Cell lines

Myotubes cells (C₂C₁₂)

Preparation Method

Serum-starved C₂C₁₂cells were treated with the indicated concentrations of thapsigargin, tunicamycin,or SubAB to induct ER stress, for 12–24 h before stimulation with Bovine insulin for 15 min. Cell lysates were analyzed by Western blotting.

Reaction Conditions

100 nM Insulin for 15min.

Applications

24 hours after induction of ER stress, insulin-stimulated S473 phosphorylation of AKT was decreased in C₂C₁₂cells exposed to all ER stress-inducing conditions.

Animal models

Mice lacking insulin receptors in tanycytes (IR?Tan mice)

Preparation Method

IR?Tan mice were fasted overnight for 16 h and anesthetized with ketamine/xylazine. Insulin was injected in the vena cava and animals were perfused at 5, 10, 20 at 30 min post injection as described below.

Dosage form

0.5 IU/kg Insulin, intravenous(i.v.) injection

Applications

Insulin treatment robustly induced AKT phosphorylation in tanycytes of control mice, and that this activation was largely diminished in tanycytes of IR?Tan mice.

• Biomedicines 9.5 (2021): 581.

Insulin is a hormonal protein consisting of two chains of 21 and 30 amino acids. Insulin acts on neurons and glial cells to regulate systemic glucose metabolism and feeding. Insulins(cattle) is a type of native insulins. Insulins(cattle) was used to treat patients presenting with diabetes mellitus^[1].

Insulin signaling is initiated by binding of insulin to the insulin receptor, activation of the protein tyrosine kinase domain and tyrosine autophosphorylation of the insulin receptor, and extensive tyrosine phosphorylation of insulin receptor substrate (IRS) proteins, and phosphorylation of S473 in AKT^[2]

Injected mice with insulin (i.v., 0.5 IU/ kg–1 body weight) and assessed phosphorylated AKT (pAKT) immunoreactivity in tanycytes. These analyses revealed that insulin treatment robustly induced AKT phosphorylation in tanycytes of control mice, and that this activation was largely diminished in tanycytes of IR?Tan mice(mice lacking insulin receptors in tanycytes)^[3]

References:
[1]. Adams GG, Meal A, Morgan PS, Alzahrani QE, Zobel H, Lithgo R, Kok MS, Besong DTM, Jiwani SI, Ballance S, Harding SE, Chayen N, Gillis RB. Characterisation of insulin analogues therapeutically available to patients. PLoS One. 2018 Mar 29;13(3):e0195010.
[2]. Brown M, Dainty S, et al. Endoplasmic reticulum stress causes insulin resistance by inhibiting delivery of newly synthesized insulin receptors to the cell surface. Mol Biol Cell. 2020 Nov 1;31(23):2597-2629.
[3]. Porniece Kumar M, et al. Insulin signalling in tanycytes gates hypothalamic insulin uptake and regulation of AgRP neuron activity. Nat Metab. 2021 Dec;3(12):1662-1679.