Search Results (122)

Road traffic surveys require sensing systems that can be deployed rapidly without modifying the road surface or requiring a permanent power connection. This paper presents the design, embedded implementation, and evaluation of a low-power roadside magnetic sensor that performs vehicle-event detection and classification directly at the edge. The sensing node integrates two RM3100 three-axis magnetometers (PNI Sensor, Santa Rosa, CA, USA) with an NXP MK22FN512VLH12 microcontroller (NXP Semiconductors N.V., Eindhoven, The Netherlands) based on a 120 MHz Arm Cortex-M4F core with 512 kB Flash and 128 kB SRAM. Magnetic-field data are acquired at 250 Hz and processed locally using baseline removal, low-pass filtering, signal-energy calculation, and peak-based event detection. Detected magnetic signatures are classified using an integer-quantised one-dimensional convolutional neural network implemented directly on the microcontroller. The model processes four synchronised 512-sample channels representing the three magnetic-field axes and their combined signal energy. Model development was supported by approximately 50,000 annotated events obtained from 36 h of real-world traffic measurements at eight locations. The selected model achieved an overall classification accuracy of 91.1% for the considered operational categories. The implemented network requires 288,128 multiply–accumulate operations per inference, while its quantised weights and biases occupy approximately 23 kB of Flash memory. Complete three-axis event signatures are stored locally for subsequent verification, whereas only the timestamp and predicted vehicle category are transmitted through the wireless interface. Based on the capacity of the applied LiFePO₄ battery and the estimated consumption of the implemented hardware, the expected autonomous operating period is approximately 41 days. The results demonstrate the feasibility of integrating magnetic sensing, embedded signal processing, and Edge AI on a conventional resource-constrained Cortex-M4 platform for non-invasive road traffic monitoring. Full article

Aims: Globally, cardiovascular disorders represent the foremost contributor to mortality, and elevated arterial pressure constitutes one of their principal risk determinants. Despite the availability of various treatments, optimal blood pressure control is rarely achieved. The present work was undertaken to assess the antihypertensive and vasorelaxant properties of benzaldehyde, a naturally occurring aromatic aldehyde whose role in the regulation of arterial pressure has, to our knowledge, not yet been documented. Materials and Methods: Antihypertensive activity was evaluated in normotensive Wistar rats and in animals rendered hypertensive by chronic administration of Nω-nitro-L-arginine methyl ester (L-NAME). Benzaldehyde was administered orally at doses of 20 and 40 mg/kg under both acute (6 h) and subacute (7-day) treatment protocols. Arterial pressure was recorded non-invasively by means of a tail-cuff plethysmography system. Vasorelaxant activity was examined in vitro using isolated rat aortic rings precontracted with either Epinephrine (EP, 10 μM) or potassium chloride (KCl, 80 mM). Endothelium-dependent and endothelium-independent components were dissected by pre-incubating the rings with selective pharmacological inhibitors. Additionally, the effects of benzaldehyde on both phasic and tonic contractions induced by extracellular Ca²⁺ were assessed in EP-precontracted rings in Ca²⁺-free Krebs solution. Key Findings: In hypertensive animals, benzaldehyde produced a dose-related decrease in both systolic and diastolic arterial pressure. It induced concentration-dependent vasorelaxation in both endothelium-intact and -denuded aortic rings. Relaxation was also observed in KCl-precontracted rings. Vasorelaxant responses were significantly attenuated by Indomethacin, Nifedipine, and 2-Aminoethoxydiphenyl borinate (2-APB). Significance: These findings demonstrate that benzaldehyde lowers blood pressure through both endothelium-dependent and -independent mechanisms. These include activation of the prostacyclin (PGI₂)/cAMP pathway, inhibition of L-type calcium channels, and blockade of store-operated calcium channels (SOCCs). Full article

Store-operated calcium entry (SOCE), mediated by the endoplasmic reticulum (ER) Ca²⁺ sensors stromal interaction molecule (STIM) proteins and the plasma membrane (PM) Orai channels, is essential for calcium signaling and a wide range of physiological processes. Precise regulation of SOCE is critical for maintaining tissue homeostasis, whereas its dysregulation contributes to diverse pathological conditions, particularly organ fibrosis. In this review, we outline the molecular basis of SOCE and discuss how its dysregulation is implicated in human disease. We further emphasize the pivotal role of SOCE in driving fibrotic progression across major organ systems. Finally, we summarize current therapeutic strategies targeting SOCE and highlight their potential for the treatment of fibrosis. Full article

Store-operated Calcium (Ca²⁺) entry (SOCE), mediated by stromal interaction molecule 1 (STIM1) and Orai1, is a central pathway controlling intracellular Ca²⁺ homeostasis. Gain-of-function (GoF) mutations in STIM1 cause a spectrum of clinically overlapping disorders historically classified as Stormorken Syndrome (STK), tubular aggregate myopathy (TAM), and York Platelet Syndrome (YPS). However, increasing evidence indicates that these entities could represent a shared disease spectrum rather than distinct conditions. At the molecular level, STIM1 activation is governed by a series of autoinhibitory checkpoints that maintain the protein in a tightly controlled resting state. GoF mutations disrupt these regulatory constraints, leading to dysregulated SOCE activity that is frequently, but not uniformly, associated with constitutive channel activation depending on the specific mutation and cellular context. While many disease-associated variants localize to the EF hand, a highly conserved helix–loop–helix Ca²⁺ binding motif, and the CC1 (coiled-coil 1) domain involved in molecular regulation of STIM1 activation, an increasing number of mutations in the C-terminal region further expands the mechanistic and clinical spectrum. In this review, we summarize current concepts of molecular STIM1 activation and discuss how distinct mutations perturb specific regulatory elements of the protein. By systematically integrating published case reports into a comprehensive overview, including a mutation–phenotype correlation table, we highlight the remarkable variability in and incomplete penetrance of clinical manifestations. Full article

Latrophilin 1 (LPHN1/ADGRL1), an adhesion G-protein-coupled receptor (GPCR), is the principal receptor for α-latrotoxin (αLTX), a toxin that triggers massive neurotransmitter release. However, its endogenous signaling mechanism remains elusive. Here, we dissect the LPHN1 signaling pathway at the vertebrate neuromuscular junction, using the pore-deficient αLTX mutant LTX^N4C as a selective agonist. Combining electrophysiological recordings from LPHN1 knockout mice with pharmacological inhibitors, calcium imaging, and biochemical assays, we delineate the cascade from receptor activation to spontaneous quantal acetylcholine release. We demonstrate that LPHN1 is specifically localized to the presynaptic membrane and mediates LTX^N4C-evoked release. Upon activation, LPHN1 engages the G_αq–phospholipase C pathway to generate inositol 1,4,5-trisphosphate (IP₃), triggering Ca²⁺ release from intracellular stores via IP₃ receptors. This store depletion activates store-operated Ca²⁺ entry (SOCE), providing sustained Ca²⁺ required for LTX^N4C-induced burst-like exocytosis. We uncover distinct roles for Ca_V2.1 and Ca_V1 channels in initiating and sustaining this response. These findings establish LPHN1 as a GPCR that harnesses intracellular stores and SOCE to drive spontaneous neurotransmission, revealing a novel signaling paradigm for adhesion GPCRs in presynaptic function. Full article

Arachidonic acid (AA) is an emerging regulator of fibroblast activity in pulmonary fibrosis; however, the underlying intracellular mechanisms remain unclear. This study investigated the effects of AA on the free intracellular calcium concentration ([Ca²⁺]_i), nitric oxide (NO), and reactive oxygen species (ROS) in human WI-38 lung fibroblasts. Using fluorescent imaging and pharmacological tools, we demonstrate that AA evokes a robust, concentration-dependent increase in [Ca²⁺]_i. This response is initiated by G protein-coupled receptor 40 (GPR40), which leads to endoplasmic reticulum Ca²⁺ release through inositol 1,4,5-trisphosphate receptors (IP₃Rs) and lysosomal Ca²⁺ mobilisation through two-pore channels (TPCs). Sustained Ca²⁺ elevation is primarily mediated by influx through transient receptor potential vanilloid 4 (TRPV4) channels, with a minor contribution from store-operated Ca²⁺ entry. The AA-induced Ca²⁺ signal stimulates endothelial NO synthase-dependent NO production, which in turn triggers ROS generation, revealing a tightly coupled Ca²⁺–NO–ROS signalling network. Our findings identify AA as a potent modulator of Ca²⁺ and redox signalling in lung fibroblasts, and highlight GPR40, TRPV4, IP₃Rs and lysosomal TPCs as potential therapeutic targets for intervening in pulmonary fibrosis. Full article

Store-operated Ca²⁺ entry (SOCE) is a key regulator of cytosolic Ca²⁺ (Ca²⁺_cyt). Presynaptic SOCE can be activated by ligands like α-latrotoxin, which acts through the presynaptic G-protein-coupled receptor latrophilin-1 (LPHN1), inducing Ca²⁺ influx and neurotransmitter release. To understand how SOCE-associated proteins contribute to LPHN1 signaling in neurons, we used mouse neuroblastoma NB2a cells as a genetically tractable neuronal model. The cells were stably transfected with exogenous LPHN1 or its non-signaling mutant and stimulated with the non-pore-forming α-latrotoxin mutant LTX^N4C, a known trigger of neurotransmitter release. LPHN1 expression increased the proportion of neuron-like cells and upregulated the voltage-gated Ca²⁺ channels Ca_v1.2 and Ca_v2.1. LPHN1 stimulation by LTX^N4C induced a small Ca²⁺ release sensitive to thapsigargin, and a strong, gradual influx of Ca²⁺, which was insensitive to thapsigargin. Single-cell imaging revealed that this influx consisted of desynchronized high-amplitude Ca²⁺ oscillations in individual cells. This response was reduced by Orai2 knockdown and completely blocked by the Ca_v2.1/2.2 inhibitor ω-conotoxin MVIIC. We conclude that LPHN1 activation by LTX^N4C primes Ca²⁺ stores and induces the opening of Ca_v2.1/2.2 channels. These channels mediate an initial Ca²⁺ influx that triggers Ca²⁺-induced Ca²⁺ release and SOCE. This mechanism, elucidated in model cells, can explain how LTX^N4C stimulates neurotransmitter release. Full article

Endometrial cancer is one of the most common malignancies of the female reproductive system, with incidence rising globally due to population ageing and life-style-related risk factors. Calcium (Ca²⁺) is a ubiquitous second messenger regulating diverse physiological processes, and its dysregulation has been increasingly implicated in carcinogenesis, including endometrial. Altered expression and function of Ca²⁺ channels, pumps, exchangers, and binding proteins disrupt the finely tuned balance of Ca²⁺ influx, efflux, and intracellular storage, leading to aberrant signalling that promotes tumour proliferation, migration, survival, and metastasis. This review summarises current knowledge on the molecular “Ca²⁺ toolkit” in the human uterus, highlighting the role of voltage-gated calcium channels (VGCCs), transient receptor potential (TRP) channels, store-operated calcium entry (SOCE) components, Na⁺/Ca²⁺ exchangers, purinergic receptors, P-type ATPases (SERCA, SPCA, PMCA), ryanodine (RyR) and inositol 1,4,5-trisphosphate (IP₃R) receptors, and mitochondrial Ca²⁺ uniporter (MCU) complexes in endometrial cancer progression. Multiple Ca²⁺-handling proteins, including CACNA1D, CACNA2D1, TRPV4, TRPV1, TRPM4, MCU, and RyR1, exhibit cancer-associated overexpression or functional changes, correlating with poor prognosis and aggressive disease features. Emerging evidence supports the therapeutic potential of targeting Ca²⁺ homeostasis using small-molecule inhibitors, ion channel modulators or gene-silencing strategies. These interventions may restore Ca²⁺ balance, induce apoptosis or autophagy, and suppress metastatic behaviour. While no clinical trials have yet explicitly focused on Ca²⁺ modulation in endometrial cancer, the diversity of dysregulated Ca²⁺ pathways offers a rich landscape for novel therapeutic strategies. Targeting key components of the Ca²⁺ signalling network holds promise for improving outcomes in endometrial cancer. Full article

STC2 (stanniocalcin 2) controls calcium (Ca²⁺) homeostasis in human platelets and other cell lines. The regulation of intracellular Ca²⁺ homeostasis is crucial for platelet activation; thus, the alteration in intracellular Ca²⁺ concentration or the mechanism involved in its regulation has been proposed to underlie some thrombotic disorders. Our previous studies evidenced that the knockdown of STC2 altered murine platelet activation; furthermore, a reduction in STC2 expression resulted in enhanced Ca²⁺ homeostasis in diabetic patients and, therefore, would contribute to the prothrombotic condition as a hallmark of diabetes mellitus type 2 (DM2). In this study, we examine a possible link between the expression of stanniocalcins (STCs) and different thrombotic events in humans. The expression of STCs was determined by Western blotting (WB); meanwhile, the analysis of protein interaction and phosphorylation was performed by completing a previous immunoprecipitation protocol (IP) of the proteins of interest. Thus, our results from patients with stroke/ictus presented a clear reduction in STC2 expression in their platelets, finding less STC2 content in the youngest thrombotic patients. Furthermore, acetyl-salicylic acid (ASA) administration reversed the decrease in the expression of STC2 in patients who did not suffer additional thrombotic episodes, as evidenced by the longitudinal analysis of up to 10 years of follow-up. Additionally, the increase in STC2 phosphorylation at the serine residues revealed increased activity of STC2 in thrombotic patients. Finally, we suggest that store-operated Ca²⁺ entry (SOCE) is over-activated in patients suffering from stroke/ictus, as revealed by the increase in the STIM1/Orai1 interaction found under resting conditions and, further, because MEG-01 cells transfected with siRNA STC2 to evoke artificial reduction in the STC2 expression presented an increased SOCE with respect to the control cells transfected with siRNA A. Conversely, the expression of the non-capacitative Ca²⁺ channels, Orai3 and TRPC6, was found to be reduced in patients with stroke. Altogether, our data allow us to conclude that STC2 represents a promising marker of stroke/ictus in thrombotic patients. Full article

Intracellular emetic signals involved in the cannabinoid CB₁ receptor inverse agonist/antagonist SR141716A were investigated. SR141716A (20 mg/kg, i.p.)-evoked vomiting occurred via both the central and peripheral mechanisms. This was accompanied by robust emesis-associated increases in the following: (i) c-fos- and phospho-glycogen synthase kinase-3α/β (p-GSK-3αβ)-expression in the shrew’s dorsal vagal complex (DVC), (ii) phospho-extracellular signal-regulated kinase1/2 (p-ERK_1/2) expression in both the DVC and jejunal enteric nervous system, and (iii) time-dependent upregulation of cAMP levels and phosphorylation of protein kinase A (PKA), protein kinase B (Akt), GSK-3α/β, ERK_1/2, and protein kinase C αβII (PKCαβII) in the brainstem. SR141716A-evoked emetic parameters were attenuated by diverse inhibitors of the following: PKA, ERK_1/2, GSK-3, phosphatidylinositol 3-kinase (PI3K)-Akt pathway, phospholipase C (PLC), PKC, Ca²⁺/calmodulin-dependent protein kinase II (CaMKII), L-type Ca²⁺ channel (LTCC), store-operated Ca²⁺ entry (SOCE), inositol trisphosphate receptor (IP3R), ryanodine receptor (RyRs), both 5-HT₃-, and D_2/3-receptor antagonists, and the transient receptor potential vanilloid 1 receptor (TRPV1R) agonist. SR141716A appears to evoke vomiting via inverse agonist activity involving emesis-associated kinases, including cAMP/PKA, ERK_1/2, PI3K/Akt/GSK-3, PLC/PKCαβII, and CaMKII, which depend upon Ca²⁺ mobilization linking extracellular Ca²⁺ entry via plasma membrane Ca²⁺ channels (LTCC, SOCE, TRIPV1R) and intracellular Ca²⁺ release via IP3Rs and RyRs. The 5-HT₃, NK₁, and D_2/3 receptors also contribute to SR141716A-mediated vomiting. Full article

Schwann cells (SCs) are central players in peripheral nerve repair, facilitating axonal regrowth, remyelination, and modulation of the regenerative microenvironment. A pivotal driver of these functions is intracellular Ca²⁺ signaling, regulated by both endogenous Ca²⁺-permeable ion channels and engineered optogenetic actuators. Recent developments in optogenetics, particularly the application of Ca²⁺-permeable channelrhodopsins such as CapChR2, have enabled precise, light-controlled activation of SCs, allowing for targeted investigation of Ca²⁺-dependent pathways in non-neuronal cells. This review synthesizes emerging evidence demonstrating that optogenetically or endogenously induced Ca²⁺ influx in SCs leads to the release of a diverse set of neurotrophic and regulatory factors. These Ca²⁺-triggered secretomes modulate SC phenotypes and surrounding neurons, orchestrating axon regeneration and myelin repair via autocrine and paracrine mechanisms. We further discuss the roles of key endogenous Ca²⁺ channels—including transient receptor potential (TRP) channels and store-operated Ca²⁺ entry (SOCE; STIM/Orai)—in orchestrating SC activation under physiological and injury-induced conditions. By integrating insights from optogenetic manipulation and intrinsic signaling biology, this review proposes a conceptual framework in which Ca²⁺-triggered SC secretomes act as structural and functional scaffolds for nerve repair. We highlight how SC-derived factors shape the regenerative niche, influence adjacent neurons and glia, and modulate repair processes in peripheral and autonomic nerves. Full article

Tubular aggregate myopathy (TAM) is an inherited skeletal muscle disease associated with progressive muscle weakness, cramps, and myalgia. Tubular aggregates (TAs) are regular arrays of highly ordered and densely packed straight-tubules observed in muscle biopsies; the extensive presence of TAs represent a key histopathological hallmark of this disease in TAM patients. TAM is caused by gain-of-function mutations in proteins that coordinate store-operated Ca²⁺ entry (SOCE): STIM1 Ca²⁺ sensor proteins in the sarcoplasmic reticulum (SR) and Ca²⁺-permeable ORAI1 channels in the surface membrane. Here, we assessed the therapeutic potential of endurance exercise in the form of voluntary wheel running (VWR) in mitigating TAs and muscle weakness in Orai1^G100S/+ (GS) mice harboring a gain-of-function mutation in the ORAI1 pore. Six months of VWR exercise significantly increased specific force production, upregulated biosynthetic and protein translation pathways, and normalized both mitochondrial protein expression and morphology in the soleus of GS mice. VWR also restored Ca²⁺ store content, reduced the incidence of TAs, and normalized pathways involving the formation of supramolecular complexes in fast twitch muscles of GS mice. In summary, sustained voluntary endurance exercise improved multiple skeletal muscle phenotypes observed in the GS mouse model of TAM. Full article

Calcium (Ca²⁺) signaling is a fundamental regulatory mechanism controlling essential processes in the endothelium, vascular smooth muscle cells (VSMCs), and the extracellular matrix (ECM), including maintaining the endothelial barrier, modulation of vascular tone, and vascular remodeling. Cytosolic free Ca²⁺ concentration is tightly regulated by a balance between Ca²⁺ mobilization mechanisms, including Ca²⁺ release from the intracellular stores in the sarcoplasmic/endoplasmic reticulum and Ca²⁺ entry via voltage-dependent, transient-receptor potential, and store-operated Ca²⁺ channels, and Ca²⁺ elimination pathways including Ca²⁺ extrusion by the plasma membrane Ca²⁺-ATPase and Na⁺/Ca²⁺ exchanger and Ca²⁺ re-uptake by the sarco(endo)plasmic reticulum Ca²⁺-ATPase and the mitochondria. Some cell membranes/organelles are multifunctional and have both Ca²⁺ mobilization and Ca²⁺ removal pathways. Also, the individual Ca²⁺ handling pathways could be integrated to function in a regenerative, capacitative, cooperative, bidirectional, or reciprocal feed-forward or feed-back manner. Disruption of these pathways causes dysregulation of the Ca²⁺ signaling dynamics and leads to pathological cardiovascular conditions such as hypertension, coronary artery disease, atherosclerosis, and vascular calcification. In the endothelium, dysregulated Ca²⁺ signaling impairs nitric oxide production, reduces vasodilatory capacity, and increases vascular permeability. In VSMCs, Ca²⁺-dependent phosphorylation of the myosin light chain and Ca²⁺ sensitization by protein kinase-C (PKC) and Rho-kinase (ROCK) increase vascular tone and could lead to increased blood pressure and hypertension. Ca²⁺ activation of matrix metalloproteinases causes collagen/elastin imbalance and promotes vascular remodeling. Ca²⁺-dependent immune cell activation, leukocyte infiltration, and cholesterol accumulation by macrophages promote foam cell formation and atherosclerotic plaque progression. Chronic increases in VSMCs Ca²⁺ promote phenotypic switching to mesenchymal cells and osteogenic transformation and thereby accelerate vascular calcification and plaque instability. Emerging therapeutic strategies targeting these Ca²⁺-dependent mechanisms, including Ca²⁺ channel blockers and PKC and ROCK inhibitors, hold promise for restoring Ca²⁺ homeostasis and mitigating vascular disease progression. Full article

Mechanogated (MG) ion channels play a crucial role in mechano-transduction and immune cell regulation, yet their impact on blood cancers, particularly acute lymphoblastic leukemia (ALL), remains poorly understood. This study investigates the pharmacological effects of GsMTx4, an MG channel inhibitor, in human ALL cells both in vitro and in vivo. Unexpectedly, we found that GsMTx4 remarkably increased basal calcium (Ca²⁺) levels in ALL cells through constitutive Ca²⁺ entry and enhanced store-operated Ca²⁺ influx upon thapsigargin stimulation. This increase in basal Ca²⁺ signaling promoted ALL cell viability and proliferation in vitro. Notably, chelating intracellular Ca²⁺ with BAPTA-AM reduces GsMTx4-mediated leukemia cell viability and proliferation. However, in vivo, GsMTx4 decreases cytosolic Ca²⁺ levels in Nalm-6 GFP⁺ cells isolated from mouse blood, effectively countering leukemia progression and significantly extending survival in NSG mice transplanted with leukemia cells (median survival: GsMTx4 vs. control, 37.5 days vs. 29 days, p = 0.0414). Our results highlight the different properties of GsMTx4 activity in in vitro and in vivo models. They also emphasize that Ca²⁺ signaling is a key vulnerability in leukemia, where its precise modulation dictates disease progression. Thus, targeting Ca²⁺ channels could offer a novel therapeutic strategy for leukemia by exploiting Ca²⁺ homeostasis. Full article

Ryanodine receptors (RyRs) are large intracellular Ca²⁺ release channels primarily found in muscle and nerve cells and also present at low levels in pancreatic islet endocrine cells. This review examines the role of RyRs in islet cell function, focusing on calcium signaling and hormone secretion, while addressing the ongoing debate regarding their significance due to their limited expression. We explore conflicting experimental results and their potential causes, synthesizing current knowledge on RyR isoforms in islet cells, particularly in beta and delta cells. The review discusses how RyR-mediated calcium-induced calcium release enhances, rather than drives, glucose-stimulated insulin secretion. We examine the phosphorylation-dependent regulation of beta-cell RyRs, the concept of “leaky ryanodine receptors”, and the roles of RyRs in endoplasmic reticulum stress, apoptosis, store-operated calcium entry, and beta-cell electrical activity. The relationship between RyR dysfunction and the development of impaired insulin secretion in diabetes is assessed, noting their limited role in human diabetes pathogenesis given the disease’s polygenic nature. We highlight the established role of RyR-mediated CICR in the mechanism of action of common type 2 diabetes treatments, such as glucagon-like peptide-1, which enhances insulin secretion. By integrating findings from electrophysiological, molecular, and clinical studies, this review provides a balanced perspective on RyRs in islet cell physiology and pathology, emphasizing their significance in both normal insulin secretion and current diabetes therapies. Full article