TNF-alpha inhibitors and ustekinumab for the treatment of psoriasis: therapeutic utility in the era of IL-17 and IL-23 inhibitors

CXCL12+ dermal fibroblasts promote neutrophil recruitment and host defense by recognition of IL-17

The skin provides an essential barrier for host defense through rapid action of multiple resident and recruited cell types, but the complex communication network governing these processes is incompletely understood. To define these cell-cell interactions more clearly, we performed an unbiased network analysis of mouse skin during invasive S. aureus infection and revealed a dominant role for CXCL12+ fibroblast subsets in neutrophil communication. These subsets predominantly reside in the reticular dermis, express adipocyte lineage markers, detect IL-17 and TNFα, and promote robust neutrophil recruitment through NFKBIZ-dependent release of CXCR2 ligands and CXCL12. Targeted deletion of Il17ra in mouse fibroblasts resulted in greatly reduced neutrophil recruitment and increased infection by S. aureus. Analogous human CXCL12+ fibroblast subsets abundantly express neutrophil chemotactic factors in psoriatic skin that are subsequently decreased upon therapeutic targeting of IL-17. These findings show that CXCL12+ dermal immune acting fibroblast subsets play a critical role in cutaneous neutrophil recruitment and host defense.

Non-Invasive Assessment of Skin Surface Proteins of Psoriasis Vulgaris Patients in Response to Biological Therapy

Measurements of skin surface biomarkers have enormous value for the detailed assessment of skin conditions, both for clinical application and in skin care. The main goals of the current study were to assess whether expression patterns of skin surface hBD-1, hBD-2, IL-1α, CXCL-1, and CXCL-8, examples of proteins known to be involved in psoriasis pathology, are associated with disease severity and whether expression patterns of these proteins on the skin surface can be used to measure pharmacodynamic effects of biological therapy. In this observational study using transdermal analysis patch (TAP), levels of skin surface IL-1α, hBD-1, hBD-2, CXCL-1/2, and CXCL-8 of psoriasis vulgaris (PV) patients over biological therapy were assessed. The Psoriasis Area Severity Index (PASI) and local score for erythema, induration, and desquamation were determined from the exact same skin area as FibroTx TAP measurements. Thirty-seven adult PV patients were included, of which twenty-three were subjected to anti-TNF-α, seven to anti-IL-17A, and seven to anti-IL12/IL-23 therapy. Significantly higher levels of hBD-1, hBD-2, CXCL-1/2, and CXCL-8 were detected on lesional skin compared to the non-lesional skin of the PV patients. In contrast, lower levels of IL-1α were found in lesional skin compared to non-lesional skin. In addition, we observed that the biomarker expression levels correlate with disease severity. Further, we confirmed that changes in the expression levels of skin surface biomarkers during biological therapy correlate with treatment response. Biomarker expression patterns in response to treatment differed somewhat between treatment subtypes. We observed that, in the case of anti-TNF-α therapy, an increase after a steady decrease in the expression levels of CXCL-1/2 and CXCL-8 occurred before the change in clinical scores. Moreover, response kinetics of skin surface proteins differs between the applied therapies-hBD2 expression responds quickly to anti-IL-17A therapy, CXCL-1/2 to anti-IL-12/23, and levels of CXCL-8 are rapidly down-regulated by IL-17A and IL-12/23 therapy. Our findings confirm that the skin surface hBD-2, IL-1α, CXCL-1/2, and CXCL-8 are markers for the psoriasis severity. Further, data obtained during this study give the basis for the conclusion that skin surface proteins CXCL-1/2 and CXCL-8 may have value as therapeutic biomarkers, thus confirming that measuring the 'molecular root' of inflammation appears to have value in scoring disease severity on its own.

Benefits of topical indigo naturalis nanofibrous patch on psoriatic skin: A transdermal strategy for botanicals

Indigo naturalis (IN) has been extensively used as a topical treatment for psoriasis. However, clinical applications of IN in ointment were hampered by its limited transdermal efficiency and dark stains. To address the aforementioned issues, nanopatches carrying IN were fabricated using poly(ε-caprolactone, PCL)/poly(ethylene oxide, PEO) and topically applied to psoriasiform skin. The ideal ratio of 5% PCL/PEO was established to be 80:20 (w/w), and 15% IN as payload was confirmed. Investigations on the three principal active components of IN release indicated that indirubin and tryptanthrin were released in bursts, while indigo was released in a limited and controlled manner. Further biological analyses confirmed a favorable biocompatibility of amphiphilic IN-PCL/PEO, which coincided with the intended therapeutic outcomes as measured by severity index scoring and pathological evaluations in vivo. The advantages of IN as nanopatches over ointment could be due to improved transdermal distribution of indirubin and tryptanthrin, resulting in effective management of epidermal hyperplasia and blood vessel remodeling. Meanwhile, due to the lower preservation of epidermal indigo, IN-PCL/PEO nanopatches caused no skin coloration. Similarly, during a 4-week topical treatment of IN-PCL/PEO nanopatches, the safety and anti-psoriatic benefits were obtained in an initial human test. The conversion of IN from topical cream to electrospun nanofibers opens up new avenues for bench-to-bedside translation of this herbal therapy and provides mechanistic insight into IN's roles in the management of psoriasis.

β-Hydroxy-β-Methylbutyric Acid Promotes Repair of Sheep Myoblast Injury by Inhibiting IL-17/NF-κB Signaling

Delayed muscle development and impaired tissue repair are common occurrences in sheep reared for mutton. Therefore, understanding the regulatory mechanisms involved in muscle growth and development is critical for animal production. Skeletal muscle satellite cells (SMSCs) can simulate the proliferation and differentiation of muscle cells and could be induced to differentiate into myoblasts. β-hydroxy-β-methylbutyric acid (HMB) is an additive commonly used in animal production. This study examined the effect of HMB on myoblast injury repair using flow cytometry, EdU assay, RNA sequencing, Western blot, and ELISA. Our results showed that HMB could inhibit IL-17 expression and, in turn, inhibit NF-κB signaling. By acting on the downstream genes of NF-κB pathway IL-6, TNF-α and IL-1β, HMB inhibits the apoptosis and promotes the proliferation of myoblasts. The findings of this study provide insight into the mechanism by which HMB mediates myoblast injury repair in sheep.