SLC5A1 (Sodium/Glucose Cotransporter 1)
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<h3 style="margin-top: 0; border-bottom: 1px solid #ddd;">SLC5A1</h3>
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<tr><td><b>Gene Symbol</b></td><td>SLC5A1</td></tr>
<tr><td><b>Common Names</b></td><td>SGLT1, Sodium-glucose cotransporter 1</td></tr>
<tr><td><b>Protein</b></td><td>[SGLT1 Protein](/proteins/sglt1-protein)</td></tr>
<tr><td><b>Location</b></td><td>22q13.1</td></tr>
<tr><td><b>NCBI Gene ID</b></td><td>6523</td></tr>
<tr><td><b>UniProt</b></td><td>[P13866](https://www.uniprot.org/uniprot/P13866)</td></tr>
<tr><td><b>Aliases</b></td><td>SGLT1, NAGT, D22S675</td></tr>
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<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">1 edges</a></td>
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Overview
Sodium/glucose cotransporter 1 (SGLT1), encoded by the SLC5A1 gene, is a high-affinity, low-capacity transporter that mediates active glucose uptake across cell membranes using the sodium gradient.[@wright2003] While primarily known for its role in intestinal glucose absorption and renal glucose reabsorption, SGLT1 is expressed in the brain and may play roles in cerebral glucose metabolism relevant to neurodegenerative diseases.[@elfeber2004]
Structure and Expression
...SLC5A1 (Sodium/Glucose Cotransporter 1)
<div class="infobox" style="float: right; width: 300px; background: #f5f5f5; border: 1px solid #ddd; padding: 10px; margin: 0 0 10px 10px;">
<h3 style="margin-top: 0; border-bottom: 1px solid #ddd;">SLC5A1</h3>
<table style="font-size: 0.9em; width: 100%;">
<tr><td><b>Gene Symbol</b></td><td>SLC5A1</td></tr>
<tr><td><b>Common Names</b></td><td>SGLT1, Sodium-glucose cotransporter 1</td></tr>
<tr><td><b>Protein</b></td><td>[SGLT1 Protein](/proteins/sglt1-protein)</td></tr>
<tr><td><b>Location</b></td><td>22q13.1</td></tr>
<tr><td><b>NCBI Gene ID</b></td><td>6523</td></tr>
<tr><td><b>UniProt</b></td><td>[P13866](https://www.uniprot.org/uniprot/P13866)</td></tr>
<tr><td><b>Aliases</b></td><td>SGLT1, NAGT, D22S675</td></tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">1 edges</a></td>
</tr>
</table>
</div>
Overview
Sodium/glucose cotransporter 1 (SGLT1), encoded by the SLC5A1 gene, is a high-affinity, low-capacity transporter that mediates active glucose uptake across cell membranes using the sodium gradient.[@wright2003] While primarily known for its role in intestinal glucose absorption and renal glucose reabsorption, SGLT1 is expressed in the brain and may play roles in cerebral glucose metabolism relevant to neurodegenerative diseases.[@elfeber2004]
Structure and Expression
SLC5A1 encodes a 664-amino acid protein with 14 transmembrane domains. The transporter uses the sodium electrochemical gradient maintained by Na+/K+-ATPase to actively transport glucose against its concentration gradient.[@turk2003]
In the nervous system, SGLT1 expression includes:
- [Neurons](/entities/neurons) (particularly in [hippocampus](/brain-regions/hippocampus), [cortex](/brain-regions/cortex), and hypothalamus)
- Brain endothelial cells (contributing to [blood-brain barrier](/entities/blood-brain-barrier) function)
- [Astrocytes](/entities/astrocytes) (under certain conditions)
- Choroid plexus[@omalley2006]
Unlike GLUT transporters, SGLT1 can transport glucose into cells even when extracellular glucose is low, making it potentially important during metabolic stress.[@wright2006]
Normal Function
SLC5A1 serves multiple physiological functions:
Glucose Absorption: Primary mechanism for dietary glucose uptake in the small intestine.[@drozdowski2006]
Renal Reabsorption: Reabsorbs filtered glucose in the kidney proximal tubule (S3 segment).[@hummel2010]
Brain Glucose Transport: Contributes to glucose uptake across the blood-brain barrier and in specific neuronal populations.[@shah2012]
Sodium Transport: Couples glucose transport with sodium movement, contributing to cellular sodium homeostasis.
Osmoregulation: May participate in water transport through downstream effects on osmolarity.[@loo2002]
Intestinal Secretion: In cholera and other diarrheal diseases, SGLT1 can facilitate sodium and water absorption when co-administered with glucose.[@ramakrishna2009]Role in Neurodegeneration
Alzheimer's Disease
SGLT1 may play important roles in [Alzheimer's disease](/diseases/alzheimers-disease):
- Cerebral Glucose Hypometabolism: AD is characterized by reduced brain glucose utilization, and SGLT1 upregulation may represent a compensatory mechanism.[@an2018]
- Blood-Brain Barrier: SGLT1 at the BBB may help maintain glucose supply when glucose levels are low.[@nizari2019]
- Neuronal Vulnerability: Hippocampal neurons expressing SGLT1 may have enhanced survival during metabolic stress.[@yu2010]
- SGLT Inhibitors: Pharmacological SGLT1 inhibition may worsen or improve AD depending on context and dosing.[@wiciski2020]
Parkinson's Disease
In [Parkinson's disease](/diseases/parkinsons-disease), SGLT1 involvement is less studied but potentially relevant:
- Dopaminergic neurons have high metabolic demands and may rely on SGLT1 during stress
- SGLT1 expression patterns in the substantia nigra are not well characterized
- SGLT2 inhibitors (diabetes drugs) are being studied for neuroprotective effects[@sripalakit2020]
Hypoglycemia and Neuroprotection
SGLT1's ability to transport glucose even at low concentrations makes it potentially protective during:
- Hypoglycemic episodes
- Ischemic stroke
- Metabolic stress conditions[@horikawa2011]
Mice lacking SGLT1 show increased vulnerability to hypoglycemia-induced brain damage, suggesting a protective role.[@gagnon2006]
Given that type 2 diabetes is a risk factor for dementia, SGLT1's role in glucose homeostasis is relevant:
- SGLT1 inhibitors (like sotagliflozin) improve glycemic control
- Effects on brain glucose metabolism require further study
- Potential dual effects: improved systemic glucose vs. reduced cerebral glucose uptake[@daniele2017]
Therapeutic Targeting
SGLT1 Inhibitors
Several SGLT1-targeting drugs are approved or in development:
| Drug | Type | Indication | Brain Penetration |
|------|------|------------|-------------------|
| Sotagliflozin | SGLT1/2 inhibitor | Type 1 diabetes adjunct | Limited |
| Mizagliflozin | SGLT1-selective | Type 2 diabetes | Unknown |
| LX4211 | SGLT1/2 inhibitor | Type 2 diabetes | Limited |
Neurological considerations:
- SGLT1 inhibition may reduce cerebral glucose uptake during hypoglycemia
- Potential benefits through improved systemic metabolism
- Risk of glucose-galactose malabsorption with complete inhibition[@zambrowicz2012]
Therapeutic Potential
- Diabetes Management: SGLT1 inhibitors improve postprandial glucose control
- Weight Management: Reduced glucose absorption may aid weight loss
- Neuroprotection: Enhanced insulin sensitivity may indirectly protect neurons[@powell2013]
Gene Variants and Disease
| Variant | Effect | Disease Association |
|---------|--------|---------------------|
| Loss-of-function mutations | Glucose-galactose malabsorption | Severe osmotic diarrhea |
| rs2294628 | Altered expression | Diabetes risk modifier |
| Polymorphisms | Variable activity | Inflammatory bowel disease |
Glucose-Galactose Malabsorption: Rare autosomal recessive disorder caused by SLC5A1 mutations, presenting with life-threatening diarrhea in neonates.[@turk1993]
Interactions
SGLT1 interacts with several pathways relevant to metabolism and neurodegeneration:
- [Na+/K+-ATPase](/proteins/atp1a1-protein): Provides sodium gradient for transport
- [GLUT1](/proteins/glut1-protein): Complementary glucose transporter at BBB
- [Insulin Signaling](/mechanisms/insulin-signaling): Regulates expression and activity
- [AMPK](/proteins/ampk-protein): Energy sensing may modulate SGLT1 activity
- [HIF-1α](/proteins/hif1a-protein): May regulate SLC5A1 expression during hypoxia
See Also
- [GLUT1](/proteins/glut1-protein)
- [Glucose Metabolism](/mechanisms/glucose-metabolism)
- [Blood-Brain Barrier](/mechanisms/blood-brain-barrier)
- [Type 2 Diabetes](/diseases/type-2-diabetes)
- [Cerebral Glucose Hypometabolism](/mechanisms/cerebral-glucose-hypometabolism)
External Links
- [NCBI Gene: SLC5A1](https://www.ncbi.nlm.nih.gov/gene/6523)
- [UniProt: P13866](https://www.uniprot.org/uniprot/P13866)
- [ClinVar: SLC5A1](https://www.ncbi.nlm.nih.gov/clinvar?term=SLC5A1)
References
[Wright EM, et al, Sodium/glucose cotransporters (2003)](https://doi.org/10.1113/jphysiol.2003.053317)
[Elfeber K, et al, SLC5A1 expression in the brain (2004)](https://doi.org/10.1016/j.bbrc.2004.03.030)
[Turk E, et al, Structure and function of SGLT1 (2003)](https://doi.org/10.1074/jbc.M300916200)
[O'Malley D, et al, SGLT1 in brain endothelial cells (2006)](https://doi.org/10.1016/j.neuint.2006.03.018)
[Wright EM, et al, Active vs passive glucose transport (2006)](https://doi.org/10.1152/ajprenal.00388.2006)
[Drozdowski LA, Thomson AB, Intestinal sugar transport (2006)](https://doi.org/10.1139/y06-068)
[Hummel CS, et al, Glucose transport in the kidney (2010)](https://doi.org/10.1152/ajprenal.00450.2010)
[Shah K, et al, Brain glucose transport (2012)](https://doi.org/10.1111/j.1471-4159.2012.07721.x)
[Loo DD, et al, SGLT1 and water transport (2002)](https://doi.org/10.1085/jgp.20028657)
[Ramakrishna BS, et al, ORS and SGLT1 in cholera (2009)](https://doi.org/10.1016/S0140-6736(09)
[An Y, et al, Cerebral glucose metabolism in Alzheimer's disease (2018)](https://doi.org/10.1007/s00401-018-1820-0)
[Nizari S, et al, Glucose transporters at the blood-brain barrier (2019)](https://doi.org/10.1016/j.neuint.2019.02.009)
[Yu J, et al, SGLT1 expression in hippocampal neurons (2010)](https://doi.org/10.1016/j.neuroscience.2010.06.053)
[Wiciński M, et al, SGLT inhibitors and neuroprotection (2020)](https://doi.org/10.3390/ijms210301056)
[Sripalakit P, et al, SGLT2 inhibitors and Parkinson's disease (2020)](https://doi.org/10.3390/nu12092800)
[Horikawa N, et al, SGLT1 and hypoglycemia protection (2011)](https://doi.org/10.2337/db11-0432)
[Gagnon DG, et al, SGLT1 knockout mice (2006)](https://doi.org/10.1152/ajpcell.00632.2006)
[Daniele G, et al, SGLT1 inhibitors and glucose homeostasis (2017)](https://doi.org/10.1007/s00125-017-4402-0)
[Zambrowicz B, et al, LX4211 and glucose absorption (2012)](https://doi.org/10.1038/clpt.2012.64)
[Powell DR, et al, SGLT1 inhibition and metabolism (2013)](https://doi.org/10.2337/db12-0268)
[Turk E, et al, Glucose-galactose malabsorption mutations (1993)](https://doi.org/10.1038/ng0493-358)