Lipopolysaccharide induces neuroinflammation in microglia by activating the MTOR pathway and downregulating Vps34 to inhibit autophagosome formation

Abstract Background Microglial activation is a prominent feature of neuroinflammation, which is present in almost all neurodegenerative diseases. While an initial inflammatory response mediated by microglia is considered to be protective, excessive pro-inflammatory response of microglia contributes to the pathogenesis of neurodegeneration. Although autophagy is involved in the suppression of inflammation, its role and mechanism in microglia are unclear. Methods In the present study, we studied the mechanism by which lipopolysaccharide (LPS) affects microglial autophagy and the effects of autophagy on the production of pro-inflammatory factors in microglial cells by western blotting, immunocytochemistry, transfection, transmission electron microscopy (TEM), and real-time PCR. In a mouse model of neuroinflammation, generated by intraventricular injection of LPS (5 μg/animal), we induced autophagy by rapamycin injection and investigated the effects of enhanced autophagy on microglial activation by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry. Results We found that autophagic flux was suppressed in LPS-stimulated N9 microglial cells, as evidenced by decreased expression of the autophagy marker LC3-II (lipidated form of MAP1LC3), as well as increased levels of the autophagy adaptor protein SQSTM1. LPS significantly decreased Vps34 expression in N9 microglial cells by activating the PI3KI/AKT/MTOR pathway without affecting the levels of lysosome-associated proteins and enzymes. More importantly, overexpression of Vps34 significantly enhanced the autophagic flux and decreased the accumulation of SQSTM1 in LPS-stimulated N9 microglial cells. Moreover, our results revealed that an LPS-induced reduction in the level of Vps34 prevented the maturation of omegasomes to phagophores. Furthermore, LPS-induced neuroinflammation was significantly ameliorated by treatment with the autophagy inducer rapamycin both in vitro and in vivo. Conclusions These data reveal that LPS-induced neuroinflammation in N9 microglial cells is associated with the inhibition of autophagic flux through the activation of the PI3KI/AKT/MTOR pathway, while enhanced microglial autophagy downregulates LPS-induced neuroinflammation. Thus, this study suggests that promoting the early stages of autophagy might be a potential therapeutic approach for neuroinflammation-associated diseases.

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NOD1/RIP2 signalling enhances the microglia-driven inflammatory response and undergoes crosstalk with inflammatory cytokines to exacerbate brain damage following intracerebral haemorrhage in mice

Journal of Neuroinflammation ◽

10.1186/s12974-020-02015-9 ◽

2020 ◽

Vol 17 (1) ◽

Author(s):

Miao Wang ◽

Xinchun Ye ◽

Jinxia Hu ◽

Qiuchen Zhao ◽

Bingchen Lv ◽

...

Keyword(s):

Inflammatory Response ◽

Brain Damage ◽

Microglial Activation ◽

Inflammatory Factors ◽

Primary Microglia ◽

Tnf Α ◽

Factor Α ◽

Necrosis Factor

Abstract Background Secondary brain damage caused by the innate immune response and subsequent proinflammatory factor production is a major factor contributing to the high mortality of intracerebral haemorrhage (ICH). Nucleotide-binding oligomerization domain 1 (NOD1)/receptor-interacting protein 2 (RIP2) signalling has been reported to participate in the innate immune response and inflammatory response. Therefore, we investigated the role of NOD1/RIP2 signalling in mice with collagenase-induced ICH and in cultured primary microglia challenged with hemin. Methods Adult male C57BL/6 mice were subjected to collagenase for induction of ICH model in vivo. Cultured primary microglia and BV2 microglial cells (microglial cell line) challenged with hemin aimed to simulate the ICH model in vitro. We first defined the expression of NOD1 and RIP2 in vivo and in vitro using an ICH model by western blotting. The effect of NOD1/RIP2 signalling on ICH-induced brain injury volume, neurological deficits, brain oedema, and microglial activation were assessed following intraventricular injection of either ML130 (a NOD1 inhibitor) or GSK583 (a RIP2 inhibitor). In addition, levels of JNK/P38 MAPK, IκBα, and inflammatory factors, including tumour necrosis factor-α (TNF-α), interleukin (IL)-1β, and inducible nitric oxide synthase (iNOS) expression, were analysed in ICH-challenged brain and hemin-exposed cultured primary microglia by western blotting. Finally, we investigated whether the inflammatory factors could undergo crosstalk with NOD1 and RIP2. Results The levels of NOD1 and its adaptor RIP2 were significantly elevated in the brains of mice in response to ICH and in cultured primary microglia, BV2 cells challenged with hemin. Administration of either a NOD1 or RIP2 inhibitor in mice with ICH prevented microglial activation and neuroinflammation, followed by alleviation of ICH-induced brain damage. Interestingly, the inflammatory factors interleukin (IL)-1β and tumour necrosis factor-α (TNF-α), which were enhanced by NOD1/RIP2 signalling, were found to contribute to the NOD1 and RIP2 upregulation in our study. Conclusion NOD1/RIP2 signalling played an important role in the regulation of the inflammatory response during ICH. In addition, a vicious feedback cycle was observed between NOD1/RIP2 and IL-1β/TNF-α, which could to some extent result in sustained brain damage during ICH. Hence, our study highlights NOD1/RIP2 signalling as a potential therapeutic target to protect the brain against secondary brain damage during ICH.

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Long non-coding RNA OIP5-AS1 aggravates acute lung injury by promoting inflammation and cell apoptosis via regulating the miR-26a-5p/TLR4 axis

BMC Pulmonary Medicine ◽

10.1186/s12890-021-01589-1 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Qingsong Sun ◽

Man Luo ◽

Zhiwei Gao ◽

Xiang Han ◽

Weiqin Wu ◽

...

Keyword(s):

Acute Lung Injury ◽

Lung Injury ◽

Inflammatory Response ◽

Cell Apoptosis ◽

Quantitative Polymerase Chain Reaction ◽

Luciferase Reporter ◽

Enzyme Linked Immunosorbent Assay ◽

Interacting Protein ◽

Wide Range

Abstract Background Acute lung injury (ALI) is a pulmonary disorder that leads to acute respiration failure and thereby results in a high mortality worldwide. Increasing studies have indicated that toll-like receptor 4 (TLR4) is a promoter in ALI, and we aimed to explore the underlying upstream mechanism of TLR4 in ALI. Methods We used lipopolysaccharide (LPS) to induce an acute inflammatory response in vitro model and a murine mouse model. A wide range of experiments including reverse transcription quantitative polymerase chain reaction, western blot, enzyme linked immunosorbent assay, flow cytometry, hematoxylin–eosin staining, RNA immunoprecipitation, luciferase activity and caspase-3 activity detection assays were conducted to figure out the expression status, specific role and potential upstream mechanism of TLR4 in ALI. Result TLR4 expression was upregulated in ALI mice and LPS-treated primary bronchial/tracheal epithelial cells. Moreover, miR-26a-5p was confirmed to target TLR4 according to results of luciferase reporter assay. In addition, miR-26a-5p overexpression decreased the contents of proinflammatory factors and inhibited cell apoptosis, while upregulation of TLR4 reversed these effects of miR-26a-5p mimics, implying that miR-26a-5p alleviated ALI by regulating TLR4. Afterwards, OPA interacting protein 5 antisense RNA 1 (OIP5-AS1) was identified to bind with miR-26a-5p. Functionally, OIP5-AS1 upregulation promoted the inflammation and miR-26a-5p overexpression counteracted the influence of OIP5-AS1 upregulation on cell inflammatory response and apoptosis. Conclusion OIP5-AS1 promotes ALI by regulating the miR-26a-5p/TLR4 axis in ALI mice and LPS-treated cells, which indicates a promising insight into diagnostics and therapeutics in ALI.

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Up-regulation of long non-coding RNA CYTOR induced by icariin promotes the viability and inhibits the apoptosis of chondrocytes

BMC Complementary Medicine and Therapies ◽

10.1186/s12906-021-03322-1 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Guoyou Wang ◽

Lei Zhang ◽

Huarui Shen ◽

Qi Hao ◽

Shijie Fu ◽

...

Keyword(s):

Inflammatory Response ◽

Inflammatory Factors ◽

Enzyme Linked Immunosorbent Assay ◽

Protective Effects ◽

Loss Of Function ◽

Protective Function ◽

Non Coding Rna ◽

Effective Component ◽

Short Hairpin Rnas ◽

Function Models

Abstract Background Icariin (ICAR) is the main effective component extracted from epimedium, and is reported to have the potential to treat osteoarthritis (OA). However, its pharmacological function on chondrocytes has not been fully clarified. Methods Different doses of ICAR were used to treat chondrocyte cell lines, including CHON-001 and ATDC5. Then the expressions of different lncRNAs were measured by qRT-PCR. Interleukin-1β (IL-1β) was used to simulate the inflammatory response environment of chondrocytes. Overexpression plasmids and short hairpin RNAs of lncRNA CYTOR were used to construct gain-of-function and loss of function models. CCK-8 was conducted to determine the cell viability. Flow cytometry was used to detect the apoptosis of chondrocytes. Enzyme-linked immunosorbent assay (ELISA) was adopted to measure the contents of inflammatory factors (IL-6, IL-8, TNF-α) in the supernatant of the chondrocytes. Results Compared with other lncRNAs, CYTOR was changed most significantly in both CHON-001 and ATDC5 cells after treatment with ICAR. ICAR promotes the viability and inhibits the apoptosis of CHON-001 and ATDC5 cells induced by IL-1β, accompanied with reduced levels of inflammatory factors. Overexpression of CYTOR facilitated the viability of chondrocytes, while repressed their apoptosis and inflammatory response. What’s more, knockdown of CYTOR reversed the protective effects of ICAR on chondrocytes. Conclusion CYTOR was a pivotal lncRNA involved in the protective function of ICAR on chondrocytes.

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Astrocyte-Derived CCL2 is Associated with M1 Activation and Recruitment of Cultured Microglial Cells

Cellular Physiology and Biochemistry ◽

10.1159/000443040 ◽

2016 ◽

Vol 38 (3) ◽

pp. 859-870 ◽

Cited By ~ 27

Author(s):

Mingfeng He ◽

Hongquan Dong ◽

Yahui Huang ◽

Shunmei Lu ◽

Shu Zhang ◽

...

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Microglial Activation ◽

Culture Media ◽

Microglial Cells ◽

Migration Ability ◽

Migration Assay ◽

Tnf Α

Background/Aims: Microglia are an essential player in central nervous system inflammation. Recent studies have demonstrated that the astrocytic chemokine, CCL2, is associated with microglial activation in vivo. However, CCL2-induced microglial activation has not yet been studied in vitro. The purpose of the current study was to understand the role of astrocyte-derived CCL2 in microglial activation and to elucidate the underlying mechanism(s). Methods: Primary astrocytes were pre-treated with CCL2 siRNA and stimulated with TNF-α. The culture medium (CM) was collected and added to cultures of microglia, which were incubated with and without CCR2 inhibitor. Microglial cells were analyzed by quantitative RT-PCR to determine whether they polarized to the M1 or M2 state. Microglial migratory ability was assessed by transwell migration assay. Results: TNF-α stimulated the release of CCL2 from astrocytes, even if the culture media containing TNF-α was replaced with fresh media after 3 h. CM from TNF-α-stimulated astrocytes successfully induced microglial activation, which was ascertained by increased activation of M1 and enhanced migration ability. In contrast, CM from astrocytes pretreated with CCL2 siRNA showed no effect on microglial activation, compared to controls. Additionally, microglia pre-treated with RS102895, a CCR2 inhibitor, were resistant to activation by CM from TNF-α-stimulated astrocytes. Conclusion: This study demonstrates that the CCL2/CCR2 pathway of astrocyte-induced microglial activation is associated with M1 polarization and enhanced migration ability, indicating that this pathway could be a useful target to ameliorate inflammation in the central nervous system.

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Daphnetin inhibits proliferation and inflammatory response in human HaCaT keratinocytes and ameliorates imiquimod-induced psoriasis-like skin lesion in mice

Biological Research ◽

10.1186/s40659-020-00316-0 ◽

2020 ◽

Vol 53 (1) ◽

Author(s):

Jintao Gao ◽

Fangru Chen ◽

Huanan Fang ◽

Jing Mi ◽

Qi Qi ◽

...

Keyword(s):

Skin Lesion ◽

Inflammatory Response ◽

Mouse Model ◽

Nuclear Translocation ◽

Marker Gene ◽

Inflammatory Factors ◽

Mrna Levels ◽

Hacat Keratinocytes ◽

Tnf Α

Abstract Background Psoriasis is a common chronic inflammatory skin disease. Keratinocytes hyperproliferation and excessive inflammatory response contribute to psoriasis pathogenesis. The agents able to attenuate keratinocytes hyperproliferation and excessive inflammatory response are considered to be potentially useful for psoriasis treatment. Daphnetin exhibits broad bioactivities including anti-proliferation and anti-inflammatory. This study aims to evaluate the anti-psoriatic potential of daphnetin in vitro and in vivo, and explore underlying mechanisms. Methods HaCaT keratinocytes was stimulated with the mixture of IL-17A, IL-22, oncostatin M, IL-1α, and TNF-α (M5) to establish psoriatic keratinocyte model in vitro. Cell viability was measured using Cell Counting Kit-8 (CCK-8). Quantitative Real-Time PCR (qRT-PCR) was performed to measure the mRNA levels of hyperproliferative marker gene keratin 6 (KRT6), differentiation marker gene keratin 1 (KRT1) and inflammatory factors IL-1β, IL-6, IL-8, TNF-α, IL-23A and MCP-1. Western blotting was used to detect the protein levels of p65 and p-p65. Indirect immunofluorescence assay (IFA) was carried out to detect p65 nuclear translocation. Imiquimod (IMQ) was used to construct psoriasis-like mouse model. Psoriasis severity (erythema, scaling) was scored based on Psoriasis Area Severity Index (PASI). Hematoxylin and eosin (H&E) staining was performed to examine histological change in skin lesion. The expression of inflammatory factors including IL-6, TNF-α, IL-23A and IL-17A in skin lesion was measured by qRT-PCR. Results Daphnetin attenuated M5-induced hyperproliferation in HaCaT keratinocytes. M5 stimulation significantly upregulated mRNA levels of IL-1β, IL-6, IL-8, TNF-α, IL-23A and MCP-1. However, daphnetin treatment partially attenuated the upregulation of those inflammatory cytokines. Daphnetin was found to be able to inhibit p65 phosphorylation and nuclear translocation in HaCaT keratinocytes. In addition, daphnetin significantly ameliorate the severity of skin lesion (erythema, scaling and epidermal thickness, inflammatory cell infiltration) in IMQ-induced psoriasis-like mouse model. Daphnetin treatment attenuated IMQ-induced upregulation of inflammatory cytokines including IL-6, IL-23A and IL-17A in skin lesion of mice. Conclusions Daphnetin was able to attenuate proliferation and inflammatory response induced by M5 in HaCaT keratinocytes through suppression of NF-κB signaling pathway. Daphnetin could ameliorate the severity of skin lesion and improve inflammation status in IMQ-induced psoriasis-like mouse model. Daphnetin could be an attractive candidate for future development as an anti-psoriatic agent.

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Modulation of the Lung Inflammatory Response to Serotype 8 Pneumococcal Infection by a Human Immunoglobulin M Monoclonal Antibody to Serotype 8 Capsular Polysaccharide

Infection and Immunity ◽

10.1128/iai.73.8.4530-4538.2005 ◽

2005 ◽

Vol 73 (8) ◽

pp. 4530-4538 ◽

Cited By ~ 26

Author(s):

Tamika Burns ◽

Maria Abadi ◽

Liise-anne Pirofski

Keyword(s):

Monoclonal Antibody ◽

Inflammatory Response ◽

Capsular Polysaccharide ◽

Human Monoclonal Antibody ◽

Pneumococcal Infection ◽

Immunoglobulin M ◽

Enzyme Linked Immunosorbent Assay ◽

Necrosis Factor Alpha ◽

Monocyte Chemoattractant Protein 1

ABSTRACT The human monoclonal antibody to serotype 8 pneumococcal capsular polysaccharide D11 [immunoglobulin M(κ)] protects wild-type and complement component 4 knockout (C4 KO) mice against lethal intratracheal challenge with serotype 8 pneumococcus, but it does not promote polymorphonuclear leukocyte (PMN)-mediated pneumococcal killing in vitro. In this study, we investigated the effect of D11 on the blood and lung bacterial burdens and the serum and lung expression of inflammatory chemokines and cytokines in an intratracheal challenge model with serotype 8 pneumococcus in C4 KO mice. Pneumococcus was not detected in the blood of D11-treated mice, whereas control mice had high-grade bacteremia with >107 CFU. Control mice had a >5-log increase in lung CFU and D11-treated mice manifested a nearly 3-log increase in lung CFU compared to the original inoculum 24 h after infection. Serum and lung levels of soluble macrophage inflammatory protein 2 (MIP-2) and interleulin-6 (IL-6) as measured by an enzyme-linked immunosorbent assay were lower in D11-treated mice than in control mice 24 h after infection. Real-time PCR was performed to examine lung mRNA chemokine and cytokine expression. The results showed that D11-treated mice had significantly less gamma interferon, MIP-2, IL-12, monocyte chemoattractant protein 1/JE, and tumor necrosis factor alpha expression than control mice 24 h after infection. Histopathology and immunohistochemical staining of lung tissues revealed that D11-treated mice had less inflammation, fewer PMNs, and less myeloperoxidase staining than control mice 24 h after infection. These findings suggest that the efficacy of certain serotype-specific antibodies against pneumococcal pneumonia could be associated with modulation of the lung inflammatory response and a reduction in host damage.

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RhTrx-1 ameliorates miroglial neuroinflammation after cerebral ischemic stroke

10.21203/rs.3.rs-18172/v1 ◽

2020 ◽

Author(s):

Yang Jiao ◽

Jianjian Wang ◽

Huixue Zhang ◽

Yuze Cao ◽

Yang Qu ◽

...

Keyword(s):

Ischemic Stroke ◽

Inflammatory Response ◽

Inflammatory Responses ◽

Inflammatory Factors ◽

Experimental Stroke ◽

Inflammasome Activation ◽

Cerebral Ischemic

Abstract Background Microglia are rapidly activated after ischemic stroke and participate in the occurrence of neuroinflammation, which exacerbates the injury of ischemic stroke. Receptor Interacting Serine Threonine Kinase 1 (RIPK1) is thought to be involved in the development of inflammatory responses, but its role in ischemic microglia remains unclear. Here, we applied recombinant human thioredoxin-1 (rhTrx-1), a potential neuroprotective agent, to explore the role of rhTrx-1 in inhibiting RIPK1-mediated neuroinflammatory responses in microglia. Method Middle cerebral artery occlusion (MCAO) and Oxygen and glucose deprivation (OGD) were conducted for in vivo and in vitro experimental stroke models. The expression of RIPK1 in microglia after ischemia was examined. The inflammatory response of microglia was analyzed after treatment with rhTrx-1 and Necrostatin-1 (Nec-1, inhibitors of RIPK1), and the mechanisms were explored. In addition, the effects of rhTrx-1 on neurobehavioral deficits and cerebral infarct volume were examined. Results RIPK1 expression was detected in microglia after ischemia. Molecular docking results showed that rhTrx-1 could directly bind to RIPK1. In vitro experiments found that rhTrx-1 reduced necroptosis, mitochondrial membrane potential damage, Reactive oxygen species (ROS) accumulation and NLR Family, pyrin domain-containing 3 protein (NLRP3) inflammasome activation by inhibiting RIPK-1 expression, and regulated microglial M1/M2 phenotypic changes, thereby reducing the release of inflammatory factors. Consistently, in vivo experiments found that rhTrx-1 treatment attenuated cerebral ischemic injury by inhibiting the inflammatory response. Conclusion Our study demonstrates the role of RIPK1 in microglia-arranged neuroinflammation after cerebral ischemia. Administration of rhTrx-1 provides neuroprotection in ischemic stroke-induced microglial neuroinflammation by inhibiting RIPK1 expression.

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Hydrogen Sulfide Ameliorates High Glucose-induced Inflammation Through SIRT1-mTOR/NF-κB Signaling Pathway in HT-22 cells

10.21203/rs.3.rs-48940/v1 ◽

2020 ◽

Author(s):

Xinrui Li ◽

Yinghua Yu ◽

Peiquan Yu ◽

Ting Xu ◽

Jiao Liu ◽

...

Keyword(s):

Hydrogen Sulfide ◽

Inflammatory Response ◽

Signaling Pathway ◽

High Glucose ◽

Near Infrared ◽

Neuronal Cell ◽

Inflammatory Factors ◽

Sodium Hydrosulfide ◽

Protein Levels

Abstract Background: Hyperglycemia-induced neuroinflammation promotes the progression of diabetic encephalopathy (DE). Hydrogen sulfide (H2S) exerts anti-inflammatory and neuroprotective activities against neurodegenerative diseases. However, its role in hyperglycemia-induced neuronal inflammation has not been investigated. Herein, we examined the effects and its related signaling pathway of H2S on inflammatory response in high glucose-treated HT-22 cells.Methods: A hippocampal neuronal cell line, HT-22, was used as an in vitro model to explore the function of H2S on inflammatory response triggered by high glucose. A dicyanoisophorone-based near-infrared fluorescent probe (NIR-NP) was synthesized to detect H2S levels in HT-22 cells. Western blotting, immunofluorescence and real time-qPCR were carried out to study the mechanism of action for H2S.Results: We found that high glucose (85 mM) decreased the level of endogenous H2S and the expression of cystathionine-β-synthase (CBS) which is the main enzyme for H2S production in the brain. Sodium hydrosulfide (NaHS, a H2S donor) or S-adenosylmethionine (SAMe, an allosteric activator of CBS) administration restored high glucose-induced downregulation of CBS and H2S levels. Importantly, high glucose upregulated the level of pro-inflammatory factors (IL-1β, IL-6, TNF-α) in HT-22 cells. Treatment with NaHS or SAMe alleviated this enhanced transcription of these pro-inflammatory factors, suggesting that H2S might ameliorate high glucose-induced inflammation in HT-22 cells. We also found that high glucose reduced SIRT1 protein levels. SIRT1 reduction elevated the level of p-mTOR, p-NF-κB and pro-inflammatory factors, which were restored by resveratrol (a SIRT1 agonist). These results suggested that SIRT1 might be an upstream mediator of mTOR/NF-κB signaling pathway. Furthermore, NaHS or SAMe treatment reversed the expression of SIRT1, mTOR and NF-κB under high glucose conditions.Conclusions: Our study revealed that high glucose decreased CBS to reduce the production of H2S, which in turn decreased the expression of SIRT1. The reduction of SIRT1 activated mTOR/NF-κB signaling to promote inflammation. Given that promoting H2S production using NaHS or SAMe can reverse high glucose-induced inflammatory response, our study might shed light on the prophylactic treatment of DE.

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Paeoniflorin Attenuates Inflammatory Pain by Inhibiting Microglial Activation and Akt-NF-κB Signaling in the Central Nervous System

Cellular Physiology and Biochemistry ◽

10.1159/000490076 ◽

2018 ◽

Vol 47 (2) ◽

pp. 842-850 ◽

Cited By ~ 14

Author(s):

Bo Hu ◽

Guangtao Xu ◽

Xiaomin Zhang ◽

Long Xu ◽

Hong Zhou ◽

...

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Signaling Pathway ◽

Inflammatory Pain ◽

Microglial Activation ◽

Enzyme Linked Immunosorbent Assay ◽

Pain Model ◽

The Central Nervous System

Background/Aims: Paeoniflorin (PF) is known to have anti-inflammatory and paregoric effects, but the mechanism underlying its analgesic effect remains unclear. The aim of this study was to clarify the effect of PF on Freund’s complete adjuvant (CFA)-induced inflammatory pain and explore the underlying molecular mechanism. Methods: An inflammatory pain model was established by intraplantar injection of CFA in C57BL/6J mice. After intrathecal injection of PF daily for 8 consecutive days, thermal and mechanical withdrawal thresholds, the levels of inflammatory factors TNF-α, IL-1β and IL-6, microglial activity, and the expression of Akt-NF-κB signaling pathway in the spinal cord tissue were detected by animal ethological test, cell culture, enzyme-linked immunosorbent assay, immunofluorescence histochemistry, and western blot. Results: PF inhibited the spinal microglial activation in the CFA-induced pain model. The production of proinflammatory cytokines was decreased in the central nervous system after PF treatment both in vivo and in vitro. PF further displayed a remarkable effect on inhibiting the activation of Akt-NF-κB signaling pathway in vivo and in vitro. Conclusion: These results suggest that PF is a potential therapeutic agent for inflammatory pain and merits further investigation.

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Ulinastatin improves renal microcirculation by protecting endothelial cells and inhibiting autophagy in a septic rat model

Kidney & Blood Pressure Research ◽

10.1159/000521648 ◽

2022 ◽

Author(s):

Tian Li ◽

Xiaojun Ji ◽

Jingfeng Liu ◽

Xinjie Guo ◽

Ran Pang ◽

...

Keyword(s):

Inflammatory Response ◽

Rat Model ◽

Cecal Ligation ◽

Kidney Tissue ◽

Kidney Injury ◽

Inflammatory Factors ◽

Enzyme Linked Immunosorbent Assay ◽

Sprague Dawley ◽

Male Adult ◽

Renal Microcirculation

Introduction: Increased permeability of the renal capillaries is a common consequence of sepsis-associated acute kidney injury. Vascular endothelial (VE)-cadherin is a strictly endothelial-specific adhesion molecule that can control the permeability of the blood vessel wall. Additionally, autophagy plays an important role in maintaining cell stability. Ulinastatin, a urinary trypsin inhibitor, attenuates the systemic inflammatory response and visceral vasopermeability. However, it is uncertain whether ulinastatin can improve renal microcirculation by acting on the endothelial adhesion junction. Methods: We observed the effect of ulinastatin in a septic rat model using contrast-enhanced ultrasonography (CEUS) to evaluate the perfusion of the renal cortex and medulla. Male adult Sprague-Dawley rats were subjected to cecal ligation and puncture and divided into the sham, sepsis, and ulinastatin groups. Ulinastatin (50,000 U/kg) was injected into the tail vein immediately after the operation. The CEUS was performed to evaluate the renal microcirculation perfusion at 3, 6, 12, and 24 hours after the operation. Histological staining was used to evaluate kidney injury scores. Western blot (WB) was used to quantify the expression of VE-cadherin, LC3II, and inflammatory factors [interleukin -1β (IL-1β), interleukin -6 (IL-6), and tumor necrosis factor-α (TNF-α)] in kidney tissue, and enzyme-linked immunosorbent assay (ELISA) detected serum inflammatory factors and kidney function and early kidney injury biomarker levels. Results: Compared with the sham group, ulinastatin reduced the inflammatory response, inhibited autophagy, maintained the expression of VE-cadherin, and meliorated cortical and medullary perfusion. Conclusion: Ulinastatin effectively protects the adhesion junction and helps ameliorate the perfusion of kidney capillaries during sepsis by the inhibition of autophagy and the expression of inflammatory factors.

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