Search Results (71)

Oxidative stress is a key mediator of physiological dysfunction in aquatic organisms under environmental challenges, yet its comprehensive impacts on gill physiology require further clarification. This study investigated the molecular and cellular responses of Eriocheir sinensis gills to hydrogen peroxide (H₂O₂)-induced oxidative stress, integrating antioxidant defense, ion transport regulation, and stress-induced cell apoptosis and autophagy. Morphological alterations in the gill filaments were observed, characterized by septum degeneration, accumulation of haemolymph cells, and pronounced swelling. For antioxidant enzymes like catalase (CAT) and glutathione peroxidase (GPx), activities were enhanced, while superoxide dismutase (SOD) activity was reduced following 48 h of exposure. Overall, the total antioxidant capacity (T-AOC) showed a significant increase. The elevated concentrations of malondialdehyde (MDA) and H₂O₂ indicated oxidative stress. Ion transport genes displayed distinct transcription patterns: Na⁺-K⁺-2Cl⁻ co-transporter-1 (NKCC1), Na⁺/H⁺ exchanger 3 (NHE3), aquaporin 7 (AQP7), and chloride channel protein 2 (CLC2) were significantly upregulated; the α-subunit of Na⁺/K⁺-ATPase (NKAα) and carbonic anhydrase (CA) displayed an initial increase followed by decline; whereas vacuolar-type ATPase (VATP) consistently decreased, suggesting compensatory mechanisms to maintain osmotic balance. Concurrently, H₂O₂ triggered apoptosis (Bcl2, Caspase-3/8) and autophagy (beclin-1, ATG7), likely mediated by MAPK and AMPK signaling pathways. These findings reveal a coordinated yet adaptive response of crab gills to oxidative stress, providing new insights into the mechanistic basis of environmental stress tolerance in crustaceans. Full article

Diabetes is a risk factor for periodontitis. Increasing evidence suggests that a central player in this link is the vacuolar H+-ATPase (V-ATPase), which provides a physical and functional core for regulation by the catabolic lysosomal AMP-activated protein kinase complex (L-AMPK) and the anabolic mammalian target of rapamycin complex 1 (mTORC1). These complexes detect levels of various cellular nutrients, including glucose at the lysosome, and promote cellular responses to restore homeostasis. The high-glucose conditions of diabetes foster anabolic mTORC1 signaling that increases inflammation and inflammatory bone resorption in response to periodontal infections. Here, we review the structure and composition of V-ATPase, L-AMPK, mTORC1, and other elements of the energy-sensing platform. Mechanisms by which V-ATPase passes signals to the complexes are examined and recent data are reviewed. Current anti-bone resorptive therapeutics, bisphosphonates and denosumab, enhance the risk of medicine-related osteonecrosis of the jaw (MRONJ) and are not used to treat periodontal bone loss. Accumulating data suggest that it may be possible to target inflammatory bone resorption through agents that stimulate L-AMPK, including metformin and glucagon-like peptide-1 agonists. This approach may reduce inflammatory bone resorption without major effects on overall bone remodeling or increased risk of MRONJ. Full article

Rising water temperatures due to climate change pose a significant threat to Phoxinus lagowskii, a cold-water fish that is ecologically vital to the high-latitude regions of China. This study assessed heat stress effects on behavioral, hematological, histological, physiological, and molecular responses in P. lagowskii. The critical maximum temperature (CT_max) was determined using the loss of equilibrium (LOE) method, with the CT_max reaching 29 °C. Elevated temperatures lead to an increase in the OBR. Fish were subjected to acute heat stress at 28 °C (below CT_max) for 48 h, with samples collected during the 48 h period. RBC, WBC, HGB, and HCT significantly increased during heat stress but decreased 12 h after heat stress. The levels of serum cortisol and blood glucose after heat stress were significantly higher than those in the control group. After heat stress, the height of the ILCM in the gills increased significantly, and the liver exhibited vacuolar degeneration and hypopigmentation. The activities of Na⁺-K⁺-ATPase and Ca²⁺-Mg²⁺-ATPase in the gills initially increased and then decreased over the duration of heat stress. Most enzyme activities (PK, LDH, PFK, and HK) decreased during heat stress, while LPL and HL levels increased, indicating that lipid metabolism was the primary utilization process under heat stress. There was an increase in SOD activity at 12 h, followed by a decrease at 24 h, and an increase in CAT activity under heat stress. Integrated biomarker response (IBR) and principal component analysis (PCA) were employed to synthesize multi-level responses. The IBR values reached their peak at 3 h and 48 h of heat stress. We observed an upregulation of heat shock proteins (Hsp70, Hsp90, and Hsc70) as well as interleukin-10 (IL-10) in response to heat stress. Our findings offer novel insights into the mechanisms underlying the heat stress response in P. lagowskii, thereby enhancing our understanding of the effects of heat stress on cold-water fish. Full article

Low-acid apples are popular among consumers, but the mechanisms behind the complex differences in acidity among varieties that are caused by high altitude are not clear. In this study, we used the ‘Golden Delicious’ apple and its superior variant in the Western Sichuan Plateau of China to analyze organic acid composition, content, and the expression levels of related regulated genes during fruit development. We found that the organic acid content in the variant was significantly lower than that in the ‘Golden Delicious’ apple. In both apples, quinic and malic acids were the predominant organic acids, while citric and tartaric acids were present in lower amounts. In this multidimensional regulatory study, we used transcriptome sequencing, cluster analysis, and weighted gene co-expression network analysis (WGCNA) to reveal that differentially expressed genes are enriched in multiple pathways affecting fruit acidity during apple development; malate dehydrogenase (MDH) affects the malic acid content of fruits of different varieties; and H⁺-ATPase (VHA) mainly regulates the content of vacuolar organic acids, which affects fruit acidity. Additionally, we performed qRT-PCR experiments to validate our results. This study provides molecular insights into the mechanisms by which low-acidity traits form in apples and offers a theoretical basis for regulating the flavor of fleshy fruits. Full article

The vacuolar-type ATPase (V-ATPase) is a multi-subunit enzyme complex that maintains lysosomal acidification, a critical process for cellular homeostasis. By controlling the pH within lysosomes, V-ATPase contributes to overall cellular homeostasis, helping to maintain a balance between the degradation and synthesis of cellular components. Dysfunction of V-ATPase impairs lysosomal acidification, leading to the accumulation of undigested materials and contributing to various diseases, including cardiovascular diseases (CVDs) like atherosclerosis and myocardial disease. Furthermore, V-ATPase’s role in lysosomal function suggests potential therapeutic strategies targeting this enzyme complex to mitigate cardiovascular disease progression. Understanding the mechanisms by which V-ATPase influences cardiovascular pathology is essential for developing novel treatments aimed at improving outcomes in patients with heart and vascular diseases. Full article

Background and Objective: Mammea siamensis (MS) is a Thai herb used in traditional medicine. Previous studies have reported the antiproliferative effects of its constituents in various cancer cell lines. However, the effects of MS extract on cytotoxicity and molecular mechanisms of apoptosis induction in HCT116 colon cancer cells have not been fully explored. Methods and Results: The cytotoxic effect of MS extract on HCT116 cells was assessed using the MTT assay. MS extract increased cytotoxicity in a concentration-dependent manner. It also induced nuclear morphological changes and disrupted the mitochondrial membrane potential (ΔΨm), as assessed by Hoechst 33342 and JC-1 staining, respectively. These findings indicated that MS extract induced apoptosis, which was further confirmed by flow cytometry showing an increase in the sub-G1 phase. To investigate the expression of signaling proteins, Western blot analysis was conducted. The results showed that MS extract activated caspase activity (caspase-8, -9, and -7) and inhibited PARP activity. Additionally, MS extract upregulated pro-apoptotic proteins (tBid, Bak, and cytochrome c) while downregulating anti-apoptotic proteins (Bcl-2 and Bcl-xL). Mechanistic studies revealed that MS extract activated MAPK pathways while inactivating the PI3K/Akt/NF-κB and GSK-3β/β-catenin pathways. Notably, MS extract also inhibited V-ATPases, as evaluated by acridine orange staining and Western blot analysis. Conclusions: Our findings suggest that MS extract induces apoptosis via the activation of both intrinsic and extrinsic pathways associated with the key signaling pathways. Therefore, MS extract shows potential as a therapeutic agent for colon cancer. Full article

Background/Objectives: Vacuolar (H⁺)-ATPases (V-ATPases) are crucial in several significant biological processes, including intracellular transport, endocytosis, autophagy and protein degradation. However, their role in the growth and development of insects remains largely unknown. This study aimed to explore the molecular and functional properties of V-ATPases in Locusta migratoria. Methods: LmV-ATPase genes were identified based on the locust transcriptome database and bioinformatics analysis. Quantitative reverse-transcription polymerase chain reaction was used to assess the relative expression of LmV-ATPases in different tissues and developmental stages. RNA interference combined with hematoxylin–eosin staining and transmission electron microscopy was used to explore the functions of LmV-ATPases. Results: Ten V-ATPase genes were identified in L. migratoria and were named LmV-ATPase A, B, C, D, E, F, G, c″, d and e, respectively. These genes were highly expressed in the head, integument, gastric caecum, midgut, hindgut, fat body, trachea and ovary. The transcripts of LmV-ATPases were expressed in the developmental stages examined (from the 3rd to 5th instar nymphs). The injection of double-stranded RNA (dsRNA) against each LmV-ATPase induced high silencing efficiency in the 3rd instar nymphs. Knockdown of LmV-ATPases resulted in lethal phenotypes, with visible defects of the wing and cuticle. We further demonstrated that the deformation was caused by the defects of epidermal cells and fewer new cuticles. Conclusions: These findings suggest that LmV-ATPases are required for the wing and cuticle development of L. migratoria, which could be potential targets for the control of locusts. Full article

Mutual interaction between doxorubicin (DOX) and cardiomyocytes is crucial for cardiotoxicity progression. Cardiomyocyte injury is an important pathological feature of DOX-induced cardiomyopathy, and its molecular pathogenesis is multifaceted. In addition to the direct toxic effects of DOX on cardiomyocytes, DOX-induced exosomes in the extracellular microenvironment also regulate the pathophysiological states of cardiomyocytes. However, the mechanisms by which DOX regulates exosome secretion and subsequent pathogenesis remain incompletely understood. Here, we found that DOX significantly increased exosome secretion from cardiomyocytes, and inhibiting this release could alleviate cardiomyocyte injury. DOX promoted exosome secretion by reducing cardiomyocyte silencing information regulator 1 (SIRT1) expression, exacerbating cardiotoxicity. DOX impaired lysosomal acidification in cardiomyocytes, reducing the degradation of intracellular multivesicular bodies (MVBs), resulting in an increase in MVB volume before fusing with the plasma membrane to release their contents. Mechanistically, SIRT1 loss inhibited lysosomal acidification by reducing the expression of the ATP6V1A subunit of the lysosomal vacuolar-type H+ ATPase (V-ATPase) proton pump. Overexpressing SIRT1 increased ATP6V1A expression, improved lysosomal acidification, inhibited exosome secretion, and thereby alleviated DOX-induced cardiotoxicity. Interestingly, DOX also induced mitochondrial-derived vesicle formation in cardiomyocytes, which may further increase the abundance of MVBs and promote exosome release. Collectively, this study identified SIRT1-mediated impairment of lysosomal acidification as a key mechanism underlying the increased exosome secretion from cardiomyocytes induced by DOX, providing new insights into DOX-induced cardiotoxicity pathogenesis. Full article

Cry2Ab is a significant alternative Bacillus thuringiensis (Bt) protein utilized for managing insect resistance to Cry1 toxins and broadening the insecticidal spectrum of crops containing two or more Bt genes. Unfortunately, the identified receptors fail to fully elucidate the mechanism of action underlying Cry2Ab. Previous studies have demonstrated the involvement of vacuolar H⁺-ATPase subunits A, B, and E (V-ATPase A, B, and E) in Bt insecticidal activities. The present study aims to investigate the contribution of V-ATPase C to the toxicities of Cry2Ab against Helicoverpa armigera. The feeding of Cry2Ab in H. armigera larvae resulted in a significant decrease in the expression of V-ATPase C. Further investigations confirmed the interaction between V-ATPase C and activated Cry2Ab protein according to Ligand blot and homologous and heterologous competition assays. Expressing endogenous HaV-ATPase C in Sf9 cells resulted in an increase in Cry2Ab cytotoxicity, while the knockdown of V-ATPase C by double-stranded RNAs (dsRNA) in midgut cells decreased Cry2Ab cytotoxicity. Importantly, a higher toxicity of the mixture containing Cry2Ab and V-ATPase C against insects was also observed. These findings demonstrate that V-ATPase C acts as a binding receptor for Cry2Ab and is involved in its toxicity to H. armigera. Furthermore, the synergy between V-ATPase C protein and Cry2Ab protoxins provides a potential strategy for enhancing Cry2Ab toxicity or managing insect resistance. Full article

Vacuolar-type ATPase (v-ATPase) is a multimeric protein complex that regulates H⁺ transport across membranes and intra-cellular organelle acidification. Catabolic processes, such as endocytic degradation and autophagy, strictly rely on v-ATPase-dependent luminal acidification in lysosomes. The v-ATPase complex is expressed at high levels in the brain and its impairment triggers neuronal dysfunction and neurodegeneration. Due to their post-mitotic nature and highly specialized function and morphology, neurons display a unique vulnerability to lysosomal dyshomeostasis. Alterations in genes encoding subunits composing v-ATPase or v-ATPase-related proteins impair brain development and synaptic function in animal models and underlie genetic diseases in humans, such as encephalopathies, epilepsy, as well as neurodevelopmental, and degenerative disorders. This review presents the genetic and functional evidence linking v-ATPase subunits and accessory proteins to various brain disorders, from early-onset developmental epileptic encephalopathy to neurodegenerative diseases. We highlight the latest emerging therapeutic strategies aimed at mitigating lysosomal defects associated with v-ATPase dysfunction. Full article

Vacuolar (H⁺)-ATPases (V-ATPases) are ATP-driven proton pumps that play multifaceted roles across various organisms. Despite their widespread significance, the functional implications of V-ATPase genes in Hyphantria cunea, an invasive forest pest with a global presence, have yet to be elucidated. In this study, two specific V-ATPase genes from H. cunea were identified and analyzed, namely HcV-ATPase A (accession number: OR217451) and HcV-ATPase C (accession number: OR217452). Phylogenetic analysis and multiple sequence alignment reveal that HcV-ATPase A shares the highest amino acid sequence similarity with SfV-ATPase A, while HcV-ATPase C is most similar to HaV-ATPase C. Spatiotemporal expression profiles, determined via RT-qPCR, demonstrate that both HcV-ATPase A and HcV-ATPase C are expressed throughout all larval developmental stages, with HcV-ATPase A predominantly expressed in the midgut and HcV-ATPase C showing high expression in the epidermis. RNA interference (RNAi) targeting of these genes significantly suppressed their expression by 62.7% and 71.0% 120 h post-injection, leading to halted larval growth and increased mortality rates of 61.7% and 46.7%, respectively. Further investigations using immunohistochemistry, hematoxylin and eosin (HE) staining, and transmission electron microscopy (TEM) revealed that gene silencing induced vesiculation and subsequent losses or sloughing of intestinal parietal cells, alongside an increase in the number of autophagic cells. Additionally, the silencing of HcV-ATPase A and C genes resulted in a reduced gut epidermal cell layer thickness and further increases in goblet cell numbers. Importantly, RNAi of HcV-ATPase A and C did not affect the expression levels of one another, suggesting independent functional pathways. This study provides foundational insights into the role of V-ATPase in H. cunea and identifies potential targets for the biocontrol of its larvae, contributing to the understanding of V-ATPase mechanisms and their application in pest management strategies. Full article

Organic acids play critical roles in fruit physiological metabolism and sensory quality. However, the conventional storage of apple fruit at 0 ± 0.1 °C cannot maintain fruit acidity efficiently. This study investigated near-freezing temperature (NFT) storage for ‘Golden Delicious’ apples, and the quality parameters, organic acid content, and malate metabolism were studied. The results indicate that NFT storage at −1.7 ± 0.1 °C effectively maintained the postharvest quality of apple fruit when compared to traditional storage at 0 ± 0.1 °C. Fruit that underwent NFT storage showed a better appearance and lower respiratory rate, ethylene production, weight loss, and malondialdehyde (MDA) content but higher firmness and soluble solids content. Further, fruit after NFT storage contained higher titratable acid (18.75%), malate (51.61%), citrate (36.59%), and succinate (2.12%) content when compared to the control after 250 days. This was achieved by maintaining higher cytosolic NAD-dependent malate dehydrogenase (cyNAD-MDH), phosphoenolpyruvate carboxylase (PEPC), vacuolar H⁺-ATPase (V-ATPase), and vacuolar inorganic pyrophosphatase (V-PPase) activities that promote malate biosynthesis and accumulation while inhibiting enzyme activity that is responsible for malate decomposition, including phosphoenolpyruvate carboxylase kinase (PEPCK) as well as the cytosolic NAD phosphate-dependent malic enzyme (cyNADP-ME). Further, storage at NFTs maintained a higher expression of malate biosynthesis-related genes (MdcyNAD-MDH and MdPEPC) and transport-related genes (MdVHA and MdVHP) while suppressing malate consumption-related genes (MdcyME and MdPEPCK). The results demonstrate that NFT storage could be an effective application for apple fruit, which maintains postharvest quality and alleviates organic acid degradation. Full article

In Saccharomyces cerevisiae, pH homeostasis is reliant on ATP due to the use of proton-translocating ATPase (H⁺-ATPase) which constitutes a major drain within cellular ATP supply. Here, an exogenous proton-translocating pyrophosphatase (H⁺-PPase) from Arabidopsis thaliana, which uses inorganic pyrophosphate (PP_i) rather than ATP, was evaluated for its effect on reducing the ATP burden. The H⁺-Ppase was localized to the vacuolar membrane or to the cell membrane, and their impact was studied under acetate stress at a low pH. Biosensors (pHluorin and mQueen-2m) were used to observe changes in intracellular pH (pH_i) and ATP levels during growth on either glucose or xylose. A significant improvement of 35% in the growth rate at a pH of 3.7 and 6 g·L⁻¹ acetic acid stress was observed in the vacuolar membrane H⁺-PPase strain compared to the parent strain. ATP levels were elevated in the same strain during anaerobic glucose and xylose fermentations. During anaerobic xylose fermentations, co-expression of pHluorin and a vacuolar membrane H⁺-PPase improved the growth characteristics by means of an improved growth rate (11.4%) and elongated logarithmic growth duration. Our study identified a potential method for improving productivity in the use of S. cerevisiae as a cell factory under the harsh conditions present in industry. Full article

The vacuolar proton-translocating ATPase (V-ATPase) is a transmembrane multi-protein complex fundamental in maintaining a normal intracellular pH. In the tumoral contest, its role is crucial since the metabolism underlying carcinogenesis is mainly based on anaerobic glycolytic reactions. Moreover, neoplastic cells use the V-ATPase to extrude chemotherapy drugs into the extra-cellular compartment as a drug resistance mechanism. In glioblastoma (GBM), the most malignant and incurable primary brain tumor, the expression of this pump is upregulated, making it a new possible therapeutic target. In this work, the bafilomycin A1-induced inhibition of V-ATPase in patient-derived glioma stem cell (GSC) lines was evaluated together with temozolomide, the first-line therapy against GBM. In contrast with previous published data, the proposed treatment did not overcome resistance to the standard therapy. In addition, our data showed that nanomolar dosages of bafilomycin A1 led to the blockage of the autophagy process and cellular necrosis, making the drug unusable in models which are more complex. Nevertheless, the increased expression of V-ATPase following bafilomycin A1 suggests a critical role of the proton pump in GBM stem components, encouraging the search for novel strategies to limit its activity in order to circumvent resistance to conventional therapy. Full article

As the only aquatic lineage of Pteridaceae, Parkerioideae is distinct from many xeric-adapted species of the family and consists of the freshwater Ceratopteris species and the only mangrove ferns from the genus Acrostichum. Previous studies have shown that whole genome duplication (WGD) has occurred in Parkerioideae at least once and may have played a role in their adaptive evolution; however, more in-depth research regarding this is still required. In this study, comparative and evolutionary transcriptomics analyses were carried out to identify WGDs and explore their roles in the environmental adaptation of Parkerioideae. Three putative WGD events were identified within Parkerioideae, two of which were specific to Ceratopteris and Acrostichum, respectively. The functional enrichment analysis indicated that the lineage-specific WGD events have played a role in the adaptation of Parkerioideae to the low oxygen concentrations of aquatic habitats, as well as different aquatic environments of Ceratopteris and Acrostichum, such as the adaptation of Ceratopteris to reduced light levels and the adaptation of Acrostichum to high salinity. Positive selection analysis further provided evidence that the putative WGD events may have facilitated the adaptation of Parkerioideae to changes in habitat. Moreover, the gene family analysis indicated that the plasma membrane H⁺-ATPase (AHA), vacuolar H⁺-ATPase (VHA), and suppressor of K⁺ transport growth defect 1 (SKD1) may have been involved in the high salinity adaptation of Acrostichum. Our study provides new insights into the evolution and adaptations of Parkerioideae in different aquatic environments. Full article