Upregulation of GPX4 drives ferroptosis resistance in scleroderma skin fibroblasts.

The pathogenesis of systemic sclerosis (SSC) fibrosis involves the rapid proliferation of skin fibroblasts, and current anti-fibrotic treatments are limited. This study investigated the relationship between ferroptosis and SSC skin fibroblasts. We observed that erastin-induced ferroptosis was suppressed in SSC fibroblasts. RSL3, a direct inhibitor of Glutathione Peroxidase 4 (GPX4), significantly reduced the viability of the fibroblasts, and upregulation of GPX4 in the SSC fibroblasts contributed to ferroptosis resistance. Furthermore, we demonstrated that transferrin receptor 1 (TfR1) was a crucial transporter for iron deposition in the fibroblasts. Collectively, our results highlight that GPX4 inhibition could enhance the sensitivity to ferroptosis by SSC fibroblasts, which showed distinct characteristics of iron metabolism that were not observed in normal fibroblasts in this study. Taken together, these results suggest that targeting ferroptosis could be a therapeutic strategy for the treatment of SSC.

Decreased HMGCS1 inhibits proliferation and inflammatory response of keratinocytes and ameliorates imiquimod-induced psoriasis via the STAT3/IL-23 axis.

Psoriasis is an immuno-inflammatory disease characterized by excessive keratinocyte proliferation, requiring extensive lipids. 3-hydroxy-3-methylglutaryl-coenzyme A synthase 1 (HMGCS1) is an essential enzyme in the mevalonate pathway, involved in cholesterol synthesis and the inflammatory response. However, the role of HMGCS1 in psoriasis has remained elusive. This study aims to elucidate the mechanism by which HMGCS1 controls psoriasiform inflammation. We discovered an increased abundance of HMGCS1 in psoriatic lesions when analyzing two Gene Expression Omnibus (GEO) datasets and confirmed this in psoriatic animal models and psoriatic patients by immunohistochemistry. In a TNF-α stimulated psoriatic HaCaT cell line, HMGCS1 was found to be overexpressed. Knockdown of HMGCS1 using siRNA suppressed the migration and proliferation of HaCaT cells. Mechanistically, HMGCS1 downregulation also reduced the expression of IL-23 and the STAT3 phosphorylation level. In imiquimod-induced psoriatic mice, intradermal injection of HMGCS1 siRNA significantly decreased the expression of HMGCS1 in the epidermis, which in turn led to an improvement in the Psoriasis Area and Severity Index score, epidermal thickening, and pathological Baker score. Additionally, expression levels of inflammatory cytokines IL-23, IL1-ß, chemokine CXCL1, and innate immune mediator S100A7-9 were downregulated in the epidermis. In conclusion, HMGCS1 downregulation improved psoriasis in vitro and in vivo through the STAT3/IL-23 axis.

Xanthohumol attenuates collagen synthesis in scleroderma skin fibroblasts by ROS/Nrf2/TGFß1/Smad3 pathway.

Skin fibrosis, the most obvious clinical manifestation of systemic sclerosis (SSc), has a high unmet need for treatment. Xanthohumol (Xn) has been shown to have beneficial effects on fibrotic diseases, but its efficacy in SSc remains unreported. This study aims to elucidate the effects and mechanisms of Xn on collagen synthesis in SSc skin fibroblasts (SScF). We found increased collagen production in SScF cultured in vitro, accompanied by dysregulated levels of oxidative stress. Cell experiments showed that Xn inhibited cell proliferation and promoted apoptosis. In addition, Xn was shown for the first time to upregulate reactive oxygen species (ROS) and nuclear factor erythroid 2-related factor 2 (Nrf2)levels in SScF, and when combined with the ROS scavenger N-acetylcysteine (NAC), Nrf2 expression was decreased. Importantly, we demonstrated that Xn significantly attenuated collagen synthesis by blocking the fibrotic classical transforming growth factor beta 1 (TGFß1)/Smad3 pathway, which interestingly was upregulated when combined with the Nrf2 inhibitor 385. Taken together, Xn suppressed the TGFß1/Smad3 pathway to ameliorate collagen overproduction by promoting ROS-induced oxidative stress damage and activating Nrf2, suggesting that Xn administration may be an emerging therapeutic strategy for skin fibrosis in SSc.

Changes in Influenza Activities Impacted by NPI Based on 4-Year Surveillance in China: Epidemic Patterns and Trends.

BACKGROUND: Since the Non-pharmaceutical Intervention (NPI) by COVID-19 emerged, influenza activity has been somewhat altered. OBJECTIVES: The aim of this study was to explore changes in influenza activities in the context of COVID-19 based on the sentinel hospitals/units in Guangdong, southern China. METHODS: The surveillance data in influenza-like illness (ILI) were collected from 21 cities in Guangdong between September 2017 and August 2021, while 43 hospitals/units were selected to analyze the predominant types of influenza, population characteristics, and seasonal features by three methods (the concentration ratio, the seasonal index, and the circulation distribution), based on a descriptive epidemiological approach. RESULTS: During the four consecutive influenza seasons, a total of 157345 ILIs were tested, of which 9.05% were positive for influenza virus (n = 14238), with the highest positive rates for both IAV (13.20%) and IBV (5.41%) in the 2018-2019 season. After the emergence of COVID-19, influenza cases decreased near to zero from March 2020 till March 2021, and the dominant type of influenza virus changed from IAV to IBV. The highest positive rate of influenza existed in the age-group of 5 ~ < 15 years in each season for IAV (P < 0.001), which was consistent with that for IBV (P < 0.001). The highest annual positive rates for IBV emerged in eastern Guangdong, while the highest annual positive rates of IAV in different seasons existed in different regions. Furthermore, compared with the epidemic period (ranged from December to June) during 2017-2019, the period ended three months early (March 2020) in 2019-2020, and started by five months behind (April 2021) during 2020-2021. CONCLUSION: The highest positive rates in 5 ~ < 15 age-group suggested the susceptible in this age-group mostly had infected with infected B/Victoria. Influenced by the emergence of COVID-19 and NPI responses, the epidemic patterns and trends of influenza activities have changed in Guangdong, 2017-2021.

Metabolic profiling of urinary exosomes for systemic lupus erythematosus discrimination based on HPL-SEC/MALDI-TOF MS.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease which leads to the formation of immune complex deposits in multiple organs and has heterogeneous clinical manifestations. Currently, exosomes for liquid biopsy have been applied in diagnosis and monitoring of diseases, whereas SLE discrimination based on exosomes at the metabolic level is rarely reported. Herein, we constructed a protocol for metabolomic study of urinary exosomes from SLE patients and healthy controls (HCs) with high efficiency and throughput. Exosomes were first obtained by high-performance liquid size-exclusion chromatography (HPL-SEC), and then metabolic fingerprints of urinary exosomes were extracted by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) with high throughput and high efficency. With the statistical analysis by orthogonal partial least-squares discriminant analysis (OPLS-DA) model, SLE patients were efficiently distinguished from HCs, the area under the curve (AUC) of the receiver characteristic curve (ROC) was 1.00, and the accuracy of the unsupervised clustering heatmap was 90.32%. In addition, potential biomarkers and related metabolic pathways were analyzed. This method, with the characteristics of high throughput, high efficiency, and high accuracy, will provide the broad prospect of exosome-driven precision medicine and large-scale screening in clinical applications.

Artesunate alleviates psoriasis-like dermatitis by reducing interleukin-23 expression in tumor necrosis factor-alpha-induced HaCaT cells.

Artesunate (ART), an antimalarial drug with a multifunctional immunomodulatory effect, reduces psoriasis disease. ART can alleviate psoriasis-like dermatitis in mice but has no effect on proinflammatory cytokines in the blood. Thus, we hypothesized that the skin might be the target tissue of ART during the treatment of psoriasis. The interleukin (IL)-23/IL-17 axis has a key role in the pathogenesis of psoriasis. However, whether and how ART manipulates the IL-23 signal during psoriasis is unknown. This study found that IL-23 is highly expressed in the epidermis of psoriasis lesions and positively correlated with histological neutrophil infiltration and clinical psoriasis area and severity index (PASI) scores. Furthermore, ART inhibits the migration and cell cycle, as well as tumor necrosis factor-alpha (TNF-α)-induced IL-23 expression in HaCaT cells in a dose-dependent manner, probably through interference with the nuclear factor kappa B (NF-κB) signalling pathway. Animal experiments in imiquimod (IMQ)-induced psoriasis-like mice model also suggested that ART dose-dependently reduces IL-23 in the epidermis and ameliorates neutrophil infiltration. These findings thus provide further molecular evidence supporting ART as a promising drug for psoriasis in clinic.

Progress in research on mesenchymal stem cells and their extracellular vesicles for treating fibrosis in systemic sclerosis.

Systemic sclerosis (SSc) refers to an autoimmune disease characterized by immune dysfunction, vascular endothelial damage, and multi-organ fibrosis. Thus far, this disease is incurable, and its high mortality rate is significantly correlated with fibrotic events. Fibrosis has been confirmed as a difficult clinical treatment area that should be urgently treated in clinical medicine. Mesenchymal stem cells (MSCs) exhibit immunomodulatory, pro-angiogenic, and anti-fibrotic functions. MSCs-derived extracellular vesicles (EVs) have aroused rising interest as a cellular component that retains the functions of MSCs while circumventing the possible adverse effects of MSCs. Moreover, EVs have great potential in treating SSc. In this study, the current research progress on MSCs and their EVs for treating fibrosis in SSc was reviewed, with an aim to provide some reference for future MSCs and their EVs in treating SSc.

The shared biomarkers and pathways of systemic lupus erythematosus and metabolic syndrome analyzed by bioinformatics combining machine learning algorithm and single-cell sequencing analysis.

Background: Systemic lupus erythematosus (SLE) is one of the most prevalent systemic autoimmune diseases, and metabolic syndrome (MetS) is the most common metabolic disorder that contains hypertension, dyslipidemia, and obesity. Despite clinical evidence suggested potential associations between SLE and MetS, the underlying pathogenesis is yet unclear. Methods: The microarray data sets of SLE and MetS were obtained from the Gene Expression Omnibus (GEO) database. To identify the shared genes between SLE and MetS, the Differentially Expressed Genes (DEGs) analysis and the weighted gene co-expression network analysis (WGCNA) were conducted. Then, the GO and KEGG analyses were performed, and the protein-protein interaction (PPI) network was constructed. Next, Random Forest and LASSO algorithms were used to screen shared hub genes, and a diagnostic model was built using the machine learning technique XG-Boost. Subsequently, CIBERSORT and GSVA were used to estimate the correlation between shared hub genes and immune infiltration as well as metabolic pathways. Finally, the significant hub genes were verified using single-cell RNA sequencing (scRNA-seq) data. Results: Using limma and WGCNA, we identified 153 shared feature genes, which were enriched in immune- and metabolic-related pathways. Further, 20 shared hub genes were screened and successfully used to build a prognostic model. Those shared hub genes were associated with immunological and metabolic processes in peripheral blood. The scRNA-seq results verified that TNFSF13B and OAS1, possessing the highest diagnostic efficacy, were mainly expressed by monocytes. Additionally, they showed positive correlations with the pathways for the metabolism of xenobiotics and cholesterol, both of which were proven to be active in this comorbidity, and shown to be concentrated in monocytes. Conclusion: This study identified shared hub genes and constructed an effective diagnostic model in SLE and MetS. TNFSF13B and OAS1 had a positive correlation with cholesterol and xenobiotic metabolism. Both of these two biomarkers and metabolic pathways were potentially linked to monocytes, which provides novel insights into the pathogenesis and combined therapy of SLE comorbidity with MetS.

Artesunate alleviates imiquimod-induced psoriasis-like dermatitis in BALB/c mice.

Artesunate (ART), a derivative of artemisinin, is a medication to treat malaria. Beyond that, the anti-inflammatory and immunoregulatory activities of ART have been identified in autoimmune diseases. However, whether ART functions in psoriasis-like dermatitis induced by imiquimod (IMQ, a TLR7/8 agonist) is currently unkown. There, we found that the cumulative score, epidermal thickening and expression of Ki-67 of ART-treated BALB/c mice were significantly lower than those in the IMQ psoriatic model group. In addition, ART treatment ameliorated mice from systemic inflammation. Mechanistically, ART reduced γδ T cells in draining lymph nodes, which might be benefit the improvement of dermatitis. These findings suggested that ART could be a promising drug of psoriasis in clinic.

Identification of Mutation Regions on NF1 Responsible for High- and Low-Risk Development of Optic Pathway Glioma in Neurofibromatosis Type I.

Neurofibromatosis type I is a rare neurocutaneous syndrome resulting from loss-of-function mutations of NF1. The present study sought to determine a correlation between mutation regions on NF1 and the risk of developing optic pathway glioma (OPG) in patients with neurofibromatosis type I. A total of 215 patients with neurofibromatosis type I, from our clinic or previously reported literature, were included in the study after applying strict inclusion and exclusion criteria. Of these, 100 patients with OPG were classified into the OPG group and 115 patients without OPG (aged ≥ 10 years) were assigned to the Non-OPG group. Correlation between different mutation regions and risk of OPG was analyzed. The mutation clustering in the 5' tertile of NF1 was not significantly different between OPG and Non-OPG groups (P = 0.131). Interestingly, patients with mutations in the cysteine/serine-rich domain of NF1 had a higher risk of developing OPG than patients with mutations in other regions [P = 0.019, adjusted odds ratio (OR) = 2.587, 95% confidence interval (CI) = 1.167-5.736], whereas those in the HEAT-like repeat region had a lower risk (P = 0.036, adjusted OR = 0.396, 95% CI = 0.166-0.942). This study confirms a new correlation between NF1 genotype and OPG phenotype in patients with neurofibromatosis type I, and provides novel insights into molecular functions of neurofibromin.

Charged amino acid variability related to N-glyco -sylation and epitopes in A/H3N2 influenza: Hem -agglutinin and neuraminidase.

BACKGROUND: The A/H3N2 influenza viruses circulated in humans have been shown to undergo antigenic drift, a process in which amino acid mutations result from nucleotide substitutions. There are few reports regarding the charged amino acid mutations. The purpose of this paper is to explore the relations between charged amino acids, N-glycosylation and epitopes in hemagglutinin (HA) and neuraminidase (NA). METHODS: A total of 700 HA genes (691 NA genes) of A/H3N2 viruses were chronologically analyzed for the mutational variants in amino acid features, N-glycosylation sites and epitopes since its emergence in 1968. RESULTS: It was found that both the number of HA N-glycosylation sites and the electric charge of HA increased gradually up to 2016. The charges of HA and HA1 increased respectively 1.54-fold (+7.0 /+17.8) and 1.08-fold (+8.0/+16.6) and the number of NGS in nearly doubled (7/12). As great diversities occurred in 1990s, involving Epitope A, B and D mutations, the charged amino acids in Epitopes A, B, C and D in HA1 mutated at a high frequency in global circulating strains last decade. The charged amino acid mutations in Epitopes A (T135K) has shown high mutability in strains near years, resulting in a decrease of NGT135-135. Both K158N and K160T not only involved mutations charged in epitope B, but also caused a gain of NYT158-160. Epitope B and its adjacent N-glycosylation site NYT158-160 mutated more frequently, which might be under greater immune pressure than the rest. CONCLUSIONS: The charged amino acid mutations in A/H3N2 Influenza play a significant role in virus evolution, which might cause an important public health issue. Variability related to both the epitopes (A and B) and N-glycosylation is beneficial for understanding the evolutionary mechanisms, disease pathogenesis and vaccine research.

A humoral immunity survey following the 2012 influenza season after the pH1N1 pandemic in Guangzhou, China.

According to pathogenic surveillance data during the first half of 2012, the H3N2 influenza virus was prevalent in Guangdong, China, but no pandemic H1N1 (pH1N1) virus was detected. This study aimed to measure the seroprevalence of pH1N1 and H3N2 infection following the influenza epidemic in 2012. We collected serum samples by stratified random sampling in a cross-sectional survey from August, 2012 to October, 2012. Antibody titers against H3N2, pH1N1, and influenza B antigens were measured by the hemagglutination inhibition (HI) assay, and age-specific seroprevalence and non-immunity were calculated. A total of 566 serum samples were collected from subjects who had not received an influenza vaccination. The seroprevalence of H3N2, pH1N1, and influenza B were 61.7%, 31.3%, and 40.4%, respectively, while non-immunity was calculated to be 9.2%, 40.6%, and 27.0%, respectively. The highest recorded seroprevalence was 86.0% for H3N2 in the 6-15 year age group, while the lowest was 14.6% for pH1N1 in the 60+ age group. Non-immunity fractions were 44.4% and 53.5% in the 0-6 and 60+ age groups, respectively. In conclusion, the seroprevalence of pH1N1 remained below 50% in all age groups following the 2012 influenza season. These data suggest that vaccination against pH1N1 antigens should be conducted, especially in the older age groups, before the next influenza season.