Loureirin B ameliorates cholestatic liver fibrosis via AKT/mTOR/ATG7-mediated autophagy of hepatic stellate cells.

AIM OF THE STUDY: Chronic cholestasis leads to liver fibrosis, which lacks effective treatment. In this study, we investigated the role and mechanisms of action of loureirin B (LB) in cholestatic liver fibrosis. MATERIALS AND METHODS: Bile duct ligation (BDL)-induced hepatic fibrosis mice were used as in vivo models. Transforming growth factor-ß1 (TGF-ß1)-pretreated HSC-T6 cells were used to explore the mechanism by which LB attenuates liver fibrosis in vitro. RNA sequencing, quantitative PCR (qPCR), western blotting, immunohistochemistry and immunofluorescence were performed to detect the fibrosis markers and measure autophagy levels. Flow cytometry, cell counting kit-8 (CCK-8) assay, and 5'-ethynyl-2'-deoxyuridine (EdU) assay were conducted to detect cell proliferation and viability. GFP-RFP-LC3 adenovirus, autophagy-related protein 7 (ATG7) siRNA, and bafilomycin A1 (BafA1) were used to verify autophagic flux. RESULTS: Our results showed that LB ameliorates liver injury, inhibits collagen deposition, and decreases the expressions of fibrosis-related markers in BDL-induced mouse livers. In vitro, we found that LB inhibited proliferation and migration, promoted apoptosis, and inhibited the activation of HSC-T6 cells pretreated with TGF-ß1. RNA sequencing analysis of HSC-T6 cells showed that LB treatment predominantly targeted autophagy-related pathways. Further protein analysis indicated that LB downregulated the expression of phosphorylated AKT (p-AKT) and phosphorylated mTOR (p-mTOR), and upregulated LC3-II, p62, and ATG7 both in vivo and in vitro. Intriguingly, ATG7 inactivation reversed the antifibrotic effects of LB on HSC-T6 cells. CONCLUSIONS: LB can improve BDL-induced liver fibrosis by inhibiting the activation and proliferation of HSCs and is expected to be a promising antifibrotic drug.

TGF-ß1-triggered BMI1 and SMAD2 cooperatively regulate miR-191 to modulate bone formation.

Transforming growth factor ß 1 (TGF-ß1), as the most abundant signaling molecule in bone matrix, is essential for bone homeostasis. However, the signaling transduction of TGF-ß1 in the bone-forming microenvironment remains unknown. Here, we showed that microRNA-191 (miR-191) was downregulated during osteogenesis and further decreased by osteo-favoring TGF-ß1 in bone marrow mesenchymal stem cells (BMSCs). MiR-191 was lower in bone tissues from children than in those from middle-aged individuals and it was negatively correlated with collagen type I alpha 1 chain (COL1A1). MiR-191 depletion significantly increased osteogenesis and bone formation in vivo. Hydrogels embedded with miR-191-low BMSCs displayed a powerful bone repair effect. Mechanistically, transcription factors BMI1 and SMAD2 coordinately controlled miR-191 level. In detail, BMI1 and pSMAD2 were both upregulated by TGF-ß1 under osteogenic condition. SMAD2 activated miR-191 transcription, while BMI1 competed with SMAD2 for binding to miR-191 promoter region, thus disturbing the activation of SMAD2 on miR-191 and reducing miR-191 level. Altogether, our findings reveal that miR-191 regulated by TGF-ß1-induced BMI1 and SMAD2 negatively modulated bone formation and regeneration, and inhibition of miR-191 might be therapeutically useful to enhance bone repair in clinic.

Drug delivery system for the extended-release of larotrectinib based on a biocompatible Fe-based metal-organic framework: synthesis, characterization, in vitro release properties and antitumor evaluation.

Larotrectinib (Lar) is an orally administered tropomyosin receptor kinase (Trk) inhibitor with broad-spectrum antitumor activity that is available in clinical dosage forms as capsules and oral solutions. Currently, corresponding research is focused on developing new extended-release formulation systems for Lar. In this study, a biocompatible Fe-based metal-organic framework (Fe-MOF) carrier was synthesized by a solvent-based method, and a sustained-release drug delivery system (Lar@Fe-MOF) was constructed by nanoprecipitation and Lar loading. Lar@Fe-MOF was characterized by transmission electron microscopy (TEM), differential scanning calorimetry (DSC), fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA), and its drug loading capacity and drug release properties were measured by ultraviolet-visible (UV-vis) spectroscopy. Then, the toxicity and biocompatibility of the Fe-MOF carriers were evaluated using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) and hemocompatibility assays. Finally, the anticancer potential of Lar@Fe-MOF was investigated. The TEM results showed that Lar@Fe-MOF had a homogeneous fusiform nanostructural morphology. The DSC and FTIR results showed that Fe-MOF carriers were successfully synthesized and loaded with Lar, which was mainly in an amorphous form. Lar@Fe-MOF showed a large drug loading capacity (-10%) and significant slow-release properties in vitro. The MTT assay results showed that Lar@Fe-MOF had good dose-dependent anticancer activity. The in vivo pharmacodynamic assay results showed that Fe-MOF significantly increased the anticancer activity of Lar and was biocompatible. In conclusion, the Lar@Fe-MOF system developed in this study is a promising drug delivery platform because it is easy to manufacture, has high biocompatibility and ideal drug release and accumulation, can effectively eliminate tumors with improved safety and is expected to further expand therapeutic applications.

Evaluation of radiological and temporal characteristics of acute appendicitis on the non-enhanced computed tomography images.

PURPOSES: To investigate the relationships and interactions between temporal and radiological features of gangrene and perforation of inflamed appendices. METHODS: A total of 402 patients were included who underwent laparoscopic appendectomies between January 1, 2016 and March 30, 2020 and had pathologically proved acute appendicitis and preoperative non-enhanced CT examinations. The radiological features (appendix diameter, appendicolith, appendiceal intraluminal gas, periappendiceal gas, periappendiceal fat stranding/fluid, and short axial diameter of the mesenteric lymph nodes) were obtained from the preoperative CT images of 382 patients with visible appendices. Clinical parameters and temporal variables (pre-CT delay, preoperative delay, estimated complication delay, symptom delay, and system delay) were recorded. RESULTS: Among simple/suppurative, gangrenous, and perforated appendicitis, the radiological characteristics except for short axial diameters of lymph nodes, and the temporal variables other than system delay were significantly different. The Cox regression analysis identified the appendicolith as the independent risk factor for both gangrene and perforation of inflamed appendices by using the preoperative delay or estimated complication delay. By the preoperative delay, the median time for gangrene and perforation was 76.23 (95%CI 73.89-78.58) h and 77.55 (95%CI 74.12-80.98) h, respectively, if appendicolith was present. If estimated complication delay was used as the elapsed time and the appendicolith was perceptible, the median time for gangrene and perforation and was 72.33 (95%CI 62.93-81.74) h and 75.07 (95%CI 69.48-80.65) h, respectively. CONCLUSION: There were interactions between the time evolution and radiological features of acute appendicitis. The evaluation of gangrene and perforation rate of acute appendicitis could be benefitted from combining the preoperative delay/estimated complication delay with CT characteristics in the preoperative urgent radiological analysis.

Hypoxic ucMSC-secreted exosomal miR-125b promotes endothelial cell survival and migration during wound healing by targeting TP53INP1.

A hypoxic microenvironment is a common feature of skin wounds. Our previous study demonstrated that three-dimensional coculture of umbilical cord-derived mesenchymal stem cells (ucMSCs) and endothelial cells facilitates cell communication and host integration in skin tissue engineering. Here, we aimed to identify the mechanism by which ucMSCs affect endothelial cells under hypoxic conditions after skin injury. We demonstrate that hypoxia enhances the exosome-mediated paracrine function of ucMSCs, which increases endothelial cell proliferation and migration. In a mouse full-thickness skin injury model, ucMSC-derived exosomes can be taken up by endothelial cells and accelerate wound healing. Hypoxic exosomes lead to a better outcome than normoxic exosomes by promoting proliferation and inhibiting apoptosis. Mechanistically, microRNA-125b (miR-125b) transcription is induced by hypoxia in ucMSCs. After being packaged into hypoxic exosomes and transported to endothelial cells, miR-125b targets and suppresses the expression of tumor protein p53 inducible nuclear protein 1 (TP53INP1) and alleviates hypoxia-induced cell apoptosis. Inhibition of miR-125b-TP53INP1 interaction attenuates the protective effect of hypoxic exosomes. Moreover, artificial agomiR-125b can accelerate wound healing in vivo. Our findings reveal communication between ucMSCs and endothelial cells via exosomal miR-125b/TP53INP1 signaling in the hypoxic microenvironment and present hypoxic exosomes as a promising therapeutic strategy to enhance cutaneous repair.

miR-210 Participates in Hepatic Ischemia Reperfusion Injury by Forming a Negative Feedback Loop With SMAD4.

BACKGROUND AND AIMS: Hepatic ischemia-reperfusion (IR) injury is a major complication of liver transplantation, resection, and hemorrhagic shock. Hypoxia is a key pathological event associated with IR injury. MicroRNA-210 (miR-210) has been characterized as a micromanager of hypoxia pathway. However, its function and mechanism in hepatic IR injury is unknown. APPROACH AND RESULTS: In this study, we found miR-210 was induced in liver tissues from patients subjected to IR-related surgeries. In a murine model of hepatic IR, the level of miR-210 was increased in hepatocytes but not in nonparenchymal cells. miR-210 deficiency remarkably alleviated liver injury, cell inflammatory responses, and cell death in a mouse hepatic IR model. In vitro, inhibition of miR-210 decreased hypoxia/reoxygenation (HR)-induced cell apoptosis of primary hepatocytes and LO2 cells, whereas overexpression of miR-210 increased cells apoptosis during HR. Mechanistically, miR-210 directly suppressed mothers against decapentaplegic homolog 4 (SMAD4) expression under normoxia and hypoxia condition by directly binding to the 3' UTR of SMAD4. The pro-apoptotic effect of miR-210 was alleviated by SMAD4, whereas short hairpin SMAD4 abrogated the anti-apoptotic role of miR-210 inhibition in primary hepatocytes. Further studies demonstrated that hypoxia-induced SMAD4 transported into nucleus, in which SMAD4 directly bound to the promoter of miR-210 and transcriptionally induced miR-210, thus forming a negative feedback loop with miR-210. CONCLUSIONS: Our study implicates a crucial role of miR-210-SMAD4 interaction in hepatic IR-induced cell death and provides a promising therapeutic approach for liver IR injury.

miR-191 promotes tumorigenesis of human colorectal cancer through targeting C/EBPß.

MicroRNA-191 (miR-191), a small non-coding RNA, is involved in disease development and cancer diagnosis and prognosis. However, how miR-191 functions in colorectal cancer remains largely unclear. In this study, we show that miR-191 is highly expressed in colon tumor tissues, and that inhibition of miR-191 leads to decreased cell growth, proliferation and tumorigenicity in a xenograft model. Overexpression of miR-191 in colorectal cancer cell lines alters cell cycle progression and cell resistance to 5-Fu induced cell apoptosis. Mechanistic studies demonstrated that miR-191 directly binds to the 3'UTR of the C/EBPß mRNA and mediates a decrease in the mRNA and protein expression of C/EBPß. We further showed that C/EBPß induces growth arrest in a colorectal cancer cell line and that its expression is negatively correlated with the miR-191 level in patient samples. Our findings suggest that miR-191 may be a potential gene therapy target for the treatment of colorectal cancer.

Endogenous language control in Chinese-English switching: an event-related potentials study.

The neural basis of language switching, especially endogenous language control, remains largely unclear. We used a cue-stimulus paradigm and measured behavioral indices and scalp event-related potentials to investigate the endogenous control of switching between Chinese and English. In the experiment, unbalanced Chinese (L1) - English (L2) speakers named pictures in L1 or L2 according to an auditory cue presented 700 ms (cue-stimulus interval) before the picture onset. The reaction time (RT) was longer in the switch condition and the switch cost (difference of RTs between switch and repeat conditions) of L1 (L2→L1) was greater than L2 (L1→L2). P2 component elicited by the cue onset showed the neural switch cost of L1 at the frontocentral regions, with a leftward distribution, but not the switch cost of L2. The greater switch cost of L1 in behavioral responses and neural activity suggests that the frontocentral areas play an important role in endogenous language control, and switching back to the native language might require more endogenous control.

Hepatocellular carcinoma and macrophage interaction induced tumor immunosuppression via Treg requires TLR4 signaling.

AIM: To investigated the interaction between toll-like receptor 4 (TLR4)-activated hepatoma cells and macrophages in the induction of tumor-immune suppression mediated by CD4+CD25(high) family of transcription factor P3 (FOXP3) regulatory T cells (Tregs). METHODS: The proportion of FOXP3+ Tregs was identified in peripheral blood and tumor tissues of 60 hepatocellular carcinoma (HCC) patients. TLR4 expression was examined in tumor tissues and cell lines. The correlation was examined between FOXP3+ Tregs in peripheral blood and TLR4 expression of HCC tissues. Following activation of TLR4 in H22 murine hepatoma cells pre-incubated with lipopolysaccharide (LPS) and co-cultured with macrophage cell line RAW246.7, the synthesis of cytokines tumor necrosis factor-α, CCL22, and interleukin (IL)-10 by the two cell lines was detected and analyzed. RESULTS: FOXP3+ Tregs were enriched in tumor sites, and circulating FOXP3+ Tregs were increased in HCC patients in correlation with multiple tumor foci and up-regulated TLR4 expression in HCC tissues. Semi-quantitative analysis indicated that TLR4 was over-expressed in HCC compared with the matched normal tissues. Cell cultivation experiments indicated that the mRNAs of IL-10 and CCL22 were significantly up-regulated in the RAW246.7 cell line when co-cultured with LPS pre-incubated H22 cells. CONCLUSION: In hepatoma cell lines, TLR4 may indirectly facilitate the recruitment of Tregs to the tumor site and promote intrahepatic metastasis through its interaction with macrophages.

Visual working memory load-related changes in neural activity and functional connectivity.

BACKGROUND: Visual working memory (VWM) helps us store visual information to prepare for subsequent behavior. The neuronal mechanisms for sustaining coherent visual information and the mechanisms for limited VWM capacity have remained uncharacterized. Although numerous studies have utilized behavioral accuracy, neural activity, and connectivity to explore the mechanism of VWM retention, little is known about the load-related changes in functional connectivity for hemi-field VWM retention. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we recorded electroencephalography (EEG) from 14 normal young adults while they performed a bilateral visual field memory task. Subjects had more rapid and accurate responses to the left visual field (LVF) memory condition. The difference in mean amplitude between the ipsilateral and contralateral event-related potential (ERP) at parietal-occipital electrodes in retention interval period was obtained with six different memory loads. Functional connectivity between 128 scalp regions was measured by EEG phase synchronization in the theta- (4-8 Hz), alpha- (8-12 Hz), beta- (12-32 Hz), and gamma- (32-40 Hz) frequency bands. The resulting matrices were converted to graphs, and mean degree, clustering coefficient and shortest path length was computed as a function of memory load. The results showed that brain networks of theta-, alpha-, beta-, and gamma- frequency bands were load-dependent and visual-field dependent. The networks of theta- and alpha- bands phase synchrony were most predominant in retention period for right visual field (RVF) WM than for LVF WM. Furthermore, only for RVF memory condition, brain network density of theta-band during the retention interval were linked to the delay of behavior reaction time, and the topological property of alpha-band network was negative correlation with behavior accuracy. CONCLUSIONS/SIGNIFICANCE: We suggest that the differences in theta- and alpha- bands between LVF and RVF conditions in functional connectivity and topological properties during retention period may result in the decline of behavioral performance in RVF task.

[Genetic polymorphisms of 9 non-combined of DNA index system short tandem repeat loci in Guangdong Han population].

OBJECTIVE: To investigate the genetic polymorphisms and their forensic application of 9 non-combined of DNA index system (CODIS) short tandem repeat(STR) loci in Guangdong Han population. METHODS: DNA samples from 500 unrelated individuals were extracted and amplified with fluorescence labeled multiplex PCR system. PCR products were separated and genotyped with capillary electrophoresis. RESULTS: One hundred and fifteen alleles and 160 genotypes were observed in the 9 STR loci, respectively. The heterozygosity was 0.824-0.884, the discrimination power (DP) was 0.925-0.969 and the polymorphism information content (PIC) was 0.77-0.86, respectively. The distribution met the Hardy-Weinberg equilibrium (P > 0.05). The total discrimination power was 1.00 x 10(-13), the combined probability of exclusion for trio-paternity testing was 0.999989488. The combined probability of exclusion for duo-paternity testing was 0.873436. CONCLUSION: The 9 STR loci are powerful and reliable for personal identification and paternity testing. They can be used as supplementary loci in fatherless (motherless) testing or cases with mutation events.

Endogenous danger signals trigger hepatic ischemia/reperfusion injury through toll-like receptor 4/nuclear factor-kappa B pathway.

BACKGROUND: Restoration of blood flow to the ischemic liver lobes may paradoxically exacerbate tissue injury, which is called hepatic ischemia/reperfusion injury (IRI). Toll-like receptor 4 (TLR4), expressed on several liver cell types, and the nuclear factor-kappa B (NF-kappaB) signaling pathway are crucial to mediating hepatic inflammatory response. Because IRI is essentially a kind of profound acute inflammatory reaction evoked by many kinds of danger signals, we investigated TLR4/NF-kappaB signaling pathway activation in a murine model of partial hepatic IRI. METHODS: Wild-type mice (WT, C3H/HeN) or TLR4 mutant mice (C3H/HeJ) were subjected to 45 minutes of partial hepatic ischemia followed by 1 hour, 3 hours of reperfusion. Sham group accepted the same procedure without the obstruction of blood supply. At the end of reperfusion, the compromise of liver function and the histological change of liver sections were measured as the severity of liver injury. The level of endotoxin in the portal vein was measured by limulus assay. NF-kappaB activation was determined by electrophoretic mobility shift assay (EMSA). The levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) in systemic blood after hepatic IRI were assessed by enzyme-linked immunosorbent assay (ELISA). RESULTS: The compromise of liver function and the morphological injuries in mutant mice were relieved more markedly than those in WT mice after partial hepatic IRI. NF-kappaB activation in WT mice was stronger than that in TLR4 mutant mice, and both were stronger than those in the sham operated mice (P < 0.01). Endotoxin in each group was undetectable. The levels of TNF-alpha and IL-1beta in systemic blood were elevated in both strains, but lower in the sham operated group. These mediators were significantly decreased in TLR4 mutant mice compared with those in WT mice (P < 0.01). CONCLUSIONS: The TLR4/NF-kappaB signaling pathway may mediate hepatic IRI triggered by endogenous danger signals. Inhibition of the TLR4/NF-kappaB pathway may be a potential therapeutic target for attenuating ischemia/reperfusion-induced tissue damage in some clinical settings.

[Regulation of axon guidance cue netrin-1 on angiogenesis].

OBJECTIVE: To study the effect of netrin-1, an axon guidance cue, on angiogenesis. METHODS: Human umbilical cord vein endothelial cells (HUVECs) were isolated and cultured. Reverse transcription and polymerase chain reaction (RT-PCR) was used to detect all the known receptors of netrin-1 in the HUVECs. Netrin-1 and vascular endothelial growth factor (VEGF) of the concentration of 10 ng/ml were added into the culture fluid respectively for 72 h, cholecystokinin-8 (CCK-8) was added, and then enzyme mark instrument was used to calculate the relative absorbance (A value). Other HUVECs were added into the upper chamber of the Transwell co-culture system and netrin-1 of different concentrations and VEGF of the concentration of 10 ng/ml were added into the lower chamber respectively for 6 h, and then invert microscopy were used to observe the migration of HUVECs. Matrigel was added into the 96-well plate, and HUVECs and netrin-1 of different concentrations were added into the wells, then contrast microscopy was used to calculate the tube formation. Corneal micropocket assay was performed on 96 rabbits to determine the corneal neovascularization (CNV) with treatment with different concentrations of netrin-1. RESULTS: Of the 6 ligands only the receptor UNC5B was expressed in the HUVECs. The cell counting kit-8 assay showed that the proliferation of HUVECs was promoted when the concentration of netrin-1 was under 500 ng/ml, especially when the concentration was 50 ng/ml, however, when the netrin-1 concentrations were 1000 to 5000 ng/ml the proliferation of the HUVECs was inhibited (P<0.05). The migration of HUVECs was promoted when the concentration of netrin-1 was under 500 ng/ml, especially when the concentration was 100 ng/ml, however, when the netrin-1 concentrations were 1000 to 5000 ng/ml the migration of the HUVECs was inhibited (P<0.05). Normally HUVECs formed branch-like and tube-like structure in the culture plate, netrin-1 did not influence the tube formation when the concentration was under 500 ng/ml, and inhibited the tube formation when the concentration was 1000 approximately 5000 ng/ml (P<0.05). Rabbit corneal micropocket assay showed that netrin-1 of the concentration of 100 ng/ml and VEGF of the concentration of 10 ng/ml promoted the angiogenesis, however, the netrin-1 of the concentration of 5000 ng/ml inhibited the angiogenesis. CONCLUSION: Netrin-1 shows has a dual function, both promotive or inhibitory effects, on angiogenesis, depending on the concentration and its inhibitive effect is mediated by UNC5B.

Axon guidance cue Netrin-1 has dual function in angiogenesis.

Angiogenesis is an important process required for cancer. Netrin-1, an axon guidance cue used to guide axon pathfinding and regulate neuron proliferation, may also be involved in the angiogenesis respecting the anatomical similarity of neural and vascular system. Surprisingly, we demonstrate that Netrin-1 has a dual role in regulating angiogenesis. It produces either facilitative or inhibitory effect depending upon its concentration. Moreover, UNC5B was the only subtype of Netrin-1 receptors detected in HUVECs in our study. Target knockdown of UNC5B in vascular endothelial cells, using a specific siRNA, resulted in a significant in cell proliferation and migration along with a loss of the inhibitory effect, regardless of concentration. Our study revealed Netrin-1 as a dual-function regulator of angiogenesis and its possible mechanism. The study might be used in anti-angiogenic therapies of cancer in the future.

[Inhibition of rat RAW264.7 macrophage inflammatory cytokines release by small hairpin RNAi targeting Toll-like receptor].

OBJECTIVE: To construct a eukaryotic expression vector carrying the small hairpin RNA (shRNA) for Toll-like receptor 4 (TLR4) mRNA and a reporter gene of enhanced green fluorescence protein (EGFP) and study the inhibition of cytokine release by rat RAW264.7 macrophages induced by lipopolysaccharide (LPS) stimulation through transfection and expression of shRNA targeting TLR4 gene via the RNAi mechanism. METHODS: The H1 promotor and double BbsIrestrict endoenzyme site from the plasmid psiRNA-hH1neo were cloned into the reporter gene plasmid pEGFP-C1 at the MluIrestrict endoenzymic site, thus forming the plasmid pEGFP-H1/siRNA containing Bbs site and reporter EGFP gene. Then an oligo nuclear hairpin sequence targeting TLR4 gene was designed by the internet tool siRNA Wizard and then inserted into the plasmid pEGFP-H1/siRNA so as to form the plasmid pEGFP-H1/TLR4-siRNA. Rat macrophages of the line RAW264.7 were cultured and transfected with pEGFP-H1/TLR4-siRNA mediated by lipofectamine 2000. Another RAW264.7 cells were transfected with pEGFP-H1/control sequence-siRNA or blank plasmid. Lipopolysaccharide was added into the 3 kinds of culture fluid for 2 and 68 hours respectively. ELSA was used to detect the levels of tumor necrosis factor-alpha (TNF-alpha) in the supernatants. RESULTS: Restriction endonuclease analysis showed that the construction pEGFP-H1/TLR4-siRNA carrying hairpin RNA for TLR4 gene and reporter EGFP gene was successful. The expression of EGFP gene was 50% +/- 8%. The TNF-alpha level of the TLR4-siRNA transfection group 2 hours and after transfection was 825 pg/ml +/- 136 pg/ml, significantly lower than those of the pEGFP-H1/control sequence-siRNA and blank plasmid groups (2190 pg/ml +/- 359 pg/ml and 1265 pg/ml +/- 283 pg/ml respectively, both P < 0.01). The TNF-alpha level of the TLR4-siRNA transfection group 8 hours and after transfection was 1179 pg/ml +/- 240 pg/ml, significantly lower than those of the pEGFP-H1/control sequence-siRNA and blank plasmid groups (4720 pg/ml +/- 227 pg/ml and 4689 pg/ml +/- 310 pg/ml respectively, both P < 0.01). CONCLUSION: shRNA targeting TLR4 gene can inhibit the TNF-alpha release by RAW264.7 cells evoked by LPS.

The relationship between activation of TLR4 and partial hepatic ischemia/reperfusion injury in mice.

BACKGROUND: Toll-like receptors (TLRs) are a group of evolutionarily conserved pattern recognition receptors involved in the activation of the immune system in response to various pathogens. In this study, we elucidated the relationship between activation of TLR4 and liver injury in partial hepatic ischemia/reperfusion (I/R) injury in mice. METHODS: BALB/c mice were used in a model of partial hepatic I/R injury, and the changes of TLR4 gene expression in ischemic liver lobes were detected with real-time polymerase chain reaction (RT-PCR). The levels of plasma ALT and endotoxin in the portal vein were measured. TLR4-deficient mice (C3H/Hej) and wild type mice (C3H/Heouj) were used in a model of I/R injury; liver function impairment and the level of serum TNF-alpha were observed. RESULTS: After one hour ischemia, the expression of TLR4 mRNA increased at the 1st, 3rd hour of reperfusion, indicating the value of deltaCt (1st hour: 1.21+/-0.87 vs. 5.85 +/-1.07, t=13.72, P<0.01; 3rd hour: 0.85+/-0.92 vs. 6.11+/-1.24, t=16.33, P<0.01). No endotoxemia developed in every group of mice. At the 3rd hour of reperfusion, the level of serum TNF-alpha was significantly higher than that of sham group (Hej: 152+/-43 pg/ml vs. 18+/-10 pg/ml, t=5.26, P<0.01; Heouj: 249+/-52 pg/ml vs. 25+/-13 pg/ml, t=7.24, P<0.01). At the 1st, 3rd hour reperfusion, the level of plasmid ALT in Hej mice was lower than that in Heouj mice (1st hour 662+/-106 U/L vs. 1216+/-174 U/L, t=4.21, P<0.01; 3rd hour 1145+/-132 U/L vs. 2958+/-187 U/L, t=13.72, P<0.01). The level of serum TNF-alpha was lower than that in Heouj mice (152+/-43 U/L vs. 249+/-52 U/L, t=3.94, P<0.01) at the 3rd hour reperfusion. CONCLUSION: TLR4 activation causes partial hepatic I/R injury through release of TNF-alpha.