Under hypoxic conditions, exercise capacity declines, accompanied by the significant activation of the arachidonic acid (AA) metabolism. The AA metabolism pathway has been confirmed to participated in the regulation of hypoxic inflammation. However, the relationship between hypoxia and AA metabolism remains largely unclear and whether targeting AA metabolism represents an effective strategy to improve exercise capacity is not clear. Celecoxib, a cyclooxygenase-2 (COX-2) selective inhibitor, has been showed to effectively inhabit AA metabolism with minimal side-effects. In this study, celecoxib was used to inhibit AA metabolism in both murine and cellular models, and COX-2-specific siRNA was employed in cells. COX-2 expression was assessed by quantitative PCR (qPCR) and Western blots (WB), and the effect of celecoxib on exercise capacity was evaluated. Additionally, RNA-Seq and Seahorse XF assays were performed to further investigate the underlying mechanism. We found that celecoxib-mediated inhibition of COX-2 improved could improve explosive exercise capacity of hypoxic mice. Moreover, celecoxib could reactivate the GSTA pathway in hypoxic cells, attenuated reactive oxygen species (ROS) damage, and decrease oxygen and energy consumption. Our study reveals that celecoxib, via selective targeting of COX-2, represents a novel therapeutic approach to enhancing explosive exercise capacity under hypoxic conditions.
Hypoxia-induced right ventricular (RV) remodeling and dysfunction present a significant health risk to populations experiencing prolonged hypoxic conditions. Intense light, a noninvasive and easily implemented intervention, has previously been reported to exert cardioprotective effects by improving myocardial ischemia. However, whether intense light provides protective benefits against RV remodeling and the underlying mechanisms remain largely unexplored. In this study, we established mouse models exhibiting RV remodeling and dysfunction through long-term hypoxia to investigate the protective effects of intense light. Echocardiography, hemodynamic parameters measurements, and Fulton index assessments were employed to evaluate RV dysfunction and remodeling. Additionally, single-nuclei RNA sequencing, immunohistochemistry, immunofluorescence, and western blotting analyses were conducted to identify targeted genes in macrophage-associated inflammation within the heart. The results indicate that intense light significantly alleviates hypoxia-induced RV remodeling and dysfunction in mice. Intense light may mediate macrophage-associated inflammation through differentially expressed genes, including PF4, as well as the quantity of macrophages in the right ventricles (RVes). Resident macrophages (Res_Macro) demonstrate cardioprotective effects when intense light is applied, which mitigates RV remodeling. Our findings also suggest that PF4 expression and the presence of PF4+ resident macrophages (Res_PF4+_Macro) are linked to the attenuation of RV remodeling by intense light. Macrophage PF4 expression and the quantity of PF4+ macrophages in the RVes are closely associated with the levels of RV remodeling and dysfunction. This study unveils a novel noninvasive approach for the prevention of RV remodeling and dysfunction induced by hypoxia, and indicates that Res_PF4+_Macro and PF4 expression could be potential intervening targets.
BACKGROUND:Hypobaric hypoxia (HH)-induced acute lung injury (ALI) is a growing concern. Tryptophan metabolite 5-Methoxytryptophan (5-MTP) is a recently identified endothelial protective factor. However, the role of 5-MTP in HH-induced ALI remains unclear. METHODS AND RESULTS:Forty healthy male human participants were enrolled in Chongqing (200 m) to travel to Golmud (4260 m). We found the decreased plasma 5-MTP level was correlated with HH-induced blood oxygen desaturation and acute mountain sickness. ELISA showed 5-MTP levels decreased in the plasma and lungs of ALI mice (male 6-8 weeks C57BL/6J), and also in the supernatant of mouse pulmonary microvascular endothelial cells (PMVECs) after hypoxia. Immunoblotting showed the synthetase Asmt was downregulated in mice lungs and PMVECs after hypoxia, which could be restored by si-Hif1α or NF-κB inhibitor. ChIP assays confirmed that hypoxia enhanced NF-κB p50 binding in Asmt promotor. Application of 5-MTP protected the hyperpermeability in ALI. The transmission electron microscope of mice lungs showed 5-MTP alleviated the endothelial barrier disruption and lipoperoxidation injury. Using limited proteolysis combined with mass spectrometry, we revealed Prdx6-Ser32 as the direct target of 5-MTP, consistent with molecular docking. Molecular dynamics simulation, cellular thermal shift assays and microscale thermophoresis confirmed the interaction. 5-MTP prevented the hypoxia-induced decline of Prdx6 and lipoperoxidation. By MG132 and BafA1, we found hypoxia promoted the lysosomal degradation of Prdx6. Immunoblotting and immunofluorescence showed 5-MTP could reduce hypoxia-induced increased lysosomal localization of Prdx6. Prdx6-S32A impaired the protective effects of 5-MTP on PMVECs, and also the lysosomal localization of Prdx6. Adeno-associated viruses were injected intratracheally to confirm Prdx6-S32A also impaired the therapeutic effects of 5-MTP on ALI mice. CONCLUSION:5-MTP is a predictive biomarker of hypoxic maladaptation. The restoration of 5-MTP attenuated ALI by inhibiting lipoperoxidation and protecting endothelial barrier via directly interaction with Ser32 site of Prdx6 to prevent its lysosomal degradation.
Reperfusion through thrombolytic therapy or primary percutaneous coronary intervention is commonly used to deal with acute myocardial infarction. However, the reperfusion procedure is accompanied by myocardial ischemia-reperfusion injury (MIRI). Currently, there is no therapeutics that can effectively deal with MIRI in clinical practice. Herein, the potential of ceria nanoparticles (CNPs) coated by different ligands in the treatment of rat MIRI is evaluated. The results demonstrate that CNPs can effectively modulate the oxidative stress in the heart tissue through the elimination of reactive oxygen species (ROS) and stimulation of endogenous antioxidant system. The inhibition of oxidative stress results in the reduction of p-Drp1 (Ser 616) which is critical in driving the fission and fragmentation of mitochondria. The improved mitochondrial dynamics saves the cardiomyocytes from apoptosis and reduces the acute injury of left ventricular wall during the MIRI. The ejection function of the left ventricle for both the short-term and long-term MIRI rats is well preserved. We therefore believe based on these results that the administration of CNPs is beneficial in the attenuation of MIRI during the acute stage. These findings provide useful information for the future fabrication of inorganic antioxidant nanomedicine for the treatment of MIRI.
AIMS:Adenosine 2A receptor (A2A R) is widely expressed in the brain and plays important roles in neuroinflammation, and the nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain-containing protein 3 (NLRP3) inflammasome is a crucial component of the innate immune system while the regulation of A2A R on it in the central nervous system (CNS) has not been clarified. METHODS:The effects of microglial A2A R on NLRP3 inflammasome assembly and activation were investigated in wild-type, A2A R- or NLRP3-knockout primary microglia with pharmacological treatment. Microglial A2A R or NLRP3 conditional knockout mice were used to interrogate the effects of this regulation on neuroinflammation posttraumatic brain injury (TBI). RESULTS:We found that A2A R directly interacted with NLRP3 and facilitated NLRP3 inflammasome assembly and activation in primary microglia while having no effects on mRNA levels of inflammasome components. Inhibition of the interaction via A2A R agonist or knockout attenuated inflammasome assembly and activation in vitro. In the TBI model, microglial A2A R and NLRP3 were co-expressed at high levels in microglia next to the peri-injured cortex, and abrogating of this interaction by microglial NLRP3 or A2A R conditional knockout attenuated the neurological deficits and neuropathology post-TBI via reducing the NLRP3 inflammasome activation. CONCLUSION:Our results demonstrated that inhibition of the interaction between A2A R and NLRP3 in microglia could mitigate the NLRP3 inflammasome assembly and activation and ameliorate the neuroinflammation post-TBI. It provides new insights into the effects of A2A R on neuroinflammation regulation post-TBI and offers a potential target for the treatment of NLRP3 inflammasome-related CNS diseases.
Evidence is mounting that sinomenine and peroxisome proliferator-activated receptor β/δ (PPARβ/δ) are effective against lipopolysaccharide (LPS)-induced acute lung injury (ALI) via anti-inflammatory properties. However, it is unknown whether PPARβ/δ plays a role in the protective effect of sinomenine on ALI. Here, we initially observed that preemptive administration of sinomenine markedly alleviated lung pathological changes, pulmonary edema and neutrophil infiltration, accompanied by inhibition of the expression of the pro-inflammatory cytokines Tumor necrosis factor-α (TNF-α) and Interleukin-6 (IL-6), which were largely reversed following the addition of a PPARβ/δ antagonist. Subsequently, we also noticed that sinomenine upregulated adenosine A2A receptor expression in a PPARβ/δ-dependent manner in LPS-stimulated bone marrow-derived macrophages (BMDMs). Further investigation indicated that PPARβ/δ directly bound to the functional peroxisome proliferator responsive element (PPRE) in the adenosine A2A receptor gene promoter region to enhance the expression of the adenosine A2A receptor. Sinomenine was identified as a PPARβ/δ agonist. It could bind with PPARβ/δ, and promote the nuclear translocation and transcriptional activity of PPARβ/δ. In addition, combined treatment with sinomenine and an adenosine A2A receptor agonist exhibited synergistic effects and better protective roles than their single use against ALI. Taken together, our results reveal that sinomenine exerts advantageous effects on ALI by activating of PPARβ/δ, with the subsequent upregulation of adenosine A2A receptor expression, and provide a novel and potential therapeutic application for ALI.
Osteogenic differentiation of periodontal ligament stem cells (PDLSCs) is limited in hypoxia, and HIF-1α is key to the response to hypoxia. However, its mechanisms remain largely unknown. This study discovered an osteogenesis-related gene sensitive to hypoxia in PDLSCs, and investigated the molecular mechanisms between HIF-1α and the gene. NOG, a gene that negatively regulates osteogenesis, was discovered by RNA-seq. Under normoxic conditions, HIF-1α overexpression led to enhanced expression of NOG/Noggin and inhibited the expression of osteogenesis-related genes, while inhibition of HIF-1α reversed this effect. The expression of HIF-1α, NOG/Noggin and the osteogenesis-related genes were detected by qRT-PCR or Western blot. Mechanistically, we verified that HIF-1α binds to the hypoxia response element (-1505 to -1502) in the promotor of NOG to enhance secretion of Noggin by chromatin immunoprecipitation and a dual-luciferase reporter assay. IHC staining findings in an animal model verified that Noggin-associated osteogenic differentiation was inhibited in hypoxia. NOG displayed a concordant relationship with HIF-1α, and secreted more with increasing of HIF-1α. Hypoxia stabilized HIF-1α, which bound to the HRE (-1505 to -1502) of the NOG promotor to enhance NOG transcription resulted in inhibiting osteogenic differentiation of PDLSCs. This study offers a promising therapy for periodontitis.
NLRP3 inflammasome plays a crucial role in the innate immune system. Our group previously reported that the microglial adenosine 2A receptor (A(2A)R) regulates canonical neuroinflammation, which is affected by the glutamate concentration. However, the regulatory effect of A(2A)R on NLRP3 inflammasome and the effects of glutamate concentration remain unknown. Therefore, we aimed to investigate the regulatory effect of microglial A(2A)R on NLRP3 inflammasome assembly and activation as well as the effects of glutamate concentration on the inflammasome assembly and activation. Experiments were conducted on magnetically sorted primary microglia from P14 mice. The results showed that pharmacological A(2A)R activation ameliorated NLRP3 activation under no or low glutamate concentrations, but this effect was reversed by high glutamate concentrations. Moreover, the mRNA levels of NLRP3 inflammasome-related genes were not affected by A(2A)R activation or the glutamate concentration. We further demonstrated that A(2A)R activation inhibited the interaction between NLRP3 and caspase 1 under no or low glutamate concentrations while promoting their interaction under high glutamate concentrations. The oligomerization of ASC also showed a similar trend. In conclusion, our findings proved that the high glutamate concentration could reverse the inhibition of A(2A)R on NLRP3 inflammasome activation by modulating its assembly, which provides new insights into the regulatory effect of A(2A)R on neuroinflammation under different pathological conditions.
The current study aimed to investigate the effects of sodium butyrate on the level of colonic protein IRAK1 (interleukin-1 receptor-associated kinase 1) in irritable bowel syndrome (IBS) models as well as revealing the relationship between IRAKI level and visceral sensitivity during the progression of IBS. IBS symptoms were induced using TNBS (2,4,6-trinitrobenzene sulfonic acid) in mice and using IL-33 in HT-29 cells, which were then hanlded with sodium butyrate (100 mM for each mice and 0.05 M for HT-29 cells). The threshold of visceral pain and the expression of IRAKI in mice, and the level of IRAKI in HT-29 cells were detected. The data showed that the level of IRAK1 in IBS mice was higher than that in the control group, while the pre-treatment with sodium butyrate could solidy suppressed the level of IRAK1. Morevoer, it was found that the level of IRAK1 was negatively correlated with the pain threshold. In in vitro assays, the level of IRAK1 was firstly induced by IL-33 stimulation and then suppressed by sodium butyrate pretreatment. Collectively, the level of IRAKI showed an obvioulty positive relation with visceral hypersensitivity in IBS models, and the treatment with sodium butyrate could alleviate visceral hypersensitivity by inhibiting the expression of IRAKI.
Background: Emerging evidence suggests that epithelial mesenchymal transition (EMT) and epigenetic mechanisms promote metastasis . Histone deacetylases (HDACs) and noncoding RNAs (ncRNAs) are important epigenetic regulators. Here, we elucidated a novel role of histone deacetylase 2 ( HDAC2 ) in regulating EMT and CRC metastasis via ncRNA. Methods: The expression of HDACs in CRC was analyzed using the public databases and matched primary and metastatic tissues, and CRC cells with different metastatic potentials (DLD1, HCT116, SW480 and SW620). Microarray analysis was used to identify differential genes in parental and HDAC2 knockout CRC cells. EMT and histone modifications were determined using western blot and immunofluorescence. Migration ability was assessed by transwell assay, and metastasis was assessed in vivo using a tail vain injection. Gene expression and regulation was assessed by RT-PCR, chromatin immunoprecipitation and reporter assays. Protein interaction was assessed by immunoprecipitation. Specific siRNAs targeting H19 , SP1 and MMP14 were used to validate their role in HDAC2 loss induced EMT and metastasis. Results: Reduced HDAC2 expression was associated with poor prognosis in CRC patients and found in CRC metastasis. HDAC2 deletion or knockdown induced EMT and metastasis by upregulating the long noncoding RNA H19 ( LncRNA H19 ). HDAC2 inhibited LncRNA H19 expression by histone H3K27 deacetylation in its promoter via binding with SP1. LncRNA H19 functioned as a miR-22-3P sponge to increase the expression of MMP14. HDAC2 loss strongly promoted CRC lung metastasis, which was suppressed LncRNA H19 knockdown. Conclusion: Our study supports HDAC2 as a CRC metastasis suppressor through the inhibition of EMT and the expression of H19 and MMP14.
Background: Epithelial to mesenchymal transition (EMT) is a critical step for cancer metastasis, which is regulated by epigenetic mechanisms. The role of HDACs-mediated deacytelation remains unclear in colorectal cancer (CRC) metastasis. Here, we revealed the biological role and underlying mechanism of histone deacetylase2 (HDAC2) in EMT-mediated CRC metastasis. Methods: The expression of HDACs in CRC was analyzed using the public database Oncomine and TCGA, human colorectal tumor primary sites and paired metastatic tissues, high or low metastatic CRC cell lines (DLD1, HCT116, SW480 and SW620). Microarray analysis was used to detect the gene expression changes in HDAC2 knock out CRC cells. Epithelial-mesenchymal transition (EMT)-related proteins were determined using western blot and immunofluorescence. CRC cell metastasis was assessed by transwell assay. To study the underlying mechanism of HDAC2 in EMT-mediated CRC metastasis, we performed chromatin immunoprecipitation, promoter activity, co-immunoprecipitation and RNA-binding protein immunoprecipitation assays through using CRC cells and specific siRNAs targeting H19, SP1 and MMP14. Finally, CRC metastasis in vivo was performed using a tail vain injection model. Results: Our data showed that the expression of HDAC2 was reduced in CRC metastatic tissues and and low HDAC2 expression predicted a poor clinical prognosis in CRC patients. HDAC2 deletion or knock down in CRC cells induced EMT and metastasis by upregulating the long noncoding RNA H19 (LncRNA H19). HDAC2 decreased histone H3K27 acetylation at the promoter of LncRNA H19 and its expression via a SP1-dependent mechanism. LncRNA H19 functioned as a miR-22-3P sponge to increase the expression of MMP14. Finally, using a tail vain injection model, we showed the HDAC2 loss strongly induces lung metastasis, which is suppressed by LncRNA H19 knockdown. Conclusion: Our study proved that HDAC2 is a negative regulator of EMT-mediated CRC metastasis through regulating H19 and MMP14 expression.
ObjectivesTo clarify the key role of circulating interferon-γ (IFN-γ) and to improve the clinical efficacy of mesenchymal stem cell (MSC) transplantation (MSCT) in patients with rheumatoid arthritis (RA).MethodsStudy of wild-type or IFN-γR-/- MSCT was first evaluated in a murine model of collagen-induced arthritis (CIA) following which a phase 1/2 randomised controlled study was conducted in 63 patients with RA who responded poorly to regular clinical treatments. Subjects were randomly assigned to an MSCT monotherapy group (n=32) or an MSCT plus recombinant human IFN-γ treatment group (n=31), with 1 year of follow-up. The primary end points consisted of efficacy as assessed as good or moderate EULAR response rates and the proportion of patients at 3 months attaining American College of Rheumatology 20 (ACR20) response rates.ResultsIn the murine studies, wild-type MSCT significantly improved the clinical severity of CIA, while IFN-γR-/- MSCT aggravated synovitis, and joint and cartilage damage. Transitioning from the murine to the clinical study, the 3-month follow-up results showed that the efficacy and ACR20 response rates were attained in 53.3% patients with MSCT monotherapy and in 93.3% patients with MSCT combined with IFN-γ treatment (p<0.05). No new or unexpected safety issues were encountered in 1-year follow-up for either treatment group.ConclusionsThe results of this study show that IFN-γ is a key factor in determining the efficacy of MSCT in the treatment of RA, and that an MSC plus IFN-γ combination therapeutic strategy can greatly improve the clinical efficacy of MSC-based therapy in RA patients.
Background/Aims: Nuclear factor erythroid 2-related factor 2 (Nrf2) is an oncogene in various types of cancers, including oral squamous cell carcinoma (OSCC). Oxysophocarpine (OSC) is a natural alkaloid that has multiple pharmacological activities. However, the biological functions and molecular mechanism underlying the effects of OSC on the growth and metastasis of OSCC are unclear. Methods: Nrf2 levels were determined in OSCC tissues and non-cancerous specimens by quantitative real-time PCR, western blotting, and immunohistochemistry (IHC) assays. The effects of OSC on OSCC cell growth and metastasis were explored (1) using 5-ethynyl-20-deoxyuridine staining and Cell Counting Kit-8, colony formation, flow cytometry, wound-healing, Transwell, and tube formation assays in vitro; and (2) by establishing a xenograft nude mouse model in vivo. The molecular mechanisms underlying the effects of OSC on the growth and metastasis of OSCC were investigated in vitro by western blotting, caspase-3 activity, and enzyme-linked immunosorbent assays, and in vivo by western blotting and IHC assays. Results: The expression levels of Nrf2 in OSCC tissues and in cell lines were much higher than in non-cancerous tissues and normal oral keratinocytes. The upregulation of Nrf2 was positively correlated with a high incidence of lymph node metastasis and advanced histological grade and TNM stage, but inversely associated with differentiation and survival of OSCC patients. OSC reduced the expression of Nrf2 and heme oxygenase 1 (HO-1) in OSCC cells. OSC also inhibited proliferation, migration, invasion, and pro-angiogenesis of OSCC cells. Moreover, OSC induced cell cycle arrest, enhanced apoptosis of OSCC cells in vitro, and decreased OSCC tumor growth in vivo. Mechanically, OSC reduced the aggressive behavior of OSCC cells by inactivation of the Nrf2/HO-1 signaling pathway. Conclusion: Our findings provide evidence that OSC inhibits the growth and metastasis of OSCC by targeting the Nrf2/ HO-1 axis, suggesting that OSC may be a potential therapeutic agent for OSCC.
BACKGROUND:Hemin is an important sterile component that induces a neuroinflammatory response after intracerebral hemorrhage, in which NLRP3 inflammasome activation has also proved to be involved. Although microglial activation acts as a key contributor in the neuroinflammatory response, the relationship between hemin and NLRP3 in microglia remains poorly understood. OBJECTIVE:To investigate whether or not hemin regulates microglia-mediated secondary injury through activating the NLRP3/caspase-1 signaling pathway in microglia. METHODS:In this study, N9 microglial cells were treated with hemin, and subsequently used to detect the production of caspase-1 p10 and NLRP3 inflammasome assembly. An ELISA was subsequently performed to measure the secretion of IL-1β. RESULTS:It was found that the production of activated caspase-1 was dose- and time-dependent with regards to hemin. Moreover, hemin was observed to be capable of inducing the assembly of the NLRP3 inflammasome without any increase in IL-1β. Similarly, the supernatant of hemin-treated primary microglial cells did not increase in IL-1β secretion. Furthermore, hemin-induced NLRP3 inflammasome activation did not significantly affect pyroptosis. CONCLUSION:Hemin is a potential sterile danger signal molecule that can induce inflammasome activation without directly mediating inflammation damage on microglia.
Background and Purpose- Accumulated evidence suggests that hemin-a breakdown product of hemoglobin-plays a pivotal role in the inflammatory injuries that result after hemorrhagic stroke through the Toll Like Receptor 2-Toll Like Receptor 4 signal pathway. However, the mechanism of how hemin triggers neuronal necroptosis directly after intracranial hemorrhage (ICH) is still an area of active research. As animal model and preclinical studies have shown, the recombinant interleukin-1 receptor antagonist (IL-1RA) improves clinical outcomes after stroke. As such, we have chosen to investigate the mechanism of how IL-1RA exerts protective effect in hemin-induced neuronal necroptosis after ICH. Methods- Our ICH model was induced by hemin injection in C57BL/6 mice and IL-1R1-/- mice. In addition, we used primary cultured neurons to assess hemin-induced cell death. Co-immunoprecipitation, immunoblot, immunofluorescent staining, neurological deficit scores, and brain water content were used to study the mechanisms of IL-1R1 modulation in neuronal necroptosis both in vitro and in vivo. Results- Free hemin could mediate neuronal necroptosis directly by assembling necrosome complex and then to trigger cell death. This phenomenon was driven by IL-1R1 as IL-1R1 can form a complex with necrosome. After treatment with IL-1RA, both the expression and translocation of the necrosome decreased while disruption of the interaction between IL-1R1 and RIP1/RIP3 (receptor interacting protein 1/3) increased neuron survival. In addition, the IL-1R1-deficient mice demonstrated lower levels of necrosome components, including RIP1, RIP3, and MLKL (mixed lineage kinase domain-like protein), compared with control groups after hemin treatment. In addition, the neurological deficit scores, brain water content, and inflammatory response were all also reduced in the IL-1R1-deficient mice. Conclusions- Functional inhibition of the interaction between IL-1R1 and the necrosome complex improves neuron survival and promotes the recovery of neurological function in experimental ICH. Targeting IL-1R1/RIP1/RIP3 assembly could be a promising therapeutic strategy for patients with ICH.
Background Researches showed that transforming growth factor-β2 (TGF-β2) promotes the activity of human Tenon capsular fibroblasts (TFs),which plays a role in the scarring of filtering blebs after antiglaucoma surgery.However,its mechanism is not fully clear.Lysyl oxidases (LOXs) are important extracellular matrix proteases which can catalyze the cross-linking of collagen and elastin.Investigating the impact of TGF-β2 on the expression of LOXs has a great significance for the understanding of the pathogenesis of filtering bleb scarring and its prevention.Objective This study was to investigate the effect of TGF-β2 on the expression of LOXs in cultured human TFs.Methods The TFs at 4-8 generations were divided into normal control group and different concentrations of TGF-β2 treated-groups,and 100,200,400,800 μ1 of TGF-β2 with the final concentration of 2,4,8 and 16 ng/ml was added into the medium to treat human TFs respectively for 24 hours.The LOXs in the cells were detected by Western blot to determine the optimal dose of TGF-β2.The 4 ng/ml TGF-β2(200 μ1) was used to treat human TFs for 6,12,24 and 48 hours respectively,and the change of LOXs expression in the cells over time was assayed by Western blot.The expression and distribution of LOX protein in the normal cells and TGF-β2-treated cells was detected by using immunofluorescence technique.This study was approved by Daping Hospital of Third Military Medical University Ethic Commission.The guardians of the patients who offered the specimen knew the purpose of the study and signed informed consent.Results Western blot assay showed that the expressions of LOX,LOXL1,LOXL2,LOXL3 and LOXL4 in the cells were gradually elevated from the normal control group and 2,4,8,16 ng/ml TGF-β2-treated groups,showing significant differences among the groups (F =37.338,13.438,31.067,11.767,15.167,all at P<0.01).The expression of LOXL2 protein in the cells was 0.68±0.07,1.09±0.10,1.32±0.07,1.50± 0.06 and 1.89±0.12 in the normal control group and 6-,12-,24-and 48-hour groups respectively after 4 ng/ml TGF-β2 treatment,with a significant increase over time (F =82.832,P=0.000).The expression of LOX was weak in the normal cultured TFs,while the fluorescence intensity of LOX expression was evidently enhanced in the cytoplasm of the cells in the TGF-β2-treated group.Conclusions TGF-β2 upregulates the expressions of LOXs in human TFs in a dose-and time-dependent manner,which probably offers a basis for the further study on the prevention of filtering bleb scarring after glaucoma surgery.
In this study, we explored the potential mechanisms of how PTEN regulating LPS induced TLR4 signaling pathway. The initial findings from ELISA demonstrate that PTEN influences TNF-α secretion by its lipid phosphatase activity. Subsequently, western blot, immunoprecipitation assay, and immunofluorescence were performed to explore the activation process of PTEN by stimulation with LPS. As early as 20 minutes after LPS stimulation, reduced phosphorylation of PTEN was found obviously. Accordingly, the whole cell-scattered PTEN translocated towards the cell membrane 20 minutes after stimulating with LPS. Moreover, the weak physical association between PTEN and TLR4 in resting RAW264.7 cells increased gradually after the stimulation of LPS. Furthermore, our study showed PTEN decreased LPS-induced Akt activity and upregulated NF-κB-dependent gene transcription, identifying indirectly that the PTEN could regulate the activation of NF-κB by its downstream Akt kinase. In summary, our study illustrates the potential signal transduction process of PTEN while stimulated by LPS: by increasing the association of TLR4, PTEN recruits to its phosphoinositide substrate PI(3,4,5)P3 located on the cell membrane and exerts its dephosphorylated function and subsequently depresses the activity of downstream molecule Akt and results in activation of NF-κB, followed by the secretion of inflammatory mediators TNF-α.
Objective To investigate the effect of dopamine on lipopolysaccharide (LPS)-induced inflammatory response in mouse peritoneal macrophages (MPMs).Methods MPMs were isolated after injection of thioglycolate broth into the peritoneal cavity.MPMs from wild type C57 mice were distributed into control group,LPS group,dopamine pretreatment group,dopamine D1-like and and D2-like receptor antagonist groups (D1 and D2 antagonist groups).In the latter two groups,MPMs were pretreated with Dl-like and D2-like receptor antagonist respectively for 30 min,and then stimulated with dopamine and LPS.MPMs from wild type (TLR4 +/+) and TLR4 knock-out (TLR4-/-) mice were only divided into LPS group and dopamine pretreatment group.In LPS group,MPMs were stimulated with 1 μg/ml LPS for 6 h.In dopamine pretreatment group,MPMs were pretreated with 10-4 mol/L dopamine for 2 h,and then stimulated with 1μg/ml LPS for 6 h.Expressions of TLR4 and pro-IL-1βwere detected by Western blot and tumor necrosis factor-α (TNF-α) in cell culture supernatant by ELISA method.Results (1) Expressions of TLR4,pro-IL-1β and TNF-α in control group were (0.56 ± 0.07),(0.65 ± 0.11) and (1,770.6 ±448.8) pg/ml;in LPS group were (1.12 ± 0.15),(1.24 ± 0.20) and (15,569.5 ± 822.7) pg/ml;in dopamine pretreatment group were (0.28 ± 0.11),(0.22 ± 0.08) and (7,800.7 ±862.6)pg/ml;in D1 antagonist group were (0.25 ±0.12),(0.18 ±0.09) and (7,065.0 ± 1016.8)pg/ml;in D2 antagonist group were (0.80 ±0.09),(0.44 ±0.08) and (14,299.6 ± 1430.9)pg/ml.The three indicators in LPS group were increased compared to control group and dopamine pretreatment group (P < 0.05),and in D2 antagonist group were increased compared to dopamine pretreatment group (P < 0.05).There were no obvious differences between D1 antagonist group and dopamine pretreatment group(P >0.05).(2) After LPS stimulation,expressions of pro-IL-1 β and TNF-α in TLR4+/+ mice were (0.94 ±0.17) and (15,109.0 ± 1,903.4)pg/ml,and were (0.08 ±0.04) and (5,063.6 ± 512.8) pg/ml in TLR4-/-mice (P <0.05).After dopamine pretreatment,expressions of proIL-1β and TNF-α were (0.45 ±0.12) and (6,383.9 ± 1,287.3) pg/ml in TLR4+/+ mice,and were (0.05 ± 0.02) and (4,863.0 ± 824.7) pg/ml in TLR4-/-mice.Expressions of pro-IL-1β and TNF-o were higher in TLR4 +/+ mice than in TLR4-/-mice after LPS stimulation (P < 0.05).Expressions of pro-IL-1β and TNF-αin TLR4 +/+ mice were reduced after dopamine pretreatment compared to LPS stimulation (P < 0.05),while were similar in TLR4-/-mice (P > 0.05).Conclusion Dopamine can inhibit LPS-induced inflammatory response in MPMs,and the inhibition is strongly related to dopamine D2-1ike receptor and TLR4.
Accumulating evidences have demonstrated that lipopolysaccharide (LPS) represents the important etiologic factor for sepsis. Some previous studies have reported the relationship between common polymorphisms rs4986790 and rs4986791 in the coding gene for this receptor and the susceptibility to sepsis, but there were distinct divergences between those findings. We therefore designed this meta-analysis incorporated 28 published articles containing 6,537 sepsis patients and 8,832 controls for a more comprehensive conclusion on this matter. Odds ratios (ORs) and 95% confidence interval (95% CIs) were calculated to evaluate the association of toll like receptor 4 gene polymorphisms rs4986790 and rs4986791 with sepsis risk. Heterogeneity between included studies was inspected using Q test, and sensitivity analysis was implemented via sequential deletion of each included study to investigate the stability of overall estimates. Funnel plot and Egger's test were adopted to examine publication bias across selected studies. We found no significant association for either the polymorphism rs4986790 or rs4986791 with sepsis susceptibility in total analysis under any genetic models. Neither did we after combining these two polymorphisms. The results of this meta-analysis suggest that the rs4986790 and rs4986791 polymorphisms in toll like receptor 4 gene may have no statistically significant influence on sepsis susceptibility.
PURPOSEThis study was designed to develop a chitosan (CS) thermo-sensitive gel combined with aptamer S58 targeting transforming growth factor-beta receptor II (TGF-β RII) and to investigate the antifibrotic effects of CS/S58 gel in a rat glaucoma filtration surgery (GFS) model.METHODSIn vitro aptamer S58 release rate from the CS/S58 gel were detected, and the effect of mitomycin-C (MMC), TGF-β2, CS, or CS/S58 gel on wound healing were investigated in a rat GFS model by detecting scar-related factors and the involved inflammatory response. The levels of collagen I and α-smooth muscle actin (α-SMA) were detected by immunohistochemistry and Western blotting.RESULTSThe control and TGF-β2 eyes exhibited densely packed collagen fibers with no evidence of filtration after day 7. The pronounced increase in filtration efficiency was associated with thinner fibers, and a loosely organized subconjunctival matrix was observed in CS/S58 gel-treated eyes. The levels of collagen I and α-SMA were downregulated in CS/S58 gel-treated eyes. Conjunctival fibroblast proliferation and the inflammation response were also suppressed in the CS/S58 gel-treated group.CONCLUSIONSThis study presents evidence that the antifibrotic effect of chitosan in combination with aptamer S58 is superior to chitosan alone in a rat GFS model. Chitosan/S58 gel may be considered to be a promising antifibrotic agent for a local drug therapy.