Membrane Function Research Articles

The role and mechanism of “eight famous herbals in Zhejiang” in cancer via network pharmacology and experimental validation

In recent years, some components and active ingredients from the herbal formula “eight famous herbals in Zhejiang” (Zhe-Ba-Wei) have been reported to possess antitumor properties. However, there is still no systemic study on the role and mechanism of Zhe-Ba-Wei in cancer. To systematically investigate the anticancer efficacy of Zhe-Ba-Wei, we first identified 16 reported active ingredients with gene targets associated with various types of tumors. Second, we screened these active ingredients and their responding multiple shared targets by analyzing the convergence of diverse and tumor-specific target sites and identified four crucial active ingredients (ferulic acid, quercetin, rutin, luteolin), which were characterized by 27 overlapping gene targets. Third, these 27 gene targets were subsequently mapped onto the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and Gene Ontology term, and among the 27 total potential targets, 12 were involved in plasma membrane function. Fourth, we investigated the binding affinities between the four crucial active ingredients and their potential targets such as EGFR and MET, both of which are well-known oncogenes in various cancers. Subsequently, an investigation of the computational ADMET properties showed that most of these four ingredients exhibited good ADMET properties. Finally, we found that three active ingredients (ferulic acid, luteolin, and quercetin) could inhibit the proliferation of NSCLC cells and decrease the protein expression of EGFR in a concentration-dependent manner. All these results shed light on the bioactive components, pharmacological effects, and drug development and utilization of Zhe-Ba-Wei, aiming to provide useful support for its further research and clinical application.

A physical perspective on lithium therapy.

Lithium salts have strong medical properties in neurological disorders such as bipolar disorder and lithium-responsive headaches (Pereira da Silva Neto and James Almeida, 2010; Lindner et al., 2023; Silva-Néto et al., 2019). They have recently gathered attention due to their potential preventive effect in viral infections (Ferensztajn-Rochowiak and Rybakowski, 2023; Rybakowski, 2022). Though the therapeutic effect of lithium was documented by Cade in the late 1940s, its underlying mechanism of action is still disputed (Malhi and Outhred, 2016). Acute lithium exposure has an activating effect on excitable organic tissue and organisms, and is highly toxic (Schou, 1957; Butler-Munro et al., 2010; Izsak et al., 2021; Yip and Yeung, 2007). Lithium exposure is associated with a strong metabolic response in the organism, with large changes in phospholipid and cholesterol expression (López-Corcuera et al., 1988; Pettegrew et al., 2001; Aliyazicioğlu et al., 2007). Opposite to acute exposure, this metabolic response alleviates excessive cellular activity (Mertens et al., 2015; Stern et al., 2018; Santos et al., 2021). The presence of lithium ions strongly affects lipid conformation and membrane phase unlike other alkali ions (Hauser and Shipley, 1983), with consequences for membrane permeability, buffer property and excitability. This review investigates how lithium ions affect lipid membrane composition and function, and how lithium response might in fact be the body's attempt to counteract the physical presence of lithium ions at cell level. Ideas for further research in microbiology and drug development are discussed.

Phospholipid dynamics in Aspergillus species: relations between biological membrane composition and cellular morphology.

Biological membranes, primarily composed of phospholipid bilayers, are essential structures that compartmentalize the cell from the extracellular environment. The biosynthesis and regulation of membrane lipids have been extensively studied in model organisms such as Saccharomyces cerevisiae and mammalian cells. However, our understanding of biological membrane regulation in filamentous fungi, some of which are significant in medicine, pharmacy, and agriculture, remains limited. This minireview provides a comprehensive overview of the latest knowledge, focusing on filamentous fungi of Aspergillus species. Recent progress in understanding dynamic changes in membrane lipid profiles, driven by improvements in analytical techniques for lipidomics, is also presented. Furthermore, known that the cell morphology of filamentous fungi is closely linked to its harmful and beneficial characteristics, the influence of membrane composition on cell morphology is discussed. The integration of these findings will further enhance our understanding of the biological functions of membranes in filamentous fungi.

Inorganic Salt Solution-Based Aerosols for Fabricating Honeycomb-Patterned Porous Membranes.

Porous membranes with uniform pore sizes have shown potential applications. Although the breath figure method is renowned for its simplicity, it requires high humidity conditions, presenting challenges in energy consumption and safety, especially in arid climates. This study introduces an approach that uses inorganic salt-based aerosols to successfully fabricate honeycomb-patterned porous membranes at low humidity levels, where pure water vapor cannot produce such structures. Sodium chloride and ferric chloride solutions were used to successfully prepare membranes with pore sizes of ∼5.0 and 1.0 μm, respectively, at a relative humidity of 30%, which effectively separated microspheres of different sizes. The κ-Köhler theory and theories related to bubble bursting mechanisms and aerosols were used to preliminarily analyze the relation between inorganic salt aerosol generation and pore size, demonstrating that an increased NaCl concentration results in small pores. Additionally, potassium chloride and calcium chloride were found to have varying effects on pore size. These findings suggest that aerosols could enhance the applicability of the breath figure method and optimize membrane structures and functionality, thereby achieving broader applications in different fields.

Aminolipids in bacterial membranes and the natural environment.

Our comprehension of membrane function has predominantly advanced through research on glycerophospholipids, also known as phosphoglycerides, which are glycerol phosphate-based lipids found across all three domains of life. However, in bacteria, a perplexing group of lipids distinct from glycerol phosphate-based ones also exists. These are amino acid-containing lipids that form an amide bond between an amino acid and a fatty acid. Subsequently, a second fatty acid becomes linked, often via the 3-hydroxy group on the first fatty acid. These amide-linked aminolipids have, as of now, been exclusively identified in bacteria. Several hydrophilic head groups have been discovered in these aminolipids including ornithine, glutamine, glycine, lysine, and more recently, a sulfur-containing non-proteinogenic amino acid cysteinolic acid. Here, we aim to review current advances in the genetics, biochemistry and function of these aminolipids as well as giving an ecological perspective. We provide evidence for their potential significance in the ecophysiology of all major microbiomes i.e. gut, soil and aquatic as well as highlighting their important roles in influencing biological interactions.

A tuneable minimal cell membrane reveals that two lipid species suffice for life

All cells are encapsulated by a lipid membrane that facilitates their interactions with the environment. How cells manage diverse mixtures of lipids, which dictate membrane property and function, is experimentally challenging to address. Here, we present an approach to tune and minimize membrane lipid composition in the bacterium Mycoplasma mycoides and its derived ‘minimal cell’ (JCVI-Syn3A), revealing that a two-component lipidome can support life. Systematic reintroduction of phospholipids with different features demonstrates that acyl chain diversity is more important for growth than head group diversity. By tuning lipid chirality, we explore the lipid divide between Archaea and the rest of life, showing that ancestral lipidomes could have been heterochiral. However, in these simple organisms, heterochirality leads to impaired cellular fitness. Thus, our approach offers a tunable minimal membrane system to explore the fundamental lipidomic requirements for life, thereby extending the concept of minimal life from the genome to the lipidome.

Crystallographic insights into lipid-membrane protein interactions in microbial rhodopsins

The primary goal of our work is to provide structural insights into the influence of the hydrophobic lipid environment on the membrane proteins (MPs) structure and function. Our work will not cover the well-studied hydrophobic mismatch between the lipid bilayer and MPs. Instead, we will focus on the less-studied direct molecular interactions of lipids with the hydrophobic surfaces of MPs. To visualize the first layer of amphiphiles surrounding MPs and analyze their interaction with the proteins, we use the available highest-quality crystallographic structures of microbial rhodopsins. The results of the structure-based analysis allowed us to formulate the hypothetical concept of the role of the nearest layer of the lipids as an integral part of the MPs that are important for their structure and function. We then discuss how the lipid-MPs interaction is influenced by exogenous hydrophobic molecules, noble gases, which can compete with lipids for the surface of MPs and can be used in the systematic approach to verify the proposed concept experimentally. Finally, we raise the problems of currently available structural data that should be overcome to obtain a more profound picture of the lipid-MP interactions.

Impact of Peritoneal Neutrophil Extracellular Traps on Peritoneal Characteristics and Technical Failure in Patients Undergoing Peritoneal Dialysis.

Peritoneal dialysis (PD) is an effective home therapy for end-stage kidney disease. However, continuous exposure to PD fluids with high glucose concentration and recurrent peritonitis may lead to the activation of cellular and molecular processes of peritoneal damage, including inflammation and fibrosis. In particular, recent studies have highlighted the role of neutrophils in chronic inflammation. This study explores how neutrophil extracellular traps (NETs) affect peritoneal membrane function and contribute to technical failures in PD patients. We conducted a prospective observational study involving 250 non-infectious and 30 acute peritonitis patients. NETs were measured using nucleosome and myeloperoxidase DNA levels in PD fluids. Monocyte chemoattractant protein-1 (MCP-1) and matrix metalloproteinase-8 (MMP-8) were also measured to assess peritoneal inflammation and damage. A significant increase in peritoneal NETs, as determined by nucleosome and myeloperoxidase DNA levels, was observed in patients with acute peritonitis compared to patients without peritonitis. Even in non-infectious samples, NET levels were widely distributed and closely correlated with levels of MCP-1 and MMP-8. Higher levels of peritoneal NETs were closely associated with increased 4-hour dialysate/peritoneal (D/P) creatinine ratio and 1-hour D/P sodium levels, indicating a higher prevalence of fast transport and limited free water transport. These factors were associated with a higher risk of technical failure. During a mean follow-up of 34 months, 39.2% (98 patients) switched from PD to hemodialysis, with higher NET levels significantly increasing the risk by 1.9 times (95% confidence interval 1.27-2.83, p=0.020). This study suggests the importance of peritoneal NETs not only as markers of acute inflammation but also as significant immunological predictors of chronic peritoneal membrane inflammation and dysfunction, and as potential risk factors for technical failure.

Metabolic abnormalities and reprogramming in cats with naturally occurring hypertrophic cardiomyopathy.

The heart is a metabolic organ rich in mitochondria. The failing heart reprograms to utilize different energy substrates, which increase its oxygen consumption. These adaptive changes contribute to increased oxidative stress. Hypertrophic cardiomyopathy (HCM) is a common heart condition, affecting approximately 15% of the general cat population. Feline HCM shares phenotypical and genotypical similarities with human HCM, but the disease mechanisms for both species are incompletely understood. Our goal was to characterize global changes in metabolome between healthy control cats and cats with different stages of HCM. Serum samples from 83 cats, the majority (70/83) of which were domestic shorthair and included 23 healthy control cats, 31 and 12 preclinical cats with American College of Veterinary Internal Medicine (ACVIM) stages B1 and B2, respectively, and 17 cats with history of clinical heart failure or arterial thromboembolism (ACVIM stage C), were collected for untargeted metabolomic analysis. Multiple linear regression adjusted for age, sex and body weight was applied to compare between control and across HCM groups. Our study identified 1253 metabolites, of which 983 metabolites had known identities. Statistical analysis identified 167 metabolites that were significantly different among groups (adjusted P<0.1). About half of the differentially identified metabolites were lipids, including glycerophospholipids, sphingolipids and cholesterol. Serum concentrations of free fatty acids, 3-hydroxy fatty acids and acylcarnitines were increased in HCM groups compared with control group. The levels of creatine phosphate and multiple Krebs cycle intermediates, including succinate, aconitate and α-ketoglutarate, also accumulated in the circulation of HCM cats. In addition, serum levels of nicotinamide and tryptophan, precursors for de novo NAD+ biosynthesis, were reduced in HCM groups versus control group. Glutathione metabolism was altered. Serum levels of cystine, the oxidized form of cysteine and cysteine-glutathione disulfide, were elevated in the HCM groups, indicative of heightened oxidative stress. Further, the level of ophthalmate, an endogenous glutathione analog and competitive inhibitor, was increased by more than twofold in HCM groups versus control group. Finally, several uremic toxins, including guanidino compounds and protein bound putrescine, accumulated in the circulation of HCM cats. Our study provided evidence of deranged energy metabolism, altered glutathione homeostasis and impaired renal uremic toxin excretion. Altered lipid metabolism suggested perturbed structure and function of cardiac sarcolemma membrane and lipid signalling.

Walnut Consumption May Contribute to Healthy Cardiovascular/Endothelial Function by Maintaining Membrane Integrity

Cardiovascular diseases (CVDs) are the leading causes of death worldwide. A healthy diet has an important role in delaying the development of many modifiable risk factors of CVD, including abdominal obesity, high blood pressure, high plasma levels of cholesterol, and glucose. The consumption of various nuts, especially walnuts, may benefit both primary and secondary prevention due to their bioactive components. This review focuses on (1) the protective role of walnut consumption on CVD at large (2) and the potential cellular and molecular mechanisms by which they have beneficial effects on vascular endothelial function. Walnuts contain many essential ingredients (such as polyunsaturated fatty acids, phenolic compounds, and vitamin E) necessary for the healthy functioning of membranes. Since membranes are involved in nearly all processes associated with life-related function, the main underlying mechanism of walnut-improved cardiovascular function is likely based on improving membrane composition and function by providing all of the substrates necessary for membranes, such as cell, mitochondria, Golgi, nucleus, and so on. In addition to endothelial cell function, all other cells and membranes are likely to benefit from walnut consumption, suggesting that incorporating walnuts into the human diet is essential, for example, during higher physical and mental demand, such as exercise, and may mitigate the risk for the development of cardiovascular diseases and compensate for the sedentary lifestyle, especially in those of an older age.

Mechanisms of lipid-mediated regulation of the pore-forming activity of antimicrobial agents: studies on planar lipid bilayers

Planar lipid bilayers are unique tools designed for modeling cell membranes and electrophysiological studies of incorporated ion channels. Such model systems are designed to limit the number of components taking part in the functioning of biological membranes in order to characterize in detail the occurring processes under well-controlled experimental conditions. Planar lipid bilayers make it possible to record single events with a measured current of more than a tenth of a picoampere. The relative simplicity of the method, the ability to observe single molecular events, and the high reproducibility of the results obtained determines the unprecedented effectiveness of using planar lipid bilayers to identify key physical and chemical factors responsible for regulating the functioning of ion channels. This review represents an analysis of literature data concerning the mechanisms of lipid-associated regulation of ion channels formed by various antimicrobial agents. The examination allows us to consider the lipids as molecular chaperones that ensure the formation of pores in target membranes by antimicrobials.

Definition of phosphatidylinositol 4,5-bisphosphate distribution by freeze-fracture replica labeling.

Phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] is a phospholipid essential for plasma membrane functions, but its two-dimensional distribution is not clear. Here, we compared the result of sodium dodecyl sulfate-treated freeze-fracture replica labeling (SDS-FRL) of quick-frozen cells with the actual PtdIns(4,5)P2 content and the results obtained by fluorescence biosensor and by labeling of chemically-fixed membranes. In yeast, enrichment of PtdIns(4,5)P2 in the membrane compartment of Can1 (MCC)/eisosome, especially in the curved MCC/eisosome, was evident by SDS-FRL, but not by fluorescence biosensor, GFP-PLC1δ-PH. PtdIns(4,5)P2 remaining after acute ATP depletion and in the stationary phase, 30.0% and 56.6% of the control level, respectively, was not detectable by fluorescence biosensor, whereas the label intensity by SDS-FRL reflected the PtdIns(4,5)P2 amount. In PC12 cells, PtdIns(4,5)P2 was observed in a punctate pattern in the formaldehyde-fixed plasma membrane, whereas it was distributed randomly by SDS-FRL and showed clustering after formaldehyde fixation. The results indicate that the distribution of PtdIns(4,5)P2 can be defined most reliably by SDS-FRL of quick-frozen cells.

Relationship between Macular Microvasculature and Visual Function in Idiopathic Macular Epiretinal Membrane by Using OCT Angiography and Multifocal Electroretinogram

Relationship between Macular Microvasculature and Visual Function in Idiopathic Macular Epiretinal Membrane by Using OCT Angiography and Multifocal Electroretinogram

Localization of proteins involved in the biogenesis and repair of the photosynthetic apparatus to thylakoid subdomains in Arabidopsis.

Thylakoid membranes in chloroplasts and cyanobacteria harbor the multisubunit protein complexes that catalyze the light reactions of photosynthesis. In plant chloroplasts, the thylakoid membrane system comprises a highly organized network with several subcompartments that differ in composition and morphology: grana stacks, unstacked stromal lamellae, and grana margins at the interface between stacked and unstacked regions. The localization of components of the photosynthetic apparatus among these subcompartments has been well characterized. However, less is known about the localization of proteins involved in the biogenesis and repair of the photosynthetic apparatus, the partitioning of proteins between two recently resolved components of the traditional margin fraction (refined margins and curvature), and the effects of light on these features. In this study, we analyzed the partitioning of numerous thylakoid biogenesis and repair factors among grana, curvature, refined margin, and stromal lamellae fractions of Arabidopsis thylakoid membranes, comparing the results from illuminated and dark-adapted plants. Several proteins previously shown to localize to a margin fraction partitioned in varying ways among the resolved curvature and refined margin fractions. For example, the ALB3 insertase and FtsH protease involved in photosystem II (PSII) repair were concentrated in the refined margin fraction, whereas TAT translocon subunits and proteins involved in early steps in photosystem assembly were concentrated in the curvature fraction. By contrast, two photosystem assembly factors that facilitate late assembly steps were depleted from the curvature fraction. The enrichment of the PSII subunit OE23/PsbP in the curvature fraction set it apart from other PSII subunits, supporting the previous conjecture that OE23/PsbP assists in PSII biogenesis and/or repair. The PSII assembly factor PAM68 partitioned differently among thylakoid fractions from dark-adapted plants and illuminated plants and was the only analyzed protein to convincingly do so. These results demonstrate an unanticipated spatial heterogeneity of photosystem biogenesis and repair functions in thylakoid membranes and reveal the curvature fraction to be a focal point of early photosystem biogenesis.

Psr1 phosphatase regulates pre-mRNA splicing through spliceosomal B complex factor Snu66.

Regulated precursor messenger RNA (pre-mRNA) splicing modulates gene expression and promotes alternative splicing. The process is regulated by modifications of spliceosomal proteins and small nuclear RNAs (snRNAs). Here, we show that the protein phosphatase Psr1, known for its plasma membrane localisation and function in general stress response in Saccharomyces cerevisiae, also plays a regulatory role in pre-mRNA splicing. Independently of its presence at the plasma membrane, Psr1 binds and dephosphorylates the core splicing factor Snu66. The enzyme is not an integral component of the spliceosome. Psr1 deletion in yeast, or tethering of its catalytic mutant to Snu66, results in splicing defects of introns with non-canonical 5' splice sites (ss). While the Psr1 binding site on Snu66 is distinct from the Hub1 interaction domains (HIND), Hub1 displaces Psr1 from Snu66. Thus, Psr1 phosphatase plays a regulatory role in pre-mRNA splicing by modulating Snu66 functions.

Integral Membrane Protein Degradation: A Novel Paradigm by PROTAC Technology

: Integral membrane proteins are attractive targets for therapeutic intervention due to their crucial roles in cellular functions and their involvement in various diseases. However, targeting these proteins for degradation has posed significant challenges due to their complex structures and diverse functions. The emergence of proteolysis-targeting chimeras (PROTAC) represents a groundbreaking paradigm shift in drug development, offering a novel approach to address the degradation of integral membrane proteins. This review explores the innovative application of PROTAC technology in inducing the degradation of integral membrane proteins. PROTACs are molecules that have two roles: they bring together specific target proteins and E3 ubiquitin ligases, which help with ubiquitination and the degradation of proteins by proteasomes. As PROTACs are made up of separate parts, they can be put together to make custom molecules that can target difficult targets, such as integral membrane proteins. This review covers recent developments and advancements in the design and optimisation of PROTACs tailored for integral membrane protein degradation. Furthermore, it also discusses the problems that come up when trying to target membrane proteins and how PROTACs solve these problems by using ligands that can pass cell membranes and specifically interact with target proteins. It delves into the potential therapeutic implications of degrading integral membrane proteins using PROTACs and elucidates the impact of this novel approach in treating diseases that involve aberrant membrane protein expression or function by highlighting specific examples and case studies.

Anethole improves mitochondrial activity and quality parameters in fresh and frozen-thawed ovine semen

Anethole, an antioxidant found in plants, appears to improve the survival of spermatozoa during semen cryopreservation. This study assessed the effects of commercial trans-anethole in ram semen cryopreservation. Thirty ejaculates from six rams were diluted in media containing anethole at the following concentrations: CONT (0 μM), AN10 (10 μM), AN50 (50 μM), and AN100 (100 μM). Semen was slow-frozen, preserved in liquid nitrogen, and thawed. Anethole at 10 μM or 50 μM did not compromise any studied sperm quality parameter but increased pre-freezing functionality of membrane and mitochondrial activity. At 10 μM, anethole reduced post-thawing spermatozoa lipoperoxidation. At 50 μM, anethole sustained higher mitochondrial activity after thawing, reduced minor defects in sperm, and increased the number of sperm binding to perivitelline membrane, while keeping lipoperoxidation levels as in control. Anethole at 100 μM promoted higher pre- and post-freezing mitochondrial activity and higher number of sperm binding to perivitelline membrane, in comparison to control. Additionally, some post-thawing kinematic parameters were enhanced by anethole at 100 μM. Of note, mitochondrial activity and lipoperoxidation were higher with anethole at 100 μM in comparison to 50 μM, not differing from control. At the hypoosmotic test, the highest concentration (100 μM) tested reduced sperm osmotic resistance. The results of this study indicate that using anethole in cryopreservation media promoted mostly positive effects on the fresh and post-thawed ram semen, and the advantages vary according to its concentration.

Improvement of Post-Thaw Quality and In Vivo Fertility of Simmental Bull Spermatozoa Using Ferulic Acid.

Artificial insemination and semen cryopreservation have significantly improved the quality and quantity of cattle production. Through cryopreserved semen and artificial insemination, top-breeding bull sperm can be used to inseminate thousands of cows worldwide. Our study aimed to determine the effect of adding ferulic acid (FA) to a Tris-based semen extender on frozen and thawed Simmental bull sperm. Semen samples were collected from three Simmental bulls. Pooled Simmental semen (n=34 ejaculations) were diluted with a Tris-base extender containing varying FA concentrations (0.1, 0.15, 0.25, 0.35, and 0.45mM). After the samples were frozen and thawed, the samples were tested for malondialdehyde (MDA), total antioxidant capacity (TAC), superoxide dismutase (SOD), glutathione peroxidase (GPx), total motility, progressive motility, motility characteristics, and plasma membrane functionality. The control and the groups with the best FA concentrations, 0.25 and 0.35, were compared for in vivo fertility. Fifty-one cows were inseminated 24h after the onset of oestrus. A rectal examination was used to diagnose pregnancies at least 60 days after fertilization. Results showed that adding FA-0.45, FA-0.35, FA-0.25, and FA-0.15 to the semen of Simmental bulls improved total and progressive motility, motility characteristics, and plasma membrane functionality. It also increased GPx and TAC levels, reducing MDA and DNA damage after freezing. The addition of FA did not affect SOD values. The fertility rate in the FA-0.25 and FA-0.35 groups was higher than in the control group, 35.29%, with rates of 76.47% and 70.58%, respectively. In conclusion, adding FA (0.15, 0.25, 0.35, and 0.45mM) to Tris-based semen extenders can improve the quality parameters of cryopreserved Simmental bull semen and increase in vivo fertility using 0.25 and 0.35 concentrations of FA.

Encoding extracellular modification of artificial cell membranes using engineered self-translocating proteins

The development of artificial cells has led to fundamental insights into the functional processes of living cells while simultaneously paving the way for transformative applications in biotechnology and medicine. A common method of generating artificial cells is to encapsulate protein expression systems within lipid vesicles. However, to communicate with the external environment, protein translocation across lipid membranes must take place. In living cells, protein transport across membranes is achieved with the aid of complex translocase systems which are difficult to reconstitute into artificial cells. Thus, there is need for simple mechanisms by which proteins can be encoded and expressed inside synthetic compartments yet still be externally displayed. Here we present a genetically encodable membrane functionalization system based on mutants of pore-forming proteins. We modify the membrane translocating loop of α-hemolysin to translocate functional peptides up to 52 amino acids across lipid membranes. Full membrane translocation occurs in the absence of any translocase machinery and the translocated peptides are recognized by specific peptide-binding ligands on the opposing membrane side. Engineered hemolysins can be used for genetically programming artificial cells to display interacting peptide pairs, enabling their assembly into artificial tissue-like structures.

The Role of the Organic Moiety in the Diffusion and Transport of Carboxylates into Liposomes.

Understanding carboxylate transport through lipid membranes under physiological conditions is critical in biomedicine and biotechnology, as it allows for the emulation of biological membrane functions and can enhance the absorption of hydrophobic carboxylate-based drugs. However, the structural diversity of carboxylates has made it challenging to study their transport, and the limited available examples do not provide a comprehensive understanding of the role of the organic moiety in this process. Here, we present an in-depth analysis of the diffusion and transport of various aliphatic and aromatic carboxylates into liposomes. We assessed the influence of their size, number of carboxylate groups, and presence of hydroxyl groups. Our findings from fluorescence assays, using lucigenin and HPTS as probes, revealed that most carboxylates can spontaneously diffuse into liposomes in their protonated state, facilitated by the efflux of HNO3 when using NaNO3 solutions at pH 7. The Cl-ISE assay showed chloride/carboxylate exchange by a synthetic anion transporter. Clear trends were observed when the organic moiety was systematically varied, with a particular enhancement of anion transport by the presence of hydroxyl groups in the aromatic carboxylates. Our findings provide insights into the processes by which carboxylates can enter liposomes, which can contribute to understanding the transport of other biologically relevant organic anions.