scholarly journals Mast Cells in the Auditory Periphery of Rodents

2020 ◽  
Vol 10 (10) ◽  
pp. 697
Author(s):  
Agnieszka J. Szczepek ◽  
Tatyana Dudnik ◽  
Betül Karayay ◽  
Valentina Sergeeva ◽  
Heidi Olze ◽  
...  
Keyword(s):  
Mast Cells ◽  
Postnatal Development ◽  
Wistar Rats ◽  
Current Knowledge ◽  
Stria Vascularis ◽  
Basic Knowledge ◽  
Spiral Ligament ◽  
Auditory Periphery ◽  
Postnatal Maturation ◽  
Functional Studies

Mast cells (MCs) are densely granulated cells of myeloid origin and are a part of immune and neuroimmune systems. MCs have been detected in the endolymphatic sac of the inner ear and are suggested to regulate allergic hydrops. However, their existence in the cochlea has never been documented. In this work, we show that MCs are present in the cochleae of C57BL/6 mice and Wistar rats, where they localize in the modiolus, spiral ligament, and stria vascularis. The identity of MCs was confirmed in cochlear cryosections and flat preparations using avidin and antibodies against c-Kit/CD117, chymase, tryptase, and FcεRIα. The number of MCs decreased significantly during postnatal development, resulting in only a few MCs present in the flat preparation of the cochlea of a rat. In addition, exposure to 40 µM cisplatin for 24 h led to a significant reduction in cochlear MCs. The presence of MCs in the cochlea may shed new light on postnatal maturation of the auditory periphery and possible involvement in the ototoxicity of cisplatin. Presented data extend the current knowledge about the physiology and pathology of the auditory periphery. Future functional studies should expand and translate this new basic knowledge to clinics.

scholarly journals Experimental estrogen-induced hyperprolactinemia results in bone-related hearing loss in the guinea pig

2007 ◽  
Vol 293 (5) ◽  
pp. E1224-E1232 ◽  
Author(s):  
Kathleen C. Horner ◽  
Yves Cazals ◽  
Régis Guieu ◽  
Marc Lenoir ◽  
Nicole Sauze
Keyword(s):  
Hearing Loss ◽  
Hair Cell ◽  
Inner Ear ◽  
Stria Vascularis ◽  
Compound Action Potential ◽  
Spiral Ligament ◽  
Functional Studies ◽  
Fischer 344 ◽  
Inner Ear Dysfunction ◽  
Cryostat Sections

Our group (Horner KC, Guieu R, Magnan J, Chays A, Cazals Y. Neuropsychopharmacology 26: 135–138, 2002) has earlier described hyperprolactinemia in some patients presenting inner ear dysfunction. However, in that study, it was not possible to determine whether hyperprolactinemia was a cause or an effect of the symptoms. To investigate the effect of hyperprolactinemia on inner ear function, we first developed a model of hyperprolactinemia in estrogen-primed Fischer 344 rats and then performed functional studies on pigmented guinea pigs. Hyperprolactinemia induced, after 2 mo, a hearing loss of ∼30–40 dB across all frequencies, as indicated by the compound action potential audiogram. During the 3rd mo, the hearing loss continued to deteriorate. The threshold shifts were more substantial in males than in females. Observations under a dissection microscope revealed bone dysmorphology of the bulla and the cochlea. Light microscopy observations of cryostat sections confirmed bone-related pathology of the bony cochlear bulla and the cochlear wall and revealed morphopathology of the stria vascularis and spiral ligament. Scanning electron microscopy revealed loss of hair cells and stereocilia damage, in particular in the upper three cochlear turns and the two outermost hair cell rows. The data provide the first evidence of otic capsule and hair cell pathology associated with estrogen-induced prolonged hyperprolactinemia and suggest that conditions such as pregnancy, anti-psychotic drug treatment, aging, and/or stress might lead to similar ear dysfunctions.

scholarly journals Distinct Expression Patterns Predict Differential Roles of the miRNA-Binding Proteins, Lin28 and Lin28b, in the Mouse Testis: Studies During Postnatal Development and in a Model of Hypogonadotropic Hypogonadism

Endocrinology ◽  
2013 ◽  
Vol 154 (3) ◽  
pp. 1321-1336 ◽  
Author(s):  
Francisco Gaytan ◽  
Susana Sangiao-Alvarellos ◽  
María Manfredi-Lozano ◽  
David García-Galiano ◽  
Francisco Ruiz-Pino ◽  
...  
Keyword(s):  
Postnatal Development ◽  
Binding Proteins ◽  
Rna Binding ◽  
Hypogonadotropic Hypogonadism ◽  
Expression Patterns ◽  
Mouse Testis ◽  
Null Mouse ◽  
Cellular Distribution ◽  
Protein Distribution ◽  
Postnatal Maturation

Abstract Lin28 (also termed Lin28a) and Lin28b are related RNA-binding proteins, involved in the control of microRNA synthesis, especially of the let-7 family, with putative functions in early (embryo) development. However, their roles during postnatal maturation remain ill defined. Despite the general assumption that Lin28 and Lin28b share similar targets and functions, conclusive demonstration of such redundancy is still missing. In addition, recent observations suggest a role of Lin28 proteins in mammalian reproduction, which is yet to be defined. We document herein the patterns of RNA expression and protein distribution of Lin28 and Lin28b in mouse testis during postnatal development and in a model of hypogonadotropic hypogonadism as a result of inactivation of the kisspeptin receptor, Gpr54. Lin28 and Lin28b mRNAs were expressed in mouse testis across postnatal maturation, but their levels disparately varied between neonatal and pubertal periods, with peak Lin28 levels in infantile testes and sustained elevation of Lin28b mRNA in young adult male gonads, where relative levels of let-7a and let-7b miRNAs were significantly suppressed. In addition, Lin28 peptides displayed totally different patterns of cellular distribution in mouse testis: Lin28 was located in undifferentiated and type-A1 spermatogonia, whereas Lin28b was confined to spermatids and interstitial Leydig cells. These profiles were perturbed in Gpr54 null mouse testis, which showed preserved but irregular Lin28 signal and absence of Lin28b peptide, which was rescued by administration of gonadotropins, mainly hCG (as super-agonist of LH). In addition, increased relative levels of Lin28, but not Lin28b, mRNA and of let-7a/let-7b miRNAs were observed in Gpr54 KO mouse testes. Altogether, our data are the first to document the divergent patterns of cellular distribution and mRNA expression of Lin28 and Lin28b in the mouse testis along postnatal maturation and their alteration in a model of congenital hypogonadotropic hypogonadism. Our findings suggest distinct functional roles of these two related, but not overlapping, miRNA-binding proteins in the male gonad.

scholarly journals Postnatal maturation of the dog stria vascularis? an immunohistochemical study

2002 ◽  
Vol 270A (1) ◽  
pp. 82-92 ◽  
Author(s):  
Ang�lique G. Coppens ◽  
Isabelle Salmon ◽  
Claus W. Heizmann ◽  
Robert Kiss ◽  
Luc Poncelet
Keyword(s):  
Immunohistochemical Study ◽  
Stria Vascularis ◽  
Postnatal Maturation

scholarly journals The Mast Cell-Aryl Hydrocarbon Receptor Interplay at the Host-Microbe Interface

2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Claudio Costantini ◽  
Giorgia Renga ◽  
Vasilis Oikonomou ◽  
Giuseppe Paolicelli ◽  
Monica Borghi ◽  
...  
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Aryl Hydrocarbon Receptor ◽  
Current Knowledge ◽  
Cell Physiology ◽  
Effector Functions ◽  
Host Protection ◽  
Aryl Hydrocarbon ◽  
Environmental Agents ◽  
Sense And Respond

Mast cells are increasingly being recognized as crucial cells in the response of the organism to environmental agents. Interestingly, the ability of mast cells to sense and respond to external cues is modulated by the microenvironment that surrounds mast cells and influences their differentiation. The scenario that is emerging unveils a delicate equilibrium that balances the effector functions of mast cells to guarantee host protection without compromising tissue homeostasis. Among the environmental components able to mold mast cells and fine-tune their effector functions, the microorganisms that colonize the human body, collectively known as microbiome, certainly play a key role. Indeed, microorganisms can regulate not only the survival, recruitment, and maturation of mast cells but also their activity by setting the threshold required for the exploitation of their different effector functions. Herein, we summarize the current knowledge about the mechanisms underlying the ability of the microorganisms to regulate mast cell physiology and discuss potential deviations that result in pathological consequences. We will discuss the pivotal role of the aryl hydrocarbon receptor in sensing the environment and shaping mast cell adaptation at the host-microbe interface.

scholarly journals Do Mast Cells Contribute to the Antifungal Host Defense?

Cells ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2510
Author(s):  
Paulina Żelechowska ◽  
Joanna Pastwińska ◽  
Ewa Brzezińska-Błaszczyk ◽  
Justyna Agier
Keyword(s):  
Mast Cells ◽  
Host Defense ◽  
Immune Cells ◽  
Defense Mechanisms ◽  
Fungal Infections ◽  
Current Knowledge ◽  
Extracellular Dna ◽  
Opportunistic Pathogens ◽  
Strategic Location ◽  
Fungal Kingdom

The fungal kingdom includes a group of microorganisms that are widely distributed in the environment, and therefore the exposure to them is almost constant. Furthermore, fungal components of the microbiome, i.e., mycobiome, could serve as a reservoir of potentially opportunistic pathogens. Despite close encounters with fungi, defense mechanisms that develop during fungal infections remain unexplored. The strategic location of mast cells (MCs) close to the external environment places them among the first cells to encounter pathogens along with the other innate immune cells. MCs are directly involved in the host defense through the ability to destroy pathogens or indirectly by activating other immune cells. Most available data present MCs’ involvement in antibacterial, antiviral, or antiparasitic defense mechanisms. However, less is known about their contribution in defense mechanisms against fungi. MCs may support immune responses to fungi or their specific molecules through initiated degranulation, synthesis and release of cytokines, chemokines, mediators, and generation of reactive oxygen species (ROS), as well as immune cells’ recruitment, phagocytosis, or provision of extracellular DNA traps. This review summarizes current knowledge on host defense mechanisms against fungi and MCs’ involvement in those processes. It also describes the effects of fungi or fungus-derived constituents on MCs’ activity.

scholarly journals An Investigation Into How Far Do Residents Adopt Measures to Reduce Microbial Hazards During Food Handling

2017 ◽  
Vol 5 (1) ◽  
pp. 06-14
Author(s):  
Rajesh Jeewon ◽  
Seerauj Nouvishika ◽  
Dauharry Kumar ◽  
Ahinsa Jheelan-Ramchandur
Keyword(s):  
Food Safety ◽  
Current Knowledge ◽  
Critical Role ◽  
Basic Knowledge ◽  
Personal Hygiene ◽  
Food Hygiene ◽  
Food Handling ◽  
Handling Practices ◽  
Food Handling Practices ◽  
The Impact

Foodborne diseases have always been linked to numerous food manufacturing elements and home practices of purchasers and the latter does play a critical role in disease prevention. Consumers have the ultimate responsibility for handling and storing food safely and take adequate safety precautions when preparing and consuming food at home to avoid health related problems associated with microbial hazards. The objectives of this survey were to evaluate current knowledge of consumers pertaining to food hygiene and food safety concepts as well as to assess food handling practices that residents adopt to reduce microbial hazards in the domestic environment. A sample of 300 Mauritian residents were selected to participate in a questionnaire based survey. Questions in the questionnaire were based on hygienic practices with respect to food handling, food safety and personal hygiene. SPSS (Statistical Package for Social Sciences) was used to analyze the results and Microsoft excel was used to generate pie charts, and bar charts. The results obtained demonstrated that the level of knowledge pertaining to food safety and food hygiene and how to reduce microbial hazards were above average. Majority of the residents were knowledgeable about major aspects related to proper food handling behaviors but need more education pertaining to the use of thermometers to check for food temperature. The nature of the risk, personal and environmental factors (psychological, demographic and socio-economic factors, cultural and economic) were found to be the factors affecting food safety behaviors among consumers. Consumers can become more motivated to improve their behaviors if they are made aware of the impact of risky practices. Although, most consumers had basic knowledge pertaining to food safety, food hygiene and food handling practices, it is important to continually inform consumers about safe food handling practices through various channels.

Ultrastructural Characteristics of Capillaries Entering and Leaving the Stria Vascularis

1986 ◽  
Vol 95 (3) ◽  
pp. 309-312 ◽  
Author(s):  
Kensuke Watanabe
Keyword(s):  
Horseradish Peroxidase ◽  
Basal Cell ◽  
Stria Vascularis ◽  
The Other ◽  
Spiral Ligament ◽  
Perivascular Spaces ◽  
Basal Cells ◽  
Vascular Flow ◽  
Cell Layers ◽  
Ultrastructural Characteristics

Capillaries entering and leaving the stria vascularis were surrounded by layers of basal cells and fibrocytes. The entering capillaries were surrounded by one or two thin basal cells, while the leaving capillaries were surrounded by four or five thicker and interdigitated basal cell layers. Moreover, the layers surrounding the leaving capillaries persisted further into the spiral ligament. Two kinds of filaments were observed in the basal cells, one thin and the other thick. Capillaries were observed to leak horseradish peroxidase before they entered and after they left the stria vascularis. Although the reaction product of horseradish peroxidase was observed in all perivascular spaces of leaving capillaries, very little or no reaction product was observed around some entering capillaries. It is speculated that the layers of basal cells and fibrocytes around entering and leaving capillaries control the vascular flow out of the stria vascularis, although the layers around leaving capillaries may be more contractile than those around entering capillaries.

NUCLEOLI IN DEVELOPING HISTAMINERGIC NEURONS OF THE RAT BRAIN

2020 ◽  
pp. 7-13
Author(s):  
Сергей Михайлович Зиматкин ◽  
Анастасия Викторовна Заерко ◽  
Екатерина Михайловна Федина
Keyword(s):  
Rat Brain ◽  
Postnatal Development ◽  
Size Structure ◽  
Postnatal Ontogenesis ◽  
Hypothalamic Nucleus ◽  
Postnatal Ontogeny ◽  
Hypothalamic Region ◽  
Postnatal Maturation ◽  
Histaminergic Neurons ◽  
White Rats

Введение. Существуют ряд физиологических, экспериментальных и патологических условий, которые могут индуцировать изменения в размере, морфологии, местоположении и количестве ядрышек в соответствии с функциональной и метаболической активностью. Одним из таких условий является постнатальное развитие клеток, в том числе и нейронов. Цель - изучение особенностей структурно-функционального становления ядрышек гистаминергических нейронов мозга крысы в постнатальном онтогенезе. Материал и методы. Работа выполнена на беспородных белых крысах (12 особей) в возрасте 5, 20 и 45 сут постнатального онтогенеза. Изучали число и размеры ядрышек в ядрах гистаминергических нейронов в ядре E2 задней гипоталамической области мозга крыс с применением электронно-микроскопических и морфометрических методик, а также - непараметрической статистики. Результаты. У крыс от 5 до 45 сут постнатального развития уменьшается число и увеличиваются размеры ядрышек в ядре гистаминергических нейронов задней области гипоталамуса, а также происходит перемещение ядрышек от кариолеммы к центру ядра. По мере взросления животных в гистаминергических нейронах происходит постепенное преобразование относительно компактных ядрышек в ретикулярные, при этом увеличивается количество фибриллярного и гранулярного компонентов, а также возрастает число и уменьшаются размеры фибриллярных центров. Кроме того, наблюдается уменьшение облака мигрирующих субъединиц рибосом между ядрышком и кариолеммой, а также количества ассоциированного с ядрышком гетерохроматина. Выводы. В ядре E2 гипоталамуса крыс в возрасте от 5 до 45 сут постнатального онтогенеза значительно изменяются число, размеры, строение и топография ядрышек в ядрах гистаминергических нейронов. Introduction. There are a number of physiological, experimental, and pathological conditions that can induce changes in the size, morphology, location, and number of nucleoli in accordance with functional and metabolic activity. One of these conditions is the postnatal maturation of cells, including neurons. Objective - to assess the characteristics of structural and functional formation of histaminergic neurons nucleoli in rat brain during postnatal ontogeny. Material and methods. The work was performed on the offspring of outbred white rats (12 rats) on the 5th, 20th and 45th days of postnatal ontogenesis. Electron microscopic, morphometric and statistical methods were used to study the number and quantity of nucleoli in the nuclei of histaminergic neurons located in the E2 nucleus of posterior hypothalamic region of rat brain. Results. From the 5th to the 45th day of the rat postnatal development, there was a decrease in the number and increase in the size of the nucleoli in the nuclei of histaminergic neurons located in the posterior hypothalamic region, as well as their movement from the karyolemma to the center of the nucleus. As animals growed up, relatively compact nucleoli in the brain histaminergic neurons gradually transformed into reticular nucleoli, while the quantity of fibrillar and granular components increased, at the same time the quantity of fibrillar centers increased and the size of fibrillar centers decreased. In addition, we detected a decrease in the cloud of migrating ribosome subunits between the nucleolus and karyolemma and in the amount of heterochromatin associated with the nucleolus. Conclusions. From the 5th to the 45th day of the postnatal development, the number, size, structure and topography of the nucleoli of the rat brain histaminergic neurons located in the E2 hypothalamic nucleus in postnatal ontogenesis changed significantly.

scholarly journals The Role Played by Mitochondria in FcεRI-Dependent Mast Cell Activation

2020 ◽  
Vol 11 ◽  
Author(s):  
Maria A. Chelombitko ◽  
Boris V. Chernyak ◽  
Artem V. Fedorov ◽  
Roman A. Zinovkin ◽  
Ehud Razin ◽  
...  
Keyword(s):  
Mast Cell ◽  
Transcription Factors ◽  
Mast Cells ◽  
Cell Activation ◽  
Immunoglobulin E ◽  
Mitochondrial Dynamics ◽  
Allergic Diseases ◽  
Mast Cell Activation ◽  
Basic Knowledge ◽  
Mitochondrial Activity

Mast cells play a key role in the regulation of innate and adaptive immunity and are involved in pathogenesis of many inflammatory and allergic diseases. The most studied mechanism of mast cell activation is mediated by the interaction of antigens with immunoglobulin E (IgE) and a subsequent binding with the high-affinity receptor Fc epsilon RI (FcεRI). Increasing evidences indicated that mitochondria are actively involved in the FcεRI-dependent activation of this type of cells. Here, we discuss changes in energy metabolism and mitochondrial dynamics during IgE-antigen stimulation of mast cells. We reviewed the recent data with regards to the role played by mitochondrial membrane potential, mitochondrial calcium ions (Ca2+) influx and reactive oxygen species (ROS) in mast cell FcεRI-dependent activation. Additionally, in the present review we have discussed the crucial role played by the pyruvate dehydrogenase (PDH) complex, transcription factors signal transducer and activator of transcription 3 (STAT3) and microphthalmia-associated transcription factor (MITF) in the development and function of mast cells. These two transcription factors besides their nuclear localization were also found to translocate in to the mitochondria and functions as direct modulators of mitochondrial activity. Studying the role played by mast cell mitochondria following their activation is essential for expanding our basic knowledge about mast cell physiological functions and would help to design mitochondria-targeted anti-allergic and anti-inflammatory drugs.

Sign in / Sign up

Export Citation Format

Share Document