Therapeutic targeting of SLC6A8 creatine transporter suppresses colon cancer progression and modulates human creatine levels.
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ABSTRACT:
SUBMITTER: Kurth I
PROVIDER: S-EPMC8494442 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:We report the first X-linked creatine-deficiency syndrome caused by a defective creatine transporter. The male index patient presented with developmental delay and hypotonia. Proton magnetic-resonance spectroscopy of his brain revealed absence of the creatine signal. However, creatine in urine and plasma was increased, and guanidinoacetate levels were normal. In three female relatives of the index patient, mild biochemical abnormalities and learning disabilities were present, to various extents. Fibroblasts from the index patient contained a hemizygous nonsense mutation in the gene SLC6A8 and were defective in creatine uptake. The three female relatives were heterozygous for this mutation in SLC6A8, which has been mapped to Xq28.
| S-EPMC1226136 | biostudies-literature
Project description:BackgroundCreatine transporter deficiency is an inborn error of metabolism caused by a deficiency in the creatine transporter protein encoded by the SLC6A8 gene. Previous treatment with creatine supplementation, either alone or in combination with creatine precursors (arginine or glycine), has been attempted; the efficacy of therapy, however, remains controversial.Methods and resultsTo analyze the treatment efficacy of high-dose creatine supplementation on creatine transporter deficiency, we reported a child diagnosed with creatine transporter deficiency, who was treated with a conventional dose of creatine (400 mg/kg/d) for 1 month, then twice the dose (800 mg/kg/d) for 2 months, and finally 3 times the dose (1200 mg/kg/d) for 3 months. The patient tolerated the treatment well and showed improvements in muscle mass and strength when the creatine dose was gradually increased to 1200 mg/kg/d. However, when assessed by proton magnetic resonance spectroscopy (H-MRS), the brain creatine concentration did not increase, and there was no improvement in speech and neurodevelopmental symptoms.ConclusionWe conclude that high-dose creatine supplementation (1200 mg/kg/d) alone improved muscular symptoms, but did not improve cognitive symptoms and brain creatine concentration assessed using H-MRS. Therefore, new treatment strategies are required for the management of creatine transporter deficiency.
| S-EPMC8123749 | biostudies-literature
Project description:Creatine transporter (CT) deficiency is an X-linked disorder caused by mutations in the SLC6A8 gene. We describe a clinical, biochemical and molecular examination of a child with X-linked cerebral creatine deficiency. Increased urinary creatine/creatinine ratio, abnormal brain proton magnetic resonance spectroscopy and reduced creatine transport confirmed the clinical diagnosis. SLC6A8 analysis revealed a novel mutation that was hemizygous in the child and not detected in his mother. CT deficiency should be considered in children, especially males, with mental retardation.
| S-EPMC4785581 | biostudies-literature
Project description:Creatine is a crucial metabolite that plays a fundamental role in ATP homeostasis in tissues with high-energy demands. The creatine transporter (CreaT, SLC6A8) belongs to the solute carrier 6 (SLC6) transporters family, and more particularly to the GABA transporters (GATs) subfamily. Understanding the molecular determinants of specificity within the SLC6 transporters in general, and the GATs in particular is very challenging due to the high similarity of these proteins. In the study presented here, our efforts focused on finding key structural features involved in binding selectivity for CreaT using structure-based computational methods. Due to the lack of three-dimensional structures of SLC6A8, our approach was based on the realization of two reliable homology models of CreaT using the structures of two templates, i.e. the human serotonin transporter (hSERT) and the prokaryotic leucine transporter (LeuT). Our models reveal that an optimal complementarity between the shape of the binding site and the size of the ligands is necessary for transport. These findings provide a framework for a deeper understanding of substrate selectivity of the SLC6 family and other LeuT fold transporters.
| S-EPMC7148354 | biostudies-literature
Project description:Creatine is an essential metabolite for the storage and rapid supply of energy in muscle and nerve cells. In humans, the creatine deficiency syndrome (CDS) is manifested by impaired metabolism, transport, and distribution of creatine throughout the body leading to severe forms of mental disabilities. One of the common cause of CDS is mutations that impact the function of the creatine transporter (SLC6A8). This study characterized 30 missense variants of SLC6A8, which include 15 variants of unknown significance and two which were not reported before. These variants were expressed in HEK293 cells, and their subcellular localization and transport activity was assessed. Further, for the first time the interactome of SLC6A8 WT was characterized by quantitative interaction proteomics. Computational methods were then used to first assess the impact of mutations upon the thermodynamic stability of SLC6A8. This was expanded by modeling the impact of mutations upon the inward and outward facing transporter conformation. Next, identified SLC6A8 protein interactions binary complexes were modelled and used to characterize the impact of variants upon the thermodynamic stability of the complexes. This was followed up, by performing for a subset of the variants the interaction proteomics analysis to study changes upon the identified SLC6A8 WT interactome.
2024-01-03 | PXD047111 | Pride
Project description:BACKGROUND:X-linked creatine transporter deficiency (OMIM#300036,CRTR-D) is characterized by cerebral creatine deficiency, intellectual disabilities, severe speech impairment, seizures and behavioral problems. Mutations in the creatine transporter gene SLC6A8, a member of the solute-carrier family 6 mapped to Xq28, have been reported to cause the creatine transporter deficiency. CASE PRESENTATION:The proband presented at 5 yrs. 1 month of age with delays in intellectual and development, seizures and behavioral problems. A novel missense mutation, c.1181C?>?A (p.Thr394Lys), in the SLC6A8 gene (NM_005629.3) was detected via targeted exome sequencing, and then validated by Sanger sequencing. Multiple in silico variant effect analysis methods, including SIFT, PolyPhen2, PROVEAN, and Mutation Taster predicted that this variant was likely damaging or diseasing-causing. This hemizygous variation was also identified in the affected brother with the same clinical condition and inherited from the heterozygous carrier mother. The diagnosis was suggested by increased urinary creatine/creatinine (Cr:Crn) ratio and markedly reduced creatine content peak by brain proton magnetic resonance spectroscopy (MRS). The proband's mother became pregnant with a 3rd sibling, in whom the Sanger sequencing result of c.1181C?>?A was negative. CONCLUSION:The novel mutation c.1181C?>?A in the SLC6A8 gene reported in a Chinese family has expanded the mutation spectrum of CRTR-D. The combination of powerful new technologies such as targeted exome sequencing with thorough systematic clinical evaluation of patients will improve the diagnostic yield, and assist in genetic counselling and prenatal diagnosis for suspected genetic disorders.
| S-EPMC6219255 | biostudies-literature
Project description:Intrahepatic cholangiocarcinoma (ICC) is a lethal malignancy with high mortality and lack of effective therapeutic targets. Here, we found that expression of cyclin-dependent kinase 7 (CDK7) was significantly associated with higher tumor grade and worse prognosis in 96 ICC specimens. Depletion of CDK7 significantly inhibited cell growth, induced a G2/M cell cycle arrest, and reduced the migratory and invasive potential in ICC cells. Subsequent experiments demonstrated that ICC cells were highly sensitive to the CDK7 inhibitor THZ1. A low concentration of THZ1 markedly inhibited cell growth, cell cycle, migration, and invasion in ICC cell lines. RNA-sequencing (RNA-seq) analysis revealed that THZ1 treatment decreased the levels of massive oncogene transcripts, particularly those associated with cell cycle and cell migration. Quantitative reverse transcriptase PCR (qRT-PCR) analysis confirmed that transcription of oncogenes involved in cell cycle regulation (AURKA, AURKB, CDC25B, CDK1, CCNA2, and MKI67) and the c-Met pathway (c-Met, AKT1, PTK2, CRK, PDPK1, and ARF6) was selectively repressed by THZ1. In addition, THZ1 exhibited significant anti-tumor activity in a patient-derived xenograft (PDX) model of ICC, without causing detectable side effects.
| S-EPMC7053328 | biostudies-literature
Project description:AimsIncreasing energy storage capacity by elevating creatine and phosphocreatine (PCr) levels to increase ATP availability is an attractive concept for protecting against ischaemia and heart failure. However, testing this hypothesis has not been possible since oral creatine supplementation is ineffectual at elevating myocardial creatine levels. We therefore used mice overexpressing creatine transporter in the heart (CrT-OE) to test for the first time whether elevated creatine is beneficial in clinically relevant disease models of heart failure and ischaemia/reperfusion (I/R) injury.Methods and resultsCrT-OE mice were selected for left ventricular (LV) creatine 20-100% above wild-type values and subjected to acute and chronic coronary artery ligation. Increasing myocardial creatine up to 100% was not detrimental even in ageing CrT-OE. In chronic heart failure, creatine elevation was neither beneficial nor detrimental, with no effect on survival, LV remodelling or dysfunction. However, CrT-OE hearts were protected against I/R injury in vivo in a dose-dependent manner (average 27% less myocardial necrosis) and exhibited greatly improved functional recovery following ex vivo I/R (59% of baseline vs. 29%). Mechanisms contributing to ischaemic protection in CrT-OE hearts include elevated PCr and glycogen levels and improved energy reserve. Furthermore, creatine loading in HL-1 cells did not alter antioxidant defences, but delayed mitochondrial permeability transition pore opening in response to oxidative stress, suggesting an additional mechanism to prevent reperfusion injury.ConclusionElevation of myocardial creatine by 20-100% reduced myocardial stunning and I/R injury via pleiotropic mechanisms, suggesting CrT activation as a novel, potentially translatable target for cardiac protection from ischaemia.
| S-EPMC3500046 | biostudies-literature
Project description:Colorectal and lung cancers account for one-third of all cancer-related deaths worldwide. Previous studies suggested that metadherin (MTDH) is involved in the development of colorectal and lung cancers. However, how MTDH regulates the pathogenesis of these cancers remains largely unknown. Using genetically modified mouse models of spontaneous colorectal and lung cancers, we found that MTDH promotes cancer progression by facilitating Wnt activation and by inducing cytotoxic T-cell exhaustion, respectively. Moreover, we developed locked nucleic acid-modified (LNA) MTDH antisense oligonucleotides (ASO) that effectively and specifically suppress MTDH expression in vitro and in vivo. Treatments with MTDH ASOs in mouse models significantly attenuated progression and metastasis of colorectal, lung, and breast cancers. Our study opens a new avenue for developing therapies against colorectal and lung cancers by targeting MTDH using LNA-modified ASO. SIGNIFICANCE: This study provides new insights into the mechanism of MTDH in promoting colorectal and lung cancers, as well as genetic and pharmacologic evidence supporting the development of MTDH-targeting therapeutics.
| S-EPMC8026491 | biostudies-literature
Project description:A family with X-linked mental retardation characterized by severe mental retardation, speech and behavioral abnormalities, and seizures in affected male patients has been found to have a G1141C transversion in the creatine-transporter gene SLC6A8. This mutation results in a glycine being replaced by an arginine (G381R) and alternative splicing, since the G-->C transversion occurs at the -1 position of the 5' splice junction of intron 7. Two female relatives who are heterozygous for the SLC6A8 mutation also exhibit mild mental retardation with behavior and learning problems. Male patients with the mutation have highly elevated creatine in their urine and have decreased creatine uptake in fibroblasts, which reflects the deficiency in creatine transport. The ability to measure elevated creatine in urine makes it possible to diagnose SLC6A8 deficiency in male patients with mental retardation of unknown etiology.
| S-EPMC447610 | biostudies-literature