Oxidative Stress Induced by High Salt Diet—Possible Implications for Development and Clinical Manifestation of Cutaneous Inflammation and Endothelial Dysfunction in Psoriasis vulgaris

Adding salt to foods and risk of psoriasis: A prospective cohort study

BACKGROUND

High salt intake may play a critical role in the etiology of psoriasis. Yet, evidence on the association of high salt intake with risk of psoriasis is limited.

OBJECTIVE

To estimate the association between frequency of adding salt to foods and risk of psoriasis.

METHODS

We conducted a prospective cohort study of 433,788 participants from the UK Biobank. Hazard ratios (HRs) and their 95 % confidence intervals (CIs) for risk of psoriasis in relation to frequency of adding salt to foods were estimated using multivariable Cox proportional hazards models. We further evaluated the joint association of adding salt to foods and genetic susceptibility with risk of psoriasis. We conducted a mediation analysis to assess how much of the effect of adding salt to foods on risk of psoriasis was mediated through several selected mediators.

RESULTS

During a median of 14.0 years of follow-up, 4279 incident cases of psoriasis were identified. In the multivariable-adjusted model, a higher frequency of adding salt to foods was significantly associated with an increased risk of psoriasis ("always" versus "never/rarely" adding salt to foods, HR = 1.25, 95 % CI: 1.10, 1.41). The observed positive association was generally similar across subgroups. In the joint association analysis, we observed that participants with a high genetic risk (above the second tertile) and the highest frequency of adding salt to foods experienced 149 % higher risk of psoriasis, when compared with participants with a low genetic risk (below the first tertile) and the lowest frequency of adding salt to foods (HR = 2.49, 95 % CI: 2.05, 3.02). Mediation analysis revealed that 1.8 %-3.2 % of the positive association between frequency of adding salt and risk of psoriasis was statistically significantly mediated by obesity and inflammatory biomarkers such as C-reactive protein and systemic immune-inflammation index (all P values < 0.004).

CONCLUSIONS

Our study demonstrated a positive association between frequency of adding salt to foods and risk of psoriasis. The positive association was independent of multiple other risk factors, and may be partially mediated through obesity and inflammation.

GSK2334470 attenuates high salt-exacerbated rheumatoid arthritis progression by restoring Th17/Treg homeostasis

High salt (HS) consumption is a risk factor for multiple autoimmune disorders via disturbing immune homeostasis. Nevertheless, the exact mechanisms by which HS exacerbates rheumatoid arthritis (RA) pathogenesis remain poorly defined. Herein, we found that heightened phosphorylation of PDPK1 and SGK1 upon HS exposure attenuated FoxO1 expression to enhance the glycolytic capacity of CD4 T cells, resulting in strengthened Th17 but compromised Treg program. GSK2334470 (GSK), a dual PDPK1/SGK1 inhibitor, effectively mitigated the HS-induced enhancement in glycolytic capacity and the overproduction of IL-17A. Therefore, administration of GSK markedly alleviated HS-exacerbated RA progression in collagen-induced arthritis (CIA) model. Collectively, our data indicate that HS consumption subverts Th17/Treg homeostasis through the PDPK1-SGK1-FoxO1 signaling, while GSK could be a viable drug against RA progression in clinical settings.

Orientin alleviates the inflammatory response in psoriasis like dermatitis in BALB/c mice by inhibiting the MAPK signaling pathway

BACKGROUND

Psoriasis, a chronic inflammatory condition of the skin, is characterized by an atypical proliferation of epidermal keratinocytes and immune cell infiltration. Orientin is a flavonoid monomer with potent anti-inflammatory activities. However, the therapeutic effects of orientin on psoriasis and the underlying mechanisms have not been elucidated.

OBJECTIVE

To investigate the therapeutic effect of orientin on psoriasis and the underlying mechanisms using network pharmacology and experimental studies.

METHODS

A psoriasis-like mouse model was established using imiquimod (IMQ). Lipopolysaccharide (LPS) was used to stimulate the RAW264.7 and HaCaT cells in vitro. The therapeutic effects of orientin and the underlying mechanism were analyzed using histopathological, immunohistochemical, quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay, flow cytometry, and western blotting analyses.

RESULTS

Orientin ameliorated skin lesions and suppressed keratinocyte proliferation and immune cell infiltration in the IMQ-induced psoriasis-like mouse model. Additionally, orientin inhibited the secretion of the pro-inflammatory factors interleukin (IL)-1β, tumor necrosis factor (TNF)-α, IL-6, IL-8, IL-17, and IL-23 in the psoriasis-like mouse model and LPS-induced RAW264.7 and HaCaT cells. Furthermore, orientin mitigated the LPS-induced upregulation of reactive oxygen species and downregulation of IL-10 and glutathione levels. Orientin alleviated inflammation by downregulating the MAPK signaling pathway.

CONCLUSION

Orientin alleviated psoriasis-like dermatitis by suppressing the MAPK signaling pathway, suggesting that orientin is a potential therapeutic for psoriasis.

Role of Ubiquitin-conjugating enzyme E2 (UBE2) in two immune-mediated inflammatory skin diseases: a mendelian randomization analysis

Psoriasis vulgaris (PV) and Atopic dermatitis (AD) are the two major types of immune-mediated inflammatory skin disease (IMISD). Limited studies reported the association between Ubiquitin-conjugating enzyme E2 (UBE2) and IMISD. We employed a two-sample Mendelian randomization (MR) study to assess the causality between UBE2 and PV & AD. UBE2 association genome-wide association study (GWAS) data were collected. The inverse variance weighted (IVW) method was utilized as the principal method in our Mendelian randomization (MR) study, with additional using the MR-Egger, weighted median, simple mode, and weighted mode methods. The MR-Egger intercept test, Cochran's Q test, MR-Pleiotropy RESidual Sum and Outlier (MR-PRESSO) and leave-one-out analysis were conducted to identify heterogeneity and pleiotropy, colocalization analysis was also performed. The results showed that Ubiquitin-conjugating enzyme E2 variant 1 (UBE2V1) was causally associated with PV (OR = 0.909, 95% CI: 0.830-0.996, P = 0.040), Ubiquitin-conjugating enzyme E2 L3 (UBE2L3) was causally associated with AD (OR = 0.799, 95% CI: 0.709-0.990, P < 0.001). Both UBE2V1 and UBE2L3 may play protective roles in patients with PV or AD, respectively. No other significant result has been investigated. No heterogeneity or pleiotropy was observed. This study provided new evidence of the relationship between UBE2V1 and PV, UBE2L3 and AD. Our MR suggested that UBE2V1 plays an inhibitory role in PV progression, UBE2L3 plays an inhibitory role in AD. These could be novel and effective ways to treat PV and AD.

Signaling pathways and targeted therapies for psoriasis

Psoriasis is a common, chronic, and inflammatory skin disease with a high burden on individuals, health systems, and society worldwide. With the immunological pathologies and pathogenesis of psoriasis becoming gradually revealed, the therapeutic approaches for this disease have gained revolutionary progress. Nevertheless, the mechanisms of less common forms of psoriasis remain elusive. Furthermore, severe adverse effects and the recurrence of disease upon treatment cessation should be noted and addressed during the treatment, which, however, has been rarely explored with the integration of preliminary findings. Therefore, it is crucial to have a comprehensive understanding of the mechanisms behind psoriasis pathogenesis, which might offer new insights for research and lead to more substantive progress in therapeutic approaches and expand clinical options for psoriasis treatment. In this review, we looked to briefly introduce the epidemiology, clinical subtypes, pathophysiology, and comorbidities of psoriasis and systematically discuss the signaling pathways involving extracellular cytokines and intracellular transmission, as well as the cross-talk between them. In the discussion, we also paid more attention to the potential metabolic and epigenetic mechanisms of psoriasis and the molecular mechanistic cascades related to its comorbidities. This review also outlined current treatment for psoriasis, especially targeted therapies and novel therapeutic strategies, as well as the potential mechanism of disease recurrence.

High salt intake damages myocardial viability and induces cardiac remodeling via chronic inflammation in the elderly

Background

The heart is an important target organ for the harmful effects of high dietary salt intake. However, the effects and associations of high salt intake on myocardial viability, cardiac function changes, and myocardial remodeling are unclear.

Methods

A total of 3,810 participants aged 60 years and older were eligible and enrolled from April 2008 to November 2010 and from August 2019 to November 2019 in the Shandong area of China. Salt intake was estimated using 24-h urine collection consecutively for 7 days. Myocardial strain rates, cardiac function and structure, and serum high-sensitivity C-reactive protein (hsCRP) levels were assessed. Participants were classified into low (n = 643), mild (n = 989), moderate (n = 1,245), and high (n = 933) groups, corresponding to < 6, 6–9, 9–12, and >12 g/day of salt intake, respectively, depending on the salt intake estimation.

Results

The global early diastolic strain rate (SRe) and late diastolic strain rate (SRa) in the high group were 1.58 ± 0.26, 1.38 ± 0.24. respectively, and significantly lower compared with the low, mild, and moderate groups (all P < 0.05). The global systolic strain rate (SRs) in the high group was −1.24 ± 0.24, and it was higher than those in the low, mild, and moderate groups (all P < 0.05). Salt intake was independently and positively correlated with global SRs, Tei index, and the parameters of left ventricular structure separately; negatively correlated with global SRe and SRa, left ventricular short axis shortening rate, left ventricular ejection fraction after adjusting for confounders (all P_adjusted < 0.001). Hayes process analyses demonstrated that the mediating effects of hsCRP on global SRe, SRa, and SRs; Tei index; and left ventricular remodeling index were −0.013 (95% CI: −0.015 to −0.010), −0.010 (−0.012 to −0.008), 0.008 (0.006–0.010), 0.005 (0.003–0.006), and 0.010 (0.009–0.012), respectively (all P_adjusted < 0.001).

Conclusion

Our data indicate that excess salt intake is independently associated with the impairment in myocardial viability and cardiac function, as well as myocardial remodeling. Chronic inflammation might play a mediating role in the association between high salt intake and cardiac function damage and myocardial remodeling.