An Adhesive Peptide Derived from Mussel Protein Alleviates LL37-Induced Rosacea Through Anti-Inflammatory and Anti-Angiogenic Mechanisms

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The title must present the source of the peptide.
The authors' justification of the urgency of conducting the study based on novelty and ‘skin-friendly’ treatments for rosacea is unqualified. 
It is unclear how AdhPep3 interacts with the pathological pathway of rosacea, making it a suitable candidate for its treatment. Similarly, the authors failed to present what makes their in vitro experiment method suitable for studying rosacea experimentally. 
Claims on ‘strengthening skin barrier’ should be limited to the context of the actual experiment conducted. No viable skin model was used in the study; hence, such a claim is unfounded. Further, the effect of AdhPep3 on the transepidermal water loss or skin evaporation model was not determined. 
Authors should describe the limitations of the non-animal model used in the angiogenesis study.

Comments on the Quality of English Language

Revise for clarity.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

I have carefully reviewed the original article entitled: “A Novel Peptide Alleviates LL37-Induced Rosacea via Anti-Inflammatory and Anti-Angiogenic Mechanisms” by Tae Yoon Kim et al.  This manuscript presents a well-executed in vitro study evaluating the anti-inflammatory and anti-angiogenic potential of a newly developed adhesive peptide (AdhPep3) in models of rosacea. The study is comprehensive, methodologically sound, and offers novel insights into peptide-based therapeutic approaches for inflammatory skin conditions. The manuscript is generally well-written and logically structured. However, several critical issues need to be addressed to enhance the scientific rigor and translational relevance of the study.

Major Comments

1. The manuscript would be significantly strengthened by including an in vivo model (e.g., rosacea-like mouse model) to validate the therapeutic relevance and safety of AdhPep3.
2. There is insufficient discussion on peptide delivery, skin stability, degradation, and pharmacokinetics. These are critical for clinical translation and must be addressed, even if only speculatively.
3. The absence of control peptides (e.g., scrambled or mutant sequences) makes it difficult to determine if AdhPep3's effects are specific to its adhesion properties. Including such controls would enhance the mechanistic validity of the findings.
4. The discussion section should begin with a concise summary of the main findings. Also, limitations of the study must be acknowledged (in the last paragraph).
5. The reasoning behind the 2-hour pretreatment with AdhPep3 prior to LL37 stimulation should be justified with supporting literature. Additionally, why was the protocol designed this way and not in reverse (LL37 first, followed by AdhPep3)?
6. The statement that "adhesive peptide can be a safer and more precise therapeutic agent for rosacea compared to current therapies due to its high biocompatibility and target specificity. Ultimately, this peptide drug can significantly improve the quality of life of patients with rosacea." is speculative and not supported by in vivo or clinical data. The authors are advised to rephrase all such claims throughout the manuscript to reflect the potential therapeutic implications, rather than definite outcomes.
7. The manuscript lacks a clear rationale for the selection of AdhPep peptides. The authors should explain on what basis AdhPep was chosen as a therapeutic candidate. Were there previous studies indicating its relevance (e.g., ECM mimicry, integrin binding)? Provide citations or reasoning.
8. The manuscript states peptide purity but lacks any physicochemical characterization (e.g., mass spectrometry confirmation, solubility, charge, or stability assessments). Such data are essential to validate peptide integrity and functional reproducibility.
9. The table listing AdhPep1–3 sequences lacks context. The authors should indicate what these sequences represent and provide a rationale for their selection and their functional relevance.

Minor Comments

1. Lines 50–53: While the manuscript states the location of LL37 action, it omits a description of its mechanism of action via TLR2, which is emphasized in the graphical abstract. This should be elaborated in the main text to maintain consistency.
2. Although “*” and “#” are explained in the Methods, they must be redefined in each figure legend for clarity, as figure interpretations should be understandable independently from the main text.
3. The authors must provide the ethics committee approval number for the experiments conducted.
4. The authors should clarify whether HaCaT cells have been previously used in rosacea-related or similar peptide-response studies to strengthen the model’s relevance.
5. Line 87: Remove the unnecessary dot after “99%”.
6. Section Title: Change the title of Section 2 to "Materials and Methods" for consistency with standard scientific formatting.
7. Figure Software: Authors should state the software used to generate figures.
8. Use of HUVEC Cells: Clarify the rationale for using HUVECs in the context of rosacea pathophysiology.
9. Discussion – Final Paragraph (Lines 483–490): This paragraph should be moved to the Conclusion section and appropriately integrated.
10. Guidelines Citation: In the Introduction, refer more specifically to current rosacea treatment guidelines (e.g., PMID: 32035944) to contextualize the unmet clinical need.
11. Typographical and Formatting Errors: Minor grammatical inconsistencies, font variations, and spacing issues were noted in figures and references. A careful proofreading is recommended.

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

1. add study design
2. add paragraph on peptide used in the study and rationale on its use
3. aim is not for results, please rewrite the end of the introduction
4. section 2.2 need to be described in depth
5. table 1 - explain in detail, or put abbreviations under table
6. improve quality of all figures
7. start discussion with your main findings
8. compare your results with similar studies
9. please add limitation section

interesting study, but manuscript must be improved according to comments in order to add to the body of literature in the field of rosacea

Author Response

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Author Response File: Author Response.docx

Reviewer 4 Report

Comments and Suggestions for Authors

This study aimed to evaluate the therapeutic potential of an adhesive peptide AdhPep3 (AYDPGYK) for rosacea treatment using well-established in vitro models for studying rosacea-related inflammation and vascular changes (in HaCaT human keratinocytes and HUVEC human umbilical vein endothelial cells treated with LL-37). This study is very well designed. Contemporary methods were used, and many novel and significant results have been obtained. The manuscript is also well-structured and clearly written. Therefore, I support it to be published after minor revisions.

In my opinion, the title should be more specific and include the name of the specific adhesive peptide (the term “a novel peptide” is too general).

Although being well-established and widely used, this in vitro rosacea model has several limitations as well, since it lacks immune cell involvement and does not fully represent the chronic or multi-factorial nature of rosacea. It should be emphasized in the manuscript as a limitation of the study.

Since dermal application of this adhesive peptide is intended, the challenges of utilizing peptides in dermal products should be emphasized in the Introduction section, such as stability issues or poor skin penetration.

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Sufficient revision was made.

Reviewer 2 Report

Comments and Suggestions for Authors

Authors have addressed all of my comments adequately, and the manuscript is sufficiently improved.