| 1. |
- Franco, Claudio Areias, et al.
(författare)
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Serum response factor is required for sprouting angiogenesis and vascular integrity
- 2008
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Ingår i: Developmental Cell. - : Elsevier BV. - 1534-5807. ; 15:3, s. 448-461
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Tidskriftsartikel (refereegranskat)abstract
- Serum response factor (SRF) is a transcription factor that controls the expression of cytoskeletal proteins and immediate early genes in different cell types. Here, we found that SRF expression is restricted to endothelial cells (ECs) of small vessels such as capillaries in the mouse embryo. EC-specific Srf deletion led to aneurysms and hemorrhages from 11.5 days of mouse development (E11.5) and lethality at E14.5. Mutant embryos presented a reduced capillary density and defects in EC migration, with fewer numbers of filopodia in tip cells and ECs showing defects in actin polymerization and intercellular junctions. We show that SRF is essential for the expression of VE-cadherin and beta-actin in ECs both in vivo and in vitro. Moreover, knockdown of SRF in ECs impaired VEGF- and FGF-induced in vitro angiogenesis. Taken together, our results demonstrate that SRF plays an important role in sprouting angiogenesis and small vessel integrity in the mouse embryo.
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| 2. |
- Gustafsson, Erika, et al.
(författare)
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Identification of conformational epitopes for human IgG on chemotaxis inhibitory protein of Staphylococcus aureus
- 2009
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Ingår i: BMC Immunology. - : Springer Science and Business Media LLC. - 1471-2172. ; 10:13
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Tidskriftsartikel (refereegranskat)abstract
- Background The Chemotaxis inhibitory protein of Staphylococcus aureus (CHIPS) blocks the Complement fragment C5a receptor (C5aR) and formylated peptide receptor (FPR) and is thereby a potent inhibitor of neutrophil chemotaxis and activation of inflammatory responses. The majority of the healthy human population has antibodies against CHIPS that have been shown to interfere with its function in vitro. The aim of this study was to define potential epitopes for human antibodies on the CHIPS surface. We also initiate the process to identify a mutated CHIPS molecule that is not efficiently recognized by preformed anti-CHIPS antibodies and retains anti-inflammatory activity. Results In this paper, we panned peptide displaying phage libraries against a pool of CHIPS specific affinity-purified polyclonal human IgG. The selected peptides could be divided into two groups of sequences. The first group was the most dominant with 36 of the 48 sequenced clones represented. Binding to human affinity-purified IgG was verified by ELISA for a selection of peptide sequences in phage format. For further analysis, one peptide was chemically synthesized and antibodies affinity-purified on this peptide were found to bind the CHIPS molecule as studied by ELISA and Surface Plasmon Resonance. Furthermore, seven potential conformational epitopes responsible for antibody recognition were identified by mapping phage selected peptide sequences on the CHIPS surface as defined in the NMR structure of the recombinant CHIPS31-121 protein. Mapped epitopes were verified by in vitro mutational analysis of the CHIPS molecule. Single mutations introduced in the proposed antibody epitopes were shown to decrease antibody binding to CHIPS. The biological function in terms of C5aR signaling was studied by flow cytometry. A few mutations were shown to affect this biological function as well as the antibody binding. Conclusions Conformational epitopes recognized by human antibodies have been mapped on the CHIPS surface and amino acid residues involved in both antibody and C5aR interaction could be defined. This information has implications for the development of an effective anti-inflammatory agent based on a functional CHIPS molecule with low interaction with human IgG.
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| 3. |
- Gustafsson, Erika
(författare)
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Molecular evolution of a C5aR antagonist against inflammatory disease
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- New anti-inflammatory drugs with fewer adverse effects than existing drugs may prove to be useful in the treatment of several inflammatory disorders. A critical step in acute inflammation is the infiltration of neutrophils into tissues. Therefore, molecules that target and inhibit this early inflammatory event are attractive to engineer to suit medical needs. The Chemotaxis Inhibitory Protein of Staphylococcus aureus (CHIPS) binds and blocks the C5a receptor (C5aR) and formylated peptide receptor (FPR) and is therefore a potent inhibitor of activation and migration of neutrophils. However, as the majority of the human population has been exposed to S. aureus, pre-existing antibodies against CHIPS will be present in human sera. This thesis is based on four original papers, with the overall aim to decrease the interaction of CHIPS with pre-existing human IgG in order to tailor it for pharmaceutical purposes. Specific IgG epitopes on the CHIPS surface were mapped by the use of phage displayed random peptide libraries. This study showed that polyclonal CHIPS specific IgGs mainly recognize conformational epitopes exposed on the surface. In addition, amino acid residues in CHIPS that are involved in this interaction, as well as in C5aR inhibition were identified. Directed evolution is a process commonly used to improve certain protein properties without the need for detailed prior knowledge of the protein structure. This can be performed by the use of in vitro DNA recombination, a procedure by which beneficial mutations from a randomly mutated library can be recombined to generate new protein variants. In this thesis, the DNA recombination technology Fragment INduced Diversity (FIND), was applied in combination with molecular modeling and site-directed mutagenesis to generate CHIPS variants with low interaction with human IgG and retained ability to inhibit the C5aR. One CHIPS variant, designated ADC-1004, was selected for further studies. This new CHIPS variant, has high affinity for the C5aR and inhibits it efficiently, despite the truncation and seven mutations that mediate low interaction with pre-existing human IgG.
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| 4. |
- Gustafsson, Erika, et al.
(författare)
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Purification of truncated and mutated chemotaxis inhibitory protein of Staphylococcus aureus—an anti-inflammatory protein
- 2009
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Ingår i: Protein Expression and Purification. - : Elsevier BV. - 1046-5928. ; 63:2, s. 95-101
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Tidskriftsartikel (refereegranskat)abstract
- The Chemotaxis Inhibitory Protein of Staphylococcus aureus (CHIPS) binds and blocks the C5a receptor (C5aR) and formyl-peptide receptor (FPR). This way, CHIPS is a potent inhibitor of the immune cell recruitment associated with inflammation. Truncation of the protein and the introduction of mutations, shifts the expression towards the insoluble fraction of Escherichia coli, whereas the wild-type protein can be solubly expressed. A protocol for expression and tag independent purification of biologically active CHIPS variants has been established to enable further characterization of an improved CHIPS variant, called ADC-1004. The CHIPS variants were purified by washing of E. coli inclusion bodies followed by refolding and gel filtration. New techniques were utilized to optimize the purification process. Expression in inclusion bodies was increased by the use of Ultra Yield™ flasks and optimal refolding conditions were determined by the use of the iFOLD Refolding System 2™. The folding and biological activity of the purified proteins were analyzed by circular dichroism (CD) spectroscopy and flow cytometry, respectively, and compared to solubly produced CHIPS31–113 and wild-type CHIPS1–121. We show that the CHIPS variants produced in inclusion bodies can be refolded and purified to achieve equal biological activity as solubly produced CHIPS31–113 and wild-type CHIPS1–121. The truncation causes minor structural changes while purification from inclusion bodies or the soluble fraction does not further affect the structure.
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| 5. |
- Gustafsson, Lisa, 1975-
(författare)
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Endogenous Opioids and Voluntary Ethanol Drinking : Consequences of Postnatal Environmental Influences in Rats
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Genetic and environmental factors interact to determine the individual vulnerability to develop ethanol dependence. The neurobiological mechanisms underlying these processes are not fully understood. Endogenous opioid peptides have been suggested to contribute. Brain opioids mediate ethanol reward and reinforcement via actions on the mesocorticolimbic dopamine system. This thesis focuses on environmental factors and investigates the impact of the early-life environment on adult voluntary ethanol consumption. The possible involvement of opioid peptides in environmental influences on adult ethanol consumption was examined using an experimental animal model. Maternal separation with short 15 min separations (MS15) was used to simulate a safe environment whereas prolonged 360 min separations (MS360) simulated an unsafe environment. Control rats were subjected to normal animal facility rearing (AFR). The separations were performed daily from postnatal day 1 to 21. Long-term ethanol consumption was registered using a two-bottle or a four-bottle free-choice paradigm in adult male and female ethanol-preferring AA (Alko, Alcohol), ethanol-avoiding ANA (Alko, Non-Alcohol) and non-preferring Wistar rats. In addition, analyses of immunoreactive Met-enkephalin-Arg6Phe7 (MEAP), dynorphin B (DYNB) and nociceptin/orphanin FQ (N/OFQ) peptide levels were performed after maternal separation as well as after voluntary ethanol drinking. In male rats, MS15 was related to lower ethanol consumption and these rats preferred lower concentrations, whereas MS360 was associated with an increased risk for higher consumption and/or preference for higher ethanol concentrations. Differences in basal opioid levels were observed in MS15 and MS360 rats. Furthermore, the ethanol-induced effects on opioid peptides in adults were dependent on the early environment. Female rats, on the other hand, were less affected or unaffected by maternal separation both in terms of ethanol consumption and neurobiological effects. Taken together, voluntary ethanol drinking, preference for low or high ethanol concentrations and opioid peptides in brain areas related to reward and reinforcement, motivation and stress were influenced by postnatal maternal separation in a sex dependent manner. The early environment thus had profound impact on the adult brain and the individual propensity for high ethanol drinking. A deranged endogenous opioid system contributed to these effects and may act as a mediator for long-term environmental influence on voluntary ethanol consumption.
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| 6. |
- Kvist, Alexander, et al.
(författare)
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Chondroitin sulfate perlecan enhances collagen fibril formation - Implications for perlecan chondrodysplasias
- 2006
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Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 281:44, s. 33127-33139
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Tidskriftsartikel (refereegranskat)abstract
- Inactivation of the perlecan gene leads to perinatal lethal chondrodysplasia. The similarity to the phenotypes of the Col2A1 knock-out and the disproportionate micromelia mutation suggests perlecan involvement in cartilage collagen matrix assembly. We now present a mechanism for the defect in collagen type II fibril assembly by perlecan-null chondrocytes. Cartilage perlecan is a heparin sulfate or a mixed heparan sulfate/ chondroitin sulfate proteoglycan. The latter form binds collagen and accelerates fibril formation in vitro, with more defined fibril morphology and increased fibril diameters produced in the presence of perlecan. Interestingly, the enhancement of collagen fibril formation is independent on the core protein and is mimicked by chondroitin sulfate E but neither by chondroitin sulfate D nor dextran sulfate. Furthermore, perlecan chondroitin sulfate contains the 4,6-disulfated disaccharides typical for chondroitin sulfate E. Indeed, purified glycosaminoglycans from perlecan-enriched fractions of cartilage extracts contain elevated levels of 4,6-disulfated chondroitin sulfate disaccharides and enhance collagen fibril formation. The effect on collagen assembly is proportional to the content of the 4,6- disulfated disaccharide in the different cartilage extracts, with growth plate cartilage glycosaminoglycan being the most efficient enhancer. These findings demonstrate a role for perlecan chondroitin sulfate side chains in cartilage extracellular matrix assembly and provide an explanation for the perlecan-null chondrodysplasia.
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| 7. |
- Rapp [Nordin], Erika, et al.
(författare)
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Preference for full-fat over low-fat foods among individuals suffering from coronary heart disease and healthy controls
- 2009
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Ingår i: Physiology and Behavior. - : Elsevier. - 0031-9384 .- 1873-507X. ; 98:4, s. 489-497
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Tidskriftsartikel (refereegranskat)abstract
- Dietary behaviour can modify the risks for coronary heart disease (CHD). Dietary fat contributes to the sensory characteristics of many foods, but there are individual differences in liking for regular and reduced fat products. Preference for dietary fat might differ between healthy individuals and those of diagnosed CHD status. Preference for full-fat versus low-fat foods was assessed in a group suffering from CHD (N = 24) and a healthy control group (N = 41). Preferences were evaluated using a series of paired preference tests including 34 food pairs. Further, patterns across fat preference and a range of known risk factors for CHD were examined. The study was conducted in Sweden; March 2004 until May 2006. Overall the full-fat food items were preferred to the low-fat alternatives by both patients and control participants. The pattern of preference responses diverged significantly between patients and controls on only four of the 34 food items, in both directions, why preference related to total fat content per se is not confirmed as differentiating significantly between a group diagnosed with CHD compared to a healthy control group.
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| 8. |
- Rapp [Nordin], Erika, 1970-
(författare)
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Sensory, attitudinal, and contextual aspects of the meal : health implications and connections with risk factors for coronary heart disease and obesity
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Det övergripande syftet var att undersöka mat- och måltidsrelaterade faktorer som bidragande orsak till övervikt och hjärt-kärlsjukdom.I en sensorisk studie jämfördes individer som insjuknat i hjärtinfarkt med en frisk kontroll-grupp med avseende på preferens för mat med hög respektive låg fetthalt, smakkänslighet för grundsmakerna (surt, beskt, salt, sött, umami och metalliskt) samt det beska ämnet 6-n-propylthiouracil (PROP). Undersökningsgruppen hade mer ogynnsam metabolisk profil, vilket kan indikera högre intag av fet, energirik mat och mindre intag av frukt och grönsaker, jämfört med kontrollgruppen. Det påvisades emellertid ingen signifikant skillnad i smakkänslighet mel-lan grupperna. När grupperna slogs samman konstaterades däremot att känslighet för surt var relaterat till lågt body mass index (BMI), och känslighet för beska var relaterat till lågt HDL-kolesterol samt högt BMI och bukfetma. Det indikerar ett samband mellan riskprofil, smak-känslighet och matvanor. Upplevd beska kan vara en bidragande orsak till låg konsumtion av frukt och grönsaker. Båda grupperna föredrog generellt mat med hög fetthalt, varför preferens för hög fetthalt i sig inte kan anses vara en bidragande riskfaktor för insjuknande i hjärtinfarkt. För hälften av rätterna påvisades emellertid ingen signifikant skillnad i preferens för hög- respek-tive låg fetthalt. För att undersöka hur sensoriska egenskaper förändras vid olika fetthalter stu-derades två såser med varierande smörmängd. Totalt sett minskade smakegenskaperna (tomat, vitlök, timjan, kyckling, syrlighet) när mer smör tillsattes, medan smörsmaken och såsernas vis-kositet ökade. Stor skillnad i smörmängd (energiinnehåll) frambringar däremot endast små smakförändringar.I en enkätstudie påvisades att matvanor och inställning till mat och hälsa skilde sig mellan män och kvinnor samt beroende av BMI. En klusteranalys resulterade i tre grupper, varav en grupp med jämn könsfördelning som i genomsnitt hade högre BMI och sämre matvanor. I den gruppen ingick kvinnor som är mindre intresserade av sin hälsa och män som är mer fokuserade på mat som njutning, vilket indikerar att orsakerna till ohälsosamma matvanor skiljer sig mellan kvinnor och män. I en öppen fråga beskrevs essensen i en god måltid innefatta både krav på maten (råvaror, maträtter, menyer, sensoriska egenskaper samt näring och mättnad) och krav på sammanhanget (estetik, gemenskap, lugn och ro, och sinnesstämning). Att identifiera indivi-ders olika anspråk på en god måltid kan vara komplementära kunskaper till hjälp vid föränd-ring av mat- och måltidsvanor. Slutligen bidrog en litteraturfördjupning till kunskaper om mat- måltidsupplevelser med fokus på uppskattning och tillfredsställelse i relation till hälsotillstånd.Resultaten indikerar att det är av betydelse att identifiera enskilda individers förutsättningar och preferenser för mat och måltider vad gäller smak, matvanor och kontext i vardagen för att underlätta intervention och hälsofrämjande arbete.
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| 9. |
- Rapp [Nordin], Erika, et al.
(författare)
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The sensory effect of butter in culinary sacues
- 2007
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Ingår i: Journal of Foodservice. - : Blackwell Publishing. - 1748-0159 .- 1748-0140. ; 18:1, s. 31-42
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Tidskriftsartikel (refereegranskat)abstract
- A common belief is that when butter is added to food, a more desired flavour develops and that other flavours are enhanced. The aim of this study was to investigate how different amounts of added butter affected the perceived sensory characteristics of tomato sauce and chicken velouté using sensory analysis. In addition, a preference test was performed for tomato sauce. As more butter was added, the intensity of butter flavour and the viscosity increased, and the other flavour, aroma and taste attributes tested were perceived as being less intense in varying magnitudes. No significant difference was obtained in the preference study, except liking of the appearance among the men who preferred the sauce containing less butter. The results show that a large amount of butter is not always essential, unless it is the flavour and aroma of butter itself that is sought, or if it is necessary to balance the flavour, taste and texture attributes. These results could have a positive health effect for consumers if the use of fat in restaurant kitchens is reduced.
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| 10. |
- Roman, Erika, et al.
(författare)
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Behavioral profiles and stress-induced corticosteroid secretion in male Wistar rats subjected to short and prolonged periods of maternal separation
- 2006
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Ingår i: Hormones and Behavior. - : Elsevier BV. - 0018-506X .- 1095-6867. ; 50:5, s. 736-747
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Tidskriftsartikel (refereegranskat)abstract
- Early life experiences are important for the development of neurobiobehavioral mechanisms and subsequent establishment of mental functions. In experimental animals, early life experiences can be studied using the maternal separation model. Maternal separation has been described to induce neurobiological changes and thus affect brain function, mental state and behavior. We have established a protocol in order to study the effects of repeated short and prolonged periods of maternal separation during the postnatal period on adult neurochemistry, voluntary ethanol intake and behavior. In the present experiment, we focus on the long-term effects of maternal separation on exploration and risk assessment behavior as well corticosteroid secretion. Rat pups were assigned to 15 min (MS15) or 360 min (MS360) of daily maternal separation and normal animal facility rearing (AFR) during postnatal days 1-21. To establish the adult behavioral profile in male rats, three tests were used: the Concentric Square Field (CSF), the Open Field (OF) and the Elevated Plus-maze (EPM). No differences between the three experimental groups were found in the traditional OF and EPM tests. The CSF test indicated that the MS360 rats were more explorative and expressed an altered risk assessment and risk-taking profile. In response to a restraint stress, MS360 rats had a blunted corticosterone release in contrast to MS15 and AFR rats. In contrast to previous results, the outcome of the present investigation does not support the notion that a prolonged period of maternal separation results in an adult phenotype characterized by an increased emotional reactivity.
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| 11. |
- Roman, Erika, et al.
(författare)
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Short and prolonged periods of maternal separation and voluntary ethanol intake in male and female ethanol-preferring AA and ethanol-avoiding ANA rats
- 2005
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Ingår i: Alcoholism. - 0145-6008 .- 1530-0277. ; 29:4, s. 591-601
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Genetic as well as environmental factors can affect the propensity for psychopathology and/or drug dependence. Maternal separation represents an animal experimental model that is useful in studies of effects of early life experiences. The authors have established a protocol for short and prolonged periods of maternal separation to study adult neurochemistry, behavior, and ethanol intake and have previously reported alterations in ethanol intake in Wistar rats and ethanol-preferring rats. The aim of the current study was to more thoroughly study how early life experiences affect an inherited propensity for high and low ethanol intake, respectively, in male and female ethanol-preferring AA (Alko alcohol) and ethanol-avoiding ANA (Alko, Non-Alcohol) rats. METHODS: AA and ANA pups were assigned to one of three different rearing conditions: 15 min (MS15) or 360 min (MS360) of daily maternal separation in litters or normal animal facility rearing (AFR) during postnatal days 1 to 21. In adulthood, voluntary ethanol intake was investigated using the two-bottle free choice paradigm. RESULTS: In male ethanol-preferring AA rats, MS15 resulted in a lower intake and fewer high-preferring animals at 8% and 10% ethanol compared with MS360 rats. The male MS360 rats had a higher ethanol intake at 8% and 10% ethanol in comparison with AFR rats. In contrast, the female AA MS15 and MS360 rats had a lower ethanol intake and a lower preference for the 10% ethanol solution compared with the female AA AFR rats. In male and female ANA rats, no major separation-induced effects were found. CONCLUSIONS: The current results show that genetic inheritance can be affected by environmental manipulations in AA rats with an inherent high ethanol intake. The findings in female ethanol-preferring AA rats give further evidence of a differential outcome of maternal separation in male and female rats, as previously shown.
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| 12. |
- Roman, Erika, et al.
(författare)
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Variations in opioid peptide levels during the estrous cycle in Sprague-Dawley rats
- 2006
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Ingår i: Neuropeptides. - : Elsevier BV. - 0143-4179 .- 1532-2785. ; 40:3, s. 195-206
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Tidskriftsartikel (refereegranskat)abstract
- The estrous cycle, with its various hormonal conditions, may provide us with the means of understanding how endocrine states relate to opioid mechanisms. There has been increasing experimental support for interaction between sex steroids and opioid peptides in the central nervous system. Here, we describe fluctuations in endogenous brain immunoreactive (ir) peptide levels during various phases of the estrous cycle in the female Sprague-Dawley rat. Ir levels of dynorphin A, dynorphin B, Leu-enkephalin-Arg(6), Met-enkephalin-Arg(6)Phe(7) and nociceptin/orphanin FQ were measured in the pituitary gland and in 10 areas of the brain during the diestrus, proestrus and estrus phase. In several areas of the brain, basal levels of endogenous opioid peptides showed variation during the course of the estrous cycle. Significant differences were found between the diestrus state and the proestrus and/or estrus conditions, particularly in the nucleus accumbens, caudate putamen and the substantia nigra. The ir levels of the endogenous peptide nociceptin/orphanin FQ became altered in only one of the areas measured, indicating less variance during the estrous cycle. Correlation analyses revealed that significant associations between dynorphin A or dynorphin B and Leu-enkephalin-Arg(6) were found more often during estrus than during the diestrus and proestrus conditions. The ratio between the ir levels of Leu-enkephalin-Arg(6), a cleavage product of the enzymatic conversion of dynorphin peptides into shorter peptides in vivo, and dynorphin peptides was calculated. The significantly lower ratio between Leu-enkephalin-Arg(6) and dynorphin B in diestrus than in proestrus and estrus also indicates cyclic fluctuations in the enzymatic cleavage of dynorphin. These findings are discussed in relation to the possible role of interactions between sex steroids and opioid peptide mechanisms during the normal estrous cycle.
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| 13. |
- Sasse, Philipp, et al.
(författare)
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Perlecan is critical for heart stability
- 2008
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Ingår i: Cardiovascular Research. - : Oxford University Press (OUP). - 1755-3245 .- 0008-6363. ; 80:3, s. 435-444
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Tidskriftsartikel (refereegranskat)abstract
- Perlecan is a heparansulfate proteoglycan found in basement membranes, cartilage, and several mesenchymal tissues that form during development, tumour growth, and tissue repair. Loss-of-function mutations in the perlecan gene in mice are associated with embryonic lethality caused primarily by cardiac abnormalities probably due to hemopericards. The aim of the present study was to investigate the mechanism underlying the early embryonic lethality and the pathophysiological relevance of perlecan for heart function. Perlecan-deficient murine embryonic stem cells were used to investigate the myofibrillar network and the electrophysiological properties of single cardiomyocytes. The mechanical stability of the developing perlecan-deficient mouse hearts was analysed by microinjecting fluorescent-labelled dextran. Maturation and formation of basement membranes and cell-cell contacts were investigated by electron microscopy, immunohistochemistry, and western blotting. Sarcomere formation and cellular functional properties were unaffected in perlecan-deficient cardiomyocytes. However, the intraventricular dye injection experiments revealed mechanical instability of the early embryonic mouse heart muscle wall before embryonic day 10.5 (E10.5). Accordingly, perlecan-null embryonic hearts contained lower amounts of the critical basement membrane components, collagen IV and laminins. Furthermore, basement membranes were absent in perlecan-null cardiomoycytes whereas adherens junctions formed and matured around E9.5. Infarcted hearts from perlecan heterozygous mice displayed reduced heart function when compared with wild-type hearts. We propose that perlecan plays an important role in maintaining the integrity during cardiac development and is important for heart function in the adult heart after injury.
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| 14. |
- Witasp, Erika, et al.
(författare)
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Vitamin D fails to prevent serum starvation- or staurosporine-induced apoptosis in human and rat osteosarcoma-derived cell lines
- 2005
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Ingår i: Biochemical and Biophysical Research Communications - BBRC. - : Elsevier BV. - 0006-291X .- 1090-2104. ; 330:3, s. 891-897
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies have suggested that 1,25(OH)2D3, the active form of vitamin D3, may increase the survival of bone-forming osteoblasts through an inhibition of apoptosis. On the other hand, vitamin D3 has also been shown to trigger apoptosis in human cancer cells, including osteosarcoma-derived cell lines. In the present study, we show that 1,25(OH)2D3 induces a time- and dose-dependent loss of cell viability in the rat osteosarcoma cell line, UMR-106, and the human osteosarcoma cell line, TE-85. We were unable, however, to detect nuclear condensation, phosphatidylserine externalization, or other typical signs of apoptosis in this model. Moreover, 1,25(OH)2D3 failed to protect against apoptosis induced by serum starvation or incubation with the protein kinase inhibitor, staurosporine. These in vitro findings are thus at variance with several previous reports in the literature and suggest that induction of or protection against apoptosis of bone-derived cells may not be a primary function of vitamin D3.
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| 15. |
- Zeisberg, Elisabeth M., et al.
(författare)
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Endothelial-to-mesenchymal transition contributes to cardiac fibrosis
- 2007
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Ingår i: Nature Medicine. - : Springer Science and Business Media LLC. - 1546-170X .- 1078-8956. ; 13:8, s. 952-961
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Tidskriftsartikel (refereegranskat)abstract
- Cardiac fibrosis, associated with a decreased extent of microvasculature and with disruption of normal myocardial structures, results from excessive deposition of extracellular matrix, which is mediated by the recruitment of fibroblasts. The source of these fibroblasts is unclear and specific anti-fibrotic therapies are not currently available. Here we show that cardiac fibrosis is associated with the emergence of fibroblasts originating from endothelial cells, suggesting an endothelial-mesenchymal transition (EndMT) similar to events that occur during formation of the atrioventricular cushion in the embryonic heart. Transforming growth factor-beta 1 (TGF-beta 1) induced endothelial cells to undergo EndMT, whereas bone morphogenic protein 7 (BMP-7) preserved the endothelial phenotype. The systemic administration of recombinant human BMP-7 (rhBMP-7) significantly inhibited EndMT and the progression of cardiac fibrosis in mouse models of pressure overload and chronic allograft rejection. Our findings show that EndMT contributes to the progression of cardiac fibrosis and that rhBMP-7 can be used to inhibit EndMT and to intervene in the progression of chronic heart disease associated with fibrosis.
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