bims-supasi 2026-01-25 papers

bims-supasi

Biomed News

on Sulfation pathways and signalling

Issue of 2026–01–25
thirteen papers selected by
Jonathan Wolf Mueller, University of Birmingham

Relationship of body composition with cortisol and dehydroepiandrosterone sulfate levels in Korean men and women.
A Native-MS Study of Charge-Driven Interactions of Glycosaminoglycans with Lactoferrin Underlying Its Immunoprotective and Immunomodulatory Properties.
A sulfotransferase from a gut microbe acts on diverse phenolic sulfate compounds, including acetaminophen sulfate.
Epithelial Heparan Sulfate Promotes Staphylococcus aureus Corneal Infection by Inhibiting Cathelicidins.
TPST2-mediated tyrosine sulfation orchestrates porcine preimplantation development.
Dual-targeting liposomal delivery of sorafenib and docetaxel for enhanced synergistic therapy in advanced hepatocellular carcinoma.
Cortisol-to-DHEAS awakening response ratio in people with dementia and family caregivers: Associations with age, dementia severity and agitation.
Evidence for precursors of norandrogens as 3-enol sulfates from porcine Leydig cell incubations.
Biomimetic Formation and Tuning of a Cell Surface Heparan Sulfate Network: Approach on Deciphering the Glycosaminoglycans Code.
MARCHF1-mediated SULF1 degradation blocks THBS2/TGF-β/SMAD2/3 signaling to reverse colon cancer metastasis and 5-FU resistance.
Discovery and engineering of chicken sulfotransferase SULT1B1 from Bambusicola thoracicus.
Astaxanthin activates the Nrf2/HO-1 pathway to attenuate indoxyl sulfate-induced oxidative stress and DNA damage in renal tubular epithelial cells.
Strategies of AAV capsid engineering for targeted delivery to brain, muscle, and retina.

J Int Med Res. 2026 Jan;54(1): 3000605251413389

Relationship of body composition with cortisol and dehydroepiandrosterone sulfate levels in Korean men and women.

Sat Byul Park.

  BackgroundGlucocorticoids, primarily cortisol, mediated by the hypothalamic-pituitary-adrenal axis, significantly influence metabolic responses, including insulin resistance, lipolysis, and body fat distribution. Dehydroepiandrosterone sulfate, an adrenal androgen precursor, often counteracts some of cortisol's metabolic effects. An imbalance between these hormones is hypothesized to impact body composition. This study aimed to investigate the relationship between cortisol and dehydroepiandrosterone sulfate levels, their ratio, and body composition in a Korean population.MethodsIn total, 802 Korean adults participated in this study between 2018 and 2023. Data on sociodemographic and lifestyle factors, body composition, blood pressure, and metabolic variables were assessed. Cortisol and dehydroepiandrosterone sulfate levels were measured and analyzed using partial correlation and multiple logistic regression, adjusting for age, sex, and other relevant confounders, to determine their relationship with body composition.ResultsCortisol levels were negatively correlated with body weight, waist circumference, and body mass index after adjustment, and this correlation was more significant in women than in men. Dehydroepiandrosterone sulfate levels showed positive correlations with height, body weight, and waist circumference. The cortisol/dehydroepiandrosterone sulfate ratio demonstrated a negative association with height and body weight. Logistic regression analysis revealed that elevated cortisol levels and a high cortisol/dehydroepiandrosterone sulfate ratio were significant positive predictors of central obesity in men.ConclusionsElevated cortisol levels are associated with lower adiposity, particularly in women. Dehydroepiandrosterone sulfate levels are positively correlated with height and body mass. The prediction of central obesity is positively associated with cortisol levels and the cortisol/dehydroepiandrosterone sulfate ratio in men and negatively associated with dehydroepiandrosterone sulfate levels.

Keywords:  Cortisol; body composition; central obesity; cortisol/dehydroepiandrosterone sulfate ratio; dehydroepiandrosterone sulfate

DOI:  https://doi.org/10.1177/03000605251413389
J Am Soc Mass Spectrom. 2026 Jan 20.

A Native-MS Study of Charge-Driven Interactions of Glycosaminoglycans with Lactoferrin Underlying Its Immunoprotective and Immunomodulatory Properties.

Ruolan Cheng, Daniil G Ivanov, Yi Du, Igor A Kaltashov.

Apart from its role as a nutrient in mammalian milk, lactoferrin (LF) is also an important part of the innate immune system, where it functions as a potent microbicidal molecular factor. An important structural feature of LF, which makes it distinct from its next-of-kin serum transferrin (TF, an iron transporter that is not involved in the innate immune response), is the presence of an extended patch of positive charge on the surface of LF. While the relevance of this structural feature to the protein's immunoprotective properties is indisputable, the specific molecular mechanism that governs its involvement in protection against a wide array of pathogens remains poorly understood. We use native mass spectrometry (MS) and molecular modeling to study LF interaction with glycosaminoglycans, whose structure approximates that of the highly sulfated segments of heparan sulfate (HS), a major component of the extracellular matrix. Even the shortest highly sulfated HS segments readily associate with LF under near-native conditions, suggesting that this interaction plays an important role in concentrating the microbicidal agent in the vicinity of the point of its release from the activated neutrophil, thereby preventing its removal from the infection site by diffusion or blood flow. No such properties are exhibited by TF, consistent with its role as an iron transporter that needs to be freely circulated until its encounter with a receptor on the surface of a cell that requires a supply of iron for its growth or specific function(s). We also examine the interaction of LF with heparin, a highly sulfated glycosaminoglycan that is released from the mast cells upon their activation. Native MS reveals the ability of a single heparin chain to accumulate a significant number of LF molecules (up to five), consistent with its proposed role as an antagonist of the heparin-associated tryptases (which are deactivated upon their dissociation from heparin). This provides a molecular basis for the immunomodulatory properties of LF as a factor limiting the harm to the host inflicted by tryptases in the course of the mast cells' coactivation with neutrophils.

DOI: https://doi.org/10.1021/jasms.5c00408
PNAS Nexus. 2026 Jan;5(1): pgaf403

A sulfotransferase from a gut microbe acts on diverse phenolic sulfate compounds, including acetaminophen sulfate.

Rylee Close, Schuyler Kremer, Madison Mitchem, Andrew Bellinghiere, Khemlal Nirmalkar, Chad R Borges, Rosa Krajmalnik-Brown, Dhara D Shah.

  Sulfonation is one of the two main phase II detoxification pathways in eukaryotes which transforms nonpolar compounds into hydrophilic metabolites. Sulfotransferases catalyze these reactions by transferring a sulfo group from a donor to an acceptor molecule. Human cytosolic sulfotransferases use only 3'-phosphoadenosine 5'-phosphosulfate (PAPS) as a donor to sulfonate a variety of chemicals. Less understood are microbial aryl-sulfate sulfotransferases (ASSTs), which catalyze sulfo transfer reactions, without utilizing PAPS as a donor. Currently, the identity of physiological sulfo donor substrates remains unknown and sulfo acceptor substrates are underexplored. With this study, we aim to understand the potential contribution of a gut microbial enzyme to sulfonation chemistry by uncovering its substrate preferences. Here, we show that a sulfotransferase (Bacteroides vulgatus ASST) from the prevalent gut microbe B. vulgatus (now Phocaeicola vulgatus) is a versatile catalyst that utilizes a wide range of phenolic molecules as substrates that are commonly encountered by the host. With this action, it modulates concentrations of donor phenolic sulfates such as acetaminophen sulfate, dopamine sulfate, p-cresol sulfate, and related compounds in vitro and displays broad acceptor flexibility by sulfonating diverse phenolic compounds, including p-coumaric acid, p-cresol, 4-ethylphenol, tyramine, among others. These findings suggest that gut microbial enzymes like ASSTs may contribute to host detoxification of phenolics, a role previously attributed solely to human sulfotransferases. However, further in vivo studies are necessary to understand the potential contributions of ASSTs to host detoxification processes.

Keywords:  acetaminophen; bacteroides; gut microbiome; p-cresol; sulfotransferase

DOI:  https://doi.org/10.1093/pnasnexus/pgaf403
Proteoglycan Res. 2025 Oct;pii: e70041. [Epub ahead of print]3(4):

Epithelial Heparan Sulfate Promotes Staphylococcus aureus Corneal Infection by Inhibiting Cathelicidins.

Kazutaka Hayashida, Jeffrey D Esko, Richard D Gallo, Jian Liu, Winston W-Y Kao, Pyong Woo Park.

  Cathelicidins are short cationic peptides with potent microbicidal activities and comprise an important arm of host innate immunity. Many cell types can produce cathelicidins, but they are mainly expressed by recruited immune cells and are induced in epithelial cells during infection. Although the mechanisms of bacterial killing by cathelicidins have been largely elucidated in vitro, those that regulate their activities in vivo are less well understood. Bacterial pathogens often co-opt host extracellular matrix (ECM) components and their functions to escape host defense; however, it is unclear whether such mechanisms exist against cathelicidins. Several studies have demonstrated that host heparan sulfate (HS) inhibits LL-37, the human cathelicidin, suggesting that bacteria might exploit HS to evade killing by cathelicidins. However, precisely how HS inhibits LL-37 and possibly other cathelicidins remains unknown, and the role of the HS-cathelicidin interaction in infectious disease has not been rigorously studied. Here, we found that deleting CRAMP, the murine cathelicidin, significantly increases the susceptibility of mice to Staphylococcus aureus corneal infection. We also determined that heparan compounds bind to CRAMP with low nanomolar affinity, the secondary structure of CRAMP is required for HS binding, and HS binding to CRAMP inhibits CRAMP binding to target bacterial cells. Furthermore, we found that heparan compounds inhibit the killing of S. aureus by cathelicidins derived from several mammalian species in a 2-O-sulfate-dependent manner. Additionally, we demonstrate for the first time that conditional deletion of HS2ST, the enzyme responsible for 2-O-sulfation of HS, in corneal epithelial cells significantly reduces the susceptibility of mice to corneal infection. Altogether, these data uncover an endogenous inhibition mechanism of cathelicidins where 2-O-sulfated epithelial HS tightly binds and neutralizes the antibacterial activity of cathelicidins.

Keywords:  Staphylococcus aureus; antimicrobial peptide; cathelicidin; glycosaminoglycan; heparan sulfate; host defense

DOI:  https://doi.org/10.1002/pgr2.70041
BMC Biol. 2026 Jan 22.

TPST2-mediated tyrosine sulfation orchestrates porcine preimplantation development.

Jiaze Gao, Chengpeng Wang, Hongshuang Xie, Guang Yang, Qingbo Yang, Cheng Huang, Shijie Li, Zhonghua Liu, Tianyao He, Zhi Yin, Jun-Xue Jin, Jiaqiang Wang.

   BACKGROUND: Tyrosine sulfation is a widespread posttranslational modification in mammals and is known to influence protein function and signaling. However, its functional significance during porcine preimplantation development remains poorly understood.
RESULTS: In this study, we demonstrate that TPST2-mediated tyrosine sulfation is critical for early porcine embryonic development. TPST2 is transcriptionally activated during zygotic genome activation by its antisense long noncoding RNA, termed aTPST2, which recruits MED4, a core subunit of the Mediator complex, to activate TPST2 transcription in cis. Mechanistically, TPST2 mediates sulfation at tyrosine 39 (Y39) of TTYH3, enhancing its protein stability. The stabilized TTYH3 interacts with RAP1B to activate MAPK signaling, thereby ensuring proper embryonic development.
CONCLUSIONS: Our findings elucidate a compelling molecular mechanism by which tyrosine sulfation orchestrates porcine preimplantation development. Together, these results provide new insights into the developmental functions of tyrosine sulfation.

Keywords:  LncRNA aTPST2 ; Porcine preimplantation development; Sulfated TTYH3; TPST2; Tyrosine sulfation

DOI:  https://doi.org/10.1186/s12915-026-02525-7
Pharm Sci Adv. 2024 Dec;2 100046

Dual-targeting liposomal delivery of sorafenib and docetaxel for enhanced synergistic therapy in advanced hepatocellular carcinoma.

Yawen Yao, Yue Hu, Xinwang Meng, Fenyan Feng, Feng Xu, Guangji Wang, Hua Yu, Juan Li.

  Patients with advanced hepatocellular carcinoma (HCC) are not sensitive to sorafenib (SOR), therefore, combination therapy is required. In this study, an improved thin-film dispersion and post-insertion anchoring technique was utilized to construct a dual-targeted co-delivery SOR and docetaxel (DTX) liposome drug delivery system, folate/chondroitin sulfate with SOR/DTX-modified liposomes (FA/CS@SDLP), to jointly enhance the anti-recurrence and metastasis of HCC. FA/CS@SDLP can establish the gradual release of the two drugs because of successful lysosomal escape in the condensed hyaluronidase environment. The results indicated that modification with folate (FA) and chondroitin sulfate (CS) significantly enhanced the cellular uptake of FA/CS@SDLP and the internalization of SOR/DTX in HepG2 cells through FA and CD44 receptor-mediated endocytosis. Compared to free drugs or the mono-targeted liposomal system (FA@SDLP), FA/CS@SDLP presented higher potency against HepG2 cells regarding pro-apoptosis, anti-proliferation, and anti-metastasis (migration and invasion). Moreover, a more satisfactory antitumor efficacy was observed for FA/CS@SDLP in the pulmonary metastasis of HCC in a mouse model. In summary, dual-targeted co-delivery of liposomes can synergistically treat HCC recurrence and metastasis, providing a new approach for the clinically accurate treatment of HCC.

Keywords:  Advanced hepatocellular carcinoma; Combination therapy; Docetaxel; Dual-targeting liposomes; Sorafenib

DOI:  https://doi.org/10.1016/j.pscia.2024.100046
Compr Psychoneuroendocrinol. 2026 Feb;25 100334

Cortisol-to-DHEAS awakening response ratio in people with dementia and family caregivers: Associations with age, dementia severity and agitation.

Wanrui Wei, Töres Theorell, Gabriella Engstrom, Azita Emami.

   Background: The ratio of cortisol to dehydroepiandrosterone sulfate (DHEAS) in the awakening response has emerged as a potential biomarker of stress-related dysregulation in neurodegenerative conditions. Whether this ratio differs between people with dementia (PWD) and family caregivers, and how it varies with age, sex, dementia severity and agitation, remains unclear.
Methods: We analyzed 1093 day-level saliva samples from 58 participants (PWD = 28; caregivers = 30). The primary outcome was the log-transformed awakening response ratio of cortisol to DHEAS. Linear mixed-effects models with a participant random intercept and natural splines for age estimated group contrasts as geometric mean ratios (GMRs) from estimated marginal means. Fixed-effect predictors included age, sex, dementia severity (Global Deterioration Scale, GDS), and agitation (Brief Agitation Rating Scale, BARS). Model comparisons were conducted. Within PWD, mean-centered models tested one interaction at a time (Sex × GDS, Sex × BARS, Age × GDS, Age × BARS).
Results: There was no between-group difference in the ratio after accounting for within-participant clustering and age (GMR = 0.97, 95 % CI 0.64-1.46; p = 0.87). Within PWD, interaction models indicated that the association between age and the ratio strengthened with higher dementia severity (β = 0.043, p = 0.04) and greater agitation (β = 0.011, p = 0.006). Marginal R2 ranged 0.114-0.141; conditional R2 0.358-0.376.
Conclusions: Although average ratio did not differ between PWD and caregivers, it increased more steeply with age at higher dementia severity and agitation. These findings highlight the cortisol-to-DHEA(S) awakening response ratio as a non-invasive and clinically relevant biomarker reflecting symptom-linked neuroendocrine heterogeneity in dementia.

Keywords:  Agitation; Awakening response; Cortisol; Dehydroepiandrosterone; Dementia; Saliva

DOI:  https://doi.org/10.1016/j.cpnec.2025.100334
Reproduction. 2026 Jan 15. pii: xaaf015. [Epub ahead of print]171(1):

Evidence for precursors of norandrogens as 3-enol sulfates from porcine Leydig cell incubations.

James I Raeside, Heather L Christie.

  Norandrogens are significant anabolic-androgenic steroids used initially for the treatment of debilitating conditions and later as performance-enhancing drugs. Regulatory challenges of their abuse in human, equine, and canine sports stem from the question of endogenous norandrogens. Evidence from mass spectrometry for 19-norandrostenedione (19-norA4) in the sulfate fraction of conjugated steroids in equine yolk-sac fluid suggested a need for reexamination. In vitro biosynthesis of 19-norandrogens was examined in highly purified preparations of porcine Leydig cells from mature pigs by incubation in -medium containing [3H]-androstenedione (A4) or nonradioactive A4. Steroids were recovered from media by solid-phase extraction, separately as unconjugated and conjugated fractions. High performance liquid chromatographic (HPLC) profiles were obtained from liquid-scintillaion counting of radioctivity. Several peaks in the conjugated fractions were investigated further by HPLC. Two peaks widely separated on HPLC as conjugated steroids yielded evidence of norandrostenedione (19-norA4) after solvolysis. Other peaks identified by HPLC retention times matching standards were 19-hydroxy-A4, A4 (substrate), and epiandrosterone. Incubations with non-radioactive A4 provided further evidence from radioimmunoassay of sulfated steroids as precursors of 19-norA4. With known high sulfotransferase activity in porcine Leydig cells, it is proposed that two 3-enol sulfates were formed as stable "precursors" of 19-norA4 by the distinctive action of the third aromatase isoform of the boar testes. Although their identities remain unknown, it was shown that 19-norA4 itself was not present as a 3-enol sulfate. These findings have implications regarding endogenous anabolic agents in normal growth and relevance to illegal use of anabolic androgens in sports and animal production.

Keywords:  anabolic androgens; norandrogens; porcine Leydig cells; sulfated steroids

DOI:  https://doi.org/10.1093/reprod/xaaf015
Anal Chem. 2026 Jan 20.

Biomimetic Formation and Tuning of a Cell Surface Heparan Sulfate Network: Approach on Deciphering the Glycosaminoglycans Code.

Yi-Zhen Wan, Xiaoling Zheng, Yu Zhang, Liming Liu, Bo Zhang, Tianze Wang, Weiping Qian.

The cell surface glycocalyx is a complex and dynamic network of glycoproteins and proteoglycans that plays a pivotal role in life activities. Its three-dimensional architecture is composed of various glycosaminoglycans (GAGs) mediating various biological functions. Exploring the structure of GAGs and its interaction with proteins or the GAGs code is of great significance for revealing the molecular mechanisms of biological processes. However, the structural complexity of the glycocalyx at both cellular and tissue scales poses challenges for accurate representation, while conventional planar sensors inadequately capture its multiscale spatial characteristics, thereby limiting precise analysis of dynamic GAG-protein interactions. In this study, a three-dimensional ordered interference substrate with surface-modified heparin was constructed to simulate the fine topological structure of the glycocalyx. On this ordered porous layer interferometry (OPLI) platform, combined with experimental and computer simulation methods, the effects of heparin density, spatial distribution, and chain length on the binding behavior of SARS-CoV-2 spike protein were systematically investigated. The experimental results show that a medium heparin density can maximize the binding strength of the spike protein. The affinity of heparin for spike protein can be enhanced by increasing the density of the three-dimensional spatial distribution. Molecular docking and thermodynamic experiments suggest that hydrogen bonds rather than electrostatic interactions play a crucial role in the binding strength. This study recreates the glycocalyx microenvironment, providing a highly biomimetic platform that not only deepens the molecular understanding of viral infection but also lays a methodological foundation for GAG code analysis and drug development.

DOI: https://doi.org/10.1021/acs.analchem.5c06749
iScience. 2026 Jan 16. 29(1): 114476

MARCHF1-mediated SULF1 degradation blocks THBS2/TGF-β/SMAD2/3 signaling to reverse colon cancer metastasis and 5-FU resistance.

Hui Li, Yong Xie.

  Colon cancer (CC) is a common and fatal malignancy with a poor prognosis, primarily due to difficulties in early detection and chemotherapy resistance. This study investigates the role of heparan sulfate 6-O-endosulfatase 1 (SULF1) in CC cell proliferation, migration, apoptosis, and invasion. Through clinical samples and CC cell lines, we found that SULF1 promotes cell proliferation and survival, while inhibiting apoptosis, migration, and invasion. SULF1 interacts with thrombospondin-2 (THBS2) to regulate the transforming growth factor β 1 (TGF-β1)/SMAD family member 2/3 (SMAD2/3) pathway, promoting tumor progression. Membrane associated ring-CH-type finger 1 (MARCHF1) inhibits SULF1 function by accelerating its degradation, thereby suppressing CC cell growth and metastasis. Moreover, SULF1 silencing enhances sensitivity to 5-fluorouracil (5-FU) chemotherapy. In conclusion, targeting SULF1 and its regulatory network may provide new therapeutic strategies for CC.

Keywords:  Biochemistry; Cancer; Cell biology

DOI:  https://doi.org/10.1016/j.isci.2025.114476
Int J Biol Macromol. 2026 Jan 15. pii: S0141-8130(26)00197-2. [Epub ahead of print] 150271

Discovery and engineering of chicken sulfotransferase SULT1B1 from Bambusicola thoracicus.

Mingzhu Yan, Qanli Zhang, Shuyao Yang, Liang Yin, Jiaying Wang, Weidong Liu, Jian Gao, Jinshan Li.

  Sulfotransferases (SULTs) can transfer sulfonate group from a donor molecule, typically 3'-phosphoadenosine-5'-phosphosulfate (PAPS), to a variety of acceptor molecules including hormones, drugs, and xenobiotics, thus play key roles in animal xenobiotic metabolisms and hormone regulations. Here, the first protein crystal structure of a chicken SULT1B1 BtSULT1B1 was obtained and its catalytic mechanism and substrate binding mode was elucidated by analyzing its structures in complex with substrates and donors like PAP, PAPS, pNP, pNPS and 2-Bromophenol. Notably, the gating loop of the substrate-binding pocket of BtSULT1B1 exhibits an enlarged cavity compared to homologous SULT structures from Human and Mouse, facilitating the acceptance of bulky substrates/products. Through conservative amino acid analysis and site-directed mutagenesis, a variant with 3.6-fold enhanced activity, A44S was obtained, and its mechanism was further illustrated by molecular dynamics simulations. The findings of the chicken SULT1B1 in this study expand the knowledge of substrate binding of sulfotransferases, and offer a rational approach for engineering enzymes with improved activities for specific applications, provide molecular basis for the design of in vitro sulfation platform and drug development.

Keywords:  Catalysis; Crystal structure; Gating loop; Protein engineering; Sulfotransferases

DOI:  https://doi.org/10.1016/j.ijbiomac.2026.150271
Front Pharmacol. 2025 ;16 1715462

Astaxanthin activates the Nrf2/HO-1 pathway to attenuate indoxyl sulfate-induced oxidative stress and DNA damage in renal tubular epithelial cells.

Xiaoli Qian, Zhixia Wang.

  Astaxanthin (AST) was investigated for its therapeutic role in chronic kidney disease (CKD) and its underlying mechanisms. Network pharmacology analysis identified 29 overlapping targets of AST and CKD, which were enriched in oxidative stress-related pathways, particularly the Nrf2/HO-1 axis. Molecular docking further confirmed stable binding of AST to hub proteins such as HMOX1, SOD2, and NOS2. In vitro, indoxyl sulfate (IS)-treated HK-2 cells were used to establish a CKD injury model. Cell viability was assessed by MTT assay, apoptosis by TUNEL staining and Western blotting, oxidative stress by ROS detection and measurement of glutathione (GSH), superoxide dismutase (SOD), and malondialdehyde (MDA). DNA damage was evaluated by alkaline comet assay and γH2AX expression, while cellular senescence was examined by SA-β-galactosidase staining and p53/p21 expression. IS exposure significantly increased apoptosis, oxidative stress, DNA damage, and senescence, while reducing cell viability, antioxidant capacity, and nuclear Nrf2 expression. AST treatment effectively reversed these changes, improving cell viability and antioxidant defenses, and alleviating apoptosis, ROS accumulation, DNA damage, and senescence. These integrated computational and experimental findings indicate that AST exerts renoprotective effects through coordinated modulation of multiple oxidative stress-related pathways, primarily via activation of the Nrf2/HO-1 signaling axis.

Keywords:  Nrf2/HO-1 pathway; astaxanthin; chronic kidney disease; network pharmacology; oxidative stress

DOI:  https://doi.org/10.3389/fphar.2025.1715462
Front Mol Biosci. 2025 ;12 1750807

Strategies of AAV capsid engineering for targeted delivery to brain, muscle, and retina.

Xinyuan Xu.

  Adeno-associated virus (AAV) vectors are widely used for in vivo gene delivery to the central nervous system (CNS), muscle, and retina, but many clinically used capsids show limited potency in human tissues, necessitating high systemic doses that increase cost and toxicity risk. Here, we summarize recent capsid-engineering strategies designed to improve on-target delivery and reduce vector dose requirements. For CNS applications, receptor-informed engineering-such as capsids targeting transferrin receptor 1 (TfR1) or alkaline phosphatase (ALPL)-has produced large gains in blood-brain barrier (BBB) penetration and cross-species translation. In the retina, intravitreal (IVT) performance improves through fine-tuning of heparan sulfate proteoglycan (HSPG) interactions to facilitate inner limiting membrane (ILM) traversal, while suprachoroidal and laterally spreading subretinal vectors expand posterior-segment coverage. For muscle, next-generation myotropic and liver-detargeted capsids enable uniform skeletal and cardiac transduction at substantially lower intravenous doses. We compare directed evolution, rational design, and machine-learning (ML) approaches, highlighting how these methods increasingly converge by integrating structural hypotheses, in vivo selections, and multi-trait computational optimization. Quantitative benchmarks across tissues demonstrate that engineered capsids routinely deliver multi-fold improvements in potency and biodistribution relative to natural serotypes. Collectively, these advances outline a translational path toward safer, lower-dose AAV gene therapies with improved precision and clinical feasibility.

Keywords:  adeno-associated virus; capsid engineering; directed evolution; machine learning; rational design

DOI:  https://doi.org/10.3389/fmolb.2025.1750807