Dataset Information

Antipsychotics inhibit glucose transport: Determination of olanzapine binding site in Staphylococcus epidermidis glucose/H(+) symporter.

ABSTRACT: The antipsychotic drug olanzapine is widely prescribed to treat schizophrenia and other psychotic disorders. However, it often causes unwanted side effects, including diabetes, due to disruption of insulin-dependant glucose metabolism through a mechanism yet to be elucidated. To determine if olanzapine can affect the first step in glucose metabolism - glucose transport inside cells - we investigated the effect of this drug on the transport activity of a model glucose transporter. The glucose transporter from Staphylococcus epidermidis (GlcPSe) is specific for glucose, inhibited by various human glucose transporter (GLUT) inhibitors, has high sequence and structure homology to GLUTs, and is readily amenable to transport assay, mutagenesis, and computational modeling. We found that olanzapine inhibits glucose transport of GlcPSe with an IC50 0.9 ± 0.1 mM. Computational docking of olanzapine to the GlcPSe structure revealed potential binding sites that were further examined through mutagenesis and transport assay to identify residues important for olanzapine inhibition. These investigations suggest that olanzapine binds in a polar region of the cytosolic part of the transporter, and interacts with residues R129, strictly conserved in all GLUTs, and N136, conserved in only a few GLUTs, including the insulin-responsive GLUT4. We propose that olanzapine inhibits GlcPSe by impeding the alternating opening and closing of the substrate cavity necessary for glucose transport. It accomplishes this by disrupting a key salt bridge formed by conserved residues R129 and E362, that stabilizes the outward-facing conformation of the transporter.

SUBMITTER: Babkin P

PROVIDER: S-EPMC4412883 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature

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Antipsychotics inhibit glucose transport: Determination of olanzapine binding site in Staphylococcus epidermidis glucose/H(+) symporter.

Babkin Petr P George Thompson Alayna M AM Iancu Cristina V CV Walters D Eric DE Choe Jun-Yong JY

FEBS open bio 20150415

The antipsychotic drug olanzapine is widely prescribed to treat schizophrenia and other psychotic disorders. However, it often causes unwanted side effects, including diabetes, due to disruption of insulin-dependant glucose metabolism through a mechanism yet to be elucidated. To determine if olanzapine can affect the first step in glucose metabolism - glucose transport inside cells - we investigated the effect of this drug on the transport activity of a model glucose transporter. The glucose tra ...[more]

PMID: 25941630

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Project description:Medication non-adherence in patients with schizophrenia continues to be a significant problem and threatens successful treatment outcomes. Medication non-adherence is often associated with negative consequences, including symptom exacerbation, more frequent emergency room visits, re-hospitalizations and relapse. Long-acting injectable (LAI) forms of antipsychotics allow for rapid identification of non-adherence, obviate the need for the patient to take the medication on a daily basis and increase adherence to some significant degree. Eli Lilly has developed a long-acting depot formulation of olanzapine, olanzapine pamoate, which has recently been approved by the FDA for the US market, and which will be reviewed here. Olanzapine LAI appears to be an effective antipsychotic at dosages of 210 mg every 2 weeks, 300 mg every 2 weeks and 405 mg every 4 weeks in patients with acute schizophrenia, and at 150 mg every 2 weeks, 300 mg every 2 weeks and at 405 mg every 4 weeks for the maintenance treatment of stable patients. Oral supplementation appears not to be needed, particularly not at the onset of treatment with the LAI as is necessary with risperidone LAI. Its efficacy is in general comparable to the efficacy seen with oral olanzapine at a corresponding dose. The side effect profile is also comparable to the side effects observed with oral olanzapine, including lower rates of extrapyramidal symptoms, prolactin elevation and cardiovascular side effects, but significant metabolic effects. The latter include significant weight gain, lipid abnormalities and glucose dysregulation. While the injection site adverse events are overall mild, the most significant serious adverse event is the post-injection delirium sedation syndrome (PDSS). While rare, this syndrome results from inadvertent intravascular injection of olanzapine LAI and can cause a range of olanzapine overdose-type of symptoms. Olanzapine LAI needs therefore to be administered by trained personnel in settings where a post-injection observation period for at least 3 hours by medical personnel is available. The overall use of olanzapine LAI will probably be limited by the possibility of a PDSS event. Patients who have a history of good response to oral olanzapine and are in need of assured medication administration may present a good indication for its use, provided that the appropriate mental health delivery setting is available.

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Dataset Information

Antipsychotics inhibit glucose transport: Determination of olanzapine binding site in Staphylococcus epidermidis glucose/H(+) symporter.

Publications

Antipsychotics inhibit glucose transport: Determination of olanzapine binding site in Staphylococcus epidermidis glucose/H(+) symporter.

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