The Phosphatase PHLPP2 Plays a Key Role in the Regulation of Pancreatic Beta-Cell Survival

Currently available antidiabetic treatments fail to halt, and may even exacerbate, pancreatic β-cell exhaustion, a key feature of type 2 diabetes pathogenesis; thus, strategies to prevent, or reverse, β-cell failure should be actively sought. The serine threonine kinase Akt has a key role in the reg...

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Main Authors: Marta Letizia Hribal, Elettra Mancuso, Gaetano Paride Arcidiacono, Annalisa Greco, Donatella Musca, Teresa Procopio, Mariafrancesca Ruffo, Giorgio Sesti
Format: Article
Language:English
Published: Wiley 2020-01-01
Series:International Journal of Endocrinology
Online Access:http://dx.doi.org/10.1155/2020/1027386
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author Marta Letizia Hribal
Elettra Mancuso
Gaetano Paride Arcidiacono
Annalisa Greco
Donatella Musca
Teresa Procopio
Mariafrancesca Ruffo
Giorgio Sesti
author_facet Marta Letizia Hribal
Elettra Mancuso
Gaetano Paride Arcidiacono
Annalisa Greco
Donatella Musca
Teresa Procopio
Mariafrancesca Ruffo
Giorgio Sesti
author_sort Marta Letizia Hribal
collection DOAJ
description Currently available antidiabetic treatments fail to halt, and may even exacerbate, pancreatic β-cell exhaustion, a key feature of type 2 diabetes pathogenesis; thus, strategies to prevent, or reverse, β-cell failure should be actively sought. The serine threonine kinase Akt has a key role in the regulation of β-cell homeostasis; among Akt modulators, a central role is played by pleckstrin homology domain leucine-rich repeat protein phosphatase (PHLPP) family. Here, taking advantage of an in vitro model of chronic exposure to high glucose, we demonstrated that PHLPPs, particularly the second family member called PHLPP2, are implicated in the ability of pancreatic β cells to deal with glucose toxicity. We observed that INS-1 rat pancreatic β cell line maintained for 12–15 passages at high (30 mM) glucose concentrations (INS-1 HG) showed increased expression of PHLPP2 and PHLPP1 both at mRNA and protein level as compared to INS-1 maintained for the same number of passages in the presence of normal glucose levels (INS-1 NG). These changes were paralleled by decreased phosphorylation of Akt and by increased expression of apoptotic and autophagic markers. To investigate if PHLPPs had a casual role in the alteration of INS-1 homeostasis observed upon chronic exposure to high glucose concentrations, we took advantage of shRNA technology to specifically knock-down PHLPPs. We obtained proof-of-concept evidence that modulating PHLPPs expression may help to restore a healthy β cell mass, as the reduced expression of PHLPP2/1 was accompanied by a recovered balance between pro- and antiapoptotic factor levels. In conclusion, our data provide initial support for future studies aimed to identify pharmacological PHLPPs modulator to treat beta-cell survival impairment. They also contribute to shed some light on β-cell dysfunction, a complex and unsatisfactorily characterized phenomenon that has a central causative role in the pathogenesis of type 2 diabetes.
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spelling doaj-art-325bb93ddba045149bf3de6cacd0ec002025-08-20T03:55:03ZengWileyInternational Journal of Endocrinology1687-83371687-83452020-01-01202010.1155/2020/10273861027386The Phosphatase PHLPP2 Plays a Key Role in the Regulation of Pancreatic Beta-Cell SurvivalMarta Letizia Hribal0Elettra Mancuso1Gaetano Paride Arcidiacono2Annalisa Greco3Donatella Musca4Teresa Procopio5Mariafrancesca Ruffo6Giorgio Sesti7Department of Medical and Surgical Sciences, University Magna Græcia of Catanzaro, Catanzaro, ItalyDepartment of Medical and Surgical Sciences, University Magna Græcia of Catanzaro, Catanzaro, ItalyDepartment of Medical and Surgical Sciences, University Magna Græcia of Catanzaro, Catanzaro, ItalyDepartment of Medical and Surgical Sciences, University Magna Græcia of Catanzaro, Catanzaro, ItalyDepartment of Medical and Surgical Sciences, University Magna Græcia of Catanzaro, Catanzaro, ItalyDepartment of Medical and Surgical Sciences, University Magna Græcia of Catanzaro, Catanzaro, ItalyDepartment of Medical and Surgical Sciences, University Magna Græcia of Catanzaro, Catanzaro, ItalyDepartment of Medical and Surgical Sciences, University Magna Græcia of Catanzaro, Catanzaro, ItalyCurrently available antidiabetic treatments fail to halt, and may even exacerbate, pancreatic β-cell exhaustion, a key feature of type 2 diabetes pathogenesis; thus, strategies to prevent, or reverse, β-cell failure should be actively sought. The serine threonine kinase Akt has a key role in the regulation of β-cell homeostasis; among Akt modulators, a central role is played by pleckstrin homology domain leucine-rich repeat protein phosphatase (PHLPP) family. Here, taking advantage of an in vitro model of chronic exposure to high glucose, we demonstrated that PHLPPs, particularly the second family member called PHLPP2, are implicated in the ability of pancreatic β cells to deal with glucose toxicity. We observed that INS-1 rat pancreatic β cell line maintained for 12–15 passages at high (30 mM) glucose concentrations (INS-1 HG) showed increased expression of PHLPP2 and PHLPP1 both at mRNA and protein level as compared to INS-1 maintained for the same number of passages in the presence of normal glucose levels (INS-1 NG). These changes were paralleled by decreased phosphorylation of Akt and by increased expression of apoptotic and autophagic markers. To investigate if PHLPPs had a casual role in the alteration of INS-1 homeostasis observed upon chronic exposure to high glucose concentrations, we took advantage of shRNA technology to specifically knock-down PHLPPs. We obtained proof-of-concept evidence that modulating PHLPPs expression may help to restore a healthy β cell mass, as the reduced expression of PHLPP2/1 was accompanied by a recovered balance between pro- and antiapoptotic factor levels. In conclusion, our data provide initial support for future studies aimed to identify pharmacological PHLPPs modulator to treat beta-cell survival impairment. They also contribute to shed some light on β-cell dysfunction, a complex and unsatisfactorily characterized phenomenon that has a central causative role in the pathogenesis of type 2 diabetes.http://dx.doi.org/10.1155/2020/1027386
spellingShingle Marta Letizia Hribal
Elettra Mancuso
Gaetano Paride Arcidiacono
Annalisa Greco
Donatella Musca
Teresa Procopio
Mariafrancesca Ruffo
Giorgio Sesti
The Phosphatase PHLPP2 Plays a Key Role in the Regulation of Pancreatic Beta-Cell Survival
International Journal of Endocrinology
title The Phosphatase PHLPP2 Plays a Key Role in the Regulation of Pancreatic Beta-Cell Survival
title_full The Phosphatase PHLPP2 Plays a Key Role in the Regulation of Pancreatic Beta-Cell Survival
title_fullStr The Phosphatase PHLPP2 Plays a Key Role in the Regulation of Pancreatic Beta-Cell Survival
title_full_unstemmed The Phosphatase PHLPP2 Plays a Key Role in the Regulation of Pancreatic Beta-Cell Survival
title_short The Phosphatase PHLPP2 Plays a Key Role in the Regulation of Pancreatic Beta-Cell Survival
title_sort phosphatase phlpp2 plays a key role in the regulation of pancreatic beta cell survival
url http://dx.doi.org/10.1155/2020/1027386
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