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Jakob Triebel

Jakob Triebel
Klinikum Nürnberg · Institut für Klinische Chemie, Laboratoriumsmedizin und Transfusionsmedizin

MD

About

73
Publications
10,624
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639
Citations
Citations since 2017
35 Research Items
530 Citations
2017201820192020202120222023050100150
2017201820192020202120222023050100150
2017201820192020202120222023050100150
2017201820192020202120222023050100150
Introduction
Jakob Triebel is Medical Doctor and Associate Professor for experimental pathobiochemistry at the University Institute for Clinical Chemistry, Laboratory Medicine and Transfusion Medicine (Head: Professor Dr. Thomas Bertsch) of the General Hospital Nuremberg and the Paracelsus Medical University Nuremberg.
Additional affiliations
April 2014 - present
Nuremberg General Hospital & Paracelsus Medical University, Nuremberg, Germany
Position
  • Clinical Chemistry
April 2013 - September 2013
University of Greifswald
Position
  • Internal Medicine
February 2011 - February 2013
Universidad Nacional Autónoma de México
Position
  • PostDoc Position
Education
November 2019 - October 2021
February 2011 - February 2013
February 2001 - June 2007

Publications

Publications (73)
Article
Full-text available
The hormonal family of vasoinhibins, which derive from the anterior pituitary hormone prolactin, are known for their inhibiting effects on blood vessel growth, vasopermeability, and vasodilation. As pleiotropic hormones, vasoinhibins act in multiple target organs and tissues. The generation, secretion, and regulation of vasoinhibins are embedded in...
Article
Full-text available
Hormonal factors impacting the vascular adaptions of the uteroplacental unit in non-complicated and complicated pregnancies are of interest. Here, 4 human placentas from women with and without preeclampsia were investigated for the presence of placental lactogen derived, antiangiogenic vasoinhibin. Western blotting and mass spectrometry of placenta...
Article
Full-text available
Proteolysis of protein hormones is primarily acknowledged in the context of breakdown and metabolic clearance by hepatorenal elimination. However, less explored is the specific proteolytic processing of large protein hormones, for which canonical signaling pathways were already established [e.g., prolactin (PRL)], to generate unique messengers that...
Article
Full-text available
The immune modulatory effects of vitamin D and the impact of vitamin D deficiency on various diseases are a subject of current scientific research. However, there are few data directly linking vitamin D to hard endpoints in clinical studies, apart from its well-known effects on bone health. It is therefore of interest, that the effectiveness of the...
Article
Full-text available
Diabetic retinopathy (DR) and diabetic macular edema (DME) are major causes for visual loss in adults. Nearly half of the world's population with diabetes has some degree of DR, and DME is a major cause of visual impairment in these patients. Severe vision loss occurs because of tractional retinal detachment due to retinal neovascularization, but t...
Article
Full-text available
Introduction: Both increased activity of the complement system (CS) and the role of the pituitary hormone prolactin (PRL) are implicated in osteoarthritis (OA) pathogenesis. Besides, Cathepsin D (CatD) activity is increased in the context of OA and can exert not only proteolytic but also non-proteolytic effects on cells. For the first time, possib...
Data
Vasoinhibin is a pleiotropic protein hormone with endocrine, autocrine, and paracrine effects on blood vessel growth, permeability, and dilation, and a role in several human diseases. It is generated by proteolytic cleavage of the pituitary hormone prolactin by cathepsin D. Several isoforms with a variation in the number of amino acids and correspo...
Article
Full-text available
Vasoinhibin is a pleiotropic protein hormone with endocrine, autocrine, and paracrine effects on blood vessel growth, permeability, and dilation, and a role in several human diseases. It is generated by proteolytic cleavage of the pituitary hormone prolactin by cathepsin D. Several isoforms with a variation in the number of amino acids and correspo...
Article
Full-text available
The hormone prolactin acquires antiangiogenic and antivasopermeability properties after undergoing proteolytic cleavage to vasoinhibin, an endogenous prolactin fragment of 123 or more amino acids that inhibits the action of multiple proangiogenic factors. Preclinical and clinical evidence supports the therapeutic potential of vasoinhibin against an...
Article
Excessive vasopermeability and angiogenesis compromise vision in diabetic macular edema (DME) and diabetic retinopathy (DR). Vasoinhibin is a fragment of the hormone prolactin (PRL) that inhibits diabetes-induced retinal hyper-vasopermeability and ischemia-induced retinal angiogenesis in rodents. Hyperprolactinemia generated by the dopamine D2 rece...
Article
Full-text available
BACKGROUND The evaluation of low abundance biomarkers in the circulating low molecular weight serum proteome is an important source of information. Techniques for sample preparation to remove high abundant proteins and to enrich the low molecular weight fraction are usually required prior to novel biomarker detection. METHODS A continuous elution...
Article
Full-text available
Vasoinhibin is an antiangiogenic, profibrinolytic peptide generated by the proteolytic cleavage of the pituitary hormone prolactin by cathepsin D, matrix metalloproteinases, and bone morphogenetic protein-1. Vasoinhibin can also be generated when placental lactogen or growth hormone are enzymatically cleaved. Here, it is investigated whether plasmi...
Article
Vasoinhibin is an endogenous prolactin (PRL) fragment with pro-fibrinolytic, anti-vasopermeability, and anti-angiogenic effects. The fact that blood clotting, vascular permeability, and angiogenesis are functionally linked during the wound healing process led us to investigate whether thrombin, a major protease in tissue repair, generates vasoinhib...
Article
Full-text available
Vasoinhibin is a protein hormone with antiangiogenic, antivasodilatatory, and antivasopermeability effects generated by the proteolytic cleavage of prolactin. The discovery of its role in diabetic retinopathy and peripartum cardiomyopathy led to the evaluation of new pharmacological treatments in clinical interventional trials. However, the quantit...
Article
Full-text available
Vasoinhibin, historically also known as 16K PRL, is a peptide hormone with antiangiogenic, antivasodilatatory, and antivasopermeability effects generated by proteolytic cleavage of prolactin (PRL). The discovery of its role in diabetic retinopathy and peripartum cardiomyopathy led to the development of new pharmacological treatments and their evalu...
Article
Full-text available
Purpose: High circulating levels of the hormone prolactin (PRL) protect against experimental diabetic retinopathy (DR) due to the retinal accumulation of vasoinhibin, a PRL fragment that inhibits blood vessel permeability and growth. A phase 2 clinical trial is investigating a new therapy for DR based on elevating serum PRL levels with levosulpiri...
Article
Full-text available
Background: Vasoinhibin is generated in the pituitary gland and in multiple target tissues by proteolytic cleavage of prolactin by matrix metalloproteinases and cathepsin D. A dysregulation of vasoinhibin generation appears to contribute to diabetic retinopathy and diabetic macular edema, retinopathy of prematurity, peripartum cardiomyopathy, and...
Article
The pituitary hormone prolactin (PRL) regulates a variety of functions beyond reproduction. The association between physiological (pregnancy) and pathological (prolactinoma) hyperprolactinemia and metabolic alterations led to the concept of this hormone being diabetogenic. However, large cohort clinical studies have recently shown that low circulat...
Article
Full-text available
Preeclampsia is a hypertensive disorder affecting 3–5% of all pregnancies. The only curative treatment is delivery of the placenta and the pathophysiology is poorly understood. Studies have demonstrated altered levels of antiangiogenic factors in patients with preeclampsia. One such factor is the antiangiogenic and antivasodilatatory peptide hormon...
Article
Tumor antigen-targeting monoclonal antibodies (mAbs) are an important element of current cancer therapies. Some of these therapeutic mAbs enable antibody-dependent cell mediated cytotoxicity (ADCC) against tumor cells. However, cancer-related functional impairment of immune effector cells may limit the clinical efficacy of antibody treatments. We r...
Article
Full-text available
Public databases contain a rapidly expanding amount of information about protein sequences of diverse species, genetic mutations in humans, as well as enzymes and their substrates. This opens new possibilities of data analysis, hypothesis generation, and testing. It is the purpose of the present article to briefly highlight two exemplary analyses w...
Article
Full-text available
Proteolytic cleavage of prolactin (PRL), the human anterior pituitary hormone fundamental for lactation can generate vasoinhibin, a peptide-hormone with endocrine, paracrine, and autocrine effects not shared with its precursor. Vasoinhibin effects include the regulation of blood vessel growth, permeability, and dilation (1, 2), and non-vascular eff...
Article
Full-text available
Vasoinhibin belongs to a family of angiogenesis inhibitors generated when the fourth α-helix (H4) of the hormone prolactin (PRL) is removed by specific proteolytic cleavage. The antiangiogenic properties are absent in uncleaved PRL, indicating that conformational changes create a new bioactive domain. However, the solution structure of vasoinhibin...
Poster
Monoclonal antibodies (mAb) are an important element of current cancer immunotherapy. But even though mAbs are highly antigen specific they often lack sufficient effectiveness as single agents. Activated gamma delta (γδ) T-cells on the other hand have powerful cytotoxic and broader tumor recognition capabilities. Additionally, γδ T-cells are potent...
Article
Full-text available
Background: Diabetic retinopathy (DR) and diabetic macular edema (DME) are potentially blinding, microvascular retinal diseases in people with diabetes mellitus. Preclinical studies support a protective role of the hormone prolactin due to its ocular incorporation and conversion to vasoinhibins, a family of prolactin fragments that inhibit ischemia...
Article
Full-text available
Accumulating evidence demonstrates that complement activation is involved in the pathogenesis of osteoarthritis (OA). However, the intimate complement regulation and cross talk with other signaling pathways in joint-associated tissues remain incompletely understood. Recent insights are summarized and discussed here, to put together a more comprehen...
Article
Full-text available
The left atrial appendage (LAA) represents both a predisposing source of thrombus formation and of neuro-humoral haemostasis. This study aims to evaluate changes of biomarker expression before and after successful percutaneous closure of the LAA. Patients with atrial fibrillation and contraindication for oral anticoagulant therapy were enrolled. Bl...
Article
Full-text available
The prolactin/vasoinhibin axis defines an endocrine system, in which prolactin and vasoinhibins regulate blood vessel growth and function, the secretion of other hormones, inflammatory and immune processes, coagulation, and behavior. The core element of the prolactin/vasoinhibin axis is the generation of vasoinhibins, which consists in the proteoly...
Article
Full-text available
Background A dysregulation of the generation of vasoinhibin hormones by proteolytic cleavage of prolactin has been brought into context with diabetic retinopathy, retinopathy of prematurity, preeclampsia, pregnancy-induced hypertension, and peripartum cardiomyopathy. Factors governing vasoinhibin generation are incompletely characterized, and the c...
Article
Full-text available
The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) lists the peripartum period as an onset specifier for major depressive disorder, where “peripartum period” is defined as the time of the “most recent episode during pregnancy as well as four weeks following delivery” (Diagnostic and Statistical Manual of Mental Disorders, 2013). In a...
Article
Full-text available
Wiedemann et al. report a case of a patient with peripartum cardiomyopathy (PPCM) and hyperprolactinemia who received a biventricular assist device and was treated with cabergoline. They conclude that patients with severe PPCM might benefit from treatment with cabergoline and suggest proactive testing of pregnant women for hyperprolactinemia and co...
Article
Full-text available
Chang et al. report the modulation of blood pressure by prolactin and one of its cleaved products, a 16 kDa vasoinhibin isoform also referred as 16 kDa prolactin (1). They use transgenic mice producing prolactin in the liver and show that overexpression of the prolactin transgene leads to higher circulating levels of the vasoinhibin, which upregula...
Article
BACKGROUND: Retinopathy of prematurity (ROP) is a potentially blinding, retinal neovascular disease. Systemic prolactin accesses the retina to regulate blood vessels. Prolactin is proangiogenic and can be cleaved to antiangiogenic vasoinhibins. We investigated whether circulating prolactin and vasoinhibins associate with incidence and progression o...
Article
Full-text available
Rheumatoid arthritis (RA) is a chronic, autoimmune, inflammatory disease destroying articular cartilage and bone. The female preponderance and the influence of reproductive states in RA have long linked this disease to sexually dimorphic, reproductive hormones such as prolactin (PRL). PRL has immune-enhancing properties and increases in the circula...
Poster
Full-text available
BACKGROUND The prolactin/vasoinhibin axis in humans features the generation, secretion, and actions of the pleiotropic pituitary hormones prolactin and vasoinhibins under control of the hypothalamus, the pituitary gland, and the target tissue microenvironment. Vasoinhibins are generated by proteolytic cleavage of full-length prolactin at various cl...
Conference Paper
Full-text available
Background: Full-length human prolactin (protein data bank identification P01236), the precursor of vasoinhibins, is structurally classified as a class-I helical cytokine with a four-helix bundle core and only a minimal degree of dark regions. Experimental data on the solution structure of vasoinhibins are not available. Methods: A recombinant, hum...
Conference Paper
Full-text available
Background: The prolactin/vasoinhibin axis constitutes a novel endocrine axis in which the generation, secretion, and actions of the pituitary hormones prolactin and vasoinhibins are under control of the hypothalamus, the pituitary gland, and of regulators in the target tissue microenvironment. Vasoinhibins are generated in the pituitary gland and...
Article
The C-reactive protein (CRP), first described as a serum component capable of precipitating the C-polysaccharide of pneumococci, is one of the most important proteins because the serum concentration rises in the acute phase reaction. The acute phase reaction is the nonspecific reaction of the body to noxious stimuli of the most varied kinds, such a...
Article
Full-text available
The metabolic clearance of prolactin (PRL) is partially executed by the kidney. Here, we investigate the urine excretion of PRL in patients with Diabetes Mellitus and renal impairment. Serum and urine samples were collected from male, mestizo patients in central Mexico employing a cross-sectional study design. Ninety-eight individuals had either no...
Article
Full-text available
Prolactin and growth hormone are produced in the anterior pituitary gland and secreted into the circulation to execute their diverse physiological effects. They are also produced at various extrapituitary sites. Apart from the traditional, well-known effects mediated by the full-length hormones, they serve as the source for vasoinhibins, which are...
Article
Full-text available
Background Meningoencephalitis caused by Escherichia coli is associated with high rates of mortality and risk of neurological sequelae in newborns and infants and in older or immunocompromised adults. A high prevalence of neurological disorders has been observed in geriatric populations at risk of hypovitaminosis D.Methods In vivo, we studied the e...
Article
Full-text available
Prolactin (PRL) stimulates the growth of new blood vessels (angiogenesis) either directly through actions on endothelial cells or indirectly by upregulating proangiogenic factors like vascular endothelial growth factor (VEGF). Moreover, PRL acquires antiangiogenic properties after undergoing proteolytic cleavage to vasoinhibins, a family of PRL fra...
Conference Paper
Full-text available
With preterm regression of the hyaloid vascular system, the human vitreous becomes devoid of blood vessels and maintains an avascular, transparent state throughout life. However, diseases of the developing and mature retina, such as retinopathy of prematurity or proliferative diabetic retinopathy (PDR), often result in the invasion of blood vessels...
Article
Full-text available
BRIEFE Gesundheitsversorgung: Falsche Erwartung Dtsch Arztebl 2014; 111(3): A-85 Triebel, Jakob; Krüger, Dominik Zu lange haben Nichtmediziner in der Gesundheitsökonomie Entscheidungen getroffen (DÄ 47/2013: „Medizin muss Kontrolle über sich selbst zurückgewinnen“ von Christian Thielscher). Der Schlussfolgerung von Herrn Thielscher, die Ärzte hät...
Article
Full-text available
Prolactin (PRL) is a potent liver mitogen and proangiogenic hormone. Here, we used hyperprolactinemic rats and PRL receptor null mice (PRLR(-/-)) to study the effect of PRL on liver growth and angiogenesis before and after partial hepatectomy (PH). Liver to body weight ratio (LBW), hepatocyte and sinusoidal endothelial cell (SEC) proliferation, and...
Article
Full-text available
Chondrocytes are the only cells in cartilage, and their death by apoptosis contributes to cartilage loss in inflammatory joint diseases, such as rheumatoid arthritis (RA). A putative therapeutic intervention for RA is the inhibition of apoptosis-mediated cartilage degradation. The hormone prolactin (PRL) frequently increases in the circulation of p...
Conference Paper
Full-text available
Vasoinhibins, a family of anti-angiogenic proteins derived by proteolytic cleavage from prolactin (PRL), prevent retinal angiogenesis and vasopermeability associated with experimental diabetic retinopathy. Here, we conducted a case-control study to determine the presence of vasoinhibins in human vitreous, to study whether their vitreal anti-angioge...
Conference Paper
Full-text available
Melanocortin receptors (MCRs) are known to be expressed predominantly in the brain where they exert metabolic and anti-inflammatory functions. Furthermore, the brain MCRs are supposed to also mediate anti-inflammatory effects in other organs. As serum levels of MCRs-ligands are elevated in clinical situation (acute-phase-response (APR)) of tissue d...
Data
Full-text available
Upper part: control rat liver section, Lower part: negative control without primary antibody (arrows indicate the MC4R-positive cells in the liver). Results show the representative picture of three animals and six slides per time point (original magnification ×200, scale bar 20 μm). (PDF 218 kb)
Data
Full-text available
Immunoprecipitation analysis of total protein of rat liver lysates by using antibody against MC4R demonstrates immunoreactive bands at 37 and 55 kDa. B Immunoprecipitation of the supernatants of the same samples. (PDF 80 kb)
Data
Upper part: control rat brain section, Lower part: negative control without primary antibody (arrowhead indicates the small cells (microglia) positive for MC4R and arrow indicates the large cells (macroglia) positive for MC4R in the brain). Results show the representative picture of three animals and six slides per time point (original magnificatio...
Article
Full-text available
MCRs are known to be expressed predominantly in the brain where they mediate metabolic and anti-inflammatory functions. Leptin plays an important role in appetite and energy regulation via signaling through melanocortin receptors (MCRs) in the brain. As serum levels of MCR ligands are elevated in a clinical situation [acute-phase response (APR)] to...
Article
Full-text available
Diabetic retinopathy is a disease of the retinal microvasculature that develops as a complication of diabetes mellitus and constitutes a major cause of blindness in adults of all ages. Diabetic retinopathy is characterized by the loss of capillary cells leading to increased vasopermeability, ischemia, and hypoxia that trigger the excessive formatio...
Article
Full-text available
As member of the defense system, liver is inextricably linked with the acute phase response (APR). On the other hand, liver cells may be the target of noxious material released from injured tissue or injuring agents.The melanocortin 4 receptor (MC4R) is known for the mediation of anti-inflammatory signals which controls the production of several pr...
Conference Paper
Full-text available
Analyse von 16K Prolaktin im Serum von Patienten mit diabetischer Retinopathie Einleitung: In vitro- und in vivo Studien haben gezeigt, dass das N-terminale 16kDa-Fragment des menschlichen Prolaktins (16K PRL) ein potenter Angiogenese-Inhibitor ist. 16K PRL gehört zu der Protein-Familie der Vasoinhibine, welche kürzlich als endogene Regulatoren der...
Article
Full-text available
In vitro experiments and in vivo studies on rodents demonstrate that N-terminal 14, 15, 16, 17, and 18 kDa fragments prolactin-related vasoinhibin (PRL-V) of human PRL are natural inhibitors of neovascularization in the retina and elsewhere. These N-terminal PRL fragments belong to a family of peptides named vasoinhibins, which act as endogenous re...
Article
To the Editor: Sasako and colleagues show that D2 lymphadenectomy plus PAND adds benefit with respect to overall 5-year survival only among patients with negative nodes. The authors also report that the number of patients with pathologically negative nodes was twice as high as that determined from clinical findings before surgery. How were the cli...
Article
Full-text available
Die in dem Artikel beschriebenen Umstände, unter denen ein Medizinstudent ärztliche Tätigkeiten ausüben darf und sollte, haben mit der alltäglichen Praxis eines Studenten in der Famulatur, im Blockpraktikum und im praktischen Jahr nichts zu tun. Allenfalls stellen sie eine Idealvorstellung dar, abgeleitet aus der Approbationsordnung für Ärzte und a...
Presentation
Full-text available
Rede anlässlich der Verabschiedung der Absolventen des Jahrgangs 2007 der Medizinischen Fakultät der Georg-August-Universität Göttingen

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Projects

Projects (6)
Project
To reconstruct the evolutionary history of the emergence of vasoinhibins throughout speciation.
Project
Goal of this project is to resolve the vasoinhibin (16K PRL) solution structure.