Constitutive Atg5 overexpression in mouse bone marrow endothelial progenitor cells improves experimental acute kidney injury.

BACKGROUND: Endothelial Progenitor Cells have been shown as effective tool in experimental AKI. Several pharmacological strategies for improving EPC-mediated AKI protection were identified in recent years. Aim of the current study was to analyze consequences of constitutive Atg5 activation in murine EPCs, utilized for AKI therapy. METHODS: Ischemic AKI was induced in male C57/Bl6N mice. Cultured murine EPCs were systemically injected post-ischemia, either natively or after Atg5 transfection (Adenovirus-based approach). Mice were analyzed 48 h and 6 weeks later. RESULTS: Both, native and transfected EPCs (EPCsAtg5) improved persisting kidney dysfunction at week 6, such effects were more pronounced after injecting EPCsAtg5. While matrix deposition and mesenchymal transdifferentiation of endothelial cells remained unaffected by cell therapy, EPCs, particularly EPCsAtg5 completely prevented the post-ischemic loss of peritubular capillaries. The cells finally augmented the augophagocytic flux in endothelial cells. CONCLUSIONS: Constitutive Atg5 activation augments AKI-protective effects of murine EPCs. The exact clinical consequences need to be determined.

Acute Kidney Injury-Associated Systemic Inflammation Is Aggravated in Insulin-Dependent Diabetes Mellitus.

BACKGROUND: Acute kidney injury (AKI) significantly worsens the prognosis of hospitalized patients. Diabetes mellitus (DM) affects a growing number of individuals in the western world. DM subjects are at a higher risk for acquiring AKI during the stay at the hospital. The current study intended to quantify serum levels of specific immunomodulatory cytokines in diabetic mice suffering from AKI. METHODS: DM was induced in male C57/Bl6N mice by systemic injections of beta cell-toxic streptozotocin. Animals underwent bilateral renal ischemia (45 min) 6 weeks later. RESULTS: Post-ischemic diabetic mice showed significantly differing serum concentrations of the majority of all analytes as compared to untreated controls and non-diabetic (post-ischemic) animals. CONCLUSIONS: Together, our data suggest DM-associated immune activation in AKI. One may suppose that inadequate stimulation of the humoral/cellular immune response potentially contributes to the higher ischemia susceptibility of the organ in DM.

Cytokine profiling in anti neutrophil cytoplasmic antibody-associated vasculitis: a cross-sectional cohort study.

ANCA-associated vasculitides (AAV) are severe diseases, potentially affecting lungs, kidney, and other organs. Nevertheless, risk profiling remains difficult. Aim of the current study was to analyze serological characteristics in AAV. The principal goal was to identify diagnostic markers that potentially allow a more sophisticated risk profiling in AAV. AAV subjects were recruited and evaluated for disease activity, disease stage, medication, and laboratory findings. Serum concentrations of the following parameters were measured: IL-1ß, IL-6, IL-17 A, IL-17 F, IL-21, IL-22, IL-23, TNF-α, sCD40L, IL-4, IL-10, IL-25, IL-31, IL-33, and INF-γ. A total number of 62 AAV subjects was included in the study (39 females; 23 males). Forty-five subjects were PR3+, 17 subjects showed ANCA specificity for MPO. The majority of all cytokines fell under the lower detection limit of the assay. Serum IL-10 was higher in both, AAV and SSc as compared to controls; it was also higher in early systemic AAV. Serum IL-33 was elevated in AAV and SSc; in AAV, higher levels were found in non-necrotizing GN and RTX untreated subjects. Serum CD40L was raised in AAV as well; higher concentrations were also found in PR3+ and MPO+ patients and early systemic, generalized, and refractory AAV. IL-10 may potentially serve as a marker of early systemic AAV. IL-33 may help to identify subjects with a higher risk for necrotizing GN in AAV.

Humoral and Cellular Patterns of Early Endothelial Progenitor Cells in Relation to the Cardiovascular Risk in Axial Spondylarthritis.

BACKGROUND: Spondylarthritis (SpA) significantly affects sacroiliac, intervertebral and peripheral joints. Patients with SpA suffer from increased cardiovascular risk (CVR). The endothelial progenitor cell (EPC) system critically perpetuates vascular repair. The aim of the study was to evaluate circulating EPCs in axial (ax)SpA with special attention on parameters of disease activity and CVR. METHODS: Disease activity and functional impairment were quantified in 50 axSpA patients by using standardized parameters (Bath ankylosing spondylitis disease activity index (BASDAI), C-reactive protein (CRP), finger-floor distance (FFD) and Ott' sign). Circulating EPCs and EPC regeneration were analyzed (fluorescence-activated cell sorting (FACS) and colony-forming unit (CFU) assay). Serum vasomodulatory mediators were quantified by enzyme-linked immunosorbent assay (ELISA). RESULTS: EPC colony numbers were lower in axSpA as compared to controls. Females displayed more colonies than males. In addition, fewer colonies were observed in smokers, in patients with a BASDAI of below 4 and in hypertension. Circulating CD133+/KDR+ cells did not differ between the groups. Follow-up analysis (33 months later) did not show any differences in gender, colony formation, CD133+/KDR+ cells or serum levels of vasomodulatory mediators if related to the categories of BASDAI, Ott' sign or FFD. CONCLUSIONS: EPC colony formation is significantly affected in axSpA with particularly low levels in males. EPC-related parameters do not allow predicting disease activity-related or functional parameters nor are they useful for CVR assessment in SpA.

[Acute Kidney Injury, AKI - Update 2018]. / Akute Nierenschädigung ­ Update 2018.

Acute Kidney Injury (AKI) remains a frequent and serious complication in hospitalized individuals worldwide. The current article will focus on three AKI-related aspects: prevention of contrast-Induced Nephropathy with sodium chloride vs. sodium bicarbonate (PRESERVE trial), kidney-related unwanted side effects of Sodium-Glucose co-Transporter-2-antagonists (SGLT-2-inhibitors), and the utilization of certain types of stem/progenitor cells for AKI therapy.

Safety profile of baroreflex activation therapy (NEO) in patients with resistant hypertension.

OBJECTIVE: Unlike safety data of baroreflex activation therapy device (Rheos), only few data of the currently used second device (Barostim neo) are available and little is reported about common side effects. METHODS: We prospectively analyzed patients with resistant hypertension treated with Barostim neo. A standardized interview regarding side effects of the therapy was performed in routine follow-up visits after device implantation in 42 patients to determine adverse events staged into three degrees. RESULTS: Within 6 months of baroreflex activation therapy, the office mean arterial blood pressure decreased from 169 ±â€Š27 to 148 ±â€Š29 mmHg systolic (P < 0.001), respectively, to 145 ±â€Š24 mmHg after 1 year (P < 0.001), whereas the number of prescribed antihypertensive classes decreased from 6.6 ±â€Š1.5 to 5.6 ±â€Š1.8 (P < 0.001). Adverse events were combination of the following field depending on the severity (I° mild: local discomfort, clinical observation only, no intervention indicated; II° moderate: medically significant such as occurrence of hypertensive crisis, syncope, arrhythmias; III° severe: life-threatening events or urgent medical intervention indicated). Adverse events I° were present in almost all patients (97.6%), and occurred mainly within first 6 months after device activation. Device-related events were most frequently and could be resolved by optimization of device parameters. Most procedure-related adverse events were directly related to the incision or anesthetic procedure. Adverse events II° occurred in 28.6% patients treated with Barostim neo, whereas patients' elevated individual risks might be potential triggers. Because of individual diversity of blood pressure response and the occurrence of adverse events, no standardization of parameters of implantable pulse generator could be found. By adapting the pulse generator settings individually, most of adverse events I° resolved without sequel. CONCLUSION: Though there are common side effects, Barostim neo significantly lowers blood pressure in resistant hypertension and provides an adequate safety profile. Regular patient visits are necessary to register side effects.

Management of cardiovascular risk factors in patients with ANCA-associated vasculitis.

OBJECTIVES: Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is accompanied by increased cardiovascular (CV) risk. Treatment of AAV patients includes the management of conventional CV risk factors, primarily hypertension and hypercholesterolemia, while lipoprotein(a) (LP(a)) is an emerging potential target. METHODS: We performed a multicenter, retrospective study in Germany. Patients were considered if they were between 18 and 90 years old and presented with AAV. Patients with arterial hypertension but no autoimmune disease were used as a control group (HTN reference group). RESULTS: Compared to the reference group (n = 52), CV disease burden was significantly greater in patients with AAV (n = 53). Hypercholesterolemia was also more common in the AAV patients (71.7% vs 46.2% for the HTN; P = .008). Lipoprotein(a) levels were elevated in both groups, with 11.3% and 17.3% of the AAV and HTN groups, respectively, displaying a level above 0.6 g/l (P = .083). Guideline-recommended targets for low-density lipoprotein cholesterol and blood pressure levels were rarely met. According to Kidney Disease: Improving Global Outcomes guidelines, 72.5% of the patients with AAV should have been taking statins and/or ezetimibe for treatment of hyperlipidemia; however, only 24.3% of them were receiving such treatment. Blood pressure below ≤140/90 mmHg was reached in 78.6% of the patients with chronic kidney disease. However, for patients with chronic kidney disease and an albumin excretion rate of >30 mg/day, the recommended blood pressure is ≤130/80 mmHg, a value that was not reached in 65% of the AAV patients. CONCLUSION: Patients with AAV are at high CV risk, but management of the associated risk factors is poor. In addition to improving the treatment of hypercholesterolemia and hypertension, lipoprotein(a) is a further potential target for reducing CV risk in individuals with AAV.

Prospective study on the potential of RAAS blockade to halt renal disease in Alport syndrome patients with heterozygous mutations.

BACKGROUND: Patients with autosomal or X-linked Alport syndrome (AS) with heterozygous mutations in type IV collagen genes have a 1-20 % risk of progressing to end-stage renal disease during their lifetime. We evaluated the long-term renal outcome of patients at risk of progressive disease (chronic kidney disease stages 1-4) with/without nephroprotective therapy. METHODS: This was a prospective, non-interventional, observational study which included data from a 4-year follow-up of AS patients with heterozygous mutations whose datasets had been included in an analysis of the 2010 database of the European Alport Registry. Using Kaplan-Meier estimates and logrank tests, we prospectively analyzed the updated datasets of 52 of these patients and 13 new datasets (patients added to the Registry after 2011). The effects of therapy, extrarenal symptoms and inheritance pattern on renal outcome were analyzed. RESULTS: The mean prospective follow-up was 46 ± 10 months, and the mean time on therapy was 8.4 ± 4.4 (median 7; range 2-18) years. The time from the appearance of the first symptom to diagnosis was 8.1 ± 14.2 (range 0-52) years. At the time of starting therapy, 5.4 % of patients had an estimated glomerular filtration rate of <60 ml/min, 67.6 % had proteinuria and 27.0 % had microalbuminuria. Therapeutic strategies included angiotensin-converting enzymer inhibitors (97.1 %), angiotensin receptor antagonists (1 patient), dual therapy (11.8 %) and statins (8.8 %). Among patients included in the prospective dataset, prevented the need for dialysis. Among new patients, no patient at risk for renal failure progressed to the next disease stage after 4 years follow-up; three patients even regressed to a lower stage during therapy. CONCLUSIONS: Treatment with blockers of the renin-angiotensin-aldosterone system prevents progressive renal failure in AS patients with heterozygous mutations in the genes causing AS. Considerable numbers of aging AS patients on dialysis may have heterozygous mutations in these genes (present in 1 % of total population) as underlying disease. Hence, greater alertness towards timely diagnosis and therapy has the potential to prevent progressive renal failure in most-if not all-AS patients with heterozygous mutations in the causal genes.

The significance and predictive value of free light chains in the urine of patients with chronic inflammatory rheumatic disease.

In patients with rheumatic diseases, reliable markers for determining disease activity are scarce. One potential parameter is the level of immunoglobulin free light chains (FLCs), which is known to be elevated in the blood of patients with certain rheumatic diseases. Few studies have quantified FLCs in urine, a convenient source of test sample, in patients with different rheumatic diseases. We carried out a retrospective analysis of patients with rheumatic disease attending the University hospital of Goettingen, Germany. Subjects were included if they had urine levels of both κ and λ FLCs available and did not have myeloma. Data regarding systemic inflammation and kidney function were recorded, and FLC levels were correlated with inflammatory markers. Of the 382 patients with rheumatic disease, 40.1 % had chronic polyarthritis, 21.2 % connective tissue disease, 18.6 % spondyloarthritis and 15.7 % vasculitis. Elevated levels of κ FLCs were found for 84 % of patients and elevated λ for 52.7 %. For the patients with rheumatoid arthritis, FLCs correlated with C-reactive protein (κ, r = 0.368, p < 0.001; λ, r = 0.398, p < 0.001) and erythrocyte sedimentation rate (κ, r = 0.692, p < 0.001; λ, r = 0.612, p < 0.001). Patients being treated with rituximab displayed FLC levels similar to those of the reference group. There were clear elevations in both κ and λ FLCs in patients with rheumatic disease, but not in κ/λ ratio. The correlation between FLCs and inflammatory markers in patients with rheumatoid arthritis demonstrates their potential for predicting disease activity.

Characterization and history of arterial hypertension leading to inpatient treatment.

BACKGROUND AND AIMS: Arterial hypertension is a major cause of death worldwide. For the most part, treatment for hypertension can be performed on an outpatient basis. However, some patients also require inpatient treatment, and the contributing factors for this remain unknown. Therefore, the primary objective of the present study was to determine which patient characteristics are associated with inpatient treatment for arterial hypertension. METHODS: Here, we conducted a mono-centric study of 103 hypertensive subjects, who were treated as inpatients in the Department of Nephrology and rheumatology of the university medical faculty of Göttingen. Therapies were not altered, and data collection was performed retrospectively. In addition to epidemiological information, the following data were recorded: patient symptoms, blood pressure (BP), anti-hypertensive therapy, and concomitant diseases (e.g., renal and cardiovascular conditions). RESULTS: Approximately half (53 %) of all subjects treated on an inpatient basis displayed elevated BP (>140/90 mmHg), while the remaining 47 % of patients showed normotensive readings (<140/90 mmHg) following admission. Moreover, 34 % of patients could be classified as therapy refractory. The main reasons for hospital admission were hypertension-related symptoms, including shortness of breath, dizziness, and headache (69 %). These patients were multi-morbid, with approximately 60 % displaying a secondary form of hypertension. Indeed, over half of the subjects showed renoparenchymatous forms of hypertension, and a large percentage of patients received hypertension-inducing drugs (32 %). Moreover, a high proportion of inpatients were treated with reserve antihypertensives, with the most commonly used drug being Moxonidin. CONCLUSION: The majority of hypertensive patients were hospitalized due to their clinical symptoms and not as a result of BP values alone. The high proportion of patients with secondary forms of hypertension or treated with BP-boosting medications was striking.

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.

Endothelial autophagy and Endothelial-to-Mesenchymal Transition (EndoMT) in eEPC treatment of ischemic AKI.

BACKGROUND: Autophagy enables cells to digest endogenous/exogenous waste products, thus potentially prolonging the cellular lifespan. Early endothelial progenitor cells (eEPCs) protect mice from ischemic acute kidney injury (AKI). The mid-term prognosis in AKI critically depends on vascular rarefication and interstitial fibrosis with the latter partly being induced by mesenchymal transdifferentiation of endothelial cells (EndoMT). This study aimed to determine the impact of eEPC preconditioning with different autophagy inducing agents [suberoylanilide hydroxamic acid (SAHA)/temsirolimus] in ischemic AKI. METHODS: Male C57/Bl6 N mice were subjected to bilateral renal ischemia (40 min). Animals were injected with either untreated, or SAHA- or temsirolimus-pretreated syngeneic murine eEPCs at the time of reperfusion. Mice were analyzed 48 h and 4 weeks later. In addition, cultured eEPCs were treated with transforming growth factor (TGF)-ß ± SAHA, autophagy (perinuclear LC3-II), and stress-induced premature senescence (SIPS-senescence-associated ß-galactosidase, SA-ß-Gal), and were evaluated 96 h later. RESULTS: Cultured eEPCs showed reduced perinuclear density of LC3-II + vesicles and elevated levels of SA-ß-Gal after treatment with TGF-ß alone, indicating impaired autophagy and aggravated SIPS. These effects were completely abrogated by SAHA. Systemic administration of either SAHA or tems pretreated eEPCs resulted in elevated intrarenal endothelial p62 at 48 h and 4 weeks, indicating stimulated endothelial autophagy. This effect was most pronounced after injection of SAHA-treated eEPCs. At 4 weeks endothelial expression of mesenchymal alpha-smooth muscle actin (αSMA) was reduced in animals receiving untreated and SAHA-pretreated cells. In addition, SAHA-treated cells reduced fibrosis at week 4. Tems in contrast aggravated EndoMT. Postischemic renal function declined after renal ischemia and remained unaffected in all experimental cell treatment groups. CONCLUSION: In ischemic AKI, intrarenal endothelial autophagy may be stabilized by systemic administration of pharmacologically preconditioned eEPCs. Early EPCs can reduce postischemic EndoMT and fibrosis in the mid-term. Autophagy induction in eEPCs either increases or decreases the mesenchymal properties of intrarenal endothelial cells, depending on the substance being used. Thus, endothelial autophagy induction in ischemic AKI, mediated by eEPCs is not a renoprotective event per se.

Acute kidney injury.

Acute kidney injury is a frequent and serious complication in hospitalized patients. Mortality rates have not substantially been decreased during the last 20 years. In most patients AKI results from transient renal hypoperfusion or ischemia. The consequences include tubular cell dysfunction/damage, inflammation of the organ, and post-ischemic microvasculopathy. The two latter events perpetuate kidney damage in AKI. Clinical manifestations result from diminished excretion of water, electrolytes, and endogenous / exogenous waste products. Patients are endangered by cardiovascular complications such as hypertension, heart failure, and arrhythmia. In addition, the whole organism may be affected by systemic toxification (uremia). The diagnostic approach in AKI involves several steps with renal biopsy inevitable in some patients. The current therapy focuses on preventing further kidney damage and on treatment of complications. Different pharmacological strategies have failed to significantly improve prognosis in AKI. If dialysis treatment becomes mandatory, intermittent and continuous renal replacement therapies are equally effective. Thus, new therapies are urgently needed in order to reduce short- and long-term outcome in AKI. In this respect, stem cell-based regimens may offer promising perspectives.

Collagen receptors integrin alpha2beta1 and discoidin domain receptor 1 regulate maturation of the glomerular basement membrane and loss of integrin alpha2beta1 delays kidney fibrosis in COL4A3 knockout mice.

Maturation of the glomerular basement membrane (GBM) is essential for maintaining the integrity of the renal filtration barrier. Impaired maturation causes proteinuria and renal fibrosis in the type IV collagen disease Alport syndrome. This study evaluates the role of collagen receptors in maturation of the GBM, matrix accumulation and renal fibrosis by using mice deficient for discoidin domain receptor 1 (DDR1), integrin subunit α2 (ITGA2), and type IV collagen α3 (COL4A3). Loss of both collagen receptors DDR1 and integrin α2ß1 delays maturation of the GBM: due to a porous GBM filtration barrier high molecular weight proteinuria that more than doubles between day 60 and day 100. Thereafter, maturation of the GBM causes proteinuria to drop down to one tenth until day 200. Proteinuria and the porous GBM cause accumulation of glomerular and tubulointerstitial matrix, which both decrease significantly after GBM-maturation until day 250. In parallel, in a disease with impaired GBM-maturation such as Alport syndrome, loss of integrin α2ß1 positively delays renal fibrosis: COL4A3(-/-)/ITGA2(-/-) double knockouts exhibited reduced proteinuria and urea nitrogen compared to COL4A3(-/-)/ITGA2(+/-) and COL4A3(-/-)/ITGA2(+/+) mice. The double knockouts lived 20% longer and showed less glomerular and tubulointerstitial extracellular matrix deposition than the COL4A3(-/-) Alport mice with normal integrin α2ß1 expression. Electron microscopy illustrated improvements in the glomerular basement membrane structure. MMP2, MMP9, MMP12 and TIMP1 were expressed at significantly higher levels (compared to wild-type mice) in COL4A3(-/-)/ITGA2(+/+) Alport mice, but not in COL4A3(+/+)/ITGA2(-/-) mice. In conclusion, the collagen receptors DDR1 and integrin α2ß1 contribute to regulate GBM-maturation and to control matrix accumulation. As demonstrated in the type IV collagen disease Alport syndrome, glomerular cell-matrix interactions via collagen receptors play an important role in the progression of renal fibrosis.

Fibrate treatment of eEOCs in murine AKI.

BACKGROUND: Early endothelial outgrowth cells (eEOCs) protect mice from acute kidney injury (AKI). Peroxisome proliferator-activated receptor-alpha (PPAR-α) has been shown to mediate renoprotective effects under different experimental conditions. The aim of the study was to investigate consequences of fibrate treatment of murine eEOCs in a cell-based therapeutic approach to AKI. METHODS: Male C57/Bl6N mice, subjected to unilateral renal ischemia (40 min) post-uninephrectomy, were systemically injected with 0.5 × 10(6) untreated or fenofibrate (FF 1, 5, 10 or 50 µm)/clofibrate (CF 1 mm) pretreated syngeneic murine eEOCs. Renal function and morphology were analyzed 48 h later. Cellular consequences of eEOC treatment with fibrates (FF 1, 5, 10, 50 µm, CF 1 mm) were evaluated using different in vitro assays (direct cell migration, apoptosis/necrosis, ELISA studies). RESULTS: Administration of untreated eEOCs did not protect mice from AKI. Injection of eEOCs treated with CF (1 mm) or FF 50 µm did not result in any protection from ischemia-induced renal dysfunction. In vitro analysis showed reduced cellular secretion of vasoprotective vascular endothelial growth factor (VEGF), an effect that was more pronounced with CF; FF increased percentages of apoptotic/necrotic eEOCs, and both substances failed to stimulate migration of cultured cells. With lower FF concentrations (1, 5, 10 µm) cell survival was increased and 10 µm FF stimulated VEGF secretion. In vivo administration of FF-treated eEOCs (10 µm) also did not result in any renoprotective effect. CONCLUSION: PPAR-α activation using fibrates does not stimulate renoprotective effects of syngeneic murine eEOCs in ischemic AKI, although lower fibrate concentrations significantly activate eEOCs in vitro.

Antifibrotic, nephroprotective effects of paricalcitol versus calcitriol on top of ACE-inhibitor therapy in the COL4A3 knockout mouse model for progressive renal fibrosis.

BACKGROUND: The COL4A3-/- mouse serves as animal model for progressive renal fibrosis. Using this animal model, the present study investigates the nephroprotective effects of Paricalcitol versus Calcitriol alone and on top of ACE-inhibitor therapy. METHODS: Eighty six mice were divided into six groups: (PC) with Paricalcitol 0.1 mcg/kg, (CA) Calcitriol 0.03 mcg/kg (dose equipotent), (PLAC) vehicle 0.1 mL i.p. five times per week, (ACE + PC) Paricalcitol plus Ramipril, (ACE + CA) Calcitriol plus Ramipril and (ACE + PLAC) vehicle plus Ramipril 10 mg/kg/day p.o. ACE therapy started pre-emptively in Week 4, PC/CA therapy was initiated in 6-week-old animals with ongoing renal fibrosis and lasted for 8 weeks. Four to six animals were sacrificed after 9.5 weeks and kidneys were further investigated using histological, immunohistological and Western-blot techniques. Survival until end-stage renal failure was determined in the remaining animals. RESULTS: PC, but not CA, prolonged lifespan until renal failure by 13% compared with untreated controls (P = 0.069). ACE-inhibition prolonged lifespan by >50%. Added on top of ACE inhibition, ACE + PC (but not ACE + CA) even further prolonged lifespan by additional 18.0% (P < 0.01 versus ACE + PLAC) and improved renal function (blood urea nitrogen; P < 0.05 versus ACE + CA). Accumulation of extracellular matrix and renal scarring was decreased in PC and ACE + PC-treated mice. CONCLUSIONS: The present study demonstrated a substantial nephroprotective and antifibrotic effect of the vitamin D-receptor activator Paricalcitol on top of early ACE inhibition in the COL4A3-/- model of progressive kidney fibrosis. The synergistic effect of Paricalcitol on top of RAAS-blockade might as well be valuable in other chronic kidney diseases.

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.

Therapeutic apheresis in pediatric patients with acute CNS inflammatory demyelinating disease.

BACKGROUND/AIMS: In adults, plasma exchange (PE) has been shown to be an efficient treatment for severe relapses of acute inflammatory CNS demyelinating diseases. The aim of this study was to evaluate the safety and efficacy of this treatment in pediatric patients. METHODS: We retrospectively analyzed a single-center cohort of pediatric patients with inflammatory CNS demyelinating disorders who underwent apheresis between 2007 and 2011. RESULTS: Ten patients (mean age: 11.6 ± 3.4 years) with an acute relapse of multiple sclerosis (n = 5), neuromyelitis optica (n = 2) or acute disseminated encephalomyelitis were included. All received methylprednisolone prior to treatment with either PE (n = 5) or immunoadsorption (n = 5). Apheresis-related side effects were either self-limiting or easily managed. EDSS (Expanded Disability Status Scale) improved in 7 of 8 patients during apheresis and in all patients within 30 days from a median of 7.5 to 1 (p < 0.01). The visual acuity initially worsened during the procedure in 3 of 7 affected eyes (mean 0.09), but improved in all at follow-up (mean: 0.5; p = 0.008). CONCLUSIONS: Apheresis was well tolerated and associated with a favorable outcome in all pediatric patients similar to reports in adults.

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-ß 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.