scholarly journals The digestive tract as an essential organ for water acquisition in marine teleosts: lessons from euryhaline eels

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yoshio Takei
Keyword(s):  
Water Absorption ◽  
Digestive Tract ◽  
Molecular Mechanisms ◽  
Research Field ◽  
Animal Physiology ◽  
Ion Absorption ◽  
Monovalent Ions ◽  
Seawater Environment ◽  
And Function

AbstractAdaptation to a hypertonic marine environment is one of the major topics in animal physiology research. Marine teleosts lose water osmotically from the gills and compensate for this loss by drinking surrounding seawater and absorbing water from the intestine. This situation is in contrast to that in mammals, which experience a net osmotic loss of water after drinking seawater. Water absorption in fishes is made possible by (1) removal of monovalent ions (desalinization) by the esophagus, (2) removal of divalent ions as carbonate (Mg/CaCO3) precipitates promoted by HCO3− secretion, and (3) facilitation of NaCl and water absorption from diluted seawater by the intestine using a suite of unique transporters. As a result, 70–85% of ingested seawater is absorbed during its passage through the digestive tract. Thus, the digestive tract is an essential organ for marine teleost survival in the hypertonic seawater environment. The eel is a species that has been frequently used for osmoregulation research in laboratories worldwide. The eel possesses many advantages as an experimental animal for osmoregulation studies, one of which is its outstanding euryhalinity, which enables researchers to examine changes in the structure and function of the digestive tract after direct transfer from freshwater to seawater. In recent years, the molecular mechanisms of ion and water transport across epithelial cells (the transcellular route) and through tight junctions (the paracellular route) have been elucidated for the esophagus and intestine. Thanks to the rapid progress in analytical methods for genome databases on teleosts, including the eel, the molecular identities of transporters, channels, pumps and junctional proteins have been clarified at the isoform level. As 10 y have passed since the previous reviews on this subject, it seems relevant and timely to summarize recent progress in research on the molecular mechanisms of water and ion transport in the digestive tract in eels and to compare the mechanisms with those of other teleosts and mammals from comparative and evolutionary viewpoints. We also propose future directions for this research field to achieve integrative understanding of the role of the digestive tract in adaptation to seawater with regard to pathways/mechanisms including the paracellular route, divalent ion absorption, metabolon formation and cellular trafficking of transporters. Notably, some of these have already attracted practical attention in laboratories.

scholarly journals Mechanosensitive Ion Channel Piezo1 Regulates Myocyte Fusion during Skeletal Myogenesis

2020 ◽  
Author(s):  
Huascar Pedro Ortuste Quiroga ◽  
Shingo Yokoyama ◽  
Massimo Ganassi ◽  
Kodai Nakamura ◽  
Tomohiro Yamashita ◽  
...  
Keyword(s):  
Ion Channel ◽  
Molecular Mechanisms ◽  
Myoblast Fusion ◽  
Mechanical Stimuli ◽  
Muscle Satellite Cell ◽  
Myotube Formation ◽  
Mechanosensitive Ion Channel ◽  
And Function ◽  
Sirna Knockdown

AbstractMechanical stimuli such as stretch and resistance training are essential to regulate growth and function of skeletal muscle. However, the molecular mechanisms involved in sensing mechanical stress remain unclear. Here, the purpose of this study was to investigate the role of the mechanosensitive ion channel Piezo1 during myogenic progression. Muscle satellite cell-derived myoblasts and myotubes were modified with stretch, siRNA knockdown and agonist-induced activation of Piezo1. Direct manipulation of Piezo1 modulates terminal myogenic progression. Piezo1 knockdown suppressed myoblast fusion during myotube formation and maturation. This was accompanied by downregulation of the fusogenic protein Myomaker. Piezo1 knockdown also lowered Ca2+ influx in response to stretch. Conversely Piezo1 activation stimulated fusion and increased Ca2+ influx in response to stretch. These evidences indicate that Piezo1 is essential for myotube formation and maturation, which may have implications for msucular dystrophy prevention through its role as a mechanosensitive Ca2+ channel.

scholarly journals The role of Asprosin in patients with dilated cardiomyopathy

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Ming-Shien Wen ◽  
Chao-Yung Wang ◽  
Jih-Kai Yeh ◽  
Chun-Chi Chen ◽  
Ming-Lung Tsai ◽  
...  
Keyword(s):  
Dilated Cardiomyopathy ◽  
Mitochondrial Respiration ◽  
Cardiovascular Events ◽  
Molecular Mechanisms ◽  
Major Adverse Cardiovascular Events ◽  
Study Cohort ◽  
Protective Mechanisms ◽  
Mitochondrial Functions ◽  
And Function

Abstract Background Asprosin is a novel fasting glucogenic adipokine discovered in 2016. Asprosin induces rapid glucose releases from the liver. However, its molecular mechanisms and function are still unclear. Adaptation of energy substrates from fatty acid to glucose is recently considered a novel therapeutic target in heart failure treatment. We hypothesized that the asprosin is able to modulate cardiac mitochondrial functions and has important prognostic implications in dilated cardiomyopathy (DCM) patients. Methods We prospectively enrolled 50 patients (86% male, mean age 55 ± 13 years) with DCM and followed their 5-year major adverse cardiovascular events from 2012 to 2017. Comparing with healthy individuals, DCM patients had higher asprosin levels (191.2 versus 79.7 ng/mL, P < 0.01). Results During the 5-year follow-up in the study cohort, 16 (32.0%) patients experienced adverse cardiovascular events. Patients with lower asprosin levels (< 210 ng/mL) were associated with increased risks of adverse clinical outcomes with a hazard ratio of 7.94 (95% CI 1.88–33.50, P = 0.005) when compared patients with higher asprosin levels (≥ 210 ng/mL). Using cardiomyoblasts as a cellular model, we showed that asprosin prevented hypoxia-induced cell death and enhanced mitochondrial respiration and proton leak under hypoxia. Conclusions In patients with DCM, elevated plasma asprosin levels are associated with less adverse cardiovascular events in five years. The underlying protective mechanisms of asprosin may be linked to its functions relating to enhanced mitochondrial respiration under hypoxia.

New functions for old factors: the role of polyamines during the establishment of pregnancy

2019 ◽  
Vol 31 (7) ◽  
pp. 1228
Author(s):  
Jane C. Fenelon ◽  
Bruce D. Murphy
Keyword(s):  
Molecular Mechanisms ◽  
New Technologies ◽  
Alternative Pathway ◽  
Rapid Expansion ◽  
Polyamine Synthesis ◽  
Recent Developments ◽  
And Function ◽  
Implantation Period ◽  
Synthesis Regulation

Implantation is essential for the establishment of a successful pregnancy, and the preimplantation period plays a significant role in ensuring implantation occurs in a timely and coordinated manner. This requires effective maternal–embryonic signalling, established during the preimplantation period, to synchronise development. Although multiple factors have been identified as present during this time, the exact molecular mechanisms involved are unknown. Polyamines are small cationic molecules that are ubiquitously expressed from prokaryotes to eukaryotes. Despite being first identified over 300 years ago, their essential roles in cell proliferation and growth, including cancer, have only been recently recognised, with new technologies and interest resulting in rapid expansion of the polyamine field. This review provides a summary of our current understanding of polyamine synthesis, regulation and function with a focus on recent developments demonstrating the requirements for polyamines during the establishment of pregnancy up to the implantation stage, in particular the role of polyamines in the control of embryonic diapause and the identification of an alternative pathway for their synthesis in sheep pregnancy. This, along with other novel discoveries, provides new insights into the control of the peri-implantation period in mammals and highlights the complexities that exist in regulating this critical period of pregnancy.

The role of mitochondria in axonal degeneration and tissue repair in MS

2012 ◽  
Vol 18 (8) ◽  
pp. 1058-1067 ◽  
Author(s):  
J van Horssen ◽  
ME Witte ◽  
O Ciccarelli
Keyword(s):  
Mitochondrial Dysfunction ◽  
Tissue Repair ◽  
Molecular Mechanisms ◽  
Axonal Degeneration ◽  
Axonal Damage ◽  
Mitochondrial Metabolism ◽  
Imaging Studies ◽  
And Function

Axonal injury is a key feature of multiple sclerosis (MS) pathology and is currently seen as the main correlate for permanent clinical disability. Although little is known about the pathogenetic mechanisms that drive axonal damage and loss, there is accumulating evidence highlighting the central role of mitochondrial dysfunction in axonal degeneration and associated neurodegeneration. The aim of this topical review is to provide a concise overview on the involvement of mitochondrial dysfunction in axonal damage and destruction in MS. Hereto, we will discuss putative pathological mechanisms leading to mitochondrial dysfunction and recent imaging studies performed in vivo in patients with MS. Moreover, we will focus on molecular mechanisms and novel imaging studies that address the role of mitochondrial metabolism in tissue repair. Finally, we will briefly review therapeutic strategies aimed at improving mitochondrial metabolism and function under neuroinflammatory conditions.

scholarly journals Recent progress in research on molecular mechanisms of autophagy in the heart

2015 ◽  
Vol 308 (4) ◽  
pp. H259-H268 ◽  
Author(s):  
Yasuhiro Maejima ◽  
Yun Chen ◽  
Mitsuaki Isobe ◽  
Åsa B. Gustafsson ◽  
Richard N. Kitsis ◽  
...  
Keyword(s):  
Heart Disease ◽  
Molecular Mechanisms ◽  
Therapeutic Potential ◽  
Degradation Process ◽  
Structure And Function ◽  
Cellular Functions ◽  
Evolutionarily Conserved ◽  
And Function ◽  
Cellular Dysfunction

Dysregulation of autophagy, an evolutionarily conserved process for degradation of long-lived proteins and organelles, has been implicated in the pathogenesis of human disease. Recent research has uncovered pathways that control autophagy in the heart and molecular mechanisms by which alterations in this process affect cardiac structure and function. Although initially thought to be a nonselective degradation process, autophagy, as it has become increasingly clear, can exhibit specificity in the degradation of molecules and organelles, such as mitochondria. Furthermore, it has been shown that autophagy is involved in a wide variety of previously unrecognized cellular functions, such as cell death and metabolism. A growing body of evidence suggests that deviation from appropriate levels of autophagy causes cellular dysfunction and death, which in turn leads to heart disease. Here, we review recent advances in understanding the role of autophagy in heart disease, highlight unsolved issues, and discuss the therapeutic potential of modulating autophagy in heart disease.

Homeostatic control of biological membranes by dedicated lipid and membrane packing sensors

2015 ◽  
Vol 396 (9-10) ◽  
pp. 1043-1058 ◽  
Author(s):  
Kristina Puth ◽  
Harald F. Hofbauer ◽  
James P. Sáenz ◽  
Robert Ernst
Keyword(s):  
Molecular Mechanisms ◽  
Biological Membranes ◽  
Homeostatic Control ◽  
Open Questions ◽  
Lipid Species ◽  
Sensor Proteins ◽  
And Function ◽  
Lipid Sensors ◽  
Role And Function

Abstract Biological membranes are dynamic and complex assemblies of lipids and proteins. Eukaryotic lipidomes encompass hundreds of distinct lipid species and we have only begun to understand their role and function. This review focuses on recent advances in the field of lipid sensors and discusses methodical approaches to identify and characterize putative sensor domains. We elaborate on the role of integral and conditionally membrane-associated sensor proteins, their molecular mechanisms, and identify open questions in the emerging field of membrane homeostasis.

scholarly journals To form and function: on the role of basement membrane mechanics in tissue development, homeostasis and disease

Open Biology ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 200360
Author(s):  
Nargess Khalilgharibi ◽  
Yanlan Mao
Keyword(s):  
Basement Membrane ◽  
Molecular Mechanisms ◽  
Disease Diagnosis ◽  
Membrane Mechanics ◽  
Form And Function ◽  
And Function ◽  
Tissue Form

The basement membrane (BM) is a special type of extracellular matrix that lines the basal side of epithelial and endothelial tissues. Functionally, the BM is important for providing physical and biochemical cues to the overlying cells, sculpting the tissue into its correct size and shape. In this review, we focus on recent studies that have unveiled the complex mechanical properties of the BM. We discuss how these properties can change during development, homeostasis and disease via different molecular mechanisms, and the subsequent impact on tissue form and function in a variety of organisms. We also explore how better characterization of BM mechanics can contribute to disease diagnosis and treatment, as well as development of better in silico and in vitro models that not only impact the fields of tissue engineering and regenerative medicine, but can also reduce the use of animals in research.

scholarly journals SFPQ Rescues F508del-CFTR Expression and Function in Cystic Fibrosis Bronchial Epithelial Cells

2021 ◽  
Author(s):  
Parameet Kumar ◽  
Dharmendra Kumar Soni ◽  
Chaitali Sen ◽  
Mads B Larsen ◽  
Krystyna Mazan-Mamczarz ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Epithelial Cells ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Regulation Of Gene Expression ◽  
Lung Epithelial Cells ◽  
Regulation Of Expression ◽  
Trafficking Defects ◽  
And Function

Abstract Cystic Fibrosis (CF) occurs as a result of mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which lead to misfolding, trafficking defects, and impaired function of the CFTR protein. Splicing factor proline/glutamine-rich (SFPQ) is a multifunctional nuclear RNA-binding protein (RBP) implicated in the regulation of gene expression pathways and intracellular trafficking. Here, we investigated the role of SFPQ in the regulation of the expression and function of F508del-CFTR in CF lung epithelial cells. We find that the expression of SFPQ is reduced in F508del-CFTR CF epithelial cells compared to WT-CFTR control cells. Interestingly, the overexpression of SFPQ in CF cells increases the expression as well as rescues the function of F508del-CFTR. Further, comprehensive transcriptome analyses indicate that SFPQ plays a key role in activating the mutant F508del-CFTR by modulating several cellular signaling pathways. This is the first report on the role of SFPQ in the regulation of expression and function of F508del-CFTR in CF lung disease. Our findings provide new insights into SFPQ-mediated molecular mechanisms and point to possible novel epigenetic therapeutic targets for CF and related pulmonary diseases.

scholarly journals Effect of nerve growth factor on the proliferation in newborn bovine testicular Sertoli cells

Reproduction ◽  
2020 ◽  
Vol 160 (3) ◽  
pp. 405-415
Author(s):  
Qiaoge Niu ◽  
Maosheng Cao ◽  
Chenfeng Yuan ◽  
Yuwen Huang ◽  
Zijiao Zhao ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Nerve Growth Factor ◽  
Growth Factor ◽  
Signaling Pathways ◽  
Molecular Mechanisms ◽  
Male Reproduction ◽  
Nerve Growth ◽  
And Function

Nerve growth factor (NGF) has been proved to play important roles in male reproductive physiology, but the molecular mechanisms of NGF action remain unclear. In this study, the effects of NGF on the growth of newborn bovine testicular Sertoli (NBS) cells and the related signaling pathways were investigated. The NBS cells were treated in vitro with NGF (100 ng/mL) for 18 h. The expression levels of cell proliferation related genes, INHBB, and cytoplasmic specialization related gene were determined using real-time PCR and Western blot. The roles of PI3K/AKT and MAPK/ERK pathways in NGF-induced cell proliferation were investigated. It was found that NGF regulates proliferation and function of NBS cells via its receptor NTRK1 by activating the PI3K/ATK and MAPK/ERK signaling pathways. The study will help to further understand the role of NGF in male reproduction and provide new therapeutic targets for reproductive dysfunctions in male animals.

scholarly journals Molecular Mechanisms and Epigenetic Regulation in Diabetic Cardiomyopathy

2021 ◽  
Vol 8 ◽  
Author(s):  
Anupam Mittal ◽  
Rajni Garg ◽  
Ajay Bahl ◽  
Madhu Khullar
Keyword(s):  
Diabetic Cardiomyopathy ◽  
Molecular Mechanisms ◽  
Cardiac Metabolism ◽  
Molecular Pathways ◽  
Myocardial Apoptosis ◽  
Epigenetic Modifiers ◽  
Artery Disease ◽  
And Function ◽  
Lifestyle Disease

Diabetes mellitus (DM) is an important lifestyle disease. Type 2 diabetes is one of the prime contributors to cardiovascular diseases (CVD) and diabetic cardiomyopathy (DbCM) and leads to increased morbidity and mortality in patients with DM. DbCM is a typical cardiac disease, characterized by cardiac remodeling in the presence of DM and in the absence of other comorbidities such as hypertension, valvular diseases, and coronary artery disease. DbCM is associated with defective cardiac metabolism, altered mitochondrial structure and function, and other physiological and pathophysiological signaling mechanisms such as oxidative stress, inflammation, myocardial apoptosis, and autophagy. Epigenetic modifiers are crucial players in the pathogenesis of DbCM. Thus, it is important to explore the role of epigenetic modifiers or modifications in regulating molecular pathways associated with DbCM. In this review, we have discussed the role of various epigenetic mechanisms such as histone modifications (acetylation and methylation), DNA methylation and non-coding RNAs in modulating molecular pathways involved in the pathophysiology of the DbCM.

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