OBJECTIVE: To study hesperetin-induced vasorelaxation after depolarizing contraction in human umbilical veins (HUVs) to elucidate the role of L-type Ca²⁺ channel (LTCC) and related signaling pathway. METHODS: Isometric tension recording was performed in HUV rings pre-contracted with K⁺. Hesperetin relaxing mechanism was investigated using a LTCC opener (BayK8644) and blockers of cyclic nucleotides and phosphodiesterases (PDEs). Whole-cell patch-clamping in A7r5 cells, a rat vascular smooth muscle cell line, was performed to study the effect of hesperetin on LTCC current. RESULTS: After depolarizing precontraction, hesperetin induced HUV relaxation concentration-dependently and endothelium-independently; 1 mmol/L hesperetin reduced denuded HUV ring tension by 68.7% ± 4.3% compared to matching vehicle, osmolality, and time controls (P<0.0001). Importantly, hesperetin competitively inhibited BayK8644-induced contraction, shifting the half maximal effective concentration of BayK8644 response from 1.08 nmol/L [95% confidence interval (CI) 0.49-2.40] in vehicle control to 11.30 nmol/L (95% CI 5.45-23.41) in hesperetin (P=0.0001). Moreover, hesperetin elicited further vasorelaxation in denuded HUV rings pretreated with inhibitors of soluble guanylyl cyclase, adenylyl cyclase, PDE3, PDE4, and PDE5 (P<0.01), while rings pretreated with PDE1 inhibitors could not be relaxed by hesperetin (P>0.05). However, simultaneously applying inhibitors of soluble guanylyl cyclase and adenylyl cyclase could not inhibit hesperetin's effect (P>0.05). In whole-cell patch-clamping, hesperetin rapidly decreased LTCC current in A7r5 cells to 66.7% ± 5.8% (P=0.0104). CONCLUSIONS Hesperetin diminishes depolarizing contraction of human vascular smooth muscle through inhibition of LTCC, and not cyclic nucleotides nor PDEs. Our evidence supports direct LTCC interaction and provides additional basis for the use of hesperetin and its precursor hesperidin as vasodilators and may lead to future vasodilator drug development as a treatment alternative for cardiovascular diseases.
Hesperidin/pharmacology* ; Humans ; Calcium Channels, L-Type/metabolism* ; Umbilical Veins/physiology* ; Muscle Contraction/drug effects* ; Animals ; Rats ; Calcium Channel Blockers/pharmacology* ; Vasodilation/drug effects* ; Muscle Relaxation/drug effects*

OBJECTIVE: To investigate the effect of chrysophanol, a phytochemical derived from Radix et Rhizoma Rhei on HepG2 liver cancer cells. METHODS: HepG2 cell line was treated with different concentrations chrysophanol (0-100 μmol/L) for 24 h. The cell counting kit 8 assay was employed to assess cell viability. Intracellular calcium levels were examined using Fluo-4 AM and Mag-fluo-4 AM staining, followed by flow cytometry analysis. Mitochondrial membrane potential was measured with JC-1 assay kit. Additionally, the expressions of key proteins such as p-JNK, Bax, cytochrome c (Cyt C), cleaved caspase-3 (cCaspase-3), and caspase-8 were analyzed by Western blot. The inhibitory effects of chrysophanol on the invasion of cells were determined using a Transwell assay. Analysis of invasiveness was conducted by wound healing assay. RESULTS: Chrysophanol significantly reduced the proliferation of HepG2 liver cancer cells by affecting intracellular calcium distribution, diminishing mitochondrial membrane potential, and enhancing the expressions of p-JNK, Bax, Cyt C, cCaspase-3, and caspase-8 in the groups treated with 75 or 100 μmol/L chrysophanol compared to the control group (P<0.05). Additionally, 75 and 100 μmol/L chrysophanol exhibited inhibitory effects on cell migration and wound healing. CONCLUSION Chrysophanol demonstrates potential against HepG2 liver cancer cells, suggesting its potential use as a therapeutic agent for liver cancer treatment.
Humans ; Calcium/metabolism* ; Hep G2 Cells ; Liver Neoplasms/metabolism* ; Neoplasm Invasiveness ; Membrane Potential, Mitochondrial/drug effects* ; Anthraquinones/pharmacology* ; Cell Proliferation/drug effects* ; Cell Death/drug effects* ; Apoptosis/drug effects* ; Cell Movement/drug effects* ; Cell Survival/drug effects*

OBJECTIVE: To explore the functional roles and underlying mechanisms of neferine in the context of angiotensin II (Ang II)-induced hypertension and vascular dysfunction. METHODS: Male mice were infused with Ang II to induce hypertension and randomly divided into treatment groups receiving neferine or a control vehicle based on baseline blood pressure using a random number table method. The hypertensive mouse model was constructed by infusing Ang II via a micro-osmotic pump (500 ng/kg per minute), and neferine (0.1, 1, or 10 mg/kg), valsartan (10 mg/kg), or double distilled water was administered intragastrically once daily for 6 weeks. A non-invasive blood pressure system, ultrasound, and hematoxylin and eosin staining were performed to assess blood pressure and vascular changes. RNA sequencing and network pharmacology were employed to identify differentially expressed transcripts (DETs) and pathways. Vascular ring tension assay was used to test vascular function. A7R5 cells were incubated with neferine for 24 h and then treated with Ang II to record the real-time Ca²⁺ concentration by confocal microscope. Immunohistochemistry (IHC) and Western blot were used to evaluate vasorelaxation, calcium, and the extracellular signal-regulated kinase (ERK)1/2 pathway. RESULTS: Neferine treatment effectively mitigated the elevation in blood pressure, pulse wave velocity, aortic thickening in the abdominal aorta of Ang II-infused mice (P<0.05). RNA sequencing and network pharmacology analysis identified 355 DETs that were significantly reversed by neferine treatment, along with 25 potential target genes, which were further enriched in multiple pathways and biological processes, such as ERK1 and ERK2 cascade regulation, calcium pathway, and vascular smooth muscle contraction. Further investigation revealed that neferine treatment enhanced vasorelaxation and reduced Ca²⁺-dependent contraction of abdominal aortic rings, independent of endothelium function (P<0.05). The underlying mechanisms were mediated, at least in part, via suppression of receptor-operated channels, store-operated channels, or voltage-operated calcium channels. Neferine pre-treatment demonstrated a reduction in intracellular Ca²⁺ release in Ang II stimulated A7R5 cells. IHC staining and Western blot confirmed that neferine treatment effectively attenuated the upregulation of p-ERK1/2 both in vivo and in vitro, which was similar with treatment of ERK1/2 inhibitor PD98059 (P<0.05). CONCLUSIONS Neferine remarkably alleviates Ang II-induced elevation of blood pressure, vascular dysfunction, and pathological changes in the abdominal aorta. This beneficial effect is mediated by the modulation of multiple pathways, including calcium and ERK1/2 pathways.
Animals ; Angiotensin II ; Male ; Benzylisoquinolines/therapeutic use* ; Network Pharmacology ; Blood Pressure/drug effects* ; Sequence Analysis, RNA ; Mice ; Hypertension/chemically induced* ; Mice, Inbred C57BL ; Calcium/metabolism*

OBJECTIVE: To explore the mechanism of crocin, a major active component of Crocus sativus (Zanghonghua), in regulating amyloid beta (Aβ) generation, endoplasmic reticulum (ER) stress, and autophagy in neuronal cells, with potential therapeutic applications in Alzheimer's disease (AD). METHODS: Mouse neuroblastoma Neuron2a (N2a) cells stably transfected with the human amyloid precursor protein (APP) Swedish mutant was used as a cellular model for AD (N2a/APP). Control cells were vector transfected (N2a/vector). The effects of 3 different doses of crocin on reactive oxygen species (ROS) generation, cytosolic calcium, and apoptosis were evaluated by flow cytometry. Aβ levels were determined by enzyme-linked immunosorbent assay. APP processing and ER stress proteins expressions were determined by Western blot. Autophagosome formation was evaluated by autophagy detection kit and confocal microscope. RESULTS: Crocin inhibited APP expression in N2a/APP cells and promoted α-cleavage of APP processing, while modestly reduced beta-secretase 1 (BACE1) and presenilin 1 (PS1, P<0.05 or P<0.01). ER stress markers, including the binding immunoglobulin protein/78-kD glucose-regulated protein (Bip/GRP78) and C/EBP homologous protein (CHOP), were elevated in N2a/APP cells compared to N2a/vector cells (P<0.05). Crocin could effectively reduce the levels of ER stress (P<0.05 or P<0.01). In addition, crocin enhanced autophagy by promoting formation of autophagosome (P<0.05 or P<0.01). CONCLUSION Crocin significantly inhibited Aβ generation by promoting α-cleavage of APP processing, inhibiting ER stress-associated unfolded protein response, and regulating autophagy.
Endoplasmic Reticulum Stress/drug effects* ; Autophagy/drug effects* ; Animals ; Endoplasmic Reticulum Chaperone BiP ; Mice ; Amyloid beta-Peptides/metabolism* ; Amyloid beta-Protein Precursor/metabolism* ; Carotenoids/pharmacology* ; Humans ; Cell Line, Tumor ; Reactive Oxygen Species/metabolism* ; Apoptosis/drug effects* ; Calcium/metabolism*

Donors with a serum sodium concentration of >155 mmol/L are extended criteria donors for liver transplantation (LT). Elevated serum sodium of donors leads to an increased incidence of hepatic dysfunction in the early postoperative period of LT; however, the exact mechanism has not been reported. We constructed a Lewis rat model of 70% hepatic parenchymal area subjected to ischemia-reperfusion (I/R) with hypernatremia and a BRL-3A cell model of hypoxia-reoxygenation (H/R) with high-sodium (HS) culture medium precondition. To determine the degree of injury, biochemical analysis, histological analysis, and oxidative stress and apoptosis detection were performed. We applied specific inhibitors of the epithelial sodium channel (ENaC) and Na⁺/Ca²⁺ exchanger (NCX) in vivo and in vitro to verify their roles in injury. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) levels and the area of hepatic necrosis were significantly elevated in the HS+I/R group. Increased reactive oxygen species (ROS) production, myeloperoxidase (MPO)‍-positive cells, and aggravated cellular apoptosis were detected in the HS+I/R group. The HS+H/R group of BRL-3A cells showed significantly increased cellular apoptosis and ROS production compared to the H/R group. The application of amiloride (Amil), a specific inhibitor of ENaC, reduced ischemia-reperfusion injury (IRI) aggravated by HS both in vivo and in vitro, as evidenced by decreased serum transaminases, inflammatory cytokines, apoptosis, and oxidative stress. SN-6, a specific inhibitor of NCX, had a similar effect to Amil. In summary, hypernatremia aggravates hepatic IRI, which can be attenuated by pharmacological inhibition of ENaC or NCX.
Animals ; Reperfusion Injury/drug therapy* ; Hypernatremia/complications* ; Rats ; Liver/metabolism* ; Rats, Inbred Lew ; Male ; Apoptosis ; Sodium-Calcium Exchanger/antagonists & inhibitors* ; Reactive Oxygen Species/metabolism* ; Oxidative Stress ; Epithelial Sodium Channel Blockers/pharmacology* ; Epithelial Sodium Channels ; Cell Line ; Liver Transplantation

OBJECTIVES: To investigate the role of the calcium/calmodulin (CaM)-mediated activation of calcineurin (CN)-nuclear factor of activated T cells (NFAT) signaling pathway in mediating the regulatory effect of hyperforin (HY) on stress-induced depression-like disorder (DP) in mice. METHODS: C57BL/6J mice were randomly divided into control group, DP model group, and hyperforin treatment group (n=15). Behavioral changes of the mice were assessed using open field test (OFT), sucrose preference test (SPT), tail suspension test (TST), light/dark box test (LDB), and novel object suppression test (NSFT). Immunohistochemistry was used to detect tyrosine hydroxylase (TH) expression in the CA1 region of the hippocampus, and serum serotonin (5-HT) and norepinephrine (NA) levels were detected with ELISA. Western blotting was used to analyze the expressions of TNF-α, IL-1β, IL-2, and CN-NFAT pathway proteins. In cultured BV-2 microglial cells with lipopolysaccharide (LPS) stimulation, the effects of hyperforin and CN inhibitor (CNIS) on expressions of ionized calcium-binding adapter molecule 1 (IBA-1), 5-HT, NA, inflammatory cytokines and CN-NFAT pathway proteins were examined using immunofluorescence assay, ELISA or Western blotting. RESULTS: Compared with the control mice, the mice in DP group showed significantly reduced activity in OFT, decreased sucrose consumption in SPT, reduced shuttle crossing in LDB, and lowered food intake in NSFT with significantly increased immobility in TST. The mice with DP showed significantly decreased TH-positive neurons, lowered 5-HT and NA levels, and increased expressions of TNF-α, IL-1β, IL-2 and CaM-CN-NFAT pathway proteins. In cultured BV-2 cells, LPS stimulation strongly increased cellular IBA-1 expression, decreased the levels of neurotransmitters (5-HT and NA), and increased the levels of inflammatory cytokines and CN-NFAT signaling, and these changes were effectively reversed by treatment with hyperforin or CNIS. CONCLUSIONS Hyperforin improves stress-induced depression-like behaviors in mice and activated BV-2 cells by targeting the CN-NFAT signaling pathway.
Animals ; Mice, Inbred C57BL ; Mice ; Microglia/drug effects* ; Depression/etiology* ; Perylene/pharmacology* ; Calcineurin/metabolism* ; NFATC Transcription Factors/metabolism* ; Calcium Signaling/drug effects* ; Stress, Psychological ; Phloroglucinol/pharmacology* ; Signal Transduction ; Male ; Behavior, Animal/drug effects* ; Terpenes

OBJECTIVES: To investigate the effects of quercetin on cuproptosis and L-type calcium currents in the myocardium of diabetic rats. METHODS: Forty SD rats were randomized into control group and diabetic model groups. The rat models of diabetes mellitus (DM) induced by high-fat and high-sugar diet combined with streptozotocin (STZ) injection were further divided into DM model group, quercetin treatment group, and empagliflozin treatment group (n=10). Blood glucose and body weight were measured every other week, and cardiac function of the rats was evaluated using echocardiography. HE staining, Sirius red staining, and wheat germ agglutinin (WGA) analysis were used to observe the changes in myocardial histomorphology, and serum copper levels and myocardial FDX1 expression were detected. In cultured rat cardiomyocyte H9c2 cells with high-glucose exposure, the effects of quercetin and elesclomol, alone or in combination, on intracellular CK-MB and LDH levels and FDX1 expression were assessed, and the changes in L-type calcium currents were analyzed using patch-clamp technique. RESULTS: The diabetic rats exhibited elevated blood glucose, reduced body weight, impaired left ventricular function, increased serum copper levels and myocardial FDX1 expression, decreased L-type calcium currents, and prolonged action potential duration. Quercetin and empagliflozin treatment significantly lowered blood glucose, improved body weight, and restored cardiac function of the diabetic rats, and compared with empagliflozin, quercetin more effectively reduced serum copper levels, downregulated FDX1 expression, and enhanced myocardial L-type calcium currents in diabetic rats. In H9c2 cells, high glucose exposure significantly increased myocardial expressions of FDX1, CK-MB and LDH, which were effectively lowered by quercetin treatment; Elesclomol further elevated FDX1, CK-MB and LDH levels in the exposed cells, and these changes were not significantly affected by the application of quercetin. CONCLUSIONS Quercetin ameliorates myocardial injury in diabetic rats possibly by suppressing myocardial cuproptosis signaling and restoring L-type calcium channel activity.
Animals ; Quercetin/pharmacology* ; Calcium Channels, L-Type/metabolism* ; Diabetes Mellitus, Experimental/metabolism* ; Rats, Sprague-Dawley ; Rats ; Myocytes, Cardiac/drug effects* ; Myocardium/pathology* ; Male

OBJECTIVES: To investigate the changes in blood levels of calcium and bone metabolism biochemical markers in patients with primary osteoporosis receiving treatment with denosumab. METHODS: Seventy-three patients with primary osteoporosis treated in our Department between December, 2021 and December 2023 were enrolled. All the patients were treated with calcium supplements, vitamin D and calcitriol in addition to regular denosumab treatment every 6 months. Blood calcium, parathyroid hormone (PTH), osteocalcin (OC), type I procollagen amino-terminal propeptide (PINP), and type I collagen carboxy-terminal telopeptide β special sequence (β‑CTX) data before and at 3, 6, 9, and 12 months after the first treatment were collected from each patient. RESULTS: Three months after the first denosumab treatment, the bone turnover markers (BTMs) OC, PINP, and β-CTX were significantly decreased compared to their baseline levels by 39.5% (P<0.001), 56.2% (P<0.001), and 81.8% (P<0.001), respectively. At 6, 9, and 12 months of treatment, OC, PINP, and β-CTX remained significantly lower than their baseline levels (P<0.001). Blood calcium level was decreased (P<0.05) and PTH level increased (P<0.05) significantly in these patients at months of denosumab treatment, but their levels were comparable to the baseline levels at 6, 9, and 12 months of the treatment (P>0.05). CONCLUSIONS Denosumab can suppress BTMs and has a good therapeutic effect in patients with primary osteoporosis, but reduction of blood calcium and elevation of PTH levels can occur during the first 3 months in spite of calcium supplementation. Blood calcium and PTH levels can recover the baseline levels as the treatment extended, suggesting the importance of monitoring blood calcium and PTH levels during denosumab treatment.
Humans ; Denosumab/therapeutic use* ; Calcium/blood* ; Parathyroid Hormone/blood* ; Biomarkers/blood* ; Osteoporosis/blood* ; Osteocalcin/blood* ; Procollagen/blood* ; Female ; Collagen Type I/blood* ; Peptide Fragments/blood* ; Bone Density Conservation Agents/therapeutic use* ; Bone and Bones/metabolism* ; Male ; Middle Aged ; Vitamin D ; Peptides/blood* ; Aged

OBJECTIVES: To explore the toxic mechanism of Clostridium perfringens Beta1 toxin mediated by P2X7 receptor-induced calcium dyshomeostasis. METHODS: Ten-day-old BALB/c mice were randomly divided into control group, recombinant Beta1 toxin (rCPB1) group, PD151746 group, and PD151746+rCPB1 group, and all the treatment agents were administered by gavage. The changes in expressions of inflammatory factors in the jejunum of the mice were detected using antibody chip technology to explore the regulatory role of calcium dyshomeostasis in Beta1 toxin-induced inflammatory injury level. In the cell experiment, THP-1 cells were transfected with a si-RNA targeting P2X7 receptor and treated with rCPB1, and the changes in cell survival rate, levels of Ca²⁺, ROS and ATP, and expressions of pyroptosis and ferroptosis markers were determined. RESULTS: Oral administration of rCPB1 significantly increased the levels of inflammatory cytokines in the jejunal tissue of the neonatal mice, but their levels were significantly decreased after treatment with PD151746. In THP-1 cells, rCPB1 treatment significantly decreased cell survival and increased the levels of Ca²⁺, ROS, ATP and the expressions of pyroptosis and ferroptosis markers, and these changes were obviously attenuated by P2X7 receptor knockdown. CONCLUSIONS P2X7 receptor-mediated functional pore formation by Beta1 toxin can further lead to calcium dyshomeostasis, thereby triggering excessive accumulation of ROS to subsequently induce the co-occurrence of pyroptosis and ferroptosis.
Animals ; Pyroptosis/drug effects* ; Receptors, Purinergic P2X7/metabolism* ; Mice ; Mice, Inbred BALB C ; Ferroptosis/drug effects* ; Humans ; Calcium/metabolism* ; Macrophages/drug effects* ; Bacterial Toxins/toxicity*

Stromal interaction molecules (STIM)s are Ca²⁺ sensors in internal Ca²⁺ stores of the endoplasmic reticulum. They activate the store-operated Ca²⁺ channels, which are the main source of Ca²⁺ entry in non-excitable cells. Moreover, STIM proteins interact with other Ca²⁺ channel subunits and active transporters, making STIMs an important intermediate molecule in orchestrating a wide variety of Ca²⁺ influxes into excitable cells. Nevertheless, little is known about the role of STIM proteins in brain functioning. Being involved in many signaling pathways, STIMs replenish internal Ca²⁺ stores in neurons and mediate synaptic transmission and neuronal excitability. Ca²⁺ dyshomeostasis is a signature of many pathological conditions of the brain, including neurodegenerative diseases, injuries, stroke, and epilepsy. STIMs play a role in these disturbances not only by supporting abnormal store-operated Ca²⁺ entry but also by regulating Ca²⁺ influx through other channels. Here, we review the present knowledge of STIMs in neurons and their involvement in brain pathology.
Neurons/metabolism* ; Animals ; Humans ; Calcium/metabolism* ; Stromal Interaction Molecules/metabolism* ; Calcium Signaling/physiology* ; Calcium Channels/metabolism* ; Brain/metabolism*