Polyacrylic-Coated Solid Nanoparticles Increase the Aquaporin Permeability to Hydrogen Peroxide.

Aquaporins (AQPs) allow the diffusion of hydrogen peroxide (HO) and act as ROS scavenging systems, which are important for controlling the redox state of cells. Recently, cerium oxide nanoparticles were found to increase the water and HO permeability by modulating AQPs. To further analyze the action of nanoparticles (NPs) on AQP, we examined the effect of the NPs presenting different core compositions (CeO, GdO, FeO, and TiO), hydrodynamic sizes, and surface functionalization.

Sigma receptor and aquaporin modulators: chiral resolution, configurational assignment, and preliminary biological profile of RC752 enantiomers.

The key role of chiral small molecules in drug discovery programs has been deeply investigated throughout last decades. In this context, our previous studies highlighted the influence of the absolute configuration of different stereocenters on the pharmacokinetic, pharmacodynamic and functional properties of promising Sigma receptor (SR) modulators. Thus, starting from the racemic SR ligand RC752, we report herein the isolation of the enantiomers via enantioselective separation with both HPLC and SFC.

Discovery of RC-752, a Novel Sigma-1 Receptor Antagonist with Antinociceptive Activity: A Promising Tool for Fighting Neuropathic Pain.

Neuropathic pain (NP) is a chronic condition resulting from damaged pain-signaling pathways. It is a debilitating disorder that affects up to 10% of the world's population. Although opioid analgesics are effective in reducing pain, they present severe risks; so, there is a pressing need for non-opioid pain-relieving drugs.

Allyl Isothiocianate Induces Ca Signals and Nitric Oxide Release by Inducing Reactive Oxygen Species Production in the Human Cerebrovascular Endothelial Cell Line hCMEC/D3.

Nitric oxide (NO) represents a crucial mediator to regulate cerebral blood flow (CBF) in the human brain both under basal conditions and in response to somatosensory stimulation. An increase in intracellular Ca concentrations ([Ca]) stimulates the endothelial NO synthase to produce NO in human cerebrovascular endothelial cells. Therefore, targeting the endothelial ion channel machinery could represent a promising strategy to rescue endothelial NO signalling in traumatic brain injury and neurodegenerative disorders.

Transient receptor potential ankyrin 1 (TRPA1) mediates reactive oxygen species-induced Ca entry, mitochondrial dysfunction, and caspase-3/7 activation in primary cultures of metastatic colorectal carcinoma cells.

Colorectal carcinoma (CRC) represents the fourth most common cancer worldwide and is the third most common cause of malignancy-associated mortality. Distant metastases to the liver and lungs are the main drivers of CRC-dependent death. Pro-oxidant therapies, which halt disease progression by exacerbating oxidative stress, represent an antitumour strategy that is currently exploited by chemotherapy and ionizing radiation.

Cerium Oxide Nanoparticles Regulate Oxidative Stress in HeLa Cells by Increasing the Aquaporin-Mediated Hydrogen Peroxide Permeability.

Some aquaporins (AQPs) allow the diffusion of hydrogen peroxide (HO), the most abundant ROS, through the cell membranes. Therefore, the possibility of regulating the AQP-mediated permeability to HO, and thus ROS scavenging, appears particularly important for controlling the redox state of cells in physiological and pathophysiological conditions. Several compounds have been screened and characterized for this purpose.

Histamine activates an intracellular Ca signal in normal human lung fibroblast WI-38 cells.

Histamine is an inflammatory mediator that can be released from mast cells to induce airway remodeling and cause persistent airflow limitation in asthma. In addition to stimulating airway smooth muscle cell constriction and hyperplasia, histamine promotes pulmonary remodeling by inducing fibroblast proliferation, contraction, and migration. It has long been known that histamine receptor 1 (H1R) mediates the effects of histamine on human pulmonary fibroblasts through an increase in intracellular Ca concentration ([Ca]), but the underlying signaling mechanisms are still unknown.

Aquaporin-6 May Increase the Resistance to Oxidative Stress of Malignant Pleural Mesothelioma Cells.

Malignant pleural mesothelioma (MPM) is an aggressive cancer of the pleural surface and is associated with previous asbestos exposure. The chemotherapy drug is one of the main treatments, but the median survival ranges from 8 to 14 months from diagnosis. The redox homeostasis of tumor cells should be carefully considered since elevated levels of ROS favor cancer cell progression (proliferation and migration), while a further elevation leads to ferroptosis.

Non-Linear Frequency Dependence of Neurovascular Coupling in the Cerebellar Cortex Implies Vasodilation-Vasoconstriction Competition.

Neurovascular coupling (NVC) is the process associating local cerebral blood flow (CBF) to neuronal activity (NA). Although NVC provides the basis for the blood oxygen level dependent (BOLD) effect used in functional MRI (fMRI), the relationship between NVC and NA is still unclear. Since recent studies reported cerebellar non-linearities in BOLD signals during motor tasks execution, we investigated the NVC/NA relationship using a range of input frequencies in acute mouse cerebellar slices of vermis and hemisphere.

Sigma-1 Receptor Agonists Acting on Aquaporin-Mediated HO Permeability: New Tools for Counteracting Oxidative Stress.

Sigma1 Receptor (S1R) is involved in oxidative stress, since its activation is triggered by oxidative or endoplasmic reticulum stress. Since specific aquaporins (AQP), called peroxiporins, play a relevant role in controlling HO permeability and ensure reactive oxygen species wasted during oxidative stress, we studied the effect of S1R modulators on AQP-dependent water and hydrogen peroxide permeability in the presence and in the absence of oxidative stress. Applying stopped-flow light scattering and fluorescent probe methods, water and hydrogen peroxide permeability in HeLa cells have been studied.

NMDA receptors elicit flux-independent intracellular Ca signals via metabotropic glutamate receptors and flux-dependent nitric oxide release in human brain microvascular endothelial cells.

The excitatory neurotransmitter glutamate gates post-synaptic N-methyl-d-aspartate (NMDA) receptors (NMDARs) to mediate extracellular Ca entry and stimulate neuronal nitric oxide (NO) synthase to release NO and trigger neurovascular coupling (NVC). Neuronal and glial NMDARs may also operate in a flux-independent manner, although it is unclear whether their non-ionotropic mode of action is involved in NVC. Recently, endothelial NMDARs were found to trigger Ca-dependent NO production and induce NVC, but the underlying mode of signaling remains elusive.

Human sperm functioning is related to the aquaporin-mediated water and hydrogen peroxide transport regulation.

Aquaporins (AQPs) are transmembrane water channels and some of them are permeable in addition to water to other small solutes including hydrogen peroxide. The sperm cells of mammals and fishes express different AQPs, although there is no agreement in the literature on their localization. In humans, AQP3 and AQP11 are expressed mainly in the tail, AQP7 in the head and AQP8 in the midpiece.

Manuka Honey Induces Apoptosis of Epithelial Cancer Cells through Aquaporin-3 and Calcium Signaling.

Honey is a natural product with a long use in traditional medicine and is well recognized to regulate different biological events. It is an important source of various biological or pharmacological molecules and, therefore, there is a strong interest to explore their properties. Evidence is growing that honey may have the potential to be an anticancer agent acting through several mechanisms.

Setup and Validation of a Reliable Docking Protocol for the Development of Neuroprotective Agents by Targeting the Sigma-1 Receptor (S1R).

Sigma-1 receptor (S1R) is a promising molecular target for the development of novel effective therapies against neurodegenerative diseases. To speed up the discovery of new S1R modulators, herein we report the development of a reliable in silico protocol suitable to predict the affinity of small molecules against S1R. The docking method was validated by comparing the computational calculated values of a test set of new aryl-aminoalkyl-ketone with experimental determined binding affinity.

Nicotinic acid adenine dinucleotide phosphate activates two-pore channel TPC1 to mediate lysosomal Ca release in endothelial colony-forming cells.

Nicotinic acid adenine dinucleotide phosphate (NAADP) is the most recently discovered Ca -releasing messenger that increases the intracellular Ca concentration by mobilizing the lysosomal Ca store through two-pore channels 1 (TPC1) and 2 (TPC2). NAADP-induced lysosomal Ca release regulates multiple endothelial functions, including nitric oxide release and proliferation. A sizeable acidic Ca pool endowed with TPC1 is also present in human endothelial colony-forming cells (ECFCs), which represent the only known truly endothelial precursors.

HPV Infection Affects Human Sperm Functionality by Inhibition of Aquaporin-8.

Human sperm cells express different aquaporins (AQPs), AQP3, 7, 8, 11, which are localized both in the plasma membrane and in intracellular structures. Besides cell volume regulation and end stage of cytoplasm removal during sperm maturation, the role of AQPs extends also to reactive oxygen species (ROS) elimination. Moreover, oxidative stress has been shown to inhibit AQP-mediated HO permeability.

Parameter tuning differentiates granule cell subtypes enriching transmission properties at the cerebellum input stage.

The cerebellar granule cells (GrCs) are classically described as a homogeneous neuronal population discharging regularly without adaptation. We show that GrCs in fact generate diverse response patterns to current injection and synaptic activation, ranging from adaptation to acceleration of firing. Adaptation was predicted by parameter optimization in detailed computational models based on available knowledge on GrC ionic channels.

Group 1 metabotropic glutamate receptors trigger glutamate-induced intracellular Ca signals and nitric oxide release in human brain microvascular endothelial cells.

Neurovascular coupling (NVC) is the mechanism whereby an increase in neuronal activity causes an increase in local cerebral blood flow (CBF) to ensure local supply of oxygen and nutrients to the activated areas. The excitatory neurotransmitter glutamate gates post-synaptic N-methyl-D-aspartate receptors to mediate extracellular Ca entry and stimulate neuronal nitric oxide (NO) synthase to release NO, thereby triggering NVC. Recent work suggested that endothelial Ca signals could underpin NVC by recruiting the endothelial NO synthase.

Histamine induces intracellular Ca oscillations and nitric oxide release in endothelial cells from brain microvascular circulation.

The neuromodulator histamine is able to vasorelax in human cerebral, meningeal and temporal arteries via endothelial histamine 1 receptors (H Rs) which result in the downstream production of nitric oxide (NO), the most powerful vasodilator transmitter in the brain. Although endothelial Ca signals drive histamine-induced NO release throughout the peripheral circulation, the mechanism by which histamine evokes NO production in human cerebrovascular endothelial cells is still unknown. Herein, we exploited the human cerebral microvascular endothelial cell line, hCMEC/D3, to assess the role of intracellular Ca signaling in histamine-induced NO release.

Propolis Induces AQP3 Expression: A Possible Way of Action in Wound Healing.

Propolis is the generic name of a complex of resinous compound collected by honeybees and it has been utilized for many years in folk medicine. As other products generated by honeybees (such as royal jelly, pollen, honey), propolis has great therapeutic properties, but very little scientific information is available. Therefore, this study was aimed at exploring the potential wound healing properties of propolis.

Nicotinic Acid Adenine Dinucleotide Phosphate (NAADP) Induces Intracellular Ca Release through the Two-Pore Channel TPC1 in Metastatic Colorectal Cancer Cells.

Nicotinic acid adenine dinucleotide phosphate (NAADP) gates two-pore channels 1 and 2 (TPC1 and TPC2) to elicit endo-lysosomal (EL) Ca release. NAADP-induced EL Ca signals may be amplified by the endoplasmic reticulum (ER) through the Ca-induced Ca release mechanism (CICR). Herein, we aimed at assessing for the first time the role of EL Ca signaling in primary cultures of human metastatic colorectal carcinoma (mCRC) by exploiting Ca imaging and molecular biology techniques.

Honey-Mediated Wound Healing: H₂O₂ Entry through AQP3 Determines Extracellular Ca Influx.

Since Biblical times, honey has been utilized in "folk medicine", and in recent decades the positive qualities of honey have been re-discovered and are gaining acceptance. Scientific literature states that honey has been successfully utilized on infections not responding to classic antiseptic and antibiotic therapy, because of its intrinsic H₂O₂ production. In our study, we demonstrated the involvement of H₂O₂ as a main mediator of honey regenerative effects on an immortalized human keratinocyte cell line.

Human adipose glycerol flux is regulated by a pH gate in AQP10.

Obesity is a major threat to global health and metabolically associated with glycerol homeostasis. Here we demonstrate that in human adipocytes, the decreased pH observed during lipolysis (fat burning) correlates with increased glycerol release and stimulation of aquaglyceroporin AQP10. The crystal structure of human AQP10 determined at 2.

Muscarinic M5 receptors trigger acetylcholine-induced Ca signals and nitric oxide release in human brain microvascular endothelial cells.

Basal forebrain neurons control cerebral blood flow (CBF) by releasing acetylcholine (Ach), which binds to endothelial muscarinic receptors to induce nitric (NO) release and vasodilation in intraparenchymal arterioles. Nevertheless, the mechanism whereby Ach stimulates human brain microvascular endothelial cells to produce NO is still unknown. Herein, we sought to assess whether Ach stimulates NO production in a Ca -dependent manner in hCMEC/D3 cells, a widespread model of human brain microvascular endothelial cells.

Stim and Orai mediate constitutive Ca entry and control endoplasmic reticulum Ca refilling in primary cultures of colorectal carcinoma cells.

Store-operated Ca entry (SOCE) provides a major Ca entry route in cancer cells. SOCE is mediated by the assembly of Stim and Orai proteins at endoplasmic reticulum (ER)-plasma membrane junctions upon depletion of the ER Ca store. Additionally, Stim and Orai proteins underpin constitutive Ca entry in a growing number of cancer cell types due to the partial depletion of their ER Ca reservoir.