Ani Stoyanova

Dr. Ani Stoyanova

Charite, Berlin, Germany
orcid

Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

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

Representative Publications

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1 April 2015 in Cell
Verified
Journal Article
Closed access
NSNidhi Sahni
Nidhi Sahni
SYSong Yi
Song Yi
MTMikko Taipale
Mikko Taipale
JBJuan I. Fuxman Bass
Juan I. Fuxman Bass
JCJasmin Coulombe-Huntington
Jasmin Coulombe-Huntington
MVMarc Vidal
Marc Vidal

10 December 2019 in Nature Communications
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Journal Article
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JZJörn F. Ziegler
Jörn F. Ziegler
CBChotima Böttcher
Chotima Böttcher
MLMarilena Letizia
Marilena Letizia
CYCansu Yerinde
Cansu Yerinde
HWHao Wu
Hao Wu
CWCarl Weidinger
Carl Weidinger
Leptin has been shown to modulate intestinal inflammation in mice. However, clinical evidence regarding its immune-stimulatory potential in human Crohn’s disease remains sparse. We here describe a patient with the unique combination of acquired generalized lipodystrophy and Crohn’s disease (AGLCD) featuring a lack of adipose tissue, leptin deficiency and intestinal inflammation. Using mass and flow cytometry, immunohistochemistry and functional metabolic analyses, the AGLCD patient was compared to healthy individuals and Crohn’s disease patients regarding immune cell composition, function and metabolism and the effects of recombinant N-methionylleptin (rLeptin) were evaluated. We provide evidence that rLeptin exerts diverse pro-inflammatory effects on immune cell differentiation and function, including the metabolic reprogramming of immune cells and the induction of TNFα, ultimately aggravating Crohn’s disease in the AGLCD patient, which can be reversed by anti-TNFα therapy. Our results indicate that leptin is required for human immune homeostasis and contributes to autoimmunity in a TNFα-dependent manner.

13 August 2019 in Cancers
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Journal Article
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KBKatharina Beyer
Katharina Beyer
ABAnn-Kathrin Berg
Ann-Kathrin Berg
ASAni Stoyanova
Ani Stoyanova
Carsten KamphuesCarsten Kamphues
Carsten Kamphues
ASArne Sattler
Arne Sattler
KKKatja Kotsch
Katja Kotsch
Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a member of the TNF superfamily. TRAIL has historically been distinct from the Fas ligand and TNFα in terms of selective apoptosis induction in tumor cells and has a nearly non-existent systemic toxicity. Consequently, in the search for an ideal drug for tumor therapy, TRAIL rapidly drew interest, promising effective tumor control with minimal side effects. However, euphoria gave way to disillusionment as it turned out that carcinoma cells possess or can acquire resistance to TRAIL-induced apoptosis. Additionally, studies on models of inflammation and autoimmunity revealed that TRAIL can influence immune cells in many different ways. While TRAIL was initially found to be an important player in tumor defense by natural killer cells or cytotoxic T cells, additional effects of TRAIL on regulatory T cells and effector T cells, as well as on neutrophilic granulocytes and antigen-presenting cells, became focuses of interest. The tumor-promoting effects of these interactions become particularly important for consideration in cases where tumors are resistant to TRAIL-induced apoptosis. Consequently, murine models have shown that TRAIL can impair the tumor microenvironment toward a more immunosuppressive type, thereby promoting tumor growth. This review summarizes the current state of knowledge on TRAIL’s interactions with the immune system in the context of cancer.

15 March 2023 in Cancers
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Journal Article
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ABAnn-Kathrin Berg
Ann-Kathrin Berg
EHElisabeth M. Hahn
Elisabeth M. Hahn
FSFiona Speichinger-Hillenberg
Fiona Speichinger-Hillenberg
AGAnnemaria Silvana Grube
Annemaria Silvana Grube
NHNina Hering
Nina Hering
KBKatharina Beyer
Katharina Beyer
Despite intensive scientific efforts, the therapy of peritonitis is presently limited to symptomatic measures, including infectious source control and broad-spectrum antibiotics. Promising therapeutic approaches to reduce morbidity and mortality are still missing. Within the early phase of abdominal sepsis, apoptosis of neutrophil granulocytes is inhibited, which is linked to tissue damage and septic shock. TNF-related apoptosis-inducing ligand (TRAIL) is a promising agent to stimulate neutrophil apoptosis. However, the underlying mechanisms have not been elucidated so far. The objective of the present study was to characterize the molecular mechanisms of TRAIL-stimulated apoptosis in early abdominal sepsis. Therefore, the murine sepsis model Colon ascendens stent peritonitis (CASP) was applied in wild type (WT) and TRAIL knock-out (TRAIL–/–) C57/BL6j mice. Neutrophil granulocytes were isolated from spleen, blood, bone marrow, and peritoneal lavage using magnetic-activated cell sorting. Neutrophil maturation was analyzed by light microscopy, and apoptotic neutrophils were quantified by fluorescence-activated cell sorting (FACS). Western blot and FACS were used to investigate expression changes in apoptotic proteins and TRAIL receptors. The impact of TRAIL-induced apoptosis was studied in vitro. In septic mice (CASP 6 h), the number of neutrophils in the BM was reduced but increased in the blood and peritoneal lavage. This was paralleled by an increased maturation of neutrophils from rod-shaped to segmented neutrophils (right shift). In vitro, extrinsic TRAIL stimulation did not alter the apoptosis level of naïve neutrophils but stimulated apoptosis in neutrophils derived from septic WT and TRAIL–/– mice. Neutrophils of the bone marrow and spleen showed enhanced protein expression of anti-apoptotic Flip, c-IAP1, and McL-1 and reduced expression levels of pro-apoptotic Bax in neutrophils, which might correlate with apoptosis inhibition in these cells. CASP increased the expression of intrinsic TRAIL in neutrophils derived from the bone marrow and spleen. This might be explained by an increased expression of the TRAIL receptors DR5, DcR1, and DcR2 on neutrophils in sepsis. No differences were observed between septic or naïve WT and TRAIL–/– mice. In conclusion, the present study shows that neutrophil granulocytes are sensitive to TRAIL-stimulated apoptosis in the early stage of abdominal sepsis, emphasizing the promising role of TRAIL as a therapeutic agent.

31 May 2023 in International Journal of Colorectal Disease
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Journal Article
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FSFiona Speichinger
Fiona Speichinger
ABAnn-Kathrin Berg
Ann-Kathrin Berg
ASAni Stoyanova
Ani Stoyanova
IPIoannis Pozios
Ioannis Pozios
FLFlorian Nino Loch
Florian Nino Loch
CSChristian H.W. Schineis
Christian H.W. Schineis
Purpose: With the onset of the COVID pandemic in Germany in March 2020, far-reaching restrictions were imposed that limited medical access for patients. Screening examinations such as colonoscopies were greatly reduced in number. As rapid surgical triage after diagnosis is prognostic, our hypothesis was that pandemic-related delays would increase the proportion of advanced colon cancers with an overall sicker patient population. Methods: A total of 204 patients with initial diagnosis of colon cancer were analyzed in this retrospective single-center study between 03/01/2018 and 03/01/2022. Control group (111 patients, pre-COVID-19) and the study group (93 patients, during COVID-19) were compared in terms of tumor stages, surgical therapy, complications, and delays in the clinical setting. The data were presented either as absolute numbers or as median for constant data. Results: A trend towards more advanced tumor stages (T4a p = 0.067) and a significant increase of emergency surgeries (p = 0.016) with higher rates of ileus and perforation (p = 0.004) as well as discontinuity resections (p = 0.049) during the pandemic could be observed. Delays in surgical triage after endoscopic diagnosis were seen during the 2nd lockdown (02/11/20–26/12/20; p = 0.031). Conclusion: In summary, the results suggest delayed treatment during the COVID-19 pandemic, with the infection pattern of COVID appearing to have a major impact on the time between endoscopic diagnosis and surgical triage/surgery. Adequate care of colon cancer patients is possible even during a pandemic, but it is important to focus on structured screening and tight diagnosis to treatment schedules in order to prevent secondary pandemic victims.

12 November 2022 in Current Oncology
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ASAni Stoyanova
Ani Stoyanova
ABAnn-Kathrin Berg
Ann-Kathrin Berg
KBKatharina Beyer
Katharina Beyer
Robotic surgery is increasingly gaining importance. While initial results suggest an advantage of the robotic over the minimally invasive approach in patients with gastric cancer, definitive proof of its superiority has yet to be provided. There are numerous approaches to recreate a gastric reservoir after a total gastrectomy. However, a major disadvantage of most conventional reconstructions are long term effects such as dumping syndrome, afferent loop syndrome and poor nutrition intake with severe impact on the patient quality of life. The jejunal pouch reconstruction is a beneficial reconstruction, which provides a larger reservoir capacity after gastrectomy and prevents anastomotic stenosis and dumping syndrome. The completely intercorporeal approach with a Pfannenstiel incision instead of an unfavorable midline incision can potentially decrease delayed complications such as incision hernias. With the increased deployment of robotic surgery, a complete intercorporeal reconstruction is now possible without major increase in operating time or further technical weak points. We provide for the first time a detailed technical explanation of the completely intercorporeal robotic jejunal pouch reconstruction after gastrectomy.