scholarly journals Simultaneous Deletion of Transient Receptor Potential Vanilloid 3 and Cacna1h Undermines Ca2+ Homeostasis in Oocytes and Fertility in Mice

2018 ◽  
Author(s):  
Aujan Mehregan ◽  
Goli Ardestani ◽  
Ingrid Carvacho ◽  
Rafael Fissore
Keyword(s):  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Functional Expression ◽  
Egg Activation ◽  
Transient Receptor Potential Vanilloid ◽  
Double Knockout ◽  
Knock Out ◽  
Transient Receptor ◽  
Mammalian Eggs ◽  
Channel Currents

In mammals, calcium (Ca2+) influx fills the endoplasmic reticulum, from where Ca2+ is released following fertilization to induce egg activation. However, an incomplete index of the plasma membrane channels and their specific contributions that underlie this influx in oocytes and eggs led us to simultaneously knock out the transient receptor potential vanilloid, member 3 (TRPV3) channel and the T-type channel, CaV3.2. Double knockout (dKO) females displayed subfertility and their oocytes and eggs showed significantly diminished Ca2+ store content and oscillations after fertilization compared to controls. We also found that the cell cycle stage during maturation determines the functional expression of channels whereby they show a distinct permeability to certain ions. In total, we demonstrate that TRPV3 and CaV3.2 are required for initiating physiological oscillations and that Ca2+ influx dictates the periodicity of oscillations during fertilization. dKO gametes will be indispensable to identify the complete native channel currents present in mammalian eggs.

scholarly journals Deletion of TRPV3 and CaV3.2 T-type channels in mice undermines fertility and Ca2+ homeostasis in oocytes and eggs

2021 ◽  
Author(s):  
Aujan Mehregan ◽  
Goli Ardestani ◽  
Hiroki Akizawa ◽  
Ingrid Carvacho ◽  
Rafael Fissore
Keyword(s):  
Divalent Cation ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Egg Activation ◽  
Transient Receptor Potential Vanilloid ◽  
Double Knockout ◽  
Complete Filling ◽  
Sperm Entry ◽  
Mammalian Fertilization ◽  
Transient Receptor

Calcium (Ca2+) influx during oocyte maturation and after sperm entry is necessary to fill the internal Ca2+ stores and for complete egg activation. We knocked out the transient receptor potential vanilloid member 3 (TRPV3) and the T-type channel, CaV3.2 to determine their necessity for maintaining these functions in mammalian oocytes/eggs. Double knockout (dKO) females were subfertile, their oocytes and eggs showed reduced internal Ca2+ stores, and following sperm entry or PLCz cRNA injection, fewer dKO eggs displayed Ca2+ responses compared to wildtype (WT) eggs, which were also of lower frequency. These parameters were rescued and/or enhanced by removing extracellular Mg2+, suggesting the residual Ca2+ influx could be mediated by the TRPM7 channel, consistent with the termination of divalent-cation oscillations in dKO eggs by a TRPM7 inhibitor. In total, we demonstrated that TRPV3 and CaV3.2 mediate the complete filling of the Ca2+ stores in mouse oocytes and eggs. We also show they are required for initiating and maintaining regularly spaced-out oscillations, suggesting that Ca2+ influx through PM ion channels dictates the periodicity and persistence of Ca2+ oscillations during mammalian fertilization.

scholarly journals Combined genetic and pharmacological inhibition of TRPV1 and P2X3 attenuates colorectal hypersensitivity and afferent sensitization

2013 ◽  
Vol 305 (9) ◽  
pp. G638-G648 ◽  
Author(s):  
Michael E. Kiyatkin ◽  
Bin Feng ◽  
Erica S. Schwartz ◽  
G. F. Gebhart
Keyword(s):  
Transient Receptor Potential ◽  
Genetic Manipulation ◽  
Afferent Fiber ◽  
Receptor Potential ◽  
Afferent Neuron ◽  
Transient Receptor Potential Vanilloid ◽  
Double Knockout ◽  
Inflammatory Soup ◽  
Trpv1 Antagonist ◽  
Transient Receptor

The ligand-gated channels transient receptor potential vanilloid 1 (TRPV1) and P2X3 have been reported to facilitate colorectal afferent neuron sensitization, thus contributing to organ hypersensitivity and pain. In the present study, we hypothesized that TRPV1 and P2X3 cooperate to modulate colorectal nociception and afferent sensitivity. To test this hypothesis, we employed TRPV1-P2X3 double knockout (TPDKO) mice and channel-selective pharmacological antagonists and evaluated combined channel contributions to behavioral responses to colorectal distension (CRD) and afferent fiber responses to colorectal stretch. Baseline responses to CRD were unexpectedly greater in TPDKO compared with control mice, but zymosan-produced CRD hypersensitivity was absent in TPDKO mice. Relative to control mice, proportions of mechanosensitive and -insensitive pelvic nerve afferent classes were not different in TPDKO mice. Responses of mucosal and serosal class afferents to mechanical probing were unaffected, whereas responses of muscular (but not muscular/mucosal) afferents to stretch were significantly attenuated in TPDKO mice; sensitization of both muscular and muscular/mucosal afferents by inflammatory soup was also significantly attenuated. In pharmacological studies, the TRPV1 antagonist A889425 and P2X3 antagonist TNP-ATP, alone and in combination, applied onto stretch-sensitive afferent endings attenuated responses to stretch; combined antagonism produced greater attenuation. In the aggregate, these observations suggest that 1) genetic manipulation of TRPV1 and P2X3 leads to reduction in colorectal mechanosensation peripherally and compensatory changes and/or disinhibition of other channels centrally, 2) combined pharmacological antagonism produces more robust attenuation of mechanosensation peripherally than does antagonism of either channel alone, and 3) the relative importance of these channels appears to be enhanced in colorectal hypersensitivity.

scholarly journals Functional coupling between TRPV4 channel and TMEM16F modulates human trophoblast fusion

2021 ◽  
Author(s):  
Yang Zhang ◽  
Pengfei Liang ◽  
Ke Zoe Shan ◽  
Liping Feng ◽  
Yong Chen ◽  
...  
Keyword(s):  
Cell Fusion ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Functional Expression ◽  
Activation Mechanism ◽  
Functional Coupling ◽  
Transient Receptor Potential Vanilloid ◽  
Human Trophoblast ◽  
Phospholipid Scramblase ◽  
Transient Receptor

TMEM16F, a Ca2+-activated phospholipid scramblase (CaPLSase), is critical for placental trophoblast syncytialization, HIV infection, and SARS-CoV2-mediated syncytialization. How TMEM16F is activated during cell fusion is unclear. Here, we used trophoblasts as a model for cell fusion and demonstrated that Ca2+ influx through Ca2+ permeable transient receptor potential vanilloid channel TRPV4 is critical for TMEM16F activation and subsequent human trophoblast fusion. GSK1016790A, a TRPV4 specific agonist, robustly activates TMEM16F in trophoblasts. Patch-clamp electrophysiology demonstrated that TRPV4 and TMEM16F are functionally coupled within Ca2+ microdomains in human trophoblasts. Pharmacological inhibition or gene silencing of TRPV4 hindered TMEM16F activation and subsequent trophoblast syncytialization. Our study uncovers the functional expression of TRPV4 and a physiological activation mechanism of TMEM16F in human trophoblasts, thus providing us with novel strategies to regulate CaPLSase activity as a critical checkpoint of physiologically- and disease-relevant cell fusion events.

Functional Expression of an Osmosensitive Cation Channel, Transient Receptor Potential Vanilloid 4, in Rat Vestibular Ganglia

2016 ◽  
Vol 21 (4) ◽  
pp. 268-274 ◽  
Author(s):  
Takefumi Kamakura ◽  
Makoto Kondo ◽  
Yoshihisa Koyama ◽  
Yukiko Hanada ◽  
Yusuke Ishida ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Functional Expression ◽  
Ruthenium Red ◽  
Cation Channel ◽  
Trigeminal Ganglia ◽  
Transient Receptor Potential Vanilloid ◽  
Trpv Channels ◽  
Polymerase Chain ◽  
Transient Receptor

Transient receptor potential vanilloid (TRPV) 4 is a nonselective cation channel expressed in sensory neurons such as those in the dorsal root and trigeminal ganglia, kidney, and inner ear. TRPV4 is activated by mechanical stress, heat, low osmotic pressure, low pH, and phorbol derivatives such as 4α-phorbol 12,13-didecanoate (4α-PDD). We investigated the expression of TRPV4 in rat vestibular ganglion (VG) neurons. The TRPV4 gene was successfully amplified from VG neuron mRNA using reverse-transcription polymerase chain reaction. Furthermore, immunoblotting showed positive expression of TRPV4 protein in VG neurons. Immunohistochemistry indicated that TRPV4 was localized predominantly on the plasma membrane of VG neurons. Calcium (Ca2+) imaging of VG neurons showed that 4α-PDD and/or hypotonic stimuli caused an increase in intracellular Ca2+ concentration ([Ca2+]i) that was almost completely inhibited by ruthenium red, a selective antagonist of TRPV channels. Interestingly, a [Ca2+]i increase was evoked by both hypotonic stimuli and 4α-PDD in approximately 38% of VG neurons. These data indicate that TRPV4 is functionally expressed in VG neurons as an ion channel and that TRPV4 likely participates in VG neurons for vestibular neurotransmission as an osmoreceptor and/or mechanoreceptor.

scholarly journals Interaction between TRPV1-expressing neurons in the hypothalamus

2019 ◽  
Vol 121 (1) ◽  
pp. 140-151 ◽  
Author(s):  
Adrien J. R. Molinas ◽  
Lucie D. Desmoulins ◽  
Brooke V. Hamling ◽  
Sierra M. Butcher ◽  
Imran J. Anwar ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Direct Interaction ◽  
Receptor Potential ◽  
Functional Expression ◽  
Hypothalamic Nucleus ◽  
Transient Receptor Potential Vanilloid ◽  
Adult Mice ◽  
Hypothalamic Nuclei ◽  
Transient Receptor

Transient receptor potential vanilloid type 1 (TRPV1) is a ligand-gated ion channel expressed in the peripheral and central nervous systems. TRPV1-dependent mechanisms take part in a wide range of physiological and pathophysiological pathways including the regulation of homeostatic functions. TRPV1 expression in the hypothalamus has been described as well as evidence that TRPV1-dependent excitatory inputs to hypothalamic preautonomic neurons are diminished in diabetic conditions. Here we aimed to determine the functional expression of TRPV1 in two hypothalamic nuclei known to be involved in the central control of metabolism and to test the hypothesis that TRPV1-expressing neurons receive TRPV1-expressing inputs. A mouse model (TRPV1Cre/tdTom) was generated to identify TRPV1-expressing cells and determine the cellular properties of TRPV1-expressing neurons in adult mice. Our study demonstrated the functional expression of TRPV1 in the dorsomedial hypothalamic nucleus and paraventricular nucleus in adult mice. Our findings revealed that a subset of TRPV1Cre/tdTom neurons receive TRPV1-expressing excitatory inputs, indicating direct interaction between TRPV1-expressing neurons. In addition, astrocytes likely play a role in the modulation of TRPV1-expressing neurons. In summary, this study identified specific hypothalamic regions where TRPV1 is expressed and functional in adult mice and the existence of direct connections between TRPV1Cre/tdTom neurons. NEW & NOTEWORTHY Transient receptor potential vanilloid type 1 (TRPV1) is expressed in the hypothalamus, and TRPV1-dependent regulation of preautonomic neurons is decreased in hyperglycemic conditions. Our study demonstrated functional expression of TRPV1 in two hypothalamic nuclei involved in the control of energy homeostasis. Our results also revealed that a subset of TRPV1-expressing neurons receive TRPV1-expressing excitatory inputs. These findings suggest direct interaction between TRPV1-expressing neurons.

scholarly journals Transient receptor potential vanilloid 1 and 4 double knockout leads to increased bone mass in mice

Bone Reports ◽  
2020 ◽  
Vol 12 ◽  
pp. 100268 ◽  
Author(s):  
Haruki Nishimura ◽  
Makoto Kawasaki ◽  
Manabu Tsukamoto ◽  
Kunitaka Menuki ◽  
Hitoshi Suzuki ◽  
...  
Keyword(s):  
Bone Mass ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Transient Receptor Potential Vanilloid ◽  
Double Knockout ◽  
Transient Receptor

scholarly journals Increased TRPV4 expression in non-myelinating Schwann cells is associated with demyelination after sciatic nerve injury

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Xiaona Feng ◽  
Yasunori Takayama ◽  
Nobuhiko Ohno ◽  
Hirosato Kanda ◽  
Yi Dai ◽  
...  
Keyword(s):  
Nervous System ◽  
Sciatic Nerve ◽  
Schwann Cells ◽  
Nerve Injury ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Functional Expression ◽  
Transient Receptor Potential Vanilloid ◽  
Sciatic Nerves ◽  
Transient Receptor

AbstractTransient receptor potential vanilloid 4 (TRPV4) is a non-selective calcium-permeable cation channel that is widely expressed and activated in various neurons and glial cells in the nervous system. Schwann cells (SCs) are primary glia cells that wrap around axons to form the myelin sheath in the peripheral nervous system. However, whether TRPV4 is expressed and functions in SCs is unclear. Here, we demonstrate functional expression of TRPV4 in mouse SCs and investigated its physiological significance. Deletion of TRPV4 did not affect normal myelin development for SCs in sciatic nerves in mice. However, after sciatic nerve cut injury, TRPV4 expression levels were remarkably increased in SCs following nerve demyelination. Ablation of TRPV4 expression impaired the demyelinating process after nerve injury, resulting in delayed remyelination and functional recovery of sciatic nerves. These results suggest that local activation of TRPV4 could be an attractive pharmacological target for therapeutic intervention after peripheral nerve injury.

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