Granulysin expression increases with increasing clinical severity of psoriasis

The role of GNLY gene polymorphisms in psoriasis pathogenesis

BACKGROUND

Psoriasis is a systemic inflammatory disorder that involves complex pathogenic interactions between the innate and adaptive immune systems. The most accepted mechanism in the etiopathogenesis of psoriasis is the induction of inflammation with keratinocyte hyperproliferation. Granulysin (GNLY) is a cytolytic antimicrobial peptide (AMP) that is secreted together with granzyme and perforin from the granules of human cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells. It has been immunohistochemically proven that the expression of granulysin is increased in lesions of psoriasis.

OBJECTIVE

This study aimed to investigate the relationship between psoriasis disease and granulysin gene polymorphisms.

METHODS

GNLY rs7908 and rs10180391 polymorphisms were studied by PCR-RFLP in 100 psoriasis patients under treatment in the Dermatology Polyclinic of Bulent Ecevit University. In addition, 100 healthy individuals with similar age and sex distribution were used as a control group.

RESULTS

In the control group, GNLY rs7908 CC genotype was significantly higher than in psoriasis patients (P= 0.031; OR= 0.305; Cl= 0.305 (0.121 - 0.773). In our study, the genotype distributions in patients and control groups were GNLY rs7908 (SNP) GG (51%, 37%), GC (41%, 44%), CC (8%, 19%); GNLY rs10180391 (SNP) from the CC (41%, 44%), CT (42%, % 41), TT (17%, 15%).

STUDY LIMITATIONS

The study only included Turkish patients.

CONCLUSION

Our findings showed that GNLY rs7908 CC genotype and C allele had a protective effect against psoriasis and decreased the disease severity (according to PASI score), whereas rs10180391 SNP did not show any effective role in psoriasis pathogenesis.

Antimicrobial peptides and wound healing: biological and therapeutic considerations

Repair of tissue wounds is a fundamental process to re-establish tissue integrity and regular function. Importantly, infection is a major factor that hinders wound healing. Multicellular organisms have evolved an arsenal of host-defense molecules, including antimicrobial peptides (AMPs), aimed at controlling microbial proliferation and at modulating the host's immune response to a variety of biological or physical insults. In this brief review, we provide the evidence for a role of AMPs as endogenous mediators of wound healing and their promising therapeutic potential for the treatment of non-life-threatening skin and other epithelial injuries.

Cytotoxic T lymphocytes as a potential brake of keratinocyte proliferation in psoriasis

Psoriasis is a chronic papulosquamous skin disease, histologically characterized by epidermal hyperproliferation and dermal infiltration of inflammatory cells. The majority of T lymphocytes infiltrating dermis are CD4+ T lymphocytes secreting type 1 and type 17 cytokines. These cytokines are responsible for triggering keratinocyte proliferation as well as chemokine secretion and subsequent migration of other inflammatory cells in the skin. Contrarily, lymphocytes that accumulate in epidermis are mainly CD8+ T lymphocytes. According to the recent findings, these cells can also secrete type 1 and type 17 cytokines. However, it is demonstrated so far that epidermal CD8+ T lymphocytes contain higher amounts of cytolytic molecules, such as perforin, granzyme B and granulysin whose role in psoriasis pathogenesis is still unknown. Therefore, in this article we hypothesize the active involvement of cell mediated cytotoxicity in killing the proliferating keratinocytes as a mechanism of potential self-defense and possible brake in psoriatic plaque formation, maintaining skin homeostasis.