M Meilinger

Publications (9)16.66 Total impact

• Article: Attraktive Lehre und Ausbildung – gesicherte Zukunft der Urologie

  M. Meilinger, L. Durner, N. von Ostau
  Der Urologe 05/2012; 50(5):605-606. · 0.50 Impact Factor
• Article: [Additional classification "medicinal tumor therapy": statement by the German Society of Residents in Urology (GeSRU)].

  M Neuhäuser, S Schöne, M Meilinger, C Ruf, A Martinschek
  Der Urologe 04/2012; 51(5):721-3. · 0.50 Impact Factor
• Article: [10 years of GeSRU (German Society of Residents in Urology) assistant workshops in Garmisch-Partenkirchen].

  M Meilinger, N von Ostau, S Schöne
  Der Urologe 08/2011; 50(9):1168. · 0.50 Impact Factor
• Article: [Attractive teaching and training - secure future for urology: the program of the German Society of Residents in Urology (GeSRU)].

  M Meilinger, L Durner, N von Ostau
  Der Urologe 05/2011; 50(5):605-6. · 0.50 Impact Factor
• Article: [Optimization of specialized medical training--2008 activities of the German Society of Residents in Urology. Annual schedule with a wide choice of innovative continuing education courses].

  N von Ostau, M Meilinger
  Der Urologe 03/2008; 47(2):212-4. · 0.50 Impact Factor
• Article: Metabolism of activated complement component C3 is mediated by the low density lipoprotein receptor-related protein/alpha(2)-macroglobulin receptor.

  M Meilinger, C Gschwentner, I Burger, M Haumer, M Wahrmann, L Szollar, J Nimpf, M Huettinger
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  ABSTRACT: Complement component 3 (C3) and alpha(2)-macroglobulin evolved from a common, evolutionarily old, ancestor gene. Low density lipoprotein-receptor-related protein/alpha(2)-macroglobulin receptor (LRP/alpha(2)MR), a member of the low density lipoprotein receptor family, is responsible for the clearance of alpha(2)-macroglobulin-protease complexes. In this study, we examined whether C3 has conserved affinity for LRP/alpha(2)MR. Ligand blot experiments with human (125)I-C3 on endosomal proteins show binding to a 600-kDa protein, indistinguishable from LRP/alpha(2)MR by the following criteria: it is competed by receptor-associated protein (the 39-kDa receptor-associated protein that impairs binding of all ligands to LRP/alpha(2)MR) and by lactoferrin and Pseudomonas exotoxin, other well known ligands of the multifunctional receptor. Binding of C3 is sensitive to reduction of the receptor and is Ca(2+)-dependent. All these features are typical for cysteine-rich binding repeats of the low density lipoprotein receptor family. In LRP/alpha(2)MR, they are found in four cassettes (2, 8, 10, and 11 repeats). Ligand blotting to chicken LR8 demonstrates that a single 8-fold repeat is sufficient for binding. Confocal microscopy visualizes initial surface labeling of human fibroblasts incubated with fluorescent labeled C3, which changes after 5 min to an intracellular vesicular staining pattern that is abolished in the presence of receptor-associated protein. Cell uptake is abolished in mouse fibroblasts deficient in LRP/alpha(2)MR. Native plasma C3 is not internalized. We demonstrate that the capacity to internalize C3 is saturable and exhibits a K(D) value of 17 nM. After intravenous injection, rat hepatocytes accumulate C3 in sedimentable vesicles with a density typical for endosomes. In conclusion, our ligand blot and uptake studies demonstrate the competence of the LRP/alpha(2)MR to bind and endocytose C3 and provide evidence for an LRP/alpha(2)MR-mediated system participating in C3 metabolism.
  Journal of Biological Chemistry 12/1999; 274(53):38091-6. · 4.77 Impact Factor
• Article: The LDL-receptor family. Lactoferrin and lipid metabolism.

  M Huettinger, M Meilinger, C Gschwentner, H Lassmann
  Advances in experimental medicine and biology 02/1998; 443:107-11. · 1.09 Impact Factor
• Article: The chicken oocyte receptor for yolk precursors as a model for studying the action of receptor-associated protein and lactoferrin.

  T Hiesberger, M Hermann, L Jacobsen, S Novak, R A Hodits, H Bujo, M Meilinger, M Hüttinger, W J Schneider, J Nimpf
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  ABSTRACT: Receptor-associated protein (RAP) was originally described as a 39-kDa intracellular protein copurifying with mammalian low density lipoprotein (LDL) receptor-related protein/alpha 2-macroglobulin receptor (LRP/alpha 2MR). RAP has a high affinity for LRP/alpha 2MR and interferes with the receptor's ability to bind a variety of ligands. The laying hen expresses, in a tissue-specific manner, at least four different proteins which belong to the same family of receptors as LRP/alpha 2MR. Here we show that the chicken also produces RAP, so far thought to be expressed only in mammals. Studies on the interaction of recombinant human RAP with the LDL receptor family in the chicken revealed that RAP binds with high affinity to the abundant oocyte receptor for yolk precursors (OVR) as well as to the somatic cell-specific LRP/alpha 2MR. Significantly, RAP interacts with a lower affinity with the LDL receptor, but does not bind to the oocyte-specific form of LRP. Binding of RAP to OVR inhibits the interaction of the receptor with all known physiological ligands, i.e. the yolk precursors very low density lipoprotein, vitellogenin, and alpha 2-macroglobulin. In COS cells transfected with OVR, RAP is internalized and degraded in a concentration-dependent and saturable manner. Lactoferrin, another protein with a high affinity for mammalian LRP/alpha 2MR, also binds to OVR and abolishes its interaction with yolk precursors. Cross-competition experiments show that RAP and lactoferrin recognize sites different from those involved in yolk precursor binding. The availability of pure OVR and LDLR enable us to determine kinetic parameters for the binding of RAP and lactoferrin to these receptors by surface plasmon resonance. Taken together, our results strongly suggest that chicken OVR, which is easily accessible and highly abundant in growing oocytes, represents a superior system for studying mechanistic and structural aspects of the interaction of ligands and modulating proteins with members of the LDL receptor gene family.
  Journal of Biological Chemistry 09/1995; 270(31):18219-26. · 4.77 Impact Factor
• Source

  Available from: Ferdinand Steinboeck

  Article: Removal of lactoferrin from plasma is mediated by binding to low density lipoprotein receptor-related protein/alpha 2-macroglobulin receptor and transport to endosomes

  M. Meilinger, M. Haumer, K. A. Szakmary, F. Steinbock, B. Scheiber, H. Goldenberg, M. Huettinger
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  ABSTRACT: LDL receptor related protein (LRP) is a ubiquitously expressed cell surface receptor that binds, at least in vitro, a plethora of ligands among them alpha 2-macroglobulin and lactoferrin (Lf). The function of LRP in internalisation and distribution of ligands within cellular metabolism is still unclear. We here investigated by combined ligand- and immunoblotting the participation of LRP/alpha 2MR and its associated protein (RAP) in receptor mediated endocytosis of Lf into rat liver. We found LRP highly enriched in sucrose density gradient fractions around density 1.10 g/ml, previously characterised as endosomal fractions. RAP was concentrated in distinct fractions around density 1.14 g/ml. This separation of RAP from LRP/alpha 2MR is physiologically meaningful as RAP avidly binds to LRP/alpha 2MR and by that shuts off all ligand binding function. In endosomal fractions we found one single binding protein for 125I-labelled Lf. With a specific anti LRP/alpha 2MR antibody and ligand blotting with 125I-labelled RAP this endosomal Lf binding site was verified to be LRP/alpha 2MR. Endosomes did not bind labelled Lf when prepared from rats that received an intravenous injection of Lf (20 mg per animal) 20 min prior to preparation. Surprisingly we immunodetected Lf in these endosomes at a position around 600 kDa, comigrating with LRP/alpha 2MR. We determined Lf binding to be optimal at pH 5.8, what led us to suggest the existence of a very stable LF-LRP/alpha 2MR complex in endosomes. These data support the idea of effective binding of Lf at pH as found in inflamed tissue environment where Lf is reported to be involved in leukocyte mediated inflammation regulation.
  FEBS Letters 01/1995; 360(1):70-4. · 3.54 Impact Factor