Dual Properties of Lactate in Müller Cells: The Effect of GPR81 Activation

Rupali Vohra; Blanca I. Aldana; Helle Waagepetersen; Linda H. Bergersen; Miriam Kolko

doi:10.1167/iovs.18-25458

Dual Properties of Lactate in Müller Cells: The Effect of GPR81 Activation

Rupali Vohra, Blanca I. Aldana, Helle Waagepetersen, Linda H. Bergersen, Miriam Kolko

8 Citationer (Scopus)

14 Downloads (Pure)

Abstract

Purpose: Besides being actively metabolized, lactate may also function as a signaling molecule by activation of the G-protein-coupled receptor 81 (GPR81). Thus, we aimed to characterize the metabolic effects of GPR81 activation in Müller cells. Method: Primary Müller cells from mice were treated with and without 10 mM L-lactate in the presence or absence of 6 mM glucose. The effects of lactate receptor GPR81 activation were evaluated by the addition of 5 mM 3,5-DHBA (3,5-dihydroxybenzoic acid), a GPR81 agonist. Western blot analyses were used to determine protein expression of GPR81. Cell survival was assessed through 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) viability assays. Lactate release was quantified by commercially available lactate kits. 13C-labeling studies via mass spectroscopy and Seahorse analyses were performed to evaluate metabolism of lactate and glucose, and mitochondrial function. Finally, Müller cell function was evaluated by measuring glutamate uptake. Results: The lactate receptor, GPR81, was upregulated during glucose deprivation. Treatment with a GPR81 agonist did not affect Müller cell survival. However, GPR81 activation diminished lactate release allowing lactate to be metabolized intracellularly. Furthermore, GPR81 activation increased metabolism of glucose and mitochondrial function. Finally, maximal glutamate uptake decreased in response to GPR81 activation during glucose deprivation. Conclusions: The present study revealed dual properties of lactate via functioning as an active metabolic energy substrate and a regulatory molecule by activation of the GPR81 receptor in primary Müller cells. Thus, combinational therapy of lactate and GPR81 agonists may be of future interest in maintaining Müller cell survival, ultimately leading to increased resistance toward retinal neurodegeneration.

Originalsprog	Engelsk
Tidsskrift	Investigative Ophthalmology & Visual Science
Vol/bind	60
Udgave nummer	4
Sider (fra-til)	999-1008
Antal sider	10
ISSN	0146-0404
DOI	https://doi.org/10.1167/iovs.18-25458
Status	Udgivet - 1 mar. 2019

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10.1167/iovs.18-25458Licens: CC BY

i1552-5783-60-4-999Forlagets udgivne version, 869 KBLicens: CC BY

Citationsformater

@article{df51915f32bc4147a6520d1e43625db9,

title = "Dual Properties of Lactate in M{\"u}ller Cells: The Effect of GPR81 Activation",

abstract = "Purpose: Besides being actively metabolized, lactate may also function as a signaling molecule by activation of the G-protein-coupled receptor 81 (GPR81). Thus, we aimed to characterize the metabolic effects of GPR81 activation in M{\"u}ller cells. Method: Primary M{\"u}ller cells from mice were treated with and without 10 mM L-lactate in the presence or absence of 6 mM glucose. The effects of lactate receptor GPR81 activation were evaluated by the addition of 5 mM 3,5-DHBA (3,5-dihydroxybenzoic acid), a GPR81 agonist. Western blot analyses were used to determine protein expression of GPR81. Cell survival was assessed through 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) viability assays. Lactate release was quantified by commercially available lactate kits. 13C-labeling studies via mass spectroscopy and Seahorse analyses were performed to evaluate metabolism of lactate and glucose, and mitochondrial function. Finally, M{\"u}ller cell function was evaluated by measuring glutamate uptake. Results: The lactate receptor, GPR81, was upregulated during glucose deprivation. Treatment with a GPR81 agonist did not affect M{\"u}ller cell survival. However, GPR81 activation diminished lactate release allowing lactate to be metabolized intracellularly. Furthermore, GPR81 activation increased metabolism of glucose and mitochondrial function. Finally, maximal glutamate uptake decreased in response to GPR81 activation during glucose deprivation. Conclusions: The present study revealed dual properties of lactate via functioning as an active metabolic energy substrate and a regulatory molecule by activation of the GPR81 receptor in primary M{\"u}ller cells. Thus, combinational therapy of lactate and GPR81 agonists may be of future interest in maintaining M{\"u}ller cell survival, ultimately leading to increased resistance toward retinal neurodegeneration.",

author = "Rupali Vohra and Aldana, {Blanca I.} and Helle Waagepetersen and Bergersen, {Linda H.} and Miriam Kolko",

year = "2019",

month = mar,

day = "1",

doi = "10.1167/iovs.18-25458",

language = "English",

volume = "60",

pages = "999--1008",

journal = "Investigative Ophthalmology & Visual Science",

issn = "0146-0404",

publisher = "Association for Research in Vision and Ophthalmology",

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TY - JOUR

T1 - Dual Properties of Lactate in Müller Cells

T2 - The Effect of GPR81 Activation

AU - Vohra, Rupali

AU - Aldana, Blanca I.

AU - Waagepetersen, Helle

AU - Bergersen, Linda H.

AU - Kolko, Miriam

PY - 2019/3/1

Y1 - 2019/3/1

N2 - Purpose: Besides being actively metabolized, lactate may also function as a signaling molecule by activation of the G-protein-coupled receptor 81 (GPR81). Thus, we aimed to characterize the metabolic effects of GPR81 activation in Müller cells. Method: Primary Müller cells from mice were treated with and without 10 mM L-lactate in the presence or absence of 6 mM glucose. The effects of lactate receptor GPR81 activation were evaluated by the addition of 5 mM 3,5-DHBA (3,5-dihydroxybenzoic acid), a GPR81 agonist. Western blot analyses were used to determine protein expression of GPR81. Cell survival was assessed through 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) viability assays. Lactate release was quantified by commercially available lactate kits. 13C-labeling studies via mass spectroscopy and Seahorse analyses were performed to evaluate metabolism of lactate and glucose, and mitochondrial function. Finally, Müller cell function was evaluated by measuring glutamate uptake. Results: The lactate receptor, GPR81, was upregulated during glucose deprivation. Treatment with a GPR81 agonist did not affect Müller cell survival. However, GPR81 activation diminished lactate release allowing lactate to be metabolized intracellularly. Furthermore, GPR81 activation increased metabolism of glucose and mitochondrial function. Finally, maximal glutamate uptake decreased in response to GPR81 activation during glucose deprivation. Conclusions: The present study revealed dual properties of lactate via functioning as an active metabolic energy substrate and a regulatory molecule by activation of the GPR81 receptor in primary Müller cells. Thus, combinational therapy of lactate and GPR81 agonists may be of future interest in maintaining Müller cell survival, ultimately leading to increased resistance toward retinal neurodegeneration.

AB - Purpose: Besides being actively metabolized, lactate may also function as a signaling molecule by activation of the G-protein-coupled receptor 81 (GPR81). Thus, we aimed to characterize the metabolic effects of GPR81 activation in Müller cells. Method: Primary Müller cells from mice were treated with and without 10 mM L-lactate in the presence or absence of 6 mM glucose. The effects of lactate receptor GPR81 activation were evaluated by the addition of 5 mM 3,5-DHBA (3,5-dihydroxybenzoic acid), a GPR81 agonist. Western blot analyses were used to determine protein expression of GPR81. Cell survival was assessed through 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) viability assays. Lactate release was quantified by commercially available lactate kits. 13C-labeling studies via mass spectroscopy and Seahorse analyses were performed to evaluate metabolism of lactate and glucose, and mitochondrial function. Finally, Müller cell function was evaluated by measuring glutamate uptake. Results: The lactate receptor, GPR81, was upregulated during glucose deprivation. Treatment with a GPR81 agonist did not affect Müller cell survival. However, GPR81 activation diminished lactate release allowing lactate to be metabolized intracellularly. Furthermore, GPR81 activation increased metabolism of glucose and mitochondrial function. Finally, maximal glutamate uptake decreased in response to GPR81 activation during glucose deprivation. Conclusions: The present study revealed dual properties of lactate via functioning as an active metabolic energy substrate and a regulatory molecule by activation of the GPR81 receptor in primary Müller cells. Thus, combinational therapy of lactate and GPR81 agonists may be of future interest in maintaining Müller cell survival, ultimately leading to increased resistance toward retinal neurodegeneration.

U2 - 10.1167/iovs.18-25458

DO - 10.1167/iovs.18-25458

M3 - Journal article

C2 - 30884529

AN - SCOPUS:85063287313

SN - 0146-0404

VL - 60

SP - 999

EP - 1008

JO - Investigative Ophthalmology & Visual Science

JF - Investigative Ophthalmology & Visual Science

IS - 4

ER -

Dual Properties of Lactate in Müller Cells: The Effect of GPR81 Activation

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