10.1371/journal.pone.0034313.g005
Linda Karlsson-Lindahl
Linda
Karlsson-Lindahl
Linnéa Schmidt
Linnéa
Schmidt
David Haage
David
Haage
Caroline Hansson
Caroline
Hansson
Magdalena Taube
Magdalena
Taube
Emil Egeciouglu
Emil
Egeciouglu
Ying-xia Tan
Ying-xia
Tan
Therese Admyre
Therese
Admyre
John-Olov Jansson
John-Olov
Jansson
Israel Vlodavsky
Israel
Vlodavsky
Jin-Ping Li
Jin-Ping
Li
Ulf Lindahl
Ulf
Lindahl
Suzanne L. Dickson
Suzanne
L. Dickson
Proposed effects of heparanase on MC4R signaling.
Public Library of Science
2012
heparanase
mc4r
2012-03-27 01:02:21
Figure
https://plos.figshare.com/articles/figure/_Proposed_effects_of_heparanase_on_MC4R_signaling_/333741
<p>HS chains of a cell-surface HSPG serve as co-receptors for AgRP, and at the same time preclude access of α-MSH to the MC4R. <i>(Left panel)</i> In the absence of heparanase (<i>Hpa-</i>ko) the HS chains remain intact, resulting in continuous AgRP-induced activation of MC4R, thus promoting food consumption, fat accumulation, and a positive energy balance. Under these conditions α-MSH signaling is severely restricted. <i>(Right panel)</i> HS chains are degraded by overexpressed heparanase (<i>Hpa-</i>tg), thus rendering the MC4R accessible to α-MSH, whereas AgRP devoid of its HS co-receptor is unable to engage the MC4R and thus remains inactive. This setting explains the acute effects of ICV-injected heparanase that lead to transient yet drastic reduction in feeding. However, it is also compatible with the long-term effects of transgenic heparanase expression that shift energy balance toward increased loss of body fat and compensatory up-regulation of appetite.</p>