Retinoids Enhance the Expression of Cathelicidin Antimicrobial Peptide during Reactive Dermal Adipogenesis

A subset of dermal fibroblasts undergo rapid differentiation into adipocytes in response to infection and acutely produce the cathelicidin antimicrobial peptide gene Camp Vitamin A and other retinoids inhibit adipogenesis yet can show benefit to skin disorders, such as cystic acne, that are exacerbated by bacteria. We observed that retinoids potently increase and sustain the expression of Camp in preadipocytes undergoing adipogenesis despite inhibition of markers of adipogenesis, such as Adipoq, Fabp4, and Rstn Retinoids increase cathelicidin in both mouse and human preadipocytes, but this enhancement of antimicrobial peptide expression did not occur in keratinocytes or a sebocyte cell line. Preadipocytes undergoing adipogenesis more effectively inhibited growth of Staphylococcus aureus when exposed to retinoic acid. Whole transcriptome analysis identified hypoxia-inducible factor 1-α (HIF-1α) as a mechanism through which retinoids mediate this response. These observations uncouple the lipid accumulation element of adipogenesis from the innate immune response and uncover a mechanism, to our knowledge previously unsuspected, that may explain therapeutic benefits of retinoids in some skin disorders.

Cellulite: an evidence-based review

BACKGROUND

Cellulite is a multifactorial condition that is present in 80-90 % of post-pubertal women. Despite its high prevalence, it remains a major cosmetic concern for women. A wide range of products and treatments for cellulite reduction is available; however, no systematic review has been performed so far to evaluate the efficacy of the available treatment options for cellulite.

OBJECTIVE

The objective of this review is to provide a systematic evaluation of the scientific evidence of the efficacy of treatments for cellulite reduction.

METHODS

This systematic review followed the PRISMA guidelines for reporting systematic reviews and meta-analyses. Only original articles in English or German reporting data on the efficacy of cellulite treatments from in vivo human studies were considered. In total, 67 articles were analyzed for the following information: therapy, presence of a control group, randomization, blinding, sample size, description of statistical methods, results, and level of evidence.

RESULTS

Most of the evaluated studies, including laser- and light-based modalities, radiofrequency, and others had important methodological flaws; some did not use cellulite severity as an endpoint or did not provide sufficient statistical analyses. Of the 67 studies analyzed in this review, only 19 were placebo-controlled studies with randomization. Some evidence for potential benefit was only seen for acoustic wave therapy (AWT) and the 1440 nm Nd:YAG minimally invasive laser.

CONCLUSION

This article provides a systematic evaluation of the scientific evidence of the efficacy of treatment for cellulite reduction. No clear evidence of good efficacy could be identified in any of the evaluated cellulite treatments.

Retinoids and nuclear retinoid receptors in white and brown adipose tissues: physiopathologic aspects

Vitamin A, ingested either as retinol or β-carotene from animal- or plant-derived foods respectively, is a nutrient essential for many biological functions such as embryonic development, vision, immune response, tissue remodeling, and metabolism. Its main active metabolite is all

Effect of cosmetic ingredients as anticellulite agents: synergistic action of actives with in vitro and in vivo efficacy

BACKGROUND

The pathophysiology of cellulite involves changes in the subcutaneous adipose layer and the extracellular matrix (ECM) that supports it together with overlying dermal layer. Cellular mechanisms governing cellulite are not fully understood. However, it is accepted that changes include enhanced lipogenesis, decreased lipolysis, and increased lipid storage within the adipocytes as well as changes in the dermal architecture.

AIM

In our studies the ability of cosmetic agents Furcellaria lumbricalis, Fucus vesiculosus, retinoid, conjugated linoleic acid (CLA), and a glaucine mixture to stimulate in vitro 1) lipolysis in human adipocytes and 2) production of pro-collagen I by fibroblasts was investigated in vitro. The ability of these ingredients to improve cellulite condition in vivo was also determined.

PATIENTS/METHODS

Mature adipocytes and 'aged' fibroblasts were used for in vitro studies. The assessment of cellulite in vivo was performed by dermatological grading and ultrasound measurements.

RESULTS

Mature adipocytes treated with combined actives resulted in a significant synergistic increase in free glycerol release. On "aged" fibroblasts, combined treatment of F. vesiculosus and F. lumbricalis stimulated pro-collagen I production. CLA increased pro-collagen I production, but the glaucine mixture had no effect. The clinical study demonstrated a significant improvement in cellulite grading by a dermatologist after 8 and 12 weeks vs. vehicle, and ultrasound imaging showed a significant decrease in fat thickness compared with placebo after 12 weeks.

CONCLUSIONS

Our studies revealed a potent cocktail of ingredients that when combined together can act in vitro to markedly improve lipolysis mechanisms and by way of stimulating pro-collagen I can also have an effect on the surrounding extracellular matrix. The in vitro actions of the ingredients were translated in vivo, where a clinical improvement of cellulite condition was observed.