Expression of cold-inducible RNA binding protein in psoriasis

Seasonal fluctuation of serum Krebs von den Lungen-6 levels in systemic sclerosis-associated interstitial lung disease

AIM

To evaluate whether seasonal changes influence fluctuations in serum Krebs von den Lungen-6 (KL-6) levels in systemic sclerosis-related interstitial lung disease (SSc-ILD).

METHODS

Summer was defined as the period between July and September, and winter as between December and February. The study was conducted between 2015 and 2016, with a focus on these two seasons. A diagnosis of ILD and ILD progression overtime were evaluated using chest computed tomography. Among patients with SSc-ILD, those with data on serum KL-6 and lactate dehydrogenase (LDH) levels in the 2015 winter, 2015 summer, and 2016 winter seasons were included. Patients with comorbidities that could affect serum KL-6 levels were excluded.

RESULTS

Of 60 patients with SSc-ILD, 52 (86.7%) had stable ILD, 5 (8.3%) had worsened ILD, and 3 (5.0%) had improved ILD. Serum KL-6 levels were significantly higher during the winter than those during the summer (2015 winter vs. 2015 summer: 649 U/mL vs. 585 U/mL, p < .0001; 2016 winter vs. 2015 summer: 690 U/mL vs. 585 U/mL, p < .0001). No significant differences were observed between the winters of 2015 and 2016 (649 U/mL vs. 690 U/mL, p = .78). However, serum LDH levels did not exhibit seasonal fluctuations (2015 winter vs. 2015 summer: 203 U/L vs. 199 U/L, p = .3; 2016 winter vs. 2015 summer: 201 U/L vs. 199 U/L, p = .6; 2015 winter vs. 2016 winter: 203 U/L vs. 201 U/L, p = .24).

CONCLUSION

Seasonal fluctuations in serum KL-6 levels were observed in patients with SSc-ILD.

Evaluation of serum and tissue levels of cold-inducible RNA-binding protein in non-segmental Vitiligo

Damage-associated molecular patterns (DAMPs) play a role in the pathogenesis of vitiligo. It has been established that the cold-inducible RNA-binding protein (CIRP), a member of the family of cold-shock proteins that respond to stress, is a DAMP molecule that promotes inflammation. The objective was to evaluate the serum and tissue CIRP expression in non-segmental vitiligo (NSV) patients. A sample of 40 participants, 20 NSV patients and 20 control groups of age- and sex-matched healthy individuals were included in this case-control study where the enzyme-linked immunosorbent assay was used in detecting the serum and tissue CIRP levels in participants. The serum and tissue CIRP levels significantly increased in NSV patients compared with the healthy controls, (165.35 ± 24.42, 226.29 ± 24.00 versus 59.81 ± 12.10, 105.86 ± 11.27 pg/ml, respectively) (P < 0.01). Serum and tissue CIRP are significantly correlated with each other (r = 0.641, P = 0.002). Except for a statistically significant positive correlation between CIRP tissue level and VASI (r = 0.539, P = 0.014), the CIRP Serum and tissue did not show any statistically significant correlations with different clinical parameters in patients. ROC curve shows that the cut-off point for serum and tissue CIRP level to differentiate between patients and controls was 86.5, 124.3 pg/ml, respectively, with 100.0% sensitivity, 100.0% specificity and 1.000 AUC for each of them. It is concluded that CIRP may have a crucial role in the pathogenesis of NSV and could be used as a marker for vitiligo and its extent with the need for further large-scale study.

Serum cold-inducible RNA-binding protein levels as a potential biomarker for systemic sclerosis-associated interstitial lung disease

Systemic sclerosis (SSc) is a complex autoimmune disease characterized by fibrotic, inflammatory, and vascular dysfunction. Danger-associated molecular patterns (DAMPs)-mediated inflammasome activation has been reported to be involved in the pathogenesis of SSc. Cold-inducible RNA-binding protein (CIRP) is newly identified as a DAMP. Here we examined the clinical significance of serum levels of CIRP in 60 patients with SSc and 20 healthy control patients (HCs) using an enzyme-linked immunosorbent assay. Serum CIRP levels in diffuse cutaneous SSc (dcSSc) patients were significantly increased compared with limited cutaneous SSc (lcSSc) patients or HCs. When examining the relationship with SSc-specific parameters, serum CIRP levels with the presence of interstitial lung disease (ILD) were higher than those without ILD. In detail, serum CIRP levels correlated negatively with the percent predicted diffusing capacity for carbon monoxide and positively with levels of Krebs von den Lungen-6. In addition, elevated serum CIRP levels declined along with decreased SSc-ILD activity in patients who received immunosuppressive therapy. These results suggest that CIRP may play a role in the development of ILD in SSc. Moreover, CIRP could serve as a useful serological marker of SSc-ILD in terms of disease activity and therapeutic effects.

Extracellular CIRP Upregulates Proinflammatory Cytokine Expression via the NF-kappaB and ERK1/2 Signaling Pathways in Psoriatic Keratinocytes

Psoriasis is a chronic inflammatory skin disease, and elevation of proinflammatory cytokine levels is a critical driver of the pathogenesis of psoriasis. Extracellular cold-inducible RNA-binding protein (eCIRP) has been shown to play a role in various acute and chronic inflammatory diseases. C23, a short peptide derived from CIRP, competitively binds CIRP receptors and reduces damage in inflammatory diseases. However, the effect of eCIRP in psoriasis has not been studied. In the present study, we investigated the role of eCIRP in the expression of proinflammatory cytokines in keratinocytes. Our data show that eCIRP expression was increased in the sera of psoriasis patients and imiquimod- (IMQ-) induced psoriatic mice and cells stimulated with proinflammatory cytokines (IL-1α, IL-17A, IL-22, oncostatin M, and TNF-α; mix M5). Recombinant human CIRP (rhCIRP) promoted the expression of the proinflammatory cytokines TNF-α, IL-6, and IL-8 and the activation of NF-kappaB (NF-κB) and ERK1/2 in cultured keratinocytes. We then found that the above effects of eCIRP could be blocked by C23 in both normal keratinocytes and M5-stimulated psoriatic keratinocytes. In addition, in vivo experiments revealed that C23 could effectively ameliorate IMQ-induced psoriatic dermatitis. TNF-α and IL-6 mRNA expressions were reduced in the skin lesions of mice with C23-treated IMQ-induced psoriasis, and this effect was accompanied by inhibition of the NF-κB and ERK1/2 signaling pathways. In summary, eCIRP plays an important role in the pathogenesis of psoriasis and may become a new target for psoriasis treatment.