Plasma VCAM1 levels correlate with disease severity in Parkinson's disease

BACKGROUND

Parkinson's disease (PD) is a progressive neurodegenerative disease characterized by motor and non-motor symptoms. There is increasing evidence that PD pathology is accompanied by an inflammatory response. This is highly relevant for understanding disease progression and the development of novel neuroprotective therapies.

OBJECTIVE

Assessing potential dysregulation of a panel of inflammatory mediators in the peripheral blood mononuclear cells (PBMCs) and plasma of PD patients and in the context of clinical outcome metrics.

METHODS

We performed a screening of selected cell-surface chemokine receptors and adhesion molecules in PBMCs from PD patients and age-matched healthy controls in a flow cytometry-based assay. ELISA was used to quantify VCAM1 levels in the plasma of PD patients. Lymphocytic chemotactic ability was assessed using a modified Boyden chamber assay.

RESULTS

VLA4 expression was significantly downregulated on CD3+ T cells, CD56+ NK cells, and CD3+/CD56+ NK-T cells from PD patients; further, an increase of the soluble VLA4 ligand VCAM1 in patient plasma was noted. sVCAM1 in PD patients was even higher than reported for patients with multiple sclerosis, neuromyelitis optica, and rheumatoid arthritis. sVCAM1 levels correlated with the disease stage (Hoehn and Yahr scale) and motor impairment. Chemoattraction with SDF-1α revealed impaired motility of lymphocytes from PD patients relative to controls.

CONCLUSION

Our data provides evidence for a functional dysregulation of the sVCAM1-VLA4 axis in PD. Further studies evaluating the therapeutic potential of this axis are warranted.

The pathogenic relevance of the prognostic markers CD38 and CD49d in chronic lymphocytic leukemia

The interactions of chronic lymphocytic leukemia cells with the microenvironment in secondary lymphoid tissues and the bone marrow are known to promote CLL cell survival and proliferation. CD38 and CD49d are both independent prognostic risk parameters in CLL with important roles in shaping these interactions. Both are reported to influence CLL cell trafficking between blood and lymphoid organs as well as their survival and proliferation within the lymphoid organs, thereby impacting the pathophysiology of the disease. The expression of CD38 and CD49d is associated in the majority of cases, and they exist as part of macromolecular complexes. Here, we review the current evidence for the individual and associated contributions of these molecules to CLL pathophysiology.

A direct comparison of expression profiles of adhesion molecules on naïve T cells between cord blood and steady-state bone marrow grafts of healthy donors

INTRODUCTION

We compared the profiles of adhesion molecule expression on naïve T cells between umbilical cord blood (UCB) and steady-state bone marrow (SS-BM) grafts.

METHODS

The expressions of 4 adhesion molecules, including very late antigen 4 (VLA-4), intercellular adhesion molecule-1 (ICAM-1), L-selectin, and lymophocyte function-associated antigen-1 (LFA-1) on naïve T cells in UCB (n = 25) and SS-BM (n = 10) were analyzed using flow cytometry.

RESULTS

The expressions of ICAM-1 and L-selectin on CD4(+) T cells and CD8(+) T cells in UCB were significantly lower than those on SS-BM (P < .05 for all). The expressions of VLA-4 and LFA-1 on CD8(+) T cells in UCB were significantly lower than those of SS-BM (P = .002 and .047, respectively). Compared with SS-BM, we observed lower expression of ICAM-1 on naïve CD4(+) and CD8(+) T cells in UCB (P < .001 for all). The percentages of interferon (IFN)-γ positive cells among naïve CD4(+) and CD8(+) T-cell subsets were significantly lower in UCB, leading to ready polarization of naïve UCB T cells from a Th1 to Th2 phenotype versus those on SS-BM.

CONCLUSIONS

Our results among UCB suggested lower intensities of ICAM-1 expression on naïve T cells and their easier polarization from Th1 to Th2 elements.

Differential bone marrow homing capacity of VLA-4 and CD38 high expressing chronic lymphocytic leukemia cells

Background

VLA-4 and CD38 predict a poor clinical outcome in chronic lymphocytic leukemia (CLL). We used CLL samples with discordant VLA-4/CD38 risk to address their individual roles in human bone marrow infiltration (BM), CLL cell homing to murine BM, and in supportive CLL cell-stromal cell interactions.

Methods

VLA-4, CD38, and Ki-67 expression was measured in CLL cells from peripheral blood (PB) and bone marrow (BM) aspirates. CLL BM infiltration rates, routinely determined by Pathology, were correlated to VLA-4 and CD38 expression. Short-term homing capacity of CLL cells was evaluated by adoptive transfer experiments. CLL cell viability and adhesion in stromal cell co-culture was determined.

Results

About 20% of CLL samples in our cohort displayed discordant VLA-4 and CD38 risk, with either high VLA-4 and low CD38 risk or vice versa. Using particularly such samples, we observed that VLA-4, and not CD38, was responsible for recirculation of CLL cells to murine BM. Human BM infiltration was also significantly higher in patients with high VLA-4 risk but not high CD38 risk. However, both molecules acted as independent prognostic markers. While both VLA-4 and CD38 expression were increased in BM-derived CLL cells, and VLA-4+ and CD38+ subpopulations showed enriched Ki-67 expression, VLA-4 did not contribute to CLL cell protection by stromal cells in vitro.

Conclusions

Our data argue for a prominent role of VLA-4 but not CD38 expression in the homing of CLL cells to BM niches and in human BM infiltration,but only a limited role in their protection by stromal cells.

Quantitation of peripheral blood markers of rat experimental autoimmune encephalomyelitis

Identification and quantitation of peripheral blood non-invasive, cell-surface markers of EAE disease activity and drug response would facilitate the preclinical development of potential therapeutics. Towards this end, we characterized the influx of immune mediators into spinal cords of diseased rats to establish the kinetics of T cell and monocyte-mediated inflammation. We then examined the periphery for regulation of T cell and monocyte activation. We report increased CD80 and VLA-4 expression on peripheral blood monocytes (PBM) during the onset and peak of experimental disease scores. Increased CD4+, CD62L - and CD4+, CD134+ T cells were detected only at disease peak, not during disease onset. PBM CD80 expression was significantly inhibited in CSA-treated animals, but increased in Dex-treated animals. PBM VLA-4 expression was unaffected by drug treatment. Both CSA and Dex inhibited CD62L shedding and CD134 expression on peripheral CD4+ T cells. These results identify quantitative, peripheral markers of disease activity and drug response.

Proinflammatory cytokines, adhesion molecules, and lymphocyte integrin expression in the internal jugular blood of migraine patients without aura assessed ictally

OBJECTIVE

The aim of the present research was to verify the levels of the soluble adhesion molecules sL- and sE-selectins, intercellular adhesion molecule (sICAM)-1, and vascular cell adhesion molecule-1 in serial samples of internal jugular venous blood taken from migraine patients without aura (MWoA) during attacks. The expression of leukocyte function antigen (LFA)-1 and very late activation antigen (VLA)-4 was also assessed on lymphocytes obtained from jugular venous blood. Levels of certain proinflammatory cytokines (tumor necrosis factor-alpha[TNF-alpha], interleukin-1beta[IL-1beta], IL-4, and IL-6) were also determined and correlated with those of adhesion molecules.

PATIENTS AND METHODS

Seven MWoA patients were admitted in the hospital during attacks and blood samples were taken immediately after catheter insertion, at 1, 2, and 4 hours after attack onset, and within 2 hours after its termination. The levels of adhesion molecules and cytokines were measured with ELISA method. The expression of LFA-1 and VLA-4 was assessed by flow cytometry.

RESULTS

A parallel transient increase of sICAM-1, TNF-alpha, and IL-6 was observed in the first 2 hours after attack onset compared with the time of catheter insertion (P < .0001, <.001, and <.003, respectively). The proportion of CD4+ and CD8+ T-cells expressing high levels of LFA-1 showed instead a progressive down-regulation with significantly lower percentages at 2 and 4 hours after attack onset (P < .01 and <.022, respectively). No variation in the percentage of VLA-4 expressing cells was observed at any time of the study.

CONCLUSIONS

The transient increase in sICAM-1 and TNF-alpha found in the internal jugular blood of MWoA patients assessed ictally can be induced by sensory neuropeptides released from activated trigeminal endings. The progressive decrease in sICAM-1 levels during attacks and the down-regulation of LFA-1 expression by lymphocytes could antagonize their transvascular migration, supporting the hypothesis of sterile inflammation in the dura mater during migraine attacks.

Microcirculation and Venous Ulcers: A Review

Recent histological and immunocytochemical analyses of venous leg ulcers suggest that lesions observed in the different stages of chronic venous insufficiency (CVI) may be related to an inflammatory process. This inflammatory process leads to fibrosclerotic remodeling of the skin and then to ulceration. The vascular network of the most superficial layers of the skin appears to be the target of the inflammatory reaction. Hemodynamic forces such as venous hypertension, circulatory stasis, and modified conditions of shear stress appear to play an important role in an inflammatory reaction accompanied by leukocyte activation which clinically leads to CVI: venous dermatitis and venous ulceration. The leukocyte activation is accompanied by the expression of integrins and by synthesis and release of many inflammatory molecules, including proteolytic enzymes, leukotrienes, prostaglandin, bradykinin, free oxygen radicals, cytokines, and possibly other classes of inflammatory mediators. The inflammatory reaction perpetuates itself, leading to liposclerotic skin and subcutaneous tissue remodeling. In light of the mechanisms of venous ulcer formation cited above, therapy in the future might be directed against leukocyte activation in order to diminish the magnitude of the inflammatory response. With this in mind, the attention of many investigators has been drawn to two different drugs with an anti-inflammatory effect: pentoxifylline and flavonoids.

Expression and function of homing-essential molecules and enhanced in vivo homing ability of human peripheral blood-derived hematopoietic progenitor cells after stimulation with stem cell factor

Hematopoietic stem cell (HSC) homing from blood to bone marrow is a multistep process involving rolling, extravasation, migration, and finally adhesion in the correct microenvironment. With view to the hematopoietic recovery after clinical stem cell transplantation, we investigated the effect of stem cell factor (SCF) on the expression and the adhesive function of the alpha4beta1 and alpha5beta1 integrins very-late antigen (VLA)-4 and VLA-5 on peripheral blood-derived hematopoietic progenitor cells. After SCF stimulation, the expression of VLA-4 and VLA-5 on CD34+/c-kit+ cells obtained from healthy donors increased from 54% to 90% and from 3% to 82%, respectively. For patient-derived cells, the increase was 67% to 90% and 12% to 46%. The proportion of mononuclear cells adhering to the fibronectin fragment CH296 increased by stimulation with SCF from 14% to 23%. Accordingly, functional studies showed an approximate 30% increase of adherent long-term culture-initiating cell. The improvement of the homing abilities of SCF-stimulated HSC was confirmed by transplantation into sublethally irradiated nonobese diabetic-scid/scid mice. Six weeks after the transplantation, in eight of eight animals receiving human HSC with the addition of SCF, a profound multilineage hematopoietic engraftment was detected, whereas in the control group receiving only HSC, none of eight animals engrafted. Our data provide the first in vivo evidence that stimulation with cytokines improves the homing ability of transplanted human hematopoietic progenitor cells.

Quantitative expression of the major homing integrins alphaL and alpha4 on human cord blood hematopoietic progenitor and stem cells

An increased traffic of hematopoietic progenitor cells (HPC) between bone marrow and peripheral organs is a peculiar feature of the allergic inflammation. It has been recently reported that the sublingual form of specific immunotherapy (SLIT) is capable of reducing such an increased HPC traffic. The House Dust Mite major antigen Der p1 has been proved to up-regulate the expression of the ICAM-1 and VCAM-1 endothelial addressins, supporting the view of an inflammatory cell recruiting at the site of allergen extract administration. In the present work we have investigated, by flow-cytometric techniques, the expression of the two major integrins CD11a (LFA-1) and CD49d (VLA-4) that are the homing receptor cognate for ICAM-1 and VCAM-1 on human cord blood CD34 hematopoietic progenitor and stem cells. Even if both the investigated molecules resulted detectable on CD34+ HPC surfaces, being the system redundant, the density of the cellular expression was significantly higher for CD49d (median value: 158) than CD11a (median value: 20.5), suggesting a preferential usage of the homing axis VLA-4/VCAM-1. Results consistency with outcomes of clinical trials that relate SLIT efficacy to allergen dosage is discussed.

High-throughput pharmacokinetics screen of VLA-4 antagonists by LC/MS/MS coupled with automated solid-phase extraction sample preparation

Automation of plasma sample preparation for pharmacokinetic studies on VLA-4 antagonists has been achieved by using 96-well format solid-phase extraction operated by Beckman Coulter Biomek 2000 liquid handling system. A Biomek 2000 robot is used to perform fully automated plasma sample preparation tasks that include serial dilution of standard solutions, pipetting plasma samples, addition of standard and internal standard solutions, performing solid-phase extraction (SPE) on Waters OASIS 96-well plates. This automated sample preparation process takes less than 2 h for a typical pharmacokinetic study, including 51 samples, 24 standards, 9 quality controls, and 3-6 dose checks with minimal manual intervention. Extensive validation has been made to ensure the accuracy and reliability of this method. A two-stage vacuum pressure controller has been incorporated in the program to improve SPE efficiency. This automated SPE sample preparation approach combined with liquid chromatography coupled with the high sensitivity and selectivity of tandem mass spectrometry (LC/MS)/MS has been successfully applied on both individual and cassette dosing for pharmacokinetic screening of a large number of VLA-4 antagonists with a limit of quantitation in the range of 1-5 ng/ml. Consequently, a significant throughput increase has been achieved along with an elimination of tedious labor and its consequential tendency to produce errors.

Assessment of selected adhesion molecules and lymphocyte subpopulations in children with IgA nephropathy

PURPOSE

The aim of the study was to assess the expression of selected adhesion molecules on mononuclear cells of peripheral blood and lymphocyte subpopulations in children with IgA nephropathy (IgAN).

MATERIAL AND METHODS

14 children with IgAN and 20 healthy controls were included in the study. Flow cytometry was used to determine the expression of such adhesion molecules as L selectin (CD62L), VLA-4 integrin (CD49d), intracellular molecule ICAM-1 (CD54) and cytotoxic lymphocyte molecule CTLA-4 (CD152), as well as the lymphocyte antigens: CD3, CD4, CD8, CD19, CD1656 (NK), CD4 and CD8 RO+ and RA+.

RESULTS

The findings revealed that the expression of the adhesion molecules VLA-4 and CTLA-4 did not differ from that of the healthy controls (p > 0.05). However, the expression of CD62L (L-selectin) was increased (p < 0.05). The expression of ICAM-1 was reduced, but not significantly, compared to the control group (p > 0.05). We found a decrease in the expression of NK cells (CD1656) and CD4/CD8 ratio, and an increase in CD8 cells (p < 0.05). In the group of 9/14 children, with proteinuria over 1.0 g/24 hours, a decreased expression of CD4 was additionally found (p < 0.05).

CONCLUSIONS

The children with IgAN show: 1. Changes in peripheral lymphocyte subpopulations involving an increase in CD8 cells and a decrease in CD1656(NK) cells, a reduction in the CD4/CD8 ratio, and additionally in cases with proteinuria a reduction in CD4 cell count, 2. Increased expression of L-selectin (CD62L) on peripheral blood mononuclear cells.

[Serum concentration of soluble vascular-cellular adhesion molecule-1 (VCAM-1) and expression of its receptor VLA-4 on the surface of peripheral blood and decidual lymphocytes of preeclamptic women]

INTRODUCTION

Vascular-cellular adhesion molecule-1 (VCAM-1) overexpression on the cells' surface is stimulated by pro-inflammatory cytokines, bacterial endotoxins, reactive oxygen species and lipid peroxides. In the serum also the soluble form of VCAM-1 (sVCAM-1) is present. The beta 1-integrin family molecule VLA-4 (CD49d) is natural ligand for VCAM-1. Increased concentrations of sVCAM-1 as well as overexpression of VLA-4 were observed during inflammatory reaction.

THE AIM

To study sVCAM-1 serum concentrations and CD49d+ subpopulations of peripheral blood and decidual lymphocytes of the 3rd trimester healthy and preeclamptic women.

MATERIALS AND METHODS

The study groups: n = 21 healthy pregnant women, n = 33 preeclamptic women (preeclampsia defined as blood pressure > 140/90 mmHg with proteinuria > 0.3 g/24 h). Clinical states of known pathogenesis which could possibly interfere with values of studied parameters were excluded. Exclusion criteria were also uterine contractions and premature rupture of amniotic membranes. Decidua was collected exclusively during elective caesarean sections. The sVCAM-1 concentration (ng/ml) was estimated using ELISA procedure, while percentage (%) of CD49d+ lymphocytes in the whole blood and homogenized decidual tissue, using flow cytometry. The results were presented as median value with 25% and 75% cut off values. Statistical analysis was performed with U-Mann-Whitney test (p < 0.05).

RESULTS

Preeclamptic women presented with increased sVCAM-1 serum concentrations (532.5 (400.0/605.0) ng/ml vs. 387.0 (320.0/416.5) ng/ml, p < 0.0005), increased (%) of CD49d+ peripheral blood (92.0 (88.0/96.0)% vs. 52.9 (47.5/55.8)%, p < 0.0000001) and CD49d+ decidual lymphocytes (88.0 (84.0/90.0)% vs. 80.5 (74.0/85.6)%, p < 0.05).

CONCLUSION

Described change suggest that immunological mechanisms similar to inflammatory reaction could be involved in pathogenesis of preeclampsia in peripheral blood as well as locally inside maternal-fetal interface.

Temporal variations of adhesion molecules and matrix metalloproteinases in the course of MS

Thirty patients with clinically isolated syndromes (CIS) were evaluated at the onset of neurological symptoms and when they developed clinically definite MS (CDMS). Surface expression of LFA-1alpha, VLA-4 and intercellular adhesion molecule-1 (ICAM-1) on PBMC and CSF cells was evaluated using flow cytometry. Serum and CSF concentrations of soluble vascular cell adhesion molecules-1 (VCAM-1), ICAM-1 and E-Selectin, as well as MMP-9 and MMP-2 serum concentrations were assayed using ELISA. Surface expression of LFA-1alpha and VLA-4 molecules on peripheral blood and CSF T cells and monocytes from CIS and CDMS was significantly increased compared with control subjects. Moreover, LFA-1alpha and VLA-4 expression was significantly higher in patients who developed CDMS compared with those with CIS. Similar changes were observed in the serum levels of MMP-9. Furthermore, patients with CIS and CDMS had significantly higher levels of CSF sVCAM and s-E-Selectin than control subjects. These data suggest that VLA-4, LFA-1alpha and MMP-9 play a leading role in the evolution of inflammatory demyelinating lesions in patients with CIS who develop CDMS.

Correlation between VLA-4 integrin and hematopoietic cell migration

To clarify the relationship between VLA-4 (CD49d) expression and hematopoietic cell migrating direction, mice were injected subcutaneously with diluted rhG-CSF for different times. The expressions of CD49d on Sca-1(+) cells were examined by flow cytometry. The relations between CD49d expression and Sca-1(+) cell enumerations were performed by statistical analysis. The results showed that with the administration of G-CSF, the expressions of CD49d in bone marrow (BM) and peripheral blood (PB) declined, meanwhile the number of Sca-1(+) cells in peripheral blood reached the peak in sharp contrast to BM nucleated cell number dropping on the seventh to ninth day. When CD49d expression rose again, the PB Sca-1(+) cells descended with the rising of BM nucleated cell number. In conclusion, VLA-4 mediates the hematopoietic cell adhesion to BM microenvironment. The regulation of CD49d expression may result in different migrating direction of hematopoietic cell between bone marrow and peripheral blood.

Extracellular matrix conditions T cells for adhesion to tissue interstitium

The activation and differentiation of peripheral blood T cells (PBT) are known to correlate with increased surface expression and adhesive capacity of beta(1) integrins, which mediate adhesion to the extracellular matrix (ECM). However, little is known about the regulation of integrin expression, affinity, and avidity on tissue T cells after they are embedded in the interstitial ECM. In this study we show that tissue T cells, freshly isolated from their residence in the interstitial ECM of the intestinal lamina propria, express a distinct subset of functionally active integrins that contribute to enhanced adhesion to purified collagen, fibronectin, and cell-derived ECM when compared with freshly isolated, short term activated, and long term cultured PBT. Furthermore, integrin usage is distinct between circulating and tissue-derived T cells, in that lamina propria T cells prefer to bind to collagen, while PBT lymphoblasts choose fibronectin when presented with a complex, three-dimensional, cell-derived matrix. To identify the extrinsic factors that regulate the conversion from a nonadhesive PBT to highly adhesive tissue T cell, we demonstrate that activation of PBT in the presence of fibronectin or collagen rapidly generates a surface integrin expression profile, an integrin usage pattern, and adhesive capacity mirroring that of a tissue T cell. These results indicate that the tissue ECM microenvironment instructs newly arrived T cells for further interactions with the underlying matrix and thereby imprints them with a signature tissue adhesive phenotype.