Polythiol-Containing, Recombinant Mannosylated-Albumin Is a Superior CD68⁺/CD206⁺Kupffer Cell–Targeted Nanoantioxidant for Treatment of Two Acute Hepatitis Models

Abstract

Since reactive oxygen species (ROS) derived from Kupffer cells (KC), especially CD681 KC, play a key role in the induction of hepatic oxidative stress and injuries, we developed a polythiolatedand mannosylated human serum albumin (SH-Man-HSA), which functions as a novel nanoantioxidant for delivering thiol to CD68 1 KC. In vitro electron paramagnetic resonance coupled with pharmacokinetics and immunohistochemical studies showed that SH-Man-HSA possessed powerful radical-scavenging activity and rapidly and selectively delivered thiols to the liver via mannose receptor (CD206) on CD68 1 cells. SH-Man-HSA significantly improved the survival rate of concanavalin-A (Con-A)-treated mice. Moreover, SH-Man-HSA exhibited excellent hepatoprotective functions, not by decreasing tumor necrosis factor or interferon-g production that is closely associated with Con-A-induced hepatitis, but by suppressing ROS production.Interestingly, the protective effect of SH-Man-HSA was superior to N-acetyl cysteine (NAC). This could be attributed to the difference in the inhibition of hepatic oxidative stress between the two antioxidants depending on their potential for thiol delivery to the liver. Similar results were also observed for acetaminophen (APAP)-induced hepatopathy models. Flow cytometric data further confirmed that an increase in F4/80 1 /ROS 1 cells was dramatically decreased by SH-Man-HSA. The administration of SH-Man-HSA at 4 hours following a Con-A or APAP injection also exhibited a profound hepatoprotective action against these hepatitis models, whereas this was not observed for NAC. It can be concluded therefore that SH-Man-HSA has great potential for use in a rescue therapy for hepatopathy as a nanoantioxidant because of its ability to efficiently and rapidly deliver thiols to CD68

Repeated Administration of Kupffer Cells-Targeting Nanoantioxidant Ameliorates Liver Fibrosis in an Experimental Mouse Model

“…We recently developed a recombinant neoglyco-human serum albumin (Man-HSA) which possesses a bulky sugar chain consisting of approximately 12 mannose residues that are linked to human serum albumin (HSA) using site-directed mutagenesis and an expression system by pichia pastoris. 20) Our pharmacokinetic experiment in mice showed that more than 60% of the Man-HSA migrated to the liver after its intravenous administration. 20) In addition, we verified that Man-HSA functions as a CD68 + Kupffer cell-targeting drug carrier that is mediated by the mannose receptor C type 1 (CD206).…”

“…20) Our pharmacokinetic experiment in mice showed that more than 60% of the Man-HSA migrated to the liver after its intravenous administration. 20) In addition, we verified that Man-HSA functions as a CD68 + Kupffer cell-targeting drug carrier that is mediated by the mannose receptor C type 1 (CD206). 21) More recently, we developed a Kupffer cell-targeting nanoantioxidant, namely polythiolated and mannosylated human serum albumin (SH-Man-HSA), by loading Man-HSA with poly-thiol groups (7.5 mol thiol/mol Man-HSA).…”

“…SH-Man-HSA Preparation Man-HSA was expressed and purified according to previously reported procedures. 20,21) SH-Man-HSA was synthesized using methods developed by us, in which the moiety of thiol groups conjugated to Man-HSA was determined to be 7.5 mol thiol/mol Man-HSA. 21) SH-Man-HSA and N-Acetylcysteine Administrations SH-Man-HSA or N-acetylcysteine (comparative drug) were dissolved in warm saline and administered to the mice (i.v.)…”

Potential Use of Biological Proteins for Liver Failure Therapy

“…Taking advantage of this liver-specific distribution characteristic, we succeeded in using this highly Man-rHSA as a nitric oxide (NO) carrier in the treatment of hepatic ischemia/reperfusion injury [ 10 ]. Interestingly, Man-rHSA was selectively targeted to mannose receptors (CD206 + ) on CD68 + Kupffer cells [ 11 ]. This means that Man-rHSA has great potential for use as a drug carrier for hepatopathy related to reactive oxygen species (ROS) because CD68 + Kupffer cells can produce relatively high levels of ROS, which play a major role in the progression of liver pathologic conditions [ 12 ].…”

“…This means that Man-rHSA has great potential for use as a drug carrier for hepatopathy related to reactive oxygen species (ROS) because CD68 + Kupffer cells can produce relatively high levels of ROS, which play a major role in the progression of liver pathologic conditions [ 12 ]. In fact, polythiolated- and mannosylated-rHSA (SH-Man-rHSA) showed excellent hepatoprotective action against both concanavalin A-induced and acetaminophen-induced hepatitis [ 11 ].…”