Search Results (1,062)

L-type Ca²⁺ channels, particularly Ca_V1.2, play a crucial role in cardiac excitation-contraction coupling and are known to exhibit mechanosensitivity. However, the mechanisms regulating their response to mechanical stress remain poorly understood. To investigate the mechanosensitivity and nitric oxide (NO)-dependent regulation of L-type Ca²⁺ channels in rat ventricular cardiomyocytes, we used RNA sequencing to assess isoform expression and whole-cell patch-clamp recordings to measure L-type Ca²⁺ current (I_Ca,L) under controlled mechanical and pharmacological conditions. RNA sequencing revealed predominant expression of Ca_V1.2 (TPM: 0.1170 ± 0.0075) compared to Ca_V1.3 (0.0021 ± 0.0002) and Ca_V1.1 (0.0002 ± 0.0002). Local axial stretch (6–10 μm) consistently reduced I_Ca,L in proportion to stretch magnitude. The NO donor SNAP (200 μM) had variable effects on basal I_Ca,L in unstretched cells (stimulatory, inhibitory, or biphasic) but consistently restored stretch-reduced I_Ca,L to control levels. Ascorbic acid (10 μM), which reduces S-nitrosylation, increased basal I_Ca,L and partially restored the reduction caused by stretch, implicating S-nitrosylation in channel regulation. The sGC inhibitor ODQ (5 μM) decreased I_Ca,L in both stretched and unstretched cells, indicating involvement of the NO–cGMP pathway. Mechanical stress modulates L-type Ca²⁺ channels through a complex interplay between S-nitrosylation and NO–cGMP signaling, with S-nitrosylation playing a predominant role in stretch-induced effects. This mechanism may represent a key component of cardiac mechanotransduction and could be relevant for therapeutic targeting in cardiac pathologies involving mechanically induced dysfunction. Full article

Koshu wine, produced from the indigenous Japanese grape Vitis vinifera L. cv. Koshu exhibits a lower pH than other white wines, hindering malolactic fermentation (MLF) by lactic acid bacteria (LAB). Here, we aimed to isolate LAB strains capable of performing MLF under these challenging conditions to improve wine quality. Sixty-four Oenococcus oeni and one Lactobacillus hilgardii strain were isolated from Koshu grapes and wines that had undergone spontaneous MLF. MLF activity was assessed under varying pH, SO₂, and ethanol conditions in modified basal medium (BM) and Koshu model wine media. Expression of stress-related genes was analyzed using real-time PCR. Carbon source utilization was evaluated via API 50CH assays. All isolates degraded malic acid and produced lactic acid at 15 °C and pH 3.2 in BM without reducing sugars. Seven strains, all identified as O. oeni, demonstrated MLF activity at pH 3.0 in modified BM lacking added reducing sugars or tomato juice. Six wine-derived strains tolerated up to 12% ethanol, whereas the grape-derived strain was inhibited at 10%. In a synthetic Koshu wine model (13% ethanol, pH 3.0), wine-derived isolates exhibited higher MLF activity than commercial starter strains. In high-performing strains, mleA was upregulated, and most isolates preferred fructose, arabinose, and ribose over glucose. These findings suggest that indigenous O. oeni strains from Koshu wine possess unique stress tolerance and metabolic traits, making them promising candidates for region-specific MLF starter cultures that could enhance Koshu wine quality and terroir expression. Full article

Low solar radiation, caused by climate change or dense planting patterns, now limits wheat production. Although wheat breeding has increased lodging resistance and yield potential through the introduction of dwarfing genes, it still reduces wheat yields. Few studies have been conducted to clarify the lodging sensitivity to shading of different-era wheat cultivars in China’s Huang-Huai-Hai region, as well as the characteristics of lodging resistance as affected by paclobutrazol under shading stress. To address this gap, the experiment included two wheat cultivars released in different decades, grown under shade and treated with or without paclobutrazol. The results showed that reductions in filling degree and lignin content, together with increases in length of the basal internode and gravity center height, markedly reduced the section modulus and breaking strength of shaded wheat culms. These changes impaired lodging resistance and raised lodging risk. However, paclobutrazol application effectively reduced lodging incidence and increased wheat yield under shading stress. Furthermore, these responses were more pronounced in the old cultivar (YZM) than in the modern cultivar (S28). This indicates that the culm mechanical parameters of the old cultivar were more shade-sensitive than those of the modern cultivar. Moreover, shading downregulated the relative expression levels of key genes associated with lignin biosynthesis to decrease the activities of key enzymes, thereby inhibiting the biosynthesis and deposition of lignin in culms to increase the risk of wheat lodging. Paclobutrazol application alleviated the inhibitory effects of shading on lignin biosynthesis, thereby strengthening culms and enhancing lodging resistance. These findings may provide a basis for exploring cultivation regulation methods to enhance wheat lodging resistance under overcast and low-sunshine conditions, and to offer guidance for the breeding of wheat cultivars with lodging resistance and shade tolerance. Full article

Genome instability is a hallmark of cancer, often driven by mutations and altered expression of genome maintenance factors involved in DNA replication and repair. Rap1 Interacting Factor 1 (RIF1) plays a crucial role in genome stability and is implicated in cancer pathogenesis. Cells express two RIF1 splice variants, RIF1-Long and RIF1-Short, which differ in their ability to protect cells from DNA replication stress. Here, we investigate differential expression and splicing of RIF1 in cancer cell lines following replication stress and in patients using matched normal and tumour data from The Cancer Genome Atlas (TCGA). Overall RIF1 expression is altered in several cancer types, with increased transcript levels in colon and lung cancers. RIF1 also exhibits distinct splicing patterns, particularly in specific breast cancer subtypes. In Luminal A (LumA), Luminal B (LumB), and HER2-enriched breast cancers (HER2E), RIF1 Exon 31 tends to be excluded, favouring RIF1-Short expression and correlating with poorer clinical outcomes. These breast cancer subtypes also tend to exclude other short exons, suggesting length-dependent splicing dysregulation. Basal breast cancer also shows exon exclusion, but unlike other subtypes, it shows no short-exon bias. Surprisingly, however, in basal breast cancer, RIF1 Exon 31 is not consistently excluded, which may impact prognosis since RIF1-Long protects against replication stress. Full article

Background: Breast cancer (BC) is highly heterogeneous, with varying molecular characteristics, such as reliance on autophagy. Autophagy is a critical cellular degradation process that helps cells survive under stress, but its regulation can be influenced by altered microRNA (miRNA) expression. Studying miRNA changes during starvation-induced autophagy in both mammary epithelial cells and BC cells could reveal potential molecular therapy targets. Methods: Rat mammary gland healthy epithelial and cancer cells were subjected to starvation, and differences in proliferation, migration, invasion, autophagy, and expression of autophagy-associated miRNAs were determined. Afterward, we assessed the effects of miR-218-5p modulation on the aforementioned processes. Results: Starvation-induced autophagy reduced the proliferation of all cells and increased the invasive and migratory capacity of cancer cells (p ≤ 0.05). We identified a miRNA signature related to starvation, comprising twenty-seven miRNAs. One miRNA had a significantly elevated baseline expression, while another six, including miR-218-5p, had a significantly lower basal expression in cancer cells compared to healthy cells (p ≤ 0.05). However, starvation caused significant miRNA expression changes, with miR-218-5p being upregulated specifically in cancer cells (p = 0.20–0.01). Functional studies on the role of miR-218-5p show that its inhibition decreases migration and leads to autophagosome accumulation. The study of miR-218-5p molecular targets has shown that its inhibition of sorting nexin 18 (SNX18) may act as an important regulator of the starvation-induced response in cancer cells. Conclusions: The baseline expression of miRNA related to starvation and autophagy differs between rat mammary gland cancer and healthy cells. The response to starvation also varies between cancer cells and normal cells. Starvation induces BC-specific miRNA dysregulation, affecting particularly miR-218-5p, which acts via SNX18, promoting the cancer cells’ survival. Full article

The hypothalamus belongs to the central brain structure designed for the neuroendocrine regulation of many organismal functions, including the stress response, cardiovascular system, and blood pressure, and it is well known that the serotonergic hypothalamic system plays a significant role in these processes. Unfortunately, the genetic determination of serotonergic hypothalamic mechanisms has been little studied. The aim of this article is to describe the expression profile of the genes in the hypothalamic serotonergic synapses in hypertensive ISIAH rats in comparison with normotensive WAG rats in control conditions and under the influence of a single short-term restraint stress. It was found that 14 differentially expressed genes (DEGs) may provide the inter-strain differences in the serotonergic synaptic function in the hypothalamus between the hyper- and normotensive rats studied. In hypertensive rats, downregulation of Slc18a1 gene in the presynaptic serotoninergic ends and decreased expression of Cacna1s and Htr3a genes determining the postsynaptic membrane conductance may be considered as a main factors causing differences in the function of hypothalamic serotoninergic synapses in hypertensive ISIAH and normotensive WAG rats at the basal conditions. Under basal conditions, glial cell genes were not involved in the formation of inter-strain differences in serotonergic synaptic function. The analysis of transcriptional responses to restraint stress revealed key genes whose expression is involved in the regulation of serotonergic signaling, and a cascade of interrelated changes in biological processes and metabolic pathways. Stress-dependent changes in the expression of some DEGs are similar in the hypothalamus of hypertensive and normotensive rats, but the expression of a number of genes changes in a strain-specific manner. The results suggest that in hypothalamic glial cells of both strains, restraint stress induces changes in the expression of DEGs associated with the synthesis of Ip3 and its receptors. Many of the identified serotonergic DEGs participate in the regulation of not only serotonergic synapses but may also be involved in the regulation of cholinergic, GABAergic, glutamatergic, and dopaminergic synapses. The results of the study provide new information on the genetic mechanisms of inter-strain differences in the functioning of the hypothalamic serotonergic system in hypertensive ISIAH and normotensive WAG rats at rest and under the influence of a single short-term restraint (emotional) stress. Full article

The objective of this study was to evaluate the effect of tyrosine on behavior and ruminal meta-taxonomic profile of Altay sheep. Twelve rams with the lowest behavioral responses to humans and twelve rams with the highest behavioral responses were sorted into calm and nervous groups, respectively. Following the 2 × 2 factorial design, the rams from each group were equally assigned two treatments of a basal diet and a diet with an extra 4 g of tyrosine for 30 d. The temperament trait, growth performance, rumen fermentation parameters, ruminal epithelium antioxidant capacity, and rumen microbial composition were measured at the end of the feeding experiment. The results showed that tyrosine treatment led to a decreased number of crosses in the arena test in nervous sheep (p < 0.05). The tyrosine treatment led to increased antioxidant markers in the rumen epithelium, such as catalase, total antioxidant capacity, and GSH content in rumen epithelial tissues (p < 0.05) in calm and nervous sheep. The total volatile fatty acids and propionic acid content in the rumen were increased by tyrosine treatment in nervous and calm sheep (p < 0.05). The rumen microbial study revealed that the dominant microbial genera were Cryptobacteroides, Prevotella, Limivicinus, Quinella, UBA1711, RUG740, Sachharofermentans, Limomorpha, Soladiphilus, Flexinia, and others in both the tyrosine treatment and temperament groups. A combined effect of treatment and temperament was seen on the abundance of two microbial genera, UBA1711 and RUG740 (p < 0.05). These findings suggest that tyrosine-treated Altay sheep would experience less stress during production, resulting in reduced oxidative stress in the rumen epithelium and improved propionic acid production in the rumen compared with that of basal-diet-treated Altay sheep. Meanwhile, the effect of the dietary tyrosine treatment on ruminal microbial diversity was lower, suggesting lesser degradation of tyrosine by ruminal microbes in Altay sheep. Full article

Caleosin/peroxygenases (CLO/PXGs) play critical functional roles during plant development, oxylipin metabolism, and the response to abiotic/biotic stressors and environmental toxins. In Oryza sativa, peroxygenase-9 (OsPXG9) catabolizes intermediates in oxylipin biosynthesis produced by lipoxygenase-9 (9-LOX) and scavenges HOOH and CuOOH by transferring oxygen to hydroxy fatty acids (HFAs) but not to the free fatty acids. The resulting epoxide derivatives of HFAs are then enzymatically or non-enzymatically hydrolyzed into the corresponding trihydroxy derivatives. Results presented here demonstrate OsPXG9′s specificity for catabolizing products of the 9-LOX (and not for the 13-LOX) pathway of oxylipin biosynthesis. Overexpression of OsPXG9 reduces ROS (reactive oxygen species) abundance and reduces drought- and salt-stress-induced apoptotic cell death. The high expression level of OsPXG9 also stimulates drought- and salt-induced but not basal expression of antioxidant enzymes/pathways in plants, thereby increasing cellular resistance to drought. These results suggest that OsPXG9 decreases ROS abundance and is essential to increase resilience in rice plants exposed to exogenous or endogenous abiotic stress. Full article

Background: The spleen is the primary reservoir of immune cells in mammals. Diverse stimuli can disrupt spleen homeostasis, resulting in spleen injury and immune dysfunction. This study employed a porcine model to assess the therapeutic potential of salvianolic acid B (SAB) against lipopolysaccharide (LPS)-induced splenic injury. Methods: Seventy-two male weanling piglets were randomly assigned to one of four groups: CON-SS, SAB-SS, CON-LPS, and SAB-LPS. The CON-SS and CON-LPS groups received a basal diet, while SAB-SS and SAB-LPS groups received a SAB-supplemented diet. After 14 d, the CON-SS and SAB-SS groups received an intraperitoneal injection of sterile saline, whereas the CON-LPS and SAB-LPS groups were injected with LPS. Blood and spleen tissues were harvested 6 h post-injection for biochemical analysis. Results: LPS induced systemic immune disorders in piglets, as evidenced by increased immune organ indices and decreased white blood cell, lymphocyte, and basophil counts in blood (p < 0.05). LPS also caused histoarchitectural disruption, cell apoptosis, oxidative stress, and inflammation in the spleen (p < 0.05). Conversely, SAB improved splenic histopathology and reduced splenic apoptosis and pro-inflammatory mediators in piglets (p < 0.05). SAB significantly mitigated peroxidation accumulation by facilitating the nuclear translocation of nuclear factor erythroid 2-related factor 2 and strengthening the antioxidant system, and inhibited nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing 3 (NLRP3) inflammasome activation (p < 0.05). Mechanistically, SAB attenuated LPS-induced splenic oxidative stress and NLRP3 inflammasome activation by restoring mitochondrial structure and function (p < 0.05). Conclusions: This research unveils that SAB alleviates LPS-induced spleen disorder by reinforcing antioxidant system and suppressing NLRP3 inflammasome, highlighting SAB’s potential as a prospective therapeutic agent for spleen disorders. Full article

This study evaluated the inhibitory activity of quercetin at sub-inhibitory concentrations on quorum-sensing (QS) molecules in vitro and the effects of dietary supplementation with quercetin (for 24 consecutive days) on enterotoxigenic Escherichia coli (ETEC)-induced inflammatory and oxidative stress responses in weaned piglets. The piglets were fed one of three diets: the basal diet (Con), ETEC challenge (K88) after the basal diet, or ETEC challenge (quercetin + K88) after the basal diet supplemented with 0.2% quercetin. In vitro experiments revealed that 5 mg/mL quercetin exhibited the strongest QS inhibitory activity and reduced pigment production by Chromobacterium violaceum ATCC12472 by 67.70%. In vivo experiments revealed that quercetin + K88 significantly increased immunoglobulin A (IgA), immunoglobulin M (IgM), and immunoglobulin G (IgG) levels in the serum, ileum mucosa, and colon mucosa; increased glutathione peroxidase (GSH-Px), catalase (CAT), and superoxide dismutase (SOD) levels in the serum, liver, and colon mucosa; and decreased cluster of differentiation 3 (CD3) and cluster of differentiation 8 (CD8)activity in the serum compared with K88 alone. Quercetin + K88 significantly alleviated pathological damage to the liver and spleen and upregulated antioxidant genes (nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1(HO-1), CAT, SOD, and glutathione s-transferase (GST)). Inducible nitric oxide synthase (iNOS) and kelch-like ech-associated protein 1 (Keap1), which cause oxidative damage to the liver and spleen, were significantly downregulated. The acetic acid content in the cecum was significantly increased, and the E. coli count and QS signal molecule autoinducer-2 (AI-2) yield were significantly reduced. In conclusion, 0.2% dietary quercetin can alleviate ETEC-induced inflammation and oxidative stress in weaned piglets. Full article

Apigenin and sodium butyrate have been reported to help alleviate oxidative stress. This study evaluated the jejunal transcriptomic responses in ducks receiving apigenin and sodium butyrate supplementation under oxidative stress. In total, 200 healthy 300-day-old female Jinyun Ma ducks (1.53 kg ± 0.15) were randomly divided into four groups, with five replicates per group. The groups were as follows: a control group (CON): ducks were fed a basal diet with sterile saline injection; a diquat-injection (DIQ) group: ducks were fed a basal diet with diquat injection; an apigenin plus diquat group (API): ducks were fed a basal diet containing apigenin (500 mg/kg) with diquat injection; and a sodium butyrate plus diquat group (SB): ducks were fed a basal diet containing sodium butyrate (500 mg/kg) with diquat injection. The injection dose of diquat is 8 mg/kg body weight. Analysis revealed that the dietary supplementation of apigenin and sodium butyrate reduced malondialdehyde (MDA) levels and increased total antioxidant capacity (T-AOC) (p < 0.05). Compared to the DIQ group, sodium butyrate supplementation during oxidative stress elevated jejunal villus height and villus height/crypt depth ratio in ducks (p < 0.05). The study identified that some candidate genes, including solute carrier family 4 member 3 (SLC4A3), ADAM metallopeptidase domain 12 (ADAM12), and B-cell lymphoma 2-associated-athanogene 3 (BAG3), were significantly upregulated, whereas claudin 23 (CLDN23) and glucose-6-phosphatase catalytic subunit 1 (G6PC1) were markedly downregulated in the API group in comparison with that in the DIQ group (p < 0.05). Collectively, our findings provide molecular evidence for the beneficial effects of apigenin and sodium butyrate against oxidative stress in the jejunum of ducks. Full article

Understanding the relationship between deformation behavior and mechanisms at elevated temperatures is of great significance for applications of high-temperature titanium alloys. This study systematically investigates the plastic deformation behavior of Ti65 alloy under both room-temperature and high-temperature conditions through in situ tensile testing, combined with slip trace analysis, crystal orientation analysis, and geometrical compatibility factor evaluation. TEM observations and molecular dynamics simulations reveal that plastic deformation is predominantly accommodated by basal and prismatic slip systems with minimal pyramidal slip contribution at room temperature. However, elevated temperatures significantly promote pyramidal <a> and <c+a> slip due to thermal activation. This transition stems from a shift in deformation mechanisms: while room-temperature deformation relies on multi-slip and grain rotation to accommodate strain, high-temperature deformation is governed by efficient slip transfer across grain boundaries enabled by enhanced geometrical compatibility. Consistent with this, thermal activation at elevated temperatures reduces the critical resolved shear stress (CRSS), preferentially activating 1/3<11–23> dislocations and thereby substantially improving plastic deformation capability. These findings provide critical insights into the temperature-dependent deformation mechanisms of Ti65 alloy, offering valuable guidance for performance optimization in high-temperature applications. Full article

Malignant peripheral nerve sheath tumors (MPNSTs) are a rare type of soft tissue sarcoma associated with poor prognoses. The standard of care for non-resectable tumors consists of surgical excision followed by radiation and chemotherapy. MPNSTs are most common in patients with neurofibromatosis type 1 but can also occur sporadically. Regardless of origin, MPNSTs most often rely on signaling pathways that increase basal oxidative stress. This provides the basis for developing therapeutics with mechanisms that can potentiate oxidative stress to selectively eradicate tumor cells at doses that are tolerable for normal cells. Artemisinin derivatives are a mainstay of malaria therapy worldwide, with a well-established safety profile. Artemisinin’s antimalarial effects are due to an endoperoxide bridge in its chemical structure that induces oxidative stress. We found that artesunate (ARS) and metabolite dihydroartemisinin (DHA) are selectively cytotoxic to MPNST cells relative to normal Schwann cells with the endoperoxide bridge required for activity. Mechanistically, DHA induced oxidative stress, lipid peroxidation, and DHA-mediated cytotoxicity could be prevented with co-administration of the antioxidant N-acetyl-cysteine. Furthermore, we found that DHA was able to selectively remove MPNST from co-culture with normal Schwann cells. These data supports the further development of artemisinins for the clinical management of MPNST. Full article

Background/Objectives: Ischemic postconditioning (IP) is a well-established intervention that mitigates this damage by activating endogenous cardioprotective pathways. However, the presence of comorbidities such as dyslipidemia can disrupt these protective mechanisms and abolish the infarct-sparing effect typically induced by IP. In this context, identifying pharmacological strategies to restore cardioprotection is of clinical relevance. This study aimed to evaluate whether N-acetylcysteine (NAC), a glutathione precursor with antioxidant properties, can restore the infarct-limiting effect of IP compromised by HFD-induced oxidative stress. Methods: Male mice were fed a control diet (CD) or HFD for 12 weeks. NAC (10 mM) was administered in drinking water for 3 weeks before ex vivo myocardial ischemia/reperfusion (I/R) injury (30 min ischemia/60 min reperfusion). In IP groups, six cycles of brief I/R were applied at the onset of reperfusion. Infarct size, ventricular function, redox status (GSH/GSSG), lipid profile, and histology were evaluated. Results: NAC improved the lipid profile (HDL/non-HDL ratio) and enhanced the infarct-sparing effect of IP in CD-fed mice. In HFD-fed mice, NAC restored the efficacy of IP, significantly reducing infarct size (HFD-I/R-NAC: 39.7 ± 4.5% vs. HFD-IP-NAC: 26.4 ± 2.0%, p < 0.05) without changes in ventricular function. The ratio of oxidized/reduced glutathione (GSSG/GSH) is depicted. Under basal conditions, the hearts of mice fed an HFD exhibited a shift towards a more oxidized state compared to the control diet CD group. In the I/R protocol, a significant shift towards a more oxidized state was observed in both CD and HFD-fed animals. In the IP protocol, the GSSG/GSH ratio revealed a tendency to basal values in comparison to the I/R protocol. The analysis indicates that animals subjected to I/R and IP protocols in conjunction with NAC show a tendency to reach basal values, thus suggesting a potential for the reduction in ROS. Conclusions: NAC treatment mitigates oxidative stress and restores the cardioprotective effect of ischemic postconditioning in a model of early-stage atherosclerosis. These findings support NAC as a potential adjunct therapy to improve myocardial resistance to reperfusion injury under dyslipidemic conditions Full article

This study investigated the protective effects of high selenomethionine (SeMet) supplementation on liver injury caused by oxidative stress in piglets and explored the underlying mechanisms. A total of 18 piglets were randomly assigned to three groups, with six replicates in each group. The control (CON) and diquat (DQ) groups were fed a basal diet supplemented with 0.3 mg Se/kg Se, while the SeMet group received a basal diet supplemented with 1.0 mg Se/kg. The results indicated that SeMet supplementation significantly improved growth performance and increased the serum and liver activities of antioxidant enzymes. Additionally, it reduced the serum and liver levels of malondialdehyde and protein carbonyls in piglets exposed to DQ. Selenoprotein transcriptome analysis showed that the mRNA levels of five selenoprotein genes (GPX1/3, DIO2, and SELENOF/M/W) were significantly upregulated by dietary SeMet supplementation in the liver of DQ-challenged piglets. Proteomic analysis revealed that a total of 3614 proteins were identified in the liver of piglets. Among them, 85 differentially expressed proteins (DEPs) were identified between the CON and DQ groups, 58 DEPs were observed between the DQ and SeMet groups, and 113 DEPs were identified between the CON and SeMet groups. KEGG analysis indicated that most of the DEPs observed among the three groups were involved in fatty acid metabolism, glycolysis/gluconeogenesis, and the PPAR signaling pathway. Together, these results indicate that dietary supplementation with supernutritional SeMet alleviates the negative effects of the DQ challenge on growth performance and liver injury in piglets. This effect is associated with increased antioxidant capacity, enhanced expression of certain selenoprotein genes, and the regulation of fatty acid metabolism. Full article