Endoplasmic reticulum stress regulates inflammation and insulin resistance in skeletal muscle from pregnant women

https://doi.org/10.1016/j.mce.2016.02.016Get rights and content

Highlights

  • ER stress is increased in skeletal muscle with GDM and obese pregnant women.

  • Suppression of ER stress decreased inflammation in skeletal muscle.

  • Suppression of ER stress improved insulin resistance in skeletal muscle.

Abstract

Sterile inflammation and infection are key mediators of inflammation and peripheral insulin resistance associated with gestational diabetes mellitus (GDM). Studies have shown endoplasmic reticulum (ER) stress to induce inflammation and insulin resistance associated with obesity and type 2 diabetes, however is paucity of studies investigating the effects of ER stress in skeletal muscle on inflammation and insulin resistance associated with GDM. ER stress proteins IRE1α, GRP78 and XBP-1s were upregulated in skeletal muscle of obese pregnant women, whereas IRE1α was increased in GDM women. Suppression of ER stress, using ER stress inhibitor tauroursodeoxycholic acid (TUDCA) or siRNA knockdown of IRE1α and GRP78, significantly downregulated LPS-, poly(I:C)- or IL-1β-induced production of IL-6, IL-8, IL-1β and MCP-1. Furthermore, LPS-, poly(I:C)- or TNF-α-induced insulin resistance was improved following suppression of ER stress, by increasing insulin-stimulated phosphorylation of IR-β, IRS-1, GLUT-4 expression and glucose uptake. In summary, our inducible obesity and GDM-like models suggests that the development of GDM may be involved in activating ER stress-induced inflammation and insulin resistance in human skeletal muscle.

Introduction

Gestational diabetes mellitus (GDM), defined as glucose intolerance with first onset during pregnancy, affects up to 18% of all pregnant women (Coustan et al., 2010). Advancing maternal age, ethnicity and obesity are known risk factors for GDM (Ferrara, 2007). GDM is associated with pregnancy complications and long-term adverse health problems for both mother and infant (Perkins et al., 2007, Al-Khalifah et al., 2012, Mitanchez, 2010). Pregnancy complications associated with GDM include fetal macrosomia, shoulder dystocia and higher rates of Caesarean delivery. Neonatal complications include jaundice, respiratory distress and hypoglycaemia. The long-term health risks for mothers and their infants include the development of cardiovascular diseases, obesity, type 2 diabetes and certain cancers later in life (Dabelea et al., 2000). With the growing rates of maternal obesity and GDM in developed countries, they are of significant public health concern with enormous long-term financial costs to the health care system and the community (Hossain et al., 2007).

Peripheral insulin resistance (Cani et al., 2007, Friedman et al., 2008, Borst, 2004, Catalano et al., 2003, Friedman et al., 1999, Kuhl, 1991) is a central feature of pregnancies complicated by maternal obesity and/or GDM. Insulin sensitivity is about 56% less in GDM pregnancies (Kuhl, 1991) and 47% less in obese normal glucose tolerant (NGT) pregnant women when compared to lean pregnant NGT women (Catalano et al., 1999). This decrease in insulin sensitivity is caused by multiple defects in the insulin signalling pathway in skeletal muscle of GDM and obese women (Friedman et al., 1999, Colomiere et al., 2009, Shao et al., 2002, Barbour et al., 2006). This pronounced peripheral insulin resistance increases nutrient availability to the fetus, which in turn increases the risk of fetal adiposity (Lain and Catalano, 2007) and also the development of childhood obesity and other metabolic dysfunctions later on in life (Dabelea et al., 2000).

Inflammation and endotoxemia are also key features of GDM and obese pregnancies (Lappas, 2014a, Lappas, 2014b, Lappas, 2014c, Lappas, 2014d, Radaelli et al., 2003, Basu et al., 2011, Sobel et al., 1992, Dhurandhar et al., 1997). We have previously shown that sterile inflammation and infections by bacteria or viruses can induce inflammation and insulin resistance in tissues from pregnant women (Lappas, 2014a, Lappas, 2014b, Lappas, 2014c, Lappas, 2014d, Lappas, 2015, Liong and Lappas, 2015a, Liong and Lappas, 2015b). There is, however, a paucity of studies that have investigated the mechanisms involved in peripheral insulin resistance and inflammation in skeletal muscle.

There is now increasing evidence that the inositol requiring enzyme 1α (IRE1α) arm of the endoplasmic reticulum (ER) stress response plays a key role in regulating inflammation and insulin resistance. Various endogenous and exogenous cellular insults such as viral infection, inflammation and environmental toxins are known to trigger the ER stress response (Shen et al., 2004) resulting in the induction of pro-inflammatory cytokines, chemokines and other mediators of the immune response in gestational and non-gestational tissues (Liong and Lappas, 2015a, Liong and Lappas, 2015b, Kim et al., 2013, Gargalovic et al., 2006, Martinon et al., 2010, Liong and Lappas, 2014). ER stress has also been implicated to be responsible for the development of peripheral insulin resistance, obesity and type 2 diabetes (Ozcan et al., 2004, Ozcan et al., 2006. Indeed, we have previously described the IRE1α arm of the ER stress response is increased in maternal adipose tissue from pregnancies complicated by GDM and obesity (Liong and Lappas, 2015a, Liong and Lappas, 2015b).

To our knowledge there have been no studies on the role of the IRE1α pathway of the ER stress response in skeletal muscle in the context of obesity in pregnancy and/or GDM. We hypothesise that (i) the IRE1α arm of the ER stress response is increased in skeletal muscle in pregnancies complicated by maternal obesity and/or GDM; (ii) inflammation and infection activate the IRE1α arm of the ER stress response in skeletal muscle; and (iii) inhibition of inflammation- and infection-induced ER stress decreases inflammation, activates the insulin signalling pathway and increases glucose uptake. Inflammation and insulin resistance, tissues were obtained from normal glucose tolerant (NGT) women and stimulated with either bacterial lipopolysaccharide (LPS; a toll-like receptor (TLR)4 ligand), polyinosinic-polycytidylic acid (poly(I:C); a TLR3 ligand), or pro-inflammatory cytokines (i.e. IL-1β, TNF-α) to generate models of obese and GDM-like state. To inhibit ER stress, we used (i) the ER stress inhibitor tauroursodeoxycholic acid (TUDCA), which is an endogenous bile acid derivative that acts as a potent chemical chaperone that inhibits the ER stress response (Ozcan et al., 2006, Miller et al., 2007); and (ii) siRNA specific knockdown of ER stress components IRE1α and GRP78 in primary human skeletal muscle cells.

Section snippets

Tissue collection and preparation

Human skeletal muscle tissue (pyramidalis) was obtained (with the Research Ethics Committee of Mercy Health approval) from consenting women who delivered healthy, singleton infants at term (>37 weeks gestation). Indications for Caesarean section were breech presentation and/or previous Caesarean section. Women with any underlying medical conditions such as pre-existing diabetes, asthma, polycystic ovarian syndrome, preeclampsia and macrovascular complications were excluded from this study.

ER stress is increased in skeletal muscle tissue from obese pregnant women

Skeletal muscle tissue was obtained from 12 NGT women at the time of term Caesarean section (in the absence of labour). Women were grouped as being either lean (n = 6 patients) or obese (n = 6 patients) based on pre-pregnancy BMI. Demographic data is summarised in Table 1. Maternal age, gestational age at delivery, and fetal birth weight did not differ between NGT obese versus lean women. As expected, maternal BMI (both pre-pregnancy and at delivery) was higher in obese compared to lean women.

Discussion

This study, for the first time, has demonstrated that the IRE1α arm of the ER stress pathway is increased in skeletal muscle tissue from obese pregnant women and women with GDM. Specifically, we found the expression of ER stress proteins IRE1α and XBP-1s, but not GRP78, were elevated in skeletal muscle of obese NGT women when compared to lean NGT women. Further, in lean GDM women, IRE1α, GRP78 and XBP-1s were also higher compared to lean NGT women. On the other hand, in obese women, only IRE1α

Disclosure statement

The authors have nothing to disclose.

Funding

Associate Professor Martha Lappas is supported by a Career Development Fellowship by the National Health and Medical Research Council (NHMRC; grant no. 1047025). Dr. Stella Liong is a recipient of the Glyn White Research Fellowship by the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG) Research Foundation. This work was funded by the Norman Beischer Medical Research Foundation.

Acknowledgements

The following are gratefully acknowledged: Gillian Barker (Obstetrics, Nutrition and Endocrinology Group, Department of Obstetrics and Gynaecology, University of Melbourne) for her technical assistance; the clinical Research Midwives Genevieve Christophers, Gabrielle Pell and Rachel Murdoch for sample collection; and the Obstetrics and Midwifery staff of the Mercy Hospital for Women for their co-operation.

References (70)

  • T.T. Lao et al.

    Maternal hepatitis B infection and gestational diabetes mellitus

    J. Hepatol.

    (2007)
  • M. Lappas

    Activation of inflammasomes in adipose tissue of women with gestational diabetes

    Mol. Cell Endocrinol.

    (2014)
  • M. Lappas

    Markers of endothelial cell dysfunction are increased in human omental adipose tissue from women with pre-existing maternal obesity and gestational diabetes

    Metabolism

    (2014)
  • M. Lappas

    Double stranded viral RNA induces inflammation and insulin resistance in skeletal muscle from pregnant women in vitro

    Metabolism

    (2015)
  • D. Mitanchez

    Foetal and neonatal complications in gestational diabetes: perinatal mortality, congenital malformations, macrosomia, shoulder dystocia, birth injuries, neonatal complications

    Diabetes Metab.

    (2010)
  • X. Shen et al.

    The unfolded protein response–a stress signaling pathway of the endoplasmic reticulum

    J. Chem. Neuroanat.

    (2004)
  • R. Al-Khalifah et al.

    Neonatal short-term outcomes of gestational diabetes mellitus in saudi mothers: a retrospective cohort study

    J. Clin. Neonatol.

    (2012)
  • F. Andreozzi et al.

    Interleukin-6 impairs the insulin signaling pathway, promoting production of nitric oxide in human umbilical vein endothelial cells

    Mol. Cell Biol.

    (2007)
  • L.A. Barbour et al.

    Reduced IRS-1 and increased serine IRS-1 phosphorylation skeletal muscle from women with GDM

    Diabetes

    (2006)
  • S. Basu et al.

    Pregravid obesity associates with increased maternal endotoxemia and metabolic inflammation

    Obes. Silver Spring

    (2011)
  • U. Beuers

    Drug insight: mechanisms and sites of action of ursodeoxycholic acid in cholestasis

    Nat. Clin. Pract. Gastroenterol. Hepatol.

    (2006)
  • S.E. Borst

    The role of TNF-alpha in insulin resistance

    Endocrine

    (2004)
  • D. Cai et al.

    Local and systemic insulin resistance resulting from hepatic activation of IKK-beta and NF-kappaB

    Nat. Med.

    (2005)
  • P.D. Cani et al.

    Metabolic endotoxemia initiates obesity and insulin resistance

    Diabetes

    (2007)
  • M. Colomiere et al.

    Defective insulin signaling in placenta from pregnancies complicated by gestational diabetes mellitus

    Eur. J. Endocrinol.

    (2009)
  • M. Colomiere et al.

    Diabetes and obesity during pregnancy alter insulin signalling and glucose transporter expression in maternal skeletal muscle and subcutaneous adipose tissue

    J. Mol. Endocrinol.

    (2010)
  • D.R. Coustan et al.

    The Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study: paving the way for new diagnostic criteria for gestational diabetes mellitus

    Am. J. Obstet. Gynecol.

    (2010)
  • D. Dabelea et al.

    Intrauterine exposure to diabetes conveys risks for type 2 diabetes and obesity: a study of discordant sibships

    Diabetes

    (2000)
  • N.V. Dhurandhar et al.

    Association of adenovirus infection with human obesity

    Obes. Res.

    (1997)
  • A. Ferrara

    Increasing prevalence of gestational diabetes mellitus: a public health perspective

    Diabetes Care

    (2007)
  • J.E. Friedman et al.

    Impaired glucose transport and insulin receptor tyrosine phosphorylation in skeletal muscle from obese women with gestational diabetes

    Diabetes

    (1999)
  • J.E. Friedman et al.

    Increased skeletal muscle tumor necrosis factor-alpha and impaired insulin signaling persist in obese women with gestational diabetes Mellitus 1 year postpartum

    Diabetes

    (2008)
  • P.S. Gargalovic et al.

    The unfolded protein response is an important regulator of inflammatory genes in endothelial cells

    Arterioscler. Thromb. Vasc. Biol.

    (2006)
  • S. Giri et al.

    5-aminoimidazole-4-carboxamide-1-beta-4-ribofuranoside inhibits proinflammatory response in glial cells: a possible role of AMP-activated protein kinase

    J. Neurosci.

    (2004)
  • N. Hata et al.

    Increased expression of IRE1alpha and stress-related signal transduction proteins in ischemia-reperfusion injured retina

    Clin. Ophthalmol.

    (2008)
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