Daniela Fietz

Justus-Liebig-Universität Gießen | JLU · Institute of Veterinary Anatomy, Histology and Embryology

At the start of the COVID-pandemic in March 2020, the Institutes of Veterinary Anatomy of the five German educational institutions were confronted with the challenge of digitalising all lectures for the second and fourth semesters of veterinary students. After an online kick-off event and a preliminary status quo meeting, available digital teaching...

Polo-like kinases (PLKs) belong to a five-membered family of highly conserved serine/threonine kinases (PLK1-5) that play differentiated and essential roles as key mitotic kinases and cell cycle regulators and with this in proliferation and cellular growth. Besides, evidence is accumulating for complex and vital non-mitotic functions of PLKs. Dysre...

Mutations affecting the germline can result in infertility or the generation of germ cell tumors (GCT), highlighting the need to identify and characterize the genes controlling germ cell development. The RNA-binding protein and E3 ubiquitin ligase TRIM71 is essential for embryogenesis, and its expression has been reported in GCT and adult mouse tes...

Mutations affecting the germline can result in infertility or the generation of germ cell tumors (GCT), highlighting the need to identify and characterize the genes controlling the complex molecular network orchestrating germ cell development. TRIM71 is a stem cell-specific factor essential for embryogenesis, and its expression has been reported in...

Background: Clomiphene citrate has been proposed as pre-treatment for infertile men with non-obstructive, testicular azoospermia (NOA) before surgery for testicular sperm extraction (TESE), especially when serum testosterone is low. Case presentation: Here, we report on a 33-year old azoospermic patient with a previous history of repeated "fresh...

Detailed morphological characterization of testicular leukocytes in the adult CX3CR1 gfp/+ transgenic mouse identified two distinct CX3CR1 ⁺ mononuclear phagocyte (macrophage and dendritic cell) populations: stellate/dendriform cells opposed to the seminiferous tubules (peritubular), and polygonal cells associated with Leydig cells (interstitial)....

Azoospermia is observed in 10–15% of men suffering couple infertility. While obstructive (OA) needs to be distinguished from non-obstructive azoospermia (NOA), both entities may be due to congenital or genetically determined disorders as well as acquired disease. NOA is predominantly caused by primary testicular damage, whereas endocrine disease du...

Male infertility affects ∼7% of men, but its causes remain poorly understood. The most severe form is non-obstructive azoospermia (NOA), which is, in part, caused by an arrest at meiosis. So far, only a few validated disease-associated genes have been reported. To address this gap, we performed whole-exome sequencing in 58 men with unexplained meio...

Background: The precise movement of proteins and vesicles is an essential ability for all eukaryotic cells. Nowhere is this more evident than during the remarkable transformation that occurs in spermiogenesis-the transformation of haploid round spermatids into sperm. These transformations are critically dependent upon both the microtubule and the...

Male infertility affects ~7% of men in Western societies, but its causes remain poorly understood. The most clinically severe form of male infertility is non-obstructive azoospermia (NOA), which is, in part, caused by an arrest at meiosis, but so far only few genes have been reported to cause germ cell arrest in males. To address this gap, whole ex...

Ciliated bronchial epithelium 1 (CBE1) is a microtubule-associated protein localized to the manchette and developing flagellum during spermiogenesis, and associated with sperm maturation arrest in humans. It was hypothesized that CBE1 functions in microtubule-mediated transport mechanisms and sperm tail formation. To test this hypothesis, we analys...

Eine Azoospermie findet sich bei 10–15 % der Männer, die wegen eines unerfüllten Kinderwunschs untersucht werden. Differenzialdiagnostisch sind die obstruktive (OA) und nichtobstruktive Azoospermie (NOA) zu unterscheiden, wobei jeweils kongenitale bzw. genetisch bedingte sowie erworbene Ursachen zugrunde liegen können. Am häufigsten führen primär d...

Considering infection/inflammation to be an important risk factor in male infertility, the aim of this study was to make a comprehensive evaluation of the prevalence of urogenital tract infection/inflammation and its potential impact on sperm retrieval in azoospermic patients. In this prospective study, 71 patients with azoospermia were subjected t...

Study question: Does activin A contribute to testicular fibrosis under inflammatory conditions? Summary answer: Our results show that activin A and key fibrotic proteins are increased in human testicular biopsies with leukocytic infiltrates and impaired spermatogenesis and in murine experimental autoimmune orchitis (EAO) and that activin A stimu...

Background The transcription factor DMRTB1 plays a pivotal role in coordinating the transition between mitosis and meiosis in murine germ cells. No reliable data are available for human testis. Objectives The present study aims to examine the testicular expression pattern of DMRTB1 in men showing normal and impaired spermatogenesis. Materials and...

The practice of human and veterinary medicine is based on the science of anatomy and dissection courses are still irreplaceable in the teaching of anatomy. Embalming is required to preserve body donors, for which process formaldehyde (FA) is the most frequently used and well characterized biocidal substance. Since January 2016, a new occupational e...

In various tissues, steroid hormones may be sulfated, glucuronidated or otherwise modified. For a long time, these hydrophilic molecules have been considered to be merely inactive metabolites for excretion via bile or urine. Nevertheless, different organs such as the placenta and breast tissue produce large amounts of sulfated steroids. After the d...

Sodium-dependent organic anion transporter (SOAT) represents a membrane transporter specific for sulfated steroid hormones, which are supposed to participate in the regulation of reproductive processes. In man, SOAT shows predominant mRNA expression in the testis and here was localized to primary spermatocytes. SOAT mRNA expression is significantly...

Sulfated steroid hormones, such as dehydroepiandrosterone sulfate or estrone-3-sulfate, have long been regarded as inactive metabolites as they cannot activate classical steroid receptors. Some of them are present in the blood circulation at quite high concentrations, but generally sulfated steroids exhibit low membrane permeation due to their hydr...

The sodium-dependent organic anion transporter SOAT (gene name SLC10A6 in man and Slc10a6 in mice) is a plasma membrane transporter for sulfated steroids, which is highly expressed in germ cells of the testis. SOAT can transport biologically inactive sulfated steroids into specific target cells, where they can be reactivated by the steroid sulfatas...

Objective To define the precise cellular localization of ciliated bronchial epithelium 1 (CBE1) in the human testis and test its relationship to impaired spermatogenesis. Design Gene expression analysis, and histologic and immunohistochemical evaluation. Setting University research laboratories and andrologic outpatient clinic. Patient(s) Forty-...

The human testis is a paired endocrine and exocrine organ producing sex steroid hormones and mature haploid sperm. The latter are transported into the epididymis for further maturation and storage. Especially the endocrine function requires a specific anatomical and histological structure of the testis, i.e., a special “location” of the testis outs...

The human testis is a paired endocrine and exocrine organ producing sex steroid hormones and mature haploid sperm. The latter are transported into the epididymis for further maturation and storage. Especially the endocrine function requires a specific anatomical and histological structure of the testis, i.e., a special “location” of the testis outs...

Within the human testis, large amounts of sulfated steroid hormones are produced. As shown in breast tissue and placenta, these might not only be excretion intermediates, but re-activated in target cells by steroid sulfatase (STS). This process is called sulfatase pathway and may play a pivotal role in para- and/or intracrine regulation by creating...

Protamines are arginine-rich DNA-binding proteins that replace histones in elongating spermatids. This leads to hypercondensation of chromatin and ensures physiological sperm morphology, thereby protecting DNA integrity. In mice and humans, two protamines, protamine-1 (Prm1) and protamine-2 (Prm2) are expressed in a species-specific ratio. In human...

The effects of extracellular calcium on osteogenic differentiation capacity of human bone-derived mesenchymal stromal cells with special regard to connexin 43 (cx43) have been investigated by means of cell culture experiments. Mesenchymal stromal cells isolated from human cancellous bone were cultured on tissue culture plates at different calcium i...

Objective: To define the stage-by-stage expression of KATNB1 during human spermatogenesis. Design: Gene expression analysis, histologic and immunohistochemical evaluation. Setting: University research laboratories and andrological clinic. Patient(s): Eighty human testicular biopsy samples: 43 showing normal spermatogenesis, 9 with maturation...

Study Question Which immune cells and cytokine profiles are characteristic for testicular germ cell neoplasia and what consequences does this have for the understanding of the related testicular immunopathology? Summary Answer The unique immune environment of testicular germ cell neoplasia comprises B cells and dendritic cells as well as high tran...

Sulfated steroid hormones, such as dehydroepiandrosterone sulfate or estrone-3-sulfate, have long been regarded as inactive metabolites as they cannot activate classical steroid receptors. Some of them are present in the blood circulation at quite high concentrations, but generally sulfated steroids exhibit low membrane permeation due to their hydr...

In situ hybridization (ISH) is an excellent method for detecting RNA in histological sections, both to detect gene expression and to assign gene expression to a distinct cell population. Therefore, ISH may be used in basic cell biology to detect the expression of certain genes within a tissue containing various cell populations. Here, we describe t...

Androgens play an important role for the development of male fertility and gained interest as growth and survival factors for certain types of cancer. Androgens act via the androgen receptor (AR/Ar), which is involved in various cell biological processes such as sex differentiation. To study the functional mechanisms of androgen action, cell cultur...

The Sertoli cell (SC)-specific knockout (KO) of connexin43 (Cx43) results in spermatogenic arrest at the level of spermatogonia and/or SC-only syndrome. Histology of the interstitial compartment suggests Leydig cell (LC) hyperplasia. Our aim has been to investigate possible effects of the SC-specific KO of Cx43 (SCCx43KO) on interstitial LC. We the...

Estrogen signaling is considered to play an important role in spermatogenesis, spermiogenesis and male fertility. Estrogens can act via the two nuclear estrogen receptors ESR1 (ERα) and ESR2 (ERβ) or via the intracellular G-protein-coupled estrogen receptor 1 (GPER, formerly GPR30). Several reports on the localization and expression of all three re...

Sulfated steroid hormones are commonly considered to be biologically inactive metabolites, but may be reactivated by the steroid sulfatase into biologically active free steroids, thereby having regulatory function via nuclear androgen and estrogen receptors which are widespread in the testis. However, a prerequisite for this mode of action would be...

Immunofluorescence and immunohistochemistry of consecutive sections of the human testis detecting SOAT and Golgi marker protein Golgin A2. IHC and IF analyses were performed with the Soat329–344 (A, C) and Golgin A2 (B, D) antibodies in consecutive sections of the human testis. IHC was performed using AEC staining and hematoxylin counterstain. For...

Overview on SOAT expression in different germ cell stages in the human testis. IHC was performed using the Soat329–344 antibody with subsequent AEC staining and hematoxylin counterstain. For negative control, primary antibody was incubated with a 100-fold molar excess of immunizing peptide (pre-incubation control, inset). Primary magnification ×20....

The sodium-dependent organic anion transporter SOAT is a member of the Solute Carrier Family SLC10. In man, this carrier is predominantly expressed in the testis and has transport activity for sulfoconjugated steroid hormones. Here, we report on cloning, expression analysis and functional characterization of the mouse Soat (mSoat) and compare its c...

Mesenchymal stem cells have become extremely interesting for regenerative medicine and tissue engineering in the horse. Stem cell therapy has been proven to be a powerful and successful instrument, in particular for the healing of tendon lesions. We pre-differentiated equine adipose-tissue-derived stem cells (ASCs) in a collagen I gel scaffold by a...

Connexin 43 (Cx 43)-expressed by germ cells (GC), Sertoli cells (SC) and Leydig cells-is one of at least eleven Cx in the murine testis. A general knockout (KO) of Cx 43 in mice results in perinatal death and a SC-specific KO of Cx 43 (SCCx43KO) causes infertility of male mice by preventing the initiation of spermatogenesis. To further elucidate th...

Surgically removed testicular tissue in cryptorchid stallions is sometimes difficult to identify because of morphological and histological malformation. Therefore, a sure method to characterise the removed tissue is required. A 2-year-old Haflinger stallion was castrated after diagnosis of cryptorchidism to remove the left intra-abdomnial testis. I...

Laser-assisted cell picking of testis biopsy showing normal spermatogenesis before (A) and after (B) catapulting of marked interstitial tissue and tubules Note: a = tubule showing normal spermatogenesis b = interstitial tissue, consisting predominantely of Leydig cells

The androgen receptor (AR) is a ligand-activated transcriptional factor with crucial importance for spermatogenesis. Its transactivation domain consists of a polymorphic sequence of 9-36 cytosin-adenin-guanin (CAG) repeats. Within the physiological range an increased CAG repeat length is assumed to correlate with the reduced androgen sensitivity re...

The human DEAD-box Y (DBY) RNA helicase (aka DDX3Y) gene is thought to be the major azoospermia factor a (AZFa) gene in proximal Yq11. Although it is transcribed in many tissues, the protein is expressed only in spermatogonia. In this study, we demonstrate that this translational control mechanism is probably germ cell-specific because of its assoc...

To study a novel sequence variation within the androgen receptors' N-terminal CAG repeat region and possible resulting consequences for the receptors' three-dimensional (3D) protein structure. Controlled clinical study. University research and andrology clinic. Twenty-one adult infertile men. Ultraviolet laser-assisted microdissection (PALM, Microl...