Jump to content

Cause for rosacea?


Recommended Posts

  • Root Admin

MAC Members,

Please comment on this news item that was just released.

In major newspapers across the country they are saying scientists have found the cause of rosacea. For instance the Los Angeles Times, US News and World Report, the Washington Post, UCSD News and Medical News Today. The abstract is already published on PubMed.

Here is the Abstract

Increased serine protease activity and cathelicidin promotes skin inflammation in rosacea

Kenshi Yamasaki, Anna Di Nardo, Antonella Bardan, Masamoto Murakami, Takaaki Ohtake, Alvin Coda1, Robert A Dorschner1, Chrystelle Bonnart, Pascal Descargues, Alain Hovnanian, Vera B Morhenn & Richard L Gallo

Nature Medicine, 5 August 2007 | doi:10.1038/nm1616; http://www.nature.com [type in rosacea in the search box]

Acne rosacea is an inflammatory skin disease that affects 3% of the US population over 30 years of age and is characterized by erythema, papulopustules and telangiectasia1, 2, 3. The etiology of this disorder is unknown, although symptoms are exacerbated by factors that trigger innate immune responses, such as the release of cathelicidin antimicrobial peptides4. Here we show that individuals with rosacea express abnormally high levels of cathelicidin in their facial skin and that the proteolytically processed forms of cathelicidin peptides found in rosacea are different from those present in normal individuals. These cathelicidin peptides are a result of a post-translational processing abnormality associated with an increase in stratum corneum tryptic enzyme (SCTE) in the epidermis. In mice, injection of the cathelicidin peptides found in rosacea, addition of SCTE, and increasing protease activity by targeted deletion of the serine protease inhibitor gene Spink5 each increases inflammation in mouse skin. The role of cathelicidin in enabling SCTE-mediated inflammation is verified in mice with a targeted deletion of Camp, the gene encoding cathelicidin. These findings confirm the role of cathelicidin in skin inflammatory responses and suggest an explanation for the pathogenesis of rosacea by demonstrating that an exacerbated innate immune response can reproduce elements of this disease.

1. Division of Dermatology, University of California, San Diego, and VA San Diego Health Care System, 3350 2. La Jolla Village Drive, San Diego, California 92161, USA.

3. Department of Dermatology, Asahikawa Medical College, Asahikawa 078-8510, Japan.

4. Department of Medicine, Asahikawa Medical College, 2-1-1-1 Midorigacka Hidashi, Asahikawa 078-8510, Japan.

5. INSERM, U563, Toulouse F-31000, France.

UniversitÈ Paul-Sabatier, Toulouse F-31000, France.

6. CHU Toulouse, Department of Genetics, Place du Dr. Baylac, Toulouse F-31000, France.

Link to comment
Share on other sites

  • MAC Member

Dr. Gallo has done some very interesting work in innate immunity, and this is no exception. Definitely warrants some follow-up and confirmatory studies. However, it's important not to confuse "associated finding" with "cause". There is no end to literature linking the latest inflammatory mediator with a clinical disease. They rarely hold up to the test of time as being truly significant.

-David Jones

Link to comment
Share on other sites

  • Guests

The following are replies by email to this topic:

From: Jenny Sun, M.D.

Subject: Re: Fwd: RRDi MAC Members Question

Date: August 7, 2007 6:16:40 AM HST

To: brady

Dear Mr. Barrows,

Rosacea has different subtypes. It is likely that there are many causes to each subtypes, and involves multiple inflammatory mediators. It is great that the authors of this article have provided evdience that cathelicidin is possibilly one of them in murine skin. Thanks, Jenny


From: Sandra Cremers, M.D.

Subject: RE: RRDi MAC Members Question

Date: August 7, 2007 7:58:06 AM HST

To: director@irosacea.org

Hi Brady,

Hope you are well.

I've been looking into angiogenesis and rosacea & do not know enough about serine protease to comment at this time.



From: Raymond Peat, Ph.D

Subject: Re: RRDi MAC Members Question

Date: August 8, 2007 1:52:33 PM HST

To: director@irosacea.org

Things that cause inflammation, such as bacterial endotoxin, stimulate the defensive formation of proteases and cathelicidin, so it doesn't seem productive to say that "too much" of those defensive proteins is the cause of rosacea. Isn't it a little like saying that pus is the cause of boils?

Nutritional deficiencies lead to excessive exposure to endotoxin and nitric oxide, and the associated factors that cause vascular leakiness, vasodilation, angiogenesis, stimulation of fibroblast growth and collagen production. Medical people who are willing to talk about the antiinflammatory action of antibiotics seem to be unaware of the antiinflammatory effects of many simple essential nutrients, such as niacinamide, riboflavin, and glycine, or of the natural antiinflammatory hormones that are consistently deficient in the inflammatory-"autoimmune" diseases.

Acta Anaesthesiol Scand. 2003 Feb;47(2):213-20.

Effects of human cathelicidin antimicrobial peptide LL-37 on lipopolysaccharide-induced nitric oxide release from rat aorta in vitro.

Ciornei CD, Egesten A, Bodelsson M.

Department of Anaesthesiology and Intensive Care, Lund University, Lund, Sweden.

BACKGROUND: Lipopolysaccharides (LPS), released by Gram-negative bacteria, cause

vascular expression of inducible nitric oxide synthase (iNOS) leading to nitric

oxide (NO) production and septic shock. Human cathelicidin antimicrobial peptide

(LL-37) can bind and neutralize LPS. We wanted to study whether LL-37 affects LPS

or interleukin-1beta (IL-1beta)-induced production, release and function of NO in

intact rat aorta rings and cultured rat aorta smooth muscle cells. METHODS:

Isolated segments of thoracic aorta and cultured cells were incubated in the

presence of LPS, LL-37, LPS + IL-37, IL-1beta, IL-1beta + IL-37 or in medium

alone. Smooth muscle contraction in response to phenylephrine and accumulation of

the sdegradation products of NO, nitrate and nitrite, were measured on aorta

segments. Levels of iNOS were assessed by Western blot and cytotoxic effects were

detected by measurement of DNA fragmentation in cultured cells. Number of viable

cells were determined after Trypan blue treatment. RESULTS: Both LPS and IL-1beta

reduced contractility in response to phenylephrine and increased NO production as

well as iNOS expression. LL-37 inhibited the LPS depression of vascular

contractility induced only by LPS. LL-37 reduced both the LPS- and

IL-1beta-induced NO production and iNOS expression. LL-37 at high concentrations

induced DNA fragmentation and decreased the number of living cells. CONCLUSION:

IL-37 reduces NO production induced by LPS and IL-1beta. The reduction does not

seem to result only from neutralization of LPS but also from a cytotoxic effect,

possibly via induction of apoptosis. Copyright Acta Anaesthesiologica

Scandinavica 47 (2003)

Infect Immun. 1995 Apr;63(4):1291-7.

Human CAP18: a novel antimicrobial lipopolysaccharide-binding protein.

Larrick JW, Hirata M, Balint RF, Lee J, Zhong J, Wright SC.

Palo Alto Institute of Molecular Medicine, Mountain View, California 94043.

CAP18 (18-kDa cationic antimicrobial protein) is a protein originally identified

and purified from rabbit leukocytes on the basis of its capacity to bind and

inhibit various activities of lipopolysaccharide (LPS). Here we report the

cloning of human CAP18 and characterize the anti-LPS activity of the C-terminal

fragment. Oligonucleotide probes designed from the rabbit CAP18 cDNA were used to

identify human CAP18 from a bone marrow cDNA library. The cDNA encodes a protein

composed of a 30-amino-acid signal peptide, a 103-amino-acid N-terminal domain of

unknown function, and a C-terminal domain of 37 amino acids homologous to the

LPS-binding antimicrobial domain of rabbit CAP18, designated CAP18(104-140). A

human CAP18-specific antiserum was generated by using CAP18 expressed as a fusion

protein with the maltose-binding protein. Western blots (immunoblots) with this

antiserum showed specific expression of human CAP18 in granulocytes. Synthetic

human CAP18(104-140) and a more active truncated fragment, CAP18(104-135), were

shown to (i) bind to erythrocytes coated with diverse strains of LPS, (ii)

inhibit LPS-induced release of nitric oxide from macrophages, (iii) inhibit

LPS-induced generation of tissue factor, and (iv) protect mice from LPS

lethality. CAP18(104-140) may have therapeutic utility for conditions associated

with elevated concentrations of LPS.

Life Sci. 2005 Nov 26;78(2):134-9. Epub 2005 Aug 19.

Inhibitory mechanisms of highly purified vitamin B2 on the productions of proinflammatory cytokine and NO in endotoxin-induced shock in mice.

Kodama K, Suzuki M, Toyosawa T, Araki S.

Tsukuba Research Laboratories, Eisai Co., Ltd., 5-1-3 Tokodai, Tsukuba, Ibaraki

300-2635, Japan. k-kodama@hhc.eisai.co.jp

Inhibitory effects of highly purified vitamin B2 (riboflavin-5'-sodium phosphate,

>97%) on the interleukin (IL)-6, macrophage inflammatory protein (MIP)-2 and

nitric oxide (NO) in LPS-induced shock mice were evaluated. Vitamin B2 at 20

mg/kg (protective effect on mice mortality induced by LPS), intravenously

administered 6 h after LPS injection, significantly decreased the plasma elevated

levels of IL-6 and MIP-2 at 9 and 12 h. In addition, vitamin B2 lowered the

tissue concentration and the mRNA expression of IL-6 in lung and those of MIP-2

in liver at 9 h. Vitamin B2 also reduced concentration of MIP-2 concentration in

lung, and inhibited mRNA expression in kidney, respectively. Vitamin B2 decreased

the plasma elevated NO levels in accordance with a reduction in expression of

inducible NO synthase (iNOS) both at 21 and 24 h. Accordingly, the reduction in

elevated plasma cytokine levels and NO based on the inhibitory effect on local

cytokine mRNA expression and iNOS would be responsible for the anti-septic effect

of vitamin B2.

Eur J Pharmacol. 2004 May 25;492(2-3):273-80.

Effects of intravenous infusion of highly purified vitamin B2 on lipopolysaccharide-induced shock and bacterial infection in mice.

Toyosawa T, Suzuki M, Kodama K, Araki S.

Tsukuba Research Laboratories, Eisai Co., Ltd., 5-1-3 Tokodai, Tsukuba, Ibaraki

300-2635, Japan.

We investigated the effect of an i.v. infusion of highly purified vitamin B(2)

(riboflavin 5'-sodium phosphate: purity >97%) on lipopolysaccharide-induced shock

and bacterial infection in mice. Six hours after lipopolysaccharide injection or

1 h after bacterial infection, vitamin B(2) or human activated protein C (APC)

was administered by 6-h i.v. infusion. Vitamin B(2) at 10 mg/kg/6 h and up to 80

mg/kg/6 h significantly improved lipopolysaccharide-induced endotoxin shock. APC

was also effective at low doses, but was deleterious at higher doses. Moreover,

vitamin B(2) at 80 mg/kg/6 h significantly reduced the lethality of Escherichia

coli and Staphylococcus aureus infection, whereas APC at up to 600 units/kg/6 h

was ineffective. The i.v. infusion of vitamin B(2) reduced the elevations of

proinflammatory cytokines and nitric oxide induced by lipopolysaccharide. These

results suggest that i.v. infusion of vitamin B(2) represents a promising

strategy for the treatment of sepsis and septic shock.

Eur J Pharmacol. 2004 May 10;492(1):35-40.

Riboflavin reduces hyperalgesia and inflammation but not tactile allodynia in the rat.

Granados-Soto V, Ter·n-Rosales F, Rocha-Gonz·lez HI, Reyes-GarcÌa G,

Medina-Santill·n R, RodrÌguez-Silverio J, Flores-Murrieta FJ.

Departamento de FarmacobiologÌa, Centro de InvestigaciÛn y de Estudios Avanzados

del Instituto PolitÈcnico Nacional, Calzada Tenorios 235, Colonia Granjas Coapa,

14330 MÈxico, DF, Mexico. vgranados@prodigy.net.mx

Vitamin B2 (riboflavin) has been proposed as a prophylactic therapy of migraine.

However, so far there are no preclinical studies about the analgesic properties

of this vitamin. The current study was designed to investigate the possible

antinociceptive, antihyperalgesic and antiallodynic effect of riboflavin in

formalin, carrageenan-induced thermal hyperalgesia, and spinal nerve ligation

models, respectively. Oral riboflavin produced a dose-related antinociceptive

(6.25-50 mg/kg), antihyperalgesic (25-150 mg/kg) and anti-inflammatory (50-150

mg/kg) effect. Gabapentin (100 mg/kg, positive control), but not riboflavin

(150-600 mg/kg), reduced tactile allodynia in neuropathic rats.

Riboflavin-induced antinociception in the formalin test was reversed by

pretreatment with NG-L-nitro-arginine methyl ester and glibenclamide, but not by

NG-D-nitro-arginine methyl ester or naloxone. Our results indicate that

riboflavin is able to produce antinociception and anti-inflammatory, but not

antiallodynic, effect in the rat. The effect of riboflavin could be due to the

activation of K+ channels or nitric oxide release, but not activation of opioid


J Biol Chem. 2000 Oct 13;275(41):31581-7.

Nitric-oxide dioxygenase activity and function of flavohemoglobins. sensitivity to nitric oxide and carbon monoxide inhibition.

Gardner PR, Gardner AM, Martin LA, Dou Y, Li T, Olson JS, Zhu H, Riggs AF.

Division of Critical Care Medicine, Children's Hospital Medical Center,

Cincinnati, Ohio 45229, USA.


From: Steve Johnson, M.D. [Note: Dr. J serves on the RRDi Board of Directors]

Subject: Re: your thoughts?

Date: August 10, 2007 12:59:30 AM HST

To: director@irosacea.org

Even if we can call this a "cause" and the article seems to point that out, it may be years befor we discover how to treat rosacea especially at this level. We might know what causes the common cold, but still must suffer with all of the symptoms. Thanks, Brady...DrJ


From: Robert Brodell, M.D.

Date: August 10, 2007 12:47:06 PM HST

To: director@irosacea.org

Understanding the mediators of psoriasis revolutionized the treatment of this disease with the advent of biologic drugs. An increased understanding of mediators in rosacea is ultimately going to lead to the same kind of progress.

Bob Brodell


From: Marianne Boes, Ph.D.

Subject: Re: Question for the MAC Members

Date: August 18, 2007 12:13:46 PM HST

To: director@irosacea.org

The research described suggests a previously unknown biochemical abnormality in the skin of individuals with rosacea, with offers new targets for intervention and therefore treatment. It is too simple to state that exacerbated innate immune responses cause rosacea, but that they are involved is clear. What would be the reason for increased SCTE activity? This new research has opened a venue for further investigation that may eventtually lead to a cure.



Link to comment
Share on other sites

  • MAC Member

It would be nice to know if there is an abundance of Cathelicidin

in an ocular rosacea patient's tear film as well. Most of our literature

points to facial issues but I personally have never seen a

facial rosacea patient that does not have ocular involvement

as well despite previous reports. Although nice this is probably

only a small step in the right direction.

Link to comment
Share on other sites

  • 2 weeks later...
  • MAC Member

This is an important study that adds to our understanding of one of the causal components of rosacea. The scientific and media attention will hopefully drive more research that can help fill in the gaps. New ideas and data about components of the innate immune system are by no means a magic bullet-type answer to either the cause or treatment, but this work, with other research in skin barrier, immunology and microbiology, will bring us closer to the "truth."

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...

Important Information

Terms of Use