title: Palmitate and inflammatory state additively induce the expression of PTP1B in muscle cells.
abstract: The factors responsible for up-regulation of PTP1B, a negative regulator of insulin signaling, in insulin resistance state are not well understood. We performed a series of experiments in C2C12 muscle cells to determine the role of palmitate and an inflammatory state in regulation of PTP1B. Palmitate (0.75mM) induced PTP1B mRNA and protein level only at 16h. The combination of palmitate and macrophages, accompanied by a great increase of TNF-alpha and IL-6 in the culture media, additively caused a higher level of PTP1B protein levels in the muscle. Higher concentrations of palmitate reduced insulin stimulated glucose uptake in myotubes. A specific inhibitor of PTP1B partly increased insulin stimulated glucose uptake in palmitate treated cells. In conclusion, our results showing the additive influence of palmitate and the inflammatory state in the expression of PTP1B imply the involvement of these factors in the overexpression of PTP1B in insulin resistance state. We further provided the evidence suggesting the mediatory role for PTP1B in palmitate induced insulin resistance in myotubes.
authors.affiliation: Department of Clinical Biochemistry, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Islamic Republic of Iran.
authors.forename: Leila
authors.initials: L
authors.lastname: Parvaneh
authors.forename: Reza
authors.initials: R
authors.lastname: Meshkani
authors.forename: Salar
authors.initials: S
authors.lastname: Bakhtiyari
authors.forename: Narges
authors.initials: N
authors.lastname: Mohammadtaghvaie
authors.forename: Sattar
authors.initials: S
authors.lastname: Gorganifiruzjaee
authors.forename: Gholamreza
authors.initials: G
authors.lastname: Taheripak
authors.forename: Abolfazl
authors.initials: A
authors.lastname: Golestani
authors.forename: Mehdi
authors.initials: M
authors.lastname: Foruzandeh
authors.forename: Bagher
authors.initials: B
authors.lastname: Larijani
authors.forename: Mohammad
authors.initials: M
authors.lastname: Taghikhani
mesh_terms: D000818:Animals; D003470:Culture Media / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D005947:Glucose / Q000378:metabolism; D007249:Inflammation / Q000201:enzymology; D007328:Insulin / Q000494:pharmacology; D007333:Insulin Resistance; D008264:Macrophages / Q000502:physiology; D051379:Mice; D018485:Muscle Fibers, Skeletal / Q000201:enzymology*; D010168:Palmitates / Q000378:metabolism* / Q000494:pharmacology; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1 / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D003470:Culture Media; D016207:Cytokines; D007328:Insulin; D010168:Palmitates; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; C516609:Ptpn1 protein, mouse; D005947:Glucose