LL-37 Peptide Heals Diabetic Wounds by Activating Cellular Cleanup Through the TFEB-Autophagy Pathway

The antimicrobial peptide LL-37 accelerated wound healing in diabetic mice by switching on TFEB-dependent autophagy, a cellular cleanup process that promotes skin cell migration.

Xi, Liuqing et al.·Peptides·2024·Preliminary Evidenceanimal study
RPEP-09552Animal studyPreliminary Evidence2024RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
animal study
Evidence
Preliminary Evidence
Sample
N=N/A (animal study)
Participants
Diabetic mice with wound models

What This Study Found

LL-37 accelerated diabetic wound healing by activating TFEB nuclear translocation, which upregulated autophagy markers ATG5, ATG7, and BECN1. Blocking autophagy or TFEB reversed LL-37's healing effects.

Key Numbers

LL-37 activated TFEB and downstream autophagy markers. Blocking autophagy reduced LL-37's healing benefits in diabetic wound models.

How They Did This

Full-thickness wound closure model in diabetic mice treated with LL-37 and/or autophagy inhibitor 3-MA. In vitro keratinocyte migration assays under high glucose conditions. TFEB activation measured by western blot and immunofluorescence; TFEB knockdown confirmed mechanism.

Why This Research Matters

Diabetic wound healing is one of the most costly and common complications of diabetes, often leading to amputation. Understanding that LL-37 works through autophagy opens up new therapeutic approaches — either LL-37-based wound treatments or drugs that activate the same TFEB/autophagy pathway.

The Bigger Picture

LL-37 is one of the most studied human antimicrobial peptides, with known antimicrobial, anti-inflammatory, and pro-healing properties. Pinpointing autophagy as a key mechanism adds scientific precision to therapeutic development. Since autophagy declines with age and in diabetes, treatments that restore it could address the root cause of impaired healing rather than just treating symptoms.

What This Study Doesn't Tell Us

Mouse study — diabetic mouse wounds differ from human chronic diabetic ulcers, which involve more complex vascular and neuropathic factors. The relative contribution of autophagy versus LL-37's antimicrobial and anti-inflammatory activities wasn't fully quantified.

Questions This Raises

  • ?Would topical LL-37 application be effective for human diabetic wound healing in clinical trials?
  • ?Could other autophagy activators substitute for LL-37 in promoting diabetic wound healing?
  • ?Does the TFEB-autophagy pathway also explain LL-37's healing effects in non-diabetic wounds?

Trust & Context

Key Stat:
TFEB-dependent autophagy LL-37's wound-healing mechanism works by activating this cellular cleanup pathway, with three key autophagy genes (ATG5, ATG7, BECN1) upregulated
Evidence Grade:
Preliminary evidence from animal and in vitro experiments. The mechanism is well-characterized but has not been validated in human clinical trials.
Study Age:
Published in 2024; represents current understanding of LL-37's wound-healing mechanisms.
Original Title:
Cathelicidin LL-37 promotes wound healing in diabetic mice by regulating TFEB-dependent autophagy.
Published In:
Peptides, 175, 171183 (2024)
Database ID:
RPEP-09552

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study
What do these levels mean? →

Frequently Asked Questions

What is LL-37 and is it available as a treatment?

LL-37 is a naturally occurring human antimicrobial peptide — part of your body's innate immune defense. It's not currently available as an approved wound treatment, but it's being actively researched for wound care, infections, and skin conditions.

Why do diabetic wounds heal so poorly?

High blood sugar impairs multiple healing processes: it reduces blood flow, damages nerves (so injuries go unnoticed), weakens immune responses, and disrupts cellular processes like autophagy. This study shows that restoring autophagy through LL-37 can overcome some of these barriers.

Read More on RethinkPeptides

Cite This Study

RPEP-09552·https://rethinkpeptides.com/research/RPEP-09552

APA

Xi, Liuqing; Du, Juan; Xue, Wen; Shao, Kan; Jiang, Xiaohong; Peng, Wenfang; Li, Wenyi; Huang, Shan. (2024). Cathelicidin LL-37 promotes wound healing in diabetic mice by regulating TFEB-dependent autophagy.. Peptides, 175, 171183. https://doi.org/10.1016/j.peptides.2024.171183

MLA

Xi, Liuqing, et al. "Cathelicidin LL-37 promotes wound healing in diabetic mice by regulating TFEB-dependent autophagy.." Peptides, 2024. https://doi.org/10.1016/j.peptides.2024.171183

RethinkPeptides

RethinkPeptides Research Database. "Cathelicidin LL-37 promotes wound healing in diabetic mice b..." RPEP-09552. Retrieved from https://rethinkpeptides.com/research/xi-2024-cathelicidin-ll37-promotes-wound

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.