Whole-body deletion of LPS-induced TNF-α factor (LITAF) markedly improves experimental endotoxic shock and inflammatory arthritis

Characterization of differences in immune responses during bolus and continuous infusion endotoxin challenges using mathematical modelling

Endotoxin administration is commonly used to study the inflammatory response, and though traditionally given as a bolus injection, it can be administered as a continuous infusion over multiple hours. Several studies hypothesize that the latter better represents the prolonged and pronounced inflammation observed in conditions like sepsis. Yet very few experimental studies have administered endotoxin using both strategies, leaving significant gaps in determining the underlying mechanisms responsible for their differing immune responses. We used mathematical modelling to analyse cytokine data from two studies administering a 2 ng kg-1 dose of endotoxin, one as a bolus and the other as a continuous infusion over 4 h. Using our model, we simulated the dynamics of mean and subject-specific cytokine responses as well as the response to long-term endotoxin administration. Cytokine measurements revealed that the bolus injection led to significantly higher peaks for interleukin (IL)-8, while IL-10 reaches higher peaks during continuous administration. Moreover, the peak timing of all measured cytokines occurred later with continuous infusion. We identified three model parameters that significantly differed between the two administration methods. Monocyte activation of IL-10 was greater during the continuous infusion, while tumour necrosis factor α $ {\alpha} $ and IL-8 recovery rates were faster for the bolus injection. This suggests that a continuous infusion elicits a stronger, longer-lasting systemic reaction through increased stimulation of monocyte anti-inflammatory mediator production and decreased recovery of pro-inflammatory catalysts. Furthermore, the continuous infusion model exhibited prolonged inflammation with recurrent peaks resolving within 2 days during long-term (20-32 h) endotoxin administration.

Circ_0030042 inhibits trophoblast cell growth, invasion and epithelial-mesenchymal transition process in preeclampsia via miR-942-5p/LITAF

BACKGROUND

There is increasing evidence that circular RNAs (circRNAs) are involved in the processes of preeclampsia (PE). Circ_0030042 was found to be abnormally expressed in PE patients. However, the role and molecular mechanism of circ_0030042 in PE progression remains unclear.

METHODS

Quantitative real-time PCR was used for determining the expression of circ_0030042, microRNA (miR)- 942-5p and lipopolysaccharide induced TNF-α factor (LITAF). Trophoblast cell functions were determined using cell counting kit 8 assay, EdU assay, flow cytometry and transwell assay. The protein levels of epithelial-mesenchymal transition (EMT)-related markers and LITAF were examined using western blot analysis. Dual-luciferase reporter assay and RNA pull-down assay were used to verify RNA interaction.

RESULTS

Circ_0030042 had an elevated expression in PE patients, and its overexpression inhibited trophoblast cell growth, invasion, and EMT process. Circ_0030042 served as miR-942-5p sponge, and miR-942-5p inhibitor also reversed the regulation of circ_0030042 on trophoblast cell growth, invasion and EMT process. LITAF was targeted by miR-942-5p, and its knockdown abolished the inhibition effect of miR-942-5p on trophoblast cell growth, invasion, and EMT process. Also, circ_0030042 regulated LITAF expression via sponging miR-942-5p.

CONCLUSION

Circ_0030042 regulated trophoblast cell growth, invasion, and EMT process via the miR-942-5p/LITAF axis, providing a novel insight for PE treatment.

Growth and Hepatopancreas Health of Juvenile Chinese Mitten Crab (Eriocheir sinensis) Fed Different Levels of Black Soldier Fly (Hermetia illucens) Larvae Meal for Fish Meal Replacement

A 56-day feeding trial assessed the effects of black soldier fly larvae meal (BSFLM) on the growth performance and hepatopancreas health of juvenile Eriocheir sinensis. Six isoproteic and isolipidic diets with 0% (FM), 10% (BSFLM10), 20% (BSFLM20), 30% (BSFLM30), 40% (BSFLM40), or 50% (BSFLM50) replacement of fish meal by BSFLM were formulated. Compared to FM, replacing 10%-40% of fish meal with BSFLM did not significantly affect the weight gain rate (WGR) or specific growth rate (SGR), while BSFLM50 significantly decreased the WGR and SGR. Crabs fed BSFLM50 had significantly lower T-AOC activity than those fed other diets, and crabs fed BSFLM30, BSFLM40, or BSFLM50 had significantly lower activities of antioxidant enzymes (SOD and GSH-Px) in the hepatopancreas than those fed FM or BSFLM10. Compared to FM, BSFLM10, BSFLM20, and BSFLM30 did not affect the relative expression of genes related to the nonspecific immunity, while BSFLM40 and BSFLM50 upregulated the relative expression of these genes. Furthermore, histological analysis showed that the hepatopancreas was deformed in the BSFLM50 group, with widened lumens and loss of basal membrane integrity. In summary, BSFLM replacing 50% of fish meal reduced growth and structural damage to the hepatopancreas. An immune response was activated when the replacement level was over 30%. Therefore, the replacement level of dietary fish meal by BSFLM is recommended to be not more than 30% of the juvenile E. sinensis feed.

Spatiotemporal Immunomodulation and Biphasic Osteo-Vascular Aligned Electrospun Membrane for Diabetic Periosteum Regeneration

Under diabetic conditions, blood glucose fluctuations and exacerbated immunopathological inflammatory environments pose significant challenges to periosteal regenerative repair strategies. Responsive immune regulation in damaged tissues is critical for the immune microenvironment, osteogenesis, and angiogenesis stabilization. Considering the high-glucose microenvironment of such acute injury sites, a functional glucose-responsive immunomodulation-assisted periosteal regeneration composite material-PLA（Polylactic Acid）/COLI(Collagen I）/Lipo(Liposome）-APY29 (PCLA)-is constructed. Aside from stimulating osteogenic differentiation, owing to the presence of surface self-assembled type I collagen in the scaffolds, PCLA can directly respond to focal area high-glucose microenvironments. The PCLA scaffolds trigger the release of APY29-loaded liposomes, shifting the macrophages toward the M2 phenotype, inhibiting the release of inflammatory cytokines, improving the bone immune microenvironment, and promoting osteogenic differentiation and angiogenesis. Bioinformatics analyses show that PCLA enhances bone repair by inhibiting the inflammatory signal pathway regulating the polarization direction and promoting osteogenic and angiogenic gene expression. In the calvarial periosteal defect model of diabetic rats, PCLA scaffolds induce M2 macrophage polarization and improve the inflammatory microenvironment, significantly accelerating periosteal repair. Overall, the PCLA scaffold material regulates immunity in fluctuating high-glucose inflammatory microenvironments, achieves relatively stable and favorable osteogenic microenvironments, and facilitates the effective design of functionalized biomaterials for bone regeneration therapy in patients with diabetes.

The immuneoreaction and antioxidant status of Chinese mitten crab (Eriocheir sinensis) involve protein metabolism and the response of mTOR signaling pathway to dietary methionine levels

To study the effects of dietary methionine on growth performance, immunity, antioxidant capacity, protein metabolism, inflammatory response and apoptosis factors in Chinese mitten crabs (Eriocheir sinensis). Five diets with different methionine levels (0.63%, 0.85%, 1.06%, 1.25% and 1.47%) were fed to E. sinensis for 8 weeks. Results showed that in the 1.25% Met group, both growth performance and feed utilization were significantly increased. The crude protein content of crab muscle in the 1.06% and 1.25% Met groups was significantly higher than that in the control group. The immune and antioxidant enzyme activities, as well as gene expression levels of anti-lipopolysaccharide factor 1 (ALF1), Crustin-1, prophenoloxidase (proPO), cap 'n' collar isoform C (CncC) in 1.25% Met group were significantly higher than other groups. The activities of adenosine deaminase (ADA) and glutamate transaminase (GPT) in serum decreased first and then increased with the increase of methionine content, while the changes of ADA and GPT in hepatopancreas increased first and then decreased. 1.25% Met group exhibited significantly increased levels of GOT, GPT, and ADA compared to the control group. 1.25% Met diet group significantly up-regulated protein synthesis and anti-apoptotic factors, and significantly down-regulated inflammatory and pro-apoptotic factors in hepatopancreas. At 1.25% in the diet, methionine was found to boost E. sinensis growth, muscle protein deposition and immunity, as well as its antioxidant capacity. Combined with the above results, based on the expression of factors involved in the mammalian target of rapamycin (mTOR) signaling pathway and the mitogen-activated protein kinase (MAPK) signaling pathway, it is proved that methionine can not only promote protein metabolism, improve feed utilization, but also alleviate the inflammatory response and apoptosis caused by oxidative stress in the body.

Identification and clinical characterization of Charcot-Marie-Tooth disease type 1C patients with LITAF p.G112S mutation

BACKGROUND

Charcot-Marie-Tooth disease type 1C (CMT1C) is a rare subtype associated with LITAF gene mutations. Until now, only a few studies have reported the clinical features of CMT1C.

OBJECTIVE

This study was performed to find CMT1C patients with mutation of LITAF in a Korean CMT cohort and to characterize their clinical features.

METHODS

In total, 1,143 unrelated Korean families with CMT were enrolled in a cohort. We performed whole exome sequencing to identify LITAF mutations, and examined clinical phenotypes including electrophysiological and MRI features for the identified CMT1C patients.

RESULTS

We identified 10 CMT1C patients from three unrelated families with p.G112S mutation in LITAF. The frequency of CMT1C among CMT1 patients was 0.59%, which is similar to reports from Western populations. CMT1C patients showed milder symptoms than CMT1A patients. The mean CMT neuropathy score version 2 was 7.7, and the mean functional disability scale was 1.0. Electrophysiological findings showed a conduction block in 22% of affected individuals. Lower extremity MRIs showed that the superficial posterior and anterolateral compartments of the calf were predominantly affected.

CONCLUSIONS

We found a conduction block in Korean CMT1C patients with p.G112S mutation and first described the characteristic MRI findings of the lower extremities in patients with LITAF mutation. These findings will be helpful for genotype-phenotype correlation and will widen understanding about the clinical spectrum of CMT1C.

MicroRNA-27a-3p relieves inflammation and neurologic impairment after cerebral ischemia reperfusion via inhibiting LITAF and the TLR4/NF-κB pathway

Cerebral ischemia reperfusion (CIR) affects microRNA (miR) expression and causes substantial inflammation. Here, we investigated the influence and underlying mechanism of miR-27a-3p in rats with CIR. Firstly, Biliverdin treatment relieved cerebral infarction and decreased the levels of serum interleukin (IL)-1β, IL-6 and TNF-α. Through our previous study, we found key miR-27a-3p and its targeted gene LITAF might involve in the molecular mechanism of CIR. Then, the regulation between miR-27a-3p and LITAF was verified by the temporal miR-27a-3p and LITAF expression profiles and luciferase assay. Moreover, intracerebroventricular injection of the miR-27a-3p mimic significantly decreased the LITAF, TLR4, NF-κB and IL-6 levels at 24h post-surgery, whereas miR-27a-3p inhibitor reversed these effects. Furthermore, miR-27a-3p mimic could relieve cerebral infarct and neurologic deficit after CIR. In addition, injection of miR-27a-3p mimic decreased neuronal damage induced by CIR. Taken together, our results suggest that miR-27a-3p protect against CIR by relieving inflammation, neuronal damage and neurologic deficit via regulating LITAF and the TLR4/NF-κB pathway.

SIMPLE Is an Endosomal Regulator That Protects Against NAFLD by Targeting the Lysosomal Degradation of EGFR

BACKGROUND AND AIMS

NAFLD has become a tremendous burden for public health; however, there is no drug for NAFLD therapy at present. Impaired endo-lysosome-mediated protein degradation is observed in a variety of metabolic disorders, such as atherosclerosis, type 2 diabetes mellitus, and NAFLD. Small integral membrane protein of lysosome/late endosome (SIMPLE) is a regulator of endosome-to-lysosome trafficking and cell signaling, but the role that SIMPLE plays in NAFLD progression remains unknown. Here we investigated SIMPLE function in NAFLD development and sophisticated mechanism therein.

APPROACH AND RESULTS

This study found that in vitro knockdown of SIMPLE significantly aggravated lipid accumulation and inflammation in hepatocytes treated with metabolic stimulation. Consistently, in vivo experiments showed that liver-specific Simple-knockout (Simple-HKO) mice exhibited more severe high-fat diet (HFD)-induced, high-fat-high-cholesterol diet (HFHC)-induced, and methionine-choline-deficient diet (MCD)-induced steatosis, glucose intolerance, inflammation, and fibrosis than those fed with normal chow (NC) diet. Meanwhile, RNA-sequencing demonstrated the up-regulated signaling pathways and signature genes involved in lipid metabolism, inflammation, and fibrosis in Simple-HKO mice compared with control mice under metabolic stress. Mechanically, we found SIMPLE directly interact with epidermal growth factor receptor (EGFR). SIMPLE deficiency results in dysregulated degradation of EGFR, subsequently hyperactivated EGFR phosphorylation, thus exaggerating NAFLD development. Moreover, we demonstrated that using EGFR inhibitor or silencing EGFR expression could ameliorate lipid accumulation induced by the knockdown of SIMPLE.

CONCLUSIONS

SIMPLE ameliorated NASH by prompting EGFR degradation and can be a potential therapeutic candidate for NASH.

LITAF acts as a novel regulator for pathological cardiac hypertrophy

Pathological hypertrophy generally progresses to heart failure. Exploring effective and promising therapeutic targets might lead to progress in preventing its detrimental outcomes. Our current knowledge about lipopolysaccharide-induced tumor necrosis factor-α factor (LITAF) is mainly limited to regulate inflammation. However, the role of LITAF in other settings that are not that relevant to inflammation, such as cardiac remodeling and heart failure, remains largely unknown. In the present study, we found that the expression of LITAF decreased in hypertrophic hearts and cardiomyocytes. Meanwhile, LITAF protected cultured neonatal rat cardiomyocytes against phenylephrine-induced hypertrophy. Moreover, using LITAF knockout mice, we demonstrated that LITAF deficiency exacerbated cardiac hypertrophy and fibrosis compared with wild-type mice. Mechanistically, LITAF directly binds to the N-terminal of ASK1, thus disrupting the dimerization of ASK1 and blocking ASK1 activation, ultimately inhibiting ASK1-JNK/p38 signaling over-activation and protecting against cardiac hypertrophy. Furthermore, AAV9-mediated LITAF overexpression attenuated cardiac hypertrophy in vivo. Conclusions: Our findings uncover the novel role of LITAF as a negative regulator of cardiac remodeling. Targeting the interaction between LITAF and ASK1 could be a promising therapeutic strategy for pathological cardiac remodeling.

The endosomal trafficking regulator LITAF controls the cardiac Nav1.5 channel via the ubiquitin ligase NEDD4-2

The QT interval is a recording of cardiac electrical activity. Previous genome-wide association studies identified genetic variants that modify the QT interval upstream of LITAF (lipopolysaccharide-induced tumor necrosis factor-α factor), a protein encoding a regulator of endosomal trafficking. However, it was not clear how LITAF might impact cardiac excitation. We investigated the effect of LITAF on the voltage-gated sodium channel Nav1.5, which is critical for cardiac depolarization. We show that overexpressed LITAF resulted in a significant increase in the density of Nav1.5-generated voltage-gated sodium current INa and Nav1.5 surface protein levels in rabbit cardiomyocytes and in HEK cells stably expressing Nav1.5. Proximity ligation assays showed co-localization of endogenous LITAF and Nav1.5 in cardiomyocytes, whereas co-immunoprecipitations confirmed they are in the same complex when overexpressed in HEK cells. In vitro data suggest that LITAF interacts with the ubiquitin ligase NEDD4-2, a regulator of Nav1.5. LITAF overexpression down-regulated NEDD4-2 in cardiomyocytes and HEK cells. In HEK cells, LITAF increased ubiquitination and proteasomal degradation of co-expressed NEDD4-2 and significantly blunted the negative effect of NEDD4-2 on INa We conclude that LITAF controls cardiac excitability by promoting degradation of NEDD4-2, which is essential for removal of surface Nav1.5. LITAF-knockout zebrafish showed increased variation in and a nonsignificant 15% prolongation of action potential duration. Computer simulations using a rabbit-cardiomyocyte model demonstrated that changes in Ca2+ and Na+ homeostasis are responsible for the surprisingly modest action potential duration shortening. These computational data thus corroborate findings from several genome-wide association studies that associated LITAF with QT interval variation.

Effects of dietary T-2 toxin on gut health and gut microbiota composition of the juvenile Chinese mitten crab (Eriocheir sinensis)

The current study aims to investigate the effects of dietary T-2 toxin on the intestinal health and microflora in the juvenile Chinese mitten crab (Eriocheir sinensis) with an initial weight 2.00 ± 0.05 g. Juvenile crabs were fed with experimental diets supplemented with T-2 toxin at 0 (control), 0.6 (T1 group), 2.5 (T2 group) and 5.0 (T3 group) mg/kg diet for 8 weeks. Dietary T-2 toxin increased the malondialdehyde (MDA) content and the expression of Kelch-like ECH-associated protein 1 (keap1) gene while the expression of cap 'n' collar isoform C (CncC) decreased in the intestine. The activities of glutathione peroxidase (GSH-Px) and total anti-oxidation capacity (T-AOC) in the intestine increased only in the lower dose of dietary T-2. Dietary T-2 toxin significantly increased the mRNA expression of caspase-3, caspase-8, Bax and mitogen-activated protein kinase (MAPK) genes and the ratio of Bax to Bcl-2 accompanied with a reduction of Bcl-2 expression. Furthermore, T-2 toxin decreased the mRNA levels of antimicrobial peptides (AMPs), peritrophic membrane (PM1 and PM2) and immune regulated nuclear transcription factors (Toll-like receptor: TLR, myeloid differentiation primary response gene 88: Myd88, relish and lipopolysaccharide-induced TNF-α factor: LITAF). The richness and diversity of the gut microbiota were also affected by dietary T-2 toxin in T3 group. The similar dominant phyla in the intestine of the Chinese mitten crab in the control and T3 groups were found including Bacteroidetes, Firmicutes, Tenericutes and Proteobacteria. Moreover, the inclusion of dietary T-2 toxin of 4.6 mg/kg significantly decreased the richness of Bacteroidetes and increased the richness of Firmicutes, Tenericutes and Proteobacteria in the intestine. At the genus level, Dysgonomonas and Romboutsia were more abundant in T3 group than those in the control. However, the abundances of Candidatus Bacilloplasma, Chryseobacterium and Streptococcus in T3 group were lower than those in the control. This study indicates that T-2 toxin could cause oxidative damage and immunosuppression, increase apoptosis and disturb composition of microbiota in the intestine of Chinese mitten crab.

Baicalin alleviates lipopolysaccharide-induced neuroglial activation and inflammatory factors activation in hippocampus of adult mice

Baicalin is a natural flavonoid that exerts a variety of pharmaceutical effects such as anti-inflammatory and antioxidant. Lipopolysaccharide (LPS) is an endotoxin that releases inflammatory cytokines and induces inflammatory response. This study was investigated the anti-inflammatory mechanism of baicalin against LPS-induced inflammatory response in the hippocampus. Adult mice were randomly grouped into control, LPS-treated, and LPS and baicalin co-treated animals. LPS (250 μg/kg/day) and baicalin (10 mg/kg/day) were administered intraperitoneally for 7 consecutive days. We measured neuroglia cells activation and inflammatory factors activation using Western blot analysis and immunofluorescence staining techniques. Ionized calcium binding adaptor molecule-1 (Iba-1) and glial fibrillary acidic protein (GFAP) are widely used as microglia and astrocyte markers, respectively. LPS treatment increased Iba-1 and GFAP expression, while baicalin co-treatment attenuated this overexpression. Nuclear factor-kappa B (NF-κB) is a key mediator of inflammation. Baicalin co-treatment alleviated LPS-induced increase of NF-κB in the hippocampus. In addition, LPS treatment upregulated pro-inflammatory cytokines including interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). However, baicalin co-treatment prevented LPS-induced increases of IL-1β and TNF-α in the hippocampus. Results from the present study showed that baicalin suppresses LPS-induced neuroinflammation by regulating microglia and astrocyte activation and modulating inflammatory factors in the hippocampus. Thus, these results demonstrate that baicalin has neuroprotective effect by alleviates microglia and astrocyte activation and modulates inflammatory response by suppressing NF-κB expression in hippocampus with neuroinflammation caused by LPS.

Effects of graded levels of starch on the non-specific immune responses, antioxidant capacities and intestinal health in Chinese mitten crab, Eriocheir inensis

A 9-week feeding trial was conducted to investigate the effects of graded levels of dietary starch (12%, 17%, 22%, 27% and 32%) on growth, non-specific immune responses, antioxidant capacities, immunity genes expression levels and pathogen resistance in Chinese mitten crab, Eriocheir inensis (initial body weight: 10.5 ± 0.5 g). Results showed that the highest weight gain rate of crabs was obtained in group containing 22% dietary starch. The highest activity of acid phosphatase, phenoloxidase and lysozyme in blood was found in crabs fed with 22-27% dietary starch. Additionally, 17%-27% dietary starch significantly increased the activities of superoxide dismutase and glutathione peroxidase, reduced malondinaldehyde content and then increased the total antioxidant capacities in hepatopancreas of crabs. The highest activity of alanine aminotransferase and aspartate aminotransferase was found in crabs fed with 32% dietary starch, indicating that excess starch had a negative effect on the liver function of crabs. With the dietary starch level increased, the transcription factors gene expression of the pro-inflammatory factors were significantly up-regulated, and the highest ILF2, IL-16, Relish and ADAM10 was found in crabs fed with dietary 32% starch, which may potentially promote the inflammatory response in intestines. Moreover, with the dietary starch increased, the activity of phenoloxidase and lysozyme, as well as the gene expression of crustin, were all increased in crabs after challenge against Citrobacter freundii, which demonstrated that additional dietary starch could provide immune-protection and help crabs improve their resistance against pathogens. In conclusion, these results suggest that adequate dietary starch can increase growth, enhance innate immune responses and promote disease resistance, reduce oxidative stress and inflammatory response in E. inensis. Taken together, 22-27% dietary starch (25.9-30.8% dietary carbohydrate) was suggested as a digestible energy source in crabs feed.

Sequential CRISPR-Based Screens Identify LITAF and CDIP1 as the Bacillus cereus Hemolysin BL Toxin Host Receptors

Bacteria and their toxins are associated with significant human morbidity and mortality. While a few bacterial toxins are well characterized, the mechanism of action for most toxins has not been elucidated, thereby limiting therapeutic advances. One such example is the highly potent pore-forming toxin, hemolysin BL (HBL), produced by the gram-positive pathogen Bacillus cereus. However, how HBL exerts its effects and whether it requires any host factors is unknown. Here, we describe an unbiased genome-wide CRISPR-Cas9 knockout screen that identified LPS-induced TNF-α factor (LITAF) as the HBL receptor. Using LITAF-deficient cells, a second, subsequent whole-genome CRISPR-Cas9 screen identified the LITAF-like protein CDIP1 as a second, alternative receptor. We generated LITAF-deficient mice, which exhibit marked resistance to lethal HBL challenges. This work outlines and validates an approach to use iterative genome-wide CRISPR-Cas9 screens to identify the complement of host factors exploited by bacterial toxins to exert their myriad biological effects.

LITAF (Lipopolysaccharide-Induced Tumor Necrosis Factor) Regulates Cardiac L-Type Calcium Channels by Modulating NEDD (Neural Precursor Cell Expressed Developmentally Downregulated Protein) 4-1 Ubiquitin Ligase

BACKGROUND

The turnover of cardiac ion channels underlying action potential duration is regulated by ubiquitination. Genome-wide association studies of QT interval identified several single-nucleotide polymorphisms located in or near genes involved in protein ubiquitination. A genetic variant upstream of LITAF (lipopolysaccharide-induced tumor necrosis factor) gene prompted us to determine its role in modulating cardiac excitation.

METHODS

Optical mapping was performed in zebrafish hearts to determine Ca2+ transients. Live-cell confocal calcium imaging was performed on adult rabbit cardiomyocytes to determine intracellular Ca2+handling. L-type calcium channel (LTCC) current (ICa,L) was measured using whole-cell recording. To study the effect of LITAF on Cav1.2 (L-type voltage-gated calcium channel 1.2) channel expression, surface biotinylation, and Westerns were performed. LITAF interactions were studied using coimmunoprecipitation and in situ proximity ligation assay.

RESULTS

LITAF knockdown in zebrafish resulted in a robust increase in calcium transients. Overexpressed LITAF in 3-week-old rabbit cardiomyocytes resulted in a decrease in ICa,L and Cavα1c abundance, whereas LITAF knockdown increased ICa,L and Cavα1c protein. LITAF-overexpressing decreases calcium transients in adult rabbit cardiomyocytes, which was associated with lower Cavα1c levels. In tsA201 cells, overexpressed LITAF downregulated total and surface pools of Cavα1c via increased Cavα1c ubiquitination and its subsequent lysosomal degradation. We observed colocalization between LITAF and LTCC in tsA201 and cardiomyocytes. In tsA201, NEDD (neural precursor cell expressed developmentally downregulated protein) 4-1, but not its catalytically inactive form NEDD4-1-C867A, increased Cavα1c ubiquitination. Cavα1c ubiquitination was further increased by coexpressed LITAF and NEDD4-1 but not NEDD4-1-C867A. NEDD4-1 knockdown abolished the negative effect of LITAF on ICa,L and Cavα1c levels in 3-week-old rabbit cardiomyocytes. Computer simulations demonstrated that a decrease of ICa,L current associated with LITAF overexpression simultaneously shortened action potential duration and decreased calcium transients in rabbit cardiomyocytes.

CONCLUSIONS

LITAF acts as an adaptor protein promoting NEDD4-1-mediated ubiquitination and subsequent degradation of LTCC, thereby controlling LTCC membrane levels and function and thus cardiac excitation.

LITAF Enhances Radiosensitivity of Human Glioma Cells via the FoxO1 Pathway

Lipopolysaccharide-induced tumor necrosis factor alpha factor (LITAF), also called p53-induced gene 7 (PIG7), was identified as a transcription factor that activates transcription of proinflammatory cytokines in macrophages in response to lipopolysaccharide (LPS). Previous studies have identified LITAF as a potential tumor suppressor in several neoplasms, including prostate cancer, B-NHL, acute myeloid leukemia, and pancreatic cancer. However, the expression and function of LITAF in human glioma remain unexplained. The present study aimed to analyze the regulation of LITAF in gliomas. Data from The Cancer Genome Atlas (TCGA) database revealed that LITAF mRNA expression in glioma tissues was higher than that in normal brain tissues, and lower LITAF expression in gliomas showed a good prognosis in patients who received radiotherapy, by Kaplan-Meier analysis. In our collected specimens, however, LITAF showed low expression in glioma tissues compared to that in the normal brain tissue. Proliferation and apoptosis of glioma cells were not affected by knockdown or overexpression of LITAF in glioma U251, U373, and U87 cells, but LITAF was able to enhance the radiosensitivity of glioma cells. Furthermore, we found that LITAF enhanced radiosensitivity via FoxO1 and its specific downstream targets BIM, TRAIL, and FASLG. Taken together, our present results demonstrate that LITAF expression is decreased in glioma tissues and might enhance radiosensitivity of glioma cells via upregulation of the FoxO1 pathway.

Astaxanthin prevents against lipopolysaccharide-induced acute lung injury and sepsis via inhibiting activation of MAPK/NF-κB

BACKGROUND

Endotoxin-induced acute inflammatory diseases such as sepsis, mediated by excessive production of various pro-inflammatory cytokines remain the leading cause of mortality in critically ill patients. Lipopolysaccharide (LPS), the characteristic endotoxin found in the outer membrane of Gram-negative bacteria, can induce the innate immunity system and through Mitogen activated protein kinase (MAPK) and Nuclear Factor-κB (NF-κB), increase the production of inflammatory mediators. Astaxanthin (ASX), a xanthophyll carotenoid, exerts beneficial effects against oxidation, inflammation, and cancer. But poor evidence has been reported that whether it has protective effects on LPS-induced injury. This study aims to investigate the effects of ASX on LPS-induced sepsis and acute lung injury and to demonstrate its mechanisms.

METHODS

Mouse prime macrophage (MPM) challenged with LPS were used for in vitro pharmacological activity and mechanistic studies. Inflammatory facors (tumor necrosis factor-alpha and interleukin-6 levels) in MPM were determined. The mouse models of LPS-induced sepsis and acute lung injury administrated with or without the compound were used for in vivo studies.

RESULTS

Pre-treatment of MPM with ASX inhibited MAPK/NF-κB signaling pathway, and attenuated LPS-increased inflammatory factors in vitro. In animal models of LPS-induced sepsis and acute lung injury, administration of ASX significantly improved survival and protected lung injury. Subsequently, ASX was shown to suppress LPS-induced inflammatory factors increase, MAPK phosphorylation, and NF-κB activation in vivo.

CONCLUSIONS

ASX exerts impressively protective effects on LPS-induced injury in vitro and in vivo. Taken together, it might be used as a potential candidate for clinical sepsis.

Ghrelin protects against contact dermatitis and psoriasiform skin inflammation by antagonizing TNF-α/NF-κB signaling pathways

Contact dermatitis and psoriasis are skin disorders caused by immune dysregulation, yet much remains unknown about their underlying mechanisms. Ghrelin, a recently discovered novel peptide and potential endogenous anti-inflammatory factor expressed in the epidermis, is involved in skin repair and disease. In this study, we investigated the expression pattern and therapeutic effect of ghrelin in both contact dermatitis and psoriasis mouse models induced by oxazolone (OXA) and imiquimod (IMQ), respectively, and in TNF-α-stimulated RAW264.7 macrophages, NHEKs and skin fibroblasts. Ghrelin expression was reduced in both the OXA-induced contact dermatitis and IMQ-induced psoriasis mouse models. Furthermore, treatment with ghrelin attenuated skin inflammation in both the contact dermatitis and psoriasis mouse models. Mice administered PBS after OXA- or IMQ-induced model generation exhibited typical skin inflammation, whereas ghrelin treatment in these mouse models substantially decreased the dermatitis phenotype. In addition, exogenous ghrelin attenuated the inflammatory reaction induced by TNF-α in RAW264.7 cells. Moreover, ghrelin administration limited activation of NF-κB signaling. In summary, ghrelin may represent a potential molecular target for the prevention and treatment of inflammatory skin diseases, including contact dermatitis and psoriasis.

A potential regulatory network among WDR86-AS1, miR-10b-3p, and LITAF is possibly involved in preeclampsia pathogenesis

Preeclampsia (PE), a pregnancy-specific disorder, is a leading cause of perinatal maternal and fetal mortality and morbidity. Impaired migration and invasion of trophoblastic cells and an imbalanced systemic maternal inflammatory response have been proposed as possible causes of pathogenesis of PE. Comparative analysis of PE-affected placentas and healthy placentas has uncovered differentially expressed long noncoding RNAs, microRNAs, and mRNAs. This study was conducted to investigate the effect of a regulatory network among these RNAs on PE pathogenesis. Long noncoding RNA WDR86-AS1, microRNA miR-10b-3p, and mRNA of protein LITAF were identified by screening of genes in existing databases with aberrant expression in PE-affected placentas and potential mutual interactions as revealed by TargetScan, miRanda, and PicTar analyses. This study identified their expression in PE-affected and healthy placentas by RT-PCR. An in vitro experiment was performed on human trophoblast HTR-8/SVneo cells cultured under normoxic or hypoxic conditions. MiR-10b-3p targets were identified in luciferase reporter assays and RNA pull-down assays. The mouse model of PE was set up using a soluble form of FLT-1 for in vivo testing. Lower levels of miR-10b-3p but higher expression of WDR86-AS1 and LITAF were observed in PE-affected placentas and trophoblast cells under hypoxia. WDR86-AS1 and LITAF mRNA were confirmed as targets of miR-10b-3p. WDR86-AS1 downregulated miR-10b-3p but promoted LITAF expression. Microarray analyses revealed that LITAF controlled the inflammatory responses and migration and proliferation of HTR-8/SVneo cells under hypoxia. Indeed, knockdown of WDR86-AS1 and LITAF or overexpression of miR-10b-3p attenuated the hypoxia-induced inhibition of cellular viability, migration, and invasion. Moreover, miR-10b-3p overexpression attenuated the pathological symptoms caused by soluble FLT-1 in vivo. In summary, the WDR86-AS1/miR-10b-3p/LITAF network is probably involved in PE pathogenesis.

Reduction of Articular and Systemic Inflammation by Kava-241 in a Porphyromonas gingivalis-Induced Arthritis Murine Model

Rheumatoid arthritis (RA) is an inflammatory disease that has been linked to several risk factors, including periodontitis. Identification of new anti-inflammatory compounds to treat arthritis is needed. We had previously demonstrated the beneficial effect of Kava-241, a kavain-derived compound, in the management of Porphyromonas gingivalis-induced periodontitis. The present study evaluated systemic and articular effects of Kava-241 in an infective arthritis murine model triggered by P. gingivalis bacterial inoculation and primed with a collagen antibody cocktail (CIA) to induce joint inflammation and tissular destruction. Clinical inflammation score and radiological analyses of the paws were performed continuously, while histological assessment was obtained at sacrifice. Mice exposed to P. gingivalis and a CIA cocktail and treated concomitantly with Kava-241 exhibited a reduced clinical inflammatory score and a decreased number of inflammatory cells and osteoclasts within joint. Kava-241 treatment also decreased significantly tumor necrosis factor alpha (TNF-α) in serum from mice injected with a Toll-like receptor 2 or 4 (TLR-2/4) ligand, P. gingivalis-lipopolysaccharide (LPS). Finally, bone marrow-derived macrophages infected with P. gingivalis and exposed to Kava-241 displayed reduced TLR-2/4, reduced mitogen-activated protein kinase (MAPK)-related signal elements, and reduced LPS-induced TNF-α factor (LITAF), all explaining the observed reduction of TNF-α secretion. Taken together, these results emphasized the novel properties of Kava-241 in the management of inflammatory conditions, especially TNF-α-related diseases such as infective RA.

Design, synthesis, and structure-activity relationships of 2-benzylidene-1-indanone derivatives as anti-inflammatory agents for treatment of acute lung injury

Purpose

The purpose of this study was to design and synthesize novel 2-benzylidene-1-indanone derivatives for treatment of acute lung injury.

Methods

A series of 39 novel 2-benzylidene-indanone structural derivatives were synthesized and evaluated for anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated murine primary macrophages.

Results

Most of the obtained compounds effectively inhibited the LPS-induced expression of IL-6 and TNF-α. The most active compound, 8f, was found to significantly reduce LPS-induced pulmonary inflammation, as reflected by reductions in the concentration of total protein, inflammatory cell count, as well as the lung wet/dry ratio in bronchoalveolar lavage (BAL) fluid. Furthermore, 8f effectively inhibited mRNA expression of several inflammatory cytokines after LPS challenge in vitro and in vivo. Administration of 8f also blocked LPS-induced activation of the proinflammatory NF-κB/MAPK signaling pathway.

Conclusion

The simple synthetic preparation and biological properties of these derivatives make these 2-benzylidene-indanone scaffolds promising new entities for the development of anti-inflammatory therapeutics for the treatment of acute lung injury.

Glucocorticoids, genes and brain function

The identification of key genes in transcriptomic data constitutes a huge challenge. Our review of microarray reports revealed 88 genes whose transcription is consistently regulated by glucocorticoids (GCs), such as cortisol, corticosterone and dexamethasone, in the brain. Replicable transcriptomic data were combined with biochemical and physiological data to create an integrated view of the effects induced by GCs. The most frequently reported genes were Errfi1 and Ddit4. Their up-regulation was associated with the altered transcription of genes regulating growth factor and mTORC1 signaling (Gab1, Tsc22d3, Dusp1, Ndrg2, Ppp5c and Sesn1) and progression of the cell cycle (Ccnd1, Cdkn1a and Cables1). The GC-induced reprogramming of cell function involves changes in the mRNA level of genes responsible for the regulation of transcription (Klf9, Bcl6, Klf15, Tle3, Cxxc5, Litaf, Tle4, Jun, Sox4, Sox2, Sox9, Irf1, Sall2, Nfkbia and Id1) and the selective degradation of mRNA (Tob2). Other genes are involved in the regulation of metabolism (Gpd1, Aldoc and Pdk4), actin cytoskeleton (Myh2, Nedd9, Mical2, Rhou, Arl4d, Osbpl3, Arhgef3, Sdc4, Rdx, Wipf3, Chst1 and Hepacam), autophagy (Eva1a and Plekhf1), vesicular transport (Rhob, Ehd3, Vps37b and Scamp2), gap junctions (Gjb6), immune response (Tiparp, Mertk, Lyve1 and Il6r), signaling mediated by thyroid hormones (Thra and Sult1a1), calcium (Calm2), adrenaline/noradrenaline (Adcy9 and Adra1d), neuropeptide Y (Npy1r) and histamine (Hdc). GCs also affected genes involved in the synthesis of polyamines (Azin1) and taurine (Cdo1). The actions of GCs are restrained by feedback mechanisms depending on the transcription of Sgk1, Fkbp5 and Nr3c1. A side effect induced by GCs is increased production of reactive oxygen species. Available data show that the brain's response to GCs is part of an emergency mode characterized by inactivation of non-core activities, restrained inflammation, restriction of investments (growth), improved efficiency of energy production and the removal of unnecessary or malfunctioning cellular components to conserve energy and maintain nutrient supply during the stress response.

Glycogen synthase kinase-3 (GSK3) regulates TNF production and haemocyte phagocytosis in the immune response of Chinese mitten crab Eriocheir sinensis

Glycogen synthase kinase-3 (GSK3) is a serine/threonine protein kinase firstly identified as a regulator of glycogen synthesis. Recently, it has been proved to be a key regulator of the immune reaction. In the present study, a GSK3 homolog gene (designated as EsGSK3) was cloned from Chinese mitten crab, Eriocheir sinensis. The open reading frame (ORF) was 1824 bp, which encoded a predicted polypeptide of 607 amino acids. There was a conserved Serine/Threonine Kinase domain and a DNA binding domain found in EsGSK3. Phylogenetic analysis showed that EsGSK3 was firstly clustered with GSK3-β from oriental river prawn Macrobrachium nipponense in the invertebrate branch, while GSK3s from vertebrates formed the other distinct branch. EsGSK3 mRNA transcripts could be detected in all tested tissues of the crab including haepatopancreas, eyestalk, muscle, gonad, haemocytes and haematopoietic tissue with the highest expression level in haepatopancreas. And EsGSK3 protein was mostly detected in the cytoplasm of haemocyte by immunofluorescence analysis. The expression levels of EsGSK3 mRNA increased significantly at 6 h after Aeromonas hydrophila challenge (p < 0.05) in comparison with control group, and then gradually decreased to the initial level at 48 h (p > 0.05). The mRNA expression of lipopolysaccharide-induced tumor necrosis factor (TNF)-α factor (EsLITAF) was also induced by A. hydrophila challenge. However, the mRNA expression of EsLITAF and TNF-α production was significantly suppressed after EsGSK3 was blocked in vivo with specific inhibitor lithium, while the phagocytosis of crab haemocytes was significantly promoted. These results collectively demonstrated that EsGSK3 could regulate the innate immune responses of E. sinensis by promoting TNF-α production and inhibiting haemocyte phagocytosis.

Identification and Characterization of Lipopolysaccharide Induced TNFα Factor from Blunt Snout Bream, Megalobrama amblycephala

Lipopolysaccharide induced TNFα factor (LITAF) is an important transcription factor responsible for regulation of tumor necrosis factor α. In this study, a novel litaf gene (designated as Malitaf) was identified and characterized from blunt snout bream, Megalobrama amblycephala. The full-length cDNA of Malitaf was of 956 bp, encoding a polypeptide of 161 amino acids with high similarity to other known LITAFs. A phylogenetic tree also showed that Malitaf significantly clustered with those of other teleost, indicating that Malitaf was a new member of fish LITAF family. The putative maLITAF protein possessed a highly conserved LITAF domain with two CXXC motifs. The mRNA transcripts of Malitaf were detected in all examined tissues of healthy M. amblycephala, including kidney, head kidney, muscle, liver, spleen, gill, and heart, and with the highest expression in immune organs: spleen and head kidney. The expression level of Malitaf in spleen was rapidly up-regulated and peaked (1.29-fold, p < 0.05) at 2 h after lipopolysaccharide (LPS) stimulation. Followed the stimulation of Malitaf, Matnfα transcriptional level was also transiently induced to a high level (51.74-fold, p < 0.001) at 4 h after LPS stimulation. Taken together, we have identified a putative fish LITAF ortholog, which was a constitutive and inducible immune response gene involved in M. amblycephala innate immunity during the course of a pathogenic infection.

Plasma Intermedin Level Indicates Severity and Treatment Efficacy of Septic Shock in Sprague-Dawley (SD) Rats

BACKGROUND The aim of this study was to investigate the value of plasma intermedin (IMD) in assessing severity and treatment efficacy of septic shock. MATERIAL AND METHODS Healthy male Sprague-Dawley (SD) rats were chosen and divided into a normal control group (n=15) and a shock model group (n=27) that received intravenous injection of lipopolysaccharide (LPS). Then, 3 specimens were taken from each group. The shock model group rats were divided into an LPS group and a treatment group with 12 rats each. The treatment group received intravenous injection of compound sodium lactate solution. Plasma IMD and IMD1-47 mRNA expressions were compared and analyzed. RESULTS Mean arterial pressure (MAP) was lower while white blood cell count and TNF-α were higher in the shock model group than in the normal control group (P<0.05). After 10 h and 20 h, the treatment group had lower plasma IMD and IMD1-47 mRNA expressions compared with the LPS group (P<0.05). Plasma IMD and IMD1-47 mRNA expressions in the LPS group after 20 h were significantly higher than after 10 h (P<0.05). IMD was positively correlated with interleukins (IL-3, IL-6, and IL-8), white blood cell count, and body temperature (all P<0.05), but were negatively correlated with systolic pressure (r=-0.8474, P=0.0040). CONCLUSIONS Plasma IMD level can effectively reflect the severity of septic shock and can be used as an important indicator of septic shock treatment effectiveness.

The activation of EGFR promotes myocardial tumor necrosis factor-α production and cardiac failure in endotoxemia

To study the effect of EGFR activation on the generation of TNF-α and the occurrence of cardiac dysfuncetion during sepsis, PD168393 and erlotinib (both are EGFR inhibitors) were applied to decreased the production of TNF-α and phosphrylation of ERK1/2 and p38 induced by LPS in cardiomyocytes. These results were further proved by specifically knocked down the expression of EGFR in vitro. Both TAPI-1, a TNF-α converting enzyme (TACE) inhibitor, and TGF-α neutralizing antibody could inhibit the activation of EGFR and the generation of TNF-α mRNA after LPS treatment. The increase of TGF-α in response to LPS could also be suppressed by TAPI-1. On the other hand, exogenous TGF-α increased the expression of TNF-α mRNA and partially reversed the inhibitory effect of TAPI-1 on expression of TNF-α mRNA in response to LPS indicating that the transactivation of EGFR by LPS in cardiomyocytes needs the help of TACE and TGF-α. In endotoxemic mice, inhibition the activation of EGFR not only decreased TNF-α production in the myocardium but also improved left ventricular pump function and ameliorated cardiac dysfunction and ultimately improved survival rate. All these results provided a new insight of how EGFR regulation the production of TNF-α in cardiomyocytes and a potential new target for the treatment of cardiac dysfunction in sepsis.

LPS-induced TNF-α factor mediates pro-inflammatory and pro-fibrogenic pattern in non-alcoholic fatty liver disease

Lipopolysaccharide (LPS) is currently considered one of the major players in non-alcoholic fatty liver disease (NAFLD) pathogenesis and progression. Here, we aim to investigate the possible role of LPS-induced TNF-α factor (LITAF) in inducing a pro-inflammatory and pro-fibrogenic phenotype of non-alcoholic steatohepatitis (NASH).We found that children with NAFLD displayed, in different liver-resident cells, an increased expression of LITAF which correlated with histological traits of hepatic inflammation and fibrosis. Total and nuclear LITAF expression increased in mouse and human hepatic stellate cells (HSCs). Moreover, LPS induced LITAF-dependent transcription of IL-1β, IL-6 and TNF-α in the clonal myofibroblastic HSC LX-2 cell line, and this effect was hampered by LITAF silencing. We showed, for the first time in HSCs, that LITAF recruitment to these cytokine promoters is LPS dependent. However, preventing LITAF nuclear translocation by p38MAPK inhibitor, the expression of IL-6 and TNF-α was significantly reduced with the aid of p65NF-ĸB, while IL-1β transcription exclusively required LITAF expression/activity. Finally, IL-1β levels in plasma mirrored those in the liver and correlated with LPS levels and LITAF-positive HSCs in children with NASH.In conclusion, a more severe histological profile in paediatric NAFLD is associated with LITAF over-expression in HSCs, which in turn correlates with hepatic and circulating IL-1β levels outlining a panel of potential biomarkers of NASH-related liver damage. The in vitro study highlights the role of LITAF as a key regulator of the LPS-induced pro-inflammatory pattern in HSCs and suggests p38MAPK inhibitors as a possible therapeutic approach against hepatic inflammation in NASH.

Grass carp reovirus NS26 interacts with cellular lipopolysaccharide-induced tumor necrosis factor-alpha factor, LITAF

The nonstructural protein NS26 of grass carp reovirus (GCRV) is encoded by the 11th genomic dsRNA segment, homolog of which is not found in orthoreoviruses. The role of NS26 in GCRV pathogenesis is still unclear. Previously, grass carp LITAF/SIMPLE protein was identified as a putative binding partner for NS26 in a yeast two-hybrid screen. Here, we further characterized the association between NS26 and LITAF using in vivo and in vitro protein interaction assays. Soluble GST-NS26 and His₆-LITAF were expressed and purified from E. coli; recombinant NS26 tagged with myc and LITAF tagged with GFP were expressed in Ctenopharyngon idellus kidney cells (CIK) by transient transfection experiments. A GST pulldown assay demonstrated that GST-tagged NS26 efficiently bound to His₆-LITAF. Co-immunoprecipitation assays demonstrated that GCRV NS26 reciprocally precipitated endogenous LITAF in CIK cells. Double-immunofluorescent analyses revealed myc-NS26 colocalized with GFP-LITAF in CIK cells. Taken together, the current in vitro and in vivo data demonstrated the interaction between cellular LITAF and GCRV NS26.

Kavain Inhibition of LPS-Induced TNF-α via ERK/LITAF

Kavain, an extract from the shrub Piper Methysticum, was recently reported to modulate TNF-α expression in both human and mouse cells via regulation of LPS-Induced TNF-Alpha Factor (LITAF). The purpose of the present study was to define the molecular pathway(s) associated with Kavain effects on TNF modulation. In vitro studies using WT mouse primary macrophages showed that Kavain significantly reduced E.coli LPS-induced TNF-α production but this effect was almost abrogated in LITAF^-/- and ERK2^-/- cells. Therefore we reintroduced the ERK2 gene in ERK2^-/- cells and partially restored E.coli LPS-induced LITAF-mediated TNF-α production. The translocation of LITAF into to nucleus was found to be dependent on ERK2 S206 residue. Kavain inhibits LITAF/TNF-α expression via dephosphorylation of ERK2 in response to E.coli LPS. Finally, in vivo, Kavain had a significant anti-inflammatory effect on wild type mice that developed Collagen Antibody Induced Arthritis (CAIA), but only a minor effect in ERK2^-/- mice also affected by CAIA. Based on these findings, we concluded that ERK2 may be the kinase upstream of LITAF with its Serine residue 206 being crucial for the regulation of LPS-induced TNF-α.

Dysregulated Inflammatory Signaling upon Charcot-Marie-Tooth Type 1C Mutation of SIMPLE Protein

Endosomal trafficking is a key mechanism to modulate signal propagation and cross talk. Ubiquitin adaptors, along with endosomal sorting complex required for transport (ESCRT) complexes, are also integrated to terminate ligand-receptor activation in late endosomes and multivesicular bodies (MVBs). Within these pathways, we recently demonstrated that the protein SIMPLE is a novel player in MVB regulation. SIMPLE is also clinically important and its mutation accounts for the Charcot-Marie-Tooth type 1C (CMT1C) disease. MVB defects of mutation and deletion of SIMPLE, however, are distinct. Here, we show that MVB defects found in mutation but not deletion of SIMPLE lead to impaired turnover and accumulation of ESCRT-0 protein Hrs punctain late endosomes. We further uncover increased colocalization of ubiquitin ligase TRAF6 and Hrs in late endosomes. Upon stimulation with interkeukin-1 or transforming growth factor , prolonged activation of p38 kinase/JNK is detected, while nuclear accumulation of NF-κB and phosphorylation of SMAD2 is reduced with CMT1C mutation. The aberrant kinetics we observed in inflammatory signaling may contribute to increased tumor susceptibility and changes in the levels of chemokines/cytokines that result from CMT1C mutation. We propose that altered endosomal trafficking due to malformations of MVBs and subsequent atypical signaling kinetic may account for a toxic gain of function in CMT1C pathogenesis.

Comparative Meta-Analysis of Transcriptomics Data during Cellular Senescence and In Vivo Tissue Ageing

Several studies have employed DNA microarrays to identify gene expression signatures that mark human ageing; yet the features underlying this complicated phenomenon remain elusive. We thus conducted a bioinformatics meta-analysis on transcriptomics data from human cell- and biopsy-based microarrays experiments studying cellular senescence or in vivo tissue ageing, respectively. We report that coregulated genes in the postmitotic muscle and nervous tissues are classified into pathways involved in cancer, focal adhesion, actin cytoskeleton, MAPK signalling, and metabolism regulation. Genes that are differentially regulated during cellular senescence refer to pathways involved in neurodegeneration, focal adhesion, actin cytoskeleton, proteasome, cell cycle, DNA replication, and oxidative phosphorylation. Finally, we revealed genes and pathways (referring to cancer, Huntington's disease, MAPK signalling, focal adhesion, actin cytoskeleton, oxidative phosphorylation, and metabolic signalling) that are coregulated during cellular senescence and in vivo tissue ageing. The molecular commonalities between cellular senescence and tissue ageing are also highlighted by the fact that pathways that were overrepresented exclusively in the biopsy- or cell-based datasets are modules either of the same reference pathway (e.g., metabolism) or of closely interrelated pathways (e.g., thyroid cancer and melanoma). Our reported meta-analysis has revealed novel age-related genes, setting thus the basis for more detailed future functional studies.

Identification and expression analysis of lipopolysaccharide-induced TNF-alpha factor gene in Chinese mitten crab Eriocheir sinensis

Lipopolysaccharide-induced TNF-alpha factor (LITAF) is an important transcription factor in transcriptional regulation of TNF-alpha and other cytokines. Here we identified a full-length LITAF homolog cDNA, termed EsLITAF, that contains a 71 bp 5'-untranslated sequence, an open reading frame consisting of 381 bp, and a 208 bp 3'-untranslated sequence in Chinese mitten crab (Eriocheir sinensis), an economically important freshwater crustacean species in China. EsLITAF protein possesses a conserved C-terminal LITAF-like domain with two CXXC motifs and is comprised of 126 amino acids with a theoretical molecular mass of 13.1 kDa and an isoelectric point of 6.36. Blast search against GenBank database revealed that EsLITAF protein shared the highest sequence identity (84%) with the counterpart of Pacific white shrimp (Litopenaeus vannamei). EsLITAF mRNA transcript expresses ubiquitously in all examined tissues with the highest expression in hepatopancreas and lowest expression in haemocytes. Furthermore, EsLITAF mRNA expression could be significantly and rapidly induced in haemocytes by LPS and Poly(I:C) stimulations in vitro. Moreover, EsLITAF gene expression was up-regulated in haemocytes, gill and hepatopancreas after Edwardsiella tarda and Vibrio anguillarum challenges. Taken together, we have identified and characterized a new crustacean LITAF homolog from the Chinese mitten crab.

Peimine impairs pro-inflammatory cytokine secretion through the inhibition of the activation of NF-κB and MAPK in LPS-induced RAW264.7 macrophages

In the previous study, we found that peimine has good anti-inflammatory effects in vivo. However, the anti-inflammatory mechanism of peimine remains unclear. We, therefore, assessed the effects of peimine on inflammatory cytokines in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. We found that peimine (0-25 mg/L) significantly inhibited tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β, and increased IL-10 production. Furthermore, peimine significantly inhibited the phosphorylation of p38, ERK and c-jun N-terminal kinase (JNK) as well as decreased p65 and IκB. The present results indicate that peimine inhibits the production of inflammatory cytokines induced by LPS through blocking MAPKs and NF-κB signaling pathways.

Arthritis severity locus Cia4 is an early regulator of IL-6, IL-1β, and NF-κB activators' expression in pristane-induced arthritis

Cia4 is a locus on rat chromosome 7 that regulates disease severity and joint damage in models of rheumatoid arthritis, including pristane-induced arthritis (PIA). To identify molecular processes regulated by Cia4, synovial tissues from MHC-identical DA (severe erosive) and DA.F344(Cia4) congenics (mild nonerosive) rats were collected at preclinical and recent onset stages following the induction of PIA and analyzed for gene expression levels. Il6 levels were significantly higher in DA compared with congenics on day 10 (135-fold) after PIA induction (preclinical stage) and remained increased on days 14 (47.7-fold) and 18 (29.41-fold). Il6 increased before Il1b suggesting that Il6 could be driving Il1b expression and early synovial inflammation; 187 genes had significantly different expression levels and included inflammatory mediators increased in DA such Slpi (10.94-fold), Ccl7 (5.17-fold), and Litaf (2.09-fold). Syk or NF-κB activating and interacting genes, including Cd74 Ccl21, were increased in DA; 59 genes implicated in cancer-related phenotypes were increased in DA. Genes involved in cell metabolism, transport across membranes, and tissue protection such as Dgat1, Dhcr7, and Slc1a1 were increased in DA.F344(Cia4) congenics; 21 genes differentially expressed or expressed in only one of the strains were located within the Cia4 interval and could be the gene accounting for the arthritis effect. In conclusion, the Cia4 interval contains at least one new arthritis gene that regulates early Il6, Il1b expression, and other inflammatory mediators. This gene regulates the expression of cancer genes that could mediate the development of synovial hyperplasia and invasion, and cartilage and bone destruction.

Mutation of SIMPLE in Charcot-Marie-Tooth 1C alters production of exosomes

Mutations in the protein SIMPLE account for the rare autosomal-dominant demyelination in type 1C CMT patients (CMT1C). SIMPLE plays a role in the production of exosomes. Dysregulated endosomal trafficking and changes in exosome-mediated intercellular communications might account for CMT1C molecular pathogenesis.

Charcot–Marie–Tooth (CMT) disease is an inherited neurological disorder. Mutations in the small integral membrane protein of the lysosome/late endosome (SIMPLE) account for the rare autosomal-dominant demyelination in CMT1C patients. Understanding the molecular basis of CMT1C pathogenesis is impeded, in part, by perplexity about the role of SIMPLE, which is expressed in multiple cell types. Here we show that SIMPLE resides within the intraluminal vesicles of multivesicular bodies (MVBs) and inside exosomes, which are nanovesicles secreted extracellularly. Targeting of SIMPLE to exosomes is modulated by positive and negative regulatory motifs. We also find that expression of SIMPLE increases the number of exosomes and secretion of exosome proteins. We engineer a point mutation on the SIMPLE allele and generate a physiological mouse model that expresses CMT1C-mutated SIMPLE at the endogenous level. We find that CMT1C mouse primary embryonic fibroblasts show decreased number of exosomes and reduced secretion of exosome proteins, in part due to improper formation of MVBs. CMT1C patient B cells and CMT1C mouse primary Schwann cells show similar defects. Together the data indicate that SIMPLE regulates the production of exosomes by modulating the formation of MVBs. Dysregulated endosomal trafficking and changes in the landscape of exosome-mediated intercellular communications may place an overwhelming burden on the nervous system and account for CMT1C molecular pathogenesis.

Novel transcriptional regulation of VEGF in inflammatory processes

Vascular endothelial growth factor (VEGF) is a critical angiogenic factor affecting endothelial cells, inflammatory cells and neuronal cells. In addition to its well-defined positive role in wound healing, pathological roles for VEGF have been described in cancer and inflammatory diseases (i.e. atherosclerosis, rheumatoid arthritis, inflammatory bowel disease and osteoarthritis). Recently, we showed that transcription factors LITAF and STAT6B affected the inflammatory response. This study builds upon our previous results in testing the role of mouse LITAF and STAT6B in the regulation of VEGF-mediated processes. Cells cotransfected with a series of VEGF promoter deletions along with truncated forms of mLITAF and/or mSTAT6B identified a DNA binding site (between −338 and −305 upstream of the transcription site) important in LITAF and/or STAT6B-mediated transcriptional regulation of VEGF. LITAF and STAT6B corresponding protein sites were identified. In addition, siRNA-mediated knockdown of mLITAF and/or mSTAT6B leads to significant reduction in VEGF mRNA levels and inhibits LPS-induced VEGF secretion in mouse RAW 264.7 cells. Furthermore, VEGF treatment of mouse macrophage or endothelial cells induces LITAF/STAT6B nuclear translocation and cell migration. To translate these observations in vivo, VEGF164-soaked matrigel were implanted in whole-body LITAF-deficient animals (TamLITAF^−/−), wild-type mice silenced for STAT6B, and in respective control animals. Vessel formation was found significantly reduced in TamLITAF^−/− as well as in STAT6B-silenced wild-type animals compared with control animals. The present data demonstrate that VEGF regulation by LITAF and/or STAT6B is important in angiogenesis signalling pathways and may be a useful target in the treatment of VEGF diseases.

LITAF (SIMPLE) regulates Wallerian degeneration after injury but is not essential for peripheral nerve development and maintenance: implications for Charcot-Marie-Tooth disease

Missense mutations affecting the LITAF gene (also known as SIMPLE) lead to the dominantly inherited peripheral neuropathy Charcot-Marie-Tooth disease type 1C (CMT1C). In this study, we sought to determine the requirement of Litaf function in peripheral nerves, the only known affected tissue in CMT1C. We reasoned that this knowledge is a prerequisite for a thorough understanding of the underlying disease mechanism with regard to potential contributions by Litaf loss of function. In addition, we anticipated to obtain valuable information about the basic function of the Litaf protein in peripheral nerves. To address these issues, we generated mice without Litaf expression using gene disruption in embryonic stem cells and analyzed Litaf-deficient peripheral nerves during development, in maintenance, and after injury. Our results show that Litaf function is not absolutely required for peripheral nerve development and maintenance. In injured nerves, however, we found that lack of Litaf led to increased numbers of macrophages during Wallerian degeneration, accelerated myelin destruction, and the emergence of more axonal sprouts. Consistent with these data, the migration of Litaf-deficient macrophages was increased upon chemokine stimulation. We conclude that loss of Litaf function is unlikely to be a major contributor to CMT1C, but modulating effects of macrophages need to be considered in the etiology of the disease.