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Jan Mollenhauer - One of the best experts on this subject based on the ideXlab platform.

  • human DMBT1 derived cell penetrating peptides for intracellular sirna delivery
    Molecular therapy. Nucleic acids, 2017
    Co-Authors: Martina Tuttolomondo, Cinzia Casella, Pernille Lund Hansen, Ester Polo, Luciana M. Herda, Kenneth A. Dawson, Henrik J. Ditzel, Jan Mollenhauer
    Abstract:

    Small interfering RNA (siRNA) is a promising molecule for gene therapy, but its therapeutic administration remains problematic. Among the recently proposed vectors, cell-penetrating peptides show great promise in in vivo trials for siRNA delivery. Human protein DMBT1 (deleted in malignant brain tumor 1) is a pattern recognition molecule that interacts with polyanions and recognizes and aggregates bacteria. Taking advantage of these properties, we investigated whether specific synthetic DMBT1-derived peptides could be used to formulate nanoparticles for siRNA administration. Using an electrophoretic mobility shift assay and UV spectra, we identified two DMBT1 peptides that could encapsulate the siRNA with a self- and co-assembly mechanism. The complexes were stable for at least 2 hr in the presence of either fetal bovine serum (FBS) or RNase A, with peptide-dependent time span protection. ζ-potential, circular dichroism, dynamic light scattering, and transmission electron microscopy revealed negatively charged nanoparticles with an average diameter of 10–800 nm, depending on the reaction conditions, and a spherical or rice-shaped morphology, depending on the peptide and β-helix conformation. We successfully transfected human MCF7 cells with fluorescein isothiocyanate (FITC)-DMBT1-peptide-Cy3-siRNA complexes. Finally, DMBT1 peptides encapsulating an siRNA targeting a fluorescent reporter gene showed efficient gene silencing in MCF7-recombinant cells. These results lay the foundation for a new research line to exploit DMBT1-peptide nanocomplexes for therapeutic siRNA delivery.

  • DMBT1 promotes basal and meconium induced nitric oxide production in human lung epithelial cells in vitro
    Histochemistry and Cell Biology, 2017
    Co-Authors: Hanna Muller, Marcus Renner, Christel Weiss, Ursula Felderhoffmuser, Jan Mollenhauer
    Abstract:

    Meconium aspiration syndrome (MAS) is characterized by surfactant inactivation and inflammation. As lung epithelial cells up-regulate nitric oxide (NO) in response to inflammation, the NO production following meconium exposition was examined in relation to expression of Deleted in Malignant Brain Tumors 1 (DMBT1), a protein with functions in innate immunity and inflammatory regulation. Here, DMBT1 expression was analyzed by immunohistochemistry in postmortem lung sections from patients with MAS. The lung epithelial cell line A549, stably transfected with a DMBT1 (DMBT1+ cells) expression plasmid or with an empty expression plasmid (DMBT1- cells), was exposed to meconium. NO was determined in dependence of aminoguanidine (inducible NO synthase inhibitor), steroids and lipopolysaccharide (LPS). DMBT1 is highly expressed in lungs with MAS. In the absence of meconium, DMBT1+ cells showed a higher NO production than the DMBT1- cells (p = 0.0090). Meconium led in DMBT1- and DMBT1+ cells to elevated NO levels (p < 0.0001), but with a higher NO level in DMBT1+ cells (p < 0.0001). Aminoguanidine, an iNOS inhibitor, reduced the higher NO production in DMBT1+ cells (p = 0.0476), but NO levels remained above NO production from DMBT1- cells (p = 0.0289). Dexamethasone diminished NO production in DMBT1+ cells after meconium exposition (p = 0.0076). Combined addition of LPS and meconium significantly increased NO production in both cell types (p < 0.0001). In comparison to exposure with only meconium, the combined addition of LPS and meconium to the cells increased NO levels in both DMBT1- cells (p = 0.0030) and DMBT1+ cells (p = 0.0028). In conclusion, basal and meconium-induced NO production in lung epithelial cells is positively regulated by DMBT1.

  • Human DMBT1-Derived Cell-Penetrating Peptides for Intracellular siRNA Delivery
    Elsevier, 2017
    Co-Authors: Martina Tuttolomondo, Cinzia Casella, Pernille Lund Hansen, Ester Polo, Luciana M. Herda, Kenneth A. Dawson, Henrik J. Ditzel, Jan Mollenhauer
    Abstract:

    Small interfering RNA (siRNA) is a promising molecule for gene therapy, but its therapeutic administration remains problematic. Among the recently proposed vectors, cell-penetrating peptides show great promise in in vivo trials for siRNA delivery. Human protein DMBT1 (deleted in malignant brain tumor 1) is a pattern recognition molecule that interacts with polyanions and recognizes and aggregates bacteria. Taking advantage of these properties, we investigated whether specific synthetic DMBT1-derived peptides could be used to formulate nanoparticles for siRNA administration. Using an electrophoretic mobility shift assay and UV spectra, we identified two DMBT1 peptides that could encapsulate the siRNA with a self- and co-assembly mechanism. The complexes were stable for at least 2 hr in the presence of either fetal bovine serum (FBS) or RNase A, with peptide-dependent time span protection. ζ-potential, circular dichroism, dynamic light scattering, and transmission electron microscopy revealed negatively charged nanoparticles with an average diameter of 10–800 nm, depending on the reaction conditions, and a spherical or rice-shaped morphology, depending on the peptide and β-helix conformation. We successfully transfected human MCF7 cells with fluorescein isothiocyanate (FITC)-DMBT1-peptide-Cy3-siRNA complexes. Finally, DMBT1 peptides encapsulating an siRNA targeting a fluorescent reporter gene showed efficient gene silencing in MCF7-recombinant cells. These results lay the foundation for a new research line to exploit DMBT1-peptide nanocomplexes for therapeutic siRNA delivery. Keywords: DMBT1, cell-penetrating peptides, cellular uptake, transfection, siRNA delivery, RNAi, silencing, gene knockdown, nanoparticles, nanotherap

  • elevated DMBT1 levels in neonatal gastrointestinal diseases
    Histochemistry and Cell Biology, 2016
    Co-Authors: Jan Mollenhauer, Marcus Renner, Hanna Muller, Burkhard Helmke, Ursula Felderhoffmuser
    Abstract:

    Deleted in malignant brain tumor 1 (DMBT1) is involved in innate immunity and epithelial differentiation. Previous studies in adults indicated a strong intestinal expression of DMBT1 and an important role in inflammatory bowel diseases. Here, we analyzed the DMBT1 expression in the fetal gastrointestinal system depending on gestational age and in patients with necrotizing enterocolitis (NEC), volvulus, intestinal perforation (IP), or herniation, representing typical diseases of preterm and term infants. We used immunohistochemistry and RNA in situ hybridization to detect DMBT1 protein and mRNA in fetal tissues, supplemented by postmortem analysis of DMBT1 expression in died newborns and analysis of surgically removed tissues. DMBT1 expression is detectable in the early developmental stages of the gastrointestinal system. In NEC, volvulus, IP, or herniation, characterized by high systemic inflammatory responses, DMBT1 expression is strongly increased. High DMBT1 expression was also found in the bile ducts of older infants with sepsis or cholestasis. The study shows that DMBT1 expression is observed in the developing gastrointestinal system and up-regulated in infants with NEC, volvulus, IP, and herniation. DMBT1 may play a role in epithelial differentiation and local innate immunity during neonatal inflammatory bowel processes.

  • deleted in malignant brain tumors 1 DMBT1 elicits increased vegf and decreased il 6 production in type ii lung epithelial cells
    BMC Pulmonary Medicine, 2015
    Co-Authors: Jan Mollenhauer, Hanna Muller, Christel Weiss, Christian Nagel, Johannes Poeschl
    Abstract:

    Deleted in malignant brain tumors 1 (DMBT1) is an innate defence protein expressed in the lungs of preterm infants and adults. Recent studies showed that DMBT1 is important in angiogenesis and can bind to different growth factors including VEGF. We aimed at examining relationships between VEGF and IL-6 levels to DMBT1 expression in the lungs of preterm and term infants and in lung epithelial cells in vitro. We examined by ELISA VEGF levels in 120 tracheal aspirates of 57 preterm and term infants and tested for correlation with different perinatal factors as well as with DMBT1 levels. To examine the effect of DMBT1 on VEGF and IL-6 expression we compared type II lung epithelial A549 cells stably transfected with a DMBT1 expression plasmid (DMBT1+ cells) to A549 cells stably transfected with an empty expression plasmid (DMBT1- cells). The concentrations of VEGF and IL-6 were determined via ELISA in the supernatant of the unstimulated cells and after stimulation with LPS, TNFα and Phorbol-12-myristate-13-acetate (PMA). The VEGF levels in the tracheal aspirates of preterm and term infants were significantly correlated with DMBT1 levels (p = 0.0032), the postnatal age (p = 0.0073) and the presence of neonatal infection/sepsis (p = 0.0002). Unstimulated DMBT1+ A549 cells showed significantly higher VEGF expression (p = 0.0017) than DMBT1- cells. Significantly elevated VEGF levels were also confirmed for DMBT1+ cells after stimulation with TNFα (p = 0.0008), LPS (p = 0.0232) and PMA (p = 0.0025). The IL-6 levels were comparable in DMBT1+ versus DMBT1- cells without stimulation (p = 0.6028), but they were significantly reduced in DMBT1+ cells after stimulation with TNFα (p = 0.0003), LPS (p = 0.0088) and PMA (p = 0.0039). The data indicate that DMBT1 promotes VEGF and suppresses IL-6 production in alveolar tissues, which could point to DMBT1 having a possible role in the transition from inflammation to regeneration and being a potentially useful clinical marker.

Annemarie Poustka - One of the best experts on this subject based on the ideXlab platform.

  • The scavenging capacity of DMBT1 is impaired by germline deletions
    Immunogenetics, 2017
    Co-Authors: Floris J Bikker, Caroline End, Stefan Lyer, Marcus Renner, Antoon J M Ligtenberg, Rainer Wittig, Stephanie Blaich, Kamran Nazmi, Arie Nieuw Amerongen, Annemarie Poustka
    Abstract:

    The Scavenger Receptor Cysteine-Rich (SRCR) proteins are an archaic group of proteins characterized by the presence of multiple SRCR domains. They are membrane-bound or secreted proteins, which are generally related to host defense systems in animals. Deleted in Malignant Brain Tumors 1 (DMBT1) is a SRCR protein which is secreted in mucosal fluids and involved in host defense by pathogen binding by its SRCR domains. Genetic polymorphism within DMBT1 leads to DMBT1-alleles giving rise to polypeptides with interindividually different numbers of SRCR domains, ranging from 8 SRCR domains (encoded by 6 kb DMBT1 variant) to 13 SRCR domains (encoded by the 8 kb DMBT1 variant). In the present study, we have investigated whether reduction from 13 to 8 amino-terminal SRCR domains leads to reduction of bacterial binding. The 6 kb variant bound ~20–45% less bacteria compared to the 8 kb variant. These results support the hypothesis that genetic variation in DMBT1 may influence microbial defense.

  • DMBT1 expression distinguishes anorectal from cutaneous melanoma
    Histopathology, 2009
    Co-Authors: Burkhard Helmke, Jan Mollenhauer, Annemarie Poustka, Marcus Renner, Peter Schirmacher, Michael A Kern
    Abstract:

    Aims:  Anorectal melanoma (AM) forms a rare but highly malignant subset of mucosal melanoma with an extremely poor prognosis. Although AMs display histological and immunohistochemical features very similar to cutaneous melanoma (CM), no association exists either with exposure to ultraviolet light or with melanocytic naevi. While AMs are clearly distinguished from CM by displaying few BRAF mutations, they are commonly indistinguishable from CM at the level of gene expression. The aim was to carry out expression analyses of classical immunohistochemical markers and of the protein deleted in malignant brain tumours 1 (DMBT1) in cases of primary anorectal malignant melanoma and CM. Methods and results:  Expression analyses of classical immunohistochemical markers (S100, HMB45, Melan A and MiTF) and of the protein DMBT1 were carried out in 27 cases of primary anorectal malignant melanoma and 26 cases of CM. All AM cases analysed showed expression of at least three of the classical markers for melanoma. However, immunohistochemistry showed 19 out of 27 AM to be positive for DMBT1, which represented a statistically significant difference (P = 0.0009) compared with CM (six out of 26), which more commonly are negative for DMBT1 expression. Conclusion:  These results identify DMBT1 as a molecular feature that may allow distinction between AM and CM and support the notion that AM represents an entity molecularly distinct from CM.

  • respiratory deleted in malignant brain tumours 1 DMBT1 levels increase during lung maturation and infection
    Clinical and Experimental Immunology, 2008
    Co-Authors: Hanna Muller, Caroline End, Marcus Renner, Mathias Hafner, Burkhard Helmke, Christel Weiss, N Gassler, Ashwini Bhandiwad, Annemarie Poustka
    Abstract:

    Summary Deleted in Malignant Brain Tumours 1 (DMBT1) is a secreted scavenger receptor cysteine-rich protein that binds and aggregates various bacteria and virusesinvitro.StudiesinadultshaveshownthatDMBT1isexpressedmainly bymucosalepitheliaandglands,inparticularwithintherespiratorytract,and plays a role in innate immune defence. We hypothesized that respiratory DMBT1 levels may be influenced by various developmental and clinical factors such as maturity, age and bacterial infection. DMBT1 levels were studied in 205 tracheal aspirate samples of 82 ventilated preterm and full- term infants by enzyme-linked immunosorbent assay. Possible effects of various clinical parameters were tested by multiple regression analysis. DMBT1 levels increased significantly with lung maturity (P < 0·0001 for both gestational and postnatal age) and in small-for-gestational-age infants (P = 0·0179). An increase of respiratory DMBT1 levels was detected in neo- natal infections (P < 0·0001). These results were supported by Western blotting. Immunohistochemical analyses of archived newborn lung sections (n = 17) demonstrated high concentrations of DMBT1 in lungs of neonates with bacterial infections. Our data show that preterm infants are able to up-regulate DMBT1 in infection as an unspecific immune reaction.

  • DMBT1 as an archetypal link between infection inflammation and cancer
    Inmunología, 2007
    Co-Authors: Jan Mollenhauer, Caroline End, Marcus Renner, S Lyer, Annemarie Poustka
    Abstract:

    Abstract Epidemiological and molecular studies have pointed to links between infection, inflammation and cancer, which appear to converge at the molecular level in mechanisms associated with innate immunity. Here, the present knowledge about the secreted scavenger receptor cysteine-rich (SRCR) protein Deleted in Malignant Brain Tumors 1 (DMBT1), also known as glycoprotein-340 or salivary agglutinin, is summarized. DMBT1 is differentially expressed in various cancer types with most of these displaying a downregulation. As a lumenally secreted protein, it exerts functions in innate pathogen defense and the regulation of inflammation. By contrast, it may trigger epithelial and stem cell differentiation as an extracellular matrix protein. Its broad responsiveness to pathophysiological stimuli points to a general role in cell and tissue protection, which possibly is best circumscribed by linking pathogen defense and regulation of the inflammatory response to regenerative processes. Compelling similarities to the functions of SRCR proteins in primitive metazoa such as sponges and sea urchins exist, which support that its various functions may rely on an ancient and simple principle, i.e. the differential mediation of adhesion and anti-adhesion. Similar to NF- κB signaling pathways, which are also indirectly regulated by DMBT1, the present state of the art indicates that DMBT1 not only could exert disease-preventing, but probably also disease-promoting functions. Taken together, DMBT1 may represent a paradigm for an archetypal link between infection, inflammation, and cancer. Understanding its complex mode of action promises novel insights into the origin and the molecular basis of major human diseases.

  • DMBT1 is frequently downregulated in well differentiated gastric carcinoma but more frequently upregulated across various gastric cancer types
    International Journal of Oncology, 2007
    Co-Authors: Ana R Conde, Jan Mollenhauer, Annemarie Poustka, Marcus Renner, Ana Paula Martins, Miguel Brito, Armandina Manuel, Sancia Ramos, Joana Maltavacas, Carolino Monteiro
    Abstract:

    Well-differentiated gastric carcinomas are considered to represent a distinct entity emerging via specific molecular changes different from those found in other gastric carcinoma types. The gene deleted in malignant brain tumours 1 (DMBT1) at 10q25.3-q26.1 codes for a protein presumably involved in cell differentiation and protection and has been proposed as a candidate tumour suppressor for brain and epithelial cancer. One study reported a loss of DMBT1 expression in 12.5% (5/40) of gastric cancer samples. Here, we examined in more detail DMBT1 protein and mRNA expression in 78 primary gastric tumour samples and corresponding normal gastric mucosa. DMBT1 was expressed in all non-tumour gastric mucosa tissues. Eleven out of 71 (15%) gastric tumours were negative for the DMBT1 protein in immunohistochemical analyses. Lack of DMBT1 expression was significantly more frequently found in well-differentiated gastric tumours (6/18 well-differentiated tumours vs. 5/53 other subtypes; P=0.025). Quantitative RT-PCR revealed a downregulation of the DMBT1 mRNA for 8/21 (38%) cases, while the remaining 13 cases (62%) displayed a substantial upregulation. Our data suggest that a loss of DMBT1 expression may preferentially take place in well-differentiated gastric carcinoma. However, an upregulation of DMBT1 expression is more frequently found across all gastric cancer types.

Hanna Muller - One of the best experts on this subject based on the ideXlab platform.

  • DMBT1 is upregulated in lung epithelial cells after hypoxia and changes surfactant ultrastructure
    Pediatric Pulmonology, 2020
    Co-Authors: Hanna Muller, Christel Weiss, Andreas Schmiedl, Susan Jung, Marcus Renner
    Abstract:

    Background Hypoxia and asphyxia are known to induce surfactant inactivation in newborns. Deleted in Malignant Brain Tumors 1 (DMBT1) is an innate immunity protein with functions in epithelial differentiation and angiogenesis. It was detected in hyaline membranes of infants with respiratory distress syndrome. Human recombinant DMBT1 is able to increase the surface tension of exogenous surfactant preparations in a dose-dependent manner. Methods Immunohistochemistry was performed on lung sections of infants who died due to pre-, peri- or postnatal hypoxia. The lung epithelial cell line A549 was stably transfected with a DMBT1 (DMBT1+ cells) expression plasmid or with an empty plasmid (DMBT1- cells). The cells were cultured in normoxic or hypoxic conditions, and then DMBT1 as well as HIF-1α RNA expression were analyzed by using real-time-polymerase chain reaction. Human recombinant DMBT1 was added to the modified porcine natural surfactant Curosurf to examine the effect of DMBT1 on surfactant ultrastructure with electron microscopy. Results DMBT1 expression was upregulated in human lung tissue after fetal/peri-/postnatal hypoxia. In addition, in vitro experiments showed increased DMBT1 RNA expression in A549 cells after hypoxia. HIF-1α was upregulated in both DMBT1+ and DMBT1- cells in response to hypoxia. The addition of human recombinant DMBT1 to Curosurf caused an impaired surfactant ultrastructure. Conclusions DMBT1 is upregulated in response to hypoxia and there seems to be a link between hypoxia and surfactant inactivation.

  • DMBT1 promotes basal and meconium induced nitric oxide production in human lung epithelial cells in vitro
    Histochemistry and Cell Biology, 2017
    Co-Authors: Hanna Muller, Marcus Renner, Christel Weiss, Ursula Felderhoffmuser, Jan Mollenhauer
    Abstract:

    Meconium aspiration syndrome (MAS) is characterized by surfactant inactivation and inflammation. As lung epithelial cells up-regulate nitric oxide (NO) in response to inflammation, the NO production following meconium exposition was examined in relation to expression of Deleted in Malignant Brain Tumors 1 (DMBT1), a protein with functions in innate immunity and inflammatory regulation. Here, DMBT1 expression was analyzed by immunohistochemistry in postmortem lung sections from patients with MAS. The lung epithelial cell line A549, stably transfected with a DMBT1 (DMBT1+ cells) expression plasmid or with an empty expression plasmid (DMBT1- cells), was exposed to meconium. NO was determined in dependence of aminoguanidine (inducible NO synthase inhibitor), steroids and lipopolysaccharide (LPS). DMBT1 is highly expressed in lungs with MAS. In the absence of meconium, DMBT1+ cells showed a higher NO production than the DMBT1- cells (p = 0.0090). Meconium led in DMBT1- and DMBT1+ cells to elevated NO levels (p < 0.0001), but with a higher NO level in DMBT1+ cells (p < 0.0001). Aminoguanidine, an iNOS inhibitor, reduced the higher NO production in DMBT1+ cells (p = 0.0476), but NO levels remained above NO production from DMBT1- cells (p = 0.0289). Dexamethasone diminished NO production in DMBT1+ cells after meconium exposition (p = 0.0076). Combined addition of LPS and meconium significantly increased NO production in both cell types (p < 0.0001). In comparison to exposure with only meconium, the combined addition of LPS and meconium to the cells increased NO levels in both DMBT1- cells (p = 0.0030) and DMBT1+ cells (p = 0.0028). In conclusion, basal and meconium-induced NO production in lung epithelial cells is positively regulated by DMBT1.

  • elevated DMBT1 levels in neonatal gastrointestinal diseases
    Histochemistry and Cell Biology, 2016
    Co-Authors: Jan Mollenhauer, Marcus Renner, Hanna Muller, Burkhard Helmke, Ursula Felderhoffmuser
    Abstract:

    Deleted in malignant brain tumor 1 (DMBT1) is involved in innate immunity and epithelial differentiation. Previous studies in adults indicated a strong intestinal expression of DMBT1 and an important role in inflammatory bowel diseases. Here, we analyzed the DMBT1 expression in the fetal gastrointestinal system depending on gestational age and in patients with necrotizing enterocolitis (NEC), volvulus, intestinal perforation (IP), or herniation, representing typical diseases of preterm and term infants. We used immunohistochemistry and RNA in situ hybridization to detect DMBT1 protein and mRNA in fetal tissues, supplemented by postmortem analysis of DMBT1 expression in died newborns and analysis of surgically removed tissues. DMBT1 expression is detectable in the early developmental stages of the gastrointestinal system. In NEC, volvulus, IP, or herniation, characterized by high systemic inflammatory responses, DMBT1 expression is strongly increased. High DMBT1 expression was also found in the bile ducts of older infants with sepsis or cholestasis. The study shows that DMBT1 expression is observed in the developing gastrointestinal system and up-regulated in infants with NEC, volvulus, IP, and herniation. DMBT1 may play a role in epithelial differentiation and local innate immunity during neonatal inflammatory bowel processes.

  • deleted in malignant brain tumors 1 DMBT1 elicits increased vegf and decreased il 6 production in type ii lung epithelial cells
    BMC Pulmonary Medicine, 2015
    Co-Authors: Jan Mollenhauer, Hanna Muller, Christel Weiss, Christian Nagel, Johannes Poeschl
    Abstract:

    Deleted in malignant brain tumors 1 (DMBT1) is an innate defence protein expressed in the lungs of preterm infants and adults. Recent studies showed that DMBT1 is important in angiogenesis and can bind to different growth factors including VEGF. We aimed at examining relationships between VEGF and IL-6 levels to DMBT1 expression in the lungs of preterm and term infants and in lung epithelial cells in vitro. We examined by ELISA VEGF levels in 120 tracheal aspirates of 57 preterm and term infants and tested for correlation with different perinatal factors as well as with DMBT1 levels. To examine the effect of DMBT1 on VEGF and IL-6 expression we compared type II lung epithelial A549 cells stably transfected with a DMBT1 expression plasmid (DMBT1+ cells) to A549 cells stably transfected with an empty expression plasmid (DMBT1- cells). The concentrations of VEGF and IL-6 were determined via ELISA in the supernatant of the unstimulated cells and after stimulation with LPS, TNFα and Phorbol-12-myristate-13-acetate (PMA). The VEGF levels in the tracheal aspirates of preterm and term infants were significantly correlated with DMBT1 levels (p = 0.0032), the postnatal age (p = 0.0073) and the presence of neonatal infection/sepsis (p = 0.0002). Unstimulated DMBT1+ A549 cells showed significantly higher VEGF expression (p = 0.0017) than DMBT1- cells. Significantly elevated VEGF levels were also confirmed for DMBT1+ cells after stimulation with TNFα (p = 0.0008), LPS (p = 0.0232) and PMA (p = 0.0025). The IL-6 levels were comparable in DMBT1+ versus DMBT1- cells without stimulation (p = 0.6028), but they were significantly reduced in DMBT1+ cells after stimulation with TNFα (p = 0.0003), LPS (p = 0.0088) and PMA (p = 0.0039). The data indicate that DMBT1 promotes VEGF and suppresses IL-6 production in alveolar tissues, which could point to DMBT1 having a possible role in the transition from inflammation to regeneration and being a potentially useful clinical marker.

  • cardiac amyloidosis induces up regulation of deleted in malignant brain tumors 1 DMBT1
    Cardiovascular Pathology, 2013
    Co-Authors: Hanna Muller, Marcus Renner, Burkhard Helmke, Christel Weiss, Johannes Poeschl, Frank Bergmann, Gunhild Mechtersheimer, Jan Mollenhauer
    Abstract:

    Abstract Background Amyloidosis is a life-threatening protein misfolding disease and affects cardiac tissue, leading to heart failure, myocardial ischemia and arrhythmia. Amyloid deposits result in oxidative stress, inflammation and apoptosis. The purpose of this study was to examine the role of innate defense components, i.e., Deleted in Malignant Brain Tumors 1 (DMBT1) and the complement system, in different types of cardiac amyloidosis. Methods Expression of DMBT1 and of the complement proteins C1q, C3d and C4d in cardiac specimens of patients with different types of amyloidosis were determined by immunohistochemistry and correlated with amyloid deposits stained by Congo red dye. Results Strong DMBT1 staining adjacent to amyloid deposits was detected in different amyloidosis types, depending on the extent of the deposits. DMBT1 is localized in the endomysium and perimysium, in the endocardium, in the myocytes and in endothelial cells of affected transmural vessels. C1q, C3d and C4d were detected in the amyloid deposits but also in the endomysium and perimysium, in some myocytes, in endothelial cells, in the endocardium, and around the amyloid deposits. Conclusions Up-regulated DMBT1 and complement activation in cardiac amyloidosis may be part of the activated pathways induced by protein aggregation and the consecutive inflammatory reaction.

Marcus Renner - One of the best experts on this subject based on the ideXlab platform.

  • DMBT1 is upregulated in lung epithelial cells after hypoxia and changes surfactant ultrastructure
    Pediatric Pulmonology, 2020
    Co-Authors: Hanna Muller, Christel Weiss, Andreas Schmiedl, Susan Jung, Marcus Renner
    Abstract:

    Background Hypoxia and asphyxia are known to induce surfactant inactivation in newborns. Deleted in Malignant Brain Tumors 1 (DMBT1) is an innate immunity protein with functions in epithelial differentiation and angiogenesis. It was detected in hyaline membranes of infants with respiratory distress syndrome. Human recombinant DMBT1 is able to increase the surface tension of exogenous surfactant preparations in a dose-dependent manner. Methods Immunohistochemistry was performed on lung sections of infants who died due to pre-, peri- or postnatal hypoxia. The lung epithelial cell line A549 was stably transfected with a DMBT1 (DMBT1+ cells) expression plasmid or with an empty plasmid (DMBT1- cells). The cells were cultured in normoxic or hypoxic conditions, and then DMBT1 as well as HIF-1α RNA expression were analyzed by using real-time-polymerase chain reaction. Human recombinant DMBT1 was added to the modified porcine natural surfactant Curosurf to examine the effect of DMBT1 on surfactant ultrastructure with electron microscopy. Results DMBT1 expression was upregulated in human lung tissue after fetal/peri-/postnatal hypoxia. In addition, in vitro experiments showed increased DMBT1 RNA expression in A549 cells after hypoxia. HIF-1α was upregulated in both DMBT1+ and DMBT1- cells in response to hypoxia. The addition of human recombinant DMBT1 to Curosurf caused an impaired surfactant ultrastructure. Conclusions DMBT1 is upregulated in response to hypoxia and there seems to be a link between hypoxia and surfactant inactivation.

  • The scavenging capacity of DMBT1 is impaired by germline deletions
    Immunogenetics, 2017
    Co-Authors: Floris J Bikker, Caroline End, Stefan Lyer, Marcus Renner, Antoon J M Ligtenberg, Rainer Wittig, Stephanie Blaich, Kamran Nazmi, Arie Nieuw Amerongen, Annemarie Poustka
    Abstract:

    The Scavenger Receptor Cysteine-Rich (SRCR) proteins are an archaic group of proteins characterized by the presence of multiple SRCR domains. They are membrane-bound or secreted proteins, which are generally related to host defense systems in animals. Deleted in Malignant Brain Tumors 1 (DMBT1) is a SRCR protein which is secreted in mucosal fluids and involved in host defense by pathogen binding by its SRCR domains. Genetic polymorphism within DMBT1 leads to DMBT1-alleles giving rise to polypeptides with interindividually different numbers of SRCR domains, ranging from 8 SRCR domains (encoded by 6 kb DMBT1 variant) to 13 SRCR domains (encoded by the 8 kb DMBT1 variant). In the present study, we have investigated whether reduction from 13 to 8 amino-terminal SRCR domains leads to reduction of bacterial binding. The 6 kb variant bound ~20–45% less bacteria compared to the 8 kb variant. These results support the hypothesis that genetic variation in DMBT1 may influence microbial defense.

  • DMBT1 promotes basal and meconium induced nitric oxide production in human lung epithelial cells in vitro
    Histochemistry and Cell Biology, 2017
    Co-Authors: Hanna Muller, Marcus Renner, Christel Weiss, Ursula Felderhoffmuser, Jan Mollenhauer
    Abstract:

    Meconium aspiration syndrome (MAS) is characterized by surfactant inactivation and inflammation. As lung epithelial cells up-regulate nitric oxide (NO) in response to inflammation, the NO production following meconium exposition was examined in relation to expression of Deleted in Malignant Brain Tumors 1 (DMBT1), a protein with functions in innate immunity and inflammatory regulation. Here, DMBT1 expression was analyzed by immunohistochemistry in postmortem lung sections from patients with MAS. The lung epithelial cell line A549, stably transfected with a DMBT1 (DMBT1+ cells) expression plasmid or with an empty expression plasmid (DMBT1- cells), was exposed to meconium. NO was determined in dependence of aminoguanidine (inducible NO synthase inhibitor), steroids and lipopolysaccharide (LPS). DMBT1 is highly expressed in lungs with MAS. In the absence of meconium, DMBT1+ cells showed a higher NO production than the DMBT1- cells (p = 0.0090). Meconium led in DMBT1- and DMBT1+ cells to elevated NO levels (p < 0.0001), but with a higher NO level in DMBT1+ cells (p < 0.0001). Aminoguanidine, an iNOS inhibitor, reduced the higher NO production in DMBT1+ cells (p = 0.0476), but NO levels remained above NO production from DMBT1- cells (p = 0.0289). Dexamethasone diminished NO production in DMBT1+ cells after meconium exposition (p = 0.0076). Combined addition of LPS and meconium significantly increased NO production in both cell types (p < 0.0001). In comparison to exposure with only meconium, the combined addition of LPS and meconium to the cells increased NO levels in both DMBT1- cells (p = 0.0030) and DMBT1+ cells (p = 0.0028). In conclusion, basal and meconium-induced NO production in lung epithelial cells is positively regulated by DMBT1.

  • elevated DMBT1 levels in neonatal gastrointestinal diseases
    Histochemistry and Cell Biology, 2016
    Co-Authors: Jan Mollenhauer, Marcus Renner, Hanna Muller, Burkhard Helmke, Ursula Felderhoffmuser
    Abstract:

    Deleted in malignant brain tumor 1 (DMBT1) is involved in innate immunity and epithelial differentiation. Previous studies in adults indicated a strong intestinal expression of DMBT1 and an important role in inflammatory bowel diseases. Here, we analyzed the DMBT1 expression in the fetal gastrointestinal system depending on gestational age and in patients with necrotizing enterocolitis (NEC), volvulus, intestinal perforation (IP), or herniation, representing typical diseases of preterm and term infants. We used immunohistochemistry and RNA in situ hybridization to detect DMBT1 protein and mRNA in fetal tissues, supplemented by postmortem analysis of DMBT1 expression in died newborns and analysis of surgically removed tissues. DMBT1 expression is detectable in the early developmental stages of the gastrointestinal system. In NEC, volvulus, IP, or herniation, characterized by high systemic inflammatory responses, DMBT1 expression is strongly increased. High DMBT1 expression was also found in the bile ducts of older infants with sepsis or cholestasis. The study shows that DMBT1 expression is observed in the developing gastrointestinal system and up-regulated in infants with NEC, volvulus, IP, and herniation. DMBT1 may play a role in epithelial differentiation and local innate immunity during neonatal inflammatory bowel processes.

  • cardiac amyloidosis induces up regulation of deleted in malignant brain tumors 1 DMBT1
    Cardiovascular Pathology, 2013
    Co-Authors: Hanna Muller, Marcus Renner, Burkhard Helmke, Christel Weiss, Johannes Poeschl, Frank Bergmann, Gunhild Mechtersheimer, Jan Mollenhauer
    Abstract:

    Abstract Background Amyloidosis is a life-threatening protein misfolding disease and affects cardiac tissue, leading to heart failure, myocardial ischemia and arrhythmia. Amyloid deposits result in oxidative stress, inflammation and apoptosis. The purpose of this study was to examine the role of innate defense components, i.e., Deleted in Malignant Brain Tumors 1 (DMBT1) and the complement system, in different types of cardiac amyloidosis. Methods Expression of DMBT1 and of the complement proteins C1q, C3d and C4d in cardiac specimens of patients with different types of amyloidosis were determined by immunohistochemistry and correlated with amyloid deposits stained by Congo red dye. Results Strong DMBT1 staining adjacent to amyloid deposits was detected in different amyloidosis types, depending on the extent of the deposits. DMBT1 is localized in the endomysium and perimysium, in the endocardium, in the myocytes and in endothelial cells of affected transmural vessels. C1q, C3d and C4d were detected in the amyloid deposits but also in the endomysium and perimysium, in some myocytes, in endothelial cells, in the endocardium, and around the amyloid deposits. Conclusions Up-regulated DMBT1 and complement activation in cardiac amyloidosis may be part of the activated pathways induced by protein aggregation and the consecutive inflammatory reaction.

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  • elevated DMBT1 levels in neonatal gastrointestinal diseases
    Histochemistry and Cell Biology, 2016
    Co-Authors: Jan Mollenhauer, Marcus Renner, Hanna Muller, Burkhard Helmke, Ursula Felderhoffmuser
    Abstract:

    Deleted in malignant brain tumor 1 (DMBT1) is involved in innate immunity and epithelial differentiation. Previous studies in adults indicated a strong intestinal expression of DMBT1 and an important role in inflammatory bowel diseases. Here, we analyzed the DMBT1 expression in the fetal gastrointestinal system depending on gestational age and in patients with necrotizing enterocolitis (NEC), volvulus, intestinal perforation (IP), or herniation, representing typical diseases of preterm and term infants. We used immunohistochemistry and RNA in situ hybridization to detect DMBT1 protein and mRNA in fetal tissues, supplemented by postmortem analysis of DMBT1 expression in died newborns and analysis of surgically removed tissues. DMBT1 expression is detectable in the early developmental stages of the gastrointestinal system. In NEC, volvulus, IP, or herniation, characterized by high systemic inflammatory responses, DMBT1 expression is strongly increased. High DMBT1 expression was also found in the bile ducts of older infants with sepsis or cholestasis. The study shows that DMBT1 expression is observed in the developing gastrointestinal system and up-regulated in infants with NEC, volvulus, IP, and herniation. DMBT1 may play a role in epithelial differentiation and local innate immunity during neonatal inflammatory bowel processes.

  • cardiac amyloidosis induces up regulation of deleted in malignant brain tumors 1 DMBT1
    Cardiovascular Pathology, 2013
    Co-Authors: Hanna Muller, Marcus Renner, Burkhard Helmke, Christel Weiss, Johannes Poeschl, Frank Bergmann, Gunhild Mechtersheimer, Jan Mollenhauer
    Abstract:

    Abstract Background Amyloidosis is a life-threatening protein misfolding disease and affects cardiac tissue, leading to heart failure, myocardial ischemia and arrhythmia. Amyloid deposits result in oxidative stress, inflammation and apoptosis. The purpose of this study was to examine the role of innate defense components, i.e., Deleted in Malignant Brain Tumors 1 (DMBT1) and the complement system, in different types of cardiac amyloidosis. Methods Expression of DMBT1 and of the complement proteins C1q, C3d and C4d in cardiac specimens of patients with different types of amyloidosis were determined by immunohistochemistry and correlated with amyloid deposits stained by Congo red dye. Results Strong DMBT1 staining adjacent to amyloid deposits was detected in different amyloidosis types, depending on the extent of the deposits. DMBT1 is localized in the endomysium and perimysium, in the endocardium, in the myocytes and in endothelial cells of affected transmural vessels. C1q, C3d and C4d were detected in the amyloid deposits but also in the endomysium and perimysium, in some myocytes, in endothelial cells, in the endocardium, and around the amyloid deposits. Conclusions Up-regulated DMBT1 and complement activation in cardiac amyloidosis may be part of the activated pathways induced by protein aggregation and the consecutive inflammatory reaction.

  • DMBT1 functions as pattern recognition molecule for poly sulfated and poly phosphorylated ligands
    European Journal of Immunology, 2009
    Co-Authors: Caroline End, Stefan Lyer, Marcus Renner, Burkhard Helmke, Gaby Bergmann, Floris J Bikker, Stephanie Blaich, Melanie Hudler, N Gassler
    Abstract:

    Deleted in malignant brain tumors 1 (DMBT1) is a secreted glycoprotein displaying a broad bacterial-binding spectrum. Recent functional and genetic studies linked DMBT1 to the suppression of LPS-induced TLR4-mediated NF-kappaB activation and to the pathogenesis of Crohn's disease. Here, we aimed at unraveling the molecular basis of its function in mucosal protection and of its broad pathogen-binding specificity. We report that DMBT1 directly interacts with dextran sulfate sodium (DSS) and carrageenan, a structurally similar sulfated polysaccharide, which is used as a texturizer and thickener in human dietary products. However, binding of DMBT1 does not reduce the cytotoxic effects of these agents to intestinal epithelial cells in vitro. DSS and carrageenan compete for DMBT1-mediated bacterial aggregation via interaction with its bacterial-recognition motif. Competition and ELISA studies identify poly-sulfated and poly-phosphorylated structures as ligands for this recognition motif, such as heparansulfate, LPS, and lipoteichoic acid. Dose-response studies in DMBT1(-/-) and DMBT1(+/+) mice utilizing the DSS-induced colitis model demonstrate a differential response only to low but not to high DSS doses. We propose that DMBT1 functions as pattern-recognition molecule for poly-sulfated and poly-phosphorylated ligands providing a molecular basis for its broad bacterial-binding specificity and its inhibitory effects on LPS-induced TLR4-mediated NF-kappaB activation. © 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  • DMBT1 expression distinguishes anorectal from cutaneous melanoma
    Histopathology, 2009
    Co-Authors: Burkhard Helmke, Jan Mollenhauer, Annemarie Poustka, Marcus Renner, Peter Schirmacher, Michael A Kern
    Abstract:

    Aims:  Anorectal melanoma (AM) forms a rare but highly malignant subset of mucosal melanoma with an extremely poor prognosis. Although AMs display histological and immunohistochemical features very similar to cutaneous melanoma (CM), no association exists either with exposure to ultraviolet light or with melanocytic naevi. While AMs are clearly distinguished from CM by displaying few BRAF mutations, they are commonly indistinguishable from CM at the level of gene expression. The aim was to carry out expression analyses of classical immunohistochemical markers and of the protein deleted in malignant brain tumours 1 (DMBT1) in cases of primary anorectal malignant melanoma and CM. Methods and results:  Expression analyses of classical immunohistochemical markers (S100, HMB45, Melan A and MiTF) and of the protein DMBT1 were carried out in 27 cases of primary anorectal malignant melanoma and 26 cases of CM. All AM cases analysed showed expression of at least three of the classical markers for melanoma. However, immunohistochemistry showed 19 out of 27 AM to be positive for DMBT1, which represented a statistically significant difference (P = 0.0009) compared with CM (six out of 26), which more commonly are negative for DMBT1 expression. Conclusion:  These results identify DMBT1 as a molecular feature that may allow distinction between AM and CM and support the notion that AM represents an entity molecularly distinct from CM.

  • die rolle von deleted in malignant brain tumors 1 DMBT1 bei der bakteriellen endokarditis und der entstehung von vegetationen
    Zeitschrift Fur Geburtshilfe Und Neonatologie, 2008
    Co-Authors: Hanna Muller, Jan Mollenhauer, Caroline End, Marcus Renner, Burkhard Helmke, C Weis, Johannes Poschl
    Abstract:

    Hintergrund: Die bakterielle Endokarditis (BE) ist eine Infektion der Herzklappen durch Bakterien wie z.B. Staphylokokken, Streptokokken. Gefahrdet sind insbesondere Patienten mit angeborenen und erworbenen Herzfehlern. Wesentlich ist das Auftreten von Vegetationen an den betroffenen Herzklappen. Diese bestehen aus thrombotischem Material, Fibrin, Immunzellen und den infizierenden Bakterien. Das Glykoprotein DMBT1 (Deleted in Malignant Brain Tumors 1) ist ein Mitglied der scavenger receptor cysteine-rich Superfamilie und hat Funktionen bei der epithelialen Differenzierung und der angeborenen Immunabwehr. DMBT1 bindet zahlreiche Bakterien und Viren und interagiert mit verschiedenen Faktoren der unspezifischen Immunabwehr wie z.B. sIgA, SP-D, SP-A. Zusatzlich kann DMBT1 zur Aktivierung von Makrophagen und des Komplementsystems fuhren. Fragestellung: Ziel war zu eruieren, ob DMBT1 bei der BE exprimiert wird und ob es einen Einfluss auf die Absiedelung von Bakterien und die Entstehung von Vegetationen ausubt. Material und Methoden: Mittels Immunhistochemie wurde die DMBT1-Expression im kardialen Gewebe von Patienten mit BE untersucht. Den Einfluss von rekombinantem DMBT1 (rDMBT1) auf die Erythrozytenaggregation (EA) wurde mithilfe eines Erythrozyten-Aggregometers (Myrenne, Roetgen) getestet. Bei der statistischen Analyse wurden Varianzanalysen (ANOVA) und t-Tests angewandt. Ergebnisse und Diskussion: Die Patienten mit BE zeigten eine massive DMBT1-Expression im Bereich der betroffenen Herzklappen, wobei DMBT1 insbesondere beim Fibrin der Vegetationen und bei den auf den Klappen und in den Vegetationen nachweisbaren Bakterien lokalisiert war. In vitro zeigte sich eine konzentrationsabhangige Steigerung der EA durch rDMBT1 (p<0,0001), die aber auch durch die Antikoagulation des Blutes beeinflusst wurde (p<0,0001). Die groste Steigerung der EA (im Mittel +32%) wurde bei Heparin-Blut mit einer rDMBT1-Konzentration von 12µg/ml beobachtet. Die Strukturveranderung von rDMBT1 durch Erhitzen fuhrte beim Heparin-Blut zu einer signifikant geringeren Beeinflussung der EA (+32% vs. +18%; p=0,016). Schlussfolgerung: DMBT1 konnte pathophysiologisch bei der BE von Bedeutung sein, indem es an Bakterien und/oder Fibrin bindet, die EA induziert und die Entstehung von konsekutiven Vegetationen unterstutzt.