interactions by the increased expression of adhesion molecules, growth factors, inflammatory factors, chemokines etc. and results DR. This review summarized the several pathophysiological mechanisms and role of adhesion molecules in disruption of homeostasis of vasculature by leukocytes in the development of diabetic retinopathy.

Danhong Huayu Koufuye Prevents Diabetic Retinopathy in Streptozotocin-Induced Diabetic Rats via Antioxidation and Anti-Inflammation

Danhong Huayu Koufuye (DHK), a traditional Chinese prescription, is used to treat central retinal vein occlusion clinically. We previously reported that DHK prevented diabetic retinopathy (DR) in rats. Moreover, we found that it protected endothelial cells from hyperglycemia-induced apoptosis through antioxidation and anti-inflammation. Here, we investigated whether antioxidative and anti-inflammatory activities of DHK contributed to its therapeutic effect on DR in streptozotocin- (STZ-) induced diabetic rats. DHK significantly blocked the breakdown of the blood-retinal barrier (BRB) and increased the thickness of the inner nuclear layer (INL), as well as suppressed the swelling of the ganglion cell layer (GCL) in diabetic retinas. DHK remarkably increased the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) in plasma, and decreased serum level of nitric oxide (NO). Moreover, DHK markedly reduced the serum levels of vascular endothelial growth factor (VEGF) and intercellular adhesion molecule-1 (ICAM-1). Furthermore, DHK significantly downregulated protein expressions of VEGF and inducible NO synthase (iNOS) and mRNA expression of ICAM-1 in retinas. These results suggest that the antioxidative and anti-inflammatory activities of DHK may be important mechanisms involved in the protective effect of DHK on DR in STZ-induced diabetic rats.

Lymphoblastoid Cell Lines as a Tool to Study Inter-Individual Differences in the Response to Glucose

Background

White blood cells have been shown in animal studies to play a central role in the pathogenesis of diabetic retinopathy. Lymphoblastoid cells are immortalized EBV-transformed primary B-cell leukocytes that have been extensively used as a model for conditions in which white blood cells play a primary role. The purpose of this study was to investigate whether lymphoblastoid cell lines, by retaining many of the key features of primary leukocytes, can be induced with glucose to demonstrate relevant biological responses to those found in diabetic retinopathy.

Methods

Lymphoblastoid cell lines were obtained from twenty-three human subjects. Differences between high and standard glucose conditions were assessed for expression, endothelial adhesion, and reactive oxygen species.

Results

Collectively, stimulation of the lymphoblastoid cell lines with high glucose demonstrated corresponding changes on molecular, cellular and functional levels. Lymphoblastoid cell lines up-regulated expression of a panel of genes associated with the leukocyte-mediated inflammation found in diabetic retinopathy that include: a cytokine (IL-1B fold change = 2.11, p-value = 0.02), an enzyme (PKCB fold change = 2.30, p-value = 0.01), transcription factors (NFKB-p50 fold change = 2.05, p-value = 0.01), (NFKB-p65 fold change = 2.82, p-value = 0.003), and an adhesion molecule (CD18 fold change = 2.59, 0.02). Protein expression of CD18 was also increased (p-value = 2.14x10^-5). The lymphoblastoid cell lines demonstrated increased adhesiveness to endothelial cells (p = 1.28x10^-5). Reactive oxygen species were increased (p = 2.56x10^-6). Significant inter-individual variation among the lymphoblastoid cell lines in these responses was evident (F = 18.70, p < 0.0001).

Conclusions

Exposure of lymphoblastoid cell lines derived from different human subjects to high glucose demonstrated differential and heterogeneous gene expression, adhesion, and cellular effects that recapitulated features found in the diabetic state. Lymphoblastoid cells may represent a useful tool to guide an individualized understanding of the development and potential treatment of diabetic complications like retinopathy.

CD18 expression in granulocytes infiltrating the vitreous fluid in patients with diabetic retinopathy

AIM

To assess the levels of CD18 on the surface of granulocytes infiltrating the vitreous fluid in patients with diabetic retinopathy (DR).

METHODS

Vitreous samples from twelve patients with non-proliferative DR with significant macula edema (group A), 33 patients with proliferative DR (grade 3 as group B, n=14, and, grade 4 as group C, n=19) were obtained during pars plana vitrectomy. Vitreous samples from 12 patients with macular hole as controls (group D) were analyzed together. The infiltrating of granulocytes and its surface level of CD18 were measured by flow cytometry. The level of CD18 was presented as the mean channel fluorescence (MCF) on a logarithmic scale.

RESULTS

Granulocytes were detected in 6 of 12 vitreous samples from group A, 9 of 14 from group B, 15 of 19 from group C, and none of 12 from group D. MCF of CD18 on granulocytes from groups A, B, and C were 2.978±1.446, 3.201±0.692, and 4.072±0.837, respectively. The difference was significant (F=4.354, P=0.021). Subjects with more severe DR were more likely to have a higher level of CD18 MCF (trend test, χ (2)=7.351, P=0.007). CD18 MCF was significantly associated with the development of DR (r=0.46, P=0.005 and β=0.147, P=0.035).

CONCLUSION

Our results confirm the presence of granulocytes and the elevated levels of CD18 on the surface of them in the vitreous fluid from DR patients. These results may provide indirect evidence shown that granulocytes activation also has occurred in the retinal local compared to non-DR control.

Usefulness of the vitreous fluid analysis in the translational research of diabetic retinopathy

Diabetic retinopathy (DR) is the major cause of acquired blindness in working-age adults. Current treatments for DR (laser photocoagulation, intravitreal corticosteroids, intravitreal antivascular endothelial growth factor (VEGF) agents, and vitreo-retinal surgery) are applicable only at advanced stages of the disease and are associated with significant adverse effects. Therefore, new pharmacological treatments for the early stages of the disease are needed. Vitreous fluid obtained from diabetic patients undergoing vitreoretinal surgery is currently used to explore the events that are taking place in the retina for clinical research. However, several confounding factors such as vitreous haemorrhage and concentration of vitreous proteins should be considered in the analysis of the results. In this paper we will focus on the vitreous fluid as a tool for exploring the mediators of DR and in particular the molecules related to inflammatory pathways. In addition, their role in the pathogenesis of DR will be discussed. The usefulness of new technologies such as flow cytometry and proteomics in identifying new candidates involved in the inflammatory process that occurs in DR will be overviewed. Finally, a more personalized treatment based on vitreous fluid analysis aiming to reduce the burden associated with DR is suggested.

Neural inflammation and the microglial response in diabetic retinopathy

This chapter reviews the function of microglia and their potential roles in neural inflammation and pathological changes during diabetic retinopathy.

Different expression pattern of serum soluble intercellular adhesion molecules-1 and neutrophilic expression of CD18 in patients with diabetic retinopathy

AIM

To investigate the levels of serum soluble intercellular adhesion molecules-1(sICAM-1) and neutrophilic expression of CD18 in patients with various stages of diabetic retinopathy and to determine their different expression pattern in the development of diabetic retinopathy(DR).

METHODS

Levels of serum sICAM-1 and CD18 on the surface of neutrophile were measured in 41 DR patients, they were classified in three subgroups according to the stage of retinopathy as determined by fund's ophthalmoscopy; 10 control subjects were also studied. sICAM-1 were measured by enzyme-linked immunosorbent assay and CD18 by flow cytometry.

RESULTS

The neutrophilic CD18 expression and serum sICAM-1 level were all significantly elevated in all diabetic subgroups compared to control subjects (P<0.01). The differences of CD18 and sICAM-1 among the diabetic subgroups were significant in CD18 but not in sICAM-1. The progression of retinopathy was associated with an increase both in CD18 and in sICAM-1 levels by simple correlation analysis (β=0.74, P<0.001; β=0.38, P<0.01, respectively). But stepwise multiple regression analysis revealed that only CD18 was independent determinant of retinopathy (β=1.04, P<0.01).

CONCLUSION

Our results confirm the contribution of endothelial and neutrophilic activation in the development of DR as indicated by increased levels of CD18 and sICAM-1. However, a direct implication of CD18 and ICAM-1 in the progression of DR can be supported only in the CD18 but not ICAM-1. CD18 and ICAM-1 may play different role in the development of diabetic retinopathy.

Complement involvement in neovascular ocular diseases

Pathological neovascularization (NV) is a hallmark of late stage neovascular age-related macular degeneration (AMD), diabetic retinopathy (DR), and retinopathy of prematurity (ROP). There is accumulating evidence that alterations in inflammatory and immune system pathways that arise from genetic differences, injury, and disease can predispose individuals to retinal neovascular eye diseases. Yet the mechanism of disease progression with respect to the complement system in these maladies is not fully understood. Recent studies have implicated the complement system as an emerging player in the etiology of several retinal diseases. We will summarize herein several of the complement system pathways known to be involved in ocular neovascular pathologies. Current treatment for many neovascular eye diseases focuses on suppression of NV with laser ablation, photodynamic therapy, or anti-VEGF angiogenic inhibitors. However, these treatments do not address the underlying cause of many of these diseases. A clear understanding of the cellular and molecular mechanisms could bring a major shift in our approach to disease treatment and prevention.

Leukocyte adhesion molecules in diabetic retinopathy

Diabetes is a systemic disease that causes a number of metabolic and physiologic abnormalities. One of the major microvascular complications of diabetes is diabetic retinopathy (DR), a leading cause of blindness in people over age 50. The mechanisms underlying the development of DR are not fully understood; however, extensive studies have recently implicated chronic, low-grade inflammation in the pathophysiology of DR. During inflammation leukocytes undergo sequential adhesive interactions with endothelial cells to migrate into the inflamed tissues, a process known as the “leukocyte recruitment cascade” which is orchestrated by precise adhesion molecule expression on the cell surface of leukocytes and the endothelium. This paper summarizes the recent clinical and preclinical works on the roles of leukocyte adhesion molecules in DR.

Reduced expression of β2 integrin genes in rat peripheral leukocytes by inhibiting postprandial hyperglycemia

β(2) integrins (CD11s/CD18) promote the attachment of leukocytes to vascular endothelial cells. We performed in this study sucrose loading to rats with moderate postprandial hyperglycemia with/without once-daily dosing of the α-glucosidase inhibitor, miglitol, for 4 days under 4-h fasting conditions. The streptozotocin (STZ)-treated rats showed moderate postprandial hyperglycemia on days 1 and 4. The gene expression was higher for CD11a with fasting and 3-h postprandial on day 1, and with fasting on day 4, for CD11b with fasting on day 1 and 3-h postprandial on day 4, and for CD18 with fasting on days 1 and 4 in peripheral leukocytes from the STZ-treated rats than in peripheral leukocytes from the saline-treated rats. Miglitol reduced postprandial hyperglycemia and the gene expression of CD11a with fasting and of CD11b 3-h postprandial on day 4. These results indicate that inhibiting postprandial hyperglycemia reduced the mRNA expression of β(2) integrins in peripheral leukocytes of moderately postprandial hyperglycemic rats.

The paradox of the neutrophil's role in tissue injury

The neutrophil is an essential component of the innate immune system, and its function is vital to human life. Its production increases in response to virtually all forms of inflammation, and subsequently, it can accumulate in blood and tissue to varying degrees. Although its participation in the inflammatory response is often salutary by nature of its normal interaction with vascular endothelium and its capability to enter tissues and respond to chemotactic gradients and to phagocytize and kill microrganisms, it can contribute to processes that impair vascular integrity and blood flow. The mechanisms that the neutrophil uses to kill microorganisms also have the potential to injure normal tissue under special circumstances. Its paradoxical role in the pathophysiology of disease is particularly, but not exclusively, notable in seven circumstances: 1) diabetic retinopathy, 2) sickle cell disease, 3) TRALI, 4) ARDS, 5) renal microvasculopathy, 6) stroke, and 7) acute coronary artery syndrome. The activated neutrophil's capability to become adhesive to endothelium, to generate highly ROS, and to secrete proteases gives it the potential to induce local vascular and tissue injury. In this review, we summarize the evidence for its role as a mediator of tissue injury in these seven conditions, making it or its products potential therapeutic targets.

Immunological mechanisms in the pathogenesis of diabetic retinopathy

There is an accumulating body of evidence that immunological mechanisms play a prominent role in the pathogenesis of diabetic retinopathy (DR), which is characterized by many features typical of inflammation. The upregulation of cytokines and other inflammatory mediators leading to persistent low-grade inflammation and an influx of leukocytes, is believed to contribute actively to DR-associated damage to the retinal vasculature and retinal neovascularization. This review will describe preclinical and clinical studies that document an inflammatory basis for DR and that support the use of nonsteroidal anti-inflammatory drugs, corticosteroids, and anti-vascular endothelial growth factor agents in its treatment. In addition, emerging therapeutic approaches based on ongoing investigations will be discussed, including those involving blockade of angiotensin receptors and other molecular targets such as tumor necrosis factor-alpha.

Structural alterations of the erythrocyte membrane proteins in diabetic retinopathy

BACKGROUND

Several rheological disorders of the erythrocytes, such as increased aggregation and decreased deformability, have been observed in diabetes mellitus and have been implicated in the development of diabetic microangiopathy. Structural alterations of the erythrocyte membrane proteins caused by the diabetic process may be at the origin of those observations. In the present study, we searched for erythrocyte membrane protein alterations in diabetic retinopathy.

METHODS

We examined peripheral blood samples from 40 type-2 diabetic patients with diabetic retinopathy of variable severity (19 males and 21 females, mean age 66.8 years, Group A) and we compared them with samples from 19 type-2 diabetic patients without diabetic retinopathy (13 males and six females, mean age 66.5 years, Group B) and 16 healthy volunteers (eight males and eight females, mean age 65.6 years, Group C). Erythrocyte membrane ghosts from all samples were subjected to SDS-PAGE, and the electrophoretic pattern of transmembrane and cytoskeletal proteins was analysed for each sample. The protein quantification of each electrophoretic band was accomplished through scanning densitometry.

RESULTS

No significant deviations from normal electrophoresis were observed in Groups B and C, apart from an increase in band 8 in two samples from Group B (11%). In contrast, in 14 samples from Group A (35%) we detected increases in protein band 8 and/or membrane-bound haemoglobin along with a decrease in spectrin. Moreover, increased mobility of band 3, an aberrant high molecular weight (MW) (> 255 kDa) band and a low MW (42 kDa) band were evident in ten samples from Group A (25%). Glycophorins were altered in 46% of Group-A patients versus 38% of Group-B patients. Females and patients with long duration of diabetes presented more electrophoretic abnormalities.

CONCLUSIONS

Structural alterations of the erythrocyte membrane proteins are shown for the first time in association with diabetic retinopathy. Their detection may serve as a blood marker for the development of diabetic microangiopathy. Further studies are needed to assess whether pharmaceutical intervention to the rheology of erythrocytes can prevent or alleviate microvascular diabetic complications.

Alterations in cell adhesion molecules and other biomarkers of cardiovascular disease in patients with metabolic syndrome

Metabolic syndrome is considered a hyperinsulinemic and inflammatory state closely associated to endothelial dysfunction causing an increased incidence of ischemic cardiovascular events and high mortality. The main objective of the present study was to determine whether leukocitary and soluble cell adhesion molecules were altered in patients with metabolic syndrome in comparison with control subjects. Cell adhesion molecules, mainly of leukocitary location, have been not previously evaluated in specifically designed cross-sectional studies involving male patients with metabolic syndrome. Moreover, other circulating markers of different candidate atherogenic risk parameters were also studied and the potential existence of a progressive relation between the number of metabolic syndrome components and the above mentioned biomarkers was analyzed. Thirty one male patients with metabolic syndrome (ATPIII definition) and 56 male control subjects were studied. We evaluated different markers of insulin resistance, inflammation and atherosclerosis, as well as protective factors. Patients with metabolic syndrome showed (a) hypoadiponectinemia (4551 +/- 2302 ng/ml vs. 5865 +/- 2548 ng/ml, respectively; p<0.05), (b) an atherogenic lipid and lipoprotein profile, (c) altered HDL chemical composition accompanied by higher cholesteryl ester-triglyceride interchange carried out by CETP, (d) diminished Lp-PLA(2) activity (6.5 +/- 1.9 vs. 7.3 +/- 2.2, p<0.05, respectively), antioxidant enzyme related with LDL oxidation, which was positively associated with QUICKI and negatively with VCAM-1 and lymphocyte CD18, and (e) high soluble (VCAM-1: 17 +/-5 vs. 13 +/- 4 ng/ml, respectively; p<0.0005) and leukocyte adhesion molecule expression (monocyte CD54: 52 +/- 15 vs. 45 +/-12 arbitrary units, respectively; p<0.0005; and lymphocyte CD49d: 312 +/- 56 vs. 284 +/- 64 arbitrary units, respectively; p < 0.05). The increment in leukocyte and soluble cell adhesion molecules, crucial for leukocyte interaction with the endothelium and migration into the artery wall, in combination with the other disorders described above reinforce the presence of a clinical status with high propensity to type 2 diabetes and atherosclerotic cardiovascular disease.

Endothelial and leukocyte adhesion molecules in primary hypertriglyceridemia

Hypertriglyceridemia is known to be associated to functional impairment of the endothelium and, consequently, to higher risk of atherosclerosis. Nevertheless, some crucial steps in the development of the atherosclerotic plaque are still unknown in primary hypertriglyceridemia. The aim of the present study was to explore the expression of soluble and leukocyte-associated cell adhesion molecules in a group of patients with primary hypertriglyceridemia, both including (n=50) and excluding (n=24) subjects with metabolic syndrome, in comparison with control normotriglyceridemic individuals (n=30). Lipid profile, CETP activity, HDL and VLDL chemical composition were evaluated. Soluble (VCAM-1, ICAM-1 and E-selectin) and leukocyte cell adhesion molecules (CD18, CD49d and CD54) were measured by enzyme-linked immunosorbent assay and flow cytometry, respectively. Patients with primary hypertriglyceridemia as compared with control subjects showed significantly higher VCAM-1 (15.6+/-4.5 ng/ml versus 13.9+/-3.8 ng/ml, respectively; p<0.05) and ICAM-1 (16.9+/-3.1 ng/ml versus 15.2+/-3.2 ng/ml, respectively; p<0.05). Regarding leukocyte cell adhesion molecules, significant increases were also detected in monocyte CD18 (398+/-180 versus 332+/-136 arbitrary units, respectively; p<0.05) and CD54 (49+/-14 versus 42+/-12 arbitrary units, respectively; p<0.05), and lymphocyte CD18 (122+/-53 versus 101+/-33 arbitrary units, respectively; p<0.05). ICAM-1 plasma levels, as well as monocyte CD18 and CD54, and lymphocyte CD18 persisted elevated even if patients with metabolic syndrome were discarded among those with hypertriglyceridemia. The increase in circulating and leukocyte cell adhesion molecules in primary hypertriglyceridemic patients would highlight the inflammatory process which is a key event in atherogenesis.