A drug revived the liver's aging filter cells and halved amyloid beta — in aged rats

Edited by Samael A. Tejada, Founder & Editor-in-Chief

Alzheimer's drug development has a 98 percent clinical failure rate, in part because getting drugs into the brain is so hard. This study works the other end of the problem: restore the liver's aging sieve, and let the body's own clearance organ pull amyloid beta down from outside the brain entirely. The result — amyloid halved to youthful levels in two weeks, in rats — is exactly as strong, and exactly as preliminary, as that sentence says.

What are LSECs, and what happens to them with age?

Liver sinusoidal endothelial cells line the liver's blood vessels and are perforated by pores — fenestrations — that let larger molecules in the blood reach hepatocytes, the cells that do most of the liver's clearing work. With normal aging those pores shrink and close (a process called pseudocapillarization), stranding larger molecules in circulation. The USC team built on observations that aging curtails the liver's clearance of amyloid beta, and hypothesized that the closing sieve explains why circulating amyloid beta rises with age.

What did two weeks of cinaciguat do?

Aged rats treated with cinaciguat for two weeks were compared with untreated aged and young control groups. The drug rejuvenated the LSECs — reopening the pores and restoring clearance capacity — and amyloid beta in the treated aged rats was cut in half, dropping to the same levels measured in young rats, while untreated aged rats showed no decrease. The authors describe this as the first demonstration that a drug can fully restore LSEC shape and function including clearance, and the first liver-directed treatment shown to normalize aging-elevated amyloid beta and LDL. LDL was expected to serve as a control, because its particles are small enough not to need the pores; its normalization is what sent the team looking for the cell-to-cell signaling below.

What is the HB-EGF crosstalk the study uncovered?

Cinaciguat activates soluble guanylate cyclase in LSECs. Activated LSECs release heparin-binding EGF-like growth factor (HB-EGF), which acts on neighboring hepatocytes and changes their cell surfaces so they capture more LDL and amyloid beta. With age, LSECs lose the ability to release HB-EGF; cinaciguat restored it. The team is continuing in rats, next testing whether lowering circulating amyloid beta this way translates into measurable protection against Alzheimer's-type outcomes — the step that would turn an elegant clearance result into a disease claim. Corresponding author Laurie DeLeve's own summary is the right calibration: further translational work is needed to see whether the findings point to new therapies.

Where the evidence stands

• Established: Liver sinusoidal endothelial cells are perforated filter cells whose pores shrink with aging, reducing hepatic clearance of larger circulating molecules including amyloid beta; age and liver damage are risk factors for Alzheimer's disease and atherosclerosis in epidemiological data.
• Preliminary: In aged rats (Journal of Biological Chemistry, 2026; DOI 10.1016/j.jbc.2026.113608), two weeks of cinaciguat restored LSEC structure and clearance, halved circulating amyloid beta to young levels, normalized LDL, and acted through an sGC to HB-EGF signaling chain from LSECs to hepatocytes.
• Absent: Human data of any kind, any measurement of mitochondria in this study, any demonstration that lowering blood amyloid beta this way prevents Alzheimer's disease, and any brain outcome.