The Endocannabinoid Peptide RVD-Hemopressin Is a TRPV1 Channel Blocker.

Neurotransmission is critical for brain function, allowing neurons to communicate through neurotransmitters and neuropeptides. RVD-hemopressin (RVD-Hp), a novel peptide identified in noradrenergic neurons, modulates cannabinoid receptors CB1 and CB2. Unlike hemopressin (Hp), which induces anxiogenic behaviors via transient receptor potential vanilloid 1 (TRPV1) activation, RVD-Hp counteracts these effects, suggesting that it may block TRPV1.

Essential role of Mg in mouse preimplantation embryo development revealed by TRPM7 chanzyme-deficient gametes.

TRPM7 (transient receptor potential cation channel subfamily M member 7) is a chanzyme with channel and kinase domains essential for embryo development. Using gamete-specific Trpm7-null lines, we report that TRPM7-mediated Mg influx is indispensable for reaching the blastocyst stage. TRPM7 is expressed dynamically from gametes to blastocysts; displays stage-specific localization on the plasma membrane, cytoplasm, and nucleus; and undergoes cleavage that produces C-terminal kinase fragments.

Hypoxic Regulation of the Large-Conductance, Calcium and Voltage-Activated Potassium Channel, BK.

Hypoxia is a condition characterized by a reduction of cellular oxygen levels derived from alterations in oxygen balance. Hypoxic events trigger changes in cell-signaling cascades, oxidative stress, activation of pro-inflammatory molecules, and growth factors, influencing the activity of various ion channel families and leading to diverse cardiovascular diseases such as myocardial infarction, ischemic stroke, and hypertension. The large-conductance, calcium and voltage-activated potassium channel (BK) has a central role in the mechanism of oxygen (O) sensing and its activity has been related to the hypoxic response.

Knockin' on Egg's Door: Maternal Control of Egg Activation That Influences Cortical Granule Exocytosis in Animal Species.

Fertilization by multiple sperm leads to lethal chromosomal number abnormalities, failed embryo development, and miscarriage. In some vertebrate and invertebrate eggs, the so-called cortical reaction contributes to their activation and prevents polyspermy during fertilization. This process involves biogenesis, redistribution, and subsequent accumulation of cortical granules (CGs) at the female gamete cortex during oogenesis.

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

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.

RGD-binding integrins and TGF-β in SARS-CoV-2 infections - novel targets to treat COVID-19 patients?

The new coronavirus SARS-CoV-2 is a global pandemic and a severe public health crisis. SARS-CoV-2 is highly contagious and shows high mortality rates, especially in elderly and patients with pre-existing medical conditions. At the current stage, no effective drugs are available to treat these patients.

TRPM8 Channel Promotes the Osteogenic Differentiation in Human Bone Marrow Mesenchymal Stem Cells.

Various families of ion channels have been characterized in mesenchymal stem cells (MSCs), including some members of transient receptor potential (TRP) channels family. TRP channels are involved in critical cellular processes as differentiation and cell proliferation. Here, we analyzed the expression of TRPM8 channel in human bone marrow MSCs (hBM-MSCs), and its relation with osteogenic differentiation.

Divalent cation influx and calcium homeostasis in germinal vesicle mouse oocytes.

Prior to maturation, mouse oocytes are arrested at the germinal vesicle (GV) stage during which they experience constitutive calcium (Ca) influx and spontaneous Ca oscillations. The oscillations cease during maturation but Ca influx continues, as the oocytes' internal stores attain maximal content at the culmination of maturation, the metaphase II stage. The identity of the channel(s) that underlie this Ca influx has not been completely determined.

TRPM7 and Ca3.2 channels mediate Ca influx required for egg activation at fertilization.

The success of mammalian development following fertilization depends on a series of transient increases in egg cytoplasmic Ca, referred to as Ca oscillations. Maintenance of these oscillations requires Ca influx across the plasma membrane, which is mediated in part by T-type, Ca3.2 channels.

Ion Channel Function During Oocyte Maturation and Fertilization.

The proper maturation of both male and female gametes is essential for supporting fertilization and the early embryonic divisions. In the ovary, immature fully-grown oocytes that are arrested in prophase I of meiosis I are not able to support fertilization. Acquiring fertilization competence requires resumption of meiosis which encompasses the remodeling of multiple signaling pathways and the reorganization of cellular organelles.

Conotoxins as Tools to Understand the Physiological Function of Voltage-Gated Calcium (Ca) Channels.

Voltage-gated calcium (Ca) channels are widely expressed and are essential for the completion of multiple physiological processes. Close regulation of their activity by specific inhibitors and agonists become fundamental to understand their role in cellular homeostasis as well as in human tissues and organs. Ca channels are divided into two groups depending on the membrane potential required to activate them: High-voltage activated (HVA, Ca1.

Small and Intermediate Calcium-Activated Potassium Channel Openers Improve Rat Endothelial and Erectile Function.

Modulation of endothelial calcium-activated potassium (K) channels has been proposed as an approach to restore endothelial function. The present study investigated whether novel openers of K channels with small (K2.x) and intermediate (K3.

TRPM7-like channels are functionally expressed in oocytes and modulate post-fertilization embryo development in mouse.

The Transient Receptor Potential (TRP) channels are a family of cationic ion channels widely distributed in mammalian tissues. In general, the global genetic disruption of individual TRP channels result in phenotypes associated with impairment of a particular tissue and/or organ function. An exception is the genetic ablation of the TRP channel TRPM7, which results in early embryonic lethality.

TRPV3 channels mediate Ca²⁺ influx induced by 2-APB in mouse eggs.

Fertilization in mammals is initiated when a sperm fuses with a mature MII oocyte, also known as egg, and triggers a plethora of finely controlled processes identified as egg activation. The completion of all events of egg activation is driven by and depends on a series of repetitive calcium (Ca(2+)) increases (Ca(2+) oscillations), which rely on Ca(2+) influx from the extracellular media. Ca(2+) channels on the egg plasma membrane (PM) are thought to mediate this influx.

TRPV3 channels mediate strontium-induced mouse-egg activation.

In mammals, calcium influx is required for oocyte maturation and egg activation. The molecular identities of the calcium-permeant channels that underlie the initiation of embryonic development are not established. Here, we describe a transient receptor potential (TRP) ion channel current activated by TRP agonists that is absent in TrpV3(-/-) eggs.

An aqueous H+ permeation pathway in the voltage-gated proton channel Hv1.

Hv1 voltage-gated proton channels mediate rapid and selective transmembrane H(+) flux and are gated by both voltage and pH gradients. Selective H(+) transfer in membrane proteins is commonly achieved by Grotthuss proton 'hopping' in chains of ionizable amino acid side chains and intraprotein water molecules. To identify whether ionizable residues are required for proton permeation in Hv1, we neutralized candidate residues and measured expressed voltage-gated H(+) currents.

[Factors associated with access to health services prior to pregnancy by pregnant adolescents].

Objective: To assess determinants of access to primary care services prior to pregnancy by pregnant adolescents.

Methods: Theory-based cross-sectional study conducted to examine access to heath services at five dimensions: geographic, economic, administrative, psychosocial and information. There were included in the study 200 first-time pregnant adolescents (aged 10 to 19 years) who attended a primary care unit in the municipality of Indaiatuba, Southeastern Brazil, in 2003.

[Knowledge of pregnant adolescents about reproductive anatomy and physiology in a municipality of Southern Brazil].

Objectives: To study knowledge of some aspects of the female reproductive anatomy and physiology and their association with socio-demographic and reproductive "choices" of pregnant adolescents.

Methods: A cross-sectional study was performed with 200 first time pregnant adolescents who attended a public women's health clinic in the municipality of Indaiatuba, Sao Paulo, Brazil. During their first prenatal care visit, face-to-face interviews were conducted using a structured questionnaire and a three-dimensional handmade female model.

Intrinsic electrostatic potential in the BK channel pore: role in determining single channel conductance and block.

The internal vestibule of large-conductance Ca(2+) voltage-activated K(+) (BK) channels contains a ring of eight negative charges not present in K(+) channels of lower conductance (Glu386 and Glu389 in hSlo) that modulates channel conductance through an electrostatic mechanism (Brelidze, T.I., X.

A marriage of convenience: beta-subunits and voltage-dependent K+ channels.

The movement of ions across cell membranes is essential for a wide variety of fundamental physiological processes, including secretion, muscle contraction, and neuronal excitation. This movement is possible because of the presence in the cell membrane of a class of integral membrane proteins dubbed ion channels. Ion channels, thanks to the presence of aqueous pores in their structure, catalyze the passage of ions across the otherwise ion-impermeable lipid bilayer.

Structural determinants for functional coupling between the beta and alpha subunits in the Ca2+-activated K+ (BK) channel.

High conductance, calcium- and voltage-activated potassium (BK, MaxiK) channels are widely expressed in mammals. In some tissues, the biophysical properties of BK channels are highly affected by coexpression of regulatory (beta) subunits. The most remarkable effects of beta1 and beta2 subunits are an increase of the calcium sensitivity and the slow down of channel kinetics.