Insulin Receptor Substrate 1 Is Involved in the Phycocyanin-Mediated Antineoplastic Function of Non-Small Cell Lung Cancer Cells

The Insulin Receptor Substrate 2 Mediates the Action of Insulin on HeLa Cell Migration via the PI3K/Akt Signaling Pathway

Insulin signaling plays an important role in the development and progression of cancer since it is involved in proliferation and migration processes. It has been shown that the A isoform of the insulin receptor (IR-A) is often overexpressed, and its stimulation induces changes in the expression of the insulin receptor substrates (IRS-1 and IRS-2), which are expressed differently in the different types of cancer. We study the participation of the insulin substrates IRS-1 and IRS-2 in the insulin signaling pathway in response to insulin and their involvement in the proliferation and migration of the cervical cancer cell line. Our results showed that under basal conditions, the IR-A isoform was predominantly expressed. Stimulation of HeLa cells with 50 nM insulin led to the phosphorylation of IR-A, showing a statistically significant increase at 30 min (p ≤ 0.05). Stimulation of HeLa cells with insulin induces PI3K and AKT phosphorylation through the activation of IRS2, but not IRS1. While PI3K reached the highest level at 30 min after treatment (p ≤ 0.05), AKT had the highest levels from 15 min (p ≤ 0.05) and remained constant for 6 h. ERK1 and ERK2 expression was also observed, but only ERK2 was phosphorylated in a time-dependent manner, reaching a maximum peak 5 min after insulin stimulation. Although no effect on cell proliferation was observed, insulin stimulation of HeLa cells markedly promoted cell migration.

The crucial role of thioredoxin interacting protein in the liver insulin resistance induced by di (2-ethylhexyl) phthalates

The widespread usage of plastic products in human life has led to extensive exposure to plasticizers and resulted in serious health problems for humans, which has become a focus of toxicology research in the world. We aimed to explore the potential mechanism of liver insulin resistance induced by di(2-ethylhexyl) phthalate (DEHP) and working on a novel treatment to alleviate insulin resistance caused by excessive exposure to DEHP. For this purpose, in vivo and in vitro experiments were conducted, and the pivotal factors in the insulin signaling pathway were analyzed. In vivo study showed DEHP could lead to liver injury and insulin resistance. DEHP could break the balance of oxidative stress and cause accumulation of inflammatory factors. Genomics and proteomics experiment results revealed that DEHP could inhibit the mRNA and protein expression of insulin receptor, insulin receptor substrate, PI3K/Akt/mTOR, and glucose transporter 4. Nevertheless, the liver insulin resistance induced by DEHP could be reversed by Verapamil (thioredoxin interacting protein (TXNIP) inhibitor). Thus, we confirmed that DEHP caused insulin resistance by affecting the TXNIP in liver, further damaging the conduction of insulin signaling pathway. Therefore, adding Verapamil to the treatment of patients with insulin resistance due to plasticizers might be more effective.

Studies on the biosynthetic pathways of melanin in Auricularia auricula

Melanin is a natural pigment ubiquitously present in living organisms, including bacteria, fungi, plants, and animals. Melanin produced by the edible mushroom Auricularia auricula has a remarkable potential for resource development. Several A. auricula strains planted across China were collected and analyzed for mycelial growth rate and colony RGB value for color block. Further, the effects of various nutrients on melanin formation, including different carbon and nitrogen sources were evaluated to optimize medium for submerged fermentation. The pathways involved in the biosynthesis of melanin in A. auricula were investigated using an enzyme inhibitor assay and intermediate determination. In addition, the functional activity of purified A. auricula melanin was assessed. The highest melanin yield (1.797 g/L) was displayed by strain AU-3 in medium I. A. auricula melanin was composed of eumelanin, pheomelanin and 1,8-dihydroxynaphthalene melanin, and the biosynthetic pathways involved were Raper-Mason and 1,8-dihydroxynaphthalene melanin pathway. In addition, melanin purified from A. auricula exhibited substantial antioxidant, antibacterial, and antitumor activities. This article is protected by copyright. All rights reserved.