Pleiotropic Effect of Hormone Insulin-Like Growth Factor-I in Immune Response and Pathogenesis in Leishmaniases

Abstract

Leishmaniases are diseases caused by several Leishmania species, and many factors contribute to the development of the infection. Because the adaptive immune response does not fully explain the outcome of Leishmania infection and considering that the initial events are crucial in the establishment of the infection, we investigated one of the growth factors, the insulin-like growth factor-I (IGF-I), found in circulation and produced by different cells including macrophages and present in the skin where the parasite is inoculated. Here, we review the role of IGF-I in leishmaniasis experimental models and human patients. IGF-I induces the growth of different Leishmania species in vitro and alters the disease outcome increasing the parasite load and lesion size, especially in L. major- and L. amazonensis-infected mouse leishmaniasis. IGF-I affects the parasite interacting with the IGF-I receptor present on Leishmania. During Leishmania-macrophage interaction, IGF-I acts on the arginine metabolic pathway, resulting in polyamine production both in macrophages and Leishmania. IGF-I and cytokines interact with reciprocal influences on their expression. IL-4 is a hallmark of susceptibility to L. major in murine leishmaniasis, but we observed that IGF-I operates astoundingly as an effector element of the IL-4. Approaching human leishmaniasis, patients with mucosal, disseminated, and visceral diseases presented surprisingly low IGF-I serum levels, suggesting diverse effects than parasite growth. We observed that low IGF-I levels might contribute to the inflammatory response persistence and delayed lesion healing in human cutaneous leishmaniasis and the anemia development in visceral leishmaniasis. We must highlight the complexity of infection revealed depending on the Leishmania species and the parasite’s developmental stages. Because IGF-I exerts pleiotropic effects on the biology of interaction and disease pathogenesis, IGF-I turns up as an attractive tool to explore biological and pathogenic processes underlying infection development. IGF-I pleiotropic effects open further the possibility of approaching IGF-I as a therapeutical target.

miR-548d-3p Alters Parasite Growth and Inflammation in Leishmania (Viannia) braziliensis Infection

“…Our in-silico predictions also showed that some of the altered miRNAs targets the IGF-I signaling pathway. The role of this hormone in Leishmania infection has been long studied with pleiotropic effect in innate and adaptive immune response and pathogenesis in leishmaniases ( Reis et al., 2021 ).…”

miR-548d-3p Is Up-Regulated in Human Visceral Leishmaniasis and Suppresses Parasite Growth in Macrophages

“…Among factors leading to the development of active disease, an immunosuppressive state resulting from either protein-energy malnutrition ( Malafaia, 2009 ) or HIV infection ( Lindoso et al., 2014 ) rank highest. However, participation of other factors gains evidence, including lipoprotein and lipoprotein fraction levels ( Carvalho et al., 2014 ) and growth factors ( Reis et al., 2021 ), and inhibition of secretion of pro-inflammatory cytokines and chemokines ( Tasew et al., 2021 ), along with alterations in the adaptive immune response ( Saporito et al., 2013 ; Palacios et al., 2021 ).…”

Evaluating the Safety and Efficacy of Topical Insulin for Ocular Disease: A Systematic Review

“…The insulin pleiotropic effects extend beyond glycemic control, exhibiting growth factor-like activity. 21 This translates to enhanced keratinocyte migration, fibroblast proliferation, and extracellular matrix protein deposition, ultimately promoting tissue regeneration. Furthermore, topical insulin modulates the inflammatory milieu, influencing the release of pro- and anti-inflammatory cytokines to orchestrate a balanced healing response.…”