In vertebrates, IL-10 is an anti-inflammatory factor that serves as a key inhibitory role in a wide range of immune responses. IRAK1 (IL-1 receptor-associated kinase 1), a key molecule in the ...inflammatory signal of IL-1R/TLR, plays an important pivotal role in regulating the autoimmunity of body. STAT3 (Signal transducer and activator of transcription 3) activated by IRAK1 participates in inflammation, tumorigenesis, metabolic disorders and immune response. Under the stimulation of LPS, IRAK1 enters the nucleus to form a dimer with STAT3 and regulates the expression of IL-10. However, the relationship between fish IRAK1 and STAT3 has not been reported. To explain the anti-inflammation in fish, we amplified and identified the complete open reading frame of grass carp IRAK1 (CiIRAK1) and STAT3 (CiSTAT3) based on the existing sequences. The expression of CiIRAK1 and CiSTAT3 were up-regulated significantly under the stimulation of LPS. This result suggests that both CiIRAK1 and CiSTAT3 may be involved in LPS-induced TLR4 pathway. The subcellular localization experiment revealed that CiIRAK1 is distributed in cytoplasm and enters nucleus after LPS stimulation. CiSTAT3 is distributed in both cytoplasm and nucleus with or without LPS stimulation. Immunoprecipitation assay revealed that CiIRAK1 interacted with CiSTAT3 under LPS stimulation. However in absence of LPS stimulation, CiIRAK1 and CiSTAT3 cannot interact with each other. Subsequently, immunofluorescence colocalization experiment further proved the interaction of CiIRAK1 and CiSTAT3 in nucleus under LPS stimulation. The dual luciferase reporter assays indicated that the binding of CiIRAK1 and CiSTAT3 synergistically enhanced the activity of CiIL-10 promoter.
•Grass carp IRAK1 and STAT3 can respond to LPS stimulation.•LPS promotes grass carp IRAK1 nuclear translocation.•Grass carp IRAK1 interacts with STAT3 in nuclear.•Grass carp IRAK1 and STAT3 up-regulates synergistically the promoter activity of IL-10.
As a NAD+-dependent deacetylase, SIRT1 is widely involved in apoptosis and cellular inflammation via multiple pathways such as p53, NF-кB and STAT. More and more studies have shown that p53 is the ...first non-histone deacetylation target of SIRT1. SIRT1-p53 axis thus plays an important role in mammalian cells. IRF9 is an important member of interferon regulator factor family and performs an important role in innate immunity against foreign virus invasion. More importantly, human IRF9 can suppress the SIRT1-p53 axis. However, the functions and relationship between IRF9 and SIRT1-p53 axis are rarely studied in fish. To this end, we made a preliminary research on the functions of grass carp (Ctenopharyngodon idella) IRF9, SIRT1 and p53 in apoptosis and innate immunity. Firstly, we cloned and identified the ORF of SIRT1 (named CiSIRT1, MN125614) from C. idella and demonstrated that CiIRF9 promoted apoptosis, while CiSIRT1 inhibited apoptosis by flow cytometry and TUNEL experiments. Next, we found the interaction between CiSIRT1 and Cip53 in vivo by co-immunoprecipitation experiments. Moreover, the colocalization analysis also showed CiSIRT1 and Cip53 were mainly distributed in nucleus. Thirdly, we got a conclusion that CiIRF9 can repress the expression of CiSIRT1, implying that CiIRF9 regulates CiSIRT1-p53 axis. Finally, CiSIRT1 mRNA level was significantly up-regulated and the expression reached the highest level at 24 h post poly (I:C) stimulation in CIK cells. So, CiSIRT1 may exert an important function in innate immunity. Furthermore, we found CiSIRT1 down-regulated the expression of CiIFN1. In summary, CiIRF9 promotes apoptosis and innate immunity by inhibiting SIRT1-p53 axis. These findings will provide a new theoretical basis for the research on teleost innate immunity.
•CiIRF9 and CiSIRT1 perform the opposite effect on apoptosis.•The interaction of CiSIRT1 and Cip53 in nucleus.•CiIRF9 represses the transcription and expression of CiSIRT1.•CiSIRT1 inhibits the expression of IFN1.
The chitin‐based peritrophic matrix (PM) is a structure critical for both gut immunity and digestion in invertebrates. PM was traditionally considered lost in all vertebrates, but a PM‐like chitinous ...membrane (CM) has recently been discovered in fishes, which may increase the knowledge on vertebrate gut physiology and structural evolution. Here, we show that in zebrafish, the CM affects ingestion behavior, microbial homeostasis, epithelial renewal, digestion, growth, and longevity. Young mutant fish without CM appear healthy and are able to complete their life cycle normally, but with increasing age they develop gut inflammation, resulting in gut atrophy. Unlike mammals, zebrafish have no visible gel‐forming mucin layers to protect their gut epithelia, but at least in young fish, the CM is not a prerequisite for the antibacterial gut immunity. These findings provide new insights into the role of the CM in fish prosperity and its eventual loss in tetrapods. These findings may also help to improve fish health and conservation, as well as to advance the understanding of vertebrate gut physiology and human intestinal diseases.
Synopsis
The chitinous membrane (CM) is an essential gut structure in invertebrates that was considered lost in vertebrates, but was recently discovered in fish. This study shows that it has differential roles in zebrafish digestion and gut immunity.
The presence of the CM affects ingestive behavior, gut homeostasis, microbiota, digestion, growth, and longevity.
The CM is not a prerequisite for fish survival, reproduction, and gut immunity against bacteria.
CM absence results in age‐dependent gut inflammation and atrophy.
The CM has an important role in fish health, conservation, prosperity, and diversity.
The chitinous membrane (CM) is an essential gut structure in invertebrates that was considered lost in vertebrates, but was recently discovered in fish. This study shows that it has differential roles in zebrafish digestion and gut immunity.
In mammals, signal transducer and activator of transcription 6 (STAT6) is a broad-spectrum transcriptional regulator involved in cellular immune responses and apoptosis by regulating the ...immune-related genes and various functional genes. The structure, expression and tyrosine-based phosphorylation of STAT6 are conserved from fish to mammal. However, except the sporadic reports from zebra fish, the function of fish STAT6 has not been well reported. Here, we cloned and characterized the full length cDNA sequence of grass carp (Ctenopharyngodon idella) STAT6 (CiSTAT6). Meanwhile, the activation mechanism and the potential function of CiSTAT6 were studied. The full length cDNA of CiSTAT6 is 2747 bp with an ORF of 2313 bp encoding a polypeptide of 770 amino acids. Phylogenetic tree analysis revealed that CiSTAT6 shares the maximum homology with Cyprinus carpio STAT6. CiSTAT6 was significantly up-regulated and interacted with each other to form the homodimer after treatment with poly I:C. The transfected CiSTAT6 in fish cell lines can activate the promoter activities of CCL20 and Bcl-xl and increase their mRNA levels. In addition, we also found that CiSTAT6 can increase cell viability and inhibit cell apoptosis. Taken together, grass carp STAT6 plays an important part in innate immunity and anti-apoptosis.
•Grass carp STAT6 responds to poly I:C.•Grass carp STAT6 can form the homodimer under poly I:C processing.•Grass carp STAT6 up-regulates the transcriptional levels and expressions of CCL20 and Bcl-xl.•Overexpression of grass carp STAT6 enhances cell activity and inhibits apoptosis.
As a member of NDR protein kinase family and a novel protein kinase of Hippo signal pathway, Serine/threonine kinase 38 (STK38) plays a very significant role in the innate immune. In mammals, STK38 ...performs its function by combining with GSK3β. Nowadays, there are few reports of STK38 in fish. In order to explain the function of fish STK38 in the innate immunity, we cloned the ORF of grass carp (Ctenopharyngodon idella) STK38 (CiSTK38) and the related kinase GSK3β (CiGSK3β). Phylogenetic trees revealed that CiSTK38 and CiGSK3β evolved closer kinship with sinocyclocheilus grahami STK38 and siniperca chuatsi GSK3β respectively. CiSTK38 and CiGSK3β can respond to the intradermal injection of poly (I:C) in grass carp different tissues and the transfection of poly I:C in CIK cells. Subcellular localization revealed the CiGSK3β were broadly distributed through the cytoplasm, whereas CiSTK38 were observed both in cytoplasm and nucleus. However, when they were co-transferred into cells, the two proteins were found to aggregate in the nucleus. GST-pulldown and co-immunoprecipitation analysis revealed that CiSTK38 can physically interact with CiGSK3β. Phos-tag PAGE illustrated CiSTK38 can decrease the phosphorylation and auto-phosphorylation level of CiGSK3β at Ser9 and at Tyr216. To investigate the functional correlation between CiSTK38 and CiGSK3β, we overexpressed CiSTK38 and CiGSK3β in CIK cells and found that they can up-regulate the expression of IFN I. In short, we demonstrated that CiSTK38 can confer CiGSK3β kinase activity by reducing its phosphorylation level. Result from this study strongly suggested that the anti-viral immune effects elicited by poly (I:C) in part were mediated through activation of CiGSK3β. The findings provided scientific basis for the anti-viral immune mechanism of STK38 and GSK3β in fish.
•CiSTK38 and CiGSK3β respond to poly I:C stimulation.•CiSTK38 can physically bind to CiGSK3β in the absence of poly I: C.•CiSTK38 activates CiGSK3β via promoting its dephosphorylation.•CiSTK38 promotes the expression of IFN I via CiGSK3β.
In mammals, toll-like receptor 3 (TLR3) is capable of recognizing double-stranded RNA and then initiates transcription of IFN-β. TLR3 can activate the innate immune system by phosphorylating ...extracellular signal-regulated kinase 1 (ERK1) in the mitogen-activated protein kinase (MAPK) pathway. As a downstream signaling protein of ERK1, ribosomal protein S6 kinase alpha 3 (RSK2) is activated through the “classical” MAPK pathway. So RSK2 plays a critical role in response to innate immune system induced by TRL3. However, the innate immune mechanism of RSK2 remains indistinct in fish. In this study, we cloned and characterized a full length cDNA sequence of RSK2 from Ctenopharyngodon idella (named CiRSK2, MH844551). The full length cDNA of CiRSK2 is 3930 bp with a coding sequence of 2202 bp encoding a polypeptide of 734 amino acids. The expression of CiRSK2 was ubiquitous and significantly up-regulated under the stimulation of poly (I:C) in eight different tissues of C. idella and C. idella kidney cells (CIK). In addition, poly (I:C) stimulation also up-regulated the expression of CiERK1 mRNA in CIK cells and the phosphorylation of CiERK1. We also demonstrated that the activated CiERK1 interacted with CiRSK2 by CO-IP assay and immunofluorescence assay. To further investigate the relationship between CiRSK2 and CiERK1, we performed subcellular localization of CiRSK2 at different periods of CiERK1 stimulation. The result showed that CiERK1 can make CiRSK2 enter the nucleus. Subsequently, we found that CiRSK2 increased the transcriptional level of CiBCL-2 and protein level of CiBCL-2 significantly. Then cell apoptosis was inhibited to a certain extent. Overall, our results suggested that CiRSK2 plays important roles in fish innate immunity and is able to inhibit cell apoptosis by up-regulating CiBCL-2.
•CiERK1 and CiRSK2 responded to poly (I:C) stimulation.•Poly (I:C) promoted the phosphorylation of CiERK1.•Activated CiERK1 interacted with CiRSK2 and induced CiRSK2 to enter the nucleus.•CiRSK2 inhibited apoptosis by up-regulating CiBCL-2 in nucleus.
The Chinese government has announced ambitious carbon reduction goals to address climate change, however, there has been limited scientific attention to the achievement of deep decarbonization in ...regions with insufficient economic development. Moreover, the complex impacts of climate change mitigation on energy system, environment and economic development remain unclear in Northwest China. Here we construct a comprehensive evaluation model system to evaluate the effects of different climate mitigation pathways in Qinghai, Ningxia, Gansu and Xinjiang provinces. Results show that the four provinces need to vigorously increase the share of electricity that consumed in final energy to 53.1–60.0% and 52.9–62.0% for 2 °C and 1.5 °C target, respectively, and reduce total energy demand to 11.6–44.4 Mtoe and 8.2–34.1 Mtoe in 2050. Meanwhile, the CO2 emissions for their energy systems will reach peak by 2025 at lower values. Moreover, the synergies of CO2 reduction are most conducive to abating SO2 pollution and also contributing to decreasing PM2.5 concentrations. Additionally, the GDP losses in 2050 fluctuate from 5.0 to 21.7 billion USD in the 2 °C scenario to 11.5–52.7 billion USD in the 1.5 °C scenario. Our study provides practical guidance on achieving carbon reductions in less developed regions of China and lays foundations to promote decarbonization of energy systems in other provinces.
•Realizing climate goals requires low-carbon energy systems led by electricity.•Energy-related carbon emissions in Northwest China will peak by 2025.•More ambitious climate and clean air policies are needed for air quality improvement.•Economic loss shows an upward trend in the future under climate targets.
Aims. Basal insulin plus oral hypoglycemic agents (OHAs) has not been investigated for early intensive antihyperglycemic treatment in people with newly diagnosed type 2 diabetes. This study is aimed ...at comparing the short-term (over a period of 12 days) effects of basal insulin glargine plus OHAs and continuous subcutaneous insulin infusion (CSII) on glycemic control and beta-cell function in this setting. Methods. An open-label parallel-group study. Newly diagnosed hospitalized patients with type 2 diabetes and fasting plasma glucose (FPG) ≥11.1 mmol/L or glycated hemoglobin (HbA1c) ≥9% (75 mmol/mol) were randomized to CSII or insulin glargine in combination with metformin and gliclazide. The primary outcome measure was the mean amplitude of glycemic excursions (MAGE), and secondary endpoints included time to reach glycemic control target (FPG < 7 mmol/L and 2-hour postprandial plasma glucose < 10 mmol/L), markers of β-cell function, and hypoglycemia. Results. Subjects in the CSII (n=35) and basal insulin plus OHA (n=33) groups had a similar significant reduction from baseline to end of treatment in glycated albumin (−6.44 ± 3.23% and− 6.42 ± 3.56%, P=0.970). Groups A and B have comparable time to glycemic control (3.6 ± 1.2 days and 4.0 ± 1.4 days), MAGE (3.40 ± 1.40 mmol/L vs. 3.16 ± 1.38 mmol/L; p=0.484), and 24-hour mean blood glucose (7.49 ± 0.96 mmol/L vs. 7.02 ± 1.03 mmol/L). Changes in the C-peptide reactivity index, the secretory unit of islet in transplantation index, and insulin secretion-sensitivity index-2 indicated a greater β-cell function improvement with basal insulin plus OHAs versus CSII. Conclusions. Short-term insulin glargine plus OHAs may be an alternative to CSII for initial intensive therapy in people with newly diagnosed type 2 diabetes.
The molecular impact of diabetes mellitus on prostate gland has not been elucidated. In this study, we performed a whole-genome cDNA microarray analysis using a streptozotocin-induced diabetic rat ...model to identify the effects of diabetes on the gene expression profiles in prostate. Our study shows that diabetes causes changes in the expression of multiple genes, particularly those related to cell proliferation and differentiation, oxidative stress, DNA damage repair, cell cycle checkpoints, angiogenesis and apoptosis. These findings were confirmed by real-time polymerase chain reaction and immunohistochemical staining using rat and human prostate tissue. We also used a cell culture model (human normal prostatic RWPE-1 cell line) to study the direct effect of high glucose. We found that high glucose caused increased intracellular oxidative stress and DNA damage, as well as downregulation of anti-oxidative enzymes and DNA damage repair genes MRE11 and XRCC3. Our findings provide important insights into understanding the pathogenesis of the diabetes-induced changes in prostate as well as identifying potential therapeutic targets for future studies.
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