Apelin12 in Acne Vulgaris

Acne lesions may vary in number during the natural course of the disease and multiple measurements have been developed which is based on clinical examination and photographic documentation, to measure the clinical severity.

The Grading of acne based on the type of lesions, affected surface area and their severity that can help in deciding which therapies are needed in each individual. However, no grading system has been accepted universally. The Global Acne Grading System is a quantitative scoring system to assess the severity of acne. According to this score acne was graded as mild, moderate, severe and very severe.

The severity of acne was also graded using the Comprehensive Acne Severity Scale.

Adipokines are proteins that are synthesized and secreted primarily by adipocytes in response to various stimuli, include interleukin 6 and other small molecular weight bioactive proteins such as adiponectin, resistin, leptin, serpin E1 [also known as plasminogen activator inhibitor 1 and endothelial plasminogen activator inhibitor], visfatin (also known as nicotinamide phosphoribosyltransferase), apelin, chemerin, retinol binding protein 4, and monocyte chemoattractant protein 1.

Due to their different biological properties and diverse cellular targets adipokines are involved in a wide array of (patho)physiological processes and are responsible for mediating the inflammatory effects of the adipose tissue in the local tissue environment as well as to different organs via circulation. By detecting alterations in their serum levels also in dermatological diseases such as acne vulgaris and psoriasis, extensive studies have also started in dermatological research to identify the possible targets and the cutaneous sources of these proteins.

Apelin is an endogenous ligand of the previously discovered "orphan" receptor named APJ, isolated from bovine stomach extracts.

It is a product of apelin gene that is located on chromosome Xq25-26.1 and translated as a 77 amino acid prepropeptide. It is processed into several active molecular forms with different biological activities. Apelin belongs to adipokines group because its m-RNA expression has been demonstrated in mature adipocytes in rodents and humans.

Apelin peptide expression has been also demonstrated in several tissues and seems to have different regulatory functions, depending on the expressing tissue, the apelinergic system distribution over such a variety of tissues has suggested that it might play relevant roles in human physiology.

Apelin has been reported to have an effect on appetite, drinking behavior, angiogenesis, and the cardiovascular system. It is regulated by insulin. Apelin might be a novel target for preventing obesity and obesity-related diseases via enhancement of vascular integrity.

Several active apelin forms exist such as apelin-36, apelin-17, apelin-13, and apelin-12.

Apelin-12 is a 12-amino peptide fragment that has been implicated in reducing blood pressure via a nitric oxide mechanism, and is involved in feeding mechanisms via stimulation of cholecystokinin secretion.

It is considered to be one of the most potent isoform of apelin.

The studies evaluating the role of adipokines are very few in patient with acne vulgaris.