ABSTRACT
Psoriasis is an immune cell-dependent chronic autoimmune skin disorder. Interleukin 37 (IL-37) is a cytokine belonging to the IL-1 family that shows anti-inflammatory and protective effects in various mouse models of psoriasis. Even though various animal models are used to investigate the pathogenic mechanisms of psoriasis, human clinical studies are still needed to make up for the deficiencies, as animal models generally do not exhibit the complex phenotypic features of human psoriasis. Our study aims to demonstrate the relationship between IL-37-producing tissue-resident immune cells with the pathogenesis of psoriasis. The present study was performed on 28 psoriasis patients and 17 healthy volunteers. The ability of anti-inflammatory cytokine IL-37 to impede inflammation and regulate metabolic pathways was assessed by real-time quantitative polymerase chain reaction. Finally, immunofluorescence double staining for CD4+ IL-37b+ , CD68+ IL-37b+ , and (forkhead box protein P3) Foxp3+ IL-37b+ was performed. The proportion of CD4+ IL-37b+ T cells, CD68+ IL-37b+ macrophages, and Foxp3+ IL-37b+ T regulatory (Treg) cells was significantly increased in the psoriasis group compared to the control group. IL-37 gene expression was downregulated in psoriasis when contrasted to the control group. Our findings disclosed that IL-37-producing tissue-resident immune cells might be involved in the pathogenesis of psoriasis, and thus may be a therapeutic target for individuals with psoriasis.
ABSTRACT
PURPOSE: The present study aims to investigate the radioprotective effect of melatonin (MEL) against early period brain damage caused by different dose rate beams in the experimental rat model. MATERIALS AND METHODS: Forty-eight Sprague Dawley rats were randomly divided into six groups; the control, only melatonin, low dose rate-radiotherapy (LDR-RT), high dose rate-radiotherapy (HDR-RT) groups and (LDR-RT) + MEL and (HDR-RT) + MEL radiotherapy plus melatonin groups. Each rat administered melatonin was given a dose of 10 mg/kg through intraperitoneal injection, 15 minutes before radiation exposure. The head and neck region of each rat in only radiotherapy and radiotherapy plus melatonin groups was irradiated with a single dose of 16 Gy in LDR-RT and HDR-RT beams. Rats in all groups were examined for histopathology and biochemistry analysis 10 days after radiotherapy. RESULTS: Comparing the findings for LDR-RT and HDR-RT only radiotherapy groups and the control group, there was a statistically significant difference in histopathological and biochemical parameters, however, melatonin administered in radiotherapy plus melatonin groups contributed improving these parameters (p < .05). There was no statistically significant difference between LDR-RT and HDR-RT beams (p > .05). CONCLUSIONS: It was concluded that melatonin applied before LDR-RT and HDR-RT radiotherapy protected early period radiotherapy-induced brain damage. The effects of clinically low and high dose beams on the cerebral cortex and cerebellum were investigated histopathologically for the first time. HDR beams can be safely applied in brain radiotherapy. However, more experimental rat and clinical studies are needed to explain the radiobiological uncertainties about the clinic dose rate on different cancerous and healthy tissues.
