Christoph Brenker

Christoph Brenker
University of Münster | WWU · Centre of Reproductive Medicine and Andrology

Phd

About

32
Publications
7,573
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2,296
Citations
Citations since 2017
21 Research Items
1594 Citations
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2017201820192020202120222023050100150200250300
2017201820192020202120222023050100150200250300

Publications

Publications (32)
Preprint
Cylicins are testis specific proteins which are exclusively expressed during spermiogenesis. In mice and humans, two Cylicins, the gonosomal X-linked Cylicin 1 (Cylc1/CYLC1) and the autosomal Cylicin 2 (Cylc2/CYLC2) genes have been identified. Cylicins are cytoskeletal proteins with an overall positive charge due to lysine-rich repeats. While Cylic...
Preprint
Cylicins are testis specific proteins which are exclusively expressed during spermiogenesis. In mice and humans, two Cylicins, the gonosomal X-linked Cylicin 1 (Cylc1/CYLC1) and the autosomal Cylicin 2 (Cylc2/CYLC2) genes have been identified. Cylicins are cytoskeletal proteins with an overall positive charge due to lysine-rich repeats. While Cylic...
Article
Full-text available
Primary Ciliary Dyskinesia (PCD) is a rare genetic disorder affecting the function of motile cilia in several organ systems. In PCD, male infertility is caused by defective sperm flagella composition or deficient motile cilia function in the efferent ducts of the male reproductive system. Different PCD-associated genes encoding axonemal components...
Preprint
Cylicins are testis specific proteins which are exclusively expressed during spermiogenesis. In mice and humans, two Cylicins, the gonosomal X-linked Cylicin 1 (Cylc1/CYLC1) and the autosomal Cylicin 2 (Cylc2/CYLC2) genes have been identified. Cylicins are cytoskeletal proteins with an overall positive charge due to lysine-rich repeats. While Cylic...
Article
The sperm-specific Ca2+ channel CatSper (cation channel of sperm) controls the intracellular Ca2+ concentration and, thereby, the swimming behavior of sperm from many species. The steroidal ethylenediamine RU1968 (1) represents a well-characterized, potent, and fairly selective cross-species inhibitor of CatSper. Due to its two additional centers o...
Preprint
Full-text available
N-methyl-D-aspartate receptors (NMDARs) composed of different splice variants display distinct pH sensitivities and are crucial for learning and memory, as well as for inflammatory or injury processes. Dysregulation of the NMDAR is associated with diseases like Alzheimer’s, Huntington’s, depression and substance addiction. The development of select...
Article
Full-text available
Fluorescent probes that change their spectral properties upon binding to small biomolecules, ions, or changes in the membrane potential (V m) are invaluable tools to study cellular signaling pathways. Here, we introduce a novel technique for simultaneous recording of multiple probes at millisecond time resolution: frequency-and spectrally-tuned mul...
Article
Full-text available
STUDY QUESTION Do selective serotonin reuptake inhibitor (SSRI) antidepressants affect the function of human sperm? SUMMARY ANSWER The SSRI antidepressant Sertraline (e.g. Zoloft) inhibits the sperm-specific Ca2+ channel CatSper and affects human sperm function in vitro. WHAT IS KNOWN ALREADY In human sperm, CatSper translates changes of the chem...
Article
Study question Do Selective Serotonin Reuptake Inhibitor (SSRI) antidepressants affect the function of human sperm? Summary answer The SSRI-antidepressant Sertraline (e.g. Zoloft) inhibits the sperm-specific Ca2+ channel CatSper and affects human sperm function in vitro. What is known already In human sperm, CatSper translates changes of the chem...
Article
Full-text available
The sperm-specific Ca2+ channel CatSper registers chemical cues that assist human sperm to fertilize the egg. Prime examples are progesterone and prostaglandin E1 that activate CatSper without involving classical nuclear and G protein-coupled receptors, respectively. Here, we study the action of seminal and follicular fluid as well of the contained...
Article
Full-text available
Mammalian oocytes are enveloped by the zona pellucida (ZP), an extracellular matrix of glycoproteins. In sperm, stimulation with ZP proteins evokes a rapid Ca2+ influx via the sperm-specific, pH-sensitive Ca2+ channel CatSper. However, the physiological role and molecular mechanisms underlying ZP-dependent activation of CatSper are unknown. Here, w...
Article
Full-text available
The sperm-specific CatSper channel controls the influx of Ca2+ into the flagellum and, thereby, the swimming behavior of sperm. A hallmark of human CatSper is its polymodal activation by membrane voltage, intracellular pH, and oviductal hormones. Whether CatSper is also activated by signaling pathways involving an increase of cAMP and ensuing activ...
Preprint
Full-text available
The sperm-specific CatSper channel controls the influx of Ca ²⁺ into the flagellum and, thereby, the swimming behavior of sperm. A hallmark of human CatSper is its polymodal activation by membrane voltage, intracellular pH, and oviductal hormones. Whether CatSper is also activated by signaling pathways involving an increase of cAMP and ensuing acti...
Article
Full-text available
Navigation of sperm in fluid flow, called rheotaxis, provides long-range guidance in the mammalian oviduct. The rotation of sperm around their longitudinal axis (rolling) promotes rheotaxis. Whether sperm rolling and rheotaxis require calcium (Ca 2+) influx via the sperm-specific Ca 2+ channel CatSper, or rather represent passive biomechanical and...
Article
Full-text available
N-Methyl-D-aspartate (NMDA) receptors (NMDARs) are among the most important excitatory neurotransmitter receptors in the human brain. Autoantibodies to the human NMDAR cause the most frequent form of autoimmune encephalitis involving autoantibody-mediated receptor cross-linking and subsequent internalization of the antibody-receptor complex. This h...
Article
Full-text available
The Cysteine-RIch Secretory Proteins (CRISPs) are a group of proteins which show a pronounced expression biased to the male reproductive tract. While sperm encounter CRISPs at virtually all phases of sperm development and maturation, CRISP2 is the sole CRISP produced during spermatogenesis, wherein it is incorporated into the developing sperm head...
Chapter
Sperm from sea urchins are attracted by chemical cues released by the egg—a mechanism called chemotaxis. We describe here the signaling pathway and molecular components endowing sperm with single-molecule sensitivity. Chemotactic signaling and behavioral responses occur on a timescale of a few milliseconds to seconds. We describe the techniques and...
Article
Study question: Does the chemosensory activation of CatSper Ca2+ channels in human sperm give rise to additive, sub-additive or even synergistic actions among agonists? Summary answer: We show that oviductal ligands and endocrine disrupting chemicals (EDCs) activate human CatSper highly synergistically. What is known already: In human sperm, t...
Article
Background and purpose: Sperm from many species share the sperm-specific Ca2+ channel CatSper (cation channel of sperm) that controls the intracellular Ca2+ concentration and, thereby, the swimming behaviour. A growing body of evidence suggests that the mechanisms controlling CatSper activity and the role of the channel during fertilization differ...
Article
Grant: This work was supported by German Research Foundation Grants CRU326 (to T.S. and F.T.) and SFB1089 (to U.B.K.); Cells-in- Motion Cluster of Excellence (Münster) Grant CiM20027 (to T.S.); and a research fellowship from the European Society for Paediatric Endocrinology (to I.V.W.).
Article
Key points: In human sperm, proton flux across the membrane is controlled by the voltage-gated proton channel Hv1. We show that sperm harbour both Hv1 and an N-terminally cleaved isoform termed Hv1Sper. The pH-control of Hv1Sper and Hv1 is distinctively different. Hv1Sper and Hv1 can form heterodimers that combine features of both constituents. Cl...
Article
Full-text available
Sperm require a sense of direction to locate the egg for fertilization. They follow gradients of chemical and physical cues provided by the egg or the oviduct. However, the principles underlying three-dimensional (3D) navigation in chemical landscapes are unknown. Here using holographic microscopy and optochemical techniques, we track sea urchin sp...
Article
Full-text available
Microbes or danger signals trigger inflammasome sensors, which induce polymerization of the adaptor ASC and the assembly of ASC specks. ASC specks recruit and activate caspase-1, which induces maturation of the cytokine interleukin 1β (IL-1β) and pyroptotic cell death. Here we found that after pyroptosis, ASC specks accumulated in the extracellular...
Article
Full-text available
Microbes or danger signals trigger inflammasome sensors, which induce polymerization of the adaptor ASC and the assembly of ASC specks. ASC specks recruit and activate caspase-1, which induces maturation of the cytokine interleukin 1β (IL-1β) and pyroptotic cell death. Here we found that after pyroptosis, ASC specks accumulated in the extracellular...
Article
Full-text available
Synthetic endocrine disrupting chemicals (EDCs), omnipresent in food, household, and personal care products, have been implicated in adverse trends in human reproduction, including infertility and increasing demand for assisted reproduction. Here, we study the action of 96 ubiquitous EDCs on human sperm. We show that structurally diverse EDCs activ...
Article
Full-text available
Synthetic endocrine disrupting chemicals (EDCs), omnipresent in food, household, and personal care products, have been implicated in adverse trends in human reproduction, including infertility and increasing demand for assisted reproduction. Here, we study the action of 96 ubiquitous EDCs on human sperm. We show that structurally diverse EDCs activ...
Data
Full-text available
Indicators of merit for the mass spectrometric results. DOI: http://dx.doi.org/10.7554/eLife.01438.020
Article
Full-text available
Sperm are equipped with a unique set of ion channels that orchestrate fertilization. In mouse sperm, the principal K+ current (IKSper) is carried by the Slo3 channel, which sets the membrane potential (Vm) in a strongly pHi-dependent manner. Here, we show that IKSper in human sperm is activated weakly by pHi and more strongly by Ca2+. Corresponding...
Article
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Article
Full-text available
The sperm-specific CatSper channel controls the intracellular Ca(2+) concentration ([Ca(2+)](i)) and, thereby, the swimming behaviour of sperm. In humans, CatSper is directly activated by progesterone and prostaglandins-female factors that stimulate Ca(2+) influx. Other factors including neurotransmitters, chemokines, and odorants also affect sperm...
Article
Full-text available
In the oviduct, cumulus cells that surround the oocyte release progesterone. In human sperm, progesterone stimulates a Ca(2+) increase by a non-genomic mechanism. The Ca(2+) signal has been proposed to control chemotaxis, hyperactivation and acrosomal exocytosis of sperm. However, the underlying signalling mechanism has remained mysterious. Here we...

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