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"Menne, Jan"
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Calcium dobesilate reduces VEGF signaling by interfering with heparan sulfate binding site and protects from vascular complications in diabetic mice
2020
Inhibiting vascular endothelial growth factor (VEGF) is a therapeutic option in diabetic microangiopathy. However, VEGF is needed at physiological concentrations to maintain glomerular integrity; complete VEGF blockade has deleterious effects on glomerular structure and function. Anti-VEGF therapy in diabetes raises the challenge of reducing VEGF-induced pathology without accelerating endothelial cell injury. Heparan sulfate (HS) act as a co-receptor for VEGF. Calcium dobesilate (CaD) is a small molecule with vasoprotective properties that has been used for the treatment of diabetic microangiopathy. Preliminary evidence suggests that CaD interferes with HS binding sites of fibroblast growth factor. We therefore tested the hypotheses that (1) CaD inhibits VEGF signaling in endothelial cells, (2) that this effect is mediated via interference between CaD and HS, and (3) that CaD ameliorates diabetic nephropathy in a streptozotocin-induced diabetic mouse model by VEGF inhibition. We found that CaD significantly inhibited VEGF165-induced endothelial cell migration, proliferation, and permeability. CaD significantly inhibited VEGF165-induced phosphorylation of VEGFR-2 and suppressed the activity of VEGFR-2 mediated signaling cascades. The effects of CaD in vitro were abrogated by heparin, suggesting the involvement of heparin-like domain in the interaction with CaD. In addition, VEGF121, an isoform which does not bind to heparin, was not inhibited by CaD. Using the proximity ligation approach, we detected inhibition of interaction in situ between HS and VEGF and between VEGF and VEGFR-2. Moreover, CaD reduced VEGF signaling in mice diabetic kidneys and ameliorated diabetic nephropathy and neuropathy, suggesting CaD as a VEGF inhibitor without the negative effects of complete VEGF blockade and therefore could be useful as a strategy in treating diabetic nephropathy.
Journal Article
Outcomes in patients with atypical hemolytic uremic syndrome treated with eculizumab in a long-term observational study
by
Delmas, Yahsou
,
Greenbaum, Larry A.
,
Sheerin, Neil S.
in
Adolescent
,
Adult
,
Alternate complement pathway
2019
Background
There are limited long-term outcome data in eculizumab-treated patients with atypical hemolytic uremic syndrome (aHUS). We report final results from the largest prospective, observational, multicenter study of patients with aHUS treated with eculizumab.
Methods
Patients with aHUS who participated in any of five parent eculizumab trials and received at least one eculizumab infusion were eligible for enrollment in a long-term follow-up study. Rates of thrombotic microangiopathy (TMA) manifestations off versus on eculizumab were evaluated. Additional endpoints included change from baseline estimated glomerular filtration rate (eGFR), long-term renal outcomes, and serious targeted treatment-emergent adverse events.
Results
Among 93 patients (0–80 years of age), 51 (55%) remained on eculizumab and 42 (45%) discontinued; for those who discontinued, 21 (50%) reinitiated therapy. Patients who reinitiated eculizumab had similar baseline clinical characteristics to patients who remained on eculizumab, with higher likelihood of genetic/autoimmune complement abnormalities, more prior TMAs, and longer disease course versus those who did not reinitiate. Mean eGFR improved rapidly and remained stable for up to 6 years on eculizumab. In patients who discontinued, there was a trend toward decreasing renal function over time from discontinuation. Additionally, off-treatment TMA manifestation rates were higher in those aged < 18 years at diagnosis, with identified genetic/autoimmune complement abnormalities, or history of multiple TMAs prior to eculizumab initiation. The safety profile was consistent with previous studies. Three definite and one possible meningococcal infections related to eculizumab were reported and resolved with treatment. Three deaths unrelated to eculizumab were reported.
Conclusions
The current study confirms the efficacy and safety of eculizumab in aHUS, particularly with regard to long-term renal function and TMA events. Pediatric age at disease onset and presence of genetic or autoimmune complement abnormalities are risk factors for TMA events off treatment. Overall, patients who discontinue eculizumab may be at risk for additional TMA manifestations and renal function decreases. Discontinuation of eculizumab, with careful monitoring, is an option in select patients with consideration of patient preference, organ function normalization, and risk factors for relapse, including mutational analysis, age of onset, and history of multiple TMA episodes.
Trial registration
ClinicalTrials.gov
NCT01522170
, January 31, 2012.
Journal Article
Acute kidney injury and adverse renal events in patients receiving SGLT2-inhibitors: A systematic review and meta-analysis
by
Dumann, Eva
,
Menne, Jan
,
Haller, Hermann
in
Acute Kidney Injury - drug therapy
,
Analysis
,
Benzhydryl Compounds - therapeutic use
2019
Sodium-glucose cotransporter-2 inhibitors (SGLT2is) represent a new class of oral hypoglycemic agents used in the treatment of type 2 diabetes mellitus. They have a positive effect on the progression of chronic kidney disease, but there is a concern that they might cause acute kidney injury (AKI).
We conducted a systematic review and meta-analysis of the effect of SGLT2is on renal adverse events (AEs) in randomized controlled trials and controlled observational studies. PubMed, EMBASE, Cochrane library, and ClinicalTrials.gov were searched without date restriction until 27 September 2019. Data extraction was performed using a standardized data form, and any discrepancies were resolved by consensus. One hundred and twelve randomized trials (n = 96,722) and 4 observational studies with 5 cohorts (n = 83,934) with a minimum follow-up of 12 weeks that provided information on at least 1 adverse renal outcome (AKI, combined renal AE, or hypovolemia-related events) were included. In 30 trials, 410 serious AEs due to AKI were reported. SGLT2is reduced the odds of suffering AKI by 36% (odds ratio [OR] 0.64 [95% confidence interval (CI) 0.53-0.78], p < 0.001). A total of 1,089 AKI events of any severity (AEs and serious AEs [SAEs]) were published in 41 trials (OR 0.75 [95% CI 0.66-0.84], p < 0.001). Empagliflozin, dapagliflozin, and canagliflozin had a comparable benefit on the SAE and AE rate. AEs related to hypovolemia were more commonly reported in SGLT2i-treated patients (OR 1.20 [95% CI 1.10-1.31], p < 0.001). In the observational studies, 777 AKI events were reported. The odds of suffering AKI were reduced in patients receiving SGLT2is (OR 0.40 [95% CI 0.33-0.48], p < 0.001). Limitations of this study are the reliance on nonadjudicated safety endpoints, discrepant inclusion criteria and baseline hypoglycemic therapy between studies, inconsistent definitions of renal AEs and hypovolemia, varying follow-up times in different studies, and a lack of information on the severity of AKI (stages I-III).
SGLT2is reduced the odds of suffering AKI with and without hospitalization in randomized trials and the real-world setting, despite the fact that more AEs related to hypovolemia are reported.
Journal Article
Incidence of acquired thrombotic thrombocytopenic purpura in Germany: a hospital level study
2019
Background
Acquired thrombotic thrombocytopenic Purpura (aTTP) is a life-threatening ultra-orphan disease with a reported annual incidence between 1.5 and 6.0 cases per million in Europe and mainly affecting otherwise young and healthy adults aged 40 years on average. The goal of this study was to assess the incidence of aTTP in Germany.
Methods
A systematic review was performed to determine the published evidence on the aTTP epidemiology in Germany. To obtain additional evidence on the proportion of aTTP cases within the national Thrombotic Microangiopathy (TMA) population a hospital-level study was performed, using a retrospective data collection approach. Diagnosis of aTTP was confirmed if ADAMTS13 level were < 10% and/or the medical records explicitly mentioned aTTP diagnosis. The aggregated hospital data were then projected to the national level using logistic regression techniques.
Results
The systematic literature search did not provide incidence estimates of aTTP in Germany. Eight centers (≈27% of the top 30 TMA hospitals) delivered data according to a predefined data collection form. On average (year 2014–2016) a total number of 172 aTTP episodes per year was projected (95% confidence interval [95%CI]: 132–212). The majority were newly diagnosed aTTP cases (
n
= 121; 95%CI: 105–129), and 51 were recurrent aTTP cases (95%CI: 27–84). The average annual projected incidence (year 2014–2016) of aTTP episodes was 2.10 per million inhabitants in Germany (95%CI: 1.60–2.58).
Conclusions
The determined annual incidence of newly diagnosed aTTP cases and the overall annual incidence of aTTP episodes in Germany confirm the ultra-orphan character of aTTP. An external validation against international registries (France, UK and USA) shows that our findings are quite comparable with those international incidence rates.
Journal Article
Correction: Calcium dobesilate reduces VEGF signaling by interfering with heparan sulfate binding site and protects from vascular complications in diabetic mice
by
Njau, Florence
,
Bollin, Robin
,
Schenk, Heiko
in
Protection and preservation
,
Sulfates
,
Vascular endothelial growth factor
2020
[This corrects the article DOI: 10.1371/journal.pone.0218494.].
Journal Article
Loss of Caveolae, Vascular Dysfunction, and Pulmonary Defects in Caveolin-1 Gene-Disrupted Mice
by
Lohn, Matthias
,
Schedl, Andreas
,
Lindschau, Carsten
in
Albumins - cerebrospinal fluid
,
Animals
,
Aorta - physiology
2001
Caveolae are plasma membrane invaginations that may play an important role in numerous cellular processes including transport, signaling, and tumor suppression. By targeted disruption of caveolin-1, the main protein component of caveolae, we generated mice that lacked caveolae. The absence of this organelle impaired nitric oxide and calcium signaling in the cardiovascular system, causing aberrations in endothelium-dependent relaxation, contractility, and maintenance of myogenic tone. In addition, the lungs of knockout animals displayed thickening of alveolar septa caused by uncontrolled endothelial cell proliferation and fibrosis, resulting in severe physical limitations in caveolin-1-disrupted mice. Thus, caveolin-1 and caveolae play a fundamental role in organizing multiple signaling pathways in the cell.
Journal Article
Podocytic PKC-Alpha Is Regulated in Murine and Human Diabetes and Mediates Nephrin Endocytosis
2010
Microalbuminuria is an early lesion during the development of diabetic nephropathy. The loss of high molecular weight proteins in the urine is usually associated with decreased expression of slit diaphragm proteins. Nephrin, is the major component of the glomerular slit diaphragm and loss of nephrin has been well described in rodent models of experimental diabetes as well as in human diabetic nephropathy.
In this manuscript we analyzed the role of PKC-alpha (PKCalpha) on endocytosis of nephrin in podocytes. We found that treatment of diabetic mice with a PKCalpha-inhibitor (GO6976) leads to preserved nephrin expression and reduced proteinuria. In vitro, we found that high glucose stimulation would induce PKCalpha protein expression in murine and human podocytes. We can demonstrate that PKCalpha mediates nephrin endocytosis in podocytes and that overexpression of PKCalpha leads to an augmented endocytosis response. After PKC-activation, we demonstrate an inducible association of PKCalpha, PICK1 and nephrin in podocytes. Moreover, we can demonstrate a strong induction of PKCalpha in podocytes of patients with diabetic nephropathy.
We therefore conclude that activation of PKCalpha is a pathomechanistic key event during the development of diabetic nephropathy. PKCalpha is involved in reduction of nephrin surface expression and therefore PKCalpha inhibition might be a novel target molecule for anti-proteinuric therapy.
Journal Article
Deletion of Protein Kinase C-β Isoform In Vivo Reduces Renal Hypertrophy but Not Albuminuria in the Streptozotocin-Induced Diabetic Mouse Model
by
Joon-Keun Park
,
Torsten Kirsch
,
Faikah Gueler
in
Albuminuria - genetics
,
Albuminuria - prevention & control
,
Animals
2007
Deletion of Protein Kinase C-β Isoform In Vivo Reduces Renal Hypertrophy but Not Albuminuria in the Streptozotocin-Induced
Diabetic Mouse Model
Matthias Meier ,
Joon-Keun Park ,
Daniel Overheu ,
Torsten Kirsch ,
Carsten Lindschau ,
Faikah Gueler ,
Michael Leitges ,
Jan Menne and
Hermann Haller
Department of Nephrology, Hannover Medical School, Hannover, Germany
Address correspondence and reprint requests to Matthias Meier, MD, Hannover Medical School, Carl-Neuberg Str. 1, 30625 Hannover,
Germany. E-mail: meier.matthias{at}mh-hannover.de
Abstract
The protein kinase C (PKC)-β isoform has been implicated to play a pivotal role in the development of diabetic kidney disease.
We tested this hypothesis by inducing diabetic nephropathy in PKC-β–deficient (PKC-β −/− ) mice. We studied nondiabetic and streptozotocin-induced diabetic PKC-β −/− mice compared with appropriate 129/SV wild-type mice. After 8 weeks of diabetes, the high-glucose–induced renal and glomerular
hypertrophy, as well as the increased expression of extracellular matrix proteins such as collagen and fibronectin, was reduced
in PKC-β −/− mice. Furthermore, the high-glucose–induced expression of the profibrotic cytokine transforming growth factor (TGF)-β1 and
connective tissue growth factor were significantly diminished in the diabetic PKC-β −/− mice compared with diabetic wild-type mice, suggesting a role of the PKC-β isoform in the regulation of renal hypertrophy.
Notably, increased urinary albumin-to-creatinine ratio persisted in the diabetic PKC-β −/− mice. The loss of the basement membrane proteoglycan perlecan and the podocyte protein nephrin in the diabetic state was
not prevented in the PKC-β −/− mice as previously demonstrated in the nonalbuminuric diabetic PKC-α −/− mice. In summary, the differential effects of PKC-β deficiency on diabetes-induced renal hypertrophy and albuminuria suggest
that PKC-β contributes to high-glucose–induced TGF-β1 expression and renal fibrosis, whereas perlecan, as well as nephrin,
expression and albuminuria is regulated by other signaling pathways.
CTGF, connective tissue growth factor
PKC, protein kinase C
STZ, streptozotocin
TGF, transforming growth factor
VEGF, vascular endothelial growth factor
WT1, Wilms’ tumor suppressor
Footnotes
M.M. and J.-K.P. contributed equally to this work.
The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore
be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
Accepted November 6, 2006.
Received June 30, 2006.
DIABETES
Journal Article
Probing depth is an independent risk factor for HbA1c levels in diabetic patients under physical training: a cross-sectional pilot-study
by
Hillebrecht, Andree
,
Zeissler, Sven
,
Grischke, Jasmin
in
Analysis
,
Clinical oral healthcare research
,
Dentistry
2018
Background
This cross-sectional study investigates the potential association between active periodontal disease and high HbA1c levels in type-2-diabetes mellitus subjects under physical training.
Methods
Women and men with a diagnosis of non-insulin-dependent diabetes mellitus and ongoing physical and an ongoing exercise program were included. Periodontal conditions were assessed according to the CDC-AAP case definitions. Venous blood samples were collected for the quantitative analysis of HbA1c. Associations between the variables were examined with univariate and multivariate regression models.
Results
Forty-four subjects with a mean age of 63.4 ± 7.0 years were examined. Twenty-nine subjects had no periodontitis, 11 had a moderate and 4 had a severe form of periodontal disease. High fasting serum glucose (
p
< 0.0001), high BMI scores (
p
= 0.001), low diastolic blood pressure (
p
= 0.030) and high probing depth (
p
= 0.036) were significantly associated with high HbA1c levels.
Conclusions
Within the limitations of this study HbA1c levels are positively associated with high probing pocket depth in patients with non-insulin-dependent diabetes mellitus under physical exercise training. Control and management of active periodontal diseases in non-insulin-dependent patients with diabetes mellitus is reasonable in order to maximize therapeutic outcome of lifestyle interventions.
Journal Article