Summary:
Researchers at the University of Eastern Finland have identified the sodium-dependent multivitamin transporter (SMVT) as a functional pathway to ferry creatine derivatives across the blood-brain barrier.
Published in ACS Chemical Neuroscience, the findings establish an alternative route for restoring brain energy metabolism in Creatine Transporter Deficiency Syndrome (CTDS), a severe genetic disorder where native creatine transport is impaired. By utilizing endogenous nutrient-uptake systems rather than attempting to force compounds through vascular defenses, this delivery mechanism offers a versatile platform for transporting diverse central nervous system therapeutics.
Key Facts:
- Alternative Gateway Identified: The sodium-dependent multivitamin transporter (SMVT), which physiologically mediates the uptake of essential water-soluble vitamins, can effectively transport synthesized creatine derivatives across the blood-brain barrier.
- Overcoming Genetic Transport Blocks: The approach provides a targeted solution for Creatine Transporter Deficiency Syndrome (CTDS), an X-linked metabolic disorder where the primary SLC6A8 creatine transporter is non-functional, leaving the brain depleted of essential cellular energy.
- Broad CNS Drug Delivery Platform: Beyond creatine replenishment, hijacking SMVTโs native carrier mechanisms provides a modular chemical framework to enhance the bioavailability of other neurotherapeutics that cannot otherwise cross brain capillary endothelial cells.
Source: University of Eastern Finland
The blood-brain barrier (BBB) functions as the central nervous systemโs most vigilant gatekeeper. Composed of tightly packed capillary endothelial cells anchored by tight junctions and surrounded by astrocytic end-feet, it prevents neurotoxins, pathogens, and systemic fluctuations from reaching fragile neural networks. However, this physiological shield represents one of the most formidable bottlenecks in pharmacology, excluding roughly 98% of small-molecule drugs and virtually all large biotherapeutics from entering the brain parenchyma.
Rather than attempting to disrupt this delicate vascular barrier, a tactic that risks neuroinflammation and systemic toxicity, pharmaceutical neuroscientists are increasingly turning to “Trojan horse” strategies: chemically disguising therapeutic molecules so they can hitch a ride aboard the natural influx transporters designed to feed the brain.
In a study published in ACS Chemical Neuroscience, researchers at the School of Pharmacy at the University of Eastern Finland (UEF) demonstrated that the sodium-dependent multivitamin transporter (SMVT) can serve as an alternative conduit for brain drug delivery, successfully shuttling creatine derivatives directly across cerebral microvessels.
Rescuing Brain Bioenergetics in CTDS
Creatine is essential for high-demand cellular bioenergetics, acting as a rapid spatial and temporal energy buffer that regenerates adenosine triphosphate (ATP) via the creatine kinase circuit. Because native cerebral synthesis meets only a fraction of the brain’s baseline energy needs, the central nervous system depends heavily on circulating creatine taken up via dedicated transmembrane carriers.
In Creatine Transporter Deficiency Syndrome (CTDS), a rare, X-linked inherited neurodevelopmental disorder caused by mutations in the SLC6A8 gene, the primary creatine transporter fails entirely. Affected children experience profound cerebral creatine depletion, resulting in severe intellectual disability, intractable speech delays, early-onset epilepsy, and autistic-like behaviors. Standard dietary creatine supplementation is clinically ineffective because the molecule cannot cross the brain’s microvascular endothelium without a functioning native transporter.
To circumvent this block, the UEF research team investigated whether SMVT, a solute carrier that naturally shuttles vital nutrients such as biotin and pantothenic acid into cells, could recognize engineered creatine conjugates.
Conducting in vitro and molecular delivery evaluations as part of the doctoral research projects of Adรฉla Krรกlovรก and Ville Kuorikoski, the investigators confirmed that modifying creatine into targeted prodrug derivatives enabled SMVT-mediated recognition and transport. This confirms that the brain’s multivitamin machinery can step in as a secondary gateway when standard creatine transport channels are compromised.
Turning the Barrier Into a Carrier
The success of this derivative-targeting strategy holds significance far beyond metabolic restoration in CTDS.
โThe most significant outcome of this study is that SMVT proved to be a suitable transporter for delivering different types of compounds into the brain,โ explains Associate Professor Kristiina Huttunen, who led the research team at UEF. โThe blood-brain barrier is not merely a barrier; it also contains transport systems that allow essential nutrients to reach the brain. Rather than trying to bypass the blood-brain barrier, our goal is to take advantage of its own transport mechanisms to deliver compounds into the brain. Our results suggest that SMVT could offer a promising new opportunity for this purpose.โ
Because SMVT is stably expressed along the human brain capillary endothelium, conjugating neuroactive molecules to SMVT-recognized chemical motifs provides a reproducible method for enhancing the blood-brain permeability of diverse therapeutic classes, from neuroprotective compounds to anticonvulsants.
Supported by a Proof of Concept (PoC) award from the Jane and Aatos Erkko Foundation, the investigators are advancing these synthesized derivatives into pre-clinical pharmacokinetic evaluations to validate sustained cerebral uptake and functional ATP restoration in vivo.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- Journal paper reviewed in full.
- Additional context added by our staff.
About this neuroscience Research:
- Media Contact:ย Kristiina Huttunen
- Source:ย University of Eastern Finland
- Image Credit:ย Image credited to Neuroscience News
- Original Research is Open Access:ย ACS Chemical Neuroscience (Oct 1, 2026). โSodium-Dependent Multivitamin Transporter Facilitates Brain and Neuronal Uptake of a Creatine Analogue.โ Authors: Adรฉla Krรกlovรก, Ville Kuorikoski, Landry Anamea, Janne Tampio, Arun Kumar Tonduru, Hengjing Cui, Henri Leinonen, Jaana Rysรค, Antti Poso, Tetsuya Terasaki, Aaro Jalkanen, Thales Kronenberger, and Kristiina M. Huttunen.
- DOI:ย 10.1021/acschemneuro.6c00484
Abstract
Sodium-Dependent Multivitamin Transporter Facilitates Brain and Neuronal Uptake of a Creatine Analogue
Creatine transporter 1 (CRT1, SLC6A8) is a membrane transporter essential for importing creatine across the bloodโbrain barrier (BBB) into neurons and glial cells. Loss-of-function mutations in CRT1 result in creatine transporter deficiency syndrome (CTDS), a severe X-linked neurological disorder with no effective treatment.
To explore alternative uptake pathways for creatine, a carrier-mediated delivery system utilizing the sodium-dependent multivitamin transporter (SMVT), a potential neuronal target to facilitate creatine brain uptake, was employed.
In this study, SMVT was investigated in silico and in vitro to identify key substrate-binding residues and to functionally characterize the transporter in human glioblastoma (U-87MG) and mouse neuronal cells. Furthermore, four novel SMVT-utilizing creatine derivatives were designed, synthesized, and assessed in vitro. The most promising derivative was studied in vivo and in a creatine kinase (CK) enzymatic assay and molecular dynamics (MD) simulations to determine its interactions with the ATP/ADP system.
The studies confirmed SMVT expression in human glioblastoma cells and mouse neurons, and functional assays demonstrated pH- and concentration-dependent transporter activity in both cell lines. The creatine derivatives were taken up by human glioblastoma cells, and the lead derivative, compound 1 (COMP 1), demonstrated SMVT-mediated uptake at concentrations below 100 ฮผM and was also taken up by mouse neurons.
Finally, COMP 1 accumulated in the mouse brain and showed interactions with the CK system. Collectively, these findings identify SMVT as a potential route for brain uptake of creatine derivatives and support further investigation of SMVT-targeting derivatives in relevant CTDS animal models.
