Turid Frahnow

Dr. Turid Frahnow

orcid

Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 February 2017 in Gastroenterology
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Journal Article
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MMMariya Markova
Mariya Markova
OPOlga Pivovarova
Olga Pivovarova
SHSilke Hornemann
Silke Hornemann
SSStephanie Sucher
Stephanie Sucher
TFTurid Frahnow
Turid Frahnow
APAndreas F.H. Pfeiffer
Andreas F.H. Pfeiffer

24 January 2019 in Nature Communications
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Journal Article
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XSXia Sheng
Xia Sheng
HNHatice Zeynep Nenseth
Hatice Zeynep Nenseth
SQSu Qu
Su Qu
OKOmer F. Kuzu
Omer F. Kuzu
TFTurid Frahnow
Turid Frahnow
FSFahri Saatcioglu
Fahri Saatcioglu
Activation of endoplasmic reticulum (ER) stress/the unfolded protein response (UPR) has been linked to cancer, but the molecular mechanisms are poorly understood and there is a paucity of reagents to translate this for cancer therapy. Here, we report that an IRE1α RNase-specific inhibitor, MKC8866, strongly inhibits prostate cancer (PCa) tumor growth as monotherapy in multiple preclinical models in mice and shows synergistic antitumor effects with current PCa drugs. Interestingly, global transcriptomic analysis reveal that IRE1α-XBP1s pathway activity is required for c-MYC signaling, one of the most highly activated oncogenic pathways in PCa. XBP1s is necessary for optimal c-MYC mRNA and protein expression, establishing, for the first time, a direct link between UPR and oncogene activation. In addition, an XBP1-specific gene expression signature is strongly associated with PCa prognosis. Our data establish IRE1α-XBP1s signaling as a central pathway in PCa and indicate that its targeting may offer novel treatment strategies.

1 May 2018 in Molecular Metabolism
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Journal Article
Open access
RSRita Schüler
Rita Schüler
NSNicole Seebeck
Nicole Seebeck
MOMartin A. Osterhoff
Martin A. Osterhoff
VWVeronica Witte
Veronica Witte
AFAgnes Flöel
Agnes Flöel
APAndreas F.H. Pfeiffer
Andreas F.H. Pfeiffer
Reduction of brain glucose transporter GLUT1 results in severe neurological dysfunction. VEGF is required to restore and maintain brain glucose uptake across the blood brain barrier via GLUT1, which was shown to be acutely diminished in response to a high fat diet (HFD) in mice. The genetic and HFD-related regulation and association of VEGF and GLUT1 (SLC2A1) in humans was investigated in the NUtriGenomic Analysis in Twins (NUGAT) study. 92 healthy and non-obese twins were standardized to a high-carbohydrate low-fat diet for 6 weeks before switched to a 6-week HFD under isocaloric conditions. Three clinical investigation days were conducted: after 6 weeks of low-fat diet and after 1 and 6 weeks of HFD. Serum VEGF and other cytokine levels were measured using ELISA. Gene expression in subcutaneous adipose tissue was assessed by quantitative Real-Time PCR. Genotyping was performed using microarray. The Auditory Verbal Learning Task was conducted to measure cognitive performance. In this human study, we showed that the environmental regulation of SLC2A1 expression and serum VEGF by HFD was inversely correlated and both factors showed strong heritability (>90%). In response to the HFD containing 45% fat, serum VEGF levels increased (P = 0.002) while SLC2A1 mRNA expression in adipose tissue decreased (P = 0.001). Higher BMI was additionally associated with lower SLC2A1 expression. AA-genotypes of the rs9472159 polymorphism, which explained ∼39% of the variation in circulating VEGF concentrations, showed significantly reduced serum VEGF levels (P = 6.4 × 10-11) but higher SLC2A1 expression (P = 0.009) in adipose tissue compared to CC/CA-genotypes after 6 weeks of HFD. Memory performance in AA-genotypes declined in response to the HFD compared to CC- and CA-genotypes. The results provide evidence to suggest the translatability of the dietary regulation of VEGF and GLUT1 from mouse models to humans. Our data demonstrate that HFD induces a genetically determined and correlated decrease of GLUT1 and increase of VEGF which may affect memory performance. NCT01631123.

11 January 2017 in Journal of the American Heart Association
Verified
Journal Article
Open access
RSRita Schüler
Rita Schüler
MOMartin A. Osterhoff
Martin A. Osterhoff
TFTurid Frahnow
Turid Frahnow
ASAnne‐Cathrin Seltmann
Anne‐Cathrin Seltmann
ABAndreas Busjahn
Andreas Busjahn
APAndreas F.H. Pfeiffer
Andreas F.H. Pfeiffer
Background: Angiotensin‐converting enzyme ( ACE ) plays a major role in blood pressure regulation and cardiovascular homeostasis. Contrary to the assumption that ACE levels are stable, circulating ACE has been shown to be altered in obesity and weight loss. We sought to examine effects of a high‐saturated‐fat ( HF ) diet on ACE within the NU triGenomic Analysis in Twins ( NUGAT ) study. Methods and Results: Forty‐six healthy and nonobese twin pairs initially consumed a carbohydrate‐rich, low‐fat diet over a period of 6 weeks to standardize for nutritional behavior prior to the study, followed by 6 weeks of HF diet under isocaloric conditions. After 6 weeks of HF diet, circulating ACE concentrations increased by 15% ( P =1.6×10 −30 ), accompanied by an increased ACE gene expression in adipose tissue ( P =3.8×10 −6 ). Stratification by ACE rs4343, a proxy for the ACE insertion/deletion polymorphism (I/D), revealed that homozygous carriers ( GG ) of the variant had higher baseline ACE concentrations ( P =7.5×10 −8 ) and additionally showed a 2‐fold increase in ACE concentrations in response to the HF diet as compared to non‐ or heterozygous carriers ( AA / AG , P =2×10 −6 ). GG carriers also responded with higher systolic blood pressure as compared to AA / AG carriers ( P= 0.008). The strong gene‐diet interaction was confirmed in a second independent, cross‐sectional cohort, the Metabolic Syndrome Berlin Potsdam (MeSyBePo) study. Conclusions: The HF ‐diet‐induced increase of ACE serum concentrations reveals ACE to be a potential molecular link between dietary fat intake and hypertension and cardiovascular disease ( CVD ). The GG genotype of the ACE rs4343 polymorphism represents a robust nutrigenetic marker for an unfavorable response to high‐saturated‐fat diets. Clinical Trial Registration: URL : http://www.clinicaltrials.gov . Unique identifier: NCT 01631123.

MPMichael Pritsch
Michael Pritsch
KRKatja Radon
Katja Radon
ABAbhishek Bakuli
Abhishek Bakuli
RGRonan Le Gleut
Ronan Le Gleut
LOLaura Olbrich
Laura Olbrich
OGon behalf of the KoCo19 study group
on behalf of the KoCo19 study group
Given the large number of mild or asymptomatic SARS-CoV-2 cases, only population-based studies can provide reliable estimates of the magnitude of the pandemic. We therefore aimed to assess the sero-prevalence of SARS-CoV-2 in the Munich general population after the first wave of the pandemic. For this purpose, we drew a representative sample of 2994 private households and invited household members 14 years and older to complete questionnaires and to provide blood samples. SARS-CoV-2 seropositivity was defined as Roche N pan-Ig ≥ 0.4218. We adjusted the prevalence for the sampling design, sensitivity, and specificity. We investigated risk factors for SARS-CoV-2 seropositivity and geospatial transmission patterns by generalized linear mixed models and permutation tests. Seropositivity for SARS-CoV-2-specific antibodies was 1.82% (95% confidence interval (CI) 1.28–2.37%) as compared to 0.46% PCR-positive cases officially registered in Munich. Loss of the sense of smell or taste was associated with seropositivity (odds ratio (OR) 47.4; 95% CI 7.2–307.0) and infections clustered within households. By this first population-based study on SARS-CoV-2 prevalence in a large German municipality not affected by a superspreading event, we could show that at least one in four cases in private households was reported and known to the health authorities. These results will help authorities to estimate the true burden of disease in the population and to take evidence-based decisions on public health measures.

16 June 2017 in Scientific Reports
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Journal Article
Open access
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TFTurid Frahnow
Turid Frahnow
MOMartin A. Osterhoff
Martin A. Osterhoff
SHSilke Hornemann
Silke Hornemann
MKMichael Kruse
Michael Kruse
MSMichal A. Surma
Michal A. Surma
APAndreas F.H. Pfeiffer
Andreas F.H. Pfeiffer
Lipidomics have a great potential as clinical tool for monitoring metabolic changes in health and disease. Nevertheless hardly anything is known about the heritability of lipids. Therefore, it is necessary to clarify how and how much we can affect these progresses in individuals. In our interventional twin study (46 healthy, non-obese twin pairs) we investigated the lipid profile in plasma samples after switching from a low fat diet to an isocaloric high fat diet (HFD) to characterize the metabolic adaptation. Additionally we used the ACE model for Additive genetics, Common and unique Environment as well as linear mixed modelling to analyse the heritability of lipids. The heritability of lipids varied between 0–62% and applied to lipid species rather than to lipid classes. Phospholipids showed the highest inheritance. In addition, sex, body mass index (BMI) and age were important modifiers. The lipid profile changed already after one week of HFD and diverged further after 5 weeks of additional HFD. Basal concentrations of specific lipids within phospholipids are strongly inherited and are likely to be associated with heritable disease risks. BMI, sex and age were major modifiers. Nutrition strongly alters specific lipid classes, and has to be controlled in clinical association studies.