Transcription factor 7-like 1 dysregulates keratinocyte differentiation through upregulating lipocalin 2

Targeted siRNA Therapy for Psoriasis: Translating Preclinical Potential into Clinical Treatments

Psoriasis is a chronic inflammatory skin disease characterized by the excessive proliferation of keratinocytes and heightened immune activation. Targeting pathogenic genes through small interfering RNA (siRNA) therapy represents a promising strategy for the treatment of psoriasis. This mini-review provides a comprehensive summary of siRNA research targeting the pathogenesis of psoriasis, covering aspects such as keratinocyte function, inflammatory cell roles, preclinical animal studies, and siRNA delivery mechanisms. It details recent advancements in RNA interference that modulate key factors including keratinocyte proliferation (Fibroblast Growth Factor Receptor 2, FGFR2), apoptosis (Interferon Alpha Inducible Protein 6, G1P3), differentiation (Grainyhead Like Transcription Factor 2, GRHL2), and angiogenesis (Vascular Endothelial Growth Factor, VEGF); immune cell infiltration and inflammation (Tumor Necrosis Factor-Alpha, TNF-α; Interleukin-17, IL-17); and signaling pathways (JAK-STAT, Nuclear Factor Kappa B, NF-κB) that govern immunopathology. Despite significant advances in siRNA-targeted treatments for psoriasis, several challenges persist. Continued scientific developments promise the creation of more effective and safer siRNA medications, potentially enhancing the quality of life for psoriasis patients and revolutionizing treatments for other diseases. This article focuses on the most recent research advancements in targeting the pathogenesis of psoriasis with siRNA and explores its future therapeutic prospects.

Serum and Tissue Lipocalin-2 Expression in Chronic Kidney Disease Pruritic Patients

BACKGROUND

Uremic pruritus is an irritating symptom for patients with end-stage kidney disease. Lipocalin-2 (LCN2) has relevant importance in several biological cellular processes and immunity. It is also a major player in the progression of many disorders, such as renal injury.

AIM

To evaluate LCN2 expression in chronic kidney disease (CKD) pruritic patients in serum together with immunohistochemical expression in skin samples and further correlation of their results with the studied clinicopathologic parameters.

MATERIALS AND METHODS

Serum level of LCN2 (assessed by enzyme-linked immunosorbent assay) and skin immunohistochemical expression were investigated in 25 CKD patients and 25 healthy controls. Ten patients were subjected to narrowband ultraviolet B phototherapy for 12 weeks then re-evaluated for serum and tissue LCN2 after therapy.

RESULTS

LCN2 expression was increased significantly in both the epidermis and dermal adnexa in CKD patients over controls. Also, serum LCN2 level was higher in patients than in healthy subjects and was significantly associated with itching severity, grades of CKD, urea, and creatinine serum level. Tissue and serum levels of LCN2 were significantly diminished in CKD patients following narrowband therapy along with improvement of the severity of pruritus.

CONCLUSIONS

The increased serum and tissue LCN2 expression in CKD pruritic patients and its pronounced decrease, in addition to the improvement of pruritus after treatment, suggest a major pathogenic role of LCN2 in uremic pruritus.

TCF7L1 Accelerates Smooth Muscle Cell Phenotypic Switching and Aggravates Abdominal Aortic Aneurysms

Phenotypic switching of vascular smooth muscle cells is a central process in abdominal aortic aneurysm (AAA) pathology. We found that knockdown TCF7L1 (transcription factor 7-like 1), a member of the TCF/LEF (T cell factor/lymphoid enhancer factor) family of transcription factors, inhibits vascular smooth muscle cell differentiation. This study hints at potential interventions to maintain a normal, differentiated smooth muscle cell state, thereby eliminating the pathogenesis of AAA. In addition, our study provides insights into the potential use of TCF7L1 as a biomarker for AAA.

Neutrophil Gelatinase-Associated Lipocalin as Potential Predictive Biomarker of Melanoma and Non-Melanoma Skin Cancers in Psoriatic Patients: A Pilot Study

Background: Studies have demonstrated a higher risk of nonmelanoma skin cancers (NMSC) and a modestly increased melanoma risk in patients with psoriasis. To date, no biomarkers predictive of evolution have been identified yet. Methods: The aim of this prospective case-control study was to investigate the potential role of neutrophil gelatinase-associated lipocalin (NGAL) as a predictive biomarker of skin cancers in psoriatic patients. Patients with a diagnosis of psoriasis were enrolled, as well as healthy subjects and patients with skin cancers as controls. Plasma protein expression of NGAL, metalloproteinases (MMP)-2, and MMP-9 was performed by an enzyme-linked immunosorbent assay (ELISA). In all the patients who developed skin cancer at follow-up, NGAL, MMP-2, and MMP-9 serum levels were dosed again. Results: Plasma NGAL levels were significantly higher in psoriatic patients with NMSC than without (182.3 ± 36.6 ng/mL vs. 139.9 ± 39.3 ng/mL) (p < 0.001). Plasma NGAL levels were significantly higher (p < 0.00001) in patients with psoriasis and NMSC than in patients with skin tumors without psoriasis (182.3 vs. 122.9). Patients with psoriasis who developed NMSC at follow-up showed increased plasma MMP-9 levels. Conclusion: NGAL seems to play a role in the pathogenesis of NMSC but not melanoma in patients with psoriasis.

Lipocalin 2 Participates in the Epidermal Differentiation and Inflammatory Processes of Psoriasis

As a multifunctional cytokine, lipocalin 2 is weakly expressed in skin and serum under normal conditions. However, it is over-expressed by neutrophils and keratinocytes in the skin lesions and sera in several skin diseases. Recent studies demonstrated that lipocalin 2 participates in the pathogenesis of psoriasis by exerting versatile effects on skin resident cells and infiltrating immune cells. Lipocalin 2 inhibits the synthesis of keratin, involucrin, and loricrin in keratinocytes, leading to epidermal parakeratosis via the Tcf7l1-lipocalin 2 signaling axis. It also recruits inflammatory cells such as T cells and neutrophils into skin lesions via the IL-23/IL17, p38-MAPK, and ERK-1/2 signaling pathways. Additionally, lipocalin 2 and other cytokines such as IL-17 have the synergetic effects on skin cells. The neutralization of lipocalin 2 or relevant cytokines can alleviate psoriasis, verifying that lipocalin 2 is an effective interfering target for psoriasis. In this review, we summarize the roles of lipocalin 2 in the processes of psoriatic inflammation and the promising therapeutic strategies based on lipocalin 2-related molecules.

Adipokines in the Skin and in Dermatological Diseases

Adipokines are the primary mediators of adipose tissue-induced and regulated systemic inflammatory diseases; however, recent findings revealed that serum levels of various adipokines correlate also with the onset and the severity of dermatological diseases. Importantly, further data confirmed that the skin serves not only as a target for adipokine signaling, but may serve as a source too. In this review, we aim to provide a complex overview on how adipokines may integrate into the (patho) physiological conditions of the skin by introducing the cell types, such as keratinocytes, fibroblasts, and sebocytes, which are known to produce adipokines as well as the signals that target them. Moreover, we discuss data from in vivo and in vitro murine and human studies as well as genetic data on how adipokines may contribute to various aspects of the homeostasis of the skin, e.g., melanogenesis, hair growth, or wound healing, just as to the pathogenesis of dermatological diseases such as psoriasis, atopic dermatitis, acne, rosacea, and melanoma.

Lipocalin 2: An Emerging Player in Iron Homeostasis and Inflammation

Lipocalin 2 (Lcn2), an innate immune protein, has emerged as a critical iron regulatory protein during physiological and inflammatory conditions. As a bacteriostatic factor, Lcn2 obstructs the siderophore iron-acquiring strategy of bacteria and thus inhibits bacterial growth. As part of host nutritional immunity, Lcn2 facilitates systemic, cellular, and mucosal hypoferremia during inflammation, in addition to stabilizing the siderophore-bound labile iron pool. In this review, we summarize recent advances in understanding the interaction between Lcn2 and iron, and its effects in various inflammatory diseases. Lcn2 exerts mostly a protective role in infectious and inflammatory bowel diseases, whereas both beneficial and detrimental functions have been documented in neurodegenerative diseases, metabolic syndrome, renal disorders, skin disorders, and cancer. Further animal and clinical studies are necessary to unveil the multifaceted roles of Lcn2 in iron dysregulation during inflammation and to explore its therapeutic potential for treating inflammatory diseases.

The acitretin and methotrexate combination therapy for psoriasis vulgaris achieves higher effectiveness and less liver fibrosis

Both acitretin and methotrexate are effective in ameliorating psoriatic lesion. However, their combination has been seldom reported in the treatment of psoriasis because of the warning regarding the potential hepatotoxicity of the drug interactions. This study was designed to investigate the effectiveness of such combination therapy for psoriasis vulgaris, and the potential benefit as well as side effect during the treatment. Thirty-nine patients with psoriasis vulgaris were treated with acitretin, methotrexate or their combination or as control. Similarly, K14-VEGF transgenic psoriasis-like mice were treated with these drugs. Human primary keratinocytes and hepatic stellate cells were used for analyzing their effect in vitro. The results showed that the combination therapy exhibited higher effectiveness in remitting skin lesion, but did not significantly affect the liver function of both patients and mice. Moreover, the combination groups showed less elevation of profibrotic factors in sera when compared with methotrexate alone groups accordingly. Furthermore, primary keratinocytes expressed more involucrin as well as loricrin and proliferated more slowly on the combined stimulation. Interestingly, such combination treatment induced lower expression of profibrotic factors in hepatic stellate cells. In conclusion, the acitretin-methotrexate combination therapy for psoriasis vulgaris can achieve higher effectiveness and result in less liver fibrosis.