Inflammatory and Immunomodulatory Effects of Tripterygium wilfordii Multiglycoside in Mouse Models of Psoriasis Keratinocytes.

OBJECTIVE: To determine the role of Tripterygium wilfordii multiglycoside (TGW) in the treatment of psoriatic dermatitis from a cellular immunological perspective. METHODS: Mouse models of psoriatic dermatitis were established by imiquimod (IMQ). Twelve male BALB/c mice were assigned to IMQ or IMQ+TGW groups according to a random number table. Histopathological changes in vivo were assessed by hematoxylin and eosin staining. Ratios of immune cells and cytokines in mice, as well as PAM212 cell proliferation in vitro were assessed by flow cytometry. Pro-inflammatory cytokine expression was determined using reverse transcription quantitative polymerase chain reaction. RESULTS: TGW significantly ameliorated the severity of IMQ-induced psoriasis-like mouse skin lesions and restrained the activation of CD45+ cells, neutrophils and T lymphocytes (all P<0.01). Moreover, TGW significantly attenuated keratinocytes (KCs) proliferation and downregulated the mRNA levels of inflammatory cytokines including interleukin (IL)-17A, IL-23, tumor necrosis factor α, and chemokine (C-X-C motif) ligand 1 (P<0.01 or P<0.05). Furthermore, it reduced the number of γ δ T17 cells in skin lesion of mice and draining lymph nodes (P<0.01). CONCLUSIONS: TGW improved psoriasis-like inflammation by inhibiting KCs proliferation, as well as the associated immune cells and cytokine expression. It inhibited IL-17 secretion from γ δ T cells, which improved the immune-inflammatory microenvironment of psoriasis.

The Impact of Proinflammatory Cytokines and Imiquimod on GLUT1 in HaCaT Keratinocytes - a Potential Anti-Psoriatic Therapeutic Target?

BACKGROUND/AIMS: Glucose metabolism has been proven as an essential process for proliferating keratinocytes, which highlights the importance of glucose transporter-1 (GLUT1) not only in the onset of psoriasis but also in the progression and severity of this inflammation-driven disease. In this study, we attempted to find a connection between proinflammatory cytokines (IL-6, IL-17, IL-23, IL-36, TNF-α), a skin inflammation inducing agent - imiquimod (IMQ) and GLUT1 expression. METHODS: Human keratinocyte HaCaT cell line was incubated with exogenous cytokines: IL-6, IL-17A, IL-23, IL-36, TNF-α at a final concentration of 100 ng/ml, or with 1 µM of IMQ, for 48 h. Following the stimulation, glucose uptake and GLUT1 expression were evaluated. The activity of GLUT1 was measured in the presence of a selective GLUT1 inhibitor, BAY-876. The expression of GLUT1 was examined by immunofluorescence and quantified by qPCR, Western blotting and densitometry. RESULTS: The results from qPCR analysis showed that the administration of exogenous IL-6, IL-17, IL-23 and IL-36 to HaCaT cells resulted in upregulation of GLUT1-encoding SLC2A1 gene, while TNF-α had no significant effect. The same results were confirmed by immunofluorescence analysis, as the fluorescent intensity of GLUT1 was elevated following cytokine and IMQ stimulation. Western blot and densitometry showed that all examined cytokines, as well as IMQ, increased GLUT1 expression. HaCaT cells displayed an improved intracellular 2-deoxy-D-glucose (2-DG) uptake and GLUT1 activity after stimulation by exogenous cytokines and IMQ. The highest uptake of 2-DG was observed after IL-23 stimulation (1.93x) and the lowest after TNF-α stimulation (1.07x). BAY-876 inhibited the 2-DG uptake compared to control. CONCLUSION: Our findings suggest that cytokines and IMQ may play a key role in regulating GLUT1 expression in HaCaT cells. We believe that GLUT1 overexpression could potentially be utilized in the targeted treatment of psoriasis.

Alleviation of imiquimod-induced psoriasis-like symptoms in Rorα-deficient mouse skin.

Retinoic acid receptor-related orphan receptor α (RORα) plays a vital role in various physiological processes, including metabolism, cancer, circadian rhythm, cerebellar development, and inflammation. Although RORα is expressed in the skin, its role in skin physiology remains poorly elucidated. Herein, Rorα was expressed in the basal and suprabasal layers of the epidermis; however, keratinocyte-specific Rorα deletion did not impact normal epidermal formation. Under pathophysiological conditions, Rorα-deficient mice exhibited alleviated psoriasis-like symptoms, including relatively intact epidermal stratification, reduced keratinocyte hyperproliferation, and low-level expression of inflammatory cytokines in keratinocytes. Unexpectedly, the splenic population of Th17 cells was significantly lower in keratinocytespecific RORα deficient mice than in the control. Additionally, Rorα-deficiency reduced imiquimod-induced activation of nuclear factor-κB and STAT3 in keratinocytes. Therefore, we expect that RORα inhibitors act on immune cells and keratinocytes to suppress the onset and progression of psoriasis.as an adjuvant for cancer immunotherapy. [BMB Reports 2023; 56(5): 296-301].

[Effect of fire needling on imiquimod induced psoriasis-like lesion and STAT3 pathway in mice].

OBJECTIVE: To observe the effect of fire needling on psoriasis-like lesion and the signal transducer and activator of transcription 3 (STAT3) pathway in mice and compare the therapeutic effect between different interventions of fire needling therapy (surrounding technique of fire needling, fire needling at "Dazhui" [GV 14] and "Zusanli" [ST 36]). METHODS: Thirty male BALB/c mice were randomized into a blank group, a model group, a dexamthasone group, a surrounding technique group and an acupoint group, 6 mice in each one. Except the blank group, the mice in the rest groups were established as psoriasis-like lesion model by topical application with imiquimod cream, once daily, consecutively for 8 days. From day 4 to day 8, in the dexamthasone group, gastric infusion with 0.2 mL dexamthasone was administered, once daily. On day 4, 6 and 8, in the surrounding technique group, fire needling was exerted around the skin lesion; and fire needling was applied to "Dazhui" (GV 14) and "Zusanli" (ST 36) in the acupoint group, once a day. The changes in skin lesion on the dorsal parts of mice were observed in each group to score the psoriasis area and severity index (PASI). Using HE staining, the dermal morphological changes and epidermal thickness were observed in the mice of each group. The positive expression of proliferating cell-associated antigen Ki-67 was determined by immunofluorescence. Immunohistochemistry method was used to determine the expressions of , and T cells of skin tissue in each group. Using real-time PCR, the expressions of interleukin (IL)-17, IL-22, tumor necrosis factor α(TNF-α) mRNA were determined. Western blot method was adopted to determine the protein expressions of STAT3 and p-STAT3 in skin tissue in each group. RESULTS: Compared with the blank group, the scores of each item and the total scores of PASI, as well as the epidermal thickness were all increased in the mice of the model group (P<0.01). Except for the erythema scores of the dexamethasone group and the surrounding technique group, the scores of each item and the total scores of PASI, as well as the epidermal thickness were all decreased in each intervention group as compared with the model group (P<0.01). The infiltration scores and the total scores in the dexamethasone group and the acupoint group were lower than those in the surrounding technique group respectively (P<0.01, P<0.05). In comparison with the blank group, Ki-67 positive cell numbers and the numbers of , and T cells in skin tissue were increased in the mice of the model group (P<0.01). Ki-67 positive cell numbers and the numbers of , and T cells were reduced in each intervention group as compared with the model group (P<0.01), and the numbers of and T cells in the acupoint group were less than the surrounding technique group (P<0.01). Compared with the blank group, the mRNA expressions of IL-17, IL-22 and TNF-α and the ratio of p-STAT3 to STAT3 were all increased in the model group (P<0.01). The mRNA expressions of IL-17, IL-22 and TNF-α and the ratio of p-STAT3 to STAT3 were all decreased in each intervention group as compared with the model group (P<0.01, P<0.05). The mRNA expressions of IL-17, IL-22 and TNF-α in the acupoint group, as well as mRNA expression of IL-17 in the surrounding technique group were all lower than the dexamethasone group (P<0.01), while, the mRNA expression of IL-22 in the acupoint group was lower than the surrounding technique group (P<0.01). CONCLUSION: Fire needling therapy improves skin lesion severity in imiquimod induced psoriasis-like lesion of the mice, which is probably related to the inhibition of STAT3 pathway activation and the decrease of Th17 inflammatory factors expression. The systemic regulation of fire needling at "Dazhui" (GV 14) and "Zusanli" (ST 36) is superior to the local treatment.

Cytotoxicity of Saikosaponin A targets HEKa cell through apoptosis induction by ROS accumulation and inflammation suppression via NF-κB pathway.

Saikosaponin A (SSA) is a triterpenoid saponin extracted from oriental medicinal plant Radix bupleuri, possessing various biological functions such as anti-inflammatory, immune regulation and anti-virus. This study aimed to explore therapeutic effects of SSA on psoriasis in both vitro and vivo. Our results showed that SSA increased reactive oxygen species (ROS) generation, and decreased mitochondrial membrane potential (MMP) and M5-induced inflammatory cytokines levels in HEKa cells in a dose-dependent manner. In addition, SSA promoted apoptosis and suppressed phosphorylation of NF-κB in vitro, which were restored by the ROS scavenger N-acetylcysteine (NAC). In imiquimod (IMQ)-induced mice, gavage with SSA markedly decreased Psoriasis Area and Severity Index (PASI) score and ameliorated epidermal hyperplasia through inhibition of NF-κB and NLRP3 signaling pathway. In conclusion, our studies demonstrate that SSA induces apoptosis and suppresses inflammation in HEKa cells and ameliorates IMQ-induced psoriasis in mice, making it a therapeutic candidate for psoriasis.