@article{DanquahDobruckyFranketal.2015,
  author    = {Danquah, Ina and Dobrucky, C. Lydia and Frank, Laura K. and Henze, Andrea and Amoako, Yaw A. and Bedu-Addo, George and Raila, Jens and Schulze, Matthias Bernd and Mockenhaupt, Frank P. and Schweigert, Florian J.},
  title     = {Vitamin A: potential misclassification of vitamin A status among patients with type 2 diabetes and hypertension in urban Ghana},
  series = {The American journal of clinical nutrition : a publication of the American Society for Nutrition, Inc.},
  volume    = {102},
  journal   = {The American journal of clinical nutrition : a publication of the American Society for Nutrition, Inc.},
  number    = {1},
  publisher = {American Society for Nutrition, Inc.},
  address   = {Bethesda},
  issn      = {0002-9165},
  doi       = {10.3945/ajcn.114.101345},
  pages     = {207 -- 214},
  year      = {2015},
  abstract  = {Background: Sub-Saharan Africa is facing a double burden of malnutrition: vitamin A deficiency (VAD) prevails, whereas the nutrition-related chronic conditions type 2 diabetes (T2D) and hypertension are emerging. Serum retinol a VAD marker increases in kidney disease and decreases in inflammation, which can partly be attributed to alterations in the vitamin A transport proteins retinol-binding protein 4 (RBP4) and prealbumin. Kidney dysfunction and inflammation commonly accompany T2D and hypertension. Objective: Among urban Ghanaians, we investigated the associations of T2D and hypertension with serum retinol as well as the importance of kidney function and inflammation in this regard. Design: A hospital-based, case-control study in individuals for risk factors of T2D, hypertension, or both was conducted in Kumasi, Ghana (328 controls, 197 with T2D, 354 with hypertension, and 340 with T2D plus hypertension). In 1219 blood samples, serum retinol, RBP4, and prealbumin were measured. Urinary albumin and estimated glomerular filtration rate (eGFR) defined kidney function. C-reactive protein (CRP) >5 mg/L indicated inflammation. We identified associations of T2D and hypertension with retinol by linear regression and calculated the contribution of RBP4, prealbumin, urinary albumin, eGFR, and CRP to these associations as the percentages of the explained variance of retinol. Results: VAD (retinol <1.05 mu mol/L) was present in 10\% of this predominantly female, middle-aged, overweight, and deprived population. Hypertension, but not T2D, was positively associated with retinol (beta: 0.12; 95\% CI: 0.08, 0,17), adjusted for age, sex, socioeconomic factors, anthropometric measurements, and lifestyle. In addition to RBP4 (72\%) and prealbumin (22\%), the effect of increased retinol on individuals with hypertension was mainly attributed to impaired kidney function (eGFR: 30\%; urinary albumin: 5\%) but not to inflammation. Conclusions: In patients with hypertension, VAD might be underestimated because of increased serum retinol in the context of kidney dysfunction. Thus, the interpretation of serum retinol in sub-Saharan Africa should account for hypertension status.},
  language  = {en}
}
@article{HenzeRailaKempfetal.2011,
  author    = {Henze, Andrea and Raila, Jens and Kempf, Caroline and Reinke, Petra and Sefrin, Anett and Querfeld, Uwe and Schweigert, Florian J.},
  title     = {Vitamin A metabolism is changed in donors after living-kidney transplantation an observational study},
  series = {Lipids in health and disease},
  volume    = {10},
  journal   = {Lipids in health and disease},
  number    = {23},
  publisher = {BioMed Central},
  address   = {London},
  issn      = {1476-511X},
  doi       = {10.1186/1476-511X-10-231},
  pages     = {7},
  year      = {2011},
  abstract  = {Background: The kidneys are essential for the metabolism of vitamin A (retinol) and its transport proteins retinol-binding protein 4 (RBP4) and transthyretin. Little is known about changes in serum concentration after living donor kidney transplantation (LDKT) as a consequence of unilateral nephrectomy; although an association of these parameters with the risk of cardiovascular diseases and insulin resistance has been suggested. Therefore we analyzed the concentration of retinol, RBP4, apoRBP4 and transthyretin in serum of 20 living-kidney donors and respective recipients at baseline as well as 6 weeks and 6 months after LDKT. Results: As a consequence of LDKT, the kidney function of recipients was improved while the kidney function of donors was moderately reduced within 6 weeks after LDKT. With regard to vitamin A metabolism, the recipients revealed higher levels of retinol, RBP4, transthyretin and apoRBP4 before LDKT in comparison to donors. After LDKT, the levels of all four parameters decreased in serum of the recipients, while retinol, RBP4 as well as apoRBP4 serum levels of donors increased and remained increased during the follow-up period of 6 months. Conclusion: LDKT is generally regarded as beneficial for allograft recipients and not particularly detrimental for the donors. However, it could be demonstrated in this study that a moderate reduction of kidney function by unilateral nephrectomy, resulted in an imbalance of components of vitamin A metabolism with a significant increase of retinol and RBP4 and apoRBP4 concentration in serum of donors.},
  language  = {en}
}
@misc{HenzeRailaKempfetal.2017,
  author    = {Henze, Andrea and Raila, Jens and Kempf, Caroline and Reinke, Petra and Sefrin, Anett and Querfeld, Uwe and Schweigert, Florian J.},
  title     = {Vitamin A metabolism is changed in donors after living-kidney transplantation},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-400942},
  pages     = {7},
  year      = {2017},
  abstract  = {Background The kidneys are essential for the metabolism of vitamin A (retinol) and its transport proteins retinol-binding protein 4 (RBP4) and transthyretin. Little is known about changes in serum concentration after living donor kidney transplantation (LDKT) as a consequence of unilateral nephrectomy; although an association of these parameters with the risk of cardiovascular diseases and insulin resistance has been suggested. Therefore we analyzed the concentration of retinol, RBP4, apoRBP4 and transthyretin in serum of 20 living-kidney donors and respective recipients at baseline as well as 6 weeks and 6 months after LDKT. Results As a consequence of LDKT, the kidney function of recipients was improved while the kidney function of donors was moderately reduced within 6 weeks after LDKT. With regard to vitamin A metabolism, the recipients revealed higher levels of retinol, RBP4, transthyretin and apoRBP4 before LDKT in comparison to donors. After LDKT, the levels of all four parameters decreased in serum of the recipients, while retinol, RBP4 as well as apoRBP4 serum levels of donors increased and remained increased during the follow-up period of 6 months. Conclusion LDKT is generally regarded as beneficial for allograft recipients and not particularly detrimental for the donors. However, it could be demonstrated in this study that a moderate reduction of kidney function by unilateral nephrectomy, resulted in an imbalance of components of vitamin A metabolism with a significant increase of retinol and RBP4 and apoRBP4 concentration in serum of donors.},
  language  = {en}
}
@article{HenzeEspeWanneretal.2012,
  author    = {Henze, Andrea and Espe, Katharina M. and Wanner, Christoph and Krane, Vera and Raila, Jens and Hocher, Berthold and Schweigert, Florian J. and Drechsler, Christiane},
  title     = {Transthyretin predicts cardiovascular outcome in hemodialysis patients with type 2 diabetes},
  series = {Diabetes care},
  volume    = {35},
  journal   = {Diabetes care},
  number    = {11},
  publisher = {American Diabetes Association},
  address   = {Alexandria},
  issn      = {0149-5992},
  doi       = {10.2337/dc12-0455},
  pages     = {2365 -- 2372},
  year      = {2012},
  abstract  = {OBJECTIVE-BMI and albumin are commonly accepted parameters to recognize wasting in dialysis patients and are powerful predictors of morbidity and mortality. However, both parameters reveal limitations and may not cover the entire range of patients with wasting. The visceral protein transthyretin (TTR) may be helpful in overcoming the diagnostic and prognostic gap. Therefore, the aim of this study was to assess the association of TTR with morbidity and mortality in hemodialysis patients. RESEARCH DESIGN AND METHODS-The TTR concentration was determined in plasma samples of 1,177 hemodialysis patients with type 2 diabetes. Cox regression analyses were used to determine hazard ratios (HRs) for the risk of cardiovascular end points (CVEs) and mortality according to quartiles of TTR concentration for the total study cohort and the subgroups BMI >= 23 kg/m(2), albumin concentration >= 3.8 g/dL, and a combination of both. RESULTS-A low TTR concentration was associated with an increased risk for CVE for the total study cohort (HR 1.65 [95\% CI 1.27-2.14]), patients with BMI >= 23 kg/m(2) (1.70 [1.22-2.37]), albumin >= 3.8 g/dL (1.68 [1.17-2.42]), and the combination of both (1.69 [1.13-2.53]). Additionally, a low TTR concentration predicted mortality for the total study cohort (1.79 [1.43-2.24]) and patients with BMI >= 23 kg/m(2) (1.46 [1.09-1.95]). CONCLUSIONS-The current study demonstrated that TTR is a useful predictor for cardiovascular outcome and mortality in diabetic hemodialysis patients. TTR was particularly useful in patients who were not identified to be at risk by BMI or albumin status.},
  language  = {en}
}
@article{DoellDjalaliFarahaniKofoetZrenneretal.2021,
  author    = {D{\"o}ll, Stefanie and Djalali Farahani-Kofoet, Roxana and Zrenner, Rita and Henze, Andrea and Witzel, Katja},
  title     = {Tissue-specific signatures of metabolites and proteins in asparagus roots and exudates},
  series = {Horticulture research},
  volume    = {8},
  journal   = {Horticulture research},
  number    = {1},
  publisher = {Nanjing Agricultural Univ.},
  address   = {Nanjing},
  issn      = {2052-7276},
  doi       = {10.1038/s41438-021-00510-5},
  pages     = {14},
  year      = {2021},
  abstract  = {Comprehensive untargeted and targeted analysis of root exudate composition has advanced our understanding of rhizosphere processes. However, little is known about exudate spatial distribution and regulation. We studied the specific metabolite signatures of asparagus root exudates, root outer (epidermis and exodermis), and root inner tissues (cortex and vasculature). The greatest differences were found between exudates and root tissues. In total, 263 non-redundant metabolites were identified as significantly differentially abundant between the three root fractions, with the majority being enriched in the root exudate and/or outer tissue and annotated as 'lipids and lipid-like molecules' or 'phenylpropanoids and polyketides'. Spatial distribution was verified for three selected compounds using MALDI-TOF mass spectrometry imaging. Tissue-specific proteome analysis related root tissue-specific metabolite distributions and rhizodeposition with underlying biosynthetic pathways and transport mechanisms. The proteomes of root outer and inner tissues were spatially very distinct, in agreement with the fundamental differences between their functions and structures. According to KEGG pathway analysis, the outer tissue proteome was characterized by a high abundance of proteins related to 'lipid metabolism', 'biosynthesis of other secondary metabolites' and 'transport and catabolism', reflecting its main functions of providing a hydrophobic barrier, secreting secondary metabolites, and mediating water and nutrient uptake. Proteins more abundant in the inner tissue related to 'transcription', 'translation' and 'folding, sorting and degradation', in accord with the high activity of cortical and vasculature cell layers in growth- and development-related processes. In summary, asparagus root fractions accumulate specific metabolites. This expands our knowledge of tissue-specific plant cell function.},
  language  = {en}
}
@article{ReegJungCastroetal.2016,
  author    = {Reeg, Sandra and Jung, Tobias and Castro, Jos{\´e} Pedro and Davies, Kelvin J. A. and Henze, Andrea and Grune, Tilman},
  title     = {The molecular chaperone Hsp70 promotes the proteolytic removal of oxidatively damaged proteins by the proteasome},
  series = {Free radical biology and medicine : the official journal of the Oxygen Society, a constituent member of the International Society for Free Radical Research},
  volume    = {99},
  journal   = {Free radical biology and medicine : the official journal of the Oxygen Society, a constituent member of the International Society for Free Radical Research},
  publisher = {Elsevier},
  address   = {New York},
  issn      = {0891-5849},
  doi       = {10.1016/j.freeradbiomed.2016.08.002},
  pages     = {153 -- 166},
  year      = {2016},
  abstract  = {One hallmark of aging is the accumulation of protein aggregates, promoted by the unfolding of oxidized proteins. Unraveling the mechanism by which oxidized proteins are degraded may provide a basis to delay the early onset of features, such as protein aggregate formation, that contribute to the aging phenotype. In order to prevent aggregation of oxidized proteins, cells recur to the 20S proteasome, an efficient turnover proteolysis complex. It has previously been shown that upon oxidative stress the 26S proteasome, another form, dissociates into the 20S form. A critical player implicated in its dissociation is the Heat Shock Protein 70 (Hsp70), which promotes an increase in free 20S proteasome and, therefore, an increased capability to degrade oxidized proteins. The aim of this study was to test whether or not Hsp70 is involved in cooperating with the 20S proteasome for a selective degradation of oxidatively damaged proteins. Our results demonstrate that Hsp70 expression is induced in HT22 cells as a result of mild oxidative stress conditions. Furthermore, Hsp70 prevents the accumulation of oxidized proteins and directly promotes their degradation by the 20S proteasome. In contrast the expression of the Heat shock cognate protein 70 (Hsc70) was not changed in recovery after oxidative stress and Hsc70 has no influence on the removal of oxidatively damaged proteins. We were able to demonstrate in HT22 cells, in brain homogenates from 129/SV mice and in vitro, that there is an increased interaction of Hsp70 with oxidized proteins, but also with the 20S proteasome, indicating a role of Hsp70 in mediating the interaction of oxidized proteins with the 20S proteasome. Thus, our data clearly implicate an involvement of Hsp70 oxidatively damaged protein degradation by the 20S proteasome. c) 2016 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).},
  language  = {en}
}
@article{FredeHenzeKhaliletal.2014,
  author    = {Frede, Katja and Henze, Andrea and Khalil, Mahmoud and Baldermann, Susanne and Schweigert, Florian J. and Rawel, Harshadrai Manilal},
  title     = {Stability and cellular uptake of lutein-loaded emulsions},
  series = {Journal of functional food},
  volume    = {8},
  journal   = {Journal of functional food},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1756-4646},
  doi       = {10.1016/j.jff.2014.03.011},
  pages     = {118 -- 127},
  year      = {2014},
  abstract  = {The carotenoid lutein can improve human health. Since only a fraction is absorbed from food, lutein supplementation might be recommended. Emulsions could be good carrier systems to improve the bioavailability of lutein. Six different emulsifier compositions were used in this study to prepare lutein-loaded emulsions: beta-lactoglobulin, beta-lactoglobulin/lecithin, Biozate 1, Biozate 1/lecithin, Been 20 and Tween 20/lecithin. The droplet size, resistance to creaming, lutein stability, cytotoxicity and lutein uptake by HT29 cells were investigated. The whey protein beta-lactoglobulin, the whey protein hydrolysate Biozate 1 and the combination with lecithin brought the most promising results. The small droplet sizes and resistance to creaming were an indication of physical stable emulsions. Furthermore, these emulsifiers prevented oxidation of lutein. The choice of emulsifier had a strong impact on the uptake by HT29 cells. The highest lutein absorption was observed with the combination of Biozate 1 and lecithin.},
  language  = {en}
}
@article{MuenznerTuviaDeutschmannetal.2013,
  author    = {M{\"u}nzner, Matthias and Tuvia, Neta and Deutschmann, Claudia and Witte, Nicole and Tolkachov, Alexander and Valai, Atijeh and Henze, Andrea and Sander, Leif E. and Raila, Jens and Schupp, Michael},
  title     = {Retinol-binding protein 4 and its membrane receptor STRA6 control adipogenesis by regulating cellular retinoid homeostasis and retinoic acid receptor alpha activity},
  series = {Molecular and cellular biology},
  volume    = {33},
  journal   = {Molecular and cellular biology},
  number    = {20},
  publisher = {American Society for Microbiology},
  address   = {Washington},
  issn      = {0270-7306},
  doi       = {10.1128/MCB.00221-13},
  pages     = {4068 -- 4082},
  year      = {2013},
  abstract  = {Retinoids are vitamin A (retinol) derivatives and complex regulators of adipogenesis by activating specific nuclear receptors, including the retinoic acid receptor (RAR) and retinoid X receptor (RXR). Circulating retinol-binding protein 4 (RBP4) and its membrane receptor STRA6 coordinate cellular retinol uptake. It is unknown whether retinol levels and the activity of RAR and RXR in adipocyte precursors are linked via RBP4/STRA6. Here, we show that STRA6 is expressed in precursor cells and, dictated by the apo-and holo-RBP4 isoforms, mediates bidirectional retinol transport that controls RAR alpha activity and subsequent adipocyte differentiation. Mobilization of retinoid stores in mice by inducing RBP4 secretion from the liver activated RAR alpha signaling in the precursor cell containing the stromal-vascular fraction of adipose tissue. Retinol-loaded holo-RBP4 blocked adipocyte differentiation of cultured precursors by activating RAR alpha. Remarkably, retinol-free apo-RBP4 triggered retinol efflux that reduced cellular retinoids, RAR alpha activity, and target gene expression and enhanced adipogenesis synergistically with ectopic STRA6. Thus, STRA6 in adipocyte precursor cells links nuclear RAR alpha activity to the circulating RBP4 isoforms, whose ratio in obese mice was shifted toward limiting the adipogenic potential of their precursors. This novel cross talk identifies a retinoldependent metabolic function of RBP4 that may have important implications for the treatment of obesity.},
  language  = {en}
}
@article{BobbertRailaSchwarzetal.2010,
  author    = {Bobbert, Thomas and Raila, Jens and Schwarz, Franziska and Mai, Knut and Henze, Andrea and Pfeiffer, Andreas F. H. and Schweigert, Florian J. and Spranger, Joachim},
  title     = {Relation between retinol, retinol-binding protein 4, transthyretin and carotid intima media thickness},
  issn      = {0021-9150},
  doi       = {10.1016/j.atherosclerosis.2010.07.063},
  year      = {2010},
  abstract  = {Objective: Retinol is transported in a complex with retinol-binding protein 4 (RBP4) and transthyretin (TTR) in the circulation. While retinol is associated with various cardiovascular risk factors, the relation between retinol, RBP4, TTR and carotid intima media thickness (IMT) has not been analysed yet. Methods: Retinol, RBP4 and TTR were measured in 96 individuals and their relation to mean and maximal IMT was determined. Results: Mean IMT correlated with RBP4 (r = 0.335, p < 0.001), retinol (r = -0.241, p = 0.043), RBP/TTR ratio (r = 0.254, p = 0.025) and retinol/RBP4 ratio (r = -0.549, p < 0.001). Adjustment for age, sex, BMI, blood pressure, HDL/total cholesterol ratio, triglyceride, diabetes and smoking revealed that the retinol/RBP4 ratio was strongly and independently associated with mean IMT. Similar results were found for maximal IMT, which included the measurement of plaques. Conclusion: The data support that the transport complex of vitamin A is associated with the IMT, an established parameter of atherosclerosis. Changes in RBP4 saturation with retinol may link renal dysfunction and insulin resistance to atherosclerosis.},
  language  = {en}
}
@misc{Henze2018,
  author    = {Henze, Andrea},
  title     = {Proteinoxidation als Indikator des Alterungsph{\"a}notyps und Target einer individualisierten Ern{\"a}hrungsintervention (ProAID)},
  series = {Ern{\"a}hrungs-Umschau : Forschung \& Praxis},
  volume    = {65},
  journal   = {Ern{\"a}hrungs-Umschau : Forschung \& Praxis},
  number    = {10},
  publisher = {Umschau-Zeitschriftenverl.},
  address   = {Frankfurt, Main},
  issn      = {0174-0008},
  pages     = {M566 -- M567},
  year      = {2018},
  abstract  = {Oxidative posttranslationale Modifikationen endogener Proteine werden v. a. durch reaktive Sauerstoff- und Stickstoffspezies (engl:. Reactive Oxygen Species, ROS, reactive nitrogen species, RNS) hervorgerufen und k{\"o}nnen sowohl reversibel (z. B. Disulfidbindungen) als auch irreversibel (z. B. Proteincarbonyle) erfolgen [1-3]. Lange wurde angenommen, dass oxidative posttranslationale Proteinmodifikationen (oxPTPM) nur von untergeordneter Bedeutung f{\"u}r den Metabolismus sind. Tats{\"a}chlich handelt es sich jedoch um einen physiologischen Prozess, der {\"u}ber die Modulation der Proteinstruktur auch die Proteinfunktion (z. B. Enzymaktivit{\"a}t, Stabilit{\"a}t) und somit zahlreiche Stoffwechselwege wie den Energiestoffwechsel, die Immunfunktion, die vaskul{\"a}re Funktion sowie Apoptose und Genexpression beeinflussen kann. Die Bildung von oxPTPM ist dabei hochreguliert und h{\"a}ngt u. a. von der Proteinstruktur, der Verf{\"u}gbarkeit von ROS und RNS sowie dem lokalen Mikromilieu der Zelle ab [2, 4].},
  language  = {de}
}