Efficacy of Topical Losartan in Management of Mammoplasty and Abdominoplasty Scars: A Randomized, Double-Blind Clinical Trial

Profibrotic Subsets of SPP1+ Macrophages and POSTN+ Fibroblasts Contribute to Fibrotic Scarring in Acne Keloidalis

Acne keloidalis is a primary scarring alopecia characterized by longstanding inflammation in the scalp causing keloid-like scar formation and hair loss. Histologically, acne keloidalis is characterized by mixed leukocytic infiltrates in the acute stage followed by a granulomatous reaction and extensive fibrosis in the later stages. To further explore its pathogenesis, bulk RNA sequencing, single-cell RNA sequencing, and spatial transcriptomics were applied to occipital scalp biopsy specimens of lesional and adjacent no-lesional skin in patients with clinically active disease. Unbiased clustering revealed 19 distinct cell populations, including 2 notable populations: POSTN+ fibroblasts with enriched extracellular matrix signatures and SPP1+ myeloid cells with an M2 macrophage phenotype. Cell communication analyses indicated that fibroblasts and myeloid cells communicated by SPP1 signaling networks in lesional skin. A reverse transcriptomics in silico approach identified corticosteroids as possessing the capability to reverse the gene expression signatures of SPP1+ myeloid cells and POSTN+ fibroblasts. Intralesional corticosteroid injection greatly reduced SPP1 and POSTN gene expression as well as acne keloidalis disease activity. Spatial transcriptomics and immunofluorescence staining verified microanatomic specificity of SPP1+ myeloid cells and POSTN+ fibroblasts with disease activity. In summary, the communication between POSTN+ fibroblasts and SPP1+ myeloid cells by SPP1 axis may contribute to the pathogenesis of acne keloidalis.

Corneal fibrosis: From in vitro models to current and upcoming drug and gene medicines

Fibrotic diseases are characterised by myofibroblast differentiation, uncontrolled pathological extracellular matrix accumulation, tissue contraction, scar formation and, ultimately tissue / organ dysfunction. The cornea, the transparent tissue located on the anterior chamber of the eye, is extremely susceptible to fibrotic diseases, which cause loss of corneal transparency and are often associated with blindness. Although topical corticosteroids and antimetabolites are extensively used in the management of corneal fibrosis, they are associated with glaucoma, cataract formation, corneoscleral melting and infection, imposing the need of far more effective therapies. Herein, we summarise and discuss shortfalls and recent advances in in vitro models (e.g. transforming growth factor-β (TGF-β) / ascorbic acid / interleukin (IL) induced) and drug (e.g. TGF-β inhibitors, epigenetic modulators) and gene (e.g. gene editing, gene silencing) therapeutic strategies in the corneal fibrosis context. Emerging therapeutical agents (e.g. neutralising antibodies, ligand traps, receptor kinase inhibitors, antisense oligonucleotides) that have shown promise in clinical setting but have not yet assessed in corneal fibrosis context are also discussed.

A randomised clinical trial study assessing the efficacy of 5% losartan potassium loaded in ethosomal gel to treat human keloids: a trial protocol

BACKGROUND

Keloid is a skin disorder that results from excessive fibrous tissue growth in the area of the initial trauma. Treating keloids can be challenging since the success of various treatments varies from one study to another. Triamcinolone acetonide injection, a standard treatment, can cause undesirable side effects. Meanwhile, the effectiveness of existing topical therapies for keloids is not always reliable. The pro-inflammatory, pro-proliferative, and pro-fibrotic effects of angiotensin II in human skin contribute to keloid formation. Losartan potassium, an angiotensin II blocker, has the potential to act as an anti-keloid agent. Due to the thicker skin structure of a keloid and ease of application, ethosome gel is chosen as a safe and comfortable carrier for losartan potassium, making it a good choice for treating keloids.

METHODS

In this randomised clinical trial, 46 adults with keloids were divided into two treatment groups. One group of 23 participants received 5% losartan potassium loaded in ethosomal gel, while the other group of 23 participants received intralesional injections of 10% triamcinolone acetonide. Over 12 weeks, changes in POSAS 3.0 scores, degree of erythema and pigmentation, surface area, thickness, and pliability of the keloids will be measured at four different times: baseline, 4 weeks, 8 weeks, and 12 weeks. Statistical analysis will be conducted using SPSS software version 24, with a significance level of p < 0.05.

DISCUSSION

Losartan potassium is believed to be beneficial for keloid management because it inhibits the angiotensin II receptor, which plays a role in inflammation, proliferation, and fibrosis. This study examines the efficacy of 5% losartan potassium loaded in ethosomal gel for human keloids.

TRIAL REGISTRATION

Clinicaltrial.gov identifier NCT05893108 . Registered on 7 June 2023.

Effect of angiotensin converting enzyme inhibitors and angiotensin II receptor blockers on need for operative intervention for idiopathic adhesive capsulitis

Background

The exact pathogenesis of idiopathic adhesive capsulitis (IAC) is not fully understood, but an inflammatory profibrotic cascade, largely mediated by transforming growth factor-beta 1 (TGF- β1) has been implicated. Angiotensin II receptor blockers (ARBs) and angiotensin-converting enzyme inhibitors (ACE-Is) both decrease the activity of TGF-β1. The aim of this study was to determine the impact of ACE-Is or ARBs use on the need for operative intervention in IAC.

Methods

This was a retrospective cohort study of patients from a single institutional database with IAC, divided into two cohorts, with and without ACE-I and/or ARB use as the primary exposure and a minimum 2-year follow-up. The primary outcome measured was the incidence of operative intervention including manipulation under anesthesia (MUA) and arthroscopic capsular release (ACR). Additional multivariable logistic regression analysis was performed to evaluate associations between ACE-I/ARB use and likelihood of undergoing an operative procedure.

Results

A total of 17,645 patients met inclusion criteria, with 5424 patients in the ACE-I/ARB cohort and 12,221 in the non-ACE-I/ARB cohort. Overall, 422 (2.4%) patients underwent surgical treatment, 378 (2.1%) ACR, and 74 (0.4%) MUA. There was no significant difference between cohorts in the frequency of surgical procedures or time to procedure since diagnosis. There were no significant differences between individual ACE-Is or ARBs, although Losartan was found to have a trend of decreased rate of intervention (31.7% vs. 36.8%, P = .209) when compared to patients not on losartan that did not reach statistical significance. Patient factors predictive of undergoing MUA/ACR were diabetes (P = .013), obesity (P < .001), and male sex (P < .001). Increasing patient age reduces the likelihood of undergoing operative intervention, with patients aged 50-70 years (P = .022) and age >70 years (P < .001) demonstrating reduced odds as compared to patients aged <30 years.

Conclusion

Patients with IAC have an overall low (2.4%) rate of requiring surgical intervention. While the antifibrotic mechanism of ACE inhibitors and ARBs did not significantly affect the rate of requiring surgical intervention, male gender, obesity, younger age, and diabetes, all increased the risk for operative intervention. Losartan, specifically, may have a disease modifying effect on IAC that should be investigated with larger controlled trials.

Angiotensin Receptor Blockers and Angiotensin-Converting Enzyme Inhibitors Have No Significant Relationship With Postoperative Arthrofibrosis After Shoulder Arthroscopy

Purpose

To determine the effect of perioperative angiotensin II receptor blocker (ARB) or angiotensin-converting enzyme inhibitors (ACEi) on postoperative arthrofibrosis, as defined by requiring manipulation under anesthesia (MUA) or new diagnosis of adhesive capsulitis (AC) following arthroscopic shoulder procedures.

Methods

Patients were retrospectively identified using Current Procedural Terminology surgical billing codes to identify patients who underwent any shoulder arthroscopic procedure at a single urban academic institution from 2012 to 2020 with a minimum 2-year follow-up. Patients were excluded if <30 years old at time of surgery, as these patients rarely use ARB and ACEi medications, or if they had pre-existing AC. Demographics, active medication prescriptions at the time of surgery, and medical comorbidities were recorded. Multivariable logistic regression was performed to determine the effect of ARB/ACEi on subsequent MUA or AC by 90 days, 1 year, and 2 years.

Results

In total, 5,559 patients were included in the final analysis. A majority of the cohort (53.4%) underwent arthroscopic surgery between the ages of 50 to 69 years. Most patients were male (61.8%) and without obesity (67.3%). In total, 18.9% and 15.0% were taking an ARB or ACEi medication perioperatively, respectively. Within 2 years' postoperatively, 51 patients (0.9%) underwent subsequent ipsilateral MUA, and 174 patients (3.1%) developed AC. Patients taking ARBs had a 17.5% rate of postoperative arthrofibrosis within 2-years compared with 19.1% in those not on ARBs, although this difference was not significant (P = .58). Likewise, no significant difference was found between those taking ACEi versus not (15.0% vs 15.0%, P = .99). Individual generic ARB/ACEi subgroup analysis did not demonstrate any significant associations with rate of postoperative arthrofibrosis (P > .05).

Conclusions

ARBs or ACEi did not significantly affect the rate of postoperative arthrofibrosis following shoulder arthroscopy, however female sex, diabetes mellitus, and Black/African American race were associated with an increased rate of necessitating MUA or developing AC within 2 years postoperatively.

Level of Evidence

Level III, retrospective cohort study.

Topical Losartan: Practical Guidance for Clinical Trials in the Prevention and Treatment of Corneal Scarring Fibrosis and Other Eye Diseases and Disorders

Losartan is an angiotensin II receptor blocker (ARB) that impedes transforming growth factor (TGF) beta signaling by inhibiting activation of signal transduction molecule extracellular signal-regulated kinase (ERK). Studies supported the efficacy of topical losartan in decreasing scarring fibrosis after rabbit Descemetorhexis, alkali burn, and photorefractive keratectomy injuries, and in case reports of humans with scarring fibrosis after surgical complications. Clinical studies are needed to explore the efficacy and safety of topical losartan in the prevention and treatment of corneal scarring fibrosis, and other eye diseases and disorders where TGF beta has a role in pathophysiology. These include scarring fibrosis associated with corneal trauma, chemical burns, infections, surgical complications, and persistent epithelial defects, as well as conjunctival fibrotic diseases, such as ocular cicatricial pemphigoid and Stevens-Johnson syndrome. Research is also needed to explore the efficacy and safety of topical losartan for hypothesized treatment of transforming growth factor beta-induced (TGFBI)-related corneal dystrophies (Reis-Bu¨cklers corneal dystrophy, lattice corneal dystrophy type 1, and granular corneal dystrophies type 1 and type 2) where deposited mutant protein expression is modulated by TGF beta. Investigations could also explore the efficacy and safety of topical losartan treatments to reduce conjunctival bleb scarring and shunt encapsulation following glaucoma surgical procedures. Losartan and sustained release drug delivery devices could be efficacious in treating intraocular fibrotic diseases. Dosing suggestions and precautions that should be considered in trials of losartan are detailed. Losartan, as an adjuvant to current treatments, has the potential to augment pharmacological therapeutics for many ocular diseases and disorders where TGF beta plays a central role in pathophysiology.