Regulation Of Transport Research Articles

Molecular Mechanisms Underlying Substance Transport, Signal Transduction, and Anti-Stress Regulation, as Well as Anti-Alkaline Regulation via Bursicon in the Cerebral Ganglion of Chinese Mitten Crab Eriocheir sinensis Under Alkaline Stress

(1) Background: Global climate change is intensifying, and the vigorous development and utilization of saline–alkali land is of great significance. As an important economic aquatic species in the context of saline–alkali aquaculture, it is highly significant to explore the regulatory mechanisms of Eriocheir sinensis under alkaline conditions. In particular, the brain (cerebral ganglion for crustaceans) serves as a vital regulatory organ in response to environmental stress; (2) Methods: In this study, a comparative transcriptome approach was employed to investigate the key regulatory genes and molecular regulatory mechanisms in the cerebral ganglion of E. sinensis under alkaline stress. (3) Results: The results demonstrated that the cerebral ganglion of E. sinensis exhibited a positive response to acute alkaline stress. Pathways associated with signal transduction and substance transportation, such as “phagosome” and “regulation of actin cytoskeleton”, along with regulatory genes involved in antioxidation, were upregulated synergistically to maintain homeostasis under alkaline stress. Furthermore, it was discovered for the first time that bursicon plays a positive regulatory role in the adaptation of E. sinensis to alkalinity. (4) Conclusions: The present study elucidates the molecular regulatory pattern of the cerebral ganglion in E. sinensis under acute alkaline stress as well as revealing a novel role of bursicon in facilitating adaptation to alkalinity in E. sinensis, providing valuable theoretical insights into the molecular regulatory mechanisms underlying the responses of cerebral ganglia to saline–alkali environments. These findings also offer a theoretical reference for promoting the sustainable development of the E. sinensis breeding industry under saline–alkali conditions.

Autophagy regulator ATG5 preserves cerebellar function by safeguarding its glycolytic activity

Abstract Dysfunctions in autophagy, a cellular mechanism for breaking down components within lysosomes, often lead to neurodegeneration. The specific mechanisms underlying neuronal vulnerability due to autophagy dysfunction remain elusive. Here we show that autophagy contributes to cerebellar Purkinje cell (PC) survival by safeguarding their glycolytic activity. Outside the conventional housekeeping role, autophagy is also involved in the ATG5-mediated regulation of glucose transporter 2 (GLUT2) levels during cerebellar maturation. Autophagy-deficient PCs exhibit GLUT2 accumulation on the plasma membrane, along with increased glucose uptake and alterations in glycolysis. We identify lysophosphatidic acid and serine as glycolytic intermediates that trigger PC death and demonstrate that the deletion of GLUT2 in ATG5-deficient mice mitigates PC neurodegeneration and rescues their ataxic gait. Taken together, this work reveals a mechanism for regulating GLUT2 levels in neurons and provides insights into the neuroprotective role of autophagy by controlling glucose homeostasis in the brain.

Ocular inoculation of toad venom: toxic cataract and proteomic profiling

PurposeTo report a singular case of cataract caused by toad venom inoculation and to scrutinize the pathological mechanisms through proteomic sequencing of the lens specimen.MethodsA young Chinese male presented with progressively deteriorating vision in his right eye subsequent to a history of toad venom inoculation. He was diagnosed with a toxic cataract, and underwent phacoemulsification cataract surgery. Anterior capsule, nucleus, and cortex specimens from the patient (designated as PT_CAP, PT_PHACO, and PT_CTX, respectively) and age-related cataract controls (C_CAP, C_PHACO, and C_CTX, respectively) were collected and subjected to 4D label-free quantitative proteomics.ResultsA multitude of differentially expressed proteins (DEPs) were identified in the patient’s lens compared to those in the controls. Specifically, a total of 204 DEPs were identified in PT_CAP compared to C_CAP, with MYH6, MYL2, MYL3, STAT1, and ANK1 among the foremost regulated DEPs. The DEPs of PT_CAP were principally affiliated with functions including “transportation of small molecules,” “regulation of metal ion transport,” and “import into cell.” A sum of 109 DEPs were delineated in PT_CTX compared to C_CTX, with TPM1 among the top-10 downregulated DEPs. Ninety-five DEPs were pinpointed in PT_PHACO compared to C_PHACO, with hexokinase among the top 10 downregulated DEPs. These proteins were ascertained to be linked with Na+/K+-ATPase activity.ConclusionThis study introduced the first documented case of toxic cataract caused by toad venom inoculation. Proteomic sequencing indicated a correlation between cataract and alterations in Na+/K+-ATPase activity, providing insights for the clinical management of ocular toad venom inoculation in subsequent cases.

Kifunensine-sensitive ADP-ribosylation factor A1EG69R mutant revealed coordination of protein glycosylation and vesicle transport pathways.

Complex N-glycans are asparagine (N)-linked branched sugar chains attached to secretory proteins in eukaryotes. They are produced by modification of N-linked oligosaccharide structures in the endoplasmic reticulum (ER) and Golgi apparatus. Complex N-glycans formed in the Golgi apparatus are often assigned specific roles unique to the host organism, with their roles in plants remaining largely unknown. Using inhibitor (kifunensine, KIF)-hypersensitivity as read-out, we identified Arabidopsis mutants that require complex N-glycan modification. Among over 100 KIF-sensitive mutants, one showing abnormal secretory organelles and a salt-sensitive phenotype contained a point mutation leading to amino-acid replacement (G69R) in ARFA1E, a small Arf1-GTPase family protein presumably involved in vesicular transport. In-vitro assays showed that the G69R exchange interferes with protein activation. In vivo, ARFA1EG69R caused dominant-negative effects, altering the morphology of the ER, Golgi apparatus, and trans-Golgi network (TGN). Post-Golgi transports (endocytosis/endocytic recycling) of essential glycoprotein KORRIGAN1, one of KIF-sensitivity targets, is slowed down constitutively as well as under salt stress in ARFA1EG69R mutant. Because regulated cycling of plasma membrane proteins is required for stress tolerance of the host plants, ARFA1EG69R mutant established a link between KIF-targeted luminal glycoprotein functions/dynamics and cytosolic regulators of vesicle transport in endosome-/cell wall-associated tolerance mechanisms.

Dietary purslane (Portulaca oleracea L.) leaf powder maintains growth and intestinal health in Oreochromis niloticus under chronic water-borne cadmium exposure by strengthening the gut barriers, modulating the intestinal nutrient transporters, and relieving oxidative stress.

High cadmium (Cd) concentrations pose a threat to aquatic life globally. This study examined the efficiency of adding purslane (Portulaca oleracea L.) leaf powder (PLP) to Oreochromis niloticus diets on Cd's negative effects. PLP was analyzed using high-performance liquid chromatography, and its main constituents were gallic acid, chlorogenic acid, and pyrocatechol. Nile tilapia (180 fish, 34.5 ± 0.5 g) were divided into four groups in triplicate. A basal diet was given to the control group. The PLP group received a basal diet containing 10 g PLP/kg diet. The Cd group was exposed to 50 µg/L water. The Cd + PLP group was exposed to Cd and fed diets containing PLP. Results showed that PLP significantly rescued Cd-induced effects. PLP improved fish survival, feed conversion ratio, and growth retardation caused by Cd. PLP also restored decreased activities of lipase, trypsin, and amylase in the intestine. Furthermore, PLP corrected disturbances in leptin and growth hormone levels induced by Cd. PLP mitigated pathological alterations, replenished antioxidants (SOD, CAT, and GSH), and reduced lipid peroxidation in the intestinal tissues. PLP supplementation depleted significant Cd accumulation in the intestine and muscles. Additionally, PLP corrected altered expressions of tight junction proteins (zo-1, zo-2, and claudin-4) and nutrient transporters (glut-1, slc15a2, slc26a6, and slc4a4) in Cd-exposed fish. Conclusively, PLP shows promise as a dietary supplement to mitigate Cd's harmful impacts on fish growth. Its antioxidant activity and regulation of intestinal tight junction proteins and nutrient transporters contribute to its effectiveness. PLP supplementation holds the potential for reducing the detrimental effects of Cd in aquaculture.

Noncanonical RGS14 structural determinants control hormone-sensitive NPT2A-mediated phosphate transport.

The sodium phosphate cotransporter-2A (NPT2A) mediates basal and parathyroid hormone (PTH)- and fibroblast growth factor-23 (FGF23)-regulated phosphate transport in proximal tubule cells of the kidney. Both basal and hormone-sensitive transport require sodium hydrogen exchanger regulatory factor-1 (NHERF1), a scaffold protein with tandem PDZ domains, PDZ1 and PDZ2. NPT2A binds to PDZ1. RGS14 persistently represses hormone action by binding to PDZ2. The RGS14 canonical RGS domain, Ras/Rap-binding domains, and G protein regulatory motif cannot explain its regulatory effects on hormone-sensitive phosphate transport because these actions are mediated not only by the PTH receptor, a G protein-coupled receptor (GPCR), but also by the fibroblast growth factor receptor-1, a receptor tyrosine kinase that is not governed by G protein activity. Here, we identify the structural elements of RGS14 that mutually control the action of PTH and FGF23. RGS14 truncation constructs lacking upstream sequence and the RGS domain were fully functional. Removing the linker sequence between the RGS and RBD1 domains abolished RGS14 action. Examination of the alpha-helical linker region suggested candidate serine residues that might facilitate regulatory activities. RGS14 Ser266 and Ser269 are phosphorylated in response to PTH and FGF23, and replacement of these residues by Ala eliminated the actions of RGS14 on hormone-sensitive phosphate transport. PTH stimulated the phosphorylation of a peptide construct harboring the sites of purported phosphorylation and full-length RGS14. Mutating Ser266Ala and Ser269Ala abolished phosphorylation. The results establish that RGS14 regulation of phosphate transport requires targeted phosphorylation within the linker and an intact PDZ ligand.

Conformational switches in human RNA binding proteins involved in neurodegeneration.

Conformational switching in RNA binding proteins (RBPs) are crucial for regulation of RNA processing and transport. Dysregulation or mutations in RBPs and broad RNA processing abnormalities are related to many human diseases including neurodegenerative disorders. Here, we review the role of protein-RNA conformational switches in RBP-RNA complexes. RBP-RNA complexes exhibit wide range of conformational switching depending on the RNA molecule and its ability to induce conformational changes in its partner RBP. We categorize the conformational switches into three groups: rigid body, semi-flexible and full flexible. We also investigate conformational switches in large cellular assemblies including ribosome, spliceosome and RISC complexes. In addition, the role of intrinsic disorder in RBP-RNA conformational switches is discussed. We have also discussed the effect of different disease-causing mutations on conformational switching of proteins associated with neurodegenerative diseases. We believe that this study will enhance our understanding on the role of protein-RNA conformational switches. Furthermore, the availability of many more atomic structures of RBP-RNA complexes in near future would facilitate to create a complete repertoire of human RBP-RNA conformational switches.

Avian pathogenic Escherichia coli alters complement gene expression in chicken erythrocytes.

1. Avian Escherichia coli (E. coli) causes significant losses in livestock by inducing morbidity and mortality. Erythrocytes, the most abundant in blood, possess dual functions of oxygen transportation and immune regulation. In recent years, the interaction between erythrocytes and the complement system has gradually become a focal point of study. However, the transcription dynamics of the complement system in chicken erythrocytes post-E. coli invasion remains unclear.2. In this study, chicken erythrocytes and E. coli were co-cultured for 0.25-2 h to assess adhesion, analysed by indirect immunofluorescence (IIF) and scanning electron microscopy (SEM). Quantitative real-time PCR (qRT-PCR) examined differential expression of complement genes (CD93, C1q, C1s, C2, C3, C3AR1, C4, C4A, C5, C5AR1, C6, C7, C8G, CFI, MBL) in vitro using erythrocytes at 0.25-2 h and in vivo using chicks at 1, 3 and 7 d post-E. coli infection.3. E. coli adheres to chicken erythrocytes, as observed using IF and SEM. Gene expression analysis revealed early downregulation of C4, C4A, MBL and late upregulation of CD93, C1q, C1s, C3, C3AR1, C5AR1, C6, with C5, C7, C8G downregulated at 7 dpi. C2 expression varied at each time point.4. This study first showed E. coli adhering to erythrocytes, which activated complement genes rapidly. In vivo recovery from chickens with colibacillosis favours classical pathway activation, while lectin pathway may be inhibited, suggesting early immune down-regulation.

RTN4IP1 Contributes to ESCC via Regulation of Amino Acid Transporters.

Esophageal squamous cell carcinoma (ESCC) accounts for about 90% of esophageal cancer cases. The lack of effective therapeutic targets makes it difficult to improve the overall survival of patients with ESCC. Reticulon 4 Interacting Protein 1 (RTN4IP1) is a novel mitochondrial oxidoreductase. Here, a notable upregulation of RTN4IP1 is demonstrated, which is associated with poor survival in patients with ESCC. RTN4IP1 depletion impairs cell proliferation and induces apoptosis of ESCC cells. Furthermore, c-Myc regulates RTN4IP1 expression via iron regulatory protein 2 (IRP2) at the post-transcriptional level. Mechanistically, RTN4IP1 mRNA harbors functional iron-responsive elements (IREs) in the 3' UTR, which can be targeted by IRP2, resulting in increased mRNA stability. Finally, RTN4IP1 depletion abrogates amino acid uptake and induces amino acid starvation via downregulation of the amino acid transporters SLC1A5, SLC3A2, and SLC7A5, indicating a possible pathway through which RTN4IP1 contributes to ESCC carcinogenesis and progression. In vivo studies using cell-derived xenograft and patient-derived xenograft mouse models as well as a 4-nitroquinoline 1-oxide-induced ESCC model in esophageal-specific Rtn4ip1 knockout mice demonstrate the essential role of RTN4IP1 in ESCC development. Thus, RTN4IP1 emerges as a key cancer-promoting protein in ESCC, suggesting therapeutic RTN4IP1 suppression as a promising strategy for ESCC treatment.

Dynamic regulation of ion transport through a bis(1,3-propanediol)-based channel via allosteric azobenzene photoswitching.

The transportation of ions across cell membranes is vital in biological functions and is frequently controlled by external triggers like light, ligands, and voltage. Synthetic ion transport systems, particularly those featuring gating mechanisms, have attracted considerable interest. In this research, we engineered self-assembled barrel rosette ion channels using a photoresponsive azobenzene integrated at an allosteric site. Morphological studies verified more effective self-assembly of the trans form in contrast to the cis form. The restricted self-assembly of the cis form can be ascribed to the nonplanar structure of cis azobenzene moieties, which inhibits favorable π-π stacking interactions. The ion transport studies demonstrated the formation of ion channels by the trans form with anion antiport as the primary transport mechanism. In contrast, the cis form exhibited lower efficiency. Based on these observations, dynamically gated ion transport was achieved by employing two sets of electromagnetic radiation at 365 nm and 450 nm, respectively. Molecular dynamics simulation studies demonstrated that the channel formed by assembling trans monomers exhibited greater stability when compared to the channel formed by cis monomers. Additionally, the trans channel was found to recognize and transport chloride effectively.

Quantitative proteomic landscape of the pathophysiology of adhesive arachnoiditis and its clinical significance: Structure and mechanism of TNC and RANBP1 proteins.

The pathophysiological mechanism of adhesive arachnoiditis (AA) is complex, involving the interaction of multiple proteins. In recent years, the development of quantitative proteomics technology has provided a new perspective to reveal its pathological mechanism. The main objective of this study was to reveal the changes of protein expression profiles in arachnoid tissue of patients with AA. Proteomic analysis of arachnoid tissue samples was performed by high-throughput mass spectrometry. Bioinformatics tools were used to process and analyze the data and screen out 712 differentially expressed proteins (DEPs). Specially, 2 hub DEPs (TNC and RANBP1) were found as potential diagnostic markers. The expression levels of TNC and RANBP1 proteins were significantly up-regulated in patients with AA. TNC protein played a key role in inflammation and extracellular matrix remodeling, while RANBP1 was involved in cytoplasmic transport and cell cycle regulation. The abnormal expression and modification of these two proteins were closely related to the pathophysiological process of the disease. Immunoinfiltration analysis found the pathological process of AA were related to the infiltration of memory B cells, activated NK cells and CD8(+) T cells. Additonally, weighted gene co-expression network analysis (WGCNA) showed the organization of the arachnoid proteome into a network of 28 biologically meaningful modules of co-expressed proteins. Of these, 2 modules were positively correlated to AA phenotypes. This study shows a distinct proteomic landscape of AA and non-adhesive arachnoiditis (nAA). These findings also provide valuable insights into the molecular changes associated with potential mechanisms underlying AA.

Genetic Commonalities Between Metabolic Syndrome and Rheumatic Diseases Through Disease Interactome Modules.

This study aims to elucidate the potential genetic commonalities between metabolic syndrome (MetS) and rheumatic diseases through a disease interactome network, according to publicly available large-scale genome-wide association studies (GWAS). The analysis included linkage disequilibrium score regression analysis, cross trait meta-analysis and colocalisation analysis to identify common genetic overlap. Using modular partitioning, the network-based association between the two disease proteins in the protein-protein interaction set was divided and quantified. Clinical samples from public databases were used to confirm the mapped genes. Mendelian randomisation analyses were conducted using genetic instrumental variables for causal inference. MetS and rheumatoid arthritis (RA), ankylosing spondylitis (AS), systemic lupus erythematosus (SLE), Sjogren's syndrome (SS) and their primary module networks shared topological overlap and genetic correlation. Functional analysis highlighted the significance of these shared targets in processes such as a diverse array of metabolic pathways involving glucose, lipids, energy, protein transport, inflammatory response, autophagy and cytokine regulation, elucidating the pathways through which MetS intersects with rheumatic diseases. Causal associations were determined between MetS phenotypes and rheumatic diseases. The persistence of MetS effects on rheumatic diseases remained evident even after adjusting for alcohol consumption and smoking. We have highlighted specific genetic associations between MetS and rheumatic diseases. Several genes (e.g., PRRC2A, PSMB8, BAG6, GPSM3, PBX2, etc.) have been identified with molecular commonalities in MetS and RA, AS, SLE and SS, which may serve as potential targets for shared treatments.

Constructing Neuron-like Structured NiS2/MOF Composites with Enhanced Regulation of Electron Transport and Active Sites for Oxygen Evolution.

Constructing fast electron transfer pathways and abundant electro-active sites is an effective strategy to improve the oxygen evolution reaction (OER) performance of catalysts. Herein, structural engineering and dual-phase engineering were employed to construct a NiS2 nanoparticle-encapsulated MOF configured with a pseudo-neuronal structure (NiS2/MOF/HT). It was found that the pseudo-neuronal structure, constructed with a carbon nanohorn (CNH) and carbon nanotube (CNT), provided fast electron transfer pathways and abundant exposed active sites. Moreover, the NiS2/MOF/HT composite obtained via partial vulcanization not only inherited the pseudo-neuronal structure but also prevented the aggregation and growth of NiS2 particles. NiS2/MOF composites provide various active sites. With the combination of the promotion of electronic transfer and enrichment of electro-active sites (NiS2, MOF), NiS2/MOF/HT showed excellent performance, whose overpotential at 25 mA cm-2 was reduced by 19.5% compared with MOF/HT.

FXYD1 was identified as a hub gene in recurrent miscarriage and involved in decidualization via regulating Na/K-ATPase activity.

Recurrent miscarriage (RM) is a distressing and complicated adverse pregnancy outcome. It is commonly recognized that insufficient decidualization could result in RM, but the molecular mechanisms of decidual impairment are still not fully understood. Thus, this study aimed to identify novel key genes potentially involved in RM and explore their roles played in endometrial decidualization. Initially, a combinative analysis of decidual and mid-secretory endometrial transcriptomes was performed to discover hub genes involved in the etiology of RM. And the expression levels of hub genes were evaluated in both primary decidual stromal cells (DSCs) and decidual tissues. Subsequently, the immortalized human endometrial cell line, T-HESCs, was used to investigate whether FXYD1 overexpression affects decidualization by regulating Na/K-ATPase activity. FXYD domain containing ion transport regulator 1 (FXYD1) was identified as a hub gene in the pathogenesis of RM through various bioinformatic methods. Abnormally increased FXYD1 expression was observed in DSCs and decidual tissues from RM patients compared to that of the normal group. Furthermore, in vitro decidualization was obviously inhibited by the overexpression of FXYD1. Additionally, Na/K-ATPase activity was significantly elevated during decidualization, whereas overexpression of FXYD1 reduced Na/K-ATPase activity. Bufalin, a Na/K-ATPase inhibitor, showed an effectively inhibitory effect on decidualization. Collectively, FXYD1 was discovered as a hub gene associated with RM, and its expression levels in RM patients were significantly upregulated. Increased FXYD1 expression might lead to decidualization defects by reducing Na/K-ATPase activity, of which presented a novel prospective treatment target for RM.

Exploring Aquaporins in Human Studies: Mechanisms and Therapeutic Potential in Critical Illness.

Aquaporins (AQPs) are membrane proteins facilitating water and other small solutes to be transported across cell membranes. They are crucial in maintaining cellular homeostasis by regulating water permeability in various tissues. Moreover, they regulate cell migration, signaling pathways, inflammation, tumor growth, and metastasis. In critically ill patients, such as trauma, sepsis, and patients with acute respiratory distress syndrome (ARDS), which are frequently encountered in intensive care units (ICUs), water transport regulation is crucial for maintaining homeostasis, as dysregulation can lead to edema or dehydration, with the latter also implicating hemodynamic compromise. Indeed, AQPs are involved in fluid transport in various organs, including the lungs, kidneys, and brain, where their dysfunction can exacerbate conditions like ARDS, acute kidney injury (AKI), or cerebral edema. In this review, we discuss the implication of AQPs in the clinical entities frequently encountered in ICUs, such as systemic inflammation and sepsis, ARDS, AKI, and brain edema due to different types of primary brain injury from a clinical perspective. Current and possible future therapeutic implications are also considered.

Dementia with lewy bodies patients with high tau levels display unique proteome profiles

BackgroundClinical studies have long observed that neurodegenerative disorders display a range of symptoms and pathological features and, in some cases, overlap, suggesting that these diseases exist on a spectrum. Dementia with Lewy Bodies (DLB), a synucleinopathy, is a prominent example, where symptomatic similarities with tauopathy, Alzheimer’s disease, are observed. Although tau pathology has been observed in DLB, the interplay between tau and α-synuclein is poorly understood at a molecular level.MethodsQuantitative mass spectrometry analysis was used to measure protein abundance in the insoluble fraction from cortical brain tissue from pathologically diagnosed DLB subjects (n = 30) and age-matched controls (n = 29). Using tau abundance, we stratified the DLB subjects into two subgroups termed DLBTau+ (higher abundance) and DLBTau− (lower abundance). We conducted proteomic analysis to characterize and compare the cortical proteome of DLB subjects exhibiting elevated tau, as well as the molecular modifications of tau and α-synuclein to explore the dynamic between tau and α-synuclein pathology in these patients.ResultsProteomic analyses revealed distinct global protein dysregulations in DLBTau+ and DLBTau− subjects when compared to controls. Notably, DLBTau+ patients exhibited increased levels of tau, along with ubiquitin, and APOE, indicative of cortical proteome alterations associated with elevated tau. Comparing DLBTau+ and DLBTau− groups, we observed significant upregulation of cytokine signaling and metabolic pathways in DLBTau− patients, while DLBTau+ subjects showed increases in protein ubiquitination processes and regulation of vesicle-mediated transport. Additionally, we examined the post-translational modification patterns of tau and α-synuclein. Our analysis revealed distinct phosphorylation and ubiquitination sites on α-synuclein between groups. Moreover, we observed increased modifications on tau specifically within the DLBTau+ subgroup.ConclusionThis molecular-level data supports the idea of neurodegenerative disease as a continuum of diseases with distinct PTM profiles DLBTau+ and DLBTau− patients in comparison to AD. These findings further emphasize the importance of identifying specific and tailored therapeutic approaches targeting the involved proteopathies in the neurodegenerative disease spectrum.

LEGAL UNCERTAINTY IN DIGITAL APPLICATION-BASED TRANSPORTATION SERVICES

The rise of app-based transportation services has led to a shift in lifestyle from conventional to online, from shopping needs to public transportation orders and various other services. The study aimed to explore the legal uncertainty that currently exists in the regulation of apps-based transport services, as well as the barriers and efforts to create legal certainty in this context. This study analyzed the data through a qualitative approach, employing a combination of legal analysis and comparative methods. The results show that the lack of clear regulations regarding the use of two-wheeled vehicles as public transport creates significant weaknesses within the industry. The lack of fair competition principles in Indonesia is an important concern in the context of transportation regulation. This work provides valuable insights for policymakers, regulators, and stakeholders involved in the transportation sector, suggesting pathways for improving regulatory clarity and effectiveness. By analyzing these areas, future research could contribute valuable insights to aid policymakers in creating a more coherent, effective, and responsive regulatory environment that supports the sustainable growth of the app based transportation sector while ensuring the safety and protection of all parties involved. This research could include comparative analyses of successful regulatory models from other jurisdictions that have effectively harmonized their regulations while fostering innovation and consumer protection.

The tariff regulation of railway freight transportation in EU

The article examines the provisions of the EU legislation on the tariff regulation of rail freight transportation, as well as the prospects of their implementation in the domestic system of industry regulation. It is emphasized that the implementation of European rules of tariff regulation on railway transport is an important factor in the development of a competitive environment in the market of transport services, as well as a necessary prerequisite for the attraction of internal and external investments in the development of the railway industry. Such adaptation is extremely important for reducing transport costs, improving the quality of services and the overall efficiency of rail freight transportation. The key provisions of the Directive of the European Parliament and the Council of Europe of 21.11.2012 № 2001/14/EU “Creation of a single European railway space”, which defines the rules for collecting fees for the use of railway infrastructure by freight transport operators, are highlighted. It is emphasized that the Directive envisages the separation of infrastructure management and transport operations to prevent conflicts of interest and stimulate fair competition among market operators. It also defines railway companies’ rights to access infrastructure and establishes transparent pricing mechanisms. The article examines the European experience of creating independent regulatory bodies authorized to monitor market practices, monitor compliance with safety standards, and ensure fair pricing mechanisms. It was concluded that the implementation of the provisions of the EU legislation on the tariff regulation of rail freight transportation will ensure a significant increase in the competitiveness of domestic rail transport by improving the access of national carriers to the European transport infrastructure, optimizing logistics on rail transport, ensuring transparency and reasonableness of pricing, creating equal conditions for national railway operators. The importance of the consistent implementation of the provisions of the EU legislation on the tariff regulation of rail freight transportation in the context of the Europeanization of domestic legislation on rail transport and the regulatory approximation provided for by the Association Agreement between Ukraine and the EU is emphasized.

Salt Stress and its Implications in Vegetable Crops with Special Reference to the Cucurbitaceae Family

Salt stress is a significant abiotic factor that constrains agricultural productivity by impairing plant growth, particularly in arid and semi-arid regions. Vegetables, ranging from sensitive to moderately tolerant to salinity, experience adverse effects such as disruptions in seed germination, growth, flowering, and fruit development. Salinity hampers water uptake from the soil, as higher salt concentrations in the root zone increase the energy required by plants to absorb water. Sodium salts, in particular, interfere with the uptake of essential nutrients like nitrogen, phosphorus, and potassium, leading to nutritional imbalances. Furthermore, salinity induces oxidative and osmotic stress, ion toxicity, and hormonal disturbances, while also heightening plants‘ susceptibility to diseases. Crops in the Cucurbitaceae family, such as Cucumis sativus (cucumber) and Citrullus lanatus (watermelon), are known to exhibit diverse physiological and biochemical strategies to cope with salinity, including efficient ion transport regulation, osmolyte production, and antioxidant activity. Crops in the Cucurbitaceae family, such as Cucumis sativus (cucumber) and Citrullus lanatus (watermelon), exhibit diverse physiological strategies to cope with salinity. These traits are critical due to their economic significance in global agriculture. Understanding these mechanisms is crucial due to the economic significance of this family in global agriculture. This review examines the effects of salt stress on plant growth and development, explores tolerance mechanisms, and highlights the potential of crops from the Cucurbitaceae family to contribute to sustainable agricultural practices.

Human transporter de-oligomerization regulates copper uptake into cells.

Copper is an essential element involved in various biochemical processes, such as mitochondrial energy production and antioxidant defense, but improper regulation can lead to cellular toxicity and disease. Copper Transporter 1 (CTR1) plays a key role in copper uptake and maintaining cellular copper homeostasis. Although CTR1 endocytosis was previously thought to reduce copper uptake when levels are high, it was unclear how rapid regulation is achieved. Using single-molecule localization microscopy and single-molecule neighbor density assays, we discovered that excess copper induces monomerization of the wild-type trimeric CTR1 prior to endocytosis, a response blocked in the endocytosis-deficient CTR1 (M150L) mutant. This monomerization rapidly halts copper uptake and prevents copper overload. These findings reveal changes in protein oligomerization as a new paradigm of metal transport regulation, linking CTR1's structural changes to its endocytosis and copper homeostasis.