Epigenetic modification of a pectin methylesterase gene activates apoplastic iron reutilization in tomato roots.

Iron (Fe) distribution and reutilization are crucial for maintaining Fe homeostasis in plants. Here, we demonstrate that the tomato (Solanum lycopersicum) Colorless nonripening (Cnr) epimutant exhibits increased Fe retention in cell wall pectin due to an increase in pectin methylesterase (PME) activity. This ultimately leads to Fe deficiency responses even under Fe-sufficient conditions when compared to the wild type (WT). Whole-genome bisulfite sequencing revealed that modifications to cell wall-related genes, especially CG hypermethylation in the intron region of PECTIN METHYLESTERASE53 (SlPME53), are involved in the Cnr response to Fe deficiency. When this intron hypermethylation of SlPME53 was artificially induced in WT, we found that elevated SlPME53 expression was accompanied by increased PME activity and increased pectin-Fe retention. The manipulation of SlPME53, either through overexpression in WT or knockdown in Cnr, influenced levels of pectin methylesterification and accumulation of apoplast Fe in roots. Moreover, CG hypermethylation mediated by METHYLTRANSFERASE1 (SlMET1) increased SlPME53 transcript abundance, resulting in greater PME activity and higher Fe retention in cell wall pectin. Therefore, we conclude that the Cnr mutation epigenetically modulates SlPME53 expression by SlMET1-mediated CG hypermethylation, and thus the capacity of the apoplastic Fe pool, creating opportunities for genetic improvement of crop mineral nutrition.

Changes in endemic patterns of respiratory syncytial virus infection in pediatric patients under the pressure of nonpharmaceutical interventions for COVID-19 in Beijing, China.

A series of nonpharmaceutical interventions (NPIs) was launched in Beijing, China, on January 24, 2020, to control coronavirus disease 2019. To reveal the roles of NPIs on the respiratory syncytial virus (RSV), respiratory specimens collected from children with acute respiratory tract infection between July 2017 and Dec 2021 in Beijing were screened by capillary electrophoresis-based multiplex PCR (CEMP) assay. Specimens positive for RSV were subjected to a polymerase chain reaction (PCR) and genotyped by G gene sequencing and phylogenetic analysis using iqtree v1.6.12. The parallel and fixed (paraFix) mutations were analyzed with the R package sitePath. Clinical data were compared using SPSS 22.0 software. Before NPIs launched, each RSV endemic season started from October/November to February/March of the next year in Beijing. After that, the RSV positive rate abruptly dropped from 31.93% in January to 4.39% in February 2020; then, a dormant state with RSV positive rates ≤1% from March to September, a nearly dormant state in October (2.85%) and November (2.98%) and a delayed endemic season in 2020, and abnormal RSV positive rates remaining at approximately 10% in summer until September 2021 were detected. Finally, an endemic RSV season returned in October 2021. There was a game between Subtypes A and B, and RSV-A replaced RSV-B in July 2021 to become the dominant subtype. Six RSV-A and eight RSV-B paraFix mutations were identified on G. The percentage of severe pneumonia patients decreased to 40.51% after NPIs launched. NPIs launched in Beijing seriously interfered with the endemic season of RSV.

Integrative Analysis Developing and Validating Potential Candidate Biomarkers for Cancer Stemness Features of Pan-Renal Cell Carcinoma.

In our study, 49 key genes significantly associated with renal cell carcinoma (RCC) stemness were obtained. Next, we developed a molecular prognostic signature associated with stemness features of pan-RCC. The difference in overall survival (OS) between the high- and low-risk groups was statistically significant (p < .05). The area under the receiver operating characteristic curve for 1-year OS, 5-year OS, and 10-year OS was 0.759, 0.712, and 0.918, respectively. The results of validation in The Cancer Genome Atlas cohort and International Cancer Genome Consortium cohort revealed the predictive capability of this signature. Furthermore, we selected three genes and further validation showed that these three hub genes were potential hub biomarkers for pan-RCC stemness features.

Exosomal MiR-381 from M2-polarized macrophages attenuates urethral fibroblasts activation through YAP/GLS1-regulated glutaminolysis.

OBJECTIVE AND DESIGN: Post-traumatic urethral stricture is a clinical challenge for both patients and clinicians. Targeting glutamine metabolism to suppress excessive activation of urethral fibroblasts (UFBs) is assumed to be a potent and attractive strategy for preventing urethral scarring and stricture. MATERIAL OR SUBJECTS: In cellular experiments, we explored whether glutaminolysis meets the bioenergetic and biosynthetic demands of quiescent UFBs converted into myofibroblasts. At the same time, we examined the specific effects of M2-polarized macrophages on glutaminolysis and activation of UFBs, as well as the mechanism of intercellular signaling. In addition, findings were further verified in vivo in New Zealand rabbits. RESULTS: It revealed that glutamine deprivation or knockdown of glutaminase 1 (GLS1) significantly inhibited UFB activation, proliferation, biosynthesis, and energy metabolism; however, these effects were rescued by cell-permeable dimethyl α-ketoglutarate. Moreover, we found that exosomal miR-381 derived from M2-polarized macrophages could be ingested by UFBs and inhibited GLS1-dependent glutaminolysis, thereby preventing excessive activation of UFBs. Mechanistically, miR-381 directly targets the 3'UTR of Yes-associated protein (YAP) mRNA to reduce its stability at the transcriptional level, ultimately downregulating expression of YAP, and GLS1. In vivo experiments revealed that treatment with either verteporfin or exosomes derived from M2-polarized macrophages significantly reduced urethral stricture in New Zealand rabbits after urethral trauma. CONCLUSION: Collectively, this study demonstrates that exosomal miR-381 from M2-polarized macrophages reduces myofibroblast formation of UFBs and urethral scarring and stricture by inhibiting YAP/GLS1-dependent glutaminolysis.

Glutathione-dependent redox homeostasis is critical for chlorothalonil detoxification in tomato leaves.

Glutathione plays a critical role in plant growth, development and response to stress. It is a major cellular antioxidant and is involved in the detoxification of xenobiotics in many organisms, including plants. However, the role of glutathione-dependent redox homeostasis and associated molecular mechanisms regulating the antioxidant system and pesticide metabolism remains unclear. In this study, endogenous glutathione levels were manipulated by pharmacological treatments with glutathione synthesis inhibitors and oxidized glutathione. The application of oxidized glutathione enriched the cellular oxidation state, reduced the activity and transcript levels of antioxidant enzymes, upregulated the expression level of nitric oxide and Ca2+ related genes and the content, and increased the residue of chlorothalonil in tomato leaves. Further experiments confirmed that glutathione-induced redox homeostasis is critical for the reduction of pesticide residues. RNA sequencing analysis revealed that miRNA156 and miRNA169 that target transcription factor SQUAMOSA-Promoter Binding Proteins (SBP) and NUCLEAR FACTOR Y (NFY) potentially participate in glutathione-mediated pesticide degradation in tomato plants. Our study provides important clues for further dissection of pesticide degradation mechanisms via miRNAs in plants.

The transcription factor NAC102 confers cadmium tolerance by regulating WAKL11 expression and cell wall pectin metabolism in Arabidopsis.

Cadmium (Cd) toxicity severely limits plant growth and development. Moreover, Cd accumulation in vegetables, fruits, and food crops poses health risks to animals and humans. Although the root cell wall has been implicated in Cd stress in plants, whether Cd binding by cell wall polysaccharides contributes to tolerance remains controversial, and the mechanism underlying transcriptional regulation of cell wall polysaccharide biosynthesis in response to Cd stress is unknown. Here, we functionally characterized an Arabidopsis thaliana NAC-type transcription factor, NAC102, revealing its role in Cd stress responses. Cd stress rapidly induced accumulation of NAC102.1, the major transcript encoding functional NAC102, especially in the root apex. Compared to wild type (WT) plants, a nac102 mutant exhibited enhanced Cd sensitivity, whereas NAC102.1-overexpressing plants displayed the opposite phenotype. Furthermore, NAC102 localizes to the nucleus, binds directly to the promoter of WALL-ASSOCIATED KINASE-LIKE PROTEIN11 (WAKL11), and induces transcription, thereby facilitating pectin degradation and decreasing Cd binding by pectin. Moreover, WAKL11 overexpression restored Cd tolerance in nac102 mutants to the WT levels, which was correlated with a lower pectin content and lower levels of pectin-bound Cd. Taken together, our work shows that the NAC102-WAKL11 module regulates cell wall pectin metabolism and Cd binding, thus conferring Cd tolerance in Arabidopsis.

The Impacts of Genetic and Environmental Factors on the Progression of Chronic Pancreatitis.

BACKGROUND & AIMS: Both environmental factors, such as alcohol consumption and smoking, and genetic factors are strongly associated with the risk of developing chronic pancreatitis (CP). However, comprehensive understanding of their impacts on the progression of CP remains elusive. METHODS: A prospective cohort study was performed on a large cohort of CP patients with known genetic backgrounds. The cumulative incidence of pancreatic insufficiency after the onset of CP was analyzed using Kaplan-Meier survival curves. Multivariate Cox proportional hazards regression analysis also was performed. RESULTS: A total of 798 patients were enrolled in the study and followed up for 10.5 years. Rare pathogenic genotypes in the SPINK1, PRSS1, CTRC, or CFTR genes were identified in 410 (51.4%) patients. The development of pancreatic insufficiency was significantly earlier in patients with a history of smoking and/or alcohol consumption in both the positive (P < .001) and negative (P = .001) gene mutation groups. However, the development of pancreatic insufficiency did not differ significantly between patients with and without gene mutations despite alcohol and/or smoking status, with P values of .064 and .115, respectively. Multivariate Cox regression analysis showed that age at onset of CP (hazard ratio, [HR], 1.02; P < .001) and alcohol consumption (HR, 1.86; P < .001) were independent risk factors for the development of diabetes, while male sex (HR, 1.84; P = .022) and smoking (HR, 1.56; P = .028) were predictors of steatorrhea. CONCLUSIONS: Although rare pathogenic mutations in the 4 major susceptibility genes for CP were not correlated significantly with the development of pancreatic insufficiency, environmental factors (either alcohol consumption or smoking) significantly accelerated disease progression (ClinicalTrials.gov: NCT04574297).

Jasmonic acid promotes glutathione assisted degradation of chlorothalonil during tomato growth.

Glutathione (GSH) biosynthesis and regeneration play a significant role in the metabolism of chlorothalonil (CHT) in tomatoes. However, the specific regulatory mechanism of GSH in the degradation of CHT remains uncertain. To address this, we investigate the critical regulatory pathways in the degradation of residual CHT in tomatoes. The results revealed that the detoxification of CHT residue in tomatoes was inhibited by buthionine sulfoximine and oxidized glutathione pretreatment, which increased by 26% and 46.12% compared with control, respectively. Gene silencing of γECS, GS, and GR also compromised the CHT detoxification potential of plants, which could be alleviated by GSH application and decreased the CHT accumulation by 33%, 25%, and 21%, respectively. Notably, it was found that the jasmonic acid (JA) pathway participated in the degradation of CHT regulated by GSH. CHT residues reduced by 28% after application of JA. JA played a role downstream of the glutathione pathway by promoting the degradation of CHT residue in tomatoes via nitric oxide signaling and improving the gene expression of antioxidant and detoxification-related enzymes. This study unveiled a crucial regulatory mechanism of GSH via the JA pathway in CHT degradation in tomatoes and offered new insights for understanding residual pesticide degradation.

Identification of novel genes in testicular cancer microenvironment based on ESTIMATE algorithm-derived immune scores.

Testicular cancer is the most common solid malignancy among young men. We downloaded data of testicular cancer patients from The Cancer Genome Atlas database to find novel genes in the testicular cancer microenviroment based on ESTIMATE algorithm-derived immune scores. A total of 156 cases of testicular cancer were included in this study and 165 cases of normal testicular tissues were used. We divided the testicular cancer patients into high- and low-score groups based on their immune scores. We identified 1,226 differentially expressed genes (fold change > 2, false discovery rate < 0.05), including 688 downregulated genes and 538 upregulated genes, between these two groups. The top Gene Ontology terms were involved in the immune response-regulating cell surface receptor signaling pathway, immune response-activating cell surface receptor signaling pathway, external side of the plasma membrane, and receptor ligand activity. By performing the Kyoto Encyclopedia of Genes and Genomes analysis, we demonstrated that cAMP signaling pathway was highly enriched among these differentially expressed genes. High expression of LINC01564, LINC02208, ODAM, RNA5SP111, and RNU6-196P were found to be associated with poor overall survival. The expression of genes was further validated by the Human Protein Atlas and only ALB and IFNG were demonstrated to be differentially expressed between testis tissue and testicular cancer tissue.

LncRNA LINC00337 sponges mir-1285-3p to promote proliferation and metastasis of lung adenocarcinoma cells by upregulating YTHDF1.

BACKGROUND: Emerging studies have shown that long noncoding RNAs (lncRNAs) predominantly function in the carcinogenesis of multiple developing human tumors. The current study aimed to investigate the underlying mechanisms of LINC00337 in lung adenocarcinoma. METHODS: We analyzed TCGA and GTEx datasets and chose LINC00337 as the research object. Cell proliferation, cell apoptosis, cell cycle, migration, and invasion were detected in the gain and loss experiments of LINC00337 both in vitro and in vivo. Moreover, RNA pull-down, luciferase reporter assays, western blotting analysis, and rescue experiments were performed to investigate the underlying molecular mechanisms of LINC00337 function. RESULTS: LINC00337 expression was remarkably upregulated in lung adenocarcinoma. In addition, LINC00337 knockdown was shown to repress cell migration, invasion, and proliferation, as well as the cell cycle, and gear up apoptosis in lung adenocarcinoma in vitro and in vivo. With respect to the mechanism, LINC00337 knockdown boosted miR-1285-3p expression and then restrained YTHDF1 expression post-transcriptionally. Crucially, both miR-1285-3p decrement and YTHDF1 overexpression successfully reversed the influence on cell proliferation, migration, invasion, and apoptosis caused by LINC00337 shRNA. CONCLUSIONS: These results suggest that LINC00337 acts as an oncogenic lncRNA, targeting miR-1285-3p and regulating YTHDF1 expression, to promote the progression of lung adenocarcinoma.

SPINK1 mutations and risk of pancreatic cancer in a Chinese cohort.

OBJECTIVE: The relationship between SPINK1 and pancreatic cancer (PC) remains controversial. The current study aimed to determine the effect of SPINK1 mutations on PC development among patients with chronic pancreatitis (CP). METHODS: This is a prospective observational study including a large cohort of 965 CP patients with 11-year follow-up. Patients' demographic characteristics and clinical CP outcomes were documented in detail. Genetic testing was performed. The effect of SPINK1 mutations on the clinical development of PC was explored using Cox proportional hazards regression. Subgroup analyses conducted included the consideration of gender, onset age of CP (early- and late-onset), etiologies of CP, smoking, and alcoholic drinking status. RESULTS: PC was diagnosed in 2.5% (24/965) of patients, and the cumulative incidence rates were 0.2%, 0.8%, and 1.5% at 3, 5, and 10 years since the onset of CP, respectively. In this cohort, SPINK1 c.194+2T > C was the most common variant with a proportion of 39.1%. And the risk of PC development varied marginally between patients with and without SPINK1 mutations (Cox HR 0.39(0.14-1.04), P = 0.059). In the subgroup analyses, patients carrying SPINK1 mutations had a significantly lower risk of PC (Cox HR 0.18(0.04-0.80), P = 0.025) in the non-smoking group. SPINK1 mutations showed no significant effect in the other subgroups considered. CONCLUSIONS: CP patients harboring SPINK1 mutations do not have an elevated risk of PC development compared to mutation-negative CP patients. On the contrary, SPINK1 mutations may be a protective factor in non-smoking patients with CP.

Prevalence and Risk Factors for Osteopathy in Chronic Pancreatitis.

BACKGROUND AND AIMS: The high incidence of osteopathy among patients with chronic pancreatitis (CP) has garnered increased attention over recent years. The aims of this study were to assess the prevalence and risk factors for osteopathy in Chinese patients with CP. METHODS: This was a cross-sectional study of CP patients from a large center in China; patients were recruited between 31 January 2017 and 31 January 2018. Bone density and laboratory tests, including bone-related biochemical, inflammatory, and hormone parameters, were assessed prospectively. Differences between patients with and without osteopathy were analyzed. Logistic regression analysis was used to investigate associations between variables. RESULTS: In total, 104 CP patients were enrolled in this study (68.3% idiopathic and 31.7% alcoholic). According to the M-ANNHEIM classification, 87.5% of the patients were at an early stage (0-II). Osteopenia was diagnosed in 30.8% of patients and osteoporosis in 5.8%; thus, a total of 36.5% of patients presented with osteopathy. In multivariate analysis, the independent risk factors for osteopathy in CP patients were age (OR = 1.04; 95% CI = 1.00-1.08; P = 0.030), BMI (OR = 0.72; 95% CI = 0.58-0.89; P = 0.003), and PTH (OR = 0.96; 95% CI = 0.93-1.00; P = 0.022). CONCLUSIONS: This study is the first to report the prevalence of osteopathy in Chinese patients with CP. It found that age and low BMI are significant risk factors for osteopathy. Low PTH (but within the normal range) showed a weak association with osteopathy, which warrants further exploration.

A snapshot of public knowledge of novel coronavirus disease 2019: a web-based national survey.

BACKGROUND: Although the number of existing cases of coronavirus disease 2019 (COVID-19) in China has been decreasing since late February 2020, the number of confirmed cases abroad is surging. Improving public knowledge of COVID-19 is critical to controlling the pandemic. This study aimed to determine China's public knowledge of COVID-19 and the attitudes towards control measures. METHODS: A cross-sectional study was conducted over 48 h from 22:30 29 February 2020 to 22:30 2 March 2020 based on a self-administered web-based questionnaire. The survey was conducted on the WeChat network. Exponential non-discriminative snowball sampling was applied. The questionnaire was voluntarily completed by WeChat users. The questionnaire covered basic demographic information, public knowledge of the epidemiological and clinical characteristics of COVID-19, psychological state, and attitudes towards the overall control measures. The primary outcome was the China's public knowledge of COVID-19 and the attitudes towards control measures and secondary outcome was the psychological state of the public during this pandemic. RESULTS: The study included 10,905 participants and 10,399 valid questionnaires were included for analysis. Participants with tertiary education, younger participants and healthcare workers had better overall knowledge than other participants (all P < 0.05). Approximately 91.9% of the participants believed in person-to-person transmission and 39.1% believed in animal-to-person transmission. No significant correlation between anxiety and the number of regional existing confirmed cases was found, while participants in Hubei were more anxious than those in other regions. In general, 74.1% of the participants acknowledged the effectiveness of the overall control measures, and the percentage of participants with agreement with the overall control measures was negatively correlated with the number of regional existing confirmed cases (r = - 0.492, P = 0.007). CONCLUSIONS: In conclusion, the survey revealed that the Chinese public had overall good knowledge of COVID-19 except for those indeterminate knowledges. With dynamic changes in the global pandemic situation and more research, further studies should be conducted to explore changes in public knowledge and attitudes towards COVID-19 in the future. The media could be used in a strict and regular manner to publicize knowledge of such pandemics to halt their spread.

Development and validation of hub genes for lymph node metastasis in patients with prostate cancer.

Lymph node metastasis is one of the most important independent risk factors that can negatively affect the prognosis of prostate cancer (PCa); however, the exact mechanisms have not been well studied. This study aims to better understand the underlying mechanism of lymph node metastasis in PCa by bioinformatics analysis. We analysed a total of 367 PCa cases from the cancer genome atlas database and performed weighted gene co-expression network analysis to explore some modules related to lymph node metastasis. Gene Ontology analysis and pathway enrichment analysis were conducted for functional annotation, and a protein-protein interaction network was built. Samples from the International Cancer Genomics Consortium database were used as a validation set. The turquoise module showed the most relevance with lymph node metastasis. Functional annotation showed that biological processes and pathways were mainly related to activation of the processes of cell cycle and mitosis. Four hub genes were selected: CKAP2L, CDCA8, ERCC6L and ARPC1A. Further validation showed that the four hub genes well-distinguished tumour and normal tissues, and they were good biomarkers for lymph node metastasis of PCa. In conclusion, the identified hub genes facilitate our knowledge of the underlying molecular mechanism for lymph node metastasis of PCa.

Fatal outcome in a liver transplant recipient with COVID-19.

Liver injury is common in patients with COVID-19, but little is known about its clinical presentation and severity in the context of liver transplant. We describe a case of COVID-19 in a patient who underwent transplant 3 years ago for hepatocellular carcinoma. The patient came to clinic with symptoms of respiratory disease; pharyngeal swabs for severe acute respiratory syndrome coronavirus 2 were positive. His disease progressed rapidly from mild to critical illness and was complicated by several nosocomial infections and multiorgan failure. Despite multiple invasive procedures and rescue therapies, he died from the disease. The management of COVID-19 in the posttransplant setting presents complex challenges, emphasizing the importance of strict prevention strategies.

Development and validation of a molecular prognostic index of bladder cancer based on immunogenomic landscape analysis.

BACKGROUND: Bladder cancer (BCa) is one of the important tumors that have been proven to be treatable with immunotherapy. This study aims to identify and validate a molecular prognostic index of BCa based on immunogenomic landscape analysis. METHODS: The cancer genome atlas (TCGA) database and immunology database and analysis portal (ImmPort) database were used to identified differentially expressed immune-related genes (IRGs). Prognostic IRGs were screened and protein-protein interaction (PPI) network was constructed. Multivariate Cox analysis was performed to develop a molecular prognostic index of BCa. Internal and external validation were then performed in TCGA cohort and GEO cohort, respectively. Besides, we also explore the relationship between this index and clinical characteristics, immune cell infiltration and tumor microenvironment. RESULTS: A total of 61 prognostic IRGs were identified and a molecular prognostic index was developed. The top four hub genes included MMP9, IGF1, CXCL12 and PGF. The difference in overall survival between high-risk group and low-risk group was statistically significant. The area under curve of the receiver operating characteristic (ROC) curve was 0.757, suggesting the potential for this index. Besides, Internal validation using TCGA cohort and external validation using GEO cohort indicated that this index was of great performance in predicting outcome. T cells CD8, T cells CD4 memory activated, T cells follicular helper, macrophages M0, macrophages M2 and neutrophils were significantly associated with prognosis of BCa patients. Female, high grade, stage III&IV, N1-3 and T3-4 were associated significantly with higher risk score compared with male, low grade, stage I&II, N0 and T1-2, respectively. High risk score had a positive association with higher stromal score and ESTIMATE score while high risk score had a negative association with tumor purity. CONCLUSIONS: This study identified several prognostic immune-related genes of clinical value. Besides, we developed and validated a molecular index based on immunogenomic landscape analysis, which performed well in predicting prognosis of BCa. Further researches are needed to verify the effectiveness of this index and these vital genes.

Adverse events of video capsule endoscopy over the past two decades: a systematic review and proportion meta-analysis.

BACKGROUND: A full spectrum of video capsule endoscopy (VCE) adverse events over the past two decades has not been evaluated. We aimed to determine pooled rates, predictors and temporal-trend of VCE adverse events over the past two decades. METHODS: Systematic search of PubMed and EMBASE for English-language publications reporting VCE adverse events (January 1, 2000 to March 31, 2019). Data were extracted independently by two investigators. Pooled VCE adverse event rates were calculated using the random or fixed model as appropriate. Predictors and temporal-trend of each adverse event were performed by meta-regression analyses. RESULTS: In total, 402 studies were identified, including 108,079 VCE procedures. Rate of retention, swallow disorder, aspiration, technical failure, and procedural adverse events were 0.73% (95% confidence interval [CI] 0.59-0.89%), 0.75% (95% CI 0.43-1.13%), 0.00% (95% CI 0.00-0.00%), 0.94% (95% CI 0.65-1.28%), 0.67% (95% CI 0.32-1.10%), respectively; incomplete examination rate of esophagus, stomach, small bowel, and colon were 9.05%, 7.69%, 12.08%, 19.19%, respectively. Patency capsule reduced retention rate by 5.04%, whereas known inflammatory bowel disease increased retention rate by 4.29%. Elder was the risk and protective factor for small bowel incomplete examination (0.30%) and swallow disorder (- 0.72%), respectively. Rates of retention and small bowel incomplete examination significantly declined over time (P = .0006 and P < .0001).. CONCLUSIONS: VCE adverse event rates were generally low, and retention and small bowel incomplete examination rates declined over the past two decades. Patients with known inflammatory bowel disease or elder should be alerted to high risk of retention or small bowel incomplete examination (PROSPERO: CRD42019139595).

Novel 1H-pyrazolo[3,4-d]pyrimidin-6-amino derivatives as potent selective Janus kinase 3 (JAK3) inhibitors. Evaluation of their improved effect for the treatment of rheumatoid arthritis.

Selective JAK3 inhibitors have been shown to have a potential benefit in the treatment of autoimmune disorders. Here we report the identification of a series of pyrazolopyrimidine derivatives as potent JAK3 inhibitors that exploit a unique cysteine (Cys909) residue in JAK3. Most of these compounds (13k, 13n and 13 t), displayed stronger anti-JAK3 kinase activity and selectivity than tofacitinib. Furthermore, the most active inhibitor 13t (IC50 = 0.1 nM), also exhibited favourable selectivity for JAK3 in a panel of 9 kinases which contain the same cysteine. In a series of cytokinestimulated cellular analysis, compound 13 t, could potently block the JAK3-STAT signaling pathway. Further biological studies, including cellular antiproliferative activity assays and a rat adjuvant-induced arthritis model for in vivo evaluation, also indicated its efficacy and low toxicity in the treatment of rheumatoid arthritis. The results of these experimental explorations suggested that 13t is a promising lead compound for the development of selective JAK3 inhibitor with therapeutic potential in rheumatoid arthritis.

Nickel-refining fumes induce NLRP3 activation dependent on mitochondrial damage and ROS production in Beas-2B cells.

Nickel (Ni) is a silver-white transition metal that is widely used in the production field due to its unique physical and chemical properties. As a toxicant, long-term exposure to Ni can cause rhinitis, pneumonia and other respiratory inflammation. In the present study, we investigated the effect of particles extracted from Ni-refining fumes on cell viability, inflammation-related proteins and mitochondrial damage in human lung epithelial Beas-2B cells. The cells were exposed to Ni-refining fume particles for 24 h at concentrations of 0, 6.25, 12.50 and 25.00 µg/mL. The expression levels of the NACHT-LRR-PYD domains-containing protein 3 (NLRP3), caspase-1, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), interleukin (IL)-1ß and tumor necrosis factor (TNF)-α protein in Beas-2B cells exposed to Ni-refining fume particles increased significantly. Downregulation of NLRP3 expression by siRNA decreased the content of IL-1ß. During activation of NLRP3, the mitochondrial membrane potential (MMP) decreased, the opening rate of mitochondrial permeability transition pore (MPTP) increased, and the content of reactive oxygen species (ROS) increased. Using lipopolysaccharide (LPS) intervention as the positive control group, N-acetylcysteine (NAC, an effective ROS remover) acted as an inhibitor. After NAC reduced the level of ROS, activation of the NLRP3 inflammasome was significantly inhibited. Ni-refining fumes caused significant cytotoxicity, inflammation and mitochondrial damage in Beas-2B cells. The present study thus provides experimental support for the hypothesis that Ni-refining fumes cause inflammation by inducing ROS production in Beas-2B cells.