Elvira Henze

Determination of peroxides in saliva-kinetics of peroxide release into saliva during home-bleaching with Whitestrips® and Vivastyle®

Aim of the study was to determine peroxides in saliva, released during bleaching procedures. Upper incisors of five subjects were bleached with Whitestrips (5% H2O2) and Vivastyle (10% carbamide peroxide, tray charged with 225mg) for 30min, each on different days. Saliva was collected before and during the whole period of bleaching at different intervals. The amount of peroxide in the salivary samples was assessed with peroxidase, phenol and 4-aminoantipyrin in a photometric assay. Additionally the amount of peroxides in the bleaching material was determined before and after the bleaching, so that the peroxide release into saliva could be balanced. The amount of peroxides released into saliva was related to the bleaching system and only partially influenced by the individual salivary flow rate. Bleaching with Vivastyle led to lower release of peroxides into saliva compared to Whitestrips (Vivastyle: 0.8+/-0.17mg; Whitestrips: 1.5+/-0.84mg). Salivary flow rate was not correlated to release of peroxides from the bleaching products. It can be concluded that the enzymatic method adopting 4-aminoantipyrin and peroxidase is valid for the determination of peroxides in saliva. Furthermore distinctly more peroxides are released into the oral cavity from Whitestrips than from trays charged with Vivastyle .

LDL lipid apheresis rapidly increases peripheral endothelial progenitor cell competence.

Endothelial progenitor cells (EPCs) have been shown to promote neovascularization under physiologic and pathologic conditions. Statins have been documented to increase the total number of circulating EPCs in long‐term treated patients. Lipid apheresis is used to treat patient with refractory hyperlipidemia. The aim of our study was to evaluate whether lipid apheresis is associated with EPC mobilization.

Angiopoietin-2 modulates eEOC-mediated renoprotection in AKI in a dose-dependent manner.

BACKGROUND Early endothelial outgrowth cells (eEOCs) significantly protect mice from acute kidney injury (AKI). Angiopoietin-2 (Ang-2) has been shown to be critically involved in vascular repair and homeostasis. The aim of this study was to investigate consequences of Ang-2 treatment of syngeneic murine eEOCs in a cell-based therapeutic approach for AKI. METHODS Male 8- to 12-week-old C57/Bl6N mice, subjected to unilateral renal ischemia (40 minutes) postuninephrectomy were systemically injected with 0.5 × 10(6) untreated or Ang-2-pretreated syngeneic murine eEOCs. Renal function and morphology were analyzed 48 hours later. Cellular consequences of eEOC treatment with Ang-2 were evaluated using different in vitro assays (direct and indirect migration, apoptosis/necrosis, ELISA studies). RESULTS Administration of untreated eEOCs did not protect mice from AKI. Ang-2 dose-dependently modulated cell effects in AKI. While incubating the cells at a concentration of 200 ng/mL (1 hour) did not have any effect on renal function, doubling the concentration (400 ng/mL) resulted in significant renoprotection of cell-injected mice. With 800 ng/mL, cell injection dramatically worsened renal function of treated animals. In vitro analysis showed significantly accelerated migration of cultured mature endothelial cells after incubation with supernatant from Ang-2-treated eEOCs (200 and 400 ng/mL). These effects were most pronounced with 400 mg/mL. In addition, Ang-2 promoted survival of eEOCs. Cellular releases of VEGF and IL-6 were decreased by Ang-2, while TGF-β levels in the medium of Ang-2-stimulated eEOCs were not different from those in untreated cells. CONCLUSION Ang-2 acts as modulator of eEOCs in AKI. The migration analysis indicates that the Ang-2 significantly alters indirect (paracrine) activity of eEOCs, thus promoting renoprotection in a dose-dependent manner.

eEOC-mediated modulation of endothelial autophagy, senescence, and EnMT in murine diabetic nephropathy.

Diabetic nephropathy is the most frequent single cause of end-stage renal disease in our society. Microvascular damage is a key event in diabetes-associated organ malfunction. Early endothelial outgrowth cells (eEOCs) act protective in murine acute kidney injury. The aim of the present study was to analyze consequences of eEOC treatment of murine diabetic nephropathy with special attention on endothelial-to-mesenchymal transdifferentiation, autophagy, senescence, and apoptosis. Male C57/Bl6N mice (8-12 wk old) were treated with streptozotocin for 5 consecutive days. Animals were injected with untreated or bone morphogenetic protein (BMP)-5-pretreated syngeneic murine eEOCs on days 2 and 5 after the last streptozotocin administration. Four, eight, and twelve weeks later, animals were analyzed for renal function, proteinuria, interstitial fibrosis, endothelial-to-mesenchymal transition, endothelial autophagy, and senescence. In addition, cultured mature murine endothelial cells were investigated for autophagy, senescence, and apoptosis in the presence of glycated collagen. Diabetes-associated renal dysfunction (4 and 8 wk) and proteinuria (8 wk) were partly preserved by systemic cell treatment. At 8 wk, antiproteinuric effects were even more pronounced after the injection of BMP-5-pretreated cells. The latter also decreased mesenchymal transdifferentiation of the endothelium. At 8 wk, intrarenal endothelial autophagy (BMP-5-treated cells) and senescence (native and BMP-5-treated cells) were reduced. Autophagy and senescence in/of cultured mature endothelial cells were dramatically reduced by eEOC supernatant (native and BMP-5). Endothelial apoptosis decreased after incubation with eEOC medium (native and BMP-5). eEOCs act protective in diabetic nephropathy, and such effects are significantly stimulated by BMP-5. The cells modulate endothelial senescence, autophagy, and apoptosis in a protective manner. Thus, the renal endothelium could serve as a therapeutic target in diabetes-associated kidney dysfunction.

Endothelial progenitor cells in systemic lupus erythematosus.

BACKGROUND AND AIM Systemic lupus erythematosus (SLE) is an autoimmune-mediated disease, characterized by inflammation of small arteries and arterioles. Patients with SLE suffer from a 17-fold higher risk for developing atherosclerosis than healthy individuals. Endothelial progenitor cells (EPCs) have been shown to be critically involved in microvascular repair under both physiological and pathological conditions. The aim of the present study was to analyze EPC regeneration and mobilization in SLE patients with variable disease activity and undergoing different treatment regimens. METHODS Forty-eight patients with SLE were analyzed. Healthy, age- and sex-matched individuals served as controls. Total circulating EPCs were enumerated by FACS analysis, and regenerative activity of the cells was analyzed by a colony-forming assay. Vasomodulatory mediators were quantified by 
ELISA. RESULTS SLE patients did not show lower or higher percentages of total circulating EPCs, but they displayed significantly lower colony numbers as compared with healthy controls, indicating impaired EPC regeneration and mobilization. Low and high disease activity were associated with decreased EPC regeneration, while moderate disease activity was not. Hypertension and, to some extent, renal involvement were associated with reduced colony formation. Patients not receiving hydroxychloroquine (HCQ) treatment and those undergoing glucocorticoid therapy showed impaired EPC regeneration as well. CONCLUSIONS SLE patients suffer from both defective regeneration and mobilization of EPCs. Such an impairment of the EPC system, as one key regulatory element in the process of vasorepair, could potentially promote microvascular damage in SLE. Long-term glucocorticoid therapy may further suppress the EPC system, while HCQ may prevent regeneration of the cells.

Endothelial-to-Mesenchymal Transition and endothelial cilia in EPC-mediated postischemic kidney protection

Renal ischemia induces peritubular capillary rarefication and fibrosis, with the latter partly resulting from the endothelial-to-mesenchymal transition (EndoMT). Endothelial cilia transmit blood flow-associated forces into the cell. Early endothelial progenitor cells (eEPCs) have been shown to protect mice from acute kidney injury in the short term. The aim of the present study was to analyze midterm consequences of eEPC treatment in the context of endothelial cilia and the EndoMT. Male C57/Bl6N mice were subjected to unilateral renal ischemia postuninephrectomy. Syngeneic murine eEPCs were systemically injected at the time of reperfusion. Animals were investigated 1, 4, and 6 wk later. Cultured mature endothelial cells were exposed to a variable flow with versus without eEPC supernatant incubation. Systemically injected eEPCs reduced serum creatinine levels at week 1 (35 and 45 min) and week 4 (45 min). Interstitial fibrosis was significantly diminished by cell treatment at all time points as well. The EndoMT was less pronounced at week 4 (35 min) and week 6 (45 min). eEPC supernatant reduced α-smooth muscle actin expression and α-tubulin abundance in flow-treated cultured mature endothelial cells, and percentages of cilium-positive cells increased. The loss of peritubular capillaries was prevented by eEPCs. Intrarenal endothelial α-tubulin decreased postischemia and was further reduced by eEPC administration. We conclude that eEPCs are capable of reorganizing the endothelial cytoskeleton in an indirect manner, ultimately resulting in stabilization of the endothelial ciliome. The investigation indicates an antimesenchymal role of endothelial cilia in the process of postischemic tissue fibrosis/EndoMT.

Impairment and Differential Expression of PR3 and MPO on Peripheral Myelomonocytic Cells with Endothelial Properties in Granulomatosis with Polyangiitis

Background. Granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) are autoimmune-mediated diseases characterized by vasculitic inflammation of respiratory tract and kidneys. Clinical observations indicated a strong association between disease activity and serum levels of certain types of autoantibodies (antineutrophil cytoplasm antibodies with cytoplasmic [cANCA in GPA] or perinuclear [pAN CA in MPA] immunofluorescence). Pathologically, both diseases are characterized by severe microvascular endothelial cell damage. Early endothelial outgrowth cells (eEOCs) have been shown to be critically involved in neovascularization under both physiological and pathological condition. Objectives. The principal aims of our study were (i) to analyze the regenerative activity of the eEOC system and (ii) to determine mPR3 and MPO expression in myelo monocytic cells with endothelial characteristics in GPA and MPA patients. Methods. In 27 GPA and 10 MPA patients, regenerative activity blood-derived eEOCs were analyzed using a culture-forming assay. Flk-1+, CD133+/Flk-1+, mPR3+, and Flk-1+/mPR3+ myelomonocytic cells were quantified by FACS analysis. Serum levels of Angiopoietin-1 and TNF-α were measured by ELISA. Results. We found reduced eEOC regeneration, accompanied by lower serum levels of Angiopoietin-1 in GPA patients as compared to healthy controls. In addition, the total numbers of Flk-1+ myelomonocytic cells in the peripheral circulation were decreased. Membrane PR3 expression was significantly higher in total as well as in Flk-1+ myelomonocytic cells. Expression of MPO was not different between the groups. Conclusions. These data suggest impairment of the eEOC system and a possible role for PR3 in this process in patients suffering from GPA.

Dynamics of pulse wave velocity and vascular augmentation index in association with endothelial progenitor cells in SLE

Patients with SLE display a significantly higher cardiovascular risk (CVR). Pulse wave velocity (PWV) has meanwhile been established as a reliable parameter of end-organ damage. Endothelial progenitor cells (EPCs) are critically involved in vascular repair under both physiological and pathological conditions. The aim of the study was to analyse PWV and the Vascular Augmentation Index (VAI) and EPC numbers/regeneration in a well-defined German SLE cohort. Thirty patients were included. Only two individuals displayed a PWV of above 10 m/s. There was no correlation between PWV percentiles and disease activity as reflected by the SLE Disease Activity Index. Neither EPC colonies nor percentages of circulating EPCs (CD133+/KDR+) correlated with PWV/VAI in a positive or negative manner. Thus, it can be questioned whether pulse wave analysis and/or EPC proliferation and circulating cell numbers are truly useful for CVR assessment in SLE.