Objectives: To unveil the role of SIRT1 in limiting oxidative stress in psoriasis and to further discuss the therapeutic prospects of salidroside in psoriasis. Methods: Literature from 2002 to 2019 was searched with “psoriasis”, “oxidative stress”, “SIRT1”, “salidroside” as the key words. Then, Oxidative stress in psoriasis and the role of SIRT1 were summarized and the potential role of salidroside in the disease was speculated. Results: Oxidative stress might contribute to the pathogenesis of psoriasis. High levels of ROS produced during oxidative stress lead to the release of inflammatory mediators, that, in turn, induce angiogenesis and excessive proliferation of keratinocytes. SIRT1 is a member of the sirtuin family, of which the activation lead to the inhibition of such oxidative stress signaling pathways MAPK, NF-κB, and STAT3, down-regulation of inflammatory factors, suppression of inflammation and keratinocyte hyperproliferation, and inhibition of angiogenesis. Salidroside, the main ingredient of Rhodiola, is known to exert antioxidant roles, which has been attributed to SIRT1 activation. Conclusion: Salidroside might inhibit oxidative stress singling pathways via SIRT1 activation, and could be as an ideal candidate for management of psoriasis.
18 June 2019 in Scandinavian Journal of Immunology
Pemphigus vulgaris (PV) is an autoimmune disease characterized by the production of IgG autoantibodies owing to an imbalance in the Th1/Th2 and Th17/Tregs cell pathways. The role of gut microbiota in the development of immune system and autoimmune diseases has been unraveled in the last two decades. However, data pertaining to gut microbiota of PV patients is largely lacking. We aimed to compare the gut microbiota of PV patients and healthy controls and assessed potential correlation with circulating cytokines of Th1/Th2/Th17 cell. Faecal bacterial diversity was analysed in 18 PV patients and 14 age‐ and gender‐matched healthy individuals using hypervariable tag sequencing of the V3‐V4 region of the 16S rRNA gene. Plasma levels of 20 inflammatory cytokines were assessed using the Luminex screening system. As a result, we identified 10 differentially abundant taxa between patients and controls. At the genera level, Lachnospiracea_incertae_sedis and Coprococcus decreased, while Granulicatella, Flavonifractor enriched in PV. Plasma levels of C5a, interleukin (IL)‐2R, IL‐6, IL‐8, IL‐7, IL‐1β, IL17A, IL‐5 and IL‐21 were significantly increased in PV Flavonifractor exhibited a positive correlation with C5a, IL‐6, IL‐8, IL‐7, IL‐1β, IL17A and IL‐21. Lachnospiracea_incertae_sedis and Coprococcus showed a negative correlation with IL‐17A. Our results are consistent with the hypothesis that PV patients have gut microbial dysbiosis which might contribute to the immune disorder and the development of PV.
Purpose YKL-40 is a chitinase-like protein expressed in multiple tissues including liver and is reported as a fibrosis marker. This study aimed to determine whether YKL-40 could serve as a diagnostic marker for the assessment of liver fibrosis in chronic hepatitis B patients with normal and mildly elevated ALT. Methods Six hundred and eighty-five patients with chronic hepatitis B infection were enrolled in this study from October 2013 to March 2016. All patients underwent liver biopsy and then staged based on Ishak histological system. Serum YKL-40 levels were measured by Human Magnetic Luminex Assays. Results Among chronic hepatitis B patients with normal and mildly elevated ALT, almost more than 30% of patients have significant liver fibrosis. Serum YKL-40 levels increased significantly in parallel with the progression of fibrosis in patients with ALT less than two times the upper limit of normal range (P < 0.0001). Multivariate analysis revealed that serum YKL-40, hyaluronic acid, PLT, and AST were independently associated with significant fibrosis. We established a novel YKL-40-based fibrosis model for patients with ALT less than two times the upper limit of normal range (ULN). YKL-40 model was superior to APRI, FIB-4, Forns’ index, and Hui model for diagnosis of significant fibrosis in patients with ALT < 2ULN, with AUROCs of 0.786 [95% confidence interval (CI) 0.726–0.846] in the training group, 0.831 (95%CI 0.752–0.910) in the validation group and 0.801 (95%CI 0.753–0.849) in the entire cohort. Conclusion Serum YKL-40 is a feasible biomarker of liver fibrosis in chronic hepatitis B patients. YKL-40 model was superior to APRI, FIB-4, Forns’ index and Hui model for diagnosis of significant fibrosis in patients with normal and mildly elevated ALT.
Objective: The aim of this research was to systematically investigate the effects of endothelial mesenchymal transition (EndMT) induced by hypoxia on the skin microvascular remodeling of systemic sclerosis (SSc) and the underlying mechanism. Methods: Skin tissues from SSc patients and controls were collected for isobaric tags for the relative and absolute quantification (iTRAQ)-based proteomics and immunohistochemical test. Human microvascular endothelial cell line-1 (HMEC-1) cultured in hypoxic or normal conditions was treated by tamoxifen or bevacizumab. Results: The iTRAQ-based proteomics indicated a significantly upregulated hypoxia-inducible factor-1 (HIF-1) signal in SSc samples. The immunohistochemical results demonstrated the significant downregulation of CD31, the positive staining of α-smooth muscle actin (α-SMA), HIF-1α, and vascular endothelial growth factor (VEGF-a) in SSc skin tissues, compared with control samples. Consistent with these observations, HMEC-1 cells cultured under hypoxic conditions exhibited a significant decrease in CD31 and VE-cadherin expression, alongside a marked increase in the expression of α-SMA and fibronectin, as well as a distinct upregulation of HIF-1α and VEGF-a, when compared with those under normal conditions. It is noteworthy that the inhibition of HIF-1α by tamoxifen effectively downregulated the hypoxic induction of VEGF-a and α-SMA while rescuing the hypoxic suppression of CD31. In addition, the VEGF-a inhibitor bevacizumab treatment had the same effect on the hypoxic expression of α-SMA and CD31, as a tamoxifen intervention, but did not reduce HIF-1α. Conclusion: These results suggest that the HIF-1α/VEGF signaling pathway can have a critical role in mediating the effect of hypoxia-induced EndMT on the skin microvascular remodeling of SSc.
Background: The depletion of beneficial bacteria in the gut has been found in patients with acne vulgaris, and in previous studies, the supplement of Lactobacillus rhamnosus led to the improvement of adult acne. Nevertheless, the potential mechanism of L. rhamnosus in the amelioration of acne vulgaris has not been elucidated yet.Methods: To mimic the human intestinal environment, a pseudo-germ-free rat model was used, and then gut microbiota from healthy individuals and acne patients were transplanted into rats. The effects of L. rhamnosus and tryptophan (Trp) metabolites on a rat acne model were investigated by gavage. Then, 16S rRNA analysis and targeted measurement of metabolites were performed to discover the differences in gut microbiota and metabolites between groups. Finally, HaCaT cells pretreated with Cutibacterium acnes were employed to validate the effect and mechanism of Trp metabolites on acne.Results: L. rhamnosus significantly improved acne-like symptoms in rats by suppressing the level of inflammatory cytokines such as IL-1β, IL-6, and TNF-α. L. rhamnosus induced an increase in the production of indole-3-acetic acid (IAA) and indole via targeted Trp metabolic analyses. Furthermore, L. rhamnosus promoted bacterial diversity and also enhanced the Firmicutes/Bacteroidota (F/B) ratio, which was positively related to both IAA and indole. Finally, the roles of IAA and indole in alleviating acne vulgaris were confirmed both in vitro and in vivo, which could be reversed by AhR inhibitors.Conclusion: Our study demonstrated that L. rhamnosus could exert its therapeutic effects on acne vulgaris by modulating the gut microbiota and regulating associated Trp metabolites.
Acne vulgaris is a chronic inflammatory skin disease in which the influence of gut microbiota has been implicated but without clarification of mechanisms. Gut microbiota may exert such an influence via metabolites, particularly those of tryptophan. End metabolites of tryptophan activate receptors, including aryl hydrocarbon, G protein-coupled, and pregnane X receptors to stabilize the immune microenvironment and intestinal mucosal homeostasis. Any impact on the pathogenesis of acne vulgaris remains unclear. The current review collates recent advances concerning potential roles of tryptophan metabolism in mediating skin inflammation, follicular sebaceous gland function and intestinal permeability, all of which influence the pathogenesis of acne vulgaris. The aim was to improve understanding of the pathogenesis of acne vulgaris and to expose therapeutic opportunities.