scholarly journals The IGF-1 Signaling Pathway in Viral Infections

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1488
Author(s):  
Agata Józefiak ◽  
Magdalena Larska ◽  
Małgorzata Pomorska-Mól ◽  
Jakub J. Ruszkowski

Insulin-like growth factor-1 (IGF-1) and the IGF-1 receptor (IGF-1R) belong to the insulin-like growth factor family, and IGF-1 activates intracellular signaling pathways by binding specifically to IGF-1R. The interaction between IGF-1 and IGF-1R transmits a signal through a number of intracellular substrates, including the insulin receptor substrate (IRS) and the Src homology collagen (Shc) proteins, which activate two major intracellular signaling pathways: the phosphatidylinositol 3-kinase (PI3K)/AKT and mitogen-activated protein kinase (MAPK) pathways, specifically the extracellular signal-regulated kinase (ERK) pathways. The PI3K/AKT kinase pathway regulates a variety of cellular processes, including cell proliferation and apoptosis. IGF1/IGF-1R signaling also promotes cell differentiation and proliferation via the Ras/MAPK pathway. Moreover, upon IGF-1R activation of the IRS and Shc adaptor proteins, Shc stimulates Raf through the GTPase Ras to activate the MAPKs ERK1 and ERK2, phosphorylate and several other proteins, and to stimulate cell proliferation. The IGF-1 signaling pathway is required for certain viral effects in oncogenic progression and may be induced as an effect of viral infection. The mechanisms of IGF signaling in animal viral infections need to be clarified, mainly because they are involved in multifactorial signaling pathways. The aim of this review is to summarize the current data obtained from virological studies and to increase our understanding of the complex role of the IGF-1 signaling axis in animal virus infections.

Pharmaceutics ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1198
Author(s):  
Sathishbabu Paranthaman ◽  
Meghana Goravinahalli Shivananjegowda ◽  
Manohar Mahadev ◽  
Afrasim Moin ◽  
Shivakumar Hagalavadi Nanjappa ◽  
...  

A paradigm shift in treating the most aggressive and malignant form of glioma is continuously evolving; however, these strategies do not provide a better life and survival index. Currently, neurosurgical debulking, radiotherapy, and chemotherapy are the treatment options available for glioma, but these are non-specific in action. Patients invariably develop resistance to these therapies, leading to recurrence and death. Receptor Tyrosine Kinases (RTKs) are among the most common cell surface proteins in glioma and play a significant role in malignant progression; thus, these are currently being explored as therapeutic targets. RTKs belong to the family of cell surface receptors that are activated by ligands which in turn activates two major downstream signaling pathways via Rapidly Accelerating Sarcoma/mitogen activated protein kinase/extracellular-signal-regulated kinase (Ras/MAPK/ERK) and phosphatidylinositol 3-kinase/a serine/threonine protein kinase/mammalian target of rapamycin (PI3K/AKT/mTOR). These pathways are critically involved in regulating cell proliferation, invasion, metabolism, autophagy, and apoptosis. Dysregulation in these pathways results in uncontrolled glioma cell proliferation, invasion, angiogenesis, and cancer progression. Thus, RTK pathways are considered a potential target in glioma management. This review summarizes the possible risk factors involved in the growth of glioblastoma (GBM). The role of RTKs inhibitors (TKIs) and the intracellular signaling pathways involved, small molecules under clinical trials, and the updates were discussed. We have also compiled information on the outcomes from the various endothelial growth factor receptor (EGFR)–TKIs-based nanoformulations from the preclinical and clinical points of view. Aided by an extensive literature search, we propose the challenges and potential opportunities for future research on EGFR–TKIs-based nanodelivery systems.


Endocrinology ◽  
1996 ◽  
Vol 137 (10) ◽  
pp. 4427-4434 ◽  
Author(s):  
T Sasaoka ◽  
M Ishiki ◽  
T Sawa ◽  
H Ishihara ◽  
Y Takata ◽  
...  

2021 ◽  
Vol 22 (18) ◽  
pp. 9781
Author(s):  
Hideki Ohashi ◽  
Keiichiro Nishida ◽  
Aki Yoshida ◽  
Yoshihisa Nasu ◽  
Ryuichi Nakahara ◽  
...  

We investigated the effects of adipose-derived extract (AE) on cultured chondrocytes and in vivo cartilage destruction. AE was prepared from human adipose tissues using a nonenzymatic approach. Cultured human chondrocytes were stimulated with interleukin-1 beta (IL-1β) with or without different concentrations of AE. The effects of co-treatment with AE on intracellular signaling pathways and their downstream gene and protein expressions were examined using real-time PCR, Western blotting, and immunofluorescence staining. Rat AE prepared from inguinal adipose tissues was intra-articularly delivered to the knee joints of rats with experimental osteoarthritis (OA), and the effect of AE on cartilage destruction was evaluated histologically. In vitro, co-treatment with IL-1β combined with AE reduced activation of the p38 and ERK mitogen-activated protein kinase (MAPK) pathway and nuclear translocation of the p65 subunit of nuclear factor-kappa B (NF-κB), and subsequently downregulated the expressions of matrix metalloproteinase (MMP)-1, MMP-3, MMP-13, a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)-4, IL-6, and IL-8, whereas it markedly upregulated the expression of IL-1 receptor type 2 (IL-1R2) in chondrocytes. Intra-articular injection of homologous AE significantly ameliorated cartilage destruction six weeks postoperatively in the rat OA model. These results suggested that AE may exert a chondroprotective effect, at least in part, through modulation of the IL-1β-induced inflammatory signaling pathway by upregulation of IL-1R2 expression.


2006 ◽  
Vol 18 (6) ◽  
pp. 655 ◽  
Author(s):  
Megan J. Wallace ◽  
Alison M. Thiel ◽  
Andrea M. Lines ◽  
Graeme R. Polglase ◽  
Foula Sozo ◽  
...  

Increased fetal lung expansion induces lung growth, cell differentiation and extracellular matrix remodelling, although the mechanisms involved are unknown. Platelet-derived growth factor (PDGF)-B, vascular endothelial growth factor (VEGF) and insulin-like growth factor (IGF)-II are mitogens activating the mitogen-activated protein kinase (MAPK) pathway, whereas transforming growth factor (TGF)-β1 induces differentiation and extracellular matrix remodelling. In the present study, we investigated the mRNA levels of PDGF-B, VEGF, IGF-II and TGF-β1, as well as active MAPK levels, during increased fetal lung expansion induced by tracheal obstruction (TO) in sheep for 0 (controls), 36 h or 2, 4, or 10 days (n = 5 in each group). The 3.7-kb VEGF transcript increased by 30% (P < 0.05) at 36 h TO. The expression of PDGF-B decreased by approximately 25% (P < 0.01) at 2–10 days TO. In contrast, TGF-β1 mRNA increased by 96% (P < 0.05) at 10 days TO, when bioactive TGF-β1 decreased by 55% (P < 0.05). Insulin-like growth factor-II mRNA tended to increase at 10 days TO (37% above controls; P = 0.07), whereas mRNA for its receptor, IGF1R, was reduced by TO. There was no change in active MAPK levels preceding or at the time of a TO-induced 800% increase in cell proliferation. We conclude that VEGF is likely to promote expansion-induced endothelial cell proliferation, but the mechanisms underlying expansion-induced proliferation of fibroblasts and alveolar epithelial cells are unlikely to be mediated by increases in PDGF-B or IGF-II expression or activation of the MAPK pathway.


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