Two Phases, One Strategy

How Blast Longevity Approaches Lung Fibrosis

Pulmonary fibrosis is one of the most difficult conditions in regenerative medicine — not because the biology is mysterious, but because the disease is self-perpetuating. Once TGF-β and activin signaling take hold in the lung, fibroblasts convert to myofibroblasts, collagen accumulates, and the tissue’s own repair machinery starts working against it. Conventional anti-fibrotic drugs slow the decline. They do not reverse it, and they do not address why the lung stopped repairing itself in the first place.

Our approach at Blast Longevity is built around two distinct biological questions, addressed in sequence: how do we soften and reverse the scarring that has already formed? and how do we sustain a lung environment that resists fibrosis going forward? These are not the same problem, and in our clinical experience they are not solved by the same tool. That is why our protocol pairs a short, concentrated phase of PSC-derived exosome therapy with several months of α-Klotho gene therapy support.

Phase One: PSC-Derived Exosomes — Softening Existing Scar Tissue

The first weeks of treatment are about undoing what has already hardened. Pluripotent stem cell (PSC)-derived exosomes are tiny natural messengers, released by the cells, that carry a package of regulatory microRNAs — molecules that tell scar-forming cells to soften, relax, and stop laying down more collagen. Because PSCs share their developmental origin with the lung’s own epithelium, this cargo is unusually well matched to lung tissue specifically.

Two independent research groups have now shown this directly, using exosomes from genuinely pluripotent sources — not the mesenchymal stem cells (MSCs) more commonly studied elsewhere. Exosomes from induced pluripotent stem cells reduced collagen buildup and calmed the inflammatory immune cells that keep fibrosis active.¹ Exosomes from human embryonic stem cells, given from the earliest point of lung injury, cleared already-deposited collagen and restored the architecture of the air sacs themselves.² In both studies, the tissue did not just stop scarring further — it visibly softened and rebuilt.

Three specific microRNAs inside this cargo explain why:

• Let-7d protects the lung’s epithelial lining from converting into the type of cell that drives scar formation in the first place. When let-7 activity is lost, the air sacs begin to thicken and stiffen — restoring it helps keep that lining intact.³
• miR-29b acts as a natural brake on collagen production — but in fibrotic lungs, this brake is largely missing: fibrotic tissue runs low on miR-29b, which is exactly what allows collagen to build up unchecked. PSC exosome cargo replenishes it, restoring the lung’s own braking system rather than introducing something foreign. In research models, restoring miR-29b has both prevented new scarring and actively treated scarring that had already formed.⁴
• miR-200 does something rarer still: it can reverse fibroblasts that have already become scar-producing cells, turning fibrotic tissue back toward a healthier, more pliable state — not just holding the line, but pushing the disease process backward.⁵

This is why exosome therapy comes first in the sequence: PSC exosome cargo works best while the fibrotic process is actively unfolding, giving these microRNAs the clearest opportunity to soften existing scar tissue and interrupt the signals driving new scarring.

Phase Two: α-Klotho — Holding the Terrain

Once the active scarring has been softened, the question changes. Idiopathic pulmonary fibrosis is fundamentally an aging-related disease, and Klotho — the body’s prototypical anti-aging protein — sits close to the center of that biology. As we age, Klotho levels naturally decline, and fibrotic lungs show even lower levels than aging alone would predict.

A large-scale genetic analysis of fibrotic lung tissue — the largest of its kind — singled out Klotho as a master switch sitting upstream of several of the processes that drive fibrosis: fibroblast movement into damaged tissue, TGF-β signaling, and scar-tissue buildup. Klotho levels were found to drop specifically in the fibroblasts of injured lungs, and restoring Klotho calmed all three of these processes at once.⁶

Klotho does this in part by keeping two overactive signals in check: TGF-β and VEGF. TGF-β is the lung’s central “make more scar tissue” signal — Klotho blunts it directly. VEGF is a little more counterintuitive, because VEGF is normally a helpful signal that tells the body to grow new blood vessels; we even use it therapeutically elsewhere in our protocols for exactly that reason. But in a fibrotic lung, VEGF becomes overexpressed and gets swept into the same pathological signaling loop as TGF-β, contributing to the abnormal tissue remodeling rather than healthy vessel growth. In that specific setting, reining VEGF back down — which is what Klotho does — removes one more contributor to ongoing scarring rather than blocking a beneficial process.⁷ Klotho also calms a separate pathway called Wnt/β-catenin signaling, which independently drives the same kind of abnormal lung repair.⁸

And this isn’t only true in the lab. In people, lower Klotho levels in the blood are directly linked to worse lung function — measurable even at the earliest, pre-diagnosis stage of interstitial lung changes, often years before fibrosis is formally diagnosed.⁸ In other words, Klotho decline and lung decline move together in real patients. That relationship is exactly why we treat Klotho as long-term, months-long support rather than a short course: it is addressing the underlying aging-related deficit that made the lung vulnerable to fibrosis in the first place, not just the acute flare-up.

Why the Sequence Matters

This is the biological logic behind pairing a short, intensive exosome phase with sustained Klotho support: exosomes are built to disrupt an active, high-signal fibrotic process, while Klotho is built to sustain a low-fibrotic, pro-repair systemic environment over time. Using Klotho alone skips the acute disruption that exosome cargo is uniquely suited to deliver. Using exosomes alone leaves the underlying aging-related Klotho deficit — the condition that made the lung vulnerable to fibrosis in the first place — unaddressed once the exosome course ends.

Our minicircle gene therapy platform is what makes months of Klotho support practical. Because the vector is backbone-free, CpG-depleted, and episomal, it supports a re-dosing rhythm that can be maintained over an extended period without the immunogenicity concerns associated with older viral delivery systems — which is what allows Klotho to function as sustained foundational support rather than a one-time intervention.

This is the same principle we describe elsewhere as the biological foundation strategy: use the right tool for the right phase of repair, and give the lung both the acute correction and the long-term terrain it needs to hold that correction.

References

1. Exosomes derived from induced pluripotent stem cells suppress M2-type macrophages during pulmonary fibrosis via the miR-302a-3p/TET1 axis. ScienceDirect, 2021.
2. Exosomal miR-17-5p from human embryonic stem cells prevents pulmonary fibrosis by targeting thrombospondin-2. Stem Cell Research & Therapy (PMC10478444), 2023.
3. Let-7 restrains an oncogenic circuit in AT2 cells to prevent fibrogenic cell intermediates in pulmonary fibrosis. bioRxiv, 2024.
4. miR-29 Inhibits Bleomycin-induced Pulmonary Fibrosis in Mice. Molecular Therapy (PMC3369297).
5. Participation of miR-200 in Pulmonary Fibrosis. American Journal of Pathology (PubMed, PMID 22189082), 2011.
6. Klotho antagonizes pulmonary fibrosis through suppressing pulmonary fibroblasts activation, migration, and extracellular matrix production: a therapeutic implication for idiopathic pulmonary fibrosis. PMC7185122.
7. Role of Klotho, an antiaging protein, in pulmonary fibrosis. PubMed, PMID 24894433.
8. Lower levels of α-Klotho in serum are associated with decreased lung function in individuals with interstitial lung abnormalities. Scientific Reports, 2019.