Angiotensin 1-7 and Brain Natriuretic Peptide reversed inflammation, fibrosis, and hypertrophy in kidney and vascular cells damaged by Angiotensin II, by blocking the TLR4 signaling pathway.
TLR4 pathway reversedBoth Ang 1-7 and BNP significantly inhibited the TLR4-mediated inflammatory cascade triggered by Angiotensin II, reversing markers of fibrosis, hypertrophy, and inflammation in kidney and vascular cells.
What the researchers found
The peptides Angiotensin 1-7 (Ang 1-7) and Brain Natriuretic Peptide (BNP) significantly reduced TLR4-mediated injury in renal and vascular smooth muscle cells stimulated by Angiotensin II. Specifically, these peptides reversed the upregulation of inflammation, fibrosis, and hypertrophy markers caused by Ang II, and prevented the harmful phenotypic switch in vascular smooth muscle cells.
The protective effects operated through inhibition of the TLR4 signaling pathway, a key driver of end-organ damage in hypertension.
Why it matters
Hypertension causes progressive damage to kidneys and blood vessels, partly through Angiotensin II activating inflammatory pathways. This study identifies two natural peptides — Ang 1-7 and BNP — that can block this damage at a key signaling checkpoint (TLR4). If these findings translate beyond cell studies, peptide-based therapies could offer a new approach to preventing the organ damage that makes hypertension so dangerous.
How the study worked
Researchers used three cell types — renal epithelial cells (RECs), renal fibroblasts (RFbs), and primary vascular smooth muscle cells (VSMCs) — to model organ damage caused by Angiotensin II. They measured gene expression of TLR4 and its downstream markers via qPCR, and assessed inflammatory, hypertrophic, and fibrotic markers using qPCR and immunocytochemistry, with and without Ang 1-7 and BNP treatment.
Who was studied
Rat-derived renal epithelial cells, renal fibroblasts, and primary vascular smooth muscle cells
What this study cannot tell us
This is an in vitro (cell culture) study only — no animal or human experiments were conducted. The protective effects observed in isolated cells may not directly translate to whole-organ or whole-body responses. Dosing, timing, and delivery challenges for clinical use are not addressed.
How to read the evidence
This is an in vitro cell culture study, the earliest stage of preclinical research. While it identifies a promising mechanism, the findings have not been validated in animal models or human trials.
When this study was published
Published in 2025, this is a very recent study exploring a novel peptide-based approach to hypertension-related organ protection.
The bigger picture
Hypertension-related organ damage is a leading cause of kidney failure and cardiovascular disease. Current treatments focus on lowering blood pressure, but don't fully prevent end-organ damage. This research explores whether targeting the inflammatory TLR4 pathway with natural peptides could add a protective layer — potentially complementing blood pressure medications to better preserve organ function.
Questions still open
- Will Ang 1-7 and BNP show the same protective effects in animal models of hypertension?
- Could these peptides be developed into drugs that prevent kidney damage in hypertensive patients?
- How do the protective mechanisms of Ang 1-7 and BNP compare to existing blood pressure medications?
Common questions
What is the TLR4 pathway and why does it matter in hypertension?
What are Angiotensin 1-7 and BNP?
Read the original research
Therapeutic Peptides Mitigates TLR4 Pathway Activation by Ang II in Renal and Vascular Smooth Muscle Cells.
Journal of biochemical and molecular toxicology, 39(11), e70579
Citation
Venkadakrishnan, Jegadheeswari; Vemana, Anusha; Ghatage, Trupti; Vesmaker, Kushal; Bhat, Audesh; Jadhav, Kirtikumar B; Dhar, Arti. (2025). Therapeutic Peptides Mitigates TLR4 Pathway Activation by Ang II in Renal and Vascular Smooth Muscle Cells.. Journal of biochemical and molecular toxicology, 39(11), e70579. https://doi.org/10.1002/jbt.70579