Combined Hyperglycemia and Hyperinsulinemia-induced Insulin Resistance in Adipocytes is associated with Dual Signaling Defects mediated by PKC-ζ

Huogen Lu, Elena Bogdanovic, Zhiwen Yu, Charles Cho, Lijiang Liu, Karen Ho, June Guo, Lucy S. N. Yeung, Reiner Lehmann, Harinder S. Hundal, Adria Giacca, I. George Fantus (Lead / Corresponding author)

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Abstract

A hyperglycemic and hyperinsulinemic environment characteristic of type 2 diabetes causes insulin resistance. In adipocytes, defects in both insulin sensitivity and maximum response of glucose transport have been demonstrated. To investigate the molecular mechanisms, freshly isolated rat adipocytes were incubated in control (5.6 mM glucose, no insulin) and high glucose (20 mM)/high insulin (100 nM) (HG/HI) for 18 h to induce insulin resistance. Insulin resistant adipocytes manifested decreased sensitivity of glucose uptake associated with defects in IRS-1 Tyr phosphorylation, association of p85 subunit of phosphatidylinositol-3-kinase, AktSer473 and Thr308 phosphorylation accompanied by impaired glucose transporter 4 translocation. In contrast, PKC-ζ activity was augmented by chronic HG/HI. Inhibition of PKC-ζ with a specific cell permeable peptide reversed the signalling defects and insulin sensitivity of glucose uptake. Transfection of dominant-negative kinase-inactive PKC-ζ blocked insulin resistance, while constitutively-active PKC-ζ recapitulated the defects. The HG/HI incubation was associated with stimulation of IRS-1Ser318 and AktThr34 phosphorylation, targets of PKC-ζ. Transfection of IRS-1S318A and AktT34A each partially corrected, while combined transfection of both completely normalized insulin signaling. In vivo hyperglycemia/hyperinsulinemia in rats, for 48h similarly resulted in activation of PKC-ζ and increased phosphorylation of IRS-1 Ser318 and AktThr 34. These data indicate that impairment of insulin signaling by chronic HG/HI is mediated by dual defects at IRS-1 and Akt mediated by PKC-ζ.

Original languageEnglish
Pages (from-to)1658-1677
Number of pages20
JournalEndocrinology
Volume159
Issue number4
Early online date23 Jan 2018
DOIs
Publication statusPublished - 1 Apr 2018

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Hyperinsulinism
Adipocytes
Hyperglycemia
Insulin Resistance
Insulin
Glucose
Phosphorylation
Transfection
Phosphatidylinositol 3-Kinase
Facilitative Glucose Transport Proteins
Type 2 Diabetes Mellitus
Phosphotransferases
Peptides

Keywords

  • Adipocytes/drug effects
  • Animals
  • Glucose/pharmacology
  • Hyperglycemia/metabolism
  • Hyperinsulinism/metabolism
  • Insulin Receptor Substrate Proteins/metabolism
  • Insulin Resistance/physiology
  • Insulin/pharmacology
  • Male
  • Phosphatidylinositol 3-Kinases/metabolism
  • Phosphorylation/drug effects
  • Protein Kinase C/metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Signal Transduction/drug effects

Cite this

Lu, Huogen ; Bogdanovic, Elena ; Yu, Zhiwen ; Cho, Charles ; Liu, Lijiang ; Ho, Karen ; Guo, June ; Yeung, Lucy S. N. ; Lehmann, Reiner ; Hundal, Harinder S. ; Giacca, Adria ; Fantus, I. George. / Combined Hyperglycemia and Hyperinsulinemia-induced Insulin Resistance in Adipocytes is associated with Dual Signaling Defects mediated by PKC-ζ. In: Endocrinology. 2018 ; Vol. 159, No. 4. pp. 1658-1677.
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title = "Combined Hyperglycemia and Hyperinsulinemia-induced Insulin Resistance in Adipocytes is associated with Dual Signaling Defects mediated by PKC-ζ",
abstract = "A hyperglycemic and hyperinsulinemic environment characteristic of type 2 diabetes causes insulin resistance. In adipocytes, defects in both insulin sensitivity and maximum response of glucose transport have been demonstrated. To investigate the molecular mechanisms, freshly isolated rat adipocytes were incubated in control (5.6 mM glucose, no insulin) and high glucose (20 mM)/high insulin (100 nM) (HG/HI) for 18 h to induce insulin resistance. Insulin resistant adipocytes manifested decreased sensitivity of glucose uptake associated with defects in IRS-1 Tyr phosphorylation, association of p85 subunit of phosphatidylinositol-3-kinase, AktSer473 and Thr308 phosphorylation accompanied by impaired glucose transporter 4 translocation. In contrast, PKC-ζ activity was augmented by chronic HG/HI. Inhibition of PKC-ζ with a specific cell permeable peptide reversed the signalling defects and insulin sensitivity of glucose uptake. Transfection of dominant-negative kinase-inactive PKC-ζ blocked insulin resistance, while constitutively-active PKC-ζ recapitulated the defects. The HG/HI incubation was associated with stimulation of IRS-1Ser318 and AktThr34 phosphorylation, targets of PKC-ζ. Transfection of IRS-1S318A and AktT34A each partially corrected, while combined transfection of both completely normalized insulin signaling. In vivo hyperglycemia/hyperinsulinemia in rats, for 48h similarly resulted in activation of PKC-ζ and increased phosphorylation of IRS-1 Ser318 and AktThr 34. These data indicate that impairment of insulin signaling by chronic HG/HI is mediated by dual defects at IRS-1 and Akt mediated by PKC-ζ.",
keywords = "Adipocytes/drug effects, Animals, Glucose/pharmacology, Hyperglycemia/metabolism, Hyperinsulinism/metabolism, Insulin Receptor Substrate Proteins/metabolism, Insulin Resistance/physiology, Insulin/pharmacology, Male, Phosphatidylinositol 3-Kinases/metabolism, Phosphorylation/drug effects, Protein Kinase C/metabolism, Rats, Rats, Sprague-Dawley, Signal Transduction/drug effects",
author = "Huogen Lu and Elena Bogdanovic and Zhiwen Yu and Charles Cho and Lijiang Liu and Karen Ho and June Guo and Yeung, {Lucy S. N.} and Reiner Lehmann and Hundal, {Harinder S.} and Adria Giacca and Fantus, {I. George}",
note = "This work was supported by a grant from the Canadian Institutes for Heath Research (CIHR, Grant No. 38009). EB and CC were supported in part by studentships from the Banting and Best Diabetes Centre, University of Toronto. LL was supported by a visiting Scholarship from the China Scholarship Council, China",
year = "2018",
month = "4",
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doi = "10.1210/en.2017-00312",
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Lu, H, Bogdanovic, E, Yu, Z, Cho, C, Liu, L, Ho, K, Guo, J, Yeung, LSN, Lehmann, R, Hundal, HS, Giacca, A & Fantus, IG 2018, 'Combined Hyperglycemia and Hyperinsulinemia-induced Insulin Resistance in Adipocytes is associated with Dual Signaling Defects mediated by PKC-ζ', Endocrinology, vol. 159, no. 4, pp. 1658-1677. https://doi.org/10.1210/en.2017-00312

Combined Hyperglycemia and Hyperinsulinemia-induced Insulin Resistance in Adipocytes is associated with Dual Signaling Defects mediated by PKC-ζ. / Lu, Huogen; Bogdanovic, Elena; Yu, Zhiwen; Cho, Charles; Liu, Lijiang; Ho, Karen; Guo, June; Yeung, Lucy S. N.; Lehmann, Reiner; Hundal, Harinder S.; Giacca, Adria; Fantus, I. George (Lead / Corresponding author).

In: Endocrinology, Vol. 159, No. 4, 01.04.2018, p. 1658-1677.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Combined Hyperglycemia and Hyperinsulinemia-induced Insulin Resistance in Adipocytes is associated with Dual Signaling Defects mediated by PKC-ζ

AU - Lu, Huogen

AU - Bogdanovic, Elena

AU - Yu, Zhiwen

AU - Cho, Charles

AU - Liu, Lijiang

AU - Ho, Karen

AU - Guo, June

AU - Yeung, Lucy S. N.

AU - Lehmann, Reiner

AU - Hundal, Harinder S.

AU - Giacca, Adria

AU - Fantus, I. George

N1 - This work was supported by a grant from the Canadian Institutes for Heath Research (CIHR, Grant No. 38009). EB and CC were supported in part by studentships from the Banting and Best Diabetes Centre, University of Toronto. LL was supported by a visiting Scholarship from the China Scholarship Council, China

PY - 2018/4/1

Y1 - 2018/4/1

N2 - A hyperglycemic and hyperinsulinemic environment characteristic of type 2 diabetes causes insulin resistance. In adipocytes, defects in both insulin sensitivity and maximum response of glucose transport have been demonstrated. To investigate the molecular mechanisms, freshly isolated rat adipocytes were incubated in control (5.6 mM glucose, no insulin) and high glucose (20 mM)/high insulin (100 nM) (HG/HI) for 18 h to induce insulin resistance. Insulin resistant adipocytes manifested decreased sensitivity of glucose uptake associated with defects in IRS-1 Tyr phosphorylation, association of p85 subunit of phosphatidylinositol-3-kinase, AktSer473 and Thr308 phosphorylation accompanied by impaired glucose transporter 4 translocation. In contrast, PKC-ζ activity was augmented by chronic HG/HI. Inhibition of PKC-ζ with a specific cell permeable peptide reversed the signalling defects and insulin sensitivity of glucose uptake. Transfection of dominant-negative kinase-inactive PKC-ζ blocked insulin resistance, while constitutively-active PKC-ζ recapitulated the defects. The HG/HI incubation was associated with stimulation of IRS-1Ser318 and AktThr34 phosphorylation, targets of PKC-ζ. Transfection of IRS-1S318A and AktT34A each partially corrected, while combined transfection of both completely normalized insulin signaling. In vivo hyperglycemia/hyperinsulinemia in rats, for 48h similarly resulted in activation of PKC-ζ and increased phosphorylation of IRS-1 Ser318 and AktThr 34. These data indicate that impairment of insulin signaling by chronic HG/HI is mediated by dual defects at IRS-1 and Akt mediated by PKC-ζ.

AB - A hyperglycemic and hyperinsulinemic environment characteristic of type 2 diabetes causes insulin resistance. In adipocytes, defects in both insulin sensitivity and maximum response of glucose transport have been demonstrated. To investigate the molecular mechanisms, freshly isolated rat adipocytes were incubated in control (5.6 mM glucose, no insulin) and high glucose (20 mM)/high insulin (100 nM) (HG/HI) for 18 h to induce insulin resistance. Insulin resistant adipocytes manifested decreased sensitivity of glucose uptake associated with defects in IRS-1 Tyr phosphorylation, association of p85 subunit of phosphatidylinositol-3-kinase, AktSer473 and Thr308 phosphorylation accompanied by impaired glucose transporter 4 translocation. In contrast, PKC-ζ activity was augmented by chronic HG/HI. Inhibition of PKC-ζ with a specific cell permeable peptide reversed the signalling defects and insulin sensitivity of glucose uptake. Transfection of dominant-negative kinase-inactive PKC-ζ blocked insulin resistance, while constitutively-active PKC-ζ recapitulated the defects. The HG/HI incubation was associated with stimulation of IRS-1Ser318 and AktThr34 phosphorylation, targets of PKC-ζ. Transfection of IRS-1S318A and AktT34A each partially corrected, while combined transfection of both completely normalized insulin signaling. In vivo hyperglycemia/hyperinsulinemia in rats, for 48h similarly resulted in activation of PKC-ζ and increased phosphorylation of IRS-1 Ser318 and AktThr 34. These data indicate that impairment of insulin signaling by chronic HG/HI is mediated by dual defects at IRS-1 and Akt mediated by PKC-ζ.

KW - Adipocytes/drug effects

KW - Animals

KW - Glucose/pharmacology

KW - Hyperglycemia/metabolism

KW - Hyperinsulinism/metabolism

KW - Insulin Receptor Substrate Proteins/metabolism

KW - Insulin Resistance/physiology

KW - Insulin/pharmacology

KW - Male

KW - Phosphatidylinositol 3-Kinases/metabolism

KW - Phosphorylation/drug effects

KW - Protein Kinase C/metabolism

KW - Rats

KW - Rats, Sprague-Dawley

KW - Signal Transduction/drug effects

U2 - 10.1210/en.2017-00312

DO - 10.1210/en.2017-00312

M3 - Article

C2 - 29370351

VL - 159

SP - 1658

EP - 1677

JO - Endocrinology

JF - Endocrinology

SN - 0013-7227

IS - 4

ER -